WO2018090082A1

WO2018090082A1 - Improved trowel

Info

Publication number: WO2018090082A1
Application number: PCT/AU2017/051248
Authority: WO
Inventors: Geoffrey Willingham
Original assignee: Beargrit Pty Ltd
Priority date: 2016-11-16
Filing date: 2017-11-14
Publication date: 2018-05-24
Also published as: AU2016259334A1; AU2016259334B2

Abstract

A hand tool for applying adhesive to a substrate is provided that is wear-resistant, which in turn can result in a more consistent application of adhesive and reduces the risk of sharp edges being formed, and may key the substrate, as the adhesive is spread, which increase bonding, without requiring any further steps from the user. The hand tool includes: a notched blade configured to distribute adhesive to the substrate; and a wear resistant coating on at least a portion of the blade.

Description

IMPROVED TROWEL

TECHNICAL FIELD

[0001] The present invention relates to an improved hand tool. In particular, although not exclusively, the present invention relates to an improved notch trowel for applying adhesive.

BACKGROUND ART

[0002] Notch trowels are commonly used to apply an even layer of adhesive to walls and flooring when tiling, but are also used for applying adhesive in other contexts, such as when laying vinyl and sheet flooring.

[0003] In use, adhesive is place on the substrate, and the notches of the trowel are pressed against the substrate (e.g. a concrete floor) and moved across the substrate to form even rows of adhesive. The amount of adhesive on the substrate is determined by the size of the notches, and as such, trowels are provided with different sized notches to suit different tasks.

[0004] A problem with notch trowels of the prior art is that they wear quickly, particularly when used on very hard substrates such as concrete. As a result, an amount of adhesive applied reduces as the trowel wears, which can in turn cause uneven application of adhesive, and thus inadequate adhesion and/or cracked tiles.

[0005] A further problem with notch trowels of the prior art is that they can become very sharp as the wear, in many ways resembling a knife blade. This is particularly dangerous when trowels are washed after use, as the sharp edge may be hard to see in murky water.

[0006] Attempts have been made to make wear-resistant notch trowels by using stronger steel in the trowel and by increasing the thickness of the steel used. Such trowels generally have somewhat improved wear resistance, but still have the same problems of trowels described above.

[0007] As such, tilers and other tradespeople must manually monitor their trowels for wear, and replace them as required.

[0008] Accordingly, there is clearly a need for an improved trowel.

[0009] It will be clearly understood that, if a prior art publication is referred to 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 INVENTION

[0010] The present invention is directed to a hand tool, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

[0011] With the foregoing in view, the present invention in one form, resides broadly in a hand tool for applying adhesive to a substrate, the hand tool including:

a notched blade configured to distribute adhesive to the substrate; and

a wear resistant coating on at least a portion of the blade that is configured to prevent wear to the blade from the substrate when adhesive is distributed on the substrate.

[0012] The substrate may comprise concrete.

[0013] Preferably, the hand tool includes a handle, coupled to the notched blade. Suitably, the handle extends upwardly from a central portion of the blade.

[0014] Preferably, the blade is substantially planar.

[0015] Preferably, the blade is substantially rectangular in shape.

[0016] Preferably, at least an elongate side of the rectangular blade is notched.

[0017] Preferably, at least one other side of the rectangular blade is not notched. Suitably, the side of the blade that is not notched also includes a wear resistant coating. The wear resistant coating may be formed on an outer edge of the side of the blade that is not notched.

[0018] Preferably, the notched blade comprises a plurality of notches spaced along a linear edge of the blade. Suitably, the notches are evenly spaced. Suitably, the notches are

symmetrical.

[0019] Preferably, the plurality of notches define teeth on an outer edge of the blade between the notches.

[0020] Preferably, the wear resistant layer is provided on an outer edge of the teeth.

Suitably, the wear resistant layer is provided on less than half of a length of the teeth. Suitably, the wear resistant layer is provided on about an outer third of the teeth.

[0021] Preferably, the notches are rectangular in cross section. The notches may be triangular in cross section. The notches may be square-shaped in cross section. [0022] Preferably, the notches and the teeth are about the same size.

[0023] Preferably, the wear resistant layer is configured to be abrasive on the substrate. Suitably, the wear resistant coating is configured to key the substrate.

[0024] Preferably, the wear resistant layer includes grit that is greater than about 50 micron in diameter. More preferably, the wear resistant layer includes grit that is greater than about 100 micron in diameter. Suitably, the wear resistant layer includes grit that is about 300 micron in diameter.

[0025] Preferably, the grit comprises at least one of diamond, diamond-like carbon, and ceramic.

[0026] Preferably, the wear resistant layer is formed by one of electroplating, vacuum brazing, and sintered metal bonding.

[0027] Suitably, the hand tool comprises a tiling and vinyl trowel.

