US3828720A

US3828720A - Dual purpose dial mechanism

Info

Publication number: US3828720A
Application number: US00348967A
Authority: US
Inventors: R Herst
Original assignee: CAR TAPES Inc
Current assignee: CAR TAPES Inc
Priority date: 1973-04-09
Filing date: 1973-04-09
Publication date: 1974-08-13
Anticipated expiration: 1991-08-13

Abstract

A dial and mask combination enables alternate selection of AM or FM broadcast frequencies. The movement of the mask is directly controlled by an FM-AM selector switch. Selecting the FM portion moves the mask to a first position, displaying a portion of the dial representing FM frequencies. Selecting the AM portion moves the mask to a second position, displaying a portion of the dial representing AM frequencies.

Description

mted States Patent [191 [111 3, Herst Aug. 13, 1974 [54] DUAL PURPOSE DIAL MECHANISM 3,502,049 3/1970 Samet 116/135 D [75] Inventor: Richard J. I-Ierst, Woodland Hills, 3605 681 9/1971 avles 6/115 5 Calif. FOREIGN PATENTS OR APPLICATIONS [73] Assignee: Tapes, Inc Chatsworth, m 291,912 6/1928 Great Britain 40/28 C [22] Filed: 1973 Primary ExaminerLouis J. Capozi [21] Appl. No.: 348,967 Attorney, Agent, or Firm-Marvin H. Kleinberg [52] US. Cl 116/l24.1, 40/28 C, 116/135 [57] ABSTRACT [51] Int. Cl. H03j l/02 A dia! and mask Combination enables alternate selec [58] Fleld 0f Search 116/124.1, 124.2, 124.3, tion of AM or FM broadcast frequencies. The move 1 16/1244 40/28 ment of the mask is directly controlled by an FM-AM 35/ 9 H; 325/455 464; 334/86 selector switch. Selecting the FM portion moves the mask to a first position, displaying a portion of the dial [561 References C'ted representing FM frequencies. Selecting the AM por- UNITED STAT S P S tion moves the mask to a second position, displaying a 1,594,703 8/1926 Ballerini 40/28 C portion of the dial representing AM frequencies. 2,426,079 8/1947 Bliss Mallinger 116/116 7 Claims, 8 Drawing Figures PATENIED ms 131914 Y 3. 828; 720

' sum 3 or 4 Fig. 5.

DUAL PURPOSE DIAL MECHANISM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a dial display suitable for use with receivers capable of receiving either FM stations or AM stations and more particularly to the use of a single numbered dial system capable of being alternately used for either FM or AM stations.

Radio receivers capable of receiving amplitude modulated signals, commonly called AM signals, have a tuning range covering the radio spectrum from approximately 550 kilohertz through 1,600 kilohertz. AM radio dials normally have a first indication of 55 to indicate the low end of the broadcast band of 500 kilohertz and an indication of 160 to indicate the high frequency end of the broadcast band, namely 1,600 kilohertz.

Radio reveivers capable of receiving frequency modulated signals, commonly called FM signals, normally cover a frequency spectrum of 88 megahertz at the low end of the broadcast band and terminate at the high end of the broadcast band with an indication of 108 to indicate 108 megahertz.

2. Description of the Prior Art With the advent of transistors and the miniaturization of electrical components, it has become highly desirable and extremely practical to include an FM receiver and an AM receiver on the same chassis. Selection of either the AM band or the FM band is usually determined by the movement of a single knob located on the face of the radio receiver. Receivers capable of receiving both FM and AM bands have been extremely popular for use in automobiles, especially when combined with a complete audio system capable of mechanically receiving and playing pre-recorded tape cassettes.

At the present time the industry usually bifurcates the space available for displaying both series of numbers associated with the AM and FM bands. Usually both the FM and AM dials are individually illuminated and controlled by moving the AM-FM selector switch.

In another embodiment, the prior art has elected to bifurcate the available space into an FM and AM portion, and by the use of masks operated by the FM-AM selector switch, one-half of the bifurcated dial is rendered opaque upon the movement of the selector switch. The bifurcated dial remains illuminated as an indication to the user which band he has selected.

These prior art systems have achieved a certain measure of commercial success. However, present day consumer advocates have recognized that using only one half of the total available display space for illuminating a dial in today's fast moving automobile represents a potential hazard to both the operator of the vehicle and to other members of the general public on the highway.

The art'has recognized that it is highly desirable in a confined area, as on the dashboard of an automobile, that the largest space available be allowed for the illumination of the radio dial in order to allow the user to quickly and immediately recognize and identify the radio station that he is desirous of sleecting. The present day practice of bifurcating the allowable space into an FM portion and AM portion represents the best that is available to the public today.

Normally FM-AM tuners incorporated into an, automobile tape cartridge player are provided with a small bifurcated dial within a limited space above the tape cartridge mechanism: The movable door covering the cartridge receptacle generally is substantially larger than the normal FM-AM dial.

SUMMARY OF THE INVENTION According to the present invention, the movable door is also utilized as the dial. A movable pointer is driven by the tuning mechanism. A further aspect of the invention is the use of ambiguous transparent indicia on an otherwise opaque dial which, in combination with a substantially transparent mask with selected opaque portions, enables the ambiguity to be resolved alternatively into an AM dial or an FM dial.

In the present invention the increased space now available for the display dial of the FM-AM receiver is utilized to present the bands of numbers used to identify either the FM or AM bands. The available display area of the dial is substantially opaque with transparent indicia. A movable mask adjacent the display area and controlled by the FM-AM selector switch contains discrete opaque portions for obscuring selected portions of the transparent indicia. Movement of the mask to a first position displays a first portion of the indicia representing the AM band. Movement of the mask to a second position displays a second portion of the indicia representing the FM band.

The complete dial member is adapted to pivot about a single axis without interfering with the operation of the pointer or the sliding mask.

According to the present invention, the dial display is pivotably located in a vertical position allowing the user to observe the indicia being displayed. The size of the pivotal dial member is selected to approximate the size of the present day multi-track cassette cartridge which is adapted to be inserted into the opening created by the rotation of the dial member. Inserting the cartridge closes a micro-switch automatically disconnecting the tuner portion of the combination and allows the tape transport mechanism to operate, using the moving tape as the sound source for the audio system. Removing the tape cartridge allows the dial assembly to return to the vertical position without further acts of the user.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the present invention will be made more apparent by referring now to the accompanying drawings wherein:

FIG. 1 illustrates an opaque display area having a plurality of transparent indicia substantially filling the display area;

FIG. 2 illustrates a movable transparent mask located adjacent the transparent indicia illustrated in FIG. 1 and containing discrete opaque portions for obscuring selected portions of the transparent indicia;

FIG. 3 illustrates how the transparent indicia of FIG. I is masked to represent the FM dial by moving the mask of FIG. 2 to a first position;

FIG. 4 illustrates the display indicia of FIG. 1 masked to represent an AM dial by moving the mask of FIG. 2 to a second position;

FIG. 5 illustrates the front view of an FM-AM radio receiver containing a multi-purpose dial constructed according to the principles of the present invention;

FIG. 6 illustrates the displacement of the dial-door by the insertion of a pre-recorded cassette cartridge;

FIG. 7 illustrates construction details of the dial-door member; and

FIG. 8 is an exploded view illustrating how movement of the FM-AM selector switch controls the movement of the mask member of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, there is shown a fixed indicator dial 10 adapted to be positioned in an aperture within a movable door 11 and includes locating

pins

12, 14. The dial 10 is normally opaque except for those areas containing the plurality of ambiguous and unambiguous indicia l6, 18, 20, 2, 24, 26, 28, 30, 32, 34, 36, 38, 40. The ambiguous transparent indicia 16-40 are carefully designed with respect to both the AM band and the FM band so that opaquing selected portions of the transparent indicia will display either a representation of the FM band or a representation of the AM band to the user.

In the preferred embodiment the transparent indicia 16-40 located on the fixed dial 10 provide the basis for displaying both the FM dial numbers of 88, 92, 100, 106, 108 and also the AM dial numbers of 55, 69, 100, 135, 155. The actual selection of numbers to be indicated for either the FM or AM bands is a function of the tracking capability of the receiver and the availability and practicality of modifying the indicia to indicate a plurality of numbers.

For example, the selection of the low and high numbers for both the FM and AM bands is actually determined by custom and usage in that the public has accepted the FM band as starting at 88 megahertz and terminating at 108 megahertz, whereas the AM band is customarily considered to start at 550 kilohertz and may terminate at 1,550 kilohertz. Most AM dials generally utilize only the first two significant digits of the frequency, so that only the digits 55 and 155 need be displayed.

