US1597320A - Circuit-making device - Google Patents

Circuit-making device Download PDF

Info

Publication number
US1597320A
US1597320A US579934A US57993422A US1597320A US 1597320 A US1597320 A US 1597320A US 579934 A US579934 A US 579934A US 57993422 A US57993422 A US 57993422A US 1597320 A US1597320 A US 1597320A
Authority
US
United States
Prior art keywords
link
disruptable
switch
circuit
current
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
US579934A
Inventor
Laurence M Klauber
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.)
San Diego Cons Gas & Electric
San Diego Consolidated Gas & Electric Co
Original Assignee
San Diego Cons Gas & Electric
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
Application filed by San Diego Cons Gas & Electric filed Critical San Diego Cons Gas & Electric
Priority to US579934A priority Critical patent/US1597320A/en
Application granted granted Critical
Publication of US1597320A publication Critical patent/US1597320A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H83/00Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
    • H01H83/10Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by excess voltage, e.g. for lightning protection

Definitions

  • This invention relates to circuit-making devices and the invention is especially applicable to such a device when used withto make the circuit.
  • fusible material has been used to maintain an open switch and operating in such a way that when the current through the fusible material reaches a certain amperage, the material will fuse or fail and thereby effect the closing of the switch.
  • My invention diiiers from such a device by reason of the fact that my restraining member which prevents the closing of the switch normally prevents the passage of any current through it and its functioning does not depend merely upon amperage of a continuously passing current, but upon the existence of a predetermined potential. According to my invention, I
  • a furt er object of the invention is to provide simple means operating to suppress the spark which may be formed when the restraining member falls under the action of the high potential.
  • the invention consists in the novel features, and in the neral combination of parts to be particu arly described herein after, all of which contribute to produce a simple and efficient circuit-making device.
  • a preferred embodiment of my invention will be particularly described in the following specification, while the broad scope of my invention will be pointed out in the ap ended claims.
  • FIG. 1 is a side elevation showing diagrammatically a circuit-making device em- Serial No. 579,934.
  • bodying my invention and showing the switch in its open position
  • F1gu re 2 is a similar View but illustrating the switch closed as it would be after the device had operated; this view also indicates two connecting wires which are not illustrated in Figure 1;
  • Figure 3 is a side elevation illustrating another embodiment of the disruptable member or link which constitutes a feature of my invention
  • Figure 4 is a side elevation illustrating another embodiment of the disruptable link
  • Figure 5 is a perspective illustrating another embodiment of the disruptable link
  • Figure 6 is a perspective illustrating another embodiment of the disruptable link
  • Figure 7 is a side elevation illustrating another embodiment of the disruptable link in which the middle portion of the link is envelopedby a protective casing.
  • Figure 8 is a diagrammatic View illustrating an application of'the invention to a switch in which the potential is not exerted between the pointswhich may be connected by the switch.
  • a disruptable restraining member which 00- operates directly or otherwise with a switch member to maintain the switch open and this disruptable member consists of a conductive part and a dielectric resistance which co-operate together to resist the force which tends to close'the switch.
  • This force might be simply gravity but is preferably a spring mountedin such a way that it tends to close the switch; the conductive part and the dielectric resistance operate under the normal potential existing across the switch to prevent passage of current and operate under a predetermined potential to permit passage of a current which disrupts the disruptable member and permits the switch to close.
  • FIG. 1 and 2 A practical embodiment of the circuitinaking deviceis illustrated in Figures 1 and 2 in which an open switch is represented, comprising a movable switch member 1 and a contact 2 mounted so as to be engaged by the switch member to close the switch and thereby connect the two conductors 3 and at which must be connected to close the circuit.
  • the contact 2 is connected to an arm 5 of conductive material which extends upwardly and has a horizontal upper extension (3 which may terminate in a hook 7 so as to enable the arm to operate as a support to suspend a disruptable link 8.
  • the conductive part of the disruptable link 8 consists of two wires 9 and 10 which are connected together by a small loop 11 of cotton thread or equivalent material, which enables a dielectric resistance to be formed at this point. As the cotton loop is a nonconductor. the dielectric resistance at this point is virtually the resistance of the air in the gap between the adjacent ends of the two wires 9 and 10. The length of this loop enables the length of this gap or resistance to be accurately determined and this enables the potential which the device will withstand, to be very nicely predetermined.
  • the disruptable link-0t course, will prevent passage of current under the normal potential, but as soon as the normal potential existing between the circuit-points 3 and 4 is exceeded. a spark will jump across the gap at the loop 11 thereby efiecting the disruption of the link and permitting the switch to close.
  • a remarkable fact in connection with the disruption oi this link is that the spark effects the disruption of the link by fusing the metal of one of the wires at the loop and in this way, disrupts the link without necessarily destroying the cotton loop.
  • reactance means may be provided associated with the switch in such a way that it will operate or tend to suppress a spark, or limit the current flow, which is developed at the dielectric gap when the link fails.
