US2696072A - Alarm clock - Google Patents

Description

7, 5 R. R. LAWSON arm. 2,696,072

ALARM CLOCK Filed Aug. 9, i951 INVENTOR. ROBERT R. LAWSON BOBBY L. MC KIE waczmi.

ATTORNEY United States Patent ALARM CLOCK Robert R. Lawson, Somerset, Wis, and Bobby L McKie,

Elgin, Ill., assignors to The George W. Borg Corporation, Chicago, [1]., a corporation of Delaware Application August 9, 1951, Serial No. 241,106

6 Claims. (Cl. 58-21.12)

The present invention relates in general to alarm clocks and the object of the invention is a new and improved alarm mechanism for a clock of this character.

A feature of the invention is a governor for the alarm train which also functions as a striking device for sounding the alarm.

A further feature is a novel programming mechanism which becomes effective after the alarm has been set off to control the length and spacing of the rings in a desired manner.

The foregoing and other features will be explained more fully hereinafter, reference being had to the accompanying drawings, in which Fig. 1 is a side view of an alarm clock embodying the invention, with the case and bell in section so as to expose'the movement;

Fig. 2 is a partial section on the line -2-2, Fig. 1;

Fig. 3 is a sectional view similar to Fig. 2, but shows the alarm in operation; and

Fig. 4 is a cross section through the governor on the line 44, Fig. 3.

Referring to the drawing, the clock movement has a frame which comprises the back plate 10, the center plate 11, and the front plate 12. These platesare-held together in spaced relation by the usual pillar construction as shown in Fig. 1. There are two sectional pillars 1.4 and 15, a pillar 16 connecting plateslt] and'12 but partly cut away in Fig. 1 to'avoid obscuring other parts, and another sectional pillar in line with pillar 16 to the rear which connects plates 10, 11, and 12 and which has been omitted entirely. The frame also includes a bridge member 13 which is supported on pillars 14 and 15.

The reference character 18 indicates a generally cup shaped casing in which the clock movement is assembled by means of three studs 19, 20 and 21'which are fixed to the back plate of the movement frame and extend through holes in the bottom of the casing. These three studs are shown in Fig. 2, and the details of the stud 19 are shown in Fig. 1. A rubber grommet22 is preferably provided at'the opening in the casing and iscompressed between the base of the stud and a washer by the nut 23. This grommet insulates the casing against the transmission of noise from the clock movement; The studs and 21 are connected to the bottom of the easing 18 in the same way but are not shown in Fig. 1.

The casing 18 is closed in front by the dial 25 and the concave crystal 26. The latter is held in position in the usual. manner by the bezel 27. These parts are conventional andrequire no explanation.

The clock has an alarm gong or hell, indicated at 28, which encloses the back of the casing 18 and is secured thereto by means of three short posts such as 29 and 30; Fig. 1. These posts are secured to casing 18 by riveting or staking and the bell 28 is removably mounted on the posts by screws such as 31. and 32. The reference character 74 indicates a so-called anvil comprising a steel pin securely riveted or otherwise attached to the bell and having its free end extending through an opening in the casing 18 to a point whereit can be operatively engaged by the striking mechanism, as will be explained subsequently.

The main spring winding shaft is indicated at 33 and has bearings in frame plates 10 and 12. The shaft is turned by a key 34, only part of which is shown in the drawing. The spring barrel 35 and the associatedgear 36, which may be integrally formed, are rotatably mount ed on the shaft 33 by means of the sleeve or hub 37 v which is attached'to gear 36 in any suitable manner. Inside the spring barrel the shaft 33 is effectively enlarged by a cylindrical spring attaching member 38 which surrounds the shaft and is fixed thereto. One end of the main spring (not shown) is secured to the member 38 while the other end is attached to the spring barrel 35 in the usual manner. The spring is tensioned or wound by rotation of the key 34 in a clockwise direction, as seen from the back of the clock. as will be explained more fully hereinafter.

The member 38 has a short section of reduced diameter just below the spring barrel on which the gear 39 is rotatablymounted. Between the gear 39 and the frame plate 10 there is an assembly comprising the ratchet wheel 40 and the gear 42. The ratchet wheel 40 is provided with a hub 41 to which the gear 42 is rigidly secured and the hub 41 is fixed on the shaft 33, so that the ratchet wheel 4-0, its hub 41, and the gear wheel 42 rotate with shaft 33. A pawl 43 is mounted on the gear 39 and cooperates with ratchet wheel 49 to rotate gear 39 when the shaft 33 and ratchet wheel 40 rotate in a counterclockwise direction as seen from the back of the clock.

