GB862996A - Improvements in straight edges and drawing boards provided with the same - Google Patents

Abstract

862,996. Drawing-instruments. DIXON, E. P. May 27, 1959, No. 18083/59. Class 97(3) [Also in Group XV] A straight edge for drawing boards comprises a bar 4, Fig. 1, having a part 6, Fig. 2, at one end to engage an edge 2 of the drawing board 1 and another part 12, Fig. 7, which may either be secured at the other end by screws passing through bores 13 or at an alternative position adjacent thereto by screws passing through bores 14, the part 6 being adjustable to clamp the edge 2 of the board 1 to hold the bar 4 in adjusted position. By providing two pairs of bores 13, 14, the bar 4 may be slid along either the long edges or short edges of the board 1. The part 6 is clamped against the edge 2 of the board 1 by rotating a finger wheel 9 whose threaded shape meshes with a threaded bore in a part 8 acting, through a somewhat resilient member 11, on the part 6. The parts 6, 12, are shaped to correspond with projections, as shown, on the edges 2 of the board 1, or with grooves thereon, or in the case of boards having flat edges the cooperating parts are made thicker and the part 7, which is secured to bar 4, engages over the under-surface of the board, the part 12 having a similar surface engaging portion. One edge 42 of the bar 4 may be bevelled for use with a pencil and the opposite edge 43 formed as a projection spaced above the drawing surface for use with a pen. Grooves 5, 51, are for receiving a rib or bar on a drawing instrument such as a set square. Specification 862,997 is referred to.