EP0892881B1

EP0892881B1 - Door brace

Info

Publication number: EP0892881B1
Application number: EP97915230A
Authority: EP
Inventors: James Elliott
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-04-11
Filing date: 1997-04-10
Publication date: 2003-06-25
Anticipated expiration: 2017-04-10
Also published as: AU2284097A; CA2251083C; CA2251083A1; WO1997038197A1; DE69723064T2; DE69723064D1; EP0892881A1

Description

This invention relates to a brace for securing a door in either a closed, or a partially open position, and for moving the door securely and forcefully from a partially open position to a closed position.

To protect people and valuables in buildings or rooms against forced entry, lockable doors are used. Various types of locks may be used to secure a door in the closed position. Typically, a lock secures the free edges of the door to the door frame using one or more deadbolts. Such a lock provides no support for the door itself, and the central portion of the door may be broken if subjected to blows. Such a lock also must be completely disengaged in order partially to open the door, and once the door is partially opened (for example, when an occupant wishes to speak to someone at the door or to receive a package), it is relatively easy for an intruder to force the door open further to gain entry.

To brace the door and to secure the door in the closed position, a cross brace may be placed horizontally across the door and secured on either side of the door to the door frame or wall.

Alternatively, an angle brace may be used to support the door and to secure it in the closed position. one end of the angle brace is attached to the door at a distance from the free vertical edge of the door, typically near the door handle. The other end of the angle brace is attached to the floor at a distance from the door such that the angle brace lies at an angle sufficient to brace the door shut. An angle brace may be constructed so as to be adjustable in length by using a tube or bar that is slidable within a second tube of slightly larger diameter. A series of holes are drilled through both, and a pin or bolt is placed through matching holes to fix the length of the angle brace before attaching it to the door or floor.

However, like conventional locks, cross braces and angle braces must be disengaged prior to partial opening of the door.

Prior art door braces including additional features are disclosed in GB-A-2,188,676 and US-A-4,070,049.

US-A-4070049 describes a door brace for bracing a door against a fixed object and for controlling movement of the door between a first at least partially open position and a second closed position. The door brace comprises an elongate member of variable length, axially moveable between a first length and a second length. It includes a first anchor means constructed and arranged to secure in both axial directions a first end of the elongate member to a door and a second anchor means constructed and arranged to secure in both axial directions a second end of the elongate member to a fixed object. There are also energy storage means for exerting an axial force on the elongate member, biasing the elongate member toward the second length.

To secure the door in a partially open position, a door chain may be used. However, a door chain is generally not strong enough to withstand a forceful blow. If the chain used is strong enough, it is usually impossible to attach the chain strongly enough to the door and door frame to withstand a forceful blow to the door. Another limitation of a door chain is that it provides no support to the door, and it can be severed once the door is partially opened.

A door stop may also be used to prevent a door from moving. While it is possible to build a door stop that will withstand forceful blows to the door, the door itself is placed in a weak position since it is supported only by hinges and by the door stop under the lower edge of the door.

An object of the present invention is to provide an improved door brace for bracing a door against a fixed object and for urging the door toward a closed position.

According to the invention, there is provided a door brace for bracing a door against a fixed object and for controlling movement of the door between a first at least partially open position and a second closed position, the door brace comprising: an elongate member of variable length, axially moveable between a first length, corresponding in use to the door being partially open, and a second length, corresponding in use to the door being closed; a first anchor means constructed and arranged to secure in both axial directions a first end of the elongate member to a door; a second anchor means constructed and arranged to secure in both axial directions, a second end of the elongate member to a fixed object; and energy storage means for exerting an axial force on the elongate member biasing the elongate member toward the second length; characterised by: a manually operable control mechanism adapted so as: to receive a manually applied first input force and simultaneously to generate a first output force urging the elongate member toward the first length, and a second output force greater than the first input force, the second output force acting on the energy storage means so as to increase the axial force on the elongate member; and to receive a manually applied second input force and simultaneously to generate a third output force greater than the second input force, the third output force urging the elongate member toward the second length.

