Patent ID: 8138454

Claim:
A liquid warming device comprising: a cavity adapted to receive a portion of a removable basin, the removable basin having a bottom, a set of at least one side wall connected to the bottom of the removable basin so that the set of at least one side wall forms a walled perimeter around the bottom of the removable basin to form a container suitable for holding a fluid, and a thermocouple well placed in the bottom of the removable basin and positioned in the cavity; a heater adapted to provide heat through a thermally conductive path to the fluid placed in the removable basin; a fluid temperature controller controlling a flow of energy provided to the heater so as to prevent the heater from operating without a positive indication of a presence of an appropriate removable basin; a fluid temperature sensor used to obtain a temperature from a surface of the removable basin; wherein the positive indication is received from a limit switch which is implemented with an actuator; wherein the limit switch is actuated by an insertion of an appropriate removable basin into the cavity; wherein the removable basin is placed to align the thermocouple well above the fluid temperature sensor and wherein the removable basin pushes down on the actuator which moves downward relative to the fluid temperature sensor and activates the limit switch to a closed position which indicates that an appropriate removable basin is in place in the cavity; wherein when the thermocouple well is not in its intended position above the fluid temperature sensor, the removable basin does not push down on the actuator and the limit switch remains in an open state; wherein the limit switch is open: (a) if there is not an appropriate removable basin in the cavity; or (b) if an appropriate removable basin is placed in the cavity but the thermocouple well is not aligned above the fluid temperature sensor; and wherein the liquid warming device provides an indication to users when the limit switch detects an appropriate removable basin but the limit switch is not activated by the actuator and remains in the open state.