Gear shifting assembly for change-speed transmissions

Claim 2

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members, said cylinder means being provided with two fluid-admitting pressure ports located at the opposite sides of said piston means and with a plurality of fluiddischarging ports located in the path of movement of said piston means; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means including a directional control valve interposed between said pressure ports and said source and arranged to admit pressurized fluid to the pressure port at the higher-pressure side of said first piston means, and normally closed electromagnetic shutoff valves for said discharging ports whereby said first piston means automatically moves to a position in which it seals that discharging port which was free to discharge fluid from said first cylinder means in response to opening of the respective shutoff valve.

Claim 3

An assembly as defined in claim 1, wherein said first and second piston means are respectively movable in first and second planes which are at least substantially normal to each other.

Claim 4

An assembly as defined in claim 2, wherein each of said piston means comprises at least one double-acting piston and said second piston means is movable between two operative positions, said neutral position being located between said operative positions.

Claim 5

An assembly as defined in claim 1, wherein said valve means further comprises a normally closed solenoid operated safety valve interposed between said source and said directional control valve.

Claim 6

An assembly as defined in claim 1, wherein said first piston means is reciprocable between said positions and comprises rotary and reciprocable piston rod means extending beyond said first cylinder means, said shifting members being rotatable about the axis of said piston rod means and having aligned openings therefor, said displacing means being provided on said piston rod means and being received in the opening of the selected shifting member in the corresponding position of said first piston means whereby said displacing means can transmit torque to the selected shifting member, said second piston means being arranged to rotate said piston rod means in response to movement relative to said second cylinder means.

Claim 7

An assembly as defined in claim 5, wherein said second piston means comprises second piston rod means extending beyond and reciprocable relative to said second cylinder means, and further comprising means for rotating the piston rod means of said first piston means in response to lengthwise movement of said second piston rod means.

Claim 8

An assembly as defined in claim 6, wherein said means for rotating comprises a lever rotatable with and movable axially of said first mentioned piston rod means, said second piston rod means having a recess receiving a portion of said lever to pivot the latter and to thereby turn said first mentioned piston rod means in response to axial movement of said second piston means relative to said second cylinder means.

Claim 9

An assembly as defined in claim 7, wherein said piston rod means are normal to and cross in space with each other, said portion of said lever being of at least substantially spherical shape.

Claim 10

An assembly as defined in claim 7, wherein said first mentioned piston rod means comprises a splined shaft which is movable axially relative to and receives torque from said lever.

Claim 11

An asseMbly as defined in claim 1, wherein said displacing means is rotatable into register with selected shifting members in response to axial movement of said first piston means relative to said first cylinder means, said second piston means being arranged to move said displacing means axially and to thereby actuate the selected shifting member in response to movement of said second piston means relative to said second cylinder means.

Claim 12

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members, said piston means comprising piston rod means having an elongated toothed rack and said displacing means comprising a gear meshing with said rack, said displacing means being rotatable into register with selected shifting members in response to axial movement of said piston means relative to said cylinder means; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second piston means being arranged to move said displacing means axially and to thereby actuate the selected shifting member in response to movement of said second piston means relative to said second cylinder means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 13

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members, said piston means comprising piston rod means having an elongated toothed rack and said displacing means comprising a gear meshing with said rack, said displacing means being rotatable into register with selected shifting members in response to axial movement of said piston means relative to said cylinder means; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second piston means being arranged to move said displacing means axially and to thereby actuate the selected shifting member in response to movement of said second piston means relative to said second cylinder means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 14

An assembly as defined in claim 11, wherein said second piston means is movable axially relative to said second cylinder means and at right angles to the axis of said first mentioned piston rod means, said gear being secured to said second piston rod means so that the latter rotates in response to axial movement of said rack and moves axially with said second piston means.

Claim 15

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising two fluid-admitting pressure ports at the opposite sides of said second piston means and a plurality of fluid-discharging ports located in the path of movement of said second piston means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means including a directional control valve interposed between said pressure ports and said source and arranged to admit pressurized fluid to the pressure port at the higher-pressure side of said second piston means, and normally closed shutoff valves for said discharging ports whereby said piston means automatically moves to a position in which it seals that discharging port which is free to discharge fluid from said second cylinder means in response to opening of the respective shutoff valve.

Claim 16

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising two fluid-admitting pressure ports at the opposite sides of said second piston means and a plurality of fluid-discharging ports located in the path of movement of said second piston means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means including a directional control valve interposed between said pressure ports and said source and arranged to admit pressurized fluid to the pressure port at the higher-pressure side of said second piston means, and normally closed shutoff valves for said discharging ports whereby said piston means automatically moves to a position in which it seals that discharging port which is free to discharge fluid from said second cylinder means in response to opening of the respective shutoff valve.

