US3553396A

US3553396A - Switch device for an electric clock

Info

Publication number: US3553396A
Application number: US786304A
Authority: US
Inventors: Chika Wakabayashi
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-23
Filing date: 1968-12-23
Publication date: 1971-01-05
Anticipated expiration: 1988-01-05

Abstract

A switch device for an electric clock inserted in series with the circuit of a DC motor for winding up the drive spring, said switch device comprising a switch cam consisting of a disc conductor and a disc insulator, each having a circumferential Vshaped groove communicating with each other, a resilient conductor or contact engaging said groove and another contact member contacting constantly with said disc conductor, the motor circuit being closed and opened intermittently by the switch device and because of the sliding operation, contact point troubles are eliminated.

Description

United States Patent Chika Wakabayashi No. 1275 Shimonoge, Kawasaki-shi, Japan [21 J Appl. No. 786,304

[22] Filed Dec. 23, 1968 l 45] Patented Jan. 5, 1971 [72] Inventor [54] SWITCH DEVICE FOR AN ELECTRIC CLOCK 2 Claims, 5 Drawing Figs.

[52] US. Cl. 200/35, 58/41 [5 1] Int. Cl H0lh 7/08 [50] Field ofSearch 58/4 I (All);

ZOO/166138, 166.1, 35

[56] References Cited UNITED STATES PATENTS 2,909,029 10/ l 959 Witte 5 8/41 3,031,837 5/1962 Homing 58/4l(B) 3,l48,3l3 9/1964 Hancock 58/4l(A)(X) 3,267,659 8/1966 Hancock 58/4l(B) 3,276, l 99 10/1966 lshikawa et al. 58/41 3,319,414 5/1967 Schwab 58/41 3,455,103 7/1969 Konno 58/41 Primary Examiner-Herman 0. Jones Attorney-William W. Downing, .lr.

ABSTRACT: A switch device for an electric clock inserted in series with the circuit of a DC motor for winding up the drive spring, said switch device comprising a switch cam consisting of a disc conductor and a disc insulator, each having a circumferential V-shaped groove communicating with each other, a resilient conductor or contact engaging said groove and another contact member contacting constantly with said disc conductor, the motor circuit being closed and opened intermittently by the switch device and because of the sliding operation, contact point troubles are eliminated.

SWITCH DEVICE FOR AN ELECTRIC CLOCK This invention relates to an improvement in clocks of the i spiral drive spring adapted to be intermittently wound by a DC motor having a cell as the electric source therefore. However in electric clocks of the type mentioned which, for operating the main clock mechanism, are equipped with an operating switch inserted in series in relationship to the motor which is also in the circuit, since the current from the motor flows directly to the contacts of the switch, the circuit intermittently closes and opens when the contacts are separated and the counter electromotive force generated in the amount of the 1 winding operation of the motor occurs between the contacts,

thereby resulting in a spark or electric arc discharge which causes deformation and fusing of the contacts and thus constitutes major causes of trouble in the electric clock.

To eliminate the above trouble, it is considered to make use of the sliding-type contact in place of the pressure type contact. That is, in the sliding-type contact, the defects of the electric conductivity, because of the dirt or deformation, etc., 1 are eliminated sufficiently by the so-called self-cleaning operation.

Accordingly a salient object of the present invention is to provide a new battery clock having a winding device for the drive spring which will overcome the above defects existing in "the art.

Another object of the present invention is to provide a winding device for the drive spring of an electric clock in which the switch in the motor circuit consists of a special mechanism for eliminating the defects of electric conductivi- Another object of the present invention is to provide an electric clock in which the clock mechanism may be almost free from the load which may influence the precision in other winding clocks. 1

- To accomplish the above and other advantageous objects, this invention comprises a winding device for the drive spring of an electric clock having as its drive source a helical or spiral spring adapted to be wound intermittently by a DC motor provided with a cell as its electric source and a sliding-type switch inserted in series in the circuit of said DC motor.

