US707050A - Electrical protector set. - Google Patents

Electrical protector set. Download PDF

Info

Publication number
US707050A
US707050A US108329A US1902108329A US707050A US 707050 A US707050 A US 707050A US 108329 A US108329 A US 108329A US 1902108329 A US1902108329 A US 1902108329A US 707050 A US707050 A US 707050A
Authority
US
United States
Prior art keywords
base
post
springs
posts
cover
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US108329A
Inventor
Frank B Cook
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US60097096A external-priority patent/US704439A/en
Application filed by Individual filed Critical Individual
Priority to US108329A priority Critical patent/US707050A/en
Application granted granted Critical
Publication of US707050A publication Critical patent/US707050A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01TSPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T4/00Overvoltage arresters using spark gaps
    • H01T4/08Overvoltage arresters using spark gaps structurally associated with protected apparatus

Definitions

  • FRANK B COOK, OF CHICAGO, ILLINOIS.
  • thermal protector for electrical circuits.
  • the invention hereinafter described consists of a compact self-contained device involving a plurality of these thermal protectors.
  • the said device is adapted more particularly for use in connection with subscribers telephone sets.
  • the thermal protectors are adapted toafford protection against the intrusion of currents only slightly in excess of normal, sometimes called sneak-currents.
  • the device which, as stated, is .of a compact and selfcontained character and which preferably involves a porcelain base and a glass cover, is capable of protecting the subscribers telephone set against the intrusion of'currents of different character.
  • a special object is to provide a construction in which the protectors are so mounted and inclosed as to be easily connected with the circuit-wires.
  • Another object is to provide a constructionand arrangement for securing an efficient cooperation between different kinds of protectors.
  • Figure 1 is a side elevation of a circuit-protecting device embodying the principles of my invention, the glass dome or cover being shown in section.
  • Fig. 2 is a similar view showing another side of the device.
  • Fig. 3 is a plan of the device illustrated by Figs. 1 and 2.
  • Fig. 4 is a bottom view of the said device.
  • Fig. 5 is a detail sectional View illustrating a portion of the supporting structure for the protecting devices,
  • Fig. 6 is a perspective of one of the metal plates involved in the structure for supporting the lightning-arresters.
  • Fig. 1 is a side elevation of a circuit-protecting device embodying the principles of my invention, the glass dome or cover being shown in section.
  • Fig. 2 is a similar view showing another side of the device.
  • Fig. 3 is a plan of the device illustrated by Figs. 1 and 2.
  • Fig. 4 is a bottom view of the said device.
  • Fig. 5 is a detail sectional View illustrating
  • my invention comprises a suitable base A, which may be of porcelain or any other suitable material and which is adapted to serve as a support for the various binding-posts, springs, posts, carbon blocks,
  • the said base is preferably provided with an annular groove or channel a, adapted to receive the circular lower edge or perimeter of the cover B.
  • This cover is preferably of glass and, as will be observed, can be in the form of a dome.
  • the top of the said cover is preferably provided with an opening 0, adapted to receive the upwardly-projecting post 0.
  • the said post rises from the center of the base and its upper end portion is threaded to receive a clam ping-n ut c.
  • This nut itwill be seen, bears upon the top of the cover B and keeps the latter properly seated in the groove or channel a. It will also be observed that this postis formed witha shonl der 0, upon which rests the flat strip or block of insulation D.
  • a metal plateE preferably rests upon this strip or block of insulation, the said plate being provided with ahorizontal portion e, having an opening 6, adapted to receive the reduced threaded portion of the post 0.
  • This plate E is also preferably formed with a lower horizontal portion 6 having an opening 6
  • the bolt of the hinding-post F can be arranged to pass through this opening 9 and the said post can. in this way be employed for clamping the lower portion of the plate in place upon the base A.
  • this plate As a means for partially supporting the lightningarresters its lower edge can be formed with shoulders or ledges efladapted to'provide seats or resting-places for the lower ends of the carbon blocks G.
  • this plate With respect to the use of this plate as one member of a spring-switch for grounding an abnormally large current its upper edge can be provided with contactpoints e adapted to make contact with the flexible posts or springs H.
  • These posts or springs are, it will be observed, preferably provided with base portions it, having the openings h and 71 and also with the upwardly-projecting portions h These portions 7L3 cooperate with the plate B in holding the lightning-arresters. This will be understood more clearly by referring to Figs.
  • each post or spring H is preferably provided with a notch k and also with a small tongue or portion 72 Arranged opposite these posts H are a couple of similar posts K.
  • the said posts K can be provided with base portions 70, having openings adapted to receive the bolts of the binding-posts L.
  • the said binding-posts L which are in use preferably connected with the instruments of the subscribers telephone set, can be employed, like the other binding-posts previously described, for securing the post K firmly upon the base A.
  • the posts K preferably have their upper ends provided with notches 7c and also with tongues or small portions 10 It will also be seen that the posts K are arranged to rise through openings in the strip or block of insulation D. In this Way the posts K are practically held against movement, while the flexible posts or springs H are capable of more or less movement toward and away from the posts K.
