Patent Description:
Fire-rated doors (i.e., fire doors) are doors constructed of materials that work together to slow or stop the spread of flames, smoke and, in certain applications, radiant and conductive heat transfer. Common materials utilised in fire-rated door construction include wood, steel, fiberglass, fire-rated glass, and combinations of these materials.

Fire-rated door assemblies are given a fire rating determined through standardised tests. Typically, fire-rated doors are subjected to a fire endurance test to determine their fire rating. This test is used to measure how long the door remains intact without failure under application of extreme heat, i.e., the fire resistance of the door.

One way of increasing fire resistance of a fire door is by increasing the fire resistance of the door leaf or door leaves (i.e. door panel or door panels) of said fire door. Commonly, each door leaf of a fire door comprises a frame and at least one infill panel retained within the frame. The quicker an infill panel breaks or fails to perform its function during a fire, the lower the fire resistance and thereby fire rating of the fire door. One potential way in which a door leaf may fail during a fire is if an infill panel of the door leaf falls out of the frame of the door leaf: the fallen infill panel is no longer able to perform its function of preventing the spread of fire through the door leaf. Therefore, it would be advantageous to provide a fire door assembly wherein the infill panel or infill panels are retained more securely within each door leaf.

One way of improving the retention of an infill panel within a door leaf is attaching the infill panel to the frame of the door leaf using a retaining device. During installation of the infill panel in the door leaf, a portion of the retaining device is generally bent against the infill panel, to thereby grip the infill panel, using a glazing tool. However, for known retaining devices, the glazing tool tends to slip (e.g. away from the infill panel) while being used to apply a force to bend the retaining device. There are two main issues that result from this slipping of the glazing tool. The first is that the portion of the retaining device being bent is not consistently bent through the desired angle, e.g. <NUM>°. The infill panel is therefore not gripped as tightly by the retaining device and is more prone to failure (i.e., falling out of the frame) during a fire. The second issue is that the installation of the infill panel is more challenging and/or slower because the person installing the retaining device needs to be careful to avoid the glazing tool slipping. Furthermore, when the glazing tool slips, the person installing the retaining device needs to reapply a force to bend the retaining device, further increasing the time and physical exertion required to complete installation and wearing out the person installing the retaining device more quickly. An additional downside to slipping of the glazing tool is that the desired angle of bend cannot be achieved easily, safely, and without risk of infill panel damage.

For example document <CIT> discloses a fire door with a retaining device comprising two legs that are bent upwardly against the infill panel. Further, document <CIT> discloses a fire door with a retaining device made of two parts.

The present disclosure solves these problems by providing an improved retaining device, which can be positioned inside existing fire doors and facilitates easier and more consistent infill panel installation.

One aspect of the present disclosure is directed to a fire door comprising at least one door leaf, wherein each door leaf comprises a frame and at least one infill panel retained within the frame. The frame comprises: a first frame member and a second frame member spaced from the first frame member; a glazing bead attached to the second frame member; and at least one retaining device for retaining one of the at least one infill panels between the first frame member and the glazing bead. The retaining device is made of a material having a melting point of at least <NUM>, preferably at least <NUM>, and comprises: an L-shaped portion located at a first end of the retaining device, the L-shaped portion comprising: a first base attached to the first frame member; and a wall extending upwardly from the first base, wherein the wall contacts a first side of the infill panel; a second base located at a second end of the retaining device, wherein the second base is attached to the second frame member; a middle portion located intermediate the first end and the second end and adjacent the second base, wherein the middle portion comprises: a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg extending from an edge of the raised surface adjacent the sidewall, wherein the at least one leg is bent upwardly against a second side of the infill panel, and wherein the infill panel is gripped between the wall and the at least one leg. The second base includes a protrusion extending from a top surface thereof and spaced from the middle portion, or the retaining device includes an additional piece attached to the top surface of the second base and spaced from the middle portion.

Preferably, the infill panel is made of fire-rated glass. Alternatively, the infill panel is made of one or more fire retardant materials clad in aluminum or aluminum alloy.

