US2777278A - Variable signal alarm clock - Google Patents

Description

Jan. 15, 1957 Filed July 8, 1953 H. JUNGHANS ETAL VARIABLE SIGNAL ALARM CLOCK 3 Sheets-Sheet 1 INVENTORS ATTORNEY Jan. 15, 1957 H, JUNGHANS ETAL 2,777,278

VARIABLE SIGNAL ALARM CLOCK Filed July 8, 1953 3 Sheets-Sheet 2 11 INVENT0R$ Q H ZmUZ IM- Buw-Za BY w I 2 .14 7 ATTORNEYJ United States Patent VARIABLE SIGNAL ALARM CLOCK Helmut Junghans and Kurt Biiuerle, Schramberg-Sulgen, Germany Application July 8, 1953, Serial No. 366,836

Claims priority, application Germany July 11, 1952 9 Claims. (Cl. 58-2112) The present invention relates to improved alarm clocks. There are alarm clocks known which are provided with a controlling system for the quality of the sound of the alarm in such a way that, after the alarm starting means have been tripped at the time of the desired alarm, the space of time in which the different strokes of the alarm hammer do occur is increased at the beginning of the alarm. It is possible to have such controlling systems controlled by the time mechanism of the alarm clock, but it is also possible that the said systems are driven by the driving spring system of the alarm mechanism.

There are further more alarm clocks known which are provided with means for initially damping the sound of the alarm which are usually provided with movable abutments which might be connected with the shaft of the spring which drives the alarm mechanism in such a way, that said abutments are moved out of the range of the swinging alarm hammer when the alarm spring has run down to a certain degree; in such a way that the alarm hammer which thus far had been prevented by the abutments to reach the alarm clock now can reach it; respectively the alarm hammer which initially did strike upon a damping cushion can get into metallic contact with the clock when the said abutments had been removed.

Such alarm sound controlling systems-though requiring a more complicated constructionhave the advantage that they first produce a signal of relatively short duration and then let follow a short pause of certain duration. Since the hammer does strike the sound producing element with full force, the volume of the produced sound is the same as produced by a normal continuously sound ringing alarm mechanism.

The damping means has the advantage that initially a low alarm sound can be produced, but has the disadvantage that such an alarm sound is a continuously given signal which, as experiences have shown, is considered to be annoying by many persons.

The present invention has for an object to combine the advantages of both these known alarm devices in such a way that controlling means are provided which in the beginning delay the periodicity of the strokes of the alarm hammer and apply a damping member at least in the beginning of the period of time during which the periodicity of the striking hammer is reduced. If the damping is performed during the whole time of reduced periodicity the single strokes of the alarm system do sound damped while the frequently repeated sounds of the alarm during the period of unreduced periodicity are undamped. If the damping is performed only at the beginning of the time of reduced periodicity during which single alarm strokes are produced, a triple alarm signal is obtained, viz. first damped single strokes then undamped single strokes and finally an undamped sequence of high periodicity. The said alarm ringing system is preferred and will be explained below in detail.

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Further object of the invention is an alarm sound controlling system consisting of a disk-like element provided with cams and controlling curve-shaped edges, said disk being driven by the shaft carrying the spring of the alarm mechanism in such a Way that the subsequent switching from damped single stroke alarm to undamped single stroke alarm and then to normal loud alarm sound is performed by said controlling disk. The corresponding means co-operating with the said controlling disk includes a lever journalled on the shaft of the escape lever of the alarm mechanism. An additional double arm lever, which is mounted oscillatably and can be shifted transversally to its aXle of oscillation is provided which is coupled with the said lever mounted on the shaft of the escape lever of the alarm mechanism as well as regards to rotation as to shifting. This double arm lever can be brought into engagement for a certain period of time against blocking cams mounted on an arbor which rotates at a higher speed than the minute wheel of the clock work, which engagement is created under the force of the driving spring of the alarm mechanism.

Further features of the invention concerning the construction of the different parts suitable for utmost simple form and presenting advantages as to manufacture and construction will be evident from the following description.

The drawings show the parts essential for understanding the co-operation of the clockwork and the alarm mechanisrn.

