GB979710A - Fastener driving apparatus - Google Patents

Abstract

979,710. Fastener inserting tools FASTENER CORPORATION. May 17, 1961, No. 18006/61. Heading B4C. A fastener driver comprises a cylinder 20 slidable in an enlarged part 16 of a chamber, a piston 22 slidable in the part 16 and in a part 14 of the chamber and carrying an element 24 for driving the fastener, a valve seat 28 normally engaged by the upper end of the cylinder, and control means 32, 34 for selectively admitting compressed-air into the upper end of the cylinder to actuate the piston for driving a fastener and into the lower end of the cylinder for returning the piston. In the raised position of the nail, staple &c. driving element 24, Fig. 1, the piston 22 and cylinder 20 are at the top of their stroke, the cylinder engaging the valve-seat 28 and preventing compressedair, from a passage 18 leading to a reservoir in the driver-handle, from entering the top of the cylinder, which is vented to atmosphere past a valve 66. This valve is held open, against the pressure of a spring 70, by pressure of the cylinder on a member 75 carried by the valve. A housing 58 for the valve 66 is clamped to a removable cap 26 by a bolt 60. Compressedair from the passage 18 is fed beneath the cylinder 20 and the head 22a of the piston, through passages 94, 96. The spaces between an enlargement 20a at the base of the cylinder 20 and a guide sleeve 44 and below the piston are vented to atmosphere at 54, 40. A resilient pad 36 is located at the bottom of the chamber 14, and a manually-operated valve 34 and a safety valve 32, operated against a resilient bias (not shown) by the engagement of a rod 92 on the work, are provided. Operation.-The valve 32 is operated, Fig. 2, closing the passage 94 and opening a passage 100, by positioning the tool, a reduced section 98 of the rod 92 being aligned with passages 96, 100. Trigger &c. operation of the ball-valve 34 to close passage 102, connects the lower ends of the cylinder 20 and piston-head 22a to atmosphere, through a passage 108 in valve 34 This causes the cylinder to move down, releasing the valve operator 75 and permitting the valve to close and a larger volume of compressed-air to enter the cylinder above the piston for effecting the power-stroke. On returning the valves 32, 34 to the setting of Fig. 1, the cylinder rises, opening the valve 66 to exhaust the top of the cylinder to atmosphere and allow the piston to return. Apertures or notches (not shown) may be provided in the lower end of the cylinder. U.S.A. Specification 2,944,522 is referred to.