US 3531602 A
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.w A8 R6 am N w D9 o 2 R R Em B Mr Ea E PM Sw J wl Ui 0F R H T sept. 29, 1970 RADIO OR THE LIKE WITH CONTROL SHAFT EXTENDING -INVENTOR. E. Brown Jesse v A l'ftorney United States Patent O 3,531,602 RADIO OR THE LIKE WITH CONTROL SHAFT EXTENDING THROUGH SPEAKER DIAPHRAGM Jesse E. Brown, Glencoe, lll., assignor to Zenith Radio Corporation, Chicago, Ill., a corporation of Delaware Filed Mar. 29, 1968, Ser. No. 717,082 Int. Cl. H041' 7/02 U.S. Cl. 179-115 3 Claims ABSTRACT OF THE DISCLOSURE An appliance utilizes a loudspeaker with holes formed in the speaker diaphragm so -as to allow appliance control shafts to extend through the diaphragm. Front panel operation of controls is thus provided in conjunction with a loudspeaker with the same area as the front panel, allowing maximum low frequency audio response for a given appliance cabinet size.
SUMMARY OF THE INVENTION The invention relates in general to electrical appliances producing an acoustic output and more particularly to electromechanical transducers for use therein.
One of the problems involved in the design of yappliances such as radio receivers is the diticulty in obtaining suliiciently broad audio frequency response through the loudspeaker. It is desirable in meeting this problem to use the Ilargest loudspeaker possible for a given cabinet size, thus enhancing the bass response. By mounting this loudspeaker on the cabinet front panel facing the operator, it is also possible to take advantage of the directional properties of high frequency acoustic waves and efficiently utilize the treble output available from the loudspeaker.
It is Ialso desirable to provide the convenience of front panel operation of appliance controls such as volume, tone, and on-otf. Previously, however, the inclusion of this feature either effectively limited the front panel area available for the loudspeaker or required the use f undesira'bly complex mechanic-al couplings extending through the speaker magnet.
Accordingly, it is an object of the invention to provide an appliance With improved audio frequency-response for a given cabinet size plus the convenience of front panel operation of appliance controls.
In accordance with the invention, an appliance such as a radio receiver or the like comprises an electromechanical transducer which includes a diaphragm and is responsive to an applied electrical signal for vibrating the diaphragm to produce a corresponding acoustic output. Means are provided for producing an electrical signal and applying this signal to the electromechanical transducer to produce a predetermined -acoustic output. Also provided is a device on one side of the diaphragm having an associated movable control member and responsive to predetermined actuation thereof for controlling an operating characteristic of the appliance. This movable control member extends through the diaphragm and is adapted for the predetermined actuation from the other side of the diaphragm.
BRIEF DESCRIPTION `OF THE DRAWINGS The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together With further objects Iand advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing, in the several figures of which like reference numerals identify like elements, and in which:
3,531,602 Patented Sept. 29, 1970 FIG. 2 is an exploded perspective view of the receiver of FIG. l.
DESCRIPTION OF THE PREFERRED EMBODIMENT FIG, 1 shows a radio receiver 1 with a cabinet 2, speaker grille 3, and two control knobs 4, 5. The receiver employs an electromechanical transducer such as a loudspeaker v6 with a roamed cellular plastic diaphragm 7 and mounting 4frame 8 of unitary construction as shown in FIG. 2. This loudspeaker may I"be constructed, for example, in the manner described in U.S. Pat. No. 3,351,719.
In accordance with the invention, two round holes 9, 10 are provided in the lower corners of the diaphragm 7. Mounted on the receiver chassis 11 are two control potentiometers 12, 13, the shafts 14, 15 of which extend through the diaphragm holes 9, 10 and corresponding holes 16, 17 provided in the speaker grille 3. Actuation of the controls is accomplished by using two knobs 4, 5, aiixed to the ends of control shafts 14, 15.
With the speaker construction shown, the provision of small holes within the diaphragm produces no substantial deterioration in loudspeaker volume or frequency response; the position of the holes is not critical. However, larger holes with areas of an appreciable fraction of the total diaphragm area placed near the center of the diaphragm may result in some loss of loudspeaker eiciency. Therefore it is preferable that holes of this size be placed as close to the periphery of the diaphragm as possible.
In addition to radio receivers the invention is adaptable to phonographs, units converting FM receivers for stereo reception, magnetic tape players, and other appliances utilizing electromechanical transducers to produce acoustic output. The invention is also applicable with other types of movable control members, as for example axially or pivotally movable switch or control shafts, it being only required to provide holes through the diaphragm of sutiicient size to permit unencumbered motion of the control member throughout its control range.
By extending control shafts through holes in a loudspeaker diaphragm the invention allows the largest possible loudspeaker radiating area for a given cabinet size. This provides maximum low frequency audio response along with the convenience of front panel operation of appliance controls.
While a particular embodiment of the invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, Accordingly, the aim in the appended claims is to cover all such changes and modifications as may fall within the true spirit and scope of the invention.
1. In combination in an appliance:
an electromechanical transducer comprising a diaphragm and responsive to an applied electrical signal for vibrating an active vibratile sound-producing portion of said diaphragm to produce a corresponding acoustic output;
means for producing an electrical signal and applying said signal to said electromechanical transducer to produce a predetermined acoustic output;
and a device on one side of said diaphragm having an associated movable control member and responsive to predetermined actuation thereof for controlling an operating characteristic of said appliance, said movable control member extending through said active vibratile sound-producing portion of said diaphragm and being adapted for said predetermined actuation producing portion of said diaphragm is substantially the from the other""side of said'diaphragm 2. An appliance as in claim 1 wherein said electromechanical transducer is a loudspeaker comprising said diaphragm and further comprising a frame and magnet supporting elements, said diaphragm, said frame, and said magnet supporting elements being constructed of foamed cellular plastic;
said means for producing an electrical signal is a radio receiver chassis; said device is a control potentiometer; and said movable control member is a control potentiometer shaft. An appliance as in claim 1 wherein said appliance is situated within a cabinet and the area of said soundsame as the area of the largest'face of said cabinet.
References Cited UNITED STATES PATENTS .2,056,002 9/1936 De Sakhnoisky 325-360 2,934,639 4/1960 Salisbury 325-352 3,026,958 3/1962 [Haerthe 181-32 3,351,719 11/1967 Schoengold 179-1155 KATHLEEN H. CLAFFY, Primary Examiner T. L. KUNDERT, Assistant Examiner U.S. C1. X.R.