US1181227A - Electric welding. - Google Patents

Description

O. A. KENYON.

ELECTRl-C WELDING.

APPLICATION FILED APR. 16, 1915.

1,181,227, Patented May 2,1916.

FT Ja 7- amwmp f ATTORNEY v UNITED sTAWE OFFICE I ens-A LEN KENYPN, or msrrnes-uron nunson, NEW 2031;.

. ELECTRIC WELDING.

To all whom it may concern.

Be it known that I, OTIS ALLEN KENYON,

" a citizen of the United States, residing at River'View Manor, Hastings-upon-Hudson, in the. county of Westchester and State of New York, have invented new and useful Improvements in Electric Welding, of which the following is a specification.

This invention relates to electric weld: ing, and has for its object to increase the energyeiliciency of electric arc welding.

The electrical characteristics of the are are Such that when operated from a source of constant potential itis necessary to connect a ballast resistance to regulate the current so that it will tend to remain constant. In operation, the resistance characteristics of an are areas follows :The resistance of the arc decreases with increasing current, and increases with decreasing current, therefore with constant impressed potential the arc is unstable and cannot be maintained. A constant and relatively large ballast resistance connected in series with the arc'will produce a'drop of F. proportional to the current, therefore, the combination as a whole will tend toward constant current with a constant potential, because when the resistance of the arc decreases the current tends'to increase and every increase in-the current will cause a greater drop in further increase incurrent.

the ballast resistance and thus reduce the E. M. F. across the arc tending to prevent On .the other hand an increase in the resistance of the arc will tend to decrease the'current, and a decrease in current will cause. less drop through ballast resis'tanceand therefore allow an increase-in E. M. F. across the arc,

thus working against any decrease in. ourrent. The ideal condition with the above described welding circuit is approached by increasingindefinitely the generator E. M. F. and theballastresistance,'that is, the greater the ballast resistance the more stable the arc.

I Economically considered the ballast re- 1 Z 'sistance method is very undesirable because the E. M. F. consumed in the ballast resist? ance is a dead loss-and any attempt to re-' duce this loss is. a'ccompanied'by a 'corre- Specification of Letters Patent.

arc.

Another system of electric supply for welding is the constant-current system.

However it is only in limited use because- Patented May 2, 1916. Application filed A ril 16, 1915. Seria 1 No. 21,852

sponding sacrifice inthestability of the main line, the controller comprising a lowresistance, or by-pass, line and an arc line in parallel with each other and in series with the main line, and two solenoid windings, one in series with the .arc line and the other in shunt therewith, each winding adapted to control a contact bridge when current passes therethrough.

In the accompanying drawings: Figure 1 is a diagram illustrating a special relay or controller adapted to' carry out my invention. Fig. 2 is :a diagram illustrating an electric welding plant, and showing three controllers switched into the main line. Fig. 3 is a diagram illustrating an electric welding plant, having two main circuits and'showing various arrangements hereinafter described.

Preferably I use a generator that will produce a constant current that can be adjusted by means of an ordinary field rheostat for any value within the maximum limit of the machine. In Fig. 2 a generator proper G, an automatic regulator R and an exciter E are diagrammatically represented. This machine may be so designed that it will respond instantly to changes in the resist' ance of the external circuit, and maintain a practicall constant value of current at all times. owever any constant-current gencrater-may be used. r

The portable relay or controller 0 is adapted to preserve the continuity of the main circuit at all times independent of the manipulation of the are. A controller C is used. in connection with each welding arc, and is adapted to be plugged across the terminals of a switch S in the main circuit, as

shown.

