NZ547111A - A sill for a bi-fold door assembly - Google Patents

Abstract

A sill for a bi-fold door assembly comprises at least two parts, a first part defining a part of an outside side of an elongated sill track cavity 19 and a second part defining part of an inside side of the cavity 19. A sill trolley 11can be inserted or removed from the sill track cavity 19 by disassembly of the first part relative to the second part, and is held captive in the cavity 19 when the parts are assembled.

Description

547 1 1 1 INTELLECTUAL PROPERTY CPFICF OF N.Z. 1 1 f.'.AY 2006 f^CEIVED PATENTS FORM NO. 5 Our ref: JT226080NZPR NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Divisional Application out of NZ 537940 A SILL FOR A BI-FOLD DOOR ASSEMBLY We, Crane Enfield Metals Pty Ltd an Australian Company, of 2115 Castlereagh Road, Penrith, New South Wales, 2750, Australia hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: 100787525J. DOC: JT:gbo (Followed by page 1 a) 1a (Followed by page 2) A SILL FOR A BI-FOLD DOOR ASSEMBLY FIELD OF THE INVENTION This invention relates to a sill for a bi-fold door assembly and relates particularly, but not exclusively to a sill for a bi-fold door assembly that may be used to close openings in buildings that are larger than a single door in width.

This application is a divisional of Application No. 537940.

BACKGROUND ART Hitherto, bi-fold door assemblies have been used to close openings in buildings. The openings may be internal wall openings, or external wall openings where the door is subject to exposure to weather. In recent times cafes, in particular, have utilised bi-fold door assemblies to close 20 or open the front of the cafe to the public. This allows a cafe to have tables in the open air outside of the building of the cafe and enables the patrons to feel that they are still part of the cafe . In homes, bi-fold doors have been used to close internal wall openings, or 25 external wall openings where a person can open the bi-fold door assembly to give the feeling of open space to the building. As the opening usually extends over a considerable length, it means that a plurality of bi-fold door panels need to be hinged together and suitably 30 carried. The bi-fold door assemblies are suspended from an upper track and carried by one or more wheels at the top of the door panels which engage and suspend the door panels from a head part of a door frame in which the track is located. Typically, the weight of the door panels is 35 excessive and there needs to be structural lintels or other structural arrangements provided to accommodate for the weight of the door panels. In some instances, the H:\deboram\keep\specifications\NZ Divisional 2 - A Bill for a bi-fold door assembly.doc 22/03/06 bottom of the door panels can be guided by a wheel which traverses along the floor but in all instances the bulk of the weight of the door panels is carried by the upper track.

As there needs to be a lintel provided of sufficient structural strength to accommodate the weight of the door panels it generally means that retro fitting of a bi-fold door assembly in a door opening is limited to purpose 10 built openings. If a lintel is not provided, then a bi-fold door arrangement cannot be accommodated.

Accordingly, for renovators wishing to modernise a cafe or home and provide a bi-fold door arrangement there has generally been an obstacle to the installation of a bi-15 fold door assembly. Further, even if a lintel is provided, the weight of the door panels is usually of such magnitude that there is sagging of the lintel over a period of time and the bi-fold door assembly needs to receive constant adjustments of the suspension mechanism 20 to maintain the bi-fold door assembly tracking correctly during opening and closing movement.

STATEMENT OF THE INVENTION According to one aspect of the invention there is provided a sill for a bi-fold door assembly, said sill being at least a two part sill with a first part defining a part of an outside side of an elongate sill track cavity that extends in a direction along the length of the sill, 3 0 the second part defining a part of the inside side of said sill track cavity, and wherein the first part and the second part can be assembled together to collectively define a sill and said sill track cavity in which a sill trolley can be received to traverse said sill track to 35 carry the bulk of the weight of at least one door panel of the assembly, and wherein the sill trolley can be inserted or removed from the sill track cavity by disassembly of H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 the first part relative to the second part, and wherein when the first part and second parts are assembled together the sill trolley will be held captive within the sill track cavity to traverse in said sill track cavity in 5 said direction, there being an elongate opening in an upper surface of the sill defined by first part and the second part, said elongate opening communicating with said cavity and permitting a weight bearing connection to be made between the at least one door and sill trolley within 10 said cavity.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention can be more clearly 15 ascertained an example of preferred embodiment will now be described with reference to the accompanying drawings wherein: Figure 1 is a front isometric view of a typical 20 example of a preferred embodiment of a bi-fold door assembly, Figure 2 is a close up perspective, part sectional view from an inside side of the assembly shown in Figure 1 25 showing a sill trolley fitted in the sill,.

