US3374323A - Pressure responsive device for actuating an alarm - Google Patents
Pressure responsive device for actuating an alarm Download PDFInfo
- Publication number
- US3374323A US3374323A US540865A US54086566A US3374323A US 3374323 A US3374323 A US 3374323A US 540865 A US540865 A US 540865A US 54086566 A US54086566 A US 54086566A US 3374323 A US3374323 A US 3374323A
- Authority
- US
- United States
- Prior art keywords
- panels
- alarm
- cavity
- switch
- space
- 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
- 239000000463 material Substances 0.000 description 12
- 238000004891 communication Methods 0.000 description 7
- 239000004033 plastic Substances 0.000 description 7
- 229920003023 plastic Polymers 0.000 description 7
- 125000006850 spacer group Chemical group 0.000 description 7
- 230000002093 peripheral effect Effects 0.000 description 6
- 238000007789 sealing Methods 0.000 description 5
- 239000000853 adhesive Substances 0.000 description 4
- 230000001070 adhesive effect Effects 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 239000004677 Nylon Substances 0.000 description 3
- 229920001778 nylon Polymers 0.000 description 3
- 229920000515 polycarbonate Polymers 0.000 description 3
- 239000004800 polyvinyl chloride Substances 0.000 description 3
- 229920000915 polyvinyl chloride Polymers 0.000 description 3
- 229920003319 Araldite® Polymers 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- 239000004425 Makrolon Substances 0.000 description 2
- 239000004696 Poly ether ether ketone Substances 0.000 description 2
- 239000004809 Teflon Substances 0.000 description 2
- 229920006362 Teflon® Polymers 0.000 description 2
- JUPQTSLXMOCDHR-UHFFFAOYSA-N benzene-1,4-diol;bis(4-fluorophenyl)methanone Chemical compound OC1=CC=C(O)C=C1.C1=CC(F)=CC=C1C(=O)C1=CC=C(F)C=C1 JUPQTSLXMOCDHR-UHFFFAOYSA-N 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 229920002530 polyetherether ketone Polymers 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000010970 precious metal Substances 0.000 description 2
- 239000003566 sealing material Substances 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 240000007817 Olea europaea Species 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000007799 cork Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920001021 polysulfide Polymers 0.000 description 1
- -1 polytetrafluoroethylene Polymers 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/02—Mechanical actuation
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/20—Actuation by change of fluid pressure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H3/00—Mechanisms for operating contacts
- H01H3/22—Power arrangements internal to the switch for operating the driving mechanism
- H01H3/24—Power arrangements internal to the switch for operating the driving mechanism using pneumatic or hydraulic actuator
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H35/00—Switches operated by change of a physical condition
- H01H35/003—Switches operated by other part of human body than hands
Definitions
- ABSTRACT OF THE DISCLOSURE A pair of panels defining a heremtically sealed cavity placed under a controlled air pressure and having a switching means associated therewith which is responsive to a predetermined change in the air pressure to actuate an extemal circuit such as a relay alarm system.
- This invention relates to alarm apparatus.
- the present invention is alarm apparatus comprising two panels sealingly united together and entrapping therebetween a space or cavity wherein the pressure is less than atmospheric and holds inoperative a switch device in an electric circuit incorporating alarm means, said switch device being adapted to react to operate the alarm means on equalization of the pressures.
- the present invention is also alarm apparatus comprising two panels or laminations entrapping therebetween a space or cavity wherein the pressure is less than atmospheric and holds inoperative in an electrical circuit incorporating alarm means a switch device adapted to react to operate the alarm means on increase by a predetermined amount of the pressure in said space or cavity, said switch device comprising a pair of plates spaced apart at their peripheries by an insulating and sealing medium, one of said plates having a central outwardly-projecting stud providing an axial tapped through opening for adjustment of a threaded pin terminating in the space between the plates in a contact opposing another contact proud of a diaphragm secured at its periphery adjacent the other plate by said medium.
- One of the panels may be a window and the other a strip of glass sealingly united together at the periphery of the strip with a space or cavity between the two, a small hole in the panel or the strip locating the switch device.
- a window could form part of a door, or could form a door such as a showcase door.
- the two panels could form a partition wall, a window, a door, a floor, or a ceiling, or could be incorporated in a wall, a window, a door, a floor, or a ceiling.
