GB2121142A

GB2121142A - Quick closure mechanism for air passage openings, particularly for air conduits in shelters or the like

Info

Publication number: GB2121142A
Application number: GB08301304A
Authority: GB
Inventors: Gottfried Schindler; Johannes Schindler
Original assignee: Luwa Ltd
Current assignee: Luwa Ltd
Priority date: 1982-01-18
Filing date: 1983-01-18
Publication date: 1983-12-14
Also published as: NO830131L; SE8300214L; FI830146L; FI830146A0; SE8300214D0; CH654639A5; FR2520084A1; DE3300833A1; GB8301304D0; FR2520084B1

Abstract

A quick closure mechanism for a fluid passage includes first and second closure members 6 and 7 which are relatively movable between a closed position in which they engage one another and an open position in which they are spaced from one another, each member including a plurality of interconnected closing elements 8, 9 with passageways between them, the elements of each member being offset from the elements of the other and being wider than the passageways in the other so as to close said passageways when the members are in the closed position, and said elements of each member also being so shaped that, when the members are in the closed position, they project into the passageways in and laterally engage the elements of the other member. <IMAGE>

Description

SPECIFICATION Quick closure mechanism for air passage openings, particularly for air conduits in shelters or the like The present invention relates to a quick closure mechanism for a fluid passage which is particularly though not exclusively useful for positioning in air conduits for shelters or other spaces.

Quick closure mechanisms are known which include normally open valves which rapidly close in the event of a substantial increase in pressure.

In the open condition air can pass but upon the occurrence of a pressure wave of given magnitude the valve will automatically close. Such mechanisms are needed in air conduits leading to hazardous or explosion endangered or confined locations such as shelters and serve to prevent the passage of a pressure wave thereinto. Ideally, such quick closure mechanisms have a small fluid resistance when open and the capability of closing within a fraction of a second, when a pressure wave arrives. It is also desirable that it should be undamaged by pressure pulses to which it is subjected.

Explosion protection valves are known, for example, from U.S. Patent Nos. 3,015,342, 3,296,952 and 3,301,168. However, the embodiments disclosed in these references suffer from practical disadvantages such as complex arrangements for and difficulties in moving and guiding one set of closing members towards and into engagement with another, and large fluid resistance even when open due to cumbersome design of closure members which leads to requirements for larger ratings of air throughput and increasing demand on space. A further problem encountered in the prior art is that the closure members do not always well withstand pressure pulses.

According to the present invention there is provided a quick closure mechanism for a fluid passage including first and second closure members which are relatively movable between a closed position in which they engage one another and an open position in which they are spaced from one another, each member including a plurality of interconnected closing elements with passageways between them, the elements of each member being offset from the elements of the other and being wider than the passageways in the other so as to close said passageways when the members are in the closed position, and said elements of each member also being so shaped that, when the members are in the closed position, they project into the passageways in and laterally engage the elements of the other member.

With the invention, rapid and effective closing movement can be obtained As the closing elements of the closure members engage adjacent elements of the other closure member, the closing pressure generated by the pressure pulse can assist in providing a good seal. The elements support one another and resist permanent deformation.

Preferably, the closing elements are rod-like and, in cross-section, are dome-shaped where they face the elements of the other member.

Preferably also the closing elements of each closure member are interconnected at their ends by means of a corresponding connecting member, which has sections intermediate the closing elements on the side facing the other closure member. Each such section forms a seat for a closing element at the other closure member. In the closed position, the closing element or a section of the connecting member overlapping the same will sealingly engage the seat, so that a good sealing action can be achieved at the ends of the closing elements.

In order that the invention may be more clearly understood, the following description is given by way of example only with reference to the accompanying drawings, in which: Figure 1 is a front view of a first embodiment comprising two closure members of a quick closure mechanism according to the invention; Figure 2 is a sectional view taken substantially along the line Il-Il in Figure 1; Figure 3 is a sectional view on an enlarged scale taken substantially along the line Ill-Ill in Figure 1; Figure 4 is a fragmentary perspective view, partially broken away, of part of the end sections of the two closure members in their closed position;; Figure 5 is a view corresponding to Figure 3 of a second embodiment comprising two fixedly arranged closure members and a displaceably arranged closure member of the quick closure mechanism constructed according to the invention; Figures 6 and 7 show a section through parts of the closing elements of two closure members in the open position and in the closed position, respectively, of a quick closure mechanism according to the invention; and Figure 8 shows a section through parts of two closure members of a third embodiment of the quick closure mechanism according to the invention.

