Machine tool monitoring system

Claim 1

A device for measuring the time during which a machine tool is performing work wherein the machine tool comprises an electrically conductive work member and is adapted to receive an electrically conductive work piece and wherein the work member and the work piece are electrically connected together when both the work member and work piece rotate with respect to each other and mechanically contact each other and wherein the work piece and the work member are electrically insulated from each other when the work piece and the work member are both out of mechanical contact with each other and are rotating with respect to each other, the improvement comprising: means for producing a varying electrical signal in accordance with the rotation of said work piece; first amplifying means for amplifying said rotation signal; means for converting said rotation signal into a substantially constant amplitude rotation signal; a first power source connected to said converting means; first measuring means connected to said power source and adapted to be actuated by said first power source when said substantially constant amplitude rotation signal is transmitted by said converting means; a second power source having a first terminal coupled to said work piece and a second terminal connected to said work member; a resistor connected in series between said second terminal and said second power source, said resistor having a relatively high resistance compared with the resistance of the work member and said machine tool so that a substantial no-cutting alternating signal appears across said resistor only when work is not being performed by said machine tool; second amplifying means connected across said resistor for amplifying said no-cutting signal; rectifying means connected to said second amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; switch means connected to said second amplifier and to said converting means adapted to transmit a cutting signal only when both a rotation signal is present and when said no-cutting signal is absent from the input of said switch means; and second measuring means connected to said first power source, said first power source also being connected to said switch means, said second measuring means being adapted to be actuated by said first power source when a cutting signal is transmitted by said switch means.

Claim 2

A device for measuring the time during which a machine tool is performing work wherein the machine tool comprises an electrically conductive work member and is adapted to receive an electrically conductive work piece and wherein the work member and the work piece are electrically connected together when both the work member and work piece rotate with respect to each other and mechanically contact each other and wherein the work piece and the work member are electrically insulated from each other when the work piece and the work member are both out of mechanical contact with each other and are rotating with respect to each other, the improvement comprising: means for producing a varying electrical signal in accordance with the rotation of said work piece; first amplifying means for amplifying said rotation signal; means for converting said rotation signal into a substantially constant amplitude rotation signal; a first power source connected to said converting means; first measuring means connected to said power source and adapted to be actuated by said first power source when said substantially constant amplitude rotation signal is transmitted by said converting means; a second power source having a first terminal coupled to said work piece and a second terminal connected to said work member; a resistor connected in series between said second terminal and said second power source, said resistor having a relatively high resistance compared with the resistance of the work member and said machine tool so that a substantial no-cutting alternating signal appears across said resistor only when work is not being performed by said machine tool; second amplifying means connected across said resistor for amplifying said no-cutting signal; rectifying means connected to said second amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; switch means connected to said second amplifier and to said converting means adapted to transmit a cutting signal only when both a rotation signal is present and when said no-cutting signal is absent from the input of said switch means; and second measuring means connected to said first power source, said first power source also being connected to said switch means, said second measuring means being adapted to be actuated by said first power source when a cutting signal is transmitted by said switch means.

Claim 3

A device for measuring the time during which a machine tool is performing work wherein the machine tool comprises an electrically conductive work member and which is adapted to receive an electrically conductive work piece and wherein the work member and work piece are electrically connected together when both the work member and work piece rotate with respect to each other and mechanically contact each other and wherein the work piece and the work member are electrically insulated from each other by a dielectric lubricant when the work piece and the work member are both out of mechanical contact with each other and are rotating with respect to each other, the improvement comprising: means for producing a varying electrical signal in accordance with said rotation; first amplifying means connected to said rotation signal producing meAns for amplifying said rotation signal; means connected to said first amplifying means for converting said varying rotation signal into a substantially constant amplitude rotation signal; second amplifying means connected to said converting means for amplifying said substantially constant amplitude rotation signal; a first clock having a clock motor; a first alternating power source coupled to the motor of said first clock; first gate means connected to said second amplifying means and to said first power source, said gate means being adapted to be actuated by said substantially constant amplitude rotation signal to couple said first power source to said first clock motor only when said rotation signal is transmitted by said second amplifying means in order to provide a measurement of the time of said rotation; first and second brushes coupled to said work piece; a second alternating power source having a first terminal connected to the first brush and having a second terminal connected to said work member and to the second brush; a resistor connected in series between said second brush and said second terminal of said second power source, said resistor having a relatively high resistance compared to the resistance of said work member and said machine tool so that a substantial no-cutting alternating signal appears across said resistor only when work is not being performed by said machine tool; third amplifying means connected across said resistor for amplifying said no-cutting signal; rectifying means connected to said third amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; second gate means connected to said third amplifying means and to said converting means to receive said substantially constant amplitude no-cutting signal and said constant amplitude rotation signal, said second gate means having an inhibitor on said no-cutting signal so that a cutting signal is transmitted through the second gate only when a rotation signal is present and a no-cutting is absent from the input of said second gate, said second gate thereby transmitting a cutting signal only when work is being performed by said machine tool; fourth amplifying means connected to said second gate means; a second clock having a second clock motor coupled to said first power source; and third gate means connected to said fourth amplifying means and to said first power source, said third gate means being adapted to couple the first power source to the second clock motor only when said cutting signal is transmitted by said fourth amplifying means in order to provide a measurement of the time during which the machine is performing work.

