Two Mode Ratchet
Original Publication Date: 1967-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Barna, TB: AUTHOR [+2]
AbstractOutput shaft 5 carries a pair of oppositely-directed ratchet wheels 7 and 8. Pawl carriers 2 and 12 are mounted to rotate about 5. Input gear 1 is connected to 2 so that an input drive sector, not shown, oscillates 2 to rotate 5 as follows.
Two Mode Ratchet
Output shaft 5 carries a pair of oppositely-directed ratchet wheels 7 and 8. Pawl carriers 2 and 12 are mounted to rotate about 5. Input gear 1 is connected to 2 so that an input drive sector, not shown, oscillates 2 to rotate 5 as follows.
When 2 is oscillated through a small arc, angle A or less, drive pawl 6 mounted on 2 coacts with 7 in the conventional manner to step 5 through unidirectional clockwise increments. Carrier 12 remains stationary under the influence of detent 1 1 which engage s notch 15. Pawl 9 mounted on 12 pe rforms an antireve rse function on 7. Pawl 10, also mounted on 12, is held out of engagement with 8 by 1 1.
When 2 is driven first clockwise and then counterclockwise through a long arc greater than A, 5 is driven clockwise the full extent of the arc during the clockwise movement of 2 and is driven X - A, X equals the full arc, counterclockwise during the counterclockwise return movement of 2. This is accomplished as follows.
During the clockwise rotation of 2, 6 engages 7 to drive 5 through the full clockwise arc. After the first A degrees of this movement, shoulder 4 on 2 engages pin 13, mounted on 12, causing 12 to then rotate with 2. When 1 2 begins rotation, 15 is pulled out of engagement with 11 and 10 is spring-biased into contact with 8. After the remaining portion of the clockwise arc is completed and as 2 begins to rotate in the return direction, 12 is held stationary by the frictional contact of 1 1 with the pe...