US3407402A - Clock alarm mechanism having impulsed striker apparatus - Google Patents

Description

Oct. 22, 1968 lscm ETAL 33075402 CLOCK ALARM MECHANISM HAVING IMPULSED STRIKER APPARATUS 2 Sheets-Sheet 1 Filed June 3, 1965 INVENTORS DAVID MORRISON BY RALPH C. Roamsou om'a Oct. 22, 1968 Q'MORRISQN ETAL 3,407,402

CLOCK ALARM MECHANISM HAVING IMPULSED STRIKER APPA ATUS Filed June 5, 1965 I 2 Sheets-Sheet 2 INVENTORS DAVID MORRISON BY RALPH C. Rosmsou United States Patent 3,407,402 CLOCK ALARM MECHANISM HAVING IMPULSED STRIKER APPARATUS David Morrison and Ralph C. Robinson, Athens, Ga., as-

signors to General Time Corporation, New York, N.Y., a corporation of Delaware Filed June 3, 1965, Ser. No. 461,009 8 Claims. (Cl. 340392) ABSTRACT OF THE DISCLOSURE A percussion type alarm mechanism is disclosed. A pulsed relay causes movement of a striker arm away from a gravity stable position.

Upon return to the stable position, the striker contacts the gong.

This invention relates generally to alarm clocks and more particularly concerns an audible alarm mechanism especially suited for battery operated clocks.

It is an object of the invention to provide an audible alarm mechanism that, in addition to having SET, automatic ON, and OFF control, turns itself off after a predetermined interval. Thus, when utilized in a battery powered clock, operation of the alarm when the clock is unattended will not unduly drain the battery.

Another object is to provide an alarm mechanism of the above kind which produces a slow beat, bell-ringing sound that is both more audibly pleasant and more conservative of the driving energy. With more particularity, it is an object to provide an alarm as characterized above which effectively uses gravity for imparting the bell ringing impetus so as to easily control the alarm sounding frequency.

A further object is to provide an alarm mechanism of the above character that utilizes few parts and is well suited for miniaturization and economical mass production.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIGURE 1 is a perspective of a clock mechanism embodying the present invention;

FIGS. 2 and 3 are fragmentary perspectives of a portion of the mechanism, in alternate operating positions, otherwise shown in FIG. 1;

FIG. 4 is a fragmentary perspective of a portion of the mechanism appearing in FIG. 1; and

FIGS. 5, 6 and 7 are fragmentary elevations of the mechanism appearing in FIG. 4 during different stages of its operating cycle.

While the invention will be described in connection with a. preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

Turning first to FIG. 1 there is shown a clock mechanism 10 embodying the invention and intended for mounting in a decorative case of any desired kind or style. The mechanism 10 includes a frame formed of front and rear plates 11 and 12, respectively, held in rigidly spaced relation by a plurality of pillars 13 and sandwiching a rigidly supported central plate 14. A timing train 15 is mounted between the frame plates 11, 12 and is driven, in the preferred construction, by a D.-C. motor, not shown, powered from a dry cell battery fitted in a battery holder 16 mounted on the mechanism frame. The output of the timing train 15 is a shaft and sleeve stack 17 adapted to receive the usual set of clock hands.

3,407,402 Patented Oct. 22, 1968 As may be estimated by the relative size of the battery holder 16, the representative mechanism 10 is quite compact, being about three inches square as seen from the front with the frame plates 11, 12 being spaced about one and one half inches apart.

The clock mechanism 10 includes an audible alarm adapted to be sounded at a predetermined time, and the preferred alarm mechanism sounding device is a bell 20 mounted on a bracket 21 that is fixed to the rear frame plate 12. The bell 20 is sounded by a striker 22 (see also FIG. 4) whose flexible shaft 23 is fixed to a carrier lever 24.

