GB2294766A - Method and apparatus for constructing curvilinear portions of buildings - Google Patents

Abstract

A method and apparatus for forming a curvilinear portion 2 of a building or other structure is disclosed in which a template 4 is used to control the movement of a tool 6 used to construct the structure. The template has a scaled-down profile corresponding to the desired profile of the structure. The tool is mounted on a follower means, such as a rack and pinion 5, which cooperates with the template 4 such that relative movement between the follower means and template causes the tool to move along the desired curvilinear profile. The template 4, follower means 5 and tool 6 may be mounted on a carriage (3) which runs along a track 1. <IMAGE>

Description

Method and apparatus for constructing curvilinear portions of buildings The present invention relates to a method and apparatus for constructing curvilinear portions of buildings, and in particular curvilinear portions constructed using reinforced concrete.

With conventional designs of buildings, and in particular brick-built structures having substantially rectilinear sides, it is a relatively simple matter to draw up instructions for a construction team based on an architect's original design drawings and/or model.

Positions and dimensions can be easily defined once the site has been selected and the rectilinear walls, ceilings, etc., can be quickly constructed.

However, as the design of buildings grows more complex, and in particular begins to employ surfaces which are other than planar, the process of conveying the requirements of the design to the construction team becomes at best a lengthy task. When buildings contain a variety of curvilinear surfaces, possibly in three dimensions, such as those to which this application relates, it can be almost impossible for the construction team to put into practice, with any degree of certainty, what the architect has designed.

One way of overcoming this problem is to preform any complicated or unusual curvilinear sections either adjacent to the building site or off-site altogether. A method of manufacturing such sections is described in the present applicant's prior UK Patent Application No.

9318280.6 in which curvilinear sections are preformed using moulds. Such a system is particularly suitable for constructions using repeated shapes, such as a building having a large number of identical rooms. The design of the curvilinear section formed by this process is, however, limited to the shape of the particular moulds available, and therefore the freedom and adaptability of the design can be restricted. Also, the physical size of the section required may necessitate its formation on-site and in position without being able to preform sections.

These problems might occur, for example, in the construction of interconnecting curvilinear corridors between existing or recently-built structures which might also be of a curvilinear design and may have been formed by the applicant's prior method discussed above.

Another example might be in the construction of individually-designed curvilinear rooms or other features such as balconies, external walls or ceilings.

In one method of fabricating rectilinear or curvilinear structures on site a mesh or network of reinforcing bars is used, which has the general threedimensional shape of the finished structure. The reinforcing bars are usually formed from steel such as high yield steel, also known as rebar. A layer of concrete, which may be a sprayed concrete such as gunite or shotcrete, is applied to the mesh and the surface is finished off. The finishing may be performed by sledging whereby a tool having the required contour of the surface is moved across the concrete while it is still soft. In this way, the finished surface of the concrete has the desired profile and texture.

Such a method of forming reinforced concrete can be used simply and effectively when constructing uncomplicated structures having substantially rectilinear sides. However, when employing this method to build structures having curvilinear portions, several problems can arise.

Firstly, as discussed above, conveying the dimensions and location requirements of the structure to the building team may be a difficult and lengthy process. The positioning of the reinforcing steel bars, which determines the general shape and position of the structure, is important.

More significantly, when finishing off the surface once the concrete has been sprayed on, detailed instructions again need to be given concerning the final shape of the surface. Furthermore, the finishing process is time consuming if done entirely by hand, and problems can arise when internal or concave curves are being finished as it is difficult to judge when the shape is correct.

The applicant has identified a need for greater flexibility when designing and constructing curvilinear structures.

Viewed from a first aspect, the present invention provides a method and apparatus of forming a curvilinear portion of a building or other structure, wherein a template is used in controlling the movement of a tool employed in the construction or finishing of the curvilinear portion such that the tool movement corresponds to a desired shape of the curvilinear portion.

Thus the present invention provides a method of forming a curvilinear portion of a building or other structure, wherein a template profiled to provide a desired shape of the curvilinear portion is used in controlling the movement of a tool employed in the construction or finishing of the curvilinear portion.

The present invention also provides apparatus for constructing a curvilinear portion of a building or other structure, comprising a tool and a template profiled to provide a desired shape of the curvilinear portion, the template being arranged for use in the control of the movement of the tool.