Figure 3 is a top perspective view of the sill trolley shown in the example, 3 0 Figure 4 is an exploded perspective view of the sill trolley and a hinge that connects with door panels, Figure 5 is a non-exploded view similar to that of Figure 4 and showing door panels in a partly open 35 condition, H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 Figure 6 is a perspective view of a hinge for fitting at the top of a pair of door panels, showing the hinge in a closed condition, Figure 7 is a view similar to that of Figure 6, but showing the hinges in a door open condition, Figure 8 is a view similar to that of Figures 6 and 7, but showing the hinge at the top of the door panels in 10 partly opened condition and fitted to door panels.

Figure 9 is a plan view, in section, at a lower-most part of pair of door panels, showing the door panels in a closed condition, Figure 10 is a view similar to that of Figure 9, but showing the door panels in an open condition.

Figure 11 is a vertical cross-sectional view showing 20 the relationship of the door panels to the sill and the head, Figure 12 is a transverse cross sectional view of the sill and, Figure 13 is a diagramatic vertical cross sectional view showing a different example of a sill.

DETAILED DESCRIPTION OF EXAMPLES Referring firstly to Figure 1, there is shown a bi-fold door assembly 1 made from extruded aluminium sections. Whilst extruded aluminium sections are preferred, other materials such as wood, steel and the 3 5 like may be used. The invention is not to be limited to extruded aluminium sections. The assembly comprises an outer frame that fits in an opening in the building. The H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 outer frame is formed by a head 3, a sill 5, and 2 upright door frame parts 7. The upright door frame parts 7 have been shown as this is preferred. In some installations, the upright door frame parts 7 may not be utilised but 5 instead, the inside upright walls of the opening may define the outer side edges of the opening and the assembly. Figure 1 shows the assembly viewed from an outside side of an installation. Here it can be seen that the sill 5 has a downwardly sloping forward part which is 10 provided for aesthetic reasons and also to inhibit against the likelihood of a person tripping across the sill as they pass through the assembly when it is opened. In the assembly shown there are three door panels 9. The door panels 9 are made from extruded aluminium sections and 15 interconnected by hinges. They may be made from other materials such as wood or steel as described previously without departing from the ambit of the invention. The panels themselves in each of the door panels 9 may be glass or other planar structural material. One of the 20 door panels 9 is hinged about an upright axis to one of the upright door frame parts 7. Alternatively, it may be hinged to swing about an upright axis by being hinged directly to an upright part of the opening in a wall in the building. The other panels are hinged about a further 25 upright axis at a side opposite.

In the arrangement shown, the door panels are hinged by suitable hinges (to be referred to later). Typically, three hinges are provided at each of the hinge axis. The 3 0 exact number of hinges and the type of hinges can be chosen according to the size and weight of each of the door panels 9 and/or hinging arrangement required by the individual requiring the bi-fold door assembly.

Figure 2 shows a close-up perspective part cross- sectional view of the sill 5. A trolley 11 is provided to carry a weight bearing surface 13 (in this example wheel H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 means) and the trolley, in turn, supports the bulk of the weight of at least one of the door panels. The trolley 11 can track along the sill along a track 15 provided on the sill. The track 15 extends in a direction along the 5 length of the sill. Accordingly, during opening and closing of the door panels 9, the trolley 11 will support the bulk of the weight of at least one of the door panels 9 by the weight bearing surface 13 engaging on the track 15 and so the track 15 supports the weight of the door 10 panels 9. The track is substantially wholly under the door panels, when the door panels assume a closed condition in the assembly. This assists in inhibiting debris from entering the sill and fouling the track, thereby preventing good movement of the trolley 11 along 15 the track 15.

The weight bearing surface 13 may be provided by a slide surface, such as of a suitable plastics material slide surface fitted to the trolley.

In the embodiment shown, where there are three door panels 9, only one trolley 11 is required. In other installations, where there are multiples of the door panels 9, two or more trolleys 11 may be required. The 25 trolley 11 has a connection means 17 that enables the panels 9 to be connected with the trolley 11 at suitable positions such as, in this example, at a hinge of the panels. In the arrangement shown, and in Figure 1, the connection is at the hinge positions between the outermost 30 free door panel 9 and the next adjacent door panel 9. i.e. the end opposite to the end at which the door panels 9 are hinged to the upright door frame part 7 or to the wall of the building.

