WO2000037843A1

WO2000037843A1 - Locking cam arm

Info

Publication number: WO2000037843A1
Application number: PCT/US1999/030603
Authority: WO
Inventors: Erik T. Quandt
Original assignee: Banjo Corporation
Priority date: 1998-12-22
Filing date: 1999-12-21
Publication date: 2000-06-29
Also published as: AU2713200A

Abstract

A cam arm (10, 12) for securing together interconnected coupling elements (14, 16) which includes a locking mechanism to prevent inadvertent cam arm shifting. The locking cam arm includes a body (48) that is assembled from multiple body parts (58, 60), such as two mirror-image body halves. A locking member (110), such as a one-piece pin, fits within an internal hollow (62, 75) of the body and includes a first portion (112) that projects beyond the body periphery through an opening in the cam profile, and a second portion (120) that protrudes beyond the body periphery through an opening provided in the handle of the body. A spring (130) housed within the internal hollow (62) of the body (60) biases the locking pin from a retracted position to a locking position. When the locking pin is disposed in the locking position, the pin portion protruding from the cam profile prevents cam arm rotation due to its engagement with a part of one of the coupling elements with which the locking arm is utilized. The second pin portion may be acted upon to move the locking pin from the locking position to the retracted position such that the locking cam arm may be pivoted. A method of forming a locking cam arm is also disclosed.

Description

LOCKING CAM ARM BACKGROUND OF THE INVENTION The present invention pertains to cam arms used to interconnect coupling elements, and, in particular, to a cam arm that may be locked in its engaged position to prevent inadvertent disconnection of interconnected coupling elements. Cam arms or levers are one well-known device utilized to releasably secure together interconnected coupling elements or assemblies. Such coupling elements are typically utilized to fiuidly connect hoses or other conduits used to convey fluids. Coupling assemblies also often include valves that may be manipulated to control the flow of fluid through the coupling assemblies and thereby the hoses to which the assemblies are connected.

To avoid a scenario in which the cam arm is inadvertently pivoted or shifted from an engaged position at which interconnected coupling elements are secured together to a release position at which interconnected coupling elements may be disconnected, a variety of locking mechanisms have been developed. One known locking mechanism including a pin that inserts into a dedicated aperture in the handle of the cam arm during opening of the valve of the coupling assembly is disclosed in U.S. Patent No. 5,595,217, which is incorporated in its entirety herein by reference. While particularly useful for coupling assemblies having valves, this design has less applicability with respect to some more simple coupling elements. Another known cam arm locking mechanism is disclosed in International

Publication Number WO 97/29313, which is incorporated in its entirety herein by reference. This mechanism provides certain advantages over other locking mechanisms of the prior art, and therefore has many beneficial applications. However, existing methods known to be currently used to manufacture the cam arm disclosed therein render that cam arm uneconomical for use in many applications. In particular, the complex shape of the cam arm body has heretofore been furnished by an investment casting process in which the body is formed in one piece. Subsequent to the cam arm body casting, the remainder of the locking mechanism's components are assembled and inserted into the cam arm body. As the investment casting process is fairly expensive to implement, and because the number and interrelationship of the component parts requires a relatively large amount of potentially costly assembly time, this prior art design may be prohibitively expensive for some applications.

Thus, it would be desirable to provide a device which overcomes these and other shortcomings of the prior art.

SUMMARY OF THE INVENTION The present invention provides a locking cam arm that includes a body assembled from multiple pieces and with an internal hollow in which a shiftable locking member and a biasing element are captured. The multiple part construction of the body allows it to be manufactured in a more cost-effective process, and further the cam arm is designed to be readily assembled so as to reduce required assembly time to aid in keeping the costs of production low.

In one form thereof, the present invention provides a locking cam arm of a first coupling element to be interconnected with a second coupling element, including a body and a locking member. The body is movably mountable to a portion of the first coupling element and includes a cam profile and a handle extending from that cam profile. The body is assembled from a plurality of body parts complementarily shaped to define an internal hollow within the body and at least two openings in a periphery of the body which open into the internal hollow. The locking member is shiftable relative to the body between a locking position and a release position. A first portion of the locking member, when the locking member is disposed in the locking position, protrudes beyond the body periphery through a first opening for limiting cam arm body movement relative to the first and second coupling elements when interconnected. A second portion of the locking member is disposed within the internal hollow. A third portion of the locking member protrudes beyond the body periphery through a second opening to be accessible to allow control of locking member movement.

