Machine tools

Claim 2

A machine tool comprising a work table, means mounting said work table for pivotal movement about a first axis, a tool holder, means mounting said tool holder for pivotal movement about a second axis spaced from and parallel to said first axis, means for pivoting said work table and said tool holder about their respective axes through substantially identical angles in the same sense of rotation, and means for causing relative movement of said work table and said tool holder towards and away from each other.

Claim 3

A machine tool as claimed in claim 1 and further comprising at least two tool holders, said tool holders being spaced around said work table and each said tool holder being pivotally mounted about an axis parallel to and spaced from said axis of said work table, and means for pivoting said at least two tool holderS about their respective axes.

Claim 4

A machine tool as claimed in claim 1 wherein said means for pivoting said work table and said tool holder comprise a connecting rod extending parallel to a line joining, and perpendicular to said two axes, a first pivot joint pivotally connecting said connecting rod at a first joint to said work table, a second pivot joint pivotally connecting said connecting rod at a second point to said tool holder, said first and second points forming, together with coplanar points on said first and second axes, the four corners of a parallelogram, and means for moving said connecting rod longitudinally.

Claim 5

A machine tool as claimed in claim 1 and including means for moving said tool holder longitudinally on pivotal movement of said tool holder to maintain substantially constant the distance between the tip of a tool held in said tool holder and the closest point to said tip of a face of a workpiece mounted on said work table, said face being perpendicular to the longitudinal axis of said tool holder.

Claim 6

A machine tool as claimed in claim 1 wherein said tool holder comprises a first, tool-carrying part, a second part and a carriage, said first part being longitudinally movable relative to said second part and projecting from a first end of said second part; said second part being mounted for longitudinal movement in said carriage and said carriage being connected to said pivotal mounting means; and a second end of said second part bears against a profiled template secured to a base of said machine tool and shaped to cause said second part to move longitudinally in said carriage on pivotal movement of said tool holder.

Claim 7

A machine tool as claimed in claim 6 including an electric motor mounted on said first part of said tool holder, a spindle journalled in said first part, and a driving connection between said electric motor and said spindle.

Claim 8

A machine tool as claimed in claim 1 and including means mounting said work table for further pivotal movement about a third axis intersecting said first axis, means mounting said tool holder for further pivotal movement about a fourth axis intersecting said second axis, and means for pivoting said work table and said tool holder about said third and fourth axes respectively.

Claim 9

A machine tool as claimed in claim 7 wherein said first and second axes are parallel, and said third and fourth axes are parallel and are both perpendicular to said first and second axes.

Claim 10

A machine tool as claimed in claim 8 including interlocking means interlocking the pivoting of said work table and said tool holder about said third and fourth axes so that said work table and said tool holder mover simultaneously about said third and fourth axes through identical angles in the same sense of rotation.

Claim 11

A machine tool as claimed in claim 8 wherein said means for pivoting said work table and said tool holder about said third and fourth axes comprise a second connecting rod extending parallel to a line joining, and perpendicular to, said third and fourth axes, a third pivot joint pivotally connecting said second connecting rod at a third point to said work table, a fourth pivot joint pivotally connecting said second connecting rod at a fourth point to said tool holder, said third and fourth points forming, together with coplanar points on said third and fourth axes, the four corners of a further parallelogram, and means for moving said second connecting rod longitudinally.

Claim 12

A machine tool as claimed in claim 10 wherein said means for moving said tool holder longitudinally are effective to produce such longitudinal movement for any combination of pivotal movement of said tool holder about said second and fourth axes.

Claim 13

A machine tool as claimed in claim 5 wherein said profiled template is shaped to produce the desired longitudinal movement of said tool holder for any combination of pivotal movement of said tool holder about said second and fourth axes.

