| 摘要 |
1,224,780. Screwing - up tools. CHARLES CHURCHILL Ltd. 25 June, 1969 [26 June, 1968], No. 30356/68. Heading B3N. [Also in Division B8] An apparatus for automatic application to work of screws, nuts &c., comprises a pivoted holder 13 normally positioned between camcontrolled jaws 17 to receive an object e.g. released from an escapement mechanism 12 described in Specification 1,224,779, a cam 21, normally maintaining the jaws 17 open, operable to cause the jaws to close on an object when held in the holder 13, the holder thereafter being movable from its position between the jaws, to release the object and the jaws being movable to carry the object towards the work, apply it to the work and thereafter, under the action of the cam, to release the object, and an applicator tool 30 for completing application of the object to the work. After receiving a screw, an automatic screwdriver proceeds to screw the screw into a workpiece. A shaft 22, rotated by a pneumatic turbine 28, is lowered by a pneumatic piston-and-cylinder arrangement 24, 25 whereby the cam 21, supported at the lower end of the shaft by a circlip 42, is caused to enter jaw recesses 44 whereby the jaws 17 close under the action of springs 20 to grip the screw. During downward movement of the shaft 22 a roller 45 engages a cam-face 46 on the holderarm 14 to pivot the holder 13 from between the jaws, thereby releasing the screw. Thereafter, a member 26 carried by the upper end of the shaft 22 abuts the upper end of a sleeve 32, and, through a spring 31 imparts downward movement to a sleeve 19 surrounding shaft 22. The jaws 17, carried by sleeve 19, the shaft 22, and bit 30 move downwards together until a collar 33 on the sleeve 19 abuts a stop 47 to arrest movement of the sleeve 19 and jaws, continued downward movement of the shaft compressing spring 31. Cam 21 is then forced downwardly out of recesses 44 to open the jaws to release the screw into a tapped hole in the work. The final descent of the rotating bit 30 screws the screw home. Reversal of the motion of the piston-andcylinder arrangement 24, 25 at the upper and lower limits of jaw movement is via tripswitches 36, 37. The holder 13 may, alternatively, receive nuts to be screwed on to a male screw-thread, the bit 30 then being replaced by a blind female socket. |
