Abstract:
A convertible retaining ring pliers has a pivot, first and second jaws and first and second handles rotatably secured about the pivot. A pair of transfer pins is slidably disposed for selective movement in the first and second jaws and the first and second handles for establishing alternative operating positions enabling the jaws to move inwardly as the handles move inwardly and allowing the jaws to move outwardly as the handles inwardly. A switching mechanism is mounted to the handles and pivot for providing simultaneous shifting of the transfer pins in the jaws of the handles. The switching mechanism includes first and second flexing spring plates which are mounted on opposite ends of the pivot and disposed on opposite external surfaces of the handles. Each of the spring plates includes a pair of boss pins engageable with opposite ends of the transfer pins. In each operating position, one pair of corresponding boss pins on the first and second spring plates lie raised above the external surfaces of the handles, and another pair of corresponding boss pins lie recessed in the first and second handles.

Description:
FIELD OF THE INVENTION 
   The present invention relates broadly to retaining ring pliers used to remove and replace both internal and external retaining rings. Such pliers are convertible between a first position which allows the jaws to move inwardly as the handles are moved inwardly, and a second position which enables the jaws to move outwardly as the handles are moved inwardly. More particularly, the invention relates to a switching mechanism provided on the retaining ring pliers to more easily effect the transfer between the first and second positions. 
    BACKGROUND OF THE INVENTION 
   Retaining rings are utilized in annular grooves on shafts and ends of shafts to retain bearings, collars, and the like on the shaft. A retaining ring extends circumferentially between a pair of ends which have hubs. The hubs have apertures that receive tips of a plier tool. The force applied by the pliers either spreads the hubs to expand the ring or squeezes the hubs to contract the ring. The plier tool is necessary for installing the retaining ring in and removing the retaining ring from either external or internal grooves. 
   Accordingly, it is sometimes desirable to squeeze the handles to effect movement of the jaws outwardly to expand the ring. It is at other times desirable to squeeze the handles to effect movement of the jaws inwardly to contract the ring. Thus, it is desirable to provide a pliers that is convertible between an external and an internal tool. U.S. Pat. Nos. 4,280,265 and 4,476,750 disclose a pair of retaining ring pliers that utilize a pair of separate coplanar jaws and a pair of separate handles that range about a common fixed pivot point and that are adapted to be changed to alternately engage one handle to one jaw and the other handle to the other jaw and vice versa to permit the changing of the tool from external to internal. Two fulcrum or transfer pins of a latching arrangement are disposed in the jaws and are adapted to alternately engage each set of the handles to shift from a position adapted to move the jaws inwardly as the handles are moved inwardly, to a position where the jaws are moved outwardly as the handles are moved inwardly. 
   The prior art retaining ring pliers in the &#39;265 and &#39;750 patents require that a user have a dull pointed instrument, such as a pen, nail or screwdriver, handy to forcefully push the pins between their alternate positions. Specifically, the user would have to squeeze the handles of the pliers inwardly to align the transfer pins of the latching arrangement with holes formed in the handles, and then use the pointed instrument to push the pins from each respective side of the pliers. Thus, each of the transfer pins disclosed in the above-noted patents has to be independently placed in the correct position using an additional tool. 
   Accordingly, it is desirable to provide a convertible retaining ring pliers that does not require another instrument or tool to convert the pliers from internal to external mode and vice versa. It is further desirable to provide a relatively simple switching mechanism which will enable finger pressure to be simultaneously applied to the transfer pins from each side of the pliers, while the handles are moved inwardly to align the transfer pins with the proper holes in the jaws. It is intended that the simultaneous movement of the transfer pins will make the conversion faster than previous models with far less complexity required in the plier structure. 
   SUMMARY OF THE INVENTION 
   It is one object of the present invention to provide a switching mechanism in a convertible retaining ring pliers for selectively and alternatively joining relative moveable external members to a common internal member in a more efficient manner. 
   It is also an object of the present invention to provide a switching mechanism in a retaining ring pliers for enabling simultaneous shifting of the transfer pins. 
   It is a further object of the present invention to provide a switching mechanism in a retaining ring pliers which provides a user with an enhanced visual indication of the operating position of the pliers. 