In another form thereof, the present invention provides a connection system for first and second fluid conduits, including a first coupling element in flow communication with the first fluid conduit, wherein a portion of the first coupling element includes a radially outwardly facing recess, and a second coupling element in flow communication with the second fluid conduit. The second coupling element includes a locking cam arm having a body connected to a base portion of the second coupling element to be pivotable between a first position and a second position. The body includes a cam profile and a handle extending from the cam profile. The body is cooperatively structured and arranged with the recess including portion of the first coupling element such that the first and second coupling elements may be moved between a connected arrangement and a disconnected arrangement when the body is oriented in the first position and such that movement of the first and second coupling elements from the connected arrangement to the disconnected arrangement is prevented when the body is oriented in the second position. The body is assembled from a plurality of body parts complementarily shaped to define an internal hollow within the body and at least two openings in a periphery of the body which open into the internal hollow. The locking cam arm also includes a locking pin shiftable relative to the body between a locking position and a release position. The locking member has a first segment, a second segment and a third segment, wherein the first segment, when the locking pin is disposed in the locking position, protrudes beyond the body periphery through a first opening in the body periphery to prevent pivoting of the body from the second position to the first position when the first and second coupling elements are in the connected arrangement via abutting contact with the first coupling element. The first segment, when the locking member is shifted from the locking position toward the release position, at least partially retracts into the internal hollow of the body to permit pivoting of the body from the second position to the first position. The second segment is disposed within the internal hollow, and the third segment protrudes beyond the body periphery through a second opening in the body periphery to be accessible to allow control of locking pin movement.

In still another form thereof, the present invention provides a method of producing a locking cam arm comprising the steps of using powder metallurgy to form a first body section, using powder metallurgy to form a second body section, assembling the first and second body sections to form a body including a cam profile and a handle extending from the cam profile, wherein the assembled body sections include an internal hollow and first and second openings in a body periphery which open into the internal hollow, and installing a one-piece locking pin into the internal hollow, wherein the locking pin includes a first segment that protrudes beyond the body periphery through the first opening for limiting cam arm movement and a second segment protruding beyond the body periphery through the second opening to be accessible to allow shifting of the locking pin between a release position and a locked position.

One advantage of the present invention is that a cam arm is provided with a locking mechanism that prevents inadvertent pivoting of the cam arm from an engaged position to a release position at which coupling elements otherwise secured together by the cam arm may be disconnected.

Another advantage of the present invention is that a locking cam arm is provided with a body comprised of multiple parts that allows for a more low-cost manufacture.

Another advantage of the present invention is that a locking cam arm is provided which may be easily assembled, thereby maintaining relatively low the costs associated with assembly of the device.

Still another advantage of the present invention is that a cam arm locking pin is provided as a single piece not requiring post-manufacture assembly.

BRIEF DESCRIPTION OF THE DRAWINGS The above mentioned and other advantages and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a diagrammatic top view, in partial cross-section, of male and female coupling elements being secured together by a pair of locking cam arms of the present invention shown in their engaged positions; Fig. 2 is a diagrammatic top view of an alternate type of mating coupling elements being secured together by a pair of locking cam arms of the present invention shown in their engaged positions;

Fig. 3 is a top view of a locking cam arm of the present invention shown separately from the coupling elements of Fig. 1 ;

Fig. 4 is an exploded perspective view of the locking cam arm of Fig. 3;

Fig. 5 is a side view of the locking cam arm of Fig. 3, wherein the locking pin is not shown for purposes of illustration;

Fig. 6 is an opposite side view of the locking cam arm of Fig. 5. wherein the locking pin is still not shown for purposes of illustration;

Fig. 7 is a top view of the locking cam arm of Fig. 3, wherein the top section of the cam arm body has been removed; and

Fig. 8 is a diagrammatic top view of the coupling elements of Fig. 2 after the locking pins have been manually retracted and the cam arms have each been pivoted to a release position.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent an embodiment of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated or omitted in order to better illustrate and explain the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to Fig. 1 , there is shown a diagrammatic top view of a pair of locking cam arms, generally designated 10 and 12, configured according to a preferred embodiment of the present invention. Locking cam arms 10 and 12 are being employed to releasably secure together interconnected female and male coupling elements, generally designated 14 and 16. Coupling elements 14 and 16 may be provided on not shown hoses or other types of fluid conduits in a conventional fashion.