The protrusion <NUM> acts as both a support and point of rotation for a glazing tool <NUM> when bending the at least one leg 40A, 40B. The protrusion <NUM> also acts indicates the location where the glazing tool <NUM> must be inserted, i.e., between the protrusion <NUM> and the side wall <NUM>. In some arrangements, the protrusion <NUM> may add to the strength of the retaining device <NUM> by acting as a stiffening rib.

Preferably, the first and/or second frame member and/or glazing bead are made from aluminum or an aluminum alloy. More preferably, each of the first frame member, the second frame member and the glazing bead are made from aluminum or an aluminum alloy.

Advantageously, the material the retaining device is made of is compatible with aluminum. Preferably, the retaining device is made of stainless steel.

In preferred aspects, the L-shaped portion has an angle of <NUM>° or less between the first base and the wall. Preferably, the angle is in a range of <NUM>°-<NUM>°.

Preferably, the retaining device comprises at least two legs. More preferably, the retaining device comprises two legs.

The retaining device may be attached to each of the first and second frame members by one or more fastening elements. Preferably, the retaining device is attached to each of the first and second frame members by one or more screws.

The protrusion or additional piece may extend parallel to the corner between the sidewall and second base.

In preferred aspects, the door is a swing door.

The second base may preferably comprise a curved lip located at the second end of the retaining device, wherein the curved lip is configured for receipt within a feature of the second frame member.

The door may further comprise at least one fixed door leaf.

A further aspect of the present disclosure is directed to a retaining device for use in retaining an infill panel in a fire door, wherein the retaining device is made of a material having a melting point of at least <NUM>, preferably at least <NUM>, and wherein the retaining device comprises: an L-shaped portion located at a first end of the retaining device, the L-shaped portion comprising: a first base for attachment to a first frame member of a fire door; and a wall extending upwardly from the first base; a second base for attachment to a second frame member of a fire door located at a second end of the retaining device; a middle portion located intermediate the first end and the second end and adjacent the second base, wherein the middle portion comprises: a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg extending from an edge of the raised surface adjacent the sidewall towards the second end of the retaining device. The second base includes a protrusion spaced from the middle portion, or the retaining device includes an additional piece comprising a third means for attachment to a top surface of the second base wherein, when the additional piece is attached to the top surface of the second base, the additional piece is spaced from the middle portion.

The material the retaining device is made of may have a higher melting point than: a material which the first frame member is made of; and a material which second frame member is made of.

The retaining device may be configured for attachment to each of the first and second frame members by one or more fastening elements. Preferably, the retaining device comprises one or more screw holes or slots such that the retaining device is attachable to each of the first and second frame members by one or more screws.

The second base may preferably comprise a curved lip located at the second end of the retaining device, wherein the curved lip is configured for receipt within a feature of a second frame member.

Also provided herein is a method of installing an infill panel in a frame of a door leaf of a fire door using at least one retaining device, wherein the frame comprises: a first frame member and a second frame member spaced from the first frame member; and a glazing bead for attaching to the second frame member, and wherein the method comprises: attaching the first base of the retaining device to the first frame member and the second base of the retaining device to the second frame member; where the retaining device comprises the additional piece, attaching the additional piece to the second base; placing the infill panel between the first frame member and the second frame member; placing a forward edge of a glazing tool in a corner formed by the sidewall of the middle portion and the second base of the retaining device; while using the protrusion or additional piece as support, bending the at least one leg upwardly by pivoting the glazing tool until the at least one leg is pressed against the infill panel, and attaching the glazing bead to the second frame member.

Lastly provided herein is a kit comprising at least one retaining device and a glazing tool for use in bending the at least one leg of the retaining device, wherein the glazing tool comprises: a wedged portion located at a first end; and a handle located at a second end, wherein the handle comprises a gripping portion, and wherein the gripping portion comprises a longitudinal axis parallel to a forward edge of the wedged portion.

