GB2265654A

GB2265654A - Drop head

Info

Publication number: GB2265654A
Application number: GB9307018A
Authority: GB
Inventors: Gerhard Dingler
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-04-03
Filing date: 1993-04-02
Publication date: 1993-10-06
Anticipated expiration: 2013-04-02
Also published as: BE1007921A3; IT1262099B; DE4211136C2; SE9301066L; FR2689546B1; GB2265654B; FR2689546A1; NL9300514A; AT409648B; CZ56693A3; DE4211136A1; ATA61693A; SE9301066D0; GB9307018D0; ITUD930056A0; ITUD930056A1

Abstract

A drop head of a ceiling formwork has levers (33) connected pivotably to the supporting plate (14) and pivoting outwards as a result of their own weight and possessing locking projections (38). These engage in apertures (39) of engaging profiles (18, 19) on the formwork carriers (16, 17). The insertion of the engaging profiles (18, 19) is not impeded, since the locking projections (38) thereby shift aside. In contrast, separation necessitates a horizontal movement. If a formwork carrier (16, 17) therefore remains adhering to the concreted ceiling, the supporting plate (14) also continues to remain safely connected to the formwork carrier as a result of the interlock. An uncontrolled falling down of formwork carriers is therefore impossible, with the result that the risk of accidents is reduced. <IMAGE>

Description

2265654 is 1 SUPPORT DEVICE

The invention relates to a device for supporting ceiling formwork, particularly but not exclusively, according to the pre-characterising clause of Claim 1.

A device of this type has become known, for example, from DE 3,147,081 C2. The stay head is typically called a Mrop head", because the supporting plate, together with the formwork carriers supported on it, is lowered approximately 15 cm, in practice Mropped", after the setting of the concrete ceiling. The ceiling formwork is thereby freed from the concrete ceiling formed by it, to such an extent that the formwork parts can be dismantled. The construction of the ceiling formwork usually takes place "from above", that is to say where initially there is still no concrete ceiling and therefore access is free. Accordingly, there is the requirement of having the possibility of also placing formwork carriers or shuttering-board elements onto the supporting plate from above, thus determining the type of hook arrangement.

Thus, in known devices, there is the disadvantage that a formwork carrier can remain adhering to-the fresh concrete ceiling after the supporting plate hitherto supporting it has been 2 - 15 lowered. Such a formwork carrier can then come loose from the ceiling in an uncontrolled way and, in particular, cause personal injury.

The object of the invention is to provide a device of the relevant generic type which at least reduces substantially the risk of accidents.

This object is achieved by means of the characterising features of Claim 1.

The locking arrangement ensures that the supporting plate always remains coupled to the formwork carrier until both are deliberately separated from one another, that is to say either by resetting the locking device by hand or by drawing off the engaging profile in a horizontal direction from the supporting plate, which is not "prohibited" by the locking device and the hook arrangement. During the normal lowering of the supporting plate, these "permitted" conditions do not occur. The supporting plate therefore draws the formwork carrier actively away from the concrete ceiling or it remains at the top together with the formwork carrier adhering to the ceiling. At all events, there is no possibility that the formwork carrier will fall down in an uncontrolled manner. However, since the locking arrangement shifts aside when the engaging profile is being attached from above, is 3 assembly can be carried out without obstruction, as required.

