US918921A - Welding apparatus. - Google Patents

Description

W. SIEBENMORGEN. WELDING APPARATUS.

APPLICATION FILED FEB. 2s, 1907.

91 8,921 Patented Apr. 20, 1909.

' To all 'whom 'it may concern: l

UNITED STATES4 WILLIAM sIEBENMOEGEn'oF WESTFIELD, N'Ew JERSEY, AssIGNOR COMPANY, A CORPORATION OF NEW JERSEY.

PATENT OFFICE.

To .a C ELECTRIC WELDING annm'a'rus.

. Specicaftion ofLetters Patent.

Application le'dFebruary 23, 1907. Serial No. 358,8112.

B e it known thatoI, WILLIAM SIEBENMOR- GEN' a citizen-,of the UnitedStates, residing at estfield, New Jersey, have invented certain new and useful Improvements .in Welding Apparatus, of `which the following is a clear, full, and exact description.

My invention relates toan ap aratus which is useful in electric welding, suc for example as fusing the edges of two metal parts to` gether'.' V Y Heretofore electric welding has been accomplished by drawing an arc between acarbon terminal and theobject to be welded, the heat of the arc fusing the metal `,parts together; In. carrying out thisl operation a voltagegreatly -in excess Vof that needed for the maintenance of the larc has been used with 'a resistance in series to prevent too great rushpof current at time of making con-,- tact. The great waste of power in the above method is apparent. .In my invention .'I prefer to use a pressure not exceeding. that of the voltage across the terminals when ythe arc is drawn to its working length, andto provide means for automatically controlling the voltage between the terminals.

My `invention will be set forth in the claims. 'Intthe drawings whichv show a preferred form of my invention; Figure 1 represents a' diagram of connections, and Fig. 2 a detail of an alternative construction. l

1, 2, `re resents an electric transformer,

vwhich yin t 1e present case is a direct-current mot`or-generator- The motor 1 1s connected to suitable mains 3 and 4 constituting the primary circuit, and the generator 2 is rotated by the motor, as is common in such rota transformers. The generator 2 is in' this ,case the source of electro-motive force for the arcmg or secondary circuit.

5 and 6 are two electric terminals between which the arc is adapted to be drawn, 5 representing in thisgcase two metal ipe's which are to be welded together at t e joint .7. The terminal is preferably a freely movable carbon point provided with a suitable insulated handle 8, so that the workman. may

move it by hand, as desired. In order to v reduce the voltage across the terminals to prevent a too great iiow ofcurnent-when the terminals are in contact, Ipreerably provlde a resistance in the circuit. 9is auch afresist` to the arcing terminals, and is vpreferably ohmic and Aof such an amount as will prevent a too great rush of current when the o erator brings the terminal 6 in contact wlth the work, j ust previous to drawing the arc, which he does b'y moving the terminal 'away to such a' distance as will .draw the arc to the desired'lengthf as indicated, for example, by

fthe dotted lines at .101' It will be obvious that, as the two terminals are moved apart, the resistance of the circuit will increase on account of the s ace necessary to be bridged by such arc, an vit is therefore desirable to automatically v`raise the voltage across said terminals to maintain the arc as the terminals are separated in'drawing the arc, -and,'when a starting resistance is used, tocut out some or all of such resistance in order to compensate for such increase of resistance (by the arc) in the circuit, and in the drawings I have provided means for automatically varying said resistance 9 substantially inversely proportionally to the resistance of said arc, that 1s, to the increase'in resistance between the two arcing terminals while said arc is playing between them. This I preferably accomplishby providi a switch for automatic ally cutting out saId line resistance as the resistanceof said arc-rises. as a consequence of the gradual removal of the movable terminal from the .work In the construction illusf trated in Fig. 1,I such a switch is indicated at 11, and it willbe obvious that whensuch switch is raised so as to brid e the stationary contacts 12 andl3, lthe res1stance9 will be substantially removed from the ,'circuit be.

