CA1196519A - Tamper-proof alarm bell assembly - Google Patents
Tamper-proof alarm bell assemblyInfo
- Publication number
- CA1196519A CA1196519A CA000403174A CA403174A CA1196519A CA 1196519 A CA1196519 A CA 1196519A CA 000403174 A CA000403174 A CA 000403174A CA 403174 A CA403174 A CA 403174A CA 1196519 A CA1196519 A CA 1196519A
- Authority
- CA
- Canada
- Prior art keywords
- control circuit
- detector
- assembly according
- bell
- alarm
- 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
Links
Landscapes
- Burglar Alarm Systems (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An alarm bell assembly is provided herein, the bell assembly includes a gong and bell operating parts on a mounting, the operating parts being concealed and protected by the gong, and preferably also a cover for the assembly. The bell assembly is secured by means comprising a detector, such as a micro-switch, by which the bell is actuable when the securing means is tampered with. A rechargeable battery is connected to an external control circuit such that the battery remains fully charged and supplies the alarm drive if the control circuit connected is served.
Thus the alarm bell is sounded if a prospective burglar or intruder attempts to dismantle the assembly, since the gong and the cover are secured to the assembly in such a way as to be in operable contact with the micro-switch which is connected with the power source and bell operating means. The assembly will therefore sound the alarm on being meddled with, and so serve to disturb burglars and intruders and prevent the alarm being disable.
An alarm bell assembly is provided herein, the bell assembly includes a gong and bell operating parts on a mounting, the operating parts being concealed and protected by the gong, and preferably also a cover for the assembly. The bell assembly is secured by means comprising a detector, such as a micro-switch, by which the bell is actuable when the securing means is tampered with. A rechargeable battery is connected to an external control circuit such that the battery remains fully charged and supplies the alarm drive if the control circuit connected is served.
Thus the alarm bell is sounded if a prospective burglar or intruder attempts to dismantle the assembly, since the gong and the cover are secured to the assembly in such a way as to be in operable contact with the micro-switch which is connected with the power source and bell operating means. The assembly will therefore sound the alarm on being meddled with, and so serve to disturb burglars and intruders and prevent the alarm being disable.
Description
The present invention relates -to alarm bell assemblies and particularly to a tamper-proof intruder alarm mounted in use on buildings, usually on an outside wall.
Conventional alarms have a steel cover, the thickness of which must be at least l~ gauge or a polycarbonate cover the thic1cness of which must be at least 3 mm., in order to comply e.g. with Bri-tish Standards.
IJnderneath the cover there is a base plate, also of 18 gauge steel or 3 mm.
polycarbonate on which are mounced a gong, bell operating parts including an armature and armature drive means, and a power source, usually including batteries and wires to a central alarm control circuit.
Enterprising prospective burglars and intruders can easily disabled such alarms, for example, by cutting through the cover and removing the batteries or cutting the wires to the control cireuit or both. The alarm is rendered inoperative and, hence, ineffective. Such alarms are, therefore, not very satisfaetory.
An alarm which obviates these disadvantages is required in oxder to foil attempting burglars and intruders.
According to a broad aspect of this invention, an alarm bell assembly is provided comprising a gong and bell operating parts in which the operating parts are located beneath and protected by the gong, the operating parts being seeured to the mounting by securing means comprising a deteetor by which the bell is aetuable when the securing means is tampered with.
By one variant thereof, the gong is secured by screwed means, ~nt o~ whieh triggers the deteetor.
By another variant thereof, a cover for the assembly is also seeuxed by serewecl means, - v, -~t of whieh triggers the deteetor.
By still another variant thereof the gong is secured by a first screw and the cover is secured by a second screw co-axially within the first screw.
By a ~urther variant thereof, the mounting comprises a frame having a central boss within which the detector is located.
By yet another variant thereof, the detector comprises a micro-switch.
