Continuous pumping system

DETAILED DESCRIPTION The invention provides a spring actuation arrangement for a storage piston and cylinder device in a pumping system whereby the spring of the device remains at a relatively constant length when pumping product for keeping the pressure on the product relatively constant and thus keeping the stream or spray issuing from the pumping system relatively constant.
The spring tends to extend when pumping air during priming of the pump so that low pressure air can escape from the pumping system relatively easily, thus aiding in priming the pumping system.
The invention also includes a novel vent structure provided by a double seal arrangement which makes it possible to mold a mounting ring and cylinder of the main piston and cylinder device of the pumping system in one piece of plastic.
The vent arrangement prevents product from emerging from the container when the container is shaken or squeezed.
A novel double straining arrangement is also provided wherein product is strained where it leaves a dip tube emerging from the container, and is strained again at an outlet opening arrangement in a storage cylinder of the pumping system.
Accordingly, it is an object of the present invention to provide a pumping system in which a part of the pressurized product is stored at a relatively constant pressure for keeping a stream or spray emerging from the pumping system relatively steady.
Another object of the invention is to provide a one piece mounting ring and cylinder unit for a pumping system.
Another object of the invention is to provide a novel strainer arrangement for a pumping system.
Another object of the invention is to provide an improved vent structure for a pumping system which is compatible with a one piece mounting ring and cylinder arrangement.
Another object of the invention is to provide strainers for a pumping system which are self-cleaning.
Other objects of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views