cause of the short-circuitformed around it by .Wire .14 and switch lever 15.- The switch 'lever 15 is in this case a hand-operated lever which may be moved so that more or, less of saidresistancelayill be cut out by switch 11. In order to control the time of Operation of such switch 11I preferably provide .a normallyS-oen shunt 16, 17, around the arcing termina s .witha' solenoid 18 therein of high resistance, which solenoid ma many turns'of fine wire, as will e evident to any one skilled in the art.

consist of In order to control the closing of the shunt switch 2,2 I have provided means controlled 'by the current .-.in the main arcing circuit, ywhich :may be another solenoid 19 of rela- :tively low resistaneecompared with that of solenoid 18.. I ance in themaincincuiufromthegenerator,

20 ,andj 21 are springs for yretracting I the switch arms 11 and 22 when the solenoids are denergized or the current through them drops to a predetermined amount. Such springs, solenoid 19, and switch 22, are there` l'ore one embodiment of a means for auto- .matica'lly restoring the circuit to normal condition on the rupture of said arc.

.lt will be obvious that when the workman desires to draw the arc, he needs merely to bring the terminal 6 in contact with the Work, which will cause currentl to `pass through the solenoid 19 and raise the switch lever 22, thus bridging the contacts 23 and 24, and, as the movable terminal leaves the work, an arc -will be formed between them,- the resistance 9 preventing a too great rush of current. As

the terminal 6 is moved farther away, the

resistanceof the arc, that is, the resistance l to the current passing between said two teramount.

The solenoid 19 is obviousl one form of a construction which is controlled by the current in the main circuit to automatically close the shunt circuit when the resistance between'the arc terminals drops to a predetermined amount`-such, for example, as when the two terminals are brought' into contacte-and will permit spring 20 to open the same when the arc is ruptured. Such rupture of the shunt circuit will also cause the resistance 9 to be inserted in the mainv circuit, because the shunt solenoid 18 will be dcnergized, and the s rings 2() and 21 will open both switches, tlius restoring the parts to their normal condition.

l While I have, in Figxl, shown a construction in which the whole of the starting resistance 9 is cut out simultaneously it may be desirable to cut said resistance out gradually, and in Fig. 2 I have shown an alternative construction in which the pivoted switch arm 25 is connected to the core of the shunt solenoid 2,6 by a bell crank lever 27 and link 28, so that as the current in said solenoid rises it will gradually move the switch arm to the left, thus gradually cutting out the starting resistance 9 instead of cutting the same out as a whole. Such alternative construction in Fig. 2 would obviously also It will be observed that in both igures ofi'V the drawA the volte across the terminals is automatically raised to maintain the arc as the resistance resulting from drawing the arc rises. In Fig. 1 this is accomplished when the switch 11 closes, thus cutting out the resistance 9 all at once, and in Fig'. 2 when the current operates the solenoid 26. By such expression I do not mean to Vconine myself to necessarily cutting out all the line resistance at once as this may obviously not Vbe necessary, and in fact it may be in some cases more desirable to cut it out gradually, as illustrated in Fig. 2. It will also be observed that the resistance switch is automatically controlled by the variation (preferably both the increase and decrease) in resistance of the arc and is ,adapted to similarly vary the voltage across the arcin terminals so as to maintain the arc in splte of such varlatlon inresistance of the arc.

I have used in practice a generator 2 which generates a current of from 450 to 600 am eres at volts pressure, and the solenoi l18 was wound to operate when the voltage across the arcing terminalswas substantially 50. It will be obvious that no deinite amount of turns of resistance in the solenoids 18 and 19 need be given for a clear Vunderstanding of the invention by an electrician, as it-will be obvious that'the solenoid 18 may, in the construction shown in the drawings, be merely wound to such a resistance as will, after the arc is ruptured, cut down the current sufficiently to deenergize solenoid 19.

31 is a movable hand switch for cutting out more or less of the turns of solenoid 13, as may be desired.

