Abstract: A hot gas defrost system for a refrigeration cycle, including at least a compressor, reversing valve, condenser and evaporator. During defrost, the reversing valve directs the superheated refrigerant from the compressor to the evaporator. The hot gas traverses the evaporator coil which, in turn, causes the ice or frost to melt. The hot gas defrost refrigeration system may also include a receiver to store the refrigerant during the refrigeration and defrost cycles.

Abstract: A hot gas defrost system for a refrigeration cycle, including at least a compressor, reversing valve, condenser and evaporator. During defrost, the reversing valve directs the superheated refrigerant from the compressor to the evaporator. The hot gas traverses the evaporator coil which, in turn, causes the ice or frost to melt. The hot gas defrost refrigeration system may also include a receiver to store the refrigerant during the refrigeration and defrost cycles.

Abstract: A refrigeration system is provided with a receiver and a plate attached to the mouth of the outlet tube of the receiver to prevent the formation of a liquid refrigerant vortex. The mouth of the receiver outlet tube has an enlarged cross-sectional area to decrease the velocity of the liquid entering the tube. A deflector for vertical receiver applications interrupts refrigerant downward flow from the receiver inlet to prevent bubble formation in the liquid.

Abstract: An improvement in a fin and tube heat exchanger of the type used in condensers, evaporators, and fluid coolers in refrigeration systems and the like. The fin and tube heat exchanger comprises at least one coil including fins, tubes and a support. The improved fin and tube heat exchanger has no end plates or center plates by which typically the coils are supported, but the coil of the improved fin and tube heat exchanger is supported solely by the fins thereof resting on the support. The fins of the coils are typically straight along the lower edges thereof from end to end, but alternatively may be notched and a flange formed adjacent each notch to rest upon the support with the support being received in the notch.

Abstract: A refrigerator display case having a plurality of insulated glass window panels mounted in side-by-side relation for pivotal movement about an upper horizontal pivot axis. Each of the window panels has a substantially all glass front appearance, unencumbered by external hardware, trim or moldings. To achieve such appearance, the upper spacer element of the window panel is in the form of a pivot bar completely concealed by an outer glass pane of the panel, but which has an exposed underside mounting surface to which a hinge plate is connected. Each window panel has side sealing members secured to respective side spacers and with a blade portion extending outwardly from the peripheral edges of the glass panes of the window panel for side-by-side sealing engagement with the side sealing members of adjacent window panels when the window panels are in a closed position.

Abstract: A sealed, closed end heat pipe efficiently warms the drain for an evaporator so that condensation may flow unobstructed away from the evaporator in the refrigeration circuit. An evaporator end of the heat pipe is exposed to ambient air and a condenser end is located close to the drain inlet adjacent the evaporator. Thus, no external power source is required as fluid within the evaporator end is heated to vapor phase and circulates toward the condenser end, and cooled fluid from the condenser end returns to the evaporator end.

Abstract: A hot gas defrost system for a refrigeration cycle, including at least one compressor, condenser, receiver, expansion valve and evaporator. During defrost, a pressure-sensitive valve to the condenser inlet is normally closed, and the flow of refrigerant from the compressor bypasses the condenser and flows to the receiver. However, when the pressure in the system reaches a critical point, the pressure-sensitive condenser inlet valve will open to release the excessive pressure. The condenser inlet valve is also temperature-sensitive and will open if the ambient temperature surrounding the condenser is above a specific point. Opening of the condenser valve permits the utilization of the hot gas in the condenser for defrost and to decrease the thermal shock resulting from the superheated vapor contacting the evaporator coil. The compressor, which needs a constant flow of liquid refrigerant for cooling, is continually supplied with liquid refrigerant.

Abstract: Leaks in tube bundles for a heat exchanger are eliminated or minimized by tube interrelated techniques. A floating tube bundle is constructed with separate support elements also secured to the heat dissipating fins and extending through and supported by the support plates. Thin-walled copper tubing similar to that used for the fluid-carrying tubes is used as support tubes, and steel rods are inserted into these support tubes to provide the necessary strength. To minimize leakage in the area where the tube bundle is joined to a header, connector tubes are provided that have one end joined to the header and the other end extending into one of the tubes of the tube bundle sufficiently far that the end of the connector tube passes through the support plate and at least one fin.

Abstract: A commercial refrigerator cabinet is illuminated by fluorescent lamps which are located closely behind insulated glass doors for closing the cabinet. Each lamp is located behind a reflector and is at least partially enclosed by a clear plastic lens having multiple facets on its inner side. The reflector and the lens cause the light emitted from the lamp to reflect and refract in such a manner as to distribute the light substantially uniformly on products located at various distances from the lamp and to reduce glare in the immediate vicinity of the lamp.

Abstract: Circumferentially spaced bosses concentrically position a male tube end within a female tube end. The bosses have a preferred shape which permits molten brazing material to flow evenly between the tubes, ensuring a void-free joint. The bosses provide a relief clearance at the mouth of the male tube to allow the formation of a continuous annular band of brazing material at this end. Stop tapers on the bosses allow the female tube to be pressed onto the male tube for stability prior to brazing. The bosses also limit the overlap of the two tubes to a maximum distance, ensuring adequate heat conduction to the innermost portion of the male tube. Spacers, integral with the bosses, form an axial gap between the tubes into which the brazing rod more readily melts.

