GB2226800A - Demountable, powered furling system for a sailing boat - Google Patents

Abstract

A demountable powered system for supplementing or replacing existing manually operated headsail reefing or furling gear on a sailing boat, comprises a motor 19 mounted on a housing 20 which is designed to slip up and over the existing fourstay and engaged with the boss to which the manual drum is coupled. <IMAGE>

Description

DEMOUNTABLE POWERED FURLING SYSTEM This invention relates to improvements in sail reefing systems for boats and in particular to a demountable powered system for reefing or furling sails such as head sails or main or mizzen sails.

Both manual and powered systems for reefing head and main sails for boats are known although powered systems are a relatively recent innovation and normally restricted to larger vessels of 20 metres LOA or more.

Manual systems have been developed from the original Wyckham-Marten gear which was probably the first type of furling gear for head sails successfully used on small yachts of LOA 7 metres and more. Modern forms of furling gear usually comprise a drum rotable about and/or with the forestay and means to receive the luff of a sail which is wound round said means by hauling on a line which has previously been wound round the drum on setting the sail, thereby furling or reefing the sail to a predetermined position. The means for receiving the luff of a sail usually comprises an aluminium aerofoil section having a groove to receive the luff, the foil either having a wire forestay passing through a bore in the foil or serving as the forestay itself.

The tack of the sail is shackled to the drum which is coupled to the aerofoil section, the forestay being connected to a plate on the deck by means of a bottlescrew or forestay tensioner. This results in the foot of the sail when set being some distance from the deck. In modern cruiser/racer yachts where deck sweeping genoas are used to increase sailing efficiency and drive when racing and where headsail reefing is not required, split-drums are often used which can be removed from the forestay, the tack of the sail then being shackled directly to the deck. On reverting to cruising when a boat is often short-handed, the drum can be secured back around the forestay, thereby enabling the sail to be reefed when required.

With powered reefing systems, two types have generally been available, one using an hydraulic motor and the other an electric motor. The hydraulic motor is usually mounted at a position remote from the sail to be reefed or furled and is coupled via hydraulic lines to a drive system on the stay on which the luff of the sail is set. The electric motor is usually mounted in a housing having gears coupling the motor directly to the drive system which in turn is coupled to a foil on which the sail is set. Both such systems are characterised by being permanently coupled to the luff support for the sail the system is intended to reef or furl.

It is an object therefore of the present invention to provide a powered reefing or furling system for sails which is demountable so that it can be mounted or removed from an existing reefing or furling gear having a luff support member such as a foil rotatably mounted on or with the forestay of a yacht, thereby overcoming the disadvantage of the permanent mounting of previous powered systems and enabling other sails to be set on the foil or forestay such as the deck sweeping genoas described above in relation to manual systems.

According to this invention therefore we provide a demountable powered furling or reefing system comprising a motor, a drive unit, and a housing incorporating said drive unit, characterised in that said housing is adapted for mounting on an existing manual sail furling or reefing gear which includes a luff support member to enable said drive unit to transmit drive from said motor to said luff support member thereby enabling a sail set thereon to be reefed or furled.

Using a system in accordance with this invention on an existing manual head sail reefing gear, it is only necessary to unshackle the existing gear from the deck whilst supporting the mast with a spare halliard as a temporary forestay, removing the existing drum from around the forestay, slipping the housing over the forestay to engage the drive unit with the luff support member and reshackling the gear back to the deck fitting. To avoid having to unshackle the existing gear, the drive unit may incorporate a split drive gear to encompass an existing fitting on or about the forestay and coupled to the luff support member said housing having a split section about the split gear so that only the existing drum needs to be removed and the split drive gear secured to the fitting and the split housing assembled about the split drive gear and fitting.

Whilst systems according to this invention are admirably suited to powering existing manual head sail reefing gear, they may also be used to power existing main and mizzen sail reefing gear when such gear incorporates a rotable luff support member.

In order that the invention may be fully understood preferred embodiments thereof will now be described with reference to the accompanying drawings in which:- Figure 1 shows a typical prior art headsail reefing gear; Figure 2 shows the gear of Figure 1 with the drum removed and an alternative form of drum; Figure 3 shows a demountable powered furling or reefing system in accordance with this invention mounted on the existing gear shown in Figures 1 and 2; Figure 4 is a cross-sectional view of the demountable powered reefing system illustrated in Figure 3, and Figure 5 is a cut-away sectional view of the system in Figure 4.

