who invented the screw lever cap?

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Joel is very well informed about tool history. His blog is somewhere I trust and go to learn things.

The Reeses do say, in BPM III, that Fenn made the earliest known examples of the lever cap.
That's authoritative enough for me.
 
Yes, that's the same family of Fenns.

The text in BPM says that the plane in question was wooden bodied with parallel sides, of smoothing plane size. "The iron is secured by a spring cap and is adjustable by a screw adjuster" One of the three known examples is marked "J Fenn registered 12th Nov 1844"

There's a tiny illustration of a "Fenn Patented block plane" in Tony Murland's book. It looks like this one, sold at David Stanley in 2016. (Hammer price was £850. ) Not what I would have thought of as a screw lever cap, but there is a screw there so I suppose it is.

(The same book also lists a Fenn patent jack plane.)

540x360.jpg


(Just to confuse things, an American Fenn filed a plane patent about the same date - see http://www.handplanepatents.com/no-2911 ... fenn-1884/ - but that's not what we are after.)
 
Thus, from the available evidence so far, it seems that the lever cap was first offered commercially by Joseph Fenn. He was from a London family long associated with the supply of clockmakers' tools, located at 105 and 106 Newgate Street. Joseph was the nephew of Samuel, son of Daniel. Joseph served an apprenticeship with Holtzappfel and Co, a well-respected maker of ornamental and industrial lathes and associated tools. At some point - 1842 or before (end of indenture?) - Joseph left Holtzappfel and rejoined the family firm, presumably bringing new ideas, including maybe the lever cap.

Worth remembering that this era was one of rapid development in the mechanical arts, with new ideas, inventions and techniques bursting forth at a spectacular rate. Some quickly became established, later becoming 'common knowledge', whilst others either fell by the wayside or were developed into forms more familiar today. In this case, it's possible to discern the Fenn spring lever cap being the projenitor of the later Bailey lever cap.

The OP specifically asked about the screw 'lever' cap, a type I associate with infill planes (and some recent Bailey-type planes). I wonder if we're confusing the two types of cap?
 
yes - I was particularly interested in the screw lever cap, however this is because I had wrongly assumed that there had only been two types (thumb screw and the cam version) and that the screw was the first type to be created. I also assumed (wrongly) they had only been produced for metal planes.

All my assumptions were wrong as is clearly shown with Andy's picture above!
 
while digging around I found mention of US made Loughborough planes and there was a picture that showed a thumbscrew lever cap. Unfortunately I can no longer find the website where I saw it (I thought it was on Joel's site, but now I can't find the reference). Anyhow, the site mentioned a patent from 1854 which I think must be this one:

https://patentimages.storage.googleapis.com/pdfs/341e20559e0f7ec296f1/US10748.pdf

The patent is interesting in itself - it is for a combined lever cap & cap iron and the plane described also has a second thumb screw on the reverse side that allows you to change the pitch of the blade.

The patent refers to an earlier patent by someone called Chardoillet (which I can't find), However I did find a picture of the patented plane and it's highly extravagant lever cap on this Russian site:

http://rubankov.ru/museum/2016/10/04/ne-takoj-kak-vse-rubanki-ot-ignace-chardoillet-frantsiya-1852/

it is a hard to tell how it works from the pictures, but it appears to have a lever cap with not one thumbscrew, but two!

Chardoillet-3P.jpg

the text - according to google translate says the French patent was from 1844

Even if this is not the earliest lever cap, it is surely the most ornate!
 
Wow, that's pretty - and a whole new Russian rabbit hole to dive down - thanks for that Nick.

In return, here's a snap of the Chardoillet plane - it's from Roger Smith's Transitional and Metallic Planes in America, volume 1.

IMG_20170224_175110823_zpsytmnhcsw.jpg
 
Just to add that the book doesn't have anything much to say about the Chardoillet plane except for what you have found - that it was referred to in the Loughborough patent. Roger Smith was very thorough in researching US patents and including them in his book - maybe French patents were beyond his reach. It doesn't appear to be on Espacenet, as I expect you have found.