The tool may comprise means for indicating where constructional elements are to be placed, for gripping and locating the constructional elements, for constructing or finishing the surface of the curvilinear portion, or for any other necessary purpose.

The tool may be mounted on a follower means which cooperates with, or is otherwise movable in accordance with the profile of, the template such that relative movement between the follower means and the template causes or enables the follower means to follow the profile of the template and move the tool in the desired manner.

The method and apparatus enable complex curvilinear surfaces and structures to be constructed accurately and efficiently. The shape of the template may simply be obtained from the architect's original design, and the construction team need only be given basic instructions concerning the location and orientation of the template on site. The invention thus provides a simple reference system for accurately controlling the movement of the tools required for construction.

The simplicity of the method makes it inexpensive and fast, and it is possible to provide repeatability of the curvilinear portion while retaining a high degree of flexibility.

The template is preferably a scale replica of the desired curvilinear portion, for example a 1:100 scale replica. A follower means movable in relation to the template would then be configured so that movement of the follower means at the template profile is magnified (for example by 100 times) at the tool.

The apparatus may be fixed at a set position, for example on a tripod or other suitable base. In this case, the template may have a shape which corresponds generally to the shape of the curvilinear portion being constructed relative to that position. For example, if the room is generally circular, the template will be similarly generally circular and mounted with the follower means rotating about it. The follower means could also provide a non-linear relationship between the template and the movement of the tool, in which case the template itself would not necessarily precisely match the finished profile.

Preferably, the apparatus is able to move along a predetermined path such that the shape of the curvilinear portion under construction as produced by the movement of the tool is defined both by the profile of the template and by the predetermined path followed by the apparatus.

The template, follower means and tool may be mounted on a carriage which runs along a track, as described in the Applicant's copending UK Patent Application No. 9407475.4 entitled "Method of constructing curvilinear portions of buildings".

In Application No. 9407475.4, curvilinear portions may be constructed using tools mounted on the carriage and projecting perpendicular to the track. The track is normally laid in sections so as to conform to the shape in plan of the curvilinear portion under construction, such that the tool traces out the curvilinear shape as it moves along the track.

With the present invention, it is not essential for the track to conform to the curvilinear shape, as the template is able to define the entire shape of the curvilinear portion being constructed, and so the track may be laid in a straight line or simple preset curves.

The present invention is therefore able to greatly simplify the construction process, as custom-made or complicated pieces of track are not required.

In the Applicant's copending application, alcoves are formed by mounting the tool on a second arm pivoting about a first arm extending from the carriage. By the present invention, however, an alcove may be easily incorporated into the template profile, without the need for a special tool support for this purpose.

The template may take any suitable form, and in one embodiment is planar in configuration and arranged to define the shape of the curvilinear portion in a horizontal plane only. However, it is possible that the template may be three-dimensional. In this way, it is possible to define the shape of the curvilinear portion in horizontal and vertical cross-section.

For example, when the template is mounted at a fixed position, it may take the form of a profiled sphere or hemisphere with the profile corresponding to the desired three-dimensional shape of the structure relative to the fixed position. When the template is mounted on a carriage, it may take the form of aprofiled cylinder or portion of a cylinder. In this way, the template can serve as a reference system for the entire curvilinear surface and not just the plan configuration.

As a further alternative to the above, it is possible to mount a planar template vertically such that its profile defines only the vertical cross-section of the curvilinear portion.

Where the template is carried on a moving carriage, it preferably takes the form of an elongate element, one edge of which lies generally in the direction of carriage movement and is profiled in accordance with the curvilinear shape. In this case, the follower means moves in and out perpendicular to the edge and carriage movement direction as it follows the profile.

When mounted on the carriage, the template and follower means must move relative to one another in synchronism with the movement of the carriage along the track, so that at any point along the track, the follower means cooperates with the correct part of the template profile to give the correct tool position at that point.

Preferably, therefore, means, such as gearing means, are provided on the carriage which cause the template and follower means to move relative to one another.

The gearing means may take any suitable form and may act on either the template or follower means, or both. Preferably, the gearing means acts on the template, with the follower means fixed relative to the carriage. The gearing means may either be driven from a wheel or axle of the carriage or may be driven directly from the track itself.

The template may be mounted on a rack, or provided with a series of holes, such that a gear of the gearing means may cooperate with the template or rack and cause the template to move with the gear.

