Technical Field

The present invention relates generally to a slider assembly for lowering and raising a mast, the mast being pivotable at its base, and relates particularly, though not exclusively, to a slider assembly for lowering and raising a yacht's mast.

Background Art

There are a variety of situations where it is necessary to lower or raise a yacht's mast. For example, with a trailerable yacht, where overhead powerlines need to be avoided, the mast must be lowered prior to trailering. In another instance where a yacht is to motor under a bridge it may be necessary to lower the mast to ensure the mast clears the bridge as the yacht passes under it. Where it is necessary to go aloft to service or repair a yacht's mast it may be preferable to lower the mast so the work can be performed on the mast at deck level.

A number of methods are presently used for lowering a yacht's mast to a position so that it is substantially parallel to a yacht's deck. A common method, particularly in Western Australia, uses the forestay, which is typically a wire cable, to lower and raise the mast, together with a block and tackle system connected to the bow of the yacht. To increase the angle of the forestay relative to the mast, a bipod is set up, typically using two spinnaker poles, between the bow of the yacht and the mast base. One end of each spinnaker pole is coupled to the deck outboard of each sidestay, respectively, and an opposite end of each pole connects to a forestay guide. The apex of the bipod is thus connected to the forestay guide. With the block and tackle system connected at one end to the bow and at the other end to the forestay, the forestay is then disconnected from the bow. The mast, pivotally connected

to the yacht at the mast base, is then progressively lowered to the deck by easing the block and tackle system.

Once the mast is lowered it may be disconnected from the yacht at the base and moved toward the bow of the yacht. In this position it may be secured for transportation or worked on as required. The procedure for raising the mast is the reverse of that described above except the block and tackle system is pulled so as to raise the mast into an upright position.

As can be appreciated, this method for lowering and raising a yacht's mast is time consuming and requires at least two people to perform expediently. A certain degree of skill and expertise is also required to ensure that the procedure is carried out safely without risk of injury to an operator or damage to the yacht or the mast.

Furthermore, where adverse weather conditions are present, such as high winds and/or rough water conditions, the mast is vulnerable to moving in an athwartship and/or fore and aft direction. This may result in injury to an operator or damage to the yacht, such as twisting of the mast base where it pivotally connects to the yacht.

Disclosure of Invention

An intention of the present invention is to provide a slider assembly for lowering and raising a mast expediently, with relative ease and safety.

According to the present invention there is provided a slider assembly for lowering and raising a mast, the mast being pivotable about its base, the slider assembly comprising: a slider adapted to slidably engage the mast, the slider being adapted to be pivotally connected to one end of an elongate member, the opposite end of the elongate

member being adapted to be pivotally connected to a first remote anchor point whereby, in use, as the slider is slidably moved relative to the mast, the elongate member can pivot about the first remote anchor point and force the mast via the slider to pivot about its base to a raised or a lowered position.

Preferably, said elongate member is one of a pair of elongate members, the second member being pivotally connected at one end to the slider and adapted to be pivotally connected at an opposite end to a second remote anchor point, each remote anchor point being located on opposite sides of a pivot plane the mast defines during pivotal movement whereby, in use, lateral movement of the mast either side of the pivot plane is substantially restricted by the pair of members.

Typically, the slider assembly further comprises means for slidably moving the slider relative to the mast said means operatively coupled between the slider and a third remote anchor point.

Preferably the slider comprises: a slider body adapted to be coupled to the elongate member; first means for transferring tensile loads in the elongate member to the mast; and second means for transferring compressive loads in the elongate member to the mast, said first and second means each mechanically coupled to the slider body whereby, in use, depending on the load to be transferred to the mast, the first or second means independently bears against the mast thereby reducing friction as the slider moves relative to the mast and the mast pivots about its base.

Typically, the first means for transferring tensile loads in the elongate member to the mast comprises a slide

adapted to slidably move in a longitudinal track of the mast, the slide connected to the slider body so that the slide bears on an internal bearing surface of the track when there are tensile loads in the elongate member.

Typically, the second means for transferring compressive loads in the elongate member to the mast comprises one or more rollers each adapted to bear against an external surface of the mast when there are compressive loads in the elongate member.

Typically, each roller has a circumferential profile that is shaped substantially complementary to the mast profile against which said roller bears.

In one embodiment each roller has a radially extending projection designed in use to be received in a track of a mast, as the slider moves relative to the mast and the mast pivots about its base, so that the slider is guided by the roller in the general direction of the track.

Typically, the elongate member releasably couples to the slider.

In one embodiment the means for slidably moving the slider comprises a downhaul system connected between the slider and the third remote anchor point whereby, in use, movement of the slider is effected by the downhaul system which moves the slider relative to the mast, thereby causing pivotal movement of the mast about its base towards the raised position.

Preferably, the means for slidably moving the slider further comprises a first adjusting means coupled to the downhaul system whereby, in use, movement of the first adjusting means moves the downhaul system.

Alternatively, the downhaul system is connected between the elongate member and the third remote anchor point.

