Amphibious vehicle mounted on caterpillar tracks

Abstract

Vehicle comprising a hull and motorised aquatic propulsion members and motorised land propulsion members, this vehicle being able to move between a navigation position and a land transport position in which it rests on sets of caterpillar tracks. Each set of caterpillar tracks (1) is equipped with an even number of rollers (7) so as to define a set of adjacent roller pairs (71, 72). The rollers (71, 72) of each pair are connected to the chassis (2) by suspension means comprising a set (12) of at least two superposed curved elastic leaves made of a fibre-reinforced thermosetting resin, namely an upper leaf (131) and a lower leaf (132), the set being fixed on the one hand to the axles (9) of the rollers (71, 72) at its respective ends and, on the other hand, to the chassis (2) in its central part, and the upper leaf (13i) and the lower leaf (132) of each of the sets of leaves (12) are joined together and covered with a layer of elastomer (14).

Claims

1. An amphibious vehicle having a hull with a longitudinal axis and at least one lateral cavity, one or more motor-driven aquatic propulsion units, and one or more motor-driven overland propulsion units, each overland propulsion unit including at least one rigid articulated chassis and at least one track layer assembly mounted on the at least one rigid articulated chassis, wherein the at least one rigid chassis (2) is adapted to move between a retracted position, in which it is housed in a lateral cavity in the hull, and a deployed position, in which the amphibious vehicle rests on the at least one track layer assembly; the at least one rigid articulated chassis including: two pairs of lateral actuating arms (3, 3′) and a long beam connecting the two pairs of lateral actuating arms, each lateral actuating arm having an upper extremity and a lower extremity, wherein the upper extremity of each lateral actuating arm is articulated around, the hull, and the lower extremity of each lateral actuating arm is articulated around the long beam, and the at least one track layer assembly (1) being equipped with a series of transversal rollers (7) located one behind the other, parallel to the longitudinal axis of the hull, and being each endowed with two wheels (10.sub.1, 10.sub.2) mounted on roller beatings (11) on a rotation shaft (9) that is perpendicular to the longitudinal axis of the hull, wherein the series of transversal rollers includes an even number of rollers, such as to form one or more sets of neighboring roller pairs: wherein the rollers (7.sub.1, 7.sub.2) of each pair are connected to the rigid articulated chassis (2) by means of a suspension unit that includes a leaf spring set (12) of at least two curved flexible leaf springs made of a heat-hardening resin that is reinforced with superimposed fibers, wherein each flexible leaf spring includes a central portion and two extremities, wherein the at least two curved flexible leaf springs include one upper leaf spring (13.sub.1) and one lower leaf spring (13.sub.2), wherein each of the two extremities of each flexible leaf spring is connected to a rotation shaft (9) and the central portion of each leaf spring is connected to the chassis (2), and wherein the upper leaf spring (13.sub.1) and the lower leaf spring (13.sub.2) of each leaf spring set (12) are connected and are covered with a layer of elastomer (14).

2. The amphibious vehicle in accordance with claim 1, wherein each leaf spring is defined by a radius of curvature, the radius of curvature of each lower leaf spring (13.sub.2) is smaller than the radius of curvature of each upper leaf spring (13.sub.1).

3. The amphibious vehicle in accordance with claim 1, wherein each upper leaf spring (13.sub.1) is includes an exterior face a central transversal protrusion (15.sub.1, 15.sub.2) on the exterior face, wherein the central transversal protrusion has a triangular cross-section.

4. The amphibious vehicle in accordance with claim 3, wherein each leaf spring set (12) is secured to the chassis (2) by means of bolts, via a securing yoke (17) that is essentially U-shaped, wherein the securing yoke (17) includes a transversal cavity (22) that accomodates the central transversal protrusion (15.sub.1, 15.sub.2) of the leaf spring sets (12).

5. The amphibious vehicle in accordance with claim 1, wherein each leaf spring set (12) is secured to the chassis (2) by means of bolts, via a securing yoke (17) that is essentially U-shaped.

6. The amphibious vehicle in accordance with claim 5, wherein the securing yoke (17) interoperates with a tightening flange (19), such that the leaf spring sets (12 ) are sandwiched and held between the said tightening flange (19) and the securing yoke (17).

7. The amphibious vehicle in accordance with claim 1, wherein the lower leaf spring (13.sub.2) of each leaf spring set (12) is longer and less stiff than the upper leaf spring (13.sub.1) of each leaf spring set.

8. The amphibious vehicle in accordance with claim 7, wherein the lower leaf spring of each leaf spring set includes a counter-plate at each extremity that is secured to the rotation shaft by using bolts.

Description

(1) The characteristics of the amphibious vehicle addressed by the invention will be described in greater detail, with reference to the appended non-limitative drawings, in which:

(2) FIG. 1 is an in-perspective schematic view of a track layer assembly, in which the track has been removed;

(3) FIG. 2 is a front view of such a complete track layer assembly;

(4) FIG. 3 is a cross-section of a pair of rollers connected by a leaf spring set;

(5) FIGS. 4 and 5 are in-perspective views, at different angles, of the pair of rollers illustrated in FIG. 3;

(6) FIG. 6 is an in-perspective view of a leaf spring set;

(7) FIG. 7 is a cross-section of a roller.

