Abstract: An improved telephone protector module for individual subscriber circuits of generally planar configuration, and having heat-sensitive means employing a solder pellet which, upon melting, flows through capillary action to effect a shorting to ground. Secondary air gap means is provided by spacing a pair of conductive parts using a thin insulative wafer having openings therein forming an interruption in the insulation.

Abstract: An improved dynamic current interruption-type flashover indicator responsive to lightning strikes for releasing from the tip of arc horns located on power transmission towers and for interrupting the resulting dynamic current. The present invention utilizes a uniquely designed propellant having a formed center hole extending the longitudinal length of the propellant and containing therein a fuse wire extending from a separation plate at one end and engaging an inserted pin at the other end. When lightning strikes, the resulting arc is lead into and throughout the formed center hole by the fuse wire, the fuse wire melts and the temperature of the arc causes the propellant to vaporize uniformly into steam and the resulting gaseous force causes the indicator to become rocket-like and to suddenly leave the tip of the arc horn.

Abstract: An overvoltage protection device, for protecting communications equipment against hazardous voltages cue to lightning or power surges, comprises a primary protector, for example a gas tube device, and a back-up protector connected in parallel. The back-up protector includes a semiconductor pn junction, and is preferably a pair of diodes back-to-back. The back-up protector has a breakdown voltage slightly higher than that of the primary protector and is arranged to fail short-circuit once it has operated so as to provide an indication that the primary protector failed to operate.

Abstract: A device for protecting the secondary winding of a current transformer against destructive or dangerous overvoltages when connected across the secondary, has a transparent tubular casing with a stud support and conductive stud within one end. The stud is threadably mounted in the stud support so it can be adjusted longitudinally and it has an arcing surface on its inner end. Within the other end a support member carries a longitudinally sliding conductive plunger. The plunger is biased inwardly towards the arcing surface of the stud but it is restrained from inward movement by a fusible element which engages it and restrains it. The fusible element forms another arcing surface spaced a predetermined distance from the arcing surface on the stud. One terminal is provided on the outer end of the conductive stud and another on the outer end of the support member connected to the plunger by a flexible braid. A small overvoltage of short duration causes an arc current to flow to limit the voltage.

Abstract: A surge protector with first and second electrodes, with a heat sensitive member and with a contact member which is electrically connected with the first electrode and which is mounted so as to be brought into contact with the second electrode upon the temperature of the heat sensitive member reaching a predetermined value when receiving heat from the protector. In an embodiment, the heat-sensitive member is composed of a material whose shape is a function of its temperature, such as a shape memory alloy. The heat sensitive member can also serve as the contact member.

Abstract: A subscriber pair protector module of gas tube type in which the heat coil assembly is supplemented by the provision of a planar fusible member placed in direct contact with the gas tube elements to provide a heat sink for a limited period of time to protect the module until the heat coil assembly becomes operative, thereby preventing damage to the synthetic resinous housing element of the module which would interfere with its subsequent removal. An improved gas tube element is also disclosed having recesses disposed in the end surfaces thereof to prevent total shorting action by the heat coil element until the planar fusible member has melted. An improved gas tube element is also disclosed having recesses disposed in the end surfaces thereof to prevent total shorting action by the heat coil element until the planar fusible member has melted.

Abstract: A shorting cage is provided in a telephone terminal housing having a protector well so that when the protector cartridge is removed from its cooperating well, the shorting mechanism in the form of a cage will cause the line to remain shorted until a replacement protector cartridge, with the protective device included therein, is reinserted into the terminal well. Replacing the protector cartridge into the well without a protective device disposed therein will not remove the line short.

Abstract: A low voltage valve type arrester device for connection between a domestic electric supply line and earth includes a varistor, a switching device and an encapsulated gas discharge voltage arrester connected in series. The switching device includes two switch members connected together by a solder connection and biased apart by a spring. A fusible link is connected to the two switch members in parallel with the solder connection. When a voltage surge occurs, current flows through the arrester to earth. If the surge is large enough to render the gas discharge arrester continuously conductive, the solder connection melts due to the heat dissipated in the varistor and the two switch members move rapidly apart. The fusible connection rapidly melts by which time the switch members are sufficiently far apart for no arc to form between them.

