US PATENT CLASS 334
Class Notes
Current as of: June, 1999
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DEFINITION
Classification: 334/
This class includes:
(1) Tuners (as defined in the Glossary). In function the tuner serves to select and pass or reject a particular frequency from a signal presented to the tuned circuit while attenuating or suppressing the passage or rejection of any other frequency that may be present in the signal. Generally the tuner consists of an inductor and capacitor, one or both of which may be variable, connected together in such a manner as to form a resonant circuit. For classification here, some means must be present in the tuner to vary the mean resonant frequency of the tuner from one frequency to another. The means present in the tuner should be something more than just the incidental showing of a generalized variable impedance element, but should be some means which is included in the circuit for the express purpose of making the resonant circuit variable over a range of frequencies. This means usually is in the form of a specific variable impedance device, such as an inductor or capacitor, the variation of which changes the electrical parameters of the circuit thus causing a shift in resonance of the circuit. The means may, however, consist of two or more impedances of fixed value which are adapted to be switched or substituted into or out of the resonant circuit. Excluded are wave filters which are closely analogous in that they are designed to pass or reject a single frequency or band of frequencies. Wave filters, generally, have no provisions or means which are particularly designed for and meant to vary the mean frequency of the filter during operation of the filter unit in a radio circuit. The wave filter may have "trimmer" means which is designed to "peak" the response of the filter, but these trimmers are not meant to be used in varying the resonance frequency of the filter during the operation of the filter in an electrical circuit such as, for example, a radio receiver. A wave filter having trimmer means is usually adjusted prior to the installing of the filter in an electrical circuit.
The filter once adjusted is rarely, if ever, adjusted again unless the resonance characteristic of the filter requires some additional peaking. A circuit which has means to merely broaden or narrow the band which is being passed without varying or changing the means or center frequency to which the circuit is tuned does not amount to tuning but is considered a filter for classificaiton with wave transmission lines and networks (see References to Other Classes, below). However, a circuit which broadens or narrows the pass band and which also varies the mean or center frequency of a filter is considered a tuner.
(2) Included also are tuners with perfecting structure, such as a remote control circuit, a resonance indicator, tuner units with an electromagnetic operator, or tuners with automatic frequency centering circuits which are not otherwise classifiable.
(3) Also included are tuners combined with or incorporated in other structure and not elsewhere classifiable, such as a tuner combined with a tube socket or a special punched chassis. Also included are tuners combined with or incorporated in diverse nonelectrical devices and which combination is not classifiable elsewhere.
(4) Included also are tuners constructed as by the type of actuator used or from selected material so that the impedance values of the tuner changes particularly well in response to a particular condition or change in a particular condition such as current and/or voltage as, for example; a tuner using a saturable core type inductor; a tuner using a voltage responsive capacitor; or a tuner responsive to a magnetic field. Also included are tuners usually of the mechanically variable type together with a condition sensing actuator which changes the mechanical adjustment of the tuner in response to a condition or a change in condition. An example, of such a tuner is one having a heat sensitive actuator, or a tuner that is deformable as by compression by a weight or force.
(5) Subcombinations and components of tuners not otherwise classifiable, such as a resonance indicator, are classified in this class.
LINES WITH OTHER CLASSES
A. TUNERS CLASSIFIED ELSEWHERE: Certain circuits or devices which may be considered tuners are not classified here. See References to Other Classes, below, for tuned resonance type wave filters which may be referred to as a tuner and the resistor-capacitor circuits such as bridged-T, double-T or Weir Bridge networks, for example, which are sometimes referred to as tuners. Also see the Search Class notes for tunable resonators of the distributed parameter type in which there are no lumped impedance elements present and where only a single resonator
is used. The inclusion of a lumped impedance element in the resonant circuit or the coupling of two or more distributed parameter type units together to form a single tuner will result in classification in this class.
B. TUNERS COMBINED WITH OR INCORPORATED IN OTHER DEVICES:
As stated above, this class includes tuners combined with or incorporated in other structure not elsewhere classified. See Subclass References to the Current Class for tuners combined with various other devices and for tuners combined with or having shielding or housing means. The combination of a tuner with or in other structure or circuits is very common. A partial list of the classes and subclasses including this combination is given in References to Other Classes, below.
C. TUNER COMPONENTS AND SUBCOMBINATIONS:
Included in References to Other Classes, below, is the classification of the most common subject matter which may constitute a part or subcombination of a tuner.
