Patent Publication Number: US-3879932-A

Title: Device for generating time signals

Description:
United States Patent Kimura et al.  
 [73] Assignee: Kabushikikaisha CopaLTokyo,  
 Japan [22] Filed: Apr. 24, I974 [21] Appl. No.: 463,526  
 Related US. Application Data [63] Continuation in-part of Ser No. 27l.705, July l4.  
 I972, abandoned [30] Foreign Application Priority Data July l9. l97l Japan 46-6356l [52] US. Cl 58/50 R; 340/338; 58/23 R [5 l] Int. CL ,1G04b [9/30 [58] Field of Search 318/600-602;  
 307/l06, [32 R. l4l; 235/96, 92; 58/23 R.  
 23 A, 23 AC, 23 V, 23 D, 24 R 33, 50 R;  
 206/38 CA, l4 11 BA; 340/339, 309 338 {56] References Cited UNITED STATES PATENTS 2.720.6l9 10/1955 James 318/602 )4 2,958,028 lU/l960 Smith 1 1 3l8/6U2 3,0l5.094 l2/l96l Reynolds 340/338 3242270 3/1966 Volkenburg et a]. 200/14 X 3 456.l23 7/1969 Pihl 1 1 4 307/l4l 3585.375 6/l97l Hedrick .7 235/92 R DEVICE FOR GENERATING TIME SIGNALS Inventors: Sachio Kimura; Yoshiaki Aoki, both of Tokyo, Japan 1451 Apr. 29, 1975 Primary Examiner-Richard B. Wilkinson Assistant E.\&#39;aminerU. Weldon Attorney, Agent, or Firm-Hans Berman; Kurt Kelman [57] ABSTRACT Device for generating time signals to be supplied to indicator units which digitally indicate the time in terms of hour and minute. The device has an hour shaft rotated intermittently at intervals of 60 minutes so that it rotates one complete revolution during 24 hours, and a minute shaft rotated by one revolution per 60 minutes. An hour contact mounting plate having a plurality of contacts mounted on both sides thereof and a minute contact mounting plate having a plurality of contacts mounted on both sides thereof are secured to the hour shaft and the minute shaft, respectively. A pair of printed hour pattern mounting plates and a pair of printed minute pattern mounting plates are located on either side of the hour and minute contact mounting plates. respectively. Annular segmental conducting portions on the pattern mount ing plates cooperate with the respective contacts of the contact mounting plates so that a potential continuously applied to one conducting portion is intermittently applied to lead-out conductors connected to the remaining conducting portions through said contacts The patterns on the pattern mounting plates are such that the resulting signals on the lead-out conductors are in a code suitable for application to the indicator units,  
 7 Claims, 10 Drawing Figures IV V T I lOe lOd PATENTEBAPRZSWS 3,879,932  
 SHEET 1 if 7 PATENTEDAPRZSIHYS 3.879.932  
 SHEET [If 7 DEVICE FOR GENERATING TIME SIGNALS This application is a continuation-in-part of our copending application Ser. No. 271,705, filed July 14, 1972, and now abandoned.  
 BACKGROUND OF THE INVENTION The present invention relates to a device for generating binary code signals to be supplied to indicator units which digitally indicate the time in terms of hour and minute.  
  We have disclosed a device of the type described in US. Pat. No. 3,756,016. The device disclosed in this patent is provided with a plurality of cams adapted to be rotated a revolution per 24 hours and per 60 minutes and the corresponding number of switches each cooperating with the respective cam, the condition of the combination of contacting and non-contacting states of the switches as actuated by the respective cams being utilized as binary code signals supplied to the binary circuit so as to indicate digitally the time in terms of hour and minute. Since the device incorporates a plurality of cams and switches, the device requires a relatively large space making it difficult to construct the device compact while the manufacture of the device is made difficult.  
 SUMMARY OF THE INVENTION The present invention aims at the improvement of the device described above.  
  The object of the present invention is to provide a novel and useful device of the type described above which is compact and simple in construction and easily manufactured.  
