Bolster

Abstract

The present invention provides a long-bladed bolster 1, comprising a substantially planar cutting body 2 having one edge formed as a blade 3 of sufficient length so that the blade 3 is arranged in use to be positioned substantially centrally on a concrete masonry unit (CMU) to enable the block to be divided without the bolster 1 requiring repositioning, the bolster having a striking body on a second long edge of the cutting body opposite to the cutting blade configured to receive repeated blows from a striking implement in use and to transmit these through the cutting body to the blade and the bolster having an integral handle that extends from the cutting body and/or striking body of the bolster substantially centrally along the length of the cutting body 2 and substantially orthogonally to the plane thereof.

Claims

1. A long-bladed bolster, comprising a substantially planar cutting body having a plane and a first long edge formed as a cutting blade of sufficient length such that the blade is arranged in use to be positioned substantially centrally across a concrete masonry unit (CMU) block that it is mounted on top of to enable the CMU block to be divided without the bolster requiring repositioning, wherein the bolster has a striking body on a second long edge of the cutting body opposite to the cutting blade that is adapted to be struck repeatedly by a striking implement and transmits force therefrom through the cutting body to the blade; and the bolster has an integral handle that extends from the bolster at a location part-way along the length of the cutting body, the handle being spaced above the cutting edge and thereby not resting on the CMU block in use, and extending transverse to the plane of the cutting body, the integral handle being rigidly fixed in position on the cutting body and thereby moving with the cutting body when the striking body of the cutting body is struck; wherein the blade is at least 200 mm in length.

2. A long-bladed bolster as claimed in claim 1 wherein the handle extends substantially orthogonally to the plane of the cutting body.

3. A long-bladed bolster as claimed in claim 1, wherein the handle extends from the cutting body at a location that is substantially centrally along the length of the cutting body.

4. A long-bladed bolster as claimed in claim 1, wherein the striking body is a solid flat-topped body that is broader than the cutting body.

5. A long-bladed bolster as claimed in claim 1, wherein the striking body is welded to the second long edge of the cutting body.

6. A long-bladed bolster as claimed in claim 1, wherein the striking body is formed as an integral extension of the cutting body.

7. A long-bladed bolster as claimed in claim 1, wherein the striking body is located substantially centrally on the second long edge of the cutting body.

8. A long-bladed bolster as claimed in claim 1, wherein the handle extends from the cutting body and is configured to be grasped by a user in one hand to position and hold the bolster in position.

9. A long-bladed bolster as claimed in claim 1, wherein the handle comprises an arm having an inner end and an outer end and being connected fixed at the inner end to a major face of the cutting body and having a handle knob configured to fit within a user's hand at the outer end.

10. A long-bladed bolster as claimed in claim 9, wherein the arm of the handle is angled upwards.

11. A long-bladed bolster as claimed in claim 9, wherein the arm of the handle is angled upwards at an angle of greater than 45 degrees to horizontal when the bolster is positioned for use with the cutting blade horizontal.

12. A long-bladed bolster as claimed in claim 9, wherein the arm of the handle is joined to the cutting body at a spacing of greater than 30 mm above the first long cutting edge.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

(1) The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

(2) FIG. 1 shows a perspective exploded view from the front and to one side of the preferred embodiment of the longbladed bolster of the present invention, the bolster comprising a planar cutting body having a blade formed on one edge, a striking plate on the opposed, upper in use, edge, and a handle that extends substantially orthogonally from one major planar face of the cutting body.

(3) FIG. 2 shows a side elevation view of the long-bladed bolster of FIG. 1.

(4) FIG. 3 shows a front elevation view of the long-bladed bolster of FIGS. 1 and 2.

(5) FIG. 4 shows a top plan view of the long-bladed bolster of FIGS. 1 to 3.

(6) FIGS. 5A to 5C show perspective views from the left side and to the right side, and from above, respectively, of the long-bladed bolster in successive steps of use to split a CMU block.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(7) Certain exemplary embodiments of the present invention are described herein and are illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention. Other embodiments of the invention, and certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, combinations, modifications, improvements are within the scope of the present invention.

(8) The preferred embodiment of the bolster of the present invention will now be more particularly described, by way of example, only with reference to the afore-mentioned figures.

