US2283996A - Electrode holder - Google Patents

Description

May 26, 1942. s. J. IRWIN ET AL 2,283,996

ELEGTRODE HOLDER Filed May 25, 1940 e. fr 01916 5 Patented Mayv`26, 1942".

ELEc'rnonE nomma samuel James Irwin', chester, laumiinnmeui M.

Irwin, Coatesville, Pa.

Application May 25, 1940, Serial No. 337,308

(Cl. 21S- 8) 3Ciaims.

This invention relates to improvements in electrode holders of the type used in electric welding, and a principal object oi the invention is to provide a holder of this type which shall be more adequately and effectively insulated than the holders of the prior art. I

More particularly, an object of the invention is to provide a holder wherein the insulation is confined to the areas oi" the vholder which are least subject to excessiveoverheating during the welding operations, and wherein at the same time the outer terminal or electrode-holding tip of the holder will be prevented from arcing if brought into contact with a metal object unless an electrode is secured in the holder.

Still more specifically. an object of the invention is to provide a holder of the type set forth wherein the outer terminal or electrode-holding tip of the holder is disconnected from the source of current except when a welding rod or electrode is secured in the holder. l

Stili another object of the invention is to provide a holder having generally improved strucn tural and functional characteristics, including a more effective means for clamping the weldin rod or electrode in place. l

In the attached drawing: l

Figure 1 is an elevational view of a holder made in accordance with our invention:

Fig. 2 is a longitudinal section on the line 2-2, Fis. 1: 1

forms a bearing for a disk II of insulating'material which extends outwardly beyond the hancilev element I, and is confined between the end of the said element and the ilange III as illustrated.

Extending through the sleeve 2 is a metal rod I2, to'the inner endof which is attached, by meansof threads I3, a sleeve I4. The hollow end of the sleeve I4 forms a socket for reception ci' the exposed end I5 of an insulated electric cable I6 through which the electric energy is carried to the holder. -The exposed end Il of the cable is secured in the socket by soldering or by other suitable means. yThe sleeve I4 is flanged at I'I, and this flange forms a seat for a spring I8, the other end oi which is seated on a shoulder Fig. 3 is a transverse section onthe line 2 3.

2; Fis. 4 is a fragmentary view of the outer terminal end or tip of the holder illustrating a functional detail of the device, and

Fig. 5 is a reduced longitudinal sectional view illustrating a modiiication within the scope of our invention. l

With reference to the drawing, the holder therein illustrated comprises a tubular handle I of suitable insulating material, to one end of which is secured a metal sleeve 2. In the present instance, this sleeve is provided with spaced integral collars 2, 4 and I which engage the inner wall of the tubular handle` I, and the collar 4 is provided with tapped holes for reception of I9. in the handle element I, and this spring exerts a pressure tending to force the rod I2 outwardly through the sleeve 2 so that the outer spherical end 2li of the rod is lifted away from the proximate end of the sleeve 2 upon which, under circumstances hereinafter described, thesaid tip is adapted to seat. An insulating washer 2I is interposed between the sleeve I4 and the proximate end o! the sleeve 2. and this washer is dimensioned so as to aiiord clearance between the sleeve I4 and the inner end of the sleeve 2 to permit the aforedescribed'movement of the rod I2 under action oi' the spring II. It is apparent that the washer 2i constitutes a stop which limits the extent to which the rod I2 may be moved outwardly in the sleeve 2. I

Interposed between the sleeve 2 and the rod I2 is a sleeve 22 of insulatingimaterial, this sleeve being suitably secured inthe sleeve 2 and terminating well short of the outer end of the latter. It is apparent that by reason of this insulating sleeve 22 and the washer 2|, the sleeve I4 and the rod I2 are prevented from contacting 40 the sleeve 2 except when the spherical tip 2l of sc`rews l by means of which the sleeve 2 isset and the sleeve 2, and these spaces may be vented to the atmosphere by means of holes' 0 in the handle element. The collar 2 is flanged at its the said rod is seated against the outer end of the sleeve 2, as illustrated in Fig, 2. Y

vThreaded on the' outer terminal end ,of the sleeve 2 is ametalliccap 22,andthiscapispro vided towards its outer end with transverse openings 24, 24 for reception of the welding rod or electrode. The openings 24 intersect each other and pass in part through the solid end wall 2l of the cap 22, so that the electrode 2l when inserted in either of the openings 24 may have a solid seat or bearing against the said end wall 25 of the cap. If after insertion of the end of the electrode in one of the openings 24 the cap is screwed down upon the sleeve 2, the rod is outer end as indicated at Il, and this ilange t5 brought nrst into engagement with the Spherical tip 20 of the rod I2, and thereafter, if the turning of the cap is continued, the rod I2 will be forced inwardly against the pressure of the spring IB until the said. spherical tip 20 is forced solidly against its seat on the outer end of the sleeve 2. The solid engagement of the spherical tip 20 with the rod produces a highly eillcient clamping action which binds the rod solidly in position in the holder and precludes movement or accidental displacement of the rod in and from the holder.