When the switch S is opened the current v is simply by-passed through the controller without interrupting the continuit of the circuit, the only change being a sight increase in resistance. minal of the switch, current passes through resistance 10, Fig. 1' across bridge 11, normally closed by spring 12, through wires 13 and 14 to the minus side of the switch. The path 10, 11, 13 and 14 then forms a portion of the main circuit. When the are A is struck, current asses-from the positive terminal of the switch through the arc line 15, and are A to line 16 and series solenoid winding 17, through wires 13 and 14 to the minus side of the switch. Series winding 17 controls bridge 11 against the action of spring 12 when current passes through said winding. It will be seen that the arc line 15, A, 16, 17 is in parallel with the low-resistance path 10, 11. If the resistance in the low-resistance path is sufiicient to cover the drop of E. M. F in the series relay 17 and the contact resistance of the are A, there is no need of a special resistance 10, and in such case resistance 10 may be omitted.

-The current passing through the series winding 17 opens the bridge 11, thus inserting the arc line in series with the main line without interrupting the continuity of the circuit, and with no change in resistance exare lengthens the E. creases, and more.andmore current is shuntcept. a slight decrease first, followed by an increase as the welder draws his are. A shunt winding 18 is inserted in parallelwith the arc line. When sufiicient current passes through the winding 18, it controls bridge -19, normally maintained open by spring 20.

When a we der withdraws" from the circuit he does soby lengthenirig his arc and as the.

. F. across it ined through the windin 18 until apoint is reached where the mechanical resistance of spring20 is overcome and the contact bridge 19 is closed, then the current from the are passing through-the bridge 19, .short circuits winding 17, and allows spring. 12

to pass direct through resistance bridge 11, and wires 13, 14,and practica ly'shortcircuits the arc and causes it to drop out of the circuit without interrupting the. conto close bridge 11. This allowsthggcurrcnt T Y tinuity thereof.

From the above description it is evident that any number (if welders within the E. M. F. limit of the electric machine may connect into the circuit by trollers C, see Fig.

ob is insulated oin the ot ers; and in spe- From the positlve tor-- Therefore,

' can use ma 'tem of this kind arranged for-two,

tors is shown in Fig. .3. At station 1, one

means of these con 2, as Ion as each welding cial cases two men can weld on the same job several on account of the fact that the generator may be capable of furnishing E. M. F. enough to take care of several IarcS. Supposing the; generator were capable of, furnishing E. M. F. for say six arcs and with a liberal excess for stabilizing purposes, when operating with one are the welder would have available from nothing up to 300 volts, depending on how long, an are he drew. An arc of 150 amperes and 300 volts would produce many times more heat than is either necessary or good for welding. a controller exactly the same as used in plants where a number of arcs are in operation is necessary to cut out the are as soon' as the voltage rises to a predetermined value. In this way the arc is automatically protected from any voltage reater than said predetermined amount anf has the stability inherent to the high voltage. Also it is possible to fix definite limits to the amount of heat that can be applied by the welder in any given case independent of thenumber of welders in circuit. The current being adjusted at the enerator is automatically maintained at t e constant value, and the voltage which eachwelder be set by adjusting his articular control er as for instance by adjusting the spring 19 or the winding 18 or both.

In large installations a more flexible arrangement can be provided by using two or more generators similar to the one abovedescribed, and running two or more circuits throughout the working area. A sysgen aman could weld. with the current produced by one of the generator units,'and at stayet it.

tion 2 a man could weld with current produced by a second generator unit. At station 3 connections are shown whereby one man could weld with the sum of the currents from both the generators At station 4: connections are shown wherebyr two men can weld on the same piece, each using current from a difi'erent generator.

be current in each generator may be set at any value desiredeach independent of the other. If both enerators are set at .the same value, then t ere are two values of current always available in the 'shop, that of. one machine and double. If the machines are set at different values, there are three valuesalways available, that of each machine and the sum of the two. A perfectly flexible adjustment of the current taken b each are independent of'all 'others may he attained by an adjustable shunt 21, across the the circuit and that required at the particular controller where it is installed;

.7 The circuits may be increased to any'de sirednumber by adding more machines to the plant. An'installation of" two or-more generators, such as shown inrFig. '3, economically considered, is cheaper, in first cost than an installation of the constant-poten-' tial type capable of doing the same amount of work, and the cost .of operation of such a plant is very much less on account of the complete elimination of ballast resistance. Generators of this type may be connected in parallel and when so connected will op-.

h -erate as one machine for a constant current, independent of the value of reslstance inseries'up to the E. F. limit of the machine.