By still another variant thereof, the bell operating parts comprise an alarm drive means and a rechargeable battery, and such parts are connected to or adapted for connection to, an external control circuit such that the battery is kept fully charged and supplies the alarm drive means if the control circuit connection is sevared.
In a preferred embodiment~the alarm includes a plastics external cover, a steel base and a frame on the base, the cover being secured to the ~rame by a screw and the gong being secured to the frame ~y a second screw, the cover screw being located coaxiaily within the gony screw. The detector comprises a micro-switch, located within an aperture defined by a raised portion of the frame and is operable on any of the following: removal of the cover screw; or removal of the gong screw; or removal of the alarm assembly; or v L of the alarm assembly.
The power source preferably comprises a standby rechargeable battery, a relay and battery charging circuit on a printed circuit board to an e~ternal central alarm control circuit such that the battery is kept ~ully charged and ~upplies the alarm drive means if the control circuit connections are severed.
~ hus the alarm bell assembly cannot be t~ cled with without the micro-swltch bei~ng triggered and the alarm sounding, thus disturbing anyone n$ wlth thle a~se~oly-Fux~he ~_`d, a plastics cover may be used because the gong affords the bell operating means mechanical proteckion and this reduces themanufacturing oost of the alarm bell assembly and also results in an attrac-tive, weather-proof assembly.
one embodiment of the present invention will now be described by way of example and with reference to the acc~m~Rnying drawings, in which:-Fig 1 is a cross-section taken from one side through ~he centre of an alarm bell assembly of an aspect of this invention, including a gong and a cover;
Fig. 2 is a front elevation of the alarm bell asse-mbly~ with the cover and gong removed; and ~ ig. 3 is a circuit diagram showing the printed circuit board and connections therefrom to an alarm system control circuit, a battery, a bell and a micro-switch.
An alarm bell assembly 13.for use as an intruder alarm has a steel base plate 1 and frame 2 mounted on the base plate, both of which may be fixed to a building by means of scre~s 3. The assembly has a plastics, outer cover 4, shown in Fig. 1, which completely extends over the top and the sides of a gong 5.
The gong 5 entirely surrounds the bell operating means seated on the base frame 2, which comprise an armature and armature drive meohAn;qm 6 including an electric motor, a printed circuit board 7 and a rechargeable battery 8.
A central raised portion 9 of the base frame defines an aperture which houses a micro-switch 10. This micro-switch serves to detect tampering and may be triggered when a screw 11, securing the outer cover 4 to the base is turned or when another screw 12 is turned or when an attempt is made to move the cover 4l~ on the gong 5.
f~' - 3 - ~
The screw 12 is located cn~ 11 y within the screw 12 which secures the gong 5 to the base plate 1.
The printed circuit board 7, as shown in Fig. 3, includes a relay A from an external ala~m system control circuit. The battery 8 is kept fully charged via the relay A.
If the micro-switch 10 is triggered via the oover 4 or the gong 5, then return voltage is lost to the control circuit and a relay contact A2 is open; the bell is then supplied by the circuit via relay A and, simultaneously, police are alerted by the external circuit control box.
If the control circuit supply is prevented, for example by the assembly being pulled ofÆ the wall, by an intruder, for example, and the wires being severed, then the battery 8 supplies the bell.
Thus, the alarm bell is spunded if a prospective burgular or intruder attempts to dismantle the assembly as a re~ult of the gong and the cover belng secured to the asse~bly in such a way as to be in operable contact with the micro-switch, which is connected with the power source and bell operating means.
The assembly~will, therefore, sound the alarm on being meddled with and 90 serve to distuxb burglars and intxuders and prevent the alarm being disabled.
Conventional alarms have a steel cover, the thickness of which must be at least l~ gauge or a polycarbonate cover the thic1cness of which must be at least 3 mm., in order to comply e.g. with Bri-tish Standards.
IJnderneath the cover there is a base plate, also of 18 gauge steel or 3 mm.
polycarbonate on which are mounced a gong, bell operating parts including an armature and armature drive means, and a power source, usually including batteries and wires to a central alarm control circuit.
