Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Telephone intercommunication system providing common access to a communication line










Image Number 4 for United States Patent #3931479.

A private telephone intercommunication system including facilities for connecting the system to a telephone central office. Common supervisory means are provided to control access to a line from each station.








 
 
  Recently Added Patents
Moving picture decoding device and moving picture decoding method
Automated top-down multi-abstraction infrastructure performance analytics -network infrastructure-as-a-service perspective
Workflow optimization for high throughput imaging environments
Client network device and method for adjusting parameters of client traffic windows based on discovery of other network devices
Methods and systems for presenting an inhalation experience
Stack and folding-typed electrode assembly and method for preparation of the same
Display screen or portion thereof with icon
  Randomly Featured Patents
Push-button switch device
Powder and grain feeder
CD apparatus with dynamic function generation
Low EMI shutdown circuit for modem applications
Method of making multilayered titanium ceramic composites
Polyaromatic ether-keto-sulfones curable by Diels-Alder cycloaddition
Plasmon-based color tunable devices
Image scanning device having direction-responsive programmable delay mechanism
Communication apparatus, communication method and communication program
Pyrrole derivatives and pharmaceutical compositions which contain them as hypnotics and anticonvulsants