CA1232029A - Remotely controllable arc welder and combined auxiliary power unit - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An inductor alternator of the type used in a motor vehicle is combined with throttle control apparatus having a vacuum diaphragm that is communicable via a solenoid operated vacuum valve with the intake manifold of the vehicle engine and is operated thereby to actuate linkage connecting the diaphragm to the throttle of the engine carburetor. A
function switch selects one of two operating modes, the first providing a regulated do voltage output for battery charging and the second providing an unregulated do voltage output that varies directly with engine running speed and which is suitable for arc welding, battery boosting or powering small resistive appliances, floodlights and the like. In the first mode the vehicle's battery is connected to the do output of the alternator via a solenoid switch but is disconnected in the second mode to prevent damage by an overvoltage. In the second mode, the output voltage is available at either a polarized receptacle or via a pair of welding cables. A
local switch actuates the vacuum valve to increase engine speed in the second mode to obtain a fixed output voltage suitable for appliance operation whereas a remote control switch on a welding rod holder runs up engine speed to develop a welding voltage only for as long as the switch is held closed. When released, the engine speed drops to a preset minimum, thereby economizing on fuel consumption.

Description

~32~29 BACKGROUND OF THE INVENTION
This invention relates to arc welding apparatus that is powered by an inductor alternator of a motor vehicle and more particularly to such apparatus that is remotely controllable to function as an auxiliary power unit.
Arc welding apparatus in mobile installations has been employed advantageously in agricultural and other apply-cations where welding repairs may be effected in the field.
This feature is of particular benefit where breakdown occurs in agricultural equipment at a location remote from a repair shop which may necessitate at least a temporary repair in the field in order to permit transporting the equipment back to the repair shop for a more permanent repair. Not only does this reduce the down time of the broken down agricultural equipment but it could also mean that an immediate field repair may prevent further damage and could, often as not, comprise a complete repair requiring no further attention at the repair shop.
Another advantageous use to which a mobile arc I welder is applied is that of using its power unit as a booster supply to start motor vehicle engines under cold weather conditions when a vehicle battery is virtually dead and almost frozen from exposure. Under such circumstances, the power unit of the arc welder is adaptable to operate also as a battery charger that is capable of charging any battery in a voltage range of from 6 to 24 volts at charging currents ranging up to as much as 150 amperes.
Moreover, the auxiliary power unit of a mobile arc welder is particularly well suited to perform as an emergency power supply, providing an output that is readily capable 'I

2~9 of energizing resistive loads for operating incandescent spot and floodlighting equipment as well as small appliances such as hot plates, percolators, toasters and the like. It is apparent, therefore, that these features are well suited to other applications such as recreational activities which means that a mobile arc welder and auxiliary power unit has applications which may be encountered on a regular basis as when camping or when working in remote areas.
Furthermore, it is known in the art that an arc welder which operates from an inductor alternator provides a more smooth, superior weld than that provided by standard welders operating at low voltage and high current. This is due directly to a high frequency component in the welding current.
A high frequency finished weld therefore presents a weld no-squiring little, if any, manual burnishing to improve its appearance.
Since individual components of the apparatus to which this invention relates are well known to individuals skilled in the art of mobile arc welders, and because the circuit arrangement of a welding system is relatively simple, it is likely that miniseries would tend to buy the required components in kit form and personally install same in order to effect a monitory savings. A mobile arc welding system in kit form should therefore include components that are readily installed using conventional hand tools that would normally be in the possession of the user.
Moreover, a simple system design would permit ready installation on motor vehicles, or motorized trailers. Since in most instances the inductor alternator, which comprises a major component of an arc welding system, will be employed ~232CP~9 in its conventional capacity as a source of charging voltage for the vehicle battery, the system should be designed to operate efficiently in the motor vehicle without having any deleterious effect on standards set by original equipment manufacturers for engine compartment components.

