US3644693A - Nonsticking relay contacts - Google Patents
Nonsticking relay contacts Download PDFInfo
- Publication number
- US3644693A US3644693A US880128A US3644693DA US3644693A US 3644693 A US3644693 A US 3644693A US 880128 A US880128 A US 880128A US 3644693D A US3644693D A US 3644693DA US 3644693 A US3644693 A US 3644693A
- Authority
- US
- United States
- Prior art keywords
- mercury
- wettable
- contact
- barrier
- nonwettable
- 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
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H51/00—Electromagnetic relays
- H01H51/28—Relays having both armature and contacts within a sealed casing outside which the operating coil is located, e.g. contact carried by a magnetic leaf spring or reed
- H01H51/287—Details of the shape of the contact springs
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/0201—Materials for reed contacts
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/06—Contacts characterised by the shape or structure of the contact-making surface, e.g. grooved
- H01H1/08—Contacts characterised by the shape or structure of the contact-making surface, e.g. grooved wetted with mercury
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H51/00—Electromagnetic relays
- H01H51/28—Relays having both armature and contacts within a sealed casing outside which the operating coil is located, e.g. contact carried by a magnetic leaf spring or reed
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H51/00—Electromagnetic relays
- H01H51/28—Relays having both armature and contacts within a sealed casing outside which the operating coil is located, e.g. contact carried by a magnetic leaf spring or reed
- H01H51/288—Freely suspended contacts
Definitions
- ABSTRACT v A mercury relay having nonsticking mercury wettabie surfaces, one of the surfaces carrying a button of mercury wettabie material surrounded by a rim of nonmercury wettable material, preferably tantalum, which extends beyond the button and forms a physical barrier against physical impact between the mercury wettabie surfaces.
- HG ⁇ VETT BLE 151 G 1 CONTACT ll comma #1 ⁇ VETLQBE B '2 USER of NON- ⁇ VETTABLE CONTACT '2 m METAL or OX ⁇ DE.
- a relay contact operating in mercury which has a mercury wettable surface which is prevented from contacting an opposing contact during operation of the relay by interposing a mercury nonwettable barrier which surrounds the wettable surface
- FIG. 1 is a view in side elevation of two contacts according to the invention, at a first stage of their fabrication
- FIG. 2 is a view in side elevation of the contacts of FIG. 1, after a second step has been completed;
- FIG. 3 is a view in side elevation of contacts according to the invention, in completed state.
- FIG. 4 is a view in side elevation of the contacts of FIG. 3, but including a globule of mercury.
- a flat has been ground or otherwise removed from element 12, sufficiently to expose a flat surface 14 of element 12.
- a depression 15 is formed in flat surface 14, which falls deeper than the remaining ground edge 16 of the mercury nonwettable coating 13.
- the depression 15 may be formed by etching, for example with hot mercury, which attacks the wettable area 14, but not the nonwettable area 16.
- Contact materials must be selected so that they are easily Hg wettable, are of proper magnetic character, and are relatively insoluble in Hg and in each other. Suitable contact materials include Copper, Nickel, Platinum and various alloys of these.
- both contacts may be identical, if desired, which can increase the spacing between mercury wettable surfaces existing on physical impact of the switch contacts.
- tantalum and niobium are superior interposer materials in that they do not become wettable by impact against mercury wettable metal and do not alloy with the latter, to an extent far surpassing any other materials tested.
- Mercury relay contacts comprising a first contact having at least a first mercury wettable surface
- said second contact including a mercury wettable second electrical contact surface
- a mercury nonwettable barrier element surrounding said electrical contact surface and having a location and shape which prevents physical contact of said first and second surfaces when said first and second contacts impact but which assures sufficient proximity of said areas to assure completion of an electrical circuit therebetween in the present of a globule of liquid mercury on said electrical contact surface.
- a mercury contact comprising a supporting element
- buttons of mercury wettable material extending from said supporting element, said button of mercury wettable material having a face and having a peripheral surface,
- a layer of mercury nonwettable material secured about said peripheral surface and extending beyond said face to form a physical barrier against physical impact against said face.
- a mercury switch element including a contact carrying element
- said element being mercury nonwettable and said contact being of Hg wettable material
- a barrier of mercury nonwettable material surrounding said wettable material and extending beyond the surface thereof for about 0.001 inch, whereby a globule of Hg may attach to said wettable material and be bounded by said barrier of mercury nonwettable material.
