Pushbutton tuner

A pushbutton tuner suitable for its thinner formation wherein a memory slide member is provided on a base plate of a tuner housing which is shiftable in a direction perpendicular to the sliding direction of a button slide, a gear mechanism is disposed for conjoint rotation with the associated memory slide member, said gear mechanism being connected to the base plate and a subframe attached to said base plate, and a worm wheel for transmitting the rotation to said gear mechanism through frictional members is so supported on said subframe that it may move in the direction of supporting said gear mechanism.

BACKGROUND OF THE INVENTION 
This invention relates to a pushbutton tuner suitable for thinner formation 
thereof, and more particularly to a pushbutton tuner which is capable of 
rendering the pushbutton tuner thinner and compact especially at its core 
operating mechanism portion and properly performing a clutch releasing 
operation without causing possible divergence or slippage in such an 
operation. 
To make the pushbutton tuner thinner is advantageous not only for saving of 
the materials employed but also for use of the pushbutton tuner in 
combination with other mechanisms, especially for use as a car radio. 
Accordingly, there have been proposed various structures to reduce the 
thickness of the pushbutton tuner. Some of them have succeeded in 
rendering a pushbutton mechanism portion thinner but they still employs, 
for a core operating mechanism, which is also requisite for the pushbutton 
tuner of this type, a bulky rockable crank structure or other bulky 
structure associated with a crank gear which prevented obtainment of a 
maximum desired reduction in the thickness or size of the pushbutton tuner 
as a whole. The conventional pushbutton tuners have another problem. In 
the pushbutton tuner, the tuning operation is carried out through either a 
so-called one-touch tuning operation by pushbutton means or a fine tuning 
operation by a manual dial selector means and a clutch mechanism is 
provided to switch operation from one to the other of such means. The 
designs of the clutch operating mechanism for these conventional 
pushbutton tuners have been such as to frequently cause defective clutch 
operation after long continuous use thereof. 
It is therefore an object of the present invention to provide an original 
and novel thinner pushbutton tuner which is free from the disadvantages of 
conventional pushbutton tuners as mentioned above. 
SUMMARY OF THE INVENTION 
In order to attain the object of the present invention as mentioned above, 
the pushbutton tuner of the present invention is so constructed that a 
gear mechanism is supported on a base plate, which mechanism is adapted to 
be rotated upon lateral shifting of a memory slide member. A subframe is 
provided on the top face of said gear mechanism, and a worm wheel for 
transmitting the rotation to the gear mechanism through friction members 
is slidably supported on the subframe so as to slide in a direction of 
supporting of said gear mechanism in a manner to be more specifically 
described.

PREFERRED EMBODIMENTS OF THE INVENTION 
Referring now to the drawings, especially FIGS. 1 to 3, there is 
illustrated one preferred embodiment of the present invention. The 
pushbutton tuner of this embodiment has a base plate 1 and a top plate 2. 
On said base plate 1 are mounted a plurality of pairs of dogleg link 
members 4--4 acting as actuating members for station selecting. These 
dogleg link members 4--4 are so disposed that each two adjacent ones are 
symmetrically related, with respective obtuse bends thereof facing each 
other as depicted in FIG. 1. Each such pair of link members 4 are 
pivotably connected at their base ends to the base plate 1 at their 
forward end portion by a common pin 13. Each link member 4 has an 
elongated guide slot 41 at its tip end portion. The guide slots 41 of the 
respective confronting pairs of link members 4--4 are cross-linked and 
laid on each other as best shown in FIG. 2. In each such crossing portions 
of these slots is inserted an engaging member 50 protruded from a bottom 
face of a memory slide member 5 which is disposed over the link members 
4--4. Projections at the forward end of the base plate 1 are bent 
uprightly to form pairs of guide shoulders or seats in the upper side 
margins of spaced recesses 10' formed between said beat-up spaced 
projections. These shoulders or seats receive the edges of button slides 
3. Each recess 10--10 slidably receives and slidably a diecast sliding 
member 33 projecting upwardly from the associated button slide 3 as shown 
in FIGS. 1 and 3. The rear end of the base plate 1 is also bent to form an 
upright guide recesses for receiving the rear ends of the button slides 3. 
