US1788104A

US1788104A - Sterilizing test device

Info

Publication number: US1788104A
Application number: US458495A
Authority: US
Inventors: Hargreaves Wilfrid
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-05-31
Filing date: 1930-05-31
Publication date: 1931-01-06
Anticipated expiration: 1948-01-06

Description

Jan. 6, 1931. w, Ay s 1,788,104

STERILIZING TEST DEVICE Filed May 51 1930 INVENTOR W/LFRID HARGREA VES Patented Jan. 6, '1931 UNITED STATES "PATENT OFFICE STERILIZING TEST DEVICE Application filed May 81,

My invention relates to improvements in sterilizing test devices which are particularly adapted for insert-ion in garments and dressings which are to be treated in pressure sterilizers. The object of the invention is to provide a sterilizing test device which will react to a desired temperature in such a manner that no doubt can exist in the mind of the sterilizer operative as to the condition of the 1 articles treated, and to provide a test device which when once used is so changed that it cannot be used again, as experience has definitely shown that devices of this nature when reused are misleading and dangerous. A further object is to provide in such a device a written or printed word indicative of the condition of the articles in which it is placed, such indication showing the articles to be septic prior to sterilizing treatment and to be sterile after.

The invention consists essentially of a sealed tube in which is enclosed a label bearing such words as septic and sterile, the latter being excluded from view until the tube has been subject to a suitable sterilizing temperature and period, when the former. word becomes illegible and the latter exposed to view, as will be more fully described in the following specification and shown in the accompanying drawings, in which s Fig. 1 is a general view showing the obverse side of the-enclosed label.

Fig. '2 is-a view showing the reverse side of the label covered.

Fig. 3 is a view showing the reverse side oi the enclosed label after subjection to sterilizing heat.

In the drawings like characters of reference indicate corresponding parts in each figure. l I

The numeral 1 indicates generally a transparent glass tube sealed at its ends as at 2 and having attached thereto a thread 3 by which the tube can be readily located in the '45 articles treated in the sterilizer. Inserted in the tube 1 is a label 4 preferably made of absorbent paper, upon the observe side of which is a word 5 such as septic. The ink used in printing the obverse side is of a readily soluble nature or capable of being blurred when 1930. Serial No. 458,495.

subjected to a suitably high temperature. On the reverse side of the label a word 6 such as sterileis printed in an ink which is not soluble or subject to becoming illegible through being subjected to a sterilizing heat. 'Aflixed to the reverse side of the label to exclude the word sterile from view is any suitable covering material 7 which is capable of being rendered substantially transparent by subjecting it to suitable heat, and I have found that acid benzoic is eminently suited to this purpose since it is insoluble at a temperature of less than 240 degrees Fahrenheit, but readily melts at this or higher temperatures and is so absorbed by the label that the word originally covered thereby is rendered quite clear and legible. V

The device is inserted between'the articles placed in the sterilizer. When sterilization is thought to be completed the device is withdrawn and if proper sterilization has been attained throughout the articles the device will have been subjected to the proper temperature also, the result of such temperature being that the acid benzoic is changed from an opaque powder to a colorless solution which, when absorbent paper is used for the label, is absorbed by the label and serves to increase the illegibility of the word septic by dissolving the ink used in printing it, and causing said ink to spread.

If a non-absorbent'paper is used the acid benzoic on setting subsequent to cooling crys-- tallizes on the paper and over the word sterile, but does not revent the word from being clearly reada le and'proper indication of the condition of the articles sterilized being displayed.

It will be obvious that while an indica- I that the device is new and has not been subjected to sterilizing temperatures. It also follows that any material which is opaque and is capable of undergoing such change as to disclose the printing on the obverse side a of the-label when subjected to sterilizing heat will form a suitable substitute ,for the acid I benzoic herein mentioned.

What-I claim as my invention is: 1. A sterilizing control device comprisin a transparent body, an. absorbent printe label within the body, an opaque covering for the rinted matter on the label, said covering being capable of being absorbed by the I label at sterilizing temperatures. I 1 2. A sterilizin control device comprising a transparent body enclosing a label bearing a printed word indicative of a septic condition and of ,a sterile condition, means normally excludin the indication of sterili. 1 from view capable of change to expose suc c indication when the tube is subjected to sterilizing temperature and to render the word indicative of a septic condition permanently illegible. so 3. A sterilizin control device comprising a transparent body enclosing a label bearing a printed word indicatlvejof a septic condition and of a sterile condition, lfieans' nor mally excludin the indication of sterilitz 25 vfrom view capa le of change to expose sue Indication when the tube is subjected'to sterilizing temperature and to render the word indicative of a septic condition permanently illegible, said word indicative of a. septic conao dition bein printed with a medium capable of being dissolved at a sterilizing temperature.

4. A sterilizing control device comprising a sealed transparent body enclosin an absorbent label printed on one side wit a word indicative of sterility and on the other side with a word indicative of a. septic condition, said label ha aflix'ed to the side bearing the indication o sterility amaterial soluble 0 at about 250 degrees Fahrenheit and capable of being' absorbed b the label whereby the pr nted matter on t at side of the label is permanently expo'm to view. 5. A sterilizing control device comprising a sealed transparent body enclosing an .absorbent label printed on one side with water insoluble ink and on the other side with soluble ink, said label being covered on the insoluble ink side with an opaque substance to obscure said printed matter and capable of being dissolved at a temperature of about 250 de Fahrenheit and of being absorbed y the label, said substance when .dis- I solved serving to d ssolve the soluble ink and ra der the matter printed therewith illeg- 1 e. Dated at Vancouver, B. 0., this 14th day of May, 1980.

- WILFRID HARGREAVES.