Ultra-light and ultra-accurate portable coordinate measuring machine with reduced profile swivel joint

Abstract

A coordinate measuring machine (CMM) may include a manually positionable articulated arm including an arm segment and a swivel joint. The swivel joint may include two or more bearings, a shaft coupled to an inner race of the first bearing and an inner race of the second bearing, a first housing coupled to an outer race of the first bearing, and a second housing coupled to an outer race of the second bearing. The second housing is not directly connected to the first housing. The swivel joint may also include an inner spacer coupled to the inner race of the first bearing and the inner race of the second bearing and an outer spacer coupled to the outer race of the first bearing and the outer race of the second bearing. A majority of the outer surface of the outer spacer may be exposed to form part of the housing of the CMM.

Description

Background Art

[0001] The present disclosure relates generally to a coordinate measuring machine, and more particularly to a high accuracy, ultra-lightweight portable coordinate measuring machine.

[0002] Coordinate measuring machines are used in particular for measuring points in three-dimensional space. Coordinate measuring machines, for example, track measuring points in a Cartesian coordinate space (x, y, z). Coordinate measuring machines usually consist of a support and a tracking system. The support can serve as a reference point relative to which the tracking system moves in a measurable manner in space. The tracking system of a portable coordinate measuring machine may include an articulated arm attached to the support at one end and a measuring probe at the other end.

[0003] For a measurement to be useful, it must be accurate. However, due to factors such as temperature and load conditions, it is difficult to achieve very high accuracy. Particularly in portable coordinate measuring machines, deformation of the arm caused by thermal changes or by load changes has a negative impact on the accuracy of the measurement. Therefore, one of the reasons why conventional portable coordinate measuring machines lack accuracy in terms of their performance is that they lack rigidity.

[0004] Accuracy improvements can be made. However, traditionally, such improvements are accompanied by a significant increase in the mass and / or weight of the coordinate measuring machine. Conventional portable coordinate measuring machines with improved accuracy are bulky and heavy. These are undesirable characteristics for a coordinate measuring machine, especially a portable coordinate measuring machine. Furthermore, a method for constructing and assembling joints, especially long joints, for a coordinate measuring machine to have the required accuracy to obtain accurate measurements has not been achieved. Summary of the invention

[0005] The present disclosure provides a portable coordinate measuring machine (CMM) that is more accurate than prior art coordinate measuring machines. In particular, the CMM disclosed herein is also lighter and less bulky.

[0006] In one aspect of the present invention, the CMM disclosed herein includes a new type of swivel joint. The swivel joint may include spacers placed between bearings to maintain proper spacing between bearings, and more importantly to set and maintain preload, which improves stiffness, thereby improving measurement accuracy compared to deadweight preload or spring preload. The outer spacer may be arranged adjacent to the outer ring of the first bearing and the outer ring of the second bearing, and the inner spacer may be arranged adjacent to the inner ring of the first bearing and the inner ring of the second bearing. Most of the outer surface of the outer spacer may be exposed to represent the outermost layer of at least one of the swivel joints. That is, most of the outer surface of the outer spacer may be exposed to form part of the housing of the CMM. Compared with existing CMMs, the swivel joint disclosed herein is significantly smaller (because no additional housing components are required), lighter (easier to transport), and more aesthetically pleasing. This swivel joint design is also more rigid, which can reduce bending or deformation of the CMM, thereby improving the accuracy of the CMM.

[0007] The accompanying drawings that are incorporated in the specification and form a part of the specification illustrate various exemplary systems, methods, etc., which illustrate various exemplary embodiments of various aspects of the present invention. It should be understood that the element boundaries (e.g., boxes, frame groups, or other shapes) shown in the drawings represent an example of boundaries. It will be understood by those of ordinary skill in the art that an element can be designed as multiple elements, or multiple elements can be designed as one element. An element that is shown as an internal component of another element can be implemented as an external component, and vice versa. In addition, the elements may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figures 1A to 1C A perspective view of an exemplary coordinate measuring machine (CMM) is shown. Figure 1D Shows Figures 1A to 1C Cross-sectional view of an exemplary CMM.

[0009] Figure 2A and Figure 2B They are shown respectively Figures 1A to 1D Cross-sectional and partially exploded views of an exemplary swivel joint of a CMM.

