Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
The present invention relates to a device for
simultaneously reinforcing a door jamb and serving as an
engagement surface for the bolt (e.g. latch bolt or dead bolt)
of a door.
Conventional strike plates and dead bolt keepers
provide a narrow latching or engagement sur~ace which will
often bend or tear when a closed door is subject to an attack
force. When the strike plate bends or tears, very little
additional force on the door may be required to cause the latch
bolt or dead bolt to come loose from the receptacle in the door
jamb located behind the strike, thereby enabling the door to be
opened.
Patents of general background intecest describing
reinforcing means for keepers or strike plates include U.S.
Patent No. 2,533,396 issued December 12, 1950 of Payne, U.S.
Patent No. 4,186,954 issued February 5, 1980 of Detlefs and
U.S. Patent No. 4,211,422 issued July 8, 1980 of ~lansen. The
keepers and lock strike plate assemblies of these devices
require special, relatively complicated constructions. U.S.
Patent No. 4,369,994 of Vorves issued January 25, 1983
describes and illustrates a strike elate support comprising a
U-shaped, two-piece connection which bolts into a door jamb, to
circumscribe the upper, lower and outer peripheries of the
receptacle for the door latch or bolt. ~ stcike plate fits
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over this device and is secured to the door jamb by normal wood
screws. The device illustrated in this patent, in operation
produces significant bending stresses on the door latch or
bolt. Also, the hinge pin ~hich joins elements forming the "U"
is a ~oint at which the unit may structurally fail if subjected
to high impact forces.
Other patents of general background interest are
Canadian Patent No. 1,119,640 issued March 9, 1982, U.S. Patent
No. 3,767,245 issued October 23, 1973, U.S. Patent No.
4,195,780 issued April 1, 1980 and U.S. Patent Wo. ~,~7~,39~
issued October 2, 1984. Many of the strike plate sup~ort
assemblies of these patents have reinforcement means extending
in a direction perpendicular to the jamb surface and hence
per~endicular to the direction in which an attacking force to
the door might be applied.
SUMMARY OF THE INVENTION
In accordance with the present invention there is
provided a device for simultaneously reinforcing a door jamb
and serving as an engagement surface for the latch bolt of a
door. The device comprises an elongated flat structural member
of large lateral cross-sectional area. The member has a laege
flat longitudinally extending engagement surface for the bolt
to extend parallel to the longitudinal axis of the member. It
is mounted in the door jamb so that the engagement surface is
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properly positioned with respect to the bolt receptacle in the
door jamb and with respect to the latch bolt, to maintain
proper door closure. Long common fasteners extend through the
structural member in a direction ~erpendicular to the
engagement surface and into the door jamb, preferably at
locations equally spaced from the position of the latch or bolt
when seated in the bolt receptacle to hold the structural
member firmly in place in the jamb.
In a preferred embodiment of the present invention,
the device further comprises a thin sheet metal combination of
cover plate and strike, to be secured ~o the structural member
by securing means thereby to form an integral assembly.~
The device according to the present invention provides
a high strength universal type of replacement device for strike
plates and dead bolt keepers. The device, in a preferred
construction, forms an integral assembly with the cover plate
and strike, that is adjustably attached to a door jamb by means
of the long common fasteners. The device in addition to
serving as a very effective door jamb reinforcement, gives a
balanced high resistance in direct opposition to any attack
force against the door, when located close to the mounting
surface of the jamb. It is easily installed and economically
manufactured.
Accordingly, it is an object of the present invention
to provide a low cost high strength universal type of securing
mechanism applicable to most common frame jambs in new or
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existing housing, requiring only the simelest oE modifications
to the jamb itself for installation.
Another object is to provide a replacement aeparatus
tha~ will allow the removal and discarding of an existing
strike plate, and be surface mounted to completely cover the
cavity of the old strike plate.
Another object is to provide a mechanical design which
does not depend on the resistance-to--shearing st~esses in
fasteners or other small sections, for sueport against impact
forces.
Another object is to provide a cover plate that serves
in a way that is similar to a conventional strike, but does not
itself provide the latch engagement function to maintain door
closure. A further object of the cover plate is to conceal the
internal security mechanism and its jamb cavity.
A further object of the invention is to provide a
device which requires only a moderate degree of skill for
installation, and which may be quickly installed.
Another object is to provide an apparatus which is
capable of a simple readjustment at any time for optimum door
closure.
~ still further object for one embodiment of the
invention is to provide a strong body structure for the
attachment of a door chain during installation, or at a later
time as required by the user.
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Yet another object of this invention is to erovide a
simple mechanical assembly for easy manufacture, which may be
included in a package as part of a common lock installation kit.
BRIEF DESCRIPTION OF THE DR~WINGS
These and other objects and advantages of the
invention will become apparent upon reading the following
detailed description and upon referring to the drawings in
which:
FIGURE l i5 an e~ploded perspective view of a device
in accordance with the present invention mounted in a door jamb;
FIGURE 2 is a section view of the device taken through
~he door jamb, immediately above the device, along line II-II
of FIGURE 3; and
FIGURE 3 is an elevation view, partially broken away,
of the device of FIGURE l.