Fig. 1 is a rear view partly in section of an alarm clock provided with an alarm bell mounted on the rear face of the clock showing the first stage of ringing the alarm.

Fig. 2 is a view similar to Figure 1 showing the second stage of ringing the alarm.

Fig. 3 is a view similar to Fig. 1, showing the third stage of ringing the alarm.

Fig. 4 is a rear view of a modification of an alarm clock according to Fig. l in which the strokes of the alarm hammer actuate against the rear side. of the housing of the alarm clock.

Fig. 5 is a side elevation partly in section of the elements of Fig. 3 taken in the direction of the arrow A.

Fig. 6 is a top view of Fig. 4.

Figs. 7 and 8 are side views of two different elements.

In the alarm clock represented in the drawings of Figs. 1 to 3 the numerals represent the following parts:

1 the shaft of the spring driving the alarm mechanism; 2 the shaft of the escape lever of the alarm mechanism; 3 the escape lever of the alarm mechanism; 4 the escapement wheel of the alarm mechanism; 5 the handle of the hammer 6; 7 the clock mounted on the rear wall of the clock housing; 8 the alarm stopping means. Further details of the alarm mechanism are omitted, such parts being well known in all usual constructions.

Of the parts of the timework the following only are shown: 9 the shaft of the escapement wheel of the timework; 10 the escapement wheel of the same; a ratchet wheel 11, having four star-like ratchets, mounted on shaft 9.

The object of the invention is to control the operation of the alarm mechanism after it has been tripped by the time setting means in such a way that the strokes of the alarm ringing hammer first do occur in a damped manner and following each other at a comparatively slow rate, while later, provided that the alarm mechanism is not stopped, the strokes of the alarm striking hammer follows with high frequency at a high rate and undamped. This object is obtained as follows. The double arm lever 14 which in the following will be called controlling lever, is journalled on the shaft 1 of the driving spring of the alarm mechanism, which shaft can be provided with a groove for this purpose, said controlling lever being positioned between the plates 12 and. 13,. Fig. 5 just behind plate 12. The lever 14 is provided with an open, fork-like bearing 14a (Fig. 7) for the purpose of being able to be shifted transversely on arbor 1. The lever 14 is provided with a fork 14b, the opening of which willbe referred to as slot 14c. The long arm of lever 14 extends to curved'part 14d ending in a finger Me. A' spring 15 of hair-pin shape actuates by means of an eyelet 15a the shaft 1 and is attached by its other end prong inhole 14) in the lever 14-; the function of the spring 15"being that lever 14 is urged with its open bearing-14atowards shaft 1 of the alarmwork spring in such a way that the finger 14:: reaches into the range of the ratchets of the ratchet wheel 11.

For coupling the said controlling lever 14 with the shaft 2 of the escapement lever of the alarm mechanism a bent pin 16 is provided thereon; the vertical part 16:: ofthe said pin projecting through the slot 140 of the controlling lever 14. It will be described below how controlling lever 14 co-operates with the alarm ringing hammer and the timework in such a way as to obtain the desired control of the strokes of the alarm hammer.

A disk-like member 17, termed a cam disk hereafter, Fig. 8, is provided on the shaft 1 being coupled to the same by friction. Viewed from the side of the dial this cam disk is positioned behind the rear plate 12 of the frame of the clockwork. The cam disk 17 is provided with a cam 17a co-operating with a pin 18 mounted on the controlling lever 14 in such a way that after the alarm mechanism has run down to some extent the cam edge 17a engages pin 18 of the cam disk 17; thus the control lever 14 is shifted transversely to shaft 1 against the action of spring 15 such that finger 14e gets out of the range of the ratchets of ratchet wheel 11. In order to define the initial position of cam edge 17a an abutment member 17b is provided on the cam disk 17 such that the bent edge 17c engages with a non-moving part of the clock'for example with the edge 12a of the rear frame part 12.

The operationof the described mechanism is as follows: when the alarmwork has been tripped at the set time the shaft 2 of the escapement lever of the alarm mechanism is released.

