Abstract:
A wrench drive socket having jaws, actuated by a cam mechanism, facilitating the accommodation of a range of faceted work pieces is provided wherein adjustment of the distance between the jaws having V-shaped grips is accomplished by rotation of a knurled adjustment collar circumferentially disposed around a socket sleeve and fixed to an internally positioned jaw guide, the rotation of the jaw guide selectably positioning cam followers on the jaws against arch shaped cam profiles fashioned along the inside circumference of the socket sleeve, the sleeve being fixed to a centrally disposed socket body having an engaging hole to receive a drive shaft of a wrench such as a ratchet wrench. The adjustable drive socket provides advantages over the prior art including simplified construction, convenience of use, durability, effectiveness, and cost and weight reduction through the elimination of a plurality of sockets having fixed sizes.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of wrench tools. More particularly, this invention is directed to a wrench drive socket with adjustable jaws by means of a cam actuated mechanism. 
     BACKGROUND OF THE INVENTION 
     Various types of adjustable wrench drive sockets having adjustable jaws to grip a range of sizes or diameters of bolts, nuts or other fasteners have been provided with varying mechanisms, often of complex design, for tightening various forms of jaws up against a work piece fastener and with varying degrees of acceptance. Adjustable drive sockets typically have an annularly mounted mechanism wherein a rotatable element is rotated by an operator to adjust the jaws inwardly or outwardly to match the size of the work piece fastener. One such prior art socket taught by Lee (U.S. Pat. No. 5,996,446) is typical of adjustable jaw mechanisms wherein jaw elements have detent features, in this case teeth, selectably engaged by rotation of a control element defining predetermined fixed distances between the jaws. The detent features typically are intended to lock the jaw distance, and hence the size, such that the jaw spacing remains fixed as load is applied to the socket, else slippage of the jaw positioning can occur. Slippage manifests as an opening of the jaws causing, at minimum, poor fit of the socket to a work piece, inefficient load transfer to the work piece, risk of damage to the work piece mating surfaces and/or the socket and possible injury to the user upon sudden disengagement. Configurations requiring jaw locking mechanisms further necessitate that the locking mechanism bear much of the transfer load therefore requiring substantial load bearing capacity as provided by costly harden steel components. Hence, the load capacity of adjustable sockets is often limited as compared to a standard solid socket. In any case, the inherent characteristics of such mechanisms result in the socket having a propensity to increase the jaw spacing under load. 
     An object of using an adjustable socket is to minimize the number of sockets required in a tool set. The size adjustment range of the typical adjustable socket is limited. Typically, adjustable sockets have a relatively small size adjustment range thereby necessitating a number of adjustable sockets, albeit fewer than required in a fixed socket set. 
     In view of the load, grasping force, size, and range limitations of the typical prior art socket, the herein disclosed invention is provided to overcome the many disadvantages. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a new type of adjustable wrench drive socket having a cam actuated mechanism and features to simplify the structure and construction, advance its convenience of use, durability and effectiveness while accommodating a wide and continuous range of faceted work piece sizes. The simplicity of the socket minimizes the size and the number of elements as well as the manufacturing cost. 
     The present invention is a wrench drive socket having adjustable jaws, actuated by a cam mechanism, facilitating the accommodation of a range of sizes of faceted work pieces is provided wherein adjustment of the distance between the jaws having V-shaped grips is accomplished by rotation of a knurled adjustment collar circumferentially disposed around a socket sleeve and fixed to an internally positioned jaw guide, the rotation of the jaw guide selectably positioning cam followers on the jaws interacting with and against arch shaped cam profiles fashioned along the inside circumference of the socket sleeve, the sleeve being fixed to a centrally disposed socket body having an engaging hole to receive a drive shaft of a wrench such as a ratchet wrench. 