[0010] Figure 3A and Figure 3B They are shown respectively Figures 1A to 1D Cross-sectional and partially exploded views of the hinge joint of the CMM.

[0011] Figure 4A and Figure 4B They are shown respectively Figures 1A to 1D Cross-sectional and partially exploded views of an exemplary base and swivel joint of a CMM.

[0012] FIG. 5A to FIG. 5C Shows Figures 1A to 1DCross-sectional and partially exploded views of an exemplary measurement probe for a CMM. DETAILED DESCRIPTION

[0013] Figures 1A to 1C A perspective view of an exemplary coordinate measuring machine (CMM) 1 is shown. Figure 1D A cross-sectional view of an exemplary CMM 1 is shown. The CMM 1 comprises an articulated arm 2, a base 4 and a measurement probe 6. The articulated arm 2 is attached to the base 4 at one end and to the measurement probe 6 at the other end. The base 4 may be attached to, for example, a base plate 5 to attach the arm 2 to, for example, a work surface. The articulated arm 2 comprises two arm segments 8, 9 and a plurality of rotation joints 12, 14, 16, 18, 20, 22, 24.

[0014] The overall length of the articulated arm 2 and / or arm segments 8, 9 can vary depending on their intended application. In one embodiment, the articulated arm can have an overall length of approximately 48 inches. Such arm dimensions provide a portable CMM that is well suited for measurements that are currently accomplished using common handheld tools (e.g., micrometers, height gauges, calipers, etc.). The articulated arm 2 can have smaller or larger dimensions.

[0015] The rotating joints generally include two types of joints, swivel joints 12, 16, 20 and hinge joints 14, 18, 22. The swivel joints 12, 16, 20 are generally located axially or longitudinally along the arm 2. The hinge joints 14, 18, 22 are generally located at 90° relative to the swivel joints or at 90° relative to the longitudinal axis of the arm 2. The swivel joints and hinge joints are generally as shown in FIG. Figures 1A-1D The arm 2 is manually positionable due to the multiple rotating joints, meaning that the user can freely manually move the probe 6 to almost any position within a radius centered at the base 4 of the CMM 1. Each of these joints is generally as shown in FIG. Figures 2A to 5C shown.

[0016] Typically, the base plate 5 of the base 4 attaches the CMM 1 to the work surface, the base 4 is attached to the swivel joint 12, the swivel joint 12 is attached to the hinge joint 14, the hinge joint 14 is attached to the swivel joint 16, the swivel joint 16 is attached to the hinge joint 18, the hinge joint 18 is attached to the swivel joint 20, the swivel joint 20 is attached to the hinge joint 22, and the hinge joint 22 is attached to the measuring probe 6.

[0017] Figure 2A A partial cross-sectional view of the swivel joint 16 is shown, Figure 2BA partially exploded view of an exemplary swivel joint 16 is shown. Each of the figures shows only the end of the swivel joint 16; the middle portion of the swivel joint, which is not shown, corresponds to the arm segment 8. Although the swivel joints can be different, the swivel joint 16 will be used herein to generally describe the swivel joints 12, 16, 20. The swivel joints 16 and 20 are very similar.

[0018] The swivel joint 16 may include a housing 48, a housing 49, a shaft 30, a bearing 32, a bearing 34, a spacer 301a, a spacer 301b, an encoder PCB 36, an encoder disk 38, and a slip ring 40. The bearings 32, 34 are preferably steel or stainless steel ball bearings. The relatively long shaft 30 may be made of a rigid but relatively light material, such as carbon fiber, aluminum, etc., as well as steel. In one embodiment, the shaft 30 may be made of steel or ceramic to match the material from which the bearings 32, 34 are made. Similar to the relatively long shaft 30, the spacers 301a and 301b may be tubes made of the same rigid but relatively light material as the shaft 30, including carbon fiber, ceramic, or steel.

[0019] At one end of the swivel joint 16, the housing 48 has a port in which the end of the shaft 30 is located and a yoke 48a that operably connects the swivel joint 16 to the previous hinge joint (see Figures 1A to 1D ). As for the swivel joint 16, the yoke 48a has two protrusions that connect the swivel joint 16 to the shaft of the hinge joint 14. At the other end of the swivel joint 16, the housing 49 has a port in which the end of the shaft 30 is located.

