CA2326458A1 - Winter ice and snow wind surfing sail powered iceboat convertible to water sailing catamaran - Google Patents

Abstract

An iceboat includes a hull and a perpendicular extending beam attached to the rear end of the hull.
A mast is mounted at or near the centre of gravity rearward of the occupant pilot seat in the hull and supports a wind surfing sail. Skate blade mountable V-hull skis are attached to the front end of the hull and to the outer ends of the side struts beams.
A catamamran includes two outer hulls mounted to a forward and a rearward traversing beam on which is built the deck area. It is rigged and operated as a conventional sailboat and has the capability of sutaining higher wind forces, therefore permitting the effect of hiking one side of the boat out of the water while permitting the retention of directional control.

Description

~~ DESCRIPTION
Construction details The present invention is a lightweight snow and ice sailing boat convertible to a summer use catamaran making use of a hull mounted automatic self leveling hydrofoil anti-cavitation planar wing system. The ice boat's body, side strut and ski and skate assemblies' stiffness are derived from the use of MIG welded, lightweight, rust resistant aluminised and stainless steel metal alloys of round and square tubing. A square tubing central member is continued throughout the fuselage to form the main load bearing system.
The iceboat is built with a rust resistant, painted, metal hull (1) and mast assemblies (2) having a rearward ofupright seated pilot, near centre of gravity wind surfing sail (3) and supporting single mast and boom assembly, which provides unique advmtages over previously devised control systems. It makes advantageous use of a mast mounting system which permits the quick and easy changing of wind surfing sail and mast configurations. It permits the easy removal of the V-hull snow runners assembly (4) and the removal of blade runners (5) for maintenance purposes or for changing the system (6) to summer use by replacing the winter runner assembly with summer catamaran hull assemblies.
The present ice boat includes a hull having forward (7) and rearward (8) ends, and a two section removable beam (9) attached to the rear end of the hull and having first and second pin locked ( 10) dismountable opposed ends extending outwardly from the opposite sides of the hull. A
plurality of dismountable combination skates and V-hull ski assemblies are attached to the hull with one skate assembly attached to the front end of the hull and one skate assembly attached to ._.. each of the first and second ends of the side strut beans.
Rear beam canted runners To prevent adverse effects of rear runner side slip deflection as they angle "out" from wind loading forces on the sail, an outward blade angle of 5 degrees is built in. (11) Adjustable steering rudder foot pedals Rudder pedals ( 12) connected to push tubes ( 13) control the steering of the front runner. A toe push on the right pedal initiates a right turn and a toe push on the left pedal initiates a left turn.
The pedal system can be adjusted by nearly 8 inches in 4 steps ( 14) meaning all users can find the perfect setting. For additional safety, the steering linkage is dual redundant with two push rods either of which can be used to steer the boat in an emergency. It is possible to "heel" a pedal to initiate an opposite direction turn. Convenience is a big factor in making the ice boating experience enjoyable. Convenience not only means simple set up and take down but also means easy car topping and storage. The steering assembly is a simple robust design that can be easily separated from the fuselage. this not only makes the fuselage weigh less. it also takes a lot of the awkwardness out of getting the fuselage on the roof racks or in transportation.
Mast and boom assembly The mast and boom assembly are made of aluminilum tubing type 6061 T-6 or of commercially available carbon composites. All other related hardware materials such as pulleys, ropes, rope guides mast mounting system, seat, seat belt should make use of/and/or polymers, carbon, stainless steel, aluminium, rubber, copper and nylon.

