Donald Paul Martin's Patents:

Patent numbers: 4776832, 4300847, 4300845, 4282472, 4282471, 4037705, 4037705, 4037705, 3990559
Centrifuge having multiple induction motors for rotating objects about a second axis
Patent number: 4776832
Abstract: An improved centrifuge, including a main wheel for rotating objects to be subjected to
centrifugal force about a main axis of rotation, is disclosed. Such objects are simultaneously rotated
about a second axis of rotation from a first to a second position, and the centrifuge is improved by the
inclusion therein of multiple reversing induction motors including a stationary stator and multiple
induction rotors attached to the main wheel that eliminate electrical slip rings or mechanical linkages as
controls for effecting the rotation of the objects from the first to the second position.
Type: Grant
Filed: December 10, 1986
Date of Patent: October 11, 1988
Assignee: Abbott Laboratories
Inventors: Donald P. Martin, T. Edward Black, Vidas P. Kazlauskas

Teleprinter having single belt carriage and ribbon drive system
Patent number: 4300847
Abstract: A teleprinter includes a carriage for conveying a dot matrix-type print head along an
operating path parallel to a print-receiving surface. The carriage is mounted on parallel-spaced support
rods by means of spaced bearings slidably engaged to one of the support rods, and a pair of
perpendicularly-aligned guide rollers which engage the other guide rod. The carriage is advanced by a
drive belt which extends along the carriage operating path and is attached to the carriage at either end.
A stepper motor coupled to one of the pulleys drives the belt to position the carriage. A removable
cartridge on the carriage contains an inked ribbon which is advanced with movement of the carriage by
a drive gear engaged to the drive belt. A unidirectional clutch prevents the inked ribbon from moving
in a reverse direction during carriage return.
Type: Grant
Filed: May 14, 1979
Date of Patent: November 17, 1981
Assignee: Qwint Systems, Inc.
Inventors: Robert C. Hoffman, Richard H. Kruse, Donald P. Martin
Dot matrix print head
Patent number: 4300845
Abstract: A dot matrix-type print head for forming a character-defining array of individual dots on a
print-receiving surface includes a plurality of parallel-spaced print wires arranged in a vertical plane
perpendicular to the print receiving surface. The print wires are individually actuated by respective
actuator assemblies which each include a stationary portion consisting of an end plate, a bobbin, a
solenoid winding, and a spring, and a movable portion consisting of a magnetic armature attached to
the associated print wire. Upon energization of the solenoid winding the resulting magnetic flux
displaces the magnetic armature and causes the print wire to impact the print-receiving surface.
Type: Grant
Filed: May 14, 1979
Date of Patent: November 17, 1981
Assignee: Qwint Systems, Inc.
Inventors: Donald P. Martin, Robert C. Hoffman, Richard H. Kruse
Digital generation and control of variable phase-on motor energization
Patent number: 4282472
Abstract: A control system for controlling a motor having a plurality of electromagnetic field windings
adapted to be separately energized by switching circuitry to control rotation of a rotor in the motor.
Digital circuitry generates a plurality of logic signals, one for each respective motor field winding to
cause the switching circuitry to energize the field windings in a two phase on mode, a one phase on
mode, or in one of a plurality of fractional phase on modes. A signal command source provides a
plurality of digital signals to select or gate the desired phase on energization mode of the field
windings in response to a feedback signal derived from detecting rotary movement of the rotor.
Related methods of controlling a multi-phase motor with digitally generated variable phase modes are
also disclosed.
Type: Grant
Filed: May 14, 1979
Date of Patent: August 4, 1981
Assignee: Qwint Systems, Inc.
Inventor: Donald P. Martin
Control system for a multi-phase motor
Patent number: 4282471
Abstract: A motor control system for use in a high speed teleprinter or the like for controlling the
rotational position and movement of a rotor, and apparatus driven by the rotor, by detecting back
EMF induced into an unenergized field winding by rotational movement of the rotor. The output and
input terminals of a first amplifier responsive to a first motor control signal, and a second amplifier
responsive to a second motor control signal, are reactively coupled such that the amplifiers respond to
either motor control signal to develop a signal simulating the signal into an unenergized winding of the
motor due to mutual inductance with an energized winding. A differential voltage comparator
provides a feedback signal indicative of motor performance upon comparing the simulated signal with
the signal actually induced.
Type: Grant
Filed: May 14, 1979
Date of Patent: August 4, 1981
Assignee: Qwint Systems Inc.
Inventors: Mitchell S. Budniak, Donald P. Martin
Descender printing system for dot matrix printer
Patent number: 4037705
Abstract: A descender printing system for a dot matrix printer, comprising a detector for detecting
code words representative of descender characters (lower case letters, punctuation, fractions, etc.)
prior to printing, and shift means for actuating the line feed mechanism of the printer to advance the
paper by two or more dot heights and thereby print the descender elements of such characters below
the normal base line. The shift means again actuates the line feed mechanism to return the paper to its
original position when the next non-descender character is to be printed.
Type: Grant
Filed: April 9, 1976
Date of Patent: July 26, 1977
Assignee: Extel Corporation
Inventors: Donald P. Martin, Richard G. Ryan
Method and apparatus for multiple speed print rate control for dot matrix printer
Patent number: 3990559
Abstract: A method and apparatus for controlling the print rate of a column-sequential dot matrix
printer actuated by an input signal comprising a sequence of code words occurring at a given maximum
input rate, a print head and a print head drive operating at a speed determined by the frequency of a
print rate timing signal, and a multi-stage FIFO input storage register. A multiplicity of
constant-frequency print rate timing signals are generated, ranging in frequency from substantially
below to substantially above a normal print rate frequency Fn approximately matched to the input rate,
and a variable print rate timing signal progressively increasing in frequency from well below Fn to well
above Fn is also generated; these signals are applied to the printer in accordance with a predetermined
schedule, determined by the number of code words in storage at the beginning of each spacing
character cycle, and in accordance with a program affording relatively smooth acceleration and
deceleration of the print head.
Type: Grant
Filed: October 20, 1975
Date of Patent: November 9, 1976
Assignee: Extel Corporation
Inventors: Donald P. Martin, Richard G. Ryan