GB2184207A - Safety valve - Google Patents

Abstract

A safety valve, especially for a gas tank, comprises cut-off means 2 which can be manually overridden. Preferably the valve also includes safety relief means 3 and exhaust means 4. A ball 21 of the cut-off means 2 is moved by differential pressure to block a passage 15 should a leak cause excess flow. The ball 21 can be lifted from its seat by depressing a button of the exhaust means 4 so as to push down a control rod 45 which, in turn, engages the ball 21. The button is provided with bars (422 Figure 2) which engage in L-shaped grooves in a knob of the exhaust means 4 and can be rotated in the grooves to hold the ball 21 away from its seat. <IMAGE>

Description

SPECIFICATION Safety valve This invention relates to a safety valve, and especiallytooneofgastank.

The damages of gas leakage are known everywhere. whereverthere is a gas tank, there are damages of gas leakage. Most of the damages become serious because the valve of gas tank cannot be closed quickly and that always makes an explosion. However, for most oftime, people is too frightened or unconscious to close the valve. That is whythe inventordevelopsthis invention.

The present invention isto improve the conventional valve in orderthatwhen the gas is leaking, the valve would be closed automatically.

Therefore, the valve according to the present invention would be safer than the conventional one.

Furthermore, becausethe high pressuregastank is very popular and useful everywhere, the test of each tank is very important. The usual test procedure isto pump air intothetestedtankto investigate whetherthe tested tank leaks or not and the pressure it can sustain. However, before the gas isto be pumped into the tank having been tested already, the test air pumped into the tested tank must be released first. The releasing ofgreatquantityofairfrom the tankwill makethe passage blocked as described hereinafter. The present invention also provide a means to restorethevalve having been automatically closed.

According to the above-mentioned disadvantage, the present invention provide a gas valve structure which will be auto-closed by the leakage of gas and be re-opened by pressing a button down to have the plastic ball away from the orifice of gays passage and recover the passage.

It is the primary object ofthe present invention to provide a safety valve to prevent any serious leakage of gas out of said valve. When the gas leaks out of said valve, the gas passage of said valve will be closed because of great pressure difference.

It is another object ofthe present invention to provide a safety valve having unlocking device.

When the passage of the valve is closed, the unlocking device will recoverthe passage to let the gasoutastheuser'swill.

Figure lisa perspective view of a preferred embodiment of the present invention; Figure2 is a fragment view of a preferred embodimentshown in Figure 1; and Figures 3 and 4 are cross-sectional views of a preferred embodiment shown in Figure 1 with respect two manual open and closed situation respectively.

Please referto Figures 1 and 2, the present invention comprises a body 1, a cut-off means 2, a safety means 3, and a exhaust means 4. Since the safety means 3 is some prior art of high pressure release structure and there would be no more statement to describe this part. The otherthree parts would be described as follows.

Said body 1 hasfourchannels 11,12,13and 14 inside it and four corresponding threaded seats 110, 120,130and 140.The bottom channel 11 can receive said cut-off means 2 and its threaded seat 110 can fix thevalve on the gastank (notshown). The lower sideways channel 13 along with its threaded seat 130 can receive and engagewith said safety means3.

The upper sideways channel 12 whose threaded seat 120 engages with gas hose union (not shown) act as a gas outlet. The top channel 14togetherwith its threaded seat 140 can receive and engagewith said exhaust means 4. There are also two passages 15 and 16 inside said body 1. One passage, 15, extends fromthe bottom channel 11 tothe uppersideways channel 12to allow gas to pass through. The other passage, 16, communicates the bottom channel 11 and the lower sideways channel 13.

Said cut-off means 2 comprises a plastic ball 21 and a helical spring 22. The lower end of said helical spring 22 with largerdiametercan be fixed on the inside cylindrical wall 111. The spring 22 can support said plastic ball 21 in a place nearthe passage 15.

When much gas leaks outquickly,the great flow of gas and pressure difference make the plastic ball 21 buoy u p, then, stopped by and blockthe orifice of said passage 15. It cuts the gas flow off. Obviously, it is not necessary to make the ball 21 of plastic material. The only requirements ofthe ball 21 are that it can buoy up at or beyond a certain gas flow rate, that means at or beyond a certain pressure difference, and it is large enough to block the passage 15.

Said exhaust means 4 comprises a slender control bar46, a piston 45, a engaging member44, a nut 43, a knob 41, a spring 47 and a button 42. The piston 45 has a central hole 452 through itto allow the slender control bar 45 to penetrate and a seal 453 fixing on its outsidesurfaceto prevent the gas from leaking through the clearance between the piston 45 and the topchannel l4andanotch45lwithagroove4ss inside itto engage with the engaging end 443 ofthe engaging member 44.The engaging member44 with an engaging end 443 on the bottom, a thread 442 on the middle of outside surface and a block end 441 on the top on engage with the piston 45 bythe engaging end 443, engagewitha nut43bythethread 442 and insert into the channel 414 underthe knob 41. There is still a hole penetrating through the engaging member44concentricallytoallowthe slender control bar46to penetrate it. The nut 43 with male-thread 432 on the lower end and female-thread 431 on the upperend can engagewith thethread 140 ofthetopchannel 1 4 of the body 1 bythelower male-thread 432 and engage with thethread 442 of the engaging member44 bythefemale-thread 431.