[0020] As in Figure 2A As best seen in FIG. 1 , at one end of the swivel joint 16, the inner diameter of a port of housing 48 engages (e.g., is fixedly attached to) the outer diameter or outer race of bearing 32. The port of housing 48 may, for example, be bonded to the outer diameter or outer race of bearing 32. Shaft 30 itself has an outer diameter that engages (e.g., is fixedly attached to) the inner diameter or inner race of bearing 32. Shaft 30 may, for example, be bonded to the inner diameter or inner race of bearing 32. At the other end of the swivel joint 16, the inner diameter of a port of housing 49 engages (e.g., is fixedly attached to) the outer diameter or outer race of bearing 34. The port of housing 49 may, for example, be bonded to the outer diameter or outer race of bearing 34. Shaft 30 itself has an outer diameter that engages (e.g., is fixedly attached to) the inner diameter or inner race of bearing 34. Shaft 30 may, for example, be bonded to the inner diameter or inner race of bearing 34. Thus, shaft 30 rotates about the axis of rotation a of bearings 32 and 34 and housings 48 and 49.

[0021] At least one converter is mounted on the PCB 36 of the swivel joint 16, and the converter is configured to output an angle signal corresponding to the rotation angle of the shaft 30 relative to the housing 48, 49 about the rotation axis α. Each converter includes an optical encoder having two main components (an encoder disk 38 and one or more read heads). The encoder disk 38 can be operably attached to the end of the shaft 30 spaced apart from and aligned with the read head on the PCB 36 (for example, using a suitable adhesive), and the read head on the PCB 36 is operably attached to the housing 48 (for example, using fasteners and / or suitable adhesive). The positions of the disk 38 and the read head can be reversed, whereby the disk 38 can be operably attached to the housing 48, and the read head rotates with the shaft 30 so as to be rotatable relative to each other while maintaining optical communication. Encoders are commercially available, such as purchased from CeleraMotion under the trade name of, for example, MicroE encoders. Each PCB 36 may additionally include a processor for receiving an angle signal from the read head, and a connector and transceiver for connecting the PCB 36 to the communication bus and / or other wiring of the CMM 1. Each of the PCBs 36 may also include a temperature sensor connected to the processor to provide thermal compensation based on room temperature variations.

[0022] A Kapton film 306 may be located between the PCB 36 and the housing 48 for electrical isolation. A plastic cap 307 may be bonded to the center hole of the PCB 36 to seal the cavity between the PCB 36 and the encoder disk 38 from dust contamination.

[0023] The cover 82 is operably connected to the housing 48 to cover the wiring harness and seal the PCB 36 and the encoder disk 38 from dust. The cover 82 can be divided into two parts 82a and 82b, which are combined and operably attached to the housing 48. A portion of the cover portion 82b covers a portion of the yoke 48a that protrudes to operably connect the swivel joint 16 to the hinge joint 14.

[0024] The swivel joint 16 (as well as other joints in the CMM 1) can rotate without restriction, which means that it can rotate 360° around its rotation axis α. Therefore, a slip ring 40 is used and provides an unlimited rotatable electrical connection to the swivel joint 16. Here, the shafts used in the swivel joints (such as the shaft 30 of the base swivel joint 12 and the shaft 30 of the swivel joint 16) can be hollow (i.e., have an axial opening). In this context, the shafts used in the hinge joints (such as the shaft 80 of the hinge joint 18 described below) can also be hollow and can also include holes (see Figure 3A ).

[0025] according to Figures 1A to 1DIt is understood that the swivel joint 16 of the arm section 8 is a relatively long joint. In one embodiment, the shaft 30 is at least 6 inches long. Such a long joint is usually problematic because, as explained in detail in U.S. Patent No. 10,267,614 (incorporated herein by reference in its entirety), improved precision requires concentricity between the bearing holes of the housing 48 and the housing 49. The prior art (e.g., see U.S. Patent No. 10,267,614, FIG. 3C) uses special fixtures to align these holes to improve concentricity. This process is cumbersome and leaves room for further improvement of concentricity. Moreover, the prior art (e.g., see U.S. Patent No. 10,267,614, FIG. 3E) applies bearing preload using deadweight or spring washers, which also leaves room for further improvement. The swivel joint 16 uses a novel and unique construction that solves these problems.

