Safety door

To cause a door from being forced open or broken to gain access, a safety door comprises a central actuator and a plurality of bars radially extending at spaced apart locations from said central actuator sufficient in number and spacing to reinforce substantially the entire door. The central actuator is pivotally mounted within the door and each of the plurality of bars has one of its ends pivotally mounted to the actuator to cause the bars to be retracted or extended by rotation of the actuator. There are at least four bars with at least one bar extending in each of the four sides of the door framework.

BACKGROUND OF THE INVENTION

This invention relates to safety doors and more particularly to doors that resist forced entry from outside such as for example by forcing a deadbolt that is holding the door to the doorway frame to release or forcing the hinges from the door or doorway frame.

It is known to utilize multiple spaced apart deadbolts that resist forcible entry. This prior art technique has several disadvantages, such as for example: (1) the deadbolts only protrude a short distance into the frame of the door and thus can be forced free; (2) it is time consuming and inconvenient to individually move the deadbolts into place; and (3) the hinges can be forced out of the frame or the center of the door can be broken into such as by an axe.

U.S. Pat. No. 5,911,763 discloses a central actuator that moves a plurality of deadbolts into place at spaced apart locations around the periphery of the door through individual linkages, thus reducing the inconvenience of moving individual deadbolts into place one at a time. However, the lock disclosed in this patent relies upon linkages near the deadbolts at the periphery of the door that activate the three individual deadbolts and the deadbolts have only a short length within the door. It has several disadvantages, such as: (1) there are no deadbolts on the hinge side of the door so there are only a few short screws holding this side of the door in place against an impact that may pull the screws holding the hinges free; and (2) each of the linkage mechanisms includes three pivot points from the central actuator and provides little support for the door itself. Thus, in the case of some doors, an axe may be used to break the door itself.

It is known to use bars mountable on the inside of the door and held at several locations so that they extend across the door. While these bars provide overall strength, it is time consuming to put them in place and remove them when locking or unlocking the door. Moreover, they are unsightly.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a novel safety door.

It is a further object of the invention to provide a novel method for securing a door.

It is a further object of the invention to provide a novel door that resists forced entry from impact such as kicking, hitting with a sledge hammer or prying with crowbars or the like.

It is a still object of the invention to provide a door that resists entry by cutting or penetrating means such as saws and blowtorches and the like.

It is a still further object of the invention to provide a novel door with sufficient strength to resist entry over the entire entrance and yet may be opened and closed in a normal manner.

It is a still further object of the invention to provide a novel safety door without excessive external appliances such as extra cages or bars or the like that must be individually placed to prevent easy entry.

It is a still farther object of the invention to provide a relatively inexpensive yet strong safety door.

It is a still further object of the invention to provide a safety door that can be tailored to the needs in terms of strength and ability to easily lock and unlock it.

In accordance with the above and further objects of the invention, the safety door includes a central actuator and a plurality of bars extending substantially radially from the centrally located actuator sufficiently far to protrude into the frame of the door. In the preferred embodiment, the centrally located actuator is substantially cylindrical and rotatably mounted to a central location on the door. It pivotably receives one end portion of each of the bars at spaced apart locations. A turn of the centrally located actuator through a relatively short number of degrees forces the bars into the frame or withdraws them from the frame of the door. There are at least four radially extending bars and preferably six radially extending bars relatively evenly annularly spaced about the centrally located actuator so that substantially the entire door is reinforced by the bars and the bars extend a substantial distance into the doorway frame.

The door itself may be fabricated of any of several different materials including metal with a fire-resistant internal filling or a wooden frame with an internal powder filling or be entirely wooden. It has been found that it is most economical for the door to contain a large percentage of wood because this slows steel cutting saws. The door should also be sufficiently solid to support the centrally-located actuator and the radially-extending bars. For this purpose, the core of the door must be capable of being drilled and routered at least over a substantial area to allow placement of the component parts of the actuator and bars. One of the less expensive types of such doors is a frame filled with pressed wood particles. Cores of wood are hereinafter at times referred to as wooden door cores.

