USRE17949E - Method of and apparatus for percussive wbldins - Google Patents

Description

Feb. 3, 1931.

L. w. CHUBB METHOD OF AND APPARATUS FOR PERCUSSIVE WELDIN 2 Sheets-Sheet l Original Filed March 23. 1920 m T N E V I q m 0 m ATTORNEY I Feb. 3, 1931. L. w. CHUBB R--1-7,949

METHOD OF AND APPARATUS F01? PERCUSSIVE WELDING Original Filed March 23. 1920 2 Sheets-Shawl; 2

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ATTORNEY Reiuued ch. 3, 1931 UNITED STATES PATENT OFFICE LEWIS WARRINGTON CHUBIB, OF EDGEWOOD PARK, PENNSYLVANIA,- AS SIGNOB '10 WESTINGHOUSE ELECTRIC 8a MANUFACTURING ,COMPANY, A CORPORATION PENNSYLVANIA "METHOD OI AND APPARATUS FOR PERCUSSIVE WELDING Original No. 1,403,292, dated My invention relates to the method of and apparatus for welding metal bodies by means electrical energy supplemented by mechanical energy and it has, for its pri-- mary object, the provision of a method and apparatus which shall be particularly etfective when it is desired to unite or join metal sections of relatively large diameters.

In a Patent, N0. 1,066,468, issued to me July 8, 1913, is disclosed a. process and an apparatus for joining wires of relatively small diameters by employing a condenser tioned patent could be satisfactorily em-' ployed in joining wires of relatively large diameters if ,a condenser of suflicient size could be utilized. However, in order.toemploy a condenser of suflicient size to join, for example, wires one-half inch in diameter, the

. excessive bulk required in the condenser may prohibit its application. This is true, of course, of condensers as now constructed, but this difiiculty may be removed by the construction of a compact condenser having a relatively large capacity. One object of my present inventiomre sides, therefore, in providing a process which may be utilized for joining wires of relatively large diameters without the employment of apparatus of large bulk or weight.

Although the process and apparatus hereinafter described is especially suitable for joining wires or other metal bodies of relatively large diameters, it may be successfully employed in uniting Wires of comparatively small diameters. g

With these and other objects in view, my invention will be more fully described, illustr ated in the drawings, ,in the several views in the claims.

.of which corresponding numerals indicate like parts, and then particularly pointed out percussive engagement is effected J'anuary 10, 1922, Serial No. 367,999, filed March- 23, 192$. Application for reissue filed July 13, 1922. Serial No. 574,827.

In the drawings, Figure 1 is a front elevation of a machine adapted tobe employed in practicing my process for joining ,metal bodies; Fig. 2 is a side elevation of the machine shown in Fig. 1; Figs. 3 and 4 are detail views of the chuck members and adjacent parts employed in securing metal bodies in position to be welded together; Fig. 5 is a diagrammatic view of electrical apparatus, circuits and connections which may be employed in practicing my process, and Fig. 6 is a reproduction of atypical oscillogram which illustrates the electrical conditions which obtain when a plurality of metal bodies'are percussively welded together.

- In practising my. invention, I may join a plurality of metal bodies, such as metal studs to plates, or metal conductors or wires to each other, by securing the wires in a suitable machine, the chuck members of which are connected to a secondary winding of a transformer or to a reactan'ce device. The wires are maintained in; engagement and the primary winding of the transformer or the reactance device is connected to a source of 7 direct current to establish a magnetic, field which links with the secondary winding.

