GB191517663A - Improvements in and relating to Dividing Engines. - Google Patents

Abstract

17,663. Endacott, D. Dec. 17. No Patent granted (Sealing fee not paid). Dividing - engines.- In a dividing-engine of the type in which the work is clamped to a graduated circular rotatable plate adjusted for fine divisions by means of worm gearing, means is provided for facilitating repetition of small adjustments, and a coarse adjustment is provided for use when the fine adjustment is out of gear. Improved tool-carrying parts also are described. The graduated plate 12 is fitted with clamps 77 for the work, and is provided with peripheral worm teeth 13 engaged by a tangent screw 18 mounted in a pivoted bracket 15. The bracket is held in position by a spring 19, but may be moved to disengage the screw by pulling out a cam-lever 20. A ratchet 22, Fig. 5, is secured to the shaft 14 of the screw 18 and is engaged by a pawl 24 carried by a drum 23 loose on the shaft 14, a screw 25 on a spring pin being provided so that the shaft may be caused to rotate with the drum in both directions if desired. A handled plate 27 carrying an adjustable stoppin 33 is clamped by a screw 32 in any desired angular position on the drum, the face of which is graduated, and the periphery of the drum is provided with a spiral groove 35 in which rests and travels a knife-edge 40 mounted on a spring arm 37, Figs. 2 and 3, hinged to an arm 39 pivoted to the base-plate. The stop-pin 33 is adjusted according to the length of arc to be set out, and the knife-edge is placed at the end of the spiral slot. The drum is then rotated to advance the screw until the knife-edge meets the stop-pin, whereupon it is rotated in the reverse direction to bring the knife-edge back to the end of the slot. In this way small adjustments, determined by the setting of the stoppin 33, may be repeated. In order to effect movement of the plate 12 through wide arcs, the screw 18 is disengaged, and an adjustable or spring pin 44 carried by an arm 41 rotatable about the axis of the plate is engaged with holes in the plate set at suitable angular distances apart, the arm 41 being moved between stops 46 adjustable on the base plate. A separate plate to be used in place of the plate 12 for special angular distances may be drilled with holes to receive the pin 44, while in position on the plate 12, the drill being carried by a bridgepiece secured to lugs 49 on the base-plate. The marking-tool 56 is mounted on links 54, 53, Fig. 3, the pivot 63, Fig. 7, of the link 53 carrying adjustable arms 64, 65 adapted to come into the path of adjustable stops 74 on a shaft 66 set by a head 67, Fig. 2, to limit the length of the stroke. The tool may be adjusted within its holder 57, Fig. 8, by a screw 62, a bush 58, and a nut 61, and the links 54, 53 are carried by a plate 51 adjustable radially on a standard 50. According to the Provisional Specification the tool may be carried by a long arm mounted on a universal joint adjustable in a slotted plate parallel to a tangent to the graduated plate, and may be adapted to mark in any direction on horizontal or vertical surfaces, and an index pointer may be used in connexion with the coarse adjustment.