On the other hand, the top plate 2 has a pair of guide slots 21-22, 
associated with each button slide 3 as shown in FIGS. 1 and 3, each of 
which slot extends in the longitudinal direction of the associated button 
slide 3. As best shown with reference to the rightmost button slide 3 of 
FIG. 3, guide protuberances 31 and 32 formed on each button slide 3 are 
registered in the associated pair of guide slots 21-22. The top plate 2 
further has apertures 23 located between the respective slots 22. At the 
front of each aperture 23 is a depending tab 24. A spring 25 is mounted 
between each bent tab 24 and a hook portion 34 formed at a rear end of one 
side of the respective button slide 3 for restoration of the associated 
button slide 3 to its original position. The top plate 2 is further bent 
at its forward end to form guides 26 for the button slides 3 and at its 
four corners to form lugs 27 and 28 which are superposed onto upright 
portions of the base plate 1 (not shown) at its four corners and fixed 
thereto by suitable screws passing through openings 29 in the lugs 27 and 
28 and threaded into threaded openings 10b in the base flats 1. The so 
disposed button slides 3, when pressed rearwardly or inwardly, will 
actuate the link members 4 to slidably shift the memory slide member 5 in 
a direction perpendicular to the pressing direction of the button slides 
3. To this end, each of the button slides 3 is provided with a regulating 
member 30. As shown in FIG. 3, the rear end of the regulating member 30 is 
pivotably connected at 35 and the front end thereof has a pin 300 whose 
upper end 301 of reduced diameter is so disposed as to engage with an 
arc-like slot 36 and whose lower end 302 of larger diameter is so disposed 
as to engage with an inner edge 4a of an associated link member 4 
assembled as mentioned above. Thus, it will be seen that when the button 
slide 3 is pressed inwardly keeping the regulating member 30 at a given 
angle preset with reference to the button slide 3, the memory slide member 
5 is shifted by the link member 4. 
In the thus constructed pushbutton tuner, a shaft 49 is provided at one 
side of the base plate 1 as shown in FIG. 2. A sleeve 45 coaxial with 
gears 42 and 43 and a friction plate 44 is fitted around said shaft 49. 
Said sleeve 45 is inserted in a worm gear member 47 through another 
friction plate 46. A sleeve portion 48 of said worm gear 47 is fitted in 
an opening 80 of a movable plate 8 and said friction plate 46 and said 
worm gear 47 are fitted in an opening 70 of the subframe 7 placed on the 
friction plate 44. Said subframe 7 has at one side end portion thereof 
guide pins 71 and 71a which are inserted in apertures 81 and 81a of the 
movable plate 8, respectively, to perform a guiding function. A spring 88 
is mounted between the top end of the guide pin 71 and the top face of the 
movable plate 8 and a stop ring 89 is mounted on said guide pin 71 to 
cause the movable plate 8 to pressingly abut against the subframe 7. The 
movable plate 8 has one side bent downwardly to form a bearing portion 82 
for a worm gear 84. A spring 83 is further provided between one shaft 
portion 85 of the worm gear 84 and a hook portion 86 formed on the movable 
plate 8 to mesh the worm gear 84 with the worm wheel 47 when said movable 
plate 8 is assembled as mentioned above. Another shaft portion 85 of the 
worm 84 is connected through a universal joint mechanism 101 to a tuning 
operation shaft 100 as seen from FIGS. 1 and 2. More particularly, the 
tuning operation shaft 100, along with a gear 103, is rotatably supported 
by a bearing bracket 102 provided on the subframe 7, and connected to a 
coupler 105 through an intermediate member 104 which has protuberances 
104a and 104b extending in directions perpendicular to each other and 
matable with a groove 103a on the rear face of the gear 103 and a groove 
105a of the coupler 105 connected to said shaft portion 85, respectively. 
Thus, the members 103, 104 and 105 constitute said universal joint 
mechanism. In this connection, it is to be noted that the subframe 7 has 
slots 79 at its peripheral portion which are registered with threaded 
members 1d of the base plate 1 by some suitable screw respectively for 
fixation of the subframe 7. The threaded members 1d positioned at forward 
portion of the base plate 1 are also used for fixing of the bracket 102. 
