Patent GB-210103-A (GB)
Title: Improvements in typewriting machines
IPC: B41J1/04
Filed: 1922-07-25
Abstract: 210,103. Marks, E. C. R., (Royal Type writer Co., Inc.) July 25, 1922. Paper-carriages; platen-shift mechanism; letter-spacing mechanism.-In a front-strike typelever machine, a shiftable platen-frame is mounted, for instance by means of parallel links, on a carriage running on a rail which is provided with means for effecting fore-and-aft adjustment; the rail may be supported at the ends on the side walls of the framework, and at the middle on a frame which carries the escapement mechanism and is secured to the rear wall of the framework. A platen frame 8 is mounted on a carriage 7 supported at the front. on a stationary rail 4 secured at each end to a block 32, Fig. 7, having tongue- and-groove engagement 34 with the side walls 1 of the framework, and formed with a fork 33 engaging an eccentric disc 36 on a stud 35 which can be turned to adjust the rail. The studs are secured bv means of nuts 37. The blocks 32 are secured to the rail bv means of binding-screws 39 and dowels 38. The rail is supported at the middle by means of a frame 5, Fig. 16, having arms 25 secured to the rail, and a plate 23 to which is secured a support 6 for the escapement wheel 44, an angle-plate 28 on the support being adjustably secured to a bracket 29 on the rear wall 2 by means of a screw 31 passing through a slot. The carriage 7. comprises side plates 51 connected at the front by a rail 50, and at the rear by a rock-shaft 53, and rods 57, 58 for the margin and tabulating-stops. The rails 4, 50 have races 67 receiving balls 62, the grooves being formed with dust-catching grooves. The rail 50 is provided with retaining-fingers 59, Fig. 7, having curved lugs 61 engaging the rail 4. The carriage is supported at the rear by means of rollers 41, 42, Fig. 16, which are mounted on the support 6, and engage the rock-shaft 53. The platen frame 8 consists of a channelled member 80, connected to side plates 83, Fig. 7, by means of screws 84, 85 passing into blocks 82. Cushioned stops 89 on the platen frame rest on the rail 50. The stops each abut on a pad of leather &c. contained in a cup 87 which is formed with a lip engaging the stop, the cup being placed in a recess 86 in the block, and being provided with a screw 90 secured by a nut 91. The platen shaft is journaled in the platen frame and passes through slots 92 in the carriage. The platen frame is supported at each end by means of links 93, 97, Fig. 17, the links 97 being pivoted to the carriage, and the links 93 being secured to the rock-shaft 53. A shift rail 172, engaging a roller 175 on the platen frame, is secured to arms 180 which are mounted on rocking-arms 188, 191, the arms 188 being pivoted to the blocks 32, on the rail 4, and the arms 191 being mounted on a shaft. The shaft is connected to shift-key mechanism, preferably that described in Specification 210,104. To permit of vertical adjustment of the shift rail, the arms 180 have wings 181, Fig. 7, which are each secured to the shift rail by means of a screw 185 and a bolt 183 passing through vertical slots in the wing, the bolt having an eccentric head engaging a slot 182 in the wing. The shift rail has arms 178 abutting on the side walls 1. Card - feeding arrangements; platen scales. - The shift rail 172, Fig. 16, may support a bracket 230 carrying a card-holder and a scale, such as are described in Specification 20241/13. Carriage-releasing arrangements.-The feedrack 68, Fig. 17, is secured to rocking-arms 70 engaging cams 74 on the releasing-levers 72. The normal position of the rack can be adjusted by means of the cams. Springs maintain the rack in engagement with the escapement wheel 44, and a spring 78 engage sockets 79 on the levers to prevent chattering. The upward movement of the rack is limited by adjustable stops.