The trolley 11 is received within a cavity 19 in the sill 5. The cavity 19 is not clearly shown in Figure 2 but will be explained further in relation to Figures 11 H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 and 12 in due course. Accordingly, the track 15 is at the bottom of the cavity 19. The connection means 17 passes through an opening 21 in an upper surface of the sill 5 and permits connection between the trolley 11 and the door 5 panels 9. The opening 21 extends along the longitudinal extent of the sill 5. Figure 2 clearly shows that there are two tracks 15 at the bottom of the cavity 19. As shown, there are a pair of wheels on an inside side of the trolley 11 and further pair of wheels on an outside side 10 of the trolley 11. This is more clearly shown in Figure 3. Each of the wheels of the trolley has a weight bearing surface 13 and one pair of wheels tracks on one of the tracks 15 whilst the other pair of wheels tracks on the other track 15. It can be seen that the weight bearing 15 surfaces 13 are grooved so that they are shaped to laterally locate with the tracks so there will be aligned tracking as the bi-fold door panels are opened and closed. Each of the tracks 15 is an upstanding rib or flange from the bottom of the cavity 19.

The trolley 11 also carries a side thrust bearing surface 23. This side thrust bearing surface 23 cooperates with a corresponding side thrust bearing surface 25 on the sill to inhibit angular inclination of the door 25 panels from an intended upright condition otherwise caused by the weight of the door panels cranking the door panels from an intended upright condition. This is not clearly shown in Figure 2, but will be explained in more detail hereinafter in relation to Figure 11. Preferably, the 30 side thrust bearing surface 25 on the sill is a rib or flange that extends downwardly from an upper surface of the sill. In a particularly preferred example of the embodiment, as shown in the figures herein, the side thrust bearing surface 23 of the trolley is on the 35 opposite side of wheels relative to the weight bearing surface 13, and is on one of the pair of wheels.

Typically, the side thrust bearing surface 25 of the sill H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 is provided within the cavity 19 on an under surface of an upper part of the sill that partly defines the cavity 19 but it may be on upright side walls or on a rib or flange that extends therefrom.

Accordingly, it can be seen from Figures 2 and 3 that the trolley 11 is elongate in a direction along the longitudinal extent of the sill 5. The body of the trolley 11 may be made from any suitable material such as 10 industrial grade plastics or die cast metals. The trolley has a side 27 which is intended for fitting to an outside side of the assembly. It also has an inside side 29 for fitting to an inside side of the assembly. In Figure 1 the outside side is the side shown facing the viewer 15 whilst the inside side is the opposite side. The weight bearing surfaces 13 are provided by a pair of wheels on each of the outside side 27 and the inside side 29. The wheels are identified by numeral 31. Each wheel 31 contains bearings 33 that permit the wheels to rotate 20 about axles 35 that are fixed relative to the trolley 11. Typically the wheels 31 are made from an industrial grade plastics and are grooved as shown to assist in tracking along the upstanding ribs or flanges that define the tracks 15. Typically, the side thrust bearing surface 23 25 does not directly touch the side thrust bearing surface 25 of the sill until there is cranking of the trolley caused by the weight of the door panels. The tolerance between the side thrust bearing surface 23 of the trolley and the corresponding side thrust bearing surface 25 of the sill 30 can be a small dimension such as 1mm. Accordingly, if the trolley should be cranked because of the weight of the door panels when the door panels 9 are opened, then when the side thrust bearing surfaces 23 of the trolley engage with the side thrust bearing surfaces 25 of the sill, the 35 weight bearing surface 13 on the opposite side of the wheels disengages and lifts off the track 15 in the sill. Of course, the weight bearing surface 15 of the other pair H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 of wheels 31 remains engaged on the track 15 for those pair of wheels. This will be explained further in due course.

The connection means 17 carried by the trolley 11 has a height adjustment means 38 in the form of two nuts that are screw threaded relative to the connection means 17. Accordingly, by appropriately adjusting the nuts, and re-tightening them, there can be adjustment of the spacing 10 between the bottom surface of the door panels and the upper surface of the sill.

