US3018354A - Means for preventing contact sticking in mercury contact switches - Google Patents
Means for preventing contact sticking in mercury contact switches Download PDFInfo
- Publication number
- US3018354A US3018354A US848028A US84802859A US3018354A US 3018354 A US3018354 A US 3018354A US 848028 A US848028 A US 848028A US 84802859 A US84802859 A US 84802859A US 3018354 A US3018354 A US 3018354A
- Authority
- US
- United States
- Prior art keywords
- mercury
- contact
- tin
- copper
- switches
- 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
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Classifications
-
- 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
Definitions
- This invention relates to electric switches and particularly to such switches in which metallic material in liquid form is used as a medium through which circuit contina ty is effected.
- Switches of the kind under consideration are often called mercury switches because of the common use of this material as the liquid contact medium.
- a mercury switch may take several forms, there is disclosed for illustrative purposes one of the mercury contact type as in Patents 2,609,464 to J. T. L. Brown and C. E. Pollard, Jr. and"2,868,926 to C. E. Pollard, Jr.
- This object is attained in accordance with a feature of this invention by using a solution of mercury, copper and tin as the contact medium.
- the reed switch illustrated comprises an envelope or housing 10, which may be of glass.
- envelope or housing 10 which may be of glass.
- spaced pole-piece terminals 11 and 12 of magnetic material are sealed.
- the facing inner ends of the terminals 11 and 12 are provided with contacts 13 and 14, respectively, which may be of platinum or platinum and nickel.
- the opposite end 10b of the envelope 10 has a metal tube 20 extending through and sealed therein.
- a part of the tube within the envelope has a flared or cup-like portion 20a. Contained within this cup portion and designated 21 is a quantity of the mercury-copper-tin solution previously noted. There may be an excess of this solution surrounding the cup.
- a reed or swinger of magnetic material such as Permalloy, is secured to the cup a as at 15a and has a looped portion 15b within the cup.
- the reed 15 may atent O 3,018,354 Patented Jan. 23, 1962 ICC be advantageously coated with nickel to improve its mercury wettability.
- An energizing coil 22 shown schematically in the drawing, surrounds the envelope 10.
- the liquid contact medium may comprise the mercury, tin and copper in various proportions.
- suitable nonsticking contacts have been made with 6.0 milligrams of tin and 0.3 milligram of copper in 0.1 cubic centimeter of mercury.
- the lower limit of copper useful for the intended purpose is not clearly defined, although 0.25 milligram of tin and 0.3 milligram of copper in 0.1 cubic centimeter of mercury attained the desired result.
- the upper limit for copper appears to be 0.05 percent and that for tin about 0.5 percent by weight.
- the lower limit for tin appears to be about 0.01 percent by weight.
- the maximum amount of tin and of copper or less of either or both down to a minimum beyond which the desired effect is not achieved.
- the minimum of copper may be none at all provided sufficient tin is used.
- an agent for wetting the con tacts comprising a mercury-tin-copper solution.
- an agent for wetting the contacts comprising a mercury-tincopper solution.
- An electric switch having movable circuit controlling elemenrts housed in a sealed insulating envelope, and a pool of mercury-tin-copper solution in said envelope.
- An electric switch in which circuit continuity is maintained by way of contacts wetted by a liquid contact material comprising tin in an amount up to 0.5 percent by weight and copper in an amount up to 0.05 percent by weight dissolved in mercury.
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- Contacts (AREA)
- Manufacture Of Switches (AREA)
Description
Jan. 23, 1962 C. E. POLLARD, MEANS FOR PREVENTING CONTAC JR T STICKING IN MERCURY CONTACT SWITCHES Filed Oct. 22, 1959 //v l/ENTOR C. E. POL LARO, JR.
ATTORNEY United Stes This invention relates to electric switches and particularly to such switches in which metallic material in liquid form is used as a medium through which circuit contina ty is effected.
Switches of the kind under consideration are often called mercury switches because of the common use of this material as the liquid contact medium. Although a mercury switch may take several forms, there is disclosed for illustrative purposes one of the mercury contact type as in Patents 2,609,464 to J. T. L. Brown and C. E. Pollard, Jr. and"2,868,926 to C. E. Pollard, Jr.
It has been previously discovered, as set forth in Patent 2,732,459 to C. E. Pollard, Jr., that in switches having mercury as the contact medium, the contacts have a tendency to stick. One solution of the sticking problem is set forth in this last noted patent, namely, the use of a copper-mercury solution in place of mercury alone where all contacts are substantially platinum.
It is an object of this invention to further improve the structure and thus the operation of mercury type contact switches in which the wetted contacts tend to stick where one or more of the contacts are nickel or a similar metal.
