US3742405A - Small high current dc relay structure - Google Patents

Small high current dc relay structure Download PDF

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Publication number
US3742405A
US3742405A US00277202A US3742405DA US3742405A US 3742405 A US3742405 A US 3742405A US 00277202 A US00277202 A US 00277202A US 3742405D A US3742405D A US 3742405DA US 3742405 A US3742405 A US 3742405A
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United States
Prior art keywords
armature
core part
contact
relay
stationary
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
US00277202A
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English (en)
Inventor
R Hayden
Donald D Mac
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.)
Northrop Grumman Space and Mission Systems Corp
Original Assignee
TRW Inc
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Filing date
Publication date
Application filed by TRW Inc filed Critical TRW Inc
Application granted granted Critical
Publication of US3742405A publication Critical patent/US3742405A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H50/00—Details of electromagnetic relays
    • H01H50/54—Contact arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00—Contacts
    • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
    • H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
    • H01H1/18—Contacts characterised by the manner in which co-operating contacts engage by abutting with subsequent sliding

Definitions

  • ABSTRACT A small high-current DC relay having a closed-loop magnetic core divided by two core gaps into a stationary and a movable core part; a spring armature pivotally connecting the core parts; and a coil mounted on the stationary core part.
  • the armature is formed of a single strip of electrically conductive spring material and includes an anchorage end portion secured to the stationary core part, a supporting portion rigidly secured to the movable core part, an arcuate fulcrum portion connecting the supporting and anchorage portions and defining a sole fulcrum about which the movable core part can pivot through a first angle, a free contact portion at the other end of the armature and carrying a contact, and a flexible arm portion connecting the contact and supporting portions and defining a second angle of pivotal movement of the contact portion about the fulcrum, smaller than the. first angle.
  • the difference between the two pivotal angles will bow the flexible arm portion, wiping the contact across a co-operating stationary contact upon closing and opening of the contacts.
  • the relay in all cases will comprise a movable armature with switch contacts thereof and having a pivot point, the armature being movable about the pivot as a result of magnetic flux generated by a relay coil.
  • the coil may be located between the pivot and contacts, or secondly the pivot may be located between the coil and the contacts, or lastly the contacts may be located between the coil and the pivot point.
  • Prior miniature heavy current DC relays have all been of the first type with the coil between the pivot and contacts.
  • Another object of the invention is the provision of such a relay which is further characterized by an extremely long and reliable service life as compared with prior known constructions.
  • Still another object of the invention is the provision of such a relay which is formed in such a manner as to permit assembly of its components in a simple and rapid manner.
  • FIG. I is an elevational view showing one form of relay constructed according to the present invention with parts thereof removed for clarity;
  • FIG. 2 is an elevational view similar to FIG. 1 showing a modified form of the invention
  • FIG. 3 shows schematically pivotal movement of the relay armature of FIGS. 1 and 2;
  • FIG. 4 is an enlarged elevational view showing in detail relative movement between the contacts of a further modified embodiment of the invention similar to that in FIG. 1 but defining a double-throw relay;
  • FIG. 5 is a greatly enlarged perspective view of the relay of FIG. 1;
  • FIG. 6 is an enlarged elevational view of the armature of the inventive relay shown schematically.
  • a high current relay according to the present invention is shown as comprising a base 10 of a suitable insulation material such as a phenolic resin or the like and upon which is mounted a core formed from a strip of ferrous material of uniform width and thickness.
  • the magnetic core includes a lower, stationary core part generally designated by reference numeral 12 and rigidly secured to the base 10, which core part is generally Ushaped in configuration and includes a first or coil-supporting upstanding straight leg 14 having a free upper end 16 and a second or armaturesupporting upright leg 18 likewise having a free upper end.
  • the magnetic core further includes an upper, movable Z-shaped core part 20 formed from said strip material defining a generally horizontal leg 22 having its free end spaced from the upper or free end 16 of the coil-supporting leg 14 by a first core gap24 and a depending leg 26 having its lower end spaced from the upper or free end of the armature-supporting leg 18 by a second core gap 28.
