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Title:
ANCHOR FOR A VERTICAL FORMWORK AND VERTICAL FORMWORK
Document Type and Number:
WIPO Patent Application WO/2017/215805
Kind Code:
A1
Abstract:
Anchor for a vertical formwork, comprising a fixed part (44) suitable for being fixed to a formwork panel (2) and fixing means for fixing said fixed part (44) to the formwork panel. The fixing means comprise a fixing key (46) suitable for being housed in a hole of the formwork panel (2), the fixing key (46) comprising an off-centered stop (460) with respect to the axis of rotation of the fixing key (46), such that in a first angular position the off-centered stop (460) of the fixing key (46) can be introduced in the hole of the formwork panel and in a second angular position the off-centered stop (460) is retained by the formwork panel, and therefore the anchor (4) is fixed to the formwork panel.

Inventors:
COLINO VEGA MANUEL (ES)
Application Number:
PCT/EP2017/058195
Publication Date:
December 21, 2017
Filing Date:
April 06, 2017
Export Citation:
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Assignee:
ULMA C Y E S COOP (ES)
International Classes:
E04G17/065; F16B5/10; F16B21/02
Domestic Patent References:
WO2014012853A12014-01-23
Foreign References:
FR2231875A11974-12-27
Attorney, Agent or Firm:
IGARTUA IRIZAR, Ismael (ES)
Download PDF:
Claims:
CLAIMS

Anchor for a vertical formwork comprising

- a fixed part (44, 50) suitable for being fixed to a formwork panel (2, 3) and

- fixing means for fixing said fixed part (44, 50) to the formwork panel (2,

3),

characterized in that

- the fixing means comprise a fixing key (46, 56) arranged in a fixing housing (48, 58) of the fixed part (44, 50), said fixing key (46, 56) being configured for being housed in a hole (210, 310) of a supporting wall (25, 35) of the formwork panel (2, 3), the fixing key (46, 56) comprising an off- centered stop (460, 560) with respect to the axis of rotation (464, 564) of the fixing key (46, 56), such that in a first angular position the off- centered stop (460, 560) of the fixing key (46, 56) can be introduced in the hole (210, 310) of the formwork panel (2, 3), and in a second angular position the off-centered stop (460, 560) is retained by the formwork panel (2, 3) and therefore the anchor (4, 5) is fixed to the formwork panel (2, 3).

Anchor according to claim 1 , wherein the fixing means comprise backward motion means cooperating with the fixing key (46), such that when the fixing key (46) turns from the first angular position to the second angular position, the backward motion means make the fixing key (46) move backwards, and therefore in the second angular position the fixing key (46) is supported against the formwork panel (2).

Anchor according to claim 2, wherein the backward motion means comprise a guide surface (480) arranged in the fixing housing (48) of the fixed part (44), and the fixing key (46) comprises a stop surface (461 ), said guide surface (480) and said stop surface (461 ) cooperating such that the fixing key (46) axially moves backwards when turning.

4. Anchor according to claim 3, wherein the guide surface (480) and the stop surface (461 ) are helical surfaces.

5. Anchor according to any of the preceding claims, wherein the fixing housing (48) comprises a retaining element (481 ) that prevents the fixing key (46) from being separated from said fixing housing (48).

6. Anchor according to claim 5, wherein the retaining element (481 ) is arranged in the fixing housing (48) such that it allows the off-centered stop (460) of the fixing key (46) to be housed inside the housing (48) without projecting from the inner face (441 ) of the fixed part (44) of the anchor (4).

7. Anchor according to any of the preceding claims, wherein the fixed part (50) comprises blocking means configured to retain the fixing key (56) when said fixing key (56) is in the second angular position, so that an involuntary turning of the fixing key (56) is avoided.

8. Anchor according to claim 7, wherein the fixing key (56) comprises a handle (563), the blocking means comprising a blocking element (59) comprising a stop member (590) configured to block the handle (563) in a blocking position, the blocking element (59) being coupled movably to the fixed part (50) of the anchor (5).