  • the said of these heat-coils can be similar to that described in my aforesaid application. For this reason and in view of the fact that these heatcoils have attained a definite status in the art I have not shown or described anyparticular form or construction.
  • the device is adapted to serve as a protector in a complete metallic circuit.
  • the heat-coils I With one line-wire connected to one of the binding-posts J and with the other linewire connected with the other binding-post J the heat-coils I will constitute part of the circuit and will serve as medium of electrical connection between the instruments and the line conductors. I In this way all currents traversing the circuit pass through the heatcoils, it being observed that each heat-coil is connected up in series with the two posts upon which it is supported.
  • the bindingpost Fcan as stated, be connected with the grounded conductor. Withthisarrangement a current only slightly in excess of normal will cause either one or both of the heat-coils I to operate and to produce a break or gap in the circuit. Either heat-coil in releasing,
  • one of the springs H will establish connec tion with the ground, inasmuch as either of said springs when released will make contact with the plate E.
  • This plate being grounded, the abnormally large current will then be conducted to earth.
  • the trespassing current be of a difierent character, however as,'for example, such as would result from a lightning-strokeorsevere electrical stormthen the carbon blocks involved in the two lightning-arresters shown will serve as the medium of electrical connection between the line and the earth. In other words, the presence of the high-potential current on the line.
  • the post 0 serves not only as a means of clamping the dome-shaped cover 13 in. place, but also as a partial support for the protecting devices.
  • the springs H are normally held under tension by the heatcoils, but when released make contact with the plate E.
  • the post 0 may also serve as a means for resisting the pressure of the springs H upon the plate E.
  • the wires to be connected with the binding-posts can be inserted through the openings X in the base. After aIheat-coil has been operated by an abnormally large current the glass cover can be readily removed, and a new heat-coil can then be substituted for the old one.
  • the portions h are springy in character and hold the carbon bl0OlS firmly in contact with the plate E.
  • the post 0 also serves to resist the spring tension of the said portion 7L3.
  • the said post 0 not only serves as a means of'clamping the cover in place, but also as a means of centering the various plates, springs, the, and of holding the same against any displacement which might be due to the spring tension or to accidental bending of the different parts.
  • a self-contained protecting device for complete metalliccircuits com prising a base composed of insulation, a post rising from said base, a dome-shaped glass cover clamped upon said base by a nut screwed 'upon the said post, and a plurality of protecting devices mounted upon said base and partially supported by said post.
  • Aself-contained protector device forsubscribers stations, consisting of a plurality of heat-coil protectors, cond uctor-holders thereforand spring-contacts adapted to disrupt the circuit or circuits, together with high-tension protectors and holding-plate of insulating material secured by a central standard and serving to hold one side of contact-springs without movement in either direction, and a holding-plate for the high-tension protectors connected with the said central standard, the contact-points of which plate are held in the same position relative to the movable springcontacts by the connection aforesaid.
  • earth branch connected with said holders, carbon-holders having carbons therein also mounted on said base, line branches connectedwith said last-named holders, and linesprings and heat-coils in series in the lines, the conducting earth branch being normally out of contact with said springs but adapted to contact therewith in the operation of the heat-coils, substantially asdescribed.
  • a device for protecting circuits against excessive current consisting of a base, a post rising from said base, a cover resting upon said base, a n utapplied to the outer end of said post and holding said cover upon said base, springs mounted upon said base, a stop arranged to limit the movement of said springs, said stop having an opening through which the said post extends, a nut clamping a portion of said stop upon a shoulderon said post, suitable connections for grounding said stop, one or more electric circuitsincluding one or more of said springs, suitable connections for normally holding said springs away from said stop, one or more heat-concentrating members arranged to cause said last-mentioned connections to weaken or break upon the passage of excessive current through said circuit or circuits, said spring or springs, when released, operating to break said circuit or circuits and to establish connection with the ground through said stop.
  • a circuit-protector comprising a suitable base, a cover, a post rising from the base, a nut applied to the outer end ofsaid post for clamping the cover upon the base, a stop mounted upon the base, a nut for clamping the combination of a suitable base, a metal plate mounted thereonand adapted to be connected with a grounded conductor, a pair of carbon blocks suitably held against said plate, a binding-post adapted to be connected with a line conductor, the carbon blocks being normally separated but adapted to come together and establish connection between the line and the grounded conductor through the medium of said plate, a quantitative protector mounted to form part of the line-circuit, a member which when released by said quantitative protector establishes connection between the line conductor and the said plate, a post rising from said base, and a domeshaped glass cover held in place upon said base by a nut screwed onto the threaded upper end portion of said base.
  • a protector set for electrical circuits the combination of a quantitative protector, an intensity-protector, means whereby the quantitative protector when operated produces a break in the circuit, and means whereby either protector when operated establishes connection between the line and a grounded member.

