GB2082734A - A Valve and a Vehicle Tyre Deflation Signalling Means Incorporating the Valve - Google Patents

Abstract

A valve for normally confining a gaseous fluid in a container, for example a vehicle tyre, comprises a tubular housing 1, a substantially annular valve seat 18 in the housing coaxial therewith, a valve member 16 in the housing biased by the gaseous fluid in the container into sealing engagement with the valve seat 18, piston means 25, 26 movably contained in the housing 1 in a region of the latter between the valve seat 18 and an open end 31 of the housing, and a seal 23 on the piston means operatively coactible with the housing proximate the open end 31 of the housing. The valve member 16 and the valve seat 18 constitute a first means for preventing escape of gaseous fluid from the container, and the piston means 25, 26 and the seal 23 constituting a secondary means for preventing escape of gaseous fluid from the container. <IMAGE>

Description

SPECIFICATION A Valve and a Vehicle Tyre Deflation Signalling System Incorporating the Valve This invention relates to a valve for normally confining a gaseous fluid in a container, for example a vehicle tyre, and for indicating a decline or diminution of the fluid in the container.

According to one aspect of the invention, a valve for normally confining a gaseous fluid in a container comprises a tubular housing, a substantially annular valve seat in the housing coaxial therewith, a valve poppet in the housing biased by the gaseous fluid in the container into sealing engagement with the valve seat, piston plunger means movably contained in said housing, an end of said plunger extending through an open end of said housing remote from said valve seat, and seal means on said plunger end operatively coactible with said housing proximate said open end, said valve poppet and said seat constituting a first seal to prevent gas escape from said container, said plunger end and seal means constituting a secondary gas escape prevention means.

According to another aspect of the invention, a valve for normally confining a gaseous fluid in a container comprises an elongate tubular housing, a substantially annular valve seat in the housing, coaxial therewith, and proximate an end of said tubular housing operatively connected to said container, a valve poppet in the housing biased by the gaseous fluid in the container into sealing engagement with the valve seat and constituting therewith primary seal means for prevention of escape of said gaseous fluid from said container, and a piston assembly movably contained in said tubular housing and disposed therein beyond said valve seat toward an opposite, open end of said tubular housing, said piston assembly being operable upon a decrease of the bias on said valve poppet to sealingly engage in said open end and constituting therewith secondary seal means for prevention of gaseous fluid escape from said container.

According to a still further aspect of the invention, a vehicle tyre deflation signalling system comprises a substantially cylindrical housing having an axial bore and adapted for securement to a tyre with one end of said bore in communication with the interior of the tyre, said housing presenting an annular valve seat facing toward said end of the bore, an annular shoulder facing toward said end more remote therefrom than said valve seat, and an annular sealing surface converging toward the opposite end of the bore more remote from the first end thereof than said shoulder, a valve poppet in the bore engageable with said annular seat and adapted to be biased thereagainst by fluid under pressure in the tyre, yiefding means disposed in the bore in engagement with said shoulder and said poppet biasing the poppet toward the tyre and away from said annular seat, a substantially cylindrical indicating unit disposed in the bore adapted to be projected beyond the end thereof remote trom the tyre upon release of gaseous fluid from the tyre by said poppet, resilient annular sealing means surrounding said indicating unit and engageable with said converging annular sealing surface to confine within the bore gaseous fluid released thereinto by movement of the poppet away from its seat under bias of said gaseous fluid under pressure in the tyre, and yielding means biasing the indicating unit in the bore in the direction to maintain said sealing means in engagement with said sealing surface.

This invention relates to a valve for normally confining a gaseous fluid in a container, for example a vehicle tyre, and for indicating a decline or diminution of the fluid in the container.

The signalling system of the present invention utilizes some of the underlying principles employed by apparatus as disclosed in U.S.

Letters Patents Nos. 3,717,845, 3,827,393 and 3,828,149. However, in the present invention, the gaseous fluid under pressure released from the container is utilized to actuate visual signalling means and only so much thereof as is essential for that purpose is permitted to escape from the container. When the signalling means has been actuated to display a signal indicating a diminution of pressure, further discharge of gaseous fluid from the con-tainer is prevented, thereby retaining the gaseous fluid in the container to the greatest extent possible under the circumstances.