If the gearing means is to be driven from a wheel or axle of the carriage, that wheel or axle is preferably provided with a gear mounted on the axle The gearing means may consist of sufficient gears to provide scaled-down motion of the template relative to the carriage, and to cause the template to move in the same or opposite direction to that of the carriage.

If the gearing means is to be driven from the track, independently of the carriage wheels or axles, the track is preferably provided with a rack or similar structure such that a gear of the gearing means may cooperate with this and provide the required motion of the template. Alternatively, the gearing means could include its own wheel which cooperates with the track and provides motion to the template.

Instead of gearing means, the template and follower means could be moved relative to one another by an electric motor.

It should be noted that, depending on the configuration of the gearing means, the template may move relative to the carriage in the same direction as the carriage is moving along the track, or in the opposite direction. When the template moves in the opposite direction to the carriage, the template should be the same shape in plan as the curvilinear portion being constructed. However, when the template moves in the same direction as the carriage, the shape of the template in plan will need to be rotated through 1800 (i.e. turned over) in order that the tool end of the follower means will still trace out the correct shape.

Although preferably elongate, the template may take on different configurations. For example, it may take the form of a disc or a portion of a disc, rotating horizontally relative to the carriage as the carriage is moved along the track. In this case, the follower means would cooperate with the outer profiled edge of the disc.

The follower means may take many different forms.

One preferred form is a simple pantograph arrangement, which may be made from four rods forming a parallelogram with two of the rods, which are connected to one another, extending beyond the parallelogram such that the follower means has an overall triangular shape. As is known, if the pantograph is fixed but free to rotate about one point on one of the extended rods, movement of a second point on one of the short rods will produce a similar but scaled-up movement of a third point on the other of the extended rods. In the present method, the second point is made to follow the profile of the template and the tool is carried at or is moved by the third point.

The positions of the fixed point of the pantograph, the point cooperating with the template, and the point at which the tool is carried may all be adjusted so as to adjust the overall magnification effect of the pantograph.

A second form of follower means comprises a lever system. In its simplest form, this comprises a single lever which is fixed such that it can rotate about a point in the same plane as the template. As one end of the lever moves in accordance with the template profile, the other end is caused to move in a corresponding manner, but in an opposite direction. Therefore, this system would require a 'negative' type template, i.e. a mirror image of the curvilinear portion under construction (the pantograph arrangement described above would use a 'positive' type template in which the profile of the template is simply a scaled-down version of the curvilinear portion).

By placing the fixed point of the lever closer to the template end, the magnification of the template movement at the tool end may be increased.

In a more robust form, the lever system could comprise, for example, three levers with the centre one being fixed at a point. The ends of the levers would be fixed together, and would therefore always remain in line.

Two or more lever systems may be used which cooperate with one another. If two lever systems are used, a 'positive' type template could be employed. One end of the first system would cooperate with the template, and the other end would cooperate with one end of the second system, which would also be rotatably mounted about a point, with the other end of the second system carrying the tool. In this way also, magnification of the template profile can be increased.

A third form of follower means employs rack and pinion means. A first racked member cooperates with the template, and a gear or system of gears passes on the racked member's movement to a second racked member, parallel to the first. In this way, movement of the first member over the template is translated and magnified into movement of the end of the second member, which would support the tool. This follower means could be adapted to use either a 'positive' or 'negative' type template, depending on the configuration of the gear or system of gears.

With all the above described follower means, accurate cooperation with the template profile provides an accurate curvilinear structure. The follower means may cooperate with the template in any suitable manner, for example in a sliding manner. Alternatively, the follower means could be provided with a wheel which is free to run along the template profile. If the template is a flat plate, the wheel may have a central groove within which the template runs to prevent deviation of the wheel from the template. If the template is threedimensional, the follower means may again be provided with a wheel, or possibly a ball/socket arrangement.

The follower means is preferably held in contact with the template, for example by spring means.

The other end of the follower means may be designed to carry or cooperate with any one of a variety of tools used in the positioning, construction or finishing of the curvilinear portion. It is also possible that a plurality of tools may be carried by the follower means, each one performing a different operation during construction. The type of tools carried will depend on the particular task being carried out.

