Magnetic lifting device having a pole shoe with spaced projections

Abstract

To provide a switchable magnetic device including a pole shoe that generates a shallow magnetic field in a ferromagnetic workpiece and has sufficient coercive force.SOLUTION: The magnetic device 10 comprises a housing 28 having a central bore. Each of the plurality of pole sectors arranged within the envelope of the central bore and forming a workpiece contact interface 17 ', 17 " of the magnetic device comprises a plurality of spaced apart pole portions 18, 20, 22, 24 arranged at respective distances, wherein a recess of the plurality of recesses separates each pole portion of the plurality of pole portions, and wherein the first sector forms a first pole of the magnetic device with the first permanent magnet 14; A second sector forms a second pole of the magnetic device with a second permanent magnet 12 that is movable relative to the first permanent magnet. An actuator 32 is then operatively coupled to the second permanent magnet to move the second permanent magnet relative to the first permanent magnet.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to magnetic devices, and more particularly, to pole shoes for switchable magnetic devices. [Background technology]

[0002] Switchable magnetic devices can be used to magnetically couple a magnetic device to one or more ferromagnetic bodies. The switchable magnetic device can include one or more magnet(s) that are rotatable relative to one or more fixed magnet(s) to generate and shunt magnetic fields. By switching the magnet device between an "on" state and an "off" state, the switchable magnetic device can be removably attached to a ferromagnetic body (e.g., a workpiece) for lifting objects, handling materials, holding materials, magnetically latching or coupling objects to one another, among other uses. Summary of the Invention [Means for solving the problem]

[0003]

[0003] Embodiments of the present disclosure relate to a pole shoe for a switchable magnetic device. In embodiments, the pole shoe includes a plurality of protrusions that facilitate generating a shallow magnetic field on a ferromagnetic workpiece being moved by the magnetic device, the shallow magnetic field having sufficient holding force to lift the coupled ferromagnetic workpiece and hold the ferromagnetic workpiece against shear forces during transport. Accordingly, a switchable magnetic device including a pole shoe can be used to destack thin materials. Exemplary embodiments include the following:

[0004] In an exemplary embodiment of the present disclosure, a magnetic device for magnetically coupling to a ferromagnetic body includes a housing having a central bore; a plurality of pole sectors disposed within an envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced apart pole portions disposed at respective distances, a recess of the plurality of recesses separating each pole portion of the plurality of pole portions, a first sector of the plurality of sectors forming a first pole of the magnetic device, and a second sector of the plurality of sectors forming a second pole of the magnetic device; at least one first permanent magnet supported by the housing and having an active N-S pole pair; and at least one second permanent magnet supported by the housing and having an active N-S pole pair. the magnetic device comprises at least one second permanent magnet, the second permanent magnet being movable relative to the first permanent magnet; and an actuator operatively coupled to the at least one second permanent magnet to move the at least one second permanent magnet relative to the at least one first permanent magnet, the magnetic device establishing a first magnetic circuit with the at least one first permanent magnet and the at least one second permanent magnet through the plurality of pole sectors when the at least one second permanent magnet is positioned at a first position relative to the at least one first permanent magnet by the actuator, and establishing a second magnetic circuit with the first permanent magnet and the second permanent magnet when the second permanent magnet is positioned at a second position relative to the at least one first permanent magnet by the actuator.

[0005] In that embodiment, the at least one first permanent magnet comprises a first platter supported by the housing, the first platter comprising a first plurality of spaced apart permanent magnet portions, each having a north pole side and a south pole side, and a first plurality of pole portions interposed between adjacent permanent magnet portions of the first plurality of permanent magnet portions, the first platter comprising an equal number of permanent magnet portions and pole portions, the first plurality of permanent magnets being such that each pole portion of the first plurality of pole portions has a first the at least one second permanent magnet is arranged to be one of an N-pole portion adjacent to the N-pole sides of two permanent magnet portions of the plurality of permanent magnet portions and an S-pole portion adjacent to the S-pole sides of two permanent magnet portions of the first plurality of permanent magnet portions, the at least one second permanent magnet comprises a second platter supported by the housing, the second platter comprising a second plurality of spaced apart permanent magnet portions each having an N-pole side and an S-pole side, and a second plurality of pole portions interposed between adjacent permanent magnet portions of the second plurality of permanent magnet portions, the second platter comprising an equal number of permanent magnet portions and pole portions, the second plurality of permanent magnets being arranged such that each pole portion of the first plurality of pole portions is one of an N-pole portion adjacent to the N-pole sides of two permanent magnet portions of the second plurality of permanent magnet portions and an S-pole portion adjacent to the S-pole sides of two permanent magnet portions of the second plurality of permanent magnet portions, the second platter including a rotational engagement portion.

[0006] In another embodiment thereof, the actuator rotates at least one second permanent magnet relative to the at least one first permanent magnet.

[0007] In yet another embodiment thereof, the actuator is one of a rotary actuator and a linear actuator.

[0008] In yet another embodiment thereof, the actuator linearly translates at least one second permanent magnet relative to the at least one first permanent magnet.

[0009] In yet another embodiment thereof, the at least one second permanent magnet is housed in a second housing received in the housing, and the second housing is rotatable by the actuator to rotate the at least one second permanent magnet.

[0010] In another exemplary embodiment of the present disclosure, a magnetic device for magnetically coupling to a ferromagnetic body includes a housing having a central bore; a plurality of pole sectors disposed within an envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced apart pole portions disposed at respective distances, a recess of the plurality of recesses separating each pole portion of the plurality of pole portions, a first sector of the plurality of sectors forming a first pole of the magnetic device, and a second sector of the plurality of sectors forming a second pole of the magnetic device; and an active element supported by the housing. at least one first permanent magnet having a positive north-south pole pair; and an actuator operatively coupled to the at least one first permanent magnet to move the at least one first permanent magnet relative to a base of a housing, the magnetic device establishing a first magnetic circuit through the plurality of pole sectors when the at least one first permanent magnet is positioned by the actuator at a first position relative to the base of the housing, and establishing a second magnetic circuit substantially within the housing when the at least one first permanent magnet is positioned by the actuator at a second position relative to the base of the housing.

[0011] In that embodiment, a first magnetic circuit passes through the first sector and the second sector to couple the ferromagnetic material to the magnetic device, and a second magnetic circuit remains substantially within at least a portion of the housing.

[0012] In another embodiment thereof, each recess of the plurality of recesses is sized to prevent ferromagnetic material from entering the respective recess.

[0013] In yet another embodiment thereof, each of the plurality of recesses has a respective contour extending between adjacent poles, each contour having a continuous slope.

[0014] In yet another embodiment thereof, at least one of the plurality of recesses has a depth substantially equal to a thickness of a ferromagnetic material coupled to the magnetic device.

[0015] In yet another embodiment thereof, each of the recesses has a depth substantially equal to the thickness of the ferromagnetic material that is coupled to the magnetic device.

[0016] In yet another embodiment thereof, at least one of the recesses has a width substantially equal to a thickness of a ferromagnetic material coupled to the magnetic device.

[0017] In yet another embodiment thereof, each of the recesses has a width substantially equal to a thickness of a ferromagnetic material that is coupled to the magnetic device.

[0018] In yet another embodiment thereof, at least one of the recesses has a width substantially equal to a depth of the at least one recess.

[0019] In yet another embodiment thereof, each of the plurality of pole sectors is a single pole sector. In yet another embodiment thereof, each of the plurality of pole sectors extends below the housing such that the housing is spaced apart from the ferromagnetic body when the workpiece contact interfaces of the first and second sectors contact the ferromagnetic body.

[0020] In yet another embodiment thereof, the device further comprises a compressible member disposed between each of the plurality of poles.

[0021] In yet another embodiment thereof, the workpiece contact interface forms a non-linear workpiece contact interface.

[0022] In yet another embodiment thereof, the workpiece contact interface forms a linear workpiece contact interface.

[0023] In yet another embodiment thereof, the actuator is one of a hydraulic actuator, a pneumatic actuator, and an electric actuator.

[0024] In yet another embodiment thereof, each of the plurality of pole sectors carries a compressible component positioned to contact the ferromagnetic body when the ferromagnetic body is coupled to the magnetic device.

[0025] In yet another embodiment thereof, the magnetic coupling device is carried by at least one selected from the group of a mechanical gantry, a crane hoist, a fixture, and a robotic fixture.

[0026] In another exemplary embodiment of the present disclosure, a method of attaching a magnetic device to a ferromagnetic body, the magnetic device configured to establish a first magnetic circuit and a second magnetic circuit, the magnetic device comprising a housing having a central bore, at least one first permanent magnet supported by the housing and having an active North-South pole pair, at least one second permanent magnet supported by the housing and having an active North-South pole pair, the at least one second permanent magnet being movable relative to the first permanent magnet, a plurality of pole sectors disposed within an envelope of the central bore and forming a workpiece contact interface of the magnetic device, the first sector including a plurality of spaced apart pole portions disposed at respective distances that collectively form the contact interface of the first sector; and a step of contacting the ferromagnetic body with a second sector of the plurality of sectors. the second sector including a plurality of spaced apart pole portions collectively forming a contact interface of the second sector; transitioning the magnetic device from an off state to an on state.

[0027] In that embodiment, a first magnetic circuit passes substantially through the first sector and the second sector to couple the ferromagnetic material to the magnetic device, and a second magnetic circuit remains substantially within at least a portion of the housing.

[0028] In another exemplary embodiment of the present disclosure, a magnetic coupling device for magnetically coupling to a ferromagnetic workpiece comprises: a housing having a vertical axis extending between an upper portion of the housing and a lower portion of the housing; one or more ferromagnetic pieces disposed at or near the upper portion of the housing; a pole plate support by the housing, the pole plate comprising a plurality of protrusions collectively forming a workpiece contact interface for the ferromagnetic workpiece; and a magnetic platter supported by the housing, the magnetic platter comprising a plurality of permanent magnet portions and a plurality of pole portions, wherein a pole portion of the plurality of pole portions is adjacent to a north pole side of at least one permanent magnet portion of the one or more permanent magnet portions and a north pole side of at least one permanent magnet portion of the one or more permanent magnet portions. Each permanent magnet portion of the one or more permanent magnet portions is positioned adjacent to two pole portions of the plurality of pole portions so that one of the south pole portions is adjacent to the south pole side; the magnetic platter is linearly translatable within the housing along a vertical axis for at least each of a first state and a second state; the magnetic platter is positioned adjacent to the one or more ferromagnetic pieces so that, when the magnetic platter is in the first state, the magnetic coupling device establishes a first magnetic circuit through the one or more ferromagnetic pieces and provides a first magnetic field at a workpiece contact interface of the magnetic coupling device; and the magnetic platter is positioned spaced apart from the one or more ferromagnetic pieces so that, when the magnetic platter is in the second state, the magnetic coupling device provides a second magnetic field at the workpiece contact interface, the second magnetic field having a non-zero magnetic field strength.

[0029] Other aspects and optional and / or preferred embodiments will become apparent from the following description provided below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0030] [Figure 1A] 1 shows a representative view of the front of an exemplary switchable magnetic device in an off state. [Figure 1B] 1B illustrates a representative view of the front of the exemplary switchable magnetic device shown in FIG. 1A in the ON state. [Figure 1C] 1C shows a representative view of a side view of the exemplary switchable magnetic device shown in FIGS. 1A and 1B. [Figure 2A] 1 shows a representative view of a side view of another exemplary switchable magnetic device. [Figure 2B] 2B shows a representative view of the top of the exemplary switchable magnet shown in FIG. 2A. [Figure 3] 1 shows a schematic exploded view of an exemplary switchable magnetic device with a pole shoe. [Figure 4] FIG. 4 shows an isometric view of the switchable magnetic device shown in FIG. 3 in an assembled state. [Figure 5A] FIG. 5 illustrates a cross-sectional front view of the switchable magnetic device shown in FIGS. 3 and 4 and the magnetic circuit created when the device is in the "off" state. [Figure 5B] FIG. 5 illustrates a cross-sectional front view of the switchable magnetic device shown in FIGS. 3 and 4 and the magnetic circuit created when the device is in the "on" state. [Figure 6] 1 illustrates a side view of a portion of an exemplary pole shoe. [Figure 7A] 10 shows a side view of a portion of another exemplary pole shoe. [Figure 7B] 7B shows a detailed view of a portion of the exemplary pole shoe shown in FIG. 7A. [Figure 8] 10 shows a side view of a portion of another exemplary pole shoe. [Figure 9A] 1 illustrates another exemplary electrode plate. [Figure 9B] 1 illustrates another exemplary electrode plate. [Figure 10A]1 illustrates another exemplary electrode plate. [Figure 10B] 1 illustrates another exemplary electrode plate. [Figure 11A] 1 illustrates a front view of another exemplary switchable magnetic device. [Figure 11B] FIG. 11B shows a side view of the switchable magnetic device shown in FIG. 11A. [Figure 12] 10 illustrates a process sequence of a method of use of an exemplary switchable magnetic device with a pole shoe. [Figure 13] 1 illustrates a robotic system including a switchable magnetic device. [Figure 14] 1 shows a schematic diagram of an exemplary magnetic coupling device having upper and lower assemblies each including a plurality of permanent magnets and pole pieces arranged in a linear array, the magnetic coupling device in an on state. [Figure 15] 15 shows the magnetic coupling device of FIG. 14 in an off state. [Figure 16] 1A-1C show perspective views of two instances of an exemplary platter having multiple permanent magnets and pole pieces. [Figure 17] 17 shows an exploded perspective view of the platter of FIG. 16. [Figure 18] 17 shows an assembled view of the top of the platter of FIG. 16. [Figure 19] FIG. 10 illustrates an exploded perspective view of another exemplary magnetic coupling device with a pole shoe. [Figure 20] 20 shows an assembled perspective view of the magnetic coupling device of FIG. 19. [Figure 21] FIG. 20 shows an assembled bottom view of the magnetic coupling device of FIG. 19. [Figure 22] 20 shows a cross-sectional view of the magnetic coupling device of FIG. 19. [Figure 23] 1 illustrates a cross-sectional view of another magnetic coupling device with an exemplary pole portion in an on state coupled to a ferromagnetic workpiece. [Figure 24] 24 illustrates a cross-sectional view of the magnetic coupling device shown in FIG. 23 in an exemplary off state positioned above a stack of multiple ferromagnetic workpieces. [Figure 25] 24 shows a bottom view of the magnetic coupling device of FIG. 23. [Figure 26] 24 illustrates a cross-sectional view of the magnetic coupling device of FIG. 23 with an exemplary pole shoe in an on state coupled to a ferromagnetic workpiece. [Figure 27] 27 illustrates a cross-sectional view of the magnetic coupling device shown in FIG. 26 in an exemplary off state positioned above a stack of multiple ferromagnetic workpieces. [Figure 28A] FIG. 1 illustrates a cross-sectional side view of another example magnetic coupling device in an example first off state positioned on a stack of ferromagnetic workpieces. [Figure 28B] 28B shows a front cross-sectional view of the magnetic coupling device of FIG. 28A. [Figure 29] 28A-28B in a second ON state. [Figure 30] FIG. 28C shows a cross-sectional front view of the magnetic coupling device of FIGS. 28A-28B in a third ON state. [Figure 31] 28A-28B show exploded views of the magnetic coupling device. [Figure 32A] 28A-28B at different positions on a ferromagnetic workpiece. [Figure 32B] 28A-28B at different positions on a ferromagnetic workpiece. [Figure 33] 10 illustrates a process sequence for a method of use of an exemplary switchable magnetic device with pole portions. DETAILED DESCRIPTION OF THE INVENTION

[0031] While the disclosed subject matter is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the specific embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure.

[0032] Detailed Description of the Drawings FIELD OF THE INVENTION The embodiments provided herein relate to switchable magnetic devices. An exemplary switchable magnetic device is described in U.S. Patent No. 7,012,495, entitled "SWITCHABLE PERMANENT MAGNETIC DEVICE," and in U.S. Patent No. 6,012,495, entitled "MODULAR MAGNETIC DEVICE." No. 7,161,451, entitled "PERMANENT MAGNET CHUCK," U.S. Patent No. 8,878,639, entitled "MAGNET ARRAYS," U.S. Provisional Patent Application No. 62 / 248,804, filed October 30, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," Attorney Docket No. MTI-0007-01-US-E, and U.S. Provisional Patent Application No. 62 / 252,435, filed November 7, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A LINEAR ACTUATION SYSTEM," Attorney Docket No. MTI-0006-01-US-E, the entire disclosures of which are expressly incorporated herein by reference.

[0033] The illustrated embodiments herein provide an exemplary switchable magnetic device having a first permanent magnet and a second permanent magnet movable relative to the first permanent magnet, similar to the exemplary switchable magnetic device of the '495 patent, which is expressly incorporated herein by reference. Each permanent magnet may be a cylindrical single dipole of one type of rare earth magnetic material, such as NdFeB or SmCo. Additional types of switchable magnetic devices may be implemented. Each type of switchable magnetic device includes at least a first permanent magnet movable relative to a second permanent magnet. Furthermore, exemplary switchable magnetic devices may include a first plurality of permanent magnets movable relative to a second plurality of permanent magnets. Furthermore, exemplary switchable magnetic devices may include at least a first permanent magnet positioned within a first housing that functions as a pole extension of the at least first permanent magnet, the first housing movable relative to a second housing having at least a second permanent magnet positioned therein, the second housing functioning as a pole extension of the at least second permanent magnet.

[0034] Additionally, an exemplary switchable magnetic device can include a first plurality of permanent magnets that are movable relative to a second plurality of permanent magnets. Two examples are provided in Figures 15-18. Exemplary systems are disclosed in U.S. Provisional Patent Application No. 62 / 248,804, filed October 30, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," Attorney Docket No. MTI-0007-01-US-E, and in U.S. Provisional Patent Application No. MTI-0007-01-US-E, filed October 30, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," and in U.S. Provisional Patent Application No. MTI-0007-01-US-E, filed October 30, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM." No. 62 / 252,435, filed November 7, 2015, entitled "A LINEAR ACTUATION SYSTEM," Docket No. MTI-0006-01-US-E, and U.S. Patent No. 7,161,451, the entire disclosures of which are expressly incorporated herein by reference.

[0035] 1A-1C, an exemplary switchable magnetic device 10 is shown. The switchable magnetic device 10 includes an upper permanent magnet 12 and a lower permanent magnet 14 positioned in a stacked relationship in a housing 28. The permanent magnet 12 includes a south pole portion 18 and a north pole portion 20. Similarly, the permanent magnet 14 includes a north pole portion 22 and a south pole portion 24. The housing 28 may include multiple components assembled together to form the housing. Additionally, the housing 28 includes , may include features to maintain permanent magnet 12 spaced apart from permanent magnet 14, or incorporate a spacer, such as spacer 13 in the illustrated embodiment, which maintains permanent magnet 12 in a spaced apart relationship relative to permanent magnet 14. Spacer 13 is made of a non-magnetic material to separate permanent magnet 12 from permanent magnet 14.

