US1986553A - Electrically operated work cycle timer - Google Patents

Electrically operated work cycle timer Download PDF

Info

Publication number
US1986553A
US1986553A US575602A US57560231A US1986553A US 1986553 A US1986553 A US 1986553A US 575602 A US575602 A US 575602A US 57560231 A US57560231 A US 57560231A US 1986553 A US1986553 A US 1986553A
Authority
US
United States
Prior art keywords
circuit
switch
wire
contact
magnet
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
US575602A
Inventor
Herbert J Brandenburger
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.)
Crouse Hinds Co
Original Assignee
Crouse Hinds Co
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 Crouse Hinds Co filed Critical Crouse Hinds Co
Priority to US575602A priority Critical patent/US1986553A/en
Application granted granted Critical
Publication of US1986553A publication Critical patent/US1986553A/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
    • H01H61/00Electrothermal relays
    • H01H61/06Self-interrupters, i.e. with periodic or other repetitive opening and closing of contacts
    • H01H61/066Self-interrupters, i.e. with periodic or other repetitive opening and closing of contacts making use of an extensible wire, rod or strips

Definitions

  • This invention relates to work cycle timers and has for its object a timer in which the closing and opening of the work circuit or circuits to be timed, is controlled by the throwing of a g relay or double throw switch and the throwing of the switch timed by electrically operated means as heating elements controlled by the switch itself so that the timer 'includes no cams, drums, or any mechanism aside from the double throw switches and thermal switches or their equivalents.
  • Figure 1 is a diagrammatic view of this timer showing the same as timing the operation of signals.
  • Figure 2 is a diagrammatic view of a similar timer operating flashing signals, the light and dark periods of which are accurately timed.
  • This timer comprises generally a double throw switch or relay having a movable member normally arranged in one ofitstwo positions and movable into its normal position by any suitable means, as a spring, an electro-magnet for throwing the movable switch member into its second position, starting and stick circuits for the magnet connected respectively in the feed circuit through the movable switch member when respectively in its first and its second positions, the starting circuit being normally open and the stick circuit normally closed (disregarding the position of the movable switch member) and electrically operated timed means for timing the closing of the starting circuit to a predetermined interval and to time the opening of the stick circuit to a predetermined interval, the timing means for the starting circuit having a circuit connected in the feed circuit through the movable switch member when the latter is in its first position and the timing means of the stick circuit.
  • the wire 13 being shown as feeding a go to its second position and also a predetermined timed interval occurs before the stick circuit is broken by the timing means to permit the double throw switch to return to its starting position and the cycleto repeat.
  • the work circuits are connectable in the feed circuit through the double throw switch when in its first and second positions, one or some of them being connected in a closed circuit when the switch member is in its first position and others 1 when in its second position.
  • 1 designates the double throw switch
  • 2 the movable switch member thereof having terminals 3
  • 4. 5 and 6 designate one row of contacts with which the terminals 3 and 4 are engaged when l the member 2 is in its first or starting position.
  • 7 and 8 designate an opposite row of contacts with which the terminals 3, 4 are engaged when moved in one direction to hold the terminals 3, 4 30 Y engaged with the contacts 5, 6 by a spring 9.
  • 10 designates the electro-magnet arranged in juxtaposition to the switch member 2 to throw said switch member when the electro-magnet is energized.
  • 11 and 12 designate the wires of a as feed circuit
  • 13 and 14 are wires or legs of the work circuits connectable in the feed circuit through the double throw switch when the switch member 2 is in one or the other of its two 40 or green signal 15 on one street and a red signal 16 on an intersecting street, the circuit being completed through return wire 17.
  • the wire 14 r is shown as feeding red signal 18.0n the first 45 street and the green signal 19 on the intersecting street, this circuit being completed through return wire 17.
  • the wire 13 is connected in the feed circuit through the contact 5 of the double throw switch and the terminal 3 when the switch member 2 is in its first position.
  • the wire 14 is connected in the feed circuit through the contact 7 and the terminal 3 when the movable switch member is in its second position.
  • Themovable switch member k connected to the wire 11 of the feed circuit through conductor 20.
  • the starting, circuit for the magnet 10 has e normally open switch 21 therein having e. terminal 22normelly spaced from a; contect 23 which is connected by e wire 24 to one end of the coil of the magnet 16, the other end of the coil being connected to the wire 26.
  • the frame of the switch 21 is connected to a, return wire 25.
  • the electrically operated timing means is preferably as heating element arranged in juxtaposition to the switch 21 to heat and warp it when the heating coils ere energized, to cause the terminel 23 to engage the contect 23 and thus close the start:-
  • time required for the nesting element to worn the switch 21 sumcientiy to engage the tcrminui V 22 with the contect 23 is the time period that the worlr circuit is is closed end-the worh circuit 1% opened.
  • 26 designates the heating coil e1ectriconnected st one endto the frame oi the switch 21 and st its other end to e wire '2'? con nected to the contact 5.
