Detented UHF television tuner with independent inductive fine tuning
AssigneeSarkes Tarzian, Inc.
InventorAlarico A. Valdettaro
Life of this patent
Estimating the term…
Abstract
A UHF television tuner utilizes a mechanical fine tuning mechanism that alters the operation frequency of the oscillator of the tuner independently of the position of the main tuning shaft. The mechanical fine tuning mechanism utilizes a tuning slug disposed inside a tunable coil of the oscillator, and a rotary to linear motion translating mechanism is disposed within the fine tuning shaft for converting a rotational motion of the fine tuning shaft to a linear motion of the slug inside the coil.
Claims22
A UHF television tuning system comprising:
- a UHF tuner having a housing, a continuously variable main tuning shaft rotation of which is effective to cause said tuner selectively to select signals on all channels in the UHF television band, a channel selector shaft, means interconnecting said channel selector shaft and said main tuning shaft, a fine tuning shaft associated with said channel selector shaft, detent means for said selector shaft for establishing a stop position of said main tuning shaft for each of the television channels in the UHF band, a mechanically variable capacitor mechanically coupled to said main tuning shaft, a variable frequency oscillator electrically coupled to said mechanically variable capacitor and having a frequency of oscillation that is adjustable upon rotation of said main tuning shaft over a range of frequencies predeterminedly related to the range of frequencies of the entire UHF television band for determining the frequency of the signal received by said UHF tuner, said variable frequency oscillator having a mechanically variable inductor electrically connected thereto;
- and
- means mechanically coupling said variable inductor to said fine tuning shaft for controlling the frequency of said oscillator to tune said tuner independently of the operation of said main tuning shaft over a range of frequencies corresponding to substantially less than the frequency range provided by said mechanically variable capacitor for fine tuning said UHF tuner.
In a UHF television tuner having a continuously variable main tuning shaft, a channel selector shaft mechanically coupled to said main tuning shaft, a fine tuning shaft coaxially disposed with said channel selector shaft, means for providing a plurality of detent positions for said channel selector shaft and means electrically coupled to said UHF television tuner for adjusting the tuning thereof independently of said main tuning shaft, the improvement comprising:
- an axially movable shaft disposed within said channel selector shaft, said axially movable shaft having an end mechanically coupled to said tuning adjusting means and an enlarged end having an axially varying diameter;
- a ball member disposed adjacent said axially movable shaft in contact with said enlarged end;
- resilient biasing means disposed within said channel selector shaft for urging said axially movable shaft toward said tuning adjusting means;
- means for retaining said ball member and limiting the circumferential travel of said ball member about said axially movable shaft;
- and
- means coupled to said fine tuning shaft for radially displacing said ball member with respect to said axially movable shaft to thereby alter the point of contact between said enlarged end and said ball member, thereby axially moving said axially movable shaft away from said tuning adjusting means.
Dependencies are inferred from the claim text.