Abstract: A power converter adapted for use in a high-voltage circuit and equipped with a plurality of arms each comprising a plurality of thyristor elements connected in series, wherein an overvoltage limiter having an overvoltage limiting element and means for short-circuiting the ends of the overvoltage limiting element in response to flow of a load current therein are connected between the anode and the cathode of each thyristor element. The short-circuiting means has a gap between the two electrodes connected respectively to the anode and the cathode of each thyristor element, and also a metal layer of a low melting point which is molten by heat generated due to the flow of a load current in the overvoltage limiting element to fill the gap.

Abstract: A fused station protector is disclosed wherein the fuse links have precisely controlled fusing characteristics. A shrink away foam element (28) encloses a portion of the fuse link (26) to provide a potential hot spot for slight current excesses. The remainder of the fuse link is in contact with arc quenching material (27) for extinguishing potential power arcs. Thus, the protector provides a precise fusing characteristic for slight current excesses and arc quenching capability for severe current excesses.

Abstract: A device for connection to lightning arresters isolates the grounded lead and contains the resulting spark or arcing flame, including any hot particles generated when ground disconnection is made due to excessive current flow through the arrester. A central spacer member is screwed onto the existing ground lead terminal of the lightning arrester and contains an arc extinguishing channel with an internal fusible link adapted to melt in an overload condition. A shielding cup surrounds the central spacer member for containment of sparks and arcing, and a ground lead connector wire extends from the internal fusible link to a new ground lead terminal at the exterior of the shielding cup, for connection to a grounded lead.

Abstract: A line protector for a communications circuit provides overvoltage and overcurrent protection. The overvoltage protection is attained through an arrester that provides an arc gap from the line to ground. For overcurrent protection, a fusible element is melted by a heat coil causing the line to be directly grounded. A test terminal is in conductive connection with the line circuit and extends to a region in the housing wall wherein there is an aperture for receiving a test probe. The test terminal is in firm resilient engagement with a conductive component of the line circuit and the wall adjacent to the apertures whereby the test terminal is maintained in its desired position within the housing to avoid short circuits therein.

Abstract: A surge voltage arrester assembly includes a threaded tubular housing member coupled to circuit ground and including therein an axially aligned compression spring, metallic cage with extending resilient fingers, a solder pellet, a gas-filled tube having a primary arc gap and insulator means with secondary arc gap holes separating a pair of electrically conductive members contacting the gas-filled tube and metallic cage respectively.

Abstract: An excess voltage arrester of the kind comprising a gas-filled enclosure having an electrode structure (1, 11, 13) within the enclosure which defines at least one discharge gap. A portion of at least one electrode (13) is adapted to melt on overheating of the arrester so as to take up a generally spherical form (19) under the action of surface tension and thereby contact another electrode (1).

Abstract: Overload by-pass conductor with an external short circuit heat conduction path, including an outer wall of the overload by-pass conductor, two electrodes, one of the electrodes being a counter electrode, a contact surface connected to the counter electrode, a metal carrier being disposed along the outer wall and being electrically conductingly connected to one of the electrodes, and a solder piece being in a mechanically fixed connection with the metal carrier and being adjacent the contact surface, the solder piece being spaced from other parts of the overload by-pass conductor in an operating state, and the solder piece being deformable for causing an external short circuit upon the occurrence of an overload, the external short circuit being triggered after a delay with respect to the beginning of the overload due to the heat conduction path.

Abstract: A surge voltage arrester assembly for protection of communications lines from over voltage and excess current conditions includes a sealed cold cathode gas tube forming a primary arc gap and disposed within a cage member with an insulator member disposed between the gas tube and an electrical conductor forming a secondary arc gap sealed from contaminants, in parallel with the primary arc gap and affixed onto a cylindrical conductor by a retainer means.

