Formwork For Use In Supporting Shuttering

Abstract

Formwork for supporting shuttering panels for forming concrete floors and the like, comprising vertical props, between the heads of which extend shuttering supporting beams, the beams and heads having upstanding edge flanges for engaging with dependent projections on the ends of shuttering supporting transoms which extend between the prop heads and/or the beams.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to formwork for use in supporting shuttering panels for forming concrete and like floors, ceilings and roofs, which formwork is of the kind, herein called the kind specified, which comprises a number of vertically disposed beam supporting props, the upper end portion of each of which is provided with a beam supporting head, a plurality of mutually parallel beams for supporting the shuttering panels, which beams extend horizontally between the upper end portions of horizontally adjacent props, with opposite ends of the beams supported on the supporting heads of such props, the prop supported beams having panel engaging faces at their upper sides, and being provided with means for carrying from the beams the ends of transoms which extend between adjacent parallel beams transversely of the length thereof to provide additional support for the shuttering panels at positions intermediate the beams.

2. Description of the Prior Art

Hitherto, as far as we are aware, it has been the practice for the transom supporting means on the beams to be in the form of projections fixed to the beams at predetermined intervals along the length of the beams and engageable within openings provided in the ends of the transoms. Such an arrangement is open to the objection that the transoms can only be located at those particular positions along the length of the beams at which the projections are provided.

The principal object of the invention is to provide an improved arrangement in which the transoms can readily be supported at any desired position in relation to the beams while extending transversely of the length of the beams, thus permitting of the formwork being readily assembled in the optimum manner to meet the requirements of the particular site at which it is being utilised.

SUMMARY OF THE INVENTION

Formwork according to this invention is characterised in that the ends of both the beams and the transoms are provided with dependent projections which overlap the inner faces of upstanding connecting flanges provided both on opposite lateral edges of the beam supporting heads and of the beams themselves, with the connecting flanges on the lateral edges of each beam extending along the length thereof in alignment with connecting flanges on those prop heads which support the ends of such beam, the arrangement permitting of the same transom extending between, and being carried by, either a pair of prop heads, or a pair of mutually parallel beams, the ends of which are supported from said heads, with the transom then extending between the two beams at any desired position along the length thereof and with the transom ends being located by their dependent projections overlapping the inner faces of the upstanding flanges of the prop heads or beams respectively, with the upper face of the transom at the same horizontal level as the panel engaging face of the beam to provide a flush support for the horizontal shuttering panels.

The advantages of formwork according to this invention are :-

a. Insofar as opposite ends of a transom can in accordance with this invention be carried by a pair of the prop heads, or by a pair of parallel beams supported by such prop heads, necessarily the transoms can always be located in the optimum position, for example, on opposite sides of columns forming part of the building structure, and extending vertically through the spaces between adjacent parallel beams.

b. The transoms when in situ can be adjusted if required longitudinally of the beams.

c. The same type of support is provided by the aforesaid prop heads for the ends of the transoms as for the ends of the beams. Thus not only can the ends of beams or transoms be supported with equal facility from the prop heads, but the connecting means on the ends of the transoms is engageable with equal facility with the beams or the prop heads.

d. No packing is necessary between the shuttering panels and the adjacent faces of the beams or transoms, a feature of especial importance where the shuttering panels take the form of flat, e.g. plywood or other laminate sheet material.

The foregoing feature of this invention is preferably achieved by forming the beams to top-hat shape in cross section, with the flanges having upstanding edge flanges to provide grooves extending continuously along each side of the beams intermediate the ends thereof, which grooves receive the dependent projections at the ends of the transoms, the arrangement being such that each projection is located between an upstanding edge flange and the adjacent side of a beam so as to be positively located in a direction perpendicular to the beam length.

Where it is desired to minimise the capital cost of the formwork, the beam supporting heads of the props would be fixed against downward movement relative to the upper end portion of the associated props as by forming them as simple capping plates spaced below the shuttering panels.

Preferably, however, the props are provided with means for lowering their respective beam supporting heads relative to the props, the arrangement permitting of the beams and transoms being lowered at one and the same operation by the lowering merely of the prop beam supporting heads to effect removal of the beams and transoms after the concrete has sufficiently set as to allow this.

