US2400687A

US2400687A - Electric timepiece movement

Info

Publication number: US2400687A
Application number: US387825A
Authority: US
Inventors: Dales George Franklin
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-04-10
Filing date: 1941-04-10
Publication date: 1946-05-21
Anticipated expiration: 1963-05-21

Description

May 21', 1946. DALES 2,400,687

ELECTRJ EC TIME PIECE MOVEMENT Filed April 10, 1941 INVENTOR GEORQL FRANKL/N DALES .n: 9/ 'IY 89y ATTORNEYS) Patented May 21, 1946 ELECTRIC TIMEPIECE MOVEMENT George Franklin Dales, Akron, Ohio, assignor of one-third to Alton R. Wells, Akron, Ohio Application April 10, 1941, Serial No. 387,825

4 Claims.

This invention relates to a novel movement for electric watches or clocks. The movement is illustrated for use with a small dry cell battery, but it will function equally well with other sources of current.

An object of the invention is to employ novel means for use in all types of time pieces for controlling the timing and the length of the impulse as well as the manner of imparting the impulse given to the oscillating member, which may be a wheel or pendulum.

Another object is to provide a movement of the character referred to which is simple, reliable, accurate, and eflicient, as well as economical.

A further object is to provide an oscillating member carrying an armature, which member, in the illustrated form of the invention, is rotated in one direction by an electro-magnet attracting said armature and in the opposite direction by the force of gravity or some equivalent means. In the illustrated form of the invention the oscillating member controls the operation of a switch closing arm which intermittently closes a circuit through one or more electromagnets to keep the movement in operation.

A further object is to provide a ratchet wheel adapted to be connected to a gear train for operating the hands of the time piece and to move the ratchet wheel by a pawl connected to and operated by the oscillating member.

A further object is to provide a switch closing arm or member in the form of a bar fixed at one end, and to provide means engaging said bar adjacent its opposite end for preventing excessive vibration of said bar.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawing.

In the drawing:

Fig. 1 is a partial side elevation of one form of the invention omitting the train of gears which operates the hands,

Fig. 2 is a fragmentary view with the mechanism in a different position, and

Fig. 3 is a fragmentary top plan View.

Referring to the drawing the pendulum or oscillating member 8| is mounted for oscillation on a shaft 82 suitably mounted in the frame. The oscillating member 8| in this instance comprises a weighted depending arm 83 and a small arm 84 extending upwardly. Arm 83 carries an armature 85 intermediate its ends which is adapted to be attracted by the core 86 of an electro-magnet 81 when the latter is energized.

Arm 83 also carries a pin 88, projecting forwardly therefrom as viewed in Figs. 1 and 2, and the oscillations of the member 8| cause pin 88 to engage a projection 89 on the spring bar 99 in a manner to be described. In this form of the invention projection 89 is located intermediate the ends of bar 90 and is tilted slightly out of the plane of bar 90 as indicated. Bar 90 is fixed at one end 9| to the frame and the opposite end 92 rests upon a cork bumper 93 which acts as a damper to prevent excessive vibration of the bar. Bar 99 also carries a switch arm 93 which is adapted to be moved by pin 88 from the position shown in Fig. 1 to switch closing position with a switch member 94 as indicated in Fig. 2. Member 94 is secured to the frame and insulated therefrom and has an outwardly projecting portion 95 against which arm 93 makes contact.

Arm 84 has a pin 99 extending outwardly therefrom which carries one end of a spring arm or other rigid member 91 having a pawl 98 on its outer end to engage the teeth of a ratchet wheel 99 mounted for rotation in the frame. Ratchet wheel 99 operates the customary gear train for actuating the hands of the time piece, as will be understood, but since this gear train forms no part of the present invention, it has not been illustrated. Only a small number of teeth are shown on the ratchet wheel and it is preferred that there be or some multiple thereof, such as 120. Ratchet wheel 99 is adapted to be moved in a counter-clockwise direction as viewed in Figs. 1 and 2 and a plate spring I08 is arranged to prevent rotation of the ratchet wheel in the opposite direction.

The circuit shown in Fig. 1 comprises a source of electric current llll, which may be either a small dry cell battery or some other source, from which a conductor I02 leads to the switch member 94. A second conductor I93 also leads from the source of current to one terminal of the electro-magnet 81, and the other terminal of said electro-magnet has a conductor I94 leading therefrom to be grounded to the frame as at I95. Since end 9| of arm is in engagement with the frame, it will be apparent that a circuit will be closed through the electro-magnet whenever switch arm 93 is in engagement with switch member 94.

