Linear actuated magnetic coupling device

Abstract

To provide a magnetic coupling device configured to be linearly actuated and de-actuated for magnetic coupling to a ferromagnetic workpiece.SOLUTION: A magnetic coupling device 100 includes a housing 110 having an axis 120 extending between a first end 124 of the housing 110 and a second end 126 of the housing 110, one or more ferromagnetic workpieces 102 disposed at least a first distance from the second end 126 of the housing 110, and a magnetic platter 112 supported by the housing 110. The magnetic platter 112 includes a plurality of permanent magnet portions inserted between a plurality of pole portions.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to magnetic coupling devices, and more particularly, to magnetic coupling devices configured to be linearly actuated and deactuated. [Background technology]

[0002] The magnetic coupling device is used to couple a ferromagnetic workpiece to transport the ferromagnetic workpiece from a first location to a second location, to hold the ferromagnetic workpiece, and / or to lift the ferromagnetic workpiece. An exemplary magnetic coupling device is a switchable magnetic coupling device that may include a magnetic platter that is linearly translatable between an "off" position and an "on" position. When the magnetic platter is in the "on" state, the magnetic coupling device is configured to couple to the ferromagnetic workpiece to perform, for example, lifting operations, material handling, material holding, magnetic latching, or coupling objects together, among other applications. Summary of the Invention

[0003] SUMMARY OF THE DISCLOSURE The embodiments contained herein relate to magnetic coupling devices configured to be linearly actuated and deactuated. Embodiments include, but are not limited to, the following examples:

[0004] In a first exemplary embodiment, a magnetic coupling device for magnetically coupling to a ferromagnetic workpiece comprises a housing having an axis extending between a first end of the housing and a second end of the housing, an ferromagnetic piece disposed at least a first distance from the second end of the housing, and a magnetic platter supported by the housing, the magnetic platter including a plurality of permanent magnet portions interposed between a plurality of ferromagnetic pole piece portions, the magnetic platter being linearly translatable within the housing along the axis to each of at least a first state and a second state, the magnetic platter being disposed adjacent to the ferromagnetic piece such that when the magnetic platter is in the first state, the magnetic coupling device establishes a first magnetic circuit through the ferromagnetic piece and provides a first magnetic field at a workpiece contact interface of the magnetic coupling device, and the magnetic platter being disposed spaced from the ferromagnetic piece 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 being a non-zero magnetic field strength.

[0005] In a second exemplary embodiment, a method of coupling and decoupling a magnetic coupler to a ferromagnetic workpiece includes contacting the ferromagnetic workpiece with a workpiece engagement interface of the magnetic coupler, moving a magnetic platter of the magnetic coupling device from a first separation from the workpiece engagement surface to a second separation from the workpiece engagement surface that is less than the first separation, moving the workpiece from the first position to a second position using the magnetic coupler, and moving the magnetic platter from the workpiece engagement surface to a third separation to decouple the magnetic coupler from the workpiece and form a magnetic circuit through an ferrous piece in a housing, the third separation being greater than the second separation.

[0006] In a third exemplary embodiment, a magnetic coupling device for magnetically coupling to a ferromagnetic workpiece includes a housing having a passageway defining a passageway axis, a magnetic platter supported by the housing, the magnetic platter being movable between a first position and a second position along the passageway axis, the magnetic platter including a plurality of permanent magnet portions interposed between a plurality of ferromagnetic pole piece portions, a workpiece contact interface supported by the housing and adapted to contact the ferromagnetic workpiece, and a magnetic shunt supported by the housing and magnetically accessible from the passageway, the magnetic platter being adapted to contact the ferromagnetic workpiece. With the platter in a first position, a first magnetic circuit is formed with the magnetic platter and the magnetic shunt, and with the magnetic platter in a second position, a second magnetic circuit is formed with the magnetic platter and the ferromagnetic workpiece through the workpiece interface.

[0007] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief description of the drawings]

[0008] [Figure 1A] 1 illustrates a side cross-sectional view of an exemplary magnetic coupling device in an exemplary first off state positioned on a ferromagnetic workpiece. [Figure 1B] 1B illustrates a front cross-sectional view of the magnetic coupling device of FIG. 1A. [Figure 1C] FIG. 1B illustrates a front view of the magnetic coupling device of FIG. 1A. [Diagram 2] 1C illustrates a front cross-sectional view of the magnetic coupling device of FIGS. 1A-1C in a second, on state. [Diagram 3] FIG. 1C illustrates a front cross-sectional view of the magnetic coupling device of FIGS. 1A-1C in a third, on state. [Figure 4]FIG. 2 illustrates an exploded view of the magnetic coupling device of FIGS. 1A-1C. [Diagram 5] 1A-1C in a first position on a ferromagnetic workpiece; FIG. [Figure 6] FIG. 1C illustrates a top cross-sectional view of the magnetic coupling device of FIGS. 1A-1C in a second position on a ferromagnetic workpiece. [Figure 7] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 8] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 9] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 10] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 11] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 12] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 13] 1A-1C are exemplary portions of pole plates that can be incorporated into the magnetic coupling device of FIGS. [Figure 14] 1A-1C illustrate a robotic system including the example magnetic coupling device of FIGS. 1A-1C mounted as the end of an arm coupler. [Figure 15] 1A-1C depict a top cross-sectional view of an exemplary sensor layout of the magnetic coupling device; [Figure 16] 1A-1C depict a simplified front view of the magnetic coupling device of FIGS. 1A-1C without a ferromagnetic workpiece in the vicinity of the magnetic coupling device of FIGS. 1A-1C. [Figure 17] FIG. 2 illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C and a ferromagnetic workpiece separated from the magnetic coupling device by a first separation. [Figure 18]FIG. 2 illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C and a ferromagnetic workpiece separated from the magnetic coupling device. [Figure 19] FIG. 1C illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C tilted from left to right relative to a ferromagnetic workpiece. [Figure 20] 1A-1C depict simplified front views of the magnetic coupling device of FIGS. 1A-1C tilted back and forth relative to a ferromagnetic workpiece; [Figure 21] FIG. 1C illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C contacting a right end portion of a ferromagnetic workpiece. [Figure 22] FIG. 2 illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C contacting a central portion of a ferromagnetic workpiece. [Figure 23] FIG. 1C illustrates a simplified front view of the magnetic coupling device of FIGS. 1A-1C contacting a ferromagnetic workpiece in a first extreme position. [Figure 24] FIG. 1C illustrates a simplified front view of the end of the arm magnetic coupling device of FIGS. 1A-1C contacting a ferromagnetic workpiece in a second extreme position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the specific embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0010] In the figures, as well as in previous sections of this specification, terms such as "upper," "lower," "axial," and other reference terms are used to facilitate understanding of the technology described herein, and should not be considered as absolute and limiting reference indicators unless the context dictates otherwise. The terms "couple," "coupled," "coupler," and variations thereof are used to include both arrangements in which two or more components are in direct physical contact and arrangements in which two or more components are not in direct contact with each other (e.g., the components are "coupled" through at least a third component), but still cooperate or interact with each other.

[0011] FIG 1A illustrates a side cross-sectional view of an exemplary switchable magnetic coupling device 100 in a first, OFF state, FIG 1B illustrates a front cross-sectional view of the magnetic coupling device 100, and FIG 1C illustrates a front view of the magnetic coupling device 100. FIG 2 illustrates a front cross-sectional view of the magnetic coupling device of FIG 1A-1C in a second, ON state. FIG 3 illustrates a front cross-sectional view of the magnetic coupling device of FIG 1A-1C in a third, ON state.

[0012] The magnetic coupling device 100 may be switched between a first OFF state (shown in FIGS. 1A-1C), a second ON state (shown in FIG. 2), and / or a third ON state. When the magnetic coupling device 100 is switched to the ON state, the magnetic field generated by the magnetic coupling device 100 passes through one or more of the ferromagnetic workpieces 102, coupling the magnetic coupling device 100 to one or more of the ferromagnetic workpieces 102. When the magnetic coupling device 100 is switched to the OFF state, the magnetic field generated by the magnetic coupling device 100 remains primarily within the magnetic coupling device 100, and thus the magnetic coupling device 100 is no longer coupled to one or more of the ferromagnetic workpieces 102. The OFF and ON states are discussed in more detail below.

[0013] The magnetic coupling device 100 may be used as an end of an arm ("EOAMT") unit for a robotic system, such as robotic system 600 (see FIG. 14), but may also be used in other lifting, transporting, and / or separation systems for the ferromagnetic workpiece 102. Exemplary lifting and transporting systems include robotic systems, mechanical gantries, crane hoists, and additional systems for lifting and / or transporting the ferromagnetic workpiece 102. Additionally, the magnetic coupling device 100 may be used as part of a fixture to hold at least a portion of the workpiece for operations such as welding, inspection, and other operations. It can also be used.

[0014] 1A, the magnetic coupling device 100 is positioned on top of the ferromagnetic workpiece 102 and includes a workpiece contact interface 104 configured to contact and engage the ferromagnetic workpiece 102. The workpiece contact interface 104 can be a pole plate 106. In at least one embodiment, the pole plate 106 includes a plurality of spaced apart protrusions 108, as illustrated in FIG. 1B. In other embodiments, the pole plate 106 does not include the spaced apart protrusions 108. The spaced apart protrusions 108 can facilitate concentrating more magnetic flux near the workpiece contact interface 104 such that the magnetic flux of the magnetic coupling device 100 passes primarily through the first ferromagnetic workpiece 102' when the magnetic coupling device 100 is in an on state. Exemplary aspects of the pole plate 106 and the protrusions 108 are discussed below.

[0015] The magnetic coupling device 100 also includes a housing 110 that supports a magnetic platter 112. The magnetic platter 112 generates a magnetic field that allows the magnetic coupling device 100 to couple to the ferromagnetic workpiece 102 when the magnetic coupling device 100 is in an on state. In at least one embodiment, the magnetic platter 112 is a laminated magnetic platter that includes a plurality of spaced apart permanent magnet portions 114 and a plurality of pole portions 116, as shown in FIG. 1B. Each of the plurality of spaced apart permanent magnet portions 114 includes one or more permanent magnets. In one embodiment, each permanent magnet portion 114 includes one permanent magnet. In another embodiment, each permanent magnet portion 114 includes multiple permanent magnets. Each permanent magnet portion 114 is diametrically magnetized and has a north-pole side and a south-pole side.

