Vacuum cleaner clogged condition indicator
AssigneeWhirlpool Corporation
InventorLarry Thomas Bashark
Life of this patent
Estimating the term…
Abstract
A vacuum cleaner having an indicator for indicating an undesirable clogged condition of a dirt-collecting structure thereof. The indicator includes a control having a heater and a thermally responsive device responding to heat transferred from the heater to operate an observable indicator carried by the vacuum cleaner when a substantially clogged condition of the dirt-collecting means occurs. Operation of the indicator by the thermally responsive device is prevented as long as the dirt-collecting structure remains substantially unclogged as a result of the cooling action of air being flowed through the vacuum cleaner.
Claims11
In a vacuum cleaner having an air suction means including drive means, collecting means for removing entrained material from air flowed therethrough by said suction means, and means for conducting said air in heat transfer association with the drive means for cooling the drive means, means for indicating an undesirable clogging of the collecting means comprising:
- electrically operable indicator means carried by said vacuum cleaner;
- thermally responsive means for operating said indicating means when the thermally responsive means is heated to above a preselected temperature including a positive temperature coefficient resistor electrically connected to said indicator means for varying the effective voltage applied thereto;
- heater means having a preselected heating capacity for heating said thermally responsive means to above said preselected temperature;
- and thermally conductive means mounting said heater means and thermally responsive means in heat transfer association, at least one of said heater means and said thermally responsive means being in heat transfer association with the sucked air subsequent to its conduction in heat transfer association with said drive means for maintaining the thermally responsive means at a temperature below said preselected temperature when the collecting means is substantially unclogged whereby said indicating means is precluded from operating and thereby indicate the substantially unclogged condition of said collecting means, and permitting the heater means to heat said thermally responsive means to above said preselected temperature when the collecting means is substantially clogged whereby said indicating means is caused to operate and thereby indicate the substantially clogged condition of said collecting means.
In a vacuum cleaner having an air suction means including drive means, collecting means for removing entrained material from air flowed therethrough by said suction means, and means for conducting said air in heat transfer association with the drive means for cooling the drive means, means for indicating an undesirable clogging of the collecting means comprising:
- indicator means carried by said vacuum cleaner;
- thermally responsive means for operating said indicating means when the thermally responsive means is heated to above a preselected temperature;
- heater means having a preselected heating capacity for heating said thermally responsive means to above said preselected temperature;
- and thermally conductive means mounting said heater means and thermally responsive means in heat transfer association with at least one of said heater means and said thermally responsive means being in heat transfer association with the sucked air subsequent to its conduction in heat transfer association with said drive means for maintaining the thermally responsive means at a temperature below said preselected temperature when the collecting means is substantially unclogged whereby said indicating means is precluded from operating and thereby indicate the substantially unclogged condition of said collecting means, and permitting the heater means to heat said thermally responsive means to above said preselected temperature when the collecting means is substantially clogged whereby said indicating means is caused to operate and thereby indicate the substantially clogged condition of said collecting means, said thermally conductive means comprises a substrate element and said thermally responsive means includes a plurality of resistors comprising thick film resistors on said substrate.
Dependencies are inferred from the claim text.