In order that the present disclosure may be more readily understood, preferable aspects thereof will now be described, by way of example only, with reference to the accompanying drawings, in which:.

According to the present disclosure there is provided a retaining device. As shown in <FIG>, a retaining device <NUM> according to the present disclosure comprises from a first end <NUM> to a second end <NUM>: an L-shaped portion <NUM>, a middle portion <NUM> and a second base <NUM>. The L-shaped portion <NUM> comprises a first base <NUM> and a wall <NUM> extending upwardly from the first base <NUM>. In some aspects, the L-shaped portion comprises an angle <NUM> of <NUM>° or less between the first base <NUM> and the wall <NUM>. Preferably, the angle <NUM> may be in a range of <NUM>°-<NUM>°, <NUM>°-<NUM>°, <NUM>°-<NUM>°, <NUM>°-<NUM>° or <NUM>°-<NUM>°.

As depicted, the middle portion <NUM> comprises a raised surface <NUM>, raised with respect to the second base <NUM>, a sidewall <NUM> joining the raised surface <NUM> to the second base <NUM> and at least one leg 40A, 40B extending from an edge of the raised surface <NUM> adjacent the sidewall <NUM> towards the second end <NUM> of the retaining device <NUM>. In preferred aspects, the raised surface <NUM> is also raised with respect to the first base <NUM>.

In some aspects, the at least one leg 40A, 40B extending from an edge of the raised surface <NUM> adjacent the sidewall <NUM> towards the second end <NUM> of the retaining device <NUM> may be parallel to the second base <NUM>. In some aspects, the retaining device <NUM> comprises at least two legs 40A, 40B. In preferred aspects, the retaining device <NUM> comprises two legs 40A, 40B. It can be appreciated that it is advantageous for the retaining device <NUM> to comprise more than one leg 40A, 40B in case of breakage or failure of an at least one leg 40A, 40B: the retaining device <NUM> may still function to retain an infill panel. It is particularly advantageous for the retaining device <NUM> to comprise <NUM> legs 40A, 40B, e.g., as depicted, due to ease of manufacture.

In some aspects, the second base <NUM> comprises a protrusion <NUM> extending from a top surface <NUM> thereof, wherein the protrusion <NUM> is spaced from the middle portion <NUM> of the retaining device <NUM>. In preferred aspects, the protrusion <NUM> extends along the top surface <NUM> parallel to the corner joining the sidewall <NUM> and second base <NUM>. In preferred aspects as depicted, the protrusion <NUM> extends along the top surface <NUM> parallel to the corner joining the sidewall <NUM> and second base <NUM> across an entire width of the second base <NUM>.

According to the present disclosure there is provided a fire door. A fire door of the present disclosure comprises at least one door leaf <NUM> (i.e., door panel). In some aspects, the fire door may be a swing door. In some aspects, the at least one door leaf <NUM> comprises at least one fixed door leaf (i.e., a door leaf not movable between an open and a closed position).

The at least one door leaf <NUM> comprises a frame and at least one infill panel <NUM> retained within the frame. The at least one door leaf <NUM> of the present disclosure may comprise <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more infill panels <NUM>. In some aspects, the at least one infill panel <NUM> may be made of a fire-rated material, such as fire-rated glass, wood or steel. In preferred aspects, the at least one infill panel <NUM> is made of fire-rate glass. In alternative preferred aspects, the at least one infill panel may be made of one or more fire retardant materials clad in aluminum or aluminum alloy.

The frame of the present disclosure comprises a first frame member <NUM>, a second frame member <NUM>, a glazing bead <NUM> and at least one retaining device <NUM>. In preferred aspects, the first frame member <NUM> and/or second frame member <NUM> and/or glazing bead <NUM> are made from aluminum or an aluminum alloy. In preferred aspects, each of the first frame member <NUM>, the second frame member <NUM> and the glazing bead <NUM> are made from aluminum or an aluminum alloy. For example, the first frame member <NUM>, the second frame member <NUM> and the glazing bead <NUM> may be made from extruded aluminum or aluminum alloy.

