US3447730A

US3447730A - Wire feed apparatus

Info

Publication number: US3447730A
Application number: US542943A
Authority: US
Inventors: Joseph C Jeannette
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc; ESAB Welding Products Inc
Priority date: 1966-04-15
Filing date: 1966-04-15
Publication date: 1969-06-03
Anticipated expiration: 1986-06-03

Description

June 3, 1969 J. c. JEANNETTE WIRE FEED APPARATUS Sheet Filed April 15, 1966 FIG. 2

FIG. 8

INVENTOR JOSEPH C. JEANNETTE June 3, 1969 J. c. JEANNETTE 3,447,730

WIRE FEED APPARATUS Filed April 15, 1966 Sheet 2 of s m "w L 4% INVENTOR JOSEPH C. JEAN/VETTE June 3, 1969 J. c. JEANNETTE WIRE FEED APPARATUS Sheet Filed April 15, 1966 FIG. 5c

FIG. 7

FIG. 5b

INVENTOR JOSEPH c JEA NNETTE United States Patent US. Cl. 226-176 9 Claims ABSTRACT OF THE DISCLOSURE A four-roll wire feed device adapted to drive wires of varying diameters. One of a pair of spring biased rolls is split perpendicular to its axis whereby variable size and/or number of spacers may be inserted to accommodate varying wire diameters.

This invention relates to apparatus for feeding wire and the like.

This invention also relates to an improved wire feed apparatus for use in an electric arc welding system. More particularly, this invention relates to a 4-roll wire feed device that can accommodate various sizes of wires without replacement of parts.

The basic 4-roll wire feed device is well known in the prior art. A typical device is described in United States Letters Patent No. 2,032,260 granted to V. J. Chapman on Feb. 25, 1936. The device is normally used to automatically advance a wire electrode in an arc welding sys tem. Heretofore, whenever a different size of electrode was to be used, the 4-roll wire feed device had to be replaced or rebuilt in order to accommodate the new electrode. This involved considerable time and expense and greatly increased the difliculties involved in on location welding. The welder would have to carry around either a multiplicity of wire feed devices or in the alternative a plurality of different sized drive rollers so that he could weld with different sized wire electrodes.

It is, therefore, an object of this invention to provide a single wire drive mechanism which will accommodate various sizes of electrodes.

Another object of the invention is to provide an improved wire drive mechanism in which the drive and the driven rollers are capable of engaging all sizes of wire electrode.

Another object of the invention is to provide an improved wire drive mechanism which will accommodate different size wire electrodes without replacement of parts.

Other objects, features and advantages will appear or be pointed out as the description proceeds.

In the drawings;

FIGURE 1 is an elevational view showing an illustrative embodiment of the invention;

FIGURE 2 is a view partly in section, partly broken away, taken on the line 22 of FIGURE 1;

FIGURE 3 shows an end elevational view of the device shown in FIGURE 1;

FIGURE 4 shows a plan view, partly in section, partly broken away, of the drive mechanism for the device;

FIGURES Sa-Sf illustrate diagrammatically an embodiment of the invention in which various pairs of spacers are used to separate the halves of the drive rollers;

FIGURE 6 illustrates diagrammatically an embodiment of the invention in which a single spacer is used to separate the halves of the drive rollers;

FIGURE 7 illustrates diagrammatically an embodiment of the invention in which the drive rollers are spring loaded so that the rollers may be forced apart to accommodate various sizes of wire electrode;

FIGURE 8 illustrates the preferred form of a spacer which is to be used in certain embodiments of the invention;

FIGURE 9 illustrates a side view of the spring assembly; and

FIGURE 10 illustrates a plan view of the spring assembly.

FIGURE 1 shows a wire feed assembly having a rear plate 1, left side plate 2 and a right side plate 3. The plates are preferably formed as part of an integral casting.

