Method and apparatus for adjusting either the flow area to a constant size mold gate or the area of a variable mold gate opening in order to control the flow of molten plastic to a mold cavity for the injection molding of plastic parts, such adjustment being made by rotating an outer rotary gate bushing...http://www.google.co.uk/patents/US5780077?utm_source=gb-gplus-sharePatent US5780077 - Adjustable mold gate for a hot probe member