Preferably, the apparatus of the invention is used as a composite replacement for standard known tyre valve structures, functionally incorporating the operational features thereof while additionally serving as a pressure loss indicator for the tyre.

The invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a side elevation of a typical vehicle wheel on which is mounted a pneumatic tyre having associated therewith apparatus embodying the present invention, Figure 2 is an enlarged axial sectional view, and partly in elevation, of the invention illustrating the mechanical elements thereof in relation to each other while fluid pressure in the tyre is at or above the desired pressure, but below which the signalling means will be actuated to indicate a lower than desired pressure in the tyre, Figure 3 is a corresponding view but showing the changed relationship of the components which occur upon a diminution of pressure in the tyre below a desired value, and Figure 4 is a corresponding view showing application of a tyre gauge, inflation hose fitting or the like utilised for determining the pressure in the tyre or reinflating it, respectively.

More specifically, the invention includes a hollow, substantially cylindrical housing generally designated 1, which is shown as attached on a vehicle wheel 2, on which is mounted a pneumatic tyre 3. The housing 1 is attached to the wheel 2 by insertion through a hole in the wheel rim, from which it projects inwardly toward the wheel axis and communicates with the interior of the tyre. Appropriate means including a gasket 4, and nut 5, threaded on the housing 1, ensure an air-tight connection between the exterior of the housing 1 and the wheel rim 2', about the hole through which the housing projects, a shoulder 6 on the housing 1 providing a seat for the gasket 4.

Internally, the housing bore is divided into two axially spaced chambers 12, 1 3 by a spacing washer 10 engaging and operatively connected with an annular shoulder 11 in the bore. Chamber 12, adjacent the wheel 2, contains pressure retaining valve elements normally effective for maintaining the fluid pressure in the tyre, while the chamber 13 contains signalling means which are actuated when the pressure in the tyre falls below a predetermined value.

The chamber 12, considered progressively in the direction away from the inner end of the housing which projects into and is in communication with the interior of the tyre 3, has an annular groove 14 in which is seated a resilient split retaining ring 1 5 which serves as retaining means for a valve member in the form of a circular poppet member 16, carrying an annular gasket 1 7 engageable with an annular valve seat 18 formed within the housing, and normally cooperative with the poppet member to prevent escape of air from the tyre. In a preferred embodiment, the upper surface of the poppet member can be cup shaped as a 16' to retain the gasket 1 7 more positively.

Interposed between the poppet 1 6 and the spacing washer 10 there is a calibrating compression spring 19, or other appropriate yielding means, bearing at one end upon the washer, and biasing the poppet member 1 6 toward the retaining ring 1 5. This spring has a strength selected in accordance with the pressure it is desired to maintain in the tyre, and functions to unseat and displace the poppet member 1 6 and gasket 1 7 from seat 18 when the pressure in the tyre, in reiation to external ambient pressure, falls below a predetermined selected value.The spring 1 9 and poppet member 1 6 thus constitute components of a differential-pressure-responsive valve operating to function as described.

The second chamber 1 3 contains the signalling means and actuating means therefor, being axially aligned in the housing bore with the valve containing chamber 12. Disposed within chamber 13, and movable therein axially with relation to the housing, and having an indicator head 20 normally projecting slightly beyond the adjacent end ofthe housing, is a low tyre pressure signalling piston 21, preferably distinctively coloured for ready visual recognition when projected to its extreme position (Figure 3).The piston carries, in appropriate annular grooves, resilient, preferably elastomeric upper and lower O-rings 23, 24. The grooves are intermediate axially spaced piston zones 25, 26 of progressively increasingdiameter from the head 20 to a spindle 27, which projects axially from the piston zone 26 into the chamber 12, as will hereinafter more fully appear.