Abstract: Overvoltage arrester having a gas-filled housing, including two overvoltage arrester electrodes disposed across from each other in the housing, a tubular insulator body spacing the overvoltage arrester electrodes apart from each other, a ring-shaped flange integral with one of the overvoltage arrester electrodes forming a first spark gap electrode, a ring-shaped metal cap forming a second spark gap electrode being superimposed on the first spark gap electrode and pressed in on the tubular insulator body, the first and second spark gap electrodes forming a spark gap having a given clearance therebetween, and a contact spring connecting the second spark gap electrode to the other of the overvoltage arrester electrodes.

Abstract: Apparatus for preventing a fire in electrical equipment when a relatively constant overvoltage condition appears on an input line comprises a meltable fuse in the line and a surge arrestor connected between the equipment side of the fuse and ground. The surge arrestor is physically located adjacent the fuse for melting the latter and open circuiting the line when the overvoltage condition is present for greater than a net prescribed time interval. In a preferred embodiment, the line adjacent the electrical equipment is a printed conductive line on one side of a circuit board, with the fuse comprising a gap in the printed line that is bridged with a bead of solder. The surge arrester is located under the solder bridge, with one of its leads extending through the board and connected to the printed conductor within the solder bridge.

Abstract: A replacement type gas tube protector for use with an older type telephone protector block utilizing a bayonet lug type engagement. The original carbon block protection is replaced by a gas tube element of smaller dimension, a conductive washer, and an insulative washer having a conductive sleeve. The conductive washer and gas tube element form a primary air gap means. The conductive washer and the insulative washer form a secondary air gap means.

Abstract: An arrangement for providing protection against overheating in a voltage limiting circuit in the event of overvoltages comprises a series arrangement of a voltage limiting element and a heat sensitive switching element. The voltage limiting element and heat sensitive switching element are connected by a high conductivity heat path so that when the temperature of the element increases this increase is passed to the switching element which reduces or switches off the current in the line between terminals two terminals.In operation a signal supply line is connected to terminal and the protected equipment is connected to terminal. The arrangement may be used to protect telephone exchange equipment from high voltages induced on telephone lines as a result, for example of lightning.

Abstract: A protector module (30) for protecting tip and ring conductors of a telephone loop includes a pair of protector assemblies (40-40') which are supported within a common housing (32). A voltage protection subassembly (42) of each protector assembly is connected electrially to a grounding subassembly (44) for causing current associated with excessive voltage surges to be conducted to ground. Each protector assembly also includes a current protection subassembly (41) which comprises a dielectric base and a line pin (61) and a central office pin (57) with the line and central office pins being connected together electrically to establish electrical contact between a conductor of the circuit and its protector assembly. A shunting element (62) is disposed concentrically about the line pin and is releasably secured to one end of the line pin in an initial position by a fusible bonding material.

Abstract: A replacement gas tube protector module for central office installation having older types of protector blocks in which the original carbon block assembly is resiliently clamped between a pair of spring fingers. The module is configured such that the resilient force exerted by the spring fingers serve to short a gas tube replacing the original carbon block in the event of failure of the gas tube component.

Abstract: An overvoltage surge protector and housing for telephone communication lines to protect equipment connected thereto includes an insulated housing having one terminal disposed therein which is adapted to be connected to earth ground and a second terminal disposed in a removable assembly which includes the means for connection to the communication line as an integral part thereof. The overvoltage surge protector device is adapted to be retained within the second terminal and, when removed for replacement by a service technician, requires that the communication line affixed to the terminal be removed from the terminal in order to remove the protector device, thus requiring the communication lines to be reconnected when the defective protective device is removed and/or replaced.

Abstract: A protector unit (30) for protecting tip-and-ring conductors of a telephone loop includes a pair of protector assemblies (40-40') which are supported within a common housing 932). A voltage protection subassembly (42) is connected electrically to a ground subassembly (44) for causing current associated with excessive voltage surges to be conducted to ground. Each protector assembly includes a heat coil subassembly (50) mounted on a dielectric half-base (51), together with a central office pin (57). The heat coil subassembly includes a line pin (61), an eyelet (62), disposed concentrically about the line pin and releasably secured to one end of the line pin in an initial position by a fusible bonding material, and a resistance wire (69), wound about the hub of the eyelet. One end of the wire is welded to the eyelet, and the other end is welded to the central office pin to establish a direct current path between the line pin and the central office pin.