A cylindrical pin 6 is mounted in the rear plate 1 and extends forwardly therefrom. Pivotally mounted on this pin are a pair of roller brackets, designated 7, 8 respectively. A grip ring 9 locks the brackets on the pin 6. The brackets are partially channel shaped as shown in FIGURE 2 and have bifurcated extensions with circular openings to ride on the pin 6. Each of the brackets is spring loaded as shown in FIGURE 3. A leaf spring 13 is pivotally mounted on a pin 14 for substantially horizontal movement. The spring may be locked in position by means of a catch 15. The spring may be locked in either recess 17 or 18 in order to provide a degree of adjustment which will be more particularly described below. The bracket 8 is spring loaded in the same manner as bracket 7. Each catch 15 is mounted on an end plate by means of screws 16.

On the lower portion of each bracket is mounted a

20, 21 which is locked in place by means of grip rings 22, 23 which are in turn held in position by means of

screws

24, 25. Rotatably mounted on the

pins

20 and 21 are pressure rollers 27, 28 and

gears

29, 30. The pressure rollers may be smooth or serrated depending on the type of wire to be driven. The gears and rollers are preferably made from the same piece. Thrust bearings 31 and 32 are located between the roller face and the bracket and between the gear face and bracket.

The lower drive roll mechanism which cooperates with the upper pressure roller mechanism will now be described. Fixedly mounted in the rear plate at spaced locations are

pins

35, 36. The mechanism associated with only one pin will be described, it being understood that the other drive roll mechanism is of the same form. On each pin is rotatably mounted a drive roll retainer having a geared portion 41, a cylindrically shaped portion 42 and a threaded portion 43. Slidably mounted on the portion 42 is an annular spacer 45, and split

drive roll members

46, 47. The spacer and drive rol-l members are keyed 48 to the portion 42 to prevent relative rotation therebetween. An annular spacer ring 44 is placed between the

members

46 and 47 but is not keyed on 48. The relationship between the roll members and spacers will be described in detail below with reference to FIGURES 5a-7. The roll members and spacers are locked on the portion 42 by means of nut 50 which is screwed on threaded portion 43. A bushing 51 and grip ring 52 serve to lock the whole assembly on the shaft 36. As shown in FIG- URE 2 the

gears

41 and 30 are drivingly interconnected. Thus, viewing FIGURE 1, counter clockwise rotation of gear 41 results in clockwise rotation of gear 30. The other pair of gears associated with

shafts

20 and 35 are drivingly interconnected in the same manner.

The drive mechanism for the device is illustrated in FIGURE 4. An input shaft 55, which is connected to a motor or other suitable power source, is drivingly connected to shaft 61 through a gear reduction unit 56. The shaft 61 is drivingly connected to shaft 60 by means of a bevel gear unit indicated at 57. Suitable bearing means 58 support shaft 60. A gear 59 is rigidly fixed to shaft 60 and is in driving relationship with the gears 39' and 41. Thus the drive mechanism drives both pairs of cooperating rollers. The drive mechanism and associated 3 motor 60 is mounted on the rear plate 1 by means of bolts 61.

The operation of the illustrated wire feed assembly may be described as follows: A wire is thrust through the opening 65 and into the space between the pressure roller 28 and the

drive roll members

46 and 47. As shown in FIGURE 2 the drive roll members have a beveled peripheral edge on each face of the roll member. The angle a of the bevel as shown in FIGURE 5a is approximately 13. The space resulting from the bevels accommodates a wire 85 as shown in FIGURE 5a. The wire is drivingly fed through both pairs of rollers and exists through opening 66.

As illustrated in FIGURE 1, a downward force is exerted on the wire by means of pressure rollers 27, 28.

Brackets

7 and 8 are forced downwardly by means of the

springs

12 and 13. The springs are positioned in outer recesses 17 as shown in FIGURE 1. If less force is to be exerted on the wire, the springs may be located in recesses 18. This arrangement constitutes a simplified and more reliable method of applying variable forces to a wire than has heretofore been used.

