US2835086A - Oscillating wheel dresser for resistance type welders - Google Patents

Description

May 20, 1958 G. L. LONGMIRE ET AL 2,835,086

OSCILLATING WHEEL DRESSER F OR RESISTANCE TYPE WELDERS Filed Nov. 4, 1954 2 Sheets-Sheet 1 Fig. I J6 n4 Fig. 2 4

in INVENT RS GORDON L. LONGMI E BENJAMIN E. BAILEY mum; y MARTIN s. SCHLEGEL umr SOURCE OF COMPRESSED AIR V W & 16

y 0, 1958 e. L. LONGMIRE ET AL 2,835,086

OSCILLATING WHEEL DRESSER FOR RESISTANCE TYPE WELDERS Filed Nov. 4, 1954 2 Sheets-Sheet 2 V A 98 22 56 56 Q ,8 1% w 26 24 I06 1% 'fia r I v V 60 J wk I 72 Fig.5 86 22 9Q JNVENTORS GORDON L.LONGMIRE BENJAMIN E. BAILEY y MARTIN s. SCHLEGEL a2 84 96 Mani-0X United States Patent OSCILLATING'WHEEL DRESSER FOR RESISTANCE TYPE WELDERS Gordon L. L0ngmire, El Cajon, and Benjamin E. Bailey and Martin S. Schlegel, San Diego, Calif.

Application November 4, 1954, Serial No. 466,758

3 Claims. (Cl. 51-241) The present invention relates generally to, electrical resistance welders and more particularly to a cleaning device for rotary welding electrodes.

The primary object of this invention is to provide a cleaning device which is mounted on the structure of an electrical resistance welder and cleans the rotary electrode while the welder is in operation.

Another object of this invention is to provide a cleaning device having an automatic oscillating shoe which carries a strip of abrasive material over the weldingv contact surface of the electrode with a scrubbing action for maximum cleaning effect.

Another object of this invention is to provide a cleaning device which operates effectively regardless of the rotation'of the electrode, whether continuous or intermittent.

Another object of this i'nventionis to provide a clean ing device which will maintain a given cross sectional shape on the periphery of the electrode and thus will not atfect the efiiciency of the welding contact surface.

Another object of this invention is to provide a cleaning device in which the abrasive used for cleaning is stored on a roll attached to the device and is easily advanced as each portion of the paper becomes worn.

Another object of this invention is to provide an electrode cleaner wherein the pressure of the abrasive cleaner on the electrode is easily andaccurately gauged.

Another objectof this invention is to provide a cleaning device of simple construction which is adaptable to many types of resistance welders.

Finally, it is an object to provide a cleaning device of the aforementioned character which is simple, safe and convenient to operate, and which will give generally efficient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as willbe hereinafter fully described in the specification, particularly pointed out in the claims, and illustrated in the drawings which form a material partjof. this disclosure and wherein similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings, and in which:

Fig. 1 is a front elevation view. of the device, with a roll of abrasive material and with portions of a welder being shown in dot-dash line for illustrative purposes.

Fig. 2 is a top plan view ofthe device, the roll of abrasive material being removed for clarity.

Fig. 3 is a side elevation view thereof, the roll of abrasive material being removed for clarity.

Fig. 4 is an enlarged fragmentary sectional view taken on the line 44 of Fig. 1.

Fig. 5 is a sectional view taken on the line 55 of Fig. 4.

Fig. 6 is an enlarged fragmentary sectional view taken on the line 6-6 of Fig. 1.

Fig. 7 is a diagram of the fluid pressure actuation system used to oscillate the cleaning shoe.

Referring now to the drawings in detail, the cleaning device includes a rigid frame 10 which is fixed to the electrode carrier or ram 12 of a welding machine by suitable bolts 14. The ram 12 carries a rotatable wheel or electrode 16, the rim of which constitutes the contact surface for the welding operation, the ram being power operated to hold the electrode firmly on the material being welded.

