US2987616A - Portable radio - Google Patents

Description

M Cm3 Smm www June 6 1961 H. H. sTEGLlcH 2,987,616

PORTABLE RADIO Filed DBC. 19, 195'? United States Patent C 2,987,616 PORTABLE RADIO Herbert H. Steglich, Wilmette, Ill., assignor to Zenith Radio Corporation, a corporation of Delaware Filed Dec. 19, 1957, Ser. No. 703,877 2 Claims. (Cl. 25il`14) This invention relates in general to portable wave signal receivers and in particular to a telescopic antenna arrangement for use therewith.

Telescopic antennas for use `in portable receivers are well known and, conventionally, are vertically mounted within the receiver cabinet. Telescopic antennas are frequently utilized for reception of communications signals, that is signals outside the standard broadcast band. Since the length of such an antenna is readily adjustable, it can be accurately tuned for a selected frequency.

However, in order to fully exploit the capabilities of a tunable antenna care must be taken to prevent capacity loading of the antenna which would effectively change the electrical length of the antenna and thus detune it. Capacity loading of an antenna is considerably aggravated when a large conductive mass, eg., a metallic chassis or cabinet is disposed adjacent the antenna structure. To overcome this loading effect the operating position of the antenna should be such as to present but an insignificant portion of the antenna surface in juxtaposition with any nearby metallic mass.

A further consideration in regard to portable receivers of the type herein discussed concerns the cabinet itself. Since plastic, wood, or other non-metallic enclosures do no-t produce significant capacity loading the antenna can be disposed within the cabinet provided it is carefully oriented with respect to the metal chassis or other metallic masses within the receiver. A metal cabinet is in many instances preferable for portable, as well as nonportable, receivers since in addition to contributing structural rigidity, substantially' complete shielding of the receiver circuitry from external interference is effected. It is thus apparent, in view of the preceding discussion, that a telescopic antenna conventionally mounted within the receiver would be exceedingly inappropriate for use with metal cabinetry. Furthermore, that portion of an extendable yantenna. which would be enclosed within a metal cabinet would not be available for intercepting radiated signal energy.

A number of schemes for supporting and concealing extendable antenna structures are Well known and provide for operation of the antenna outside of the receiver while providing concealed storage when the receiver is inoperative. Such prior art structures do not admit of simplified construction nor, when extended, do they establish the antenna in the most eiiicient operating position.

.It is therefore an object of this invention to provide a telescopic antenna mounting arrangement for a portable radio receiver, which arrangement substantially precludes antenna loading due to stray capacity effects.

It is also an object of this invention to provide a telescopic antenna structure, for a portable radio, which is fully concealed While inoperative but is readily extendable to an operating position.

It is a further object of this invention to provide a telescopic antenna structure for portable receivers which permits utilization of the entire antenna pick-up element.

A portable radio receiver constructed in accordance with this invention comprises a cabinet and a conductive chassis contained Within the cabinet which includes a radio receiver circuit. A handle has one end pivotally secured atop the cabinet by a hinge to permit displacement of the handle from a rst position in which the handle is substantially parallel Ito the adjacent surface of the cabinet to a second position in which it is angularly disposed With respect to that surface of the cabinet. A latch mechanism is supported by the cabinet for releasably locking the handle in the first position. A telescopic rod antenna, normally supported entirely within the handle when the handle is disposed in the first position, is extensible when the handle is displaced to the second posi-tion to `an operating position in which the antenna is angularly and laterally displaced from the chassis to render the antenna free from capacitive loading by the chassis. Finally, means are provided for electrically connecting the antenna to the radio receiver circuit.

The features of the present invention which are believed to be novel are set forth with panticularity in the appended claims. The organization and manner of oper ation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in the several figures of which like reference numerals identify like elements, and in which:

FIGURE l is a front perspective View of a portable radio receiver incorporating the subject invention;

FIGURE 2 is a rear perspective view, partly in section, of a portable radio receiver constructed in accordance with the invention and shown in an operating position;

FIGURE 3 is a fragmentary View, partly in crosssection taken along line 3-3 of FIGURE l and showing the handle and antenna construction of the receiver; and

FIGURE 4 is a fragmentary cross-sectional View illustrating the operating position of the handle hinge mechanism shown in the upper right hand portion of FIG- URE 3.