Whilst the side thrust bearing surface 23 of the trolley is shown as being the wheels 31, it may be 15 provided by either slide surface of surfaces such as of a suitable plastics material, or a further wheel or wheels. If a separate side thrust bearing surface 23 is provided independent of the wheels 31, then a closer tolerance between the side thrust bearing surface 23 and the side 20 thrust bearing surface 25 may be provided.

Referring now to Figures 4 and 5, there is shown how the weight bearing surfaces 13 are connected via the connection means 17 to the door panels. In the preferred 25 example, the connection is directly at the hinges 37 that hinge the door panels together. Figure 4 clearly shows the wings 39 of the hinges 37. The wings are preferably made from a suitable material such as brass, aluminium or the like. The wings 39 have a fixing flange part 41 with 30 a number of openings therein through which screws can be passed to fix the door panels 9 thereto. Connected with the fixing flange part 41 is an offset flange part 43, and connected with the offset flange part 43 is a further offset part 45 that has cylindrical hinge pin collars 47 35 attached to a free side thereof. Each of the offset flange parts 43 is stepped inwardly from the top and bottom edges of the fixing flange part 41 as shown. The H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 spacing between the collars 47 is such that when the wings 39 are brought together, all the collars 47 will between one another and align centrally so that a hinge pin 49 can be passed therethrough to hinge the wings 39 together.

Spacing washers or bushes may be provided between the adjacent collars 47 if required. Figures 4 and 5 also show a yoke 51 that forms a connection between the connecting means 17 and the door panels. The yoke 51 is made from a suitable material such as brass and has a 10 first body 53 of elongate cylindrical construction.

Connected to the first body 53 are two arms 55, and at the free end of arms 55 collars 57. The collars 57 have the same shape and size as the collars 47. The spacing apart of the arms 55 and the collars 57 from each other is such 15 that the arms 55 straddle the top and bottom of the hinge collars 47. Accordingly, the hinge pin 49 can hold the hinges 37 via the yoke 51 to the connection means 17. The central bore of the first body 53 is of a size to closely fit over the circular cross-section connection means 17. 20 To minimise any relative rotation of the yoke 51 about the connection means 17, the connection means 17 has a laterally fitted pin 59 that passes into an opening 61, and the pin 59 is arranged to locate in a keyway slot 63 in the bore of the first body 53. Accordingly, the arms 25 55 of the yoke 51 are held in a direction perpendicular to the longitudinal extent of the sill as the pin 59 inhibits rotation of the yoke 51 relative to the connection means 17. Plugs 65 can be used to close any spaces at the top and bottom of the hinges. The yoke 51 can be held captive 30 to the connecting means 17 by means of a screw and washer arrangement as shown. Accordingly, it can be seen that the connection means 17 connects with a door panel 9 at a position proximate to a side edge of a door panel 9 on the opposite side to the further upright axis (i.e. generally 35 at the hinge axis).

H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 Figure 5 shows that the frames of the door panels 9 are suitably checked with cut-outs 69. This maintains the collars 47 and 57 closely fitting relative to the faces of the door panels 9. The spacing of the arms 55 is such 5 that the first body 53 of the yoke 51 is displaced to the opposite side of the door panels 9 and allows for closing of the door panels so that the yoke of the first body 53 is concealed within cavities 71 of the frames of the door panels 9 when the door panels 9 are in a closed condition 10 (the hinges are closed). The offset flange parts 43 also have a sufficient dimension to enable the first body 53 of the yoke 51 to be held between the wings of the hinges 37 when the door panels 9 are in a closed condition.

Figure 8 clearly shows how the first body 53 of the yoke 51 locates in the cavities 71 of the frames of the door panels 9.

The hinges at an intermediate height of the door 20 panels 9 comprise hinges 37 without yokes 51. The hinges at the top of the door panel are hinges of a similar construction to that shown and explained for the bottom of the door panel and also include the same yoke 51. This arrangement is shown in Figures 6, 7 and 8. For these 25 upper hinges, the first body part 53 carries an upstanding pin 73. The pin is not clearly visible in the figures and has not been numbered. The pin has a collar part 75 that is fitted adjacent the upper surface of the first body 53. Affixed above the collar 75 is a wheel 77 of slightly 3 0 larger diameter than the diameter of the collar 75. The spacing between the collar 75 and the wheel 77 is sufficient to accommodate the thickness of flange parts that define side edges of a longitudinally extending head track cavity 79 in the head 3. Accordingly, the wheel 77 3 5 locates within the track cavity 79 and an outer surface of the wheel engages with the inside side or the outside side of walls 81 of the cavity. Accordingly, this acts to H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 provide a guide for the upper part of the door panels.