- a nonsticking contact for a mercury switch comprising a support,
- a barrier of mercury nonwettable material extending from said surface to a still greater extent, said still greater extent being about 0.001 inch.
- a nonsticking contact for a mercury switch comprising a mercury wettable surface
- a nonmercury wettable barrier layer bounding said surface and extending beyond said surface about 0.001 inch.
- a nonsticking contact for a mercury switch comprising a mercury wettable circuit completing surface
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Contacts (AREA)
- Switches That Are Operated By Magnetic Or Electric Fields (AREA)
Abstract
A mercury relay having nonsticking mercury wettable surfaces, one of the surfaces carrying a button of mercury wettable material surrounded by a rim of nonmercury wettable material, preferably tantalum, which extends beyond the button and forms a physical barrier against physical impact between the mercury wettable surfaces.
Description
United States Patent Bitko [54] NONSTICKING RELAY CONTACTS [72] Inventor: Sheldon S. Bitko, Cherry Hill, NJ.
[73] Assignee: Fiith Dimension, Inc., Princeton, NJ.
[22] Filed: Nov. 26, 1969 [2]] App]. No.: 880,128
[52] US. Cl. ..200/166 C, 200/152 K [5i] int. Cl..... H0lh 1/08 [58] FieldofSeal'ch ..200/166 C, 152 K [56] References Cited UNITED STATES PATENTS 3,155,804 11/1964 Gewirtz ..200/166 C 115] 3,644,693 1451 Feb. 22, 1972 Courtney-Pratt ..200/166 C Janninck ..200/166 C UX Primary Examinerl-l. 0. Jones Altorneyl-iurvitz & Rose [57] ABSTRACT v A mercury relay having nonsticking mercury wettabie surfaces, one of the surfaces carrying a button of mercury wettabie material surrounded by a rim of nonmercury wettable material, preferably tantalum, which extends beyond the button and forms a physical barrier against physical impact between the mercury wettabie surfaces.
8 Clai 4 i i 'iisqsss PATENTEDFEH22 m2 3.644.693
HG \VETT BLE 151 G 1 CONTACT ll comma # 1 \VETLQBE B '2 USER of NON-\VETTABLE CONTACT '2 m METAL or OX\DE.
I M II 6.3 rrrrrr I! 1 II I in [L3 as 15 L i 1 I INVENTDR SHELDON 5. BlTKD E M v ax,
ATTORNEYS NONSTICKING RELAY CONTACTS BACKGROUND OF THE INVENTION Whenever two mercury wet metallic elements are brought into metal-to-metal contact, separated only by a very thin layer of mercury, atoms of the solid metal diffuse through the mercury, and sticking occurs. Diffusion is accelerated at elevated temperatures at an exponential rate. It is an object of the present invention to provide a relay which completes its circuit through mercury via wettable surfaces while maintaining a spacing between the wet surfaces which is greater than that which permits appreciable diffusion of metal from one surface to the other, by interposing a nonwettable metallic spacer or interposer between the wettable surfaces.
SUMMARY OF THE INVENTION a relay contact operating in mercury which has a mercury wettable surface which is prevented from contacting an opposing contact during operation of the relay by interposing a mercury nonwettable barrier which surrounds the wettable surface,
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation of two contacts according to the invention, at a first stage of their fabrication;
FIG. 2 is a view in side elevation of the contacts of FIG. 1, after a second step has been completed;
FIG. 3 is a view in side elevation of contacts according to the invention, in completed state; and
FIG. 4 is a view in side elevation of the contacts of FIG. 3, but including a globule of mercury.
DESCRIPTION OF THE PREFERRED EMBODIMENT Assume that the present invention is applied to a mercury contact reed switch, a typical example of which is the switch disclosed in the US Pat. to Barlow No. 3,431,377, issued Mar. 4, 1969. One of the contacts 10, in FIG. I, is assumed mercury wettable, and the other contact arm 11, includes an Hg wettable element 12, which may be arcuate in form as viewed from contact 10, although the precise shape of element 12 does not go to the essence of the invention. The contact arm 11 and the element 12 are coated with a nonwettable metal or oxide coating 13.
