COLLAPSIBLE SECURITY GRILL, GRILLE SYSTEM, BAR, AND METHOD

Abstract

The invention relates to a collapsible security grille. The grille comprises a multiplicity of successive bars that can be substantially stacked in a retracted state of the grille and can be substantially spaced apart with respect to each other in an extended state of the grille. At least a number of the bars comprises one or multiple parts formed from bent sheet metal. Advantageously, each of at least a number of the bars can be put together from at least a first part formed from a first blank of sheet metal and a second part formed from a second blank of sheet metal. In particular, at least the first part can be a bent profile. Additionally or alternatively, at least the second part can be a bent profile.

Claims

1. A collapsible security grille, comprising a multiplicity of successive bars that can be substantially stacked in a retracted state of the grille and can be substantially spaced apart with respect to each other in an extended state of the grille, wherein at least a number of the bars comprises one or multiple parts formed from bent sheet metal.

2. The grille according to claim 1, wherein each of the at least a number of the bars is put together from at least a first part formed from a first blank of sheet metal and a second part formed from a second blank of sheet metal.

3. The grille according to claim 2, wherein at least the first part is a bent profile, and/or wherein at least the second part is a bent profile.

4. The grille according to claim 2, wherein the first part is at least partly enclosing the second part, and/or wherein the first part defines a hollow room for accommodating the second part at least partly in an assembled state of the bar.

5. The grille according to claim 4, wherein the first part comprises one or multiple supports or retaining elements for supporting the second part and/or for facilitating retaining the second part at least partly within the first part.

6. The grille according to claim 1, wherein each of the at least a number of the bars is formed as a substantially hollow bar.

7. The grille according to claim 1, further comprising a multiplicity of elongated connecting elements for interconnecting respective bars.

8. The grille according to claim 6, wherein each of the substantially hollow bars has a first wall section facing towards an adjacent bar preceding said substantially hollow bar and a second wall section facing towards a subsequent bar succeeding said substantially hollow bar, the first wall section being provided with a number of first holes, the second wall section being provided with a number of corresponding second holes, wherein respective ones of the second holes form pairs with a respective one of the first holes, and wherein the pair of holes allows a respective one of the connecting elements to extend there through.

9. The grille according to claim 8, wherein each of the substantially hollow bars further has at least two sections defining side walls, each of said two side wall defining sections extending from the first wall section towards the second wall section or vice versa.

10. The grille according to claim 9, wherein at least one of the side wall sections comprise multiple layers of sheet metal, and wherein at least one of said side wall sections are put together from at least a first side wall section layer formed by the first part and at least a second side wall section layer formed by the second part.

11. The grille according to claim 8, wherein the first wall section is formed by a portion of the first part formed from a first blank of sheet metal, and/or wherein the second wall section is formed by a portion of the second part formed from a second blank of sheet metal.

12. A grille system, comprising the grille according to claim 1.

13. A bar for a collapsible security grille, comprising one or multiple parts formed from bent sheet metal, said bar composed from at least a first part formed from a first blank of sheet metal and a second part formed from a second blank of sheet metal, and wherein the first part and/or second part has a bent profile.

14. The bar according to claim 13, wherein the first part is at least partly enclosing the second part, and/or wherein the first part defines a hollow room for accommodating the second part at least partly in an assembled state of the bar.

15. A method for producing a bar for a collapsible security grille and/or for producing a collapsible security grille, comprising the steps of: providing a first bar part from sheet metal; providing a second bar part from sheet metal; and assembling a bar from at least said first bar part and said second bar part by sliding he second bar part at least partly into the first bar part in the longitudinal direction of the first bar part.

