US3541776A - Electric mechanism for sounding the alarm of a clock at a preset time - Google Patents

Description

Nov. 24, 1970 w. GANTER 3,541,776

ELECTRIC MECHANISM FOR SOUNDING THE ALARM OF A CLOCK AT A PRESET TIME Filed July 15, i968 4 Sheets-Sheet 1 m "g 1:7 2 an at Q: d

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. ELECTRIC MECHANISM FOR SOUNDING THE ALARM OF A CLOCK AT A PRESET TIME Filed July 15, 1968 4 Sheets-Sheet 2 New. 24, 1970 w GANTER 3,541,776

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ELECTRIC MECHANISM FOR SOUNDING THE ALARM OF A CLOCK AT A PRESET TIME Filed July 15. 1968 4 Sheets-Sheet 4 United States Patent US. CI. 58-49 7 Claims ABSTRACT OF THE DISCLOSURE A single cycle alarm mechanism is briefly actuated at a preset time by a clock gearwheel by means of a rotating shaft operated through a desired angle and detented until release for an additional cycle by the clock timing mecha nism. The load on the clock mechanism is present only during the time the alarm is being actuated.

This invention relates to alarm clocks, especially battery operated clocks customarily having a reset alarm mechanism in which at least one wheel moves electric contacts for completing and releasing an alarm energizing circuit.

If the stop is not operated on a spring wound clock, the alarm lasts for a period until the spring storage device is exhausted. Furthermore, an electric alarm clock may ring during a thirty to forty-five minute period until the alarm mechanism is released, unless the shut off regulator is actuated.

This invention stems from a known clock mechanism equipped with a camshaft carrying an operating lever, which in combination with movement of an ordinary mechanical release mechanism and with an alarm release set for predetermined timing. The operating lever includes a toothed wheel with an extended cam portion coupled to close a movable switching contact spring with a fixed contact as the lever moves through a single cycle between two operating limits, to thereby operate the alarm, lock it, and conversely to release the alarm mechanism with normal clock movement as the cam turns over its prescribed angle.

The invention is concerned with the basic problem of the ringing device, that is the construction of the mechanism for the alarm, when there is a cam actuating arm operated only during a preset period until the cam ad'- vances to an unoperated position, so that during the alarm period after the alarm is actuated, the load on the gear train caused by cam contact is removed.

A feature of this invention is the movement by a clock mechanism of a pivot arm which has alarm sounding means at a position on the end of the arm so that it is coupled to the clockwork gears only during alarm and swings through a single cycle to a detent position out of contact with the drive means. The guided arm is mounted to move outside the working region of the clock gear train and its cam surface contact can no longer rub to load the clock mechanism when the alarm is not being sounded.

To the other features of the invention a holding magnet may be added which detents the operating arm located on the camshaft after moving through a working angle where an electrical contact set is operated by the movable arm. If as is of itself known, a camshaft is mounted parallel or coaxial with an alarm actuating shaft now in accordance with the invention is provided with an extending drive arm and a further axial camming movement in order to mesh the camshaft drive arm into hobnails or the like extending from a clockwork wheel; a

permanent magnet also may be used as a detent magnet to hold a detent part on an arm driven from the camshaft to hold it away from the drive position as the drive arm rotates out of mesh.

The invention also permits, in the manner described, for the camshaft to be tilted by means of an elongation thereon rather than axially cammed in order to swing out of the clock driven position. An alarm timing spring may operate to tilt the camshaft so that a toothed segment thereon located on an extending detent arm will be moved and detented by a magnet positioned on a straight line drawn between the axes of the clock drive wheel and the camshaft.

In one such embodiment a feature of the invention moves the camshaft from its limiting angular position by a return spring such as a spiral spring, which also serves to return the shaft to a parallel position with the necessary clockwork.

Another example of the invention resides in replacing a latch magnet with a mechanical device, in which the camshaft latching arm is turned with a contact bearing arm to a position where a latching spring detent is located and the camshaft is unmeshed from the clockwork drive arrangement until the selected time of the clockwork returns the camshaft to the meshed position.

Further objects and examples of the invention follow from the following description and examples which are shown in the drawings and specification.

