Bottom half of a domestic coffee grinder?

Going by the Patent No.

https://worldwide.espacenet.com/patent/search?q=pn%3DGB190324189A

… a ‘developed’ version of Mr Burton’s Razor Sharpening Machine !

MichaelG.

Bobbin Winder ?  OR Vintage Jewellers Turntable Bench as picture below

I fail to see how it can be anything other than an incomplete specimen of what’s in Michael’s link.

Ooh, in which case do please elucidate with photos of the finished tool and its use!

The patent specification, written in that gorgeous mix of legalese and proper technical language, shows a tool whose principle is that of the edge-tool sharpening machines in wood-working.

One of Holtzappfel’s books shows an alternative with the honing surface stationery: I think called a Gnomiometer. No, not for ensuring horticultural figurines’ ISO9001 compliance, but a tool-holder on two orthogonal protractor frames so the ground edge is held at the requisite compound angle for lapping on an abrasive plate.

On 15 November 2025 at 16:28 Martin King 2 Said:

[…]

Having looked at MichaelG’s patent drawing it would appear that there is an arm part which holds the straight razor at the correct angle for sharpening. […]

that would be the feature which makes it comparable with the aforementioned Goniometer.

MichaelG.

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Understood, Martin … I remain somewhat bewildered by what development may have occurred twixt patent and product.

MichaeG.

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Edit: __ There appears to be some fretting in this area … I wonder if the angular adjustment clamped on to that boss ?

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You have to remember that patent drawings, whilst often a good guide, are necessarily those of an early model, or even a prototype. The production version will frequently have practical changes and improvements which fall within the scope of the patent, but are not illustrated by updated drawings because there is no facility to add them ( nor any need to do so).

A Goniometer is a device for measuring angles – I have some memory of using one in ‘A’ level physics, possibly for measuring diffraction of light.

I think it’s a general term, rather than describing a particular design of gadget.

On 15 November 2025 at 20:32 Andy Stopford Said:

A Goniometer is a device for measuring angles – I have some memory of using one in ‘A’ level physics, possibly for measuring diffraction of light.

I think it’s a general term, rather than describing a particular design of gadget.

Very much so

MichaelG.

On 15 November 2025 at 18:42 Bazyle Said:

A razor very quickly develops a curved edge during manual sharpening so the fixed holder was probably found not to work very well.

I agree.   My experience with cut-throat razors comes from microscopy where they are used to slice very thin sections.   Posh folk own microtomes, a machine that holds the specimen and drives the blade.  Poor relations use a cut-throat and it has to be VERY sharp.

Best to not let  a cut-throat get blunt enough to need a regrind, the trick is regular stropping on a leather belt, with the occasional light touch up grind.  Stropping on a belt isn’t difficult, and I don’t see much advantage in a spinning disc.

Two forms of razor:

• Cheaper straight-ground razors.   The shape is good for slicing specimens rather than shaving,  don’t know why.
• In the past only barbers and rich people bought expensive hollow ground razors.  They were much imitated – cheap razors made of inferior steel and crudely hollow-ground, to fool innocents.  Birmingham was world famous for cheap nasty tat.   I’m not sure a hollow ground razor would strop well on a wheel, might be a good way of spoiling a high-end razor.

We’ve mostly forgotten cut-throat razors were once very expensive and highly desirable.  In Victorian times “buy cheap buy twice” was mostly true, so there was a lot of mystique and dodgy goings on.  Poor quality blades sold in gilded boxes and sharpening aids that didn’t work that fleeced the unwary hoping to save a few bob.  Customers spent good money on gizmos that would magically turn a poor razor into a good one.  Or at least keep it a little sharper!

This tool may be a gimmick.   Anyone remember when safety razors were sharpened by leaving them under pyramids:

Modern steel and manufacturing methods put the kybosh on razor mystique.   A scientifically formulated stainless steel is rolled into a thin strip, which is punched, hardened, and ground and honed to a super-sharp edge by a machine. Hardly any metal in it, so dirt cheap – no need to resharpen them, disposable.

Cut-throats still have a niche though.  Anyone use one?  And if so how do you keep it sharp?

Dave