Pursuant to the invention, the sounding stroke of the striker 22 is gravity impulsed and a solenoid 25, driven from the battery in the holder 16, repositions the striker 22 after each stroke with the result that a slow measured alarm beat is obtained. To this end, the carrier lever 24 is mounted on a shaft 26 pivoted in the plates 11, 12 so that the lever 24 swings vertically. A weight 27 is mounted on the lever 24 so as to pull the lever clockwise, as seen in FIGS. 4 to 7, from a high position shown in FIGS. 5 and 7 to a low position shown in FIG. 6. With the lever 24 in its low position and the flexible striker shaft 23 unflexed, the striker 22 just clears the bell 20. However, the flexibility of the shaft 23 allows the striker 22 some overtravel as the carrier lever 24 swings clockwise so that the bell 20 is sharply and cleanly struck when the lever moves from its high position to its low, or active, position. Then the striker 22 springs back out of contact with the bell 20, so that the latter produces a clear, fully reverberating sound.

The solenoid 25 arrests the gravity impulsed sound ing stroke of the carrier lever 24 and returns the lever to its high position. In its preferred form, the solenoid 25 includes a pair of coils 31 and 32 wound about pole pieces 33 which are fixed in a subframe 34 that is folded into a U-shaped configuration. An armature 35 is pivoted on the subframe 34 so that energization of the coils 31, 32 drives the armature 35 clockwise, as seen in the drawings, against sleeves 36 formed of non-magnetic material covering adjacent portions of the pole pieces 33. The sleeves 36 prevent the armature 35 from magnetically sticking against the pole pieces 33.

Control of the solenoid 25 is attained by a switch defined by a resilient arm 41, bent from the sub'frame 34 and carrying a first switch contact 42, and a second flexibly resilient arm 43, supported by an insulating block 44 on the rear frame plate 12, which carries the second switch contact 45. When relaxed, the arms 41, 43 hold the contacts 42, 45 slightly apart so that the switch is normally open and the solenoid 25, electrically connected in series with the contacts 42, 45, is not energized.

To operate the switch, the carrier lever 24 includes a tab 47 shielded by an insulating band 48 that pushes the contacts 42, 45 together when the lever 24 moves to its active position. That is, movement of the carrier lever 24 to its FIG. 6, active position causes the band 48 to abut and deflect the flexible arm 43 until the contacts 42, 45 close. Engagement of the tab 47 with the switch arm 41, through the intervening band 48, the arm 43 and the contacts 42, 45, limits clockwise movement of the lever 24 and defines the active position of the carirer lever.

When the solenoid 25 is energized through the closed contacts 42, 45, the armature 35 swings sharply in a clockwise direction against the pole piece sleeves 36. The armature 35 includes a finger 49 that strikes the somewhat resilient arm 41 as the armature 35 swings against the sleeves 36. The blow exerted by the finger 49 is transmitted through the contacts 42, 45 andimparted to the tab 47, thus swinging the weighted carrier lever 24 counterclockwise toward its high position. The weight 27 gradually overcomes the force of the blow from the armature,

and the weighted carrier lever 24 again swings clockwise to its active position. Since the relatively low acceleration force of gravity drives the striker 22 in its sounding stroke and also limits the return swing of the carrier lever 24, the alarm beat generated is desirably slow and more measured than the usual rapid sounding of an alarm clock bell.

In carrying out the invention, the carrier lever 24 is held in its high position until a preselected time as determined by the timing train and then is released for only a fixed interval of time before being returned and held in its high, or rest, position. That is, the alarm only sounds for a given maximum time interval, ten to twelve minutes in the preferred embodiment, even if the alarm is not manually silenced more quickly by the clock user. Thus, if the clock is left unattended, operation of the alarm will not unduly drain the battery powering the clock mechanism.

