GB2248049A - Steering rudder for waterborne vessels has primary and secondary blades - Google Patents

Abstract

A steering rudder for a waterborne vessel has a main control blade 2 and a secondary control blade 3 hinged about the trailing edge of the main control blade to divert a greater portion of fluid flow laterally to the vessels longitudinal centre line. A round sectioned flow diverter and turbulence delimiter 1 is attached to the leading edge of the main control blade 3 and a plurality of horizontal flow directional stabiliser fins are mounted on the secondary control blade. A control linkage 11, 12, 13, mounted on the hull of the vessel, ensures correct angular relationship between the main and secondary blade surfaces. <IMAGE>

Description

CAPFLOW RUDDER This invention relates to a steering rudder applicable to any water borne vessel varying in size from a large ship to small powered boat.

Rudders are objects of well known marine equipment comprising of a flat or shaped compound curved planar surface, used in practice to change the direction of any water borne vessel under forward or backward motion by means of hydrodynamic imbalance and redirecting the vessels propulsion means or static relative flow. This invention directs a greater proportion of water flow and so thrust at a direction close to a maximum of 90 degrees, by utilising the inventions developed capflow principal, thus resulting in greater angular water flow from the vessels iognitudinal centreline and consequently providing increased directional maneouvrability.

In the present invention the rudder steering surface is divided into two separate planar surfaces (referred to in subsequent text as the Primary and Secondary blades being the forward and trailing sections of the rudder respectively) which are permitted and caused to hinge about the ajoinment of the two separate sections. The hinged sections and associated relative angular movement are independent of the normal rudder turning angle as is determined by the normal steering gear and thus transmitted to the primary blade, in that the angle of the secondary or trailing blade is so controlled as to be at all times double the angle of primary rudder blade angle as determined by the aforementioned normal steering gear.An example in that at a maximum rudder angle of 45 degrees to the left or right (port or stbd) of the longnitudinal centre line of the vessel would produce an angle of 90 degrees to the left or right (port or stbd) respectively in the case of the secondary blade to the vessels longnitudinal centre line. Substituted only as illustration of the operating principal and as optional primary values usable in, but not excluding values in the previous example, can be primary rudder blade angles of 20, 30, 40 degrees etc. yielding compounded secondary blade angles of 40, 60, 80 degrees etc while notably constantly maintaining the secondary rudder blade anglular doubling of any anglular position of the primary blade.The angular displacement between the two planar surfaces is controlled by a swivel mounted linkage which is fixed by means of suitable fabrications or fixings to the main body or hull of the vessel to which the rudder is fitted. This linkage ensures the fixed angular relationship between the primary and secondary blades as described in the previous example.

Attached vertically to the leading edge of the primary blade is a round sectioned longnitudinal flow diverter which is designed to smooth the flow of water and reduce tubulence as a rapid change of direction and fluid velocity is induced. Fins are horizontally attached to the secondary rudder blade at equally distant intervals in a vertical direction on both sides to maintain directional flow and decreased turbulence.

A specific embodiment of the invention will now be described by way of reference to the accompanying drawing in which: Fig 1.. Shows the side elevation of the rudder unit as seen from the port hand side of vessel.

Fig 2.. Shows the end elevation of the rudder unit as seen from the rear of the vessel.

Fig 3 & 4.. Both show diagramatic angular plan relationships between the primary and secondary rudder blades at random intervals of 0, 10, 20, 30 and 45 degrees respectively.

With reference to the drawings, the rudder comprises of the main or primary rudder blade 2 and secondary rudder blade 3. Attached to the leading edge of the primary rudder blade is the round sectioned flow diverter 1. The primary blade 2 is connected to secondary blade 3 by means of the hinge components comprising of hinge bosses 4 and hinge swivel shaft 5 and inter boss wear washers 7.

The secondary rudder blade 3 is free to swivel about the hinged rear edge of the primary rudder blade 2. Attached to the secondary blade are the fins 8.

The rudder unit complete is mounted to the vessel by means of rudder stock 9 via rudder flange 16 and lower rudder pintle shaft 6.

