Press having slide shut height adjusting and locking mechanism
The present invention relates to the art of presses and, more particularly, to a press having an improved slide shut height adjusting and locking mechanism. 
     In the art of mechanical presses, it is of course known to pivotally interconnect the connecting rod of a press drive mechanism with the press slide by a ball and socket type interconnection and to provide for the component parts interconnecting the connecting rod and slide to be adjustable to enable adjustment of the shut height of the slide relative to the press bed. The adjusting mechanism generally includes relatively rotatable threadedly interengaged members one of which is associated with the connecting rod and the other of which is associated with the slide. Rotation of one of the elements relative to the other imparts displacement to the slide relative to the connecting rod and thus to the press bed. Locking arrangements are provided in conjunction with the adjusting mechanism to lock the rotatable elements against relative displacement. The intended purpose of such locking arrangements is to maintain the desired shut height for the slide during operation of the press and the resultant impact loads and forces imposed on the adjusting mechanism by engagement of tooling carried by the slide with a workpiece supported on tooling mounted on the press bed. Further in connection with such adjusting mechanisms and locking arrangements therefor, it is desirable to obtain maximum slide adjustment capability relative to the press bed, ease of adjustment of the shut height, and a locking arrangement which optimizes maintaining a given shut height during operation of the press. 
     The present invention provides a shut height adjusting mechanism and locking arrangement by which the foregoing advantages are achieved in connection with a ball and socket type interconnection between the slide and connecting rod of the press drive mechanism. More particularly in accordance with the present invention, one member of the ball and socket interconnection is an adjusting screw member threadedly engaged with the slide and axially fixed with respect to the connecting rod. The adjusting screw member is rotatable relative to the slide through the threaded engagement therewith and is rotatable relative to the connecting rod through the ball and socket interconnection. Accordingly, it will be appreciated that rotation of the adjusting screw member imparts displacement to the slide relative to the connecting rod and thus the press bed. 
     Additionally, the slide carries a locking nut member surrounding the threads on the adjustment screw and which locking nut member is rotatable relative to the adjusting screw and the slide. The locking nut member and the slide have axially opposed abutment surfaces, and the locking nut is rotated relative to the slide to bring the abutment surfaces into engagement to impose an axial force on the adjusting screw which locks the latter against rotation relative to the slide and connecting rod. Such application of axial force on the adjusting screw preferably preloads the screw in the direction of the driving force of the slide, thus removing all backlash in the adjustment screw. Preferably, rotation of the locking nut in the direction to release the adjusting screw for rotation is limited, and the locking nut is supported by the slide in a manner whereby the adjusting screw is rotatable relative to the nut and to the slide to achieve adjustment of the shut height. Limited rotation of the locking nut in the direction to release the adjusting screw assures a running thread clearance therebetween so that the adjusting screw can be freely rotated relative to the nut. 
     In addition to more effectively maintaining the slide in an adjusted position against displacement during operation of the press, in comparision to previous adjusting and locking arrangements, the adjusting and locking arrangement of the present invention enables maintaining optimum slide adjustment capabilities, in other words a desirable length of available slide adjustment relative to the connecting rod of the press drive mechanism. Still further, the mechanism is economical to manufacture and install, is compact, and is simple to operate and thus enables adjustment and locking to be quickly achieved. 
     It is accordingly an outstanding object of the present invention to provide an improved slide shut height adjusting and locking mechanism for a press having a ball and socket type interconnection between the slide and connecting rod of the press drive mechanism. 
     Another object is the provision of a slide adjusting and locking mechanism of the foregoing character which includes an adjusting screw member for achieving shut height adjustment and a locking nut member interengaging the adjusting screw member and slide to lock the adjusting screw member against displacement relative to the slide. 
     Still another object is the provision of a slide adjusting and locking mechanism of the foregoing character in which the locking nut member interengages the adjusting screw and slide to preload the adjusting screw in the direction of the driving force on the slide. 
     A further object is the provision of a slide adjusting and locking mechanism of the foregoing character which is inexpensive to manufacture and install, which is more efficient in maintaining slide adjustment than arrangements heretofore provided, which facilitates achieving slide adjustment with relative ease, and which enables maintaining optimum adjustment capability of the slide relative to the connecting rod of the press drive mechanism. 
    
    
     The foregoing objects, and others, will in part be obvious and in part pointed out more fully hereinafter in conjunction with the written description of a preferred embodiment shown in the accompanying drawings in which: 
     FIG. 1 is a front elevation view of a press incorporating the slide adjusting and locking arrangement in accordance with the present invention; 
     FIG. 2 is a sectional elevation view of the slide taken along line 2--2 in FIG. 1 and showing the slide adjusting and locking mechanism in detail; 
     FIG. 3 is a cross-sectional view of the mechanism taken along line 3--3 in FIG. 2; 
     FIG. 4 is a cross-sectional view of the mechanism taken along line 4--4 in FIG. 2; and, 
     FIG. 5 is a sectional elevation view of the mechanism taken along line 5--5 in FIG. 4. 