     In use, load is transferred from a provided wrench, to the socket body, to the sleeve cam profiles, to the jaws and then to an engaged provided work piece. The user first positions the socket over a provided work piece, then rotates the adjustment collar to engage jaws against the work piece. As torque is applied to the socket by means of the provided wrench or other drive tool, load is transferred through the cam mechanism arranged such that increasing torque levels result in a load vector forcing the jaws of the socket together to increase the grasp of the work piece. The interaction of cam profiles with cam followers on the jaws further provide continuous adjustment of the distance between the jaws hence providing infinite size adjustment throughout the range of the socket. The cam profiles are disposed so as to facilitate both clockwise and counterclockwise application of torque. The cam actuation features provide a means to significantly reduce the risk of slippage and disengagement of the socket from a work piece under torque by means of the jaw tightening action thereby also reducing the risk of damage to the work piece. The cam actuation features further provide for a small and compact design while capable of handling higher torque load than available in a similar sized adjustable socket. 
     It will be appreciated that many other additional benefits are provided by the cam actuation mechanism. The adjustable drive socket provides advantages over the prior art including simplified construction, convenience of use, compact size, durability, effectiveness, and cost and weight reduction through the elimination of a plurality of sockets having fixed sizes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate embodiments of the invention and, together with the description, serve to explain the features, advantages, and principles of the invention. 
         FIG. 1  is a top perspective view of an embodiment of the adjustable socket according to the present invention showing the knurled adjustment collar and the centrally disposed engaging hole for mating with a square end fitting of a wrench. 
         FIG. 2  is a bottom perspective view of the adjustable socket illustrating the selectably adjustable jaws by means of rotation of the knurled adjustment collar relative to the body of the socket. 
         FIG. 3  is a top plan view of the present invention showing the concentric disposition of the wrench engaging hole and the circumferentially disposed adjustment collar. 
         FIG. 4  is a bottom plan view of the adjustable socket showing the inner cam surfaces, adjustable jaws and compression spring forming the work piece grip portion for grasping a provided faceted work piece such as a bolt or nut. 
         FIG. 5  is an exploded view of the adjustable socket showing the spatial relationship and connectivity of the elements of the socket. 
         FIG. 6  is a cross section view taken on Line  6 - 6  of  FIG. 3  illustrating the internal elements of the adjustable socket according to the present invention wherein the distance between the jaws is responsive to the rotation of the knurled adjustment collar. 
         FIG. 7  is a cross section view taken on Line  7 - 7  of  FIG. 6  illustrating the socket body secured centrally within and to the socket cylindrical sleeve by means of pins so arranged as to permit rotation of the knurled adjustment collar around the socket cylindrical sleeve. 
         FIG. 8  is cross section view taken on Line  8 - 8  of  FIG. 3  showing the through pinning of the knurled adjustment collar to the inwardly, centrally and concentrically positioned jaw guide wherein the collar pin passes through a horizontally disposed collar slot in the socket cylindrical sleeve such that rotation of the collar necessarily rotates the jaw guide within the socket cylindrical sleeve. 
         FIG. 9  is a cross section view taken on Line  9 - 9  of  FIG. 8 . of the present invention illustrating details of the horizontally disposed collar slot wherein the knurled adjustment collar is adjustable within a 180 degree rotational range. 
         FIG. 10  is a bottom view of the present invention taken on Line  10 - 10  of  FIG. 8  showing the adjustable socket with the jaws in the maximum open configuration. 
         FIG. 11  is a similar view as in  FIG. 10  showing the adjustable socket with the jaws adjusted to a mid-range opening configuration. 
         FIG. 12  is a similar view as in  FIG. 10  showing the jaws of the adjustable socket in the minimum opening configuration. 
         FIG. 13  is a perspective view of the adjustable socket according to the present invention attached to the engaging drive shaft of a ratchet wrench handle and further poised for engaging a faceted work piece between the jaws of the adjustable socket. 
         FIG. 14  is a perspective view of the adjustable socket engaged around a faceted work piece and showing a user&#39;s thumb and finger in position grasping the knurled adjustment collar so as to selectably dispose the jaws to fully engage the work piece by means of rotation of the ratchet wrench handle so as to position the V-grips of the jaws to compliment the work piece facets and by adjusting the distance between the jaws. 
