Pin clamp

A pin clamp assembly is provided which includes a housing, a locating pin, a body, a twist pin, and a cam pin. The locating pin extends from the body. Both the body and the locating pin include longitudinally extending cavities contiguously disposed therein. The body also includes longitudinally extending and opposed slots, each disposed from opposed exterior surfaces of the body and into the cavity. At least a portion of the locating pin and the body is located in a bore disposed through the housing. The twist pin is disposed in the longitudinally extending cavities of the locating pin and body. The twist pin includes a longitudinally extending cavity disposed therein, and longitudinally extending and opposed cam slots disposed from opposed exterior surfaces of the twist pin and into the cavity therein. The cam pin is coupled to the housing within the bore and extending there across. The cam pin is also disposed through the opposed slots and cavity in the body located within the bore of the housing, and disposed through the opposed cam slots and cavity of the twist pin.

TECHNICAL FIELD

The present disclosure is generally related to gripper or clamp assemblies, and more specifically, the present disclosure is related to pin clamps that can selectively grip a work piece.

BACKGROUND AND SUMMARY

Pin clamps which use movable locating pins to engage and grip a work piece are known. Characteristically, such pin clamps employ a reciprocally or rectilinearly moving locating pin with a movable finger or fingers positioned therein. The locating pin extends to engage a hole in a work piece such as a metal sheet. The locating pin then retracts causing the finger or fingers within the locating pin to extend and hold the work piece. Conventional pin clamps include an assembly of complicated cams, cam pins, slots, and finger mechanisms in order to accomplish this task. Some clamps use multiple cam followers or cam slots within their twist pin to move the fingers. This design requires specially made cam followers which limit available tolerances in the twist pin and in the over all design. In addition, using a single dowel in contrast to a plurality of cam followers in the twist pin, for example, is advantageous because the dowel can rotate reducing wear on the cams. Also, a single, inexpensive dowel can provide precise alignment within the single bore without fasteners being required, and removing the single dowel allows the pin to be disassembled without a complicated procedure.

Moreover, complicated pin clamp designs prevent the pin clamp from becoming adaptable to achieve additional functions useful on an assembly line. For example, unlocking mechanisms on a pin clamp when fluid power is lost can be useful in servicing applications on the assembly line. Adjustable collars or shrouds that adapt to the particular shape or thickness about the work piece can also be useful to prevent debris from contaminating the movable locating pin.

Accordingly, an illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises, a housing, a locating pin, a body, a twist pin, and a single cam pin. The body extends from the locating pin. Both the body and the locating pin include longitudinally extending cavities contiguously disposed therein. The body also includes longitudinally extending and opposed slots, each disposed from opposed exterior surfaces of the body and into the cavity. At least a portion of the locating pin and the body is located in a bore disposed through the housing. The twist pin is disposed in the longitudinally extending cavities of the locating pin and body. The twist pin includes a longitudinally extending cavity disposed therein, and longitudinally extending and opposed cam slots disposed from opposed exterior surfaces of the twist pin and into the cavity therein. The single cam pin is coupled to the housing within the bore and extending there across. The single cam pin is also disposed through the opposed slots and cavity in the body located within the bore of the housing, and disposed through the opposed cam slots and cavity of the twist pin.

In the above and other illustrative embodiments, the pin clamp assembly may further comprise: an actuator that moves the body and the twist pin in linearly reciprocal directions, causing the slots of the body to move with respect to the cam pin, causing the cam pin to move with respect to the cam slots causing the twist pin to rotate about an axis located perpendicular to the cam pin; the actuator being pneumatic; an electrically driven actuator that drives at least one carrier that drives a rod in communication with the body that moves the body and the twist pin in linearly reciprocal directions, causing the slots of the body to move with respect to the cam pin causing the cam pin to move with respect to the cam slots causing the twist pin to rotate about an axis located perpendicular to the cam pin; a locking mechanism that selectively restricts movement of the body; the locking mechanism comprising a first wedging surface located on the body, a second wedging surface located opposite the first wedging surface, a wedge member, and a bias member, wherein the wedge member engages the first and second wedging surfaces and is held by the bias; the locking mechanism preventing movement of the locating pin in one direction while allowing movement of the locating pin in an opposite direction; a sleeve located exterior of the housing and collaring a portion of the locating pin which also extends exterior of the housing; at least one shim located between the housing and the sleeve to increase the amount of collaring of the locating pin by the sleeve; and the shim being a plurality of shims to vary the mount of collaring of the locating pin by the sleeve.