In FIG. 2, a flat has been ground or otherwise removed from element 12, sufficiently to expose a flat surface 14 of element 12.
In FIG. 3, a depression 15 is formed in flat surface 14, which falls deeper than the remaining ground edge 16 of the mercury nonwettable coating 13. The depression 15 may be formed by etching, for example with hot mercury, which attacks the wettable area 14, but not the nonwettable area 16.
Surface tension will leave a globule of mercury 17 on the surface of the wettable metal, now identified as 120, but none will adhere to the nonwettable metal or oxide at 16 (FIG. 4), thus forming a circular globule of mercury which is constrained within fixed boundaries.
Now, when contact and contact arm 11 impact, one against the other, as occurs in normal operation of a relay, physical metal-to-metal contact will occur at a mercury nonwettable surface, but an electrical circuit will exist, primarily through the mercury via two opposed but separated mercury wettable surfaces. The mercury-wet metallic surfaces do not approach each other sufficiently, in contacts arranged according to the invention, to enable substantial diffusion of metal through the mercury, as would occur on physical metal-tometal contact between two wettable surfaces, where diffusion can occur either by direct contact, or through a layer of mercury which is only a few atoms thick. Experience shows that maintaining physical spacing between mercury wettable contacts at a value of about 0.001 inch or slightly less, is adequate to prevent sticky contacts, and further that operation is then bounce free.
Contact materials must be selected so that they are easily Hg wettable, are of proper magnetic character, and are relatively insoluble in Hg and in each other. Suitable contact materials include Copper, Nickel, Platinum and various alloys of these.
While the present invention relates directly to reed switches, the principles of the invention are applicable to any mercury switch, and particularly to a shuttle switch such as is illustrated in US. Pat. to Donath 3,144,533, issued Aug. 11, 1964.
It is also clear that both contacts may be identical, if desired, which can increase the spacing between mercury wettable surfaces existing on physical impact of the switch contacts.
It has been determined that tantalum and niobium are superior interposer materials in that they do not become wettable by impact against mercury wettable metal and do not alloy with the latter, to an extent far surpassing any other materials tested.
I claim:
1. Mercury relay contacts, comprising a first contact having at least a first mercury wettable surface,
a second contact, said second contact including a mercury wettable second electrical contact surface,
a mercury nonwettable barrier element surrounding said electrical contact surface and having a location and shape which prevents physical contact of said first and second surfaces when said first and second contacts impact but which assures sufficient proximity of said areas to assure completion of an electrical circuit therebetween in the present of a globule of liquid mercury on said electrical contact surface.
2. The combination according to claim I, wherein said electrical barrier element surrounds said second electrical contact surface.
3. A mercury contact, comprising a supporting element,
a button of mercury wettable material extending from said supporting element, said button of mercury wettable material having a face and having a peripheral surface,
a layer of mercury nonwettable material secured about said peripheral surface and extending beyond said face to form a physical barrier against physical impact against said face.
4. A mercury switch element, including a contact carrying element,
said element being mercury nonwettable and said contact being of Hg wettable material, and
a barrier of mercury nonwettable material surrounding said wettable material and extending beyond the surface thereof for about 0.001 inch, whereby a globule of Hg may attach to said wettable material and be bounded by said barrier of mercury nonwettable material.
5. A nonsticking contact for a mercury switch, comprising a support,
a mass of mercury wettable material secured to said support and having a surface displaced from said support to a first extent, and
a barrier of mercury nonwettable material extending from said surface to a still greater extent, said still greater extent being about 0.001 inch.
6. A nonsticking contact for a mercury switch, comprising a mercury wettable surface, and
a nonmercury wettable barrier layer bounding said surface and extending beyond said surface about 0.001 inch.
7. A nonsticking contact for a mercury switch, comprising a mercury wettable circuit completing surface, and
an adjacent nonmercury wettable barrier extending beyond said surface about 0.001 inch.
8. The combination according to claim 7, wherein said mercury wettable surface is cup-shaped.
' I i l l 1
Claims (8)
1. Mercury relay contacts, comprising a first contact having at least a first mercury wettable surface, a second contact, said second contact including a mercury wettable second electrical contact surface, a mercury nonwettable barrier element surrounding said electrical contact surface and having a location and shape which prevents physical contact of said first and second surfaces when said first and second contacts impact but which assures sufficient proximity of said areas to assure completion of an electrical circuit therebetween in the present of a globule of liquid mercury on said electrical contact surface.
