WO2011111045A2

WO2011111045A2 - Chair for a vehicle

Info

Publication number: WO2011111045A2
Application number: PCT/IL2011/000229
Authority: WO
Inventors: Yiftah Karni; Patricia Rozana Sonia Grumberg
Original assignee: Paltechnica Nitzanim A.C.S. Ltd.
Priority date: 2010-03-10
Filing date: 2011-03-10
Publication date: 2011-09-15
Also published as: WO2011111045A3

Abstract

A chair for an armored vehicle is provided. The chair comprises one or more generally vertically extending rigid guides, a seat moveably affixed thereto and configured by substantially projecting perpendicularly therefrom, and one or more load-bearing arrangements. Each of the load-bearing arrangements comprises first and second elements configured to move in tandem with the seat along the rigid guide. The first element is characterized by a modulus of elasticity which is greater than that of the second element and is co-disposed therewith such that upon deformation of the first element within its elastic limit, the second element contacts the guide without breaking to transfer the load to the rigid guide for bearing at least a portion thereof.

Description

CHAIR FOR A VEHICLE

FIELD OF THE INVENTION

This presently disclosed subject matter relates to chairs for vehicles, and more particularly to chairs for vehicles which are shiftable between different positions.

BACKGROUND OF THE INVENTION

Armored combat vehicles are known to be equipped with a weapon mounted on an external portion thereof, such as a gun mounted on a roof of a vehicle. To access such gun for operation thereof, a gunner usually extends a portion of his body through an opening in the roof of the vehicle. Typically, the gunner retains within the vehicle as much of his body as possible in order to minimize his exposure to enemy fire. In order for the gunner to reach the roof and extend through the opening thereof, the vehicle is often equipped with a platform, upon which the gunner may stand.

SUMMARY OF THE INVENTION

According to one aspect of the presently disclosed subject matter, there is provided a chair for an armored vehicle, the chair comprising one or more generally vertically extending rigid guides, a seat moveably affixed thereto and configured by substantially projecting perpendicularly therefrom, and one or more load-bearing arrangements, each of the load-bearing arrangements comprising first and second elements configured to move in tandem with the seat along the rigid guide, the first element being characterized by a modulus of elasticity which is greater than that of the second element (i.e., the second element resists deformation more than the first element does) and being co-disposed therewith such that upon deformation of the first element within its elastic limit, the second element contacts the guide without breaking to transfer the load to the rigid guide for bearing at least a portion thereof.

Each of the guides may comprise two parallelly disposed rails giving rise to a channel therebetween, the first element being an internal wheel configured to rotate within the channel.

The internal wheel may have a diameter smaller, e.g., slightly smaller, than the distance between the rails. The internal wheel may be made of a rigid material, the material having a higher rate of elastic deformation than that of the rails. For example, the internal wheel may be made of plastic (with the rail being made of, e.g., metal).

Each of the load-bearing arrangements may comprise an external wheel bearing against an external side of one of the rails.

The external wheel may be configured to maintain the seat along a smooth path parallel to that of the guide.

The width of the second element may be less than that of the first element.

The second element may be a load-bearing block.

The second element of each load-bearing arrangement may be formed above the first element of the same load-bearing arrangement.

According to another aspect of the presently disclosed subject matter, there is provided a chair for an armored vehicle, the chair comprising:

• a seat configured to be shifted between a seat position and an inverted platform position; and

• an activation mechanism being configured for facilitating the shifting, and for facilitating moving the seat between a lowered position associated with the seat position, and a raised position associated with the platform position.

The chair may further comprise an upright post along which the seat is configured to move between its lowered and raised position, the activation mechanism comprising an arresting mechanism configured to move in tandem with the seat and to selectively arrest the movement of the seat at one of a plurality of positions along the upright post.

The upright post may comprise a plurality of apertures corresponding to the plurality of position, the arresting mechanism comprising a plug configured to selectively engage any one of the apertures.

The arresting mechanism may comprise a handle configured to disengage the plug from the apertures when engaged with one of them. A downward articulation of the handle may cause the disengagement. Thus, the seat may be quickly brought from its raised position to its lowered position by activating said handle (i.e., lowering it).

The seat may be rotatably articulated on each side to a support, and selectively held in place by two locking arrangements, one disposed on each side of the seat.