- the panels may be sheets of polyvinyl chloride or other plastics material, or ferrous or non-ferrous metal, and the sealing together of the panels may be effected by heating, soldering, welding, adhesive, cement or other sealant, depending on the material or materials used.
- one of the panels is a strip there is no need to provide spacing means between the panels to keep the panels separated under vacuum, but if the areal dimensions of both panels are such that further support is desirable to keep the panels separated under vacuum spacing means in the form of small spacer elements may be disposed between the panels, preferably in a uniform pattern.
- the spacer elements are preferably bonded to at least one of the panels, and they may have openings therein defining between the panels spaces in which air is trapped on evacuation of air from between the panels, thus affording further support to the panels.
- the spacer elements could be of disc-shape of say A diameter and W thick.
- PVB a name applied in the trade to a sealing material which is a polyvinyl butyl resin containing, as a plasticiser, triethylene glycol di-Z-ethyl butyrate
- Teflon is a trade name for polytetrafluoroethylene
- Makrolon is a trade name for a thermoplastic polycarbonate of 4,4 -d1- hydroxy-diphenyl-Z,Z-propane (-biphenol A).
- the spacer elements could be replaced by wire netting, porous rigid foam material, or porous, corrugated sheet material, or one or more of the panels may 'be dimpled thus to obviate the need for spacer elements or wire netting. Where desirable a combination of any two or all three of the spacing means aforesaid may be used.
- the two panels sandwich a bag of nylon, polyvinylchloride, or other plastics material capable of supporting a vacuum of up to six or seven inches of mercury.
- the bag is held open by a porous foam sheet or by suitably positioned porous pipes, or by other means such as a corrugated sheet of porous plastics material, all with the object of ensuring that the bag will not collapse under vacuum.
- the bag closes off the space between the panels where confronting the obstacle.
- the invention can be used in ceilings, walls, floors, windows and doors, indeed anywhere subject to entry by force from without.
- FIG. 1 is a sectional view of two panels united together, positively spaced apart, with the outer of the two mounting a switch device and providing for communication of a pipe with the cavity between the panels;
- FIG. 2 is a similar view, on an enlarged scale, particularly illustrating the switch device
- FIG. 3 is a view similar to FIG. 2, but particularly illustrating the pipe communication with the cavity;
- FIG. 4 is a view similar to FIG. 1, illustrating a modification
- FIG. 5 is a plan view illustrating the use of the FIG. 4 construction
- FIG. 6 is a sectional view at right angles to that of FIG. 4 and to an enlarged scale, illustrating another modification
- FIG. 7 is a diagrammatic illustration of an installation where several double-panel structures are connected in series to a single vacuum pump and reservoir.
- two panels 10 and 11 of polyvinyl chloride or other plastics material entrap therebetween a space or cavity 12 in which is located spacing means in the form of wire netting 13.
- the panels are of convenient size for the purpose intended and are tailored to suit the surface or part-surface to which the composite structure is to be applied, the outside surface 14 of the inner panel 11 being then adjacent to the first-mentioned surface or part-surface and being adhered thereto in any convenient manner.
- the panel 10 has a peripheral flange which fits about the panel 11 and a sealing compound such as epoXy-polysulphide is provided between the panels at the peripheries thereof as shown at 101, and also externally of the panel 11 between same and the flange 100 as shown at 102.
- a sealing compound such as epoXy-polysulphide
- the outer panel has a hole formed therein and the tapped stem 16 of a bush 17 is located in said hole.
- the stem 16 has a peripheral groove 18 and the latter assists adhesion of the stem to the hole surround by means of a suitable adhesive or cementing compound such as Araldite (registered trademark).
- a longitudinal groove 19 is formed in the stem adjacent the tapped opening 20 and extends com pletely through the bush.
- the switch device 21 comprises a disc-shaped base plate 22 with a peripheral flange 23 and a central threaded stud 24 which screws into the tapped opening 20.
- the dimensions of the base plate 22 and the head 25 of the bush 16 are such that a small clearance is left between the flange 23 and the periphery of the head, and an O-ring seal 26 coated with silicone grease is compressed in said clearance as the switch device is screwed into position.
