Patent Publication Number: US-2007107374-A1

Title: Brick laying device

Description:
The invention relates to a brick-laying device; in particular such a device for assisting in the brick-laying process.  
      Various problems are known with conventional brick-laying processes. In such processes a course of bricks is laid together with mortar and further courses laid on top until a wall, pillar or other brick-work is completed. The standard of the brick-work achieved is normally down to the skills of the individual brick layer, in particular in ensuring an even and consistent gap between each successive course of building bricks or blocks. The main problem in inexpertly laid brick-work is the inconsistency of the finished product. For example the mortar beds vary in thickness giving way to different heights of the brick-work from corner to corner as a result of which the wall may not be level. Bricks can be laid in different planes to one another as a result of the inherent softness of the mortar bed. In particular, any pressure that is applied to the brick forces it further into the mortar bed either directly when the brick is being laid or indirectly when pressure is being applied from an additional course above. Because all bricks cannot be laid with the same pressure these inconsistencies come to light over the finished wall. As a result, even for skilled bricklayers, achieving high quality brick-work is a time consuming task. There is currently a decline in the number of skilled bricklayers who can achieve a good standard of work which in turn gives rise to a problem with the future supply of brick layers as training facilities may not be available.  
      One known proposed solution to the problem is described in French patent application no. 2600359. According to the arrangements disclosed in this document, a brick laying aid includes a latticed structure having marginal elongate beads. The structure is laid atop a course of bricks with the beads lying along the edges and mortar is added. Once the mortar has dried the bead can be removed or left in place. In either case various problems arise with this arrangement. Because of the external beading the device needs to be positioned precisely onto the brickwork. Mortar is effectively placed within the device, between the beads, such that when the next course of bricks is laid there will be no excess mortar squeezed from between the bricks such that a satisfactory bond may not be obtained. The recess formed by removing the bead may be too deep and the beads may also prevent the effective shedding of water which can be essential for longterm performance. Furthermore the device requires significant amounts of material and, because of the elongated cylindrical beads, can give rise to production and storage problems.  
      Another proposed solution is described in International patent application number WO 02/090688 commonly assigned herewith and incorporated herein by reference. This document describes a spacer that is laid along a course of brick-work and of smaller width than the brick-work such that it is fully enveloped in mortar during the brick-laying process. The spacer comprises a lattice or mat on which a plurality of spacer elements are joined together by a support structure comprising elongate ribs. The spacer elements are provided at intervals in the elongate direction and the arrangement provides an improved bond because the entire spacer in enveloped in mortar. However, the bond between the bonding material and the building block is not ideal as the bonding material can ‘bottom out’ when the next course of building blocks is placed on top of the spacer and bonding material, the bonding material being squeezed out where the lattice meets the building block. This results in an incomplete bond between building blocks and bonding material at the location of the spacer elements. The ribs joining the spacer elements can also prevent a complete bond between bonding material and lattice mat. Furthermore, although the spacer is designed to be completely enveloped in bonding material, it may protrude from the bonding material if not correctly located on the building block.  
      Various areas are available for further improvement of the known arrangements. It is desirable to increase yet further the structural stability of known spacer mats and also to reduce the mass of material, such as plastic, at the end of each course of brick-work. It is also desirable to reduce the amount of material in the spacers. It is yet further desirable to provide a spacer capable of compact storage. Although the systems described above provide significant improved bonding between the spacer and the mortar, it is desirable to improve the bonding yet further. Furthermore it is desirable to improve the stability of building elements attached to the end of a course of bricks and to reduce the mass of spacer material at the end of courses whilst retaining the possibility of attaching building elements.  
      The invention is out set out in the claims.  
      Various advantages are attached to the aspects of the invention set out in the claims. For example because spacer elements are provided in a non-parallel configuration, the structural strength of the spacer mat is enhanced. In particular “parallelogram” collapse of the spacer mat is avoided. Furthermore, this configuration reduces the amount of spacer mat material at the end of a course of bricks. Because of the provision of cut-out portions in the spacer elements the amount of material is reduced and spacer mats can be stacked more compactly. Because the support elements are significantly inset relative to the edges of the spacer mat yet further improved bonding of mortar or other bonding material around the support elements is achieved. The provision of first and second parallel end spacer elements once again reduces the amount of spacer mat material at the end of the course of bricks.  
      In other embodiments, the spacer elements of the present invention are enveloped in bonding material in both dimensions and tapered top and bottom to allow maximum contact between the bonding material, such as mortar, and the brick. This allows an improved bond to be obtained.  
