Fine feed system

Claim 2

A fine feed system, wherein a movable member movable relative to a stationary member is finely fed, comprising: a fine feed mechanism, including a first member and a second member, both of which are movable relative to each other and are secured to said movable member; a driving member operatively connected to said first member; a clamp device operable between a clamped and released conditions and provided on said second member, said clamp device, when in said clamped condition, effecting a coupling of said second member to said stationary member; movement regulating detector means having operable position detector elements at the ends of a range of movement for said movable member for defining a relatively movable range between said first and second members; and a control means for effecting an operation of said driving means and a movement of said movable member within said range when said operable position detector elements of said movement regulating detector means are not operated and for operating said driving means in a direction to return said first and said second members to an original relative position in response to said clamp device being in said released condition.

Claim 3

A fine feed system as set forth in claim 1, wherein said first member is a screwshaft, said second member is a nut member and said driving member is a motor.

Claim 4

A fine feed system as set forth in claim 2, wherein a speed change clutch, operable at a high speed connection and at a low speed connection, is operatively connected between said driving member and said screwshaft, and wherein said control means includes means for effecting operation of said speed change clutch at at least one of said high speed connection and said low speed connection, and wherein, when said screwshaft and said nut members are returned to said original relative positions, said screwshaft and said motor are connected to each other through said speed change clutch switched to said high speed connection by said control means.

Claim 5

A fine feed system as set forth in claim 1, wherein said clamp device comprises electromagnetic coupling means.

Claim 6

A fine feed system as set forth in claim 2, wherein said position detector elements for detecting the relative positions between said first and said second members are adjustable in position in a direction of relative movement.

Claim 7

A fine feed system as set forth in claim 2, wherein said position detector elements include a pair of switches for detecting the relative positions of said screwshaft and said nut member which are adjustable in position in the axial direction of said screwshaft.

Claim 8

A fine feed system as set forth in claim 6, wherein plural of said position detector elements are successively provided along the screwshaft and each of said detector elements are operated by the movement of said nut member.

Claim 9

A fine feed system as set forth in claim 1, wherein said control means includes; a clamp device operating portion; a fine feed operating portion; a clamp device operating circuit for operating said clamp device in said clamped condition when said clamp device operating portion is operated; a first control circuit for causing said driving means to operate on condition that said position detector elements of said movement regulating detector means have not operated and said clamp device is in said clamped condition when said fine feed operating portion is operated; and a second control circuit for causing said driving means to operate in a direction in which said first and said second members are returned to said original relative positions when said clamp device is in said released condition.

Claim 10

A fine feed system as set forth in claim 5, wherein said control means includes; a clamp device operating portion; a fine feed operating portion; a clamp device driving circuit for operating said clamp device in said clamped condition when said clamp device operating portion is operated; an alarm lamp; a signal identifying circuit for on-off operating or turning on said alarm lamp when at least one of said position detector elements is operated; a first control circuit for causing said driving means to operate on condition that said position detector elements of said movement regulating detector means have not operated and said clamp device is in said clamped condition when said fine feed operating portion is operated; and a second control circuit for causing said driving means to operate in a direction in which said screwshaft and said nut member are returned to said original relative positions on condition that said position detector elements have not operated and said clamp device is in said released condition.

Claim 11

In a fine feed system wherein a movable member is movable relative to and along a stationary member and said movable member is finely fed relative to said stationary member through a fine feed mechanism including two members movable relative to each other, the improvement comprising wherein: said fine feed mechanism includes a screwshaft and a nut member threadably coupled to said screwshaft, said screwshaft being provided on said movable member; a motor for rotatably driving said screwshaft; a speed change clutch is operatively connected between said motor and said screwshaft; said nut member has affixed thereto an electromagnetic means for coupling and uncoupling said nut member to said stationary member; and further movement regulating detector means having operable position detector elements at the ends of a range of movement for said movable member for defining a relatively movable range between said screwshaft and said nut member; a control means is provided for driving said driving means at low speed and at a high speed, said driving means driving at said low speed where a pair of said position detector elements regulate the relatively movable range between said screwshaft and said nut member said which have not operated, said driving means driving at a high speed for returning said screwshaft and said nut member to said original relative positions in response to said electromagnetic coupling means being uncoupled from said stationary member.

Claim 12

In a fine feed system wherein a movable member is movable relative to and along a stationary member and said movable member is finely fed relative to said stationary member through a fine feed mechanism including two members movable relative to each other, the improvement comprising wherein: said fine feed mechanism includes a screwshaft and a nut member threadably coupled to said screwshaft, said screwshaft being provided on said movable member; a motor for rotatably driving said screwshaft; a speed change clutch is operatively connected between said motor and said screwshaft; said nut member has affixed thereto an electromagnetic means for coupling and uncoupling said nut member to said stationary member; and further movement regulating detector means having operable position detector elements at the ends of a range of movement for said movable member for defining a relatively movable range between said screwshaft and said nut member; a control means is provided for driving said driving means at low speed and at a high speed, said driving means driving at said low speed where a pair of said position detector elements regulate the relatively movable range between said screwshaft and said nut member said which have not operated, said driving means driving at a high speed for returning said screwshaft and said nut member to said original relative positions in response to said electromagnetic coupling means being uncoupled from said stationary member.

Claim 13

A fine feed system as set forth in claim 10, wherein said position detector elements for detecting the relative positions of said screwshaft and said nut member are adjustable in position in the direction of relative movement.

Claim 14

A fine feed system as set forth in claim 11, wherein plural of said position detector elements are successively provided along said screwshaft and operated by the movement of said nut member as it moves adjacent thereto.

Claim 15

A fine feed system as set forth in claim 10, wherein said control means includes: a clamp device operating portion; a fine feed operating portion; a clamp device driving circuit operable for operating said electromagnetic coupling means in a coupled condition when said clamp device operating portion is operated; a first control circuit for causing said driving means to operate on condition that said position detector elements of said movement regulating detector means have not operated and said electromagnetic coupling means is in said coupled condition when said fine feed operating portion is operated; and a second control circuit for causing said driving means to operate in a direction in which said screwshaft and said nut member are returned to said original relative positions when said clamp device is in said uncoupled condition.

Claim 16

A fine feed system as set forth in claim 13, wherein an alarm lamp is provided; and wherein said control means further includes a signal identifying circuit for activating said alarm lamp when at least one of said position detector elements is operated.