US 3875738 A
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Description (OCR text may contain errors)
United States Patent [191 Ichikawa et al.
l l WATCH WITH BUILT-IN AUDIO ALARM DEVICE  inventors: Shingo lchikawa, Sayama; Humio Takeuchi; Hideyuki Kawashima, both of Tokyo. all of Japan  Assignee: Citizen Watch Co.. Ltd.. Tokyo.
Japan  Filed: Mar. 1, 1974 [2'll App]. No.: 447,410
[ 1 Apr. 8, 1975 3,032.65] 5/1962 GisigerStahl et al l, 58/152 R X 3.352JU2 ll/l967 Schneider 58/575 X -1733.804 5/l973 Diersbock i. 58/575 X [57) ABSTRACT This invention relates to an alarm watch adapted for Foreign pp Priomy Dam delivery of voice frequency alarm signal by the use of Mar. 3. i973 Japan H 48-25555 a built-in miniaturized audio machine, preferably a June I9. 1973 Japan .i 48-69033 cartridge endless tape type magnetic tape recorder. The watch is fitted with a built-in speaker, working  US. Cl. .5 58/575 magnet and moving coil which are shaped into respec- ISI] Int. Cl. G04b 23/l2; G04c 2l/34 tive cylindrical forms thereby providing a large idle [58} Field of Search 58/38, 57.5, l52 R 152 B Space within the watch case for receiving the watch movement or the audio machine.  References Cited UNITED STATES PATENTS 7 Claims. 9 Drawing Figures 2.644.294 7/1953 Ditisheim 58/575 a? 5 '7' h 1 4c 48 l U PATENIEDAPR 3:975
SHKET 1 OF 3 FIG. 2
PATENTEUAPR 8|S75 3,875,738
WATCH WITH BUILT-IN AUDIO ALARM DEVICE BACKGROUND OF THE INVENTION This invention relates to an alarm watch adapted for delivery of a voice frequency alarm signal by the use of a builtin miniaturized audio machine, preferably a cartridge endless tape type magnetic tape recorder.
In the past, alarm watches have been designed and arranged to deliver a higher frequency alarm signal than a voice frequency, on account of the difficulty in the provision of a proper speaker which must be built into the watch. Such miniaturized speaker must have the largest possible vibratory or oscillatable membrane which cooperates with a centrally arranged moving coil-working magnet assembly. Such a speaker structurc. however conflicts with the time-indicating hands mechanism of the watch.
It is therefore a main object of the present invention to provide an alarm watch adapted for delivery of a voice frequency alarm signal.
This and further objects. features and advantages of the invention will become more apparent as the description proceeds.
For fulfilment of the above and further objects the alarm watch comprises a watch case, a watch movement contained therein. a speaker built into said watch case. an alarm setter operated from said watch movement. and an audio machine operativcly connected with said alarm setter and electrically connected with said speaker. this invention being characterized by the working magnet and moving coil being shaped into respective cylindrical forms defining a large idle space within said watch case so that either said watch movement or said audio machine is positioned practically in said idle space.
As an advantageous embodiment of the invention, said moving coil is fixedly attached to an oscillatable membrane which is supported at its outer periphery on and by said watch case in such a way that the cylindrical coil is arranged concentrically to the latter.
Asa further advantageous embodiment of the invention. said cylindrical working magnet is mounted in a concentric ring groove formed in said watch case and in proximity to the inside wall surface of the latter, leaving a cylindrically shaped magnetic gap in which a substantial part of said moving coil is positioned. The magnetic circuit including said working magnet consisting of a permanent magnet passes through the material of said watch case.
As a still further advantageous embodiment of the invcntion, said audio machine is either a miniaturized. endless tape cartridge type magnetic tape recorder or a miniaturized radio receiving set.
In the former case the speaker is designed and arranged as a speaker microphone by which the user of the watch can record his voice message on the tape for the purpose of a later delivery the alarm signal.
In the alarm watch according to this invention said oscillatable membrane is transparent for viewing timeindicating hands and a watch dial. The audio machine is operated for a predetermined period of time upon operation of said alarm setter under the influence of a timer.
