Deaf-Aid Receiver: How Old? - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Cobaltblue · 29th Aug 2011, 4:43 pm

I have found more Ardente this time a PA Amplifier for AC/DC operation. Not sure I would want to use the Phones though!

I suppose it was the practice in 1938
Enjoy

Mike T

emeritus · 29th Jan 2012, 1:37 am

The back of the earphone has a patent number 553391. This UK patent was granted on 19 May 1943, so it must have been manufactured after this date. The patent relates to a light-weight construction for use in hearing aids etc. You can view the patent here:

http://worldwide.espacenet.com/publi...m&locale=en_EP

russell_w_b · 29th Jan 2012, 11:52 pm

Thanks for that, Emeritus. Interesting web site!

emeritus · 1st Feb 2012, 2:16 am

Espacenet is pretty good for finding patent information, but it has to be borne in mind that some UK data prior to about 1920 is missing. This fact is not mentioned anywhere and I only found this out when trying to download some of Ferranti's early patents relating to his AC power systems for which I had the actual patent numbers.

Apparently the European Patent Office (EPO) relies on infomation supplied by the UK Patent Office, and for some reason, some of the info from the 19th century got left off. What with government cutbacks and manpower shortages, it is unlikely that the gaps will ever be filled, and if you draw a blank when looking up a number, you will have to contact the Patent Office (or as it now calls itself, the "Intellectual Property Office") in Wales if you want a hard copy. The SRIS at St Pancras, London, holds complete printed copies of all the early UK patents, and these are available for personal inspection, but they will now not supply photocopies of anything pre-1900 due to the fragility of their older documents.

Finding a patent number on something doesn't necessarily mean that the patent will relate to the thing you are interested in. I have a BC adaptor that has been in the family for as long as I can remember and looks as if it is designed to provide an earthed connection by making contact with a suitable brass lampholder: however the patent number it carries only relates to the cord grip and does not mention earthing at all.

Re the 2 pin 2A plugs and sockets, although I understand these were prohibited for mains wiring after about 1948, they were still on sale in my local Woolworths in the mid-1960's. I still have some that I used for a 12V DC supply powered by my train set controller. 2 pin 2A flex extenders to the same gauge that could only be used with figure-of-eight mains flex were still being sold by Woolworths into the 1970s.

29th Aug 2011, 4:43 pm	#21
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,879	Re: Deaf-Aid Receiver: How Old? I have found more Ardente this time a PA Amplifier for AC/DC operation. Not sure I would want to use the Phones though! I suppose it was the practice in 1938 Enjoy Mike T Attached Thumbnails __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

29th Jan 2012, 1:37 am	#22
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,349	Re: Deaf-Aid Receiver: How Old? The back of the earphone has a patent number 553391. This UK patent was granted on 19 May 1943, so it must have been manufactured after this date. The patent relates to a light-weight construction for use in hearing aids etc. You can view the patent here: http://worldwide.espacenet.com/publi...m&locale=en_EP

29th Jan 2012, 11:52 pm	#23
russell_w_b Dekatron Join Date: Jul 2007 Location: Penrith, Cumbria, UK. Posts: 3,687	Re: Deaf-Aid Receiver: How Old? Thanks for that, Emeritus. Interesting web site! __________________ Regds, Russell W. B. G4YLI.

1st Feb 2012, 2:16 am	#24
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,349	Re: Deaf-Aid Receiver: How Old? Espacenet is pretty good for finding patent information, but it has to be borne in mind that some UK data prior to about 1920 is missing. This fact is not mentioned anywhere and I only found this out when trying to download some of Ferranti's early patents relating to his AC power systems for which I had the actual patent numbers. Apparently the European Patent Office (EPO) relies on infomation supplied by the UK Patent Office, and for some reason, some of the info from the 19th century got left off. What with government cutbacks and manpower shortages, it is unlikely that the gaps will ever be filled, and if you draw a blank when looking up a number, you will have to contact the Patent Office (or as it now calls itself, the "Intellectual Property Office") in Wales if you want a hard copy. The SRIS at St Pancras, London, holds complete printed copies of all the early UK patents, and these are available for personal inspection, but they will now not supply photocopies of anything pre-1900 due to the fragility of their older documents. Finding a patent number on something doesn't necessarily mean that the patent will relate to the thing you are interested in. I have a BC adaptor that has been in the family for as long as I can remember and looks as if it is designed to provide an earthed connection by making contact with a suitable brass lampholder: however the patent number it carries only relates to the cord grip and does not mention earthing at all. Re the 2 pin 2A plugs and sockets, although I understand these were prohibited for mains wiring after about 1948, they were still on sale in my local Woolworths in the mid-1960's. I still have some that I used for a 12V DC supply powered by my train set controller. 2 pin 2A flex extenders to the same gauge that could only be used with figure-of-eight mains flex were still being sold by Woolworths into the 1970s.