AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Height-adjusting Assembly Applicant: Glenn Ranald Keen The invention is described in the following statement: 2 HEIGHT-ADJUSTING ASSEMBLY Field of the Invention. The present invention relates generally to the field of height adjustment of posts and in particular to the height adjustment of stumps to assist with levelling of 5 buildings following ground movement. Background Art. Many buildings in Australia, particularly timber houses, are not built directly onto a concrete slab but are supported by stumps which are in turn supported by concrete footings. This provides not only for below-floor ventilation but also 10 provides a 'crawlspace' between the ground and the floor of the building. In warmer climates, houses are often built on relatively tall stumps, such that the 'crawlspace' is of such a height as to allow a person to walk underneath the house. These types of high-set timber homes are particularly popular in Queensland. 15 The stumps provide support for the flooring of the building and can be made from a number of different materials, the most common being timber, steel, concrete or bricks. During construction of a building, a concerted effort is made when setting the stumps to ensure that the tops of the stumps are level, so that the flooring and thus the whole building is level. 20 However, once construction has been completed and over the lifetime of the building, environmental factors can contribute to the stumps, and therefore the building, no longer being level. Uneven stump height can be as a result of varying vertical movement (either upwards or downwards) of individual stumps. An environmental factor which can contribute to uneven stump height 25 over time is instability in the soil - during dry weather, soil dries out and shrinks, during wet weather, soil expands. Therefore, in regions prone to extremes of weather, such as prolonged dry spells followed by tropical downpours, soil instability can be a major factor effecting stump levels. Other environmental factors which can contribute to uneven stump 30 levels include seismic events, such as earthquakes and tremors. Volcanic activity, landslides and mine blasts are other events which cause earth movement that can contribute to uneven stump levels. High wind conditions such as cyclones and tornadoes can result in 3 uneven stump levels, however, less extreme high wind conditions can also have a detrimental effect on stump levels. A number of stump adjustment devices are known in the art. However, these devices are not rated to cope with the required structural loads and as a result, in 5 due course, can fail. Therefore, it would be an advance in the art to provide an assembly for readily adjusting the height of house stumps which is easily accessible and also provides sufficient loading strength. It will be clearly understood that, if a prior art publication is referred to 10 herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. Summary of the Invention. The present invention is directed to an assembly for adjusting the height of building stumps, which may at least partially overcome at least one of the 15 abovementioned disadvantages or provide the consumer with a useful or commercial choice. With the foregoing in view, the present invention in one form, resides broadly in an assembly for in situ adjustment of the effective length of a stump, the assembly comprising adjustment means, wherein the adjustment means includes: 20 a) an externally threaded member; b) an internally threaded member through which the externally threaded member of sufficient length to provide for height adjustment of the stump threadably engages; and c) a stump cap portion which, in use, is associated with the upper 25 end of the stump and relative to which the internally threaded member is mounted; such that rotation of the internally threaded member results in the externally threaded member moving through the internally threaded member, thereby adjusting the effective length of the stump. 30 The assembly of the present invention can be utilised for any situation where incremental changes to the effective length of a post, such as a stump or pylon may be required. The assembly therefore has broad application in the building industry and is particularly suitable for use in connection with house stumps.
4 The externally threaded member can be of any suitable thickness and strength. Preferably the externally threaded member is a threaded rod of a suitable nominal diameter and pitch. A threaded rod having a thread size of M30 x 3.5 is particularly preferred. 5 The internally threaded member can be an article of any shape or size which has, or can be provided with, an internally threaded hole through which the externally threaded member can threadably engage. In a preferred embodiment the internally threaded member is a nut. The nut can be any type of nut known in the art, including a two-sided, square or hex nut. In a particularly preferred embodiment, the 10 nut is a hex nut. The internal thread of the internally threaded member can be any thread suited to threadably engage with the'externally threaded member. It is particularly preferred that the internal thread is suited to threadably engage a threaded rod having a thread size of M30 x 3.5. Further, the pitch of the thread may be adjusted to provide 1.5 small adjustments or relatively rapid length adjustments. The stump cap portion provides support for the assembly on the upper surface of a stump to which the assembly is mounted. The stump cap portion is preferably a rigid plate of metal with a hole in the centre. In one embodiment, the hole is threaded such that the stump cap portion is additionally an internally threaded 20 member. In an alternative embodiment, an internally threaded member is mounted in the hole of the stump cap portion. Where the stump cap portion is a metal plate, the thickness of the metal plate can be varied, with a thicker plate providing the assembly with a greater load capability than a thinner plate. Additionally, the size of the internally threaded 25 member mounted relative to the stump cap portion can be varied, with a larger member also contributing to a greater load capability than a smaller member. Typically, the stump cap portion is a metal plate which is initially in two pieces and the internally threaded member has a groove on its outer surface, such that the groove encircles the member and the pieces of the stump cap portion can be 30 fitted into the groove and joined to form a rigid collar for the body. The assembly is then mounted to a stump via its collar. To ensure a good fit of the metal plate into the groove, the size of the groove can be varied for consistency with the thickness of the metal plate.
5 The internally threaded member and stump cap portion of the assembly can each be made from a suitable metal. Such metals include zinc and steel and their galvanised counterparts. Preferably, for compatibility, the internally threaded member and stump cap portion are made from the same metal. 5 The assembly can be mounted onto a stump by a variety of means, dependent on the material from which the stump is made. Where the stump is structural hollow section (SHS) steel, the stump cap portion can be welded to the top of the SHS steel stump. Where the stump is, for example, brick or concrete, then the stump cap portion can be bolted to the top of the stump, with provision of a hollow in 10 the top of the stump to allow for vertical movement of the externally threaded member during effective length adjustment of the stump. In alternative embodiments, the assembly can be mounted relative to the top of a stump, such that there is a clearance between the assembly and the top of the stump. In such embodiments, the top of the stump can have a hollow to allow for 15 vertical movement of the externally threaded member during effective length adjustment of the stump. Alternatively, the assembly can be mounted relative to the top of a stump, such that there is sufficient clearance between the assembly and the top of the stump for vertical movement of the externally threaded member during effective length adjustment of the stump without the need for a hollow in the top of 20 the stump. The assembly thus provides a means for individual adjustment of the effective length of a stump where such adjustment is required. Brief Description of the Drawings. Various embodiments of the invention will be described with reference 25 to the following drawings, in which: Figure l is a top view of two portions of metal plate which join to form a stump cap portion for an assembly according to an embodiment of the invention. Figure 2 is a side view of a nut to be used as an internally threaded member according to an embodiment of the invention. 30 Figure 3 is a top view showing one portion of metal plate fitted around a nut to form an assembly according to an embodiment of the invention. Figure 4 is a top view of the embodiment shown in Figure 3, with both portions of the metal plate fitted around the nut.
6 Figure 5 is a side view of the embodiment shown in Figure 4. Figure 6 is a side view of the embodiment of Figure 5 in combination with a threaded rod. Figure 7 is a side view of the embodiment of Figure 6 attached to a 5 stump. Detailed Description of the Preferred Embodiment. Referring to Figure 1, a top view of two portions of metal plate 10, 10' which join to form a stump cap portion for an assembly according to an embodiment of the invention are shown. Each metal plate 10, 10' has a semi-circular notch 12, 12' 10 to enable the metal plates 10, 10' to be mounted around an internally threaded member (not shown). Referring now to Figure 2, a side view of a nut 14 to be used as an internally threaded member according to an embodiment of the invention is shown. The nut 14 is a hex nut with an internal thread 16 and a groove 18 which encircles the 15 nut 14. Additionally the top and base of the nut 14 and the top and base of the groove 18 are chamfered 19. Chamfering 19 of the nut 14 and groove 18 prevent binding of the assembly under load. Figure 3 is a top view showing one portion of metal plate 10 fitted around a nut 14 as part of the process towards forming adjustment means according to 20 an embodiment of the invention. The nut 14 has an internal thread 16 and is chamfered 19. The second plate 10' with semi-circular notch 12' is shown prior to fitting around the nut 14. A top view of the embodiment of Figure 3 is shown in Figure 4, with the second plate 10' fitted around the nut 14 to form a stump cap portion to which an 25 internally threaded member is mounted according to an embodiment of the invention. The plates 10, 10' are welded along the join lines 20 and 20' to secure the plates 10, 10' in position around the nut 14. A side view of the stump cap portion to which an internally threaded member is mounted of Figure 4 is shown in Figure 5 with features in Figure 5 30 corresponding to features in Figure 4 numbered similarly. Referring now to Figure 6, there is shown a side view of adjustment means according to an embodiment of the invention. The adjustment means comprises an externally threaded rod 22 which is threadably engaged through a nut 14 7 with an internal thread 16. The nut 14 has a groove (not visible) in which a stump cap portion comprising two metal plates 10, 10' is fitted. An adjustment means according to an embodiment of the invention attached to a stump 26 is shown in Figure 7. The adjustment means comprises an 5 externally threaded rod 22 which is threadably engaged through a nut 14 with an internal thread 16. The nut 14 has a groove (not visible) in which a stump cap portion comprising two metal plates 10, 10' is fitted. The stump cap portion 10, 10' is attached to the upper end 24 of a stump 26. In this embodiment, the stump 26 is SHS steel shown in cross section. 10 From the foregoing it can be seen that the adjustment means of the present invention provides an easily accessible, load-bearing means for adjusting the effective length of a stump. In the present specification and claims, the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers 15 but does not exclude the inclusion of one or more further integers. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an 20 embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be 25 understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art. 30