The swivel block 11 is supported by the swivel bushes 12 which are in turn supported by suitable fixing or fabrication 10 to the vessels hull. The fixing or fabrication 10 is to be individually constructed and moulded to the contours of each individual vessels hull shape which will not be unique. The swivel block 11 and associated slide bearing bush 15 are free to rotate in a horizontal plane and the slide bar 13 is guided in relative angular movement by this assembly. The slide bar 13 is retained in the aperture provided in the secondary rudder blade by retaining nut 14 and is also free to slide through the slide bearing bush 15 which is housed in swivel block 11. All swivel and secondary blade control components can alternatively be mounted at the lower edge of the rudder unit by vertical reversal of the secondary blade 3 and items inclusive of 13, 14, 11, 12, 15 and 10.

When the primary rudder blade 2 is angularly rotated by means of the vessels steering gear through rudder stock 9 the hinge section 4, 5 and 7 is lateraly displaced from the vessels centreline.

This movement also causes the secondary rudder blade 3 to be displaced by the same amount. The result of this action and due to the compound angular displacement of the secondary rudder blade and movement control exerted by the slide bar 13 and associated components 11, 15, 10 and 12 the resulting angular motion obtained by the secondary rudder blade 3 is maintained at double the angle of the primary rudder blade over the whole rudder travel from 0 to 45 degrees on each side of the vessels longnitudinal centre line.

Claims (5)

1. l..A vessels steering rudder comprising of both a primary blade connected and supported by suitable means to the vessels steering gear, and a secondary control blade, the secondary blade attached by means of a hinge to the primary blade, a hull mounted control linkage determining the relative angular position of the secondary blade to the main primary blade, a round sectioned flow diverter mounted to the leading edge of the primary rudder blade and a series of flow entrapment fins attached laterally in horizontal attitude to the secondary rudder blade control surfaces.
2. 2..A vessels steering rudder as claimed in Claim 1 wherein the primary blade consists of a flat plate or compound curved hollow fabrication, provided with means of adequate mechanical support to the vessels normal steering gear shaft, by means of an upper rudder mounted supporting arrangement, the upper support utilised as both support and to exert rudder turning torque to the primary blade in both lateral angular directions to each side of the vessels longnitudinal centre line, the primary blade supported additionally both laterally and vertically by means of a lower pintle bearing or support, though not excluding applications in which no requirement for the use of a lower support pintle bearing exists, being subsequently mounted and directly supported by a single top mounting arrangement.A round sectioned flow control diverter attached to the leading edge of the primary rudder blade, providing controlled hydrodynamic flow balance and redirection of apparent angular fluid attack at the rudders nose area prior passage over primary blade main control surfaces during higher rudder operating angles. Achieved by means of a self regulating hydraulic wedge, providing captive boundary layer generation and flow smoothing conditions around the leading edge and loaded primary rudder surfaces.
3. 3.,A vessels steering rudder as claimed in Claim 1 or Claim 2 wherein a sliding bar and pivot control linkage holds in angular position and controls the secondary rudder blade at a predetermined angular relationship to the primary rudder blade, resulting in a compounded angle at the secondary rudder blade of a greater angle than that of the primary rudder blade angle as at any time may be determined by the vessels normal steering gear, when both the primary and secondary blade angles are caused to be measured from the vessels longnitudinal centre line.
4. 4..A vessels steering rudder as claimed in Claim 1 or Claim 2 or in Claim 3 wherein the secondary blade consists of a flat plate or compound curved hollow fabrication attached to the primary blade by means of a supporting hinge, the hinge attached by means of suitable bosses at alternate fixing points to both the trailing edge of the primary rudder blade and to the leading edge of the secondary rudder blade providing means of permitting partial rotation about the hinge. Fixed to the secondary rudder blade on both control surface sides, a series of flat section turblence control fins mounted on a longnitudinal edge in a horizontal attitude relative to the normalised fluid directional flow and being equally spaced vertically over the control surface vertical surfaces, with the lower and uppermost end fins fixed close. to the secondary rudder control blade edges on both sides of the secondary control surface.
5. 5..A vessles steering rudder substantially as described heroin with reference to Figures 1-4 of the accompanying drawings.