These and further objects, features and advantages will become more apparent when reading the following detailed description of the invention by reference to the accompanying drawings illustrative of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. I is a plan view of a watch fitted with a built-in loud speaker designed and arranged in accordance with the principles of the present invention.
FIG. 2 is a section of the watch shown in FIG. 1, taken along a section line II-II' shown therein and illustrated with a somewhat enlarged scale.
FIG. 3 is an enlarged partial plan view of FIG. I. wherein, however, the plastic glass cover has been partially broken away for clear representation of several parts of the built-in loud speaker.
FIG. 4 is an enlarged plan view of a miniaturized magnetic tape recorder unit acting as an audio alarm machine and built into the watch for cooperation with the speaker.
FIG. Sis a plan view ofa motion-teansmitting mechanism opcratively arranged between the watch movement of said watch and said magnetic tape recorder unit, said mechanism being illustrated on a slightly reduced scale relative to that of FIGv 3.
FIG. 6 is an enlarged sectional view taken along a broken section line VI-VI' in FIG. 5.
FIG. 7 is an electronic circuit arranged in the magnetic tape recorder shown in FIG. 4.
FIG. 8 is a source battery circuit arranged in the magnetic tape recorder.
FIG. 9 is a perspective view of a ring magnet employed in the loud speaker.
DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS. I 3, numeral I represents a conventional watch movement shown only schematically by its outline configuration. Numeral 2 represents a conventional time-indicating dial on which hour minute and seconds hands are rotatably mounted as shown at 19a. 19b and 190, respectively, in FIGS. I and 3, and at I9 in a grouped manner in FIG. 2. The movement I is fixedly mounted on a holder plate 3 by means of a plurality of set screws I4, said holder plate being in turn fixedly attached to a case band 4 by means of a plurality of set screws 13.
The case band 4 is made ofa high permeability material such as soft iron, permalloy, cobalt platinum alloy or the like and formed with a concentric ring groove 4f leaving a ring pole 4a and representing an outer ring wall surface 4b. A permanent magnet 5 shaped into a hollow ring radially magnetized is fixedly secured into said groove 4fin tight contact with said wall surface 4b. A ring-shaped idle gap is seen between the magnet 5 and the magnetic pole 4a. A movable coil 17 shaped into a hollow cylinder is inserted from above into this idle gap, said coil being fixedly attached to a transparent membrane 16 by applying a glueing agent. This membrane 16 is in turn fixedly attached at its periph eral zone to a supporting ring member 18 by application of a glueing agent. A vibratory member 23 is constituted by the combination of these two members I6 and 17. The supporting ring 18 is fixedly attached at 4c by glueing to the case band 4 which carries fixedly at 40' a bezel 8.
Plastic glass cover 6 is formed with a number of perforations 6a and a shielding ring plate 7 is attached fixedly at its outer peripheral ring area on its inside surface by means of a glueing agent, for the prevention of viewing the speaker from outside of the watch by a viewer. The cover 6 is fixedly attached to the bezel 8 as usual by a press fit or a similar attaching measure.
Numeral 10 represents a conventional back cover which is screwed at 10a on the open bottom of case band 4 a sealing rubber ring 11 being provided as shown for preventing invasion of moisture from outside.
Numeral 9 represents a magnetic tape recorder unit as a representative embodiment of an electronic audio instrument set which may be, when desired, a miniaturized radio receiving set or the like, although not shown. This tape recorder 9 is positioned below the movement support 3. The detail structure and operation of this tape recorder will be described more fully in the following as the description proceeds.
Numeral represents a conventional time-setting and winding stem, and 21 and 22 a record operation stem and a playback operation stem, respectively, as will be more fully described hereinafter.
The loud speaker comprises mainly said vibratory member 23 and a magnetic circuit including said idle gap and as described can oscillate by supplying audio signal current from the unit to said movable coil 17 and the audible output signal issued by the oscillating movement of the membrane 16 which may be of polycarbonate. polypropylene or the like material, is dissipated through the perforations 6a to outside of the watch.