For so controlling the carrier lever 24, a blocking element 50 is slidably mounted in a slot 51 formed in the rear frame plate 12 and a notch 52 formed in the middle plate 14. The blocking element 50 is urged by a tensioned spring 53, anchored to the front frame plate 11 for movement through first, second and third positions illustrated respectively in FIGS. 1, 2 and 3. In its first position, the 'blocking element St is positioned so that the carrier lever 24 abuts an edge 55 of the blocking element so as to hold the carrier lever 24 in its rest position. When moved to its second position, to the right in FIG. 1 and down to the FIG. 2 position, a notch 56 in the blocking element edge 55 is alined with the carrier lever 24 so as to free the latter for movement into its active position. In the third position of the blocking element 50, seen in FIG. 3, the notch 56 again moves out of alinement with the carrier lever and the carrier lever is again held by the edge 55 in its rest position.

The blocking element 50 is controlled by a latch 60 which is interlocked and pivoted on a tab 61 bent from the front frame plate 11. The latch 60 is generally L-shaped and includes one leg formed with stepped abutments 61, 62 and 63 which engage and support the blocking element 50 in its first, second and third positions, re spectively. The blocking element 50 is held against the abutments 61-63 by the spring 53. The opposite leg of the latch 60 engages an hour wheel 65 which forms part of the timing train 15. A spring 66 is interposed between the latch 60 and the middle frame plate 14 so as to bias the latch against the hour wheel 65.

The hour wheel 65 cooperates in the usual way with an alarm indicator gear 67. The gear 67 is angularly settable by a setting knob 68. The hour wheel 65 rotates one revolution every twelve hours and is axially slidable. The wheel 65 and the gear 67 have interengaging cam portions 69 which mate once every full revolution of the hour wheel 65. When the cam portions 69 engage one another, the hour wheel 65 is urged axially away from the front frame plate '11 so as to tilt the latch 60 against the bias of the spring 66.

Thus, at the time determined by the setting of the alarm gear 67, the hour wheel 65 begins to move axially as the cam portions 69 ride into engagement. Assuming the blocking element 50 to be initially resting on the abutment 61, axial movement of the hour wheel 66 rocks the latch 60 clockwise as seen in FIGS. l3 so as to first drop the blocking element 50 from the abutment 61 to the abutment 62. In this second position of the blocking element, the notch 56 becomes alined with the carrier lever 24 so that the carrier lever is free to move, under the force of gravity, toward its active position with the result that the alarm is sounded. Following an interval of about ten to twelve minutes, the cam portions 69 separate the hour wheel 65 and the alarm gear 67 a maximum amount which is effective to rock the latch 60 still further in a clockwise direction and drop the blocking element 50 4 from the abutment 62 to the abutment-63. In this third position of the blocking element, the notch 56 moves out of alinement with the carrier lever 24 and the edge 55 of the blocking element holds the carrier lever in its rest position, thus silencing the alarm.

To provide for manual control of the alarm, an'operator 70 is resiliently coupled to the blocking element 50 and is formed with a lug 71 positioned to'engage a cam surface 72 on the latch 60. In.the illustrated construction, the operator 7 0 carries pins 73 which are received in slots 74 formed in the blocking element 50 so that the operator 70 and the blocking element 50 can slide relative to one another. A spring 75 couples one of the pins 73 and a lug 76 on the blocking'element 50 so as to bias the operator 70 rearwardly of the rear frame plate 12, i.e., up in FIGS. 2 and 3.

It can thus be seen that pulling the operator 70 rearwardly sets the alarm by shifting the blocking element 50 toward its first position since the spring 75 holds the pins 73 at one end of the slots 74 to establish a normal rigid connection between the operator 70 and the blocking element 50 for movement in the rearward setting direction. The operator 70 can thus slide the blocking element 50 in the frame plates 12, 14 to its first position wherein the latch 60 pivots under the force of its spring 66 so that the abutment 61 swings under and holds the blocking element 50 in its first position.

