NOZZLE FOR HOT GAS WELDING OF PLASTICS

Abstract: A nozzle for welding plastic floor and wall covering, comprising a metal sleeve, the rear part (1) of which is tubular and may be connected to a conduit or the like for the supply of hot air to the inside of the sleeve. The nozzle is provided with a front end or tip (2) which is dome-shaped and completely closed. To the rear of the tip there are two diametrically opposed openings (6, 7) for the expulsion of hot air, said openings being directed obliquely forward and the sleeve being void of further openings between the said two openings.

Description: "Nozzle for hot gas welding of plastics." TECHNICAL FIELD The invention relates to a nozzle for welding plastic flooring and wallcovering. BACKGROUND ART When plastic flooring is to be laid in toilets, bathrooms and the like, corners, thresholds, and piping create problems. In such places it is difficult to make the joints fully watertight, and even more difficult to make them smooth and dirt-repellant as well. Up to now a variety of techniques has been applied in order to melt or soften the filler rod and to even the molten material out. Generally, hot air has been used to melt the filler, and then the material has been evened out with different types of tools. The result, however, has not been satisfactory. Among the potential problems may be mentioned the risk of burning holes in the plastic flooring, discolouring the flooring or the joint by excessive heating, not acheiving the desired surface finish, and the development of poisonous or at least irritating fumes. DISCLOSURE OF THE INVENTION The object of the invention is to provide a nozzle which will help to eliminate the problems outlined above. Said nozzle is characterized in that it comprises a metal sleeve with a tubular rear part, intended to be connected to a conduit of some kind for the supply of hot air to the inside of the sleeve, and with a dome-shaped and completely closed front end or tip, there being two diametrically opposed, obliquely forward directed orifices for the expulsion of hot air, the sleeve lacking further openings between said orifices. This nozzle thus is instrumental both in heating the filler material and in smoothing the surface. It may also be applied to the sealing of small holes in the plastic flooring. The nozzle is preferably rotationally symmetrical, and the dome-shaped tip is preferably essentially a half-sphere. The word tip hence does not indicate that the front end is pointed. As used, the word tip has the same meaning as for example in finger-tip. The two orifices are preferably located immediately behind the tip. According to a preferred embodiment, the material of the central part of the tip is considerably thinner than that of the sleeve in the area of the orifices. Further characteristics and advantages of the invention will become apparent from the appended patent claims and the following description of a preferred embodiment. BRIEF DESCRIPTION OF DRAWINGS In the following description of a preferred embodiment, reference will be made to the accompanying drawings, wherein Fig. 1 is a view in perspective of the nozzle according to the invention, as seen from ahead at an angle; Fig. 2 is an elevation of the same nozzle; and Fig. 3 is a sectional view along the line III—III of Fig. 2. DESCRIPTION OF A PREFERRED EMBODIMENT The nozzle illustrated by the drawings comprises a tubular brass sleeve 1 with a blunt, half-spherical smooth tip 2. The sleeve 1 is rotationally symmetrical. A hot-air conduit 3 may be connected to the rear end of the sleeve 1. To facilitate the assembly and disassembly of the sleeve 1 and the conduit 3 there is provided a handling collar 4. Through the cylindrical part 5 of the sleeve 1 there extend two bores 6, 7 forwards at an angle, and they open immediately to the rear of the part of half-spherical shape. The axial distance from the centre of the tip 2 to the front edges of the bores 6, 7 is between 4 and 10 mm, depending on the other dimensions of the nozzle. Through the openings 6, 7 hot air may be directed at the joint, even when the work is carried out in corners. The absence of any openings in other directions, in other words transversely in relation to the diametrical plane of the openings 6 and 7, prevents heat and consequent damage from reaching the flooring material on either side of the joint. In other words, the hot air is directed strictly to the areas where it is needed. The material of the central part 8 of the tip 2 is thinner than that of the tubular part 5. A suitable thickness is 1 - 2 mm. If the material is thicker, the temperature of the air must be increased to keep the tip 2 hot enough. This may on the other hand cause the hot air to damage the plastic material in the vicinity. Remaining plastic on the tip may also be scorched as one changes working area. The nozzle may of course be modified within the scope of the invention. Thus, the nozzle need not be entirely straight. It is thus fully conceivable that the tubular part be bent, so as to facilitate work in hard-to-reach corners and nooks.

Claims: CLAIMS: 1. A nozzle for welding plastic floor and wall covering, comprising a metal sleeve with a tubular rear part (1) for the connection to a conduit or the like which supplies hot air to the inside of the sleeve and with a front end or tip (2), c h a r a c t e r i z e d i n that said tip (2) is rounded and dome-shaped and completely closed, there being provided behind said dome-shaped tip, in the junction area between a cylindrical part and said dome-shaped tip, two diametrically opposed openings (6, 7) for the expulsion of hot air, said openings being directed obliquely forward, said sleeve being void of further openings between said two openings, and the material (8) of the central part of the tip being considerably thinner than the material (5) of the sleeve in the region of the said openings (6, 7). 2. A nozzle according to claim 1, c h a r a c t e r i z e d i n that it is rotationally symmetrical. 3. A nozzle according to claim 2, c h a r a c t e r i z e d n that the dome-shaped tip (2) is shaped essentially like a half-sphere.

Inventors: AOBERG KJELL, AOBERG, KJELL
Applicants: AOBERG KJELL, AOBERG, KJELL
Application year: 1985
Main classification: B29C65
IPC codes: B29C65