Chimney construction for heating fixtures

Claim 2

A coupling for joining metallic circular chimney sections comprising an integral body of thin-gage sheet metal, formed to have first and second circular coaxial end segments joined by a radial step, the first end segment being shaped with an external hem formed by a reversely looped outer end portion sized to receive and engage the inside end of a first adjoining circular metallic chimney section thereover, the second end segment being shaped with an internal hem formed by a reversely looped outer end portion sized to receive and engage the outside end of a second adjoining circular metallic chimney section therein, the first end segment extending radially inwardly of the step whereby said external hem on said first end segment is radially offset with said internal hem on said second segment a distance equal to the thickness of said chimney section mating with said first end segment, and said first and second end segments are thereby radially offset a distance equal to the combined thickness of said chimney section and said reversely looped outer ends whereby said step also providing a common stop for axial travel of the first and second chimney sections when in engagement with the coupling.

Claim 3

A coupling as defined in claim 1 wherein the step is smoothly flared inwardly adjacent and contiguous the first end segment to define a radially extending circumferential groove.

Claim 4

A chimney for channeling the flow of exhaust gases from a heating fixture comprising, in combination: a coupling for joining first and second metallic chimney sections, the coupling comprising an integral body of thin-gage sheet metal formed to have first and second coaxial end segments joined by a step; the first end segment having an external reversely looped hem and being shaped to receive the end of the first chimney section thereover; the second end segment having an internal reversely looped hem and being shaped to receive the end of the second chimney section therein; the step extending substantially radially from the first end segment to the second end segment, thereby providing a common stop for axial travel of the first and second chimney sections when in engagement with the coupling; the first chimney section having a plurality of circumferentially spaced tabs protruding inwardly from the circumference, the tabs being spaced from one end of the first chimney section substantially the same distance as the distance between the hem on the first end segment and the step of the coupling ring; and, the second chimney section having a plurality of circumferentially spaced tabs protruding outwardly from the circumference, the tabs being spaced from one end of the first chimney section substantially the same distance as the distance between the hem on the second end segment and the step of the coupling ring, thereby allowing the cooperation of the tabs and hems to create a locking relationship among the first and second chimney sections and the coupling.

Claim 5

A chimney for channeling the flow of exhaust gases from a heating fixture comprising, in combination: a coupling for joining first and second metallic chimney sections, the coupling comprising an integral body of thin-gage sheet metal formed to have first and second coaxial end segments joined by a step; the first end segment having an external reversely looped hem and being shaped to receive the end of the first chimney section thereover; the second end segment having an internal reversely looped hem and being shaped to receive the end of the second chimney section therein; the step extending substantially radially from the first end segment to the second end segment, thereby providing a common stop for axial travel of the first and second chimney sections when in engagement with the coupling; the first chimney section having a plurality of circumferentially spaced tabs protruding inwardly from the circumference, the tabs being spaced from one end of the first chimney section substantially the same distance as the distance between the hem on the first end segment and the step of the coupling ring; and, the second chimney section having a plurality of circumferentially spaced tabs protruding outwardly from the circumference, the tabs being spaced from one end of the first chimney section substantially the same distance as the distance between the hem on the second end segment and the step of the coupling ring, thereby allowing the cooperation of the tabs and hems to create a locking relationship among the first and second chimney sections and the coupling.

Claim 6

A coupling for joining multi-pipe, metallic chimney sections comprising: a plurality of coaxial rings, each of said rings being characterized by an integral body of thin-gage sheet metal formed to have first and second coaxial end segments joined by a step; each ring having an internal reversely looped hem at one end and an external reversely looped hem at the other end the first step end segments being shaped to receive the ends of a first adjoining multi-pipe section thereover, the second end segments being shaped to receive the ends of a second multi-pipe section therein, the steps providing stops for axial travel of the pipes engaging the rings; and a plurality of spacer means in the form of rigid S-shaped members disposed on a central one of said rings and extending therefrom into contact with each of the inwardly and outwardly adjacent rings to support said rings in spaced relation.

Claim 7

A coupling for joining multi-pipe, metallic chimney sections comprising: a plurality of coaxial rings, each of said rings being characterized by an integral body of thin-gage sheet metal formed to have first and second coaxial end segments joined by a step; each ring having an internal reversely looped hem at one end and an external reversely looped hem at the other end the first step end segments being shaped to receive the ends of a first adjoining multi-pipe section thereover, the second end segments being shaped to receive the ends of a second multi-pipe section therein, the steps providing stops for axial travel of the pipes engaging the rings; and a plurality of spacer means in the form of rigid S-shaped members disposed on a central one of said rings and extending therefrom into contact with each of the inwardly and outwardly adjacent rings to support said rings in spaced relation.