There is a big, colourful, expensive French book on planes - but I don't have a copy.

http://www.editionsvial.com/boutique/outils/les-rabots/
 
let us not forget that there are a number of metal planes known as Nuremburg work that date from the 16th century. these have a metal lever cap- bridge with a large thumb screw to apply pressure to the blade
 
For what it's worth, there is a U.S. patent from February 9, 1831 which seems to be about a type of lever cap for a wood-bodied plane. The patent was issued to Phineas Meigs of Madison, Connecticut (New Haven County). Unfortunately, it was one of the patents lost in the 1836 fire at the patent office, but has been given the patent number X6,370. Fortunately, though the original letters patent and model are lost, it was described in some detail in the publication, _The Repertory of patent Inventions ..._, London, 1833, which has been digitized by Google Books.

Meigs' invention is described as having no wedge and a single flat iron plate with pins about 3/4" from its lower end which fit into grooves in iron plates affixed to the escapement cheeks of the plane. The iron plate also has a thumbscrew near its upper end. The description goes on to state: "The cutting iron is dropped into its place, between the cap iron and the stock; when there, the thumb screw is turned, and its point bearing on the cutting iron, and fixes it in its place; the whole bearing being against the pins in the groove."

I don't know if Meigs' patent ever went into production, so doubt it influenced Fenn. But it does seem that the idea of a screw lever cap pre-dates the 1840's.

Don McConnell
Eureka Springs, AR
 
thanks all - fascinating. Some information on the planes Richard mentioned here:

http://thomasguild.blogspot.co.uk/2014/12/the-medieval-toolchest-plane-part-4.html

hobel%2Bsaxony.jpg


Andy, hopefully you already know about this site, else I am afraid I am the cause of another mammoth rabbit hole for you to go down!

thanks also Don - I did not know about the fire at the USPTO - what a terrible loss of knowledge.
https://en.m.wikipedia.org/wiki/1836_U.S._Patent_Office_fire

https://books.google.co.uk/books?id...=PA21#v=onepage&q=phineas meigs plane&f=false
 
Well this is a worthwhile discussion, getting better and better!

I don't have Greber's book and I hadn't seen that site before, so I've got some more reading to do.

But clearly the answer to the original question is that the use of a screw lever cap predates patent registration. I have read that screw threads were far from common in the medieval period, with only a handful of early examples being known, mostly on armour, clocks and guns.
 
AndyT":50tq5qsr said:
Well this is a worthwhile discussion, getting better and better!

I don't have Greber's book and I hadn't seen that site before, so I've got some more reading to do.

But clearly the answer to the original question is that the use of a screw lever cap predates patent registration. I have read that screw threads were far from common in the medieval period, with only a handful of early examples being known, mostly on armour, clocks and guns.

Thank you for posting this I'm struggling to find a way of uploading images from my computer. Cheers, Richard
 
The 16th century metal planes from Nuremberg have been mentioned in various publications over the years, so I had considered mentioning them in my previous post. Decided not to, though, as I'm not sure they qualify as early examples of screw lever cap planes. At least as I understand them based on the photos.
I think it fair to say that they are precursors of the use of a screw, in the absence of a wedge, as part of a blade holding system, but it doesn't seem there is any lever cap involved. If someone has seen the planes in question and can supply information that lever caps were, somehow, involved, I'll be happy to correct my understanding of them. Otherwise, I don't believe they are actually early examples of screw lever cap planes.
 
The principle of the screw goes back to the time of the Greeks, but until the 15th century they tended to be large - olive oil press screws, for example. From about 1480, they were used in scientific instruments, clocks and the like, but were individually made; each 'screw' was fitted to each 'nut'. The first accurate screwcutting lathe has been credited to instrument maker and mathematician Jesse Ramsden in 1777, and great improvements in accuracy were made by Henry Maudslay in the late 1790s and early 1800s. However, until Joseph Whitworth's work of the early 1840s, there were no standards for screwthreads; each factory had their own preferences for thread angle, pitch and diameters. Thus, fasteners from one maker would fit nobody else's. Each factory made their own taps and dies, and cut and fitted their own threaded fasteners.

Thus, it's possible that a pivoting screw cap of the sort we are familiar with COULD have been made any time after the 15th century, but it would have been a rare and expensive item, made by a specialist scientific instrument maker or clockmaker. It seems more likely that it would have been economically viable only after the introduction of commercially available screwcutting lathes (to make both the tap for the holes, and the screws themselves) in the early to mid 19th century; maybe in the 1825 to 1840 time frame - which fits nicely with the Meig patent.

(Sources of information - 'Tools for the Job' by LTC Rolt, and Wikipedia entries for 'screw' and 'screwthread'.)
 
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