Abstract:
First and second detecting wheels, the phases of which can be varied in accordance with the setting of an alarm signaling time, are provided in correspondence to an hour time wheel and a minute time wheel respectively. Among a plurality of leaves adapted for digitally indicating the minute time, some of the leaves, which occur at a constant interval of minutes, are each provided with a projection, and a third detecting means is provided to detect the presence or absence of this projection. An alarm device is actuated when the first and second detecting wheels and third detecting means are concurrently actuated.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to time a detecting device for a leaf type digital clock and, more particularly, to improvements in or relating to the invention disclosed in Japanese patent application No. 107528/1977 filed by the same applicant. 
     The above Japanese patent application No. 107528/1977 discloses an alarm device, which is actuated when a first signal produced by a signaling time detection plate provided in correspondence to an hour wheel and a second signal produced by a second detecting means cooperating with a projection of one of a plurality of minute leaves occur simultaneously. The disclosed construction readily suggests the provision of two switches, respectively corresponding to the signaling time detection plate and second detecting means in the case when the former is disposed on the left side of hour leaves and the latter on the right side of minute leaves of a clock. Such a construction, however, requires an increased number of switches, and this is disadvantageous from the standpoints of economy and compactness. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of this invention is to solve the above drawback and fully realize the object of the invention disclosed in Japanese patent application No. 107528/1977 with simpler means. 
     According to the present invention, the aforementioned object is achieved by the provision of a first detecting lever cooperating with the signaling time detecting plate and a second detecting lever cooperating with the projections of minute leaves and capable of being driven by the first detecting lever, and permitting a switch which can operate the alarm device to be responsive to the second detecting lever. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of the main construction according to the invention; and 
     FIGS. 2 to 4 show some portions in the construction of FIG. 1. FIGS. 3a, 3b, and 4a, 4b show some portions in the construction of FIG. 1; FIG. 5 is a sectional view showing the main construction of a second embodiment; and FIGS. 6a-6d show a portion of the construction of FIG. 5. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, an embodiment illustrated in the appended drawings will be described below. First, the structure shown in FIGS. 1 and 2 will be described. 
     A signaling time indication mechanism will first be described. Designated at 1 is a driving motor, which is meshed with a minute wheel 2 for driving the same at a speed of one rotation per 60 minutes. The minute wheel 2 is coupled through a well-known ratchet mechanism to a minute leaf drum 3 for rotating the drum only in one direction. The minute leaf drum 3 is secured to a shaft 7. Its right hand end is journalled in a case 5, and it has 60 minute leaves. As shown in FIG. 2, these minute leaves include first minute leaves 6a having no projection, second minute leaves 6b each provided only on its left hand edge with a projection 60 (not shown), third minute leaves 6c each provided at the right hand edge with a projection 61 (not shown) and fourth minute leaves 6d each provided at both the left and right hand edges with respective projections 60 and 61 (not shown). Of these minute leaves, first minute leaves 6a are used when indicating &#34;00&#34; and &#34;01&#34;  minutes past a given hour, third minute leaves 6c are used when indicating &#34;02&#34;, &#34;03&#34; and &#34;04&#34; minutes past a given hour, first minute leaves 6a are again used when indicating &#34;05&#34; and &#34;06&#34; minutes past a given hour, and so on; two first minute leaves 6a and three third minute leaves 6c are combined and arranged as leaves for indicating up to &#34;44&#34; minutes past a given hour. 
     Second minute leaves 6d are used when indicating &#34;45&#34; and &#34;46&#34; minutes past a given hour, fourth minute leaves 6d are used when indicating &#34;47&#34;, &#34;48&#34; and &#34;49&#34; minutes past a given hour, and so on; two second minute leaves 6b and three fourth minute leaves 6d are combined and arranged for indicating up to &#34;59&#34; minutes past a given hour. 
     Designated at 8 is an hour leaf drum rotatably supported by a central shaft 7, and it has 48 hour leaves 9. 
     A second minute wheel 10 is fixedly secured to the shaft 7 at an intermediate portion thereof, and its boss 10a is rotatably supported by a minute indication drum 20 which will be described later. The second minute wheel 10 has cam holes 10b and a pinion 10c. The pinion 10c is geared through an intermediate hour wheel 11 to an hour wheel 8a provided on the hour leaf drum 8. 
     The above hour wheel 8a defines cam holes 8b in its left side face. 
     Designated at 13 is an hour leaf holding spring. When an hour leaf 9 is raised in an interlocked relation to the left hand projections 60 of the second and fourth minute leaves, the hour leaf 9 is held by the spring so that it will not be inverted even if it is released from a second pawl 14b of a feed spring 14, and it is inverted instantaneously with the release of the fourth minute leaf 6d indicating &#34;59&#34; minutes past a given hour from a first pawl 14a of the feed spring, at which time &#34;00&#34; minute past the next hour is indicated and also the hour leaf 9 is released from the spring 13. 
     Now, a signaling mechanism will be described. Designated at 15 is a signaling time setting knob, which is coupled to a minute indication drum 20 having 60-minute scale signaling time graduations provided at an interval of 5 minutes. One end of the minute indication drum 20 is rotatably supported by an intermediate plate 19 secured by screws 24 to the case 5 and the other of the same is rotatably supported by a side plate 18 fixedly secured to the intermediate member 19. An hour indication drum 21, which is fed by one pitch with one rotation of the minute indication drum 20 through a carry gear 17, is rotatably supported on a central boss of the minute indication drum 20. The minute indication drum 20 is provided in its intermediate portion with a click gear 20a, which engages with a click spring 19a projecting from the intermediate plate 19 and provides a click stop action at an interval of, for example, five minutes when the knob 15 is rotated. It is also provided adjacent to its right hand end with grooves 20c and ribs 20d between these grooves, as shown in FIGS. 3a and 3b and a minute detection plate 25 is coupled to the minute indication drum 20 such that it is not rotatable but is movably guided in the axial direction with respect to the minute indication drum. 
     The minute indication member 25 has cams 25a, which can be received in the afore-mentioned cam holes 10b formed in the second minute wheel. The minute indication drum 20 is further provided adjacent to its right hand end with a pinion 20b which is meshed with an intermediate wheel 22 which is in turn guided for rotation by a boss 19c projecting from the intermediate plate. The intermediate wheel 22 has a pinion 22a  which is rotatable with the shaft 7 and meshed with the gear of an hour detection plate 26, when guided in a movable fashion lengthwise relative to the shaft 7. 
     The hour detection member 26 has cams 26a, which can be received in the afore-mentioned cam holes 8b in the hour drum. 
     Now, a signaling time detecting mechanism shown in FIG. 2 will be described. Designated at 27 is a first detecting lever, which is rotatable about a pin 28 and has first and second arms 27a and 27b respectively adapted to cooperate with the afore-mentioned minute and hour detection plates 25 and 26 and also a pin 27c  to be described later. Designated at 29 is a second detecting lever, which is rotatable about a pin 30 and has a first arm 29a adapted to cooperate with the right hand projections of the third and fourth minute leaves 6c and 6d. Its other end is provided with a groove 29c which is in engagement with a pin 27c projecting from the first detecting lever. The first arm of the second detecting lever is provided at an intermediate portion with a projection 29b, which is adapted to cooperate with a first switch SW 1  to be described later. 
     A second switch SW 2  is a so-called alarm stopping switch, and it is closed when the user wants to use a buzzer B. The switches SW 1  and SW 2  as well as buzzer B are connected in series to a power supply E. 
     The operation of the above described structure will now be described. When the alarm signaling device is wanted to be used, the second switch SW 2  is first closed, and then the desired alarm time is set by turning the knob 15 while watching the figures inscribed in the minute and hour indication drums 20 and 21. At this time, if the cams 25a and 26a provided on the minute and hour detection plates 25 and 26 are arranged, as shown in FIG. 4a, to have a perpendicular profile on one side, the knob can be turned only in one direction. If the cams have a profile as shown in FIG. 4b, slanted on the opposite sides, the knob can be rotated in both forward and backward directions. 
     With the setting of the signaling time the alarm phases of the cams 25a and 26a of the minute and hour indication plates 25 and 26 are determined. When the clock is left in this state, the motor 1 rotates the minute wheel 2, minute leaf drum 3 and second minute wheel 10 and also rotates the hour leaf drum 8 through the intermediate hour wheel 11. 
     In the course of the above operation, the cam holes 8b of the hour leaf drum 8 and the cams 26a of the hour detection member 26 first come to coincidence, i.e. in phase with one another, so that the hour detection plate 26 is now capable of being moved in the rightward direction by the force of the first switch SW 1  through the first detecting lever 27. At this time, however, the cams 25a of the minute detection plate and the cam holes 10b of the second minute wheel are not yet brought into coincidence, i.e. in phase with one another, and thus the rotation of the first detecting lever 27 is not caused prevented. Thus, the first switch SW 1   still remains open. 
     With further rotation of the hour wheel the cams 25a of the minute detection plate 25 eventually come into phase with the cam holes 10b of the second minute wheel 10. At this time, the minute detection plate 25 is capable of being moved rightwards. However, the tip of the arm of the second detecting lever at this time cooperates with the right hand projection of the third or fourth minute leaf 6c or 6d  and is thus incapable of rotation as shown in FIG. 2, so that the first switch SW 1  remains &#34;off&#34;. Thus, the buzzer B is not operated yet. 
     When the leaf indicating &#34;59&#34; minutes past a given hour, as shown in FIG. 2, is inverted to &#34;00&#34;,  there is no longer any projection restricting the second detecting lever. As a result, the first and second detecting levers are rotated by the force of the first switch SW 1  to close the first switch SW 1 , whereby the buzzer B is operated. At this time, the operation of the buzzer B can be stopped by opening the second switch SW 2 . 