[0036] The pole shoes 16', 16" are coupled to a housing 28. The pole shoes 16', 16" are made of a ferromagnetic material and are magnetically coupled to the magnets 12, 14 through portions of the housing 28. A lower portion of each of the pole shoes 16', 16" includes a workpiece contact interface 17', 17" that can be brought into contact with a workpiece 27, illustratively the upper sheet 27' of ferromagnetic material of the stack of sheets 27', 27" and 27" of ferromagnetic material. The workpiece contact interface 17', 17" of the pole shoe 16', 16" cooperates with the magnets 12, 14 through the pole shoe 16', 16" and the housing 28 to form first and second poles of the magnets 12, 14. In one embodiment, one single pole shoe forms each of the pole shoes 16', 16". In another embodiment, multiple pole shoes form each of the pole shoes 16', 16".

[0037] In an embodiment, the permanent magnet 14 is fixed relative to the housing 28, and the permanent magnet 12 is movable within the housing 28 relative to the permanent magnet 14 to change the alignment of the magnet portions 18, 20 of the permanent magnet 12 relative to the magnet portions 22, 24 of the permanent magnet 14. In the illustrated embodiment, the permanent magnet 12 is rotatable relative to the permanent magnet 14.

[0038] Based on the configuration of permanent magnets 12, 14, switchable magnetic device 10 establishes two different magnetic circuits. Specifically, when permanent magnet 12 is rotated such that south-pole portion 18 of permanent magnet 12 is adjacent to south-pole portion 24 of permanent magnet 14 and north-pole portion 20 of permanent magnet 12 is adjacent to north-pole portion 22 of permanent magnet 14 (as shown in FIG. 1B), switchable magnetic device 10 establishes a first magnetic circuit, referred to as the on-state of switchable magnetic device 10. In the on state, one or more workpieces 27 made of a ferromagnetic material, such as iron or steel, are held by the switchable magnetic device 10 by completing a magnetic circuit from the aligned north-pole portions 20, 22 of each of the upper and lower magnets 12, 14, through the housing 28 and pole shoe 16', through one or more workpiece seats 27, through the pole shoe 16'' and housing 28, and to the aligned south-pole portions 18, 24 of each of the upper and lower magnets 12, 14. The workpiece contact interface 17' of the pole shoe 16' functions as the north pole of the switchable magnetic device 10. The workpiece contact interface 17'' of the pole shoe 16'' functions as the south pole of the switchable magnetic device 10.

[0039] As will be explained in more detail herein, the size and shape of the pole shoes 16', 16" causes the first magnetic circuit to substantially rest on the workpiece sheet 27' of the workpiece sheet 27, providing sufficient holding force to vertically lift the workpiece sheet 27' in the direction 33 relative to the rest of the workpiece sheet 27. Thus, the switchable magnetic device 10 may function to destack the workpiece sheet 27. Of course, in some embodiments, a portion of the magnetic flux provided to the workpiece sheet 27 by the switchable magnetic device 10 may enter the lower sheet 27'' of the workpiece sheet 27, but not to a level where the lower sheet 27'' would be lifted along with the workpiece sheet 27' by the switchable magnetic device 10. Thus, as used herein, the first magnetic circuit, which substantially remains on workpiece sheet 27' of workpiece sheet 27, refers to the amount of magnetic flux, if any, from switchable magnetic lifting device 10 that enters lower sheet 27'' as lower sheet 27'' is moved in direction 33 with workpiece sheet 27' by switchable magnetic lifting device 10. This means that it is below the level at which it will be raised vertically.

[0040] When permanent magnet 12 is rotated so that south-pole portion 18 of magnet 12 is adjacent north-pole portion 22 of permanent magnet 14 and north-pole portion 20 of permanent magnet 12 is adjacent south-pole portion 24 of permanent magnet 14 (as shown in FIG. 1A ), switchable magnetic device 10 establishes a second magnetic circuit, referred to as the off state of switchable magnetic device 10. In the off state, one or more workpieces 27 made of a ferromagnetic material, such as iron or steel, are not held by switchable magnetic device 10 due to the aligned south-pole portion 18 of magnet 12 and north-pole portion 22 of magnet 14, and the aligned north-pole portion 20 of magnet 12 and south-pole portion 24 of magnet 14 completing a magnetic circuit between switchable magnetic device 10 and workpiece sheet 27. In other words, the alignment of magnets 12, 14 effectively shunts the magnetic circuit within switchable magnetic device 10, weakening the external magnetic field. In one embodiment, at least 96% of the magnetic flux generated by the magnets 12, 14 is maintained at the switchable magnetic device 10 when the switchable magnetic device 10 is in the off state. In another embodiment, at least 99% of the magnetic flux generated by the magnets 12, 14 is maintained at the workpiece contact interface 17', 17''.

[0041] 1A , the switchable magnetic device 10 includes an engagement portion 30 and an actuator 32. The engagement portion 30 couples the actuator 32 to the permanent magnet 12 such that the actuator 32 can reorient the permanent magnet 12 relative to the permanent magnet 14. Exemplary engagement portions 30 include a recess or recesses in the permanent magnet 12 and / or the housing supporting the permanent magnet 12, one or more protrusions extending from the permanent magnet 12 and / or the housing supporting the permanent magnet 12, and / or one or more linkages or gear systems coupled to the permanent magnet 12 and / or the housing supporting the permanent magnet 12. Exemplary actuators include rotary actuators and linear actuators, each of which can impart rotation to the permanent magnet 12 through the engagement portion 30.

[0042] Exemplary engagement portions and actuators are disclosed in U.S. Patent No. 7,012,495, entitled "SWITCHABLE PERMANENT MAGNETIC DEVICE," U.S. Patent No. 7,161,451, entitled "MODULAR PERMANENT MAGNET CHUCK," U.S. Patent No. 8,878,639, entitled "MAGNET ARRAYS," U.S. Provisional Patent Application No. 62 / 248,804, filed October 30, 2015, Docket No. MTI-0007-01-US-E, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," and ... LINEAR ACTUATION No. 62 / 252,435, filed November 7, 2015, entitled "A METHOD AND APPARATUS FOR TRANSMITTING AN INTERFACE TO A SUBJECT MATTER" and Docket No. MTI-0006-01-US-E, the entire disclosure of which is expressly incorporated herein by reference.

[0043] In an embodiment, the actuator 32 is coupled to an electronic, pneumatic, or hydraulic controller 34 that controls the operation of the actuator 32 and, therefore, the alignment of the permanent magnet 12 relative to the permanent magnet 14 through the engagement portion 30. As illustrated in FIG. 1A , the controller 34 includes a processor 36 along with associated computer-readable media, illustratively a memory 38. The memory 38 includes magnetic coupling state logic 40 that, when executed by the processor 36, causes the electronic controller 34 to instruct the rotary actuator 32 to move the permanent magnet 12 so that the switchable magnetic device 10 is placed in one of an on state and an off state. As used herein, the term "logic" may refer to one or more programmable processors, application specific integrated circuits, field programmable gate arrays, digital signal processors, hardwired logic, or a combination thereof. Thus, according to an embodiment, various logic may be implemented in any suitable manner and be consistent with the embodiments disclosed herein. A non-transitory machine-readable medium containing logic may further be considered embodied in any tangible form of a computer-readable carrier, such as a solid-state memory, a magnetic disk, or an optical disk, containing a suitable set of computer instructions and data structures that cause a processor to execute the techniques described herein. The present disclosure provides that the magnetic coupling state logic is not microprocessor-based, but rather is configured to control operation of the switchable magnetic device 10 based on one or more sets of hardwired and / or software instructions stored in memory 38. Furthermore, controller 34 may be included within one device or may be multiple devices networked together to provide the functionality described herein.

[0044] In embodiments, the electronic controller 34 changes the state of the switchable magnetic device 10 in response to input signals received from an input device 42. Exemplary input devices include switches, buttons, touchscreens, microphones, detectors, controllers, and other devices by which an operator can provide one of tactile, audio, or visual input commands. For example, in one embodiment, the switchable magnetic device 10 is coupled to the end of a robotic arm, and the input device 42 is a network interface through which the controller 34 receives instructions from the robotic controller regarding when to place the switchable magnetic device in one of an on state and an off state. Exemplary network interfaces include wired network connections and antennas for wireless network connections. While the embodiments discussed above relate to electronic, pneumatic, or hydraulic actuation, in alternative embodiments, the switchable magnetic device 10 may be manually actuated. Exemplary manual actuators include handles, knobs, and other devices actuable by a human operator.

[0045] 1C , the pole shoe 16′, 16″ (the pole shoe 16″ shown) includes a plurality of protrusions 44 and recesses 46 separating the protrusions 44. In embodiments, the pole shoe 16′, 16″ can include any number of recesses 46 and any number of protrusions 44 disposed on each side of the recess 46. The recesses 46 are sized to prevent the workpiece 27 from entering each recess 46. Thus, the protrusions 44 collectively form the interface 17 for the workpiece 27. In one example, each of the pole shoes 16′, 16″ has a first number of protrusions 44 and a second number of recesses 46 interposed between the first number of protrusions, where the second number is at least two. In a variation thereof, the second number is at least three. In a further variation thereof, the second number is at least five.

[0046] As a result of the protrusions 44 and recesses 46, the switchable magnetic device 10 generates an external magnetic field 50 (shown in FIG. 1B) that is more concentrated near the interface 17 than the external magnetic field generated by the same magnetic device 10 when the pole shoes 16′, 16″ do not include the protrusions 44 and recesses 46. More specifically, as illustrated in FIG. 1B, the external magnetic field 50 substantially passes through the first workpiece 27′, but the magnetic field 50 does not substantially pass through either the second workpiece 27″ and / or the third workpiece 27′″. Although the magnetic field 50 shows that the magnetic field 50 does not substantially pass through the second workpiece 27″, some of the magnetic field 50 may leak into the second workpiece 27″. Conversely, if the pole shoes 16', 16" do not include the protrusions 44 and recesses 46, the external magnetic field 50 will tend to penetrate deeper into the second workpiece sheet 27" and / or the third workpiece sheet 27'" into the stack of workpiece sheets 27. This will cause the upper workpiece sheet 27' to move away from the second workpiece sheet 27". Less likely to be destacked.

[0047] Tables 1 and 2 show the average separation forces of switchable magnetic devices on workpieces having different thicknesses. Specifically, Table 1 shows switchable magnetic devices with a first type of magnet, where the first switchable magnetic device with the first type of magnet has a pole shoe without a protrusion 44, and the second switchable magnetic device 10 with the first type of magnet has a pole shoe 16', 16" with a protrusion 44. Table 2 shows switchable magnetic devices with a second type of magnet, where the first switchable magnetic device with the second type of magnet has a pole shoe without a protrusion 44, and the second switchable magnetic device 10 with the second type of magnet has a pole shoe 16', 16" with a protrusion 44.

[0048] [Table 1]

[0049] As the data shows, the switchable magnetic device 10 having pole shoes 16', 16'' with protrusions 44 performs better than the switchable magnetic device 10 having pole shoes without protrusions. The switchable magnetic device 10 having pole shoes 16', 16" with protrusions 44 has a higher average separation force on thinner workpieces than the magnetic device 10 having pole shoes 16', 16" with protrusions 44. Furthermore, as the thickness of the workpiece increases, the switchable magnetic device 10 having pole shoes 16', 16" with protrusions 44 has a lower overall average separation force.

[0050] As a result of the magnetic field 50 being concentrated near the interface 17 of the pole shoes 16′, 16″, the switchable magnetic device 10 including the pole shoes 16′, 16″ with the protrusions 44 and recesses 46 provides a more satisfactory destacking capability compared to the same switchable magnetic device 10 including a pole shoe without the protrusions and recesses. For example, the switchable magnetic device 10 including the pole shoes 16′, 16″ with the protrusions 44 and recesses 46 may be able to more satisfactorily destack thin sheet metal (e.g., 0.5 mm sheet metal, 1 mm sheet metal, 2 mm sheet metal, and / or the like) than the same switchable magnetic device 10 having a pole shoe without the protrusions 44 and recesses 46.

[0051] Additionally, the dimensions of the protrusions 44 and recesses 46 may be further configured to produce a varying magnetic field strength near the interface 44. That is, further concentration of the magnetic field 50 near the interface 17 of the pole shoes 16', 16" may be achieved by lengthening the pole shoes 16', 16" relative to the housing 28 and therefore relative to the magnets 12, 14. In embodiments, the upper and lower magnets 12, 14 and housing 28, which function as pole extension pieces for the magnets 12, 14, may have an outer envelope defined by a height 52 of the housing 28 (see FIG. 1B), a width 54 of the housing 28 (see FIG. 1B) extending on each side of a centerline 55 of the switchable magnetic device 10, and a length 58 of the housing 28 (see FIG. 1C). As shown in FIG. 1B, the pole shoe 16' is positioned on one side of the centerline 55 of the switchable magnetic device 10, and the pole shoe 16" is positioned on the opposite side of the centerline 55 of the switchable magnetic device 10. In one example, the pole shoes 16', 16" extend beyond at least one of the height 52, width 54, and / or length 58 of the envelope of the housing 28. In the illustrated embodiment, the pole shoes 16', 16" extend beyond the height 52 (lower than the housing 28, see FIG. 1B), width 54 (positioned outside the housing 28, see FIG. 1B), and length 58 (both in front and behind the housing 28, see FIG. 1C) of the envelope of the housing 28.

[0052] In some embodiments, the distance 60 (shown in FIG. 1A) between the bottom of the housing 28 and the interface 17 of the pole shoe 16', 16" and / or the length 62 (shown in FIG. 1C) of the pole shoe 16', 16" can be varied to generate different magnetic field strengths near the interface 17, as discussed below in connection with FIGS. 11A and 11B.

[0053] 1A-1C includes one upper magnet 12 and one lower magnet 14, in alternative embodiments, the switchable magnetic device 10 may include more than one upper magnet 12 and more than one lower magnet 14. One such example is shown in FIGS. 2A and 2B.

[0054] FIG. 2A is a representative side view of another exemplary switchable magnetic device 10', and FIG. 2B is a representative top view of the switchable magnetic device 10'. As illustrated in FIGS. 2A and 2B, the switchable magnetic device 10' includes a plurality of upper permanent magnets 12 and a plurality of lower permanent magnets 14, illustratively including three upper magnets 12', 12'', 12''', and three lower magnets 14', 14'', 14''. The upper and lower magnets 12', 14' form a first set of magnets 56'. The upper and lower magnets Stones 12'', 14'' form a second set of magnets 56''. Upper and lower magnets 12''', 14''' form a third set of magnets 56'''. The sets of magnets 56', 56'', 56''' are separated from each other.

[0055] Each set of magnets 56', 56", 56'" generates a magnetic field that propagates from the north pole of each of the set of magnets 56', 56", 56'" through the pole shoes 16', 16" to the south pole of each of the set of magnets 56', 56", 56'". In embodiments where the magnetic device 10' is in an on state, the magnetic field extends through the workpiece 27' when the workpiece 27' contacts the interface 17 of the pole shoes 16', 16". When the magnetic device 10' is in an off state, the magnetic field remains substantially within the magnetic device 10'. Although the pole shoes 16', 16" are illustrated as spanning the set of magnets 56', 56", 56'", in alternative embodiments, the switchable magnetic device 10' may include multiple pole shoes 16', 16" that collectively span the set of magnets 56', 56", 56'". Additionally or alternatively, the switchable magnetic device 10' may include sets of two, four, five, etc. magnets 56', 56'', 56'''.

[0056] Although the switchable magnetic device 10 is described as being in a stacked relationship, other switchable magnetic devices that do not have magnets in a stacked relationship may be used in association with the pole shoes 16', 16". An exemplary non-stacked switchable magnetic device is described in U.S. patent application Ser. No. 15 / 803,753, filed Nov. 4, 2017, entitled "MAGNET ARRAYS," the entire disclosure of which is expressly incorporated herein by reference.

[0057] Further details of the exemplary switchable magnetic device 100 will now be discussed in connection with Figures 3 and 4. Specifically, Figure 3 is a schematic exploded view of the exemplary switchable magnetic device 100 including ferromagnetic pole shoes 102', 102", and Figure 4 is an isometric view of the switchable magnetic device 100 in an assembled state. Further details regarding the magnetic device 100 are provided in U.S. Provisional Patent Application No. 62 / 517,057, filed June 8, 2017, entitled "ELECTROMAGNET-SWITCHABLE PERMANENT MAGNET DEVICE," the entire disclosure of which is expressly incorporated herein by reference.

[0058] 3 and 4, reference is also made to Figure 5A, which is a cross-sectional front view of the switchable magnetic device 100 and the magnetic circuit that is generated when the device is in a first configuration, or off state. Reference is also made to Figure 5B, which is a cross-sectional front view of the switchable magnetic device 100 when the magnetic device 100 is in a second configuration, or on state.

[0059] The magnetic device 100 may have multiple configurations that result in establishing different magnetic circuits. For example, by switching the magnetic device 100 from a second configuration (shown in FIGS. 3 and 5A) in which the magnetic device 100 establishes a second magnetic circuit to a first configuration (shown in FIG. 5B) in which the magnetic device 100 establishes a first magnetic circuit, a ferromagnetic body may be coupled to the magnetic device 100 via the pole shoes 102′, 102″, as described below.

[0060] The magnetic device 100 comprises a central housing 104. The central housing 104 contains two ferromagnetic (e.g., steel) housing components 106, 108 that may be joined by fasteners (not shown). The housing components 106, 108 may additionally or alternatively be joined using other methods and materials (e.g., epoxy, locating features (protrusions, recesses, chamfers, molded keyways, and / or the like), etc.). Housing component 106 may be referred to herein as upper housing component 106, and housing component 108 may be referred to herein as lower housing component 108. Additionally, pole shoes 102', 102'' may be coupled to housing 104 with fasteners (not shown).

[0061] In an embodiment, the housing components 106, 108 may be rectangular blocks of low-reluctance ferromagnetic material. A cylindrical cavity 110 may extend through the upper housing component 106, and a cylindrical cavity 112 may extend through the lower housing component 108. The cylindrical cavities 110, 112 may be perpendicular to the top surfaces 114, 116 of the respective housing components 106, 108. The cylindrical cavity 110 may be referred to herein as the upper cylindrical cavity 110, and the cylindrical cavity 112 may be referred to herein as the lower cylindrical cavity 112. In an embodiment, the cylindrical cavities 110, 112 may receive magnets 118, 120, respectively. The magnet 118 may be referred to herein as the upper magnet 118, and the magnet 120 may be referred to herein as the lower magnet 120.

[0062] The upper housing component 106 has two side walls 124', 124" and the lower housing component 108 has two side walls 126', 126". In an embodiment, the side walls 124', 124" of the upper housing component 106 and the side walls 126', 126" of the lower housing component 108 may have a thickness that includes the magnetic field generated by the magnets 118, 120 within the housing components 106, 108 when the magnetic device 100 is in the first configuration (shown in FIG. 5A ).

[0063] In an embodiment, the upper magnet 118 has a N-S axis 128 and the lower magnet 120 has a N-S axis 130. The magnets 118, 120 may be NdFeB magnets, and the active magnetic mass and magnetic properties of the magnets 118, 120 may be equal and / or equal within achievable manufacturing tolerances and permanent magnet magnetization technology.

