# US 12,004,685 B2 · Food heating apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,685 B2 - Document ID: US12004685B2 - Status: Granted - Kind: B2 - Application number: 17/184,981 - Filed: 2021-02-25 - Published: 2022-08-25 - Granted: 2024-06-11 - Earliest claimed: 2021-02-25 - Applicants: William R. Stumpf; Wendy Stumpf - Inventors: William R. Stumpf; Wendy Stumpf - Web page: https://patentgrep.com/patent/US12004685B2 ## CPC - A47J 36/2483: {with electrical heating means} - B65G 15/34: with reinforcing layers, e.g. of fabric - B65G 23/04: Drums, rollers, or wheels {(B65G23/18 takes precedence)} - B65G 23/44: Belt or chain tensioning arrangements - H05B 1/0263: {Ovens} - H05B 3/26: heating conductor mounted on insulating base {(for transparent areas H05B3/84, H05B3/86)} - H05B 3/64: using ribbon, rod, or wire heater - B65G 2203/0291: Speed of the load carrier - A47J: KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES - B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A food heating apparatus includes a housing, a conveyor assembly, a first heating element, a second heating element, a control unit, and a power source. The housing comprises a base portion and a top portion. The base portion forms a first interior space in which the conveyor assembly is located. The top portion forms a second interior space in which the second heating element is located. The top portion further forms a tunnel. The tunnel comprises an entrance and an exit. The conveyor assembly comprises a belt, a motor, a driving pulley, and a driven pulley. The belt comprises an upper food-carrying run and a lower return run. The control unit comprises a control circuit that is configured to control a speed of the motor. ## Claims ### Claim 1 A food heating apparatus comprising: a housing; a conveyor assembly; a first heating element; a second heating element; a control unit; a power source; the housing comprising a base portion and a top portion; the base portion forming a first interior space in which the conveyor assembly is located; the top portion forming a second interior space in which the second heating element is located; the top portion further forming a tunnel; the tunnel comprising an entrance and an exit; the conveyor assembly comprising a belt, a motor, a driving pulley, a driven pulley, and a tensioning mechanism; the belt comprising an upper food-carrying run and a lower return run; the driving pulley comprising a first cylindrical body and a driving pulley shaft; the driven pulley comprising a second cylindrical body that is substantially of the same diameter as the first cylindrical body and a driven pulley shaft; the motor being electrically connected to the power source and comprising an output shaft which is connected to the driving pulley shaft; the tensioning mechanism comprising a first tensioning assembly and a second tensioning assembly; the first tensioning assembly and the second tensioning assembly being arranged on opposite ends of the driven pulley shaft, respectively; each of the first tensioning assembly and the second tensioning assembly comprising a frame, a movable block, and a spring; the frame of each of the first tensioning assembly and the second tensioning assembly comprising a groove with an expanded section and a reduced section; the movable block of each of the first tensioning assembly and the second tensioning assembly moving linearly in respective expanded section; the movable block of each of the first tensioning assembly and the second tensioning assembly comprising a hole to receive an end of the driven pulley shaft, respectively; the spring of each of the first tensioning assembly and the second tensioning assembly being, at one end, connected to respective movable block; the spring of each of the first tensioning assembly and the second tensioning assembly being, at an opposite end, engaging an end wall of the reduced section; and the control unit comprising a control circuit that is configured to control a speed of the motor. ### Claim 2 (depends on 1) The food heating apparatus as claimed in claim 1, wherein the belt comprises a fiberglass PTFE coated belt. ### Claim 3 (depends on 1) The food heating apparatus as claimed in claim 1, wherein the frame is integrally formed with the housing. ### Claim 4 (depends on 1) The food heating apparatus as claimed in claim 1, wherein the first heating element comprises a thermal insulation plate forming a top surface and a bottom surface and a heating coil, and the heating coil is arranged on the top surface of the thermal insulation plate. ### Claim 5 (depends on 1) The food heating apparatus as claimed in claim 1, wherein the second heating element comprises a thermal insulation plate forming a top surface and a bottom surface and a heating coil, and the heating coil is arranged on the bottom surface of the thermal insulation plate. ### Claim 6 (depends on 5) The food heating apparatus as claimed in claim 5, wherein the heating coil is further arranged on the top surface of the thermal insulation plate, and the food heating apparatus further comprises a warming tray disposed on top of the top portion of the housing. ### Claim 7 (depends on 1) The food heating apparatus as claimed in claim 1, wherein the first heating element is located between the upper food-carrying run and the lower return run. ### Claim 8 A food heating apparatus comprising: a housing; a conveyor assembly; a first heating element; a second heating element; a control unit; a power source; the housing comprising a base portion and a top portion; the base portion forming a first interior space in which the conveyor assembly is located; the top portion forming a second interior space in which the second heating element is located; the top portion further forming a tunnel; the tunnel comprising an entrance and an exit; the conveyor assembly comprising a belt, a motor, a driving pulley, a driven pulley, and a tensioning mechanism; the belt comprising an upper food-carrying run and a lower return run; the driving pulley comprising a first cylindrical body and a driving pulley shaft; the driven pulley comprising a second cylindrical body that is substantially of the same diameter as the first cylindrical body and a driven pulley shaft; the motor being electrically connected to the power source and comprising an output shaft which is connected to the driving pulley shaft; the tensioning mechanism comprising a first tensioning assembly and a second tensioning assembly; the first tensioning assembly and the second tensioning assembly being arranged on opposite ends of the driven pulley shaft, respectively; each of the first tensioning assembly and the second tensioning assembly comprising a frame, a movable block, and a spring; the frame of each of the first tensioning assembly and the second tensioning assembly comprising a groove with an expanded section and a reduced section; the movable block of each of the first tensioning assembly and the second tensioning assembly moving linearly in respective expanded section; the movable block of each of the first tensioning assembly and the second tensioning assembly comprising a hole to receive an end of the driven pulley shaft, respectively; the spring of each of the first tensioning assembly and the second tensioning assembly being, at one end, connected to respective movable block; the spring of each of the first tensioning assembly and the second tensioning assembly being, at an opposite end, engaging an end wall of the reduced section; the control unit comprising a control interface and a control circuit; the control interface comprising a heating control that is configured to receive a user's selection of a speed of the motor; the control circuit being configured to regulate the speed of the motor based on the user's selection. ### Claim 9 (depends on 8) The food heating apparatus as claimed in claim 8, wherein the belt comprises a fiberglass PTFE coated belt. ### Claim 10 (depends on 8) The food heating apparatus as claimed in claim 8, wherein the frame is integrally formed with the housing. ### Claim 11 (depends on 8) The food heating apparatus as claimed in claim 8, wherein the first heating element comprises a thermal insulation plate forming a top surface and a bottom surface and a heating coil, and the heating coil is arranged on the top surface of the thermal insulation plate. ### Claim 12 (depends on 8) The food heating apparatus as claimed in claim 8, wherein the second heating element comprises a thermal insulation plate forming a top surface and a bottom surface and a heating coil, and the heating coil is arranged on the bottom surface of the thermal insulation plate. ### Claim 13 (depends on 12) The food heating apparatus as claimed in claim 12, wherein the heating coil is further arranged on the top surface of the thermal insulation plate, and the food heating apparatus further comprises a warming tray disposed on top of the top portion of the housing. ### Claim 14 (depends on 8) The food heating apparatus as claimed in claim 8, wherein the first heating element is located between the upper food-carrying run and the lower return run.