- An outer circular plate 27 is held in spaced and parallel relation to the base plate 22 by an annular ceramic spacer 28 which both seals the space 29 between the plates and locates in position a diaphragm 30 which has a central contact 31 of precious metal such as platinum proud of its surface opposed to the base plate 22.
- a hole 32 is provided in the base plate 22 and is aligned with the groove 19 so that the switch space 29 communicates with the space or cavity 12.
- the stud 24 has a central tapped opening 33 with a fine thread and in this is engaged a threaded pin 34 at whose end opposed to the diaphragm is a contact 35 also of precious metal such as platinum.
- the pin 34 enables adjustment of the setting of the switch device.
- the plate 27 has two small holes 36 therein for engagement by a suitable tool when assembling the switch device 21 to the bush 17. Care must be taken that the tool engages only to a limited extent in the holes 36 to avoid damage to the diaphragm 30.
- Two brass pins 37 and 38 extend from the base plate 22 and outer plate 27, respectively, and these serve for connecting the switch device to a relay controlling an alarm system.
- the diaphragm 30 On the space or cavity 12 being evacuated to provide therein a vacuum of the order of, say, 2.5 inches Hg, the diaphragm 30 is pulled and the contacts 31 and 35 close together. This locks the relay and the alarm system is inoperative. When the vacuum drops below a predetermined value, say 2 inches Hg, the diaphragm 30 flexes outwardly and pulls the contact 31 from the contact 35 breaking the electrical circuit and releasing the relay, thus operating the alarm system.
- a predetermined value say 2 inches Hg
- the function of the wire netting 13 or other spacing means is to prevent inward collapse of the panels when the space 12 is evacuated.
- the outer panel 10 has a second hole formed therein and the tapped stem 46 of a second bush 47 is located therein.
- the stem 46 has a peripheral groove 48 and the latter assists adhesion of the stem to the hole surround by means of a suitable adhesive compound or cementing compound such as Araldite.
- a pipe 49 has a threaded end 50 by means of which it is screwed into the tapped opening in the bush 47, and the pipe 49 serves for evacuating the space or cavity 12.
- a flow-restricting sleeve 51 is fitted into the pipe 49 close to the threaded end of the latter and this enables the evacuating pump to compensate for any slight loss of vacuum due to leakage at the junction between, on the one hand the bush 47 and the panel 10, and, on the other hand the pipe end 50 and the bush 47.
- the cavity or space 12 between the panels 10 and 11 is occupied by a bag of nylon or other plastics material which will support a vacuum of not less than 6 inches Hg.
- Flexible porous pipes 61 within the bag 60 prevent collapse of the bag under vacuum. This construction is especially useful when an obstacle is to be negotiated on a ceiling, wall, or the like, and referring particularly to FIG. 5, a light switch 62 is shown on a wall 63.
- the bag 60 is shaped to fit about the light switch 61 and, of course, the panels 10 and 11 have suitable openings cut therein.
- the edges of the bag walls about the shaped openings therein are sealed together and the space between the switch 62 and the double-panel structure is filled with a sealing material such as epoxypolysulphide.
- a sealing material such as epoxypolysulphide.
- the bags 60 may have an eyelet therein adjacent the longitudinal groove 19 in the stem 16 of the bush 17, but alternatively and preferably the connection with the switch 21 is effected in the manner now to be described with reference to FIG. 6.
- the pipes 65 are of nylon and are not porous and are clipped between the panels 10 and 11 with the ends of .the pipes interconnected by return-bends 66.
- the vacuum is in the pipes 65 and one end pipe is connected to the switch 21 and the other either blanked off or connected to an external pipe 49 in the same manner as will now be described for the connect-ion to the switch 21.
- the appropriate end pipe 65 is formed adjacent its free end 67 with a neck 68 leading into a reduced diameter.
- the reduced-diameter end 67 is coupled to a pipe elbow 69 which includes a coupling part 70 engaged by a screw nut 71 acting on an olive 72 which engages the wall of said end on tightening of the nut 71 and deforms said wall as indicated at 73.
- the other limb of the elbow 69 extends through a small hole 74 provided therefor in the panel 10 and is both externally threaded and internally tapped at its free end 80 besides having an intermediate peripheral ledge 75 with an out-turned flange 77 which butts against the inner surface 76 of the panel 10.