The primary circuit may then be opened, 7 which causes the magneticfield to collapse and induce a current in the secondary circuit which includes the wires to be joined. During the discharge of energy, caused by the collapse of the magnetic field, the wires are separated, causing an arc to be drawn therebetween, and percussive engagement is then effected. between the wires. Although all of the steps of the process are extremely rapid, there is a certain distinct sequence of events. For example, a discharge of electrical energy is efiected through the wires which are maintained in engagement. The wires are then separated to establish an' arm, and wet the surface to be joined and, finally, a between the surfaces to be joined. In the process of percussively joining metal bodies disclosed in the patent above mentioned, a condenser is discharged through the metal bodies and the discharge is efl'ected by providing the wires with chiseled ends, 10

which,-upon engagement, closethe circuit containing the condenser, thereby producing its discharge at the instant'the wires are percussively engaged. No previous'preparation of the wires is necessary in my present process because the-ends may either be substantially flat or have roughened surfaces, This is a distinct advantage whenit is desired to join surfaces of from to inch in diameter. By maintaining the wires in engagement until the discharge is started,

an arc may be readily drawn between the ends of the wires, which causes their surfaces to be melted to a slight depth and facilitates the joining of them when they are percussively engaged. The necessar Jappa- I ratus for practising my process may e relatively-compact because a suflicient amount of electrical energy may be obtained from a transformer, or reactance deviceof ordinary capacity to join wires of relatively large diameters. y

In Figs. 1 and 2 is shown a machine, which is constructed in accordance with my inven tion, comprising a supporting base 1 having a substantially flat table member 2 upon which a plurality of guide rods 3 may be 'mounted and-from which they may be inr sulated. The rods 3 extend through openings in the member 2 and are firmly secured 'inplace by nuts 4 which are insulated, by

suitable washers, from the member 2.- The free ends of the rods 3 are maintained in proper spaced relation by a spacing member 5 which is adjustably mounted thereon. An impact member 6 has plates 7 and 8 on its upper and lower ends, respectively, which are provided with alined openings through which the rods 3 extend to maintain the member 6 in a central position between'thc rods. The member 6 is provided, at its lower end, with a reduced ,portion 9 to receive a chuck member 10 in which a wire or metal body 11 maybe secured. The plateS is provided also with threaded openlngs in which set screws 12 may be positioned to rest upon,

and be supported by, plates 13, which are, in turn, supported by springs 14 that surround the guide rods 3. The plates 13 are maintained in position by screws 15, which are loosely disposed in suitable openings therein and are secured to, and insulated from, the member 2.

It will be appreciated from the foregoing description that the member 6 is resiliently supported by the springs 14 in a position between the guide rods3 directly above the plate 2. The screws 12 are employed to adust the position of the member 6 with respect to another chuck member 16, the base of which is rigidly-mounted upon the plate' 2. The lower chuck} member, however, is' composed of relatively movable parts, the.

upper portion of which is secured to a forked rod 17 which functions was the armature of an electromagnet 18 supported upon an extension 19 of the plate 2. The rod 17 is pivotal- 1y mounted, as indicated at 20, so that another wire or metal body 21 may be secured in the chuck member 16 and be raised, by means of therod 17, to engage the wire 11. It will be apparent that, when the electromagnet 18 is energized,the rod 17 will be actuated against the action of a spring 22, secured between the rod and the extension .19, to maintain the wires in engagement when the member 6 is adjusted to a proper dis tance above the lower chuck member 16.

Another impact member 23 may also be employed, and be maintained in alinement with the lower member v6 by a guide plate 24 that is provided withopenings through which the rods 3 may be extended. The member 23 is I secured to a rod 25 in any suitable manner, as

by drilling a threaded opening into the member and screwing the end of the threaded rod 25 into such opening, where it is maintained in position by means of a nut26. The

rod 25 is extended through anopenin in the plate 5 and is provided with an eye olt 27 at its free end, by means of which the member may be raised to an-operating position. The distance the member. is raised may be accuratelyadjusted by the adjusting device 28, which is secured to the'rod 25 by suitable set screws. The member 23 may be raised by means of the rod 25 and it may be maintained in its raised position by a latching lever 29 which is vpivotallymounted upon a supporting member 30 secured to the plate 5. The lever 29 also functions as the armature of an electromagnet 31, which is also carried by the supporting member 30.

