Open end thermometer

Claim 2

A low cost disposable clinical thermometer structure comprising: a molded plastic capillary element having a through capillary bore defining an open outer end defining a capillary opening and an open inner end; bulb means extending from the capillary element defining a reservoir chamber communicating with said capillary bore inner end; scale means on said capillary element; an expandable liquid indicator in said reservoir chamber and extending upwardly therefrom into said capillary bore, said capillary opening effectively precluding passage of indicator liquid outwardly therethrough other than as a result of expansion of the liquid; and means for indicating a defective condition of the thermometer resulting from a loss of a portion of the liquid indicator by a passing thereof out through said capillary opening notwithstanding evaporation of the passed liquid.

Claim 3

The thermometer structure of claim 1 wherein said means for indicating said defective condition comprises means at said capillary opening for retaining at least a portion of the liquid indicator passed outwardly through said capillary opening.

Claim 4

The thermometer structure of claim 1 wherein said means for indicating said defective condition comprises means packaging at least the outer end of the capillary element responsive to passage of said liquid indicator portion outwardly from said capillary opening to retain said liquid portion for subsequent observation by a user.

Claim 5

The thermometer structure of claim 1 wherein said means for indicating said defective condition comprises means packaging the entire thermometer.

Claim 6

A low cost disposable clinical thermometer structure comprising: a molded plastic capillary element having a through bore defining an open outer end and an open inner end; bulb means joined to the capillary element defining a reservoir chamber communicating with said capillary bore inner end; an expandable liquid indicator in said reservoir chamber and extending upwardly therefrom into said capillary bore; and means for indicating an abnormal condition wherein the liquid indicator has expanded to have a portion thereof pass out through said capillary bore open outer end defined by means secured to the capillary element and having a portion extending about the distal end of the capillary element across said bore outer end.

Claim 7

A low cost disposable clinical thermometer structure comprising: a molded plastic capillary element having a through bore defining an open outer end and an open inner end; bulb means joined to the capillary element defining a reservoir chamber communicating with said capillary bore inner end; an expandable liquid indicator in said reservoir chamber and extending upwardly therefrom into said capillary bore; and means for indicating an abnormal condition wherein the liquid indicator has expanded to have a portion thereof pass out through said capillary bore open outer end defined by means secured to the capillary element and having a portion extending about the distal end of the capillary element across said bore outer end.

Claim 8

A thermometer structure comprising: a capillary element having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expandable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capilLary element as long as the thermally expanded volume of the liquid indicator incompletely fills and reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore, said indicator liquid comprising a liquid having a low hygroscopicity of no more than approximately that of ethylene glycol phenyl ether.

Claim 9

A thermometer structure comprising: a capillary element having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expandable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capilLary element as long as the thermally expanded volume of the liquid indicator incompletely fills and reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore, said indicator liquid comprising a liquid having a low hygroscopicity of no more than approximately that of ethylene glycol phenyl ether.

Claim 10

The thermometer structure of claim 6 wherein said liquid indicator comprises a liquid which does not wet the capillary element.

Claim 11

The thermometer structure of claim 6 wherein said liquid indicator has a volatility of no more than approximately that of ethylene glycol phenyl ether.

Claim 12

A thermometer structure comprising: a capillary element having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expendable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capillary element as long as the thermally expanded volume of the liquid indicator incompletely fills said reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore, said outer end of the capillary bore having a cross-section smaller than that of the capillary bore inwardly of said outer end.

Claim 13

A thermometer structure comprising: a capillary element having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expendable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capillary element as long as the thermally expanded volume of the liquid indicator incompletely fills said reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore, said outer end of the capillary bore having a cross-section smaller than that of the capillary bore inwardly of said outer end.

Claim 14

The thermometer structure of claim 9 wherein said outer open end of the capillary bore has a diameter of less than approximately one-tenth that of the capillary bore inwardly thereof.

Claim 15

The thermometer structure of claim 9 wherein the diameter of said outer open end of the capillary bore is approximately 0.0010 inch.

Claim 16

The thermometer structure of claim 9 wherein said liquid indicator has a surface tension of at least approximately 40 dynes/centimeter.

Claim 17

The thermometer structure of claim 9 wherein said bore outer end has a cross-section smaller than that of the bore at said scale means.

Claim 18

A thermometer structure comprising: a capillary element formed of molded plastic having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expandable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capillary element as long as the thermally expanded volume of the liquid indicator incompletely fills said reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore.

Claim 19

A thermometer structure comprising: a capillary element formed of molded plastic having a through bore defining an open outer end and an open inner end; a bulb element extending from said capillary element and defining a reservoir chamber in communication with said capillary bore inner end; thermally expandable liquid indicator filling said reservoir chamber and defining a column extending into said capillary bore through said inner end, said outer open end of the capillary bore having a small capillary cross-section preselected to preclude flow of said liquid indicator outwardly therethrough irrespective of the position of said capillary element as long as the thermally expanded volume of the liquid indicator incompletely fills said reservoir chamber and capillary bore for providing a variable disposition of the end of the column of the liquid indicator in said capillary element bore as a function of the temperature thereof, whereby the end of the column of the liquid indicator in said bore is effectively maintained at atmospheric pressure through said capillary cross-section outer end of the bore; and scale means on the capillary element for providing a temperature reading as a function of the position of said end of the liquid indicator column in said bore.

Claim 20

The thermometer structure of claim 14 wherein said bulb is formed of metal.

Claim 21

The thermometer structure of claim 14 wherein said liquid indicator comprises a substantially nonwetting liquid.

Claim 22

The thermometer structure of claim 14 wherein said liquid indicator comprises a liquid which is not oxidized by being subjected to normal ambient atmosphere.

Claim 23

The thermometer structure of claim 14 wherein said liquid indicator comprises a phenyl ether compound.

Claim 24

The thermometer structure of claim 14 wherein said liquid indicator comprises a glycol phenyl ether.

Claim 25

The thermometer structure of claim 14 wherein said liquid indicator comprises an ethylene glycol phenyl ether.

Claim 26

The thermometer structure of claim 14 wherein said liquid indicator comprises a propylene glycol phenyl ether.

Claim 27

The thermometer structure of claim 14 wherein said liquid indicator has a boiling point of approximately 245* C.

Claim 28

The thermometer structure of claim 14 wherein said liquid indicator has a surface tension of approximately 40 dynes/cm.

Claim 29

The thermometer structure of claim 14 wherein said liquid indicator has a viscosity of at least approximately 20 centistokes at 25* C.

Claim 30

The thermometer structure of claim 14 wherein said liquid indicator has a stable air absorption characteristic.

Claim 31

The thermometer structure of claim 14 wherein said liquid indicator has low volatility at normal ambient temperatures.