Patent GB-662732-A (GB)
Title: Improvements in or relating to typewriters
IPC: B41J3/36
Filed: 1948-01-31
Abstract: 662,732. Typewriters. RENOR, A. Jan. 31, 1948 [Feb. 4, 1947; Nov. 14, 1947], Nos. 2936/48 and 2937/48. Class 100 (iv). In a typewriter having an inclined type segment and an action wherein the key-lever arms are connected to the type-levers without any intermediate lever, these arms are bent off and their bearings are inclined, by a gradually increasing amount from the centre of the machine to both sides, in the direction of the type-lever bearing slots ; the arrangement is such that each key-lever end moves substantially in the plane of its. type-lever bearing slot. Each key-lever and type-lever may be directly connected by a link, and the depressed key-lever link-pivot points may lie on a curve so chosen that the points of intersection of the symmetrical pairs of tangents to this curve at the link-pivot points lie on a straight line. As shown in Fig. 5 (front elevation) the slot bearings 2 of the V-notched key-levers 1 are inclined, and the key-levers are bent off both laterally and vertically, by increasing amounts according to their distance from the machine centre line; wire links 'connect the levers 1 to the type-levers 6, and the segment 7 is so curved that the lateral levers 6 are longer than the central ones; springs between the levers 1 and the base 3 prevent disengagement from the bearings 2 and return the levers to normal position after actuation. The segment 7 has two slots in its underside, Fig. 6, one for the wire axle of the levers 6 and the other for a universal bail 10 connected at 10<SP>1</SP> to the arms of a spring-loaded rocker 15 pivoted on adjustable pointed screws 16 on a fixed segment-supporting bridge 11 which also carries the pivot-pin 14 of an escapement ratchet wheel 13 and its pinion 12 engaged by a toothed rack on the spring-driven carriage; fixed and spring-loaded pawls 19 and 22 on the rocker 15 are alternately brought into engagement with the ratchet wheel 13 as the type-levers 6 press on the bail 10. The rocker 15 also operates the spring-loaded ink-ribbon vibrator 27 and has two arms 23 carrying spring- loaded pawls 25 which operate the ribbon feed wheels 26, these pawls being alternately held out of engagement with the wheels 26 by the usual ribbon-tension-responsive reversing mechanism. The spacing key is mounted on a pivoted strap linked to two bell-cranks whose arms project at 35 through the pawls 25 and whose slotted bearings on the spool shafts 34 cause the pawls 25 to be disengaged from the wheels 26 before the spacing drive is transmitted through the pawls 25 to the arms 23 of the rocker 15. Fig. 8 shows a pressure roller 42 and guide rollers 43 mounted in an apron 41 carried by a rod 45 whose ends, sliding in slots 46 in the carriage side walls 47, are moved against the action of a single central spring 54 by slides 51 having slot bearings 52 on bushes 53 pressed into the walls 47 around the platen spindle 49; the slides 51 are pressed down by the ends 56 of the paper-clamping strap supporting arms 55, there being sufficient lost motion to allow limited raising of the strap without withdrawal of the rollers 42, 43 from the platen.