FR514765A - Improvements to calling devices - Google Patents
Improvements to calling devicesInfo
- Publication number
- FR514765A FR514765A FR514765A FR514765DA FR514765A FR 514765 A FR514765 A FR 514765A FR 514765 A FR514765 A FR 514765A FR 514765D A FR514765D A FR 514765DA FR 514765 A FR514765 A FR 514765A
- Authority
- FR
- France
- Prior art keywords
- calling devices
- calling
- devices
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/26—Devices for calling a subscriber
- H04M1/30—Devices which can set up and transmit only one digit at a time
- H04M1/31—Devices which can set up and transmit only one digit at a time by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Meter Arrangements (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US299960A US1435253A (en) | 1919-05-26 | 1919-05-26 | Calling device for an automatic telephone system |
Publications (1)
Publication Number | Publication Date |
---|---|
FR514765A true FR514765A (en) | 1921-03-18 |
Family
ID=23157063
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR514765A Expired FR514765A (en) | 1919-05-26 | 1920-04-30 | Improvements to calling devices |
Country Status (2)
Country | Link |
---|---|
US (1) | US1435253A (en) |
FR (1) | FR514765A (en) |
-
1919
- 1919-05-26 US US299960A patent/US1435253A/en not_active Expired - Lifetime
-
1920
- 1920-04-30 FR FR514765A patent/FR514765A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US1435253A (en) | 1922-11-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
FR26710E (en) | Improvements to dial call devices | |
FR514765A (en) | Improvements to calling devices | |
FR506527A (en) | Improvements to cranes | |
FR506366A (en) | Improvements to snap-fit devices | |
FR502988A (en) | Improvements to ignition devices | |
FR520890A (en) | Improvements to carburettor devices | |
FR507597A (en) | Improvements to belt attachment devices | |
FR519084A (en) | Improvements to devices for calling circuits | |
FR529722A (en) | Improvements to vibrator devices | |
FR518905A (en) | Improvements to traction devices | |
FR552084A (en) | Improvements to anchoring devices | |
FR523126A (en) | Improvements to protective devices | |
FR523151A (en) | Improvements to thermionic devices | |
FR535326A (en) | Enhancements to magneto-operated telephone ringtones | |
FR520894A (en) | Improvements to thermostatic devices | |
FR516171A (en) | Improvements relating to anchoring devices | |
FR512434A (en) | Improvements to telephone cables | |
FR575139A (en) | Improvements to electric ignition devices | |
FR545314A (en) | Improvements to vibrating call devices in telephony | |
FR518075A (en) | Improvements to amplifying devices | |
FR512732A (en) | Improvements to clutch mechanisms | |
FR526728A (en) | Improvements to cranes | |
FR501755A (en) | Improvements to cranes | |
FR496103A (en) | Improvements to exhaust pumps | |
FR499331A (en) | Improvements to exhaust pumps |