Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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| Number | Title | Issue Date |
| 4430647 | Monitor for detecting malfunction of a rotation-angle transducer In order to monitor the correct mounting of a rotation transducer on a rotary part, the output signal of the rotation of the indicator is caused to produce a first pulse at a particular angular position. An additional reference mark transducer is coupled ... | 02/07/1984 |
| 4179938 | Dual indicating tachometer apparatus A dual indicating tachometer apparatus for utilization with ground vehicles such as automobiles and trucks for differentiating between the rotational speeds of the engine and clutch shaft of the vehicle. Two sensing devices are utilized with one monitorin... | 12/25/1979 |
| 4135082 | Electrical pulse train comparator A digital data acquisition system wherein a succession of electrical impulses whose frequency is characteristic of an operation to be measured is compared with a reference electrical pulse series.... | 01/16/1979 |
| 4040508 | Control circuit for controlling the shaft speed of a motor having clutch and brake devices A control circuit for controlling the shaft speed of a motor having clutch and brake devices comprises a speed detector for detecting the actual rotating speed of the motor and generating a first pulse signal having a period in inverse proportion to the a... | 08/09/1977 |
| 4039781 | Circuit arrangement for protective couplings A circuit arrangement for protecting an overload coupling includes respective pulse generating elements which produce respective pulse trains, the difference between individual repetition rates of which is a measure of slip. A pulse comparator, in the for... | 08/02/1977 |
| 3963902 | Method and apparatus for pre-registration of a multiple cylinder rotary printing press Each print cylinder in a multi-color printing press is provided a numerical address for each registration tolerance increment around the print cylinder circumference. An electrically determined reference point common to all print cylinders determines the ... | 06/15/1976 |
