CA2781450C

CA2781450C - Stripping apparatus

Info

Publication number: CA2781450C
Application number: CA2781450A
Authority: CA
Inventors: Bernd Renz; Sergio Altavini
Original assignee: Peri GmbH
Current assignee: Peri SE
Priority date: 2009-11-25
Filing date: 2010-11-22
Publication date: 2017-05-23
Anticipated expiration: 2030-11-22
Also published as: KR20120099701A; WO2011063922A1; RU2519316C2; EP2480735B1; DE102009055690A1; EP2480735A1; CN102667031A; RU2012126111A; CA2781450A1

Abstract

The invention relates to a formwork-stripping device with a corner formwork element (18) which can be connected on both sides to in each case a further formwork element (20), wherein a vertically movable pull rod (30) is provided in the corner formwork element for moving the further formwork elements relative to the corner formwork element. The pull rod has an engagement surface, which can be moved together with it, for a lever and/or a coupling region (32), which can be moved together with it, for a pull chain.

Description

CA 02781, STRIPPING APPARATUS

The invention relates to a stripping apparatus having a corner formwork element which can be connected at each side to a further formwork element, wherein a vertically movable pull rod is supported in the corner formwork element, said pull rod being able to be coupled with the two further formwork elements via a plurality of articulated levers such that these two further formwork elements can be moved relative to the corner formwork element by a vertical movement of the pull rod.
Such stripping apparatus are known from the prior art and are in particular used in shaft formwork which can, for example, be used to manufacture elevator shafts of concrete. Such shaft formwork comprises an outer shaft formwork and an inner shaft formwork which include a volume between them which is filled with concrete. Whereas the outer shaft formwork can be separated in a simple manner from the hardened concrete by a movement taking place outwardly, the release of the inner shaft formwork from the hardened concrete is more complicated. In this respect, different sections of the inner shaft formwork namely have to be moved inwardly toward one another simultaneously or after one another in order thus to reduce the extent of the inner shaft formwork and thereby to allow a release thereof from the hardened concrete. An inner shaft formwork released in this manner can then be pulled out of a completely concreted, upwardly open shaft by means of a crane sling.
As already mentioned above, there is inner shaft formwork having corner formwork elements in which a vertically movable pull rod actuates articulated levers which serve to move individual sections of inner shaft formwork inwardly.

CA 02781,

2 The fact is disadvantageous in these stripping apparatus that a vertical movement of the pull rod can only be triggered via the rotating movement of a spindle, with the point of engagement for the spindle as a rule lying in the upper end region of a corner formwork element. This has the effect in an economically disadvantageous manner that the spindle has to be kept in store, installed and dismantled as a separate part. It is in addition disadvantageous that a person who installs and actuates the spindle first has to climb onto the inner shaft formwork, which is associated with an effort, on the one hand, and which causes a risk of falling, on the other hand. This disadvantage in particular comes into effect when a plurality of shaft formwork parts, for example three shaft formwork parts arranged over one another, are coupled with one another since in this case the spindle can only be actuated at the upper end region of the topmost formwork, which then naturally additionally increases the effort and risk.
One object underlying the invention comprises further developing a stripping apparatus such that it can be released from the hardened concrete with as little effort as possible and without any risk where possible.
This object is satisfied by a stripping apparatus in accordance with claim 1. The object is in particular satisfied in that the pull rod has an engagement surface for a lever movable vertically and linearly together with the pull rod and/or has a coupling region for a pull chain movable vertically and linearly for triggering a vertical movement of the pull rod.
In accordance with the invention, the movement of the pull rod and of the articulated levers connected thereto is therefore no longer triggered by the rotating movement of a spindle provided at the pull rod just for this purpose. A vertical movement which takes place only linearly, preferably CA 02781,

3 upwardly, of the pull rod can rather be produced in accordance with the invention in that an engagement surface fixedly provided at the pull rod is linearly moved by means of a lever or a coupling region fixedly attached to the pull rod is linearly moved in a vertical direction by means of a pull chain. Since therefore the pull rod is equipped in advance with the named engagement surface and/or with the named coupling region, the provision of a spindle at the upper end region of the corner formwork element required in the prior at is superfluous. In accordance with the invention, it is thus also no longer possible to convert the rotating movement of a spindle into a linear movement of the pull rod since the actuation force applied to the pull rod in accordance with the invention already acts in a linear fashion via the engagement surface or via the coupling region in that direction into which the pull rod should ultimately be moved.