- a look ring 78 is screwed on to the free end 80 of the limb 69 externally of the panel 10, and has slots 79 which are engaged by a peg spanner when this is being done.
- the remainder of the construction is as described with reference to FIG. 2 save only that a second O-ring seal 81, coated with silicone grease and located by the flange 77 is compressed between the ledge 75 and the surface 76.
- a groove such as 19 (FIG. 2) and a hole such as 32 (FIG. 2) are provided in the FIG. 6 construction, although not seen, to enable communication between the switch space 29 and the cavity 12 between the panels 10 and 11.
- the eyeletted hole in the bag 60 is traversed by the pipe elbow 69 and the eyelet is engaged between the flange 77 and the surface 76.
- Double-panels forming part of alarm apparatus according to the invention may be fitted to walls, ceilings or floors by either adhesive or any other suitable and known method. Double-panels fitted to walls and ceilings may be covered by tiles or a layer of a plastics material, or have any other suitable surface finish. Double-panels fitted to floors may be made of steel or other strong material and covered by cork or other suitable covering material.
- Alarm actuating apparatus comprising:
- (c) means communicating with said cavity for estabiishing a predetermined air pressure less than atmospheric pressure in said cavity;
- a diaphragm mounted in said housing with one face in communication with said cavity through two of said openings and the other face in communication with atmosphere through another of said openings, a first electrical contact mounted on said diaphragm, a 'fixed adjustable second electrical contact mounted in said housing in alignment with said first contact, said diaphragm being movable in response to changes in said predetermined air pressure between a position wherein said contacts engage and a position wherein said contacts do not engage;
- said housing comprises:
- switching means further comprises:
- Alarm actuating apparatus as set forth in claim 1, further comprising an envelope of plastics material substantially filling said cavity, the interior of the envelope being in communication with said means for establishing said predetermined air pressure and with said one face of the diaphragm, and porous means in said envelope for preventing collapse of the envelope when evacuated.
- Alarm actuating apparatus as set forth in claim 1, further comprising a closed system of interconnected non-porous rigid pipes maintaining said panels in spaced relation, means connecting said system of pipes with one face of said diaphragm, and means connecting said system of pipes to said means for establishing said prede termined air pressure.
- Alarm actuating apparatus as set forth in claim 1, wherein said means to establish a predetermined air pressure comprises a pipe entering one of said openings, and means for evacuating said cavity through said pipe, a flow restricting sleeve in said pipe, and a pressure sensitive switch communicating with said pipe and energizing said means for evacuating said cavity when the vacuum in the pipe falls below a predetermined level.
- Alarm actuating apparatus comprising two panels sealingly united together to define therebetween a cavity wherein the pressure is less than atmospheric, a switch device adapted to operate an alarm means on increase by a predetermined amount of the pressure in said cavity, said switch device comprising a pair of plates mounted on said panels, an insulating and sealing medium spacing said plates apart at their peripheries to form a switch space, said switch space being in communication with said cavity, a central outwardly projecting stud in one of said plates and providing an axial tapped through opening, a threaded pin adjusta bly mounted in said opening and terminating in the space between the plates in a first contact, and a diaphragm secured at its periphery adjacent the other plate by said medium and mounting another contact at a position opposite said first contact, said diaphragm being movable responsive to a pressure increase in said cavity to open said contacts.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Burglar Alarm Systems (AREA)