Assuming that (see Fig. 1) the escape lever 3 has a'position relative to the escape wheel 4 that the escape wheel abuts against the pallet 3a in the direction of the arrow 19; Under such condition the handle 5 of the hammer, the hammer 6, pin 16, 16a are urged in the direction of the arrow 20 in such a way that pin 16a abuts against the prong 1412 and shifts the controlling lever 14 from the position indicated by the broken lines to the position shown by full lines until finger 142 engages with the oblique shoulder 11a of the nearest ratchet of the ratchet wheel 11. The controlling lever 14-will then be shifted in its open fork-like bearing 14a against the action of the hair-needle spring 15 transversely to axle 1 until its finger 145 will slide over the said. ratchet and will berotated further in clockwise direction until finally the pallet 3a becomes free of the escape wheel which causes return of rotation of the escape lever shaft 2.

When the oscillating movement of the hammer has reachedits greatest deflection the hammer will strike the bell 7 if certain other means which will be described later do not interfere.

Upon reversal of movement of shaft 2, i. e. when pallet 3a is out of engagement of the escape wheel4 and when pallet 3b (Fig. 2) is in engagement with the escape wheeltion of arrow 22 first is stopped. Pallet 3b therefore will be out of engagement of escape wheel 4 only after finger 14c co-operating with the above mentioned ratchet of the ratchet wheel has been tripped due to the fact that the said ratchet had been turned further in clockwise direction. The control lever 14 then swings further in the direction of arrow 23 thus pallet 3a is free of escape wheel 4;. pallet 3a then is driven again in the direction of arrow 19 and the whole cycle is repeated. The rate of time at which the alarm mechanism under such conditions is operated after having been tripped at the desired time by the action of the alarm tripping means is defined by the number of ratchets 11b of the shaft 9 of the escape wheel and the speed of rotation of the same.

Since the purpose of the so far described arrangement is to-give a starting alarm signal such that the alarm clock can be at once stopped by a person which is used to being easily awakened and to provide means for waking a person who is not so easily awakened without causing shock, further means are necessary for switching off the delaying mechanism after a certain number of single alarm strokes and then to ring the alarm mechanism at its usual rate. This is the purpose of the controlling cam 17a of the cam disk 17 the said cam disk being connected by friction with shaft 1 first is in its inoperative position since the bent edge 17c abuts again the frame plate 12a of the clockwork when the alarrnwork is wound .up, and in such position there is no engagement with pin 18 of the controlling lever 14. As the alarm mechanism commences to run (see Figs. 2 and 3) the cam edge 17a-engages pin 18 and shifts control lever 14 in its open bearing 14a in the direction of arrow 24 against the force of hair-pin spring 15 to such extent that finger 14:: moves out of the range of ratchet wheel 11. In this position control lever 14 still oscillates under the action of pin 16, 16a of hammer 6, the oscillating movement no longer being controlled in its rate of oscillation and therefore since the weight of lever 14 is very small the alarm mechanism runs at its normal speed.

The cam disk 14 according to the invention is furthermore constructed in such a way that it acts as a time controlled abutment for damping the strokes of the clock hammer. For this purpose the cam disk 17 is provided with an arm 17d which has a bent edge 17e extending approximately tangentially to axle 1. The function of this bent edge 17a is (Fig. l) to limit in the beginning of the alarm signal, when said signal is sounded by means of single alarm strokes, the lateral movements of pin 16 in the direction of arrow 25 so that hammer 6 does not actually hit bell 7 though pallet 3a is out of engagement with the escape wheel. The limiting edge 17e therefore causes the hammer 6 to perform so-called idle strokes until edge 17e finally moves out of the range of pin 16 due to the running down of the alarm mechanism. This condition is shown in Figure 2 whence one can realizethat pin 13 which first is positioned on the beginning of cam edge 17a so that lever 14 still is able to perform its controlling functions in co-operation with ratchet wheel 11 so that hammer 6 still strikes bell 7 with single strokes. While in the first stage of alarm only very weak idle single strokes are struck by the hammer, inthe second stage undamped strokes are executed upon the sound radiating member of the alarm clock. In the third stage of alarm the limiting action of the striking means in qualitative as in quantitative regards has been done away with due to the fact that the limiting edge 17c has been moved to an inoperative position suspending the time cont'rol of controlling lever 14, which results in a full volume and at normal rate signal.