In such preferred arrangement, the props would desirably be provided at their upper extremities with concrete supporting caps, with provision for lowering the beam supporting heads relative to the caps to provide local support for the concrete at the positions of the props during its final setting after the beams and transoms have been removed.

In each of the two foregoing preferred arrangements just described, advantageously the means for lowering the beam supporting heads relative to the props comprise means arranged to effect progressive initial lowering of the heads with these still held against vertical downward movement relative to their respective props, and then to allow the heads to be slidden axially downwardly through a limited distance relative to their respective props to facilitate rapid removal of the beams and transoms.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the accompanying drawings, wherein :-

FIG. 1 is a perspective view of part of one preferred form of formwork for use in forming a concrete floor in accordance with this invention.

FIG. 2 is a cross sectional view on the line 2 -- 2 of FIG. 1 depicting in cross section one of the beams and showing its connection to an end of a transom.

FIG. 3 is a plan view of part of the construction depicted in FIG. 1.

FIG. 4 is a sectional view on the lines 4 -- 4 of FIG. 3.

FIG. 5 is an elevational view looking in the direction of the arrow 5 of FIG. 4.

FIG. 6 is a cross sectional view on the line 6 -- 6 of FIG. 5.

FIG. 7 is a view similar to FIG. 1 showing a modification.

FIG. 8 is a part sectional side elevation of the upper end portion of one of the props, depicting a modified form of beam supporting head.

FIG. 9 is a view similar to FIG. 6, but depicting a further modified form of beam supporting head.

FIGS. 10 and 11 are cross sectional views on the lines 10 -- 10 and 11 -- 11 respectively of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT.

Referring firstly to FIGS. 1 to 6 of the drawings, and initially to FIG. 1, the formwork there depicted comprises a number of horizontally extending shuttering panel carrying beams 10 formed in strip steel or other suitable strip material and of top-hat form in cross section. Thus each beam 10, as shown in FIG. 2, comprises an upper horizontal web 10a, a pair of dependent sides 10b having at their lower edges outwardly horizontally extending flanges 10c terminating in upstanding connecting edge flanges 10d, each spaced from the adjacent side 10b of the beam to provide therebetween a flange receiving groove 10e.

The formwork further comprises a number of horizontally extending transoms 11 also formed in strip steel or other suitable strip material, and of inverted rectangular channel form in cross section so as to embody an upper horizontal web 11a, a pair of dependent sides 11b having at their lower edges inturned stiffening flanges 11c.

The upper faces of the beam and transom webs 10a, 11a serve to support and engage with shuttering panels 12 which may be formed of plywood or other suitable shuttering panel forming material.

At least the majority of the beams 10 are intended to extend between and be supported from the upper end portions 13 of vertically disposed extensible props 14 spaced horizontally apart in rows so that the beams 10 can be supported in spaced mutually parallel relationship.

The upper end portion 13 of each prop 14 carries a beam supporting head 15 in the form of a square horizontally disposed plate, the lateral edges of which are provided with upstanding connecting flanges 16, with the two flanges at each pair of opposite edges of the head mutually parallel and spaced apart by a distance the same as the distance between the two upstanding connecting edge flanges 10d at opposite sides of the beams 10.

The prop heads 15 may also support the ends of the transoms 11, and each end of both the beams 10 and transoms 11 is provided with a dependent projection in the form of a dependent flange 17 formed integrally with the lower edge of the web 18a of a horizontally disposed channel shaped bracket 18, the arms 18b of which are secured to the outer faces of the adjacent sides 10b, 11b of the beam or transom respectively.

The dependent flanges 17 at the ends of the beams 10 and transoms 11 are adapted to overlap and engage with the inner faces of the upstanding connecting flanges 16 on the prop heads 15, thereby connecting and locating the ends of the beams and transoms in relation to the props 14 and in a position in which, as shown in FIG. 3, each of the two upstanding edge flanges 10d of a beam 10 so connected to one of the four head flanges 16 is aligned with one of two other and mutually parallel head flanges 16 of such head 15.

