CLAMP FOR SECURING ACCESSORY ELEMENTS TO METAL PILLARS

Technical sector of the invention

The invention relates to a clamp for firmly securing accessory elements to metal pillars such as the beams of a building under construction. The invention also relates to a system for fixing to a metal pillar the perch of a safety device for operators, which comprises at least two clamps according to the invention suitably fixed to the same pillar at different heights.

Background of the invention

At present, numerous variations are known of clamps designed to join construction elements, such as shuttering panels, or to secure accessory elements to the metal pillars that form part of the structure of a building under construction.

By way of example, document NL 1023831 C discloses a clamp formed by two telescopically coupled tubular bodies, with each of the tubes fitted with a sidebar or jaw, opposite each other and designed to secure each one the longitudinal edge of the flange of a metal profile. The tubular bodies house a threaded spindle, externally actuated, whose rotation in one or another direction causes the extraction or insertion of the inner tubular body in the outer tubular body, separating or distancing the side bars from each other. For this purpose, the inner tubular body, displaceable, is solidly joined to an inner element, prevented to rotate, coupled by threading to the spindle. Said inner element displaces longitudinally as the spindle rotates and carries the inner tubular body in its displacement. The described clamp is designed to be fixed to horizontal beams and to serve as support for a metal bar, which rests directly on one of the tubular bodies, to form a protective barrier for operators. To this end, the clamp is fitted with a casing opened at the top with a configuration complementing that of the bar, designed to receive the lower end of said bar.

The clamp described above presents certain disadvantages. In first place, the telescopic coupling of the tubular bodies makes opening and closing of the clamp difficult, due to the friction existing between the two tubular bodies. In second place, the clamp is not suitable for fixing to vertical pillars to support heavy accessory elements, since when the clamp is in its maximum opening

position, in other words when the side bars are as distant from each other as possible and when the inner tubular body is almost fully extracted from the outer tubular body, due to the concentration of efforts on the clamp the latter may become deformed in its weakest zone, which is the joining zone between the tubular bodies. At the same time, the clamp in question is not at all versatile since it is specifically designed to receive a bar with a very particular configuration, and cannot be used to support other auxiliary elements whose configuration does not complement that of the clamp's casing. Finally, in the event of any accessory element being introduced in the support element, it cannot guarantee that accidental extraction of the accessory element from inside the support will be prevented especially when the clamp is suspended and transported from one place to another at the works using a crane, which can give rise to serious incidents.

The object of the present invention is a clamp designed to safely secure accessory elements to beams, and in particular to vertical beams or pillars, which improves the resistance of known clamps and which is additionally easily adjustable.

Explanation of the invention The clamp for securing accessory elements to double-flanged metal pillars object of the present invention, is of the type that comprises two tightening jaws mounted opposite each other on a support piece and actuating means to displace at least one of said jaws to open and close the clamp, with the jaws designed to tightly grip, in the clamp's closed operative position, the opposite longitudinal edges of a metal profile's flange. In essence, the clamp is characterized in that the support piece is fitted with solidly joined retaining means displaced to one side, with said retaining means having a vertical axis perforation designed to retain an accessory element that crosses it and/or to hold the support of an accessory element. According to another characteristic of the invention, the retaining means comprise two flat plates essentially horizontal, superimposed at a short distance and having respective circular perforations aligned vertically, with at least one of said plates having at least one notch or projection in its perforation contour.

According to another characteristic of the invention, the notches or projections of one plate are angularly displaced in relation to the respective notches or projections of the other plate.

Another distinguishable aspect of the clamp object of the invention is that the actuating means comprise a threaded rod, by way of a spindle, housed within the support piece provided with a slider, and because one of the jaws is mounted threaded on said spindle, prevented from rotating but longitudinally displaceable throughout the length of the support body's slider , approaching or distancing itself from the other jaw, which is fixed, as it makes the spindle rotate in one direction or another around its axis.

Also object of the present invention is a system for securing accessory elements to a vertical metal pillar, and specifically to support the perch of a safety device for operators, which in essence is characterized in that it comprises a pair of clamps such as the one described in the present invention and a support for the perch consisting of a tubular body provided at its upper mouth with an outwards overhang and at its lower end by support means for one end of the perch, with the clamps designed to be fixed at a certain distance to the same pillar, leaving the perforations of their respective retaining means axially aligned and with the tubular body designed to be introduced through the perforation of the retaining means of the clamp fixed to the pillar at a lower height, and to be supported by the overhang resting on the contour of said perforation, all of the above in such a way that in the mounted position the perch may be introduced through the perforation of the retaining means of the upper clamp until its lower end is introduced and supported in the tubular body held by the lower clamp.

