1. Field of the Invention
The invention relates to an apparatus for drawing a viscous product such as toothpaste from a container and dispensing the product. More particularly this invention relates to a product dispenser with a vacuum pump of piston-cylinder construction.
2. Description of the Related Art
Viscous products such as toothpaste have historically been dispensed from flexible tubes. When the tube is squeezed the product is extruded from a nozzle at the end of the tube. Dispensers have been developed to automate the dispensing process of viscous products; however, conventional dispensers suffer from several disadvantages, such as, for example, an ineffective dispensing valve. Typically, the tack of the product causes the product to stick to the dispensing valve. Consequently, the product sticks to the dispensing valve, dries out, is wasted, and creates a mess that requires frequent cleaning. Also, the quantity dispensed in conventional dispensers is not adjustable according to user preference. Clearly, people do not always prefer the same amount of product dispensed. In particular, toothpaste dispensers typically dispense an amount of toothpaste proportional to the size of the toothbrush head. Children, in particular, have a need to control the amount of toothpaste dispensed since a strong taste and concentration of the paste may cause the child discomfort or pain.
Thus, it can be clearly recognized that there is a need for an apparatus that allows a user to adjust the quantity of the product discharged according to user preference independent of other considerations, such as the size of a toothbrush. There is also a need for an apparatus that readily deposits the discharged product without leaving the discharged product on the dispenser valve. Additionally, there is a need for an apparatus that prevents sticking of deposited product to the dispensing apparatus so as to reduce waste, maintain a clean dispenser, and permit rapid dispensing of the product for a user.