Patent ID: 7114525

Claim:
In combination, a restrictor and a pulsation-absorbing flexible pipe for a pressure fluid device, said restrictor comprising a generally cylindrical body having a central flow-through passage open at its opposite axial ends, said flow-through passage being constructed in the form of a venturi having a flow-direction-convergent inlet passage leading into a constant diameter throat passage that in turn leads into a flow-direction-divergent outlet passage, the configuration of said venturi inlet, throat and outlet passages being constructed and arranged with a shallow taper angle in said inlet and outlet passages and said throat passage having a relatively short axial length much less than that of either said inlet or said outlet passages and such that turbulence is minimized in said restrictor outlet passage and/or immediately downstream thereof, under the pressure and fluid flow conditions in which the restrictor is adapted to be used, said body having a cylindrical exterior surface with an outside diameter (O.D. dimension) generally ranging from about 10.033 mm down to about 8.76 mm, wherein the axial cross sectional configuration of the interior of the restrictor, as defined by said inlet, throat and outlet passages, is symmetrical about all axes, wherein the respective taper angle of said inlet and outlet passages is in the range of about 4° to about 15°, wherein the internal diameter dimension of said throat passage is in the range of about 2.64 mm to about 4.57 mm, wherein the axial length of said throat passage is in the range of about 0.76 mm to about 12.2 mm, wherein the maximum I.D. of said inlet passage at its inlet end is the same as that of said outlet passage at its outlet end and is about 7.493 mm, wherein the external surface of said restrictor is interrupted in its central region by a series of shallow grooves that define therebetween a series of equally spaced and equal axial length lands, the axial length dimension of each said groove being in the range of about 0.127 mm to about 1.651mm, the axial length dimension of each said land being in the range of about 0.76 to about 2.667 mm, and wherein the depth dimension of each said groove being in the range of about 0.127 mm to about 406 mm.