Brushing – scrubbing – and general cleaning – Implements – Mason's trowel or float
Reexamination Certificate
1999-12-02
2001-03-27
Talbot, Brian K. (Department: 1762)
Brushing, scrubbing, and general cleaning
Implements
Mason's trowel or float
C015S245100, C015S236080, C427S277000, C427S355000, C427S356000, C427S369000, C118S500000
Reexamination Certificate
active
06205610
ABSTRACT:
This invention relates to a tool suitable for spreading adhesive upon a substrate. The tool in a preferred form can be a trowel suitable for manual application and spreading of adhesive across a substrate which is being tiled with ceramic tiles. This application will be used to explain the invention but it will be appreciated that the invention is not limited to this specific application.
BACKGROUND OF INVENTION
In the case of tiling, a tile is pressed onto a number of ridges of adhesive and the ridges are collapsed thereby forcing adhesive into the space between the ridges. During this process air which was within the space between the ridges should be expelled along the valleys and vented to the surrounding room or area. In this way the substrate should become covered with adhesive and likewise for the tile face pressed towards the substrate.
The process of tiling typically utilises a trowel with an edge characterised by regularly spaced rectilinear indentations. The interspacing, width and extent of the indentations depend upon the adhesive and tiles being worked. Further the indentations and interspacing typically have a castellated appearance. An example is illustrated in FIG.
4
(
a
) of the accompanying drawings.
The prior known process of tiling has been found to be in practice not entirely satisfactory. It has been observed that under normal work practices some tiles may not be adequately adhered to a substrate surface and as a result the tiles may become loose or crack. Such a fault may not be found until after some months or years and may permit water to enter beneath the-tiles and lead to further problems. Consequently, often a loose or cracked tile can lead to a considerable problem which may be expensive to solve.
It is believed these problems may arise, at least partly, because in practice the substrate surface does not become uniformly covered with adhesive and as a consequence some parts of a tile are not adhered to the substrate. It is also believed that uppermost portions of adjacent ridges of adhesive spread out under the pressure of a tile being pressed to the substrate and contact and bridge the intervening space and may close the space between adjacent ridges of adhesive. Then the bridge of adhesive helps support the tile and resist the force pressing it into the adhesive and traps air underneath the tile.
As a result a void free of adhesive can be formed near the surface between adjacent ridges.
As will be appreciated, using a prior known trowel the adhesive is spread generally over and keyed into the substrate and then combed with the edge bearing the indentations thus forming ridges of adhesive. As the tile is pushed into place it is moved transverse to the ridges back and forth to collapse the ridges and expel the air from between the ridges of adhesive. With a large tile the surface area is significant and the required force to expel the air and collapse the ridges of adhesive is considerable and so proper setting of the tile may not be achieved.
OBJECT OF THE INVENTION
It is a proposed object of this invention to provide a tool to obviate or minimise at least one of the aforementioned problems, or at least provide the public with a useful choice.
BRIEF SUMMARY OF INVENTION
The tool described herein can be, in a preferred form, a trowel suitable for manual application and spreading of adhesive across a substrate which is being tiled with ceramic tiles. This application will be used to explain the invention but it will be appreciated that the invention is not limited to this specific application. Rather, once the invention is fully appreciated, it will understood that the invention is applicable to other applications where adhesive is spread in ridges across a substrate and an object is adhered to the substrate.
The invention may be said to reside, not necessarily in the broadest or only form, in a tool for spreading adhesive over a substrate, said tool including:
a blade supported by support means and the blade being moveable over the substrate such that a blade edge is slid over the substrate;
the blade edge having a set of spaced large indentations and at least one set of spaced smaller indentations extending into the blade edge, the smaller indentations extending into the blade less than any one of the large indentations and being interspaced between the large indentations so that in use large ridges of adhesive are formed interspaced with smaller ridges of adhesive.
From the above it will be appreciated that a trowel exhibiting the invention can have a blade with an edge having a first set of large indentations similar to prior known trowels that were previously mentioned. However, such a trowel can have a further set of smaller indentations in the interspace between the large indentations which extend into the blade less than the large indentations. As a result adhesive can be spread and formed into parallel ridges with adjacent ridges being of different heights.
In a preferred form the smaller indentations extend into the blade edge one tenth to one half the extent to which the large indentations extend into the blade edge. It will be appreciated that the ridges are sized to suit the particular application whilst also minimising the occurrence of voids proximal to the substrate.
In one preferred form, the large indentations are uniformly spaced along the blade edge and the smaller indentations are uniformly interspaced between the large indentations.
In another preferred form, the large indentations are of transverse widths greater than the transverse widths of the smaller indentations. In this form the ridges of adhesive made by using the tool not only differ in height but also in width.
In a preferred form the large and smaller indentations are rectilinear. In this case the ridges formed have substantially a rectilinear cross section. In another preferred form the large and smaller indentations have a curved portion at the innermost edge. This curved portion can be used to form ridges of adhesive with curved tops. This curved top can reduce the tendency of topmost portions of adjacent ridges to bridge and close the intervening space, thereby forming voids free of adhesive adjacent the substrate. Further, the use of a curved top increases the effective pressure applied to the ridge of adhesive since the force of pushing the tile, for example, is spread over a reduced area of ridge top compared with a flat topped ridge. Consequently the ridges collapse more readily.
According to one preferred form the support means includes a handle for manual manipulation of the tool. It will be appreciated that the invention need not be limited to a trowel used for tiling and that the invention may have more general application for spreading adhesive on substrates. Accordingly, the tool may be a substantially planar blade or the blade may be part of a machine and so not manually manipulated in use.
The invention may alternatively be said to reside, again not necessarily in the broadest or only form, in a method of spreading adhesive over a substrate including the steps of:
applying adhesive to the substrate; and, using a tool including:
a blade supported by support means and, with respect to the substrate, the blade being moveable over the substrate such that a blade edge is slid over the substrate;
the blade edge having a set of spaced large indentations and at least one set of spaced smaller indentations extending into the blade edge, the smaller indentations extending into the blade less than any one of the large indentations and being interspaced between the large indentations;
to spread adhesive over the substrate by sliding the blade edge over the substrate to form large ridges interspaced with smaller ridges of adhesive projecting from the substrate.
REFERENCES:
patent: D. 267281 (1982-12-01), Motti et al.
patent: 5231729 (1993-08-01), Rose
patent: 2115287 (1971-11-01), None
patent: 3543-146-A1 (1987-09-01), None
patent: 2 259 938 (1993-03-01), None
Talbot Brian K.
Watts Hoffmann Fisher & Heinke Co LPA
LandOfFree
Adhesive trowel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adhesive trowel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adhesive trowel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2466566