  • I may provide a wire coil 12 disposed around the middle portion of the arm 5 and if desired, the middle portion of this arm may be made discontinuous so that the arm consists of two metallic sections 5 and 5 (see Figure 2) which project into a coil 13 and are connected by wires 13 with the coil so that the current which develops the spark must flow through the coil.
  • the disruptable member may be constructed in a great variety of ways.
  • the disruptable link consists of two wires 14- and 15. the outer ends of which are bare and formed into loops to engage the hooks ot the support and switch member,
  • a dielectric gap may be formed by utilizing a small dielectric body l7 which may be formed of card-board or similar non-conductive material.
  • This body may be of rectangular form and provided with a longitudinally disposed slot 18 placed so that the wires 19 and 20 may be attached to the card-board at the ends of the slot (see Figure In this instance, the dielectric resistance is virtually the length of the air gap between the adjacent ends of the two wires 19 and 20.
  • Another embodiment of the link may be constructed in which the dielectric gap consists of insulation. Such a form is illustrated in Figure 6 and consists of two loops 2] and '22 of wire covered with insulation. Vith a link of this character, the maximum dielectric gap in the link exists of course. at the touching point of the two loops and is substantially equal to twice the thickness of the insulation.
  • FIG. '7 Another very simple form of the link is illustrated in Figure '7 and consists simply of a single piece of insulated wire, disposed in an elongated loop, the body ot which is covered with a protecting casing or tube 23 from the ends of which the wire extends so as to form two end loops 24; and 25 which may be applied to the hooks ot the support and switch member to hold the switch open.
  • the switch co-operating with the disruptable link may he of any desired construction. It is merely necessary that the restrained part should be capable of closing the switch when it is n t further restrained by the disruptable link. It is obvious that the restrained member need not necessarily be a part of the switch, but could operate indirectly by its movement when released. to effect the closing of a cir cuit.
  • a switch such as that illustrated could be constructed of course. to close by gravity, but as this would render the closing of the switch slow and unreliable. I prefer to provide special means for quickly closing the switch. In the present instance. the means which I have illustrated is a spring such as the spring 26 which is mounted at the pivot pin 27 ot the movable switch member 1.
  • the switch lever 28 may be swung down by a spring (not illustrated) so as to bridge the contacts 33 and 34 and thereby close another circuit.
  • What I claim is 1.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable restraining member for holding the switch member in its open position consisting of a conductive part and a dielectric resistance cooperating to resist the force tending to close the switch, operating under the normal potential to prevent passage of current, and operating under a predetermined potential to permit passage of a current which disrupts the disruptable member and permits the switch to close, said disruptable restraining member being so arranged as to constitute a path for the current which disrupts same.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable link connected with the switch member for holding the same in its open position, said disruptable link consisting of a conductive part and a dielectric resistance co-operating to resist the force tending to close the switch, operating under the normal potential to prevent passage of. current and operating under a predetermined potential to permit passage of a current which disrupts the disruptable link and permits the switch to close, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable link connected with the switch member exerting a tensile force to hold the same in its open position, said disruptable link including a conductive part and a dielectric resisting substance associated with the conductive part, operating under the normal potential to prevent passage of current, and operating under a predetermined potential to permit passage of a current which disrupts the disruptable link and permits the switch to close, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
  • a movable switch member for use with high potential circuits, the combination of a movable switch member, a contact to cooperate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm, said disruptable link consisting of a conductive part and a dielectric resistance exerting a tensile force to hold the movable switch member outof engagement with said contact, operating under the normal potential to prevent passage of current through the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to cooperate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm and holding the movable switch member out of engagement with the said contact, said disruptable link including a conductive part and a dielectric resistance (to-operating under the normal potential to prevent passage of current through the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, and i'eactance means associated with the arm and operating to suppress the spark occasioned by the disruption of the disruptable link.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to co-opcrate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm and attached to the switch member, said disruptable link in cluding a conductive part and a dielectric resistance maintained in tension to hold the switch open. co-operating under the normal potential to prevent passage of current through. the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, and reactance means associated with the arm and operating to suppress the spark occasioned by the disrupton of the disruptable link.
  • a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to, cooperate therewith, means associated with the movable switch member to move it into engagement with the said contact, a fixed support metallicallv connected with the contact, and a disruptable link attached at one end to the support and at the other end to the link and permit the switch member to engage the contact, said disruptable link being so arranged as to constitute a path for the current which disrupts same.

