Line indicator for typewriter platens

Abstract

Abstract A TYPEWRITER PLATEN HAS A CARD INDICATOR CONNECTED THERETO WHICH INCLUDES A DETENT RING HAVING A SINGLE DETENT NOTCH IN ITS PERIPHERY WHICH IS SENSED DURING PLATEN ROTATION BY A DETENT ROLLER MOUNTED ON THE CARRIAGE. THE DETENT RING, FOR THE PURPOSE OF RELATIVE ROTATIONAL ADJUSTMENT OF THE DETENT RING AND CARD CLAMP, IS MADE ROTATABLE INDEPENDENTLY OF THE PLATEN BY MOUNTING IT ON THE LINE SPACING RATCHET FOR ROTATION WITH THE LATTER. RELEASE OF A LINE SPACING RATCHET CLUTCH PERMITS THE ROTATION OF THE PLATEN WITHOUT AFFECTING THE LINE SPACING RATCHET AND THE DETENT RING, ALLOWING THE NOTCH IN THE LATTER TO BE FIRST ROTATED INTO DETENTED POSITION AS THE PLATEN IS TORATED AND THE SUBQUENT ROTATION OF THE PLATEN AND CARD CLAMPING BAR ALONE TO A DESIRED LINE POSITION. WHENEVER, THEREAFTER, THE DETENT ROLLER ENTERS THE DETENT NOTCH, IT WILL BE AN INDICATION TO THE OPERATOR THAT A PREDETERMINED LINE OF CARD HELD BY THE CARD CLAMP IS IN PROPER TYPING POSITION. THE ADDITIONAL TORQUE PROVIDED BY REGISTRATION OF THE DETENT AND DETENT NOTCH, WHILE PRODUCING A CLEAR SIGNAL THAT A DESIRED LINE POSITION HAS BEEN REACHED, IS NOT SUFFICIENT TO INTERFERE WITH SUBSEQUENT CONVENTIONAL LINE FEED FUNCTIONS. THE DETENT ROLLER IS MOUNTED ON A PIVOTED, SPRING-BIASED BELLCRANK CARRIED BY THE CARRIAGE. A LATCH FINGER AT ONE END OF THE BELLCRANK CAN BE SWUNG INTO CONTACT WITH THE CARRIAGE FRAME TO DISABLE THE DETENT ROLLER.

Inventors

• 👤 Hugh St Lawrence Dannatt

Bibliographic Details