US2022715A - Electric clock - Google Patents

Description

Dec. 3, 1935. G GREENAMYER 2,022,715

ELECTRIC CLOCK Filed May lO, 1934 Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE 2,022,715 Emc'rnlc cLocx Application May 10,1934, serial No. 724,905

9 Claims.

'Ihis invention relates to electric clocks of the type drivenby self-starting synchronous motors and having the well known power interruption signal automatically operated and visible through 5 a window in the clock dial to indicate at a glance whether or not the clock has had uninterrupted operation.

In the past electric clocks have been equipped with a separate knob for resetting the signal from red-to white after resetting the clock to the correct time. In other words, two separate and distinct operations were required and the operator in resetting the clock not only had the bother of the additional operation f setting the signal, but was apt to forget to attend to it. Moreover, the reset means were usually arranged for operation from the back or bottom of the clock and were not convenient to manipulate. It is, therefore, the principal object of my invention to provide an electric clock in which the signal resetting means is combined with the time setting means for simultaneous operation preferably from the front of the clock, so that the operator has only one simple operation to perform and cannot leavel the clock in improper condition.

The invention is illustrated in the accompanying drawing, in which- Figure 1 is a view partly in side elevation and partly in vertical cross-section of an electric 30 clock embodying my invention;

Figs. 2 and 3 are fragmentary face views of the clock showing the signal in its normal position, showing White, and in its moved position, showing red to indicate power interruption;

Fig. 4 is a section on the linel 4-4 of Figure 1 showing the signal bob in full lines in its normal position for a white indication and in dotted lines in its turned position for a red indication;

Fig. 5 is a horizontal section on the broken line 5-5 of Figure 1 showing the signal resetting and time setting means in retracted inoperative position, and

Fig. 6 is a similar view showing theaforesaid means in operative position.

The same reference numerals are applied to corresponding parts throughout the views.

The invention is illustrated as applied to an electric clock for controlling the turning on and shutting off of gas to'a gas range, pipes being connected to a valve in the bottom of the clock case i0 at Il, and the valve means being automatically opened and closed at predetermined times in the operation of the clock, according to the setting of on and off knobs l2. However, it should be understood that the invention, while particularly advantageous when applied to a clock for a time controlled device, where positive setting of the clock is-most important, it is applicable to self-starting clocks generally.

Ihe clock has the usual dial I3 and cooperating 5 hands I4 turned with respect thereto by the clock train I5 in the operation ofthe electric motor i6. This motor is of the self-startingsynchronous type and, consequently, will start as soon as the clock is plugged into the line, and, l0 just as soon as electric service is resumed after power interruption. This clock is equipped with a signal disk Il visible through a window I8 in the dial, the signal being half white and half red and normally showing white, as indicated in 16 Fig. 2, but showing red as in Fig. 3, after a power interruption. The signal disk is mounted on the front end of a shaft I9 suitably received near its front end in a bearing 20 on the frame plate 2| of the clock and at its rear end in another bearzoY ing `22 in the back plate 23. The shaft I S carries a bob 24 of the shape shown in Fig. 4 which normally occupies the full line position so long as the current for the motor IB is not interrupted and there is a magnetic field to hold the bob 25 against turning by gravity to the dotted line position shown in Fig. 4. 'I'he bob is overwelghted suiliciently on one side so that when there is an interruption of the magnetic eld, the bob will turn in a clockwise direction from the full line position to the dotted line position. It is furthermore sufilciently overweighted on one side so that after it tur'ns to the dotted line position, it will not turn back by itself when the current is turned on again and the magnetic ileld is resumed. When the bob is in the full line position of Fig. 4-the normal position-the signal Il shows white as in Fig. 2, but when tne bob is turned to the dotted line position, the signal is turned with it to show red, as in Fig. 3.

In accordance with the present invention, I provide a reset knob 25 on the end of a stem 26 slidable in a hole in the frame plate 2|. A coiled compressionl spring 21 tends normally to urge the stem and knob inwardly so as to hold a time 45 set pinion 28 out of mesh with a time set gear 29 meshing with the clock train I5. The pinion is meshed with the gear by pulling out on knob 25 as in Fig. 6, whereupon the knob can be turned to turn the gear 29 to set the clock in the well 50 known way. A bar 30, disposed parallel with and above the shaft I9, is slidable lengthwise relative to the shaft in a hole 3| in the back plate 23. The bar has the front end thereof bent upwardly as at 32 to receive the headed inner end 33 of the 65 stem 2l, and in that way the bar slides' forwardly as the stem 26 is pulled out by means of knob 25. A cam 34 is formed on the bar 30 to engage a lug 35 on the signal bob 2.4 and move the bob from the dotted line position of Fig. 4 to the full line position in the forward movement of the bar 30. See Fig. 6.

