Patent GB-780311-A (GB)
Title: Improvements in or relating to apparatuses comprising fastener handling devices
IPC: A43D71/00
Filed: 1955-04-29
Abstract: 780,311. Nailing machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. April 29, 1955 [May 3, 1954], No. 12361/55. Class 89(3) In a fastener handling apparatus, fasteners are supplied singly to a delivery pipe along which each fastener is blown to a fastener inserting assembly by a blast of air the duration of which can be controlled by means of an adjustable valve mechanism in the air supply system. The fasteners, which may be nails, are stored in a hopper 20, Fig. 1 from which they are transferred to a raceway 24 by means of a lift slide 26 in the hopper 20, as the lift slide is driven up and down by a pneumatically actuated piston and cylinder device D. The nails are supplied singly to the delivery pipe 34 by means of a separating mechanism comprising a segment 28 Fig. 8 having a slot 30 into which a single nail from the raceway 24 can pass, the segment being given rotary reciprocation about a shaft 102 by the piston and cylinder device D, whereby the slot 30 moves to and fro between the end of the raceway 24 and a position where it is in communication at opposite ends with the delivery pipe 34 and air pipe 154. The separating mechanism includes a presser foot which moves to engage the nail next to the endmost one on the raceway to prevent entry of more than one nail into the slot 30, and a magnet is secured to the segment 28 opposite the slot 30 to ensure that the shank,of the separated nail completely enters the slot 30. The fastener inserting assembly 36, which is similar to that described in Specification 780,310 includes a driver 142 attached to a differential piston 140 which is pneumatically operated, when the nosepiece 40 is pressed against the workpiece, by compressed air supplied along a pipe 42. A duct 148 which is pressurized consequent upon the driving stroke of the piston 140 and which is ventend to the atmosphere consequent upon the return stroke of the piston 140, comrriunicates with signal pipe 44 which is connected to a valve 150. Pressurization of the duct 148 operates the valve 150 to cause pressure from the line 42 to be applied to a pipe 156 leading to the piston and cylinder device D causing the piston 158 to move to the left to raise the lift slide 26 in the hopper and to rotate the segment 28 until the slot 30 is aligned with the raceway 24; Simultaneously, compressed air is applied to the pipe 162 to open the valve 152 in the pipe 154. When the duct 148 is subsequently vented to the atmosphere upon the return stroke of the piston 140, the valve 150 returns to its previous position in which compressed air is applied to an air pipe 160 leading to the piston and cylinder device to move the piston 158 to the right and thereby lower the lift slide 26 and return the segment 28 to the position in which the slot 30, with a nail therein, is aligned with the pipe 34. Simultaneously compressed air is applied from the valve 150 to the pipe 154 so that a blast of air blows the nail along the pipe 34 to the fastener inserting assembly and also the compressed air supply from the valve 150 over the pipe 162 to the valve 152 is cut off so that the valve 152 commences to close. The time taken for the'valve 152 to close controls the length of the air blast in the pipe 34, this time being determined by means of an orifice restricted by an adjustable screw 196 through which the working space of the valve 152 is vented to the atmosphere. In a modified air supply system, Fig. 9, the piston and cylinder device D is operated in one direction by pressure direct from the signal pipe 44 upon pressurization of the duct 148 and in the other direction by a return spring 218 when the duct 148 is vented to the atmosphere, and the pipe 222 which supplies air to the pipe 34 is controlled by series valves 224, 226 of which 224 upon venting of the duct 148 moves from.a closed position to an open position and of which 226 simultaneously moves from an open position to a closed position, the time taken for these valves to so operate being variable by means of adjustable screws 230, 232 which form restrictions in venting orifices, to control the duration of the air blast in the pipe 34.