Browse Prior Art Database

Dual Pawl Escapement Mechanism

IP.com Disclosure Number: IPCOM000075601D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Barrett, MC: AUTHOR

Abstract

Incremental escapement is effected with the above mechanism which can be used, for example, in a track-stepping apparatus where there is to be reading or recording on every track on a magnetic card.

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Dual Pawl Escapement Mechanism

Incremental escapement is effected with the above mechanism which can be used, for example, in a track-stepping apparatus where there is to be reading or recording on every track on a magnetic card.

The advance of carrier or carriage 1 to the right is controlled by limit pawl 6 and escapement pawl 15 alternately engaging teeth 3 in escapement rack 2, when rockers 11 and 12 are rotated about pivot post 13 by magnet 4 and armature 5. A partial advance of carrier 1 from the normal position, shown in Fig. 1, to the position, shown in Fig. 2, takes place when magnet 4 is activated and rocker 11 is rotated by armature 5 acting on lug 7, which causes pawl 6 to engage the teeth on rack 2. Arm 9 of rocker 11 is also rotated a short distance before it contacts extension 14, and continued rotation causes pawl 15 to be disengaged from rack 2. This distance insures engagement of pawl 6 prior to disengagement of pawl 15. The Span of the bite of pawls 6 and 15 is such that when one is in abutting engagement with the vertical side of a tooth, the other will extend past the position of abutting engagement with another tooth. With pawl 15 disengaged from rack 2, carrier 1 will move to the right until pawl 6 abuts the vertical side of tooth 16 and pawl 15 extends past the point of abutting engagement with tooth 17. The remainder of the escapement cycle takes place when magnet 4 is deactivated, spring 10 rotates rocker 12 clockwise and pulls pawl 15 in...