GB1020196A - Improvements relating to a method of operating and construction of pneumatically operated stapling, nailing, or like apparatus - Google Patents

Abstract

1,020,196. Stapling machines. J. KIHLBERG. Oct. 28, 1964 [Oct. 29, 1963], No. 44045/64. Heading B4C. A method of driving, by compressed air, the piston 25 of a tool for driving fasteners such as staples, nails or the like comprises a valve 10 adapted to control, via a passage 11, the supply and discharge of the air leading to a cylinder 23 such that during all the time the compressed air is supplied to the upper pressure surface of the piston for effecting its working stroke, part of the air is utilized for building up an air pressure in a chamber 14 in order that, upon movement of the valve to connect the passage with an outlet port 8, the piston is returned to its starting position. Compressed air is fed into the tool via an inlet 5 and chamber 6 so as to normally maintain the head 44 of the valve into contact with its seat 47 thereby preventing the air passing via the passage 11, into the cylinder. To actuate the tool a trigger 19 is raised so as to depress a plunger 51 which, via a spindle 56, lifts a ball valve 57 off its seat 53 thereby admitting air through a passage 59 and ports 60, so as to act on a piston connected to the head and thus lift the latter from its seat as shown. Air then passes through the passage 11 and into the cylinder 23 to drive the piston 25 downwardly, air simultaneously entering the chamber 14 via a restricted port 15; the port may be replaced by an adjustable nozzle. When the piston 25 reaches the end of its working stroke and the trigger released, the compressed air in the chamber 14 passes through a port 20, and annular space 31 to act on the bottom face 31 of the piston so as to rapidly return it; air above the piston is exhausted via the passage 11, past an O-ring seal 46 on the valve 44, annular space 8 and passage 9. A magnet 21 is provided in order to retain the piston 25 in its inoperative position.