Describing now the drawings, it is to be understood that in order to simplify the illustration only enough of the construction of the quick closure mechanism has been shown as needed for those skilled in the art to readily understand the underlying principles and concepts of the present invention. Turning now specifically to the first embodiment of a quick closure mechanism according to the invention, as shown in Figures 1 to 3 of the drawings, there is depicted a substantially rectangularly shaped housing frame 1 which comprises an inwardly protruding marginal ledge 2 at one side thereof. Other marginal ledges 3 are disposed at the side or end of the frame opposite to the marginal ledge 2. The marginal ledges 3 are secured to the the housing frame 1 by means of threaded bolts or screws 4 and they are supported at a protruding marginal section or portion 5 of the housing frame 1.

Two closure members 6 and 7 are disposed within the space bounded by the marginal ledges 2 and 3. The closure member 7 is fixedly arranged and the other closure member 6 is displaceable in the direction of the arrow D. Each closure member 6 and 7 comprises substantially rod-shaped closing or closure elements 8 and 9, respectively, which extend essentially in parallelism to each other and which are arranged at equal distances A (see Figure 3). The closing elements 8 and 9 of the closure members 6 and 7, respectively are separated from each other by air passageways or throughpass openings 10 and 11, respectively.

The closing elements 8 of the displaceable closure member 6 have a circular cross-section, which means that the exterior face 8a thereof is formed by the jacket or outer surface of a circular cylinder.

In contrast thereto, the closing elements 9 of the fixedly arranged or stationary closure member 7 have an elongate cross-sectional configuration.

On the side facing the displaceably arranged closure member 6 the closing elements 9 contain an exterior face 9a having a section which is also formed by a jacket or outer surface of a circular cylinder. The closing elements 9 taper in a direction away from the displaceable closure member 6, so that the air passageways 11 intermediate the closing elements 9 widen in the manner of a diffusor. By virtue of such design of the air passageways 11 the flow characteristics are improved, resulting in an increase in the air throughput for a given flow-facing or attack surface of the quick closure mechanism and for a given pressure drop.Additionally, by virtue of the illustrated design of the closing elements 9 the strength of the closure member 7 is increased as compared to a design including circular cylindrical elements corresponding to the closing elements 8.

The closing elements 8 of the displaceably arranged closure member 6 and equally the closing elements 9 of the fixedly arranged closure member 7 are interconnected at their ends by means of a connecting member 12 1 3, respectively, as will be particularly evident from Figures 3 and 4. The closing elements 8 and 9 are retained in their relative position by the connecting or connection members 12 and 13, respectively, in which the closing elements 8 are off-set or shifted relative to the closing elements 9 such that the closing elements 8 or 9 of the one closure member 6 or 7, respectively, are located opposite the passageways 10 or 11, respectively, of the respective other closure member 6 or 7, respectively, so that the passageways 10 and 11 can be closed by the closing elements.As will be particularly recognized from Figure 6, the closing elements 8 are off-set from the closing elements 9 by an amount B which amounts to about half the distance A between the central axes of adjacent closing elements 8 and 9 of the closure members 6 and 7, respectively. The sections or portions 1 2a and 1 3a formed in the connecting members 12 and 13, respectively, and located between the closure elements 8 and 9, respectively, are placed back or inset from the side facing the other closure member 6 or 7, respectively, intermediate the closing elements 8 and 9, and comprise seats forming contact or engagement surfaces 14 and 15, respectively, operatively associated with the related closing element 8 or 9, as the case may be.

The contact or engagement surfaces 14 and 1 5 correspond in shape to the external or exterior faces 8a and 9a of the closing elements 8 and 9, respectively, with which they sealingly coact in the closed position of the closure members 6 and 7.

