AU2019236679A1 - A Roller Assembly for Sliding Doors - Google Patents

Abstract

A Roller Assembly for Sliding Doors A roller assembly for a sliding door has an elongate outer housing; a carriage adjustably mounted within a compartment in the housing, including an inner housing in which a pair of rollers joined by a mid-section, with a lower segment of each roller able engage a rail track; and a mechanism operable to move the carriage to one or other end wall of the outer housing to adjust the carriage towards and away from lower edges of the housing, and adjust the axis of each roller between positions towards and away from the lower edges and thereby position the lower segment of each roller between an upper rail track engaging position adjacent to the lower edges of the outer housing and a lower rail track engaging position below or further below the lower edges of the outer housing. r(DiN C)t

Description

A Roller Assembly for Sliding Doors

Field of the Invention [001] This invention relates to a roller assembly for a sliding door.

Background to the Invention [002] Rollers allow sliding doors to be moved horizontally, in a substantially vertical plane. Design features that make a roller easier to use and adjust, or enable installation or structural improvements, provide competitive advantages to door manufacturers.

[003] Roller mounted sliding doors often feature glass panels, to provide a sense of space by allowing the surrounding scene to be viewed, rather than blocked by the door. It is therefore desirable to minimise the width of the peripheral frame of the sliding door, including the frame portion that defines an aperture for accommodating a roller arrangement. In order to suit the widest variety of applications, this is accomplished by using a low profile roller arrangement that is adjustable between a minimum height and a maximum possible height.

[004] Sliding doors are becoming larger and heavier, with higher inertia and required operating efforts. One way to counteract this trend is to use larger diameter rollers. However, this directly contradicts the requirement for a low profile, and there is a need for roller arrangements that enable both requirements to be optimised.

[005] The present invention seeks to provide a roller assembly for a sliding door that, at least in preferred forms, provides an enhanced balance between enabling a low profile and reduced rolling resistance.

2019236679 25 Sep 2019

Broad Summary of the Invention [006] The present invention provides a roller assembly by which a sliding door is mountable so as to be able to slide along a rail track in opening and closing. Relative to a three-axis coordinate system having x- and y-axes disposed in a horizontal plane and a vertical z-axis perpendicular to the horizontal plane, the roller assembly has an elongate form that in a usual in use orientation has ends spaced longitudinally parallel to the x-axis and sides that are spaced laterally parallel to the y-axis and that have upper and lower edges spaced parallel to the z-axis, with direction terms, and their variants, such as longitudinal, lateral, upper, upwardly, lower, down and downwardly having a corresponding meaning throughout this disclosure. The assembly has:

(i) an elongate outer housing with laterally spaced sidewalls extending between the longitudinally spaced ends and joined by at least one connecting element connected between respective upper edges and by a respective end wall at each end, with the outer housing having a downwardly open compartment defined between the sidewalls and the end walls;

(ii) a carriage assembly adjustably mounted within the compartment and including an elongate inner housing in which each of a pair of rollers is mounted in a downwardly open enclosure, the inner housing has longitudinally spaced opposite end sections joined by a mid-section with each roller of the pair rotatable on a respective lateral axis in a respective end section, with a lower segment at a lower peripheral portion of each roller located in relation to a respective lower edge of each sidewall of the outer housing to enable engagement of each roller with a rail track to enable sliding of a door in which the roller assembly is installed; and (iii) an adjustment mechanism operable to move the carriage assembly towards one or other end wall of the outer housing and thereby adjust the carriage assembly towards and away from the lower edges of the sidewalls of the outer housing, and correspondingly adjust the axis of each roller between positions towards and away from the lower edges of the sidewalls of the outer housing and thereby position the lower segment of each roller between an upper rail track engaging position adjacent to the lower edges of the sidewalls of the outer housing and a lower rail track engaging position below or further below the lower edges of the sidewalls of the outer housing.

2019236679 25 Sep 2019 [007] The inner housing preferably is mounted in the outer housing by at least one sidewall of the outer housing and the adjustment mechanism defining a respective one of oppositely inclined, adjustably overlapping guide ways in each of which a projection on the inner housing is engaged. Preferably each sidewall of the outer housing defines a respective one of laterally inline, similarly inclined guide ways, with the adjustment mechanism then having two laterally inline guide ways that are oppositely inclined relatively to the guide ways of the outer housing. A respective lateral projection on the inner housing may engage in each pair of overlapping guide ways of the outer housing and the adjustment mechanism, or a single projection comprising a laterally extending adjustment pin may have each of its opposite ends engaged in a respective pair of overlapping guide ways of the outer housing and the adjustment mechanism. The adjustment mechanism may be operable to pull longitudinally the projection, the respective projections or the adjustment pin and thereby longitudinally pull the inner housing towards one end of the outer housing and thereby adjust the projection relative to the guide ways so the inner housing and the rollers move downward or upward, respectively, to vary the lower segment of each roller below the lower edge of the outer housing sidewalls. Alternatively, the adjustment mechanism may be operable push the projection, the respective projections or the adjustment pin and inner housing towards the other end of the outer housing and thereby adjust the projections relative to the guide ways so the inner housing and the rollers move upward or downward, respectively, to vary the lower segment of each roller below the lower edge of the outer housing sidewalls. In each case, the direction is dependent on the respective relative inclinations of the guide ways.

