WO2008062410A2 - Blast resistant assembly - Google Patents

Abstract

A blast resistant assembly having one or more reinforced panes mounted onto a sash having a pane engaging member, a sash frame and a plurality of energy absorbing devices (EADs). At least one of these EADs couples between the pane engaging member and the frame of the sash, allowing the pane engaging member to extend inside the frame upon impact transmitted by the pane. The EADs absorb a significant portion of the brunt of explosive forces thereby substantially reducing the transmission of forces to the frame of the assembly, sill and wall on which the assembly is installed, as well as the weight of the reinforced panes.

Description

BLAST RESISTANT ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to IL Patent Application Serial Number 179452 filed November 21, 2006, entitled "BLAST RESISTANT ASSEMBLY", the aforementioned application is incorporated herein by this reference.

FIELD OF THE INVENTION

The present invention relates in general to blast resistant structures and assemblies and in particular to blast-resistant covering for protection of an opening in a wall of a building from an external explosion.

BACKGROUND OF THE INVENTION

Blast resistant windows made of reinforced windowpanes and frames are common. The windowpanes and frames, typically made of steel, are normally heavy and therefore the manufacturing and installation of which is cumbersome and expensive. Furthermore, the brunt of an explosion may impart forces transmitted by such windows to the frames, windowsill or wall wherein the windows are installed, thereby causing damage thereto.

A UK patent application GB 2201183A1 and an international patent application WO 2004/072425A1 disclose blast resistant windows having damping elements. These damping elements are disposed between the wall or a window mounting structure attached to it, and the frame of the window. As a result a portion of the kinetic energy acquired by the reinforced panes and windows' frames during an explosion is absorbed.

International patent application WO 2005/014964A1 discloses a blast resistant window the frame of which has a rebate and panes that are releasably attached to the frame by flexible pieces. Such an attachment allows the pane to move within the rebate while absorbing a portion of its kinetic energy.

Confronting the international terror situation at present any improvements in the design and manufacturing of blast resistant windows is beneficial. In particular, blast resistant windows having thermally insulating frames which are relatively light weight and therefore of lower cost are called for.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a segment of a schematic sectional view of a blast resistant assembly of the present invention; Fig. 2 is a schematic sectional view of an exemplary sash of the present invention;

Fig. 3 is a segment of a side view of a cover wing according to a preferred embodiment of the present invention;

Fig 4 is a segment of a schematic sectional view of a blast resistant window according to another preferred embodiment of the present invention;

Fig. 5 is a segment of a sectional view across a plane parallel to the pane of the blast resistant window shown in Fig. 4;

Fig. 6 is a side view of a pane holding member of the left type attached to a segment of the windowpane of the blast resistant window shown in Fig. 4;

DETAILED DESCRIPTION OF THE PRESENT INVENTION

A blast resistant assembly for covering an opening in a wall and protecting enclosures, such as rooms or buildings, from explosive forces, bomb blasts and the like is provided in accordance with the present invention. The blast resistance assembly of the invention has one or more reinforced panes mounted onto a sash having a pane engaging member, a sash frame and a plurality of energy absorbing devices (EADs). At least one of these EADs couples between the pane engaging member and the frame of the sash, allowing the pane engaging member to extend inside the frame upon impact transmitted by the pane. Optionally at least one of the other EADs couples between the pane and the pane engaging member allowing the pane to further extend inside the pane engaging member upon an imparted impact. Optionally the frame of the blast resistant assembly is further coupled to the mounting structure of the assembly, which is firmly attached to the wall, by at least one additional EAD. Such EADs absorb a significant portion of the brunt of explosive forces thereby substantially reducing the transmission of forces to the frame of the assembly, sill and wall on which the assembly is installed, as well as the weight of the reinforced panes.

Reference is now made to Fig. 1 schematically showing a sectional view of segment 10 of a blast resistant assembly of the invention. Cover wing 12 consists of reinforced pane 14 and sash 16. Sash 16 consists of pane engaging member 18, sash frame 20 and a plurality of EADs. Cover wing 12 is either hinged or firmly secured to mainframe 22. Mainframe 22 is further mounted onto assembly mounting structure 24, which is secured to wall 26. Some of the EADs, such as EAD 28, couple between pane engaging member 18 and sash frame 20, allowing for a limited translation of pane engaging member 18 relative to sash frame 20 in a direction perpendicular to pane 14 away from the area of the explosion. Optionally EADs, such as EAD 30, couple between pane 14 and pane engaging member 18. Similarly EADs, such as EAD 32, couple between mainframe 22 and assembly mounting structure 24. Mainframe 22 further has two frame members 34 and 36 and a plurality of EADs, of which only EAD 38 is shown, coupling between them.

