Description: FIELD OF INVENTION

The present invention relates to welding guns. In particular, the present invention relates to welding guns for welding components. More particularly, the present invention relates to an auto air cut-off system for welding guns for welding of components in a manufacturing plant.

BACKGROUND OF THE INVENTION

Any manufacturing plant requires welding of a variety of metallic components to be used in different sub-assemblies. For example, in any Bodyshop, a welding stud is placed (with a hand tool simply referred to as Stud Gun) in contact with the base metal on which it is to be welded. Then, a weld arc is drawn to melt this welding stud base as well as the relevant area of the metallic workpiece for permanently fastening them together. Thereafter, the welding stud is forced into the melted area and held in place until the metals re-solidify. Such welded studs are used to fit other parts in a sub-assembly of automotive vehicle TRIM.

Stud welding guns work on compressed air-pressures between 4 to 6 bar. On detecting any error/fault, the stud welding gun stops any further welding operation and the machine indicates this error/fault. The maintenance personnel need to open the stud receiver cover to correct the fault by checking the stud welding gun.

However, this welding gun inspection may harm the maintenance personnel or their associate/s while rectifying such faults. Particularly, when the air-pressure is not released or the valve is not closed or the power-supply is not switched-off, the loading pin may inadvertently operate and pose a fatal hazard and may even injure the maintenance person.

At present, there is no arrangement to shut-off the air-supply to the push rod cylinder, when the flash shield and stud receiver is removed. Often, this causes cut/injury to the welding associate’s thumb as the cylinder piston gets operated while undertaking any error/fault resolution process. This injury to the hand/s of the maintenance personnel even has a high-probability of disability.

Therefore, there is an existing need in the relevant art for providing a system for automatically cutting-off air-supply to the welding during welding gun maintenance operation.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide an improved welding gun which automatically cuts off air-supply during any error/fault correction operation.

Another object of the present invention is to provide a welding gun with automatic air-supply cut-off system which is simple in construction.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF INVENTION

The present invention discloses a stud welding gun with an automatic air-supply cut-off mechanism for the maintenance thereof; the automatic air-supply cut-off mechanism comprises: a support for a face shield assembly; a stud stop and a flange-assembly; a collet; a swivel nut and a cable package; a loading pin assembly; a coupling-plate assembly; a self-centering disc fitted on the face shield assembly; and a microswitch; wherein the microswitch is configured to operate a second additional solenoid valve for actuating the first solenoid valve for enabling air-supply behind said loading pin; or the microswitch contact is opened for shutting-off the air supply by the piston rod cylinder on removing the flash-shield cover for preventing the operation of the loading pin during the maintenance of the welding gun to avoid any possible fatal hazard and/or injury to the maintenance personnel.

STATEMENT OF THE INVENTION

In accordance with the present invention, there is provided a stud welding gun with an automatic air-supply cut-off mechanism for the maintenance thereof; the automatic air-supply cut-off mechanism comprising:

(a) a support for a face shield assembly;
(b) a stud stop and a flange-assembly;
(c) a collet;
(d) a swivel nut and a cable package;
(e) a loading pin assembly;
(f) a coupling-plate assembly; and
(g) a self-centering disc fitted on the face shield assembly; and
(h) a microswitch;

wherein the microswitch is configured to cut-off the air-supply behind the loading pin to prevent the operation thereof on removal of the flash-shield to avoid any possible fatal hazard and/or injury to the maintenance personnel during the maintenance operation of the stud welding gun.

Typically, the face shield assembly comprises:
- a flash shield support;
- a flash shield holder fitted with a self-centering disc;
- receiver with a cover thereof;
- a threaded pin;
- a flash shield;
- a swivel-nut;
- a swivel-nut flash-shield;
- a bellows cylinder;
- a sealing ring;
- a distance bush; and
- a stud-stop;
wherein the face-shield assembly is removed only after the air-supply behind said loading pin is cut-off by means of the microswitch.

Typically, the flange-assembly comprises:
- a collet;
- a clamping ring;
- a connecting flange;
- a clamping flange;
- a distance sleeve; and
- a swivel nut;
wherein the flange-assembly is used to guide the loading pin movement.