Claims

The development according to Claim 2 prevents the engaging profile from unintentionally sliding laterally from the supporting plate. But this ensures, at the same time, that the second hook arrangement can also be disengaged by a lifting permitted by the locking arrangement. There is therefore no need to release the locking arrangement, which would be difficult in view of the conditions of space. The locking arrangement can, in principle, be designed in the manner of a lock latch on room doors, which directly allows engagement, but which blocks separation. A mechanism similar to the known pawl mechanism could be provided for drawing back the locking device. In the development according to Claim 4, the locking projection can be pushed back in the permitted horizontal direction solely as a result of a displacement movement of the engaging profile. It thereby slides out of the aperture in the otherwise smooth front wall. The embodiment according to Claim 6 provides an "elasticity" which does away with springs or the like which are susceptible to faults. 4 The stop device according to Claim 7 prevents the locking projection from being wedged together with the engaging profile, which could occur in an unfavourable pivoting position. In addition, the embodiment according to Claim 8 affords a highly stable support. According to Claim 9, unnecessary material of the lever is avoided radially outwards from the pivot axis, with the result that it is simpler to cause sufficient weight to act on the side of the lever which is located inwards from the pivot axis and which weight causes the locking projection to pivot outwards. The preferred embodiment according to Claim 11 takes account of most practical requirements, according to which two formwork carriers aligned with one another are suspended on one stay. Only in edge positions of the concrete ceiling does the stay form a termination and hold only one formwork carrier. Further embodiments of the invention emerge from the subclaims not previously discussed in particular, and from the following description of an exemplary embodiment, with reference to the drawing. In the drawing: Figure 1 shows a partially sectional side view of is a device according to the invention, Figure 2 shows a partially sectional view according to the plane 2-2 of Figure 1, Figure 3 shows an alternative locking version indicated diagrammatically. The stay head illustrated in the Figures consists of a flanged plate 10 with bores, not shown in any more detail, for the purpose of fastening to extension tubes, of a tubular portion 11 projecting perpendicularly from this and coaxial relative to a longitudinal axis 12 of a stay, of a square head plate 13 arranged at right angles thereto, and of a vertically displaceable supporting plate 14. The supporting plate 14 has a square basic shape, with hook-in webs 15 which project sideways on all four sides and are angled upwards and which are identical to one another. An engaging profile 18, 19 is respectively fastened to the end face of each of two formwork carriers 16, 17 arranged diametrically relative to the longitudinal axis 12 of the stay. Because the details correspond to one another, only the right-hand part of the Figures is first explained in more detail. The engaging profile 18 is designed as a hollow aluminium extruded profile, with a top side 20 which is 6 is aligned with the head plate 13 in the shuttering position shown, with an essentially smooth wall 21 (the bend is not of particular importance here) pointing towards the tubular portion 11, and with a downwardly pointing hook strip 22 which is supported on the horizontal and vertical regions of the hookin web 15. The engaging profile 18 consequently cannot be pulled away from the supporting plate 14 in a first direction 23 which extends horizontally and in the longitudinal direction of the formwork carrier 16. Such a movement would be possible only when the lower edge of the hook strip 22 is lifted above the upper edge of the hook-in web 15. A lift within a first distance of the height of the vertical region of the hook-in web 15 does not disengage this first hook arrangement. A stud 24 projects upwards from the hook-in web 15 and penetrates loosely into a bore 25 in the hook strip 22. The upper end face of the stud is located at a second distance higher than the horizontal bottom of the hook-in web 15 which second distance is smaller than the abovementioned first distance. In the position shown, the bore 25 forms with the stud 24 a second hook arrangement which blocks a horizontal sideways displacement of the engaging profile 18 in a second direction 26 (Figure 2) which 7 is oriented at right angles to the first direction 23. Two mutually parallel wall plates 27, 28, between which the tubular portion 11 is arranged with pay, project vertically upwards from the supporting plate 14. In Figure 1, the wall plate 28 is shown truncated, and at the other wall plate 27 the upper edge is represented by broken lines, since it is concealed by other parts. The two wall plates 27, 28 have, at their upper edges, a semicircular recess 29, into which engages a crosspin 30 which is fastened to the tubular portion 11 so as to cross the latter. The crosspin 30 thus acts as a vertical stop for fixing the maximum height of the supporting plate 14 and as a rotary guide, so that the supporting plate 14 can also be set exactly in relation to the head plate 13. The front edge of the engaging profile 18 can thus be adjacent to the head plate 13 almost without a gap. Underneath the crosspin 30, guide strips 31 are also welded to the tube casing and orient the rotary position of the head plate 13 even while it is being lifted. A horizontal pin 32 located laterally next to the tubular portion 11 is fastened between the wall plates 27, 28 and forms a pivot axis for a doublearmed lever 33. This has two side cheeks 34, 35 8 which are located in the vicinity of the wall plates 27, 28 and which extend approximately as far as the crosspin 30, without