Locking cam arm 10 is pivotally connected by pin 18 to a pair of lobes or ears indicated at 19 that radially project from the female coupling element base 20 and which flank cam arm 10. Cam arm 12 similarly is pivotally connected at 21 to a pair of cam arm flanking ears indicated at 22. When in the engaged position shown in Fig. 1 , the cam profiles of cam arms 10 and 12 extend through openings in base 20 into the interior volume 24 of female coupling element 14. Male coupling element 16 includes a projecting male portion 26 that is insertably received within interior volume 24 of female coupling element 14 during interconnection. A circumferential groove or recess portion 27 in male portion 26 cooperates with the cam profiles of cam arms 10 and 12 described below in locking together coupling elements 14 and 16. The shown configuration of coupling elements 14 and 16 is merely illustrative and not intended to be limiting, as the inventive cam arms may be employed with other coupling elements within the scope of the invention. For example, one or more cam arms 10 may be used with coupling assemblies having rotatable valves. Furthermore, the cam arms may be employed with coupling elements of the type shown in Fig. 2, in which interconnected coupling elements 14' and 16' mate in an abutting relationship. Locking cam arm 10 is pivotally connected by pin 29 to a pair of lobes or ears indicated at 30 that radially project from the coupling element base and which flank cam arm 10. Cam arm 12 similarly is pivotally connected at 31 to a pair of cam arm flanking ears indicated at 32. Coupling element 16' includes two pairs of radially projecting ears 33 and 34 that are spaced approximately 180° apart around the body circumference of coupling element 16'. Separate profile inserts or cam fingers 35 and 36 include radially outwardly facing, radiused recesses 38 and 40, respectively, which serve the purpose of circumferential groove 27 in male portion 26 in the embodiment of Fig. 1. Profile inserts 35 and 36 are fixedly held within ears 33 and 34, respectively, via retaining pins 42 and 44. Profile inserts 35 and 36 forwardly project beyond the end of coupling element 16' which abuts coupling element 14'. With additional reference now to Figs. 3-7, the construction of locking cam arm 10 will be further described. Locking cam arm 12 is identically constructed to locking cam arm 10 in this embodiment, and therefore the following description of cam arm 10 has equal application to cam arm 12.

The body 48 of cam arm 10 includes a cam profile or camming lobe 50 from which rearwardly extends a handle portion 52. Body 48 is formed of a rigid and durable material, such as stainless steel. A pivot pin accommodating opening 54 with a chamfered mouth 56 is offset within cam profile 50 such that cam profile 50 projects into and engages the surface that defines circumferential groove 27 of male coupling element 16 during operation. The overall size and shape of cam profile 50 is cooperatively designed with groove 27 to achieve a locking engagement when coupling elements 14 and 16 are arranged in a connected relationship and cam arm 10 has been pivoted about pin 18 to the engaged position shown in Fig. 1. Complementary shapes of the cam profile 50 and groove 27 other than that shown in Fig. 1 may naturally be substituted if desired. As further shown in Fig. 4, cam arm body 48 is formed from a pair of body sections generally indicated at 58 and 60. While body 48 may be formed from a greater number of sections, the use of two body sections achieves the locking member capture desired without unduly complicating cam arm assembly. In the shown embodiment, top body section 58 and bottom body section 60 are mirror images of each other and thus constitute body halves. It will be appreciated that such a mirror image configuration is not required to practice the present invention. In particular, the full volume of the locking member accommodating internal hollow of body 48 described below may be furnished within a first body section, with the second body section merely being a flat element that is assembled to the first body section to close off the internal hollow as appropriate.

