WO2009008705A1

WO2009008705A1 - Flag structure

Info

Publication number: WO2009008705A1
Application number: PCT/NL2007/050349
Authority: WO
Inventors: Hendrik Jan Heerkes
Original assignee: Hendrik Jan Heerkes
Priority date: 2007-07-12
Filing date: 2007-07-12
Publication date: 2009-01-15
Also published as: EP2171707A1

Abstract

A flag structure (1) comprises a flag (2); and coupling means (3, 4) carrying the flag (2) for the purpose of coupling the flag structure to a support structure such as a vertical flagpole (5). The flag comprises: a frame (8) defining an inflow opening for the wind, two cloths (12), the front edges of which are connected to the frame (8) and the remaining edges of which are at least partially connected to each other; a group of strips (15) which extend over the full height of the flag and which are each connected to the cloths with their two longitudinal edges; and passage means for allowing passage of air blown in via the inflow opening. The flag is hereby tensioned by inflation during operation in wind, and orients itself to the wind in the manner of a weather-vane or a wind-sock.

Description

FLAG STRUCTURE

The invention relates to a flag structure, comprising: a flag; and coupling means carrying the flag for the purpose of coupling the flag structure to a support structure, in particular a substantially vertical flagpole.

A known flag structure comprises a cloth, the front edge of which can be coupled to a flagpole by means of for instance a cord coupled thereto. By means of a raising cord the flag can be raised to its position of use, secured in this position and released therefrom again so as to be removed and stowed away.

The drawback of a known flag is that it only flaps in the case of a substantial wind strength. This is a logical result of the fact that the flag always tends to orient itself in the direction of the wind and is thereby subjected to a very low mechanical load from this wind. When the flag is not flapping however, the information carried by the flag is not visible, or hardly so.

When the wind is relatively strong there soon occurs the phenomenon, due to the known flapping of the flag, that the rear edge of the flag, i.e. the edge remote from the flagpole and the coupling means, makes very strong and violent movements which are closely related to whiplashes. Due to these whiplash effects the fibres at the rear edge of the flag are subjected to extremely heavy tensile stress, whereby such a flag loaded by strong wind tends to start fraying.

It is an object of the invention to embody a flag structure such that the flag is wholly visible on both sides at a relatively low wind strength.

It is a further object of the invention to embody a flag structure such that the flag flaps gently in the wind without any appreciable whiplash effect at the rear edge, whereby the lifespan of the flag is greatly increased.

With a view to the above objectives, the flag structure according to the invention has the feature that the flag comprises: a frame defining an inflow opening for the wind, comprising at least two elongate elements such as slats which, at least during operation in wind, extend at least more or less vertically at a mutual distance; two cloths, the front edges of which are connected to the elongate elements and the remaining edges of which are at least partially connected to each other; a group of strips which extend over the full height of the flag and which are each connected to the cloths with their two longitudinal edges; and passage means for allowing passage with a certain flow resistance of air flowing via the inflow opening into the space bounded by the cloths during operation in wind; which elongate elements are stiff relative to the cloths; and that the coupling means are connected to the frame; this such that the flag is tensioned by inflation during operation in wind, and orients itself to the wind in the manner of a weather-vane or a wind-sock.

The elongate elements forming part of the frame part can advantageously lie in one shared flat plane. The two cloths can be two parts of one cloth folded only once, wherein the fold zone forms the rear edge.

It is technically not absolutely necessary for the elongate elements to be completely straight. Curved shapes, for instance two mutually coupled curved elements placed in mirror symmetry, can also be applied.

The passage means -ensure that the air flowing through the flag tensions the flag in controlled manner and is allowed outward, in particular to the rear, subject to the pressure prevailing in the flag. The passage means can also ensure that sand and dirt do not accumulate in the flag but are discharged outward. In another embodiment the flag structure has the special feature that the frame comprises at least one further elongate element extending at least more or less in transverse direction relative to the above mentioned two elongate elements. During operation in the case of wind this element is placed under tensile stress and for this reason does not have to be stiff. Use can however be made for structural reasons of a relatively stiff element. It is noted that the use of transverse elements can also be wholly dispensed with. This is because during operation in the case of wind the strips fulfill the function of holding at mutual distance the two relatively stiff elements extending substantially vertically.