When the main spring is in wound condition it supplies power to rotate the gear 36 and the gear 39 in opposite directions. The gear 36 drives the time train, which has not been shown since it is not involved in the invention. The gear 39 drives the alarm train, which is shown and will be described presently.

The reference character 45 indicates the center shaft. This shaft has bearings in the plate 12 and in a small bracket (not shown beneath the plate and carries the minute hand 46. The center shaft is driven from the time train by means of a friction clutch in known manner, the driving connection being omitted since it is of the usual form. The gear 49 is mounted on a sleeve which is rotatable and also slidable to a limited extent on the center shaft and carries the hour hand 47. The gear 49 is driven from the center shaft by the usual speed reducing gears (not shown). The alarm set gear 51 is mounted on the sleeve 52 which is rotatable on the hour hard sleeve and also has a bearing in the bridge 13. The alarm set hand is indicated at 4-8 and is mounted on the sleeve 52. The hands 4-6, 47, and 48 are in front of the dial 25 as shown in Fig. l and cooperate with the dial inknown manner.

The alarm release spring is indicated at 53. This spring lies on top of the frame plate 12 to which it is secured by rivets as shown in the drawing and is tensioned upward to bear against the hub'of gear 49. The spring has an opening at this point through which the center shaft 45 passes freely. The gear 49 normally holds the spring 43 depressed as shown, the gear having an integrally formed member 50 which bears against the side of the alarm set gear 51. The gear 51 has an opening into which the member 50 can pass whenever the angular position of the said member is brought into coincidence with the opening by rotation of the gear during running of the clock, thereby allowing the gear 49 to move toward gear 51. and release the spring 53. This arrangement is generally similar to known alarm release mechanisms.

The position of gear 51 is indicated by the alarm set hand 48, mounted on sleeve 52, and is adjusted by means of the knob 56 on shaft 55. This shaft has bearings in the frame plates and carries a pinion 54 which is in mesh with gear 51.

The alarm governor includes an arbor or shaft 57 which has bearings in the frame plates 11 and 12 and has an integrally formed pinion 58, as shown in Fig. 4. The cross member 59 has a press fit on the shaft against a shoulder formed at the lower end of the pinion and is further secured by staking. The two fly weights 62 and 63 are supported on the cross member 59 by means of pivots 60 and 61, respectively.

Beneath the cross member 59 and between the fly Weights 62 and 63 there is a drum 64. A lever 67 is disposed beneath the frame plate 11 to which it is secured by the shoulder pivot This pivot passes through a hole in lever 67 and is riveted to the frame plate 11. The drum 64 is supported on the lever 67 by means of two depending ears 65 66 which pass through openings in the frame plate 11 and are secured to the lever 67 by riveting, as clearly shown in Fig. 4.

The fly weights 62 and 63 have integrally formed brake members 70 and 71 adjacent their pivots which engage the surface of the drum 64 with a certain pressure when the governor shaft 57 is in rotation, due to centrifugal force action on the fly weights. At their opposite ends the fly weights are formed with curved or rounded strikers 72 and 73 which are adapted to impact the anvil 74 on the bell 28 during rotation of the shaft 57. The drum 64 has two positions, however, shown in Figs. 2 and 3, respectively, in only one of which, the Fig. 3 position, is the anvil 74 impacted by the strikers. The drum is moved from one position to the other by rotation of the lever 67 on its pivot 68.

In order to control the movement of the lever 67 above referred to, it is provided with an integrally formed downwardly extending part 75 the extremity of which forms a cam follower 76 engaging the programming cam 77. A spring 78 is wrapped around the pillar 14 and has one end hooked over the edge of frame plate 11. The other end of the spring bears against the part 75 and causes the follower 76 to press against the cam 77. p

The programming cam 77 and the gear 79 are fixed together and are rotatably mounted on a short upwardly projecting stud 80 which is fixed to the frame plate 10. A washer 81 is provided on the stud 80 above the cam 77 and is retained in position by upsetting the end of the stud. The cam 77 is provided with an upwardly extending pin 82 which rests against the flat spring 83 when the cam is in the position in which it is shown in Fig. 2. This spring is mounted on a bracket 84 which is secured to the frame plate in any suitable manner.

