Temperature sensitive reclosure indicator

• US 4,539,929 A
• Filed: 10/28/1983
• Issued: 09/10/1985
• Est. Priority Date: 10/28/1983
• Status: Expired due to Fees

• Current Assignee: American Sterilizer Company (Steris Corporation)
• Original Assignee: American Sterilizer Company (Steris Corporation)
• Inventors: Sestak, Joseph T., Coon, Dennis C.
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Worth, W. Morris
• Application Number:
  US06/546,313
• Time in Patent Office: 683 Days
• Field of Search: 116/2, 116/85, 116/101, 116/216, 116/221, 374/205, 337/343, 337/348, 337/376, 340/594, 126/388, 422/58, 422/118, 422/119, 436/1, 292/92, 292/DIG. 66, 49/2
• US Class Current: 116/221
• CPC Class Codes: A61L 2/26 Accessories or devices or components used for biocidal treatment
• CPC Class Codes: A61L 2/28 Devices for testing the effectiveness or completeness of sterilisation, e.g. indicators which change colour apparatus involving enzymes or microorganisms C12M1/34; methods involving enzymes or microorganisms C12Q1/00
• CPC Class Codes: G01K 3/00 Thermometers giving results other than momentary value of temperature G01K7/42 takes precedence
• CPC Class Codes: Y10S 292/66 Thermally controlled mechanism

Abstract

A device for indicating whether a container has been both exposed to a critical temperature and not subsequently opened which includes a housing, a temperature-sensitive member which assumes a first position and a second position within the housing, and a rigid member connected to the temperature sensitive member which moves into view when the temperature sensitive member assumes its second position upon exposure to a critical temperature, and moves out of view when the container is opened.

Claims

1. Apparatus in which articles can be sterilized and stored in a sterile condition comprising:

a container including a receptacle for holding the articles and a closure for said receptacle, said closure and said receptacle being movable, relative to each other, between an opened position, in which microbial life can enter said container and contact the articles, and a closed position, in which said closure and said receptacle prevent entry of microbial life into said container; and

an indicator assembly secured to said container, said indicator assembly including an indicator movable between two positions that are visually distinguishable from each other at least when the receptacle and closure assume their closed position, said indicator assembly including a temperature sensitive element, said element being so mounted to said indicator assembly that exposure of said element to an environment at a temperature falling within a predetermined range of temperatures for at least a predetermined length of time, when said indicator is in a first of its said positions, causes said element to move said indicator to a second of its said positions, subsequent exposure of said element to an environment at a temperature falling ouside said predetemined temperature range being insufficient to cause said element to return said indicator to its said first position, subseqent exposure of said element to an environment as a temperature not falling within said predetermined temperature range for at least a predetermined period of time coupled with the exertion of a force against said indicator sufficient to cause said indicator to travel through at least a predetermined distance toward its said first position causing said indicator to assume its said first position and to remain in said first position after said force is removed from said indicator;

said container including means for exerting said force against said indicator to move said indicator through said predetermined distance each time said indicator is in its said second position and said closure and container are moved, relative to each other, from a said closed position to a said opened position.

2. The apparatus recited by claim 1 wherein said indicator assembly permits relative movement of said receptacle and said closure from their said closed position to their said opened position regardless of the said position assumed by said indicator and the positioning of said element during use of said container.

3. Apparatus in which articles can be sterilized and stored in a sterile condition comprising:

a container including a receptacle for holding the articles and a closure for said receptacle, said closure and said receptacle being movable, relative to each other, between an opened position, in which microbial life can enter said container and contact the articles, and a closed position, in which said closure and said receptacle prevent entry of microbial life into said container;

a latch mounted to said container for securing said receptacle and said closure in a said closed position; and

an indicator assembly secured to said container including a housing, said indicator assembly further including an indicator movable between two positions that are visually distinguishable from each other at least when said receptacle and said closure assume their closed position, said indicator assembly including a temperature sensitive bimetallic strip secured at its ends to said housing, the distance between the points at which said ends of said strip are mounted being less than the length of said strip to cause said strip to be bowed, said indicator being secured to said strip and moving with the bowed section of said strip, said strip bowing in a first direction to move said indicator from a first to a second of its said positions when said strip is exposed to an environment at a temperature falling within a predetermined range for at least a predetermined period of time, subsequent exposure of said strip to an environment at a temperature outside said range being insufficient to cause said strip to bow in a second direction to return said indicator to its said first position, subsequent movement of said indicator to its said first position being effected by exposing said indicator to an environment at a temperature outside said range for at least a predetermined period of time and exerting a force against said indicator that causes said strip to bow in said second direction and move said indicator to its said first position;

said indicator assembly being so mounted to said container that movement of said latch, when said indicator is in its said second position and said strip has been exposed to an environment at a temperature falling outside said range for at least a predetermined period of time, to a position that permits movement of said closure and said container to a said opened position exerts said force on said indicator to return said indicator to its said first position;

said indicator assembly permitting relative movement of said receptacle and said closure from their said closed position to their said opened position regardless of the said position assumed by said indicator and the positioning of said strip during use of said container.