The invention may be carried into practice in various ways and some embodiments will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a door brace in the retracted position, attached to a door and to a floor;

Figure 2 is a perspective view of the door brace of Figure 1 in the extended position;

Figure 3 is a partial perspective view the door brace of Figure 1 without the head and foot assemblies;

Figure 4 is a perspective view of the foot assembly of the door brace of Figure 1;

Figure 5 is a perspective view of the head assembly of the door brace of Figure 1;

Figure 6 is a top plan view of a second door brace in the retracted position;

Figure 7 is a side elevation view of the door brace of Figure 6 in the retracted position;

Figure 8 is a side elevation view of part of the door brace of Figure 6 showing the foot assembly;

Figure 9 is a side elevation view of part of the door brace of Figure 6 showing the head assembly;

Figure 10 is a partial perspective view of a third door brace without the head and foot assemblies;

Figure 11 is a perspective view of a fourth door brace;

Figure 12 is a perspective view of part of a fifth door brace; and

Figure 13 is a perspective view of part of a sixth door brace.

Similar references are used in the Figures to denote similar components.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figures 1 through 5, a door brace 5 includes an outer tube 10 and an inner bar 15. The outer tube 10 includes two tubular sections 11 and 12, which are rigidly but detachably attached together to function as one tube. The two tubular sections 11 and 12 are detachable for easy packaging and shipping. The inner bar 15 is a sliding fit within the tube 10. The common axis of the outer tube 10 and inner bar 15 is indicated at 17.

Each of two connectors 20 is attached at one end to the inner bar 15 with a first pin 25, and at the other end to one of two discs 30 with a second pin 35. The discs 30 are rotatably attached to the outer tube 10 through the axle 40. Preferably, the axle 40 is rotatably mounted within a sleeve (not shown) which passes through and is attached to the outer tube 10. Rotation of the discs 30 causes movement of the connectors 20, in turn causing axial movement of the inner bar 15 relative to the outer tube 10. Alternatively, the brace 5 could, for example, be designed with one disc 30 and one connector 20. However, the double disc design of the illustrated embodiment is advantageous in that it is balanced, strong and facilitates smooth movement of the discs 30 and connectors 20, even under conditions where great force is exerted on the brace 5. Embodiments could be designed with more than two discs 30, or could incorporate a gearing mechanism.

A lever 45 includes two parallel arms 50, each of which is attached at one end to a handle 55, and at the other end to the axle 40. The lever 45 is thus rotatable about the axle 40. However, each of the two arms 50 is also attached to the adjacent disc 30 with a fastener 48 which is located at a distance from the axle 40. Rotation of the lever 45 about the axle 40 causes the discs 30 to rotate, which in turn causes axial movement of the inner bar 15 relative to the outer tube 10, as described above.

Attached to the outer tube 10 at a distance from the discs 30 is a third pin 65. Each of two elongate elastic rubber tensioners 60 is attached at one end to the third pin 65, and at the other end to the adjacent disc 30 with a fastener 68 which is located at a distance from the axle 40. The fasteners 68 are located on the discs 30 such that rotation of the lever 45 so as to retract or shorten the brace 5 (i.e. slide the inner bar 15 further into the outer tube 10) causes the tensioners 60 to be stretched. In this way, the lever 45 is biased towards the position in which the brace 5 is extended to its full length. The strength of the bias of the lever 45 will depend on the characteristics of the tensioners 60 and on the position of the fasteners 68 relative to the axle 40, since the position of the fasteners 68 determines the bias applied to the lever 45. The fasteners 48 and fasteners 68 may be variously positioned on the discs 30 to achieve desired performance characteristics of the brace 5, as will be described in more detail below.

The outer tube 10 is attached to a foot assembly 70 shown in Figure 4. The foot assembly 70 is shown in Figures 1 and 2 secured to a floor; however, it can be attached to any other suitable fixed object. A connecting bar 72 is rigidly attached to the outer tube 10 and rotatably attached to two curved vertical members 75 with a fourth pin 80. The vertical members 75 are rigidly and perpendicularly mounted to a circular horizontal member 85. A circular base 90 is attached to the floor with, for example, screws or bolts (not shown) through holes 95. The base 90 may be recessed into the floor so that it will be unobtrusive when the door brace 5 is not in use. When the base 90 is mounted to the floor, it is positioned such that the arcuate lip 105 which protrudes over the cylindrical cavity 100 is furthest from the door. The arrangement of the various elements of the foot assembly 70 is such that the horizontal member 85 is easily insertable into, and easily removable from, the cavity 100, in a substantially vertical direction. However, when the brace 5 is attached to the door and the floor, the angle between the outer tube 10 and the floor is such that the horizontal member 85 cannot be removed from the cavity 100. Thus, when the brace 5 is in operation, the foot assembly 70 is securely attached to the floor. When the brace 5 is not in use only the base 90 is attached to the floor.

