GB2540140A

GB2540140A - A trowel

Info

Publication number: GB2540140A
Application number: GB1511771.6A
Authority: GB
Inventors: Bracey Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-07-06
Filing date: 2015-07-06
Publication date: 2017-01-11
Anticipated expiration: 2035-07-06
Also published as: GB2540140B; GB201511771D0

Abstract

The trowel has slurry inlet 2, a base 3 with at least one outlet (fig 2, 13) and a dispersing element 4 to ensure an even flow of plaster is discharged. The dispersing element may be housed in a chamber 5, from which it can be removed for cleaning, and may be made from mesh, solid foam or a manifold. The outlet may be a slit or perforations in the base and the flow of mortar may be controlled by a trigger 8-11 and valve 6, which controls the pressure of a pump (fig 4,19) supplying slurry from a source (fig 4, 18). A method of use is also detailed.

Description

A TROWEL

Field of the Invention

The invention relates to a trowel for applying a slurry, particularly a building surface material such as plaster, to a surface.

Background

Applying a slurry, such as plaster, to a wall or ceiling can be a laborious and time consuming process. Typically, a plasterer must scoop plaster onto a hawk, transfer the plaster from the hawk to a plastering trowel, and then use the plastering trowel to apply the plaster to the surface. Only a small amount of plaster can be carried on the hawk, so this process must be repeated many times. For a medium-sized wall, for example, this process may need to be repeated over 30 times just to apply the first coat of plaster to the wall, with multiple coats generally being required.

Moreover, there is an inherent time limit for applying the plaster to the wall - a coat must be applied before the plaster has dried. The arduous process of plastering must therefore be completed very quickly. This may be particularly difficult to achieve, for example, if the plasterer must climb a ladder to reach the surface being plastered, and climb back down the ladder to reach the source of plaster. Moreover, ladders pose a particular danger to plasterers, as a plasterer holding a hawk and a trowel does not have a free hand to hold onto the ladder with. To overcome this danger, instead of using a ladder, a scaffold typically must be erected, thereby improving safety but making plastering more costly and/or time consuming.

Solutions to the problems of conventional plastering have been proposed. Methods of and apparatuses for pumping plaster to a trowel are known, as described for example in US3403960 and DE10358516. These methods remove the need for a hawk, instead supplying the plaster directly to the working side of the trowel.

Although such methods and apparatuses have the potential to ease the workload of a plasterer, they are generally not used by plasterers. A particular problem is that the plaster delivered to the working side of the trowel is not easily worked, limiting the usefulness of these methods and these apparatuses.

Summary of the Invention

In accordance with the invention there is provided a trowel for applying a slurry to a surface, the trowel comprising a slurry inlet for receiving a flow of slurry, a base comprising at least one slurry outlet, the slurry outlet(s) being in fluid communication with the slurry inlet, and a slurry dispersing element located between the slurry inlet and the slurry outlet, the slurry dispersing element being configured, in use, to disperse the flow of slurry.

The trowel may further comprise a dispersing chamber, wherein the dispersing chamber houses the slurry dispersing element

By using a dispersing element, in use, the flow of slurry may be controlled such that the flow of slurry may be delivered to the slurry outlet(s) in a desired manner to facilitate application of the slurry to the surface, e.g. by spreading the flow of slurry across the slurry outlet(s). In an embodiment, the dispersing element may act, in use, to spread the flow of slurry substantially evenly across the slurry outlet(s). A further advantage it that, by spreading the flow of slurry, the pressure of the flow of slurry exiting the slurry outlet(s) may be reduced. Hence, portions of slurry of the correct shape, quantity and consistency may be applied to a surface from the slurry outlet, and spread across the surface using the base of the trowel. A trowel according to this invention may therefore provide a slurry such as plaster to the working side of the base that is easily worked, overcoming the problems associated with previous trowels, and reducing the time and effort required to cover a surface with the slurry.

The dispersing element may comprise a plurality of pores. For example, the dispersing element may comprise a manifold, a mesh or a solid foam.

