WO2002056428A1

WO2002056428A1 - Adapter plug

Info

Publication number: WO2002056428A1
Application number: PCT/DK2002/000020
Authority: WO
Inventors: Tim Chung
Original assignee: Active Tools A/S
Priority date: 2001-01-11
Filing date: 2002-01-11
Publication date: 2002-07-18

Abstract

A standard jack-type plug for engaging sockets in different mobile electric installation, e.g. cars on the one hand and caravans on the other, is provided with a slidable jacket (7) surrounding a central body (1), the jacket provided with dimension and a board (9) at one end for acting as adapter, where the shifting between different configurations is performed by pushing the jacket (7) into two different positions. According to the invention, the jacket (7) is held fixed in the different positions by means of snap-action locks in the form of leaf-spring pawls (17, 18) and engaging apertures (16) in the jacket (7).

Description

Adapter Plug Background of the Invention

The present invention concerns an adapter plug for standard sockets in mobile electric installations, including caravans, boats and cars, and comprising an elongate body with a front end for engaging a socket and a rear end opposite hereto, the front end being provided with two sets of metallic terminals adapted for contacting conducting parts of the socket, wherein the first set of terminals are provided at the side of the plug and the second set consist of a central rod protruding axially at the front end, where the body is partly surrounded along its length with a jacket that may be displaced along the body between a first position closer to the front end of the body and a second position closer to the rear end of the body, where the end of the jacket closer to the front end is shaped as an adapter for use in differently shaped sockets.

Plugs for standard sockets in mobile electric installations, including caravans, boats and cars are made according to DIN standard, and the outer shape and dimension for fit with the sockets are therefore laid down in the standard. Sockets in cars are arranged in the cigarette lighters, whereas sockets in caravans and pleasure boats have another and lesser diameter. In order to shift between the different types of sockets, there are embodiments with adapters to be mounted at the front end when the plug is to be used in a car. DE utility model G 93 00 441 Ul discloses such a plug with a removable adapter; the disadvantage of this design being that the loose adapter can be lost when not in use. This drawback is relieved by the plug disclosed in US patent 5 482 468 having a slidable jacket acting as adapter arranged as indicated in the introduction above. The shifting is performed by sliding the jacket between the two posi- tions. However, this prior art does not indicate means for fixing the jacket in the positions, whereby there is a risk that the jacket slides during use, thus making engagement with the sockets insecure.

Summary of the Invention The peculiar feature of the invention is that the jacket may alternatively be fixed in the first and the second positions by means of at least one snap-action lock. The jacket and thereby the adapter may thereby be held fixed in either of the two positions. By using a snap-action lock, the jacket may be operated with very simple means which are also easy to provide in the body.

In a preferred embodiment of the invention, the snap-action lock includes a spring biased pawl provided between the jacket and the body, the pawl capable of engaging apertures in the jacket where the apertures are arranged for holding the jacket in the active and the inactive position, respectively.

For providing a low-cost embodiment of the pawl for large-scale production, the pawl is moulded as a part of the body, in that it is shaped as a leaf spring extending in the longitudinal direction and along the surface of the body, where a button is provided at a side of the spring facing away from the body for engaging the apertures in the jacket.

The Drawing A preferred embodiment of the invention will now be described with reference to the drawing, in which:

Fig. 1 shows a longitudinal section of a plug according to the invention with the adapter in a retracted, passive position, Fig. 2 shows the same as Fig. 1 , but where the plug is turned 90° about its longitudinal axis, Fig. 3 shows the plug of Fig. 2 with the adapter in a forward, active position, Fig. 4 shows the plug of Fig. 3 with the upper half removed and with the jacket sectioned, and Fig. 5 shows the plug of Fig. 3 turned 90° about the longitudinal axis and partly in section.

Description of Preferred Embodiment

The plug according to the invention is designed to be used in applications with differ- ent sockets, in the example described below for 12 V installations in pleasure crafts and caravans on the one hand and in cars on the other hand, both according to DIN standard. The plug has an approximately cylindrical moulded plastic body 1 consisting of two symmetrical parts which are assembled along a dividing plane 2 in a way known per se and held together with a screw 3. A first set of electrical terminals 4 of metal are situated at opposite sides of the plug while the other terminal of metal for the other terminal consisting of a pointed rod 5 is located at the front end 6, or insertion end, of the plug.