While the invention will be described in conjunction
with an example embodiment, it will be understood that it is
not intended to limit the invention to such embodiment. On the
contrary, it is intended to cover all alternatives,
modifications and equivalents as may be included within the
spirit and scope of the invention as defined by the appended
claims.
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DETAILED DESCRIPTION OF THE INVENTION
In the following description, similar features in the
drawings have been given similar reference numerals.
Turning to FIGURE 1 there is illustrated a device 2
for simultaneously reinforcing a door jamb and serving as an
engagement surface for the latch or bolt thereof, mounted in a
door jamb 4. Device 2 comprises an elongated flat structural
member 6, having a relatively large cross-sectional area in the
lateral direction. ~ large flat longitudinally extènding
engagement surface 8 extends along one side of member 6,
engagement surface 8 to be mounted in the door jamb, as
illustrated in FIGURES 2 and 3, so that it is properly
positioned, with respect to the latch or bolt receptacle 12 in
the door jamb 4, so that when the door is closed, it holds the
bolt or latch properly within the receptacle.
Member 6 is held in position by means of long common
fas~eners 14 which, in the illustrated embodimen~, are
elongated wood screws. These fasteners 14 extend through
structural member 6 in a direction perpendicular to engagement
sueface 8 into jamb 4 to hold structural member 6 firmly in
place in the jamb and resist any forces which might be applied
to the door ~o open it while closed or locked. Member 6, when,
thus held ~n position, distributes its load-carrying resistance
to impact forces symmetrically in the vertical and horizontal
planes. ~his is achieved, in the vertical plane, by the
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fasteners 14 having their center lines coincident with the
vertical center line of the structural member 6, and
horizontally by fasteners 14 being positioned, in member 6 at
locations equally spaced from the position of the latch or bolt
when positioned in the bolt receptacle 12 to give a balanced
resistance to an attacking force on the door (transmitted to it
by the latch or bolt).
~ cover plate and strike 16, comprising a thin piece
of sheet metal, is surface mounted on jamb 4 as illustra-ted,
using machine screws 18 extending through holes in cover 16
into threaded holes 19 in member 6. The heel corners of cover
16 are simply fastened to jamb 4 by means of ordinary wood
screws 20 as illustrated.
Flexible washers 22, mounted on fasteners 14 and
positioned between member 6 and adjacent portion of jamb 4, are
used to provide a resilient means for achieving a continuously
adjustable asse~bly for optimum door closure. ~fter adjusting
the lateral positioning of engagement surface 8 with respect to
receptacle 12, by means of appropriately rotating fasteners 14,
structural member 6 is then held firmly in place. If
necessary, plastic wood (not illustrated) may be forced into
the spaces between confronting surfaces oE jamb 4 and
engagement surface 8 in the vicinity of the compLessed rubber
washers 22.
For further security, a pluLality o~ wall pins 24
(FIGU~E 3) may be driven into pilot holes through jamb 4 into
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studs 25 to provide extra support and strength from the wall
structure.
Installation of the device is readlly achieved by
simply routing out a small portion of the front edge of door
jamb 4 and frame-to-wall cover strip 28 as illustrated in
FIGURE 1, for example with the aid of an appropriate guide
template, and drilling of horizontal eilot holes deep in the
door jamb for long Gommon fasteners 14. Holes in structural
member 6 may be used as a hole template for drilling these
pilot holes, while the assembly is hand held in place. Using
the small rubber washers 22 as previously described, the
structural member 6 may be appropriately laterally positioned
with respect to receptacle 12 for optimum door closure, and
plastic wood applied as previously described, if desired.
Cover plate and strike 16 is then connected in fixed relation
to structural member 6 with machine screws 18 and finally the
heel corners of cover 16 are fastened to the jamb by means of
wood screws ZO.
If desired, member 6 may be provided with a chain-
receiving fastener 30 or other such securing means, to which a
conventional interior door lock safety chain (not illustrated~
may be anchored.
Impact testing in general accordance with ASTM
F-476-76, of the device in accordance with the present
invention, has shown that, in addition to seLving as a very
effective door jamb reinforcement, the long common fasteners 14
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in conjunction with member 6 and its engagement surface ~ give
a balanced high resis-tance in direct opposition to any attack
force against the door, when the device is located close to the
mounting surface of the jamb.
Thus it is apparent that there has been provided in
accordance with the invention a balanced latch bolt keeper
support system that fully satisfies the objects, aims and
advantages set forth above. While the inven-tion has been
described in ~onjunction with a specific embodiment thereof, it
is evident that many alternatives, modifications and variations
will be apparent to those skilled in the art in light of the
foregoing description. Accordingly, it is intended to embrace
all such alternatives, modifications and variations as fall
within the spirit and broad scope of the invention.
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