US2918969A - Program clock - Google Patents

Description

Dec. 29, 1959 L. KULL PROGRAM cLocK Filed Feb. 23. 1954 FIG.5

INVENTOR. Eo KULL Asls 3| wl A20 A535 A 82| C FIG.6

UnitedStates Patent G 2,918,969 PROGRAM CLOCK Leo Kull, Harrison, NJ. Application February 23, 1954, Serial No. 411,726 i 12 Claims. (Cl. 161-1) This invention relates to a program clock. More particularly it relates to a time keeping mechanism which can be conveniently pre-set to provide a substantial number `of signal or output effects at selected instances inl time during a given timing interval or period.

The general idea of a program clock which, for example, can be set to operate a control circuit at one minute intervals throughout a twenty-four hour period is not necessarily new. However, previous attempts have resulted in very complex and expensive mechanisms. When complexity is sacrificed, the selectivity or accuracy of the instrument decreases accordingly. lt is the aim of the present invention to do away with elab-orate drum mechanisms and punched tapes and the like and replace them with a simple and easily operable device.

. If by way of example a clock is considered which is -capable of being pre-set to close a switch or ring a bell or the like at any minute, on the minute, during a twenty-four hour interval, it is found that the clock must have one thousand four hundred and forty selectable operating points. The problem should be apparent at once. However, following the teachings of the present inventionv it is a simple matter to provide a clock which will cover a seven day period at one minute intervals, for example. The principle involved is susceptible of unlimited extension.

The present invention is based, in part, upon a charactertisic of rotating members operating at different speeds of rotation, which characteristic can best be explained in terms of a train of gears. If a pair of meshing gears is selected having x and y teeth, respectively, such that x and y do not have a common divisor other than 1, then a predetermined meshpoint will meet pe` riodically, but onlyl after a number of teeth on each gear equal to the product xy have passed through the mesh# point. A little reflection will reveal that between suc` cessive meetings of the predetermined meshpoint, that is,A during a single complete cycle of the gears, each tooth on one gear will have encountered every other tooth on the other gear at the meshpoint. lt can be demonstratedv that if the number of teeth on each gear are increased without changing the gear ratio, and, therefore, without; changing the relative speeds of rotation, the number of combinations of gear teeth encountering each other at themeshpoint will remain equal to the product xy. Since x and y obviously must each be greater than 1, it can also be demonstrated that both gears must each make more than one complete revolution during a complete cycle. This may be referred to as a diiferential cycle in order to distinguish it from conventional arrangements wherein one of the rotating members is arranged to make only one complete revolution in a given whole cycle of operation.

Now mark each gear around its periphery with a number of index marks. On the gear having nx teeth there can be placed x marks and on the gear having ny teeth there can be placed y marks where n is a positive integer. It should be obvious from the previous discussion that each index mark on one gear will encounter every other index mark on the other gear at the meshpoint` during. asingle complete cycle of the gears. The number of combinations is equal to the product xy. From ICC the above it will be clear that this represents the maximum number of combinations available with the selected gear ratio or ratio of speeds of revolution.

Assuming that it is known in advance how many cornbinations are desired it is a relatively simple matter to work backwards and ascertain the gear ratio. If the number 1440 is chosen which is the number of minutes in a twenty-four hour period, it is known from the above that this should represent the product of the terms of the gear ratio. It has also been established that there should be no common divisor for these terms. Therefore, the number 1440 is taken and factored to ascertain its prime factors. The result is The prime factors are then separated into two groups such that all the factors having a given value are in one group. The possible groupings are:

2X2 2 2 2=32 and 3 3 5=45 2 2 2 2 2 3 3=288 and 5:5 2X2 2 2 2 5=160 and 3 3=9 For reasons which will appear after reading the detailed description to follow, the ratio of 32:45 provides the preferred solution.

