GB840959A - Improvements in or relating to draughting machines - Google Patents

Abstract

840,959. Draughting machines. REPPISCHWERK A. G. March 2, 1959 [March 3, 1958], No. 7243/59. Class 97(3) In a draughting machine having wheels 1, 2, 3, 4, Fig. 1, at the joints of a parallelogram linkage, which are connected to each other in pairs by flexible bands 5, 6, 7, 8, each pair of wheels 1, 2, and 3, 4, is connected to each other by two open bands 5, 6, and 7, 8, one end of each band being passed clockwise and the other end anticlockwise round the adjacent wheel and firmly connected thereto. Each band is in a different plane A-A, B-B, C-C, D-D, Fig. 3, from the adjacent bands and each wheel 1-4, has two . beds to receive the two bands. The wheel 4 is on a plate 20, Fig. 5, hinged at 21 to a part 16 rotatable about an axis 22 on a second part 15 clamped to the drawing board, so that the whole draughting machine may be hinged about axis 21 away from the board when required and by rotating part 16 with respect to part 15, and then firmly holding in the adjusted position, the draughting machine may be fixed to the board in any position. The protractor head 17 is connected by arms 18 to a disc 19, Fig. 6, which is coaxial with wheel 1 and has a tapered recess 19a engaging a cone 1c on the wheel 1 so that by moving an eccentric lever 23, a bolt 24, and with it disc 19, may be slightly displaced axially to clamp the disc 19 to cone 1c or free it therefrom. The casing 11, surrounding wheel 1, may be provided with a graduated disc and, in a modification, the engagement between the wheel 1 and disc 19 is positive, such as in the form of a notched disc, instead of frictional.