Transmission control

Claim 2

In a transmission control the combination of engine driven fluid pump means; main pressure passage means connected to receive fluid from said fluid pump means; a plurality of fluid delivery passage means including first and second delivery passage means for delivering fluid to establish forward and reverse transmission drives with said first delivery passage means delivering fluid for establishment of all forward drives and said second delivery passage means delivering fluid for establishment of reverse drive; manual selector valve means operable in a plurality of forward drive positions to connect said main pressure passage means to said first delivery passage means, also operable in a reverse drive position to connect said main pressure passage means to said second delivery passage means and also operable in at least one no-drive position to block said main pressure passage means from both said first and second delivery passage means while exhausting said first and second delivery passage means; and interlock valve means operable in a lock position to prevent fluid delivery through both said first and second delivery passage means and also operable in an unlock position to open both said first and said second delivery passage means, said interlock valve means comprising spring means normally holding said interlock valve means in said lock position, first pressure responsive means continuously responsive to the pressure in said main pressure passage means to provide a first pressure bias biasing said interlock valve means to said unlock position, signal passage means, check valve means for alternatively connecting said first and second delivery passage means to said signal passage means, second pressure responsive means operatively connected to said signal passage means only in said lock position for providing a second pressure bias balancing said first pressure bias only in said lock position when fluid is being delivered by said manual selector valve means to either said first or second delivery passage means whereby said interlock valve means is moved by said first pressure bias against the bias of said spring means to said unlock position when said manual selector valve means is in said no-drive position on initial fluid delivery by said fluid pump means and remains held by said first pressure bias in said unlock position when said manual selector valve means is thereafter moved to any of said drive positions and alternatively, said interlock valve means is held in said lock position by the bias of said spring means and said second pressure bias against said first pressure bias when said manual selector valve means is in any one of said drive positions on initial fluid supply by said fluid pump means and said interlock valve means is thereafter moved to said unlock position by said first pressure bias against the bias of said spring means when said second pressure bias is relieved by said manual selector valve means being moved to said no-drive position.

Claim 3

The transmission set forth in claim 1 and said interlock valve means including means providing the connection between said signal passage means and said second pressure responsive means in said lock position and disconnecting said second pressure responsive means from said signal passage means in said unlock position.

Claim 4

In a transmission control the combination of engine driven fluid pump means; main pressure passage means connected to receive fluid from said fluid pump means; a plurality of fluid delivery passage means including first and second delivery passage means for delivering fluid to establish forward and reverse transmission drives with said first delivery passage means delivering fluid for establishment of all forward drives and said second delivery passage means delivering fluid for establishment of reverse drive; manual selector valve means operable in a plurality of forward drive positions including a drive range position, an intermediate range position and a low range position to connect said main pressure passage means to said first delivery passage means, also operable in a reverse drive position to connect said main pressure passage means to said second delivery passage means and also operable in both a neutral position and a park position to block said main pressure passage means from both said first and second delivery passage means while exhausting said first and second delivery passage means; and interlock valve means operable in a lock position to prevent fluid delivery through both said first and second delivery passage means and also operable in an unlock position to open both said first and second delivery passage means, said interlock valve means comprising spring means normally holding said interlock valve means in said lock position, first pressure responsive means continuously responsive to the pressure in said main pressure passage means to provide a first pressure bias biasing said interlock valve means to said unlock position, signal passage means, check valve means for alternatively connecting said first and second delivery passage means to said signal passage means, second pressure responsive means operatively connected to said signal passage means only in said lock position for providing a second pressure bias balancing said first pressure bias only in said lock position when fluid is being delivered by said manual selector valve means to either said first or second delivery passage means whereby said interlock valve means is moved by said first pressure bias against the bias of said spring means to said unlock position when said manual selector valve means is in either its neutral or park position on initial fluid delivery by said fluid pump means and remains held by said first pressure bias in said unlock position when said manual selector valve means is thereafter moved to any of said drive positions and alternatively, said interlock valve means is held in said lock position by the bias of said spring means and said second pressure bias against said first pressure bias when said manual selector valve means is in any one of said drive positions on initial fluid supply by said fluid pump means and said interlock valve means is thereafter moved to said unlock position by said first pressure bias against the bias of said spring means when said second pressure bias is relieved by said manual selector valve means being moved to either said neutral or park position.

Claim 5

In a transmission control the combination of engine driven fluid pump means; main pressure passage means connected to receive fluid from said fluid pump means; a plurality of fluid delivery passage means including first and second delivery passage means for delivering fluid to establish forward and reverse transmission drives with said first delivery passage means delivering fluid for establishment of all forward drives and said second delivery passage means delivering fluid for establishment of reverse drive; manual selector valve means operable in a plurality of forward drive positions including a drive range position, an intermediate range position and a low range position to connect said main pressure passage means to said first delivery passage means, also operable in a reverse drive position to connect said main pressure passage means to said second delivery passage means and also operable in both a neutral position and a park position to block said main pressure passage means from both said first and second delivery passage means while exhausting said first and second delivery passage means; and interlock valve means operable in a lock position to prevent fluid delivery through both said first and second delivery passage means and also operable in an unlock position to open both said first and second delivery passage means, said interlock valve means comprising spring means normally holding said interlock valve means in said lock position, first pressure responsive means continuously responsive to the pressure in said main pressure passage means to provide a first pressure bias biasing said interlock valve means to said unlock position, signal passage means, check valve means for alternatively connecting said first and second delivery passage means to said signal passage means, second pressure responsive means operatively connected to said signal passage means only in said lock position for providing a second pressure bias balancing said first pressure bias only in said lock position when fluid is being delivered by said manual selector valve means to either said first or second delivery passage means whereby said interlock valve means is moved by said first pressure bias against the bias of said spring means to said unlock position when said manual selector valve means is in either its neutral or park position on initial fluid delivery by said fluid pump means and remains held by said first pressure bias in said unlock position when said manual selector valve means is thereafter moved to any of said drive positions and alternatively, said interlock valve means is held in said lock position by the bias of said spring means and said second pressure bias against said first pressure bias when said manual selector valve means is in any one of said drive positions on initial fluid supply by said fluid pump means and said interlock valve means is thereafter moved to said unlock position by said first pressure bias against the bias of said spring means when said second pressure bias is relieved by said manual selector valve means being moved to either said neutral or park position.