Abstract: A mechanical refrigerant expansion valve meters the flow of refrigerant therethrough in one direction through an orifice that varies in cross-sectional area as a function of the pressure differential across the valve. The same valve controls refrigerant flow in the other direction through a fixed area metering orifice.

Abstract: A flow metering device for use as an expansion valve in a heat pump system includes a body having a flow passage extending therethrough. A piston having a flow metering port extending therethrough is moveably positioned within the flow passage. An elongated member extends through the metering port of the piston and is axially and radially fixed within the body. The elongated member has a central portion which cooperates with the metering port to prevent flow through the port when axially aligned with it. The elongated member has flow metering configurations formed thereon on both sides of the central portion. The piston is spring biased into alignment with the central portion. Refrigerant flow in either direction through the device results in movement of the piston against a spring force into a flow metering relationship with one of the metering configurations.

Abstract: A refrigerant expansion device for use in a refrigeration system includes a body having a flow passage extending therethrough. A piston having a flow metering port therethrough is moveably mounted within the flow passage. A flow metering rod is supported within the housing and extends through the flow metering port. The flow metering rod and the flow metering port cooperate to define a flow metering passage between them. The flow metering rod is configured so that the cross sectional area of the metering passage varies relative to the axial position of the piston with respect to the rod. The piston is spring biased and the piston moves relative to the rod as a function of the pressure differential across the piston.

Abstract: An internally compounded two-stage compressor has an interstage cooler and an oil separator associated therewith. The oil, and any hot gas mixed with it, discharged from the oil separator is passed in heat exchanger relationship with the cooling refrigerant flowing into the interstage cooler.

Abstract: A refrigerant flow metering device which varies the expansion area of the device in response to the differential pressure between refrigerant in the high and low pressure sides of a refrigerant system. The expansion device includes a housing with a flow passage extending therethrough which is divided into a high pressure portion and low pressure portion by a partition. The partition has a flow metering port which extends therethrough and interconnects the high and low pressure portions. An elongated member extends through the flow metering port and cooperates with the flow metering port to define a refrigerant flow metering passageway therebetween. The elongated member is configured to vary the cross-sectional area of the flow metering passage in relation to the position of the elongated member to the flow metering port.

Abstract: A refrigerant flow metering device for use in a refrigeration system includes a housing having a flow metering passage extending therethrough. A partition is located within the flow passage of the housing and defines a flow metering port therethrough. The partition divides the flow passage into a high pressure and a low pressure portion. An elongated member extends into the metering port. The elongated member and the metering port cooperate to define a flow metering passage therebetween. The elongated member is configured to vary the cross-sectional area of the flow metering passage in relation to the position of the elongated member to the flow metering port. One end of the elongated rod extends into the low pressure portion of the flow passage.

Abstract: An enclosure is provided for an inground swimming pool. The enclosure is a building like structure made up of vertical sidewalls including a fence portion and a ventilating window portion. The roof is made from a transluscent plastic supported on a skeleton-like framework.

Abstract: A current limiting cartridge fuse having a portion of restricted diameter in one end cap, which serves as a rejection feature, is provided with an insulating insert which cooperates with the fuse casing and the one end cap to allow an active portion of a short circuit element to be located in the restricted diameter portion of the end cap.

Abstract: A fillerless electric fuse having a wire-like fusible element is provided with a body of thermoplastic material which cooperates with the fusible element to establish an impermeable barrier within the fuse between the fuse end terminals. The thermoplastic material is preferably a hot melt adhesive introduced into the casing in a fluid state.

Abstract: A holder for an electric fuse is provided with apparatus which senses the flow of electric current along the current path of the fuse holder, and, which responsive to such sensing, electromagnetically induces an ascertainable signal. The signal may be detected and processed to provide an indication of whether current is flowing through the fuse holder.

Abstract: An electric fuse is provided with heat dam elements interconnecting the fusible element and the fuse end terminals, which are provided with one or more raised ribs integrally formed therein. The heat dams include a plurality of planar sections and interconnecting bends to which the ribs impart a high degree of stiffness and dimensional stability.

Abstract: A fillerless electric fuse having a tubular casing with open ends is provided with a fusible element in the form of an extremely fine wire extending from one of the open ends to the other. The casing is provided with a pair of annular sections of reduced diameter at opposite ends thereof which receive a pair of metal contact rings having an outside diameter substantially the same as the outside diameter of the fuse casing. The fusible element extends through each of the open ends of the casing and is welded into electrically conductive relationship with the axially outwardly facing surfaces of the respective metal contact rings. End terminals are press fitted over each of the metal contact rings and are permanently secured to the fuse casing. Means are provided inside the fuse to establish an impermeable barrier of insulating material within the fuse casing around the fusible element and between the end caps.

