442,517. Boot-making machines. UNITED SHOE MACHINERY CORPORATION, Paterson, New Jersey, U.S.A.-(Assignees of Standish, J. F. ; Winthrop, Massachusetts, U.S.A.) July 7, 1934, No. 19960. Convention date, Aug. 25, 1933. [Class 17 (i)] Heels, machines for.-In a heel-attaching machine the pressing member forming the clamp and abutment for the tread face of the heel during the driving of the attaching nails is connected to a member taking the reaction from the thrust of the nail drivers, so that the abutment is pressed toward the drivers with a force dependent on the resistance to the drive. A tight crease is thus ensured with no more than necessary pressure, which varies according to the work. Improved loader block mechanism is provided, which can be mounted at either side of the jack. An adaptor is provided, for facilitating change of jack. The column 10 of the machine carries at its top a cap 12 having trays 14 for receiving nails dropped, thus preventing them entering the working parts. A similar tray 16 is positioned at the rear of the column. Guides on the cap position an exchangeable adaptor, Fig. 9, held in place by a spring plunger 25 engaging a bore in the front of the base-plate of the adaptor. Exchangeable jacks are provided, each having a pin 30 co-operating with a socket 28 in the adaptor, a clamping screw 32 engaging a recess in the pin. Nail drivers 34 are carried by a plate recessed to receive the cylindrical top of a screw 40 rotatable in a threaded bore in the top of a plunger 44 for adjusting the height of the drivers, a spring plunger 59 engaging a recess to maintain the screw in adjusted position. A sleeve 51 guides the plunger, and has threaded on it a collar engaging the upper end of a spring 46 abutting on a washer normally resting on a step in the column and also a shoulder on the plunger. The collar is rotated to adjust the strength of the spring. The plunger is provided with a roll 98 engaging a cam 96 on a shaft driven by an Oldham coupling 102 from the main shaft 88. The cam shaft rotates in a bearing block 92 guided for vertical movement and normally held in its uppermost position by springs 100. Carried by the block is a tubular piston 104 having at its lower end a normally open valve 106 with a stem 110 engaged by the cam, the piston working in a cylinder 64 containing oil. The cylinder 64 is carried by side rods 52 guided to move vertically, normally held at their uppermost position by a spring 70 and carrying at their upper ends arms 54 carrying the tread face abutment and presser member 58. In operation, appropriate nail drivers, adaptor and jack having been inserted, a shoe is positioned on the jack and the treadle 76 partially depressed. At this time the valve is open and the cylinder 64 can move down freely under the pull of a link 78, bringing the member 58 down on to the heel to clamp it in position. Further pressure on the treadle causes this to pivot about the link 78 elevating a link 82 and throwing in a one revolution clutch as described in Specification 186,126, [Class 17 (i)]. On the cam 96 commencing to rotate the valve 106 is closed and the thrust of the drivers is communicated to the cylinder 64 causing the presser 58 to engage the heel more firmly. To prevent overthrow, the block 92 carries a fibre block 126 co-operating with a stop member 124 adjustable along an inclined surface 120 on the column 10. Nail loading mechanism may be positioned at either side of the jack. The cap 12 has at each side a socket for a spindle 132 which can be clamped in the socket and carries a rotatable sleeve 142 provided with a lug 144 the ends of which co-operate with a fixed pin 146 to determine the nail receiving and nail delivering positions of the loader block. To the sleeve is pivoted on a horizontal pivot, a loader arm 154, a spring 156 connecting the arm with a pin eccentric on the spindle 132 arranged so that the spring passes over dead centre as the arm moves and holds it in either extreme position. The arm 154 carries an arm 160 itself carrying a frame 162, adjustment being provided by screws 158, 164 passing through slots at right angles. A loader block 168 slides in the frame and is exchangeably held in position by a spring plunger 174. A nail retaining shutter 177 is urged to normal position by a spring 180 and is provided with a screw contacting with the jack as the block reaches delivering position, to move the shutter to align the nail passages 178, 170. The pivoted arm 154 allows the block to rise should the machine be operated with the block above the jack. The lug 144 engages a recess in the adjacent rod 52, to prevent the member 58 being depressed unless the loader block is in nail receiving position.