GB2362356A - Fully retractable keel comprising two or more separate segments - Google Patents

Abstract

A fully retractable keel for a vessel comprises two or more pivotally mounted segments 1 and 2 which can be raised or lowered dependently or independently of one another to or from a housing 4 in the vessels hull. Means for raising, lowering and locking the keel in the fully extended or retracted positions are also provided. The keel may be wholly or partially retracted while the housing means may cooperate with pivotal 5 or sliding 6 guide means to restrict the rate of movement of the keel segments. The keel segments may be ballasted and may be adapted to interlink adjacent faces (Fig 4) when fully extended to form a keel or streamlined foil section.

Description

2362356 (Space-Saver Retracting Keel) This invention relates to

retractable yacht keel.

The use of a retractable keel is common practice to enable a vessel to be less restricted by it's draft whilst retaining, in deeper water, the operating.1 performance advantages of a conventional Fixed fin keel. Retractable keels simplify the launching and recovery of a vessel. increase manae-eability on land (towing) and for most types offer the possibility for a vessel to be beached, allowed to dry out. with a greatly reduced risk of damage.

Retractable / Swing keels comprise a fin type keel (ballasted or otherwise) which can be wholly or partly Withdrawn into, or swung up under., the hull of the vessel and whereby reduce the vessels draft. Fully retractable keels impose large restrictions on the available / usable internal space of the vessel but offer maximum protection to the keel when fully raised, as such the craft can be beached more readily and a less complex trailer or storage cradle is required. Reduction in the size of the keel reduces encroachment into the mterral space but also results in a loss of performance. Swing or partially retractable keels reduce the internal space requirements but at the expense of leaving the keel wholly or partly exposed beneath the hull and thus more vulnerable to damaae.

According to the present invention there is provided a fully retractable keel comprising of two or more separate segments, means for allowing the keel segments to retract dependently or independently of one another, a housing into which the keel segments are retracted in a more space efficient (unobtrusive) and practical manner, pivoting means for securing the keel segments to the hull of the vessel, means to control the raising and lowering of the keel segments and means for securing the keel in the fully extended and retracted positions.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:- Fig, 1.

t Fig 2.

Fig 3.

Fig 4.

Fig 5.

Fig 6.

Shows a Ions-ntudinal section through the hull of a vessel with the keel in the fully raised position, Shows a longitudinal section through the hull of a vessel with the keel in the half extended / lowered position.

Shows a longitudinal section through the hull of a vessel W]. th the keel in the fully lowered / extended position.

Illustrates a typical horizontal section through the keel.

Illustrates a vanation of the invention, a retractable keel comprised of three jointed segments.

Illustrates a variation of the invention, a retractable keel comprised of two unjointed segments.

Y - J_ With reference to the drawing the keel consists of two segments, which are W connected via a pivotingjoint at the lower end of the keel (3). The leading segment ( 1) is secured within the centreboard housing (4) by a pivoting mechanism (5). The trailing segment (2) is located by a sliding pivot mechanism (6) and a guide-way (7) as shown in Fig 1.

In order to lower /extend the keel the control mechanism, omitted for clarity, is operated allowing. both keel segments (1) & (2) to pivot downward, segment (1) moving in the direction of arrow (8). The sliding pivot (6) allows segment (2) to move towards segment (1), in the direction of arrow (9), according to the path dictated by the guide-way (7) as shown in Fig 2.

Once fully extended, as shown in Fig 3, the keel segments (1) & (2) are secured in position by a locking device, not shown, such that the two keel segments are able to function in the same manner as a conventional fin keel. In order to fulfil structural requirements provision for the adjacent segment faces to interlink is included whereby arresting any sideways movement as shown in Fig, 4.

Raising the keel is the straightforward reversal of the lowering procedure.

Fig 5 shows one specific variation of the invention in which the keel consists of three segments. The leading and trailing segments (12) & (14) are located in the housing (4) by sliding plvotjolnts (6) and guideway (7). Segments (12) & 14) are connected to the central segment ( 0 3) at the lower end by pivot joints (3) as illustrated. The central segment (I _3 3) is raised and lowered in the direction of arrow (15), control means omitted, and directly controls the positioning of segments (12) & (14). Segments (12) & (14) move in the direction of arrow (16) & - 17) in much the same way as described for segment (2) in the above. As with the above the adjacent faces of the segments (12), (133) & (14) may be required to interlink as described by faces (10) and (11).

Fig 6 shows one specific variation of the invention in which the keel consists of two segments (18) & (19) which are not directly connected and are able to move independently. Segment (18) is able to move vertically in housing (4) in the direction of arrow (20). Segment (19) is raised and lowered in the direction on arrow (21) rotating on pivot (5). As with the above the adjacent faces of segments (18) & (19) may be required to interlink as described by faces (10) & (11).

A- 0aims 1 A fully retractable keel comprising of two or more separate seginerits, means for allowing the keel segments to be raised and lowered dependently or independently ofone another, a housing into which the keel segments are retracted in a less obtrusive rnanner, pivoting means for securing the keel segments to the vessel, means to control the raising and lowering the keel segments and ineans for securing the keel in the fully extended, fully retracted positions.

Claims (1)

1. A retractable keel as claimed in Claim 1 wherein, the keel segments can be

   wholly or partially withdrawn into a vessels hull or underwater structure.

   A retractable keel as claimed in Claim 1 or Claim 2, wherein the housing means is to restrain the keel segments in at least one direction.

   A retractable keel as claimed in Claim 2 or Claim 33, wherein catchment means is provided to arrest the movement of the keel segments, 5, A retractable keel as claimed in Claim 33 or Claim 4, wherein the housing means is adapted to cooperate with a guide means to restrict the rate ofmovement ofthe keel segments.

   6. A retractable ke-el as claimed in any preceding claim, wherem pivotit]2 and or slidine rneans are pros, Ided to control the movement of the keel seil.ments.

   7. A retractable keel as claimed in any preceding claim, wherein the keel se(-)i,nents mav or may not be ballasted.

   8. A retractable keel as clainied in Claim 5 or Claim 6,,hereiri means are pro,1'ded to linterlink the adjacent fiaces ofthe keel segments whell fully lowered.,extended.

   9. A retractable keel as claimed in any preceding claim, wherein each segment may constitute part of a streamlined section such that when fully extended the combined keel se-ments result in a keel of' streamlined foil section.

   10. A retractable keel substantially as described herein with refierence to Fig,ures 1 to 6 of the accompanying drawing.