Another illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises a housing, a locating pin, an actuator and a locating mechanism. The housing forms an internal cavity and an opening from said cavity to the exterior of said housing. The locating pin is disposed in the cavity and extends out of the opening to a distal end. The actuator moves the locating pin into and out of the opening. The locking mechanism selectively restricts movement of the locating pin.

In the above and other illustrative embodiments, the pin clamp assembly may further comprise: the locking mechanism comprising a first wedging surface located on the locating pin, a second wedging surface located opposite the first wedging surface, a wedge member, and a bias member, wherein the wedge member engages the first and second wedging surfaces and is held by the bias; the locking mechanism preventing movement of the locating pin in one direction while allowing movement of the locating pin in an opposite direction; a sleeve located exterior of the housing and collaring a portion of the locating pin which extends exterior of the housing; at least one shim located between the housing and the sleeve to increase the amount of collaring of the locating pin by the sleeve; and the shim being a plurality of shims to vary the mount of collaring of the locating pin by the sleeve.

Another illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises a body, a locating pin, fingers, a sleeve and at least one shim. The housing has a bore disposed therethrough. A portion of the locating pin is located interior of the housing and another portion extends exterior of the housing. The fingers selectively extend and retract from the locating pin exterior of the housing. The sleeve is located exterior of the housing and shrouds the portion of the locating pin that extends exterior of the housing. The shim is located between the sleeve and the housing to affect the amount of the locating pin is shrouded.

Additional features and advantages of the pin clamp will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the pin clamp as presently perceived.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the pin clamp, and such exemplification is not to be construed as limiting the scope of the pin clamp in any manner.

DETAILED DESCRIPTION OF THE DRAWINGS

A perspective view of an illustrative embodiment of pin clamp2is shown inFIG. 1. Pin clamp2illustratively comprises a housing4with a locating pin6extending therefrom. Fingers8are configured to selectively extend and retract from locating pin6. For example, when the locating pin6is retracted (as shown), fingers8are moved to the extended position (also as shown). Conversely, when locating pin6is extended upwardly, fingers8are retracted. (See, e.g.,FIG. 4a.) Accordingly, pin clamp2has the ability to extend the locating pin6through a bore in a work piece and then retract and use the fingers to hold the work piece against plate surface10. Also shown in this view is cover plate12illustratively attached to housing4via fasteners14. This plate allows access to the interior of housing4without having to disassemble the pin clamp assembly2. A secondary cover16is attached to cover plate12via fastener18. This allows selective access to the interior of housing4, as well. In one illustrative embodiment, the access is to unlock mechanism20. (See e.g.FIGS. 5a, band6.) This illustrative embodiment also shows fluid ports22,24. In this illustrative embodiment pneumatic pressure is supplied to fluid port22which causes the locating pin6to retract. Conversely, pneumatic fluid supplied to port24causes locating pin6to extend. It is appreciated that in alternative embodiments other power sources may be employed. For example, electrical power (seeFIGS. 9–11), as well as hydraulic fluid power, may be used in place of pneumatic power.

An exploded view of pin clamp assembly2is shown inFIG. 2. As shown herein, housing4is configured to receive pneumatic power supply26. Power supply assembly26comprises a piston28that receives a piston rod30which are illustratively fastened together via fastener32. Seals34,36, and38are configured to maintain a pressurized system. End cap40is configured to cover the bore42disposed in housing4and is secured thereon by a retaining ring44. (See alsoFIG. 3a.) Collar46is disposed about piston rod30to provide a bearing surface between seals36,38.

A locating pin assembly48comprises locating pin6with a body50depending therefrom. Fingers8are shown to be insertable into cavity52. In this illustrative embodiment, body50and locating pin6share a hollow interior that is configured to receive twist pin54. Pins56are located at the end of twist pin54and are configured to engage fingers8such that as twist pin54is caused to rotate, pins56engage respective fingers8to extend or retract them as desired. Twist pin54also includes a cam slot58that extends the entire diameter of twist pin54so that a single dowel or cam pin60can be disposed completely through twist pin54to allow travel of same along the path of cam slot58. Wiper seal62is located within bore64of housing4and is engageable with the body50of locating pin6to prevent contaminants from damaging the same. (See, also,FIG. 8d.) A dowel pin66is configured to be disposed through body50, as well as disposed through slot68of piston rod30. In one illustrative embodiment, slot68is elongated so that locating pin6can have independent movement of pneumatic power supply26. In this illustrative embodiment such independent movement is useful for locking, and particularly unlocking mechanism20. Also included in body50is slot70configured to receive cam pin60that is also disposed through cam slot58.

