US3717744A

US3717744A - Electrode holder

Info

Publication number: US3717744A
Application number: US00155785A
Authority: US
Inventors: P Pishioneri
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-23
Filing date: 1971-06-23
Publication date: 1973-02-20
Anticipated expiration: 1990-02-20

Abstract

An electrode holder having jaws which are spring-urged together and carry electrode grippers directly connected to a power cable, the spring pressure on the jaws being adjustable and the grippers being easily changeable. The conductive parts of the holder are contained within exterior members made of insulating material and including jaw covers, insulated jaw opening levers, and an insulated sleeve rotatable to change the spring force closing the jaws. The exterior members are shaped to protect the moving parts of the holder from flying molten metal, and a cable connector is located inside for the purpose of facilitating the assembly of the holder to a power cable.

Description

United States Patent [191 Pishioneri Feb. 20, 1973 ELECTRODE HOLDER [76] Inventor: Philip J. Pishioneri, 321 Third j' 'ff 'g i' gg g $818 an xammer c u zman Street Ellwood Clty 16117 AttorneyArthur E. Dowell, Jr. et al. [22] Filed: June 23, 1971 21 Appl. No.: 155,785 [57] ABSTRACT An electrode holder having jaws which are spring- 52 urged together and carry electrode grippers directly E fi 3 "219/ connected to a power cable, the spring pressure on the jaws being adjustable and the grippers being easily [58] new of Search 219/138 changeable. The conductive parts of the holder are 19/143 contained within exterior members made of insulating 56 material and including jaw covers, insulated jaw open- 1 References Cited ing levers, and an insulated sleeve rotatable to change UNITED STATES PATENTS the spring force closing the jaws. The exterior members are shaped to protect the moving parts of the 2,186,158 1/1940 Weeks ..2l9/l38 holder from flying molten metal, and a cable connec- 2,145,699 1/1939 Townsend 1 tor is located inside for the purpose of facilitating the gemafd 6t 3| 5 assembly of the holder to a power cable. ourque 2,472,177 6/1949 Taber ..2l9/138 5 Claims, 7 Drawing Figures l- 4. 36 l a. 2 5 I2 37 4 42 34 5e 5/ 5a 54 55 56 4 5 M2 22 a so 5 t, 1 a: 5|

PATENTED FEBZ 01975 7 SHEET 2 BF 2 Mam dw m

type commonly used in electric welding, and more particularly relates to improvements in jaw-type holders in which the grip is adjustable and the paths for conduction of current to the electrode have been improved.

Electrode holders of the general type to which the invention is directed are usually connected to a high current source by a heavy electric cable and the main purpose of the holder, aside from physically supporting the electrode, is to conduct the current into the electrode with minimal resistive power loss. Therefore, it is a principal object of this invention to provide an electrode holder in which both electrode gripping jaws are connected directly to the cable carrying the working amperage, as distinguished from coupling the cable only to one jaw or coupling it to some other structural member of the holder which is in turn connected to a jaw. It is important to connect the welding cable directly to both jaws in view of the fact that in electrode holders where current is coupled only to one of the jaws, the point of contact of that jaw with the electrode carries an overload of current and tends to overheat and oxidize so that resistance is introduced at the point of contact, thereby not only losing conductivity but also tending to eat away the metal unnecessarily.

It is another major object of the invention to provide an electrode holder having a spring-biased jaw assembly capable of gripping electrodes of various sizes, and having means for adjusting the spring pressure tending to close the jaws so that the pressure can be correctly adjusted regardless of the size of the electrode being gripped. 7

Another very important object of the present invention is to provide, in combination, an electrode holder in which the cable is connected directly to both jaw members which are spring biased in the closing direction, andin which the spring bias can be adjusted by turning a member which is free to rotate with respect both to the cable and to the jaws. This is an important object because it is desirable to be able to adjust the spring bias without having to move the cables which are relatively heavy and not easily manipulated, and because it is undesirable to have to rotate the jaws or the electrode held by them during such adjustments.