Regions of the top or inner face 61 of body section 60 are recessed so as to form an internal hollow, generally designated 62. Internal hollow 62 is multi-tiered, and includes first and second recessed regions 70, 72 that are of a first depth, and a third recessed region 74 that is deeper and rectangular in shape. Recessed regions 70 and 72 extend at multiple locations to the otherwise continuous periphery of body half 60 so as to form notched periphery portions 64, 66 and 68. A second internal hollow 75, which is distinct from internal hollow 62 and serves to retain the locking pin distal tip, is formed by a recessed body region 78 that extends to the periphery of body half 60 to form notched periphery' portion 80. As best shown in Figs. 5 and 6, the notched periphery portions 64, 66, 68 and 80 of body half 60, together with the mirror-image, corresponding notched periphery portions of body half 58 which are referenced at 64', 66', 68' and 80', define four rectangular openings 84, 86, 88 and 90 through which the locking member (not shown in Figs. 5 and 6) passes through the periphery of body 48. Openings 84 and 86 are directly adjacent and separated only by the forward edges 92, 92' of portions of body sections 60 and 58.

With primary reference again to Fig. 4, body halves 58 and 60 are maintained in an assembled arrangement when mounted to the remainder of coupling element 14 by the insertion of pivot pin 18 through body bore 54, which is comprised of smooth bores 96 and 98 through body sections 58 and 60, respectively. A roll pin 100 frictionally fits within throughbores 102 and 104 of body sections 58 and 60, respectively, to further maintain the relative alignment of body sections 58 and 60 and to further retain cam arm 10 in an assembled condition. Fasteners other than the shown roll pin, including groove pins, screws and clips, may be utilized within the scope of the invention to secure together the body sections that form body 48. Furthermore, such fasteners can be dispensed with altogether in situations where the camming arm body sections are complementarily designed such that relative movement therebetween after assembly is prevented and the presence of pivot pin 18 within cam profile 50 is sufficient to maintain the body sections in an assembled arrangement.

A preferred manner of manufacturing cam arm 10 involves forming body 48 with powdered metallurgy. In this technology, a die is provided with an opening in the form of the outline of the cam arm body 48 shown in Fig. 3. One ram or punch, which is positioned below the die so as to define a cavity with the die opening, works with a second ram that moves down from above the die to compress powdered metal distributed into the die opening and onto the bottom ram. Typically, one of the rams has a generally flat surface, while the other ram includes projections used to form the inner face recessed portions and throughbores within the body section. After the rams compress the powdered metal within the die, the now formed part is ejected from the ΛVO Ob/37843 PCT/US99/30603

die and delivered to a furnace for sintering, after which the part is cooled and readied for use. Additional specifics of the powdered metallurgy process are not further described herein as such are well known by those skilled in the art, such as illustrated by the publication, "Powder Metallurgy-Design Solutions ' published in 1993 by the Metal Powder Industries Federation, which is incorporated in its entirety herein by reference.

With primary reference to Fig. 7, a locking member captured yet shiftable within body 48 after assembly is generally designated 110. In the preferred embodiment, locking member 110 is a one-piece locking pin that is made of a stainless steel wire form bent at specific angles and locations along its length to conform to the internal hollows and periphery opening of body 48. Locking members with alternate shapes and constructions, including different materials, may be substituted by one of skill in the art.

Locking pin 110 includes a locking tip 112 that protrudes beyond the periphery of body 48 through body opening 90. The rearward region of locking tip 112 ends at a ninety-degree bend segment 114 that leads to a multi-angled segment 116 that includes two forty-five degree bends to conform to the forward surface of internal hollow 62. Multi-angled segment 116 terminates in a ninety-degree bend segment 118 that protrudes through opening 88 to a rearward and downward bent grip segment 120. Pin 110 continues with a rear tip segment 122 that inserts within body hollow

75. The insertion of rear tip segment 122 of pin 110 in hollow 75 aids in preventing the locking pin from being bent away or otherwise deformed through inadvertent contact by grip segment 120 with external objects in the environment in which the coupling element may be employed. Grip segment 120 of pin 1 10 serves as a handle area which allows the pin to be manually pushed back against the return force provided by a coiled metal spring 130 installed within the deeper recess region 74 of internal hollow 62. In an alternate embodiment, grip segment 120 may be provided in the form of a loop, and tip segment 122 and hollow 75 may be eliminated.

With continued reference to Fig. 7, the rearward area of recessed region 74 and surfaces 132, 134 and 136 of body half 60, in conjunction with their corresponding elements in body half 58, provide a blind cavity, opening only at its forward end, for retaining spring 130. The rearward end of spring 130 abuts body surface 134, and the forward end of spring 130 abuts the rearward face of pin segment 1 18. While a coiled spring is preferred as a pin biasing element due to its low cost and ease of assembly, other known biasing elements could be substituted within the scope of the present invention.

