US2081752A - Combined radio receiver and talking machine - Google Patents

Description

ma 25, 1937. A. A. LINSELL 2,081,752

COMBINED RADIO RECEIVER AND TALKING MACHINE Filed Jan. 1'7, 1935 5: 1fiiil INVENTOR Alf/7f 4015777 #51 11 ATTORNEY Patented May 25, 1937 UNITED STATES v 2,081,752 COMBINED RADIO RECEIVER AND TALKING MACHI Alfred Aubyn Linsell, London, England, assignor to Radio Corporation of America, a corporation of Delaware Application January 11, 1935, Serial No. 2,173 In Great Britain February 28, 1934 1 Claim.

This invention relates to combined radio receivers and talking machines, 1. e. to devices of the kind at present in common use and known generally-under the name of radio-gramophone.

The invention has for its object to provide an improved tuning control arrangement for a radiogramophone.

Two important'requirements as regards the tuning controls for radio receivers are (1) that 10 the tuning control shall be of such a nature as to be easily adjusted by a relatively unskilled person by very small amounts at a time, and (2) that the scale normally provided in association with the tuning control shall be of as open a nature 5 as possible.

It is usual practice in radio receivers at the present moment to obtain what may be termed sensitivity of tuning control by providing a gear ratio between the tuning control knob and the 20 tuning device, e. g. a variable condenser or gang of variable condensers controlled thereby and it is also known to obtain an open tuning scale by fitting the said scale round the edge of a loudspeaker incorporated in the radio receiver.

25 As regards sensitivity of tuning control, however, it is very desirable, if really sensitive control by quite unskilled operators shall be possible, that the co ntrol handle shall in effect be a knob of large diameter. In the ordinary radio receiver,

30 it is impracticable to provide a large diameter tuning control knob, e. g. a control knob of, say,

12-inch diameter, but the present invention takes advantage of the necessaryexistence of a turntable in a radio-gramophone to enable the effect of a' very large control knob to be obtained.

According to one feature of this invention, the tuning control handle for tuning the radio receiver portion of a radio-gramophone is consti-' tuted by the turntable of the gramophone portion 40 and (where the tuning device is of such a nature; or the general design of the radiogramophone is of such a nature that it is undesirable or impractical to pen-nit the tuning device to be rotated continuously when the apparatusis being used as 45 a gramophone) means are provided for mechanically connecting said turntable with the tuning device when radio reception is required and for mechanically disconnecting said turntable from said tuning device when radio reception is not 50 required, '1. e. when gramophone reproduction is required. Preferably, the tuning device drives an indicator which moves over a scale positioned outside the turntable edge and wholly or partly encircling it.

65 The above feature of the invention may, ii desired, be modified by providing a combined indicator and control handle which is mechanically independent of the turntable of the gramophone portion and is in permanent mechanical connection with the tuning device, said combined indi- 5 cator and handle co-operating with a scale arranged outside the turntable edge and having a handle portion whereby it may be used as the tuning control, the turntable being used in the ordinary way merely as a turntable.

The invention is illustrated in the accompanying drawing which shows schematically various arrangements in accordance therewith.

Referring to Fig. l which shows an embodiment in which the turntable is used as the tuning handle, the turntable shaft l is provided (under the turntable which is not shown) with a grooved or other friction driving pulley 2 keyed thereto. When the radio-gramophone is switched over for use as a radio receiver, friction drive for 2 tuning control is transmitted from this pulley to the tuning device represented schematically at said friction drive being effected through the medium of a second pulley t which is permanently mechanically connected, e. g. by a wire, belt, or other device 5 to the tuning device shaft. The second pulley has a kidney-shaped portion cut out therefrom and the friction drive is transmitted from the pulley 2 on the turntable shaft t to the larger (to) of the two parallel approximately semi-circular edges which are included in the contour of the said kidney-shaped portion t. The radial distance between these parallel approximately semi-circular edges is larger than the diameter of the pulley 2 on the turntable shaft, and the centre '5 of the pulley il which is also the centre of the said parallel approximately semi-circular edges of the kidney-shaped portion is carried upon a pivoted lever ti pivoted at t and spring biased in one direction by a spring it. The lever i3 is adapted to be moved in the other direction by a cam ll pivoted at it and operated by the radio-gramophone change-over switch handle it. The arrangement is such that when the said change-over switch is in the gramophone position, the pulley 6 is moved to break the driving frictional contact between itself and the wall ta of the kidney-shaped portion 6. The pulley t has a pointer it attached thereto, said pointer being adapted to move over a tuning scale it which is concentric with and wholly, or, as shown, partly encircles the turntable. The switch handle i3 is shown in the radio position and is moved in the direction of the arrow for the "gramophone position. 55