Another important object of the invention is to provide an electrode holder which can easily be manipulated by a person wearing welding gloves, the jaws being opened against the spring bias force by pinching together two diametrically opposed lever members.

Still another important object of the present invention is to provide a jaw-type electrode holder in which all of the moving parts are substantially covered and protected from metal flying through the air during welding so that the pivot and spring adjustment mechanisms are not contaminated by flying metal, which otherwise has a tendency to render them. inoperative.

A further object of the invention is to provide an electrode holder having a cable connector conveniently located therewithin, and normally covered and protected by a portion of the body of the electrode holder, theconnector permitting the electrode holder to be quickly and conveniently removed from the cable using simple hand tools.

Still a further important object of the invention is to provide an electrode holder of the type in which the cable is connected directly to both jaw assemblies, and these jaw assemblies include electrode gripper plates which can be easily disassembled therefrom and changed when they are worn. These gripper plates are preferably diamond knurled.

Other objects and advantages of the invention will become apparent during the following discussion of the drawings, wherein:

FIG. 1 is a perspective view of an electrode holder according to the invention;

FIG. 2 is an enlarged elevation view of the electrode holder;

FIG. 3 is a view similar to FIG. 2, but shown in longitudinal cross-section;

FIG. 4 is a section taken along line 44 of FIG. 3;

FIG. 5 is a section taken along line 5-5 of FIG. 3;

FIG. 6 is a section view taken along line 66 of FIG. 3; and

FIG. 7 is a partial exploded view showing mechanism for pivotally mounting the jaw members and for adjusting the spring tension tending to urge them toward closed position.

Referring now to the drawings, FIGS. 1 and 2 show an electrode holder according to the present invention including a pair of opposed jaws at the forward end and a body portion including an axially disposed adjustment sleeve and a pair of pinch levers by which the jaws can be opened, all attached to the cable C for carrying high current into the jaws. One feature of the present invention is that substantially all exposed members are insulated, whereby if the electrode holder touches a metal object. conductively connected to the power source short circuiting of the latter will be prevented.

Turning now to a more detailed description of the invention, FIG. 3 shows a cross-section of the electrode holder including a pair of

conductive jaw members

12 and 14 which can also be seen in the exploded view of FIG. 7. The jaw members are channel shaped and are designed to engage a jaw supporting member 20 which has a hollow bore 22 extending therethrough to receive wire conductors as will presently be discussed. The support member 20 lies upon the axis A, FIG. 7, of the holder and has forwardly extending pin-receiving portions 24 which receive a pivot pin 26 which passes through holes 111 and 13 in the

interchangeable jaws

12 and 14 and through holes 25 in the jaw supporting members 20. The pivot pin 26 is covered by an asbestos sleeve as can be seen in FIGS. 3 and 7. Each of the jaws has a shoulder such as the shoulder 15 of the jaw member 12 and the shoulder 16 of the jaw member 14, these shoulders being laterally offset from the axis A and from the pivot pin 26 when the members are assembled.

A spring means including a coiled spring 28 and a washer 29 surrounds a threaded rearwardly extending portion 21 of the jaw support member 20, and the rear end of the spring 28 abuts the forward end of a bushing 30, the bushing having an internally threaded bore 31 which screws onto the threads 21 of the jaw support member 20 so as to confine the spring means between the

shoulders

15 and 16 and the bushing 30. The bushing 30 is fixed within an insulating sleeve 34 which surrounds the cable C, and is of reduced diameter near its rearward end.

As can best be seen in FIG. 3, a pair of

pinch levers

36 and 38 are respectively attached to the

jaws

12 and 14 by

screws

37 and 39. These levers are made of insulating material and have skirt portions 36a and 38a, FIG. 2 which at least partially surround and conceal the spring assembly and the forward part of the sleeve 34 which adjusts it. The

members

36 and 38 are identical interchangeable parts and the wider skirt portion 38a overlaps the narrower skirt portion 36a on the opposite member.

