How not to remove a Vacumatic Pellet

[Richard]

I disagree. I refer you to US patent 1,985,643...

Disagree if you like. That patent refers to the Lockdown filler, which must be assembled as your image describes. But the hole in the Lockdown's (and the Speedline's) plunger is larger than the finished size of the hole in the plastic plunger; the difference is in some cases quite dramatic. I have had plastic plungers whose holes were small enough that I could not, using any amount of force of which I was capable, insert the pellet without shearing off the end of the diaphragm against the edge of the pellet pocket. I've examined bunches of plastic pellet pockets very closely, and I remain certain that these units could not have been assembled as the patent describes.

[Radman]

Thats just so incredibly awesome!  I WANT ONE!!!

 

You da' MAN my friend!

 

Dennis

Me too!

That has to be one of the more thought out and useful tools I've seen in quite some time.

 

If you ever decide to make a few more, keep us in mind...

[danielfalgerho]

I still think an exchange of views and raising of questions is a good thing, especially in forum.

I just found out my reasoning on the pellet size versus cup size was wrong and never would have found out if I hadn't raised the question.

I raised the question because the idea of a Dremel tool bit in close proximity to a pellet cup sounded a bit scary at first.

Anyone who wants to sit in silence and listen to the professor is free to do so and the professor is free to ignore questions if they are stupid.

Many thanks to Richard for clearing up an important point.

[kirchh]

I disagree. I refer you to US patent 1,985,643...

Disagree if you like. That patent refers to the Lockdown filler, which must be assembled as your image describes. But the hole in the Lockdown's (and the Speedline's) plunger is larger than the finished size of the hole in the plastic plunger; the difference is in some cases quite dramatic. I have had plastic plungers whose holes were small enough that I could not, using any amount of force of which I was capable, insert the pellet without shearing off the end of the diaphragm against the edge of the pellet pocket. I've examined bunches of plastic pellet pockets very closely, and I remain certain that these units could not have been assembled as the patent describes.

I agree that it is possible that the plastic pellet pocket was factory-swaged around the pellet [edit: and I agree that the patent to which I referred describes the metal plunger design, not the plastic]. However, I will make a few observations:

 

- The plastic pellet pockets may have shrunk since their manufacture.

 

- Do we know whether the size of the pellet used for plastic units was the same as that used for Lockdown or Speedline units?

 

- There seems to be no disagreement that when things are sized accordingly, a diaphragm can be securely and almost instantly attached to the plunger with a snap-fit. I wonder why Parker would have changed from such a successful arrangement to one that would require an additional operation that would involve presumably heating and spinning a filler unit with the tip of a diaphragm inserted into the pocket (perhaps a snap-fit would not have provided enough strength with the plastic construction)? Given that Parker was aware that diaphragms would fail, presumably they would not have expected repairers to be able to remove the old pellet and install a new diaphragm (though I do know that some later repair manuals imply that filler units were supplied complete with diaphragms).

 

--Daniel

Edited February 1, 2007 by kirchh

[Johnny Appleseed]

Daniel,

 

I think there is an important distinction between the theoretical manufacturing process described in a patent and the actual manufacturing process used on the factory floor. Parker may have patented a process for the manufacture their pellets, then switched to a slightly different method because the different method worked better/was cheaper/etc. The slightly different method may have not been worth the trouble of patenting it, or might not be different enough from other methods to be patentable.

 

Lacking the archival records on the manufacturing process, we need to look at the actual product and other evidence to see how closely it appears the manufactured process follows the patent (which is what the subsequent points do, and which I am not qualified to offer an opinion on).

 

Did Parker ever do an updated patent for the plastic plunger? Is that what US2406330 does?

 

John

[kirchh]

I think there is an important distinction between the theoretical manufacturing process described in a patent and the actual manufacturing process used on the factory floor. Parker may have patented a process for the manufacture their pellets, then switched to a slightly different method because the different method  worked better/was cheaper/etc. The slightly different method may have not been worth the trouble of patenting it, or might not be different enough from other methods to be patentable.

 

Lacking the archival records on the manufacturing process, we need to look at the actual product and other evidence to see how closely it appears the manufactured process follows the patent (which is what the subsequent points do, and which I am not qualified to offer an opinion on).

Your points are excellent and I agree completely. I am open-minded on this issue; I would like to see more data. There may also be Parker materials that discuss filler servicing that make it clear that the diaphragm is not field-serviceable (if so, did Parker have to re-manufacture filler units with failed diaphragms?).

 

Did Parker ever do an updated patent for the plastic plunger? Is that what US2406330 does?

 

The patent shown is for a design (or, more accurately, two designs) for securing the center of the diaphragm that I have never seen an example of; neither corresponds to the plastic pellet pocket design. However, that patent, along with such patents as the much earlier 2031343 for a variation on the Vac system, do show that Parker continued to tinker with the method of attaching the center of the diaphragm.

 

--Daniel

[danielfalgerho]

It looks like we need to track down some former Parker employees.

Does anyone have any leads?

<_<

[Vintagepens]

As I recall, the later plastic-plunger Vac filler units were considered disposable. That would make sense, as the cost for the units would have been low indeed. Keep in mind, too, that when one studies old-time factory repair manuals, it is quite striking how everything revolves around speed. When a new filler unit, complete with diaphragm, cost only pennies, there was little incentive to go through all the hassle we do to fish out the pellet, size the hole, mount the new diaphragm, trim it, dust it with talc, evert it, and then glue its skirt down, before reinstalling.

 

I've had quantities of new old stock factory replacement filler units, complete with diaphragms pre-installed. With these, one could service Vacs and 51s in minutes, while a customer waited.

[Dillo]

Hi,

 

The way I remove the pellet is either to drill it out using the smallest drill bit in the Dremel drill bit set or to remove it with a Dremel burr. The Dremel is attached to a flex shaft and the handpiece of the flexshaft is fixed into a vise. All I have to do them is control where the filling unit is going. I can rest the side of my hand on the table and this leads to a great amount of stability.

 

Still, Daniel's contraption is an ingenious one, and maybe someday, I'll get one I can, of course, vouch for Daniel's work. It is extremely high quality.

 

Dillon