The same result can be reached if the speeds of rotation of the rotating members expressed as a fraction are chosen such that the reciprocals thereof are in the ratio of xzy wherein the two terms are each greater than 1, they do no-t have a common divisor other than 1, and the product of the two terms is equal to the total number 1 combinations desired.

of combinations desired. Thus it is not necessary to limit the invention to gear driven rotating members. To cite another example, consider the number 2016 which represents the number of 5 minute intervals in a period of one week. A suitable set of speeds for the two rotating members will be found to be 1/160 r.p.m. and 1/315 r.p.m., respectively. The reciprocals of these speeds are in the ratio of 160:315. This ratio is reduceable to the ratio 32:63.

So far the discussion has been'limited to the consideration of only two rotating members. However, the principle can be extended to'cover any number of members as the occasion requires. lt is only necessary to choose different speeds for the rotating members ex- 1 pressed as a fraction such that the reciprocals thereof are in the ratio of x:y:z: :n wherein all of the terms are greater than 1, no two of the terms of the ratio have a common divisor other than 1, and the prod-uct of all the terms is equal to the total number of If gears are employed then the above ratio represents the gear ratio as well.

Selecting as an example the number of minutes in a week (10,Q80) there will be found several solutions among which are 32:35z9 and 32:45z7. These relationships are preferred instead of, for example, the ratio 631160 which is also a solution. in this case the member represented by the term would have to be too large.

The invention will be better understood, however, after reading the following detailed description with reference to the accompanying drawing, in which:

Figure 1 is a vertical elevation with portions broken away, of the rear of a clock unit showing the actuator mechanism in detail and representing one embodiment of the invention;

Figure 2 is a top view of the clock unit shown in Fig ure 1;

Figure 3 is a fragmentary elevational View of the rear of a clock unit showing a modification of the structure of Figure 1;

Figure 4 is a detail view of an indexing member or` rotatable cam which forms a part of the invention embodied in the structures shown in Figures 1 to 3;

Figure 5 is a fragmentary detail View in section showing a portion of the actuator mechanism; and

Figure 6 represents a fragmentary portion of a typical setting chart to be used in conjunction with the mechanisms shown in Figures 1 to 5.

Referring to Figures 1 and 2 of the drawings there are shown the details of a program clock capable of being pre-set to close a switch as often as fifteen times during a twenty-four hour period. The unit comprises two rectangular frame plates 10 and 11 fastened together at their four corners and maintained in spaced parallel relationship by the spacing sleeves 12. A suitable timekeeping mechanism in the form of an electrically operated synchronous clockmotor 13 is secured to the plate 11 and coupled through a conventional train of gears to the clock hands 14 and 15. A clock face 16, having appropriate indicia thereon, is secured behind the hands to the plate 1G. The hands in cooperation with the face 16 provide the usual time indicating means.

A pair of driven or spur gears 17 and 18 are secured to hubs 24 and 25, respectively, and mounted for rotation on the posts 2S and 29, respectively. This is best seen. in Figure 5. The posts, in turn, are secured to the plate 11. Retaining rings 30, 30 having a diameter slightly less than the diameter of the hubs are located at the ends of the posts 2S and 29 to prevent removal of the gears.

In order to interrelate the driven gears with the timekeeping mechanism a driving member in the form of a driving gear or pinion 20 is secured to the shaft 19 in mesh with the spur gears 17 and 13. The shaft 19 is journaled in the plates 10 and 11. In addition to the pinion 20, two other gears, 21 land 22, are mounted on shaft 19. As shown, these gears are located between the plates 10 and 11 and form part of the gear train between motor 13 and the hands 14- and 15. The gear 22 is keyed or otherwise secured to shaft 19 while gear 21 is only frictionally secured thereto by spring member 23. The free end of shaft 19 is square-shaped to receive a setting key of suitable construction. In the alternative, a knob could be permanently secured to the end of shaft 19. This arrangement provides the usual means for pre-setting the hands of the clock to coincide with the actual time of day.

