US2843999A - Electric clock - Google Patents

Description

July 22, 1958 G. R. SMYTH ELECTRIC CLOCK Filed Nov. 30, 1955 HII ILMI Z Vii/r5151??? l I n I llI/llf/l/llllllIl/Ax I A w ELECTRIC CLOCK Gordon R. Smyth, Chicago, Ill., assignor to Rubber Products, Inc., a corporation of Illinois Application November 30, 1953, Serial No. 394,985

6 Claims. c1. 58-2 The present invention relates .to clocks wherein the minute hand is driven directly by a large, concealed ring gear, while the hour hand is driven by the minute hand.

When the minute hand is fastened to the ring gear a special clutch is required to permit the hands to be turned independently of the motor. Also, it is difficult to fasten a hand to a light gear ring without creating some distortion in the latter.

The object of the present invention is to produce a construction wherein the minute hand is driven satisfactorily by the gear ring, but which permits the minute hand to be turned in either direction, to set the clock, independently of the gear; and only a slight push or pull on the minute hand being needed for manual operation of the same.

The various features of novelty whereby the present invention is characterized will hereinafter be pointed out with particularity in the appended claims; but, for a full understanding of the invention and its object and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is a front view of a clock embodying the present invention;

Fig. 2 is a vertical, central section, on a larger scale, through the upper half of the clock, with the gear train between the hands shown in elevation;

Fig. 3 is a section similar to and on a larger scale than Fig. 2, showing only the parts in the region of the gear train which is in section instead of being an elevation;

Fig. 4 is a fragment of the ring gear, the knurled side of the same being shown;

Fig. 5 is a rear view of the tip end of the minute hand, showing the spring wire attached thereto and forming an extension thereof;

Fig. 6 is a side view of the spring wire detached from the clock hand; and

Fig. 7 is a perspective view of the glass dial holding clamp.

Referring to the drawing, 1 represents any suitable hollow base in which the usual electric motor, not shown, is mounted. Rising from the base is a round, flat clock case comprising a hollow annulus or ring 2 and a glass disc 3 forming the back of the casing and conveniently serving as the dial for the clock.

Annulus 2, in radial section, forms three sides of a square; the fourth side, at the rear of the clock being left open. The wall 2 that forms the outer periphery of the annulus is wider than the inner annular wall 2 Since both of these walls are connected to the flat front wall 2, the inner annular wall does not extend back as far as does the outer or peripheral wall. Room is therefore provided for the dial to be nested within wall 2 without contacting the rear edge of wall 2*. A clamp "nited States Patent 0 4 is fixed in annulus 2 at the top of the casing and has a lip 4 projecting at the rear and bent down into overlapping relation to the glass dial.

Surrounding the inner annular wall 2 of the casing is a ring gear device stamped out of sheet metal, the same comprising the gear proper 5 and a tubular hub 5 This device rotates freely within the ringlike portion of the casing; the gear proper being provided with preipheral teeth 5 to mesh with complementary elements forming part of the driving mechanism in the base as is customary in this type of clock. Hub 5 is sufliciently long to bring the gear proper near the disc or dial 3 when the free end of the hub reaches to front wall 2. The side of the gear proper facing the dial is knurled, as shown at 5 in Fig. 4.

The minute hand 6 and the hour hand 7 are rotatable on a post 8 that is fixed to and projects forward from the center of the dial, with a small gear train 9 connecting them together so that the minute hand may drive the hour hand.

The minute hand is shown as being formed of sheet metal, trough-shaped and tapered so that the sides of the trough converge until they almost meet at the tip. This hand is not long enough to reach to the casing annulus 2. Fixed to the tip of the minute hand is a spring wire 10 that extends radially into the narrow space between the ring gear and the dial; the Wire being under stress so that it snaps into any valley in the knurling with which it may happen to register.

In the arrangement shown the wire is formed into a 2, one leg 10 being long and being bent to create an eye 10 near the base thereof. The other leg, 10 is much shorter than the first leg and, when free to do so, stands at an acute angle to the connecting bar 10 between the two legs of the Z. Leg 10*, a part of eye 10 and a part of bar 10 lie in the narrow space within the trough of the minute hand. Projecting from the sides of the trough, at eye 10*, are two ears 6 bent inwardly and passing through the eye to hold the wire in place.

In assembling the parts of the clock, leg 10 of the wire is slipped between the dial and the ring gear, preferably before the minute hand is mounted on the handsupport'ing post 8. Then, when the minute hand has been placed in working position, the wire will have been stressed until elements 10 and 10 stand at right angles to each other, as in Fig. 2, instead of being at an acute angle to each other as they are in Fig. 6. Consequently element or leg 10 is at all times yieldingly held against the knurled surface of the ring gear. This interlock between the ring gear and the wire is sufficient to insure that the minute hand will turn with the ring gear during normal operation of the clock, without danger of slippage that would cause the clock to be inaccurate. However, one may at any time grasp the minute hand and turn it to the right or left for setting the clock, with the wire simply riding over the ridges and valleys in the knurling in the manner of a pawl that is pulled backward over teeth with which it cooperates. Then, as soon as the minute hand is released it becomes operatively interlocked with the ring gear.

Although the ring gear is preferably knurled, it may have a plain face, provided that the wire is sutficiently stressed and the gear face is not too polished.

The graduations with which the clock hands cooperate may be placed on the glass disc 3 or on the clock case. *In the arrangement shown, there are markings 11 and 12 on the disc which, therefore, becomes the dial.

It will thus be seen that I have produced an extremely simple clock in which the means for applying the driving force to the minute hand is not readily apparent and in which the connecting piece between the minute hand and the ring gear constitutes an automatic clutch which releases under pressure applied to the minute hand and immediately locks again when such pressure ceases. The illusion of hands that drive themselves is of course dependent on the thickness of the wire and its color.

I claim:

1. A clock provided with a hollow annular casing, a ring gear in the hollow interior of the casing, a stationary disc secured to the back of the casing, clock hands mounted on the disc for rotation about the axis of the gear, a resilient wire secured to the tip of one of the hands and tensioned to press against the side of the gear with suflicient force to create a driving connection for that hand, and a driving connection between the hands to cause one of them to function as the minute hand and the other as the hour hand.

2. A clock as set forth in claim 1, wherein the side of the gear engaged by the Wire is knurled to provide valleys in which the wire may seat itself.

3. The improvement in .a clock mechanism wherein a ring gear acts directly on a clock hand to drive the same; which consists of a spring wire secured to the tip of said hand and extending as a continuation of the hand into contact with a side of said gear while under sulficient stress to cause the hand to turn with the gear; and the wire being such, in size and color, as to make its presence not readily apparent to an observer.

4. The improvement as set forth in claim 3 wherein the surface of the gear engaged by the wire is knurled.

5. A clock as set forth in claim 3, wherein the hand is trough-shaped in cross section, the wire having a portion lying in the trough and containing a loop, and wherein the hand is provided with a part that extends through the loop to anchor the wire to the hand.

6. A clock as set forth in claim 1, wherein the wire has a V-shaped outer end, one arm of which stands at right angles to the disc, the said portion being stressed in the assembly so that the second arm of said portion is parallel to the disc and lies behind and in contact with the ring gear.

References Cited in the file of this patent UNITED STATES PATENTS 1,768,100 Baum-garten June 24, 1930 1,905,783 Andersen Apr. 25, 1933 2,642,713 P-rins June 23, 1953

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