US3729608A - Electrical switch having pivoted arm contact - Google Patents

Electrical switch having pivoted arm contact Download PDF

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Publication number
US3729608A
US3729608A US00180679A US3729608DA US3729608A US 3729608 A US3729608 A US 3729608A US 00180679 A US00180679 A US 00180679A US 3729608D A US3729608D A US 3729608DA US 3729608 A US3729608 A US 3729608A
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US
United States
Prior art keywords
contact
arm
contacts
switch
support member
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
US00180679A
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English (en)
Inventor
D Wiktor
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.)
Automatic Switch Co
Original Assignee
Automatic Switch 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 Automatic Switch Co filed Critical Automatic Switch Co
Application granted granted Critical
Publication of US3729608A publication Critical patent/US3729608A/en
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
    • H01H1/00—Contacts
    • H01H1/50—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
    • H01H1/54—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position by magnetic force
    • 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
    • H01H1/16—Contacts characterised by the manner in which co-operating contacts engage by abutting by rolling; by wrapping; Roller or ball contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
    • H01H9/38—Auxiliary contacts on to which the arc is transferred from the main contacts
    • H01H9/383—Arcing contact pivots relative to the movable contact assembly

Definitions

  • a switch having relatively movable contacts one of the contacts including a support member and an arm pivoted to the support member and engageable with the other contact.
  • the other contact is preferably a roller rotatable about an axis extending across the path of movement between the contacts, the roller being engaged by the pivoted arm when the switch closes.
  • a spring urges the arm toward the roller.
  • the arm and the support member form a looped path for electric current so that magnetic force created by the flow of current urges the arm toward the roller.
  • the relatively movable contacts may be arcing contacts of a switch having main relatively movable contacts.
  • This invention relates to electrical switches, and more particularly such a switch adapted to close, when, at the instant of closure, a high current flows in the circuit being completed by the switch.
  • Certain types of switching devices such as safety switches, contactors, circuit breakers, and interrupters, must be designed to close not only when normal current flow is present, but also on occasion when an abnormally high current is flowing, such as happens when the circuit is heavily overloaded, or when a fault current, such as a high in-rush current or short circuit current, is present.
  • an abnormally high current such as happens when the circuit is heavily overloaded, or when a fault current, such as a high in-rush current or short circuit current, is present.
  • the magnetic repulsive force tending to separate the contacts as they close is very large, and hence the mechanism associated with the switch must be made powerful enough to overcome the repulsive force and insure that the switch closes and remains closed.
  • Switching devices of the type mentioned above most commonly employ butt-type contacts which are especially susceptible to the repulsive force mentioned above, and which furthermore have a tendency to bounce and separate when they make contact. Therefore, the switch closing mechanism must be designed to overcome both this bounce and the highest repulsive force the switch is likely to encounter.
  • Some switches employ knife-type contacts in which a blade moves between two contact fingers spring biased toward each other so to tightly squeeze the blade between them. Knife-type contacts, although they bounce less on closing, do present a frictional drag between the closing contacts which must be overcome by the closing mechanism of the switch.
  • switch closing mechanisms must be designed with a large amount of available energy even though all this energy may be needed only on occasion. This over design is not only costly, but it also introduces excessive wear on all associated parts of the switch, since the full available energy of the closing mechanism is used to close the switch each time it operates, whether or not an abnormally large repulsive force is present. It is difficult to reduce the portion of the closing mechanism energy needed to overcome the repulsive force since the force occurs inherently as a result of the current flowing through the switch.
  • FIG. 1 is a top plan view of an electrical switch according to the present invention
  • FIG. 2 is a vertical cross-sectional view taken along line 22 ofFIG. 1;
  • FIG. 3 is a fragmentary horizontal cross-sectional view taken along line 33 of FIG. 2; and v FIG. 4 is a fragmentary view, on an enlarged scale, of a portion of FIG. 2 showing the switch immediately after it opens.
  • the electrical switch chosen to illustrate the present invention is carried by a base 10 of insulation material. Mounted on the upper face of base 10, by bolts 11, are a bus bar 12 and a post 13, the latter being formed of two appropriately bent metal strips. Secured to the upper end of post 13 is a stationary main contact 14. Another bus bar 15 is secured beneath base 10 by bolt 16. When the switch is closed, it electrically connects bus bars 12 and 15, and when the switch is open it disconnects these two bus bars.
  • a frame 20 formed of a single bent piece of metal.
  • the central portion of frame 20 lies against post 13, and a wall 21 extends upwardly from each side of the central portion.
  • the metal is bent to define a top 22.
  • the edge 23 of each wall 21 extends upwardly and outwardly from the switch.
  • a pin 24 carrying a rotatable metal roller 25.
  • Roller 25 serves as the stationary arcing contact of the switch.
