Patent ID: 6360473
Filing Date: 2002-03-26
Classification: F16K,F41B

Abstract:
An adjustable aperture forming mechanism for controlling flow of medium therethrough, comprising;an aperture body having a front end and a back end and defining a through-hole having an axis extending from said front end to said back end, said through-hole having an internal tapered portion; a continuous elastic ring which lies in said through-hole adjacent to said internal tapered portion; and a pusher movably mounted on said aperture body, such that, when said pusher moves in a first direction along said axis, it exerts pressure on said elastic ring, forcing said ring to move linearly along said axis into said tapered portion to effectively reduce the inside diameter of said elastic ring, thus decreasing the effective diameter of the through-hole, and, when said pusher moves in the opposite direction, it releases pressure on said elastic ring, permitting the ring to return to a larger diameter portion of said tapered portion, where the elastic ring returns to a larger inside diameter, thereby enlarging the effective diameter of the through-hole.