Abstract: A compact level having two spirit level vials visible through either planar face of a triangular body. The vials and triangular body are configured to produce angles including 0.degree., 15.degree., 30.degree., 45.degree., and 60.degree. and their 90.degree. increments. Each of the three edges of the triangle maybe grooved to aid in leveling or truing pipes or other cylindrical objects. Extending along these grooves are magnets. The magnets may be flat or grooved and are used to aid the user when working with magnetic objects.

Abstract: An apparatus for triggering chemical augmented electrical fuses includes a light source which emits a light signal in the form of visible or infrared light energy upon receiving a signal from a control system, trigger signal source or other fuses. The light signal is coupled to a light detector by an optical coupling device such as a fiber optic cable. Upon receipt of the light signal, the light detector generates a signal which causes the application of electrical energy to exothermic material in a fuse, thereby detonating the material and causing interruption of current through the triggered fuse.

Abstract: A level containing horizontal, vertical and rotatable bubble capsules is constructed using only two different housing parts. The main housing is comprised of two identical halves secured back to back. A cylindrical chamber which houses the rotatable bubble is also comprised of two identical halves secured back to back. The structure is simple and economical to produce.

Abstract: A lightning arrester of the station class is equipped with a ceramic housing protective heat shield liner formed of an ablative material capable of giving off a gas when subjected to a fault current arc. The evolved gas contributes to a rapid internal pressure buildup calculated to rupture housing end sealing diaphragms and quickly vent the arrester housing interior to prevent housing fracture. The arrester end structures are provided with expansive radial vents to accommodate unimpeded internal pressure relief.

Abstract: An elongated, insulative tube of high mechanical strength is equipped with fittings at each end for electrical connection with a high voltage transmission line and a grounded tower. An external spark gap is provided between a first arcing ring mounted in electrical connection with one end fitting and a second arcing ring mounted to the tube intermediate its ends and electrically connected with a contact member disposed within the tube. The portion of the tube interior between the contact member and the other end fitting is packed with a series array of varistor discs. The tube maintains the line in spaced relation with the tower, while the varistor array and spark gap absorb voltage surge differentials between the line and tower.

Abstract: A surge arrester including an outer porcelain housing and an ablative heat shield liner is disclosed herein along with a number of techniques for making the surge arrester break resistant. In accordance with one of these techniques, a blow out or relief valve is provided on at least one end of the arrester housing for venting internal pressure due to electrical arcing therein. In this embodiment, an arrangement is provided for preventing the components therein from escaping during the venting procedure. The liner is constructed of a material which is sufficiently ablative to produce its own gas within the housing in response to electrical arcing therein.

Abstract: A surge arrester including an outer elongated housing and an inner liner is disclosed herein. The outer housing is constructed of a material which will not break as a result of internal electrical arcing, specifically a relatively resilient, electrically insulating and non-tracking material which in a preferred embodiment is EPDM rubber. In order to add structural integrity to the arrester, its inner liner is constructed of a high strength material, preferably resin impregnated fiberglass.

Abstract: A high voltage fuse having mounted gas evolving members and method of forming such a fuse are disclosed. The high voltage fuse comprises, in part, a plurality of block shaped gas evolving members attached to a plurality of fuse elements, which, in turn, are wound about a supporting core. The high voltage fuse also has an electrically insulating casing in which is mounted the core having the wound fuse elements and the attached blocks of gas evolving members. The fuse casing is filled with a pulverulent arc quenching filler material. The block shaped gas evolving members have a narrow slit which allows the gas evolving members to be easily slipped over the fuse element so as to cover part or all of a transverse portion of the fuse. The gas evolving members are positioned over the fuse element at locations along the core so that the block type gas evolving members are arranged between adjacent portions of the ribs of the core.

Abstract: A high voltage current limiting fuse of the type including a bound silica sand filler has a fusible element provided with evenly spaced perforations along its major length. In the region of the center of the fuse, a segment of the element is provided with additional perforations. At least one of the perforations in the segment has a lead-tin alloy overlay directly adjacent its perimeter which, in conjunction with the additional perforations, lowers the low current clearing level of the fuse.