In FIG. 4, numeral 26 represents a base plate; 27 an endless tape; 28 a tape magazine containing a roll of tape from which the tape 27 has been taken out and threaded through several tape guides 33!), 33c, 33d, capstan 30 and a tape guide 33a; and 29 a drive motor. The motor directly drives conventional capstan 30. This motor 29 drives at the same time and through a reduction gearing, not shown, a control cam 31 for the control of the endless tape 27, as will be more fully described hereinafter.
Numeral 34 represents a back tension roller kept in rolling contact with the tape 27 at tape guide 33d and freely rotatably mounted on the tip end of a spring arm 34a the root portion of which is fixedly mounted at 100 on the base plate 26.
A recording and reproducing magnetic head 35 is kept in sliding contact with the tape 27 which is urged to keep this contact by means of a pad 36 mounted on a spring arm, 360, the root portion of the latter being fixedly mounted at 36b and 366 on the base plate 26.
Numeral 37 denotes a magnetic eraser head kept in sliding contact with the tape as shown in the course of the magnetic recording stage. This head 37 comprises a permanent magnet mass, in the present specific embodiment, said mass being mechanically connected with the recording and reproducing change-over stem or knob 21. By manually drawing out this knob 21, the eraser head can be retracted from its contacting position. For this purpose, this knob 21 has been constructed and arranged in the similar manner with the conventional time-setting and spring-winding stem of the watch, as at 20, although not specifically shown and described.
A block represents an audio signal amplifier circuit as conventionally employed in magnetic tape recorders and will be more fully described hereinafter by reference to FIG. 7.
A further block 38 represents a conventionally known electronic speed control circuit comprising transistor means adapted for sensing the rotational speed of the motor 29 and interrupting source battery 39, FIGS. 7 and 8, when the motor speed exceeds a we determined upper limit and reconnecting the battery again when it drops beyond said limit, as known per se, although not specifically shown and described by virtue of its very well known nature.
Numeral 40 represents an on-off control switch which is a follower to said cam 31 and adapted at its onposition for supplying current from said source battery 39 to said both circuits 25 and 38 and vice versa. The switch 40 is formed with a resiliently supported projection 40a adapted for cooperation with a recess 31a formed on the peripheral surface of said cam 31.
In the following, the operation of the miniaturized magnetic tape recorder shown substantially in FIG. 4 will be described, together with several further constituent parts thereof.
This tape recorder is of the endless tape, constant time recording and constant time playback type. In the off-service position thehreof shown in FIG. 4, the switch control projection 400 on the switch 40 is kept in engagement with a recess or notch 31a on the control cam 31, thus the switch being off. Therefore, the circuit 38 is de-energized and the motor 29 is stationary.
Under these conditions, when an alarm control switch 42, FIG. 6, is caused to close under the influence of the alarming operation derived from the watch movement, as will be more fully described hereinafter, motor speed control circuit 38 is kept energized for operation during a certain predetermined period, say 30 seconds, the motor 29 is started and the cam 31 is driven therefrom.
With rotation of the cam 31, the projection 40a is disengaged from contact with said cam notch 130, so as to close the source switch 40, thereby the both circuits 25 and 38 being self-maintained and the motor 29 continuing its rotational movement.
Upon a complete revolution of said cam 31, the projection 40a is brought into re-engagement with cam notch 31a and the source switch 40 is caused to open for de-energizing the motor 29. Thus, a complete operation cycle has been terminated.
During this one cycle period of the tape recorder operation, a predetermined length, say 51 cm, of the tape 27 passes over the magnetic head 35 which is adapted for acting as a recording head or a playback head, as the case may be.
During the recording period, the knob 12 is held at its pushed-in position as shown in FIG. 5, so as to keep the eraser head 37 in contact with the endless tape 27. When the motor 29 is brought into rotation in the aforementioned manner, and in the direction shown by an arrow B, motion is transmitted through capstan 30 to the tape which is thus caused to travel clockwise in FIG. 4. Part of the tape, being erased by contact with eraser head 37 is subjected to recording by cooperation with the head 35 acting at this stage as a recording head. The recording signal, say the watch users voice information is conveyed from the speaker 15, acting at this stage as a microphone, through the amplifier circuit 25 to the magnetic head 35, as will be more fully described hereinafter.
