Patent GB-929341-A (GB)
Title: Fastener driving apparatus
Inventor: WANDEL OSCAR ALFRED
IPC: B25C1/04
Filed: 1959-07-07
Abstract: 929,341. Nailing-machines. FASTENER CORPORATION. July 7, 1959, No. 23365/59. Class 89 (3). A pneumatically-operated nailing-machine comprises a hollow body 22, Fig. 3, to which compressed air is supplied through a line 32, and containing a movable cylinder 36 with a piston portion 72 slidable in a cylinder 26, there being a piston 38 slidable in cylinder 36 with a channelsection blade 40 to drive a nail 34 from a magazine 58 through a drive-track 50. Cylinder 36 is held in the position shown by air through passages 88, 90 to chambers 70a, 86 and seats on valve 48. With valve 108 raised by sliding stirrup 116 when the machine is placed against a workpiece, the holding air is supplied via passages 126, 130, 124, 90. To operate from this latter condition, trigger 142 is moved to raise ball 146 against seat 128, thus exhausting chambers 70a, 86 to atmosphere via grooves in member 138. Trigger 142 may be operated before stirrup 116 is raised, if desired. Cylinder 36 moves down until ports 174 exhaust the space beneath piston 38 through apertures 178 and valve 48, held by shoulder 84a, separates from the cylinder, thus applying the air pressure in body chamber 28 to the upper face of piston 38 which is moved rapidly to drive a nail. After separation, valve 48 moves up due to differential air pressure thereacross, to close exhaust valve 158, Fig. 10, against plate 166. The piston is cushioned by a bumper 100. In moving down the bevelled end of blade 40 opens a valve 190b to connect chamber-pressure to port 209, closed by cylinder 36, via passages 192, 207. Release of trigger 142 or of stirrup 116 or both reapplies pressure to chambers 70a, 86, thus raising the cylinder 36 to close apertures 178, open port 209, abut and move valve 48 upwards to separate inturned shoulders 80b from valve 158 and press them against plate 166, thus momentarily opening the space above piston 38 to exhaust via passages 66a, Fig. 2, and cause the pressure differential across valve 48 to move the valve and cylinder back to the Fig. 3 position. Thus, the space above piston 38 is completely exhausted and piston 38 raised by air-pressure at port 209, finally to close valve 190b. The machine is then ready for a further cycle of operations to drive another nail. The magazine 58 has a slot 218, Fig. 4, to receive a strip of nails urged towards track 50 by springs 222, 224 secured to pegs 226 in the magazine at one end, and extending over pulleys 228, 230 to engage projections 220b, 220d on a member 220 in slot 218 behind the strip. The magazine has slotted sides slidingly engaging a plate 62 on the bottom of body 22 and is held with track 50 aligned with blade 40 by a spring-pressed lever 246 engaging a detent 240 pivoted at 244 and adjustable by screw 258. On release, the magazine is moved forwards and a screw-head (Fig. 5, not shown) depending from the body abuts projection 220c to hold member 220, thus enabling a fresh nail strip to be applied easily. The magazine is latched in the forward position by a detent 268 releasably by a button 280. Stirrup 116 is carried in grooves 118 in the magazine and moves away from the actuating arm 120 of valve 108, thus preventing inadvertent operation of the machine when the magazine is open. Specifications 929,342 and 929,343 are referred to.