This guide is therefore for also inhibiting against angular cranking of the door panels from an intended upright position during opening and closing movement.

Whether the wheel 77 engages with the walls 81 is not entirely critical to the operation of the guiding for holding the upper part of the door panels 9 in an intended upright position as the side thrust bearing surface 23 is intended to provide the primary means to inhibit against 10 cranking. Accordingly, the track cavity 79 and the pin 73, collar 75, wheel 77 and walls 81 define a head tracking means in the form of a finger that extends upwardly from the top of at least one of the door panels. The cavity 79 defines a head track in which the finger can 15 traverse in a direction that extends along the longitudinal extent of the head. The wheel 77 can rotate about an upright axis and the wheel 77 locates in the cavity and acts to guide the top of at least one of the door panels as the door panels are opened and closed.

Referring now to Figures 9 and 10 there are shown transverse cross-sectional views immediately above the trolley 11 and taken horizontally through the door panels 9. Figures 9 and 10 also clearly show how the collars 47, 25 57 fit closely and snugly against one face of the door panels 9. The figures also show how the arms 55 of the yoke pass between the adjacent outer side edges of the door panels 9 when the door panels 9 are closed. The figures also show how the first body 53 of the yoke 51 30 fits within the cavity 71 in the door panels 9 and between the wings of the hinges.

Referring now to Figure 11 there is shown a vertical cross-sectional view of the door assembly 1, in a door 35 closed condition. Figure 11 also clearly shows the outside side 27 of the assembly and the inside side 29 of the assembly. It also shows the weight bearing surfaces H:\deboram\keep\speciffications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 23 engaging with the two tracks 15 and carrying the bulk of the weight of at least one of the doors panels 9.

Figure 11 also shows that the upper part of the door panels 9 are guided relative to the head 3 by a head 5 tracking means by a finger connected to and extending in a direction upwardly from the top of at least one of the door panels 9 and wherein the finger locates in an elongate cavity in the head 3. The figure also shows that the cavity 3 defines a head track in which the finger can 10 traverse in a direction that extends along the longitudinal extent of the head. The finger is therefore comprised of the pin 73, collar 75 and wheel 77. In the arrangement shown, when the doors open, the door panels 9 swing to the outside side 27 of the assembly. Thus, the 15 weight of the doors is offset from the weight bearing surface 13, and tends to crank the doors from an intended upright condition in a generally anti clockwise direction (when viewing Figure 11). This tends to lift the right hand side weight bearing surface 13 off the track 15 and 20 causes the side thrust bearing surface 23 to engage with the side thrust bearing surface 25 of the sill. The side thrust bearing surface 23 of the trolley has not been identified in Figure 11 in order to aid clarity.

Figure 11 also shows that the pair of tracks 15 are at the bottom of the cavity 19 and elevated from the bottom. It also shows that each of the tracks 15 is partly shielded from debris that may pass through the elongate opening 21 (numerically identified only in Figure 3 0 2 in order to aid clarity), and therefore the tracks 15 remain substantially free of debris.

From time to time, the cavity 19 may need to be opened. This may be undertaken to replace a trolley and 35 its respective wheels 31 or alternatively to remove debris from the cavity 19.

H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 Figure 12 shows how the sill 5 is at least a two part sill with a first part 83 defining a part of an inside side of the elongate sill cavity 19 and a second part 85 that defines a part of the outside side of the cavity 19.

Figure 12 shows that the first part 83 and second part 85 are connectable together and collectively define the sill and the cavity 19 in which the trolley 11 can be received to carry the bulk of the weight of at least one of the door panels 9 of the assembly. Accordingly, by 10 disconnecting the second part 85 from the first part 83, the cavity 19 may be opened to enable insertion and/or withdrawal of a trolley with associated wheels 31. The grooves in the wheels 31 have sufficient height and clearance to enable the wheels 31 to appropriately locate 15 on the relevant tracks 15 and the side thrust bearing surface 25. Debris may also be removed from the cavity 19 when the first part 85 is disconnected from the first part 83. The example shows that the first part 83 is provided with snap lock engaging ribs 87, and that the second part 20 85 is provided with complementary snap lock engaging ribs 89. Accordingly, by appropriately manipulating the second part 85 relative to the first part 83, there can be connection and/or disconnection of the first and second parts, and opening and/or closing of the cavity 19.

