SE538843C2 - Stackable foundation spacing and magazine for such spacers - Google Patents

Abstract

22 ABSTRACT Stackable foundation spacer adapted to support a reinforcement grid, wherethe foundation spacer comprises a lower bearing surface adapted to beplaced on a ground surface for the concrete, a first support surface adaptedto support the reinforcement grid in a p|ura|ity of positions, and an outercircumferential side wall connecting the lower bearing surface with the firstsupport surface, where the outer circumferential side wall is inc|inedoutwards from the lower bearing surface to the first support surface with anangle oi, and where the shape of the first support surface is larger than amesh in the reinforcement grid that is to be supported. The advantage of theinvention is that a reinforcement grid can be supported by a spacerregardless of the position of the spacer. A further advantage is that thespacer is stackable. The foundation spacer can be distributed either manuallyby hand or by a feeder device in a semi-automatic or automatic way. (Figure 2)

Description

SPACERTECHNICAL FIELD The present invention relates to a stackable foundation spacer adapted tobe used for supporting reinforcement grids in concrete constructions. Thesize and shape of the spacer is such that it will give reliable support to thereinforcement grid even if the spacers are placed randomly on the groundsurface. The spreading of the spacers can be made manually or by theuse of a semi-automatic or automatic feeder. Due to the fact that thepositioning of the spacers is not critical, a cost-effective spacer isprovided.

BACKGROUND ART Concrete constructions are normally provided with some kind ofreinforcement to increase the strength. The reinforcement can be singlereinforcement bars (rebars), reinforcement grids or different kinds of fibresor other. l\/lost common are reinforcement grids made from reinforcementbars of steel when larger areas are to be covered. For smaller areas or asa complement to the grids, single reinforcement steel bars are used.

To achieve the required properties in a construction, the reinforcement isplaced at different heights. This height creates a concrete cover aroundthe reinforcement in the finished construction. Fieinforcement spacers areused to simplify the work of positioning the reinforcement at the prescribedheight and to maintain it there through the process until the concrete hasburned. The type of spacer used is influenced from e.g. regulations, the surrounding environment, natural resources or aesthetic opinions.

The concrete cover is defined as the smallest distance between thereinforcement material and the concrete surface of the completedconstruction. A concrete cover which differs from the requirements can negatively affect the strength and life cycle of a construction. Therequirements on a concrete cover can be set by national regulations andmay vary depending on type of construction and on the surroundingenvironment. One purpose of the concrete cover is to prevent moisture toreach the reinforcement steel, in order to avoid the negative effectscorrosion has on the construction. Corrosion will, through its expansion,slowly break apart the nearby concrete, which causes more moisture toreach the steel which in turn accelerates the corrosion process. Over timethis will weakens the construction strength.

To provide support for the reinforcement, reinforcement spacers are used.These are often made from plastic and are designed to facilitate that theconcrete fully embraces the reinforcement and the spacers. Air pockets inthe final construction must be avoided. Depending on the shape of thespacer, it must be provided with some kind of apertures in order to provideescape ways for air to disappear when concrete is poured upon them.

Reinforcement spacers are made from different materials. l\/lost commonare spacers made from plastic, but steel, concrete and other materials arealso used. Plastic spacers have several advantages compared to othermaterials, such as ease of handling, low weight and generally low price,the manufacturing process is fast and spacers can easily be formed to adesired shape. Concrete spacers can be used in most constructions.However, the material makes them heavy and the design makes themmore complicated to work with. They are primarily used when plastic is notallowed. Steel spacers are primarily used as spacers inside constructions,e.g. between two layers of reinforcement grids. Steel spacers are seldom used on a ground surface as this will cause corrosion problems.

Depending on the field of application, reinforcement spacers are dividedinto two main groups, foundation spacers and wall spacers. Foundation spacers are primarily used for positioning reinforcement in foundations/floors, while wall spacers are primarily used for positioningreinforcement in walls and vaults. One main difference is the type of underlying surfaces that they are intended to be used on.

Wall spacers are designed with thin legs and/or small feet. The formworksurface is generally hard and even, being a mould, which helps to preventthe spacer to tip over or to cut through the surface. When the formwork isremoved, the spacer feet are made visible. At a wall or vault not furtherprocessed, these feet will show in the wall surface, which is not desirable.Therefore wall spacers are designed with minimal feet and are also nearlyalways coloured like the surrounding concrete. Low visibility is a major requirement.