A collar72is disposed in bore64. Shims74are placed on the top76of housing4and are used as spacers to adjust the height of sleeve78, which has a bore79that locating pin6is to extend through to the exterior of housing4. Fasteners80can be used to attach sleeve and shim assembly to housing4.

A cavity82is also disposed into housing4and is configured to receive portions of unlocking mechanism20. Unlocking mechanism20comprises plate84which is attached to the interior of cavity82via fasteners86. Spring holder88is fastened to body50via fastener90and includes an illustrative pin92that is configured to be disposed through slot96of plate94and engage a switch target98. An illustrative lever100is configured to be disposed through opening102in plate94and selectively engage spring holder88. In this illustrative embodiment, lever100is configured to pivot at pivot point104to selectively unlock fingers8. It is appreciated that in alternative embodiments lever100can be replaced with other structures or mechanisms to unlock fingers8. Also shown are lock release106, pin108, and pin110. Further shown in this illustrative embodiment is an amplifier box111that is used to assist in detecting switch target.

A cross-sectional view of pin clamp2is shown inFIG. 3a. This view shows the connection between the several structures within pin clamp2. Specifically, piston28of pneumatic supply assembly26is shown located within bore42which is capped by end cap40, retaining ring44, and sealed with seal34. Fastener32is shown attaching piston28to piston rod30with seal36located there between. Also shown in this view are seals112,114which bound piston28.

Piston rod30extends through bore116and into cavity82. It is appreciated from this view how collar46may serve as a bearing surface for piston rod30and seal38separates cavity82from bore42. Illustratively within cavity82, piston rod30is coupled to body50of locating pin6via pin110which is disposed through bore118in body50and extends through slot68of piston rod30. In this illustrative embodiment, movement of piston rod30in direction122will cause movement of slot68in direction122as well independent of pin110until it engages end124of slot68. When this occurs, piston rod30moves body50and consequently locating pin6upwardly in direction122. Conversely, as piston rod30is moved downwardly in direction120, piston rod30moves independently of body50until pin110engages end126of slot68. At that point body50is moved in direction120.

Dowel pin66is disposed within bore128of body50and is configured to retain twist pin54. Cam pin60is fixed in housing4and disposed through slot70of body50as well as cam slot58of twist pin54, where it exits to engage another opposed slot in body50and fixed at the opposite end in housing4. Also shown in this view is wiper seal62located within bore64between the inner wall of housing4and body50. Fingers8are shown partially disposed within cavity52of locating pin6as a result of engagement with pins56.

The attachment of unlocking mechanism20is also shown inFIG. 3a. In one illustrative embodiment lock release106is fastened to piston rod30, while spring holder88is fastened to body50. Plate84is fastened to the inside of cavity82via fasteners86. Pin108is located between a bearing surface132on plate84and a cam surface134formed on body50. A spring136is coupled to spring holder88and engages pin108to bias the same in direction120.

A detailed cross-sectional view of a portion of pin clamp assembly2is shown inFIG. 3b. This view specifically shows how cam pin60is disposed through housing4, as well as cam slot58. In this illustrative embodiment, cam pin60is disposed through bore61in one portion of housing4and is disposed through slot58of twist pin64. Exiting therefrom and re-entering bore61disposed through an opposite portion of housing4. The use of the single cam pin being disposed all the way through twist pin54as well as body50(through slot70), allows alignment of body50and twist pin54within housing4by virtue of the single simple pin60. In addition, this configuration does not require fasteners to secure pin60to housing4. In addition, cam pin60can rotate which will reduce the wear experienced by its surface to possibly add increased cycle life.

Several perspective views showing the progression of movement of locating pin6is shown inFIGS. 4athrough4d. As shown inFIG. 4a, locating pin6is extended upward in direction122to its upper most extent. In this position cam pin60, being secured in housing4as shown, is positioned at the lower most extent of slot70of body50and the lower most extent of cam slot58of twist pin54. Pin66secured to body50is shown retaining twist pin54in a vertical position with respect to locating pin6. In this upper most extended position, cam slot58is configured such that the orientation of pins56at the end of twist pin54locate fingers8in a retracted position. The perspective view of pin clamp assembly2shown inFIG. 4bdepicts movement of locating pin6downward in direction120. It is notable that in this view slot70, as well as cam slot58, appears to move in direction120relative to cam pin60. This causes cam pin60to be positioned farther up within slot70, as well as up the cam path of cam slot58. The result of this movement is that twist pin54twists or pivots within locating pin6along its longitudinal central axis pursuant to contour of the cam slot. This pivoting results in pins56pivoting as well. The movement of pin66causes fingers8to begin extending outwardly from locating pin6.