Abstract: A line protector for central office use comprises an elongated housing open at one side for receiving components and a cover for the opening. First and second surge arresters are coaxially positioned within the housing. First and second line terminals are respectively connected to the arresters as is a common ground terminal. The three terminals project from one end of the housing in the provision of coplanar flat pins for plug-in connection with a circuit board edge connector. Means including a test contact in the housing permits use of a test probe to test the lines while the protector is plugged into the connector. A shiftable insulator in the housing is used optionally to interrupt the inside lines at the line terminal pins.

Abstract: A gas tube overvoltage protector has two opposed electrodes sealed in a tubular dielectric housing, the outer ends of the electrodes extending from the housing. The inner ends of the electrodes define a primary gap at sub-atmospheric pressure. The lower electrode has an extension of reduced diameter on its outer end. An auxiliary gap is formed by pushing on a metal cap over the lower end of the dielectric housing, with a thin flexible dielectric member between the cap and the outer end of the bottom electrode, the extension extending through the dielectric member and cap. One or more apertures in the thin dielectric member define the auxiliary gap, between metal cap and bottom electrode. A further feature is that the cage, within which the protector is positioned, has one or more legs preformed such that their lower ends are pushed into positive contact with the metal cap when assembled into a closed ended hollow cap for assembly into a protector block.

Abstract: A gas tube protector device for individual telephone subscriber circuits including a secondary air gap means which becomes operative in the event of gas tube failure with accompanying voltage surge.

Abstract: An improved gas type telephone protector module in which the firing of a heat-sensitive means causes a slidably mounted ground plate to bypass in both circuits to the flow of excess current and/or voltage surges to ground. Means are incorporated to provide a secondary air gap which becomes operative upon the failure of either chamber of the gas tube.

Abstract: A clip-on device to protect telephones and communication apparatus, wherein clips for releasably holding a 3-terminal gas protector are external extensions of electrically insulated spaced terminals within the housing. A heat coil in series with each communication line and a carbon block air gap protector across each half of the gas protector for redundancy, are within the housing. The heat coil protects against a sustained overcurrent condition on the line while the gas and air gap protectors ground over-voltages of short duration. Utilizing heat conduction means, heat generated from sustained over-voltage melts a fusible disc allowing spring biased parts within the housing to move and short line terminals to ground.

Abstract: An excess voltage arrester (1 to 21) provided with an overheating protection device comprising a resilient electrically conductive first member (23) in a flexed condition and a second member (25) of heat softenable electrically insulating material associated with the first member such that on over-heating of the arrester the second member softens allowing the first member to move in an attempt to return to its natural shape, and thereby establish an electrically conductive path through itself between the arrester electrodes.

Abstract: A surge arrester with a parallel-connected improved spark gap structure has a flanged ring connected to one of the two electrodes of the surge arrester which forms the first electrode of the spark gap structure, an axially aligned insulator disc having recesses therein seated on the flanged ring, and an annular metal contact seated on the opposite side of the insulator ring forming the second electrode of the spark gap structure through the recesses in the insulating ring has the improvements of the metal contact forming the second electrode of the spark gap being an annular cup having a base seated against the insulator ring and a conical wall connected via contact springs with the other electrode of the surge arrester, and the base of the annular cup has projections in registry with the insulator ring recesses extending a distance therein such that the spark gap is formed between the flanged ring and the highest elevation of the projections.

Abstract: A shorting cage is provided in a telephone terminal housing having a protector well so that when the protector device is removed from its cooperating well the shorting mechanism in the form of a cage will cause the line to remain shorted until a replacement protector is reinserted into the terminal well.

