Patent GB-808872-A (GB)
Title: A prower actuated tool
IPC: B25C1/12
Filed: 1957-02-22
Abstract: 808,872. Power-operated fastener driving and punching tools. OLIN MATHIESON CHEMICAL CORPORATION. Feb. 22, 1957 [June 8, 1956], No. 6009/57. Class 83 (4). [Also in Group XXI] Relates to a power-actuated tool, e.g. a cartridge or fluid-pressure actuated tool, in which a powerdriven ram moves in a guide member between initial and final positions to drive a fastener into or to punch a hole in a workpiece. According to the invention a tool housing member and the guide member are arranged for relative axial movement and ram return means are provided which, in response to relative movement of the housing and guide members, return the ram from the final position to the initial position. Fig. 4 shows a cartridge-actuated tool for firing fasteners 43 and Fig. 15 shows a portion of the same tool but modified for punching instead of fastener driving. The tool comprises a housing member 40, a driving ram 41 moving in a ram guide 42 which in turn slides in the housing member 40 and is urged outwardly thereof by a spring 72. The ram 41 is provided with an abutment 74 and the member 40 has an abutment 75, both abutments travelling in a slot 42b in the ram guide 42. In the withdrawn and breech-open position shown in Fig. 4, the two abutments 74, 75 are in engagement at one end of the slot 42b. On engaging the workpiece and closing the breech by pressing down the housing 40 against the action of the spring 72, the Fig. 5 position is obtained in which the abutment 75 has moved down to the lower end of the slot 42b. On pulling the trigger, the cartridge is fired to drive the ram 41 and its abutment 74 downwardly until the ram head engages a bush 46 screwed into the muzzle end of the guide 42, the ramrod 41r passing through a bore in the bush 46 to engage the fastener 43. On removal of the tool from the workpiece, the housing 40 is moved rearwardly with respect to the guide 42 under the action of the spring 72 and the housing abutment 75 engages the abutment 74 and moves it with the ram 41 back to the initial position shown in Fig. 4. For a punching tool, the ramrod 41ra, Fig. 15, may have a screw-threaded connection with the ram head 41h so that the depth of punching may be varied. Various means may be used to vary the gas chamber size and hence the firing power of the cartridges (see Group XXI, Class 119). Fig. 29 shows another tool in which the ram return is effected manually and not automatically. A sleeve 586 surrounds the housing 540 and a snap ring 587 is secured in a recess in the sleeve, the muzzle spring 572 being located between the ring 587 and another snap ring 576 secured in a recess on the ram guide 542. After firing and withdrawal of the tool, the spring 572 will move the tool parts to the Fig. 29 position except that the ram head 41h will be still in its fully driven position. If then the sleeve 586 is manually pushed forwardly over the housing member 540, the abutments 74 and 575 will engage to move the ram back to the initial position. Fig. 35 shows a part of a tool modified for punching in which the bush 646 is supplemented by a rubber bushing 648 which cushions the impact of the ram head.