[0064] In an embodiment, the lower magnet 120 is received in the lower cylindrical cavity 112 and rotationally fixed with its N-S axis 130 extending from side wall 126' to side wall 126" (see FIG. 1). As a result, the side walls 126', 126" are magnetized according to the active magnetic pole of their neighbors. That is, the side wall 126' is magnetized as a N-pole, while the side wall 126" is a S-pole. In contrast, the upper magnet 118 is free to rotate about the axis 122 without the pole shoes 102', 102" and therefore the polarity of the side walls 124', 124" is determined by the relative rotational position and orientation of the upper magnet 118.

[0065] As mentioned above, the upper magnet 118 is configured to be rotated from the orientation shown in FIG. 3. In an embodiment, the upper magnet 118 may be rotatable 180-185 degrees to a rotational position (see FIG. 5B) where its north-south pole is aligned with the north-south pole of the lower magnet 120 and, conversely, the south-south poles overlap each other. When the north-south axes 128, 130 are oriented parallel, both sidewalls 124', 126' are magnetized with the same north magnetic polarity, as is the adjacent pole shoe 102'. Furthermore, the sidewalls 124'', 126'' are magnetized with the same south magnetic polarity, as is the adjacent pole shoe 102''. This reorientation of the upper magnet 118 creates an "active" operating air gap at the axial workpiece contact interface 132', 132'' below the pole shoes 102', 102'', thereby enabling a low-reluctance closed magnetic circuit to be formed. Specifically, a low-reluctance closed magnetic circuit begins and ends at the magnets 118, 120 through the ferromagnetic material that may contact both the side walls 124', 124'', 126', 126'', the pole shoes 102', 102'', and the workpiece contact interfaces 132', 132'' of the pole shoes 102', 102''. This state may be referred to herein as the magnetic device 100 being in an ON state (see FIG. 5B). Conversely, when the N-S axes 128, 130 are oriented oppositely parallel, In this state, a closed magnetic circuit is formed within the magnetic device 100, and the magnetic device 100 may be said to be in an off state (see FIG. 5A).

[0066] The upper cylindrical cavity 110 may have a smooth wall surface and a diameter that allows the upper magnet 118 to be received therein so that it can rotate with minimal friction about the N-S axis 128, preferably maintaining a minimal air gap. In an embodiment, a friction-reducing coating may be applied to the upper cylindrical cavity 110. The lower cylindrical cavity 112 may have a rough wall surface and diameter that provides an interface fit with the lower magnet 120 so that when the lower magnet 120 is mounted within the lower cylindrical cavity 112, it maintains its rotational orientation and prevents axial and rotational displacement under operating conditions of the magnetic device 100. Additionally or alternatively, other mechanisms, such as adhesives or additional cooperating form-fitting components (not shown), may be used to secure the lower magnet 120 within the lower cylindrical cavity 112.

[0067] A circular disk 134 constructed of a ferromagnetic material may be disposed at the bottom of the lower cylindrical cavity 112. The circular disk 134 may support the lower magnet 120. In embodiments, the circular disk 134 may be press-fit or otherwise secured to close the lower end of the lower cylindrical cavity 112 and seal the lower cylindrical cavity 112 and lower magnet 120 against contamination at an operating surface 136 of the magnetic device 100. The ferromagnetic nature of the circular disk 134 helps complete the magnetic circuit by providing additional magnetizable material between the sidewalls 126′, 126″, so that the field of the lower magnet 120 couples exclusively with the magnetic material provided in the lower housing component 108 and the pole shoes 102′, 102″ to form a magnetic circuit in either the on or off state. This also allows the magnetic device 100 to operate with a greater coercive force when turned on and to negate any coercive force when turned off.

[0068] In embodiments, a support structure 138 may be located between the magnets 118, 120. The support structure 138 may support the upper magnet 118 within the upper cylindrical cavity 110. Additionally or alternatively, the support structure 138 may facilitate maintaining a set axial distance between the lower circular surface of the upper magnet 118 and the upper circular surface of the lower magnet 120. In embodiments, the support structure 138 may include a circular bottom plate 140 of a non-magnetizable metallic material, a rotation bearing 142, and a circular non-magnetic upper plate 144. In embodiments, the bottom plate 140 rests on the upper surface of the lower magnet 120 and closes the upper open end of the lower cylindrical cavity 112. In embodiments, the bottom plate 140 may be intermediate-fit within the open end of the lower cylindrical cavity 112. The rotation bearing 142 may be mounted in an appropriately sized cylindrical recess (or seat) in the upper surface of the bottom plate 140. The diameter of upper plate 144 is such that it can rotate within the lower terminal axial end of upper cylindrical cavity 110. That is, upper plate 144 may have a diameter similar to that of upper magnet 118, which seats on upper plate 144 at its lower axial end face. In embodiments, the upper surface of upper plate 144 may be coated with a slip-promoting PTFE coating, and the lower surface of upper plate 144 may include a boss or axial post (not shown). In embodiments, the axial post may seat within an inner ring bearing portion of rotation bearing 142. Additionally or alternatively, a non-magnetizable (e.g., aluminum) circular cap (not shown) may be attached to upper housing component 106 to cover upper cylindrical cavity 110.

[0069] In an embodiment, the support structure 138 may be replaced by a different type of arrangement in which the upper magnet 118 is fixed relative to the shaft 146 but is allowed to rotate freely by a retainer clip ring (not shown) secured in an annular groove (not shown) near the lower end of the shaft 146.

[0070] In an embodiment, the shaft 146 extends through a hole 148 in the upper magnet 118, such that the upper magnet 118 can rotate coaxially about the shaft 146. In an embodiment, the shaft 146 protrudes perpendicularly from a central hub portion 152 of the cap component 150, such that positioning of the shaft 146 by installation of the cap component 150 cooperates with the upper magnet 118 to ensure its concentric rotation within the cylindrical cavity of the upper housing component 106. In the illustrated embodiment, the shaft 146 is a cylindrical pin welded or otherwise secured to the cap component 150.

[0071] In embodiments, the cap component 150 may be non-magnetizable and may include a rectangular plate 154 with an arched window 156. In embodiments, the rectangular plate 154 may be machined to have a footprint similar to that of the housing components 106, 108, i.e., a rectangular footprint. The distal end of the distal window 156 provides a "hard stop" for a rotation-preventing block member 158 secured to the upper magnet 118 such that the block member 158 may move within the arched window 156 during rotation of the upper magnet 118 as the magnetic device 100 switches between configurations. In embodiments, the arched window 156 may include a latching mechanism 160 that operates to hold the upper magnet 118 in an intermediate rotational state between the hard stops provided by the ends of the arched window 156. Thus, the upper magnet 118 may be secured at an intermediate rotational position relative to the lower magnet 120. Additionally or alternatively, the latching mechanism 160 may be included in the upper housing component 106 or another portion of the magnetic device 100.

[0072] In one embodiment, the shaft 146 is coupled to an actuator 32 that moves the upper magnet 118 to various positions relative to the lower magnet 120. In the illustrated embodiment, one or more solenoid coil bodies 162 surround the upper housing 106 and orient the upper magnet 118 relative to the lower magnet 120 through one or more electrical currents passing through the solenoid coil bodies 162. The solenoid coil bodies 162 may be comprised of wrapped (or otherwise laid) enamel-coated wire windings. In an embodiment, the enamel-coated wire may be comprised of one or more electrically conductive materials (e.g., copper, silver, gold, and / or the like).

[0073] Cap component 150 may further be configured to support / house various associated electronic control and power components required to supply current to solenoid coil body 162 to rotate upper magnet 118, as described below. Alternatively, cap component 150 may include contact leads for connection to a power source (not shown) that supplies current to solenoid coil body 162. In an embodiment, cap component 150 may be secured to upper housing component 106 using bolts or other types of fasteners.

[0074] In embodiments, a power source (not shown) may be connected to the solenoid coil body 162 via suitable control circuitry to supply current to the solenoid coil body 162. In response to the current supplied to the solenoid coil body 162, the solenoid coil body 162 generates a magnetic field. In embodiments, the magnetic field generated by the solenoid coil body 162 is oriented in a manner that generates a torque on the upper magnet 118. The torque rotates the N-S axis 128 of the upper magnet 118 from a first configuration (shown in FIG. 5A ) to a second configuration (shown in FIG. 5B ). Additionally or alternatively, the upper magnet 118 may be stopped in various intermediate configurations by the latch mechanism 160.

[0075] In embodiments, the magnets 118, 120 may have different magnetization and coercivity characteristics. For example, the lower magnet 120 may be composed of a high-coercivity permanent magnet that cannot be easily demagnetized by external magnetizing influences, while the upper magnet 118 may be composed of a medium or low-coercivity magnetic element. Therefore, the magnetic field generated by the solenoid coil body 162 may affect the upper magnet 118 to a greater extent than the lower magnet 120.

[0076] In embodiments, the solenoid coil body 162 may comprise multiple solenoid coil bodies. For example, the solenoid coil body 162 may comprise two solenoid coil bodies that are electrically isolated from one another and extend from one corner of the upper housing component 106, diagonally across the top surface of the upper housing component 106, to the opposing corner of the upper housing component 106, and below the upper housing component 106 to complete a winding. Each coil may be wound on opposing diagonals across the upper housing component 106 and the cap component 150, one coil wound over the other, so that they form an "X" of windings when viewed in a plan view of the top of the upper housing component 106. Although the magnetic device 100 is described herein as being electrically actuated by the solenoid coil body 162, in embodiments, the magnetic device 100 may be actuated with an electric actuator through a mechanical connection, such as a motor, a pneumatic actuator, a hydraulic actuator, or a manual actuator.

[0077] As shown, threaded bores 164 may be cut into the side walls 124′, 124″, 126′, 126″. The threaded bores 164 may facilitate fastening the pole shoes 102′, 102″ to the housing components 106, 108 via fastening screws or bolts (not shown). That is, the fastening screws or bolts may be inserted through countersunk through-bores 166 in the pole shoes 102′, 102″, whose spacing is equal to the spacing of the threaded bores 164. Thus, both housing components 106, 108 may be connected to the pole shoes 102′, 102″ in a manner that provides a low-reluctance magnetic circuit path with substantially no gaps between the magnets 118, 120, the side walls 124′, 124″, 126′, 126″, and the pole shoes 102′, 102″.

[0078] The pole shoes 102', 102" provide a ferromagnetic workpiece contact interface to the magnetic device 100. In an embodiment, the pole shoes 102', 102" may be constructed of a low magnetic reluctance ferromagnetic material. Although the pole shoes 102', 102" are shown as having a parallelepiped, plate-like shape, the pole shoes 102', 102" may have other shapes that may be based on the shape of the workpiece to which the magnetic device 100 is attached. One example is the cylindrical shape shown in FIGS. 9A-9B that matches the cylindrical shape of a workpiece, such as a pipe. Another example is the V-shape shown in FIGS. 10A-10B that matches an edge or corner of the workpiece.

[0079] As shown, the pole shoe 102′, 102″ includes portions 168′, 168″ positioned proximate the housing components 106, 108. As described above, these portions 168′, 168″ are secured to the housing components 106, 108 via one or more fastening devices (e.g., screws, etc.). Additionally, the pole shoe 102′, 102″ includes a plurality of protrusions 170′, 170″, also referred to herein as projections. The plurality of protrusions 170′, 170″ each collectively form a workpiece contact interface of the pole shoe 102′, 102″. In embodiments, the pole shoe 102′, 102″ including the plurality of protrusions 170′, 170″ generates a shallower magnetic field than a pole shoe having a flat workpiece contact interface, as illustrated in the examples provided herein.

[0080] FIG. 6 is a side view of a portion of an exemplary pole shoe 200 that can function as either the pole shoe 132′ or the pole shoe 132″ of the magnetic device 100. The pole shoe 200 includes a first portion 202 that can be positioned proximate to a housing (e.g., housing 104) of a magnetic device (e.g., magnetic device 100). The pole shoe 200 also includes a bore 204 extending through the pole shoe 200 to releasably secure the pole shoe 200 to a housing of a magnetic device via a fastening mechanism (e.g., a fastening screw, etc.). Furthermore, the pole shoe 200 includes a plurality of protrusions 206 disposed on a bottom portion 208 of the pole shoe 200. Each of the protrusions 206 is separated by a recess 210. Furthermore, the plurality of protrusions 206 collectively form a workpiece contact interface 212 of the pole shoe 200.

[0081] As mentioned above, due to the multiple protrusions 206 included on the pole shoe 200, a magnetic device including the pole shoe 200 generates a stronger magnetic field near the workpiece contact interface 212 than a magnetic device including a pole shoe with a continuous downward contour of the same height. The magnetic field generated near the workpiece contact interface 212 may be referred to herein as a shallow magnetic field. Furthermore, by including multiple protrusions 206 on the pole shoe 200, a magnetic device including the pole shoe 200 generates a weaker magnetic field in depth further from the pole shoe 200 than a magnetic device including a pole shoe with a continuous downward contour of the same height. The magnetic field generated further from the pole shoe 200 may be referred to herein as a far or deep magnetic field generated by the pole shoe 200. In other words, a magnetic device including a pole shoe 200 with protrusions 206 has a stronger holding force near the workpiece contact interface 212 than a magnetic device including a pole shoe with a continuous interface of the same height that does not include protrusions 206.

[0082] In an embodiment, the shallow magnetic field and far magnetic field of the pole shoe 200 may depend on the type of pole shoe 200. Specifically, the shallow magnetic field may be a magnetic field generated from the workpiece contact interface 212 to a distance from the workpiece contact interface 212 approximately equal to the width 214 of the protrusion 206. For example, if the width 214 of the protrusion 206 is 2 mm, the shallow magnetic field is a magnetic field generated from the workpiece contact interface 212 to a depth of 2 mm from the workpiece contact interface 212. Furthermore, the far magnetic field generated in this example is a magnetic field generated at a depth greater than 2 mm from the workpiece contact interface 212.

[0083] Because the protrusions 206 of the pole shoe 200 cause the magnetic device 100 to generate a stronger shallow magnetic field and a weaker far-field, the magnetic device 100 can be used to more effectively destack thin ferromagnetic objects than a magnetic device 100 having a pole shoe without the protrusions 206. That is, a magnetic device 100 including a pole shoe without the protrusions 206 may generate a stronger far-field that would result in multiple thin ferromagnetic objects being coupled to the magnetic device. This is an undesirable result when attempting to obtain a single thin ferromagnetic object from a stacked array of thin ferromagnetic objects. Therefore, instead of using a magnetic device including a pole shoe without the protrusions 206 to destack ferromagnetic objects, a pole shoe 200 including the protrusions 206 can be used.

[0084] In embodiments, varying the width 214 of the protrusions 206 can result in different shallow magnetic fields being generated by the same magnetic device. In embodiments, to generate a preferred shallow magnetic field for a particular ferromagnetic material, the width 214 of the protrusions 206 can be within about + / - 25% of the thickness of the ferromagnetic material being destacked. For example, when the magnetic device destacks a 2 mm thick ferromagnetic sheet, the width 214 of the protrusions 206 can be about 2 mm (e.g., 2 mm + / - 25%). In embodiments, this generates a strong shallow magnetic field at a depth of 0 mm to 2 mm from the contact interface 212. However, in at least one embodiment, there may be a limit to generating a preferred shallow magnetic field for some ferromagnetic materials having a thickness below a certain limit. That is, for ferromagnetic materials having a thickness less than X mm, a preferred shallow magnetic field may be generated with a width 214 that is at or above the lower limit of X mm. A desired magnetic field may be generated by a protrusion 206 having a thickness of ½*X mm. That is, to generate a desired magnetic field for a ferromagnetic material having a thickness of ½*X mm, the width 214 of the protrusion 206 may be a lower limit of X mm instead of ±25% of ½*X mm. However, if the thickness of the ferromagnetic material is X mm or greater, the width 214 may be approximately equal to the thickness of the ferromagnetic material (e.g., ±25%). An example of a lower limit may be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0085] In at least one embodiment, when a magnetic device including the pole shoe 200 is coupled to ferromagnetic materials having different thicknesses, a pole shoe 200 having a width 214 that is the average of the thicknesses of the ferromagnetic materials may be used to reduce the need to modify the pole shoe. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that if the average thickness of the ferromagnetic materials is less than the lower limit (i.e., <2.0 mm), the width 214 may be configured to be the lower limit (i.e., 2.0 mm).

[0086] In embodiments, by varying the depth 216 and / or width 218 of the recess 210, different shallow magnetic fields can be generated by the same magnetic device 100. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic material, the depth 216 and / or width 218 of the recess 210 can be approximately the same as (e.g., + / - 25%) the width 214 of the protrusion 206. For example, if the width 214 of the protrusion 206 is 2 mm, the depth 216 and / or width 218 of the recess 210 can be approximately 2 mm (e.g., 2 mm + / - 25%). In embodiments, this generates a strong shallow magnetic field at a depth of 0 mm to 2 mm from the contact interface 212. However, as above, there may be a limit to generating a preferred shallow magnetic field for some ferromagnetic materials having a thickness below a certain limit. That is, for a ferromagnetic material having a thickness less than X mm, a preferred shallow magnetic field can be generated by a depth 216 and width 218 that is at or above the lower limit of X mm. That is, to generate a favorable magnetic field for a ferromagnetic body having a thickness of ½*X mm, the depth 216 and width 218 may be a lower limit of X mm instead of + / −25% of ½*X mm. However, if the thickness of the ferromagnetic body is X mm or greater, the depth 216 and width 218 may be approximately equal to the thickness of the ferromagnetic body (e.g., + / −25%).

[0087] Similar to the above, when a magnetic device 100 including a pole shoe 200 couples ferromagnetic materials having different thicknesses, a pole shoe 200 having a depth 216 and / or width 218 of the recess 210 that is the average of the thicknesses of the ferromagnetic materials may be used to reduce the need to modify the pole shoe. Furthermore, a lower limit (e.g., 2.0 mm) may apply, such that if the average thickness of the ferromagnetic materials is less than the lower limit (i.e., <2.0 mm), the depth 216 and width 218 may be configured to be the lower limit (i.e., 2.0 mm).

[0088] As described above, the pole shoe 200 may be releasably coupled to the housing of the magnetic device. Thus, when the protrusion 206 of the pole shoe 200 does not have a width 214, depth 216, and / or width 218 suitable for the ferromagnetic material to which the magnetic device 100 is coupled, the pole shoe 200 may be replaced with a more suitable pole shoe 200.

[0089] FIG. 7A is a side view of a portion of another exemplary pole shoe 300 that can function as either the pole shoe 132′ or the pole shoe 132″ of the magnetic device 100, and FIG. 7B shows a detailed view of the portion of the exemplary pole shoe shown in FIG. 7A. Similar to the pole shoe 200 shown in FIG. 6, the pole shoe 300 comprises a first portion 302 that can be positioned proximate to a housing (e.g., housing 104) of a magnetic device (e.g., magnetic device 100). The pole shoe 300 also includes a bore 304 extending through the pole shoe 300 to allow for attachment of the pole shoe 300 to a magnetic device via a fastening mechanism (e.g., a fastening screw, etc.). The pole shoe 300 may be releasably secured to the housing 104 of the magnetic device 100. Further, the pole shoe 300 includes a plurality of protrusions 306 disposed on a bottom portion 308 of the pole shoe 300. Each of the protrusions 306 is separated by a recessed portion 310. The plurality of protrusions 306 collectively form a workpiece contact interface 312 of the pole shoe 300.

