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US 6,629,499 B1Granted
Temperature activated mechanical timer
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsMichael L. Greene, David R Keene
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Abstract
The present invention comprises a mechanical timer that operates by using the ambient temperature differences during daytime and nighttime periods in order to count desired intervals of days, months, etc. Embodiments of the invention employ the timer to render safe land mines or other ordnance devices after a specified period of time. Because the present invention uses ambient temperature differences in order to operate, no outside power source is required.
Claims10
A mechanical, temperature activated timer, comprising:
- a housing;
- at least one member, moveably attached to the housing, having a plurality of serrations arranged unidirectionally along an outside of the member;
- at least two pawls that cooperate with the serrations to allow movement of the member in one direction;
- and,
- at least one bimetallic, snap-action disc within the housing, having a first shape below a transition temperature and a second shape above the transition temperature, wherein transition from the first shape to the second shape causes a snap-action of the disc, moving the member a distance of one serration.
2 more elements
Dependencies are inferred from the claim text.