Referring to Figures 5 and 6, attached to the inner bar 15 is a head assembly 110 adapted to attach to the door, which includes two arms 115 which are rigidly attached to the inner bar 15 with bolts 120. The arms 115 extend past the end of the inner bar 15. An axle 125 is attached to the free ends of the arms 115. The head assembly 110 also includes a circular plate 130, which is attachable to a door with conventional fasteners (not shown), through the holes 135. Rigidly mounted on the plate 130 is a substantially cylindrical hook 140, which includes a horizontal opening 145 adapted to receive the axle 125. The interior of the hook 140 includes a protrusion (not shown) which allows the axle 125 to "snap" into the hook 140. Once the axle 125 has been inserted or snapped into the hook 140, there is sufficient movement of the axle 125 within the hook 140 to allow the angle of the inner bar 15 relative to the door to change, such as will occur when the brace 5 is retracted and the door is opened.

To install the door brace 5, the base 90 is attached to the floor at a suitable distance from the door, and the circular plate 130 is attached to the door, as illustrated in Figures 1 and 2. The horizontal member 85 is inserted into the cavity 100, to secure the foot assembly 70 to the floor. The axle 125 is inserted through the opening 145 into the hook 140, to secure the head assembly 110 to the door.

The position of the head assembly 110 largely determines the position of the base 90. If the head assembly 110 is attached to the door near the free vertical edge of the door, optimal leverage is provided to maintain the door in a closed position or for closing the door. If the head assembly 110 is attached to the door near the centre of the door, optimal bracing is provided to protect the door itself from external blows. The foot assembly 70 should preferably be positioned such that the brace 5 when in place is in a plane approximately perpendicular to the plane of the door in the closed position.

If the operator wishes partially to open the door, the brace 5 is retracted to the shorter length position, as illustrated in Figure 1, by rotating the lever 45 towards the inner bar 15, which causes the discs 30 to rotate, and the connectors 20 to slide the inner bar 15 further into the outer tube 10. At the same time, the tensioners 60 are extended, thus increasing the force applied to the discs 30, and biassing the lever 45 towards the extended longer length position. Thus, some of the energy used by the occupant to move the lever 45 towards the retracted shorter length position is stored in the tensioners 60 for later use in forcefully closing the door. The tensioners 60 can be attached to the discs 30 so as either to lock lever 45 in the retracted position, or to urge the lever 45 towards the extended position even when the brace 5 is in the fully retracted position. Thus, by variously positioning the tensioners 60 on the discs 30, the brace 5 can be configured to exhibit desired performance characteristics.

The length of the brace 5 depends upon the position of the pin 35: by attaching the connectors 20 to the discs 30 at a point closer to the axle 40, the range of movement of both the inner bar 15 and the door is reduced, and the closing force exerted on the door is increased. Other performance characteristics of the brace 5 can also be controlled by variously positioning the pin 35, as will be apparent to those skilled in the art.

To close the door, the lever 45 is rotated to the extended position as shown in Figure 2. As the arms 50 of the lever 45 are substantially longer than the distance between the fastener 35 and the axle 40, the force exerted on the handle 55 by the operator of the brace is magnified many times through the connector 20 to the inner bar 15. Consequently, relatively little effort is required on the handle 55 to close the door forcefully. In addition, the tensioners 60 assist in rotating the discs 30 towards the extended position, thus adding even more force to close the door.

