US1327792A - Spot-welding apparatus - Google Patents

Description

F. THORNTON, JR.

SPOT WELDING APPARATUS.

APPLICATION FILED APR. 18. 1919.

1,327,792. Patented Jan. 13,1920.

INVENTOR Fly 3. flan/r Thor/172m, Jr:

WITNESSES:

UNIT D.

FRANK THORNTON, JR., OF MANSFIELD, OHIO, ASSIGNORTO WESTINGHOUSE ELECTRIC 8; MANUFACTURING- COMPANY, A CORPORATION OF PENNSYLVANIA.

SPOT-WELDING APPARATUS.

Application filed April 18, 1919.

To all whom it may concern:

Be it known that I, FRANK THORNTON, Jr., a citizen of the United States, and I a resident of Mansfield, in the county of Richland and State of'Ohio, have invented a new and useful Improvement in Spot-Welding Apparatus, of which the following is a specification.

My invention relates to apparatus for.

spot welding and it has, for its primary object, the provision of apparatus of the above designated character which shall be relatively light in weight and compact of structure.

Another object of my invention is to provide spot-welding apparatus which shall permit of the employment of electric current to obtain both the necessary compressive force upon the objects being welded .and the heating effect to fuse the objects at the point where it is desired to unite them.

A still further object of my invention is to provide spot-welding apparatus which may be adjusted by skilled workmen and thereafter operated, with a high degree of efficiency, by unskilled workmen.

With these and other objects in view, my invention will be more fully described, illustrated in the drawings, in the several views of which corresponding numerals indicate lik parts, and then particularly pointed out in the claims.

In the drawings, Figure 1 is a diagrammatic view of spot-welding apparatus and electric control circuits therefor which embody my invention; Fig. 2 is a side View, on a larger scale, of a switch mechanism employed in the apparatus shown in Fig. 1, and Fig. 3 is a sectional view taken substantially along the line IIIII'I of Fig. 2.

In practising my invention, I may employ apparatus, suchas shown in Fig. 1, which comprises a base member 1 upon which may be secured, by any suitable means, such as nuts and bolts 2, a plurality of supporting members 3 and 4, the supporting members being preferably insulated from each other,

- as indicated at 5. The member 3 may be provided, at one end, with a removable clamping member 6 adapted to secure an electrode member 7 to th member 3. The other supporting member 4 ay be provided with substantially parallel arms 8 so spaced as to permit of supporting an electrical coil '9 upon the lower arm. The electric coil 9 Specification of Letters Patent.

Patented Jan.13, ieao.

Serial no. 290,941.

. is preferably formed with a somewhat restricted portion 11 at its lower end which may function as an electrode and may also have another restricted portion 12 at its other 'end. The armature 10 may be positioned within the coil 9 by disposing the electrode 11 in a suitable opening provided in the lower arm 8, and the restricted portion 12 may be extended through a similar alined opening in the upper arm 8, the armature being held in its uppermost position by a spring 13 surrounding the end portion 12 and secured in such position by a nut 14-.

A switch mechanism 15, which may be operated by the coil 9, by means of its armature 10, comprises a lever 16, carrying a switch blade. 16, at one end, and may be connected, at its other end, to the upper end of the portion 12 of the armature 10 and may be insulated therefrom. The lever 16 may be pivoted, as indicated at 17, and may be connected to a retarding device 18. A. suitably supported resilient contact member 19 is adapted to cooperate with the switch blade 16.

The switch mechanism 15is best shown in Figs. 1 and 2. The switch blade 16 may comprise a metallic plate 20 and a hon-con ducting plate 21 and may be mounted upon the lever 16 at an angle thereto. Electrical contact is made between resilient member 19 v The coil 9 may be connected across "supply mains 22 byleads 28 and 24 which may be provided with a suit-ableswitch 25 for opening and closing the circuit of the coil 9. The amount of energy supplied to the coil 9 from the mains 22 may be regulated by a suitable rheostat 26. The switch blade 16 and member 19 of the switch mechanism may be connected in parallel with the coil 9 by a lead 27 which may be connected to the member 16 and to one side of the circuit, as indicated at 29, and by a lead 28 whichmay be connected to the member .19 through a coil 30 of a relay switch 31 and to the other side of the coil circuit, as indicated at the junction point 31.