D. DEVICES SIMULATING TUNERS:
See References to Other Classes, below, for wave filters, and resonators of the distributed parameter type.
E. MEASURING OR TESTING TUNERS
This class does not provide for either methods of or apparatus for measuring and testing tuners. If the measuring or testing is of a mechanical nature or not otherwise classified, classification is in Class 73, Measuring and Testing. See also the Search Notes in Class 73 for a more detailed field of search to measuring and testing devices and systems. If the measuring or testing involves determining the frequency or electrical properties of the tuner, classification is in Class 324, Electricity: Measuring and Testing, subclasses 600+.
SEE OR SEARCH THIS CLASS, SUBCLASS:
4, for magnetic field responsive tuners. 5+, for condition responsive tuners.
12+, for saturable core type tuners.
39, for tuners combined with various other devices.
40, for a lumped resistor element connected in a tuned circuit.
85, for tuners combined with or having shielding or housing means.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
40, Card, Picture, or Sign Exhibiting, for means for displaying information, the information that is displayed may be the position or channel to which a tuner is adjusted.
40, Card, Picture, or Sign Exhibiting, appropriate subclasses for means to indicate the position or band to which a tuner is positioned. (See "Tuner Components and Subcombinations, " above.)
73, Measuring and Testing, for measuring and testing devices generally. See "Measuring or Testing tuners", above.
74, Machine Element or Mechanism, 10+, for machine elements and mechanisms particularly adapted for mechanically rotating one or more shafts of electronic tuning devices into desired angular positions.
74, Machine Element or Mechanism,
10+, for tuners by name only combined with shaft operators for radio tuners. (See "Tuners Combined With or Incorporated in Other Devices" above)
74, Machine Element or Mechanism,
10+, for shaft operators which are particularly adapted for mechanically rotating one or more shafts of electronic tuning devices into desired angular positions, and subclasses 527+ for detents which are used in connection with fixed and movable members such as a tuner housing and shaft and which are especially adapted to check or arrest the motion of the movable element. Such detents are commonly used to properly position the tuner to some particular frequency or band of frequencies. (See "Tuner Components and Subcombinations," above.)
84, Music, appropriate subclasses for musical devices that may use tuned circuits, especially
671, 746 for electrical tone generation by the use of tuned sound generators or resonators.
116, Signals and Indicators,
241+, for indicators attached to or associated with some movable or adjustable radio tuning devices to indicate the movement, adjustment or position of such devices. Usually the indicator is of the movable-pointer and scale type.
174, Electricity: Conductors and Insulators,
35+, for shields and screens, per se, and subclasses 50+ for
electrical boxes and housings, per se. 200, Electricity: Circuit Makers and Breakers, appropriate subclasses for electrical make and break switch, per se, which may be used in a switch type tuner.
200, Electricity: Circuit Makers and Breakers, appropriate subclasses for circuit makers and breakers of the switch type which may be used in combination with several inductors and/or capacitors to form a switch type tuner. (See "Tuner Components and Subcombinations, " above)
219, Electric Heating,
750, for microwave heating with tuned circuits.
219, Electric Heating,
600+, for inductive heating, note subclass 750 for microwave heating with tuned circuits, and subclasses 764+ for capacitive dielectric heating. (See "Tuners Combined With or Incorporated in Other Devices,")
250, Radiant Energy,
250, for wave meters utilizing tuners as an element thereof. (See "Tuners Combined With or Incorporated in Other Devices," above.)
307, Electrical Transmission or Interconnection Systems,
105, for electrical transmission or interconnection systems with harmonic filters which may be adjustable.
315, Electric Lamp and Discharge Devices: Systems,
5.46+, for cathode- ray tube circuits in which the cathode ray passes through plural hollow distributed parameter devices that are tunable; subclasses 5.53+ for circuits in which the cathode ray passes through a tunable hollow distributed parameter device, and subclasses 39.55+ for distributed parameter resonator type magnetrons having variable tuning means. 315, Electric Lamp and Discharge Devices: Systems,
5.46+, for a cathode-ray tube circuit which has plural hollow indicator or distributed parameter type inductive structure; subclasses 5.53+ for cathode ray tube circuits with tunable distributed parameter type inductive structure, and subclasses 39.55+ for combined load device or load device temperature modifying means and electrical magnetron circuit device structure of the variable tuned distributed parameter resonator type. (See "Tuners Combined With or Incorporated in Other Devices," above.)