Abstract: A heat sensitive telephone protector module of a type having visual indicator means to indicate the actuation of heat sensitive means upon the occurrence of excessive current flow. The module includes dual heat sensitive units for protecting the tip and ring circuits of an individual subscriber pair, and a single indicator unit which is outwardly projected from the module housing by action of either heat sensitive element.

Abstract: A lightweight frame having a base of non-conducting material and end frame members consisting of aluminum mounts a pair of clip-type fuse supports. Each fuse support is attached to connectors which extend through the housing for connection to the lead in and ground lines of a radio, television, or like antenna. A plastic cover snaps in place over the base and ends to allow the user to view the condition of the fuses.

Abstract: An electrical surge arrester module having a back-up external spark gap in its base assembly comprising an insulator plate perforated at points intermediate a terminal contact surface in said base assembly and a conductive plate at ground potential when said surge arrester module is in use.

Abstract: A clip-on device for use with an over-voltage protector to protect telephones and other sensitive apparatus. The device comprises a housing in which is disposed in electrically insulated spaced array, electrical contact means and heat conduction means. Each of these means have portion external to the housing which detachably grasps the over-voltage protector. Movable elements disposed within the housing include electrically insulating fusible spacers. The housing clips onto the over-voltage protector and engages the respective electrodes thereof. A sustained overload condition causes the fusible spacers to fuse whereupon the movable elements operate to short the electrical contact means to ground.

Abstract: A line protector has a housing with coaxial surge voltage arresters, line terminals and a ground terminal. One line terminal is substantially at one end of the cavity of the housing while the other line terminal extends substantially the full length of the cavity of the housing. The ground terminal extends from between the arresters to said one end of the housing cavity. Each terminal projects from the housing at said one end. The three terminals are insultated from the arresters by barrier walls in the housing. A cover closes a side opening in the housing through which the components of the protector are inserted.

Abstract: A protective module of the type used in building entrance terminals having substantially greater heat sensitivity than prior art types, thereby offering protection against sneak currents which are not sufficiently large to activate conventional solder pellet heat sensors. Use is made of a bobbin type heat sensor, the thermal inertia value of which may be varied to alter sensitivity.

Abstract: A surge voltage arrester assembly comprises a primary gas tube surge arrester and an air gap secondary arrester that provides surge protection should the gas tube become vented to atmosphere. The secondary arrester has the air gap defined by a rim of one of the gas tube electrodes and an opposed roughened surface of a metallic cup into which the gas tube is positioned. The roughened cup surface has a coating of graphite applied thereto. The electrode rim may or may not be roughened and/or coated. In a three element version of the invention wherein the gas tube has two line electrodes and a ground electrode, metallic cups are provided at opposite ends of the gas tube to cooperate with the ground electrode for forming secondary air gaps for each line electrode. The cup surfaces at the secondary air gaps are roughened and graphite coated. An O-ring seals each secondary air gap against the entrance of contaminants.

Abstract: An improved telephone protector module for individual subscriber circuits incorporating, in addition to heat sensitive means for grounding outside plant tip and ring currents, switch means for simultaneously opening the tip and ring circuits leading to central office or PBX equipment when excessive current is detected. The switch means is normally in closed position when the heat sensitive means is in unfired condition.

Abstract: A clip-on device to protect telephones and communication apparatus, wherein clips for releasably holding a 3-terminal gas protector are external extensions of electrically insulated spaced terminals within the housing. A heat coil in series with each communication line and a carbon block air gap protector across each half of the gas protector for redundancy, are within the housing. The heat coil protects against a sustained overcurrent condition on the line while the gas and air gap protectors ground over-voltages of short duration. Utilizing heat conduction means, heat generated from sustained over-voltage melts a fusible disc allowing spring biased parts within the housing to move and short line terminals to ground.

Abstract: A line protector has a gas tube surge arrester as a primary protector and an air gap as a secondary or back-up protector should the gas tube fail due to leakage. The secondary air gap is established by perforated plastic sheets which are interposed between a line terminal and a ground contact both of which are supported on an insulating base.