[0016] Each pole portion 116A is positioned between two permanent magnet portions 114, and the pole portion 116B is disposed adjacent to one permanent magnet portion 114. Furthermore, the permanent magnet portions 114 are disposed such that each of the two permanent magnet portions 114 in contact with the pole portion 116A between them has either their N-pole side or their S-pole side in contact with the pole portion 116A. When the N-pole side of the adjacent permanent magnet portion 114 contacts the pole portion 116A, the pole portion 116A is referred to as the N-pole portion. When the S-pole side of the adjacent permanent magnet portion 114 contacts the pole portion 116A, the pole portion 116A is referred to as the S-pole portion. Similarly, for the pole portion 116B, when the S-pole side of the permanent magnet portion 114 contacts the pole portion 116B, the pole portion 116B is referred to as the S-pole portion. Conversely, when the N-pole side of the permanent magnet portion 114 contacts the pole portion 116B, the pole portion 116B is referred to as the N-pole portion.

[0017] In the embodiment shown, the permanent magnet portions 114 are arranged along a horizontal axis 118. However, in other embodiments, the permanent magnet portions 114 may be arranged in a circular configuration. Additionally, while the embodiment illustrates the magnetic platter 112 including six permanent magnet portions 114 and seven pole portions 116, other embodiments may include more or fewer permanent magnet portions 114 and pole portions 116. For example, in one embodiment, the magnetic platter 112 may include one permanent magnet portion 114 and two pole portions 116, with one pole portion 116 disposed on each side of the permanent magnet portion 114.

[0018] Due to the configuration of the magnetic platters 112 and the magnetic coupling device 100, the magnetic coupling device 100 may have a greater magnetic flux transfer to one or more of the ferromagnetic pieces 102 than prior embodiments. This results in the magnetic coupling device 100 being able to lift more and / or heavier ferromagnetic workpieces 102 per magnetic volume contained within the magnetic coupling device 100. For example, the magnetic coupling device 100 may have a retention force of 0.35 grams or more of ferromagnetic workpieces 102 per cubic mm of volume of the magnetic coupling device 100. As another example, the magnetic coupling device 100 may have a retention force of 0.8 grams or more per cubic mm of volume of the housing 110 of the magnetic coupling device 100. It may have a ferromagnetic workpiece 102 holding force.

[0019] To switch the magnetic coupling device 100 between a first OFF state and a second ON state, the magnetic platter 112 is linearly translatable along an axis 120 within an internal cavity 122 of the housing 104. In an embodiment, the axis 120 is a vertical axis 120. Alternatively, the axis 120 is an axis other than a vertical axis. The axis 120 extends between a first end 124 of the housing 104 and a second end 126 of the housing 110. In at least some embodiments, the first end 124 is an upper portion of the housing 110 and the second end 126 is a lower portion of the housing 110 and may be referred to as such herein. However, in at least some other embodiments, the first end 124 is a portion of the housing 110 other than the upper portion of the housing 110 and the second end 126 is a portion of the housing 110 other than the lower portion of the housing 110. When the magnetic platter 112 is disposed near the upper portion 124 of the housing 110, the magnetic coupling device 100 is in a first OFF state. When the magnetic platter 112 is disposed near the lower portion 126 of the housing 110, the magnetic coupling device 100 is in a second ON state. In addition to the first OFF state and the second ON state, the magnetic platter 112 may be disposed in one or more intermediate positions between the upper portion 124 and the lower portion 126, as shown in FIG. 3 . 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 104 than the second ON state. For example, the third on state can result in a majority of the magnetic flux extending only through the first workpiece 102', such that only a small amount of magnetic flux extends through the second and third workpieces 102", 102'''. Thus, the third on state can facilitate destacking the workpiece 102' from the workpieces 102", 102''', as shown.

[0020] To translate the magnetic platter 112 along the vertical axis 120 to transition the magnetic coupling device 100 between an ON state and an OFF state, and vice versa, the magnetic coupling device 100 includes an actuator 128. In at least one embodiment, the actuator 128 is coupled to the magnetic platter 112 via an engagement portion 130 and a non-ferromagnetic mounting plate 132. That is, the actuator 128 is coupled to the engagement portion 130, which is coupled to the non-ferromagnetic mounting plate 132, which is coupled to and in contact with the magnetic platter 112. The actuator 128 is configured to exert a force on the engagement portion 130, which in response translates along the vertical axis 120 to transition the magnetic coupling device 100 from an OFF state to an ON state, and vice versa. That is, to transition the magnetic coupling device 100 from an OFF state to an ON state, the actuator 128 exerts a downward force on the non-ferromagnetic mounting plate 132 and the engagement portion 130 which translates to the magnetic platter 112. In response, the magnetic platter 112 translates from the upper portion 124 to the lower portion 126. Conversely, to transition the magnetic coupling device 100 from an ON state to an OFF state, the actuator 128 exerts an upward force on the non-ferromagnetic mounting plate 132 and the engagement portion 130 which translates to the magnetic platter 112. In response, the magnetic platter 112 and the non-ferromagnetic mounting plate 132 translate from the lower portion 126 to the upper portion 124.

[0021] To place the magnetic platter 112 in the third ON state, the actuator 128 may generate a force on the engagement portion 130 to translate the magnetic platter 112 from the upper portion 124 to the lower portion 126, or vice versa. Then, as the magnetic platter 112 is translating from the upper portion 124 to the lower portion 126, or vice versa, a brake 134 disposed within the housing 110 and / or within the actuator 128 engages the magnetic platter 112, the non-ferromagnetic mounting plate 132, and / or the engagement portion 130, as shown in FIG. 3, to stop the magnetic platter 112 in the third ON state.

[0022] Exemplary actuators 128 include electric actuators, pneumatic actuators, hydraulic actuators, and other suitable devices that impart a force on the engagement portion 130. An exemplary pneumatic linear actuator is shown in and discussed in more detail in connection with FIGURE 4. An exemplary electric actuator is an electric motor with an "unroll" stator and rotor coupled to the engagement portion 130. Other 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, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," Docket No. MTI-0007-01-US-E, and ... Patent No. 6,161,451, entitled "MODULAR PERMANENT MAGNETIC CHUCK," U.S. Patent No. 8,878,639, entitled "MAGNETIC COUPLING DEVICE WITH A ROTARY ACTUATION SYSTEM," Docket No. MTI-0007-01-US-E, and U.S. Patent No. 6,161,451, entitled "MAGNETIC COUPLING DEVICE WITH A LINEAR ACTUATION SYSTEM," Docket No. MTI-0007-01-US-E, and U.S. Patent No. 6,161,451, entitled "MODULAR PERMANENT MAGNETIC CHUCK," Docket No. MTI-0007-01-US-E, and U.S. Patent No. 6,161,451, entitled "MODULAR PERMANENT MAGNETIC No. 62 / 252,435, filed Nov. 7, 2015, entitled "METHOD FOR IMPROVING A HIGH-SPEED PHOTO-RELATED SYSTEM," Docket No. MTI-0006-01-US-E, the entire disclosure of which is expressly incorporated herein by reference.

[0023] Additionally or alternatively, the actuator 128 may include a controller 136 and / or a sensor 138A. The controller 136 includes a processor 140 along with associated computer-readable media, illustratively a memory 142. The memory 142 includes control logic 144 that, when executed by the processor 140, causes the electronic controller 136 to instruct the actuator 128 to move the magnetic platters 112 such that the magnetic device 100 is in an off state, a second on state, and / or a third on state. For example, the sensor 138A may sense the position of the actuator 128, and in response to a predetermined position sensed by the sensor 138A translating to the position of the magnetic platters 112, the control logic 144 instructs the actuator 128 to stop exerting a force on the magnetic platters 112 when the magnetic platters 112 reach a desired position.

[0024] In at least one embodiment, the actuator 128 is a stepper motor, and the rotational motion of the actuator 128 is translated into linear motion of the engagement portion 130 via a coupling (e.g., gears) between the shaft of the actuator 128 and the engagement portion 130. In these embodiments, the sensor 138A 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 translated into the position of the magnetic platter 112. That is, the magnetic platter 112 is relatively moved along the vertical axis 120 to a defined position by the steps the motor moves by counting the number of pulses. In another example, a stepper motor is provided that integrates an encoder with the stepping to ensure that the proper actuation angle is maintained.

[0025] As another example, the magnetic coupling device 100 may include a sensor 138B. The sensor 138B may measure the position of the magnetic platter 112 within the housing 110. An exemplary sensor 138B includes an optical sensor that monitors a reflective strip affixed to the magnetic platter 112. Other sensor systems may be used to determine the position of the magnetic platter 112.

[0026] As yet another example, the magnetic coupling device 100 may include one or more sensors 138C (illustrated in FIG. 1B). The sensor 138C may be a magnetic flux sensor and may generally be positioned at one or more locations on the pole plate 106. Exemplary magnetic flux sensors include Hall effect sensors. The sensor 138C may detect one or more north and south poles of the pole plate 106. The leakage flux at each sensor 138C is measured adjacent the south pole. The amount of leakage flux at each sensor 138C varies based on the position of the magnetic platter 112 relative to the pole plate 106 and the amount of flux passing through the north and south poles of the pole plate 106 from the workpiece contact interface 104 to the ferromagnetic workpiece 102. By monitoring the magnetic flux at opposite locations of the workpiece interface 104 of the north and south poles of the pole plate 106, the relative position of the magnetic platter 112 can be determined. In an embodiment, the magnetic coupling device 100 is positioned on top of the ferromagnetic workpiece 102, and the magnetic flux measured by the sensor 138C as the magnetic platter 112 moves from an off state to a second on state is recorded as a function of the position of the magnetic platter 112. Each of the magnetic fluxes is assigned to a desired position of the magnetic platter 112. An exemplary sensing system having sensor 138C is disclosed in U.S. patent application Ser. No. 15 / 964,884, filed April 27, 2018, entitled “Magnetic Coupling Device with at Least One of a Sensor Arrangement and a Degauss Capability,” the entire disclosure of which is expressly incorporated by reference into this specification.

[0027] As yet another example, the magnetic coupling device 100 may include one or more sensors 138D (illustrated in FIGS. 1A, 1B, 1C, 2, and 3). The sensors 138D may be magnetic flux sensors and may generally be positioned adjacent to the pole plates 106. Exemplary magnetic flux sensors include Hall effect sensors. In at least one example, the sensors 138D are positioned adjacent to the ends of one or more protrusions 108 of the pole plates 106 and measure leakage flux from the sides of one or more north and south poles of the pole plates 106. The amount of leakage flux at each sensor 138D varies based on the position of the magnetic platter 112 relative to the pole plates 106 and the amount of flux that passes through the north and south poles of the pole plates 106 and the workpiece contact interface 104 to reach the ferromagnetic workpiece 102. By monitoring the magnetic flux at locations adjacent to the pole plates 106, the relative position of the magnetic platter 112 may be determined. In an embodiment, the magnetic coupling device 100 is positioned on top of the ferromagnetic workpiece 102, and the magnetic flux measured by the sensor 138D as the magnetic platter 112 moves from an OFF state to a second ON state is recorded as a function of the position of the magnetic platter 112. Each of the magnetic fluxes is assigned to a desired position on the magnetic platter 112. An exemplary sensing system having the sensor 138D is disclosed in U.S. patent application Ser. No. 15 / 964,884, filed Apr. 27, 2018, entitled "Magnetic Coupling Device with at Least One of a Sensor Arrangement and a Degauss Capability," the entire disclosure of which is expressly incorporated herein by reference.

