Another mystery tool.

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Established Member
23 May 2011
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Western Australia.
Hello all,
What do you think this is? It looks like the shoulder pad of a breast drill, the only info' is "PATENT" stamped into the shank, tapered square socket on end without provision for a locking screw.
Length overall: 4 1/2" length of pad: 4". Socket tapers from 21/32" to 15/32" over depth of 1 3/8", very similar dimensions to Morse square taper bit. Remnants of red paint visible.
Any ideas?


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Interesting one. Although I can see it looks like a breast drill pad, they all curve the other way, and do need a screw or something to stay attached. So at first I tried to think of something big that would need bodily pressure - maybe in drilling rock when mining, or laying railway tracks? But the square socket doesn't look right for something that needs holding in place so it can be rotated. And the casting isn't for turning itself, not with its thin edges.

So I don't know, but I can't imagine any drilling application where it would work. Maybe the square socket is important so as to keep the curved end oriented the right way when it moves? And possibly the application needs a variety of different sized ends, easily swapped.

So my wild guess/suggestion of where to look next would be something to do with tyre fitting, where it would be stretching outwards, pressing against a tyre fairly closely conforming to the shape. Do such things exist? Or maybe there's some other sort of work where it needs to push against something which isn't a human body but needs gentle edges?

If you take the curve as part of a circle, how big would the circle be? (How much room inside it for some other gubbins?)

EDIT - ok Bob's brief reply took less time to post and beat me to it, but I'll post anyway.

Bob, is that a known answer based on experience or just a guess? It's a pretty weird shape if you are going to be rotating it - why not make the edges wider? - and a very short shaft unless you use it with an extension piece.
I recon it's a key... most likely for a tap. I used to keep one of the circular ones because they fit onto the tapered end of a twist bit (for boring a hole in very tight spots!
Andy, I've been working with gas and plumbing fittings since 1964 :shock:
I was born in a house that still had gas lighting. Bear in mind what I was working on then was usually easily 50 or more years old, I've seen a lot of weird victorian stuff. :roll:

Many stop puffins back then had removable handles to stop people fiddling with them when they were fitted in public places. I doubt you are old enough to remember public convenience urinals that were all fed from a central tank with a partly open valve to regulate the filling speed. Quite often the attendant would keep goldfish in the glass tank. :shock:
Back then every company made their own valves and handles. I have not seen that particular model, but its a very good bet that I have the answer. 8) 8)
The PC computer has struck again, OBVIOUSLY I am not taking about Puffins
Thanks Bob,
I can see that the socket is like the one on a key for the water mains stopcock outside a house so what you say makes sense, but I still don't see why it would be that particular shape if it was made for twisting around its axis.
I was asked if I had experience of the item. I provided my relevant experience, along with what I thought was an interesting anecdote. If that's too much information for you I suggest you only read the first line of my posts.
looks like it should be on the bottom of a wooden leg...

could it be part of an interchangeable last that a cobbler or similiar might use
"let me ponder" (as my 3 yr old grandson picked up from someone)
I use a square socket tap key all summer for my allotment water tap - the socket's OK for this (or a bed key, or gas key etc) and I even have a (1940s?) Wards workbench with taper square head bolts this might well fit, but why the carefully cast convex 'pad'?
some early (eg about 1900) little vices (eg bench clamp-type) had a little anvil - round, square or beaked - this could fit on such as a home last as suggested by haggis - home shoe mending big back then.
how about a 1920 patented design for a "mystery tool - to be discussed during virus lock-down one hundred years from now"?
still no?

-- sorry -- already got cabin fever, despite a house and two sheds
I agree, it is not a comfortable shape for a handle you'd grip to turn because of the gussets and the thin edge of the pad. Unless you're reaching above shoulder height which changes how your hand contacts the pad. So maybe it is for a valve on a toilet cistern mounted high on a wall? it seems a large tapered socket for a small amount of leverage.
I do like the idea of a shoe last as suggested by Flying Haggis. As far as the bottom of a wooden leg goes, when I was very young my Uncle Sid wore a boot with a built up sole due to one leg being shorter than the other which is where this might have worked for him.
Also why stamp the single word "patent" for something as common as a valve handle?
Thanks for your comments so far.

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