Lansing-related Patent Parade

[moldyoldy]

Ever wondered about the evolution of magnet structures for loudspeakers? How about diaphragm production techniques?


Got an original idea you'd like to retire on and want to ensure no one has beat you to it?


Wanna step into a time machine of technology?


Been posting too much nonsense, and need something different to do?


If you answered Yes to any of that rot, you may qualify as a patent surfer.


Some of you have been doing this for some time. You can share your favorite "finds" here.


For newbs, I've collected some info here to help you get started. Other tips and hints are welcomed. I've not yet ventured into International waters, so what I'm posting (may be) limited to US patents.


Just about when you think you've had a wazoo-full of "prior art" and never-ending drawing descriptions, you'll come across something so hilariously ridiculous you'll just have to look at more.


Let's try to stay on Lansing-related products, unless the dialog warrants something else appropriate. I'll start with a list of Altec patents I've found so far. Should be pretty easy to assemble a complete listing of Lansing Heritage product patents in a short time.


I hope this thread becomes something of merit and useful to those interested in such things. If that should be the case, I reserve the right (and accept the responsibility) for creating an organized, condensed version for the Lansing Heritage record. (if desired)


Keep it between the ditches! ;)

[moldyoldy]

United States Patent and Trademark Office (http://www.uspto.gov/index.html)


Straight from the horses mouth. Also the hard way to do it. Searching patents here requires dedication. Read for reference, but skip down to "Google" for daily use.


It's all here. 1976 to current patents are text-searchable. Drawings and text on drawing pages are saved as images.

For pre-1976 patents, scanned originals are stored entirely as images, thus searching is limited to info in the filename, namely, the patent number, the patent date, or the "Current US Classification".


90% of the stuff in which we're interested, is in "Current US Classification" 181/xxx, (Acoustics), (http://www.uspto.gov/web/patents/classification/uspc181/sched181.htm) with the x's representing one of the many subclasses (or a wildcard). To be thorough, pull up everything in the subclass of interest, and weed 'em out. Surprisingly, some subclasses have only a few entries.


" USPTO's full-page images, nearly four terabytes overall, are stored and delivered at full 300 dots per inch (d.p.i.) resolution in an image file format called "TIFF," using CCITT Group 4 compression. This is the format which is required by the international standards to which all patent offices must conform. TIFF is also the most used lossless image format in the world.


"Unfortunately, due to the volume of the image data, available funding, and other technical considerations, PTO cannot convert these images to a format more popular on the Web either permanently or by converting on-the-fly as they are delivered."

"As a result, you must install and use a browser plug-in -- similar to those required to access Adobe® PDF files, RealPlayer®, or Macromedia Flash® files -- on your workstation in order to view these files directly. An alternative method is to use third-party software or services to view these images either directly or after conversion to another format, such as Adobe® PDF. "


"The plug-in you use cannot be just any TIFF image plug-in. It must be able to specifically display TIFF files using ITU T.6 or CCITT Group 4 (G4) compression."


"The only free, unlimited time TIFF plug-ins offering full-size, unimpeded patent viewing and printing unimpeded by any advertising on Windows® x86 PCs of which we are aware are:

• AlternaTIFF: http://www.alternatiff.com/ (tested: IE, Netscape, Opera)
• interneTIFF: http://www.internetiff.com/ (tested: IE, Netscape)
For the Apple Macintosh®, Apple's freely distributed QuickTime version 4.1 or later works with our images for pre-Safari Macintosh, but does not provide direct printing capability. Please visit http://www.apple.com/software/ and type "patent" to locate plug-ins for recent versions of Macintosh browsers "


"For Linux®, a plug-in called "Plugger" works nicely with Netscape Communicator®. It is available at http://fredrik.hubbe.net/plugger.html""


On my PC, AlternaTiff blows QuickTime away. YMMV.

[moldyoldy]

Googling patents (http://www.google.com/patents).

.
Surfing as it should be!

"Google Patent Search covers the entire collection of patents made available by the USPTO—from patents issued in the 1790s through those issued in the middle of 2006. We don’t currently include patent applications, international patents, or U.S. patents issued over the last few months, but we look forward to expanding our coverage in the future."


." Using the same technology that powers Google Book Search, Google has converted the entire image database of U.S. patents into a format that’s easy to search. You can search the full text of U.S. patents from the Google Patent Search homepage (http://www.google.com/patents) , or visit the Advanced Patent Search page (http://www.google.com/advanced_patent_search) to search by criteria like patent number, inventor, and filing date".