The controllers herein described have been used by me on constant-potential circuits of an arc. For instance, it is ordinary prac- I current circuits.

themain circuit suflicientlyuniform to 'pre-. vent the interference-of any. one are with any of'the others. 1

for limiting the voltage across the arc and for operatlngtwo or more arcs in series; therefore, while the. controller is especially adapted for use in-constantcurrent circuits it may also be advantageously employed on constant potential circuits of higher voltage than that required for successful operation ties to employ generators of from 60 to 7 5 volts in constant-potential welding plants, while with the controllers of the type herev described it is possible to operate'two arcs in series from the ordinary 125-volt lighting circuits, thus avoiding entirely the necessity of installing a. special welding generator. -When-'220 volts" are-available more arcs may be operated in series in the same manner.

Therefore,-it should be distinctly understood that'the controller herein described is not in any way limited to application on constant- 7 Nor do- I limit myself to the specific form of controller, which is herein set" forth only as the preferable means for accomplishing the. desired result.

' I claim as my invention:-'-

1. In el'ectric,welding, a 'main circuit, a

plurality of welding arcs adapted to be connected in series in said main "circuit, and means formaintaining the conductance of plurality ofwelding arcs adapted to be connected in series in said main circuit, means 1 others, and means for limiting the impressed volta e.

.3. 11' electric welding, a main circnit, a

.mined amount.

plurality of welding arcs adapted to be" connected in series in said main circuit, means for maintainmg the conductance of the main circuit 'sufiiclently unlform to prevent the interference of'any one are with any of the others, and automatic means for limitingthe impressed voltage.- p

at. In electric arc welding, a main line,

an arc line connected in parallel witha portion' of the main line, in combination with ,means adaptedtojopen the main line between the connections of the arc line when the arc is struck, and to close the mainline before the resistance in the arc line reaches .a predetermined amount.

- 5. In electric arc welding, a main line, an

arc line connected in parallel with a portion of the main line, in combination with means the arc is struck, and to automatically close the main line beforethe resistance in the arc line reaches a predetermined amount;

. 6. In electric arc welding','a main line, an arc line connected in parallel with a portion v of the main line, in combination with electro-responsivemeans for. opening the main line when the arc is struck, and to shunt the current from thearc line to the mainline when .the resistance an the arc line reaches a redetermined amount.

' In electric arc .vlxelding, a main line, an

arc line connected in arallel with a portion of the main line, a se res relay in the arc line adapted to open the, main line between the connections of the arc, line when the arc is struck, anda shunt relay in parallel with the arc line and ada ted to short circuit the series relay-to permit the main line to close when-the resistance in'the arc line reaches -a predetermmed amount.

'8. In electric arc welding, a main line, in combination with a. controller adapted to be switched into the main line, said controller comprising two lines. in parallel with each other and each in series with the main line, the first line in the controller being normally closed, the second including the welding arc,- and means for opening the said first line when the arc is struck and for closing thefirst line before the resistance in the 'arc line reaches a predetermined amount.

. Y 9. In electric arc welding, a main line, in combination with a controller adapted to be switched into the main line, said controller 2. In electric welding, a maincircuit, a. i

comprising a low resistance line normally closed in series with the main line, an arc line inseries with the main line, and means dependent upon current in thearc line to open the low resistance line, andmeans for shunting the current from the arc line when the resistance therein 'i eaches a predeter- 10. In electric arc welding, a main line,

a controller adapted to be switched into 4 the main line, said controller comprising a low resistance line normally closed in series with the said main line, an arc'line in series with the main lineand provided with a series relay adapted to open the low resistance line when the arc 1s struck, and a

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