  • switch 26 is nice preferably e thermelswitch and the timed opening thereof is eflected by rneens' of a hosting coil 33 connected at one end to the frame oi'the switch 26 and at its other end in the fwd circuit through the switch erm 2 when in its second position es through wire 36, contact 7 end terminal 3 oithe switch end position.
  • a, circuit is established through the coils of the magnet it as follows: from feed wire 11, wire 20, magnet 10, wire 24, contact 23, terminal 22 thence through the frame of the switch 21 to return wire 25,.
  • the switch member 2 is thrown to its second position, wherein-the terminals 3, d are engaged with the contests 8 and thus the circuit through the wire 16 and the heating coils 26 oil the normally open starting circuit switch 21 is broken and the work circuit 1% closed.
  • a stick circuit for the magnet 16 is established from teed wire 11, wire26, magnet 10, wire 32, contact 8 and terminal 4 through wire 31, thence through frame of the switch 28 to the return wire 25. Also, at the same time, the circuit is closed to the timing coil or heating element 33 from iced wire 11, wire 26, terminal 3 of the switch member 2, contact '1, wire 34 through the heating coil 33 thence through the frame of the switch 28 to the return wire 25.
  • the heating coll hosts
  • the feature of this invention is the timing for the closing of the various periods of the work cycle the muster relay and likewise timing the opening oi the stick circuit for the master relay, the timing means being controlled by the position of the movable member of the relay or double throw switch.
  • i 59 designstes the spring for returning the d 'ble throw switch to its normal position where ts sndofi.
  • 63 designates e work circuit-in which one or more terminals 56, More engaged with the co'r'itejct flashing lumps 66 are connected.
  • 65 is the return 66 is the normally open thermal. switch" in the contact 68 which is' connected by a. wire 69 to one end of the'coil of the magnet 60, the other end 1 or the coil being connected the feed line 61.
  • the current passes from the contact 55 through wire 7% and through the heating coil 72 and'the frame ol the switch 66 to return wire '73.
  • The; coils '72 heat and cause the switch 66 to warp.
  • a' starting. circuit for the magnet is established from wire 61 through'wire n, wire '10, through the coils of the end terminal 67 and through the frame of the niegnet 60, thence through wire 69, contact 68 switch 66 to the return wire 73.
  • the stick circuit is as follows: from wire 61, through wire 71, wire 70, coils of magnet 60, wire 75, contact 58, terminal 54, wire 76, to the contact 77 and terminal 78 of the normally closed switch 79 in the stick circuit and thence through return wire 80.
  • Suitable resistances 85 and 86 are connected in the starting and stick circuits in order to cut down the current carried by the heating coils.
  • the timing of the closing of the normally open switch 21 or 86 in the starting circuit may be adjusted or varied by separating more or less the contact 23 or 88 from the terminal 22 or 87;
  • the timing of the opening of the switch 28 or 79 in the stick circuit varied or adjustedby varying the mechanical pressure between the terminal 29 and contact 30 or between the contact 77 and terminal 78.
  • the contact 23 orosineachcaseisascrew whichcanbeturned in one direction or the other to vary the gap between it and the terminal 22 or 87 of the switch 21 or 66.
  • the contact 30 or 7'1 is a similar screw which can be tightened or loosened to press more or less against the terminal 29 or '18, it being understood that the switches are of resilient material, capable ofbeing tensioned.
  • a cycle timer for connecting the work circuits to the feed circuit including a double throw switch having a movable member normally arranged in one of its two positions, means for returning the movable member to its first position, an electromagnet for throwing the movable member into its second position, the work circuits being connectable to the feed circuit through the movable switch member when in one or the other of its positions, a starting circuit for the magnet, a stick circuit connected in the feed circuit through the double throw switch member when in its second position, a single, normally open switch in the starting circuit, a single, normally closed switch in the stick circuit, electrically operated timing means arranged to close the starting circuit switch and having a circuit connected to the feed circuit through the switch member, when in its first position and electrically operated means for opening the switch in the stick circuit and having a circuit connected to the feed circuit through the double throw switch member, when in its second position.
  • a cycle timer for connecting the work circuits in the feed circuit including a double throw switch having a movable member normally arranged in one of its two positions, means for returning the movable member to its first position, an electromagnet for throwing the movable member into its second position, the work circuits being connectable to the feed circuit through the movable switch member when in one or the other of its positions, a starting circuit ior the magnet, a stick circuit connected tothe feed circuit through the double throw switch member when in its second position, a single, normally open switch in the starting circuit, a single, normally closed switch in the stick circuit, electrically operated timing means arranged to close the starting circuit switch and having a circuit connected to the feed circuit through the switch member, when in its first position and electrically operated means for opening the switch in the stick circuit, and having a circuit connected to the feed circuit, through the double throw switch member when in its second position, the switches in the starting circuit and the stick circuit being thermal switches and the electrically