The size and/or shape of the pores may be uniform or may vary. For instance, the pores may be up to or at least 0.5mm across up to or at least 1mm across, up to or at least 2mm across, up to or at least 3mm across, up to or at least 4mm across, up to or at least 5mm across, up to or at least 6mm across, and/or up to or at least 10mm across. For instance, the dispersing element may comprise a mesh having holes of a uniform size and/or shape. Alternatively, the size and/or shape of the holes may vary across the mesh. By varying the size and/or shape of the pores within the dispersing element, further control over the flow of slurry to the slurry outlet(s) may be provided.

In an embodiment, the slurry outlet(s) may have a larger overall cross-section than the slurry inlet.

The slurry outlet may comprise one or more openings in the base. In some embodiments, the slurry outlet(s) may comprise at least one slit, e.g. a longitudinal slit, in the base. For example, the or each slit may be up to or at least 2mm wide, up to or at least 3mm wide, up to or at least 6mm wide, and/or up to or at least 10mm wide.

In an embodiment, the slurry outlet(s) may comprise a longitudinal slit, which extends in a lengthwise direction within the base. The longitudinal slit may extend in the lengthwise direction across 50% or more of the length of the base, e.g. across 70% or more, 80% or more or 90% or more of the length of the base. Such a slurry outlet may provide a portion of slurry to a surface that is substantially the same length as the base of the trowel. This may maximise the length of surface that may be covered with slurry in a single sweep of the trowel across the surface.

In an embodiment, the slurry outlet(s) may comprise a perforated sheet.

In some embodiments of the trowel, the dispersing element may be configured to be removable. For example, in embodiments wherein the dispersing element is housed within a dispersing chamber, the dispersing chamber may comprise at least one removable end cap. Once the end cap has been removed, the dispersing element may be slid out of the dispersing chamber.

The provision of a removable dispersing element may be advantageous, since it may enable easier cleaning of the dispersing element. Additionally or alternatively, the dispersing element may be easily removed and replaced with another dispersing element, e.g. a newer or clean dispersing element and/or a dispersing element having a different configuration, e.g. different pore sizes and/or shapes.

In an embodiment, the base may comprise a sheet or plate of metal such as a steel, stainless steel or aluminium. The sheet or plate may have a thickness of up to or at least 0.5mm, up to or at least 1mm, up to or at least 2mm, or up to or at least 5mm.

In some embodiments, the trowel may further comprise a trigger operable to control the flow of slurry. By using such a trigger, the flow of slurry may be easily controlled by the operator whilst applying the slurry to a surface.

The trigger may be located upstream or downstream of the slurry inlet.

For example, in some embodiments the trigger may comprise a block in the flow of slurry, the block being configured to be removable from the flow of slurry when the trigger is operated. The trigger may further comprise a lever connected to the block. By operating the lever, the operator may easily remove the block from the flow of slurry, allowing the slurry to flow through the slurry outlet(s).

In a preferred embodiment, the trowel may further comprise a handle. Conveniently, the lever of the trigger may be being connected to the handle. The operator of such a trowel may then be able to hold the trowel and operate the trigger using only one hand. This may allow the trowel to be operated substantially with one hand, freeing the operator’s other hand to, for example, hold on to a ladder. Therefore by using such a trowel a ladder may be safely used during plastering, eliminating the need to construct scaffolding.

In some embodiments, the trowel may further comprise a valve operable to control the flow of slurry. The valve may allow the pressure of the flow of slurry passing through the trowel to be increased or decreased, or to be stopped altogether. The valve may act as an isolation valve.

In some embodiments, the slurry inlet may be adapted to receive the flow of slurry at pressures of at least 1 bar and/or up to 5 bar.

The slurry may be, for example, a plaster or a mortar.

According to a second aspect of the invention there is provided a pump for supplying a slurry to a trowel according to the first aspect of the invention, the pump comprising a slurry input, a motor, optional pump gears, and a slurry output. The pump gears may be configured to limit the stress applied to the motor when pumping a viscous slurry.

The pump may further comprise a regulator valve and/or a non-return valve attached to the slurry input.