[0090] Similar to the above, by varying the width 314 of the protrusions 306 and / or the depth 316 and / or width 318 of the recesses 310, different shallow magnetic fields will be generated by the same magnetic device 100. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic material, the width 314 of the protrusions 306 and / or the depth 316 and / or width 318 of the recesses 310 may be approximately the same (e.g., + / - 25%) as the thickness of the ferromagnetic material coupled to the magnetic device 100. However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic materials having thicknesses below a limit. That is, for a ferromagnetic material having a thickness less than X mm, a preferred shallow magnetic field may be generated by a width 314, depth 316, and / or width 318 that is at or above the lower limit of X mm. That is, to generate a favorable magnetic field for a ferromagnetic body having a thickness of ½*X mm, width 314, depth 316, and / or width 318 may be at a lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic body is X mm or greater, width 314, depth 316, and / or width 318 may be approximately equal to (e.g., + / - 25%) the thickness of the ferromagnetic body. An example of a lower limit may be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0091] Alternatively, when a magnetic device including the pole shoe 300 is coupled to ferromagnetic materials having different thicknesses, a pole shoe 300 having a width 314, depth 316, and / or width 318 that is about the average of the thickness of the ferromagnetic materials may be used to reduce the need to modify the pole shoe. However, similar to above, if the average thickness of the ferromagnetic materials is less than the lower limit (i.e., <2.0 mm), a lower limit (e.g., 2.0 mm) may apply, such that the width 314, depth 316, and / or width 318 may be configured to be at the lower limit (i.e., 2.0 mm).

[0092] In an embodiment, the upper portion 319 of the pole shoe 300 has a continuous sloped profile (a slope defined at all points, with no sharp corners). Illustratively, the upper corner 319 of the pole shoe 300 may have a rounded shoulder portion 320. Magnetic devices 100 including pole shoes 300 with rounded shoulders 320 have been shown to have higher magnetic flux transfer to ferromagnetic materials than magnetic devices including pole shoes with sharp corners. Accordingly, in at least one embodiment, the upper corner 319 of the pole shoe 300 includes a rounded shoulder portion 320. In one example, the radius of curvature 322 of the rounded shoulder portion 320 may preferably be in the range of 1% to 75% of the height 323 of the pole shoe 300. In another example, the radius of curvature 322 may preferably be in the range of 25% to 75% of the height 323 of the pole shoe 300. In a further example, the radius of curvature 322 may preferably be in the range of 40% to 60% of the height 323 of the pole shoe 300.

[0093] 7B, additionally or alternatively, the recesses 310 between the protrusions 306 may have a continuous sloped profile (a slope defined at all points, with no sharp corners) at their upper ends. Similar to having a rounded shoulder 320, a magnetic device including a pole shoe 300 with a curved recess 310 may have a higher magnetic flux transfer to a ferromagnetic material than a magnetic device including a pole shoe with a recess with sharp corners. In an embodiment, to provide high magnetic flux transfer, the radius of curvature 324 of the curved recess 310 may be about 1 / 2 the width 318 of the recess 310. Test data indicates that a recess 310 with a radius of curvature 324 that is 1 / 2 the width 318 of the recess 324 ... shows that an improvement of over 3% can be obtained by including a gradient profile of

[0094] FIG. 8 is a side view of a portion of another exemplary pole shoe 400 that can function as either the pole shoe 132′ or the pole shoe 132″ of the magnetic device 100. Similar to the pole shoes 200, 300 shown in FIGS. 6 and 7A-7B, respectively, the pole shoe 400 includes a first portion 402 that can be positioned proximate to a housing (e.g., the housing 104) of a magnetic device (e.g., the magnetic device 100). The pole shoe 400 also includes a bore 404 extending therethrough to releasably secure the pole shoe 400 to the housing of the magnetic device via a fastening mechanism (e.g., a fastening screw, etc.). Additionally, the pole shoe 400 includes a plurality of protrusions 406 disposed on a bottom portion 408 of the pole shoe 400. Each of the protrusions 406 is separated by a recess 410. The plurality of protrusions 406 collectively form a workpiece contact interface 412 of the pole shoe 400.

[0095] Similar to the above, by varying the width 414 of the protrusion 406 and / or the depth 416 and / or width 418 of the recess 410, different shallow magnetic fields will be generated by the same magnetic device 100. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic material, the width 414 of the protrusion 406 and / or the depth 416 and / or width 418 of the recess 410 may be approximately the same as the thickness of the ferromagnetic material (e.g., + / - 25%). However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic materials having a thickness below a certain limit. That is, for ferromagnetic materials having a thickness less than X mm, a preferred shallow magnetic field may be generated by a width 414, depth 416, and / or width 418 that is at or above the lower limit of X mm. That is, to generate a preferred magnetic field for a ferromagnetic material having a thickness of ½*X mm, the width 414, depth 416, and / or width 418 may be at the lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic material is X mm or greater, then width 414, depth 416, and / or width 418 can be approximately equal to the thickness of the ferromagnetic material (e.g., + / - 25%). A lower limit example can be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0096] Alternatively, when a magnetic device including the pole shoe 400 is coupled to ferromagnetic materials having different thicknesses, a pole shoe 400 having a width 414, depth 416, and / or width 418 that is the average of the thicknesses of the ferromagnetic materials may be used to reduce the need to modify the pole shoe. However, similar to above, if the average thickness of the ferromagnetic materials is less than the lower limit (i.e., <2.0 mm), a lower limit (e.g., 2.0 mm) may apply, such that the width 414, depth 416, and / or width 418 may be configured to be at the lower limit (i.e., 2.0 mm).

[0097] In embodiments, the pole shoe 400 may also include a compressible member 420 disposed between the protrusions 406 at the recesses 410. In embodiments, when the magnetic device 100 including the pole shoe 400 is coupled to a ferromagnetic body, the compressible member 420 compresses. The compression of the compressible member 420 creates a static friction between the compressible member 420 and the ferromagnetic body that is potentially greater than the static friction between the protrusions 406 and the ferromagnetic body. Thus, a ferromagnetic body coupled to the magnetic device 100 including the pole shoe 400 may be less likely to rotate and translate than if the ferromagnetic body were coupled to a pole shoe that does not include the compressible member 420. In embodiments, the compressible member 420 may be composed of a resilient material, such as a polymer of isoprene, polyurethane, nitrile rubber, and / or the like.

[0098] 9A-9B show the pole shoe 132' or the pole shoe 132' of the magnetic device 100. 32''。 Similar to plates 200, 300, 400 shown in Figures 6, 7A-7B, and 8, plate 500 includes a plurality of protrusions 502 disposed on a bottom portion 504 of plate 500. Each of protrusions 502 is separated by a recess 506. The plurality of protrusions 502 collectively form a workpiece contact interface 508 of plate 500.

[0099] As shown, workpiece contact interface 508 is non-planar. In embodiments, a non-planar workpiece contact interface 508 may facilitate coupling magnetic coupling device 100 to a ferromagnetic workpiece having a non-planar surface. For example, magnetic coupling device 100 including pole plate 500 may be used to couple magnetic coupling device 100 to one or more types of rods, shafts, etc. (e.g., camshafts). Although workpiece contact interface 508 includes curved surface 510, workpiece contact interface 508 may have any other type of non-planar surface. For example, workpiece contact interface 508 may include a contour similar to the ferromagnetic piece with which a magnetic coupling device including workpiece contact interface 508 is intended to couple.

[0100] Despite having a non-planar workpiece contact interface 508, different shallow magnetic fields can be generated by the same magnetic coupling device by varying the width 512 of the protrusions 502 and / or the depth 514 and / or width 516 of the recesses 506. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece, the width 512 of the protrusions 502 and / or the depth 514 and / or width 516 of the recesses 506 can be approximately the same as the thickness of the ferromagnetic workpiece (e.g., + / - 25%). However, in at least one embodiment, there can be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces having thicknesses below a certain limit. That is, for a ferromagnetic workpiece having a thickness less than X mm, a preferred shallow magnetic field can be generated by a width 512, depth 514, and / or width 516 that is at or above the lower limit of X mm. That is, to generate a favorable magnetic field for a ferromagnetic workpiece 102 having a thickness of ½*X mm, width 512, depth 514, and / or width 516 may be at a lower limit of X mm instead of + / −25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece is X mm or greater, width 512, depth 514, and / or width 516 may be approximately equal to (e.g., + / −25%) the thickness of the ferromagnetic workpiece. An example of a lower limit may be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0101] Alternatively, when a magnetic coupling device including pole plate 500 is coupled to ferromagnetic workpieces having different thicknesses, pole plate 500 having width 512, depth 514, and / or width 516 that is average of the thickness of the ferromagnetic workpieces may be used to reduce the need to change pole plates. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that width 512, depth 514, and / or width 516 may be configured to be at the lower limit (i.e., 2.0 mm) if the average thickness of ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm).

[0102] 10A-10B illustrate another exemplary pole plate 550 that can be used as either the pole shoe 132′ or the pole shoe 132″ of the magnetic device 100. Similar to the pole plates 200, 300, 400, and 500 shown in FIGS. 6, 7A-7B, 8, and 9A-9B, the pole plate 550 includes a plurality of protrusions 552 disposed on a bottom portion 554 of the pole plate 550. Each of the protrusions 552 is separated by a recessed portion 556. The plurality of protrusions 552 collectively form a workpiece contact interface 558 of the pole plate 550.

[0103] As shown, workpiece contact interface 558 is non-planar. In embodiments, a non-planar workpiece contact interface 558 may facilitate coupling magnetic coupling device 100 to a ferromagnetic workpiece having a non-planar surface. For example, a magnetic coupling device including pole plate 550 may be used to couple magnetic coupling device 100 to one or more edges, corners, etc. of a ferromagnetic workpiece. Workpiece contact interface 558 includes two downwardly sloping surfaces 560 extending from a center point 562, although workpiece contact interface 558 may have any other type of non-planar surface. For example, workpiece contact interface 558 may include a contour similar to the ferromagnetic piece with which a magnetic coupling device including workpiece contact interface 558 is intended to couple.

[0104] Despite having a non-planar workpiece contact interface 558, different shallow magnetic fields will be generated by the same magnetic coupling device by varying the width 564 of the protrusions 552 and / or the depth 566 and / or width 568 of the recesses 556. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece, the width 564 of the protrusions 552 and / or the depth 566 and / or width 568 of the recesses 556 may be approximately the same as the thickness of the ferromagnetic workpiece (e.g., + / - 25%). However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces having thicknesses below a certain limit. That is, for a ferromagnetic workpiece having a thickness less than X mm, a preferred shallow magnetic field may be generated by a width 564, depth 566, and / or width 568 that is at or above the lower limit of X mm. That is, to generate a favorable magnetic field for a ferromagnetic workpiece having a thickness of ½*X mm, width 564, depth 566, and / or width 568 may be at a lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece is X mm or greater, width 564, depth 566, and / or width 568 may be approximately equal to (e.g., + / - 25%) the thickness of the ferromagnetic workpiece. An example of a lower limit may be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0105] Alternatively, when a magnetic coupling device including pole plate 550 is coupled to ferromagnetic workpieces 102 having different thicknesses, pole plate 550 having width 564, depth 566, and / or width 568 that is average of the thickness of the ferromagnetic workpieces may be used to reduce the need to change pole plates. However, similar to above, if the average thickness of the ferromagnetic workpieces is less than the lower limit (i.e., <2.0 mm), a lower limit (e.g., 2.0 mm) may apply, such that width 564, depth 566, and / or width 568 may be configured to be at the lower limit (i.e., 2.0 mm).

[0106] FIG. 11A is a front view of an exemplary switchable magnetic device 600, and FIG. 11B is a side view of the switchable magnetic device 600. The magnetic device 600 includes pole shoes 602′, 602″ and a housing 604. In an embodiment, the magnetic device 600 may have some or all of the same features and / or functionality as the magnetic device 100, and the pole shoes 602′, 602″ may have some or all of the same features and / or functionality as the pole shoes 102′, 102″. Additionally or alternatively, the pole shoes 602′, 602″ may have some or all of the same features as the pole shoes 200, 300, 400 shown in FIGS. 6, 7, and 8, respectively. For example, the pole shoes 602′, 602″ include a first portion 606 that may be positioned proximate to the housing 604. The pole shoes 602', 602'' also include bores 608 extending therethrough to allow the pole shoes 602', 602'' to be unlatched from the housing 604 via a fastening mechanism (e.g., a fastening screw, etc.). Further, the pole shoes 602', 602" include a plurality of protrusions 610 disposed on a bottom portion 612 of the pole shoes 602', 602". Each of the protrusions 610 is separated by a recessed portion 614. The plurality of protrusions 610 included in the pole shoe 602' collectively form a workpiece contact interface 616' of the pole shoe 602', and the plurality of protrusions included in the pole shoe 602" collectively form a workpiece contact interface 616" of the pole shoe 602".

[0107] Furthermore, by varying the width 618 of the protrusions 622 and / or the depth 620 and / or width 622 of the recesses 614, different shallow magnetic fields will be generated by the same magnetic device 600. In embodiments, to generate an appropriate shallow magnetic field for a particular ferromagnetic material, the width 618 of the protrusions 622 and / or the depth 620 and / or width 622 of the recesses 614 may be approximately the same as the thickness of the ferromagnetic material (e.g., + / - 25%). However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic materials having a thickness below a certain limit. That is, for ferromagnetic materials having a thickness less than X mm, a preferred shallow magnetic field may be generated by a width 618, depth 620, and / or width 622 that is at or above the lower limit of X mm. That is, to generate a preferred magnetic field for a ferromagnetic material having a thickness of ½*X mm, the width 618, depth 620, and / or width 622 may be at the lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic material is X mm or greater, then width 618, depth 620, and / or width 622 can be approximately equal to the thickness of the ferromagnetic material (e.g., + / - 25%). A lower limit example can be in the range of 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0108] Alternatively, when magnetic device 600 is used to couple to ferromagnetic materials having different thicknesses, width 618 of protrusion 622 and / or depth 620 and / or width 622 of recess 614 that is the average of the thickness of the ferromagnetic materials may be used to reduce the need to modify the pole shoe. However, similar to above, if the average thickness of the ferromagnetic materials is less than the lower limit (i.e., <2.0 mm), a lower limit (e.g., 2.0 mm) may apply, such that width 618, depth 620, and / or width 622 may be configured to be at the lower limit (i.e., 2.0 mm).

[0109] The pole shoes 602′, 602″ as shown do not include rounded shoulders (e.g., rounded shoulder 320) and / or curved recesses (e.g., curved recess 310), although in alternative embodiments, the pole shoes 602′, 602″ may include one or both of those features. Additionally or alternatively, the pole shoes 602′, 602″ as shown do not include compressible members (e.g., compressible member 420), although in alternative embodiments, the pole shoes 602′, 602″ may include one or both of those features.

[0110] As shown, the pole shoes 602', 602" have respective thicknesses 624', 624". In embodiments, different thicknesses 624', 624" may generate different shallow and far magnetic fields by the magnetic device 600. That is, thicknesses 624', 624" that are approximately the same as the thickness of the ferromagnetic material to which the magnetic device 600 is coupled, as well as width 618 of protrusion 610, will generate a shallow magnetic field suitable for destack- ing the ferromagnetic material. For example, when the magnetic device 600 destacks a ferromagnetic sheet that is 2 mm thick, thicknesses 624', 624" may be approximately 2 mm (e.g., 2 mm + / - 25%). In embodiments, this generates a strong shallow magnetic field of 0 mm to 2 mm. In embodiments, the pole shoes 602', 602" may be constructed of 304 stainless steel and / or aluminum surrounding at least a portion of the pole shoes 602', 602". may be included to add structural integrity to the pole shoes 602', 602". In an embodiment, this may be particularly advantageous when the pole shoes 602', 602" have a thin thickness 624', 624" (e.g., 5 mm or less).

[0111] Additionally or alternatively, housing 604 may include an offset 626 from workpiece contact interface 616′, 616″. In embodiments, offset 626 may depend on the magnetic field generated by magnetic device 600. That is, in embodiments, offset 626 may be a percentage of the shallow magnetic field depth generated by magnetic device 600. Additionally or alternatively, offset 626 may be a percentage of the thickness of the workpiece. For example, if magnetic device 600 is configured to generate a shallow magnetic field in a workpiece having a depth of X mm and / or is coupled to a workpiece that is X mm thick, offset 626 may be a percentage (greater or less than 100%) of X. In one embodiment, offset 626 may preferably be in the range of 100% to 700% of the shallow magnetic field depth. In another embodiment, offset 626 may preferably be in the range of 200% to 600% of the shallow magnetic field depth. In a further embodiment, the offset 626 may preferably be in the range of 300% to 500% of the shallow magnetic field depth, and in yet another embodiment, the offset 626 may preferably be in the range of 350% to 400% of the shallow magnetic field depth.

[0112] Additionally or alternatively, the pole shoes 602′, 602″ may extend along a direction 628 at distances 630, 632 beyond a front surface 634 and a rear surface 636 of the housing 604, respectively. Stated another way, the width 637 of the pole shoes 602′, 602″ may be greater than a depth 638 of the housing 604. The extension beyond the front and rear surfaces 634, 636 increases the contact area between the workpiece contact interfaces 616′, 616″ and the ferromagnetic material. The increased contact area of ​​the workpiece contact interfaces 616′, 616″ may increase the holding force and / or shear force of the magnetic device 600. In one embodiment, the distance 630, the distance 632, and / or the width 637 may vary depending on the ferromagnetic material to which the magnetic device 600 is coupled. That is, depending on the desired holding force for the ferromagnetic material, the distance 630, the distance 632, and / or the width 637 may be varied to achieve the desired holding force. As another example, distance 630, distance 632, and / or width 637 may be a percentage (greater or less than 100%) of depth 638 of housing 604. In one example, distance 630 and / or distance 632 may preferably be in the range of 25% to 75% of depth 638 of housing 604. In another example, distance 630 and / or distance 632 may preferably be in the range of 35% to 65% of depth 638 of housing 604. In yet another example, distance 630 and / or distance 632 may preferably be in the range of 45% to 55% of depth 638 of housing 604.

[0113] The thickness 640 of the pole shoes 602′, 602″ may also be varied. Similar to increasing the width 637 of the pole shoes 602′, 602″, increasing the thickness 640 of the pole shoes 602′, 602″ increases the contact area between the workpiece contact interface 616′, 616″ and the ferromagnetic material. The increased contact area of ​​the workpiece contact interface 616′, 616″ may increase the coercive force and / or shear force of the magnetic device 600. Thus, the thickness 640 may be varied depending on the desired coercive force of the magnetic device 600. In one embodiment, the thickness 640 may approximately correspond to the thickness of the ferromagnetic material to which the magnetic device 600 is coupled. In another embodiment, the thickness 640 may vary relative to the width 637. That is, depending on the ferromagnetic material to which the magnetic device 600 is coupled, it may be preferable to maintain the surface area of ​​the contact interface 616′, 616″, and therefore the coercive force of the magnetic device 600. Thus, as width 637 increases, thickness 640 can decrease, and vice versa. If the shoe 616', 616'' is preferred for ferromagnetic materials, a preferred retention force can be maintained by decreasing the thickness 640 and increasing the width 637.