318, Electricity: Motive Power Systems,
16, for electrical motor power systems which are controlled from a distance by space transmitted electromagnetic or electrostatic energy and which are closely analogous to some remote controlled tuner circuits; subclass 460 for electrical motor power systems which have automatic and/or time-delay means which are responsive to sound, supersonic vibration or mechanical vibration, and subclass 480 for systems responsive to radiant energy.
318, Electricity: Motive Power Systems,
16, for a motor control system controlled by space transmitted electromagnetic or electrostatic energy, and subclass 510 for electrical motive power systems having an impedance controlled armature or primary circuit which comprises diverse impedances including an inductor and capacitor. (See "Tuners Combined With or Incorporated in Other Devices," above.)
318, Electricity: Motive Power Systems, appropriate subclass for a motor system which may be used to drive and control a tuner. Note especially
445+, for motor control systems which automatically start and/or stop at a particular point such as might be used with a remotely controlled television type tuner. (See "Tuner Components and Subcombinations,")
322, Electricity: Single Generator Systems,
78, for generator control systems which have plural impedances in the excitation circuit, the impedances forming a tuned circuit.
322, Electricity: Single Generator Systems, 78, for generator control systems which have a tuned or resonant circuit in the excitation winding or control circuit. (See "Tuners Combined With or Incorporated in Other Devices," above)
324, Electricity: Measuring and Testing,
76.41+, for measuring, testing or sensing electricity, per se, by frequency comparison, and subclass 76.51 for measuring, testing or sensing electricity, per se, by a tuning step.
324, Electricity: Measuring and Testing,
76.41+, for circuits which measure, test or sense electricity, per se, by frequency comparison. The frequency comparison circuit usually has at least one or more tuned circuits. See also, subclass 76.51 of Class 324 for frequency testing systems in general utilizing tuning. (See "Tuners Combined With or Incorporated in Other Devices,"
above)
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,
3+, for miscellaneous phase comparing circuits and subclasses 40+ for miscellaneous frequency comparing circuits, either of which may utilize a tuned circuit.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,
3+, for miscellaneous phase comparing circuits and subclasses 40+ for miscellaneous frequency comparing circuits, either of which may utilize a tuned circuit. (See Lines With Other Classes, "Tuners Combined With or Incorporated in Other Devices," above.)
329, Demodulators, appropriate subclasses for demodulators with tuned input or indicator.
329, Demodulators, appropriate subclasses for demodulators with tuned input. (See "Tuners Combined With or Incorporated in Other Devices, " above.) 330, Amplifiers,
65, for structure of various amplifier elements such as a tuned circuit; subclasses 144+ for amplifier stages having a variable impedance element which is controlled by a separate control means; subclass 154 for cascaded amplifiers having a resonant circuit used in the interstage coupling network; subclasses 165+ for interstage coupling of the transformer type; subclasses 188+ for transformer coupled input circuits and subclasses 195+ for amplifiers having transformer coupling in the output circuit.
330, Amplifiers,
154, for cascaded amplifier stages having a transformer or resonant circuit in the interstage coup- ling, subclasses 157+ for interstage coupling networks which may include resonant circuits, subclasses 185+ for input coupling networks and subclasses 192+ for output coupling networks which may include resonant circuits. (See "Tuners Combined With or Incorporated in Other Devices," above.)
331, Oscillators,
1+, for oscillators having automatic frequency stabilization means using a phase or frequency sensing means; subclasses 96+ for oscillators with distributed parameter resonators; subclasses 117, 128, and 167+ for inductor-capacitor type oscillators, and subclasses 177+ for oscillators having frequency adjusting means.
331, Oscillators, appropriate subclasses, for oscillator
circuits which contain a frequency or period determining element such as a resonator or tuning means. See
1+, for automatic frequency controlled oscillators, subclasses 167+ for oscillators having an L-C type tuned circuit, and subclasses 177+ for frequency adjusting means combined with the oscillator circuit. (See "Tuners Combined With or Incorporated in Other Devices," above)
332, Modulators,
140, and 142+ for variable reactance tubes in a frequency modulator and subclass 175 for a variable tuned circuit in an amplitude modulator.
332, Modulators, appropriate subclasses for modulators using tuned circuits and particularly 175, for a variable tuned circuit in an amplitude modulator. (See "Tuners Combined With or Incorporated in Other Devices," above.)
