GB2131230A - Electric switching devices - Google Patents

Abstract

An electric switch device has a plurality of reed contact units 20 encapsulated within a single glass container 30. One terminal of each contact unit 20 is connected to a common lead. The glass container 30 is located within an outer tube 10 on which a floating magnet is slidable. <IMAGE>

Description

SPECIFICATION Improvement relating to electrical switch devices This invention relates to an electric switch devie.

More particularly, the invention has application in electrical switch devices having a plurality of reed switches to activate or de-activate electrical equipment and where it is necessary to have said reed switches permanently located at an exact distance away from each other.

It is an object of the present invention to obviate or mitigate the above disadvantages and to provide means whereby two or more reed switches can be precisely located at a predetermined distance apart.

Such a requirement is described in my co-pending UK patent application no. 8010723 where two reed switches are enclsoed within a tube which is surrounded by a floating magnet and where said floating magnet is slidable on the tube and moves up or down the exterior of the tube which itself is placed inside a container holding liquid and where the height of the floating magnet is determined by the quantity of liquid inside the container.

As stated, the level of the liquid in the container controls the height of the floating magnet which, when it comes within close predetermined proximity with the reed switches, activates them to make or break electrical contact.

Presently, it is necessary to locate two encapsulated reed switches inside a tube and it is very difficult and time consuming to precisely locate said switches at an exact, predetermined distance apart and also at a precise predetermined point within the tube so, that in the manufacture of large quanitities of the device for which the reed switches are required, all are precisely and exactly similar.

Also, where a plurality of separate encapsulated reed swtiches are to be placed inside a tube the tube itself is, of necessity, of a considerably larger size than would be required if only one encapsulation was used.

According to the present invention there is provided an electrical switch device comprising a plurality of electrical switches encapsulated within a single glass container.

Thus, an improved electrical switch device is provided wherein the required number of reed switches share a common container instead of each reed switch having its own separate container.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates an embodiment of a prior art switch device for operating an air bleeding device for diesel engines; and Figure 2 illustrates one embodiment of an electrical switch device made in accordance with the present invention.

Referring to the drawings, Figure 1 illustrates a switch device for operating a diesel engine air bleeding device as described in my earlier application no. 8020723.

In this arrangement a pair of reed switches 2 are required to be located at a predetermined distance apartwithin an outertube 1. Each reed switch 2 is encapsulated within its own glass container 3 and, in use, the respective glass containers must be located at a precise point within the tube 1 and at the pre-required distance apart. Accordingly, considerable care is required in the manufacture of switch devices having a plurality of reed switches each of which is individually encapsulated.

In Figure 2, there is illustrated one embodiment of a switch device made in accordance with the present invention.

in accordance with the invention two reed switches 20 are located within a glass container 30 which is in turn located at the desired point within an outer tube 10 which forms part of the air bleeding device.

Since the reed switches 2 are located within the glass container 3 during the manufacture of the switch itself then the desired spacing of the reed switches is assured. It is then a simple matter to fix the other container 30 inside the tube 10. The reed switches 20 are provided with respective leads 21, 22, 23, the lead 23 being common to one terminal of each switch.

Modifications and improvements may be incorporated without departing from the scope of the invention, for example a larger number of reed switches may be provided. The container 30 may be provided with indexing means to cooperate with similar means on the inside of the tube 10 to ensure consistent location of the container 30 within the tube 10.

1. An electrical switch device comprising a plurality of electrical switches encapsulated within a single glass container.

2. A switch device as claimed in claim 1 wherein the switches are reed switches.

3. A switch device as claimed in any preceding claim wherein one terminal of each switch is connected to a common lead.

4. An electric switch device substantially as herein before described with reference to Figure 2 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvement relating to electrical switch devices This invention relates to an electric switch devie. More particularly, the invention has application in electrical switch devices having a plurality of reed switches to activate or de-activate electrical equipment and where it is necessary to have said reed switches permanently located at an exact distance away from each other. It is an object of the present invention to obviate or mitigate the above disadvantages and to provide means whereby two or more reed switches can be precisely located at a predetermined distance apart. Such a requirement is described in my co-pending UK patent application no. 8010723 where two reed switches are enclsoed within a tube which is surrounded by a floating magnet and where said floating magnet is slidable on the tube and moves up or down the exterior of the tube which itself is placed inside a container holding liquid and where the height of the floating magnet is determined by the quantity of liquid inside the container. As stated, the level of the liquid in the container controls the height of the floating magnet which, when it comes within close predetermined proximity with the reed switches, activates them to make or break electrical contact. Presently, it is necessary to locate two encapsulated reed switches inside a tube and it is very difficult and time consuming to precisely locate said switches at an exact, predetermined distance apart and also at a precise predetermined point within the tube so, that in the manufacture of large quanitities of the device for which the reed switches are required, all are precisely and exactly similar. Also, where a plurality of separate encapsulated reed swtiches are to be placed inside a tube the tube itself is, of necessity, of a considerably larger size than would be required if only one encapsulation was used. According to the present invention there is provided an electrical switch device comprising a plurality of electrical switches encapsulated within a single glass container. Thus, an improved electrical switch device is provided wherein the required number of reed switches share a common container instead of each reed switch having its own separate container. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates an embodiment of a prior art switch device for operating an air bleeding device for diesel engines; and Figure 2 illustrates one embodiment of an electrical switch device made in accordance with the present invention. Referring to the drawings, Figure 1 illustrates a switch device for operating a diesel engine air bleeding device as described in my earlier application no. 8020723. In this arrangement a pair of reed switches 2 are required to be located at a predetermined distance apartwithin an outertube 1. Each reed switch 2 is encapsulated within its own glass container 3 and, in use, the respective glass containers must be located at a precise point within the tube 1 and at the pre-required distance apart. Accordingly, considerable care is required in the manufacture of switch devices having a plurality of reed switches each of which is individually encapsulated. In Figure 2, there is illustrated one embodiment of a switch device made in accordance with the present invention. in accordance with the invention two reed switches 20 are located within a glass container 30 which is in turn located at the desired point within an outer tube 10 which forms part of the air bleeding device. Since the reed switches 2 are located within the glass container 3 during the manufacture of the switch itself then the desired spacing of the reed switches is assured. It is then a simple matter to fix the other container 30 inside the tube 10. The reed switches 20 are provided with respective leads 21, 22, 23, the lead 23 being common to one terminal of each switch. Modifications and improvements may be incorporated without departing from the scope of the invention, for example a larger number of reed switches may be provided. The container 30 may be provided with indexing means to cooperate with similar means on the inside of the tube 10 to ensure consistent location of the container 30 within the tube 10. CLAIMS

1. An electrical switch device comprising a plurality of electrical switches encapsulated within a single glass container.

2. A switch device as claimed in claim 1 wherein the switches are reed switches.

3. A switch device as claimed in any preceding claim wherein one terminal of each switch is connected to a common lead.

4. An electric switch device substantially as herein before described with reference to Figure 2 of the accompanying drawings.