Things get fun here. Search by inventor, assignee, keywords, whatever. Google's OCR engine is awesome, but sometimes fumbles, like on "Loudspeaker with Expanding Hoen" Altec's '51 Duplex patent. Still pretty darn good considering some of the paper documents were 200+ years old when they were scanned!

TIPS

Lots of new leads appear in the "References cited". Also the reason for occasional multiple hits, which can become an indicator on its' own, as commonly-cited patents become so for a reason.

Patents beginning with "D" are design patents, drawings or images of specific ornamental appearance.

Narrow your search by a date range, either by filed date, or by issue date (often 2-4 years apart). I consider the filing date of more significance for obvious reasons.

After reading a few, you'll get a feel for the lingo which will aid in searching. For instance, "acoustical transformer" may get more hits from the old days than "phase plug", which is a more modern term. Trade names (i.e. Duplex or VOTT) seldom appear in patent text unless specically named as an integral part of the patent.

[moldyoldy]

Following is a list of Altec Lansing patents (not including Altec Lansing Technologies or University Sound). I believe it to be complete, but please add any more you find.


LOUD-SPEAKER WITH EXPANDING HORN (http://www.google.com/patents?id=JAhlAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2568883 Filed: Mar 24, 1947

COMBINED MICROPHONE AND STAND UNIT (http://www.google.com/patents?id=iD1vAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D157724 Filed: Apr 25, 1949

SHIELDED CONDENSER MICROPHONE (http://www.google.com/patents?id=buFWAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2579162 Filed: Feb 24, 1950

SHIELDED CABLE SYSTEM FOR MICROPHONES AND THE LIKE (http://www.google.com/patents?id=jo9IAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2716187 Filed: Feb 24, 1950

COMBINED MICROPHONE AND SUPPORT UNIT (http://www.google.com/patents?id=m8NxAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D161891 Filed: Jun 19, 1950

CONTROL SYSTEM (http://www.google.com/patents?id=SXhjAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2802116 Filed: Sep 13, 1954

REMOTE SOUND SYSTEM MONITOR CIRCUIT (http://www.google.com/patents?id=8hpYAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3161731 Filed: Oct 16, 1962

HORN-LOADED (http://www.google.com/patents?id=DFhrAAAAEBAJ&pg=PA1968&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007#PPA1968,M1)LOUDSPEAKER (http://www.google.com/patents?id=DFhrAAAAEBAJ&pg=PA1968&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007#PPA1968,M1)
Patent number: 3432002 Filed: May 1, 1967

VOLTAGE-HOLDING CIRCUIT AND METHOD (http://www.google.com/patents?id=ZsFaAAAAEBAJ&printsec=abstract&zoom=4&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007#PPA3,M1)
Patent number: 3579129 Filed: Apr 25, 1969

SPEAKER DEVICE FOR SOUND REPRODUCTION IN LIQUID MEDIUM (http://www.google.com/patents?id=3Uc4AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3670299 Filed: Mar 25, 1970

PROTECTED POWER SUPPLY (http://www.google.com/patents?id=mkc4AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007&jtp=1)
Patent number: 3670232 Filed: Nov 9, 1970

ELECTRICAL ADJUSTMENT OF TIME- CONSTANT APPARATUS (http://www.google.com/patents?id=_KwtAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3660690 Filed: Nov 9, 1970

DIRECTIONAL LOUDSPEAKER SYSTEM (http://www.google.com/patents?id=V2IvAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3722616 Filed: Dec 14, 1970

HERMETIC TRANSFORMER (http://www.google.com/patents?id=xkc4AAAAEBAJ&pg=PA1&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007#PPP1,M1)
Patent number: 3670276 Filed: Feb 11, 1971

METHOD OF SOUND TRANSDUCER CONSTRUCTION (http://www.google.com/patents?id=gEwsAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3792526 Filed: Apr 21, 1971

CONDENSER MICROPHONE PREAMPLIFIER (http://www.google.com/patents?id=qYA3AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3913024 Filed: Aug 14, 1974

Heat dissipating device for loudspeaker voice coil (http://www.google.com/patents?id=MTgyAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3991286 Filed Jun 2, 1975

Method for aligning loudspeaker diaphragm and voice coil assembly (http://www.google.com/patents?id=Ibs2AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3967367 Filed: Oct 14, 1975

Protective circuit utilizing multilevel power supply output (http://www.google.com/patents?id=ZSosAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3987342 Filed: Nov 24, 1975

Continued

[moldyoldy]