It is further also not necessary in accordance with the invention to provide an engagement surface or coupling region in the upper end region of a corner formwork element, as was previously the case with the spindles used in accordance with the prior art. The engagement surface and/or the coupling region can rather also be attached to a region of the pull rod disposed further below. The engagement surface can in particular be attached so far below that a person standing on the ground can comfortably operate a lever set on the engagement surface. The coupling region can correspondingly be arranged at such a height on the pull rod that a pull chain or a crane sling can likewise be suspended at the coupling region comfortably by a person standing on the ground. It is thus not necessary either for this suspension or for the actuation of the lever to climb onto the inner shaft formwork so that the risk of falling previously present in the prior art is completely avoided. In addition, a reduction in effort, which results in substantial economic advantages, is achieved by CA 02781,

4 the saving of the climbing procedure and the no longer required attachment of a spindle.

A standard inner shaft formwork has four corner formwork elements which can, in accordance with the invention, each be equipped with a coupling region for a pull chain in the region of their respective pull rods.
The coupling regions of the four pull rods are in this respect as a rule located at the same height. Since consequently a total of four such coupling regions are provided at the same height in all four corner regions of such inner shaft formwork and since the spacing of all coupling regions from the center or from the center longitudinal axis of the inner shaft formwork is of the same size in each case, a standard sling of a crane having four chain sections of the same length in each case can be used in an advantageous manner for lifting the stripped inner shaft formwork, which produces a further advantage in accordance with the invention.
This is, in contrast, not always the case with inner shaft formwork known from the prior art since there a crane sling is often attached spaced apart from the corner regions.

It is advantageous if both an engagement surface for a lever and a coupling region for a pull chain are provided at each pull rod. In this case, the release of such inner shaft formwork from a concreted wall can be effected using a comparatively large lever force which is in every case sufficient to overcome the high holding forces which exist between the concreted wall and the sheathing of an inner shaft formwork after the concreting. After this release procedure, the further, inwardly directed movement of the individual elements of the inner shaft formwork can then be effected by means of a crane sling which is attached to the coupling regions of the pull rods. The named lever is then no longer needed for this further movement.

CA 02781, The release of the inner shaft formwork from the concreted walls can thus be effected solely by means of the named lever without the use of a crane, with the further movement of the elements of the inner shaft formwork to the inside being able to take place after the fully completed release process

5 and the raising of the inner shaft formwork reduced in extend in this manner being able to take place solely by means of a crane.

The engagement surface for the lever is advantageously provided beneath the coupling region for the pull chain. A particularly good operability of the lever is achieved when the engagement surface is provided approximately at knee level of a person actuating the lever and a comfortable suspension of a pull chain into the coupling region is possible when the coupling region is located approximately at breast level of a person handling the pull chain. The engagement surface for the lever is preferably less than 1 m from the lower end of the corner formwork element and/or the coupling region for the pull chain is preferably less than 2 m, in particular approximately 1.5 m, from the lower end of the corner formwork element.

The corner formwork element in accordance with the invention and the two further formwork elements connected to it can be coupled with one another such that first a movement of the two further formwork elements directed obliquely to the respective sheathing and substantially horizontally can be triggered by a vertical movement of the pull rod and subsequently a relative movement between the corner formwork element and the two further formwork elements directed substantially parallel to the respective sheathing can be triggered. In this respect, the first movement directed obliquely to the respective sheathing is preferably effected using the named lever and all further movements are effected using the named pull chain. The movement directed obliquely to the CA 02]81,

6 sheathing can take place over a comparatively small travel and only effects the release of the sheathing from the concreted wall. After this short, obliquely directed movement, the sheathing released from the concreted wall can have a spacing therefrom of approximately 5 to 10 mm, in particular approximately 7 mm. The movement directed parallel to the sheathing takes place over a larger travel and has the effect that the individual elements of the stripping apparatus in accordance with the invention move substantially perpendicular away from the concreted wall.
The spacing between the sheathing and the concreted wall after this movement can amount, for example, to approximately 2.5 to 4 cm, in particular approximately 3.5 cm. It is consequently advantageous that the sheathing is only moved over a small path distance obliquely to the concreted wall and subsequently perpendicular to the concreted wall, which has the consequence that nails introduced into the sheathing are pulled out of it in a substantially straight manner in the stripping procedure so that the sheathing is only very slightly damaged by the stripping procedure. On a pulling out of the nails taking place completely obliquely, which frequently occurs in the prior art, or on a movement of the sheathing along the concreted wall at the start of the stripping process, substantially greater damage to the sheathing occurs.

