I have read that full automatic pencils are pencils which require no back knocking when the lead piece runs out, in this case how does the pencils feed the new piece once the first runs out? Examples i have seen are the Tk matics, QX PN305 and Pilot e500)
Thanks in advance everyone!
The Faber-Castell TK Matic is not fully automatic, to feed a new lead you have to shake and knock it like any other pencil.
Staedtler Micromatic 777 is full auto, don’t know how it works.
Not only is the 777 fully automatic… there is no manual lead advancement. If it breaks? It’s dead.
would you happen to know how it loads the next lead after the first one gets worn down to a point where it no longer engages the clutch?
Maybe read through one of the patents
US4809023, US4538934, DE3314452, DE3229497
(I took a quick look at DE3314452 i don’t see a push button in the text or images.. seems fitting to me.. but i’m not a knock-pencil guy)
thanks a ton, will do!
@perpetuallypencil, sorry to bother ya again, but could you also enlighten me as to how you have found the patents (I can access them fine but in the future to find patents without your help)?
thanks!
For European, ES use the search bar, very simple. You can toggle advanced search with more of a logical structure too, and further filters for language, timeframe etc. appear after you’ve entered and searched for a search term. If you enter “Staedtler automatic” you can already find the patents I sent. The default search looks for assignors, title, all at once
For US patents, use Patent Public Search | USPTO
Basic search is good when you just want to quickly copy paste a patent number in. For everything else, use the Advanced Search. It has a large number of operators. I’ve just very rudimentarily used it, but as an example
staedtler.as. AND ( automatic AND pencil).ti.
Staedtler as an assignor (=as), and in a bracket the terms “automatic” and “pencil” both to be included in the title (=ti). The dots are part of the syntax
Note that while searching for newer patents is relatively easy, older (-1950) patents are a challenge. Terminology was different, try all kinds of combinations. Or search not for titles, but full text for for example “spring clutch mechanism”. Reading old patents is valuable to extract older or inventor-specific terminology for future searches too. And very old patents are sometimes unnamed, I’ve found many of my pencils by sheer luck this way
The lead basically just falls down the one-way clutch where something like the TK-matic requires a knock to open the end of the one-way clutch allowing a lead to fall through.
Not entirely true - usually you can just pull the piece of lead out the tip and then tap the lead sleeve up and down a few times until a new lead is loaded.
The problem with the 777 “always open” one-way clutch is that it requires tip pressure to activate the one-way clutch, and as widely known, functions very poorly. They actually called it a lead cushioning feature but you just end up with a mushy feeling! 
thanks a ton!