FR2696705A1 - Pneumatic buoyancy structure for multi-hulled vessel - comprises three inflatable compartments of neoprene or PVC-coated fabric situated lengthwise in space between hulls - Google Patents

Abstract

The pneumatic structure consists of three separate compartments (6), separated by partitions (6) and made from a fabric coated with neoprene or PVC. The compartments are situated lengthwise in the space between the hulls of a catamaran or multi-hulled vessel and can be inflated or deflated to vary the vessel's draught. When in the deflated state, the compartments can be retracted against the underside of the vessel by means of rollers (3) attached to the ends of the compartments by lengths of fabric (8). ADVANTAGE - Enables vessel to be supported in the water in the event of loss of buoyancy.

Description

 Navigation devices have been known for a long time consisting of two or more floats connected together by a chassis or a floor and between which is possibly a means of propulsion.

 These devices have the drawback of losing all stability as soon as one of the floats is damaged or of very difficultly being bailed out in the event of grounding.

 The present invention therefore consists in placing under the platform connecting the hulls of a multihull type machine an inflatable structure intended to relieve machine of a variable height according to the volume of air introduced into the structure by a double pump action (swelling deflation by suction).

Figure 1 shows, in section, along AA the ship equipped with the pneumatic structure (1) pressed under the bridge (2) in deflated position
2 shows, front view, along F the ship equipped with the structure (1) in the deflated position.

 FIG. 3 represents the pneumatic structure in the lowered position after inflation, along the axis AA.

 Figure 4 shows it in the same position, a view along F.

 FIG. 5 shows in section the method of fixing the ends (8) of the inflatable volume consisting of a strip of fabric terminated by a rope being threaded in a slide made along a roller (3), thus allowing the winding of the band.

 FIG. 6 represents in section a rope (5) fixed all along the upper part of the inflatable volume and coming to be threaded in a slide secured to the bridge (2) in its lower part.

 The structure is produced by assembling widths of fabric coated by gluing or welding. It consists of three independent compartments (6) mounted on an angle iron and separated by partitions (5).

 On their upper part, each compartment is equipped with a suction and discharge pump (4) fixed on the deck.

 The structure is lined in its lower part by a strip of very resistant fabric (8) which is extended at both ends to come and reel around an axis (3).

 Throughout its upper face, on the outside, the structure is equipped with slings (5) intended to hold it under the bridge (2) for insertion into the guides fixed to the bridge (6).

 FIG. 7 represents the inflatable structure alone, protected in its lower part by a strip of very resistant coated fabric (8), the ends of which are equipped with slings come to roll on axes (3) in order to tension the whole for maximum plating under the hull .

 The three compartments (6) are isolated by partitions (5) and equipped at their upper parts with pumps (4) with double effect (swelling, deflation).

 This set works in 2 positions; inflated or deflated.

 In the inflated position fig. 3 and 4, the pneumatic volume (l) is maintained on either side by the interior face of the hulls of the boat, retained at the top by the deck, downwards by longitudinal internal spacers (5) forming watertight compartments (6).

 As the pumps (4) inflate the structure (1) deploys beyond the natural waterline (7), thus relieving the boat of the volume of water by a proportion equal to the volume of air supplied, the draft is then reduced by as much (7a).

 The machine can then navigate in an extremely reduced water level.

 The deflated position fig 1 and 2 stobtientsimultaneously by suction of the pumps (4) for evacuating the inflatable volume (1) and winding the ends equipped with a luff (Fig 5) around two rollers (3) fixed to each edge of the tray.

 This winding can be completed by cables or straps stretched between the two ends of the bridge by winches or any other system.

The structure is then entirely flattened under the deck (2) without any discomfort for rapid navigation in the natural water lines of the boat, whatever the speed.

Due to the variation in the trim of the boat, determined by the volume of air supplied, the motors used (propellers or turbines) must be able to follow these variations
The structure can affect any shape or size corresponding to the characteristics of the machine. It can occupy all or part of the tunnel between the hulls.

 It can be fixed under the tunnel either by slings (Fig. 6) sliding in rails, or by any other system.

The invention and the advantages which it brings will be better understood thanks to the examples of embodiment given below by way of indication and without limitation: damage to perform
repairs.

- fairing without hulling obligation.

- moving in a lower water level - increasing the total weight under load.

- In certain cases, non immobilization of the Vessel
due to tidal fluctuations.

 The invention is not limited to the embodiment shown and described in detail, but it covers all the variants produced in the same spirit, in particular it extends to all multihulls, barges or floating pontoons.

 Likewise the manufacturing method, the usable materials (fabrics, neoprenes, pvc etc ...) and all the systems for fixing to the different shells.

 Its essential quality, object of the present invention is that it is inflatable, which ensures the advantages mentioned above.

Claims (5)

1 - Pneumatic structure executed by assembling widths of  fabric coated with neoprene or polyvinyl chloride,  mounted on angles of fabric more loaded with coating,  so as to form three independent compartments (Fig. 7)  characterized by the fact that its swelling or degon  also varies the draft of the propor multihull  the amount of air introduced fig. 2 (7) and  fig. 4 (7bis) 2 - Pneumatic structure according to claim 1 characterized  by the fact that it is kept under the intercoch (2) by  vacuum due to suction pumps (4) serving  also to inflate it, without hampering speed navigation  quick. 3 - Pneumatic structure according to claims 1 and 2  characterized by the fact that at the end of depression it  is firmly pressed by the tension given by winding  of its ends on rollers (3) located transversely  at the two ends of the intercoque. 4 - Pneumatic structure according to claims 1 2 and 3  characterized by the fact that at the end of deflation and at the end  of tension, its maintenance under the intercoque is consolidated by  one or more straps stretched by winches located at  two ends of the intercoch. 5 - pneumatic structure according to claim 1 characterized  by the fact that it is kept in the inflated position of  on both sides by the inside face of the floats,  retained at the top by the bridge and down by between  longitudinal longitudinal rods (5) forming comparisons  waterproof materials. 6 - Pneumatic structure according to claims 1 2 3 4  characterized by the fact that it is protected on its part  lower by a strip of rubberized canvas (8) which  extends at both ends to come and wrap on  trees (3) thus participating in the application of the structure  under the hull.