As discussed above, the template may take any suitable form and may be a positive, negative or rotated scaled-down image of the curvilinear portion under construction. With a scaled-down template, the follower means should magnify the movements caused by following the template profile when moving the tool. With regard to the magnification, it is possible to exaggerate the profile of the template in one dimension relative to another. For example, when the template is mounted on a carriage, the exaggerated dimension may be the direction perpendicular to the track, with the dimension parallel to the track remaining as originally scaled.

The exaggeration enables the magnification required of the follower means to be reduced. For example, the dimension of the template parallel to the track may be 1:100 scale, but may be 1:10 scale perpendicular to the track.

A particularly preferred form of the method applies to the construction of structures in which cement is laid on reinforcing bars or a reinforcing mesh.

Accordingly, a further aspect of the invention provides a method of constructing a curvilinear portion of a building or other structure which is constructed from a framework of reinforcing bars or mesh, in which the positioning of at least some of the reinforcing bars or mesh is carried out with the assistance of a tool provided on a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the tool in a manner necessary to construct the framework in the approximate shape of the curvilinear portion.

This further aspect of the invention also provides apparatus for constructing a curvilinear portion of a building or other structure which is constructed from a framework of reinforcing bars or mesh, comprising a tool for positioning at least some of the reinforcing bars or mesh and a follower means movable in relation to a template for moving the tool, the template being configured such that movement of the follower means relative to the template is translated into movement of the tool in a manner necessary to construct the framework in the shape of the curvilinear portion.

Once the reinforcing bars or mesh are in position, concrete is normally sprayed over the framework and the surface is then finished, for example by sledging.

The apparatus may include suitable means for making holes in a surface on which a curvilinear portion of the structure is to be constructed, such as a drill head.

In this case, the positioning of the holes is critical and must be performed to maximum accuracy because the reinforcing bars are inserted into these holes, and therefore the initial positions of the holes determine, in plan view, the eventual shape of the portion.

Alternatively, the tool may simply include indicating means such as a marker which identifies the correct location at which a hole must be made. The drilling could then be performed manually.

The drilling or indicating operation may be repeated as many times as there are reinforcing bars to insert.

The positioning tool may, as an alternative or in addition to the drilling or marking means, be adapted to grip the individual reinforcing bars.

If the reinforcing bar being carried is to be inserted into the surface on which the curvilinear portion is to be constructed, the positioning tool holding the reinforcing bar can be moved to the correct location by movement of the follower means along the profiled edge of the template and the end of the reinforcing bar can then serve to indicate where to make a hole. The hole may be formed either manually or by the drilling means as discussed above. Alternatively, if the hole has already been formed, or the nature of the surface into which the reinforcing bar is to be mounted is such that a hole is not required before mounting, the positioning tool may simply serve to insert the reinforcing bar into the surface at the exact location required. The grip can then be released.In either case, the reinforcing bar can be cemented in position, either manually or by a cementing means attached to the positioning tool.

The reinforcing bars could be provided in an unformed state, in straight lengths for example, and means could then be provided on the positioning tool for forming the reinforcing bar into the required shape.

Preferably, however, the reinforcing bars are preformed according to the shape in cross-section of the curvilinear portion being constructed.

The reinforcing bars may be formed of any suitable material and are preferably formed from steel, glass fibre or carbon fibre. Further, if steel is used, it is preferably high yield steel or rebar.

It is also possible for the positioning tool to grip and position any other reinforcing members which are not to be inserted into the surface on which the curvilinear surface is being constructed, but which are to be connected to the reinforcing bars already in place in this surface. For example, such reinforcing members might be horizontal sections which are laid across the vertical bars inserted in the surface, both the horizontal and vertical sections forming the reinforcing mesh or network onto which the concrete is added.

The reinforcing members which are to be attached to existing reinforcing bars might be formed from high yield steel, glass fibre or carbon fibre bars. However, it is preferable that these members are formed from steel cable. Preferably, the steel cable has a similar or greater tensile strength to that of the high yield steel bars. By using steel cable for these members, the construction process is much simpler than if preformed high yield steel were used. If the members were to be preformed from high yield steel, very complex and individual shapes would be needed since almost every reinforcing member would have a different profile, unlike the vertical bars.If the reinforcing members were not preformed, but were made from straight lengths of high yield steel, distortion of the curvilinear portion defined by the vertical bars already in place could result once the reinforcing members are attached to the vertical bars. Steel cable therefore has the advantage that it is strong but flexible, and will not distort the existing structure.