According to a third aspect of the invention there is provided a system comprising a trowel according to the first aspect of the invention, and a pump for supplying a slurry to the trowel. The system may further comprise a source of the slurry.

In an embodiment, the pump may comprise a slurry input, a motor, optional pump gears, and a slurry output.

According to a fourth aspect of the invention there is provided a method of applying a slurry to a surface, the method comprising: providing a source of a slurry; providing a trowel for applying a slurry, the trowel comprising a slurry inlet for receiving a flow of slurry, a base comprising at least one slurry outlet, the slurry outlet(s) being in fluid communication with the slurry inlet, and slurry dispersing element located between the slurry inlet and the slurry outlet, the dispersing element configured in use to disperse the flow of slurry; connecting a pump to the source of the slurry, and to the trowel, so that the slurry is pumped to the slurry inlet of the trowel; spreading the slurry on the surface using the base of the trowel.

In some embodiments, the trowel may further comprise a trigger, and the method may further comprise the step of engaging the trigger. Additionally, the trowel may further comprise an isolation valve, and the method may further comprise the step of opening the isolation valve. In some embodiments, the method may further comprise the step of adjusting the isolation valve to control the pressure of the flow of the slurry.

The method may further comprise the step of cleaning the trowel by flushing the trowel with a cleaning fluid such as water. In some embodiments, the method may further comprise the step of removing the dispersing element from the trowel, and cleaning the dispersing element, e.g. with a cleaning fluid such as water. These steps allow the trowel and dispersing element to be easily cleaned, preventing any build of slurry within the trowel. In some embodiments, after the trowel has been used several times, the dispersing element may become clogged with slurry, and the method may further comprise removing the dispersing element from the trowel, and replacing the dispersing element with a new dispersing element.

In some embodiments, the trowel may further comprise a dispersing chamber that houses the dispersing element, the dispersing chamber comprising at least one removable end cap. The step of removing the dispersing element may comprise removing at least one end cap from the dispersing chamber, and sliding the dispersing element out of the dispersing chamber.

The slurry may be a building surface material such as a plaster (e.g. a backing plaster or a finishing plaster) or a mortar.

Typically, the surface may comprise an internal or external surface of a building, e.g. a wall, a floor, a ceiling or a roof.

Detailed Description

The invention is described in further detail below by way of example and with reference to the accompanying drawings, in which: figure 1 is a schematic representation of an exemplary embodiment of a trowel according to the invention; figure 2 is a schematic representation of the working side of the base of the trowel shown in figure 1; figure 3 is a schematic representation of the trowel during removal of the dispersing element; and figure 4 is a schematic representation of a system for supplying slurry to a trowel according to the invention.

Figure 1 shows an exemplary embodiment of a trowel 1 according to the invention. Trowel 1 comprises a slurry inlet 2 adapted to receive a slurry, such as a plaster or a mortar, and base 3. Base 3 comprises a slurry outlet 13 (shown in figure 2), which is in fluid communication with the slurry inlet 2. The base 3 substantially comprises a thin, flat sheet of material, such as a metal, which can be used to spread the slurry across a surface. For example, base 3 may be a 0.7mmthick sheet of metal such as stainless steel. Base 3 may substantially be a conventional blade of a plastering trowel, adapted to include a slurry outlet 13. In the example embodiment shown in Figure 1, the slurry outlet 13 comprises a 5mm-wide longitudinal slit, which extends to almost the full length of the base 3. This arrangement allows for plaster to be spread out evenly when being applied to a surface. A slurry dispersing element 4 is located between the slurry inlet 2 and base 3. In the illustrated embodiment, dispersing element 4 is housed in a dispersing chamber 5. In other embodiments, however, the dispersing element may be otherwise located between the slurry inlet and slurry outlet, for example the dispersing element may be fastened to the base by means of clips.

Dispersing element 4 may comprise a plurality of pores, through which a slurry may flow. For example, dispersing element 4 may comprise a manifold, a mesh or a solid foam, suitable for dispersing slurry across the length of base 3. In a preferred embodiment, dispersing element 4 is a mesh filter, for example a stainless steel mesh filter.

