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Publication numberUS3628499 A
Publication typeGrant
Publication dateDec 21, 1971
Filing dateJan 29, 1970
Priority dateJan 29, 1970
Publication numberUS 3628499 A, US 3628499A, US-A-3628499, US3628499 A, US3628499A
InventorsBenford Konrad H
Original AssigneeBowles Benford
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Acoustical signal generator
US 3628499 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] lnventor Konrad H. Benlord 593,165 1 1/1897 Sanders 84/98 X San Francisco, Calif. 3,057,974 10/1962 Cohen 200/46 [21] Appl. No. 6,805 3,094,098 6/1963 Weiner 116/137 1 Filed Jan. 29, 1970 3,094,682 6 1963 Brosh et al.... 340 22 [45] Patented Dec. 21, 1971 3,129,294 4/1964 Henatsch 340/365 X [73] Asslgnee Bowles-Benford 3,215,903 1 1/1965 Barnet 317/134 Continuation-impart of application Ser. N 3,278,714 10/ 1 966 Bernutz 200/ 1 66 PC s- 1965, now PatentNo. 3,433,916 3/1969 Chirota et a1. 200/166 PC 3,500,32 dated 10,1970-Thls 3,500,326 3/1970 Benford 340/147 application Jan. 29, 1970, Ser. No. 6,805 Przmary Exammer-Lou1s .1. Capozl Attorney-Warren, Rubin, Brucker & Chickering [54] ACOUSTICAL SIGNAL GENERATOR 7 Cl 4 D F aims rawmg ABSTRACT: An acoustical signal generator for establishing a U.S. A, serial pulse ignal of reference puI c at a given audiofrequen. 84/98, 116/169, 179/87, 200/166, 317/134, cy and code pulses at a different audiofrequency wherein the 340/l47, 340/1 4 presence or absence of a code pulse between adjacent ll}!- Cl reference pulses e tabli hes a articular code pattern which [50] Field of Search 1 16/18, 67, can be used f id ifi ati d/ commL Th generator i 1 137 A, 169; 179/90 CS; 84/98; ZOO/166 PC; mechanically operated requiring no electrical power and con- 340/311, 1 1721365; 317/134 structed for inexpensive mass production and ofa size suitable References Cited fgrlelgemg convemently earned by person at pract1cally all UNITED STATES PATENTS 577,835 3/1897 Brachhausen 84/98 33 L 3/ 42 I I I 1 P 62 z I 1 l 1 1 Z 11' 1/ T 1 I l l l 1 1 1 ,A-- 1 L ----52 I 8 J 1 l ,-'641 37 as 63 A? L L PATENTEDUECZI m1 3,628,499

' SHEET 1 OF 2 Fig.

INVENTOR.

Konrad H. Benford BY War um, M, W i Attorneys ACOUSTICAL SIGNAL GENERATOR RELATED APPLICATIONS This is a continuation-in-part application of the patent application bearing Ser. No. 480,449, filed Aug. 17, 1965 now US. Pat. No. 3,500,326 for Mechanically Programmed Encoder System.

BACKGROUND OF THE INVENTION The present invention relates to acoustical signal generators and more particularly to an acoustical signal generator capable of functioning as the transmission portion of the mechanically programmed encoder system described in detail in applicants copending patent application identified immediately above. In the aforementioned patent application, there is described a mechanically programmed encoder system for selective control and/or identification wherein a transmitting portion of the system operates when activated to transmit a signal, which is the analogue of a' code represented mechanically on a programmer, to a received portion of the system which is operatively associated with a device to be controlled and which responds to receipt of a code to operate such device if and only if the code which is received matches the code mechanically represented on a programmer operatively associated with the received portion of the system. The

present invention is directed to a particular embodiment of the transmitting portion of the system defined above and as such includes a transducer programmer on which a particular and unique code is mechanically represented and a program transducer designed to receive the transducer programmer and respond to receipt thereof by generating a signal which can be conveniently transmitted to the received portion of the system and which includes the information mechanically stored on the programmer. In the present invention the transmission is accomplished acoustically whereby the program transducer generates a serial pulse train formed by short bursts of vibrations at an audiofrequency (hereinafter referred to as pulses) with each such serial pulse train including reference pulses at a particular audiofrequency and code pulses at a different audio frequency wherein the particular pattern of code pulses is discemable by detecting the presence or absence of a code pulse between successive reference pulses.

