Improvements in Platen Shifting Mechanism for Typewriting Machines.

摘要

13,167. Ronchetti, J. A. June 5, 1908, [Convention date]. Paper-carriages; carriage-shift mechanism; shiftkey actions; key-locks.-Relates to platen-shift mechanism of the kind described in Specification 17,867/07, wherein the shift-key levers operate a floating lever which is connected to the papercarriage. The platen-frame 5, Fig. 2, is provided with rails 10, 11 supported by balls on a rail 12 carried by pivoted arms 13. The rail 12 is connected by a rod 18 to a lever 25, Fig. 1, the rod being provided at the ends with balls 17, 22 mounted in socketplates 20, 26, which may be adjusted by screws 21, 27. The lever 25 is pivoted to the framework by means of a ball 30 and is also pivoted to a floating lever 32, which consists of bars 33, 34 connected by a cross-bar 35 provided with a ball 31, which is mounted in-a socket-plate in the lever 25. The bars 33, 34 are arranged outside the shift-key levers 37, 41 which are pivoted at 38, 44, Fig. 2, to the framework. The floating lever is pivoted at 36 to the key-lever 37 and is connected to the keylever 41 by means of slots 43 which engage a pin 42 on the key-lever. The key-lever 41 is locked in the normal position by a spring 63, which engages beneath a lug 65 on the keylever. A key 51 pivoted at 53 to the key-lever 41 is formed with a finger 67, which engages the spring 63 so that, when the key is depressed, it first swings about its pivot and releases the spring 63 from the lug 65, further pressure on the key then swinging the key - lever about its pivot 44. The pivotal movement of the key 51 is limited by a lug 57 which engages shoulders 55 on the key. The key-lever 37 is locked by a second spring 63 and lug 65, and is provided with a key 50 of the same construction as the key 51. The devices operate in the manner described in the above-mentioned Specification, a depression of either of the keys 50,51 first releasing the spring 63 to permit free depression of the keylever, the other key-lever remaining locked in the raised position and serving as a pivot support for the floating lever 32, which is swung by the depressed key-lever and raises or depresses the platen according as to which key is operated. The swing of the lever 25 is limited as in the above-mentioned Specification by toggle-links 70, 72, 77, 78, Fig. 3, which normally are held flexed by springs 84, 85. The link 70 is pivoted to the lever 25, and the link 72 is pivoted to an eccentric 74, which is clamped in adjusted position by a screw 75. The link 77 is similarly pivoted to the lever 25, and the link 78 is pivoted to an adjustable eccentric 82. When the lever 75 is swung up or down by the floating lever 32, one of the pairs of links 70, 72 and 77, 78 is strengthened and the swinging lever 25 and the connected parts are arrested without concussion and silently. The platen-frame is balanced by an elliptical spring 88, which is arranged beneath the lever 25 and is attached to an extension of the iod 18, the spring being adjusted by means of a screwstud 91. The platen is further balanced by a spring 47 attached to a clip 45, which is secured to the floating lever 32 by a slot adjustment 46. The spring 47 pulls the floating lever 32 upwards and holds the key-levers 41, 37 in engagement with a cushion-stop 48.