Enterprising prospective burglars and intruders can easily disabled such alarms, for example, by cutting through the cover and removing the batteries or cutting the wires to the control cireuit or both. The alarm is rendered inoperative and, hence, ineffective. Such alarms are, therefore, not very satisfaetory.
An alarm which obviates these disadvantages is required in oxder to foil attempting burglars and intruders.
According to a broad aspect of this invention, an alarm bell assembly is provided comprising a gong and bell operating parts in which the operating parts are located beneath and protected by the gong, the operating parts being seeured to the mounting by securing means comprising a deteetor by which the bell is aetuable when the securing means is tampered with.
By one variant thereof, the gong is secured by screwed means, ~nt o~ whieh triggers the deteetor.
By another variant thereof, a cover for the assembly is also seeuxed by serewecl means, - v, -~t of whieh triggers the deteetor.
By still another variant thereof the gong is secured by a first screw and the cover is secured by a second screw co-axially within the first screw.
By a ~urther variant thereof, the mounting comprises a frame having a central boss within which the detector is located.
By yet another variant thereof, the detector comprises a micro-switch.
By still another variant thereof, the bell operating parts comprise an alarm drive means and a rechargeable battery, and such parts are connected to or adapted for connection to, an external control circuit such that the battery is kept fully charged and supplies the alarm drive means if the control circuit connection is sevared.
In a preferred embodiment~the alarm includes a plastics external cover, a steel base and a frame on the base, the cover being secured to the ~rame by a screw and the gong being secured to the frame ~y a second screw, the cover screw being located coaxiaily within the gony screw. The detector comprises a micro-switch, located within an aperture defined by a raised portion of the frame and is operable on any of the following: removal of the cover screw; or removal of the gong screw; or removal of the alarm assembly; or v L of the alarm assembly.
The power source preferably comprises a standby rechargeable battery, a relay and battery charging circuit on a printed circuit board to an e~ternal central alarm control circuit such that the battery is kept ~ully charged and ~upplies the alarm drive means if the control circuit connections are severed.
~ hus the alarm bell assembly cannot be t~ cled with without the micro-swltch bei~ng triggered and the alarm sounding, thus disturbing anyone n$ wlth thle a~se~oly-Fux~he ~_`d, a plastics cover may be used because the gong affords the bell operating means mechanical proteckion and this reduces themanufacturing oost of the alarm bell assembly and also results in an attrac-tive, weather-proof assembly.
one embodiment of the present invention will now be described by way of example and with reference to the acc~m~Rnying drawings, in which:-Fig 1 is a cross-section taken from one side through ~he centre of an alarm bell assembly of an aspect of this invention, including a gong and a cover;
Fig. 2 is a front elevation of the alarm bell asse-mbly~ with the cover and gong removed; and ~ ig. 3 is a circuit diagram showing the printed circuit board and connections therefrom to an alarm system control circuit, a battery, a bell and a micro-switch.
An alarm bell assembly 13.for use as an intruder alarm has a steel base plate 1 and frame 2 mounted on the base plate, both of which may be fixed to a building by means of scre~s 3. The assembly has a plastics, outer cover 4, shown in Fig. 1, which completely extends over the top and the sides of a gong 5.
The gong 5 entirely surrounds the bell operating means seated on the base frame 2, which comprise an armature and armature drive meohAn;qm 6 including an electric motor, a printed circuit board 7 and a rechargeable battery 8.
A central raised portion 9 of the base frame defines an aperture which houses a micro-switch 10. This micro-switch serves to detect tampering and may be triggered when a screw 11, securing the outer cover 4 to the base is turned or when another screw 12 is turned or when an attempt is made to move the cover 4l~ on the gong 5.
f~' - 3 - ~
The screw 12 is located cn~ 11 y within the screw 12 which secures the gong 5 to the base plate 1.