Loudspeaker (http://www.google.com/patents?id=Vts7AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D248647 Filed: Apr 14, 1976

Loudspeaker (http://www.google.com/patents?id=W9E8AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D250586 Filed: Apr 15, 1976

Acoustical transformer for horn-type loudspeaker (http://www.google.com/patents?id=NF07AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4050541 Filed: Apr 21, 1976

Loudspeaker (http://www.google.com/patents?id=cXg8AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D249941 Filed: Sep 17, 1976

Acoustical transformer for coupling sound waves from the diaphragm to the throat of a horn (http://www.google.com/patents?id=XUY8AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D249509 Filed: Sep 23, 1976

Parallel power amplifier circuits (http://www.google.com/patents?id=0CEvAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4081757 Filed: Nov 19, 1976

Electronic filter circuit (http://www.google.com/patents?id=cPgqAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4078215 Filed: Nov 26, 1976

Modular printed circuit board assembly having cooling means incorporated therein (http://www.google.com/patents?id=O841AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4122508 Filed: Sep 6, 1977

Two-section exponential acoustical horn (http://www.google.com/patents?id=rC0rAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4176731 Filed: Nov 21, 1977

Method and apparatus for testing and evaluating loudspeaker performance (http://www.google.com/patents?id=EecxAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4130023 Filed: Dec 27, 1977

Adjustably positioned phasing plug (http://www.google.com/patents?id=bcowAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4180710 Filed: Aug 24, 1978

Input decoupling circuit for transistor differential amplifier (http://www.google.com/patents?id=7s4TAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4180780 Filed: Oct 2, 1978

Loudspeaker horn (http://www.google.com/patents?id=RUI6AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4187926 Filed: Dec 8, 1978

Loudspeaker overload protection circuit (http://www.google.com/patents?id=h8wBAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4296278 Filed: Jan 5, 1979

Acoustical transformer for compression-type loudspeaker with an annular diaphragm (http://www.google.com/patents?id=PVM7AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4325456 Filed: Oct 10, 1980

Network for use with piezoceramic transducer (http://www.google.com/patents?id=mns-AAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4481663 Filed: May 16, 1983

Power amplifier with current limiting means (http://www.google.com/patents?id=JAIdAAAAEBAJ&dq=inassignee:altec&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5029299 Filed: May 9, 1990

[moldyoldy]

Here’s a list of LMCo / JBL / Lansing Sound product patents (doesn’t include Harman International). The first 2 are somewhat problematic, as they are issued to the inventors, and not assigned to JBL. The first is Blackburn’s radial phase plug, and the second is Richard Ranger’s Paragon. Nevertheless, they were Lansing products, so I included them. There may be others like this, I saw another Ranger patent for a theater system, but passed it by, not knowing.

If you have an item with a patent label, please add those numbers too, if they aren’t yet listed.

LOUDSPEAKER (http://www.google.com/patents?id=LfZNAAAAEBAJ&dq=loudspeaker+ininventor:blackburn&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2183528
Filing date: Aug 14, 1937

STEREOPHONIC SOUND DISTRIBUTOR (http://www.google.com/patents?id=xGhhAAAAEBAJ&dq=speaker+ininventor:Ranger&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 3065816
Filing date: Mar 10, 1958

Loudspeaker assembly (http://www.google.com/patents?id=gVw7AAAAEBAJ&dq=inassignee:lansing&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D247490
Filing date: Dec 15, 1975

Electrical connector (http://www.google.com/patents?id=-nYTAAAAEBAJ&dq=inassignee:lansing&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4039243
Filing date: Sep 7, 1976

Diaphragm suspension construction (http://www.google.com/patents?id=FLc5AAAAEBAJ&dq=inassignee:lansing&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4324312
Filing date: Oct 1, 1979

Loudspeaker magnet housing (http://www.google.com/patents?id=EzwqAAAAEBAJ&dq=inassignee:lansing&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D266420
Filing date: Oct 9, 1979

Loudspeaker horn (http://www.google.com/patents?id=0BkzAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4308932
Filing date: May 6, 1980

Loudspeaker magnet housing (http://www.google.com/patents?id=cVQqAAAAEBAJ&dq=inassignee:lansing&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D267644
Filing date: Aug 3, 1981

Defined coverage loudspeaker horn (http://www.google.com/patents?id=H7A7AAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4580655
Filing date: Oct 5, 1983

Acoustic diaphragm (http://www.google.com/patents?id=2pkvAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 4655316
Filing date: Mar 13, 1985