[0026] The swivel joint 16 may include spacers 301a and 301b, which, due to the unique construction of the swivel joint 16, may play a dual role: as spacers (responsible for maintaining the proper distance and preload between bearings 32, 34) and as the shell or outermost layer of the CMM 1. The unique design solves the concentricity problem in the prior art because the design provides a rigid and concentric swivel joint bearing assembly with bearings 32, 34 and spacers 301. The unique design involving spacers 301 also provides improvements in bearing preload.

[0027] In the illustrated embodiment, the inner spacer 301a is a tubular spacer disposed adjacent to the inner ring of the first bearing 32 and the inner ring of the second bearing 34, and the outer spacer 301b is a tubular spacer disposed adjacent to the outer ring of the first bearing 32 and the outer ring of the second bearing 34. The spacers 301a and 301b are matched and precisely ground to maximize the accuracy of the structure formed by the spacers 301a, 301b and the bearings 32 and 34. In addition, as shown in FIG. Figure 2A As shown, most of the outer surface of the outer spacer 301b is exposed (ie there is no additional coating on the spacer 301b), and therefore the outer surface of the outer spacer 301b is the outermost layer of the swivel joint 16. This means that the outer surface of the outer spacer 301b forms part of the CMM 1 housing.

[0028] Since the outer surface of the outer spacer 301b forms part of the housing of the CMM 1, no additional fixtures are required. In addition, compared to conventional CMMs, the spacers 301a and 301b increase the stiffness of the swivel joint bearing assembly of the CMM 1, which reduces bending / bending and therefore improves stiffness and ultimately accuracy. In part, due to this unique design, the CMM 1 achieves significantly better accuracy than prior art portable coordinate measuring machines.

[0029] Figure 3A shows a cross-sectional view of the hinge joint 18, Figure 3B An exploded view of an exemplary hinge joint 18 is shown. The hinge joint 18 will be used herein to generally describe the hinge joints 14, 18, 22. At least some components of the hinge joint 18 are substantially similar to the components discussed in detail above with reference to the swivel joints 12 and 16, and thus these similar components are not necessarily identical. Figure 3A and Figure 3B The same reference numerals as in the previous figures are used to identify the components.

[0030] The hinge joint 18 may include a housing 78, a shaft 80, a bearing 32, a bearing 34, a spacer 301a, a spacer 301b, an encoder PCB 36, and an encoder disk 38. Figure 3A As best shown in FIG. 1 , the housing 78 has a port that engages (e.g., is securely attached to) the outer diameter or outer race of the bearings 32, 34. The port of the housing 78 can, for example, be bonded to the outer diameter or outer race of the bearings 32 and 34. The shaft 80 itself has an outer diameter that engages (e.g., is securely attached to) the inner diameter or inner race of the bearings 32, 34. The shaft 80 can, for example, be bonded to the inner diameter or inner race of the bearings 32, 34. Thus, the shaft 80 rotates about the rotation axis b of the housing 78 and the bearings 32, 34 of the hinge joint 18.

[0031] The spacers 301a and 301b may be tubes made of a material that is as rigid as the shaft 80 but relatively light, including carbon fiber, ceramic, or steel. The spacers 301a and 301b may be placed between the bearings 32 and 34 to maintain proper spacing between the bearings 32 and 34, and more importantly to set and maintain preload. In the illustrated embodiment, the inner spacer 301a is a tubular spacer disposed adjacent to the inner race of the first bearing 32 and the inner race of the second bearing 34, and the outer spacer 301b is a tubular spacer disposed adjacent to the outer race of the first bearing 32 and the outer race of the second bearing 34. The spacers 301a and 301b are matched and precisely ground to maximize the accuracy of the structure formed by the spacers 301a, 301b and the bearings 32 and 34.

[0032] The shaft 80 is configured to engage with the yoke of an adjacent swivel joint (e.g., yoke 48a of swivel joint 20). In the illustrated embodiment, the shaft 80 has a groove 72 formed on the shaft 80 by machining or other means to create a gap (e.g., 5 mils or 127 µm) to better bond the adhesive to the yoke of the adjacent swivel joint (e.g., yoke 48a of swivel joint 16). The housing 78 has a housing bracket 78a built or welded or otherwise mounted on the housing 78, and the housing bracket 78a creates a gap 79 in the housing 78 for engaging one of the protrusions of the yoke with the shaft 80 so that the two protrusions of the yoke straddle the bearings 32, 34 between the two protrusions.