The second frame member <NUM> is spaced from the first frame member <NUM>. In preferred aspects, the first frame member <NUM> and the second frame member <NUM> are separated by a thermal break <NUM>. The thermal break <NUM> may connect the first and second frame members <NUM>, <NUM> as depicted in <FIG>.

The glazing bead <NUM> is attachable to the second frame member <NUM>. For example, as depicted in <FIG>, the glazing bead <NUM> may be clipped to the second frame member <NUM> in the assembled door leaf <NUM>.

The at least one retaining device <NUM> acts to retain one of the at least one infill panels <NUM> between the first frame member <NUM> and the glazing bead <NUM>. The at least one retaining device <NUM> is made of a material having a melting point of at least <NUM>, preferably at least <NUM>. It is advantageous to provide the retaining device with a melting point higher than the typical temperature reached by a building fire to prevent the retaining device <NUM> melting or softening during a fire. The retaining device <NUM> is able to retain the infill panel <NUM> within the frame when the door leaf <NUM> is subjected to the temperatures and forces of a building fire, thereby preventing spread of the fire from one side of the door leaf <NUM> to the other. In some aspects, the material the retaining device <NUM> is made of has a higher melting point than: a material which the first frame member <NUM> is made of; and a material which second frame member <NUM> is made of. It can be appreciated that it is advantageous for the retaining device <NUM> to have a higher melting point than the first and/or second frame members <NUM>, <NUM>: this allows the retaining device <NUM> to retain its structural integrity and ability to retain the infill panel <NUM> within the frame even if exterior portions of the frame begin to melt or soften during a fire. In aspects wherein the first and/or second frame member <NUM>, <NUM> and/or glazing bead <NUM> are made from aluminum or an aluminum alloy, the material the retaining device <NUM> is made of preferably is compatible with aluminum. It can be appreciated that it is advantageous for the material of the retaining device <NUM> to be compatible with aluminum for preventing corrosion of the frame and/or retaining device <NUM>. In preferred aspects, the retaining device <NUM> may be made of stainless steel. Stainless steel is preferred because of its high melting point, ranging from <NUM> to <NUM>. Stainless steel also possesses good compatibility with aluminum.

As depicted in <FIG>, the wall <NUM> of the at least one retaining device <NUM> contacts a first side <NUM> of the at least one infill panel <NUM>. This helps hold the at least one infill panel <NUM> in place by limiting the infill panel's <NUM> movement. As also depicted, the first base <NUM> of the at least one retaining device <NUM> is attached to the first frame member <NUM>. In preferred aspects, the first base <NUM> comprises a first means of attachment 170A for attachment to the first frame member <NUM>. In some aspects, the first means of attachment 170A may include one or more fastening elements 540A. In a preferred aspect, the first base <NUM> of the at least one retaining device <NUM> may be attached to the first frame member <NUM> by one or more screws 540A. The first base <NUM> may comprise one or more screw holes or slots for receiving the one or more screws 540A therethrough.

The second base <NUM> of the at least one retaining device <NUM> is attached to the second frame member <NUM>. In preferred aspects, the second base <NUM> comprises a second means of attachment 170B for attachment to the second frame member <NUM>. In some aspects, the second means of attachment 170B may include one or more fastening elements 540B. In a preferred aspect, the second base <NUM> of the at least one retaining device <NUM> may be attached to the second frame member <NUM> by one or more screws 540B. The second base <NUM> may comprise one or more screw holes or slots for receiving the one or more screws 540B therethrough. In some aspects, the first means of attachment 170A and the second means of attachment 170B may be the same.

It can be appreciated that, when the middle portion <NUM> comprises a raised surface <NUM> raised with respect to both the second base <NUM> and the first base <NUM>, this is advantageous. The raised surface <NUM> provides additional room for components, such as additional insulating material, to be placed between the first and second frame members <NUM>, <NUM>. The height of the sidewall <NUM> (i.e., the offset of the raised surface <NUM> with respect to the second base <NUM>) may be dependent on the size of the at least one retaining device <NUM>. The dimensions of the at least one retaining device <NUM> may scaled according to the infill panel <NUM> and/or frame size.