Landscapes

  • Emergency Protection Circuit Devices (AREA)

Description

No. 707,050. Patented Aug. I2, I902.
F. B. 000K.
ELECTRICAL PROTECTOR SET.
(Application filed May 21, 1902.)
(No Model.)
\i iill Aiilliliiiiiiliiliiiiiiiiiii iii UNITED STATES PATENT OFFICE.
FRANK B. COOK, OF CHICAGO, ILLINOIS.
ELECTRICAL PROTECTO R SET.
SPECIFICATION forming part of Letters Patent No. 707,050, dated August 12, 1902.
Original application filed July 29, 1896, Serial No. 600,970. Divided and this application filed May 21, 1902. Serial Nil-108,329. (No model.)
T to whom it may concern:
Beitknownthatl, FRANK 13.00011, acitizen of the United States of America, and a resident of Chicago, Cook county, Illinois, have invented a certain new and useful ImprovementinElectrical Protector Sets, of which the following is a specification.
This'is a division of my application, Serial No. 600,970, filed July 20, 1896. In said application I have described and claimed an improved form of thermal protector for electrical circuits. The invention hereinafter described consists of a compact self-contained device involving a plurality of these thermal protectors. The said device is adapted more particularly for use in connection with subscribers telephone sets. It also, as will hereinafter more fully appear, involves a simple and efficient construction and arrangement whereby a plurality of the aforesaid thermal protectors may be employed in conjunction with a plurality of lightning-arresters. The thermal protectors are adapted toafford protection against the intrusion of currents only slightly in excess of normal, sometimes called sneak-currents. In this way the device, which, as stated, is .of a compact and selfcontained character and which preferably involves a porcelain base and a glass cover, is capable of protecting the subscribers telephone set against the intrusion of'currents of different character.
Generally stated, it is the object of my invention to provide a simple and comparatively inexpensive construction whereby a plurality of electrical protectors may be combined and efficiently employed in a compact and easily-accessible structure.
A special objectis to provide a construction in which the protectors are so mounted and inclosed as to be easily connected with the circuit-wires.
Another object is to provide a constructionand arrangement for securing an efficient cooperation between different kinds of protectors.
It is also an object to provide certain details and features of improvement tending to increase the general efficiency and serviceability of a device of this character.
To the foregoing'and other useful ends my invention consists in matters hereinafter set forth and claimed. y
In the accompanying drawings, Figure 1 is a side elevation of a circuit-protecting device embodying the principles of my invention, the glass dome or cover being shown in section. Fig. 2 is a similar view showing another side of the device. Fig. 3 is a plan of the device illustrated by Figs. 1 and 2. Fig. 4 is a bottom view of the said device. Fig. 5 is a detail sectional View illustrating a portion of the supporting structure for the protecting devices, Fig. 6 is a perspective of one of the metal plates involved in the structure for supporting the lightning-arresters. Fig. 7 shows one of the metal plates which serves to partially support one of the lightning-arresters and also one ofthe heat-coils involved in the thermal protector- As thus illustrated, my invention comprises a suitable base A, which may be of porcelain or any other suitable material and which is adapted to serve as a support for the various binding-posts, springs, posts, carbon blocks,
'heat-coils,'&c., involved in the structure.
The said base is preferably provided with an annular groove or channel a, adapted to receive the circular lower edge or perimeter of the cover B. This cover is preferably of glass and, as will be observed, can be in the form of a dome. The top of the said cover is preferably provided with an opening 0, adapted to receive the upwardly-projecting post 0. As illustrated, the said post rises from the center of the base and its upper end portion is threaded to receive a clam ping-n ut c. This nut, itwill be seen, bears upon the top of the cover B and keeps the latter properly seated in the groove or channel a. It will also be observed that this postis formed witha shonl der 0, upon which rests the flat strip or block of insulation D. A metal plateE preferably rests upon this strip or block of insulation, the said plate being provided with ahorizontal portion e, having an opening 6, adapted to receive the reduced threaded portion of the post 0. In this way the other nut 0 can be arranged to clamp both the plate E and the block of insulation D firmly upon the shoulder c. This plate E is also preferably formed with a lower horizontal portion 6 having an opening 6 The bolt of the hinding-post F can be arranged to pass through this opening 9 and the said post can. in this way be employed for clamping the lower portion of the plate in place upon the base A. With respect to the use of this plate as a means for partially supporting the lightningarresters its lower edge can be formed with shoulders or ledges efladapted to'provide seats or resting-places for the lower ends of the carbon blocks G. With respect to the use of this plate as one member of a spring-switch for grounding an abnormally large current its upper edge can be provided with contactpoints e adapted to make contact with the flexible posts or springs H. These posts or springs are, it will be observed, preferably provided with base portions it, having the openings h and 71 and also with the upwardly-projecting portions h These portions 7L3 cooperate with the plate B in holding the lightning-arresters. This will be understood more clearly by referring to Figs. 1 and 5, where it will be seen that the carbon blocks G and G are held firmly between the said portions it and the back or outer surface of the said plate E. Strips ofinsulation-as, for example, the layers of silk g-can be arranged between the carbon blocks, thus constituting the lightning-arresters. In this way the bent plates or spring-like members H are adapted, as will be seen, to not only partially support the heat-coils I, but to also partially support the carbon blocks of the lightning-arresters. In addition these spring posts or members H are, as will hereinafter more .fully appear,