Referring now to Figure 1, this known form of headsail reefing gear 1 comprises a luff support member in the form of an aluminium aerofoil section 2 having a groove (not shown) into which is slid the luff 3 of a headsail 4, the tack 5 at the foot 6 being shackled by a shackle 7 to a hook 8 welded to the upper portion of a cylindrical boss 9, the welded portion of the hook 8 being received within a slot in the bore of a drum 10 about which is wound a line 11 passing through an eye 12 mounted on a fair-lead guide arm 13 having an annular portion 14 encompassing and secured to that end of a forestay tensioner 15 which is rotatably mounted in a bearing in the bottom end of the boss 9, the other end of the tensioner 15 being connected by another shackle 16 to a deck fitting.The foil 2, together with the drum 10 and boss 9, rotate relative to the tensioner 15 so that on hauling in the line 11 the sail is wound round the foil 2. A wire forestay (not shown) is swagged to a fitting extending from the top of the boss 9 into the bottom section of the foil 2 which has a bore to accommodate the forestay whose distal end is swagged into a fitting rotably mounted into a swivel head attached to the head of the mast.

Figure 2 shows the reefing gear of Figure 1 but with the drum 10 and guide-arm 13 removed from the tensioner 15. Also illustrated is an alternative form of drum which is split into two halves, 10A and 10B, which can be clamped to the boss 9 by means of a screw 16. Likewise, the guide arm 13 is split into two sections, 13A and 13B, the latter having upstands 17A, and 17B on which can be mounted a semi-circular guard assembly and the former Section 13A carries the eye 12, two sections being bolted together on the bottle screw by a bolt 18.

It will be appreciated that the above described furling gear is one of many different types whose construction varies, but all have in common a drum and means for coupling the drum to the luff of a sail to be reefed or furled.

Figure 3 shows a demountable powered furling or reefing systems in accordance with this invention mounted on the manual reefing gear 1 illustrated in Figures 1 and 2. This system basically comprises an electric motor 19 mounted on a housing 20 which incorporates a drive unit 21 shown in detail in Figure 4, the housing being maintained in position about the boss 9 by means of a collar 22 secured by grub screws 23 to the top end of the tensioner 15, the lower end being secured to a stem head fitting 24 by the shackle 16. A torque arm 25 is fixed at one end to the motor and at the other end to a deck fitting (not shown) to prevent the motor and housing rotating about the boss 9.

The demountable powered furling or reefing system shown in Figure 3 is illustrated in more detail in Figures 4 and 5. The motor 19 includes a lower end cap 27 from which projects a lug 28 with a cylindrical head 29 received with a block 30 to which is pivitoly connected a U-shaped member 31 screwed into one end of the torque arm 25 and secured in position by a lock nut 32.

An upper end cap 33 of the motor 19 has a centrally located externally threaded member 34 through which projects a drive shaft having secured thereto a bevel gear 35. The member 34 screws into an aperture 36 in the base 37 of the housing 20 in which is journalled a shaft 38 having secured thereto a worm 39 and a bevel gear 40 in mesh with the bevel gear 35. The worm 39 engages a worm wheel 41 formed on and being integral with a cup-shaped member 42 rotably seated in housing 20 by means of a lower-journal needle race 43, a needle thrust race 44 and a combined thrust and journal bearing 45 located between circlips 46 and 47. Lip seals 48 and 49 about the upper and lower sections of the cup 42 prevent ingress of moisture to the interior of the housing 20.The bevel gears 35 and 40, worm 39 and worm wheel 41 form the drive unit 21 which is non-reversing in the sense that no rotational force exerted by the cup 42 and thereby the worm wheel 41 in a direction opposite to the direction of drive imparted by bevel gear 35 will cause it to reverse. The worm wheel 41 may, alternatively, be formed as a separate annular gear wheel and secured to the outer wall of the cup shaped member 42 by grub screws.

The hook 8 welded to the upper portion 50 of the boss 9 couples it to the cup 42 by engaging in a slot 51 therein. A top plate 52 secured to the wall 53 by means of bolts 54 closes off the interior of the housing 20 containing the drive unit 21. A rectangular bore 60 is provided in the end of the shaft 38 to accept a complimentary shaped handle to rotate the worm 39 and thereby the worm wheel 41, member 42, boss 9 and thereby the foil 2 to furl the sail 4 should the motor 19 fail.

