# US 4,461,273 A · Stove > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,461,273 A - Document ID: US4461273A - Status: Granted - Kind: A - Application number: 06/271,853 - Filed: 1981-06-09 - Granted: 1984-07-24 - Earliest claimed: 1981-06-09 - Assignees: Kent Heating Limited - Inventors: Anthony M. Barker; Robert N. Lockhart - Web page: https://patentgrep.com/patent/US4461273A ## CPC - F24B 5/028: {Arrangements combining combustion-air and flue-gas circulation} - F23B 5/02: {in main combustion chamber} - F23M 11/02: Preventing emission of flames or hot gases, or admission of air, through working or charging apertures - F23M 11/042: {Viewing ports of windows} - F24B 13/004: {Doors specially adapted for stoves or ranges (doors for open fires F24B1/192)} - F24B: DOMESTIC STOVES OR RANGES FOR SOLID FUELS (for solid fuels in combination with gaseous fuels, liquid fuels or other kinds of energy supply F24C1/02); IMPLEMENTS FOR USE IN CONNECTION WITH STOVES OR RANGES - F23B: METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL (for combustion of fuels that are solid at room temperatures, but burned in melted form, e.g. candle wax, C11C5/00, F23C, F23D; using solid fuel suspended in air F23C, F23D1/00; using solid fuel suspended in liquids F23C, F23D11/00; using solid fuel together with fluid fuel or with solid fuel suspended in air, simultaneously or alternately, F23C, F23D17/00) - F23M: CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR ## Abstract A slow combustion stove having a transparent portion to enable vision into a primary combustion zone so that flames are visible in use has a double burning combustion chamber defined by the primary combustion chamber and a partitioned off secondary burning combustion chamber, an air inlet to enable air to circulate within the stove adjacent a deflector which deflects the incoming air over the transparent portion to cool and resist staining and soot build-up thereon. A majority of the air passes to the primary combustion zone and a proportion of further gases enter the secondary combustion chamber with the gases of primary combustion for combustion of smoke and other unburned gases. A by-pass is provided for by-passing the normal combustion flow path when lighting the stove and additionally, an interlock is provided for preventing accidental opening of a door into the stove while the by-pass is closed, said by-pass damper is jamming resistant and acts as a pressure relief valve by virtue of the provision of a damper head to float and rotate relative to its mounting and support. ## Claims ### Claim 1 In a stove including a casing surrounding a combustion zone, a door in one wall of the casing, an air inlet in an upper region of the casing, a deflector in conjunction with said air inlet to deflect air within said casing past a transparent portion in a front face of said casing and to an outlet from said casing, a partition within said casing adjacent said outlet, said outlet being situated in said upper region of said casing remote from said transparent portion and said partition extends from the region of the outlet towards said transparent portion, so that in use, combustion air is drawn down inside the casing from the air inlet toward a primary combustion zone, past at least a portion of the transparent portion and then along the underside of the partition before passing by the partition into a secondary combustion zone and to the outlet, and a by-pass aperture in said partition and adjacent said outlet and closeable by a movable by-pass damper, the improvement comprising said damper is adapted to substantially float relative to said aperture so that it can be lifted away from and into and out of closing relationship with said by-pass aperture, and means to bias said damper toward said aperture, a movable control rod conncted to said damper to remotely operate said damper, the connection between the damper and the control rod comprising the damper being mounted upon the control rod with a tolerance for limited floating movement of the by-pass damper relative to the control rod, and an interlocking means to lock said door in a closed position when said by-pass aperture is closed by said damper comprising a movable finger mounted on said casing, and a cam portion on said control rod operatively engaging said finger so that said finger is movable by said cam portion into and out of interlocking engagement with a portion of the door. ### Claim 2 (depends on 1) A stove as claimed in claim 1 and further comprising a locking finger mounting bracket on said casing, said locking finger being slidably mounted on said bracket so that one end is removably engageable with said door locking member and the other end slidably engages with said control rod cam portion, said cam portion comprising a part of said control rod between said bracket and said damper extending at an angle with respect to said control rod, so that upon movement of said control rod outwardly of said stove said damper is moved off of said by-pass aperture and said locking finger is moved out of locking engagement with said door locking member, and upon movement of said control rod inwardly of the stove with the door closed the damper moves into closing position with respect to said by-pass aperture and said locking finger engages in locking position with said door locking member. ### Claim 3 (depends on 2) A stove as claimed in claim 2 wherein said air inlet is positioned above said door and wherein said transparent portion is in said door. ### Claim 4 (depends on 1) A stove as claimed in claim 1 wherein the stove includes a heat exchanger for convection of air. ### Claim 5 (depends on 1) A stove as claimed in claim 1 wherein at least one baffle is positioned between said partition and said casing. ### Claim 6 (depends on 1) A stove as claimed in claim 1 wherein at least one baffle is provided with a plurality of spaced apart apertures therein, through which the gases of combustion and unburned gases pass to proceed into said secondary combustion zone.