Marine propulsion – Oar or paddle – Support
Reexamination Certificate
1999-06-10
2001-02-06
Avila, Stephen (Department: 3617)
Marine propulsion
Oar or paddle
Support
C440S104000, C440S105000
Reexamination Certificate
active
06183325
ABSTRACT:
BACKGROUND—FIELD OF INVENTION
This invention relates to rowing or sculling shell rigging, specifically to an oarlock height adjusting tube that provides for manual adjustment of oarlock height for proper fit of the oar to rower and rowing conditions.
BACKGROUND—DESCRIPTION OF PRIOR ART
Rowing shells, both sweep rowing boats and sculling boats, are moved through the water by oars. The oars transmit power from the rower to move the boat. Both recreational and racing shells are very narrow in beam and it is conventional to mount the oarlocks, which support the oars, outboard of the boat on laterally extending riggers. The comfort, efficiency, and safety of the rower depend upon proper geometry between the rower, boat, and water. This is greatly dependent on oarlock placement. Most rigging adjustments (oarlock span, spread, and pitch) are set and stay constant for all rowers in a particular boat. Oarlock height, however, is very variable, depending on the weight of the rower(s), the height of each rower, and water conditions. Adjusting the oarlock height on most shells is relatively complex, involving the use of tools to partially disassemble the rigging and/or the oarlock/pin assembly to add and remove spacers or to raise or lower the pin. See U.S. Pat. No. 4,411,214 Horiuchi as an example of prior art oarlock adjustment using spacers.
Prior art oarlock height adjustment methods typically have one or more of the following disadvantages.
In prior art practices, it is necessary to adjust the oarlock height before the shell is placed on the water. The position of the pin (out over the water) and the instability of the narrow rowing shell make it very difficult or even impossible for the rower to make adjustments while afloat. If a coach is handy in a launch, the coach can make adjustments, but there is always the risk of damage to the rowing shell as the two boats pitch and roll in close proximity. In addition, dropped tools or parts are usually not recoverable. As a result, this can be a very difficult and time consuming activity.
Currently, most riggers are made of aluminum while the fasteners are made of stainless steel. Repeated disassembly and reassembly cause premature wear on these aluminum components, especially to the topstays, leading to costly replacement.
If a rower has not rowed a particular rowing shell before or has not rowed with the same rowers in the same positions in a familiar rowing shell, oarlock height adjustment most likely will not be accurately predicted, before the shell is in the water with all rowers aboard.
If the same crew of rowers uses the same boat regularly, but share the shell with other crews, they most likely will have to take time to change the oarlock heights before they launch. Crews must also adjust oar height for anticipated weather and water conditions. This results in valuable practice time lost.
Some rowing shells adjust oarlock height by screwing the oarlock pin up or down in the sill after loosening a locknut and the topstay. After oarlock height adjustment, the topstay length must be readjusted for it to fit properly.
A well known shell manufacturer has attempted to solve these problems by using slotted spacers on the oarlock pin, above and below the oarlock. Spacers can be pulled and replaced without the use of tools, but this can be tricky with wet spacers, cold fingers, and choppy water, especially when raising oar height. The spacers sink, so removal and replacement over the water is risky; rowing without spacers is ill-advised.
A recent attempt to solve the problem of oar height adjustment, U.S. Pat. No. 5,873,757 Van Balen, makes use of an internal adjuster in the pin. It can be operated with one hand and has no loose parts. Even solid oarlock pins, however, are notorious for breaking off unexpectedly. Because of the complexity of its design and manufacture, it is difficult to envision a hollow three-part pin that is durable, reliable, and available at a price that would make it attractive.
Objects and Advantages
Accordingly, several objects and advantages of my invention are:
a) oarlock height adjustment using no tools and involving no loose parts; nothing to drop or lose.
b) oarlock height adjustment on or off the water quickly and easily.
c) oarlock height adjustment with no wear on rigger components.
d) oarlock height adjustment without changing other rigger adjustments.
e) an oarlock height adjusting device compatible with the current best-selling oarlock pins and gated oarlocks.
f) an oarlock height adjusting device with fewer parts than any other prior art method.
g) an oarlock height adjusting device of simple, rugged design.
h) an oarlock height adjusting device that is simple and rapid in its operation.
REFERENCES:
patent: 468960 (1892-02-01), Vonersaar
patent: 700827 (1902-05-01), Rollins
patent: 1223512 (1917-04-01), Neville
patent: 4411214 (1983-10-01), Horiuchi
patent: 5873757 (1999-02-01), Van Balen
patent: 5881979 (1999-03-01), Rozier et al.
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