NZ529434A

NZ529434A - Wheel tread

Info

Publication number: NZ529434A
Application number: NZ52943403A
Authority: NZ
Inventors: Alan Edward Holt
Original assignee: Jakaar Ind Ltd
Priority date: 2003-11-10
Filing date: 2003-11-10
Publication date: 2005-10-28
Also published as: AU2004222777A1; AU2004222777B2

Abstract

A non-pneumatic treaded wheel, non-pneumatic treaded roller or non-pneumatic treaded tyre wherein the treaded area is a sequence of raised and depressed forms about the rolling perimeter, each raised form being discrete and extending fully from one side to the other of the treaded area of the wheel, roller or tyre and notionally rolling on a flat surface the transition of surface contact from one raised form of the tread to that raised form immediately following about the rolling perimeter is sufficiently immediate so as to be smooth and/or has part of both raised forms making contact and at least substantially the full side to side extent of each raised form but not necessarily simultaneously, will contact such a flat surface during such notional rolling

Description

<div class="application article clearfix" id="description"> 52 ilNTEufiCTUri OF i\L? 2 0 JAN 2005 rfheIVED, NEW ZEALAND PATENTS ACT, 1953 No: 529434 Date: 10 November 2003 COMPLETE SPECIFICATION WHEEL TREAD We, JAKAAR INDUSTRIES LIMITED, a company duly incorporated under the laws of New Zealand of 56 Mahia Road, Manurewa, Auckland, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a wheel, roller or tyre tread. The invention is directed particularly, but not solely, towards wheel treads for the rollers of boat trailers. Conventional wheel treads for wheels or rollers of devices such as trailers, lawnmowers, material conveyors and vehicles etc, may comprise a moulded tread pattern having transverse ribs, having uniform gaps or depressions therebetween, to facilitate traction and drainage. These treads or transverse ribs/raided portions and gaps have the disadvantage of causing significant noise during movement of materials or objects over them, or when moving an object having wheels, over a contracting surface such as the ground. The noise is produced by the moving object hitting or colliding with each consecutive rib. It is also difficult to initiate motion of the object, as the object such as a boat, tends to rest and settle between the ribs within the depression. Moving means that the object must be pushed over and against each rib. The weight of any object combined with the settling of the object between the ribs makes it extremely difficult to initiate motion to overcome existing inertia. It also makes for more effort in general to push or move an object over the wheels or an object having the wheels attached to it. The action of the ribbing colliding and impacting the surface of an object can also cause work hardening of non-plastic objects such as aluminium boats. This has tended to reduce their acceptance in New Zealand whereby flat treads have been preferred. For non-plastic boats such as fibreglass boats, the ribbed treaded wheels are still commonly used. It is the object of the present invention to provide an improved wheel, roller or tyre tread which will obviate or minimise the aforementioned problems in a simple yet effective manner or which will at least provide the public with a useful choice of wheel, roller or tyre tread. The invention consists in or includes a non pneumatic treaded wheel, non pneumatic treaded roller or non pneumatic treaded tyre, wherein the treaded area is characterised in that (A) it is of a sequence of raised and depressed forms about the rolling perimeter, each raised form extending from one side to the other of the treaded area of the wheel, roller or tyre, and (B) where notionally rolling on a flat surface, (i) the transition of surface contact from one raised form of the tread to that raised form immediately following about the rolling perimeter is immediate and/or has part of both raised forms making contact, and (ii) at least substantially the full side to side extent of each raised form, but not necessarily simultaneously, will contact such a flat surface during such notional rolling. Preferably each depressed form at least in area is of a similar shape to the area of its proximate raised forms. Preferably the raised form(s) are at least substantially identical and the proximate raised forms mutually nest in part about the rolling perimeter. Preferably proximate raised forms present, when viewed in silhouette normal to the rotational axis, a substantially straight outline parallel to the actual or notional rotational axis. Preferably the tread has been moulded. Optionally at least some of the raised forms when viewed in area towards the actual or notional rotational axis are curved, S shaped, C shaped, spiral shaped or V shaped. Preferably there is a rim of one material which has a tread of a different and resiliently deformable material moulded thereon. The invention is also a tread as previously defined and substantially as herein described with reference to any one, some or all of the accompanying drawings. The invention also is a wheel having a tread or tyre tread as previously defined. The invention also is a roller having a tread or tyre tread as aforesaid. Preferably the roller is or part of a boat roller. The invention also is a boat support or trailer having at least one roller as aforesaid. Preferably the roller is provided with a rim of one material which has had a tread of a different (and preferably resiliently deformable) material moulded thereon. In preferred forms of the present invention wheels, rollers or the like could, for example, have a first thermoplastics material used to provide a structural form such as a rim preferably with an axle opening and thereafter a compatible but different and preferably more resilient material moulded