[008] In a preferred form of the roller assembly, each of the rollers has a diameter within a diameter range determined by an adjustment range over which an axis of each roller is able to be moved by the adjustment mechanism towards and away from the lower edge of each side wall of the outer housing. At least where each roller has a diameter at or close to the upper end of the diameter range, the enclosure in which each roller is mounted may be

2019236679 25 Sep 2019 upwardly open whereby, with the lower segment of each roller in the upper position, each roller has an upper segment at an upper peripheral portion located in a respective upwardly open aperture between upper edges of the sidewalls of the inner housing.

[009]. The sidewalls of the outer housing may connected together or linked across the respective upper edges by at least one connecting element or link. However, whether or not this is the case, the compartment of the outer housing may be upwardly open above each roller such that, with each roller having a diameter at the upper end of the diameter range and having the respective lower segment in the upper position, the upper segment of each roller is located in a respective upwardly open aperture between upper edges of the sidewalls of the inner housing.

[010] The preferred ability is to allow the rollers to adjust, or to be adjusted, to project upwardly into at least one upwardly open aperture, such as a respective upwardly open aperture, between the upper edges of the sidewalls of the outer housing. This facilitates larger roller being used in the carriage assembly of the roller assembly, at least compared to an arrangement where the roller diameter is restricted by consecutive top walls of the outer and inner houses.

[011] As indicated, the inner housing is elongate and has opposite end sections and a mid-section; with the end sections joined by the mid-section. In each end section of the inner housing, there is a respective roller of a pair of rollers, with each roller rotatable on a respective axis extending laterally with respect to each of the outer housing and the inner housing. In one arrangement, each roller is contained within an enclosure defined by the respective end section of the inner housing, with each enclosure downwardly open to enable the lower segment at the lower peripheral portion of the roller to be located below a lower edge of each sidewall of the outer housing. Most preferably each enclosure also has an upwardly open aperture to enable the respective roller to be adjustable so a horizontal tangent to an upper peripheral portion of the respective roller is at least adjacent to, or

2019236679 25 Sep 2019 substantially in a plane coincident with an upper surface of, the at least one connecting element of the outer housing.

[012] Where each end section of the inner housing defines a respective enclosure, each enclosure may include a substantially parallel pair of sidewalls that extend longitudinally away from the mid-section, in the opposite direction to the sidewalls of the other end section. The arrangement preferably is such that each of the sidewalls of each end section is substantially parallel and adjacent to a respective sidewall of the outer housing. The sidewalls of each end section may be joined together by an end wall that extends along respective edges of the sidewalls remote from the mid-section. Each end wall may extend from a lower edge of each sidewall to a respective upwardly open aperture at or adjacent to an upper edge of each side wall of the end section, such as at an upwardly open aperture of the enclosure. The roller of each end section most preferably has an axle that is rotatable on a lateral axis perpendicular to the sidewalls of the respective end section, with the axle having each of its ends engaged in a journal in each of the end section sidewalls.

[013] The carriage assembly may be pivotally mounted in the outer housing. The carriage assembly preferably is mounted to pivot on a lateral pivot axis that is perpendicular to the sidewalls of the outer housing. The pivot axis may be in a central part of the mid-section of the inner housing, with the pivot axis most preferably located substantially at a centre of symmetry for the carriage assembly. The pivot axis may be defined by a pivot pin pivotally engaged with the mid-section of the carriage assembly, with the pivot pin having each of its opposite ends engaged with a respective sidewall of the outer housing. In one convenient arrangement, the pivot pin comprises the adjustment pin detailed above as enabling the adjustment mechanism to move the inner housing towards one or other end wall of the outer housing and thereby adjust the inner housing towards and away from the upper edges of the side walls of the outer housing.