Note that when the discs 30 are in the extended position, the second pin 35 is aligned with the axle 40 along the common axis of the outer tube 10 and the inner bar 15. This arrangement is best illustrated in Figure 7 (note that the arrangement of the connectors 20 and discs 30 of the second embodiment, illustrated in Figure 7, is the same as that for the first embodiment). This arrangement ensures that the brace 5 will remain in the extended position if the door is subjected to blows, that is, the lever 45 will not move. Thus, an opening force exerted on the door will travel along the common axis 17, that is, through the head assembly 110, the inner bar 15, the connectors 20, the axle 40, the outer tube 10, the foot assembly 70, and finally to the floor. The lever 45 is also maintained in the extended position by the tensioners 60 or gas springs 155. A lever restraining assembly 300 spanning the discs 30, as shown in Figure 10, may be used to prevent over rotation of the lever 45. Note that even when the discs 30 are close to the extended position, and the second pin 35 is not quite aligned with the axle 40 along the common axis of the outer tube 10 and the inner bar 15, an opening force exerted on the door will exert little rotational force on the discs 30. By contrast, force exerted on the lever 45 will be effective in applying a closing force to the door throughout the arc of rotation of the lever 45.

Figures 6 and 7 illustrate a door brace that includes two gas springs 155, in place of the rubber tensioners 60, which operate in a similar fashion to a combined spring and damper. The gas springs 155 bias the brace 5 towards the extended longer length position, while at the same time rendering the movement of the lever 45 more controlled.

In Figures 6, 7 and 8, an energy absorption and storage unit 160 is mounted in the outer tube 10, and includes a sleeve 165 inserted in the outer tube 10. The sleeve 165 extends from and is rigidly attached to the outer tube 10. A second inner bar 170 is inserted in the sleeve 165, which extends from, and is axially slidable within, the sleeve 165. The free end of the second bar 170 is rotatably attached to the vertical members 75 of the foot assembly 70 with fourth pin 80.

As shown in Figure 8, the energy absorption and storage unit 160 includes a gas spring 175 which includes a cylinder section 180 attached to the sleeve 165 and outer tube 10 with a bolt 185 which passes through the sleeve 165 and outer tube 10. The gas spring 175 also includes a piston rod 190 which is attached to the second inner bar 170 at a threaded section 195.

If extreme force is being applied to a partially open door preventing closure, the lever 45 can still be rotated to the extended longer length position of the door brace 5: the inner bar 15 slides out from the outer tube 10 to its extended position, and the energy absorption and storage unit 160 compresses to allow for such movement, allowing the gas spring 175 to exert a continuous pressure on the door. Since the gas spring 175 can be very stiff, the continuous force exerted by the energy absorption and storage unit 160 on the door can be correspondingly large. As soon as the force decreases, the door is closed by the energy absorption and storage unit 160. A continuous closing force will still be exerted on the door even though the operator/occupant has moved away from the door. Another advantage is that the energy absorption and storage unit 160 will absorb the shock of sharp forceful blows administered to a partially open door, reducing the strain on the door and brace 5. The energy absorber will also cushion any force that may be transmitted to the door brace, thus facilitating operation of the brace under these severe conditions.

The door brace 5 as shown in Figures 6, 7 and 9 includes a lever restraining assembly 200 including a collar 205 which is slidable on the inner bar 15, but restricted to axial movement over a limited distance by the key 210, which passes through the collar 205 into the keyway 215. Attached perpendicularly to the collar 205 is a clip 220 lined with rubber 225.

During operation of the lever 45, the lever restraining assembly 200 can be positioned as in Figure 9 such that the handle 55 of the lever 45 is clamped within the clip 220. In this configuration, the brace 5 is temporarily secured in the retracted shorter length position, even though the lever 45 may be biased towards the extended position by virtue of the arrangement of the gas springs 155, connectors 20 and discs 30. Note that the handle 55 may be easily pulled from the clip 220 by the operator.

However, during operation of the lever 45 (assuming that the brace 5 is installed), the gravitational force will position the lever restraining assembly 200 as shown in Figures 6 and 7. In this configuration, the lever restraining assembly 200 is not operational and hence unless restrained by the operator, the lever 45 will move towards the extended position. One advantage of this arrangement of the lever restraining assembly is as follows. It is possible in some embodiments of the invention that a very forceful blow, applied to the door when the lever 45 is in a position between the extended and retracted positions, could cause the lever 45 to rotate suddenly to the retracted position. In this case, since the lever restraining assembly 200 would not be operational, the lever would automatically move back towards the extended position once the force on the door was reduced. Thus, even without the operator being present, the brace 5 would automatically close the door due to the bias of the lever 45 towards the extended position.