Audiofrequency tone generators for acoustically coupling into systems are known in the arts because of the need to conveniently couple into systems linked by telephone lines where access to the lines electronically is inconvenient. At the present time,automatic message recording systems made use of audiofrequency signal generators to enable retrieval of collected and recorded messages by an authorized person communicating with the message recording device by a telephone link. In such systems the subscriber or authorized person establishes a telephone communication with the system and then generates an audiofrequency signal into the mouthpiece of the telephone which serves to identify the caller to the system and causes the system to report the collected messages to the caller. The audiofrequency tone generator thus operates as an identification and control signal.

The present invention is distinguishable from the now known audiofrequency generators in a fundamental manner which gives rise to several important advantages. The audiofrequency tone generators now known in the art and actively used in the manner described above operate by generating simultaneously a plurality of tones selected from a greater number of available tones. The received portion of the system is electronically equipped to respond only to the correct combination of tones and will not respond to either fewer tones, different tones or a greater number of tones. The inherent difficulty in this approach resides in the necessity of generating a multiplicity of different tones and maintaining a discemable delineation between tones of adjacent frequencies while establishing as many different tones as possible within a given allowable bandwidth (the bandwidth being established either by authority or the limitations of the audio communication link).

Since the audio frequency signal generator is being used as an identification device, it is important to establish as many different codes as possible so as to increase the security provided by the system. Because of the limitations stated above and because of the need for such generators to be small enough to be conveniently carried by a user, a relatively small number of different tones are capable of being generated by such devices and as such the security provided is not considered to be very great. In addition and possibly more importantly, a device capable of generating a plurality of different tones, each of sufficient clarity to be clearly distinguishable from the other tones, is necessarily expensive and rather bulky. Accordingly, such devices are not suitable for universal application.

The present invention takes a fundamentally different approach from that described above in that instead of establishing a signal by the simultaneous generation of a plurality of tones it establishes a serial pulse signal requiring only two tones (audiofrequencies) and, on a very practical level, is capable of establishing one billion unique codes, any one of which can be generated and transmitted with the same ease for all practical purposes as the parallel codes of prior art devices but with a much greater assurance of accuracy since only two different frequencies are involved enabling a relatively wide separation between the two.

The serial pulse signal which is generated by the present invention not only minimizes the bandwidth required but also eliminates the necessity for generating the signal according to some predetermined timing schedule. In other words the signal generator of the present invention operates independently of a specified time sequence thus enabling a code to be generated manually. By eliminating the need for an accurate time sequence of code pulse generation the present invention is capable of being manufactured at an extremely low cost since one of the most expensive components of known devices is totally eliminated.

In addition, the present invention has the inherent capability of being self-programmed which is not within the practical capability of prior art devices. Because the present invention only requires the capability of generating two different audiofrequency signals, the physical dimensions of the device are considerably smaller than the acoustical audiofrequency generators now known in the art and it is also capable of being manufactured at considerably less cost so as to be much preferred as a universal identification device.

SUMMARY OF THE INVENTION The present invention provides a device for generating a serial pulse signal comprised ofreference pulses and code pulses wherein reference pulses are all at a selected audiofrequency while code pulses are at a different audiofrequency and a particular pattern of code pulses is determined by the presence or absence of code pulses between successive reference pulses. A flat rigid card, much like credit cards now popularly used, has established thereon a plurality of code element locations with code elements at selected ones of such locations and reference element locations with reference elements at each such location. The card serves as a programmer for a transducer which operates to transduce the pattern of reference elements and code elements mechanically established on the card into a serial pulse train for acoustical coupling into a device such as a telephone. The transducer is formed by a relatively fiat case having a slot and tracks for receiving and guiding the card (programmer) and houses a pair of gears disposed to engage the reference elements and code elements and be selectively driven thereby. Fixed within the case are two audiofrequency tone generators in the form of tone arms each free to vibrate when actuated and selected so as to vibrate at different audiofrequencies. The gears and tone arms are mechanically coupled through actuators which respond to rotation of the gear by setting a tone arm to vibrating. Thus when the card is inserted into the case and a code element, for instance, causes its associated gear to rotate the actuator operates to set the tone arm corresponding to code pulses to vibrating so as to produce a burst of audiofrequency vibrations representative of a code element. The physical location within the casing of the tone arm and the relative physical location of the code and reference element locations on the programmer are such that the particular pattern of code elements on the programmer (the pattern being with reference to the particular code element locations at which code elements are actually presentfor 30 code element locations there are approximately one billion different possible combinations or patterns) is established in the audiofrequency pulse signal by the presence or absence of a code pulse between successive reference pulses.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the signal generator of the present invention with certain portions broken away and certain portions shown in phantom;

