Automatic release hospital thermometer
OwnerJon L. Krahmerinventor
Life of this patent
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Abstract
A new arrangement for facilitating the taking of temperatures both in hospitals and in the home by simplifying the resetting of a clinical thermometer to a lower, ambient temperature after use. A plunger in the reservoir of the thermometer is magnetically actuable into a position in which it disables a restriction at which the mercury column separates to retain a reading. Several forms of this plunger are shown, and also shown is a holder for use with the thermometer to actuate the plunger.
Claims10
In a clinical thermometer in which a thermometric liquid expands and contracts to give a meniscus which moves linearly in a stem with respect to fixed temperature graduations thereon:
- an elongated tube of transparent material characterized by a first temperature coefficient of expansion, and having a capillary bore connected at one end to a closed reservoir for liquid;
- temperature correlated graduations disposed in a scale along a first portion of said tube in contiguity to said bore;
- valve means including a member movable with respect to said tube between a normal position, in which limited passage is provided between said reservoir and said bore, and an actuated position in which substantially free passage is enabled between said reservoir and said bore;
- and a liquid in said reservoir having a greater coefficient of thermal expansion than said transparent material, the quantity of said liquid being such that as the ambient temperature rises within a predetermined range said liquid expands out of said reservoir into said bore in contiguity with said graduations, and said limited passage being so small as to prevent unaided movement of said liquid back into said reservoir, although permitting expansive movement of said liquid from said reservoir to said bore, so that as the ambient temperature falls, within said range, the body of liquid separates at the restricted passage said valve means being located in said reservoir and being magnetically actuable from without said reservoir.
In a clinical thermometer comprising a closed elongated tube of transparent material characterized by a first coefficient of thermal expansion and having temperature-correlated graduations disposed in a scale along a principal portion thereof, said tube having a capillary bore in contiguity with said graduations and communicating with a reservoir of liquid characterized by a greater coefficient of thermal expansion than said material, so that when said liquid is heated said liquid moves outward in said bore from said reservoir, said bore having a restriction near said reservoir, so that when said liquid is cooled the column of liquid in said bore separates at said restriction.
- the improvement wherein said restriction comprises valve means including a member movable in said tube between a normal position, in which it provides limited passage between said reservoir and said bore, and an actuated position in which it enables substantially full passage between said reservoir and said bore said valve means being located in said reservoir and being magnetically actuable.
In a thermometer:
- a reservoir for thermometric liquid;
- a graduated bore connected to said reservoir by a tapering transition;
- valve means in said reservoir including a plunger and means resiliently urging said plunger into internal engagement with said tapering transition,
- the configuration of said transition and said plunger being such that said engagement results in a restricted pathway between said reservoir and said bore of predetermined size large enough to permit flow of said liquid from said reservoir to said bore upon rise in ambient temperature, but small enough to prevent return flow of said liquid from said bore to said reservoir upon fall in ambient temperature,
- at least a portion of said plunger remote from said transition being of magnetic material so that said plunger may be magnetically actuated, from without said reservoir, out of said engagement with said transition to enable unrestricted passage between said bore and said reservoir.
In combination:
- a clinical thermometer magnetically resetable externally to the ambient temperature;
- and a holder for said thermometer including a magnetic member positioned to cause resetting of said thermometer when the latter is inserted vertically therein.
Dependencies are inferred from the claim text.