Abstract:
Armrests of a vehicle seat include vertical brackets having legs located in vertical guide slots defined by support structure. A cam plate is rotatably mounted between the brackets for movement between a lock position, wherein it establishes a tight frictional engagement between opposed surfaces of the legs and guide slots, and a release position wherein it permits the legs to move freely in the slots.

Description:
This application is a continuation of application Ser. No. 649,878, filed Sept. 13, 1984 abandoned 4/28/86. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to vehicle seats and more particularly relates to adjustment mechanisms for the armrests of such seats. 
     It is important that operators of industrial and utility equipment be able to quickly adjust the armrests of the seats thereof so as to accommodate operators of various sizes. Heretofore, mechanisms permitting adjustments of the armrests have been relatively complex. 
     Now there is provided an armrest adjustment mechanism of simple construction. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a novel vehicle seat armrest adjustment mechanism. 
     An object of the invention is to provide a mechanism of simple construction for permitting a vehicle armrest to be easily adjusted. 
     A further object of the invention is to provide a mechanism for permitting a vehicle armrest to be placed in an infinite number of positions in its range of movement. 
     Yet a more specific object of the invention is to provide an armrest adjustment mechanism including a lever-operated cam movable between locked and unlocked positions for respectively holding an armrest in or releasing it from a selected or previously selected position. 
     These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a vehicle seat assembly including an armrest with which an adjustment mechanism constructed in accordance with the principles of the present invention is particularly adapted for use. 
     FIG. 2 is a front elevational view of the left-hand armrest and showing the adjustment mechanism. 
     FIG. 3 is a side view taken along line 3--3 of FIG. 2. 
     FIG. 4 is a top view taken along line 4--4 of FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a rear portion of a vehicle 10 including an operator&#39;s seat assembly 12 including a bottom cushion 14, a back cushion 16 and right- and left-hand armrests 18 and 20. The armrests 18 and 20 are separate from the cushions 14 and 16 and are mounted in substantially similar fashion with only the mounting for the armrest 20 being shown and described for the sake of brevity. 
     Referring now to FIGS. 2-4, it can be seen that the tractor 10 includes a support structure 22 located outwardly of the armrest 20 and including a vertical, fore-and-aft extending wall 24 and a vertical rectangular plate 26 mounted to the wall 24 by a plurality of cap screws 28 and held in spaced parallel relationship to the wall by a plurality of spacer rings 30 respectively received on the cap screws 28 between the plate and wall. The cap screws 28 are spaced sufficiently away from vertical front and rear edges of the plate 26 that an undisturbed gap is left between front and rear portions of the plate and the wall to thereby establish front and rear vertical guide slots 32 and 34, respectively, having a purpose described hereinbelow. 
     The armrest 20 includes an elongate pad 36 which is L-shaped in end view and includes integral horizontal and vertical legs 38 and 40. The pad legs 38 and 40 are secured to a rigid form including a vertical plate portion 42 which faces and is parallel to the plate 26. A latch mechanism 44 for releasably fixing the armrest in selected positions on the rectangular abutment plate 26 is mounted to the plate portion 42 of the pad form. 
     Specifically, the latch mechanism 44 comprises spaced, front and rear, elongate brackets 46 and 48, respectively, which are formed from channel members and are arranged vertically on the plate portion 42 so as to open towards each other with respective first legs 50 and 52 being welded to the plate portion 42 and with respective second legs 54 and 56 being received in said front and rear guide slots 32 and 34. Respective bight portions 58 and 60 of the brackets 46 and 48 extend perpendicular to the plate portion 42 and extending through horizontally aligned holes in the bight portions is a long cap screw 62 having a nut 64 on one end for holding it in place. A round tube 66 having a length equal to the distance between the bight portions 58 and 60 of the brackets 46 and 48 is received on the cap screw 62 for rotating thereabout. A cam plate 68 is welded to the tube 66 at a location midway between its opposite ends. The cam plate has a flat peripheral surface 70 which is seated against a vertical abutment surface defined by one side of the plate 26 when the cam plate is in a lock position, as shown in solid lines in FIG. 2. The surface 70 is spaced from the axis of the cap screw 62 such that an interference fit exists between the cam and abutment surface when the cam plate is in its lock position. It is noted that when cam plate is in its lock position, the cap screw 62 is deflected away from the plate 26 while the brackets 46 and 48 are deflected toward each other. In this way the cam plate 68 is resiliently biased against the plate 26 and thus causes the confronting surface portions of the plate 26 and the bracket second legs 54 and 56 to be held in tight frictional engagement with each other so as to hold the armrest 20 in a desired vertical location. The armrest 20 may be released for vertical movement to another position by rotating the cam plate 68 clockwise from its lock position to a release position shown in dashed lines in FIG. 2. The flat surface 70 of the cam plate 68 is then moved away from the plate 26 and the bracket legs are then free to move vertically within the guide slots 32 and 34. To aid in the movement of the cam plate 68, a hand lever 72 is fixed to the plate 68. Specifically, the hand lever 72 is formed from a bent rod which, as viewed in FIG. 2 with the cam plate 68 in its lock position, includes a vertical section 74 welded to the cam plate and extending to a location below the vertical pad leg 40, an intermediate downwardly and outwardly inclined section 76 and a fore-and-aft extending end section 78. It will be appreciated then that an operator desiring to vertically adjust the armrest 20 needs only to insert his hand in the gap between the seat cushion 14 and the bottom of the armrest 20 and grab and pull up on the hand lever 72. The armrest 20 may then be adjusted and again locked in place by pushing down on the lever 72. Of course, it is to be understood that the armrest 18 may be similarly adjusted.