thereon. By way of example, a rim could be formed from a suitable polypropylene and the tread to be moulded thereon with a degree of thermal adhesion could be of, for example, a TPR thermoplastic rubber. Accordingly in another aspect, the invention consists in a wheel tread, the wheel tread being shaped having at least one of raised portion extending from a base, forming depression therebetween, the arrangement being such that movement of the tread with respect to a contacting surface does not produce noise and/or substantially resist initiating motion resulting in free rolling wheel motion. In another aspect, the invention consists in a wheel tread, the tread including at least one raised portion extending from a base having an arrangement such that constant contact is maintained at all times between the said at least one raised portion and the contacting surface of an object being moved over the raised portion or vice versa. Preferably there are a plurality of raised portions. Preferably the wheel tread has a shape wherein the direction of rotational motion of an object or circumferential direction of the tread defines a longitudinal axis, with the transverse axis being perpendicular to the longitudinal axis, wherein the raised portions are substantially elongate in form, in the transverse direction having a length and a width. Preferably the raised portion extends the full width of the tread. Preferably the raised portions are irregularly shaped such that the width of at least one elongate raised portion is not constant. Preferably the elongate portions in use have an outer contacting surface, side walls and end walls wherein the object contacting surface or surface being contacted by the tread, contacts at least first and second points of one raised portion and a third point of on an adjacent raised portion making three points of contact between the contacting surface and the wheel tread for two raised portions. Alternatively during motion of wheel tread, there are a maximum of three points of contact between the contacting surface and the wheel tread for two raised portions followed by two points of contact on one raised portion followed by one point of contact on one raised portion. Preferably the side walls are curved. Preferably the side walls are angular. Preferably the raised portion or portions are curved, S shaped, C shaped, spiral shaped or V shaped. Preferably the raised portion is continuous around the base of the wheel tread. Preferably the outer surface is substantially planar. Alternatively the outer surface is contoured. Preferably the tread is manufactured substantially from plastics or rubber or any combination thereof. In another aspect, the invention consists in a wheel, the wheel comprising or including a tread and rim, wherein the tread is curved in shape. In another aspect, the invention consists in a wheel, the wheel comprising or including a tread and rim, wherein the tread is irregularly shaped. In another aspect, the invention consists in a wheel, the wheel comprising a tread and rim, wherein the tread is shaped such that impact noise/clicking is significantly reduced and or minimal effort is required to initiation of motion. Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps. As used herein the term "immediate" with respect to transition from one raised form of the tread to that raised form immediately following about the perimeter is sufficiently soon and/or involves regions of both under load so as to not produce noise and/or not substantially resist initiating motion. As used herein the term "and/or" means "and" or "or", or where the circumstances allows, both. As used herein the term "s" following a noun means as is appropriate the plural and/or singular forms of that noun. Reference hereto the "side" of the tread refers to the extent of the tread laterally of the rolling perimeter to the extent to which there is any prospect that the tread can make contact with a said notional flat surface. Preferred forms of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of the wheel or roller tread in use on a typical wheel rim, Figure 2 is a side view of the wheel tread, Figure 3 is a left hand side view of the wheel tread, Figure 4 is a right hand side view of the wheel tread, Figure 5 is a top view of the wheel tread, Figure 6 is a bottom view of the wheel tread, Figure 7 is a second embodiment of a wheel or roller tread in perspective, and Figure 8 is that second embodiment tread- Many regular or irregular forms of tread are capable of satisfying the aims of the present invention which is to minimise noise when in use. In the following two embodiments a fully extensive or substantially fully extensive series of regular raised forms are provided which under compression in use (e.g as a boat roller or as a dolly wheel or the like) will have the effect of ensuring that part or parts of one raised region is on any supporting surface as the weight is being taken on (or is immediately about to be taken on) by a first part or first parts its following raised area. Therefore the terms "nested" or "nest", or variations of it, envisage raised forms sufficiently intermingling or adjacent so that there is or can be (with or without tread deformation) the smooth transition. See lines A-A (Figure 3) and B-B (Figure 8) which show without deformation some prospect of continuity of load bearing at transition. As shown in various view of Figures 1 to 6 the wheel tread 1 is shown on a typical wheel rim 2. This wheel can be part of any vehicle such as a trailer, e.g. for boats or for carrying materials as in a trade trailer, or for lawnmowers, conveyors and other commercial/non commercial use or also a car/truck etc. In use, the longitudinal direction in which the wheel will roll or the circumferential direction of the wheel tread or wheel, as being the longitudinal axis and