Abstract: A lightning arrester device for power transmission line comprises a lightning arrester comprising a sintered product made of a main component such as zinc oxide; a serial connection of a reactor and a fusible wire connected to the lightning arrester in series and a gap connected in parallel with the serial connection. The lightning arrester is disconnected from a power transmission line when the lightning arrester is broken.

Abstract: An electrical protector device (10) for grounding excessive voltage and excessive current to safeguard telecommunications circuits includes a heat coil assembly (100) for sensing and directing excessive current to ground, and a spark gap arrester (200), axially aligned with the heat coil assembly (100), for sensing and controlling excessive voltage. Whenever an overcurrent condition is encountered, heat coil mechanism (110) is displaced to provide metallic contact of the incoming line to a ground structure (300). In addition, the device is adapted to provide protected testing of both incoming pairs and office equipment. Two test points (123) formed as part of the heat coil assembly (100) are in contact with the individual wires of the incoming line. These two test points are accessible through apertures (402) in the protector housing (400).

Abstract: Laminar air gap devices include two overlapping conductive layers separated by a non-metallic insulating layer. The insulating layer is perforated to provide at least one air gap between the conductive layers. The devices are positioned between a line electrode and ground electrode of a gas filled surge arrester and resiliently retained thereon by conductive clips. Non-metallic fusible elements, preferably plastic, are interposed between the clip legs and the associated electrode. The fusible element may also be the insulating layer between the conductive layers.

Abstract: A protection module for connecting blocks is intended notably for at least one line wire of a telephone system and comprises a case having a ground terminal, an input terminal and an output terminal for each line wire, and a first lightning arrester having a first terminal connected to the ground terminal and a second terminal clamped resiliently between two extensions of the line terminals, respectively. Another lightening arrester has a first terminal connected to the ground terminal and a second terminal clamped resiliently between two extensions of the other pair of line wire terminals. An orifice registering with a third pair of terminals parallel to the other pair of line wire terminals is adapted to guide a detachable element which comprises an insulating portion adapted to be fitted between the terminals of the third pair of the lightning arresters and each extension of the pair of output terminals.

Abstract: A metal oxide varistor (MOV) is directly electrically connected between a line conductor and ground to dissipate the energy associated with voltage surges appearing on the line conductor. A thermostatic switch, in the form of a resilient arm held in electrical connection with one of the MOV electrodes by low melting point solder, opens in response to a failing MOV to insert a spark gap electrically in series with the MOV. Overvoltage protection is thus maintained, albeit limited to higher level voltage surges.

Abstract: Gas filled surge arrester is equipped with a thermally responsive short circuit switch for overload protection and air gap shorting for back up overload protection. The switch and air gap device is disclosed in three orientations; namely, separate and external to the gas tube; unitized with the air gap interior to the switch; and unitized with the air gap exterior to the switch. The unitized arrangements have application in circuitry with gas tubes where back up air gap protection of the thermal switch is desired.

Abstract: A protector for a communications line comprises a three electrode gas tube surge voltage arrester as a primary protective device and metal oxide varistors as additional protective devices. In series with each side of the line, is an inductor that serves to isolate the gas tube from the varistors at relatively fast rise times of transient overvoltages. The gas tube, the varistors and the inductors are all mounted in a single housing that is divided into adjacent sections by an insulating member. The gas tube is in one section and the inductors and varistors are in the other section, the inductors being side-by-side and each coaxial with a pin that is adapted to be connected to the line.

Abstract: A line protector has an arrester through which overvoltages on the line of short duration are grounded. The arrester may be of the type having an arc gap sealed within a gas tube. For an overvoltage of longer duration, a pellet is melted causing a spring to close a circuit bypassing the gas tube and provide a direct metallic path from the line to ground. A secondary arc gap between opposed conductors separated by an insulating sleeve has an arc-over voltage that is greater than the normal arc-over voltage of the first-mentioned arc gap and provides a path to ground for short duration overvoltage conditions in the event of failure of the arrester. Excessive current across the secondary arc gap may melt the insulator sleeve and engage the opposed conductors for grounding purposes.