PUSH-PULL PROP

Abstract

A push-pull prop includes inner and outer tubes reversibly fixed to each other, a threaded bar screwed into a threaded portion of a first end of the inner tube, a fixing head including a coupling portion fixable to a first end of the outer tube and a locking portion rotationally connected to the coupling portion, so the outer tube can rotate with respect to the locking portion about a rotation axis to thread the inner tube on the threaded bar. The locking portion is rotationally connected to a first connecting element at a first surface so the prop can rotate about a first tilting axis perpendicular to the rotation axis. The threaded bar is rotationally connected to a second connecting element at a second surface, so the prop can rotate about a second tilting axis perpendicular to the rotation axis and parallel to the first tilting axis.

Claims

1. A push-pull prop comprising: an inner tube and an outer tube which are reversibly fixed to each other, wherein the inner tube is at least partially inserted into the outer tube, a threaded bar at least partially screwed into a threaded portion of a first end of the inner tube, said first end being opposite to a second end of the inner tube inserted into the outer tube, said inner tube, outer tube and threaded bar being arranged coaxially to one another along a common axis of the prop, a fixing head comprising a coupling portion fixed or fixable to a first end of the outer tube, said first end being opposite to a second end of the outer tube adapted to receive the inner tube, and a locking portion rotationally connected to said coupling portion, so that said outer tube can rotate with respect to said locking portion about a rotation axis of the outer tube coinciding with the common axis of the prop in order to screw or unscrew said inner tube on or from said threaded bar, said locking portion of the prop being further configured to rotationally connect to a first connecting element of the prop at a first surface to be propped, so that the prop can rotate about a first tilting axis of the prop perpendicular to the rotation axis of the outer tube; wherein said threaded bar is configured to rotationally connect to a second connecting element of the prop at a second surface to be propped, so that the prop can rotate about a second tilting axis of the prop perpendicular to the rotation axis of the outer tube and parallel to the first tilting axis of the prop; wherein said fixing head comprises: an antifriction sliding element in the shape of a solid material ring, interposed between the coupling portion and the locking portion, and a retaining element of the antifriction sliding element between the coupling portion and the locking portion.

2. The push-pull prop according to claim 1, wherein said antifriction sliding element is a bronze ring operating as a bushing and wherein said retaining element is a screw.

3. The push-pull prop according to claim 1, wherein the coupling portion and the locking portion have respective ring-shaped housing seats mutually facing and spaced apart to accommodate the anti-friction sliding element.

4. The push-pull prop according to claim 1, wherein the is defined by a substantially cylindrical solid body having a through hole in which the retaining element is inserted or insertable.

5. The push-pull prop according to claim 1, wherein said coupling portion is inserted at least partially into the first end of the outer tube.

6. The push-pull prop according to claim 1, wherein said threaded portion of the first end of the inner tube is a threaded bushing fixed or fixable inside the inner tube.

7. The push-pull prop according to claim 1, wherein said locking portion has a respective connection slot adapted to receive a first connecting pin of the prop with the first connecting element along the first tilting axis of the prop, and wherein said threaded bar has a respective connection slot adapted to receive a second connecting pin of the prop with the second connecting element along the second tilting axis of the prop.

8. The push-pull prop according to claim 1, comprising a locking pin passing through the inner tube and the outer tube at an overlapping zone of the inner tube and outer tube to prevent the reciprocal movement thereof.

9. A kit for installing a push-pull prop comprising: a push-pull prop according to claim 1, wherein said locking portion and said threaded bar have respective connection slots, a first and a second connecting element which can be fixed to a first and a second surface to be propped, respectively, and having respective through holes which can be coupled to said connection slots, a first and a second connecting pin which can be inserted through said connection slots and said through holes, respectively, to be arranged along said first and second tilting axes of the prop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a diagrammatic perspective view of a push-pull prop according to the present invention, during a configuration of use.

[0035] FIG. 2 is a diagrammatic section of the push-pull prop shown in FIG. 1.

[0036] FIGS. 3 and 3A show a diagrammatic cross-section and an exploded perspective view, respectively, of a fixing head of the push-pull prop of the present invention as shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0037] With reference to the accompanying figures, a push-pull prop is indicated by reference numeral 1 as a whole, henceforth simply referred to as prop 1.

[0038] As shown in FIG. 1, the prop 1 is configured to be arranged inclined between two surfaces S1, S2 to be propped (e.g., two perpendicular surfaces, in the case of soil/floor/slab S2 and wall S2).

[0039] The prop 1 comprises an inner tube 2 and an outer tube 3 which are reversibly fixed to each other, where the inner tube 2 is at least partially inserted into the outer tube 3.

[0040] Preferably, the prop 1 comprises a locking pin 4 passing through the inner tube 2 and the outer tube 3 at an overlapping zone of the inner tube 2 and outer tube 3 to prevent the reciprocal movement thereof.

[0041] In other words, the inner tube 2 is fixed to the outer tube 3 by inserting the locking pin 4 into respective through-holes 5a, 5b of the tubes 2, 3 so that the two tubes 2, 3, when constrained by the locking pin 4, are integral in movement.

[0042] The first adjustment of the prop 1, i.e. the “rough” one, can thus be carried out by the operator by causing the inner tube 2 to slide into the outer tube 3, selecting and aligning the through-holes 5a, 5b, and inserting the locking pin 4 so as to lock the tubes 2, 3 at the desired length.

[0043] The prop 1 then comprises a threaded bar 6 at least partially screwed into a threaded portion of a first end 2a of the inner tube 2, opposite to a second end 2b of the inner tube 2 inserted into the outer tube 3.

[0044] In other words, the inner tube 2 is screwable onto the threaded bar 6 (and therefore even onto the outer tube 3 when constrained by the inserted locking pin 4), and the inner tube 2 is interposed between the threaded bar 6 and the outer tube 3.

[0045] Preferably, with reference to FIG. 2, the threaded portion of the first end 2a of the inner tube 2 is a threaded bushing 2a′ fixed or fixable inside the inner tube 2. Therefore, the threaded bar 6 is threaded specifically to be screwed into the threaded bushing 2a′.

[0046] In particular, the inner tube 2, outer tube 3 and threaded bar 6 are arranged coaxially to one another along a common axis A of the prop 1.

[0047] Typically, the common axis A lies on a plane perpendicular to the surfaces S1, S2 to ensure proper placement of the prop, thus substantially defining the inclination angle of the prop 1 with respect to the surfaces S1, S2.

[0048] The prop 1 of the present invention comprises a fixing head 7. The fixing head 7 comprises a coupling portion 8 and a locking portion 9.

[0049] The coupling portion 8 is either fixed or fixable to a first end 3a of the outer tube 3, opposite to a second end 3b of the outer tube 3 adapted to receive the inner tube 2.

[0050] Preferably, the coupling portion 8 is fixed to the first end 3a of the outer tube 3 by means of a plurality of screws 10, shown in FIG. 2, passing through the outer tube 3 and insertable into corresponding holes 12 of the coupling portion 8, shown in FIGS. 3 and 3A.

[0051] Furthermore, with reference to FIG. 2, the coupling portion 8 is preferably inserted, in use, at least partially into the first end 3a of the outer tube 3. In other words, the first end 3a of the outer tube 3 is fitted onto the coupling portion 8.

[0052] With reference to FIGS. 3 and 3A, even more preferably, the coupling portion 8 comprises a raised peripheral ring 8a against which the edge of the first end 3a of the outer tube 3 abuts, as shown in FIG. 2.

[0053] Advantageously, the locking portion 9 is rotationally connected in use to the coupling portion 8, so that the outer tube 3 (and thus even the inner tube 2 fixed thereto) can rotate (as indicated by arrow F1 in FIG. 2) with respect to the locking portion 9 about a rotation axis R of the outer tube 3 coincident with the common axis A of the prop 1 to screw or unscrew the inner tube 2 on the threaded rod 6 by increasing or decreasing the longitudinal extension of the prop 1.

[0054] Indeed, screwing or unscrewing the inner tube 2 on the threaded bar 6 at the threaded portion allows the threaded bar 6 and the outer tube 3 to be moved closer or further apart (as indicated by arrow F2 in FIG. 2) to finely adjust the compression/pulling of the prop 1 on the surfaces S1, S2.

[0055] It is worth noting that in the prop 1 according to the present invention, the threaded rod 6 and the locking portion 9 remain fixed with respect to the rotation of the “coupling portion 8-outer tube 3-inner tube 2” system.

[0056] Furthermore, advantageously: [0057] the locking portion 9 is configured to rotationally connect to a first connecting element 11 of the prop 1 at the first surface S1 to be propped, so that the prop 1 can rotate about a first tilting axis T1 of the prop 1 perpendicular to the rotation axis R of the outer tube 3, and [0058] the threaded bar 6 is configured to rotationally connect to a second connecting element 12 of the prop 1 at the second surface S2 to be propped, so that the prop 1 can rotate about a second tilting axis T2 of the prop 1 perpendicular to the rotation axis R of the outer tube 3 and parallel to the first tilting axis T1 of the prop 1.

[0059] In other words, the locking portion 9 and the threaded rod 6 can rotate only about the tilting axes T1, T2, respectively, to change the inclination angle of the prop 1 upon the rotation of the outer tube 3.

[0060] In particular, the connecting elements 11 and 12 are fixed or fixable to the respective surfaces S1, S2 and thus remain in a fixed position during the rotation of the rotation axis R and/or the tilting axes T1, T2.

[0061] Preferably, the coupling portion 9 of the fixing head 7 has a respective connection slot 9a adapted to receive a first connecting pin, not shown in the accompanying figures, of the prop 1 with the first connecting element 11 along the first tilting axis T1, and the threaded bar 6 has a respective connection slot 6a adapted to receive a second connecting pin, not shown in the accompanying figures, of the prop 1 with the second connecting element 12 along the second tilting axis T2.

[0062] With particular reference to FIGS. 3 and 3A, the fixing head 7 of the prop 1 of the present invention advantageously comprises: [0063] an anti-friction sliding element 13 in the shape of a solid material ring, e.g. made of bronze, interposed between the coupling portion 8 and the locking portion 9, and [0064] a retaining element 14 configured to retain the anti-friction sliding element 13 between the coupling portion 8 and the locking portion 9.

[0065] In particular, the anti-friction sliding element 13 preferably is a bronze ring operating as a bushing.

[0066] The bronze ring offers excellent resistance and self-lubrication characteristics, whereby it ensures optimal resistance to stresses and an effective guarantee against breakage, thus facilitating the mutual sliding between the coupling portion 8 and the locking portion 9.

[0067] Advantageously, the anti-friction sliding element 13 also allows the coupling portion 8 and the locking portion 9 to be spaced apart so that they are not in contact with each other, i.e., preventing friction during the rotation of the coupling portion 8 with respect to the locking portion 9.

[0068] Indeed, the prop 1 is typically made of metal and the attrition between the coupling portion 8 and the locking portion 9 would make it difficult (if not impossible, considering the working loads to which prop 1 is axially subjected) to rotate the outer tube 3.

[0069] Therefore, the anti-friction sliding element 13 allows obtaining an effective rotation of the coupling portion 8 fixed in use to the outer tube 3, and thus the rotation of the outer tube 3, ensuring an ideal sliding without compromising the robustness and durability of the system.

[0070] Due to the asymmetrical distribution of forces to which prop 1 is subjected, unlike a normal bearing which does not work axially under ideal conditions and is therefore easily subject to breakage, the ring shape made of solid material particularly allows withstanding very high stresses, such as those to which prop 1 is subjected during operation.

[0071] In order to allow the rotation of the “coupling portion 8-outer tube 3-inner tube 2” assembly, considering that neither the locking portion 9 nor the threaded rod 6 can rotate about the rotation axis R (being preferably fixed to the first and second surfaces S1, S2, respectively, by means of the first and second connecting elements 11, 12), a component of the prop 1, namely the fixing head 7, which easily rotates (preferably idle) in a practical and frictionless manner is required.

[0072] Advantageously, the retaining element 14, e.g. a screw, serves the function of keeping the locking portion 9 and the coupling portion 8 coupled while allowing them to slide reciprocally in rotation.

[0073] In particular, as shown in the accompanying figures, the anti-friction sliding element 13 is coaxial to the retaining element 14.

[0074] In other words, the retaining element 14 performs the function of packing the coupling portion 8 and the locking portion 9; in particular, in order to avoid the unscrewing of the retaining element 14, a welding spot can be made after installing it. As an alternative to the screw, a self-locking nut or a pin or a nut provided with a split pin can be used.

[0075] Preferably, the coupling portion 8 and the locking portion 9 have respective ring-shaped housing seats 15 mutually facing and spaced apart to house the anti-friction sliding element 13.

[0076] Advantageously, the anti-friction sliding element 13 is thus confined and protected within the housing seats 15, in which it is free to slide upon the rotation of the outer tube 3.

[0077] With reference to the embodiment shown in the accompanying figures, the coupling portion 8 is preferably defined by a substantially cylindrical solid body having a through-hole 16 in which the retaining element 14 is inserted or insertable.

[0078] In particular, the through-hole 16 extends about the common axis A.

[0079] According to a further aspect of the present invention, a push-pull prop installation kit 100 is provided, comprising: [0080] a push-pull prop 1 according to the present invention, where the locking portion 9 and the threaded bar 6 have respective connection slots 9a, 6a, [0081] a first and a second connecting element 11, 12 which can be fixed to the first and second surfaces S1, S2 to be propped, respectively, and having respective through-holes (not shown in the figures) which can be coupled to the respective connection slots 9a, 6a, [0082] a first and a second connecting pin (not shown in the accompanying figures) which can be inserted through the connection slots 9a, 6a and the through-holes, respectively, to be arranged along the first and second tilting axes T1, T2 of the prop 1.

[0083] It is worth noting that, advantageously, the prop 1 can also be installed backwards, i.e. with the fixing head 7 connected to the second connecting element 12 and with the threaded rod 6 connected to the first connecting element 11.

[0084] The present invention achieves the suggested purposes, overcoming the drawbacks complained of in the prior art and providing the user with a push-pull prop which is particularly efficient, practical in its use, and small in size, and with an installation kit which is simple and quick to install.