Description

[0021] By way of non-limiting examples only, embodiments of the present disclosure will now be described with reference to the accompanying figures in which:

[0022] FIG. 1A shows a schematic view of an embodiment of a collapsible security grille system having a grille situated in its extended state;

[0023] FIG. 1B shows a schematic view of the security grille system of FIG. 1A having its grille in its collapsed state;

[0024] FIG. 2A shows a schematic partly cut-away front view of a portion of an embodiment of a security grille according to an aspect of the present disclosure in its extended state;

[0025] FIG. 2B shows a schematic partly cut-away front view of the portion of the grille of FIG. 2A in its retracted state;

[0026] FIG. 3A shows a schematic perspective view of an embodiment of a bar for a security grille according to an aspect of the disclosure;

[0027] FIG. 3B shows a schematic perspective view of two bar parts of the bar of FIG. 3A; and

[0028] FIG. 4 shows a schematic partly cut-away cross-sectional top view a further embodiment of a collapsible security grille system.

[0029] The embodiments disclosed herein are shown as examples only and should by no means be understood as limiting the scope of the invention or the disclosure in any way. In this description the same or similar elements have the same or similar reference signs.

[0030] FIGS. 1A and 1B show a first embodiment of a collapsible security grille system 1 having a collapsible security grille 2 situated in its extended state 2A and its collapsed or so-called retracted state 2B, respectively. It is noted that the collapsible security grille 2 can be a stackable security grille. The stackable and/or collapsible security grille 2 may be suitable for securing a passage 3 at least partly, and can be arranged to be brought from an extended state 2A, in which the grille 2 can block the passage 3 at least partly, into a retracted state 2B, in which at least a part of the previously blocked part of the passage 3 is unblocked.

[0031] Although the passage 3, which can be formed as a door opening, in the embodiment shown in FIGS. 1A and 1B has a width which is smaller than its height, the collapsible security grille 2 and/or a security grille system 1 having the collapsible security grille 2 may in alternative embodiments have a relatively large width, preferably a width being larger than the height of the grille in extended state 2A.

[0032] As can be seen in FIGS. 1A and 1B, as well as in FIGS. 2A and 2B which show schematic views of a portion of a second embodiment of the security grille 2 in its extended state 2A and its retracted state 2B, the collapsible security grille 2 comprises a multiplicity of successive bars 4. As can be seen in FIGS. 1B and 2B, the bars 4 can be substantially stacked in a retracted state of the grille 2. Although the grille 2 can be retracted upwardly, as in the shown embodiments, the grille 2 may be retractable downwardly in other embodiments. For example, the stack of stacked bars 4 may then be accommodated within a cavity in the ground or floor, which cavity can then thus be located below the passage 3. As can be seen in FIGS. 1A and 2A, the bars 4 can be substantially spaced apart with respect to each other in the extended state 2A of the grille 2.

[0033] It is noted that the bars 4 can preferably extend substantially parallel to each other and/or that the bars 4 may preferably be substantially horizontally extending beams 4. However, in alternative embodiments, the bars 4 may extend in a different direction. For example, the bars 4 can extend substantially vertically and the grille 2 may be retractable in a sideward direction.

[0034] In embodiments, the bars 4 can be connected by means of multiple elongated connecting elements 5 for interconnecting respective bars 4. Said connecting elements 5 can substantially be formed as and/or may comprise a pin or peg. Although said connecting elements 5 may extend substantially transverse to the longitudinal direction of the bars 4 and/or substantially vertically, said connection elements 5 may extend in a different direction in alternative embodiments. For example, the connecting elements 5 may in alternative embodiments extend substantially horizontally.

[0035] At least a number of the multiplicity of elongated connecting elements 5 may each be arranged for interconnecting two respective spaced apart bars in the extended state of the security grille 2 in such a manner that the respective connecting element 5 counteracts that a first one 4A and a second one 4B of said two spaced apart bars 4A, 4B can be moved apart substantially further with respect to each other.

[0036] Thereto, said respective connecting element 5, 5A can be attached to the first bar 4A. Advantageously, a distal end of the connecting element 5 can be attached to the bar 4. Said distal end may preferably be an upper end of the connecting element 5 in case of an upwardly extending connecting element 5. For example, the connecting element 5 may be riveted to the bar or a respective bar part 42, e.g. by means of a blind rivet. However, alternatively or additionally, the connecting element may be connected by other means, e.g. by means of bolting, screwing 11, welding, etc.