Mounted on the frame 10, for sliding movement in a radial direction relative to the electrode16, is a guide block 18 on which is pivotally supported a pair of rocker arms 20. Riding against the lower end of the guide block 18 is an arcuate shoe 22 shaped to fit the periphery of the electrode 16, said guide block being pivotally connected to the lower ends of the rocker arms 20. Attached to the upper ends of the rocker arms 20 is a clevis 24 which is carried on the piston rod 26 of an oscillating cylinder 28 mounted on the frame 10. Fixed to the frame 10 is a support arm 30 carrying a shaft 32 on which is retained an abrasive storage roll 34. The strip of abrasive, such as emery cloth or paper, from the roll 34 is passed beneath the shoe 22, so as to be in contact with the electrode 16, and is held at both ends of said shoe by clamps 36.

The frame 10 comprises an upper plate 38 from which is suspended a horizontal mounting plate 40 secured by rigid gussets 42 and 44. Depending from the upper plate 38 is an upright stay 46 which, together with said upper plate, is bolted firmly to the ram 12 by the bolts 14. The mounting plate extends to one side of the ram 12 and has at its end a downwardly extending, fixed end plate 48 to which is secured a bracket 50. The mounting plate 40 and end plate 48 are firmly braced by stilfeners 52 and 54. The frame structure 10 is secured together by welding or the like for simplicity.

The guide block 18 is slidably mounted on a pair of spaced guide pins 56 fixed at their upper ends in the mounting plate 40 and extending downwardly into'guide bores 58 in said block. The guide block 18 has'a socket 60 between the guide bores 58 to receive the lower end: of an adjustment screw 62 threaded through the mounting plate 40. At the lower end of the adjustment screw 62 within the socket 60 is a compression spring 64 to bias the guide block 18 downwardly, said adjustment screw being provided with a lock nut 66.

The rocker arms 20 are mounted on opposite sidesof the guide block 18 on a rocker shaft '68 which is journalled in ball bearings 70, or the like, recessed into said guide block and spaced by a sleeve 72. The upper ends of the rocker arms 26 have outwardly extending pins 74 fixed therein which are journalled in bearings 76 in the ends of the clevis 24. The oscillating cylinder 28, which actuates the rocker arms 20, is pivotally mounted. on the bracket 50. The lower ends of the rocker arms 20 have notches 78 which engage with pins 80 fixed in the shoe 22 and extending laterally therefrom.

The shoe 22 is an arcuate block having its under surface 82 shaped to fit the periphery of the electrode 16. This under surface 82 is also shown as being concaveiir cross section, although the actual shape is dependent: on the particular type of electrode to be cleaned. The shoe is fitted with a resilient pad 84 secured to the under surface 82. The upper surface of the shoe 22 has a central guide rail 86 which rides in a groove 88 in the lower end of the guide block 18, the portions of the Shoe on either side of said guide rail constituting arcuate bearing surfaces 90 which are in sliding contact with the correspondingly arcuate lower surface of the guide block.

The support arm 30 is fixed to the mounting plate 40 f3 and extends angularly upwardly therefrom, the shaft 32 being fixed to the upper end of said arm. The shaft 32 has a wing nut 92 threaded thereon and is provided with a washer 94 to retain the abrasive roll 34 in place.

The abrasive strip 96, unwound from the roll 34, passes beneath the shoe 22 and is held against the electrode 16 by the pad 84, as shown in Fig. 5. At each end of the shoe 22 is a clamp 36 comprising a generally U- shaped yoke 98 fixed to the shoe and having an end bar 100 which is spaced from the end of the shoe, as in Fig. 6. Between the shoe 22 and the end bar 100 is a clamp bar 102 having therein a pin 104 which extends through end bar and is slidable therein. Fixed to the sides of the end bar 100 are spaced brackets 106, between which is pivotally mounted an eccentric cam 103 having an extended lever 110. The cam 108 engages the pin 104 so that, when the cam is rotated, the clamp bar 102 is forced toward the corresponding end of the shoe 22 to grip the abrasive strip 96 passed therebetween.

To operate the device the oscillating cylinder 23 is connected to a source of compressed air or the like through a timing unit 112, as shown in Fig. 7. This timing unit 112 automatically reverses the airflow to cause the piston rod 26 to reciprocate, the structure and functioning of such a unit being well known to those skilled in the art. Thus when the cylinder 28 is actuated, the piston rod 26 is reciprocated, rocking the rocker arms 20 on their shaft 68 and oscillating the shoe 22 in an arcuate path over a portion of the periphery of the electrode 16. The abrasive strip 96 clamped to the shoe 22 is thus made to rub against the electrode 16 removing foreign matter picked up during the welding process. in this manner the electrode 16 is maintained in a clean condition and is capable of more efiicient operation, the intimate contact of the periphery of the electrode against the surface of the work being essential for effective welding.