For initiation ofa playback operation, the knob 21 is drawn out from the shown position so as to recede the eraser head 37 from contact with the tape.
When the motor 29 is caused to rotate in the aforementioned manner, the recoded signal is picked up by the head 35 acting at this stage as a playback head as will be more fully described hereinafter. In this playback operation, the picked-up signal will be conveyed through the amplifier circuit 25 to the speaker unit from which, therefore, the corresponding audio information will be delivered through the perforations 6a to open atmosphere.
In FIG. 5, an alarm control mechanism mounted on the bottom surface of the base plate 26 is schematically shown at a substantially reduced scale relative to FIG. 4. Therefore, FIG. 5 corresponds to a reduced and inverted bottom view of FIG. 4, wherein, however, main working parts of the alarm control mechanism only have been illustrated and minor and rather superfluous parts have been omitted from the drawing only for better and clearer understanding of the invention.
in FIGS. 5 and 6, the base plate is shown at 26 as above, yet at a substantially reduced scale relative to FlG. 4 as above mentioned. This base plate is made of an insulating material. The base plate 26 is formed with recessed areas 26a, 26b and 26c and with a central noncircular opening 101.
Alarm setting knob 22 is made rigid with a stem 22a which is rotatably mounted in a bore 102 and carried at its innermost end a gear 43 preferably in the similar manner to the conventional clutch wheel, not shown. Motion is transmitted from the gear 43 through intermediate gears 44 and 45 mounted in the recess 26a, to an alarm-setting gear 46 having three small openings 46a, 46b and 46(- arranged at mutually different radial distances.
Numeral 12 represents a center wheel extension arbor which is rigid with the conventional center wheel, not shown, an alarm setting pinion 47 mounted on said arbor 12 for unitary rotation therewith. Numeral 48 represents an alarm-setting minute wheel which is rotatably mounted on a short stationary arbor 3a studded on holder plate 3.
Numeral 49 represents an alarm-setting cannon wheel which is rotatably mounted on the said alarm setting cannon wheel and formed with three projections corresponding to said three small openings 46a, 46b and 46c on the wheel 46, the said projections being, however, shown only two thereof at 49b and 49c. Minute wheel 48 consists of a gear portion 48a and a pinion portion 48!) made integral therewith, said gear portion 480 engaging with alarm-setting pinion and said pinion portion 48b engaging with said cannon wheel 49 as shown in FIG. 6. Therefore, motion is transmitted from said center wheel extension arbor 12 which makes a complete revolution per hour, to the cannon wheel 49 at a specifically reduced rate of a complete revolution per 12 hours.
A switching spring arm 51, an insulating washer 52 and an alarm-setting spring 50 are fixed mounted in a stack on the base plate 26 by means of a set screw 53, said spring 50 having a semicircularly curved end portion kept in pressure engagement with the wheel 46 urging the latter from upper in FIG. 6 towards cannon wheel 49.
Leads 54 and 55 connects electrically the springs 50 and and S1 to respective terminals 56 and 57 which are shown also in FIG. 8. These springs 50 and 51 constitute in combination an alarm-setting switch 42 shown in FIG. 8.
Alarm-setting wheel 46 is provided thereon with an hour time scale 46d which is visible through a transparent window 10b formed through back cover 10.
The operation of the alarm-setting device substantially shown in FIGS. 5 and 6 is as follows.
For performing an alarm-setting operation, the user of the watch turns the knob 22 to the desired degree by viewing the time scale 46d through the window 10b, thereby motion being transmitted from the knob through successive members 43 46 to the wheel 46. Therefore, the user can set any desired alarm time. For this purpose, an indicating arrow or the like representation is provided at the window 10b or so, although not shown.
With regular operation of the watch movement 1, the extension arbor 12 rotates a complete revolution per hour which rotational movement is transmitted through wheels 47 and 48 to cannon wheel 49 which makes a complete revolution per 12 hours.
