Patent GB-612805-A (GB)
Title: Improvements in typewriting or like machines
IPC: B41J11/00
Filed: 1944-02-28
Abstract: 612,805. Typewriters &c. ROYAL TYPEWRITER CO., INC. Feb. 28, 1944, No. 3696. Convention date, March 24, 1943. [Class 100(iv)] In a typewriter adapted for printing on tapes for use, for example, in the sending or receiving of telegrams, and in which the tape extends along the writing line of a travelling platen with which it is fed during letter-spacing movements, means are provided to move the tape reversely to the normal direction of feed to take up any slack therein. As 'applied to a portable machine, the frame A, Fig. 1, is mounted on legs to provide a space thereunder wherein the supply spool 30, Fig. 5, is mounted. A journal pin 44 secured to a plate 40 situated underneath the frame A carries inner and outer sleeves 50, 51. The sleeve 50 on the pin 44 is rotatably secured by nuts 55 and washers 52, 54, with a spring- washer interposed between the parts 52, 54 so as to exert frictional resistance to the rotation of the sleeve. The outer sleeve 51 is freely rotatable upon a ball-bearing 57 and carries the supporting flange 32 of the supply spool. A pin 68, Fig. 6, on the sleeve 50 is connected by a spring 67 to a pin 64 on the sleeve 51 so that during feeding of the tape the spring 67 is extended until the pin 64 engages a second pin 66 on the sleeve 50 whereupon both sleeves rotate together but impose a frictional drag on the tape due to the mounting of the inner sleeve. If any slack occurs in the tape, e.g., during back-spacing, the spring 67 rotates the spool in reverse direction to take up the slack, this movement being limited by engagement of the abutment 65 on the sleeve 51 with the pin 66. The flange 32 is removable from the sleeve 51 in order to insert a fresh spool of tape. The tape passes over inclined rollers 77, 80. Fig. 1, through the guide member 83, Fig. 16, adjacent to the printing position and extends along the length of the platen 7. A blade spring 98 on one of the arms of the guide member provides an additional frictional drag on the tape. At the left-hand end of the platen carriage, the tape is gripped so as to be fed for letter-spacing in step with the platen movement. For this purpose, the carriage end-plate 100 carries a finger 102, 103 extending backward along the platen, and the usual arm 14 carrying the pawl 16 for line-spacing the platen is formed with a projection 108, Fig. 8, which normally grips the tape against the part 102. Operation of the line-spacing and carriage-return lever 11 causes the projection 108 to release the tape during the return movement of the platen. A plate 106 on the carriage co-operates with the finger 102 to guide the tape, and lips 104, 107 and a headed pin 105 prevent lateral displacement. Buckling of the tape during the return movement due to frictional engagement of the parts 102, 106 with the tape is prevented by a longitudinallyextending guide member 109. The tape may be severed by a cutting edge 112 on the finger 102. The tape is caused to move with the platen during back-spacing by means of a roller 116 carried by a pivoted arm 113 controlled by a spring so that normally the roller is held away from the platen. If the platen is back-spaced by hand, the roller 116. is moved against the tape to press it against the platen by means of a finger piece 120. When a step-by-step backspacing is carried out by means of the usual key-lever 25, operation of the lever causes the roller 116 to move to operative position. A link 141 connects the roller-arm 113 to a cam-plate 139, Fig. 9, pivoted at 136 to the machine frame. An arm 132 also pivoted to the frame is connected by a linkage 130 to the key-lever 25, and depression of this lever causes a roller 138 on the arm 132 first to ride over a cam-surface 146 on the plate 139 to move the roller 116 against the tape and then to engage a second camsurface 147 to maintain the roller in operative position. Upon release of the key 25, the parts return to their initial position. Specification 612,824 is referred to.