[0037] Additionally, said respective connecting element 5, 5A can be provided with retainer element 7, e.g. a thickening 7 or lateral protruding portion 7, for limiting the distance D1 over which the first and second bars 4A, 4B can be spaced apart in the extended state 2A of the security grille 2. Said retainer element 7, which may be considered a retainer head 7, can preferably be located at a distal end of the connecting element 5, more preferably, in case of upwardly extending connecting elements, its lower end.

[0038] Said second bar 4B can have a passage 6, 60B for allowing the second bar 4B to be moved along a part, e.g. a shaft 5, of the elongated connecting element 5, wherein said passage 60B is arranged to block the retainer element 7 from passing there through. For example, at one point, e.g. at or near an upper end or side 4B of the bar 4, 4B, the passage 6, 60B may be narrower or tighter than and at another point, e.g. at or near a lower end or side 4B of the bar 4, 4B. Preferably, as in the shown embodiment of FIGS. 2A and 2B, the passage 6, 60B may be smaller at a side 4B of the second bar 4B facing towards the first bar 4A than at the opposite, second side 4B of the second bar 4B, which second side 4B is facing away from the first bar 4A and is facing to a third bar 4C. As a result, when the grille 2 is being extended and the connecting element 5 is moving through said passage 6, 60B in the second bar 4B, the retainer element 7 of said connecting element 5, 5A can enter into the second bar 4B via a relative wide part 60B of said passage 60B and can subsequently be stopped by a relative small part 60B of said passage 60B which then can counteract that the first bar 4A and the second bar 4B can be moved further apart from each other.

[0039] In advantageous embodiments in which the respective passage 6, 60B in the second bar 4B is narrowing in a direction towards the first bar 4A, it can be facilitated that the respective retainer element 7 can be accommodated at least partly within the second bar 4B in the extended state 2A of the security grille 2. For example, the narrowing passage 6, 60B in the second bar 4B can be formed by a first through hole 60B provided in a first wall section 45A of said second bar 4B and second through hole 60B provided in a second wall section 45B of said bar 4B located opposite said first wall section 45A. Said first wall section 45A of the second bar 4B may then be facing the first bar 4A, while the second wall section 45B of the second bar 4B may be facing a third bar 4C located at the opposite side of the second bar 4B as the first bar 4A.

[0040] It is noted that the third bar 4C, and preferably one or more further subsequent bars 4D, 4E, are provided with corresponding passages 61C, 61D, 61E for allowing the connecting element 5, 5A and its retaining element 7 to enter said passages 61C, 61D, 61E and preferably to pass through said passage 61C, 61D, 61E in order to enter one or more following bars 4C, 4D, 4E. Hence, the connecting element 5, 5A can extend through multiple subsequent bars 4B, 4C, 4D, 4E in the so-called retracted, packed, stacked, compacted or collapsed state 2B of the grille 2, as can be seen in FIG. 2B. It will be appreciated that said corresponding passages 61C, 61D, 61E in the third and further bars 4C, 4D, 4E through which said retaining element 7 has to pass during the collapsing of the grille 2 has to be wide W1 enough to allow the retaining element 7 to pass and should thus be wider than smallest part 60B of the corresponding passage 60B in the second bar 4B which is arranged to block said retainer element 7 from passing there through.

[0041] In preferred embodiments, the collapsible and/or stackable security grille 2 can be part of a security grille system 1 arranged for stacking the bars 4 in the retracted state 2B and for subsequently bringing the bars 4, or at least a part of the bars 4, back to the extended state 2A of the grille 2.