In use, a slurry flows from slurry inlet 2 through trowel 1, in the direction of the slurry outlet 13. The slurry is received at a first surface of the dispersing element 4. The arrows on figure 1 show the direction of the flow of slurry. Dispersing element 4 disperses the slurry such that the flow of slurry spreads out across the dispersing element. The slurry is forced through the dispersing element 4 by the pressure of the flow of slurry, and exits from a second surface of dispersing element 4, which is adjacent to the slurry outlet 13 in base 3. Dispersing element 4 thus spreads slurry along substantially the whole length of base 3.

Trowel 1 further comprises a valve 6. Valve 6 may be operable to control the flow of slurry through trowel 1. For example, valve 6 may be operable to increase or decrease the pressure of the flow of slurry in trowel 1, or block the flow completely. Valve 6 may act as a fail-safe shut off valve. In the illustrated embodiment, valve 6 is adjacent to, and downstream of, the slurry inlet 2. A connecting tube 7 connects valve 6 to a trigger 8. Trigger 8 may be used to control the flow of slurry. For example, in use, valve 6 is opened to allow flow of slurry into the trowel 1, but trigger 8 substantially stops the flow of slurry, until trigger 8 is engaged and the slurry is allowed to flow.

An exemplary embodiment of a trigger 8 is shown in figure 1. Trigger 8 comprises a block 9, a trigger tube 10, and a lever 11. When trigger 8 is not engaged, block 9 is adjacent to the connecting tube 7, preventing slurry flowing out of connecting tube 7. When trigger 8 is engaged, block 9 is moved out of the path of the slurry, so that trigger tube 10 may receive slurry from connecting tube 7. Slurry may therefore flow through connecting tube 7, trigger tube 10, and into dispersing element 4. In the illustrated embodiment, connecting tube 7 lies substantially parallel to the plane of base 3. Trigger tube 10 redirects the flow of slurry towards the slurry outlet 13 in base 3. For example, trigger tube 10 may redirect the flow of slurry by substantially 90 degrees.

Block 9 is moved by activation of a lever 11. Lever 11 is configured to rest in a position such that block 9 is adjacent to connecting tube 7. For example, lever 11 may be spring biased to rest in such a position. When trigger 8 is engaged by pulling the lever in a direction away from base 3, block 9 is pulled in the same direction, such that trigger tube 10 is in fluid communication with connecting tube 7.

In the illustrated embodiment, trowel 1 comprises a handle 12, which may be used to hold trowel 1, and manoeuvre it across a surface being covered in slurry. Handle 6 may for example be a conventional style handle of a plastering trowel. Lever 11 is adjacent to, and runs substantially parallel to, handle 12. Lever 11 may be attached to handle 12. In this arrangement, an operator may hold trowel 1 and operate lever 11 with a single hand. For example, in use, a user may squeeze lever 11 towards handle 12, and manoeuvre trowel 1 across a surface, constantly applying slurry to the surface whilst spreading the slurry on the surface with the working side of base 3.

Figure 2 shows an underside view of trowel 1, showing the working side of the base 3. Base 3 comprises a slurry outlet 13. In the illustrated embodiment, slurry outlet 13 is a substantially rectangular longitudinal slit in base 3. Slurry outlet 13 may be for example between 2 and 10 mm wide. In preferred embodiments, slurry outlet 13 may be between 3 and 6 mm wide. Slurry outlet 13 may be located substantially centrally on base 3, as in the illustrated embodiment, or may be offset from the centre. For example, slurry outlet 13 may be adjacent to an edge of base 3.

In the illustrated embodiment, slurry outlet 13 runs substantially across the whole length of the base 3. Dispersing element 4 is substantially as long as, or longer than, slurry outlet 13, so that slurry is spread across the whole length of slurry outlet 13.