Description

Jan. 1, 1935. H. J. BRAN DENBURGER ,5
ELECTRICALLY OPERATED WORK CYCLE TIMER Filed Nov. 1?, 19:51
ATTORN EYS Patented Jan. I, 1935 UNITED STATES auzc'rmcsmr oraas'mp woax cross TIMER Herbert J. Brandenburger, St. Louis, 110., sssignor to Grouse-Hinds Company, Syracuse, N. Y.. a corporation of New York Application November 17, 1931, Serial No. 575,602
2 Claims. (Cl. 115-320) This invention relates to work cycle timers and has for its object a timer in which the closing and opening of the work circuit or circuits to be timed, is controlled by the throwing of a g relay or double throw switch and the throwing of the switch timed by electrically operated means as heating elements controlled by the switch itself so that the timer 'includes no cams, drums, or any mechanism aside from the double throw switches and thermal switches or their equivalents.
The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.
Indescribing this invention, reference is had to the accompanying drawing, in which like characters designate corresponding parts in all the views.
Figure 1 is a diagrammatic view of this timer showing the same as timing the operation of signals.
Figure 2 is a diagrammatic view of a similar timer operating flashing signals, the light and dark periods of which are accurately timed.
I have here illustrated my invention in its simplest form, in Figure 1 as adapted to time the display of tratlic signals on intersecting streets and in Figure 2 to time flashing signals.
This timer comprises generally a double throw switch or relay having a movable member normally arranged in one ofitstwo positions and movable into its normal position by any suitable means, as a spring, an electro-magnet for throwing the movable switch member into its second position, starting and stick circuits for the magnet connected respectively in the feed circuit through the movable switch member when respectively in its first and its second positions, the starting circuit being normally open and the stick circuit normally closed (disregarding the position of the movable switch member) and electrically operated timed means for timing the closing of the starting circuit to a predetermined interval and to time the opening of the stick circuit to a predetermined interval, the timing means for the starting circuit having a circuit connected in the feed circuit through the movable switch member when the latter is in its first position and the timing means of the stick circuit.
so the electro-magnet to throw the switch member positions, the wire 13 being shown as feeding a go to its second position and also a predetermined timed interval occurs before the stick circuit is broken by the timing means to permit the double throw switch to return to its starting position and the cycleto repeat. I
The work circuits are connectable in the feed circuit through the double throw switch when in its first and second positions, one or some of them being connected in a closed circuit when the switch member is in its first position and others 1 when in its second position.
1 designates the double throw switch, 2 the movable switch member thereof having terminals 3, 4. 5 and 6 designate one row of contacts with which the terminals 3 and 4 are engaged when l the member 2 is in its first or starting position. 7 and 8 designate an opposite row of contacts with which the terminals 3, 4 are engaged when moved in one direction to hold the terminals 3, 4 30 Y engaged with the contacts 5, 6 by a spring 9.
10 designates the electro-magnet arranged in juxtaposition to the switch member 2 to throw said switch member when the electro-magnet is energized. 11 and 12 designate the wires of a as feed circuit, and 13 and 14, are wires or legs of the work circuits connectable in the feed circuit through the double throw switch when the switch member 2 is in one or the other of its two 40 or green signal 15 on one street and a red signal 16 on an intersecting street, the circuit being completed through return wire 17. The wire 14 r is shown as feeding red signal 18.0n the first 45 street and the green signal 19 on the intersecting street, this circuit being completed through return wire 17. The wire 13 is connected in the feed circuit through the contact 5 of the double throw switch and the terminal 3 when the switch member 2 is in its first position. The wire 14 is connected in the feed circuit through the contact 7 and the terminal 3 when the movable switch member is in its second position.
Themovable switch member k connected to the wire 11 of the feed circuit through conductor 20.
The starting, circuit for the magnet 10 has e normally open switch 21 therein having e. terminal 22normelly spaced from a; contect 23 which is connected by e wire 24 to one end of the coil of the magnet 16, the other end of the coil being connected to the wire 26. The frame of the switch 21 is connected to a, return wire 25. The electrically operated timing means is preferably as heating element arranged in juxtaposition to the switch 21 to heat and warp it when the heating coils ere energized, to cause the terminel 23 to engage the contect 23 and thus close the start:-
ing circuit through the electro-rnegnet 1c. The
time required for the nesting element to worn the switch 21 sumcientiy to engage the tcrminui V 22 with the contect 23 is the time period that the worlr circuit is is closed end-the worh circuit 1% opened. 26 designates the heating coil e1ectriconnected st one endto the frame oi the switch 21 and st its other end to e wire '2'? con nected to the contact 5. V Y
