US3111078A - Blast actuated ventilator valve - Google Patents

Description

Nov. 19, 1963 R. A. BRECKENRIDGE 3,111,078

BLAST ACTUATED VENTILATOR VALVE Filed Dec. 14, 1961 E G Y. H m E RR N mm R 4 NK 0 .3 mm w NR 1 w 57 2 R W 9 0 2 G 6 w n a s ;& 6 2 M 4M24 United States Patent O 3,111,078 BLAST ACTUATED VENTILATGR VALVE Robert A. Breckenridge, 437 N. M t., Oxnard, Calif. Filed Dec. 14, 1361, Ser. No. 159,469 1 Claim. (Cl. 98-419) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates generally to the ventilation of underground personnel shelters for use in the vicinity of possible nuclear bomb attacks and specifically to a ventilating closure which may be actuated by the bomb blast itself.

One of the most important considerations in the de sign of underground shelters for use in the protection of personnel from nuclear attacks is adequate ventilation. Normall, such ventilation may be provided by one or more ventilation pipes or ducts leading from the shelter to the surface of the ground above. In the event of the explosion of an atomic bomb or other nuclear device within effective range of the shelters, some provision must be made to immediately seal-off the ventilation duct leading to such shelter. Conversely, when the worst effects of the bomb have passed on over, the sealing-off or closure device should automatically open the ventilation duct for its intended purpose.

Other types of blast valves have been previously developed for such purposes. Such valves, however, have usually been connected with the upper exposed end of the ventilation duct and have thus been subject to initial blast damage. Also, such blast valves have generally been secondarily actuated by mechanical or electrical means triggered by a primary means operable as a function of the pressure of the blast wave or as a function of the intense light produced by the initial explosion. Such methods have been found too complex with decreased reliability in proportion to increased complexity. Furthermore, such prior valves have been one-shot devices. After each blast, they required re-cocking, recharging (in the case of valves operated by small explosive charges), re-opening, or otherwise the attention of trained personnel with the additional hazard of the exposing of such personnel to radioactive fallout.

The principal object of my invention, therefore, is to provide a blast actuated ventilator valve that is simply constructed and positively operated by the blast wave from the explosion of a nuclear device.

Another object of my invention is to provide a blast actuated closure for a ventilator duct which is continu ously repeatable in action without the necessity of recharging or recocking or other mechanical or electrical manipulation after each blast.

A further object of my invention is to provide a blast actuated ventilator valve which establishes a positive seal in a ventilation duct for protective shelters and is capable of continuous, automatic action in preventing the ingress of blast waves regardless of duration and frequency.

Other objects and advantages of this invention will be appreciated in conjunction with the following detailed description and accompanying drawings wherein:

FIGURE 1 is a partially cross-sectional elevation of an underground shelter showing the ventilation duct attached to one end thereof;

FIG. 2 is a partial sectional side elevation of the blast closure structure;

FIG. 3 is a cross-sectional front elevation of the blast closure structure taken on the line 33 of FIG. 2; and

3,1 1 1,078 Patented Nov. 19, 1963 FIG. 4 is a partial cross-sectional view showing one mode of operation of my invention.

With reference to FIG. 1 showing the general arrangement, the underground shelter 10 may be constructed of reinforced concrete with an hemispherical roof 11 and end walls 12. A heavy door 13 is provided in one of the end walls which opens from the shelter into a protected horizontal passage 14 which, in turn, communicates with a laddered vertical shaft 15. This latter shaft or passage may be covered with a heavy cover 16 which may be hinged or otherwise arranged for being secured in place by the last person descending shaft 15.

A ventilating duct 17 communicates with the interior of the shelter through the other end wall 12 and is extended upwardly until it rises just below the surface 18 of the ground over the shelter. A heavier fitting 19 may be fitted over the upper end of the ventilation duct for its protection. This fitting 19 may be flush with the surface 18 or extend slightly above it as shown. This fitting may also be provided with some form of cover or other closure for sealing the upper end of the ventilation duct when the shelter is not in use.

The ventilation duct 17 comprises an upper pipe or conduit 20, a valve casing 22 and a U-shaped conduit 24.

As shown in FIGS. 2, 3, and 4, pipe or conduit 20 and U-shaped conduit 24 consist of sheet metal pipe having a circular cross-section. These conduits, however, may be of any suitable similar configuration and may be composed of any suitable material other than sheet metal.

Valve casing 22 is generally rectangular in cross section and has a top 25, side walls 26 and 27, end walls 28 and 29, and a bottom 30. Casing 22 is provided with a central dividing wall 31 which is parallel to the end walls 23 and 29 and thus divides the interior of the casing into two passages or chambers 32 and 33. This dividing wall 31 extends from top to bottom, side wall to side wall and may be soldered, brazed or otherwise sealingly secured in place in the interior of the casing 22.

The top cover 25 of the casing 22 is provided with an orifice 34 communicating with the blast chamber or passage 32. The lower end of conduit 20 may be fitted into this orifice and sealingly secured therein or, for ease of construction and assembly, a fitting 35 may be secured in the orifice 34 which fitting will be adapted to receive the lower end of the conduit 20. A similar grifice 36 is provided in end wall 29 for an horizontal conduit or conduit fitting 37 which may lead into the interior of shelter it through end wall 12 and which communicates with the shelter chamber 33.

The bottom 30 is provided with two orifices 38 and 39 into which the ends of the U-shaped conduit 24 may be sealingly inserted or, again, fittings 40 and 41 may be secured to the bottom of the casing which fittings are adapted to receive and securely hold the upper ends of the U-shaped conduit 24. It will be noted that this U- shaped conduit thus provides an 180 curved passageway connecting the two chambers 32 and 33.

Dividing wall 31 is provided with an horizontal aperture 42 which is adapted to receive the central portion of the dihedral moving valve member 43. This latter part is supported by a shaft 44 which protrudes through and is journalled by the side walls 26 and 27, as shown at 45 in FIG. 2.

Moving valve member 43 is made from two plane surface vanes 46 and 47 which are connected to a central shaft receiving portion 4% at an angle preferably not less than 99". This included angle is not critical other than it should for complete ope-ration be not less than With the vanes 46 and 47 being of equal surface and weight, the valve member 43, under the influence of gravity, will assume the normal position shown in FIG. 3. Extending horizontally inwards. from the end walls and generally in line with the dividing wall aperture 42, sealin-g lips 49 are shown in FIGS. 3 and 4. These sealing lips are adapted to cooperate with the vanes of the dihedral moving valve member so as to prevent or inhibit any unusual flow of air through the ventilating system. While shown as extending laterally only from the end walls 28 and 2 9, similar lips could be installed in coplanar relationship with the first set of lips on the inner portions of side walls 26 and 27. Also, with only the two lips as shown, sealing material could be supplied to the vertical inclined edges ofthe vanes 46- and 47 so that a seal could be provided between the ends of the moving valve member and the side walls of the casing.

In the operation of my improved blast actuated ventilator valve, the normal flow of air is indicated by the anrows 50 where the closed end indicates ingress air flowing into the shelter and the open end indicating egress air flowing out of the shelter to atmosphere. Thus under normal conditions, valve member 43 is in the neutral position as shown in FIG. 3 and air may circulate to and from the interior of the shelter to atmosphere. It should be noted here that while only one ventilating duct system is shown, other similar systems could be installed on the same shelter for more natural circulation of air through the shelter. Fans or blowers could be easily installed in one or more of such ventilating duct systems to promote a forced circulation through the shelter. In this ciroumstance, under normal conditions, one system. would be used for supplying air to the shelter and the other systems could be used for exhaust.

With the occurrence of the atomic or nuclear blast, the pressure wave would enter the duct 20 and proceed downwardly therethrough. As the front of the pressure wave reaches the vane 46 it moves the latter downwardly and commences to close off the passage of the pressure wave through the shelter chamber 33. As the pressure wave continues its tortuous passage through the U-shaped conduit 24, it then enters shelter chamber 33 and impinges against the lower surface of vane '47. This impingement forces vane 47 against the lower surface of sealing lip 49 which effectually seals off this passage or chamber 33 and prevents or greatly inhibits the passage of the pressure wave into the shelter. This latter condition is shown in FIG. 4. As the pressure wave diminishes, valve member '43 tends to return to its normal position which it assumes when the pressure of the air in the shelter equals that of the atmosphere above ground surface 18.

In the event a negative pressure condition in the atmosphere follows the pressure phenomenon, the moving valve member will then be moved in the opposite direction to seal chamber 32 and prevent or inhibit the escape of air from the shelter. It should be noted here that one of the principal features of my invention resides in my having provided a blast actuated closure valve in which the blast or pressure wave must travel a comparatively considerable distance after initiating the actuation of the valve and before reaching the closing off or sealing portion. During this travel, the pressure wave is subject to a definite and measurable attentuation in force. Thus, if the initial pressure wave is of suffioient magnitude, its impingement against the upper surface of the vane 46 in the blast chamber 32 will be suificient to force vane 47 upwardly in sealing position before the wave front enters the shelter chamber .33. This action insures that the valving or sealing portion of the valve will be substantially closed before the blast impulse reaches it.

While a preferred embodiment of the invention has thus been described and shown, I do not intend to be limited thereby. Obviously many modifications and variations of the present invention are possible in the light of the above teachings. One modification, for instance, could be performed by slightly elongating, in a vertical direction, the bearing holes for the valve member shaft 44 which bearing holes are formed in the side walls 26 and 27 of casing 22. This elongation would permit a possibly improved sealing action of the valve vane 47 against the sealing lips, particularly where such sealing lips are provided on the side walls as mentioned above. It is to be further understood, therefore, that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Having thus described my invention, 1 claim:

In a ventilation system for underground shelters adapted to protect personnel from the positive and negative air pressure phases of the blast from high order explosive comprising, in combination:

a dual chambered casing installed in the ground adjacent one end of said underground shelter, said casing having a vertical median wall dividing said casing into two vertical chambers and said vertical median wall having a centrally disposed horizontal aperture formed therein;

a substantially vertical ventilation duet leading from the surface of the ground above said shelter to said casing, said vertical duct being connected to the upper portion of one of said vertical chambers in said casing;

a substantially horizontal ventilation duct leading from the upper portion of the other of said vertical chambers to the interior of said shelter;

a U-shaped conduit depending from the lower portion of said casing, said U-shaped conduit providing a passage from said one of said vertical chambers to to the other of said vertical chambers;

horizontally disposed sealing lips supported internally of the walls of said casing, said sealing lips being substantially coplanar with the horizontal aperture in said vertical median wall; and

a movable dihedral valve means having two planar vanes extending through said horizontal aperture in said vertical media-n wall, the apex of said valve memher being rotatably supported in said aperture, one of the vanes of said dihedral member extending into one of the said vertical chambers and the other vane extending into the other of said vertical chambers, the dihedral angle of said valve means being not less than ninety degrees, and the said vanes of said dihedral valve means being adapted to contact the under surfaces of said sealing lips and close the passage defined by said chambers and said U-shaped conduit when a blast of pressurized air impinges first on the upper surface of one of said vanes and then secondly on the lower surface of the other vane after said blast of pressurized air has passed through said U-shaped conduit.

References Cited in the file of this patent UNITED STATES PATENTS Schuster June 17, 1958 Drayer Feb. 17, 1959 FOREIGN PATENTS

Images