The substantially rectangular slurry outlet 13 illustrated may have the advantage of providing an appropriately shaped portion of slurry to the underside of trowel 1 for easy working. Such a portion of slurry may be easily spread across a surface, such as a wall, by pressing the trowel 1 against the surface, and sliding the trowel along the surface in a direction that is substantially perpendicular to the length of the slurry outlet 13. Typically trigger 8 is engaged throughout the spreading process, so that slurry is constantly applied to the surface. In this way, the surface may be quickly covered with an evenly spread layer of slurry. Any small irregularities in the slurry applied to the surface, for example overlaps between different sections of applied slurry, may be smoothed out using a conventional trowel, or using trowel 1 with trigger 8 disengaged.

In alternative embodiments, slurry outlet 13 may not be a single rectangular slit. Slurry outlet 13 may comprise a plurality of holes or slits through base 3. For example, slurry outlet 13 may comprise a line of holes in base 3, running substantially along the length of the base 3. In some embodiments, slurry outlet 13 may comprise a perforated sheet, such as a perforated sheet of metal or polymeric material. The design of slurry outlet 13 may be chosen to produce an appropriate shape, quantity and consistency of slurry based on the type of slurry, the surface the slurry is being applied to, and the purpose of the slurry being applied.

After trowel 1 has been used to apply a slurry to a surface, it may be preferable or necessary to clean the dispersing element 4, to prevent slurry drying in the dispersing element 4, which may limit the flow of slurry through the trowel 1 in a future use. In some embodiments, dispersing element 4 may be removable from trowel 1, in order to be cleaned or replaced.

In figure 3, trowel 1 is shown with dispersing element 4 being removed from dispersing chamber 5. In this embodiment, dispersing chamber 5 comprises removable end caps 14a, 14b. In other embodiments, only one of the end surfaces of dispersing chamber 5 may be removable. Alternatively, any other surface of dispersing chamber 5 may be removable, for example side surface 15.

End caps 14a, 14b are removably attached to the dispersing chamber 5 by means of bolts 16a, 16b. Bolts 16a, 16b attach to a rod 17, which passes through the dispersing chamber. In the illustrated embodiment, end caps 14a, 14b, bolts 16a, 16b, and rod 17 are shown as having been removed from dispersing chamber 5. Any other suitable mechanism may be used to removably attach end caps 14a, 14b to dispersing chamber 5.

Once end cap 14a or 14b have been removed, dispersing element 4 may be removed from dispersing chamber 5. For example, in the illustrated embodiment, dispersing element 4 may be slid out of dispersing element 5. Dispersing element 4 may be cleaned, for example by rinsing dispersing element 4 in clean water, and placed back into dispersing chamber 5. Alternatively, it may be necessary to replace dispersing element 4 with a new dispersing element, for example if dispersing element 4 has become blocked with dried slurry, or if a dispersing element with different sized pores is needed for a particular use of trowel 1. A dispersing element with different sized pores may be needed, for example, if trowel 1 is to be used with a more viscous slurry.

Figure 4 shows a system that may be used to deliver slurry to the slurry inlet of a trowel. A source of slurry 18, such as a bucket containing the slurry, is connected to the slurry input of a pump 19 by a pipe 20. In use, a pipe 21 connects the slurry output of the pump 19 to the slurry inlet of a trowel, such as slurry inlet 2 of trowel 1. Pipe 21 is preferably a long, lightweight, and flexible pipe, able to reach the surface to which the slurry is being applied by the trowel, without hindering the movement of the trowel across the surface. A non-return valve 22 in pipe 20 prevents the slurry flowing back from the pump 19 to the slurry source 18. A regulator valve 23 may be placed between pipe 21 and the output of pump 19, to regulate a desired pressure of slurry to the trowel. Typically, the pressure is chosen to be between 1 and 5 bar, e.g. 2 bar or 4 bar, depending on the consistency of the slurry, e.g. plaster.

When switched on, pump 19 moves slurry from source 18 through pipe 21 to a trowel. As the viscosity of a slurry tends to be substantially higher than that of water, pump 19 must be configured to pump high viscosity fluids. For example, pump 19 may contain pump gears, designed to relieve the stress applied to the motor of pump 19 by the slurry.