In order to dispose of the foreign substances removed from the electrode 16, a suction nozzle 114 is used, the nozzle shown having a slot 116 to receive the electrode. As shown in Fig. 2, the nozzle 114 straddles the electrode 16 so that suction is applied effectively thereto, the clamp 36 being omitted from this figure for clarity. The nozzle 114 is supported by an arm 113 bolted to a por tion of the ram 12, said nozzle, of course, being connected to a suitable vacuum source by a hose 120. Various types of suction devices may be used, that shown being illustrative.

When the portion of the abrasive strip 96 in use becomes worn, the clamps 36 are released and a fresh length of abrasive is advanced from the roll 34. The pressure of the abrasive strip on the electrode 16 is controlled by the adjustment screw 62, which is locked by the lock nut 66 when the correct setting has been found.

Various types of existing cleaners for welding electrodes use sanding belts driven by a rotary mechanism, or grinding wheels which cause excessive wear on the electrodes. Further, the sanding belt type necessitates replacement of the entire belt at frequent intervals. The present invention utilizes a highly efiicient scrubbing action of the abrasive with controllable pressure and facilitates the easy replacement of abrasive from the conveniently mounted storage roll.

The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawing and the above recited objects. It

4 will be obvious that all said objects are amply achieved by this invention.

Further description would appear to be unnecessary.

It is understood that minor variation from the forms of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

We claim:

1. A cleaning device for a rotary welding electrode in a welding machine, comprising: a frame having attachment means; a guide block mounted on said frame for rectilinear sliding motion; a shoe having an arcuate face; means biasing said guide block toward the center of curvature of said arc; rocker arms pivotally mounted on said guide block and pivotally connected to said shoe; an oscillating mechanism mounted on said frame and operatively connected to said rocker arms to oscillate said shoe; a support extending from said frame; a storage roll to abrasive strip mounted on said support; a resilient pad fixed to said face; the end portion of said abrasive strip being disposed superficially on said pad; and clamps fixed to said shoe to retain said abrasive strip.

2. A cleaning device for a rotary welding machine comprising: a frame having attachment means; a guide block mounted on said frame and slidable in one plane; a spring biasing said guide block in one direction; an arcuate shoe slidably mounted on said guide block for motion in an arcuate path; rocker arms pivotally mounted on said guide block and pivotally connected to said shoe; an oscillating mechanism operatively connected to said rocker arms to oscillate said shoe in said arcuate path; an abrasive strip on said shoe; and clamps fixed to said shoe for removably securing said abrasive strip to the shoe.

3. A cleaning device for a rotary welding electrode in a welding machine, comprising: a frame having attachment means; a guide block mounted on said frame for rectilinear sliding motion; a shoe having on arcuate face; means biasing said guide block toward the center of curvature of said arcuate face; rocker arms pivotally mounted on said guide block and pivotally connected to said shoe, and an oscillating mechanism mounted on said frame and operatively connected to said rocker arms to oscillate said shoe in an arcuate path; means formounting a roll of abrasive strip on said frame and means for securing an end portion of the strip on said arcuate face.

References Cited in the file of this patent UNITED STATES PATENTS 761,061 Collinson May 31, 1904 1,313,702 Krieger Aug. 19, 1919 1,930,383 Capellman Oct. 10, 1933 2,242,545 Randolph May 20, 1941 2,248,353 Indge July 8, 1941 2,258,733 Brackett Oct. 14, 1941 2,450,237 Indge Sept. 28, 1948 2,467,027 Glandis Apr. 12, 1949 2,467,091 ONeill Apr. 12, 1949 2,519,351 Calvert Aug. 22, 1950 2,634,559 Carmichael Apr. 14, 1953 2,665,530 Deffenbaugh Jan. 12, 1954 FOREIGN PATENTS 610,617 Great Britain Oct. 19, 1948

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