US 3675410 A
A clock setting mechanism for automatically and instantaneously shifting the hour hands of clocks forward or backward by a predetermined amount such as an hour for the purpose of complying with semi-annual changes between "Standard Time" and "Daylight Saving Time." In addition to the conventional clock drive mechanism including the friction drive which moves the hour hand, the clock is provided with power-operated driver members which normally are out of engagement with the hour hand assemblage. The hour hand normally turns in the conventional manner. When it is desired to advance or to set back the clock, this being done from a two o'clock (usually A.M.) position, the hour hand is engaged by one of the driver members, utilizing electromagnets and a remote switching control for this purpose, to effect a 1-hour, forward or backward adjustment as required by Daylight or Standard Time.
Description (OCR text may contain errors)
United States Patent Blackwell  3,675,410 1 July 11, 1972  REMOTE CONTROLLED CLOCK RESET DEVICE  Inventor: Dllll J. Blackwell, Naugatuck, Conn.  Assignee: The Lamb Wm Company, Naugatuck, Conn.
 Filed: June I, 1971 [2|] Appl. No.: 148,717
FOREIGN PATENTS OR APPLICATIONS 277,923 9/1927 Great Britain ..58/36 Pn'mnq- Examiner-Richard B. Wilkinson Assistant Examiner-George H. Miller, Jr. Attorney-H. Gibner Lehmann  ABSTRACT A clock setting mechanism for automatically and instantaneously g the hour hands of cloclta forward or backward by a predetermined amount such as an hour for the purpose of complying with semi-annual changes between Standard Time" and Daylight Saving Time." In addition to the conventional clock drive mechanism including the friction drive which moves the hour hand, the Clock '5 provided with poweroperated driver members which normally are out of engagement with the hour hand asemblage. The hour hand normally turns in the conventional manner. When it is desired to advanoe or to set back the clock, this being done from a two o'- clock (usually AM.) position, the hour hand is engaged by one of the driver members, utilizing electromagneta and a remote switching control for this purpose, to effect a 1-hour, forward or backward adjustment as required by Daylight or Standard Time.
lzumsmwh n um REMOTE CONTROLLED CLOCK RESET DEVICE BACKGROUND This invention relates to clock resetting mechanisms. and more particularly to devices of this type for resetting the hour hands of clocks. In the past a significant problem has arisen each Spring and Fall when the changeover between Daylight Saving Time and Standard Time occurs. In installations where large numbers of clocks are involved, as inradio or television studios or large industrial plants, the task of resetting each of the clocks has proven to be an unsatisfactory, costly and timeconsuming one. Previous systems involved shutting off power to the clocks at 2 A.M. for l hour to effect a setback of l hour in the Fall, and manually advancing the clocks at 2 AM. by l hour in the Spring to effect the advance to Daylight Saving Time. Such methods were rather clumsy in operation, were non-automatic, depending on the diligence of maintenance personnel, and were expensive in terms of the labor required to achieve the desired objective.
SUMMARY The above drawbacks and disadvantages of previous clock resetting procedures are obviated by the present invention, which has for one object the provision of an improved clock resetting device which is semi-automatic, especially simple in its construction, completely reliable to operate, and which requires a minimum of time and effort on the part of the operating personnel. A related object of the invention is the provision of an improved device a above set forth, which is particularly inexpensive and economical to produce. These objects are accomplished, in the two illustrated embodiments of the invention by the provision of a novel combination of slip or friction drive by which the clock hour hand is normally advanced by the conventional clock mechanism, and by provision of an additional, positivetype driver which is employed to temporarily overcome the slip drive during the resetting interval. The position drive mechanism comprises an assemblage of a driven member rigid with the hour hand, and two pivoted driver members normally out of engagement with the driven member. The two pivoted driver members are held disengaged by helical biasing springs during the normal operation of the clock. Each of the pivoted driver members is selectively actuatable by energization of an electromagnetic means. When it is desired to effect a resetting of the clock either forward or backward from its 2 AM. position, the proper one of the pivoted numbers is caused to engage and shift the driven member an extent by energization of the electromagnetic means. The pivoted member thus causes the assemblage of the driven member and rigid hour hand to move through a portion of a revolution corresponding to an instantaneous 1-hour change in the desired direction. Rotation through the proper arc is insured by the provision of a limit pin mounted on the clock gear drive, which cooperates with a slot in a disk portion of the driven member hour hand assemblage.
An important feature of the invention is that the present im proved mechanism for resetting the hour hand can be quite readily incorporated in existing clock structures, and can provide efficient and reliable operation under various conditions and long usage. The likelihood of failure of the mechanism, or of repairs to the mechanism being required is small, due to the simplicity of construction.