  • An electromagnetic coil winding 30 mounted on spool 32 is in turn mounted upon and surrounds the coil-supporting leg 14 of the lower or stationary core part 12, and it will therefore be evident that the above-described two parts of the magnetic core define a loop-like core of generally rectangular configuration forming a closed magnetic flux circuit and divided by the core gaps 24 and 28 into the two core parts, the coil winding 30 when energized providing magnetic flux for such magnetic flux circuit.
  • the spring armature member 34 is preferably formed from a single continuous strip of the spring material and includes a depending anchorage end portion 36, a support portion 38 extending generally perpendicular thereto outwardly from the magnetic core, an arcuate spring fulcrum portion 40 connecting the anchorage end and support portions, a free contact portion 42 at the outer or free end of the armature, and a free flexible arm portion 44 extending between and connecting the free contact portion 42 and the support portion 38.
  • the depending anchorage end portion 36 is rigidly secured to the armaturesupporting leg 18 of the stationary core part 12, while the free contact portion 42 of the spring armature member carries a contact 46 defining the movable contact of the relay.
  • the spring armature member 34 may be secured to the armature-supporting leg 18 by conventional rivets or the like, it is preferred, in constructing the inventive relay, that the armaturesupporting leg be provided with outward protrusions or dimples, as by center-punching, which are received within corresponding openings in the anchorage end portion 36 of the armature member, and that such pro trusions or dimples then be struck to form headed portions which securely retain the armature member in place on the leg 18.
  • the movable core part 20 further includes an outwardly extending leg 48 generally perpendicular to the depending leg 26 thereof, thus defining a generally Z- shaped movable core member, such outwardly extending leg 48 being rigidly secured by rivets or other suitable means to the support portion 38 of the spring armature member 34 adjacent the beginning of the arcuate fulcrum portion 40 thereof.
  • the movable core part 20 will be pivotally mounted relative to the stationary core part 12 about a pivot zone defined essentially by the arcuate fulcrum portion 40 of the armature member 34, and will be biased by the the armature member upwardly away from the coil-supporting leg 14, i.e., towards the position shown in solid lines.
  • the armature member 34 consists of a ferrous material, such as spring steel, it will effectively bridge or close the second core gap 28 by virtue of the arcuate fulcrum portion 40 thereof physically connecting the stationary and movable core parts 12 and 20. In this case, the magnetic core will effectively have only a single core gap 24.
  • a stationary contact 50 is mounted upon the base adjacent the movable contact 46 by a suitable upstanding bracket 52, such bracket preferably being of an electrically conductive material, and in the inactivated condition of the relay this stationary contact 50 is spaced from the movable contact 46 by a contact gap 54.
  • the location of the upper end 16 of coil-supporting arm 14 and the spring characteristics of the spring fulcrum portion 40 of the armature will define for the free end of the movable core part a first pivotal angle of motion 0,, about the fulcrum defined by fulcrum portion 40.
  • the contact gap 54 and fulcrum portion 40 will define for the free flexible arm portion 44 and hence for the contact portion 42, a second pivotal angle of motion 6 about such fulcrum smaller than the value of angle 0,.
  • the movable contact 46 will engage the stationary contact 50 prior to engagement of the movable core part 20 with the upper end 16 of the stationary core part, i.e., as the movable core part 20 pivots through an angle substantially equal to 0
  • the movable core part will then continue to pivot through the remainder of angle 0,, until it engages or abuts against such upper end 16; however, the movable contact 46 is prevented from further outward movement by the presence of the stationary contact 50, and hence the flexible arm portion 44 of the spring armature will bow outwardly, as clearly shown in dashed lines in FIG. 1.
  • the above sequence will be re versed, namely, the movable core part 20 will start to pivot in the clockwise direction away from the stationary core part 12 under the influence of the spring armature; during the initial movement thereof, the movable contact 46 will remain urged against the stationary contact 50 and, as the spring armature becomes progressively less bowed, will slide or wipe downwardly against such stationary contact until the bowing compressional forces on the armature are relieved, i.e., until the movable core part 20 reaches an angle from its solid-line position substantially equal to angle-0 and the armature resumes its original or unstressed shape and effec' tive length, at which point the flexible arm portion 44 and the movable contact 46 will return to their original positions, shown in solid lines, by pivotal movement through the angle 6 about the fulcrum portion 40.