FIG. 2 is an exploded view of one embodiment of the present invention with certain portions shown in phantom;

FIG. 3 is an isometric illustration with certain portions shown in phantom of an alternative embodiment of the invention;

FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2 the present invention comprises a programmer in the form of a card 11 and a transducer in the form of an audio signal generator 12. Program card 11 can advantageously be formed from a tough plastic material such as is presently used by companies issuing credit cards and has information stored thereon in the form of spaced teeth along opposing longitudinal edges. Teeth 13 formed along one edge of card 11 establish reference elements on the card and are present at generally regularly spaced intervals along the edge of the card. Each of the locations at which a particular reference element exists is a reference element location 14 and each reference element location has a reference element formed thereat.

Along the opposing edge of card 11 are a plurality of regularly spaced code element locations 16 generally equal in number to the reference element locations and with code elements 17 at selected locations 16. Unlike the reference element locations there are not code elements at each such location. The particular code element location at which a code element 17 exists is the variable which distinguishes one card 11 from another and it is the pattern of code elements with respect to the code element locations which establishes the code information which is mechanically carried by the card and which the transducer 12 transmits in the form of an audio pulse signal as will be more fully described herein below. While the card 11 may contain other information which may be printed, embossed or magnetically embedded into the card, for the purposes of the present invention the elements 13 and 17 provide all of the information necessary to identify the particular card. As will be described below, the code information may be established on the card in difi'erent physical configurations and still enjoy the advantages of the invention.

As mentioned above, the transducer 12 functions to receive the card 11 and transduce the information mechanically established thereon into a serial pulse signal formed by bursts of audiofrequency vibrations. The transducer 12 comprises a case 18 formed by case forming members 19, 21 and 22 all of which may be conveniently formed of a rigid, durable plastic material of the type well known in the an as being suitable for the purpose herein described. The case forming member 21 has a recessed, rectangular central portion 23 surrounded on three sides by a raised border 24. Recessed portion 23 is opened at its front 26--on its fourth sidesuch that when cover 19 is secured to the raised border 24 a slot is formed at the front 26 having a width slightly larger than the width of card 11 measured from the tip of a code element 17 to the tip of an opposing reference element 13. Thus the recessed portion 23 serves as a card-receiving member and as a track for guiding the card past generally circular openings 27 and 28 formed in the opposing border-forming members 24a and 24b and extending into the recessed portion 23. In order to assure that the card 11 is guided correctly into the transducer 12 the case-forming member 21 has raised rail 25 formed longitudinally along the center of recessed portion 23 while card 11 has a recessed groove 30 formed longitudinally along its central axis. when card 11 is inserted into the generator 12 the groove 30 surrounds the rail 25 whereby the card 11 is guided down the center of the generator providing a smooth insertion of the card.

The generally cylindrical opening 27 receives code element gear 31 having generally evenly spaced teeth 32 formed around its circumference. The gear 31 is pivotally secured within cylindrical opening 27 as by a pivot pin 33 with the teeth 32 extending into the recessed portion 23 for approximately 60 degrees of their travel-about pin 33. Thus when card 11 is guided into recess portion 23 code element 17 will engage the teeth 32 of gear 31 and cause the gear to rotate about its pivot 33. If, of course, a code element is not present at a code element location, the card will pass freely past the gear teeth until a code element does occur to engage the gear. Thus gear 32 will be rotated as a direct function of the pattern of code elements on card 11.