This object is attained in accordance with a feature of this invention by using a solution of mercury, copper and tin as the contact medium.
The foregoing and other objects and features of this invention will appear more fully and clearly from the ensuing description of a switch structure illustrated in the appended drawing in which the single figure shows in partial section an electromagnetically operable sealed reed switch having as a contact medium a solution of mercury, copper and tin.
The reed switch illustrated comprises an envelope or housing 10, which may be of glass. In one end a of the envelope 10, spaced pole-piece terminals 11 and 12 of magnetic material are sealed. The facing inner ends of the terminals 11 and 12 are provided with contacts 13 and 14, respectively, which may be of platinum or platinum and nickel.
The opposite end 10b of the envelope 10 has a metal tube 20 extending through and sealed therein. A part of the tube within the envelope has a flared or cup-like portion 20a. Contained within this cup portion and designated 21 is a quantity of the mercury-copper-tin solution previously noted. There may be an excess of this solution surrounding the cup.
A reed or swinger of magnetic material, such as Permalloy, is secured to the cup a as at 15a and has a looped portion 15b within the cup. The reed 15 may atent O 3,018,354 Patented Jan. 23, 1962 ICC be advantageously coated with nickel to improve its mercury wettability.
An energizing coil 22, shown schematically in the drawing, surrounds the envelope 10.
The theory of operation of mercury contact switches is known to those skilled in the art and is, accordingly, not here discussed. For further information with regard to the particular type of switch chosen to illustrate this invention, reference is made to the previously noted Patents 2,609,464 and 2,868,926.
The liquid contact medium may comprise the mercury, tin and copper in various proportions. For example, suitable nonsticking contacts have been made with 6.0 milligrams of tin and 0.3 milligram of copper in 0.1 cubic centimeter of mercury. The lower limit of copper useful for the intended purpose is not clearly defined, although 0.25 milligram of tin and 0.3 milligram of copper in 0.1 cubic centimeter of mercury attained the desired result. The upper limit for copper appears to be 0.05 percent and that for tin about 0.5 percent by weight. The lower limit for tin appears to be about 0.01 percent by weight.
Thus, one may use the maximum amount of tin and of copper or less of either or both down to a minimum beyond which the desired effect is not achieved. In view of the much greater amount of tin than copper that may be dissolved in mercury and of its apparently greater effect on the contact operation, the minimum of copper may be none at all provided sufficient tin is used.
Although this invention has been disclosed with respect to a particular switch illustrative thereof, it is not confined to such structure but may be used advantageously in other liquid contact switches subject to contact sticking.
What is claimed is:
1. In an electric switch of the type employing engageable wetted contacts, an agent for wetting the con tacts comprising a mercury-tin-copper solution.
2. In an electric switch of the type employing engageable wetted contacts, at least one of which is nickel, an agent for wetting the contacts comprising a mercury-tincopper solution.
3. In an electric switch having engageable contacts housed in an insulating envelope, liquid mercury with tin and copper dissolved therein.
4. An electric switch having movable circuit controlling elemenrts housed in a sealed insulating envelope, and a pool of mercury-tin-copper solution in said envelope.
5. An electric switch in which circuit continuity is maintained by way of contacts wetted by a liquid contact material comprising tin in an amount up to 0.5 percent by weight and copper in an amount up to 0.05 percent by weight dissolved in mercury.
References Cited in the file of this patent UNITED STATES PATENTS 2,319,259 Peterson May 18, 1943 2,732,459 Pollard Jan. 24, 1956. 2,796,495 Keitel et a1. June 18, 1957,
Claims (1)
1. IN AN ELECTRIC SWITCH OF THE TYPE EMPLOYING ENGAGEABLE WETTED CONTACTS, AN AGENT FOR WETTING THE CONTACTS COMPRISING A MERCURY-TIN-COPPER SOLUTION.