Speaker mounting assembly (http://www.google.com/patents?id=MJUnAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5143339
Filing date: Mar 1, 1991

Phasing plug for compression driver (http://www.google.com/patents?id=_igkAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5117462
Filing date: Mar 20, 1991

Arrangement to correct the linear and nonlinear transfer behavior or electro-acoustical transducers (http://www.google.com/patents?id=Ze4dAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5438625
Filing date: Apr 9, 1992

Temperature/environment-resistant transducer suspension (http://www.google.com/patents?id=02EbAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5455396
Filing date: Oct 21, 1994

Low TCR wire in high power audio coils (http://www.google.com/patents?id=CQQiAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5664023
Filing date: Nov 14, 1994

Loudspeaker thermal management structure (http://www.google.com/patents?id=KJIjAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5533132
Filing date: Jan 23, 1995

Front-locking swivel ball loudspeaker mount (http://www.google.com/patents?id=JNEaAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5704578
Filing date: Nov 3, 1995

Loudspeaker enclosure (http://www.google.com/patents?id=KzMZAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D394263
Filing date: Mar 14, 1997

Inductive braking in a dual coil speaker driver unit (http://www.google.com/patents?id=fl0ZAAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 5828767
Filing date: Sep 22, 1997

Vehicle sound system (http://www.google.com/patents?id=UMV3AAAAEBAJ&dq=inassignee:jbl&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 6990208
Filing date: Mar 8, 2000

[Robh3606]

What a great idea:thmbsup:

Thanks for putting this together. I wonder if we can add the ones referenced in the 60th Anniversary Book. Do you think they are available??

Rob:)

[moldyoldy]

...I wonder if we can add the ones referenced in the 60th Anniversary Book. Do you think they are available??

Rob:)

It's all available Rob, just may take us a little time to round up the strays. Having not seen the book yet :o:, just check them against the list, and add whatever you can for those not listed (anybody).

Being less familiar with JBL products, I’m gonna need help here. I used the same methods in finding them, and got all there was, but have no idea how many if any are missing. Perhaps someone good with recent products could enter Harman in the assignee search slot, and sort out what should be included from those results.

University had a few neat patents as well, and of course there are some WE and Bell patents that ended up in LH production. Let's have some input on feelings for yea/nay on including them and others of related nature. Might be better to gather all maybes and sort it out later.:hmm:

Time to hear from the masses, my typin' finger's sore! :)

(Move over, Silver Surfer!)

[moldyoldy]

Q What single piece of technology is shared by our preferred loudspeakers nearly across the board, and used from the earliest till today?

Put your pencils down.

If you wrote edgewound, or 'an indeterminant variant thereof', advance three spaces.

I made a brief pass at the origin of the edgewound coil (implies flat wire). For voice coils specifically, you've gotta read a lot of them to find that one, which I've not yet pinned down. In the meantime, I made note of one that dates the technology to '25 so far;

METHOD AND APPARATUS FOR MAKING EDGEWOUND COILS (http://www.google.com/patents?id=HSF5AAAAEBAJ&dq=coil+flat+edge&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=b&as_minm_is=1&as_miny_is=1918&as_maxm_is=1&as_maxy_is=1928)
Patent number: 1630912
Filing date: Dec 11, 1925
Issue date: May 31, 1927
Inventor: GEORGE H. WHITTINGHAM
Assignee: MONITOR CONTROLLER COMPANY

OK, so it's for rheostat coils...

GMC had a similar machine in '25, only it made bearings (bush type).

Flat wire in general before 1930 musta been a big thing, based on the hits. Lots of resistance heaters. The kind you plugged in for heat before there were plugins...
...or stared at on long, cold winter nights while pondering inventions...

[pocketchange]

In Australia just patented (looks like it anyway) the throat design for the 2380A horn which has been around for how long, 10 or so years? :D No fooling, #7044265
:blink:

[Hoerninger]

In Australia just patented (looks like it anyway) the throat design for the 2380A horn which has been around for how long, 10 or so years? :D No fooling, #7044265
:blink:
FYI - prior art?
D.B.Keele (Electro Voice):
http://www.google.com/patents?vid=USPAT4071112
(Fig.5)

Then I found this:
Inventors: John D. Meyer, Alejandro Antonio Garcia Rubio
Assignee: Meyer Sound Laboratories Incorporated (www.google.com/patents?id=IaEXAAAAEBAJ&printsec=abstract&zoom=4)
___________
Peter



PS:
Just got in mind this:
Wheel patented in Australia (http://www.newscientist.com/article.ns?id=dn965)
"The innovation patent is designed to provide a quick, easy and cheap alternative to a traditional patent for small businesses. It replaces the petty patent in Australia and is even easier to process. Applications for innovation patents can even be made online."
Australian Application Number 2001100012 (http://www.ipaustralia.gov.au/patents/search_index.shtml)

[moldyoldy]

I'm sure glad others find this stuff of interest, the thread was starting to look like a blog, which sure wasn't my intent.

