GB2300446A

GB2300446A - Mortar removal tool

Info

Publication number: GB2300446A
Application number: GB9512989A
Authority: GB
Inventors: Roy Feseto
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-05-02
Filing date: 1995-06-26
Publication date: 1996-11-06
Also published as: GB9512989D0; GB9508905D0

Abstract

A tool for and a method of displacing jointing material between building members, for example bricks or blockwork is disclosed, the tool comprising an elongate circularly cylindrical hardened steel body having a shank portion 4 and a cutting portion 6. The tool is arranged to be inserted between building members and driven by a drive member in order to remove material.

Description

TOOL AND METHOD OF USING SANE This invention relates to a tool and a method of using the same and particularly, although not exclusively, relates to a tool for and a method of displacing jointing material between building members, for example bricks or blockwork.

Bricks and blockwork of buildings are secured together by means of mortar joints using mortar which is a mixture of sand, cement and water. Over a period of time, portions of mortar joints may disintegrate or become dislodged and consequently need replacing, in a process known as repointing, in order to maintain the integrity of the building. In repointing, defective mortar must be removed from the mortar joint and one known method of undertaking this comprises using a cutting wheel having abrasive outer edges in combination with a mini angle grinder to cut the defective material out of the joint.

This method produces large amounts of dust and, furthermore, the depth of cut into the mortar joint cannot readily be controlled and, consequently, too little or too much mortar may be removed from the joint.

From time to time, it is necessary to remove selected bricks or blocks from brick/blockwork structures. A known method of undertaking this task uses a hammer and chisel or the cutting wheel and angle grinder as described above.

Use of a hammer and chisel may result in unnecessary stresses being applied to the brick/block being removed or surrounding bricks/blockwork and, furthermore, the method is time-consuming and generates large amounts of dust. Use of a cutting wheel and angle grinder has the same problems discussed above with reference to repointing.

It is an object of the present invention to address the abovementioned problems.

According to the invention, there is provided a tool for displacing jointing material between building members, the tool being arranged to be rotated about a rotational axis and having a cutting surface which faces outwardly in a direction lateral to said axis and is arranged to cut material disposed laterally to said axis.

The tool is preferably for displacing mortar between building members, for example in the form of bricks or blocks. The building members may be spaced apart by a distance of less than 5 cm, preferably less than 2 cm and more preferably less than 1.5 cm. In many cases, the building members are spaced apart by about 1 cm.

The tool is preferably arranged to push jointing material away from it in use.

The tool is preferably arranged to be releasably secured in a chuck of a drive means. The drive means is preferably electrically powered. The drive means is preferably arranged to rotate the tool at greater than 5000 r.p.m. and, more preferably at greater than 8000 r.p.m. Most preferably, the drive means is arranged to rotate the tool at a speed in the range 10,000 to 12,500 r.p.m.

The tool preferably comprises a shank portion and a cutting portion. The cutting portion preferably includes a surface coating. The cutting portion preferably comprises a multiplicity of cutting elements, for example of an abrasive material. The surface density of the cutting elements about at least a part of the cutting portion is preferably substantially constant. Preferably, the surface density of the cutting elements about substantially the whole of the cutting portion is preferably substantially constant.

Preferably, the cutting portion has a circular crosssection. In one embodiment, the cross-section of the cutting portion may be generally constant along the majority, preferably substantially all of its length. In another embodiment, the cutting portion may taper.

Preferably, the cutting portion tapers inwardly on moving away from the shank portion of the tool. The cutting portion is preferably frusto-conical. The cutting portion is preferably arranged (for example by said frusto-conical shape) so that the distance it can penetrate a mortar joint is limited. The cutting portion is preferably arranged so that the distance it can penetrate a joint is arranged to be limited in dependence upon the width of a mortar joint being penetrated in use. Preferably, the arrangement is such that the distance the cutting portion can penetrate a joint is greater than the width of the mortar joint, suitably by a factor of 1.5, preferably by a factor of 1.75 and, more preferably, by a factor of about 2.

The tool is preferably arranged to displace jointing material by an abrasive action. The tool is preferably arranged to exert an abrasive force in a direction lateral to the rotational axis thereof.

The tool preferably has a diameter in the range 4 mm to 20 mm, more preferably, in the range 4 mm to 15 mm.