[0042] As can be seen in FIGS. 1A and 1B, as well as in FIG. 4, which shows a schematic partly cut-away cross-sectional top view a further embodiment of a collapsible security grille system 1, the grille system 1 may for instance comprise at least one bar guide 8, e.g. a guiding profile 8, for guiding the bars 4 when moving from the retracted state 2B toward the extended state 2A or vice versa and/or for counteracting that the bars 4, or at least respective parts thereof, can be moved in a transverse direction substantially transverse to the direction D2 in which the bars 4 extend and substantially transverse to the direction D1 in which the bars 4 are substantially spaced apart in the extended state 2A. For example, at both lateral ends 2, 2 of the grille 2, a respective bar guide 8A, 8B may be provided for guiding end portions 4, 4 of the bars 4.

[0043] Additionally or alternatively, the grille system 1 may comprise an actuator, e.g. a motor, such as an electromotor, for driving the grille, e.g. from its retracted or stacked state 2B to its extended state 2A or vice versa.

[0044] The grille system 1 may comprise a moving member, preferably a lifting member, such as a cable or chain, for moving, e.g. lifting, at least a part of the bars 4.

[0045] In advantageous embodiments, such as for instance in the embodiment shown in FIG. 4, the security grille system 1 may further comprise a chain 70 connected to the grille 2, preferably a chain 70 being flexible in only one dimension and/or being roller chain 70, and at least one chain limiting member 71 for at least locally limiting movement of the chain, e.g. in a direction in which it is flexible, such as to counteract that one or more links of the chain can be substantially moved away from a regular route along which the links move when the grille 2 is moved from its extended state 2A to its retracted state 2B or vice versa. For example, the chain 70 may be attached to a bottom one 4Z of the bars 4, e.g. by means of a connector 72, such as a bolt or the like. Said bottom one 4Z of the bars may have a relatively large height compared to the other bars 4 in order to accommodate respective connecting elements 5 therein in the retracted state 2B of the grille 2. The chain limiting member 71 can preferably be formed by means of a limiting profile 71, which may for instance be located within and/or parallel with a respective bar guide 8 or bar guiding profile 8.

[0046] FIG. 3A shows a schematic perspective view of an embodiment of a bar 4 for a collapsible security grille 2 according to an aspect of the disclosure. Advantageously, the bar 4 may be a substantially hollow bar.

[0047] The substantially hollow bar 4, 4B can have a first wall section 45A which during use faces towards an adjacent bar 4A preceding said substantially hollow bar 4B and a second wall section 45D facing towards a subsequent bar 4C succeeding said substantially hollow bar 4B. The first wall section 45A can be provided with a number of first holes 62A, 63A, and the second wall section 45D can be provided with a number of corresponding second holes 62D, 63D. Respective ones 62D, 63D of the second holes can then form pairs 62B, 63B with a respective one 62A, 63A of the first holes. Such pair of holes 62B, 62D; 63B, 63D, for instance together with a certain portion of a hollow room 43 within the bar 4, may then thus form a passage 6 through the bar 4. Said pair of holes and/or said passage can allow a respective one of the connecting elements 5 to extend there through.

[0048] Additionally to the first wall section 45A and the second wall section 45D, the substantially hollow bar 4 can have at least two sections 45B, 45C defining side walls of the bar 4. Each of said two side wall defining sections 45B, 45C can extend from the first wall section 45A towards the second wall section 45D or vice versa. It is noted that the elongated connecting elements may extend at least partly between two side wall sections 45B, 45C of the substantially hollow bar 4.

[0049] Here, the bar 4 has a substantially rectangular cross-section. Said cross-section can have a width W4 being larger then the height H4 of the bar, e.g. a width W4 being between 1.5 and 2.5 times wider than said height H4, preferably about 2 times wider. A relatively wide width, e.g. between 20 and 60 mm, preferably between 25 and 40 mm, such as for instance about 30 mm, can allow for relatively wide passages 6, and therefore for relatively thick and strong connecting elements 5, whereas a relatively small height H4 can facilitate that the grille 2 has a relatively small height H2 when its bars 4 are stacked in the collapsed state 2B of the grille 2.

