Patent Application
20110225760
The present invention relates to a novel trowel for use by bricklayers. The trowel comprises a flat blade having a first face and an opposing second face and containing at least one protrusion on one face.
Bricklayer's trowels are used in the building trade for applying and spreading mortar. Such trowels are employed to apply and spread mortar on horizontal layers or courses of bricks before the bricks of the next higher course are laid. The thickness of mortar between courses is regulated by horizontal cords and/or by the skill and experience of the bricklayer. Bricklayers sometimes use trowels for cutting or chopping bricks.
A problem encountered in bricklaying is that there is no straightforward means or method of regulating the amount of mortar in the gap or cross joint between the adjacent vertical faces of adjacent bricks in the same course. As a result, a course of bricks could be longer or shorter than the desired length. The present invention is intended to address this problem.
The present invention provides a bricklayer's trowel having the features recited in claim 1 of the set of claims following this description. Optional and/or preferred features of the trowel are the subject of other claims in the said set of claims.
In accordance with the present invention there is provided a trowel comprised of a substantially flat quadrilateral blade having four corners and having a first face and an opposing second face and having a handle at one corner, the blade having at least one protrusion on one face of the blade in the region of another corner of the blade.
In a preferred embodiment the trowel also contains a handle at one of its corners.
In another preferred embodiment each protrusion is a substantially smoothly curved surface.
The present invention provides a novel bricklayer's trowel capable of better regulation of the gap or cross joint between adjacent vertical faces of adjacent bricks in the same course of bricks. The result being that the resulting course of bricks will be of the desired length compared with use of conventional trowels.
Turning now to the figures hereof, the trowel 10 of
The protrusion 15 may be on a notional line (not shown) joining corners 13 and 14. In some preferred embodiments, protrusion 15 is at a location on blade 11 that is slightly displaced from this notional line so as to be closer to handle 12a. This displacement leaves the adjacent corner 13 substantially unaffected by the presence of protrusion 15 so that it can be employed for cutting bricks in the well-known manner.
Protrusion 15 may be an integral or unitary part of the blade or it may be a separate part which is secured to blade 11 by any suitable means. Thus, protrusion 15 may be a dimple which is integral with blade 11 and formed by pressing or stamping. Alternatively, protrusion 15 may be a separate member secured to the blade, e.g., by spot welding. A suitable separate member (not shown) might be, e.g., a piece of metal resembling the domed head of a dome-headed bolt.
Protrusion 15 is preferably of a substantially smoothly-curved dome-like form and may will preferably have a substantially circular base, as depicted in the figures hereof, since this will be easier to clean than a protrusion having sharp angles. A smoothly-curved domed protrusion can be made by stamping or pressing blade 11. Alternatively, the blade may be formed from suitable sheet metal having a ridged section at or adjacent to the edge of blade 11 which is subjected to a grinding process to form a desired protrusion 15. Another form (not shown) of the protrusion is cylindrical with a flat outer face. This latter form can be made by welding or spot-welding a cylindrical disc (e.g., a stud or boss) to the face of the blade.
Although the present invention is not limited to exact dimensions of instant trowel there are preferred dimensions. For example, it is preferred that the total distance between the free end of the protrusion and the lower or bottom face (as shown) of blade 11 be equal to (or approximately equal to) the desired gap for mortar between adjacent vertical faces of adjacent bricks in the same course. In UK, this distance is typically 10 mm. In USA, this distance is ¼ inch (6.35 cm). Thus for UK use, blade 11 will preferably have a thickness of about 2 mm, protrusion 15 should preferably extend about 8 mm from the surface of the blade 11 from which it protrudes. However, blade 11 may have a thickness in the range of about 1 to 3 mm, and protrusion 15 would then extend a distance in the range of about 9 to 7 mm so that the total thickness of the blade and protrusion will preferably be about 10 mm if the desired gap between adjacent bricks in the same course is about 10 mm.
In use, trowel 10 is employed to apply and spread mortar on bricks. When bricks are being laid, bricks are laid in a bed of mortar to form a horizontal course. As each additional brick is added to the course, mortar is applied by the trowel to the vertical face of the last-laid brick of the course. The corner region 13 of trowel 10 of the present invention is located in the vertical gap between adjacent bricks where it serves as a gauge or spacer, wherein one brick abuts a face of the trowel's blade and the adjacent brick abuts the “top” or free, distal, end of protrusion remote from the main face of blade 11. Thus, the gap or space between adjacent bricks in a course is relatively accurately defined. When adjacent bricks in a course are thus disposed with a gap of the desired size between them, corner region 13 of the trowel is withdrawn from the gap and the gap is filled with mortar to complete the joint. The gaps between bricks in each course can therefore be of substantially uniform dimensions, substantially equal to the thickness of the blade plus the “height” of the protrusion. As a result, each course laid by the method described has substantially the desired length. It has not previously been possible to ensure readily that the gaps or cross-joints between bricks in a course were uniform by use of conventional trowels. The trowel of the present invention enables this difficulty to be surmounted.
The trowel of
At least one protrusion 15, preferably all, are preferably located on blade 11 slightly offset from its respective corner(s) 13 or 14 in a direction towards handle 12a, so that the corner(s) 13, 14 can be used for cutting bricks in the well-known manner. The offset distance from the respective comer(s) will preferably be in the range of about 2 to about 20 mm, e.g. about 3 to about 15 mm, for example about 4 to about 12 mm, suitably about 5 to about 10 mm, so that the corner(s) 13, 14 are available for cutting bricks despite the provision of the protrusion(s) 15.
Features of one embodiment described herein may be employed in any feasible combination with features of another embodiment.
