US3813873A

US3813873A - Switching device for electronic watch

Info

Publication number: US3813873A
Application number: US00343083A
Authority: US
Inventors: Y Nakagawa
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 1972-03-21
Filing date: 1973-03-20
Publication date: 1974-06-04
Anticipated expiration: 1991-06-04
Also published as: GB1406175A; JPS4895867A; CH599591B5; CH403873A4; DE2314130A1

Abstract

An improved switching device for an electronic watch is used for starting and stopping said watch. The device includes means for avoiding stress on the drive train and motor while setting the hands.

Description

1 Meat 11 1 1111 3,813,73 Nakagawa [4 June 1, 1974 [5 1 SWITCHING DEVICE FOR ELECTRONW 3,059,412 /1962 Epperlein 58/855 x WATCH 3.111,807 11/1963 Cloux 511/855 X 3,129,554 4/1964 Yz1sukawa.. 58/855 X Inventor: u u N g y Japan 3,296,790 1/1967 Schwaar 58/855 3,421,312 1/1969 Raval 58/855 [73] figwz g fi se'kosha 3,731,481 5/1973 Nakayama 58/1155 [22] Filed Mar M73 FOREIGN PATENTS OR APPLICATIONS 1 A l N 343 1,094,666 10/1957 Germany 58/855 Primary Examine'rRichard B. Wilkinson Foreign Application Priority Data Assistant Examiner-U. Weldon Mar. 21, 1972 Japan 47-27443 Attorney, Agem 0r Firm-Blum, Moscovitz Friedman & Kaplan [52] US. C1. 58/855, 58/23 R [51] Int. Cl. G041) 27/09 57 ABSTRACT [58] Field of Search 58/85, 5, 57, 63; R,

58/23 R, 23 D, 23 BA, 34 33 An improved swltchmg device for an electronic watch is used for starting and stopping said watch. The de- [56] References Cited vice includes means for avoiding stress on the drive UNITED STATES PATENTS train and motor while setting the hands.

2,947,137 8/1960 Berry et a]. 58/855 9 Claims, 2 Drawing Figures 1 I SWITCHING DEVICE FOR ELECTRONIC WA TCH BACKGROUND OF THE INVENTION In general, conventional electronic watches are not provided with a switch for cutting the electronic circuitry from the source of energy, namely, a battery. As a result, when it is desired to set the hands of the watch, as when making a correction, undesired and possibly damaging forces are exerted by the motor on the gear ting the hands. The present invention is designed to overcome these difficulties;

SUMMARYOF THE INVENTION A stem which can be moved in opposite axial directions from the exterior of a watch'engages an end of a pivotable transmitting and regulating arm. The opposite end of the pivotable arm is linked to a switch lever which engages both mechanically and electrically a switch pin. When the watch is operating, the switch lever is in contact with the switch pin, energizing the electronic drive means of the watch. The watch includes a gear train for setting the minute hand and the hour hand of the watch. The minute wheel of the watch is coupled by frictional engagement with the cannonpinion which carries the minute hand. Movement of the stem cuts off power to the drive train and then holds it stationary while the minute and hour hands are adjustcd as by a crown. The frictional coupling between the minute wheel and the cannon-pinion acts as a clutch whereby the drive train can be held stationary while the minute and hour wheels are rotated for setting the hands. Further, since the watch can be instantly restarted by movement of the stem, the watch can be set accurately to the second.

Accordingly; an object of the present invention is to provide an improved switching device for an electronic watch which makes it possible to set the watch to the nearest second.

Another object of the present invention is to provide an improved switching device which serves for starting and stopping the motor of thewatch and which, in stopped position, permits setting the minute and hour hands without damage to any of the components of the watch, and holds the drive train stationary.

A further object of the present invention is to provide an improved switching device for an electronic watch which operatesindependently of the crown used for setting the watch.

Yetanother object of the present invention is to provide an improved switching device using frictional engagement between components thereof where the frictional engagement serves as a clutch.

An important object of the present invention is an improved switchingdevice for an electronic watch where the switching device is simple in construction, suitable for mass-production and low in cost.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangement' of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a plan view of an improved switching device for an electronic watch in accordance with the present invention; and

FIG. 2 is a sectional view of the switching device and gear trains.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to HO. 1, arm 1 is'pivoted on arbor 2. Stem 3 which is analogous to a winding stem in a spring-driven watch, can be pushed inward or pulled outward from the exterior of the watch. The normal runningposition for stem 3 is the inward position marked (a) in which the tip of stem 3 makes contact with arm I placing it in the more counterclockwise of the two positions shown. Arm 1 has proximate its lower end (5a) a transmitting pin 4 mounted thereon. the transmitting pin 4 projecting both upwardly and downwardlyfrom arm I. Mounted on circuit block C is a switch lever 5 which pivots around axle 7 which is screwed into third wheel bridge 6. Switch lever 5 is held in position on screwed axle 7 by means of screw 8.

