Controller for DC arc welding generators

Abstract

The controller automatically and remotely controls the stopping and running of an internal combustion engine coupled to a DC generator that supplies DC power to the welding cables of an arc welding machine. The engine has a starter, an ignition, and an intake manifold. A vacuum-actuated switching means is coupled to the intake manifold and is responsive to the vacuum produced therein. A switching circuit is coupled to and is controlled by the vacuum-actuated switching means. A starter and an ignition are coupled to the switching circuit. A timer having a predetermined timing interval is coupled to the switching circuit, to the welding circuit, and to the ignition.

What is claimed is: 
     
       1. A controller for remotely starting and automatically stopping an internal combustion engine coupled to a DC generator that supplies DC power to the welding cables of an arc welding circuit, the engine having a starter, an ignition, and an intake manifold, comprising in combination: a DC power source for providing a control current to said welding circuit, a current-blocking device for blocking said control current from said generator, and a current sensing device for sensing the flow of welding current,   a vacuum-actuated switching means coupled to said intake manifold and being responsive to the vacuum produced therein,   a switching circuit coupled to and controlled by said vacuum-actuated switching means,   a starter coupled to said switching circuit,   an ignition coupled to said switching circuit,   a timer having a predetermined timing interval and being coupled (1) to said switching circuit, (2) to said welding circuit, and (3) to said ignition,   said switching circuit, upon establishing continuity between said cables for said control current, energizing said ignition and said starter, thereby enabling the starting of said engine, and   said timer stopping said engine if welding current does not flow through said cables at any time during the timing interval of said timer.   
     
     
       2. The controller of claim 1, wherein said vacuum-actuated switching means includes a vacuum-operated motor having a shaft which is spring-biased toward the motor, and tending to move outwardly in response to a vacuum in said intake manifold, and a relay responsive to said control current for energizing said ignition and for inhibiting the movement of said shaft. 
     
     
       3. The controller of claim 2, wherein the movement of said shaft is resumed upon the breaking of said continuity following the making of said continuity thereby applying a voltage to said electrodes for a welding operation. 
     
     
       4. The controller of claim 3, wherein said shaft carries a switch having normally open contacts in series with one of the welding cables. 
     
     
       5. A controller for remotely starting and automatically stopping an internal combustion engine coupled to a DC generator that supplies DC power to the welding electrodes of an arc welding circuit, the engine having a starter, an ignition, and an intake manifold, comprising in combination: a DC power source for providing a control current to said welding circuit, a current-blocking device for blocking said control current from said generator, and a current sensing means for sensing the flow of welding current,   a vacuum-actuated switching means coupled to said intake manifold and being responsive to the vacuum produced therein,   an ignition circuit energizing the ignition of said engine,   a starter circuit energizing the starter of said engine,   a switching circuit energized by said control current upon making of the welding electrodes,   a timer circuit energized through said vacuum-actuated switching means and being controlled by the output of said sensing means,   said ignition circuit being energized through said switching circuit and said timer circuit,   a logic circuit being energized through said switching circuit,   said starter circuit being energized through said switching circuit and said logic circuit, and said logic circuit during consecutive time delays T1 and T2 latching said switching circuit and energizing said ignition circuit, and during time delay T2 energizing said starter circuit, thereby enabling said engine to start,   the starting of the engine creating a vacuum in said intake manifold which moves the vacuum-actuated switching means to de-energize said starter circuit and said logic circuit, and to energize said timer circuit for producing a timing interval, and   said timer circuit de-energizing said ignition circuit thereby stopping the engine, if welding current is not sensed by the sensing means at any time during the timing interval.   
     
     
       6. The controller of claim 5 wherein said switching circuit includes a relay having normally-open contacts and a blocking diode in series with said relay. 
     
     
       7. The controller of claim 6 wherein said ignition circuit includes a relay having normally open contacts. 
     
     
       8. The controller of claim 7 wherein said logic circuit includes a pair of multi-vibrators connected in series. 
     
     
       9. The controller of claim 8 wherein the output of each multi-vibrator is connected to a transistor. 
     
     
       10. The controller of claim 9 wherein said timer circuit comprises an output transistor and an electronic timer coupled to the input of said transistor, the output of said transistor being connected to said switching means and to said ignition circuit. .Iadd. 11. In an arc welding system including a DC generator for providing welding current to a welding rod, and an internal combustion engine for powering the DC generator, the engine having a starter and an ignition, the improvement comprising apparatus for controlling the starting and stopping of the engine, which control apparatus comprises: (a) circuitry for: (i) automatically energizing the ignition and starter of the internal combustion engine, responsive to contact between the welding rod and the material to be welded; (ii) automatically de-energizing the starter responsive to the operation of the engine; and (iii) providing welding current to the welding rod from the DC generator; and   (b) a timer which operates to automatically de-energize the ignition of said engine, when welding has been interrupted for a predetermined period of time, said ignition remaining de-energized until the welding rod again contacts material to be welded. .Iaddend..Iadd. 12. The apparatus of claim 11, wherein the circuitry includes switching circuitry for providing electrical currents to energize the starter and the ignition when the welding rod contacts the material to be welded. .Iaddend..Iadd. 13. The apparatus of claim 12, wherein the circuitry includes switching circuitry for interrupting the flow of current to the starter, responsive to the operation of the engine. .Iaddend..Iadd. 14. The apparatus of claim 11, wherein the internal combustion engine produces a vacuum during operation and wherein the circuitry includes means responsive to the vacuum produced by the operation of the engine to de-energize the starter. .Iaddend. .Iadd. 15. The apparatus of claim 11, wherein the circuitry includes:   a switching circuit which generates a first signal and second signal responsive to contact between the welding rod and the material to be welded;   a logic circuit which generates a third signal responsive to the first signal from the switching circuit;   a starter circuit for energizing the starter of the engine responsive to the third signal from the logic circuit; and   an ignition circuit responsive to the second signal from the switching circuit for energizing the ignition of the engine. .Iaddend. .Iadd. 16. In an arc welding system including a DC generator for providing welding current to a welding rod and an internal combustion engine for powering the DC generator, the engine having a starter and an ignition, apparatus for controlling the starting and stopping of the engine, which control apparatus comprises:   (a) a switching circuit which generates a first signal and a second signal responsive to contact between the welding rod and the material to be welded;   (b) a logic circuit which generates a third signal responsive to the first signal from the switching circuit;   (c) a starter circuit for energizing the starter of the engine responsive to the third signal from the logic circuit;   (d) an ignition circuit responsive to the second signal from the switching circuit for energizing the ignition of the engine; and   (e) a timer which operates to automatically de-energize the ignition circuit of the engine when welding has been interrupted for a predetermined period of time, said ignition circuit remaining de-energized until the welding rod again contacts the material to be welded.   
     
     
        .Iaddend..Iadd. 17.  In an arc welding system including a DC generator for providing welding current to a welding rod and an internal combustion engine powering the DC generator, the engine having a starter and an ignition, apparatus for controlling the starting and stopping of the engine, which control apparatus comprises: (a) a switching circuit which generates a first signal and a second signal responsive to contact between the welding rod and the material to be welded;   (b) a starter circuit for energizing the starter of the engine responsive to the first signal from the switching circuit;   (c) an ignition circuit responsive to the second signal from the switching circuit for energizing the ignition of the engine; and   (d) a timer which operates to automatically de-energize the ignition circuit when welding has been interrupted for a predetermined period of time, said ignition circuit remaining de-energized until the welding rod again contacts the material to be welded..Iaddend.