A certain stiffening and strengthening of the frame can hereby be realized.

It is noted by way of elucidation that the flag according to the invention can have roughly the same dimensions as known flags. These dimensions are for instance a height of 1.5 m x a width of 2.5 m, respectively a width of 1.5 m x a height of 2.5 m, or a height of 2.0 m x a width of 3.5 m, respectively a width of 2.0 m x a height of 3.5 m. It will be apparent that other dimensions and shapes other than rectangular are also possible.

The flag structure can for instance comprise: at least one outflow opening present in the area of the rear edge of the flag. This outflow opening can form part of the rear edge but may also be present in the bottom face or the top face of the flag, close to the rear edge.

In combination with one or more outflow openings, or as an alternative, the flag structure can be embodied such that the cloths are to some extent air-permeable.

This latter embodiment can have the special feature that the cloths are fabrics which are to some extent porous and comprise intersecting threads, the intersections of which are fixed, for instance by a calendering treatment. A very practical choice for the material of the cloths is that in which the cloths consist of parachute fabric.

According to yet another aspect of the invention, the flag structure can have the special feature that the two cloths have mutually differing lengths. This creates an aerodynamic form which turns the flag away from the wind direction as a result of the lift. Because the wind direction and the wind strength always vary slightly, a gently flapping image will hereby result, which improves the visibility of the flag and has the effect of heightening attention.

The strips can be relatively stiff. It is however recommended, particularly for the purpose of a low weight, that the strips consist of a thin and thereby flexible material, or an inherently flexible material.

The strips can for instance consist of cloth material, for instance of the same type as the two cloths. The strips together with the two cloths bound mutually adjacent chambers. In order to ensure that no substantial and greatly varying pressure differences occur between the chambers, which could result in agitated movements of the flag, it is recommended that a certain equalization of pressure can occur between the chambers bounded by the strips. In this respect the flag structure can have the special feature that the strips are to some extent air-permeable.

The strips can thus be provided locally, particularly in the area of the rear edge, with substantial perforations, or end at a distance from the rear edge. Alternatively, the strips themselves can consist of cloth material, which is naturally somewhat air-permeable. The cloths can for instance be fabrics which are to some extent porous and comprise threads with intersections which are fixed, for instance by a calendering treatment.

According to another aspect of the invention, the flag structure has the special feature that at least one of the cloths carries information, for instance an advertising presentation. The two cloths can carry mutually differing information.

Particularly in the case where the flag is intended for co-action with a substantially vertical, cylindrical flagpole, the flag structure can have the special feature that the coupling means comprise two coupling elements, each having a general annular form.

This flag structure can for instance have the special feature that a coupling element comprises two curved jaws which are movable relative to each other between an open position, in which the coupling element can be positioned over the support structure, and a closed position in which the coupling element is coupled to the support structure with a certain mobility relative thereto. Highly suitable is a monolithic ring open on one side and of elastic material, for instance polyamide, also referred to as PA or nylon. Such a ring can be opened while being temporarily elastically deformed, such that the ring can be placed over the flagpole. It closes again due to its own resilience. PA is a material which has a good wear-resistance, has relatively little friction with most materials for flagpoles, in particular aluminium, and is well able to withstand the most varying weather conditions. The invention will now be elucidated with reference to the accompanying drawings . In the drawings : figure 1 shows a side view of a flag structure according to the invention carried by a vertical flagpole; figure 2 shows a transparent perspective view of a first exemplary embodiment of a flag; figure 3 is a partly cut-away, transparent perspective view of another embodiment; figure 4 shows a cross-section through a relatively stiff elongate element and a cloth attached thereto; figure 5 shows a third embodiment with an aerodynamic form; figures 6, 1, 8, 9, 10 and 11 show six random exemplary embodiments of frames as seen in the wind direction; and figure 12 is a perspective view of a part of a flagpole and a frame according to figure 10 co-acting therewith and having two coupling rings.