333, Wave Transmission Lines and Networks, appropriate subclasses for wave transmission lines and networks which may be resonant at one or more frequencies, especially
167+, for wave filter coupling networks and for tuned resonance type wave filters which may be referred to as a tuner. (Also found in these subclasses are the resistor-capacitor circuits such as bridged-T, double-T or Weir Bridge networks, for example, which are sometimes referred to as tuners) ; subclasses 235+ for variable resonators of the distributed parameter type, and subclasses 245+ for long line elements. (see "Tuners Classified Elsewhere" above)
333, Wave Transmission Lines and Networks, appropriate subclasses, especially
167+, for wave filters in general having fixed center frequencies, particularly indented subclass 175 for resonant type wave filters, and see subclasses 219+ for tuners of the distributed parameter resonator type in which there are no lumped impedance elements present and where only a single resonator is used. (See "Tuners Combined With or Incorporated in Other Devices," above.)
333, Wave Transmission Lines and Networks,
213+, for positive or negative reactance networks of the active element type and subclass 235 for resonators of the distributed parameter type which may be mechanically and/or electrically connected together to form a tuner. (See "Tuner Components and Subcombinations," above.)
335, Electricity: Magnetically Operated Switches, Magnets, and Electromagnets,
209+, for magnets and electromagnets.
336, Inductor Devices, appropriate subclasses for inductors, per se, which may have a fixed or variable inductance value.
336, Inductor Devices, appropriate subclasses for inductor devices of the type which are adapted to be combined with some capacitor means to form a tuned circuit. (See "Tuner Components and Subcombinations, " above.) 338, Electrical Resistors, appropriate subclasses for resistors, per se, which may be closely analogous to certain types of tuners.
338, Electrical Resistors, appropriate subclasses for resistor elements which may be used in combination with an inductor and capacitor means to form a tuned circuit. (See "Tuner Components and Subcombinations, " above.)
340, Communications: Electrical,
825+, for selective remote control system; and subclasses 825.69 and 825.72 for systems having a control signal utilized to control a remotely located system or device.
340, Communications: Electrical,
825.69, and 825.72 for systems having a control signal used for control purposes. (See"Tuners Combined With or Incorporated in Other Devices," above.)
343, Communications: Radio Wave Antennas,
745+, for an antenna having variable reactance for tuning, and subclasses 850+ for antennas with a coupling network or impedance in the lead-in.
343, Communications: Radio Wave Antennas, appropriate subclasses for radio wave energy systems utilizing tuned circuits,
745, for antennae with variable reactance means for tuning the antenna. (See "Tuners Combined With or Incorporated in Other Devices" above.)
346, Recorders,
37, for a recorder device combined with and responsive to the tuning 346, Recorders, subclass 37 for recording means which is responsive to the tuning means of a radio receiver. (See "Tuners Combined With or Incorporated in Other Devices above) 348, Television,
731+, for tuners associated with television receiver
circuitry including search tuners and tuners combined with indicator, subclass 734 for remote control of a tuner in a television receiver, and subclass 735 for automatic frequency control circuits.
361, Electricity: Electrical Systems and Devices,
113, for electrical safety protection systems and devices having a tune circuit; subclass 270 for transformer or inductors combined with a capacitor; and subclasses 271+ for capacitors, per se.
361, Electricity: Electrical Systems and Devices,
113, for electrical equipment having safety or protection equipment which employs a tuned circuit, and subclasses 161 and 147 for frequency responsive circuits for relays and electromagnets in which the frequency responsive circuit usually has one or more tuned circuits. (See "Tuners Combined With or Incorporated in Other Devices," above.)
361, Electricity: Electrical Systems and Devices,
271+, for capacitors, per se, which are used in combination with an inductance means to form a tuner. (See "Tuner Components and Subcombinations," above.)
370, Multiplex Communications, appropriate subclasses, particularly
343+, for combining or distributing information via frequency channels in communication over free space, and subclasses 480+ for combining or distributing information via frequency channels in communication over wire.
370, Multiplex Communications, appropriate subclasses, particularly 343+, for combining or distributing information via frequency channels in communication over free space, and subclasses 480+ for combining or distributing information via frequency channels in communication over wire. (See "Tuners Combined With or Incorporated in Other Devices," above.)
373, Industrial Electric Heating Furnaces,
138+, for electrical induction type furnaces involving a charge supported by an adequate furnace structure and placed in electromagnetic relationship with an inducing winding, the charge forming the secondary of the coil winding. The coil winding may be resonant with a capacitor.