Typically, the air-supply cut-off mechanism comprises:
• a cable package;
• a piston rod cylinder;
• a first solenoid valve;
• an air-connection block; and
• an air-supply and
• a loading pin assembly
wherein the air-supply cut-off mechanism is activated to cut-off the air-supply behind the loading pin by means of the microswitch to start the maintenance of the stud welding gun.

Typically, the microswitch assembly comprises a contact and a second solenoid valve and the microswitch assembly is connected in series with the piston rod cylinder.

Typically, the coupling-plate assembly comprises a locking switch and a casing for the locking switch.

In one embodiment of the present invention, the microswitch is configured to operate the second solenoid valve for actuating the first solenoid valve for enabling the air-supply behind the loading pin for starting the operation of the stud welding gun.

Typically, the microswitch is configured to open the contact of the microswitch on removing the flash-shield, for cutting off the air supply by the piston rod cylinder to prevent the operation of the loading pin during any maintenance operation the stud welding gun to eliminate any possible fatal hazard and/or injury to the maintenance personnel.

In another embodiment of the present invention, the automatic air-supply cut-off mechanism comprises:

(a) a face shield assembly comprising:
(i) a flash shield support;
(ii) a flash shield holder fitted with a self-centering disc;
(iii) receiver with a cover thereof;
(iv) a threaded pin;
(v) a flash shield;
(vi) a swivel-nut;
(vii) a swivel-nut flash-shield;
(viii) a bellows cylinder;
(ix) a sealing ring;
(x) a distance bush; and
(xi) a stud-stop;

(b) a flange-assembly comprising:
(I) a collet;
(II) a clamping ring;
(III) a connecting flange;
(IV) a clamping flange;
(V) a distance sleeve; and
(VI) a swivel nut;

(c) an air-supply cut-off mechanism comprising;
• a cable package;
• a piston rod cylinder;
• a first solenoid valve;
• an air-connection block; and
• an air-supply;

(d) a loading pin assembly;

(e) a coupling-plate assembly comprising a locking switch and a casing for the locking switch; and

(f) a microswitch having a contact and a second valve and connected in series with the piston rod cylinder;

wherein the microswitch is configured to operate the second solenoid valve for actuating the first solenoid valve for starting the air-supply behind the loading pin to enable the operator to start the welding operation with the stud welding gun by feeding the studs by means of an automatic stud feeding mechanism.
Typically, the microswitch contact is opened for cutting off the air supply by the piston rod cylinder on removing the flash-shield, to prevent the operation of the loading pin pushing the studs fed by means of the automatic stud feeding mechanism, during the maintenance of the stud welding gun to eliminate any possible fatal hazard and/or injury to the maintenance personnel.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described in the following with reference to the accompanying drawings.

FIGURE 1 shows a perspective view of a stud welding gun with automatic air-supply cut-off mechanism configured according to the present invention.

FIGURE 2 shows an exploded view of the stud welding gun with an automatic air-supply cut-off mechanism of Figure 1.

FIGURE 3 shows another perspective view of the stud welding gun with an automatic air-supply cut-off mechanism of Figure 1.

FIGURE 4 shows a schematic arrangement of the automatic stud feeding mechanism attached to the stud welding gun shown in Figure 3.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the stud welding gun with an automatic air-supply cut-off mechanism configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention.

The embodiment shown herein provides a stud welding gun with an automatic air-supply cut-off mechanism configured in accordance with the present invention. The embodiment shown herein provides the stud welding-gun which is simple in construction. Now, referring to the figures of the accompanying drawings, it should be noted that similar reference numerals/characters denote the corresponding features consistently throughout the figures submitted herewith.

FIGURE 1 shows a perspective view of an improved stud welding-gun 100 configured with an automatic air-supply cut-off mechanism 150 (Figure 2) according to a preferred embodiment of the present invention, as disclosed herein. For the purpose of this description and ease of understanding, the aforesaid stud welding-gun 100 is explained herein below with reference to be components typically available therein. The main components of the stud welding gun 100 are a flash shield support 10, flash shield 20 with insulating bush 22 (not visible here), stud stop 30, collet 40, swivel nut 50 and cable package 60, loading pin 70, and a microswitch 75. Here, the automatic air-supply cut-off mechanism is encircled as Ex, i.e. the exploded view is shown in Figure 2.

