This class and Class 318, Electricity: Motive Power Systems
are the generic loci for systems of electrical control of electric
motors. See Lines With Other Classes, below, for a further explanation
of this line.
Note: This class is being developed in stages from old Class
318, Electricity: Motive Power Systems. As other sections of Class
318 are reclassified, they will be added hereto.
TYPES OF MOTORS
Note: At the present stage of development of this class, only
the following types of motor are included.
1. Direct Current (DC) Commutating Motor: An electric motor
designed to operate on direct current and having a commutator electrically
connected to a winding of the motor.
MODES OF MOTOR CONTROL
Note: At the present stage of development of this class, only
the following modes of motor control are included.
1. Acceleration Control: Controlling the rate of change of
speed of an electric motor either (a) from zero speed to some running
speed, or vice versa, or (b) from one running speed to another running
speed by variation of the electric power input to the motor. Acceleration
control includes deceleration control.
2. Deceleration Control: Controlling the rate of change of
speed of an electric motor from a first running speed to a second
(lower) running speed, including zero speed, by variation of the
electric power input to the motor.
3. Running Speed Control: Controlling an electric motor so
as to maintain a particular substantially constant running speed.
CLASS ORGANIZATION AND SEARCH PHILOSOPHY
This class has been structured according to a new classification
philosophy known as "Concept Capture Classification" (CCC
or 3C). This type of classification facilitates a new computer-based
search method while continuing to support all traditional uses of
the classification of patents.
Organizational Structure - The class consists of two complementary
classification schedules:
1. A hierarchical schedule of subclasses (numbered from 800
to 860). The hierarchy of these subclasses follows all the rules
that apply throughout the Manual of Classification. These subclasses
are designed to accommodate, in general, the claimed subject
matter in the patents. They differ from subclasses elsewhere in
the Manual only in that they are somewhat broader and tend to contain
fewer disclosure-based cross-reference copies.
2. A "term list," or schedule of Art Collections.
This list is an indexing scheme with little hierarchy. These Art Collections
are much like other Art Collections throughout the Manual of Classification
except that care has been taken to place copies of each patent in
Class 388 into each and every Art Collection for which that patent has
a significant disclosure. In other words, the "concepts" disclosed
in each patent are "captured" for later reference
by placing cross reference copies into all the appropriate art collections,
thus the name "Concept Capture Classification."
METHOD OF CLASSIFYING NEWLY ISSUED PATENTS
When a new patent is issued in this class, copies should be
placed in all appropriate subclasses of the hierarchical schedule
as required by the claims. Further copies should be placed in all
appropriate (according to disclosure) art collections in order to
capture as much information about the patent as possible for future
reference. Although cross references based on the disclosure
but not the claims may be placed in the regular subclasses, they
should be limited as much as possible to the Art Collections.
SUGGESTED SEARCH STRATEGIES
A traditional search of paper copies may be conducted in the
same way as with any other class by selecting subclasses from among
those numbered subclasses 800-860, and then looking at each patent
in each subclass chosen. This approach may also be used on the "Automated
Patent System" (APS) with limitation that only those patents
more recent than 1975 are available for text display.
A computer-aided search (or "CCC Search")
may be conducted by searching a collection of subclasses and Art
Collections combined using the logical operations of the APS or
of the "Classification and Search Support Information System" (CASSIS),
CD/ROM version. In either of these systems one would compose
a search statement that says, for example, "Give me a list
of all patents which are in subclass 811 and art
collections (902 and 903 and 917)." To appear on the output
list a patent would have to have a copy in all of the subclasses chosen.
A somewhat less restrictive search statement might be used, as for
example, "Give me a list of all patents which are in subclass
811 and art collections (902 or 903 or 917).
In each of the search examples (811 and 902 and 903 and 917;
and 811 and 902 or 903 or 917) note that the art collections
(902, 903 and 917) are used as tools to search the subclass (811).
In other words the subclass 811 is the true location of the patent
but it resides there with many other patents of the same proximate
function. Traditionally, it has been necessary to look at all patents in
subclass 811 during a search and make judgments "on the
spot" as to their relevancy to a given search condition.
With a CCC search, one enters the search condition into the computer
in terms of which art collections are chosen, then the computer
selects from subclass 811 only those which are relevant to the given
conditions. In this way the searcher, hopefully, views fewer patents which
are more relevant to his search and he does not miss "hidden" or "implicit" disclosures.
