Telephone Patents

© Brooke Clarke, N6GCE 2003 - 2022



Magneto Era
1883 Samuel Morse sends signals over wires
1876 Bell Invents the Telephone
Magneto Ringing Generator
Balance (loading & Induction Coils)
Pole Changers
1880 Handset
1889 Carbon Mike
1893 Better (Long Pole) Receivers
1891 Dial System working
1892 Carbon Mike
1893 Bell's first patent runs out
1894 Transformer
Mounts
Bakelite
Dials
Design Patents
USPTO Class Numbers
Related
Links

10 Feb 2005 - have replaced all the patent number links with stable URLs.
5 July 2017 - added a section based on the book: Electroacuustics: The Analysis of Transduction, and its Historic Background,
Published by the American Institute of Physics for the Acoustical Society of America.  Frederick V. Hunt, 1954, 1982, ISBN: 0-88318-401-X

pg 16 - There is a mistake in that the book says the most important contribution of Joseph Henry was to sectionalize the electromagnet coil winding into sections.  But that's far from the case.  The KEY thing Henry did was to insulate the wire he used.  All prior work with electromagnets used bare wire.  Henry used his wife's spinning wheel to cover "Bell" wire with silk.  Note "Bell" wire was not the name for electrical wire used to ring doorbells as it is so named today, but rather it was wire that was routed using pulleys mechanically terminated in bells that rang when the master pulled a cord, hence "bell wire".

pg 23 - 174465 Telegraphy, A. G. Bell March 7, 1876   379/167.01; 178/48 -

pg 33 - 186787 Electric Telegraphy A. G. Bell Jan 30, 1877   379/167.01; 379/387.01; 381/177 - includes use of permanent magnet for receiver

pg 34 - Francis Blake carbon transmitters with Berliner induction coil competes with Edison carbon mike
250126 Speaking-telephone, Francis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/179; 381/347 - had a stability problem
250127 Speaking-telephone, Feancis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/179 - had a stability problem
250128 Speaking-telephone, Feancis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/178 - had a stability problem

225790 Microphone, Emile Berliner, Mar 23, 1880, 381/354; 381/180 - pendulous weight = not at all practical, no induction coil
234744 Microphone, Emile Berliner, Nov 23, 1880, 381/178 - couples microphone to induction coil to transform impedance, can be used by Bel Tel with Blake carbon mike patents.
463569 Combined Telegraph and Telephone, Emile Berliner, Filed: Jun 4, 1877 (14 year delay) Pub: Nov 17, 1891, 381/178  -

Magneto Era

YouTube: PhoneCoInc:

1833 Samuel Morse sends signals over wires

For about 40 years the telegraph was THE way to send a message quickly. Bell was working on a way to allow multiple messages to be sent in parallel over a single wire by using different audio frequencies for each message.  Today it would be called FDMA, Frequency Division Multiple Access.  In the process he realized that voice could be sent over a wire.  This required the invention of the microphone and the invention of the speaker.  The device in the bell patent works as both a microphone and a speaker.

See the Leclanché Battery web page for those and related patents.
See the Gamewell Fire Alarm Street Box for more on Pen Registers.

Related Telegraph Patent

166095  Electrical Telegraph for Transmitting Musical Tones, Elisha Gray, July 27, 1875 178/47
Note that the Gray patent title is Electrical Telegraph for Transmitting Musical Tones not some new term to describe telephony.  Gray thought he had a patent on an improvement to telegraphy.  The single class number is 178/47 which is for Telegraphy/Harmonic or reed.

1876 Bell Invents the Telephone

Magneto Era @1:48@ 2:33 The Gallows Telephone, @3:11 Liquid Transmitter (I have not found a patent for the liquid transmitter), @4:38 Centennial Transmitter, @5:01 Centennial Iron Box Receiver, @5:14 Box Telephone & Watson's mechanical thumper (incoming call noise), @6:20 Butterstamp (prior to long pole) Design,


First generation Local Battery operation with hand crank generator signaling.
174465 Telegraphy, A. G. Bell March 7, 1876   379/167.01; 178/48 - sending sounds over wire "The most valuable patent ever issued"
Included in this patent are the Gallows and Liquid phones. Both are combined dynamic microphone/earphone types.
The primary class number 379/167.01 is for Telephonic Communications/ Private (e.g., house or intercom) or Single Line System.
The secondary class number 178/48 is for Telegraphy/Harmonic or reed/Recorders and receivers

174465
                      Telegraphy, A. G. Bell March 7, 1876
Gallows
                      Phone Mouthpiece
Side
                      (Gallows) view
sheet 2 of patent figures
Fig 6: the 3 "A" reeds vibrate in unison, &Etc.
Fig 7: Voice not tones
Gallows Phone Mouthpiece
Side (Gallows) view
Is patent 174465 also the first patent for a speaker - earphone type device?  yes.
Note that the coil and terminals looks just like those used in telegraphic sounders.
For more on this phone, see my phones web page.