[0033] The encoder cavity dust sealing gasket 302 is held in place by the inside of the bracket 78a and a gasket 303 bonded to the shaft 80. A plastic cap 307 is bonded to the center hole of the encoder plate 36. The dust sealing gasket 302 and plastic cap 307 seal the encoder cavity (inside the bracket 78a) from dust contamination from either end.

[0034] Similar to the swivel joint discussed above, the PCB 36 of the hinge joint 18 has mounted thereon at least one transducer configured to output an angular signal corresponding to the angle of rotation of the shaft 80 relative to the housing 78 about the rotation axis b. As described above, each transducer includes an optical encoder having two major components, an encoder disk 38 and one or more read heads. In the illustrated embodiment, the encoder disk 38 is operably attached to an end of the shaft 80 spaced apart from and aligned with the read heads on the PCB 36, which are operably attached to the housing 78 (e.g., using fasteners and / or a suitable adhesive). The positions of the disk 38 and read heads may be reversed, whereby the disk 38 may be operably attached to the housing 78 and the read heads rotated with the shaft 80 so as to be rotatable relative to each other while maintaining optical communication. As shown in Figure 3A As best shown in FIG. 16A , the PCB 36 and encoder disk 38 are located adjacent one end of a shaft 80 separated from the bearing 34 by a gap 79. This differs from previous hinge joints in which the PCB 36 and encoder disk 38 may be located between the ends of the shaft 80, between the bearings 32 and 34 (see, e.g., U.S. Patent No. 11,287,241, FIG. 16D ). In the illustrated embodiment, the PCB 36 and encoder disk 38 are located outside of the yoke of the adjacent swivel joint, rather than between the bearings 32 and 34, and are spaced from the bearing 34 by a gap 79 for one of the protrusions of the yoke to engage the shaft 80.

[0035] The PCB 36 and encoder disk 38 are located near one end of the shaft 80, rather than between the bearings 32 and 34 within the housing 78, which may expose the encoder disk 38, the read head, etc. to external loads, for example, a user may place his hand on the connector 18, especially on the plastic cover 82. This may introduce angle measurement errors. To prevent such external loads, the connector 18 may also include a bracket 305, which may be made of aluminum, steel, etc. and mounted to the housing 78. Figure 3B As shown, threaded holes 78b may be formed on the housing 78 to match the holes in the protector bracket 305 so that the bracket 305 may be mounted to the housing 78 using screws. Figure 3A As shown, the bracket 305 protects the PCB 36 and the encoder disk 38 from external loads. The connector 18 may also include a cover 82 that is operably attached to the housing 78 to cover the wiring harness and seal the PCB 36 and the encoder disk 38 from dust. Threaded holes may be formed on the cover 82 to match threaded holes in the bracket 305 to attach the cover 82 to the bracket 305 using screws.

[0036] Unlike prior art hinge joints, in which electronic components are buried within structural elements of the CMM joint (e.g., see U.S. Patent No. 11,287,241, FIG. 16D ), the hinge joint 18, in particular the PCB 36 and other electronic components (e.g., wiring harnesses) can be easily serviced by removing the cover 82. Compared to prior art CMMs, the hinge joint 18 is significantly smaller (because no space is required between the bearings 32 and 34 to accommodate the encoder PCB 36), lighter, easier to transport, and more aesthetically pleasing. Compared to prior art (e.g., see U.S. Patent No. 10,267,614, Figure 5B ), this design allows the use of spacers 301 in the hinge joint 18, whereas in the prior art the applied bearing preload force deforms the yoke and misaligns the outer rings of the bearings 32 and 34. The hinge joint 18 is therefore more rigid, which can reduce bending or deformation, thereby improving the measurement accuracy of the CMM.