  • While the spring armature 34 is shown in FIG. 1 as having its free flexible arm portion 44 bent generally perpendicular to the support portion 38 so as to depend therefrom for maximum compactness of the relay construction, where space requirements are not critical the modified embodiment shown in FIG. 2 may be utilized.
  • This modified construction is identical in structure and function with that described with reference to FIG. 1 except that the free contact portion 42 and the free flexible arm portion 44 are generally colinear with the support portion 38 and form a straight continuous extension thereof, such that the pivotal movement of the contact portion 42 is in a generally vertical rather than horizontal direction.
  • the stationary contact 50 is mounted on a modified upright support bracket 52a having a horizontally extending upper portion 56, to which the contact 50 is secured in the path of movement of the movable contact 46.
  • the contact gap 54 being smaller in width than the gap 24 between the movable core part 20 and the leg 14 of the stationary core part 12, will limit angular pivotal movement of the free contact portion 42 of the armature about the fulcrum portion 38 thereof to a smaller angle than that of the horizontal leg 22 of the movable core part.
  • the coil 30 when the coil 30 is energized, the resulting angular pivotal movements of the leg 22 and of the free flexible arm portion 44 will cause the latter to bow upwardly as shown in dashed lines in FIG. 2, effectively shortening its length and providing a transverse wiping or sliding movement of the movable contact 46 across the stationary contact 50 as indicated by the double arrow.
  • FIG. 4 there is shown in detail the manner in which the free contact portion 42 of the armature member 34 flexes or bows between the open and closed positions of FIG. 1, it being evident that the arrangement of FIG. 2 is identical therewith except for the specific orientation of such free contact portion and the two contacts.
  • FIG. 4 further illustrates the manner in which the inventive relay as described above may be readily adapted to provide a double-throw switching action through the addition of a respective further stationary and movable contact.
  • the free contact portion 42 has secured thereto a second movable contact 56, preferably directly opposite the previously described movable contact 46, which co-operates with and normally engages a second stationary contact 58 mounted on a suitable upright support or bracket 60 generally similar to the bracket 52 and spaced therefrom, thereby defining a normally closed contact pair as shown in solid lines in this figure.
  • bracket 60 and stationary contact 58 are so located relative to the free contact portion 42 of the armature 34 that the latter, due to its own spring resilience and particularly that of its fulcrum portion 40, biases the movable contact 56 into engagement with the stationary contact 58 with sufficient pressure to effect a reverse or inward bowing of the armature member, as shown in solid lines, when the coil 30 is nonenergized.
  • Energization of the coil will effect pivotal movement of the free contact portion 42 and the contact 46 into engagement with the other stationary contact 50, effecting an outward bowing of the armature, as shown in dashed lines, and a corresponding sliding or wiping movement of the movable contact 46 upwardly across the stationary contact 50.
  • the second movable contact 56 will exhibit a similar upward wiping or sliding movement across the second stationary contact 58 prior to disengagement or opening of these latter contacts.
  • Reverse pivotal movement of the armature member 34 in a similar manner, will effect a downward wiping movement, in succession, of the two movable contacts across the respective stationary contacts.
  • suitable electrical terminals are secured to the base and extend downwardly therefrom, for connecting the coil and the contacts 46 and 50 (as well as the additional contact 58 of FIG. 4, in the case of a double-throw relay) into appropriate circuitry.
  • a first depending terminal 62 is electrically connected to the stationary contact 50 through the conductive bracket 52
  • a second depending terminal 64 is connected to one lead 66 of the coil 30
  • a third depending terminal 68 is connected jointly to the other lead (not shown) of the coil and to the anchorage portion 36 of the conductive spring armature 34, the latter in turn conducting current to the movable contact 46 secured to the end thereof.
  • the coil or actuating circuit extends across terminals 64 and 68, while the contact or relaycontrolled circuit is connected across terminals 62 and 68.
  • an additional terminal it will of course be understood that an additional terminal,
  • the armature member 34 pivots about a fulcrum defined solely by itself, or more particularly, by the spring fulcrum portion 40 thereof, and hence does not require an exterior or separate fulcrum-defining structure such as has been characteristic of prior known relay structures, shear forces are substantially eliminated and thus the inventive relay is characterised by a much longer service life and corresponding reliability than has heretofore been possible, providing well over 150,000 cycles without structural failure and possibly of an order approaching 1 million operating cycles.
