Martin Lessen

US Patent:

54549868, Oct 3, 1995

Filed:

Aug 4, 1994

Appl. No.:

8/286070

Inventors:

Martin Lessen - Rochester NY

International Classification:

B01D 4716

US Classification:

261 93

Abstract:

Improved mixing effectiveness in the mixing of a gas with a liquid suspension is achieved in a batch mixing system having a mixing tank with a hemi-toroidal tank bottom which extends between a radially inner neck portion of the tank to a radially outer cylindrical wall portion of the tank. The hemi-toroidal profile of the tank bottom has a monotonically increasing toroidal radius between the neck and wall portions. Disposed within the tank is an assembly including an axial flow impeller with pitched impeller blades, a stator adjacent to the impeller and having stationary stator blades of a pitch opposite to the pitch of the impeller blades, a shroud surrounding the radial periphery of both the impeller and the stator and a gas sparging means supported by the shroud. The arrangement of the assembly provides in conjunction with the hemi-toroidal tank bottom a substantially swirl-free laminar flow of the liquid suspension directed downwardly along the neck portion and along the tank bottom when the impeller is rotatably driven by a drive shaft.

US Patent:

54618983, Oct 31, 1995

Filed:

Dec 9, 1993

Appl. No.:

8/164385

Inventors:

Martin Lessen - Rochester NY

International Classification:

B21C 2502

US Classification:

72256

Abstract:

Method and apparatus for the extrusion of tubing, sheets and profile shapes, wherein shearing strains in the material being extruded through a die serve to orient the microstructures of the material so that its strength properties are improved in the direction transverse to the extruding direction.

US Patent:

50522612, Oct 1, 1991

Filed:

Jan 5, 1988

Appl. No.:

7/141329

Inventors:

Martin Lessen - Rochester NY

International Classification:

G10D 904

US Classification:

84389

Abstract:

Improved apparatus for providing a chromatic scale with accurate intonation for valved brass instruments is disclosed. Two embodimeents of the invention that compensate for the deficiencies of the valve systems of the prior art are described for both four and five valve systems. For four valves systems, a master valve is used to lower the pitch of the instrument by two tones, and for five valve systems, a master valve lowers the pitch by two and one-half tones. The invention, therefore, makes possible complete compensation over the range of the instrument and improved tone quality.