Inertially triggered fluid flow control device

A device for controlling fluid flow wherein a movable ball at a central location on a concave surface of a support prevents upward movement of an actuating element, such as a valve stem to prevent a specific function, such as the closure of a valve, until the ball moves laterally along the concave surface. A spring biases the element upwardly but the weight of the ball is greater than the bias force of the spring. When the ball moves laterally, the element moves upwardly through the concave surface and projects above it to prevent return of the ball to the central position on the concave surface until the stem is again forced downwardly, such as by a pivotal lever engaging a projection on the element to shift the latter. Means is provided in the device for adjusting the bias force of the spring.

This invention relates to improvements in safety devices for control 
purposes and, more particularly, to a device for immediately performing a 
specific function, such as interrupting a fluid flow, in response to the 
occurrence of an unusual terrestial event, such as an earthquake. 
BACKGROUND OF THE INVENTION 
It is well-known that earthquake or other violent earth tremors can cause 
damage and loss of life due to fires which are started when natural gas 
pipes are broken or ruptured. Over the years, attempts have been made to 
provide a safety cut-off valve for controlling flow of natural gas during 
calamities. For the most part, these attempts have not been successful in 
providing a safety device of simple and rugged construction and one of 
relatively few parts. A need has, therefore, arisen for an improved safety 
control device having these characteristics and suitable for use in 
protecting a home or other structure during an earthquake from fire and 
other hazards. 
SUMMARY OF THE INVENTION 
The present invention is directed to a control device which satisfies the 
foregoing need wherein the device has a ball for holding a first of a pair 
of relatively shiftable elements in a fixed position with respect to the 
second element so long as the device is not subject to vibrations or 
shocks of the type caused by earthquakes or other terrestial events. The 
ball, when subjected to such vibrations or shocks, is movable out of an 
operative position permitting relative movement of the elements, causing a 
specific function to be performed, such as the closing of a fluid valve or 
the closing of an electrical switch. As hereinafter set forth, the control 
device of this invention will be described with respect to the control of 
a flow of fluid, such as natural gas. 
To this end, the device includes a housing formed of several parts joined 
together to enclose a valve and valve seat, with the valve having a stem 
extending into a passage in the base of a support for the ball itself. The 
support has a concave upper surface and a recess for centering the ball 
above the valve stem. The ball normally engages the upper end of the valve 
stem and the weight of the ball prevents upward movement of the stem and 
thereby closing of the valve even though the valve is biased upwardly by a 
spring coupled with the stem. When the ball moves laterally, the stem 
moves upwardly past the concave surface, whereupon the valve moves into 
closing relationship to the valve seat. The upper end of the valve stem 
remains above the concave surface, thereby preventing return of the ball 
until the valve stem is retracted, i.e., the valve is manually opened. 
This is accomplished by the use of a pivotal lever inside the housing for 
engaging a projection on the valve stem to retract it when a pushbutton is 
depressed from outside the housing. Means is also provided in the housing 
to adjust the bias force of the spring so that the device can be made as 
sensitive as is desired. 
The primary object of this invention is to provide an improved control 
device for use in performing a specific control function, such as the 
closure of a fluid valve, wherein the device is simple and rugged in 
construction, is easy to assemble and disassemble, and operates to hold a 
first element in an operative position relative to a second element so 
long as a ball is centered with respect to a concave surface above a 
spring biased stem coupled to one of the elements. 
Another object of this invention is to provide a control device of the type 
described, wherein the device is provided with a ball support mounted on 
spaced legs above a first element and the support is provided with means 
for shiftably mounting a second element so that, when a spring biases the 
second element upwardly, the second element will move relative to the 
first element to cause a specific function to be performed when the ball 
moves laterally, such as when vibrations or shocks are exerted on the 
device itself. 
Other objects of this invention will become apparent as the following 
specification progresses, reference being had to the accompanying drawings 
for an illustration of the invention.