Foundation spacers are designed to be used when the formwork surfaceis classified as soft and/or uneven, such as a bedding of coarse sand,gravel, grit or other free-draining material or ground. The bearing surfaceof the spacer towards the ground has a relatively large area and often alarge diameter to aid the spacer to stand stable on the ground and not todig in to the ground or to tip over. Since foundation spacers primarily areused for floors and foundations, the spacer will point downward and willnot be visible. Foundation spacers thus have no aesthetic significance.The most important feature is a base plate having an area large enough not to punch the underlying surface.

Foundation spacers are divided into two subgroups due to differences indesign and the way they are used. One type is referred to as groundspacers. These typically have a large base plate and a smaller supportarea at the top. Due to the small support area, each spacer has to beplaced in an exact position to support any reinforcement. Ground spacersare seen as cheap but time consuming to work with. The other type islinear spacers. They are long and narrow. They support the reinforcement anywhere on its support area lengthwise and no exact positioning is thus required. Due to their length, often 2 meters, they shorten the working time of placing the spacers.

Both these types of foundation spacers are positioned manually on thesupporting ground, where ground spacers must be placed with an exactposition. Linear spacers are often provided in 2 meter lengths and are often placed next to each other lengthwise. They are relatively heavy.

US 6775954 describes a linear foundation spacer comprising three partsthat must be assembled before use. AU 2006100538 describes a linearwall spacer, having small feet adapted for the use as wall spacer. Aspecific base segment can be attached to the feet, such that the spacercan be used as a foundation spacer. US 4942714 describes a linear wallspacer. US 2005005564 describes a stackable foundation spacer havingan upper receiving section for fixedly retaining of a wire mesh.

DE 2821078 describes a circular wall spacer adapted for producingprefabricated wall modules, where the spacer can be placed randomly onthe mould. With a diameter larger than a single square in a reinforcementgrid, the spacer will always give support regardless its position. As mostwall spacers, the legs and feet are thin, which makes it unsuitable for useon soft underlying formwork surfaces like soil or insulation, such as EPS(extruded polystyrene). The small feet will sink down in the supportsurface from the weight of the reinforcement and the workers walkingupon it, giving an incorrect concrete cover. DE 2809430 also describes a similar wall spacer that can be positioned randomly.

There is thus room for an improved foundation spacer.

DISCLOSURE OF INVENTION An object of the invention is therefore to provide an improved stackablefoundation spacer for supporting a reinforcement grid. A further object ofthe invention is to provide a magazine for holding a p|ura|ity of suchfoundation spacers. A further object of the invention is to provide a feederfor distributing such foundation spacers.

The solution to the problem according to the invention is described in thecharacterizing part of claim 1 regarding the foundation spacer, in claim 9regarding the magazine, and in claim 11 regarding the feeder device. Theclaims contain embodiments and further other advantageous developments of the foundation spacer, the magazine and the feeder. ln a stackable foundation spacer adapted to support a reinforcement grid,where the foundation spacer comprises a lower bearing surface adaptedto be placed on a ground surface for the concrete, a first support surfaceadapted to support the reinforcement grid in a p|ura|ity of positions, and anouter circumferential side wall connecting the lower bearing surface withthe first support surface, the object of the invention is achieved in that theouter circumferential side wall is inclined outwards from the lower bearingsurface to the first support surface with an angle oi, and where the shapeof the first support surface is larger than a mesh in the reinforcement gridthat is to be supported.

