Flame cutting torch control

Claim 2

A flame cutting torch assembly for flame cutting of a workpiece and the like comprising a cutting torch means establishing a cutting flame directed into engagement with said workpiece, position sensor means establishing a fluid sensing stream for engagement of the workpiece adjacent to said flame, drive means for positioning said cutting torch means and said sensor means relative to the workpiece, control means for sensing the flow characteristic of said sensing stream and connected to actuate said drive means to selectively position said torch means and said sensor means with respect to said workpiece, said torch means being held within a predetermined maximum and minimum spacing from the workpiece, and said ontrol means includes a first response means responsive to said minimum spacing to actuate the drive means to move the support means away from said work member, a second response means responsive to said maximum spacing to actuate the drive means to move the support means toward the work member, and a third response means responsive to a spacing of the torch unit from said work member in a predetermined excess of said maximum spacing to deactivate said drive means.

Claim 3

The cutting torch assembly of claim 1 havinga common movable support member coupled to said drive means for moving said support member, said cutting torch means being secured to said support member, said sensor means including a nozzle means secured to said support member in predetermined relationship to said cutting torch, said nozzle means having an orifice establishing said fluid sensing stream, and said control means sensing the back pressure in said nozzle means upstream of said orifice and connected to actuate said drive means to selectively position said torch means with respect to said workpiece.

Claim 4

The cutting torch assembly of claim 2 wherein said first, second and third response means are responsive to the back pressure to correspondingly actuate the drive means.

Claim 5

The cutting torch assembly of claim 1 wherein said drive means including a reversible electric motor having an up-running input means and a down-running input means, aNd said control means establishes a fluid pressure signal in accordance with the spacing of the torch means from said workpiece, and said drive means including fluid pressure activated switch means selectively supplying power to said input means to selectively position said torch means with respect to said workpiece.

Claim 6

The cutting torch assembly of claim 4 wherein said switch means includes a first fluid activated switch connected to the down running input means and a second fluid activated switch connected to the uprunning input means, and a lost work means coupled to both said switches to prevent operative actuation of the switches in the absence of workpiece in the path of said stream.

Claim 7

The cutting torch assembly of claim 4 wherein said switch means includes a first fluid activated switch connected to the down running input means and a second fluid activated switch connected to the up running input means, a common lost plate fluid activated switch connected to both said first and second switches for controlling power input to said switches, and each of said switches having a fluid signal input means connected in common to said control means to simultaneously apply said fluid pressure signal to said switches.

Claim 8

The cutting torch assembly of claim 4 wherein said switch means includes a first fluid activated switch connected to the down running input means and a second fluid activated switch connected to the up running input means, a first dual input fluid logic gate connected to said second switch, a second triple input fluid logic gate connected to said first switch, three adjustable fluid pressure amplifiers connected in common to said control means and establishing binary logic signals related to said fluid pressure signal, the first of said amplifiers establishing a signal related to selected minimum spacing of the torch from the workpiece and connected to one input of said second logic gate, the second of said amplifiers establishing a signal related to a selected maximum spacing of the torch from the workpiece and connected to a second input of said second logic gate, the third of said amplifiers establishing a signal related to a selected spacing in excess of said maximum, inverting signal means connecting said third amplifiers to the third input of said second logic gate, and inverting signal means connecting each of said first and second amplifiers to one each of one input of said first gate.

Claim 9

A cutting torch assembly comprising a torch unit to be held within a predetermined maximum and minimum spacing from the workpiece, and control means including a first detecting and response means responsive to said minimum spacing to move the torch unit away from said work member, a second detecting and response means responsive to said maximum spacing to move the torch unit toward the work member, a third detecting and response means responsive to a spacing of the torch unit from said work member in a predetermined excess of said maximum spacing to hold said torch unit in the last position, said control means including a fluid sensing means having a flowing detection stream engaging said workpiece and coupled to actuate said response means.

Claim 10

A cutting torch assembly comprising a torch unit to be held within a predetermined maximum and minimum spacing from the workpiece, and control means including a first detecting and response means responsive to said minimum spacing to move the torch unit away from said work member, a second detecting and response means responsive to said maximum spacing to move the torch unit toward the work member, a third detecting and response means responsive to a spacing of the torch unit from said work member in a predetermined excess of said maximum spacing to hold said torch unit in the last position, said control means including a fluid sensing means having a flowing detection stream engaging said workpiece and coupled to actuate said response means.

Claim 11

A cutting torch assembly comprising a torch unit to be held in alignment with and within a predetermined spacing from the workpiece, control means connected to said sensing means and including a detecting and response means responsive to said fluid signal to move the torch unit with respect to said workpiece to provide a controlled spacing of the torch unit relative to the work member, and a work loss detecting and response means responsive to the fluid signal with torch unit and workpiece out of alignment to hold said torch unit in the last position.

Claim 12

A cutting torch assembly comprising a torch unit to be held in alignment with and within a predetermined spacing from the workpiece, control means connected to said sensing means and including a detecting and response means responsive to said fluid signal to move the torch unit with respect to said workpiece to provide a controlled spacing of the torch unit relative to the work member, and a work loss detecting and response means responsive to the fluid signal with torch unit and workpiece out of alignment to hold said torch unit in the last position.