As will be seen from Figure 2, the displaceably arranged closure member 6 is retained in its open position by the action of spring elements 1 6 or equivalent structure which only have been shown schematically. In the open position the displaceably arranged closure member 6 engages the marginal ledge 2 and extends at a distance from the fixedly arranged or stationary closure member 7. Guiding or guide ledges 17 and 1 8 are arranged at the upper portion and at the lower portion of the housing frame 1 in order to guide the closure member 6. The closure member 6 may be guided laterally either by the interior wall of the housing frame 1 or, also, by means of suitable guiding ledges.

A particularly favorable arrangement of the closing elements 8 and 9 will now be explained with reference to Figures 6 and 7. Therein, for simplicity the closing elements 9 of the fixedly arranged closure member 7 have also been represented as circular cylindrical rods. In the open position the two closure members 6 and 7 are held at such a distance or spacing from one another that the inner width of the air passage 21 formed intermediate each closing element 8 of the closure member 6 and the respectively adjacent closing elements 9' and 9" of the other closure member 7 amounts to half the inner width 20 of the air passageways 10 and 11 between the closing elements 8 and 9. In such an arrangement no adverse cross-sectional changes occur in the air flow path.Additionally, the closing path 22 (see Figure 7) of the displaceably arranged closure member 6 is correspondingly small. If, for example, the width 19, i.e. the diameter, of the closing elements 8 and 9 is 20 mm and the inside or inner width of the passageways 10 and 11 half thereof, i.e. 10 mm, then the inner width of the passage 21 is 5 mm and the closing path 22 of the displaceably arranged closure member 6 will amount to about 6 mm. Therefore, such an arrangement will result in extremely short closing times. Additionally, a small closing path is equivalent to a short acceleration path of the displaceably arranged closure member 6, and thus, to a smaller final or terminal velocity of the same. Since the energy to be dissipated, when the displaceably arranged closure member 6 encounters the fixedly arranged closure member 7, is proportional to the square of the speed of the displaceably arranged closure member 6, the forces acting upon the closure members 6 and 7 will be correspondingly smaller.

When a pressure wave impinges upon the closure member 6 in the open position thereof, then such closure member 6 will be displaced in the direction of the arrow D towards the fixedly arranged or stationary closure member 7 in opposition to the force of the springs 1 6 retaining the closure member 6 in its open position. When the closure member 6 contacts the closure member 7 the closing elements 8 of the closure member 6 will laterally engage the closing elements 9 of the closure member 7 as shown particularly well in Figure 7. Under the action of the pressure wave the closing elements 8 and 9 are sealingly engaged at the locations of their lateral engagement or contact. Additionally, the closing elements 8 of the displaceably arranged closure member 6 are laterally supported at the closing elements 9 of the fixedly arranged closure member 7.As small as possible deformation of the closing elements 8 is thus obtained by virtue of such supporting action. As already previously mentioned and as will be particularly evident from Figure 4, due to the specific design of the connecting or connection members 12 and 13 a good sealing action is also achieved at the ends of the closing elements 8 and 9, respectively, at the end faces or ends of the closure members 6 and 7, respectively. As will be apparent from an inspection of Figure 4, the external or exterior faces 8a of the closing elements 8 sealingly contact the engagement or contact surfaces 1 5 at the connecting members 13, whereas the exterior or external faces 9a of the closing elements 9 sealingly contact the engagement or contact surfaces 14 at the connecting members 12.

In a modification of the embodiment as described hereinbefore with reference to Figures 1 to 3, the closure member 7, also, can be journalled or mounted for displacement within the housing frame 1. Then, the quick closure mechanism will also close under the action of the suction following the pressure wave. Upon impingement of a pressure wave in the direction of the arrow D (see Figure 3), then in the manner heretofore explained the closure member 6 will be displaced towards the other closure member 7 which is supported at seat or seating surfaces 24 at the marginal ledges 3. During the suction phase following the pressure wave an air flow occurs in the direction of the arrow S (see Figure 3) and the closure member 6 is returned until engaging seat or seating surfaces 23 formed at the marginal ledges 2.The other closure member 7, which is also moved in the direction of the arrow S, now engages or contacts the closure member 6, whereby the air passageways 10 and 11 are also closed in the manner as already described hereinbefore. The two closed positions of the two closure members are indicated in Figure 3 by broken lines and are designated by reference numerals 6' and 7', respectively.