When the member 23 is raised, the lever 29 may be set to engage the adjusting device 28 and then may be maintained in such en- TLC-3 gagement by energizing the electromagnet 31. A switch 32 is mounted upon one of the guide rods 3 and is adapted to be opened, when the member 23 is dropped, by a projecting strap 33 secured to the member. A switch is; utilized to open an electric circuit which causes the primary circuit of the transformer to be opened, as will be more fully described hereinafter. The' coupling members 34,

which are'substantially of U-shape, are shown as connecting the plate 7 and the plate 24 of the respective impact members andare only utilized to afford a ready means for raising the lower member 6 when the metaLbodies havebeen joined and it is desired to remove them from the machine.

In Figs. 3 and 4, the chuck members 10 and 16 are shown on a larger scale in order to make'clear their construction. As shown in Fig. 3, conductors or cables 35 are secured to the lower chuck member 16 which carries the body 21. It will be noticed that the body 21' rests upon the upper portion of the support or base 1 of the machine and is, therefore,

very firmly supported. The body 11 is secured within the chuck member by a suitable setscrew 36. It is necessary to insure a substantial support for the lower body against the action of the combined members 6 and 23 which are employed-to effect percussive engagement of the surfaces to be joined.

- The cables 35 com rise one side ofthesecondary circuit, and t e other side-thereof may be secured to the upper chuck member 10 by means of a screw 37 fastened thereto. As shown in the drawing, the forked end of the rod 17 is firmly secured toa portion 38 of the chuck-member 16 which fitsloosely within the base of the'chuck member and may be raised to effect an engagement of the bodies 1 and 21. 1

In Fig.4 is shown" a slight modification in whicha flat plate or disk 39 may be supwith an annular chamber for receiving the disk 39. j This illustration is made to indicate ported in the lower chuck member 16 by'employing a rod 40 having an end 41 formed that various metal bodies other than rods or wires may be joined by slightly modifying the construction of the chuck members. In this instance, for example, the disk 39 may i be the head of a valve to which a stem is to be welded or joined.

In order to facilitate an understanding of I my process, a simplified diagram of the ap- 51, which is connected to terminals of the generator 42 and has the switch'32 connected in series therewith.

Theswitch46 is adapted to engage and actuatef a switch 52 that is connected in series with the windin of the electromagnet 18 that is connected to t e terminals of the generator 42. Positive action is insured by springs 53 ,l and 54 which are connected to the switches 46 and 52, respectively. As above described, the member. 23 is maintained in a raised position by the lever 29 that is actuated by the electromagnet 31, the winding of which is connected, through a manually operable switch 55, to the generator 42.

In practicing my invention, the-bodies 11 and 21 that are to be joined, are secured in the chuck members 10 and 16 of the machine and the member 6 is so adjusted that, when the,bodies 11 and 21 are separated, an arc of suitable length may be drawn therebe tween. The member 23 is raised'to an operaends of the bodies.

tive position where it is maintained by ad justing the lever 29 and by-energizing the electromagnet 31, which may be done by closing the switch 55. The switch 32 is, of course, in closed position .and' the switch 46has its coil .51 energized, and the primary circuit is closed through the switch 46% -W=hen the switch 46 is energized, it is in closedposition which permits the spring 54 to closethe switch 52, thereby energizing the electromagnet 18 which attracts the rod or armature 17 and maintains the bodies or wires in engagement. I w

The system isnow in readiness to perform a welding operation which is the condition illustrated inthe diagram. The operation may'be accomplished by opening theswitch 55, which opens the energizing circuit for the electromagnet 31 and releases the lever 29, thereby permitting the member 23 to drop.