touching it, and are connected by means of an inner wall 36 following the curvature of the tubular portion 11. The side view of Figure 1 shows open-edged recesses in the side cheeks 34, 35, constituting bearing half-shells 37 which engage around the pin 32 only over approximately half its circumference. However, the lever 33 cannot slip off from the pin 32 towards the tubular portion 11, because its inner wall 36 prevents such a movement on account of its proximity to the tubular portion 11. The lever arm located underneath the pin 32 carries, at its lower end, a locking projection 38 which, as a result of the pivotable articulation of the lever 33, executes a movement essentially radial to the longitudinal axis 12 of the stay. A further pivoting in the anti-clockwise direction is prevented in that the lever arm located above the pin 32, that is to say the inner wall 36 extending there, comes to bear against the tubular portion 11. In contrast, an inward pivoting in the clockwise direction is possible to a limited extent on account of a bent shape of the inner wall 36 in the region of the lower lever arm. At the same time, as is evident, the material distribution of the lever 33 9 is selected so that it pivots out into the locking position shown as a result of its own weight. As illustrated, the wall 21 of the engaging profile 18 has an aperture 39, into which the locking projection 38 engages automatically. Its approximately horizontal underside is located at a third distance above a horizontally oriented locking face 40 of the engaging profile 18. In the example, this is the surface of a transverse rib 41, to which the aperture 39 extends. However, the locking face can also be formed by the lower edge of the aperture itself. Since the third distance is smaller than the first distance, but larger than the second distance, this results in the following effects: When the supporting plate 14 is freed in a known way by loosening the clamping ring 42 and the formwork carrier 16 adheres to the ceiling, the supporting plate 14 descends only over the third distance, because the locking projection 38 then rests on the locking face 40. The locking projection 38 is thereby subjected on the right laterally of the pin 32 to a vertical force component which generates a torque in the anti- clockwise direction in view of its tangential direction in relation to the pivot axis of the lever 33. Consequently, the upper region of the inner wall 36 comes with a blocking effect up against the tubular portion 11. A further alternative or additional blocking is brought about by a vertical rib 43 which is located on the lever 33 and which is attached underneath the locking projection 38. In particular, the outer edge of the rib 43 is pressed against the wall 21 of the engaging profile 18 as a result of the pivoting movement of the lever 33 and therefore attempts to push the engaging profile 18 in the first direction 23, this being blocked on account of the first hook arrangement 15/22. A further pivoting of the lever 33 is thus also blocked at the same time. In the above-described engagement position of the locking projection 38, the hook strip 22 remains caught behind thp vertical part of the hook-in web 15 and the engaging profile 18 thus remains secured on the supporting plate 14. Should the formwork carrier 16 then come loose from the ceiling, it continues to remain secured to the supporting plate 14 and falls down together with this only as far as the normal lowering stroke of the supporting plate 14, for example 15 cm,"allows. In order thereafter to remove the formwork carrier 16 in a controlled manner, it has to be lifted by the second distance, so that the hook strip 22 11 passes over the stud 24, this movement not being impeded by the locking projection 38. This state is illustrated by the example of the engaging profile 19, although it is incorrect insofar as the supporting plate 14 is shown in its upper shuttering position. In this slightly lifted position of the formwork carrier 17 (16), the engaging profile 19 (18) can be pushed to the side in the second direction 26. As a result of a sweptback design, the locking projection 38 is thereby urged out of the aperture 39, in that one of its lateral sliding edges 44 slides in a wedge-like manner on the lateral limiting edge 45 of the aperture 39. The insertion of the formwork carriers can take place in the opposite horizontal direction of movement, the respective sliding edge 44 sliding on the outer edge of the wall 21. As soon as the engaging profile then comes into the correct position, the locking projection 38 pivots into the aperture 39. However, the formwork carrier can also be inserted from above in a vertical movement, the hook strip 22 butting from above against the locking projection 38 which thereby shifts by pivoting inwards and does not impede the operation. In the foregoing exemplary embodiment, locking 12 arrangements are provided on two diametral sides of the supporting plate 14. This leaves sufficient room for the levers, so that these can be designed in terms of weight in such a way that they pivot outwards automatically. Two locking arrangements are also normally sufficient, because only two main formwork carriers in alignment with one another usually have to be supported. However, the locking arrangements can also be designed with more precision engineering, for example as spring catches 46, as indicated diagrammatically in Figure 3. But the lever version is better adapted to the rough conditions of use on site. As in DE 3,147,081 C2, the engaging profile 18 can also be a simple end plate, its straight downwardly projecting edge representing the "hook strip", for the angling shown in the exemplary embodiment has other advantages which are, however, unimportant in connection with the present invention. The expression "engaging profile" therefore represents all designs which occur on formwork carriers or formwork elements and which allow a hooking with the supporting plate. t 13 Claims:

