Shift control mechanism

Claim 2

A shift control mechanism for a synchromesh transmission, said control mechanism comprising a pair of shift forks, an extension shaft formed on each of said shift forks, the axis of each of said extension shafts being movable in a lateral path for correspondingly moving said shift forks to select the desired speed ratios within said transmission, a single shaft rotatably mounted through a wall of said transmission, a first plate member having teeth formed on a portion of the outer periphery thereof and being secured to the interior end of said single shaft, a rack member having teeth formed thereon for at times meshing with said teeth of said first plate member, a manually-actuable cable connected to said rack member for causing reciprocal movement thereof, A pivotable member secured to said interior end of said single shaft, a pair of contoured cam grooves formed in said pivotable member, each of said contoured cam grooves having portions thereof formed along arcs of a circle about the axis of said single shaft with other portions thereof being radially inward and radially outward of said circle, said extension shafts being slidably mounted in said contoured cam grooves such that said extension shafts are caused to laterally move one of said shift forks into a neutral position while moving the other of said shift forks into some one of first, second, third, or fourth speed ratio positions in response to pivotal movement of said shift lever and said single shaft by said cable, additional teeth formed on a side of said rack member, a second plate member having teeth formed on a portion of the outer periphery thereof for meshing with said additional teeth on said rack member when said teeth on said first plate member are out of mesh with said first-mentioned teeth of said rack member, a reverse speed ratio positioning shaft, and linkage means operatively connected to said second plate member for rotating said reverse speed ratio positioning shaft in response to manual movement of said cable.

Claim 3

A shift control mechanism for a synchromesh transmission, said control mechanism comprising a pair of shift forks, an extension shaft formed on each of said shift forks, the axis of each of said extension shafts being movable in a lateral path for correspondingly moving said shift forks to select the desired speed ratios within said transmission, a single shaft rotatably mounted through a wall of said transmission, a plate member having teeth formed on a portion of the outer periphery thereof and being secured to the interior end of said single shaft, a rack member having teeth formed thereon for at times meshing with said teeth of said plate member, a manually-actuable cable connected to said rack member for causing reciprocal movement thereof, a pivotable member secured to said interior end of said single shaft, a generally circular contoured cam groove formed in said pivotable member, said generally circular contoured cam groove having portions thereof formed along arcs of a circle about the axis of said single shaft with other portions thereof being radially inward and radially outward of said circle, said extension shafts being slidably mounted in said contoured cam groove such that said extension shafts are caused to laterally move one of said shift forks into a neutral position while moving the other of said shift forks into some one of first, second, third, or fourth speed ratio positions in response to pivotal movement of said shift lever and said single shaft by said cable, a guide slot formed in a wall of said transmission, a shaft member having one end thereof mounted in said guide slot, a cam slot formed adjacent the outer periphery of said pivotable member and positioned so as to contact said shaft member, a reverse speed ratio positioning lever, and linkage means operatively connected between said shaft member and said reverse speed ratio positioning lever, said shaft member being movable in said guide slot by said pivotable member in response to manual actuation of said cable for moving said linkage means to rotate said reverse speed ratio positioning lever.

Claim 4

A shift control mechanism for a synchromesh transmission, said control mechanism comprising a pair of shift forks, an extension shaft formed on each of said shift forks, the axis of each of said extension shafts being movable in a lateral path for correspondingly moving said shift forks to select the desired speed ratios within said transmission, a single shaft rotatably mounted through a wall of said transmission, a plate member having teeth formed on a portion of the outer periphery thereof and being secured to the interior end of said single shaft, a rack member having teeth formed thereon for at times meshing with said teeth of said plate member, a manually-actuable cable connected to said rack member for causing reciprocal movement thereof, a pivotable member secured to said interior end of said single shaft, a generally circular contoured cam groove formed in said pivotable member, said generally circular contoured cam groove having portions thereof formed along arcs of a circle about the axis of said single shaft with other portions thereof being radially inward and radially outward of said circle, said extension shafts being slidably mounted in said contoured cam groove such that said extension shafts are caused to laterally move one of said shift forks into a neutral position while moving the other of said shift forks into some one of first, second, third, or fourth speed ratio positions in response to pivotal movement of said shift lever and said single shaft by said cable, a guide slot formed in a wall of said transmission, a shaft member having one end thereof mounted in said guide slot, a cam slot formed adjacent the outer periphery of said pivotable member and positioned so as to contact said shaft member, a reverse speed ratio positioning lever, and linkage means operatively connected between said shaft member and said reverse speed ratio positioning lever, said shaft member being movable in said guide slot by said pivotable member in response to manual actuation of said cable for moving said linkage means to rotate said reverse speed ratio positioning lever.

Claim 5

A shift control mechanism for a synchromesh transmission, said shift control mechanism comprising a housing, a reverse-first and a second-third shift fork located in said housing, a shaft pivotally mounted through a wall of said housing, a shift lever mounted on the exposed end of said shaft, a manually-actuable cable pivotally connected to said shift lever for causing pivotal movement thereof, a pivotable flat plate member secured to the interior end of said shaft in a parallel relationship with said wall of said housing, a pair of contoured cam grooves formed in said pivotable flat plate member, a shaft-like extension formed on each of said shift forks and extending through said respective cam grooves and adapted to having levers pivotally mounted on the extended ends thereof, first and second levers each pivotally mounted at one end thereof on said wall of said housing intermediate said wall of said housing and said flat plate member and pivotally mounted at the other ends thereof on said respective extended ends of said shaft-like extensions for operatively cooperating with said contoured cam grooves in response to reciprocal pivotal movements of said shift lever and said shaft by said manually-actuable cable to cause said shaft-like extensions to concurrently move through respective arcuate paths about said one end of each of said respective first and second levers for selectively moving said second-third shift fork into a neutral position while moving said reverse-first shift fork into one of reverse and first speed ratio positions and alternately moving said reverse-first shift fork into a neutral position while moving said second-third shift fork into one of second and third speed ratio positions, and fastener means secured to each of said shaft-like extensions adjacent each side of each of said first and second levers for axially locating said shaft-like extensions.

Claim 6

A shift control mechanism for a synchromesh transmission, said shift control mechanism comprising a housing, a reverse-first and a second-third shift fork located in said housing, a shaft pivotally mounted through a wall of said housing, a shift lever mounted on the exposed end of said shaft, a manually-actuable cable pivotally connected to said shift lever for causing pivotal movement thereof, a pivotable flat plate member secured to the interior end of said shaft in a parallel relationship with said wall of said housing, a pair of contoured cam grooves formed in said pivotable flat plate member, a shaft-like extension formed on each of said shift forks and extending through said respective cam grooves and adapted to having levers pivotally mounted on the extended ends thereof, first and second levers each pivotally mounted at one end thereof on said wall of said housing intermediate said wall of said housing and said flat plate member and pivotally mounted at the other ends thereof on said respective extended ends of said shaft-like extensions for operatively cooperating with said contoured cam grooves in response to reciprocal pivotal movements of said shift lever and said shaft by said manually-actuable cable to cause said shaft-like extensions to concurrently move through respective arcuate paths about said one end of each of said respective first and second levers for selectively moving said second-third shift fork into a neutral position while moving said reverse-first shift fork into one of reverse and first speed ratio positions and alternately moving said reverse-first shift fork into a neutral position while moving said second-third shift fork into one of second and third speed ratio positions, and fastener means secured to each of said shaft-like extensions adjacent each side of each of said first and second levers for axially locating said shaft-like extensions.