9. Anchor according to claim 8, wherein the blocking element (59) is coupled to the fixed part (50) by means of elastic means, said elastic means pushing the stop member (590) to the blocking position.

10. Anchor according to any of the preceding claims, wherein the fixed part (44, 50) comprises a pin (47, 57) suitable for being housed in a second hole (21 1 , 31 1 ) of the supporting wall (25, 35) of the formwork panel (2, 3). 1 1 . Anchor according to claim 10, wherein the pin (57) comprises a lateral groove (570) and the anchor (5) is configured to move upward when the fixing key (56) turns from the first angular position to the second angular position, the supporting wall (35) entering the groove (570) of the pin (57) when the anchor (5) moves upward, said pin (57) being retained by said supporting wall (35) when the fixing key (56) is in said second angular position.

12. Anchor according to claim 1 1 , wherein the fixing key (56) comprises a cam (561 ) that rests on a supporting surface (313) of the hole (310) of the supporting wall (35) that is traversed by said fixing key (56), the distance (D) from the axis of rotation (564) of the fixing key (56) to said supporting surface (313) being greater when said fixing key (56) is in the second angular position than the distance (d) from said axis of rotation (564) to said supporting surface (313) when the fixing key (56) is in the first angular position.

13. Anchor according to claim 12, wherein the cam (561 ) of the fixing key (56) is arranged between the off-centered stop (560) and a substantially cylindrical part

(562) of the fixing key (56), the axis of said cylindrical part (562) being the axis of rotation (564) of said fixing key (56), and the cylindrical part (562) being housed in the fixing housing (58) of the fixed part (50). 14. Vertical formwork comprising at least

- two formwork panels (2, 3) which are arranged facing one another, each of said formwork panels (2, 3) comprising at least one hole (210, 310) for fixing an anchor (4, 5), and

- an anchor (4, 5) according to any of the preceding claims fixed to each of said formwork panels (2, 3).

Description:
DESCRIPTION

"Anchor for a vertical formwork and vertical formwork"

TECHNICAL FIELD

The present invention relates to an anchor for a vertical formwork and to a vertical formwork.

PRIOR ART

The use of vertical formworks for making vertical structures, such as walls, is known. Vertical formworks comprise formwork panels arranged facing one another and fixed to one another by means of tie rods or anchor rods. The vertical formworks comprise anchors for fixing the tie rods to said formwork panels.

EP2126248A1 discloses a vertical formwork in which the anchors are fixed to the corresponding formwork panel by means of a threaded screw.

In order to prevent having to provide threaded holes in the formwork panel, patent document EP2875195A1 discloses a solution in which the threaded screw is replaced with a guided tilted screw housed in a non-threaded hole of the formwork panel.

DISCLOSURE OF THE INVENTION The object of the invention is to provide an anchor for a vertical formwork and a vertical formwork, as defined in the claims.

A first aspect of the invention relates to an anchor for a vertical formwork comprising a fixed part suitable for being fixed to a formwork panel, and fixing means for fixing said fixed part to the formwork panel. The fixing means comprise a fixing key configured for being housed in a hole of the formwork panel, the fixing key comprising an off-centered stop with respect to the axis of rotation of the fixing key. In a first angular position the off-centered stop of the fixing key can be introduced in the hole of the formwork panel, and in a second angular position the off-centered stop is retained by the formwork panel, and therefore the anchor is fixed to the formwork panel.

A second aspect of the invention relates to a vertical formwork comprising two formwork panels which are arranged facing one another, each of said formwork panels comprising at least one hole for fixing an anchor. The vertical formwork also comprises an anchor fixed to each of said formwork panels, the anchor having the features described above. The fixing means allow fixing the anchor to the formwork panel in an alternatively fast and simple manner.

These and other advantages and features of the invention will become evident in view of the drawings and the detailed description of the invention.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows a perspective view of an embodiment of the vertical formwork according to the invention.

Figure 2 shows a second perspective view of the vertical formwork of figure 1 .

Figure 3 shows a section view of the vertical formwork of figure 1 .

Figure 4 shows a first perspective view of the front anchor of the vertical formwork of figure 1 .