I just realized my previous posting of intent to compile the thread in the future may cause some to refrain from posting. It shouldn't, as I only want to gather and assemble the pertinent patents into a useful and accurate list. The more people contribute, the more likely we'll end up with a complete list.

Names, faces, and interim prattle will be excluded to protect the innocent. ;)

[Steve Schell]

Moldyoldy, I applaud your efforts in establishing this thread. Aside from the practical aspects for inventors, patent surfing can be a great deal of fun for those interested in technology and the history of same. I have spent many happy hours reading some of the thousands of old speaker patents, and my brother has done the same in his realm of interest, mechanical calculators.

Aside from Dr. Blackburn's radial slit phasing plug patent, I have not found any others directly related to Lansing Manufacturing Company. There is one patent mentioned in the August, 1943 Altec Lansing catalog. They state that the Iconic (same as the earlier Lansing Iconic) is manufactured under U.S. Patent #2,143,175, as well as various (unstated) patents owned or controlled by Western Electric Company. Here is a link to the Altec catalog page:

http://www.lansingheritage.org/images/altec/catalogs/1943/page02.jpg

Here is a link to the patent:

http://www.google.com/patents?id=EgECAAAAEBAJ&dq=2143175

This patent issued to Samuel A. Waite describes a two way speaker with bass reflex low frequency section and (in one embodiment) a multicellular horn high frequency section. Mr. Waite's patent was applied for in October 1937, shortly after the introduction of the Lansing Iconic. We may never know whether Mr. Waite had any relation to Lansing Mfg. Co., or if he simply applied for a patent on the concept of the Iconic and later successfully negotiated compensation from Altec Lansing.

Mr. Ercell B. Harrison was the brilliant transformer engineer who pioneered the design of wide bandwidth, low phase shift audio transformers. John Hilliard related in one of his articles that Harrison designed and built new transformers to upgrade the audio equipment at MGM studios in 1937, while in the employ of Lansing Mfg. Co. He is also credited with the design of the later 20/20 series transformers built by Altec's Peerless division. I have not found any patents by Harrison related to his transformer breakthroughs, though I did find this one from 1926 (!) related to transducer and horn design:

http://www.google.com/patents?id=ZQJEAAAAEBAJ&dq=1776902

It appears that Harrison was into speaker design about as early as Jim Lansing, so they shared some common interests. Mr. Harrison is pictured standing directly to Jim Lansing's right in the employee picture that we think was probably taken in early 1942:

http://www.audioheritage.org/intro.htm

[Hoerninger]

When reading thoroughly patent 5,925,856 by John D. Meyer et al.(Meyer Sound, Cal.) you get the idea of a modern throat design.
____________
Peter

[moldyoldy]

Here’s the Bell patent embodied in WE 633 and Altec 632 and 633 “Saltshaker” mics

ACOUSTIC DEVICE (http://www.google.com/patents?id=8NhhAAAAEBAJ&dq=patent:2131593&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)

Patent number: 2131593
Filing date: Sep 9, 1936
Issue date: Sep 1938
Inventor: Robert N. Marshall
Assignee: Bell Telephone Laboratories

Saltshaker ornamental patent

DESIGN FOR A TELEPHONE TRANSMITTER (http://www.google.com/patents?id=VThsAAAAEBAJ&dq=ininventor:Robert+ininventor:Marshall&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=b&as_minm_is=1&as_miny_is=1933&as_maxm_is=1&as_maxy_is=1962)

Patent number: D101816
Filing date: Sep 9, 1936
Issue date: Nov 1936
Inventor: Robert N. Marshall
Assignee: Bell Telephone Laboratories


I’ve been looking for the next one for a long time. Also by Bell/Marshall. The manufacture and assembly detail for the moving coil diaphragm for the above microphone. I believe this also to be the grandaddy recipe for Altecs' long-running dynamic microphone line, as well as the assemblies used in the 3000 series tweeter horns. Originally made of Duralum, replaced with Mylar when it appeared on the scene. Altec mic brochures tout their “golden mylar” diaphragms for years, but I’ve also seen blue versions, and silver too. Voice coils (19mm) may vary per application (unverified), but the diaphragms in all iterations appear to be formed on the same die. The edgewound coil has no former, being attached directly to the diaphragm as detailed in the patent. Adhesive bonding throughout. The gap is 0.66mm, and the 'fram would blow away from a bee's breath. Far too delicate and precise for practical hand assembly, the following invention made it all possible.