2. The combination according to claim 1, wherein said electrical barrier element surrounds said second electrical contact surface.
3. A mercury contact, comprising a supporting element, a button of mercury wettable material extending from said supporting element, said button of mercury wettable material having a face and having a peripheral surface, a layer of mercury nonwettable material secured about said peripheral surface and extending beyond said face to form a physical barrier against physical impact against said face.
4. A mercury switch element, including a contact carrying element, said element being mercury nonwettable and said contact being of Hg wettable material, and a barrier of mercury nonwettable material surrounding said wettable material and extending beyond the surface thereof for about 0.001 inch, whereby a globule of Hg may attach to said wettable material and be bounded by said barrier of mercury nonwettable material.
5. A nonsticking contact for a mercury switch, comprising a support, a mass of mercury wettable material secured to said support and having a surface displaced from said support to a first extent, and a barrier of mercury nonwettable material extending from said surface to a still greater extent, said still greater extent being about 0.001 inch.
6. A nonsticking contact for a mercury switch, comprising a mercury wettable surface, and a nonmercury wettable barrier layer bounding said surface and extending beyond said surface about 0.001 inch.
7. A nonsticking contact for a mercury switch, comprising a mercury wettable circuit completing surface, and an adjacent nonmercury wettable barrier extending beyond said surface about 0.001 inch.
8. The combination according to claim 7, wherein said mercury wettable sUrface is cup-shaped.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US88012869A | 1969-11-26 | 1969-11-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3644693A true US3644693A (en) | 1972-02-22 |
Family
ID=25375568
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US880128A Expired - Lifetime US3644693A (en) | 1969-11-26 | 1969-11-26 | Nonsticking relay contacts |
Country Status (7)
Country | Link |
---|---|
US (1) | US3644693A (en) |
JP (1) | JPS4840934B1 (en) |
CA (1) | CA929997A (en) |
DE (1) | DE2058271A1 (en) |
FR (1) | FR2068655B1 (en) |
GB (1) | GB1326760A (en) |
NL (1) | NL7017265A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3876850A (en) * | 1972-07-04 | 1975-04-08 | Phillippe Paul Amberny | Liquid type modular electrical switch |
US4066859A (en) * | 1975-05-26 | 1978-01-03 | U.S. Philips Corporation | Mercury wettable contact assembly |
US4652710A (en) * | 1986-04-09 | 1987-03-24 | The United States Of America As Represented By The United States Department Of Energy | Mercury switch with non-wettable electrodes |
US4683355A (en) * | 1986-12-09 | 1987-07-28 | Fifth Dimension Inc. | Position insensitive shock sensor |
US5363669A (en) * | 1992-11-18 | 1994-11-15 | Whirlpool Corporation | Defrost cycle controller |
US20190152443A1 (en) * | 2016-06-02 | 2019-05-23 | Spark Co. Ltd. | Vehicle wiper blade |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2818466C2 (en) * | 1977-04-29 | 1986-09-18 | C.P. Clare International N.V., Tongeren | Mercury reed relays |
JPS60176912U (en) * | 1984-05-03 | 1985-11-25 | トヨタ自動車株式会社 | Defroster air direction adjustment device |
US4644854A (en) * | 1985-03-27 | 1987-02-24 | Bowles Fluidics Corporation | Air sweep defroster |
DE3528890A1 (en) * | 1985-08-12 | 1987-02-19 | Siemens Ag | Contact element |
-
1969
- 1969-11-26 US US880128A patent/US3644693A/en not_active Expired - Lifetime
-
1970
- 1970-11-09 CA CA097663A patent/CA929997A/en not_active Expired
- 1970-11-12 GB GB5396770A patent/GB1326760A/en not_active Expired
- 1970-11-20 JP JP45102039A patent/JPS4840934B1/ja active Pending