In the drawings:

FIG. 1 is a plan view through section II of FIG. 2 of the mechanism for setting the alarm time limits in its ready to ring position, with omission of the clockwork drive elements unnecessary to an understanding of the invention;

FIG. 2 is an elevation view of FIG. 1 through section IIII illustrating with a phantom view the alarm engagement mechanism positions;

FIGS. 3 and 4 are a mechanism similar to FIGS. 1 and 2 with sections III-III and IV-IV respectively taken through the figures to illustrate the operation at the end of the awakening in the turned oif position;

FIG. 5 is a second embodiment with a detented contact cam lever in plan view as taken through section VV through FIG. 6, illustrating with phantom view the positions of operation through the end of the awakening;

FIG. 6 is an elevation view through section VI-Vl of FIG. 5 in a similar operating position as FIG. 5;

FIG. 7 is a partial view of the contact operating mechanism taken through section VII-VII of FIG. 6;

FIG. 8 corresponds to the display in FIG. 6 illustrating the disengaged position of the alarm engagement mechanism;

FIG. 9 shows a partial plan view taken through section IX-IX in FIG. 8;

FIGS. 10 and 11 are a third embodiment in plan view illustrating a first variation of the mechanically operable detent mechanism in positions near the end of the ringing period; and

FIGS. 12 and 13 are a second variation of the third embodiment in similar relationship as FIGS. 10 and 11.

Considering first the embodiments of FIGS. 1 through 4, 10 and 11 show two frame members of the clock mechanism. Built upon the frame member 11 is a conventional alarm drive mechanism including a timewheel 12 with catch tab 12a and alarm dial wheel 13, which is furnished with an aperture to catch tab 12a at the set position for operating the alarm on the side opposite the alarm actuating spring 14.

Between the frame members 10 and 11 is journalled shaft 150, which carries hobnail wheel 15, and receives its drive by way of gear 15b from clockwork not necessary to show on the drawing to clarify this invention.

Parallel to the shaft a is journalled in a time operated position the camshaft 16, whose elongated pins 16a and 16b are journalled for axial movement. The camshaft 16 carries a cam actuating arm 160, which by way of an extending lobe 160' can be brought into contact with the hobnails of wheel 15. The pivotable cam actuating arm 160 is an elongated single piece with a handle piece 16d attached to one end and a tabbed end 16d at the other end to hold it against frame member 10 by the permanent holding magnet 17 aflixed thereto when the tab is moved near it.

The camshaft 16 also carries a contact operating cam surface arm 16e whose function is to operate the alarm contact set 18 when in the proper position. A bell 19 is connected from contacts 18 with battery through a manually operated switch 21, which permits the alarm to be shut off. On contact spring 18a, a sloping tongue 18a is carried. It engages teeth surface 16e on the contact operating cam surface 16e asthey come together so that the single teeth operate as cams to close contact set 18 and to let the contact operating tongue 18a to open in the spaces between teeth.

This mechanical construction provides the so-called repeating action interrupting the alarm signal. The three pointed teeth on the teeth surface 16e give short signals, while the last wide tooth a longer continued signal. The main signal lasts over a period of about twenty to thirty seconds.

In the ready to operate position of FIGS. 1 and 2, the cam surface arm 16e lies against a stop post 22 by force of the return spring 23 attached to cylinder 23a of the camshaft 16 at one end and held on the other end by a clamp 24 on the frame member 11.

It is seen also from FIGS. 2 and 4 that the spiral spring 23 in the ready to operate position when pushed moves vertically to its spiral plane, as adjusted with camshaft 16 under pressure of the alarm actuating spring 14.

The holding magnet 17 and the holding arm 16d, hold in place the cam shaft 16 and its cam arm parts 16c/16c at the end of the alarm period after the contact spring 18a glides over the last broad tooth on the contact cam arm 16e so that the cam tab 16c lies outside the influence of hobnails of the clockwork by contact of cam arm 160 with the hobnails.

The mechanism afforded by this invention operates in the following manner: At the beginning of the alarm period (FIGS. 1 and 2) the parts 12, 13, 14 and 16 are in ready to operate position, that is the detented tongue 12a rests on the part of the alarm mechanism 13 and upon wheel 12 (FIG. 2) so that the alarm actuating spring 14 is in its raised position. This raises camshaft 16 so that the camshaft arm 16c and the tab 16c clear the points of the hobnails on the clockwork wheel 15. The return spring 23 returns the contact cam arm 16e on the camshaft 16 against the stop 22 to a position in which the first tooth of the tooth surface 16e (FIG. 1) stands ready to move against contact spring 18a. Also, the holding arm 16a! is removed from the influence of holding magnet 17 so that the return influence of spring 23 on the camshaft 16 is not overcome.

At the start of the alarm period the alarm tab 12a falls in opening 13a in the alarm conditioning wheel 13 under the time wheel 12 to shove the alarm actuating spring 14 and the camshaft 16 with the action of spiral return spring 23 moves (FIG. 4) until the cylinder shoulder 16 on the camshaft contacts the frame member 11. During this forced movement, the cam tab 160' on camshaft 16 drops into operating position between hobnails on clockwork wheel 15, and with its turning in the direction of the arrow, the hobnails turn the camshaft 16 by cam arm 16c through a predetermined angle that is large enough to permit the toothed surface 16e on cam contact arm 16e to pass across the contact spring 18a. As the contacts perform their duty with the brushing of the spring 18a on the edge of the last broad tooth of contact cam arm 16e, the cam tab 16c is released from the engagement with a hobnail in such a position that the detent part 16d of the holding arm 16d is near enough to be attracted to holding magnet 17. In this limiting position of camshaft 16 the cam tab 16c is moved outside the turning range of the hobnails so that the undesirable loading contact is no longer a problem.