  • the relay may be rapidly assembled in a simple manner particularly suitable for use with automatic assembly apparatus.
  • the mounting of the coil winding 30 and spool 32 upon one of the straight upstanding legs, shown as leg 14, of the generally U- shaped stationary core part 12 enables a significant part of the magnetic core and the armature to be preassembled prior to mounting of the coil 30.
  • the stationary core part 12 may be formed into its illustrated shape, the coil 30 mounted on leg 14 thereof, and then the movable core part 20 and the armature 34, advantageously preformed as a single subassembly unit, may then be secured by the anchorage portion 36 of the armature to the other leg 18 of the stationary core part.
  • prior constructions utilizing a stationary magnetic core at least partially surrounding the coil have required that the coil be wound upon the unformed blank of the core and then the latter bent or otherwise formed into shape, thus requiring a considerably more difficult operation as well as raising the danger of mechanical damage to the comparatively delicate coil winding.
  • the inventive relay construction comprises in its basic form a stationary core part 12; a movable core part. 20'separated therefrom by a pair of core gaps 24 and 28 to define therewith a generally rectangular twopart magnetic core forming a closed magnetic flux circuit; a relay armature 34 formed of a single continuous strip of conductive spring material and defining an anchorage end portion 36 secured to the stationary core part 12, a curved spring fulcrum portion 40 adjacent to the anchorage end portion 36 and defining the sole fulcrum means for the armature, a support portion 38 adjacent the fulcrum portion and rigidly secured to the movable'core part 20, maintaining the latter spaced from the stationary core part 12 by the core gaps 24 and 28 and mounting the movable core part for pivotal movement about the stationary core part through a first angle 6,, a free contact portion 42 carrying movable contact 46, and a free flexible arm portion 44 connecting the contact portion 42 to the support portion 38 and being pivotally movable about the fulcrum portion
  • a small DC relay for large currents and comprising: a stationary core part entirely defined by a single strip of ferrous material of uniform width and thickness; a movable core part formed of a further strip of said ferrous material and having a free end and adapted with said stationary core part to form a closed magnetic flux circuit therewith and when spaced therefrom to define first and second core gaps therebetween; a relay armature formed of a single strip of current conducting spring material of uniform section and having an anchorage end portion fixed to said stationary core part, a curved spring fulcrum portion forming the sole fulcrum of said relay armature and located next said anchorage portion, a support portion next said fulcrum portion and fastened rigidly to said movable core part and supporting the latter to defind a first pivotal angle of motion of the free end of said movable core part about said fulcrum, a free contact portion, and a free flexible arm portion between said contact portion and said support portion defining a second pivotal angle of motion of said flexible arm portion about said ful
  • a small DC relay as claimed in claim 2 further comprising a'movable contact mounted on said contact portion of said armature and a stationary contact normally spaced therefrom by a distance less than said one of said core gaps, whereby closing of said contacts by energization of said relay coil will flow said flexible arm portion of said armature and effect a transverse wiping movement of said movable contact across said stationary contact,
  • a small DC relay as claimed in claim 1 wherein said armature is generally U-shaped, said free flexible arm portion and said free contact portion of said armature being bent generally perpendicular to said support portion thereof 5.
  • said movable core is generally L-shaped andcomprises first and second generally perpendicular legs, said first leg extending generally horizontally and having a free end defining said free end of said movable core part, said second leg being secured to and depending from said first leg; and further comprising a further leg.se cured to the lower end of said second leg and extending generally parallel to said first leg and offset therefrom to define a generally Zshaped movable core member, said further leg being secured to said support portion of said armature, said intermediate portion of said movable core part comprising the juncture of said second leg and said further leg.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Electromagnets (AREA)
US00277202A 1972-03-06 1970-08-02 Small high current dc relay structure Expired - Lifetime US3742405A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA136,486A CA953758A (en) 1972-03-06 1972-03-06 Small high current dc relay structure