adapted to serve as a spring-switch for 03-,
tablishing connection between the line and the ground. The openings h are adapted to receive the bolts of the bindingposts J. These binding-posts are in use preferably connected with the line-wires. The openings 71 can receive small screws adapted to assist in securing these spring-like members to the base A. The upper end of each post or spring H is preferably provided with a notch k and also with a small tongue or portion 72 Arranged opposite these posts H are a couple of similar posts K. The said posts K can be provided with base portions 70, having openings adapted to receive the bolts of the binding-posts L. In this way the said binding-posts L, which are in use preferably connected with the instruments of the subscribers telephone set, can be employed, like the other binding-posts previously described, for securing the post K firmly upon the base A. Like the springs H, the posts K preferably have their upper ends provided with notches 7c and also with tongues or small portions 10 It will also be seen that the posts K are arranged to rise through openings in the strip or block of insulation D. In this Way the posts K are practically held against movement, while the flexible posts or springs H are capable of more or less movement toward and away from the posts K. The said of these heat-coils can be similar to that described in my aforesaid application. For this reason and in view of the fact that these heatcoils have attained a definite status in the art I have not shown or described anyparticular form or construction.
As thus constructed the device is adapted to serve as a protector in a complete metallic circuit. With one line-wire connected to one of the binding-posts J and with the other linewire connected with the other binding-post J the heat-coils I will constitute part of the circuit and will serve as medium of electrical connection between the instruments and the line conductors. I In this way all currents traversing the circuit pass through the heatcoils, it being observed that each heat-coil is connected up in series with the two posts upon which it is supported. The bindingpost Fcan, as stated, be connected with the grounded conductor. Withthisarrangement a current only slightly in excess of normal will cause either one or both of the heat-coils I to operate and to produce a break or gap in the circuit. Either heat-coil in releasing,
one of the springs H will establish connec tion with the ground, inasmuch as either of said springs when released will make contact with the plate E. This plate being grounded, the abnormally large current will then be conducted to earth. Should the trespassing current be of a difierent character, however as,'for example, such as would result from a lightning-strokeorsevere electrical stormthen the carbon blocks involved in the two lightning-arresters shown will serve as the medium of electrical connection between the line and the earth. In other words, the presence of the high-potential current on the line.
will cause the insulation or silk dielectric G in either arrester to burn away, and thereby allow the two carbon'plates to come together. If the current is only transient,the momentary arcing from one carbon plate to the other will leave the silk practically intact; but, as explained, if the current is sufliciently strong it will burn out the silk and allow the two carbon blocks to come together. Thus it will be seen that the heat-coils and-lightning-arresters are arranged in a compact and readily-accessible manner. The post 0 serves not only as a means of clamping the dome-shaped cover 13 in. place, but also as a partial support for the protecting devices. The springs H are normally held under tension by the heatcoils, but when released make contact with the plate E. In this Way the post 0 may also serve as a means for resisting the pressure of the springs H upon the plate E. The wires to be connected with the binding-posts can be inserted through the openings X in the base. After aIheat-coil has been operated by an abnormally large current the glass cover can be readily removed, and a new heat-coil can then be substituted for the old one.
The portions h are springy in character and hold the carbon bl0OlS firmly in contact with the plate E. Thus the post 0, it will be seen, also serves to resist the spring tension of the said portion 7L3. In fact, the said post 0 not only serves as a means of'clamping the cover in place, but also as a means of centering the various plates, springs, the, and of holding the same against any displacement which might be due to the spring tension or to accidental bending of the different parts.
'I claim as my invention 1. A self-contained protecting device for complete metalliccircuits, com prising a base composed of insulation,a post rising from said base, a dome-shaped glass cover clamped upon said base by a nut screwed 'upon the said post, and a plurality of protecting devices mounted upon said base and partially supported by said post.
2. Aself-contained protector deviceforsubscribers stations, consisting of a plurality of heat-coil protectors, cond uctor-holders thereforand spring-contacts adapted to disrupt the circuit or circuits, together with high-tension protectors and holding-plate of insulating material secured by a central standard and serving to hold one side of contact-springs without movement in either direction, and a holding-plate for the high-tension protectors connected with the said central standard, the contact-points of which plate are held in the same position relative to the movable springcontacts by the connection aforesaid.