SUMMARY OF THE INVENTION
A principal objector the present invention is the provision of a remotely controllable arc welder and combined auxiliary power unit that will function in a 100~ duty cycle mode, both as an arc welder and as an auxiliary power unit.
Another object of the invention is the provision of such welder and power unit which is simple in design and easily installed on a motor vehicle using conventional hand tools.
Still another object of the invention is the pro-vision of a remotely controllable arc welder and combined auxiliary power unit capable of predetermined low and high voltage outputs.
Yet another provision of the invention is such an arc welder and power unit that is compatible with most motor vehicles without deleterious effect on original equipment manufacturers functional standards of engine compartment components.
Still another object of the invention is the pro-vision of a remotely controllable arc welder and combined auxiliary power unit which is capable of functioning in either a regulated or unregulated mode.
The known requirements for an efficient mobile arc welder and combined auxiliary power unit, together with the foregoing provisions, are substantially achieved by recourse ~3Z~

to my invention which is a remotely controllable arc welder and combined auxiliary power unit that comprises, an inductor alternator adapted to be rotatable driven by an internal combustion engine, the alternator having a stators winding terminal, a pair of direct current output terminals, a corresponding pair of battery terminals and a pair of field winding terminals. Additionally, the arc welder and power unit comprises throttle control means operably connected to a carburetor of the engine for controlling the running speed thereof, the throttle control means being communicable with an intake manifold of the engine and responsive to a reduced pressure thereat for increasing the engine running speed.
Valve means controllable communicating the throttle control means with the manifold are also included with first switch means for controllable enabling and disabling the valve means whereby the alternator is rotatable driven through a prefer-mined range of engine speeds for generating a corresponding range of direct current voltages across the output terminals.
And second switch means interposed between corresponding ones of at least one terminal of the pair of direct current output terminals and the pair of battery terminals are controllable to selectively connect together and disconnect the respective terminals.