The described relative movements between the corner formwork element and the two further formwork elements can be defined by at least one guide slot which preferably has two slot sections extending substantially at an angle to one another. In this respect, in particular a slot section extending parallel to the sheathing is longer than a slot section extending obliquely to the sheathing. The shorter slot section is thus responsible for the explained movement directed obliquely to the sheathing, whereas the longer slot sections control the movement of the sheathing element directed substantially vertically to the sheathing. A possible embodiment CA 02781,

7 of the named guide slot will be explained in more detail as part of the description of the Figures.

The corner formwork element in accordance with the invention can have a base region and two coupling strips movable relative thereto which can each be rigidly coupled to a further formwork element. In this respect, the edge regions of the base region adjacent to the two coupling strips can each have a metal bracket section which extends over the height of the base region and which has a reception region between the bracket limbs for a respective region of one of the coupling strips and a marginal region of a further formwork element coupled therewith. Whereas a bracket limb of such a bracket section forms a region of the sheathing of the corner formwork element, the other bracket limb serves for the rigid fastening of the bracket section to the base region of the corner formwork element.
Within the framework of a release movement of one of the two further formwork elements from a concreted wall directed obliquely to the sheathing, the coupling strip associated with this formwork element has to move away from the concreted wall together with the respective formwork element only by such a distance which corresponds to the thickness of that bracket limb which forms a sheathing section. This coupling strip can then subsequently be moved between the two bracket limbs together with a section of the respective formwork element, with this movement being able to take place parallel to the sheathing of the further formwork element.
The design of the corner formwork element with a base region and two coupling strips causes in an advantageous manner that all parts which are movable relative to one another are located in the corner formwork element so that such corner formwork elements or their coupling strips can be connected in a standard manner to conventional further formwork CA 02781,

8 elements. A provision of special further formwork elements is thus not necessary, which increases the profitability of the invention.

The corner formwork element comprising a metal frame can have an outwardly disposed forming area which is covered by a wooden sheathing over at least an area portion of 80%. This causes in an advantageous manner that nails can be introduced into a large part of the surface region of the forming area of a corner formwork element, as is required, for example, for fastening Halfen channels.
The pull rod in accordance with the invention can be formed as a draw tube, with the draw tubes of two corner formwork elements arranged over one another being able to be connected to one another. It thus becomes possible that two or more stripping apparatus in accordance with the invention are stacked over one another and are connected to one another so that they ultimately behave as a single stripping apparatus which can then easily have approximately a height of 8 m overall. An actuation of the pull rod of the bottommost corner formwork element taking place via the engagement surface in accordance with the invention and/or via the coupling region in accordance with the invention can effect a movement of all mutually coupled pull rods of the corner formwork elements stacked over one another by the connection of the draw tubes so that two or three stripping apparatus stacked over one another can, for example, be stripped simultaneously. Since a standard crane sling can thus be suspended at the bottommost pull rod, smaller required crane heights result in an advantageous manner than on the suspension of a standard crane sling at the topmost pull rods.

The invention not only includes the above-explained stripping apparatus, but also a complete inner shaft formwork in which four corner formwork CA 02781,

9 elements are provided, with at least one further formwork element each being arranged between two adjacent formwork elements. All corner formwork elements and further formwork elements are in this respect connected to one another in the manner in accordance with the invention;
each of the four corner formwork elements in particular respectively has a pull rod with an engagement surface and/or a coupling region.
If an inner shaft formwork should not be realized completely in accordance with the invention, it is naturally also sufficient only to use a single corner formwork element in accordance with the invention and to use fixed or conventional corner formwork elements at the other corners of the inner shaft formwork. In this case, the individual forming elements are then stripped after one another after the pull rod of the one corner formwork element in accordance with the invention was actuated.

