Shut off device

Claim 3

A device as in claim 1 which comprises orifice means through which the water flows in passing through said device and means for increasing the cross-sectional area of said orifice means in response to increase in the rate of flow through said device whereby to maintain a substantially constant pressure drop acorss said orifice means despite the increase in said rate of flow.

Claim 4

A device as in claim 2 in which the movement of said movable means is resisted by dash pot means including a water-containing chamber having a restricted opening through which the water of said chamber is forced out into the stream of water flowing through said device.

Claim 5

A device as in claim 1 in which said range of rates extends upward from (a) a rate corresponding to a slow leak in said hose to (b) a rate corresponding to the normal demand of said machine, said range being wide enough to include an at least fifteenfold change in rate, said movable means moving to said shut off position in response to the continuation of said pressure drop for an extended period of time which is more than sufficient to fill said machine at said rate b.

Claim 6

A device as in claim 1, adapted for use with a feedline having a water supply pressure of about 20 to 70 psig, said wide range of rates extending over at least the range from 0.2 gallon per minute to 3 gallons per minute, the construction and arrangement being such that when the rate of flow through the device increases beyond a given rate the magnitude of said pressure drop does increase substantially on further increase in flow rate, thus decreasing said elapsed time for said movement to said shut off position, said shutting off means having an original position, said device including means for returning said shutting off means to said original position if said flow ceases before said shutting off means reaches said shutting off position.

Claim 7

A fluid flow control device having an inlet for fluid and an outlet for said fluid and means for shutting off the flow of fluid to said outlet, said flow control device having orifice means through which the fluid flows in passing from said inlet to said outlet whereby there is a pressurE drop across said orifice means, said shutting off means including timing means and being responsive to the magnitude of said pressure drop and to the duration of said pressure drop, and means for increasing the cross sectional area of said orifice means in response to increases in the rate at which said fluid flows through said orifice means so as to decrease the differences in the pressure drop across said orifice means resulting from differences in said rate of flow.

Claim 8

A fluid flow control device having an inlet for fluid and an outlet for said fluid and means for shutting off the flow of fluid to said outlet, said flow control device having orifice means through which the fluid flows in passing from said inlet to said outlet whereby there is a pressurE drop across said orifice means, said shutting off means including timing means and being responsive to the magnitude of said pressure drop and to the duration of said pressure drop, and means for increasing the cross sectional area of said orifice means in response to increases in the rate at which said fluid flows through said orifice means so as to decrease the differences in the pressure drop across said orifice means resulting from differences in said rate of flow.

Claim 9

A fluid flow control device as in claim 6 comprising housing means through which the fluid passes, valve means in the path of the flow of the fluid and movable in the direction of fluid flow, there being annular orifices for the flow of said fluid past said valve means, and means biasing the valve means in a direction to reduce the size of said annular orifices and opposite to the direction of fluid flow.

Claim 10

A device as in claim 7 in which said orifices are annular; said valve means comprises a valve seat, a poppet having an orifice-defining head adapted to engage said seat, and an orifice-defining shoulder on said poppet downstream of said head; said shutting off means comprises a timing piston adapted to move from an initial position to a shut off position; said timing piston has an upstream end which is acted upon by the pressure upstream of said orifices and a downstream end which is acted upon by the lower pressure downstream of said orifices; said timing piston has a shut off valve head adapted to engage a second valve seat to shut off said flow when the piston has moved to the shut off position; said device has a fluid-containing chamber connected to a restricted passageway for the flow of fluid from said chamber; the construction and arrangement is such that the movement of said timing piston towards the shut off position exerts pressure on the fluid in said chamber whereby the rate of said movement of said piston is controlled by the rate of fluid flow through said restricted passageway; said device also comprises means for automatically restoring said timing piston to its initial position when the fluid flow through said device is shut off downstream of said device and the pressure downstream of said orifices approaches the pressure upstream of said orifices; and said restoring means comprises a spring acting on said timing piston and acting to expand said chamber, means defining a fluid passage for the return of fluid to said chamber, and a check valve in said fluid passage permitting said return of fluid and preventing flow of fluid through said passage in the opposite direction.

Claim 11

A device as in claim 8 including manually operable means for moving said timing piston, when in shut off position, for a distance equal to a minor portion of the overall travel of said piston, whereby operation of said manually operable means, after any path for fluid flow downstream from said device has been closed subsequent to the shutting off of flow in said device by the action of said piston, brings said piston to a position from which it is then restored to its intial position by the action of said restoring means.

Claim 12

A device as in claim 9 in which said device is of generally cylindrical configuration; the poppet and the timing piston are each tubular and movable rectilinearly in said device along the general direction of fluid fluid through the device; the piston has a head movable in a second, narower, annular bore of said poppet; and said restricted passageway is formed by the clearance between said stem and said second bore.

Claim 13

A device as in claim 8 in which said poppet moves in response to fluid flow through said device, to a position which provides greater orifice sizes when the rate of flow through the device is greater.

Claim 14

A device as in claim 8 in which the construction and arrangement is such that when the rate of flow through the device increases beyond a given level the size of the orifices does not increase substantially whereby the magnitude of said pressure drop does increase sUbstantially on further increase in flow rate, thus increasing the speed at which the piston travels to said shut off position.

Claim 15

A device as in claim 8 including means for limiting the movement of said poppet whereby the size of the orifices does not increase when the rate of flow through the device increases beyond a givenlevel so that the magnitude of said pressure drop does increase substantially on further increase in flow rate, thus increasing the speed at which the piston travels to said shut off position.

Claim 16

A fluid flow control device having an inlet for fluid and an outlet for said fluid and means for shutting off the flow of fluid to said outlet, said flow control device having means through which the fluid flows in passing from said inlet to said outlet whereby there is a pressure drop across said means, said shutting off means including timing means and being responsive to the magnitude of said pressure drop and to the duration of said pressure drop, the construction and arrangement of said first means being such that the curve made by plotting the magnitude of said pressure drop (as ordinate) against the flow rate rises for a short initial region then substantially levels off over a longer intermediate region and then rises again rapidly.

Claim 17

A fluid flow control device having an inlet for fluid and an outlet for said fluid and means for shutting off the flow of fluid to said outlet, said flow control device having means through which the fluid flows in passing from said inlet to said outlet whereby there is a pressure drop across said means, said shutting off means including timing means and being responsive to the magnitude of said pressure drop and to the duration of said pressure drop, the construction and arrangement of said first means being such that the curve made by plotting the magnitude of said pressure drop (as ordinate) against the flow rate rises for a short initial region then substantially levels off over a longer intermediate region and then rises again rapidly.

Claim 18

A device as in claim 4 in which said movable means is constructed and arranged to move toward said shut off position during said extended period and to move in the opposite direction on the cessation of said flow prior to its reaching said shut off position.

Claim 19

A device as in claim 6 in which said shutting off means responds to shut off said flow after said pressure drop has continued for an extended period of time and said means for increasing said area is constructed so that the pressure drop across said orifice means is substantially constant over a range of flow rates in which there is an at least fifteenfold change in flow rate so that said extended period for the flow rate at the low end of said range is similar to said extended period for the flow rate at the high end of said range.