In operating the mechanism shown in Figs. 1 to 3 the oscillating member is first moved manually from the full line position to about the broken line position shown at the left in Fig. 1, in which position pin 88 will be out of engagement with projection 89 on bar 99. As the oscillating member swings from the latter position toward the right, pin 88 will engage projection 89 on its lower surface and move arm 93 into engagement with switch member 94, as shown in Fig. 2, to close the circuit and energize electro-magnet 81. Core 86 of the latter will then attract the armature 85 and pull the oscillating member toward the right. The oscillating member will continue its move ment toward the right to approximately the dash line position shown in Fig. l. The oscillating member will then return to the left and during this return movement pin 88 will engage the upper surface of projection 89, moving arm 93 further away from switch closing position than it was initially, but after pin 88 has passed across said upper surface, bar 90 and arm 93 will return to the position shown in Fig. 1. After completing its movement to the left the oscillating member will again swing to the right and the movement will be continuous, as will be understood.

During the movement of the oscillating member from left to right the core 86 is energized just prior to the time the oscillating member reaches the position shown in Fig. 2, and it becomes de energized just at the time the oscillating member reaches the full line position shown in Fig. l, which is its vertical position. Thus there is no tendency for the electro-magnet to attract the armature 85 as the oscillating member moves from its vertical position toward the right, and hence no tendency to slow down the movement of the oscillating member toward the right.

Each time the oscillating member swings from left to right, arm 84 moves in the opposite direction and causes pawl 99 to engage one of the teeth on ratchet wheel 99 to rotate the latter counter-clockwise. Thus, the movement of the ractchet wheel in this form of the invention is controlled directly from the oscillating member. When 60 teeth are used on the ratchet wheel, the movement need only be /60 of a revolution, or one tooth per second, and when 120 teeth are used, the movement need only be /120 of a revolution, or two teeth per second. This slower movement reduces wear on the pivots, simplifies the movement, gives greater efiiciency and thereby requires less operating power.

It will be apparent that the features described are well calculated to carry out the objects of the invention and to provide a movement which is at all times satisfactory.

This invention has many advantages over prior time piece movements. For example, the operating power required for the new movement is very substantially less than that heretofore required. The number of moving parts previously required has been materially reduced so that the elimination of friction losses which would be present by using such parts and the simple manner of imparting a periodic impulse to a free swinging oscillating member requires but a small amount of current. This factor makes possible a practical electrical movement having a self-contained battery for even small watch units. By using conventional resistance and relays, the movement may be adapted for operation upon a customary 110 volt A. C. current or upon as little as 3 volts A. C. current, as well as upon a one and one-half to four and one-half volt D. C. current.

Some other features and advantages are that my movement provides freedom from continuous A. C. hum which is a fault of a regular A. C. time piece. A reasonable amount of tilting of the time piece is also permissible with my movement, even when a pendulum is used as the oscillating member. Also, there is present a very high degree of isochronism, i. e., whether the battery is fully charged or nearly expended, the speed of the oscillating member is the same, although the distance it moves may be varied.

While I have illustrated and described one form of my invention it will be apparent that changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the subjoined claims.

What is claimed is:

1. In an electric time piece, an oscillating member, an armature carried by said member, switch operating means also carried by said member, an electro-magnet adapted to attract said armature, a ratchet wheel, ratchet wheel operating means carried by said member, means for energizing said electro-magnet, and a movable switch member arranged in the path of travel of said oscillating member and adapted to close a circuit through said energizing means, said switch member having a projection intermediate its ends, one side of which is engageable by said switch operating means when said oscillating member moves in one direction, the other side of said projection being engageable by said switch operating means when said oscillating member moves in the opposite direction, said switch member comprising a bar fixed at one end, and means engaging said bar adjacent its opposite end for preventing excessive vibration of said bar.

2. In an electric time piece, an oscillating memher, an armature carried by said oscillating member, switch operating means also carried by said oscillating member, an electro-magnet adapted to attract said armature, a ratchet wheel, ratchet wheel operating means carried by said oscillating member, means for energizing said electro-magnet, and a movable switch member arranged in the path of travel of said oscillating member and adapted to close a circuit through said energizing means, said switch member comprising a bar fixed at one end, and means engaging said bar adjacent its opposite end for preventing excessive vibration of said bar.

3. In an electric time piece, an oscillating member, an armature carried by said oscillating member, switch operating means also carried by said oscillating member, an electro-magnet adapted to attract said armature, a ratchet wheel, ratchet wheel operating means operative in timed relation with said oscillating member, means for energizing said electro-magnet, and a movable switch member arranged in the path of travel of said oscillating member and adapted to close a circuit through said energizing means, said switch member comprising a bar fixed at one end, and means engaging said bar adjacent its opposite end for preventing excessive vibration of said bar.

4. In an electric time piece, an oscillating member, an armature carried by said oscillating member, switch operating means also carried by said oscillating member, an electro-magnet adapted to attract said armature, means for energizing said electro-magnet, and a movable switch member arranged in the path of travel of said oscillating member and adapted to close a circuit through said energizing means, said switch member comprising a bar fixed at one end, and means engaging said bar adjacent its opposite end for preventing excessive vibration of said bar.

GEORGE FRANKLIN DALES.