The present invention relates to screeding systems for the finishing of concrete panels and floors and, in particular, to a screed support system which incorporates an adjustable height, non-recoverable two part chair which supports a recoverable screed rail used to level the concrete panels or floors or to hold a threaded insert.

BACKGROUND ART Screeding systems are used when laying concrete panels and floors to obtain flat surfaces. One of the most usual ways of screeding the concrete includes the use of having a number of screed rails supported by holders which are driven through a damp proof sheet and into a compacted base material underneath the concrete. The holders are driven through the damp proof sheet to provide stability when screeding. One disadvantage with such screeding systems is that the damp proof sheeting is punctured.

Such a screeding system also includes a complex method of attachment of the screed rails to the screed rail holders. This means that it is time consuming when the screed rails are to be moved for their next application if the concrete panel or floor is large in width.

OBJECT OF THE INVENTION

WO91/16514 (GRAPE J-E) describes an apparatus for facilitating the positioning of horizontally arranged reinforcing irons in moulds for vertically arranging building elements of concrete or the like. The apparatus has a pair of hook formed devices which face each other and which are positioned on a bar. At least one of the hooks can be adjusted to change the distance between the two hooks.

It is an object of the present invention to provide an improved support apparatus for screeding system which incorporates an adjustable height, non recoverable, two part chair which supports a recoverable screed rail.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is disclosed a support apparatus comprising a body having a substantially flat base, said body being adjustable in height and having a support means which is positioned adjacent the top of said body and is able to be used to support a support rail of a concrete screeding system above said body.

BRIEF DESCRIPTION OF THE DRAWINGS Some embodiments of the present invention will now be described with reference to the drawings in which; Fig. 1 is an exploded perspective view of a support apparatus of a first embodiment,

Fig. 2 is a perspective view of an upper tubular section of the support apparatus of Fig. 1, the upper tubular portion being used to support steel reinforcement bars,

Fig. 3 is a schematic side view of the upper tubular portion of Fig. 1 illustrated

having a cradle at both its ends,

Fig. 4 is an exploded perspective view of a support apparatus of a second embodiment,

Fig. 5 is a detailed view of a pin which is used in the apparatus of Fig. 4, and 5 Fig. 6 is a perspective view of a screeding system using the support appartus of

Fig. 1.

BEST MODE OF CARRYING OUT THE INVENTION

The apparatus 1 of the first embodiment includes a base support 2 for an adjustable height body 3. The base support 2 includes a flat annular ring 4 which serves as the o base of the apparatus 1. The base support 2 also includes a number of ribs 5 which connect between a pedestal 6 and the annular ring 4. The pedestal 6 supports the body

3.

The body 3 includes two tubular parts, a first tubular part 7 which is secured to the pedestal 6. The first tubular part 7 has a pair of notched helical inclined surfaces 8 in 5 which the notches 9 on opposite sides of the tubular part 7 are on the same level.

A second tubular part 10 is telescopically received within the first tubular part 7 and has a pair of oppositely positioned locating pins 11 which are receivable within the plurality of notches 9. The height of the body 2 can be adjusted by positioning the locating pins 11 in a different pair of notches 9. The pins 11 can have knobs (not 0 illustrated) at their ends to prevent the pins 11 inadvertently slipping out of the respective notch 9 when so positioned.

In the embodiment illustrated in Fig. 1, at the top of the second tubular part 10 is a pair of oppositely positioned cradles 12. The cradles 12 are used to seat a screed rail 15 which is used in turn to position with the aid of another screed rail 15, a vibrating screed 5 16 which is used to screed the surface of concrete panels or floors. A number of the apparatus 1 are used to hold the screed rails which support the vibrating screed. The locating pins 11 are positioned at an angular distance from the axis of the screed rail to prevent the screed rail fouling the second tubular part 10, as the tubular part 10 is rotated and moved up and down the inclined surface 8. The annular ring 4 of the base support 2 enables the apparatus 1 to be placed on a polythene damp proof sheeting (not illustrated) without puncturing the membrane of the sheeting. The adjustability in height of the body 3 allows the apparatus 1 to be used for a number of different height applications. In the case where the height has to be adjusted after the screed rails are in position, adjustment of the apparatus 1 can be 5 achieved by holding the second tubular part 10 with the screed rails in position and by rotating the base support 2 of the apparatus 1 in the appropriate direction. This adjustment can be achieved without removing the screed rails from the cradle 12. A clip (not illustrated) which can be used to prevent the screed rail vibrating out of the screed rail cradle 12 can be added to the apparatus 1 if required.

Once the concrete screeding has been completed, the screed rails can be easily moved to their next position for the continuation of the concrete pour. The apparatus 1 remains within the setting concrete. It is noted that the notches 9 in the helical inclined surfaces 8 provide a positive seating for the locating pins 11. This arrangement ensures that there is no tendency to creep downwards when the vibrating screed is placed on the screed rail.

• As illustrated in Fig. 3, the second tubular part 10a can have a pair of cradles 12a located at both its ends. The locating pins 11a can be offset from the centre of the second tubular part 10a at a distance equal to half the incremental step x (Fig. 1) of the notches 9 of the inclined surfaces 8. This allows an increment of half the step distance by reversal of the second tubular part 10a.

In a variation of the embodiment described above, in a second tubular part 20 (Fig. 2) the cradle 12 can be replaced by four evenly spaced cradles 22 which are used to support steel reinforcement bars (not illustrated). The pins 21 remain the same. This variation of the apparatus has the function of conventional bar chairs. The adjustment in the height of the body 3 enables the apparatus 1 to be used for a multiplicity of different heights. The apparatus 1 can be fitted with clips (not illustrated) which are used to retain the reinforcement bars if necessary.

In a second embodiment of the invention (Figs. 4 and 5), an apparatus 31 includes a base support 32 which supports an upper tubular body 33. The apparatus 31 is similar to the first described embodiment in that it has an annular ring 34, and is shaped as a conventional bar chair with a number of ribs 35. The apparatus 31 includes four mounting pins 36 which are used to engage with holes 37 of a retaining plate 38. The retaining plate 38 has a central boss 39 which has an external thread thereon in this particular embodiment. Naturally, the central boss 39 does not have to be threaded but can have another type of fastener. The central boss 39 is used to retain an internally threaded insert 40 which is suspended from the retaining plate 39.

The locating pins 36 in this embodiment include barbs 41 to ensure that the retaining plate 38 is fixed to the pins 36. Naturally, other ways of retaining the retaining plate 38 can be used.

If the threaded insert 40 which is suspended is metallic the apparatus 31 which can be made of plastics material can ensure electrical and mechanical isolation of the suspended components within the concrete panel and this can be used to eliminate possible corrosion paths. The apparatus 31 as illustrated in Fig. 4 is illustrated with supports 42 which ensure that the annular ring 34 is not visible where it is undesirable to have a flat plastic material showing on the exposed concrete surface.

One use for the device of the second embodiment of Figs. 4 and 5 is to enable the base of the insert 40 to contact one side of the concrete panel whilst the plate 38 is flush

with the other side of the panel. After the concrete has set, the plate 38 can be unscrewed and thereby reveal a through passage for electric cables, for example, which can pass through the insert 40 and the space previously occupied by the boss 39.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.