  The above object is achieved in accordance with the present invention by the provision of a device for generating binary code signals in a binary circuit for indicating the time in terms of hour and minute, characterized by a plurality of annular patterns having projecting portions which are formed on printed pattern mounting plates and a corresponding number of contacts mounted on contact mounting plates and each cooperating with the respective patterns so as to obtain the combination of contacting and non-contacting states utilized as the binary code signals, either of the printed pattern mounting plates or the contact mounting plates being rotated a revolution per 24 hours and 60 minutes so that the time is indicated digitally in terms of hour and minute by means of the indicator units supplied with the binary code signals.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic side view showing an embodiment of the device for generating signals constructed in accordance with the present invention;  
  FIGSv 2 to are fragmentary views showing the configuration of various patterns on the printed pattern mounting plates of FIG. 1, FIG. 2 being shown as seen from line IIII, FIG. 3 shown as seen from line III-III, FIG. 4 shown as seen from line lV-IV, and FIG. 5 shown as seen from line VV. respectively;  
  FIGS. 6 and 7 are fragmentary views showing the arrangement of the contacts mounted on the contact mounting plates of FIG. 1, FIG. 6 being shown as seen from line VI-VI, and FIG. 7 shown as seen from line VIIVII, respectively;  
  FIG. 8 is a diagram showing binary code for indicating the numeral in the figure of tens of hour, the numeral in the figure of ones of hour, and numeral in the figure of tens of minute, and the numeral in the figure of ones of minute, respectively;  
  FIG. 9 is a diagram showing the combination of contacting and non-contacting states of the contacts for indicating the time; and  
  FIG. 10 is a diagram showing the prior art indicator units as connected to the present invention.  
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Before proceeding to a detailed discussion of the pre ferred embodiment of the present invention, its interconnection with the prior indicator units will be shown in brief with reference to FIG. 10. FIG. 10 shows four standard seven seqment indicators, 101-104. Each segment, 0, b, c, d, 2.1&#34;, g (shown for unit 104 but of course identical in all other units), furnishes a visual output when a voltage is applied to the corresponding input line. The indication of each digit from O to 9 is achieved by applying voltages to all segments together constituting the desired digit. For example, the digit 3&#34; would be formed by applying voltage to input lines a, b, c, d, g. The signals on lines a-g are thus signals in an n out of seven&#34; code.  
  Since an n out of seven code is often inconvenient to the user, commercial indicator units are available which have a decoder associated with each seven segment indicator to convert a readily available code such as a binarycoded decimal code, into an n out of seven code. Such decoders are numbered 101A to 104A in FIG. 10. The complete indicator units, comprising indicators such as indicator 101 with an associated decoder 101A, are commercially available as integrated circuit units 5082-7,000, manufactured by Hewlett Packard. Alternatively. indicators and decoders can be purchased as separate units, indicators numbered 5082-7731 being compatible with decoders 9370.  
  Switch SW, of FIG. 10 represents a latch in the commercially available units which may be energized to short-circuit an indicator briefly to avoid flicker during transitions from one number to the next. Neither the above-described indicator units nor this latch consti tute a part of the present invention and are here described only to provide the background for facilitating the understanding of the latterv Also shown in FIG. 10 is a bank of switches 105, interconnected between a +5 volt source and the inputs to the decoders in such a manner that the determined potential of 5 volts is applied to a corresponding input upon closing of a switch. Unit 105 may thus be considered apparatus for furnishing the code signals for the known indicator units. The present invention is such apparatus. In particular, in a preferred embodiment of the invention, the code signals are in binary-coded decirnal form as will be discussed in detail with reference to FIG. 8.  
  Referring to FIG. 8, the binary codes of the present invention are so set that the numerals 0, l, 2 in the figure of tens of hour in the case of a 24 hour indicating device are indicated by the binary codes 00, 01 and 10, respectively, and the numerals 0, I, 2, 9 in the figure of ones of hour are indicated by the binary codes 0000, 0001, 0010,0011, 0100,0110, 1001. respectively. In like manner, the numerals 0, l, 2, 5 in the figure of tens of minute are indicated by the binary codes 000, 001, 010, 101, respectively, and the numerals 0, l, 2, 9 in the figure of ones of minute are indicated by the binary codes 0000, 0001, 0010, 001 l. 1001, respectively. The code is given by the non-contacting state of the Contact mounted on the contact mounting plate with the annular pattern formed on the printed pattern mounting plate while the code l is given by the contacting state of the contact with the pattern as described hereinafter.  