vThe member 23 opens the switch 32 in passing by engagement of the strap 33 withthe handle of the switch, thereby de-energizing the coil 51 of the switch 46. The switch 46, therefore, opens and not only opens the primary circuit but engages the switch 52 and .causes it to open the energizing circuit of the magnet 18. Two operationsare thusaccom-,

plished by the falling member opening the switch 32, namely, the primary circuit of the transformer is opened, and, immediately thereafter, the electromagnet 18 that main-. tains the bodies 11 and 21 in engagement is de-energized, which permits the body 21 to drop and cause-an arc to be drawn between the It'will, of course, be apparent that, when the primary circuit is opened, a'current is induced in the secondary winding 48, which traverses V the bodies 11 and 21 and, when they are separated, an arc is, therefore, drawn between them. Shortly after the-establishment ofan are between the bodies, the member 23 hits the member 6 and causes rcussive engage ment between the ends '0 the bodies. x The complete operation, after the machine has been properly set, requires only a fraction of a second to be completed but, nevertheless, I

there is a distinct sequence of events. First, the primary circuit isopened, then the bodies are separted to draw an are between them and finally, percussive engagement of' the bodies is effected. .The forgingor joining of the bodies takes place while the induced current in the secondary-circuit is of'sufii'cient value to cause an application of intense heat at the surfaces to be oined. Furthermore, the percussive engagement so supplements the action of the-electrical energy as to insure a perfect joint between the bodies whether they be of like or of unlike metals. I

Although I have shown a direct-current generator as a source of energy to supply-the actance device, any suitable source of direct 05 netic m constructed as to afford the movement between the surfaces to be joined, in order to "establish an arc-therebetween at the critical instant. In Fig. 6, the copy of the oscillograms, here shown, gives a clear understanding of the electrical conditions that exist during the process of joining a plurality of metal bodies accordance with my invention. The varicurves have been tabulated in order to clearly illustrate their meaning. The broken e A indicates the point at which the switch is opened, and the broken line B indicates complete opening of the primary circuit. Aneappreciable lapse of time, of course, occurs between the point of starting to open the primary circuit and the point at which it is completely opened. The broken line C in- .dicates the point at which the secondary cirsuit is opened by the separation of the bodies, which is caused'by de-energizing the electro-' magnet 18. The broken line whlch is marked Forge indicates the point at which the falling member 23 causes percussive engagement as of the ends of the bodies. The various points of interest on the curves have been marked to indicate. the value of voltage, current and 1 power in the secondary circuit.

' indicated in Fig. 6, thetotal lapse of time between the start of opening the primary circuit tothe time of Forge is only one tenth of a second and it will be appreciated, therefore, that the total operation is exceed:

' ingly rapid. I However, the above process has roved to be exceptionally eflicient in joining.

P 45 wires of relatively large diameter and I have .found that wires so joined are so intimately united that, when, for 7 example, copper is joined to steel and the wires'are separated at substantially the point of union, a portion of the copperis foundto be inseparably connectedtothesteel. 3- i Although I have shown anddescribed an i electrical qstem and apparatus embodied 55 therein which is suitable for practising the process of joining inetal bodies, it willbe obv1- ous that my invention is not restricted to any particular apparatus or electrical system and comprehen'ds .any such process for oining to metal bodies that falls the scope of the 'appendedclaims. 1 'The term electromagnetic discharge, employed ment of the surfaces to'be welded.

that comprises effecting an electrical dis- .causing an arc to be drawn and percussive enin the claims, is intended to mean a 1 dischar e ofeIectrical energy from a magwhere the energy has been stored.

This is to distinguish from an electrostatic discharge. 1 The electromagnetic discharge may, of course, be obtained by means of other electrical apparatus than a transformer or a transformer of the particular 'type illustrated.

I claim as my invention:

1. A method of welding metallic objects that comprises storing electrical energy in a magnetic field, initiating an electrical discharge from said magnetically stored energy through the objects and immediately thereafter effecting percussive engagement of the surfaces to be Welded.