Gear 36 carrying gear teeth 37 is disposed within cylindrical opening 28 in precisely the same manner as previously described with respect to gear 31 in that teeth 37 extend into recess 23 and thus engage the reference elements 13 as card 11 is inserted into recess 23 and the reference elements pass the gear 36. Unlike the code elements, however, a reference element is present at each of the reference element locations such that to the extent the reference elements are at equally spaced intervals along the edge of card 11, the gear 36 will be rotated a fixed number of rotations for a given lineal insertion of the card 11 past gear 36. If the gears 31 and 36 are at the same longitudinal position as shown, then the code element locations 16 are offset from the reference element locations 14 such that a code element location 16 passes gear 31 in between each successive pair of reference element locations passing gear 28. If, of course, the code element locations and reference element locations were not longitudinally offset but were rather longitudinally coincident then it would be necessary to offset the gears 31 and 36 so that a code element location presents itself to the gear 31 between reference element locations presenting themselves to gear 36 as opposed to such code element locations and reference element locations being presented simultaneously to their respective gears. In either arrangement, the rotation of gears 31 and 36 discloses the pattern of code elements since by noting the presence or absence of rotation of gear 31 for successive rotations of gear 36 the code element pattern is discernable.

A pair of detent mechanisms 41 formed by spring members 42 with sections 43 disposed to engage the gears 31 and 36 operate to limit the rotation of the gears to a single step for each engagement of an element with a gear. The gear 36 is rotatably pinned in place by a pin 39 precisely in the manner described with respect to gear 31 and pin 33.

The lower cover member 22 of case 18 includes a pair of recessed openings 46 and 47 into which a code pulse generating tone arm 51 and a reference pulse generating tone arm 52 extend respectively providing an open space in which the tone arms are free to vibrate. Tone arm 51 which may be conveniently constructed of an appropriate metal material is selected to have a characteristic frequency of vibration which is different from the characteristic frequency of vibration of tone arm 52. Tone arm 51, for example, could be selected so as to vibrate at approximately 1,000 112. while tone arm 52 would vibrate at 1,500 I-Iz. thus providing a clear frequency spacing between the two tone arms.

Gear 31 and tone arm 51, both of which operate in connection with code elements 17, are mechanically joined through a code tone arm actuator 61 in the form of a gear having teeth 62 which set tone arm 51 to vibrating when rotated past the tone arm during which they engage the tone arm and then release it. Actuating gear 61 is secured to gear 31 for rotation therewith and is advantageously formed from metal to assure that tone arm 51 is properly actuated. Teeth 62 are spaced about the periphery of actuator 61 such that the rotation of gear 31, in response to a signal reference element 17 passing the location of gear 31, causes a single one of teeth 62 to engage and release arm 51 causing it to vibrate. If the tone arm 51 is still vibrating when the next code element 17 causes gear 31 to rotate, it will cease its vibration when engaged by the next tooth 62 and will begin vibrating again only when released by that tooth. Thus rotation of actuator 61 causes bursts of vibrations of tone arm 51 which form the audiofrequency code pulses of the serial pulse signal which the generator produces.

The tone arm 52 associated with the reference elements 13 operates in precisely the same manner described above in connection with code elements 17 in that a reference tone arm actuator 63 having teeth 64 disposed about its periphery is mechanically secured to gear 36 for rotation therewith and disposed to engage and release'arm 52 to cause the sameto vibrate at its characteristic audiofrequency for each engagement of gear 36 with a reference element 13.

The tone arms 51 and 52 are secured to the member 22 which serves as a sound board for transmitting the audio signals produced by the tone arm.

Referring now to FIGS. 3 and 4 the invention is shown in a somewhat different embodiment although the essential operating elements are substantially the same. A case 71 supports a shaft 72 on which a code element gear 73 and a reference element gear 74 are rotatably joumalled. The gears 73 and 74 are maintained a fixed distance apart on the shaft 72 by a spacer cylinder 75 disposed on the shaft between the gears. Gears 73 and 74 are disposed to engage the code element sprocket holes 76 and reference element sprocket holes 77, respectively, formed in a card 78. The card 78 corresponds to the programmer ll of the embodiment of FIGS. 1 and 2 while the reference holes 77 correspond to the teeth 13 and the material between holes 76 corresponds to teeth 17 both previously described.