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL126656D NL126656C (en) | 1959-10-22 | ||
NL255854D NL255854A (en) | 1959-10-22 | ||
US848028A US3018354A (en) | 1959-10-22 | 1959-10-22 | Means for preventing contact sticking in mercury contact switches |
DEW28451A DE1147647B (en) | 1959-10-22 | 1960-08-26 | Electrical switch with contacts wetted by a mercury solution to prevent contact sticking |
FR839791A FR1274696A (en) | 1959-10-22 | 1960-09-28 | Non-stick wet contact switch |
GB34136/60A GB929669A (en) | 1959-10-22 | 1960-10-05 | Improvements in or relating to electric switches |
BE596077A BE596077A (en) | 1959-10-22 | 1960-10-17 | Devices for preventing sticking in mercury contacts. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US848028A US3018354A (en) | 1959-10-22 | 1959-10-22 | Means for preventing contact sticking in mercury contact switches |
Publications (1)
Publication Number | Publication Date |
---|---|
US3018354A true US3018354A (en) | 1962-01-23 |
Family
ID=25302148
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US848028A Expired - Lifetime US3018354A (en) | 1959-10-22 | 1959-10-22 | Means for preventing contact sticking in mercury contact switches |
Country Status (6)
Country | Link |
---|---|
US (1) | US3018354A (en) |
BE (1) | BE596077A (en) |
DE (1) | DE1147647B (en) |
FR (1) | FR1274696A (en) |
GB (1) | GB929669A (en) |
NL (2) | NL126656C (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3114811A (en) * | 1961-11-16 | 1963-12-17 | Bell Telephone Labor Inc | Reduction of sticking of mercury-wetted contacts |
US3343110A (en) * | 1965-05-28 | 1967-09-19 | Int Standard Electric Corp | Adhesive relay |
US3356813A (en) * | 1965-06-02 | 1967-12-05 | Nippon Electric Co | Mercury sealed contact switch |
US3431377A (en) * | 1967-03-03 | 1969-03-04 | Bell Telephone Labor Inc | Mercury contact switch having an alloy contact |
US4311769A (en) * | 1979-02-21 | 1982-01-19 | Andreev Oleg M | Mercury contact |
US6979789B1 (en) | 2005-03-21 | 2005-12-27 | Agilent Technologies, Inc. | Switches having wettable surfaces comprising a material that does not form alloys with a switching fluid, and method of making same |
US11309140B2 (en) * | 2019-01-04 | 2022-04-19 | Littelfuse, Inc. | Contact switch coating |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2319259A (en) * | 1941-10-29 | 1943-05-18 | Wilson H A Co | Contact |
US2732459A (en) * | 1953-09-21 | 1956-01-24 | pollard | |
US2796495A (en) * | 1953-12-23 | 1957-06-18 | Baker & Co Inc | Electrical contact elements |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2547536A (en) * | 1951-04-03 | Formation of a surface easily |
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0
- NL NL255854D patent/NL255854A/xx unknown
- NL NL126656D patent/NL126656C/xx active
-
1959
- 1959-10-22 US US848028A patent/US3018354A/en not_active Expired - Lifetime
-
1960
- 1960-08-26 DE DEW28451A patent/DE1147647B/en active Pending
- 1960-09-28 FR FR839791A patent/FR1274696A/en not_active Expired
- 1960-10-05 GB GB34136/60A patent/GB929669A/en not_active Expired
- 1960-10-17 BE BE596077A patent/BE596077A/en unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2319259A (en) * | 1941-10-29 | 1943-05-18 | Wilson H A Co | Contact |
US2732459A (en) * | 1953-09-21 | 1956-01-24 | pollard | |
US2796495A (en) * | 1953-12-23 | 1957-06-18 | Baker & Co Inc | Electrical contact elements |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3114811A (en) * | 1961-11-16 | 1963-12-17 | Bell Telephone Labor Inc | Reduction of sticking of mercury-wetted contacts |
US3343110A (en) * | 1965-05-28 | 1967-09-19 | Int Standard Electric Corp | Adhesive relay |
US3356813A (en) * | 1965-06-02 | 1967-12-05 | Nippon Electric Co | Mercury sealed contact switch |
US3431377A (en) * | 1967-03-03 | 1969-03-04 | Bell Telephone Labor Inc | Mercury contact switch having an alloy contact |
US3491219A (en) * | 1967-03-03 | 1970-01-20 | Bell Telephone Labor Inc | Mercury switch having at least one contact preformed from an alloy containing nickel,copper and tin |
DE1690535B1 (en) * | 1967-03-03 | 1970-12-23 | Western Electric Co | Mercury switch |
US4311769A (en) * | 1979-02-21 | 1982-01-19 | Andreev Oleg M | Mercury contact |
US6979789B1 (en) | 2005-03-21 | 2005-12-27 | Agilent Technologies, Inc. | Switches having wettable surfaces comprising a material that does not form alloys with a switching fluid, and method of making same |
US11309140B2 (en) * | 2019-01-04 | 2022-04-19 | Littelfuse, Inc. | Contact switch coating |
US20220122784A1 (en) * | 2019-01-04 | 2022-04-21 | Littelfuse, Inc. | Contact switch coating |
Also Published As
Publication number | Publication date |
---|---|
NL255854A (en) | |
FR1274696A (en) | 1961-10-27 |
GB929669A (en) | 1963-06-26 |
DE1147647B (en) | 1963-04-25 |
NL126656C (en) | |
BE596077A (en) | 1961-02-15 |
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