  • an insulation block 32 which carries a metal bar 33. Fixed to bar 33 is the movable main contact 34 of the switch. Bar 33 is resiliently mounted on block 32, and for this purpose a bolt 35 extends upwardly through block 32 and through an elongated opening 36 in bar 33. Above bar 33, a compression spring 37 surrounds bolt 35 and seats against a pair of washers 38. Spring 37 constantly urges bar 33 downwardly, and thereby provides resilient contact pressure between main contacts 34 and 14.
  • Another screw 39 extends through an opening in bar 33 and into block 32. The lower end of screw 39 fits loosely in block 32 so as to permit some pivotal movement of bar 33 in a vertical plane.
  • Screw 39 serves to secure a metal eyelet 42 to bar 33, and a similar eyelet 43 is secured to bus bar 15 by bolt 16.
  • a flexible electrical connector 44 connects eyelets 42 and 43.
  • movable main contact 34 is always electrically connected to bus bar 15 through bar 33, eyelet 42, connector 44, eyelet 43, and bolt 16.
  • plates 29 carry a second insulation block 45 carrying a metal bar 46 identical to bar 33.
  • bar 46 is mounted in the same way as bar 33, and carries all the same components carried by bar 33. In addition, it cooperates with a stationary contact structure (not shown) identical to that described above.
  • a pair of eyelets 47 joined by a flexible electrical connector 48 electrically connect bar 46 to bus bar 15.
  • an L-shaped support member 52 Secured to the upper face of bar 33, by screws 51, is an L-shaped support member 52 having a channelshaped cross-section.
  • the upper end of upstanding leg 53 of support member 52 is shaped to define a pair of cars 54 between which a pivot pin 55 extends.
  • Pivotally mounted on pin 55 is an arm 56 carrying a movable arcing contact 57 at its lower end.
  • Arcing contact 57 is adapted to engage roller 25. Since movable arcing contact 57 moves in a vertical plane, as illustrated in FIG. 2, into and out of engagement with roller 25, the axis of rotation of roller 25 is horizontal and across the path of movement of contact 57.
  • roller 25 rotates thereby greatly diminishing frictional drag between the arcing contacts 57 and 25. Furthermore, due to rotation of roller 25, arcing contact 57 strikes different points on the. surface of the roller, and as a result the useful life of roller contact 25 is greatly increased.
  • arm 56 can swing toward and away from contact roller 25, and in the present example this is accomplished by arranging pivot pin 55 parallel to pin 24 which carriers roller 55.
  • a compression spring 60 constantly urges arm 56 in a counterclockwise direction, as viewed in FIGS. 2 and 4, so that movable arcing contact 57 is constantly urged toward stationary arcing contact 25.
  • Spring 60 is located within an insulated cup 61 mounted in support member 52.
  • An abutment 62 integral with arm 56 limits the counterclockwise movement of arm 56 by abutting the central web of support member 52, as shown in FIG. 4.
  • arm 56 and roller 25 have been described in the present example in connection with arcing contacts, this arrangement can be used with any switch contacts, including the main contacts. Furthermore, while in the present illustration arm 56 forms part of a movable contact and roller 25 the stationary contact, obviously this arrangement can be reversed. Although a single phase switch is illustrated in the drawings, it is to be understood that block 32 may carry additional poles when required. Each such pole is identical to the one illustrated.
  • An electrical switch including first and second relatively movable contacts, said first contact including a support member movable with respect to said second contact, an arm pivotally mounted on said support member and engageable with said second contact, aligned holes in said support and arm, and a pin arranged in said holes, said pin defining a pivot axis fixed with respect to each of said support and arm, whereby the arm is pivotally connected to the support member,
  • the pivot axis being so arranged that as said arm swings about said axis it moves in a direction toward and away from said second contact.
  • An electrical switch as defined in claini 1 including resilient means urging said arm about its pivot axis toward said second contact.
  • An electrical switch as defined in claim 6 including abutment means for limiting the movement of said arm under the influence of said spring.
  • the switch includes relatively movable main contacts, said support member being fixed to one of said main contacts and said second contact being fixed to the other of said main contacts.
  • An electrical switch as defined in claim 1 including an electrically conductive element alongside said second contact, an edge of said element diverging from said arm when said switch is closed and extending beyond said second Contact in the direction of divergence, whereby an are drawn between said contacts when the switch opens will jump from said second contact to said edge and lengthen as said switch continues to open.
  • An electrical switch including first and second relatively movable contacts, said first contact including a support member movable with respect to said second contact, said second contact including a roller rotatable about an axis extending across the path of movement between said contacts, and an arm pivotally mounted on said support member and engageable with said second contact, the pivot axis of said arm being so arranged that as said arm swings about said axis it moves in a direction toward and away from said second Contact.
  • An electrical switch including first and second relatively movable contacts, said first contact including a support member movable with respect to said second contact, and an arm pivotally mounted on said support member and engageable with said second contact, the pivot axis of said arm being so arranged that as said arm swings about said axis it moves in a direction toward and away from said second contact, and an electrically conductive element alongside said second contact, an edge of said element diverging from said arm when said switch is closed and extending beyond said second contact in the direction of divergence, whereby an are drawn between said contacts when the switch opens will jump from said second contact to saidedge and lengthenas said switch continues to open.

