Q: Was a pencil sharpener patented by Walter K? ¶
A: Yes, Foster of Bangor, Maine in 1855.
Q: Are pencil sharpeners able to sense when the tip of the pencil is long enough and then stop? ¶
Q: Are pencil sharpeners powered by batteries rather than being plugged into a building's electrical system? ¶
A: Yes, and making them more portable.
Q: Are pencil sharpeners now available for these too? ¶
A: Yes, where a rotating plastic collar holds the pencil in position, although they then sharpen them to the usual conical point as for a round pencil, abandoning all the distinctive aspects of the carpenter's pencil.