An alternative lever restraining assembly 300 is illustrated in Figure 12. Note that this embodiment is designed for use with a brace 5 in which the lever 45 is biased towards the extended position. As with the embodiment shown in Figures 6, 7 and 9, the lever restraining assembly 300 includes a collar 205 which is slidable on the inner bar 15, but restricted to axial movement over a limited distance by the key 210, which passes through the collar 205 into the keyway 215. Attached perpendicularly to the collar 205 in this embodiment is an L-shaped clip 305.

During operation of the lever 45, the lever restraining assembly 300 can be positioned as in Figure 12 such that the handle 55 of the lever 45 is clamped by the L-shaped clip 305. The force exerted by the handle 55 on the L-shaped clip 305 causes the collar 205 to rotate slightly relative to the inner bar 15: the static frictional force thus generated between the collar 205 and the inner bar 15 prevents the collar 205 from sliding axially relative to the inner bar 15. Thus, in this configuration, the brace 5 is temporarily secured in the retracted shorter length position, even though the lever 45 may be biased towards the extended position by virtue of the arrangement of the gas springs 155, connectors 20 and discs 30. Note that the L-shaped clip 305 is only effective in securing the handle 55 as described above when the lever 45 is biased towards the extended position. Since it is the force exerted by the handle 55 on the L-shaped clip 305 that keeps the collar 205 from sliding down the inner bar 15, the operator need only move the handle 55 towards the inner bar 15 to disengage the lever restraining assembly 300. Once disengaged, the lever restraining assembly 300 slides down the inner bar 15 to rest in the position illustrated in broken lines in Figure 12. Importantly, the L-shaped clip 305 is also disengaged from the handle 55 if a forceful blow is administered to a partially open door.

In operation, if the brace 5 is used to partially open a door inwards, as shown in Figure 1, the L-shaped clip 305 can be slid up the inner bar 15 so as to engage the handle 55, as shown in Figure 12. Since the lever 45 is biased towards the extended position, the handle 55 exerts pressure on the L-shaped clip 305, thus rotating the collar 205 and temporarily securing the lever restraining assembly 300 relative to the inner bar 15. If a forceful blow is administered to the outside of the door (e.g., by a person throwing their weight against the door), the brace retracts slightly, causing the handle 55 to move towards the inner bar 15, thereby releasing the clip 305 and causing the collar 205 to slide down the inner bar 15 to the lower end of the keyway 215. Once the blow has been administered to the door, the force exerted on the door decreases. The biased lever 45, which is no longer restrained by the L-shaped clip, then moves to the extended position, forcefully closing the door. This embodiment of the invention has the effect of forcefully slamming the door on an intruder who tries to force the door open. Persons skilled in the art could develop other means of automatically forcefully extending the brace 5 following an impact on the door.

Figure 10 shows a third door brace 5 in which the two gas springs 155 are replaced with a single gas spring 230 located within the outer tube 10. The gas spring 230 includes a cylinder section 235 which is attached to the outer tube 10 with a bolt 240. The gas spring 230 also includes a piston rod 245 which is attached to the inner bar 15 at a threaded section 250. Movement of the lever 45 to the retracted position causes the inner bar 15 to slide further into the outer tube 10, thus compressing the gas spring 230. This compression of the gas spring 230 biases the door brace 5 towards the closed door position. This construction requires only one gas spring 230, which is concealed within the brace 5. Another type of spring, such as a coil spring, could be used.

Figure 11 shows a fourth door brace 5 which includes an inner bar 15 slidable within an outer tube 10, but does not include means for urging the inner bar 15 toward the extended position. Instead, the length of the inner bar 15 is adjusted by inserting a pin 270 into any one of the adjustment holes 265.

