Patent GB-190814685-A (GB)
Title: Improved Driving and Reversing Mechanism.
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1908-07-10
Granted: 1909-07-12
Abstract: 14,685. Thompson, W. P., [Conkling Co.]. July 10. Planing.-In a driving and reversing mechanism, applicable to planing-machines &c., oppositely rotating driving-members upon the driven shaft are adapted to be alternately clutched thereto by sliding clutch members operated by means of externally and internally screw-threaded members always in engagement, one of which is checked and reversed by mechanism utilizing power supplied by the oppositely rotating clutch members. A reciprocating work-table 4, Fig. 1, with a rack 5 is driven by a pinion 7 on a shaft 6 geared by pinions 10, 9 to the reversing- shaft 8, which extends beyond the frame 2 into a casing 11 containing the driving and reversing clutch mechanism. The casing comprises a lower part bolted to the frame 2 and an upper part or cover held in place by bolts 11<11>. The motor shaft 17 drives a shaft 18, Fig. 2, and sleeve 19 mounted thereon in opposite directions through bevel pinions 171, 181, 19<1>. Loose sleeves 26<1>, 21' upon the shaft 8 are continually rotated in oppos i t e directions by the shaft 18 and sleeve 19 respectively, the reverse sleeve 20<1> being connected by high-speed gearing 18<11>, 20", while the forward driving-sleeve 21' is connected to the sleeve 19 by several pairs of wheels, any one of which may be put into action by a sliding key 23 operated by a lever &c. 25, connecting one of the loose pinions 19<11>, 19<111>, &c. to the sleeve 19. The main clutch members 20, 21, normally rotating in opposite directions, are alternately clutched to the shaft 8 by sliding cones 27', 28<1>, Fig. 6, moved into engagement by screw and nut members 30, 31. The nut member 31 is rotatably mounted upon disks 27, 28 keyed to the shaft. The cones 27<1>, 28<1> are connected by rods 29 passing through the disks 27, 28, and the screw member 30, springs 27<111>, 28<111> being interposed. Thus, when the rotation of the nut 31 is checked or reversed, the screw member 30 slides axially upon the shaft 8, and acting at first through the springs, then positively against lugs 27<11> or 28<11>, slides the cones 27', 28<1> upon the hubs of the disks 27, 28 into engagement with one of the driving- members 20, 21. The driving-members 20, 21 carry means for checking and reversing the nut 31 in the form of adjustable friction blocks g mounted upon pivoted arms 20<b>, 21<b>. The clutch parts carried by the driving-members may be ordinary internal cone members, but are preferably formed by segmental shoes 20<a>, 21<a> carried by the pivoted arms 20<b> 21<b>. These arms are normally expanded by centrifugal force but are alternately moved inwards by sliding collars 32, 33 respectively, acting through rollers f. When, as shown in Fig. 6, the member 21 is driving, reversal may be effected by simultaneously shifting the collars 32, 33 to the right. The clutch parts 21<a> are thereby released, and with the gripping-blocks upon the arms 21<b> rise out of engagement, while the oppositely rotating clutch shoes 20<a> are by the collar 32 moved into position for engagement, and the blocks g upon the arms 20<b> grip or engage the nut member 31. This action checks and then reverses the rotation of the nut 31, thereby causing the screw-member 30 to move axially, carrying the cone members towards the alternate driving-member 20 until a solid drive therefrom is effected. The collars 32, 33 are engaged and operated by yokes 34, 35 sliding on a guide-rod 36 and connected by a plate 37. The plate 37 is operated to slide the yokes and clutch rings by means of a plate 43 sliding iii guides on top of the casing, a pin 37<1> on the plate 37 engaging. a cam slot 44 in the plate. The plate is connected' by a pivoted lever 42 and link 41 to a rocking lever 40, which may be operated automatically by tappets 38, 39 on the reciprocating table or manually by a handle 40<a>. In the mid position both clutches on the shaft 8 are disengaged. The arrangement of the clutch members may be modified by mounting, parts on independent concentric bearings instead of directly upon the shaft. In some cases the friction blocks g may be replaced by positive engaging members. For high-speed drives, the female clutch segments and the gripping-blocks g may be carried by separate levers operated by the same sliding ring and adjusted to ensure the clutch segments being moved into position before the blocks grip the screw-nut 31. The hand-lever 40 for disconnecting both clutches, may be supplemented or replaced by an independent clutch between the shaft 17 and the motor, normally kept in engagement by a spring and adapted to be thrown out of action by a pivoted lever operating a plunger rod passing through the pivot of the hand-lever 40 and connected by a bell-crank and links to the clutch. In a modification, the externally threaded screw member is attached to a slidable sleeve upon which spring-pressed female clutch members are loosely mounted, while the friction blocks are carried by arms pivotalty mounted on the internally threaded screw member and are adapted to engage the said female clutch members. The internally threaded screw member is rotatably mounted upon the male clutch members, which are keyed to the shaft and provided with apertures to accommodate the above-mentioned sliding sleeve. In a further modification the externally screw threaded member is the only member fixed to the shaft, the internally threaded member being formed with conical ends adapted to be engaged by spring-pressed female clutch parts carried by loosely mounted gear-driven members, and carrying pivoted arms serving to frictionally engage and retard or reverse the internally threaded member when required. In this case, the drive is effected through the frictional grip of the external and internal screw threaded members, when the latter is moved longitudinally in co-operation with the female clutch members.