Still other features and advantages will hereinafter appear.
In the drawings which are illustrative of several embodiments of the invention:
F IG. 1 is a diagrammatic representation of a clock resetting mechanism as provided by the invention, showing the relative positions of the driving members when neither is engaged with the driven member, and also illustrating electrically operable means and the control circuitry for actuating the mechanism.
FIG. 2 is a side elevational view of the resetting mechanism of FIG. 1.
FIG. 3 is a transverse sectional view taken on the line 3-3 of F IG. 2.
FIG. 4 is a front elevational view illustrating a modified form of the invention, employing two rotatable carrier plates on which two pawls are respectively pivoted, and showing in broken outlines the pawl positions for engaging the shoulder of the driven member.
FIG. 5 is an oblique sectional view taken on the line 5-5 of FIG. 4.
Referring to FIGS. 1-3, there is illustrated a clock mechanism having a dial 20 provided with the usual indicia or numbers 22, from I to l2, representing the hours in the day. Tumably mounted at the center of the dial is an hour hand 24, carried by sleeve 26. The hour hand 24 has a hub 28, which is press-fitted onto the sleeve 26 for mounting purposes. Behind the dial 20 and coaxial with the sleeve 26 is the conventional drive gear 30, powered so as to advance the hour hand at the usual rate of turning for indicating time. The gear 30 is carried on a hollow shaft 32, being secured thereto by a hub 33. A retainer washer 35 is fastened to the shaft 32 to prevent axial motion between the sleeve 26 and the shaft 32. Extending through the hollow shalt 32 and sleeve 26 is a stem 34 which carries a minute hand 36. The stem 34 is driven by suitable gearing (not shown) to provide the proper ratio of rotation between the minute and hour hands.
In accordance with the present invention there is provided, in conjunction with the above structure, a novel device to provide for instantaneous resetting of the hour hand of the clock in order to adjust for the semi-annual changes between Standard and Daylight Savings Times. This device utilizes a multipart slip or friction drive assemblage 38 for advancing the hour member at the usual rate, and further comprises a positive drive assemblage 40 for instantaneously advancing or setting back the hour hand by an interval of l hour. The friction drive comprises the drive gear 30, a resilient spider spring 42, and a combination drive and limit-stop disc 44. The assemblage of the disc 44, sleeve 26, hub 28, and hour hand 24 is hereinafter referred to collectively as a driven member. and such rigid, turnable assemblage is frictionally driven by the spider spring 42 whose small-diameter center portion frictionally engages one face of the gear 30. The said driven member further includes an arm 46 having opposite faces 48 and 50, said arm being affixed to the sleeve 26, disc 44, and hour hand 24 to move therewith as a unit.
The drive disc 44 is provided with a limit slot 52 which cooperates with a stop pin 54 mounted rigidly on the drive gear 30 to restrict relative angular movement between the gear and disc to an arc of 30.
By the present invention there is further provided electrically powered means generally represented in FIG. 1 by the numeral 58, comprising levers 60 and 62 respectively having long and short leg portions 64, 66 and 68, 70 and respectively having magnetic armatures 72 and 74. Pivots 76 and 78 turnably mount the levers 60 and 62 respectively. The levers 60 and 62 are normally biased out of engagement with the arm 46 by helical extension return springs 80 and 82 respectively attached thereto. The disengaged positions of the levers 60 and 62 are determined by pins 84 and 86 respectively, carried by the clock framework (not shown). The advanced, engaged positions of the levers 60, 62 are determined by stop pins and 87 (FIG. 1) respectively, which take up the momentum of the levers afler these have driven the arm 46 the required distance. In connection with this latter, the pin 54 and slot 52 are, of course, the dominant influence in setting the hour hand the exact amount, and the pins 85, 87 prevent excess force from being applied to the pin 54. The pins 85, 87 are also mounted on the clock frame (not shown).
The electrically powered means 58 further includes electromagnets 88 and 90 which can be selectively energized by control means 92, comprising momentary contact switches 94 and 96, a source of electric power 98 and current-carrying leads 100, 102 and 104.
From the above description, the operation of the reset mechanism can now be readily understood. Considering FIGS. 1 and 2, the levers 60 and 62 are shown out of engagement with the arm 46. Under these circumstances the clock operates normally, and the gear 30, spider spring 42, and driven member assemblage comprising the disc 44, sleeve 26, arm 46 hub 28 and hour hand 24 all rotate simultaneously about their common axis.
