Quick change braking system

A braking system for a welding machine is provided. In one aspect, the braking system includes a brake surface, a spool hub shaft, a spool hub, an adjustment knob and an expandable and compressible member. The spool hub shaft is capable of engaging against the brake surface. The expandable and compressible member is provided between the spool hub and the adjustment knob to apply varying levels of force on the spool hub. The spool hub shaft has at least one tab which is capable of engaging with a recess in the adjustment knob to adjust the force applied by the member on the spool hub.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to a quick change braking system for a welding machine.

BACKGROUND

Conventional spool hub systems for welding machines include a braking system which prevents the spool of wire from overspooling inside the welding machine. These systems vary from electronic brakes to simple brake washers with a spring force applied to the brake washer.

Conventional welding machines which use spring-based brake washers have a nut which is threaded onto an end of a threaded spool hub shaft. An example of such a conventional welding machine10is shown inFIGS. 1 and 2. The spring12is between the nut14and a spool hub16mounted on the spool hub shaft18. The nut14is tightened on the spool hub shaft18to adjust the pressure of the spring12on the spool hub16which, in turn, adjusts the pressure of the spool hub16bearing against the brake washer20. Sometimes, the nut14appears to be loose to the user, and upon seeing this, the user may tighten the nut14to what they “feel” is the correct amount of torque, since the threaded connection between the nut14and the spool hub16allows an infinite range of torque adjustment (subject to the length of the thread). Sometimes, this new torque is too tight and prevents the spool hub16from spinning on the spool hub shaft18as the spool hub16is bound too tightly between the spring12and the brake washer20. Also sometimes, the user does not apply sufficient tension, which could allow the wire spool22to overspool.

SUMMARY

In one aspect, a braking system for a welding machine is provided. The braking system includes, but is not limited to, a brake surface, a spool hub shaft, a spool hub, an adjustment knob and an expandable and compressible member. The spool hub shaft is capable of engaging against the brake surface. The expandable and compressible member is provided between the spool hub and the adjustment knob to apply varying levels of force on the spool hub. The spool hub shaft has at least one tab which is capable of engaging with a recess in the adjustment knob to adjust the force applied by the member on the spool hub.

The scope of the present disclosure is defined solely by the appended claims and is not affected by the statements within this summary.

DETAILED DESCRIPTION

While the disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, specific embodiments with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that as illustrated and described herein. Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity.

FIG. 3illustrates an exemplary wire-feed welding machine30that includes a quick change braking system32for a spool hub34which is used to a mount of spool of wire22. The exemplary welding machine30includes a plurality of components disposed within a housing38, including the braking system32. In operation, a drive system40advances a wire electrode42from the housing38to a welding torch or gun44. This wire electrode42is fed from the spool of wire22disposed within the housing38. A power supply46provides operating power to a motor48of the drive system40to facilitate advancement of the wire electrode42. The wire electrode42may be advanced through a supply cable50to a contact tip within a nozzle52of the welding torch or gun44.

During a welding operation, placement of the nozzle52at a location proximate to a workpiece54allows electrical current provided by the power supply46, which is routed to the welding torch or gun44via the supply cable50, to arc from the welding torch or gun44to the workpiece54. This arcing generates a relatively large amount of heat that causes the workpiece54and/or a filler metal to transition to a molten state, thereby facilitating the weld. As will be appreciated, such filler metal may be provided by the wire electrode42or from some other source.

The braking system32allows a user to quickly change the settings without the use of tools. The braking system32provides a plurality of preset brake forces to provide the proper braking force on the spool hub34to speed up or slow the rotation of the spool hub34, and thus the spool of wire22mounted on the spool hub34. The braking system32includes a spool hub shaft56, a brake surface58, a spool hub34, a washer60, a compressible and expandable member62, an adjustment knob64, a pin66and a spool hub nut68.

The spool hub shaft56extends outwardly from a baffle70of the housing38and is non-rotatably mounted to the baffle70. The baffle70may be formed of metal or plastic, or a combination of metal and plastic. The spool hub shaft56has first and second opposite ends56a,56bbetween which first, second and third unthreaded cylindrical portions76,78,80are provided. The first portion76extends from the baffle70and is non-rotatably connected to the baffle70, the second portion78extends from the outer end of the first portion76, and the third portion80extends from the outer end of the second portion78and terminates at end56bwhich is free. The second portion78has a diameter which is less than the diameter of the first portion76such that a shoulder82is defined between the first and second portions76,78. The third portion80has a diameter which is less than the diameter of the second portion78such that a shoulder84is defined between the second and third portions78,80. The third portion80has a bore81therethrough which is perpendicular to a centerline86of the spool hub shaft56. The free end56bmay have a chamfer formed thereon.