Landscapes

  • Arc-Extinguishing Devices That Are Switches (AREA)

Description

, 1,597,320 L. M. KLAUBER CIRCUIT MAKING DEVICE Filed August 5, 1922 Ii I p fairly accurate! Patented Aug. 24, 1926.
UNITED STATES. PATENT OFFICE.
' LAURENCE KLAUBEB, OF SAN DIEGO, CALIFORNIA ASSIGNOR F ONE-HALF TO SAN DIEGO CONSOLIDATED GAS & ELECTRIC COMPANY, OF SAN DIEGO, CALIFORNIA, A
CORPORATION 01 CALIFORNIA.
CIRCUIT-MAKING DEVICE.
Application fled August 5, 1922.
This invention relates to circuit-making devices and the invention is especially applicable to such a device when used withto make the circuit. I am aware that fusible material has been used to maintain an open switch and operating in such a way that when the current through the fusible material reaches a certain amperage, the material will fuse or fail and thereby effect the closing of the switch. My invention diiiers from such a device by reason of the fact that my restraining member which prevents the closing of the switch normally prevents the passage of any current through it and its functioning does not depend merely upon amperage of a continuously passing current, but upon the existence of a predetermined potential. According to my invention, I
provide a disruptable member to operate as a restraining member characterized by theproperty that it affords a dielectric resistance which can be nicely regulated so as to insure that the disruptable link will fail I at a predetermined po-- tential. A furt er object of the invention is to provide simple means operating to suppress the spark which may be formed when the restraining member falls under the action of the high potential.
Further objects of the invention will appear hereinafter.
The invention consists in the novel features, and in the neral combination of parts to be particu arly described herein after, all of which contribute to produce a simple and efficient circuit-making device. A preferred embodiment of my invention will be particularly described in the following specification, while the broad scope of my invention will be pointed out in the ap ended claims. I
n the drawing:- Figure 1 is a side elevation showing diagrammatically a circuit-making device em- Serial No. 579,934.
bodying my invention and showing the switch in its open position;
F1gu re 2 is a similar View but illustrating the switch closed as it would be after the device had operated; this view also indicates two connecting wires which are not illustrated in Figure 1;
Figure 3 is a side elevation illustrating another embodiment of the disruptable member or link which constitutes a feature of my invention;
Figure 4 is a side elevation illustrating another embodiment of the disruptable link;
Figure 5 is a perspective illustrating another embodiment of the disruptable link;
Figure 6 is a perspective illustrating another embodiment of the disruptable link;
Figure 7 is a side elevation illustrating another embodiment of the disruptable link in which the middle portion of the link is envelopedby a protective casing.
Figure 8 is a diagrammatic View illustrating an application of'the invention to a switch in which the potential is not exerted between the pointswhich may be connected by the switch. I
In practicing my invention, "I employ a disruptable restraining member which 00- operates directly or otherwise with a switch member to maintain the switch open and this disruptable member consists of a conductive part and a dielectric resistance which co-operate together to resist the force which tends to close'the switch. This force might be simply gravity but is preferably a spring mountedin such a way that it tends to close the switch; the conductive part and the dielectric resistance operate under the normal potential existing across the switch to prevent passage of current and operate under a predetermined potential to permit passage of a current which disrupts the disruptable member and permits the switch to close.
While it is not essential to suppress the spark which is occasioned when the disruptable member fails or burns out, I prefer to provide such means. i
A practical embodiment of the circuitinaking deviceis illustrated in Figures 1 and 2 in which an open switch is represented, comprising a movable switch member 1 and a contact 2 mounted so as to be engaged by the switch member to close the switch and thereby connect the two conductors 3 and at which must be connected to close the circuit.
The contact 2 is connected to an arm 5 of conductive material which extends upwardly and has a horizontal upper extension (3 which may terminate in a hook 7 so as to enable the arm to operate as a support to suspend a disruptable link 8. The conductive part of the disruptable link 8 consists of two wires 9 and 10 which are connected together by a small loop 11 of cotton thread or equivalent material, which enables a dielectric resistance to be formed at this point. As the cotton loop is a nonconductor. the dielectric resistance at this point is virtually the resistance of the air in the gap between the adjacent ends of the two wires 9 and 10. The length of this loop enables the length of this gap or resistance to be accurately determined and this enables the potential which the device will withstand, to be very nicely predetermined. In the operation of the device, the disruptable link-0t course, will prevent passage of current under the normal potential, but as soon as the normal potential existing between the circuit- points 3 and 4 is exceeded. a spark will jump across the gap at the loop 11 thereby efiecting the disruption of the link and permitting the switch to close. A remarkable fact in connection with the disruption oi this link is that the spark effects the disruption of the link by fusing the metal of one of the wires at the loop and in this way, disrupts the link without necessarily destroying the cotton loop.
If desired, reactance means may be provided associated with the switch in such a way that it will operate or tend to suppress a spark, or limit the current flow, which is developed at the dielectric gap when the link fails. For this purpose, I may provide a wire coil 12 disposed around the middle portion of the arm 5 and if desired, the middle portion of this arm may be made discontinuous so that the arm consists of two metallic sections 5 and 5 (see Figure 2) which project into a coil 13 and are connected by wires 13 with the coil so that the current which develops the spark must flow through the coil.
In Figure 3. I illustrate the disruptable link 8 separated from the other parts of the circuit-making device.
The disruptable member may be constructed in a great variety of ways. In Figure 4, the disruptable link consists of two wires 14- and 15. the outer ends of which are bare and formed into loops to engage the hooks ot the support and switch member,
the adjacent portions of the wires being pro vided with an insulating covering 16; these insulated ends of the wires are simply twisted together. In this instance, the dielectric gap is formed lry the insulation itself. This is a very simple form of the link and in operation. necessitates a more substantial tusion ot' the metal than is necessary in the form of link shown in Figure 3.
