Continuous heat treating vacuum furnace

A vacuum furnace for heat treating work parts in a subatmospheric environment in a heating chamber of said furnace, comprising a housing in which said heating chamber is located, a loading station located forwardly of said heating chamber for receiving work parts therein prior to the transfer of said work parts to said heating chamber, a cooling station communicating with said heating chamber, a discharge station communicating with said cooling station, means for transferring said work parts from said loading station and into said heating chamber and for transferring said work parts from said heating chamber to said cooling and discharge stations, and a plurality of door assemblies for sealing communication between adjacent stations during the processing of said work parts in said furnace, at least one of said door assemblies including a fixed frame having an exterior sealing surface and defining an opening for communication with an interior zone, a plate-like door member mounted for movement relative to said frame and having an inside and an outside surface, a sealing member mounted on the inside surface of said door member adjacent to the marginal edges thereof, so that said sealing member positively engages the sealing surface of said frame when the door member is in the closed position on said frame for sealing said door member thereto, and means operatively connected to the other surface of said door member for simultaneously moving said door member from the closed sealed position in a vertical and rotating motion to an open upper horizontal position, wherein said inside surface of said door member and said sealing member mounted thereon face upwardly and are remote from said interior zone, and said outside surface of said door member faces downwardly and defines a buffer for said sealing members against high temperatures emanating from said interior zone.

A vacuum furnace for continuously introducing and processing work parts through a heating chamber of the furnace for the heat treatment thereof without breaking the vacuum in said heating chamber, comprising a housing in which said heating chamber is located, a loading station including a loading chamber located forwardly of said heating chamber for receiving work parts therein prior to transfer to said heating chamber, a cooling station located rearwardly of said heating chamber and communicating with a discharge station located at the rear of said housing, a first door assembly located at the forward end of said housing for sealing said loading chamber from atmosphere, a second door assembly located between said loading chamber and heating chamber for sealing communication therebetween, a third door assembly for sealing said cooling station from atmosphere, and a fourth door assembly sealing communication between said heating chamber and said cooling station, a series of tracks located in spaced relation at said loading station, heating chamber, cooling station and discharge station, a cart on which said work parts are carried for travel on said tracks, a first transfer means for moving said work cart from said loading station into said heating chamber at predetermined intervals, and a second transfer means operated independently of said first transfer means for removing said work cart from said heating chamber for transfer to said cooling station and for transfer to said discharge station, said transfer means including an elongated flexible spring on the end of which a transfer element is secured, gear means engaging said spring for producing linear movement thereof, means for rotating said gear means, and means for urging said spring into intimate engagement with said gear means for effecting a positive drive therebetween, said urging means including a roller that is contoured to snugly engage said spring for urging it into intimate contact with said gear means, means for pivotally moving said roller downwardly against said spring to temporarily retain said spring in a depressed position relative to said gear means so as to enable said cart to move into said loading chamber forwardly of said detent prior to the transfer operation of said cart into said heating station, said spring being releasable to locate said detent in engagement with a portion of said cart, wherein said transfer element and spring joined thereto are movable in a linear direction for moving said cart.

A vacuum furnace for continuously introducing and processing work parts through a heating chamber of the furnace for the heat treatment thereof without breaking the vacuum in said heating chamber, comprising a housing in which said heating chamber is located, a loading station including a loading chamber located forwardly of said heating chamber for receiving work parts therein prior to transfer to said heating chamber, a cooling station located rearwardly of said heating chamber and communicating with a discharge station located at the rear of said housing, a first door assembly located at the forward end of said housing for sealing and loading chamber from atmosphere, a second door assembly located between said loading chamber and heating chamber for sealing communication therebetween, a third door assembly for sealing said cooling station from atmosphere, and a fourth door assembly sealing communication between said heating chamber and said cooling station, a series of tracks located in spaced relation at said loading station, heating chamber, cooling station and discharge station, a cart on which said work parts are carried for travel on said tracks, a first transfer means for moving said work cart from said loading station into said heating chamber at predetermined intervals, and a second transfer means operated independently of said first transfer means for removing said work cart from said heating chamber for transfer to said cooling station and for transfer to said discharge station, said first transfer means including an elongated flexible spring on the end of which a transfer element is secured, gear means engaging said spring for producing linear movement thereof, means for rotating said gear means, and means for urging said spring into intimate engagement with said gear means for effecting a positive drive therebetween, means for reversing rotation of said rotating means in accordance with a predetermined linear movement of said spring, wherein the spring is retracted to its original position in preparation for transferring another cart to said heating chamber, said reversing means including a switch electrically interconnected to said rotating means, an elongated rod engageable with said switch means and being responsive to linear movement of the spring that transfers the cart to said heating chamber to reverse the operation of said rotating means, wherein said transfer element is retracted in preparation for the next cart feeding operation.

A vacuum furnace for continuously introducing and processing work parts through a heating chamber of the furnace for the heat treatment thereof without breaking the vacuum in said heating chamber, comprising a housing in which said heating chamber is located, a loading station including a loading chamber located forwardly of said heating chamber for receiving work parts therein prior to transfer to said heating chamber, a cooling station located rearwardly of said heating chamber and communicating with a discharge station located at the rear of said housing, a first door assembly located at the forward end of said housing for sealing said loading chamber from atmosphere, a second door assembly located between said loading chamber and heating chamber for sealing communication therebetween, a third door assembly for sealing said cooling station from atmosphere, and a fourth door assembly sealing communication between said heating chamber and said cooling station, a series of tracks located in spaced relation at said loading station, heating chamber, cooling station and discharge station, a cart on which said work parts are carried for travel on said tracks, a first transfer means for moving said work cart from said loading station into said heating chamber at predetermined intervals, and a second transfer means operated independently of said first transfer means for removing said work cart from said heating chamber for transfer to said cooling station and for transfer to said discharge station, said housing including an inner tubular shell and an outer shell having a configuration that is rectangular in cross section, the inner shell being located within the outer shell, the outer shell defining a cooling jacket around the inner shell, wherein a cooling fluid is circulated therebetween, a corner of the space as defined by said inner and outer shells having a wall extending longitudinally therein to define a hydraulic fluid cooling space, and means for continuously circulating hydraulic fluid used to operate various motors associated with said furnace through said cooling space in heat exchange relation therewith.