It is desirable that the mechanisms of alarm clocks according" to the invention as described above should be installed without essential changes in clockhousings in:

by the alarm hammer. In order to accomplish this aim a half ring part 17 is provided on the cam disk 17 the edge face of which 17g is bent (see Figs. 4 and 7) such that the oscillations of the handle 105 of the bell hammer are limited. The handle of the bell hammer forms a knee 105a for this purpose which during the first stage of alarm actuates against the abutment 17g in such a way that the hammer 106 cannot reach the pin 107 which is riveted to the rear side of the clock housing.

In order to couple the control lever 14 with the shaft of the escape lever of the alarmwork a lever 108 is provided which is secured to the shaft 2, the said lever reaching with its bent end 108a into the slot 14c of the control lever.

It can be seen from Fig. 8 that the cam disk 17 in view of the fact that the extensions 17h and 17h are of yielding nature can be set upon the shaft of the alarm mechanism spring from the side, the resiliency being such that connection between shaft 1 and disk 17 is assured by means of friction. The disk 17 is positioned behind the rear frame plate which means the plate distant from the dial and it can he therefore mounted or taken or? solely by unscrewing the winding handle of the alarm clock.

It is usual that modern alarm clocks are equipped with stopping means by which in case the person to be awakened prematurely does awaken, the alarm mechanism can be shut off before it is tripped by the time mechanism. A certain type of shut off means makes use of the power of the alarm mechanism driving spring in order to interlock the shut off lever 50 (Fig. 4) with a shut off arm 51, the latter being mounted on the shaft 2 of the escape lever of the alarm mechanism. A curve 51a is provided for this purpose on a part of the shut off arm 51 against which the shut 0E lever 51 (Fig. 6) abuts with its edge 50a in such a way that by shut off arm 51, escape lever shaft 2, escape lever 3 of the alarm mechanism, escape wheel, and other suitably arranged parts of the driving system of the alarm mechanism is somewhat turned back against the force of the driving spring. The curve 51a extends into a part 51b against which the edge 50a of the switching off lever 50 abuts when the switching off movement is performed by pushing down shaft 52 of the shut off knob; the parts 50, 51 then remain interlocked by means of the force of the driving spring of the alarm mechanism. One can see from Fig. 4 that if the switch off lever 50, when being pushed down, transfers a backwards movement in counterclockwise direction to the shaft 2 the lever 108 Will also cause the controlling lever 14 to rotate in counterclockwise direction and would be inclined to tilt forcibly against a ratchet of ratchet wheel 11. In order to avoid such an eifect the shut oif lever 50 and shut olf lever 51 are so arranged and constructed that in switching off the shaft 2 of the escape lever of the alarm mechanism is pushed back in clockwise direction in such a way that lever 14 is lifted from the ratchet wheel 11 in counterclockwise direction to the direction of interlocking.

While the ratchet wheel has been shown mounted on the shaft of the escape wheel of the time mechanism it also is possible to mount this ratchet wheel on the shaft of the seconds wheel; but in such a case the number of teeth should be greater in order to obtain the same rate of strokes which in some regards is a disadvantage as it would be necessary that the depth of interlocking of the control lever and the teeth of the ratchet wheel would have to be less and the reliability therefore also would be decreased. It is preferable to have four to seven ratchets on the ratchet wheel. The arrangement of the ratchet wheel on the shaft of the escape wheel is preferred also for the reason that in such a case the lever arm of control lever 14 can be made longer which would be possible if the said lever arm should operate against the shaft of the seconds wheel.

In order to increase the distance of time of the single strokes 2 or more controlling fingers could be arranged instead of the 1 finger Me on the end of control lever 14 in such a way that these controlling fingers act like teeth of a rack with the ratchet wheel 11 and become interlocked subsequently to each other, until finally, the last finger of control lever 14 is released. The control lever 14 has been shown to be journalled by the shaft 1 of the driving spring of the alarm mechanism by reason of utmost simple construction; but apparently this lever could also be journalled by a special pivoting bolt especially if the control lever does co-operate with a ratchet wheel journalled by the shaft of the seconds Wheel so that thereby an essentially long lever arm can be obtained.

