Servo controlled height control

Claim 3

A system in accordance with claim 1, in which the tool operates at a temperature deleterious to the operation of available electric or electronic devices, together with tubular pressure-transmitting means leading from said sensor to a location remote from the tool and fluidic apparatus at said latter location to which said tubular means is connected, said fluidic apparatus being comprised within said pressure-responsive space adjusting means, whereby the deleterious effect of the operating temperature of the tool upon the operation of the system is minimized.

Claim 4

A system in accordance with claim 1, in which said space-adjusting means comprises reversible driving means for moving the tool with respect to the workpiece, a push-pull pressure operable diaphragm device for controlling said driving means to energize the same and to determine the direction of motion thereof, means to generate a push-pull pressure signal for operating said diaphragm device, said generating means comprising fluidic inverter means and first and second fluidic OR means, means to impress an input signal upon said first and second OR means, said first OR means generating an output signal in one sense, said second OR means connected to said inverter means to generate an output signal in the opposite sense, thereby to provide push-pull pressures to actuate said diaphragm device.

Claim 5

A system in accordance with claim 1, in which said sensor means are normally movable as a unit with the tool when changing the tool and workpiece spacing, together with means to produce relative motion of said tool and said sensor means.

Claim 6

A system in accordance with claim 1, together with resilient mounting means for said sensor means whereby the sensor can deflect when striking an obstruction, and means operable when said sensor is deflected to direct said stream of fluid from said stream-directing means into said stream-receiving means without reflection, whereby the received stream indicates a too close proximity of the tool and workpiece, enabling the control system to withdraw the sensor from contact with said obstruction.

Claim 7

A system in accordance with claim 5, in which the said resilient mounting means is effective to restore the said sensor to normal operation upon being withdrawn from contact with said obstruction.

Claim 8

A system in accordance with claim 1, in which there are exactly four peripheral holes.

Claim 9

A system in accordance with claim 1, in which the said peripheral holes are so directed as to cause the said streams of fluid to converge upon the workpiece surface substantially opposite the said axial hole.

Claim 10

An apparatus in accordance with claim 1 wherein said sensor means comprises a plurality of individual sensors spaced about said tool.

Claim 11

An apparatus in accordance with claim 9, wherein said control means comprises two fluidic OR means each having at least one input for each said sensor means, said inputs on each OR means connected to one of said sensors, the output of one OR means connected to a fluidic-to-electric transducer means, the output of the second OR means connected to a fluidic inverter which has an output which is in turn connected to said transducer, and said transducer responsive to the two input signals to produce said control signal.

Claim 12

An apparatus in accordance with claim 9, wherein the output of each of said fluidic OR means is substantially the same whether there is a signal on one of its inpuTs or all of its inputs and the output is predominantly determined by the input of greatest magnitude.

Claim 13

A system in accordance with claim 10, in which said fluidic-to-electric transducer comprises a pair of fluid actuated diaphragms, and means mechanically coupling said diaphragms.

Claim 14

A system in accordance with claim 9, together with a pressure manifold in the form of a ring arranged to pass through said sensor means to supply fluid at operating pressure in common to said sensors.

Claim 15

A system in accordance with claim 10, together with a unitary fluid pressure supply manifold in the form of a perforated block of metal, said manifold comprising inlet means to receive fluid at pressure in excess of operating pressure, means to reduce fluid pressure in a plurality of stages, means to adjust pressure supplies to individual fluidic devices in said system, and means to measure fluid pressure at selected points within said block.

Claim 16

A system in accordance with claim 12, in which said fluidic-to-electric transducer comprises a mechanically operable electric switch mounted adjacent to, but spaced from, one of said diaphragms in position to be operated by displacement of said diaphragm, whereby said spacing provides a dead band for said switch with respect to said diaphragm, thereby to minimize false operation of said switch by noise pulses in said diaphragm.