Remember that at the time the patent titles were commonly the same for the same patent class.  For example out of over 400 patents related to the stock ticker machines the vast majority of them are titled "Printing Telegraph".  Since patent class 379 to telephone related inventions did not exist then the only class that mase sense with 178 for Telegraph Equipment.   So although it looks strange today to see "Telegraph" as the title on a patent for the telephone, at the time it was about the only choice.

186787 Electric
                  Telegraphy A. G. Bell Jan 30, 1877

186787 Electric Telegraphy A. G. Bell Jan 30, 1877   379/167.01; 379/387.01; 381/177
In 201488 it says the rod in this patent can be a magnet. 
That would make this the first sound powered telephone.
492789 Speaking Telegraph "Liquid
                  Transmitter", T.A. Edison, 1893-03-07
492789 Speaking Telegraph "Liquid Transmitter", T.A. Edison, 1893-03-07,

Liquid Transmitter Photos © Jeffrey R. Brooks

Fig 1
492789 Speaking Telegraph "Liquid
                  Transmitter", T.A. Edison, 1893-03-07 © Jeffrey
                  R. Brooks
Fig 2
492789
                          Speaking Telegraph "Liquid
                          Transmitter", T.A. Edison, 1893-03-07 ©
                          Jeffrey R. Brooks
Fig 3
492789
                          Speaking Telegraph "Liquid
                          Transmitter", T.A. Edison, 1893-03-07 ©
                          Jeffrey R. Brooks


Other Patents

199141 Telephone, E. Berliner, Jan. 15, 1878 379/167.01; 379/391; 381/178
201488 Speaking Telephone, A.G. Bell, March 19, 1878 381/163 ; 335/231; 336/110; 336/211; 381/419 -
     this is the oldest patent in class 336/110 Inductor Devices/using a permanent magnet
     The main idea is to close the magnetic path so that there is only the gap to the diaphragm.

203013 Speaking-Telegraph, T.A. Edison, April 30, 1878 381/111; 381/179
203016  Speaking-Telegraph, T.A. Edison, April 30, 1878 379/373.01
210886 Polarized Armature for Electric Bells, T. A. Watson, Dec. 17, 1878 340/397.5

Magneto Ringing Generator

@8:30 Magneto Era: Signaling, @8:54 Leclanché Battery, @9:30 Williams Coffin (Wood, wall mount, bells, two long poles, crank on front, magneto or bell switch & Lightening protection), @9:46 Gravity (Hook Switch for magneto-Bell)


202495 Telephone Call-Signal apparatus, T. A.
                  Watson, April 16, 1878
202495 Telephone Call-Signal apparatus, T. A. Watson, April 16, 1878 379/373.01; 74/47 - Magneto & ringer

This was the start of magneto signaling but it had some problems.
1. The switch needs to be set to "Bell" (position 1) after all calls so someone can call you.  If you forget all is lost.
2. Cranking the magneto at a 1:1 ratio requires a LOT of work.
217849 magneto-electric call apparatus, George L.
                  Anders, Jul 29, 1879
217849 magneto-electric call apparatus, George L. Anders, Jul 29, 1879, 310/75B - magneto generator (4 horseshoe magnets)
Uses a special pulley system to gear up the magneto solving problem 2 above.

223132 Automatic Electric-switch for Telephones, E.T. Greenfield, 1879-12-30, - switch in end of long pole receiver. 
For switching the talk circuit, I don't think for the bell circuit.

330064 Gravity Telephone Switch, C. E. Scribner, Western Electric, 1885-11-10, 379/424
This is a follow on patent to 271280 for a secrecy switch.

to replace magneto-bell switch have not found patent by Hilborne Roousvelt for his gravity switch.
273714 Magneto-electric signaling apparatus, T.A.
                  Edison, 1883-03-13
273714 Magneto-electric signaling apparatus, T.A. Edison, 1883-03-13, -
The magneto is automatically switched into and out of the circuit by means of turning the hand crank.
has what became common gearing (c & d) of hand crank to magneto.
This solves both of the problems with the Watson patent above.


Unknown Magneto generator, missing the magnets.  Where would they go?  Is red bar supposed to be a magnet?
66A stamped on top of cast iron pole
with a 6 on either side of the hole at the top
Note only one hole at top of this pole.
Telephone Magneto
                  Generator

Telephone Magneto
                  Generator
3 holes on top of front pole.
Output is between case and shaft at center.
Telephone Magneto
                  Generator

Balance (loading & Induction Coils)

The early telephone lines consisted of a single wire (to save money) and a ground return.  But the mutual inductance between wires caused crosstalk (Wiki).  As the number of wires and active circuits grew this became a large problem.  Also see: Inductors: 88mH, Induction Coil
232788 Thomas A. Watson, Sep 28, 1880, 379/240 - periodically a transformer is used to interchange the ground and aerial side of the circuit.  The idea of running a separate ground wire near the aerial wire to cancel the crosstalk was know but viewed as too expensive.

This lead to the induction coil and balanced cables.
705936 Loaded electric circuit, John C Lee, Edwin H Colpitts, AT&T, 1902-07-29, -
720023 Electric cable, Roderic F Hall, WE, 1903-02-10, 174/27; 174/116-
792248 Induction-coil, George A Campbell, AT&T, 1905-06-13, 336/84C; 333/25; 336/84R; 336/69; 336/107; 379/387.01 -
980921 Loaded phantom-circuit, George A Campbell, Thomas Shaw, AT&T, 1911-01-10, -
1133750 Transformer, Thomas Shaw, AT&T, 1915-03-30, - Phantom Circuit
1174187 Loading-coil, Thomas Shaw, AT&T, 1916-03-07, - Duplex Phantom Circuit
1251651 Core for magnetic coils, Lloyd Espenschied, AT&T, 1918-01-01, -
1727971 Electrical cable, Ford Leroy Stearns, WE, 1929-09-10, 174/112; 156/55; 174/113R; 57/210; 156/56-

Pole Changers

Manual telephone exchanges used electric bells as a way to get someone's attention.  These required AC at about 10 Hertz (then called Cycles Per Second or CPS).
The "pole changer" was a device that converted a DC battery voltage into AC ringing voltage.

238263 Pole-Changer for Telephone-Exchanges, E.P. Warner (Western Electric Mfg Co), Mar 1, 1881, 361/246 
685887 Pole Changer, W.F. Warner (Warner Elec Co), Nov 5, 1901, 361/246 -
    RE12162 Pole Changer, W.F. Warner (Warner Elec Co), Oct 13, 1903, 361/246 -
   
Pole Changer (20 Hz Ring Generator) Patent
                  RE12162 Fig 1 redraws by Brooke Clarke x
photo from eBay seller jonincleve
   
1067527 Signaling System, C.A. Larson (Kellog Switchboard & Supply Co), Jul 15, 1913, 379/186
1330059 Pole Changer, H.D. Currier (Kellog Switchboard & Supply Co), Feb 10, 1920, 379/181; 340/328; 340/331; 340/333 -
1382745 Electrical Rectifier and Pole Changer, F. Schoenwolf (Kellog Switchboard & Supply Co), Jun 28, 1921, 363/34; 379/418

1879 to 1890 Attempts at dial systems

215837 Telephone Switch May 27, 1879, H.L. Rosevelt 379/426
222458 Automatic Telephone Exchange Dec 9, 1879 M D & T A Connolly and T J McTighe  379/195 - dial system that did/tn work
258626 Individual Signaling Aparatus for Telephone Systems May 30, 1882 C E Buell (US Tel Mfg Co) 340/825.41; 379/177; 379/302 - early try at dial phone
275296 Automatic Signaling Aparatus for Telephone Circuits Apr 3, 1883 T N Vail 379/302; 341/192 - try that did not work for dial phone

1880 Handset

224138  Electric-Speaking Telephone R. G. Brown Feb. 3, 1880 379/433.01
250126  Speaking Telephone, F. Blake Nov 29, 1881 381/179; 381/347
250127  Speaking Telephone, F. Blake Nov 29, 1881 381/179
250128  Speaking Telephone, F. Blake Nov 29, 1881 381/178
250129  Speaking Telephone, F. Blake Nov 29, 1881 381/178
Emile Berliner and his work improving the Blake transmitter

1889 Carbon Mike

Magneto Era @9:57 Edison Carbon Mike "Transmitter" (see 406567 below), @16:08 White Transmitter Design "White Solid Back" on most US candlesticks in 1920,

246512 Transmitter for Telephones, H. Hunnings, American Bell Telephone Co., Aug 30, 1881, 381/180 - carbon powder
250250 Telephone Transmitter, H. Hunnings, American Bell Telephone Co., Nov 29, 1881, 381/180 - carbon particles

250126 Speaking-telephone, Francis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/179; 381/347 - had a stability problem
250127 Speaking-telephone, Feancis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/179 - had a stability problem
250128 Speaking-telephone, Feancis Blake, sold to Bel Tel, Filed: Sep 15, 1881 Pub: Nov 29, 1881, 381/178 - had a stability problem

225790 Microphone, Emile Berliner, Mar 23, 1880, 381/354; 381/180 - pendulous weight = not at all practical, no induction coil
234744 Microphone, Emile Berliner, Nov 23, 1880, 381/178 - couples microphone to induction coil to transform impedance, can be used by Bel Tel with Blake carbon mike patents.
463569 Combined Telegraph and Telephone, Emile Berliner, Filed: Jun 4, 1877 (14 year delay) Pub: Nov 17, 1891, 381/178  -
406567  Telephone T. A. Edison July 9, 1889 381/180; 252/502 - uses carbon-granules.  When combined with the Induction Coil provides a lot of gain.
AGB's patent 174465 was for a combined dynamic microphone - earphone - speaker device.  But the granular carbon mike was the common microphone used through the 1950s for telephones, military radios, and many other microphone applications.  From 1950 to the present military radios use dynamic mikes.  Henry Hunnings patented a similar system in 1881 in the UK?
474230 Speaking-telepgraph, Thomas A Edison, WU Telegraph Co. Filed:Apr 27, 1877 Pub: May 3, 1892, 381/177 -
474231 Speaking Telegraph, Thomas A EdisonWU Telegraph Co., Filed:Apr 27, 1877 Pub: May 3, 1892, 381/179 -
474232 Speaking Telegraph, Thomas A EdisonWU Telegraph Co., Filed:Apr 27, 1877 Pub: May 3, 1892, 381/179 -

485311 Telephone, Anthony C White, American Bell Tel, 1892-11-01, - hermetically sealed carbon granul case.

1891 Dial System working

Second generation system using Common Battery signaling, and sometimes common battery power for the carbon mike.
447918 Automatic Telephone Exchange March 10, 1891 A. B. Strowger 379/302   this is the class for dial systems
449106 Telephone Circuit and Aparatus, J. J. Carty, Mar. 31, 1891  379/177

1892 Carbon Mike & Strowger

474230  Speaking-Telegraph, Thomas Edison, May 3, 1892 381/177
Web page devoted to this carbon type transmitter, a patent that took 15 years to grant.
485311 Telephone, A. C. White Nov. 1, 1892 381/180 - Granular Button Transmitter element assigned to American Bell Telephone
This is newer than the T.A. Edison carbon mikes and is the one used by the millions.
See Western Electric Candlestick Dial Telephone -
486909 Automatic Telephone or other Electrical Exchange, A.B. Strowger, 1892-11-29, 335/111 -

Better (Long Pole) Receivers

Magneto Era: @16:36 Long Pole Receivers, WE: Outside Terminal Receivers, @17:58 Phelps Crown Receivers (multi-pole) (not finding any US patents), @18:30 Pony Crown, @18:39 Gower Receiver ("D" magnet with gap in straight part), @23:15 Gower Bell telephone (2 listening tubes), 23:53 Hughes Telephone, 24:27 American Triple Box Design, @25:15 Twin Box, @28:34 WE Swing Arm Desk Phone, @29:23 Ericsson Skeletal, @29:52 UK WE Eiffel Tower, @30:20 B.P.O. Skeletal Design, @31:15 American Dest Stand aka: Candlestick,  

Wood Wall Phone Patent Dates (was American Bell Telephone, Triple Box )
Type 21 Patented: Oct 31, 1882; Dec 23, 1884; Nov 16, 1886, Apr 8, 1890; Mar 31, 1891; Jul 11, 1893
Type 44 Patented: Apr 8, 1890; Jul 11, 1893
Type 72 Patented: Nov 9, 1886; Mar 3, 1891; July 4 or 11, 1893; July 17, 1894; Mar 3, 1896
Type 72 Patented: Oct 31, 1882, Dec 23, 1884; Nov 16, 1886;, Apr 8, 1890; Jul 11, 1898
Type?? Patented: Apr 16, 1878; Dec 17, 1878; May 17, 1879; Nov 11, 1879; American Bell Tel
Type?? Patented: APRIL 16, 1878; DEC 17, 1878; JULY 30, 1879; PAT NOV 11, 1879
No. 4 top box Patented: APR 6 1878; JAN 8 1883
Type?? Patented: APRIL 16, 1878, DEC 17, 1878, MAY 27,1879, NOV 11, 1879, AUG 31, 1880, JULY 20, 1880, JAN 9 1883, DEC 28, 1884