[0114] In the embodiments provided above, any of the features of the pole shoes 16, 132, 200, 300, 400, 500, 550, and 602 may be used in conjunction with one another. Additionally or alternatively, any of the protrusions and recesses of the pole shoes 16, 132, 200, 300, 400, 500, 550, and 602 may be integrated into the housing of the magnetic device 10, 100, 600 instead of being coupled to the housing.

[0115] Furthermore, as mentioned above, when the projection width and recess depth / width exceed the lower limit and the projection width and recess depth / width of the pole shoe approximately match the thickness of the ferromagnetic material, a pole shoe having the above characteristics will generate the strongest holding force for a ferromagnetic material having a thickness approximately the same as the projection width and recess depth / width.

[0116] 12 is a flow diagram of a method 700 of using an exemplary switchable magnetic device comprising a pole shoe. The method 700 includes contacting a ferromagnetic material with a first pole shoe, as indicated by block 702. In an embodiment, the first pole shoe may be releasably attached to a housing of the magnetic device. Furthermore, the magnetic device may be capable of establishing two different magnetic circuits. The first magnetic circuit may be referred to as the magnetic device in an on state, and the second magnetic circuit may be referred to as the magnetic device in an off state.

[0117] In embodiments, the first pole shoe, housing, and magnetic device may each have the same or similar features as the pole shoe 16, 102, 200, 300, 400, 500, or 602, housing 28, 104, 604, and magnetic device 10, 100, and 600 described above. For example, the ferromagnetic body may be contacted by the workpiece contact interface of the first pole shoe, which includes multiple protrusions. Additionally or alternatively, the magnetic device may include a first permanent magnet mounted within the housing having an active north-south pole pair and a second permanent magnet having an active north-south pole pair. In embodiments, the second permanent magnet may be rotatably mounted within the housing in a stacked relationship with the first permanent magnet, and the second permanent magnet may be rotatable between a first position and a second position. Additionally or alternatively, the magnetic device may establish multiple magnetic circuits between the magnetic device and the ferromagnetic body, generating different strengths of the magnetic circuit.

[0118] In an embodiment, the method 700 includes contacting a ferromagnetic body with a second pole shoe, as indicated by block 704. In an embodiment, the second pole shoe is mounted to the same housing as the first pole shoe. In an embodiment, the magnetic device may be in the first configuration when the ferromagnetic body is contacted by the second pole shoe.

[0119] In an embodiment, method 700 includes transitioning the magnetic device from an off state to an on state, as indicated by block 706. In an embodiment, transitioning the magnetic device from the off state to the on state may include actuating (e.g., rotating) the second permanent magnet from a first position to a second position. Further, when the magnetic device is in the on state, a magnetic circuit is formed through the workpiece.

[0120] 13, an exemplary robotic system 700 is illustrated. Although robotic system 700 is illustrated in FIG. 13, the embodiments described therein may be applied to other types of machines (e.g., crane hoists, pick-and-place machines, etc.). do.

[0121] The robotic system 700 includes an electronic controller 770. The electronic controller 770 includes additional logic stored in an associated memory 774 for execution by a processor 772. A robot movement module 702 is included that controls movement of a robotic arm 704. In the illustrated embodiment, the robotic arm 704 includes a first arm segment 706 that is rotatable relative to a base about a vertical axis. The first arm segment 706 is movably coupled to a second arm segment 708 through a first joint 710, such that the second arm segment 708 can be rotated relative to the first arm segment 706 in a first direction. The second arm segment 708 is movably coupled to a third arm segment 711 through a second joint 712, such that the third arm segment 711 can be rotated relative to the second arm segment 708 in a second direction. The third arm segment 711 is movably coupled to the fourth arm segment 714 through a third joint 716, such that the fourth arm segment 714 can be rotated relative to the third arm segment 711 in a third direction, and the orientation of the fourth arm segment 714 relative to the third arm segment 711 can be changed by a revolute joint 718. A magnetic coupling device 10 is illustratively shown fixed to the end of the robot arm 704. The magnetic coupling device 10 is used to couple a workpiece 27 (not shown) to the robot arm 704. Although a magnetic coupling device 10 is illustrated, any of the magnetic coupling devices described herein, and any number of the magnetic coupling devices described herein, can be used in the robot system 700.

[0122] In one embodiment, the electronic controller 770, with the processor 772 executing the robot transfer module 702, moves the robot arm 704 to a first pose, where the magnetic coupling device 100 contacts the workpiece at a first location. The electronic controller 770, with the processor 772 executing the magnetic coupling state module 776, commands the magnetic device 10 to move the upper magnet 12 relative to the lower magnet 14 and place the magnetic coupling device 10 in an ON state to couple the workpiece to the robot system 700. The electronic controller 770, with the processor 772 executing the robot transfer module 702, moves the workpiece from the first location to a second desired spaced apart location. Once the workpiece is in the desired second position, the electronic controller 770, with the processor 772 executing the magnetic coupling state module 776, commands the magnetic device 10 to move the upper magnet 12 relative to the lower magnet 14 and place the magnetic coupling device 10 in an OFF state to decouple the workpiece from the robot system 700. The electronic controller 770 then repeats the process of coupling, moving, and decoupling another workpiece.

[0123] In one embodiment, the disclosed magnetic device includes one or more sensors for determining characteristics of a magnetic circuit that exists between the magnetic device and a workpiece coupled to the magnetic device. Further details of an exemplary sensor system are provided in U.S. Provisional Patent Application No. 62 / 490,705, filed April 27, 2017, entitled "SMART SENSE EOAMT," the entire disclosure of which is expressly incorporated herein by reference.

[0124] As mentioned above, other configurations of magnets may be used in place of permanent magnets 12, 14 or permanent magnets 130, 132. Referring to Figures 14 and 15, a side cross-sectional view of an exemplary magnetic coupling device 800 of the present disclosure is shown. Magnetic coupling device 800 includes an upper assembly 802 and a lower assembly 804. Each of assemblies 802 and 804 includes a plurality of spaced apart permanent magnets 806 and a plurality of pole pieces 808. Each of the plurality of spaced apart permanent magnets 806 is illustratively shown as one permanent magnet, but may comprise multiple permanent magnets and / or at least one permanent magnet positioned within a housing.

[0125] Each permanent magnet 806 has a north-pole side (N) and a south-pole side (S). The permanent magnets 806 and pole portions 808 of the upper assembly 802 and the lower assembly 804 are each arranged in a linear array, with one of the pole portions 808 positioned between two permanent magnets 806. Furthermore, the permanent magnets 806 are arranged such that two permanent magnets 806 in contact with a pole portion 808 between them each have either their north-pole side (N) or their south-pole side (S) in contact with the pole portion 808. When the north-pole side (N) of an adjacent permanent magnet 806 contacts a pole portion 808, the pole portion 808 is referred to as a north-pole portion. When the south-pole side (S) of an adjacent permanent magnet 806 contacts a pole portion 808, the pole portion 808 is referred to as a south-pole portion.

[0126] In an embodiment, lower assembly 804 replaces permanent magnet 14 of magnetic coupling device 10 or permanent magnet 130 of magnetic coupling device 100 and is held fixed relative to housing 28, and upper assembly 802 replaces permanent magnet 12 of magnetic coupling device 10 or permanent magnet 132 of magnetic coupling device 100. Upper assembly 802 is translatable relative to lower assembly 804 in directions 810 and 812 to change the alignment of permanent magnets 806 and pole pieces 808 of upper assembly 802 with respect to permanent magnets 806 and pole pieces 808 of lower assembly 804. Permanent magnets 806 of lower assembly 804 are spaced from workpiece 27′ by pole pieces 814 of magnetic coupling device 800. Additionally, spacers (not shown) are provided between the permanent magnets of upper assembly 802 and lower assembly 804.

[0127] When the south-pole portion 808 of the lower assembly 804 is aligned with the south-pole portion 808 of the upper assembly 802 and the north-pole portion 808 of the lower assembly 804 is aligned with the north-pole portion 808 of the upper assembly 802 (see FIG. 14 ), the magnetic coupling device 800 is in an on state. In the on state, the workpiece 27′ is held by the magnetic coupling device 800 by completing a magnetic circuit, as illustrated by magnetic flux lines 816, from the aligned north-pole portions 808 of the upper and lower assemblies 802, 804, through the workpiece 27′ to the aligned south-pole portions 808 of the upper and lower assemblies 804. The size and shape of the pole portions 814 cause the first magnetic circuit to substantially rest on the workpiece sheet 27′ of the workpiece sheet 27, providing sufficient holding force to vertically lift the workpiece sheet 27′ in direction 818 relative to the rest of the workpiece sheet 27. Thus, the magnetic coupling device 800 may function to destack the workpiece sheet 27. In some embodiments, a portion of the magnetic flux provided to the workpiece sheet 27 by the magnetic coupling device 800 may enter the lower sheet 27'' of the workpiece sheet 27, but not to a level at which the lower sheet 27'' would be lifted together with the workpiece sheet 27' by the magnetic coupling device 800. Thus, as used herein, a first magnetic circuit that substantially remains at the workpiece sheet 27' of the workpiece sheet 27 means that the amount of magnetic flux from the switchable magnetic lifting device 800 that enters the lower sheet 27'' is below a level at which the lower sheet 27'' would be lifted together with the workpiece sheet 27' vertically in the direction 818 by the magnetic coupling device 800.

[0128] When the south-pole portion 808 of the lower assembly 804 is aligned with the north-pole portion 808 of the upper assembly 802 and the north-pole portion 808 of the lower assembly 804 is aligned with the south-pole portion 808 of the upper assembly 802 (see FIG. 15 ), the magnetic coupling device 800 is in an off state. In the off state, the workpiece 27′ is not held by the magnetic coupling device 800 by completing a magnetic circuit within the upper assembly 802 and the lower assembly 804 from the aligned north-pole portion 808 of the upper assembly 802 to the south-pole portion 808 of the lower assembly 804, and from the aligned north-pole portion of the upper assembly 802 to the south-pole portion 808 of the lower assembly 804.

[0129] In an embodiment, the pole portions 808 may also have the same or similar characteristics as the pole shoes 102, 200, 300, 400, 500, 602 (e.g., the same or similar width, recess width and / or depth, rounded shoulder portions, curved workpiece interface, compressible members between each of the pole portions 808, etc.).

[0130] 16-18, another exemplary magnetic assembly 900 of the present disclosure is shown. The magnetic assembly 900 includes an upper platter 912 and a lower platter 914. Each of the platters 912 and 914 includes a plurality of spaced-apart permanent magnets 930 and a plurality of pole pieces 950. While illustratively shown as a single permanent magnet, each of the plurality of spaced-apart permanent magnets 930 may comprise multiple permanent magnets and / or at least one permanent magnet positioned within a housing. Exemplary platters are provided in U.S. Patent No. 7,161,451 and U.S. Provisional Patent Application No. 62 / 248,804, filed October 30, 2015, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," Attorney Docket No. MTI-0007-01-US-E.

[0131] Returning to the example of Figures 16-18, each permanent magnet 930 has an N-pole side 932 and a S-pole side 934. The permanent magnets 930 and pole portions 950 of platters 912 and 914 are each arranged to form a closed shape, with one of the pole portions 950 positioned between two permanent magnets 930. Furthermore, the permanent magnets 930 are arranged such that each of the two permanent magnets 930 that contact a pole portion 950 between them has either their N-pole side or their S-pole side in contact with the pole portion 950. When the N-pole side of an adjacent permanent magnet 930 contacts a pole portion 950, the pole portion 950 is referred to as an N-pole portion. When the S-pole side of an adjacent permanent magnet 930 contacts a pole portion 950, the pole portion 950 is referred to as a S-pole portion.

[0132] Each of the upper and lower platters 912, 914 includes an equal, even number of permanent magnet sections and an equal number of pole pieces 950. In one embodiment, on each of the upper and lower platters 912, 914, the permanent magnets 930 and pole pieces 950 are arranged in a circular configuration.

[0133] In an embodiment, lower platter 914 replaces permanent magnet 14 of magnetic coupling device 10 or permanent magnet 130 of magnetic coupling device 100 and is held fixed relative to housing 28, and upper platter 912 replaces permanent magnet 12 of magnetic coupling device 10 or permanent magnet 132 of magnetic coupling device 100 and rotates relative to lower platter 914. Additionally or alternatively, the lower platter may be incorporated into magnetic coupling device 1000, described below in connection with FIGS.

[0134] The upper platter 912 is rotatable relative to the lower platter 914 in directions 990 , 992 about a central axis 994 to change the alignment of the permanent magnets 930 and pole pieces 950 of the upper platter 912 relative to the permanent magnets 930 and pole pieces 950 of the lower platter 914 .

[0135] The magnetic coupling device 900 is in an ON state when the south-pole portion 950 of the lower platter 914 is aligned with the south-pole portion 950 of the upper platter 912 and the north-pole portion 950 of the lower platter 914 is aligned with the north-pole portion 950 of the upper platter 912. In the ON state, the workpiece 27 is held by the magnetic coupling device 10 by completing a magnetic circuit from the aligned north-pole portions 950 of the upper and lower platters 912, 914, through the workpiece 27, to the aligned south-pole portions 950 of the upper platters 912 and 914.

[0136] The magnetic coupling device 10 is in the off state when the south-pole portion 950 of the lower platter 914 is aligned with the north-pole portion 950 of the upper platter 912 and the north-pole portion 950 of the lower platter 914 is aligned with the south-pole portion 950 of the upper platter 912. In the off state, the workpiece 27 is not held by the magnetic coupling device 10 by completing a magnetic circuit within the upper platter 912 and lower platter 914 from the aligned north-pole portion 950 of the upper platter 912 to the south-pole portion 950 of the lower platter 914, and from the aligned north-pole portion of the upper platter 912 to the south-pole portion 950 of the lower platter 914.

[0137] 16, the upper platter 912 is shown exploded relative to the lower platter 914. The lower platter 914 is generally identical to the upper platter 912. The upper platter 912 can be rotated relative to the lower platter 914 to place the magnetic coupling device 10 in an on or off state.

[0138] 17, an upper platter 912 is illustrated. The upper platter 912 includes a cylindrical base component 920 having a central opening 922 and a plurality of radially extending openings 924. Each of the radially extending openings 924 is sized and shaped to receive a permanent magnet 930. Each permanent magnet 930 has a north side 932, a south side 934, a radially inward-facing side 936, a radially outward-facing side 938, a top 940, and a bottom.

[0139] 18 , a top view of the upper platter 912 is shown. A cylindrical base component 920 surrounds each of the north side 932, south side 934, radially inward-facing side 936, and radially outward-facing side 938 of the permanent magnet 930. In one embodiment, the openings 924 are not through openings but rather are depth openings not visible from the bottom side of the cylindrical base component 920, so that the cylindrical base component 920 also surrounds the tops 940 of the pole pieces 950. In the illustrated embodiment, the cylindrical base component 920 is one unitary component. In one embodiment, the cylindrical base component 920 is made up of two or more components joined together.

[0140] 18 , the permanent magnets 930 are arranged such that the north sides 932 of adjacent magnets face each other and the south sides 934 of adjacent magnets 930 face each other. This arrangement results in portions 950 of the cylindrical base component 920 between the permanent magnets 930 acting as pole extensions for the permanent magnets 930. In an embodiment, the base component 920, and therefore the pole portions 950, are made of steel. Other suitable ferromagnetic materials may be used for the base component 920.

[0141] 19-22, another exemplary magnetic coupling device 1000 of the present disclosure is shown. In FIG. 19, an exploded view of the magnetic coupling device 1000 is shown. The magnetic coupling device 1000 includes the magnetic assembly 900 shown in FIGS. 16-18 with the addition of a spacer 1002 disposed between the permanent magnets of the upper platter 912 and the lower platter 914. The magnetic coupling device 1000 illustratively includes a non-ferromagnetic housing 1004 having a circular footprint. A circular bore 1006 extends axially from the bottom to the top of the housing 1004. The upper platter 912 and the lower platter 914 are received in the bore 1006.

[0142] The exemplary magnetic coupling device 1000 includes an actuator assembly 1008 for facilitating rotation of the upper platter 912 relative to the lower platter 914. In the illustrated embodiment, the actuator assembly 1008 rotates from a central bore 1012 in the cylindrical base component 920 of the upper platter 912 to a rotary actuator of the actuator assembly 1008. The rotary actuator 1016 includes a shaft 1010 that protrudes into a central bore 1014 of the actuator 1016. The rotary actuator 1016 is coupled to the cylindrical base component 920 by a pin 1018. Thus, when the rotary actuator 1016 is rotated, the rotation of the rotary actuator 1016 is translated into the cylindrical base component 920 by the pin 1018, resulting in rotation of the upper platter 912 relative to the lower platter 914. The shaft 1010 facilitates concentric rotation of the rotary actuator 1016 and the second platter 912 about the central axis 1020.

[0143] The actuator assembly 1008 may include a ring 1022 that facilitates concentric rotation of the rotary actuator 1016 about a central axis 1020. The ring 1022 fits within a cap component 1024. The ring 1022 may form a clearance fit with the inner surface of the cap component 1024 to facilitate rotation of the ring 1022 within the cap component 1024. The ring 1022 also includes a central bore 1026 that fits over a portion 1028 of the rotary actuator 1016. The ring 1022 may be coupled to the rotary actuator 1016 via a pin 1030. Alternatively, the ring 1022 may be free to rotate relative to the rotary actuator 1016.

[0144] Rotation of the rotary actuator 1016 may be achieved by inserting a torque output shaft (not shown) into and through a central bore 1031 of the cap component 1024 and being received by the central bore 1014 of the rotary actuator 1016. The end of the torque output shaft engages an internal ridge (not shown) of the central bore 1014 such that concentric rotation of the torque output shaft translates to concentric rotation of the rotary actuator 1016. As described above, the rotary actuator 1016 is coupled to the base component 920 by a pin 1018. Thus, when the rotary actuator 1016 is rotated by the torque output shaft, rotation of the rotary actuator 1016 translates to rotation of the upper platter 920.

[0145] As shown in FIGS. 20-22 , the base component 920 is separated into multiple sectors 1034 by non-ferromagnetic pieces 1036. Each sector 1034 of the workpiece contact interface 1040 includes spaced apart projections 1038 separated by recesses 1039 (see FIG. 22 ). As shown, the spaced apart projections 1038 are located within a vertical envelope 1041 defined by the central bore 1006. The spaced apart projections 1038 may be integrally formed as a bottom surface of the pole portion 950 of the base component 920. Alternatively, the spaced apart projections 1038 may be coupled to the bottom surface of the pole portion 950. While the illustrated example shows four spaced apart projections 1038, other embodiments may have two or more spaced apart projections 1038.

[0146] The spaced apart projections 1038 collectively form a workpiece contact interface 1040. That is, in an embodiment, the spaced apart projections 1038 form the workpiece contact interface 1040 of the pole portion 950 of the base component 920. Accordingly, the spaced apart projections 1038 may also be referred to herein as the pole portion-workpiece interface 1038. In an embodiment, the central projection 1042 and / or the non-ferromagnetic piece 1036 may be included in the workpiece contact interface 1040.