The printed circuit board 7, as shown in Fig. 3, includes a relay A from an external ala~m system control circuit. The battery 8 is kept fully charged via the relay A.
If the micro-switch 10 is triggered via the oover 4 or the gong 5, then return voltage is lost to the control circuit and a relay contact A2 is open; the bell is then supplied by the circuit via relay A and, simultaneously, police are alerted by the external circuit control box.
If the control circuit supply is prevented, for example by the assembly being pulled ofÆ the wall, by an intruder, for example, and the wires being severed, then the battery 8 supplies the bell.
Thus, the alarm bell is spunded if a prospective burgular or intruder attempts to dismantle the assembly as a re~ult of the gong and the cover belng secured to the asse~bly in such a way as to be in operable contact with the micro-switch, which is connected with the power source and bell operating means.
The assembly~will, therefore, sound the alarm on being meddled with and 90 serve to distuxb burglars and intxuders and prevent the alarm being disabled.
Claims (20)
1. An alarm bell assembly comprising: a gong; and bell operating parts on a mounting; the operating parts being concealed and protected by said gong, said operating parts secured to said mounting by securing means comprising: a DETECTOR by which said bell is actuable when said securing means is tampered with.
2. An assembly according to claim 1 wherein said gong is secured by screwed means, movement of which triggers said detector.
3. An assembly according to Claim 1 wherein said assembly includes a cover which is also secured by screwed means, movement of which triggers said detector.
4. An assembly according to Claim 2 wherein said assembly includes a cover which is also secured by screwed means, movement of which triggers said detector.
5. An assembly according to Claim 3 wherein said gong is secured by a first screw, and wherein said cover is secured by a screw co-axially within said first screw.
6. An assembly according to Claim 4 wherein said gong is secured by a first screw, and wherein said cover is secured by a screw co-axially within said first screw.
7. An assembly according to Claims 1, 2 or 3 wherein said mounting comprises a frame having a central boss, within which said detector is located.
8. An assembly according to Claims 4, 5 or 6 wherein said mounting comprises a frame having a central boss, within which said detector is located.
9. An assembly according to Claims 1, 2 or 3 wherein said detector comprises a micro-switch.
10. An assembly according to Claims 4, 5 or 6 wherein said detector comprises a micro-switch.
11. An assembly according to Claims 1, 2 or 3 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said detector comprises a micro-switch.
12. An assembly according to Claims 4, 5 or 6 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said detector comprises a micro-switch.
13. An assembly according to Claims 1, 2 or 3 wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
14. An assembly according to Claims 4, 5 or 6 wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed
15. An assembly according to Claims 1, 2 or 3 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
16. An assembly according to Claims 4, 5 or 6 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
17. An assembly according to Claims 1, 2 or 3 wherein said detector comprises a micro-switch and wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
18. An assembly according to Claims 4, 5 or 6 wherein said detector comprises a micro-switch and wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
19. An assembly according to Claims 1, 2 or 3 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said detector comprises a micro-switch and further wherein said bell operating parts comprise; an alarm drive means, and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
20. An assembly according to Claims 4, 5 or 6 wherein said mounting comprises a frame having a central boss, within which said detector is located and wherein said detector comprises a micro-switch and further wherein said bell operating parts comprise; an alarm drive means; and a rechargeable battery; and wherein said parts are connected to, or are adapted for connection to, an external control circuit such that said battery is kept fully charged and supplies said alarm drive means if said control circuit connection is severed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000403174A CA1196519A (en) | 1982-05-18 | 1982-05-18 | Tamper-proof alarm bell assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000403174A CA1196519A (en) | 1982-05-18 | 1982-05-18 | Tamper-proof alarm bell assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1196519A true CA1196519A (en) | 1985-11-12 |
Family
ID=4122802
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000403174A Expired CA1196519A (en) | 1982-05-18 | 1982-05-18 | Tamper-proof alarm bell assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1196519A (en) |
-
1982
- 1982-05-18 CA CA000403174A patent/CA1196519A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |