Normally-closed explosive-actuated valve

Aug. 24, 1965

H. F. ECKARDT ETAL

3,202,162

NORMALLY-CLOSED EXPLOSIVE-ACTUATED VALVE

Original Filed May 9, 1960

<img file="US3202162A_D0001.tif" />

<img file="US3202162A_D0002.tif" />

United States Patent Office „ 3,202,162

Patented Aug. 24, 1965

3,202,162

NORMALLY-CLOSED EXPLOSIVE-ACTUATED VALVE

Hans F. Eckardt, 181'61 Allegheny Drive, Santa Ana, Calif., and John L. Marsh, 628 Arbolado Drive, Fullerton, Calif.

Continuation of application Ser. No. 27,870, May 9, 1960. This application Jan. 7,1963, Ser. No. 249,953

Claims. (Cl. 137—68)

This invention relates to an explosive-actuated valve of the normally-closed type. This application is a continuation of our co-pending patent application Serial Number 27,870, filed May 9, 1960, for Normally-Closed ExplosiveActuated Valve, and since abandoned.

An object of the present invention is to provide an explosive-actuated valve which is simple and economical to manufacture yet is highly reliable, effective and efficient in operation.

A further object is to provide an explosive-actuated ₂₀valve which positively prevents any flow prior to actua- ^υtion, yet permits unrestricted and turbulence-free straightthrough flow subsequent to actuation.

Another object of the invention is to provide an explosive-actuated valve incorporating a combination energyabsorbing and seal or isolation means adapted not only to retard movement of the ram subsequent to the explosion but also to prevent products of the explosion from entering the controlled fluid.

Another object of the invention is to provide a valve incorporating a blind nipple element which prevents the pressure of the controlled fluid from entering the explosive element prior to actuation, and which prevents the controlled fluid from causing hydraulic lock prior to actuation.

An additional object of the invention is to provide an explosive-actuated valve incorporating means effective to prevent the sheared nipple portion from entering the fluid stream, and to prevent chips and contaminants from entering the fluid stream.

These and other objects and advantages of the invention will be more fully set forth in the following specification and claims, considered in connection with the attached drawing to which they relate.

In the drawing:

FIGURE 1 is a longitudinal sectional view illustrating an explosive-actuated valve constructed in accordance with the present invention;

FIGURE 2 is a transverse section taken on line 2—2 of FIGURE 1;

FIGURE 3 is a longitudinal section corresponding to FIGURE 1 but illustrating the parts in the positions assumed subsequent to actuation; and

FIGURE 4 is a longitudinal section of a second embodiment wherein both threaded fittings for the fluid conduits are machined integral with the valve body, and wherein the nipple is suitably pressed, shrunk or taperfitted in position.

Referring first to the embodiment shown in FIGURES 1-3 of the drawing, the explosive-actuated valve may be seen to comprise an elongated hollow body 1®, an elongated ram 11 mounted coaxially in body 10 for longitudinal movement therein, and a nipple element 12 having a portion adapted to be sheared off upon movement of the ram longitudinally of the body. Means are provided 65 to create a straight-through flow path for the controlled fluid in response to shearing of nipple 12 subsequent to igniting of the explosive actuator or squib which is indicated at 14. As will be described in detail subsequently, such means includes energy absorbing, stop and sealing portions which perform various functions including pre2 vention of contamination of the controlled fluid by the products of the explosion.

The hollow body 10 is closed at one end by a wall 16 and is open and internally threaded at the other end to threadedly receive the explosive actuator or squib 14. One portion 17 of the valve chamber within body 10, adjacent end wall 16, is cylindrical and relatively small in diameter. Another and coaxial chamber portion, numbered 18 and located adjacent squib 14, is also cylindrical but has a somewhat larger diameter. Chamber portions 17 and 18 are axially spaced from each other and are connected by a tapered or frustoconical portion 19 the wall of which forms part of the energy-absorbing means indicated above, being adapted to absorb energy from ram 11 and also to create a seal.

The ram 11 incorporates portions shaped to conform, except as will be described subsequently, to the walls of the smaller-diameter and tapered chamber portions 17 and 19. The ram also includes, relatively adjacent the squib 14, a short cylindrical portion which corresponds in diameter to chamber portion 18. Such larger-diameter ram portion is provided with an O-ring seal 21 which slides sealingly on the wall of chamber portion 18 to create an initial seal preventing contamination of the controlled fluid by propellant gases.

The inner end of ram 11, in chamber portion 17, is machined flat to provide a surface 22 lying in a plane parallel to the ram axis and spaced a short distance thereabove. The ram portion relatively adjacent end wall 16 is formed with a cylindrical recess 23 the axis of which is perpendicular to flat surface 22 and intersects the ram axis. A port or passage 24 is formed through the flattened ram portion a short distance from recess 23, such port being cylindrical and having an axis which is perpendicular to surface 22 and intersects the axis of the ram. The port or passage 24 forms a part of the previously-indicated means for creating the straight-through fluid flow path in response to shearing of the end of nipple element 12.

Nipple element 12 is shown in FIGURES 1 and 2 as being suitably threaded into body 10 in such manner that its axis intersects that of ram 11. The outer portion of the nipple element, which forms the inlet to the valve, is shown as being suitably threaded to receive a connector conduit (not shown). It is to be understood that the valve ₄₅ inlet (and also the valve outlet) may be constructed as a flared tube fitting, flareless tube fitting, internally-threaded boss, internally or externally-threaded pipe thread or manifold, etc. A wrench-hold portion 26 is formed on the nipple and is adapted to seat on an O-ring 27, the latter ₅₀ being suitably seated in the valve body around the nipple for prevention of leakage from the valve chamber.

The inner end of nipple 12 comprises a relatively thickwalled tubular portion 28 extending to the plane of flat surface 22, and a coaxial and relatively thin-walled tubular ₅₅ portion 29 disposed in recess 23 and having a closed or blind end wall 31. An external shoulder or stress riser 32 is formed at the junction of the thick-walled and thinwalled tubular portions 28 and 29, in the plane of flat surface 22, and performs important functions to be described hereinafter.

The valve body 10 is formed integrally with an outlet portion 33 which may correspond to the outer portion of nipple 12. It is emphasized that outlet portion 33 is formed with a straight passage which is coaxial with the passage or chamber in nipple 12, and has the same diameter. The port or passage 24 through ram 11 also has the same diameter, so that subsequent to actuation of the valve (FIGURE 3) these three passages will combine to create a single unrestricted straight-through flow passage between the valve inlet and valve outlet.

The explosive element or squib 14 may be Of any suitable construction known to the art, and may contain a

3,202,16:

.³ solid propellant such as is used in rocketry. The explosive may be electrically or mechanically ignited. A suitable O-ring 34 is provided to prevent leakage of gas around the squib 14.

The distance between the axis of recess 23 and that of port or passage 24 corresponds to the distance between the end wall 16 and the inner end of ram 10, so that port 24 will be precisely aligned with the inlet and outlet passages subsequent to actuation (FIGURE 3). This distance is substantially greater, however, than the distance between the tapered portion of ram 11 and the wall of tapered portion 19 of the valve chamber. It follows that substantially before the inner end of the ram contacts the wall 16, the tapered portion of the ram will engage the tapered wall of the valve chamber to commence dissipation of the energy created by the explosion. The ram is then deformed into such shape that it creates a secondary seal preventing leakage of gases to the flow path. Such deformation is facilitated by the presence of an axial bore 36 formed in the outer end of the ram.

OPERATION

The valve is readily assembled by merely inserting the ram 11 into the valve chamber and so positioning the ram that recess 23 is opposite and coaxial with the internally-threaded valve-body opening for nipple 12. Nipple 12 is then threadedly inserted into the valve body, in such manner that its inner end portion 29 enters the recess 23 as shown in FIGURES 1 and 2. Assembly is then completed by threading the squib 14 into the open end of the valve body. Suitable conduits are then connected to the outer portion of nipple 12 and. to valve outlet 33.

Since the nipple 12 is blind and is of integral construction, there is no possibility of leakage from the valve inlet to the outlet 33, to squib 14 or to the small-diameter portion 17 of the valve chamber. This eliminates all possibility of interaction between the controlled fluid and the explosive, and also eliminates the possibility of hydraulic lock due to the presence of controlled fluid in the valve chamber.

When the squib or explosive element 14 is electrically or mechanically ignited, the resulting gases are trapped by O-rings 21 and 34 between the outer end of ram 11 and the squib. Ram 11 is then propelled inwardly in an unimpeded manner (except for the resistance caused by the nipple shearing at stress riser 32, to be discussed below) until the tapered ram portion engages the wall of tapered portion 19 of the valve body. Thereafter, as discussed above, the outer portion of the ram is deformed to result in absorbing of the energy created by the explosion. It follows that the engagement of the inner end of the ram with wall 16 will be with insufficient force to create undesirable effects such as rebound or fracture. Furthermore, and very importantly, the engagement between the tapered portions of the valve body and ram provides a secondary seal which is highly effective to prevent gases from entering the controlled fluid after the gas pressure between the ram and the squib becomes so great that O-ring 21 is no longer effective to prevent leakage.

During the above-described inward shifting of ram 11 from the FIGURE 1 position to the FIGURE 3 position, the inner portion 29 of nipple 12 is sheared off cleanly at the shoulder or stress riser 32, and travels in recess 23 into the chamber portion 17. The resulting close surface contact between flat surface 22 and the inner end of the thick-walled tubular nipple portion 28 results in several important advantages. Such advantages include preventing the ram 11 from rotating about its longitudinal axis, thereby insuring that port 24 will be in perfect axial alignment with the inlet and outlet passages. Another advantage is that contaminants and chips are prevented from entering the fluid stream. The presence of the stress riser or shoulder 32 insures that there will be no bending at the fracture point, but only an extremely clean fracture.

EMBODIMENT OF FIGURE 4

The embodiment of FIGURE 4 is identical with that of FIGURES 1-3, except as will be described subsequently. Corresponding reference numerals have been employed to denote corresponding parts, certain reference numerals in FIGURE 4 being followed by the letter a.

In the construction of FIGURE 4, the threaded fitting for the inlet conduit is machined integral with the valve body Ιΰα, as shown at 37. The nipple 12α is then pressed, shrunk or taper-fitted into the portion 37 of the valve body and in such manner that its blind inner end enters the recess 23 as in the case of the previous embodiment. In accordance with the present embodiment, an annular groove 3S is provided in the inner end portion of the nipple, at flat surface of the ram. Such groove augments the action of the stress riser in insuring a clean fracture of the nipple.

It is to be understood that the present invention may also be incorporated in a tandem valve having two or more sets of inlet and outlet passages in axial alignment (respectively) with each other. In such valves, the ram incorporates a recess 23 and port 24 for each coaxial set of inlet and outlet passages. Furthermore, and very importantly, the valve body and the ram incorporate cooperating tapered portions not only between the single squib and the adjacent coaxial valve passages but also between adjacent sets of coaxial passages. Such tapered portions between the adjacent sets of coaxial valve passages serve to isolate the controlled fluids from each other, in addition to absorbing the energy created by the explosion. Suitable O-rings may also be provided between adjacent sets of valve passages.

Various embodiments of the present invention, in addition to what has been illustrated and described in detail, may be employed without departing from the scope of the accompanying claims.