By this first embodiment of the foundation spacer according to theinvention, the foundation spacer can be used to support reinforcementgrids in concrete constructions. Due to the size and shape of thefoundation spacer, the foundation spacers can be positioned randomlyand can still support the reinforcement grid. Since the positioning of thespacers is not critical, the laying out of spacers can be made in a time-saving manner. Further, the reinforcement grids must not be attached tothe foundation spacers, which also save time. The shape of the foundationspacer allows the spacers to be stacked in each other, which saves space during transportation and storage. The manual handling of the spacers isalso facilitated. ln an advantageous development of the invention, the foundation spacerfurther comprises a second upper support surface adapted to support thereinforcement grid, and an inner side wall connecting the lower bearingsurface with the second support surface, where the inner side wall isinclined inwards from the lower bearing surface to the second supportsurface with an angle ß. ln this way, the stability of the foundation spaceris improved. The angle of the inner side wall is preferably the same as theangle of the outer side wall. ln an advantageous development of the invention, the outer shape of thefoundation spacer is circular. By using a symmetric shape, the handling ofthe foundation spacer is simplified. ln an advantageous development of the invention, the outer shape of thefoundation spacer comprises three semi-circular parts having a dividingangle of 120 degrees. With such a shape, the stability of the foundationspacer is improved. Further, the amount of material required for thefoundation spacer is reduced. ln an advantageous development of the invention, the first support surfacecomprises an outwardly extending rim. ln this way, the stiffness of thefoundation spacer is improved. ln an advantageous development of the invention, the foundation spacercomprises at least one intermediate wall that interconnects the outer sidewall with the inner side wall. ln this way, the rigidity of the foundationspacer is improved. ln an advantageous development of the invention, the foundation spacercomprises a plurality of ridges on the inner side of the outer side walladapted to support the bearing surface of another foundation spacer when several foundation spacers are stacked. ln this way, the foundationspacers will not stick to each other when they are stacked, such that theycan easily be separated one by one when they are distributed. Further, awell-defined vertical interval for the stacked spacers is obtained. When thefoundation spacer comprises a second upper support surface and an innerwall, ridges with the same height may also be provided on the inner wall, in the direction towards the inner side of the outer side wall. ln an advantageous development of the invention, the foundation spacersare stacked in a magazine. ln this way, a plurality of foundation spacerscan be handled in an efficient way. ln an advantageous development of the invention, the magazine isadapted to be mounted to a release mechanism, such that one spacer atthe time can be released from the magazine. The release mechanism maye.g. comprise a release lever that can be operated by a user carrying themagazine. ln this way, a user can release foundation spacers at selected positions in an easy way. ln an advantageous development of the invention, a feeder device fordistributing stackable foundation spacers is provided. The feeder device isprovided with a release mechanism that can release foundation spacers.The release mechanism is in this example operated by the user, e.g. by arelease lever that is pressed each time a foundation spacer is to bereleased. The foundation spacers may be provided in a magazine in order to simplify the loading of the feeder ln an advantageous development of the invention, the feeder device isprovided with a semi-automatic release mechanism that can releasefoundation spacers with a predefined interval. The interval is preferably setby a user. ln one example, the interval is dependent on the rotation of awheel of the feeder device, i.e. the interval is dependent on the distance that the feeder device has travelled. The feeder device is preferably semi-automatic and is pulled or pushed manually by a user. ln an advantageous development of the invention, the feeder devicecomprises a second release mechanism disposed sideways from the firstrelease mechanism. ln this way, two rows of foundation spacers can bedistributed at the same time. Both foundation spacers may be released atthe same time with the same release mechanism. lt is also possible to letthe release position of each release mechanism differ by e.g. half thelength of the release interval, such that two equal rows with an offset areobtained. lt is also possible to let the predefined interval of each releasemechanism be set differently, such that two rows with differently spacedfoundation spacers are obtained. ln an advantageous development of the invention, the distance betweenthe two release mechanisms can be adjusted sideways such that thedistance between two rows of foundation spacers can be set. A suitableadjustment interval for the two release mechanisms is 0.7 to 1.3 meters,but depending on the size of the foundation spacers and the size of thereinforcement grid, other adjustment intervals may be used. ln an advantageous development of the invention, the feeder device isfully automatic and is self-propelled. ln this example, the feeder navigatesover the work site and positions foundation spacers at predefinedpositions. The navigation is preferably done by using either a localnavigation system positioned at the work site or a differential GPSnavigation system.

BRIEF DESCRIPTION OF DRAWINGS The invention will be described in greater detail in the following, withreference to the embodiments that are shown in the attached drawings, inwhich Fig. 1 shows a first embodiment of a foundation spacer according tothe invention, Fig. 2a shows a development of a foundation spacer according to theinvenüon, Fig. 2b shows a cut view of the foundation spacer according to Fig.2a, Fig.3 shows a plurality of foundation spacers according to theinvention supporting a reinforcement grid, Fig. 4 shows a stack of foundation spacers according to theinvenüon, Fig. 5 shows a magazine for foundation spacers according to theinvention, and Fig. 6 shows a semi-automatic feeder for foundation spacers according to the invention.l\/IODES FOR CARRYING OUT THE INVENTION The embodiments of the invention with further developments described inthe following are to be regarded only as examples and are in no way tolimit the scope of the protection provided by the patent claims.