An experimental computer-aided "CCC search" with specialized
output is available on the CASSIS CD/ROM machines in many
Patent Depository Libraries. These machines are programmed to give
a search of up to three subclasses using up to six art collections.
e.g., Search (811 or 819 or 831) and (902 or 903 or ... or 937)
Note. This search treats the three subclasses as separate searches
and prints the lists of "hits" separately for
each. The output is in the form of a graph with patent number as
vertical axis and art collections as horizontal axis. For each patent
found as a "hit" a line is printed giving the patent
number, which subclass it is in, and which art collections (of those
entered) it is in. If the patent is in one subclass and one art
collection (only) it is considered a "2-way hit",
if it is in one (or more) subclass(es) and all six art collections
it is considered a "7-way hit" and is flagged
accordingly. Obviously, "7-way" hits share more
features with the search statement than "2-way" hits.
This special output offers the important advantage of not only identifying
relevant patents, but of indicating just what is relevant about
each included patent.
SECTION II - LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
Where an electric motor control system is claimed in combination
with a load device and the load device is claimed either (1) in
general terms only (e.g., "load device", "variable
load", "means actuated by motor", etc.)
or (2) in specific terms, but by name only (e.g., "vehicle", "rolling
mill", "gearing", etc.), classification is
in this class (388) or in Class 318, Electricity: Motive Power Systems.
Where significant structure of a load device is claimed in
combination with a motor control system, classification is with
the load device.
Examples of classes which provide for the combination of significant
load device structure and motor control include: Class 62, Refrigeration;
Class 180, Motor Vehicles; Class 187, Elevator, Industrial Lift
Truck, or Stationary Lift for Vehicle; Class 219, Electric Heating; Class
244, Aeronautics; Class 250, Radiant Energy; Class 290, Prime-Mover
Dynamo Plants; Class 322, Electricity: Single Generator Systems;
Class 360, Dynamic Magnetic Information Storage or Retrieval; Class
414, Material or Article Handling; and Class 417, Pumps.
Elevator, Industrial Lift Truck, or Stationary Lift
for Vehicle,
subclasses 289+ for an elevator with an electric drive motor controlled
by means having an electric component.
Automatic Temperature and Humidity Regulation, appropriate subclasses for temperature and humidity regulating
systems which include an electric motor, particularly
subclasses 74+ for electric motor actuated systems.
Prime-Mover Dynamo Plants,
subclasses 9+ for prime-mover dynamo plants including electric
traction motors; subclasses 10+, 22+, 30, 31,
36+, 38, 46, 47 and 48 for electric motor starters for
prime-mover dynamo plants.
Electrical Generator or Motor Structure, appropriate subclasses for generic structure of electric
motors, particularly
subclass 189 for variable length or tapped windings.
Electricity: Single Generator Systems, electric motor systems are found throughout the class both
as driving means for a generator and as a control therefor. See
particularly
subclass 16 for electric motor driven generator systems having
simultaneous control of motor and generator; subclass 39 for electric
motor driven generator systems having electric motor control; subclasses
70, 71, 80 and 84 for generator control systems employing electric
motor systems therein. See section IV of the class definition of
Class 322.
Electricity: Power Supply or Regulation Systems,
subclass 340 for electric motor systems which control transformer
tap changing; subclass 364 for electric motor systems controlled impedance
selection systems; and appropriate subclasses throughout the class
for electric motor actuated or controlled phase control systems.
Oscillators, appropriate subclasses for oscillators, per se, particularly
subclasses 1+ for tunable oscillators of the automatic frequency
stabilizing type; and subclasses 48, 90 and 177+ for oscillators
having means for setting or controlling the frequency of a generated
wave of the oscillator by varying a frequency determining element
of the oscillator.
Electricity: Electrical Systems and Devices,
subclasses 23+ for motor protection circuits which cause shut-down
of the motor when predetermined conditions are met or exceeded; and
subclasses 139+ for control circuits for relays and other
electromagnetic-magnetic devices.
Data Processing: Generic Control Systems or Specific
Applications,
subclasses 1 through 89for generic digital data processing control systems.
SECTION IV - GLOSSARY
ANALOG
Of or pertaining to the general class of devices or circuits
in which the output varies as a continuous function of the input
(cf., "digital" below).
ANALOG CONTROL
A control circuit utilizing analog, as opposed to digital, signals.
ARMATURE
The moving element in an electromechanical device such
as the rotating part of a generator or motor, the movable part of
a relay, or the spring mounted portion of a bell or buzzer.
BRUSH
A piece of conductive material, usually carbon or graphite,
which rides on the commutator of a motor and forms the electrical
connection between the motor and a power source.