Claim 14

A machine tool comprising a fixed base; a veRtically extending first spindle journalled on said base for pivotal movement about a vertical first axis; a vertically extending second spindle journalled on said base for pivotal movement about a vertical second axis spaced from said first axis; a first clevis member secured to an upper end of said first spindle; a work table pivotally mounted on said first clevis member about a horizontal third axis intersecting said first axis; a second clevis member secured to an upper end of said second spindle; a tool holder pivotally mounted on said second clevis member about a horizontal fourth axis intersecting said second axis; a first connecting rod joined at a first point to said first clevis by a first vertical pivot joint and joined at a second point to said second clevis by a second vertical pivot joint, said first and second points forming, together with coplanar points on said first and second axes, the four corners of a first parallelogram; a second connecting rod joined at a third point to said work table by a first ball pivot joint and joined at a fourth point to said tool holder by a second ball pivot joint, said third and fourth points forming, together with coplanar points on said first and second axes, the four corners of a second parallelogram, and said third and fourth points also forming, together with coplanar points on said third and fourth axes, the four corners of a third parallelogram, the distance between the point of intersection of said first and third axes and the point of intersection of said second and fourth axes being equal to the distance between said first and second points and equal to the distance between said third and fourth points; means for moving said first connecting rod longitudinally, and means for moving said second connecting rod longitudinally.

Claim 15

A machine tool comprising a fixed base; a veRtically extending first spindle journalled on said base for pivotal movement about a vertical first axis; a vertically extending second spindle journalled on said base for pivotal movement about a vertical second axis spaced from said first axis; a first clevis member secured to an upper end of said first spindle; a work table pivotally mounted on said first clevis member about a horizontal third axis intersecting said first axis; a second clevis member secured to an upper end of said second spindle; a tool holder pivotally mounted on said second clevis member about a horizontal fourth axis intersecting said second axis; a first connecting rod joined at a first point to said first clevis by a first vertical pivot joint and joined at a second point to said second clevis by a second vertical pivot joint, said first and second points forming, together with coplanar points on said first and second axes, the four corners of a first parallelogram; a second connecting rod joined at a third point to said work table by a first ball pivot joint and joined at a fourth point to said tool holder by a second ball pivot joint, said third and fourth points forming, together with coplanar points on said first and second axes, the four corners of a second parallelogram, and said third and fourth points also forming, together with coplanar points on said third and fourth axes, the four corners of a third parallelogram, the distance between the point of intersection of said first and third axes and the point of intersection of said second and fourth axes being equal to the distance between said first and second points and equal to the distance between said third and fourth points; means for moving said first connecting rod longitudinally, and means for moving said second connecting rod longitudinally.

Claim 16

A machine tool as claimed in claim 13 wherein said tool holder comprises a first, tool-carrying part, a second part and a carriage, said first part being longitudinally movable relative to said second part and projecting from a first end of said second part; said second part being mounted for longitudinal movement in said carriage and said carriage being pivotally mounted on said second clevis; and a second end of said second part bears against a profiled template secured to a base of said machine tool and shaped to cause said second part of said tool holder to move longitudinally in said carriage on any combination of pivotal movement of said tool holder about said third and fourth axes.

Claim 17

A machine tool as claimed in claim 14 including a flange on said second part of said tool holder, and a compression spring acting between said carriage and said flange to bias said second part into engagement with said profiled template.

Claim 18

A machine tool as claimed in claim 2 including interlocking means interlocking the pivoting of said work table and said tool holders so that as said work table is moved through a given angle in a given sense of rotation, all said tool holders are moved through an equal angle in the same sense of rotation.

Claim 19

A machine tool as claimed in claim 16 and including, in association with each said tool holder, a member pivotally connected at a first point to said work table and pivotally connected at a second point to said tool holder, said two points forming, together with coplanar points on said axes of said work table and said tool holder, the four corners of a parallelogram, and means are provided for longitudinally moving one of said members.

Claim 20

A machine tool as claimed in claim 2 and including means for moving each said tool holder longitudinally on pivotal movement of said tool holder to maintain substantially constant the distance between the tip of a tool held in said tool holder and the closest point to said tip of a face of a workpiece mounted on said work table, said face being perpendicular to said axis of said tool holder.

Claim 21

A machine tool as claimed in claim 1 wherein said work table comprises a base, a turntable top rotatable relative tO a base, and means locking said top and said base in any selected one of a number of relative angular positions.