GB2052138A

GB2052138A - Safety plug for accumulator batteries

Info

Publication number: GB2052138A
Application number: GB8019275A
Authority: GB
Original assignee: SAMPELLEGRINI A
Current assignee: SAMPELLEGRINI A
Priority date: 1979-06-20
Filing date: 1980-06-12
Publication date: 1981-01-21
Also published as: DE8015541U1; BE883880A; FR2459558A3; IT7921893V0; FR2459558B3; IT7921893U1

Abstract

A safety plug for an accumulator comprises a porous disc (7) which prevents the passage of flame. <IMAGE>

Description

SPECIFICATION Safety plug for accumulator batteries The present invention relates to an improved safety plug for accumulator batteries, apt to allow the venting of gases developing from the battery elements, but preventing at the same time any possible explosion of such gases within said elements.

As known, it may frequently happen to cause explosions of the accumulator batteries as a result of the lighting up - due to sparks or other accidental combustion sources - of the gases developing from the battery elements, in that the flame which is not dangerous outside the battery can, by penetrating inside the elements without finding any obstacles actually cause the explosion.

The object of the present invention is to prevent these drawbacks by supplying a plug for accumulator batteries which, while freeing the battery from the gases developing inside its elements - as is essential for the proper working of the battery itself - is apt to prevent the flames from penetrating inside each element. This is obtained thanks to the fact that said plug comprises, interposed along the the exhaust path of the gases developing from the element to which the plug is applied, a porous disc which is permeable to said gases, but which is apt to prevent the passage of the flame. Said disc may appropriately be made of porous plastic material or of porous ceramic material.

To improve even further the characteristics of the plug according to the invention, when the same is of the type meant to be applied by pressure into the holes of the battery element, it is preferable to make it with an oval section and with the wall being less thick in its parts corresponding to the widest diameter of said section.

The invention will now be described in further detail with reference to the accompanying drawing, which shows various preferred embodiments thereof and in which: Fig. 1 is an axial section view of a safety plug according to the invention, to be applied by pressure; Fig. 2 is a view from the bottom of the plug of figure 1; Fig. 3 is a side view of the pressure cap for the plug of figures 1 and 2, figure 3a being an inner view of the same cap, and figures 3b and 3c being two sections respectively along the lines AA and SB of figure 3a; Fig. 4 is a partial axial section view of a plug similar to that of figures 1 and 2, but associated to a plug strip; and Fig. 5 is a side view, partially in axial section, of a plug similar to that of figures 1 and 2, but of the type to be applied by screwing.

With reference to the drawing, the pressure plug of figures 1 and 2 comprises a plug body 1 having a partly cylindrical and partly frustoconical wall, the bottom 2 of which has a deeply recessed part 3 and the top of which ends into a wide open seat 4. Openings 5 are provided at the bottom 2, on the periphery of its recessed part, and openings 6 are provided at the top of said recessed part, to form a labryinth preventing the outflow of liquid from the element to which the plug is applied to the top part of the plug itself.

According to the invention, a porous disc 7 is welded or otherwise firmly fixed to the seat 4 of the body 1, said disc 7 being made either of synthetic plastic material or of ceramic material.

The porous disc 7 is permeable to the gases developed by the liquid of the element to which the plug is applied, such gases being thus apt to escape from the plug through openings 4' of the seat 4, without finding any resistance in the disc 7. On the other hand, the same disc 7 prevents in a very efficient way the inlet into the plug, and thus into the battery element to which the plug is applied, of flames or sparks, thereby avoiding all possibility of explosion of the batteries in the event of any flames or sparks being present, for accidental reasons, in the seat housing such batteries.

The plug of figures 1 and 2 is closed, above the disc 7, by a cap 8 shown in further detail in figures 3 to 3c. This cap can be applied by pressure, by being forced into the yielding lip 4" of the seat 4 of the plug. The cap 8 is also formed of plastic material and it has on the inner side a plurality of radial ribs 9 departing from a central core 10, so as to divide into sectors the space existing between the cap 8 and the disc 7: this allows a rapid and full escape of the gases developed in the battery, through passages 11 communicating with the openings 4', thereby avoiding all conditions which may favour explosion, even between the cap and the disc.

Figure 4 shows a different embodiment of the plug of figures 1 to 3, designed for use in association with a plug strip (not shown), into which it is inserted thanks to the square shape of the cap 12 of the plug, simply resting thereon, which replaces the previously described cap 8 and is similar thereto.

Figure 5 shows the embodiment of the plug according to the invention to be applied by screwing. For this purpose, the side wall of the plug body 1 comprises a screw-thread 13, while the cap 8 forms part of a wider upper body 14 of the plug, being provided at the periphery with a knurl 1 5.

In the embodiment of figure 5, the wall of the plug body 1 is of uniform thickness and of cylindrical shape. Whereas, in the other embodiments with pressure engagement, the plug bodies - of cylindrical-frustoconical shape - have an oval cross-section with the wall being less thick in correspondence of its parts adjacent to the widest diameter of said section: in this way, the pressure insertion and the permanence of the plug into the seat are made easier and safer.