Where the tool comprises a shank portion and a cutting portion, the diameter of the shank portion is preferably less than that of the cutting portion.

The tool preferably has a length in the range 30 mm to 500 mm. The tool may be used for removing defective mortar prior to repointing and, in this case, the length of the tool is preferably in the range 20 mm to 100 mm, more preferably in the range 30 mm to 75 mm.

Alternatively, the tool may be used for aiding the removal of a brick or block, in which case, the length may be in the range 50 mm to 500 mm.

The tool may be used to cut through brick or blockwork, for example bricks or blocks made out of relatively soft materials such as clay. Such bricks are often used to face buildings.

The invention extends to a method of displacing jointing material between building members, the method comprising contacting a rotating tool having a cutting surface which faces in a direction lateral to the rotational axis thereof with the jointing material such that the cutting surface is surrounded by jointing material and moving the tool laterally to said rotational axis in order to cut into jointing material.

The method preferably uses a tool as described in any statement herein.

The method may be used for displacing and/or removing jointing material, for example mortar from between bricks or blocks prior to repointing; or for displacing jointing material around a brick or block such that said brick or block can be removed from its position. The method may comprise urging the tool into the joint to substantially the maximum depth possible. When so disposed, the depth of penetration of the tool into the joint may be at least 1.5 times, preferably at least 1.75 times and, more preferably about 2 times, the width of the joint. Preferably, in the method, the tool is rotated at a speed of greater than 5,000 r.p.m. and is preferably greater than 8,000 r.p.m.

Specific embodiments of the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows a tool for use in the present invention; Figure 2 illustrates how a brick may be removed from a brick assembly using the tool; and Figure 3 is a cross-section through another tool.

The tool 2 comprises an elongate circularly cylindrical hardened steel body having a shank portion 4 and a cutting portion 6.

The length of the shank portion 4 is suitably about 25 mm and that of the cutting portion 6 in the range 25 mm to 360 mm. The diameter of the shank portion is suitably about 6 mm and that of the cutting portion about 10 mm.

The cutting portion 6 includes an abrasive coating, which comprises abrasive elements 8 around its entire outer surface. The abrasive coating may be selected from diamond, cubic boron nitride, bauxite and tungsten carbide coatings which may be attached to the body of the tool 2 using an appropriate method, for example heat bonding or electroplating.

The tool 2 is arranged to be releasably secured in a chuck of a drive means which is arranged to rotate the tool at a speed in the range 10,000 to 12,500 r.p.m.

A tool 2 may be used for removing defective mortar from mortar joints prior to repointing. In this respect, the tool used is suitably relatively short in length. For example, the length of both the shank portion and the cutting portion may be about 25 mm. The length of the cutting portion may be selected as appropriate to define the depth of cut to be made using the tool.

With the tool secured, via shank 4, in the chuck of the drive means and with the drive means rotating at a speed in the range 10,000 to 12,500 r.p.m., the cutting portion of the tool is inserted into the defective mortar and manipulated to move the cutting portion along the joint so that the cutting portion cuts mortar out of the joint by an abrasive action. Since, in this case, the cutting portion has a length of only 25 mm, the maximum depth of cut of the tool is 25 mm. Consequently, a clean and precise cut may be formed in the mortar joint using the tool. It is also found that a relatively small amount of airborne dust is produced using the tool.

A tool 2 may also be used for removing a brick 20 from a brick assembly 22 as shown in figure 2. In this event, the length of the shank portion 4 of the tool may be about 25 mm as before, but the length of the cutting portion is selected to be approximately equal to the depth of the brick to be removed. Initially a pilot hole may be drilled in the mortar around the brick to be removed. Then with the tool secured in the drive means, the cutting portion of the tool may be inserted into the pilot hole or, if no pilot hole has been drilled, the tip of the tool gradually worked into the joint to its full depth. In some embodiments the tip of the cutting portion may be adapted to penetrate the mortar, for example by being provided with a suitably shaped diamond, or other coating.

Once within the mortar joint, the tool is then moved around the brick 20 whilst gradually removing all of the mortar holding the brick in position. Once sufficient mortar has been removed, the brick can easily be removed.

It is found that a brick can easily be removed using the tool 2 with minimum disturbance or stresses being imposed on the surrounding bricks. Furthermore, little airborne dust is produced when using the tool.