2. A method of welding metallic objects that comprises maintaining the surfaces of the objects to be welded in engagement, eifecting a discharge of electrical energy through the objects to lie-welded, separating their engaging surfaces and caus ngpercussive engagcment of the surfaces.

3. A method of welding metallic objects that comp'risesmaintaining the surfaces of the objects to be Welded in engagement, storing electrical energy in a magnetic field, discharging the stored energy through the objects tobe Welded and efiecting a separation and percussive engagement of the sur faces to be welded during the discharge of the electrical energy through the objects.

4. A method of welding metallic objects that comprises maintaining the surfaces of the objects to be welded in engagement, storing electrical energy in a magnetic'ficld, discharging the stored energy through the objects to be welded, drawing an are between the objects and effecting percussive engage- "5, A method of welding metallic objects charge 0 energy through the objects and gageme'nt between the surfaces thereof durmg the period ofenergy discharge.

6. A method .of ,welding metallic objects that comprises connecting one-of a plurality of inductively related windings to a plurality of objects to be welded, establishing, a mag netic field which links with the turns of the winding connected to the objects, effecting the collapse of the magnetic field to induce a current in the winding connected to the objects,

separating the surfacesjto be welded and effecting percussive engagement of the sur- 7 faces.

.7. A method of welding metallic objects that comprises connecting a. secondary wind- "ing of a transformerto a plurality of objects v to be welded,.maintainingthe objects in eu' gagement, causing a direct currentto traverse a primary winding of the transformer, opening the primary circuit, separating the ob'ects and effecting percussive engagement 0 the surfaces to be welded.

the other of said windings to the parts to be welded. I

. 9. An electric welding apparatus comprismg means for efl'ecting percussive engagement of the surfacesto be welded, said means including a plurality of impact members mounted to move together to produce an impact one of which-carries one of the parts to be welded and a plurality of inductively related windings, one of which has terminals by which it is adapted to be electrically energized, and the other of which is electrically connected to the parts to be welded.

10. An electric welding apparatus comprising a plurality of impact members, means for ing a base member, resilient means for sup:

supporting a plurality of bodies to be welded, means for effecting a discharge of electrical energy through the bodies and means for producing a coaction of the impact members to efiect percussive engagement of the surfaces to be welded.

. 11. An electric welding apparatus comprising a base member, resilient means'for supporting an impact member upon the base member, means for supportinga plurality of bodies to be welded, a second impact member, means for supporting the second impact member in an aligned position above the first and means for effecting an electrical discharge of energy through the bodies to be welded.

12. An electric welding apparatus comprisporting an impact member upon the base member, means for supporting a plurality of bodies to be welded, a second impact member which is of less weight than-the first impact member, means for supporting the second impact member in an aligned position above the rst and means for effecting an electrical discharge of energy through the bodies to be welded.

. 13. An electric welding apparatus'comprising a base member, resilient means for supporting an impact member upon the base member, means for supporting a plurality of bodies to be welded, a' second impact member, electrically controlled means for supporting i the second impact member in an'aligned position above the first and means for eifecting an electrical discharge of energy through the bodies to be welded.

14. An electric welding apparatus comprising a base member, resilient means for supporting an impact member upon the base member, means for supportinga plurality of bodies to be welded, electrically controlled means for maintaining the bodies in engagev trolled means for supporting the second impact member in an aligned position above the first and means for efiecting an electrical discharge of energy through the bodies to be welded. a p y l' 15. The combination with a pair of clamping terminals for. parts to be welded and means for effecting a percussive engagement of said parts, of a source 'of direct-current electrical energy and a plurality of inductively related windings, one of which is connected to the source of energy and the other of which is connected to the parts to be welded.

16. The combinationwith a pair ofclamping terminals for parts to be welded and means for'eifecting a percussive engagement of said parts, of a source of direct-current electrical energy and a transformer having its primary winding connected to the source fecting percussive engagement of the surfaces the bodies in engagement and means vfor efto be welded, of means fore effecting a discharge of electrical energy between the surfaces to be welded.