Functionally corresponding components and elements are always designated in all figures with the same reference numerals.

The figures show a flag structure 1, comprising: a flag 2; and coupling means 3, 4 carrying flag 2 for the purpose of coupling flag structure 1 to a support structure, in particular a substantially vertical flagpole 5.

According to the invention the flag structure 1 has the feature that flag 2 comprises: a frame 8 defining an inflow opening 6 for the wind 7 and comprising at least two elongate elements 9, 10 such as slats which, at least during use in wind, extend at least more or less vertically at a mutual distance; two cloths 11, 12, the front edges 13, 14 of which are connected to elongate elements 9, 10, and the remaining edges of which are at least partially connected to each other; a group of strips 15 which extend over the full height of the flag and which are each connected to cloths 11, 12 with their two longitudinal edges 16, 17; and passage means for allowing passage with a certain flow resistance of air flowing via inflow opening 6 into the space bounded by cloths 11, 12 during operation in wind; which elongate elements 9, 10 are stiff relative to cloths 11, 12; and that coupling means 3, 4 are connected to frame 8; this such that flag structure 1 is tensioned by inflation during operation in wind, and orients itself to the wind in the manner of a weather- vane or a wind-sock.

In the embodiment according to figure 2 the frame 8 (see also figure 10) comprises two further, in this case relatively stiff elongate elements 18, 19 extending in transverse direction relative to the vertical elongate elements 9, 10, whereby the rectangular framework clearly shown in figures 2 and 10 is formed. This framework 9, 18, 10, 19 defines a fixed inflow opening 6 for the wind 7. In the embodiment according to figure 2 the flag 2 has an outflow opening 24 present in the area of rear edge 23, the area of this opening through which flow passes being smaller than the area of inflow opening 6 through which flow passes such that the throughflowing air encounters an increased flow resistance. This is realized in that cloths 11, 12 are not connected to each other at the position of this rear edge 23.

In the embodiment according to figure 3 the top and bottom strip 15 are provided with outflow openings 24.

Alternatively, cloths 11, 12 can be to some extent air-permeable, for instance somewhat porous. This embodiment is shown in figure 5. The structure is completely closed. In this embodiment the two cloths 11, 12 have mutually differing lengths. Because cloth 11 is shorter than cloth 12, a certain lifting force will occur in the manner of for instance an aircraft wing in the direction of the cloth 12 with the greater length. As already described above, flag 2 can hereby have a gentle flapping pattern, which has the effect of drawing attention.

In the embodiments according to figures 1, 2, 3 and 5, strips 15 are all congruent and are connected to cloths 11, 12 for instance by sewing or stitching. In the embodiment of figure 5 the strips are to some extent air-permeable. Alternatively, strips 15 can also be provided with perforations 25. This is shown in figure 3.

Figure 4 shows on enlarged scale a cross-section of the manner in which front edge 13 of a cloth 11 can be connected to a tube, rod or slat 9. The figure shows that the rear edge is wrapped for this purpose around element 9 and connected to itself by means of a stitched seam 27. Figure 6 shows the embodiment according to figure 3, in which the frame consists solely of two slats 9, 10. Due to the internal pressure occurring in flag 2 during operation in wind, cloths 11, 12 will tend to move apart, whereby strips 15 are placed under tensile stress and thus act as spacers. In the embodiment of figure 7 the slats 9 are curved and are mutually connected at their ends. As in all the drawn exemplary embodiments, the slats lie in one shared main plane. This is technically not essential.

In the embodiment according to figure 8 the structure according to figure 7 is supplemented with a stiffening and strengthening transverse element 18. This element is placed substantially under tensile stress and does not therefore necessarily have to be stiff. A cord or the like can also suffice.

Figure 9 shows an alternative in which the frame has a general triangular form.

Figure 11 shows an embodiment in which slats 9, 10 according to figure 6 are mutually connected, perhaps unnecessarily, by means of flexible cords 20, 21, 22. As the slats move apart under wind pressure, cords 20, 21, 22 will be tensioned.