Claim 17

An assembly as defined in claim 13, wherein said second piston means is movable between two operative positions located at the opposite sides of said neutral position thereof, said discharging ports including a first port which is sealed by said second piston means in said neutral position thereof and two additional ports which are respectively sealed by said second piston means in the one and the other operative position thereof.

Claim 18

An assembly as defined in claim 13, wherein said shutoff valves are solenoid-operated valves.

Claim 19

An assembly as defined in claim 13, wherein each of said shutoff valves comprises a normally closed check valve and a solenoid-operated pilot valve which is energizable to thereby open the respective check valve.

Claim 20

An assembly as defined in claim 16, wherein each of said check valves comprises a substantially spherical valve element which normally dwells in a sealing position and a plunger which is movable axially in response to energization of the respective pilot valve to thereby move said valve element from said sealing position.

Claim 21

An assembly as defined in claim 17, wherein each of said check valves further comprises a body which defines a seat for said valve element and includes a portion which guides said plunger for axial movement, one end of said plunger being subjected to fluid pressure in response to energization of the respective pilot valve, said body further having an inlet in communication with the respective discharging port and an outlet, said inlet and outlet being located at the opposite sides of said seat so as to be sealed from each other in the sealing position of said valve element and each of said check valves further comprising means for biasing said valve element against the respective seat.

Claim 22

An assembly as defined in claim 13, wherein said valve means further comprises a normally closed solenoid-operated safety valve interposed between said source and said directional control valve.

Claim 23

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to two operative positions to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising a substantially centrally located abutment, two stops located at the opposite sides of and axially spaced from said abutment, a pair of fluid-admitting pressure ports each adjacent to one of said stops and a fluid-discharging port in the region of said abutment, said second piston means comprising a centrally located collar having a diameter smaller than the internal diameter of said abutment and a pair of smaller-diameter cylindrical portions flanking said collar, said collar being in register with said abutment in said neutral position of said second piston means and said actuating motor further comprising a pair of rings each surrounding and slidable on one of smaller-diameter portions, said collar being arranged to maintain one of said rings in sealing engagement with one of said pressure ports in one of said operative positions of said second piston means and said collar being arranged to maintain the other of said rings in sealing engagement with the other pressure port in the other of said operative positions of said second piston means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by Said source to and from said cylinder means.

Claim 24

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to two operative positions to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising a substantially centrally located abutment, two stops located at the opposite sides of and axially spaced from said abutment, a pair of fluid-admitting pressure ports each adjacent to one of said stops and a fluid-discharging port in the region of said abutment, said second piston means comprising a centrally located collar having a diameter smaller than the internal diameter of said abutment and a pair of smaller-diameter cylindrical portions flanking said collar, said collar being in register with said abutment in said neutral position of said second piston means and said actuating motor further comprising a pair of rings each surrounding and slidable on one of smaller-diameter portions, said collar being arranged to maintain one of said rings in sealing engagement with one of said pressure ports in one of said operative positions of said second piston means and said collar being arranged to maintain the other of said rings in sealing engagement with the other pressure port in the other of said operative positions of said second piston means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by Said source to and from said cylinder means.

Claim 25

An assembly as defined in claim 20, wherein said second piston means comprises a piston rod which extends beyond said second cylinder means and rotatably supports said displacing means, said displacing means being arranged to share the axial movements of said second piston means.

Claim 26

An assembly as defined in claim 20, wherein the axial length of said abutment equals the axial length of said collar and the distance between said abutment and either one of said stops equals the axial length of one of said smaller-diameter portions, the axial length of each of said rings being less than said distance and said rings having external surfaces in sealing engagement with the adjacent portions of the internal surface of said second cylinder means, said pressure ports being outwardly adjacent to the respective rings.