In fabricating the door, the door may be placed horizontally on a surface such as a table top. Drills on runners may be attached to the table or other surface and then caused to drill holes radially inwardly for the bars. At a central location where the drilled holes meet, an opening must be drilled through the plane of the door to support the rotatably mounted actuator on the inside of the door. In the preferred embodiment, the bars are internal to the door but it is possible to mount them externally by other slidable means on the inside of the door. However, in the preferred embodiment, access to the locking mechanism is provided only from inside the door and not from the external side. The openings for the bars can be accomplished with a router by forming the radial slots or by drilling. They should be slightly larger in at least one radial direction than the bars since they will move laterally to a slight extent as well as radially.

In the preferred embodiment, the central actuator is wheel-shaped and includes circumferentially spaced-apart metal pins perpendicular to the plane of the door. Each of the pins connects the opening in an end portion of a corresponding rod to a circumferentially spaced pin opening in the actuator. Preferably, there are four or more such pins and six or more rods. The radial movement of the pins with the centrally located actuator moves the rods outwardly and inwardly. The end plate on the wheel conceals the pins and the end connections in the preferred embodiment. In one embodiment, a handle is provided to actuate the wheel from the outside. The handle may contain a lock or may be removable to provide security.

Two problems had to be solved to provide an easy to use, adaptable safety door.

Firstly, because the bars that serve as deadbolts and reinforcement for the door are actuated by a rotary actuator, they move both longitudinally and at an angle to their longitudinal axes within a solid door in a plane parallel to the doorway. Thus the door must include unsymmetrical openings in the door, door frame and floor with space at an angle to the longitudinal axes of the rods within a plane parallel to the doorway to permit movement of the bars. Secondly, the actuator must be easily rotated by hand even though it may move several long bars along frictional paths in some applications. Once these two unobvious problems were appreciated, they were solved by designing the safety door so that a minor amount of rotation in degrees would move a sufficient number of bars a sufficient distance into the doorway frame and/or floor to provide the required strength and an adequate mechanical advantage was obtained by proper selection of the actuator diameters. The diameters are the diameter of the circle of rotation of the handle of the actuator and the circle of rotation of the driving element for the bars.

From the above summary, it can be understood that the safety door and method of securing a door of this invention has several advantages, such as: (1) it has overall strength so as to resist battering by any mechanisms at any place; (2) it is difficult to locate and to break the points of attachment of the door and the frame; (3) the points of attachment and reinforcement are throughout the periphery of the door and within the overall area of the door so as to provide relatively few weak portions; (4) it is easy to operate the door in a normal manner; and (5) the door is relatively inexpensive. Even with cutting the rods, the locking arms will extend into the frame, thus preventing opening.

DETAILED DESCRIPTION

InFIG. 1, there is shown a simplified fragmentary elevational view of a combination10of a safety door12, a doorway frame14, and a building wall16mounted together with the door12being a safety door. The safety door12has within it a centrally located actuator24, a plurality of rods or bars26A-26F, three hinges18A-18C and a door knob22. In the embodiment ofFIG. 1, the central actuator24is rotatably pinned to the door by a pin28(FIG. 2). The rods26A-26F are in communication at one of their ends (hereinafter referred to as a first end) with the actuator24so that rotation of the actuator24in one direction (clockwise in the embodiment ofFIG. 1) forces the rods outwardly into the doorway frame14and/or floor to lock the door and rotation in the other direction (counterclockwise in the embodiment ofFIG. 1) withdraws the rods26A-26F from the frame14or floor so that the door12can be opened. The actuator24is activated in the preferred embodiment by gripping the edge31and moving it through an arc. However, other handles can be used as shown in the embodiment ofFIG. 7and described hereunder.

When the door12is closed, the bars26A-26F resist the forcing of the door open. For this purpose, the bars have a thickness of at least 6 mm in their thickest dimension at an angle to their longitudinal axes, have a modulus of elasticity of at least 5,000,000 psi, and a yield point of at least 1,000 psi. In the preferred embodiment, they are solid aluminum cylindrical bars having a diameter of 12 mm but may be of many other materials and sizes. In the preferred embodiment, there are six rods although there may be between four and ten rods. With this arrangement, it is difficult to batter the door down. It can be secured from inside the building by simple rotation of the actuator24in one direction and can be placed in a rest condition where the door can be opened by simple rotation in the other direction of less than 90 degrees. In the preferred embodiment, the rotation is between 5 and 40 degrees. In most designs for doors, the rotation needed to insert the bars one inch into the doorway frame and a joist58in the floor is approximately 13 degrees and the angle increases in a manner substantially but not exactly proportionally to the distance.