[0147] The pole piece workpiece interface 1038 is located at a different radial distance 1044 from the central protrusion 1042 of the base component 920. In an embodiment, the radial distance 1044 may be a multiple of the thickness of the workpiece sheet 27. As an example, if the thickness of the workpiece sheet 27 is X mm, the radial distance 1044 may be n*X (+ / - 25%), where n is an integer. The pole piece workpiece interface 1038 may also be located at the same or similar distance as the pole shoe 102, 200, 300, 400, 500, 602. They may have characteristics (e.g., the same or similar width, recess width and / or depth, rounded shoulders, curved workpiece interfaces, compressible members between each of the pole-workpiece interfaces 1038, etc.).

[0148] Because the pole piece workpiece interfaces 1038 are spaced apart, they may have many of the same advantages as the pole shoes 16', 16" described above. That is, they may generate a shallow magnetic field useful for destacking the workpiece sheet 27. For example, when the magnetic coupling device 1000 is in an on state, the magnetic circuit generated by the magnetic coupling device 1000 substantially rests on the workpiece sheet 27' of the workpiece sheet 27 and is of sufficient holding force to vertically lift the workpiece sheet 27' in the direction 1046 (of FIG. 22) relative to the rest of the workpiece sheet 27. Thus, the magnetic coupling device 1000 may function to destack the workpiece sheet 27. Of course, in some embodiments, a portion of the magnetic flux provided to the workpiece sheet 27 by the switchable magnet device 10 may enter the lower sheet 27" of the workpiece sheet 27, but not to a level that would result in the lower sheet 27" being lifted along with the workpiece sheet 27' by the switchable magnetic device 1000. Thus, as used herein, a first magnetic circuit that substantially remains in workpiece sheet 27' of workpiece sheet 27 means that the amount of magnetic flux from switchable magnetic lifting device 1000 that enters lower sheet 27'' is below the level at which lower sheet 27'' would be vertically lifted in direction 1046 together with workpiece sheet 27' by switchable magnetic lifting device 1000.

[0149] 23-27 , another exemplary magnetic coupling device 1100 of the present disclosure is shown. The magnetic coupling device 1100 includes a lower platter 14. Alternatively, the lower permanent magnet 14 may be replaced with an upper permanent magnet 12, an upper magnet 118, a lower magnet 120, an upper platter 912, a lower platter 914, or a bar magnet. Additionally or alternatively, instead of being cylindrical and / or having a circular footprint, the magnetic coupling 1100 may be a parallelepiped and / or have a rectangular footprint.

[0150] The housing 1102 of the magnetic coupling device 1100 houses the lower permanent magnet 14 and an actuator assembly 1104. The actuator assembly 1104 facilitates movement of the lower permanent magnet 14 along an axis 1106. Specifically, in the illustrated embodiment, the actuator assembly 1104 includes a connecting rod 1108 that couples the lower permanent magnet 14 to the crown 1110. That is, the connecting rod 1108 extends from the lower permanent magnet 14 through a central bore 1112 of the intermediate element 1114 to the crown 1110. In one example, the connecting rod 1108 and the central bore 1112 form a clearance fit. The crown 1110 and the inner wall of the housing 1102 may also form a clearance fit. In at least some embodiments, the intermediate element 1114 acts as a shorting plate, such that the magnetic circuit generated by the magnet 14 is primarily contained within the housing 1102.

[0151] In the exemplary embodiment shown, the housing 1102 includes two ports 1118. Gas and / or fluid may be provided through the ports 1118 to move the actuator assembly 1104 from a first position shown in FIG. 23 to a second position shown in FIG. 24, and vice versa. Specifically, by providing gas and / or fluid through port 1118A to a housing portion 1120 above the crown 1110, the gas and / or fluid exerts pressure on an upper surface 1122 of the crown 1110, thereby exerting a downward force on the actuator assembly 1104. In response, the actuator assembly 1104 moves downward along the axis 1106 such that the lower permanent magnet 14 is positioned near the base 1127 of the housing 1102. As will be discussed in more detail, when the permanent magnet 14 is positioned near the base 1127 of the housing 1102, a magnetic circuit is formed substantially through the workpiece 27' (see FIG. 23), thereby enabling the workpiece sheet 27' to be destacked from the workpiece sheets 27'', 27'''.

[0152] Alternatively, by providing gas and / or fluid to the housing portion 1124 below the crown 1110 through the port 1118B, the gas and / or fluid exerts pressure on the bottom surface 1126 of the crown 1110, thereby providing an upward force on the actuator assembly 1104. In response, the actuator assembly moves upward along the axis 1106 such that the lower permanent magnet 14 is positioned spaced apart and / or separate from the base 1127 of the housing 1102. When the lower permanent magnet 14 is positioned spaced apart and / or separate from the base 1127 of the housing 1102, the magnetic circuit is substantially inside the housing 1102 (see FIG. 24 ), thereby allowing the magnetic coupling device 1110 to be separated from the workpiece sheet 27.

[0153] Although the illustrated example shows intermediate element 1112, in alternative embodiments, magnetic coupling device 1100 may not include intermediate element 1114. However, in these embodiments, more gas and / or liquid may need to be provided within housing portion 1124 such that actuator assembly 1104 will move upwardly and away from base 1127 of housing 1102.

[0154] In an alternative embodiment, the actuator assembly 1104 may be moved along the axis 1106 using a linear actuator 1128 coupled to an engagement portion 1130 coupled to the actuator assembly 1104. The actuator 1128 and / or the device providing the gas and / or liquid through the port 1118 may be coupled to a controller (e.g., controller 34) that controls the operation and thus the position of the actuator assembly 1104. Alternatively, the linear actuator 1128 may be electrically and / or manually actuated.

[0155] As shown in FIG. 25, the housing 1102 may have a circular base 1132. Referring to the illustrated embodiment shown in FIG. 25, the base 1132A may be separated into two sectors 1134 by a non-ferromagnetic piece 1136 so that there is a sufficient gap between the north and south poles to prevent shorting of the magnetic circuit. Each sector 1134 of the base 1132A includes spaced apart protrusions 1138 separated by recesses 1139 (see FIG. 24). As shown, the spaced apart protrusions 1138 are located within the vertical envelope 1141 of the housing 1102. The spaced apart protrusions 1138 may be coupled to the base 1127 of the housing 1102. The base 1132A may include two or more spaced apart protrusions 1138.

[0156] The spaced apart projections 1138 collectively form a workpiece contact interface 1140 (see FIG. 24 ) of the base 1132A. Accordingly, the spaced apart projections 1138 may also be referred to herein as pole-workpiece interfaces 1138. The central projection 1142 and / or the non-ferromagnetic piece 1136 may be included in the workpiece contact interface 1140 of the base 1132A.

[0157] The pole workpiece interfaces 1138 are located at different radial distances 1144 from the central projection 1140. In an embodiment, the radial distances 1144 may be multiples of the thickness of the workpiece sheet 27. As an example, if the thickness of the workpiece sheet 27 is X mm, the radial distance 1144 may be n*X (+ / - 25%), where n is an integer. The pole workpiece interfaces 1138 are also located at different radial distances 1144 from the pole shoes 102, 2 00, 300, 400, 500, 602 may have the same or similar characteristics (e.g., the same or similar width, recess width and / or depth, rounded shoulders, curved workpiece interfaces, compressible members between each of the pole piece workpiece interfaces 1138, etc.) as 00, 300, 400, 500, 602. While the pole piece workpiece interfaces 1138 are shown as being circular, they may alternatively be linear.

[0158] Because the pole portion workpiece interfaces 1138 are spaced apart, they may have many of the same advantages as the pole shoes 16′, 16″ and / or pole portion workpiece interfaces 1038 described above. That is, they may generate a shallow magnetic field useful for destacking the workpiece sheet 27. For example, when the magnetic coupling device 1100 is in the on state (see FIG. 23 ), the magnetic circuit generated by the magnetic coupling device 1100 substantially rests on the workpiece sheet 27′ of the workpiece sheet 27, and is a holding force sufficient to vertically lift the workpiece sheet 27′ in the direction 1146 (of FIG. 23 ) relative to the rest of the workpiece sheet 27. Thus, the magnetic coupling device 1100 may function to destacking the workpiece sheet 27. In some embodiments, a portion of the magnetic flux provided to the workpiece sheet 27 by the switchable magnetic device 10 may enter the lower sheet 27'' of the workpiece sheet 27, but not to a level at which the lower sheet 27'' would be lifted together with the workpiece sheet 27' by the switchable magnetic device 10. Thus, as used herein, a first magnetic circuit that substantially remains at the workpiece sheet 27' of the workpiece sheet 27 means that the amount of magnetic flux from the switchable magnetic lifting device 1100 that enters the lower sheet 27'' is below a level at which the lower sheet 27'' would be lifted together with the workpiece sheet 27' vertically in the direction 1146 by the switchable magnetic lifting device 1100.

[0159] As mentioned above, the lower permanent magnet 14 may be replaced by the upper permanent magnet 12, the upper magnet 118, the lower magnet 120, the upper platter 912, or the lower platter 914. In embodiments in which the lower permanent magnet 14 is replaced by the upper platter 912 or the lower platter 914, the base 1132A may be replaced by the base shown in FIG.

[0160] In yet other embodiments, as shown in Figures 26 and 27, the pole-workpiece interface 1138 of the magnetic coupling device 1100 may be replaced by a pole shoe 16', 16" In embodiments, the pole shoe 16', 16" may also have the same or similar characteristics as the pole shoes 102, 200, 300, 400, 500, 602 (e.g., the same or similar width, recess width and / or depth, rounded shoulder portions, curved workpiece interface, compressible members between each of the spaced apart projections, etc.).

[0161] Another exemplary magnetic coupling device 1200 of the present disclosure is shown in Figures 28A-30. Figure 28A shows a cross-sectional side view of the exemplary switchable magnetic coupling device 1200 in a first, OFF state, and Figure 28B shows a cross-sectional front view of the magnetic coupling device 1200. Figure 29 shows a cross-sectional front view of the magnetic coupling device of Figures 28A-28B in a second, ON state. Figure 30 shows a cross-sectional front view of the magnetic coupling device of Figures 28A-28B in a third, ON state.

[0162] The magnetic coupling device 1200 can be switched between a first OFF state (shown in FIGS. 28A-28B), a second ON state (shown in FIG. 29), and / or a third ON state. When the magnetic coupling device 1200 is switched to the ON state, the magnetic field generated by the magnetic coupling device 1200 passes through one or more ferromagnetic workpieces 1202, coupling the magnetic coupling device 1200 to one or more of the ferromagnetic workpieces 1202. When the magnetic coupling device 1200 is switched to the OFF state, the magnetic coupling device 1200 The magnetic field generated by the magnetic coupling device 1200 remains primarily within the magnetic coupling device 1200, and therefore the magnetic coupling device 1200 is no longer coupled to one or more of the ferromagnetic workpieces 1202. The off and on states are discussed in more detail below.

[0163] Magnetic coupling device 1200 may be used as an end of arm ("EOAMT") unit for a robotic system such as robotic system 700 (see FIG. 13), but may also be used in other lifting, transporting, and / or separation systems for ferromagnetic workpieces 1202. Exemplary lifting and transporting systems include robotic systems, mechanical gantries, crane hoists, and additional systems that lift and / or transport ferromagnetic workpieces 1202. Additionally, magnetic coupling device 1200 may be used as part of a fixture to hold at least a portion for operations such as welding, inspection, and other operations.

[0164] 28A , the magnetic coupling device 1200 is positioned on top of the ferromagnetic workpiece 1202 and includes a workpiece contact interface 1204 configured to contact and engage with the ferromagnetic workpiece 1202. The workpiece contact interface 1204 may be a pole plate 1206. In at least one embodiment, the pole plate 1206 includes a plurality of spaced apart protrusions 1208, as illustrated in FIG. 28B . In other embodiments, the pole plate 1206 does not include the spaced apart protrusions 1208. The spaced apart protrusions 1208 may facilitate concentrating more magnetic flux near the workpiece contact interface 1204 such that the magnetic flux of the magnetic coupling device 1200 passes primarily through the first ferromagnetic workpiece 1202′ when the magnetic coupling device 1200 is in an on state. Exemplary aspects of the pole plate 1206 and the protrusions 1208 are discussed below.

[0165] The magnetic coupling device 1200 also includes a housing 1210 that supports a magnetic platter 1212. The magnetic platter 1212 generates a magnetic field that allows the magnetic coupling device 1200 to couple to the ferromagnetic workpiece 1202 when the magnetic coupling device 1200 is in an on state. In at least one embodiment, the magnetic platter 1212 is a laminated magnetic platter that includes a plurality of spaced-apart permanent magnet portions 1214 and a plurality of pole portions 1216, as shown in FIG. 28B . Each of the plurality of spaced-apart permanent magnet portions 1214 includes one or more permanent magnets. In one embodiment, each permanent magnet portion 1214 includes one permanent magnet. In another embodiment, each permanent magnet portion 1214 includes multiple permanent magnets. Each permanent magnet portion 1214 is oppositely magnetized, having a north-pole side and a south-pole side.

[0166] Each pole portion 1216A is positioned between two permanent magnet portions 1214, and a pole portion 1216B is positioned adjacent to one permanent magnet portion 1214. Furthermore, the permanent magnet portions 1214 are arranged such that each of the two permanent magnet portions 1214 that contact a pole portion 1216A between them has either its north pole side or its south pole side in contact with the pole portion 1216A. When the north pole side of an adjacent permanent magnet portion 1214 contacts the pole portion 1216A, the pole portion 1216A is referred to as the north pole portion. When the south pole side of an adjacent permanent magnet portion 1214 contacts the pole portion 1216A, the pole portion 1216A is referred to as the south pole portion. Similarly, when the south pole side of the permanent magnet portion 1214 contacts the pole portion 1216B, the pole portion 1216B is referred to as the south pole portion. Conversely, when the north-pole side of the permanent magnet portion 1214 contacts the pole portion 1216B, the pole portion 1216B is referred to as the north-pole portion.

[0167] In the embodiment shown, the permanent magnet portions 1214 are arranged along a horizontal axis 1218. However, in other embodiments, the permanent magnet portions 1214 may be arranged in a circular configuration. Additionally, while the embodiment shows a magnetic platter 1212 including six permanent magnet portions 1214 and seven pole portions 1216, other embodiments may include more or fewer. The magnetic platter 1212 may include one permanent magnet portion 1214 and two pole portions 1216, one on each side of the permanent magnet portion 1214. For example, in one embodiment, the magnetic platter 1212 may include one permanent magnet portion 1214 and two pole portions 1216, one on each side of the permanent magnet portion 1214.

[0168] Due to the configuration of the magnetic platter 1212 and the magnetic coupling device 1200, the magnetic coupling device 1200 may have a greater magnetic flux transfer to one or more of the ferromagnetic pieces 1202 than conventional embodiments. This may result in the magnetic coupling device 1200 being able to lift more and / or heavier ferromagnetic workpieces 1202 per magnetic volume contained within the magnetic coupling device 1200. For example, the magnetic coupling device 1200 may have a holding force of 0.35 grams or more of the ferromagnetic workpiece 1202 per cubic millimeter of volume of the magnetic coupling device 1200. As another example, the magnetic coupling device 1200 may have a holding force of 0.8 grams or more of the ferromagnetic workpiece 1202 per cubic millimeter of volume of the housing 1210 of the magnetic coupling device 1200.

[0169] To switch the magnetic coupling device 1200 between a first OFF state and a second ON state, the magnetic platter 1212 is linearly translatable along an axis 1220 within the interior cavity 1222 of the housing 1204. In embodiments, the axis 1220 is a vertical axis 1220. Alternatively, the axis 1220 is an axis other than a vertical axis. The axis 1220 extends between a first end 1224 of the housing 1204 and a second end 1226 of the housing 1210. In at least some embodiments, the first end 1224 is an upper portion of the housing 1210, and the second end 1226 is a lower portion of the housing 1210, and may be referred to as such herein. However, in at least some other embodiments, the first end 1224 is a portion of the housing 1210 other than an upper portion of the housing 1210, and the second end 1226 is a portion of the housing 1210 other than a lower portion of the housing 1210. When the magnetic platter 1212 is positioned near the upper portion 1224 of the housing 1210, the magnetic coupling device 1200 is in a first off state. When the magnetic platter 1212 is positioned near the lower portion 1226 of the housing 1210, the magnetic coupling device 1200 is in a second on state. In addition to the first off state and the second on state, the magnetic platter 1212 may be positioned in one or more intermediate positions between the upper portion 1224 and the lower portion 1226, as shown in FIG. 30 . The intermediate positions may be referred to herein as a third on state. As discussed below, the third ON state may generate less magnetic flux at the workpiece contact interface 1204 than the second ON state.

[0170] To translate the magnetic platter 1212 along the vertical axis 1220 and transition the magnetic coupling device 1200 between an ON state and an OFF state, and vice versa, the magnetic coupling device 1200 includes an actuator 1228. In at least one embodiment, the actuator 1228 is coupled to the magnetic platter 1212 via an engagement portion 1230 and a non-ferromagnetic mounting plate 1232. That is, the actuator 1228 is coupled to the engagement portion 1230, which is coupled to the non-ferromagnetic mounting plate 1232, which is coupled to and in contact with the magnetic platter 1212. The actuator 1228 is configured to exert a force on the engagement portion 1230, which in response translates along the vertical axis 1220 and transitions the magnetic coupling device 1200 from the OFF state to the ON state, and vice versa. That is, to transition magnetic coupling device 1200 from an OFF state to an ON state, actuator 1228 exerts a downward force on engagement portion 1230, which translates non-ferromagnetic mounting plate 1232 and magnetic platter 1212. In response, magnetic platter 1212 translates from upper portion 1224 to lower portion 1226. Conversely, to transition magnetic coupling device 1200 from an ON state to an OFF state, actuator 1228 exerts an upward force on engagement portion 1230, which translates non-ferromagnetic mounting plate 1232 and magnetic platter 1212. In response, magnetic platter 1212 translates from upper portion 1224 to lower portion 1226. 2 and non-ferromagnetic mounting plate 1232 translate from lower portion 1226 to upper portion 1224.

[0171] To place the magnetic platter 1212 in the third ON state, the actuator 1228 may generate a force on the engagement portion 1230 to translate the magnetic platter 1212 from the upper portion 1224 to the lower portion 1226, or vice versa. Then, as the magnetic platter 1212 is translating from the upper portion 1224 to the lower portion 1226, or vice versa, a brake 1234 disposed in the housing 1210 and / or in the actuator 1228 engages the magnetic platter 1212, the non-ferromagnetic mounting plate 1232, and / or the engagement portion 1230, as shown in FIG. 30 , to stop the magnetic platter 1212 in the third ON state.

