Automatic control for return motion of cutoff saw head

Claim 2

A cUtoff saw having a base, means on the base defining a feed path along which stock to be cut can be advanced in one direction, a cutting head comprising a power driven blade with a portion which has a cutting edge and lies in a defined cutting plane that is generally normal to said path, said cutting head being mounted for movement to carry said blade portion edgewise in said cutting plane and across said path in opposite cutting and return directions, power actuating means for moving the cutting head in its said directions, and control means for said actuating means having selectable cutting and return conditions to provide, respectively, for movement of the cutting head in said cutting and return directions, said cutoff saw being characterized by means for automatically so controlling motion of the cutting head in its return direction as to prevent stock advancing along said path from colliding with the cutting head but also prevent return movement of the cutting head beyond the point at which it is clear of advancing stock, the last mentioned means comprising: A. stock sensing means constrained to move in the cutting and return directions in unison with the cutting head in a zone near the cutting plane and operative to produce one output when stock is present along a line in said zone which is transverse to said path and to the directions of cutting and return motion of the cutting head and which line moves with the cutting head so as to be at all times spaced from the feed path by a distance not greater than the spacing therefrom of said cutting edge, said stock sensing means being responsive to the absence of stock from along said line to produce a different output; and B. means so connecting the stock sensing means with the control means when the latter is in its return condition as to effect motion of the cutting head in its return direction in response to said one output and to prevent such motion of the cutting head in response to said different output.

Claim 3

means providing a light source directed toward the photoresponsive cell, the light source and photoresponsive cell having their axes on said line and being located at opposite sides of said path so that the cell produces said first output when stock intervenes between it and the light source and produces said second output when there is no stock between it and the light source.

Claim 4

means providing a light source directed toward the photoresponsive cell, the light source and photoresponsive cell having their axes on said line and being located at opposite sides of said path so that the cell produces said first output when stock intervenes between it and the light source and produces said second output when there is no stock between it and the light source.

Claim 5

The cutoff saw of claim 1, further characterized by: said stock sensing means comprising

Claim 6

means mounting the sensing arm for swinging motion in said cutting and return directions and biasing it in the cutting direction;

Claim 7

means mounting the sensing arm for swinging motion in said cutting and return directions and biasing it in the cutting direction;

Claim 8

moves with the cutting head so as to be at all times spaced from the feed path by a distance not greater than the spacing therefrom of said cutting edge, said means comprising an output producing sensing element constrained to move in unison with the cutting head and at least a part of which is normally located on said line to respond to the presence of stock therealong by producing an output; and B. means so connecting said sensing element with the control means as to cause the cutting head to be moved in its return direction only when said output is produced and the control means is in its return condition.

Claim 9

moves with the cutting head so as to be at all times spaced from the feed path by a distance not greater than the spacing therefrom of said cutting edge, said means comprising an output producing sensing element constrained to move in unison with the cutting head and at least a part of which is normally located on said line to respond to the presence of stock therealong by producing an output; and B. means so connecting said sensing element with the control means as to cause the cutting head to be moved in its return direction only when said output is produced and the control means is in its return condition.

Claim 10

means operatively connecting said power means with the control means and with the stock sensing means for rendering the power means inoperative in response to said one output and operative in response to said different output.

Claim 11

means operatively connecting said power means with the control means and with the stock sensing means for rendering the power means inoperative in response to said one output and operative in response to said different output.

Claim 12

means cooperable with the sensing arm to define a normal position of swinging motion thereof toward which the sensing arm is biased and in which it extends along said line;

Claim 13

means cooperable with the sensing arm to define a normal position of swinging motion thereof toward which the sensing arm is biased and in which it extends along said line;

Claim 14

The cutoff saw of claim 1, further characterized by said stock sensing means comprising:

Claim 15

The cutoff saw of claim 3, wherein said zone in which the stock sensing means is located is spaced upstream from the cutting plane relative to said direction in which stock is advanced, further characterized by: said means mounting the sensing arm also providing for swinging motion thereof to and From its normal position in directions parallel to the feed path, and biasing the arm in the direction opposite to that in which stock is advanced.

Claim 16

a control element having an actuator movable back and forth between defined positions at which said outputs are respectively produced;

Claim 17

a control element having an actuator movable back and forth between defined positions at which said outputs are respectively produced;

Claim 18

means holding the control element and the mounting means for the sensing arm in a fixed relation to one another and constraining them to move bodily in the cutting and return directions in unison with the cutting head; and

Claim 19

means holding the control element and the mounting means for the sensing arm in a fixed relation to one another and constraining them to move bodily in the cutting and return directions in unison with the cutting head; and

Claim 20

The cutoff saw of claim 4, further characterized by:

Claim 21

A cutoff saw having a base, means on the base defining a feed path along which stock to be cut can be advanced in one direction, a cutting head comprising a power driven blade with a portion which has a cutting edge and lies in a defined cutting plane that is generally normal to said path, said cutting head being mounted for movement to carry said blade portion edgewise in said cutting plane and across said path in opposite cutting and return directions, power actuating means for moving the cutting head in its said directions, and control means for said actuating means having selectable cutting and return conditions to provide, respectively, for movement of the cutting head in said cutting and return directions, said cutoff saw being characterized by automatic means for so controlling motion of the cutting head in its return direction as to prevent stock advancing along said path from colliding with the cutting head but also prevent return movement of the cutting head beyond the point at which it is clear of advancing stock, the last mentioned means comprising: A. a mechanical feeler; B. mounting means for the feeler constrained to move in unison with the cutting head in said cutting and return directions and by which the feeler is carried for bodily motion with the mounting means and for motion relative thereto in said cutting and return directions; C. means biasing the feeler in said cutting direction; D. means cooperating with said mounting means and said biasing means to define a normal position of the feeler towards which it is urged by the biasing means and in which at least a part of the feeler lies on a line near the cutting plane, which line extends transversely to said path and to said cutting and return directions, moves with the cutting head, and is spaced from said path by a distance no greater than the spacing therefrom of said cutting edge; and E. output producing means operatively associated with the control means when it is in its return condition and operatively associated with the feeler to respond to its position and by which one output is produced when the feeler is out of its normal position that effects motion of the cutting head in its return direction and by which another output is produced when the feeler is in its normal position that prevents such motion of the cutting head.

Claim 22

A cutoff saw having a base, means on the base defining a feed path along which stock to be cut can be advanced in one direction, a cutting head comprising a power driven blade with a portion which has a cutting edge and lies in a defined cutting plane that is generally normal to said path, said cutting head being mounted for movement to carry said blade portion edgewise in said cutting plane and across said path in opposite cutting and return directions, power actuating means for moving the cutting head in its said directions, and control means for said actuating means having selectable cutting and return conditions to provide, respectively, for movement of the cutting head in said cutting and return directions, said cutoff saw being characterized by automatic means for so controlling motion of the cutting head in its return direction as to prevent stock advancing along said path from colliding with the cutting head but also prevent return movement of the cutting head beyond the point at which it is clear of advancing stock, the last mentioned means comprising: A. a mechanical feeler; B. mounting means for the feeler constrained to move in unison with the cutting head in said cutting and return directions and by which the feeler is carried for bodily motion with the mounting means and for motion relative thereto in said cutting and return directions; C. means biasing the feeler in said cutting direction; D. means cooperating with said mounting means and said biasing means to define a normal position of the feeler towards which it is urged by the biasing means and in which at least a part of the feeler lies on a line near the cutting plane, which line extends transversely to said path and to said cutting and return directions, moves with the cutting head, and is spaced from said path by a distance no greater than the spacing therefrom of said cutting edge; and E. output producing means operatively associated with the control means when it is in its return condition and operatively associated with the feeler to respond to its position and by which one output is produced when the feeler is out of its normal position that effects motion of the cutting head in its return direction and by which another output is produced when the feeler is in its normal position that prevents such motion of the cutting head.

Claim 23

means providing a motion transmitting connection between the sensing arm and the actuator of the control element whereby said actuator is caused to occupy one of its said positions when the sensing arm is in its normal position and to occupy the other of its said positions when the sensing arm is out of its normal position.

Claim 24

means providing a motion transmitting connection between the sensing arm and the actuator of the control element whereby said actuator is caused to occupy one of its said positions when the sensing arm is in its normal position and to occupy the other of its said positions when the sensing arm is out of its normal position.

Claim 25

A cutoff saw having a base, means on the base defining a feed path along which stock to be cut can be advanced in one direction, a cutting head comprising a power driven blade with a portion which has a cutting edge and lies in a defined cutting plane that is generally normal to said path, said cutting head being mounted for movement to carry said blade portion edgewise in said cutting plane and across said path in opposite cutting and return directions, power actuating means for moving the cutting head in its said directions, and control means for said actuating means having selectable cutting and return conditions to provide, respectively, for movement of the cutting head in said cutting and return directions, said cutoff saw being characterized by automatic means for so controlling motion of the cutting head in its return direction as to prevent stock advancing along said path from colliding with the cutting head but also prevent return movement of the cutting head and beyond the point at which it is clear of advancing stock, the last mentioned means comprising: A. means for sensing the presence of stoCk along a line near the cutting plane, which line

Claim 26

A cutoff saw having a base, means on the base defining a feed path along which stock to be cut can be advanced in one direction, a cutting head comprising a power driven blade with a portion which has a cutting edge and lies in a defined cutting plane that is generally normal to said path, said cutting head being mounted for movement to carry said blade portion edgewise in said cutting plane and across said path in opposite cutting and return directions, power actuating means for moving the cutting head in its said directions, and control means for said actuating means having selectable cutting and return conditions to provide, respectively, for movement of the cutting head in said cutting and return directions, said cutoff saw being characterized by automatic means for so controlling motion of the cutting head in its return direction as to prevent stock advancing along said path from colliding with the cutting head but also prevent return movement of the cutting head and beyond the point at which it is clear of advancing stock, the last mentioned means comprising: A. means for sensing the presence of stoCk along a line near the cutting plane, which line