In operation, the pin 270 is inserted into the appropriate adjustment hole 265 to maintain the door in the closed position. The door cannot be opened because the outer tube 10 contacts the pin 270. If it is desired partially to open the door, the pin 270 is removed, allowing the door to be opened and the inner bar 15 to be slid into the outer tube 10 until the outer tube 10 contacts the stop 290, which is fixed to the inner bar 15. If it is desired to open the door a lesser amount, another pin could be inserted into an adjustment hole 265 prior to removing pin 370 for opening the door. Although the brace 5 cannot force the door to the closed position, further opening of the door is prevented unless the brace 5 is disengaged from the door and/or the floor.

Advantageously, the pin 270 may be shaped so as to force the brace 5 tightly against the door when securing the door in the closed position, as illustrated in Figure 13. The pin 270 of Figure 13 includes a thin section 271, a thick section 272, and a tapered section 273 located between the thin section 271 and the thick section 272. In operation, insertion of the thick section 272 into one of the holes 265 is made possible by the tapered section 273, and has the effect of slightly yet forcefully extending the brace 5 against the door by extending the inner bar 15 further out from the outer tube 10 when securing the door firmly in the closed position as any slack in the brace 5 is eliminated.

Numerous modifications, variations and adaptations may be made to the particular embodiments of the invention described above without departing from the scope of the invention, which is defined in the claims. The following are some examples of the many such modifications, variations and adaptations. Firstly, the brace could be constructed so as to operate in conjunction with a door that opens outwards. Secondly, the lever mechanism can be replaced by a piston/cylinder arrangement or a screw driven by a crank or motor. Thirdly, the discs could be replaced by components of various shapes, or the connectors could he attached directly to the lever. Fourthly, the manually operable pin of the fourth embodiment could be replaced by a ratchet mechanism.

Claims

A door brace (5) for bracing a door against a fixed object and for controlling movement of the door between a first at least partially open position and a second closed position, the door brace comprising: an elongate member (10,15) of variable length, axially moveable between a first length, corresponding in use to the door being partially open, and a second length, corresponding in use to the door being closed; a first anchor means (110) constructed and arranged to secure in both axial directions a first end of the elongate member (10,15) to a door; a second anchor means (70) constructed and arranged to secure in both axial directions, a second end of the elongate member (10,15) to a fixed object; and
energy storage means (60) for exerting an axial force on the elongate member (10,15) biasing the elongate member (10,15) toward the second length; characterised by:
a manually operable control mechanism (45,30,20) adapted so as:

to receive a manually applied first input force and simultaneously to generate a first output force urging the elongate member (10,15) toward the first length, and a second output force greater than the first input force, the second output force acting on the energy storage means (60) so as to increase the axial force on the elongate member (10,15); and