Accordingly, the signal period ends and is cleared so that after termination of the signal period of about thirty seconds initiated by the alarm actuating mechanism 12/13 no other takes place. However, much more time is needed, such as a time period of thirty to forty-five minutes. Until the expiration of this time the camshaft remains in the position of FIGS. 3 and 4. Only with the positioning of the timewheel 12 in the ready for alarm position of FIG. 2 is the camshaft 16 again axially shoved by the alarm actuating spring 14. With this action the detent part 16d of the holding arm moves over the face of the permanent magnet 17 and as soon as the magnet and detent are moved out of the influencing position the return spring 23 may return the camshaft into its starting position (FIG. 1), so that contact arm 16e rests at stop post 22. This return cycle can only be accomplished in the next alarm position.

It has been discovered that it is not necessary to contact the detent tab 16d against the holding magnet 17. A small air space can intervene, to permit putting a spacer on the detent tab 16d such as used to reduce noise on impact.

Also, this invention makes it possible to make in one piece the arm 16c, 16d, 16e of the camshaft 16 for example by stamping and bending sheet metal. The holding magnet 17 can also be mounted on detent arm 16d, or cooperating magnets can be on both detent pieces. The spiral return spring 23 may be replaced by a simple leaf spring which permits camshaft 16 to attain both an axial and rotary movement. Also, the spring forced movement can be replaced by gravity operated means or magnetic devices to perform the necessary axial displacement as well as the return swing. Replacement of hobnail wheel 15 with an equivalent wheel with magnetic or electric cam means or the camshaft may be geared by a Geneva movement or the like for operation by the clockwork gear 15. One such gearwheel could be the sweep wheel, second wheel or some other convenient driven element of the clockwork. Also, the camshaft 16 could be positioned axially by the timewheel 12 by moving the camshaft nearer the dial works. In some cases the alarm actuating spring 14 between the timewheel 12 and frame member 11 could be replaced by an electrically operated spring, such as a bimetallic member. In any case, the actuating spring 14 may be strong enough to overcome the axial force of the spiral spring 23 in order to remove detent tab 16d from the permanent magnet 17. After the actuation of timewheel 12 at the alarm time, the spiral spring 23 must be brought into position so that the camshaft 16 with cam arm 160 is in gripping engagement with the hobnail wheel 15. Furthermore, the spiral spring 23 should provide such a turning movement to the camshaft 16, that it is returned to the starting position (FIGS. 1 and 2) after the retention by detent arm 16d on holding magnet 17 is overcome.

The contact cam arm 16e and contact set 18 can also be modified, so that part 162 is a wiping electrical contact moving over an insulating plate with separated contacts.

The second embodiment (FIGS. 5 through 9) is distinguished from the first in that the camshaft is not axially moved but is tilted. Similar parts in the first embodiment are cross-referenced for comparison and the description is not repeated. In place of the hobnail wheel 15 is a rotating toothed gear 50. The camshaft 51 meshes therewith, and is mounted in frame members '52 and 53 to both rotate and tilt. For this purpose an elongated peg 51a is journalled in a slit in the frame member 53, with the slit orientation lying on a straight line from the axes of the clockwork gearwheel 50 and the shaft 51. The upper journal 52a for the camshaft 51 is fashioned to let shaft 51 tilt. The shaft 51 carries a cam member 51a with gear teeth 51a which mesh with teeth on gearwheel 50, as heretofore described, and a contact arm 51b with spaced teeth 51b on the lower surface, and finally a detent arm 510, which in detented position is held near permanent magnet 54. This is located, as the slit 53a in frame member 53, and a straight line drawn through the axes of gearwheel 50 and camshaft '51. The contact teeth 51b on the contact arm 51b are constructed for this purpose with crown like teeth and coact with the slope of tongue 18a carried on contact spring 1 8a.

This apparatus operates in such a way that by tilting the teeth are removed from the contact spring tongue 1*8a'. In the normal operation of the alarm cam, the simple teeth of the first embodiment could serve this purpose. However, by provision of the points in the preceding contact cycle, when the contact spring tongue 18a contacts teeth 16c (FIGS. 1 through 4), it might happen that the cogs would bind with the spring tongue.