FIGURE 2 shows an exploded view of the automatic air-supply cut-off mechanism 150 of the stud welding gun 100 shown in Figure 1 above. The automatic air-supply cut-off mechanism 150 comprises a flash shied holder 12, cover for receiver 14, receiver 16, threaded pin 18, flash shield 20, swivel nut flash shield 24, bellows cylinder 25, sealing ring 26, distance bush 28, collet 40, clamping ring 42, connecting flange 44, clamping flange 46, distance sleeve 48, swivel nut 50, cable package 60, adjusting stud 62, a first solenoid valve 64 and a second solenoid valve 54, air-connection block 66, loading pin complete 70, coupling plate 80, locking switch 82, casing for locking switch 84, and self-centric disc 90. The stud welding gun 100 is provided with a microswitch 75 fitted on flash shield 20. This microswitch 75 is connected in series with piston rod cylinder 62 such that on removing the flash shield 20, the contact of microswitch 75 gets opened and first solenoid valve 64 shuts off air supply 68 of piston rod cylinder 62 to prevent the operation of loading pin 70, particularly during any maintenance operation the stud welding gun 100.

FIGURE 3 shows a perspective view of a preferred embodiment of the stud welding gun 100 with an automatic air-supply cut-off mechanism of Figure 1 attached with an automatic stud feeding mechanism 200 for supplying the studs to be welded by the stud welding gun 100.

FIGURE 4 shows a schematic arrangement of the automatic stud feeding mechanism 200 attached to the stud welding gun 100 shown in Figure 3. This arrangement 200 includes an external switch mode power supply 52 converting 230 V AC power supply into 24 V DC power supply for operating the microswitch 75 fitted on the stud welding gun 100. A second solenoid valve 54 is operated by the microswitch 75 to supply compressed air 68 for actuating the first solenoid valve 64 by applying this air 68 behind the loading pin 70 as shown in Figure 1.

It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications
Another object of the present invention is to provide

WORKING OF THE INVENTION

In the following, the working principle of the automatic air-supply cut-off mechanism 150 of the stud welding gun 100 is explained in detail:

• Whenever the stud welding operation is triggered, first the air-supply 68 is turned ON. Simultaneously, a stud is fed by automatic stud feeding mechanism 200 (Figures 3).

• Subsequently, the microswitch 75 is operated by the second solenoid valve 54 to supply compressed air 68 for actuating the first solenoid valve 64 of the loading pin 70 by applying this compressed air 68 behind the loading pin 70.

• Finally, the loading pin 70 pushes the stud towards the flash shield 20 to be located in the correct location thereof.

However, before starting any maintenance operation, the microswitch 75 is connected in series with the piston rod cylinder 62, so that on removing the flash shield 20, the contact of the microswitch 75 gets opened and the first solenoid valve 64 shuts off compressed air 68 supply of the piston rod cylinder 62 to prevent the operation of loading pin 70. Thereby, any inadvertent operation of the loading pin 70 is readily prevented to avoid any possible fatal hazard and/or injury to the maintenance personnel.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The stud welding-gun configured with an automatic air-supply cut-off mechanism configured in accordance with the present invention offers the following advantages:

- Interlock added with flash shield to Avoid Injury.

- Mechanism can be retrofitted in any stud welding gun for fool proof system to avoid human disability.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of sizes, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top”, and “bottom” as well as derivatives thereof (e.g. “horizontally”, “inwardly”, “outwardly”; “downwardly”, “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation. , Claims: We claim:

1. A stud welding gun (100) with an automatic air-supply cut-off mechanism (150) for the maintenance thereof; said air-supply cut-off mechanism (150) comprising:

(a) a support (10) for a face shield (20) assembly;
(b) a stud stop (30) and a flange-assembly;
(c) a collet (40);
(d) a swivel nut (50) and a cable package (60);
(e) a loading pin (70) assembly;
(f) a coupling-plate (80) assembly;
(g) a self-centering disc (90) fitted on said face shield assembly (20); and
(h) a microswitch (75);

wherein said microswitch (75) is configured to cut-off the air-supply behind said loading pin (70) to prevent the operation thereof on removal of said flash-shield (20) to avoid any possible fatal hazard and/or injury to the maintenance personnel during the maintenance operation of said stud welding gun (100).