As a means of protecting both circuits, particularly the primary, from an abnormal rush of current, I have provided a circuit controller in such 'secondary circuit, which, in the resent instance, is a circuit breaker 29, and) I control this by the current in the primary circuit by, preferably, a solenoid 30 m said primary circuit. watts used bythe dynamo exceed a certain amount, there will obviously occur an abnormal rush of current in the primary or motor circuit, which would energize the solenoid 30 sufficiently to operate the circuit breaker, said solenoid being obviously wound to operate only in case of such overl load. The switch-.brush 29 is carried on a hand lever 32, and spring 33 is provided to open the switch when the retaining lever is released upon energizing the solenoid 30.

While in the foregoing I have shown and described one means of carrying out my in- In case the total vention, I do not limit myself to such construction, as it will be obvious that many changes may be made from the construction herein illustrated without departing from m invention as claimed.

hat I claim is:

1. In a welding apparatus in combination a circuit comprising a source of electromotive force and two terminals one of which is movable and manually operable and 'between which an arc is ada ted to be drawn, means in said circuit be ore said terminals are brou ht into contact which, when said ter` mina s are brought into contact, operates to prevent a too reat flow of current across said terminals, an a circuit controller adapted to automatically raise the voltage across said terminals to maintain the arc as the arc resistance lrises through the separation of said terminals.

2. In awelding apparatus in combination, a circuitl comprising a source of electromotive force and two terminals one of which is movable and manually operable and between which an arc is adapted to be drawn, means in' said circuit before said terminals are brou ht intocontact which, when said termina s are brought-into contact, operates to prevent a ,too reat ilowof current across said terminals, an a circuit controller adapted to vautomatically raise the voltage across .said terminals to maintain the arc as the arc rel sistance rises through the separation of said terminals, and means to automatically restore said circuit to its original conditionfon `the rupture of'said` arc. 3 0

3. In-a'n'electric welding apparatus, a circ uit comprising a source' of electro-motive force and two terminals o ne of which is movable and manually o erable and between ance normally in said circuit before said terminals are brought-into contact and adapted to revent a too great rush of current .when

sai terminals contact, and means controlled by the-,current for automatically Avarying saidA resistance substantially inversely propor.

tionally to the resistance of said arc.

4. In an electric welding apparatus, a 'circuit comprising a source of electro-motive force and two terminals one of which is inovjA l operable and between -whichan arc is a aptedto be drawn, a reable and 'manuali sistance normally 4in said circuit, ari-'d n'ieans for 'automatically cutting out 'said resistance as the resistance ofsaid arc rises.

4 cuit vcoinprising; asource of electra-motive force vand two terminals one of which is movf force .an

5., AIn an electric weldingappar'atus, aicir sistance in said circuit, means for automatic-l ally cutting outsaid resistance as the resistance of said arc riseshand means for automatically reincluding said resistance in the circuit on the rupture of said are. 4

l 6. In an electric welding apparatus, a circuit com rising a source of electro-motive dp two relatively movable terminals between which anarc is adapted to be drawn, a resistance in said circuit, a shunt around said arc, and means for automatically cuttin out said resistance as the current in sai shunt rises.

7. In an electric welding apparatus, a circuit comprising a source of electro-motive force and two relatively movable terminals between which anarc is `adapted to be drawn, a resistance' in said circuit, a shunt varound said arc, means for automaticallycuttin out said resistance as the current in said s unt rises, and means adapted to automatically open' said shunt and re-insert said resistance means controlled byl the current in'said arcing circuit to automatically close said switch when the resistance between said terminals `drops to a predetermined amount and open the. same when said: arc is ruptured, and means for automatically cutting out said ohmic resistance as the resistance of said'arc rises., l j

1 #9, In yan electric welding ap aratus, a circuit com rising .a sourcel of e cetro-motive between which anl arc is adapted to be drawn a resistancelin said circuit, a shunt aroundsaid arc vand automatic means for ly Adecreasing said resistance as the current in said shunt rises. n

. lSigned at Garwood N. J. vthis 20th day of February 1 907.4 Vl'ILLIM`v SIEBENMQRGEN. Witnesses :t i

` J. C. RUNYoN,

' ABTHUii DEsPiEs.

force ,an two relatively movable terminals

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