Friction Tension- What controls it?

[Jerry Alexander]

October 4, 2016:

 

I continue to have problems climbing inclines with my 1915 Model 22. About 3 to 4 years ago I took the pulley to the Paper Pulley Company in Columbia, TN and had the pulley rebuilt. Hoping that solved the problem but it did not. Then I was informed in this forum what the proper distance needed to be between the friction wheel and the pulley (a hack saw blade width distance) and that really helped! But it has not cured the problem. I can crawl most inclines IF I have a running start. If I get stopped on an incline which happens in parades quite regularly, I am stuck until some kind soul gives me a push.  There is the same problem if I park in grass too.

 

This morning I discussed my problem with a representative of the Paper Pulley Company. After a lengthy discussion he suggested that there may not be enough pressure on the pulley.  He most likely is correct. But how do I gain pressure on the pulley. Is it the strength of the spring on the pedal that does this or is there some place else that controls the pressure.  If indeed it is the spring(s) does anyone know where new springs of sufficient strength can be purchased? Or is there another possible solution? 

 

Any advice/guidance will be appreciated.

 

Thanks,

 

Jerry

[Luv2Wrench]

While I don't have my car functional at this point, this is how I understand the system to work.

 

The friction wheel pedal is attached by long arms to and rotates about a shaft that runs perpendicular to the frame rails.  As you press down (forward) on the pedal this causes a force backwards (toward the rear).  This force is transferred to the 'propeller shaft clutch bracket' (circled in green in the attached pic) via a rod (with a spring) that connects at '32' in the pic (red arrow showing force).  This pushes the friction disc against the pulley.  When you release the pedal the friction disc is pulled back away from the pulley by the clever manner in which the propeller shaft is attached to the flywheel.  If you look (right side of pic and circled in red), you'll notice that the end of the propeller shaft is a square and that it has thin strips (2460i in the picture) that attach to the flywheel.  These strips are spring steel and pull the shaft back towards the engine and away from the pulley.  As such, when you press down on the pedal you are overcoming these forces as well as trying to firmly connect the disc and pulley.  The rod that connects at '32' has a long spring wrapped around it.  The rod is also threaded and has two nuts that control where the spring 'stops' on the rod.  The spring is there to dampen the force.  Said another way, when you apply a force to the rod it is the compression of the spring that transfers the force to the clutch bracket (and thus friction disc).   As you thread the nuts down the shaft it makes the spring shorter and more compressed.  This increases the force delivered.  You might need to replace the spring or possibly just adjust the nuts such the the spring is shorter in length.  

 

(edit)  I added two more pictures to show the connection of the rod and the spring.  The first picture shows the two nuts toward the front of the rod.  These adjust where the spring stops and adjust the length of the spring (and thus firmness).  The second picture shows how the rod goes through the 'eye' connector on the bracket.  Notice that it is the spring that is really transferring the force.  Note also the two nuts on this end.  These are used to adjust the overall length. 

 

I hope this helps though it may not be clear enough.  Shoot me an email if you need more information. 

 

 

Edited November 9, 2016 by Luv2Wrench (see edit history)

[Jerry Alexander]

December 9, 2016: THANK YOU!!!  I believe I have, in the past, made the adjust you suggest. After reading your assistance suggestion I will insure that I have compress the spring. If it I find that I have compressed the spring to the point it can no longer be more compressed I will look at replacing the spring. I would guess that after 100 years of use, going on 101, it may be showing it's age a bit.

 

I have also been advised that I can add some material, a canvas/rubber conveyor belt around the paper pulley to gain traction. While I have located such material I have yet to figure out how to attach the belt without destroying the integrity of the pulley. I hesitate to use metal clips or glue to attach the belt.  I will leave the belt option as a last alternative and try to remain more 'pure' in the quest to improve traction between the pulley and the friction plate.

 

I do thank all for your assistance and counsel in this matter.

 

Since I live in Western Illinois and it is December, my Metz is at rest in a garage for the winter. I look forward to exercising her come spring though.

 

Jerry