2. The stud welding gun (100) as claimed in claim 1, wherein said face shield (20) assembly comprises:

- a flash shield support (10);
- a flash shield holder (12) fitted with a self-centering disc (90);
- receiver (14) with a cover (16) thereof;
- a threaded pin (18);
- a flash shield (20);
- a swivel-nut (22);
- a swivel-nut flash-shield (24);
- a bellows cylinder (25);
- a sealing ring (26);
- a distance bush (28); and
- a stud-stop (30);

wherein said face-shield assembly is removed only after the air-supply (68) behind said loading pin (70) is cut-off by means of said microswitch (75).

3. The stud welding gun (100) as claimed in claim 1, wherein said flange-assembly comprises:

- a collet (40);
- a clamping ring (42);
- a connecting flange (44);
- a clamping flange (46);
- a distance sleeve (48); and
- a swivel nut (50)

wherein said flange assembly used to guide the movement of said loading pin (70).

4. The stud welding gun (100) as claimed in claim 1, wherein said air-supply cut-off mechanism comprises:

• a cable package (60);
• a piston rod cylinder (62);
• a solenoid valve (64);
• an air-connection block (66);
• an air-supply (68) and
• a loading pin (70) assembly;

wherein said air-supply cut-off mechanism (150) is activated to cut-off air-supply behind said loading pin (70) by means of said microswitch (75) to start the maintenance of said stud welding gun (100).

5. The stud welding gun (100) as claimed in claim 1, wherein said microswitch (75) assembly comprises a contact and an additional solenoid valve (54) and said microswitch (75) assembly is connected in series with said piston rod cylinder (62).

6. The stud welding gun (100) as claimed in claim 1, wherein said coupling-plate (80) assembly comprises a locking switch (82) and a casing (84) for said locking switch (82).

7. The stud welding gun (100) as claimed in claim 1, wherein said microswitch (75) is configured to operate said additional solenoid valve (54) for actuating said solenoid valve (64) for enabling said air-supply (68) behind said loading pin (70) for starting the operation of said stud welding gun (100).

8. The stud welding gun (100) as claimed in claim 1, wherein said microswitch (75) is configured to open the contact of said microswitch (75) on removing said flash-shield (20), for cutting off said air supply (68) by said piston rod cylinder (62) to prevent the operation of said loading pin (70) during any maintenance operation said stud welding gun (100) to avoid any possible fatal hazard and/or injury to the maintenance personnel.

9. The stud welding gun (100) as claimed in claim 1, wherein said automatic air-supply cut-off mechanism (150) comprises:

(a) a face shield (20) assembly comprising:
(i) a flash shield support (10);
(ii) a flash shield holder (12) fitted with a self-centering disc (90);
(iii) a receiver (14) with a cover (16) thereof;
(iv) a threaded pin (18);
(v) a flash shield (20);
(vi) a swivel-nut (22);
(vii) a swivel-nut flash-shield (24);
(viii) a bellows cylinder (25);
(ix) a sealing ring (26);
(x) a distance bush (28); and
(xi) a stud-stop (30);

(b) a flange-assembly comprising:
(I) a collet (40);
(II) a clamping ring (42);
(III) a connecting flange (44);
(IV) a clamping flange (46);
(V) a distance sleeve (48); and
(VI) a swivel nut (50);

(c) an air-supply cut-off mechanism comprising;
• a cable package (60);
• a piston rod cylinder (62);
• a first solenoid valve (64);
• an air-connection block (66); and
• an air-supply (68);

(d) a loading pin (70) assembly;

(e) a coupling-plate (80) assembly comprising a locking switch (82) and a casing (84) for said locking switch (82); and

(f) a microswitch (75) having a contact and a second solenoid valve (54) and connected in series with said piston rod cylinder (62);

wherein said microswitch (75) is configured to operate said second solenoid valve (54) for actuating said first solenoid valve (64) for starting said air-supply (68) behind said loading pin (70) to enable the welding gun operator to start the welding operation with said welding gun (100) by feeding the studs by means of an automatic stud feeding mechanism (200).
10. The stud welding gun (100) as claimed in claim 9, wherein said microswitch (75) contact is opened for shutting-off said air supply (68) by said piston rod cylinder (62) on removing said flash-shield (20), for preventing the operation of said loading pin (70) pushing the studs fed by means of said automatic stud feeding mechanism (200), during the maintenance of said welding gun (100) to eliminate any possible fatal hazard and/or injury to the maintenance personnel.

Dated this 22nd day of April 2022.

Digitally / e-Signed.

(SANJAY KESHARWANI)
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA-2043.