Once the slurry has been applied to the surface, it may be necessary or desirable to clean the whole system, including the trowel. The slurry source 18 may, for example, be replaced by a source of clean water. With the pump switched on, and valve and trigger of the trowel open, water may flow from the source of water through to the trowel and out of the slurry outlet of the trowel, cleaning the whole system. This cleaning may take place with the dispersing element removed from the trowel, as described above, or in place in the trowel.

Cleaning of the system or dispersing element may take place, as described above, after the application of the slurry to a surface is complete. Alternatively, several coats of slurry may be applied to the surface. Cleaning may then take place whilst waiting for one coat of slurry to dry, before applying a further layer of slurry.

The invention may have utility in applying a slurry, typically a building surface material such as a backing plaster, a finishing plaster or a mortar to an internal or external surface of a building, e.g. a wall, a ceiling, a floor or a roof.

The invention may save users a considerable amount of time and/or labour. Furthermore, safety may be improved, since the invention typically may be operated using one hand, thereby leaving a user with a hand free to hold on to a ladder.

Other embodiments are intentionally within the scope of the invention as defined by the appended claims.

Claims

1. A trowel for applying a slurry to a surface, the trowel comprising: a slurry inlet for receiving a flow of slurry; a base comprising at least one slurry outlet, the slurry outlet(s) being in fluid communication with the slurry inlet; and a slurry dispersing element located between the slurry inlet and the slurry outlet(s), the slurry dispersing element configured, in use, to disperse the flow of slurry.

2. The trowel of claim 1, further comprising a dispersing chamber, wherein the dispersing chamber houses the dispersing element.

3. The trowel of claim 1 or claim 2, wherein the dispersing element comprises a plurality of pores.

4. The trowel of claim 3, wherein the dispersing element comprises a manifold, a mesh or a solid foam.

5. The trowel of any preceding claim, wherein the slurry outlet comprises one or more openings in the base.

6. The trowel of claim 5, wherein the slurry outlet(s) comprise a slit.

7. The trowel of any preceding claim, wherein the slurry outlet comprises a perforated sheet.

8. The trowel of any preceding claim, further comprising a trigger operable to control the flow of slurry.

9. The trowel of any preceding claim, wherein the trowel further comprises a handle.

10. The trowel of any preceding claim, further comprising a valve operable to control the flow of slurry.

11. The trowel of any preceding claim, wherein the trowel is configured such that the dispersing element is removable.

12. A pump for supplying a slurry to a trowel of any of claims 1 to 11, the pump comprising: a slurry input; a motor; optional pump gears; and a slurry output.

13. A system comprising: a trowel according to any of claims 1 to 11; and a pump for supplying a slurry to the trowel.

14. The system of claim 13, further comprising a source of a slurry

15. A method of applying a slurry to a surface, the method comprising: providing a source of a slurry; providing a trowel according to any one of claims 1 to 11; connecting a pump to the source of the slurry, and to the trowel, so that the slurry is pumped to the slurry inlet of the trowel; spreading the slurry on the surface using the base of the trowel.

16. The method of claim 15, wherein the trowel further comprises a trigger, and the method further comprises the step of engaging the trigger.

17. The method of claim 15 or 16, wherein the trowel further comprises an isolation valve, and the method further comprises the step of opening the isolation valve.

18. The method of claim 17, wherein the method further comprises the step of adjusting the isolation valve to control the pressure of the flow of the slurry.

19. The method of any of claims 15 to 18, wherein the method further comprises the step of cleaning the trowel by flushing the trowel with a cleaning fluid.

20. The method of any of claims 15 to 19, wherein the method further comprises the step of removing the dispersing element from the trowel, and cleaning the dispersing element.

21. The method of any of claims 15 to 20, wherein the slurry is a building surface material such as a plaster or a mortar.

22. The method of any one of claims 15 to 21, wherein the surface comprises a wall, a floor, a roof or a ceiling.

23. A trowel for applying a slurry substantially as described herein, with reference to figures 1 to 4.

24. A method of applying a slurry to a surface substantially as described herein, with reference to figures 1 to 4.