[0172] Exemplary actuators 1228 include electric actuators, pneumatic actuators, hydraulic actuators, and other suitable devices that impart force on engagement portion 1230. An exemplary pneumatic linear actuator is shown in and discussed in more detail in connection with FIG. 31. An exemplary electric actuator is an electric motor with an “unroll” stator and rotor coupled to engagement portion 1230. Other exemplary engagement portions and actuators are described in U.S. Patent No. 7,012,495, entitled "SWITCHABLE PERMANENT MAGNETIC DEVICE," U.S. Patent No. 7,161,451, entitled "MODULAR PERMANENT MAGNET CHUCK," U.S. Patent No. 8,878,639, entitled "MAGNET ARRAYS," U.S. Provisional Patent Application No. 62 / 248,804, filed October 30, 2015, Docket No. MTI-0007-01-US-E, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," and ... LINEAR ACTUATION No. 62 / 252,435, filed November 7, 2015, entitled "A METHOD AND APPARATUS FOR TRANSMITTING AN INTERFACE TO A SUBJECT MATTER" and Docket No. MTI-0006-01-US-E, the entire disclosure of which is expressly incorporated herein by reference.

[0173] Additionally or alternatively, actuator 1228 may include controller 1236 and / or sensor 1238A. Controller 1236 includes processor 1240 along with associated computer-readable media, illustratively memory 1242. Memory 1242 includes control logic 1244 that, when executed by processor 1240, causes electronic controller 1236 to instruct actuator 1228 to move magnetic platter 1212 so that magnetic device 1200 is in an off state, a second on state, and / or a third on state. For example, sensor 1238A may sense the position of actuator 1228, and in response to a predetermined position sensed by sensor 1238A translating to the position of magnetic platter 1212, control logic 1244 instructs actuator 1228 to stop exerting force on magnetic platter 1212 when magnetic platter 1212 reaches the desired position.

[0174] In at least one embodiment, the actuator 1228 is a stepper motor, and the rotational motion of the actuator 1228 is converted to linear motion of the engagement portion 1230 via a coupling (e.g., gears) between the shaft of the actuator 1228 and the engagement portion 1230. In these embodiments, the sensor 1238A counts pulses used to drive the stepper motor and, based on the number of pulses, determines the position of the shaft of the stepper motor, which is converted to the position of the magnetic platter 1212. The position, or angle, of the shaft is then converted to the height of the gap 1250. That is, the magnetic platter 1212 is moved relatively along the vertical axis 1220 to a defined position by the steps the motor moves by counting the number of pulses. In another embodiment, In an embodiment, a stepper motor is provided that integrates an encoder with the stepper to ensure that the proper actuation angle is maintained.

[0175] As another example, magnetic coupling device 1200 may include sensor 1238B. Sensor 1238B may measure the position of magnetic platter 1212 within housing 1210. An exemplary sensor 1238B includes an optical sensor that monitors a reflective strip attached to magnetic platter 1212. Other sensor systems may be used to determine the position of magnetic platter 1212.

[0176] As yet another example, the magnetic coupling device 1200 may include one or more sensors 1238C (illustrated in FIG. 28B ). The sensors 1238C may be magnetic flux sensors and may generally be positioned at one or more locations on the pole plate 1206. Exemplary magnetic flux sensors include Hall-effect sensors. The sensors 1238C measure leakage flux proximate one or more north and south poles of the pole plate 1206. The amount of leakage flux at each sensor 1238C varies based on the position of the magnetic platter 1212 relative to the pole plate 1206 and the amount of flux passing through the north and south poles of the pole plate 1206 from the workpiece contact interface 1204 to the ferromagnetic workpiece 1202. By monitoring the magnetic flux at opposite locations of the workpiece interface 1204 of the north and south poles of the pole plate 1206, the relative position of the magnetic platter 1212 can be determined. In an embodiment, the magnetic coupling device 1200 is positioned on top of the ferromagnetic workpiece 1202, and the magnetic flux measured by the sensors 1238C as the magnetic platters 1212 move from an off state to a second on state is recorded as a function of the position of the magnetic platters 1212. Each of the magnetic fluxes is assigned to a desired position on the magnetic platters 1212. An exemplary sensing system with sensors 1238C is referred to as "Magnetic Coupling Device with at Least One of a Sensor Arrangement and a Degauss No. 15 / 964,884, filed April 27, 2018, entitled "Method and Method for Reducing Stress on a Surface," the entire disclosure of which is expressly incorporated herein by reference.

[0177] In an embodiment, controller 1236 changes the state of magnetic coupling device 1200 in response to input signals received from I / O device 1246. Exemplary input devices include buttons, switches, levers, dials, touch displays, pneumatic valves, softkeys, and communication modules. Exemplary output devices include visual indicators, audio indicators, and communication modules. Exemplary visual indicators include displays, lights, and other visual systems. Exemplary audio indicators include speakers and other suitable audio systems. In an embodiment, the device 1200 includes simple visual status indicators in the form of one or more LEDs driven by the processor 1240 of the control logic 1244 to indicate when predetermined magnetic coupling device 1200 statuses are present or absent (e.g., a red LED on when the magnetic coupling device 1200 is in a first off state, a green LED blinking rapidly when the magnetic coupling device 1200 is in a second on state and a ferromagnetic workpiece 1202 is detected in proximity, a green LED blinking more slowly along with a yellow LED when contact is made with the ferromagnetic workpiece 1202 outside of a specific intended area on the ferromagnetic workpiece 1202 (e.g., partially completing a magnetic operating circuit), and a steady green LED on and yellow LED off indicating that the magnetic coupling device 1200 is engaged within threshold limits, indicating a safe magnetic coupling state).

[0178] For example, in one embodiment, the magnetic coupling device 1200 is coupled to the end of a robotic arm, and the I / O device 1246 controls the controller 1236 to place the magnetic coupling device 1200 in one of a first off state, a second on state, or a third on state. and a network interface that receives instructions from the robot controller about when to place. Exemplary network interfaces include a wired network connection and an antenna for a wireless network connection. While the embodiments discussed above relate to electronic, pneumatic, or hydraulic actuation, in alternative embodiments, the magnetic coupling device 1200 may be manually actuated by a human operator.

[0179] The magnetic coupling device 1200 may also include one or more ferromagnetic pieces 1248 disposed at or near the upper portion 1224 of the housing 1200, as illustrated in FIG. 28A . In at least one embodiment, the non-ferromagnetic mounting plate 1232 and the ferromagnetic piece 1248 are disposed within the housing 1210 such that the non-magnetic mounting plate 1232 is positioned in contact with the ferromagnetic piece 1248 when the magnetic coupling device 1200 is in the first, off position. Additionally, the top portion of the magnetic platter 1212 may contact the bottom portion of the ferromagnetic piece 1248. In another exemplary embodiment, the ferromagnetic piece 1248 may extend below the sides of the magnetic platter 1212. In these embodiments, the ferromagnetic piece 1248 may reduce leakage of the magnetic platter 1212 by providing additional absorption of the magnetic field generated by the magnetic platter 1212.

[0180] The non-ferromagnetic mounting plate 1232 is made of a non-ferromagnetic material (e.g., aluminum, austenitic stainless steel, etc.). When the magnetic coupling device 1200 is in a first off state and the magnetic platter 1212 and the non-ferromagnetic mounting plate 1232 are disposed at or near the upper portion 1218 of the housing 1204, one or more circuits between the non-ferromagnetic mounting platter 1212, the ferromagnetic piece 1248, and the non-ferromagnetic mounting plate 1232 are created, as illustrated in FIG. 28B. Additionally, when the magnetic coupling device 1200 is in the first off state, a gap 1250 (in FIG. 28A) containing air and / or another material with low magnetic susceptibility in the internal cavity 1216 is between and separates the pole plate 1206 and the magnetic platter 1212. As a result, when magnetic coupling device 1200 is in the first, off state, little or no magnetic flux from magnetic platter 1212 extends to workpiece contact interface 1204 and through ferromagnetic workpiece 1202. Thus, magnetic coupling device 1200 can be isolated from ferromagnetic workpiece 1202. Furthermore, due to the circuit between non-ferromagnetic mounting platter 1212, ferromagnetic piece 1248, and non-ferromagnetic mounting plate 1232, most, if not all, of the magnetic flux from magnetic platter 1212 is contained within housing 1210.

[0181] An additional benefit of including the ferromagnetic piece 1248 is that the distance of the gap 1250 between the bottom of the magnetic platter 1212 and the pole plate 1206 can be shorter than if the magnetic coupling device 1200 did not include the non-ferromagnetic mounting plate 1232 and the ferromagnetic piece 1248. That is, the one or more circuits created between the magnetic platter 1212, the ferromagnetic piece 1248, and the non-ferromagnetic mounting plate 1232 facilitate confining most, if not all, of the magnetic flux from the magnetic platter 1212 within the housing 1210, near the magnetic platter 1212 and away from the pole plate 1206. Thus, the magnetic flux transferred to the ferromagnetic workpiece 1202 by the magnetic coupling device 1200 is insufficient to lift one or more of the ferromagnetic workpieces 1202. Stated another way, the magnetic flux may be substantially zero at the bottom of the pole plate 1206, and therefore substantially no magnetic flux is transferred to the ferromagnetic workpiece 1202 by the magnetic coupling device 1202, reducing the overall height (see height 1282 below) required for the magnetic platter 1212 to move when the magnetic coupling device 1202 transitions between an off state and one or more on states.

[0182] Conversely, if the non-ferromagnetic mounting plate 1232 and the ferromagnetic piece 1248 are not included in the magnetic coupling device 1202, less magnetic flux from the magnetic platter 1212 will remain within the housing 1210 and / or near the magnetic platter 1212. To stay close to the platters 1212, the gap 1250 between the bottom of the magnetic platters 1212 and the pole plates 1206 must be larger to prevent magnetic flux from extending down through the pole plates 1206 and coupling the magnetic coupling device 1200 to one or more of the ferromagnetic workpieces 1202. Because the gap 1250 is smaller in the illustrated embodiment, the magnetic coupling device 1200 can be smaller than other magnetic coupling devices that do not have these features.

[0183] As an example, the gap 1250 through which the magnetic platter 1212 may move to transition from the first OFF state to the second ON state may be 8 mm or less. Conversely, to transition from the second ON state to the first OFF state, the magnetic platter 1212 may move 8 mm or less.

[0184] Another advantage of the illustrated embodiment is that, due to the smaller gap 1250, less energy can be used by the actuator 1228 to translate the magnetic platter 1212 along the vertical axis 1220 within the housing 1210. Yet another advantage of the illustrated embodiment is that the magnetic platter 1212 is less likely to break when the actuator 1228 translates the magnetic platter 1212 from the first OFF position to the second ON position and the magnetic platter 1212 comes into contact with the pole piece 1206. This is a result of the magnetic platter 1212 building up less momentum during the transition due to the reduced gap 1250. As yet another advantage of the illustrated embodiment, if the magnetic coupling device 1200 fails while in the OFF state, the non-ferromagnetic mounting plate 1232 and the ferromagnetic piece 1248 prevent the magnetic coupling device 1200 from transitioning to the ON state. Thus, magnetic coupling device 1200 is safer than a magnetic coupling device that transitions from an OFF state to an ON state when the magnetic coupling device fails. Conversely, if magnetic coupling device 1200 does not include non-ferromagnetic mounting plate 1232 and / or ferromagnetic piece 1248, magnetic platter 1212 may be more susceptible to transitioning to the ON state due to the absence of a magnetic circuit created in the OFF position.

[0185] As described above, the magnetic coupling device 1200 is in a second on state when the magnetic platter 1206 is positioned at or near the lower portion 1226 of the housing 1204. As illustrated in FIG. 29 , when the magnetic coupling device 1200 is in the second on state, magnetic flux from the magnetic platter 1206 extends through one or more of the ferromagnetic workpieces 1202. Thus, when the magnetic coupling device 1200 is in the first on state, the magnetic coupling device 1200 is configured to couple to one or more ferromagnetic workpieces 1202. Although magnetic flux lines are illustrated as passing through both ferromagnetic workpieces 1202′, 1202″, in some embodiments, the magnetic flux lines pass primarily only through the ferromagnetic workpiece 1202′. When the magnetic flux lines pass primarily through the first ferromagnetic workpiece 1202', the magnetic coupling device 1200 can be used to destack and separate the ferromagnetic workpieces 1202 from one another.

[0186] To facilitate magnetic flux lines passing primarily only through the first ferromagnetic workpiece 1202′ when magnetic coupling device 1200 is in the second on state, magnetic platters 1212 may be removable and replaceable, thereby allowing magnetic platters 1212 of different strengths, heights, and / or widths to be used with magnetic coupling device 1200. The strength, height, and / or width of magnetic platters 1212 may be selected based on the thickness of the ferromagnetic workpieces 1202 such that the ferromagnetic workpieces 1202 can be sufficiently destacked and separated from one another when magnetic coupling device 1200 is in the second on position.

[0187] Additionally or alternatively, the plates 1206 may be removable and replaceable, which This allows different types of pole plates 1206 to be used in the magnetic coupling device 1200. For example, the pole plates 1206 may be selected based on the type of ferromagnetic workpiece 1202 to which the magnetic coupling device 1200 is coupled. For example, the magnetic coupling device 1200 may handle a Class A surface that cannot be scratched or marred. As a result, pole plates 1206 having rubber (or another material that reduces the likelihood of the ferromagnetic workpiece 1202 being scratched or marred) disposed on the workpiece contact interface may be selected and incorporated into the magnetic coupling device 1200. As another example, pole plates 1206 with different protrusions and / or gaps may be selected based on the thickness of the ferromagnetic workpiece 1202 to which the magnetic coupling device 1200 is coupled. Further examples of the association of protrusions and / or gaps are described in more detail above in connection with FIGS. 6-11B.

[0188] As discussed in more detail below in connection with FIG. 31, the housing 1204 is constructed in a manner that allows the magnetic platters 1212 and / or pole plates 1206 to be easily removable and replaceable.

[0189] Additionally or alternatively, magnetic coupling device 1200 may transition to one or more intermediate states as described above. For example, magnetic coupling device 1200 may transition to a third ON state, as illustrated in FIG. 30 . The third ON state occurs when magnetic platter 1212 is positioned along vertical axis 1220 between the location of magnetic platter 1212 when magnetic coupling device 1200 is in the first OFF state and the location of magnetic platter 1212 when magnetic coupling device 1200 is in the second ON state. In embodiments where the same magnetic platter 1212 is used, less magnetic flux passes through workpiece contact interface 1204 and into ferromagnetic workpiece 1202 when magnetic coupling device 1200 is in the third ON state, as illustrated in FIG. 30 . That is, assuming magnetic platters 1212 of the same strength are used in the embodiments shown in Figures 29 and 30, magnetic flux lines pass through both ferromagnetic workpieces 1202', 1202'' in Figure 29, while magnetic flux lines pass only through ferromagnetic workpiece 1202' in Figure 30. By being able to enter the third on state, magnetic coupling device 1200 may be able to destack ferromagnetic workpieces 1202 of different thicknesses without having to replace magnetic platters 1212 with magnetic platters 1212 of different strengths.

[0190] As described above, the pole plate 1206 includes a plurality of protrusions 1208. Each of the protrusions 1208 functions as a pole extension for a respective one of the pole portions 1216. That is, when the magnetic coupling device 1200 is in the second or third ON state, the respective north or south pole of the pole portion 1216 extends down through the respective protrusion 1208. A magnetic circuit is then generated from the north pole portion 1216, through the respective north-pole protrusion 1208, through one or more ferromagnetic workpieces 1202, through the south-pole protrusion 1208, and through the south pole portion 1216. When the magnetic coupling device 1200 is in the ON state, each permanent magnetic portion generates one of these magnetic circuits. As described in more detail above in connection with FIGS. 6-11A, the size of and the distance between the protrusions 1208 affect the flux transfer to the ferromagnetic workpiece 1202, allowing for more effective destacking and increased retention of the ferromagnetic material 1202. For example, in at least some embodiments, to achieve the highest concentration of magnetic flux transferred through the ferromagnetic piece 1202' of the ferromagnetic workpiece 1202, and therefore have the best chance of destacking the ferromagnetic workpiece 1202' from the ferromagnetic workpieces 1202'', 1202''', the size of the protrusions (e.g., width and height) and the gaps therebetween should approximately match the thickness of the ferromagnetic workpiece 1202.

[0191] To separate the N and S protrusions 1208, the pole plate 1206 may include slots configured to receive one or more non-ferromagnetic pieces 1252 (shown in FIG. 28B). The non-ferromagnetic pieces 1252 may be disposed within respective envelopes 1254 (shown in FIG. 28B) between each of the protrusions 1208. The non-ferromagnetic pieces 1252 ensure that the magnetic circuit generated by the permanent magnet portion 1214 does not substantially extend through the non-ferromagnetic pieces 1252, thus separating the N and S protrusions from one another. Furthermore, as described above, the protrusions 1208 cause the magnetic flux from the magnetic platter 1212 to be closer to the workpiece contact interface 1204 than if the pole plate 1206 did not include multiple protrusions 1208. Different aspects of the protrusions 1208 that facilitate concentrating the magnetic flux from the magnetic platter 1212 closer to the workpiece contact interface 104 are discussed above in connection with FIGS. 6-11A. In an alternative embodiment, the protrusions 1208 and the recesses therebetween may be integrated directly into the housing 1210 .

[0192] 31 , an exploded view of magnetic coupling device 1200 is illustrated. As shown, housing 1210 includes a lower portion 1210A that is releasably securable to an upper portion 1210B. Lower portion 1210A may be secured to upper portion 1210B using one or more screws 1256. As described below, screws 1256 may provide easy access to components of magnetic coupling device 1210 disposed within housing 1210.

[0193] Prior to joining the lower portion 1210A and the upper portion 1210B, the lower portion 1210A receives the electrode plate 1206. In at least one embodiment, the lower portion 1210A includes a recess / notch 1258 configured to receive a tab 1260 of the electrode plate 1206. The tab 1260 facilitates proper positioning of the electrode plate 1206 within the lower portion 1210A. If a electrode plate 1206 with a different protrusion 1208 than the currently installed electrode plate 1206 is desired, proper positioning of the electrode plate 1206 can facilitate easy replacement of the electrode plate 1206. For example, the lower portion 1210A of the housing 1210 can be separated from the upper portion 1210B by removing the screw 1256. The electrode plate 1206 can then be removed from the lower portion 1210A. Another pole plate 1206 having a different protrusion 1208 can then be inserted into the lower portion 1210A such that the tab 1260 is received by the recess / notch 1258. Finally, a screw 1256 can be used to secure the lower portion 1210A to the upper portion 1210A. The tab 1260 can be constructed of a ferromagnetic material.

[0194] In addition to, or instead of, replacing the pole plate 1206, the design of the magnetic coupling device 1200 also facilitates easy removal and replacement of the magnetic platter 1212. For example, as shown, the non-ferromagnetic mounting plate 1232 is coupled to the magnetic platter 1212 via one or more screws 1261. After removing the lower portion 1210A from the upper portion 1210B, the magnetic platter 1212 can be lowered along the vertical axis 1220 so that the screws 1261 can be accessed. Once the screws 1261 are removed, the magnetic platter 1212 can be separated from the non-ferromagnetic mounting plate 1232 and replaced with another magnetic platter 1212. The new magnetic platter 1212 can be secured to the non-ferromagnetic mounting plate 1232 using the screws 1261. The lower portion 1210A and the upper portion 1210B can then be coupled together using the screws 1256.

