Some interesting patents
Re: Some interesting patents
lava lamps
https://patents.google.com/patent/US338 ... =us3387396
https://patents.google.com/patent/US357 ... =us3570156
https://patents.google.com/patent/US338 ... =us3387396
https://patents.google.com/patent/US357 ... =us3570156
Re: Some interesting patents
Frictional electrical generator
https://patents.google.com/patent/US331 ... q=us331754
https://patents.google.com/patent/US331 ... q=us331754
Re: Some interesting patents
https://patents.google.com/
Tubes at the USPTO
You can find a lot of audio circuits including tube based circuits in the patent collection at the USPTO (and other countries). The USPTO recently threw away their entire collection of hard copies after starting to put all of the patents on computer databases which are available on the internet and can also be searched using databases like EAST and WEST at the USPTO. Besides searching by class and subclass, you can do keyword searching using a patent database, look at other patents listed as references in patents and use patent numbers of patents you found already as keywords to find newer patents that list them as references (forward search). The USPTO and Espacenet have entire collections of patents available on the interent for free. Espacenet has US and foreign patents. EAST and WEST at the USPTO have both US and some foreign patents avaialable, but I don't know if the foreign patents are available on the USPTO web site. Companies like Micropatent have collections of patents available on the internet, but usually aren't free. There's about 80+ libraries around the country (USA) from what I remember that have facilities for doing patent searching or just looking at patents (ie. on microfilm). I heard years ago that many of these libraries had the APS computer system for searching patents. They might have EAST and WEST now, but I don't know for sure. The public can use the EAST and WEST terminals for free at the USPTO (now located in old town Alexandria, Virginia) after getting a permanent or temporary pass. Patent examiners, clerks and other USPTO employees have their own EAST, WEST and other database terminals.
To view patents go to http://patft.uspto.gov/netahtml/PTO/srchnum.htm or http://gb.espacenet.com
Both text for later patents and images for all patents are available at the USPTO web site, but you might need a TIFF browser plug-in to view images from the USPTO. I use Alternatiff available from http://www.alternatiff.com . Patents at Espacenet are in pdf form and require Adobe Acrobat Reader to read them, available for free at http://www.adobe.com .
Since I was interested in tubed FM stereo mpx adapters I started with this subject. Searching using the keyword "stereo" in class 329 and then looking through class 381 subclasses 4, 7, 8 and 9, I found these US patents:
3167615 two triodes with diode ring modulator
3226481
3294912 transistors, detailed, shows L+R, L-R and SCA diagram
3854098 quadraphonic demodulator for records
3617641 transistor detail in IC 20
3124653 tubes, 19kHz full wave rectifier
3175040 two ring modulators, balanced
3175041 time division switching
3287501 clipper 35, diodes 31 and 32 - full wave rectification of 19 kHz signal (see column 2 lines 49+)
3209270 strange demodulator tube 20
Here's some examples of tube amps I found in class 381 subclasses 118, 119, 122 and 123:
2815407 Hafler ultralinear
2710312 Hafler ultralinear
4066975 HiFi tube, Paoli High Fidelity Consultants
2773136 Futterman OTL
2904644 voltage regulation in HiFi tube amp w/ EL34/6CA7
Some McIntosh amps:
2477074
3573648
2860192
2654058
2646467
------------------
More patents. Most are on tube audio power amplifiers.
Class 330 subclass 118
3092783 OTL
3096486 push-pull parallel
3153766 diodes -> screen grid
3566236 cathodes coupled to secondary of transformer, screen grids -> triode -> cathodes & B+
4918394 cascode input
5302912 reduced crossover distortion
5498996 plural output tubes, suppression
Class 330 subclass 119
2921266 self balancing
2919411 two phase splitters, parallel output tubes, push-pull
2595444 transformer coupling to cathodes and control grids
2918630 strange driver circuit
2833871 self balancing phase inverter
2777905 low distortion
2825766 cathode coupling, McIntosh Labs Inc.
