Fluid handling – Line condition change responsive valves – Direct response valves
Reexamination Certificate
1999-10-21
2001-03-13
Huson, Gregory L. (Department: 3753)
Fluid handling
Line condition change responsive valves
Direct response valves
C137S543210, C137S014000
Reexamination Certificate
active
06199583
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to a valve device for use in pressurized flexible hoses to automatically prevent forceful escape of air or other gas from the hose if it becomes disconnected from the primary conduit and then to allow slow release of this gas to gradually return the pressure in the hose to atmospheric pressure. Thus, the noise and whipping action usually associated with sudden loss of pressure in gas hoses is eliminated.
2. Description of the Related Art
The prior art is aware of pneumatic systems which are made up of a source of pressurized gas, usually air, in combination with a primary gas conduit which is detachably connected to a flexible hose by means of a quick-disconnect valve. The downstream or distal end of the flexible hose is connected to an air-powered tool. In such systems of the prior art, disconnection of the flexible hose from the primary gas conduit causes a loud noise which can be harmful to hearing. Also, this rapid decrease in pressure can lead to whipping or lashing of the end of the flexible hose that has become disconnected from the primary conduit. The present invention is designed to eliminate these hazards existing in the prior art systems.
The prior art is also aware of valves which allow the passage of pressurized gas in a distal direction and prevent the sudden backflow of pressurized gas upon elimination of the pressure upstream of the valves. Thus, Great Britain Pat. No. 6738 to Burgess et al published Mar. 30, 1909 discloses a stem fitted with a spring and a plunger having a bypass hole therein to prevent the sudden loss of steam pressure but to allow a gradual reduction in pressure. The spring may be omitted and the device may be operated by gravity. The valve device of this patent is required to be approximately twice the size of the steam conduit and requires the presence of an elongated stem in order to maintain the plunger in proper alignment. U.S. Pat. No. 821,859 to Clegg also teaches a valve which allows air flow in a distal direction. This valve contains a plunger which abuts with a tapered seat. The plunger contains a port running the length of the plunger. When air pressure and the spring force the plunger distally, air flows freely. Upon loss of air pressure upstream of the valve, the plunger is forced against the tapered seat to eliminate sudden loss of pressure downstream of the valve, Air flowing through the port allows a gradual return of the downstream pressure to atmospheric pressure. This valve requires a long axial stem to maintain the alignment of the plunger and, as a consequence, the valve must be bulky. This is suitable for railroad braking systems disclosed in the patent but would not be amenable for the operation of pneumatic powered tools where lightness of weight and smallness of size are essential. Neither of these prior art references addresses the safety problems caused by loud noise and whipping ends of hoses when the hoses suddenly become disconnected from a pressure source.
SUMMARY OF THE INVENTION
The present invention has for its purpose the elimination of the unsafe results in the form of loud noise and whipping of the hose caused by the sudden reduction of air or other gaseous pressure in a system containing a source of pressurized gas, a primary gas conduit, at least one flexible hose connected to the primary gas conduit by means of a quick-disconnect valve, and a gas-powered device. The loud noise and whipping is caused by the pressure in the hose being released suddenly. This improved safety is brought about by the use of a unique safety gas valve specifically designed for this system. The valve, which contains a wall, may be a permanent attachment to a flexible hose or it may be a separate unit capable of being attached to a flexible hose. The valve contains a positioning washer, a plunger removably or permanently connected to, or unified with, the positioning washer, and a seat, preferably tapered, in the wall,. The plunger contains a proximal surface which fits snugly against the seat to form a distal compartment and a proximal compartment in the valve device. There is a discharge orifice running through the plunger or the wall of the casing. Under normal operating conditions, with gas passing distally through the valve, the plunger is held away from the valve seat by the resilient means and the pressure created by the flow of gas. When the flexible hose becomes disconnected from the air supply, the pressure upstream of the valve decreases suddenly, and the downstream pressure forces the valve shut to prevent the loud noise and whipping common in the prior art systems. Gas which is downstream from the valve then passes slowly through the discharge orifice to equalize the pressure upstream and downstream from the valve. During routine use of the system, air flow through the valve is not always constant, but can fluctuate widely. This can cause unnecessary motion of the plunger assembly inside the valve body thereby shortening the useful life of the device. In order to prevent this condition, the valve may contain a support piece connected to the wall and a resilient device distal to the support piece. This resilient device helps to stabilize the plunger assembly and thus prevent premature deterioration of the device.
REFERENCES:
patent: 821859 (1906-05-01), Clegg
patent: 2676613 (1954-04-01), Baxter
patent: 3146792 (1964-09-01), Donnelly et al.
patent: 3194255 (1965-07-01), Flaton et al.
patent: 3275145 (1966-09-01), Jacobellis
patent: 3548868 (1970-12-01), Mullaney, III
patent: 3794077 (1974-02-01), Fanshier
patent: 4080988 (1978-03-01), Robertson
patent: 4328827 (1982-05-01), Enjolras
patent: 4474189 (1984-10-01), Brown
patent: 4637430 (1987-01-01), Scheffel et al.
patent: 4693270 (1987-09-01), Yaindl
patent: 5924438 (1999-07-01), Cimminelli et al.
patent: 207640 (1958-05-01), None
Huff Richard L.
Huson Gregory L.
LandOfFree
Safety gas valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Safety gas valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Safety gas valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2487110