The control device selected to illustrate the teachings of the present 
invention is one which is used to control the flow of a fluid, such as 
natural gas, through a flow line. The device is broadly denoted by the 
numeral 10 and includes a housing formed of a top member 12, a central 
tubular member 14, and a bottom member 16. Top member 12 has a neck 17 
provided with an opening 18 for connection with a pipe or tube. Bottom 
member 16 also has a neck 20 provided with an opening 22 for connection 
with a pipe or tube. Central member 14 is threaded at opposite ends 
thereof for threaded connection with the lower end of top member 12 and 
the upper end of bottom member 16. FIG. 3 shows the bottom member threaded 
with the central member. For purposes of illustration, the top, central 
and bottom members are made of metal; however, they can be of other 
materials, such as plastic, if desired, so long as they form a fluid-tight 
housing. 
Device 10 is provided with valve means 24 therein and a control ball 26 for 
holding the valve means in an open condition when the ball is centrally 
located within central member 14 as shown in FIG. 3. To this end, valve 
means 24 includes an annular valve seat element 28 provided with an outer 
periphery 30 which is disposed between a shoulder 32 on bottom member 16 
(FIG. 1) and a lower face 34 on central member 14 when these two members 
are connected together as shown in FIG. 3. In this way, element 28 is held 
in place against movement relative to the central and bottom members. 
Element 28 has a beveled, inner, peripheral surface 36 defining a valve 
seat for a valve member 38, the latter having a beveled outer surface 40 
(FIG. 1) provided with an O-ring 42 thereon for engaging beveled inner 
surface 36 of the valve seat element 28 to close valve means 24. FIGS. 1 
and 3 show valve member 38 in its open position. 
A valve stem 44 is rigidly connected to valve member 38 at the center 
thereof. Stem 44 passes upwardly through a collar 46 and is shiftable 
therethrough. Collar 46 has a number of spaced legs 48 radiating therefrom 
and connected at their outer ends to a ring 50, the latter resting on a 
number of adjustment screws 52 threadably mounted in valve seat element 
28. For purposes of illustration, there are four legs 48 as shown in FIG. 
2, the legs being sufficiently spaced apart to allow fluid to flow 
therebetween. While only two screws 52 are shown in FIG. 3, typically 
there will be three or possibly four such screws. If three screws are 
used, they will be spaced 120.degree. apart. Four such screws will be 
spaced 90.degree. apart. 
A circular support 54 has a number of spaced legs 56 secured thereto, each 
leg 56 being curved so that it extends outwardly and then downwardly from 
support 54 as shown in FIGS. 1 and 3. The lower end of each leg 56 has a 
lateral projection 58 which fits under the beveled surface 60 of central 
member 14 when the latter is threadably connected to the upper end of 
bottom member 16 to hold leg 56 in place. When so mounted, legs 56 
position support 54 in vertically spaced relationship above collar 46 as 
shown in FIG. 3. 
Support 54 has a concave upper surface 62 on which ball 26 is disposed. 
Further, support 54 has a countersunk recess 64 at the center of concave 
surface 62 to releasably retain ball 26 centrally located. This is 
achieved because the ball engages the angular upper edge defining the 
upper boundary of recess 64 as shown in FIG. 3. A slight lateral force is 
required to disengage the ball from engagement with this annular upper 
edge; whereas, without the edge, the ball would be only in rolling contact 
with concave upper surface 62 and would not easily remain centered. 
Support 54 is provided with a boss 66 having a passage 68 therethrough for 
receiving the upper end of valve stem 44 as shown in FIG. 3. Valve stem 44 
is shiftable in passage 68 and can extend upwardly of recess 64 and 
concave surface 62. 
Valve stem 44 has a disk-like projection 70 secured thereto below its upper 
end. A coil spring 72 normally under compression is disposed between the 
upper face of collar 46 and the lower face of annular projection 70. This 
causes valve stem 44 and thereby valve member 38 to be biased upwardly. 