Fig. 1 show a first embodiment of a foundation spacer according to theinvention adapted to support reinforcement grids. The foundation spacer 1comprises a first bearing surface 2 which is adapted to be placed on theground surface where the concrete is poured. This ground surface may berelatively soft and uneven, usually comprising a bedding of coarse sand,gravel, grit or other free-draining material. The first bearing surface of thefoundation spacer must thus be relatively large such that the spacer canstand stable and does not sink into the soft ground surface. The ground surface may also be expanded polystyrene (EPS), which is also relativelysoft such that a larger bearing surface is of advantage. The foundationspacer further comprises a first circumferential support surface 3 adaptedto support the reinforcement grid in a plurality of positions. The size of thespacer and thus the outer circumferential 10 of the upper support surfaceis such that it is larger than a mesh in the reinforcement grid. ln this way,the foundation spacer can always support the reinforcement grid,regardless of where the foundation spacer is positioned relative thereinforcement grid. An outer circumferential side wall 4 connects the firstbearing surface 2 with the first support surface 3. The outer circumferentialside wall 4 is inclined outwards from the first bearing surface to the first support surface with an angle oi.

The inclination angle of the side wall is preferably within a range of 1 - 30degrees, and more preferred 2 - 15 degrees. ln this way, the spacer iseasy to produce and several spacers can be stacked in each other. Asmaller angle gives a stiffer and stronger spacer. A larger angle mayreduce the required material usage.

The outwards inclination of the side wall allows the upper part of thefoundation spacer to be larger than the lower part of the foundationspacer. ln this way, the reinforcement grid can always be supported andmaterial is saved since the base of the foundation spacer can be madesmaller than a mesh of the reinforcement grid. A further advantage ofusing inclined side walls is that foundation spacers can be stacked in eachother, which additionally saves space during transportation and storage.The first bearing surface is provided with a plurality of openings that allowsless material to be used and that allows concrete to flow through duringthe concrete is poured in the mould. The centre of the spacer is hereprovided with a larger, central opening 7. Also the side walls are preferablyprovided with openings that let concrete pass through. 11 The upper support surface 3 is provided with a rim 5 that extendsoutwards from the side wall 4. The rim will in this example constitute theupper support surface. The outer circumference 10 of the rim thus sets thesize of the support surface. The size of the support surface is such that itis larger than a mesh in the reinforcement grid that is to be supported. Fora round foundation spacer, as shown in Fig. 1, the outer diameter of therim is thus larger than the mesh size of the reinforcement grid. When thefoundation spacer has another shape, the outer limit of the rim is such thatregardless of how the foundation spacer is positioned, it will be larger thana mesh of the reinforcement grid. By securing that the foundation spacercan always support the reinforcement grid without the spacer passingthrough a mesh, the foundation spacer can be distributed randomly on theground surface. An exact positioning is thus not required, which savestime. Further, a feeder can be used which distributes spacers semi-automatically or fully automatically, which allows even more time to be saved.

The rim will further increase the support area for the reinforcement gridand will also prevent the reinforcement grid to cut through the supportsurface and to damage the foundation spacer. The rim should extendaround the complete spacer without interruptions.

Since the upper support surface is flat and is situated in one plane anddoes not comprise any holding means for reinforcement bars, thefoundation spacer is mainly intended for supporting reinforcement grids. ltis of course possible to use it for support of other types of suitablereinforcement structures as well. The spacer can be randomly placed andwill still support reinforcement grids. The foundation spacer is adapted tobe used for repairing, renovating and for new constructions of anyfoundations/ground plates where reinforcement is used, and needs to beelevated from the ground, formwork or other surface regardless of material. 12 Additionally, the foundation spacer can also be used in other ways, forexample between two layers of grids within a foundation or between twolayers of grids within a wall element. The foundation spacer is suitableboth for manual distribution, where the foundation spacers are placed inposition one by one by a user, and for semi-automatic or fully automaticdistribution. When they are placed manually, a stack of foundation spacerscan easily be carried by the user, either with or without a specific magazine.

