Patent GB-947905-A (GB)
Title: Improvements in or relating to fluid-operated driving means
IPC: B25C5/02
Filed: 1961-09-01
Abstract: 947,905. Stapling machines. BOSTITCH Inc. Sept. 1, 1961 [Dec. 5, 1960], No. 31599/61. Heading B4C. [Also in Division F1] A fluid-pressure operated driving means for a stapling machine comprises a piston 25 reciprocatable in a cylinder 26, a cycling valve 55 for supplying pressure fluid to the cylinder to drive the piston in an operative stroke, the valve being operable to apply pressure fluid to the opposite side of the piston to reverse its stroke, a starting valve 125 for feeding pressure fluid from a supply 96 to the cycling valve, and means 205 for progressively building up pressure to actuate the cycling valve to reverse the flow of pressure fluid to the piston. The stapling machine may be of the type described in which a plunger 33 connected to the piston 25 moves a crosshead 20, joined to pivoted arms 15 arranged to pierce holes in a carton before a blade 10 secured to the plunger discharges a staple S from a magazine 7 and clinches it against the arms. The piston 25 is reciprocated by air from an inlet pipe 96 when a carton is in an operative position and is controlled by the starting valve 125, throttle valve 205, reversing valve 180 and cycling valve 55. The starting valve consists of plungers 140, 145 co-operating with ports 135, 136 and joined together by a pin 151 so that when one port is open, the other is closed. The plunger 140 is mounted in a diaphragm 141. Normally the port 136 is closed and a pipe B is connected to atmosphere through a port 143 so that pressure in a pipe E connected by an open port 192 in the valve 180, which is similar in construction to the valve 125, and a passage 182 is at atmosphere and a spring 75 retains the spool 66 of the cycling valve 55 in its left-hand position, as shown, the supply pipe 96 being connected to the left-hand end of the cylinder 26 to hold the piston 25 and stapling means in their retracted position. When a carton is positioned adjacent the stapling means, a detector lever 110 is rocked to cause a stud 11<SP>6</SP> to engage the plunger 140 of the starting valve so that port 135 is closed and port 136 opened and pressure from the supply pipe 96 is connected by pipe A and the now open port 136 to the pipe B. The pressure in pipe B is communicated directly by the pipe E, the open port 192 of valve 180 and the passage 182 to the end of the spool 66 of valve 55 which is moved against the spring 75 to its alternative position and connects the left-hand end of cylinder 26 to an exhaust passage 95 and the right-hand end to the supply 96 to move the piston 25 to the left. The movement of the piston moves the plunger 33 which is connected to the crosshead 20 by a roller 36 so that, during the initial movement of the plunger, the crosshead is moved to cause the arms 15 to pierce the carton. At a predetermined position of the plunger, the roller drops into a recess 39 to hold the crosshead and arms stationary while further movement of the plunger causes the driver plate 10 to remove a staple from the magazine and clinch it against the arms. The throttle valve 205, which is adjustable by a screw 219 enables the fluid in pipe B to pass slowly to a chamber 186 in valve 180, the pressure gradually rising in the chamber until such time as it can move the plungers 191, 193 of the valve to close port 192 and open port 198 whereby the passage 182 is connected by holes in a diaphragm 196 to a port 200 open to atmosphere. The drop in pressure in passage 182 enables the spring 75 to return the spool 66 of the cycling valve to its original position and the supply from pipe 96 to retract the piston 25 and stapling means until the next carton is detected by the lever 110. Canadian Specification. 746,943 is referred to.