Abstract: A vacuum heat treating furnace for brazing a large metallic part is disclosed. The vacuum furnace includes a pressure vessel having a cylindrical wall and a door dimensioned and positioned for closing an end of the cylindrical wall. A workpiece handling system is mounted on the pressure vessel door for supporting a metallic workpiece to be heat treated or brazed. The workpiece handling system includes apparatus for rotating the workpiece during a processing cycle. A vacuum system is connectable to the workpiece for creating a subatmospheric pressure inside the workpiece during a brazing cycle.

Abstract: A furnace for heat treating of metal parts includes a hot zone enclosure defining a hot zone therein. The hot zone enclosure has a side wall, a first end wall, and a second end wall. The side wall has slots formed therethrough and along the length thereof. The heat treating furnace also includes a system for injecting a cooling gas into the hot zone through the hot zone enclosure. The heat treating furnace further includes a damper arrangement for directing the cooling gas over a selected portion or portions of the workpiece load and through one or more of the slots. In one embodiment of the invention, all actuated components in the furnace are located outside of the hot zone to minimize damage to moving parts that are caused by exposure to extreme heat.

Abstract: A convection heating system includes a hot zone enclosure defining a hot zone and a plurality of gas injection nozzles for injecting a cooling gas into the heat treatment zone of furnace. Each gas injection nozzle may include a flap disposed and pivotally supported therein for substantially preventing the escape of heat from the hot zone during a heating cycle, but for permitting the injection of the cooling gas into the furnace hot zone during a cooling cycle. A gas exit port may be provided and may include a flap pivotally mounted therein for impeding the unforced outward flow of a gas from the heat treatment zone during a heating cycle.

Abstract: A nozzle for injecting a cooling gas in a vacuum heat treating furnace is described. The cooling gas injection nozzle according to the present invention has a forward portion with a first central opening formed therethrough. The cooling gas injection nozzle also has a rear portion with a second central opening formed therethrough. A flap is disposed in and pivotably supported in the first central opening. The flap operates to substantially prevent the escape of heat from the hot zone during a heating cycle, but permits the injection of the cooling gas into the furnace hot zone during a cooling cycle. The cooling gas injection nozzle is supported from the hot zone wall by any appropriate means. A vacuum heat treating furnace and a hot zone therefor incorporating the cooling gas injection nozzle are also described.

Abstract: A heating element for a vacuum heat treating furnace, a hot zone for a vacuum heat treating furnace, and a vacuum furnace are disclosed. The heating element includes a first heating element portion formed of a thin form of conductive, refractory metal or alloy, and an expansion loop formed in or attached to the first heating element portion, to absorb expansive and contractive forces on the element due to thermal cycling. The heating elements are disposed around the interior surface of the hot zone, which includes a sidewall formed of thermally insulating material. The vacuum heat treating furnace includes a pressure vessel and a hot zone disposed within the pressure vessel.

Abstract: A support or hanger for an electric heating element in a heat treating furnace is disclosed. The heating element support includes a support arm having first and second end portions. First and second ceramic sleeves extend transversely through the support arm and a bracket surrounds at least three sides of the support arm. The bracket is dimensioned and positioned to engage with, and thereby support, the electric heating element. First and second pairs of ceramic spacers are disposed annularly on said first and second ceramic sleeves, respectively. The ceramic spacers are positioned between the bracket and the support arm to prevent contact between the support arm and the bracket. A pin is disposed within each of the first and second ceramic sleeves and extends through the bracket to support and retain the ceramic sleeves, the ceramic spacers, and the bracket on the support arm. In this arrangement, the heating element bears on the metallic bracket and does not cause wear or damage to the ceramic elements.

Abstract: A diffusion bonding furnace includes a pressure vessel having a top and a chamber. A press penetrates through an opening in the top of the pressure vessel, so that a first end of the press is disposed within the chamber. The opening in the top of the pressure vessel is sealed around the press to prevent leakage when the pressure vessel is at a pressure other than atmospheric pressure. A moveable bolster is secured to the first end of the press and a moveable platen is attached to the moveable bolster.