The present invention relates to a sleeve arrangement for an oar and has application to oars that may be used in competitive and/or non-competitive rowing.
Oars such as those used in competitive rowing are sold with sleeves. The sleeves are fixedly bonded to the oar shaft at the factory and sold together with the oars.
Occasionally, a rower may wish to change the sleeve on an oar. The sleeve may have become worn and require replacement, or the rower may wish to change to another type of sleeve, for example to use the oar in conjunction with a different type of swivel. Specialised equipment is needed to perform the change and, to the best of the inventor's knowledge, currently the sleeve can only be changed by returning the oar to its manufacturer or a specialised technician. This is an expensive and time consuming process. It will be appreciated that at a rowing meeting there will often be comparatively scarce time between a participant's competitive events. Hence, achieving a change of sleeve in the short period of time available may be difficult or impossible using the prior art oars and the associated techniques.
In a first aspect the present invention provides a sleeve arrangement for an oar including:
an inner sheath which is adapted to be affixed to the shaft of the oar;
a sleeve which is made up of at least two sleeve members adapted to be fitted around the inner sheath; and
a releasable sleeve fastening arrangement adapted to hold the sleeve members in place relative to the inner sheath.
The at least two sleeve members may be held together by the sleeve fastening arrangement, which may include a number of threaded fasteners.
The inner sheath may be adapted to be permanently affixed to the shaft of an oar.
The inner sheath may be made up of at least two sheath members.
The at least two sheath members may be held together by a sheath fastening arrangement.
The sheath fastening arrangement may include a snap fit between a series of clips and lugs.
The sheath fastening arrangement may include a number of threaded fasteners.
The sleeve may be formed of a softer material than the inner sheath.
The sleeve arrangement may further include a collar adapted to be mounted to the sleeve.
The collar may be made up of two collar members.
The collar members may be held together by a collar fastening arrangement.
Preferably the collar fastening arrangement includes a number of threaded fasteners.
An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Referring to
The outer profile of the sleeve is shaped to be a good fit with a popular type of oarlock used in competition rowing known as the “MK1” and sold under the brand Magik Rowing™. However, the outer profile of the sleeve is believed to also be compatible with various other commercially available oarlocks.
Now with reference to
The first and second sleeve shells 14, 16 are then placed about the inner sheath 17 and brought together. The outer profile of the inner sheath 17 is dimensioned to be a snug fit with the inner profile of the sleeve 13. A series of projections 32 provided on the first sleeve shell 14 locate in slots 34 provided on the second sleeve shell 16, but do not engage with a snap fit. A number of threaded fasteners in the form of nuts and bolts are then threaded through corresponding holes 36, 38 provided in the first and second sleeve shells 14, 16 and are tightened appropriately.
Collar 21 is now fitted to the sleeve 13 by placing the first and second collar shells 22, 24 about the sleeve 13 and passing threaded fasteners in the form of nuts and bolts through corresponding holes 23, 25 in the collar shells. Only one pair of holes 23, 25 is visible in
The collar 21 provides a degree of adjustment of the inboard dimension of the oar, that is, the distance between the oarlock, and the inboard end of the oar. This distance can be adjusted to allow for differences in the dimensions of different boats, or to suit the preference of a particular rower. Upper and lower collar shells 22, 24 include internal projections (see for instance reference numeral 40 in
Should a user wish to change the sleeve due to it becoming worn, or perhaps to change to a different style of sleeve, then it can be replaced by the user using common hand tools. The collar is removed by releasing its fasteners. Then the fasteners holding the sleeve shells 18, 20 are removed. The sleeve shells 18, 20 may then be removed from the sheath 17 and be replaced by the new sleeve shells. The fasteners and collar are then reattached and the oar is again ready for use. It is not necessary to send the oar away to a technician to perform the change. Additionally, the time taken to change the sleeve is typically significantly shorter as compared to the period of time required for the known prior art methods. Additionally, the embodiment of the invention allows for more cost efficient replacement of the sleeve as compared to the known prior art methods.
The sheath shells 18, 20 are formed from a rigid material, for example carbon fibre or a plastics material such as a nylon/glass composite, so as to promote a long service life. The sleeve shells 14, 16 are formed from a self-lubricating plastics material to help reduce the friction and noise experienced during use. In one embodiment the sleeve shells 14, 16, are constructed from a non-glass filled nylon. In other embodiments the sheath shells 18, 20 and/or the sleeve shells 14, 16 may be constructed from one or more polyolefins including polyethylene, high density polyethylene and polypropylene. In some embodiments the sleeve shells 14, 16 are formed from a softer material than the sheath shells 18, 20 so as to promote wear of the sleeve shells 14, 16 in preference to wear of the sheath shells 18, 20. The sleeve shells are intended to be a sacrificial component and will wear out over time. Indeed, the relative ease of replacement of the sleeve means that less importance may be placed upon the sleeve's long-term wear characteristics, which allows for a greater range of choice of materials from which to construct the sleeve.
The embodiment described above makes use of fasteners in the form of nut and bolt combinations and/or self-taping screws. However, in alternative contemplated embodiments other forms of releasable fasteners may be utilised to affix the inner sheath shells 18 and 20 about the shaft 12, to affix the first and second sleeve shells 14, 16 to the inner sheath and to affix the upper and lower collar shells 22, 24 to the sleeve. Non-limiting examples of alternative releasable fasteners include clips, rivets that can be easily removed with a drill or similar tool, Duz fasteners and/or press studs.
In an alternative embodiment, the outer profile of the sheath 17 is integrally formed from carbon fibre with the shaft of the oar at the time of manufacture. In this embodiment, it is not necessary to fasten separate sheath shells to the oar shaft.
Any reference to prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise indicated.
Finally, it is to be appreciated that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the present invention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AU2008/000092 | 1/30/2008 | WO | 00 | 11/2/2010 |