Patent GB-688289-A (GB)
Title: Power operated typewriter
IPC: B41J7/94
Filed: 1950-06-09
Abstract: 688,289. Typewriters &c. REMINGTON RAND, Inc. June 9, 1950 [June 25, 1949], No. 14493/50. Class 100(iv) Keyboards; key actions.-The individual typeactions of a power operated typewriter are actuated by a power arm 20 supported independently of the type action and carrying an eccentric 35 normally maintained out of contact with a power roll 8 but upon the operation of a key the eccentric 35 engages the power roller to effect the operating movement of the power arm 20. The independent support for the power arms and the eccentrics allows then to be installed in the typewriter as a unit. In the example illustrated in Figs. 2, 5, the power arms 20 are operated from their respective key levers 85 pivoted on spindle 86 and guided by a comb-plate 88. Each lever 85 has a pin 91 engaging a rocker 65 carrying a trigger 68 urged anticlockwise on its pivot 69 by a spring 73 until limited by a pin 71 on the rocker 65 engaging on the side of an aperture 70 in the trigger. Depression of a key causes trigger 68 to move upwardly and a shoulder 75 thereon coacts with a lug 55 bent at right-angles from a trip lever 46 which is thus pivoted clockwise at 47 on the power arm 20 against the pull of a spring 53. A finger 49 formed on the trip lever 46 is, by this movement, disengaged from a pin 50, Fig. 5, on the eccentric 35 pivoted on a stub shaft 36 on the power arm 20. The trip lever 46 thus moves into the dot-and-dash position disturbing the alignment of a pivot 57 of a toggle 56, the pivot 47, and a supporting rod 58 about which a mouthed end of the toggle engages. The break in the toggle produces a downward movement of the power arm 20 about a rod 21 and the eccentric 35 engages the power roller 8, and in being rotated thereby the arm 20 is moved upwardly and a roller 22 on the extremity of the arm engages a cam surface 23 of a crank 24 which is driven clockwise about a pivot 25 to effect a printing stroke of a type bar 5. During the first part of the upward movement of the power arm 20 the lug 55 moves leftwardly along the shoulder of the trigger 58 until it becomes disengaged, and lever 46 is turned anti-clockwise by the spring 53 until stopped by a stud 52. This movement restraightens the toggle mechanism 56, 58, 47 and limits the return downward motion of arm 20 at the starting position where the finger 49 engages with the pin 50 on the eccentric 35. The lug 55 will now have descended in front of the trigger 68 and will not be operated again if the key is held depressed, but with the release of the key lever, spring 73 turns the trigger 68 clockwise and shoulder 75 again positions itself under the lug 55 ready for the next operation. In a modification of the trigger 68, Fig. 15 (not shown), the machine may be arranged to make repeated power operations e.g. carriage return or underscoring when the appropriate keylever is held depressed. The degree of contact between the eccentric 35 and the power roll may be adjusted to collectively vary the impact of all the type-bars and is effected by vertical adjustment of a fulcrum bar 10, Figs. 1 and 7, carrying the rods 21, 58. The fulcrum bar 10 is carried by a pair of arms 11, and is raised or lowered by a hand lever 45 connected to an eccentric 43 pivoted in the bar 10 and which bears in a slot 42 in a cam-plate 40 mounted on a transverse frame bar 41. The bar 10 is moved upwardly to reduce the power of the stroke in the type-bars and downwardly to increase the power so that the rollers 22 are closer to the cam surfaces 23 on type-bar operating cranks 24. The pivots 12 for the arms 11 may also be adjusted since they are carried in supporting brackets 13 pivoted to the side frames at 14 and locked in position by set screws 16. This adjustment controls the relative positions of the eccentrics 35 and the power roll 8, which due to the approximate alignment of the pivots 12 and stub shafts 36, is unaffected by movement of the bar 10 about pivots 12 by the hand lever 45. In a modification, Fig. 12 (not shown), the toggle 56 is replaced by a roller engaging a plate depending from the fulcrum bar. In the embodiment shown in Fig. 7 the operation of a key-lever 116, through a pin 117, pivots a trip rocker 114 effect' ing an upward sliding movement to a trigger 111 having an arm 112 holding a catch 109 on a trip lever 106 which is thus freed to pivot anti-clockwise under the pull of a spring 102 connected to an eccentric slide 100 carrying an eccentric 103. The trip lever 106 pivots about a guide projection 107, working in a slot 108 formed in a power arm 95, and the eccentric is lowered into contact with the power roll 8, to be rotated until the wide portion of the eccentric is between the axis 105 and the power roller causing the trip lever 106 to be lowered in the slot 108 and the left-hand end of the power arm to be raised to transmit impression stroke to the crank 24. Further rotation of the eccentric to its initial position causes the slide 100 to move back to the right, raise trip lever 106, and allow the power arm 95 to return to its downward limit determined by a foot 98 contacting a plate 99. The plates 99 may be of various thickness in order to make individual adjustment to the amount of contact between the eccentric and the power roll for varying the impressional force to the type-bars or other type actions. In a still further modification the force to individual type-actions may be adjusted by movement of the actuating roller 137, Fig. 13, relative to an eccentric or cam 139. The power arm comprises two sections 131 and 130 pivoted together at 133 and adjusted by an eccentric clamping device 135, 136. Operation of the trigger 68 engages lug 153 on a trip lever 146 which turns clockwise about a pivot 147 on the section 130 so that a projection 148 engages a trip member 142 and pivots it to release a finger 141 holding the cam 139 against rotation by its engagement in a recess 140 formed in the eccentric. This movement breaks the toggle arrangement formed by parts 147, 152, 151 allowing a spring 28 to pull the power arms and cam 139 into contact with the power roll to effect an impressional action. Upon the completion of one revolution of the cam 139 the finger 141 re-engages the recess 140 and the toggle becoming straightened holds the cam free of the power roll 8. Ink-ribbon mechanism.-The ribbon vibrator 155, Fig. 2, is reciprocated from a lever 156 pivoting about a shaft 157 an amount determined by the position of a pin 178 in an inverted T-shaped slot 161 in a selector arm 160 fixed on one end of the shaft 157. The pin 178 is mounted on the end of a vibrator link 176 operated by a linkage 162, 164-6, from a universal bar 163 engaged by the cranks 24 and the pin 178 is moved into either end position in the horizontal portion of the slot 161 or into alignment with the vertical portion by a hand operated lever 174 and connection 175, 177 according to the amount of throw required or whether no movement of vibrator 155 is required as in the case when stencils are being cut. Sound-deadening.-A sound-deadening pad 89 is fitted on the key-lever comb-plate 88.