| 摘要 |
833,260. Screwing-up screws. BRITISH UNITED SHOE MACHINERY CO. Ltd. Nov. 30, 1956 [Dec. 1, 1955], No. 36627/56. Class 83 (3). [Also in Group VII] In a fastener supplying-device for supplying fasteners to a nail or screw-inserting machine, an orderly array of fasteners is assembled on.a downwardly-extending track 28, near the lower end of which holding means 236, engageable with the fasteners on the track, is provided to alternately restrain and release the array so that one fastener at a time is allowed to pass into a position on an area 266, from which that fastener may pass through a slot 292 in a shutter 268 into a chamber, from which it can be blown along a delivery pipe 235 to the nail or screwinserting machine, the shutter being movable about an axis from the position shown in Fig. 4, in which the fastener can pass through the slot 292, to the position shown in Fig. 2, in which the shutter 268 intercepts communication between the track 28 and the chamber. The shutter 268 is controlled by a piston 298, Fig. 3, having large and small piston-heads 302, 312, respectively at opposite ends, contained in a horizontal bore of a housing 270, the piston carrying a rack 294 coupled to a pinion 290 at the upper end of the shutter 268. The housing is connected to a pipe 338, which is pressurized and then vented consequentially upon operation of the fastener-inserting machine. The pressure in the pipe 338 acts upon the head 302 and moves the piston 298 downwardly, as viewed in Fig. 3, thereby rotating the pinion 290 and moving the shutter 268 from the position shown in Fig. 4 to the position shown in Fig. 2. At the end of the downward stroke of the piston 298, the piston-head 312 moves clear of a sleeve 318 and allows compressed-air from a pipe 334 to pass into a fitting 324, along a pipe 332 and through the slot 292 in the shutter 268 to blow the fastener in the chamber along the pipe 235 to the fastenerinserting machine. A pipe 330, also connected to the fitting 324, delivers compressed-air to a cylinder 240, causing a piston therein to be raised against a spring 256, thereby lifting a rubber-presser foot 236 clear of the fasteners on the track 28, allowing one fastener to fall on to the area 266 and against the shutter 268. Subsequently, when the pipe 338 is vented, the piston 298 moves upwardly to stop the flow of air to the fastener-receiving chamber and cylinder 240. The pressure-foot 236 thereupon re-engages the fasteners on the track 28, and the shutter 268 returns to the position shown in Fig. 4 so that the fastener released on to the area 266 passes through the slot 292 into the chamber, ready for delivery to the fastenermachine. To ensure that the shutter is fullyoperated before the pressure-foot 236 is lifted, and to ensure that sufficient time elapses for the fastener to be blown along the pipe 235 to the inserting-machine, the rack 294 is mounted for limited sliding movement on the piston 298, and is biased downwardly by a spring 306 so that during downward movement of the piston 298, the movement of the rack 294 only is arrested by abutment with the end portion 319 of the sleeve 318, so that the phases-ofmovement of the piston-head 312 outside the sleeve 318 takes place whilst the shutter is stationary in the position shown in Fig. 2. When using the fastener-supply device with a nail-gun, the pipe 338 is pressurized at the instant of operation of the gun, but when used with a screw-inserting machine, operation of the device is delayed until the driving of the screw already in position in the machine is completed. Specifications 801,209 and 832,984 are referred to. |