Also, the dependent flanges 17 at the ends of the transoms are adapted to overlap with and engage with the inner faces of the upstanding beam edge flanges 10d, i.e. to extend within the grooves 10e.

Thus the two ends of each transom can, in precisely the same manner be supported and located either by the connecting edge flanges 10d of a pair of mutually adjacent parallel beams, or by the connecting edge flanges 16 aligned with such beam flanges of two mutually adjacent prop heads 15, and in a position in either case in which the transom extends perpendicularly transverse to the above mentioned two beams.

Insofar as the upstanding beam edge flanges 10d and the associated grooves 10e are continuous along the length of the beams 10, the transoms 11 can be disposed at any desired position between two mutually parallel adjacent beams, and adjusted along the length of the two beams when in engagement therewith if so desired.

Usually, as shown in FIG. 1, all of the beams 10 would extend in one direction in spaced apart mutually parallel relation, with the transoms 11 extending at right angles to the length of the beams, so that the shuttering panels 12 are supported by both beams and transoms, but if desired the panels may be supported entirely by the top-hat section beams, namely as shown in FIG. 1, by providing short beams 10A of length corresponding to that of the transoms 11 so as to extend between the heads 15 of two mutually adjacent props, and the edge flanges 10d of these short beams 10A are adapted to engage with and support dependent edge flanges, as already described, and provided at the ends of intermediate beams 10B similar to the beams 10.

The lower horizontal edges of the dependent flanges 17 at the ends of the beams and transoms are adapted to abut against the upper surface of the prop heads, as well as with the bases of the grooves 10e at the inner sides of the beam edge flanges 10d, the bases of which grooves would be at the same horizontal level as that of the upper sides of the prop heads 15, and this fact, together with the fact that the overall depth of these dependent flanges 17 in relation to the upper face of the beam and transom webs 10a, 11a, ensures that the upper faces of the beam and transom webs are always supported at the same horizontal level so as to provide a flush support for the shuttering panels 12.

As shown in FIGS. 3 and 4, the prop heads 15 are provided on their undersides along one pair of lateral edges with outrigger plates 19 of elongated form which project beyond the adjacent corners of the square shaped heads, the ends of which outrigger plates are bent up slightly at positions beyond the lateral confines of the beams to prevent these from tilting in a sideways direction during assembly, but it should be understood that this particular feature may be omitted if desired.

To facilitate the rapid dismantlement of the beams and transoms after the concrete has partially set, the heads 15 may, as best shown in FIGS. 5 and 6, be mounted for limited vertical sliding movement along the upper end portions 13 of the props 14, which end portions would then carry at their upper extremities shuttering supporting caps 20 which are adapted to provide local support for short pieces of shuttering panel when the beams and transoms are lowered by downward movement of the heads relative to the upper end portions 13 of the props.

For this purpose the head 15 is formed centrally with a hole to permit of the vertical movement of the head relative to the end portion 13, and vertically slidable along the latter is an annular flange 21 connected by upwardly and outwardly inclined webs 22 to the lateral edges of the head 15.

The underside of the flange 21 is in thrust engagement with the upper end of a sleeve 23 vertically rotatable about, and vertically slidable along, the length of the prop, the lower end of the sleeve being formed with a pair of inclined cam faces 24 which in one rotational position of the sleeve engage, as shown in FIG. 4, with opposite ends of a diametrically extending pin 25. The sleeve 23 is, however, formed with a pair of diametrically opposed axially extending pin end receiving recesses 26, the arrangement being such that the sleeve 23 can be turned through 90.degree. from the position depicted in FIG. 4, and in a direction which is anti-clockwise looking upwardly of the prop, so as by reason of the cam faces 24 bearing on the ends of the pin 25 progressively to lower the sleeve 23 until the recesses 26 thereof are in alignment with the ends of the pin 25, thus allowing the sleeve 23 to be slid downwardly by a distance corresponding substantially to its entire length, in which the upper ends of lateral openings 27 in the sleeve abut the ends of the pin 25, thus preventing further downward movement.