507728 Telephone, S.D. Field, American Bell Tel,1893-10-31, - looks like the right angle drive used on Sound Powered Phones (much more efficient)
540969 Telephone, S.D. Field, American Bell Tel, 1895-06-11, -
575394 Magneto-telephone, S.D. Field, American Bell Tel, 1897-01-19, - external terminals and central screw that holds horseshoe magnet
833279 Telephone-receiver, Henry F Albright, Western Electric (AT&T), 1906-10-16, 381/417 -  tubular long pole magnet and metal case (rubber has different thermal expansion than magnet, so prior art rubber case units have problem.)

1893 Bell's first patent runs out

529421 Multiple Switchboard System Nov 20, 1894 C. E. Scribner  379/319; 379/313; 379/332
545416 Telephone Aug 27, 1895 G F Shaver 379/350 - new carbon mike and improved wiring
570840 Automatic Telephone System Morgan Brooks Nov 3, 1896 379/215.01; 340/298; 340/313; 379/258
597062 Calling Device for Telephone Exchanges, A. E. Keith & C. J. Erickson, Jan. 11, 1898  379/365; 340/294; 379/367
    assigned to the Strowger Automatic Telephone Exchange, replaced the origional buttons with a dial, this is the first patent in class 379/367
670564 Telephone Receiver, C. H. North, March 26, 1901  381/393 - has internal terminals
687499 Telephone Transmitter (Candlestick), Nov 26, 1901, WW Dean, Kellogg, 381/180 ; 381/186; 381/347  - preventing carbon granules from compacting.  (found this while looking for patent 112158 which is not a Kellogg phone patent)
815176 AutomaticTelephone Connector Switch March 13, 1906 A E Keith & C J Erickson (AE Co)  379/302; 379/303 - modern step & repeat    switch, 26 page patent, very complex switch with many parts
815321 AutomaticTelephone Connector Switch March 13, 1906 A E Keith & C J Erickson (AE Co) 335/109; 74/21; 74/156; 74/169; 74/575; 379/302 - more on the step & repeat switch

831875 Interrupter for Automatic Telephone or other switches Sep 25, 1906 A E Keith (AE Co) 379/302; 379/337

848398  Automatic Exchange Selector March 26, 1907 J G Roberts (WE Co) 379/302; 335/136; 340/825.4

1050304 Telephone-transmitter, Charles E Scribner, Western Electric,1913-01-14, - carbon mike with cone mouthpiece, like on wooden phone, or candlestick.
1508424 Telephone Desk Set Sep 16, 1924 G. K. Thompson (AT&T)  379/424; 379/436; 379/454 - dial phone with cradle for handset
1565581 Telephone Transmitter, C. H. Moore, Dec. 15, 1925 381/180 Not position sensitive
1602824 Telephone Receiver, L L Jones 381/419 ; 310/25; 367/182
1615311 Impulse Sending Device Jan 25, 1927 H. F. Obergfell   (Automatic Electric) 341/184; 379/366 - rotary dial

1642822 Calling Device Sep 20, 1927  H. F. Obergfell (Automatic Electric) 379/367; 379/369 - rotary dial

1719992 Calling Device July 9, 1929  H. F. Obergfell (Automatic Electric) 379/362; 379/367

1894 Transformer

519347  Transformer for Telegraphic, Telephonic or other Electrical Systems, M I Pupin, May 8, 1894, 379/398 ; 307/109; 333/177; 333/27; 336/182
This patent purchased by Bell Telephone in 1901.

Mounts

See: Western Electric Candlestick Dial Telephone
769702 1904-09-13 App 1903-06-06; Lattig & Goodrum (), Telephone Transmitter
1125965 Automatic switching system, Edgar H Clark, Western Electric Co Inc, 1915-01-26 App 1908-01-20;

1125997 Selective signaling system, Joseph C Field, Western Electric Co Inc, 1915-01-26 App 1912-08-23
1251995 Telephone desk-stand, Oscar F Forsberg, Western Electric Co Inc,  1918-01-01 - WE 50AL Telephone Desk Stand
1124021 Impulse-transmitter, William F Hoffmann, Western Electric Co Inc
1161854 Calling Device, O.F. Forsberg, Western Electric Co Inc, Nov 30, 1915, 379/366; 188/184; 379/367 - WE Type D-8083 Dial
1251995 Telephone desk-stand, Oscar F Forsberg , Western Electric Co Inc, 1918-01-01 - WE 50AL Telephone Desk Stand
D52010 Desk Telephone Stand, O.F. Forsberg, Western Electric Co Inc, May 7, 1918, - WE 50AL Telephone Desk Stand
1353612 Telephone Exchange System, F.N. Reeves, Sept 21, 1920 - 50AL dial wiring for candlestick phone

Bakelite (Wiki)

Started looking for a replacement for shellac (Wiki) and announced Bakelite in 1909.