Further preferred embodiments are explained in the dependent claims.
The invention will be described in the following with reference to an embodiment and to the drawings; there are shown in these:

Fig. 1 a plan view of a shaft formwork in accordance with the invention;

Fig. 2 a detailed view of a corner region of the shaft formwork in accordance with Fig. 1;
Figs. 3a to d four different positions of a corner formwork element of the inner shaft formwork in accordance with Figs. 1 and 2 resulting in the stripping process;

CA 02781, Fig. 4a a view of the inner side of a stripping apparatus in accordance with the invention in the shuttered state;

Fig. 4b a plan view of the upper side of the corner formwork 5 element in accordance with Fig. 4a;

Fig. 5a a view of the inner side of a stripping apparatus in accordance with the invention in the stripped state; and

10 Fig. 5b a plan view of the upper side of the corner formwork element in accordance with Fig. 5a.

Fig. 1 shows a plan view of a shaft formwork 10 in accordance with the invention which comprises an inner shaft formwork 12 as well as an outer shaft formwork 14. The inner shaft formwork 12 and the outer shaft formwork 14 are connected to one another by means of a plurality of formwork ties 16.

The shaft formwork 10 has a substantially rectangular shape, with the inner shaft formwork 12 and the outer shaft formwork 14 each being composed of a plurality of corner formwork elements and a plurality of further formwork elements extending along a plane. The inner shaft formwork 12 essential within the formwork of the invention comprises a total of four corner formwork elements 18 to which respective further formwork elements 20 are adjacent which extend along a plane. Mutually adjacent formwork elements 18, 20 are connected to one another by means of suitable coupling apparatus 22.

The inner shaft formwork 12 and the outer shaft formwork 14 form a hollow space 24 between them which serves for the reception of liquid CA 02781,

11 concrete. After the hardening of the concrete, the outer shaft formwork 14 is released from the hardened concrete by releasing the coupling apparatus 22 and removing the individual formwork elements of the outer shaft formwork 14. The release and removal of the inner shaft formwork

12 is a subject of the present invention and will be explained in the following.

Fig. 2 shows a detailed view of the left lower corner region of the shaft formwork 10 in accordance with Fig. 1. The inner shaft formwork 12 in this corner region comprises a corner formwork element 18 which is respectively connected to a further formwork element 20 at both mutually remote end regions. The corner formwork element 18 has two forming areas 26 which extend perpendicular to one another and which are each continued by forming areas 28 of the two further formwork elements 20.
In that region in which its two limbs are adjacent to one another, the corner formwork element 18 has a pull rod 30 which extends substantially over the total height of the corner formwork element 18 and through said corner formwork element in the vertical direction perpendicular to the plane of the drawing of Fig. 2. The pull rod 30 is in this respect in a manner in accordance with the invention provided with an engagement surface still to be explained for a lever and with a coupling region 32 for a pull chain. In accordance with the invention, the corner formwork element 18 is not rigidly connected to the two further formwork elements 20, but rather in a movable manner, which will be explained in the following in connection with Figs. 3 to 5.

Figs. 3a to d show in a plan view elements which have still to be described in the following and via which the corner formwork element 18 is connected to the two further formwork elements 20, with these elements CA 02781, being present in multiple form distributed over the height of the corner formwork element 18 and further formwork elements 20. Four vertical regions hi to h4 are drawn in Fig 4a at which the elements shown in Fig.
3a are respectively located.
Fig. 3a shows the corner formwork element 18 and the two further formwork elements 20 in their shuttered position, that is in that position in which an inner shaft formwork 12 has its maximum extent and adheres to the hardened concrete 34.
The corner formwork element 18 has a base region 19 and two coupling strips 21 movable relative thereto. The two coupling strips 21 are each rigidly connected to a further formwork element 20 via coupling apparatus 22. In their end regions facing the coupling strips 21, the base regions 10 each have a metal bracket section 36, 38 of which one bracket limb 36 forms a part of the sheathing of the corner formwork element 18. The other bracket limb 38 extends perpendicular to the sheathing and serves for the fastening of the bracket section 36, 38 to the base region 19 of the corner formwork element 18.
The two coupling strips 21 are each equipped in their end regions respectively facing the bracket limbs 36 with a metal sloping surface 40 which like the bracket sections 36, 38 extends over the total height of the formwork elements 18, 20. The sloping surface 40 in this respect reaches up to the hardened concrete 34 in the shuttered position in accordance with Fig. 3a and is thus directly adjacent to the bracket limbs 36 in this position.