[0028] In at least some embodiments, the magnetic coupling device 100 includes a shield plate 139 (illustrated in FIGS. 1A, 1B, 1C, 2, and 3). The shield plate 139 can absorb magnetic flux from the magnetic platter 112 and reduce the external magnetic field of the magnetic coupling device 100 when the magnetic coupling device 100 is in the off position. The shield plate 139 can be formed from a high magnetic saturation material that can absorb a large amount of magnetic flux. In one example, the shield plate 139 is located on the exterior of the housing 110. The upper edge of the shield plate 139 can be planar with the top surface of the magnetic platter 112. Additionally or alternatively, the shield plate 139 can extend downwardly along the housing 110 such that the lower edge of the shield plate 139 extends beyond the bottom plane of the magnetic platter 112. The shield plate 139 can be located on any side of the magnetic coupling device 100. In at least one embodiment, the shield plate 139 is located on all sides of the magnetic coupling device 100. In another embodiment, the shield plate 139A is located only on the face of the magnetic coupling device 100 adjacent the end of the permanent magnet portion 114, as shown in Figures 1A and 1C. Stated differently, the shield plate 139A may be located on the same side(s) as the sensor 138D. In another embodiment, the shield plate 139B is located on the side of the magnetic coupling device 100 that extends parallel to the protrusion 108, as shown in Figures 2 and 3. Located only on the side of 110.

[0029] In an embodiment, the controller 136 changes the state of the magnetic coupling device 100 in response to input signals received from the I / O device 146. 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 100 includes a simple visual status indicator in the form of one or more LEDs driven by the processor 140 of the control logic 144 to indicate when a predetermined magnetic coupling device 100 status is present or absent (e.g., a red LED on when the magnetic coupling device 100 is in a first off state, a green LED flashing rapidly when the magnetic coupling device 100 is in a second on state and a ferromagnetic workpiece 102 is detected in proximity, a green LED flashing more slowly along with a yellow LED when contact is made with the ferromagnetic workpiece 102 outside of a specific intended area on the ferromagnetic workpiece 102 (see discussion related to Figures 22-24) (e.g., a partially complete magnetic actuation circuit), and a steady green LED on with the yellow LED off indicates that the magnetic coupling device 100 is engaged within threshold limits, indicating a safe magnetic coupling state).

[0030] For example, in one embodiment, the magnetic coupling device 100 is coupled to the end of a robotic arm and the I / O device 146 is a network interface through which the controller 136 receives instructions from the robot controller as to when to place the magnetic coupling device 100 in one of a first OFF state, a second ON state, or a third ON 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 magnetic coupling device 100 may be manually actuated by a human operator.

[0031] The magnetic coupling device 100 may also include one or more ferromagnetic pieces 148 disposed at or near the upper portion 124 of the housing 100, as illustrated in FIG. 1A. In at least one embodiment, the non-ferromagnetic mounting plate 132 and the ferromagnetic piece 148 are disposed within the housing 110 such that the non-ferromagnetic mounting plate 132 is positioned in contact with the ferromagnetic piece 148 when the magnetic coupling device 100 is in the first off position. Additionally, a top portion of the magnetic platter 112 may contact a bottom portion of the ferromagnetic piece 148. In another exemplary embodiment, the ferromagnetic piece 148 may extend under the sides of the magnetic platter 112. In these embodiments, the ferromagnetic piece 148 may reduce leakage of the magnetic platter 112 by providing additional absorption of the magnetic field generated by the magnetic platter 112.

[0032] In at least one embodiment, the non-ferromagnetic mounting plate 132 can be made of a non-ferromagnetic material (e.g., aluminum, austenitic stainless steel, etc.). In these embodiments, when the magnetic coupling device 100 is in the first off state and the magnetic platter 112 and the non-ferromagnetic mounting plate 132 are located at or near the upper portion 118 of the housing 104, one or more circuits between the mounting platter 112, the ferromagnetic piece 148, and the non-ferromagnetic mounting plate 132 are created as illustrated in FIG. 1B. Additionally, when the magnetic coupling device 100 is in the first off state, a gap 150 (in FIG. 1A ), comprising air and / or another material having low magnetic susceptibility in the interior cavity 116, is between and separates the pole plate 106 and the magnetic platter 112. As a result, when the magnetic coupling device 100 is in the first off state, the magnetic flux from the magnetic platter 112 is directed to the workpiece contact 116, and the magnetic flux from the workpiece contact 116 ... Little or nothing extends to the interface 104 and through the ferromagnetic workpiece 102. Thus, the magnetic coupling device 100 may be isolated from the ferromagnetic workpiece 102. Furthermore, because of the circuitry between the mounting platter 112, the ferromagnetic piece 148, and the non-ferromagnetic mounting plate 132, most, if not all, of the magnetic flux from the magnetic platter 112 is contained within the housing 110.

[0033] An additional benefit of including the ferromagnetic piece 148 is that the distance of the gap 150 between the bottom of the magnetic platters 112 and the pole plates 106 can be shorter than if the magnetic coupling device 100 did not include the non-ferromagnetic mounting plate 132 and the ferromagnetic piece 148. That is, the one or more circuits created between the magnetic platters 112, the ferromagnetic piece 148, and the non-ferromagnetic mounting plate 132 facilitate confining most, if not all, of the magnetic flux from the magnetic platters 112 within the housing 110, near the magnetic platters 112 and away from the pole plates 106. Thus, the magnetic flux transferred by the magnetic coupling device 100 to the ferromagnetic workpieces 102 is insufficient to lift the one or more ferromagnetic workpieces 102. Said another way, the magnetic flux can be effectively zero at the bottom of the pole plate 106, and therefore effectively no magnetic flux is transferred by the magnetic coupling device 102 to the ferromagnetic workpiece 102, which reduces the overall required height (see height 182 below) that the magnetic platter 112 must move when the magnetic coupling device 102 transitions between an off state and one or more on states.

[0034] Conversely, if the non-ferromagnetic mounting plate 132 and ferromagnetic piece 148 were not included in the magnetic coupling device 102, less magnetic flux from the magnetic platters 112 would remain within the housing 110 and / or near the magnetic platters 112. And because less magnetic flux would remain near the magnetic platters 112, the gap 150 between the bottom of the magnetic platters 112 and the pole plates 106 would have to be larger to prevent the magnetic flux from extending down through the pole plates 106 and coupling the magnetic coupling device 100 to one or more of the ferromagnetic work pieces 102. Because the gap 150 is smaller in the illustrated embodiment, the magnetic coupling device 100 may be smaller than other magnetic coupling devices that do not have these features.

[0035] As an example, the gap 150 through which the magnetic platter 112 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 112 may move 8 mm or less.

[0036] Another advantage of the illustrated embodiment is that due to the smaller gap 150, less energy may be used by the actuator 128 to translate the magnetic platter 112 along the vertical axis 120 within the housing 110. Yet another advantage of the illustrated embodiment is that the magnetic platter 112 is less likely to break when the actuator 128 translates the magnetic platter 112 from the first OFF position to the second ON position and the magnetic platter 112 comes into contact with the pole piece 106. This is a result of the magnetic platter 112 building up less momentum during the transition due to the reduced gap 150. As yet another advantage of the illustrated embodiment, if the magnetic coupling device 100 fails while it is in the OFF state, the magnetic coupling device 100 will not transition to the ON state due to the non-ferromagnetic mounting plate 132 and ferromagnetic piece 148. Thus, the magnetic coupling device 100 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 the magnetic coupling device 100 does not include the non-ferromagnetic mounting plate 132 and / or the ferromagnetic piece 148, the magnetic platter 112 may be more likely to transition to the ON state due to the absence of a magnetic circuit created in the OFF position.

[0037] As mentioned above, the magnetic platter 106 is mounted on or in the lower portion 126 of the housing 104. 2, when the magnetic coupling device 100 is in the second on state, the magnetic flux from the magnetic platter 106 extends through one or more of the ferromagnetic workpieces 102. Thus, when the magnetic coupling device 100 is in the first on state, the magnetic coupling device 100 is configured to couple to one or more ferromagnetic workpieces 102. Although the magnetic flux lines are illustrated as passing through both ferromagnetic workpieces 102', 102", in some embodiments, the magnetic flux lines pass primarily only through the ferromagnetic workpiece 102'. When the magnetic flux lines pass primarily through the first ferromagnetic workpiece 102', the magnetic coupling device 100 may be used to destack and separate the ferromagnetic workpieces 102 from one another.

[0038] To facilitate the magnetic flux lines passing primarily only through the first ferromagnetic workpiece 102′ when the magnetic coupling device 100 is in the second ON state, the magnetic platters 112 may be removable and replaceable, thereby allowing magnetic platters 112 of different strengths, heights, and / or widths to be used with the magnetic coupling device 100. The strength, height, and / or width of the magnetic platters 112 may be selected based on the thickness of the ferromagnetic workpieces 102 such that the ferromagnetic workpieces 102 may be sufficiently destacked and separated from one another when the magnetic coupling device 100 is in the second ON position.

[0039] Additionally or alternatively, the pole plates 106 may be removable and replaceable, allowing different types of pole plates 106 to be used with the magnetic coupling device 100. For example, the pole plates 106 may be selected based on the type of ferromagnetic workpiece 102 to which the magnetic coupling device 100 is coupled. For example, the magnetic coupling device 100 may handle a Class A surface that cannot be scratched or marred. As a result, a pole plate 106 having rubber (or another material that reduces the likelihood that the ferromagnetic workpiece 102 will be scratched or marred) disposed on the workpiece contact interface may be selected and incorporated into the magnetic coupling device 100. As another example, pole plates 106 having different protrusions and / or gaps may be selected based on the thickness of the ferromagnetic workpiece 102 to which the magnetic coupling device 100 is coupled. Further examples of the association of protrusions and / or gaps are described in more detail below in connection with FIGS. 7-13.

[0040] As will be discussed in more detail below in connection with FIG. 4, the housing 104 is constructed in a manner that allows the magnetic platters 112 and / or pole plates 106 to be easily removable and replaceable.

[0041] Additionally or alternatively, the magnetic coupling device 100 may transition to one or more intermediate states as described above. For example, the magnetic coupling device 100 may transition to a third ON state, as illustrated in FIG. 3. The third ON state is when the magnetic platter 112 is located along the vertical axis 120 between the location of the magnetic platter 112 when the magnetic coupling device 100 is in the first OFF state and the location of the magnetic platter 112 when the magnetic coupling device 100 is in the second ON state. In an embodiment in which the same magnetic platter 112 is used, less magnetic flux passes through the workpiece contact interface 104 and into the ferromagnetic workpiece 102 when the magnetic coupling device 100 is in the third ON state than when the magnetic coupling device 100 is in the second ON state, as illustrated in FIG. That is, assuming that magnetic platters 112 of the same strength are used in the embodiments shown in Figures 2 and 3, the magnetic flux lines pass through both ferromagnetic workpieces 102', 102" in Figure 2, while the magnetic flux lines pass only through the ferromagnetic workpiece 102' in Figure 3. By being capable of entering a third on state, the magnetic coupling device 100 may be able to destack ferromagnetic workpieces 102 of different thicknesses without having to replace the magnetic platters 112 with magnetic platters 112 of different strength.