The arrangement enables the initial pressure between the shuttering panels carried by the beams and transoms consequential on the weight of the concrete to be relieved by the rotational movement of the sleeve 23, and afterwards by simultaneous lowering of all of the sleeves 23 of all of the beams 10 and transoms 11 carried thereon being simultaneously lowered as a whole to effect rapid release of the beams and transoms and shuttering panels thereon, while leaving the concrete locally supported by the caps 20 until the concrete has set sufficiently for the props 14 and their associated caps to be removed.

Provision is made for maintaining the heads 15 in a horizontal position despite eccentric vertical loading thereof having regard to the freedom of the heads to be slid down the upper end portions 13 of the props. This is an important constructional feature since without it, in the event of the vertical loading of the heads 15 being eccentric, the heads might tilt about a horizontal axis extending diametrically through the adjacent upper end portion 13 of the prop.

The foregoing provision comprises in part the annular flanges 21 which are in slidable engagement with the exterior of the prop end portions 13, and are spaced vertically below the heads 15.

In addition, however, the heads 15 are provided with guide means which engage with the end portion of the prop at least two positions spaced axially along the length of the prop end portion 13. These guide means in the arrangement depicted in FIGS. 4 to 6 comprise a cylindrical tube 28 (see FIG. 6) the exterior of which is in slidable engagement with the adjacent interior of the prop end portion 13, which is of the customary tubular configuration. The guide means provided by this tube 28 accordingly is in slidable engagement with the interior of the prop end portion 13 over the entire axial length of such tube.

Each prop end portion 13 is formed with a pair of axially extending diametrically opposed slots 29, the lower extremities of which accommodate the pin 25, with the slots extending to the upper extremity of the prop portion 13 and receiving a web portion 30 of the head 15 which extends diametrically through the two slots 29 between opposite sides of the flange 21 and has welded to its upper face the adjacent lower edge of the tube 28.

Upward movement of the head 15 relative to the prop end portion 13 is limited by the latter having welded around its tubular exterior a stop collar 31 adapted to abut against the upper face of flange 21.

The caps 20 may carry small square shaped shuttering portions 32 cut out of the main shuttering panels 12, but to avoid the necessity specially to shape the main shuttering panels 12 at these positions, the caps 20 may instead carry shuttering strips 33 of short length aligned with longer shuttering strips 34 of the same width secured to the centre portions of the beam webs 10a.

Alternatively, the centre portions of the beam webs 10a may be recessed upwardly by a distance corresponding to the thickness of the shuttering panels 12.

The arrangement in either case provides the beams 10 with locating shoulders 35 of depth corresponding to the thickness of the shuttering panels 12 for locating the latter against movement transversely of the beams having these locations.

The beam and transom webs may be formed with holes 36 for receiving suitable fastening members such as nails or small self-tapping screws, for fastening the shuttering panels in position, and the small shuttering panels 32, and strips 33 and 34, may similarly be secured to the caps 20 and beam web 10a respectively.

If desired, as shown in FIG. 1, some of the prop heads 15 may support cantilever fashion further short beams 10C of configuration otherwise similar to that of the beams 10, between the extremities of which cantilever beams may extend, supported therefrom in the above manner described, outrigger beams 10D which are identical in form to the beams 10.

The outer ends of these cantilever beams 10C are supported from the adjacent props 14 by struts 37, the lower ends of which have a wedge spigot connection to spigot receiving sockets 38 on the exterior of the prop 14 or prop extension 13.

All of the above described beams 10 may be reinforced against bending in the known manner by providing them on their undersides with bracing elements 39 of known form.

To permit of the underside of the floor being formed with one or more soffits, namely at the position depicted at 40 in FIG. 7 of the drawing, provision is made, as shown in this figure, for supporting some of the beams 10 at a horizontal level lower than that of the remaining beams, namely providing cross members 41 also of top-hat form in cross section so as to be adapted to support the ends of the lower level beams 10 in like manner to the beam 10A of the FIG. 1 arrangement.

These cross members 41 are, however, provided at each end with channel-shaped brackets adapted for wedging connection with sockets 38 carried from the props 14, between which the cross members 41 extend, the wedging connection being preferably of the particular form described in our prior U.S. Pat. specification No. 3,420,557.