Patents by Leo H. Baekeland.

Dials

1030412 Impulse-transmitter, Jacob W Lattig, American Automatic Telephone Co, 1912-06-25, 379/362 -

Design Patents

D14/149 & D14/153 & D14/248

D23825 Transmitter-post for telephones, William Gray, Nov 27, 1894 D14/149 - microphone only
D24175 Telephone-support, Apr 2, 1895 D14/149 -
D30794 Base and casing for portable telephones, Benjamin Le Vino, May 16,, 1899 D14/153 -
D32527 Telephone-standard, Apr 17, 1900 D14/149 -
D41616 Telephone desk-stand, William W. Bean, Jul 25, 1911 D14/149 - microphone only
D41794 Telephone desk-stand, John G. Blessing, Sep 19, 1911 D14/153  -
D43173 Bottle, George R. West, Oct 15, 1912 D9/600; 446/141; D14/149- microphone & long pole receiver whiskey bottle
D52010 Desk Telephone Stand, Oscar F. Forsberg, May 7, 1918, D14/153  -
D57700 Desk-stand for hand-telephones, Ernest S. Mclarn, Apr 26, 1921, D14/153 -
D57701 Desk-stand for hand-telephones, Ernest S. Mclarn, Apr 26, 1921, D14/153 -
D65204 Design for a desk stand for hand telephones, George K. Thompson, American Tele, Jul 15, 1924 D14/149 - A1 Mount design
D68929 Combined ringer box and telephone desk stand, Herbert F. Obergfell, Dec 1, 1925, D14/153 379/436 -
D74188 Telephone Desk Stand, H.F. Obergfell, Jan 3, 1928 - center plunger hook switch, fork type support D14/149 - Type A desk stand
D78605 Telephone desk stand, Henry Melvin Bascom, May 28, 1929, D14/153
D80670 Desk stand for a hand telephone, Nelson Blount, Mar 11, 1930 -
D80671 Desk stand for a hand telephone, Nelson Blount, Mar 11, 1930 -
D80672 Desk stand for a hand telephone, Nelson Blount, Mar 11, 1930 -
D81476 Desk stand for a hand telephone, Rene Clarke, Jul 1, 1930, D14/153 -
D81510 Desk stand for a hand telephone, John Vassos, Jul 1, 1930, D14/153 -
D81511 Hand telephone, John Vassos, Jul 1, 1930, D14/248 -
D81512 Desk stand for a hand telephone, John Vassos, D14/248 -
D81513 Hand telephone, John Vassos, Jul 1, 1930, D14/153 -
D81562 Desk stand for a hand telephone, John Vassos, Jul 8, 1930, D14/153 -
D81680 Desk stand for a hand telephone, Lttcian Bernhard, Jul 29, 1930, D14/153 -
D82414 Desk stand for a hand telephone, Lttcian Bernhard, Nov 4, 1930, D14/153 -
D83514 Telephone desk stand, George B. Eaton, KELLOGG SWITCHBOARD a SUPPLY CO, Mar 3, 1931 D14/149 - center plunger hook switch, depressions for transmitter & receiver
D83515 Telephone desk stand, George B. Eaton, KELLOGG SWITCHBOARD a SUPPLY CO, Mar 3, 1931 D14/153 - center plunger hook switch, depressions for transmitter & receiver
D86263 Telephone desk stand, H.F. Obergfell, Feb 16, 1932 D14/153 - AE 34 desk stand
D88804 Desk stand for a hand telephone, George R. Lum, Dec 27, 1932, D14/153 -
1971499 Telephone handset, Herbert F Obergfell, 1934-08-28, 381/344; 381/391 -
2008287 Telephone substation apparatus, George R Lum, Bell Labs, Jly 7, 1935, 379/424 D14/153 379/436 379/437 -
2019601 Telephone substation apparatus, William A Evans, Nov 11, 1935, 379/436 D14/153 -
D92442 Telephone instrument, Everett Worthington, Jun 5, 1934 - center plunger hook switch, fork type support, spit cup transmitter, place for dial
D94158 Wall telephone, Herbert F. Obergfell, Dec 25. 1934 - AE 35 wall telephone
D95765 Desk stand for a hand, George R. Lum, May 28, 1935 - Bell System 302
D104087 Telephone desk stand, Henry E. Billington, Kellogg Switchboard a Supply Company, Apr 13, 1937 - art deco
D106322 Telephone Handset Mounting, M. L. Nelson,, Oct 5, 1937, D14/153 -