[0042] As mentioned above, the pole plate 106 includes a plurality of protrusions 108. Each of the protrusions 108 functions as a pole extension for a respective one of the pole pieces 116. That is, when the magnetic coupling device 100 is in the second or third ON state, the respective north or south pole of the pole piece 116 extends down through the respective protrusion 108. A magnetic circuit is then created from the north pole piece 116, through the respective north-pole protrusion 108, through one or more ferromagnetic workpieces 102, through the south-pole protrusion 108, and through the south pole piece 116. Each permanent magnet piece creates one of these magnetic circuits when the magnetic coupling device 100 is in the ON state. As described in more detail below in connection with FIGS. 7-13, the size of and distance between the protrusions 108 affect the flux transfer to the ferromagnetic workpiece 102, allowing for more effective de-stack and increased retention of the ferromagnetic material 102. For example, in at least some embodiments, to achieve the highest concentration of magnetic flux transferred through the ferromagnetic piece 102' of the ferromagnetic workpiece 102, and therefore have the best chance of being able to destack the ferromagnetic workpiece 102' from the ferromagnetic workpieces 102", 102''', the size of the protrusions (e.g., width and height) as well as the gaps therebetween should approximately match the thickness of the ferromagnetic workpiece 102.

[0043] To separate the N and S protrusions 108, the pole plate 106 may include slots configured to receive one or more non-ferromagnetic pieces 152 (shown in FIG. 1B). The non-ferromagnetic pieces 152 may be disposed within respective envelopes 154 (shown in FIG. 1B) between each of the protrusions 108. The non-ferromagnetic pieces 152 cause the magnetic circuit created by the permanent magnet portion 114 to not extend substantially through the non-ferromagnetic pieces 152, thus separating the N and S protrusions from one another. Additionally, as discussed above, the protrusions 108 cause the magnetic flux from the magnetic platter 112 to be closer to the workpiece contact interface 104 than if the pole plate 106 did not include the multiple protrusions 108. Different aspects of the protrusions 108 that facilitate concentrating the magnetic flux from the magnetic platter 112 closer to the workpiece contact interface 104 are discussed below in connection with FIGS. 7-13.

[0044] 4, an exploded view of the magnetic coupling device 100 is illustrated. As shown, the housing 110 includes a lower portion 110A that is releasably securable to an upper portion 110B. The lower portion 110A may be secured to the upper portion 110B using one or more screws 156. As described below, the screws 156 may provide easy access to components of the magnetic coupling device 110 disposed within the housing 110.

[0045] Prior to joining the lower portion 110A and the upper portion 110B, the lower portion 110A receives the plate 106. In at least one embodiment, the lower portion 110A includes a recess / notch 158 configured to receive a tab 160 of the plate 106. The tab 160 facilitates proper positioning of the plate 106 within the lower portion 110A. If a plate 106 with a different protrusion 108 than the currently installed plate 106 is desired, the proper positioning of the plate 106 may facilitate easy replacement of the plate 106. For example, the lower portion 110A of the housing 110 may be separated from the upper portion 110B by removing the screw 156. The plate 106 may then be removed from the lower portion 110A. Thereafter, another plate 106 having a different protrusion 108 may be inserted into the lower portion 110A such that the tab 160 is received by the recess / notch 158. Finally, screws 156 may be used to secure the lower portion 110A to the upper portion 110A.

[0046] In addition to, or instead of, replacing the pole plates 106, the design of the magnetic coupling device 100 also facilitates easy removal and replacement of the magnetic platters 112. For example, as shown, a non-ferromagnetic mounting plate 132 is attached to the magnetic platters 112 via one or more screws 161. 1. After removing lower portion 110A from upper portion 110B, magnetic platter 116 may be lowered along vertical axis 120 so that screws 161 may be accessed. Once screws 161 are removed, magnetic platter 116 may be separated from non-ferromagnetic mounting plate 132 and replaced with another magnetic platter 116. The new magnetic platter 116 may be secured to non-ferromagnetic mounting plate 132 using screws 161. Lower portion 110A and upper portion 110B may then be coupled together using screws 156.

[0047] In some cases, if the magnetic platter 116 is broken or damaged, the magnetic platter 116 may need to be replaced. In other cases, the magnetic platter 116 may need to be replaced with a magnetic platter 116 that generates a stronger or weaker magnetic field. As discussed above, replacing the magnetic platter 116 with a magnetic platter 116 having a stronger or weaker magnetic field may facilitate de-stacking of the ferromagnetic workpiece 102. For example, the first magnetic platter 116 may generate sufficient magnetic flux through the first and second ferromagnetic workpieces 102', 102" to lift both ferromagnetic workpieces 102', 102". However, it may be desirable to separate the first ferromagnetic workpiece 102' from the second ferromagnetic workpiece 102". In these cases, the first magnetic platter 116 may be replaced with a second magnetic platter 116 that is weaker than the first magnetic platter 116 and generates only enough magnetic flux through the ferromagnetic workpiece 102 to lift the first ferromagnetic workpiece 102'.

[0048] In the illustrated embodiment, the lower portion 128A of the actuator 128 is coupled to the housing 110 using one or more screws 162. Thus, the lower portion 128A functions as a cover for the housing 110. Additionally, the ferromagnetic piece 148 is coupled to the bottom portion 128A of the actuator 128 using one or more screws 162. Thus, when the magnetic platter 112 and the non-ferromagnetic mounting plate 132 are moved to the upper portion of the housing 110 and the magnetic coupling device 100 is in the first off position, the magnetic platter 112 and the non-ferromagnetic mounting plate 132 are positioned near and / or in contact with the ferromagnetic piece 148. A magnetic circuit is then formed from the north pole portion 116 of the magnetic platter 112, through one of the ferromagnetic workpieces 148, through the non-ferromagnetic mounting plate 132, through the other ferromagnetic workpiece 148, to the south pole portion 116 of the magnetic platter 112. The circuit provides many advantages over the magnetic coupling device 100 discussed above.

[0049] As shown, the non-ferromagnetic mounting plate 132 is coupled to the engagement portion 130 with screws 166. The engagement portion 130 includes a first portion 130A and a second portion 130B, where in at least some embodiments, the first portion 130A has a smaller cross-sectional area than the second portion 130B. In at least one embodiment, the first portion 130A extends through a conduit 168 at the bottom portion 128A and is coupled to the non-ferromagnetic mounting plate 132 via screws 166. By coupling the engagement portion 130 to the non-ferromagnetic mounting plate 132, translation of the engagement portion 130 along the vertical axis 120 causes the non-ferromagnetic mounting plate 132 and the magnetic platter 112 to translate along the vertical axis 120.

[0050] The actuator 128 may be pneumatically actuated to translate the engagement portion 130 along the vertical axis 120. For example, the actuator housing 128B may include a port 174 including a first port 174A and a second port 174B. When air is provided into the port 174A, via an air compressor or otherwise, pressure increases in the actuator housing 128B and above the second portion 130B, which causes the engagement portion 130 to move downward along the vertical axis 120. The translation of the engagement portion 130 causes the magnetic platter 112 to move in a direction perpendicular to the axis of the magnetic coupling device 100 as the magnetic coupling device 100 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. 1. To confine the air provided within the actuator housing 128B and into port 174A above the engagement portion 130, the actuator 128 may include a cover (not shown) secured to the actuator housing 128B via one or more screws 176. Additionally or alternatively, air may be removed from port 174B to reduce the pressure below the second portion 130B relative to the pressure above the second portion 130B, which will cause the engagement portion 130 to move downward along the vertical axis 120.

[0051] Conversely, when air is provided into port 174B, the pressure in the actuator housing 128B and below the second portion 130B increases, causing the plate to move upward along the vertical axis 120. Translation of the engagement portion 130 causes the magnetic platter 112 to move upward along the vertical axis 120 such that the magnetic coupling device 100 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 can be removed from port 174A to reduce the pressure above the second portion 130B relative to the pressure below the second portion 130B, causing the engagement portion 130 to move upward along the vertical axis 120.

[0052] In at least some other embodiments, ports 174A, 174B may be formed through the housing 110B and pressure or a reduction in pressure may be applied to the top of the magnetic platter 112 or the bottom of the magnetic platter 112 to translate the magnetic platter 112 along the vertical axis 120.

[0053] 5 and 6 illustrate top cross-sectional views of the magnetic coupling device of FIGS. 1A-1B at different positions on the ferromagnetic workpiece 102. Referring to FIG. 5, the magnetic platter 112 is shown on the ferromagnetic workpiece 102′. As shown, the entire footprint of the magnetic platter 112 is placed on the ferromagnetic workpiece 102′. As used herein, the term footprint may be defined as the surface area of ​​the magnetic platter 112, i.e., width 180 by height 182. It is preferred that the entire footprint of the magnetic platter 112 is placed on the ferromagnetic workpiece 102′ in order for the greatest amount of magnetic flux to be transferred from the magnetic platter 112 to the ferromagnetic workpiece 102′. When the entire footprint of the magnetic platter 112 is placed on the ferromagnetic workpiece 102′, the magnetic coupling device 100 may be configured to lift 22.0 grams or more of the ferromagnetic workpiece 102 per square millimeter area of ​​the footprint of the magnetic platter 112.

[0054] While it is preferable to place the entire footprint of the magnetic platter 112 on the ferromagnetic workpiece 102', often the magnetic platter 112 is placed on the ferromagnetic workpiece 102' as shown in Figure 6. This may occur when the magnetic coupling device 100 is mounted on the end of an arm unit for a robotic system, such as robotic system 600 (of Figure 14), and placement of the magnetic platter 112 on the ferromagnetic workpiece 102' has been performed using the determined position of the magnetic coupling device 100, computer vision, and / or some other automated process.