A further embodiment of quick closure mechanism constructed according to the invention and which also closes automatically under the action of a pressure wave as well as under the action of the suction force following the same is shown merely schematically in Figure 5.

Just as was the case for the embodiment shown in Figures 1 to 3 there are also provided a fixedly arranged closure member 7 and a displaceably arranged closure member 6. In their construction the aforementioned closure members 6 and 7 substantially correspond to the closure members 6 and 7 of the first embodiment shown and discussed previously with reference to Figures 1 to 3. The substantially rod-like closing elements 8 and 9 of the closure members 6 and 7, respectively, are also interconnected at their ends by means of connecting or connection members 12 and 13, respectively, which are designed on the side facing the respective other closure member 6 or 7, as the case may be, similarly as shown in Figure 4.Above the displaceably arranged or movable closure member 6 there is disposed a second fixedly arranged closure member 25 which, in principle, is constructed similar to the fixedly arranged closure member 7.

Contrary thereto, however, the second fixedly arranged closure member 25 has closing elements 26 of substantially circular cylindrical shape. The air passageways present intermediate the closing elements 26 are designated by reference numeral 27. At their ends the closing elements 26 are interconnected by means of a connecting or connection member 28. The sections or portions 28a of the connecting member 28 located intermediate the closing elements 26 have an engagement or contact surface 29 on the side facing the closure member 6. The engagement or contact surface 29 corresponds in shape to the exterior face of the closing elements 8 which sealingly can engage the same.The displaceably arranged closure member 6 is retained in a central position intermediate the two fixedly arranged closure members 7 and 25 by means of merely schematically depicted retaining springs 30, so that in the operative position air may flow through the passageways or throughflow openings 27, 10 and 11.

When a pressure wave impinges in the direction of the arrow D, the displaceably arranged closure member 6 will be displaced towards the fixedly arranged closure member 7, whereby the air passageways 10 and 11 are closed in the manner as already described hereinbefore. During the following suction phase the displaceably arranged closure member 6 will be displaced in the opposite direction, i.e. in the direction of the arrow S, from the closure member 7 towards the fixedly arranged closure member 25. When the closure member 6 encounters or contacts the closure member 25, the air passageways 10 and 27 now will be closed also in the manner already described hereinbefore.

The embodiment shown in Figure 5 has the disadvantage of a greater flow resistance in comparison to the double-acting quick closure mechanism already described hereinbefore with reference to Figure 3 which only has a total of two closure members.

A still further embodiment of the quick closure mechanism according to the invention is indicated only schematically in Figure 8. The closure members 31 and 32 thereof differ from the closure members 6 and 7 of the embodiment as shown and discussed with reference to Figures 1 to 3 by virtue of a different cross-sectional shape of the closing elements 33 and 34, respectively, between which passageways are defined and have been designated by reference numerals 35 and 36, respectively. As will be evident from Figure 8, the closing elements 33 and 34 are also of a substantially rod-like design and have a rectangular, in particular a square cross-sectional configuration. At the edges thereof facing the closing elements of the respective other closure member 31 or 32 there are provided inclined contact surfaces or faces 38 and 39, respectively.

In the closed position of the two closure members 31 and 32 the closing elements 33 including the inclined contact faces or surfaces 38 contact the inclined contact faces or surfaces 39 of the adjacent closing elements 34 at the closure member 32. Due to the angular or edge-like shape of the closing elements 33 and 34 the flow characteristics of this embodiment are less favorable than those of the embodiment shown in Figures 1 to 3.

Reference also is to be made in this respect that the closing elements as such may have any suitable cross-sectional shape including, for example, also an elliptical shape.