With the blocking element 50 in its second FIG. 2 position, the alarm being sounded at that time, inward movement of the operator 70 slides the pins 73 within the slots 74 so that the operator lug 71 engages the latch camming surface 72 so as to tilt the latch 60 clockwise sufiiciently far to swing the abutment 62 from the blocking element 50. The blocking element is thus freed for movement against the abutment 63 under the force of the spring 75 and, as previously explained, movement of the blocking element 50 into its third position silences the alarm. As soon as manual pressure is released from the operator 70, the spring 75 returns the operator to its normal position relative to the blocking element 50 with the pins 73 abutting the ends of the slots 74. v

It can therefore be seen that the alarm mechanism described above, in addition to having the usual SET, automatic ON and OFF control capabilities, also functions to turn itself off after a predetermined time interval. This feature is particularly useful in a battery powered clock mechanism since initiation of the alarm operation when the clock is unattended will not unduly drain the battery.

Since the alarm mechanism is gravity actuated, a slow more measured alarm beat is produced which is found to be both more audibly pleasant and also more conservative of the electric energy required to drive the alarm mechanism. Those skilled in the art will also appreciate that the mechanism described in detail above is particularly compact, utilizes few parts and is therefore well suited for miniaturization and economical mass production.

We claim as our invention: I

1. In a clock having a timing train supported in a frame, an alarm mechanism comprising, in combination, a bell fixed on said frame, a carrier lever pivoted for vertical swinging on said frame and being weighted for movement from a rest position to an active position, a striker mounted on said lever so as to strike and sound said bell upon movement of the lever from said rest to said active position, a solenoid positioned on said frame adjacent said lever, said solenoid having an armature for engaging and impulsing said lever from said active toward said rest position upon energization of said ,solen oid, means including a normally open switch on said frame for energizing said solenoid when said switch closes, said switch being positioned to be closed by said lever when in said active position, and a blocking element on said frame operable by said timing train for holding said lever in said rest position until a predetermined time.

2. In a clockhaving a timing train supported in a frame, an alarm mechanism comprising, in combination, a bell fixed on said frame, a carrier lever pivoted for vertical swinging on said frame and being weighted for movement from a rest position to an active position, a striker mounted on said lever so as to strike and sound said bell upon movement of the lever from said rest to said active position, a solenoid positioned on said frame adjacent said lever, said solenoid having a rotary armature for engaging and impulsing said lever from said active toward said rest position upon energization of said solenoid, a normally open switch defined by a pair of resilient arms mounted on said frame, said switch being coupled to said solenoid so as to energize thelatter when closed, said arms being positioned to arrest said carrier lever in said active position with said lever closing said switch, and a blocking element on said frame operable by said timing train for holding said lever in said rest positon until a predetermined time.

3. In a clock having a timing train supported in a frame, an alarm mechanism comprising, in combination, a sounding device mounted on said frame, a lever pivoted on said frame for movement between a rest position and an active position, means including said lever for sounding said device when the lever is moved to said active position, a blocking element mounted in said frame for shifting movement through first, second and third positions, said element being effective to hold said lever in said rest position when the element is in said first and third positons while freeing said lever for movement to said active position when the element is in said second position, a latch pivoted on said frame and formed with three abutments successively holding said element in said first, second and third positions as the latch is rocked, and means including said timing train for slowly rocking said latch at a predetermined time so as to step said element along said abutment and thus sound said device while the element is in said second position.

4. In a clock having a timing train supported in a frame, an alarm mechanism comprising, in combination, a sounding device mounted on said frame, a lever pivoted on said frame for movement between a rest position and an active position, means including said lever for sounding said device when the lever is moved to said active position, a blocking element mounted in said frame for shifting movement through first, second and third positions, said element being effective to hold said lever in said rest position when the element is in said first and third positions while freeing said lever for movement to said active position when the element is in said second position, a latch pivoted on said frame and for-med with three abutments successively holding said element in said first, second and third positions as the latch is rocked, means including said timing train for slowly rocking said latch at a predetermined time so as to step said element along said abutment and thus sound said device while the element is in said second position, and a manual operator resiliently coupled to said blocking element and extending from said frame so that movement of the operator in one direction shifts the element to said first position, said operator and said latch having camming portions so that movement of the operator in the other direction rocks said latch to move said element to said third position.