The chair may further comprise a mechanism configured to simultaneously disengage both of the locking arrangements. The mechanism may comprise a handle operatively connected to a transmission rod, wherein rotation of the transmission rod disengages both of the locking arrangements. The mechanism may further comprise a cam and follower arrangement operatively arranged between the transmission rod and each of the locking arrangements. The mechanism may further comprise biasing means configured to return the transmission rod to an original position thereof.

The locking arrangement may be a locking pin configured to engage with an aperture formed within a side of the seat.

The activation mechanism may be configured for facilitating the shifting while the seat is in its raised position.

According to a further aspect of the presently disclosed subject matter, there is provided a chair for an armored vehicle, the chair comprising:

• a seat being configured to be shifted between a seat position and an inverted platform position; and

• an activation mechanism configured to raise and lower the seat between a lowered position and a raised position;

wherein the mechanism is configured to bring the seat from the raised position to the lowered position while the seat bears the weight of a user thereupon.

According to a still further aspect of the presently disclosed subject matter, there is provided a chair for an armored vehicle, the chair comprising a seat, a backrest, and an elevator mechanism configured to raise and lower the seat with respect to the backrest, the elevator mechanism extending, and configured to move the seat, along substantially the entire height of the backrest and arrest it at a plurality of positions therealong. BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the presently disclosed subject matter and to see how it may be carried out in practice, an embodiment will now be described, by way of a non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1A is a perspective view of a chair according to the presently disclosed subject matter in a seat position;

Fig. IB is a perspective view of the chair illustrated in Fig. 1 A in a position between the seat position and a platform position;

Fig. 1C is a perspective view of the chair illustrated in Fig. 1 A in a platform position; Figs. 2 A and 2B are front and back perspective views, respectively, of an activation mechanism of the chair illustrated in Fig. 1 A;

Fig. 3 is a cut-away rear perspective view of an arresting mechanism of the activation mechanism illustrated in Figs. 2A and 2B;

Fig. 4A is a front perspective view of a casing of the activation mechanism illustrated in Figs. 2A and 2B;

Fig. 4B is a cross-section, taken along line IV-IV, of the casing illustrated in Fig. 4A;

Figs. 5A and 5B are schematic illustrations of an interior wheel and load-bearing block of the casing illustrated in Fig. 4A within a channel of the activation mechanism illustrated in Figs. 2A and 2B, at different operative positions thereof; and

Fig. 6 is a perspective view of a mechanism for disengaging seat-locking pins of the activation mechanism illustrated in Figs. 2 A and 2B.

DETAILED DESCRIPTION OF EMBODIMENTS

As illustrated in Fig. 1A, there is provided a chair, generally indicated at 10, for an armored vehicle. The chair 10 comprises a horizontal dual-purpose seat 12 and a generally vertical, slightly angled, backrest 14. In addition, the chair comprises an activation mechanism, which is generally indicated at 16, and which is designed to shift the seat 12 between a seat position, in which it is configured to be used for sitting thereupon, and an inverted platform position, in which it is configured to be used for standing thereupon (for example as a gunner's platform), as well as between a lowered position (generally associated with the seat position of the seat 12) and a raised position (generally associated with the platform position of the seat). In addition, the activation mechanism 16 may be configured to arrest the position of the seat 12 at a position between its raised and lowered position. The chair 10 may be fixed to the vehicle in any suitable manner, including, but not limited to, being bolted within the passenger cabin thereof, or being suspended within the passenger cabin by taut cables designed to absorb energy due to a blast.

The seat 12 comprises a top side 18, and a bottom side 20. The top side 18 is designed to be comfortable to a person sitting thereupon. Accordingly, it may be provided with a cushion 22, as illustrated in Fig. 1, of any appropriate design or material. Alternatively, it may be made of a rigid material, and molded so as to have an appropriate shape. The bottom side 20 is designed to be stood upon. Thus, it may be made of a rigid material and formed with a downwardly-facing (i.e., when the seat 12 is in its seat position; it will be appreciated that the bottom side 20 is upwardly-facing when the seat is in its platform position) generally flat surface. The flat surface may be knurled or otherwise provided with a non-slip or similar arrangement thereon.

As illustrated in Figs. 2A and 2B, the activation mechanism 16 comprises a seat-support portion, which is generally indicated at 24, and an elevator mechanism, which is generally indicated at 26. The seat-support portion 24 is configured for directly holding the seat 12 and selectively maintaining its position in one of its seat and platform positions. The elevator mechanism 26 is configured for selectively raising/lowering the seat-support portion 24 (and thus the seat 12) with respect to the backrest 14 (or with respect to a bottom-most portion of the chair 10), and for maintaining its position at a desired height.