Class 330 subclass 123
2772329 supersonic "bias" reduces crossover distortion
2934714 low distortion
3005162 VR tube -> screen grids
3138766 volume limiter/expander
4532476 two class simultaneously
4593251 two class simultaneously
https://www.flickr.com/photos/62345920@N00
Tubes at the USPTO
You can find a lot of audio circuits including tube based circuits in the patent collection at the USPTO (and other countries). The USPTO recently threw away their entire collection of hard copies after starting to put all of the patents on computer databases which are available on the internet and can also be searched using databases like EAST and WEST at the USPTO. Besides searching by class and subclass, you can do keyword searching using a patent database, look at other patents listed as references in patents and use patent numbers of patents you found already as keywords to find newer patents that list them as references (forward search). The USPTO and Espacenet have entire collections of patents available on the interent for free. Espacenet has US and foreign patents. EAST and WEST at the USPTO have both US and some foreign patents avaialable, but I don't know if the foreign patents are available on the USPTO web site. Companies like Micropatent have collections of patents available on the internet, but usually aren't free. There's about 80+ libraries around the country (USA) from what I remember that have facilities for doing patent searching or just looking at patents (ie. on microfilm). I heard years ago that many of these libraries had the APS computer system for searching patents. They might have EAST and WEST now, but I don't know for sure. The public can use the EAST and WEST terminals for free at the USPTO (now located in old town Alexandria, Virginia) after getting a permanent or temporary pass. Patent examiners, clerks and other USPTO employees have their own EAST, WEST and other database terminals.
To view patents go to http://patft.uspto.gov/netahtml/PTO/srchnum.htm or http://gb.espacenet.com
Both text for later patents and images for all patents are available at the USPTO web site, but you might need a TIFF browser plug-in to view images from the USPTO. I use Alternatiff available from http://www.alternatiff.com . Patents at Espacenet are in pdf form and require Adobe Acrobat Reader to read them, available for free at http://www.adobe.com .
Since I was interested in tubed FM stereo mpx adapters I started with this subject. Searching using the keyword "stereo" in class 329 and then looking through class 381 subclasses 4, 7, 8 and 9, I found these US patents:
3167615 two triodes with diode ring modulator
3226481
3294912 transistors, detailed, shows L+R, L-R and SCA diagram
3854098 quadraphonic demodulator for records
3617641 transistor detail in IC 20
3124653 tubes, 19kHz full wave rectifier
3175040 two ring modulators, balanced
3175041 time division switching
3287501 clipper 35, diodes 31 and 32 - full wave rectification of 19 kHz signal (see column 2 lines 49+)
3209270 strange demodulator tube 20
Here's some examples of tube amps I found in class 381 subclasses 118, 119, 122 and 123:
2815407 Hafler ultralinear
2710312 Hafler ultralinear
4066975 HiFi tube, Paoli High Fidelity Consultants
2773136 Futterman OTL
2904644 voltage regulation in HiFi tube amp w/ EL34/6CA7
Some McIntosh amps:
2477074
3573648
2860192
2654058
2646467
------------------
More patents. Most are on tube audio power amplifiers.
Class 330 subclass 118
3092783 OTL
3096486 push-pull parallel
3153766 diodes -> screen grid
3566236 cathodes coupled to secondary of transformer, screen grids -> triode -> cathodes & B+
4918394 cascode input
5302912 reduced crossover distortion
5498996 plural output tubes, suppression
Class 330 subclass 119
2921266 self balancing
2919411 two phase splitters, parallel output tubes, push-pull
2595444 transformer coupling to cathodes and control grids
2918630 strange driver circuit
2833871 self balancing phase inverter
2777905 low distortion
2825766 cathode coupling, McIntosh Labs Inc.
