GB2202804A - Modular boat cradle - Google Patents

Abstract

A boat cradle with legs which pivot and extend to suit varying hull profiles detail 'Z', which when used in conjunction with the cushioned bearer head wedging action detail 'W' will support a wide variety of boats on a robust keel channel detail 'U'. The extension/centre module when required is slotted into place between the end modules to extend the cradle to suit longer or heavier craft therefore enabling the provision of a range of cradles to suit most boats and permit extension should a larger boat be purchased, from a range of standard components or slot in items details 'X' and 'Y', stability is improved by extendable feet detail 'V'. The cradle is dismantlable into easily handlable components which can be easily transported to a new location in a small commercial vehicle, trailer or even the family car with a roof rack.

Description

MODULA CRADLES SPECIFICATION OF YODEL AH 2 FOR PATENT REGISTRATION Definition: A galvanized steel cradle designed to provide static support of mew1ium to large sized boats, while they are stored on land.

Reason for patent application: This cradle incorporates several new features and applications, intended to overcome a variety of problems associated with current methods of supporting boats. The particular items which are being submitted for consideration are: 1. The concept of the entire structure bolting together from compact, easily handled components.

2. Tbe staggered pitch of the adjustment holes in the telescopic support legs.

3. A completely new design of bearer assembly.

4. Extending stabilisers.

5. The provision of an extension module to enlarge the size and capacity of the cradle.

Problems of existing methods ana structures: Xost arrangements for. supporting boats incur one. or more of the following problems.

1. The use of wooden props and wedges is easy and cheap, but inherently unstable, and has caused many instances of damage due to boats toppling over.

2. All-welded structures provide a fizzed base with braced legs. This is a sturdy arrangement, but due to the bulk and weight involved, causes cons~9erable difficulty and expense when moving to a different storge site.

3. Xost cradles rely on the use of driven wedges to take up the gap between the hull and bearers. This creates point loading, is insecure if several or inappropriate wedges are used, and may damage the surface of the hull.

The alternatives used are either a screwed tube which is slow to adjust and prone to corrosion, or a screw-clamped bar which is also prone to corrosion and has a restricted range of adjustment, as the bar is subject to considerable bending forces and has to be of limited length.

4. Stability with the boat in position is dependent, not on the weight of tbe cradle, but on the breadth of the base. Often the base is too narrow, or if adequate dimensions are achieved, rendered very heavy and bulky.

5. Should the user change to a different or larger boat, it is likely that an alternative cradle will be required.

It is with those problems in mind that the AS 2 cradle was conceived, designed and a prototype constructed. A detailed description of the innovative features and their relevancy to the specified problems follows.

Bolted Construction The intention is to limit each component to a size and weight which can be handled by one person, and to allow the entire cradle to be transported in conponent form in a light commercial vehicle, trailer or estate car.

The use of locating lugs, stubs and bolts is a recognised technique in fabricated structures, but has not, to our knowledge, been applied to achieve this extent of compactness and convenience in boat cradle manufacture. The cradle is delivered in component form and assembled by the user. Stainless steel bolts are used throughout to overcome the problem of corrosion.

Assembly procedure: The base cross-members have locating lugs into which are placed the longitudinal members, for through-bolting. The next step involves the mounting of the feet of the telescopic leg assembly into their lugs at each corner of the base, where they are secured by heavy stainless steel pins. A bearer assembly is placed onto the tube at the top of each leg. Finally the central keel channel is laid onto the base, where it is positively located by its sub-structure and the cross-member lugs.

Telescopic Leg Design In order to accomodate a wide range of boats, the cradle's support legs have to be able to adjust to different shapes and heights of hull. Rapid and precise adjustment through an adequate height range is desirable but not readily obtainable on conventional structures.

The solution developed for the AH 2 cradle uses an inner leg of box-section telescoping within an outer member. The inner leg has regularly pitched boles, but the outer member has several holes of staggered irregular pitch, allowing rapid incremental adjustments to within 1/4" to be made, simply by selecting the approriate hole for insertion of the pin. In addition, the outer member itself, which is of an inverted 'Y' configuration, is supported by a strut which can be adjusted in length by the same telesopic leg and staggered hole pitch arrangement. This enables the angle of the outer member to be varied, increasing the range of support leg positions even further, Bearer Assembly.

The bearers support the sideways load of the boat, and should be able to rotate and tilt to accomodate the curvature of the hull. They should also provide a reasonable platform area over which to distribute the hull load. Current methods employ either: a. A fixed or tilting-only bearer sited at a variable distance from the hull.

Wooden wedges are then driven between the platform and the hull. This applies a point loading to the hull, as well as being an insecure arrangement, and likely to cause abrasion or damage to the hull surface.

or b. A scew-clamped bar with a rubber-padded bearer. This allows rotation and tilting, but the small diameter of the bar permits only a narrow bearer to be fitted. This means that the load has to go onto a small surface area.

Such fittings are really only suitable for light boats.

The bearer assembly for the AH 2 has been developed as a completely new concept, te be used in conjunction with the telescopic legs previously described. It comprises: 1. A central tube drilled to take a pivot-bar through its upper end. The tube fits over and rotates on the smallerdiameter tube at the top of the telescopic leg.

