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CA998134A - Defeat resistant burglar alarm contact - Google Patents

Defeat resistant burglar alarm contact

Info

Publication number
CA998134A
CA998134A CA152,658A CA152658A CA998134A CA 998134 A CA998134 A CA 998134A CA 152658 A CA152658 A CA 152658A CA 998134 A CA998134 A CA 998134A
Authority
CA
Canada
Prior art keywords
burglar alarm
alarm contact
defeat
resistant
defeat resistant
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
Application number
CA152,658A
Other versions
CA152658S (en
Inventor
Thomas J. Byrne
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.)
American District Telegraph Co
Original Assignee
American District Telegraph 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 American District Telegraph Co filed Critical American District Telegraph Co
Application granted granted Critical
Publication of CA998134A publication Critical patent/CA998134A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H36/00—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding
    • H01H36/0006—Permanent magnet actuating reed switches
    • H01H36/0046—Limit switches, also fail-safe operation or anti-tamper considerations
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/02—Mechanical actuation
    • G08B13/08—Mechanical actuation by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
CA152,658A 1972-03-08 1972-09-27 Defeat resistant burglar alarm contact Expired CA998134A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23287172A 1972-03-08 1972-03-08

Publications (1)

Publication Number Publication Date
CA998134A true CA998134A (en) 1976-10-05

Family

ID=22874940

Family Applications (1)

Application Number Title Priority Date Filing Date
CA152,658A Expired CA998134A (en) 1972-03-08 1972-09-27 Defeat resistant burglar alarm contact

Country Status (3)

Country Link
US (1) US3771153A (en)
CA (1) CA998134A (en)
GB (1) GB1427565A (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3896427A (en) * 1974-06-27 1975-07-22 James P Campman Magnetically operated alarm
US4544903A (en) * 1983-11-17 1985-10-01 Pittway Corporation Electrical connector system
US4593491A (en) * 1984-01-31 1986-06-10 The United States Of America As Represented By The United States Department Of Energy Alarm sensor apparatus for closures
DE3409649C1 (en) * 1984-03-16 1985-11-07 Heinrich 3550 Marburg Sälzer Device for displaying the movement and / or position of a shut-off device
CN1232995C (en) * 2001-10-24 2005-12-21 李文丰 Enclosed electrical switch assembly
US7355515B2 (en) * 2005-09-23 2008-04-08 Honeywell International, Inc. Magnetic security device for securing doors
GB2450890B (en) * 2007-07-10 2011-12-14 Elmdene Internat Ltd Magnetic contact
GB2453591B (en) * 2007-10-12 2012-08-29 Elmdene Internat Ltd Magnetic contact
CN103903407B (en) * 2014-04-10 2016-06-22 宁波宇宏电气有限公司 Private network warning system for inspection well cover breakage, quilt

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2877361A (en) * 1957-04-12 1959-03-10 Holmes Electric Protective Com Burglar alarm system
US2912540A (en) * 1958-02-13 1959-11-10 American District Telegraph Co Defeat resistant burglar alarm contact
US3161742A (en) * 1961-08-24 1964-12-15 Specialties Dev Corp Magnetic intruder and fire deterctor
US3444493A (en) * 1966-08-29 1969-05-13 Ca Atomic Energy Ltd Magnetically operated reed switch assembly
CH473467A (en) * 1967-04-27 1969-05-31 Balanciers Reunies Sa Device for controlling at least one contact by magnetic means
US3544934A (en) * 1969-05-08 1970-12-01 American Mach & Foundry Proximity switch-type control means

Also Published As

Publication number Publication date
US3771153A (en) 1973-11-06
GB1427565A (en) 1976-03-10

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