Abstract:
An accessory chuck for utility vehicles having an upper jaw and a lower jaw slidably suspended therefrom and movable by turning a threaded rod supported by the upper jaw. Suspending members are pivotally attached to the lower jaw and to pairs of carrying nuts that ride on the threaded rods. Turning the threaded rod from either end causes each pair of carrying nuts to ride closer or farther apart, depending on the direction the rod is turned. As the carrying nuts move, the suspending members raise or lower the lower jaw to a releasing or a gripping position, respectively.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to utility vehicles having mechanisms for attaching accessories. More specifically, the present invention relates to a means for attaching accessories such as forks, buckets, blades, and the like, to utility vehicles. 
     2. Discussion of Background 
     In the field of utility vehicle attachment mechanisms, the selection of accessories and method for attaching them is quite varied. See for example, U.S. Pat. No. 3,269,570 issued to Wallberg, U.S. Pat. No. 4,607,997 issued to Asano, and U.S. Pat. No. 3,528,580 issued to Carliss. Of importance is the ability of the utility vehicle carriage to quickly but safely secure the accessory. Some accessory chucks, if they fail, will fail in such a way that the accessory becomes detached. In others there are no convenient means for changing the accessory without involving the operator placing his or her hands between the major component and the vehicle where injuries can occur. 
     There is a need for a simpler, safer, more efficient and versatile mechanism for attaching accessories to a utility vehicle. 
     SUMMARY OF THE INVENTION 
     According to the major aspects of the present invention, the accessory chuck comprises an upper jaw, a lower jaw in slidable contact with the upper jaw, and a means for moving the upper and lower jaws with respect to each other from an accessory-releasing position to an accessory-gripping position. The upper jaw is attached to the vehicle. The lower jaw, unattached, is guided into interleaved relationship with the upper jaw, raised by the moving means. The moving means comprises suspending members pulled by carrying nuts riding on a threaded rod. The rod is turned at one end of the chuck by the operator. 
     The accessory chuck provides ease in the attachment and removal of accessories to a utility vehicle. The accessory chuck may be backfitted to any standard utility vehicle by attaching it to the vehicle&#39;s carriage by any suitably strong attaching means, such as bolting or welding, or incorporated into an improved vehicle in lieu of the standard utility vehicle carriage. If integrated into the carriage of the vehicle, there is no loss of lift capacity or leverage. Because of simplicity of design of the accessory chuck, maintenance is simplified and operation is more efficient. 
     Another feature of the present invention is the full width upper and lower rails that grip the accessory. These rails do not require precise positioning of the vehicle for gripping and indeed the vehicle may want to grip the accessory in a side-shifted position. 
     Another feature of the present invention is its symmetry which enables an operator to raise and lower the lower jaw from either side to simplify the attachment and removal of accessories to the utility vehicle. 
     Yet another feature of the accessory chuck is the positive control of the gripping and release of attachments; the accessory, once in the gripping position, will not fail to the releasing position. 
     Reference is now made in detail to the present preferred embodiment of the invention, an example of which is given in the accompanying drawings. 
    
    
     A BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
     FIG. 1 is a side view of a portion of a utility vehicle disengaging a fork according to an embodiment of the present invention; 
     FIG. 2 is a side view of a portion of the utility vehicle of FIG. 1 according to the present embodiment with the fork engaged and locked; 
     FIG. 3 is a front view of an accessory chuck in the gripping position according to the present embodiment; 
     FIG. 4 is a front view of the accessory chuck in the releasing position according to the present embodiment; and 
     FIG. 5 is a bottom view of the accessory chuck according to the present embodiment. 
     FIG. 6 is a perspective, detailed view of the means for moving the lower jaw of an accessory chuck according to the present embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, in FIG. 1 the front portion of a utility vehicle 10 is shown in profile with utility vehicle front 12, wheel 14, vertical member 16 and standard carriage 18. Standard carriage 18 is attached to vertical member 16 and is of the type found on many utility vehicles. Vertical member 16 has a mechanism for lifting a standard carriage 18. A chuck 22 for allowing the gripping of accessories is attached to carriage 18 in a manner described more fully below. In FIG. 1, the utility vehicle 10 is approaching an accessory 26, namely a fork as shown, with accessory chuck 22 shown in releasing position. Fork 26 has an upper hook 28 and a lower hook 30. 
     Accessory chuck 22 is attached to carriage 18 by bolting or welding or any rigid means of attachment when an existing utility vehicle 10 is to be backfitted with accessory chuck 22. Alternatively, carriage 18 may be eliminated in the manufacture of utility truck 10 and accessory chuck 22 fastened directly to vertical member 16. Also, although accessory chuck 22 is illustrated in the attachment of fork 26, most accessories that will fit the standard carriage 18 will fit the accessory chuck 22. 
     From the side view of accessory chuck 22 in FIG. 1 can be seen an upper jaw 32 with an upper rail 34 and bolt head 36. From FIG. 2, lower jaw 38 with lower rail 40 can also be seen below upper jaw 32. In the present preferred embodiment, only upper jaw 32, and not also lower jaw 38, is attached to carriage or vertical member 16 but it will be seen that the reverse arrangement will also be operative although somewhat less satisfactorily. 