Assuming the transition from Standard to Daylight Saving Time is now to be effected, this is accomplished when the hour hand 24 is at the 2 oclock position. This is the position of the arm indicated in FIG. I. Momentary contact switch 94 is now closed, thereby energizing the electromagnet 90. The armature 74 is magnetically attracted toward the electromagnet 90, causing the lever 62 to turn counterclockwise about its pivot 78. This in turn causes the short leg portion 70 of lever 62 to engage one side surface 48 of the arm 46 so as to effect a clockwise shift of the driven member assemblage 38. The amount of clockwise shift of the hour hand is limited to the proper amount (30 from its previous position, corresponding to 1 hour) by the stop pin 54 which restricts relative rotation between the gear 30 and the disc 44 to that permitted by the pin engaging one end or limit of the slot 52. Upon release of the momentary contact switch 94 the lever 62 is returned to its disengaged, retracted position by the helical extension return spring 82.
In a very similar manner the transition from Daylight Saving to Standard Time is effected as follows: With the hour hand 24 and the arm 46 in their respective positions shown in FIG. 1, corresponding to 2 A.M., the momentary contact switch 96 is closed, energizing the electromagnet 88, which then magnetically attracts the armature 72 and thereby causes the lever 60 to turn in a clockwise direction about its pivot 76. The short leg portion 68 of the lever 60 now engages the opposite surface 50 of the arm 46 and causes the driven member assemblage 38 to turn counterclockwise by an amount determined by the stop pin 54, which now engages the opposite end of the slot 52. Upon release of the momentary contact switch 96 the lever 60 is returned to its disengaged position by the helical return spring 80. In this latter operation, a l-hour counterclockwise shift of the hour hand has been achieved.
Another embodiment of the invention is set forth in FIGS. 4 and 5. In FIG. 5 there is shown a clock mechanism including a dial 20, minute hand 36 press-fitted onto the stem 34, and the hour hand 24 has provided with the hub 28 which is pressfitted onto the sleeve 26. The stem 34 is coaxial with the hollow shaft 32. The conventional drive gear 30 is provided with its hub 31, by which the gear is rigidly mounted on the hollow shaft 32. The gear mechanism which drives the gear 30 is so arranged as to provide the proper ratio of rotation between the minute and hour hands. The stem 34 is provided with a retainer washer 35 which secures the sleeve 26 and prevents axial motion of the sleeve with respect to the hollow shaft 32 and stem 34.
In accordance with the invention there is provided a modified clock resetting mechanism which will likewise instantaneously reset one or more clocks in accordance with semi-annular changes between Daylight and Standard Times. This modification of the invention comprises, in combination with the multi-part friction drive 38 driving the hour hand in the usual manner, a unique positive drive for temporarily overcoming the friction drive and effecting an instantaneous l-hour shift of the hour hand 24. Referring to FIG. 5, the friction drive comprises the drive gear 30, spider spring 42 and combination drive and limit-stop disc 44. The drive gear 30 is provided with the stop pin 54, which is rigidly mounted thereon and which cooperates with the limit slot 52 in the disc 44. The driven member in this embodiment comprises the hour hand 24, the sleeve 26, the disc 44, and a circular plate 108 which is rigid with the sleeve, hour hand and disc. The circular plate 108 has two shoulder portions 110 and 112 as shown in FIG. 4, for purposes described below.
Referring to FIGS. 4 and 5, two carrier plates H4 and H5 are shown, coaxial and turnable with respect to the sleeve 26. The carrier plates 114 and 115 are mounted tumably on the sleeve 26 and held in place by retainer washers I16 and 117.
The plates 114, have the notches 107 and 109 respectively, providing shoulders 11! and 113 for cooperation with a pin 119 carried on the clock frame (not shown), to take up excess force from the plates 114, 115 and relieve the stop pin 54 of stress which might cause it to bend. The carrier plates 114 and I 15 are provided with pawls 1 I8 and 120 respectively, pivotally mounted thereon by means of pivots 122 and 124. The pawls 118 and 120 are biased to normally disengaged positions by helical coil return springs 126 and 128 respectively, and rest against stop pins 230 and I32 which are rigidly mounted respectively on the plates 114 and 115. The pawls I18 and 120 are provided with links I34 and 136 which have magnetic cores or armatures 138 and 140 for cooperation with electromagnets I42 and 144 respectively. The electromagnets can be electrically energized by control circuitry similar to that shown in FIG. 1. The carrier plates 114 and I15 are yieldably held in normal, cocked positions respectively by pairs of springs I50, 151, I52 and 153, each spring having one end anchored to the clock frame (not shown). Thus, the plates 114 and 115 are also restricted to limited turning thereby.