InFIG. 2, there is shown a simplified, fragmentary partially sectional side view of the actuator24, door12and rods26A-26F (rods26A,26C,26E and26F only being shown inFIG. 2). As shown in this view, the actuator24includes two flat circular parallel spaced apart end plates30and32and a handle31. It is mounted within a front face10A and a rear face10B of the door12. The handle31in the embodiment ofFIG. 2is a wheel connected to the center of the end plate30by a pivot pin or connecting rod28that extends through a hole in the rear face10B of the door12for rotation with the end plates. However, the edge of an end plate could serve as the handle with access being provided to the edge through an opening in the door or the handle may have another shape such as being L-shaped. The actuator rods26A-26F are pivotally connected between the end plates30and32so that they are moved by rotation of the end plates30and32. The end plates30and32rotate between two centrally located bearing plates46and48on the inside of the front and rear faces10A and10B respectively of the door12.

The rods26A-26F (only rods26A,26C,26F and26E being shown inFIG. 2) are pivotally connected to the actuator24by six cylindrical equally spaced apart tubular posts34A-34F (not shown inFIG. 2between the end plates30and32. Although, in the preferred embodiment, the actuator24is cylindrical, it may take any other shape that can be moved to actuate the bars26A-26F (FIG. 1). In the preferred embodiment, the actuator24is designed to actuate six bars and for that purpose each of the equally spaced apart cylindrical tubular connecting posts34A-34F (not shown inFIG. 2) fits within a corresponding one of openings21A-21F (not shown inFIG. 2) in corresponding ones of right regular parallelepiped bosses20A-20F (only20A,20F and20E being shown inFIG. 2). In the preferred embodiment, the posts34A-34F are 0.5 inches aluminum tubes, the plates30and32are 8¾ inches in diameter and the posts are set in from the periphery by ¼ inch.

The ease of rotating the actuator24is reduced by the length of the rods and the number of the rods and increased by any mechanical advantage provided. The mechanical advantage is: (1) increased by the ratio of the distance of the handle31from the center of rotation to the distance of the ends of the rods26A-26F from the center of rotation; (2) reduced by the sine of the angle between the rods26A-26F and the radius of the center of rotation of the posts34A-34F; and (3) increased proportionally to the diameter of the circle of rotation of the posts34A-34F.

InFIG. 3, there is shown a fragmentary, exploded perspective view of a portion of the actuator end plate30, a portion of the actuator end plate32, one of the posts34A, one of the rods26A having a corresponding boss20A and a machine screw36A. The post34A fits within an opening21A and thus holds the rod26A pivotally to the end plate30. An opening54in the end plate32is aligned with an opening35A in the post34A. The opening35A is tapped and a machine screw36A holds the end plate32, the boss20A, the post34A and the end plate30together. In the preferred embodiment, the rods are solid cylindrical 12 mm (millimeter) aluminum bars. The rods are relatively inexpensive and light in weight for easy assembly to the actuator.

InFIG. 4, there is shown a simplified perspective view of the rod26A, the end plate30, the end plate32and the screw36A showing the parts ofFIG. 3assembled together. Thus, the rods26A-26F are pivotally bolted at locations that place the rods26A-26F within the doorway in the preferred embodiment or inside the room into which the safety door12opens. The machine screw36A has a head larger than the opening54(FIG. 3) in the end plate32. Each of the rods26A-26F is connected to a corresponding one of the posts34A-34F in a similar manner. This manner of connection permits the rods26A-26F to move in a plane parallel to the doorway and outwardly within slightly elongated slots in the door and door frame. Although a specific mode of connection has been described, there are many other modes possible and known in the fastener art and the universal joint arts.