[0195] In some cases, if the magnetic platter 1212 is broken or damaged, the magnetic platter 1212 may need to be replaced. In other cases, the magnetic platter 1212 may need to be replaced with a magnetic platter 1212 that generates a stronger or weaker magnetic field. As discussed above, replacing the magnetic platter 1212 with a magnetic platter 1212 having a stronger or weaker magnetic field may facilitate destacking of the ferromagnetic workpiece 1202. For example, the first magnetic platter 1212 may be replaced with a magnetic platter 1212 that generates a stronger or weaker magnetic field. In some cases, the first and second ferromagnetic workpieces 1202′, 1202″ may generate a magnetic flux through the first and second ferromagnetic workpieces 1202′, 1202″ sufficient to lift the workpieces 1202′, 1202″. However, it may be desirable to separate the first ferromagnetic workpiece 1202′ from the second ferromagnetic workpiece 1202″. In these cases, a second magnetic platter 1212, which is weaker than the first magnetic platter 1212 and generates only a magnetic flux through the ferromagnetic workpiece 1202 sufficient to lift the first ferromagnetic workpiece 1202′, may replace the first magnetic platter 1212.

[0196] In the illustrated embodiment, the lower portion 1228A of the actuator 1228 is coupled to the housing 1210 using one or more screws 1262. Thus, the lower portion 1228A functions as a cover for the housing 1210. Additionally, the ferromagnetic piece 1248 is coupled to the bottom portion 1228A of the actuator 1228 using one or more screws 1262. Thus, when the magnetic platter 1212 and the non-ferromagnetic mounting plate 1232 are moved to the upper portion of the housing 1210 and the magnetic coupling device 1200 is in the first, off position, the magnetic platter 1212 is positioned in contact with the ferromagnetic piece 1248. That is, contact is between the outer portion of the magnetic platter 1212 and the ferromagnetic piece 1248, as shown.

[0197] A magnetic circuit is then formed from the north pole portion 1216 of the magnetic platter 1212, through one of the ferromagnetic workpieces 1248, through the non-ferromagnetic mounting plate 1232, through the other ferromagnetic workpiece 1248, to the south pole portion 1216 of the magnetic platter 1212. The circuit offers many advantages over the magnetic coupling device 1200 discussed above.

[0198] As shown, the non-ferromagnetic mounting plate 1232 is coupled to the engagement portion 1230 with screws 1266. The engagement portion 1230 includes a first portion 1230A and a second portion 1230B, and in at least some embodiments, the first portion 1230A has a smaller cross-sectional area than the second portion 1230B. In at least one embodiment, the first portion 1230A extends through a conduit 1268 at the bottom portion 1228A and is coupled to the non-ferromagnetic mounting plate 1232 via screws 1266. By coupling the engagement portion 1230 to the non-ferromagnetic mounting plate 1232, translation of the engagement portion 1230 along the vertical axis 1220 causes the non-ferromagnetic mounting plate 1232 and the magnetic platter 1212 to translate along the vertical axis 1220.

[0199] The actuator 1228 can be pneumatically actuated to translate the engagement portion 1230 along the vertical axis 1220. For example, the actuator housing 1228B can include a port 1274 including a first port 1274A and a second port 1274B. When air is provided into the port 1274A via an air compressor or other means, pressure increases within the actuator housing 1228B and on the second portion 1230B, causing the engagement portion 1230 to move downward along the vertical axis 1220. The translation of the engagement portion 1230 causes the magnetic platter 1212 to move downward along the vertical axis 1220 such that the magnetic coupling device 1200 transitions from a first OFF state to a second ON state or a third ON state, or from the third ON state to the second ON state. To confine the air provided within the actuator housing 1228B and into port 1274A above the engagement portion 1230, the actuator 1228 may include a cover (not shown) secured to the actuator housing 1228B via one or more screws 1276. Additionally or alternatively, air may be removed from port 1274B to reduce the pressure below the second portion 1230B relative to the pressure above the second portion 1230B, causing the engagement portion 1230 to move downward along the vertical axis 1220.

[0200] Conversely, when air is provided into port 1274B, the pressure in actuator housing 1228B and below second portion 1230B increases, causing the platter to move upward along vertical axis 1220. Translation of engagement portion 1230 causes magnetic platter 1212 to move upward along vertical axis 1220 such that magnetic coupling device 1200 transitions from the second ON state to the third ON state or the first OFF state, or from the third ON state to the first OFF state. Additionally or alternatively, air may be removed from port 1274A to reduce the pressure above second portion 1230B relative to the pressure below second portion 1230B, causing engagement portion 1230 to move upward along vertical axis 1220.

[0201] In at least some other embodiments, ports 1274A, 1274B may be formed through the housing 1210B and pressure or a decrease in pressure may be applied to the top of the magnetic platter 1212 or the bottom of the magnetic platter 1212 to translate the magnetic platter 1212 along the vertical axis 1220.

[0202] 32A-32B show top cross-sectional views of the magnetic coupling device of FIGS. 28A-28B at different positions on the ferromagnetic workpiece 1202. Referring to FIG. 32A, a non-ferromagnetic magnetic platter 1212 is shown on the ferromagnetic workpiece 1202′. As shown, the entire footprint of the magnetic platter 1212 is placed on the ferromagnetic workpiece 1202′. As used herein, the term footprint may be defined as the surface area of ​​the magnetic platter 1212, i.e., width 1280×height 1282. It is preferable for the entire footprint of the magnetic platter 1212 to be placed on the ferromagnetic workpiece 1202′ because this will transfer the greatest amount of magnetic flux from the magnetic platter 1212 to the ferromagnetic workpiece 1202′. When the entire footprint of the magnetic platter 1212 is placed on the ferromagnetic workpiece 1202′, the magnetic coupling device 1200 can be configured to lift the ferromagnetic workpiece 1202 by 22.0 grams or more per square millimeter area of ​​the footprint of the magnetic platter 1212.

[0203] Although it is preferable to place the entire footprint of the magnetic platter 1212 on the ferromagnetic workpiece 1202', in many cases the magnetic platter 1212 is placed on the ferromagnetic workpiece 1202', as shown in Figure 32B. This can occur when the magnetic coupling device 1200 is mounted on the end of an arm unit for a robotic system, such as robotic system 700 (of Figure 13), and the placement of the magnetic platter 1212 on the ferromagnetic workpiece 1202' is performed using computer vision or some other automated process.

[0204] When the magnetic platter 1212 is placed on the ferromagnetic workpiece 1202′ as shown in FIG. 32B , the configuration of the magnetic platter 1212 may provide several advantages. Specifically, compared to other magnetic coupling devices, the magnetic platter 1212 may be less likely to detach from the ferromagnetic workpiece 1202′ when it lifts the ferromagnetic workpiece 1202′. That is, by including multiple permanent magnetic portions 1214 on the magnetic platter 1212, only the leftmost permanent magnetic portion 1214 detaches from the ferromagnetic workpiece 1202′ when the magnetic platter 1212 is placed on the ferromagnetic workpiece 1202′ as shown in FIG. 32B . Therefore, five other magnetic circuits are still formed between the magnetic platter 1212 and the ferromagnetic workpiece 1202′. Therefore, the magnetic platter 1212 may still operate at approximately 83% capacity (5 / 6=0.83). In comparison, if the magnetic platter 1212 includes only one permanent magnetic portion 1214, 1 / 2 of the pole portion will be displaced from the ferromagnetic workpiece 1202', resulting in 1 / 3 of the magnetic circuit not being formed with the ferromagnetic workpiece 1202'. Thus, the magnetic platter 1212 may operate at approximately 66% capacity.

[0205] 33 is a flow diagram of a method 1300 of using an exemplary switchable magnetic device with pole sectors. The method 1300 includes contacting a ferromagnetic material with a first pole sector, as indicated by block 1302. In an embodiment, the first pole sector may be attached to a base of a housing of the magnetic device. Furthermore, the magnetic device may be capable of establishing two different magnetic circuits. The first magnetic circuit may be referred to as the magnetic device in an on state, and the second magnetic circuit may be referred to as the magnetic device in an off state.

[0206] In embodiments, the first pole sector, housing, and magnetic device may each have the same or similar features as the above-described pole sectors 1034, 1134, housings 1002, 1102, and magnetic devices 1000, 1100. For example, the ferromagnetic material may be contacted by a workpiece contact interface of the first pole sector, and the workpiece contact interface of the first pole sector includes a plurality of protrusions.

[0207] The magnetic device may include at least one first permanent magnet mounted within a housing having an active north-south pole pair and at least one second permanent magnet having an active north-south pole pair. In embodiments, the at least one second permanent magnet may be rotatably mounted within the housing in a stacked relationship with the at least one first permanent magnet, and the at least one second permanent magnet may be rotatable between a first position and a second position. Additionally or alternatively, the magnetic device may establish multiple magnetic circuits generating different strengths of the magnetic circuit between the magnetic device and the ferromagnetic material.

[0208] Alternatively, the magnetic device may include at least one first permanent magnet that is movable relative to the base of the housing. Additionally or alternatively, the magnetic device may establish multiple magnetic circuits that generate different strengths of the magnetic circuit between the magnetic device and the ferromagnetic material. In embodiments, the magnetic device may generate one magnetic circuit that substantially remains within the housing when the at least one first permanent magnet is positioned and / or separated from the base of the housing.

[0209] In an embodiment, method 1300 includes contacting a ferromagnetic material with a second pole sector, as indicated by block 1304. In an embodiment, the second pole sector is mounted in the same housing as the first pole sector. In an embodiment, the magnetic device may be in the first configuration when the ferromagnetic material is contacted by the second pole sector.

[0210] In an embodiment, method 1300 includes transitioning the magnetic device from an off state to an on state, as indicated by block 1306. In an embodiment, transitioning the magnetic device from the off state to the on state may include actuating (e.g., rotating or linearly translating) at least one second permanent magnet from a first position to a second position. Further, when the magnetic device is in the on state, a magnetic circuit is formed through the workpiece.

[0211] Each of the above-disclosed magnetic coupling devices can be used in combination with a mechanical lifting device to lift and transport a ferromagnetic workpiece from a first location to a second location. Exemplary mechanical lifting devices include mechanical gantries, crane hoists, fixtures, robotic fixtures, and the like.

[0212] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the above embodiments refer to particular features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.

Claims

1. 1. A magnetic device for magnetically coupling to a ferromagnetic body, comprising: a housing having a central bore; a plurality of pole sectors disposed within the envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced apart pole portions spaced at respective distances, a recess of a plurality of recesses separating each pole portion of the plurality of pole portions, a first sector of the plurality of sectors forming a first pole of the magnetic device, and a second sector of the plurality of sectors forming a second pole of the magnetic device; at least one first permanent magnet supported by the housing and having an active north-south pole pair; at least one second permanent magnet supported by the housing and having an active north-south pole pair, the at least one second permanent magnet being movable relative to the first permanent magnet; an actuator operably coupled to the at least one second permanent magnet to move the at least one second permanent magnet relative to the at least one first permanent magnet, the actuator establishing a first magnetic circuit with the at least one first permanent magnet and the at least one second permanent magnet through the plurality of pole sectors when the at least one second permanent magnet is positioned at a first position relative to the at least one first permanent magnet by the actuator, and establishing a second magnetic circuit with the first permanent magnet and the second permanent magnet when the second permanent magnet is positioned at a second position relative to the at least one first permanent magnet by the actuator.

2. the at least one first permanent magnet comprises a first platter supported by the housing, the first platter comprising a first plurality of spaced apart permanent magnet portions, each having a north pole side and a south pole side, and a first plurality of pole portions interposed between adjacent permanent magnet portions of the first plurality of permanent magnet portions, the first platter comprising an equal number of permanent magnet portions and pole portions, the first plurality of permanent magnets being arranged such that each pole portion of the first plurality of pole portions is one of an north pole portion adjacent to the north pole sides of two permanent magnet portions of the first plurality of permanent magnet portions and an south pole portion adjacent to the south pole sides of two permanent magnet portions of the first plurality of permanent magnet portions; 2. The magnetic device of claim 1, wherein the at least one second permanent magnet comprises a second platter supported by the housing, the second platter comprising a second plurality of spaced-apart permanent magnet portions, each having a north pole side and a south pole side, and a second plurality of pole portions interposed between adjacent permanent magnet portions of the second plurality of permanent magnet portions, the second platter comprising an equal number of permanent magnet portions and pole portions, the second plurality of permanent magnets being arranged such that each pole portion of the first plurality of pole portions is one of an north pole portion adjacent to the north pole sides of two permanent magnet portions of the second plurality of permanent magnet portions and a south pole portion adjacent to the south pole sides of two permanent magnet portions of the second plurality of permanent magnet portions, and the second platter includes a rotational engagement portion.

3. The magnetic device of claim 1 or 2, wherein the actuator rotates the at least one second permanent magnet relative to the at least one first permanent magnet.

4. The magnetic device according to any one of claims 1 to 3, wherein the actuator is one of a rotary actuator and a linear actuator.

5. The actuator is configured to rotate the at least one first permanent magnet relative to the at least one second permanent magnet.

3. The magnetic device according to claim 1, wherein one second permanent magnet is linearly translated.

6. 6. The magnetic device according to claim 1, wherein the at least one second permanent magnet is housed in a second housing received in the housing, and the second housing is rotatable by the actuator to rotate the at least one second permanent magnet.

7. 1. A magnetic device for magnetically coupling to a ferromagnetic body, comprising: a housing having a central bore; a plurality of pole sectors disposed within the envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced apart pole portions spaced at respective distances, a recess of a plurality of recesses separating each pole portion of the plurality of pole portions, a first sector of the plurality of sectors forming a first pole of the magnetic device, and a second sector of the plurality of sectors forming a second pole of the magnetic device; at least one first permanent magnet supported by the housing and having an active north-south pole pair; and an actuator operably coupled to the at least one first permanent magnet to move the at least one first permanent magnet relative to a base of the housing, the actuator establishing a first magnetic circuit through the plurality of pole sectors when the at least one first permanent magnet is positioned by the actuator at a first position relative to the base of the housing, and establishing a second magnetic circuit substantially within the housing when the at least one first permanent magnet is positioned by the actuator at a second position relative to the base of the housing.

8. 8. The magnetic device of claim 1, wherein the first magnetic circuit passes through the first sector and the second sector to couple the ferromagnetic material to the magnetic device, and the second magnetic circuit remains substantially within at least a portion of the housing.

9. A magnetic device according to any preceding claim, wherein each recess of the plurality of recesses is sized to prevent the ferromagnetic material from entering the respective recess.

10. 10. The magnetic device of claim 1, wherein each of the plurality of recesses has a respective contour extending between adjacent pole pieces, the respective contour having a continuous slope.

11. 11. The magnetic device according to claim 1, wherein at least one of the plurality of recesses has a depth substantially equal to a thickness of the ferromagnetic material coupled to the magnetic device.

12. A magnetic device according to any preceding claim, wherein each of the recesses has a depth substantially equal to the thickness of the ferromagnetic material coupled to the magnetic device.

13. A magnetic device according to any preceding claim, wherein at least one of the recesses has a width substantially equal to a thickness of the ferromagnetic material coupled to the magnetic device.

14. A magnetic device according to any preceding claim, wherein each of the recesses has a width substantially equal to the thickness of the ferromagnetic material coupled to the magnetic device.

15. A magnetic device according to any preceding claim, wherein at least one of the recesses has a width substantially equal to a depth of the at least one recess.

16. A magnetic device according to any preceding claim, wherein each of the plurality of pole sectors is a single pole sector.

17. 17. The magnetic device of claim 1, wherein each of the plurality of pole sectors extends below the housing such that the housing is spaced apart from the ferromagnetic body when the workpiece contact interfaces of the first and second sectors contact the ferromagnetic body.

18. The magnetic device of any preceding claim, further comprising a compressible member disposed between each of the plurality of pole portions.

19. A magnetic device according to any preceding claim, wherein the workpiece contact interface forms a non-linear workpiece contact interface.

20. A magnetic device according to any preceding claim, wherein the workpiece contact interface forms a linear workpiece contact interface.

21. The magnetic device according to any one of the preceding claims, wherein the actuator is one of a hydraulic actuator, a pneumatic actuator, and an electric actuator.

22. 22. The magnetic device of claim 1, wherein each of the plurality of pole sectors carries a compressible component positioned to contact the ferromagnetic body when the ferromagnetic body is coupled to the magnetic device.

23. The magnetic device of any one of claims 1 to 22, wherein the magnetically coupled device is carried by at least one selected from the group of a mechanical gantry, a crane hoist, a fixture, and a robotic fixture.

24. 1. A method of mounting a magnetic device on a ferromagnetic body, the magnetic device configured to establish a first magnetic circuit and a second magnetic circuit, the magnetic device comprising: a housing having a central bore; at least one first permanent magnet supported by the housing and having an active N-S pole pair; at least one second permanent magnet supported by the housing and having an active N-S pole pair, the at least one second permanent magnet being movable relative to the first permanent magnet; and a plurality of pole sectors disposed within an envelope of the central bore and forming a workpiece contact interface of the magnetic device; contacting the ferromagnetic body with a first sector of the plurality of pole sectors, the first sector including a plurality of spaced apart pole portions disposed at respective distances that collectively form the contact interface of the first sector; contacting the ferromagnetic body with a second sector of the plurality of sectors, the second sector including a plurality of spaced apart pole portions collectively forming the contact interface of the second sector; transitioning the magnetic device from an off state to an on state.

25. 25. The method of claim 24, wherein the first magnetic circuit passes substantially through the first sector and the second sector to couple the ferromagnetic material to the magnetic device, and the second magnetic circuit remains substantially within at least a portion of the housing.

26. 1. A magnetic coupling device for magnetically coupling to a ferromagnetic workpiece, comprising: a housing having a vertical axis extending between an upper portion of the housing and a lower portion of the housing; one or more ferromagnetic pieces located at or near an upper portion of the housing; a plate support by the housing, the plate having a plurality of protrusions collectively forming a workpiece contact interface for the ferromagnetic workpiece; a magnetic platter supported by the housing, the magnetic platter comprising a plurality of permanent magnet portions and a plurality of pole portions, wherein each permanent magnet portion of the one or more permanent magnet portions is positioned adjacent to two pole portions of the plurality of pole portions such that a pole portion of the plurality of pole portions is one of a north pole portion adjacent to a north pole side of at least one permanent magnet portion of the one or more permanent magnet portions and a south pole portion adjacent to a south pole side of at least one permanent magnet portion of the one or more permanent magnet portions; a magnetic coupling device, the magnetic platter being linearly translatable within the housing along the vertical axis for at least each of a first state and a second state, the magnetic platter being positioned adjacent to the one or more ferromagnetic pieces such that when the magnetic platter is in the first state, the magnetic coupling device establishes a first magnetic circuit through the one or more ferromagnetic pieces to provide a first magnetic field at the workpiece contact interface of the magnetic coupling device, and the magnetic platter being positioned spaced apart from the one or more ferromagnetic pieces such that when the magnetic platter is in the second state, the magnetic coupling device provides a second magnetic field at the workpiece contact interface, the second magnetic field having a non-zero magnetic field strength.

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