GRIEF DESCRIPTION OF THE DRAWINGS
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The invention will now be more particularly described with reference to an embodiment thereof, shown by way of example, in the accompanying drawing in which Fig. 1 is a schematic diagram of a remotely controllable arc welder and combined auxiliary power unit configured in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
_ A preferred embodiment of the present invention is illustrated in Fig. 1 in the form of a schematic diagram of a remotely controllable arc welder and combined power unit 10. It will be observed that the unit includes an inductor alternator 11 which is rotatable driven Vim a drive belt 12 from an internal combustion engine (not shown) of the motor vehicle or a trailer with a like engine mounted thereon.
Although the unit 10 is operable with an inductor alternator usually accompanying the engine, the circuit of Fig. 1 is particularly well suited for use with a heavy duty alternator that is capable of functioning in a lC0% duty cycle at an output of 100 amperes and which has the capability of charging any battery in a voltage range of from 6 to 24 volts at a charging current up to 150 amperes. It has been determined that a Chrysler Corporation, heavy duty alternator of the type commonly used on their motor vehicles meets these require-mints.
Since the alternator 11 is of a known type and does not separately comprise a part of the present invention, it is only illustrated diagrammatically in Fig. 1 with the various terminals of the alternator being shown connected to other components in the unit 10. In this regard it will be understood that the alternator 11 includes a ground terminal 13 which is common to a do output of the alternator as well as to a stators winding. Thus, the second terminal of the do output comprises a battery terminal 14 whereas the second terminal of the stators winding comprises a stators terminal 15. Field excitation for the alternator 11 is provided by means of a conventional field winding therein which is connected to a pair of field terminals 16 and 17, the terminal 16 being grounded to the same point as the terminal 13.
Field excitation current to the alternator 11~ is normally applied to the field winding (not shown) via the terminals 16 and 17. Two separate current sources are used depending upon the mode in which the unit 10 is to function.
Thus, in the event that the unit is to be operated as an arc welder having an output voltage in the range of from about 65 to 90 volts, the terminals 16 and 17 are connected directly across the vehicle's battery 20 by way of one pole of a double pole double throw function switch 21. Fig. 1 reveals that a pole 22 is connected by way of a lead 23 to an ignition switch 24 of the vehicle and that connection to the terminal 17 is made by way of a contact 25 when the switch 21 is set to its boost or welding position. The second source of current is similarly supplied by the battery 20 and is applied from a positive terminal thereof through a known voltage regulator 26 and a coupling diode 27. The regulator 26 is of a known type that is completely transistorized and which is manufactured by the Motor craft Corporation as a model "A" regulator, part No. Groucho features built-in short circuit pro-section. In this circuit configuration, current slow through the field winding of the alternator occurs via the terminals 16 and 17, and serially through the diode 27, the regulator 26 and a protective circuit breaker 28 to the positive terminal of the battery 20.
A second pole 30 of the switch 21 is selectively connectable to contacts 31 or 32 whereof which corresponds to the position of the pole 22 when connected between the contacts 29 and 25, respectively. Thus, when the switch 21 is in the boost or welding position, the connection with the contact 31 is broken so that the terminal 15 of the alternator 11 is disconnected from the regulator 26. It will be recalled that when the switch 21 is in the boost or welding position, the full battery voltage is connected across the terminals 16 and 17 causing a maximum field excitation current through the field winding. This in turn produces a maximum a voltage across the terminals 13 and 15. However, since this maximum voltage could be injurious if applied to the regulator 26, the switch 21 precludes this possibility by disconnecting the terminal 15 from the regulator 26 as described.
When the switch 21 is set to a battery charge post lion, the terminal 15 is connected via the pole 30 and the contact 31 to the regulator 26 to effect regulation of the do output voltage appearing across the terminals 13 and 14.
Concurrently, the pole 22 engages the contact 29 and energizes a field winding 32 of a solenoid switch 33. Consequently, a pair of contacts 34 and 35 close, thereby connecting the terminal 14 to the regulator 26 and through the breaker 28 to the positive terminal of the battery 20. The fully regulated output voltage from the alternator 11 is thus available to maintain the charge of the battery 20.
The regulated output voltage across the terminals 13 and 14 is also available for charging other batteries. Thus, the terminal 14, which is the positive terminal is connected to the contact 34 via a welding cable 36. A like cable 37 leads from the contact 34 to a female connector 38. Contact with the connector 38 is made via a corresponding male con-nectar 39 and therefrom another like welding cable 40 leads ~3~9 to a holder 41 which is adapted to hold either a welding rod or a clip type of connector snot shown) for connection to the positive post of a battery hot shown) to be charged.
The corresponding negative post of the battery is grounded and a spring clip issue connected via a welding cable 43 to a male connector 44 that is connectable to a corresponding female connector 45 which is also grounded.
When the switch 21 is set to its boost or welding position, it will be recalled that the do output voltage from the inductor 11 is unregulated. This mode provides, therefore, the means for generating a range of direct current voltages across the terminals 13 and 14 by controlling the running speed of the vehicle's engine. Speed control is effected by throttle control means 50 which is operably con-netted to a carburetor 49 of the engine. A diagrammatic rep-resentationof the control means 50 is seen to comprise throttle linkage 51 that is connected intermediate a rotatable control shaft 52 of a throttle valve 53 in the carburetor 49 and a vacuum diaphragm 54 that is attached to a U bracket 59 in fixed relation with the shaft 52. The linkage 51 comprises a cable 55 that is slid ably disposed within a cable sleeve 56.
One end of the cable 55 is connected to a diaphragm plate off the diaphragm 54 which is displaceable relative to thy shaft 52 such that movement of the diaphragm plate produces a Coors pounding movement in the cable 55 which is translated to rotary movement of the shaft 52. Although not shown it will be understood that a return spring on the shaft urges same to a closed condition so that the action of the diaphragm 54 will be such as to open the valve 53 thereby increasing engine speed from a predetermined low speed that is set by a linkage adjustor 60.