InFIG. 5, there is shown a simplified fragmentary exploded perspective view of the actuator24with the six rods26A-26F being adapted to be pivotally mounted between the end plates30and32with their respective central cylindrical openings21A-21F in the corresponding bosses20A-20F receiving the cylindrical posts34A-34F. With this arrangement, as the actuator24rotates with the pivot pin28in the safety door12, the bosses20A-20F orbit about the pivot pin28and rotate about the corresponding posts34A-34F over which they fit. To hold the end plates30and32together, the posts34A-34F are attached to the end plate30and receive their corresponding machine screws36A-36F in their tapped holes. The screw heads are outside of the actuator24and their shanks extending through the openings50A-50F in the end plate32so that the end plate32is held to the posts34A-34F to confine the bosses20A-20F within the actuator24.

InFIG. 6, there is shown a simplified perspective view of the actuator24showing the manner in which the actuator24is held together with the pivot pin28extending outward from the end plate32to rest moveably against the bearing plate46(FIG. 2). The bearing plate48(FIG. 2) has a central opening to permit the pivot pin to extend to the handle31(FIG. 2) for rotation therewith.

InFIG. 7, there is shown a fragmentary elevational sectional view of the actuator24and door12taken through lines7-7ofFIG. 2having the end plate30, rods26A-26F, pivot pin28, door12and slots27A-27F through which the rods26A-26F extend. The slots27A-27F are vertically elongated to permit the rods26A-26F to move both radially outwardly from the actuator24through the door12and into the door frame14(FIG. 1) and floor joist58(FIG. 1) and at an angle to their longitudinal axes. This is necessary because the actuator24moves the inner end of the rods26A-26F in an orbital curved path rather than only linearly along the direction of their longitudinal axes.

InFIG. 8, there is shown a simplified perspective view of an embodiment of handle31A and an end plate30A for an actuator in accordance with an embodiment of the invention. In the embodiment ofFIG. 8, supporting bars50A-50D are connected to the end plate30A and the handle31A is connected to the supporting bars50A-50D. The supporting bars50A-50D meet at the center of the end plate30A opposite from the pivot pin. The pivot pin is welded at the opposite side of the end plate30A and extends perpendicularly therefrom through the opposite end plate to rest against a bearing plate in a manner similar to the embodiment ofFIG. 1. The handle31A extends perpendicularly from the intersection of the supporting bars50A-50D to which it is welded through the back face of the door12and ends in a handle at an angle to the perpendicular to provide mechanical advantage sufficient to permit easy turning of the actuator24to lock the door.

InFIG. 9, there is shown a simplified perspective partly exploded away view of another embodiment of door12A similar to the embodiment10ofFIG. 1but being adapted to be locked and unlocked from outside the door. Generally, it is preferable to utilize the embodiment ofFIG. 1for security reasons, but under some circumstances it may be desirable to secure the door from outside against battering. For this purpose, a key38is provided in the form of a crank having a handle60for leverage. The key38is insertible through the front (outer) wall of the door12A into an actuator24A which is modified to receive the key38. With this embodiment, the rods26A-26F may be retracted or extended utilizing the key38.

As best shown inFIG. 9, openings54A-54F at the locations where the slots27A-27F (herein sometimes referred to as laterally extending door slots) exit the safety doors12and12A ofFIGS. 1 and 9, are elongated in a plane parallel to the plane of the doorway. A corresponding one of the bushings56A-56F is inserted into each of the openings54A-54F. The bushings56A-56F and the openings54A-54F (herein sometimes referred to as doorway openings) in the doorway frames also have elongated slots. The elongated slots27A-27F are necessary to accommodate the motion of the rods26A-26F as the inner ends at the bosses20A-20F (FIG. 7) are moved in an arcuate path by the actuator24. The larger the angle through which the actuator24rotates the larger the slots must be. The angle is affected by the diameter of the circle formed by the posts34A-34F (FIG. 5) which is selected to determine the mechanical advantage obtained by rotating the larger diameter handle31. The distance the rods26A-26F move into and out of the doorway frame14(FIG. 1) is determined by the angle of rotation of the actuator24and the diameter of the posts34A-34F (FIG. 9). The bushings and slots are best illustrated at56D,52D and54D where the bushing56D is shown exploded away from the opening54D.