A heating clrcuit may be provided by employing a transformer 32 having a primary winding 33, provided with voltage-control taps, which may be automatically connected in series with the supply mains 22 by the relay switch 31 through contacts 34:, 35, 36

and 37. A secondary winding 38 of the transformer 32 may be connected, at one side, to the supporting member 4: and at the other, to the supporting member 3,1in any suitable manner. A secondary circuit is thus provided which includes the electrode members 7 and 11, the electrode member 11 being connected to the supporting member 4 by a flexible lead 39.

lln welding a plurality of metallic members together, the members may be disposed upon the stationary electrode member 7, and the circuit be closed, through the switch 25, to energize the coil 9, the degree of energy being regulated by the rheostat 26. When the coil 9 is energized, the armature is drawn 1 into the coil, thus compressing the spring 13 and causing the electrode 11 to compressively engage the members to be welded.

,The lever 16 is actuated by the movement of the armature 10 to cause the switch blade 16 to engage the resilient member 19. As

' before stated, electrical contact is made upon the up-stroke of'the switch blade 16', thereby closing a circuit through the coil 30 of the relay switch 31 which, therefore, automatically connects the primary winding 33 of the transformer 32 to the supply mains 22. In accordance with the well known transformer action, an electromotive force is induced in the secondary winding 38 of the transformer which causes a current to.

flow through the electrodes 7 and 11 and the interposed work which cooperate to form a closed circuit.- c

The metalliemembers engaged by the electrodes are heated, on account of contact re- 1 sistance, and theheated metal is united by the compressive-force produced by the .electrodes. The degree of compression may be regulated, if desired, by adjusting the rheostat 26 which controls the energy supplied to the coil 9. Furthermore, the length of time to which the members being welded are subjected to the heating effect of the current from the transformer may be varied by adjusting the retarding device 18 of the switch mechanism 15. The welding current is supplied while the switch blade 16 is in contact wlth the resilient member 19 on its up-stroke, the circuit being broken when the switch blade 16 passes the resilient member 19. 1 The lever arm 16 is held in its upper position until the circuit energizing the to. the electric coil 9 may then -magnetic means for forcing electric coil ada coil 9 is broken, the spring 13 being then permitted to raise the armature 10 and conse quently to lower the lever arm 16.

Although I have described apparatus that is adapted for spot welding, it is obvious that minor changes may be made i-n'the construction thereof and in the electric control therefor, and l desire that no limitations shall be imposed except such as are indicated in the appended claims.

I claim as my invention:

1. A spot-Welding apparatus comprising. a plurality of electrode members, electromagnetic means for forcing the members into engagement with interposed work, and an automatically actuated circuit-closer for closing a'heating circuit including the electrode members. I

V 2. A spot-welding apparatus comprising a plurality of electrodemembers, electromagnetic means for forcing the members into engagement with interposed work, means for automatically connecting the electrode members in a heating circuit, and means for automatically disconnecting the electrode membersfrom the heating circuit.

3. A spot-welding apparatus comprising a plurality of electrode members, electrothe members into engagement with lHlZ'Z-BIdPOSP/d work,

means for automatically conne ting the electrode members in a heating circuit, and.

means for automatically disconnecting the eledtrode members from the heating circuit at a predetermined time.

4. A spot-welding apparatus comprising ,a stationary and a movable electrode, an

electric coil adapted to force the movable electrode toward thel stationary electrode when it is energized, means for automatically connecting the electrodes in a heating circuit, and means for automatically disconnecting the electrodes from the heating circuit at a predetermined time.

7 5. A spot-welding apparatus comprising a stationary and a movable electrode, an v ted to force the movable electrode towar the, stationary electrode when it is energized, :rneans for varying the energy supplied to the coil, means tending to maintain the electrodes in. spaced relation,

means for automatically connecting the electrodes in a heating circuit, and means for automatically disconnecting the electrodes from the circuit at a predetermined time.-

In testimony whereof'I have hereunto subscribed my name this 31st day of March,

- FRANK THORNTON, JR.

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