Patent GB-191506415-A (GB)
Title: Improvements in and relating to Jacks for Supporting and Positioning the Work in Machines used in the Manufacture of Boots and Shoes.
IPC: A43D83/00
Filed: 1915-10-27
Abstract: 6415. Roberts, W. T. B., and British United Shoe Machinery Co. Oct. 27. Work-supports.-In a jack for a fastener-inserting or other machine for use in the manufacture of boots and shoes, described as applied to a loose nailer, a sleeve 8 is mounted for angular adjustment between arms projecting from a second sleeve carried on the screwed upper end of a spindle which extends through the frame of the machine and is connected by a universal joint to a lever; this lever, under the influence of a strong spring, urges the spindle upwards towards the nail-inserting mechanism in the usual manner. The sleeve 8 is formed with a wide flange 10 to support a leather or like friction disk 11, on which rests a flange 13 of an arcual member 12, which is formed with a hollow shaft 14 extending through the sleeve 8 and supported by a light spring 15. This spring holds the flange 13 clear of the disk 11 and the work lightly against the work rest during work feed, but yields during the driving of the nail, so that the flange 13 bears on the disk and prevents any rotation of the shaft 14. Above the member 12 is a carrier 23 provided with arcual flanges 22 located between detachable strips 21 and a series of rolls 19; the extent of swing of the carrier is limited by contact of a boss 30 with an adjustable stud 29. The carrier 23 is formed with flanges 24 ... 27 to support a slide 28, which is formed with inclined guideways to support rack slides 32, 34 integral respectively with the heel and toe posts 31, 33; a lug 35 depending from the slide 34 is adapted to limit the rectilinear motion of the slide 28 by contact with an adjustable stud 36. The slides 32, 34, which are adapted to be moved simultaneously by means of a toothed shaft 39 operated by a hand-wheel 40, are arranged at slightly different inclinations to each other, and are parallel respectively to the lines in which the centres of the opening of the heel-pin holes, and the extreme toe ends of the lasts, would fall if standard lasts of a series were in turn so placed on the jack that the curves of the ball portions of the lasts were approximately concentric. The height of the posts 31, 33 is chosen so that the mean centre for the various ball curves can, by movement of the slide 28, be brought coaxial with the centres of curvature of the arcual guides in the member 12. The heel post 31 carries a heel pin 43 mounted to swing transversely on a pivot 44 in a member 45, which can swing lengthways of the last on a pivot 46. The heel pin is adapted to be locked by the engagement with a serrated face 48 of a similar surface formed on one arm 49 of a bell-crank mounted on the pivot 46. The other arm of this bellcrank comprises a telescopic connexion 50, 51 provided with a hand-grip 55 and with a pawl 52, which can be engaged with a rack 53 on the toe post. In operation, after the initial adjustments of the heel pin and toe post have been made, and the lever 50, 51 operated to lock the toe end of the lasted shoe on the toe post, the work is moved under the nailing-mechanism, and, as the nailing proceeds, the necessary movements of the jack take place along the supports 24 ... 27, the arcual guides in the member 12, about the shaft 14, and about the universal joint at the bottom of the jack spindle, the arrangement described being such that work on the ball can be carried out by little more than a simple swing of the carrier 23. When a different last is used, the shaft 39 is rotated to alter the positions of the toe and heel posts, but the centre of curvature of the ball of the last will still aline approximately with that of the arcual guides when the slide 28 is moved to bring the ball over the centres of the guides. Specifications 18,883/04, [Class 17, Boots &c.], and 25,951/05 are referred to.