GB2261901A - Method and apparatus for removing grout and mortar - Google Patents

Abstract

A method of removing grout or mortar filling from the joints between wall and floor cladding elements in which a narrow blade is vibrated at ultrasonic frequencies. The vibrating blade has a large transverse component of displacement which causes the filling material to break up and be dispelled from the joint. An apparatus for carrying out the method comprises a piezoceramic transducer to generate vibrations, a blade having a greater hardness than the filling material and a means to convey ultrasonic energy to the blade. <IMAGE>

Description

method and Apparatus for removing Grout and Mortar.

It is the normal practice in the building trade, when cladding a floor or wall with tile or brick products, to consolidate the resulting gaps between adjacent units of cladding material with a grout of mortar.

plaster or epoxy resin compound. This mav be applied with either brush cr trowel, or it may be poured if the fluidity permits.

.4 wide range of materials are used for this purpose covering gypsum hased products of the cement and plaster type, to epoxy based resins for more arduous applications. In all cases the copound is allowed to set an fulfils a dual function of sealing the surface against penetration by fluids and other contaminants and enhan@ing the mechanical strangth the fixing. Grout and mortar infils also fulfil an aesthetic f fun@ti an virtue cf their colour ano in some cases, texture. The properties of su@ materials are dictated by these functions and they share a commen requirement that they adhere firmly to all contacting surfaces of both cladding and substrate and that they are durable within their operating environment.This defines a minimum level of abrasion resistande and hardness.

These properties do, themselves, present a problem when it is requir@@ replace one or more of the cladding units or merely, for aesthetic reasons, to replace the grout or mortar filling.

It is the object of the present invention to provide an improved method of removing these materials quiclil- and easily without damaging ti surrounding cladding units.

According to one aspect of the present inventicn there is provider a method of applying ultrasonic vibrations via a specially designed hardened tip so as to break up the hard filler into particulate form the product of this action being in the form of a plume of powder which is expelled from the joint a distance of a few centimetres. In the case of epoxy resin the ultrasonic energy degenerates to heat which is preferentially absorbed by the resin causing it to soften sufficiently to be easily removed by simple manipulation of the ultrasonic tool.

According to another aspect of the present invention there is provided an apparatus for carrying out said method described above, which apparatus comprises a hard tip extension, a piezo electri ceramic transducer.

tuned mechanical transformer and high frequency electrical power source.

Ai embodiment of the invention will now be described by way of example and with reference to the following figures:- Figure 1. Shows the removal of grout between t cladnD units.

Figure 2. Schematic illustration of ultrasonic system.

In Fig. 1 the vibrating tip 11 is inserted between cladding elements 13 in order to remove infill 12 thus revealing clear groove 14.

The action of the activated tip depends critically on generatin. a substantially transverse vibrational mode in the tip. This is achieves using the system shown schematically by way of example in fi.2. IZT transducer 2, energises tip 3 via mechanical transformer 1. Said tip, made of hardened steel or tungsten carbide, is held firmly in place by cap 4 attached by threaded connection 8 to the output end of horn 1.

said cap exerts pressure on tip 3, at conical shoulder 6, thereby pushing said tip into conical seating 5 in said horn. Included angle 9 a+ rest of tip 3 is preferably between 60:and 90: to ensure an adequate transverse component 10, of the displacement amplitude defined in vector diagram 7.

The large transverse amplitude in tip 3 ensures maximum dispersal of the grout infill so that the tip clears a groove twice its width when applied to plaster and cement grouts.

According to another aspect of the invention, when used with epoxy grout the high energ- transfer from tip to filler rapidly causes bream up by thermal degradation of the epoxy and mechanical displacement as ne Eit is impelled manually through the weakened infill material.

For convenience, the de-grouting head may be mounted in a pistol shaped handle with integral trigger switch.

Claims (9)

1. A method of removing grout from between wall and floor facing units, the method comprising applying to the joint a thin blade, applying high frequency vibrations in a substantially transverse direction whilst moving the blade along the joint in order to break up and displace the filling material.

2. A method as claimed in claim 1 wherein the vibrations applied to the blade are of a frequency in the region 20-50kHz.

3. A method as claimed in claim 2 wherein the blade is encouraged to vibrate with a high tranverse amplitude.

4. A method as claimed in the preceding claims wherein the high frequency vibrations applied to the blade are derived from ultrasonic vibration of a piezoceramic transducer.

5. An apparatus for removing grout said apparatus comprising a piezoceramic transducer to generate ultrasonic vibrations, a blade of material harder than the grout filling and means to convey ultrasonic vibrations to the blade.

6. An apparatus as described in claim 5 wherein the means to convey said vibrations to the blade is a tuned horn.

7. An apparatus as claimed in claim 6 wherein the blade has a frustum input end which contacts said horn in socket having a tapered surface of identical angle to that of said frustum.

8. An apparatus wherein apex angle of said frustum lies between 60 and 90 degrees.

9. An apparatus as claimed in claim 7 wherein said blade is pressed firmly into contact with said socket by a threaded cap which engages with said horn.