The brake surface58may be formed from a brake washer as shown in the drawings, or may be formed from a planar surface of the baffle70of the housing38. If formed of a brake washer, the brake washer is non-rotatably mounted on the spool hub shaft56and is non-rotatably affixed to the baffle70. The brake washer may be formed of plastic or metal, or a combination of metal and plastic. As shown, the brake washer is formed from a planar base wall88having first and second sides88a,88b, a side wall90depending from the first side of88athe base wall88at the outer edge of the base wall88and which terminates in a free end90a, and a pin92which extends outwardly from the first side88aof the base wall88. The pin92extends outwardly from the base wall88a greater distance than the side wall90. A central aperture94is formed through the base wall88. The first portion76of the spool hub shaft56seats within the central aperture94and the free end90aof the side wall90abuts against the baffle70. The pin92engages within a bore96in the baffle70to prevent the brake washer from rotating relative to the baffle70.

The spool hub34is mounted on the spool hub shaft56and the first end34aabuts against the second side88bof the base wall88of the brake surface58. The spool hub34is formed of a cylindrical body98having opposite first and second ends98a,98b, an arm100which extends radially outwardly from the body98at the first end98athereof, and a flange102which extends radially outwardly from the body98proximate to the first end98a. The body98has a first unthreaded cylindrical portion104and a second threaded cylindrical portion106. The arm100extends from the flange102. A central passageway108extends through the body98and has a first section108awhich extends through the first portion104and a portion of the second portion106, and a second section108bwhich extends through the remainder of the second portion106. The first section108ahas a diameter which is less than the diameter of the second section108bsuch that a shoulder110is formed between the first and second sections108a,108b. The arm100includes a first part100awhich extends radially outwardly from the first portion104of the body98and a second part100bwhich extends perpendicularly to the first part100aand parallel to a centerline of the spool hub34; the centerline of the spool hub34aligns with the centerline84of the spool hub shaft56when the spool hub34is mounted on the spool hub shaft56as discussed herein. The second part100bextends toward the second end98bof the body98and has a length which is greater than the distance between the first end98aof the body98and the flange102. The first portion76of the spool hub shaft56seats within the first section108aof the passageway108and extends outwardly from the first end98aof the body98. The second portion78of the spool hub shaft56seats partially within the first section108aand partially within the second section108bof the passageway108. The third portion80of the spool hub shaft56seats partially within the second section108band extends outwardly from the second end98bof the body98.

The washer60is conventional having circular ring114with a central aperture116therethrough. Both sides of the ring114are planar.

The compressible and expandable member62is formed from a central section118having opposite first and second ends118a,118b, and a central passageway120therethrough. The compressible and expandable member62has a length defined between the first and second ends118a,118bwhich is less than the length of the second and third portions78,80of the spool hub shaft56. The compressible and expandable member62may be formed from a coil spring or an elastomeric member, such as a rubber block.

The spool hub shaft56extends through the central aperture116of the washer60such that the washer60surrounds the second portion78of the spool hub shaft56, and the washer60seats within the second section108bof the passageway108and against the shoulder110. The spool hub shaft56extends through the central passageway120of the compressible and expandable member62. In an expanded condition, the member62surrounds the second portion78and a part of the third portion80of the spool hub shaft56; the member62seats within the second section108bof the passageway108; the first end118aof the member62seats against the washer60and the second end118bof the member62seats against the adjustment knob64as described herein.

The adjustment knob64is formed from a body122having first and second opposite ends122a,122band a centerline124extending therethrough, an unthreaded central passageway126extending through the body along the centerline124, a counterbore128provided in the first end122aof the body122, and a plurality of mounting recesses130a,130b,132a,132b,134a,134bformed in the second end122bof the body122. The second end122bof the body122may have a counterbore136formed therein and the mounting recesses130a,130b,132a,132b,134a,134bformed in the counterbore136, or the counterbore136may be eliminated the mounting recesses130a,130b,132a,132b,134a,134bformed in the second end122bof the body122. The body122has a length L1defined between the first and second ends122a,122bwhich is less than the length of the third portion80of the spool hub shaft56such that the adjustment knob64can move along the length of the third portion80of the spool hub shaft56without falling off the spool hub shaft56.

The central passageway126has a first central portion126awhich is cylindrical, a second portion126bwhich extends radially outwardly from the centerline124of the body122, and a third portion126cwhich extends radially outwardly from the centerline124of the body122and is diametrically opposed to the second portion126b. The first central portion126ahas substantially the same diameter as the third portion80of the spool hub shaft56and has a diameter which is less than the diameter of the second portion78of the spool hub shaft56. The second and third portions126b,126care each formed from a pair of side surfaces with an end surface connecting the side surfaces. The side surfaces may be straight and the end surfaces may be curved.