[0037] Figure 4A and Figure 4BA cross-sectional view and exploded view of an exemplary joint 12 and substrate 204 are shown. The substrate 204 may have holes 208 formed therein that accommodate fasteners or magnetic plates for mounting the CMM 1 to a mounting surface. The main PCB 158 may be placed inside the substrate 204. The substrate 204 may have a cover plate 210 attached to the substrate 204 to cover the opening of the cavity where the PCB 158 is located. For example, the cover plate 210 may be fastened to the substrate 204 using screws 212. The main PCB may also be mounted to the cover plate 210 or to the substrate 204 using screws. An insulating member 306 (e.g., a Kapton film) may be arranged between the PCB 158 and the cover plate 210.

[0038] The rotary joint 12 may include a housing 28, a shaft 30, a bearing 32, a bearing 34, a spacer 301a, a spacer 301b, an encoder printed circuit board 36, an encoder disk 38, and a slip ring 40. The shaft 30 may have an internal opening 30a (e.g., 0.5" or 12.7 mm in diameter) to accommodate the slip ring 40. A plastic cap 307 is bonded to the center hole of the encoder PCB 36 to seal the encoder cavity from dust contamination. As shown in Figure 4A As best shown, the housing 28 has a port that engages (e.g., fixedly connects) the outer diameter or outer race of the bearings 32 and 34. For example, the port of the housing 28 can be bonded to the outer diameter or outer race of the bearings 32 and 34. For its part, the shaft 30 has an outer diameter that engages (e.g., fixedly connects) the inner diameter or inner race of the bearings 32 and 34. For example, the shaft 30 can be bonded to the inner diameter or inner race of the bearings 32 and 34. Thus, the shaft 30 rotates about the rotation axis c of the housing 28 and the bearings 32 and 34 of the hinge joint 12.

[0039] In the illustrated embodiment, the inner spacer 301a is a tubular spacer disposed adjacent to the inner race of the first bearing 32 and the inner race of the second bearing 34, and the outer spacer 301b is a tubular spacer disposed adjacent to the outer race of the first bearing 32 and the outer race of the second bearing 34. The spacers 301a and 301b are matched and precisely ground to maximize the accuracy of the structure formed by the spacers 301a, 301b and the bearings 32, 34. The spacers 301a and 301b can be tubes made of a material that is as rigid as the shaft 30 but relatively light, including carbon fiber, ceramic, or steel. The spacers 301a, 301b can be placed between the bearings 32 and 34 to maintain the proper spacing between the bearings 32 and 34, and more importantly to set and maintain the preload.

[0040] Similar to the swivel joint discussed above, the PCB 36 of the swivel joint 12 has at least one converter mounted thereon, which is configured to output an angle signal corresponding to the rotation angle of the shaft 30 relative to the housing 28 about the rotation axis c. The encoder PCB 36 and the encoder disk 38 can be accommodated in a cavity of the substrate 204 parallel to the main PCB 158. This arrangement is particularly space-saving and compact. The taller components on the main PCB 158 can be placed near the edge of the main PCB 158 with a larger height (not overlapping with the encoder PCB 36 in the vertical direction).

[0041] FIG. 5A to FIG. 5C 1 shows a cross-sectional view and an exploded view of an exemplary measurement probe 6. The probe 6 includes a housing 126 having an interior space for accommodating a PCB 130 and a handle 128 (formed by two parts 128a and 128b) having an interior space for accommodating a PCB 125. The housing 126 is operably coupled to the hinge joint 22 (see FIG. 1 ) by means of a yoke 126a. Figures 1A to 1D ).

[0042] The measurement probe 6 may also include a contact trigger probe 308 that is mechanically connected to the housing 126 (e.g., screwed to the housing 126) and electrically connected to the PCB 130. The handle 128 may include two switches, namely an execution switch 131 and a confirmation switch 132. The operator may use the switches to perform measurements (execution switch 131) and confirm measurements (confirmation switch 132) during operation. The handle 128 is generally shaped to resemble a human grip, which is more ergonomic than at least some prior art probes. The handle 128 may also accommodate a switch PCB 134 to which the switches 131 and 132 may be mounted. The switch PCB 134 is electrically coupled to the PCB 125 host component to process signals from the switches 131 and 132. In one embodiment, the PCB 125 includes a wireless (e.g., Wi-Fi, Bluetooth, etc.) transmitter (rather than being electrically connected to the communication bus of the CMM 1), which wirelessly transmits the execution and confirmation signals associated with the switches 131 and 132 to, for example, a host PC that typically controls the CMM 1. Wireless transmission of the execution and confirmation signals associated with switches 131 and 132 significantly simplifies the construction and wiring of probe 6. Probe 6 may also include a battery 309 for powering the electronics therein.

