WO1990001200A1

WO1990001200A1 - Open/closed detector for window

Info

Publication number: WO1990001200A1
Application number: PCT/NO1989/000073
Authority: WO
Inventors: Gunnbjørn Edvard FLYUM
Original assignee: Comikron A/S
Priority date: 1988-07-20
Filing date: 1989-07-13
Publication date: 1990-02-08
Also published as: NO883231D0; NO883231L; NO165513B; NO165513C

Abstract

An open/closed detector for a window, where a switch function is achieved by opening/closing an electric circuit when the window is opened/closed. In the electric circuit are included elements which normally are parts of a window, namely hinges (3), casing latch point (5) and latch assembly (4). Metallic screws (7) form connections between an alarm central and the switch function of the detector via metal in window casing (1) and frame (2). One may favourably utilize already built-in steel reinforcements in the casing (1) and the frame (2). In the frame (2), possibly the latch assembly (4) itself may be utilized as the conductive metal.

Description

OPEN/CLOSED DETECTOR FOR WINDOW

The present invention concerns how to utilize existing components which are parts of a window, and particularly of a metal reinforced PVC window, in constructing a detector for sensing whether the window is open or closed, primarily for use in alarm systems. However, such a detector may also be utilized in the field relating to energy saving and similar fields.

In alarm systems related to windows, different kinds of detectors are often used. These detectors are most often after-installed on the windows. Ordinary types are magnetic or inductive switches, vibration switches and electrical current loops which are glued directly onto the window surface. However, such after-installing on the windows often create problems for the function to be executed by the detector. Furthermore, the physical mounting location often makes the detector rather vulnerable. Consequently, this also implies vulnerability of the alarm installation as such.

From US patent no. 1.556.626 is known an electrial detector for burglar attempts through a window, wherein metal plates in the door casing and the door frame are intended to make contact with each other and close an electric circuit when force is used on the window in order to break the window open. Thus, this detector, which apparently may resemble a little the present invention, has a somewhat different function, namely detecting burglary, but not in itself detecting whether a window is in an open or a closed position. The electric circuit will be open both when the window is closed and when the window is open, and therefore this circuit cannot detect a normal opening of the window at all. It should also be noted that the casing latch point and the door latch assembly in this case are not included in the electric circuit, in contrast with the present invention.

US patent 3.147.468 discloses something which to some extent is similar to "utilizing the jamb latch point and the window latch assembly in the electric circuit", i.e. the latch bolt in a lock is used for closing an electrical contact device inside the latch point in the window jamb or window casing. However, the complete electric system is in this case mounted inside the jamb (plus a small conductor piece on the latch bolt) , and this equipment is a typical after-installing equipment. However, detection of normal opening/closing of th window is achieved in about the same manner as in the present invention, but with a different technical solution.

In contrast to the prior art, the present invention provides an opportunity to utilize components which are alread installed during the normal window production, as parts of a detection system. Essential components of the detector are.a natural part of the window. Therefore, it will not be necessa to connect external transducers to give information about the window status to an alarm system. The open/closed detector in accordance with the invention is built-in and therefore hidden from the surroundings. This reduces the vulnerability of the function which the alarm system is to serve.

The purposes stated above are achieved in accordance with the invention, by a detector constructed as appears from the patent claims below.

A closer description of the invention shall be made by referring to some non-limiting embodiments, and referring to the enclosed drawing figures, where

Fig. 1 and fig. 2 show those elements that are present in windows of standard types, fig. 3 displays the use of self-tapping screws for connecting latch point and possibly a spring steel plate to metal inside a window casing (window jamb) , and how a self- tapping screw may provide electrical contact for the wire to b connected to the alarm central, and fig. 4 shows schematically the electric circuit.

If is first referred to figs, l and 2, where two standard type windows are shown. Reference numeral 1 shows the window casing (window jamb) , while 2 is the window frame. The window jamb 1 is equipped with electrically conducting metal on those sides where latch point 5 and hinges 3 are mounted. These respective metal parts are not in physical, i.e. electrical contact with each other. The metal may either be provided on the outside of the jamb or casing 1, or it may be placed insid the casing. For wood windows, it will be the simplest method drill longitudinal pieces of metal tubes into the casing. However, the present invention is particulary suitable regardi PVC windows, in which case the electrically conducting path of the casing or jamb 1 is constituted by the metal reinforcement already built into the PVC profiles. The jamb latch point 5 and the hinges 3 are connected separately to their respective metal parts inside the jamb by means of conducting screws 7 (fig. 3). If metal 9 inside the jamb is used, self-tapping screws 7 are utilized. When using metal placed on the outside of the window jamb, it is also possible to utilize through bolts with nuts.