After removal of the releasable marginal ledges 3 the closure members 6 and 7, are readily assembled and disassembled in the embodiment of the quick closure mechanism shown in Figures 1 to 3. The releasable marginal ledges 3 engage edges or margins 5 forming part of the housing frame 1. Consequently, strong forces may be transferred to the housing frame 1 from the closure members 6 and 7 via the marginal ledges 2 and 3 and the edges or margins 5. An eventually required exchange of the marginal ledges 3 can be achieved in a simple manner.

When, as discussed with reference to Figures 6 and 7, provision is made for the closing path of the displaceably arranged closure member 6 to be small, then a small amount of play between the displaceably arranged closure member 6 and the housing frame 1 will suffice to prevent the displaceably arranged closure member 6 from tilting and wedging or binding in the event that the pressure wave impinges at an angle.

By appropriately dimensioning the rod-shaped closing elements 8 and 9 there may be fabricated quick closure mechanisms of the type described hereinbefore which operate faultlessly under pressure waves up to 100 bar and above without becoming damaged and which notwithstanding have a small flow resistance.

In the embodiments as illustrated and described hereinbefore, the connecting or connection members 1 2 and 13 are designed in such a way that the closing elements 8 and 9 are free on their sides facing the connecting member 12 or 13, respectively, of the respective other closure member 6 or 7. It is possible, however, for the connecting members 12 and 1 3 to overlap or to engage over the closing elements 8 and 9, respectively. In such case the overlap sections of the connecting members and the contact or engagement surfaces 14 and 1 5 of the respective other connecting member 12 or 13, as the case may be, will have to be designed such that the overlap sections of the connecting members sealingly engage the contact or engagement surfaces 14 and 1 5 of the oppositely situated connecting member.

While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. ACCORDINGLY,

Claims

1. A quick closure mechanism for a fluid passage including first and second closure members which are relatively movable between a closed position in which they engage one another and an open position in which they are spaced from one another, each member including a plurality of interconnected closing elements with passageways between them, the elements of each member being offset from the elements of the other and being wider than the passageways in the other so as to close said passageways when the members are in the closed position, and said elements of each member also being so shaped that, when the members are in the closed position, they project into the passageways in and laterally engage the elements of the other member.

2. A quick closure mechanism according to claim 1, wherein the closing elements are rod-like and, in cross-section, are dome-shaped where they face the elements of the other members

3. A quick closure mechanism according to claim 2, wherein the closing elements are cylindrical with the cross-section of the cylinder being circular at least in the parts where the elements face the elements of the other member.

4. A quick closure mechanism according to any preceding claim, wherein the closing elements of each closure member are substantially equispaced and parallel to each other and the closing elements of each closure member are off-set relative to those of the other closure member by approximately half the distance between closing elements.

5. A quick closure mechanism according to any preceding claim, including connecting members interconnecting the closing elements of each closure member, the connecting members having sections located between the closing elements it connects and facing the other closure member, each said section having a seating surface to receive and sealingly engage with a corresponding closing element in the other closure member when the members are in the closed position.

6. A quick closure mechanism according to claim 5, including corresponding contact surfaces formed by each said seat and closing element.

7. A quick closure mechanism according to any preceding claim, wherein, when the members are in the open position, the gaps between one of the closing elements of one member and the adjacent closing elements of the other member are about half as wide as the width of the passageways between adjacent elements of the members.

8. A quick closure mechanism according to any preceding claim, wherein one of the closure members is fixed and the other is displaceable, and including means urging the dispiaceable closure member away from said fixed one and means to limit the distance the members can move apart.

9. A quick closure mechanism according to any one of claims 1 to 7, wherein both the closure members are displaceable, and including means urging them apart and means to limit the distance the members can move apart.

10. A quick closure mechanism according to claim 8 or 9, including a spring urging the members apart.

11. A quick closure mechanism according to any one of claims 1 to 7, including a third closure member, said first and second closure members being fixedly arranged at a distance from each other and said third closure member being displaceable intermediate the first and second closure members; and including means urging said third closure member to a substantially central position between the first and second closure members.

12. A quick closure mechanism according to any preceding claim, including a housing in which said closure members are mounted and guided.

13. A quick closure mechanism according to any preceding claim, wherein the passageways formed in the first closure member widen in a direction away from the second closure member.

14. A quick closure mechanism constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.