A pair of guide rails 80 and 85 are provided along the interior sides of case 71 for receiving and guiding card 78 smoothly past gears 84 and 81. Guides 80 and 85 have U-shaped cross sections and are aligned with opening 91 whereby card 78 automatically enters the guides when inserted in the case openmg.

The gears 73 and 74 have affixed thereto for rotation therewith, actuators in the form of gears 81 and 84 respectively. A code tone arm actuator 81 secured to gear 73 operates when rotated to actuate a code tone arm 82 mounted within the case on a mounting 83. Similarly, a reference tone arm actuator 84 secured to gear 74 for rotation therewith operates to actuate a reference pulse tone arm 86 mounted within casing 71 by mounting 87. As the card 78 is inserted in the slot 91 in case 71, the card material between sprocket holes operates to rotate the associated gear and thus cause the associated tone arm to vibrate by operation of the intermediate actuator. The code sprockets are varied in pattern by eliminating the card material between adjacent sprocket holes for selected ones of such holes. Thus the material between adjacent sprocket holes represents code element locations and the presence or absence of material between sprocket holes represents the present or absence of a code element respectively. There are, of course, no eliminated sprocket hole separations in the case of the reference sprocket holes just as there were no reference elements deleted from the reference element locations 14. The absence of a code element (material between adjacent sprocket holes removed) will allow that portion of the card to traverse the gear 73 without causing rotation thereof and thereby establish the absence of a code element at that location. Once again, the code element locations and reference element locations are advantageously offset from one another to produce the required time-space relationship. By offsetting the sprocket holes as recommended, code elements will be presented to the code gear 73 between successive reference elements being presented to gear 74 whereby the presence or absence of a code element can be discerned. The tone arms 82 and 86 operate essentially identically with that described with respect to tone arms 51 and 52 and should be selected to have characteristic vibrations in the audio range at different frequencies, preferably not harmonics of each other.

Both the cars 78 and the card 11 are suitable for programming by the user since the teeth 17 can be readily removed as can the spaces between selected sprocket holes 76. Depending on the use to which the system is being out, it may or may not be recommended that the user be encouraged to change the program which may have been established on the card previous to its being issued. The embodiment of the programmer utilizing sprocket holes has the advantage of reducing the possibility of the program being changed by a tooth accidentally being knocked off. There are, however, numerous other physical means by which the reference and code pulses could be established on a card, such as by protrusions or the like, and the invention is not necessarily limited to any form thereof and is limited only to the extent set forth in the claims set out hereinbelow.

While the disclosure above has dealt primarily with the programmable elements of the present invention and leaves the actual program selected to the user to best suit his needs, it should be pointed out that a distinguishable start code should precede the programmed code itself. Numerous such distinguishable codes can easily be provided such as two consecu-- tive code pulses with no intervening reference pulse. This would be recognized by the receiving system as a signal to indicate that the following pulses were to be examined to determine if they presented the proper code.

I claim:

1. An acoustical signal generator comprising in combination:

a transducer programmer having a plurality of code element locations with code elements present at selected ones of said locations establishing a code element pattern thereon and a plurality of reference element locations with reference elements present at each of such locations establishing a reference element pattern thereon;

a program transducer for mechanically receiving said trans ducer programmer and having audiofrequency tonegenerating means operative in response to receipt of said programmer by said transducer to generate a series of audio pulses corresponding to the code element pattern of said programmer and a series of audio pulses corresponding to to the reference element pattern, wherein the frequency of said code element pulses is different from the frequency of said reference element pulses.

2. The acoustical signal generator of claim 1 wherein said audiofrequency tone-generating means comprises:

a code tone arm operative when actuated to vibrate at a particular audiofrequency;

a reference tone arm operative when actuated to vibrate at a particular audiofrequency which is different from the frequency at which said code tone arm vibrates;

a code tone arm actuator means disposed in operative association with said code tone arm and responsive to a code element to actuate said code tone arm; and

a reference tone arm actuator means disposed in operative association with said reference tone arm and responsive to a reference element to actuate said reference tone arm.