[0043] The handle 128 is attached to an aluminum block 311 and contains two plastic bearings 310 that rotate about the housing 126. A tactile feedback motor 312 is bonded into the handle 128 to provide feedback to the operator when taking measurements.

[0044] definition The following includes definitions of selected terms used herein. The definitions include various examples or forms of components that fall within the scope of the terms and can be used for implementation. The examples are not intended to be limiting. Both singular and plural forms of the terms may be within the definitions.

[0045] As used herein, an "operably connected" or "operably coupled", or a connection in which entities are "operably connected" or "operably coupled", refers to connecting entities so that the entities can be performed as expected. An operable connection can be a direct connection or an indirect connection, wherein intermediate entities cooperate or are otherwise part of the connection or between operably connected entities. In the case of signals, an "operably connected", or a connection in which entities are "operably connected", refers to a connection in which signals can be sent or received, physical communications, or logical communications. Typically, an operable connection includes a physical interface, an electrical interface, or a data interface, but it should be noted that an operable connection may include different combinations of these or other types of connections sufficient to allow operable control. For example, two entities can be operably connected by being able to communicate signals to each other directly or via one or more intermediate entities (e.g., a processor, an operating system, a logic component, software, or other entity). A logical or physical communication channel can be used to create an operable connection.

[0046] As used herein, a "signal" includes, but is not limited to, one or more electrical or optical signals, analog or digital signals, data, one or more computer or processor instructions, message, bit or bit stream, or other means capable of being received, transmitted, or detected.

[0047] With respect to the terms "having" or "including" used in the specification or claims, they are intended to be inclusive, similar to the term "comprising," which is interpreted as a transitional word when used in a claim. In addition, with respect to the term "or" (e.g., A or B) used in the specification or claims, it is intended to mean "A or B or both." When the applicant intends to mean "only A or B but not both," the term "only A or B but not both" is used. Therefore, the term "or" as used herein is inclusive, not exclusive. See "A Dictionary of Modern Legal Usage 624 (2nd ed. 1995)" by Bryan A. Garner.

[0048] Although example systems, methods, etc. have been described by way of example, and although the examples have been described in considerable detail, the applicant does not intend to limit the scope to or in any way to the detailed description made. Of course, in order to describe the systems, methods, etc. described herein, it is not possible to describe every possible combination of components or methods. Other advantages and modifications will be apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described. Therefore, the present application is intended to cover changes, modifications, and variations that fall within the scope of the appended claims. In addition, the foregoing description is not meant to limit the scope of the present invention. The scope of the present invention is determined by the appended claims and their equivalents.

Claims

1. A coordinate measuring machine (CMM), comprising: a manually positionable articulated arm having a first end and a second end, the articulated arm comprising a plurality of arm segments and a plurality of rotational joints including swivel joints and hinge joints, the first end comprising a connector configured to connect to a measurement probe, and the second end comprising a base for mounting the CMM to a mounting surface; Wherein, at least one of the swivel joints of the plurality of rotating joints comprises: a first bearing and a second bearing; a shaft at least six inches long and engaging an inner race of the first bearing and an inner race of the second bearing, the shaft being configured to rotate about an axis of rotation of the first bearing and the second bearing; a housing, the housing being engaged with an outer ring of the first bearing; at least one converter configured to output an angle signal corresponding to an angle of rotation of the shaft relative to the housing about the rotation axis, the at least one converter being arranged adjacent to one of the two ends of the shaft and not between the first bearing and the second bearing; and A matching set of inner and outer tubular spacers, the matching set of inner and outer tubular spacers including an outer tubular spacer disposed adjacent to the outer race of the first bearing and the outer race of the second bearing, and an inner tubular spacer disposed adjacent to the inner race of the first bearing and the inner race of the second bearing, a majority of the outer surface of the outer tubular spacer being exposed to represent the outermost layer of at least one of the swivel joints.

2. The CMM of claim 1, at least one of the swivel joints comprising: A second housing is engaged with the outer race of the second bearing, the second housing not being directly connected to the first housing.