2. Two sections of overlapping channel mounted on the pivot-bar, on which they are free te tilt. The outer channel has a pad of deformable rubber bonded to its upper surface. The hardwood wedge supplied is driven between the two channels, forcing the outer channel against the hull. The rubber pad takes up the shape of the hull as the load is applied. Thus a perfect fit between the bearer and the hull is achieved, distributing the load evenly over all the legs. This represents a major advance.

Extending Stabilisers.

The large surface area of a boat can create considerable windage forces. To improve the stability af the AH 2 cradle even further, without adding unnecessary bulk and weight, outriggers within the outer base cross-members can be withdrawn to increase the base width. These outriggers are lengths of boxsection fitting within the base box-section, where they are held by a throughbolt. This same bolt is used to fix the outrigger in its extended position. A short sleeve on the outer end of the outrigger ensures that it sits at the same level as the base.

Extension Module Although the AH 2 cradle can support a variety of sizes and weights of boat, it has to be limited by its design load. Usually a person who acquires a larger boat has to provide a different cradle to suit. In the event of the capacity of an AH 2 cradle being exceeded, an extension module can be fitted onto the cradle, increasing the base and adding another two legs, with a significant increase in capacity. The extension module can, of course, be supplied at the outset, where larger boats are concerned. The module employs the same base construction, telescopic legs and bearer assemblies as the AH 2 cradle. This system can save the user a great deal of expense, as well as being very convenient.

SUMMARY.

The design aim of the MODULA CRADLE AH 2 is to provide a strong, stable structure for supporting boats on land, without placing undue stresses on the hull, and providing the user with the facility to easily assemble, dismantle, transport or relocate the cradle, should the storage site be changed. The cradle is suitable for a wide variety of boats, and can if necessary be fitted with an extension module, to accept boats larger than the capacity of the standard AH 2 cradle.

MODULA CRADLES PARTS LIST :- PRH2/008/3 ITEM / DESCRIPTION / No OFF/ MATERIIAL / DRG No 1 / SUPPORT CUSHION / 1 / RUBBER 20 THK/ --2 / SUPPORT CHANNEL / 1 / 100X50X8 CHA. / --3 / TUBULAR SWIVEL FIXING / 1 / 41+BORE TUBE / --4 / BEARER HEAD SUPPORT / 1 / AS DRG. / --5 / PRIMARY SUPPORT CHANNEL / 1 / SUB 38X50 A / --6 / HARDWOOD WEDGE / 1 / WOOD / --7 / PIVOT PIN / 1 / S.S. / --8 / WASHER / 2 / 12mm S.S. / --9 / SPACERS / 4 / TO SUIT / -- 10 / SPLIT PIN / 2 / S.S. / -- / / / / / / / / / / / / MODULAR CRADLE DRAWING LIST : PAT. REF. 8700304 DRAWING No / REV / TITLE / / FIGURE 1 / 0 / GA OF FOUR LEG UNIT / / FIGURE 2 / 0 / GA OF SIX LEG UNIT / / FIGURE 3 / 0 / GA OF CENTRE MODULE / / FIGURE 4 / 0 / GA OF END MODULE / / FIGURE 5 / 0 / DETAIL OF INCREMENTAL ADJUSTMENT SYSTEM / / FIGURE 6 0 / DETAIL OF KEEL CHANNEL / / FIGURE 7 / 0 / DETAIL OF EXTENDING STABILISERS / / FIGURE 8 / 0 / DETAIL OF BEARER HEAD / / FIGURE 8.1 / 0 / BEARER HEAD SECTIONS / / FIGURE 9 / 0 / DETAILS OF MODULE JOINT / / FIGURE 10 / 0 / DETAIL OF PIVOTING SUPPORT LEG

Claims (5)

1. CLAIMS 1. A galvanized steel cradle in component form to provide static support of yachts on land, with the provision of support legs allowing independent adjustment for height and beam and incorporating a special bearer mechanism, and with the facility of an optional extension module.
2. 2. A galvanized steel cradle of standardised individual components allowing ease of assembly, dismantling and transportation by one person.
3. 3. A galvanized steel cradle employing pivoting, angled legs.
4. 4. A galvanized steel cradle with incremental adjustment of the telescopic legs secured by locking pins.
5. 5. A galvanized steel cradle with the provision of an optional extension module to increase the size and capacity of the cradle.

   5. A galvanized steel cradle with incremental adjustment of the telescopic struts secured by locking pins.

   6. A galvanized steel cradle with special expanding bearers to be used in conjunction with the legs and struts of claims 4 & 5.

   7. A galvanized steel cradle with built-in stabilisers extending from the base members.

   8. A galvanized steel cradle with the provision of an optional extension module to increase the size and capacity of the cradle.

   Amendments to the claims have been filed as follows AH CRADLE PATENT APPLICATION CLAIXS l. A galvanized steel cradle in component form to provide static support of yachts on land, with the provision of support legs allowing independent adjustment for height and beam and incorporating a special bearer mechanism, and with the facility of an optional extension module.

   2. A galvanized steel cradle of standardised individual components allowing ease of assembly, dismantling and transportation by one person.

   3. A galvanized steel cradle with special expanding bearers to be used in conjunction with the telescopic legs.

   4. A galvanized steel cradle with built-in stabilisers extending from the base members.