Abstract: An improvement in a high voltage, full-range, current limiting fuse of the type which includes a perforated ribbon main fusible element wound about a gas evolving spider within a sand filled enclosure, and having a portion in intimate contact with a body of low melting temperature alloy, and an auxiliary fusible element whose ends are closely spaced from the main element on opposite sides of the alloy body.The portions of the main element in contact with the alloy body, and adjacent the ends of the auxiliary element are relatively long portions having a uniform cross sectional area less than half the cross sectional area of an unperforated remaining portion of the main element, to thereby reduce the time required for the fuse to clear the low magnitude fault current.

Abstract: A grass trimmer employing a short length of nylon or the like line as the cutting element includes an assembly for removably attaching the line to a rotatable drive member. A hub member is coupled to the drive member for rotation. A post member extends from the free end of and parallel to the axis of rotation of the hub member. A rim portion also formed on the hub member, extends along a portion of the periphery thereof and defines a radially extending aperture therethrough. A length of line to be attached for rotation includes an eyelet connector at one end thereof. The opposite end of the line is received in the aperture in the rim portion so that the line extends radially outwardly from the hub member. The eyelet aperture receives the post member for removably attaching that end of the line to the hub member. A preferred embodiment of the cutting line has a triangular cross section to provide cutting edges extending the length of the line.

Abstract: A venting system for a food processing oven includes a duct assembly comprising a housing defining an inlet into which heated air from the oven enters and first and second outlets through which the heated air is expelled to the interior or exterior, respectively, of the household in which the oven is installed. A serpentine channel formed by a series of parallel plates mounted in the housing between the inlet and outlets is provided to carry the heated air over a relatively long path to cool, permitting water vapor therein to condense on the plates before the air is expelled. A damper plate is mounted in the housing for pivotal movement in the path between the inlet and second outlet. A manual selector movable to first and second positions is coupled to the damper plate for movement thereof to blocking and unblocking positions, respectively, with respect to the second outlet.

Abstract: A combination door handle and security locking system in which the conventional door latch is actuated by turning the five-sided head of an operating shaft with a special socket wrench. A hinge plate having a slot for a padlock bail and a flat index tab on its inner surface is rotated to cover the operating shaft head. The tab must fit against one side of the operating shaft head to allow the hinge plate to be fully closed so that a padlock can be inserted in the bail. The latching mechanism is designed so that this tab will fit against one side of the operating head when the door is fully latched, to thus prevent rotation of the latching mechanism. The free end of the hinge plate has an offset portion which serves both as a sleet hood for the padlock and as a handle for opening the door.

Abstract: A portable electric space heater has a case that surrounds separate electric heating elements, and the case has separated upper and lower airflow openings. A control switch allows manual selection of two different operating cycles, respectively suited for heater use in a large room requiring heater outputs approximately 65 to 100% of maximum to maintain a comfort level, and in a small room requiring heater outputs of only 20 to 100% of maximum. Thermostatic controls respond to the sensed ambient air temperatures to shift the heater operation automatically, in either operating cycle, for maximum heat output, for a lower modulated heat output, and for no heat output. Simultaneously with this modulated heat output, air moving means located in the case is operated at different speeds, at maximum speeds for the high heat outputs and lesser speeds or is even stopped for the lower or no heat outputs.

Abstract: An improved dielectric system for an electrical apparatus. The dielectric system includes a polymeric film impregnated with low molecular weight polybutene having an average number molecular weight in the range of 300 to 500. The dielectric system has improved dielectrical properties and the polybutene is biodegradable which minimizes the pollution of the atmosphere if the dielectric liquid is exposed to the atmosphere. Further extended service life can be achieved by the addition of a cyclohexyl amine to the liquid dielectric.

