Patent GB-530359-A (GB)
Title: Improvements in and relating to line-spacer mechanism for typing machines
IPC: B41J19/70
Filed: 1939-06-22
Abstract: 530,359. Typewriters. TRIGGS, W. W., (Underwood Elliott Fisher Co.). June 22, 1939, No. 18190. [Class 100 (iv)] Line - spacing and carriage - returning mechanisms. Power mechanism for actuating the line - spacer, with or without returning the carriage, is started by means of a controlmember on operation of either a line-spacing key or a line-spacing and carriage-return key, and the control-member is automatically restored by means of a power-actuated element such as a floating bar after operation of the former key, or by joint action of the power-actuated element and another element, such as the margin stop, on the carriage after operation of the latter key. In the mechanism shown in Figs. 5, 10 and 15 a motor 104 drives continuously a shaft 113 carrying a loose pulley 118 connected to a tape 119 which passes over guide-rollers 131, 135 and is connected to a pulley 136 on the carriage 29. A clutch 124 for the pulley 118 engages a yoke 127 on a rock-shaft 126 provided with an arm 129 which is connected by a link 152 to a controlmember or lever 153. Normally a latch 157 engages the lever and prevents a spring 151 from closing the clutch. The lever is connected by a link 173 to another link 175 which can slide in a bracket 71, the links constituting a toggle. The line-locking lever 66 is pivoted to a link 180 having a slot 179 engaging a pin 178 on the link 175. The pulley 136 is provided with a gear 139 co-operating with a gear sector 140 formed on a cam 142 which co-operates with a roller 143 on the line-spacing lever 46, a pawl carried thereby co-operating with a ratchetwheel on the platen 43. The cam is formed with three steps corresponding to single, double, and treble spacing and, to overcome the inertia of the detent-roller for the ratchet-wheel, each step is so formed that a large initial part thereof effects only a small movement of ratchet-wheel. Movement of the pulley 136 is positively limited by a floating bar 166 which is mounted by means of inclined slots 167 on pins 169 on the carriage, and is provided with a hook 165 for engaging a pin 164 on the pulley. At lineend, the line-lock stop 62 engages the line-lock lever 66 and moves it into contact with the left side of the guide-slot 69, the movement being transmitted to a lever 79 associated with crowding-rollers 88 for locking the keyboard. On depressing of the carriage-return key 161, the lever 160 thereof rocks the latch 157 and releases the lever 153, the clutch 124 is closed, the tape 119 is wound on and off the pulleys 118, 136, and line-spacing is effected by co-operation of the cam 142 and roller 143. The bar 166 is depressed by the pin 164 and, when arrested by the pins 169, arrests the line-spacing devices and permits the tape to return the carriage. During depression, the bar 166 engages a nose 183 on the link 173 and straightens the toggle 173, 175, thereby causing the pin 178 to move to the left end of the slot 179. When the margin stop 63 engages the line-lock lever 66, the latter is moved into contact with the right side of the slot 69, the link 180 acts through the straightened toggle to return the lever 153 into engagement with the latch 157, and the clutch is opened. If the carriage-return key is depressed before the line-lock stop 62 engages the line-lock lever, the latter remains temporarily in normal position. When however the toggle is straightened by means of the bar 166 during line-spacing, the line-lock stop lever is moved towards the left and when engaged by the margin stop 63 co-operates with the toggle to return the lever 153. If the carriage-propelling spring is not strong enough to retard the carriage until line-spacing is effected, the carriage is returned and, when the margin stop engages the line-lock lever, the line-spacing mechanism is operated and the lever 153 is returned in the above-described manner. To provide for latching the lever 153 if the carriage-return key is held down, the latch 157 is provided with an auxiliary, pivoted latch 187 which is slightly below the latch 157 and is normally pushed aside thereby. To ensure engagement of the lever and latches, the lever may be given a slight, extra returnmovement by the momentum of a weight 193 thereon, and the cam 142 may have a dwell for engaging idly the roller 143 during the extra movement. If the carriage-return key is again depressed after the margin stop has engaged the line-lock lever, the line-spacing mechanism is again operated, the operation occurring whether or not the letter-spacing escapement has permitted a drop-back of the carriage after arrest by the line-lock lever. The carriage-return lever 160 has a lug 214 for depressing the lever 79 to lock the keyboard. If the lever 160 is released, the bar 166 maintains the lock. A key 197, Fig. 15, for line-spacing without carriagereturn, is carried by a lever 196 which is arranged to release the latch 157, and is connected to a link 201 having lugs 206 for blocking the line-lock lever 66, and a lever 101 in connection with the margin-release key 98 and the line-lock lever. The lever 197 is arranged also to rock a lever 208 for locking the escapementwheel 33 and thereby preventing return of the carriage. On depression of the key 197, the latch 157 is released and, the line-lock lever and the carriage being blocked, the tape 119 operates the line-spacing mechanism, without returning the carriage. The toggle 173, 175 is straightened by the bar 166 and, by abutting on the lever 66, returns the lever 153. The lever 197 of the line-spacing key has a member for engaging the rollers 88 to lock the keyboard.