While snap lock engaging and disengaging has been shown, other forms of connection such as screw fastening may be provided. Figure 12 shows a slightly different sill to that shown in Figure 11. In Figure 12, there is 30 no foot tread 91 of wood or the like that forms a structural or finishing part of the opening in the building as shown in Figure 11. Instead, the sill 5 has a snap lock engageable base part 93 that can be fitted to the first part 83. This arrangement may be provided for 35 installations where there is no tread 91.

H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 Returning now to Figure 1, it can be seen that some of the door panels 9 have been shown with handles 95. The handles 95 are connected internally of the door frames with cranking arms that extend rods 97 either inwardly or 5 outwardly relative to the upper and lower surfaces of the frames of the door panels 9. The rods 97 are arranged to locate between the opening 21 in the sill 5, and the corresponding opening in the cavity 71 in the head 3. In this way, when the door panels 9 lie in line and parallel 10 to one another, the door panels can be locked closed by appropriately rotating the handles 95.

Modifications may be made to the invention as would be apparent to persons skilled in the art of making doors 15 and in particular bi-fold doors. For example, instead of the connecting means 17 being circular in transverse cross-section it may be rectangular or of other suitable cross-section and arranged to fit into a corresponding rectangular opening in the first body 53 of the yoke 51. 2 0 In this way, the keyway slot 63 and corresponding pin 59 may be dispensed with because if the connecting means 17 is rectangular or if other suitable cross section and fits in a corresponding opening in the body 53, the yoke will be held generally perpendicular to the tracks 15 without 25 relative rotation. Other cross sectional profiles may be adopted to provide the same effect. Whilst the weight bearing surfaces 13 have been shown as wheels 31, they may be slide surfaces formed from a suitable synthetic plastics material. Similarly, the side thrust bearing 3 0 surfaces 23 may be replaced by corresponding slide surfaces.

Figure 11 shows that when the door panels 9 are closed, they close against door stops formed on the head 35 3, sill 5 and the upright jamb part 7. This provides an effective weather seal particularly if suitable seal means H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 99 are provided. The provision of door stops is not an essential feature.

Further, whilst the panels 9 have been shown hinged 5 to one another and to an upright door part 7 such as the wall or a jamb, the door panels may be hinged only to one another, but not to the upright door part 7. In other words, the door panels will be relatively free and constrained within the assembly by the tracks 15 in the 10 sills and track cavity 79 in the head 3. When the door panels are fully closed and parallel to one another and inline, the panels 9 will then close the opening.

Operation of the handles 95 can then cause the rods 97 to extend outwardly and to lock into the respective openings 15 will and that will hold the assembly locked closed.

Further, whilst the assembly has been shown with the door panels hinged to one another, the door panels may each be independent of each other without being hinged to 20 one another, and wherein the connection means 17 connects at a position midway between the left and right hand sides of each of the panels 9. In this arrangement, there would need to be relative rotation between the connecting means 17 and door panels 9 to allow for the angular rotation 25 during opening and closing. Nevertheless, the arrangement of the side thrust bearing surfaces 23 and 25 would still be provided to inhibit against cranking that may be caused during movement of the door panels. Accordingly, in this arrangement, when the door panels are fully closed, so 30 that they lie parallel to one another and in line, the door panels may be arranged to interlock with each other by appropriate tongue and grooves in the outer side edges. Accordingly, when the handles 95 are cranked, the rods 97 will then also hold the door panels 9 in a locked 3 5 condition.

H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 In a variation of the above the door panels 9 may be hinged to one another, and the connection means connect with one or more of the panels at a position midway between the left and right hand sides of the one or more 5 panels.

Whilst a trolley 11 has been shown, the trolley itself may not be a physical trolley but merely an extension of the connection means 17. In such instance 10 the relevant part of the connection means 17 will be a trolley.

In the example shown in Figure 13 a further alternative arrangement is depicted. Here, the sill is 15 similar to that shown in the previous figures except that there is an additional side thrust bearing surface 25. Accordingly, above one of the tracks 15 is a side thrust bearing surface 25 and above the other of the tracks 15 there is a side thrust bearing surface 25. Under normal 20 conditions when the trolley 11 carries the weight of the door panels without any clockwise or anti-clockwise cranking caused by the weight of the door panels, the weight of the door panels is carried by the tracks 15. In this case, the upper surface of the wheels 31 is not 25 touching the side thrust bearing surfaces 25. However, should there be clockwise or anti-clockwise cranking, the respective wheel 31 will lift off the respective track 15 and engage the side thrust bearing surface 25.