Abstract: A compact combination vacuum interrupter and visible break disconnect switch, in which the interrupter is electrically connected in series with the disconnect. The interrupter is manually closed, and can be tripped manually or automatically on overcurrent or undervoltage line conditions by a quick make, quick break, trip-free operating mechanism.The disconnect is manually opened or closed by a separate operating mechanism, which is mechanically interlocked with the interrupter operating mechanism so that the disconnect cannot be opened when the interrupter is closed, or the interrupter cannot be closed when the disconnect is open. The disconnect can be padlocked in its open position.The interrupter is mounted integral with the movable contact of the disconnect on a pivotable, insulating support member of the disconnect, with the movable contact rod of the interrupter pivotably connected to the interrupter operating mechanism.

Abstract: A positive-locking cluster mount for supporting electrical transformers and like heavy objects from upright poles characterized by bearing plates held in circumferentially spaced relationship about the pole by adjustable link members and end links each having singular hook ends that engage into the slotted side walls of the bearing plates and are locked into initial loose, though positively connected, positions by the placement of the diverging support brackets thereon. This facilitates the placement of the partially assembled cluster mount at a desired position on the pole and also facilitates the final connection and tightening of the cluster mount thereabout to receive the transformers. The support brackets are assembled in outwardly diverging paired relationship from bearing plates of different lengths to accommodate small and large transformers.

Abstract: The fusible element of a single-element, dual-function, electric fuse is disposed within a passage within a housing of inorganic ceramic material which has a high thermal conductivity; and the major portion of that fusible element is displaced radially from the axis of that passage to be in intimate heat-transferring relation with one side of that passage. Two of the "weak spots" of that fusible element are in close heat-transferring relation with the terminals of that electric fuse; and a portion of that fusible element which is intermediate those two weak spots is in intimate heat-transferring relation with the opposite side of that passage. The resulting transference of heat from that fusible element to that passage enables those two weak spots to continuously carry the rated current of that fusible element even though those two weak spots have very small cross sections, and hence are able to provide desirable current-interrupting action.

Abstract: An out-of-balance and safety switch arrangement for a washing machine or the like device having a movable cover to control access to the clothes receiving tub, and wherein the tub is rotated rapidly to execute a centrifugal extraction cycle, includes a microswitch having an actuator normally biased to an extended position and depressible for energizing the drive motor for the tub and a switch actuator lever arm mounted adjacent the washing machine tub access cover for pivotal movement in first and second generally perpendicular planes with the lever arm being spring biased in the first plane for movement of the first end thereof into operative alignment with the switch actuator, the opposite end of the lever arm being positioned for engagement by the access cover upon closing the latter to move the first end of the lever arm in the second plane into engagement with the actuator for depression thereof.

Abstract: An electrical apparatus, such as a capacitor, having an improved dielectric system. The capacitor includes alternate layers of metal foil and a dielectric material comprising polymeric film, or a combination of polymeric film and paper, which is impregnated with a liquid dielectric composition composed of a mixture of mono-halogenated diphenyl oxide and a mono-halogenated alkyl diphenyl oxide where the alkyl group contains from 1 to 20 carbon atoms in the molecule. The capacitor has improved corona characteristics and low dielectric losses, and the liquid dielectric composition is substantially biodegradable.

Abstract: An electrical capacitor having an improved dielectric system. The capacitor includes alternate layers of metal foil and polymeric dielectric film which is impregnated with a liquid dielectric composition composed of a mixture of mono-halogenated diphenyl oxide and a mono-halogenated alkyl diphenyl oxide where the alkyl group contains from 1 to 20 carbon atoms in the molecule. In processing the capacitor, the capacitor casing is vacuum dried at room temperature and the dielectric liquid is separately agitated under vacuum to remove gas from the liquid. The degassified liquid is introduced into the casing and the liquid is subjected to a vacuum while maintaining the capacitor at room temperature to impregnate the polymeric layers with the liquid. The capacitor has improved corona characteristics and low dielectric losses, and the liquid dielectric composition is substantially biodegradable.

