A gate construction and a method for making the same
The present invention relates to a gate construction or similar closure element capable of movable actuation, which consists of a frame made of a metallic material and having a bottom beam, side ends, an attachment element connected to the ends and concealing bars, panels or other concealing devices along the gate. Major problems are encountered in conjunction with gates, doors and other closure elements, which are supported at their one end, due to the considerable dead weight of the gate and the effect of snow, wind and water, by which the free end of the gate is caused to flex downwards. Apart from the fact that the gate assumes a noticeably unaesthetic appearance as a consequence of this, problems arise in conjunction with the need to support the gate at a considerable distance from the ground in order to prevent the gate from striking the ground in conjunction with the displacement or swinging of the same. The majority of doors and other gates have customarily been manufactured from steel, in conjunction with which individual elements are welded together to form a finished gate leaf, and in conjunction with which all constituent parts of the gate, thanks to their welded assembly, contribute to the reduction of flexure.
However, a gate manufactured in this way is still not sufficiently rigid to prevent the gate from being caused to flex downwards quite considerably in spite of everything, in conjunction with which the functional problem as well as the aesthetic problem remain, especially in the case of long, cantilever gates. In order to prevent such downward flexing,
gates are traditionally constructed according to two principles. The first principle is based on causing all the constituent elements of the gate to be tensioned in a fixture and, with the help preferably of hydraulic jacks, on imparting elastic deformation to the bottom beam and the top beam before welding together the vertical struts that are inserted between the aforementioned two beams or other constituent elements of the gate. The jacks are released once all the elements of the gate have been welded together, when a pre-stressed gate with an inherent banana form will have been obtained. This requires access to relatively large welding fixtures and jigs with built- in jack equipment.
The second principle is based on causing all the elements of the gate to be welded together beforehand in accordance with a certain pattern, and then causing the gate to be tensioned into the desired banana form. It is possible in this case to position all the vertical bars with a small inclined angle, so that they adopt the right vertical orientation when the gate is finally tensioned. In order to achieve tensioning, an inclined stay can be arranged between the free end of the top beam of the gate and an extended part of the bottom beam projecting laterally from the gate. The aforementioned inclined stay is thus caused to be tensioned, after which the desired tensioning of the gate with slight upward deflection of the bottom beam at its opposite free end is obtained, and all the vertical struts accordingly assume an essentially vertical extent or are at least perceived as being vertical. The possibility is also provided for arranging such pre-tensioning by causing such inclined stays to be arranged along the longitudinal extent of the gate itself between its vertical side ends. It is wished to avoid this, however, in
order to prevent them from being used as an aid to climbing in order to facilitate passing over the gate without permission.
Special fixtures are required in conjunction with this as well as great accuracy and skill when manufacturing the gate, together with the associated major inconvenience that the entire gate construction requires to be in a tensioned state. The construction can be likened to an inferior variant of a so- called lattice structure. The conventional method of manufacturing gates is to cause the gate to be manufactured from steel. Steel in itself is a material with a high modulus of elasticity, which means that it exhibits a small tendency to downward bending flexure. The longer the gate leaf, however, the greater the dimension of the bottom beam that must be used.
Many of the gates that are currently being manufactured are produced from aluminium material. Aluminium exhibits a lower modulus of elasticity than steel, and this means that the material has a greater tendency to downward bending flexure. The reason why aluminium is used in spite of this is that the material offers greater possibilities for gates of different designs, and today's market accordingly has a large number of gates which exhibit their own unique designed forms and profiles.
Previously disclosed through EP-A-0128248 Heras and EP-B1-0513554 Tiess, among others, are gates in which a horizontal structural beam situated at the bottom is stiffened by additional means in the form of a cable or a bar which is tensioned internally in the aforementioned structural beam. This means that the gate must be dimensioned to accommodate the aforementioned tensioning means in order to achieve the aforementioned tensioning and pre-tensioned form so that the tendency to downward bending flexure is overcome.
Also previously disclosed through EP-B1-0761926 Rattink and EP-B1-0628698 Rulgrok, among others, are gates which permit an upper part of pairs of beam components in a bottom beam to absorb most of the load on the gate. The aforementioned construction also requires pre-tensioning and a lot of additional material, for example in order to achieve locking by the attachment of plates or other components by welding, screwing or other means of fixing, which pre-tensioning is also maintained by the fixing of extra reinforcement for the entire length of the bottom beam on its upper surface or lower surface, for example by means of screws and nuts or sheet material supported by the beam in question on its upper surface or on the sides of the bottom beam in order to achieve the desired preforming of the bottom beam with an upward-deflected "banana form".
The principal object of the present invention is thus, in the first instance, to solve the aforementioned problems by bringing about the desired pre-forming and also permanent forming of the bottom beam in a gate made of a metallic material solely with the help of the normal constituent parts of the gate without the need to incorporate a large number of tensioning means or reinforcing elements in accordance with previous solutions .
The aforementioned object is achieved by means of a gate construction in accordance with the present invention, which is characterized essentially in that the side ends are attached to the bottom beam in such a way that the latter is caused to be tensioned through the actuation, by the side ends, of an attachment element connected to the side ends at a distance from the attachment points between the bottom beam and the side ends, in that the bottom beam is pre-tensioned in this
way, and in that downward bending flexure of the gate is counteracted.
A further object of the invention is thus to bring about a method which permits the simple and cost-effective manufacture of gates in accordance with the foregoing description.
The aforementioned further object is achieved by means of a method in accordance with the present invention, which is characterized essentially in that between the side ends, which have been attached to the bottom beam at its respective ends facing in a direction away from one another in the form of rigidly functioning elements, an attachment element is caused to be connected and tensioned at a distance from the attachment points between the bottom beam and the side ends so that the downward bending flexure of the gate is counteracted in this way.
The invention is described below as a number of preferred illustrative examples, which are shown in the accompanying drawings, in which: Fig. 1 shows in perspective an actual embodiment of a gate leaf in accordance with the invention;
Figs . 2 - 2B show a plan view, an end view and a perspective view of a gate in accordance with the invention;
Fig. 3 shows a plan view of a bottom beam and side ends in an assembly phase of the gate leaf;
Fig. 3A shows a plan view of the assembly of a gate leaf;
Fig. 3B shows schematically the constituent components of a gate leaf after final assembly; Figs. 4 and 4A show alternative solutions for side ends in a gate leaf;
Fig. 5 shows an example of a constituent roller drive device for a gate leaf in accordance with the invention;
Fig. 6 shows an example of the attachment of a side end to a bottom beam; Figs. 7 and 8 show further examples of the attachment of a side end to a bottom beam;
Fig. 9 shows an example of the attachment of an upper attachment element to a side end during the assembly phase; and Fig. 10 shows a side end and an upper attachment element in position after final assembly.
A gate construction 1 or some other similar closure element capable of movable actuation, which consists of a fully or at least partially fully enclosing frame 2 made of a metallic material, having a bottom beam 3, side ends 4, 5, an attachment element 6 connected to the ends 4, 5 and concealing bars, panels or other concealing devices 7 along the gate 1, solves the problem of bringing about a pre-tensioned bottom beam in a special way in accordance with the present invention. More specifically, the invention comprises a solution in which the side ends 4, 5 are attached to the bottom beam 3 in such a way that the latter is caused to be tensioned through the actuation by the side ends 4, 5 of an attachment element 6 connected to the side ends 4, 5 at a distance A from the attachment points 8, 9 between the bottom beam 3 and the side ends 4, 5, so that the bottom beam is pre-tensioned in this way and downward bending flexure of the gate 1 is counteracted.
In accordance with the invention, the aforementioned attachment element is formed by a single common rigid or flexible tensile element 6. A preferred tensile element is formed by a rigid top beam 6, which extends between both of
the respective side ends 4, 5 of the gate at their respective upper ends 10, 11, and which runs essentially parallel with the bottom beam. The bottom beam 3 and the top beam 6 exhibit essentially identical distances between the side ends 4, 5 in the horizontal direction.
At the respective lower end 12, 13 of the side ends 4, 5, the bottom beam 3 is attached to its respective end 16, 17 facing in a direction away from one another 14, 15 in the form of rigid attachments 18, 19. In the case of loose attachment, the side ends 4, 5 are detachably attached to the bottom beam 3, for example by means of screws 20. A further example of the detachable attachment of the side ends 4, 5 to the bottom beam 3 is to cause the attachment elements 21, which are intended for detachable attachment of the side ends 4, 5 to the respective ends 16, 17 of the bottom beam 3 facing in a direction away from one another 14, 15 and are accommodated in a cavity 22 in the aforementioned bottom beam 3, to be formed by component parts that are suitable for the purpose, for example tensioning parts 21A, 21B in the form of expanders as illustrated in Fig. 3, or by an insert 21 capable of being accommodated in the aforementioned cavity 22, for example as shown in Fig. 6.