The described control system for the single stroke mechanism is controlled by the time mechanism of the alarm clock and the damping mechanism is controlled by the driving system of the alarm mechanism, but it is evident that this way of driving can be reversed and that it is also possible to control both control systems either from the timework of the alarm clock or from the alarm mechanism of the same.

We claim:

1. In a spring motor alarm clock, sound producing, setting and controlling mechanism comprising a shaft, a hammer lever-arm mounted to oscillate with the shaft, a control lever with a pin mounted to oscillate on the alarm spring shaft of the clock, said control lever having a slot for receiving the alarm spring shaft and shiftable in its longitudinal direction by means of said slot in the lever, said hammer lever-arm having a bent portion in the form of a pin, a ratchet wheel mounted on a shaft of the escapement wheel of the clockwork, said control lever having an elongated arm portion terminating in a finger adapted to contact and cooperate with the ratchet wheel whereby the ratchet wheel will stop the control lever and a second arm portion for cooperation with the hammer lever-arm, a spring connected to the control lever to urge the later into contact with the ratchet wheel a distance controlled by the depth of the slot, said control lever when first actuated being controlled by the ratchet wheel for temporary engagement, and a cam disk mounted on the alarm spring shaft and cooperating with the pin of the control lever to shift the control lever away from the ratchet wheel to provide a more rapid operation of the hammer lever-arm.

2. In a spring motor alarm clock according to claim 1 characterized in that the cam disk is provided with a resilient hub which is formed by two extensions open to the side, in such a way that it can be mounted on its shaft by friction.

3. In a spring motor alarm clock according to claim 1 in which the cam disk is provided with an abutment for abutting with a frame part of the alarm clock in order to define the initial position of the disk.

4. In a spring motor alarm clock according to claim 1 characterized in that the cam disk for shifting the control lever is frictionally mounted on the alarm spring shaft.

5. In a spring motor alarm clock according to claim 1, in which the part which has to by struck by the hammer is a part of the rear Wall of the clock housing.

6. In a spring motor alarm clock, sound producing, setting and controlling mechanism comprising a shaft, a hammer lever-arm mounted to oscillate with the shaft, a control lever with a pin mounted to oscillate on the alarm spring shaft of the clock, said control lever having a slot for receiving the alarm spring shaft and shiftable in its longitudinal directions by means of said slot, said hammer lever-arm having a bent portion in the form of a pin, a ratchet wheel mounted on a shaft of the escapement wheel of the clockwork, said control lever having an elongated arm portion terminating in a finger adapted to contact and cooperate with the ratchet Wheel whereby the ratchet wheel will stop the control lever and a second arm portion for cooperation with the hammer leverarm, a spring connected to the control lever to urge the latter into'contact with the ratchet wheel a distance controlled by the depthvof theslot, said control lever when first actuated being controlled by the ratchet wheel for temporary engagement, a cam disc mounted on the alarm spring shaft and cooperating withv the pin of the control lever to shift the control lever away from the ratchet Wheel to provide a more rapid operation of the hammer lever-arm, the slot of the control lever being an open bearing, said control lever spring being hairpin shaped, bearing on one end against said last-mentioned shaft and on the other end against the control lever, so that the latter by the force of said last-mentioned spring bears with the closed" side of the bearing against the alarm spring shaft and is pushed in the direction of the ratchet Wheel.

7. In a spring motor alarm clock according to claim 1, in which an abutment is provided on the cam disc to engage the pin on the hammer lever-arm during its movement to thereby damp the hammer strokes at the beginningof the alarm signal.

8. In a springmotor alarm'clock according to claim 1, in which the cam disc is frictionally mounted on its shaft and'is provided With a curved edge controlling the back movement of the control lever.

9. In a spring motor alarm clock according to claim 1, in which the ratchets of the ratchet wheel are provided with radially extending abutting steep shoulders and oblique sliding surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 983-,672 Boyce Feb. 7, 1911 1,691,081 Pierce Nov. 13, 1928 2,086,785 Thomas July 13, 1937 FOREIGN PATENTS 1,029,587 France Mar. 11, 1953

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