AFAIK, Bill Hayes offers the only service for these, and last I heard was debating whether to make any more or not. After reading the patent process, I can see the difference between production conditions, and service, where where one-off jobs take 5+ times the effort. Can't make 'em up in advance unless you had the bodies to put 'em in. I'd looove to see the tooling...

METHOD OF AND MEANS FOR ASSEMBLING ACOUSTIC DIAPHRAGMS (http://www.google.com/patents?id=nVdbAAAAEBAJ&dq=patent:2094043)

Patent number: 2094043
Filing date: Nov 15, 1935
Issue date: Nov 1937
Inventor: Robert N. Marshall
Assignee: Bell Telephone Laboratories


Top image, l-r; drawing excerpt from patent, assembled Altec 3000 HF unit, top plate less 'fram, magnet structure with coil for mic use clipped, but left in assy. Indicates assemblies for 3000 tweeters were definitely robbed from microphone parts stock instead of being purpose-built.

Lower image from WE brochure, borrowed from James Steele's wonderful Vintage Broadcast Microphone site.

[moldyoldy]

Another one from Bell, for the horn embodied in the WE and Altec 32x bent horns. Various angled throat adapters may have been derived here as well.

ACOUSTIC DEVICE (http://www.google.com/patents?id=Arl4AAAAEBAJ&dq=horn+inassignee:bell&as_drrb_ap=b&as_minm_ap=1&as_miny_ap=1927&as_maxm_ap=1&as_maxy_ap=1939&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 1996743
Filing date: Apr 25, 1934
Issue date: Apr 1935
Inventor: D. G. BLATTNER
Assignee: Bell Telephone Laboratories

[boputnam]

Moldyoldy, I applaud your efforts in establishing this thread. Me too.

As posted elsewhere...

-----

That Google Patent Search is amazing. I search patents all the time, but have always stuck to the USPTO website. :o: I pay $3 a copy from them, when I need hardcopy. I've been waiting days for turnaround on some new requests, and found them - BINGO - with that Google Patent search. Thanks for the tip, dood. :thmbsup:

[Zilch]

Google accomplishes in a matter of months what the USPTO hasn't been able to in over a century?

How can that be?

[And we're paying these guys, right? :p ]

[boputnam]

Google accomplishes in a matter of months what the USPTO hasn't been able to in over a century?Yea...

:offtopic:, but...

A collegue and I were marvelling at the potential Google is making possible. As example, notwithstanding the issues of copyright, if Google do manage to archive libraries of books/research, the positive impact is enormous.

My thesis work, as example, consumed over a years-time on literature research alone - this done in-parallel to the lab work. The literature research was done by meticulous combing the references of each scientific article, trudging back to Library for another round of copying/reading and/or requesting copies of work from scientific journals. Repeat. Repeat, again. Turnaround was weeks in length - often articles would finally arrive only to have either been made redundant or fundamental by other found literature. Arduous, inefficient and fraught with the nasty problem of not knowing of some critically relevant work. That part of research will be vastly smartened-up by this, accelerating the whole process. Incredibly promising, and, problematic (from an IP perspective).

[moldyoldy]

Kinda puts the potential for exponential expansion in a whole new light, doesn't it?

I've been wondering about the potential of applying the technology to our image library...:hmm:

[boputnam]

Kinda puts the potential for exponential expansion in a whole new light, doesn't it?Yea, exactly.


I've been wondering about the potential of applying the technology to our image library...:hmm:Yea, EXACTLY!!

[Hoerninger]

The literature research was done by meticulous combing the references of each scientific article, trudging back to Library for another round of copying/reading and/or requesting copies of work from scientific journals. Repeat. Repeat, again.
Bo, axactly - :(
this way I once started to collect horn literature
[and no one else seemed to share an interest.]

Yet by the internet alone there has been such an increase in available and new literature, it is a joy. Yes, sort of exponential expansion!
[And there are others interested too.]

