GB363515A - Improvements in or relating to drawing instruments - Google Patents

Abstract

363,515. Drawing-instruments. GESS. NER, E. A., 4, Wettinerstrasse, Aue, Erzgebirge, Germany. Dec. 31, 1930, No. 39271. Convention date, Dec. 31, 1929. [Class 97 (iii).] In a section-lining apparatus comprising a slide carrying an angularly adjustable rule and adapted to move along a T-square either in steps by means of a swinging lever coupled with a rack drive or freely by hand, the slide runs between two U -shaped guides on the T-square and is guided by the two free flanges of the guides. A T-square blade 20 carries parallel guides 21 along which slides a channel-shaped sheet-metal member 25. An arm 30 secured to one side of the member 25 carries a protractor disc 32 having pivoted thereto at 35 a rule 34 which may be secured in any desired position by a clamping screw passing through the slot 33. Two racks 40 on the T-square blade 20 engage toothed wheels 42 rigidly connected with one another by the sleeve 43 and rotatably mounted on the pivot 44 in the member 25. Upon the sleeve 42 a wheel 50 is mounted fast and a fork 52 carrying a handle 54 is mounted loose. Displacement of the member 25 is effected by rotating the handle 54 against the action of the spring 63 in the direction of the arrow, Fig. 4. A resilient locking lever 55 on the handle 54 engages a groove in the wheel 50, causing the latter and the toothed wheels 42 to rotate with the handle. To adjust the amount of displacement the freedom of movement of the handle 54 is controred by adjustable stops 60, 61. The locking lever 55 may be pivotally mounted to enable it to be permanently swung out of action. In a modification the handle 54 connects with the wheel 50 by pawl and ratchet mechanism.