The stick circuit for the electr c-magnet in= cludes to switch, es s thermel switch'zc' having a to 1:1. 1. 29 normally engaged with the contact 36 connected to one end oi the coil oi the magnet it through the double throw switch when in its second position, a through wire 3i, terminal 4 or the switch member 2, content 6 and wire 32. The other end oi the coil 1o oi the magnet, es before ststed, is connected to the wireuo. The
switch 26 is nice preferably e thermelswitch and the timed opening thereof is eflected by rneens' of a hosting coil 33 connected at one end to the frame oi'the switch 26 and at its other end in the fwd circuit through the switch erm 2 when in its second position es through wire 36, contact 7 end terminal 3 oithe switch end position.
' Theoperation of the term shown in Figurei is as follows: Assuming that the feed circuits ii and 12 are closed in any suitable manner, es by e, swmh, the current flows as follows: from iced wire 1i,.wire 20, terminal 3 oi the switch member 2, contect 5, then through the work circuit 13 l through the signals 16, 16 or other electroresponare devices, thence through the return wire it to the feed wire 12. At the some time, the current is messing through wire 27 through the heating coil 26 of the normally open switch 21 in the start his circuit, and after it hosts the coil 26 camelently to engage the terminal 22 with the contact 4 23. a, circuit is established through the coils of the magnet it as follows: from feed wire 11, wire 20, magnet 10, wire 24, contact 23, terminal 22 thence through the frame of the switch 21 to return wire 25,. immediately upon the closing of the starting circuit, the switch member 2 is thrown to its second position, wherein-the terminals 3, d are engaged with the contests 8 and thus the circuit through the wire 16 and the heating coils 26 oil the normally open starting circuit switch 21 is broken and the work circuit 1% closed.
At the some time a stick circuit for the magnet 16 is established from teed wire 11, wire26, magnet 10, wire 32, contact 8 and terminal 4 through wire 31, thence through frame of the switch 28 to the return wire 25. Also, at the same time, the circuit is closed to the timing coil or heating element 33 from iced wire 11, wire 26, terminal 3 of the switch member 2, contact '1, wire 34 through the heating coil 33 thence through the frame of the switch 28 to the return wire 25. As the heating coll hosts,
it warps the switch 26 separating the terminal 29 member when in its secwire. the starting circuit for the magnet 6.0, this switch having a terminal 67 normally spaced apart from nee-uses end contact to, time breaking the stick circuit so thet the magnet 10 is tie-energized and the spring 9 tree to react and return the switch memb 2 to its starting position and the cycle to repeat as long he the feed circuit is closed. Although the work circuits are here shown as connected directly to signals, thework circuits leading from the opposite rows of contacts of the double throw switch may control other electrical devices, which in turn control elements as signals. 1
The feature of this invention is the timing for the closing of the various periods of the work cycle the muster relay and likewise timing the opening oi the stick circuit for the master relay, the timing means being controlled by the position of the movable member of the relay or double throw switch.
in other words, the movable switch member,
when in one of its two positions, cuts in one timer and cuts out the other, and when in the other of its two positions, cuts out the first timer and cuts in the second, end the operation of the switch member, or the energization of its magnet, is conby timing the closing of the starting circuit for contact :56 being a, dead one, as is thecontecto in "Figure 1'.
i 59 designstes the spring for returning the d 'ble throw switch to its normal position where ts sndofi.
co designates the electro-magnet for throwing the switch 51 against the 'actionof' its returning spring 59. 61 end 62 designate the feed wires.
63 designates e work circuit-in which one or more terminals 56, More engaged with the co'r'itejct flashing lumps 66 are connected. 65 is the return 66 is the normally open thermal. switch" in the contact 68 which is' connected by a. wire 69 to one end of the'coil of the magnet 60, the other end 1 or the coil being connected the feed line 61.
- '72'designetes the heating element or coil arranged in juxtaposition to the switch 66, the coil being electrically connected at one end to the frame of the switch which is connected toreturn wire 73, cind'the other end of the heating coil Ming electriceily connected through efwire- 74' to wires '70 and '71 to' to the contact 55' of the double throw:- switch, Thus, initially the current posses from'the'feed wire 61 through wire 71 to terminalv53,-thence through contact 55 thence through work circuit 63 and lamp or lamps therein to the retu'rnfwire 65. Also, the current passes from the contact 55 through wire 7% and through the heating coil 72 and'the frame ol the switch 66 to return wire '73. The; coils '72 heat and cause the switch 66 to warp. When the switch warps sufficiently to en gsge the terminal 67 with contact 68, a' starting. circuit for the magnet is established from wire 61 through'wire n, wire '10, through the coils of the end terminal 67 and through the frame of the niegnet 60, thence through wire 69, contact 68 switch 66 to the return wire 73. When the magnet 80 is thus energized it throws the double throw switch to carry