2019236679 25 Sep 2019 [014] The inner housing may be of integral form, or comprise two integrally formed parts joined on a central plane parallel to the x- and z-axes. The inner housing may be produced from suitable engineering plastics materials, with these particularly suitable, as they are significantly stronger in compression than in tension. Various grades of nylon are preferred. The mid-section may be solid, with the side walls of each end section projection longitudinally from the mid-section, with a respective side wall of each end section extending from a respective side portion of the mid-section where the inner housing comprises separately formed parts that are joined on a central plane. However, it is preferred that the mid-section comprises a plurality of longitudinally extending bands that are spaced vertically to define a plurality of laterally open longitudinally extending slots between the bands. As indicated, the carriage assembly may be pivotally mounted in the outer housing, preferably on a lateral pivot axis that is perpendicular to the sidewalls of the outer housing, such as with the pivot axis most substantially at a centre of symmetry for the carriage assembly. For this, the carriage assembly may be able to pivot on a laterally extending pivot pin, preferably the above mentioned adjustment pin, with the pin either extending through a bore through the midsection or a recess in an upper surface of the mid-section is able to receive the pivot pin by a firm snap-fit engagement of the pin in the recess.

General Description of the Drawings [015] In order that the invention may be understood more readily, description now is directed to the accompanying drawings, in which:

Figure 1 is a perspective view of one embodiment of a roller assembly according to the invention, by which a sliding door is mountable so as to be able to slide along a rail track in opening and closing;

Figure 2 is an exploded perspective view of the roller assembly of Figure 1; Figure 3 is a top plan view of the roller assembly of Figure 1;

Figure 4 is an underside plan view of the roller assembly of Figure 1;

Figure 5 is a side elevation of the roller assembly of Figure 1, shown in a first condition;

Figure 6 is an end elevation, from the left of Figure 5, with the roller assembly in the first condition;

2019236679 25 Sep 2019

Figure 7 corresponds to Figure 5, but with the roller assembly in a second condition;

Figure 8 corresponds to Figure 6, but with the roller assembly in the second condition and as seen from the right of Figure 7;

Figure 9 is a sectional view taken on line A-A of Figure 3, but showing a modified form of an internal component of the roller assembly; and

Figure 10 shows alternative detail related to a modification of the roller assembly as seen in Figure 2.

Detailed Description of the Drawings [016] In Figures 1 to 9 there is shown a roller assembly 10 by which a sliding door (not shown) is mountable so as to be able to slide along a rail track (also not shown) in opening and closing. The assembly 10 is shown in a usual in use orientation relative to the depiction of a three-axis coordinate system shown and having x- and y-axes disposed in a horizontal plane and a vertical z-axis perpendicular to the horizontal plane, and the same applies to the components of the assembly 10 as shown in the exploded condition of Figure 2. As also can be appreciated from the Figures, the roller assembly 10 has an elongate form which, in that orientation, has ends spaced longitudinally, parallel to the x-axis, and sides that are spaced laterally parallel to the y-axis and have upper and lower edges spaced parallel to the z-axis. Directions terms, and their variants, such as longitudinal, lateral, upper, upwardly, lower, down and downwardly having a corresponding meaning throughout this disclosure are used in description of Figures 1 to 4 relative to the coordinate system.

[017] The roller assembly 10 has an elongate outer housing 12 that has laterally spaced sidewalls 14 extending between longitudinally spaced opposite ends comprising an adjustment end 15 and a remote end 16. The sidewalls 14 also are joined by respective end wall 18, 19 and by connecting elements comprising two top wall sections 20, 21 each adjacent to a respective end 15, 16 and two longitudinally spaced connecting lattice sections 22, 23. Each lattice section 22, 23 includes a central longitudinal rib 24 and a number of longitudinally spaced, lateral ribs 25. One lattice section

2019236679 25 Sep 2019 extends from the top wall section 20 adjacent to adjustment end 15 and is longitudinally spaced from the other lattice section 23 by a rectangular aperture 26 that has a longitudinal length that exceeds its lateral width. A second such aperture 27 is provided between the other lattice section 23 and the top wall section 19 at remote end 16 of outer housing 12. The outer housing 12 encloses a downwardly open compartment 28 defined between the sidewalls 14 and the end walls 18, 19, with the compartment 28 also opening upwardly through each aperture 26.

[018] The roller assembly 10 also includes a carriage assembly 30 adjustably mounted within the compartment 26 of the outer housing 12. The assembly 30 includes an elongate inner housing 32 in which a pair of rollers 34 is mounted. The inner housing 32 has longitudinally spaced opposite end sections 36 joined by a mid-section 38 with each roller 34 of the pair accommodated in a downwardly open enclosure 40 formed by the respective end section 36. Each end section 36 has a pair of laterally spaced sidewalls 42, each parallel to and adjacent to a respective sidewall 14 of the outer housing 12 and each having a horizontal lower edge 42a that provides an inline continuation with a horizontal lower surface 38a of the mid-section 38. Each enclosure 40 comprises a respective an end 38b of the mid-section 38, the sidewalls 42 and a respective end wall 44 joining the sidewalls 42. The roller 34 in each enclosure 40 is rotatable on a lateral axis of a respective an axle 46, with each end of axle 46 supported in a respective journal in each sidewall 42 of the respective end section 36 of the inner housing 32. The arrangement is such that a lower segment 48 at a lower peripheral portion of each roller 34 is located below a lower respective edge of each sidewall 14 of the outer housing 12 for engagement with a rail track to enable sliding of a door in which the roller assembly is installed.