The corner formwork element 18 is covered over a large part of its forming area 26 by a nailable sheathing 42, in particular made of wood or plastic.
Only the forming area formed by the bracket limbs 36 and the coupling CA 02781,

13 strips 21 as well as a metal corner protection section 44 are not nailable, whereby it is achieved that nails can be driven into the very predominant portion of the forming area 26 of the corner formwork element 18 in order to fasten Halfen channels, for example.
Respective guide lugs 46 of the coupling strips 21 connected to the further formwork elements 20 extend in the horizontal direction in the direction of the pull rod 30 of the base region 19. The guide lugs 46 in this respect each have an elongate hole 48 in the region of the pull rod 30 through which the pull rod 30 extends. The elongate holes 48 are formed so that they allow a horizontal relative movement of the guide lugs 46 taking place in the plane of the drawing with respect to the pulling rod 30 and thus of the coupling strips 21 with respect to the base region 19.

Furthermore, each of the two guide lugs 46 shown in Fig. 3a has a guide slot which each comprises two slot sections 50, 52. The two slot sections 50, 52 extend at an angle to one another, with the angle between both slot sections 50, 52 amounting approximately to 45 . The longer slot section 50 extends parallel to the sheathing 28 of that further formwork element 20 which is connected to that coupling strip 21 in whose guide lug 45 the slot 50, 52 is formed. The shorter slot section 52 extends, starting from the end of the longer slot section 50 facing the pull rod 30, obliquely away from the sheathing 28. A guide pin 54 having a circular cross-section and in turn fixedly connected to the base region 19 of the corner formwork element 18 is received in the guide slot 50, 52.

If now a relative movement is triggered via the pull rod 30 between the base region 19 and the coupling strips 21 or the further formwork elements 20 connected to them in a manner still to be explained in connection with Figs. 4 and 5, the further formwork elements 20 move CA 02781,

14 toward the base region 19 of the corner formwork element 18, with their movement in this respect being controlled by the guide slots 50, 52 and by the guide pins 54.

At the start of the named movement, the two further formwork elements 20 having the coupling strips 21 move in the direction of the arrows drawn in Fig. 3a, with the guide slot 50, 52 being displaced with respect to the guide pin 54 such that the guide pin 54 comes to lie in that region in which the shorter slot section 52 is adjacent to the longer slot section 50.
This position is shown in Fig. 3b. During the movement from the position in accordance with Fig. 3a into the position in accordance with Fig. 3b, the sloping surface 40 of the coupling strips 21 slides along the end face of the bracket limb 36. The forming areas 28 of the two further formwork elements 20 have released from the hardened concrete while overcoming the existing adhesion forces due to the named relative movement between the coupling strips 21 or the further formwork elements 20, on the one hand, and the base region 19 of the corner formwork element 18, on the other hand, so that there is a small spacing between the hardened concrete 34 and the forming areas 28. This spacing is at least as large as the thickness of the bracket limb 36. If this procedure takes place simultaneously or after one another at all four corners, the forming area 26 also releases from the hardened concrete 34 in some corner formwork elements.

On a continued movement of the pull rod 30, the further formwork elements 20 move further toward one another in the direction of the arrows drawn in Figs. 3b and 3c. This movement is now controlled by the longer slot section 50 and by the guide pin 54 as can be seen from Figs. 3c and 3d. At the end of the movement, the guide pin 54 is located at the end of the longer slot section 50 remote from the base region 19. In this CA 02781, movement illustrated in Figs. 3c and 3d, the two limbs of the base region 19 and the two further formwork elements 20 respectively associated with them move toward one another in planes extending parallel to one another, which means that an oblique movement no longer takes place in 5 this movement such as was present on a movement from the position in accordance with Fig. 3a into the position in accordance with Fig. 3b. On the movement in accordance with Figs. 3c and 3d, the coupling strips 21 of the end region of the further formwork elements 20 each facing the corner formwork element 18 each move into a reception space formed 10 between the two bracket limbs 36, 38. In this respect, the forming areas 28 of the further formwork elements 20 slide along the inner sides of the bracket limbs 36.

