초록 ▼

A defrost indicator is configured such that the process of freezing and defrosting the defrost indicator places the defrost indicator into a state that is not completely reversed by refreezing, so that one can detect whether the defrost indicator defrosted and refroze or never defrosted by observing

A defrost indicator is configured such that the process of freezing and defrosting the defrost indicator places the defrost indicator into a state that is not completely reversed by refreezing, so that one can detect whether the defrost indicator defrosted and refroze or never defrosted by observing its current state. In an embodiment, the defrost indicator is initially placed in a first state before being frozen (e.g., upside down with fluid in an upper chamber). Freezing the defrost indicator places it in a second state (e.g., with the fluid frozen in the upper chamber). Then when the defrost indicator is defrosted, the defrost indicator is placed into a third state that is different than the first state (e.g., right-side-up with liquid fluid in the lower chamber). If the defrost indicator is again frozen, the defrost indicator is placed into a fourth state (e.g., the fluid frozen in the lower chamber).

대표청구항 ▼

The invention claimed is: 1. A device comprising:walls enclosing an indicator including at least a material that has at least two reversible states that are visibly distinct from one another, a first of the two reversible states occurs when the indicator is initially frozen while the indicator is in

The invention claimed is: 1. A device comprising:walls enclosing an indicator including at least a material that has at least two reversible states that are visibly distinct from one another, a first of the two reversible states occurs when the indicator is initially frozen while the indicator is in a first orientation, and a second of the two reversible states occurs as a result of the indicator defrosting and refreezing while the indicator is in a second orientation, the two reversible states are reversible in that once in the second state, by defrosting the indicator, reorienting the indicator to the first orientation, and refreezing the indicator, the state of the indicator is changed from the second state back to the first state, so that the indicator is ready for reuse, without opening the indicator;the walls including at least one wall having at least a portion through which the material is visible while the material is in at least one of the at least two reversible states, the state of the indicator being determinable by looking into the window,the material being a fluid, the indicator including a container having two chambers between which fluid that is not frozen is not inhibited from flowing by structural features into either container, the fluid that is not frozen is not inhibited from flowing at all times including prior to use,in the first of the two reversible states, the fluid is frozen and located within a first of the two portions of the container, andin the second of the two reversible states at least some of the fluid that was in the first of the two portions of the container is now in a second of the two portions of the container, the fluid being visible via the window when the fluid is in at least one of the two reversible states.