[0055] 6, when the magnetic platter 112 is placed on the ferromagnetic workpiece 102', the configuration of the magnetic platter 112 may provide several advantages. Specifically, compared to other magnetic coupling devices, the magnetic platter 112 may be less likely to peel off from the ferromagnetic workpiece 102' when the magnetic platter 112 lifts the ferromagnetic workpiece 102'. That is, because multiple permanent magnet portions 114 are included in the magnetic platter 112, when the magnetic platter 112 is placed on the ferromagnetic workpiece 102' as shown in FIG. 6, only the left-most permanent magnet portion 114 is attached to the ferromagnetic workpiece 102'. 102'. Thus, five other magnetic circuits are still formed between the magnetic platter 112 and the ferromagnetic workpiece 102'. Thus, the magnetic platter 112 may still operate at approximately 83% capacity (5 / 6=.83). In comparison, if the magnetic platter 112 included only one permanent magnet portion 114, 1 / 3 of the magnetic circuits would not be formed with the ferromagnetic workpiece 102' because 1 / 3 of the pole portions would be displaced from the ferromagnetic workpiece 102'. Thus, the magnetic platter 112 may operate at approximately 66% capacity. As another example, if the magnetic platter had a circular footprint including one or more north poles and one or more south poles, and the magnetic platter was only partially placed on the ferromagnetic workpiece 102, a large portion of one or more of the poles would be displaced from the ferromagnetic workpiece 102, thereby significantly reducing the holding force of the magnetic platter.

[0056] As mentioned above, the pole plates 106 can have spaced apart projections 108. Referring to Figures 7-13, there are exemplary portions of the pole plates 106 and projections 108 that can be incorporated into the magnetic coupling devices of Figures 1A-1C.

[0057] 7 is a side view of a portion of an exemplary portion of a plate 200 that can be used as plate 106. Plate 200 includes a plurality of protrusions 206 disposed on a bottom portion 208 of plate 200. Each of the protrusions 206 is separated by recesses 210. In addition, the plurality of protrusions 206 collectively form a workpiece contact interface 212 of plate 200.

[0058] Due to the multiple protrusions 206 included on the pole plate 200, a magnetic coupling device including the pole plate 200 generates a stronger magnetic field near the workpiece contact interface 212 than a magnetic coupling device including a pole plate that does not include the protrusions 206. 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 plate 200, a magnetic coupling device including the pole plate 200 generates a weaker magnetic field at a greater depth from the pole plate 200 than a magnetic coupling device that does not include the protrusions 206. The magnetic field generated farther from the pole plate 200 may be referred to herein as a far-field magnetic field or a deep magnetic field generated by the pole plate 200. Stated another way, a magnetic device including the pole plate 200 with the protrusions 206 has a stronger coercive force near the workpiece contact interface 212 than a magnetic device including a pole plate with a continuous interface of the same height that does not include the protrusions 206.

[0059] As a result of the protrusions 206 of the pole plate 200 facilitating the generation of a stronger shallow magnetic field and a weaker far-field magnetic field, a magnetic coupling device including the pole plate 200 may be used to destack the thin ferromagnetic workpieces 102 better than a magnetic coupling device having a pole plate without the protrusions 206. That is, a magnetic device including a pole plate without the protrusions 206 may generate a stronger far-field magnetic field that results in multiple thin ferromagnetic workpieces 102 being coupled to the magnetic coupling device. This is an undesirable result when attempting to obtain a single thin ferromagnetic workpiece 102 from a stacked array of thin ferromagnetic workpieces 102. Thus, instead of using a magnetic device including a pole plate without the protrusions 206 to destack the ferromagnetic workpieces 102, the pole plate 200 including the protrusions 206 may be used.

[0060] In an embodiment, by varying the width 214 of the protrusions 206, different shallow magnetic fields can be generated by the same magnetic coupling device. For example, as the width 214 of the magnetic protrusions 206 increases, the shallow magnetic field decreases and the far-field magnetic field increases. Thus, to generate a preferred shallow magnetic field for a particular ferromagnetic workpiece 102, the width 214 of the protrusions 206 can have a width within about + / - 25% of the thickness of the ferromagnetic workpiece 102 being destacked. For example, when the magnetic coupling device destacks a ferromagnetic workpiece 102 that is 2 mm thick, the width 214 of the protrusions 206 can be within about 2 mm (e.g., 2 mm + / - 25%). In an embodiment, this creates a strong shallow magnetic field at a depth of 0 mm to 2 mm from the workpiece contact interface 212. However, in at least one embodiment, there may be a limit on creating a preferred shallow magnetic field for some ferromagnetic workpieces 102 having a thickness below the limit. That is, for ferromagnetic workpieces 102 having a thickness less than X mm, a preferred shallow magnetic field may be created by a protrusion 206 having a width 214 that is at the lower limit of X mm but not less than the lower limit. That is, to create a preferred magnetic field for a workpiece 102 having a thickness of ½*X mm, the width 214 of the protrusion 206 may be at the lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece 102 is X mm or greater, the width 214 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. 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.

[0061] In at least one embodiment, a pole plate 200 having a width 214 that is the average of the thickness of the ferromagnetic workpieces may be used to reduce the need to change pole plates when a magnetic coupling device including the pole plate 200 is coupled to ferromagnetic workpieces 102 having different thicknesses. However, as above, a lower limit (e.g., 2.0 mm) may apply, such that if the average thickness of the ferromagnetic workpieces 102 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).

[0062] In an embodiment, by varying the depth 216 and / or width 218 of the recess 210, different shallow magnetic fields will be generated by the same magnetic coupling device 100. In an embodiment, to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece 102, the depth 216 and / or width 218 of the recess 210 may be approximately the same (e.g., + / - 25%) as 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 may be approximately 2 mm (e.g., 2 mm + / - 25%). In an embodiment, this generates a strong shallow magnetic field at a depth of 0 mm to 2 mm from the contact interface 212. However, similar to the above, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces 102 having a thickness below the limit. That is, for a ferromagnetic workpiece 102 having a thickness less than X mm, a preferred shallow magnetic field may be generated by a depth 216 and width 218 that is at the lower limit of X mm but not less than the lower limit. That is, to generate a favorable magnetic field for a ferromagnetic workpiece 102 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 workpiece 102 is X mm or greater, the depth 216 and width 218 may be approximately equal to the thickness of the ferromagnetic workpiece 102 (e.g., + / −25%).

[0063] Similar to the above, a pole plate 200 having a depth 216 and / or width 218 of the recess 210 that is an average of the thickness of the ferromagnetic workpiece 102 may be used to reduce the need to change the pole plate when a magnetic coupling device 100 including the pole plate 200 is coupled to a ferromagnetic workpiece 102 having a different thickness. Additionally, a lower limit (e.g., 2.0 mm) may be applied such that if the average thickness of the ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm), the depth 216 and width 218 may be configured to be at the lower limit (i.e., 2.0 mm).

[0064] The pole plate 200 may be releasably coupled to the magnetic coupling device 100. Thus, when the protrusions 206 of the pole plate 200 do not have a suitable width 214, depth 216, and / or width 218 for the ferromagnetic workpiece 102 to which the magnetic device 100 is coupled, the pole plate 200 may be replaced with a more suitable pole plate 200.

[0065] 8 is a side view of a portion of another exemplary portion of a plate 300 that can be used as plate 106. Similar to plate 200 shown in FIG. 7, plate 300 includes a plurality of protrusions 306 disposed on a bottom portion 308 of plate 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 plate 300.

[0066] 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 coupling device 100. In an embodiment, to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece 102, 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 workpiece 102 coupled to the magnetic coupling device 100. However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces 102 having a thickness below a limit. That is, for a ferromagnetic workpiece 102 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 the lower limit of X mm but is greater than or equal to the lower limit. That is, to generate a favorable magnetic field for a ferromagnetic workpiece 102 having a thickness of ½*X mm, width 314, depth 316, and / or width 318 may be a lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece 102 is X mm or greater, width 314, depth 316, and / or width 318 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. An example of a lower limit may range from 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0067] Alternatively, a pole plate 300 having a width 314, depth 316, and / or width 318 that is approximately the average of the thickness of the ferromagnetic workpiece 102 may be used to reduce the need to change pole plates when a magnetic coupling device including pole plate 300 is coupled to ferromagnetic workpieces 102 having different thicknesses. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that if the average thickness of the ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm), then width 314, depth 316, and / or width 318 may be configured to be at the lower limit (i.e., 2.0 mm).

[0068] 9, the recesses 310 between the protrusions 306 may have a continuous sloped profile (slope defined at all points, no sharp corners) at their upper ends. The curved recesses 310 may have a higher magnetic flux transfer to the ferromagnetic workpiece 102 than a magnetic coupling device including a pole plate including a recess with a sharp corner. In an embodiment, to provide high magnetic flux transfer, the radius of curvature 324 of the curved recesses 310 may be about 1 / 2 the width 318 of the recesses 310. Test data indicates that by including a sloped profile in the recesses 310 that is 1 / 2 the width 318 of the recesses 324, an improvement of over 3% may be obtained.

[0069] 10 is a side view of a portion of another exemplary plate 400 that can be used as plate 106. Similar to plates 200, 300 shown in FIGS. 6 and 7, respectively, plate 400 includes a plurality of protrusions 406 disposed on a bottom portion 408 of plate 400. Each of the protrusions 406 is separated by recesses 410. The plurality of protrusions 406 collectively form a workpiece contact interface 412 of plate 400.

[0070] Similar to the above, by varying the width 414 of the protrusions 406 and / or the depth 416 and / or width 418 of the recesses 410, different shallow magnetic fields may be generated by the same magnetic coupling device 100. In an embodiment, the width 414 of the protrusions 406 and / or the depth 416 and / or width 418 of the recesses 410 may be varied to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece 102. The depth 416 and / or width 418 of the ferromagnetic workpiece 102 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces 102 having a thickness below the limit. That is, for ferromagnetic workpieces 102 having a thickness less than X mm, a preferred shallow magnetic field may be generated by width 414, depth 416, and / or width 418 that is at the lower limit of X mm but is equal to or greater than the lower limit. That is, to generate a preferred magnetic field for a ferromagnetic workpiece 102 having a thickness of ½*X mm, 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 workpiece 102 is equal to or greater than X mm, width 414, depth 416, and / or width 418 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. An example of the lower limit can be in the range of 0 mm to 2 mm, however, this is merely an example and is not meant to be limiting.

[0071] Alternatively, a pole plate 400 having a width 414, depth 416, and / or width 418 that is an average of the thickness of the ferromagnetic workpiece 102 may be used to reduce the need to change pole plates when a magnetic coupling device including pole plate 400 is coupled to ferromagnetic workpieces 102 having different thicknesses. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that if the average thickness of the ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm), then width 414, depth 416, and / or width 418 may be configured to be at the lower limit (i.e., 2.0 mm).

[0072] In an embodiment, the pole plate 400 may also include a compressible member 420 disposed between the protrusions 406 at the recesses 410. In an embodiment, when a magnetic device 100 including the pole plate 400 is coupled to a ferromagnetic workpiece 102, the compressible member 420 compresses. The compression of the compressible member 420 creates a static friction between the compressible member 420 and the ferromagnetic workpiece 102 that is potentially greater than the static friction between the protrusions 406 and the ferromagnetic workpiece 102. Thus, a ferromagnetic workpiece 102 coupled to a magnetic device 100 including the pole plate 400 may be less likely to rotate and translate than if the ferromagnetic workpiece 102 was coupled to a pole plate that does not include the compressible member 420. In an embodiment, the compressible member 420 may be comprised of a resilient material, such as a polymer of isoprene, polyurethane, nitrile rubber, and / or the like.