As shown in the locating clamp assembly2inFIG. 4c, locating pin6continues to move downwardly in direction120. This continued downward movement moves cam pin60farther along slot70of body50as well as farther along cam slot58. This movement continues to pivot twist pin54which causes continued rotation of pins56which essentially push fingers8farther outwardly from locating pin6. As locating pin6reaches the end of its stroke in direction120, as shown inFIG. 4d, cam pin60is shown reaching the upper most extent of both slot70and cam slot58. Reaching the end of the stroke also means that twist pin54has pivoted pins56which moves fingers8outward to their outer most extent. It is appreciated that in this position, a work piece can be held between fingers8and plate surface10.

Side and detail views of unlocking mechanism20of pin clamp2is shown inFIGS. 5aandb. As shown inFIG. 5a, cavity82is formed in the housing4of pin clamp2. This cavity82provides access to body50, as well as piston rod30. In one illustrative embodiment of unlocking mechanism20, it is configured to manually move locating pin6upward in direction122to retract the fingers and allow release of any held work piece. In this illustrative embodiment, as shown inFIG. 5b, a lever100(seeFIG. 2) or other structure or mechanism can push pin108upward unwedging pin108from between surfaces134and132. The force of the lever moving upward is greater than the downward bias of spring136to cause pin108to position itself in a nonwedging position between surfaces134and132. The illustrative shape of cam surface134is such that in the lower position, that surface serves as a wedging surface, whereas farther upward thereon, it no longer possesses such wedging properties. With pin108unwedged, the lever100will be free to push body50upward which causes cam pin60to move upward in direction122. This causes cam pin60to follow slot58which pivots pins56to retract fingers8inward with respect to locating pin6.

In another illustrative embodiment, mechanism20may also be a locking mechanism. This can be particularly useful during loss of fluid power to clamp2. Illustratively, when body50is moved in the downward direction120, the location of pin108with respect to the body50is caused to be wedged between surfaces132and134by the bias created from spring136. This wedging between the two surfaces prevents locating pin6from moving upwardly in direction122.

When power is restored to clamp2, however, the force of that power is sufficient to overcome the wedging force created by pin108and surfaces132,134. This is illustratively accomplished by the lock release106attached to piston rod30as shown inFIG. 6. In this illustrative embodiment, slot68and piston rod30(seeFIG. 3a) allow movement of piston rod30to some extent before it engages and moves body50. In this embodiment that extent of travel is enough to allow head138of lock release106to engage pin108. Using the force of the traveling piston rod30, pin108is pushed out of the way, thus, unwedging it from between surfaces132and134prior to piston rod30's engagement and movement of body50. Once pin108is unwedged, body50, and ultimately locating pin6, will be free to move upwardly in direction122.

Exploded, perspective, and cross-sectional detailed views of an illustrative shim and sleeve assembly140is shown inFIGS. 7athrough7c, respectively. As shown in the exploded view ofFIG. 7a, shim and sleeve assembly140comprises a sleeve78that is fastened to top76of housing4via fasteners80disposed through bores142and144disposed through sleeve78and top76, respectively. In one illustrative embodiment, shims74include bores146disposed therethrough that also receive fasteners80. Shims74can, thus, be sandwiched and secured between sleeve78and top76of housing4. It is appreciated, however, that the thickness of shims74can be any amount that is useful to provide a desirable amount of shrouding about locating pin6. The perspective view of shim and sleeve assembly140is shown inFIG. 7b. This view shows how locating pin6extends from bore79of sleeve78. The cross-sectional view ofFIG. 7cfurther illustrates the utility of shims74. As shown herein, shim74allows sleeve78to be adjusted upward or downward along locating pin6. The use of such shims74, means that the top surface of sleeve78may not require machining to obtain a desired amount of coverage about locating pin6.