  Referring now to FIGv l, a motor 1 is connected to a minute shaft 2 so as to rotate the same by one revolution per 60 minutes. An intermittent driving mechanism 3 is connected to the minute shaft 2 so as to be driven thereby, and the intermittent driving mechanism 3 is connected to an hour shaft 4 so that the same is intermittently rotated by a given angle each time the minute shaft 2 rotates one revolution so as to be driven by one revolution per 24 hours.  
  A suitable intermittent driving mechanism is to be found in U.S. Pat. No. 3,456,123 (Pihl), FIGS. 2 and 3 and the corresponding description in columns 2-3. Specifically, activator 22 of Pihl is mounted on minute shaft 2 of FIG. I. The hour shaft of the present invention then corresponds to shaft 26 of rotor A, where notches 40 of rotor A are spaced to cause rotor A to complete l/24 of a revolution per revolution of actua tor 22.  
  Again referring to FIG. 1, an hour contact mounting plate 5 is secured to the hour shaft 4 and three contacts 6a, 6b and 6(- for determining the numeral in the figure of tens of hour are mounted on one side 5a of the plate 5 and electrically connected to each other while five contacts 7a, 7b 7e for determining the numeral in the figure of ones of hour are mounted on the other side 5b of the plate 5 and electrically connected to each other.  
  A minute contact mounting plate 8 is secured to the minute shaft 2 and four contacts 9a, 9b 9d for de termining the numeral in the figure of tens of minute are mounted on one side 8a of the plate 8 and electrically connected to each other while five contacts 10a, 10b l0e for determining the numeral in the figure of ones of minute are mounted on the other side 8b of the plate 8 and electrically connected to each other. The electrical connection of the contacts to each other may be achieved by using printed short-circuiting pattern 11 formed on the contact mounting plate as shown in FIG. 7, for example.  
  A first stationary printed hour pattern mounting plate 12 is supported on the stationary structure of the device represented only by the housing of the motor I, and coaxial with the hour contact mounting plate 5 so as to face against the side 5a of the plate 5 so that the contacts 6a. 6b. 6c slidably contact with the side of the plate 12.  
  Before the patterns on the minute and hour pattern mounting plates are discussed in detail, reference should be made to FIGS. 6 and 7. An example of the actual arrangement of the contacts with respect to the respective patterns is shown in FIGS. 6, 7 in which the contacts 70, 7e of the hour contact mounting plate 5 are shown cooperating with the patterns 17, 18, 21 of the hour pattern mounting plate 16.  
  Lead wires 33, 34, 37 are connected to the patterns 17, 18, 21, respectively. The lead wire 33 leading to the pattern 17 constitutes means for applying a determined potential to the primary conducting portion, the primary conductiong portion covering 360 being annulus 17. Lead-out conductors 34-37 are connected to patterns 18-21 respectively. Since contacts 7a-7e are all at the same potential (see FIG. 7) and contact 7a is always directly in electrical contact with annulus 17, all contacts carry a 5 volt potential. This 5 volt potential is transferred to a lead-out conductor whenever one of contacts 7b-7e makes electrical contact with a projection (annular segmental conducting portion) of its associated annulus. Separate switching circuits 33-34, 33-35, 33-36 and 33-37 using contacts -72 as activators (see unit 105, FIG. 10) are thus created. In order to prevent the mutual interference with the other switching circuits, diodes 38, 39, 41 are provided in the respective switching circuits 33-34, 33-35, 33-37 in the forward direction.  
  The hour and minute patterns will now be discussed in detail. Referring first to FIG. 2, three annular printed hour patterns 13, 14, 15 for cooperating with the contacts 6a, 6b, 66, respectively, are formed on the side of the plate l2 facing to the plate 5. The pattern 13 is in the annular form contacting at all times with the contact 6a, while the pattern 14 has a projecting portion so that the contact 6b is brought to contacting state only when the projecting portion 140 contacts with the Contact 6b during the rotation of the plate 5 corresponding to the code 1 in the first row of the figure of tens of hour in FIG. 8, while, when the contact 6b is in non-contacting state with the pattern 14, the code 0 is given in the first row. The projecting portion 14a has an angular range of 60 beginning at 300 and ending at 360 as measured in the anticlockwise direction from the top 0 in FIG. 2.  
  In like manner, the pattern 15 has a projecting portion in the range of l50-300 so as to bring the cooperating contact 6(&#39; in contacting state corresponding to the code l in the second row in the figure of tens of hour in FIG. 8. When the contact 60 is in noncontacting state in the remaining range of angle of rotation of the plate 5, i.e., the range of 300150, the code 0&#34; is given in the second row.  