19. The combination with a. pair of clamping terminals for metal bodies to welded, electrically controlled means for mamta mng the bodies in engagement and" means for effecting percussive engagement of the, surfaces to be'welded, of means for efiectmg a discharge of electrical energy between the surfaces to be welded, said means in'clnding a plurality of inductivelyrelated windings.

. 20. The combination with a sourceof electrical energy and a plurality of inductively related'windings, one of which is connected to .said source, of a machine having a pair of clamping terminals connected to the other winding, one of said terminals being movable and the other having relatively movable parts, electrically controlled means for actuating the movable partsof the clamping terminal and means for rapidly moving the movable terminal to effect percussive engagement of bodies secured insaid terminals.

1 21. The combination-with a machine for welding metal bodies having a plurality of clamping terminals for holding said bodies in alinement, ,of electrically controlled means for maintaining the surface to be 22. An electric welding apparatus com-:

prising means for holding said parts in contact, means for obtaining a circuit through the parts to be welded, means inherently 4 magnetic means, means for releasing said operable immediately thereafter for separating the same and thus initiating an arc therebetween and means inherently operable immediately after the initiation of saidare to bring the parts together with a percussive impact. 2

23. An electric welding apparatus comprising means for obtaining a circuit through the parts tobe welded, electromagnetic means for holding said parts in contact, means for separating the same and thus initiating an arc therebetween and means inherently. operable'immediately after the initiation of said are to bring the'parts together with a percussive impact. 7 r

24. An electric welding apparatus comprising means for obtaining a circuit through the parts to be welded, electromagnetic means for holding said parts-in contact, a spring opposing the action of said electroelectromagnetic holding-means and thus initiating an arc betweensaid parts and means inherently operable "immediately after the initiation of said are to bring the parts together with a percussive impact.

25. 'An electric welding apparatus comprising an actuating member, meansfor obtaining a circuit through the parts to be welded, means for starting said actuating member, means actuated by said actuating member for initiating an are between the parts to be welded and means operative immediately thereafter for bringing the parts together with a percussive impact.

26. An electric welding apparatus comprising an actuating member, a locking device therefor, means for releasing the locking device, means for obtaining a circuit 7 through the parts to be welded, means actuated by said actuating member for initiating an are between the parts to be welded and meansv operative immediately thereafter for bringing the parts together with a percussive impact.

27. An electric welding apparatus comprising an actuating member, a locking device therefor, electromagnetic means for releasing the same, means for obtaining a circuit "through the parts to be welded, means .actuatedby said actuating member for initiating an are between the parts to be welded and means operative immediately thereafter for bringing the parts together with a percussive impact.'

28. Apparatus for electrically welding a metallic piece to a metallic body comprising means for mounting the metallic piece for movement in a predetermined path, means for moving one of said metallic members away from the other in the'line of said path to cause an electric arc to be formed therebetween, means for subsequently causing saidmetallie piece to be movedinto contact with said metallic body through the path of said arc, and means for causing said are to be maintained automatically. for a determined period.

29. Apparatus for electrically welding a metallic piece to a metallic body comprising means for mounting the metallic piece for movement in a predetermined path, means for moving one of said metallic members away from the other in the line of said path to' comprising means. for causing .the establishment of an electric circuit through said members to obtain ajwelding current, means for effecting aiphysical bodily separation of said members to strike an electric arc therebetween, electrically controlled means for maintaining the arc and welding current for a suitable time interval, electrically controlled means operating subsequently to the striking of the are but before the termination of the aforesaid time interval for moving one of said members through the ath of the-arc into c011- tact with the other 0 said members so as to efiect the welding of said members to each other.

In testimony whereof, I have hereunto subscribed my name this 5th da of July, 1922.

LEWIS WARRINGT N CHUBB.

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