When the small openings 460 46c on alarm-setting wheel 46 are brought into registration with the corresponding small projections as at 49!); 49c on the cannon wheel 46, the latter is resiliently depressed under the spring force at 50 so that the both wheels 46 and 49 are brought into direct contact with each other and the both springs 50 and 51 are also brought into mutual contact for current conveyance. Thus, the alarmsetting switch 42 is brought into its closed position. Thus, the tape recorder will start to perform a recording or playback service, as the case may be, depending upon the previously selected axial position of the knob 21.
In FIG. 7, speaker-microphone unit 15 comprises the parts 4a, 5, l6 and 17 shown most clearly in FIG. 2. 35 represents schematically a recording and reproducing magnetic as before. S, and S represent a pair of change-off switches which are commonly controlled by manipulation of the knob 21. The full-line position of these switches corresponds to the recording service of the tape recorder as shown in FIG. 4, while the dotted line position of these switches corresponds to the playback service of the tape recorder. Thus, stationary contacts A, and A of these switches serve for the re cording service, while stationary contacts B, and B serve for the playback service.
60 represents a voltage amplifier which serves for the amplification of the audio signal current 61 represents a power amplifier which serves for the drive of the speaker. These amplifiers 60 and 61 provide in combination a signal amplifier. 40 represents said source switch which is adapted for connection of source battery 39 for the desired operation, as was briefly set forth hereinbefore and as will be more fully described hereinafter.
62 represents a conventional high pass filter which is effective during the recording service. 63 represents a feed-back circuit for the generation of alarming sounds. 64 represents an analogue switch adapted for connection of said circuit 63 to said power amplifier circuit 61 necessary for the oscillation job. 65 represents a timer circuit adapted for operation for a certain time period, such as 30 seconds as was referred to, to on-off-control of the said analogue switch 64 upon actuation of said switch 40. Numeral 66 represents a signal detector adapted for operation upon reception of the output signal from the power amplifier 6] so as to on-off control of an illuminating diode 67.
The aforementioned several constituents are electrically connected as shown. thus the mutual wiring connection could be well understood without further analysis thereof.
The operation of the audio circuit shown in FIG. 7 is as follows.
In the case of the recording service. the knob 21 is pushed-in to the position shown. as was referred to hereinbefore. By this operation. said switches S and S: are set to their respective full line position. Therefore. the unit is connected as a microphone to the inlet of the voltage amplifier 60 through stationary contact B while the magnetic head is connected through stationary contact A, and the compensator 62 to the output side of the power amplifier 60.
With the on-position of said switch by the manipulation of knob 21 the source battery is connected to all the circuits. Then. the potential at gate terminal 69 of inverter 68 constituting said timer circuit will rise up exponentially depending upon the time constant provided by the combination of resistor 70 and capacitor 71. During such operational period that the potential at gate terminal 69 does not reach the reverse operation level of said inverter 68, the output 72 of inverter 68 is held at the source voltage level. Therefore. switching transistor 73 constituting said analogue switch 64 is held on through a bias resistor 74. and power amplifier 61 and feedback circuit 63 constitute in combination an oscillator circuit. the oscillation being made dependent upon the time constant as determined by the combination of a resistor 75 and a capacitor 76 included in the feedback circuit 63. The thus provided oscillation signal is conveyed through a complying condenser 77 to signal detector circuit 66 which comprises a switching transistor 78. a bias resistor 79, an illuminating diode 67 for signal representation and a current limit ing resistor 80 which are mutually connected as shown.
With no input signal impressed. switching transistor 78 is kept in its oft condition. and thus. the diode 67 does not illuminate. and vice versa.
When it is assumed that the frequency of the aforementioned oscillation be 3 kHz. the diode 67 will be seen visually to a viewer as if it illuminates continu ously. from which operation the viewer can be aware of the oscillating state ofthc sensing circuit 66. The oscillating operation will continue until the switching transistor 73 of said analogue switch 64 becomes off upon attainment of the potential at gate terminal 69 at the operation reversing level and by the inversion of the potential at output 72 to earth potential.
The user. therefore. can initiate a recording opera tion by directing his oral message towards the speakermicrophone unit upon operation of the knob 21 in the aforementioned way and upon observation of termination of the illuminating operation at diode 67.