[0073] 11A-11B illustrate another exemplary electrode plate 500 that can be used as electrode plate 106. Similar to electrodes 200, 300, 400 shown in FIGS. 7, 8, and 10, electrode plate 500 includes a plurality of protrusions 502 disposed on a bottom portion 504 of electrode plate 500. Each of the protrusions 502 is separated by recesses 506. The plurality of protrusions 502 collectively form a workpiece contact interface 508 of electrode plate 500.

[0074] As shown, the workpiece contact interface 508 is non-planar. In an embodiment, the non-planar workpiece contact interface 508 may facilitate coupling the magnetic coupling device 100 to a ferromagnetic workpiece having a non-planar surface. For example, the magnetic coupling device 100 including the pole plate 500 may be used to couple the magnetic coupling device 100 to one or more types of rods, shafts, etc. (e.g., camshafts). Although the workpiece contact interface 508 includes a curved surface 510, the workpiece contact interface 508 may have any other type of non-planar surface. For example, the workpiece contact interface 508 may include a contour similar to the ferromagnetic piece that the magnetic coupling device including the workpiece contact interface 508 is intended to couple to.

[0075] Despite having a non-planar workpiece contact interface 508, different shallow magnetic fields will be generated by the same magnetic coupling device by varying the width 512 of the protrusion 502 and / or the depth 514 and / or width 516 of the recess 506. In an embodiment, to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece 102, the width 512 of the protrusion 502 and / or the depth 514 and / or width 516 of the recess 506 may be approximately the same as the thickness of the ferromagnetic workpiece 102 (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 102 having a thickness below a limit. That is, for a ferromagnetic workpiece 102 having a thickness less than X mm, a preferred shallow magnetic field may be generated by a width 512, depth 514, and / or width 516 that is at the lower limit of X mm but is greater than or equal to the lower limit. 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 a lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece 102 is X mm or greater, width 512, depth 514, and / or width 516 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. An example of a lower limit may range from 0 mm to 2 mm. However, this is merely an example and is not meant to be limiting.

[0076] Alternatively, a pole plate 500 having a width 512, depth 514, and / or width 516 that is an average of the thickness of the ferromagnetic workpiece 102 may be used to reduce the need to change pole plates when a magnetic coupling device including the pole plate 500 is coupled to ferromagnetic workpieces 102 having different thicknesses. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that if the average thickness of the ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm), the width 512, depth 514, and / or width 516 may be configured to be at the lower limit (i.e., 2.0 mm).

[0077] 12A-12B illustrate another exemplary plate 550 that can be used as plate 106. Similar to plates 200, 300, 400, 500 illustrated in FIGS. 7, 8, 10, and 11A-11B, plate 550 includes a plurality of protrusions 552 disposed on a bottom portion 554 of plate 550. Each of protrusions 552 is separated by a recessed portion 556. The plurality of protrusions 552 collectively form a workpiece contact interface 558 of plate 550.

[0078] As shown, the workpiece contact interface 558 is non-planar. In embodiments, the non-planar workpiece contact interface 558 may facilitate coupling the magnetic coupling device 100 to a ferromagnetic workpiece having a non-planar surface. For example, the magnetic coupling device including the pole plate 550 may be used to couple the magnetic coupling device 100 to one or more edges, corners, etc. of a ferromagnetic workpiece. The workpiece contact interface 558 includes two downwardly sloping surfaces 560 extending from a center point 562, although the workpiece contact interface 558 may have any other type of non-planar surface. For example, the workpiece contact interface 558 may include a contour similar to the ferromagnetic piece with which the magnetic coupling device including the workpiece contact interface 558 is intended to couple.

[0079] Despite having a non-planar workpiece contact interface 558, different shallow magnetic fields may 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 an embodiment, the width 564 of the protrusions 552 and / or the depth 566 and / or width 568 of the recesses 556 may be varied to generate an appropriate shallow magnetic field for a particular ferromagnetic workpiece 102. The width 564, depth 566, and / or width 568 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. However, in at least one embodiment, there may be a limit on generating a preferred shallow magnetic field for some ferromagnetic workpieces 102 having a thickness below a limit. That is, for ferromagnetic workpieces 102 having a thickness less than X mm, a preferred shallow magnetic field may be generated by width 564, depth 566, and / or width 568 that is at the lower limit of, but not less than, X mm. That is, to generate a preferred magnetic field for a ferromagnetic workpiece 102 having a thickness of ½*X mm, width 564, depth 566, and / or width 568 may be at the lower limit of X mm instead of + / - 25% of ½*X mm. However, if the thickness of the ferromagnetic workpiece 102 is X mm or greater, width 564, depth 566, and / or width 568 may be approximately equal (e.g., + / - 25%) to the thickness of the ferromagnetic workpiece 102. An example of the lower limit can be in the range of 0 mm to 2 mm, however, this is merely an example and is not meant to be limiting.

[0080] Alternatively, a pole plate 550 having a width 564, depth 566, and / or width 568 that is an average of the thickness of the ferromagnetic workpiece 102 may be used to reduce the need to change pole plates when a magnetic coupling device including the pole plate 550 is coupled to ferromagnetic workpieces 102 having different thicknesses. However, similar to above, a lower limit (e.g., 2.0 mm) may apply such that if the average thickness of the ferromagnetic workpiece 102 is less than the lower limit (i.e., <2.0 mm), the width 564, depth 566, and / or width 568 may be configured to be at the lower limit (i.e., 2.0 mm).

[0081] 13 is a side view of a portion of an exemplary protrusion 206. As shown, each protrusion 206 may itself include a protrusion 206'. The protrusion 206' may further increase the shallow magnetic field and decrease the far field magnetic field as compared to if the protrusion 206 did not include the protrusion 206'. In an alternative embodiment, the protrusion 206 may not include the protrusion 206'.

[0082] Other properties of the plates are described in U.S. Provisional Patent Application No. 62 / 623,407, filed January 29, 2018, entitled "MAGNETIC LIFTING DEVICE HAVING POLE SHOES WITH SPACED APART PROJECTIONS," Docket No. MTI-0015-01-US-E, the entire disclosure of which is expressly incorporated herein by reference.

[0083] In view of reviewing the foregoing disclosure of FIGS. 7-13, the following average separation forces for various types of plates 106 are provided in the table below.

[0084] [Table 1]

[0085] 14, an exemplary robotic system 600 is illustrated. Although the robotic system 600 is illustrated in FIG. 14, the embodiments described in connection therewith may be implemented in other types of machines (e.g., crane hoists, pick-and-place machines, robotic fixtures, etc.). , etc.

[0086] The robotic system 600 includes an electronic controller 136. The electronic controller 136 includes additional logic stored in associated memory 142 for execution by the processor 140. A robot movement module 602 is included that controls movement of a robotic arm 604. In the illustrated embodiment, the robotic arm 604 includes a first arm segment 606 that is rotatable relative to a base about a vertical axis. The first arm segment 606 is movably coupled to a second arm segment 608 through a first joint 610, such that the second arm segment 608 can be rotated relative to the first arm segment 606 in a first direction. The second arm segment 608 is movably coupled to a third arm segment 611 through a second joint 612, such that the third arm segment 611 can be rotated relative to the second arm segment 608 in a second direction. The third arm segment 611 is movably coupled to the fourth arm segment 614 through a third joint 616 such that the fourth arm segment 614 can be rotated relative to the third arm segment 611 in a third direction and the orientation of the fourth arm segment 614 relative to the third arm segment 611 can be changed by a revolute joint 618. The magnetic coupling device 100 is illustratively shown fixed to the end of the robot arm 604. The magnetic coupling device 100 is used to couple a ferromagnetic workpiece 102 (not shown) to the robot arm 604.

[0087] In one embodiment, the electronic controller 136 by the processor 140 executing the robot transfer module 602 moves the robot arm 604 to a first pose, where the magnetic coupling device 100 contacts the ferromagnetic workpiece 102 at a first location. The electronic controller 136 by the processor 140 executing the control logic 144 commands the magnetic device 100 to transition from a first OFF state to a second ON state or a third ON state to couple the ferromagnetic workpiece 102 to the robot system 600. The electronic controller 136 by the processor 140 executing the robot transfer module 602 moves the ferromagnetic workpiece 102 from the first location to a second, desired, spaced location. Once the ferromagnetic workpiece 102 is in the desired second location, the electronic controller 136 by the processor 140 executing the control logic 144 commands the magnetic coupling device 100 to transition from the second ON state to the first OFF state to decouple the ferromagnetic workpiece 102 from the robot system 600. The electronic controller 136 then repeats the process of coupling, moving, and decoupling another ferromagnetic workpiece 102 .

[0088] In an embodiment, the control logic 144 may also determine the presence, absence, or other characteristics of the ferromagnetic workpiece 102 associated with the magnetic coupling device 100. To do so, the magnetic coupling device 100 may include one or more magnetic field sensors. Referring to FIG. 15, a representative top cross-sectional view of the magnetic coupling device 100 including the magnetic field sensors 702 is illustrated. The magnetic field sensors 702 are positioned as described herein, with a first magnetic field sensor 702A positioned on a left half 704 of the magnetic coupling device 100 and a second magnetic field sensor 702B positioned on a right half 706 of the magnetic coupling device 100. In addition, a third magnetic field sensor 702C is positioned on a front half 708 of the magnetic coupling device 100 and a fourth magnetic field sensor 702D is positioned on a rear half 710 of the magnetic coupling device 100. The front half 708 includes a first portion 712 of the left half 704 and a first portion 714 of the right half 706. The rear half 710 includes a second portion 716 of the left half 704 and a second portion 718 of the right half 706. The addition of the third and fourth magnetic field sensors 702C, 702D provides additional sensor values ​​that may be used to determine various operating conditions of the magnetic coupling device 100. For example, the control logic 144 based on the output of the four magnetic field sensors can determine the orientation of the workpiece contact interface 104 relative to the ferromagnetic workpiece 102 in two rotational axes, such as left-to-right tilt and front-to-right tilt. It can be determined.