- 1970-11-23 FR FR707041915A patent/FR2068655B1/fr not_active Expired
- 1970-11-25 NL NL7017265A patent/NL7017265A/xx unknown
- 1970-11-26 DE DE19702058271 patent/DE2058271A1/en active Pending
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3876850A (en) * | 1972-07-04 | 1975-04-08 | Phillippe Paul Amberny | Liquid type modular electrical switch |
US4066859A (en) * | 1975-05-26 | 1978-01-03 | U.S. Philips Corporation | Mercury wettable contact assembly |
US4652710A (en) * | 1986-04-09 | 1987-03-24 | The United States Of America As Represented By The United States Department Of Energy | Mercury switch with non-wettable electrodes |
US4683355A (en) * | 1986-12-09 | 1987-07-28 | Fifth Dimension Inc. | Position insensitive shock sensor |
US5363669A (en) * | 1992-11-18 | 1994-11-15 | Whirlpool Corporation | Defrost cycle controller |
US5363667A (en) * | 1992-11-18 | 1994-11-15 | Whirlpool Corporation | Refrigerator control circuit with relay operation checking |
US5369962A (en) * | 1992-11-18 | 1994-12-06 | Whirlpool Corporation | Refrigeration system configuration |
US5373705A (en) * | 1992-11-18 | 1994-12-20 | Whirlpool Corporation | Defrost cycle controller |
US5394291A (en) * | 1992-11-18 | 1995-02-28 | Whirlpool Corporation | Relay energizing circuit |
US5454230A (en) * | 1992-11-18 | 1995-10-03 | Whirlpool Corporation | Refrigeration control circuit with self-test mode |
US5456087A (en) * | 1992-11-18 | 1995-10-10 | Whirlpool Corporation | Refrigeration system with failure mode |
US5469715A (en) * | 1992-11-18 | 1995-11-28 | Whirlpool Corporation | Defrost cycle controller |
US5533360A (en) * | 1992-11-18 | 1996-07-09 | Whirlpool Corporation | Refrigeration system configuration |
US20190152443A1 (en) * | 2016-06-02 | 2019-05-23 | Spark Co. Ltd. | Vehicle wiper blade |
Also Published As
Publication number | Publication date |
---|---|
GB1326760A (en) | 1973-08-15 |
CA929997A (en) | 1973-07-10 |
DE2058271A1 (en) | 1971-07-15 |
FR2068655B1 (en) | 1973-02-02 |
NL7017265A (en) | 1971-05-28 |
JPS4840934B1 (en) | 1973-12-04 |
FR2068655A1 (en) | 1971-08-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3644693A (en) | Nonsticking relay contacts | |
US5095297A (en) | Thin film fuse construction | |
ATE14169T1 (en) | ARC EXTINGUISHING DEVICE FOR ELECTRIC CURRENT LIMITING SWITCHES. | |
US3908109A (en) | Dome shaped switch member | |
GB1259567A (en) | ||
US2445406A (en) | Circuit maker and breaker | |
US2732459A (en) | pollard | |
US3268701A (en) | Clad electrical contacts | |
US3114811A (en) | Reduction of sticking of mercury-wetted contacts | |
JPS6032298B2 (en) | temperature switch | |
US2247493A (en) | Mercury contact relay | |
GB850558A (en) | Improvements in or relating to electrical contacts | |
GB1219204A (en) | Sealed mercury-wetted contact device | |
US2762889A (en) | Thermal switch | |
US3018354A (en) | Means for preventing contact sticking in mercury contact switches | |
US2535400A (en) | Multicontact dry reed relay | |
US3324432A (en) | Sealed contact makers including diaphragms for closing contacts | |
US3214558A (en) | Contact arrangement exhibiting reduced material migration | |
US3348174A (en) | Blade armature contact in sealed housing | |
US2203321A (en) | Switching device | |
US2836674A (en) | Rotary relay | |
US2916586A (en) | Thermal switches | |
US3569653A (en) | Electrical contact and contact assembly | |
GB1601718A (en) | Mercury-wetted reed contact unit | |
GB1519388A (en) | Electric switch |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: PNC BANK, NATIONAL ASSOCIATION, NEW JERSEY Free format text: SECURITY INTEREST;ASSIGNOR:FIFTH DIMENSION, INC.;REEL/FRAME:009103/0531 Effective date: 19911206 |
|
AS | Assignment |
Owner name: PNC BANK, N.A., NEW JERSEY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FIFTH DIMENSION, INC.;REEL/FRAME:010144/0181 Effective date: 19990712 |