US3815312A

US3815312A - Bullet resistive door

Info

Publication number: US3815312A
Application number: US00233999A
Authority: US
Inventors: R Lench
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1972-03-13
Filing date: 1972-03-13
Publication date: 1974-06-11
Anticipated expiration: 1991-06-11

Abstract

A bullet-resistive door having a relatively thick heavy armor plate within the door interior, and a series of channel reinforcing ribs adhered to opposite faces of the armor plate to prevent it from buckling under its weight or door-slamming forces. The reinforcing channels also serve to locate and retain the outer door sheets in smooth, flat, non-wavy planes.

Description

loa -1B2a 5R United States Patent 1191 Lench June 11, 1974 [54] BULLET RESISTIVE noon I [75] lnventor: Robert Lench, Culver City, Calif. [73] Assignee: American Standard Inc., New York,

22 Filed: Mar. 13, 1972 [21] Appl. No.: 233,999

1521 115.01. ,.52/622,109/82 1511 1111. C1. E04c 2/08, E04b 2/02 [58] Field of Search ..109/8083,

[56] References Cited UNITED STATES PATENTS 1,129,041 2/1915 Malmberg ..-...l 52/455 2,086,571 7/1937 Novambere 52/612 2,256,375 9/1941 Bonsall 52/404 2,279,110 4/1942 Collins 109/82 2,410,022 10/1946 Dumais 52/612 3,453,074 7/1969 Gerard 109/83 FOREIGN PATENTS OR APPLICATIONS 911,099 2/1946 France 52/620 954,629 6/1949 France 52/618 148,152 12/1902 Germany 109/80 3/1943 Sweden 52/615 Primary Examinerl-lenry C. Sutherland Assistant Examiner-James L. Ridgill, Jr.

Attorney, Agent, or Firm-Jefferson Ehrlich; Robert G. Crooks 5 7] ABSTRACT A bullet-resistive door having a relatively thick heavy armor plate within the door interior, and a series of channel reinforcing ribs adhered to opposite faces of the armor plate to prevent it from buckling under its weight or door-slamming forces. The reinforcing channels also serve to locate and retain the outer door sheets in smooth, flat, non-wavy planes.

21 91 11 11.? preriie jiiae ee r 1 BULLET RESISTIVE noon SUMMARY OF THE INVENTION It is known 'to provide thick armor plate of hardened steel around vehicles ships, planes, and other similar structures. Apparently there have not previously been many attempts at providing thick armor plate within residential or commercial doors, such as in homes, apartments, hotels, elevators, motels or office buildmgs.

The present invention seeks to provide armor plate within the interior surface of a door. The plate is incorporated in the door in a stifiened condition by means of elongated vertical channels welded or otherwise adhered to the armor plate near the plate upper and lower edges. The channels act in tension as plate stiffeners and also as spacers for engagement with relatively thin ornamental sheets defining the outer faces of the door. Preferably the channels are provided with outtumed flanges which engage flatwise on the inner surfaces of the ornamental sheets to maintain the sheets in single flat planes without weaving or distorting.

THE DRAWINGS FIG. 1 is an elevated view of a bullet-resistive door embodying the invention;

FIGS. 2 and 3 are enlarged fragmentary sectional views taken on lines 2-2 and 3-3, respectively, in FIG. I;

FIG. 4 is an enlarged fragmentary sectional view taken in the same direction as FIG. 3, but illustrating a modified form of the invention;

FIG. 5 is a fragmentary sectional view taken in the same direction as FIG. 2 but illustrating another modification of the invention;

FIG. 6 is a fragmentary sectional view taken in the same direction as FIGS. 2 and 5, but illustrating a further form of the invention;

FIG. 7 is a fragmentary sectional view of a door of this invention having a bullet-resistant safety glass incorporated therein.

THE DRAWINGS IN DETAIL FIG. 1 shows a bullet resistive door of the invention having an upper edge 12, a lower edge 14 and two side edges 16. The door interior is occupied by a thickened armor, plate 20 having a number of vertical reinforcement rails or ribs 18 adhered to its opposite faces for stiffening the plate against buckling or bending in vertical planes. As shown in FIG. 1, each rib 18 extends substantially the entire vertical dimension of the door from a point near the lower door edge 14 to a point near the upper door edge 12. Each rib is preferably welded to the armor plate near the door upper and lower edges.