[0028] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0029] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0030] Various embodiments of the invention will be described with reference to the following drawings, in which:

[0031] Figure 1 illustrates an upper perspective view of a notch trowel, according to an embodiment of the present invention;

[0032] Figure 2 illustrates a top view of the notch trowel of Figure 1;

[0033] Figure 3 illustrates a bottom view of the notch trowel of Figure 1;

[0034] Figure 4 illustrates an enlarged perspective view of a portion of the notch trowel of Figure 1;

[0035] Figure 5 illustrates an enlarged top view of the portion of the notch trowel of Figure [0036] Figure 6 illustrates an enlarged bottom view of the portion of the notch trowel of Figure 4;

[0037] Figure 7 illustrates an even more enlarged side view of a portion of the notch trowel of Figure 1;

[0038] Figure 8 illustrates an enlarged top view of a portion of a notch trowel according to an alternative embodiment of the present invention;

[0039] Figure 9 illustrates an enlarged top view of a portion of a notch trowel according to an alternative embodiment of the present invention; and

[0040] Figure 10 illustrates an enlarged top view of a portion of a notch trowel according to an alternative embodiment of the present invention;

[0041] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way.

DESCRIPTION OF EMBODIMENTS

[0042] Figure 1 illustrates a perspective view of a notch trowel 100, for applying adhesive to a substrate, according to an embodiment of the present invention.

[0043] The notch trowel 100 comprises a body 105 in the form of a blade, which is substantially rectangular and/or square in shape and is planar. The body 105 includes first and second notched faces 105a, and a handle 110 extending upwardly from an upper surface of the body 105.

[0044] As best illustrated in Figure 2, the notched faces 105a comprise a plurality of notches 205, equally spaced along the notched faces 105a, defining a plurality of teeth 210 between the notches 105. The notches 105 and the teeth 110 are approximately equal in size and are substantially rectangular in shape.

[0045] In use, adhesive is placed on substrate, and a notched face 105a of the trowel 100 is pressed against the substrate, and moved across the substrate and adhesive to form even rows of adhesive. As an illustrative example, the substrate may comprise a concrete floor, and the adhesive may comprise tile adhesive, for adhering tiles to the concrete floor.

[0046] As best illustrated in Figures 4, 5 and 6, a wear resistant coating 405 is provided on outer edges of the teeth 210. The wear resistant coating is formed of a material having a higher hardness than the body 105, and protects the body 105 from wear when moved across the substrate.

[0047] The coating 405 is provided on a front side of the body 105, a rear side of the body 105, and on side edges of the teeth 210. As such, even if the trowel 100 is held on an angle when moved across the substrate, the coating 405 will protect the body 105.

[0048] The coating 405 is provided on outer edge of the teeth 210 only, as these are the areas that typically wear most quickly. The wear resistant layer is provided on less than half of a length of the teeth, and in particular on about an outer third of the teeth 210. Such configuration provides a good balance between cost and wear resistance.

[0049] The wear resistant layer 405, in addition to reducing wear of the teeth 210, is configured to be abrasive on the substrate. In some substrates, keying (scratching) the substrate helps adhesion of the adhesive to the substrate. As such, the trowel 100 is particularly advantageous in such scenarios as the adhesive may be spread over the substrate, and the substrate keyed simultaneously.

[0050] The body 105 is preferably formed of sheet metal, such as steel sheet metal, and the coating of diamond, diamond-like carbon, cubic boron nitride or ceramic. Such combination provides a good balance between cost and wear resistance, as a relatively inexpensive material (i.e. steel) forms a majority of the body 105, and relatively expensive materials (e.g. diamond) are only applied to a small portion thereof.

[0051] Figure 7 illustrates an even more enlarged side view of a portion of the notch trowel 100 comprising a tooth 210, illustrating the wear resistant layer 405.

[0052] The wear resistant layer 405 comprises a plurality of wear resistant particles (grit) 705 that are attached to an outer tip 710 of the tooth 210.

[0053] The grit 705 is generally greater than about 50 micron in diameter, and in particular greater than about 100 micron in diameter. The wear resistant layer 405 includes grit 705 that is about 300 micron in diameter.

[0054] By using grit 705 that is greater than about 100 micron in diameter, a rough edge is provided which is particularly suited for keying (scratching) the substrate.

[0055] While the grit 705 is illustrated as being of uniform size, the skilled addressee will readily appreciate that in practice the grit 705 will vary in size. Similarly, the grit 705 may be of any suitable material, including diamond, diamond-like carbon, cubic boron nitride and ceramic.

[0056] Turning back to Figure 1, the trowel 100 includes straight edges 105b, i.e. edges that do not include notches 205/teeth 210. The straight edge 105b can also include the wear resistant layer 405. This is useful for preventing wear to the body 105 when the straight edge 105b is used to scrape excess adhesive from the substrate.

[0057] As will be readily understood by the skilled addressee, the shape and size of teeth 210 and notches 205 define a thickness and shape of the adhesive applied. As such, various sizes and shapes of teeth 210 and notches 205 may be used for various use cases. As shown in Figures 8 and 9, different trowels have different style of notches and teeth.

[0058] Figure 8 illustrates an enlarged top view of a portion of a notch trowel 800 according to an alternative embodiment of the present invention. The notch trowel 800 is similar to the trowel 100, but includes layered teeth.

[0059] In particular, the trowel includes first notches 805 defining first teeth 810. Within the first teeth 810 are second notches 805a defining second teeth 810a.