Accordingly, the arrangement shown in Figure 13 will 30 inhibit against clockwise or anti-clockwise cranking caused by the weight of the door panels. Whilst the side thrust bearing surfaces carried by the trolley 11 (the upper surface of the wheels 31) are normally displaced a small distance such as 1mm from the side thrust bearing 35 surfaces 25 they may be brought into respective engagement depending on the direction of cranking caused by the weight of the door panels.

H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 Further, instead of utilising the wheels 31 to provide for the side thrust bearing surfaces 23 on the trolley, additional wheels may be provided to provide the 5 side thrust bearing surfaces or alternatively there may be corresponding slide surfaces provided to replace the wheels.

These and other modifications may be made without 10 departing from the ambit of the invention the nature of which is to be determined from the foregoing description.

H:\deboram\keep\specifications\NZ Divisional 2 - a sill for a bi-fold door assembly.doc 22/03/06

Claims (8)

1. A sill for a bi-fold door assembly, said sill being at least a two part sill with a first part defining a part 5 of an outside side of an elongate sill track cavity that extends in a direction along the length of the sill, the second part defining a part of the inside side of said sill track cavity, and wherein the first part and the second part can be assembled together to collectively 10 define a sill and said sill track cavity in which a sill trolley can be received to traverse said sill track to carry the bulk of the weight of at least one door panel of the assembly, and wherein the sill trolley can be inserted or removed from the sill track cavity by disassembly of 15 the first part relative to the second part, and wherein when the first part and second parts are assembled together the sill trolley will be held captive within the sill track cavity to traverse in said sill track cavity in said direction, there being an elongate opening in an 20 upper surface of the sill defined by first part and the second part, said elongate opening communicating with said cavity and permitting a weight bearing connection to be made between the at least one door and sill trolley within said cavity. 25

2. A sill as claimed in claim 1, wherein the first part and the second part are provided with co-operating snap lock fitting surfaces that permit snap lock assembly or disassembly together of the first part and the second 30 part.

3. A sill as claimed in claim 1 or claim 2, wherein the sill track cavity has sill trolley engaging track surfaces therein which extend upwardly from a bottom of the track, 35 and, in use, space the sill trolley above the bottom of the sill track cavity. H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06 - 20 -

4. A sill as claimed in claim 3, wherein the sill trolley engaging surfaces are a pair of laterally spaced apart ribs that extend upwardly from the bottom of the sill track cavity and longitudinally along the length of 5 the sill cavity.

5. A sill as claimed in claim 4, wherein the pair of ribs are provided on one of the sill parts. 10

6. A sill as claimed in claim 5, wherein an upper part of said sill cavity has a rib that extends downwardly to provide a sill trolley side thrust bearing surface that extends longitudinally along the length of the sill cavity, and acts, in use, to minimize lateral cranking of 15 the sill trolley that may be caused by the weight of door panels carried thereby when the door panels are opened.

7. A sill as claimed in claim 6, wherein said rib that extends downwardly, is provided on the same one of said 20 parts as the pair of ribs.

8. A sill as claimed in any one of the preceding claims, and substantially as herein described with reference to the accompanying drawings. 25 30 H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 23/03/06 ABSTRACT A sill (5) for a bi-fold door assembly (1) has a two part sill (5) with a first part defining an outside part of an 5 elongate sill track cavity (19). A second part of the sill (5) defines an inside part of the cavity (19). The first part and the second part can be assembled together to define the sill (5) and the cavity (19). A sill trolley (11) can be received within the cavity (19) and 10 the trolley (11) can carry the weight of at least one door panel, and can traverse along the cavity (19). When the first part and the second part are assembled together a trolley (11) can be held captive in the cavity (19) to traverse the cavity (19). An opening (21) is defined in 15 the upper surface of the sill (5) and enables the weight of the at least one door panel to be carried by the trolley via a connection between the at least one door and the trolley (11) within the cavity (19). H:\deboram\keep\specifications\NZ Divisional 2 - A sill for a bi-fold door assembly.doc 22/03/06