Actuating mechanism for friction clutches in automatic motor vehicle transmissions

Claim 2

An actuating arrangement for first and second friction clutch means comprising: a first actuating piston means for actuating the first clutch means, a second actuating piston means for actuating the second clutch means, said second actuating piston means being movably guided in a cylinder formed by said first actuating piston means, first supply means for supplying a pressure medium to force said first piston means in a direction corresponding to engagement of said first clutch means, and second supply means for supplying a pressure medium to force said second piston means in a direction corresponding to engagement of said second clutch means, said first piston means being in communication with said second supply means such that supply of said pressure medium to force said second piston means in a direction corresponding to engagement of said second clutch means simultaneously applies a force on said first piston means in a direction corresponding to disengagement of said first clutch means, wherein said first actuating piston means is subdivided into a first and a second partial piston, wherein the first partial piston is arranged for directly actuating said first clutch means, and wherein the second partial piston is operatively connected for movement with the first partial piston only in the direction corresponding to engagement of said first clutch means with the second partial piston being movable independently of the first partial piston in the direction corresponding to disengagement of said first clutch means.

Claim 3

An arrangement according to claim 1, wherein said first and second clutch means are arranged such that they are separately engageable by selective control of the respective first and second supply means and are simultaneously engageable by utilizing both said first and second supply means to simultaneously supply pressure medium to force said both piston means in their respective clutch engaging directions.

Claim 4

An arrangement according to claim 1, characterized in that the friction clutch means are lamellae friction clutches for shifting an automatic motor vehicle transmission.

Claim 5

An arrangement according to claim 1, characterized in that the second partial piston is non-rotatably guided in a part accommodating the actuating piston means.

Claim 6

An installation according to claim 1, characterized in that the first partial piston is arranged concentrically about the second partial piston, and in that the second partial piston is provided with an annular flange means at the outer circumference for the axial entrainment of the first partial piston, said annular flange means abutting against the end face of the first partial piston when said piston means is moved in the direction corresponding to engagement of said first clutch means.

Claim 7

An actuating arrangement for first and second friction clutch means comprising: a first actuating piston means for actuating the firSt clutch means, a pressure medium for actuating said first piston means, a second actuating piston means for actuating the second clutch means, and a pressure medium for actuating said second piston means, said first actuating piston means simultaneously forming a cylinder accommodating the second actuating piston means, said first actuating piston means being subdivided into a first and a second partial piston, the first partial piston directly actuating said first clutch means, the second partial piston being operatively connected with the first partial piston only in the clutch engaging direction with the second partial piston being able to move independently of the first partial piston in the clutch disengaging direction, wherein the second partial piston in its disengaged position is supported with an annular surface on its back side against a part forming the cylinder for the actuating means, and wherein said annular surface is provided with approximately radially extending grooves for the passage therethrough of the pressure medium in the outward direction.

Claim 8

An actuating arrangement for first and second friction clutch means comprising: a first actuating piston means for actuating the firSt clutch means, a pressure medium for actuating said first piston means, a second actuating piston means for actuating the second clutch means, and a pressure medium for actuating said second piston means, said first actuating piston means simultaneously forming a cylinder accommodating the second actuating piston means, said first actuating piston means being subdivided into a first and a second partial piston, the first partial piston directly actuating said first clutch means, the second partial piston being operatively connected with the first partial piston only in the clutch engaging direction with the second partial piston being able to move independently of the first partial piston in the clutch disengaging direction, wherein the second partial piston in its disengaged position is supported with an annular surface on its back side against a part forming the cylinder for the actuating means, and wherein said annular surface is provided with approximately radially extending grooves for the passage therethrough of the pressure medium in the outward direction.

Claim 9

An installation according to claim 6, characterized in that the first partial piston is arranged concentrically about the second partial piston, and in that the second partial piston is provided with an annular flange means at the outer circumference for the axial entrainment of the first partial piston, said annular flange means abutting against the end face of the first partial piston, which is effective in the engaging direction.

Claim 10

An arrangement according to claim 1, wherein said second partial piston is non-rotatably guided in a part accommodating said piston means by pin means which engage with play in corresponding bores at the second partial piston.

Claim 11

An installation according to claim 8, characterized in that the first partial piston is arranged concentrically about the second partial piston, and in that the second partial piston is provided with an annular flange means at the outer circumference for the axial entrainment of the first partial piston, said annular flange means abutting against the end face of the first partial piston when said first piston means is moved in the direction corresponding to engagement of said first clutch means.

Claim 12

An actuating arrangement for first and second friction clutch means comprising: a first actuating piston means for actuating the first clutch means, a pressure medium for actuating said first piston means, a second actuating piston means for actuating the second clutch means, and a pressure medium for actuating said second piston means, said first actuating piston means simultaneously forming a cylinder accommodating the movement of the second actuating piston means, and first actuating piston means being subdivided into a first and a second partial piston, the first partial piston directly actuating said first clutch means, the second partial piston being operatively connected with the first partial piston only in the clutch engaging direction with the second partial piston being able to move independently of the first partial piston in the clutch disengaging direction, wherein the second partial piston is non-rotatably guided in a part accommodating the actuating piston means by pin means which engage with play in corresponding bores at the second partial piston, wherein the first partial piston is arranged concentrically about the second partial piston, the second partial piston being provided with an annular flange means at the outer circumference for the axial entrainment of the first partial piston, said annular flange means abutting against the end face of the first partial piston, which is effective in the engaging direction, the second partial piston in its disengaged position being supported with an annular surface on its back side against the part forming the cylinder for the actuating means, said annular surface being provided with approximately radially extending grooves for the passage therethrough of the pressure medium in the outward direCtion.

Claim 13

An actuating arrangement for first and second friction clutch means comprising: a first actuating piston means for actuating the first clutch means, a pressure medium for actuating said first piston means, a second actuating piston means for actuating the second clutch means, and a pressure medium for actuating said second piston means, said first actuating piston means simultaneously forming a cylinder accommodating the movement of the second actuating piston means, and first actuating piston means being subdivided into a first and a second partial piston, the first partial piston directly actuating said first clutch means, the second partial piston being operatively connected with the first partial piston only in the clutch engaging direction with the second partial piston being able to move independently of the first partial piston in the clutch disengaging direction, wherein the second partial piston is non-rotatably guided in a part accommodating the actuating piston means by pin means which engage with play in corresponding bores at the second partial piston, wherein the first partial piston is arranged concentrically about the second partial piston, the second partial piston being provided with an annular flange means at the outer circumference for the axial entrainment of the first partial piston, said annular flange means abutting against the end face of the first partial piston, which is effective in the engaging direction, the second partial piston in its disengaged position being supported with an annular surface on its back side against the part forming the cylinder for the actuating means, said annular surface being provided with approximately radially extending grooves for the passage therethrough of the pressure medium in the outward direCtion.

Claim 14

An arrangement according to claim 9, characterized in that the friction clutch means are lamellae friction clutches for shifting an automatic motor vehicle transmission.