The size and design of the foundation spacer makes it possible to place itmore or less at random. There are no regulations that stipulate therequired number of spacers needed to support a given reinforcement grid.With the inventive foundation spacer, the number of foundation spacersand the exact position of each spacer is not important, since thereinforcement grid is always supported by each spacer. The design andgeometry for a spacer may vary, but in order to provide the requiredfunctionality and to minimize the used material of the spacer, there are afew important aspects of the invention. To allow a plurality of spacers to bestacked, the outer side wall must be inclined. By using an outwardinclination, material is saved since the lower bearing surface can be madesmaller than the support surface. The upper support surface determinesthe size of the foundation spacer depending on the size of the meshes inthe reinforcement grid that is to be supported.

Further, it is of advantage to provide one or more interconnecting wallsinside the spacer in order to increase the strength and stability of thefoundation spacer, where the interconnecting walls do not prevent thefoundation spacers to be stacked. ln Fig. 2a, a development of the foundation spacer is shown, and in Fig.2b, a cut section of the foundation spacer of Fig. 2a is shown. Fig. 3shows a plurality of foundation spacers supporting a reinforcement grid. lnthis example, the outer shape comprises three semi-circular parts divided 13 with an angle of 120 degrees. The outer side wall is still inclined outwardswith an angle oi. The shape slightly resembles a clover leaf shape. Othershapes are of course also possible, as long as the shape is larger than amesh in the reinforcement grid that is to be supported. ln one example, asshown in Fig. 3, the foundation spacer is intended for a reinforcement grid20 with a mesh size 21 of 20 cm. The outer shape of the support surfaceis thus larger than a square of 20*20 cm. ln this way, the foundationspacer will always be able to support the reinforcement grid, regardless ofhow the grid is positioned on the spacer. The reinforcement grid will not beable to fall down due to a misaligned spacer. As can be seen in Fig. 3, afoundation spacer will always support the reinforcement grid in severalpositions, the reinforcement grid and the foundation spacer will alwayshave at least four contact points, regardless of the relationship betweenthe position of a foundation spacer and the reinforcement grid.

The foundation spacer is in this example provided with a second supportsurface 6 positioned in the centre of the spacer. The second supportsurface is connected with the bearing surface 2 via a circumferential innerside wall 11, which is inclined inwards with an angle ß. The angle ß maybe the same as angle oi or may be larger or smaller. Since the inner sidewall is inclined inwards, from the bearing surface to the second supportsurface, it is possible to stack spacers in each other. The second supportsurface helps to stabilize the foundation spacer and provides a furthersupport surface, such that the weight of the reinforcement grid isdistributed on more contact points.

The inner side wall and the outer side wall are in this example alsoconnected with arched intermediate reinforcement walls 8 which providesfurther stiffness to the spacer while still being stackable. The secondsupport surface may be provided with a rim extending inwards. Thebearing surface 2 is in the shown example provided with a plurality ofopenings. The openings are provided to save material and to allow 14 Concrete to pass through. The number and size of the openings dependon the total bearing surface area wanted for a given ground surface inorder to prevent the foundation spacers to sink into the ground surface.The shown spacer is provided with three larger openings 9 and several smaller openings.

The inner side of the outer side wall may also be provided with smallridges 12 which are adapted to facilitate the stacking of spacers. Theheight of the ridges are such that the bearing surface of another spacerwill stand on the ridges when stacked, which prevents the spacers to stickto each other when they are pushed together. This makes it easier to partthe stack of spacers. The ridges further define the spacing in height, i.e.vertical interval, between the spacers. A well-defined vertical interval isadvantageous in that it simplifies the feeding of stacked spacers, e.g. froma dedicated magazine. When the foundation spacer comprises a secondupper support surface and an inner wall, ridges with the same height mayalso be provided on the inner wall, in the direction towards the inner sideof the outer side wall.

The foundation spacers can be distributed by hand by a user. Since thespacers can be placed randomly and must not be positioned exactly, theyare time efficient and easy to use. Compared with linear spacers, which isthe currently fastest working method for laying foundation spacers, thetime for manually laying the inventive foundation spacer can be reducedconsiderably, and by using a semi-automated feeder the work time may be reduced even more.