~326~:9 The adjustor 60 comprises a cable bushing 61 having a threaded end that is inserted through an aperture inn arm of the bracket 59 opposite the diaphragm 54 and a flanged end that is held in resiliently spaced relation with the aperture bracket arm by means of a coil spring 62 that is wrapped coccal with the long axis of the bushing 61 and which is positioned between the flanged end and the bracket.
A wing nut 63 adjusts the position of the bushing relative to the shaft 52. Since the threaded end abuts the sleeve 56, relative movement of the bushing results in movement of the sleeve 56 and corresponding rotary movement of the shaft 52.
Further rotation of the shaft 52, resulting in increased engine speed, occurs via the cable 55 under movement of the diaphragm 54.
Operation of the diaphragm 54 occurs when one side of the diaphragm communicates with a suction or reduced pressure at an intake manifold (not shown) of the engine. Reference to Fig. 1 shows such a communication path as comprising a tube 65 leading from the low pressure side of the diaphragm to a vacuum valve 66 and therefrom through a second tube 67 to a connector 68 on the carburetor which communicates with the reduced pros-sure of the intake manifold. The valve 66 includes a field winding 70 which, when energized, opens the valve 66 which in turn operates the diaphragm 54.
One terminal of the winding 70 is shown connected to the switch 24 through which connection is made to the positive terminal of the battery 20. Energizing current to the winding 70 flows when the other terminal of the winding is grounded as by a local single pole single throw switch 71. The switch 71 would normally be mounted on a control panel located 1 232~Z~

in an accessible position on the vehicle. Additionally, the connectors 38 and 45 would be similarly mounted on the panel to facilitate connection to the cables 40 and 43.
Remote control of the valve 66 is achieved by means of a push button switch 72 that is mounted on the holder 41.
It will be observed that the switch 72 is connected via a two-conductor control cable 73 to a plug 74 which, in turn, is connectable to a jack 75 that is wired in parallel with the switch 71. Accordingly, the winding 70 is readily actuated by an operator to boost the output voltage from the alternator 11 as when arc welding or when connecting the holder 41 to batteries being boosted. In either of these operating modes, a do output voltage from the alternator 11 is unregulated and varies directly with engine speed. At this time the switch 33 is open to disconnect the battery 20 from the alternator 11 The unit 10 is well adapted to rapidly recharge batteries by setting the switch 21 from its normal charge position in which an output voltage range from 14.2 to 14.8 volts is obtained to the boost position in which the alter-NATO 11 output voltage varies according to engine speed to provide a voltage range of from about 6 volts at the low end to a voltage in excess of 110 volts at the high end. An appropriate setting of the throttle control means 50 will achieve a desired voltage. A voltmeter 76 monitors the do output voltage at the alternator 11 and may be used in setting the engine speed as required. In this regard, lower voltages capable of rapidly recharging any 6, 12 or 24 volt battery system may be achieved merely be setting the adjustor 60 without actuating the diaphragm 54. Should a higher voltage be required, as in welding, the diaphragm 54 may be actuated ~23;2~9 by operating the switch 72 in order to communicate the suction side of the diaphragm with the reduced pressure at the intake manifold. A momentary contact switch may be used advantageously as the switch 72 whereby the diaphragm 54 will remain actuated only for as long as pressure is apt plied to the switch to maintain the contacts thereof closed.
This feature is particularly advantageous in welding since a higher welding voltage is required only on an intermittent basis. Thus, operation of the switch 72 will increase engine speed to provide a higher voltage only for as long as same is required. Thereafter, release of the switch 72 will permit the engine speed to drop to a predetermined low setting to effect fuel conservation.
In order to power small appliances, external lighting circuits and the like, a polarized receptacle 77 is connected from ground to the terminal 14. In this application, a stable output of 110 volts would likely be required and would be achieved by actuating the diaphragm 54 using the switch 71 to operate the valve 66.
As the unit 10 is switched from one operating mode to another, excitation current flowing through the field winding may be monitored by means of an ammeter 78 which is connected between the terminal 16 and ground. Operating the switch 21 to select operating modes could result in the development of relatively high voltage transient pulses appearing across the terminals 16 and 17 of the field winding.
Since the terminal 17 is connected to the regulator 26, it is possible that the transient voltage could enter the regulator and cause damage. This possibility is obviated, however, by the diode 27 which presents a sufficiently high peak inverse