[0089] Turning now to the functional blocks of the control logic 144, the simplest information required for the magnetic coupling device 100 is the switching state of the magnetic coupling device 100, i.e. the unit is in a partial on state, such as a first off state, a second on state, or a third on state. In the first off state, the magnetic coupling device 100 has very little or no leakage flux. In the second on state, even on a nearly complete magnetic actuation circuit with the ferromagnetic workpiece 102, the magnetic coupling device 100 has significantly more leakage flux than in the first off state. Thus, in a calibration process, one or more readings of the first magnetic field sensor 702 in the off state of the magnetic coupling device 100 may be stored as calibrated or hard-coded values ​​in the memory 142 (see FIG. 15 ) associated with the processor 140 of the control logic 144, and when the magnetometer readings exceed this first off state value or experience some offset above this off state value, the magnetic coupling device 100 may be considered to be in a partial on state, such as the second on state or the third on state. When the magnetometer readings are at or near the calibration stored values, the magnetic coupling device 100 may be considered to be in the first off state. In embodiments, through a calibration process, one or more readings of the first magnetic field sensor 702 that are in a desired partial on state may be stored in memory 142 as a calibration or hard-coded value, and when the magnetometer reading rises to or within a certain percentage of a particular stored reading, the magnetic coupling device 100 may be considered to be in a corresponding partial on state, such as a third on state. In some embodiments, the magnetic field sensor 702 may be supplemented with one or more position sensors that are used to determine the position of the magnetic platter 112 to calibrate the magnetic coupling device 100.

[0090] When the magnetic coupling device 100 is in the ON state, another function block of the control logic 144 can be used to determine whether there is a ferromagnetic workpiece 102 under only the left half 704, only the right half 706, or under both the left half 704 and the right half 706. If there is no target portion for the magnetic coupling device 100 to magnetically attach to (see FIG. 16), there is no "true" (i.e., externally actuated) magnetic circuit through the pole plates 106 (see FIG. 1B). Assuming that any workpiece 102 is far enough away from the pole plates 106 so as not to distort the magnetic field, the magnetic flux will spread through the air between the pole portions 116 (in FIG. 1B), effectively representing leakage flux. This also causes high leakage flux to be present at the magnetic field sensor 702. By storing this "maximum leakage flux" for a given second on state, or partial on state such as a third on state, in the memory 142 associated with the processor 140 of the control logic 144, either hard-coded (assuming this value remains unchanged) or from a calibration run during normal operation of the magnetic coupling device 100, it is possible to determine whether a ferromagnetic workpiece 102 is present by placing the magnetic coupling device 100 in a partial state such as the second state or the third state in a state corresponding to the stored "maximum leakage flux" reference value and comparing the output of the current sensor to the stored "maximum leakage flux" reference value for the on state or partial on state.

[0091] In addition to detecting the presence or absence of the workpiece 102, the logical control logic 144 may also provide an indication of the spacing of the workpiece contact interface 104 from the workpiece 102 when the presence of the ferromagnetic workpiece 102 is detected (the current sensor value is below a stored "maximum leakage flux" for presence detection). In an embodiment, the control logic 144 is configured to determine whether the workpiece contact interface 104 is in proximity to the ferromagnetic workpiece 102. In one example, the control logic 144 may detect the presence or absence of the workpiece contact interface 104 when the current value of the corresponding sensor 702 falls below a threshold value. The control logic 144 determines whether the magnetic coupling unit 104 is in proximity to the workpiece 102. The threshold value may be determined during a calibration run and stored in the memory 142 and may correspond to a known spacing between the workpiece contact interface 104 and the workpiece 102 (see FIG. 17). In one embodiment, multiple threshold values ​​are stored in the memory 142, each corresponding to a respective known spacing. The multiple stored threshold values ​​allow the control logic 144 to provide a better approximation of the spacing between the workpiece contact interface 104 and the workpiece 102 and to distinguish between a first spacing (see FIG. 17) and a second, smaller spacing (see FIG. 18). Among other advantages, the ability to accurately determine the proximity of the workpiece allows the robot system 600 (see FIG. 14) to move at a higher speed until the magnetic coupling unit 100 is within a first spacing from the workpiece 102, and then move at a lower speed until it makes contact with the workpiece 102. In embodiments, for the various calibration runs and values ​​discussed herein, separate calibration runs or values ​​are taken for different types of ferromagnetic materials due to the fact that target sensor readings may differ based on the respective sizes, shapes, materials, etc. of the target ferromagnetic workpieces.

[0092] In an embodiment, the control logic 144 is configured to determine an orientation of the first workpiece contact interface 104 and the second workpiece contact interface 104 relative to the ferromagnetic workpiece 102. In one example, the orientation of the left half 704 of the workpiece contact interface 104 and the right half 706 of the workpiece contact interface 104 relative to the ferromagnetic workpiece 102 is determined by comparing the output of the first magnetic field sensor 702A to the output of the second magnetic field sensor 702B. The first spacing between the left half 704 of the workpiece contact interface 104 and the ferromagnetic workpiece 102 and the second spacing between the right half 706 of the workpiece contact interface 104 and the ferromagnetic workpiece 102 are determined to be generally equal by the control logic 144 when the output of the first magnetic field sensor 702A and the output of the second magnetic field sensor 702B meet a first criterion. In one example, the first criterion is that the output of the first magnetic field sensor 702A is within a threshold amount of the output of the second magnetic field sensor 702B. An example of the threshold amount is an absolute difference. In another example, the threshold amount is a percentage difference. When the first criterion is met, the left half 704 and the right half 706 of the workpiece contact interface 104 have a generally equal spacing relative to the workpiece 102 (see FIG. 18). When the first criterion is not met, the left half 704 and the right half 706 of the workpiece contact interface 104 are angled relative to the workpiece 102 (see FIG. 19). When a third and fourth magnetic field sensor are incorporated as shown in FIG. 15, in addition to the angle about the roll axis shown in FIG. 19, the angle about the pitch axis (see FIG. 20) can also be determined. Additionally or alternatively, the incorporation of a three-dimensional magnetic flux sensor can determine the angle about the pitch axis (see FIG. 20) and / or the angle about the roll axis shown in FIG. 19.

[0093] In addition to these device status and workpiece detection functions, the presence and specific location of at least two magnetic field sensors 702 at designated locations on the pole plate 106 provides more advanced feedback since the situation-dependent, potentially non-uniform, leakage flux distribution around the individual pole segments 116 of the pole plate 106 can be sampled, compared, and evaluated.

[0094] Second, in an embodiment, in an ON state of the magnetic coupling device 100 (equally applicable to the known partial ON state), if the left half 704 of the workpiece contact interface 104 of the pole plate 106 is in good contact with the ferromagnetic workpiece 102, but the right half 706 of the workpiece contact interface 104 is in poor contact with the workpiece 102 (see FIG. 21 ), there will be more leakage flux in the right half 706 than in the left half 704. The sensor 702B on the right half 706 can detect this condition, with the sensor 702B on the right half 706 returning a higher reading than the sensor 702A on the left half 704. In one example, bidirectional Hall effect sensors are used for the sensors 702. Thus, by reading each sensor 702 separately and comparing the readings between them, the control logic 144 can determine that the right half 706 has insufficient contact to the workpiece 102. In an embodiment, the control logic 144 has a functional block for making such an evaluation and is implementable in hardware and microprocessor software. In one example, the control logic 144 determines that the right half 706 has insufficient contact when the difference between the readings of the sensor 702A and the sensor 702B exceeds a stored threshold amount. In another example, the control logic 144 determines that the right half 706 has insufficient contact when the difference between the readings of the sensor 702B and a known stored value is less than a threshold amount, the known stored value being determined during calibration of the magnetic coupling device 100.

[0095] In an embodiment, the control logic 144 is configured to determine whether the positioning of the left half 704 of the workpiece contact interface 104 and the right half 706 of the workpiece contact interface 104 relative to the ferromagnetic workpiece 102 is within a target zone 802 on the ferromagnetic workpiece 102 (see FIGS. 22-24). In one example, the positioning of the left half 704 of the workpiece contact interface 104 and the right half 706 of the workpiece contact interface 104 relative to the ferromagnetic workpiece 102 is determined by the control logic 144 to be within the target zone 802 (FIGS. 22-24) of the ferromagnetic workpiece 102 when the output of the first magnetic field sensor 702A meets a first criterion and the output of the second magnetic field sensor 702B meets a second criterion. An exemplary first criterion is that the output of the first magnetic field sensor 702A is within a first range of magnetic flux values ​​and an exemplary second criterion is that the output of the second magnetic field sensor 702B is within a second range of magnetic flux values.

[0096] 22-24, a target zone 802 is illustrated. The workpiece 102 is illustrated as a sheet of material having a right edge 804 and a left edge 806. The target zone 802 is a portion of the workpiece 102 between a first offset 808 from the right edge 804 of the workpiece 102 and a second offset 810 from the left edge 806 of the workpiece 102. In one example, as the magnetic coupling device 100 approaches and / or crosses the second offset 810, the leakage flux associated with the left half 704 of the workpiece contact interface 104 is higher than the leakage flux associated with the right half 706 of the workpiece contact interface 104 because the left half 704 of the workpiece contact interface 104 is closer to the left edge 806 of the workpiece 102. Similarly, as the device 100 approaches and / or exceeds the first offset 808, the leakage flux associated with the right half 706 of the workpiece contact interface 104 is higher than the leakage flux associated with the left half 704 of the workpiece contact interface 104 because the right half 706 of the workpiece contact interface 104 is closer to the right edge 804 of the workpiece 102. Although shown as a linear target zone 802, a two-dimensional target zone 802 may be defined relative to the length and width of the ferromagnetic workpiece 102. In one example, a calibration run is performed where the device 100 is placed at each of the first limit 808 (see FIG. 24) and the second limit 810 (see FIG. 23) and the corresponding leakage flux values ​​of the flux sensors 702A, 702B at both limits are stored in the memory 142. The two leakage flux values ​​stored for the first limit position (see FIG. 24) are stored in memory 142 as "limit position 1" (two values, one for each sensor 702A, 702B). The two leakage flux values ​​stored for the second limit position (see FIG. 23) are stored in memory 142 as "limit position 2" (two values, one for each sensor 702A, 702B). In an embodiment, the first range of the first criterion is between and including limit position 1 and limit position 2 for one of the magnetic field sensors 702A, 702B. and a second range of the second criterion is values ​​between and including limit position 1 and limit position 2 for the other of the magnetic field sensors 702A, 702B. Assuming the first range of values ​​corresponds to the left half 704 of the workpiece contact interface 104 and the second range of values ​​corresponds to the right half 706 of the workpiece contact interface 104, the control logic 144 determines that the left end of the magnetic coupling device 100 is located outside of the target zone 802 when the second criterion is met and the first criterion is not met, and similarly, determines that the right end of the magnetic coupling device 100 is located outside of the target zone 802 when the first criterion is met and the second criterion is not met.

[0097] In an embodiment, the use (storage) of the calibration values ​​of "Limit Position 1 and Limit Position 2" in the memory 142 allows the device user to calibrate the current signal of the ferromagnetic workpiece 102 to only be on when a particular magnetic actuation circuit is formed (if calibrated as the same position) or within the range of the magnetic actuation circuit (if calibrated as two different positions). The left half 704 and the right half 706 of the workpiece contact interface 104 can be equal to the "maximum leakage" position of limit position 1 / 2 or outside of it at a larger leakage position. These calibrations are what allow for so-called double blank detection (DBD) and part-specific or range-specific confirmation. The freedom of the left half 704 and the right half 706 of the workpiece contact interface 104 to be outside of the limit positions is intended to give the user more freedom, especially when they land near the edge of a thinner steel sheet.