The linearity of the tuning rate for both the FM and the AM band can be altered within certain limits to accommodate the selection of indicias that are capable of being modified according to the principles disclosed in the present invention. For example, the indicias 8" 16 and 8 18 are modified to indicate 55" for the AM dial and are unmodified to indicate 88 for the FM dial.

lndicias 8 20 and 8' 22 are selectively masked to indiate 69 for the AM dial and 92" for the FM dial. lndicias 1 24, 0 26 and 0' 28 are not modified, and hence are used to indicate 100 for both the AM and the FM dial.

lndicias l 30, 8" 32 and 6" 34 are masked to indicate 135 for the AM dial and 106 for the FM dial. lndicias l 36, 8 38 and 8 40 are masked to indicate 155" for the AM dial and 108 for the FM dial. There are, of course, many other combinations of indicias capable of representing a plurality of numbers by appropriate masking, and the selection of the indicia will be a function of the tracking capability of both the FM and the AM tuning mechanism associated with the receiver.

Referring now to FIG. 2, there is shown a transparent movable mask 42 adapted to be located adjacent to the fixed dial l0.

Slots

44, 46, respectively, mount over loeating pins 12, 14. The

slots

44, 46 allow the movable mask 42 to slide horizontally relative to the fixed dial 10. Located on the movable mask 42 are a plurality of

opaque portions

48, 50, 52, 54, 56, 58, 60, 62, 64, 68, 70, 72.

The mask 42 contains a slot 74 which is shaped to receive an arm which is connected to the FM-AM selector switch of the radio which is more fully described in connection with FIGS. 7 and 8. The operating arm snugly fits within the slot 74 for moving the mask 42 in a horizontal direction. Accurate registration between the fixed dial 10 and the mask 42 is achieved by means of the

pins

12, 14 of the dial l0 riding within the

elongated slots

44, 46.

Referring now to FIG. 3, there is shown an assembly comprising the fixed dial 10 and the movable mask 42 positioned to the right of the fixed dial for displaying the numbers associated with the FM band.

A review of the display numbers 88 will show that the

opaque portions

48, 50, 52, 54 on the movable mask 42 are positioned and sized so as not to interfere with the transparent portions of

indicia

16, 18. With respect to FM numbers 92, opaque portion 56 is located in an interfering relationship with respect to transparent indicia 20, which modified an 8" so that a representation of a 9 is observed. With respect to transparent indicia 22 also in the shape of an 8, the opaque portion 58 and the opaque portion 60 are located in an interfering relationship which permits only the representation of a 2" to be observed.

Transparent indicias

24, 26, 28 are not interferred with, an hence the FM numbers will be observed. With respect to

transparent indicias

30, 32, 34, normally representing 186, opaque portion 62 located wholly within the opening of indicia 32 interfers with the horizontal line, thereby converting the 8" 32 to be observed as a 0." Opaque portion 64 is located wholly within the opening of transparent indicia 34, and hence indicia 34 will not be interferred with and will continue to be observed as a 6.

With respect to numbers l08, opaque portion 66 is located within the opening of the transparent indicia 38, which is normally an 8," so as to interfere with the central portion and allow transparent indicia 38 to be observed as a It will be noticed that opaque portion 66 is of a different shape than opaque portion 62, since indicia 32 must represent a 0 for the FM band and a 3" for the AM band, whereas indicia 38 represents a 0 for the FM band and a 5 for the AM band.

Opaque portions

68, 70, 72 are located in a noninterfering relationship with respect to transparent indicia 40, and hence an 8 will be observed.

Referring now to FIG. 4, there is shown the same fixed dial 10 with the movable mask 42 moved in the left position which thereby causes the opaque portion to be placed in an interfering relationship with the plurality of transparent indicias so as to allow the numbers 55," 69, 100," and to now be observed by the viewer.

Referring now to FIG. 5, there is shown a front view of a combination FM-AM automobile radio and cartridge player having a changeable dial constructed to the teachings of the present invention. The dial numbers illustrated are selected to indicate a band of FM stations. FM-AM radio 76 contains a combination onoff volume control 78 on one side and a station selector knob 80 on the other side. Located in the frontmost portion is an FM-AM dial member 82 which contains the fixed dial l0 and the moving mask 42 for controlling the transparent indicia to be viewed by the user.

Selection of either the PM or AM bands is made by means of an FM-AM selector switch 84 which not only selects either the FM OR AM bands, but also moves the movable mask 42, which is more fully described and illustrated in connection with FIGS. 7 and 8. The physical dimensions of the FM-AM dial member 82 is chosen to approximate that of the present day multichannel tape cartridge which is used in conjunction with the FM-AM radio 76.

The complete FM-AM dial member 82 is pivotally mounted for rotation against the urging of a multichannel tape cartridge 86, which, in FIG. 6, is illustrated in the operating position. Removing the cartridge 86 allows the FM-AM dial member 82 to return to the vertical position as shown in connection with FIG. 5.

