Patent GB-372477-A (GB)
Title: Improvements in typewriting machines
IPC: B41J7/18
Filed: 1931-03-13
Abstract: 372,477. Typewriters. JAMES, R. W., 11, Queen Victoria Street, London.-(Reming- ton Typewriter Co. ; Ilion, New York, U.S.A.) March 13, 1931, No. 7824. [Class 100 (iv).] Type-lever machines.-In a noiseless action suitable for a portable machine and comprising a toggle connected to the type-lever and a weight or momentum-accumulator, the weight is so arranged that it normally tends to move the type-lever towards the platen, and may also be arranged to effect quick return and prevent rebound of the type-lever. The action may include means for ensuring uniform dip and touch of the keys and for preventing binding of the pivotal connections between parallel keylevers and radially arranged sub-levers. In the portable machine shown in the Figure, each type-lever 13 gears with a slide 18 and is connected to a toggle 70, 73, the slide being connected by a sub-lever or bell crank 22 and a link 32 to a key-lever 34, and the link 73 being connected to an arm 90 of a weight 80 which is connected to a link 86, the arm and link forming a toggle. The toggle 70, 73 breaks downwards after impression, the arrangement reducing the vertical dimension of the action. The typelevers are without lateral bends and lie in the same radial planes as the associated slides, bell cranks, and toggles. The links 73 are pivoted on a wire 75 in a segment 74 formed on a casting 2, and the type-levers and links 86 are pivoted on wires 14, 89 in segments 11, 12 formed in a casting 4 both castings being inclined at an angle of 8‹. The type-heads rest on a pad 15 on the segment 74. The slides 18 are guided by the segment 11 and rest on a plate 19 secured to the casting 4, and the bell cranks 22 are pivoted on hangers 24 mounted on a plate 25 secured to the framework. Each hanger is formed with a lug 62 and a hook 61 for insertion in a pair of apertures in the plate, the hanger being secured by twisting the lug. The lug may have cuts to facilitate twisting. A returning- spring 60 is arranged between each hanger and slide. Each bell crank has a lug 66 for limiting movement during assembly. The pivots 28 between the bell cranks and the links 32 are arranged in one straight row and directly over the associated key-levers. To prevent binding, the links are provided with swivels consisting of heads 33 formed on the links and resting on eyes 31 mounted on the pivots. The swivels are omitted from the two middle links. To permit independent movement of the links and keylevers, the links have hooks 32a or loops engaging the key-levers. The key-levers are parallel and are pivoted on a straight rod 35 arranged in a comb 42. The key-levers have keyhole slots 38 and are passed on to flats on the rod when in horizontal position, whereupon the rod is given a quarter turn, and is secured by a screw. The key-levers of the three lower banks have keys 36, and the key-levers of the top bank carry pivoted stems 54 which pass through a comb 56 and have keys 36. The machine is provided with forty-four of the above-described actions, each type-head having two types, and each type-lever being movable through an angle of 62‹, and the printing point being slightly above the horizontal diameter of the platen 37. On depression of any key-lever, the associated typelever is swung forwards and the weight is swung downwards and forwards, an easy start being effected by the leverage of the weight. When the type-head approaches the platen, the keylever is arrested by the pad 47, and the stroke of the type-lever is completed by momentum, the weight continuing to swing forwards until the toggles 70, 73 and 86, 90 are straightened. The type-lever is returned quickly by the spring 60, a resilient stop 91 for the links 86, and the gravity effect of the weight 80 and the toggle 70, 73. After the type-head engages the pad 15, the weight continues to move rearwards and thereby prevent rebound of the type-lever. A pad 93 in the segment 2 limits the movement of the weight to prevent the toggle 90, 86 from moving into the dead-straight position and thereby positively locking the type-lever. Specifications 189,324, [Class 100 (iv), Typewriters &c.], and 372,465 are referred to. Keys.-To provide uniform dip, the keylevers of the four banks are provided with graded stop faces 49 .. 52 for engaging a pad 47. To provide uniform touch, the arms 27 of the bell cranks 22 are of graded lengths, the longest arms being associated with the key-levers of the top bank. Letter-spacing mechanism.-A universal bail 96, pivoted at 98 to brackets 99 on the segment 4, is actuated by projections 94 on the typelevers 13. To compensate for the different distances between the type-levers and the pivots 98, the universal bail is normally tilted so that the projections approach more closely thereto from the sides to the middle of the machine.