Switch lever 5 has an elongated opening 5b at its base end 5a through which protrudes pin 4. Rotation of arm 1 as a result of movement of stem 3 causes switch lever 5 to rotate correspondingly as the result of contact of pin 4 with the walls of opening 51). Switch lever 5 has a second top end 50 which makes contact proximate tip 5d with switch pin 9, mounted on circuit block C, when lever 5 is rotated counterclockwise in response to a corresponding rotation of arm l.-Arm Sc, preferably, is flexible. Topend 5c and switch pin 9 are electrically connected into the circuitry of the watch so that contact therebetweensets the watch motor into operatIon.

Spring 10 is fixed at one end of portion 1'! (FIG. 2) of plate 16 and makes contact at the other end with the lower end of the pin 4. Spring 10 is so positioned that it biases pin 4 and therefore arm 1 and switch lever 5 in clockwise direction; movement in clockwise direction would break electrical contact between tip 5d and switch pin 9, thereby stopping the drive motor of the watch. However, stem 3 when in position (a) forces both pivoted

members

1 and 5 in counterclockwise direction against the urging of spring 10 so that electrical contact is made between tip 5d and switch pin 9. Switch pin 9 is held in circuit block C by solder 12.

The driving train of the indirect center second system electronic watch of the present invention is shown in FIG. 2. The train includes third wheel 15, a third pinion 14 supported between third wheel bridge 6 and supporting means 13. It further includes a centerv second pinion 19 which meshes with third gear 15 and is mounted on a second shaft 18 which passes through tube 17 mounted on plate 16.

' A cannon-pinion 21 is frictionally engaged with a minute gear 20 which in turn meshes with third pinion 14 and is driven thereby. Also, hour wheel 22 is engaged with cannon-pinion 21.

A disk 23 is mounted on third pinion l4 coaxially with third wheel 15 and is fixed thereto. Disk 23 is mounted at the same level in the watch as arm 1 and proximate thereto. Frictional disk 23 may be made of a-material having a high coefficient-of-friction or may be coated with such a material. Thus the disk may be made of a slightly elastic rubber or it may be coated with a rosin such as is used on a violin bow.

As aforenoted, an object of the present invention is .to make it possible to set the hour and minute hands while holding the second hand still. When stem 3 is moved to position (b) arm 1 rotates in clockwise direction under the urging of spring and electrical contact with switch pin 9 is broken, stopping the watch motor. Further, arm 1 moves into contact with the periphery of wheel 23 holding same firmly against rota tion. To increase the firmness with which arm 1 holds disk 23 stationary, arm 1 is preferably fitted with a projection or cusp la at the point of contact between arm 1 and disk 23. The firmness with which disk 23 and wheel are held immovable is increased when the disk 23 is slightly flexible so that the cusp 121 can indent it slightly. The disk is preferably of aslightly flexible rubber. Alternatively, the disk may be coated with a material such as rosin to increase its coefficient of friction.

Arm 1 is rotated in a counterclockwise direction when the tip of stem 3 is pushed inwardly to the position marked (a) in FIG. 1, and simultaneously switch lever 5 is moved in the same-direction by means of transmitting pin 4. Contact is thereby made between tip 5d of switch lever 5 and switch pin 9, starting the motor of the watch. As is evident from FIG. 1, cusp la is moved away from the friction disk 23. As a result, all of the hands, namely the hour, the minute and the second hands can move normally in response to the operation of the watch motor 30. The torque developed by the watch motor is transmitted to that portion of the watch mechanism shown in FIG. 2 through third wheel 15. The rotation of third wheel 15 is transmitted to center second pinion 19 and to second shaft 18 on which the second hand is mounted.

Third wheel 15 also drives third pinion 14 which in turn rotates minute wheel 20 and thereby cannonpinion 21. Cannon-pinion 21 carries minute hand 24, and hour wheel 22 carries hour hand 25. Cannonpinion 21 engages minute wheel 20 frictionally, this frictional engagement constituting a clutch mechanism.

The frictional engagement may convenienly be between the common shaft of minute wheel 20 and cannon-pinion 21 and either of these

wheels

20 and 21.

To set thehands, the stem 3 is pulled outward to position (b) whereupon transmitting and regulating arm 1 is rotated about arbor 2 under the biasing force of spring 10. When this occurs, the cusp 1a of lever 1 presses against frictional disk 23 stopping same and also third wheel 15. Consequently, second pinion 19 receives no rotational force from third gear 15 so that second shaft 18 is stationary. Simultaneously, switch lever 5 is turned in clockwise direction about pivot 7 breaking contact with switch pin 9. Conveniently, aperture 5b in arm 5 is elongated to allow for the fact that arm 1 and lever 5 do not rotate around the same axis.

With the watch stopped, a setting crown (not shown) is rotated and the rotational force is transmitted to pinion 21 through a setting wheel (not shown). However, due to said clutch mechanism, no stress is applied to the gear train or motor. Furthermore, shaft 18 which carries the second hand remains stationary during the setting procedure.

As aforenoted, in accordance with the present invention, it is possible to stop the second hand at any desired point by pulling stem 3 outwardly to stop the watch motor and simultaneously stop the rotation of disk 23 and wheel 15 fixed thereto. Also, the second hand is stopped by means of the center second pinion 19 which is engaged with the third wheel. Consequently, no movement of the second hand takes place during adjustment of the minute and hour hands. Also, no energy is taken from the battery during adjustment of the hands because the electrical circuit is open at that time. It will be apparent that it is possible to start the second hand in precise match with a reference signal by pressing the stem 3 inwardly thereby releasing the friction wheel 23 and starting the watch mechanism simultaneously.

The simultaneous stopping of the drive motor and train and engagement of brake mechanism (arm 1 and disk 23) automatically eliminates the danger of imposing damaging stress on the gear train and motor during setting of the hands. The combination of the above stem action with a clutch mechanism for setting the hands while the drive train is held stationary provides unusual accuracy in setting a watch of the present invention.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. I

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be'said to fall therebetween.

What is claimed is:

1. In an electronic watch including electrical drive means, switch means externally manipulatable between on and off positions for turning said electrical drive means on or off, a drive train powered by said drive means, minute hand and hour hand, a wheel operatively connecting said drive train said minute hand and said hour hand, and frictional clutch means between said wheel and said minute hand, the improvement comprising a disc mounted for rotation with said wheel and an arm having first and second ends, said arm being operatively connected with said switch means to make sufficiently firm contact with said disc to prevent rotation thereof when said switch means is in off position, the halting of said drive means and of said drive train by said disc and wheel and said frictional clutch means making it possible to adjust the position of said hour and minute hands without stressing said drive means said disk is sufficiently flexible to be indented by said cusp. h

5. The improvement as defined in claim 3 wherein said disk is of a slightly flexible rubber.

6. The improvement as defined in claim 3 wherein said disk. is coated with a material having a high coefficient of friction.

7. The improvement as defined in claim 1 wherein said arm has first and second ends and said switch means includes spring means engaging said arm, a stem movable between inward and outward positions from the exterior of said watch, said inward and outward positions corresponding to on and off switch positions, said stem in said inward position engaging said arm and holding same away from said disc, and in said outward position permitting said arm to move and remain in firm contact with said disc thereby holding same stationary.

8. The improvement as defined in claim '7 further comprising an electrical switch pin adjacent said switch means, said switch means including a pivoted switch lever having top and base ends, said base end being linked to said second end of said arm, the relative positions of said arm and switch lever being such that said arm when disengaged from said disc holds said top end of said switch means against said switch pin and activates said drive means and when pressed against said disc holds said top end away from said switch pin thereby deactivating said drive means.

9. The improvement as defined in claim 8 wherein said arm has mounted thereon near its second end a transmitting pin, and said base end is apertured for re ception of said transmitting pin, said arm and said lever being so positioned relatively to each other that movement of said arm from disengagement to engagement with said disc is transmitted through said transmitting pin to the walls of said aperture causing said top end of said lever to break contact with said contact pin and vice versa when said arm is moved from engagement to disengagement with said disc.

Claims

1. In an electronic watch including electrical drive means, switch means externally manipulatable between on and off positions for turning said electrical drive means on or off, a drive train powered by said drive means, minute hand and hour hand, a wheel operatively connecting said drive train said minute hand and said hour hand, and frictional clutch means between said wheel and said minute hand, the improvement comprising a disc mounted for rotation with said wheel and an arm having first and second ends, said arm being operatively connected with said switch means to make sufficiently firm contact with said disc to prevent rotation thereof when said switch means is in off position, the halting of said drive means and of said drive train by said disc and wheel and said frictional clutch means making it possible to adjust the position of said hour and minute hands without stressing said drive means and the part of said drive train intermediate said drive means and said wheel.

2. The improvement as defined in claim 1 wherein said arm has a cusp thereon so disposed that said arm makes contact with said disk at said cusp.

3. The improvement as defined in claim 1 further comprising spring means urging said arm toward said disk.

4. The improvement as defined in claim 2 wherein said disk is sufficiently flexible to be indented by said cusp.

6. The improvement as defined in claim 3 wherein said disk is coated with a material having a high coefficient of friction.

8. The improvement as defined in claim 7 further comprising an electrical switch pin adjacent said switch means, said switch means including a pivoted switch lever having top and base ends, said base end being linked to said second end of said arm, the relative positions of said arm and switch lever being such that said arm when disengaged from said disc holds said top end of said switch means against said switch pin and activates said drive means and when pressed against said disc holds said top end away from said switch pin thereby deactivating said drive means.

9. The improvement as defined in claim 8 wherein said arm has mOunted thereon near its second end a transmitting pin, and said base end is apertured for reception of said transmitting pin, said arm and said lever being so positioned relatively to each other that movement of said arm from disengagement to engagement with said disc is transmitted through said transmitting pin to the walls of said aperture causing said top end of said lever to break contact with said contact pin and vice versa when said arm is moved from engagement to disengagement with said disc.