The voice signal presented to said unit 15 will be converted into a corresponding electrical signal therein and conveyed through switches S and S to voltage amplifier 60 and the amplified signal is further conveyed through compesnator 62 to magnetic head 35 which thus performs recording operation on the tape 27 as usual.
On the other hand. part of the output signal from amplifier 61 is conveyed to signal detector circuit 66 for energizing the illuminating diode 67 according to the voice frequency by which the user can acknowledge the recording operation for safety,
Upon lapse ofthe recording operation for a predetermined constant period. 30 seconds in the present embodiment as determined by a complete revolution of the foregoing control cam 31 on the miniatured tape recorder. source switch 40 is turned off as in the aforementioned way. so as to terminate the recordation.
In order to initiate a playback operation, the user draws out the knob 21 to keep the eraser head from contact with the tape, and at the same time. to transfer the switches S, and S. from their full-line position to their dotted line position in FIG. 7. Any person skilled in the art could easily understand the playback mode of the tape recorded by consulting the foregoing description by reference to FIG. 7. even without further detail analysis thereof.
In FIG, 8, numeral 81 represents a source circuit including the source battery 39. The alarm-setting switch is shown again at 42. Numeral 82 is a further switch which is closed when the knob 21 is operated to its record job position. Source switch is shown again at 40.
Numeral 83 denotes a switching circuit which comprises a PNP-switching transistor 84, a further and inverting transistor 85 for control of the operation of the latter and a still further transistor 86 for performing a timing control job. These three transistors 84. 85 and 86 are connected mutually as shown. A load resistor 87 is connected in the collector passage of said lastmentioned transistor 86 and a condenser 88 is connected to the base electrode thereof. the opposite side of said condenser being as a common emitter to the transistors 86 and 85. A charging resistor 89 is connected in parallel to said load resistor 87. In this circuit 81, the emitter at 90 and collector at 91 of said transistor 84 are connected across the switch 40. The emitters of said transistors 85 and 86 and the opposite side of said condenser 88 are connected to a common terminal 92. The outer ends of said resistors 87 and 89 are con nected to a further terminal 93 which is connected in parallel to respective stationary contacts, only one of them being shown at 56, of switches 42 and 52.
conventionally designed audio signal amplifier circuit 25 and electric speed control or motor drive circuit 38 shown only schematically in FIG. 4 by their outline configuration are illustrated in FIG. 8 only in a further simplified rectangular blocks. As shown. these circuits 25 and 38 are connected to the circuit 81 at its loads.
The operation of the source circuit 81 is as follows,
Now. it is assumed that switch projection 40a is kept in precise engagement with cam notch 31a so that source switch 40 is opened and that further two switches 42 and 82 are also kept in their open position as shown in FIG. 8. In this case. switching circuit 83 is off. because there is no source voltage at the terminal 93, thus the switching transistor 84 being off. No current will be supplied to the both load circuits 25 and 18.
When switch 42 or 82 is closed. source voltage is conveyed to the terminal 93 and the transistor 85 is biased through resistor 87 and turns on. Therefore. the transistor 84 connected with the collector of transistor 85 turns equally on. Therefore. source voltage is fed through the transistor 84 to the load circuits 25 and 38. With energization of motor drive circuit 38, cam 31 will operates and source switch 40 is closed and self maintained.
With application of source voltage to said terminal 93, the base potential at transistor 86 will rise up exponentially depending upon the time constant defined by resistor 89 and condenser 88 until, upon lapse ofa predetermined period, say 30 seconds in this specific embodiment. it reaches the operation-reversing voltage of transistor 86. At this instance, the transistor 86 reverses its state from off to on which results in the reversed state of transistor 84 from on to off through the intermediary of transistor 85. Therefore, the application of source voltage of transistor 84 will be terminated. However, at this stage, the source switch has been selfmaintained at its closed state, current will be nevertheless supplied to the both load circuits 25 and 38.
This operational conditions will be terminated upon completion of one cycle operation of the miniatured tape recorder, so so to bring the source switch 40 into its released position under the influence of the cam operation at 31, as was referred to hereinafter.
