US3453777A

US3453777A - Pressure venting panel assembly

Info

Publication number: US3453777A
Authority: US
Inventors: Thomas Joseph Reilly
Original assignee: American Cyanamid Co
Current assignee: Wyeth Holdings LLC
Priority date: 1967-11-07
Filing date: 1967-11-07
Publication date: 1969-07-08
Anticipated expiration: 1986-07-08

Description

July 8, 1969 T. J. REILLY PRESSURE VENTING PANEL ASSEMBLY Filed Nov. 7, 1967 INVENTOR. 772021205 Jose M Hediy United States Patent US. Cl. 49-141 6 Claims ABSTRACT OF THE DISCLOSURE Disclosed herein as a preferred embodiment of the invention is a pressure venting window panel assembly for use in relieving pressures built up in an enclosed building structure as a result, for example, of an explosion.

The assembly includes a panel, pivotably mounted to open and close an opening in the building wall and secured by a magnetic latch. The magnetic latch permits the assembly to be calibrated to open upon attainment of a predetermined pressure level within the enclosure and comprises a horse-shoe magnet, and a keeper which magnetically engages the magnet to secure the latch in a closed position. The keeper also acts as a shunt to maintain the latch at its calibrated value during periods when the panel assembly is closed.

Background of the invention Industrial explosions have become an ever increasing problem as the complexity of industry has grown. In order to protect personnel and save enclosed buildings and equipment from structural damage it is desirable, and required by insurance underwriters, that pressure relief venting be provided in any enclosure in which an explosion hazard exists. The use of venting is particularly important in those instances where one side or a number of sides of an enclosure are constructed of, or contain areas of glass. If venting can be accomplished before the glass areas are shattered, the chances of injury to personnel are considerably reduced.

In addition, it is often desirable to provide venting in enclosures where the exertion of high pressures of less than explosive intensity may occur, to prevent distortion or structural damage.

'I-Ieretofore, venting has often been accomplished by means of louvers, of either the permanent or pivot-hinge type, which are installed in the walls of an enclosure. Louvers of any type, however, are unsatisfactory in situations where the enclosure must contain a certain amount of internal pressure such as in forced air drying ovens and in rooms having forced ventilation.

Alternatively, panels which are secured by mechanical latches designed to open under pressure have been used to vent enclosed structures. The mechanical type latch, however, has proven to be expensive and difiicult to install; more importantly, mechanical latches are extremely difficult to calibrate for release at redetermined pressure levels. In addition, any calibration effected on a mechanical latch is subject to significant change in time as a result of mechanical distortion, oxidation and corrosion.

Accordingly, representative objects of the present invention are to provide a means for the pressure relief venting of enclosed structures such as industrial buildings, drying ovens, storage tanks, ducts and the like, which is readily calibrated to open at a predetermined pressure level, and which is reliable, inexpensive and easy to install.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement 3,453,777 Patented July 8, 1969 of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

Summary of the invention The present invention relates to a pressure venting panel assembly for enclosed structures, having a mag netic latch for accurate calibration and reliable operation.

Referring to FIGURE 1, the panel assembly comprises a panel 10, which may be a glazed window as shown, pivotably mounted in a frame 12 surrounding an opening 14 in the wall 16 of an enclosure.

A magnetic latch 18, comprising a magnetically attractive keeper 20 mounted on panel 10 and a permanent magnet 22 mounted to frame 12, secures the panel of the invention in a closed position as shown at the top of FIGURE 1. Latch 18 is calibrated, as is more fully described herein, so that keeper 20 will disengage from magnet 22 upon the application of sufiicient pressure P to the surface 24 of panel 10, as when. an explosion or high pressure condition occurs within the enclosure. The disengagement of keeper 20 from magnet 22 allows panel 10 to open as shown at the bottom of FIGURE 1, thus forming a vent for the release of excess pressure.

The calibration of latch 18 should be such that venting occurs at a pressure level below the rupture pressure of the walls 16 of the enclosure to prevent structural damage thereto. In addition, where glazed windows are used as panels as shown in FIGURE 1, latch 18 should be calibrated to disengage at a pressure below the breaking stress of the glass to minimize the danger to personnel. The strengths of common types of glass can be determined from sources such as Breaking Stress of Glass at Ambient and Low Temperatures, K. E. Anderson, H. W. Tyler and R. V. Smith, Design News, Oct. 12, 1959.

