US3755643A - Tilt actuated liquid metal switch having a negative break angle - Google Patents

Tilt actuated liquid metal switch having a negative break angle Download PDF

Info

Publication number
US3755643A
US3755643A US00031243A US3755643DA US3755643A US 3755643 A US3755643 A US 3755643A US 00031243 A US00031243 A US 00031243A US 3755643D A US3755643D A US 3755643DA US 3755643 A US3755643 A US 3755643A
Authority
US
United States
Prior art keywords
pool
envelope
switch
liquid metal
electrode
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
US00031243A
Other languages
English (en)
Inventor
C Blair
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.)
Honeywell Inc
Original Assignee
Honeywell 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
Application filed by Honeywell Inc filed Critical Honeywell Inc
Application granted granted Critical
Publication of US3755643A publication Critical patent/US3755643A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H29/00—Switches having at least one liquid contact
    • H01H29/20—Switches having at least one liquid contact operated by tilting contact-liquid container
    • H01H29/22—Switches having at least one liquid contact operated by tilting contact-liquid container wherein contact is made and broken between liquid and solid

Definitions

  • ABSTRACT A tilt actuated liquid metal switch of the liquid metal to electrode type including a depressor arranged to be in engagement with the pool of liquid metal which is located on a surface of the switch normally maintained in a substantially horizontal position so as to interact with the surface tension of the pool and thereby provide a force in the deactuating mode of the switch such that it is adequate to overcome the other inherent forces to cause disengagement of the pool from the electrode prior to the horizontal position being attained.
  • the present invention is directed to a tilt actuated liquid metal switch of the liquid metal to electrode type wherein a pool of liquid metal is associated with a surface of the switch envelope normally maintained in a substantially horizontal position and wherein the elements are so arranged that in the deactuating mode the pOOl moves away from the switching electrode prior to the surface attaining a horizontal position.
  • tilting of the switch envelope from a normal substantially horizontal position causes movement of the pool of liquid metal toward and into engagement with the switching electrode.
  • Reverse tilting causes reverse movement of the pool and disengagement from the electrode.
  • the amount of tilting required between switch closure and switch opening is of course known as the differential of the switch.
  • the differential of the application can be taken to be the same as the differential of the switch per se.
  • the differential of the application is greater than the differential of the switch per se due to the occurrence of an uncontrollable excess movement of the pool of liquid metal caused by the utilization of resilient driving means.
  • my invention is directed to a tilt actuated mercury switch of the mercury to electrode type including an elongated tubular glass envelope having a switching electrode and a pool depressor supported thereby with a pool of mercury disposed therein.
  • the depressor and the pool are arranged so that with the switch in a normally substantially horizontal position interaction of the pool and the depressor sets up a restoring force tending to move the pool away from the electrode.
  • the restoring force and the adhesional force between the pool of mercury and the interior surface of the envelope is overcome by gravitational force with the consequent movement of the pool into engagement with the electrode.
  • FIG. 1 is a top view of a liquid metal switch incorporating the invention
  • FIG. 2 is a side view of the switch of FIG. 1;
  • FIG. 3 is a view of the switch showing the various forces of the system
  • FIGS. 4 and 5 show two conditions of a liquid metal switch of the prior art in a thermostat application.
  • FIGS. 6 and 7 show two conditions of the liquid metal switch incorporating the invention hereof in the thermostat of FIGS. 4 and 5.
  • the switch includes a cylindrical envelope 12 which may be formed of potash soda lead glass.
  • a switching electrode 14 having a cylindrical extremity and a pool depressor 16 having a spherical extremity are supported by the envelope 12 in conventional fashion.
  • the electrode 14 but for the cylindrical extremity and the depressor 16 which also functions as an electrode may be fabricated from a nickel-iron alloy.
  • the cylindrical extremity of the electrode 14 may be fabricated from molybdenum.
  • a pool of liquid metal 18 which may be mercury is disposed within the envelope 12 for association with the electrode 14 and the depressor 16.
  • the spherical extremity of the depressor 16 engages the pool 18, and due to the interaction between the depressor and the surface tension of the pool, a surface restoring force tending to cause the pool to return to its free form shape results tending to remove the pool to an extremity of the envelope 12 away from the electrode 14.
  • This force is hereinafter identified as the restoring force".
  • Other forces in the system are the adhesional force between the engaging surfaces of the envelope l2 and the pool 18 which inhibits movement of the pool in either direction and, of course, gravitational force.
  • the forces just referred to are shown diagrammatically in FIG. 3.
  • the restoring force R is shown associated with the depressor l6 and the pool 18.
  • the effective gravitational force G is shown associated with the pool 18 as is the true gravitational force G.
  • the adhesional forces A which inhibits movement of the pool 18 in the actuating mode of the switch 10 and A which inhibits movement of the pool in the deactuating mode of the switch are shown associated with the engaging surfaces of the pool and of the envelope l2.
  • the switch 10 is shown in an exaggerated actuating mode where the adhesional force A comes into play and the adhesional force A is of no effect. Upon reverse tilting of the switch 10 taking place, adhesional force A,, comes into play and A is of no effect.
  • the pool 18 Upon reverse tilting of the switch 10, the pool 18 is under the influence of the forces G A and R. Because of the arrangement of the elements of the switch 10, the pool 18 begins moving and ultimately becomes disengaged from the cylindrical extremity of the electrode 14 prior to the horizontal position of the switch being attained. This is because at this point the restoring force R exceeds the summation of the effective gravitational force G and adhesional force A This results in the switch 10 having a negative break angle.
  • I utilized an envelope formed of Coming 0012 glass having an inside diameter of 0.290 inches with a switching electrode less the cylindrical extremity and a depressor comprised of 52 nickel-iron glass sealing alloy.
  • the cylindrical extremity of the electrode was formed of molybdenum to insure against wetting by the pool of mercury which weighed 2.9 grams.
  • the interior surface of the envelope was etched as taught by the Hyzer et al -U.S. Pat. No. 3,174,885.
  • the electrode and the depressor were disposed on the center line of the envelope as viewed in FIG. 2.
  • the spherical portion of the depressor was of 0.093 inches diameter and, as viewed in FIG. 1, offset from the center line by 0.005 inches.
  • the switching electrode was so placed that at the point of disengagement of the pool therefrom in the deactuating mode, the center of gravity of the pool was to the far side of the spherical extremity of the depressor thereby insuring that the restoring force acted in a manner assisting switching opening.
  • a spiral bimetal 20 appropriately supports a mercury'switch 22 having a pool of mercury 24 for association with a pair of electrodes 26 and 28.
  • the bimetal 20 must introduce sufficient force to move the switch first back to the horizontal position and then introduce further force to move the switch to cause switch closure. Because of the introduction of the mass shift of the pool 24, the differential of the arrangement including the bimetal 20 and the switch 22 is exaggerated and is greater than that of the switch per se.
  • FIGS. 6 and 7 a spiral bimetal 20 like that of FIGS. 4 and 5 supports a mercury switch 10 of the type described in regard to FIGS. 1-3.
  • the switch 10 With the switch 10 in the actuating mode of FIG. 6 and asking for heat, ultimately the temperature of the space being monitored rises causing the bimetal 20 to contract resulting in the switch being moved in a clockwise direction. As this movement continues, ultimately the restoring force exceeds the summation of the effective gravitational force and the adhesional force whereupon the pool 18 disengages from the electrode 14. The disengagement takes place prior to the switch attaining a horizontal position as is shown in FIG. 7.
  • a tilt actuated liquid metal switch comprising: an envelope having an interior surface normally maintained in a substantially horizontal position; a switching electrode supported by and extending into said envelope; a pool of liquid metal disposed within said envelope and engaging said interior surface; and a pool depressor provided within said envelope; said depressor including a portion located, with said envelope in the horizontal position.