When the rod 26 rst engages the tip 20 of the rod I2, the only access which the electrical current has to the sleeve 2 is through the walls of the vcap 23; but when the cap 23 has been screwed down on the sleeve tol an extent forcing the tip 20 intoseating engagement with the sleeve 2, there is a direct path for electrical current to the said sleeve. In other words, when lthe parts are in the relative positions shown in Fig. 2, the path for the electrical current to the electrode or rod 26 is not only directly through the rod I2 but also through the upper end of the sleeve 2 and the cap 23, so that the resistance tothe passage of current to the electrode is materially reduced and the heating of the entire terminal end of the holder correspondingly reduced. It will be noted further that the threads of the cap 23 terminate in a shoulder 21, which by engagement with the outer end of the sleeve 2 limits the extent to which the cap may be turned inwardly on the sleeve. This shoulder stop is positioned so as to preclude direct contact between the rod I2 and the cap 23. At the times therefore when no electrode is inserted in the holder, the entire outer terminal end or tip of the latter, including the sleeve 2 and the cap 23, is disconnected from the source of current, and if under these circumstances the cap 23 or the sleeve 2 should come into proximityto or in contact with a grounded metallic body, there will be no arcing or burning, so that damage both to the metal body and to the holder is prevented under these circumstances.

It will be apparent that a holder made as described above is effectively insulated both as to the operator `using the holder, and also against damage to the holder due to laccidental arcing. It will be noted further that these objects are v attained without extending the insulation eletremely simple in form is highly efilcient and is capable of maintaining the electrode solidly in place under the most adverse conditions of use.

In this latter connection, we have illustratedl in Fig. 5 a device utilizing this form o! clamp in a holder which lacks the high degree of insulation described above. Such holders are relatively inexpensive and may be used under cir- .cumstancesfwhere a holder of the fully insulated type is not essential. In this case, the tubular f insulated handle I, the metallic sleeve' 2, and the cap 23 are essentially thev same as described above. The cable IB, however, in this case is connected directly to the sleeve 2 as illustrated. The rod I2 and the associated parts are eliminated and are replaced by a spherical element 28 which seats in the outer end of the sleeve 2. When a rod 28 is inserted in the cap 23 and the latter is threaded down on the sleeve 2, the rod is engaged by the spherical element 28, and is thereby clamped solidly in the holder in the manner previously set forth.

There may be other modifications without departure from the invention.

We claim:

l. In an electrode holder, an insulated handle, a metallic tip comprising a sleeve secured in said handle, a terminal element slidably mounted in the handle and extending through said sleeve, insulating material interposed between the sleeve and said element, a spring operatively connected with said element and operative to urge said element to an advanced p'osition in which the outer extremity thereof extends beyond the end of the sleeve, and a cap on the outer end oi said sleeveembracing the projecting extremity of the terminal element, said cap having an aperture for reception of an electrode and being adjustable longitudinally of the sleeve so as to bring said electrode into forcible engagement with the spring-pressed terminal element.

2. In an electrode holder, an insulated handle,

a metallic tip comprising a sleeve secured in said handle. a terminal element slidably mounted in the handle and extending through said sleeve, said element being normally electrically disconnected from the sleeve, a'spring operatively connected with said element and urging said element longitudinally of the sleeve into an advanced position in which the extremity of said element extends beyond the end of the sleeve, said extremity being enlarged and adapted in a retracted position of said element to seat upon the end oi' the sleeve, and a cap on the outer end of said sleeve embracing said enlarged extremity of the terminal element, said cap having an aperture for reception of van electrode and being adjustable longitudinally oi' the sleeve so as to bring said electrode into forcible engagement with the spring-pressed terminal element to thereby move said element to the said retracted position wherein the said enlarged extremity is seated upon the end of the sleeve.

3. In an electrode holder, an insulated handle, a vmetallic tip comprising a sleeve secured to said handle, a terminal element mounted in the handle and extending through said sleeve, said element being normally electrically disconnected from the sleeve, an apertured cap threaded on the outer end of said sleeve and embracing the extremity of said element, said cap constituting a means for clamping an electrode` against thel said extremity o! the terminal element, and means for preventing direct contact of said cap with the terminal element.

SAMUEL JAIES IRWIN. K ENNETH M. IRWIN.

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