    
    
     Referring now in greater detail to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the invention, FIG. 1 illustrates a press 10 having a frame 12 which supports a slide 14 for reciprocating movement toward and away from press bed 16. The press further includes a flywheel 18 attached to one end of a crankshaft 20 which is interconnected with slide 14 by a connecting rod 22, whereby rotation of crankshaft 20 imparts reciprocating movement to slide 14. In the embodiment shown, flywheel 18 is driven through a brake-clutch unit 24 by means of a drive motor 26 and a drive belt 28 interconnecting the motor and brake-clutch unit. 
     In accordance with the present invention, slide 14 is adjustably interconnected with connecting rod 22 to enable adjusting the shut height of slide 14 or, in other words, the distance between slide 14 and press bed 16 when the slide is in its lowermost or bottom dead center position. In this respect, as best seen in FIGS. 2-4 of the drawing, slide 14 has an axis 30 and includes an annular adjustment barrel member 32 which is coaxial with slide axis 30. In the embodiment shown, barrel member 32 is in the form of a sleeve attached to the slide such as by bolts 34. Accordingly, it will be appreciated that barrel member 32 is fixed to the slide and in effect is a portion of the slide. Slide 14 includes a recess 36 coaxial with slide axis 30, and barrel member 32 and recess 36 receive a slide adjusting screw member 38 which is coaxial with the slide axis. Adjusting screw member 38 has an upper end 40 disposed within the upper portion of barrel member 32 and provided with axially extending external gear teeth 42 for the purpose set forth hereinafter. Barrel member 32 has a lower portion 44 provided internally with butress threads 46 to define a threaded passageway receiving lower portion 48 of adjusting screw member 38 which is provided with external butress threads 50. Threads 50 on adjusting screw 38 matingly engage threads 46 of barrel member 32 for the purpose set forth hereinafter. 
     In the embodiment shown, the lower end of connecting rod 22 is provided with a ball 52, and the upper end of adjusting screw member 38 is axially recessed to receive socket forming components for ball 52. In this respect, the recessed upper end of adjusting screw member 38 receives and supports a lower ball block 54 and an upper ball cap 56, which block and cap members are retained in assembled relationship with ball 52 by means of a retaining ring 38 attached to the upper end of adjusting screw member 38 by means of a plurality of bolts 60. It will be appreciated of course that the ball block and ball cap members are contoured for mating engagement with ball 52 to swivelly interconnect connecting rod 22 and slide 14. Thus, adjusting screw member 38 is adapted to rotate relative to slide 14 through the threaded interconnection between screw member 38 and barrel member 32 and is adapted to rotate relative to connecting rod 22 through the ball and socket connection. While ball 52 is shown as being on the end of connecting rod 22, it will be appreciated that the ball could be fixed to adjusting screw member 38 or could be an integral part thereof. In such case the connecting rod would carry the socket portion of the connection, thus enabling rotation of the adjusting screw relative to the slide and connecting rod as in the preferred arrangement shown. 
     It will be appreciated of course that slide 14 and connecting rod 22 are restrained against rotation about slide axis 30 by their respective interengagements with the press frame and crankshaft. It will be further appreciated that adjusting screw member 38 is axially fixed with respect to connecting rod 22 by the ball and socket interconnection therebetween. Accordingly, rotation of adjusting screw member 38 relative to the slide and connecting rod about slide axis 30 rotates threads 50 of the adjusting screw member relative to threads 46 on barrel member 32, thus causing axial displacement of slide 14 relative to connecting rod 22. Rotation of adjusting screw member 38 can be achieved in any desired manner. In the embodiment shown, rotation is achieved by means including a slide adjusting gear 62 which is mounted on the upper end of adjustment barrel member 32 such as by means of a pin 64 for rotation about an axis parallel to slide axis 30. Gear 62 includes an upper worm wheel portion 66 and a lower pinion portion 68 having axially extending teeth 70 in meshing engagement with external teeth 42 on adjusting screw member 38. Gear 62 is adapted to be rotated about its axis and relative to barrel member 32 by a worm gear 72 supported by the slide for rotation about an axis perpendicular to pin 64. Worm gear 72 can be rotated in any suitable manner. For example, the worm gear could be rotated by a motor carried on the slide, or manually such as by a crank. 