The interior wall of chamber 13 proximate its upper end smoothly merges into a chamber 13' ot lesser diameter. The merging section is indicated at 29. The chamber 13' merges at shoulder 30 into an upper chamber-like outlet opening 31. The interior walls of the chambers are finished smoothly to ensure seal against intrusion of dust or other foreign matter at points where engaged by the O-rings 23, 24. The shoulder 30 provides an annular seat spaced axially inwardly from the opening 31, and when the piston 21 is projected outwardly of the housing, then O-ring 24 is brought into sealing engagement therewith.The wall of the chamber 13' axially inwardly of the seat 30 engages O-ring 24 in such a sealing relation as to inhibit free escape of air from the tyre during the projection of the piston caused by release of air from the tyre into the housing 1 upon unseating of poppet member 16.

The piston 21 is normally held in a nonprojected position (Figure 2) by a return spring 28 interposed between it and the spacing washer 10.

The chamber 13 is of somewhat enlarged diameter inwardly from chamber 13', which is normally engaged by O-ring 24, to afford a path for air escape or inlet when the indicator head 20 is depressed from its normal position, such as by application of a tyre gauge G, or the like, (Figure 4) at the end of housing 1, or to introduce air into the tyre in a known manner from a source of pressurised air.

As will be evident from the foregoing, the signalling means in accordance with the invention, as embodied in means for low pressure signalling in a pneumatic vehicle tyre, can replace known types of valve means, such as those normally provided to enable the tyre to be inflated, performs all the functions of the latter, and additionally providing low tyre pressure signalling means.

Under normal conditions (Figure 2), assuming the tyre 3 is properly inflated, the engagement of the O-ring 23 with its seat in the opening 31 at the end of the housing 1 excludes intrusion of foreign matter into the housing, while the internal pressure in the tyre holds the poppet member 16 and its gasket 17 against the valve seat 18 to prevent escape of air from the tyre.

However, on loss of pressure in the tyre for any reason, the pressure against poppet member 16 falls correspondingly and when it has fallen to a value less than that being asserted against the poppet member 1 6 by the compression spring 19, the latter unseats the poppet member (Figure 3), allowing pressure from within the tyre to be exerted against the piston zone 26. This air pressure, in addition to, or in combination with, the force of the return spring 28, causes the piston 21 to pop-up into the position of Figure 3.

Since the O-ring 24 engages the wall of chamber 13' in sealing relation, inhibiting escape of air from the interior of the housing, the pressure exerted against the piston zone 26, in conjunction with force of spring 28, forces it to move axially outward in chamber 13'. The piston is moved axially outwardly until O-ring 24, carried by the piston, engages seat 30 (Figure 3), preventing further escape of air and, at the same time, exposing for ready observation the preferably distinctively coloured zone 25 of the piston, thus conveying to an observer an indication that the tyre is under-inflated.

As noted, the piston carries a guide spindle 27 extending axially in the housing toward the poppet member16, and it is so positioned and of a length to engage the latter (Figure 4) to facilitate normal servicing of the associated tyre.

Thus, when, for example, it is desired to ascertain the pressure in the tyre, the usual valve depressing boss of a pressure gauge G may be applied to the exposed piston indicator head 20 to depress the latter against the bias of the return spring 28, and on engagement of the free end of spindle 27 with poppet member 16, unseating the latter and releasing air from the tyre to activate the pressure gauge G.

Similarly, any other appropriate tool may be applied to the piston indicator head either to release pressure from the tyre to deflate it, or to introduce air under predetermined pressure into the tyre to inflate the same as desired. It will be evident the spindle 27 may be secured either to the poppet member 16, or to the piston zone 26 although not to both.

In effect, what the present invention provides is very significant, and a very substantial contribution to the art. The apparatus provides a tyre low pressure visual indicator, which as a composite entity can replace a tyre valve as currently known and used. It is of a construction adaptable for mounting to a wheel rim by clamping mechanisms, or by a snap-in type resilient base as known in the art.

Fewer parts are required to provide both valving and low pressure indication, than of the type where the indicator is joined to a usually known valve body.

The structure provides improved servicing air flow due to the arrangement and cooperation of the plural chambers, and coaction with the 0rings on the piston.

The device has greatly improved safety in use.