3. The CMM of claim 2, wherein: Each of the first housing and the second housing extends axially along a longitudinal axis parallel to the rotational axis.

4. The CMM of claim 3, wherein: The axial length of each of the first shell and the second shell is such that the first shell and the second shell do not cover a majority of the outer surface of the outer tubular spacer.

5. The CMM of claim 4, wherein: The first shell and the second shell are respectively adhesively coupled to the outer surface of the outer tubular spacer.

6. The CMM of claim 1, wherein: The inner tubular spacer is adhesively coupled to the shaft.

7. The CMM of claim 1, wherein: A large portion of the outer surface of the outer spacer is exposed to form part of the housing of the CMM.

8. A coordinate measuring machine (CMM), comprising: a manually positionable articulated arm having a first end and a second end, the articulated arm comprising a plurality of arm segments and a plurality of rotational joints, the first end comprising a connector configured to connect to a measurement probe, and the second end comprising a base for mounting the CMM to a mounting surface; Wherein, at least one of the plurality of rotating joints is a swivel joint, and the swivel joint comprises: a first bearing and a second bearing; a shaft at least six inches long and coupled to the inner race of the first bearing and the inner race of the second bearing for rotation about an axis of rotation of the first bearing and the second bearing; a housing for accommodating the first bearing; at least one converter configured to output an angle signal corresponding to an angle of rotation of the shaft relative to the housing about a rotation axis; and An outer spacer is arranged adjacent to the outer ring of the first bearing and the outer ring of the second bearing, and an inner spacer is arranged adjacent to the inner ring of the first bearing and the inner ring of the second bearing, and most of the outer surface of the outer spacer is exposed to form a part of the housing of the CMM.

9. The CMM of claim 8, wherein the swivel joint comprises: A second housing accommodates the second bearing, the second housing not being directly connected to the first housing.

10. The CMM of claim 9, wherein: Each of the first housing and the second housing extends axially along a longitudinal axis that is parallel to the rotational axis.

11. The CMM of claim 10, wherein: The axial length of each of the first shell and the second shell is such that the first shell and the second shell do not cover a majority of the outer surface of the outer spacer.

12. The CMM of claim 10, wherein: The first shell and the second shell are respectively adhesively coupled to outer surfaces of the outer spacer.

13. The CMM of claim 8, wherein: The inner spacer is adhesively coupled to the shaft.

14. The CMM of claim 8, a majority of the outer surface of the outer tubular spacer being exposed to represent the outermost layer of at least one of the swivel joints.

15. A coordinate measuring machine (CMM), comprising: a manually positionable articulated arm having a first end and a second end, the articulated arm comprising a plurality of arm segments and a plurality of rotational joints including swivel joints and hinge joints, the first end comprising a connector configured to connect to a measurement probe, and the second end comprising a base for mounting the CMM to a mounting surface; Wherein, at least one of the swivel joints of the plurality of rotating joints comprises: a first bearing and a second bearing; a shaft coupled to the inner race of the first bearing and the inner race of the second bearing to rotate about a rotation axis of the first bearing and the second bearing; a first housing coupled to an outer race of the first bearing and a second housing coupled to an outer race of the second bearing, the second housing not directly connected to the first housing; at least one converter configured to output an angle signal corresponding to an angle of rotation of the shaft relative to the first housing about the rotation axis; and An inner spacer coupled to the inner ring of the first bearing and the inner ring of the second bearing, and an outer spacer coupled to the outer ring of the first bearing and the outer ring of the second bearing, most of the outer surface of the outer spacer is exposed to form a part of the housing of the CMM.

16. The CMM of claim 15, wherein: Each of the first housing and the second housing extends axially along a longitudinal axis parallel to the rotational axis.

17. The CMM of claim 16, wherein: The axial length of each of the first shell and the second shell is such that the first shell and the second shell do not cover a majority of the outer surface of the outer spacer.

18. The CMM of claim 17, wherein: The first shell and the second shell are respectively adhesively coupled to outer surfaces of the outer spacer.

19. The CMM of claim 15, wherein: The inner spacer is adhesively coupled to the shaft.

20. The CMM of claim 15, a majority of the outer surface of the outer tubular spacer being exposed to represent the outermost layer of at least one of the swivel joints.

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