The programming cam 77 has an operative contour consisting of alternating depressions and raised portions which cooperate with the spring 78 to operate the lever 67 and shift the drum 64 between its Fig. 2 and Fig. 3 positions. The raised portions, which sound the alarm, may be short or long and are separated by depressions varying in length, all depending on the type of alarm desired. The gear 79 has a wide tooth 85 and an adjacent blank or toothless section 86 the function of which will be explained presently.

The alarm train through which the gear 39 drives the governor shaft 57 includes the shaft 87 which has a lower bearing in the stud 80 and an upper bearing in the frame plate 12. Another shaft 90 has hearings in the frame plates 11 and12. Gear 39 drives shaft 87 by means of the pinion 88, and the gear 89 on shaft 87 drives shaft 90 by engagement with pinion 92. The shaft 90 carries a gear 91 which is in mesh with the pinion 58 on the governor shaft.

When the clockis wound up the gear train above described tends to rotate the governor shaft and sound the alarm but rotation of the governor shaft is normally prevented by the alarm release spring 53 which has a downwardly projecting extension 93 the end of which is in the path of the cross member 59. By engagement with the cross member the extension 93 prevents rotation of the governor shaft.

A manually operated alarm shut-off is also provided but since this device may be of any known or suitable construction it has not been shown.

The operation of our improved alarm clock will now be described.

The clock is wound by turning the key 34 and shaft 33 in a clockwise direction as seen from the back of the clock. This tightens the main spring in barrel 35 and tends to rotate the barrel and the gear 36 in the same direction as'the direction in which the key is turned. As soon as the main spring becomes partially wound the barrel and gear actually start to rotate, but very slowly due to the restraint imposed by the escapement in the time train. Each time the winding key is released during the winding operation a tooth of the ratchet wheel 40 operatively engages the pawl 43 but since the gear 39 on which the pawl is mounted cannot rotate at this time the pawl prevents backward rotation of the ratchet wheel and the shaft 33.

The winding of the clock not only tensions the main spring but also restores the programming cam 77 in case the alarm has run down prior to the start of the winding operation. When the winding key is turned the gear 42 on shaft 33 rotates in the direction of the arrow and rotates gear 79 and cam 77. The rotation of gear 79 continues as winding proceeds until the blank section 86 on gear 79 reaches the teeth of gear 42, when the rotation of gear 79 necessarily ceases. At this time the pin 82 is in engagement with the spring 83, which prevents the last tooth on gear 79 from getting out of mesh with the teeth of gear 42 during the remainder of the winding operation, and thus insures that when the gear 42 starts to rotate in the opposite direction upon release of the alarm it will rotate the gear 79. In Fig. 2 the cam 77 is shown in restored position, ready for the alarm to be set off.

As the clock is now running from power supplied by the main spring the projecting member 50 on the hour gear 49 will eventually reach the opening in the alarm set gear 51, whereupon the hour gear and the sleeve on which it is mounted slide upward a short distance on the center shaft. This movement is due to tension in the release spring 53, which follows up the movement and in so doing moves its extension 93 out of the path of the cross member 59 of the governor. This releases the alarm.

It will be recalled that the main spring is applying power through shaft 33, ratchet wheel 40 and pawl 43 which tends to rotate the gear 39 in a counterclockwise direction as seen from the back of the clock. The gear 39 accordingly starts to rotate now and drives the governor shaft 57 through the medium of the alarm train. The governor shaft and associated parts rotate in a counterclockwise direction as seen in Figs. 2 and 3. As the governor speeds up, centrifugal force tends to rotate the flyweights on their pivots, causing the brake members 70 and 71 to press against the drum 64 and exert a retarding force which limits the speed to a desired value.

At this time the cam follower 76 is resting in a depression of the programming cam 77 and consequently the drum 64 is in its Fig. 2 position. The strikers 72 and 73 do not impact the bell anvil 74, therefore, as they pass by and the alarm is not sounded. This is due to the fact that the drum is off center to the right. When the striker 72, for example, approaches the anvil 74 the drum 64 in its off center position causes the brake member 71 to rotate the fly weight 63 on its pivot in a clockwise direction and thus shortens the radius of the arc in which the striker 72 is moving enough to cause the striker to miss the anvil as it goes by.

When the gear 39 starts to rotate to drive the alarm train as described in the foregoing the gear 42 starts to rotate the gear 79 and the programming cam 77. The direction of rotation of the cam is counterclockwise as seen in Fig. 3. Very shortly, therefore, the cam follower 76 leaves the depression in the cam and rides up on to the first raised portion of the cam, thereby operating the lever 67 to shift the drum 64 to its Fig. 3 position. The alarm now begins to sound. The reason for this will no doubt be clear but it may be pointed out that when the striker 72, for example, approaches the anvil 74 with the drum in its Fig. 3 position, the drum has permitted the fly weight 63 to rotate on its pivot in a counterclockwise direction and increase the radius of the arc in which the striker is moving sufliciently so that the arc intersects the anvil and impact occurs when the striker reaches it.