FIG. 2 illustrates the armor plate and stiffener ribs in greater detail. As there shown, the thickened steel plate 20 is enclosed within and between two relatively thin

ornamental sheets

22 and 24, also preferably formed of steel. Sheet 22 has its vertical edge 1.6a turned right angularly to make a conventional interlocking connection at 26 with sheet 24. The other non-illustrated vertical edge of sheet 22 would be similarly turned to form an interlocking connection with sheet 24. As shown in FIG. 3, the upper and lower edges of the two

ornamental sheets

22 and 24 may be joined together by means of a channel 28.

Armor plate 20 is solid and relatively thick, on the order of k inch thick or greater, so that the plate is comparatively heavy. In a standard size door the armor plate may weigh on the order of 300 pounds. With such a heavy weight there is a tendency for the plate to bend in vertical planes normal to the plate faces. This bending tendency may be especially prevalent in large doors on the order of 8 .feet high, particularly while the door is in the process of swinging against a door stop. To prevent such buckling or bending tendencies the armor plate is provided with a series of reinforcing rails or ribs 18, shown in FIG. 2 as channels 30.

Each channel 30 has its web wall 32 located flatwise against the face of armor plate 20, and its leg walls 34 extending right angularly from the web wall toward the

ornamental sheet

22 or 24. Each leg wall has outturned flanges 36 extending parallel to the web wall for flatwise engagement with the inner face of the

respective sheet

22 or 24.

As previously noted, each reinforcement channel 18 extends substantially the entire vertical dimension of the armor plate. The cross-section of each channel is uniform along its full length so that flanges 36 extend the full length of the channel for extensive engagement with

sheet

22 or 24. Preferably each flange 36 is welded to the respective ornamental sheet 22 or 24'at regularly spaced points along the length of the channel, for example on 4 inch centers. The aim is to provide multiple attachment points between each flange 36 and the ornamental sheet for minimizing any weaving, distorting or oil-canning of the sheet.

' Each channel 30 is preferably adhered to the armor plate 20 by means of two resistance welds 38 near the upper edge of the channel and two additional welds 40 (FIG. 3) near the lower edge of the channel. The channel areas between upper welds 38 and lower welds 40 are preferably not attached to armor plate 20.

One reason for not attaching the intermediate portions of each channel to the armor plate is to minimize the number of welds and thus the fabrication expense. The welding expense factor may be especially important when armor plate 20 is formed of high carbon steel which is difficult to weld without preheating or post heating procedures. When the resistance weld operations are performed only in the zones near the upper and lower edges of the plate it is easier to provide controlled supplemental heat necessary for slow cooling and avoidance of brittleness in the welded joints.

A further reason for attaching the reinforcing channels to the armor plate 20 only at points near the channel upper and lower edges is to provide relatively long channel lengths in tension when bending forces are applied to the channels. Thus, a longer channel length in tension means more material in tension and a greater resistance to elongation or failure of the channel. If the channels were welded to the plate at closely spaced points the channels might have insufficient strength to resist local tension forces in the zones between welds.

Leg walls 34 of the channels cooperate with web wall 32 and the areas of the ornamental sheets between flanges 36 to form hollow rectangular box sections. Such box sections are relatively strong; thus the

skin sheets

22 and 24 serve to enhance the structural rigidity of the door even though such sheets may be relatively thin, for example on the order of 0.03 inches. Each channel 30 preferably has a somewhat greater wall thickness than the ornamental sheets, for example a wall thickness on the order of 0.05 inches. Channel walls 34 preferably extend at right angles to web wall 32 for maximum resistance to bending strains.

FIG. 4

mal to the plate, i.e., horizontally in FIG. 4. According to the disclosure in U.S. Pat. No. 2,318,301, rubber block 44 would function as a resilient element to absorb at least some of the kinetic energy of the bullet.

l have confined by experimental work to devices along the lines of present FIG. 2, i.e., to devices using a thickened armor plate 20. However, it is believed that the invention would also be applicable or useful with armor plate formed as shown in FIG. 4. Stiffening of the armor plate 20a could be achieved by means of full length spacer channels or ribs 18a constructed similarly to the corresponding ribs 18 shown in FIG. 2.

FIG. 5

FIG. 5 illustrates a bullet-resistive door wherein the armor plate 20b is formed as a composite metalceramic assembly similar to that shown in U.S. Pat. No.

' 3,592,943 issued on July 13, 1971 to E. W. l-Iauck, et

al. As shown in FIG. 5 the armor plate consists of two

aluminum channels

48 and 50 enclosing a ceramic plate 60. As described in U.S. Pat. No. 3,592,943, the ceramic and aluminum components can be adhered together with an epoxy cement. Similar epoxy cements can be used to adhere the

aluminum channels

48 and 50 to the stiffening elements 18.

It will be understood that armor plate 20b has a width and height the same as that of the two

ornamental sheets

22 and 24. Also, the number of strengthening channels 18 will be approximately the same as the number of channels employed in FIG. 1 embodiment; however the lesser weight of armor plate 20b (compared to plate 20) may enable a somewhat lesser number of reinforcement channels 18 to be employed in the FIG. 5 structure.

FIG. 6

. generally similar to the construction of FIGS. 4 and 5 except for the makeup of the armor plate.

I FIG. 7

a FIG. 7 fragmentarily shows a door construction similar to that of FIG. 2 except that an opening is formed through the door for reception of a transparent bulletresistant glass 68. The opening in the door is framed by a peripheral frame member of T-cross-section As shown in FIG. 7, the peripheral frame 70 includes a first leg 72 extending normal to the plane of the 'door between

sheets

22 and 24, and a second leg 74 extend ing flatvvise on sheet 22. Frame 70 may be suitably secured to

sheets

22 and 24 bywelding, rivets, adhesives,

etc.

In fabrication of the FIG. 7 door the bullet-resistant transparent glass 68 is positioned against frame wall 74, after which a retainer frame element 76 is mounted on door sheet 24 to lockglass 68. in place. Peripheral frame element 76 may be mounted on sheet 24 by means of epoxy cement (permanent mounting) or screws, not shown (removable mounting). The FIG. 7 construction is similar to the FIG. 1 construction except that certain ones of the stiffener ribs 18 must be shortened to enable formation of the glass-reception opening.

FEATURES OF THE INVENTION A principal feature of this invention is the multiple reinforcement channels 30 adhered to the armor plate (20 or 20a or 20b or 200) to reinforce the armor plate against buckling or bowing in vertical planes. The stiffener channels additionally provide attachment services for the facing

sheets

22 and 24. The facing sheets are preferably attached to the channel flanges 36 at multiple points therealong so that the facing sheets act as structural components even though they are relatively thin and flexible when otherwise unsupported.

ll claim:

11. A bullet-resistive armored plate door comprising two relatively thin ornamental sheets defining the door outer faces; a solid relatively thick steel bullet resistive armor plate within the door interior in spaced relation to the ornamental sheets and extending substantially parallel thereto and substantially over the entire width of the door; and a plurality of pairs of parallel spacers,

the spacers of each pair being arranged on opposing faces of the armor plate and each adhered to one of the opposing faces of the armor plate and the adjacent ornamental sheet; each spacer consisting of a channel having a web-wall, two leg walls extending normal to the web wall and normal to the armor plate, and two flanges outtumed from each leg wall in parallelism with the web wall; each channel being positioned with its web wall facially engaged with the armor plate and with its outtumed flanges facially adhered to the adjacentornamental sheet; each of said channels being adhered to the armor plate solely by means of welds in areas near the channel upper and lower edges; said channels extending substantially the full vertical length of the armor plate and of the ornamental sheets; each of said channels being welded to its adjacent sheet and having a regular relatively uniform spacing across said sheet so that adjacent ones of the channel flanges have approximately the same horizontal spacing.

' l II

Claims

1. A bullet-resistive armored plate door comprising two relatively thin ornamental sheets defining the door outer faces; a solid relatively thick steel bullet resistive armor plate within the door interior in spaced relation to the ornamental sheets and extending substantially parallel thereto and substantially over the entire width of the door; and a plurality of pairs of parallel spacers, the spacers of each pair being arranged on opposing faces of the armor plate and each adhered to one of the opposing faces of the armor plate and the adjacent ornamental sheet; each spacer consisting of a channel having a web-wall, two leg walls extending normal to the web wall and normal to the armor plate, and two flanges outturned from each leg wall in parallelism with the web wall; each channel being positioned with its web wall facially engaged with the armor plate and with its outturned flanges facially adhered to the adjacent ornamental sheet; each of said channels being adhered to the armor plate solely by means of welds in areas near the channel upper and lower edges; said channels extending substantially the full vertical length of the armor plate and of the ornamental sheets; each of said channels being welded to its adjacent sheet and having a regular relatively uniform spacing across said sheet so that adjacent ones of the channel flanges have approximately the same horizontal spacing.