An oil filled sound-box ?

[poodling around]

I thought that this was intriguing.

Unfortunately, as some-one I once knew quite accurately described me, I have "the attention span of a Gnat" - so I may mis-understand a little.

How-ever, this seems to be a patent for two things revolving around a sound-box diaphragm being 'cushioned' at the tone-arm end with something like a gasket filled with oil.

Apparently such a thing can improve sound and lubricate the gramophone needle.

Very interesting stuff indeed.

https://www.the-saleroom.com/en-gb/auct ... b215c5b30a

[Inigo]

Beefy intriguing... I wanted to write VERY but we'll stay with beefy, much more graphic.
I wonder how the sound can pass to the tonearm, if there's a second mics disk closing the neck. Oil replaces air inside the soundbox, and takes the needle vibrations. But how these are then transmitted back to the air inside the tonearm?
In the other hand, I read somewhere, many moons ago, that Edison engineers used oil dampened recorders, and that was part of the secret of the good sound they achieved in acoustic recordings... Maybe those were similar to what seems to be in this patent.

[poodling around]

Beefy intriguing... I wanted to write VERY but we'll stay with beefy, much more graphic.
I wonder how the sound can pass to the tonearm, if there's a second mics disk closing the neck. Oil replaces air inside the soundbox, and takes the needle vibrations. But how these are then transmitted back to the air inside the tonearm?
In the other hand, I read somewhere, many moons ago, that Edison engineers used oil dampened recorders, and that was part of the secret of the good sound they achieved in acoustic recordings... Maybe those were similar to what seems to be in this patent.

Ha ha ! I agree with you - totally beefy !

Anyway, I found the two patents but haven't yet had the chance to see / read in detail.

Here they are: (both the second ones down):

https://worldwide.espacenet.com/patent/ ... A?q=340054

https://worldwide.espacenet.com/patent/search?q=392641

[herrickpickups]

this oil filled concept was the basis of an early HMV electro-magnetic pickup. the wireless world covers it & pictures it's internals in March 14th issue 1928 & the image was reproduced into the "modern gramophones & electric reproducers" book by Wilson & Webb. The oil serves to dampen the spring steel diaphragm that the needle bar is soldered to with a gap to the pole pieces connected to a large horseshoe magnet in the larger body, which was in the 2nd, dry part of the device.

[Inigo]

I once had a 1950s Philips record player with an oil dampened cartridge. I disassembled it and saw a kind of thick oil inside.