1. Device for ceiling formwork, with a stay head which has a supporting plate which is vertically displaceable on a tubular portion in the direction of the longitudinal axis of the stay and on which at least one engaging profile of a formwork carrier can be supported, there being provided between the supporting plate and the engaging profile a first hook arrangement which allows the engaging profile to be placed onto the supporting plate from above, but which blocks a relative movement in a first horizontal direction extending in the longitud-inal direction of the formwork carrier and also radially relative to the longitudinal axis of the stay, the first hook arrangement being designed in such a way that it is still in mutual engagement when the engaging profile is lifted relative to the supporting plate within a first distance, characterised in that there is connected to the supporting plate (14) at least one locking arrangement (38) which blocks a lifting of the engaging profile (18, 19) relative to the supporting plate beyond the first distance, but which shifts aside elastically when the engaging profile is placed vertically onto the supporting plate.

14

2. Device according to Claim 1, characterised in that there is provided between the supporting plate (14) and the engaging profile (18, 19) a second hook arrangement (24, 25) which additionally blocks a horizontal relative movement in a second direction (26) extending at right angles to the first direction (23), the second hook arrangement being designed in such a way that it is disengaged when the engaging profile is lifted relative to the supporting plate over and beyond a second distance which is smaller than the first distance, and in that the locking arrangement (38) does not impede a lift over and beyond this second distance.

3. Device according to Claim 1 or 2, characterised in that the locking arrangement has a locking projection (38) which is mounted movably relative to the supporting plate (14) essentially horizontally in the first direction (23) and which, with the engaging profile (18, 19) attached, is held vertically above an essentially horizontally oriented locking face (40) of the engaging profile.

4. Device according to Claim 3, characterised in that the engaging profile (18) has a smooth wall (21) which faces the locking projection (38) and in which is provided an aperture (39), through which the locking projection, penetrating through the wall, passes over the locking face (40), and in that, as seen in the viewing direction of the longitudinal axis (12) of the stay, the locking projection has a shape swept back approximately triangularly in the first direction (23), to form lateral sliding edges (44) which, sliding on lateral limiting edges (45) of the aperture (39), urge the locking projection out of the aperture in a horizontal relative movement in a second direction (26) extending at right angles to the first direction (23).

5. Device according to Claim 1 or 3, characterised in that the locking arrangement comprises a lever (33) which is mounted pivotably relative to the supporting plate (14) and which has a locking projection (38) which is remote from its pivot axis (32) and which, with the engaging profile (18) attached, is held vertically above an essentially horizontally oriented locking face (40).

6. Device according to Claim 5, characterised in that the pivot axis (32) is oriented horizontally lat-erally next to the tubular portion (11) and is arranged vertically above the locking projection (38), the lever (33) being designed in such a way that the locking projection is urged away from the tubular portion (11) in the first direction (23) as 16 a result of the lever's own weight.

7. Device according to Claim 5, characterised in that, in the locking position of the lever (33), the locking projection (38) is arranged at a greater radial distance from the tubular portion (11) than the pivot axis (32) of the lever, and in that there is provided a stop device (36, 43) which prevents a substantial outward pivoting of the locking projection beyond the locking position.

8. Device according to Claim 7, characterised in that the lever (33) is designed as a two-armed lever, of which the lever arm located above its pivot axis (32) can be brought to bear against the tubular portion (11) and forms the stop device.

9. Device according to Claim 6, characterised in that the pivot axis is formed by a pin (32) arranged fixedly relative to the supporting plate (14), and in that the lever (33) surrounds the pin with open edged bearing half-shells (37) only.

10. Device according to Claim 9, characterised in that there project vertically upwards from the supporting plate (2) two wall plates (27, 28) which are essentially parallel to one another and between which the tubular portion (11) is arranged with play and between which the pin (32) is mounted.

11. Device according to Claim 10, characterised 17 is in that a pin (32) is mounted on each of the two sides in relation to the tubular portion (11), and in that two levers (33) are mounted in a mirrorsymmetrical arrangement on the latter, to form two locking arrangements oriented on diametral sides of the supporting plate (14).

12. A device for use in supporting a formwork member which is provided with an engagement profile, comprising an elongate portion and a support portion adapted to be displaceable on said elongate portion in the direction of the longitudinal axis thereof, said support portion comprising support means and a displaceable engagement means mounted on said support portion, the arrangement being such that when said engagement profile is in a supported position: the engagement means is adapted to be cooperably engaged by said engagement profile to limit movement of the support portion relative to the engagement profile to a predetermined distance in a direction parallel to said longitudinal axis; and said engagement means is displaceable to allow disengagement of said engagement profile and said support portion.

13. A device for use in supporting ceiling formwork substantially as herein described with reference to the accompanying drawings.