rollator

Yes, I remember the concept, but I didn't know the name, Rollator. Frankly, I didn't know it was ever commercially used, but thought it was only a laboratory concept. I have 'played' with the idea some, but also never utilized it. If you can tell me your application and ideas, without breaching any secrets or other confidential issues, maybe I can also share with you what I am doing and together we can make some progress.

It was called 'rolamite'...

http://www.rexresearch.com/wilkes/1wilkes.htm

A google search brings a plethora of references, some quite recent.

Thanks for the heads-up ... can you believe it is the original PS article I remembered? Strange how age let's you remember something nearly 40 years old, but can't remember what happened yesterday :-/

Thanks again.

Thanks to "Guest" for post #2. I'm glad you realized that I should have said rolamite instead of rollator. We older people can identify with rollators!

I think that rolamites are currently used in some thermostats and pressure gages. Other than that, I don't know of anything else. I've tried over the years to figure out what to do with one, but haven't. I made a model once using 1/2" diameter dowel pins and a piece of shim stock. It was really smooth and could tolerate quite a load.

One of these days I'll use all my accumulated useless knowledge and combine the rolamite with a fluidic device. Thanks for all of the feedback.

I remember the very quiet "Rollator" from the 30's and 40's. This was a vane-type compressor used in Norge domestic refrigerators. It was quieter than the piston-type compressors which were widely used in other refrigeration units. The only reciprocating element was the vane, less massive than a piston and connecting rod for a reciprocating compressor of the same capacity, so it could be made to run more quietly.

Since that time, reciprocating compressors have gotten quieter, and screw compressors and scroll compressors (which have no reciprocating elements) are used where quiet operation is paramount (viz. high-quality room air conditioners). This pump design is actually several hundred years old, having been invented in the sixteenth century. That one probably wasn't used for mechanical refrigeration.

http://kmoddl.library.cornell.edu/model.php?m=38

"Thanks for the heads-up ... can you believe it is the original PS article I remembered?"

Wikipedia references this article:

Norman, Carlisle. "The Amazing Rolamite – It Opens the Door for 1000 Inventions", Popular Mechanics, February 1968.

Was there a Popular Science (PS) article before this, or were you possibly thinking of the PM article instead of PS? Wikipedia references this PM article when it says that, "It is considered the only basic mechanical invention of the 20th century."

[Edit] Ok, I see the Wilkes webpage lists both the PS (1966) and PM (1968) articles.

This leads me to ask another question regarding the "rolamite". Would it be considered a simple machine, like the lever, screw, the inclined plane, the wheel and axle, the wedge, and the pulley, or is it a combination of simple machines or something else entirely?

My son is to do a school science project on a single "simple machine" and it would be so very cool if he had one that was not likely to be chosen by other students. I do not believe that the rolamite is in his textbook, but it could have easily been overlooked.

[Edit] I also see that the PS article calls is an "elementary machine", comparing it to the lever, pulley, etc. but is it really?

"rollator"

Having seen the first light of day in the mid 1920's and the transition from ice box to consumer refrigeration with the "Frigidaire" open, non fan, condensation coil atop the noisy white beast......and seeing Norge domestic refrigerators introduced to the public at the LA county Fair I had great admiration of the "rollator"/rolamite concept.

IT WAS QUIET,,,,,,

I was more used to ammonia as a refrigerant for milk refrigeration on my fathers dairy.

Image a piston type air compressor noise.