Browse Prior Art Database

Ratchet Drive Mechanism

IP.com Disclosure Number: IPCOM000095317D
Original Publication Date: 1965-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Holt, GA: AUTHOR

Abstract

The mechanism incrementally drives ratchet 10 in the direction of arrow 30. The mechanism can be employed for providing backspacing movements in a power driven business machine, such as an electric typewriter.

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Ratchet Drive Mechanism

The mechanism incrementally drives ratchet 10 in the direction of arrow 30. The mechanism can be employed for providing backspacing movements in a power driven business machine, such as an electric typewriter.

To begin an operational cycle, cam 11 rotates and follower 13 pivots to move link 14 down. This causes lever 15 to rock clockwise and pull link 16. The initial motion of link 16 rotates pawl 17 about pivot 18 without moving arm 19 since the arm is engaged by friction pad 22 at this time. Arm 19 is pivotally mounted from a stationary bracket 23. When pawl 17 bottoms in the tooth of ratchet 10, pawl 17, arm 19 and ratchet 10 are locked together by the pulling force on link 16 and act as a unit. Cam 11 rotates to its high point and ratchet 10 is advanced in the direction of arrow 30. The distance is slightly greater than the distance occupied by one tooth on ratchet 10. The latter is held in its advanced position by a pawl not shown. Thus, the drive linkage can be returned to its initial condition without altering the rotary position of ratchet 10.

As cam 11 rotates past its high point, spring 20 reverses the system and causes link 16 to move down. Link 16 now rotates pawl 17 counterclockwise about pivot 18 until extension 21 of pawl 17 contacts arm 19. Friction pad 22 holds arm 19 stationary until it is engaged by extension 21. Then arm 19 and pawl 17 are locked together and act as a unit during the return stroke. At the end of the ret...