The strikers 72 and 73 now impact the anvil 74 alternately during each rotation of the governor and the alarm is sounded, as stated in the preceding paragraph. Since the fly weights are pivoted, as each striker impacts the anvil it rebounds slightly, or far enough so that it passes the anvil without reengaging it. This permits the bell to vibrate freely and give a clear tone.

As the cam 77 continues its rotation the next depression in the cam moves under the cam follower 76 thus permitting the spring 78 to operate the lever 67 and shift the drum 64 to its Fig. 2 position. In this position of the drum the alarm is silent, for reasons already explained.

When the next raised portion of cam 77 reaches the cam follower the drum 64 is shifted again to its Fig. 3 position and the alarm again begins to sound, as previously explained.

Unless the manual shutoff is actuated to stop the alarm, the operation will continue in this manner, with alarm periods alternating with silent periods under control of the programming cam 77, until the wide tooth 85 on gear 79 engages a tooth of gear 42. This stops fur ther rotation of gear 42 and gear 39 and stops the alarm, which has run down. Thus the tooth 85 acts as a stop against which the main spring reacts to continue driving the time train.

The next time the clock is wound the programming cam is restored in the manner previously explained, thereby preparing the clock for another operation at the time for which the alarm has been set.

It will be seen from the foregoing that the invention provides a new and improved alarm mechanism having a number of advantages over prior alarm mechanisms. While the invention has been described in considerable detail, it will be understood that modifications can be made and that we do not, therefore, desire to be limited to the precise form of the invention which is shown and described herein, but wish to include and have protected by Letters Patent all forms of the invention which come within the scope of the appended claims.

We claim:

1. In an alarm clack, a shaft and means for rotating it, a centrifugal governor controlling the speed of rotation, said governor comprising a drum having two positions and a pair of fiy weights rotating with said shaft and having parts engaging said drum in both positions thereof, and a sound producing device impacted by each fly weight during rotation of said shaft when said drum is in one position but not when said drum is in the other position.

2. In an alarm clock as claimed in claim 1, a programming cam rotated concurrently with the rotation of said shaft, and means including a cam follower cooperating with said cam to move said drum back and forth between its two positions.

3. In an alarm clock as claimed in claim 1, a pivoted lever supporting said drum and operable to shift said drum from one said position to the other, a programming cam, means for rotating said cam while said shaft is rotating, and a cam follower cooperating with said cam to operate said lever as set forth.

4. In an alarm clock, a shaft and means for rotating it, a member carrying a striker and connected to said shaft by a pivot, an element for controlling the path of said striker during rotation of said shaft, said element providing a surface with which said member is main- 6 tained in engagement by centrifugal force acting to rotate said member on its pivot, a bell positioned adjacent said path, and means for adjusting the position of said element to alter said path in the vicinity of said bell to thereby cause said striker to impact said hell or miss the same, depending on the adjusted position of said element.

5. In an alarm clock, a shaft and means for rotating it, a member carrying a striker and connected to said shaft by a pivot, an element for controlling the path of said striker during rotation of said shaft, said element providing a surface with which said member is maintained in engagement by centrifugal force acting to rotate said member on its pivot, means for moving said element between two positions in which said surface controls the rotation of said member on its pivot to cause said striker to revolve in two different paths, respectively, a bell, and means supporting said bell in a position where it is impacted by said striker when revolving in one path but not in the other.

6. In an alarm clock, a shaft and means for rotating it, a member connected to said shaft by means including a pivot, a striker carried by said member, means providing a surface with which said member is maintained in engagement by centrifugal force acting to rotate said member on its pivot, whereby said striker is constrained to revolve in a definite path during rotation of said shaft, a bell supported in a position adjacent said path where it is impacted by said striker at each revolution thereof, and means effective to change the position of said surface and thereby alter said path to cause said striker to miss said bell.

References Cited in the tile of this patent UNITED STATES PATENTS Number Name Date 465,783 Murphy et al. Dec. 22, 1891 761,167 Hardy May 31, 1904 FOREIGN PATENTS Number Country Date 19,691 Great Britain Oct. 15, 1903 677,769 France Dec. 18, 1929

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