Abstract: An electric cartridge fuse having a channel shaped fusible link section which carries a gas evolving core is provided with means for assuring positive axial positioning of the core without requiring deformation of the fuse link. The gas evolving core is provided with a lateral protrusion which extends through and operatively engages one of the perforations in the fuse link thereby positively axially positioning the core with respect to the fuse link.

Abstract: A holder for an electric fuse is provided with a Hall-effect sensor arrangement which is integrally mounted in the fuse holder in close proximity to the current path through the holder. The Hall-effect sensor provides an output voltage responsive to the magnetic field resulting from the flow of current along the current path. The output from the Hall sensor is then processed to provide an indication of whether current is flowing through the fuse holder.

Abstract: An electric plug fuse of the type wherein one end of the fusible element is retained in a channel between the insulating body of the fuse and an outer metal shell is provided with a geometrically configured fusible element which allows extremely thin elements to be used while maintaining a high level of structural and electrical integrity in the fuse.

Abstract: An electric low-voltage current-limiting fuse completely or substantially complying with the Underwriters Laboratories Inc. Standard Class R fuses. The current carrying part of the fuse comprises a fusible element having serially arranged perforations. This part may be of silver or of copper. The current carrying part of the fuses further comprises tabs of copper bent over the rims of the casing and conductively interconnecting the ends of the fusible element with the terminal caps of the fuse. The fusible element is provided with an M-effect metal to limit the temperature rise of the fusible element and of the casing. The tabs are considerably thicker than the fusible element. If the fusible element is of silver the thickness of the tabs of copper is larger than the thickness required to fully compensate for their higher resistivity.

Abstract: An electric fuse is provided with a blown fuse indicator mounted on a lateral wall of the fuse. One of the end terminals of the fuse is provided with a first opening therein in a surface which faces the interior of the fuse casing. The same end terminal is provided with a second opening therein which is in a peripheral surface of the terminal and which lies in a plane which is substantially parallel to the longitudinal axis of the fuse casing. The end terminal is further provided with an internal passageway therein which communicates the first and second openings. The fuse casing is provided with an opening therein which is in axial alignment with the second opening in the end terminal.A spring loaded blown fuse indicator is mounted through the opening in the fuse casing and is fixedly and conductively engaged with at least a portion of the end terminal passageway.

Abstract: An electric plug type fuse. The hollow glass body thereof contains a strip-like spring conductively connected to the bottom contact in the insulating tip of the fuse. Said spring is arcuate and has a center of curvature situated at the side of the spring where the longitudinal axis of the glass body is located. A solder joint preferable of a eutectic metal connects the end of the spring remote from the bottom contact to a fusible element capable of interrupting short-circuit-like currents, i.e. a ribbon type fusible element having at least one point of reduced cross-section. The aforementioned spring and the fusible element enclose an angle of approximately 90 deg. and the end of the fusible element remote from said spring is conductively connected to a screw shell. The spring puts the fusible element under tension and is released from it when the solder joint connecting both parts melts.

Abstract: An electric fuse having a support for helically wound fusible element or elements. The support includes a plurality of rods which are supported at their opposite ends adjacent the fuse end terminal by rod supports each of which is made from a pair of angularly arranged sheet-metal channels. The channels have a U-shaped cross-section and are arranged with their open ends facing the center of the fuse housing. Centrally positioned sections of the channels are flattened to facilitate rigid attachment of the channels to one another. The ends of the rods are received in and attached to interior portions of the U-shaped channels. A sub-assembly comprising the rods, rod supports and the wound fusible elements is pre-assembled and, when placed in a fuse housing, the ends of the channels cooperate with the inside walls of the housing to properly position the entire assembly.

Abstract: A fusible element for electric fuses including a core or layer of copper, an outer layer of silver plating, and an M-effect overlay on the silver layer of a low fusing point metal, e.g. tin, capable of severing the current path through the plating of silver and the core of copper by a metal diffusion process.The M-effect overlay is arranged in spaced relation in regard to the point of the fusible element where the highest temperature prevails to maximize the temperature difference, or temperature gradient, between the M-effect overlay and the hottest point of the fusible element when the latter is carrying current.