A sash frame or mainframe each according to the present invention may consist of one or more structural assembly members that are coupled by EADs. Reference is now made to Fig. 2 in which a sectional view of an exemplary sash is schematically shown. Sash frame 40 is coupled to pane engaging member 42 by means of EAD 43. Sash frame 40 consists of two structural assembly members: 44 and 45, which are coupled by means of EAD 46. Sash frame member 45 is further hinged or attached to the mainframe of the blast resistant assembly, not shown. Such sash provides for two independent translations in a direction perpendicular to the plane of the pane, which is represented by dashed line 47. Therefore, a blast resistant assembly of the invention provides for at least four different translations of which the first is of the reinforced pane, the second is of the pane engaging member, the third is of the mainframe as a whole and the fourth is either one of the structural assembly members (of the sash or the mainframe). All such translations are in the same direction, confined within limited ranges respectively and are independently provided by means of EADs. Each of these translations is independently associated with absorbing respective portion of the kinetic energy acquired by the pane or by sub-assembly structures or other sub units of the blast resistant assembly.

Reference is now made to Fig. 3 showing a segment of cover wing 48 according to a preferred embodiment of the present invention. Reinforced pane 50 consists of three layers. Pane 52 is sandwiched by panes 54 and 56. Pane 50 is made for example of transparent plastic resin, such as polycarbonate or casted polyurethane having respective predefined width. Exemplary panes 54 and 56 are made of 6 and 10 millimeters glass panes respectively. Pane 56 is exposed to the area endangered by an explosion. Reinforced pane 50 is releasably attached to the pane engaging member by means of EAD 57. Bolt 58 is inserted through a bore drilled into bracket 60 of the pane engaging member and through the lumen of tube 62. Pane 52 is fastened against the surface of bracket 60 by means of nut 64 and spacing tube 62. Tube 62 is made of deformable material, which crashes upon impact transmitted by pane 52 when its impact level exceeds a predefined threshold. Nut 64 also serves as a stopper limiting the translation of reinforced pane 50 in the direction of arrow 66.

EADs according to the invention provide for absorbing a portion of the kinetic energy acquired by the reinforced panes or sub-frames of the assembly during an explosion by transforming it into an elastic energy and/or mechanical work and heat. Such devices are typically made of elastic materials, which transform kinetic energy into elastic energy of deformation when compressed, twisted, bended or stretched. Springs of various shapes, staggered Belleville washers, high tensile strength tubular and/or strips of plastic or rubber, arranged in zigzag or structured such as honeycomb, may serve for this purpose as well. Similarly deformable plastic materials that crash under a load exceeding respective thresholds and or tensile cords or cables, which are stretchable up to a limit, such as of their tearing, are employable as well.

EADs according to the present invention can be more complex and also serve as structural elements of the blast resistant assembly. Sub-assembly units made of plastic resins such as polypropylene provide for absorbing energy when deformed. Brackets made of similar plastic resins connecting between adjacent sub-assemblies units may serve for the same purpose as well. Therefore, such connecting brackets or sub-assemblies are considered EADs according to the invention and are referred as such hereinafter. Employing such EADs further provides for thermal insulation due to the lower heat conductance of the plastic resins involved. An additional configuration of a complex EAD is further described in the example below.