   It is an additional object of the present invention to provide a switching mechanism in a retaining ring pliers wherein the mechanism includes a pair of switches which flex to allow the simultaneous shifting of the transfer pins and hold the transfer pins in their desired operating positions. 
   Another object of the present invention is to provide a retaining ring pliers switching mechanism which has a minimum of parts and is simple to assemble and operate. 
   In one aspect of the invention, a retaining ring pliers includes a pivot assembly and first and second jaws arranged for oscillation toward and away from each other about the pivot assembly. The handles have portions adjacent to the pivot assembly disposed on respective opposite sides of the jaws. A transfer pin is slidably disposed in each jaw for alternative engagement with one or the other of the handle portions. The transfer pins are disposed in transverse bores in the jaws having axes parallel to the axis of the pivot assembly. Each of the handle portions has a pair of spaced holes disposed to receive the transfer pins. The transfer pins in the first and second jaws are selectively slidably engaged in the holes of respective first and second handles to effect movement of the jaws towards each other when the handles are moved towards each other to define a first operating position. The transfer pins in the first and second jaws are selectively slidably engaged in the holes of respective second and first handles to effect movement of the jaws away from each other as the handles are moved toward each other to define a second operating position. The pliers is improved by means of a switching mechanism mounted to the pivot assembly and in contact with external surfaces of the handle portions and the transfer pins for enabling simultaneous shifting of the transfer pins in the first and second jaws and holes of the first and second handles. The switching mechanism includes a first flexing spring plate disposed on the external surface of one handle portion, and a second flexing spring plate disposed on the external surface of the other handle portion. Each of the spring plates has a pair of boss pins engageable with opposite ends of the transfer pins. 
   Each spring plate has an external arcuate-shaped portion integrally joined by a connecting segment to an internal, circular anchoring portion. The external portion, the connecting segment and the internal portion are all substantially coplanar. The external portion has a pair of curved arms held spaced apart from the internal portion. An outer end of each curved arm is provided with one of the boss pins. The internal portion of the first spring plate is anchored to one end of the pivot assembly, and the internal portion of the second spring plate is joined to an opposite end of the pivot assembly. In each spring plate, each curved arm is temporarily deformable about a fulcrum point defined by the connecting segment. For a given operating position, one pair of corresponding boss pins on the first and second spring plates lie raised above the external surfaces of the handle portions, and another pair of corresponding boss pins lie recessed in holes of the first and second handles. Each boss pin lies between an underside of one of the curved arms and an outermost end of the transfer pins. In each operating position, one of the curved arms of each spring plate lies flush against the external surface of one of the handles, and the other of the curved arms of the spring plate is temporarily bent upwardly relative to the external surface of the handle. 
   In another aspect of the invention, a convertible retaining ring pliers includes a pivot, and first and second jaws as well as first and second handles rotatably joined about the pivot. A pair of transfer pins is slidably disposed for selective movement in the first and second jaws and the first and second handles for establishing a first operating position enabling the jaws to move inwardly as the handles move inwardly, and a second operating position allowing the jaws to move outwardly as the handles move inwardly. A switching mechanism is mounted to the handles at the pivot for providing simultaneous shifting of the transfer pins in the jaws of the handles between the first and second operating positions. The switching mechanism includes a first flexing spring plate mounted to one end of the pivot and disposed on an external surface of the first handle, and a second flexing spring plate mounted to an opposite end of the pivot and disposed on an external surface of the second handle. Each of the spring plates has a pair of boss pins engageable with opposite ends of the transfer pins. In each operating position, one pair of corresponding boss pins on the first and second spring plates lie raised above the external surfaces of the handles, and another pair of corresponding boss pins lies recessed in the first and second handles. 
   The invention further contemplates a method of converting a retaining ring pliers having a pivot, first and second jaws rotatably secured to the pivot, first and second handles rotatably joined about the pivot, and a pair of transfer pins slidably disposed for selective movement in the first and second jaws and the first and second handles between one operating position enabling the jaws to move inwardly as the handles move inwardly, and a second operating position enabling the jaws to move outwardly as the handles move inwardly. The method includes the steps of mounting a first flexing spring plate having a first pair of boss pins at opposite ends thereof to one end of the pivot such that the first spring plate is disposed on an external surface and the first pair of boss pins are engageable with opposite ends of the transfer pin; mounting a second flexing spring plate having a second pair of boss pins at opposite ends thereof to an opposite end of the pivot such that the second spring plate is disposed on an external surface of the second handle and the second pair of boss pins are engageable with opposite ends of the transfer pins. In each operating position, one pair of corresponding boss pins on the first and second spring plates lie raised above the external surfaces of the handles, and another pair of corresponding boss pins lie recessed in the first and second handles. Finger pressure is applied to ends of the spring plates carrying the raised boss pins to simultaneously shift the transfer pins between the first and second operating positions. 
   Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
       FIG. 1  is a top plan view of a retaining ring pliers having a switching mechanism embodying the present invention; 
       FIG. 2  is a side elevational view thereof; 
       FIG. 3  is an exploded view of  FIG. 1 ; 
       FIG. 4  is a sectional view taken on line  4 — 4  of  FIG. 1 ; 
       FIG. 5  is a sectional view taken on line  5 — 5  of  FIG. 1  showing the transfer pins in one position; 
       FIG. 6  is a sectional view like  FIG. 5  showing the transfer pins in an alternate position; 
       FIG. 7  is a sectional view taken on line  7 — 7  of  FIG. 1 ; 
       FIG. 8  is a top plan view of a spring used in the switching mechanism; 
       FIG. 9  is a side view of the spring of  FIG. 8 ; 
       FIG. 10  is a top plan view of a switch boss pin of the switching mechanism; 
       FIG. 11  is a front view of the switch boss pin of  FIG. 10 ; 
       FIG. 12  is a sectional view taken on line  12 — 12  of  FIG. 1  showing an external ring mode; and 
       FIG. 13  is a sectional view like  FIG. 12  showing an internal ring mode. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to  FIGS. 1–3  of the drawings, thereshown is a convertible retaining ring pliers  10  provided with a switching mechanism  12  employing the present invention. The pliers  10  is generally comprised of a pair of handles  14 ,  16 , a pair of elongated jaws  18 ,  20 , and a pivot pin  22 . The pivot pin  22  is preferably formed by a screw  24  having a head  25  and a threaded shaft  26  which is threadably received in a barrel  28  of a nut  30  with a head  31 . The handles  14 ,  16  include grips  32  that provide covering to the handles which are generally manufactured of a hard metal. The handles  14 ,  16  are urged apart by a spring  34  disposed between two opposed lugs  36 ,  38  on the interior sides of both handles  14 ,  16 . In the retaining ring pliers  10  described, the jaws  18 ,  20  are designed for mounting of work implements in the form of elongated retaining ring tips  40  having operator posts at the distal ends to be received in the lug holes of standard retaining rings. 
   As best seen in  FIGS. 1 ,  3  and  4 , the jaws  18 ,  20  are disposed in side by side relation and have transverse, cylindrically concave bearing recesses  42  for bearing engagement with a cylindrical portion of pivot pin  22 . At its opposite faces, each jaw  18 ,  20  is provided with a projecting semicircular flange  44  which provides an external bearing shoulder  46  concentric with its bearing recess  42 . 
   The handles  14  and  16  may be fabricated from suitable plate material, such as steel and are enlarged at the opposite ends thereof to define end plates  48 ,  49  which are disposed parallel to each other to partially confine the jaws  18  and  20  and to enclose other components of the pliers  10  to be described. 
   The handle end plates  48 ,  49  are provided with transverse bores  50  to pass the pivot pin  22 , and are also provided with recesses concentric with the bores  50  and providing internal cylindrical bearing shoulders  52  for coaction with the bearing shoulders  46  of the jaws  18 ,  20 . Through coaction then of the pivot pin  22  and the bearing shoulders  46  and  52 , both jaws  18 ,  20  and both handles  14 ,  16  are mounted for rotation about a common defined axis. These principal components are maintained in the operative relation by the pivot pin  22 . 
   To effect the convertability of the pliers  10 , means are provided for coupling each of the jaws  18 ,  20  alternatively to one or the other of the two handles  14 ,  16 . In this manner, the jaw  18 ,  20  is operatively linked to one or the other of the handles  14 ,  16  for oscillation therewith about the pivot  22 . To accomplish this, each jaw  18 ,  20  is provided at its inner end with a transverse bore  54  ( FIG. 5 ) spaced from and parallel to its respective bearing recess  42 . This bore  54  is cylindrical except that it is provided, at one side, with an elongated recess or groove  55 , best seen in  FIG. 7 , which is coextensive with the bore  54 . Elongated cylindrical transfer pins  56  and  58  are disposed in these bores  54  and are dimensioned for a close sliding fit within the bores, as best seen in  FIGS. 5 and 6 . Each transfer pin  56 ,  58  is provided with an external annular groove  60  equidistant between its ends, dimensioned to receive a retaining device such as a control spring  62 . The control spring  62  is a generally C-shaped wire spring having a tangential tab  64  ( FIG. 7 ), and is formed with a free diameter larger than that of a bore  54  so that the spring  62  when confined in transfer pin annular groove  60  will expand into frictional engagement with the bore walls  54 . The control spring tab  64  is configured to extend into the longitudinal recess  55  providing a control function to be described. 
   The handle end plates  48 ,  49  are each provided with a pair of transverse bores  66  and  68  spaced from each other and from the pivot pin bore  50  and disposed to be axially aligned with respective bores  54  of the jaws  18 ,  20  in selected relative position. These handle bores  66 ,  68  have the same diameter as the bores  54  of the jaws  18 ,  20  so that when a transfer pin  56 ,  58  is received within a handle bore  66 ,  68 , that handle  14 ,  16  is securely coupled to the respective jaw  18 ,  20 . As best seen in  FIGS. 5 and 6 , the transfer pins have a length such that when a pin is fully confined within a jaw bore  54  it has an outermost end  70  which is flush with the external face of the handle end plate  48  or  49 . In assembled relation of the pliers  10 , it will be seen that the handle end plates  48 ,  49  are continguous to the opposite faces of the jaws  18 ,  20  and maintained in that relation by the pivot pin assembly  22 , and it will be seen that the transfer pins  56 ,  58  are confined within the assembly by the coaction of the control spring tabs  64  within the recesses  55  of the jaw bores  54 . 
   Referring now to  FIGS. 3 , and  8 – 13 , the switching mechanism  12  is comprised of a pair of identical, planar, resilient switches  72 ,  74 , each of which is provided with a pair of identical boss pins  76 ,  78 . In the preferred embodiment switch  72  is mounted on handle plate  48 , and switch  74  is installed on handle plate  49 . The boss pins  76 ,  78  have short stems  80  extending perpendicularly from the bottom of radiused heads  82  that are engageable with the outermost ends  70  of the transfer pins  56 ,  58  and the walls of handle bores  66 ,  68 . Each switch  72 ,  74  is a wafer-thin plate fabricated of spring steel having an external arcuate or horseshoe-shaped portion  84  integrally connected with an internal, circular anchoring portion  86 . With the exception of a connecting segment  88 , the external portion  84  includes a pair of curved arms  90 ,  92  which are spaced apart by a gap  93  from the internal portion  86 . Each curved arm  90  or  92  is shaped so that a portion of the external periphery will follow the contour of underlying handle end plate  48 ,  49 . Each arm  90 ,  92  terminates in an end  94 ,  96  formed with a similarly sized throughhole  98  for receiving and retaining the short stem  80  of one of the boss pins  76 ,  78 . The internal portion  86  of each switch  72 ,  74  is formed with a circular neck  100  having a hole  102 . As seen in  FIG. 4 , each neck  100  is recessed in a respective handle plate bore  50 , and each hole  102  is aligned with jaw recess  42  so that the pivot pin  22  may pass therethrough. The internal portion  86  of the switch  72  is anchored between a head  25  of screw  24  and an external face of handle end plate  48 . The internal portion  86  of switch  74  is fixed between a head  31  of nut  30  and an external face of opposed handle end plate  49 . 
   As will be better appreciated below, each switch  72 ,  74  has a thin spring steel structure which effectively enables each arm  90  or  92  to temporarily deform and bend about a fulcrum point generally defined by the connecting segment  88  relative to the other arm  92  or  90 . 
   As will now be described through the coaction of the switching mechanism  12 , the pivot assembly  22  and the transfer pins  56 ,  58 , each jaw  18  or  20  may be selectively and rigidly linked or coupled to a selected handle  14  or  16 . 
   The described convertible retaining ring plier  10  is adapted for two operational modes which may be referred to as “the external ring mode” and the “internal ring mode”.  FIGS. 1 ,  5  and  12  particularly illustrate the external ring mode. In this mode, the jaw  18  is coupled to the handle  14  and the jaw  20  is coupled to the handle  16  so that squeezing of the handles towards each other will result in corresponding divergence of the jaws away from each other. To effect this coupling, the pins  56 ,  58  are positioned as illustrated in  FIG. 5 , and it will be seen that the pin  58  has its end  70  flush with upper handle end plate  48  as viewed in this figure and in  FIGS. 1 and 2 , and that the transfer pin  56  has its end  70  flush with handle end plate  49 . 
   It will also be seen that the boss pins  76  on the ends  94  of curved arms  90  of switches  72 ,  74  lie upon the ends  70  of the transfer pins  56 ,  58  and protrude from the handle end plate bores  66 . By virtue of their spring construction, the ends  94  and lower portions of curved arms  90  are temporarily bent upwardly. The other boss pins  78  on the switches  72 ,  74  are fully confined in bores  68  so that ends  96  of curved arms  92  lie flush on handle end plates  48 ,  49 . Switches  72  and  74  are designed to hold boss pins  76 ,  78  in alignment with handle end plate bores  66 ,  68 . 
   When it is desired to move from the external ring mode or position to the internal ring mode or position, the user places their right hand thumb upon the end  94  of switch  72  and their left hand forefinger on the end  94  of the other switch  74 . Then, gently squeezing the handles  14 ,  16  inwardly, equal finger pressure is applied to the raised spring ends  94  and protruding boss pins  76  on both sides of the pliers  10 . When the transfer pins  56 ,  58  are aligned with the respective bores  68  in handles  14 ,  16  and the boss pins  78  in those bores, the finger pressure will simultaneously push the transfer pins  56 ,  58  through jaw bores  54  such that transfer pin  58  disengages the handle end plate  48  and transfer pin  56  engages the handle end plate  48 . In this position shown in  FIG. 6 , boss pins  78  on ends  96  of curved arms  92  lie upon the ends  71  of transfer pins  56 ,  58  and protrude from handle end plates  48 ,  49  with a portion of the curved arms  92  bent temporarily upward. Boss pins  76  on ends  94  of curved arms  90  are recessed in handle bores  66  and rest on the ends  70  of transfer pins  56 ,  58  with curved arms  90  lying flat on each handle plate  48 ,  49 . 
   Referring now to  FIGS. 1 and 3 , a legend “EXT” is imprinted on the end plate  48  of the handle  16  adjacent to the bore  66  which is positioned to receive the transfer pin  58 , and that the legend “INT” is placed on the end plate  48  adjacent to the bore  68  which is positioned to receive the transfer pin  56 . In the external mode then, the projecting boss pin  76  at the bore bearing the legend “EXT” informs the user that the pliers  10  is in the “external ring mode”. Similarly, when the pliers  10  is in the “internal ring mode” the boss pin  78  will be projecting and provide that indication to the user. 
   The internal ring mode of the retaining ring pliers  10  is particularly illustrated in  FIG. 6 . For this mode, the transfer pin  56  of the jaw  18  is now engaged with the handle  16 , and the transfer pin  58  of the jaw  20  is now engaged with the handle  14 . 
   It should now be appreciated that the switching mechanism  12  performs two functions incidental to the operation of pliers  10 . One function is that the protruding boss pins  76 ,  78  coacting with a legend provided on the external handle surface provides a visual indication of the operating mode or position of the pliers  10 . Another function is the convenience of shifting the transfer pins  56 ,  58  to convert the pliers  10  to an alternative operational mode. During that shifting, the transfer pins  56 ,  58  are readily and simultaneously moved without need for an additional implement into their desired positions by applying finger pressure to the boss pins  76 ,  78  on the switches  72 ,  74 . The switches  72 ,  74  are made of spring steel and are intended to flex or deform to allow the boss pins  76 ,  78  to be pushed out of their respective handle bores  66 ,  68 . The switches  72 ,  74  also function to hold the boss pins  76 ,  78  in alignment with the bores  66 ,  68  depending upon the desired position of the pliers  10 . 
   While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only and should not be deemed limitative on the scope of the invention set forth with the following claims.