In the case of rigid attachment of the side ends 4, 5 to the bottom beam 3, these may be welded to one another. In accordance with the illustrative example of the invention shown in the drawings in Figs. 3-3B and 4-4A, the side ends 4, 5 may be attached to the bottom beam 3 in a slightly outward-angled condition, i.e. the angle V between them is greater than 90°, as shown in Figs. 3 and 3A and Fig. 4. The aforementioned angle V is identical after activation of the attachment element 6, e.g. by bolting the rigid side ends 4, 5
securely, for example to the top beam 6, so that pre-tensioning of the important bottom beam 3 is effected in this way, as shown in Figs. 3B and 4A. The angle x between the respective side end 4, 5 and the aforementioned top beam 6 is essentially a right angle, as shown in Figs. 3B and 4A.
In accordance with the embodiment of a gate construction shown in Figs. 4-4A, the side ends 4, 5 are so arranged as to be attached to the bottom beam 3, and the side of the ends connected to the attachment element is in a slightly angled condition in relation to a plumb-line, and they are brought into an essentially vertical condition in conjunction with their attachment to the upper attachment element 6.
Alternatively, the bottom beam 3 can be preformed before pre-tensioning of the gate frame with the top beam 6, etc.
The aforementioned bottom beam 3 may be whole 3C or divided 3A, 3B.
Illustrated in Figs. 9 and 10 are examples of how the top beam 6 is attached to the side ends 4, 5 by means of a number of bolts 23, which extend through holes 24 in a flange 50 in the respective side end 4, 5, and which are accommodated in such a way as to be capable of being screwed securely into a threaded attachment component 25, which is attached internally in the inner cavity 26 of the top beam. It is possible in this way for a rubber/plastic strip profile 27 attached to the outside of the side end for its entire height to function as protection against crushing and as decoration, as illustrated in Fig. 10.
The advantage of a gate construction in accordance with the present invention, which is particularly suitable for the manufacture of the entire gate, or at least
parts of the gate, in aluminium material, is that after tensioning, the whole of the formed peripheral frame structure 2 contributes to the tensioning process and not, as previously, only during tensioning of the bottom beam, for example as disclosed in the aforementioned EP-A-0128248 and EP-B1-0761926. The attachment point to the side ends 4, 5 for the upper attachment element 6 is thus located higher up than provided by the outer points on the bottom beam 3, which is the case in previously disclosed constructions of such gates. It is possible as a further alternative to cause side ends, which are pre-formed with a slightly curved form, to be attached to a preferably also pre-formed curved bottom beam in accordance with the method described above, whereby these side ends are essentially straight after pre-tensioning of the bottom beam with the help of a longitudinal top beam, although this is not shown in the drawings.
A method of producing a gate construction 1 or some other similar closure element capable of movable actuation, which consists of a frame 2 made of a metallic material, having a bottom beam 3, side ends 4, 5, an attachment element 6 connected to the side ends 4, 5 and concealing bars, panels or other concealing devices 7 along the gate 1, involves causing an attachment element 6 to be tensioned at a distance A from the attachment points 8, 9 between the bottom beam 3 and the side ends 4, 5, which have been attached to the bottom beam 3 at its respective ends 16, 17 facing in a direction away from one another 14, 15 in the form of rigidly functioning elements, so that the bottom beam 3 is pre-tensioned at a force F and the undesired downward bending flexure of the free end 1A of the gate is counteracted in this way.
A rigid top beam 6 is preferably caused to be connected as an attachment element, and each of its respective ends is then connected to its own side end 4, 5 by means of attachment elements, for example by means of bolts or with other attachment means that are suitable for the purpose.
The drawings in Figs. 3A and 3B illustrate how a formed gate construction 1 is supported in such a way as to be capable of displacement in its longitudinal direction 14, 15 with the help of wheels 51 or other rolling devices to enable it to be displaced and, if required, mechanically driven in the desired direction in conjunction with the opening and closing of a gate opening in question by means of the gate construction 1. Fig. 3 also shows an example of how a bottom beam 3 can be formed by a divided bottom beam, the component parts 3A, 3B of which are connected together with the help of interjacent connecting means 28, which may be of a similar kind to the tensionable end connecting means 21A, 21B for the attachment of the side ends 4, 5 to the bottom beam 3, 3A, 3B.
The invention is naturally not restricted to the embodiments described above and illustrated in the accompanying drawings. Modifications are possible, in particular with regard to the nature of the different component parts, or by the application of equivalent technology, without departing from the area of protection afforded to the invention as defined in the Patent Claims.