Moldyoldy, patent search by Google is a sort of refinement now. Thank you for the hint! I had used http://www.pat2pdf.org/ so far, but there is no search function.
____________
Peter

[moldyoldy]

Another useful tip;

Once you've located an item of interest, do a side search on the inventor. Often, other aspects of the item of interest will be revealed. This is how I finally found the (above) diaphragm assembly technique I'd searched for so long.

[kingjames]

What an excellent effort,and very interesting indeed. I will be reading quite a while on this stuff as it is a lot of fun to search this stuff out.

[moldyoldy]

Yea...

:offtopic:, but...

A collegue and I were marvelling at the potential Google is making possible. As example, notwithstanding the issues of copyright, if Google do manage to archive libraries of books/research, the positive impact is enormous....

(warranted OT...read on...)

Sometimes I'm reminded that when I had hair, it was blond...don't know how your comment blew right by without notice, Bo. In reply, your wish has not only been researched, but put into practice;

Google Scholar (http://scholar.google.com/intl/en/scholar/about.html) provides a simple way to broadly search for scholarly literature. From one place, you can search across many disciplines and sources: peer-reviewed papers, theses, books, abstracts and articles, from academic publishers, professional societies, preprint repositories, universities and other scholarly organizations.

Google's mission is to organize the world's information and make it universally accessible and useful. Facilitating library access to scholarly texts brings us one step closer to this goal. We're thankful to the libraries and librarians who make it possible. Support for Libraries (http://scholar.google.com/intl/en/scholar/libraries.html)


Simply put, it's freakin; awesome! Copyrights are protected. Like an AES search, you get a 'taste', to see if it's what you want. Then, you are given the best options to get the rest. If it's in your local library, you'll know. Apprears to be mutually beneficial to all concerns. This old dog is sure learning some new tricks, anyway. :bouncy:

[moldyoldy]

(Edited) Another Altec microphone, the "lipstick" M-20x, in two patents, one by Wm. Moreland, assigned to George Carrington, the other by George Carrington, unassigned. Anybody know "the rest of the story"?

CONDENSER MICROPHONE STRUCTURE (http://www.google.com/patents?hl=en&lr=&vid=USPAT2567889&id=Lz9iAAAAEBAJ&oi=fnd&dq=carrington+microphone)
Patent number: 2567889
Filing date: Feb 24, 1950
Issue date: Sep 1951
Inventor: William J. Moreland
Assignee: George L Carrington

MICROPHONE SOUND PASSAGE STRUCTURE (http://www.google.com/patents?id=IT9iAAAAEBAJ&dq=patent:2567875&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2567875
Filing date: Feb 24, 1950
Issue date: Sep 1951
Inventor: George L. Carrington
No Assignee

[moldyoldy]

Another “team” mic design, from Robert Marshall and Wm. Harry of Bell Labs, embodied in the WE and Altec 639x “Birdcage” mic.

This one was tricky to pin down due to the (as yet unexplained) time span between patent filings. I found the design patent first, so I knew there had to be more, but it took several external references to put it together. Marshall and Harry were still testing and writing about it well into the 40s.

Guess it just stands to reason that once you've found the easy ones, the rest will be harder. Wish I had one of each item NIB with the patent numbers on it, but I suppose if I did, I'd be slurping rum on some beach, instead of sleuthing patents and sippin' 'shine...

ACOUSTIC DEVICE (http://www.google.com/patents?id=rZFbAAAAEBAJ&dq=microphone+ininventor:harry+inassignee:bell&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: 2293258
Filing date: Nov 24, 1939
Issue date: Aug 18, 1942
Inventor: William R. Harry
Assignee: Bell Telephone Laboratories


DESIGN FOR A TELEPHONE TRANSMITTER (http://www.google.com/patents?id=AGoCAAAAEBAJ&dq=ininventor:marshall+inassignee:bell&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)
Patent number: D112756
Filing date: Jul 1, 1933
Issue date: Dec 27, 1938
Inventor: Robert N. Marshall
Assignee: Bell Telephone Laboratories
_______________________________________

Note gleaned along the way;

Effective 10/01/1949, WE discontinued Sound Products Division, including production and service of the following models, and transferred all related engineering info, existing inventory, and parts stock for same to Altec Lansing for continued product support;

633 type microphone
639 type microphone
728B
755
757
109 type reproducer group
9A type reproducers
9B type reproducers

Distribution to be continued through Graybar Electric as before.

(from WE ad in Nov. 1949 issue of Audio Engineering)

[moldyoldy]

Correction to post #16;

Substitute 31x for 32x embodiment

Correction to post 26;

Substitute M-21xx for M-20x

[Thom]

Awesome, cheaper than bowling, model railroading etc. Extremely interested in the flat wire origins. It's benefit in rheostats is so obvious it would be interesting to find out if that had anything at all to do with its use in vc's. The benefits obviously are not for the same reason.

