GB2269271A

GB2269271A - Connections to battery housing

Info

Publication number: GB2269271A
Application number: GB9216278A
Authority: GB
Inventors: Ian David Haffenden; David Bernard Sugden; Richard David Wenham
Original assignee: Landis and Gyr Communications UK Ltd
Current assignee: Landis and Gyr Communications UK Ltd
Priority date: 1992-07-30
Filing date: 1992-07-30
Publication date: 1994-02-02
Anticipated expiration: 2012-07-30
Also published as: GB9216278D0; GB2269271B

Abstract

A system for housing a battery includes an insulating housing (1) to receive the battery and a plug (7) which is electrically connected to the battery. A socket (6) receives the plug thereby connecting the battery to a circuit The housing has an opening (3) through which the battery is accessible to the user. When the plug (7) is located in the socket (6), the plug (7) blocks access through the opening (3) to the battery. This makes it necessary to remove the plug (7) and thereby disconnect the battery from the circuit before handling the battery. <IMAGE>

Description

BATTERY HOUSING The present invention relates to a system for housing a battery, and in particular to an arrangement suitable for a battery used to power a circuit which may under some conditions be subject to dangerously high voltages.

While some telephone handsets may take their power directly from the telephone line, it is also common, particulary with payphones, to use a battery to power circuits within the phone. Periodically, it is necessary for the user to have access to the battery in order to replace it. Although the voltages produced by the battery itself are so low as to present no danger, high voltages may sometimes be present in the circuit to which the battery is connected. This might be the case, for example, if power lines have fallen across the telephone line to which the telephone is connected. The body of the battery is uninsulated, and there is therefore a risk of the user receiving a serious electric shock if he touches the battery while it is connected to the circuit.

According to the present invention, there is provided a system comprising an insulating housing arranged to receive a battery, a plug which in use is electrically connected to the battery, and a socket arranged to receive the plug, thereby connecting the battery to a circuit, in which the housing has an opening through which in use the battery is accessible to the user and the plug and socket are configured so that when the plug is located in the socket the plug blocks access through the opening to the battery, thereby requiring the user to remove the plug and disconnect the battery from the circuit before handling the battery.

The present inventors have devised a simple but effective arrangement for ensuring that the battery is safely insulated from the user while it is connected to the circuit, while still enabling the user to access the battery when required. This is done by locating the battery in an insulating housing with an access opening.

The connection between the battery and the circuit is formed using a plug and socket which are located with respect to the opening so that they block the opening.

This forces the user to break the connection between the battery and the circuit before the battery can be handled.

While the system of the present invention is particularly suitable for use with a battery-powered payphone, it may also be used in other electrical products.

Preferably, the housing is an elongate housing having the access opening formed at one end thereof.

Preferably the plug is connected by a flexible lead to a connector which, in use, is attached to the terminal of the battery, the connector being located within the housing and the flexible lead passing through the other end of the housing.

A further feature contributing to the safety of the arrangement adopted in the present invention, is the use of a relatively short connecting lead between the plug and a conventional connector for the battery which makes a pushon fit with the terminals on an end face of the battery.

This lead passes through the end of the housing opposite the access opening. In the preferred example, a narrow aperture is provided in the housing for this purpose. In use therefore, as the plug is inserted in the socket, the connector and the battery are drawn towards the end of the housing away from the opening. This serves to locate the battery at a predetermined position in the housing once the plug is connected. At the same time, the battery is immediately freed, facilitating access, once the plug is removed from the socket, making it easy to draw the battery out.

An example of a system in accordance with the present invention will now be described in detail with reference to the accompany drawings, in which: Figure 1 is a perspective view; Figure 2 is a partially sectional side elevation of the battery fitted in the housing; and Figure 3 is a partially sectional side elevation showing the battery removed from the house.

A housing 1 of rectangular cross-section is formed integrally with a laminar equipment tray 2 from a plastics material, in the present example ABS. The housing is dimensioned to be slightly larger than the battery it is intended to hold, in the present example a PP3 battery.

One end 3 of the housing 1 is open. A socket 4 is formed in the tray 2 immediately in front of the opening 3. The socket 4 comprises an aperture 5 and immediately below the aperture a connector 6 of conventional construction. In use, a corresponding plug 7 is located in the socket. The plug 7 is dimensioned so that when it is located in the socket 4 it blocks off the greater part of the opening 3.

As shown in Figure 1, the dimensions of the opening in the housing are such that the clearances from the connector top and side to the housing are 11 mm and 9.1 mm respectively. This obstructs access from a test probe or finger. The design as shown provides creepage and clearance dimensions meeting or bettering the requirements of 1.6 mm and 1 mm respectively laid down in BS6301 for secondary circuits with nominal supply voltages of 150V.

The plug 7 is connected by a lead 8 to a conventional terminal connector 9. The lead passes through an aperture 10 formed in the end wall 11 of the housing opposite the opening 3. The lead is of a length such that when the connector 9 is fitted to the battery as shown in Figure 2, the lead makes a tight fit around the housing so that the battery is held adjacent the end wall 11.

In the present example the housing forms part of a payphone and the connector 6 is mounted on a PCB forming part of the circuits for that phone. These circuits are connected to the telephone line. Under some conditions, high voltages may be present on the telephone line and hence in the circuits. The housing 1 is constructed so that with the battery located as shown in Figure 2, the battery casing cannot be touched by the user but when the user needs to handle the battery, for example to change it, the battery has first to be disconnected from the circuit by the removal of the plug from the socket. This allows the battery to be withdrawn through the opening with the lead being drawn through the aperture and the housing as shown in Figure 3.

Claims

1. A system comprising an insulating housing arranged to receive a battery; a plug which, in use, is electrically connected to the battery; and a socket arranged to receive the plug, thereby connecting the battery to a circuit, in which the housing has an opening through which, in use, the battery is accessible to the user and the plug and socket are configured so that when the plug is located in the socket the plug blocks access through the opening to the battery, thereby requiring the user to remove the plug and disconnect the battery from the circuit before handling the battery.

2. A system according to claim 1, in which the housing is an elongate housing having the access opening formed at one end thereof.

3. A system according to claim 2, in which the plug is connected by a flexible lead to a connector which, in use, is attached to the terminal of the battery, the connector being located within the housing and the flexible lead passing through the other end of the housing.

4. A system according to claim 3, in which the lead is sufficiently short that the battery, in use, when connected to the connector is located towards the end of the housing away from the opening.

5. A system according to claim 3 or 4, in which the housing includes a channel positioned on an exterior surface of the housing and running longitudinally, in use the channel locating the lead extending between the connector and the plug.

6. A system substantially as described with respect to the accompanying drawings.

7. A telephone including a system according to any one of the preceding claims.