Since the movement described in connection with Figs. 3a to 3d takes

15 place simultaneously at all four corner regions of an inner shaft formwork 12 in accordance with Fig. 1, all corner formwork elements 18 and further formwork elements 20 - each controlled by the longer slot sections 50 -simultaneously move inwards to that the outer extent of the inner shaft formwork 12 reduces in size overall. It is hereby ensured that not only the further formwork elements 20, but rather all corner formwork elements 18 release from the hardened concrete 34. Accordingly, Fig. 3d not only shows a spacing between the forming areas 28 of the further formwork elements 20 and the hardened concrete 24, but also a spacing between the sheathing 26 of the corner formwork element 18 and the hardened concrete 34.

Fig. 4a shows an inner view of the corner formwork element 18 in accordance with Figs. 1 to 3 which is coupled at both sides in the described manner to further formwork elements 20. Fig. 4b shows a plan view of this arrangement; however, without the two further formwork CA 02781,

16 elements 20. The corner formwork element 18 and further formwork elements 20 are located in accordance with Figs. 4a and 4b in their shuttered state which corresponds to the position in accordance with Fig.
3a.
It can be seen from Fig. 4a that the pull rod 30 is connected via a total of eight articulated levers 56 to fastening lugs 58 of the coupling strips 21, with the coupling strips 21 in turn being rigidly coupled with the further formwork elements 20. The articulated levers 56 are in this respect pivotally supported both at the pull rod 30 and to the fastening lugs 58.
A prolongation 31 via which the pull rod 30 can be coupled to the lower end of the pull rod of a further corner formwork element which can be placed onto the corner formwork element 18 is located at the upper end of the pull rod 30.
In the region of the height h2, the pull rod is provided with the coupling region 32 into which a pull chain or a crane sling can be hung.
Somewhat below the height h3, the pull rod 30 is guided in a sleeve 60 which has a total of four cutouts 62 into which a respective lever, not shown, can be introduced. The pull rod itself likewise has a cutout 64 in the region of the sleeve 60, said cutout forming an engagement surface for the lever and being covered to a large extent by the sleeve 60 in Fig. 4a.
The sleeve 60 has such large dimensions that a sufficiently large spacing is present between its cutouts 62 and the cutout 64 in the pull rod 30 so that a lever inserted through a cutout 62 into the cutout 64 can vertically upwardly raise the pull rod 30 by a downwardly taking place pressing of the lever. In practice, such a raising movement as a rule takes place several times, with here different cutouts 62 of the sleeve 60 respectively CA 02781,

17 being used. The pull rod 30 is in particular raised so long by means of the lever until the position in accordance with Fig. 3d is reached.

Figs. 5a and 5b correspond to Figs. 4a and 4b, with the stripped position in accordance with Fig. 3d already being reached in accordance with Figs.
5a and 5b. It can be seen from Fig. 5a that the articulated levers 56 are likewise drawn upwards by the upwardly taking place movement of the pull rod 30 and in so doing pull the two coupling strips 21 with their further formwork elements 20 in the direction of the pulling rod so that the articulated levers 56 ultimately adopt the oblique position shown in Fig 5a. The cut-out 64 is now located in accordance with Fig. 5a in the region between the two upper cutouts 62 of the sleeve 60, whereas they were still located in the region of the two lower cutouts 62 of the sleeve 60 in Fig. 4a.
In the position shown in Figs. 3d, 5a and 5b, all formwork elements 18, 20 are released from the hardened concrete so that a crane sling can be fastened to the coupling region 32. After such a fastening has taken place at all four corner regions of an inner shaft formwork 12 in accordance with Fig. 1, the inner shaft formwork can be pulled upwardly out of the hardened concrete shaft.

In accordance with the invention, very small inner shaft formworks can also be realized since, for example, further formwork elements 20 having a very small width can be used. The minimal width of the further formwork elements 20 only has to be dimensioned such that the coupling apparatus 22 can be fastened thereto. Alternatively, it is also possible to fasten two corner formwork elements 18 directly to one another, for example by means of an alignment coupler, without a further formwork element 20 being located between these corner formwork elements 18. For this CA 02781,

18 purpose, two coupling strips 21 of the two corner formwork elements 18 are then directly connected to one another. Even smaller inner shaft formworks can then be produced in this manner.

