Patent GB-429889-A (GB)
Title: Improvements in or relating to heel-attaching machines
IPC: A43D79/00
Filed: 1934-12-17
Abstract: 429,889. Boot - making machines. SANDT, J., Pirmasens, Germany. Dec. 17, 1934, No. 36083. Convention date, Dec. 18, 1933. [Class 17 (i)] Heels, machines for. - Relates to inside attaching machines provided with an automatic nail feed block moving between a supplying means and the shoe support, and consists in the provision of a hand guard or rest and automatic means for lowering the shoe support below the guard prior to the advance of the feed block and raising it again for work positioning after the nails have been supplied. Preferably, a system of liquid pressure pistons is employed to move the machine parts in sequence. The hand guard engages the shoe support closely, to remove the work from the support as the latter is lowered. A shoe support 2 is carried by a piston 7 normally held in its uppermost position by a spring 41. A hand rest or guard 53 has a U-shaped recess in close proximity to the support. A tread abutment 3 normally held upwardly by a spring 8, is raised and lowered by a piston 3<1>. A nail feed block 6 reciprocated by a piston 6<1>, moves between a nail supplying means and the shoe support, the usual spring shuttles 51 being provided Bolts 4, 5, actuated by pistons 4<1>, 5<1>, are advanced when the shoe support is to be held in its raised and lowered position, respectively. The nail drivers are actuated by a lever 25 connected by a slotted link 24 with a crank on a cam 15<1> driven from a constantly running gear pump 12 which draws oil from a sump through a pipe 34 and forces it past a non-return valve 30, normally by a pipe 37 to the tank again, when a piston 36 is urged to this position by a spring 60 and is connected to a floating treadle lever 57 also carrying a latch 14 urged to operative position by a spring 56 and co-operating with a draw rod 13 retraction of which causes the cam 151 to rotate once, by known mechanism. The treadle also actuates a ratchet 63 engaging in turn pins on a disc 21 connected to a control valve 23. A second ratchet 20 is actuated by a latch 17 having a push rod actuated by the cam 15<1> and co-operating with a link connected by a lever 49 with a slotted link 48 actuated by the piston 6<1>. In operation, with the parts in the starting position shown, a shoe is positioned on the stand, the heel to be attached being held by the operator, and the treadle 43 is partially depressed. The draw rod 13 being urged upwardly by a strong spring 64, the treadle pivots about the point 58 and the piston 36 is raised to close the passage 37 and cause pressure liquid to pass by the valve 23 to the piston 3<1> to depress the tread abutment and to the underside of the piston 7 to hold this firmly in its uppermost position. The treadle is then further depressed, pivoting about the point 39 and withdrawing the bolt 13, the lever 25 then causing the nails to be driven. An adjustable pressure release valve 31 may yield during this drive. As the cam 151 completes its rotation, the latch 17 is released, causing the pawl 20 to rotate the valve 23 one quarter turn. Pressure fluid is thus diverted to the opposite sides of the pistons 3<1>, 7, and the bolt 4 is withdrawn to allow the shoe support to descend. When the piston 7 is nearly at the bottom of its cylinder, a pipe 44 admits pressure fluid to the piston 5<1> advancing the bolt 5 to prevent the spring 14 raising the piston. On movement of the piston 5<1>, a passage 45 is uncovered and a piston 6<1> moved to advance the nail feed block 6 to deliver a new gang of nails to the shoe support, the shoe having been stripped therefrom by the guard plate on descent of the support. The link 48 repositions the latch 17, and finally the piston 54 frees the latch 14. The spring 60 is thereby permitted to lower the piston 36 and simultaneously turn the member 21 to return the valve 23 to starting position. On release of the treadle, the latch 14 is reengaged by the spring 56. Partial depression of the treadle will then raise the plunger 36 returning the nail feed block and retracting the bolt 5 to allow the parts to return to starting position. The piston 5<1> has a non- return valve, and a lateral opening allowing the piston 6<1> to return after complete retraction of the piston 5<1>. When the parts have been returned to starting position, the treadle is released until a new work piece has been adjusted on the shoe support, when the cycle is repeated.