The steel cable is preferably stored on a drum.

The cable would then be fed to the positioning tool where it is positioned on the existing structure. In this case, it would be advantageous to provide feeding means and cutting means so that the steel cable may be handled prior to attaching it to the existing structure.

It is of course possible to use a combination of steel cable and high yield steel, glass fibre or carbon fibre bars for the reinforcing members where the structure requires additional rigidity.

As an alternative to using steel cable, it is also possible to use a reinforcing mesh or netting which is attached to the reinforcing bars. This reinforcing mesh is preferably formed from steel also.

Whether the reinforcing members are formed from high yield steel, glass fibre, carbon fibre, steel cable or steel mesh, it would be preferable to incorporate into the positioning tool means for fixing the reinforcing members to each other or to the reinforcing bars. This might take the form of a tying or stapling device adjacent to the gripping means. The fixing could, however, be performed manually.

It is preferable in either case to attach the steel cable or steel mesh to the external surface of a concave curve defined by the vertical bars in position.

The grip itself may take any form suitable and preferably is in the form of a clamp. In certain cases, where the size of the reinforcing bar being positioned is large, more than one grip may be provided.

The end result is that a reinforcing network is accurately constructed, either from high yield steel, glass fibre, carbon fibre, steel cable or steel mesh or a combination of these, to produce a three-dimensional steel basket.

Preferably, the method of constructing a curvilinear portion includes the step of attaching a layer of flexible material to one side of the reinforcing network. Such a layer could be made from hessian or fine wire mesh. The purpose of this layer is to contain the concrete while it is being applied from the other side of the reinforcing network.

In a preferred form, the method of constructing a curvilinear portion also includes the step of providing means for applying concrete to the curvilinear portion.

Preferably, this concrete-applying means consists of apparatus suitable for spraying concrete, such as gunite or shotcrete, onto the curvilinear structure. This apparatus may include compressors and cement and water hoppers.

The tool used in finishing the curvilinear portion may perform any function which enhances or defines more precisely the surface of the curvilinear portion once the basic structure has been formed. Preferably, the finishing tool includes sledging means.

Accordingly, viewed from a further aspect, the invention provides a method of fabricating a surface of a structure through the use of a sledging means provided on a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the sledging means corresponding to the desired shape of the curvilinear portion.

This third aspect of the invention also provides apparatus for fabricating a surface of a structure, comprising a sledging means and a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the sledging means corresponding to the desired shape of the curvilinear portion.

The sledging means may consist of a rigid structure having an edge or surface with the desired surface profile of the structure being constructed. Once concrete has been applied to the reinforcing mesh, and with the concrete still soft, the follower means with the sledging means provided thereon is moved around the template, with the location of the sledging means being defined with reference to the template as previously described. As the sledging means is moved along the curvilinear structure, so its profiled edge moves across the surface of the soft concrete. In this way, by virtue of the accurate positioning system, the surface of the curvilinear portion can be defined exactly according to the instructions. The sledging means may be used for internal or external walls, or ceilings, for example. The operation may be repeated over successively applied thin layers of concrete.

The finishing tool may include other surface enhancing apparatus, such as grinding or sanding means, means for applying a layer of plaster to the concrete, or means for painting the concrete or plaster, for example. These tasks could, however, be performed manually.

Should it be desired to apply a layer of plaster or other material to the concrete, either by the finishing tool or manually, the sledging means may be used to smooth out or improve the accuracy of the new surface formed by the plaster or other material. The tool may be adjusted to account for the plaster thickness but still be adapted to follow the same desired profile.

All of the above types of tool may be adapted to be used with either apparatus which is fixed in position or apparatus which may move.

The above method is equally suitable to be performed on convex or concave curvilinear surfaces, and on interior or exterior walls.

The methods and apparatus described above may be employed to perform any task requiring accuracy during the construction of a curvilinear portion, in addition to those tasks already described. Such additional tasks may include the fitting of any fixtures which are required, such as doors, windows or skirtings, for example.

It is possible, when the carriage/track method is being used, to connect several carriages together on one track, with each carriage carrying a different tool.