In some aspects, the second base <NUM> of the at least one retaining device <NUM> may comprise a curved lip <NUM> located at the second end <NUM> of the at least one retaining device <NUM>. The curved lip <NUM> may be configured for receipt within a feature <NUM> of the second frame member <NUM>. A curved lip <NUM> is advantageous for facilitating correct attachment of the at least one retaining device <NUM> to the first and second frame members <NUM>, <NUM>: receipt of the curved lip <NUM> in the feature <NUM> assists with correctly locating the retaining device <NUM> during installation. One example of a feature <NUM> for receiving the curved lip <NUM> is a protrusion having a T-shaped cross-section as depicted. Alternatively, the second base <NUM> may comprise a locating feature other than a curved lip <NUM> for locating the retaining device <NUM> in the second frame member <NUM> during installation.

<FIG> and <FIG> depict an alternative retaining device <NUM> according to the present disclosure. The retaining device <NUM> includes an additional piece <NUM>, in place of a protrusion <NUM>. In all other aspects, the retaining device <NUM> is identical to the retaining device <NUM> of <FIG> and may comprise any and all of the features of the retaining device <NUM> described above.

The additional piece <NUM> may comprise a third means of attachment 170C for attaching the additional piece <NUM> to a top surface <NUM> of the second base <NUM>. In some aspects, the third means of attachment 170C may include one or more fastening elements. In a preferred embodiment, the additional piece <NUM> may be attached to the top surface <NUM> of the second base <NUM> of the at least one retaining device <NUM> by one or more screws 540C. Preferably, additional piece <NUM> is attached to the top surface <NUM> via one or more screws which also attach the second base <NUM> to the second frame member <NUM>. This is advantageous for simplifying installation of the retaining device <NUM> on the frame members <NUM>, <NUM>.

The additional piece <NUM> is spaced from the middle portion <NUM> of the retaining device <NUM> when attached. In some aspects, the additional piece <NUM> comprises a front edge <NUM> extending parallel to a corner joining the sidewall <NUM> and second base <NUM>. In preferred aspects as depicted, the front edge <NUM> of the additional piece <NUM> may extend parallel to the corner joining the sidewall <NUM> and second base <NUM> across an entire width of the second base <NUM>.

As shown in <FIG>, the at least one leg 40A, 40B of a retaining device <NUM>, <NUM> according to the present disclosure is bent upwardly during assembly of a fire door according to the present disclosure. Bending of the at least one leg 40A, 40B allows the at least one leg to be pressed against the second side <NUM> of the infill panel <NUM>. Although not depicted in <FIG> and <FIG>, the infill panel <NUM> is gripped between the wall <NUM> and the at least one leg 40A, 40B, after the leg has been bent upwardly against the second side <NUM> of the infill panel <NUM>. The contact between the wall <NUM> and the at least one leg 40A, 40B retains the infill panel <NUM> within the frame of the door leaf <NUM>.

It is to be appreciated that a typical infill panel <NUM> has multiple edges, for example four edges (top, bottom, two side edges). A door leaf <NUM> according to the present disclosure may comprise one or more retaining devices <NUM>, <NUM> for retaining an infill panel <NUM> within the frame located on two or more edges of the infill panel <NUM>. In some aspects, each edge of the infill panel <NUM> may be held by one or more retaining devices <NUM>,<NUM>. The optimum number and arrangement (e.g., location of and or spacing between) of retaining devices for retaining an infill panel <NUM> within the frame of a door leaf <NUM> will depend on the size and weight of the infill panel <NUM> and the size of the retaining device <NUM>, <NUM>.