3. The acoustical generator of claim 1 wherein the reference element pattern and the code element pattern are established on said programmer relative to one another so as to interact with said tone-generating means to have it respond alternatively to reference element locations and code element mime Mn:

locations so as to establish a series of audio pulses each separated in time from one another whereby the particular code element pattern is established by the presence or absence of code audio pulses-between successive reference audio pulses.

4. The acoustical generator of claim 3 wherein; said programmer is further defined as a generally rectangular rigid plastic card; and

said program transducer is further defined as including generally flat case member with a slot and track formed therein for receipt and guidance of said card.

5. The acoustical generator of claim 4 wherein said code and reference elements are established on said card by sprocket holes with selected ones of said holes joined by removing the card material therebetween wherein a pair of sprocket holes separated by card material defines an element.

6. The acoustical generator of claim 4 wherein said code and reference elements are established on said card in the form of teeth on the edge of said card.

7. The acoustical generator of claim 4 wherein said transducer is further defined as having;

a pivotally mounted code element gear within said case to engage said code elements as said card is inserted into said case;

a pivotally mounted reference element gear within said case to engage said reference elements as said card is inserted into said case;

a code pulse generating tone arm secured in said case so as to be free to vibrate when actuated to generate a code pulse at its characteristic frequency of vibration;

a reference pulse generating tone arm secured in said case so as to be free of vibrate when actuated to generate a reference pulse at its characteristic frequency of vibration which is selected to be different from that of said code pulse generating tone arm;

a code tone arm actuator mechanically coupled between said code element gear and said code pulse generating tone arm and operable in response to rotation of said code element gear to actuate said code tone arm; and

a reference tone arm actuator mechanically coupled between said reference element gear and said reference pulse generating tone arm and operable in response to rotation of said reference element gear to actuate said reference tone arm.

UNETEE STATE Mew? wleli fifilllflllwllll @EF Patent N0. 3 628 499 v 1 Dated December 21, 197i Inventofls) Konrad I-I; Benford It is certified that error appears in l the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 48, change "mac'ia-z to --make-*a Column 6, line 17, change out" to --puco Column 6, line 55 Claim 1, change to to" to --co--u Column 8, line 9 Claim '7, change "free of to --free "to---a filgned and sealed this 23rd of May WK? Afiteet:

EDWARD EQGFLETSE-ZER JR; GZQTTSGPLMZQ Attesting Officer 1 Com issioner of Petente FORM P046556 (10-69) USCOMM-DC 60376-P69 us. GOViRNMENT PRINTING OFFICE i965 O'365-33A JL-h-M Patant NO 3,,628 7499' fied that error appears in the ahove-identif1efi patent LCCC-EI'S Patent are hereby correctel as shown below:

It is ca'fi and that said Le line 48, change made to -"mak&"'

Ccalumn Colman 6 line; 55 V Claim 1, change to tc to ----w--.,

UELCOMM-DC 6OS76-Piv9 us. GOViR-NMENT PRiH'HNG OFFiCE: 19w o-3sa-33n

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6742713May 26, 2000Jun 1, 2004Deutsche Telekom AgAccess controlled system with acoustic mechanical verification transmitter
US7251339 *Mar 31, 2004Jul 31, 2007Gennum CorporationWireless remote control for a hearing instrument
US20040196993 *Mar 31, 2004Oct 7, 2004Ryan James GregoryWireless remote control for a hearing instrument
WO2000075880A1 *May 26, 2000Dec 14, 2000Deutsche Telekom AgAcoustic-mechanical verification transmitter
Classifications
U.S. Classification116/137.00A, 84/98, 367/197, 116/169, 200/292, 200/46
International ClassificationG10K1/00, G05B19/04, G07F7/08, G05B19/06, G10K1/072
Cooperative ClassificationG07F7/086, G10K1/072, G05B19/063
European ClassificationG07F7/08B, G05B19/06B, G10K1/072