Instead of using a loop of cotton thread, a dielectric gap may be formed by utilizing a small dielectric body l7 which may be formed of card-board or similar non-conductive material. This body may be of rectangular form and provided with a longitudinally disposed slot 18 placed so that the wires 19 and 20 may be attached to the card-board at the ends of the slot (see Figure In this instance, the dielectric resistance is virtually the length of the air gap between the adjacent ends of the two wires 19 and 20. Another embodiment of the link may be constructed in which the dielectric gap consists of insulation. Such a form is illustrated in Figure 6 and consists of two loops 2] and '22 of wire covered with insulation. Vith a link of this character, the maximum dielectric gap in the link exists of course. at the touching point of the two loops and is substantially equal to twice the thickness of the insulation.
Another very simple form of the link is illustrated in Figure '7 and consists simply of a single piece of insulated wire, disposed in an elongated loop, the body ot which is covered with a protecting casing or tube 23 from the ends of which the wire extends so as to form two end loops 24; and 25 which may be applied to the hooks ot the support and switch member to hold the switch open.
Of course. the switch co-operating with the disruptable link may he of any desired construction. It is merely necessary that the restrained part should be capable of closing the switch when it is n t further restrained by the disruptable link. It is obvious that the restrained member need not necessarily be a part of the switch, but could operate indirectly by its movement when released. to effect the closing of a cir cuit. A switch such as that illustrated could be constructed of course. to close by gravity, but as this would render the closing of the switch slow and unreliable. I prefer to provide special means for quickly closing the switch. In the present instance. the means which I have illustrated is a spring such as the spring 26 which is mounted at the pivot pin 27 ot the movable switch member 1.
It is not necessary that the potential which destroys the disruptable link. be exerted across the points that are connected by the switch: and the d srupting oi? the link may be utilized to open a switch or close a switch, or both, for. exam le in Figure 8,1
30 and 31 of a circuit, by a disruptable link 32. When the link disrupts, the switch lever 28 may be swung down by a spring (not illustrated) so as to bridge the contacts 33 and 34 and thereby close another circuit.
It is understood that the embodiment of the invention described herein is only one of the many embodiments my invention may take, and I do not wish to be limited in the practice of my invention nor in my claims, to the particular embodiment set forth.
What I claim is 1. In a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable restraining member for holding the switch member in its open position consisting of a conductive part and a dielectric resistance cooperating to resist the force tending to close the switch, operating under the normal potential to prevent passage of current, and operating under a predetermined potential to permit passage of a current which disrupts the disruptable member and permits the switch to close, said disruptable restraining member being so arranged as to constitute a path for the current which disrupts same.
2. In a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable link connected with the switch member for holding the same in its open position, said disruptable link consisting of a conductive part and a dielectric resistance co-operating to resist the force tending to close the switch, operating under the normal potential to prevent passage of. current and operating under a predetermined potential to permit passage of a current which disrupts the disruptable link and permits the switch to close, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
3.. In a circuit-making device for use with high potential circuits, the combination of a movable switch member capable of closing a circuit, and a disruptable link connected with the switch member exerting a tensile force to hold the same in its open position, said disruptable link including a conductive part and a dielectric resisting substance associated with the conductive part, operating under the normal potential to prevent passage of current, and operating under a predetermined potential to permit passage of a current which disrupts the disruptable link and permits the switch to close, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
4. In a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to cooperate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm, said disruptable link consisting of a conductive part and a dielectric resistance exerting a tensile force to hold the movable switch member outof engagement with said contact, operating under the normal potential to prevent passage of current through the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
5. In a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to cooperate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm and holding the movable switch member out of engagement with the said contact, said disruptable link including a conductive part and a dielectric resistance (to-operating under the normal potential to prevent passage of current through the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, and i'eactance means associated with the arm and operating to suppress the spark occasioned by the disruption of the disruptable link.
6. In a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to co-opcrate therewith, a conducting arm connected with the contact, and a disruptable link supported by the arm and attached to the switch member, said disruptable link in cluding a conductive part and a dielectric resistance maintained in tension to hold the switch open. co-operating under the normal potential to prevent passage of current through. the link, and operating under a predetermined potential to permit passage of a current which disrupts the link and permits the switch member to engage the contact, and reactance means associated with the arm and operating to suppress the spark occasioned by the disrupton of the disruptable link.
7. In a circuit-making device for use with high potential circuits, the combination of a movable switch member, a contact to, cooperate therewith, means associated with the movable switch member to move it into engagement with the said contact, a fixed support metallicallv connected with the contact, and a disruptable link attached at one end to the support and at the other end to the link and permit the switch member to engage the contact, said disruptable link being so arranged as to constitute a path for the current which disrupts same.
In testimony whereof, I have hereunto set my hand.
LAURENCE M. KLAUBER.
US579934A 1922-08-05 1922-08-05 Circuit-making device Expired - Lifetime US1597320A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US579934A US1597320A (en) 1922-08-05 1922-08-05 Circuit-making device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US579934A US1597320A (en) 1922-08-05 1922-08-05 Circuit-making device

