Means for indicating dishwasher additive absence
First Claim
1. In a dishwashing machine comprising a reservoir for containing an additive, a supply line connecting the reservoir to a point within the dishwashing machine where the additive is normally added, a pumping means in the supply line for pumping the additive from the reservoir to said point, the pumping means including a check-valve means for retaining the additive in the supply line when the pumping means is not pumping, and control means for controlling the pumping means, the improvement which comprises:
- a vacuum operated switch and a connecting line connecting the vacuum operated switch to the supply line between the reservoir and the pumping means, the pumping means, switch and connecting line being physically located above the maximum possible level of additive in the reservoir, the vacuum operated switch comprising at least one pair of electrical contacts, a chamber opening only to the connecting line, one wall of the chamber defining a diaphragm moveable with respect to the remaining portion of the chamber, biasing means for biasing the position of the diaphragm to a preselected position, adjusting means for adjusting the biasing means and connector means for connecting the diaphragm to a moveable portion of the at least one pair of electrical contacts, the adjusting means being adjusted such that the weight of the additive in the supply line between the connecting line and the reservoir is sufficient, when present, to create a vacuum within the chamber sufficient to operate the switch against the biasing means.
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Accused Products
Abstract
A visual or audible indicator to indicate the absence of an additive ordinarily added to the rinse or wash water of a commercial dishwashing machine is disclosed. The dishwashing machine includes a separate reservoir containing an additive, a supply line connecting the reservoir to the point within the dishwashing machine where the additive is normally added, and a pump in the supply line for pumping the additive from the reservoir through the supply line. The pump includes a check-valve for retaining the additive in the supply line when the pump is not pumping. The indicator includes a vacuum operated switch and a connecting line connecting the vacuum operated switch to the supply line between the additive reservoir and the pump. The pump, switch, and connecting line are physically located above the maximum possible level of additive within the additive reservoir. The vacuum operated switch is adjusted such that the weight of the additive in the supply line between the connecting line and the reservoir is sufficient, when present, to create the vacuum necessary to operate the switch. The indicator is specifically designed so as to be easily added to preexisting commercial dishwashing machines with the minimum of alteration to the preexisting equipment.
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Citations
6 Claims
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1. In a dishwashing machine comprising a reservoir for containing an additive, a supply line connecting the reservoir to a point within the dishwashing machine where the additive is normally added, a pumping means in the supply line for pumping the additive from the reservoir to said point, the pumping means including a check-valve means for retaining the additive in the supply line when the pumping means is not pumping, and control means for controlling the pumping means, the improvement which comprises:
a vacuum operated switch and a connecting line connecting the vacuum operated switch to the supply line between the reservoir and the pumping means, the pumping means, switch and connecting line being physically located above the maximum possible level of additive in the reservoir, the vacuum operated switch comprising at least one pair of electrical contacts, a chamber opening only to the connecting line, one wall of the chamber defining a diaphragm moveable with respect to the remaining portion of the chamber, biasing means for biasing the position of the diaphragm to a preselected position, adjusting means for adjusting the biasing means and connector means for connecting the diaphragm to a moveable portion of the at least one pair of electrical contacts, the adjusting means being adjusted such that the weight of the additive in the supply line between the connecting line and the reservoir is sufficient, when present, to create a vacuum within the chamber sufficient to operate the switch against the biasing means. - View Dependent Claims (2, 3, 4, 5, 6)
Specification