      Because a continuous spacer element is located at the end of the spacer this enables the fixing of door and window jambs by means of screws without the need for rawl plugs or fixing anchors. Because the end spacer element is thickened with respect to the other spacer elements this improves strength and support for screw fixings.  
      The provision of retaining clips assist in the correct location of the spacer in relation to the brick on which it is placed. This ensures that the spacer will not protrude from the mortar, or bonding material.  
      The provision of the support strips in the middle of the spacer elements enabling the supports to be encased in the bonding material, to improve the strength of the bond between brick and mortar, top and bottom. 
    
    
      Embodiments of the invention will now be described, by way of example, with reference to the drawings of which:  
       FIG. 1   a  is a perspective view of the spacer mat according to a first embodiment of the present invention;  
       FIG. 1   b  is a perspective view of a length of spacer mat;  
       FIG. 2  is a perspective view showing two spacer mats stacked for storage;  
       FIG. 3  shows a detail of an end portion of a spacer mat to be laid at the end of a course of brick-work;  
       FIG. 4  shows an alternative form of spacer mat;  
       FIG. 5  is a perspective view of the first embodiment of the invention;  
       FIG. 6  is a plan view of the first embodiment;  
       FIG. 7  is a side view of the first embodiment;  
       FIG. 8  is a side view of a wall constructed according to the present invention;  
       FIG. 9  is a perspective view of the spacer mat located with a retaining clip according to a further embodiment of the invention;  
       FIG. 10  is a side view of a door frame attached to a wall according to a further embodiment of the invention. 
    
    
      Referring to  FIG. 1   a  the arrangement is designated generally  10  and includes a course of bricks or blocks  12  with a spacer mat  14  laid thereon. The spacer mat  14  comprises a pair of parallel ribs or support strips  16  along which are spaced a plurality of vertical spacer elements  18  extending upwardly and downwardly therefrom. The spacer mat  14  is elongate and of width slightly smaller than that of the course of bricks  12  and the spacer elements  18  are arranged at intervals in the elongate direction along each support strip  16 .  
      The support strips  16  and spacer elements  18  are preferably formed integrally of plastic material such as a polymer material, polypropylene, PVC, HDPE or nylon. The support strips  16  are preferably circular in cross-section with 3 mm diameter and the spacer mat can be formed in any appropriate manner as will be apparent to the skilled person for example injection moulding, extrusion or a spinning dye, preferably by pressure injection method. The spacer mat can be cut to an appropriate length or shape to deal with corners and angles and the spacer elements  18  preferably extend upwardly and downwardly slightly less than the desired spacing between courses of bricks to take into the account the mortar film that tends to form on the top of the spacer elements  18 .  
      It will be appreciated that the invention can be utilised other than in straight courses of brick-work. For example a pillar arrangement comprises effectively a hollow square formed of bricks in a one and a half brick arrangement. In this case the spacer is cut into lengths and laid atop the course of bricks after which the next course is laid in the manner described above. Generally the spacer mat can fit any angle or curve.  
      The spacer mat  14  can be provided in lengths or rolls dependent on the material or can be provided as individual elements for example spacers to fit single brick as shown in  FIG. 1   a.    
      In the embodiment shown in  FIG. 1   a  the width dimension of the spacer is preferably 80 mm, less than that of a standard brick, to enable the spacer to be wholly embedded within bonding material (with approximately 10 mm clearance at either side). The spacer mat  14  is placed on top of the brick course. Once the spacer mat is in place mortar is applied and the bricklayer can then position the next layer of bricks by applying downward pressure to compress the mortar until the underside of the brick rests on the spacers. During the process the mortar will pass between the support strips ensuring that the necessary bonding in successive layers has occurred and that the integrity of the structure is assured. Because the spacers are arranged at intervals and are inwardly positioned relative to the course of bricks, when downward pressure is applied excess mortar can be removed ensuring a firm bed.  
      Significantly it will be seen that the support strips  16  extending in the elongate direction are joined by support strips  22  perpendicular to them in the form of cross-bars, providing a generally rectangular grid. The spacer element  18  are located at each vertex of the support elements  16  and  22 . The spacer elements  18  extend generally at 45° to the support elements and adjacent spacer elements are orientated perpendicular to one another such that the orientation of the spacer elements alternates in the elongate direction (i.e. in the direction of the course of bricks) as well as the width direction (i.e. transverse to the elongate direction in the plane of the course of bricks). The support elements  16 ,  22  pass generally through the centre of the spacer elements  18  such that the spacer elements project symmetrically upwardly and downwardly as well as inwardly to and outwardly of the spacer mat. The spacer elements are generally H-shaped, elongate in the plane of the course of bricks and the direction of orientation and with central cut-outs  24  top and bottom. The spacer elements  18  taper from their vertical centres top and bottom.  