As shown in <FIG>, a glazing tool <NUM> according to the present disclosure comprises from a first end <NUM> to a second end <NUM>, a wedged portion <NUM> and a handle <NUM>. The handle <NUM> comprises a gripping portion <NUM> having a longitudinal axis parallel to a forward edge <NUM> of the wedged portion <NUM>. The glazing tool <NUM> may be used to bend the at least one leg 40A, 40B of the at least one retaining device <NUM>, <NUM> of the present disclosure. In some aspects, the glazing tool <NUM> is made of a plastic material.

According to the present disclosure there is provided a kit comprising a glazing tool <NUM> and at least one retaining device <NUM>, <NUM> as described herein.

The present disclosure further provides a method of installing an infill panel <NUM> in a frame of a door leaf <NUM> of a fire door using at least one retaining device <NUM>, <NUM> of the present disclosure.

The method of installing an infill panel <NUM> in a frame of a door leaf <NUM> of a fire door using at least one retaining device <NUM> comprises attaching the first base <NUM> of the retaining device <NUM> to the first frame member <NUM> and the second base <NUM> of the retaining device <NUM> to the second frame member <NUM>. The infill panel <NUM> is then placed in between the first frame member <NUM> and the second frame member <NUM> and in contact with the wall <NUM>. Subsequently, the forward edge of a glazing tool, such as the glazing tool <NUM> of the present disclosure, is placed in the corner joining the sidewall <NUM> of the middle portion <NUM> to the second base <NUM> of the retaining device <NUM>. The at least one leg 40A, 40B is then bent by pivoting the glazing tool, while using the protrusion <NUM> as support, until the at least one leg 40A, 40B is pressed against the infill panel <NUM>. A glazing bead <NUM> is then attached to the second frame member <NUM>.

It can be appreciated that, when the forward edge of a glazing tool <NUM> is placed in the corner joining the sidewall <NUM> to the second base <NUM>, the glazing tool <NUM> is located between the second base <NUM> and the at least one leg 40A, 40B. As the glazing tool <NUM> is pivoted in the in direction of the infill panel <NUM>, the glazing tool <NUM> contacts the at least one leg 40A, 40B. The force exerted on the at least one leg 40A, 40B by the glazing tool <NUM> cause the at least one leg 40A, 40B to bend in a direction towards the infill panel <NUM>. This highlights the importance of the raised surface <NUM>, which raises the at least one leg 40A, 40B with respect to the second base <NUM>. Without the raised surface <NUM>, the glazing tool <NUM> would not be able to be inserted under the at least one leg 40A, 40B.

It is possible to place the forward edge of a glazing tool <NUM> in the corner joining the sidewall <NUM> and the second base <NUM> of the retaining device <NUM>, because the protrusion <NUM> extending from the top surface <NUM> of the second base <NUM> is spaced from the sidewall <NUM>. The protrusion <NUM> acts to prevent the glazing tool <NUM> from slipping backwards in a direction away from the sidewall <NUM> when being pivoted to bend the at least one leg 40A, 40B. Reducing slippage of the glazing tool <NUM> allows the desired angle of bend of the at least one leg 40A, 40B to be achieved more consistently, while also reducing the physical effort exerted by the installer, i.e., person installing the retaining device <NUM> and infill panel <NUM>. The desired angle of bend is <NUM>°, wherein the angle of bend is measured between the second base <NUM> and the at least one leg 40A, 40B. An angle of bend of <NUM>° achieves the greatest contact area between the at least one leg 40A, 40B and the second side <NUM> of the infill panel <NUM>. In other words, this desired angle allows the infill panel <NUM> to be held most securely within the frame, thereby reducing the likelihood of the infill panel <NUM> falling out of the frame, in particular in the event of a fire either side of the door.

The retaining device <NUM> of the present disclosure achieves, on average, an angle of bend of the at least one leg of between <NUM>-<NUM>°. In comparison, a retaining device not comprising a protrusion <NUM> but otherwise identical to the retaining device <NUM> of the present disclosure achieves, on average, an angle of bend of the at least one leg of between <NUM>-<NUM>°. Accordingly, the protrusion <NUM> helps to achieve a more consistent angle of bend.