  The binary code 00&#34; determines the numeral 0&#34; in the figure of tens of hour and the binary code 01 determines the numeral 1&#34;, while the binary code 10&#34; determines the numeral 2&#34; in the figure of tens of hour.  
  A second stationary printed hour pattern mounting plate 16 is stationarily supported coaxially with the hour contact mounting plate 5 so as to face against the side 5b of the plate 5 so that the contacts 70, 7b, 7e slidingly contact with the plate 16.  
  As shown in FIG. 3, five printed annular hour patterns l7, l8, 21 cooperating with the contacts 70, 7b, 7e, respectively, formed on the side of the plate 16 facing to the plate 5. The pattern 17 is in the annular form contacting at all times with the contact 70. The pattern 18 has two projections 18a, 18b so that the contact 7b is brought to contacting state to give the code l in the first row corresponding to the numerals &#34;8&#34; and 9&#34; in the figure of ones of hour when the projecting portions 18a, 18b contact with the contact 7b, while, when the contact 7b is in the non-contacting state, the code 0&#34; in the first row is given correspondingly to the numerals 0&#34;, I, 7&#34; in the figure of ones of hour.  
  To this end, the projecting portions 18a, 18b are located in the range of l20-l50 and the range of 270-300.  
  In like manner, the pattern 19 has two projecting portions 190, 19b so that the code 1&#34; is given in the second row correspondingly to the numerals 4&#34; to 7 in the figure of ones of hour when the projecting portions 19a, 18b contact with the contact 70, while, when the contact 71 is in non-contacting state, the code is given in the second row correspondingly to the numerals 0&#34; to 3&#34;, 8 and 9&#34; in the figure of ones of hour. To this end, the projecting portions 190, 1% are located in the range of 60-l20 and the range of 210270.  
  In like manner, the pattern 20 has five projecting portions 20a, 20b, 20e in the ranges of 30-60, 90-120, 180-210, 240-270, and 330-360, so that, when the contact 7d contacts with the projecting portions 20a, 20b, 20e, the code l is given in the third row correspondingly to the numerals 2&#34;, 3&#34;, 6&#34;, 7&#34; in the figure of ones of hour, while, when the contact 7d is in non-contacting state, the code O is given in the third row correspondingly to the numerals &#34;0&#34;, 1&#34;, 4&#34;, 8&#34;, 9 in the figure of ones of hour.  
  The pattern 21 has twelve projecting portions 21a, 21b, 211 in the range of and spaced by the angle of 15 from each other beginning at the projecting portion 210 located in the range of l5-30. Thus, when the contact 7e is in the contacting state with the projecting portions 210, 21b, 21!, the code l is given in the fourth row correspondingly to the numerals 1&#34;, 3&#34;, 5&#34;, 7&#34; and 9&#34; in the figure of ones of hour, while, when the contact 7e is in non-contacting state, the code &#34;0&#34; is given in the fourth row correspondingly to the numerals 0, 2, 4&#34;, 6&#34; and 8&#34; in the figure of ones of hour.  
  A first stationary printed minute pattern mounting plate 22 is stationarily supported coaxially with the minute contact mounting plate 8 so that the contacts 90, 9b 9d of the plate 8 slidably contact with the side of the plate 22. Four annular printed patterns 23, 24, 26 are formed on the side of the plate 22 facing against the plate 8 so that the contacts 90. 9b 9d contact with the patterns 23, 24 26, respectively. The pattern 23 is so shaped that it contacts with the contact 9a at all times. The pattern 24 has a projecting portion 24a in the range of 240-360 as shown in FIG. 4 so that, when the projecting portion 24 contacts with the contact 9b to bring it in contacting state, the code l&#34; is given in the first row of the figure of tens of minute in FIG. 8 correspondingly to the numerals 4&#34;, 5&#34; in the figure of tens of minute, while, when the contact 9b is in non-contacting state, the code 0&#34; is given in the first row correspondingly to the numerals 0 to 3&#34; in the figure of tens of minute.  