[0050] However, in alternative embodiments, the cross-section may be formed differently. For example, the bars may have a relatively large height and/or a different shape, e.g. having a substantially square, circular or elliptical shape. It is noted that, for instance in case of a round or elliptical shaped cross-section, the side wall or side wall sections 45B, 45C of the bar 4 may substantially smoothly blend into the first and/or second wall section 45A, 45D, which may form an upper and/or a bottom wall section.

[0051] As shown in the exemplary embodiment of FIG. 3A, the bar 4 can comprise two parts 41, 42, preferably formed from a blank of sheet metal and/or bent sheet metal, especially bent steel sheets or bent steel plates. Although, the bar 4, such as the exemplary embodiment shown in FIG. 3A, may thus comprise two parts 41, 42, preferably both formed from bent sheet metal, the bar 4 may in alternative embodiments comprise more than two parts, e.g. three, four or five parts, or may alternatively comprise a single part. At least one of said one or multiple parts 41, 42 is formed from bent sheet metal, and one or more other parts of the bar 4 may be formed differently, for instance may be formed as a non-bent metal sheet part.

[0052] Advantageously, the metal sheet, especially a steel sheet, can be a purchase part and/or can have a standard thickness. The thickness of the steel sheet of which one or multiple parts can be formed can for instance be about 1 mm, 1.2, 1.5 mm, 2 mm, 2.5 mm, 3 mm or 4 mm, preferably about 2 mm.

[0053] Additionally or alternatively, the metal sheet, especially steel sheet, may be pre-galvanized, pre-coated or pre-painted.

[0054] Advantageously, the metal sheet, especially steel sheet, may be provided with a zinc-aluminum-magnesium coating, such as for instance the Magnelis coating marketed by ArcelorMittal. The zinc-aluminum-magnesium coating can be an alloy comprising, and preferably substantially consisting of, zinc, aluminum and magnesium. For example, the alloy may comprise at least 1%, 1.5%, 2% or 2.5% magnesium, such as for instance about 3% magnesium, at least 1.5%, 2%, 2.5% or 3% aluminum, such as for instance about 3.5% aluminum, and/or at least 80%, 85%, 90% or 92% zinc, such as for instance about 93.5% zinc. For example, the zinc-aluminum-magnesium coating can be applied to the sheet by means of a continuous hot dip galvanizing process.

[0055] An advantage of the zinc-aluminum-magnesium coating, especially the Magnelis coating, can lie in its self-repairing properties. For example, holes cut, especially punched or clipped or via another shearing technique, in a pre-coated sheet will have cut edges that can be protected by such coating. The coating, especially the Magnelis coating, can protect exposed cut edges with a relatively thin zinc-based protective film with magnesium, which prevents corrosive reactions. As a result, it may be superfluous to treat, e.g. coat, the pre-coated sheet, in particular steel sheet, more in particular a steel sheet pre-coated with a zinc-aluminum-magnesium coating, especially a Magnelis coating, after holes have been cut, especially punched, in said pre-coated sheet.

[0056] Advantageously, each of at least a number of the bars 4 of a security grille 2 can be put together from at least a first part 41 formed from a first blank of sheet metal and a second part 42 formed from a second blank of sheet metal. At least one said bar parts 41, 42, and preferably both, may be bent profile. The first part 41 can be at least partly enclosing the second part 42, and/or the first bar part 41 may define a hollow room 43 for accommodating the second part 42 at least partly in an assembled state of the bar 4. Advantageously, the second part 42 can be locked within the first part 41 in such manner that the second part 42 is substantially prevented from tilting or rotation about its central or longitudinal axis, e.g. letting the bar have a substantially rectangular cross-section. This may counteract jamming of the grille 2 and/or may counteract that the second 42, which can form an inner part 42, can unintentionally come loose from the first part 41 by falling there out, e.g. through a slit between two opposite supports 44A, 44B that can be provided at lower edges of the first bar part 41.