[019] The roller assembly 10 includes an adjustment mechanism 50 operable to move the carriage assembly 30 towards one or other end wall 16, 19 of the outer housing 12 and thereby adjust the carriage assembly 30 towards and away from the upper edges, and correspondingly vary the lower segment 48 of each roller 34 below the lower edges 14a of the sidewalls 14 of the outer

2019236679 25 Sep 2019 housing 12. The mechanism 50 includes an elongate adjustment member 51 that extends longitudinally within the outer housing 12, adjacent to the aperture 26 and each of the lattice sections 22, 23, with the member 51 also straddling the upper longitudinal extent of the carriage assembly 30. The adjustment member 51 has an end section 52 that is nearer to the adjustment end 15 of the outer housing 12 and that is of inverted U-shape in end elevation to provide a parallel pair of laterally spaced plates and, extending longitudinally a parallel pair of laterally spaced flanges 53 between which a square nut 53a is secured against rotation by a respective tab 53b defined by each flange 53. From each flange 53, adjustment member 51 is continued longitudinally by a respective one of a laterally spaced pair of stiff connecting straps 54. At the end of adjustment member 51 remote from the adjustment end 15 of housing 12, each strap 54 ends at a respective inclined flange 55 that is angled down from the respective strap 54 and away from the adjustment end 15 of housing 12. Adjustment member 51 is movable longitudinally relative to outer housing 12 by an adjustment bolt 56 that passes longitudinally through a non-threaded bore 57 defined in the adjustment end 15 of outer housing 12, with the bolt 56 in threaded engagement in the nut 53a secured between the tabs 53b of the flanges 53 of member 51. The arrangement is such that clockwise (as viewed in Figures 6 and 8) and anti-clockwise rotation of bolt 56 moves nut 53a respectively towards and away from adjustment end 15 of outer housing 12, with the adjustment member 51 moving longitudinally with the nut 53a.

[020] Each inclined flange 55 defines a respective one of a laterally spaced pair of inline guide ways 58, with each guide way 58 angled similarly to the respective inclined flange 55. Also, each sidewall 14 of the outer housing 12 has a respective one of a laterally spaced pair of inline guide ways 59, with guide ways 59 angled similarly, but oppositely to the guide ways 58. The arrangement is such that each guide way 58 is adjacent to a respective guide way 59 and, due to their opposite inclinations, the pairs of adjacent guide ways 58, 59 overlap at a location along their lengths determined by the relative longitudinal position of the adjustment member 51 in outer housing. Additionally, an adjustment pin 60 has a respective end located in each pair of

2019236679 25 Sep 2019 adjacent guide ways 58, 59 at the overlap location, such that if the adjustment member is moved longitudinally in housing 12, by rotation of bolt 56, the overlap location and, hence, the adjustment pin 60 is raised or lowered, depend on the direction of rotation of bolt 56. Assuming bolt 56 has a right handed thread, anti-clockwise rotation as viewed in Figures 6 and 8 will move the adjustment member 51 away from the adjustment end 15, raising the overlap between guide way pairs 58, 59 and moving adjustment pin 60 to the top of each guide way of the pairs 58, 59, as shown for a guide way 59 and pin 60 in Figure 5. Clockwise rotation of bolt 56 results on the converse movements, moving the overlap and pin 60 to the bottom of each guide way of the pairs 58, 59, as is shown for a guide way 59 and pin 60 in Figure 7.

[021] The carriage assembly 30 is symmetrical about a vertical plane parallel to the Z-axis. At a mid-point along the upper surface of the assembly 30, the mid-section 38 is provided with an upwardly open, laterally extending recess 39 in which a mid-section of adjustment pin 60 is securely captured. As a consequence, the carriage assembly 30 moves in unison with the adjustment pin 60. Thus, as the adjustment member 51 moves longitudinally in outer housing 12, the carriage assembly 30 is moved longitudinally with the adjustment member 51. Also, as movement of adjustment member 51 causes adjustment pin 60 to be raised or lowered along the guide way pairs 58, 59, the carriage assembly 30 is correspondingly raised or lowered, such as respectively placing the roller assembly 10 in the raised condition shown in Figures 5 and 6 or the lowered condition shown in Figures 7 and 8, although any intervening positioning is possible.

[022] In the raised condition of Figures 5 and 6, the carriage assembly 30 is retracted up in outer housing12 so only a minimal lower margin of the inner housing 32 is below the lower edges of the sidewalls 14 of the outer housing 12. Thus, the lower edges 42a of the sidewalls 42 of each end section 36, and the lower surface 38a of the mid-section, of inner housing 32 are exposed. In contrast, in the lowered condition of Figures 7 and 8, the carriage assembly 30 is lower relative to outer housing 12 so a substantially greater lower margin of the inner housing 32 is below the lower edges 14a of the

2019236679 25 Sep 2019 sidewalls 14 of the outer housing 12. The rollers 34 retain their positional relationship relative to the inner housing 32 and they do not have a necessary lower segment below the lower edges 42a of the respective sidewalls 42 of each end section 36 of inner housing 32. However, each of rollers 34 has a minimal segment 48a at its lower peripheral portion that is below the lower edge of the sidewalls 14 of the outer housing when the carriage assembly 30 is in the raised condition of Figures 5 and 6, and a maximal segment 48b at its lower peripheral portion below the lower edge of the sidewalls 14 when the carriage assembly 30 is in the lowered condition of Figures 7 and 8, as a consequence of raising or lowering the carriage assembly 30 by the adjustment mechanism 50. The rollers 34 are not visible in side elevation views of assembly 10 due to them being obscured by the sidewalls 42 of each end section 36. Thus each of the segment variants 48a and 48b are shown for ease of illustration by solid shading in Figure 9, even though Figure 9 shows the assembly 10 in the raised condition for which only variant 48a is applicable, with the variant 48b not fully applying until the lowered condition is achieved.

[023] The rollers 34 are not visible in either of the side elevations of Figures 5 and 7 since, in the illustrated arrangement, the rollers do not extend below the lower edges 42a of the sidewalls 42 of the end sections 36. This arrangement is preferred as it minimises the risk of the rollers 34 being damaged as the assembly 10 is fitted to a door before the door is installed. However, because of the arrangement, each section 36 is recessed upwardly above the lower edges 42a at the lower extent of each end wall 44 to provide an opening 62 below an edge 62a, shown as of concave, arcuate form in the illustrated arrangement, that is offset from and provides clearance above a rail track along which rollers are able to travel. Correspondingly, the lower edge of adjustment end wall 18 of outer housing 12 defines an opening 18a, below concave edge 18b and, while not visible, a similar opening is provided at the lower edge of remote end 19 of housing 12. As shown in most clearly in Figure 2, the rollers are in the form of gate track wheels that have a central peripheral channel enabling them to straddle and ride along a raised rail track.

2019236679 25 Sep 2019 [024] As indicated, each roller 34 is accommodated in a respective downwardly open enclosure 40 comprising a respective an end of the midsection 38, the sidewalls 42 and a respective end wall 44 joining the sidewalls 42. However, in addition to being downwardly open, each enclosure 40 also is open at the top, directly above the centre of the respective roller. The open top is created by provision of a rectangular opening 63 that has its major dimension extending longitudinally above the respective roller 34. Also, the substantially similar distance between centres for the rollers 34 and the openings 63 is substantially the same as the distance between centres for the apertures 26 and 27 at the top of outer housing 12. Additionally, the adjustment mechanism 50 is adjusted relative to outer housing 12 and the carriage assembly 30 such that, with the roller assembly in the first or raised condition shown in Figures 5 and 6, each roller 34 is substantially centred in relation to a respective one of apertures 26 and 27, as is evident from Figurel and 3, while Figure 9 shows the rollers close to that raised condition.

[025] With reference to Figure 9, it is apparent that the inner housing 32 of the carriage assembly 30 shown differs from the form of the housing 32 shown in other Figures, most clearly in Figure 2. Figure 9 most clearly illustrated the arrangement as the roller assembly approaches and reaches the first or raised condition. In the form shown in Figure 9, the rollers 34 have an upper segment 64 (shown in solid shading) at an upper peripheral portion that is within the respective opening 63 at the top of the inner housing 32, while that upper segment 64 protrudes into the respective one of apertures 26 and 27 at the top of outer housing 12, at least to the extent of the thickness of the top structure of housing 12 between the upper edges of the sidewalls 14 of outer housing 12. Indeed, it is apparent in Figure 9 that if the respective end of the mid-section 38 and the curved upper extent of the respective end wall 44 were formed with a slightly larger radius of curvature, and/or the openings 63 were longitudinally wider, the upper segment 64 could extend further into the respective aperture 26, 27. As a consequence, the rollers 34 are able to be of larger diameter than would be the case if openings 63 and apertures 26, 27 were not provided.

2019236679 25 Sep 2019 [026] As the carriage assembly 30 is pivotally mounted in the outer housing on the adjustment pin 60. Thus, in the preferred arrangement illustrated, the carriage assembly 30 is able to pivot even, at least to a degree, in the fully retracted or raised condition shown in Figures 5 and 6. As a consequence the arrangement is able to promote even load distribution between rollers 34.

[027] As indicated, the inner housing 32 may be of integral form. The inner housing may be produced from suitable engineering plastics materials, with various grades of nylon preferred. While the mid-section 38 is solid in the arrangement shown in Figure 9, the inner housing 32 shown in Figures 1 to 8 has a mid-section comprising a plurality of longitudinally extending bands 65 that are spaced vertically to define a plurality of laterally open longitudinally extending slots 66 between the bands 65. The arrangement enables a high panel load capability. It is desirable that the rollers 34 can support the highest possible load, so it can be specified in the largest number of potential applications. A heavier section for the inner housing 32 of the carriage assembly 30 would potentially conflict with the requirements of economical manufacture.

[028] To achieve a suitable distributed roller loading, the roller assembly 10 require multiple rollers 34 to support a panel, particularly when a single roller would not have required mechanical strength to support the rated load of a door with which the assembly 10 is to be used. When multiple rollers are required, a mechanism must be provided to evenly distribute the load, preventing a single roller from being subjected to a potentially damaging load. The distribution of load between several rollers also reduces the load on the track substrate. This can be further improved by increasing the horizontal spacing between rollers, to distribute the point loading imposed by the rollers on the track. The roller assembly 10 of the invention is compatible with the conflicting requirements, although extending the roller spacing substantially increases the bending moment imposed on the carriage assembly 30, between the central pivot provided by the adjustment pin 60 and the spacing between centres for rollers 34. The height of the carriage assembly 30 cannot be increased without compromising the previously mentioned low profile

2019236679 25 Sep 2019 requirement. However, production of the inner housing 32 of the carriage assembly 30 of an engineering plastics, such as nylon, due to them being significantly stronger in compression than tension, enables the design of the assembly 30 to be optimised to resist the tensile forces generated by the arrangement of the assembly 30. In this regard, wall sections are able to be kept relatively constant to discourage formation of voids that can form in thick sections and potentially significantly compromise mechanical strength. Each wall 44, which preferably has a constant section, extends the full lateral width of the carriage assembly 30, interconnecting the respective sidewalls 42 of the enclosure 40 at each end of the carriage assembly 40. This forms the extreme fibre of what is effectively a beam, to resist tensile forces generated by loads applied to the pivot at adjustment pin 60. Overall, the carriage assembly 30 is well suited to support a permanent static load, but yield under the much higher, temporary impact loads that such as may, for example, be experienced during installation.

[029] The component of the roller assembly 10 that is most affected by applicable constraints is the carriage assembly 30 which functions to interconnect the rollers 34, while providing an anchor point at recess 39 for interconnection with the outer housing 12, via the adjustment mechanism 50, effectively a height adjustment mechanism. The central pivot at recess 39 provided by the adjustment pin 60 connects the carriage assembly 30 to the height adjustment mechanism 50, allowing the assembly 30 to gimbal until the load is equally distributed over both rollers 34. The recess 39 is upwardly open so that it can be snapped onto, and off, the adjustment pin 60, without requiring the entire assembly 10 to be removed.

[030] The roller assembly 10 has rollers 34 that have a diameter at or toward the upper end of a possible diameter range for different sized rollers able to be used. That range of roller diameters is determined by an adjustment range over which an axis of each roller is able to be moved by the adjustment mechanism 50 towards and away from the lower edge of each side wall 14 of the outer housing 12. It is with such larger rollers 34 that, with the lower segment of each roller in the upper position each roller has an upper segment

2019236679 25 Sep 2019 at an upper peripheral portion located in a respective upwardly open aperture between upper edges of the sidewalls of the inner housing and even between the upper edges of the sidewalls of the outer housing. However, the working relationship between the outer housing, the carriage assembly and the adjustment mechanism is such that rollers with smaller diameters can be used, albeit without the benefit of lesser rolling resistance of larger rollers. With each roller size, the adjustment mechanism is operable to position the lower segment of each roller between an upper rail track engaging position adjacent to the lower edges of the sidewalls of the outer housing and a lower rail track engaging position below or further below the lower edges of the sidewalls of the outer housing. In the upper position, the lower segment may be slightly below the lower edges of the sidewalls 14 of the outer housing 12 or, by recessing the outer housing at the adjustment end 15 and the remote end 16, slightly above those lower edges of the outer housing sidewalls.

[031] In the arrangement of Figure 2, each of flanges 53 are shown as having a slot 53c that is formed to provide a respective one of opposed tabs 53b between which nut 53a is held against rotation as bolt 56 is rotated through the nut 53a. In the alternative detail of Figure 10, corresponding details shown have the same reference numerals, and description of Figure 10 is limited to matters of difference from Figure 2. In Figures 10, the slots 53c are lengthened and while no tabs need to result from forming the slots 53c, tabs similar to those of Figure 2 could be provided, if required. In the case of Figure 10, a respective side of nut 53a is accommodated in each slot 53c and is constrained against rotating as bolt 56 is rotated through the nut 53a by the nut being held in either the upper or lower end of each slot 53c. To enable a selection between the upper or lower ends of the slots 53c, the non-threaded bore 57 defined in the adjustment end 15 of outer housing 12 has a figure-8 form such that the bolt 53a can be inserted through either an upper part adjustment 57a or a lower adjustment part 57b of the bore 57, depending on whether the nut 53a is to be in the upper or lower ends of slots 53c, respectively. The arrangement enables the bolt 53a to be positioned at a lower or higher adjustment level. The lower adjustment level corresponds to a standard height for the roller assembly 10 and a door in which it is installed by

2019236679 25 Sep 2019 a door fabricator. However, most door fabricators have pre-set tools for punching holes in a door extrusion to allow access to adjust the roller height, while some door systems use punches that have punch holes for a higher adjustment height. This figure-8 form for bore 57 allows the bolt 56 to be removed and repositioned to provide suitability for a wider range of door systems.

[032] The roller assembly of the invention may be installed by being fitted, in the indicated in use orientation, in a groove or opening formed along the bottom edge of a sliding door, typically the adjustment end of the outer housing sufficiently close to a side of the door to enable accesses to the bolt of the adjustment mechanism. A second assembly may be similarly installed for access from the other side of the door. In each case the rollers of the, or each, assembly will support the door adjacent to the side, or respective side, of the door. In a variant of the assembly, suited for a wide door necessitating more central roller support, one or each roller assembly installed adjacent to a side of the door may be of a longer form having an extended outer housing in which two carriages assemblies are longitudinally spaced and adjustable by a common adjustment mechanism. The adjustment mechanism may extend from the adjustment end to the nearer carriage assembly and interact with a nearer one of the two carriage assemblies in the same manner as described herein for a roller assembly with a single carriage assembly. However, from the flanges 55 with guideways 59 for the nearer carriage assembly, the straps have parallel extensions to the further carriage assembly, with each strap extension having an inclined flange with an inclined guide way that interacts similarly with the further carriage assembly in the same manner as described herein for a roller assembly with a single carriage assembly. Adjacent to the further carriage assembly, the outer housing has oppositely inclined guideways in its sidewalls, while a further adjustment pin has each end inserted if the overlap between adjacent oppositely inclined guideways, with the further carriage assembly pivotally engaged with the mid-section of the further adjustment pin. The arrangement is such that each carriage assembly will be movable longitudinally in unison, and movable between the raised and lowered conditions in unison, with rotation of the one adjustment bolt in one or

2019236679 25 Sep 2019 other direction. However, at least where such dual carriage assemblies are to be installed in a door having a finish along the bottom edge that is not sufficiently linear, each assembly needs to be able to adjust slightly relative to the other to ensure the each roller of each assembly is sharing the load of the door. Accordingly it can be necessary to incorporate a linkage between the assemblies that enables the height of one to be adjusted slightly relative to the other during installation.

Claims (16)

1. Claims

   1. A roller assembly by which a sliding door is mountable so as to be able to slide along a rail track in opening and closing, wherein the roller assembly has an elongate form that has ends spaced longitudinally, sides spaced laterally and upper and lower edges; wherein the roller assembly has:

   (i) an elongate outer housing with laterally spaced sidewalls extending between the longitudinally spaced ends and joined by at least one connecting element connected between respective upper edges and by a respective end wall at each end, with the outer housing having a downwardly open compartment defined between the sidewalls and the end walls;

   (ii) a carriage assembly adjustably mounted within the compartment and including an elongate inner housing in which each of a pair of rollers is mounted in a downwardly open enclosure, the inner housing has longitudinally spaced opposite end sections joined by a mid-section with each roller of the pair rotatable on a respective lateral axis in a respective end section, with a lower segment at a lower peripheral portion of each roller located in relation to a respective lower edge of each sidewall of the outer housing to enable engagement of each roller with a rail track to enable sliding of a door in which the roller assembly is installed; and (iii) an adjustment mechanism operable to move the carriage assembly towards one or other end wall of the outer housing and thereby adjust the carriage assembly towards and away from the lower edges of the sidewalls of the outer housing, and correspondingly adjust the axis of each roller between positions towards and away from the lower edges of the sidewalls of the outer housing and thereby position the lower segment of each roller between an upper rail track engaging position adjacent to the lower edges of the sidewalls of the outer housing and a lower rail track engaging position below or further below the lower edges of the sidewalls of the outer housing.
2. 2. The roller assembly of claim 1, wherein the inner housing is mounted in the outer housing by at least one sidewall of the outer housing and the adjustment mechanism defines a respective one of oppositely inclined, adjustably overlapping guide ways in each of which a projection on the inner housing is engaged, with each sidewall of the outer housing defining a respective one of

   2019236679 25 Sep 2019 laterally inline, similarly inclined guide ways, with the adjustment mechanism having two laterally inline guide ways that are oppositely inclined relatively to the guide ways of the outer housing.
3. 3. The roller assembly of claim 2, wherein the lateral projection on the inner housing comprises a laterally extending adjustment pin that has each of opposite ends engaged in a respective pair of overlapping guide ways of the outer housing and the adjustment mechanism.
4. 4. The roller assembly of claim 3, where the adjustment mechanism is operable to pull the adjustment pin longitudinally and thereby longitudinally pull the inner housing towards one end of the outer housing and thereby adjust the projection relative to the guide ways so the inner housing and the rollers move downward or upward, respectively, to vary the lower segment of each roller below the lower edge of the outer housing sidewalls or, alternatively, operable to push the adjustment pin and inner housing towards the other end of the outer housing and thereby adjust the projections relative to the guide ways so the inner housing and the rollers move upward or downward, respectively, to vary the lower segment of each roller below the lower edge of the outer housing sidewalls.
5. 5. The roller assembly of any one of claims 1 to 4, wherein each of the rollers has a diameter within a diameter range determined by an adjustment range over which an axis of each roller is able to be moved by the adjustment mechanism towards and away from the lower edge of each side wall of the outer housing.
6. 6. The roller assembly of claim 5, wherein the enclosure in which each roller is mounted is upwardly open, and each roller has a diameter at or close to the upper end of the diameter range, whereby with the lower segment of each roller in the upper position each roller has an upper segment at an upper peripheral portion located in a respective upwardly open aperture between upper edges of the sidewalls of the inner housing.

   2019236679 25 Sep 2019
7. 7. The roller assembly of claim 6, wherein the sidewalls of the outer housing are connected together across the respective upper edges by at least one connecting element and the compartment of the outer housing is upwardly open above each roller such that, with each roller having a diameter at the upper end of the diameter range and having the respective lower segment in the upper position, the upper segment of each roller is located in a respective upwardly open aperture between upper edges of the sidewalls of the inner housing.
8. 8. The roller assembly of any one of claims 1 to 7, wherein each roller is contained within a respective enclosure defined by the respective end section of the inner housing, with each enclosure downwardly open, such as to enable the lower segment at the lower peripheral portion of the roller to be located below the lower edges of the sidewalls of the outer housing.
9. 9. The roller assembly of claim 8, wherein each enclosure includes a substantially parallel pair of sidewalls that extend longitudinally away from the mid-section, in the opposite direction to the sidewalls of the other end section, with each of the sidewalls of each end section substantially parallel to and adjacent to a respective sidewall of the outer housing and the sidewalls of each end section joined together by an end wall that extends along respective edges of the sidewalls remote from the mid-section and each end wall extending from a lower edge of each sidewall to a respective upwardly open aperture at or adjacent to an upper edge of each side wall of the end section, at an upwardly open aperture of the enclosure.
10. 10. The roller assembly of claim 9, wherein the roller of each end section is mounted on a respective axle so as to be rotatable on a lateral axis perpendicular to the sidewalls of the respective end section, with the axle having each of its ends engaged in a journal in each of the end section sidewalls.

    2019236679 25 Sep 2019
11. 11. The roller assembly of any one of claims 1 to 10, wherein the inner housing is of integral form, and produced from a suitable resilient engineering plastics materials, such as of nylon.
12. 12. The roller assembly of claim 11, wherein the mid-section is solid, with side walls of each end section projection longitudinally from the mid-section.
13. 13. The roller assembly of claim 11 or claim 12, wherein the mid-section comprises a plurality of longitudinally extending bands that are spaced vertically to define a plurality of laterally open longitudinally extending slots between the bands connecting areas of low stress at alternate ends.
14. 14. The roller assembly of any one of claims 1 to 13, wherein the carriage assembly is able to pivot on a laterally extending pivot pin, with the pin extending through a bore through the mid-section or a recess in an upper surface of the mid-section able to receive the pivot pin by a firm snap-fit engagement of the pin in the recess.
15. 15. The roller assembly of any one of claims 1 to 13, wherein the carriage assembly is pivotally mounted in the outer housing, on a lateral pivot axis perpendicular to the sidewalls of the outer housing, with the pivot axis most preferably located substantially at a centre of symmetry for the carriage assembly.
16. 16. The roller assembly of any one of claims 1 to 15, wherein the pivot axis is defined by a pivot pin pivotally engaged with the mid-section of the carriage assembly, with the pivot pin having each of its opposite ends engaged with a respective sidewall of the outer housing, with the pivot pin preferably comprising an adjustment pin enabling the adjustment mechanism to move the inner housing towards one or other end wall of the outer housing and thereby adjust the inner housing towards and away from the upper edges of the side walls of the outer housing.