A sanitary wash basin fixing screw anchor for brick, block or concrete solid walls

Abstract

A screw 1 suitable for fixing a wash basin to a wall 8, comprises a shaft having two threaded sections 1a, 5. The screw 1 may have a hexagonal drive point 2 at an end. There may be a further hexagonal

Description

The present invention relates to a double threaded screw anchor and nylon bushing for wash basin installation in solid walls. Background to the Invention Upon installation of a domestic wall mounted wash basin in a bathroom a wash basin is installed against either a brick, block or concrete solid wall or a partition wall of wood and plasterboard construction also known as a stud wall. The wash basin is generally made of ceramic with two circular or oval mounting holes in the rear for fixing it to the wall. The weight of wash basins can be anything between 5-30kgs or more so obtaining a secure fixing is necessary. In prior art, various devices have been used for anchoring a wash basin to a solid wall, specifically such devices require a pilot hole to be made in the solid wall of 14mm in diameter which then a plastic wall plug is inserted before the wash basin fixing screw is screwed in by utilising a hexagonal shank in the centre of the fixing screw anchor. The down side of these prior art devices are firstly having to drill a large Umm hole in a solid wall as there is a cost implication in purchasing such size masonry bits that generally most people will not have in a standard tool box also drilling such a size hole into potentially poor quality substrate such as old or soft brick can reduce the loading performance. As it is necessary to generally screw in these prior art devices by hand using a spanner on the hexagonal point in the centre of the fixing shaft, the time for installation and ultimately the cost is greatly increased. The negative environmental aspect of using two large plastic wall plugs of generally between 70-90mm in length and 14mm-15mm in diameter is also noteworthy. Upon installation of the wash basin fixing screw anchor, a bushing generally made of nylon will be placed between the ceramic wash basin and the metal thread to help keep the wash basin in place and reduce damage by direct contact with the screw thread. In prior art forms these generally -2- have a hexagonal top which can be turned with a spanner, such a design is not ideal when working in a tightly confines installation space the bushing may or may not have an eccentric cam to raise or lower the wash basin installation along the horizontal axis. Summary of the invention It is an object of the present invention to provide a double threaded screw which may be anchored directly into a brick, block or concrete solid walls without the use of plastic wall plugs and only using a much smaller 8mm pilot hole within the wall for the screw anchor. The surface coating of the fixing screw anchor may be Zinc Plating (ZP) or Hot Dipped Galvanised (HDG) or a ceramic coating. The ceramic coating is preferred as it is harder wearing and more resistant to damp or humid environments than the previous two methods. The double threaded fixing screw anchor has a hexagonal section in the centre like the prior art devices for a spanner to drive in the thread by hand. It also has a hexagonal top on the shaft for a 7mm hexagonal drive tool to be used with a power device, so that the screw anchor may be driven into the wall quickly. The double threaded screw consists of two types of thread. The first thread is a metric thread preferably M8 or M10 and the second thread has a high and low pitched helical thread at a wider distance apart for specifically screwing directly into brick, block or concrete without the need of a plastic wall plug. The overall length of the screw is between 120mm - 180mm with the metric thread being between 40mm-70mm and the concrete thread being between 50mm-80mm. The bushing is made of nylon and designed specifically for wash basin installations where generally the installer will have a confined workspace and lack of light due to the installation process of the wash basin. Hence the design is such that no longer does the installer have to use two spanners making the installation easier and quicker. For a better understanding of the present invention, reference will now be made by way of example, to the accompanying drawings, in which: Figure 1 is a front elevation view of the double threaded wash basin fixing screw; Figure 2 is a view of the double threaded wash basin fixing screw in a cross section of a solid wall; Figure 3 is a side view of the double threaded wash basin fixing screw with nylon bushing and flange nut securing the wash basin on a cross section of wall; Figure 4 is a front elevation view of the nylon bushing; Figure 4a is a rearview of the nylon bushing; Figure 4b is a side view of the nylon bushing; Referring to Figure 1 there is a wash basin fixing screw 1 with a metric thread 1a and a hexagonal top 2. The centre of the shaft has a hexagonal drive point 3 followed by a plain shaft 4 the concrete screw thread 5 has a raised helical pitch 6 and two lower helical pitches 7. Referring to Figure 2 there is a wash basin fixing screw 1 with a metric thread 1a and a hexagonal top 2. The centre of the shaft has a hexagonal drive point 3 followed by a plain shaft 4 the concrete screw thread 5 has a raised helical pitch 6 and two helical pitches 7. The installation is shown in a cross section of the solid wall 8 using a pre-drilled pilot hole 9. Referring to Figure 3 there is a wash basin fixing screw 1 with a metric thread 1a and a hexagonal top 2. The centre of the shaft has a hexagonal drive point 3 followed by a plain shaft 4 the concrete screw thread 5 has a raised helical pitch 6 and two lower helical pitches 7. The installation is shown in a cross section of the solid wall 8 using a pre-drilled pilot hole 9. The wash basin is shown in cross section 10. Wash basin 10 has a nylon bushing 11 to prevent damage to the ceramic basin by wash basin fixing screw 1. The nylon bushing 11 has protruding wings 11a and 11b and an eccentric cam 11 c for adjustment. Flange nut 15 secures the wash basin against wall 8. Referring to Figure 4 the nylon bushing 11 is shown with a diameter D1 of between 30-45mm, D2 15-25mm and a shaft hole 12 of which the diameter D3 is between 6-12mm. The top of the bushing is indicated with an arrow in the moulding 14 and height adjustment level numbers 13. The 5 top wing of the bushing 11a and the bottom wing of the bushing 11b Referring to Figure 4a the nylon bushing 11 has an eccentric cam 11 c and a shaft hole 12. Referring to Figure 4b the nylon bushing 11 has a wing on the bottom 11 a and one on the top 10 11b. The eccentric cam 11c and the shaft hole 12.

Claims

1. A wash basin fixing screw (1) for fixing a wash basin to a brick., block or concrete solid wall (8) comprising a single shaft with two different types of thread.

2. A wash basin fixing screw (1) with the top end having a hexagonal drive point (2)3. A wash basin fixing screw (1) with a metric thread (1 a) and a concrete screw thread (5) with a high pitch (6) and two lower pitches (7)4. A wash basin fixing screw (1) with a central hexagonal drive point (3) nearest the metric thread (1a) and a plain shaft section (4) nearest the concrete screw thread (5)5. A nylon bushing (11) with two wings (11a) and (11b)6. A nylon bushing (11) with an eccentric cam (11c)

Images