A WHEEL |
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申请号 | EP04740296.1 | 申请日 | 2004-06-23 | 公开(公告)号 | EP1641636B1 | 公开(公告)日 | 2011-09-28 |
申请人 | Thompson, Roger; | 发明人 | Thompson, Roger; | ||||
摘要 | A wheel (10) comprising means for providing one or more protrusions in a ground-engaging surface of the wheel. In some embodiments, the wheel comprises a first hub (18), a tire (12) mounted on the first hub (18), a second hub (20) rotatable with respect to the first hub (18), and means for deforming the tire in a generally radial direction in response to relative rotation between the first (18) and second hubs (20). The invention also provides a wheel cover (110) comprising an outer surface having one or more protrusions and, when the cover is fitted to a wheel, the outer surface of the cover (110) provides the ground-engaging surface (114) of the wheel. The wheel (10) and wheel cover (110) of the invention are particularly suited for use with prams and similar vehicles in order to impart a rocking motion to the pram during use. | ||||||
权利要求 | |||||||
说明书全文 | The present invention is concerned with a wheel, in particular a wheel for a child's carriage, pram, buggy or other vehicle. It is well established that infants and toddlers enjoy some form of rocking motion in order to help them relax and/or to encourage sleep. In addition, rocking motion can be beneficial in releasing trapped wind, further comforting the child. It is known to provide coil springs, or the like, disposed between the body of a pram and the undercarriage thereof in order that a person pushing the pram may impart a rocking motion to the pram. However, it is necessary to effect this rocking motion manually. It would be desirable, therefore, to provide means for imparting a rocking motion to a pram, or other vehicle, which does not require significant effort by the person pushing the pram. United States Patent Accordingly, the invention provides a wheel as claimed in claim 1. It is particularly preferred to employ a wheel embodying the invention at only one side of the vehicle so that a side-to-side rocking motion is imparted to the vehicle's occupant. According to the invention, the wheel comprises a first hub, a tyre mounted on the first hub, and means for deforming the tyre in a generally radial direction. The wheel comprises a second hub rotatable with respect to the first hub, the tyre deforming means being responsive to relative rotation between the first and second hubs to deform said tyre. Also according to the invention, the tyre deforming means comprises one or more cams and one or more corresponding cam followers, the or each cam being engagable with a respective cam follower to effect a localised deformation of the tyre. The or each cam is provided on the second hub and the or each respective cam follower is provided on an inner surface of the tyre. The arrangement is such that relative rotational movement of the first and second hubs causes the or each cam to engage with the or each respective cam follower. The or each cam comprises a roller, rotatably mounted on the second hub. The or each cam follower may comprise a generally convex projection formed on the inner surface of the tyre. In preferred embodiments, when the wheel adopts a rocking state, two protrusions are provided in the ground-engaging surface, the two protrusions being generally oppositely disposed on the wheel. Further advantageous aspects of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments and with reference to the accompanying drawings. Specific embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:
Referring now to The wheel 10 comprises a tyre 12 having an outer, or driving, surface 14 (the driving surface 14 being the surface that engages with the ground when the wheel 10 is in use) and an inner surface or wall 16. The tyre 12 is mounted on a hub 18 such that the inner wall 16 engages with an outer surface of the hub 18. The tyre 12 is formed from a resiliently deformable material, preferably a rubber or the like, in order to provide both shock absorption and grip. The use of a resiliently deformable material for the tyre 12 is advantageous for the purposes of this aspect of the invention, as will become apparent from the following description. The tyre 12 is seated on the hub in any convenient manner. In the preferred embodiment, the tyre 12 is seated on the hub 18 with an interference fit in order that the tyre 12 is retained, in use, thereon. A retainer (not shown), such as a rim or the like, may be provided on the hub 18 to further secure the tyre 12 in place. The hub 18 itself is rotatably mounted on an inner hub 20, which is in turn mountable, substantially at its midpoint 30, to an axle (not shown) of the carriage (not shown) in any convenient conventional manner. The arrangement is such that, in use, the wheel 10 is rotatable about an axis defined by the axle, and the inner and outer hubs 20, 18 are rotatable relative to one another about said axis. The wheel 10 is also provided with means for deforming the tyre 12 in the form of a pair of actuators 22, both of which operate identically to one another, and it is therefore sufficient to describe the configuration and operation of a single actuator 22. It will however be apparent from the following description that additional actuators 22 could be provided on the wheel 10, or indeed the wheel 10 could be provided with only a single actuator 22. Each actuator 22 comprises a contact 24 disposed between the hub 18 and the inner wall 16 of the tyre 12. Thus, in the embodiment illustrated, there are a pair of generally diametrically opposed contacts 24. Mounted between each contact 24 and the inner hub 20 is a connecting rod 26, which also forms part of the actuator 22, which connecting rod 26 is pivotally mounted at respective ends thereof to the contact 24 and the inner hub 20. The wheel 10 is also provided with a handle 28, conveniently mounted on the inner hub 20, which enables the inner hub 20 to be rotated relative to the hub 18 about the wheel's axis of rotation. In use, the wheel 10 may adopt a non-rocking state (as