Patent GB-483881-A (GB)
Title: Improved carriage stop mechanism for typewriters
IPC: B41J29/50
Filed: 1937-03-31
Abstract: 483,881. Typewriters. FAIRWEATHER, W. C. (Underwood Elliott Fisher Co.) March 31, 1937, No. 9122. [Class 100 (iv)] Margin stops; line-locking devices.-Stops for limiting travel of the carriage in letterspacing and return directions are normally in the range of a counterstop and are supported by a bar which can be turned to adjust simultaneously both margins. The bar may carry pairs of stops on different faces, or may be provided with right-hand and left-hand threads for adjusting one pair of stops. In the mechanism shown in Figs. 1 and 12, a bar 70, trunnioned in brackets 71 on the carriage 39, supports adjustable margin-stops 76 .. 81, each of the pairs 76, 77, 78, 79 and 80, 81 projecting from a different face of the bar. The stops consist of a yoke 91, Fig. 2, formed with teeth 92 and provided with a cross-screw 93 for engaging teeth 90 on the bar. The bar is turned by means of a knob 73 to bring a selected pair of stops to the bottom for co-operation with a counterstop 101. The bar is provided with an index-drum 74, and a star-wheel 86 which co-operates with a spring-urged detent 87. The counterstop 101 is formed on a plate 99 having a slot 100 engaging a pin 98 on a shelf 96 forming part of a bracket 94 secured to the shiftable carriage-support 42. The counterstop passes through a slot 97 in the shelf, and is urged forward and to the right by a spring 102. A lug 130 on the plate 99 engages a finger 127 on an arm 125 of a bell-crank 131 which is mounted on trunnions 133, 134 in a yoke 142 and is connected by a link 135 to a keyboard-looking bail 136. The yoke is secured to a cranked spindle 141 which is mounted in the framework 30 and engages a marginrelease key-lever 138. At the end of the letter-spacing movement of the carriage, the selected stop 76, 78, or 80 engages the counterstop 101, the plate 99 and arm 125 are moved towards the left, and the bail 136 is moved into engagement with hooks 37 on the key-levers 32 to lock the keyboard. On depression of the margin-release key, the arm 125 and plate 99 are swung rearwards, and the carriage can move into over-margin position. On return of the carriage, the selected stop 77, 79 or 81 engages the counterstop, the plate is moved until the counterstop engages the right-hand wall of the slot, and the carriage is arrested. Depression of the margin-release key permits the carriage to move into over-margin position. For cushioning the return movement of the carriage, the counterstop is arranged to abut on a stiff spring 105, Fig. 12, which is secured by a screw 107 to the shelf 96. The stops 76 .. 81 are formed with bevels for displacing the counterstop when the carriage returns from over-margin positions. When the bar 70 is set with the blank face at the bottom, the usual margin-stops 66, 69 may be employed, the arm 125 having a finger 126 for co-operating with the stops. In some cases, the bar 70 is provided with a pair of margin-stops on each face and, to permit of optional use of the margin-stops 66, 69, a finger-piece 118, Fig. 12, is provided for holding the counterstop 101 out of the path of the stops on the bar 70. The fingerpiece is formed on a bell-crank 116 having a pin 115 co-operating with a hook 114 on the plate 99. A resilient arm 119 in connection with the bell-crank has a projection 123 which co-operates with a recess 122 to hold the bellcrank in normal position. In the mechanism shown in Fig. 26, a shaft 164, journalled in the carriage 39, is formed with right-hand and left-hand screw-threads 165 engaging stops 169, 170, each comprising a threaded collar 172 and a flange 173 having a notch 181 engaging a scale 182 on the carriage. The pitch of the screws 165 is equal to four letterspaces, so that by turning the shaft through a quarter-revolution by means of a knob 73, the stops 169, 170 are moved through one letterspace in opposite directions. The shaft is retained by co-operation of the square-end thereof with a spring 166. To withstand shock, the screws are formed with quadruple threads. The stops 169, 170 are formed with stop-faces 175 co-operating with a counterstop 126 to determine the left and right hand margins. The counterstop is formed on a slide 236 which is mounted on a pin 239 and is connected to a spring 234. The slide is formed with a lug 243 engaging a lever 245 which is connected by a bell-crank 248 and spring-link 250 to a keyboard-locking bail 136. At the end of the letter-spacing movement of the carriage, the stop-face 175 on the stop 170 engages the counterstop 126, the slide 236 is moved leftwards, and the bail 136 is moved into position to lock the keyboard. To permit of movement of the carriage into over-margin positions. the lock is released by pressing a button 254 which is connected by a push-wire 255 to a bell-crank 240 engaging the slide 236. Return movement of the carriage is limited by engagement of the stop-face 175 of the stop 169 with the counterstop 126. The button 254 is pressed to permit of movement of the carriage into over-margin position. The stop-faces 175 are formed with bevels for displacing the counterstop when the carriage returns from overmargin position. Tabulating - mechanism.-For indenting, the mechanism shown in Fig. 26 includes a stop 171 which is mounted on a plain part of the shaft 164 and is adjustably connected to the stop 170 by means of a bar 185 formed with a series of holes for receiving a screw 186. The stop 171 co-operates, on depression of the tabulating-key 143, with a stop-lug 180 on a lever 210 engaging a lever 203 having a pin 202 which co-operates with a slide 200 in a slide 195 connected to the tabulating-key lever 193. The lever 203 abuts on a bell-crank 215 connected. to a bell-crank 217 for swinging the feed-rack 53 to release the carriage. The stop 169 is formed with a face 177 which can co-operate with the stop-lug 180 for indenting. Alarms.-A rotatable striker-rod 121, Fig. 1, for the line-end alarm 61 has a finger in the path of the margin stops 76, 78 and 80. If, during turning of the bar 70, one of the stops strikes the finger, the rod can move downwards in its support 156. The arm 119, Fig. 12, is provided with a pin 120 for moving aside the striker-rod when the counterstop 101 is disabled. The stop 170, Fig. 26, co-operates with a one-way dog 228 on a bell-striker 232.