Landscapes

  • Thermally Actuated Switches (AREA)
US00031243A 1970-04-23 1970-04-23 Tilt actuated liquid metal switch having a negative break angle Expired - Lifetime US3755643A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3124370A 1970-04-23 1970-04-23

Publications (1)

Publication Number Publication Date
US3755643A true US3755643A (en) 1973-08-28

Family

ID=21858370

Family Applications (1)

Application Number Title Priority Date Filing Date
US00031243A Expired - Lifetime US3755643A (en) 1970-04-23 1970-04-23 Tilt actuated liquid metal switch having a negative break angle

Country Status (4)

Country Link
US (1) US3755643A (zh)
JP (2) JPS464223A (zh)
CA (1) CA925551A (zh)
GB (1) GB1290991A (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993882A (en) * 1975-10-07 1976-11-23 The Gordos Corporation Micro-miniature mercury tilt-type inertia switch
US4201900A (en) * 1979-02-26 1980-05-06 Gordos Corporation Snap action tilt actuated mercury switch

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5938085U (ja) * 1982-09-02 1984-03-10 セーラー万年筆株式会社 両頭マ−キングペン
US4606702A (en) * 1985-01-10 1986-08-19 Huber Reversible Fan, Inc. Reversible fan with cylindrical resilient rubber spring

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232626A (en) * 1937-10-07 1941-02-18 Minneapolis Honeyweil Regulato Electric switch
US2830160A (en) * 1953-07-17 1958-04-08 Engel & Gibbs Ltd Control switches
US3198919A (en) * 1962-08-01 1965-08-03 Bendix Corp Mercury switch

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232626A (en) * 1937-10-07 1941-02-18 Minneapolis Honeyweil Regulato Electric switch
US2830160A (en) * 1953-07-17 1958-04-08 Engel & Gibbs Ltd Control switches
US3198919A (en) * 1962-08-01 1965-08-03 Bendix Corp Mercury switch

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993882A (en) * 1975-10-07 1976-11-23 The Gordos Corporation Micro-miniature mercury tilt-type inertia switch
US4201900A (en) * 1979-02-26 1980-05-06 Gordos Corporation Snap action tilt actuated mercury switch

Also Published As

Publication number Publication date
CA925551A (en) 1973-05-01
GB1290991A (zh) 1972-09-27
JPS464223A (zh) 1971-11-11
JPS5334317B1 (zh) 1978-09-20

Similar Documents

Publication Publication Date Title
US4053859A (en) Temperature sensitive switch
US2230770A (en) Circuit controller
US2798130A (en) Electric switch devices
US2288517A (en) Thermostatic switch
US3755643A (en) Tilt actuated liquid metal switch having a negative break angle
US4339740A (en) Thermally responsive switches
US3609270A (en) Electric reversing switch
US3707694A (en) Thermally sensitive circuit control apparatus
US2313341A (en) Snap action switch
US1976843A (en) Electrical switch
US3496511A (en) Thermostatic switch for small electrical appliances
US3735069A (en) Snap-action electric switch
US3691331A (en) Switch mechanism with s-shaped snap acting spring member
US2113227A (en) Thermostatic control
US3735080A (en) Snap-action electric switch
US2325785A (en) Enclosed mercury switch
US3213228A (en) Snap-acting mechanisms
US3043937A (en) Electrical control means
US2435716A (en) Control structure
US3305650A (en) Manually operable switches such as alternating current switches suitable for domestic installations
US2296374A (en) Switch
US3187130A (en) Snap-acting electrical switch with contact wiping action
US3272942A (en) Control switch for an electrical heating appliance
US2819362A (en) Switches
US2078441A (en) Limit switch