[0098] In an embodiment, this multi-sensory approach can also be used to provide additional device status data. In the above situation, not only can the two sensor readings be compared to determine the general state of the magnetic coupling device 100 and the presence or absence of a ferromagnetic workpiece 104 near the workpiece contact interface 104, but more differentiated and accurate magnetic field measurements can be obtained from each sensor 702 when in close proximity to the ferromagnetic workpiece 102 (i.e., presence has already been detected, but proximity has not yet been quantified), and calculations can be made on the value of each sensor 702 signal and the difference value between the magnetometer readings to determine the orientation of the magnetic coupling device 100 relative to the ferromagnetic workpiece 102, such as at what angle the magnetic gripper containing the device 100 is sitting relative to the flat ferromagnetic workpiece 102.

[0099] Taking this a step further, by using calibration runs of the magnetic coupling device 100 with respect to a predefined ferromagnetic workpiece 102 having known parameters (size, shape, material, etc.) and storing in the memory 142 the evaluation circuit data obtained from processing the sensor 702 output signals during the various calibration runs, it is possible to completely determine the orientation and distance to the target surface of the ferromagnetic workpiece 102 relative to the position of the magnetic coupling device 100 even before the workpiece contact interface 104 contacts the ferromagnetic workpiece 102, especially if additional magnetic field sensors are placed in locations other than the previously specified locations as shown in FIG. 15. Since the magnetic coupling device 100 emits leakage flux in any state, even in the off state, a highly sensitive sensor can respond to small variations in leakage flux emanating from the pole plate 106 at the sensor detection surface in the off state. When the magnetic coupling device 100 in the off state or in a known partially on state approaches the ferromagnetic workpiece 102, then an appropriately sensitive magnetometer can deliver a signal that can indicate the proximity to the component and be converted into a control signal for the robot arm 600 that acts as a kind of "vision" for the otherwise blind robot. As another example, a suitably sensitive magnetometer could assist a robot arm 600 that can only determine its two-dimensional position by determining the distance between the magnetic coupling device 100 and the ferromagnetic workpiece 102 (e.g., the depth between the two). Thus, the robot arm 600 can move the magnetic coupling device 100 closer to the ferromagnetic workpiece 102 while avoiding collisions (e.g., For example, it can be programmed to slow down (directly or indirectly).

[0100] For example, assuming there are four magnetometers in total, one on the flux sensing surface of the left half side 704 of the workpiece contact interface 104, as discussed above, one on the flux sensing surface of the right half side 706 of the workpiece contact interface 104, and two additional sensors elsewhere as shown in FIG. 15 , as the magnetic coupling device 100 is moved toward the ferromagnetic workpiece 102, bringing one of the sensors 702 closer (in absolute terms) than the other sensors 702, the leakage magnetic flux lines near that sensor 702 will increase in density and focus toward the ferromagnetic workpiece 102. In moving the magnetic coupling device 100 closer to the ferromagnetic workpiece 102 (without changing the spatial orientation and translational direction of the magnetic coupling device 100 coupled to the end of the arm of the robot 600), the magnetic flux lines are redistributed more strongly across the magnetic coupling device 100, and the density of the magnetic flux lines on the nearest sensor 702 will be inversely proportional to the distance between the sensor 702 and the ferromagnetic workpiece 102. This produces a higher reading at the magnetometer above the proximity sensor 702. By comparing the output of the proximity magnetometer to the signal outputs from the other three magnetometers, and by evaluating the data, it can be known where and how close the ferromagnetic workpiece 102 is to the working surface of the magnetic coupling device 100, given the known spatial relationship between the sensor 702 and the working surface of the workpiece contact interface 104. As another example, one or more three-dimensional magnetometers can be used to determine how close the ferromagnetic workpiece 102 is to the working surface of the magnetic coupling device 100.

[0101] In performing precise calculations on the output of the magnetometers of the magnetic coupling device 100, other functions can be enabled when the magnetic flux source is turned on and contact is established with the ferromagnetic workpiece 102. There is a direct relationship between the amount of magnetic flux in the magnetic circuit during operation and the amount of physical force that the magnetic circuit during operation can withstand, which in the case of the magnetic coupling device 100 corresponds to the device's 100 payload. Because leakage flux from a permanent magnet depends on the amount of magnetic flux "consumed" (i.e., bound) in the primary actuation circuit, there is a correlation between leakage flux and the maximum payload that can be sustained by the magnetic coupling device 100. The processor 140 of the control logic 144, in one embodiment, can be programmed with appropriate equations to perform a calibration run so that the combined readings of the magnetometers on the magnetic coupling device 100 can be used to derive a more accurate holding force for the magnetic coupling device 100 than known devices. This can be used as a "safety check" to ensure that (i) the magnetic coupling device 100 can lift the ferromagnetic workpiece 102 before it is moved by the robot 600, (ii) the magnetic coupling device 100 is operating at full capacity, and / or (iii) the magnetic coupling device 100 is operating without damage or degradation. Additionally or alternatively, these methods can be used for part specific detection and / or detection of a range of thicknesses of the ferromagnetic workpiece 102.

[0102] In all of these situations, the processor 140 of the control logic 144 is responsible for accepting inputs from each of the magnetometers 702 of the magnetic coupling device 100 and performing calculations and comparisons. The processor 140 then determines various device states based on the calculations. In an embodiment, the device 100 communicates the determined device states and feedback points to a robotic controller (e.g., 136 in FIG. 14 ). This is processed by either the 24V I / O or communication module (not shown). Once the feedback is communicated to the robotic controller 136, the robotic controller 136 can then adjust the orientation and operation of the device 100 to address a challenge or problem during operation.

[0103] The control logic 144 is controlled by the on-board processor 140 of the magnetic coupling device 100. It will be appreciated that the present invention includes the components necessary to separate, filter and amplify the signals provided by the sensors for processing by the optical fiber optics.

[0104] Additional details and embodiments regarding sensing capabilities and sensor arrangements that may be incorporated into magnetic coupling device 100 are disclosed in PCT Patent Application No. PCT / US18 / 29786, filed April 27, 2018, entitled "MAGNETIC COUPLING DEVICE WITH AT LEAST ONE OF A SENSOR ARRANGEMENT AND A DEGAUSS CAPABILITY," the entire disclosure of which is expressly incorporated herein by reference.

[0105] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the above embodiments refer to certain 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 coupling device for magnetically coupling to a ferromagnetic workpiece, comprising: a housing having an axis extending between a first end of the housing and a second end of the housing; a piece of iron positioned at least a first distance from the second end of the housing; a magnetic platter supported by the housing, the magnetic platter including a plurality of permanent magnet portions interposed between a plurality of ferromagnetic pole piece portions; A magnetic coupling device, wherein the magnetic platter is linearly translatable within the housing along the axis to each of at least a first state and a second state, the magnetic platter is positioned adjacent to the ferrous piece such that when the magnetic platter is in the first state, the magnetic coupling device establishes a first magnetic circuit through the ferrous piece 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 ferrous piece 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 being a non-zero magnetic field strength.

2. The magnetic coupling device of claim 1 , further comprising at least one non-ferromagnetic piece disposed at least a second distance from the second end of the housing.

3. The magnetic coupling device of claim 1 , wherein the magnetic platters translate a distance of 8 mm or less.

4. The magnetic coupling device of claim 1 , wherein the magnetic coupling device provides a coercive force of 0.25 grams per cubic mm of the magnetic coupling device or greater.

5. The magnetic coupling device of claim 1 , wherein the magnetic coupling device provides a coercive force of at least 0.35 grams per cubic mm of the magnetic platter.

6. The magnetic coupling device of claim 1 , wherein the magnetic coupling device provides a retention force of at least 0.15 grams per square mm of the workpiece contact interface.

7. 2. The magnetic coupling device of claim 1, wherein the magnetic coupling device is linearly translatable to a third state, and the magnetic platter is disposed between the first state and the second state when the magnetic platter is in the third state.

8. The magnetic coupling device of claim 7 , wherein the housing comprises a brake configured to releasably hold the magnetic platter in the third state.

9. The magnetic coupling device of claim 1 , wherein the workpiece contact interface comprises a plurality of spaced apart protrusions.

10. The magnetic coupling device of claim 9 , wherein the workpiece contact interface is releasably supported by the housing.

11. The magnetic coupling device of claim 1 , wherein the magnetic platter is releasably supported by the housing.

12. 4. The method of claim 3, wherein the workpiece contact interface has a quadrilateral footprint.

2. The magnetic coupling device according to claim 1.

13. The magnetic coupling device of claim 12 , wherein the quadrilateral footprint is a rectangular footprint or a square footprint.

14. 10. The magnetic coupling device of claim 1, further comprising a sensing system supported by the housing, the sensing system including at least one sensor that monitors a level of magnetic flux available to the ferromagnetic workpiece at the workpiece contact interface.

15. The magnetic coupling device of claim 1 , further comprising an actuator configured to linearly translate the magnetic platter between the first state and the second state.

16. The magnetic device of claim 15 , wherein the actuator is at least one of a pneumatic actuator, a hydraulic actuator, and an electric actuator.

17. The magnetic coupling device of claim 1 , wherein the iron piece spans multiple pole piece portions and / or multiple permanent magnet portions.

18. 1. A method for coupling and decoupling a magnetic coupler to a ferromagnetic workpiece, the method comprising: contacting the ferromagnetic workpiece with a workpiece engaging interface of the magnetic coupler; moving a magnetic platter of the magnetic coupling device from a first separation from the workpiece engaging surface to a second separation from the workpiece engaging surface that is less than the first separation; moving the workpiece from a first position to a second position using the magnetic coupler; and moving the magnetic platter from the workpiece engaging surface to a third separation to disengage the magnetic coupler from the workpiece and form a magnetic circuit through an iron piece within the housing, the third separation being greater than the second separation.

19. 1. A magnetic coupling device for magnetically coupling to a ferromagnetic workpiece, comprising: a housing having a passageway defining a passageway axis; a magnetic platter supported by the housing, the magnetic platter movable between a first position and a second position along the passage axis, the magnetic platter including a plurality of permanent magnet portions interposed between a plurality of ferromagnetic pole piece portions; a workpiece contact interface supported by the housing and adapted to contact the ferromagnetic workpiece; and a magnetic shunt supported by the housing and magnetically accessible from the passageway, wherein with the magnetic platter in the first position a first magnetic circuit is formed with the magnetic platter and the magnetic shunt, and with the magnetic platter in the second position a second magnetic circuit is formed with the magnetic platter and the ferromagnetic workpiece through the workpiece interface.

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