In another embodiment the means for slidably moving the slider comprises an uphaul system connected between the slider and the third remote anchor point whereby, in use, movement of the slider is effected by the uphaul system which moves the slider relative to the mast, thereby causing pivotal movement of the mast about its base towards the lowered position.

Preferably, the means for slidably moving the slider further comprises a second adjusting means coupled to the uphaul system whereby, in use, movement of the second adjusting means moves the uphaul system.

Alternatively, the uphaul system is connected between the elongate member and the third remote anchor point.

Alternatively the first and second adjusting means can be a single adjusting means having two ends, coupled on each end to the downhaul system and the uphaul system respectively whereby, in use, movement of the single adjusting means moves the slider in either an upward or a downward direction relative to the mast thereby pivoting the mast about its base towards the lowered or the raised position, respectively.

Brief Description of Drawings In order to achieve a better understanding of the nature of the present invention a preferred embodiment will now be described in some detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a preferred embodiment of a slider assembly according to the present invention shown in operation on a yacht's mast;

Figure 2 is a side elevational view of a slider of a preferred embodiment of a slider assembly according to the present invention; and

Figure 3 is an end elevational view of the slider shown in Figure 2.

Modes for Carrying Out the Invention

As shown in Figure 1, a slider assembly 10 is provided for lowering and raising a mast, in this embodiment a yacht's mast 12. The yacht's mast 12 is pivotable about its base 14, and is supported by two sidestays 13 and a forestay 15.

The slider assembly 10 of this preferred embodiment comprises a slider 16, a pair of elongate members, in this embodiment a pair of spinnaker poles 18, and a first and second remote anchor point, in this embodiment two rings 19, 20. Each ring 19, 20 is connected to the port and starboard sides, respectively, of a yacht 23.

The slider assembly 10 further comprises a means for slidably moving the slider 16 relative to the mast 12. In this embodiment the means for slidably moving the slider 16 comprises a downhaul system 24 connected between the slider 16 and a third remote anchor point, in this embodiment the deck of the yacht 23, and a first adjusting means, in this embodiment a winch 26, coupled to the downhaul system 24.

As best shown in Figures 2 and 3, the slider 16 comprises a slider body 28, a spinnaker pole coupling 30 for connecting each of the spinnaker poles 18 to the slider body 28, first means for transferring tensile loads in the spinnaker poles 18, and second means for transferring compressive loads in the spinnaker poles 18.

In this form of the present invention the first means for transferring tensile loads in the spinnaker poles 18 to the

mast 12 comprises a slider 32 coupled to the slider body 28. The slider 32 is machined or moulded from nylon and has a track portion 33 sized and shaped to slide and be retained within an internal track 36 of the mast 12 (see Figure 1) . The slider 32 has a body portion 34 formed from a rectangular-shaped nylon block and a nylon web 35 connects the body portion 34 to the track portion 33. The nylon web 35 is of a thickness small enough to exit the track 36 and slide longitudinally along the track 36.

The second means for transferring compressive loads in the spinnaker poles 18 to the mast 12 comprises a pair of wheels 38, each wheel 38 being rotatably mounted on an axle bolt 40.

As best shown in figure 3, the pole coupling 30 comprises two parallel sections 42 spaced to receive the slider body 28, each section 42 welded along an edge to a coupling plate 44, the coupling plate 44 being bent to include two obtuse angles where each section 42 joins the coupling plate 44. The coupling plate 44 has two opposing ear sections 46A, 46B, each ear section having a hole 48 for releasably coupling each of the spinnaker poles 18 to the slider 16. As shown in Figure 2, adjacent an end of each parallel section 42 is a hole 49 for receiving a shackle pin 50 used to pivotally couple the pole coupling 30 to the slider body 28.

The slider body 28 comprises two substantially triangular sections 52A, 52B cranked so that they are configured to form a bifurcated structure 54 designed to receive the body portion 34 of the slider 32 between each prong 55A, 55B of the bifurcated structure 54. Each triangular section 52A,

52B has two elongate holes 56 for receiving a throughgoing bolt 60 for coupling the body portion 34 between each prong 55A, 55B. The body portion 34 of the slider 32 has two

holes 58, each hole being designed to receive the respective bolt 60 and allow the slider 32 to reciprocate relative to the slider body 28 in a direction substantially perpendicular to the direction of movement of the slider 16 relative to the mast 12.

Two holes 68 are provided in each prong 55A, 55B of the slider body 28 for receiving each of the axle bolts 40 which rotatably couple the pair of wheels 38 to the slider body 28. A tubular spacer 70 is used to receive each axle bolt 40 and separate each prong 55A, 55B of the bifurcated structure 54.

In this embodiment each wheel 38 is shaped complementary to the profile of the mast 12 adjacent the internal track 36. Each wheel 38 has a radially extending protrusion 39 which is circular in shape and is adapted to be slidably received in the internal track 36 of the mast 12 and guide the slider 16 along the track 36. Extending axially from opposing surfaces of the protrusion 39 is a conical frustum portion 41 having a circumferential surface designed, in use, to bear on the mast 12 adjacent the track 36. The diameter of the circular protrusion 39 is greater than the largest diameter of the conical frustum portion 41.

The shackle pin 50 threadingly engages a shackle 51 which is connected to the downhaul system 24 and/or an uphaul system (not shown) where this is used. As shown in figure 3, this embodiment of the slider assembly 10 further comprises the winch 26 attached to the yacht 23. The downhaul system 24 of this embodiment comprises a line 76 connected to the shackle 51 which is coupled to the slider 16. The line 76 can be releasably wound around a drum of the winch 26 to assist in moving the slider 16 relative to the mast 12.

With the mast 12 in a substantially upright position, the slider assembly 10 can be operated in the following manner in lowering and then raising the mast 12.

The track portion 33 of the slider 16 is fed into the internal track 36 of the yacht's mast 12. Each of the two spinnaker poles 18 is connected to the respective holes 48, thereby connecting each of the poles 18 to the slider 16. The line 76 is then clipped or tied to the shackle 51 of the slider 16. An opposite end of each of the poles 18 is then connected to the respective rings 19, 20 connected to the port and starboard sides of the yacht 23, respectively. The slider 16 will slidably move up the mast 12 as the poles 18 are connected to the rings 19, 20.

With the line 76 wound around the drum of the winch 26, the forestay 15 can then be disconnected from the bow of the yacht 23. With the forestay 15 disconnected the mast 12 is then free to pivot about its base toward the stern of the yacht 23. By easing the line 76 via the winch 26 the slider 16 moves in a upward direction relative to the mast 12. The mast is gradually inclined toward a substantially horizontal position by progressively easing the line 76. As can best be seen in figure 1, the poles 18 support the mast 12 athwartships or laterally during this procedure. Once the mast 12 is in the substantially horizontal position the mast 12 may be supported by a crutch (not shown) so as to take any load off the slider assembly 10. Furthermore, the mast 12 may be detached from the yacht 23 at its base and moved toward the bow of the yacht 23 for securing thereto.

The procedure for raising the mast 12 is substantially the reverse of that described above. With the base of the mast 12 pivotally coupled to the yacht 23 and the slider assembly 10 set up as if the mast 12 had just been lowered the line 76 is pulled around the drum of the winch 26.

This causes the slider 16 to move in a downward direction relative to the mast 12 and the mast 12 to pivot about its base toward the bow of the yacht 23. Once the sidestays 13 are no longer slack the line 76 can be secured and the forestay 15 connected to the bow. Each of the poles 18 can then be detached from each of the rings 19, 20, the line 76 eased, and the slider 16 lowered to the bottom of the internal track 36 in the mast 12.

As can be appreciated from the raising and lowering procedure herein described the slider 16 will cooperate with the mast 12 depending on the nature of the load in the poles 18. If, for example, there are compressive loads in the . poles 18, as will most typically be the case, the two pair of wheels 38, and in particular the conical frustum portion 41 of the wheels 38, will bear against an aft face of the mast 12. If however there are tensile loads in the poles, where for example the mast is swung toward the bow due to waves acting on the yacht 23, the slider 32 moves relative to the slider body 28 and the wheels 38 no longer bear against the mast 12. The track portion 33 of the slider 32 thus bears against the track 36 in the mast 12, transferring tensile loads from the poles 18 to the mast 12.

Where the mast 12 is likely to pivot toward the bow because of wave and/or wind conditions an uphaul system such as a main halyard (not shown) can be coupled to the slider 16 and fixed to a third remote anchor point, such as a cleat located on deck to prevent movement of the slider 16 in a downward direction. With both the uphaul system and the downhaul system 24 secured, the mast 12 is prevented from pivoting about its base 14.

The slider 16 of this embodiment may be manufactured and sold together with an elongate member or pair of members, but is typically manufactured and sold as a separate item.

A spinnaker pole or pair of spinnaker poles, already resident on the yacht 23, is then used for this purpose, as described in the above embodiment.

Now that a preferred embodiment of the slider assembly has been described in some detail it will be apparent that the preferred embodiment has a number of advantages over the prior art, including:

(1) the procedure for lowering and raising a mast using the slider assembly is relatively simple and can be carried out expediently and safely by a single person;

(2) when in operation the slider assembly provides athwartships or lateral support for the mast; and,

(3) the slider assembly provides a relatively smooth operation when lowering and raising the mast.

It will be apparent to persons skilled in the relevant arts that numerous variations and modifications can be made to the slider assembly in addition to those already mentioned above, without departing from the basic inventive concepts of the present invention. For example, the slider assembly may use a single elongate member anchored to a mainsail traveller rather than using two members as described above. The slider may, depending on the size of the mast and the loads likely to exist during the raising and lowering procedure, be fabricated as a single injection moulded section rather than having the rod and wheel arrangement described. Smaller masts may not in fact require an adjusting means, such as the winch in this embodiment, and may be lowered by hand independent of an adjusting means. Furthermore, the downhaul system may be connected to the elongate member and not the slider as herein described. The slider may include one or more wheels designed to bear on the aft face of a mast or any other means for transferring compressive loads in an elongate member to the mast, such as a solid bearing having a low coefficient of

friction. All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.