D106457 Combined Telephone Desk Stand and Handset, R.F. Stehlik, Oct 12, 1937, D14/153 -
2127569 Desk telephone, Herbert F Obergfell, Associated Elec Labs, Aug 23, 1938, 379/352 379/427 D14/153 379/436 -
D108022 Design for a telephone hand-set, Hans Sengebuseh, Jan 18, 1938, D14/153 -
D109123 Combined Hand Telephone and Stand therefor, H. Bergman, Apr 5, 1938, D14/153 -
D109648 Telephone cabinet, Theodore N. Saaty, The Screw Machine Products Corporation, executive desk control with buttons on front panel and a couple of speakers
D117876 Telephone desk stand, H. F. Obergfell, Nov 28, 1939, D14/153 -
2296846 Telephone calling dial, Harold W Goff, Bell Labs, Sep 29, 1942, 362/23.06 362/23.01 D14/153 362/274 379/367 362/602 -
D132902 Stand for a hand telephone, Jack Barofsky, Jun 30, 1942 - art deco
D135389 Loud-speaking telephone, Gabriel M. Giannini, Mar 30, 1943 D14/153 379/432 - with dial but no handset
D135401 Loud-speaking telephone, Gabriel M. Giannini, Mar 30, 1943 D14/153 379/432 - with dial but no handset
D135495 Loud-speaking telephone, Gabriel M. Giannini, Apr 13, 1943 D14/153 379/432 - with dial but no handset
2338757 Telephone set, Stanley T Curran, Bell Labs, Jan 11, 1944, 379/423 D14/153 200/314 - 302 with 6 buttons?
2364771 Telephone signaling system, Henry M Bascom, Francis A Hubbard, Bell Labs, Dec 12, 1944,
379/171 340-12.12 379/364 341/20 D14/153 - 302 with 15 buttons
D140904 Combined telephone desk stand and hand set, Gerald Deakin, Apr 17, 1945, D14/153 379/436 379/368 - 0 to 9 push buttons facing up AND a dial
D141425 Combined telephone desk stand and handset, Edward F. Mckenna, May 29, 1945, D14/153 379/454 -
D141641 Convertible desk and wall telephone set, Max G. Kolmes, Internanational Standard Electric Corp., Jun 19, 1945 - with optional hand crank
D144130 substation telephone instrument, Herbert F. Obergfell, Mar 12, 1946, , D14/153 - dial & hand crank
D144674 Stand for a Hand Telephone, Jack Barofsky, May 14, 1946, D14/153 -
2428593 Telephone substation set, Walter D Teague, Jr Walter D Teague, Kellogg Switchboard and Supply, Oct 7, 1947, 379/424 D14/153 379/436 -
D151121 Erickson telephone desk unit, Clifford E. Erickson, Kellogg Switchboard & Supply CO., Sep 28, 1948 -
2479198 Telephone instrument, Baker George Thomas, Automatic Electric Lab, Aug 16, 1949, 379/433.01 D14/153 379/434 - sort of trim line with spit cup
2487013 Portable radio receiver, Frank A Zibelman, Nov 1, 1949,
455/149 D14/153 312/7.1 455/175.1 455/350 - AM radio built into 302 case
D153927 Desk Stand for a Hand Telephone, Henry Dreyfuss, Robert H. Hose, Bell Telephone Labs, May 31, 1949, D14/149 - Bell System 500 Calls D95765 & D151121
D153928 Desk Stand for a Hand Telephone, Henry Dreyfuss, Robert H. Hose, Bell Telephone Labs, May 31, 1949, D14/153 - Bell System 500
D159188 Telephone Set, Hiram D. CurrierLeich Electric Company, Jul 4, 1950 - a 302 telephone with the dial replaced by a hand crank?
D210776 , D210777 Telephone stand, Henry Dreyfuss, Bell Telephone Labs, Nov 19, 1957 - Princess

Newer Patents

2443329 Telephone handset bracket, Sterling G Sears, 1948-06-15, - on the "bracket": ROANWELL, U.S. Pat. No. 2443329 - on red crypto wall phone: TA-840A/U, Telephone Set, 24VDC 150 mA, PT 28687 - 74E10N100

2567812 Code transmitter, Clarence N Hickman, Bell Labs, 1951-09-11, - AC signaling has advantages over DC signaling.  Telephone set with 4x2 tone keyboard.

