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US2301992A - Electrical relay - Google Patents

Electrical relay Download PDF

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Publication number
US2301992A
US2301992A US396737A US39673741A US2301992A US 2301992 A US2301992 A US 2301992A US 396737 A US396737 A US 396737A US 39673741 A US39673741 A US 39673741A US 2301992 A US2301992 A US 2301992A
Authority
US
United States
Prior art keywords
armature
relay
permanent magnet
backstrap
core
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
US396737A
Other languages
English (en)
Inventor
Norman F Agnew
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.)
Hitachi Rail STS USA Inc
Original Assignee
Union Switch and Signal Inc
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 to BE477703D priority Critical patent/BE477703A/xx
Application filed by Union Switch and Signal Inc filed Critical Union Switch and Signal Inc
Priority to US396737A priority patent/US2301992A/en
Application granted granted Critical
Publication of US2301992A publication Critical patent/US2301992A/en
Priority to FR950949D priority patent/FR950949A/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/22—Polarised relays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/01—Relays in which the armature is maintained in one position by a permanent magnet and freed by energisation of a coil producing an opposing magnetic field

Definitions

  • My invention relates to electrical relays, and particularly to electrical relays suitable for use in centralized trafiic controlling systems for railroads.
  • One object of my invention is to provide an inexpensive relay of simple, rugged and compact construction having an armature which is moved to an attracted position by operating current of a predetermined polarity only, and which armature is subsequently held in its attracted position until operating current having a polarity opposite to that which moved it to its attracted position is supplied to the relay.
  • Another object of my invention is to provide inexpensive means for converting a neutral relay of the type described in Letters Patent of the United States No. 1,815,947, granted to Lloyd V. Lewis on July 28, 1931, into the equivalent of a polar stick relay, whereby manufacturing costs, and the number of maintenance parts required by railroads using both types of relays are reduced.
  • a further object of my invention is to provide a relay of the magnetic stick type which is capable of reliably operating a larger number of contacts than is generally available on polar stick relays, and which is suitable for use as an indica tion relay in a centralized trafiic control system such as that shown and described in Letters Patent of the United States No. 2,197,130, granted to Lloyd V. Lewis on April 16, 1940.
  • Relays embodying my invention are generally referred to as being of the L type, and in accordance with my invention each relay comprises an L-shaped backstrap of magnetizable material to the short leg of which is secured one pole of a permanent magnet. The other pole of the permanent magnet is spaced from the long leg of the backstrap to provide a magnetic leakage path,
  • magnetizable core which extends parallel to the long leg and is surrounded by the operating winding of the relay.
  • the free end of the magnetizable core cooperates with the relay armature whichis pivoted to the long leg of the backstrap and is operatively connected with contacts mounted on the backstrap.
  • the parts are so proportioned that the armature will be moved toward the magnetizabl cor to an attracted position by operating current of a predetermined polarity only supplied to the operat-
  • the parts are further so proportioned that the magnetic leaka e path which is provided between the said other pole of the permanent magnet and the backstrap will act to provide a return path to the backstrap for fiux from the coil when the flux due to current in the coil is in the direction to tend to demagnetize the permanent magnet, whereby the permanent magnet i caused to maintain its initial strength throughout the useful life of the relay.
  • Fig. 1 is a View showing in side elevation one form of relay em bodying my invention.
  • Fig. 2 is a top plan View of the relay shown in Fig. 1.
  • Fig. 3 is an end View of the permanent magnet 3 forming part of the relay shown in Figs. 1 and 2.
  • Fig. 4 is a detail View of the washer 8 forming part of the relays shown in Figs. 1 and 2.
  • the relay in the form here illustrated comprises an L-shaped backstrap B of magnetizable material having a short leg I and a long leg 2.
  • a permanent magnet 3 having a high coercive force preferably of the Alnico type, is cast with a through slot 4 (see Fig. 3) for the reception of the shank of a screw 5 which extends through a hole in the short leg I and is screwed at its free end into a screw threaded hole 6 provided in one end of a magnetizable core I.
  • Interposed between the permanent magnet and the short leg l is a magnetizable washer 8
  • interposed between the permanent magnet and the core l is a magnetizable washer
  • the washer 8 is rectangular in form and is provided with a through hole it) and with a flange H which extends at right angles to the lower end of the washer.
  • Th hole 26 receives the screw 5, and the parts are so proportioned that when the screw is in the hole ii the upper edge of the washer will engage the underside of the long leg 2 of the backstrap B, whereby the washer 8 is prevented from turning.
  • the parts are further so proportioned that when the screw 5 is in the bottom of th slot 6, the flange l I will act as a support to hold the magnet in place.
  • the washer 9 is similar to the washer 8 except for its upper edge i2 which is bent over to provide a magnetic leakage path between the backstrap and the permanent magnet, or the backstrap and the core. under certain conditions which will be described hereinafter. It will be obvious that the washer fl assists the washer 8 in holding the permanent magnet 3 in its proper vertical position.
  • the core I extends parallel to the long leg 2 of the backstrap B, and is surrounded by an energizing winding l3 held in place by a cotter key M extending through a hole [5 provided in the core adjacent its outer end.
  • An L-shaped armature A of suitable magnetizable material is pivotally mounted at the free or forward end of the long leg 2 of the backstrap 3 for swinging movement toward or away from the free end of the core I to an attracted or a released position.
  • a plate IE of insulating material is attached to the upper leg of the armature, and this plate extends rearwardly along the backstrap and cooperates with the relay contacts.
  • the relay contacts are arranged in stacks, and are supported by a metal plate I! which is attached to the long leg 2 of the backstrap by screws 8.
  • the stacks may be readily varied to provide a wide variety of contact combinations, and as here shown are similar to those described in detail in the aforementioned Lewis Patent No. 1,815,947.
  • the two outer stacks J and L each include a terminal strip 28 or 28a to which the coil leads are attached, while the middle stack K comprises a movable contact finger 2
  • the finger 2i cooperates with fixed front and back contact fingers 22 and 23, and is so adjusted that it exerts a force on the armature which biases the armature toward its released position, and that when the armature occupies its released position, it will engage the fixed back contact fingers to close a back contact 2 l-23, but that, when the armature is moved to its attracted position, the contact finger 2! will be moved out of engagement with the fixed back contact finger and into engagement with the fixed front contact finger to open the back contact 2 L43 and to close a front contact 2l-22.
  • the leakage path provided by the washer 9 serves as a part of the return path for the flux set up in the core 1, so that only a relatively small amount of this flux traverses the return path provided by the permanent magnet. This is important because it prevents demagnetization of the permanent magnet due to the en ergization of the operating winding, and insures permanence in the calibration values of the relay.
  • Relays embodying my invention are particularly useful to replace electrical stick relays for in-- dication purposes in centralized traflic control systems.
  • magnetic stick provided by the permanent magnet eliminates the stick contact and its wiring as well as saving on battery drain, which makes it more economical than an electrical stick relay.
  • Another advantage of a relay embodying my invention is that a standard inertia contact such as that shown in my prior Patent No. 2,205,556, granted July 2, 1940, may be used for ringing approach and power-off bells.
  • a relay comprising an L-shaped backstrap having a long leg and a short leg, a bar type permanent magnet provided with a longitudinal slot, a screw extending through the short leg of said backstrap and through said slot and screwed into a core extending parallel to the long leg of said backstrap, an energizing winding on said core, a first magnetizable washer interposed between said magnet and said short leg of said backstrap and engaging the long leg of said backstrap to prevent said washer from turning and provided with means extending underneath said permanent magnet in supporting relation thereto, a second magnetizable washer interposed between said magnet and said core and provided with means extending underneath said magnet in supporting relation thereto and with other means which cooperates with the long leg of said backstrap to provide a leakage path for flux from said permanent magnet and a return path for flux induced in said core to prevent demagnetization of said magnet by energization of said coil in the direction to oppose the permanent magnet flux, an armature pivotally attached to the long leg of said back

