Film drive mechanism for panoramic dental X-ray machine
US4172977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1978 |
| Grant date | Oct 30, 1979 |
| Priority date | — |
| Expiry date | Mar 24, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B42/042
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Panoramic dental X-ray machine having an improved X-ray film drive mechanism for coordinating the speed of travel of the X-ray film with non-constant speeds of lateral chair shift to provide continuous radiographs of typical dental arch areas. The film drive mechanism employs a non-rotating cam slidably mounted about a motor shaft which rotates an assembly comprising a tubehead and a cassette holder assembly. The non-rotating cam is provided with adjacent opposing slope areas for programming decreased film travel speed when the incisors of the dental arch are being X-rayed. The film is traveling at its slowest rate of speed when the midline of the incisors is being X-rayed while the chair is traveling at its fastest rate of speed thereat. The chair shifts during the X-raying of the anterior region only. A cam follower is mounted to a plate which is pivotally mounted to the tubehead-cassette holder assembly for rotation with assembly. The plate also mounts cable and roller means which cooperate to urge the follower to constantly contact working surfaces and the adjacent opposing slope areas of the non-rotating cam. The chair shift speed is controlled by a rotating barrel cam having …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.