FIG. 4 shows one exemplary preferred form of the button slide 3 employable 
in the pushbutton tuner according to the present invention. In FIG. 4, a 
longitudinal guide slot 37 is formed in the button slide 3. The guide slot 
37 has communicating recess portions 38 on the both sides of the slot 37 
at its intermediate portion thereof. The sliding member 33 is attached to 
the so formed button slide 3. The sliding member 33 has a guide portion 
331 of reduced width formed integrally therewith for registration with the 
slot 37. Said guide portion 331 is in turn formed by diecasting the same 
integrally with engaging projections 332 adapted to be inserted in said 
engaging recess portions 38 and adapted to be brought into contact with 
the top face of the button slide 3 during the sliding operation of the 
same and to abut against the sides of the guide slot 37. The sliding 
member 33 has, at its bottom side portion, an operating portion which 
cooperates with a roller 15 of a kick plate 14 provided at a forward end 
of the base plate 1, as shown in FIGS. 1 and 2, to operate a clutch 
mechanism. The sliding member 33 further has a cam face 333 as shown in 
FIG. 4 for actuation of a free end of a lever member 303 which is loosely 
connected at its tip end to the button slide 3 by a pin 304. The lever 
member 303 is connected, along with a resilient member 305 for prevention 
of quick actuation, to the button slide 3 by the pin 304 and is so 
disposed that its tip end, functioning as a suppression portion 306, may 
front on the forward end of the frequency regulating member 30. As 
mentioned above, said frequency regulating member 30 is pivotably 
connected at its base end to the button slide 3 by a pin 35 and has at its 
forward end the pin 300 whose portion 301 of reduced diameter engages with 
the arc-like slot 36 centered on the axis of pin 35 and whose portion 302 
of increased diameter engages with the inner edge 4a of the link member 4 
disposed as previously stated to actuate the memory slide member 5. In 
this connection, it should be noted that said suppression portion 306 acts 
for restriction at a position further forward than the preset position of 
the pin 300. This restriction action can be attained when the inclined cam 
face 333 of the sliding member 33 which slides according to the pressing 
of a pushbutton 39 and the button slide 3 pushes the base end of the lever 
303 away from the face of the button slide 3 in accordance generally to 
the holding and restriction action of a conventional frequency regulating 
member in a button slide mechanism of this type. 
With the so formed button slide structure according to the present 
invention, the guide portion of the sliding member is assembled in such a 
relation that it is received in the guide slot of the button slide so tht 
it is apparent that such a button slide structure may be formed relatively 
thin. Further, not only the sliding member kept in the relation as 
mentioned above may be slidably guided through the engagement between the 
guide portion and the guide slot, but also the projection provided on the 
guide portion is guided by the opposite face of the button slide, ensuring 
safe sliding of the sliding member. The projection 332, inter alia, is 
constantly in good engaged state since the lever 303 presses the sliding 
member 33 against the button slide 3 when the frequency regulating member 
30 is held and restricted in a locked state and the projection 332 engages 
with the peripheral portion of the slot even when the regulating member 30 
is out of its locking position, though said engaging projection 332 is 
mounted onto the button slide 3 through the recessed portion 38. 
The friction plates 44 and 46 constitute a clutch mechanism. As mentioned 
above, the movable plate 8 which is mounted through the spring 88 on the 
guide pin 71 by the stop ring 89 is adapted to be lifted suitably, which 
will cause the release of the frictional connection between the friction 
plates 44 and 46. In this invention, to actuate the so constructed clutch 
mechanism, a cylindrical threaded member 180 is provided on a side portion 
of the bottom of the movable plate 80. A spherical member 181 is fitted in 
said threaded member 180 at its lower portion, and an adjusting screw 182 
is put in said threaded member 180 so that the lower end thereof contacts 
said spherical member 181. Further, the kick plate 14 is provided at the 
forward end of the base plate 1 to be shifted by the bottom slide 3 
pressed inwardly as mentioned before, in a direction perpendicular to the 
sliding direction of said button slide 3. The kick plate 14 has at one end 
an upright portion 17 which fronts on a receiving end 18a of a clutch 
operating member 18 disposed on the base plate 1 and pivotably connected 
intermediate its ends to the base plate 1. On another end of said clutch 
operating member 18, a circular engaging portion 18b is formed for 
abutment against said spherical member 181. 
Thus, it will be seen that in the clutch releasing operation by the clutch 
operating member 18, the spherical member 181 is pushed upwardly against 
the action of the spring 88 to disengage said spherical member 181 from 
said circular engaging portion 18b. Then, the friction plate 46 is spaced 
from the friction plate 44 by a distance corresponding to the raised 
amount of the spherical member 181. As may be seen, this disengagement 
operation is carried out readily and easily due to the rolling action of 
the spherical member 181. Further, the structure for this operation may be 
formed compactly and suitably and installed in a limited space. Still 
further, the clutch operation may be suitably and readily adjusted in the 
assembled state by operating the adjusting screw 182, requiring no 
accurate adjustment at the time of assembling and allowing easy and rapid 
coping with possible wear or deformation in operation. 
In the present invention, the core movement operating mechanism is 
constructed as follows. In the pushbutton tuner so constructed as 
mentioned above, the memory slide member 5 has elongated slots 51 and 52 
at its side end positions which are adapted to be engaged with a guide pin 
56 formed on the base plate 1 and the threaded member 180, respectively. 