The seat-support portion 24 comprises two generally chevron-shaped support brackets 28, one on either side of and together carrying the seat 12 (not illustrated in Figs. 2A and 2B). It will be appreciated that the support brackets 28 may be formed having any appropriate shape, and are not limited to being generally chevron-shaped.

The support brackets 28 each comprise a generally horizontally extending arm 30 for supporting the seat 12, facilitating shifting the seat between its two positions, and selectively maintaining it in either of the positions. As such, it comprises two apertures (not visible) horizontally arranged along the arm 30. A first aperture is provided with an axle 32 extending thereto into the side of the seat 12 at a point near the midpoint thereof, about which the seat is rotatably articulated, and about which it may rotate between its two positions. (It will be appreciated that the axle 32 may be formed integrally with the arm 30 projecting toward the seat, and not as a separate element therefrom.) A seat-locking pin 34, constituting a locking arrangement, extends through the second aperture into the side of the seat at a point spaced from that which receives the axle 32. It will be appreciated that the seat 12 comprises corresponding apertures formed in its side to receive the axle 32 and seat-locking pin 34 (one of the corresponding apertures is seen in Fig. 1 A and designated 36). A cover 35 may be provided over the seat-locking pin 34, which is useful for a user to grip in order to facilitate raising the seat 12. In addition, the seat-locking pin 34 may be connected thereto, with the cover 35 thus being useful as a grip to facilitate grasping of an element connected to the seat-locking pin in order to disengage it from its corresponding aperture 36.

A mechanism for disengaging both seat-locking pins 34 simultaneously may be provided. As illustrated in Fig. 6, the mechanism comprises a handle 94 operatively connected to a transmission rod 96. A helical spring 98, constituting a biasing arrangement, is provided, configured to rotate in tandem with the transmission rod 96, and bearing against a rigid portion of the chair 10. A cam 100 is provided coupled to the transmission rod 96 to rotate in tandem therewith and to engage a follower bar 102. The cam 100 comprises an angles slot 104 therein, in which a first end 102a of the follower bar 102 slides. A second end 102b of the follower bar 102 is connected to the seat-locking pin 34. A support element 106, which may be attached to the support bracket 28 (not illustrated) at one end thereof and pivotably articulated to the follower bar 102 at the other, is provided. The support element 106 ensures that the point at which the follower bar 102 is connected thereto is maintained at a fixed distance from the support bracket 28, facilitating pivoting of the follower bar about an axis X passing through the support element. A similar mechanism (without handle 94) is provided on the other side of the seat 12, with a single transmission rod 96 being common between them.

In operation, the seat-locking pin 34 is initially in a seat-locking position (i.e., engaged with corresponding aperture 36). The handle 94, and thus the cam 100, are rotated in a direction indicated by arrow A. This results in the first end 102a of the follower bar 102 being moved in a direction indicated by arrow B. The follower bar 102 thus pivots about axis X, resulting in the second end 102b, and thus the seat-locking pin 34, moving in a direction indicated by arrow C, thereby disengaging the seat-locking pin. The mechanism on the other side of the seat 12 operates in a similar manner to that described above substantially simultaneously. After the handle 94 is released, the helical spring 98 serves to bias the transmission rod 96 back toward its original position, resulting in re-engagement of the seat-locking pin 34.

A corresponding arrangement is provided on the other side of the seat, using the same transmission rod 96. Thus, the operation described above serves to disengage both seat-locking pins 34 simultaneously. In addition, the seat 10 may be raised/lowered by a user by gripping the handle 94 and pulling upwardly/downwardly. Thus, shifting of the seat between seat and platform positions, as well as between raised and lowered position, may be performed in a single operation by a user.

In order to rotate the seat 12 between its seat and platform positions, the seat-locking pins 34 are disengaged from apertures 36, the seat is rotated (as seen in Fig. IB), and, once the seat is in its platform position (as seen in Fig. IC), the seat-locking pins 34 are re-engaged with apertures 36 to lock the seat into position. In order to revert the seat 12 back to its seat position, the above operation is reversed. As further seen in Figs. 1 A and IC, typically the seat position of the seat 12 is associated with a lowered position thereof, and the platform position of the seat is typically associated with the raised position thereof, although this is not required. It will be appreciated that other mechanisms for rotation of the seat 12 may be provided without departing from the scope of the presently disclosed subject matter, mutatis mutandis.

