STROBIETTO, Elio (Via Marsigli 82, Torino, I-10141, IT)
| CLAIMS 1. Clamp for the electric welding comprising • a pair of pincers (2) pivoted on a pin (3) positioned in a substantially intermediate position between the two pincers, • a pair of electrodes (4) arranged in proximity of the front end of the pincers adapted for receiving the electric current and for aiding the welding of elements retained between them, • the rear portion of the pincers with respect to said pin being used as handle (22) , • a pressure group (6) arranged between the two pincers adapted for controlling the manual pressure exerted by the clamp on the elements to be welded through said handle, characterized in that each pincer is provided in its interior with at least a longitudinal channel (5) for the passage of gas at whose termination is provided at least a pair of holes (51) of gas emission arranged in proximity of said electrodes (4) . 2. Clamp according to claim 1, wherein the holes of emission (51) are four, two per pincer. 3. Clamp according to claim 1, wherein said electrodes (4) are conical at an end or on both of them that are press inserted in holes (21) also conical that pass through the pincers from one side to the other allowing for the extraction and/or insertion of each electrode. 4. Clamp according to claim 3, wherein the ending portion of the pincers is inclined with respect to the rest of the body and the conical seats (21) are in turn inclined with respect to the inner part of the pincer for being perpendicular to the part to be welded when the clamp is closing. 5. Clamp according to claim 1, wherein the pincers in the part used as handle (22) presrent a rounded, striated or corrugated and with a slightly bigger shape with respect to the structure. 6. Clamp according to claim 1, wherein the pressure group (6) comprises a spring (61) that is adjusted through a ring nut (62) for varying the thrust force and two containment brackets (63) . 7. Clamp according to claim 6, wherein the spring can be substituted by a pneumatic cylinder (64) . At its rear end each . pincer (2) presents a covering (23) for the connection of the clamp with a flexible wire (7) covered by a silicon sheath. Both the electric current for the electrodes and the gas pass through said wire .. 8. Clamp according to claim 1, wherein the body of the clamp is made in light aluminum alloy to which a special treatment of hard/anodic oxidation is made, after which it appears covered by a ceramic material coat . |
The present invention relates to a clamp for the electric welding. In particular, the present invention refers to a clamp usable for realizing an intra-oral electric-welding in titanium and its alloys.
It is known that . the titanium electro-welding occurs in virtue of a process named syncrystalization.
In order to carry out the syncrystalization it is necessary to apply a certain mechanical pressure, carry out a transition of current which is able to develop, according to the Joule effect, the necessary heating for the welding.
Practically, the welding occurs thanks to the passage of an elevated intensity current, together with a mechanical pressure to be exerted on the surfaces to be welded, which are kept in close contact between them. In document EP1579821 it is described an equipment for carrying out an electro-welding wherein it is used a clamp having a pair of electrodes among which the elements to be welded can be positioned, connected to an electric current generator for heating the material to be welded up to the melting point; it is also provided a inlet nozzle for argon gas in correspondence to the welding zone.
In correspondence to the contact zone of the electrodes it is provided a nozzle for the argon gas emission, which connects through a duct to a pressurized argon source, which permits to create an inert ambient in the welding zone.
The Applicant has observed that the welding operations which the clamp has to carry out will be reliable if the pressure exerted by the clamp itself on the two parts to be welded is controllable in a precise way and if the argon flow is directed in an equally precise way in direction of the welding zone. Therefore, a duct bringing the above-said gas as the one described in the abovementioned patent application other than being bulky owing to its central position between the pincers of the clamp, it does not ensure the argon flow to exactly hit the welding zone.
The present invention solves this issue by providing a clamp for the electro-welding wherein the Argon gas, or other gases, passage, occurs through a hole in each pincer; and therefore the ducts that bring the gas are obtained inside the structure of the pincers themselves. In this way, the gas passes through the pincer itself and exits directly in proximity of the electrodes and therefore does not need tubes external to the structure of the pincer.
An aspect of the present invention refers to a clamp for the electro-welding having the characteristics of claim 1.
The characteristics and the advantages of the clamp according to the present invention will be clearer and evident from the following description, exemplificative and non- limiting, of an embodiment made with reference to the attached figures wherein: - figure 1 shows a lateral view of the clamp according to the present invention;
- figure 2a shows a sectional view of the clamp of figure 1;
- figure 2b shows a sectional view of the clamp according to another embodiment of the invention;
- figure 3a shows a lateral view of the clamp according to an embodiment of the pressure means;
- figure 3b shows a lateral view of the clamp according to another embodiment of the pressure means;
figure 4 shows a sectional view of the clamp according to the present invention connected to a flexible wire for bringing the electric power and gas. With reference to the mentioned figures, the clamp according to the present invention comprises a pair of pincers 2 pivoted on a pin 3 positioned in a substantially intermediate position between the two pincers .
The body of the clamp is preferably made in light aluminum alloy to which a special treatment of hard/anodic oxidation is made, after which it appears covered by a ceramic material coat which acts as unique body with the aluminum basis . The oxidized layer is very thick and compacted and has an elevated resistance to wear and scratches, which added to the ultra- elevated dielectric resistance permits the mounting of the two parts without the need of intermediate insulators .
In proximity of the front end of the pincers is provided a pair of electrodes 4 adapted for receiving the electric current and for aiding the welding of elements retained between them. These electrodes are preferably conical at an end or on both of them that are press-inserted in holes 21 also conical that pass through the pincers from one side to the other allowing for the extraction and/or insertion of the electrode in an easy and practical way. This operation can be made by anyone even without specific knowledge. The electrode results in this way simple and of easy maintenance and being conical does not have plays because it is always under pressure .
The ending portion of the pincers is preferably inclined with respect to the rest of the body and conical seats 21 are in turn inclined with respect to the inner part of the pincer in order to, when the clamp is closing, the electrodes are perpendicular to the part to be welded, avoiding the parts to be welded to move due to the pressure applied to the ends of the electrodes.
Each pincer is provided in its inner part with at least a longitudinal channel 5 for the passage of gas at whose termination is provided at least a pair of holes 51 of gas emission arranged in proximity of said electrodes. In the form of embodiment shown in figure 2b the holes of emission are four, two per pincer.
In this way the clamp object of the present invention does not need external tubes for conveying gases that in certain cases obstruct the view of the part to be welded. Furthermore, the flows generated in this way completely wind the parts to be welded.
The pincer in the rear part with respect to the pin is used as handle 22 and presents a rounded, striated or corrugated and with a slightly bigger shape with respect to the structure for permitting a comfortable and safe gripping.
The clamp comprises also a pressure group 6 arranged between the two pincers adapted for controlling the manual pressure exerted by the clamp on the elements to be welded through that handle.
This group preferably comprises a spring 61 that is adjusted through a ring nut 62, for varying the thrust force and two containment brackets 63. In an alternative form of embodiment, the spring can be replaced by a pneumatic cylinder 64.
To its rear end each pincer 2 presents a covering 23 for the connection of the clamp with a flexible wire 7 covered by a silicon sheath. Both the electric current for the electrodes and the gas pass through said wire. This extremely practical solution avoids the use of a sheath split into two parts which in the long run can inevitably be damaged. The other end of the wire ends in a multipolar socket 8 which is press-inserted in a machine for the welding.
Another solution consists in let passing the gas through a flexible tube positioned inside the wire and fixed through a connection directly to the contact and to the cable terminal both holed with passing hole.