Claim 4

A device for measuring the time during which a machine tool is performing work wherein the machine tool comprises an electrically conductive work member and which is adapted to receive an electrically conductive work piece and wherein the work member and work piece are electrically connected together when both the work member and work piece rotate with respect to each other and mechanically contact each other and wherein the work piece and the work member are electrically insulated from each other by a dielectric lubricant when the work piece and the work member are both out of mechanical contact with each other and are rotating with respect to each other, the improvement comprising: means for producing a varying electrical signal in accordance with said rotation; first amplifying means connected to said rotation signal producing meAns for amplifying said rotation signal; means connected to said first amplifying means for converting said varying rotation signal into a substantially constant amplitude rotation signal; second amplifying means connected to said converting means for amplifying said substantially constant amplitude rotation signal; a first clock having a clock motor; a first alternating power source coupled to the motor of said first clock; first gate means connected to said second amplifying means and to said first power source, said gate means being adapted to be actuated by said substantially constant amplitude rotation signal to couple said first power source to said first clock motor only when said rotation signal is transmitted by said second amplifying means in order to provide a measurement of the time of said rotation; first and second brushes coupled to said work piece; a second alternating power source having a first terminal connected to the first brush and having a second terminal connected to said work member and to the second brush; a resistor connected in series between said second brush and said second terminal of said second power source, said resistor having a relatively high resistance compared to the resistance of said work member and said machine tool so that a substantial no-cutting alternating signal appears across said resistor only when work is not being performed by said machine tool; third amplifying means connected across said resistor for amplifying said no-cutting signal; rectifying means connected to said third amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; second gate means connected to said third amplifying means and to said converting means to receive said substantially constant amplitude no-cutting signal and said constant amplitude rotation signal, said second gate means having an inhibitor on said no-cutting signal so that a cutting signal is transmitted through the second gate only when a rotation signal is present and a no-cutting is absent from the input of said second gate, said second gate thereby transmitting a cutting signal only when work is being performed by said machine tool; fourth amplifying means connected to said second gate means; a second clock having a second clock motor coupled to said first power source; and third gate means connected to said fourth amplifying means and to said first power source, said third gate means being adapted to couple the first power source to the second clock motor only when said cutting signal is transmitted by said fourth amplifying means in order to provide a measurement of the time during which the machine is performing work.

Claim 7

A device for measuring the time during which a machine tool performs work wherein said machine tool comprises a work piece and a rotating member, said measuring device comprising: means adapted to produce a varying electrical signal in accordance with the rotation of said rotating member; first amplifying means connected to said rotation signal producing means for amplifying said rotation signal; means connected to said first amplifying means for converting said varying rotation signal to a substantially constant amplitude rotation signal; second amplifying means connected to said converting means for amplifying said substantially constant amplitude rotation signal; a first clock having a clock motor; a first alternating power source coupled to the motor of said first clock; first gate means connected to said second amplifying means and to said first power source, said gate means being adapted to be actuated by said substantially constant amplitude rotation signal to couple said first power source to said first clock motor only when said rotation signal is transmitted by said second amplifying means; a second alternating power source having a first terminal adapted to be coupled to said work piece and having a second terminal adapted to be coupled to said machine tool and to said work piece; a resistor connected in series between said second terminal and said second work piece, said resistor having a relatively high resistance compared with the resistance of said work piece and said machine tool; third amplifying means connected across said resistor for amplifying no-cutting signals appearing across said resistor; rectifying means connected to said third amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; second gate means connected to said third amplifying means and to said converting means to receive said substantially constant amplitude no-cutting signal and said substantially constant amplitude rotation signal, said second gate means having an inhibitor on said no-cutting signal so that a cutting signal is transmitted through the second gate only when a rotation signal is present and a no-cutting signal is absent from the input of the gate; fourth amplifying means connected to said second gate means; a second clock having a second clock motor coupled to said first power source; and third gate means connected to said fourth amplifying means and to said first power source, said third gate means being adapted to couple the first power source to the second clock motor only when said cutting signal is transmitted by said fourth amplifying means.

Claim 8

A device for measuring the time during which a machine tool performs work wherein said machine tool comprises a work piece and a rotating member, said measuring device comprising: means adapted to produce a varying electrical signal in accordance with the rotation of said rotating member; first amplifying means connected to said rotation signal producing means for amplifying said rotation signal; means connected to said first amplifying means for converting said varying rotation signal to a substantially constant amplitude rotation signal; second amplifying means connected to said converting means for amplifying said substantially constant amplitude rotation signal; a first clock having a clock motor; a first alternating power source coupled to the motor of said first clock; first gate means connected to said second amplifying means and to said first power source, said gate means being adapted to be actuated by said substantially constant amplitude rotation signal to couple said first power source to said first clock motor only when said rotation signal is transmitted by said second amplifying means; a second alternating power source having a first terminal adapted to be coupled to said work piece and having a second terminal adapted to be coupled to said machine tool and to said work piece; a resistor connected in series between said second terminal and said second work piece, said resistor having a relatively high resistance compared with the resistance of said work piece and said machine tool; third amplifying means connected across said resistor for amplifying no-cutting signals appearing across said resistor; rectifying means connected to said third amplifying means for converting said no-cutting signal into a substantially constant amplitude no-cutting signal; second gate means connected to said third amplifying means and to said converting means to receive said substantially constant amplitude no-cutting signal and said substantially constant amplitude rotation signal, said second gate means having an inhibitor on said no-cutting signal so that a cutting signal is transmitted through the second gate only when a rotation signal is present and a no-cutting signal is absent from the input of the gate; fourth amplifying means connected to said second gate means; a second clock having a second clock motor coupled to said first power source; and third gate means connected to said fourth amplifying means and to said first power source, said third gate means being adapted to couple the first power source to the second clock motor only when said cutting signal is transmitted by said fourth amplifying means.