The springs each comprise a .pair of substantially flat leaves 90, 91, preferably made from spring steel. The leaves are prestressed so that they assume a slightly arcuate form, as illustrated in FIGURE 9. The leaves are riveted 92 together at one end and are drilled 93 at the other end to accept the pin 14. The springs are assembled on the wire feeder so that the convex surfaces engage the

roller brackets

7, 8. Thus when wire is fed into the machine the springs are deflected upwardly and are thereby flattened out as shown in FIGURE 3. The rate of the spring must of course be selected bearing in mind the load which the wire can tolerate without being deformed. Constant rate springs are preferred. Another important feature of the spring assembly is that it is self adjusting and therefore may accommodate many wire sizes. The following charts illustrate the relationship between various wire diameters and the load on the wire when the spring is locked in recess 17 and when in recess 18. The recess 17 is usually used when hard wires are to be fed since it affords greater loads on the wire. Note that the recess 17 is slightly lower than recess 18 in bracket 15. The recess 18 is used for soft wire and for many of the cored wires.

SPRIN G IN RECESS 18 Pressure at Lead on Wire diameter (inches) spring (lbs) wire (lbs) As shown in the above charts many different wire sizes can be used in the feeder without adjusting the spring mechanism. This self adjusting feature is extremely important in that considerable time is saved when changing wires in that the spring pressure need not be reset. The self adjusting spring mechanism cooperates with the split roller mechanism which will hereinafter be more particularly described to accommodate many wire sizes.

The type of mechanism illustrated in FIGURE 1 is especially suited for use in feeding electrode wire in arc welding systems. In this type of environment the motor speed is controlled by well known systems which main- 4 tain constant arc voltage by varying the electrode feed rate.

The spacer mechanism which is an important part of the wire feed assembly will now be described in detail. Heretofore, the lower drive roll members were grooved in a peripheral sense in order to accommodate the wire. This is clearly illustrated in the Chapman patent, noted above. This type of construction has one obvious disadvantage, and that is that only one size of wire may be effectively handled therein. Attempts to feed a larger size wire will result in wire deformation and if smaller size wire is used, it will not be transmitted through the mechanism.

In the embodiment shown in FIGURE 2, a pair of spacers are utilized, one 44 located between the drive roll members and the other 45 located inwardly thereof. If the operator desires to accommodate a larger wire, he merely removes the nut 50 and rolls 46, 47 and then places the additional spacer 45 between the rolls and then he reassembles the drive mechanism, Thus there is no need to carry additional drive rollers when the use of different sizes of wire is contemplated. Spacer 45 is illustrated in FIGURE 8. The spacer 44 may be annular in form and need not be keyed to the key 48.

Another embodiment of the spacer mechanism for adjusting the

lower guide rollers

46, 47 is shown more clearly in FIGURES 5a-5f. The circumferential portion of each guide roller is beveled 73, 74 to receive the wire electrode. Pairs of different sized spacers 76410 are mounted on opposite sides of the rollers. If the operator of the device desires to change the size of the wire electrode he merely removes the nut 50 and rearranges the

rollers

46, 47 and associated spacers so that the size of wire he now wants to use may be accommodated. When pairs of spacers of equal size are used as shown in FIGURES 5a5f, the center lines of all the various sizes of wire will be in the same plane. Thus, the

rollers

46, 47 will each be moved axially the same amount and the point of contact 72 of the wire on the pressure roller 28 will always be the same. FIGURES Sb-Sj illustrate schematically the pressure rollers in different adjusted positions.

The following is a chart illustrating the relationship between spacer thickness and wire size:

Spacer thickness Wire size, =|=.003 inches Quantity inches When pairs of spacers are used the wire always exits at the same point through opening 66 and the wire will be fed along a straight path. This is an extremely important advantage in that the wire will not be deformed. If the point of contact 72 is shifted, then the wire will be bent and assume a cast since it enters opening 66 at an angle.

When single spacers of various sizes are used as shown in FIGURES 2 and 6 the point of contact 72 will shift and one roller will remain fixed relative to the other.

A further modification is schematically illustrated in FIGURE 7. In this modification springs are used to replace the spacers. Helical springs 86, 81 are positioned between bac-

king plates

82, 83 and the

rollers

46, 47.