The structure of locking cam arm 10 will be further understood in view of the following description of its operation. While described with reference to the coupling elements of Fig. 2, the locking cam arms function identically with the coupling elements of Fig. 1. When coupling elements 14' and 16' are arranged in the connected relationship shown in Fig. 2, and after the locking cam arms 10 and 12 have been pivoted to the engaged position shown in Fig. 2, coupling elements 14' and 16' are secured together so as to preclude their inadvertent disconnection. In order to disconnect the coupling elements, it is necessary to pivot cam arms 10 and 12 from the engaged position shown in Fig. 2 to a release position at which profile inserts 35 and 36 are free to be withdrawn from the spaces between the cam profiles and the base of coupling element 14'. However, pivoting of cam arm 10, and naturally the pivoting of cam arm 12 which is not further described because its operation is identical to cam arm 10, is prevented due to the protruding of locking tip 112 from cam profile 50. In particular, efforts to pivot cam arm 10 in a clockwise direction from the perspective of a Fig. 2 viewer will result in the side of pin tip 112 abutting profile insert 35, which prevents further rotation. In order for cam arm 10 to be rotated to the release position, a user must retract pin tip 112 a sufficient distance so as to allow this cam arm rotation. Typically, this pin retraction is achieved by pushing grip section 120 rearwardly with one's finger. Enough force must be applied on grip section 120 to overcome the return force provided by spring 130. As locking pin 110 is shifted, pin segment 1 14 moves rearwardly through body opening 88 so as to be visible as shown in Fig. 8. After locking pin 1 10 has been sufficiently retracted, cam arm 10 may be rotated to its release position shown in Fig. 8. Provided both cam arms 10 and 12 have been pivoted to this release position, coupling element 16' may then be disconnected from coupling element 14'.

To reconnect and secure together the coupling elements, the above-described process is generally reversed, with a difference being that the locking pins 110 automatically retract to allow cam arm pivoting during this process. Specifically, after the coupling element profile inserts 35 and 36 have been inserted, pivoting of cam arms 10 and 12 from their release positions toward their engaged positions causes the forward faces of locking tips 112 to contact profile inserts 35 and 36. This contact forces locking pins 110 to move toward their retracted positions against the return force of the biasing springs. When the cam arms 10 and 12 reach their engaged positions, the biasing springs sufficiently extend the locking pins 110 to an arrangement where the pivoting of the cam arms 10 and 12 back toward their release positions is prevented by the lateral abutting of pin tips 112 against profile inserts 35 and 36. While this invention has been shown and described as having multiple designs, the present invention may be further modified within the spirit and scope of this disclosure. For example, the locking pin could project out of a different portion of the camming arm, as well as engage a different portion of either coupling element so as to prevent inadvertent coupling disconnection. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

Claims

WHAT IS CLAIMED IS:

1. A locking cam arm of a first coupling element to be interconnected with a second coupling element, comprising: a body movably mountable to a portion of the first coupling element and including a cam profile and a handle extending from said cam profile, said body being assembled from a plurality of body parts complementarily shaped to define an internal hollow within said body and at least two openings in a periphery of said body which open into said internal hollow, said at least two openings comprising a first opening and a second opening; and a locking member shiftable relative to said body between a locking position and a release position, said locking member comprising a first portion, a second portion and a third portion, wherein said first portion, when said locking member is disposed in said locking position, protrudes beyond said body periphery through said first opening for limiting cam arm body movement relative to the first and second coupling elements when interconnected, wherein said second portion is disposed within said internal hollow, and wherein said third portion protrudes beyond said body periphery through said second opening to be accessible to allow control of locking member movement.

2. The locking cam arm of claim 1 wherein said first opening is disposed in said cam profile of said body.

3. The locking cam arm of claim 1 wherein said plurality of body parts comprises a first body section and a second body section, and wherein said second opening is disposed in said handle of said body along an interface of said first and second body sections.

4. The locking cam arm of claim 1 wherein said locking member comprises a one-piece construction.

5. The locking cam arm of claim 4 wherein said locking member comprises a multi-angled wire form.

6. The locking cam arm of claim 1 wherein said at least two openings comprises a third opening, wherein said third opening is disposed in said cam profile, and wherein said second portion protrudes beyond said body periphery through said third opening when said locking member is arranged in said release position.

7. The locking cam arm of claim 1 further comprising a biasing element within said internal hollow to bias said locking member toward said locking position.

8. The locking cam arm of claim 7 wherein said internal hollow comprises a blind cavity, said biasing element comprising a coiled spring disposed within said blind cavity.

9. The locking cam arm of claim 8 wherein a first end of said coiled spring abuts an internal surface of said body defining a closed end of said blind cavity, and wherein a second end of said coiled spring opposite said first end directly abuts said second portion of said locking member.

10. The locking cam arm of claim 1 wherein said plurality of body parts consists of a first body section and a second body section, and further comprising a fastener for securing together said first and second body sections.

1 1. The locking cam arm of claim 10 wherein said first body section is a mirror-image of said second body section.

12. The locking cam arm of claim 10 wherein said fastener comprises a roll pin received within a bore provided in each of said first and second body sections.

13. The locking cam arm of claim 1 wherein said plurality of body parts define a second internal hollow within said body, wherein said locking member comprises a fourth portion extending from said third portion, and wherein said locking member fourth portion inserts within said second internal hollow.

14. The locking pin of claim 13 wherein said second internal hollow comprises a blind cavity.

15. A connection system for first and second fluid conduits, comprising: a first coupling element in flow communication with the first fluid conduit, wherein a portion of said first coupling element includes a radially outwardly facing recess; and a second coupling element in flow communication with the second fluid conduit, said second coupling element comprising a locking cam arm and a base portion, wherein said locking cam arm comprises: a body connected to said base portion to be pivotable between a first position and a second position, said body including a cam profile and a handle extending from said cam profile, said body being cooperatively structured and arranged with said recess including portion of said first coupling element such that said first and second coupling elements may be moved between a connected arrangement and a disconnected arrangement when said body is oriented in said first position and such that movement of said first and second coupling elements from the connected arrangement to the disconnected arrangement is prevented when said body is oriented in said second position, said body being assembled from a plurality of body parts complementarily shaped to define an internal hollow within said body and at least two openings in a periphery of said body which open into said internal hollow, said at least two openings comprising a first opening and a second opening; and a locking pin shiftable relative to said body between a locking position and a release position, said locking member comprising a first segment, a second segment and a third segment, wherein said first segment, when said locking pin is disposed in said locking position, protrudes beyond said body periphery through said first opening to prevent pivoting of said body from said second position to said first position when said first and second coupling elements are in the connected arrangement via abutting contact with said first coupling element, wherein said first segment, when said locking member is shifted from said locking position toward said release position, at least partially retracts into said internal hollow of said body to permit pivoting of said body from said second position to said first position, wherein said second segment is disposed within said internal hollow, and wherein said third segment protrudes beyond said body periphery through said second opening to be accessible to allow control of locking pin movement.

16. The connection system of claim 15 wherein said locking pin comprises a multi-angled wire form having a one-piece construction.

17. The connection system of claim 15 wherein said plurality of body parts consists of a first body section and a second body section, and wherein said first body section is a mirror-image of said second body section.

18. The connection system of claim 15 further comprising a coiled spring disposed within a blind cavity portion of said internal hollow, wherein a first end of said coiled spring abuts an internal surface of said body defining a closed end of said blind cavity, and wherein a second end of said coiled spring opposite said first end directly abuts said second segment of said locking pin.

19. A method of producing a locking cam arm comprising the steps of: using powder metallurgy to form a first body section; using powder metallurgy to form a second body section; assembling said first and second body sections to form a body including a cam profile and a handle extending from said cam profile, wherein said assembled body sections include an internal hollow and first and second openings in a body periphery which open into the internal hollow; and installing a one-piece locking pin into said internal hollow, said locking pin including a first segment that protrudes beyond the body periphery through the first opening for limiting cam arm movement and a second segment protruding beyond the body periphery through the second opening to be accessible to allow shifting of the locking pin between a release position and a locked position.

20. The method of claim 19 further comprising the step of installing a coiled spring within the internal hollow to bias the locking pin from the release position toward the locked position.