The motor 19 further includes an inner housing 55 contained between end caps 27 and 33 and located within an outer housing 56, to which is attached an outer end cap 57 having the lug 28 projecting there-through. Seals 58 and 59 are provided to prevent ingress of moisture to the motor. Electrical connections from the motor are taken out of the motor housing through a gland nut and down into the interior of the vessel through a water-proof plug for connection to the vessel's electrical supply system.

To mount the system in accordance with this invention to an existing manual headsail furling and reefing gear, a spare halliard is first rigged to act as a forestay, the tensioner 15 unshackled from the stem head fitting 24, the drum 10 and guide arm 13 removed from the boss 9, and tensioner 15 respectively, the housing 20 slid up over the tensioner 15 and onto the boss 9 so that the hook 8 thereon engages in the slot 51 of the cup shaped member 42, the housing 20 being retained in that position by the collar 23 being secured to the upper end of the tensioner 15 which is reshackled to the stem head fitting 24 and the torque arm 25 is connected to the aforementioned deck fitting.Since the tack 5 of the headsail 4 whose luff is received in the aerofoil section 2 is shackled to the hook 8 which engages the cup shaped member 42, the motor 19 will provide drive through the drive unit 21 formed by bevel gears 35 and 40, worm 39 and worm wheel 41 on the cup shaped member 42, to wind the sail 4 about the foil 2, thereby reefing the sail to a predetermined position or, if required, completely furling the sail to a stowed position. No bracking torque is necessary to prevent the sail pulling out from its predetermined reefed position since the drive formed by the bevel gears, worm and worm gear is non-reversing as previously explained.

To demount the system from the existing reefing gear, it is only necessary to remove the collar 23 after first setting up a temporary forestay and unshackling the tensioner 15 and slipping the housing 20 together with the motor off the boss 9.

To facilitate mounting and demounting the powered reefing system without the need to unshackle the existing gear, both the cup and its worm wheel and that part of the housing containing them can be formed as split units, the cup replacing the split drum 10A and 10B.

Furthermore such demountable powered furling or reefing systems can be used on main or mizzen sails where a coupling is provided between the luff support member into which the luff of a main or mizzen sail is fed and the drive unit of this invention.

Claims (9)

1. A demountable powered furling or reefing system comprising a motor, a drive unit1 and a housing incorporating said drive unit, characterised in that said housing is adapted for mounting on existing manual sail furling or reefing gear which includes a luff support member to enable said motor to transmit drive from said motor to said luff support member, thereby enabling a sail set thereon to be reefed or furled.

2. A system as claimed in Claim 1 in which said drive unit includes a cup shaped member rotably seated in said housing and having means for driving engagement with said motor, said member being adapted to receive said luff support member and means enabling said cup-shaped member to be coupled to said luff support member so that said members rotate together when said motor is energised.

3. A system as claimed in Claim 2 wherein said driving engagement means comprises an annular worm wheel and said drive unit includes a worm coupled to said motor and engaging said worm wheel.

4. A system as claimed in Claim 3 including seals engaging each end of said cup-shaped member and mounted within the said housing to prevent ingress of water thereto.

5. A system as claimed in Claim 4 wherein said worm has at one end thereof a first bevelled gear and said motor includes a shaft and a second bevelled gear mounted on said shaft and meshing with said first bevelled gear.

6. A system as claimed in Claim 5 wherein said motor includes first and second end caps, an inner housing contained between said end caps, an outer housing, an outer end cap, and seals between the said outer end cap and said outer housing and said drive unit into which said shaft projects to prevent ingress of moisture to said motor.

7. A system as claimed in any one of Claims 2-6 in which said drive unit housing and said cup-shaped member are each formed into separable parts which are adapted to be coupled together about said luff support member, thereby allowing drive to be imparted thereto by said motor.

8. On a sailing vessel having headsail reefing or furling gear including a reefing drum in which a headsail luff support member rotatable by said drum is secured between a bow fitting and the main mast; a demountable power unit adapted to replace said drum and comprising a motor, a drive unit, and a housing incorporating said drive unit, which includes means for coupling said motor to said luff support member to rotate the latter on energisation of the former.

9. A demountable powered furling or reefing system substantially as described herein with reference to the accompanying drawings.