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Electromagnets (AREA)
US396737A 1941-06-05 1941-06-05 Electrical relay Expired - Lifetime US2301992A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE477703D BE477703A (fr) 1941-06-05
US396737A US2301992A (en) 1941-06-05 1941-06-05 Electrical relay
FR950949D FR950949A (fr) 1941-06-05 1947-08-04 Perfectionnements aux relais électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US396737A US2301992A (en) 1941-06-05 1941-06-05 Electrical relay

Publications (1)

Publication Number Publication Date
US2301992A true US2301992A (en) 1942-11-17

Family

ID=23568437

Family Applications (1)

Application Number Title Priority Date Filing Date
US396737A Expired - Lifetime US2301992A (en) 1941-06-05 1941-06-05 Electrical relay

Country Status (3)

Country Link
US (1) US2301992A (fr)
BE (1) BE477703A (fr)
FR (1) FR950949A (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452034A (en) * 1944-10-06 1948-10-26 Walter H Campbell Electrical drop signal device
US2479231A (en) * 1945-06-06 1949-08-16 Automatic Elect Lab Alternating current relay
US2535977A (en) * 1949-09-27 1950-12-26 Gen Railway Signal Co Magnetic stick relay
US2557424A (en) * 1947-03-07 1951-06-19 North American Aviation Inc Directional circuit protector
US2916584A (en) * 1957-05-24 1959-12-08 Filtors Inc Electrically-operated latching relays

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452034A (en) * 1944-10-06 1948-10-26 Walter H Campbell Electrical drop signal device
US2479231A (en) * 1945-06-06 1949-08-16 Automatic Elect Lab Alternating current relay
US2557424A (en) * 1947-03-07 1951-06-19 North American Aviation Inc Directional circuit protector
US2535977A (en) * 1949-09-27 1950-12-26 Gen Railway Signal Co Magnetic stick relay
US2916584A (en) * 1957-05-24 1959-12-08 Filtors Inc Electrically-operated latching relays

Also Published As

Publication number Publication date
BE477703A (fr)
FR950949A (fr) 1949-10-11

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