5. In a ,clock having a timing train supported in a frame, an alarm mechanism comprising, in combination, a bell mounted on said frame, a carrier lever pivoted for vertical swinging on said frame and being weighted for movement from a rest position to an active position, a striker mounted on said lever so as to strike and sound said bell upon movement of the lever from said rest to said active position, a solenoid positioned on said frame adjacent said lever, said solenoid having an armature for swinging and impulsing said lever from said active toward said rest position upon energization of said solenoid, means including a normally opened switch on said frame for energizing said solenoid when said switch closes, said switch being positioned to be closed by said lever when in said active position, a blocking element mounted on said frame for shifting movement through first, second and third positions, said element being elfective to hold said lever in said rest position when the element is in said first and third positions while freeing said lever for movement to said active position when the element is in said second position, a latch pivoted on said frame and formed with three abutments successively holding said element in said first, second and third positions as the latch is rocked, and means including said timing train for slowly rocking said latch at a predetermined time so as to step said element along said abutments and thus sound said bell when the element is in said second position.

6. In a clock having a timing train supported in a frame, an alarm mechanism comprising, in combination, a bell mounted on said frame, a carrier lever pivoted for vertical swinging on said frame and being weighted for movement from a rest position to an active position, a striker mounted on said lever so as to strike and sound said bell upon movement of the lever from said rest to said active position, a solenoid positioned on said frame adjacent said lever, said solenoid having an armature for swinging and impulsing said lever from said active toward said rest position upon energization of said solenoid, means including a normally opened switch on said frame for energizing said solenoid when said switch closes, said switch being positioned to be closed by said lever when in said active position, a blocking element mounted on said frame for shifting movement through first, second and third positions, said element being elfective to hold said lever in said rest position when the element is in said first and third positions while freeing said lever for movement to said active position when the element is in said second position, a latch pivoted on said frame and formed with three abutments successively holding said element in said first, second and third positions as the latch is rocked, means including said timing train for slowly rocking said latch at a predetermined time so as to step said element along said abutments and thus sound said bell when the element is in said second position, and a manual operator resiliently coupled to said blocking element and extending from said frame so that movement of the operator in one direction shifts the element to said first position, said operator and said latch having camming portions so that movement of the operator in the other direction rocks said latch to move said element to said third position.

7. In a clock having a frame, an alarm mechanism comprising, in combination, a bell fixed on said frame, a carrier lever pivoted for vertical swinging on said frame and being weighted for movement from a rest position to an active position, a striker mounted on said lever so as to strike and sound said bell upon movement of the lever from said rest to said active position, a solenoid positioned on said frame adjacent said lever, said solenoid having a rotary armature for engaging and impulsing said lever from said active toward said rest position upon energization of said solenoid, a normally open switch defined by a pair of resilient arms mounted on said frame, said switch being coupled to said solenoid so as to energize the latter when closed, said arms being positioned to arrest said carrier lever in said active position with said lever closing said switch, and means for releasably holding said lever in said rest position.

8. In a clock having a timing train supported in a frame, the combination comprising, a lever pivoted on said frame for movement between a rest position and an active position, a blocking element mounted in said frame for shifting movement through first, second and third positions, said element being effective to hold said lever in said rest position when the element is in said first and third positions while freeing said lever for movement to said active position when the element is in said second position, a latch pivoted on said frame and formed with three abutments successively holding said element in said first, second and third positions as the latch is rocked, means including said timing train for slowly rocking said latch at a predetermined time so as to step said element along said abutment, and a manual operator resiliently coupled to said blocking element, and extending from said frame so that movement of the operator in one direction shifts the element to said first position, said oper- 8 i a ator and said latch having carnming portions so that movement of the operator in the other direction rocks said latch to move said element to said third position.

References Cited I UNITED STATES PATENTS 2,663,013 12/1953 Bronson 340395 3,041,601 6/1962 Wetzel 340388 X 3,158,986 12/1964 Haydon 340392 X JOHN W. CALDWELL, Primary Examiner;

H. I. PITTS, Assistant Examiner.

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