(9) As shown in FIGS. 1 to 4, the bolster 1 is a long-bladed bolster that lacks an upright shank unlike conventional bolsters. It comprises a substantially planar cutting body 2 having a first major edge formed as a blade 3. The blade 3 runs the full length of the body 2. The planar body 2 is of sufficient length so that the blade 3 can be positioned substantially centrally on a concrete masonry unit or CMU (that is, spanning the depth of the CMU across the length thereof, with the ends of the body generally equidistant from the sides of the CMU), and will extend most or all of the way to each side of the CMU, or slightly overlap the sides of the CMU. The CMU block can be divided without the bolster 1 requiring repositioning. This allows a user to position the tool where required and then divide the block without the need for repositioning and making multiple end-to-end cuts. Given the standard sizes of CMUs, it is advantageous if the cutting body 2/blade 3 is at least 200 mm in length, and preferably around 230 mm in length. The long length allows the bolster 1 to be used with all standard sizes of CMU, overlapping the sides of the narrower ones.

(10) A striking body 4 is located on the opposite edge of the body 2 to the cutting blade 3, ie at the upper in use edge. To use the bolster, as shown in FIGS. 5A to 5C, the striking body 4 is struck by a hammer/mallet M or similar repeatedly so that the force of these blows is transmitted through the striking body 4 and the cutting body 2 to the blade 3 to cut through the CMU which the blade 3 is located against. The striking body 4 provides a surface onto which the hammer/mallet M can be struck and helps to ensure that striking forces are received and transmitted effectively. The striking body 4 is a solid, short cylindrical body, with a flat top that helps to ensure that striking forces are received and transmitted effectively. In this embodiment, the striking body 4 is welded to the upper edge of the planar cutting body 2. In alternative embodiments, the striking body could be formed as an integral extension of the body. The striking body 4 is located substantially centrally along the top edge of the cutting body 2. This helps to ensure that striking forces are received and transmitted effectively.

(11) The cutting body 2, as best seen in FIGS. 2 and 4, is substantially planar. That is to say that it is a slim plate-like body that may be just a few mm thick (generally up to about 10 mm at most) and may be of uniform thickness or of thickness tapering/narrowing towards the blade 3. It may be wedge-shaped in profile. It serves to cleave the CMU block as the blade passes down into the block. The cutting body 2 is suitably about 70 mm in depth/height from the cutting blade edge 3 to the opposing edge with the striking body 4.

(12) A handle 5 extends from one of the major planar faces of the cutting body 2 substantially centrally along the length of the cutting body 2 for grasping by a user in one hand to position and hold the bolster 1 in position in use. In this embodiment, the handle 5 comprises an arm 6 connected at an inner end to the face of the cutting body 2 and a spherical handle knob 7 configured to fit within a user's hand connected to the outer end.

(13) The arm 6 of handle 5 is bent/cranked into an open S or Z shape (that is, it does not double back on itself) as shown in FIG. 1 so that when connected the handle 5 is angled upwards. This positions the handle knob 7 sufficiently above the surface of the CMU in use to allow a user to keep their hand high clear of the CMU in use, avoiding skinned or bruised knuckles or similar as the hammered bolster 1 cleaves down through the CMU block. The crank of the arm 6 is such that arm 6 presents a low profile at its point of attachment to the cutting body 2 and the steep angle of rise of the arm 6 also helps prevent risk of any impact of the handle arm on the block as it is cleaved. The angle of rise of the arm 6 is preferably greater than 40 degrees and of the order of 50 to 60 degrees from the horizontal plane/plane of the surface of the CMU block being cut into. The arm 6 attachment point to the cutting body 2 is preferably spaced up from the blade edge 3 by a clearance of about 45 mm, eg 40 to 60 mm, to facilitate the cleavage action. The low profile initial part of the arm 6 attached to the cutting body 2 is preferably 25 mm or no more than about 40 mm in length. The height from the bottom crank of arm 6 to top crank of arm 6 is preferably about 60 mm or between 50 mm and 70 mm. The handle grip is preferably about 80 mm in length or between 50 mm and 100 mm.

(14) The invention has been described above by way of example only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention. Firstly it will be understood that any features described in relation to any particular embodiment may be featured in combinations with other embodiments. With respect to the specification therefore, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing is considered as illustrative only of the principles of the invention, with variation and implementation obvious and clear on the basis of either common general knowledge or of expert knowledge in the field concerned. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as set out in the accompanying claims.