         FIG. 15  is a cross section view taken on Line  15 - 15  of  FIG. 14  showing the user finger and thumb positioning to affect the rotation of the knurled adjustment collar around the socket sleeve so as to selectably adjust the distance between the adjustable jaws. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. Referring now in greater detail to the various figures of the drawings wherein like reference characters refer to like parts, there is shown in a perspective view at  10  in  FIG. 1 , a new type of adjustable wrench drive socket facilitated by a cam mechanism. 
     Referring now to  FIGS. 1 and 2  illustrating a top and a bottom perspective view respectively of the adjustable wrench drive socket  10  according to the present invention comprising a knurled adjustment collar  14  circumferentially surrounding a socket sleeve  12  wherein the knurled adjustment collar  14  is fixed by collar pin  20  through collar pin bore  38  and a horizontally and circumferentially disposed slot  23  in the cylindrical sleeve  12  to a jaw guide positioned concentrically within the sleeve  12  and receiving a first and second jaw  26  and  28  each having a V-shaped grip  48  and  50  and a cam follower  44  and  46  surface respectively disposed and compression spring biased to contact arch-shaped cam profile surfaces  22  and  24  that form the lower portion of the inside surface of sleeve  12 . The jaws  26  and  28  are positioned opposingly and follow the sleeve cam profile surfaces  22  and  24  in response to a rotation of the knurled adjustment collar  14  around and relative to the sleeve  12 . The cam profile surfaces  22  and  24  are the same and disposed with the bottom of the arches touching therefore resemble mirrored arches wherein the sleeve  12  wall thickness is at a minimum at the top of the arch and the wall thickness is at a maximum at the intersection of the cam profile surfaces. Being symmetrically shaped arch profiles, the cam profiles are centered along a diameter of the sleeve  12 . Rotating the circumferential position of the knurled adjustment collar  14  necessarily repositions the cam followers  44  and  46  to complimentary positions along the profiles moving the jaws  26  and  28  closer together as the sleeve  12  wall thickness increases responsive to the repositioning of the contact point between the jaw cam followers  44  and  46  lower towards the bottom end along the arch-shaped cam profiles. Maximum distance between the jaw V-shaped grips  48  and  50  is attained when the jaw cam followers  44  and  46  are positioned at the top of the cam profiles  22  and  24 . The socket sleeve  12  is fixed to the socket body  18  concentrically disposed within the top portion of the socket sleeve  12 , the top portion of the sleeve  12  having a cylindrical inner surface thereby forming an annular opening to receive the socket body  18 . The socket body  18  having a top and bottom surface, the top surface comprises an engaging hole  16  for receiving the drive shaft of a wrench or other tool. 
     In  FIG. 3 , a top plan view of the adjustable socket, the socket body  18  is illustrated, being fashioned from a solid cylindrically shaped element and fitting within the sleeve  12 , has the drive shaft engaging hole  16  centrally located such that the socket  10  mounts concentrically to a provided drive shaft. The knurled adjustment collar  14  is disposed in a manner so as to provide sufficient clearance between the outside surface of the sleeve  12  and the inner cylindrical surface of the collar  14  to allow free rotational movement of the collar  14  around the sleeve  12 . 
     The jaw and cam mechanisms are more clearly seen in the bottom plan view of  FIG. 4 . First and second jaws  26  and  28  each having a cam follower  46  and  48  disposed opposite V-shaped grips  48  and  50 , have their respective cam followers  46  and  48  biased against the sleeve  12  cam profile surfaces  22  and  24 . The jaws  26  and  28  are free to slide within a guide slot  56  of the jaw guide  32  being biased outwards against the cam profile surfaces  22  and  24  by a guide compression spring  30 . The jaw guide  32  is centrally rotatable within the sleeve  12  such that rotation of the jaw guide  32  relative to the sleeve  12  repositions the jaw cam followers  46  and  48  at selected complementary positions along the arch shaped profiles. The knurled adjustment collar  14  surrounding the outside circumference of the sleeve  12  and being pinned through a horizontally disposed slot in the sleeve  12 , thereby facilities a user to select the distance between the V-shaped grips  48  and  50  of the jaws  26  and  28  by rotating the collar  14  around the sleeve  12 . 