''~' Mast base assembly (15) This assembly interfaces the wind surfing sail mast base with the boat. It uses a standard Chinook type cup. The bottom bracket attaches with six stainless steel screws and allows the sail to be easily put on and taken offthe boat and also allows the sail to rotate out the back of the boat to prevent damage during setup.
Mast stay brace and bracket system (16) Wind surfing sails are designed to be supported at the base ofthe mast and at the boom. The present design mast stay brace bracket systems made from polyurethane with a carbon fiber insert perfectly accomplishes this allowing the sail and mast to twist off as the sail designers intended.
This system allows the mast to rotate with the sail and also distributes the mast downward force between the mast and the brace. The mast brace interf ices with the mast in an area where the mast is reinforced fiuther increasing reliability. The cables and adjusters ( 17) are all quick release and constructed of stainless steel. A camlock buckle ans strap hold the mast in place Also a aluminium mast helper bar ( 18) using a load bearing washer assembly make use of a solid PVC
insert guide shaft to interface the mast bracket and the downhaul sail base cleat.
Bilateral sail sheeting system Sheeting a wind surf sail with the high fixed boom end presents an interesting problem. The bilateral sail sheeting system allows high performance Sheeting of wind surfing sail without modifying them. This system is designed to put sheet forces on the sail in the same manner as the sails were designed for. Bilateral sheeting also allows the sail to be filly sheeted to centre which is important when very high apparent wind angles are achieved. The present design incorporates a novel sheeting system ( 19) which sheets the sail form the ends of the ice boat rear beam rather than from a point in the centre of the boat (20). This sheeting system allows the sail to be sheeted very close to the centre which is important at high speeds where the apparent wind is more straight on. Once the sail is fiilly centre, the sheet begins to flatten the sail which in effect "kicks it into overdrive". To the boat pilot, the sheet works exactly like a sail boat sheet. Pull on the single sheet rope handle to go faster, let offto slow down. A ratcheted car hand brake system with a mechanical push button release system can also be installed in order to permit the setting of ideal constant sheet pull. (21 ) Ski assemblies The ski assemblies (4) are constructed of either painted steel or stainless steel alloys. A UV
inhibitor provides the outer protective coat. The removable skate blades are made of wear resistant stainless steel or of painted or teflon coated metal bottoms with other surfaces painted to prevent corrosion damage. An enclosed rocker system (22) is incorporated at the end ofthe rear beam struts and is mounted at the front steering ski assembly through a vertical bushing fixed (25) through the central beam . This rocker assembly system also provides ski flexibility in order to follow terrain contour. An additional shock absorber (23) ski and frame link is installed behind the front steering system and at the side beam struts to provide a double joint system (26) providing more hull flexibility and therefore the smoothest possible ride. A
spring (24) tensionner is added to the front mast stay brace cable to permit some degree of mast flexibility and for the pilot to apply extra forward raking by hand pulling in order to achieve faster speed.