to receive a manually applied second input force and simultaneously to generate a third output force greater than the second input force, the third output force urging the elongate (10,15) member toward the second length.
A door brace as defined in claim 1, further characterised in that said control mechanism (45,30,20) comprises a lever mechanism.
A door brace as defined in claim 2, further characterised in that the lever mechanism (45,30,20) is lockable such that the elongate member (10,15) may be locked in the first length and at the second length against movement in both axial directions.
A door brace as defined in claim 2, wherein the elongate member comprises an outer tube (10) and a coaxial first elongate inner member (15) slidable within and extending from the outer tube (10), whereby the control mechanism (45,30,20) moves the elongate member between the first and second lengths by controlling the axial movement of the first elongate inner member relative (15) to the outer tube (10).
A door brace as defined in claim 4, wherein the control mechanism comprises a lever (45) rotatably attached to the elongate member, and a connector (65) for converting rotational movement of the lever (45) into axial movement of the first elongate inner member (15) relative to the outer tube (10).
A door brace as defined in claim 5, further characterised in that the lever mechanism comprises at least one disc (30) rotatable relative to the outer tube (10), a lever (45) for rotating the at least one disc (30), and a connector (65) for converting rotational movement of each of the at least one disc (30) into axial movement of the first elongate inner member (15).
A door brace as defined in claim 6, further characterised in that the lever mechanism comprises an axle (40) perpendicular to and passing through the elongate member (10,15), a pair of opposed discs (30) attached to the axle (40), a lever (45) attached to both discs (30) for rotating the discs, and a pair of connectors (65) for converting rotational movement of the discs (30) into axial movement of the first elongate inner member (15).
A door brace as defined in claim 6, further characterised in that the energy storage means comprises an elastic tensioner (60) having a first end attached to the at least one disc (30) and a second end attached to the elongate member (10,15), whereby movement of the elongate member (10,15) from the second length to the first length causes the tensioner (60) to stretch.
A door brace as defined in claim 6, further characterised in that the energy storage means comprises a gas spring (155) having a first end attached to the at least one disc (30) and a second end attached to the elongate member (10,15), whereby movement of the elongate member (10,15) from the second length to the first length causes the gas spring (155) to compress.
A door brace as defined in claim 4, further characterised in that the energy storage means comprises a gas spring (230) located within the outer tube (10) and having a first end attached to the outer tube (10) and a second end attached to the first elongate inner member (15), whereby axial movement of the first elongate inner member (15) relative to the outer tube (10) causes the gas spring (230) to compress.
A door brace as defined in claim 4, further characterised in that the first elongate inner member (15) comprises a bar.
A door brace as defined in claim 4, wherein the elongate member (10,15) includes energy absorption and storage means (160) adapted to absorb energy upon an axial force being applied to the elongate member (10,15).
A door brace as defined in claim 12, further characterised in that the energy absorption and storage means (160) comprises a coaxial second elongate inner member (165) slidable within and extending from the outer tube (10), and a spring (175) within the outer tube (10) having a first end attached to the second elongate inner member (165) and a second end attached to the outer tube (10), whereby the application of an axial force to the elongate member (10,15) causes the second elongate inner member (165) to move axially relative to the outer tube (10), causing the spring (175) to compress, and thereby absorbing and storing energy resulting from the application of the axial force.
A door brace as defined in claim 13, further characterised in that the spring comprises a gas spring (175).
A door brace as defined in claim 1, further characterised in that:

the first end of the elongate member (10,15) comprises a second pin (125) mounted perpendicularly to the elongate member, the second pin (125) having first and second supporting ends; and

the first anchor means (110) comprises a first plate (130) attachable to a door, a cylindrical hook (140) attached to the first plate (130) and adapted to releasably receive the second pin (125).
A door brace as defined in claim 1, further characterised in that:

the second end of the elongate member (10,15) comprises a rotatable circular foot (85); and

the second anchor means (70) comprises a second plate (90) attachable to a fixed object, the second plate (90) having a cylindrical cavity (100) for receiving the foot (85) and a lip (105) extending over the cavity (100) for restraining the foot (85);

the arrangement of the second end of the elongate member (10,15) and the second anchor means (70) being such that the foot (85) is not releasable from the cavity (100) during operation of the door brace and is releasable from the cavity (100) when the first end of the elongate member (10,15) is not attached to the door.
A door brace as defined in claim 1, further characterised in that the control means (45,30,20) biases the elongate member (10,15) toward the second length.
A door brace as defined in claim 17, further comprising restraining means (200) for releasably fixing the elongate member at the first length.
A door brace as defined in claim 18, further characterised in that the restraining means (200) automatically releases the elongate member (10,15) from the first length upon the administration of a force to the elongate member (10,15) tending to move the elongate member (10,15) toward a further retracted position, thereby allowing the elongate member (10,15) to extend forcefully toward the second length.
A door brace as defined in claim 17, further characterised in that restraining means (200) are provided for releasably fixing the elongate member (10,15) at the first length, the restraining means comprising:

a collar (205) axially slidable on the elongate member (10,15);

a clip (220) attached to the collar (205) for releasably receiving the lever (45).
A door brace as defined in claim 20, further characterised in that:

the lever (45) comprises a first pin (125) mounted perpendicularly to the elongate member (10,15); and

the clip (140) includes a cylindrical hook adapted to releasably receive the first pin (125).
A door brace as defined in claim 20, further characterised in that the restraining means (200) automatically releases the elongate member (10,15) from the first length upon the administration of a force to the elongate member (10,15) consistent with urging the elongate member (10,15) from the second length toward the first length, thereby allowing the elongate member (10,15) to extend forcefully toward the second length.
A door brace as defined in claim 22, further characterised in that the clip (305) is L-shaped.