Patent Grant
10934726
This application relates to and claims the benefit and priority to International Application No. PCT/ES2015/070757, filed Oct. 20, 2015.
The present invention relates to conical spacers used in concrete formworks for building concrete walls or pillars, and more specifically to tools for extracting the spacers from the concrete once it is set.
Concrete walls or pillars are usually made on site providing a gap between two formwork panels that are arranged such that they are facing one another. Said panels are secured to one another by means of transverse tie bolts which traverse said panels. The ends of the bolts project from the panels and are threaded to allow placing the corresponding nuts.
Once the panels are secured, concrete is poured into the gap which is arranged sandwiched between the formwork panels. To prevent the concrete from adhering to the transverse tie rods once it sets, said tie rods are usually covered by or placed inside a PVC tube. Conical spacers, also usually made of PVC, are placed at the ends of the tube and are supported against the inner face of the corresponding formwork panel. Once the concrete sets, the formwork panels and the transverse tie rods are disassembled and the conical spacers are extracted. A hammer and a chisel are normally used to extract the conical spacers.
The extraction of the tube is optional and largely depends on the application of the wall. For example, in concrete walls intended for containing a fluid, where correct sealing of the wall is very important, such as for example water tanks, swimming pools, lubricant tanks, etc., it is suitable to extract said tube for assuring the leak-tightness of the wall.
When the tie rods are disassembled they provide through holes in the concrete wall that must be closed and sealed to prevent water seepage in the wall.
The formwork process for the wall of a building, a retaining wall of a dam or that of a pillar is similar.
U.S. Pat. No. 5,813,185A discloses a cylindrical tube internally housing a transverse tie rod that is used to secure two formwork panels arranged parallel facing one to another. A conical spacer is detachably coupled at each end of the tube. The ends of the transverse tie rods are threaded, each end being attached to a conical spacer by the inner face thereof. An additional bolt is screwed to each conical spacer such that it projects from the corresponding formwork panel. Once the concrete sets, the additional bolts are extracted and the corresponding formwork panels are disassembled. A hex key is used to extract the conical spacers, such that when the hex key is turned, it causes the spacer to turn, thereby unscrewing it from the transverse tie rod. The conical spacers described in U.S. Pat. No. 5,813,185A comprise a hexagonal recess which makes it easier to insert the hex key.
An extractor for extracting conical spacers is provided that comprises a stem and a handle arranged at one end of the stem. At the other end, the stem comprises a conical spacer engagement device cooperating with the conical spacer for extracting said conical spacer. The extractor also comprises a mobile element which is displaceable by the user along the stem between a retracted position to which said mobile element is moved in order to contribute to the extraction of the conical spacer of the concrete wall or pillar, and an advanced position to which the mobile element is moved in order to push the conical spacer for releasing it from the conical spacer engagement device of the stem.
In an initial coupling step, the conical spacer engagement device is fixed to the conical spacer, then in an extraction step the mobile element is moved, preferably manually, to the retracted position, the corresponding conical spacer being extracted, and finally the mobile element is moved again, preferably manually, in an expulsion step to the advanced position, releasing the conical spacer from the conical spacer engagement device.
With the extractor and the method disclosed conical spacers are extracted from a concrete wall or pillar in a simple, quick and effective manner, without damaging the concrete wall, which entails a significant time savings in building the concrete wall. The conical spacers extracted with the tool and the method of the invention can be used again because they deteriorate very little during the extraction process, and are released from the extractor in a simple, quick and effective manner.
These and other advantages and features will become evident in view of the drawings and the detailed description.
When building a wall 201 such as the one shown schematically as an example in
For the sake of establishing a longitudinal orientation of the components of the extractor 1 as recited in the claims, the handle 4 is considered to reside at a proximal end of the extractor and the conical spacer engagement device is considered to reside at a distal end of the extractor.
The extractor 1 significantly reduces the time required for extracting conical spacers 101, making the extraction of said conical spacers 101 a simple, effective and quick operation to perform. The concrete wall 201 is not damaged with the extractor 1, and therefore the subsequent sealing of the corresponding holes, required in some applications, such as in a retaining wall of a dam, etc., is more effective.
The conical spacers 101 extracted with the extractor 1 can be reused because they deteriorate very little during the extraction process, such it contributes to obtain considerable savings in construction material.
According to one embodiment, the stem 2 is cylindrical and internally comprises an at least partially threaded through hole. In a non-limiting example of the invention, said inner hole is threaded along the entire length thereof, as shown in
As shown in
According to one embodiment, said proximal stop 2′ is cylindrical and projects radially from the stem 2. The proximal stop 2′ may be an integral part of the stem 2, as seen in the drawings, but optionally it could be a separate part fixed to the stem 2 by pressure fitting, through threaded means, or by similar processes.
In a variant not shown in the drawings, the proximal stop 2′ could comprise at least two protuberances projecting radially from the stem 2, said protuberances being arranged equidistantly around the outer circumference of the stem 2.
