Source: {"pile_set_name": "USPTO Backgrounds"}

The present invention relates to devices for dispensing toilet bowl treating chemicals (e.g. soaps, disinfectants, sanitizers deodorizers, fragrances, colorants, etc.). More specifically it relates to such devices that allow a consumer to direct when the chemicals will be dispensed into the toilet bowl water, while minimizing the need for consumers to scrub the toilet bowl.
Toilet bowls require care to prevent the buildup of unsightly deposits, to reduce odors and to prevent bacteria growth. Originally toilet bowls were cleaned, deodorized and/or otherwise treated by manual scrubbing with a liquid or powdered cleaning/sanitizing agent that was added to the bowl water by hand. This required manual labor to keep the toilet bowl clean.
To reduce or in some cases eliminate the need for manual scrubbing, various automatic toilet bowl cleaning systems have been created. One type of system delivers the cleaning chemical by adding it to the flush water while the flush water was still stored in the toilet tank. Some embodiments of this type of system add the chemical to the flushing cycle in liquid form. Others place a block of cleaning chemical in the toilet tank, to slowly dissolve over several weeks or longer.
However, a system which relies on adding the chemical to the storage tank typically requires the consumer to lift a tank lid in order to install the device and/or to add a new charge/block of cleaning chemical. Also, with some of such systems, precise control over the quantity of chemical to be delivered is difficult. For example, different water hardness from the supply may cause different cleaning blocks to dilute at different rates. Further, when the chemical is placed in the storage tank the cleaning chemical must be compatible for long-term contact with some of the valving present in the toilet tank, which may impose some limitations.
An alternative type of system hangs a dispenser adjacent and/or immediately under the toilet bowl rim. Water flowing from the rim washes over the dispenser, thereby triggering dispensing of the stored chemical directly into the bowl water. However, some consumers prefer not to have the ornamental exterior of their toilet disrupted by the presence of a hook hanger. Still others are reluctant to maintain such dispensers given that they are so close to the waste bowl, and the consumers don't want to reach near that area.
In any event, such systems are designed to dispense in response to each flush. In some situations where increased amounts of flushing are occurring (e.g., a curious child, a large number of guests, a family's return from a long car-trip) cleaning chemicals may not be necessary after every flushing. Thus, some of these systems use up more cleaning chemicals than is actually needed.
There have been attempts to associate toilet bowl chemical dispensers with the lids or other coverings of toilets, or near them. See e.g. U.S. Pat. Nos. 713,978, 749,963, 979,386, 988,178, 3,840,914, 4,216,553, 4,819,276 and 6,745,417, and U.S. patent application publication 2006/0097189. However, these systems suffer from many of the deficiencies noted above. For example, it is typical with many of such systems to have dispensing occur with every lid movement, regardless of need.
It can therefore be seen that improvements are desired with respect to toilet bowl cleaning assemblies that dispense cleaning chemicals.