In the twenty-four hour clock presently under discussion it is desired to provide 1440 operating points, i.e., at one Iminute intervals. Therefore, gears 17 and 1S are provided with 64 and 90 teeth, respectively, i.e., in the ratio of 32:45. Since these gears are required to complete one full cycle in twenty-four hours they must rotate at speeds of 1/32 r.p.m. and 1/5 rpm., respectively. This is achieved by providing pinion 20 with 32 teeth and causing it to rotate at 1/16 rpm. As previously explained, the gears 17 and 1S could have 32 and 45 teeth, or 96 and 135 teeth, respectively, for example. The iinal choice is controlled by design convenience. From a practical standpoint it is desirable to arrive at a compromise between keeping the number of rotating members at a minimum and keeping the number of index points on a given member at a minimum.

In order to indexV or define the diiferent combinations of positions of the spur gears 17 and 18 there are provided a plurality of indexing members 31 and 32. Indexing member 31 is shown in detail in Figure 4. It comprises a thin disc or rotatable cam provided with operation controlling means in the form of a notch or indentation 36. A plurality of small indexing apertures are arranged in a circle concentric with the center of the disc which is also apertured. The small indexing apertures are equally spaced around the disc and individually identified by the letters A to AH. Any other suitable indicia may also be employed. It will be noted that 32 such apertures are provided and the notch 36 is adjacent the aperture A.

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The indexing members 32 are similar to the members 31 except they are provided with 45 equally spaced apertures which are identiiied by the numerals 1 to 45. In this case the notches 37, as seen in Figure 1, are adjacent the aperture 1.

One or more of the discs 31 can be located on hub 24 separated from each other by spacers 33, 33. In order to maintain a desired indexed position of cam 31 relative to gear 17, the latter is provided with a locating pin 26 which is arranged to receive one of the lettered apertures en the discs 31. The locating pin effectively establishes a point of reference on the gear. The spacers 33 are discshaped and suitably provided with a single aperture adjacent the periphery to receive the locating pin 26. In similar manner one or more of the discs 32 can be located on hub 25 engaging the locating pin 27 which is secured to gear 18 and separated one from the other by spacers 34. For a reason which will be mentioned below the spacers 325 and 34 are provided with slightly larger diameters than the diameters of the respective indexing members 31 or 32.

As best seen in Figure 5, the plurality of cams and spacers are held tightly together against the respective gears 17 or 18 by any suitable clamping means such as the collar 3S held in place by a set screw.

Considering a pair of indexing members 31 and 32 it can be appreciated that there are 1440 different combinations of letters and numbers. Since any lettered or any numbered aperture, `as the case may be, can engage the corresponding locating pin there are 1440 combinations of relative positions between the cams 31 and 32. lt is arranged that each combination represents a predetermined minute during a twenty-four hour period.

As one means of determining the combination which corresponds to a particular minute there is provided a chart or tabulation, a corner of which is shown in Figure 6. The tabulation has been arbitrarily begun at 12:00 noon with that time represented by the combination A1. The next minute, 12:01, is represented by 132, 12:02 by C3 and so forth until after 1440 minutes or combinations it recommences at A1 With the desired number of cams pre-set on the hubs 24 and 2S, it is necessary to provide means for providing the required output when the cams assume the preselected positions relative to each other. To this end there are provided a plurality of cam followers each in the form of a double-acting pawl 38 pivotally mounted on a post 39. The latter is secured to the plate 11. As shown in Figures l and 2, the pawl ends 0f the followers 38 are urged against the peripheries of the indexing cams 31 and 32 by means of a flat multifurcated spring 40. The spacers 33 and 34 serve to conne the pawls to the proper cams. The non-furcated end of the spring is provided with a loop which serves to pivotally mount it on post 41 which is, in turn, fastened to plate 11. The multifureated end of the spring engages the separate followers 38 and is adjustable as to tension by means of a set screw 42 threadedly supported in a post 43 on plate 11.

Means for operating an output switch in response to operation of any one of the cam followers 38 is provided in the form of an operating lever 44 pivotally mounted on the post 45. The lever 44 is retained on the post by the retaining ring 46. A portion 47 of the lever 44 is arranged to operate the button 4S of the microswitch 49, the switch 49 being secured to the plate 11. The pair of rotating members, the set of followers 38, and the lever 44 may be thought of as an actuating mechanism for the switch 49.

The operation of the embodiment described above will now be readily understood. Referring to Figure 1 it will be seen that as the clock operates and pinion 29 drives the spur gears 17 and 18 of the indexable elements, the notches 36 and 37 of the indexable means 31 and 32 will simultaneously align themselves with the corresponding pawls of follower 38. At this moment the follower 38 will drop into the recesses under the urging of spring 40 and cause lever 44 to pivot clock- Wise about post 45. This, in turn, urges the portion 47 against button 48 to operate switch 49 and close he connected circuit which may take any well known orm. v

As illustrated in Figure l, disc 32 is indexed at point l while disc 31 is indexedat point A. With regard to the latter, it should be noted from Figure 4 that the notch 36 is located 'adjacent the aperture A. Referring to the 'chart of Figure 6 it will be observed that A1 represents 12:00 noon. Therefore the clock hands 14 and 15 should now be pointing to 12:00 oclock noon. It follows `as an obvious conclusion that the locating pins or reference points on the spur gears 17 and 18 must bear a predetermined relationship with the clock hands and thus be correlated, when the hands are properly pre-set, to the actual time of day. If the clock face covers only the conventional twelve hours, then some means will be included to indicate when the clock is operating in its am. phase and when it is operating in its p.m. phase. If desired, the clock face may cover the full 24 hours. d

With aperture B of disc 31 and aperture 2 of disc 32 engaging their respective locating pins, the notches 36 and 37 will each be advanced one step in the clockwise direction from the locating pins 26 and 27. lf the gears 17 and 18 rotate in the counter-clockwise direction at the requisite speed, both notches will again engage the pawls after an interval of one minute. This agrees with Figure 6 which shows B2 to represent 12:01 p.m. Thus the actuating mechanism comprising the controlled membersl7 and 18 and the indexable cams 31 and 32 can be pre-set in a novel manner to operate at any minute within an interval of 24 hours. With fifteen sets of cams set on the clock along with l:fifteen followers the switch 49 will be operated fifteen times during the 24 hour period. Of course the posts 28, 29 and 39 can yb'e suitably extended to accommodate more than f'teen cam pairs. In such case it may be necessary to extend the captive ends of the posts through plate 11 to be staked to plate 10.

For proper results the width of the notches 36 and 37 shouldv be slightly less than the peripheral arc between adjacent indexing apertures. By suitable design the pawls on the follower 38 can be given an appreciable dwell period to ensure operation of the load device. A dwell of ve to ten seconds is not impossible.

Theoretically a maximum of 32 disc pairs are needed on a 24 hour-1 minute interval clock in order to provide any number of operations up to 1440. This follows from the fact tha'tdisc 31 has 32 positions and disc 32 can be provided with more than one notch. For instance, if the times 12:05 p.m., 2:45 pm., and 3:01am. are considered, the combinations are F6, F31prand F2 and thus only one disc pair is needed; an F dis'c and three notches in the other disc located opposite the appropriate apertures so that they will occupy positions relative to the locating pin corresponding to 2, 6 and 31. The follower 38 will drop onmthis disc pair three times during a 24 hour period.

In Figure 3 is shown a modification of the structure of Figure 1 with an On-Off microswitch 50, having both an On button k51 and an Off button 52. Instead of the single lever 44 of Figure l, there are now two levers 53 and 54 pivotally mounted on post 4S. Instead of the one type of follower lever 38, there are now two types, 55 and 56. The dilerence between followers 55 and 56 and follower 38 is the provision of the cutouts or recesses 57 and 58. In Figure 3 the VOn lever has just dropped and the On button 51 has been depressed. It can be seen that cutout 57 bridges the contact bar of lever 54 and thus avoids operating the latter. During the one minute interval immediately present invention is susceptible of substantial modication to accommodate itself to various requirements of use. in the following paragraphs an attempt will be made to outline a few possibilities by way of suggestion.

ln many cases a program clock is required to operate more than one circuit. In present program clocks the number of circuits is somewhat limited because there must be independent drums or disc setups for that purpose. In the present invention, however, each impulse is handled separately and independently from the others, each lever 38 may be made to operate a separate switch or contact or they might operate in groups a switch or contact using for each group a lever like 44 in Figures l and 2. The group levers can then be pivotally secured to the same post (eg. 45) and a series of switches (eg. 49) can be mounted on top of each other.

A weekly period program clock can be constructed using the rotating ratios as described above. However, since in many cases the signals will be the same every day but Saturday and Sunday, a calendar disc may be included driven by a 24 hour cam and arranged to switch off certain ones of the followers (eg. 3&5) and, if necessary, place into operation other followers on Saturday and Sunday.

Various types of relays may be used with the mechanism for different purposes such as a time delay relay to ring bells during a desired short time interval. An On-Oii relay can be used where the first impulse of the program clock is t0 be used to close the circuit and the second impulse is to open the circuit. This will adapt Figure 1 to provide the same results as Figure 3.

Further modifications may be made in connection with the discs 31 and 32 and followers 38. in the illustrated embodiment the energy to operate the switch 49 is obtained from the spring 40. If desired, the spring can be eliminated and the motor energy used directly to operate the switch. This, however, will decrease the accuracy of the clock.

The discs 31 and 32 may be provided with pins, or notches having different shapes from those shown in the drawing. If pins are employed, the follower can be in the form of a straight lever having its midpoint coupled to the output switch. This arrangement will operate when both ends of the lever are raised simultaneously by engagement with the pins on the discs.

The discs 31 and 32 and their spacers 33 and 34 can be formed as an integral unit from a thin sheet of metal, the middle portion and the notch being pressed out. In order to locate these discs the locating pins may be n eliminated and replaced by a hub provided with a key.

The diameter of the hubs would also be increased. The discs 31 and 32 would then be provided with a centerhole having internal teeth for receiving the key, instead of the indexing apertures, and the identifying indicia would be appended to each internal tooth. K

Numerous other modifications besides those already described will readily occur to those skilled in the art and it is therefore not intended to limit the invention to the precise embodiments shown and described but all suitable modiications and equivalents may be readily resorted to.

What I claim is:

1; A program clock having a timekeeping mechanism, rheans for providing an output effect, and an actuating mechanism for actuating said means for providing an oliitput effect at pre-selected instances in time during a cycle of operation within a given time interval, said cycle of operation recurring indefinitely during continuous operation of said timekeeping mechanism; said actuating mechanism comprising a plurality of independently indexable elements coupled to said timekeeping mechanism for controlled rotation at different speeds expressed as a fraction such that the reciprocals thereof are in the ratio of :c1yzz: :n wherein all of the terms of the ratio are greater' than 1, no two of the terms of the ratio have a common divisor other than 1, and the product of all the terms is equal to the total number of pre-selectable instances within said given time interval, whereby said elements continually assume different positions relative to one another, said elements being indexable to define a plurality of said relative positions equal in number to said product, means for establishing a correlation between said indexable relative positions and the actual time of day with each indexable relative position corresponding to a different actual time within said given time interval, and means cooperating with said indexable elements and said means for providing an output effect for actuating the latter when said elements assume a pre-indexed relative position corresponding to a pre-selected time.

2. A program clock according to claim 1, wherein each of said indexable elements comprises a controlled member coupled to said timekeeping mechanism for controlled rotation, and at least one rotatable cam having means for detachably securing it to said controlled member in a given number of pre-selectable relative equi-angular positions, the number of said pre-selectable positions being equal to the term of said ratio which corresponds to the indexable element of which said cam forms a part.

3. A program clock according to claim 2, wherein each of said indexable elements comprises the same number of said cams, and wherein said means cooperating with said indexable elements comprise a set of cam followers equal in number to the number of cams included in a single indexable element, each cam follower being constructed to simultaneously engage one cam in each of said indexable elements, each cam in a particular indexable ele ent being engaged by a different cam follower, whereby operation of a cam follower is predicated upon said indexable elements simultaneously attaining predetermined positions relative thereto.

4. A program clock according to claim 3, wherein said means for providing an output effect comprises means responsive to operation of any one of said cam followers for controllinty an electrical switch device.

5. A program clock according to claim 3, wherein said means for providing an output effect comprises first and second electrical switch means, means responsive to operation of any one of some of said cam followers for controlling said tirst electrical switch means, and means responsive to operation of any one of the remainder of said cam followers for controlling said second electrical switch means.

6. A program clock according to claim 1, wherein there are two of said indexable elements and the reciprocals of their speeds of rotation are in the ratio of 32:45.

7. A program clock according to claim 1, wherein there are two of said indexable elements and the reciprocals of their speeds of rotation are in the ratio of 32:63.

8. A program clock according to claim 1, wherein there are three of said indexable elements and the recinrocals of their speeds of rotation are in the ratio of 32z35z9.

9. A program clock according to claim 1, wherein there are three of said indexahle elements and the reciprocals of their speeds of rotation are in the ratio of 32:45:7.`

10. A program clock having time indicating means, a timekeeping mechanism coupled thereto for driving said indicating means so as to manifest the actual time of day when properly pre-set, means for pre-setting said indicating means, means for providing an output effect, and an actuating mechanism for actuating said means for providing an output effect at pre-selected instances in time within a given time interval; said actuating mechanism comprising a plurality of independently indexable elements coupled to said time indicating means for controlled rotation in time therewith, said elements being coupled to be rotated at different speeds expressed as a fraction such that the reciprocals thereof are in the ratio of xzyzz: :n wherein all of the terms of the ratio are greater than 1, no two of the terms of the ratio have a common divisor other than 1, and the product of all the terms is equal to the total number of pre-selectable instances within said given time interval, whereby said elements continually assume different positions relative to one another, said elements being indexable to define a plurality of said relative positions equal in number to said product and each relative position corresponding to a different time within said given time interval, and means cooperating with said indexable elements and said means for providing an output effect for actuating the latter when said elements assume a relationship which has been pre-indexed with reference to said preset indicating means to correspond to a pre-selected time.

ll. A program clock having a timekeeping mechanism, means for providing an output effect, and an actuating mechanism for actuating said means for providing an output effect at pre-Selected instances in time within a given time interval; said actuating mechanism comprising a gear train having a driving gear operatively associated with said timekeeping mechanism, and a pair of cooperating driven gears having a gear ratio of x:y wherein both x and y are greater than l and the product of x and y is equal to the total number of pre-selectable instances within said given time interval, whereby said driven gears continually assume different operative positions relative to one another, means for establishing a correlation between said different operative positions and the actual time of day, indexable means coupled to said driven gears for dening a plurality of said operative positions equal in number to said product, and means cooperating with said indexable means and with said means for providing an output effect for actuating the latter when said driven gears assume a pre-indexed operative position corresponding to a preselected time.

12. A program clock according to claim 11, wherein said indexable means comprise at least one rotatable cazn for each driven gear having means for securing it to the corresponding driven gear in a given number of selectable relative equi-angular positions, the number of said selectable positions being equal to said x or said y depending upon whether the driven gear to which it is secured has nx or ny teeth, respectively, where n is a positive integer, and wherein said means cooperating with Said indexable means comprise at least one cam follower operatively associated with a cam in each indexable means for actuating said means for providing an output effect when said cams assume predetermined positions relative to said cam follower.

References Cited in the file of this patent UNITED STATES PATENTS

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