Figures 1 and 12 show the manner in which frame 8 can co-act with flagpole 5 for up and downward movement (arrows 28) and for rotation (arrows 29). Coupled to transverse slats 18, 19 in this embodiment are two open, flexible rings 4, 3 of nylon which engage around pole 5. By means of a raising cord 30, which is guided downward through the hollow flagpole via a reversing roller present in the top of flagpole 5 by means of means which are not drawn but are generally known, the end of the raising cord can be coupled to a fixing device (not drawn) . Owing to the structure shown particularly clearly in figure 12, flag 2 will always orient itself to the wind in the manner of a weather-vane or a wind-sock due to the relatively high effective wind load on this flag 2, while the whole structure is already tensioned at a low wind-force.

Attention is drawn to the fact that the chambers bounded by cloths 11, 12 and the respective strips are preferably in pressure-equalizing mutual contact. As discussed, the material of the strips can display a certain permeability (figure 5) or be provided with passage openings 25 (figure 3) . In the embodiment of figure 2 an equalization of pressure will generally be unnecessary since the chambers all debouch in outflow opening 24.

It will be apparent that many variations and combinations of aspects are possible within the scope of the invention.

Claims

1. Flag structure (1), comprising: a flag (2) ; and coupling means (3, 4) carrying the flag for the purpose of coupling the flag structure (1) to a support structure, in particular a substantially vertical flagpole (5); characterized in that the flag (2) comprises: a frame (8) defining an inflow opening (6) for the wind (7), comprising at least two elongate elements (9, 10) such as slats which, at least during use in wind, extend at least more or less vertically at a mutual distance; two cloths (11, 12), the front edges (13, 14) of which are connected to the elongate elements (9, 10) and the remaining edges of which are at least partially connected to each other/ a group of strips (15) which extend over the full height of the flag (2) and which are each connected to the cloths (11, 12) with their two longitudinal edges (16, 17); and passage means for allowing passage with a certain flow resistance of air flowing via the inflow opening (6) into the space bounded by the cloths (11, 12) during operation in wind; which elongate elements (9, 10) are stiff relative to the cloths (11, 12) ; and that the coupling means (3, 4) are connected to the frame (8) ; this such that the flag (2) is tensioned by inflation during operation in wind, and orients itself to the wind in the manner of a weather-vane or a wind- sock.

2. Flag structure (1) as claimed in claim 1, wherein the frame (8) comprises at least one further elongate element (18, 19; 20, 21, 22) extending at least more or less in transverse direction relative to said two elongate elements (9, 10) .

3. Flag structure (1) as claimed in claim 1, comprising at least one outflow opening (24) present in the area of the rear edge (23) of the flag.

4. Flag structure (1) as claimed in claim 1, wherein the cloths (11, 12) are to some extent air- permeable.

5. Flag structure (1) as claimed in claim 4, wherein the cloths (11, 12) are fabrics comprising intersecting threads, the intersections of which are fixed, for instance by a calendering treatment.

6. Flag structure (1) as claimed in claim 1, wherein the cloths (11, 12) consist of parachute fabric.

7. Flag structure (1) as claimed in claim 1, wherein the two cloths (11, 12) have mutually differing lengths.

8. Flag structure (1) as claimed in claim 1, wherein the strips (15) consist of a flexible material.

9. Flag structure (1) as claimed in claim 8, wherein the strips (15) consist of cloth material.

10. Flag structure (1) as claimed in claim 1, wherein the strips (15) are to some extent air- permeable.

11. Flag structure (1) as claimed in claim 1, wherein at least one of the cloths (11, 12) carries information, for instance an advertising presentation.

12. Flag structure (1) as claimed in claim 1, wherein the coupling means have two coupling elements (3, 4), each having a general annular form.

13. Flag structure (1) as claimed in claim 12, wherein a coupling element (3; 4) comprises two curved jaws which are movable relative to each other between an open position, in which the coupling element can be positioned over the support structure, and a closed position in which the coupling element is coupled to the support structure with a certain mobility relative thereto.