Off-The-Shelf Positive Stop Mechanism For Spool Shaft

Is there anything on a sewing machine mechanism that could be developed?

McMaster Carr has these which go down to a 1/4 "

Slide on in one direction lock in the other. Pull on ring to unlock

AWESOME!

I will see if I can make this work. Thank You very much for your input.

Please be a little more specific for those of us unfamiliar with "wire bobbins" and "spool shafts".

Is the shaft straight or does it taper?

How long is it?

Doe the bobbin revolve, or is it stationary?

Are all bobbins the same size for a given shaft?

How much extra shaft length remains outside the bobbin when the largest bobbin is used?

Are you looking for something to modify the shaft, the bobbin, or add as an independent and removable device to the shaft/bobbin assembly?

Can the bobbins be modified to lock onto a device incorporated into the shaft or vice versa?

Carr Lane Manufacturing has a number of spring-loaded devices that might work in your application.

Hello,

The shaft for the spool (bobbin) is constant dia. The shaft is 18" in length. The spools are all the same size but have different weights. (8 lbs. min-55 lbs max.) The spools are approx. 371.8 mm in length and 405 mm in dia @ the flange. There is approx 52 mm of shaft left when bobbin is on shaft.The spacing between the shafts to centre-to-centre is supposed to be approx.16-1/2". The spools are to remain stationary with repect to the shaft axis. The locking must be positive!!! i.e. nothing can be removed and forgot about and not replaced and have an unsecured wire bobbin. I'm thinking putting something on the shaft itself to secure the bobbins can't work. I think the only sloution is to do something independent of the shaft and the bobbin can't be modified. I have developed a torsion spring loaded swinging handle that can be moved out of the way to remove bobbins and springs back in place to lock bobbin. But, this requires much space!!! space I don't have. These bobbins go on an 18 ft carrier that rotates on a vertical carousel and the carriers come into close proximity when the carousels rotates. Let me know if you come up with any ideas.

Thanks,

What is the fit between bobbin ID and shaft OD? Give exact dimensions if possible.

Also, what is the orientation of the shaft axis (horizontal, vertical-top load, vertical-bottom load, angle up, angle down, etc.)

What is the material of the shaft and bobbin? Are the diameters constant from flange to flange, or is the bobbin hollow and only close to the shaft at the flanges? If so, how thick are the flanges?

How many of these do you need?

Hello,

The shaft fit is close. There's approx. 4.3 mm diff. in dia. Saft OD is 22.225 mm and bobbin ID is 26.5 mm. Shaft orientation is horizontal. Shaft material is hot rolled steel pipe (DOM) 7/8" OD x 100wall or 1/8 wall. Bobbin does not have constant dia. (they hollow out) and flange is approx 5 mm thick. Bobbins are composite with steel inserts at the arbor hole. I need 210 shafts for 210 bobbins.

Thanks,

If you haven't visited the Fenner Drives website, I forgot to mention to you that the Trantorque device tightens down on a shaft as well as expands inside a hub, if that helps.

Without waiting for your answer to my other questions I will propose this possible solution, which may not work if it doesn't fit your application:

If your bobbins have a constant ID from flange to flange (including very little or NO lead-in chamfer), and if the difference between the shaft diameter and the bobbin ID is less than 1/4 inch, and if your loader is allowed to use a flat end stick, rod, or other tool, or has really tough thumbs (to push against up to 20 pounds spring force on a 1/4 inch diameter ball nose), then a spring plunger might work.

Carr Lane Mfg. sells a 3/4 inch long spring plunger with 1/4 inch plunger travel (1 inch overall length extended). Installation would be easy. Simply drill and tap a cross hole for 1/2-13 thread through the center of the shaft at the top/outside of the spool flange when it is loaded. Screw in the spring plunger so the backend does not stick out and so you get maximum extension of the plunger, but clearance when it is retracted (pushed in).

Operation is also easy. To load a spool, depress the plunger (suggest using stick/rod/tool, etc.) and load the spool. Plunger will slide along ID of spool and pop back out at top of flange, retaining spool until depressed again. To remove spool simply depress plunger and lift off spool.

Part No. CL-75-SPS-1 is $4.10 each (10% discount for 20 or more) in plain steel (black oxide finish) or CL-75-SSPS is $6.90 in Stainless Steel. Smaller sizes are also available.

I have other ideas that might work for you once I know the answers to my other questions. Give me your comments on this solution to help me if it is not feasible for you.

Hello,

If I use a sleeve to go over the plunger and shaft i.e. to make the bobbin have constant hole diamter, this could work. But, I would have to make or buy a tool to depress the ball plunger and then remove the sleeve to lock the bobbin. The customer may not want to have to do this, but it would work. It is certainly a cost effective solution. However, I have figured out a way to reduce the profile of my torsion spring swinging handle which uses a locking latch. I use these all the time for wire dispensing machines. I will model both solutions and consult the customer and let them decide which one is best for them. The carrier is a different story!!! the customer has loading/unloading specs that are wild!!! To find a cheap way of making it with minimal deflection and ease of manufacture will be a challenge. Pro/Mechanica to the rescue!!!

Thanks for all your ideas.

WOW!!! your resume is impressive.

I hope to make money like that someday.

**********Later,