Work carrier drive for double disc grinder with reversible drive and automatic stop means

Claim 2

A grinding machine comprising a pair of coaxial abrasive discs, means for rotating said abrasive discs about the axes thereof, a work paddle, means for mounting a workpiece for rotational displacement on said work paddle, means for displacing said work paddle from a first retracted position whereat the workpiece is remote from said abrasive discs to a second advanced position whereat the workpiece is located in the grinding zone intermediate said rotating abrasive discs, first means for rotating the workpiece in a first direction when the workpiece is located within the grinding zone, second means for rotating the workpiece in a second opposite direction when the workpiece is located within the grinding zone, and means for periodically reversing the direction of rotation of the workpiece.

Claim 3

A grinding machine according to claim 1, further comprising means for stopping the rotation of the workpiece when the workpiece is rotating in either said first or second direction with the workpiece at a predetermined orientation.

Claim 4

A grinding machine according to claim 1, wherein a workpiece is ground to size each grinding cycle and said periodically reversing means comprises means for reversing the direction of rotation of the workpiece every grinding cycle.

Claim 5

A grinding machine according to claim 2 wherein said mounting means comprises a work carrier having a metallic sprocket wheel having a least a portion of at least one successive tooth cut thereoff defining a blank sprocket wheel portion, said first and second rotating means comprises a power transmission chain engaging with a portion of said sprocket wheel, a rotative motor means for driving said power transmission chain in either of said first or second directions at a grind speed, and means for reducing the speed of said motor means to reduce the power transmission chain speed to a slow speed, and said stopping means comprises first and second selectively enabled inductive proximity switches selectively located to sense the presence of only those sprocket teeth of said sprocket wheel which do not have said portion cut therefrom, means for preventing the actuation of said switches as successive sprocket teeth pass therepast, said preventing means being adapted to allow the actuation of said switches as said blank sprocket wheel portion passes past said switches means for terminating the rotation of said motor means, means for operating said grinding machine in a first mode when said work carrier is rotating in said first direction wherein said first and second switches will sequentially actuate said speed reducing means and said terminating means, and means for operating said grinding machine in a second mode when said work carrier is rotating in said second direction wherein said second and first switches will sequentially actuate said speed reducing means and said terminating means, said first and second switches being selectively separated, said blank portion having a selected length, and said preventing means being selectively adjusted so that said work carrier will stop rotating, regardless of rotative direction, at a predetermined orientation, and means for switching from one mode to the other when the direction of rotation of said work carrier changes from said one direction to said other direction.

Claim 6

A grindline machine according to claim 4 further comprising means for conjointly actuating said speed reducing means and enabling said second proximity switch when said grinding machine is operating in said first mode, and means for conjointly actuating said speed reducing means and enabling said first proximity switch when said grinding machine is operating in said second mode.

Claim 7

A grinding machine according to claim 4 wherein said preventing means comprises first and second timers.

Claim 8

A machine tool comprising a rotatable member having a metallic sprocket wheel having at least a portion of at least one successive tooth cut thereof defining a blank sprocket wheel portion, means for rotating said rotatable member including power transmission chain means engaging with a portion of said sprocket wheel, rotative motor means for driving said power transmission chain in first or second directions, and means for stopping said rotatable member, whether said rotatable member is rotating in said first or second directions, at a predetermined orientation including, first and second selectively enabled inductive proximity switches selectively located to sense the presence of only those sprocket teeth of said sprocket wheel which do not have said portion cut therefrom, means for preventing the actuation of said switches as successive sprocket teeth pass therepast, said preventing means being adapted to allow the actuation of said switches as said blank sprocket wheel portion passes past said switches, means for terminating the rotation of said motor means, means for operating said machine tool in a first mode when said rotatable member is rotating in said first direction wherein said first and second switches will sequentially actuate to energize said terminating means, means for operating said machine tool in a second mode when said rotatable member is rotating in said second direction wherein said second and first switches will sequentially actuate to energize said terminating means, and means for switching from one mode to the other mode when the direction of rotation of said rotatable member changes from one of said directions to the other one of said directions.

Claim 9

A machine tool comprising a rotatable member having a metallic sprocket wheel having at least a portion of at least one successive tooth cut thereof defining a blank sprocket wheel portion, means for rotating said rotatable member including power transmission chain means engaging with a portion of said sprocket wheel, rotative motor means for driving said power transmission chain in first or second directions, and means for stopping said rotatable member, whether said rotatable member is rotating in said first or second directions, at a predetermined orientation including, first and second selectively enabled inductive proximity switches selectively located to sense the presence of only those sprocket teeth of said sprocket wheel which do not have said portion cut therefrom, means for preventing the actuation of said switches as successive sprocket teeth pass therepast, said preventing means being adapted to allow the actuation of said switches as said blank sprocket wheel portion passes past said switches, means for terminating the rotation of said motor means, means for operating said machine tool in a first mode when said rotatable member is rotating in said first direction wherein said first and second switches will sequentially actuate to energize said terminating means, means for operating said machine tool in a second mode when said rotatable member is rotating in said second direction wherein said second and first switches will sequentially actuate to energize said terminating means, and means for switching from one mode to the other mode when the direction of rotation of said rotatable member changes from one of said directions to the other one of said directions.

Claim 10

A grinding machine according to claim 7 further comprising means for preventing actuation of said second switch prior to said first switch when said machine tool is operating in said first mode and means for preventing actuation of said first switch prior to said second switch when machine tool is operating in said second mode.

Claim 11

A grinding machine comprising a pair of coaxial abrasive discs, means for rotating said abrasive discs about the axes thereof, a work paddle, means for mounting a workpiece for rotational displacement on said workpaddle, said mounting means including a work carrier including an annular row of sprocket teeth extending peripherally thereabout intermediate adjacent peripherally extending track surfaces, a power transmission chain engaging, on the exterior surface thereof, with a portion of said sprocket teeth, rotative motor means for driving said power transmission chain, a pair of chain rollers mounted on said work paddle and including a pair of peripheral track surfaces for rolling engagement with said work carrier track surfaces and an annular groove having a width substantially equal to the width of said power transmission chain intermediate said roller track surfaces for permitting passage of said power traNsmission chain between said chain rollers and said work carrier, and a plurality of work carrier support rollers mounted on said work paddle remote from said sprocket teeth portion and including a pair of peripheral track surfaces for rolling engagement with said work carrier track surfaces and an annular groove substantially narrower than the width of said chain roller grooves intermediate said track surfaces for permitting passage of said sprocket teeth between said work carrier and said work support rollers.

Claim 12

A grinding machine comprising a pair of coaxial abrasive discs, means for rotating said abrasive discs about the axes thereof, a work paddle, means for mounting a workpiece for rotational displacement on said workpaddle, said mounting means including a work carrier including an annular row of sprocket teeth extending peripherally thereabout intermediate adjacent peripherally extending track surfaces, a power transmission chain engaging, on the exterior surface thereof, with a portion of said sprocket teeth, rotative motor means for driving said power transmission chain, a pair of chain rollers mounted on said work paddle and including a pair of peripheral track surfaces for rolling engagement with said work carrier track surfaces and an annular groove having a width substantially equal to the width of said power transmission chain intermediate said roller track surfaces for permitting passage of said power traNsmission chain between said chain rollers and said work carrier, and a plurality of work carrier support rollers mounted on said work paddle remote from said sprocket teeth portion and including a pair of peripheral track surfaces for rolling engagement with said work carrier track surfaces and an annular groove substantially narrower than the width of said chain roller grooves intermediate said track surfaces for permitting passage of said sprocket teeth between said work carrier and said work support rollers.