Machine tools

Claim 2

A tool turret assembly for a machine tool comprising: a turret head arranged to be movable to present different tools at an operating station; an axially movable operating member; said turret head being mounted on said operating member; means for accurately locating said turret in tool presenting positions; means for rotating said turret through an angle corresponding to the angle between the tool presenting positions; said operating member operable to engage said locating means and said rotating means respectively in axially displaced positions; said operating member comprising a piston sliding in a cylinder operable to cause said axial movement; means comprising imcompressible fluid applied to a face of the piston causing movement of the piston; and a hydrostatic bearing operative during rotation provided between another face of the piston and the end of the cylinder remote from said first-mentioned face.

Claim 3

A tool turret assembly as claimed in claim 1 in which said piston is provided with a face gear to engage another face gear on said means for rotating.

Claim 4

A tool turret assembly as clAimed in claim 2 in which the face gears are in the form of a dog clutch.

Claim 5

A tool turret assembly as claimed in claim 1 wherein said means for rotating is hydraulically actuated and said piston acts as a valve member controlling the flow of fluid to said means for rotating.

Claim 6

A turret assembly as claimed in claim 4 in which said means for rotating comprises a movable radial vane arranged for movement in a housing through angles corresponding to the angles through which the turret is indexed.

Claim 7

A tool turret assembly as claimed in claim 5 wherein said moving vane is arranged to be returnable to an initial position.

Claim 8

A tool turret assembly as claimed in claim 1 in which said means for rotating and the piston and cylinder are interconnected in a hydraulic power circuit.

Claim 9

A tool turret assembly as claimed in claim 7 in which the hydraulic circuit is arranged to be operable under the action of a solenoid operated change-over valve.

Claim 10

A tool turret assembly as claimed in claim 1 in which said means for rotating and said piston and said cylinder are in a common assembly and are located adjacent to one another.

Claim 11

A tool turret assembly as claimed in claim 9 in which said means for rotating surrounds said piston and is located between the turret head and the end of said piston remote therefrom.

Claim 12

A tool turret assembly as claimed in claim 1 wherein said piston has passages and said bearing is maintained by hydraulic fluid passing through said passages.

Claim 13

A tool turret assembly as claimed in claim 11 in which the passages in said piston are formed to communicate with the space below the piston to which hydraulic fluid is supplied to raise the piston.

Claim 14

A tool turrest assembly as claimed in claim 12 in which restrictor valves are provided in the passages to control the hydrostatic pressure.

Claim 15

A tool turret assembly as claimed in claim 1 wherein said means for accurately locating said turret comprises interengaging face gears on said turret and said operating member.

Claim 16

A tool turret assembly as claimed in claim 14 in which the interengaging face gears are formed by hirth rings.

Claim 17

A tool turret assembly as claimed in claim 15 in which the turret is arranged to be indexed through 60* for each tool presenting position and the hirth rings have 96 teeth.

Claim 18

A tool turret assembly as claimed in claim 1 having means for damping rotation of said turret proximate terminal positions of rotation of the turret through said angle corresponding to the angle between the tool presenting positions.

Claim 19

A tool turret assembly for a machine tool comprising: a turret head arranged to be movable to present different tools at an operating station; an axially movable operating member; said turret head being mounted on said operating member; means for accurately locating said turret in predetermined rotatably displaced positions; means for rotating said turret through an angle corresponding to the angle between tool presenting positions; said operating member operable to engage said locating means and said rotating means respectively in axially displaced positions; said operating member comprising a piston sliding in a cylinder operable to cause said axial movement; and a hydrostatic bearing operative during rotation provided between a face of the piston and said operating member.

Claim 20

A tool turret assembly for a machine tool comprising: a turret head arranged to be movable to present different tools at an operating station; an axially movable operating member; said turret head being mounted on said operating member; means for accurately locating said turret in predetermined rotatably displaced positions; means for rotating said turret through an angle corresponding to the angle between tool presenting positions; said operating member operable to engage said locating means and said rotating means respectively in axially displaced positions; said operating member comprising a piston sliding in a cylinder operable to cause said axial movement; and a hydrostatic bearing operative during rotation provided between a face of the piston and said operating member.

Claim 21

A tool turret assembly for a machine tool comprising: a turret head arranged to be movable to present different tools at an operating station; an axially movable operating member; said turret head being mounted on said operating member; means for accurately locating said turret head in predetermined rotatably displaced positions; said rotatably displaced positions precisely corresponding to tool presenting positions of said turret wherein said rotatably displaced positions are displaced from one another by an angle precisely corresponding to the angle between tool presenting posiTions; said angle between tool presenting positions being precisely the same between any pair of adjacent tool presenting positions as for any other pair of adjacent tool presenting positions; means for rotating said turret through an angle corresponding to the angle between tool presenting positions; said operating member operable to engage said locating means and said rotating means respectively in axially displaced positions; said operating member comprising a piston sliding in a cylinder operable to cause said axial movement; said means for rotating having rotatable elements rotating about the central axis of said piston and being independent of and unengagable with any mechanical linkages and any mechanical parts rotating about an axis that is not coaxial with said piston.

Claim 22

A tool turret assembly for a machine tool comprising: a turret head arranged to be movable to present different tools at an operating station; an axially movable operating member; said turret head being mounted on said operating member; means for accurately locating said turret head in predetermined rotatably displaced positions; said rotatably displaced positions precisely corresponding to tool presenting positions of said turret wherein said rotatably displaced positions are displaced from one another by an angle precisely corresponding to the angle between tool presenting posiTions; said angle between tool presenting positions being precisely the same between any pair of adjacent tool presenting positions as for any other pair of adjacent tool presenting positions; means for rotating said turret through an angle corresponding to the angle between tool presenting positions; said operating member operable to engage said locating means and said rotating means respectively in axially displaced positions; said operating member comprising a piston sliding in a cylinder operable to cause said axial movement; said means for rotating having rotatable elements rotating about the central axis of said piston and being independent of and unengagable with any mechanical linkages and any mechanical parts rotating about an axis that is not coaxial with said piston.