According to one embodiment, the mobile element 5 is cylindrical and internally comprises a through hole which is traversed by the stem 2, as shown in
The first stop surface 5a of the mobile element 5 is arranged at one end of the mobile element 5, logically at the end arranged closest to the proximal stop 2′. Preferably, said first stop surface 5a is arranged at the bottom of a recess 5e, as shown in the detail of
According to one embodiment, the extractor 1 comprises distal stop 3′ arranged at the end of the stem 2 next to the conical spacer engagement device 3A. Said distal stop 3′ comprises a distal stop surface 3B cooperating in the advanced position with a second stop surface 5b comprised in the mobile element 5, as shown in
Like the proximal stop 2′, said distal stop 3′ may be cylindrical and projects radially from the stem 2, being arranged adjacent to the conical spacer engagement device 3A. The distal stop 3′ and the conical spacer engagement device 3A form a detachable active end 3 that is fixed to the free end of the stem 2 by non-permanent attachment means, for example threaded means. This configuration allows the simple and quick insertion, and extraction when required, of the stem 2 in the mobile element 5. To make assembly of the active end 3 easier, according to one embodiment said active end 3 comprises a threaded protuberance 3C at the end opposite the conical spacer engagement device 3A, as seen in
To assemble the mobile element 5 on the stem 2, the active end 3 must first be disassembled and once the mobile element 5 is assembled, the active end 3 is fixed to the stem 2 again. The mobile element 5 is thereby trapped between the two stops 2′ and 3′, the conical spacer engagement device 3A being arranged outside the area delimited by both stops 2′ and 3′. The distance “d” between these two stops 2′ and 3′ is greater than the length “L” of the mobile element 5, therefore the mobile element 5 can move between these two stops 2′ and 3′.
In one variant not shown in the drawings, the active end 3 is not detachable and can be fixed to the end of the stem 2 by other means, such as welding, or it can be configured such that it is an integral part of the stem 2. In this variant, the handle 4 and the proximal stop 2′ will be detachable to allow the insertion, and extraction when required, of the mobile element 5, by proceeding in a manner similar to that described in the preceding paragraph.
Optionally, in another embodiment not shown in the drawings, the distal stop 3′ could comprise at least two protuberances that project radially from the stem 2, said protuberances being arranged equidistantly around the outer circumference of the stem 2.
The second stop surface 5b of the mobile element 5 is arranged at the other end of the mobile element 5, i.e., at the end arranged closest to the distal stop 3′. Preferably, said second stop surface 5b is arranged at the bottom of an internal recess 5c, as shown in the detail of
Most conical spacers 101 of the state of the art are made of plastic, preferably PVC, and comprise an inner hole to allow the passage of the transverse tie rod. Said inner hole is threaded in some cases and in others it is not.
According to one embodiment both the stem 2 and the mobile element 5 and the active end 3 are metallic, preferably made of steel, and the length “L” of the mobile element 5 is greater than its diameter, as seen in
According to one embodiment, the conical spacer engagement device 3A of the extractor 1 is conical, as shown in the drawings, which favors the insertion of said conical spacer engagement device 3A into the inner hole of the corresponding conical spacer 101. Furthermore, said conical configuration enables the conical spacer engagement device 3A to adapt to different diameters, which favors being able to use the extractor 1 in different types of conical spacers, it being unnecessary to adapt the conical spacers of the state of the art to use the extractor 1.
According to one embodiment, the conical spacer engagement device 3A comprises a threaded area, not depicted in the drawings. When said threaded area of the conical spacer engagement device 3A is turned inside the conical spacer 101, the metallic threading generates a small indent inside the corresponding conical spacer 101, both elements being attached to one another. The extractor 1 does not have to penetrate far into the conical spacer 101 in order to cause said attachment.
In a coupling step, the user fixes the extractor 1 to the conical spacer 101 as indicated in the preceding paragraph, i.e., the extractor 1 is turned manually in the inner hole of the conical spacer 101 while the user keeps the extractor 1 upright by the handle 4 in order to make the small indent in the conical spacer 101 if the latter is not previously threaded.
Then in an extraction step, the user moves the mobile element 5 manually to the retracted position of the extractor 1 such that the mobile element 5 hits against the proximal stop 2′. Due to the action and reaction forces that are generated, the extractor 1 pulls on the conical spacer 101, extracting it from the concrete wall 201 in a simple, quick and almost effortlessly manner. The extraction of the conical spacer 101 is clean, i.e., no cracks are formed in the concrete 201 around the corresponding conical spacer 101, as may occur in the case of using a hammer and chisel.
Since the stem is straight, the mobile element 5 follows a linear path.
Finally, in an expulsion step, the mobile element 5 of the extractor 1 is moved manually to the advanced position of the extractor 1, or to a position close to it, where the mobile element 5 pushes the conical spacer 101, quickly and effortlessly releasing it from the conical spacer engagement device 3A of the extractor 1. To that end, the mobile element 5 comprises a pushing surface 5d that pushes the corresponding conical spacer 101 out of the conical spacer engagement device 3A.
As is evident in view of the detailed description, the time for extracting conical spacers 101 from a concrete wall or pillar is drastically reduced, this method of extraction being safer than most of the methods used in the prior art.
The small indent caused by the conical spacer engagement device 3A scarcely damages the conical spacer 101, so said conical spacers 101 can be used again, once more contributing to obtaining significant savings in construction material.
The outer surface of the mobile element 5 may be knurled to make handling thereof easier.
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| 20180230702 | Elduayen Madariaga | Aug 2018 | A1 |
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| 2633037 | Feb 1977 | DE |
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| Entry |
|---|
| International Search Report and Written Opinion of the International Searching Authority of corresponding PCT application PCT/US2015/070757 dated Jan. 22, 2016. |
| Number | Date | Country | |
|---|---|---|---|
| 20180230702 A1 | Aug 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/ES2015/070757 | Oct 2015 | US |
| Child | 15952763 | US |