Further objects and advantages 'of the invention will become more readily apparent to persons skilled in the art from the following detailed specification and annexed drawings, and in which drawings:

FIG. I is a view partly in elevation and partly in section illustuning the principal portion of a preferred embodiment of the present invention;

FIG. 2 is a sectional view of the device illustrated in FIG. 1;

FIG. 3 is a fragmentary plan view of the principal portion of the present invention;

FIGS. 4a and b are the sectional views of the switch cam at different positions, with FIG. 4a being a section taken on line IV-IV of FIG. 5a and FIG. 4b being a similar section taken at right angles to the showing of FIG. 4a; and

FIGS. 50, 5b and 5c are respective top plan and left and right hand elevational views of the switch cam.

Referring to the embodiment illustrated in the drawings, it can be seen from FIG. 1 that a conventional helical drive spring is provided for driving a conventional main clock mechanism of an electric clock. One end of the spring 10 is connected to a drive wheel 9 adapted to rotate together with a contact wire spring 5 fastened at one end to the contact plate 19. This contact plate 19 is fastened on the drive wheel 9 by a screw 6 and the other end of the drive spring 10 is connected to the third wheel 13 which is fastened to the shaft 2 and drives the clock mechanism through the fourth wheel pinion 15 and the fourth wheel 16. The switch cam 3 also is fastened to shaft 2. Accordingly, cam 3 and the third wheel 13 are driven together by the drive spring 10 and the shaft 2 is pivoted to the frame plate 1. The drive wheel 9 is fit loosely on the pipe-shaped extension portion of the cam 3 that is fastened to the shaft 2, and as is clear from FIG. 2, it is driven intermittently by worm 11 fastened to the rotor shaft of the DC motor 12. The cam 3 serving as a switch consists of two discs, elements l7 and 18 fastened together as one body, which is illustrated in FIG. 4 in section, that is, onedisc 17 is made of electrically conductive material and the other disc 18 is made of electric insulating material.

The cam 3 is formed like a double grooved pulley, as shown in FIG. 1 and 2, and each

disc element

17 and 18 has a V- shaped peripheral groove 17 and 18', respectively, on its circumference. Consequently, cam 3 has two parallel grooves on its circumference. To make the cam function as a switch, one portion of the circumference of the disc is cut off on one side as shown in FIGS. 4a, 5a; 5b and 5c so as to make the two parallel grooves communicate with one'another and opposite side of the circumference also is cut off reversely, so that each of the grooves has its bottom in difi'erent material, that is, the electrically conducting or insulating material, respectively.

To understand the function of the cam as a switch, an illustration is shown in FIG. 4a and FIG. 4b. There the conducting disc 17 and the insulating or nonconducting disc 18 revolve as a unit and free end of the contact wire spring 5 (shown in FIG. 3 also) is pressed in one of the grooves. Then if the cam 3 revolves from the position of FIG. 4a to that of FIG. 4b, the contact spring 5 is shifted from the groove 18 to groove 17' because due to its elasticity, the contact spring 5 slides along the cut off face 17" and moves from the groove 18' to the bottom of the other groove l7 Namely the contact spring 5 is shifted very fast from the disc insulator 18 to the conducting disc 17, and vice versa. This snap action of the contact spring comes from the elasticity of the contact spring 5 and cutoff faces 17" and 18" of the discs, forming crossover locations so that the contact spring wire 5 can shift from one disc to the other. In the drawings the conventional clock mechanism is abbreviated.

The switch device for the electric circuit of the motor 12 will be more fully described. The lead wire 8 connects one of the terminals of the motor to the contact plate 4 fixed at its one end on the frame plate 1 and having its other end in sliding engagement with the surface of the conductive disc 17 of the cam 3. The resilient contact spring 5 fastened by the screw 6 on the contact plate 19 is adjustedso as to press slightly in the V-shaped groove and revolves together with the drive wheel 9. The contact plate 4 supported by an insulator (not shown in the drawings) slides on the surface of the contact plate 19. And the lead wire 7 connects the contact plate 4 and one terminal of the battery, (not shown). The other battery terminal is connected to the other terminal of the motor. Thus if the contact spring 5 is in the position of FIG. 4b, the current flows from the battery through one of the terminals of the motor, through the motor, the other terminal of the motor, through lead wire 8, the contact plate 4, the electrically conductive disc 17 of the cam 3, the contact spring 5, the contact plate 19, the contact plate 4' and the lead wire 7, to the other terminal of the battery. Then the motor is rotated.

