Plastic welding tool

Claim 2

A tool for welding thermo-plastic base materials together, said tool comprising a rod tube for receiving a welding rod of plastic material and delivering it in softened, bendable condition to a welding position, a hot air tube for receiving hot air under pressure, means in series with said hot air tube for delivering part of said hot air against substantially the entire circumference of the lower part of said rod tube to raise the temperature of the entire circumference of said rod tube over a sufficient length thereof to soften said welding rod to bendable condition for delivery to the welding position and at least one aperture at the lower part of said hot air delivering means and forward of said rod tube for delivering hot air directly to all of the surfaces to be melted for welding.

Claim 3

A tool for welding thermo-plastic base materials together as set forth in claim 1, a pressing and guiding element extending rearwardly from the lower end of said rod tube and an aperture in said hot air delivering means to the rear of said rod tube for directing some of said hot air against said element.

Claim 4

A tool for welding thermo-plastic materials together as set forth in claim 1, said rod tube being secured to said hot air tube, the means in series with aid hot air tube for delivering part of said hot air against said rod tube comprising a jacket extending along part of said rod tube and secured thereto, said aperture being at the lower end of said jacket.

Claim 5

A tool for welding thermo-plastic base materials together as set forth in claim 1, said means for delivering hot air to said rod tube comprising a jacket in series with said hot air tube, said jacket extending around and spaced from said rod tube, said jacket engaging said rod tube at its sides close to the lower end, said aperture being at the lower end of said jacket.

Claim 6

A tool for welding thermo-plastic base materials together as set forth in claim 1, said rod tube being secured to said hot air tube, the means in series with said hot air tube for delivering part of said hot air to the circumfErence of said rod tube comprising a jacket secured to said hot air tube and engaging said rod tube along opposite sides thereof whereby hot air from said hot air tube may flow against that part of the circumferential surface of said rod tube that is within the length of said jacket, and comprising further a smaller tube connected to the interior of said hot air tube to divert thereinto some of said hot air passing through said hot air tube, a portion of said smaller tube located close to the rear of and generally parallel to said rod tube and having openings therethrough opposite said rod tube to direct hot air against another part of the circumferential surface of said rod tube, said aperture being at the bottom of said jacket.

Claim 7

A tool for welding thermo-plastic base materials together as set forth in claim 5, said smaller tube having a bottom opening to the rear of said rod tube.

Claim 8

A tool for welding thermo-plastic base materials together as set forth in claim 1, said rod tube being secured to said hot air tube, the means in series with said hot air tube for delivering part of said hot air to the circumference of said rod tube comprising a jacket secured to said hot air tube and engaging said rod tube along opposite sides thereof whereby hot air from said hot air tube may flow against that part of the circumferential surface of said rod tube that is within the length of said jacket, and comprising further a smaller tube connected to the interior of said hot air tube to divert thereinto some of said hot air passing through said hot air tube, said smaller tube having a longitudinal opening over part of its length, said rod tube having part of its surface secured within said opening, and said aperture being at the bottom of said jacket.

Claim 9

A tool for welding thermo-plastic base materials together as set forth in claim 4, said jacket being made of sheet material and secured to said hot air tube and said rod tube at its upper end thereby to provide a continuous closed passage to the lower end of said jacket, the area of the aperture at the lower end of said jacket being substantially less than the maximum cross-sectional area of said jacket whereby escape of hot air may be retarded to improve heat transfer to said rod tube.

Claim 10

A tool for welding thermo-plastic base materials together comprising a rod tube through which passes a welding rod during the welding operation, means for utilizing high temperature hot air for heating said rod by radiation and conduction to bendable condition while within said rod tube and for heating, by the direct application of hot air, the converging surfaces of the base materials and the under surface of said rod to melting condition just prior to welding contact thereof as the tool is advanced along the line of weld, said means comprising a jacket surrounding said rod tube and spaced therefrom over at least a major part of the rod tube circumference, means for delivering hot air to said jacket from a hot air source whereby said rod tube will be heated substantially uniformly over that part of its length that is within said jacket, at least one opening at the bottom of said jacket for allowing escape of said hot air, the said opening acting to direct hot air to the surfaces of said base materials and rod that are about to be welded as the tool is advanced.

Claim 11

A tool for welding thermo-plastic base materials together comprising a rod tube through which passes a welding rod during the welding operation, means for utilizing high temperature hot air for heating said rod by radiation and conduction to bendable condition while within said rod tube and for heating, by the direct application of hot air, the converging surfaces of the base materials and the under surface of said rod to melting condition just prior to welding contact thereof as the tool is advanced along the line of weld, said means comprising a jacket surrounding said rod tube and spaced therefrom over at least a major part of the rod tube circumference, means for delivering hot air to said jacket from a hot air source whereby said rod tube will be heated substantially uniformly over that part of its length that is within said jacket, at least one opening at the bottom of said jacket for allowing escape of said hot air, the said opening acting to direct hot air to the surfaces of said base materials and rod that are about to be welded as the tool is advanced.

Claim 12

A tool for welding thermo-plastic base materials together as set forth in claim 9, said jacket over a part of the length of said rod tube being completely spaced therefrom.

Claim 13

A tool for welding thermo-plastic base materials together as set forth in claim 9, said rod tube having a rearwardly extending guiding and pressing element said jacket having another bottom aperture above said element whereby some of the said hot air may be directed at said element.