Regarding the window frame 2 as opposed to the window casing 1, it is necessary that physical, i.e. electrical contact exists between the different sides of the frame 2 which are to be used for the switch function in the detector. The window latch assembly 4 can be utilized as such metal , whether the latch assembly is of a type placed on the outside of the frame 2, see fig. 2, or it is of a type located inside the frame, see fig. 1. If the window latch assembly 4 does not satisfy this requirement, the frame 2 must be equipped with conductive metal in the same manner as the window ja b 1, and the latch assembly 4 and the hinges 3 must be connected electrically with this metal.

One contact spot of the detector is the latch point 5 in the window jamb 1, and the other contact spot is the latch assembly 4 in the window frame 2. When the window is closed an the latch assembly operating device, e.g. a handle- 6, is in closing position, the latch assembly 4 and the latch point 5 will be in physical contact with each other. Then the switch function of the detector is closed. In the opposite case, the switch function is open.

Not all latch points are constructed of metal. Besides, one cannot always be 100 % sure that the physical contact between latch assembly 4 and latch point 5 is good enough. Therefore, in such cases the jamb latch point 5 is provided with a spring steel plate 8, or a similar, electrically conductive spring device, which is fixed by means of a screw. When possible, a fixing screw for the latch point itself is als used as fixing screw for the spring steel plate. In fig. 3 is also shown a plastic cap 10 for insulating a connecting screw, and reference numeral 11 shows a connecting wire to an alarm central.

Fig. 4 shows quite schematically the electric circuit, which may consist of a simple series circuit through the voltage source and the detector instrument, which do not in themselves constitute any part of the present invention, and further into the window jamb 1 on two sides, which sides do not have any electrical connection with each other. The connection to the conducting metal in the jamb 1 on the two sides are made for example as shown in fig. 3 , with a screw which is covered by a plastic cap. On the left side of the embodiment of fig. 4, the metal conductor in the window casing 1 provides an electrical path up to the latch point 5, where electric connection also is provided as displayed in fig. 3, by means of screws. In the same manner there is an electrical path on the right side of the jamb up to the hinge 3, and the hinge itself provides an electrical connection between casing 1 and frame 2 on this side. In the window frame 2 there is a continuous conducting path via built-in metal all the way up to the latch assembly 4. Thus, when the window is closed and the handle 6 is operated, the electric circuit is closed in this switch point, which consists of the latch assembly 4 and the latch point 5.

Claims

P A T E N T C L A I M S

1. An open/closed detector for a window, where casing latch point (5) , window latch assembly (4) and hinges (3) are used as series elements in an electric circuit in order to provide a switch function for an alarm system, c h a r a c t e r i z e d by the fact that said casing latch point (5) , said window latch assembly (4) and said hinges (3) are connected with said alarm system via metal in the window casing (1) and the window frame (2) .

2. A detector as claimed in claim 1, c h a r a c t e r i z e d by the fact that electrically conducting screws (7) connect said casing latch point (5) , said hinges (3) and said window latch assembly (4) to said metal (9) in said casing and said frame (2) .

3. A detector as claimed in claim 1 or 2 , c h a r a c t e r i z e d by the fact that said window latch assembly (4) also constitutes the conducting metal in the window frame (2) .

4. A detector as claimed in claim 1, 2 or 3, where the window is a PVC type window with built-in steel reinforcement, c h a r a c t e r i z e d by the fact that the conducting metal is constituted by the steel reinforcement.

5. A detector as claimed in one of the previous claims, c h a r a c t e r i z e d by the fact that electrically conductive metal connects two or more sides of the window frame (2).

6. An open/closed detector for a window, where an electric circuit is broken when the window is opened, c h a r a c t e r i z e d by the fact that said circuit comprises the window casing latch point (5) , the window latch assembly (4) and at least one of the window hinges (3) in a series connection, electrical contact between latch point (5) and latch assembly (4) only occuring by direct mechanical contact when the latch assembly operating device (6) is in a closed position.

7. A detector as claimed in claim 6, c h a r a c t e r i z e d by the fact that said latch assembly (4) also constitutes the hinge function, said circuit then comprising the window casing latch point (5) and latch assembly (4) connected in series.

8. The use of metallic construction elements of a window, particularly metal reinforcements in a PVC window, as electri¬ cally conductive paths in an electric circuit for detecting whether the window is open or closed, where the window casing latch point (5) , the window latch assembly (4) and at least one of the window hinges (3) take part as serially connected elements in said circuit.