[0057] In embodiments, a bar part, especially the first bar part 41, may comprise one or multiple supports 44 or retaining elements 44. Said one or more supports 44 or retaining elements 44 may be for supporting a further bar part, especially the second part 42. Additionally or alternatively, said one or more supports 44 or retaining elements 44 may be for facilitating retaining said further bar part 42 at least partly within the bar part 41 provided with said one or more retaining elements 44 or supports 44.

[0058] Said supports 44 may for instance extend from a respective side wall section layer 41B, 41C in a substantially inward direction. For example, a first support 44A extending from a first side wall section layer 41B in a substantially inward direction can extend substantially toward a second support 44B that is extending from a second side wall section layer 41B in a substantially inward direction. Preferably, one or more supports 44 can be formed by bending or folding over parts of a blank. The supports 44 may for instance be formed by edges 44 of a profile 41 forming the respective bar part 41, especially the first bar part 41. Although the supports 44 are shaped as edges or strips, the supports may be formed differently. For example, one or both side wall section forming portions 41B, 41C of the first part 41 may be provided with one or multiple fingers for supporting the second part 42.

[0059] As can be seen in FIG. 3B, the first bar part 41 can be bent such as to have a substantially C-shaped or U-shaped cross-section, especially formed as an inverted U having inwardly extending supports 44 at the ends of its legs 41B, 41C or strokes 41B, 41C. The second bar part 42, which then for instance can be formed such as to have a U-shaped cross section, can then be positioned at least partly into a hollow space 43 within the first part 41.

[0060] As can be seen in FIG. 3, at least one, and preferably both, of the side wall sections 45B, 45C of the bar 4 can comprise multiple layers 41B, 42B; 41C, 42C of sheet metal. Advantageously, one or both of said side wall sections 45B, 45C of the bar 4 can be put together from at least a first side wall section layer 41B; 41C formed by the first part 41 and at least a second side wall section layer 42B; 42C formed by the second part 42.

[0061] In embodiments, the first part 41 of the bar 4 can have a first wall section 41A being provided with a number of first holes 62A, 63A. Said first wall section 41A of the first part 41 may form at least a part of the first wall section 45A of the bar 4 or may alone form said first wall section 45A of the bar. The first part 41 can further have two side wall section layers 41B, 41C each forming a layer 41B, 41C of a respective side wall section 45B, 45C of the bar 4.

[0062] In embodiments, the first bar part 41 may thus comprise two interspaced side wall sections 41B, 41C, and said first wall section 41A can then form an intermediate wall section interconnecting said two side wall sections. Said side wall sections of the first part can form first side wall section layers of the substantially hollow bar.

[0063] Additionally or alternatively, the second part 42 of the bar 4 can comprise the second wall section 45D of the bar 4, or at least a layer 42D thereof. Further, the second part 42 may comprise two interspaced side wall sections 42B, 42C, and the second wall section layer 42D can then form an intermediate wall section 42D interconnecting said two side wall sections 42B, 42C. Said side wall sections 42B, 42C of the second part 42 can form second side wall section layers of the substantially hollow bar.

[0064] The side wall sections 41B, 41C of the first part 41 may cooperate with said side wall sections 42B, 42C of the second part 42 in order to form side wall sections 45B, 45C comprising multiple layers, i.e. at least two layers. Since the first part 41 may enclose the second part 42 at least partly, said first side wall sections 41B, 41C formed by the first part 41 may be located at outer sides of the second side wall sections 42B, 42C formed by the second part 42. As a result of the multiple layers 41B, 42B; 42B 42C, the side wall sections 45B, 45C of the bar 4 may be relatively thick, relatively stiff, and/or relatively strong.

[0065] It is noted that one or both of the first and second wall sections 45A, 45B of the bar 4 can be substantially formed by a single layer of sheet metal. In embodiments in which the bar 4 is composed from multiple bar parts 41, 42, especially multiple profiles 41, 42, the first bar part 41, especially formed as a first profile 41, may comprise the first wall section 45A. Additionally or alternatively, the second bar part 42, especially formed as a second profile 42, may comprise the second wall section 45D.