Each stage of the construction process can then be performed by adjacent carriages sequentially with reference to their individual templates. It is of course equally possible for a single carriage to carry more than one tool to enable tasks to be completed in succession. Either of these arrangements may increase the speed with which the curvilinear portion is constructed.

As primarily described above, it has been assumed that the methods would be performed by manually operating the equipment according to a sequence of instructions given by the architect. However, it will be understood that the methods and apparatus are particularly suited to automation. By providing motors and sensors on the follower means, template, track, carriage or tool, it would be possible to control the system automatically from a central location.

Preferably, therefore, the method includes the step of providing automated control means for controlling the method and any apparatus used therein. Further, the automated control means is preferably a CAD/CAM system.

Such a system would allow a set of numerical instructions for controlling the apparatus to be produced directly from the architect's original design.

Certain embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Fig. 1 shows an overall plan view of a curvilinear portion to be built, and apparatus according to one embodiment of the invention mounted on a track during the construction process; Fig. 2A shows a 1:100 scale 'positive' template having a profile corresponding to the curvilinear portion of Fig. 1 in plan; Fig. 2B shows a 1:100 scale template having a 'negative' profile corresponding to the curvilinear portion of Fig. 1; Fig. 2C shows a template of 1:100 scale in length with its width dimensions exaggerated; Fig. 2D shows a 1::100 scale template having a 'positive' profile which has been rotated through 1800; Fig. 3A shows in elevation a carriage having two gears, a rack and a template; Fig. 3B shows in elevation a carriage having three gears; Fig. 4 shows the carriage and template in plan with a pantograph mechanism; Fig. 5 shows the carriage and template in plan with a lever system mechanism; Fig. 6 shows the carriage and template in plan with a rack and pinion mechanism.

Referring to Fig. 1, lengths of track 1 are connected together and laid adjacent to where a curvilinear portion 2 is to be constructed.

A carriage 3, template 4, rack and pinion mechanism 5 and tool 6 are also provided. By moving carriage 3 in the direction shown by arrow A, template 4 is caused to move in the direction shown by arrow B, as will be described below. The rack and pinion follower mechanism 5 translates the profile of the template, which is a scaled-down version of the required profile of the curvilinear portion, to the tool 6 which then traces out the full-size curvilinear profile, as the carriage moves along the track. The movement of the template and carriage must be synchronised so that at each point along the track, the follower mechanism 5 cooperates with the correct portion of the template 4 so that the tool is correctly positioned.

With reference to Figs. 2 and 3, depending on the particular follower mechanism used, the template may have a profiled edge corresponding to a scaled-down version of the curvilinear portion under construction, i.e. a 'positive' profile. This is shown as 7 in Fig.

2A. Alternatively, the template may have a 'negative' profile as shown as 8 in Fig. 2B, in which the profiled edge corresponds to a scaled-down mirror-image version of the curvilinear portion under construction. With either type of template, it is also possible to exaggerate the width dimensions of the template, as shown by 9 in Fig. 2C. Depending on the particular mechanism used to transfer the template profile to the tool, the template profile may also need to be rotated through 180C as shown by 10 in Fig. 2D.

Referring to Fig. 3A, carriage 3 is provided with two axles 11, on one of which is provided a gear 12.

Template 4 is mounted on a rack 13 and the combined template and rack are free to move along the carriage and relative to it, parallel to the track. A further gear 14 is provided between gear 12 and rack 13.

Therefore, the gear and rack system is such that, when the carriage is moved in the direction of arrow A, the template and rack are caused to move relative to the carriage in the opposite direction, shown by arrow B.

This system therefore provides the necessary motion to the template so that the mechanism for transferring the profile to the tool, which mechanism is fixed to the carriage and cannot move relative to it, is able to move along the profiled edge of the template and trace out the required curvilinear profile at the tool end: This arrangement would require a template such as those shown in Figs. 2A, 2B or 2C.

Fig. 3B shows an alternative embodiment for the carriage 3 in which a third gear 15 is provided between gears 12 and 14. This arrangement therefore causes template 4 to move relative to the carriage in the same direction as the carriage, as shown by arrow C. Such an arrangement would then require a template with a profile which has been rotated through 1800 (as shown in Fig.

2D), in either a 'positive' or 'negative' form, because the mechanism would begin from the opposite end of the template to that started from in the embodiment of Fig.

3A, but the carriage would still begin in the same position.