In operation, when the operator finds the clock with the signal I1 showing red, as in Fig. 3, indicating that there hasbeen a power interruption and that the clock has accordingly been out of operation for an'equivalent length of time, he merely grasps the knob 25 and pulls it out to reset the clock. AIn pulling the knob out, the bar 30 is pulled forward simultaneously from the position vof Fig. to that of Fig. 6 and the cam 34 accordingly resets the signal I'I to show white, asin Fig. 2, by moving the bob 2l from the dotted line position of Fig. 4 back to the full line position. While theknob is pulled out the operator sets the clock for the correct time by turning the knob so as to rotate the time set gear 29 by means of pinion 28. anifestly, the operator cannot possibly omit t e resetting of the power interruption signal when Vhe is setting the clock for correct time; this other operation, by reason of the combination of the two means as herein disclosed, is made an incident of the operation of time setting.

'I'he appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

l. In a self-starting electric clock, .a time set Vvstem having a. knob whereby it is arranged to be pulled out and turned for time setting, a signal shaft parallel to said stem, a signal thereon arranged to have pivotal movement with the shaft as a center from a normal position to indicate an interruption of clock operation and the conse- -quent need for. time setting, and a swingable bob for turning said shaft which is gravity biased in one direction but normally maintained in a raised position magnetically while the clock is in operation whereby it moves by vgravity upon interruption of the clocks operation, and a cam har parallel .to said signal shaft and having a cam thereon arranged when pulled to engage and move said bob in the opposite direction to normal position, said bar being connected with said stem to be pulled therewith. f

2. A clock as set forth in claim 1 including spring means normally urging said stem to move to retracted position and serving also to move said cam bar with the stem to a retracted position.

3. In a selff-starting electric clock having a motor and comprising a rotatable time set gear, a power interruption signal shaft extending through the centerof said gear and carrying a signal on its forward end' visible on the clock face, a bob on the shaft magnetically balanced in the fleldof the motor in a normal position, a reciprocable androtatabletime set stem carrying a pinion movable endwise with the stem into mesh with the gear and rotatable with the stem to turn the gear, and a reciprocable cam bar parallel with said shaft and having a cam surface arranged to engage and turn said bob from an abnormal unbalanced to a normal balanced position, said bar having a portion connected with said stem so as to move endwise with the stem but allow turning of the stem relative thereto.

4. A clock as set forth in claim 3, including 5 spring means normally urging said stem to move to a retracted position.

5. In a. self-starting electric clock having a drive motor, a clock gear train driven thereby and hands operable by said train relative to a clock face, a signal shaft parallel to the gear and motor axes carrying a signal on its forward end visible on the clock face, a bob arranged to have pivotal movement with the shaft as a center and gravity biased to a certain position but normally held in another position magnetically balanced in the field of the motor, and a time set stem operable manually from the front of the clock in a direction parallel with the signal shaft, said stem having means operated thereby in the movement thereof incident to time setting to turn the signal shaft through a small angle, whereby to move the bob from its gravitated position to the magnetically balanced position.

6. In a self-starting electric clock having a drive motor, a clock gear train driven thereby and hands operable by lsaid train relative to a clock face, a signal shaft parallel to the gear and motor axes carrying a signal on its forward end visible on the clock face, a bob arranged to have pivotal movement with the shaft as a. center and gravity biased to a certain position but norm-ally Iheld in another position magnetically balanced in the field of the motor, a time set stem operable from the front of the clock endwise parallel with the signal ,shaft and carrying a pinion arranged in the endwise. movement to mesh with a gear of said train for time setting upon rotation of the stem, and cam means movable only endwise with said stem relative .to the bob so as to engage the same only when it is in its gra-vitated position,

said cam means being arranged to move the bob to the magnetically balanced position.

7. A clock as set forth in claim 5, including spring means normally urging said stem to return to initial position after manual operation.

8. A clock as set forth inclaim 6, including' spring means normally urging said stem to re'- turn to initial position after manual oper-ation.

9. In a self-starting electric clock having a drive motor, a clock gear train driven thereby and hands operable by said train rela-tive to a clock face, a signal shaft parallel to the gear and motor axes carrying a signal on its forward end' visible on the clock face, a bob arranged to 55 have pivotal movement with the shaft as a center 'and gravity biased to a certain position but normallyheld in another position magnetically balanced in the ileld of the motor, a time set stem having a manually operable knob in front 50 of the clock, means operatedA by said stem to cause resetting of the hands, andanother means operable by the stem in the setting operation to turn the signal shaft through a small angle, whereby to move thebob from its gravitated positlon to the magnetically balanced position.

GEORGE GREENAMYER.

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