Two-way vent valve for batteries

Aug. 17, 1965

G. B. ELLIS 3,201,284

TWO-WAY VENT VALVE FOR BATTERIES

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^TTOMZY

United States Patent Office

3,201,284

Patented Aug. 17, 1965

3,201,284

TWO-WAY VENT VALVE FOR BATTERIES Grenville B. Ellis, Eastliampton, Mass., assignor to GouldNational Batteries, Inc., a corporation of Delaware Filed Nov. 5,1962, Ser. No. 235,398

Claims. (CI. 136—178)

This invention relates to a pressure release device and particularly to a two-way pressure vent valve for use with containers in which a gas is to be retained under predetermined maximum and minimum pressures as in storage battery containers of the normally closed type. A subatmospheric pressure or low vacuum may develop under some conditions in such containers and under other conditions dangerously high pressure may build up and require the release of gas to the atmosphere. Dangerously low internal pressure may be caused by chemical reaction of the gases with the active material in the container or when the cell or battery is used under extremely low temperature conditions, requiring the opening of the valve to admit air to the container.

It is an object of this invention to provide a novel, simple and reliable two-way vent valve which will permit gas to flow either from the interior of the cell container or into the interior of a normally sealed container when a predetermined pressure differential exists between the gas within the container and the outside atmospheric pressure, thus preventing damage to the container that might otherwise result from excessively high or low internal pressures.

Another object is to provide a vent device which will allow the flow of gas either from or into a container when the pressure therein varies a predetermined limit from atmospheric pressure, while insuring the closing and sealing of the container when the pressure differential has been alleviated.

The invention also includes certain other novel features of construction which will be more fully pointed out in the following specification and claims.

In the drawing:

FIGURE 1 is a plan view of a battery cell provided with one of my improved two-way vent valves;

FIG. 2 is a side elevational view showing the vent valve in place on a battery container;

FIG. 3 is a central vertical sectional view showing a preferred form of my two-way vent valve separate from the container;

FIG. 4 is a horizontal sectional view taken on the line 4—4 of FIG. 3, and

FIG. 5 is a side elevational view showing the tubular body member of my improved valve.

Referring to FIGS. 1 and 2, a battery container subject to variable internal gas pressure is indicated generally at 6, the cover of the container is indicated at 7, positive and negative terminals are indicated at 8 and 8a respectively, and one of my improved pressure vent valves is indicated generally at 9. As shown in FIGS. 3 and 5, the valve 9 has a vertically elongated- tubular body 10 formed with an externally threaded lower end portion 11 adapted to fit in a threaded opening in the cell cover 7. An upper end portion 12 of the valve body may be formed with a cross slot 13 in its upper end surface to facilitate turning the body to and from its assembled position in the threaded opening in the cover.

An annular groove indicated generally by the numeral 14 is formed in the outer periphery of the body 10, being defined by spaced parallel annular shoulders 15 and 16 and adjacent cylindrical surfaces 17 and 18. An enlargement 19 of the annular groove 14 is disposed radially inward therefrom and is connected by radial passages 20 to a vertically elongated passage 21 extending to the lower end of the tubular body 10.

Sealing rings 22 and 23 are confined under lateral compression and longitudinal tension in the groove 14 between the shoulders 15 and 16. Each of these rings has an annular valve seat surface 24 which is normally 5 in closed, continuous contact with a similar seat surface of the other ring. Beveled outer and inner surfaces 22a on the ring 22 converge toward the seat surface 24 and similar beveled surfaces 23α are formed on the ring 23 to converge toward the seat 24.

The rings 22 and 23 are formed from suitably flexible, elastic material, such as a rubber or rubber-like material of selected durometer hardness to permit the separation of the valve seat surfaces 24 for venting the interior of the container upon the development of prede15 termined gas pressure differentials at the interior and exterior sides of the sealing rings. The rings 22 and 23 may be formed, for example, from neoprene having durometer hardness within the range of 35 to 60. For use with a simple, one-piece valve body these sealing 20 rings should have sufficient elasticity so that they may be expanded and sprung into place in the groove 14 defined by the annular shoulders 15 and 16 and cylindrical surfaces 17 -and 18. The annular enlargement 19 disposed radially inwardly from the rings 22 and 23 per25 mits the beveled sections of the rings to be sprung inward for the passage of air into the container when a subatmospheric pressure of predetermined value develops within the container.

The connection between the tubular body 10 and bat30 tery cell cover 7 may be sealed by the use of a gasket 25 (FIG. 3) between an annular shoulder on the body 10 above the threaded lower end portion 11 for contact with an annular surface of the cover 7.

By suitable selection of the composition, shape and 35 dimensions of the rings 22 and 23, a predetermined maximum upper limit may be established for the pressure in a battery cell. Upon the development of a high pressure, approaching the safe upper limit in the container, for example, portions of the rings 22 and 23 ad40 jacent to -the contact seat surfaces 24 are separated and sprung outward to relieve the container of excess gas. Subsequently, should the pressure in the container be reduced to a predetermined safe low limit of vacuum, air will be admitted between the sealing rings 22 and 45 23 so that the gas pressure within the battery container is maintained at all times within safe limits.

Thus in operation when for any reason, a substantial, predetermined pressure differential develops between the gas pressure inside the container and the outside atmos⁵⁰ pheric pressure, the beveled section of the seal rings 22 and 23 will be deflected from its normal position in the direction of the resultant pressure acting on these rings. If the pressure differential becomes great enough, the seal at the annular seat surface 24 will be broken, and gas ⁵⁵ will flow from the higher pressure side of the container until the excessive pressure differential has been eliminated. It will also be understood that by selection of the thickness and shape of the coacting seal rings a pressure vent valve in conformance with my invention may be adapted to vent when any predetermined pressure differential is reached. Modifications may be made in the shape of sealing rings described herein without departing from my inventive concept.