The support brackets 28 each further comprises a generally vertically extending upright support portion 38, which is configured for supporting a casing 40 of the activation mechanism 16 in its proper position vis-a-vis the seat 12. As such, it comprises a series of apertures 42 for passage therethrough of bolts (not illustrated) or any other appropriate fastening means for securing the casing 40 thereto. In addition, the upright support portion 38 comprises a slot 44 for passage therethrough of an arresting handle 46, whose function and purpose will be described hereinbelow.

As noted above, the elevator mechanism 26 is configured for positioning the seat by selectively raising/lowering the seat-support portion 24 with respect to the backrest 14, and for maintaining its position at a desired height. As such, it comprises an upright post 48, which extends generally vertically and substantially parallel to the backrest 14 (and thus slightly angled), an arresting mechanism 50, and the casing 40 (not illustrated in Fig. 2B) carrying the seat-support portion 24 and several internal and external guidewheels 52, 54, which, together with portions of the casing, constitute a load-bearing mechanism.

As noted above, the elevator mechanism 26 is configured for positioning the seat by selectively raising/lowering the seat-support portion 24 with respect to the backrest 14, and for maintaining its position at a desired height. As such, it comprises an upright post 48, which extends generally vertically and substantially parallel to the backrest 14 (and is thus slightly angled), an arresting mechanism 50, and the casing 40 (not illustrated in Fig. 2B) carrying the seat-support portion 24 and several internal and external guidewheels 52, 54, which, together with portions of the casing, constitute a load-bearing arrangement. The upright post 48 extends generally vertically and substantially parallely to the backrest 14, and its major width is generally parallel thereto. On each side thereof is formed a channel 56, defined between two outwardly projecting and parallelly disposed rails 58a, 58b, which together constitute a rigid guide for the internal guidewheel 52, as will be described below. (Hereinafter, when the rails are referred to together, the generic designation 58 will be used to refer to both rails 58a, 58b collectively.) A plurality of apertures 60 are formed within the channel 56 at various heights therealong with optional cylinders 62 spanning between several of the apertures opposite one another. The channel 56 extends between upper and lower stoppers 64, 66.

The arresting mechanism 50 is configured to arrest the movement of the casing 40, and thus the seat-support portion 24, at a selected height of the upright post 48 and to maintain its position there with respect to the upright post 48. As such, and as illustrated in Fig. 3, it comprises a plug 74 within the casing 40, extending between an interior wall 76 and an exterior wall 78 thereof. A through-going aperture 80 is formed within the interior wall 76 positioned and sized so as to permit passage therethrough of the plug 74.

A first side 82 of the plug 74, adjacent the interior wall 76 of the casing 40, is of a diameter which may be received snugly within one of the cylinders 62 via one of said apertures 60 within the upright post 48, facilitating engagement of the plug within the cylinders; when so received, the position of the casing 40, and thus the seat-support portion 24, is maintained at a fixed height. As the upright post 48 is provided with a plurality of apertures 60 and cylinders 62, the arresting mechanism 50 may be configured to selectively arrest the movement of the casing 40, and thus of the seat 12, at any one of a plurality of positions along the height of the upright post.

A second side 84 of the plug 74, adjacent the exterior wall 78 of the casing 40 and opposite the first side, is of a diameter which is smaller than that of the first side. The interface between the two sides 82, 84 is abrupt, giving rise to a shelf 86 therebetween. A spring 88 is provided around the second side 84, abutting the shelf 84 on one side thereof and a stopper 90 fixed within the exterior wall 78 of the casing 40 on the other. The spring thus serves to bias the plug toward the interior wall 76.

The arresting mechanism 50 further comprises the arresting handle 46, which is attached to the plug 74 via a spindle 92 rotatably articulated to a side wall (not illustrated) of the casing 40. The slot 44 formed within the side of the casing 40 allows the handle 46 to be articulated downwardly, causing the plug 74 to be distanced from the interior wall 76, thus disengaging it from the cylinder 62, and allowing the casing 40, and thus the seat-support portion 24, to move along the upright post 48.

As seen in Figs. 4A and 4B, the casing 40 is formed with upper and lower openings 68 (only the upper opening being visible), with a hollow 70 therebetween. The openings 68 are formed so as to permit receiving therethrough the upright post 48, i.e., its shape is in accordance with the cross-section of the upright post. A load-bearing block 72 is formed with the casing 40 projecting from the interior thereof toward the opening 68. The load-bearing block 72 may be formed above the internal and external guidewheels 52, 54.

