Alexander Graham Bell's Patent for the Telephone
Alexander Graham Bell's 1876 patent describing the method and apparatus for transmitting vocal sounds telegraphically, effectively inventing the telephone.
Original patent title: “Improvement in telegraphy”
Alexander Graham Bell's 1876 patent describing the method and apparatus for transmitting vocal sounds telegraphically, effectively inventing the telephone. Granted to Individual in 1876 with 9 forward citations, and it is now in the public domain.
Key facts
Coverage
What does this patent actually cover?
The patent describes a method of transmitting vocal or other sounds telegraphically by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sounds. It utilizes a transmitter that converts sound waves into electrical currents through the movement of an armature in a magnetic field. These currents are then sent over a wire to a receiver, which converts the electrical energy back into sound waves. This process allowed for the first successful transmission of intelligible human speech over a distance.
The gap
What does this patent NOT cover?
- Does not cover digital signal processing or packet-switched voice transmission
- Does not cover wireless or cellular radio frequency transmission
- Does not cover modern fiber-optic voice communication systems
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
Bell realized that instead of using intermittent electrical pulses like a telegraph, he needed to create a continuous, undulating current that mimicked the actual waveform of the human voice.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Early liquid transmitters
Magnetic telephone receivers
The first experimental telephones
Why it matters
The bigger picture
This is widely considered one of the most valuable patents in history, as it provided the legal foundation for the birth of the telecommunications industry. It sparked intense legal battles over priority of invention, most notably against Elisha Gray, and established the framework for the Bell Telephone Company.
Filed
February 14, 1876
Granted
March 7, 1876
Market context
Who's building on this
Companies in this space
Modern telecommunications giants like AT&T, which traces its lineage directly back to the Bell Telephone Company, built the global infrastructure on the principles established here. Today, every voice-over-IP and cellular network still relies on the fundamental concept of converting sound to electrical waveforms.
Market impact
This patent triggered the creation of the global telephone network, fundamentally changing how humanity communicates. It led to the formation of massive corporate entities and established the precedent for how intellectual property would shape the development of national utility infrastructures.
Claim 1 — Plain English
What this patent covers
The patent describes a method of transmitting vocal or other sounds telegraphically by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sounds. It utilizes a transmitter that converts sound waves into electrical currents through the movement of an armature in a magnetic field. These currents are then sent over a wire to a receiver, which converts the electrical energy back into sound waves. This process allowed for the first successful transmission of intelligible human speech over a distance.
The clever bit
Bell realized that instead of using intermittent electrical pulses like a telegraph, he needed to create a continuous, undulating current that mimicked the actual waveform of the human voice.
What it does not cover
- Does not cover digital signal processing or packet-switched voice transmission
- Does not cover wireless or cellular radio frequency transmission
- Does not cover modern fiber-optic voice communication systems
Patent Journey
From filing to expiry
PatentBrief Score
Impact Score
Early stage
Citation count
20/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$5K – $15K
Midpoint $10K · expired or expiring · industry baseline
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Concepts involved
Citations
Patent lineage
Cite this patent
Bell, A. G. (1876). Alexander Graham Bell's Patent for the Telephone (U.S. Patent No. 174,465). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/174465/bell-telephone
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Alexander Graham Bell's Patent for the Telephone cover?
Alexander Graham Bell's 1876 patent describing the method and apparatus for transmitting vocal sounds telegraphically, effectively inventing the telephone.
Who owns patent US 174465?
Individual owns this patent, granted in 1876.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 174465 cited by?
This patent has been cited by 9 later patents that build on its ideas.
What problem does this patent solve?
This is widely considered one of the most valuable patents in history, as it provided the legal foundation for the birth of the telecommunications industry. It sparked intense legal battles over priority of invention, most notably against Elisha Gray, and established the framework for the Bell Telephone Company.
What does this patent NOT cover?
Does not cover digital signal processing or packet-switched voice transmission
Same assignee
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