The electrical charge accumulated in the condenser 88 will be self-released after opening of both switches 42 and 82 through the leak resistance at the same condenser 88.
The use of PNP-transistor at 84 is for such reason that the unavoidable voltage loss as met during the switching service is rather smaller than with use of NPN-transistor.
In FIG. 9, a most preferably embodiment of the ringshaped permanent magnet is shown.
In this embodiment. a number of magnet pieces 58 are arranged into a circle and fixed together such as, by glueing at 59. A preferably material may be a samarium-cobalt alloy, showing a magnetic anisotropy and representing higher values of BH- area and coercive force. These magnetic segments 58 must have easily magnetizable directionality as shown representatively by small arrows A in FIG. 9. The completed magnet 5 has been magnetized to have N-poles on its inner periphery and S-poles on its outer periphery, as a representative example. In this way, a rather powerful magnet can be provided at a rather cheap price. Further, in this way, the clectromagnetically cooperating and oppositely arranged surfaces of the magnet and moving coil can be made broader than otherwise. By adopting these means, a sufficiently powerful audio output can be obtained without undue increase of the height or thickness of the watch.
In the foregoing specification, the magnetic tape recorder was used as a representative of the audio machine. It is very easy to replace a miniatured radio receiving set for the tape recorder, when necessary. to any person skilled in the art, although a more specific analysis has been omitted from the foregoing specification for the reason of simplicity of its disclosure. Naturally, in this case, minor change of design and arrangement of the related other parts would be necessary.
The tape recorder shown in FIG. 4 has a overall diameter 36 mm when measured at its base plate 26, as an example. Other constituent parts have been drawn substantially in their dimensional relationship relative to that of the base plate.
The tape speed may be 17 mm/sec. The recordplayback head 35 may have overall dimensions of 8 X 7 X 5 mm. The drive motor 29 may have a diameter of 13 mm and a height of 6 mm. Tape magazine 28 may have a diameter of 7 mm and a thickness of 4 mm. The battery 39 may have a diameter of ll.6 mm and a thickness of 5.3 mm.
The movable coil 17 may be of 100 turns of u-copper wire, having a coil diameter of 30.6 mm and coil thickness of 230 p" Magnetic gap may be 600 a.
When necessary, the watch movement, can be arranged at the shown position of the audio machine 9 in FIG. 2, so as to arrange the latter at an upper position occupied by the watch movement shown in FIG. I. In this case, the audio machine must have a smaller overall radial dimension than illustrated and instead, the watch movement may have a rather larger diametral dimension.
The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:
1. An alarm watch comprising a watch case, a watch movement contained therein, speaker means built into said watch case, alarm setting means operatively connected to and driven by said watch movement, audio means mounted in said ease and operatively connected with said alarm setting means, current source means, said speaker means being electrically connected with said audio means and said current source means and comprising a vibratory membrane, supported by said watch case, a cylindrical permanent magnet having a ring pole mounted on said watch case and a cylindrical movable coil secured to said membrane for vibratory movement relative to said magnet, said cylindrical magnet and ring pole defining a central cylindrical space in which said watch movement is located, said alarm setting means being adapted to initiate operation of said audio means by operation of said watch movement whereby audio signals from said audio means are applied to said movable coil of said speaker means for vibrating said membrane to generate an audio output therefrom.
2. An alarm watch as set forth in claim 1 wherein said membrane is made of transparent material.
3. An alarm watch as set forth in claim 1 wherein said ring pole is integral with and concentrically spaced from said cylindrical magnet to define a cylindrically shaped magnetic gap in which said movable coil is positioned.
4. An alarm watch as set forth in claim 1 wherein a magnetic circuit is formed which includes said permanent magnet and the material of said watch case.
5. An alarm watch as set forth in claim 1 wherein said audio means is comprised of a miniaturized endless tape cartridge type magnetic tape recorder.
6. An alarm watch as set forth in claim 1 wherein said audio means is comprised of a miniaturized radio receiving set.
7. An alarm watch as set forth in claim I wherein said alarm setting means include cam operated switch means for operating said audio means for a predetermined period of time.