The sockets 38 may be provided on the upper end portions 13 of the props, or on parts of the props 14 below these upper end portions.

As will be apparent from FIG. 7 of the drawings, the arrangement permits of some of the shuttering panels being disposed at a horizontal level lower than that of the other panels, with vertically extending panels on each side of the soffit. Otherwise the construction of FIG. 7 would be similar to that already described in reference to FIG. 1, except that there is no provision for progressive lowering of the cross members 41 and beams thereby supported.

Referring now to FIG. 8 of the drawings, there is here depicted a further form of guide means of a beam supporting head 15 for maintaining the latter horizontal despite eccentric loading. This comprises the provision at a position spaced vertically from the aforementioned annular flange 21 of a plate 42 formed centrally with a circular hole of diameter corresponding to the peripheral diameter of the cylindrical prop end portion 13, so that the edges 43 of the hole are, as in the case of the flange 21, in axially slidable engagement with the prop end portion 13. In addition, between the diametrically opposite sides of the apertured portion of the plate 42 extends a web portion 44 spaced vertically above the web portion 30 which, as in the case of the web portion 30, extends through the two slots 29 in the prop end portion 13, with the lateral edges of both web portions in slidable engagement with the vertical edges of the two slots 29.

Thus the two web portions 30, 44, together with the flange 21 and plate 42, provide guide means which engage with the upper end portion of the prop at two positions spaced axially along the length of the prop.

With this last described arrangement the stop collar 31 is arranged to abut the upper face of plate 42 to limit the upward movement of head 15.

In FIGS. 9 to 11 of the drawings there is depicted a further form of guide means for the beam supporting head 15. In this construction the aforementioned annular flange 21 is formed with an upwardly extending tube 45 which is in slidable engagement with the entire periphery of the cylindrical prop end portion 13. This tube 45 is formed at diametrically opposed positions corresponding to the two slots 29 with part circular axially extending portions 46 which engage slidably with the exterior of the prop end portion on horizontally opposite sides of its slots 29, and these portions 46 are formed with diametrically opposed axially extending lugs 47 which project within the slots 29 so as on their lateral edges to be in slidable engagement with the vertical edges of these slots. Thus again the head guide means engage with the prop end portion at positions corresponding to the flange 21, as well as at the upper ends of the lugs 47, in addition to so engaging at locations intermediate these two positions. In this construction upward movement of the head 15 is limited by the engagement of the upper edge of each part circular guide portion 46 with the underside of the aforementioned stop collar 31.

Preferably the upper end portion 13 of each prop 14 is formed as a unit adapted for detachable mounting on the upper end of the prop 14 so as to provide a removable extension thereto carrying the beam supporting head 15 and associated parts, including sleeve 23, as earlier described.

In both the FIG. 8 and FIGS. 9 to 11 modified constructions, the heads 15 are supported for downward movement relative to the prop portions 13 through sleeves 23 supported and operating as already described with reference to FIGS. 4 and 5 to effect progressive lowering of the beams and transoms.

Claims

I claim:

1. Formwork for use in supporting concrete-forming shuttering panels comprising

a. a plurality of horizontally spaced vertically disposed beam supporting props, each having at its upper end a beam supporting head with four lateral edges and a respective upstanding flange extending along each such edge.

b. a plurality of mutually parallel beams for supporting the shuttering panels and extending horizontally between the beam supporting heads of props, said beam having

i. at their upper sides a respective shuttering panel engaging face,

ii. at their opposite ends a respective dependant projection overlapping the upstanding flange of an adjacent one of said prop heads at the side of said flange remote from said beam, and

iii. along their lateral edges upstanding flanges disposed in alignment with said prop head upstanding flanges which are adjacent to said prop head upstanding flanges which the beam end dependant projections overlap, and

c. a plurality of transoms for additional supporting the shuttering panels and extending transversely to said beams, said transoms each having

i. at their upper sides a shuttering panel engaging face level with said shuttering panel engaging faces of said beams, and

ii. at their opposite ends a respective dependant projection overlapping the upstanding flange of either one of said beams or one of said prop heads in alignment therewith.