CLOSED LOOP CONTROL
A method of control in which the power input of a motor
is adjusted by a control circuit which compares a reference signal
with a feedback signal proportional to an output parameter (e.g.,
speed) of the motor to modify the power input of the motor so as
to achieve or maintain some desired operating condition of the motor
(e.g., constant running speed).
COMMUTATOR
The part of a motor armature to which the armature windings
are connected. It consists of a set of conductors arranged about
the rotation axis of the armature and insulated from the axis and
from one another. A set of stationary contacts, called "brushes" ride
on the outer face of the conductors and thereby connect the armature windings
to a power source.
COUNTER EMF
A voltage developed in an inductive circuit (e.g., in
an armature winding) by an alternating or pulsating current. The
polarity of this voltage is at every instant opposite that of the
applied voltage.
DIGITAL
Of or pertaining to the general class of devices or circuits
in which the output varies in discrete steps (cf., "analog" above).
DIGITAL CONTROL
A control circuit utilizing digital, as opposed to analog, signals.
ELECTRIC MOTOR
A machine which transforms electrical energy into mechanical
work. Note: For a description of each of the several types of electric
motor, see section IA above.
FEEDBACK
The return of energy from the output of a motor to the input
for the purpose of controlling the input so as to achieve or maintain
a desired output condition.
FIELD WINDING
A coil of insulated wire which produces a magnetic field in
the space occupied by the motor armature.
LOAD
That device, or system, which is the recipient of the mechanical
work output of an electric motor.
MICROPROCESSOR
A circuit which can be programmed with stored instructions
to perform a variety of functions, which functions may include,
for example, one or more modes of motor control.
MOTOR CONTROL
A system or device (usually an electrical circuit) which causes
one or more of the operating parameters of a motor to be held constant
or to be changed in a predetermined way. Note: For a description
of each of the several modes of motor control, see the class definition above.
OPEN LOOP CONTROL
A method of control in which the power input to a motor is
varied so as to achieve a desired running condition (e.g., constant
running speed) without the use of feedback.
PHASE LOCKED LOOP
A closed loop circuit in which the output signal is compared
to a reference signal and any phase difference between the two signals
is used to adjust the output signal to "lock" it
to the phase of the reference signal.
CLOSED LOOP SPEED CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR:
This subclass is indented under the class definition. Subject matter wherein a signal proportional to the running
speed of a DC commutating motor (i.e., a feedback signal) is used
to regulate the input to the motor to maintain a constant running
speed.
Electricity: Motive Power Systems,
subclasses 400.01 through 400.41for closed-loop speed control system in synchronous
brushless (i.e., electronic commutating) motors.
This subclass is indented under subclass 800. Subject matter in which regulation of the running speed
of the motor is effected by digital, or a combination of analog
and digital, circuitry which controls the energizing of, (1) a field
winding of the motor, or (2) both a field winding and an armature
winding.
(1)
Note. See the Glossary in the class definition for the terms "digital" and "analog".
This subclass is indented under subclass 800. Subject matter in which regulation of the running speed
of the motor is effected by analog circuitry which controls the
energizing of, (1) a field winding of the motor, or (2) both a field winding
and an armature winding.
(1)
Note. See the Glossary in the class definition for "analog."
This subclass is indented under subclass 803. Subject matter wherein energy is applied to the motor in
the form of a series of pulses and the running speed of the motor
is controlled by varying the width of the pulses or by periodic interruption
of the pulses.
This subclass is indented under subclass 803. Subject matter wherein the control circuit functions by
determining the phase or frequency relationship between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
This subclass is indented under subclass 803. Subject matter wherein the control circuit functions by
determining the voltage or current relationship between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
This subclass is indented under subclass 803. Subject matter wherein running speed is controlled by selecting
the windings of the motor field, or armature, or both, which receive
energization.
This subclass is indented under subclass 800. Subject matter in which regulation of the running speed
of the motor is effected by digital, or a combination of analog
and digital, circuitry which controls the energization of an armature
winding only.
(1)
Note. See the Glossary in the class definition the terms "digital" and "analog".
This subclass is indented under subclass 809. Subject matter wherein energy is applied to the motor in
the form of a series of pulses and the running speed of the motor
is controlled by varying the width of the pulses or by periodic interruption
of the pulses.
This subclass is indented under subclass 809. Subject matter wherein the control circuit functions by
determining both the phase and the frequency relationships between
a reference signal and a feedback signal and by applying an adjustment,
based on this relationship, to the motor input.