InFIG. 10, there is shown the key38and an embodiment28A of pin for the actuator24A (FIG. 9). The pin28A has on its end a uniquely shaped point which is shaped to correspond to the key38. The key38has an opening42with a shape to match the uniquely shaped end40and thus permit engagement uniquely between the key38and the pin28A for turning the pin to retract or extend the bars26A-26F (FIG. 9) and thus lock or unlock the door12A.

InFIG. 11, there is shown an elevational, fractionated sectional view, partly broken away, of another embodiment of actuator24B having end plates30B and32B, rods52A-52F, and a pivot pin28B. The end plate32B includes cut away portions showing the end plate30B. The rods include flattened ends62A-62F pivotally pinned to the end plate30B. With this arrangement, the handle31A (not shown inFIG. 11) may be rotated to lock and unlock the safety door. The rods are rotatably pinned directly to the actuator plate, thus reducing the depth of the actuator.

In operation, the safety door12is secured against battering or breaking to gain entrance to a room by turning the actuator24in a first direction and unlocked by turning it in the opposite or second direction. Turning the actuator24in the first direction moves the bars26A-26F in a radially outward direction from their central location around the actuator24a sufficient distance so that their ends (herein sometimes referred to a second ends) extend into the doorway frame14far enough to prevent the door from being forcibly dislodged from the frame of the doorway. When locked, the safety door12resists breaking or cutting to gain entrance into a room. Turning the actuator in the second direction retracts the ends of the rods26A-26F from the doorway frame14and permits the door to be opened by swinging it on its hinges18A-18C such as by the door knob22. In this specification, the floor including the joist58at the bottom of the doorway is considered part of the doorway frame14. The bars26A-26F extend at least one inch but preferably 1½ inches or more into the doorway frame14at six spaced apart locations on the door and extend all the way to a common point at an actuator24at the center so as to perform reinforcement throughout the door.

To permit the easy turning of the actuator24by hand to lock or unlock the door12, the actuator24is pivotally pinned to the door12by the pin28(FIG. 2) at a central location on the door12. A handle31(FIG. 2) extends from the actuator24inwardly into the room far enough to be easily grasped to manually turn the actuator. In the preferred embodiment, the handle31is “L” shaped but may be wheel shaped as shown inFIG. 2or any other shape that can be easily grasped is adequate.

The handle is spaced at a sufficient distance from the pin28about which it and the rods26A-26F rotate to provide enough mechanical advantage for easy turning against the resistance to motion of the bars. The larger the number of bars and the greater the length, the greater the resistance and the larger the distance between the pin28and the handle31to which force is applied to lock or unlock the safety door12. The mechanical advantage is the ratio between a first distance, which is the distance between the handle31and the pin28, and a second distance which is the effective distance between the points at which the inner ends of the bars26A-26F are attached to the posts34A-34F. In the preferred embodiment, the bars26A-26F are all pivoted about points that are at the same distance from the pin28and so the effective distance is the actual distance. However, in this specification, the effective distance is that distance that would provide the same mechanical advantage if the distances were all the same and the resistance to motion provided by each bar is the same. If the resistance provided by each bar is the same, the effective distance is generally the average distance.

In the preferred embodiment, the actuator24is rotated through 15 degrees in a first direction to lock the door and 15 degrees in the opposite direction to unlock the door. However, it may be designed for different amounts of rotation depending on the distance into the doorway frame the rods26A-26F are to extend and the diameter of the rotary member. In one embodiment, the door is only locked and unlocked from inside. However, in other embodiments, a key38with a hollow specific shape on its outer end may be inserted through the door into a special pin28A with a correspondingly shaped end so as to move the actuator24from outside the door. The pin is fastened to the plates30and32for movement therewith.

Although a preferred embodiment of the invention has been described with some particularity, many modifications and variations in the invention are possible in the light of the above teachings. Therefore, it is to be understood, that, within the scope of the appended claims, the invention may be practiced other than as specifically described.