Abstract: A tap-changing transformer system, utilized for voltage regulation of the line potential applied to a load from a source of energy, has a non-arcing switch to protect tap contacts during a tap change. A fail-safe circuit is utilized to determine that the non-arcing switch and its associated circuitry are operating properly before a movable tap contact is transferred from one stationary tap to another. In the event that the fail-safe circuit detects an improper operation of the non-arcing switch, the source is connected directly to the load to preclude the passage of any load current through the tap-changing transformer. A particular form of transfer switch useful in effecting the connection of the source directly to the load employs a current-limiting impedance arrangement.

Abstract: A sandwich grill or similar cooking appliance is disclosed. The sandwich grill is adapted to heat both upper and lower surfaces of a sandwich or other article to be cooked, under controlled conditions. The appliance includes a main housing unit with a lower platen supported thereon, an upper platen, and a heat source for both platens. The upper platen is supported by a mounting arm or the like, for movement between a raised position and a range of lowered positions. In the raised position, sandwiches can be placed on or removed from the grill. The upper platen is mounted so that, in the lowered position thereof, the platen may pivot freely so that its lower surface will engage the upper surface of the sandwich. This permits the upper platen to lie parallel to the lower platen or to the upper surface of the sandwich.

Abstract: The invention relates to hinged supports using torsion bars for the doors of microwave ovens. For light-weight doors, the torsion bars extend beyond the sides of the doors and interlock with the oven structure to constitute the sole supporting means. For heavier doors, the torsion bars are provided with pivot shaft extensions mounted in bearings in the doors, which interlock with the oven structure. The torsion bars are preloaded to bias the doors closed in the light-weight door constructions, and operate in all cases to reduce the dead weight of the doors when in their open, horizontal positions. The side extensions interlockingly engage brackets in the oven structure aided by the weight of the doors, and permit the doors to be lifted readily therefrom.

Abstract: This invention teaches an air distributor accessory device for a breeze box type fan having an annular case and having fan blades supported to rotate within the confines of this case. The accessory device is designed to fit against and be secured to the front face of the fan case, and itself has an annular frame that pivotally supports a plurality of vanes in generally parallel relation. Each vane has a slender profile, and depending on its orientation relative to the direction of the air flow over it can either allow the air to pass straight through or redirect it in a sideways manner. Cross members pivotally interconnected all of the vanes to maintain them generally parallel to one another, and to move them uniformly. A small motor unit is connected to one of the cross members to oscillate the vanes side to side in unison.

Abstract: A method for forming an electrical equipment cover, whose temperature will not appreciably increase when used in an environment of high-strength, time-varying magnetic fields, is provided. The cover is formed from a strong, relatively inexpensive magnetic steel which would ordinarily become heated in such an environment by hysteresis and eddy current losses. In order to prevent this heating, a circular blank or disk of this steel is determined and cut. Selected segments of the blank are removed to form slots in a polygonal pattern concentric with the disk and to form slots along a diameter of the disk or circular blank. All of the slots are filled with strips of a non-magnetic metal, preferably of low electrical resistance, which are then welded to the disk or circular blank. The welds are then ground to smooth the surface of the circular blank. Openings for current-carrying bushings are established in the blank to connect ends of adjacent slots.

Abstract: The improved operating-safety control uses an operating contactor and a safety contactor each having normally open switch contacts and means connect these switch contacts on opposite sides of and in main power series circuits with the electric heating elements of the cooking apparatus effective for controlling electric input to same. An actuating coil is effective for closing each contactor switch contacts, and the control includes an operating thermostat and a safety thermostat each having a heat sensor in the cooking environment and each having a heat sensor in the cooking environment and each having normally closed contacts opened responsive to a set sensed high temperature. The control connects main on and off switch means operatively in series with a parallel hookup connection of the safety contactor actuating coil as one leg and the serially connected operator contactor actuating coil and operating thermostat controlled contacts as the other leg.