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mechanically operatable shaft mounted coupling for light load; shift at no load

mechanically operatable shaft mounted coupling for light load; shift at no load

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Photo shows a contraption added to a bicycle. What's wrong with the overrunning mechanism that every bicycle already has?

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
THANKS FOR YOUR COMMENT BRIAN, THIS BIKE WAS MODIFIED TO MY PATENT ON DL2R (direct linear to rotary)and it required the disconnect in the drive; what I am looking for is a less expensive disconnect means for my next project, a recumbent three wheeler. Any ideas?
Walt

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Just add another freewheel ratchet between the hub and the pedals. Looks like you will have to modify your modification. . . . good luck.

When it comes to couplings we are always here to help.
WWW.PSCCOUPLINGS.COM

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

What could be less expensive than an old fashioned bicycle coaster-brake that provide torque-forward, coasting/disengagement, and braking functions in a compact space?

Walt

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
Thank you CouplingGuru, The problem is that what I need to stop is similar to the bike crank rotating backwards when moving the bike backwards, so the freewheel would not work; I need to have an actual disconnect like shown on the picture. I would appreciate an inexpensive solution, the one shown is over $300.00!

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Almost nothing is cheaper than sintered iron Lovejoy coupling halves, from which you can make a simple dog clutch.

Mike Halloran
Pembroke Pines, FL, USA

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

"what I need to stop is similar to the bike crank rotating backwards when moving the bike backwards"
That is the exact description of what a freewheel or freehub does.

It looks like you are driving a hub off the pedals of the bike. Your rear wheel has a free wheel in the hub or sprocket, that allows that rear sprocket to sit idle while the rear wheel is moving. You need the same thing on the out side of your pedals before the hub. The only way this won't work is if you are trying to drive torque in both directions. (forward and reverse)

When it comes to couplings we are always here to help.
WWW.PSCCOUPLINGS.COM

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
When one pushes a bike backwards that action will LOCK the freewheel and rotate the crank backwards!

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Yes, it's counterintuitive, but the freewheel doesn't know or care which way the rear wheel is actually spinning. It's only purpose is to prevent relative motion between the sprocket and the wheel, in one direction.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
That is correct and why I need an actual operable disconnect.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

There are lots of small dog clutches used, like in small outboard boat motors.
I'll bet that you can find one with the actuation fork ready made.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
Thanks for the tip, I will look at outboard boat motors clutches and see if that will work!

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Nescius,

I am mildly confused by your statement, the purpose of a freewheel is to ALLOW for relative motion in one direction, not prevent it. Otherwise you would just use a rigid coupler. Maybe just semantics, but there are a lot of ways to prevent relative motion.

WALT1A,

based on the fact you don't want the action to lock when the bike is pushed backwards, orient the freewheel so that direction is not impeded. Seems to me you have a one directional torque application, since you don't want torque transmitted in the backwards direction of rotation.

When it comes to couplings we are always here to help.
WWW.PSCCOUPLINGS.COM

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

CouplingGuru,

Allowing relative motion in one (and only one) direction is the same as preventing it in one (and only one) direction. Philosophically, is a freewheel the thing that lets you coast...or is it the thing that lets you go? You imply that a freewheel replaces a rigid coupling to enable coasting. I counter that the freewheel replaces NO coupling to enable going.lol

If you have a bike with a freewheel, go push it backwards. The crank will turn backwards, too. Perhaps you do not doubt this.

Any input to either the wheel or the crank that tends to tension the top span of the chain will give a rigid connection, no freewheeling. It must be. Putting any freewheel into the system that prevents tensioning that top span, well, prevents tension in the top span. Of course, no tension there means no ability to go. As I said above, the freewheel has no notion of which direction the chain is moving. There's no such thing as backwards or forwards.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

Coupling Guru - someone is just playing with words.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
OK,my design incorporates two one-way clutches driven in straight line by the pedals therefore any reverse force would result in the lockup of the clutches, ergo the need for the de-clutcher if the unit is pushed backwards.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
Thank you for the information STRONG, No, I did not see that one; my design is based upon my patent NO US 8,215,645 B1 issued 7/10/2012 for mobile devices. See attached, and an inexpensive de-clutcher system is required for my design.

RE: mechanically operatable shaft mounted coupling for light load; shift at no load

(OP)
3D DAVE, sorry, I transported ;the patent number it is US8,215,654 B1 ;THAT SHOULD WORK!

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