The knob 41 with a circularseat412 on the annular recess ofthe upper plane and a channel 414beneath the lower plane can receive the block end 441 ofthe engaging member 44 bythe channel 414 and receive a spring 47 and a button 42 by the seat 412. There is also two shall L-grooves41 1 on the side of the annual recess which can receivethetwosmall bars 422 extending from the button 42. There is a threaded hole 421 underthetop of the button 42 to engagewiththethreaded end 461 of the control bar 46.The control bar46can insert into and penetrate through the piston 452, the engaging member 44, the nut 42 and a hole 413 formed on the knob 41 and engage with the threaded hole 421 ofthe button 42.

On the lower part ofthe control bar46,there is a seal 462 fixed on the grooves 463 formed in suitable position to prevent gas leakage when penetrating through and engaging with the piston 45.

The operation ofthe present invention would be described as follows. Please refer to Figures 3 and 4.

lfthevalve is opened and there is any leakage of gas outside the valve, the pressure drop accross the valve would become greatersothatthe ball 21 will buoy up by the action ofthe pressure difference to blockthe orifice ofthe passage 15 (as shown on the dash line of Figure 3) and because ofthe pressure of the gas insidethe tank, the ball would be maintained there. Then the gasflow is cut off and makes no more leakage. If the userwantsto re-open the valve and operate it normally, he can depress the button 42 which, in turn, depress the slender control bar 46 to drop the ball 21. Then the gas flows out again. If the leakagestill exists,thegreatpressuredropwould buoy up the ball 21 and blockthe passage 15 again.

If the gas is to be released out quickly as the user's will, the great pressure drop would buoy up the ball 21 similarly. Underthis situation, the usercan depress and, then, rotate the button 42 along the L-groove 41 1,thenthe button would not rise again becausethesmall bars 422 are kept in the horizontal partofL-groove4ll and thatkeepsthe button 42 from rising. The control bar46 can keep the ball 21 from blocking the passage 15 then, and the gas continues flowing outquicklywithoutanytrouble.

According to the above description, the present invention with the design of L-grooves 411 ofthe knob 41 and two small bars 422 ofthe button 42 and the ball 21 can prevent gas leakage and operate conveniently. That makes the user safer.

Claims (4)

1. Asafetyvalvecomprising: a body having four channels inside it and four corresponding threaded seats, the bottom channel of said body receiving a cut-off means and its threaded seatfixing said valve on any gas source, the lower sideways channel along with its threaded seat receiving and engaging with a safety means, the upperchanneltogetherwith its thread acting as gas outlet,thetopchanneltogetherwith itsthreaded seat receiving and engaging with a exhaust means, said body still having two passages inside it, one extending from said bottom channel to the upper sideways channel to allowgasto passthrough,the othercommunicatesthebottom channel and the lower sideways channel to releave pressurized gas when the pressure of gas is too high;; a cut-off means including a ball and a helical spring, the helical spring with its lower end fixed on the interiorofsaid bottom channel keeping the ball in a place near the orifice ofthe passage extending from the bottom channel to the upper sideways channel in orderthatthe ball can buoy upto blockthe passagewhenthe pressure drop is larger;; an exhaust means including a slender control bar, a piston, aturning knob, a spring and a button,the piston with a central hole penetrating its radial centre and a seal fixing on its outside cylindrical surface engaging with a slender control bar at the centre and placed at the bottom of the top channel, said piston also having a notch on the top together with a groove inside itto engage with the engaging end of an engaging member, an engaging memberwith an engaging end on the bottom, a thread on the middle of outside surface and a block end on the top engaging with the piston by the engaging end and with a nut by theth read and inserting into the channel beneath the turning knob, said engaging member also having a central holeto allowthe slender control barto penetrate through itself, the nutwith male-thread on the lower end and female-thread on the upper end engaging with the thread ofthe top channel by the lower male-thread and with thethread of the engaging memberbythe female-thread,theturning knob with a circular seat on the annular recess of its upper surface and a channel beneath the lower surface receiving the block end of the engaging member by the channel and receiving a spring and a button by the circular seat, said turning knob also having a hole located concentrically to allowthe control bar to penetrate, the annular recess oftheturning knob having two L-grooves on its side to receive two small bar extending from the button, said button having a threaded holeunderittoengagewiththethreaded end of the slender control bar after the control bar penetrating through said piston, engaging member, nutand the knob; and characterized in thatthetwo small bars extending from the button can engage with the L-grooves on the side of the annular recess, and when keptatthe lower horizontal partsofthe L-grooves nottosprung back, can depress the slender control barwhich in turn, drop the ball and keep itawayfrom the orifice and allowthe gasto flowoutfora long while.

2. ASafetyValveincluding meansfor automatically closing avalve in responsetoafluid leakandmeansformanuallyoverridingthe automatic closing means.

3. ASafetyValveincluding meansfor automatically closing the valve in responseto a fluid flowthrough the valve.

4. A Safety Valve substantially as hereinbefore described, with reference to the accompanying drawings.