3627930 Dial-in-handset telephone assembly, Warren R Tolman, AT&T, 1971-12-14 - Trimline (Wiki)

4823379 Telephone ringer 379/373.01 ; 340/397.5 - This is an example of something that looks like a good idea.  BUT . . . the way it's been manufactured it's so fragile that age or dropping the phone breaks the plastic parts.  So professional phone installers avoid any phone that contains this ringer like the plague.

Cross Bar Switch replaces the Step and Repeat Switch

Third generation switching, didn't last that long

Electronic Switch replaces the Cross Bar switch

Forth generation, and now current, switching.

USPTO Classification Numbers Relating to "Telephone"
Telephone ..................................
  379
    Answering device   
        Answering-recording system .........  D14 / 141
        Calling number recorder ............  379 / 142.01+
        Remote inquiry .....................  379 / 76
        Sound recorder or reproducer .......  379 / 70+
    Attachment .............................  379 / 441+
        Base pad ...........................  248
        Index ..............................  40 / 336+
        Pad ................................  281 / 44
        Roll type pad ......................  281 / 11
    Automatic systems ......................  379 / 258+
        Call ...............................  379 / 350+
            With recorded message ..........  379 / 69
        Card ...............................  40 / 336+
        Common control .....................  379 / 268
        Party line .........................  379 / 182+
    Booths .................................  52 / 27+
        Design .............................  D25 / 16
        Movable wall .......................  52 / 71
    Calling ................................  379 / 352+
    Card attached to telephone .............  40 / 336+
    Cellular or zoned radiotelephone .......  455 / 422.1+
    Coin collectors for pay stations .......  194
    Coin operated ..........................  379 / 143+
    Computerized switching .................  379 / 284
    Cordless ...............................  455 / 462+
    Design .................................  D14 / 142+
    Dial  
        Dial structure .....................  379 / 362+
        Illuminated ........................  362 / 24
        Locking ............................  379 / 445
        Pulse transmitter ..................  379 / 362+
        Self luminous ......................  40 / 337
        Telephone system ...................  379 / 258
    Directory ..............................  40 / 371
    Earth transmission .....................  455 / 40
    Handset ................................  379 / 433.01+
    Headgear support .......................  379 / 430
    Key systems ............................  379 / 156+
    Light wave telephony ...................  398 / 132+
    Lights for telephones ..................  362 / 88
    Mechanical telephones ..................  181 / 138
    Message counter ........................  379 / 139
Muffler for mouthpiece .................  181 / 242
    Over composite line used for ...........  379 / 90.01+
    Other services .........................  379 / 90.01+
    Pad or book holder combined ............  248 / 441.1+
    Party line .............................  379 / 177+
    Plural phone systems ...................  D14 / 241
    Push button call transmitters ..........  379 / 368+
    Radio transmission .....................  455
    Receiver and transmitter combined ......  379 / 433.01+
    Repeaters ..............................  379 / 338+
        Dial pulse .........................  379 / 341+
            Conversion .....................  379 / 339
        Voice frequency ....................  379 / 338+
    Repertory dialers ......................  379 / 355.01+
    Sets ...................................  379 / 419+
    Sterilizer .............................  379 / 439
    Supports ...............................  379 / 454+
    Switchboard ............................  379 / 319+
    Switches ...............................  379 / 422+
    Telemetry ..............................  128 / 904*
    Toy telephones .........................  446 / 141
        Design .............................  D21 / 517
    Train telephony ........................  246 / 7+
    Transducers ............................  379
Class 381 Electrical Audio Signal Processing Systems and Devices
Telephone Microphone.................... 381/355
231226 Telephone Transmitter Aug 17, 1880 G. M Hopkins 381/166; 381/355
          202870 Speaking-Telephone Transmitter April, 23, 1878 G. B. Richmond 381/166

        652230 Art of Reducing Attenuation of Electrical Waves  and Apparatus therefor  June 19, 1900  M. I. Pupin - Loading Coil

Related

Phones
Sound Powered Phones, Speakers,  &Etc.

Links

Spark Museum: Early Telephone Apparatus -

The Telecom Archive; (Formerly The Bell System Practices (BSP) Archive) - patents -

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