Fig. 4 shows a stack 13 of foundation spacers 1. A stacked pile of spacerssaves space during transportation and storage. The spacers arepreferably stacked in a specific magazine, as shown in Fig. 5. The shownmagazine 14 is adapted to hold a stack 13 of foundation spacers. Thefoundation spacers may either be sold and transported in the magazine, ormay be placed in the magazine at the work site. The magazine may thus be made from e.g. plastic, cardboard, corrugated fibreboard or even metal,depending on the intended use. lt is e.g. possible to use the magazines ina kind of replacement system, where the magazines are filled at a fillingstation and brought to the work site where the foundation spacers aredistributed on the ground surface. The magazines are then returned to thefilling station for refilling. ln this way, a cost-effective delivery system isobtained. The magazine can further be mounted to a release mechanism15 which is adapted to release one foundation spacer at the time from thestack of spacers. The release of a foundation spacer can e.g. be done byhand by an operator using a lever 16. ln this way, the user can walkaround with the magazine and release foundation spacers in theappropriate positions. Since there are no regulations stipulating the exactspacing of the foundation spacers, it is often the experience of the userthat decides where the spacers are positioned. By using this type ofrelease mechanism, it can be secured that a reinforcement grid receives appropriate support.

Fig. 6 shows an example of a feeder 22 for stackable foundation spacers.The shown feeder 22 is a semi-automatic feeder which is intended to beoperated by a user. The feeder resembles a wheeled trolley and isprovided with a release mechanism 23. The release mechanism 23 mayconsist of the release mechanism 15 mounted on the feeder or may beanother type of release mechanism. The user pulls or pushes the feederby the handle and the feeder rolls on wheels 28 and releases a spacer ata predetermined interval, such that the spacers are positioned with apredetermined spacing. The distance between the release positions of thefeeder can be set with a dial or the like. ln the shown example, the feederis provided with two release mechanisms, one on each side of the feeder.The distance between the release mechanisms can be adjusted such thatthe sideway spacing of the foundation spacers can be set. A suitabledistance for one type of reinforcement grid is in the interval of 0.7 - 1.3meters. The stacked spacers 13 are placed in a holder 25 of the feeder 16 from above. The spacers may be loaded into the holder from a magazine.lt is also possible to use a magazine as a holder. The spacers arereleased downwards from the release mechanism. The feeder may havetwo or more wheels, depending on the intended use. The shown feedercomprises four wheels, but for a manually pulled feeder, two wheels aresufficient. The shown feeder is also provided with a storage area 26,where additional stacks of spacers can be stored. The spacers are in theshown example released by pulling a lever 27. lt would also be possible toprovide the feeder with several release mechanisms on each side of thefeeder, such that one release mechanism can continue to distributefoundation spacers when a first release mechanism is empty. ln this way,the reloading of the feeder is simplified.

The release mechanism is in one example connected to the wheels 28 ofthe feeder such that the distance between the release positions can easilybe set. lt is possible to use a mechanic counter directly connected to awheel, e.g. an axially movable tap that hits a lever on the releasemechanism, or to use an electronic rotation sensor in order to obtain thedesired distance. After the predetermined distance, the feeder drops a spacer to the ground.

One advantage of a feeder is that it reduces the working time for layingspacers. A further advantage is that it improves the working environmentfor the user. Normally, the user has to carry all weight and has to benddown each time a spacer is placed. With a feeder, the user can walkupright and must not carry all the weight. lt is also possible to let the feeder be fully automatic, even though a semi-automatic feeder is probably more cost-efficient and saves a lot of time. lnthis case, the feeder is self propelled and can be programmed to follow apredefined path, such that spacers can be positioned at predeterminedpositions at a larger area automatically. The guiding of the automaticfeeder can be governed by e.g. by a laser or by a navigation system, such 17 as a differentiated GPS system. With a guiding system, it is also possibleto let the feeder return to a filling station when the feeder is empty. ln thisway, the feeder can be used on very large areas and possibly unattendedover night. lt would also be possible to let the feeder follow a predefined path withoutan external guiding system, by measuring the rotations of the wheels andusing this information to follow the path. Such a simple feeder guidesystem would be suitable for well-packed grounds since it cannotcompensate for slippage of the wheels.

One way of programming an automatic feeder is to import a constructiondrawing into the control system of the feeder. The control systemcalculates where to place the spacers and when ready, the user can pushthe start button and the feeder starts placing the spacers at thepredetermined positions.

