Claims
- 1. In an electric typewriter having a frame and a carriage movable relative to said frame in carriage return, backspace, escapement and tabulating directions,
- an escapement rack mounted in said carriage controlled by an escapement pawl,
- a backspace actuator pivotally mounted on said frame,
- a backspace pawl mounted on said frame for pivotal movement in a forward direction about a first pivot extending through a first opening in said pawl from a rest position to engagement with said escapement rack and for limited lateral movement to drive said rack one tooth in response to actuator movement thereagainst,
- a spring connected between said pawl and frame for holding said pawl in rest position in contact with said backspace actuator,
- means on said pawl and frame including a second pivot extending through a second opening in said pawl for allowing reverse pivoting of said pawl about said second pivot to a disabled active position in response to carriage return movement initiated contemporaneously with backspace movement,
- and means for holding said pawl in said disabled active position until termination of carriage return movement or retraction of said backspace actuator.
- 2. In an electric typewriter having a frame and a carriage movable relative to said frame in carriage return, backspace, escapement and tabulating directions,
- an escapement rack mounted on said carriage,
- a backspace pawl actuator,
- a backspace pawl having one end positioned to be driven by said actuator,
- said pawl having a first horizontal run extending from said one end, an upward direction run, and a second horizontal run terminating in an upwardly directed rack engaging tooth,
- a first opening adjacent said one end having a vertical portion and a horizontal portion directed toward said toothed end,
- a second trapezoidal opening in said second horizontal run,
- first and second frame mounted pins extending into said first and second openings,
- and a spring connected at one end to said upward run and to said frame at a point vertically spaced from the point of connection to said upward run, thereby holding said one end of the pawl against said pawl actuator with said first pin located at the end of said horizontal portion and said second pin in the upper corner of said trapezoidal opening closest to said toothed end,
- and means for driving said pawl actuator whereby said pawl is pivoted upwardly about said first pin to engage the rack and is moved relative to said pins to the extent permitted by said horizontal portion of said first opening,
- said pawl being drivable out of engagement from the rack to a by-pass position by a carriage return movement initiated contemporaneously with actuation of said backspace pawl, said movement being accommodated by the vertical portion of said first opening,
- and means in said second opening for holding said pawl in by-pass position during carriage return or until said backspace actuator allows return of said pawl.
Parent Case Info
This is a division of application Ser. No. 333,389, filed Feb. 16, 1973, now U.S. Pat No. 3,876,054.
US Referenced Citations (6)
Divisions (1)
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Number |
Date |
Country |
Parent |
333389 |
Feb 1973 |
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