  The pattern 25 has a projecting portion 250 in the range of 120-240, so that, when the contact 9c contacts with the projecting portion 250 to bring it in contacting state, the code 1&#34; is given in the second row of the figure of tens of minute in FIG. 8 correspondingly to the numerals &#34;2, 3&#34; in the figure of tens of minute, while, when the contact 9c is in noncontacting state, the code 0&#34; is given in the second row correspondingly to the numerals 0&#34;, l, 4, 5&#34; in the figure of tens of minute.  
  The pattern 26 has three projecting portions 260, 26b and 26c each having the angular range of 60 and spaced by the angle of 60 from each other with the projecting portion 260 located in the range of 60l as shown in FIG. 4. Thus, when the contact 9d is in contacting state, the code l is given in the third row of the figure of tens of minute correspondingly to the numerals 1&#34;, 3&#34;, 5&#34; in the figure of tens of minute.  
  In like manner, a second stationary printed minute pattern mounting plate 27 is stationarily supported coaxially with the minute contact mounting plate 8 so that the contacts 10a, 10b slidably contact with the plate 27. As shown in H6. 5, five annular patterns 28, 29, 32 are formed on the side of the plate 27 so as to contact with the contacts 100, 10b, 102, respectively. The pattern 28 contacts with the contact at all times. The pattern 29 has six projecting portions 29a, 29b, 29] each having the angular range of 12 and angularly spaced by the angle of 48 from each other with the projecting portion 290 positioned in the range of 4860. Thus, when the contact 10b is in contacting state with the projecting portions 290, 2%, 29f, the code l is given in the first row of the figure of ones of minute corresponding to the numerals 8&#34;, 9&#34; in the figure of ones of minute as shown in FIG, 8, while, when the contact 10b is in non-contacting state, the code 0&#34; is given in the first row correspondingly to the numerals 0 to The pattern 30 has six projecting portions 300, 3012 30feach having the angular range of 24 and angularly spaced by the angle of 36 from each other with the projecting portion 300 located in the range of 24-48 as shown in FIG. 5. Thus, when the contact 10(- is in contacting state, the code l is given in the second row of figure of ones of minute correspondingly to the numerals 4&#34;, 5, 6&#34;, 7&#34;, while, when the contact 10c is in non-contacting state, the code 0&#34; is given in the second row correspondingly to the numerals 0 to 3&#34;, 8, 9&#34;.  
  In like manner, the pattern 31 has projecting portions 310-1, 310-2, 3lb-l, 3lb-2, 3lf-l, 3lf-2 located in 336-348, respectively. Thus, when the contact 10d contacts with the projecting portions 310-1, 310-2, 3 lf-l, 31f-2, the code &#34;1 is given in the third row of the figure of ones of minute correspondingly to the numerals 2&#34;, 3&#34;, 6, 7&#34; in the figure of ones of minute, while, when the contact 10d is in non-contacting state, the code 0&#34; is given in the third row correspondingly to the numerals 0&#34;, 1&#34;, 4&#34;, 5,  
  The pattern 32 has projecting portions 320-1, 320-2, 32a-3, 320-4, 3242-5, 32b-l, 32b-2, 32b-5, 32f-l, 32f-2, 32f-5 each having the angular range of 6 and spaced by the angle of 6 from each other with the projecting portion 320-1 located in the angular range of 6l2 as shown in H0. 5. Thus, when the contact 102 is in contacting state with the projecting portions of the pattern 32, the code 1&#34; is given in the fourth row of the figure of ones of minute correspondingly to the numerals 1&#34;, &#34;3&#34;, 5&#34;, 7&#34;, 9&#34; in the figure of ones of minute, while, when the contact We is in noncontacting state, the code &#34;0 is given in the fourth row correspondingly to the numerals 0&#34;, 2&#34;, 4&#34; &#34;6, 8&#34; in the figure of ones of minute.  
  Since the plate 5 is rotated by the hour shaft 4 in the direction indicated by the arrow intermittently every 60 minutes so as to rotate by one revolution per 24 hours, the numeral in the figure of ones of hour is changed every minutes so as to correctly indicate the time in terms of hour.  
  In like manner, the numeral in the figure of tens of hour is changed every [0 hours so as to correctly indicate the time in terms of tens of hour by means of the switching circuits formed by the contacts 6a, 6b and 6c.  
  Since the minute shaft 2 is rotated a revolution per 60 minutes, the time is correctly indicated in terms of minute by means of the switching circuits formed by the contacts 90, 9b, 9d and the contacts 100, I01).  
