MEJORAS INTRODUCIDAS EN LOS APARATOS DISPARADORES DE CLAVIJAS

摘要

981,938. Cartridge-operated tools. OMARK INDUSTRIES Inc. Oct. 11, 1963 [Feb. 1, 1963], No. 40210/63. Heading B4C. A cartridge-operated tool for driving studs 28 or like fasteners into hard materials comprises a piston P slidable in a barrel 13 and a ram R having a shank portion slidable in a guide 27 and a head portion 26 adapted to be connected to the piston. The barrel 13 is slidable in the housing 10 of the tool and is provided with a slot 30 in which a key 31 connected to the guide 27, is movable; the key is provided with a finger portion 311 having a limited axial movement in a slot 33 in the housing. The head portion 26 of the ram R is formed with a hook-shaped end 25 adapted to engage with a correspondinglyshaped slot 29 in the piston P so that, when both ram and piston are contained within the barrel, they are securely connected together. In operation, to load the tool with a cartridge C, the barrel is pulled forward to the position shown in Fig. 4 so that a cartridge can be inserted into its bore 14 via an opening 12 in the housing; due to the co-operation of the key with the slot 33, the guide presses the piston into its rearmost position. The barrel is then pushed back to the position shown in Fig. 5. In order to fire the tool, the outer end of the barrel is pressed against the work by means of a handle 11 thereby causing the inner end of the barrel to urge the breech 15, against the action of a spring 16, into the cocked position. By depressing a trigger 23, the firing pin 19 is released to fire the cartridge and so drive the piston forward. The cartridge case is ejected when the gases trapped between the piston and inner end of the barrel are compressed as the barrel is again pulled outwardly; additionally, a spigot 42 is provided on the piston to enter the cartridge bore 14. In order to remove the piston and ram for repair or replacement, a spring-loaded pin 34, which normally maintains the key 31 in contact with the slot 33, is withdrawn so as to allow the key to enter a slot 32 in the housing; the key is then able to drop out of engagement with the guide 27. To prevent damage to the ram and piston due to over-travel of the latter, the key is adapted to partially fall out of engagement with the guide after the key abuts a surface 301 on the barrel.