US1518317A - Striking mechanism for electric clocks - Google Patents

Description

Dec.. 9, 1 24. 1,518,317

- M. P. FAVRE-BULLE STRIKING MECHANISM FOR ELECTRIC CLOCKS 21 F11ed Aug 1 3 is r Patented Dec. 9, 1924.

UNITED STATES MAURICE PHILIPPE FAVRE-BULLE, OF PARIS, FRANCE.

STRIKING MECHANISM FOR ELECTRIC CLOCKS.

Application filed August 21, 1923.

To all "LU/2.07)? it may concern:

Be it known that I, MAURICE PHILIPPE FAvRE-BULLE, a citizen of the French Bepuhlic, and residing at 59, Boulevard Beausejour, Paris, in the department of the Seine and Republic of France, have invented a certain new and useful Striking Mechanism for Electric Clocks, of which the following is a specification.

This invention has for its object to pro vide a striking mechanism adapted to all ty t cs of electric clocks. It consists essentially in a motor device, for instance, an electro-magnet whose armature is carried by the hammer of a striking mechanism mounted on the end of a flexible strip fixed to the frame. The shank of this hammer carries the pawl which, actuates a. ratchet wheel having ninety teeth, that is to say, as many teeth as times the hammer must strike during a complete revolution of the hour hand around the clock dial. A second wheel is fixed to the said ratchet wheel and bears on its periphery stopping teeth which are suitably spaced apart to allow the hammer to strike the desired number of blows at each hour and each half-hou1n A rocking lever is adapted to engage in the teeth of this second wheel in such a manner as to prevent its rotation; its other end bears upon a cam of suitable shape fixed on the minute-hand arbor.

lVhen the wheel rotates, the hammer can make a contact in the circuit of the electromagnet, and the striking mechanism comes into operation. In order that this mechanism shall strike its blows regularly one after the other, the rocking hammer is provided with a retarding device consisting of a me ronome pendulum whose period. of oscillation is very much greater than that of the hammer. This pendulum makes with the hammer a contact which is both mechanical and electric, the electric contact being arranged in series with the first contact hereinbefore mentioned. This first contact is broken, and consequently the striking mechanism no longer operates, as

soon as the wheel with stopping teeth is stopped by the lever actuated by the minute hand cam.

A constructional form of this invention is illustrated by way of example in the accompanying drawings, in which-- Figure 1 is a view of the general arrangement of the apparatus, and

. either side.

Serial No. 658,624.

Figures .2, 3 and at illustrate the stopping device carried by the rocking lever in its successive various positions.

Figure 5 is a plan view of the rocking lever showing its pivotal. end engaging a stopping tooth of the second wheel.

On the arbor l. of the minute-hand ro-- tating in the direction of the arrow, there is mounted a cam which is symmetric as regards its axis and has two rounded parts 3, 3 and two opposite flat surfaces 1, 4 corresponding to the hours and half-hours.

A lever 5 capable of rocking with anartlc 6 terminates in a. bevelled portion 7 which bears upon the periphery of the cam 2 The long arm of this lever is continually being pulled upwards by a suitably arranged spring At its other end the lever 5 carries a small. cylinder 9 having as its axis the rocliing axle G of the lever. This cylinder is split diametrally along a slot 11.) (Figures, 2, 3 and 4).

One of the front edges of this slot has a notch 11 which is oblique in relation to the generatrices of the cylinder.

On the axle 12, parallel to the axle 1. there is mounted a ratchet wheel .13 having out on its periphery ninety teeth spaced at equal distances apart. On the same axle 152 there is fixed a second wheel 14 having on its periphery teeth 15 spaced apart in. such a manner that the desired number of blows of the striking mechanism shall be given at each hour and at ea h half hour, the spaces between the teeth corresponding to the periods during which the striking mechanism operates. Thus, for instance, the group of three teeth 15, which in Figure 1 is situated opposite the lever 5, corresponds to 12.30 p. m., 1 oclock and 1.30 p. In. These teeth 15 come into engagement with the end of the lever 5. On a block 16 fixed to the clock frame there is suspended by means of a flexible strip 17 a striking hammer 18 terminating in a ball 19. This hammer carries a pawl 20 adapted to engage with the teeth of the wheel 13 and to move this wheel forwards at each movement of the hammer 18. The rearward movement of the wheel 18 is prevented by a suitably pivoted counter-pawl 21.

Facing the weight 19 of the hammer 18 there is arranged a gong 22. Two stops 25 and 24 limit the swings of the hammer 18 to This hammer carries laterally a mass of soft iron 25 constituting the armature of an elect-ro-magnet mounted. in a circuit 27 of the electric battery 28. In this circuit there is arranged a contact with a second contact piece 30 carried on the end of a flexible contacting strip 31 fixed to the hammer 18. At the side of the hammer 18 there is arranged a metronome pendulum :32 rocking on an axle and carrying at its lower part the weight 3rl: and at its upper part another weight 35 which vertically adjustable. The mass 34- carries a contact piece 36- adapted to make contact with a second contact piece carried by an elastic strip 38 which is likewise fixed to the hammer 18.