The

lever members

36 and 38 end partway along the

jaws

12 and 14, but the remaining portions of the jaws are protected from contact on their outside surface by insulating

covers

42 and 44 which wrap almost completely around the jaws, covering their forward ends and the portions of their surfaces not protected by the forward ends of the

insulated levers

36 and 38. The covers .42 and 44, as can be seen more clearly in FIGS. and 6 include

side portions

43 and 45 which extend rearwardly beyond the pivot and overlie the outer surfaces of the opposite covers so as to prevent accidental electrical contact therewith. The

covers

42 and 44 are also identical interchangeable parts which are secured in place on the jaws by the

screws

46 and 47 which are countersunk below the surface of each cover to prevent their touching any outside metallic objects during normal use.

The electrical current is conducted to the jaws l2 and 14 by bifurcated conductor legs which are respectively labeled 48 and 49 as shown in FIG. 3 and in FIG. 5, and these legs are covered by asbestos boots. The bifurcated

cable members

48 and 49 end in flattened connection members 48a and 49a which are uninsulated and have their strands held together inside copper tubes slid thereover, shaped to rectangular cross-section and drilled to provide clearance for the

screws

37, 39, 46, and 47. These screws extend through the flattened end portions 48a and 49a as shown in FIG. 6 and are screwed into

grippers

50 and 51 having tapped holes therein and having knurled electrode gripper surfaces 52 as shown in FIG. 7. The knurled portions also clearly show in FIGS. 1, 2 and 3 and are visible between the

covers

42 and 44.

The flattened areas 48a and 49a of the

conductors

48 and 49 can comprise separated strands of the main cable C, but in the preferred form of the present invention they are separate conductors which pass into a cable connector 54 as can best be seen in FIGS. 3 and 4. The cable connector 54 has a bore at each end, one end receiving the main power cable C and the other end receiving the bifurcated

conductors

48 and 49. A small shoe plate 55 overlies the

conductors

48 and 49 and is clamped tightly thereagainst by set screws 56, and at the other end of the connector 54 there is another metal shoe 57 which overlies the stripped end of the main cable C and is tightly clamped thereagainst by set screws 58. The manner of manipulation for the purpose of assembling and disassembling the connector 54 from the main cable will be presently discussed.

In use, the present electrode holder can have its jaws opened to separate the

gripper plates

50 and 51 by squeezing the

levers

36 and 38 together so as to rock the jaws l2 and 14 open about the pivot pin 26. An electrode can then be inserted between the jaws, and the levers released in order to allow the jaws to be clamped shut by the pressure of the spring 28 transmitted through the washer 29 pressing axially against the

shoulders

15 and 16. The pressure of the jaws on the electrode is adjusted by rotating the insulating sleeve 34 so as to turn the bushing 30 on the threaded rear portion 21 of the jaw support member 20, thereby changing the spacing between the bushing 30 and the

shoulders

15 and 16 to adjust the spring compression. If it becomes desirable to remove an electrode holder from the main cable C, this can be done quite easily by unscrewing the sleeve 34 to back the bushing 30 off of the threaded section 21 and away from the jaw support member 20 to expose the connector 54. The set screws 58, or for that matter the set screws 56, can be easily reached so that they can be loosened or tightened, thereby to remove or replace the connector 54 on the

conductor members

48 and 49 or on the main cable C. When the cable connector 54 is again made up, it is an easy matter to screw the bushing 30 back onto the threads 21 and thereby recompress the spring 28 against the washer 29.

The present structure results an electrode holder in which all metal parts are concealed against accidental short circuiting with other conductive objects, and in which the metal parts can be easily reached so that they can be changed, or disassembled for servicing. It is important to notice that the jaw members can be easily disassembled from the

grippers

50 and 51 without disturbing the cable conductors, so that the grippers can be changed as often as desired, either to change gripper shape or else to replace them when they become worn.