[0066] For example because upper and lower wall sections 45A, 45D of the bar may not need to be as stiff as side wall sections 45B, 45C of the bar 4, it can be an advantage that said upper and lower wall sections 45A, 45D can be relatively thin, e.g. being composed from relatively few layers, preferably comprising a single layer of sheet metal only. Hence, when a certain combined side wall section thickness, i.e. the combined thickness of the layers 41B, 42B; 41C, 42C of the respective side wall section 45B, 45C, is desired, material can be saved for the first and/or second wall sections 45A, 45D. In contrast to prior art bars from rectangular pipes, which have substantially equal wall thicknesses along their periphery, the bars made from bent sheet metal, e.g. composed from multiple bar parts, can have relatively strong, rigid and/or thick side walls or side wall sections, while having relatively thin and/or light top and/or bottom walls or wall sections. Economizing on material may not only save money due to limited use of material, but may also result in relatively light bars. Due to weight savings, an actuator for stacking and unstacking, i.e. extending, the grille 2 may be of a relatively light and/or cheap version.

[0067] Advantageously, the first part 41 and the second part 42 of the bar are not fixedly attached to each other, such that the second part 42 can be moved with respect to the first part 41 to some extent. For example, the second part 42 can be moved with respect to the first bar part 41 to at least a small extent in at least a direction substantially parallel with the longitudinal direction D2 of the bar 4. By not fixedly or completely rigidly attaching the first and second bar parts 41, 42 to each other, the bar 4 and/or the grille 2 can allow for some play, as a result of which can be counteracted that bars 4 may unintentionally get stuck, e.g. in or between bar guide 8A, 8B guiding the grille 2 when being extended or collapsed.

[0068] Alternatively, or additionally, in embodiments, the grille 2 or the grille system 1 can comprise one or multiple, especially two, elongated relatively rigid guiding elements 73, e.g. formed as a rod, rail, bar or tube, extending through multiple succeeding bars 4. As can be seen in FIG. 4, such elongated guiding elements 73 may preferably be located at or near a respective end portion 4, 4 of the bar 4. Preferably, the elongated guiding elements 73 may be located within a respective bar guide 8A, 8B, such that said elongated guiding elements 73, which do not retract during collapsing of the grille 2, will not block a part of the passage 3 when the grille 2 is in its collapsed state (see FIG. 1B).

[0069] Due to the one or multiple elongated guiding elements 73 extending through through holes through the bar parts 41, 42 of succeeding bars, 4 mutual movement of the bar parts 41, 42 of a bar 4, e.g. at least in their axial or longitudinal direction D2, can be limited or counteracted, which for instance can counteract jamming. An additional or alternative advantage of the guiding elements 73 may be that they can give extra firmness to the grille 2 or grille system 1. For example, in the extended state of the grille 2, the elongated guiding elements 73 can at least partly transmit forces exercised on one of the bars 4 to one multiple of the other bars. As a result, e.g. when one is tampering with one of the bars 4, the grille 2 may more or less act as a whole, for instance to counteract that one of the bars is levered or wrenched out of the respective bar guide 8A, 8B. For instance, a tampering force applied to a certain bar may be transferred to another bar and the multiple bars may transmit the initial tampering force over different regions of the bar guide(s), which may result in a relatively strong grille system 1.

[0070] Although the guiding elements 73 and the corresponding through holes in the bars 4 have a circular cross-section in the embodiment shown in FIG. 4, it will be appreciated that they may have alternative shapes, e.g. rectangular, oval, etc. in alternative embodiments.

[0071] It is noted that for the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0072] Further, it is noted that the invention is not restricted to the embodiments described herein. It will be understood that many variants are possible.

[0073] For example, a first bar part and a second bar part do not need to have similar lengths. For example, a relatively long first bar part can hold multiple relatively short second bar parts.

[0074] Such and other variants will be apparent for the person skilled in the art and are considered to lie within the scope of the invention as formulated in the following claims.