Around the aXle 33 there is arranged a flexible contacting strip 39 connected to one end of the winding of the electron'lagnet 26. It will thus be seen that the two contacts 29, B0 and 36, 37 are situated in series in the circuit 27. It is to be understood that the various parts hereinbefore mentioned are suitably insulated electrically from one another. The operation or this apparatus is as follows \Vhcn the bevel 7 of the lever 5 is bearing upon the rounded portions 3 and 3 of the cam 2, the lever turns with its axle 6 (position shown in Figure 3) and one of the teeth of the wheel la strikes against one of the sides of the slot 10. The wheel let is thus prevented from rotating. The hammer 18 is pulled by the position. of the spring strip 17 which is suitably tensioned towards the left of the figure, and the pawl 20 has a tendency to push the wheel 13, but the latter is held by reason of the stoppage of the wheel 14, and the contact-piece 30 does not meet the contact-piece 29. The circuit is open and the striking mechanism is not operating. hen the left hand end of the lever 5 meets one of the flat surfaces 4 or 4, it will drop suddenly down on to the bottom of the recess thus formed owing to the pull of the spring 8. Immediately the tooth 15 of the wheel let, which was stopped by the edge of the slot 11), escapes (l igure t) this escape being facilitated by the notch 11. hereinbefore mentioned. The wheel 14 is thus free to rotate until the following tooth meets the end of the lever 5, (position shown in Figure 2). Thus one tooth, and only one tooth, of the wheel 14 escapes at a time. After the wheel 14 has rotated, the hammer 18 continuing its swing towards the left hand of the figure, makes contact between the contact pieces and 30. The pendulum 32 pressing the contact piece against the contact piece 37, the circuit 27 is closed, the electromagnet 26 is energized, the armature is attracted and the hammer 18 strikes the gong. At this moment the pendulum 32 owing to its inertia, is driven forwards and contact is broken at 36. 37. The hammer 1.8 and the penrhrluln 32 swing, each according to its proper period. Contact will be made and consequently the hammer will strike a blow each time the contacts 25, and 36, 37 are made simultaneously.

At each swing of the pendulum towards the left hand, the pawl 20 moves the wheel. 18 forwards one tooth in the direction of the arrow F, and this movement will continue until the wheel 11 shall have been again stopped by the lever 5. At this moment, as has already been stated, the movement of the hammer 18 towards the left hand is insuthclent to make contact at 29,

30, and consequently the striking mochanism will cease to operate.

Having now described my invention, what I claim as new and desire to secure by Letters Patent 1. Striking mechanism for electric clocks com prising a motor device, a striking menr her, a pawl operated by the striking member, a. ratchet wheel having ninety teeth actuated by the said pawl, a second wheel co-axially fixed to the ratchet wheel and having teeth suitably spaced, a rocking lever adapted to strike against the teeth of the second wheel, a recessed cam. a minute hand arbor to which the cam is fixed and a pemlulum whose period of oscillation is higher than that of the striking member. the operation of the parts being such that when the lever engages the cam one tooth only at a time of the second wheel is allowed to escape, the striking member thereby closing the circuit of the motor device and bringing the striking mechanism into operation by the striking member being brought into mechanical and electrical contact with the said pendulum.

2. Striking mechanism for electric clocks comprising a power device consisting of an electro-magnet, a striking hammer, an armature carried by the hammer, a pawl operated by the hammer, a ratchet wheel having ninety teeth actuated by the said pawl, a second wheel co-axially fixed to the ratchet wheel and having teeth suitably spaced, a rocking lever adapted to strike against the teeth of the second wheel, a recessed cam, a minute-hand arbor to which the cam is fixed and a pendulum whose oscillation period is higher than that of the hammer, the operation of the parts being such that when the lever engages the cam one tooth only at a time of the second wheel is allowed to escape, the hannner thereby closing the circuit of the electromagnet and bringing the striking mechanism into operation by the hammer being brought into mechanical and electrical contact with the said pendulum.

3. Striking mechanism for electric clocks comprising an electro-magnct, a striking hammer, an armature carried by the ham- Til period is higher than that of the hammer,

the operation of the parts being such that when the lever engages the cam one tooth only at a time of the second wheel is allowed. to escape, the hammer thereby closing the circuit of the electro-magnet and bringing the striking mechanism into operation by the hammer being brought into mechanical and electrical contact with the said pendulum. J

In testimony whereof I have signed my name to this specification.

MAURICE PHILIPPE FAVRE-BULLE.

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