Patent GB-190422884-A (GB)
Title: Improvements in or relating to Punching Machines.
Inventor: BOULT ALFRED JULIUS
Filed: 1904-10-24
Granted: 1905-10-24
Abstract: 22,884. Boult, A. J., [United Shoe Machinery Co.]. Oct. 24. Punching a n d perforating machines.-Relates to a machine for forming ornamental or other perforations in boot toe-caps and other articles, the main object being to preserve a constant distance between successive perforations when these lie on a curve as well as when they are on a straight line. This is accomplished by causing the presserfoot to engage the work at a point in the line of feed, instead of at a point to one side of it. The punch 34, Figs. 1 and 4, is secured by a pin 35 to a plunger 8, which is reciprocated vertically by a cam 6 on a rotating shaft 4. When the plunger reaches the lowest point of its travel, it is retracted slightly, in order to relieve the pressure upon the worksupport, and is moved forward, so as to feed the work, by a lever 18, which is pivoted to the sleeve 14 carrying the plunger and rocks about a fulcrum 25, being actuated by a cam on the shaft 4. For this purpose, the sleeve 14 is pivoted to the shaft 4 so as to rock under the action of the lever 18 and spring 11. The punchings are discharged from a tube 36. When the punch is about to be withdrawn from the work, the presserbar 42, Fig. 6, is forced down by a spring 47, Fig. 1, and the point of the presser-foot 40 holds the work at a point in the line of feed about midway between the ends of the lateral movement of the punch. The punch then rises, is moved laterally over the presser-foot 40, and is forced into the work again. The presser-bar is then raised by a cam acting on the bent lever 44, Fig. 4, to which it is connected, and the point 54 of a lever 50, Fig. 6, pivoted to it at 51, strikes an adjustable stop 56, thus causing the presser-foot 40, which is slidably mounted on the presser-bar, to be drawn back out of the line of feed against the action of a spring 58. The punch then feeds the work forward again as described above. The presser-bar may be held up by a treadle connected with the lever 44. In order that the feed may be varied, the fulcrum 25, Fig. 4, is fixed to a sliding block 22, which may be clamped at the desired point by a screw 29. To enable this adjustment to be performed with accuracy, the block 22 is attached to the end of a lever 64, which is pivoted to the frame at 65 and engages a piece 62 sliding in an inclined slot 69. To adjust the feed, the piece 62 is moved to the desired point on a scale 67, the lever 64 is brought into engagement with it, and the screw 29 is tightened. In order that the vertical movement of the punch may be adjusted, the roller 27, Fig. 5, which engages the cam 6, is mounted upon an eccentric-pin 26, which can be rotated by a handlever 28 provided with a clamping-screw 30. A forked work-guide 66, Fig. 7, moves in a slot in the machine table, and can be drawn back by a pivoted hand-lever 75 to which it is connected. The end 70 of the slot is inclined, so that the work-guide may be pressed down below the level of the table if drawn back sufficiently. To promote effective punching without causing the punch to strike the punch block, a non-metallic, flexible strip 72, Fig. 12, is interposed between the punch block 3 and the work, and is fed forward with the latter. The strip is stored on a bobbin 77, Fig. 8, passes over a guide-roller 78, through a tube 80, Fig. 12, round a roller 82, through a tube 83, over the block 3, and back to a bobbin 89, Fig. 8, which is rotated slowly as the strip is fed by a friction pulley 90 driven by a band from the main shaft. In order that the strip 72 may be used several times, the guide-tubes 80, 83 and the roller 82 can be moved laterally by a screw 177.