(8) In FIGS. 1 and 2, the track layer assembly (1) is mounted on a rigid articulated chassis (2) incorporating two articulated arms (3, 3′) on either side of a long beam (4) connecting the said arms (3, 3′).

(9) The track layer assembly (1) incorporates a rotating caterpillar track (5) driven in rotation by a drive sprocket (6) and passing over a guide and tensioning roller, together with a series of transversal track rollers (7) located one behind the other in the direction of travel of the track layer assembly.

(10) In FIG. 2, a bezel (8) welded onto the long beam (4) conceals the transversal rollers (7).

(11) In FIG. 7, each of the transversal rollers (7) incorporates a rotation shaft (9) on which two wheels (10.sub.1, 10.sub.2) are mounted via roller bearings (11) each incorporating two rows of oblique-contact ballbearings, and which are respectively fitted into each of the wheels (10.sub.1, 10.sub.2).

(12) In FIG. 1, each track layer assembly (1) is equipped with eight track rollers divided into four pairs of neighboring rollers (7.sub.1, 7.sub.2).

(13) In FIGS. 3, 4 and 5, the rollers (7.sub.1, 7.sub.2) of each pair are connected to the chassis (2) by means of suspension systems principally composed of a set of flexible leaf springs (12) secured to the shafts (9) of the rollers (7.sub.1, 7.sub.2) at its extremities, and to the chassis (2), at its central part, in a manner that is described in greater detail subsequently in this explanation.

(14) In FIG. 6, each flexible leaf spring set is composed of two curved flexible leaf springs made of an epoxy resin reinforced with superimposed glass fibers, namely one upper flexible leaf spring (13.sub.2) and one lower flexible leaf spring (13.sub.1).

(15) These two flexible leaf springs—the upper leaf spring (13.sub.1) and the lower leaf spring (13.sub.2)—are connected together and are covered with a layer of polyurethane (14).

(16) In FIG. 6, in each of the flexible leaf spring sets (12), the lower leaf spring (13.sub.2) is longer and less stiff than the upper leaf spring (13.sub.1), and has a radius of curvature that is less than the radius of curvature of the upper leaf spring (13.sub.1), such that the thickness of the polyurethane layer inserted between these leaf springs (13.sub.1, 13.sub.2) is greater at the extremities of the flexible leaf spring set than at its central part.

(17) At this central part, the upper leaf spring (13.sub.1) and the lower leaf spring (13.sub.2) have a transversal protrusion (15.sub.1, 15.sub.2) on their respective exterior faces, that has a trianguar cross-section that prevents any longitudinal displacement of the flexible leaf spring set (12) in relation to the chassis (2).

(18) In FIGS. 4 and 6, the lower leaf spring (13.sub.2) is equipped at each of its extremities with a counter-plate (16) that secures the flexible leaf spring set (12) onto the shafts (9) of the rollers (7.sub.1, 7.sub.2) of a roller pair (7), at its respective extremities, by means of bolts that are not illustrated in the drawings.

(19) In FIGS. 1, 3, 4 and 5, the flexible leaf spring set (12) connecting the rollers (7.sub.1, 7.sub.2) of a roller pair is connected to the chassis (2), at the middle part, by means of an essentially U-shaped yoke (17) of which the middle branch (18) bears against the upper face of the flexible leaf spring set (12), such as can be observed in FIGS. 3, 4 and 5.

(20) In FIGS. 4 and 5, the securing yoke (17) interoperates with a tightening flange (19) bearing against the lower face of the flexible leaf spring set (12), such that it is sandwiched between the said tightening flange (19) and the securing yoke (18), at its central part.

(21) The assembly thus formed is secured either side of the flexible leaf spring set (12) by bolts (20) fitted right through the said assembly, and by nuts (21).

(22) In FIG. 3, the securing yoke (17) and the tightening flange (19) incorporate a transversal cavity (22, 23) with a geometry matching that of the transversal protrusions (15.sub.1, 15.sub.2) of the flexible leaf spring set, so as to be able to accommodate these transversal protrusions, in order to prevent any longitudinal displacement of the flexible leaf spring set (12) in relation to the chassis (2).

NOMENCLATURE

(23) 1. Caterpillar track layer assembly 2. Rigid chassis 3, 3′. Articulated arm 4. Long beam 5. Rotary caterpillar track 6.sub.1. Drive sprocket 6.sub.2. Guide and tensioning roller 7. Transversal rollers 7.sub.1, 7.sub.2. Roller pair 8. Bezel 9. Rotation shaft 10.sub.1, 10.sub.2. Wheel 11. Roller bearing 12. Flexible leaf spring set 13.sub.1. Upper flexible leaf spring 13.sub.2. Lower flexible leaf spring 14. Polyurethane layer 15.sub.1, 15.sub.2 Transversal protrusions 16. Counter-plate 17. Yoke 18. Middle branch 19. Tightening flange 20. Bolt 21. Nut 22, 23. Transversal cavities