Patent Publication Number: US-4320482-A

Title: Switch for an electronic timepiece

Description:
This is a continuation of application Ser. No. 50,126, filed June 19, 1979, and now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a rotary switch of an electronic timepiece. Recently electronic timepieces have become highly developed, and especially techniques used for realizing a quartz crystal timepiece have remarkably advanced by development of the timepiece integrated circuit (IC). In a quartz crystal timepiece, a motor is driven by frequency divided signals produced from a quartz oscillator. 
     Conventionally, frequencies of a quartz crystal have been determined according to a fixed frequency dividing ratio and thereby a trimmer condenser have been used as a step regulator. However, as for this method, current consumption is varied by a capacitance variation of the trimmer condenser caused by temperature variation, and therefore a current value of an oscillating circuit is set accounting for the current variation. 
     Attendant on recent prolongation of the lifetime of the quartz crystal timepiece, it has become necessary to decrease the current consumption of timepiece IC and if the trimmer condenser is used for regulating frequency in steps, it is necessary to set the current consumption at a high value in the normal state when the current value of the oscillating circuit is set, so that the oscillating circuit can be operated normally even if the capacity of the trimmer condenser varied. Accordingly it is difficult to decrease the current consumption. Further, in the conventional fixed frequency division, the frequency of the quartz crystal vibrator is tuned with the frequency set according to the frequency dividing ratio and the available percentage of the quartz crystal frequency having a narrow regulating range is decreased. For the quartz crystal having a narrow regulating range, the variable frequency division technique has been adopted. In this case, the switch to tune the frequency dividing ratio of the timepiece IC is necessary and the &#34;teeth of a comb&#34; shaped switch plated as shown in FIG. 1 was invented. In this case, however, it was necessary to tune the frequency by changing the &#34;teeth of the comb&#34; of the switch plate according to each of possible combinations and to complete every combination and further to prepare a number of shapes for prior assembling. When the switch plate was changed it was troublesome to remove the switch plate and also it was necessary to prepare every part for subsequent service when the timepiece was adjusted after marketing. In the manufacturing process, four pieces of the &#34;teeth of the comb&#34; shaped switch plates should be punched out before cutting each of the teeth and to manufacture 15 kinds of switch plates if every one of the switch plates were provided with four terminals. 
     Accordingly, it is an object of the present invention to provide a variable frequency dividing switch a wide adjustable range and easily adjustable by arranging more than two rotary switches having a couple of input terminals on a circuit block. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a conventional switch construction, 
     FIG. 2 is an embodiment of the present invention showing a sectional view of a switch, 
     FIG. 3 is a plan view showing a rotor of the switch in the direction of the circuit board 2, 
     FIG. 4 is a section taken on line A--A&#39; in FIG. 3, 
     FIG. 5 is a plan view showing a switch mounted on a circuit block, and 
     FIG. 6 is a sectional view showing another embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to an embodiment of the present invention, the construction of the present invention will be illustrated in conjunction with FIGS. 2, 3 and 4. 
     In FIG. 2 a base plate 1 is opposite a circuit board 2 provided with circuit patterns 2c and 2d composing switch terminals. Two projections 4a, 4b of a rotor 4 composed of an elastic conductor contact with the patterns 2c and 2d. The rotor 4 may be molded resin and plated. An elastic member 5 is rotatably fixed together with a drive pin 3, provided with a slot 3b, by a caulking portion 3a of the drive pin 3. 
     When the circuit board 2 is fixed to the screw pin of a base plate 1 not shown, the projection 4a of a rotor 4 and the pattern 2c, and the projection 4b and the pattern 2d contact by elasticity. 
     FIG. 3 shows a plan view of the rotor 4 and FIG. 4 shows a section taken on line A--A&#39; in FIG. 3. 
     Referring then to FIG. 5 showing the rotary switch mounted on a circuit block 7. Numeral 1 is a base plate and numeral 6 is a quartz crystal vibrator composing a circuit block. Numeral 7 is an IC provided with variable frequency dividing terminals 10a, 11a, 12a and 13a which are wire bonded to patterns 10, 11, 12 and 13. Numeral 8 is a transfer molded resin to mount the IC thereon. 
     Referring to the operation of the switch in conjunction with FIG. 5, in case the rotor 4 is electrically in contact with the base plate 1 by section 5a of the elastic member 5 shown in FIG. 3, the switch is in state &#34;O&#34; when the patterns 10b, 11b and 4a, 4b of the rotor 4, the patterns 12b, 13b and 5a, 5b of the rotor 5 do not contact. If the switch is provided with two input terminals as shown in FIG. 5, the operation of the switch has four combinations as shown in Table 1. 
     
                       TABLE 1                                                     
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     Moreover, if there are two switches the operation of the switch has sixteen combinations as shown in Table 2 below. When the switch B rotates in the case that the switch A is in the &#34;00&#34; state, the projection 5b contacts with the primary pattern of the pattern 13b while the projection 5a doesn&#39;t contact with any pattern, and the switch is in a state &#34;2&#34; shown in Table 2. If the switch B rotates more, the projection 5b doesn&#39;t contact with a pattern and the projection 5a contacts with the pattern 12b in place and the switch is in a state &#34;3&#34; shown in Table 2. If the switch B rotates further, the projection 5b contacts with the other side of the pattern 13b again and since the projection 5a is in the same state as &#34;3&#34; in Table 2, the switch is in a state &#34;4&#34; in Table 2. When the switch A rotates further, the projection 4b contacts with the pattern 11b while the projection 4a doesn&#39;t contact a pattern. If the switch B is restored to the position shown by a solid line in FIG. 5, it is in a state &#34;5&#34; in Table 2. If the switch B is rotated after the switch A is rotated as mentioned above, the switch is in a state &#34;8&#34; in Table 2. If the switch A is rotated in turn and the switch B is operated as mentioned before, sixteen combinations as shown by Table 2 are possible. 
     In case the elastic member 5 is made of a thin plate in view of the switch construction, if the pin indentation system is adopted as shown in FIG. 6, the deformation of the elastic member caused by calking is prevented. 
     
                       TABLE 2                                                     
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1 ..... 0 0 0 0       9 ..... 1 0 0 0                                     
2 ..... 0 0 0 1      10 ..... 1 0 0 1                                     
3 ..... 0 0 1 0      11 ..... 1 0 1 0                                     
4 ..... 0 0 1 1      12 ..... 1 0 1 1                                     
5 ..... 0 1 0 0      13 ..... 1 1 0 0                                     
6 ..... 0 1 0 1      14 ..... 1 1 0 1                                     
7 ..... 0 1 1 0      15 ..... 1 1 1 0                                     
8 ..... 0 1 1 1      16 ..... 1 1 1 1                                     
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     As illustrated, since the step regulating switch is a rotatory system according to the present invention, an assembling process is simplified and a supply of step regulating parts for service becomes unnecessary. Further, the assembly becomes easy because of the simple switch construction. Moreover, with four combinations for each of switches, the rotation angle of the rotor can be divided every 90 degrees and the switch position adjustment steps can be spaced equally every 90 degrees within the range the switches are used.