Claim 27

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members, a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to first and second operative positions to thereby actuate the selected shifting member by way of said displacing means, said second piston means comprising a piston rod extending axially through and beyond one end of said second cylinder means, a cylindrical extension extending toward the other end of said second cylinder means and a peripheral surface in sealing engagement with the internal surface of said second cylinder means, said actuating motor means further comprising a ring sealingly surrounding said extension and sealingly engaging the internal surface of an annular recess of said second cylinder means, the axial length of said recess being equal to that of said extension and said second cylinder means having a first fluid-admitting pressure port adjacent to said other end thereof, a second fluid-admitting pressure port adjacent to said one end thereof, and a fluid-discharging port adjacent to that axial end of said recess which is remote from said other end of said second cylinder means, said second piston means being arranged to seal said discharging port in said neutral position thereof and being movable from said neutral position to said first and second operative positions thereof in response to admission of pressurized fluid by way of said first and second pressure port, respectively; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 28

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members, a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to first and second operative positions to thereby actuate the selected shifting member by way of said displacing means, said second piston means comprising a piston rod extending axially through and beyond one end of said second cylinder means, a cylindrical extension extending toward the other end of said second cylinder means and a peripheral surface in sealing engagement with the internal surface of said second cylinder means, said actuating motor means further comprising a ring sealingly surrounding said extension and sealingly engaging the internal surface of an annular recess of said second cylinder means, the axial length of said recess being equal to that of said extension and said second cylinder means having a first fluid-admitting pressure port adjacent to said other end thereof, a second fluid-admitting pressure port adjacent to said one end thereof, and a fluid-discharging port adjacent to that axial end of said recess which is remote from said other end of said second cylinder means, said second piston means being arranged to seal said discharging port in said neutral position thereof and being movable from said neutral position to said first and second operative positions thereof in response to admission of pressurized fluid by way of said first and second pressure port, respectively; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 29

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising discrete coaxial first and second cylinders and said second piston means constituting a twin piston having first and second stages respectively reciprocable in said first and second cylinders, each of said cylinders having an inner end nearer to and an outer end remote from the other cylinder and each of said stages having a collar located in the respective cylinder and remote from the respective inner end, said actuating motor means further comprising first and second rings sealingly surrounding and slidable on said first and second stages between the respective collars and the respective inner ends, said rings having peripheral surfaces in sealing engagement with the internal surfaces of the respective cylinders and each of said cylinders having a fluid-admitting pressure port adjacent to the respective outer end and a fluid-discharging port adjacent to the respective inner end; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 30

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising discrete coaxial first and second cylinders and said second piston means constituting a twin piston having first and second stages respectively reciprocable in said first and second cylinders, each of said cylinders having an inner end nearer to and an outer end remote from the other cylinder and each of said stages having a collar located in the respective cylinder and remote from the respective inner end, said actuating motor means further comprising first and second rings sealingly surrounding and slidable on said first and second stages between the respective collars and the respective inner ends, said rings having peripheral surfaces in sealing engagement with the internal surfaces of the respective cylinders and each of said cylinders having a fluid-admitting pressure port adjacent to the respective outer end and a fluid-discharging port adjacent to the respective inner end; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 31

An assembly as defined in claim 24, wherein said discharging ports communicate with each other and said displacing means is rotatable on and axially movable with said second piston means intermediate said first and second cylinders.

Claim 32

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising first and second fluid-admitting pressure ports and said second piston means being movable between said neutral position and two operative positions whereby one of said pressure ports admits pressurized fluid to move said second piston means to one of said operative positions and the other pressure port admits pressurized fluid to move said second piston means to the other operative position; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means comprising normally closed first and second check valves respectively interposed between said source and said first and second ports and normally closed discrete electromagnetic pilot valves for said check valves.

Claim 33

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means comprising first and second fluid-admitting pressure ports and said second piston means being movable between said neutral position and two operative positions whereby one of said pressure ports admits pressurized fluid to move said second piston means to one of said operative positions and the other pressure port admits pressurized fluid to move said second piston means to the other operative position; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means comprising normally closed first and second check valves respectively interposed between said source and said first and second ports and normally closed discrete electromagnetic pilot valves for said check valves.

Claim 34

An assembly as defined in claim 26, wherein each of said check valves comprises a body having an inlet for pressurized fluid, an outlet connected with the respective pressure port, a valve element normally assuming a sealing position in which said inlet is sealed from said outlet, and a plunger movable axially in said body to thereby move said valve element from said sealing position, said plunger being arranged to move axially in response to energization of the respective pilot valve.

Claim 35

An assembly as defined in claim 26, wherein said valve means further comprises normally closed electromagnetic control valve means interposed between said source and said check valves.

Claim 36

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shiftiNg members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second piston means comprising a main piston and an auxiliary piston both sealingly received in and reciprocable relative to said second cylinder means, said auxiliary piston having a smaller-diameter extension extending toward said main piston and said main piston having a piston rod extending beyond one end of said second cylinder means in a direction away from said auxiliary piston, said actuating motor means further comprising a fluid-permeable partition provided in said second cylinder means to guide said extension and said second cylinder means having a first fluid-admitting port located at that side of said auxiliary piston which is remote from said main piston, a second fluid-admitting port located between said pistons, and a third fluid-admitting port adjacent to said one end of said second cylinder means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 37

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shiftiNg members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second piston means comprising a main piston and an auxiliary piston both sealingly received in and reciprocable relative to said second cylinder means, said auxiliary piston having a smaller-diameter extension extending toward said main piston and said main piston having a piston rod extending beyond one end of said second cylinder means in a direction away from said auxiliary piston, said actuating motor means further comprising a fluid-permeable partition provided in said second cylinder means to guide said extension and said second cylinder means having a first fluid-admitting port located at that side of said auxiliary piston which is remote from said main piston, a second fluid-admitting port located between said pistons, and a third fluid-admitting port adjacent to said one end of said second cylinder means; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means.

Claim 38

An assembly as defined in claim 29, wherein said valve means comprises a first check valve for admitting pressurized fluid to said first port, a normally deenergized first electromagnetic pilot valve which is energizable to thereby actuate said first check valve, a second check valve interposed between said source and said second port, a normally deenergized second electromagnetic pilot valve which is energizable to actuate said second check valve, a third check valve interposed between said third port and said source, and a normally deenergized third electromagnetic pilot valve which is energizable to actuate said third check valve.

Claim 39

An assembly as defined in claim 30, wherein said third check valve is arranged to control the admission of pressurized fluid from said source to said first and second check valves.

Claim 40

An assembly as defined in claim 31, wherein said first check valve is normally open and is arranged to close in response to energization of said first pilot valve, said second and third check valves being normally closed and being arranged to respectively open in response to energization of said second and third pilot valves.

Claim 41

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means having at least one fluid-admitting pressure port; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means comprising a check valve interposed between said source and said port and having a body provided with a seat, an inlet for pressurized fluid and an outlet connected with said port, a valve element movable into sealing engagement with said seat to thereby seal said inlet from said outlet, and a plunger movable in said body from an idle position to thereby move said valve element from said sealing position, said body further having a chamber adjacent to that axial end of said plunger which is remote from said valve element and said valve means further comprising pilot valve means actuatable to admit pressurized fluid into said chamber to thereby effect a movement of said valve element from said sealing position.

Claim 42

A gear shifting assembly for a change-speed transmission of the type having a plurality of shifting members actuatable to thereby set the transmission into different speed positions, said assembly comprising displacing means movable into register with each of said shifting members; a fluid-operated selector motor including first cylinder means and first piston means movable in said cylinder means between a plurality of positions to thereby effect a movement of said displacing means into register with selected shifting members; fluid-operated actuating motor means having second cylinder means and second piston means movable from a neutral position to at least one operative position to thereby actuate the selected shifting member by way of said displacing means, said second cylinder means having at least one fluid-admitting pressure port; a source of pressurized fluid; and automatic control means including remote control operated valve means for regulating the flow of fluid which is furnished by said source to and from said cylinder means, said valve means comprising a check valve interposed between said source and said port and having a body provided with a seat, an inlet for pressurized fluid and an outlet connected with said port, a valve element movable into sealing engagement with said seat to thereby seal said inlet from said outlet, and a plunger movable in said body from an idle position to thereby move said valve element from said sealing position, said body further having a chamber adjacent to that axial end of said plunger which is remote from said valve element and said valve means further comprising pilot valve means actuatable to admit pressurized fluid into said chamber to thereby effect a movement of said valve element from said sealing position.

Claim 43

An assembly as defined in claim 33, wherein said body of said check valve is further provided with a fluid-discharging second outlet which communicates with said first mentioned outlet in the sealing position of said valve element and is sealed from said first mentioned outlet by said plunger in response to admission of pressurized fluid into said chamber, said check valve further comprising means for biasing said valve element to said sealing position.

Claim 44

An assembly as defined in claim 34, wherein said body is further provided with a second chamber which communicates with said first mentioned outlet and a third chamber which communicates with said second outlet, said chambers being spaced from each other as considered in the axial direction of said plunger and said seat being provided between said inlet and said second chamber.

Claim 45

An assembly as defined in claim 1, further comprising manually operated means for moving at least one of said piston means in the event of failure of said valve means.

Claim 46

An assembly as defined in claim 36, wherein said one piston means is provided with a piston rod extending beyond the respective cylinder means and said manually operated means is separably secured to said piston rod without the respective cylinder means.