the terminal 53 into engagement with the contact 57 and the terminal 54 into engagement with the contact 58, thus breaking the work circuit and also the circuit through the heating coil 72 and establishing a stick circuit to hold the magnet energized for a timed period and hence timing the interval that the lights are extinguished. The stick circuit is as follows: from wire 61, through wire 71, wire 70, coils of magnet 60, wire 75, contact 58, terminal 54, wire 76, to the contact 77 and terminal 78 of the normally closed switch 79 in the stick circuit and thence through return wire 80. At the same time, a circuit is established through the heating coils 81 of the switch 79 from wire 61 through wire 71, terminal 53,0f the double throw switch, contact 57, wire 82 through the heating coils 81, one end of which is connected to the frame of the switch 79 and the other end to the wire 82. When the coils are heated suihciently to separate the terminal 78 from the contact 77, the stick circuit is broken and the double throw switch returns to its starting position under the action of the spring 59 and the cycle repeats.
Suitable resistances 85 and 86 are connected in the starting and stick circuits in order to cut down the current carried by the heating coils.
The timing of the closing of the normally open switch 21 or 86 in the starting circuit may be adjusted or varied by separating more or less the contact 23 or 88 from the terminal 22 or 87; and
the timing of the opening of the switch 28 or 79 in the stick circuit varied or adjustedby varying the mechanical pressure between the terminal 29 and contact 30 or between the contact 77 and terminal 78. As seen in Figure 2 the contact 23 orosineachcaseisascrewwhichcanbeturned in one direction or the other to vary the gap between it and the terminal 22 or 87 of the switch 21 or 66. Also, the contact 30 or 7'1 is a similar screw which can be tightened or loosened to press more or less against the terminal 29 or '18, it being understood that the switches are of resilient material, capable ofbeing tensioned.
Although I have illustrated my invention as in its simplest form, it may be embodied in more or less complex form in connection with other instruments or to control other relays but in any case,'-the essential feature is the timing of the closing of the starting circuit and the timing of the opening of the stick circuit by electrically operated means controlled by or connected-in a feed circuit through the relay or double throw switch.
What I claim is:
1. The combination with a feed circuit and work circuits to be timed; of a cycle timer for connecting the work circuits to the feed circuit including a double throw switch having a movable member normally arranged in one of its two positions, means for returning the movable member to its first position, an electromagnet for throwing the movable member into its second position, the work circuits being connectable to the feed circuit through the movable switch member when in one or the other of its positions, a starting circuit for the magnet, a stick circuit connected in the feed circuit through the double throw switch member when in its second position, a single, normally open switch in the starting circuit, a single, normally closed switch in the stick circuit, electrically operated timing means arranged to close the starting circuit switch and having a circuit connected to the feed circuit through the switch member, when in its first position and electrically operated means for opening the switch in the stick circuit and having a circuit connected to the feed circuit through the double throw switch member, when in its second position.
2. The combination with a feed circuit and work circuits to be timed; of a cycle timer for connecting the work circuits in the feed circuit including a double throw switch having a movable member normally arranged in one of its two positions, means for returning the movable member to its first position, an electromagnet for throwing the movable member into its second position, the work circuits being connectable to the feed circuit through the movable switch member when in one or the other of its positions, a starting circuit ior the magnet, a stick circuit connected tothe feed circuit through the double throw switch member when in its second position, a single, normally open switch in the starting circuit, a single, normally closed switch in the stick circuit, electrically operated timing means arranged to close the starting circuit switch and having a circuit connected to the feed circuit through the switch member, when in its first position and electrically operated means for opening the switch in the stick circuit, and having a circuit connected to the feed circuit, through the double throw switch member when in its second position, the switches in the starting circuit and the stick circuit being thermal switches and the electrically operated means therefor being heating coils arranged in juxtaposition to the switches respectively to heat and warp. the same when the circuits thereof are closed, to close the starting circuit and open the stick circuit.
HERBERT J. BRANDENBURGER.
US575602A 1931-11-17 1931-11-17 Electrically operated work cycle timer Expired - Lifetime US1986553A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US575602A US1986553A (en) 1931-11-17 1931-11-17 Electrically operated work cycle timer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US575602A US1986553A (en) 1931-11-17 1931-11-17 Electrically operated work cycle timer