3. The combination with a support, of a plurality of lines, carbon-holders mounted on said support, carbons in said holders, an
earth branch connected with said holders, carbon-holders having carbons therein also mounted on said base, line branches connectedwith said last-named holders, and linesprings and heat-coils in series in the lines, the conducting earth branch being normally out of contact with said springs but adapted to contact therewith in the operation of the heat-coils, substantially asdescribed.
4. The combination with a support, of a plurality of sets of opposing carbon-holders with normally separated carbons therein, sets of opposing line-springs also mounted on said support, heat-coils between the ends of said opposing springs, and a strip adjacent the free ends of one of said opposing sets of linesprings normally out ofcontact therewith but adapted to be engaged by any of said adjacent springs when the heat-coil in circuit therewith is operated by an abnormal current.
5. The combination with a base, of opposing carbon-holding spring-strips having normally separated blocks of carbon between their free ends, opposing line spring-strips in line with the other strips, one member of each pair of line-strips being electrically connected with one of the holding-strips, heatcoils between the free ends of the line-strips, a stationary bar or strip mounted adjacent the free ends oi one set of the line-strips with which they contact when the heat-coils are operated to release said free ends.
(5. A device for protecting circuits against excessive current, consisting of a base, a post rising from said base, a cover resting upon said base, a n utapplied to the outer end of said post and holding said cover upon said base, springs mounted upon said base, a stop arranged to limit the movement of said springs, said stop having an opening through which the said post extends, a nut clamping a portion of said stop upon a shoulderon said post, suitable connections for grounding said stop, one or more electric circuitsincluding one or more of said springs, suitable connections for normally holding said springs away from said stop, one or more heat-concentrating members arranged to cause said last-mentioned connections to weaken or break upon the passage of excessive current through said circuit or circuits, said spring or springs, when released, operating to break said circuit or circuits and to establish connection with the ground through said stop.
7. The combination of a base havingan annular groove, a post rising from said base, a glass cover seated in said groove, a nut applied to the outer end of said post for clamping said cover in place, automatic cut-out devices mounted upon said base and inclosed by said cover, and a member suitably connected with said post and arranged to cooperate with said cut-out devices in establishing connection with the ground.
8. The combination of a suitable base, a centrally-located post rising from said base, a cover and nut applied to the outer end of said post for clamping said cover upon the base, circuit connections mounted upon said base and including one or more springs held under tension, a stop connected with said post and adapted to limit the movement of said spring or springs, a binding-post for connecting said stop with a grounded conductor, heatcoil devices connected and arranged to release the connections holding said spring or springs under tension, the said spring or springs, when released as a result of the passage of excessive current through said heatcoils,operating to automatically establish connection with the ground through said stop.
9. The combination of a suitable base, a post rising from said base, a suitable cover, a nut applied to the outer end of said post for clamping said cover upon said base, suitable binding-posts mounted upon said base and inclosed by said cover, and automatic cut-out devices connected with said binding-posts and partially supported by said post.
10. A circuit-protector comprising a suitable base, a cover, a post rising from the base, a nut applied to the outer end ofsaid post for clamping the cover upon the base, a stop mounted upon the base, a nut for clamping the combination of a suitable base, a metal plate mounted thereonand adapted to be connected with a grounded conductor, a pair of carbon blocks suitably held against said plate, a binding-post adapted to be connected with a line conductor, the carbon blocks being normally separated but adapted to come together and establish connection between the line and the grounded conductor through the medium of said plate, a quantitative protector mounted to form part of the line-circuit, a member which when released by said quantitative protector establishes connection between the line conductor and the said plate, a post rising from said base, and a domeshaped glass cover held in place upon said base by a nut screwed onto the threaded upper end portion of said base.
12. In a protector set for electrical circuits, the combination of a quantitative protector, an intensity-protector, means whereby the quantitative protector when operated produces a break in the circuit, and means whereby either protector when operated establishes connection between the line and a grounded member.
Signed by me at Chicago, Cook county, Illinois, this 14th day of May, 1902.
FRANK B. COOK,
WVitnesses:
ARTHUR F. DURAND, HARRY P. BAUMGARTNER.
US108329A 1896-07-29 1902-05-21 Electrical protector set. Expired - Lifetime US707050A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US108329A US707050A (en) 1896-07-29 1902-05-21 Electrical protector set.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US60097096A US704439A (en) 1896-07-29 1896-07-29 Thermal protector for electric circuits.
US108329A US707050A (en) 1896-07-29 1902-05-21 Electrical protector set.