the transverse axis being perpendicular to this axis and being coincident with the width of a tread and defining the length of the raised portions. Each wheel tread has at least one raised portion 3 extending from a base 4 forming depressions 5 therebetween. There can be a plurality of raised portions forming a plurality of depressions. The outer contacting surface 6 is defined as that surface that contacts the object being moved over or as in other uses, this contacting surface can be the surface over which the wheel can be rolled over such as the ground/floor/planar surface etc. The outer surface can flat or shaped flat/planar or contoured to any shape desired. Further grooves, recesses or profiling can be added to further enhance traction drainage of sand/water and for aesthetics or advertising. Side walls are shown as items 7 and 8 and can be any suitable angle with respect to the base and/or outer surface or can be contoured or curved. Each raised portion can be sized and dimensioned to suit individual requirements and uses as shown in Figures 3 and 6, each typical raised portion 9 is elongate in overall shape having a centre portion 10 and end walls 11 and 12. In use, for example, if a boat is winched over the wheel tread, the boat hull outer surface will contact any two adjacent raised portions 10 and 13 at selected points of contact rather than the complete transverse line of contact which is typical in the conventional ribbed wheel tread. A maximum of three points of contact between any raised portion and a contacting surface, are formed at. Alternatively there may just one point of contact on a raised portion. During one instance of contact, the hull surface lies between two raised portions 10 and 13 with a point of contact will lying at the centre of the length of depression between raised portions 10 and 13 and two outer points of contact at an adjacent raised portion 13 - this being the three point contact point. In summary, during the motion of wheel tread, there are three types of contact points. Firstly, there are a maximum of three points of contact between the contacting surface and the wheel tread for two raised portions (first and second raised portions); secondly followed by two points of contact on one raised portion (spaced apart on the second raised portion) and thirdly followed by one point of contact on one raised portion (in the middle of the second raised portion). In a second instance the contact when the contacting surface of the boat moves from the centre of the length of the depression between adjacent wheel treads, the point of contact can be over the middle of one raised portion having the outer portion of the boat contacting surface lying in mid air over the depression between the adjacent raised portion in the forward direction. Therefore the contact points will shift between the two extremes just mentioned thereby enabling a smooth motion to be produced, such that no noise or clicking or impact is produced during the rotation or movement over the wheel tread and that there is no significant resting inertia to be overcome when the boar surface lies between two raised portions. Significantly during motion of the wheel or motion over the wheel, the contacting surface of the object or ground will always be supported by at least a portion of at least one raised portion. In other variations of the shape of the raised portion, the shape can be "banana" shaped, S shaped, or V shaped or any combination thereof the both maintains contact -8- with a portion of a raised portion at all times of the motion or movement. Another example for a raised portion is spiral shaped or randomly "curling/curving" raised portion running continuously circumferentially around the base of the wheel tread thereby only having one raised portion. Conceivably any of the shapes may be continuously extended around the base. Limitations are normally imposed by economics and the moulding process whereby removal of the moulds will require a specific design to enable a set pattern to be economically produced. The tread can be manufactured from any suitable materials such as plastics or rubber or any combinations therein. The side walls of each raised portion can be angled with respect to the outer contacting surface or it may be curved or whatever facilitates its use and/or manufacturing techniques. Figures 7 and 8 show a variant to the form of wheel shown in Figures 1 through 6. In this form of the invention raised regions 16 are identical throughout the rolling perimeter but are positioned so as to interpose depressions 17 between each which has a similar form to that of each raised region even if not to the same area. There is sufficient depression area 17 such that deformation of the raised regions 16 will mean that on a line such as, for example, B-B transverse to the rolling axis there is a prospect that first a raised region 16A and then its subsequent raised region 16B will simultaneously have regions thereof bearing weight. Likewise 16B to 16BB. If need be the closeness together of the raised regions 16 about the rolling perimeter of the wheel can be closer i.e more nested than as shown. As stated previously preferably the tyre like form shown as a moulding as Figures 7 and 8 is preferably heat moulded about, for example, a wheel or roller hub, rim or the like. A suitable more rigid and less compressible material is used for such a hub or rim (e.g a polypropylene) with which for example a tyre form as shown in Figures 7 and 8 can be moulded (e.g of TPR rubber). The wheel tread has the following advantages: 1. Excellent load carrying capabilities. 2. Reduced noise during use. 3. Adaptable to most trailers. 4. Simple to install/replacement. Durable plastics. Little effort needed to push the wheel. Free rolling wheel. Continuous support/contact of boat hull by the tread. </div>

