Patent ID: 8122791

Claim:
A three-way ratchet drive mechanism for a work tool which mechanism is settable, selectively, to a desired one of three modes of operation, namely, a first mode of operation where ratcheting operation is enabled in a clockwise direction, a second mode of operation where ratcheting operation is enabled in an anti-clockwise direction, or a third mode of operation where the drive mechanism is locked and ratcheting operation is disabled, said mechanism comprising: (a) a ratchet housing ( 5 ), said housing including a guide tube ( 8 ) formed in the housing; (b) a drive shaft ( 20 ) extending longitudinally from a proximal end ( 21 ) of a first end portion ( 22 ) of the shaft to a distal end ( 29 ) of a second end portion ( 28 ) of the shaft, said first end portion extending into said guide tube, said guide tube being sized for providing lateral bearing support to said first end portion; (c) a ratchet wheel ( 40 ) coaxially fitted within the housing to the first end portion of the shaft in a position above the guide tube; (d) a pawl spring ( 90 , 190 , 290 ) retained within said housing, said spring having first ( 91 , 191 , 291 ) and second ( 92 , 192 , 292 ) spring arms; (e) opposed first ( 60 a ) and second ( 60 b ) J-shaped ratchet pawls mounted within the housing, each pawl being biased by an associated one of said spring arms substantially linearly towards a position of engagement with the ratchet wheel such that: if both pawls are in positions of engagement with the ratchet wheel, then ratcheting operation is disabled; else, if only the first pawl ( 60 a ) is in a position of engagement with the ratchet wheel, then ratcheting operation is enabled in a first rotational direction; else, if only the second pawl ( 60 b ) is in a position of engagement with the ratchet wheel, then operation is enabled in a second rotational direction opposite to the first direction; (f) a retaining clip ( 70 , 270 ) for holding said pawl spring in a position where the spring arms bear against said pawls urging the pawls substantially linearly towards said ratchet wheel; (g) a selector sleeve ( 50 ) coaxially fitted from over the top of the housing for rotational movement relative to the housing in directions corresponding to said first and second rotational directions, said sleeve including first ( 52 ) and second ( 53 ) tabs projecting into the housing, said first tab ( 52 ) being positioned to engage and forcibly push said first pawl ( 60 a ) substantially linearly away from engagement with said ratchet wheel when the sleeve is rotated against the bias of said first spring arm; said second tab ( 53 ) being positioned to engage and forcibly push said second pawl ( 60 b ) substantially linearly away from engagement with said ratchet wheel when the sleeve is rotated against the bias of said second spring arm; and, (h) selector sleeve retaining means for retaining the selector sleeve in a rotational position relative to the housing which corresponds to a desired one of said three modes of operation.