Image Number 2 for United States Patent #7255127.
A vacuum regulator and intermittent flow device are disclosed. Vacuum regulation is achieved via spring forces acting on a movable piston-tube assembly disposed within a regulator body having a cylindrical hollow interior. Vacuum is supplied to an input port and regulated vacuum is provided at an output port. Vacuum at the output is cut off when fluid flow is sufficiently restricted and the piston-tube assembly is urged in contact against a fluid flow aperture within the regulator body thereby blocking fluid flow. Multiple modes of operation are provided in the regulator by way of a three position mode knob that enables regulated vacuum, unregulated vacuum and an "off" mode of operation. The disclosed intermittent vacuum flow device is attached to the output of the vacuum regulator and enables timed cyclical on and off operation of vacuum regulation.