Several cross-sectional views of a portion of the pin clamp assembly2showing an alternative embodiment of shim and sleeve assembly148is shown inFIGS. 8athroughc. A detail view of a portion of assembly2with wiper seal62is shown inFIG. 8d. With regard to shim and sleeve assembly148,FIG. 8a, shows an illustrative embodiment of sleeve152having a stepped portion which forms plate surface10that engages a portion of a work piece when fingers8become engaged. In this illustrative embodiment, fasteners80are configured to be disposed through sleeve152and attach the same to housing4. In this first view, no shim is used between housing4and sleeve152. In contrast, as shown inFIG. 8b, the same view of pin clamp2with sleeve assembly148attached thereto includes a shim154that effectively raises sleeve152upward relative to locating pin6to provide additional protection thereto. In this illustrative embodiment the amount of additional protection can be illustratively quantified by measuring an increase or decrease in gap156located between the underside of sleeve152and body50. Shim and sleeve assembly148, as shown inFIG. 8c, includes an illustrative thicker shim158that extends sleeve152further upward along locating pin6then shims154. It is evident by comparingFIGS. 8athroughcthat the thicker the shim158attached to housing4and sleeve152, the more of locating pin6is shrouded by sleeve152.

As shown inFIG. 8d, wiper seal62is configured to engage the outer periphery of body50. Wiper62is illustratively made from a flexible polymer material that essentially rubs against the outer periphery of body50to prevent any dirt or other contaminants thereon from penetrating to the structures located within housing4.

An exploded view of another illustrative embodiment of a pin clamp assembly170is shown inFIG. 9. In this illustrative embodiment the clamp assembly portion, i.e. the housing for locating pin6, cover plate12and many of the internal structures that move locating pin6, is also used herein with respect to assembly170. The primary distinction between the two embodiments is that pin clamp assembly170is electrically driven, as opposed to pin clamp assembly2which is pneumatically driven. As shown herein, controller172is illustratively mounted to cover174. The controller172can illustratively be configured to receive signals from an amplifier box and/or a customer control unit (not shown) to control motor176located within cover174. Motor adapter plate178illustratively mounts motor176to block180which is attached to housing4. In this illustrative embodiment, motor176positively drives sun gear182via cam coupling184. Sun gear182in turn drives planet gears186which revolve about shafts188while turning inside ring gear190. In this illustrative embodiment, shafts188are pressed into, or otherwise affixed, to output hub192. This causes hub192to revolve by the rotation of planet gears186. Output hub192is illustratively supported by bearing194which is also secured to block180. Output hub192is also coupled to drive screw196via clamp coupling198. Split nut halves200,202engage drive screw196and are held in place via carriers204,206, respectively. This arrangement allows the ability to manually release and cycle the electrical mechanism without power while still maintaining synchronization between controller172, and drive screw196. It is contemplated that an illustrative alternate embodiment would comprise split nuts200,202being formed integral with carriers204,206. In the present embodiment, carriers204,206engage drive rod208via slots210illustratively located opposite slot68which is formed similar to that of slot68of rod30from the prior illustrative embodiment. (SeeFIG. 2.) It is contemplated that slots210assist in preventing rotation of carriers204,206. It is further contemplated that drive rod208is movable in a linearly reciprocal fashion such as that described with respect to assembly2. The distinction here being that the electric motor176, along with the gear assemblies previously discussed, move rod208in such a fashion as opposed to the pneumatic power applied to piston28. The rotational movement from motor176is translated into linear movement via drive screw196on rod210.

A top view of an illustrative embodiment of a portion of the gear assemblies for pin clamp assembly170is shown inFIG. 10. This view shows motor adapter plate178retaining ring gear190having teeth illustrative disposed along its inner periphery that engages corresponding teeth on planet gears186that rotate about shafts188. The teeth of gears186also correspond and engage teeth on sun gear182.

A side cross-sectional view of pin clamp assembly170is shown inFIG. 11. This view shows the attachment of the electrical drive mechanism to the pin clamp. For example, motor176is shown located within cover174with an end cap212located at the end thereof. Shaft214is shown extending up through motor adapter plate178and attaching to sun gear182. The planet gears186are shown engaged with sun gear182, as well as ring gear190. The output hub192is shown located in block180and coupled to drive screw196and movable about bearing194. Block180is itself attached to the housing4of the pin clamp assembly. As shown, drive screw196is disposed in drive rod208moving it in directions122and120as screw196rotates. This movement in directions120and122of drive rod208are analogous to the movements of rod30in the previous embodiment. Accordingly, the remaining structures within housing4operate the same as described with respect to assembly2to move and operate locating pin6as previously discussed. (See, e.g.,FIG. 4.)

Although the present disclosure has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present disclosure and various changes and modifications may be made to adapt the various uses and characteristics without departing from the spirit and scope of the present invention as set forth in the following claims.