The internal and external guidewheels 52, 54 are articulated to the casing 40 such that their positions relative thereto are fixed, but with freedom of rotation thereof allowed.

It will be appreciated that as the casing 40 is rigidly attached to the seat-support portion 24 which carries the seat 12, all elements thereof and/or attached thereto may move in tandem with the seat.

Each of the internal guidewheels 52 is disposed in proximity to one of the load-bearing blocks 72, and is of a diameter D which is slightly smaller than the width of the channel 56 (i.e., this width is the distance between the rails 58) and slightly larger than the width (in a direction perpendicular to that in which the rails extend) of the load-bearing block adjacent thereto, as indicated by W. In addition, at least the internal guidewheel 52 may be made of a material which is generally rigid, but which undergoes a high degree of elastic deformation relative to that of the material of the casing 40, and specifically of the rails 58. For example, the casing 40 may be made of steel or aluminum, with the internal guidewheels 52 being made of a plastic material.

The external guidewheels 54 are disposed so as to bear against an outwardly-facing side of the rails 58, serving to maintain the position of the upright post 48 within the hollow 70, and thus maintaining the seat 12 along a smooth path parallel to that of the channel 56.

As noted above, interior guidewheels 52 and the load-bearing blocks 72, constitute portions of a load-bearing arrangement, utilizing the geometry of the channel 56. As illustrated schematically in Fig. 5A, when casing 40, and thus the seat-support portion 24, moves along the height of the upright post 48, the interior guidewheels 52 facilitate a smooth motion thereof. When a elevated load develops on the seat 12, for example when the vehicle is traveling over rough terrain, especially when a user is standing thereon in its platform position, each of the interior guidewheels 52 deforms slightly at 52a, as illustrated in Fig. 5B, causing its associated load-bearing block 72 to contact one of the rails 58 without breaking (i.e., without undergoing catastrophic and/or irreversible structural failure), thus transferring the increased load to the casing 40 directly. Thus, the load-bearing arrangement is useful for facilitating efficient and quick transferring of an increased load (which may occur in any direction) to an appropriate part of the elevator mechanism 26, thus maintaining stability of the seat 12 even under adverse conditions. It will be appreciated that the sizes of the interior guidewheels 52, the width of the channel 56, and of the load-bearing blocks 72 are co-selected such that the deformation of the interior guidewheel as described above is limited to the elastic range thereof, thus reducing or preventing any permanent damage thereto.

The use of the upright post 48 as an element of the elevator mechanism 26 along which the casing 40 moves, and thus which determines the path along which it is displaced, may have certain advantages. For example, the maximum allowable length of displacement of the seat 12 is limited only to the height of the backrest 14 (provided that, for design or aesthetic reasons, it is not desired that the upright post 48 extend higher than the backrest; if the designer is not thus constrained, the length of displacement may be even longer), which is typically more than a sufficient displacement.

Furthermore, when the seat 12 is in its platform and raised positions, it may be utilized, as noted, as a gunner's platform, in which the user stands upon the fiat surface of the bottom side 20 of the seat, with the upper part of his body projecting out of an opening formed in the roof of the vehicle. In the event that the user needs to escape quickly into the vehicle, for example if he comes under fire, lowering of the casing 40, and thus the seat-support portion 24, with the seat 12, may be accomplished extremely quickly by providing a quick-release mechanism to release any engaged arresting mechanism.

It will be appreciated that the seat 12 may be shifted between its seat and platform positions by alternative methods, i.e., besides rotation as described above. For example, the cushion 22 may be detachable therefrom, and secured thereto by an arrangement, e.g., a hook and pile arrangement such as that sold under the name Velcro®, which enables easy attachment/detachment of the cushion. Alternatively, the cushion 22 may be pivotably articulated to the chair 10, such that it may be flipped on and off the seat 12.

Those skilled in the art to which the presently disclosed subject matter pertains will readily appreciate that numerous changes, variations and modifications can be made without departing from the scope of the presently disclosed subject matter mutatis mutandis.

Claims

CLAIMS:

1. A chair for an armored vehicle, said chair comprising one or more generally vertically extending rigid guides, a seat moveably affixed thereto and configured by substantially projecting perpendicularly therefrom, and one or more load-bearing arrangements, each of said load-bearing arrangements comprising first and second elements configured to move in tandem with said seat along said rigid guide, the first element being characterized by a modulus of elasticity which is greater than that of the second element and being co-disposed therewith such that upon deformation of said first element within its elastic limit, said second element contacts said guide without breaking to transfer the load to said rigid guide for bearing at least a portion thereof.