Publications (1)

Publication Number Publication Date
US1986553A true US1986553A (en) 1935-01-01

Family

ID=24300964

Family Applications (1)

Application Number Title Priority Date Filing Date
US575602A Expired - Lifetime US1986553A (en) 1931-11-17 1931-11-17 Electrically operated work cycle timer

Country Status (1)

Country Link
US (1) US1986553A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2630167A (en) * 1950-10-27 1953-03-03 Farspan Ind Inc Burner igniton and control system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2630167A (en) * 1950-10-27 1953-03-03 Farspan Ind Inc Burner igniton and control system

Similar Documents

Publication Publication Date Title
US3781853A (en) Navigational light system
US2282956A (en) Direction signal system
US1986553A (en) Electrically operated work cycle timer
US2166721A (en) Traffic signal system
US2754392A (en) Circuit interrupter
US1868500A (en) Electrical circuit controlling mechanism
US2315920A (en) Impulse operated selector switch for alternating and direct current
US2056619A (en) Electric discharge device
US1214771A (en) Time-switch.
US2447037A (en) Signal system
US2332492A (en) Starting switch
US2501017A (en) Photographic light control device
US2103334A (en) Means for dimming radio lights
US1973603A (en) Cycle timer for controlling work circuits
US1568025A (en) walxek
US1979824A (en) Switch
US2071494A (en) Traffic signaling system
US2573076A (en) Electric sign circuit
US2429966A (en) Monitoring system
US553198A (en) stickle
US2729769A (en) Starting and operating circuits for fluorescent lamps
US2797400A (en) Traffic light control mechanism
US2182130A (en) Time delay relay
DE655357C (en) Traveling light advertising
US2045883A (en) Control for oil burners or similar apparatus