US2741829A - Snap ring tool - Google Patents

Description

April 17, 1956 J, KRQDEL 2,741,829

SNAP RING TOOL Filed May 2o, 1952 4 [Wil/11111111111111111111 IN VEN TOR.

United States Patent O SNAP RING TOOL Leander J'. Krodel, Westmont, lll., assigner to General Motors Corporation, Detroit, Mich., a corporation oi Delaware Application May 20, 1952, Serial No. 288,872.

4 ClBimS. (Cl. 29229) This invention relates generally to assembly and disassembly tools and more particularly to sliding pincer tools used to apply and remove open ended snap retaining rings.

In the various assemblies of manufacture the use of snap rings has become very extensive and today one may find snap rings in a variety of sizes and shapes. In fact, the only apparent limiting factor on even further increases in the use of such rings appears to be in the problem of applying these rings to their assemblies. Naturally, as larger size snap rings having stronger retaining characteristics are used, greater forces are needed to contract them. These greater forces usually mean increasing the size of the tool which applies and removes the snap rings. It readily can be seen that the maximum size snap ring that may be used will depend almost wholly on the size tool necessary to apply that ring. In other words, if the tool is so large that its operator finds it awkward and unwieldly to handle, it becomes impractical to use that tool and the size of snap ring it was made to handle.

Related to the above problem, a further ditliculty experienced by operators of snap ring tools has been maintaining the snap ring compressed for the period between compression and application. ln other words while the operator may have sulicient strength to compress the ring a correct amount, he does not possess enough strength to maintain the ring in its compressed condition until it can be applied. In an attempt to circumvent this diliculty, certain tools have been provided with locking devices which must be set manually by the operator after the ring has been compressed. However, if the operator is applying maximum force to the snap ring through the use of both hands on the tool, obviously any attempt on his part to set manually a locking device will result ultimately in no application of the ring.

It, therefore, becomes an object of this invention to provide a snap ring tool which due to its unique construction will compress snap rings of much greater size and strength than other tools of comparable weight and s1ze.

It is another object of this invention to provide a snap ring tool having a unique lock which is automatically applied when the snap ring is compressed a correct amount and which maintains the ring compressed during the period between the culmination of the act of compression and application.

It is a further object of this invention to provide a tool having a minimum of parts which is simple to operate and inexpensive to manufacture.

In the drawings:

Figure l is a front view of the new improved tool with one side removed showing ring engaging fingers in both an extended and retracted position.

Figure 2 is a section taken along the line 2 2 of Figure 1.

Figure 3 is a partial section taken along the line 3 3 rice showing the details of the thumb knob used to extend and retract the engaging lingers.

Figure 4 is a section taken along the line 4 4 and shows the locking means for holding the snap ring in its compressed condition.

Referring to Figure 1, the snap ring tool is shown generally by 2. The snap ring tool comprises a housing 4 which includes two sides 6 separated at one end by spacers 8 and at the other end by the spacing portion 10 of a handle 12. The two sides 6, the spacers 8 and the handle 12 with the spacing portion 10, are all fastened together by peened rivets 14. A spreader pin 16 is located at one end of the housing 4 and extends between the sides 6.

Located within the housing 4 are a pair of pivotally connected lingers 18 and 19. These fingers 18 and 19 extend outside the housing at one end thereof on opposite sides of the spreader pin 16. On the end of each finger, extending outside of the housing 4, are located work engaging pins 20. These work engaging pins 20 are adapted to lit in apertures provided in the snap ling itself.

Referring now to Figures l, 2 and 3, the sliding and pivoting assembly for operating the tool is shown. This assembly includes a bushing 22 adapted to slide in longitudinal slots 24 located in each side plate 6 and a fastening pin 26 contained within the bushing 22, which maintains serrated thumb knobs 28 on opposite sides of the housing 4. The bushing 22 also serves as the pivotal connection for the ngers 1S and 19.

The locking mechanism of the tool is more clearly illustrated in Figures l and 4. Figure l shows the slide bars 3 having inner surfaces 30 extending longitudinally along the tool. Adapted to mate with the surfaces on the slide bar 8 are surfaces 32 also extending longitudinally of the tool when the fingers 1S and 19 are in the retracted position. The forces created by the compressed retaining ring and obtained between these two sets of surfaces serve to hold the tool in its retracted position and the retaining ring in its compressed condition.

The operation of the tool is as follows: The thumb knobs 28 are pushed along the slots 24 to the bottom position therein. This will position the work engaging pins 29 as shown by the dotted lines in Figure l. These work engaging pins are placed in the retaining ring apertures with the retaining ring in its uncompressed condition. The thumb knobs 28 are then drawn upwardly along the slots 24 or else the handle i2 is pushed downwardly toward the retaining ring so that the thumb knobs 28 move upward along the slots 24 to the topmost position. At this point the surfaces 3d and 32 engage with each other to lock the tool with the retaining ring in its compressed condition. The ring then may be inserted in an internal groove at which time the thumb knobs are pushed downwardly again, releasing the retaining ring into its retaining groove.

l claim:

l. A tool for expanding and contracting retaining rings comprising an elongated housing having oppositely disposed slots running longitudinally therealong, a pair of parallel pins extending laterally through said housing and spaced longitudinally along said housing from each other, one of said pins riding in said slots and pivotally connecting a pair of rigid fingers located within said housing, said ngers having work engaging ends extending without said housing on opposite sides of the other of said pins, and means provided outside of said housing and on the one of said pins for moving the one of said pins and said connected fingers longitudinally with respect to said housing to retracted and extended positions, and means for retaining said fingers in said retracted position when compressing a retaining ring between said work engaging ends, said means including a pair of oppositely dissurfaces normal to the direction of forces exerted onV said ends by said retaining ring compressed therebetween, and surfaces on said lingers parallel rto the surfaces on said spacers and engageable therewith when said ngers are in said retracted position. Y

2. A tool for contracting and expanding Vretaining rings comprising a housing having oppositely disposed slots, a pair of parallel pins extending laterally through said housing and spaced from each other, Vone of said pins riding in saidV slots and pivotally connecting a pair of rigid fingers located within said housing, said lingers having work engaging ends extending Without said housing on opposite sides of the other of said pins, means for moving said fingers with respect to said housing to extended and retracted positions, Vand means for restraining movement of said fingers with respect to said housing when in said retracted position, said last means'including a surface in said housing normal to the direction of the Y forces exerted between said ends by retaining rings engageable therebetween, and an adjacent surface on one of said ngers parallel to the surface on said housing and engageable therewith when said fingers are in said retracted position.

3. A tool for expanding and contracting retaining rings and the like comprising a member, a pair of intersecting rigid fingers, said fingers being supported by said member and connected together where they intersect bymeans movable relative to said member, a finger spreading element on said member spaced from said means, said iingers extending past and engageable with said element on opposite sides thereof, linger camming means on said member spaced from said means and engageable with said ngers to reduce the amount of spread betweensaid lingers, said fingers having work Vengaging portions operable to expand and contract retaining rings and the like in response to movement of said means in dierent directions thereby causing said y iingers to move past said element and said linger camming means, and parallel engageable surfaces on said finger cammingmeans and said member for restraining movement of said ngers relative to said member otherwise caused by forces exerted between said lingers and said iinger camming means by retaining rings and the like compressed between said work engaging portions, said surfaces being normal to the forces exerted therebetween by retaining ringsV andV the like compressed between 'said work engaging portions.

4. A tool for expanding and contracting retaining rings and the like comprising an elongated housing having oppositely disposed slots running longitudinally therealong, a handle on one end of said housing, a pin extending laterally through said housing and guidable in said slots, a pair of intersecting fingers located within said housing and pivotally connected together at their intersection by said pin, a linger spreading element on said member ex tending laterally through said housing and spacedlongitudinally along said housing from said slots, said fingers defining a variable angle therebetween intermediate said pin and said element, said fingers extending past and engageable with said element on opposite sides thereof, said fingers having retaining ring engaging portions extending out yof said housing on opposite sides of said finger spreading element, a pair of spacers on either Vside of said element deiining guide openings therewith through which said fingers extend, said spacers having surfaces normal to the direction of forces exerted on said por-` tions by a retaining ring compressed therebetween, manually actuable thumb knobs provided outside of said housing and on said pin for moving said pin back and forth in said slots and said connected fingers through said guide openings toV alternately'spread said iingers and reduce the amount of spread between said ingers, said iingers being movable into said housing into a'predetermined retracted position, and surfaces on said fingers parallel to the Vs'urfaces on said spacers and engageable therewith whentsaid ngers are in said predetermined retracted position, Vsaid surfaces co-acting to restrain movement of said lingers relative to said housing which might otherwise be caused by forces exerted between said ngers and said spacers by retaining rings and the. like compressed between said work engaging portions. t t t References Cited in the fue of this patent UNITED STATES PATENTS Y 714,989 Worthington Dec. `2, 1902 1,851,126 Mikkelsen Mar. 29, 1932 2,441,756 De Swart May 18, 1948 2,574,195 Sherrick NOV. 6, 1951

Images