depicted in The wheel 10 is operable to adopt a rocking state (not illustrated) as is now described. With the contact 24 in the retracted position, the inner hub 20 may be rotated, via the handle 28, (clockwise as shown in The resilience of the tyre 12 tends to have the effect of urging the contact 24 back into the retracted position. For this reason, the wheel 10 is preferably provided with an abutment 32 associated with each actuator 22, which is adapted to secure the contact 24 in the extended position. The abutment 32 is secured to the hub 18, but projects radially inward beyond the interface between the hub 18 and the inner hub 20. Thus, as the inner hub 20 is rotated, the contact 24 will reach its maximum outward displacement after approximately one quarter of a revolution of the inner hub 20. The inner hub 20 is then rotated just beyond this point, whereby the end of the connecting rod 26 comes into contact with the respective abutment 32, and cannot therefore be turned any further. Thus, although the tyre 12 will be urging the contact 24 back into the retracted position, the abutment 32 will prevent this from occurring, therefore securing the contact 24 in its extended position. In order to return the contact 24 to the retracted position, it is simply necessary to rotate the inner hub 20, via the handle 28, back to the position shown in It will be understood that any other suitable equivalent could be used in place of the actuator 22, while maintaining the general functionality of the wheel 10. For example, a simple rack and pinion (not shown) could be used, or a conventional worm/screw arrangement (not shown). Referring now to In order to enable the cover 110 to be fitted, it is preferably formed from a resiliently deformable material, preferably rubber, such that the cover 110 may be stretched over the existing wheel (not shown), and will then return to its original shape in order to effect a grip on the existing wheel. The cover 110, and in particular the wheel-receiving channel that it defines, is therefore preferably slightly smaller in dimension than the existing wheel to which it is to be fitted. In preferred embodiments, the cover 110 is formed from a resilient elastic material so that it may be fitted to wheels of various sizes. In addition, the cover 110 is advantageously provided with at least one and preferably two recesses 46 in the front wall 42 which open onto the inner area defined by the cover 110. The recesses 46, which are preferably generally oppositely disposed on the cover 110, facilitate the further deformation/bending of the cover 110 to allow same to be fitted to a wheel. Similar recesses 46' may be provided in the rear wall 44, preferably substantially in register with the recesses 46. The cover 110 is also preferably provided with at least one and preferably two apertures 48 which are dimensioned to allow a person's fingers to be inserted therein, in order to provide points at which the cover 110 may be firmly gripped, and therefore stretched, for fitting to a wheel. The apertures 48 are preferably generally diametrically oppositely disposed on the cover 110 and may be provided in the front wall 42 and/or in the rear wall 42. It will be appreciated that the cover 110 may be quickly and easily fitted or removed as required, and does not have to be permanently secured to the existing wheel (not shown). It will also be appreciated that as the cover 110 is conveniently formed as a single piece, with no moving parts, it may be inexpensively manufactured, is simple to operate, and requires no maintenance. Referring now to The wheel 210 comprises a second hub 220 which is rotatable with respect to the first hub 218 about said axis. To this end, the second hub 220 may be directly or indirectly mounted on the axle. In the preferred embodiment. the first and second hubs 218, 220 are located adjacent one another in the axial direction. The wheel 210 further comprises a lever or handle 228 coupled to the second hub 220 for effecting relative rotational movement between the first and second hubs 218, 220. The wheel 210 further includes means for deforming the tyre 212 upon relative rotational movement between the first and second hubs 218, 220. In the preferred embodiment, the tyre deforming means comprises one or more cams 240, or equivalent device, provided on the second hub 218, and one or more cam followers 242, or equivalent device, provided on the inner surface of the tyre 212, the arrangement being such that, upon relative rotational movement between the first and second hubs 218, 220, the or each cam 240 engages with a corresponding cam follower 242 resulting in a respective localised deformation of the tyre 212 in a generally outwards, or radial, direction. In the embodiment illustrated in The, or each, cam follower 242 preferably takes the form of a respective projection or cam surface provided on the inner surface of the tyre 212, and therefore facing the second hub 220. As may best be seen from The wheel 210 is operable between a non-rocking state (depicted in The wheels 10, 210 or cover 110 may replace, or be fitted to, one or more conventional wheels of a given vehicle (not shown). In a preferred mode of use, however, only one wheel 10, 210 or over 110 is used at only one side of the vehicle (not shown), the remaining wheels of the vehicle being conventional. For example, for a pram or buggy having one or more wheels at opposite sides, the wheel 10, 210 or cover 110 may replace or be fitted over only one of the side wheels, preferably a rear side wheel or a non-steerable wheel. As a result, the vehicle is not only rocked up and down as it is pushed along, but also in a side-to-side manner (with respect to the general direction of movement of the vehicle). Hence a gentle sideways rocking motion is imparted to the vehicle's occupant. This is found to be particularly effective in lulling an infant to sleep. The present invention is not limited to the embodiments described herein, which may be amended or modified without departing from the scope of the present invention as defined in the appended set of claims. |