The operation of this modified form of reset mechanism can now be understood. With the hour hand 24 in the 2 A.M. position, the circular plate 108 will have the position shown in FIG. 4. Advancement of the hour hand by 1 hour would be accomplished by energization of the electromagnet 144. The pawl 120 would thereby be tumably driven clockwise about the pivot 124 a fraction of a turn until the extremity of the pawl engages the edge portion of the circular plate I08. Further turning of the pawl about its pivot 124 is prevented; however, the carrier plate 115 is now caused to turn clockwise, and the pawl I20 slides along the edge of the circular plate eventually making contact with the shoulder portion 112 thereof and thereby positively driving the plate clockwise. The amount of clockwise rotation is limited to that corresponding to l hour by the stop pin 54 and the limit slot 52 in the disc 44. Upon completion of the l-hour shift, the electromagnet 144 is disabled and the return spring 128 disengages the pawl from the circular plate 108. The driven member having the hour hand is then advanced by the friction drive at the conventional rate of rotation.
In a similar fashion, from the 2 AM. position the clock can be set back I hour by energization of the electromagnet 142. The core 138 is magnetically attracted downward as viewed in FIG. 4, causing the pawl I18 to turn counterclockwise about its pivot 122 until the extremity of the pawl ll8 engages the edge portion of the circular plate 108. Since further turning of pawl [[8 about its pivot 122 is prevented, the carrier plate 114 is caused to rotate counterclockwise and the pawl [18 slides along the edge of the circular plate 108, making contact with the shoulder portion I10 thereof and thereby positively driving the plate and hour hand counterclockwise. The amount of counterclockwise rotation is limited to that corresponding to 1 hour by the stop pin 54 and the limit slot 52 in the disc 44. When the shift is completed the electromagnet 142 is disabled, and the return spring 126 disengages the pawl 118 from the circular plate 108, allowing the driven member to be frictionally advanced by the friction drive 38 at the usual rate of rotation.
It will now be understood from the foregoing that I have provided a novel and improved clock resetting mechanism which is reliable in operation and simple in construction. The device can be readily adapted to existing clock mechanisms and requires no special complicated equipment for its operation. It is particularly suitable for simultaneous control in an installation where large numbers of clocks are required to be reset.
Variations and modifications are possible without departing from the spirit of the invention.
l. A clock, comprising in combination:
a. a turnable hour member,
b. indicia associated with the hour member representing the hours of the day and night,
c. a multipart slip drive to permit advancement of the hour member, said slip drive being connected to said hour member,
. a tumable driven member rigid with the hour member,
e. selective oppositely operable electrically powered means engageable with the driven member for turning the latter through predetermined portions of a revolution in either of two directions,
control means operable at will for activating said electrically operable means in either of said directions, to
thereby turn the driven member and hour member either backward or forward through a predetermined arc.
The invention as defined in claim 1, wherein:
a. said electrically powered means comprises two electromagnets,
b. the control means comprises circuitry connected with the electromagnets and a switching device for controlling said circuitry, and
c. a source of electric power connected with said circuitry.
3. The invention as defined in claim 1, wherein the selective powered means comprises:
a. movable driver members adapted to positively shift the driven member, thereby to turn the latter and the rigid hour member, and
b. a carrier pivotally mounting said driver members.
4. The invention as defined in claim 3, and further includa. a stop means for halting said driven member after it has been shifted through a predetermined arc in either of said two directions.
6. The invention as defined in claim 5, wherein said stop means comprises:
a. a pin mounted on one of the parts of said slip drive,
b. said tumable driven member having a slot in which the pin is received.
7. The invention as defined in claim 1, wherein said electrically powered means comprises:
a. a pair of levers engageable with said driven member,
b. armatures connected with said levers, and
c. electromagnetic means acting on said arrnatures.
8. The invention as defined in claim 7, wherein:
a. said driven member has an arm projecting from it, and
b. said levers being adapted to strike opposite sides of the arm to effect turning movement of the driven member.
9. The invention as defined in claim 8, wherein:
a. said levers are substantially L-shaped with long and short leg portions,
b. said short leg portions being engageable with said arm.
10. The invention as defined in claim 1, wherein said electrically powered means comprises:
a. a pair of pawls engageable with said driven member,
b. discs, coaxial and tumable with respect to the driven member, and on which the pawls are respectively pivotally mounted.
11. The invention as defined in claim 10, wherein:
a. said electrically powered means further includes links connected to said pawls,
b. armatures connected to the links, and
c. magnet coils acting on said armatures.
12. The invention as defined in claim l I, wherein:
a. said driven member has shoulders respectively engageable by said pawls, and
b. spring means biasing the pawls normally out of engagement with said shoulders.
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