phone and upon the shaft I thereof, a friction gear wheel I which drives through an intermediate friction gear wheel ii, a third friction gear wheel to which is mounted upon the control shaft 8b of a variable condenser, gang of variable condensers, or other tuning device 3. Thus, assuming the three wheels to be in driving contact with one another, the rotation of the turntable will cause rotation oi the condenser or other tuning device shaft. in order that the tuning device shaft shall not be rotated when the turntable is rotated for gramophone reproduction, meanspreferably operated automatically by the normally provided radio gramophone change over switchare provided for disconnecting the drive between the turntable shaft and the tuning device shaft. Such means are not shown in Fig. 2, but may consist, for example, of a magnetic clutch inserted at some convenient point in the drive, e. g. between the wheel 16 and the shaft a, or between the wheel to and the shaft so and this magnetic clutch may be arranged to be energized through switch contacts which are automatically closed when the radio-gramophone change-over switch is thrown into the radio" position. Alternatively, and as shown in Fig. 3, instead of using a magnetic clutch, the intermediate wheel l'l may be movably arranged with relation to the other two wheels l8 and So, this said intermediate wheel being carried upon a lever 80. biased by a spring Ma and pivotally mounted at so, the said lever being arranged to be forced against its bias by a cam Ha actuated mechanically by the handle No of the radiogramophone change-over switch '(or by some mechanism which moves therewith) so that when the said change-over switch is in the radio" position, the three wheels are in driving contact with one another.

A convenient form of tuning indicator for use with a construction as described in connection with Fig. 2 or 3 is illustrated in Fig. 4, which represents the main panel" of a radio-grainephone.

Beneath the turntable la and freely pivoted upon the turntable shaft I as axis, is a pointer Ha whose end projects beyond the edge of the turntable and which is adapted to move over an arcuate scale It marked on' the panel or board It normally provided beneath the turntable and through which the turntable shaft projects, said scale wholly or partly encircling the turntable. The pointer is driven from the tuning device shaft to (not shown in Fig. 4) through a chain or any other suitable mechanical drive (not shown) so that the position of the pointer on the scale/l5 always corresponds to the position of the tuning device shaft. Owing to the size of the scale ll,

it may be made very open. In Fig. 4, is represents the tone arm and "pick up, 20 the ammophone-radio change-over switch and 2 l, 22, other controls not concerned with this invention.

Ina further modification shown in Fig. 5, the turntable la. is not employed as the tuning handie, but there is provided freely pivoted upon the turntable shaft I as axis, a pointer Ila which is arranged generally as just described, and which c'o-operates, as above described, with an arcuate scale E5 of larger diameter than the turntable. This pointer is provided with an upstanding hen-- die 23 near its outer end, the handle being conveniently arranged to be grasped by the fingers. Carried by the pointer at its inner end is a gear, chain, or other wheel 24 which is co-axial with the turntable shaft and with the pointer, is freely rotatable thereon, and is mechanically linked by a belt, chain, or other convenient drive 8a. to the tuning device shaft. With this arrangement, to tune the radio receiver, the handle on the pointer is used to swing the said pointer along the scale, the said pointer being made, of course, strong enough to be rigid when used as a tuning handle.

I claim:

In a radio-phonograph combination, said phonograph being provided with a turn-table, and said radio being provided with an operable tuning device, selective means for mechanically con- 1 necting the turn-table with the tuning device when radio reception is desired, and disconnecting the turn-table and tuning device when it is desired to operate the phonograph only, said turn-table constituting the operating control means for operating the tuning device of the radio receiver when said connection is provided, the connecting means between the tuning device and the turn-table comprising a, friction gear wheel permanently mechanically connected to the turntable, and adapted, when the mechanical connection is made, to engage with a driving memher, said driving member being permanently mechanically connected with the operable tuning device, a cam surface provided upon said driving member, said mechanical connection and disconnection being made when desired, by causing a displacing movement between the gear wheel and said member, in such a manner as to bring the further into engagement, and out of engagement, respectively, with the cam surface, said cam surface. comprising an arcuate surface having as its center, a center about which said member rotates for eifecting tuning control, a lever member

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