Class 330 subclass 123
2772329 supersonic "bias" reduces crossover distortion
2934714 low distortion
3005162 VR tube -> screen grids
3138766 volume limiter/expander
4532476 two class simultaneously
4593251 two class simultaneously
https://www.flickr.com/photos/62345920@N00
Re: Some interesting patents
Forming configurations on natural growths
https://patents.google.com/patent/US209 ... =us2096507
Method and apparatus for molding fruits
https://patents.google.com/patent/US482 ... =us4827666
Velocipede
https://patents.google.com/patent/US109 ... q=us109644
Tricycle.
https://patents.google.com/patent/US103 ... =us1031280
Television with scent effects
https://patents.google.com/patent/US254 ... =us2540144
https://patents.google.com/patent/US209 ... =us2096507
Method and apparatus for molding fruits
https://patents.google.com/patent/US482 ... =us4827666
Velocipede
https://patents.google.com/patent/US109 ... q=us109644
Tricycle.
https://patents.google.com/patent/US103 ... =us1031280
Television with scent effects
https://patents.google.com/patent/US254 ... =us2540144
Re: Some interesting patents
Apparatus and method for remotely monitoring and altering brain waves
https://patents.google.com/patent/US395 ... =us3951134
Long lasting euphoriant resin for cats
https://patents.google.com/patent/US380 ... =us3808312
Dialog between TV movies and human viewers
https://patents.google.com/patent/US430 ... =us4305131
Camouflaged syringe container
https://patents.google.com/patent/US251 ... =us2515413
Lighter-than-air-furniture
https://patents.google.com/patent/US488 ... =us4888836
Fire alarm device for beds
https://patents.google.com/patent/US254 ... =us2544946
Tapeworm-trap
https://patents.google.com/patent/US119 ... oq=us11942
Psychedelic device attachable to front of television tube
https://patents.google.com/patent/US365 ... =us3657474
Costume
https://patents.google.com/patent/US472 ... =us4722098
Vibrator apparatus
https://patents.google.com/patent/US234 ... =us2347554
https://patents.google.com/patent/US395 ... =us3951134
Long lasting euphoriant resin for cats
https://patents.google.com/patent/US380 ... =us3808312
Dialog between TV movies and human viewers
https://patents.google.com/patent/US430 ... =us4305131
Camouflaged syringe container
https://patents.google.com/patent/US251 ... =us2515413
Lighter-than-air-furniture
https://patents.google.com/patent/US488 ... =us4888836
Fire alarm device for beds
https://patents.google.com/patent/US254 ... =us2544946
Tapeworm-trap
https://patents.google.com/patent/US119 ... oq=us11942
Psychedelic device attachable to front of television tube
https://patents.google.com/patent/US365 ... =us3657474
Costume
https://patents.google.com/patent/US472 ... =us4722098
Vibrator apparatus
https://patents.google.com/patent/US234 ... =us2347554
Re: Some interesting patents
Design for a convertible chair and table
https://patents.google.com/patent/USD14 ... =usd147671
wall paper
https://patents.google.com/patent/USD69 ... q=usd69111
shawl
https://patents.google.com/patent/USD74 ... q=usd74671
wall paper
https://patents.google.com/patent/USD64 ... q=usd64892
Method of treating eggs to produce chicks having coloeed down
https://patents.google.com/patent/US247 ... =us2477752
Laying-register for fowls.
https://patents.google.com/patent/US124 ... =us1243271
Iceberg propulsion system
https://patents.google.com/patent/US433 ... =us4334873
Toy atomic waste disposal car
https://patents.google.com/patent/US303 ... =us3034256
Skyboard
https://patents.google.com/patent/US489 ... =us4898345
Hydrofoil surfboards
https://patents.google.com/patent/US374 ... =us3747138
Deodorant spray toilet paper hanger
https://patents.google.com/patent/US274 ... =us2746798
Paddle
https://patents.google.com/patent/US151 ... =us1512391
Jacket
https://patents.google.com/patent/USD25 ... =usd256514
Combined burglar frightening device and alarm
https://patents.google.com/patent/US421 ... =us4212007
https://patents.google.com/patent/USD14 ... =usd147671
wall paper
https://patents.google.com/patent/USD69 ... q=usd69111
shawl
https://patents.google.com/patent/USD74 ... q=usd74671
wall paper
https://patents.google.com/patent/USD64 ... q=usd64892
Method of treating eggs to produce chicks having coloeed down
https://patents.google.com/patent/US247 ... =us2477752
Laying-register for fowls.
