Abstract:
A leaf-type clock driven by a intermittent and segmental rotation by using so called Geneva-gear mechanism to cause turning-over of the time- and minute-indicating leaves is disclosed. This leaf-type clock has the advantages that number of the leaves may be reduced, and that the time accuracy is improved, and further that small-sized clock can be designed.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates to a so-called leaf-type digital clock (e.g. in U.S. Pat. No. 3,220,174) in which a plurality of tilting leaf-plates carrying figures and the like are hinged on the peripheries of horizontally oriented frames and shown in individually separated windows on the front surface of the clock. 
     In the leaf-type clock, there are advantages that the figures and letters to be indicated can be made much larger in comparison with those of the other kinds of digital-type clocks, in which hours, minutes and the like are marked on the cylindrical surface of drums, and further that even continuous sixty figures of minutes or thirty-one figures of dates can be indicated with only one rotary frame. 
     On the other hand, in such leaf-type clock, a great many sheets of leaves are needed for hour- and minute-indications in total, that is, 108 sheets of leaves at least. Then, when the minute indicating leaf is so constructed as it is divided into two kinds of parts, that is, ten-minute indicating leaf and one-minute indicating leaf while providing an AM-PM indicating mean thereto, it is estimated that only 34 sheets of leaves in total will serve for hour- and minute-indications. However, when such a division of minute-indicating leaf as above is applied to the conventional leaf-type clock which has been driven by gear train with uniform rotation, there will be caused a fatal disadvantage that it takes many minutes, after a leaf has been turned over, to make the next leaf vertical to observer&#39;s eye, for example, it takes 60 seconds for a one-minute indicating leaf, 10 minutes for a 10-minute indicating leaf and 60 minutes for an hour indicating leaf. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to such a leaf-type clock as it is driven by a intermittent and segmental rotation by using so-called Geneva-gear mechanism instead of the uniform rotation of the driving gear train in the conventional leaf-type clock so as to cause turning-over of the indicating leaves. 
     According to the invention, by reason that it is possible to make the rotary angle of a intermittent and segmental rotation caused by the engagement of the relevant Geneva-gears large, and the time required for such a rotation short, such dividing of the minute indicating leaf into 10-minute indicating and 1-minute indicating leaves may be accomplished, resulting in reduction of the number of leaves to 34 sheets. In the leaf-type clock of the invention, the time in which the succeeding leaf, after a leaf has been turned over, become vertical to observer&#39;s eyes, is markedly reduced in comparison with those in the conventional leaf-type clocks (e.g. in the embodiment of the invention hereinafter it is 6 seconds for every kind of leaves). Such reduction of the number of leaves in the leaf-type clocks makes necessarily possible to make the rotary frames carrying the leaves small and further to make the clock itself small-sized. 
     Furthermore, according to the leaf-type clock of the invention, the time accuracy of the alarm mechanism is improved significantly. In the conventional leaf-type clocks, the operation of such mechanism is also caused by the uniform rotary motion of the driving gear train, so that minor deviations of the size and framework of the relevant parts affected the time accuracy of this mechanism directly. In contrast, in the present invention, since it can make the rotary angle of a intermittent and segmental rotation, as mentioned previously, large and make the time of such a rotation short, the error of the time of the alarm mechanism in the conventional leaf-type clocks as above-mentioned may be almost eliminated. 
     An object of the invention, accordingly, is to provide a leaf-type clock with reduced number of the indicating leaves. 
     Another object of the invention is to provide a small sized leaf-type clock in comparison with the customary ones. 
     Further object of the invention is to provide a leaf-type clock having alarm mechanism the time accuracy of which is markedly improved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Still further objects of the invention will be understood from the detailed explanation of the invention in reference to the accompanying drawings in which: 
     FIG. 1 is a fragmental front view of an embodiment of the invention; 
     FIG. 2 is a disassembled oblique view of the one-minute wheel composition of the same embodiment; 
     FIG. 3 is a disassembled oblique view of the ten-minute wheel composition and hour wheel composition of the same embodiment; 
     FIG. 4 is a disassembled oblique view of the alarm mechanism of the same embodiment; 
     FIG. 5 is a left side view of the one-minute unit frame of the embodiment; 
     FIG. 6 is a left side view of the ten-minute unit frame of the embodiment; 
     FIG. 7 is a left side view of the hour unit frame of the embodiment; 
     FIGS. 8 and 9 are enlarged sections illustrating the ratchet mechanism between the one-minute wheel and one-minute unit frame, but not showing the indicating leaves. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in particular to FIGS. 1, 2 and 3, the uniform rotary motion of a synchronous motor (not shown) is reduced and conveyed to the 2nd wheel (time) 1 so as to rotate the same uniformly, once per minute. The 2nd wheel 1 has the Geneva-gear part 1a (having one tooth) and the disc part 1b both of which are adjacent to each other. The 1-minute wheel 2 is mounted loosely on the shaft 5, and has the Geneva-gear part 2a (having 10 teeth) which engages intermittently with said Geneva-gear part 1a of the 2nd wheel 1 and has the adjacent star wheel part 2c which contacts with the circumference of said disc part 1b of the 2nd wheel 1 so as to check free rotation of the 1-minute wheel 2, thereby the 1-minute wheel 2 rotates by 36°, once per minute and a full rotation of it is completed in 10 minutes. One-minute unit frames 3 and 3 of one body are connected to the  1-minute wheel 2 through a ratchet mechanism and mounted rigidly on the shaft 5, and on the peripheries of this frames 3, 3 are loosely hinged ten sheets of 1-minute indicating leaves 4, 4, ...... carrying figures &#34;0&#34;, &#34;1&#34;, . . . &#34;9&#34;, respectively (cf. FIG. 5). Said frames 3, 3 segmentally rotate, therefore, together with the wheel 2, and the leaves 4, 4 . . . are turned over one by one at intervals of one minute. Said ratchet mechanism is so composed as the points of a pair of jumper springs 2e, 2e which are secured to the left side of the wheel 2 are engaged with two corresponding teeth of the ratchet gear 3f which is secured to the right side of the frame 3 (cf. FIG. 8), so as to be able to correct the indicating time of the clock manually. That is, in FIG. 8, when the shaft 5 secured to the frames 3, 3 is caused to rotate counterclockwise by a hand setter (not shown), the points of said jumper springs 2e, 2e are released from the relevant teeth of the ratchet gear 3f and engage with subsequent corresponding teeth of the wheel 3f, resulting in manual turning-over of the leaves 4 on the frames 3, 3, while the wheel 2 together with the jumper springs 2e, 2e is being driven by the motor. 
     To said shaft 5 is secured a 1-minute median wheel 6 a full rotation of which is completed in ten minutes together with the wheel 2 and which has the Geneva-gear part 6a (one tooth) and the disc part 6b. Further, a 10-minute median wheel 7 is mounted on an appropriate shaft and consists of the Geneva-gear part 7a (eight teeth) which engages intermittently with the Geneva-gear 6a of said wheel 6, the star wheel part 7c which contacts with the circumference of the disc part 6b of said wheel 6 so as to check the free rotation of this wheel 7, and the gear part 7d, thereby this wheel 7 rotates by 45°, once per 10 minutes and a full rotation of it is completed in 80 minutes. A 10 minute wheel 8 is secured to the shaft 9, in which the shaft 5 is telescoped, and consists of the Geneva-gear part 8a (two teeth), the disc part 8b, and the gear part 8d meshing with the gear part 7b of said wheel 7 in the ratio of tooth number 3 : 2, thereby this wheel 8 rotates by 30°, once per ten minutes and a full rotation of it is completed in 120 minutes. To the shaft 9 are secured ten-minute unit frames 10, 10, and on the peripheries on the frames 10, 10 are loosely hinged twelve sheets of ten-minute indicating leaves 11, 11, . . . carrying figures &#34;0&#34;, &#34;1&#34;. . . &#34;6&#34;, &#34;0&#34;, &#34;1&#34;, . . . &#34;6&#34;, respectively, whereby such leaves 11, 11, . . . are turned over one by one with the rotation of the frames 10, 10 (cf. FIG. 6), at intervals of 10 minutes. 
     On the other hand, an hour median wheel 12 is mounted on an appropriate shaft and consists of the Geneva-gear part 12a (six teeth) which engages intermittently with the Geneva-gear part 8a (two teeth) of said wheel 8, the star wheel part 12c which contacts with the disc part 8b of said wheel 8 so as to check the free rotation of this wheel 12, and the gear part 12d, thereby this wheel 12 rotates by 60°, once per an hour and a full rotation of it is completed in 6 hours. Further, an hour wheel 13 is mounted loosely on the shaft 9 and has the gear part 13d which meshes with the gear part 12d of said wheel 12 in the ratio of tooth number 2 : 1, thereby this wheel 13 rotates by 30°, once per an hour and a full rotation of it is completed in twelve hours. To said wheel 13 are secured hour unit frames 14, 14, and on the peripheries of this frames 14, 14 are hinged 12 sheets of hour indicating leaves 15, 15, . . . carrying figures &#34;1&#34;, &#34;2&#34;, . . . &#34;12&#34;, respectively, whereby such leaves 15, 15, . . . are turned over in order with the rotation of the frames 14, 14 (cf. FIG. 7), at intervals of one hour. 
     The upper end of each of the one-minute indicating, ten-minute indicating and hour indicating leaves, 4, 4, . . . , 11, 11, . . . , 15, 15, . . . is slightly caught by the lower edge of the beam 22 installed on the upper part of the frontage of the clock, and thereby the spontaneous falling of the leaf due to the gravity is prevented during the time from the instant of its having come to vertical position up to the instant of its beginning to fall by the next intermittent and segmental rotation. 