The worm 11 on the motor shaft drives the drive wheel 9, accordingly the contact spring 5 also revolves together with it and slides down in the groove of the insulator or nonconductive disc 18 of the cam 3 to the side opposite from the position of FIG. 4a. Consequently the contact spring 5 is shifted by snap action to the groove 18' of the insulating disc 18. This results in opening the circuit for DC motor 12.

The drive spring 10 is wound to the proper extent by this drive wheel revolution and this is the drive force for the main clock mechanism. The third wheel 13 and the cam 3 both fastened on the same shaft 2 continue to revolve together, accordingly the contact spring 5 also slides down in the groove 18 of the insulating disc 18 of the cam until it falls into the groove 17' of the conductive disc 17, which results in closing When the drive spring 10 has been wound in the manner described, the force of the thusly wound spring will cause the third wheel 13 to rotate to actuate the main clock mechanism.

Rotary movement of this third wheel 13 is controlled by the conventional balance mechanism (not shown) of the clock.- The contact spring also revolves at the same speed while it slides in the groove of the insulated disc 18 of the cam 3. And 1 the time interval from opening the circuit of the motor to clos ing it is predetermined according to the shifting points of the contact spring 5 on the circumference of the switch cam device.

The characteristics of this switching system for the motor 12 will be more clear by the following explanation.

That is, the third wheel 13 is driven by the drive spring wound intermittently and it rotates continuously in the unidirection, and the drive wheel 9 also is driven in the same direction by the worm ll intermittently. The resilient contactspring 5 slides always on the same half side of the circumference of the cam 3, and when the contact spring 5 falls in the groove of the disc conductor 17, the contact spring 5 itself runs in that groove until it comes out of it and enters into the groove of the disc insulator 18 and stops because of opening the circuit for the motor 12, as the result the drive spring 10 is wound by this revolution of the drive wheel 9, and the switch cam 3 revolves at the same speed with the third wheel 13, the contact spring 5 slides in the groove parallel to the groove where the spring 5 "ran justbefore until it falls again in the groove of the conductive disc 17.

The above described switching and wind upmotion is re'-" peated ata predetermined time interval-and the drive spring 10 is interrnittently'wound at the predetermined time interval.-

The invention is not to be confined toan strict conformity to the showings in the drawings bu't chang o modificationsmay be made therein so far as such: anges o'r modifications make no material departure frorr'i'ltfr spirit and scope of the appended claims.

LA switch device for the circuit of motor forinte'rmittently winding up the drive spring q.j f 'arifelectric clock mechanism, includinga wheel shaft for t'he'clock mechanism,

a switching cam means'carried by'said wheelshafti's'aid cam m'eanscomprising anelectrically conductive member andim insulating-member, said members having contact accommodating tracksthereon said tracks including crossover'portions, a resilient contact member mounted for rotation relative to said cam means and including-a portion making sliding contact with said tracks, and said motor circuitfurther including contact members in electrical contact with said electrically conductive member and said resilient contact member whereby amotor as long as said resilient contact member makes a sliding contact with the track in said electrically'con" ductive member. I

2. A switch device as claimed in claim 1 in which'said electrically conductive member and said insulating memb'er'are

Claims

1. A switch device for the circuit of a DC motor for intermittently winding up the drive spring of an electric clock mechanism, including a wheel shaft for the clock mechanism, a switching cam means carried by said wheel shaft, said cam means comprising an electrically conductive member and an insulating member, said members having contact accommodating tracks thereon, said tracks including crossover portions, a resilient contact member mounted for rotation relative to said cam means and including a portion making sliding contact with said tracks, and said motor circuit further including contact members in electrical contact with said electrically conductive member and said resilient contact member whereby a motor as long as said resilient contact member makes a sliding contact with the track in said electrically conductive member.

2. A switch device as claimed in claim 1 in which said electrically conductive member and said insulating member are each a circular disc, said discs concentrically arranged, said tracks comprising a circumferential V-groove in the periphery of each disc and said crossover portions comprising diametrically opposite, reversely inclined surfaces providing communications between the bottoms of the respective grooves.