A machine tool for machining a workpiece (2) comprises a machine base (18), a workpiece holder (14) supported by the machine base for holding a workpiece (2), the holder being rotatable about an axis (15), and a workpiece rotary drive (10, Mw, Ew) for rotating the holder about the axis. A tool mount (16) is supported by the machine base for carrying a tool (4) to be engaged with a workpiece held in the holder, and a drive arrangement is operable to move the workpiece holder and the tool mount relative to each other in a plane which is transverse with respect to the axis. A control arrangement (6) is configured to control the workpiece rotary drive and the drive arrangement so as to machine a surface profile on the workpiece which is non- equidistant from the axis (15) in a plane which is transverse with respect to the axis, such that a tool (4) mounted in the mount is engaged with the workpiece (2) to commence the machining operation whilst the workpiece is being rotated by the workpiece drive. A method of machining a workpiece is also provided.
B24B 5/42 - Single-purpose machines or devices for grinding crankshafts or crankpins
B24B 19/12 - Single purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section for grinding cams or camshafts
B23B 5/18 - Turning-machines or devices specially adapted for particular workAccessories specially adapted therefor for turning crankshafts, eccentrics, or cams, e.g. crankpin lathes
An assembly for carrying a measuring gauge (10) to be maintained in contact with a portion of a workpiece (3) mounted in a machine tool arranged to rotate the workpiece about a machine reference axis (14). The assembly is for mounting on a carriage shared with a material removing tool (1) and comprises a slide (6) which is slidable in the direction of infeed of said material removing tool (1). A mount coupling (8) is pivotally coupled to the slide by a pivot (7) and is arranged to accommodate variation of the spacing between the mount and the pivot due to the rotary motion of said workpiece portion. A slide driver (5) is arranged to reciprocate the slide relative to the slide support in synchronism with the rotation of said workpiece portion. An associated method is also provided.
B24B 5/42 - Single-purpose machines or devices for grinding crankshafts or crankpins
B24B 49/04 - Measuring or gauging equipment for controlling the feed movement of the grinding tool or workArrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent involving measurement of the workpiece at the place of grinding during grinding operation
3.
A COUNTERFORCE MECHANISM AND METHODS OF OPERATION THEREOF
A counterforce mechanism is arranged to exert a force on an object to maintain the object at a desired position. The mechanism comprises a driven body (12, 62, 94), a drive (20, 60, 92) for moving the driven body, and a resilient coupling arrangement (26, 70, 88) for coupling the driven body to a portion of an object. A control arrangement is arranged to output a drive signal to the driven body drive to move the driven body to a location where it exerts a force on the object via the coupling arrangement, such that the force counteracts an opposing force acting on the object and the mechanism holds the portion of the object at the desired position. A machine axis and a machine tool incorporating such a counterforce mechanism are also described, together with methods of operation thereof.
B23Q 11/00 - Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling workSafety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
A machine tool is provided which comprises a machine base (10); a first support (200) provided on a first rotational machine axis, the first rotational axis being mounted on the base in a fixed position relative to the base; a second support (202) provided on a second rotational machine axis, the second rotational axis being mounted on the base in a fixed position relative to the base, wherein the axis of rotation of the second rotational axis is parallel to and spaced laterally from the axis of rotation of the first rotational axis. A mount is carried by a support arm on the second support, with the support arm being moveable relative to the second support about a rotary axis (210, 232, 252). A control arrangement is operable to control the orientation of the first support relative to the axis of rotation of the first rotational axis, and the orientation of the mount relative to the axis of rotation of the second rotational axis and its rotational position about the rotary axis, so as to govern the position and orientation of the first support and the mount relative to each other. Combination of motion about three rotational axes in this way facilitates versatile and accurate control of the relative orientations of the first support and the mount on the second support. The machine base may include a central support (320) located between the machine axes (322, 324), with the machine axes mounted onto opposite sides of the support.
B23Q 1/54 - Movable or adjustable work or tool supports using particular mechanisms with rotating pairs only two rotating pairs only
B24B 19/00 - Single purpose machines or devices for particular grinding operations not covered by any other main group
B23Q 1/01 - Frames, beds, pillars or like membersArrangement of ways
B24B 5/04 - Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfacesAccessories therefor involving centres or chucks for holding work for grinding cylindrical surfaces externally
B24B 27/04 - Grinding machines or devices in which the grinding tool is supported on a swinging arm
B23B 5/08 - Turning-machines or devices specially adapted for particular workAccessories specially adapted therefor for turning axles, bars, rods, tubes, rolls, i.e. shaft-turning lathes, roll lathesCentreless turning
A machine tool is provided which comprises a machine base (10), a first support (20,100) mounted on a first rotational machine axis on the base, and a second support (22,102) mounted on a second rotational machine axis on the base. The second rotational axis is parallel to and spaced laterally from the first rotational axis and carries a mount (38,112) moveable relative to the second support along a first linear machine axis orthogonal to the second rotational axis. A control arrangement is operable to control the orientation of the first support on the first rotational axis, and the orientation of the mount relative to the second rotational axis and its location along the linear axis, so as to govern the position and orientation of the first support and the mount relative to each other. Existing machine tools often use long linear guide rails and stacked orthogonal axes which introduce alignment and offset errors. The present invention avoids the need for and/or reduces the number of these structures in machine tools.
A turning machine is provided for machining a workpiece with respect to a longitudinal axis (14) of the machine. The machine comprises a base (2), a headstock (10) and a tailstock (12) supported by the base for mounting respective ends of the workpiece (8) such that it is rotatable about said longitudinal axis, and a carriage (4) for carrying a tool (24) to engage with the io workpiece. The carriage is moveable parallel to said longitudinal axis along two guideways on the base, wherein the guideways are located in use on either side of and spaced horizontally from said longitudinal axis. The machine configuration seeks to reduce roll and/or pitch errors occurring as the carriage moves along the workpiece.
A method of grinding a workpiece with a grinding wheel is provided wherein the shape of the wheel is distorted in a predetermined manner during grinding by changing the speed of rotation of the wheel. This deformation of the wheel during grinding is employed to impart a desired shape to the surface of the workpiece. A grinding wheel is also provided which is asymmetric in side view to adapt it for use in accordance with the method.
B24B 19/06 - Single purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements for grinding races, e.g. roller races
A support assembly (8) is provided for supporting a grinding wheel drive assembly (10, 12) on a grinding machine. The support assembly comprises a support body (28) rotatably mounted on a base (22), and a direct drive motor for rotating the body relative to the base. The motor includes a rotor (30) carried by the support body and a stator (26) mounted on the base. The support body may be supported during rotation by at least one hydrostatic thrust bearing (32, 34, 36, 38). The support body may include a flange (40) which extends around its rotational axis, with a clamp assembly provided to grip the flange and thereby hold the support body in a selected rotational position. The support body may carry a grinding spindle at one station and a tool turret mounting tool on another station. A grinding machine including such a support assembly and methods of operation thereof are also described.
B24B 5/00 - Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfacesAccessories therefor
B23Q 1/26 - Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable membersMeans for preventing relative movement of such members
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