The invention is not to be regarded as being limited to the embodimentsdescribed above, a number of additional variants and modifications beingpossible within the scope of the subsequent patent claims. The foundationspacer may have any size and may be made from any suitable material.

Other shapes are also possible. 18 REFERENCE SIGNS ïLF? ïLïLïL ïLJ? ïL.UF ïL9? mF? mmmm:EPPÉVTT m.UF m9? mE' m9? Foundation spacerLower bearing surfaceFirst support surfaceSide wall Upper rim Second support surfaceCentral openingArched wall Lower opening Outer circumferencelnner side wall Ridge Stack of foundation spacersI\/|agazine Release mechanismLever Reinforcement gridl\/lesh Feeder Release mechanismHandle Holder Storage area Lever Wheel

Claims (1)

1. . Stackable foundation spacer (1) adapted to support a reinforcement grid (20), where the foundation spacer (1) comprises a lower bearingsurface (2) adapted to be placed on a ground surface for the concrete,a first support surface (3) adapted to support the reinforcement grid ina plurality of positions, and an outer circumferential side wall (4)connecting the lower bearing surface (2) with the first support surface(3), c h a r a c t e r i z e d i n that the outer circumferential side wall(4) is inclined outvvards from the lower bearing surface (2) to the firstsupport surface (3) with an angle or, and where the shape of the firstsupport surface (3) is larger than a mesh (21) in the reinforcement grid(20) that is to be supported. .Stackable foundation spacer according to claim 1, c h a r a c t e r i z e d i n that the foundation spacer furthercomprises a second support surface (6) adapted to support thereinforcement grid, and an inner side wall (11) connecting the lowerbearing surface (2) with the second support surface (6), where theinner side wall (11) is inclined inwards from the lower bearing surface(2) to the second support surface (6) with an angle ß. .Stackable foundation spacer according to claim 1 or 2, characterized in thattheanglecrisequaltotheangleß. . Stackable foundation spacer according to any of claims 1 to 3, characterized in that the outer shape of the foundation spacer is circular. _ Stackable foundation spacer according to any of claims 1 to 3, c h a ra cte r i ze d in that the outer shape of the foundationspacer comprises three semi-circular parts having a dividing angle of120 degrees. . Stackable foundation spacer according to any of the preceding claims, c h a r a c t e r i z e d i n that the first support surface comprises an outwardly extending rim (5). . Stackable foundation spacer according to any of claims 2 to 6, c h a ra cte r i z e d in that the foundation spacer comprises atleast one intermediate wall (8) that interconnects the outer side wall(4) with the inner side wall (11). . Stackable foundation spacer according to any of the preceding claims, c h a ra cte r i ze d in that the foundation spacer comprises aplurality of ridges (12) on the inner side of the outer side wall (4)adapted to support the bearing surface (2) of another foundation spacer when several foundation spacers are stacked. _ Magazine (14), adapted for holding a plurality of stackable foundation spacer according to any of the preceding claims. 10.Magazine according to claim 9, c h a ra cte r i z e d in that the magazine comprises a release mechanism (15). 11.Feeder device (22) adapted to distribute stackable foundation spacers (1) according to any of claims 1 to 8, ch a racte rized in thatthe feeder comprises at least two wheels (28), a first releasemechanism (23) for releasing one foundation spacer (1 ) at the timeand a holder adapted to hold a plurality of stackable foundationspacers (1). 12.Feeder device according to claim 11, c h a r a c t e r i z e d in that the release mechanism is operated by hand. 13.Feeder device according to claim 11, c h a ra cte r i z e d in that the release mechanism (23) is adjustable such that the release interval between two foundation spacers can be set. 14.Feeder device according to claim 12 or 13, c h a ra c t e r i z e d inthat the release mechanism (23) is controlled in dependency of the rotation of a wheel (28). 15.Feeder device according to claim 11 to 14, c h a r a cte r i z e d inthat the feeder device comprises a handle (24) and is adapted to be operated by a user. 16.Feeder device according to claim 11 to 15, c h a ra c t e r i z e d in that the feeder device comprises a second release mechanism (23). 17.Feeder device according to claim 16, c h a r a c t e r i z e d i n thatthe distance between the first and the second release mechanism isadjustable. 18.Feeder device according to claim 16 or 17, c h a r a c t e r i z e d inthat the release interval of the first and the second release mechanism is the same.