The camshaft 51 also is operated by a return spiral spring 55 with its inner end alfixed to the camshaft and the outer end to the frame member 53. The spring 55 is so proportioned that it conforms with the camshaft movement in each position (FIGS. 8 and 9) with the shaft in its tilted position (FIG. 8) and its return to its working position (FIGS. 5 and 6).

In order to move the camshaft from its limiting position as in ready position (FIG. 8) to its working position (FIG. 6), an alarm conditioning spring 57 is provided with a ramp 57a. This contacts pin 51a of the camshaft so that in ready position the ramp 57a pushes against the camshaft 51 to force the return spring 55 into a tilted position. In this position the camshaft arm teeth 51a are not in mesh with the clockwork gear wheel 50, and the contact teeth 51b are removed from their working position against contact spring tongue 18a. Also, the detent part 51c on holding arm 510 is removedfrom the holding field of holding magnet 54.

Operation of this example is as follows: In the ready position (FIGS. 8 and 9), the alarm actuating spring 57 is held on alarm conditioning wheel 13 by time wheel 12 so that the ramp 57a tilts the camshaft 51 by contact with its elongated pin 51a. with its members out of contact with the intermediate gearwork wheel '50 and the contacts 18. Also, the detent arm 51c is held out of the holding power of magnet 54. When the alarm conditioning tab 12a falls into the apertured alarm position wheel 13 (FIG. 6), which moves the alarm actuating spring 57a far enough away from the camshaft 51 that it by force of the return spring 55 assumes a parallel position (FIG. 6) to the shaft of the gearwork wheel 50. Therefore, the camshaft teeth 51a mesh with the gear wheel 50 (FIGS. 5 and 6), and at the same time the first tooth of the camshaft contact surface 51b is positioned to operate contact spring tab 18a as illustrated in phantom positions of FIGS. 5 and 7.

Gear wheel 50 drives camshaft 51, as shown in FIG. 5 in phantom and full line views, so that contact set 18 is intermittently operated until the last broad tooth passes over contact spring tongue 18a. This places detent arm 51c close enough to the holding magnet 54, which is strong enough to hold the detent arm in detented position,

6 so that the camshaft makes a single such cycle (FIG. 5) to remove the camshaft teeth 51a out of driving influence from the teeth of the gearwheel 50.

At a time after the alarm, when the alarm actuating mechanism 12, 12a, 13 and 57 again return to their inactivated position, the alarm conditioning spring ramp 57a rests on the camshaft end 51a and removes the camshaft 51 from influence of the magnetic detent works 54/51c, 510' to return the mechanism to its ready position (FIG. 8).

As shown in FIGS. 10 and 11 the detent mechanism holding the camshaft in position after the end of its single movement comprises a ramp b on the switch operating cam arm 10012 which engages contact spring tab 18a. In FIGS. 12 and 13 a separate leaf spring 151 engages detent tab I carried about camshaft 100 for the same purpose.

What is claimed is:

1. Apparatus coupled with a clock mechanism for sounding an alarm when directed by an alarm conditioning mechanism at a preset time by electrical means, comprising in combination, a rotating shaft which moves in cooperation with said alarm conditioning mechanism and carries an actuating arm, means including a clockwork wheel operable with said shaft to initiate a single movement between limits defining a predetermined angle in response to said alarm conditioning mechanism, a contact set operated to sound an alarm as the shaft traverses said angle, means holding the shaft after said single movement in a position out of frictional contact with said clockwork wheel and means operable by said clock mechanism releasing and returning the shaft to a starting position where a further movement will be initiated by said alarm conditioning mechanism.

2. Apparatus as defined by claim 1, wherein said means holding the shaft comprises a holding magnet and detent means on said shaft positioned to come under the influence of the field of the magnet at the limiting position at the end of said movement.

3. Apparatus as defined by claim 1, with said shaft journalled for tilting movement to move it into and out of driving engagement with said clockwork wheel.

4. Apparatus as defined by claim 3, wherein said shaft is tilted along a straight line drawn between the axes of said clockwork wheel and said shaft.

5. Apparatus as defined by claim 2, wherein the magnet is located along a straight line drawn between the axes of said clockwork wheel and said shaft.

6. Apparatus as defined by claim 1, wherein said means returning the shaft comprises a spiral spring operable to bias the shaft in both a rotary and an axial direction.

7. Apparatus as defined in claim 3, wherein the means holding the shaft after said movement comprises a leaf spring and detent structure coupled for rotation with said shaft.

References Cited UNITED STATES PATENTS 3,166,887 1/1965 Jaccard 58-18 FOREIGN PATENTS 86,239 1965 France. 407,8 86 1966 Switzerland.

RICHARD B. WILKINSON, Primary Examiner J. F. GONZALES, Assistant Examiner

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