[0060] Figure 9 illustrates an enlarged top view of a portion of a notch trowel 900 according to an alternative embodiment of the present invention. The notch trowel 900 is similar to the trowel 100, but includes v- shaped teeth 910 and notches 905.

[0061] Figure 10 illustrates an enlarged top view of a portion of a notch trowel according to an alternative embodiment of the present invention. The notch trowel 1000 is similar to the trowel 100, but includes U-shaped notches 1005 between substantially rectangular teeth 1010.

[0062] In one embodiment, the notch trowel is a 1/4" X 3/8" square-notch trowel. In another embodiment, the notch trowel is a 10mm square-notch trowel. In another embodiment, the notch trowel is a 1/4" X 5/16" V-notch trowel.

[0063] The skilled addressee will readily appreciate that a trowel may be initially

manufactured without the wear resistant layer 405, and subsequently modified to include the wear resistant layer. . [0064] In one embodiment, the trowel may be manufactured by forming a blade including a plurality of notches defining a plurality of teeth, masking the blade with the exception of tips of the teeth, and applying the wear resistant layer to the unmasked portions of the blade using electroplating.

[0065] In other embodiments, the trowel may be manufactured by forming a blade including a plurality of notches defining a plurality of teeth, and partially submerging (dipping) ends of the teeth into an electroplating bath to provide a localised wear resistant layer.

[0066] In yet other embodiments, synthetic diamond crystals/particles may be welded to ends of the teeth of the trowel in a vacuum brazing furnace to provide a localised wear resistant layer.

[0067] In yet other embodiments, sintered metal-bonding may be used to form the localised wear resistant layer, where synthetic diamond crystals/particles are combined with metal powder and then sintered to the ends of the teeth.

[0068] In some embodiments, a Cubic Boron Nitride (CBN) coating may be used to form the localised wear resistant layer. One advantage that CBN has over diamond coating, for example, is that it does not chemically wear in the presence of graphite and/or carbide forming elements, like iron, nickel or cobalt, during abrasive processing. The CBN may be provided as grit (relatively large), or fine powder, and as a sintered polycrystalline product.

[0069] However, the skilled addressee will readily appreciate that the above methods may be used with other crystals/particles, and any suitable method of manufacture may be used.

[0070] While the above embodiments illustrate notched edges and straight edges, the skilled addressee will readily appreciate that in some embodiments, all edges of body/blade are notched.

[0071] Similarly any suitable handle configuration may be provided in relation to the blade.

[0072] Advantageously, the wear resistant layer extends the life of trowel, which in turn can result in a more consistent application of adhesive.

[0073] The wear resistant layer keys (scratches/etches) the substrate, as the adhesive is spread, which increase bonding, without requiring any further steps from the user.

[0074] Finally, the wear resistant layer also reduces the risk of sharp edges being formed on the trowel, which improves work safety. [0075] In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0076] 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 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.

[0077] 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 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 (if any)

appropriately interpreted by those skilled in the art.

Claims

1. A hand tool for applying adhesive to a substrate, the hand tool including:

a notched blade configured to distribute adhesive to the substrate; and

a wear resistant coating on at least a portion of the blade that is configured to prevent wear to the blade from the substrate.

2. The hand tool of claim 1, wherein the notched blade comprises a plurality of notches spaced along a linear edge of the blade defining teeth.

3. The hand tool of claim 2, wherein the wear resistant layer is provided on an outer edge of the teeth.

3. The hand tool of claim 2, wherein the wear resistant layer is provided on less than half of a length of the teeth.

4. The hand tool of claim 1, wherein the wear resistant layer is configured to be abrasive on the substrate.

5. The hand tool of claim 1, wherein the wear resistant layer includes grit that is greater than about 100 micron in diameter.

6. The hand tool of claim 1, wherein the substrate comprises concrete.

7. The hand tool of claim 1, wherein the hand tool includes a handle, coupled to the notched blade.

8. The hand tool of claim 7, wherein the handle extends upwardly from a central portion of the blade.

9. The hand tool of claim 1, wherein the blade is substantially planar.

10. The hand tool of claim 1, wherein the blade is substantially rectangular in shape.

11. The hand tool of claim 1, wherein at least an elongate side of the rectangular blade is notched and at least one other side of the rectangular blade is not notched.

12. The hand tool of claim 11, wherein a side of the blade that is not notched also includes a wear resistant coating.

13. The hand tool of claim 1, wherein the notches are evenly spaced.

14. The hand tool of claim 1, wherein the notches are symmetrical.

15. The hand tool of claim 1, wherein the notches are rectangular in shape.

16. The hand tool of claim 1, wherein the notches are triangular in shape.

17. The hand tool of claim 1, wherein the notches are rectangular in cross section.

18. The hand tool of claim 1, wherein the grit comprises at least one of diamond, diamondlike carbon, cubic boron nitride, and ceramic.

19. The hand tool of claim 1, wherein the wear resistant layer is formed by one of electroplating, vacuum brazing, and sintered metal bonding.

20. The hand tool of claim 1, wherein the hand tool comprises a tiling and vinyl trowel.