Brief description of the drawings For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing in which:

FIGURE 1 is a front perspective view of two pressure venting window panels in accordance with the invention, the upper panel showing the closed and the lower panel showing the open position thereof.

FIGURE 2 is an enlarged sectional view taken along line 2-2 of FIGURE 1 showing, in dashed lines, the panel of the invention in open and partially open positions.

FIGURE 3 is a greatly enlarged partial sectional view taken along line 3-3 of FIGURE 1.

Similar reference characters refer to similar parts throughout the several views of the drawing.

Description 0 the preferred embodiments Referring now to FIGURE 1, the pressure venting panel assembly of the invention comprises a panel 10 which may be a solid sheet of suitable metallic, plastic or similar material; preferably, however, and in particular where the panel assembly is used in habitated building structures such as factories, research labs and the like, panel 10 comprises a glazed window having a glass sheet 26 suitably mounted in a casement 28 and secured therein by putty 30 or a similar glazing material (FIGURE 3). Casement 28 is provided with an abutment 32, and channel strips 34 are forcefitted between abutment 32, and glass sheet 26 to reinforce the putty 30 in securing glass sheet 26.

Panel 10 is pivotably mounted either singly, or in groups as shown in FIGURE 1, in a frame 12 surrounding an opening 14 in the wall 16 of an enclosed structure.

3 Frame 12 may be formed of extruded metal, wood or similar suitable materials and the configuration thereof should conform to the configuration of casement 28 so that the two can mesh to substantially seal opening 14 when panel is closed. As shown in FIGURE 3, when the panel assembly is closed an upstanding lip 36 running along the outside edge of frame 12 is abutted by the outside dependent flange 38 of casement 28, and the upstanding flange 40 along the inside edge of frame 12 is abutted by the inside edge 42 of casement 28 to seal the opening and provide an air space 44. Where further sealing is desired, resilient gaskets may be secured to one or both of the mating surfaces of lip 36 and flange 38, and/or edge 42 and flange 40.

The pivotable mounting of panel 10 is effected by means of a pair of pivot pins 46 (FIGURE 1) protruding at one end from bearing blocks 48 at each end of the top surface 50 of casement 28. The other end of each pivot pin 46 is received in a sliding block 52 loosely mounted in a slide channel 54 on the inside end surface 56 of frame 12. Pivot pin 46 may be pivotably mounted in either bearing block 48 or slide block 52 and fixed in the opposite member, however, it is preferably pivotably mounted in both

block

48 and 52 to minimize the chances of binding. Thus, as illustrated by FIGURE 2, panel 10 may be pivoted between open and closed positions as a result of the sliding action of block 52 in channel 54 and the pivoting action of pin 46. A stop 58 is also provided in each channel 54 both to limit the sliding movement of block 52 and thus limit the outward movement of panel 10 to a desired degree, and to prevent block 52 from leaving channel 54.

In applications where the panel assembly of the invention must withstand and vent pressures due to explosion, panel 10 should preferably remain open after an initial explosion. This is important since secondary explosions following closely behind the initial explosion may otherwise occur as panel 10 is returning to its closed position, and the combined force of the secondary explosion outward, and the momentum of panel 10 inward may cause structural damage to the panel or shatter the glass 26. Accordingly, a linkage arm 60 is pivotably fastened at one end 62 to each side of casement 28 below pivot pin 46. The other end 64 of arm 60 is pivotably attached to a stud assembly 66 projecting from the inner surface 56 of frame 12, below and in line with channel 54. The pivotal connections at 62 and 64 should be loosely made to minimize friction so that panel 10 will readily swing open upon application of a predetermined pressure force as shown in FIGURE 2. Arm 60 then serves to maintain panel 10 in the open position for the purpose of venting pressures due to secondary explosions. Arm 60 also serves to reinforce panel 10 against lateral movement and provide a rigid panel assembly.

The panel assembly of the invention is provided with a magnetic latch 18 so that it may readily be calibrated to open upon application of a predetermined pressure against surface 24 of panel 10. Preferably, a keeper 20 magnetically attractive material such as iron, nickel or a magnetic alloy is fastened to the outwardly moving side 68 of casement 28 at the midpoint thereof by a screw 70. However, where casement 28 is of magnetically attractive material, it will function as a keeper and the separate keeper 20 may be dispensed with. A bracket 72 is fastened to flange 40 of frame 12 by screws '74, in alignment with keeper 20. A permenent magnet 76 is preferably mounted to bracket 72 by means of a bolt 78, the head 80 of which is recessed within a slot 82 in the face of magnet 76 to permit direct contact between magnet 76 and keeper 20; bolt 78 is secured by a nut 84. Slot 82 extends completely through the sides of magnet 76 so that it, in effect, becomes a horse-shoe type having legs 76a and 76b of opposite polarity as shown in FIGURE 3.

