GB891502A - Pneumatic nailing device - Google Patents

Abstract

891,502. Nailing machines. REICH, K. Sept. 9, 1959 [Dec. 24, 1958], No. 30762/59. Class 89(3) A pneumatic nailing machine comprises a cylinder 4, Fig. 1, a driver 10 slidable therein, a nozzle 38 containing a driving channel 39, a feed conduit 42 for nails or like fasteners ending in a portion 44 entering channel 39 through a lateral slot 45 and being movable thereoutof before the driver starts its stroke. A source of compressed air is connected to inlet 18 and enters a chamber 9 concentric with cylinder 4. A further concentric chamber 8 receives the air beneath the driver compressed during its stroke to return the driver to its raised position where it is held by plungers 12. When trigger 34, Fig. 2, is pivoted clockwise, valve 36 is closed and valve 31 opened to apply pressure air to raise piston 19 closing exhaust aperture 20 and opening valve 17. Thus air is applied above the driver from chamber 9 and the driver drives a nail 40 held in jaws 97. When the trigger is released the pressure in inlet 18 moves a piston 46 to restore the trigger. In this arrangement, the portion 44 is connected to the trigger to pivot therewith about pin 33. The nail-feeding mechanism consists of a hopper 50, Fig. 4, connected to conduit 42 via a valve 86, and nails are dropped individually into the hopper by a rod 54 which is reciprocated by a piston 53 to pick-up a nail in a recess 57 from guide rails 55 and release it into the hopper. Chamber 64 behind piston 53 is connected via conduit 63 to a valve 60 comprising a ball 67 controlling the supply of air from chamber 9 to a passage 62 and conduit 63. The ball is raised off its seat by a tappet 68<SP>1</SP> moved by the driver during its stroke. Passage 62 is vented to atmosphere, when the trigger is released, by a plunger 46<SP>1</SP> on piston 46. Thus, when the driver makes its stroke, valve 60 is opened and piston 53 moves to the left, and when the trigger is released, the piston is returned by a spring 69 to drop a nail in the hopper, and moves, on a pivoted pawl 71, a bell crank 74 to open valve 80 and admit compressed air from a conduit 82 to move valve 86 to the left, and admit a blast of air via line 91 to conduit 42 to move a nail therealong. As piston 53 is returned, the pawl slips off lever 74 and valves 80, 86 are restored to their original positions. In another arrangement, the nozzle 38 is slidable into the cylinder against a spring and has one or more oblique end faces engaged by rollers on portion 44 which pivots out of the drive-channel as the nozzle moves in. Portion 44 moves the equivalent of trigger 34 which may be within the machine. In a modification, the sliding nozzle 306, Fig. 8, moves a lever 308, 309, 310, pivoted at 307, against a spring 313, to remove a stop 314 and permit trigger 305 to pivot portion 44 out of the drive channel.