Figs. 4 to 6 show three different possibilities for the mechanism for following the template profile and for transferring this motion to the tool.

Fig. 4 shows a pantograph 16 cooperating with template 4. The pantograph consists of four rods 17, 18, 19 and 20, with the two shorter rods 19 and 20 forming a parallelogram with portions of the longer rods 17 and 18. The rods are rotatably connected at points A, B, C and D, and rod 17 is rotatably secured to the carriage at point E. At point F there is provided a pointer or wheel 21 which is suitable for following the profiled edge 22 of template 4, and which is constrained so as to be able to move only in a direction perpendicular to the direction of motion of the template 4. Also attached to this point F is a spring 23 which has its other end fixed to the carriage. The spring therefore provides a force at point F towards the profiled edge 22 in order to keep pointer or wheel 21 in contact with the edge. At point G, an arm 24 is provided on which a tool may be mounted.

As the template 4 is moved in either direction shown by arrow A, wheel or pointer 21 and point F will move in or out relative to the carriage, following the profile of the template. Because of the geometry of the pantograph 16, point G will move in the same direction as point F but by a magnified amount. If the scale of the template is 1:100, then point G should move a distance 100 times greater than that moved by point F.

The amount by which the pantograph magnifies the movement of point F may be adjusted by altering the positions of some or all of the points E, F and G.

Fig. 5 shows a lever mechanism 25 employing three levers 26, 27 and 28 which are rotatably fixed together at their ends by members 29 and 30. Attached to member 30 is a wheel 31 which cooperates with the profiled edge 32 of template 4. Lever 27 is rotatably fixed to the carriage at a point A which is closer to member 30 than member 29 in order to magnify the movement of the wheel 31 along the template profile.

Because of the way the levers and end members are attached, wheel 31 is constrained such that it can only move in a direction which is substantially perpendicular to the movement of the template 4. Therefore, wheel 31 follows the contour of the template, and this causes member 29 to move by a magnified amount in the opposite direction. Therefore, template 4 should have a 'negative' profile. The required tools may be attached to the mechanism at point 33 on member 29.

Fig. 6 shows a third embodiment of the mechanism, employing a rack and pinion arrangement. The mechanism comprises a first member 34 mounted perpendicular to template 4 and able to move between guides or bearings 35. First member 34 is provided with a rack 36 and a spring 37 which urges first member 34 towards the profiled edge 38 of template 4. At the template end of the first member is provided a wheel 39 which cooperates with the profiled edge as before.

Small gear 40 cooperates with rack 36 and is rotated by lateral movement of the rack. Attached to the same shaft as the small gear 40 is a large gear 41, which in turn cooperates with a second rack 42 mounted on a second member 43, also able to move between guides or bearings 44.

Therefore, it can be seen that a small movement of wheel 39 perpendicular to the direction of movement of the arrow will cause end 45 of second member 43 to which tools may be attached to move a large amount in the opposite direction. Therefore, this mechanism requires a 'negative' profile on template 4.

Tool 6 may be any suitable tool required in the construction process during positioning, constructing or finishing the curvilinear portion. For example, tool 6 may be a pointer, drill, grip or clamp, feeding means, cutting means, stapler, concrete spraying apparatus, sledging means, grinding or sanding means, plastering or painting means, as previously discussed in the introduction. It is also possible to use more than one tool simultaneously, with each tool being controlled either from the same template or from different templates.

Various alternatives to the embodiments described above are possible. For example, a template could be fixed at a location, on a tripod for example, and would have a profile corresponding to the curvilinear portion under construction relative to that position, for example a circular room built from a disc template fixed at the room's centre.

Claims (32)

Claims:

1. A method of forming a curvilinear portion of a building or other structure, wherein a template profiled to provide a desired shape of the curvilinear portion is used in controlling the movement of a tool employed in the construction or finishing of the curvilinear portion.

2. Apparatus for constructing or finishing a curvilinear portion of a building or other structure, comprising a tool and a template profiled to provide a desired shape of the curvilinear portion, the template being arranged for use in the control of the movement of the tool.

3. Apparatus as claimed in claim 2 wherein the tool is mounted on a follower means which cooperates with the template such that relative movement between the follower means and the template causes or enables the follower means to follow the profile of the template and move the tool in the desired manner.