A pull chain 86 is provided on latch 18 to facilitate the closing of panel 10. Chain 86 is fastened to side 68 of casement 28 adjacent keeper 20 and a loose end extends through an opening 88 in bracket 72 adjacent magnet 22; a pull ring 90 is provided on the loose end for the operators convenience.

In addition to being readily calibrated, magnetic latch 18 will maintain its magnetic attractive force constant over extended periods of time. As shown in FIGURE 3, when panel 10 is in its normal closed position, keeper 20 acts as a shunt between the opposite poles of legs 76a and 7612. As will be recognized by those skilled in the art, the provision of a shunt will maintain magnet 76 at a substantially constant strength, thus providing a reliable magnetic latch which will open at its calibrated pressure level even after long periods of non-use.

While only a single magnetic latch comprising one magnet and one keeper has been shown in a preferred embodiment, it will be understood that the panel assembly of the invention may include two or more such magnetic latches of similar or varying geometry and magnetic force where desirable for a particular application.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which as a matter of language, might be said to fall therebetween.

Having described my invention, What I claim as new and desire to secure by Letters Patent is:

1. A pressure venting panel assembly for an enclosure comprising, in combination:

(A) a panel (1) pivotably supported in an opening in said enclosure, and

(2) pivotable between open and closed positions,

(B) magnetic latch means calibrated to disengage upon application of a predetermined pressure below the rupture pressure of said enclosure and comprising (1) means forming a keeper of magnetically attractive material, and

(2) at least one magnet having legs of opposite polarity extended toward said keeper,

(3) said keeper and magnet each being on one of two adjacent surfaces of said panel and enclosure in position to magnetically engage and hold said panel in said closed position, whereby said keeper acts as a shunt to maintain said magnetic latch means at its calibrated value when said panel is closed, and

(C) means for maintaining said panel in an open position after application of pressure sufficient to disengage said magnetic latch means.

2. An assembly as defined in claim 1 wherein said panel comprises a window and wherein said magnetic latch means is calibrated to disengage upon application of a pressure below the breaking stress of the glass in said window.

3. A pressure venting panel assembly for an enclosed building comprising, in combination:

(A) a frame (1) mounted in an opening in said building,

(B) a panel (1) pivotably mounted in said frame and (2) pivotable between an open position wherein said opening is uncovered and a closed position wherein said opening is substantially sealed,

(C) a magnetic latch comprising a magnetically at- 5 6 tractive keeper, and a permanent magnet having legs secured to said panel to form said keeper and a permaof opposite polarity extended toward said keeper, nent magnet of the horse-shoe type mounted to said (1) each supported on one of two adjacent surframe on a bracket in alignment with said keeper when faces of said panel and frame, said panel is closed.

(2) said keeper being magnetically engaged 6. An assembly as defined in claim 5 and including a across both said legs of said magnet when said 5 pull chain for closing said panel secured to said panel panel is closed to hold said panel in said closed adjacent said keeper and extending loosely through an position and to provide a magnetic shunt, and opening in said bracket. (3) said latch being calibrated to disengage and allow said panel to open upon application of a 10 References Cited predetermined pressure to said panel, and UNITED STATES PATENTS (D) means maintaining said panel in an open position t after application of pressure sufiicient to disengage gg igg 11//19632 gZ P 2 5 said magnetic latch comprising a pair of linkage 1351 1 3/3 A 25;: T9- 31"*X arms, each pivotably connected at one end to one 15 side of said panel and at the other end to said frame adjacent the corresponding side of said panel. FOREIGN T Z 4. An assembly as defined in claim 3 wherein said 629,903 9/1949 Great Britain. panel is a window and wherein said magnetic latch is calibrated to disengage below the breaking stress of the 20 KENNETH DOWNEY=Prlmary Exammerglass in said window.

5. An assembly as defined in claim 3 wherein said magnetic latch comprises a magnetically attractive plate 49---3l, 252; 52-1; 292-2515