It can be appreciated that the protrusion <NUM> also facilitates installation of the infill panel <NUM>. For example, the protrusion <NUM> may increase the speed of installation of the infill panel <NUM> in the frame by up to <NUM> % when compared to installing an infill panel using a retaining device not comprising the protrusion <NUM> but otherwise identical.

The protrusion <NUM> acts as both a support and point of rotation for a glazing tool <NUM> when bending the at least one leg 40A, 40B. The protrusion <NUM> also acts to indicate the location where the glazing tool <NUM> must be inserted in the retaining device <NUM>, i.e., between the protrusion <NUM> and the side wall <NUM>. In some arrangements, the protrusion <NUM> may add to the strength of the retaining device <NUM> by acting as a stiffening rib.

The present disclosure further provides a method of installing an infill panel <NUM> in a frame of a door leaf <NUM> of a fire door using at least one retaining device <NUM> of the present disclosure. The method of installing an infill panel <NUM> in a frame of a door leaf <NUM> of a fire door using at least one retaining device <NUM> comprises attaching the first base <NUM> of the retaining device <NUM> to the first frame member <NUM> and the second base <NUM> of the retaining device <NUM> to the second frame member <NUM>. The additional piece <NUM> is attached to the second base <NUM>. The infill panel <NUM> is then placed in between the first frame member <NUM> and the second frame member <NUM>. Subsequently, the forward edge of a glazing tool <NUM>, such as the glazing tool <NUM> of the present disclosure, is placed in the corner joining the sidewall <NUM> of the middle portion <NUM> to the second base <NUM> of the retaining device <NUM>. The at least one leg 40A, 40B is then bent by pivoting the glazing tool <NUM>, while using the additional piece <NUM> as support, until the at least one leg 40A, 40B is pressed against the infill panel <NUM>. A glazing bead <NUM> is then attached to the second frame member <NUM>.

In preferred aspects, the additional piece <NUM> is attached to the second base <NUM> at the same time as the second base <NUM> is attached to the second frame member <NUM>.

It can be appreciated that, when the forward edge of a glazing tool <NUM> is placed in the corner joining the sidewall <NUM> to the second base <NUM>, the glazing tool <NUM> is located between the second base <NUM> and the at least one leg 40A, 40B. As the glazing tool <NUM> is pivoted in the in direction of the infill panel <NUM>, the glazing tool <NUM> contacts the at least one leg 40A, 40B. The force exerted on the at least one leg 40A, 40B by the glazing tool <NUM> cause the at least one leg 40A, 40B to bend in a direction towards the infill panel <NUM>.

It is possible to place the forward edge of a glazing tool <NUM> in the corner joining the sidewall <NUM> and the second base <NUM> of the retaining device <NUM>, because the additional piece <NUM> attached to the top surface <NUM> of the second base <NUM> is spaced from the middle portion <NUM>. A front edge <NUM> of the additional piece <NUM> acts to prevent the glazing tool <NUM> from slipping backwards in a direction away from the sidewall <NUM> when being pivoted to bend the at least one leg 40A, 40B. Reducing slippage of the glazing tool <NUM> allows the desired angle of bend of the at least one leg 40A, 40B to be achieved more consistently, while also reducing the physical effort exerted by the installer. As disclosed above, the desired angle of bend is <NUM>°, wherein the angle of bend is measured between the second base <NUM> and the at least one leg 40A, 40B. An angle of bend of <NUM>° achieves the greatest contact area between the at least one leg 40A, 40B and the second side <NUM> of the infill panel <NUM>. In other words, this desired angle allows the infill panel <NUM> to be held most securely within the frame, thereby reducing the likelihood of the infill panel <NUM> falling out of the frame, in particular in the event of a fire either side of the door.