- Basic Packing Technique (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB16123/65A GB1125754A (en) | 1965-04-14 | 1965-04-14 | Improvements relating to alarm apparatus |
GB133366 | 1966-01-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3374323A true US3374323A (en) | 1968-03-19 |
Family
ID=26236659
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US540865A Expired - Lifetime US3374323A (en) | 1965-04-14 | 1966-04-07 | Pressure responsive device for actuating an alarm |
Country Status (7)
Country | Link |
---|---|
US (1) | US3374323A (enrdf_load_stackoverflow) |
BE (1) | BE679528A (enrdf_load_stackoverflow) |
CH (1) | CH463328A (enrdf_load_stackoverflow) |
ES (1) | ES325393A1 (enrdf_load_stackoverflow) |
FR (1) | FR1494748A (enrdf_load_stackoverflow) |
GB (1) | GB1125754A (enrdf_load_stackoverflow) |
NL (1) | NL6605000A (enrdf_load_stackoverflow) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3573778A (en) * | 1968-11-01 | 1971-04-06 | Foxboro Co | Cantileverlike device in fluid-mechanical alarm |
US3593266A (en) * | 1969-10-16 | 1971-07-13 | Gen Motors Corp | Disc brake wear monitor system |
US3594763A (en) * | 1968-08-15 | 1971-07-20 | Cecil H Peek | Windows and the combination thereof with alarm means |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1062246B (it) * | 1976-06-21 | 1983-09-20 | Fontauto S N C | Dispositivo antifurto per la protezione contro tentativi di scasso |
DE3227397C2 (de) * | 1982-07-22 | 1986-06-19 | Securiton AG, Zollikofen, Bern | Bauelement zur Herstellung von einbruchsicheren Behältern oder Räumen |
EP0232388A1 (en) * | 1985-08-12 | 1987-08-19 | MILLAR, Frederick William | Security apparatus |
DE3921641A1 (de) * | 1989-06-30 | 1991-01-24 | Hoermann Kg Antrieb Steuertec | Sicherungsgeraet fuer die schliesskante eines torblattes |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1684530A (en) * | 1925-10-06 | 1928-09-18 | Charles Tagliabue Mfg Co | Pressure-controlled device |
FR706159A (fr) * | 1929-11-25 | 1931-06-19 | Relais à temps, notamment pour interrupteurs et inverseurs électriques | |
DE563348C (de) * | 1930-02-13 | 1932-11-03 | Egon Lewin | Elektropneumatische Sicherung gegen Einbruch |
US1974779A (en) * | 1931-10-23 | 1934-09-25 | John M Lupold | Burglar alarm |
US1986479A (en) * | 1929-12-27 | 1935-01-01 | Automatic Sprinkler Co | Means for supervising pneumatic fire alarm systems |
US2972132A (en) * | 1957-09-10 | 1961-02-14 | Charles B Putney | Control system |
-
1965
- 1965-04-14 GB GB16123/65A patent/GB1125754A/en not_active Expired
-
1966
- 1966-04-07 US US540865A patent/US3374323A/en not_active Expired - Lifetime
- 1966-04-12 ES ES0325393A patent/ES325393A1/es not_active Expired
- 1966-04-13 CH CH535466A patent/CH463328A/de unknown
- 1966-04-13 FR FR7782A patent/FR1494748A/fr not_active Expired
- 1966-04-14 NL NL6605000A patent/NL6605000A/xx unknown
- 1966-04-14 BE BE679528D patent/BE679528A/xx unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1684530A (en) * | 1925-10-06 | 1928-09-18 | Charles Tagliabue Mfg Co | Pressure-controlled device |
FR706159A (fr) * | 1929-11-25 | 1931-06-19 | Relais à temps, notamment pour interrupteurs et inverseurs électriques | |
US1986479A (en) * | 1929-12-27 | 1935-01-01 | Automatic Sprinkler Co | Means for supervising pneumatic fire alarm systems |
DE563348C (de) * | 1930-02-13 | 1932-11-03 | Egon Lewin | Elektropneumatische Sicherung gegen Einbruch |
US1974779A (en) * | 1931-10-23 | 1934-09-25 | John M Lupold | Burglar alarm |
US2972132A (en) * | 1957-09-10 | 1961-02-14 | Charles B Putney | Control system |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3594763A (en) * | 1968-08-15 | 1971-07-20 | Cecil H Peek | Windows and the combination thereof with alarm means |
US3573778A (en) * | 1968-11-01 | 1971-04-06 | Foxboro Co | Cantileverlike device in fluid-mechanical alarm |
US3593266A (en) * | 1969-10-16 | 1971-07-13 | Gen Motors Corp | Disc brake wear monitor system |
Also Published As
Publication number | Publication date |
---|---|
CH463328A (de) | 1968-09-30 |
FR1494748A (fr) | 1967-09-15 |
BE679528A (enrdf_load_stackoverflow) | 1966-09-16 |
ES325393A1 (es) | 1967-02-16 |
GB1125754A (en) | 1968-08-28 |
NL6605000A (enrdf_load_stackoverflow) | 1966-10-17 |
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