US 3611150 A
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United States Patent Hermann Martin Tilnm Schumannstrasse 34a, Frankfurt/Main; G'u'nter Wolf, Brueckenstrasse 16,
Inventors Steinhelm/Main, both of Germany App]. No. 733,586 Filed May 3 1, 1968 Patented Oct. 5, 1971 Priority June 2, 1967 Germany mo rfiiveiixiaussarasnnc A CONTINUOUS SHAPE WITH CONTROL KNOBS 2 Claims, 5 Drawing Figs.
US. Cl 325/361,
312/7 Int. Cl H04b 1/08 Field of Search 325/352,
 References Cited UNITED STATES PATENTS D.133 ,173 7/1942 Brooks 325/361 X D.196,679 10/1963 Schafier 325/352 UX 2,514,670 7/1950 Rabinowicz 325/352 Primary ExaminerRobert L. Griffin Assistant Examiner-R. S. Bell Attorney-Kurt Kelman ABSTRACT: A radio receiver in which the housing for the electronic circuit elements and the control knobs for variable condensers, switches and the like joiintly form a body symmetrical relative to the axis of the rotation of the control knobs or of each control knob and circular in cross section perpendicular to the axis. The housing jointly with the knob or knobs may thus have the shape of a cylinder, sphere, ellipsoid of revolution and the like.
RADIO RECEIVER HOUSING FORMING A CONTINUOUS SHAPE WITII CONTROL KNOBS BACKGROUND OF THE INVENTION This invention relates to radio receivers, and particularly to housings for radio receivers and associated elements.
The visible parts of a radio receiver usually consist mainly of a housing and of control knobs mounted on the housing and connected by rotatable shafts to circuit elements in the housing, such as variable capacitors, switches, and otentiometers. The knobs often detract from the appearance of the housing, particularly in small transistor radios in which the conventional knobs cannot be reduced in size in the same ratio at which the housing is reduced when transistors replace electron tubes if the adjusted positions of the knobs are to be read from a scale with adequate accuracy.
The object of the invention is an improvement in the shape of housings and control knobs for radio receivers, particularly transistor radios, which permits the positions of the control knobs to be read precisely even on a very small radio without encumbering the housing with conspicuously projecting knobs.
SUMMARY OF THE INVENTION With this object and others in view, as will hereinafter become apparent, the invention provides a housing of the type described with an edge portion of circular cross section per pendicular to the axis of rotation of one of the control shafts. The control knob mounted on the shaft also has an edge portion of circular cross section perpendicular to this axis, and the edge portions of the housing and of the control knob are axially contiguous and of substantially the same diameter.
If the outer, axially extending surfaces of the edge portions are symmetrical relative to the axis, at least the edge portions jointly have the shape of a body of revolution about the axis, and the knob need not be conspicuous, regardless of its actual dimensions. A smooth transition between the knob and the housing proper is beneficial, and the surfaces of the edge portions should be jointly defined, therefore, by a continuous function, such as a straight line or a conic.
Other objects, additional features and many of the attendant advantages of this invention will readily be appreciated as the same becomes better understood by reference the following detailed description of preferred embodiments when considered in connection with the appended drawing.
BRIEF DESCRIPTION OF THE DRAWING In the drawing:
FIG. I shows a spherical transistor radio of the invention in elevation;
FIG. 2 shows a cylindrical radio of the invention in a perspective view; FIG. 3 shows a modified spherical radio in plan view.
FIG. 4 shows a modification of the radio of FIG. 1 in a corresponding view; and
FIG. 5 illustrates the radio of FIG. 1 in partly sectional elevation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring initially to FIG. 1, there is seen a small, self-contained table radio whose tuning knob is mounted on the housing 2 for rotation about a common axis 5 with the knob 3 which operates an on-off switch and the potentiometer of a volume control in the housing 2 in a conventional manner, the electronic circuit elements not being seen.
The knobs l, 3 and the housing 2 jointly form a sphere which is supported on an annular stand 4 fixed to the housing 2. The knobs thus are spherical segments of one base, and the housing 2 is a spherical segment of two bases. The axially contiguous edge portions of the housing and of each knob are of circular cross section perpendicular to the axis 5 and of the same diameter. In every plane through the axis 5, the outer surfaces of the knobs ll, 3 and of the housing 2 are defined by a circle which is a continuous function, and more specifically a conic.
The relative angular position of the knobs 1, 3 and of the housing 2 may be indicated by index marks (not shown) along the edge portions, and the diameter of a circular scale so formed may be chosen by suitably locating the base planes which separate the housing from the knobs. Even if the tuning knob, for example, were enlarged to constitute one-half of the sphere formed by the housing and the: knobs, and the scale were as long as it can be made on a housing of the given shape, the knob would not be conspicuous.
FIG. 5 partly illustrates the internal structure of the radio illustrated in FIG. 1. The knobs l and 3 are hollow spherical segments and of uniformly small wall thickness, except for central reinforcing bosses 8, 9 which eonformingly receive the operating shafts 6, 7 of the aforementioned, nonillustrated capacitor and potentiometer with a snap fit or friction fit, as is conventional.
The housing 2 is open along the flat ibases so that batteries and other elements, not themselves shown, are readily accessible for servicing or replacement when the knobs are pried from their shafts by a knife or similar thin instrument capable of being inserted between the edge portions of the knobs and of the housing.
In the radio receiver illustrated in FIG. 2, the knobs l1, 112 are identical cups of cylindrical shape and are coaxially attached to a tubular housing 13 which is cylindrical and of the same diameter.
The two knobs 14, I5 and the associated housing of the receiver illustrated in FIG. 3 jointly form a sphere substantially as discussed with reference to FIG. 1, but the axes of rotation of the two knobs are at right angles to each other. In the modified spherical radio seen in FIG. 4, the knob 16 is a spherical segment of one base and controls the tuning capacitor. The stand 17 is a cylindrical disc which may be rotated on the housing 18 about a common axis with the knob 116 to control the current supply and the sound volume, as described above.
Obviously, numerous other modifications of the housing and knob arrangement of the invention will readily suggest themselves on the basis of the above teachings. Conical, ellipsoidal or otherwise ovate overall shapes are specifically contemplated.
What is claimed is:
l. In a radio receiver having a housing, a plurality of electronic circuit elements in said housing, a plurality of actuating shafts attached to respective ones of said elements in said housing and projecting outward of said housing for turning the attached elements about the axes of said shafts and a control knob on the outwardly projecting portion of one of said shafts, the improvement in said housing and in said knob which comprises:
a. said housing having an edge portion of circular cross section perpendicular to the axis of said one shaft;
b. said control knob having an edge portion of circular cross section perpendicular to said axis of said one shaft; and
c. said edge portions of said housing and of said control knob having axially contiguous, coaxial, cylindrical, outer surfaces of substantially the same diameter.
2. In a receiver as set forth in claim 1, said housing and said control knob jointly having the shape of a body of revolution about said one axis.