455, Telecommunications,
120+, for radio transmitters with tuners; and subclasses 150.1+ for receivers with tuners.
455, Telecommunications,
100+, for a transmitter having a tuner; and subclasses 150.1+ for a receiver having a tuner. (See "Tuners Combined With or Incorporated in Other Devices," above)
455, Telecommunications,
150.1+, for apparatus such as a housing that may be used with a tuner. (See "Tuner Components and Subcombinations," above)
GLOSSARY:
CAPACITOR That property of a system of conductors and dielectrics used to secure an appreciable capacitance by allowing the storage of electricity when a potential difference exists between the conductors. There must be at least two or more conductors separated by a dielectric.
CAPACITANCE
The property of a capacitor to store and hold an electric charge and which is equivalent to the ratio of the equivalent charge stored in the capacitor to the resultant change of potential.
ELECTROMAGNETIC OPERATOR
A machine or device which is capable of exerting a force upon the control or actuator of an element or circuit to thus move or control the element or circuit, the machine or device being operated by the interaction of the magnetic effect of an electrical current and/or magnetic field. An example, of this type of machine or device is a relay, solenoid or electric motor connected to the shaft of a variable capacitor, the machines or devices responding to a flow of current and/or voltage through them to thus drive or move the shaft of the variable capacitor.
FREQUENCY
The number of complete alternations or cycles made by an alternating signal per unit of time. The frequency unit most used is cycles per second.
FREQUENCY BAND
A plurality of different frequency channels which are grouped together into a particular bunch or group of channels all designated or used for the same purpose. An example of this is the broadcast band which consists of a plurality of frequency channels whose center frequencies are separated by a specified amount, each frequency being used for the same purpose, namely the transmission of speech. A second example
of a band of frequencies is the use of certain channels of frequencies for the transmission of television. Here the common purpose of the plural channels of frequencies making up the band is the transmission of a video signal plus an audio signal.
INDICATOR
An element or device which is particularly adapted to point out or show, usually visually, the position and/or condition to which a given element or elements are adjusted as, for example, a scale and pointer, one of which is held stationary while the other is connected to a rotatable or movable shaft such as the shaft of a variable capacitor. A second example would be the use of a meter to indicate the amount of current and/or voltage flowing in a given circuit. INDUCTANCE
That property of an electrical circuit, or of two or more neighboring circuits, by which a varying current produces or induces an electromotive force in the circuit or neighboring circuits. If an electromotive force is induced in the neighboring circuit or circuits, the term mutual inductance is used.
INDUCTOR
An impedance device comprising a coil means, with or without core means, for introducing inductance into an electric circuit. Both transformers and inductive reactors are included within the meaning of "inductor".
RESONANCE
The point in the adjustment of a tuned circuit to a particular channel or signal frequency at which the inductive reactance equals the capacitive reactance. The resonance frequency may also be described as the point where the oscillation or vibration present in the circuit may be maintained with the least amount of external excitation with the excitation producing a relatively large amplitude of oscillation or vibration.
TUNER
A device for tuning which consists of an inductor and capacitor or an inductor, capacitor and resistor so connected and resistor so connected as to form a resonance circuit, the mean frequency or channel to which the tuner is resonant being variable. The resistance may be in the form of the inherent resistance of the circuit or a lumped resistance element connected in the circuit. For a lumped resistor element connected in a tuned circuit, see Subclass References to the Current Class, above.
TUNING
The step or steps by which a tuner is adjusted in relation to a signal frequency or channel in order to obtain optimum or maximum resonance of the tuner circuit or system at some selected operating point or signal frequency.
VARIABLE INDUCTOR A passive inductor wherein the inductor device includes a movable element which may be adjusted to different positions or adjusted to vary its physical dimensions to change the effective inductance from one value to another. Examples of such movable elements are: a tap changing switch, a distortable coil or core, or movable coupled coils. Inductor devices designed to change inductance (1) as a function of the current and/or voltage flowing through the inductor winding, or (2) in accordance with a magnetic field or bias applied to the core or coil of the device, or (3) as a function of the ambient temperature or some external condition applied to the device, and wherein no physical element of the inductor is moved to effect such change in inductance, are not considered adjustable under the above definition. For such variable inductors, see Subclass References to the Current Class, above for for magnetic field responsive tuners, for condition responsive tuners, and for saturable core type tuners.