Safety valve having sealed reset means

Claim 2

In an automatic shut-off valve of the type wherein the valve is automatically closed by the movement of a pallet into engagement with a valve seat in response to presence of an unsafe condition, apparatus to re-set the pallet after the valve has operated comprising: a. a guide member having a hole axially aligned with the center of the valve seat and positioned on the side of said valve seat opposite the pallet; b. a rod movable in said guide member between a first and second position, said first position being spaced from the plane of the valve seat and said second position passing through said plane to force said pallet away from said seat; c. plunger means permanently attached to the end of said rod closest to said seat, said plunger means having a diameter less than the hole in said seat but greater than the diameter of said rod; d. an element slidable on said rod placed adjacent said plunger means and having sealing means inserted on the circumference of its end closest said seat, said closest end being of a diameter greater than the hole in said seat; e. a first spring encircling said rod between said element and said guide member; f. a second spring encircling said rod on the opposite side of said guide Member from said first spring, and being stronger than said first spring; g. stop means affixed to the other end of said rod; and h. sealing means around said rod to prevent leakage between said rod and said guide member, said sealing means comprising a spring shoulder between said guide and said second spring, said shoulder being hollowed on the end which contacts said guide member and containing in the inner portion of said hollow an oiled felt washer and in the outer portion of said hollow a silicone washer, said silicone washer having an outer diameter greater than the size of said hollow and an inner diameter smaller than the size of said rod thereby causing sealing on its inner and outer surface.

Claim 3

The invention according to claim 1 and further including a hollow in the end of said element opposite said end having said sealing means, said hollow containing in its inner portion an oiled felt washer and in its outer portion a silicone washer having an outer diameter greater than said hollow and an inner diameter less than that of said rod and a solid spring shoulder of a diameter at least equal to that of said element placed between said element and said first spring.

Claim 4

An automatic shut-off valve which closes in response to an unsafe condition and remains closed until manually reset after the condition has been restored to normal, said valve comprising, in combination: a. a valve body having inlet and outlet openings with a valve seat interposed therebetween; b. a pallet movable from a normally open position to a closed position with respect to said seat to block flow therethrough in response to the presence of an unsafe condition; c. a rod mounted for movement from an initial position axially through said valve body and having a first end portion extending outside said valve body for manual engagement to effect said movement and a second end portion positioned to engage said pallet when the latter is in its closed position upon said movement of said rod and to move said pallet back to its open position; d. an element slidably mounted on said rod adjacent said second end portion and having a peripheral portion movable into sealing engagement with said valve seat, said element encircling said rod with a clearance therebetween; e. a first spring biasing said element toward said second end portion of said rod, said element, second end portion, valve seat and pallet being so relatively arranged that movement of said rod against the bias of said first spring moves said element into sealing engagement of said peripheral portion with said valve seat, and continued movement of said rod against the bias of said first spring moves said second end portion into engagement with said pallet; g. a second spring biasing said rod toward said initial position; and h. sealing means between said rod and said element allowing relative movement therebetween while preventing leakage of gas through the space providing clearance between said rod and element, said sealing means comprising a lubricated felt washer and a plastic washer each encircling and contacting the entire periphery of said rod, and each being disposed in a hollow in said element, at least said plastic washer having an outer diameter greater than that of said hollow to tightly engage the latter around its entire periphery.

Claim 5

An automatic shut-off valve which closes in response to an unsafe condition and remains closed until manually reset after the condition has been restored to normal, said valve comprising, in combination: a. a valve body having inlet and outlet openings with a valve seat interposed therebetween; b. a pallet movable from a normally open position to a closed position with respect to said seat to block flow therethrough in response to the presence of an unsafe condition; c. a rod mounted for movement from an initial position axially through said valve body and having a first end portion extending outside said valve body for manual engagement to effect said movement and a second end portion positioned to engage said pallet when the latter is in its closed position upon said movement of said rod and to move said pallet back to its open position; d. an element slidably mounted on said rod adjacent said second end portion and having a peripheral portion movable into sealing engagement with said valve seat, said element encircling said rod with a clearance therebetween; e. a first spring biasing said element toward said second end portion of said rod, said element, second end portion, valve seat and pallet being so relatively arranged that movement of said rod against the bias of said first spring moves said element into sealing engagement of said peripheral portion with said valve seat, and continued movement of said rod against the bias of said first spring moves said second end portion into engagement with said pallet; g. a second spring biasing said rod toward said initial position; and h. sealing means between said rod and said element allowing relative movement therebetween while preventing leakage of gas through the space providing clearance between said rod and element, said sealing means comprising a lubricated felt washer and a plastic washer each encircling and contacting the entire periphery of said rod, and each being disposed in a hollow in said element, at least said plastic washer having an outer diameter greater than that of said hollow to tightly engage the latter around its entire periphery.

Claim 6

The invention according to claim 3 wherein the combined thickness of said felt and plastic washers is greater than the depth of said hollow in said element.

Claim 7

The invention according to claim 3 and further including guide means having an opening through which said rod slidably passes between said first and second springs, and second sealing means comprising a lubricated felt washer and a plastic washer each encircling and contacting the entire periphery of said rod and each disposed in a hollow in a spring shoulder disposed between said first spring and said guide means.

Claim 8

The invention according to claim 5 and further including third sealing means comprising a lubricated felt washer and a plastic washer each encircling and contacting the entire periphery of said rod and each disposed in a hollow in a spring shoulder disposed between one end of said second spring and said guide means.