The portable radio receiver illustrated in FIGURE 1 is a multi-band receiver of the type designed for operation in the Shortwave communications bands in addition to the standard broadcast band. Receiver 10 comprises a metal cabinet 11 having : metallic end portions 12, 13, a hinged front cover 14 which can be releasably secured by a conventional spring catch 55 and a hinged rear cover 15 (FIGURE 2) likewise having a releasable catch mechanism 56. End section 13 supports a turret type band selector switch 16 While a tuning knob 17, a tone control 60, and a volume control and switch 61 are mounted on the fron-t of cabinet 11. A ferrite-core loop antenna (not shown) for use in broadcast band operation is disposed within `a plastic enclosure 18 which is supported atop cabinet 11. The end portions 12, 13 of cabinet 11 include the respective pedestals 19, 20 which mount a hollowed carrying handle 21.

FIGURE 2 shows handle 21 angularly disposed with respect to receiver 10 and reveals a detachable cover plate 57 secured tohandle 21 by conventional fasteners. A telescopic antenna 22 .having a plastic cap 23 is normally supported entirely within hollowed handle 21, and is shown in FIGURE 2 in a partially extended position. The opened extremity of handle 21 includes a pair of tabs 24 which facilitate positioning handle 21 within pedestal 19 when the antenna is retracted and the handle is restored to the carrying position. The manner in which handle 21 is pivotally hinged upon pedestal 20 and secured within pedestal 19 is best illustrated in FIGURES 3 and 4 and will be more fully described below. Electrical means, more specifically conductor 25, connects antenna 22 to the input section 26 of the radio receiver chassis which includes a radio receiver circuit.

'I'he fragmentary cross-sectional view of handle 21 in FIGURE 3 shows telescopic antenna 22 encased within an antenna base portion 31. Base portion 31 is mounted in a fiberglass cylinder 28 disposed within handle 21. A hinge 29 terminates handle 21 and is fastened thereto. Hinge 29 employs a pin 30 which transfixes cylinder 28 and fastens it to the hinge. Pin 30 is rotatably journalled within pedestal 20. Antenna base portion 31 is axially constrained within cylinder 28 by a screw fastener 32 which also electrically connects one end of conductor 25 to base portion 31 while the posts 33, formed upon the inner surface of hollow handle 21, provide lateral stability for base 31.

The previously mentioned tabs 24 bear upon a shoulder 3`4 of pedestal 19 when handle 21 is in the carrying position as shown. A release latch 35, 35 (the primed reference numeral depicting a displaced position of latch 35) having a pair of apertured bosses 36 (only one shown) is mounted upon a shaft 37 which is rotatably secured within pedestal 19. A return spring 38 is mounted upon shaft 37 between bosses 36 and is constrained between an inner surface 39 of pedestal 19 and the inner surface 40 of latch 35 so as to normally urge release latch 35 against the lip 50 of end section 12. Latch 35 further includes a shelf 58 at its upper extremity having an aperture 59 which engages a locking post 62 secured to handle 21.

FIGURE 4 shows handle 21 in an angularly displaced upright position and clearly illustrates the detent latch mechanism 41, 41' (the primed reference numeral illustrating a displaced position of detent latch 41) which, like release latch 35, maintains a pair of apertured bosses 42 (only one shown) for receiving a mandrel 43 which is rotatably journalled within pedestal 20. A detent spring 44 is mounted upon mandrel 43 between bosses 42 and bears against an inner surface 45 of pedestal 20 and upon a ledge 46 of detent latch 41. The lower extremity of detent latch 41 sustains an offset 47, which bears against the rim portion 48 of end section 13 to restrain latch member 41, and a projection 65 to facilitate manual actuation of latch 41.

Hinge 29, previously described as terminating handle 21, further includes a land 63 which engages the upper extremity of detent latch 41 when the handle 21 is in the carrying position (FIGURE 3) and a footing 64 which bears upon latch 41 in a similar manner when the handle is angularly displaced (FIGURE 4).

Operation of receiver is initiated by first displacing front cover 14 to provide access to controls 17, 60, 61 (FIGURE l). A particular band is then selected by the tuner selector switch 16 which positions the appropriate terminals of the turret tuner (not shown) for cooperative engagement with input section 26 of the receiver chassis. During reception of wave signals in the broadcast band the loop antenna disposed within enclosure 18 is automatically connected to input section 26 and reception is effected in a conventional manner.

