This is a special category of pencils that I collect but have found absolutely no information about on the web except for a few online art supply stores who still sell new ones.
The mechanics of these pencils are, in general, not unique; you can find examples of their various lead holding mechanisms (eg. push-button spring clutch, twist-lock clutch, and, occasionally, auto-advancing mechanisms) in the recognized types of mechanical pencils, however, unlike most collectable pencils, they are "working pencils," that is, they are not designed as decorative objects. Their aesthetic is really more akin to workaday wooden pencils, replete with foil-stamped markings on the barrels.
Another attribute common among them is the diameter of their lead. The most common lead diameter being 2mm. Use of the 2mm lead holders, it should be noted, has been in decline amongst the also declining ranks of manual draftsmen for decades in favor of pencils with smaller diameters of lead that do not requiring pointing. These smaller diameter (0.3mm, 0.5mm, 0.7mm, and, rarely, 0.9mm) pencils invariably have an auto-advancing clutch mechanism akin to the common "mechanical pencil."
The history of lead holders, I think, is nearly closed. Their use amongst architects and draftsmen has diminished such that there are few manufacturers still producing them, and even fewer, I'm sure, with any desire to improve them.
Based on my meager knowledge of these things I date the instrument's origin as a precision drafting tool at c. 18801900. Lead holders of a kind are known to have been in existence much earlier, but they were not suited to the exacting nature of drafting.
Visit Dennis' web site devoted to lead holders: http://www.leadholder.com
Many thanks to:Dennis B. Smith
Art Director/UI Architect