Patent GB-867095-A (GB)
Title: Improvements in or relating to apparatus for reproducing lettering or other matter
IPC: B43L13/10
Filed: 1957-07-18
Abstract: 867,095. Pantographic apparatus. MEE, M. July 18, 1957 [July 18, 1956; July 9, 1957], No. 22858/57. Class 97(3)  Letters or other characters represented by lands and recesses in a plate are traced by a member projecting through an overlying plate, the relative movement of the plates being transmitted to a drawing point. As shown, in plan, the characters are formed on a plate which is detachably fixed to an undercarriage 2 movable along rails 1, 1a in the direction of the arrow f 1 . A transparent plate overlies this plate and is formed with a number of holes 5, one for each character, only one of which is shown. This plate is secured by pins 301, 302 to a frame 300 displaceable in the direction of the arrow f 2  relatively to the frame 3 which is itself movable in the direction of the arrow f 1  on the undercarriage. A tracing point is inserted in the hole 5 required and moved round the character beneath. Relative movement of the frame 300 and the undercarriage in the direction of the arrow f 2 , representing the relative movement of the plates in that direction as the character is traced, is transmitted to the drawing point 16 through a link. 19 pivoted at 37 to a lever 32. The latter is pivoted alternatively at 33 or 34. By placing a pivot pin 303 in one or other of these positions to engage slots 35 or 36 in the undercarriage a reduction or magnification of the relative movements of the plates is transmitted to the drawing point, the ratio being determined by the position of a pivot 29, attached to the frame 300 and adjustable along the lever 32. The relative movement of the plates in the direction of the arrow f 1  is similarly transmitted by a lever 38 pivoted on a pin 304, which may be inserted in alternative holes at the ends of the lever to engage slots 39 or 39a, and coupled through a longitudinally adjustable pivot 41 to a link 18 coupled to the drawing point 16. The latter may be a bifurcated drawing pen with an ink feeding device 17 and is normally held out of contact with the drawing surface by a cranked member 20 urged upwards under the link 19 by a coil spring 20, but may be lowered by depressing a button 22. The apparatus may be aligned on the drawing surface initially by means of a ruler movable parallel to the rails 1, 1a between an inoperative position 24 and a position 24a where it represents the base line on which the characters will appear. As each character is drawn the under carriage is held in position on the rails by a brake shoe 9 on a lever 10 movable about the pivot point 11, to release the brake for movement between successive characters, by pressure from the end of a lever 12 pivoted at 13. The lever 12 is actuated through a spring 14 by pressure on a button 7 which also moves an endless cord 6 until an abutment 61 thereon strikes an arm 58 projecting from a saddle shaped member 60 embracing the rail 1a, thereby jamming it on the rail. It then acts as an abutment to stop movement of the undercarriage when engaged by a projection 56 on a pivoted arm 54 adjustable by a screw 57. The transparent plate formed with the holes 5 in the above arrangement may be replaced by a system of bars formed with the holes in the required positions. Each of such positions may carry a key, by depressing which a follower member is lowered into engagement with the character below. In another embodiment the tracing movements are transmitted to the drawing point through an orthodox pantograph linkage of adjustable ratio. Another embodiment has a simple transmitting linkage providing for a change of scale in one direction only.