Time-lapse indicator or the like
AssigneeMicro-Circuits Company
InventorRobert F. Bradley
Life of this patent
Estimating the term…
Abstract
A time-lapse indicator in which a receptacle contains a fluid material having numerous discrete particles dispersed in a liquid carrier, and a layer of absorbent material in close proximity to the receptacle, the receptacle and absorbent material being separated from one another by a wall which is broken when the time period is to be determined by the indicator. The indicator normally has a pair of electrodes for measuring the resistance of the fluid material after a portion of the liquid carrier has been absorbed therefrom in the absorbent material. Mechanisms for both activating and reading the indicator may be used.
Claims16
A mechanism for activating a time-lapse indicator utilizing electrical or magnetic characteristics and having a layer containing fluid material with numerous discrete particles and a layer of absorbent material in close proximity to said first layer, separated therefrom by a frangible layer:
- said activating mechanism including a means for flexing said frangible layer to cause said layer to break into numerous pieces, thereby releasing the liquid in said fluid material to be absorbed by said absorbent material and thereby changing said characteristics of one of said layers, and means for feeding the indicator to said flexing means when the operation of the indicator is to be initiated.
A mechanism for reading a time-lapse indicator utilizing electrical or magnetic characteristics and having a fluid material containing a solid component of discrete particles and a fluid component and an absorbent material for absorbing said fluid component:
- said mechanism comprising a sensing means for determining the resistance of said fluid material after a portion of said fluid component has been absorbed by said absorbent material, and means indicating the resistance of said fluid material and thereby the length of time said fluid component has been absorbed by said absorbent material.
A method of using a time-lapse indicator utilizing electrical or magnetic characteristics and having a layer of absorbent material and a layer of liquid, said layer of liquid having numerous discrete solid particles, a ruturable wall seperating seperating said layers, the steps comprising rupturing said wall to bring together said layer of absorbent material and said liquid to activate said liquid layer to progressively change the concentration of said particles therein and thereby to change said characteristics of the indicator as the duration of time increases, permitting a period of time to lapse after activation, and utilizing said change in said characteristics to determine the lapse of time after activation of said one layer.
In a method of using a time-lapse indicator having a layer of absorbent material, a layer of liquid material, a rupturable wall separating said layers, and numerous electrically conductive discrete solid particles in one of said layers:
- the steps comprising rupturing said wall to introduce said fluid into said absorbent layer for varying the concentration of said solid particles in said one layer, permitting a period of time to lapse after introducing said fluid into said absorbent layer, and sensing the lapse of time by determining the change in conductivity of said conductive particles produced by the flow of said liquid into said absorbent material after said fluid has been introduced into said absorbent layer.
Dependencies are inferred from the claim text.