Abstract: An improvement in a woodburning stove of the type including an exhaust flue opening; a combustion chamber for primary combustion, having an access door, a support for wood to be burned and a primary air inlet means for supplying primary air to support primary combustion of the wood to produce flue gases containing combustible particulate material; conduit means for directing the flue gases from the combustion chamber to the flue opening in a preselected path; and, secondary combustion means for burning the particulate material in the flue gases before the flue gases pass through the exhaust flue opening.

Abstract: A semi-frameless door, per se, and in combination with a firebox opening and the like, utilizes a specially configured spacer frame to seal inner and outer glass panes and also, if desired, the firebox opening. Retainer plates affixed only to the outer glass ends and the spacer frame permits the outer pane to be curved with longitudinally extending exposed edges flush with the edge of the spacer frame to create a full glass covering of the opening. The glass size differences and black colored spacer frame create a size illusion and a shadow glow reflection when viewing the fire in the firebox. Inner retainer plates sealing the inner glass to the inside surface of the spacer frame have lip edges which are forced into contact with a fibrous seal disposed in a channel configuration within the opening when the door is latched to insure sealing of the opening should the door hinge ever loosen during extended use.

Abstract: An improvement in a woodburning stove of the type including an exhaust flue opening; a combustion chamber for primary combustion, having an access door, a support for wood to be burned and a primary air inlet means for supplying primary air to support primary combustion of the wood to produce flue gases containing combustible particulate material; conduit means for directing the flue gases from the combustion chamber to the flue opening in a preselected path; and, secondary combustion means for burning the particulate material in the flue gases before the flue gases pass through the exhaust flue opening.

Abstract: An improvement in a conversion insert for an existing fireplace cavity of the type having a back wall and outwardly diverging lateral walls providing an access opening. The insert has the normal sheet metal housing with a face plate extending transversely outwardly from the side walls of the housing to form a closure over the access opening in the fireplace. In the improvement, the spaced side walls diverge outwardly from the sheet metal rear wall of the housing to form a relatively large charging opening spaced from the fireplace cavity itself. In addition, there is provided an outwardly protruding convex, exposed front wall extending across the front of the large charging opening to the spaced edges of the face plate so as to block the face plate from view and to create relatively large compartments for blowers and other accessories.

Abstract: Metal parts are spot welded together. To prevent corrosion of the parts a thixotropic, non hardening, corrosion resistant material including a solvent and having a negligible gravity flow at temperatures less than about 400.degree. F to 440.degree. F and forming a heat insulating coherent gel when burnt is used between the plates. The material is known as Anchor Tuflex #23. The parts are clamped and a pressure, higher than a welding pressure that would be used without the material is used to squeeze out the material. The high pressure is continued during welding. After welding continued pressure, is applied during cooling.

Abstract: A method of joining first and second sheet metal parts along a common seam formed from a first surface on the first part and a second surface generally matching the first surface and on the second part. These surfaces define therebetween random spaces of variable thickness when the surfaces are assembled in a generally abutting coextensive relationship.