Publications (1)

Publication Number Publication Date
US1597320A true US1597320A (en) 1926-08-24

Family

ID=24318948

Family Applications (1)

Application Number Title Priority Date Filing Date
US579934A Expired - Lifetime US1597320A (en) 1922-08-05 1922-08-05 Circuit-making device

Country Status (1)

Country Link
US (1) US1597320A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2469215A (en) * 1944-09-09 1949-05-03 Gen Electric Protective device
WO2006059011A1 (en) * 2004-12-03 2006-06-08 Abb France Device for protecting an electrical installation, corresponding method and use

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2469215A (en) * 1944-09-09 1949-05-03 Gen Electric Protective device
WO2006059011A1 (en) * 2004-12-03 2006-06-08 Abb France Device for protecting an electrical installation, corresponding method and use
FR2879033A1 (en) * 2004-12-03 2006-06-09 Soule Prot Surtensions Sa DEVICE FOR PROTECTING AN ELECTRICAL INSTALLATION, METHOD AND USE THEREOF
US20100027182A1 (en) * 2004-12-03 2010-02-04 Lindeperg Herve Device for protecting an electrical installation, corresponding method and use

Similar Documents

Publication Publication Date Title
US1597320A (en) Circuit-making device
US2087744A (en) Method of and means for automatically opening and reclosing a circuit
US1373128A (en) Automatic electrical cut-out
US2630508A (en) Circuit interrupter
US2462212A (en) Protective switch
US2200608A (en) Fuse
US970169A (en) Electrical protective apparatus.
US2509892A (en) Fuse construction
US1232458A (en) Ignition-switch.
US2137270A (en) Protective device for electric circuits
US1147448A (en) Fuse device.
US2097775A (en) Circuit breaker
USRE14881E (en) Overload circuit-breaking apparatus
US533183A (en) Henry g
US2348034A (en) Reclosing circuit-interrupting device
US1635544A (en) Circuit breaker
US1152148A (en) Electric fuse.
US1896218A (en) Signal indicating system
US1849117A (en) Electric protective system
US704361A (en) Electric cut-out.
US1864783A (en) Thermostatic circuit breaker
US2275795A (en) Electrical thermomotive device
US2111943A (en) Plug type circuit breaker
US2231599A (en) Electric fuse
US548904A (en) Automatic time cut-out