Patent GB-191511277-A (GB)
Title: Improvements in or relating to Wiper-operating Mechanism for Hand Method Lasting Machines.
IPC: A43D21/16
Filed: 1915-08-04
Abstract: 11,277. Jerram, A. E., Keall, F. B., and British United Shoe Machinery Co. Aug. 4. Lasting.-The wiper-operating mechanism of a hand-method lasting-machine, such as of the type described in Specification 14,453/97, is provided with means whereby the position which the wiper has reached when the pincers release their grip on the upper is automatically varied in accordance with the position of the pincers when the release takes place. Conveniently, these means comprise a device for varying the speed of the wiper, and means connected to the pincer mechanism for automatically adjusting this device as the amount of overdraw varies. Further, there is provided means for causing the wiper, which preferably forms a rigid whole with the tack carrier, to advance from an invariable rearward position to its forward position by a combined forward and lateral movement consequent upon the pincer mechanism being set for pleating. The wiper J<22> is rigidly bolted to the tack block J, Figs. 1 and 2, which is pivotally connected to a member J<1> of a main operating-toggle J<1>, J<2> adapted to be actuated through a link J<3> from a member J<4> mounted on a cam-oscillated shaft J<5>. The tack block is guided by a pivotally-mounted block J<16> and by a member J<6>, which straddles over it and is reciprocated by a toggle J<8>, J9. Normally, this movement of the member J<6> has no effect on the wiper, but when the knee-lever of the pleating-mechanism is moved, it acts through connexions J<13>, J<12>, J<11> with the front of the member J6 to swing this member to one side or the other, and consequently to cause the lock block to sweep over the shoe bottom in a curved path ; the initial position of the tack block is, however, invariable. To vary the speed of the wiper for the purpose referred to above, a supplementary toggle mechanism, controlled by the pincer overdraw mechanism, is provided to move the pivot J" of the main toggle J', J<2> during the movement of the latter by the link J<3>. A rod K' from the overdraw mechanism is connected to a lever K<2> fast on a shaft K<3>, at the lower end of which is fixed a lever K<4> carrying a spring-pressed pivoted pawl K<5>; the movement of this pawl is limited by a stop K<22>. A bracket K", mounted to swing upon the shaft K3 and upon a pivot K<23> in line with the shaft, is provided with a lug K<19> adapted at times to contact with the lever K<4>, and is journaled to receive a shaft K<7>, Figs. 1 and 3, which carries at its upper and lower ends pawls K<6>, K<8> adapted respectively to engage the pawl K<5> and a spring-pressed pawl K<9> loose upon the shaft. A link K<13> is centrally pinned on the shaft K<7> and carries a pin K<14>, the distances from the axis of the pin K<14> to the axis of the shaft K', and from the axes of the pivot K<23> and shaft K<3> to the axis of the shaft K<7> being the same. The pin K<14> is connected to a link K<15>, the other end of which is pivoted to a crank-arm K mounted on a pivot K<25> and connected to the pivot J". A pair of links K<16> connects the member J<4> with the link K<15>. There is also provided a fixed tooth rack K<17> and a fixed stop K<18>. In operation, as the rod K<1> is pulled during the overdraw, the pawl K<5> bears upon the pawl K<6> and swings the frame K" about the shaft K<3> and pivot K<13> to an extent depending upon the amount of overdraw, the pivot pin K" remaining, however, in alinement with the axes of the shaft K<3> and pivot K<23>. At the end of the overdraw, the member J<4> begins to move to actuate the toggle J', J' for the advance of the combined tack block and wiper, and at the same time, the links K<16> exert a push on the link K<15> to displace slightly the pin K<14>, which allows the pawl K<8> to release the pawl K<9>, and the latter then engages the rack K<17>. This temporarily fixes the shaft K<7>, and continued movement of the member J<4> swings the pin K<14> farther away from its normal position, which results in the toggle links K<13>, K<15> being gradually straightened, so that the crank K is swung in a direction to aid the link J<3> in straightening the toggle J<1>, J<2>. The speed of the wiper is therefore increased. The pincers open just at the moment when the toggle formed by the member J<4> and the links K<16> is straight, and then continued movement of the member J4 exercises a pull on the links K<16>, K<15> and moves the pin K<14> back towards its starting position, so that the crank K acts to retard the straightening of the toggle J<1>, J<2>, and so slows down the advance of the tack block until it reaches tack-driving position. When the pincers release the upper, they spring to the limit of their movement, and the rod K' receives a further pull and swings the lever K' to place the pawl K<5> behind the pawl K<6>. At the end of the advance of the tack block, the pivot K<14> has returned into alinement with the shaft K<3>, and the pawl K<8> has disengaged the pawl K<9> from the rack K". Directly the member J<4> begins to swing back, however, the pin K<14> is again displaced, the pawl K<9> re-engages the rack, and the reverse order of operations take place. Specification 16,627/09 also is referred to.