     If the buzzer B is left sounding without stopping it, after a lapse of a couple of minutes from the triggering of the buzzer B the second detecting lever is raised again by the projection of the third minute leaf 6c, and as a result the associated first switch SW 1  is opened to stop the buzzer B temporarily. After a further lapse of time, for example &#34;05&#34; minutes past the given hour, the projection again has moved away, thus causing a clockwise rotation of the second detecting lever to close the first switch SW 1  and cause the buzzer B to sound again. In this way, if the measure of stopping the buzzer sound is not taken, the buzzer B is repeatedly caused to sound for every five minutes until the cams 25a of the minute detection plate leave the cam holes 10b of the second minute wheel. 
     While in the above embodiment the first and second detecting levers 27 and 29 are coupled together by the engagement between pin 27c and groove 29c, it may also be feasible to construct them in such a way that the pin 27c of the first detecting lever 27 is adapted to follow the back side of the second detecting lever 29. Also, while in the above embodiment the first switch SW 1  is adapted to cooperate with the second detecting lever 29, similar effects may also be obtained by adapting the switch to cooperate with the first detecting lever (27). 
     A second embodiment shown in FIGS. 5 and 6a -6b will now be described. 
     This embodiment is different from the first embodiment in the hour leaf drum feed mechanism and alarm signaling time detection mechanism, and these different portions will be described. 
     In the alarm signaling time indicating mechanism, a minute leaf drum 103 having minute leaves 106a to 106d similar to those in the first embodiment is provided at the left hand end with an integral pinion 103a which meshes with an intermediate hour wheel 111. An hour leaf drum 108 is also provided at its right hand end with an hour hand wheel 108a meshing with a pinion 111a provided on the intermediate hour wheel 111. 
     Now, the alarm signaling time indicating mechanism will be described. Designated at 125 is a minute detection member which is integral with a minute indication drum 120 like the first embodiment. It has a first switch member 130 as shown in FIG. 6a, which is secured to the surface of the minute detection member 125. The first switch member 130 has a disc portion 130a which is always in contact with a slide contact piece 135 of a first switch SW 1  and a contact arm 130b extending rightwards through a hole formed in the minute detection member 125. 
     Designated at 110 is a second minute wheel secured to a shaft 107, and it has a second switch member 131 as shown in FIG. 6b, secured to its surface. The second switch member 131 has a disc portion 131a and a sector-shaped switch section 131b penetrating and extending parallel to the left hand side of the second minute hand wheel 110. The sector-shaped switch section 131b is capable of being brought into contact with the contact arm 130b of the first switch member. Designated at 126 is an hour detection member which is coupled through a second intermediate hour wheel (not shown) to a pinion 120b of the minute indication drum like the first embodiment, and it has a third switch member 132 as shown in FIG. 6c, secured to its surface. The third switch member 132 has a first contact arm 132a extending leftwards and always in contact with the disc portion of the first switch member and a second contact arm 132b penetrating and rightwardly extending through a hole in the hour detection member 126. The hour leaf drum 108 has a fourth switch member 133 as shown in FIG. 6d, secured to the left side of the drum. The fourth switch member 133 has a disc portion 133a which is always in contact with a contact piece 134 of the first switch SW 1  and a sector-shaped switch section 133b capable of being brought into contact with the second contact arm 132b of the third switch member. The first switch SW 1  is connected in series with a second switch SW 2 , a manually operable third switch and a buzzer B across a power supply E as in the first embodiment. 
     In operation, when an alarm signaling time which has been previously set is approached as the clock is being driven, the sector-shaped switch section 133b of the fourth switch member 133 is first brought into contact with the second contact arm 132b of the third switch member. At this time, the second switch member 131 and first switch member 130 are not yet in contact with each other, so that the buzzer B is not operated yet. When the preset alarm signaling time is further approached, the sector-shaped switch section 131b of the second switch member is brought into contact with the contact arm 130b of the first switch member, whereby the two slide contact pieces 135 and 134 are electrically connected to each other through the hour switch member 130-133. 
     As a result, the first switch SW 1  is closed. However, the second switch SW 2  is held raised at this time by the right hand projection 161 of the corresponding minute leaf and is not closed, so that the buzzer B is not operated yet. 
     When the alarm signaling time is reached, causing the movement of the fourth minute leaf 106d, the second switch SW 2  is no longer restricted by any projection on the minute leaves so that it closes itself by its own force. With the closure of the second switch SW 2  the whole circuit loop is closed, whereby the buzzer B is operated. The subsequent operation is the same as in the case of the first embodiment, so that it is not described here. 
     As has been described, according to the invention not only the afore-mentioned object is achieved, but also it is possible to permit the alarm signaling time to be set by turning the knob 15 in either direction since an alarm signaling time indicating device with an accuracy of ±0 minute can be realized by forming, for instance cams which do not have a perpendicular profile but have a triangular profile or providing slide switches as in the second embodiment.