     Slide adjusting gear 62 is axially fixed on barrel member 32 and thus is axially displaced with the slide, and external gear teeth 42 on the upper end of adjusting screw member 38 slide axially relative to teeth 70 on pinion gear portion 68 of gear 62 during relative axial displacement between slide 14 and connecting rod 22. The lineal extent of axial adjustment available between the slide and connecting rod is of course determined by the axial length of gear teeth 42 and the axial length of threads 50 on adjusting screw member 38. 
     When the slide has been adjusted relative to the connecting rod by rotation of adjusting screw member 38 to achieve a desired shut height for the slide relative to the press bed, it is desirable to lock the adjusting components against relative displacement during subsequent operation of the slide in order to maintain the desired shut height for the slide. In accordance with the present invention such locking is achieved by means of a locking nut 74 coaxial with and surrounding adjusting screw member 38 and located in a circumferential recess provided therefor in the slide. Locking nut 74 has internal butress threads 76 matingly interengaging exterior threads 50 on adjusting screw member 38. Further, the locking nut is provided with external axially extending gear teeth 78 in meshing engagement with the external teeth of a locking pinion 80 mounted on the slide for rotation about an axis parallel to slide axis 30. More particularly, pinion 80 is mounted on the upper end of a pinion shaft 82 which is rotatably supported by the slide and which has a lower end 84 provided with wrench flats for turning the shaft. Shaft 82 is externally threaded adjacent end 84 to receive a jam nut 86 which engages against a shoulder 88 on the press slide to lock shaft 84 against rotation. 
     The circumferential recess in the slide which receives locking nut 74 has axially opposed upper and lower walls defined by surfaces 90 and 92, respectively. Upper surface 90 of the recess is provided by the barrel member portion of the slide, and surfaces 90 and 92 are spaced apart a distance slightly greater than the thickness of the locking nut as defined by the planar upper and lower sides 94 and 96 thereof. Nut surface 94 and surface 90 of barrel member 32 define axially opposed abutment surfaces on the nut and slide, respectively, and as will be described more fully hereinafter these surfaces are cooperable to lock the adjusting mechanism in a given position of slide adjustment. The locking nut is rotatable in one direction relative to adjusting screw 38 to tightly interengage surfaces 90 and 94 and is rotatable in the opposite direction to axially displace upper side 94 of the locking nut from surface 90. When the nut is rotated in the latter direction adjusting screw 38 is freed for rotation relative to barrel member 32 and locking nut 74. 
     To assure proper thread clearance for relative rotation between adjusting screw 38 and locking nut 74, the slide and locking nut are preferably provided with an interengaging arrangement to limit rotation of the locking nut in the direction of release. In the embodiment disclosed, as best seen in FIGS. 4 and 5, such an interengaging arrangement is achieved by providing locking nut 74 with a pin 98 projecting from upper side 94 thereof and into an arcuate circumferentially extending recess 100 in barrel member 32. Pin 98 and recess 100 are positionally associated with one another such that rotation of locking nut 74 in the direction to displace upper side 94 thereof from surface 90 is stopped by engagement of the pin with one end of recess 100 when the locking nut is in a rotational position which enables adjusting screw 38 to freely rotate relative thereto. It will be appreciated, of course, that the pin could be on barrel member 32 and the slot provided in locking nut 74. 
     In order to change the shut height of the slide from a given position in which the locking nut is in the locked position thereof, jam nut 86 is rotated to release shaft 82 for rotation, and a suitable wrench is employed to rotate shaft 82 and thus pinion 80 in the direction to rotate locking nut 74 to displace upper side 94 thereof from surface 90 of barrel member 32. When locking nut 74 has been rotated to a position which provides the necessary thread clearance between threads 76 thereof and threads 50 of adjusting screw member 38, pin 98 and recess 100 interengage to stop further rotation of the locking nut. Adjusting screw 38 is then rotated by means of gear 62 in the manner described hereinabove to adjust the slide upwardly or downwardly relative to connecting rod 22. During such rotation of adjusting screw member 38, locking nut 74 is held against rotation by pinion 80, whereby adjusting screw 38 freely rotates relative to the locking nut. When the slide has been displaced to the new position, pinion 80 is rotated by means of shaft 82 to rotate locking nut 74 in the direction to displace upper side 94 thereof tightly against surface 90 of barrel member 32. Pinion 80 enables the application of a high torque to the locking nut, and by tight engagement between locking nut surface 94 and surface 90 of barrel member 32 the adjusting screw 38 is pre-loaded in the direction of the driving force of the slide. All backlash and thread clearances between adjusting screw 38 and threads 46 on barrel member 32 are removed and locked out by such interengagement between surfaces 90 and 94, and are maintained locked out by tightening jam nut 86 against slide surface 88 to lock pinion 80 against rotation. 
     While particular emphasis has been placed on the preferred embodiment of the invention herein illustrated and described, it will be appreciated that many changes can be made in the preferred embodiment without departing from the principles of the present invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.