2 ' SPECIFICATION
Background of the Invention 1. Field of the invention The present invention relates, in general, to sailboats and, more specifically, to iceboats.
2. Description of the Art Iceboats have proven to be a popular type of roiling craft in colder climates.
An iceboat typically includes a small, elongated hull, a beam connected to the rear end of the hull and extending outward from the hull, and three runners of skates, one mounted on a springboard extending forward of the front end of the hull and one on each outer end of the plank. A sail is mounted on a mast and a boom attached to the mast in much the same manner as on a sailboat.
the mast is locate in front of the forward end of the cockpit in the hull.
However, the forward mounted mast places the sail in a location generally in front of and to the side of the occupant in the cockpit which has a tendency to block the view to one side of the iceboat. This could result in a dangerous situation, particularly due to high speeds of iceboats as compared to much slower sailboats in water.
i TECHNICAL DETAILS
Specifications Configuration: Tri-rail, front steered, sit down, rear mount wind surf sail Length: 12 feet Width: 8 feet Weight: 150 pounds including steel runners but without sail rig Clearance ski base: 4 inches above the snow. Blade base : 6 inches above the ice Steering: Direct linkage push rod, adjustable by 12 inches (4 steps) for pilot height Runners: V-hull skis 36" in lenght by two angled faces of 6"each in width with 30" runner blades.
Strut/runner linkage: in house rocker design with optional strut/rocker mounted shock asbsorber Sheeting: Bilateral with single sheet control rope Hardware: Harken, Race Lite Body, front and rear beams: Aluminised, stainless steel alloys, painted steel, IJV final coat Max. capacity: One rider, 300 pounds Mast base compatibility: in house articulated mast height adjustable base cup Adjustable boom outbaul The boom has 1 inch adjustment increments with the nominal 10% draft position shown as boom position "0". For light winds, optimum performance is achieved by shortening the boom to the .,...._ "-1'" position which results in a fiiller sail. On the other hand, if the wind picks up, higher speed and pointing ability may be achieved by lengthening thv boom to the "+ 1"
position . On large sails it may be preferable to experiment with shortenin; the boom to the "-2"
position in very light winds. Outhaul adjustments done with the sailing rig mounted on the ice boat.
the outhaul is not adjustable while sailing but its an easy adjustment that can be done at any time with the boat stopped.
Adjustable sail outhaul On the fly performance is increase with an adjustable outhaul built in to the boom's rear end. A
"suspension rope" is installed about 5 to 6 inches from the boom's end. On both sides of the location 5/16" holes are drilled and copper tubing is inserted and the ends are flanged to reduce the rope wear and abrasion. The suspension rope goes through the "eye" of the sail rear and keeps the boom end from excessively drooping when the outhaul is let way out. The suspension rope should be loose enough to allow the outhaul to travel on the order of 4 inches.
The outhaul adjuster rope is run through the "eye" of the sail, through a block attached to the rear of the boom (Harken 224 Micro Block) for a '?:1 leverage, then up towards the front of the boom At the maximum width of the boom, a custom "eye" routes the rope to follow the contour of the boom. The rope goes to another block (Harken 224) attached to the front of the boom and then is routed down to a cleat attached to the mast helper tube. From this position, the pilot can easily reach up and grab the sheet adjuster while sailing to best trim the outhaul or the rope can be linked to a ratcheted push button release car hand brake to adjust best outhaul trim. A
four to one pulley advantage can also make adjustment easier.

Finally, addtional descriptions, specifications and techtucal drawings are to be submitted shortly.
More information will be added through specific parts detailed drawings and with further information on hydrofoil catamaran. The easy removal without tools of the Winter use ski and blade system will be described as well as the method for replacing said system with Summer use hydrofoil catamaran hulls and rudder system. The hydrofoil system will permit speeds equivalent to the winter use ski system.

Claims

Dynamic balancing Claim 1 In theory, there is a positive interaction between a forward pilot and a rear sail arrangement. A
large low pressure area is created by the sail and this is what gives it lift.
This low pressure area can also pull air from areas above and below the sail resulting in lateral air flow. This only damages the sail lift. However, in the present design, the pilot in front of the sail creates a low pressure area behind the pilot which acts to shut off air flow from the bottom of the sail (same effect as closing the gap). Also, the sail area behind the pilot probably isn't generating much lift but it does have an effect on reducing the pilot drag - and possibly a significant effect. You can also see this on many subsonic craft where the nose is relatively blunt but the trailing edge is very streamlined. Also, a low rigged sail may generate slightly less power but seems to have a significant effect on both pilot and sail drag resulting in an improved overall lift to drag ratio.
Claim 2 There is a trade-off on where to place the boat's centre of gravity (cg).
Having the (cg) forward helps the manoeuvrability and high wind safety, keeping it back results in better leverage to keep the boat from hiking in lighter winds where the mast downward pressure isn't as significant.
Stable turning is achieved because the cg is place 1/3 from the boat rear (2/3 from the front) which results in equal weight on all three runners. This gives maximum possible runner weight while insuring stable steering under all conditions.
Claim 3 The sail mast downward pressure location (where the mast attaches to the fuselage) is placed as close to the boats cg as possible the reason for this is that the mast can exert a huge downward force on the fuselage and being a force just like the pilots weight, it can shift the boat's centre of gravity towards the masts down force location. By placing the mast down force near the boat's cg, the "dynamic" cg of the rear sail boat shifts very little during sailing. This is the main reason that "spinout" or "flicker" is nearly eliminated in this configuration. One of the most fun manoeuvres is a high speed down wind turn in windy conditions. But this can also create the highest mast downward pressure. Since the mast down pressure is nearly over the static cg, the balancing between the sail centre of effort (ce) and the boat's cg remains nearly stable and fixed. And, since the mast down pressure is behind the boat cg, the stable steering condition of more pressure on the rear runners is also maintained. A big shift in boat cg and front runner loading during windy conditions is what causes spinout and both of these effects are almost eliminated in the rear sail design.
Claim 4 Finally, the sail ce is placed relative to the boat's cg. This is important for both performance and safety. The boat cg is important as this is where a force applied to the boat will cause it to slide exactly sideways. Apply the force in front of the cg and the front of the boat slides, apply the force behind the cg and the rear of the boat slides. For safety, you always want to apply the sail force behind the boat's cg as you can control a boat with the rear sliding but its much more difficult (and dangerous) with the front sliding. A rear sail boat inherently has the sail ce behind the boat cg so will be safe. - i.e., the rear end will always get blown down wind but you can still steer the boat. However, for performance, you want the sail ce to be relatively close to the boats cg (but still behind). This is of course done by raking the rear sail forward.
(see drawing no.4) Claim 5 Forward raked foils can be powerful but unstable on aircraft. However, in this case they are stable and the reason is that the entire sail area is behind the sails rotational axis. Also, normally the pilot will be leaning slightly to the windward side of the boat in order to gain maximum leverage from his or her weight. This puts the pilot out of the way of the forward raked mast.
Claim 6 Hiking occurs when the up wind runner lifts because of torque on the boat.
Weight over the rear axle or beam makes the boat less susceptible to hiking and also lets you get more power out of the sail. In light winds. there is less weight on the rear beam than on a front sail configuration and this makes the boat more prone to hiking in light wind. However, as the mast downward force increases due to higher winds, the pressure on the rear axle can become greater for the "rear sail"
yacht. It would seem that the stability of the rear sail yacht almost increases in higher winds. The geometry of the rear sail, forward pilot boat requires a significantly higher drag lifting force on the sail to lift the front end.
Claim 7 A near but behind cg positioned mast produces a boat with good performance in light wind but that is exceptionally controllable in higher winds provides much greater front of mast upright seating comfort for the pilot. Also there is virtually nothing blocking a fill front view making it also easy to look to the rear before initiating a tack or jibe. It is also very easy to see the pilot making hand signalling before turning. The contoured seat belted seat and the adjustable foot pedals (12 inches in 3 inch steps) allows for a very comfortable stance.
Claim 8 The main goal of this unique mast position balancing is to place the sail nearest the centre of gravity with a small amount of "weather helm" for safety. This is achieved on this boat by raking the sail forward. However, the extremely interesting thing is that the mast downward pressure is nearly over the boats static centre of gravity resulting in the boats balancing being stable even under wild sailing conditions. The front pilot weight not only results in a nimble boat but also in combination with the rear sail, keeps the front end on the ice and in control in the bigger winds. It would also be desirable to provide a forward raked rear mast iceboat in which the mast position provides a weight distribution which makes it easier to turn the iceboat than in "standard design"
iceboats. With the rear mounted sail and the geometry of the boat, there is nearly equal weight on each runner. This creates higher proportional weight on the front runner with exceptional turning results.
Claim 9 The present design includes a system to permit the ea:,y adjustment or dismount and change of the wind surfing type mast, boom and sail size combinations in order to take advantage of current wind conditions in effect and to reduce excessive hiking, although a certain amount of hiking is a desirable characteristic sought by many ice boaters. The basic design of the iceboat makes it practically impossible to tip over and in such an event, safety features such as secured mast rigidity are built in to prevent injury to the seat belted motorcycle helmet wearing pilot. Because the sail sits behind the pilot, weight distribution is equal on all three runners producing handling characteristics car designers would envy.