     In FIG. 2, utility vehicle 10 has moved slightly forward and accessory chuck 22 of utility vehicle 10 has thereby engaged fork 26, with upper rail 34 gripping the upper hook 28 and lower rail 40 gripping lower hook 30. Fork 26 is thus locked into place ready for use. 
     Fork 26 is locked into place by first positioning utility vehicle 10 so that accessory chuck 22 is between upper and lower hooks 28, 30, respectively, of fork 26, raising upper jaw 34 by raising carriage 18 on vertical member 16 until upper rail 34 engages upper hook 28, then turning bolt head 36 until lower rail 40 engages lower hook 30. 
     Referring now to FIGS. 3 and 4, front views (which are symmetric to rear views) of accessory chuck 22 in the releasing position and the gripping position, respectively, it will be seen that chuck 22 comprises a horizontal member 50 and several spaced apart extensions depending therefrom: a left and a right jaw guide 52, 52&#39;,a left and a right interior jaw guide 54, 54&#39; and a center jaw support 56. Lower jaw 38 comprises a horizontal member 60 and also several extensions: namely, a left and right jaw guide, 62, 62&#39;. Left jaw guide 62 of lower jaw 38 slides vertically between left jaw guide 52 and interior jaw guide 54 of upper jaw 32, at least one face of left lower jaw guide 62 in contact with a face of left jaw guide 52 and interior jaw guide 54. Correspondingly, right jaw guide 62&#39; of lower jaw 38 slides vertically between right jaw guide 52&#39; and right interior jaw guide 54&#39; of upper jaw 32, at least one face of right lower jaw guide 62&#39; in contact with a face of right jaw guide 52&#39; and right interior jaw guide 54&#39;. Upper rail 34 runs the length of horizontal member 50 of upper jaw 32; lower rail 40 runs the length of horizontal member 60 of lower jaw 38. Between left interior jaw guide 54 and center jaw support 56 is defined a first space A; between right interior jaw guide 54&#39; and center jaw support 56 is a second space B. 
     Helping to guide the sliding of lower jaw 38 with respect to upper jaw 32 are tongue-and-groove interconnections, as best seen in FIG. 5, where lower jaw 38 is shown as having the &#34;tongue&#34; and upper jaw 32 having the &#34;groove&#34;, but it will be apparent that the reverse arrangement is equivalent to that shown. 
     The mechanism for moving the upper and lower jaws 32, 38, with respect to each other comprises a threaded rod 70 having two pair of carrying nuts 72, 74 riding thereon and two pair of suspending members 76, 78 (each suspending member is in duplicate on each carrying nut as seen in FIG. 6) pivotally connecting the carrying nuts 72, 74 and lower jaw 38. 
     Rod 70 extends the width of upper jaw 32, passing through holes in left jaw guide 52, left interior jaw guide 54, center jaw support 56, right interior jaw guide 54&#39; and right jaw guide 52&#39;. Rod 70 passes through slots 86, 86&#39; in left and right jaw guide 62, 62&#39;, respectively, of lower jaw 38. Rod 70 will be toward the bottom of slots 86, 86&#39; of left and right jaw guides 62, 62&#39; of lower jaw 38 when chuck is in the releasing position (FIG. 4) and toward the top of slots 86, 86&#39; when chuck is in the gripping position (FIG. 3). Rod 70 terminates at the right end in bolt head 36 and the left end in bolt head 36&#39;. Turning bolt head 36 or bolt head 36&#39; will operate accessory chuck 22. 
     In spaces A and B are arranged carrying nuts 72, 74 and suspending members 76, 78. As seen in FIG. 6, rod 70 in these regions has zones of left and right hand threads. The portion of rod 70 in Space A has right hand threads on the left half of that portion and left hand threads on the right hand portion. Similarly, in Space B, the left half of the portion of rod 70 has right hand threads and the right half of the portion has left hand threads. As rod 70 is turned clockwise, first pair of carrying nuts 72 will ride toward each other and second pair of carrying nuts 74 will ride toward each other (FIG. 6). Turning rod 70 counterclockwise will cause first and second pair of carrying nuts 72, 74 to ride apart. It will be apparent that a reverse arrangement of threads will work in an equivalent manner to that shown. As carrying nuts 72, 74 move, suspending members 76, 78 are free to pivot about their respective attachments to carrying nuts 72, 74 and horizontal member 60 of lower jaw 38. At the point of extreme separation of carrying nuts 72, 74, suspending members 76, 78 hang straight down and lower jaw 38 has slid vertically downward to its gripping position. As carrying nuts 72, 74 move closer together, they pull one end of suspending members 76, 78 horizontally as the other end, the end pivotally attached to horizontal member 60, remains in place. Thus, lower jaw 38 is thereby lifted. Lower jaw 38 is limited in its movement by the length of interior jaw guides 54, 54&#39; which stop upward movement of horizontal member 60 of lower jaw 38, as shown in FIG. 4. 
     Accessory chuck 22 is preferably made of steel or other durable material of suitable thickness, preferably approximately one and one-half inches thick. The upper and lower jaws 32, 38, are preferably made of a single piece of material, milled to tolerance. A hydraulic connection to bolt heads 36, 36&#39; can be made to allow remote release and gripping of accessories. If done remotely, it is preferable to incorporate limit switches to verify the accessory is in the gripping position. 
     The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable one skilled in the art to best utilize the invention in various embodiment and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.