Patent Application
20090282745
The present invention relates to door reinforcement assemblies and in particular to reinforcement of door frames and door jambs in order to reduce the risk of a forced entry attempt
A door jamb is the vertical portion of a door frame onto which a door is secured. Most types of door fasteners and deadbolts extend into a recess within the door jamb when in the locked position, making the strength of the door jamb and door frame vitally important to the overall security of the door.
Given an actual door width, the limited area on the door in which to install the dead bolt, and that the door itself is installed flush to the door jamb, the corresponding hole (recess) to accept the dead bolt ends up being located extremely close to the edge of the door jamb, making this area the weakest part of the door assembly. This is due to the fact that the remaining wood left between the recess and the edge of the door jamb is relativity small, in most cases just over ¼ inch
When the door is struck with a force, this force is transferred from the door to the dead bolt or latch bolt, which when inserted into the door jamb, transfers that force onto the wooden jamb With a large enough force, the door jamb breaks allowing forced entry to occur. Traditionally, in order to reinforce the jamb, a metal plate, called a strike plate, is mounted with screws onto the jamb itself vertically between the door jamb and the door The strike plate has an opening which is similar in size as the recess inside the door jamb However, moderate forces can still break the door jamb even with different size strike plates installed
Numerous door reinforcement assemblies have been invented in order to protect doors and prevent breaking of a door jamb Many of the reinforcements are variations of the strike plate. These types of reinforcements are mainly fastened to the bolt receiving face of the jamb For instance, U.S. Pat No. 5,456,507 issued to Jones discloses a strike plate assembly having numerous pins that extend through the door jamb and into the door support structure behind the door jamb. U.S. Pat. No. 5,241,790 issued to Schimpf disclosed a plate mounted on the face of the jamb, in the space between the jamb and the door frame. In order to install the reinforcing plate behind the door jamb, the interior trim strip is removed from the door frame and the reinforcing plate is mounted behind the door jamb Some of the door reinforcement assemblies are fastened to the sides of the jamb U.S. Pat. No. 4,074,484 issued to Queren, discloses a plate which is screwed to the wall studs and the door frame side rail. If a door is struck hard, the screws will pop and door opens Reinforcements can also be affixed to both the face and the sides of the jamb For instance, U.S. Pat. No. 6,857,672 issued to Drew discloses a U shaped piece which is installed on the face of the jamb The sidewalls which extent to the sides of the jamb include holes for fastening the piece to the door frame. U.S. Pat. Nos. 6,085,465, 6,305,127 and 6,430,876 issued to Olberding disclose a strike plate with an additional plate projected transversely from the flat surface plate Said transverse projection locates alongside of the door jamb and it can be screwed into the door jamb for reinforcement U.S. Pat. No. 5,566,509 issued to Long discloses an elongated reinforcement strip having an L-shaped transverse cross-section of one short leg and one long leg, the long leg for mounting on a door jamb face and the short leg for mounting on a door jamb edge U.S. Pat. No. 4,858,384 issued to Blankenship discloses an elongate support plate having an L-shaped cross section with a first side to overlap the inside of a door jamb and a second side to overlap the front of a door jamb. And U.S. Pat. No. 5,070,650 issued to Anderson discloses a flat elongate metal plate adapted to overlie a portion of the inner bolt receiving face of a door jamb and a thin elongate metal plate having an L-shaped cross-section and including a first side adapted to overlie the first metal plate and a second side adapted to be slidably inserted beneath the decorative molding and the outer face of the door jamb.
U.S. Pat. No. 4,416,087 issued to Ghatak, discloses reinforcing rods positioned internally along the depth of a door jamb adjacent the bolt receiver or striker plate. The rods use a brace bar positioned on the edge of the door jamb. The brace bar is exposed once the door is opened. Ghatak's invention requires modification of the door frame in order to be installed. The door trim must be removed, the bars are installed, then modification to the door trim is made, and then the modified trim is re-attach to the door jamb. In addition, it is not concealed, located between the door jamb and door trim, and will be obvious from the outside once the door is opened.
One advantage of the present invention over the prior art is that once installed, the device is concealed and therefore cannot be seen from the outside But its more important advantage is that there is no need to make any major modifications to the exiting door assembly. It can be installed on any wooded door jamb without removing any part of the door frame, door jamb or its decorative trim.
The prior art taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention relates to a door jamb reinforcement assembly and a method of installing reinforcements into door jambs An object of the present invention is to reduce the risk of breaking a door jamb and therefore allowing a forced entry attempt. Another object of the present invention is to provide a reinforcement assembly that can be implemented on any of the existing door jambs, mainly wooded door jambs, with minimal modification and without a need to replace the lock, jamb or decorative trim Another object of the present invention is that it can be installed in a very short time, reducing the retrofit and installation cost
The reinforcement assembly of the present invention comprises of a reinforcement plate, made or a metal of any other high strength material, which is inserted directly into the door jamb perpendicular to the lock receiving face of the door jamb. The reinforcement plate is wide enough to extend into the depth of the door jamb, and it is long enough to extend pass the latch and lock receiving recesses inside the jamb The plate also has at least two apertures at its two edges to receive reinforcing bolts The door jamb is then reinforced by bolting the door jamb and the reinforcement plate together using bolts inserted into the interior side of the jamb in the parallel direction to the face of the jamb. The bolts extend only partly through the width of the door jamb, and not all the way through The bolts are then secured by nuts, preferably barrel nuts
It is therefore an object of this invention to provide a door jamb reinforcing means which overcomes the prior art deficiencies The main object of the present invention is to keep the door jamb or the door frame under stress and tension Increased tension in the wood result in an increase in its strength against attempts to break it It is also an object of this invention to have a reinforcement that is concealed, universal to fit all wood framed doors and easy to install. Most of the disclosed door reinforcement assemblies are very obstructive and undesirably prominent The prior art has not attempted to conceal the reinforcement assembly without sacrificing reinforcement strength
Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
In the figures, which illustrate, by way of example only, embodiments of the present invention,
The object of the present invention is to disclose a method and an assembly to reinforce door jambs. The method can be implemented on any existing wood door frame with a lock. The method comprises of first scribing a line parallel to the inside hole of the original strike plate The original strike plate is then removed The installation template is now secured onto the outside of the door jamb with screws which will also now provides alignment holes that are used to drill out the section to accept the bolts. Once the template is installed, a pre-defined slot is routed into the door jamb with certain depth, certain length and certain thickness. The depth of the slot is just enough to countersink and therefore conceal the metal reinforcement plate which will be inserted within this slot. This method also allows for the utilization of the door frame for strength as well The slot is long enough to receive at least two bolts, whereas the bolts pass below and above the dead bolt recess in the jamb. Next, two holes are drilled horizontally through the door jamb used to accept the bolts The drilled holes go through the recently created slot in the door jamb, preferably close to the two ends of the slot Once completed, the template is removed and the two screw holes that remain from the template removal are now made larger by drill to accept the receiving nuts. Then a plate preferably made of a reinforced metal or any other strong material, cut to the size of the slot on the door frame and having at least two apertures, is inserted into the slot The apertures in the plate have to be aligned with the apertures inside the door jamb. At least two bolts are inserted into the apertures of the door jamb and through the apertures of the plate At least two nuts are inserted into the aperture of the other holes which are used to tighten the bolts The nuts are positions in the interior of the door jamb, where there is no access and no way of removal A new strike plate is now installed back in place of the original but completely covering the metal plate insert while still allowing for the recess opening in the door jamb. The surfaces of the remaining openings can be capped with custom caps or filled with wood fillers for concealment. The heads of the bolts are also hidden under custom made caps so that they are not visible from the outside The method described here makes the door frame strong enough that it cannot be easily broken into
A more detailed description of a preferred embodiment of the present invention is provided by referring to
In another embodiment of the same invention, as shown in