Publications (1)

Publication Number Publication Date
US707050A true US707050A (en) 1902-08-12

Family

ID=2775580

Family Applications (1)

Application Number Title Priority Date Filing Date
US108329A Expired - Lifetime US707050A (en) 1896-07-29 1902-05-21 Electrical protector set.

Country Status (1)

Country Link
US (1) US707050A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2619518A (en) * 1949-12-08 1952-11-25 Bell Telephone Labor Inc Cable terminal

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2619518A (en) * 1949-12-08 1952-11-25 Bell Telephone Labor Inc Cable terminal

Similar Documents

Publication Publication Date Title
US4107567A (en) Surge protector
US2465540A (en) Electrical connector
US707050A (en) Electrical protector set.
US1448559A (en) Electrical protective device
US690364A (en) Electric switch.
US732012A (en) Switchboard.
US607251A (en) Harry a
US2256232A (en) Electric cutout with lightning protection
US783995A (en) Test-plug for protective apparatus.
US4380036A (en) Clip-on protector
US786005A (en) Electric protector apparatus.
US4317153A (en) Clip-on protector
US2224614A (en) Contact assembly for cutouts
US287532A (en) aodbaed
US1199349A (en) High-tension-telegraph-circuit protector.
JP2017204428A (en) Circuit breaker for wiring
US759963A (en) Plural lamp-socket.
US413429A (en) Cable terminal head and protector
US1275918A (en) Switch.
US842628A (en) Substation-protector.
US473848A (en) mayer
US774158A (en) Protective device for electrical circuits.
US462463A (en) Henry price ball
US802497A (en) Ground-strip for protective apparatus.
US757388A (en) Lightning-arrester.