Abstract of
GB1406891
1406891 Monitoring impacts MATHER & PLATT Ltd 14 Dec 1973 [15 Dec 1972] 57957/72 Headings G1N and G1W A detector element is formed with a conductive path which is broken when subjected to a predetermined impact strength. A cylindrical plastics member 4 is connected by three arms 3 to a central tip 1, comprising a temperature sensitive transducer, in an annular member 2. Each arm has a sharp-cornered notch 8. The inner surface of the cylinder 4 and the arms 3 are provided with a conductive coating 9 which is joined at the tip to a wire 10. The cylindrical member 4 is fixed by a flange 5, and a force of a predetermined magnitude when supplied to the tip 1 causes the arms 3 to break at the notches 8, thereby breaking the circuit from the coating 9 to the tip 1, and energizing an alarm. An alarm circuit could be provided for each arm 3.
+ PATENT SEALED; - PATENT CEASED THROUGH NON-PAYMENT OF RENEWAL FEE
INPADOC patent family
1
DETECTORS
Inventor:
Applicant: MATHER & PLATT LTD
EC:G08B17/00
IPC: G08B17/00;G08B17/00; (IPC1-7): G08B21/00
Publication info: GB1406891 A - 1975-09-17
List of citing documents
1
PRESSURE SENSOR
Inventor:
Applicant: NISSAN MOTOR (JP)
EC:G01L9/00D2B2; G01L9/00D2F; (+1)
IPC: G01L9/04; G01L9/00; H01L29/84(+5)
Publication info: FR2446471 - 1980-08-08
Claims
**WARNING** start of CLMS field may overlap end of DESC **.
"no-signal" indication of a fault.
The cylindrical and annular members 4 and 2 respectively, and the arm 3 are preferably formed as a single plastics moulding.
It will be understood that the present invention can be used with transducers other than heat-sensitive detectors, and that transducers having more than two connections can be accommodated. For example, in the embodiment described herein, the wire 10 could have a plurality of cores, and/or separate conductive paths could be provided along each arm 3.
It will also be understood that a variety of supports could be provided for the transducer. The described embodiment has three arms 3 so that a blow of sufficient force in any direction would break each of them satisfactorily.
WHAT WE CLAIM IS:
1. A detector comprising a housing constituted by a support and at least one electrically conductive path carried by the support, the support being adapted to have a transducer mounted thereon in electrical contact with the or each conductive path and to be breakable when subjected to an impact of more than a predetermined force from one or more directions so as to break the or each electrically conductive path.
2. A detector as claimed in claim 1 in which a transducer is mounted on the suport in electrical contact with the or each electrically conductive path.
3. A detector as claimed in claim 1 or 2 in which the or each electrically conductive path comprises an electrically conductive coating deposited on the surface of the support.
4. A detector as claimed in any one of claims 1 to 3 in which the support comprises one or more members of a breakable plastics material having one or more built-in weak points therein, for example notches.
5. A detector substantially as described hereinbefore with reference to the accompanying drawing.
Description
(54) IMPROVEMENTS IN OR RELATING TO
DETECTORS
(71) We, MATHER & PLATT
LIMITED, a British Company of Park
Works, Manchester, M106BA, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the followingstatement:-
The present invention relates to detectors, for example heat-sensitive point detectors, and to housings for such detectors.
It is an object of the present invention to provide a detector and a housing for the detector which, when subjected to an impact of greater than a predetermined force, gives a continuous fault, or alarm signal.
According to the present invention there is provided a detector comprising a housing constituted by a support and at least one electrically conductive path carried by the support, the support being adapted to have a transducer mounted thereon in electrical contact with the or each conductive path and to be breakable when subjected to an impact of more than a predetermined force from one or more directions so as to break the or each electrically conductive path.
Preferably, a transducer is mounted on the support in electrical contact with the or each electrically conductive path.
The or each electrically conductive path can comprise an electrically conductive coating deposited on the surface of the support. The support may comprise one or more members of a breakable plastics material having one or more built-in weak points therein, for example notches.
This invention will now be further described by way of example with reference to the accompanying drawing inwhich:
Fig. 1 is a plan view of a detector.
Fig. 2 is a section taken along the line11-11 of Fig. 1.
A detector is provided which comprises a heat-sensitive detector tip 1 mounted in an annular member 2 fixed by three arms 3 to one end of a cylindrical member 4. The centre of the annular member 2 lies outside the cylindrical member 4 on the axis thereof, and the arms 3 subtend an angle of approximately 450 with the said axis and are arranged thereabout at intervals of substantially 1200. The said end of the cylindrical member 4 is provided with an outwardly directed flange 5 having holes 6 therethrough to facilitate the fitting of the detector in a desired location.
The cylindrical member 4 may be provided with inwardly projecting depressions 7 adjacent the holes to increase the effective width of the flange in the region of the holes. These depressions preferably extend in the axial direction for the entire length of the cylindrical member.
Each arm 3 has a sharp-cornered notch 8 across its length, the notches facing the interior of the cylindrical member 4.
The interior of the cylindrical member 4 and the notched side of each arm 3 is provided with an electrically conductive coating 9, and a wire 10 passes through the cylindrical member 4 directly to the detector tip 1. The tip is also in electrical contact with the coating on the arm 3 and thus a circuit can be formed incorporating the coating 9, the tip 1 and the wire 10.
The thickness of the arm 3 and the depth of the notches 8 therein are selected so that each arm 3 is broken in the region of the notches 8 if the tip 1 is subjected to an impact of greater than a predetermined force. The predetermined force is selected to be less than that which would damage accuracy or reliability of the tip 1. An impact which would break the arms 3 would also break the coating 9 thereon, and the breakage of the coating 9 could be used to either electrically trigger an alarm or give a "no-signal" indication of a fault.
The cylindrical and annular members 4 and 2 respectively, and the arm 3 are preferably formed as a single plastics moulding.
It will be understood that the present invention can be used with transducers other than heat-sensitive detectors, and that transducers having more than two connections can be accommodated. For example, in the embodiment described herein, the wire 10 could have a plurality of cores, and/or separate conductive paths could be provided along each arm 3.
It will also be understood that a variety of supports could be provided for the transducer. The described embodiment has three arms 3 so that a blow of sufficient force in any direction would break each of them satisfactorily.
WHAT WE CLAIM IS:
1. A detector comprising a housing constituted by a support and at least one electrically conductive path carried by the support, the support being adapted to have a transducer mounted thereon in electrical contact with the or each conductive path and to be breakable when subjected to an impact of more than a predetermined force from one or more directions so as to break the or each electrically conductive path.
2. A detector as claimed in claim 1 in which a transducer is mounted on the suport in electrical contact with the or each electrically conductive path.
3. A detector as claimed in claim 1 or 2 in which the or each electrically conductive path comprises an electrically conductive coating deposited on the surface of the support.
4. A detector as claimed in any one of claims 1 to 3 in which the support comprises one or more members of a breakable plastics material having one or more built-in weak points therein, for example notches.
5. A detector substantially as described hereinbefore with reference to the accompanying drawing.
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