This is due in large part to the use of two seals, a primary seal P, inside the rim, constituted by intercoacting engagement of the gasket 1 7 on the poppet means 16, with its seat 1 8 with normal tyre air pressure present, and a secondary or back-up seal, BU, constituted by the warning pin mechanism through interengagement between 0ring 24 and the shoulder 30 of the chamber 13' proximate the opening 31. The shoulder 30 is a sealing seatfor O-ring 24 under low tyre pressure conditions, when the signalling means has moved into the extended condition.

The invention is readily adaptable to on-board indication systems as well as the in place visual form as described. Positive movement of the indicator head to the extended position could readily be transmitted to a system of a known type for triggering an on-board system.

The invention is also susceptible of use in applications other than as tyre pressure indicators. It could be used in any situation where a fluid medium valving is needed, and the features as above delineated would be highly desirable.

Claims (18)

Claims

1. A valve for normally confining a gaseous fluid in a container comprising a tubular housing, a substantially annular valve seat in the housing coaxial therewith, a valve member in the housing biased by the gaseous fluid in the container into sealing engagement with the valve seat, piston means movably contained in said housing in a region of the latter between said valve seat and an open end of said housing remote from said valve seat, and seal means on said piston means operatively coactible with said housing proximate said open end of said housing, said valve member and said valve seat constituting a first means for preventing escape of gaseous fluid from said container, and said piston means and said seal means constituting a secondary means for preventing escape of gaseous fluid from said container.

2. A valve according to claim 1, in which said piston means comprises a plunger having an end extending through the open end of said housing, said seal means being on said plunger.

3. A valve according to claim 1, in which said valve seat is proximate an end of said tubular housing operativelv connected to said container.

4. A valve according to claim 3, in which said piston assembly is operable upon a decrease of the bias on said valve member to engage sealingly in said open end of the housing.

5. A valve according to claim 3 or 4, comprising first spring means in said housing operatively engaged with said valve member and operable upon a decrease of pressure of the gaseous fluid in the container to overcome bias of the valve member by the gaseous fluid in the container to disengage said valve member from said valve seat, whereupon gaseous fluid under pressure will engage a portion of said piston means and move the same towards said open end of said housing and thereby operatively activate said secondary means for preventing escape of gaseous fluid from the container.

6. A valve according to claim 5, in which said spring means comprises a compression spring having a strength sufficient to move said valve member upon decrease of pressure of the gaseous fluid in said container below a predetermined value.

7. A valve according to claim 6, comprising a spacing washer disposed within said tubular housing intermediate the ends thereof, an end of said compression spring opposite an end thereof engageable with said valve member being operatively engageable with said spacing washer.

8. A valve according to claim 7 comprising a return spring in said tubular housing disposed intermediate said spacing washer and said piston means, said return spring being operable to return said piston means to a closed sealing engagement with said open end following an operative depression of said piston means with respect to said open end, for the purpose of gauging gaseous fluid pressure in said container, and for venting or adding to the gaseous fluid in said container.

9. A valve according to claim 8, in which said tubular housing has internal chambers therein of decreasing diameter from said spacing washer to said open end, the smaller diameter chamber terminating proximate to said open end and including an annular seat disposed therebetween, and said piston means includes a low pressure indicator head extendable through said open end, a signalling piston axially spaced therebelow, an annular groove between said indicator head and said signalling piston, and an O-ring seal in said groove, said O-ring being sealingly engageable in said open end with said piston means in retracted position wherein said signalling piston is contained within the smaller diameter chamber, said O-ring preventing entrance of contaminants into said tubular housing under normal operating pressures of gaseous fluid in said container.

1 0. A valve according to claim 9, in which said piston means includes a further piston spaced from said signalling piston, an annular groove between said further piston and said signalling piston, and a further O-ring seal in said latter groove, said further O-ring being engageable with a valve seat formed by the merging area between said smaller internal chamber and said open end and constituting said secondary means for preventing escape of gaseous fluid from said container.

