GB1218996A - Power-actuated fastener-driving tools - Google Patents

Abstract

1,218,996. Fastener driving tools. OLIN CORP. 15 Nov., 1968 [1 May, 1968], No. 54346/68. Heading B4C. A fastener driving tool comprising a housing 4, a slidably mounted barrel 52 and a driving piston 78 includes a piston return device which is such that the position of the piston relative to a cartridge chamber 56 may be varied. Variation of this position effects variation in the force initially applied to the piston. The device illustrated comprises a pawl member 96 spring urged into the barrel bore via slot 62 in the barrel. Shoulders 112 engage the outer surface of the barrel and surfaces 130 on the barrel engage tapered surfaces 114 or 116 or the pawl member when the barrel is moved to its firing position to move the pawl member out of the path of the piston. When the pawl member is fully withdrawn (Fig. 8, not shown) the barrel can be removed from the housing to permit reversal of the pawl member from the position of Fig. 1 to that of Fig. 6. When, after a fastener driving operation, the barrel is moved away from its firing position relative to the housing, the pawl member will first engage the piston and then engage the barrel. The relative positions of the barrel and piston will be as illustrated in Figs. 5 or 6 depending on the preset condition of the pawl member. Alternative forms of pawl member are described including a form in which the member may include an arcuate surface providing an infinitely variable adjustment.