  FIG. 1 shows the condition of the device in which all the contacts are in non-contacting conditions so that all the switching circuits are kept in opened states. Thus, as shown in FIGS. 8 and 9, the binary codes generate the pulses indicating 00 hour (o&#39;clock) 00 minutes.  
  The minute shaft 2 is rotated by 6 with the lapse of one minute so that the contacts 90, 9b, 9d and the contacts 10a, 10b, 101 are rotated by 6. Therefore, the contact We is brought to contacting state with the projecting portion 32u-l, while the remaining contacts are kept in non-contacting states so that the time pulse is generated so as to indicate ()0 hour 01 minute. In like manner, the indication of the time is changed in every 1 minute.  
  For example. the time ()5 hours 21 minutes is indicated when the combination of the contacting and noncontacting states of the contacts are achieved in which the contacts 612, 61&#39;, 7b, 7d, 9b, 9d, b, 10c, 10d are in non-contacting states with the respective cooperating patterns while the contact 70 contacts with the projecting portion 190 of the pattern l9, the contact 7e contacting with the projecting portion Zle of the pattern 2i, the contact 9c contacting with the projecting portion 25a of the pattern 25, the contact IOe contacting with projecting portion 32c-l of the pattern 32.  
  In like manner. the time l5 hours 46 minutes is indicated by the non-contacting states of the contacts 6b, 7b, 7d, 9c, 9d, 10b, l0e and the contacting states of the contacts 6c, 7c, 70, 9b, 10c. 10d with the projecting portions a, 19b, Zlb, 240, 30c, 3le-2, respectively.  
  The time 23 hours 59 minutes is indicated by the non-contacting states of the contacts 66, 7b, 70, 9c, 10c, 10d and the contacting states of the contacts 6b, 7d, 7e, 9b, 9d, 10b, ltle with the projecting portions 14a, 20c, 21]. 2401, 26c, 29f, 32f-5, respectively.  
  The above described device is constructed for indicating 24 hours, But. if the indication of 12 hours is desired, the pattern I5 is dispensed with, because the numeral in the figure of tens of hour is either 0&#39; or l not including 2, and the patterns formed on the printed hour pattern mounting plate 16 are angularly magnified so that the range of 180 is extended to 360, while the hour shaft 4 is rotated one revolution per l2 hours.  
  In the above described embodiment, the indication of 00 hour 00 minute is given. However, if the indication of 24 hours 00 minute or 12 hours 00 minute is desired in place of the above 00 hour 00 minute, the configuration of the patterns determining the numerals in the figure of tens of hour and in the figure of ones of hour may be modified slightly.  
  Although the contacts on the same side of the respective contact mounting plates are shown as being arranged in a straight line, any of the contacts may be located in angularly shifted position insofar as the cooperating pattern is angularly shifted by the same angle.  
  In the above embodiment. a single hour contact mounting plate mounting the contacts on both sides thereof and a single minute contact mounting plate mounting the contacts on both sides thereof are used while a pair of printed hour pattern mounting plates and a pair of printed minute pattern mounting plates are provided so as to cooperate with the hour and minute contact mounting plates, respectively. However, a pair of hour contact mounting plates each mounting the contacts on one side thereof and a pair of minute contact mounting plates each mounting the contacts on one side thereof may be provided.  
  In this case, the pair of printed hour pattern mounting plates and the pair of printed minute pattern mounting plates may be replaced by a single hour pattern mounting plate mounting the patterns on both sides thereof and interposed between the pair of hour contact mounting plates for cooperating with the contacts thereof and a single minute pattern mounting plate mounting the patterns on both sides thereof and interposed between the pair of minute contact mounting plates for cooperating with the contacts thereof, respectively.  
  Further, the printed hour and minute pattern mounting plates may be rotated together with the hour and minute shafts, respectively. while the hour and minute contact mounting plates are kept stationary.  
  In this case, the patterns on the respective sides of the hour and minute pattern mounting plates are shortcircuited while lead wires are connected to the respective cooperating contacts.  
  The above described embodiment of the present invention makes it possible to construct the device in a compact size and simple in construction at a low cost without requiring any complicated adjustments.  