      As a result of the configuration various advantages are realised. By disposing the spacer elements non-parallel to the lateral support elements the amount of material at the end of the course of bricks is reduced. By disposing the spacer elements non-parallel to each other the risk of collapse is reduced in particular in relation to the possibility of a shear deformation of the spacer mat. Tapering of the spacer elements reduces the possibility of “bottoming out” i.e. mortar being pressed out between a top and bottom of the spacer element and the adjacent brick. Provision of the cut-outs reduces the amount of material without affecting the structural strength. In practice as much as 25% less material can be used because of the cut-outs.  
      The spacer elements are located at regular intervals in both dimensions, providing a number of spacers, in this embodiment eight, underneath each brick ensuring that the brick is level and plumb. The spacer elements intermediate the ends are non-continuous across the width or lateral dimension of the space mat and 20 mm in length with approximately 52 mm separation between inner tips, being joined in the lateral direction by the further support strips  22  defining a centre to centre spacing of the spacer element of 66 mm. In cross section the spacer elements comprise a thickened centre portion of approximately 4 mm width tapering to a point top and bottom. The spacer elements have a height of 9 mm leaving 1 mm mortar top and bottom when embedded.  
      Because the support strips  16  and  22  are provided intermediate the top and bottom of each spacer element  18  this allows the support strips to be encased more effectively in bonding material. Furthermore because the spacer elements  18  are provided laterally symmetrically about the support elements  16 , the support elements  16  are inset significantly from the edge of the spacer mat and from the course of bricks providing improved bonding with and enveloping in mortar.  
      Referring to  FIG. 1   b  a length of spacer mat is shown having length approximately 870 mm. It will be seen that the spacing between successive adjacent lateral support elements  22  alternates between a wider and a narrower spacing of 68 mm and 45 mm respectively. Two wider-spaced zones and one central narrower-spaced zone define a region of the spacer mat arranged to be aligned with a brick, the region having a total length of 181 mm.  
      Referring now to  FIG. 2 a  further advantage of the cut-outs  24  and the spacer elements  18  can be seen. Respective spacer elements  14  and  18  can be stored by overlaying, one on the other, the support elements  16  of one spacer mat  14  laying in the recesses  24  of the adjacent spacer mat  14 . As a result the storage volume is reduced, reducing the storage and transportation costs accordingly. This is enhanced by providing the support elements centrally to the spacer elements.  
      In a further embodiment of the invention  1  as shown in  FIG. 1   a,  retaining clips  17  can be attached to ensure the correct location of the spacer not relative to the brick. The retaining clip  17  comprises a right angle, both arms being preferably approximately 10 mm in length. One arm of the clip is positioned parallel to the top edge of the brick and clips onto the support strip  16 . The other arm is perpendicular to the first arm, and engages on the external edge of the brick and prevents the spacer from moving from its proper location. The retaining clip  17  is preferably formed of plastic material of similar or the same type to the spacer mat. Retaining clips  17  can be used in conjunction with the spacer mat to ensure that the mat is correctly positioned on the bricks, to remove the risk of the mat protruding from the bonding material during brick-laying.  
      In an alternative embodiment the support strip or element  16  can be provided close to the edge of the course of brick-work by appropriate dimensioning of the spacer mat  14  and by reducing the inset of the support element  18  relative to the spacer element  18 .  
      Referring to  FIG. 3  an end portion of a spacer mat  14  to be provided at the end of a course of brick-work is shown in more detail. It will be seen that first and second end pieces  26  extend between the spacer elements  18  at the end of the spacer mat  14 . A first end piece  26  extends between the centres of the spacer elements  18  and can, for example, replace the lateral support element  22 , or the lateral support element  22  can be increased in height and thickened as appropriate. A second end piece  26  is shown spaced from and parallel to the first end piece  26  and extending between the inner end of the respective spacer elements  18 . The end pieces  26  are generally of a similar height to the spacer elements  18  and of increased thickness in relation to the spacer elements for example between 4 and 8 millimetres preferably 6 millimetres. As a result when building elements such as a window or doorjamb (not shown) are attached to the end of the course work the end pieces  26  can act as fixing anchors for screws or other fixings such that rawl plugs and the like are not required. The provision of two spaced and parallel end pieces  26  provide additional stability of fixings passed through both end pieces.  