2. Formwork as claimed in claim 1, wherein said beams further comprise, at opposite lateral edges of said shuttering panel engaging faces thereof dependant sides, and at the lower edges of said dependant sides outwardly extending flanges terminating in said upstanding flanges thereof spaced from the adjacent dependant side of the beam to define a respective channel in which said transom end dependant projection can be received.

3. Formwork as claimed in claim 1, wherein said beam end dependant projections and said transom end dependant projections each comprise a respective flange extending transversely of the length of the beam or transom on which it is provided.

4. Formwork according to any of claim 1, characterised in that the props are provided with means for lowering their respective beam supporting heads relative to the props, the arrangement permitting of the beams and transoms being lowered at one and the same operation by the lowering merely of the prop supporting heads to effect removal of the beams and transoms after the concrete has sufficiently set as to allow this.

5. Formwork according to claim 4, characterised in that the props are provided at their upper extremities with concrete supporting caps with provision for lowering the beam supporting heads relative to the caps to provide local support for the concrete at the positions of the props during its final setting after the beams and transoms have been removed.

6. Formwork according to claim 4, characterised in that the means for lowering the beam supporting heads relative to the props comprise means arranged to effect progressive initial lowering of the heads with these still held against vertical downward sliding movement relative to their respective props and then to allow the heads to be slidden axially downwardly through a limited distance relative to their respective props to facilitate rapid removal of the beams and transoms.

7. Formwork according to claim 4, characterised in that each beam supporting head is provided with guide means which engages with a portion of the prop at at least two positions spaced axially along the length of the prop portion so as to maintain opposite lateral edges of each axially slidable beam supporting head at the same horizontal level during its downward axial movement relative to the prop irrespective of any eccentricity of the loading of the head from the beams.

8. Formwork according to claim 7, characterised in that the upper end portion of each prop comprises a tubular portion and the guide means comprises a tube in axially slidable engagement with the interior of said tubular portion of the prop, said guide means tube being carried on a web portion of the supporting head which extends transversely through a pair of axially extending slots formed in diametrically opposite sides of said tubular end portion of the prop.

9. Formwork according to claim 7, characterised in that the guide means of each beam supporting head comprises a pair of guide portions which extend annularly around the upper end portion of the prop at positions spaced axially thereof, each annular guide portion having its diametrically opposite sides joined by a transverse web portion which extends through an axially slotted part of the prop end portion in slidable engagement with the axially extending edges of the slot.

10. Formwork according to claim 7, characterised in that the upper end portion of each prop is of tubular form and embodies a pair of diametrically opposed axially extending slots, and the guide means of each beam supporting head comprise a tubular part in axially slidable engagement with the exterior of the prop end portion, and having a pair of axially extending lugs, the lateral edges of which are in axially slidable engagement with the vertical edges of said diametrically opposed slots.

11. Formwork according to claim 1, characterised in that the props are provided at a position below their beam supporting heads with additional means for supporting some of said beams at a horizontal level below that of the remaining beams so as to provide a support for shuttering for forming a dependent rib on the underside of the concrete floor, roof, or on the ceiling.

12. Formwork according to claim 1, characterised in that some of the beams comprise cantilever beams having a dependent prop head engaging projection at one end only, with means for supporting the other end of each cantilever beam from the associated prop, comprising a strut arranged to extend at an inclination to the vertical between the said other end of the cantilever beam, and additional supporting means at a position below the level of the prop heads.

13. Formwork according to claim 1, charterised in that the panel engaging faces at the upper sides of the beams are formed at the lateral portions of these upper sides with shuttering panel locating shoulders which extend longitudinally of the beams and are of a vertical depth corresponding to the thickness of the shuttering panels to be supported by the formwork.

14. Formwork according to claim 13, characterised in that the shuttering panel locating shoulders are provided by shuttering forming strips of width less than the upper sides of the beams and secured to said sides.

15. Formwork according to claim 1, characterised in that the upper sides of the beams and transoms are formed with holes for receiving shuttering panel fastening members.