3~9 I
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I voltage rating to prevent component voltage breakdown ¦ induced by a transient voltage spike of large magnitude.
¦ It will be apparent to those skilled in the art ¦ that the embodiment heretofore described may be varied to ¦ meet particular specialized requirements without departing ¦ from the true spirit and scope of the invention disclosed.
¦ The foregoing embodiment is therefore not to be taken as ¦ indicative of the limits of the invention but rather as as an exemplary structure of the invention which is described by the claims appended hereto.

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Claims (9)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED
AS FOLLOWS:

1. A remotely controllable arc welder and combined auxiliary power unit, comprising:
an inductor alternator adapted to be rotatably driven by an internal combustion engine, the alternator having a stator winding terminal, a pair of direct current output terminals, a corresponding pair of battery terminals and a pair of field winding terminals;
throttle control means operably connected to a carburetor of the engine for controlling the running speed thereof, the throttle control means being communicable with an intake manifold of the engine and responsive to a reduced pressure thereat for increasing the engine running speed;
valve means controllably communicating the throttle control means with the manifold;
first switch means for controllably enabling and dis-abling the valve means whereby the alternator is rotatably driven through a predetermined range of engine speeds for generating a corresponding range of direct current voltages across the output terminals; and second switch means interposed between corresponding ones of at least one terminal of the pair of direct current output terminals and the pair of battery terminals, the second switch means being controllable to selectively connect together and disconnect the respective terminals.

2. A welder and combined power unit as claimed in Claim 1, further comprising:
function switch means having a first switch connectable between a source of ignition operating voltage and selected ones of, the second switch means andthe pairof field winding terminals for alternately enabling the second switch means to connect together the respective terminals, and connecting the operating voltage across the field winding terminals.

3. A welder and combined power unit as claimed in Claim 2 wherein the function switch means includes a second switch that interconnects the stator winding terminal and a corresponding terminal of a voltage regulator when the first switch enables the second switch means and disconnects the stator winding terminal when the operating voltage is connected across the field winding terminals.

4. A welder and combined power unit as claimed in Claim 3, further comprising:
a voltage regulator operably connected to the inductor alternator and to the function switch means for regulating the voltage across the output terminals.

5. A welder and combined power unit as claimed in Claim 4, further comprising a coupling diode having a high peak inverse voltage rating operably connecting the voltage regulator to a field winding of the alternator via one of the field winding terminals.

6. A welder and combined power unit as claimed in Claim 5, wherein the throttle control means comprises:
a vacuum diaphragm having a reduced pressure side that is communicable with the intake manifold, the diaphragm being displaceable relative to the carburetor in response to the reduced pressure at the manifold; and throttle linkage interconnecting the displaceable diaphragm and a rotatable shaft of a throttle valve in the carburetor, whereby displacement of the diaphragm rotates the shaft and effects a change in engine running speed.

7. A welder and combined power unit as claimed in Claim 6 wherein the valve means comprises a solenoid operated vacuum valve that is normally closed and which is openable upon energizing a field winding of the solenoid

8. A welder and combined power unit as claimed in Claim 7 wherein the first switch means comprises a local switch adapted to maintain the field winding in a fixed energized state.

9. A welder and combined power unit as claimed in Claim 8 wherein the first switch means further comprises a remote switch connected in parallel with the local switch, the remote switch having momentary contacts that maintain the field winding in a temporary energized state, the duration of which continues for as long as the momentary contacts are held closed.