Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
  • G09B29/00—Maps; Plans; Charts; Diagrams, e.g. route diagram
  • G09B29/10—Map spot or coordinate position indicators; Map reading aids
• • 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)
• Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Mathematical Physics (AREA)
• Business, Economics & Management (AREA)
• Educational Administration (AREA)
• Educational Technology (AREA)
• General Physics & Mathematics (AREA)
• Signal Processing (AREA)
• Telephone Set Structure (AREA)
• Transmission Devices (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20304585

Family Applications (1)

Country Status (3)

• 0
  • NL NL23377D patent/NL23377C/xx active
  • FR FR559589D patent/FR559589A/fr not_active Expired
• 1922
  • 1922-12-07 GB GB33457/22A patent/GB190475A/en not_active Expired

Also Published As

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