Resistance welding machine

Abstract

A resistance welding machine, particularly suited to carry out repairs on metallic bodies, includes a machine body housing a rechargeable electric battery for supplying the electrical energy that is necessary for the welding cycle, a rod carrying the welding electrode, and a rod carrying the earth electrode. Both of the earth rod and the welding rod are electrically connected to the battery, which is the only source of electrical energy for the resistance welding machine.

Claims

1. A resistance welding machine comprising: a machine body (11) housing one or more electric batteries (2), a welding rod (4) carrying a welding electrode, the welding rod being constrained with one end (46) to the machine body (11) and comprising, at an opposite free end (47), the welding electrode or welding tip (41), and an earth rod (3) carrying an earth electrode, the earth rod being constrained with one end (35) to the machine body (11) and comprising, at an opposite free end (36), an earth electrode or earth tip (31), wherein both of said earth rod (3) and said welding rod (4) are electrically connected to at least one of said one or more batteries, and wherein at least one of said one or more batteries (2) is an only source of electric current for a welding operation.

2. The resistance welding machine (1) according to claim 1, wherein the resistance welding machine comprises one or more MOSFET devices.

3. The resistance welding machine (1) according to claim 1, wherein said earth rod (3) and said welding rod (4) are arranged parallel to each other and side by side.

4. The resistance welding machine (1) according to claim 1, wherein one or both of said earth rod (3) and said welding rod (4) is/are telescopic and/or sliding and/or axially translating with respect to said machine body (11) independently of each other.

5. The resistance welding machine (1) according to claim 4, wherein each of said earth rod (3) and welding rod (4) is housed in a corresponding seat or guide (141, 142) obtained in said machine body (11).

6. The resistance welding machine (1) according to claim 5, wherein inside each of said seats (141, 142) where the welding and the earth rods (3, 4) slide there is a spring (33, 42) suited to counteract a sliding movement of said welding and said rods (3, 4) towards an inside of the machine body (11).

7. The resistance welding machine (1) according to claim 5, wherein said earth rod (3) slides within an insulating tube (32) inserted in the corresponding seat or guide (142).

8. The resistance welding machine (1) according to claim 1, wherein said welding rod (4) has a non-circular cross section and is inserted in a guide bushing (43) having a seat whose shape corresponds to a shape of the cross section of said welding rod (4), with an anti-rotational function, and wherein said welding rod is configured to have an end-of-stroke stop element (44) fixed thereto.

9. The resistance welding machine (1) according to claim 1, wherein said earth electrode (31) is made of copper and said welding electrode (41) comprises a steel tip.

10. The resistance welding machine (1) according to claim 1, wherein said machine body (11) comprises a grip (12), a button (13) for starting the welding machine being positioned adjacently to the grip.

Description

[0030] FIG. 1 shows a section of the new electric resistance welding machine (1).

[0031] The new electric resistance welding machine (1) is particularly suitable for conducting metal auto body repairs, for extracting and leveling dents of metal sheets.

[0032] The new electric resistance welding machine (1) comprises a machine body (11) with handle (12) near which at least one button (13) is positioned for switching the welding machine on and off.

[0033] The new electric resistance welding machine comprises at least one earth electrode holder (3), constrained at one end (35) to the machine body (11) in a sliding manner and comprising, at the opposite free end (36), the earth electrode (31).

[0034] The new electric resistance welding machine comprises at least one welding electrode holder (4), constrained at one end (46) to the machine body (11) in a sliding manner and comprising, at the opposite free end (47), the welding electrode (41).

[0035] Said earth electrode (31) is preferably made of copper, while said welding electrode (41) has a steel tip.

[0036] Said earth electrode (31) and welding electrode (41) are constrained to the relative electrode holders (3, 4) in a removable or non-removable manner.

[0037] Said earth electrode holder (3) and welding electrode holder (4) are both connected, for example by means of a corresponding copper conductor, to the rechargeable battery (2) of the welding machine contained in said machine body (11), which in turn can be connected to the electrical power source consisting of one or more batteries (2).

[0038] Said earth electrode holder (3) and welding electrode holder (4) are partly housed in corresponding seats or guides (141, 142) located in said machine body (11) and arranged parallel to each other and side by side at a close distance.

[0039] Said earth electrode holder (3) and welding electrode holder (4) are telescopic and/or axially sliding in said seats (141, 142) with respect to said machine body (11) independently of each other. Said electrode holders (3, 4) may, for example, have a total sliding stroke of 20-50 mm.

[0040] In order to isolate said earth electrode holder (3) from the machine body (11), said electrode holder (3) slides in an insulating tube (32), for example made of fiberglass with high thermal resistance, even up to 200° C., inserted in the relative seat or guide (142), and said end (35) of the earth electrode holder (3) constrained to the machine body (121) is housed in an insulating flange (34).

[0041] The welding electrode holder (4) has a non-circular section, for example hexagonal, and is inserted in a guide bush (43) preferably made of brass, with a seat having a shape corresponding to the section of said welding electrode holder (4), with an anti-rotation function to detach said welding electrode (41) from the sheet metal on which it was used at the end of the cycle.

[0042] There is also an end-of-stroke stop element (44) on said welding electrode (4) on which the pull strokes the welder makes to reshape the deformed part of the car body are discharged.

[0043] A compression spring (33, 42) is mounted inside each of said seats (141, 142) of the electrode rod holders (3, 4), suited to counteract the sliding of said electrode holders (3, 4) towards the inside of the machine body (11).

[0044] In the machine body itself there are one or more electric batteries (2) to supply all the electric energy necessary to perform the electric welding.

[0045] The batteries, preferably of the LI-PO type, are sized so as to provide sufficient autonomy to perform a suitable number of welds.

[0046] These specifications are sufficient for the expert person to construct the welding machine of the invention, and as a result, in the practical application there may be variations without prejudice to the substance of the innovative concept.

[0047] Therefore, with reference to the preceding description and the attached drawing the following claims are made.