Referring now to FIG. 7, there is shown a complete FM-AM dial member 82 pivotally mounted on a horizontal bar 88 to allow the dial member to rotate and accept the multi-channel cassette cartridge 86 (of FIG. 6). The FM-AM dial member 82 is comprised of a frame 90 which provides a framed support for holding the fixed dial and the movable mask 42. Located on the front portion of the dial member is a suitable display area 92 for allowing the viewer to observe the transparent indicia.

Located on each side of the frame 90 is a pair of

adjustable set screws

92, 94 which control the horizontal limits of movement of the movable mask 42. The adjustments provided by

set screws

92, 94 provide a means for finalizing the horizontal registration between the opaque portions located on the movable mask 42 and the transparent indicia located upon the fixed dial 10.

Referring now to FIG. 8, there is illustrated an exploded view of the mechanism used to move the movable mask 42 in response to movement of the FM-AM selector 84. Located on the horizontal bar 88 in a pivotally sliding relationship is a bifurcated bracket 96 having an arm 98 that substantially fits in a mating relationship with a slot 74 located in the moving mask 42. The bracket 96 pivots upon the horizontal bar 88 and is free to rotate about the bar while at the same time slide in either direction in a horizontal manner.

An operating bar 100 is located between the bifurcations of the bifurcated bracket 96 and is also pivotally mounted on the horizontal bar 88. A spring 102 is connected at one end to the FM-AM selector switch 84 and at the other end to the bar 100. The spring 102 is free to pivot about a fulcrum 104 whereby pushing the FM-AM selector switch 84 in a first direction will attempt to rotate the spring 102 about the fulcrum 104, thereby causing the bar 100 to move the bifurcated bracket 96 in a first direction. Moving the FM-AM selector switch 84 in the opposite direction will have the reverse effect upon the bifurcated bracket 96, thereby moving the movable mask 42 in the opposite direction.

A movable pointer 106 preferably constructed of a transparent material is pivotally and slidably mounted on the horizontal bar 88. The pointer 106 is free to rotate about the bar 88 in the same fashion that the FM-AM dial member 82 rotates about the horizontal bar.

Horizontal movement of the pointer 106 is achieved by means of a bifurcated block 108 slideably and pivotally mounted on the horizontal bar 88 and adapted to be moved in a horizontal manner by means of suitable cables 110, 112 attached to the tuning knob 80, illustrated in FIGS. 5 and 6. Pointer 106 is located within the opening of the bifurcations of the block 108, thereby insuring that the pointer 106 will faithfully follow the movements of the block 108 in response to the operation of the tuning knob 80, which also controls the tuner mechanism of the radio.

A review of the complete mechanism shows that the FM-AM selector mechanism and the pointer are completely independent of the position of the dial member and are free to rotate as the dial member rotates in response to the insertion of a multi-channel cassette cartridge. Many modifications of the present invention will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

l. A combined FM and AM dial member comprising: i

a given display area having a plurality of transparent indicia substantially filling said display area; and

a movable mask adjacent said display area and having discrete opaque portions for obscuring selected portions of said transparent indicia,

said mask being movable in a first selected position for displaying a first portion of said indicia representing an AM dial and movable in a second selected position for displaying a second portion of said indicia representing an FM dial.

2. A combination according to claim 1 in which said display area is substantially opaque and only said indicia are transparent.

3. A combination according to claim 1 in which said movable mask is substantially transparent and only said discrete portions are opaque.

4. A combination according to claim 1 in which said mask is movable only in a horizontal direction and in which the amount of movement relative to said fixed display area is controllable.

5. A combination according to claim 1 which includes a movable pointer adapted to traverse said fixed display area.

6. A combination according to claim 5 in which said movable pointer is transparent.

7. A combination according to claim 1 in which said indicia for representing the AM dial include the numbers 55, 69, 100, and 155, and said indicia for representing the FM dial include the

numbers

88, 92, I00, 106 and 188.

Claims

1. A combined FM and AM dial member comprising: a given display area having a plurality of transparent indicia substantially filling said display area; and a movable mask adjacent said display area and having discrete opaque portions for obscuring selected portions of said transparent indicia, said mask being movable in a first selected position for displaying a first portion of said indicia representing an AM dial and movable in a second selected position for displaying a second portion of said indicia representing an FM dial.

7. A combination according to claim 1 in which said indicia for representing the AM dial include the numbers 55, 69, 100, 135 and 155, and said indicia for representing the FM dial include the numbers 88, 92, 100, 106 and 188.