CA 02781,

19 Reference numeral list shaft formwork 12 inner shaft formwork 5 14 outer shaft formwork 16 formwork tie 18 corner formwork element 19 base region further formwork elements 10 21 coupling strips 22 coupling apparatus 24 hollow space 26 forming area 28 forming area 15 30 pull rod 31 prolongation 32 coupling region 34 hardened concrete 36 bracket limb

20 38 bracket limb 40 sloping surface 42 sheathing 44 corner protection section 46 guide lug 48 elongate hole 50 longer slot section 52 shorter slot section 54 guide pin 56 articulated lever 58 fastening lug CA 02781, 60 sleeve 62 cutouts 64 cutout

Claims

What is claimed is:

1. A stripping apparatus of an inner shaft formwork having a corner formwork element which can be connected at each side to a further formwork element, wherein a vertically movable pull rod is supported in the corner formwork element and can be coupled to the two further formwork elements via a plurality of articulated levers such that these two further formwork elements are movable relative to the corner formwork element by a vertical movement of the pull rod, characterized in that the pull rod has an engagement surface for a lever movable vertically and linearly together with the pull rod and/or a coupling region for a pull chain movable vertically and linearly together with the pull rod for triggering a vertical movement thereof.

2. A stripping apparatus in accordance with claim 1, characterized in that the engagement surface for the lever is arranged beneath the coupling region for the pull chain; and/or in that the engagement surface for the lever is spaced apart from the lower end of the corner formwork element by less than 1 m.

3. A stripping apparatus in accordance with any one of claims 1 or 2, characterized in that the coupling region for the pull chain is spaced apart from the lower end of the corner formwork element by less than 2 m.

4. A stripping apparatus in accordance with claim 3, characterized in that the coupling region for the pull chain is spaced apart from the lower end of the corner formwork element by approximately 1.5 m.

5. A stripping apparatus in accordance with any one of claims 1 to 4, characterized in that the corner formwork element and the two further formwork elements can be coupled such that a movement of the two further formwork elements directed obliquely to the respective sheathing can first be triggered by a vertical movement of the pull rod and subsequently a relative movement between the corner formwork element and the two further formwork elements directed at least substantially parallel to the respective sheathing can be triggered.

6. A stripping apparatus in accordance with any one of claims 1 to 5, characterized in that the relative movements between the corner formwork element and the two further formwork elements are defined by at least one guide slot.

7. A stripping apparatus in accordance with claim 6, characterized in that the guide slot has two slot sections.

8. A stripping apparatus in accordance with claim 7, characterized in that the two slot sections extend at an angle to one another.

9. A stripping apparatus in accordance with claim 8, characterized in that a slot section extending parallel to the sheathing is longer than a slot section extending obliquely to the sheathing.

10. A stripping apparatus in accordance with any one of claims 1 to 9, characterized in that the corner formwork element has a base region and two coupling strips movable relative thereto which can each be rigidly coupled with a further formwork element.

11. A stripping apparatus in accordance with claim 10, characterized in that the edge regions of the base region adjacent to the two coupling strips each have a metal bracket section extending over the height of the base region which has a reception region between the bracket limbs for a respective region of one of the coupling strips and a marginal region of a further formwork element coupled therewith.

12. A stripping apparatus in accordance with any one of claims 1 to 11, characterized in that the corner formwork element having a metal frame has an outwardly disposed forming area which is covered at least over a surface portion of 80% with a nailable sheathing.

13. A stripping apparatus in accordance with claim 12, characterized in that the nailable sheathing comprises wood or plastic.

14. A stripping apparatus in accordance with any one of claims 1 to 13, characterized in that the pull rod is designed as a draw tube, with the draw tubes of two corner formwork elements arranged above one another being connectable to one another.

15. An inner shaft formwork having at least one apparatus in accordance with any one of claims 1 to 14 which has four corner formwork elements, wherein at least one further formwork element is arranged in each case between two adjacent corner formwork elements.