[moldyoldy]

...The benefits obviously are not for the same reason.

Perhaps, there are certainly applications where the beef of a heavy roundwire coil is needed. Edgewound coils have a "flatter" outer profile with the valleys between turns considerably reduced. For rheostats, that means smoother operation and finer adjustment, but reduced contact area unless the wiper contact is enlarged to compensate. For pots that don't handle much current, it's a win/win. VCs benefit from increased turns in a given length, and the flatter profile allows more coil in near proximity of the poles, = greater Bl.

Have you noticed the lack of any mention of 'skin theory' when the author is trying to sell his idea to someone that understands the subject? ;)

"Awesome, cheaper than bowling, model railroading etc."

Mom would say, "And it's good for you too!"

[Thom]

Actually really heavy motors transformers etc use square most of the time and the lead from the buss may be ribbons stacked to give the flexibility a heavy bar doesn't have. All I was saying (I love your thread and don't wish to hijack it) was that the reasoning behind using ribbon in a vc and using it in a rheostat are different so while one may have come from the other, it may not have. I guess if ribbon wire was already a commodity there may not even be a patent for using it in a vc, but I'd sure like to know who's idea it was and if the original reason was the reason that they have sold all these years.

[moldyoldy]

Found it! The patent specifically for edgewound voice coils in loudspeakers, not only for flat wire, but triangular wire as well;

OSCILLATING COIL FOR ELECTRODYNAMIC LOUDSPEAKERS (http://www.google.com/patents?id=QDpYAAAAEBAJ&dq=voice+coil+loudspeaker+wound&as_drrb_ap=b&as_minm_ap=1&as_miny_ap=1895&as_maxm_ap=1&as_maxy_ap=1933&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)

Patent number: 1935404
Filing date: Feb 19, 1932
Issue date: Nov 1933
Inventor: Joachim Leopold
Assignee: Telefunken Gesellschaft fur Drahtlose Telegraphic

Only a few months later, Wente refers to the use of an edgewound voice coil in a familiar Bell patent;

ACOUSTIC DEVICE (http://www.google.com/patents?id=wENMAAAAEBAJ&dq=ininventor:wente&as_drrb_ap=b&as_minm_ap=1&as_miny_ap=1930&as_maxm_ap=1&as_maxy_ap=1934&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)

Patent number: 1930915
Filing date: Jul 13, 1932
Issue date: Oct 1933
Inventor: Edward C. Wente
Assignee: Bell Laboratories

Hmmmmm...:hmm:

[Thom]

I'm impressed. I don't even have time to completely read what you've found. Let alone, research it. I wonder if anyone produced any speakers with no bobbin. I bet someone has patented hex wire at some point as it would allow the most conductor in a multilayer. I've got to go to the start of this thread and try to follow your step by step.

How do I mark a thread so I don't have to search for it when I want it?

[moldyoldy]

This patent is for the Altec Acousta-Voicing Process. Specific embodiment as yet undetermined, could span several product models of equalizers and related items.

SOUND-IMPROVING MEANS AND METHOD (http://www.google.com/patents?id=KX4CAAAAEBAJ&dq=patent:3624298&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2007&as_maxm_ap=1&as_maxy_ap=2007&as_drrb_is=q&as_minm_is=1&as_miny_is=2007&as_maxm_is=1&as_maxy_is=2007)

Patent number: 3624298
Filing date: Mar 5, 1969
Issue date: May 1972
Inventors: Arthur C Davis, Donald B Davis, Tustin; James J Noble
Assignee: LTV Ling Altec

[Steve Schell]

There have been voice coils without supporting bobbins. L.G. Bostwick's 596A tweeter used an unsupported edgewound aluminum coil which was glued directly to the aluminum diaphragm. Smith and Selsted used (I think) a two layer round wire aluminum voice coil similarly glued to an aluminum diaphragm. In both these instances the goal was to minimize mass to extend the high frequency response.

The Western Electric 555W compression driver used an edgewound aluminum voice coil, and was in large scale production by 1926 or 1927. I believe this was the first use of a ribbon wire voice coil in a loudspeaker. The U.S. Patents #1,707,544 (A.L. Thuras) and 1,707,545 (E.C. Wente) describe the driver in detail. The particulars of the voice coil design and construction are discussed in depth in Mr. Thuras' patent.