2. The chair according to Claim 1, wherein said each of said guides comprises two parallelly disposed rails giving rise to a channel therebetween, said first element being an internal wheel configured to rotate within said channel.

3. The chair according to Claim 2, wherein the internal wheel has a diameter smaller than the distance between said rails.

4. The chair according to Claim 3, wherein the internal wheel has a diameter slightly smaller than the distance between said rails.

5. The chair according to any one of Claims 2 through 4, wherein said internal wheel is made of a rigid material, said material having a higher rate of elastic deformation than that of the rails.

6. The chair according to Claim 5, wherein said internal wheel is made of plastic.

7. The chair according to any one of Claims 2 through 6, wherein each of said load- bearing arrangements comprises an external wheel bearing against an external side of one of said rails.

8. The chair according to Claim 7, wherein said external wheel is configured to maintain the seat along a smooth path parallel to that of the guide.

9. The chair according to any one of the preceding claims, wherein the width of the second element is less than that of the first element.

10. The chair according to any one of the preceding claims, wherein said second element is a load-bearing block.

11. The chair according to any one of the preceding claims, wherein said second element of each load-bearing arrangement is formed above said first element of the same load-bearing arrangement.

12. A chair for an armored vehicle, said chair comprising:

• an activation mechanism configured for facilitating the shifting, and for facilitating moving the seat between a lowered position associated with the seat position, and a raised position associated with the platform position.

13. The chair according to Claim 12, further comprising an upright post along which the seat is configured to move between its lowered and raised position, said activation mechanism comprising an arresting mechanism configured to move in tandem with the seat and to selectively arrest the movement of the seat at one of a plurality of positions along said upright post.

14. The chair according to Claim 13, wherein said upright post comprises a plurality of apertures corresponding to said plurality of position, said arresting mechanism comprising a plug configured to selectively engage any one of said apertures.

15. The chair according to Claim 14, wherein said arresting mechanism comprises a handle configured to disengage said plug from said apertures when engaged with one of them.

16. The chair according to Claim 15, wherein a downward articulation of said handle causes the disengagement.

17. The chair according to any one of Claims 12 through 16, wherein said seat is rotatably articulated on each side to a support, and selectively held in place by two locking arrangements, one disposed on each side of said seat.

18. The chair according to Claim 17, further comprising a mechanism configured to simultaneously disengage both of said locking arrangements.

19. The chair according to Claim 18, wherein said mechanism comprises a handle operatively connected to a transmission rod, and wherein rotation of said transmission rod disengages both of said locking arrangements.

20. The chair according to Claim 19, wherein said mechanism further comprises a cam and follower arrangement operatively arranged between said transmission rod and each of said locking arrangements.

21. The chair according to any one of Claims 19 and 20, wherein said mechanism further comprises biasing means configured to return said transmission rod to an original position thereof.

22. The chair according to any one of Claims 17 through 21, wherein said locking arrangement is a locking pin configured to engage with an aperture formed within a side of said seat.

23. The chair according to any one of Claims 12 through 22, wherein said activation mechanism is configured for facilitating the shifting while said seat is in its raised position.

24. A chair for an armored vehicle, said chair comprising:

· a seat being configured to be shifted between a seat position and an inverted platform position; and

wherein said mechanism is configured to bring said seat from the raised position to the lowered position while said seat bears the weight of a user thereupon.

25. The chair according to Claim 24, further comprising an upright post along which the seat is configured to move between its lowered and raised position, said activation mechanism comprising an arresting mechanism configured to move in tandem with the seat and to selectively arrest the movement of the seat at one of a plurality of positions along said upright post.

26. The chair according to Claim 25, wherein said upright post comprises a plurality of apertures corresponding to said plurality of position, said arresting mechanism comprising a plug configured to selectively engage any one of said apertures.

27. The chair according to Claim 26, wherein said arresting mechanism comprises a handle configured to disengage said plug from said apertures when engaged with one of them.

28. The chair according to Claim 27, wherein a downward articulation of said handle causes the disengagement.

29. A chair for an armored vehicle, said chair comprising a seat, a backrest, and an elevator mechanism configured to raise and lower the seat with respect to the backrest, said elevator mechanism extending, and configured to move the seat, along substantially the entire height of the backrest and arrest it at a plurality of positions therealong.