     On the hour wheel 13, there is also a small gear part 13d&#39;, which meshes with the gear part 16d of a AM-PM indicating cam 16 in the ratio of tooth number 2 : 1, and thereby a full rotation of the cam 16 is completed in 24 hours, resulting in indication of letters &#34;AM&#34; (ante meridiem) or &#34;PM&#34; (past meridiem) of the AM-PM indicating lever 17 by intermittent contact of the cam 16 with the lever 17. 
     Furthermore, to the 10-minute median wheel 7 is secured an idle gear 18, a full rotation of which is completed in 80 minutes together with said wheel 7, and which is so constructed as it is connected with the alarm gear 20 through the alarm median gear 19, so as to complete a full rotation of the gear 2 in 24 hours resulting in joining of the gear 20 with the alarm dial 21 at the predetermined time and in operation of the alarm bell or the like (cf. FIG. 4). 
     In the aforementioned embodiment of the invention, were arranged 10 sheets of the 1-minute indicating leaves 4, 4, . . . , however, it may generally by any multiple of 10, that is, 10, 20, 30, . . . 10m. Such leaves 4, 4, . . . may be so arranged as the successive numerals of them are repeated as &#34;0&#34;, . . . &#34;9&#34;, &#34;0&#34;, . . . &#34;9&#34;, . . . , while the 1-minute wheel 2 being so designed as it segmentally rotates once per minute constantly and a full rotation of it is completed in 10, 20, . . . 10m minutes, respectively (&#34;m&#34;is a positive integer), Likewise, in the embodiment, 12 sheets of the 10-minute indicating leaves 11, 11, . . . were arranged, which number might however be any multiple of 6, that is, 6, 12, . . . 6n. The leaves 11, 11, . . . may be so arranged as their successive numerals are repeated as &#34;0&#34;, . . . &#34;5&#34;, &#34;0&#34;, . . . &#34;5&#34;, . . . , while the 10-minute wheel 8 being so designed as it segmentally rotates once per ten minutes constantly and a full rotation of it is completed in 1, 2, . . . n hour(s), respectively (&#34;n&#34;is a positive integer). 
     Furthermore, the number of hour indicating leaves 15, 15, . . . may be any multiple of 12, that is, 12, 24, 36, . . . 12p, and the leaves 15, 15, . . . may be so arranged as their successive numerals are repeated as &#34;1&#34;, . . . &#34;12&#34;, &#34;1&#34;, . . . &#34;12&#34;, . . ., while the hour wheel 13 being so designed as it segmentally rotates once per hour constantly and a full rotation of it is completed in 12, 24, . . . 12p hours, respectively (&#34;p&#34; is a positive integer). 
     On the other hand, said one-minute indicating leaves 4, 4, . . . may be, for the number thereof being 20, 30, . . . 10m sheets, so arranged as the same numerals of them are repeated as &#34;0&#34;, &#34;0&#34;, . . ., &#34;1&#34;, &#34;1&#34;, , . . ., while the 1-minute wheel 2 being so designed as it segmentally rotates once per 1/2, 1/3, . . . 1/m minute, respectively, and a full rotation of it is completed constantly in 10 minutes. Likewise, the 10-minute indicating leaves 11, 11, . . . may be so arranged as the same numerals of them are repeated as &#34;0&#34;, &#34;0&#34;. . ., &#34;1&#34;, &#34;1&#34;, . . ., while the 10-minute wheel 8 being so designed as it segmentally rotates once per 10/1, 10/2, . . . 10/n minutes, respectively, and a full rotation of it is completed constantly in an hour. Moreover, the hour indicating leaves 15, 15 . . . may be so arranged as the same numerals of them are repeated as &#34;1&#34;, &#34;1&#34;, . . ., &#34;2&#34;, &#34;2&#34;, . . . while the hour wheels 13 is so designed as it segmentally rotates once per 1/2, 1/3, . . . 1/p hour, respectively, and a full rotation of it is completed constantly in 12 hours. 
     In the present invention, it is preferable to make the sheet numbers of the three kinds of indicating leaves, i.e., the 1-minute indicating, 10-minute indicating and hour indicating leaves as approximate to each other as possible. For example, it is most suitable to adopt 30 sheets of the 1-minute indicating leaves, 24 sheets of the 10-minute indicating leaves and 24 sheets of the hour indicating leaves. In order to indicate the AM-PM, it may also adopt such a way as the letters &#34;AM&#34; or &#34;PM&#34; are directly illustrated in the upper corner of the corresponding hour indicating leaves 15, 15, . . . , respectively. The number of the jumper springs 2e, 2e in the above embodiment may be increased if necessary. 
     Further, in the present invention, in order to check the free rotation of the subordinate wheels (i.e., the one-minute wheel 2, 10-minute median wheel 7 and hour median wheel 12) in the Geneva-engagements, it may be applied thereto other known means, which have been generally employed in the Geneva-engagement, instead of such contacts of the star wheels part 2c, 7c and 12c with the respective disc parts of the preceding wheels (i.e., the 2nd wheel 1, 1-minute median wheel 6 and 10-minute wheel 8), as explained in the above embodiment.