1. A plug for accumulator batteries, apt to allow the venting of the gases developing from the battery elements and to prevent any possible

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Safety plug for accumulator batteries The present invention relates to an improved safety plug for accumulator batteries, apt to allow the venting of gases developing from the battery elements, but preventing at the same time any possible explosion of such gases within said elements. As known, it may frequently happen to cause explosions of the accumulator batteries as a result of the lighting up - due to sparks or other accidental combustion sources - of the gases developing from the battery elements, in that the flame which is not dangerous outside the battery can, by penetrating inside the elements without finding any obstacles actually cause the explosion. The object of the present invention is to prevent these drawbacks by supplying a plug for accumulator batteries which, while freeing the battery from the gases developing inside its elements - as is essential for the proper working of the battery itself - is apt to prevent the flames from penetrating inside each element. This is obtained thanks to the fact that said plug comprises, interposed along the the exhaust path of the gases developing from the element to which the plug is applied, a porous disc which is permeable to said gases, but which is apt to prevent the passage of the flame. Said disc may appropriately be made of porous plastic material or of porous ceramic material. To improve even further the characteristics of the plug according to the invention, when the same is of the type meant to be applied by pressure into the holes of the battery element, it is preferable to make it with an oval section and with the wall being less thick in its parts corresponding to the widest diameter of said section. The invention will now be described in further detail with reference to the accompanying drawing, which shows various preferred embodiments thereof and in which: Fig. 1 is an axial section view of a safety plug according to the invention, to be applied by pressure; Fig. 2 is a view from the bottom of the plug of figure 1; Fig. 3 is a side view of the pressure cap for the plug of figures 1 and 2, figure 3a being an inner view of the same cap, and figures 3b and 3c being two sections respectively along the lines AA and SB of figure 3a; Fig. 4 is a partial axial section view of a plug similar to that of figures 1 and 2, but associated to a plug strip; and Fig. 5 is a side view, partially in axial section, of a plug similar to that of figures 1 and 2, but of the type to be applied by screwing. With reference to the drawing, the pressure plug of figures 1 and 2 comprises a plug body 1 having a partly cylindrical and partly frustoconical wall, the bottom 2 of which has a deeply recessed part 3 and the top of which ends into a wide open seat 4. Openings 5 are provided at the bottom 2, on the periphery of its recessed part, and openings 6 are provided at the top of said recessed part, to form a labryinth preventing the outflow of liquid from the element to which the plug is applied to the top part of the plug itself. According to the invention, a porous disc 7 is welded or otherwise firmly fixed to the seat 4 of the body 1, said disc 7 being made either of synthetic plastic material or of ceramic material. The porous disc 7 is permeable to the gases developed by the liquid of the element to which the plug is applied, such gases being thus apt to escape from the plug through openings 4' of the seat 4, without finding any resistance in the disc 7. On the other hand, the same disc 7 prevents in a very efficient way the inlet into the plug, and thus into the battery element to which the plug is applied, of flames or sparks, thereby avoiding all possibility of explosion of the batteries in the event of any flames or sparks being present, for accidental reasons, in the seat housing such batteries. The plug of figures 1 and 2 is closed, above the disc 7, by a cap 8 shown in further detail in figures 3 to 3c. This cap can be applied by pressure, by being forced into the yielding lip 4" of the seat 4 of the plug. The cap 8 is also formed of plastic material and it has on the inner side a plurality of radial ribs 9 departing from a central core 10, so as to divide into sectors the space existing between the cap 8 and the disc 7: this allows a rapid and full escape of the gases developed in the battery, through passages 11 communicating with the openings 4', thereby avoiding all conditions which may favour explosion, even between the cap and the disc. Figure 4 shows a different embodiment of the plug of figures 1 to 3, designed for use in association with a plug strip (not shown), into which it is inserted thanks to the square shape of the cap 12 of the plug, simply resting thereon, which replaces the previously described cap 8 and is similar thereto. Figure 5 shows the embodiment of the plug according to the invention to be applied by screwing. For this purpose, the side wall of the plug body 1 comprises a screw-thread 13, while the cap 8 forms part of a wider upper body 14 of the plug, being provided at the periphery with a knurl 1 5. In the embodiment of figure 5, the wall of the plug body 1 is of uniform thickness and of cylindrical shape. Whereas, in the other embodiments with pressure engagement, the plug bodies - of cylindrical-frustoconical shape - have an oval cross-section with the wall being less thick in correspondence of its parts adjacent to the widest diameter of said section: in this way, the pressure insertion and the permanence of the plug into the seat are made easier and safer. CLAIMS

1. A plug for accumulator batteries, apt to allow the venting of the gases developing from the battery elements and to prevent any possible explosion, characterized in that, along the exhaust path of the gases developing from the element to which the plug is applied, there is interposed a porous disc being permeable to said gases, but being apt to prevent the passage of the flame.

2. A plug as in claim 1, wherein said porous disc is made of porous synthetic plastic material.

3. A plug as in claim 1, wherein said porous disc is made of porous ceramic material.

4. A plug as in claims 1 to 3, wherein said porous disc is welded or otherwise firmly fixed to an upper seat of the plug, which comprises a lip for retaining a closing cap which delimits exhaust areas of the gases crossing said disc towards the periphery of the plug.

5. A plug as in claim 4, wherein said cap comprises a plurality of radial ribs for delimiting said exhaust areas.

6. A plug as in claims 1 to 5, applied by pressure, wherein the section of the plug body is oyal and the wall parts of said body are of reduced thickness in correspondence of the widest diameter of said section.

7. A plug as in claims 1 to 6, wherein the plug is associated to a plug strip (into which it is inserted with its seat portion) together with other plugs.

8. A plug as in claims 1 to 5, applied by screwing.

9. A plug, substantially as hereinbefore ,described with reference to the accompanying drawing.

10. Any novel feature or combination of features herein described.