However, the bias force of the spring is less than the weight of ball 26 
so that, when the ball is in place as shown in FIG. 3, it holds valve stem 
44 against upward movement; thus, valve member 38 is held in the open 
position shown in FIG. 3 in spaced relationship to valve seat element 28. 
A lever 74 (FIG. 3) is pivotally mounted by a pin 76 on a fitting 78 which 
is threaded into a hole 80 in the side of the housing. A spring 82 biases 
lever 74 in a clockwise sense when viewing FIG. 3 into the full line 
position, but the spring allows the lever to pivot to the dashed line 
position thereof to retract valve stem 44 when thumb or finger pressure is 
applied to a pushbutton 84 shiftably received within an opening 86 through 
the outer end wall 88 of fitting 78. The inner end of the pushbutton 
engages a projection 90 on lever 74 to move it in a counter-clockwise 
sense when viewing FIG. 3. An O-ring seal 92 near the inner end of the 
pushbutton normally engages the inner face of end wall 88 to seal the 
junction therebetween. 
In operation, control device 10 will be assembled with central member 14 
connected at its upper end to top member 12 and at its lower end to bottom 
member 16. Suitable pipes or tubes will be connected to top and bottom 
members 12 and 16 at openings 18 and 22, respectively, and ball 26 will be 
centrally located on concave surface 62 in the manner shown in FIG. 3. In 
this position, the ball holds valve stem 44 from rising due to the bias 
force of spring 72. In this condition, valve member 38 is spaced from 
beveled inner surface 36 and valve means 24 is in an open condition. Thus, 
a fluid such as natural gas can flow through device 10 inasmuch as the 
valve is open and the spacing of legs 48 and 56 permit fluid flow past 
collar 46 and support 54. The device will, of course, be mounted in the 
vertical position. 
If an earthquake or earth termor occurs, vibration will be transmitted to 
device 10 and will cause ball 26 to move laterally by rolling out of 
engagement with the annular upper edge defining the upper boundary of 
recess 64. When this occurs, coil spring 72 forces valve stem 44 upwardly, 
causing valve member 38 to move toward valve seat element 28 until O-ring 
42 engages beveled inner surface 36 closing the valve. The upper end of 
valve stem 44 projects above the concave surface 62; thus, any tendency of 
ball 26 to return to its central position shown in FIG. 3 is prevented. 
The upper end of valve stem 44 holds ball 26 at one side of recess 64, 
such as in the dashed line position of FIG. 3, and valve member 38 remains 
in the closed condition. The ball is still in recess 64 even though the 
ball is near the outer periphery of the recess. Thus, the ball will return 
to its full line position of FIG. 3 when valve stem 44 is retracted under 
the influence of lever 74 as pushbutton 84 is pressed inwardly. This will 
reset device 10. 
Device 10, therefore, provides a safety measure which, for instance, can be 
placed in a natural gas line leading to a residence. For instance, the 
device will be placed immediately downstream of a gas meter of a residence 
to prevent flow of natural gas to gas pipes under the residence which 
might become ruptured and cause a fire hazard. No such fire hazard will 
occur because the gas will be shut off before it reaches the residence. 
While device 10 has been described as a valve, it is not to be limited to 
this use. Device 10 can have other applications, if desired. For instance, 
it can be made to provide electrical switching action, such as the closing 
or opening of an electrical switch when the ball moves out of the full 
line position of FIG. 3. For instance, elements 28 and 38, instead of 
being a valve seat and a valve member, respectively, can be two elements 
of an electrical switch which is closed when the ball moves out of the 
full line position of FIG. 3. The device could also be made in the form of 
an electrical switch which opens when the ball moves out of the full line 
position. Thus, the device is suitable for use in a number of applications 
which require a pair of relatively shiftable actuating elements which 
perform a specific function when they move relative to each other.