The mounting recesses130a,130b,132a,132b,134a,134bextend radially outwardly from the centerline124and radially outwardly from the first central portion126aof the central passageway126. Each mounting recess130a,130b,132a,132b,134a,134bis formed of a side wall130a′,130b′,132a′,132b′,134a′,134b′ which is parallel to the centerline124of the body122, and a base wall130a″,130b″,132a″,132b″,134a″,134b″ which is perpendicular to the centerline124of the body122. The side wall130a′,130b′,132a′,132b′,134a′,134b′ is formed from a pair of side surfaces with an end surface connecting the side surfaces. The side surfaces may be straight and the end surface may be curved. Mounting recesses130a,130bare diametrically opposed from each other and form the same recess; mounting recesses132a,132bare diametrically opposed from each other and form the same recess; mounting recesses134a,134bare diametrically opposed from each other and form the same recess. The side walls130a′,130b′ of mounting recesses130a,130bhave the same length L2which is defined as the distance between the second end122bof the body122and the base wall130a″,130b″. The side walls132a′,132b′ of mounting recesses132a,132bhave the same length L3which is defined as the distance between the second end122bof the body122and the base wall132a″,132b″. The side walls134a′,134b′ of mounting recesses134a,134bhave the same length L4which is defined as the distance between the second end122bof the body122and the base wall134a″,134b″. The lengths L2, L3and L4are different from each other such that the mounting recesses130a/130b,132a/132b,134a/134bhave differing lengths. For example, length L2is greater than length L3; length L3is greater than length L4. As a result, the distance between the respective base walls130a″/130b″,132a″/132b″,134a″/134b″ and the first end122aof the body122varies from mounting recess to mounting recess.

The pin66is conventional and may be formed of a cylinder or may have other shapes. The pin66is secured into the bore81of the spool hub shaft56, for example by a press-fit, or the pin66may be integrally formed with the spool hub shaft56and the bore81eliminated. At least one end of the pin66extends radially outwardly from the spool hub shaft56to form a tab. As shown, two radially extending tabs138a,138bare provided for engaging into respective ones of the mounting recess130a,130b,132a,132b,134a,134bas described herein, however, it is to be understood that only a single tab is required.

The adjustment knob64is mounted onto the third portion80of the spool hub shaft56by passing the third portion80of the spool hub shaft56through the first central portion126aof the central passageway126and the tabs138a,138bof the pin66through the second and third portions126b,126cof the passageway126. The adjustment knob64partially seats within the second section108bof the passageway108of the spool hub34. The second end118bof the member62seats within the counterbore128such that the member62is between the adjustment knob64and the spool hub34. The third portion80of the spool hub shaft56extends outwardly from the second end122bof the body122.

To fix the position of the spool hub34relative to the brake surface58, the tabs138a,138bare seated into one pair of the mounting recesses, for example mounting recesses130a,130b. This engagement of the tabs138a,138binto the mounting recesses130a,130bsecures the adjustment knob64, the member62and the spool hub34to the spool hub shaft56and thus to the welding machine30, and causes the first end34aof the spool hub34to abut against the second end88bof the brake surface58with a predetermined amount of force.

The adjustment knob64is rotatable on the spool hub shaft56when the tabs138a,138bare not engaged within the mounting recesses130a,130b,132a,132b,134a,134b. The tabs138a,138bcan be positioned outwardly from the second122bend of the body122by pushing on the adjustment knob64to compress the member62to move the adjustment knob64toward the brake surface58such that the tabs138a,138bclear the mounting recesses130a,130b,132a,132b,134a,134b. Once the tabs138a,138bare clear, the adjustment knob64can be rotated to a new position and the tabs138a,138bengaged within a new pair of mounting recesses, for example mounting recesses132a,132b. The amount of movement of the adjustment knob64relative to the spool hub shaft56is limited by the length of the third portion80.

The spool hub nut68is used to mount the spool of wire22on the spool hub34. As is known in the art, the spool of wire22includes a core140having end flanges142a,142bextending radially outwardly from the ends of the core140and a central unthreaded passageway144through the core140. The wire is wound onto the core140and held between the two flanges142a,142b. A bore (not shown) is provided in at least one of the flanges, for example flange142a.

The spool hub nut68is formed from a body having first and second ends and a central threaded passageway146therethrough. The threads in the passageway146mates with the threads on the second portion106of the spool hub34.

In use, the spool hub nut68is removed from the spool hub34and the spool of wire22is mounted onto the spool hub34by passing the spool hub34through the passageway144of the spool of wire22until the flange142aabuts against the flange102on the spool hub34. The second part100bof the arm100engages into the bore in the flange142a. As a result, the rotational position of the spool of wire22is fixed relative to the spool hub nut68. At a least a part of the threaded portion106of the spool hub34extends outwardly from the spool of wire22. The spool hub nut68is then threadedly engaged with the threaded portion106of the spool hub34until the spool hub nut68engages with the flange142bof the spool of wire22. The spool of wire22is then trapped between the spool hub34and the spool hub nut68.

The spool of wire22and the spool hub34are rotated during use of the welding machine30to feed wire to the welding components of the welding machine30. As the spool hub34rotates, the engagement between the spool hub34and the brake surface58provides a braking action on the rotation.

The level of braking can be changed by rotating the adjustment knob64to different positions and placing the tabs138a,138binto the different pairs of mounting recesses130a,130b,132a,132b,134a,134b, which thus changes the compression force exerted on the spool hub34by the member62, and thus the spool of wire22, by the brake surface58. When the tabs138a,138bare placed in mounting recesses134a,134b, the member62is slightly compressed between the adjustment knob64and the spool hub34and pushes the spool hub34into engagement with the brake surface58. This results in a first predetermined level of pressure exerted by the member62on the spool hub34, which pushes the spool hub34against the brake surface58with this first predetermined level of pressure. When the tabs138a,138bare placed in mounting recesses132a,132b, the member62is more compressed between the adjustment knob64and the spool hub34than when the tabs138a,138bare in mounting recesses134a,134bas a result of length L3being greater than length L4. This results in a second predetermined level of pressure exerted by the member62on the spool hub34, which pushes the spool hub34against the brake surface58with this second predetermined level of pressure. When the tabs138a,138bare placed in mounting recesses130a,130b, the member62is even further compressed between the adjustment knob64and the spool hub34than when the tabs138a,138bare in mounting recesses132a,132b. This results in a third predetermined level of pressure exerted by the member62on the spool hub34as a result of length L2being greater than length L3, which pushes the spool hub34against the brake surface58with this third predetermined level of pressure. As a result, different levels of braking are placed on the spool hub34by the engagement between the first end98aof the spool hub34and the second end88bof the brake surface58as a result of the level of pressure placed on the spool hub34by the member62.

The change in braking force can be easily changed between the predefined positions by a user without the use of tools. To do so, the user grips the adjustment knob64and pushed the adjustment knob64toward the brake surface58to compress the member62and disengage the tabs138a,138bfrom the mounting recesses, for example mounting recesses130a,130b, in which it is mounted. The adjustment knob64is then rotated to align the tabs138a,138bwith the new desired mounting recesses, for example mounting recesses134a,134b. The adjustment knob64is then released to allow the member62to expand and reseat the tabs138a,138binto the new mounting recesses. This changes the amount of pressure exerted by the member62on the spool hub34and the level of engagement of the spool hub34with the brake surface58.

The preset mounting recesses130a,130b,132a,132b,134a,134bin the braking system32may be designed to correlate to different spools of wire, such as aluminum, stainless steel, flux core, and mild steel. The braking system32prevents the end user from placing too much brake force on the spool hub34, which in turn would prevent the spool hub34from spinning. The braking system32also prevents the user from not applying enough tension which could allow the spool of wire22to overspool.

This differing lengths provided by the mounting recesses130a,130b,132a,132b,134a,134bin the adjustment knob64results in differing lengths of the member62and differing forces generated by the member62. These lengths can be correlated to different types of spools of wire22, i.e. aluminum, stainless, etc., or can be correlated to spool size, i.e. four inch, eight inch, twelve inch. For example, an eight inch spool of aluminum takes much less braking force to prevent overspooling than a twelve inch spool of stainless wire. The adjustment knob64allows the user to change these parameters in a quick fashion without the use of tools.

While three pairs of mounting recesses130a,130b,132a,132b,134a,134bare shown in the drawings and described herein, it is to be understood that there could be more settings available based on changing the geometry of the surfaces in which the tabs138a,138bengage. Also, while two tabs138a,138bare provided, a single tab, for example tab138acould instead be provided.

The adjustment knob64can be marked with indicia148. As shown, indicia148relating to preset forces applied by the member62is provided. Other options for the indicia148include, but are not limited to, A, B, C; 1, 2, 3; or AL, STL, FLX to show what type of wire is being fed. Another option for the indicia148include, but are not limited to, 4, 8, 12 to represent the size of the spool of wire22in inches or millimeters. Yet another option for the indicia148include, but are not limited to, rough weight of spool 1, 10, 40 lbs. or metric ratings.

While various embodiments of the disclosure have been described, it will be apparent to those of ordinary skill in the art that other embodiments and implementations are possible within the scope of the disclosure. Accordingly, the disclosure is not to be restricted except in light of the attached claims and their equivalents.