Abstract: A multi-pane insulated glass door assembly in which the forward pane of the glass unit extends outwardly a greater distance than the panes rearwardly thereof and is supported by an outer metal frame having a relatively narrow forwardly extending perimeter portion adjacent the peripheral edge of the forward glass pane so as to provide the door with a modernistic, substantially all glass front appearance. In one embodiment, the outer metal frame has a rear portion extending inwardly behind the forward glass pane and a molding is interposed between the forwardly extending perimeter portion of the metal frame and the peripheral edge of the forward glass pane to provide a finished appearance. A dark ink is affixed to an inside peripheral face of the forward glass pane for masking the peripheral components of the door assembly from sight through the forward glass pane from the front side thereof.

Abstract: A device for automatically holding a refrigerator door releasably in a fully open position relative to a refrigerated display cabinet. The device includes an elongated spring arm connected pivotally to a frame member of the cabinet and formed with an elongated slot which receives a pin connected to a frame member of the door. The pin slides in the slot and causes the arm to pivot outwardly as the door is swung open. As the door approaches its fully open position, the pin cams past detent lugs in the slot and then engages the lugs to prevent the door from closing unless the door is swung closed with sufficient force to cause the pin to cam reversely past the detent lugs.

Abstract: A vent plate is attached to the bottom frame member of a door mounting frame of the insulated door assembly of a refrigerator unit. The vent plate includes passages which enable ambient air to be drawn into the cabinet of the refrigerator unit at a controlled location in order to avoid frost build up.

Abstract: A gas spring is connected between a cabinet and a lift-top lid and releasably holds the lid upwardly in a fully open position with respect to the cabinet. Gravity automatically pivots a safety latch into latching relation with the cylinder of the gas spring as the lid approaches its fully open position. If the gas spring loses pressure, the latch operably engages the cylinder to mechanically hold the lid in its fully open position and to prevent the lid from falling toward its closed position.

Abstract: A header machine for drilling specified hole patterns in pipe and for cutting the pipe to a specified length to form headers for use in heat transfer products. The header machine includes hold clamps for selectively holding the pipe during the processing of the pipe and feed clamps for selectively holding the pipe during the feeding thereof through the header machine. The feed clamps are mounted on a feed carriage which is movably mounted for movement forwardly and rearwardly. The feed carriage is driven by a stepper motor operably coupled to the feed carriage for moving the feed carriage and the pipe endwise to various drilling positions. The header machine also includes a spud drill for drilling spud holes in the pipe, a connection drill for drilling connection holes in the pipe, a circular saw for cutting the pipe to a specified length, and provisions for making double circuit patterns of the spud hole.

Abstract: A mechanical expander for tubing for heat transfer products. The tubing expander includes one or more elongated rods, each having an enlargement on the forward end thereof for insertion into tubing to be expanded. The rods are supported on a carriage which in turn is slidably mount on a frame. The carriage is driven forwardly and rearwardly along the frame by a hydraulic motor operably coupled to the carriage by a continuous chain. Elongated tubes which are respectively fixedly attached to a cross member and which respectively partially surround the rods limit lateral or bowing movements of the rods. There are clamping jaws mounted on the frame for clampingly holding the ends of the tubing to be expanded.

Abstract: A refrigerator display cabinet having a front opening and a thermally insulated multiple-glass pane window panel mounted for pivotal movement about a horizontal axis adjacent the upper marginal end of the window panel. The window panel has an internal solid spacer bar adjacent the upper marginal end thereof which permits secure clamping of the window panel by hinge supports without crushing or other damage to the window panel. The hinge supports have a relatively streamlined configuration, which, together with the substantially frameless window panel, provide an esthetic modernistic appearance.

Abstract: A multi-pane insulated glass door assembly in which the forward pane of the glass unit extends outwardly a greater distance than the panes rearwardly thereof and is supported by an outer metal frame having a relatively narrow forwardly extending perimeter portion adjacent the peripheral edge of the forward glass pane so as to provide the door with a modernistic, substantially all glass front appearance. In one embodiment, the outer metal frame has a rear portion extending inwardly behind the forward glass pane and a moulding is interposed between the forwardly extending perimeter portion of the metal frame and the peripheral edge of the forward glass pane to provide a finished appearance. A dark ink is affixed to an inside peripheral face of the forward glass pane for masking the peripheral components of the door assembly from sight through the forward glass pane from the front side thereof.

Abstract: An evaporative condenser having a cylindrical fiberglass housing which provides a circumferential air flow across a plurality of concentrically oriented spiral condensing coils. The planar spiral coils are generated through the compression of a conical winding of tubing formed about a multi-tiered platform, to form an evenly-spaced spiral condensing coil. Each layer of tubing is affixed to a plurality of radial braces, which provide the evaporative coils with sufficient structural integrity to be individually employed. A method and apparatus for producing spiral coils having uniform spacing between adjacent revolutions.

Abstract: A refrigerator door assembly having a door mounting cabinet frame which has a thermally efficient composite design comprising a non-metallic pultrusion-formed structural frame member and an outer metallic trim panel mountable on the structural frame member for providing the desired finished appearance, which may be made consistent with conventional commercial refrigerator and freezer door assemblies. The door mounting frame includes a mullion which also includes a pultrusion formed non-metallic structural element. A rigid plastic molding assembly encompasses the rear and sides of the structural frame members and define air insulating spaces about the frame members. The pultrusion formed frame members permit thermal insulated mounting of metallic accessories by ultrasonic welding methods.