The memory slide member is shifted in the lateral direction by inward 
movement of a button slide 3 and is guided for this movement by said guide 
pin 56 and said threaded member 180. The memory slide member 5 further has 
a rack 53 at its one end which is meshable with the gear 42 of relatively 
small diameter. This meshing is positively maintained by a spring (not 
shown) which is provided between a hook portion 54 formed on said memory 
slide member 5 at its portion near one end thereof and the subframe 7. The 
gear 43 of relatively large diameter is meshed with a rack 62 formed on an 
extended portion 61 of a movable plate 6 which is slidably mounted on the 
base plate 1. As shown in FIG. 2, an attachment member 60 is mounted on 
said movable plate 6, allowing some relative sliding therebetween by means 
of a spring 64. The rack 62 of said attachment member 60 meshes with the 
gear 43. The movable plate 6 has on one side an upright portion 65 which 
in turn has an engaging slot 66 extending vertically. With this slot 66 is 
engaged a pin 94 of a core mounting member 90 which supports cores 91 
which are adapted to enter and leave coil assemblies 9 as shown in FIG. 1. 
Said coil assemblies 9 are comprised of a plurality of coils (for example 
six coils) integrally mounted on a holding frame 95. Said holding frame 95 
has three guide rods 92 extending in parallel with one another from said 
frame 95. The core mounting member 90 is slidably mounted on said guide 
rods 92 and has at one side a bent portion 90a extending in an axial 
direction of the coil assemblies 9. Said bent portion 90a in turn has a 
hanging portion 93 with pin 94 formed thereon which engages with said slot 
66 of the upright portion 65 of movable plate 6. 
In the construction as mentioned hereinbefore, the gears 42 and 43 are 
rotated by means of the rack 53 formed on the memory slide member 5 which 
is shifted in a direction perpendicular to the sliding direction of the 
button slide 3. Due to the difference in diameter between the gears 42 and 
43, the momentum of the memory slide 5 is suitably amplified to actuate 
the movable plate 6 in mesh with the gear 43. In this connection, it is to 
be noted that since the pin 94 of the core mounting member 90 mounting the 
cores 91 engages the slot 66 of said movable plate 6, the operation of the 
memory slide member 5 will cause said core mounting member 90 to be 
shifted, allowing the cores 91 to enter or leave the coil assemblies 9. It 
is further to be noted that since such a conjoint actuation as mentioned 
above is effected using circular gear members, the mounting directions of 
said core mounting member 90 and the holding frame 95 for the coil 
assembly 9 may be suitably selected, i.e., they may be so designed to be 
disposed in a direction perpendicular to the memory slide member 5 as 
shown in the drawings, in the direction parallel to said memory slide 
member 5 or at a position with some angle to said memory slide member 5. 
Thus, the design of the pushbutton tuner may be at discretion according to 
necessity, ensuring smooth and accurate core sliding operation. 
According to the present invention, a worm gear mechanism is employed as a 
gear mechanism for conjoint movement with the memory slide which is 
actuated in association with the pushbutton operation. Consequently, the 
movement of the cores with reference to the associated coils is attained 
by a compact operating mechanism arrangement without using a conventional 
bulky rockable crank mechanism or crank gear mechanism. Thus, this 
invention has a remarkable advantage in that it can provide a thinner 
pushbutton tuner adapted for such a thinner pushbutton gear mechanism. 
Furthermore, said worm mechanism functions not only as a drive operation 
mechanism but also as a stopper mechanism for the associated members in 
the clutch operation, so that the worm mechanism in question can still 
keep its engaging relation even when the engagement of the transmission 
system is released upon the clutch operation. This increases the rigidity 
and stability of the operating mechanism and this assures a proper and 
accurate operative relation for continuous use. 
Further according to the present invention, instead of such a configuration 
that all members are disposed on the base plate as in conventional 
pushbutton tuners, an upper plate is also used for turners of the 
components. More particularly, the button slide is disposed on the upper 
plate so as to face downwardly and the frequency regulating members are in 
turn disposed on said button slide so as to be operatively connected to 
the operating members on the base below plate. This allows separate 
assemblies on the base plate and the upper or top plate in the fabrication 
of the tuner, enabling the assembly of the pushbutton tuner to be more 
easily and quickly carried out. Further, this configuration allows not 
only the button slides but also the parts associated therewith to be 
arranged in a plane while disposing the button slides on the top plate and 
the associated parts at the lower faces of the respective button slides 
for operative engagement with the operating members on the bottom face, so 
that the resulting pushbutton tuner may be formed sufficiently thin, e.g., 
as thin as 10 mm or less, even if the pushbuttons are located at a height 
suitably spaced from the base plate for desirable pushbutton operation. 
Thus, the present invention can provide a thinner pushbutton tuner with 
the other advantages referred to. What is claimed is: