Patent GB-1386703-A (GB)
Title: Fastener applying device
IPC: B25C1/04
Filed: 1972-08-31
Abstract: 1386703 Pneumatically actuated fastener driving tool SENCO PRODUCTS Inc 31 Aug 1972 [22 Dec 1971] 40423/72 Heading B4C A pneumatically actuated fastener, e.g. nail, driving tool comprises a piston 140, having a fastener driver 142, reciprocable in an axially movable cylinder 54 between a driving position and a driven position. The cylinder is movable relative to the tool housing between a first position (Fig. 2) in which main valve 20 and vent passages 48 are closed and the cylinder space above the piston is open to exhaust via port 40 and a second position (Fig. 3) in which the main valve 20 is opened to communicate reservoir 19 with the cylinder space above the piston (that space being closed to exhaust port 40) and the vent passages 48 are opened to exhaust air below the piston during the working stroke. In operation, with the tool conditioned for "single fire" (i.e. with communication between passages 152, 156 blocked by mode selector valve 150), manual actuation of actuator 130 will enable pressure air to flow via ports 96, 112, 110, and 122 into the annular space between inner sleeve 120 and outer sleeve 88, so as to act on the whole under surface of stem 100 which is thus moved upwardly (see Fig. 3) to close communication between the reservoir 19 and space 30 above the cylinder and open that space to exhaust via slots (not shown) between cap 32 and housing 10. The pressure air now acting on the cylinder 54 causes the latter to move to its second position, so that the piston will be driven on its working stroke. The piston is halted in its driven position by resilient masses 144, 146. In this position pressure air above the piston can pass into a return chamber 154 via ports 66. Release of the actuator 130 results in its return to the position of Fig. 2 in which communication between ports 110, and 122 is closed by sealing ring 134 and the annular space between the inner sleeve 120 and the outer sleeve 88 is vented via ports 122 and sealing ring 132. Thus the upward bias on the stem 100 is removed so that that stem returns to its Fig. 2 position to permit supply of pressure air from the reservoir 19 to the space 30. The cylinder will now be forced to its first position (Fig. 2) in which pressure air in the return chamber can pass via ports 70 into the cylinder below the piston which is thus moved on its return stroke. When the tool is conditioned for "auto-fire" (i.e. with passages 152, 156 in communication) pressure air supplied to the return chamber 154 at the end of the piston's working stroke will pass via passages 152, 156 to move outer sleeve 88 upwardly relative to stem 100 (the actuator 130 being retained in its actuated position) so as to open space 30 to the reservoir 19 and close that space to vent. The cylinder 54 will thus be moved to its first position (Fig. 2) so as to effect piston return. Upon the space below the piston expanding, the forces acting on the enlarged portion 88a of the outer sleeve 88 will cause the latter to move downwardly so to close space 30 to the reservoir and open that space to vent. The cylinder will now move to its second position (Fig. 3) to initiate another working stroke of the piston. This cycle will be repeated until the actuator 130 is released.