This subclass is indented under subclass 809. Subject matter wherein the control circuit functions by
determining the phase relationship between a reference signal and
a feedback signal and by applying an adjustment, based on this relationship,
to the motor input.
This subclass is indented under subclass 809. Subject matter wherein the control circuit functions by
determining the frequency relationship between a reference signal
and a feedback signal and by applying an adjustment, based on this
relationship, to the motor input.
This subclass is indented under subclass 809. Subject matter wherein the control circuit functions by
determining the voltage or current relationship between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
This subclass is indented under subclass 800. Subject matter in which regulation of the running speed
of the motor is effected by analog (only) circuitry which controls
the energization of an armature winding only.
This subclass is indented under subclass 816. Subject matter wherein energy is applied to the motor in
the form of a series of pulses and the running speed of the motor
is controlled by varying the width of the pulses or by periodic interruption
of the pulses.
This subclass is indented under subclass 816. Subject matter wherein the control circuit functions by
determining the phase or frequency relationship between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
This subclass is indented under subclass 816. Subject matter wherein the control circuit functions by
determining both the voltage and current relationships between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
This subclass is indented under subclass 816. Subject matter wherein the control circuit functions by
determining the voltage relationship between a reference signal
and a feedback signal and by applying an adjustment, based on this
relationship, to the motor input.
This subclass is indented under subclass 816. Subject matter wherein the control circuit functions by
determining the current relationship between a reference signal
and a feedback signal and by applying an adjustment, based on this
relationship, to the motor input.
OPEN LOOP SPEED CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR:
This subclass is indented under the class definition. Subject matter wherein a derived reference signal is applied
to the input circuit of a commutating DC electric motor to regulate
the running speed of the motor.
Electricity: Motive Power Systems,
subclasses 400.01 through 400.41for closed-loop speed control system in synchronous
brushless (i.e., electronic commutating) motors.
This subclass is indented under subclass 825. Subject matter in which regulation of the running speed
of the motor is effected by circuitry which controls the energization
of, (1) a field winding of the motor, or (2) both a field winding
and an armature winding.
(1)
Note. In this subclass, and the subclasses indented hereunder,
the control circuitry may function in either a digital mode or an
analog mode or a combination of digital and analog modes. See the
Glossary in the class definition for the terms "digital" and "analog."
This subclass is indented under subclass 825. Subject matter in which regulation of the running speed
of the motor is effected by digital, or a combination of analog
and digital, circuitry which controls the energization of an armature
winding only.
(1)
Note. See the Glossary in the class definition for the terms "digital" and "analog."
This subclass is indented under subclass 828. Subject matter wherein energy is applied to the motor in
the form of a series of pulses and the running speed of the motor
is controlled by varying the width of the pulses or by periodic interruption
of the pulses.
This subclass is indented under subclass 825. Subject matter in which the regulation of the running speed
of the motor is effected by analog (only) circuitry which controls
the energization of an armature winding only.
This subclass is indented under subclass 830. Subject matter wherein energy is applied to the motor in
the form of a series of pulses and the running speed of the motor
is controlled by varying the width of the pulses or by periodic interruption
of the pulses.
This subclass is indented under subclass 830. Subject matter wherein the control circuit functions by
adjusting the frequency of DC power pulses applied to the motor
input.
This subclass is indented under subclass 830. Subject matter wherein the control circuitry functions by
adjusting the amplitude of the voltage or current which is applied
to the input circuit of a motor.
This subclass is indented under subclass 830. Subject matter wherein running speed is controlled by selecting
the windings of the armature which receive energization.
This subclass is indented under subclass 830. Subject matter wherein running speed is controlled by altering
the structural relationship of motor components.
This subclass is indented under subclass 835. Subject matter wherein the structure is altered by (a) repositioning
one or more commutator brushes or, (b) changing the number of brushes in
use.
This subclass is indented under subclass 830. Subject matter wherein running speed is controlled by means
of a mechanical switch which operates repetitiously at a predetermined
rate.
This subclass is indented under subclass 830. Subject matter including means for selecting two or more
speeds.
(1)
Note. Speed selection may be either (1) continuous (e.g.,
using a potentiometer), or (2) discontinuous (e.g., using a multi-position
mechanical switch).
This subclass is indented under subclass 838. Subject matter wherein running speed is controlled by insertion
of an impedance device and provision is made for selecting a device
from among several having different impedance values.
(1)
Note. Impedance devices include resistors, capacitors, and
inductors.