Figure 5 shows a second perspective view of the front anchor of figure 4. Figure 6 shows a third perspective view of the front anchor of figure 4.

Figure 7 shows a detailed section view of the front anchor of figure 4. Figure 8 shows a section view of the front anchor of figure 4 fixed to the front formwork panel.

Figure 9 shows a perspective view of the fixing key of the front anchor of figure 4. Figure 10 shows a detailed section view of the front anchor of figure 4 supported against the front formwork panel.

Figure 1 1 shows a detailed section view of the front anchor of figure 4 with the fixing key housed in the hole of the front formwork panel, the fixing key being in the first angular position.

Figure 12 shows a detailed section view of the anchor of figure 4 with the fixing key housed in the hole of the front formwork panel, the fixing key being in the second angular position.

Figure 13 shows a detailed view of the housing of the front anchor of figure 4.

Figure 14 shows a first perspective view of the rear anchor of the vertical formwork of figure 1 .

Figure 15 shows a second perspective view of the rear anchor of figure 14.

Figure 16 shows a third perspective view of the rear anchor of figure 14. Figure 17 shows a fourth perspective view of the front anchor of figure 14.

Figure 18 shows a section view of the rear anchor of figure 14 fixed to the rear formwork panel. Figure 19 shows a perspective view of the fixing key of the rear anchor of figure 14. Figure 20 shows a section view of the rear anchor of figure 14 with the fixing key housed in the hole of the rear formwork panel and the pin housed in the second hole of the rear formwork panel, the fixing key being in the first angular position.

Figure 21 shows a detailed section view of the rear anchor of figure 14 with the fixing key housed in the hole of the rear formwork panel, the fixing key being in the second angular position. Figure 22 shows a detailed view of the housing of the rear anchor of figure 14.

Figure 23 shows a detailed view of the structure of the front formwork panel of the vertical formwork of Figure 1 . Figure 24 shows a detailed view of fixed part of the rear anchor of figure 14.

DETAILED DISCLOSURE OF THE INVENTION Figures 1 to 3 show an embodiment of the vertical formwork 1 according to the invention.

The vertical formwork 1 comprises a front formwork panel 2 and a rear formwork panel 3 arranged facing one another, a front anchor 4 fixed to the front formwork panel 2 and a rear anchor 5 fixed to said the rear formwork panel 3, and a tie rod 6 fixed to the front anchor 4 and to the rear anchor 5.

The vertical formwork 1 of this embodiment is a vertical formwork suitable for being adjusted from one face, i.e., the tie rod 6 can be fixed from one side of the formwork. In systems of this type, the rear anchor 5 is fixed to the rear formwork panel 3 before the front formwork panel 2 and the rear formwork panel 3 are disposed in the concreting position. Once the front formwork panel 2 and the rear formwork panel 3 are positioned in the concreting position, the operator is disposed on the opposite side, fixing the front anchor 4, and fixing the tie rod 6 to the rear anchor 5 and to the front anchor 4. In the context of the invention, the front part will be considered the part where the operator fixing the tie rod 6 it located. Therefore, the formwork panel arranged on the side of the operator is the front formwork panel 2, and the formwork panel facing said front formwork panel 2 is the rear formwork panel 3. Likewise, the anchor fixed to the front formwork panel 2 is the front anchor 4, and the anchor fixed to the rear formwork panel 3 is the rear anchor 5. Furthermore, the inner face 23 and 33 of the formwork panel 2 and 3 will be considered the face suitable for being arranged in contact with the concrete and the outer face 24 and 24 of the formwork panel 2 and 3 will be considered the face opposite the inner face 23 and 33. In this embodiment, the front formwork panel 2 comprises a structure 21 , a board 20 fixed to said structure 21 , and a housing extending from the outer face 24 to the inner face 23. In this embodiment, a bushing 22 is arranged in the housing of the front formwork panel 2. The bushing 22 forms a housing in which part of the front anchor 4 is housed. The bushing 22 has an inlet opening which is arranged flush with the outer face 24 of the front formwork panel 2, and an outlet opening 220 which is arranged flush with the inner face 23 of the front formwork panel 2, the diameter of the outlet opening 220 being smaller than the diameter of the inlet opening.

In this embodiment the configuration of the rear formwork panel 3 is the same as that of the front formwork panel 2.

In other embodiments, depending on the dimensions of the formwork panel, each formwork panel can comprise a plurality of housings, a respective bushing and anchor being arranged in each of them, such that two facing formwork panels can be fixed to one another through a plurality of tie rods fixed to said anchors.

As mentioned above, the vertical formwork 1 comprises a front anchor 4 suitable for being fixed to the front formwork panel 2 and a rear anchor 5 for being fixed to rear formwork panel 3.

The front anchor 4 of this embodiment, shown in detail in the figures 4 to 6, comprises a housing 400 suitable for receiving a first end of the tie rod 6. The front anchor 4 further comprises a fixed part 44 suitable for being fixed to the front formwork panel 2 and fixing means for fixing said fixed part 44 to the front formwork panel 2. ln this embodiment, the fixed part 44 of the front anchor 4 is supported on a supporting wall 25 of the front formwork panel 2. The fixing means comprise a fixing key 46 suitable for being housed in a hole 210 of the supporting wall 25 of the front formwork panel 2. The fixing key 46 has the function that the screw has in anchors known in the prior art.

The fixing key 46 comprises an off-centered stop 460 with respect to the axis of rotation 464 of the fixing key 46, such that in a first angular position, shown in detail in figures 10 and 1 1 , the off-centered stop 460 of the fixing key 46 can be introduced in the hole 210 of the supporting wall 25 of the front formwork panel 2, and in a second angular position, shown in detail in figure 12, the off-centered stop 460 is retained by the supporting wall 25 of the front formwork panel 2 and therefore the front anchor 4 is fixed to the front formwork panel 2. The hole 210 of the supporting wall 25 of the front formwork panel 2 has a diameter greater than or equal to the diameter of the off-centered stop 460 of the fixing key 46.

In this embodiment, the fixed part 44 of the front anchor 4 comprises a fixing housing 48, shown in detail in figure 13, in which the fixing key 46 is arranged.

In this embodiment, when the fixing key 46 is introduced in the hole 210 of the supporting wall 25 of the front formwork panel 2, in the first angular position, there is a gap between the supporting face 460a of the off-centered stop 460 of the fixing key 46 and the inner face 25a of the supporting wall 25 of the structure 21 of front the formwork panel 2, as shown in figure 1 1 . To eliminate said gap, the fixing means comprise backward motion means cooperating with the fixing key 46, such that when the fixing key 46 turns from the first angular position to the second angular position, the backward motion means make the fixing key 46 axially move backwards and therefore makes the fixing key 46 to be supported against the supporting wall 25 of the front formwork panel 2 in the second angular position, i.e., the supporting face 460a of the off-centered stop 460 of the fixing key 46 is supported against the inner face 25a of the supporting wall 25 of the structure 21 of the front formwork panel 2. In this embodiment, the backward motion means comprise a guide surface 480 arranged in the housing 48 of the fixed part 44, and the fixing key 46 comprises a stop surface 461 , said guide surface 480 and said stop surface 461 cooperating such that the fixing key 46 moves backwards when turning. In this embodiment, the guide surface 480 and the stop surface 461 are helical surfaces. Once the key is turned from the first angular position to the second angular position, the static friction force between the guide surface 480 of the housing 48 and the stop surface 461 of the fixing key 46 is such that the fixing key 46 is maintained in the second angular position. In other possible embodiments, the backward motion means may not be necessary and simply by turning the fixing key, the supporting face of the off-centered stop of the fixing key is supported against the inner face of the supporting wall of the structure of the formwork panel. In other possible embodiments, the fixed part can comprise blocking means configured to retain the fixing key when said fixing key is in the second angular position, so that an involuntary turning of the fixing key is avoided.

In this embodiment, the fixing key 46, shown in detail in figure 9, comprises a shank 462, a first end of said shank 462 being fixed to the stop surface 461 and a second end of said shank 462 being fixed to the off-centered stop 460. The fixing key 46 also comprises a handle 463 after the stop surface 461 . The handle 463 of the fixing key 46 projects from the fixing housing 48 of the fixed part 44 such that the operator can comfortably operate the fixing key 46.

In this embodiment, the fixing housing 48 of the fixed part 44 comprises a retaining element 481 that prevents the fixing key 46 from being separated from said fixing housing 48. The fixing housing 48 comprises a prolongation 482 after the guide surface 480, the retaining element 481 being arranged in said prolongation 482. In this embodiment, the retaining element 480 is a shaft that is transversely arranged in said prolongation 482. The retaining element 481 makes it impossible to lose the fixing key 46 with respect to the front anchor 4, and therefore makes the operator's job easier. In other embodiments, the housing can comprise retaining element of other types that prevent the fixing key from being separated from said housing.

As seen in figures 10 to 12, in this embodiment, the retaining element 481 is arranged in the prolongation 482 such that it allows the off-centered stop 460 of the fixing key 46 to be housed entirely inside the prolongation 482 without projecting from the inner face 441 of the fixed part 44 of the front anchor 4, as it can be seen in figures 6 and 10.

The fact that the fixing key 46 does not project from the inner face 441 of the fixed part 44 of the front anchor 4 makes it easier to assemble the front anchor 4, since the operator can bring the front anchor 4 closer until it is supported on the front formwork panel 2, and then introduce and turn the fixing key 46 in the hole 210 of the front formwork panel 2 for fixing the front anchor 4 to said front formwork panel 2. Otherwise the operator has to fix a threaded end 60 of the tie rod 6 to the rear anchor 5 and in the same time dispose de fixing key 46 in the first angular position so it can enter in the hole 210 of the supporting wall 25 of the front formwork panel 2.

In this embodiment, the prolongation 482 of the fixing housing 48 and the off- centered stop 460 are cylindrical. The diameter of the prolongation 482 is the same as the diameter of the off-centered stop 460. It is thereby achieved that the supporting face 460a of the off-centered stop 460 of the fixing key 46 that is supported on the inner face 25a of the supporting wall 25 of the structure 21 of the front formwork panel 2 is maximum. In other embodiments, the diameter of the prolongation 482 could be greater than the diameter of the off-centered stop 460.

In this embodiment, the shank 462 of the fixing key 46 is also cylindrical. The diameter of the shank 462 is less than the diameter of the off-centered stop 460. The diameter of the shank 462 has to be smaller than the gap located between the retaining element 481 and the wall of the prolongation 482 of the fixing housing 48 so that the fixing key 46 can turn correctly between the first and second angular positions and vice versa.

In this embodiment, in addition to the fixing key 46, the fixed part 44 comprises a pin 47 suitable for being housed in a second hole 21 1 of the front formwork panel 2. The pin 47 projects from the inner face 441 of the fixed part 44. The supporting wall 25 of the front formwork panel 2 comprises a second hole 21 1 in which said pin 47 can be housed. Therefore, when the pin 47 is housed in the second hole 21 1 of the supporting wall 25 of the front formwork panel 2, it collaborates in fixing the front anchor 4. It specifically prevents the front anchor 4 from being able to rotate with respect to the corresponding front formwork panel 2. Figure 23 shows the holes 210 and 21 1 of the supporting wall 25 of the front formwork panel 2 in which the front anchor 4 is fixed.

In other possible embodiments, the front anchor 4 can comprise other ways of assuring that the front anchor 4 does not rotate with respect to the front formwork panel 2. For example, the front anchor 4 can comprise two pins projecting from the inner face of the fixed part and cooperating with two opposite ends of a profile of the structure of the front formwork panel in which the front anchor is fixed. In another possible embodiment, the front anchor 4 could comprise two fixing keys having the features described above, each of said fixing keys being housed in a respective hole of the front formwork panel 2.

In this embodiment, the fixed part 44 of the front anchor 4 comprises a spherical part with an opening. The front anchor 4 also comprises a body 45 which is arranged in the opening of the spherical part of the fixed part 44. The body 45 comprises a first part having a spherically-shaped support wall coupled like a ball and socket joint to the spherical part of the fixed part 44, and a tubular extension after said first part.

In this embodiment, the body 45 of the front anchor 4 comprises the housing 400 of the front anchor 4.

As mentioned above, the first part of the body 45 has clearance like a ball and socket joint with the spherical part of the fixed part 44 in which said body 45 is arranged. This assures that when the outlet openings 220 and 320 of the bushings 22 and 32 of the front formwork panel 2 and the rear formwork panel 3 are not altogether aligned and therefore the tie rod 6 is arranged obliquely, the support wall of the body 45 is supported in its entirety on the fixed part 44.

The rear anchor 5 of this embodiment, shown in detail in the figures 14 to 17, comprises a housing 510 suitable for receiving a second end 60 of the tie rod 6, particularly a threaded end of the tie rod 6.

The rear anchor 5 further comprises a fixed part 50 suitable for being fixed to a supporting wall 35 of the rear formwork panel 3 and fixing means for fixing said fixed part 50 to the supporting wall 35 of the rear formwork panel 3.

In this embodiment, the fixed part 50 of the rear anchor 5 is supported on a supporting wall 35 of the rear formwork panel 3. The fixing means comprise a fixing key 56 suitable for being housed in a hole 310 of the supporting wall 35 of the rear formwork panel 3. The fixing key 56 has the function that the screw has in anchors known in the prior art.

The fixing key 56 comprises an off-centered stop 560 with respect to the axis of rotation 564 of the fixing key 56, such that in a first angular position, shown in detail in the figure 20, the off-centered stop 560 of the fixing key 56 can be introduced in the hole 310 of the supporting wall 35 of the rear formwork panel 3, and in a second angular position, shown in detail in figures 18 and 21 , the off-centered stop 560 is retained by the rear formwork panel 3 and therefore the rear anchor 5 is fixed to the supporting wall 35 of the rear formwork panel 3. The hole 310 of the rear formwork panel 3 has a diameter greater than or equal to the diameter of the off-centered stop 560 of the fixing key 56.

In this embodiment, the fixed part 50 of the front anchor 5 comprises a fixing housing 58, shown in detail in figure 22, in which the fixing key 56 is arranged.

In this embodiment, the fixed part 50 comprises blocking means configured to retain the fixing key 56 when said fixing key is in the second angular position, so that an involuntary turning of the fixing key 56 is avoided.

In this embodiment, fixing key 56 comprises a handle 563 which projects from the fixing housing 58 of the fixed part 50 such that the operator can comfortably operate the fixing key 56. Figure 14 shows the position of the handle when the fixing key 56 is in the first angular position, and figures 15 and 16 show the position of the handle 563 when the fixing key 56 is in the second angular position. In this embodiment, the blocking means comprise a blocking element 59 comprising a stop member 590 configured to block the handle 563 of the fixing key 56 when said stop member 590 is arranged in a blocking position and the fixing key 56 is disposed in the second angular position, as it can be seen in figure 15.

In this embodiment, the blocking element 59 is coupled movably to the fixed part 50 of the rear anchor 5. Preferably the blocking element 59 is coupled to the fixed part 50 of the rear anchor 5 by means of elastic means, said elastic means pushing the stop member 590 to the blocking position. In this embodiment, the elastic means comprise a spring 591 shown in figure 24. Said spring maintains the stop member 590 in the blocking position. If the blocking element 59 is pulled, as it can be seen in 16, the handle 563 of the fixing key 56 can be turned back to the first angular position. Thanks to the blocking element 59, two simultaneous movements are needed to turn back the fixing key 56 from the second angular position to the first angular position. First, the blocking element 59 has to be pulled, and maintaining the blocking element 59 pulled, the fixing key 56 has to be turned back.

In other possible embodiments the stop member 590 can be maintained in the blocking position by other means, for example a magnet.

In this embodiment, in addition to the fixing key 56, the fixed part 50 comprises a pin 57 suitable for being housed in a second hole 31 1 of the supporting wall 35 of the rear formwork panel 3. The pin 57 projects from the inner face 501 of the fixed part 50. The supporting wall 35 of the rear formwork panel 3 comprises a second hole 31 1 in which said pin 57 can be housed. Therefore, when the pin 57 is housed in the second hole 31 1 of the rear formwork panel 3, it collaborates in fixing the rear anchor 5. It specifically prevents the rear anchor 5 from being able to rotate with respect to the corresponding rear formwork panel 5.

In other possible embodiments, the rear anchor can comprise other ways of assuring that the rear anchor does not rotate with respect to the rear formwork panel. For example, the rear anchor can comprise two pins projecting from the inner face of the fixed part and cooperating with two opposite ends of a profile of the structure of the rear formwork panel in which the front anchor is fixed. In this embodiment, in order to achieve a better fixing of the rear anchor 5 to the rear formwork panel 3, the pin 57 in addition to avoid the rotation of the rear anchor 5, it is also fixed to the supporting wall 35 of the rear formwork panel 3 when the fixing key 56 is disposed in the second angular position. When the operator working from the front side of the vertical formwork 1 wants to fix the threaded end 60 of the tie rod 6 in the rear anchor 5 can bang said rear anchor 5 so it is important to achieve a good fixing of the rear anchor 5 to the rear formwork panel 3. In this embodiment the pin 57 comprises a lateral groove 570. When the fixing key 56 is disposed in the first angular position there is a gap between the groove 570 of the pin 57 and the supporting wall 35 of the rear the formwork panel 3, as it can be seen in figure 20. To eliminate said gap, the anchor 5 is configured to move upward when the fixing key 56 turns from the first angular position to the second angular position, the supporting wall 35 entering the groove 570 of the pin 57 when the anchor 5 moves upward, said pin 57 being retained by said supporting wall 35 when the fixing key 56 is in said second angular position.

In this embodiment the fixing key 56 comprises a cam 561. The hole 310 of the supporting wall 35 is traversed by said cam 561 of the fixing key, said cam 561 resting on a supporting surface 313 of the hole 310 of the supporting wall 35. The supporting surface 313 is part of the opening that defines the hole 313 of the supporting wall 35 where the fixing key 56 is housed. As it can be seen in figures 20 and 21 , the distance D from the axis of rotation 564 of the fixing key 56 to said supporting surface 313 is greater when said fixing key 56 is in the second angular position than the distance d from said axis of rotation 564 to said supporting surface 313 when the fixing key 56 is in the first angular position.

In this embodiment, the cam 561 of the fixing key 56 is arranged between the off- centered stop 560 and a substantially cylindrical part 562 of the fixing key 56. The axis of said cylindrical part 562 is the axis of rotation 564 of said fixing key 56. The cylindrical part 562 is housed in the fixing housing 58 of the fixed part 50.

In this embodiment, the rear anchor 5 comprises a nut 51 comprising the housing 510 of the rear anchor 5. The nut 51 can be oriented with respect to the fixed part 50, such that if the outlet openings 220 and 230 of the bushings 22 and 32 of the front formwork panel 2 and the rear formwork panel 3 are not altogether aligned and therefore the tie rod 6 is arranged obliquely, the nut 51 can adapt its orientation to fix the second end 61 of the tie rod 6.

In this embodiment, the rear anchor 5 comprises a lid 54 coupled removable to the fixed part 50. When the lid 54 is coupled to the fixed part 50, the lid 54 prevents the fixing key 56 from being separated from the fixing housing 58 of the fixed part 50 as it can be seen in figures 20 and 21 , so that makes it impossible to lose the fixing key 56 with respect to the rear anchor 5, and therefore makes the operator's job easier.

In other possible embodiments, not shown in the figures, the fixing means of the rear anchor can be the same of the fixing means of the front anchor described in this document.

In other possible embodiments, not shown in the figures, the fixing means of the front anchor can be the same of the fixing means of the rear anchor described in this document.