EXAMPLE

A blast resistant window in accordance with a preferred embodiment of the invention is hereby described with reference to Figs 4 - 6. Such a window can be mounted on a main frame as described hereinabove. Alternatively the sash frame of this window can be connected either directly, or by means of EADs, to a wall, such as of a vehicle, providing for sheltering passengers and/or luggage from an external explosion. Cover wing 70 consists of reinforced windowpane 72, which is secured to pane engaging member 74. Pen engaging member 74 is coupled to sash frame 76 by means of EAD 78. EAD 80 couples between sash engaging frame 76 and windowpane 72 by means of one or more pane holding members such as pane holding member 82. Pane holding member 82 is firmly attached to pane 84 by means of bolt 86 and nut 88. Windowpane 72 consists of a polycarbonate pane sandwiched by 6 and 10 millimeter glass panes respectively indicated by 89 and 89A. Windowpane 72 is anchored to pane engaging member 74 by four cables respectively stretched along its edges, such as cable 90. Cable 90 passes through a hole disposed aside from the center of outwardly extending bracket 92, which is further secured to pane holding member 82. Wall 93 of the pane engaging member serves as a stopper as it is spaced apart from the end of bolt 82 and allows for a limited translation of windowpane 72 in the direction of arrow 94. The side of windowpane 72 exposed to the area endangered by an explosion is indicated by arrow 94.

In Fig. 5 a sectional view of segment 110 of the window wing described above is shown. Pane holding members 112 are secured to the central pane of windowpane 114. Cable 116 passes through holes drilled through the outwardly protruding brackets of pane holding members 112. Similarly, three additional cables, not shown, pass through holes respectively drilled in the brackets of the pane holding members secured along the other three edges of central pane 118. Both ends of each of the four stretched cables are respectively anchored to the pane engaging member. Optional one or two EADs, not shown, can be respectively connected between cable 116 and opposing walls of the pane engaging member. The pane engaging member is further coupled to the sash frame by means of EADs, not shown. Each of the four cables in combination with the pane holding members respectively engaged with them and the respective EADs attached to their ends constitute a combined EAD. The four combined devices collectively provide for absorbing a portion of the kinetic energy of the windowpane and/or sub units of the sash. Such combined EADs are also referred hereinafter as EADs.

In Fig. 6 a side view of pane holding 120 is shown attached to a segment of window pane 122. Holding member 120 is of a left type in which hole 124 is disposed left to the center of outwardly protruding bracket 126. Whereas holding member 82 shown in Fig. 4 to which reference is again made is of a right type in which such hole is disposed at the right side of the pane holding member. (Both pane holding members shown are oriented in the same direction, in which the bolt passes through them from the left to the right of the drawings). The arrangement of the pane holding members is such that those attached to the same edge of a windowpane are of the same type, say of the right type; and those attached to the adjacent edges are of the other type which is respectively the left type. By such arrangement cables stretched along adjacent edges of a windowpane are spaced apart from each other.

Claims

1. A blast resistant assembly comprising a sash for mounting at least one reinforced pane, wherein said sash comprises

• a pane engaging member;

• a sash frame engaged with said pane engaging member;

• a plurality of energy absorbing devices (EADs) for absorbing a portion of kinetic energy acquired by said at least one reinforced pane, and wherein at least one of said EADs is engaged both with said pane engaging member and with said sash frame.

2. A blast resistant assembly as in claim 1 , wherein a stopper is associated with at least one of said EADs for limiting translational motion in a direction perpendicular to said at least one reinforced pane.

3. A blast resistant assembly as in claim 1 , wherein at least one of said EADs comprises any material selected from a group of materials consisting of high tensile strength elastic materials, deformable plastic materials and any combination thereof.

4. A blast resistant assembly as in claim 1 , wherein at least one of said EADs comprises a spring, said spring selected from a group consisting of compression, bending, torsion, stretching, leafed springs and any combination thereof.

5. A blast resistant assembly as in claim 1 , wherein at least one of said EADs comprises at least two staggered Bellville washers.

6. A blast resistant assembly as in claim 1 , wherein at least one of said EADs comprises a cable, and wherein said cable is further connected to said pane engaging member.

7. A blast resistant assembly as in claim 1, wherein said reinforced pane is releasably attached to said pane engaging member, and wherein said reinforced pane is engaged with at least one of said EADs.

8. A blast resistant assembly as in claim 1 , further comprising a mainframe onto which said sash is mounted.

9. A blast resistant assembly as in claim 8, wherein said mainframe is engaged with at least one EAD.

10. A blast resistant assembly as in claim 8, wherein said sash frame is hinged to said mainframe.

11. A blast resistant assembly as in claim 8, wherein said mainframe comprises thermal insulating materials.

12. A blast resistant assembly as in claim 1, wherein said sash further comprises thermal insulating materials.