11. A valve according to claim 10, comprising a guide spindle connected to said further piston and extending within said tubular housing, through said return spring, said spacing washer and into said compression spring, said guide spindle being operable to contact said valve member upon depression of said piston means to disengage the valve member from its seat and create an air flow passage through said tubular housing from said container to said open end thereof, said return spring being operatively engageable between said further piston and said spacing washer in the depressed position of said piston means.

12. A valve according to claim 9 or 10, in which the internal diameter of said smaller chamber and the exterior dimensions of said further O-ring are substantially equal, whereby said further O-ring is in slidable sealing engagement with said smaller chamber upon movement of said further O-ring therealong.

13. A valve according to any of the preceding claims, said valve constituting a vehicle tyre deflation signalling system, said valve being operatively attached to a tyre rim of a vehicle wheel, the lowermost end of said tubular housing extending through the rim and the bottom thereof being in open communication with the interior ot a said vehicle tyre, the first means for preventing escape of gaseous fluid being disposed within the tyre, the upper portion of the housing extending outwardly above the rim and containing the secondary means for preventing escape of gaseous fluid.

1 4. A vehicle tyre deflation signalling system comprising a substantially cylindrical housing having an axial bore and adapted for securement to a tyre with one end of said bore in communication with the interior of the tyre, said housing presenting an annular valve seat facing toward said end of the bore, an annular shoulder facing toward said end more remote therefrom than said valve seat and an annular sealing surface converging toward the opposite end of the bore more remote from the first end thereof than said shoulder, a valve poppet in the bore engageable with said annular seat and adapted to be biased thereagainst by fluid under pressure in the tyre, yielding means disposed in the bore in engagement with said shoulder and said poppet biasing the poppet toward the tyre and away from said annular seat, a substantially cylindrical indicating unit diposed in the bore adapted to be projected beyond the end thereof remote from the tyre upon release of gaseous fluid from the tyre by said poppet, resilient annular sealing means surrounding said indicating unit and engageable with said converging annular sealing surface to confine within the bore gaseous fluid released thereinto by movement of the poppet away from its seat under bias of said gaseous fluid under pressure in the tyre, and yielding means biasing the indicating unit in the bore in the direction to maintain said sealing means in engagement with said sealing surface.

1 5. A signalling system according to claim 14, in which a spindle is carried by said indicating unit extending therefrom axially in the housing toward the poppet and engageable therewith to displace the poppet from its seat.

1 6. A signalling system according to claim 14, in which a spindle is interposed between the indicating unit and the poppet and is movable axially in the housing to unseat the poppet in response to axial movement of said unit toward the poppet.

17. A composite valve and visual fluid pressure loss indicator device for a container having a fluid medium under pressure therein, said device including a housing having a bore therethrough, said bore terminating in open ends, a first of said open ends being operatively and openly engageable with the interior of said container, said bore being formed as a plurality of interconnecting chambers of decreased diameter from said first open end toward a second said open end, movable closing and sealing means in said bore, a poppet chamber at said first said end in communication with said bore, said sealing means including a spring biased closing poppet member operatively contained in said poppet chamber, and engageable with an end of said bore to close and seal said bore against fluid passage therethrough with a predetermined pressure in said container, and constituting a first sealing closure, said movable means further including piston means in said bore, said piston means mounting an O-ring thereon, one said bore chamber proximate said first open end, having a restricted outlet opening and constituting, in conjunction with said O-ring, a second sealing closure operable upon a decrease of fluid pressure in said container to release the spring biasing of said poppet member and permit movement of said movable means to a closure sealing position with an interengageable seat proximate said second said open end.

18. A composite V Ave as claimed in claim 17, said container comprising a vehicle tyre, a rim mounting said tyre, said rim having an opening therethrough, the lower end of said housing extending through said opening into the interior of said tyre, said housing being operably secured to said rim, the means comprising said first sealing closure being disposed interiorally of said tyre and the upper portion of said housing extending above said rim and said second sealing closure being disposed above said rim, said movable means being extendable through said second said open end of said housing at said predetermined pressure and constituting a visual indicator extending above said housing.

1 9. A valve constructed and arranged substantially as herein described with reference to, and as illustrated in, the accompanying drawing.