Reception of signals in the communications bands is accomplished by first positioning selector switch 16 to the desired band. Positioning the turret tuner for operation in the above-mentioned bands disconnects the loop antenna in enclosure 1S and couples telescoping antenna 22 to input section 26. Antenna 22 is readied for operation by first depressing release latch 35 inwardly. As latch 35 pivots about shaft 37, aperture 59 -in shelf 58 is displaced from locking post 62. With latch 35 thus depressed handle 21 is angularly displaced from its first or carrying position to its second or operating position. As hinge 29 rotates upon pin 30 about pedestal 20 detent latch 41 is driven counter-clockwise about mandrel 43 by footing 64 of the hinge. Simultaneously, detent spring 44 is compressed. As handle 21 assumes an upright position (FIGURE 4) the upper extremity of detent latch 41 is driven beneath footing 64 of hinge 29 through the action of detent spring 44. Handle 21 is thus securely positioned for operation. Telescopic antenna 22 is then withdrawn by clasping cap 23 to initiate extension of antenna 22. The telescoping antenna can be extended to any desired operating length. Wave signals intercepted by antenna 22 are translated to input section 26 via conductor 25.

Handle 21 is re-positioned to its carrying position by rst retracting antenna 22 and then depressing projection 65 on latch 41 inwardly so as to displace latch 41 from beneath footing 64 of hinge 29. Handle 21 is then rotated downwardly while latch 35 is displaced to enable handle 21 to enter pedestal 19. When tabs 24 engage shoulder 34 of pedestal 19 latch 35 is released thereby permitting aperture 59 of shelf 58 to engage locking post 62. With handle 21 thus secured receiver 10 can be safely and conveniently transported.

Accordingly, a portable radio receiver 10 as disclosed comprises a cabinet 11 containing a chassis which includes a radio receiver circuit. A handle 21 which encloses a telescopic rod antenna 22 is mounted upon the cabinet and is displaceable from a first or carrying position to a second or operating position. A conductor 25 is provided for electrically connecting antenna 22 to the radio receiver circuit. The operating position of antenna 22, in which handle 21 is angularly displaced, permits utilization of the entire antenna element. Furthermore, by positioning antenna 22 remote from cabinet 11 and its end sections, undesired antenna loading due to stray capacity effects is substantially precluded. The combination handle-antenna device herein disclosed obviates the limitations of prior art antenna arrangements through a simplified and advantageous antenna mounting arrangement.

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, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

I claim:

1. A portable radio receiver comprising: a cabinet; a conductive chassis contained within said cabinet and including a radio receiver circuit; a handle; a hinge pivotally securing one end of said handle atop said cabinet to permit displacement of said handle from a first position in which said handle is substantially parallel to the nadjacent surface of said cabinet to a second position in which said handle is angularly disposed with respect to said surface of said cabinet; a latch mechanism supported by said cabinet for releasably locking said handle in said first position; a telescopic radio antenna normally supported entirely within said handle when said handle is in `said first position and extensible when said handle is in said second position to an operating position in which said antenna is angularly and laterally displaced from said chassis to render said antenna free from capacitive loading by said chassis; and means for electrically connecting said antenna to said radio receiver circuit.

2. A portable radio receiver comprising: a metal cabinet; a conductive chassis contained within said cabinet and including a radio receiver circuit; a handle; a hinge pivotally securing one end of said handle atop said cabinet to permit displacement of said handle from a first position in which said handle is substantially parallel to the adjacent surface of said cabinet to a second position in which said handle is angularly disposed with respect to said surface of said cabinet and said conductive chassis; a latch mechanism supported by said cabinet for releasably locking said handle in said first position; a telescopic radio antenna normally supported entirely within said handle when said handle is in said first position and extensible when said handle is in said second position to an operating position in which said antenna is angularly and later-ally displaced from said metal cabinet and from said chassis to render said antenna free from capacitive loading by said chassis or said cabinet; and means for electrically connecting said antenna to said radio receiver circuit.

References Cited in the le of this patent UNITED STATES PATENTS

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