Claims

<div class="application article clearfix printTableText" id="claims"> -10- WHAT WE CLAIM IS:

1. A non pneumatic treaded wheel, non pneumatic treaded roller or non pneumatic treaded tyre, wherein the treaded area is characterised in that (A) it is of a sequence of raised and depressed forms about the rolling perimeter, each raised form being discrete and extending fully from one side to the other of the treaded area of the wheel, roller or tyre, and (B) where notionally rolling on a flat surface, (i) the transition of surface contact from one raised form of the tread to that raised form immediately following about the rolling perimeter is sufficiently immediate as to be smooth and/or has part of both raised forms making contact, and (ii) at least substantially the full side to side extent of each raised form, but not necessarily simultaneously, will contact such a flat surface during such notional rolling.

2. A wheel, roller or tyre of claim 1 or claim 2 wherein each depressed form at least in area is of a similar shape to the area of its proximate raised forms.

3. A wheel, roller or tyre of claim 1 or 2 wherein the raised form(s) are at least substantially identical and the proximate raised forms mutually nest in part about the rolling perimeter.

4. A wheel, roller or tyre of any one of the preceding claims wherein proximate raised forms present, when viewed in silhouette normal to the axis rotational, substantially straight outline parallel to the actual or notional rotational axis.

5. A wheel, roller or tyre of any one of the preceding claims wherein the tread has been moulded.

6. A wheel, roller or tyre as claimed in any one of the preceding claims wherein at least some of the raised forms when viewed in area towards the actual or notional rotational axis are curved, S shaped, C shaped, spiral shaped or V shaped. -11 -

7. A wheel, roller or tyre as claimed in any one of the preceding claims substantially as hereinbefore described with reference to any one, some or all of the accompanying drawings.

8. A wheel, roller or tyre of any one of the preceding claims which is or is part of a boat roller.

9. A roller of claim 8 wherein a rim of one material has a tread of a different and resiliently deformable material moulded thereon.

10. A boat support or trailer having at least one roller as claimed in claim 8 or 9. INTELLECTUAL PRQPFRTV OFFICE 20 jan 2005 received </div>