US 4,099,110 A · Proportional control for guidance system

Abstract

A guidance system for positioning a welding apparatus with respect to a seam or joint to be welded by sensing changes in the surface of the seam. The torch of the apparatus is mounted upon and positioned by a motor-driven cross-slide providing both horizontal and vertical movement. A probe is adapted to follow the reference surfaces. Two variable resistors within the probe detect horizontal and vertical deviations of these surfaces. A voltage on each variable resistor is used to generate pulses which are applied to a SCR network through which power is supplied to the corresponding slide positioning motor. The voltage supplied to the motor corresponds in magnitude and polarity to the deviation in the direction of the path being followed by the probe and welding apparatus. The invention also includes a circuit for disabling the motors when the respective cross-slides reach the limits of their travel.

Claims3

Dependent claims

In an electrical circuit for controlling an apparatus-positioning motor controlled by a motor-driving circuit, a disabling circuit, comprising:

an optical transistor having an emitter, a collector, and a light-emitting diode,
the emitter and collector being in electrical connection with the motor-driving circuit whereby conduction by said optical diode disables the motor-driving circuit,
a normally closed switch, which is opened at a predefined limit of travel of the positioning motor, connected across the light-emitting diode of said optical transistor,
whereby when a voltage is impressed upon the light-emitting diode and said switch is opened, said optical transistor conducts thereby disabling the positioning motor.

1 more element

Dependencies are inferred from the claim text.

Proportional control for guidance system

Life of this patent

Proportional control for guidance system

Life of this patent

Abstract

Claims3