TYPEWRITER KEYBOARD WITH A KEYLEVER PAWL TUBE SPRING

摘要

A hollow tubular rubber or rubberlike deformable member is supported by a plurality of character keylevers in a typewriter keyboard and constrained against movement within the typewriter by supporting surfaces on the keylevers such that the tube engages the keylever pawls carried by the keylevers. As the keyboard of the typewriter operates, an interposer will force the keylever pawl rearward to provide complete restoration of the selection interposer. If the pawl did not rotate and the keylever is still in its depressed position upon the completion of the keyboard cycle, the selection logic would not be cleared and any following keylever input would result in a malselection. Also, interposer loading would prevent keylever restoration. The force of the interposer against the front edge of the keylever pawl will force the keylever pawl to pivot about its pivot stud and to locally compress the tube spring, formed out of a resilient pliable rubber-like material. Upon the restoration of the keylever to its rest position and withdrawal of the keylever pawl from engagement with the interposer stem, the forces generated within the tube spring during local deformation will be released and will act to restore the keylever pawl to its normal at rest position. The tube spring extends across the entire keyboard engaging all keylever pawls in the keyboard, thus eliminating the need for a separate spring or spring finger to be engaged with each keylever pawl and each keylever.