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US3742405A true US3742405A (en) 1973-06-26

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US00277202A Expired - Lifetime US3742405A (en) 1972-03-06 1970-08-02 Small high current dc relay structure

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US (1) US3742405A (tr)
AU (1) AU472749B2 (tr)
CA (1) CA953758A (tr)
DE (1) DE2310975A1 (tr)
FR (1) FR2175028B1 (tr)
GB (1) GB1418174A (tr)
NL (1) NL7303158A (tr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4064470A (en) * 1975-06-20 1977-12-20 Trw Inc. Obturator structure for silent automotive relay
US4456896A (en) * 1982-12-30 1984-06-26 Trw Canada Limited Low cost relay
US4837950A (en) * 1988-05-27 1989-06-13 Vesper Herbert J End loading motor scraper
WO2000060625A1 (de) * 1999-04-07 2000-10-12 Tyco Electronics Logistics Ag Elektromagnetisches relais
EP1174896A2 (en) * 2000-07-18 2002-01-23 Fujitsu Takamisawa Component Limited Electromagnetic relay

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184564A (en) * 1963-04-30 1965-05-18 Gen Electric Shock proof relay
US3290629A (en) * 1964-05-25 1966-12-06 Bell Telephone Labor Inc Wire spring relay with improved means for determining contact force
US3544936A (en) * 1968-08-02 1970-12-01 Robertshaw Controls Co Symmetrical shaded pole electromagnet

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4064470A (en) * 1975-06-20 1977-12-20 Trw Inc. Obturator structure for silent automotive relay
US4456896A (en) * 1982-12-30 1984-06-26 Trw Canada Limited Low cost relay
US4837950A (en) * 1988-05-27 1989-06-13 Vesper Herbert J End loading motor scraper
WO2000060625A1 (de) * 1999-04-07 2000-10-12 Tyco Electronics Logistics Ag Elektromagnetisches relais
US6531939B1 (en) 1999-04-07 2003-03-11 Tyco Electronics Logistics Ag Electromagnetic relay
EP1174896A2 (en) * 2000-07-18 2002-01-23 Fujitsu Takamisawa Component Limited Electromagnetic relay
EP1174896A3 (en) * 2000-07-18 2003-08-27 Fujitsu Takamisawa Component Limited Electromagnetic relay
US6677840B2 (en) 2000-07-18 2004-01-13 Fujitsu Takamisawa Component Limited Electromagnetic relay

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Publication number Publication date
AU472749B2 (en) 1976-06-03
NL7303158A (tr) 1973-09-10
AU5294373A (en) 1974-09-12
CA953758A (en) 1974-08-27
FR2175028B1 (tr) 1977-02-04
GB1418174A (en) 1975-12-17
FR2175028A1 (tr) 1973-10-19
DE2310975A1 (de) 1973-09-13

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