The system is characterized additionally in that the tubular body has on its outer wall corresponding projections or notches that complement the notches or projections on the flat plates of the retaining means.

According to a preferred embodiment, the supporting means comprises a pin that crosses the tubular body.

According to a variant of the invention, at least one of the ends of the pin penetrates the outer surface of the tubular body's side wall constituting a projection with a contour that complements that of the notch or notches provided in the flat plates of the retaining means.

Brief description of the drawings

The attached drawings show, by way of a non-limitative example, a preferred embodiment of the clamp for securing accessory elements to metal pillars object of the invention. In said drawings:

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Fig. 1 is a perspective view, partially sectioned, according to an embodiment of the clamp object of the invention; Fig. 2 is a perspective view, and in the coupled position, of the components of the system according to the invention; and Fig. 3 is a perspective view, in the operative position, of the components of the system according to the invention; Figs. 4 and 5 are respective perspective views of two alternative variations of the tubular body that forms part of the system according to the invention, with the variation of Fig. 4 partially sectioned;

Fig. 6 is a plan view of the clamp of the invention according to another embodiment; and Figs. 7a and 7b are respective schematic plan views of the system of the invention, wherein a perch is retained by different first and second variations respectively, of the clamp according to the invention.

Detailed description of the drawings

Fig. 1 shows the clamp 1 comprising two tightening jaws 2 and 3, wherein jaw 2 is mobile and jaw 3 is fixed, mounted opposite each other on a support piece 4, as well as actuating means 5 through which it is possible to displace the mobile jaw 2 throughout the length of the support piece 4, in one direction or another, to open and close the clamp 1.

One part of the clamp 1 of Fig. 1 has been shown partially sectioned, making it possible to see that the actuating means 5 comprise a threaded rod, in the form of a spindle 12, housed inside the support piece 4 and provided with an external actuating handle 5'. The support piece 4 is additionally provided with a slider 13 through which the mobile jaw 2 slides during its displacement as the clamp 1 is opened or closed. In the example of Fig. 1 , the mobile jaw 2 consists of a paddle 2a, which juts out of the support piece 4 through said slider 13, which is solidly joined to a nut 2b coupled by threading to spindle 12 and prevented from rotating inside support piece 4.

As the spindle 12 is made to rotate around its longitudinal axis by actuating the handle 5', it causes the linear displacement of the nut 2b inside the support piece 4 and the paddle 2a along the slider 13, approaching or distancing itself from the other jaw 3 according to the direction of rotation of the

spindle 12.

Jaws 2 and 3 are designed to tightly grip the opposite longitudinal edges of the flange of a metal profile and for this purpose are arranged slightly inclined in relation to the support piece 4 in order to better adapt to the different thicknesses that the flanges of metal beams usually used in construction may have.

In Fig. 1 it is possible to observe additionally that the support piece 4 of the clamp 1 is provided with solidly joined retaining means 6 displaced to one side of said support piece 4, which are provided with a perforation 7 whose axis is vertically oriented when the clamp 1 is fixed to a metal pillar (see Figs. 2 and 3). Said perforation 7 is designed to be crossed by an accessory element and to prevent its displacement or separation from the clamp 1 in a non-vertical direction, or to hold a support for an accessory element as explained in detail below. In the variation shown in Fig. 1 , the retaining means 6 comprise two flat plates 6a and 6b, arranged in such a way that they are left essentially horizontally oriented when the clamp 1 is fixed to a metal pillar, superimposed at a short distance and fitted with respective perforations 7a and 7b circular and axially aligned, which constitute the perforation 7 of the retaining means 6. Each plate 6a and 6b is fitted with a notch 8a and 8b (see Fig. 2) in the contour 9a and 9b of its perforation 7a and 7b, respectively, with notches 8a and 8b being arranged angularly displaced between them. These notches 8a and 8b constitute safety means that prevent, in collaboration with a corresponding and complementary projection provided to this end in the accessory element to be retained or gripped by the clamp, the accidental separation of said accessory element.

The clamp 1 of Fig. 1 is particularly designed to secure a perch 10 for a safety device for operators to a vertical metal pillar 11. Fig. 2 shows a system 100 consisting of a pair of clamps 1 and 1', according to Fig. 1 , and a tubular body 15 fitted at the mouth of its upper end with an outwards overhang 16 and fitted in its lower end with support means 19 for one end 17 of the perch 10.

To assemble the system 100, as can be seen from Figs. 2 and 3, the clamps 1 and 1 ' are fixed at a certain distance to the same pillar 11 , leaving perforations 7 and T of their respective retaining means 6 and 6' axially aligned. Next, the tubular body 15 is introduced through the perforation 7 of the retaining means 6 of the clamp 1 fixed to the pillar 11 at the lower height,

leaving the tubular body 15 supported by its outwards overhang 16 in the contour of said perforation 7. Once these operations are executed, the perch 10 can be introduced through the perforation T of the retaining means 6' of clamp 1 ', situated at the greater height, until its free end 17 is introduced in the tubular body 15, held by clamp 1 situated at the lower height, and rest on the support means 19 of said tubular body 15.

Fig. 3 shows the system 100 consisting of the two clamps 1 and 1' and the tubular body 15 mounted in its operative position. In said Fig. 3 it can be appreciated that the body of the perch 10 is prevented from moving, in the normal direction to the metal pillar, by the retaining means 6' of the upper clamp 1' and by the retaining means 6 of the lower clamp 1 and that at the same time the free end 17 of the same perch 10 is housed within the tubular body 15, held by the lower clamp 1 , whereon it rests.

The system 100 also comprises safety means to prevent the accidental separation of the lower clamp 1 , from the tubular body 15 that is supported by its overhang 16, in the flat plate 6a of said clamp 1's retaining means. These safety means comprise two parts that cooperate together, with one of them being in clamp 1 and the other in tubular body 15.

Indeed, as shown in Figs. 2 to 5, the tubular body 15 is provided in its outer wall with a projection 18. Preferably, the contour of said projection 18 complements that of notches 8a and 8b of the flat plates 6a and 6b of the retaining means 6 of clamp 1 , in such a way that in order for the full insertion of the tubular body 15 through perforation 7, and specifically through perforations 7a and 7b in this order, tubular body 15 must be suitably rotated so as to make its projection 18 coincide with notch 8a of flat plate 6a, and once the projection 18 has crossed the first perforation 7a the tubular body 15 must be reoriented by rotating it in relation to its axial axis to make the projection 18 once again coincide with the notch 8b of perforation 7b in flat plate 6b and next slide the tubular body 15 in the direction of insertion into said perforation 7b. Finally, when projection 18 has already crossed the second perforation 7b, it is advised to rotate the tubular body once more to misalign said projection 18 in relation to notch 8b before fully inserting the tubular body 15 in the perforation of retaining means 5, until the overhang 16 is left supported on the flat plate 6a.

In order to extract the tubular body 15 completely from perforation 7 of the retaining means 6 the steps described for its insertion must be undone since, otherwise, the projection 18 will prevent the extraction of the tubular body

15 due to the butting of said projection 18 first against the contour 9b of perforation 7b of plate 6b of clamp 1 and next, in the event of the projection crossing perforation 7b, due to butting against the contour 9a of perforation 7a in plate 6a. All of the above makes it very difficult for the tubular body 15 to become completely decoupled in an accidental manner from clamp 1 , since it would be difficult for the precise chain movements required for such decoupling to occur. Thus, in the event of clamp 1 being suspended and transported for example by a crane from one construction location to another, with the tubular body 15 being correctly gripped in the retaining means 6 of clamp 1 , it would be extremely difficult for tubular body 15, to fortuitously rotate until being left in such a position that its projection is aligned with notch δb of the lower plate 6b, to axially displace in the direction of its extraction from perforation 7b, to rotate once more until projection 18 coincides with notch 8a of upper plate 6b and finally to displace axially in the direction of its extraction from perforation 7a.

Figs 4 and 5 show two variations of tubular body 15. According to the variation of Fig. 4, wherein the tubular body 15 has been represented in longitudinal section, the support means 19 is formed by a pin 20 that diametrically crosses the tubular body 15. This pin is essentially cylindrical and is provided at one of its ends with a projection 18 that penetrates the outer surface of the tubular body 15 and that is designed to collaborate with notches 8a and 8b made in the contours 9a and 9b of perforations 7a and 7b respectively, of clamp 1.

The cylindrical configuration of the pin 20 reduces the contact surface, and consequently, the friction between the latter and the free end 17 of the perch that is supported on it, thus favouring the rotation movement of the perch 10 over its longitudinal axis. This fact is particularly relevant for the perches 10 of safety devices for operators, since rotation without obstacles of perch 10 facilitates the movement of the operative over the horizontal work surface. According to the variation of Fig. 5, the support means 19 of the tubular body 15 consist of a narrowing of the section of tubular body 15 that gives rise to an inverted trunk-conical stretch 21 designed to receive the support of end 17 of the perch 10.

According to another non-represented variation of the system, the perforations of the retaining means of the lower clamp is of a lower diameter than that of the upper clamp, with the lower clamp potentially provided with one

or two flat plates with their respective perforations. The diameter of the perforation or perforations of the lower clamp will be less than the diameter of the body of the perch, preventing the letter's passage through the perforation or perforations but allowing the support of the lower end of said perch on the plate or plates that comprise the retaining means of the lower clamp. According to this variation, it is possible to omit the support 15 for the perch, consisting of the tubular body of the variation shown in Fig. 3. In the event of the support end of the perch having a trunk-conical configuration, it is contemplated that when the lower clamp is provided with two plates, the perforations of both plates have a different diameter to allow the outer surface of the end of the perch to be supported on the edges of the two perforations.

In relation to clamps 1 and 1 ' shown in Figs. 2 to 3, it is important to note that these are identical to the clamp shown in Fig. 1 except regarding the situation of the handle 5' for the actuating means 5, in this case to apply a rotation movement. The rotation direction that must be transmitted to the handle 5' for opening or closing the clamp 1 will depend on the direction of advance of the thread of the spindle 12 and the location of handle 5'.

Fig. 6 shows a plan view of a second variation of the clamp according to the invention. Unlike the clamps shown in Figs. 1 to 3, the retaining means 6 and corresponding perforation 7 are not arranged between jaws 2 and 3, but rather are displaced to one end of clamp 101 , beyond the fixed jaw 3.

The location of the retaining means 6 of clamp 101 according to Fig. 6, between the end of the support piece 4 and fixed jaw 3, is particularly advantageous for systems for securing the perch 10 of a safety device for operators when the metal pillar 11 lifts to a height corresponding to more than one floor of a building under construction, during slab concreting works for the lower levels.

Figs. 7a and 7b are schematic plan views of respective safety systems 100 wherein the first one, of Fig. 7a, incorporates clamps 1 according to Figs. 4 and 5; and the second one, of Fig. 7b, incorporates clamps 101 according to the one shown in Fig. 6.

The perches 10 usually used for operators' safety are fitted with an arm or horizontal extension 10', at their upper end, to the end of which using a rope or similar, the safety harness of one or several operators is attached. When the height of the perch 10 is greater than the height of the metal pillars 11 whereto the perch 10 is attached, the latter can rotate around its

longitudinal axis without its horizontal extension 10' abutting against said metal pillar 11 , with the perch able to rotate freely 360° around its longitudinal axis, which offers great freedom of movement to the operative attached to the horizontal extension 10' of said perch. However, when the metal pillars 11 have a height of more than one floor level, during shuttering works of lower levels, the metal pillars 11 exceed in height the perches 10 attached to said metal pillars 11. Consequently, the rotation of the perch 10 around its longitudinal axis is limited by the abutting of its horizontal extension 10' against the metal pillar 11. Fig. 7a reflects this situation and it is possible to see how, once the lower end of the perch 10 is inserted in the corresponding tubular body 15 (not shown), the perch 10 can rotate around its longitudinal axis at an angle of α determined by the situations wherein the horizontal extension 10' abuts against the flange of profile 11 whereto clamps 1 are fixed and with the edge of said flange on the side of the fixed jaw 3 of said clamps 1.

Fig. 7b represents the same situation but with clamps 101 according to Fig. 6. It is possible to observe that once the lower end of the perch 10 is introduced in the corresponding tubular body 15 (not shown), the perch 10 can rotate around its longitudinal axis at an angle β that is greater due to the more distant position occupied by the retaining means 6 in relation to the edge of the metal profile 11 whereto the clamps 101 are fixed, which considerably increases the freedom of movement of the operator or operators attached to the end of horizontal extension 10'.