Landscapes

  • Arc-Extinguishing Devices That Are Switches (AREA)
  • Breakers (AREA)
  • Switch Cases, Indication, And Locking (AREA)
US00180679A 1971-09-15 1971-09-15 Electrical switch having pivoted arm contact Expired - Lifetime US3729608A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18067971A 1971-09-15 1971-09-15

Publications (1)

Publication Number Publication Date
US3729608A true US3729608A (en) 1973-04-24

Family

ID=22661334

Family Applications (1)

Application Number Title Priority Date Filing Date
US00180679A Expired - Lifetime US3729608A (en) 1971-09-15 1971-09-15 Electrical switch having pivoted arm contact

Country Status (7)

Country Link
US (1) US3729608A (cg-RX-API-DMAC7.html)
JP (1) JPS4837661A (cg-RX-API-DMAC7.html)
CA (1) CA965465A (cg-RX-API-DMAC7.html)
DE (1) DE2237771A1 (cg-RX-API-DMAC7.html)
FR (1) FR2152960B1 (cg-RX-API-DMAC7.html)
GB (1) GB1359072A (cg-RX-API-DMAC7.html)
NL (1) NL7211436A (cg-RX-API-DMAC7.html)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050227823A1 (en) * 2004-04-02 2005-10-13 Hsin Lung Accessories Co., Ltd. Stationary bike

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5614334Y2 (cg-RX-API-DMAC7.html) * 1975-07-25 1981-04-03
KR20140045406A (ko) * 2011-07-11 2014-04-16 교에이샤 케미칼 주식회사 띠 형상 건식 신선용 윤활재 및 그 제조방법

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2000442A (en) * 1934-05-15 1935-05-07 Ite Circuit Breaker Ltd Electric circuit interrupter
US2688716A (en) * 1951-09-18 1954-09-07 Henry B Eging Electric control center
US3158721A (en) * 1962-06-11 1964-11-24 Mc Graw Edison Co Main and auxiliary contacts wherein main relatively stationary contact is pivotally mounted to move in opposite direction to switch arm
US3459914A (en) * 1967-09-27 1969-08-05 Peritus Enkoping Ab Contacts for the poles of electrical switchgear

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2000442A (en) * 1934-05-15 1935-05-07 Ite Circuit Breaker Ltd Electric circuit interrupter
US2688716A (en) * 1951-09-18 1954-09-07 Henry B Eging Electric control center
US3158721A (en) * 1962-06-11 1964-11-24 Mc Graw Edison Co Main and auxiliary contacts wherein main relatively stationary contact is pivotally mounted to move in opposite direction to switch arm
US3459914A (en) * 1967-09-27 1969-08-05 Peritus Enkoping Ab Contacts for the poles of electrical switchgear

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050227823A1 (en) * 2004-04-02 2005-10-13 Hsin Lung Accessories Co., Ltd. Stationary bike

Also Published As

Publication number Publication date
NL7211436A (cg-RX-API-DMAC7.html) 1973-03-19
JPS4837661A (cg-RX-API-DMAC7.html) 1973-06-02
FR2152960B1 (cg-RX-API-DMAC7.html) 1977-12-30
DE2237771A1 (de) 1973-03-22
CA965465A (en) 1975-04-01
GB1359072A (en) 1974-07-10
FR2152960A1 (cg-RX-API-DMAC7.html) 1973-04-27

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