The retaining device <NUM> of the present disclosure, like the retaining device <NUM>, achieves, on average, an angle of bend of the at least one leg of between <NUM>-<NUM>°. In comparison, a retaining device not comprising an additional piece <NUM> but otherwise identical to the retaining device <NUM> of the present disclosure achieves, on average, an angle of bend of the at least one leg of between <NUM>-<NUM>°. Accordingly, the additional piece <NUM> helps to achieve a more consistent angle of bend, while also reducing the physical effort exerted by the installer.

It can be appreciated that the additional piece <NUM> also facilitates installation of the infill panel <NUM>. For example, the additional piece <NUM> may increase the speed of installation of the infill panel <NUM> in the frame by up to <NUM> % when compared to installing an infill panel using a retaining device not comprising the additional piece <NUM> but otherwise identical.

The front edge <NUM> of the additional piece acts as both a support and point of rotation for a glazing tool <NUM> when bending the at least one leg 40A, 40B. The front edge <NUM> also acts to indicate the location where the glazing tool <NUM> must be inserted in the retaining device <NUM>, i.e., between the front edge <NUM> and the side wall <NUM>.

It can be appreciated that the glazing tool <NUM> of the present disclosure is advantageous when used in the methods as described herein. In comparison to known glazing tools, the glazing tool <NUM> comprises a gripping portion <NUM> having a longitudinal axis parallel to a forward edge <NUM> of the wedged portion <NUM>. This gripping portion <NUM> facilitates pivoting of the glazing tool <NUM> toward the infill panel <NUM>, i.e., makes this movement easier and more comfortable for the user. As a result, the glazing tool <NUM> reduces the time taken to install the retaining device <NUM>, <NUM> when compared to a known glazing tool.

Claim 1:
A fire door comprising at least one door leaf (<NUM>), wherein each door leaf comprises a frame and at least one infill panel (<NUM>) retained within the frame, wherein the frame comprises:
a first frame member (<NUM>) and a second frame member (<NUM>) spaced from the first frame member (<NUM>);
a glazing bead (<NUM>) attached to the second frame member (<NUM>); and
at least one retaining device (<NUM>,<NUM>) for retaining one of the at least one infill panels (<NUM>) between the first frame member (<NUM>) and the glazing bead (<NUM>), wherein the retaining device (<NUM>,<NUM>) is made of a material having a melting point of at least <NUM>, and wherein the retaining device (<NUM>,<NUM>) comprises:
an L-shaped portion (<NUM>) located at a first end (<NUM>) of the retaining device (<NUM>,<NUM>), the L-shaped portion (<NUM>) comprising:
a first base (<NUM>) attached to the first frame member (<NUM>); and
a wall (<NUM>) extending upwardly from the first base (<NUM>), wherein the wall (<NUM>) contacts a first side (<NUM>) of the infill panel (<NUM>);
a second base (<NUM>) located at a second end (<NUM>) of the retaining device (<NUM>,<NUM>), wherein the second base (<NUM>) is attached to the second frame member (<NUM>);
a middle portion (<NUM>) located intermediate the first end (<NUM>) and the second end (<NUM>) and adjacent the second base (<NUM>), wherein the middle portion (<NUM>) comprises:
a raised surface (<NUM>) raised with respect to the second base (<NUM>); and
a sidewall (<NUM>) joining the raised surface (<NUM>) to the second base (<NUM>); and
at least one leg (40A, 40B) extending from an edge of the raised surface (<NUM>) adjacent the sidewall (<NUM>), wherein the at least one leg (40A,40B) is bent upwardly against a second side (<NUM>) of the infill panel (<NUM>), and wherein the infill panel (<NUM>) is gripped between the wall (<NUM>) and the at least one leg (40A,40B), and
wherein:
the second base (<NUM>) includes a protrusion (<NUM>) extending from a top surface (<NUM>) thereof and spaced from the middle portion (<NUM>); or
the retaining device (<NUM>,<NUM>) includes an additional piece (<NUM>) attached to the top surface (<NUM>) of the second base (<NUM>) and spaced from the middle portion (<NUM>).