https://patents.google.com/patent/US124 ... =us1243271
Iceberg propulsion system
https://patents.google.com/patent/US433 ... =us4334873
Toy atomic waste disposal car
https://patents.google.com/patent/US303 ... =us3034256
Skyboard
https://patents.google.com/patent/US489 ... =us4898345
Hydrofoil surfboards
https://patents.google.com/patent/US374 ... =us3747138
Deodorant spray toilet paper hanger
https://patents.google.com/patent/US274 ... =us2746798
Paddle
https://patents.google.com/patent/US151 ... =us1512391
Jacket
https://patents.google.com/patent/USD25 ... =usd256514
Combined burglar frightening device and alarm
https://patents.google.com/patent/US421 ... =us4212007
Re: Some interesting patents
Footstool
https://patents.google.com/patent/USD29 ... =usd296622
Dimmer control switch assembly for lamps and the like
https://patents.google.com/patent/US449 ... =us4490625
Jalopy shelf for bottles
https://patents.google.com/patent/US405 ... =us4052114
Fire escape
https://patents.google.com/patent/US912 ... q=us912152
Table construction
https://patents.google.com/patent/US459 ... =us4594950
Process of electrically extracting essential oil.
https://patents.google.com/patent/US763 ... q=us763151
Novelty clock
https://patents.google.com/patent/US326 ... =us3262258
Clock
https://patents.google.com/patent/USD22 ... =usd228303
Sensory stimulation enclosure
https://patents.google.com/patent/US464 ... =us4640266
Construction toy amusement device
https://patents.google.com/patent/US330 ... =us3300891
Amusement device
https://patents.google.com/patent/US237 ... =us2373367
https://patents.google.com/patent/USD29 ... =usd296622
Dimmer control switch assembly for lamps and the like
https://patents.google.com/patent/US449 ... =us4490625
Jalopy shelf for bottles
https://patents.google.com/patent/US405 ... =us4052114
Fire escape
https://patents.google.com/patent/US912 ... q=us912152
Table construction
https://patents.google.com/patent/US459 ... =us4594950
Process of electrically extracting essential oil.
https://patents.google.com/patent/US763 ... q=us763151
Novelty clock
https://patents.google.com/patent/US326 ... =us3262258
Clock
https://patents.google.com/patent/USD22 ... =usd228303
Sensory stimulation enclosure
https://patents.google.com/patent/US464 ... =us4640266
Construction toy amusement device
https://patents.google.com/patent/US330 ... =us3300891
Amusement device
https://patents.google.com/patent/US237 ... =us2373367
Re: Some interesting patents
US 3530224 FOOT CONTROLLED CONTINUOUSLY VARIABLE PREFERENCE CIRCUIT FOR MUSICAL
INSTRUMENTS
Plunkett
US 3769871 STONE GUITAR WITH TUNED NECK
US 3866505 Ensemble effect imparting device using a bucket brigade device for an electric musical instrument
US 3886835 Tremulant and chorus generating system for electrical musical instruments
Leslie and phase modulation/shifting
US 4075921 String instrument vibration initiator and sustainer
US 4206678 Introduced in the mechanical and functional structure of stringed instruments
US 4245540 Sound sustaining device for musical instruments
US 4308780 Warp restoring device for the neck of a stringed musical instrument
US 4372186 Humbucking electromagnetic pickup for stringed musical instruments
US 4697491 Electric feedback guitar
US 4928564 Apparatus and method for stabilizing a tremolo on a musical instrument such as a guitar
US 4937874 Emulated guitar loudspeaker
INSTRUMENTS
Plunkett
US 3769871 STONE GUITAR WITH TUNED NECK
US 3866505 Ensemble effect imparting device using a bucket brigade device for an electric musical instrument
US 3886835 Tremulant and chorus generating system for electrical musical instruments
Leslie and phase modulation/shifting
US 4075921 String instrument vibration initiator and sustainer
US 4206678 Introduced in the mechanical and functional structure of stringed instruments
US 4245540 Sound sustaining device for musical instruments
US 4308780 Warp restoring device for the neck of a stringed musical instrument
US 4372186 Humbucking electromagnetic pickup for stringed musical instruments
US 4697491 Electric feedback guitar
US 4928564 Apparatus and method for stabilizing a tremolo on a musical instrument such as a guitar
US 4937874 Emulated guitar loudspeaker