| 摘要 |
<p>A frictional blade assembly for grilles to be used in association with air ventilation systems wherein said assembly comprises a first thermoplastic support bar defining a stem, which stem defines a longitudinal axis, and having a plurality of coplanar abutments extending normal to one side of said axis, each of said abutments being more or less the same length and having an outer surface of uniform generally cylindrical shape and having more or less the same diameter, said abutments being formed integrally as part of said support bar, a plurality of blades, each of said blades defining a first end and a second end and being of uniform cross-sectional shape and size along its length, each said blade defining a generally streamline-shaped tube, said tube defining a first edge, a second edge and an internal space, said internal space at said first edge being of generally circular cross-section over an arc of approximately 270.degree., said circular cross-section having a diameter of between 0.002" and 0.004" less than that of said abutments, said first end of said blades being rotatably attached to respective said abutments by inserting a said abutment into said internal space at the first edge of a said blade, whereby a frictional fit between each said abutment and a respective said blade is obtained, and, a second thermoplastic support bar defining a stem, which stem defines a longitudinal axis, and having a plurality of coplanar abutments extending normal to one side of said axis, said second bar being affixed to said second ends of said blades at said first edges, whereby said blades may be rotated relative to said first and second bars against a frictional resistance.</p> |