The present invention is not to be limited to the exact form shown in the drawings, for obviously changes may be made therein within the scope of the following claims.

I claim:

1. A holder to be attached to the end of a currentcarrying cable to support an electrode in current-conductive relationship with respect thereto, comprising:

a. a hollow jaw support member disposed along the longitudinal axis of the holder and having a pivot disposed transversely thereof;

b. a pair of jaws each rotatably supported on the pivot of said support member and extending axially of the holder therebeyond to comprise the electrode-holding end of the holder, the jaws each having a shoulder offset from said axis near the pivot and both shoulders lying in a common transverse plane;

c. sleeve means disposed along said axis and threaded onto the jaw support member adjacent to the shoulders of the jaws and comprising the cablereceiving end of the holder;

. spring means inside the sleeve means and compressed between said shoulders and an abutment within said sleeve means, the latter means being rotatable on said threaded jaw support member to adjust the spring force applied axially to said shoulders to urge each of the jaws toward the other;

e. the cable having conductor means extending through said sleeve means and through said hollow jaw support member and the conductor means being bifurcated therewithin in the vicinity of the pivot and having separate legs extending and attached to the respective jaws; and

f. means on both jaws operative to open them when pinched toward each other.

2. In a holder as set forth in claim 1, said sleeve means having an exterior surface of insulating material; and said jaws having covers of insulating material intermeshing with each other and extending axially of the holder to cover the jaws in one direction and to cover the pivot in the other direction.

3. In a holder as set forth in claim 2, said jaw-opening means comprising lever means attached to each jaw and extending divergently therefrom beyond said pivot and toward said cable-receiving end of the holder and operative to open the jaws when pinched toward each other, the lever means each comprising a channel of insulating material shaped to partially surround the sleeve means and to substantially conceal said spring means.

4. In a holder as set forth in claim 1, means for attaching the conductor legs to the jaws comprising a pair of electrode gripper plates disposed opposite each other between the jaws, the conductor legs each extending between a jaw and its associated gripper plate; and screw means transfixing the respective jaws and their gripper plates at locations remote from electrodecontacting areas of the gripper plates and compressing the conductor legs therebetween.

5. In a holder as set forth in claim 1, said conductor means extending from an axial location within said sleeve means to said jaws; and a cable connector within said sleeve means and receiving said current carrying cable and joining it to said conductor means, said connector being accessible when the sleeve means is unscrewed from the jaw support means.

Claims

1. A holder to be attached to the end of a current-carrying cable to support an electrode in current-conductive relationship with respect thereto, comprising: a. a hollow jaw support member disposed along the longitudinal axis of the holder and having a pivot disposed transversely thereof; b. a pair of jaws each rotatably supported on the pivot of said support member and extending axially of the holder therebeyond to comprise the electrode-holding end of the holder, the jaws each having a shoulder offset from said axis near the pivot and both shoulders lying in a common transverse plane; c. sleeve means disposed along said axis and threaded onto the jaw support member adjacent to the shoulders of the jaws and comprising the cable-receiving end of the holder; d. spring means inside the sleeve means and compressed between said shoulders and an abutment within said sleeve means, the latter means being rotatable on said threaded jaw support member to adjust the spring force applied axially to said shoulders to urge each of the jaws toward the other; e. the cable having conductor means extending through said sleeve means and through said hollow jaw support member and the conductor means being bifurcated therewithin in the vicinity of the pivot and having separate legs extending and attached to the respective jaws; and f. means on both jaws operative to open them when pinched toward each other.

4. In a holder as set forth in claim 1, means for attaching the conductor legs to the jaws comprising a pair of electrode gripper plates disposed opposite each other between the jaws, the conductor legs each extending between a jaw and its associated gripper plate; and screw means transfixing the respective jaws and their gripper plates at locations remote from electrode-contacting areas of the gripper plates and compressing the conductor legs therebetween.