CLOSED LOOP ACCELERATION CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR:
This subclass is indented under the class definition. Subject matter wherein a signal proportional to the running
speed of a DC commutating motor (i.e., a feedback signal) is used
to regulate the input to the motor to control the rate of change
of speed (i.e., acceleration of deceleration) or the motor.
(1)
Note. In this subclass, and the subclasses indented hereunder,
the control circuitry may function in either a digital mode or an
analog mode or a combination of digital and analog modes. See the
Glossary in the class definition for "digital" and "analog."
Electricity: Motive Power Systems,
subclasses 400.01 through 400.41for closed-loop acceleration control system in
synchronous brushless (i.e., electronic commutating) motors.
This subclass is indented under subclass 842. Subject matter in which regulation of the acceleration of
the motor is effected by circuitry which controls the energization
of, (1) a field winding of the motor, or (2) both a field winding and an armature winding.
This subclass is indented under subclass 842. Subject matter in which regulation of the acceleration of
the motor is effected by circuitry which controls the energization
of an armature winding only.
This subclass is indented under subclass 844. Subject matter wherein the control circuit functions by
determining the voltage or current relationship between a reference
signal and a feedback signal and by applying an adjustment, based
on this relationship, to the motor input.
OPEN LOOP ACCELERATION CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR:
This subclass is indented under the class definition. Subject matter wherein a derived reference signal is applied
to the input circuit of a commutating DC electric motor to regulate acceleration
or deceleration of the motor.
(1)
Note. In this subclass, and the subclasses indented hereunder,
the control circuitry may function in either a digital mode or an
analog mode or a combination of digital and analog modes. See the
Glossary in the class definition for "digital" and "analog."
Electricity: Motive Power Systems,
subclass 400.42 for closed-loop acceleration control system in
synchronous brushless (i.e., electronic commutating) motors.
This subclass is indented under subclass 848. Subject matter in which regulation of the acceleration of
the motor is effected by circuitry which controls the energization
of, (1) a field winding of the motor, or (2) both a field winding
and an armature winding.
This subclass is indented under subclass 849. Subject matter wherein acceleration of the motor is controlled
by a mechanical device which makes and breaks the motor circuit according
to a predetermined pattern.
This subclass is indented under subclass 849. Subject matter wherein acceleration of the motor is controlled
by increasing or decreasing the amount of resistance in the motor
circuit.
This subclass is indented under subclass 848. Subject matter in which regulation of the acceleration of
the motor is effected by circuitry which controls the energization
of an armature winding only.
This subclass is indented under subclass 853. Subject matter wherein the control circuitry functions by
adjusting the amplitude of the voltage or current applied to the
input circuit of the motor.
This subclass is indented under subclass 853. Subject matter wherein the control circuit includes a variable
impedance device or a set of fixed impedance devices which are selectable
by switches, or other means.
(1)
Note. Variable impedance devices include potentiometers, variable
inductors, and variable capacitors.
This subclass is indented under subclass 855. Subject matter wherein the impedance device is a variable
resistor, or a set of fixed resistors of different values - including
zero resistance (short circuit).
This subclass is indented under subclass 856. Subject matter wherein resistance are inserted by a mechanical
device which functions according to a predetermined pattern.
This subclass is indented under subclass 855. Subject matter wherein the impedance value of the motor
circuit is selected or varied manually.
CROSS-REFERENCE ART COLLECTIONS
NOTE: No paper files exist for these art collections. They
are to be used for APS searching. An effective way to use them is
to cross search an art collection with a range of subclasses in
the schedule of this class, (e.g., Use the search statement "S
388820/CCLS AND 388902/CCLS" to find
closed loop analog speed control by frequency modification combined
with compensation for voltage fluctuations).
This subclass is indented under the class definition. Electronic cross-reference art collection including miscellaneous
aspects of motor control.
(1)
Note. This art collection is intended to serve as a repository
for art which an examiner wishes to collect as he would do in creating
an "unofficial digest". When sufficient art embodying
a given creative concept is assembled here, an official art collection
will be established for that concept.
Art collection of systems which periodically sample an output
parameter and generate a feedback signal based on the periodic sample.
(1)
Note. Systems which continuously monitor an output parameter,
and which generate a continuously varying feedback signal therefrom,
are not cross-referenced here.
Art collection of systems which apply one or more corrective
signals to a motor input drive signal in order to compensate for
operational irregularities.
(1)
Note. "Operational irregularities" include,
but are not limited to: temperature changes, frequency drift, voltage fluctuations,
friction, structural changes.
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