      It will be appreciated that the spacer element can be placed at any appropriate orientation, for example in the range of 10° to 80° more preferably 30° to 60° unless preferably 45°. Of course this range also includes mirror inversions of the angles. In addition although the spacer elements are shown as having alternating orientations, any orientation pattern can be adopted for example two adjacent spacer elements orientated in the first direction, next to in non-parallel direction as so forth or any other appropriate pattern. Furthermore, curved spacer elements can be provided.  
      In a further embodiment shown in  FIG. 4  the spacer elements  18  are shown oriented parallel to the width direction of the spacer mat  14  and with cut-out portions  24  arranged to receive, and aligned with the support elements  16  to provide improved stacking. The spacer elements are approximately 20 mm in length and the overall width of the spacer mat from spacer tip to spacer tip is 80 mm, the spacing between the support strips  16  being 60 mm. Once again the transverse spacer elements define alternating narrower and wider regions of respective dimensions 33 mm and 80 mm defining a zone of length 193 mm corresponding to a brick on which the spacer mat is laid. As with the embodiment described with reference to FIGS.  1  to  3 , the mat spacing coincides with the brickwork bonding providing an improved bond in this way.  
      Referring to  FIG. 5  the arrangement is similar in general configuration and construction to that of  FIG. 1  and share similar reference numerals where appropriate.  
      However it will be seen that an end spacer element  15  in the length dimension of each spacer mat is provided which is continuous and preferably thickened in relation to the other spacer elements. The support strips  16  form the elongate edges of the spacer, and the continuous end spacer elements  15  form the shorter edge of the spacer, perpendicular to the support strips. In cross section the spacer elements  518  have a height of 9 mm and comprise a thickened centre portion of approximately 4 mm width tapering to a point top and bottom. Because the spacer elements are tapered in the vertical direction when downward pressure is applied maximum contact is allowed between the mortar and the brick, providing an improved bond.  
      Referring to  FIG. 10 , window/door jamb  20  is shown attached to the end spacer element  15  with screws  19  removing the need for rawl plugs or fixing anchors.  
      In a further embodiment of the invention as shown in  FIG. 9 , retaining clips  17  can be attached to ensure the correct location of the spacer, relative to the brick. The retaining clip  17  comprises a right angle, both arms being preferably approximately 10 mm in length. One arm of the clip is positioned parallel to the top edge of the brick and clips onto the support strip  16 . The other arm is perpendicular to the first arm, and engages on the external edge of the brick and prevents the spacer from moving from its proper location. The retaining clip  17  is preferably formed of plastic material of similar or the same type to the spacer mat. The retaining clips  17  can be used in conjunction with the spacer mat to ensure that the mat is correctly positioned on the bricks, to remove the risk of the mat protruding from the bonding material during bricklaying as shown in  FIG. 9 .  
      It will be appreciated that the invention can be utilised other than in straight courses of brickwork. For example a pillar arrangement comprises effectively a hollow square formed of bricks in a one and a half brick arrangement. In this case the spacer is cut into lengths and laid atop the course of bricks after which the next course is laid in the manner described above.  
      As a result an improved building structure is provided. The spacers are provided internally of the brickwork course allowing a firm bedding to be obtained without blocking excess mortar from escaping. The spacer elements are tapered to increase the amount of mortar in contact with the bricks to either side of the spacer mat, and to prevent the risk of ‘bottoming out’. The end spacer element is continuous and thickened to allow attachment of window/door jambs. The support strips are located in the middle of the spacer elements, to ensure that they are encased in bonding material, to increase the bond between brick and mortar and provide a more stable structure.  
      It will be perceived that the invention gives numerous advantages in addition to those specified above. This spacer is robust, chemically and temperature inert, stable and long-lived and chemically strong. It is simply and intuitively used and gives rise to a stable strong structure without effecting the appearance of the structure.  
      The spacer elements themselves can be of any appropriate form and dimension and can be formed integrally with the support structures or bonded or adhered to them. The distribution of spacer elements can be varied as required to take into account building block dimensions, right angles or angled joints. The support strips themselves can also be formed of any appropriate material not limited to plastic material and including, for example, ceramics, cement or metal materials. The spacer elements can be formed in lengths or in other shapes and/or of other materials to meet specific brick-work requirements or for use with other types of building blocks such as breeze-blocks as appropriate.