4. Apparatus as claimed in claim 2 or 3 wherein the apparatus is able to move along a predetermined path such that the shape of the curvilinear portion under construction as produced by the movement of the tool is defined both by the profile of the template and by the predetermined path followed by the apparatus.

5. Apparatus as claimed in claim 5 wherein the template, follower means and tool are mounted on a carriage which runs along a track.

6. Apparatus as claimed in claim 5 wherein the template takes the form of an elongate element, one edge or side of which lies generally in the direction of carriage movement and is profiled in accordance with the curvilinear shape.

7. Apparatus as claimed in claim 5 or 6 wherein gearing means are provided on the carriage which cause the template and follower means to move relative to one another.

8. Apparatus as claimed in claim 8 wherein the template is mounted on a rack such that it is driven by the gearing means.

9. Apparatus as claimed in claim 5 or 6 wherein the template and follower means are moved relative to one another by an electric motor.

10. Apparatus as claimed in any of claims 3 to 9 wherein the follower means is a pantograph.

11. Apparatus as claimed in any of claims 3 to 9 wherein the follower means comprises a lever system.

12. Apparatus as claimed in claim 11 wherein the lever system comprises at least one lever and is fixed such that it can rotate about a point in the same plane as the template.

13. Apparatus as claimed in any of claims 3 to 9 wherein the follower means employs rack and pinion means.

14. Apparatus as claimed in claim 13 wherein the rack and pinion means includes a first racked member for cooperation with the template, and at least one gear means which passes on the movement of the racked member to a second racked member.

15. Apparatus as claimed in any of claims 3 to 14 wherein the follower means is provided with a wheel which is free to run along the template profile.

16. Apparatus as claimed in any of claims 2 to 15 wherein the template is planar in configuration.

17. Apparatus as claimed in any of claims 2 to 15 wherein the template is three-dimensional.

18. Apparatus for constructing a curvilinear portion of a building or other structure which is constructed from a framework of reinforcing bars or mesh, comprising a tool for positioning at least some of the reinforcing bars or mesh and a follower means movable in relation to a template for moving the tool, the template being configured such that movement of the follower means relative to the template is translated into movement of the tool in a manner necessary to construct the framework in the approximate shape of the curvilinear portion.

19. Apparatus as claimed in claim 18 wherein the tool includes means for making holes in the surface on which the curvilinear portion is to be constructed.

20. Apparatus as claimed in claim 18 wherein the tool includes indicating means which identifies the correct location at which a hole must be made for the reinforcing bar or mesh.

21. Apparatus as claimed in claim 18, 19 or 20 wherein the positioning tool is adapted to grip individual reinforcing bars.

22. Apparatus as claimed in any of claims 18 to 21 wherein the tool includes means for forming the reinforcing bar into the required shape.

23. Apparatus as claimed in any of claims 18 to 22 wherein the tool includes means for fixing reinforcing members to each other or to the reinforcing bars.

24. Apparatus as claimed in any of claims 18 to 23 wherein the tool includes sledging means.

25. A method of constructing a curvilinear portion of a building or other structure which is constructed from a framework of reinforcing bars or mesh, in which the positioning of at least some of the reinforcing bars or mesh is carried out with the assistance of a tool controlled by a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the tool in a manner necessary to construct the framework in the approximate shape of the curvilinear portion.

26. The method as claimed in claim 25 including the step of attaching a layer of flexible material to one side of the reinforcing network.

27. The method as claimed in claim 25 or 26 including the step of applying concrete to the reinforcing network.

28. A method of fabricating a surface of a structure through the use of a sledging means controlled by a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the sledging means corresponding to the desired shape of the curvilinear portion.

29. Apparatus for fabricating a surface of a structure, comprising a sledging means and a follower means movable in relation to a template, the template being configured such that movement of the follower means relative to the template is translated into movement of the sledging means corresponding to the desired shape of the curvilinear portion.

30. Apparatus as claimed in claim 29 wherein the sledging means consists of a rigid structure having an edge or surface with the desired surface profile of the structure being fabricated.

31. Methods of forming a curvilinear portion of a building or other structure substantially as hereinbefore described with reference to any of the accompanying drawings.

32. Apparatus for constructing or finishing a curvilinear portion of a building or other structure substantially as hereinbefore described with reference to any of the accompanying drawings.