A pair of electric wires 10 are, as shown on Fig. 4, passed through the rear end of the plug for connection with each their terminal 4 and 5 in a way known per se.

As shown on Fig. 4, the terminal 5 is in contact with one end of a fuse 11 which again is in contact with an internal terminal 12 which in a way known per se may be a spring for keeping the fuse 11 in contact against the terminal 5. The fuse 11 is loosely suspended in a tubular housing 13 which is a part of the structure of the body 1. A nut or collar 14 keeps the terminal 5 in place as a flange on the terminal 5 engages the collar 14. The connection between collar 14 and body 1 is releasable; in the shown embodi- ment a threaded connection is preferred.

When the fuse 11 has melted and is to be exchanged with another, the collar 14 is loosened, and terminal 5 is removed, after which the fuse may be poured out and a new may be fitted.

A jacket 7 of moulded plastic surrounds part of the central part of the body 1. The jacket 7 is slidable in the longitudinal direction of the plug and has slits 8 for accommodating two of the first terminals 4 during the sliding. The jacket 7 is shaped with a bead 9 close to the front end 6 of the plug, and with dimensions according to the stan- dard for 12 N plugs and sockets in the above mentioned applications.

In order to keep the jacket 7 in a passive and an active position as shown on Figs. 1-2 an 3-5, respectively, the jacket 7 has apertures 16 that may engage one or two snap- action pawls 17. As shown, there are two apertures 16 for each pawl 17, an aperture for each position in which the jacket may assume. In the shown example, two pawls at opposite sides of the plug are used, thus providing easy operation with thumb and forefinger when the pawls 17 are pressed in for releasing the jacket 7. In the embodiment, the pawls 17 are made integrated with the body 1 as springs 18 are formed by slotting the sides of the body, the springs 18 keeping the pawls 17 biased against their locking position, i.e. where they 17 are engaging an aperture 16.

When the plug according to the invention is applied in pleasure crafts and caravans, the passive, or second, position in Figs. 1 and 2, where the jacket 7 is pulled away from the front end of the plug, is used. If there is changed to cigarette lighter sockets in cars, the pawls 17 are pushed in and the jacket 7 is moved towards the front end until the pawls 17 are locking it 7 in the active, or first, position shown on Figs. 3-5.

Claims

1. An adapter plug for standard sockets in mobile electric installations, including caravans, boats and cars, and comprising an elongate body (1) with a front end for engag- ing a socket and a rear end opposite hereto, the front end being provided with two sets of metallic terminals (4,5) adapted for contacting conducting parts of the socket, wherein the first set of terminals (4) are provided at the side of the plug and the second set consist of a central rod (5) protruding axially at the front end, where the body (1) is partly surrounded along its length with a jacket (7) that may be displaced along the body (1) between a first position closer to the front end of the body and a second position closer to the rear end of the body, where the end of the jacket (7) closer to the front end is shaped as an adapter for use in differently shaped sockets, characterised in that the jacket (7) may alternatively be fixed in the first and the second positions by means of at least one snap-action lock (16,17,18).

2. An adapter plug according to claim 1, characterised in that the snap-action lock includes a spring biased pawl (17,18) disposed between the jacket (7) and the body (1), the pawl capable of engaging apertures (16) in the jacket where the apertures (16) are arranged for holding the jacket (7) in active and the inactive position, respectively.

3. An adapter plug according to claim 2, characterised in that the pawl (17,18) is moulded as a part of the body, in that it is shaped as a leaf spring (18) extending in the longitudinal direction and along the surface of the body (1), where a button (17) is provided at a side of the spring (18) facing away from the body for engaging the aper- tures (16) in the jacket (7).

4. An adapter plug according to any preceding claim, characterised that there are two snap-action locks disposed at opposite sides of the plug.