       FIG. 5  provides a perspective exploded view according to the present invention illustrating the spatial relationship between the various elements of the socket. Beginning from the top end of the socket, the knurled adjustment collar  14 , being cylindrically shaped, has a knurled outside surface for user grip and has a smooth cylindrical surface on the inside commensurate with free rotation around the outside surface of sleeve  12 . The collar pin  20  is mounted in collar pin bore  38  penetrating through the collar  14 . Collar pin  20  is received by jaw guide collar pin receiving bore  40  and restricts the rotational range of the knurled adjustment collar  14  around the sleeve  12  by means of the collar pin slot  42  horizontally and circumferentially disposed in the sleeve  12 . The collar pin slot  42  has a centerline at a location corresponding to the bottom of the arch shaped cam profile surfaces  22  and  24 . The length of the collar pin slot  42  is engineered such that the knurled adjustment collar  14  may rotate 90 degrees in either direction from the center point of the collar pin slot  42  thereby providing adjustment of the jaws  26  and  28  to be positioned at any point along the cam profiles  22  and  24 . 
     The top portion of sleeve  12  has a cylindrically shaped surface suitable for receiving the jaw guide  32  being a cylindrically shaped element with jaw guide slot  58  in the bottom of the jaw guide  32  and through the diameter. The jaw guide slot  56  is fashioned to accommodate jaw guide slot followers  52  and  54  forming the top of each jaw  26  and  28 . The contours of the jaw guide slot  56  and the jaw guide slot followers  52  are selected to capture the jaw within the guide whilst permitting free movement within the slot  56 . A jaw compression spring  30  is disposed between the jaw guide slot followers  52  and  54  for biasing the jaws  24  and  26  outwardly. The opposing jaw spring bosses  58  and  60  assist to retain the jaw compression spring  30  between the jaws. The inside surface of the bottom portion of sleeve  12  being the arch shaped cam profiles  22  and  24  necessarily protrude inwardly towards the central axis of the sleeve  12  thereby provide arch shaped cam profile top side surfaces  62  and  72  perpendicular to the central axis defining the transition between the top and bottom portions of the sleeve  12 . These profile top side surfaces  62  and  72  confine the bottom surface of the jaw guide  32  while allowing the guide  32  to rotate within the sleeve  12 . The top surface of the jaw guide  32  also being flat completes the cylindrical shape of the guide  32  and is suitable for receiving the jaw guide compression spring  36  disposed between the guide  32  and the socket body  14  disposed above the guide  32  within the top portion of the sleeve  12 . The socket body  14  has body securing pin receiver bores  34  within the outside circumference of the socket body  14  for retention of body securing pins  64 . The receiver bores  34  align respectively with sleeve body securing pin bores  66  in the sleeve  12 . The body securing pins  64  have a length so engineered such that when the pin is in place, the distal end of the pin does not protrude beyond the outside surface of the sleeve  12  thereby eliminating interference with surrounding knurled adjustment collar  14 . The socket body  14  being a solid cylindrical shape is disposed with the top surface being flush with the top of the socket  10  and has a height to provide sufficient clearance between the bottom of the body  14  and the top of the jaw guide  32  to accommodate the guide compression spring  36 . 
     It will be appreciated that the socket elements are interlocked in such as manner as to permit easy assembly beginning with the jaws and jaw guide components fitted together, then inserted through the top of the sleeve, the guide compression spring fitted with the body inserted and pinned, finally the knurled adjustment collar  14  restricting the body securing pins being pinned through to the jaw guide. 
       FIG. 6  being a cross section view taken along Line  6 - 6  of  FIG. 3  shows the assembled socket with the jaws  26  and  28  being captured by the jaw guide  32  and jaw cam followers  48  and  50  biased against the arched cam profile surfaces  22  and  24  of the sleeve  12  by compression spring  30 . 
     Referring also to  FIG. 7 , a cross section view taken along Line  7 - 7  of  FIG. 6 , details of the socket body  18  positioning within the sleeve  12  are illustrated. The radially disposed receiving bores  34  being aligned with sleeve body pin bores  66  together provide retention of the body securing pins  64  and the knurled adjustment collar  14  further confines the body securing pins  64 ; however, the proximate end of the receiving bores  34  form opens into the drive shaft engaging hole  16  necessitating the body securing pins  34  to fit snugly into the receiving bores  34 . Therefore the body securing pins  64  are depicted as roll pin type pins that press outwardly on the bore, other pin types may also be used that provide a compressive fitting within the bore. The embodiment as illustrated shows four body securing pin bores and pins; however, any number may be used. Four bores and pins disposed at 90 degree increments facilitate manufacturing and provide detents in the sides of the drive shaft engaging hole  16  in the top of the socket body  18  formed by the proximate open ends of the body securing pin bores  34 . The detent features are suitable for accepting complementing locking features on a provided wrench drive shaft. 
     Referring now to  FIG. 8 , a cross section view taken along Line  8 - 8  of  FIG. 3 , and  FIG. 9 , a cross section view taken along Line  9 - 9  of  FIG. 8 , details of the cam actuated jaw adjustment mechanisms are more clearly illustrated. The jaws have identical construction. The jaw guide slot  56  of the jaw guide  32  captures the jaw guide slot followers  52  and  54  by means of contours engineered to conform with complementary contours of the jaw recessed neck  74  and  78  of the jaws  26  and  28 . The jaws  26  and  28  may slide within the jaw guide slot  56  with the V-shaped grip surfaces  48  and  50  facing one another for grasping a facetted work piece. The collar pin receiving bore  40  is radially disposed in the outer circumference of the jaw guide  32  perpendicular to the jaw guide slot  56  and aligned with the collar pin slot  42  in the sleeve  12  and further aligned with the knurled adjustment collar pin bore  38 . The collar pin  20  when pressed into the aligned bores secures the knurled adjustment collar  14  to the jaw guide  32 . The collar pin slot  42  restricts the rotation range of the knurled adjustment collar  14  and hence the rotational position of the jaw guide  32  within the sleeve  12 . The cam profile top side surfaces  62  and  72  are clearly visible in  FIG. 8  as the cross section view is taken along the diameter where the bottom of the arch shaped cam profiles of the bottom portion of the sleeve intersect thereby providing a maximum wall thickness of the sleeve and hence the cam profile top side surfaces  62  and  72 . The jaw guide  32  rests on top of the these surfaces and may slide over these surfaces in rotation; however, guide compress spring  36  disposed between the socket body  18  and the jaw guide  32  is engineered so as to provide sufficient friction between the jaw guide  32  and the cam profile top side surfaces  62  and  72  to maintain a rotational position selected by a user. 
       FIG. 10 , taken along Line  10 - 10  of  FIG. 8  illustrates the socket configured with the jaws  26  and  28  with the maximum distance between the jaws representing the largest faceted work piece capacity. The sleeve cam profiles  22  and  24  are clearly visible showing each having an identical arch shape profile wherein the profiles intersect at the base of the arch. Any suitable arch shape may be used including equilateral, parabolic, and lancet shaped arches with the base or springing line span of the arch having a length less than the inside diameter of the opening in the bottom section of the sleeve. In order to achieve a grip equally tight throughout the range of the socket, the arch shape of the cam profile must present a substantially constant pressure angle with respect to the jaws throughout the full adjustment range of the socket. The top of the arch shaped profile is disposed at the inside diameter of the sleeve therefore the wall thickness of the bottom portion of the wall is at a minimum. The base of the arch shaped profile is disposed at a diameter perpendicularly aligned with the center of the collar pin slot of the sleeve, and defines the thickest portion of the bottom portion of the sleeve. When viewed from the bottom of the socket, the arch shaped profiles are disposed in a mirrored orientation. The shorter base lengths provide greater range of adjustment of the distance between the jaws; however, the jaw dimensions limit the base length. 
       FIG. 11  is similar to  FIG. 10  excepting the rotational position of the jaw guide  32 . In  FIG. 10 , the knurled adjustment collar  14  is positioned at the center of the rotational range such that the jaw cam followers  44  and  46  are disposed at the top of the arch of the cam profiles  22  and  24  and hence providing the maximum distance between the V-shaped grips  48  and  50  of the jaws  26  and  28 . The facetted work piece accommodated in  FIG. 10  is therefore larger than the facetted work piece illustrated in  FIG. 11  wherein the jaw guide  32  has been rotated approximately 45 degrees from the central position as shown in  FIG. 10 . As the jaw cam followers  44  and  48  interact with the cam profile  22  and  24  surfaces and travel away from the top of the cam profiles  22  and  24 , the sleeve  12  walls thicken and the jaws  26  and  28  are forced towards one another. It will be appreciated that as the sleeve  12  rotates as load is applied by a provided wrench, load is transferred to the jaws  24  and  26  through the cam profiles  22  and  24  by means of the jaw cam followers  26  and  28 . Having a provide facetted work piece positioned between the V-shaped grips  48  and  50  of the jaws  24  and  26 , load is transferred to the work piece. There also exists a load vector between the jaw cam followers  26  and  28  and the cam profile  22  and  24  surfaces that drives the cam followers  26  and  28  further down the cam profiles resulting in a tightening action on the facetted fastener. This tightening feature of the present invention provides an advantage over the prior art wherein prior art drives tend to loosen grip on the work piece when load is applied to the drive. 
       FIG. 12  shows the jaw guide  32  rotated 90 degrees from the center line of the guide pin slot  42  of the sleeve  12  representing the smallest distance between the jaws  26  and  28 , and hence the smallest facetted work piece accommodated. In this configuration the knurled adjustment collar  14  is positioned at either end of the guide pin slot  42 . Note that depending upon the rotational load direction required in a particular use, the user is best advised to select the cam positions such that the jaws tightened upon the fastener when as load is applied. This selection is made by rotating the knurled adjustment collar  14  in the appropriate direction. 
     The method of operation of the wrench drive socket according to the present invention is dependent upon the direction of torque required to be applied to a provided work piece. Note that depending upon the rotational load direction required in a particular use, the user is best advised to select the cam positions such that the jaws tightened upon the fastener when as load is applied. This selection is made by rotating the knurled adjustment collar  14  in the appropriate direction. If clockwise torque is required, a counterclockwise rotation of the collar  14  is desired. The converse is also true. 
       FIG. 13  illustrates the wrench drive socket  10  according to the present position fitted to a drive shaft of a ratchet wrench  68  and poised over a work piece  70 . The user places the socket onto the work piece  70 , as in  FIG. 14 , by twisting the collar clockwise or counterclockwise relative to the sleeve  12  until the socket  10  accepts the work piece  70 . The jaw spacing is now sufficient to accommodate the work piece  70 . With the knurled adjustment collar  14  grasped by the user between thumb and opposing finger as in  FIG. 15 , to apply clockwise load to the fastener, the user rotates the collar  14  counterclockwise relative to the sleeve  12  and body  18  to tighten the jaws against the work piece  70 . 
     The nature of the construction materials for each of the elements of the tool correspond to the load and wear requirements for each element. Note that the socket has points of interaction between a work piece and the jaw V-shaped grip surfaces, the jaw cam follower and cam profile surfaces, and the socket body and a drive shaft. Consequently any construction material may be used that is suitable to accept the loads required. 
     While embodiments of this invention have been illustrated and described, variations and modifications may be apparent to those skilled in the art. Therefore, we do not wish to be limited thereto and ask that the scope and breadth of this invention be determined from the claims which follow rather than the above description.