The

rollers

46, 47 can move axially against the spring pressure to accommodate various sizes of wire electrode. The spring loaded embodiment has definite advantages in that it is not necessary to remove the nut 50 and then rearrange the rollers. The operator merely thrusts the wire through the inlet fitting 65 and into the grooved area between the rollers at which time the rollers will separate and adapt to the size of the wire. When the

springs

86, 81 are of equal force the point of contact 72 will remain the same for all sizes of wire. Various types of springs may be employed for this purpose. For example, wave type springs or the Belleville type are suitable due to their size, shape and strength. The wave bent type was found especially suited for small sizes of wire.

Initially the feasibility of using split drive rollers was tested on a workbench set up in which the pressure rollers were forced downwardly by means of weighted devices. The weights were of course known and therefore the pressures required to feed various sizes of wire could be determined. Excessive pressures cannot be tolerated in this type of feeder due to the resulting wire deformation. Furthermore, this device must often be used to feed cored wire which can only accept medium compressive forces. The results of these tests showed that the split roller technique did not necessitate the use of excessive compressive forces to feed the wire and that soft wire and cored wire could be fed without deformation.

The apparatus described above is especially suited for use in an arc welding system but can of course be used in any type of wire feeding system.

While illustrative forms of apparatus in accordance with the invention have been described and shown herein, it will be understood that numerous changes may be made without departing from the general principles and scope of the invention.

What is claimed is:

1. A wire feed mechanism comprising, a housing means, a plurality of roller means rotatably mounted on said housing, one of said roller means being split perpendicular to its axis of rotation, drive means drivingly connected to at least one of said roller means, said roller means being closely spaced so as to abut a wire thrust therebetween, means comprising spacers to adjust the position of said split roller means along its axis of rotation so that various sizes of wires may be accommodated in said wire feed mechanism.

2. The feed mechanism described in claim 1 in which the spacers are comprised of pairs of equal size.

3. The feed mechanism described in claim 1 in which the spacers are of differing sizes.

4. A wire feed mechanism for use with electric arc welding apparatus comprising a housing means, a pressure roller housing adjustably mounted in said housing means, a first roller rotatably mounted in said pressure roller housing, a second roller rotatably mounted on axle means in said housing means, said first and second rollers being closely spaced so as to abut a wire thrust therebetween, drive means for said rollers, transmission means interconnecting said rollers, said second roller being split along a plane perpendicular to the axis of rotation of the 6 roller, said split roller being axially adjustable along said axle means to accommodate various sizes of wire and means to maintain the position of said split roller in said adjusted positions.

5. The feed mechanism described in claim 4 in which the position maintaining means comprises pairs of spacers of equal size.

6. The feed mechanism described in claim 4 in which the position maintaining means comprises spacers of differing size.

7. The feed mechanism described in claim 4 in which the position maintaining means comprises resilient means coacting with said split roller.

8. The feed mechanism described in claim 4 in which the pressure roller housing comprises a bracket member pivotally mounted on said housing means, a spring member pivotally mounted on said housing means and engaging said bracket member, an upstanding bracket having recesses mounted to said housing means adjacent said bracket member, said spring member being capable of selective locking engagement with any of said recesses.

9. A wire feed mechanism for use with an electric arc welding apparatus comprising a housing means, a pressure roller housing movably mounted in said housing means, a first roller mounted in said pressure roller housing, a second roller mounted in said housing means in close proximity to said first so as to abut a wire thrust therebetween, drive means interconnecting said rollers, spring means mounted on said housing means forcing said first roller toward said second roller, said spring means comprising a relatively thin substantially flat spring member and is pivotally mounted on said housing means and is capable of being locked in one of a plurality of recesses in said housing means.

References Cited UNITED STATES PATENTS 1,246,863 11/ 1917 Bright-man 22'6-184 X 3,022,929 2/1962 Myers et 'al 226-185 X 3,093,285 6/1963 Leaming et al. 226-184 1,228,178 5/1917 Brooker -171 2,091,021 8/1937 Stevens 226-187 X 3,107,291 10/1963 Evans et a1. 219- 3,331,545 7/1967 Olivieri 226-187 ALLEN N. KNOWLES, Primary Examiner.

US. Cl. X.R.