Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
What it does
Design of novel ski rope management systemPHY435 – Theme 2- Product invention
Dan Friend, Department of Physics and AstronomyUniversity of Sheffie ld
The ski rope management system is a tension controlled winch that is to be fitted towards the rear of a boat and providethe connection between the boat and the rope. Its purpose is to decrease the number of rope inflicted injuries sustained
by water-skiers and also make the sport easier to learn.
Safety
• Water skiing is growing sport with approximately 17million people taking part each year in the USA.
• In 2003 the US Coastguard reported that water skiingwas responsible for 700 serious accidents and 19deaths.
• Many of these accidents were caused by water skiersbeing dragged under water as they became entangled inthe trailing ski rope whilst being retrieved by the boat.
Why is this product needed? Aided learning• Water skiing is a difficult sport for beginners. Being able
to simply get out of the water generally takes several hoursof practice.
• Once out of the water staying up isn’t easy. The key tosuccess is balancing the force from the boat with thefriction between the water and the skis, in order to maintainconstant speed.
• If at any point the skier goes faster than the boat (eg whenthe boat accelerates in to the trough of a wave), the ropegoes slack, leaving the skier with nothing to pull againstresulting in them falling off backwards.
How it Works
• The ski rope management system is controlled by a tension switch that triggers a winch to wind in the rope.
• If the water skier falls off, the decreased tension will cause the rope to be safely retracted back to the boat.
• Once the rope is aboard the boat it is unable to injure the skier or other people.
• When the rope goes slack it is quickly recoiled until the the tension in the rope reaches a level suitable for water-skiing.
• This gives novice skiers a greater success rate.
CoverPlastic cover fits over the mechanicalsystem to protect components andalso keep people away from movingparts.
WinchGeared winch to rapidly recoil rope whenturned on and slowly release rope whenturned off.
Selling points and market• This product is unique………….No competition!
• Reduces risk of accident.
• Increases rate of learning.
• East to fit to the boat.
• Large market – Tens of millions of waterskiers 100,000 + boats
Cost• Approximate cost - £500.
• Typical water skiing prices-
Ski Boat £20,000 +Water ski - £500Ski rope - £75Life jacket - £100
Limitations andfuture development
• Components may become damaged/worn.
• Only designed for boats with a ski pole.
• Make universal system in future.
• Add extra features such as skier position detector.
Tension controlled switchAs the rope goes slack the spring expandstriggering a micro switch that controls thewinch.
Micro switch
Connection to winch mountings
Spring
Attachment bracketBracket is compressed around the ski pole.
Bolt
Stainless steel bracket
Fixed steel casing
Welded mountings
Eclectic motor
Spool
Wheels and runnersAllows winch to move as tension inrope changes.
Fixed casing
Sliding casing Wheel300mm
350mm
200mm