Abstract: Method of producing plates having an identical configuration of valleys and lugs thereon so that one plate is interchangeable with another. Flat plates are provided with a pair of individual holes at opposite ends of the plate center line. Thereafter one or more valleys are machined in a predetermined spacing and location from one or both of the locating holes, and the process repeated for a plurality of plates. Lugs are produced by matching one plate with another by means of pins inserted into the locating holes, and injecting a hardenable material into the valleys. This hardenable material is bonded to the opposite plate. The machining operation of the valleys is carried out in a manner to produce randomly spaced ridges along the side surfaces of the valleys which form depressions in the side surfaces of the lugs that are cast therefrom. Molds made from the respective pattern plates have valleys with ridges therein which have an interference fit with respect to lugs of a matching mold.

Abstract: The fuse is of the type including an electrically insulating cartridge, a pair of electrically conductive terminal caps at opposite ends of the cartridge, a fusible element within the cartridge in electrical contact with the terminals, and a self-supporting bound matrix filler of arc-quenching particulate matter. The improvement comprises that one of the terminal end caps has a filter disposed on its inside end surface over a drain port.Also disclosed is a method of manufacturing a fuse. The method comprises the steps of assembling the components, packing with arc-quenching particulate matter, filling with a suspension of colloidal silica, removing excess suspension, and drying. In filling, the colloidal silica suspension is forced into a fill port in one end cap and released through a drain port in the other end cap. Before passing out through a drain port in the other end cap, the suspension passes through a filter disposed on the inside end surface of the end cap and overlapping the drain opening.

Abstract: A two part bushing or guide pin for aligning foundry flasks, hot boxes, and the like comprising: a machinable body portion having external threads for threading into a flask, hot box, etc., and internal threads for receiving either a hardened nonmachinable guide ring or a hardened nonmachinable guide pin.In the case of the hardened nonmachinable guide ring, the outer surfaces are provided with hardened ground threads adapted to be threaded into the internal threads of the main body portion. Suitable means is provided for locking the ring in angular relationship with the body after it is threaded therein. The construction permits the main body portion of the bushing to be firmly seated and locked in a flask, etc., following which the hardened ring can be rotated within the main body portion until its surfaces are accurately angularly positioned relative to the flask, and the ring then locked to the bushing.

Abstract: The fuse is of the general purpose type having a casing closed at the ends by terminal caps; a core inside the casing; a main fusible element wound about the core and connected between the caps; a pair of arcing clips mounted in spaced relation on the core adjacent the main fusible element; and, an auxiliary element also wound about the core and connecting together the arcing clips. The improvement comprises a nonporous dielectric sheet covering the exposed surface of the clips and being interposed between and in contact with the clips and the main fusible element for determining the arc gap between them.

Abstract: The fuse is of the general purpose type having a casing closed at the ends by terminal caps; a core inside the casing; a main fusible element wound about the core and connected between the caps; a pair of arcing clips mounted in spaced relation on the core adjacent the main fusible element; and, an auxiliary element also wound about the core and connecting together the arcing clips. The improvement comprises that segments of the main element passing over the arcing clips are provided with additional reduced cross-sectional necks for improving the melting response of the element upon arcing between the element and the clips.

Abstract: The fuse is of the type including an electrically insulating cartridge, a pair of electrically conductive terminal caps at opposite ends of the cartridge, a fusible element within the cartridge in electrical contact with the terminals, and a self-supporting bound matrix filler of arc-quenching particulate matter. The improvement comprises that one of the terminal end caps has a filter disposed on its inside end surface over a drain port.Also disclosed is a method of manufacturing a fuse. The method comprises the steps of assembling the components, packing with arc-quenching particulate matter, filling with a suspension of colloidal silica, removing excess suspension, and drying. In filling, the colloidal silica suspension is forced into a fill port in one end cap and released through a drain port in the other end cap. Before passing out through a drain port in the other end cap, the suspension passes through a filter disposed on the inside end surface of the end cap and overlapping the drain opening.