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Expanding Roll Core Spindle - What are they called?

RC Mech

Stainless
Joined
Jul 21, 2014
Location
Ontario, Canada
What is the correct name for a mandrel that expands to mount a cardboard roll, such as a label roll, on a winder/unwinder? They look like they're extruded aluminium with a conical core of some type to allow for expansion.

This company calls them "leaf shafts", which doesn't help me. :willy_nilly: The Guru of Motion would likely know but this isn't a shop management query per se.
LeafShaft.jpg
 
We use them on our window machines to hold the window film rolls.Sometimes called an air chuck,air shaft.
Should have an air fitting to expand the bladder inside.
Look at the manufacturers website.
 
Thank you both for your replies. As Ratbldr alluded to, and Guru referenced with the website, they're called "expanding core shafts". Specifically, the one I was looking at is a differential rewinding core shaft (not pictured in the OP).
 
The reason they call them leaf shafts, is because each segment is called a leaf. I've repaired a bunch of Comco and Tidland, but never a Convertech.
 
"Everything you ever wanted to know about TP, but where afraid to ask."...:D

Indeed, many applications but I'm concerned with plastic roll re-winding. Apparently there's quite an art to, what one would assume is the simple operation of, re-winding plastic film onto smaller rolls after slitting. Due to variations in film thickness, each roll must wind at a different torque at different times in the rolling process. This requirement gives rise to a number of convoluted designs for shafting that allow varying speed among multiple rolls on the same shaft, and attenuates the torque of each.
 
Indeed, many applications but I'm concerned with plastic roll re-winding. Apparently there's quite an art to, what one would assume is the simple operation of, re-winding plastic film onto smaller rolls after slitting. Due to variations in film thickness, each roll must wind at a different torque at different times in the rolling process. This requirement gives rise to a number of convoluted designs for shafting that allow varying speed among multiple rolls on the same shaft, and attenuates the torque of each.

Yes, the take up reels on the tape machines (radio station I worked
at) had "Torque motors", but would really like to see how they
accomplish it with multiple reels on one common shaft.
 
This page from the Double E website explains the issue and their solutions quite well:

Double E Home

This is the differential rewinder page, just click "Product Info" next to Summary and scroll down for the "Differential Rewind Problem" explanation.
 
We buy a lot of carbon fiber rolls for paper converting upgrades (mostly bath tissue and kitchen towel lines where we want very light /low inertia rolls for measuring tension) . . . Epoch was our go to supplier and they were purchased by Double E. They are a quality supplier.
 








 
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