Patent GB-765388-A (GB)
Title: Shoe end lasting machine
IPC: A43D21/18
Filed: 1955-02-03
Abstract: 765,388. Lasting machines. MASCHINENFABRIK MOENUS AKT.-GES. Feb. 3, 1955 [Feb. 3, 1954; March 31, 1954; April 24, 1954], No. 3283/55. Class 17 (1). In a shoe and lasting machine in which the movement of the last carrier 2 is controlled by a fluid servo motor, the valve of the servo motor is actuated through a link and lever mechanism 11, 12 by the initial inward movement of the carrier, and the carrier is returned to its original position at the end of each cycle through the medium of a connection between the link and lever mechanism and the means controlling the driving of the machine. The carrier shown is pivoted at 3, but may be of the type which reciprocates in a straight guide, and is connected to the servo mechanism by a rod 6 which is adjustable in length. When the carrier is swung pawl 21 engages a resiliently mounted pawl 20, and through 16, 12, 15 moves piston valve 17, 18 to the position shown, so that oil passes from pump 25 through 23, 22 to cylinder 27 and moves piston 26. Piston 28 at first draws oil through duct 71, 74, but when piston 26 is moved pressure is applied directly to piston 28 to pull the jack. Oil returns to the sump from the valve cylinder via pipe 30. At the end of a cycle roller 42 running in cam stop disc 40, included in the driving mechanism, falls into recess 40a, and through 41, 43, 45, 44, 47, 37, and 35 pivots lever 12 so that rod 16 is pushed to the left, and valve 17, 18 is reversed. Oil then flows through 24 to return piston 80 which moves the jack outwardly until it falls by its own weight. Lever 12 is under the action of toggle spring 49. Oil returns to the sump via 22 and 50. A cycle may be interrupted and the parts returned by pulling lever 55 which actuates valve 17, 18 through 16, 12, 15. When the clutch of the machine is operated by the pressure of a shoe, roller 61 on rod 6, as the jack is raised, moves from 61a to 61b, engaging pawl 67 to rock lever 63 so that clutch rod 41 is raised, and then rod 66 engages the clutch of the machine. Roller 42 engages on the cam of disc 40, and until it falls into recess 40a, locks the clutch. Pawl 67 is held by spring 68 and is deflected when roller 61 returns. If the clutch is to be operated by pedal, lever 63 is made inoperative by pushing and latching rod 69 which tilts pawl 67 to inoperative position. To give the operator time to observe, and, if necessary, correct the position of the shoe, pressure on piston 28 does not reach maximum till the cycle has commenced. This may be brought about by a leak control valve 72 in duct 74 which is opened and closed by lever 73 as rod 41 moves up and down. As pistons 26, 28 advance valve 72 is open and oil escapes through 71, 74 so that the advance is made under low pressure, but when valve 72 is closed by upward movement of the clutch rod 41 full pressure is applied. Alternatively, valve 72 may be operated through 86, and clamping band operating cam lever 87, by cam 88, so that valve 72 is opened shortly before disengagement of the clutch, i.e. as the clamping band is released. Thus the time for correcting the position of the shoe is lengthened by the interval between the engagement of the clutch and the closing of the clamping band. Spring 81 speeds the return of the jack and also halts the jack for a short time before the final pressure acts, the halt being governed by restricting oil admission through 22 so that piston 26 is stopped shortly after it leaves cylinder 27 until the oil passing through gap 82 balances spring 81. Only after valve 72 has been closed does piston 28 move and compress spring 81.