Mechanism for automatic release at specified travel
Mechanism for automatic release at specified travel
(OP)
Does anyone know of a mechanism that can release a one-way clutch automatically at a specified travel distance? My need is for a fixed reciprocating motion for both input and output, but the output needs to retract quickly under spring tension at the end of the stroke, independently of the input return stroke. Then the clutch needs to re-engage again when the input completes its return stroke.
A ratchet and pawl probably won't work for me because it's subject to wear and the force on this will be fairly high during the power stroke. I can't risk the tips of the ratchet teeth or pawl breaking under load.
A ratchet and pawl probably won't work for me because it's subject to wear and the force on this will be fairly high during the power stroke. I can't risk the tips of the ratchet teeth or pawl breaking under load.





RE: Mechanism for automatic release at specified travel
Any chance of a sketch of your device, makes it easier for us to see the problem.
desertfox
RE: Mechanism for automatic release at specified travel
If you have air available, then a pneumatic solution is a candidate.
RE: Mechanism for automatic release at specified travel
Attached is a simple graphic of what the mechanism should accomplish. Since we have nothing designed as yet, we don't have any drawings.
RE: Mechanism for automatic release at specified travel
Unfortunately, no outside power source such as pneumatics, hydraulics or electronics will be available for this. It has to be simple, extremely reliable and strictly mechanical. Sorry, I should have specified that.
RE: Mechanism for automatic release at specified travel
theres no image with the link
RE: Mechanism for automatic release at specified travel
It could be done with a cam Circular. but would be a little more a little more complicated.
RE: Mechanism for automatic release at specified travel
http://www.cunningham-ind.com/typical.htm
RE: Mechanism for automatic release at specified travel
I'm thinking cams.
Mike Halloran
Pembroke Pines, FL, USA
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
One thing that comes to mind is a mechanism sort of like a ratchet-n-pawl on the 2nd element that captures the 1st element at the beginning of stroke, then by virtue of a linear cam will release the 1st element at the correct point in downstream stroke.
The other idea was cams & cam followers.
There's a bunch of books out on the market for clever mechanisms...do a search on Amazon for them. That may give you the ideas you need. But ultimately you will have to synthesize the motion requirements and design mechanisms to produce the motion, which is an "old school" machine design task.
TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
www.bluetechnik.com
RE: Mechanism for automatic release at specified travel
Ingenious Mechanisms for Designers and Inventors dates back to 1935, and is no longer under copyright:
Ingenious Mechanisms
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RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
tinktech
A counter weight maybe an option.
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
http://www.youtube.com/watch?v=Dpw_xAvo5kk
http://shopswarf.orconhosting.net.nz/b/shc.html
Here is a very simple mechanism that may do the job.
http://robives.com/blog/quickreturn
I'm try to find a drawing of the mechanism used in high speed perforating machines, essentially he same as sewing machine head.
RE: Mechanism for automatic release at specified travel
Again, thanks to everyone, but we've more or less figured out a mechanism that accomplishes what we need.
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
RE: Mechanism for automatic release at specified travel
Ted