 What is claimed is:  
  I. In a clock furnishing a digital indication of time and having at least 1 minute and 1 hour indicator units, each having a plurality of inputs, each for furnishing a visual output signal signifying a corresponding digit upon application of a code signal corresponding to said digit to said plurality of inputs; apparatus for furnishing said code signal, comprising, in combination, a minute shaft; means for rotating said minute shaft a predetermined number of revolutions per hour; an hour shaft; means for rotating said hour shaft a predetermined angle per every hour; at least one minute contact plate and one hour contact plate, each having a plurality of conducting contact portions separated from each other by predetermined distances in the radial direction; at least 1 minute pattern mounting plate associated with said minute contact plate; at least 1 hour pattern mounting plate associated with said hour contact plate, each of said pattern mounting plates having annular segmental conducting portions spaced from each other in a radial direction at distances corresponding to said predetermined distances separating the corresponding ones of said contacts, said annular segmental conducting portions including a primary portion covering 360, each contact plate and an associated pattern mounting plate being mounted in operative proximity for relative rotation, said hour contact plate and the associated hour pattern mounting plate constituting a pair of associated hour plates, said minute contact plate and the associated minute pattern mounting plate constituting a pair of associated minute plates, one of said hour plates and one of said minute plates being mounted on said hour shaft and on said minute shaft respectively, each of said pairs consisting of an active plate and of a control plate; means for applying a predetermined potential to a selected one of said conducting portions of said active hour plate and of said minute plate, said selected conducting portion being said primary portion when said active plate is said pattern mounting plate; a plurality of minute and hour lead-out conductors, connected to each of the remaining conducting portions of said active minute and hour plates respectively; conducting means for forming substantially zero resistance connections among all of said conducting portions of each of said control plates, whereby rotation of said hour shaft and said minute shaft causes, respec tively, each of said hour and minute lead-out conductors to be alternately connected to and disconnected from said predetermined potential, in accordance with the pattern, respectively, of said hour and minute pattern mounting plates, the signals on said hour and minute lead-out conductors constituting, respectively, said code signals for energizing said hour and minute indicator units.  
  2. Apparatus as set forth in claim I, wherein said control plates are the rotating ones of said plates and said active plates are stationary.  
  3. Apparatus as set forth in claim 2, wherein said active plates are said minute and hour pattern mounting plates and wherein said control plates are said minute and hour contact plates.  
  4. Apparatus as set forth in claim 3, wherein said plurality of indicator units comprises a first and second indicator unit for indicating, respectively, tens and ones of hours, and a third and fourth indicator unit for indicating, respectively, tens and ones of minutes; wherein said minute and hour contact plates each have a first and second side; wherein said contacts comprise a first and second plurality of minute and hour contacts respectively, mounted on each of said first and second sides of said minute and hour contact plates respectively; wherein said at least one minute pattern mounting plate comprises a first and second minute pattern mounting plate mounted, respectively, opposite said first and second side of said minute contact plate, each of said minute pattern mounting plates having said annular segmental conducting portions on the side facing said minute contact plate; wherein said at least one hour pattern mounting plate comprises a first and second hour pattern mounting plate mounted, respectively, opposite said first and second side of said hour contact plate, said first and second hour pattern mounting plates having said annular segmental conducting portions on the sides facing said hour contact plate; and wherein said plurality of lead-out conductors comprises a first plurality of lead-out conductors connected to said first hour pattern mounting plate for furnishing said code signals for said first indicator unit, a second plurality of lead-out conductors connected to said second hour pattern mounting plate for furnishing said code signals to said second indicator unit, a third plurality of lead-out conductors connected to said first minute pattern mounting plate for furnishing said code signals for said third indicator unit, and a fourth plurality of lead-out conductors connected to said second minute pattern mounting plate for furnishing said code signals for said fourth indicator unit.  
  5. Apparatus as set forth in claim 4, wherein said contact plates and said pattern mounting plates cooperate in such a manner that said first, second, third and fourth plurality of lead-out conductors each carry sig nals coded in a binary coded decimal code.  
  6. Apparatus as set forth in claim 5, wherein each of said indicator units comprises a seven segment indicator adapted to receive code signals in an n out of seven code and a code converter for receiving said binary coded decimal signals and converting same to said n out of seven code.  
  7. Apparatus as setforth in claim 1, wherein said digital indication is from gero to 24 hours; wherein said means for rotating said minute shaft comprise means for rotating said minute shaft one revolution per hour; and wherein said means for rotating said hour shaft comprise means for rotating said hour shaft an angle of 15 once every hour.  
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