| 摘要 |
1,226,637. Key mechanism. SPERRY RAND CORP. 19 Dec., 1968 [20 Dec., 1967], No. 60395/68. Heading G4B. A pivotally mounted operating bar of a tenkey calculator, similar to that described in Specification 1,172,702, selectively moves an articulated lever 60 having an inclined ramp 60a so that the ramp laterally shifts a member 80 to align a cam follower 61 with a selected track of a multiple track cam (12), Fig. 1 (not shown). As described the operating bar (26) has a stem which engages a slot 101 in a pivotally mounted lever 102 biased by a spring 103 into a neutral position and articulated at 107 to the lever 60. For total and sub-total taking an abutment 20a on the pin carriage which is cleared to its extreme right position forces the lever 60 against a stop 60b. Depression of the lower portion of the bar (26) (sub-total) drives the lever 60 forward so that the ramp 60a displaces the member 80 to the right aligning the follower 61 with the extreme right hand track of the cam (12). Depression of the upper portion of the bar (26) withdraws the ramp and allows the follower 61 to move one track to the left on the cam (12). For addition and subtraction the pin carriage is displaced to the left and the lever 60 is moved away from the stop 60b by the action of a spring 81. Withdrawal of the ramp 60a by depression of the upper portion of the key (26) (addition) causes the follower 61 to shift to the extreme left hand track of the cam (12), while depression of the lower (sub-traction) portion of the bar (26) drives the ramp 60a forwards the shift the follower 61 one space to the right. |
