Patent GB-190320914-A (GB)
Title: Improvements in Methods of Making Shoes, in Lasts for Practising the same, and in Machinery and Methods for Making Lasts.
Inventor: PRINDLE EDWIN JAY
Filed: 1903-09-29
Granted: 1904-08-18
Abstract: 20,914. Prindle, E. J. Sept. 29. Lathes; chucks.-Fig. 16 shows a turning-lathe for making interchangeable parts of hinged or other lasts used in shoe manufacture, and Figs. 24, 26, and 27 show the form of chuck employed for holding the model F and the block G from which the last is to be formed. The hinge face of the last part, or other standard surface of the last, is first formed on the block G, and is provided with four studs, which are engaged in the recesses h<8>, Fig. 26, of the movable plugs h<7> in the chuck head h<6>. The plugs h<7> are then turned into the positions shown in Fig. 27, so that the studs cannot become disengaged, and are drawn back until flush with the plate h<20>, their inner ends h<18>, which are cut away as shown, being then engaged with correspondingly-cut pins h<19> fixed in the head h<6>. The movements of the plugs h<7> are effected by the draw-bar h<14> which passes through the hollow spindle h. The draw-bar is connected to the plate h<12>, which is provided with pins engaging in spiral grooves h<17> in the stems of the plugs, to effect the partial rotation of the plugs, the subsequent longitudinal movement of the plugs being effected by the plate h<12> engaging the collars h<11> on the plugs. The model F is similarly mounted. This arrangement permits the cutter to work over the toe &c., as well as the lateral contour, of the last being formed. The spindles h, h<1> of the model and block, and their driving-shaft h<5>, are mounted in the swinging frame H pivoted at the upper end of the standards h<2>. The model wheel and the cutter are mounted on sliding carriages D, E and driven in the usual manner. Provision is made for making the last longer or shorter, or wider or narrower, than the model, this provision also enabling a series of lasts of predetermined sizes to be made from each model. The longitudinal grading is effected by altering the relative speeds of the carriages D, E. For this purpose, the carriage E is pivotally connected by the rod I to the lever K, which is pivoted at k' and connected by pivoting blocks k<6> to the slide-way k<9> on the carriage D. The pivot k' may be made capable of adjustment by means of a screw k<5>, as shown. The block k<6> in the slide-way k<9> is adjustable by means of the screw k<10>, to regulate the relative speeds of the carriages D, E. For producing a series of lasts from the same model, the screw k<10> is provided with a pointer k<11> for use with the scale k<12>, Fig. 32, which is mounted on the cylinder k<13>, Fig. 16, with the central line 7 of the scale horizontal. The model F is placed between the fixed step k<16> and the movable step k<15> connected to the pointer k<14>, and the cylinder k<13> is then adjusted so that the diagonal line k<18>, Fig. 32, which is co-ordinate to the lengths of the different models, is under the pointer k<14>, after which the pointer k<11> is adjusted by the screw k<10> to one of the size-lines k<17> of the scale, according to the particular size desired. For grading the width of the lasts, a somewhat similar arrangement is employed, but the adjustable lever (corresponding with the lever K) is adapted to vary the relative movements of the model carriage and the model-wheel slide. For the purpose of imparting a relatively - slow movement to the model wheel and cutter during the shaping of the toe or heel, the shaft L, which drives the cutter carriage E, is driven from the pulley l through the epicyclic change gearing shown in Figs. 33 and 35. The pinions l<8>, l<9> are fast with the pulley l and shaft L respectively, and gear respectively with two integral pinions l<6>, l<7>, which are mounted on the pin l<5> on the arm P. This arm is provided with a spring-controlled pawl l<2> adapted to engage the internal ratchet-wheel l<1> on the pulley l. During the slow movement of the carriages, the pawl l<2> is held disengaged by the bar l<11> connected to the carriage D, the shaft L being driven through the gearing l<8>, l<6>, l', l<9>. When the pawl is released by the bar l<11>, it locks the arm l<3> to the pulley l, so that the shaft L then rotates with the pulley. The model and block are mounted parallel to each other, the model being positioned so that certain points, such as the ball and heel of the model, are equidistant from the axis, thus ensuring that such points will be also equidistant from the axis in the last, independently of the length of the last. To obviate disconformity between the toe and heel parts of the last, from distortion due to the inertia and spring of the swing frame H, the heel part is rotated in the lathe in the opposite direction to that in which the toe part is rotated, so that the distortions become coincident when the toe and heel parts are put together.