A further embodiment of tool for removing defective mortar from mortar joints prior to repointing is shown in figure 3. Referring to the figure, the tool 20 includes a shank portion 22 and cutting portion 24.

The shank portion is circularly cylindrical and has a diameter of about 6 mm and a length of about 25 mm.

The cutting portion is frusto-conical with the larger end of the cone being adjacent the shank portion 22. The maximum diameter of the cone (distance x) is suitably about 15 mm and the minimum diameter (distance y) is suitably about 6 mm. The length (1) of the cone is suitably about 30 mm. It should be noted that the diameter of the cone at any point is approximately equal to half the distance from the point to free end 26 of the cone.

Thus, the diameter at point 28 is about 10 mm and the distance of the point from free end 26 is about 20 mm.

The cutting portion is provided with an abrasive coating around its entire outer surface, the coating being of the type described above.

In use, the tool 20 is inserted into a chuck of a drive means. Preferred drive means are capable of driving the tool at 10,000 to 12,5000 r.p.m. The tool may be used to remove defecting mortar from mortar joints having a width in the range 6 mm to 15 mm. If it is desired to repoint a joint of, for example 10 mm in width, the cutting portion is gradually pushed into the joint until it has penetrated the joint by a distance of 20 mm. The cutting portion cannot penetrate further than 20 mm into the joint since the diameter of the cutting portion 20 mm from free end 26 is 10 mm, which is the width of the joint. Thus, the shape of the cutting portion serves to limit the depth to which the cutting portion may penetrate in dependence upon the width of the joint.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMB

1. A tool for displacing jointing material between building members, the tool being arranged to be rotated about a rotational axis and having a cutting surface which faces outwardly in a direction lateral to said axis and is arranged to cut material disposed laterally to said axis.

2. A tool according to Claim 1, for displacing mortar between building members.

3. A tool according to Claim 1 or Claim 2, arranged to push jointing material away from it in use.

4. A tool according to any preceding claim, including a shank portion and a cutting portion, the cutting portion including a surface coating.

5. A tool according to Claim 4, wherein the cutting portion comprises a multiplicity of cutting elements.

6. A tool according to Claim 4 or Claim 5, wherein the cutting portion has a circular cross-section.

7. A tool according to any of Claims 4 to 6, wherein the cross-section of the cutting portion is generally constant along the majority of its length.

8. A tool according to any of Claims 4 to 6, wherein the cutting portion tapers.

9. A tool according to Claim 8, wherein the cutting portion tapers inwardly on moving away from the shank portion of the tool.

10. A tool according to Claim 6, 8 or 9, wherein the cutting portion is frusto-conical.

11. A tool according to Claim 6 or any of Claims 8 to 10, wherein the cutting portion is arranged so that the distance it can penetrate a joint, in use, is limited in dependence upon the width of a mortar joint being penetrated.

12. A tool according to Claim 11, the arrangement being such that the distance the cutting portion can penetrate a joint in use is greater than the width of the joint.

13. A tool according to any preceding claim, arranged to displace jointing material by an abrasive action.

14. A tool according to any preceding claim, having a diameter in the range 4 mm to 20 mm.

15. A tool according to any preceding claim, having a length in the range 30 mm to 500 mm.

16. A method of displacing jointing material between building members, the method comprising contacting a rotating tool having a cutting surface which faces in a direction lateral to the rotational axis thereof with the jointing material such that the cutting surface is surrounded by jointing material and moving the tool laterally to said rotational axis in order to cut into jointing material.

17. A method according to Claim 16, using a tool according to any of Claims 1 to 15.

18. A method according to Claim 16 or Claim 17, used for displacing and/or removing jointing material prior to repointing.

19. A method according to Claim 16 or Claim 17, for displacing jointing material around a brick or block such that said brick or block can be removed from its position.

20. A method according to any of Claims 16 to 19, wherein the tool is rotated at a speed of greater than 5,000 r.p.m.

21. A method according to any of Claims 16 to 20, wherein the tool is rotated at a speed of greater than 8,000 r.p.m.

22. A tool substantially as hereinbefore described with reference to the accompanying diagrammatic drawings.

23. A method substantially as hereinbefore described with reference to the accompanying diagrammatic drawings.