US2592047A

US2592047A - Clock operated perpetual calendar

Info

Publication number: US2592047A
Application number: US150929A
Authority: US
Inventors: Lind John
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-03-21
Filing date: 1950-03-21
Publication date: 1952-04-08
Anticipated expiration: 1969-04-08

Description

A ril 8, 1952 J. LIND CLOCK OPERATED PERPETUAL CALENDAR 5 Sheets-Sheet 1 Filed March 21, 1950 John Lind INVENTOR. BY @4040 MM Mvm Fig. 2

April 8, 1952 J. LIND CLOCK OPERATED PERPETUAL CALENDAR 5 Sheets-Sheet 2 Filed March 21, 1950 John L ind INVENTOR.

April 8, 1952 J, LIND 2,592,047

CLOCK OPERATED PERPETUAL CALENDAR Filed March 21, 1950 5 Sheets-Sheet 5 April 8, 1952 J. LlND CLOCK OPERATED PERPETUAL CALENDAR 5 Sheets-Sheet 4 Filed March 21, 1950 John Lind INVENTOR- 4013;.

April 8, 1952 J. LlND 2,592,047-

CLOCK OPERATED PERPETUAL CALENDAR Filed March 21, 1950 5 Sheets-Sheet 5 Jab); Lind INVENTOR.

BY M

Patented Apr. 8, 1952 CLOCK OPERATED PERPETUAL CALENDAR John Lind, Newberg, reg., assignor of one-half to A. E. 0tis,'Newberg, Oreg.

Application March 21, 1950, Serial No. 150,929

12 Claims. 1

This invention relates to clock operated perpetual calendars and it has for its main object to provide a simple mechanism with a relatively small number of parts working with the least possible friction which may be driven practically by an ordinary clock mechanism, such as a clock mechanism currently manufactured, the indication of said calendar mechanism being perpetually in accordance with those of the calendar as long as the clock operates.

Clock-operated calendars have been repeatedly proposed but on account of the differences in the number of days for the months of a year and also on account of the difference between ordinary years and leap years most mechanisms must either be manually corrected or readjusted every year or every four years or else the mechanism is involved and includes a very large number of parts. This fact not only raises the cost of manufacturing the perpetual calendar but also makes it difiicult to operate the calendar by means of an ordinary spring operated clock or by an electric clock, such as commonly manufactured, as such clocks develop very little power and therefore cannot drive complex additional gear mechanism in addition to their own gears without getting out of order.

One of the main features of the invention consists in providing a perpetual calendar with a monthly date indicator and a week day indicator and month indicator which are all driven directly or indirectly by a pawl and ratchet mechanism, operated in the same way Whatever the length of the month and which is capable of advancing the monthly date indicator at the end of the month for a number of steps which correspond to the number of days through which this indicator has to be advanced in the shortest month in order to complete a cycle which is based on the longest month which indicator, during the ordinary operation performed during the month and at the end of a month with thirty-one days is prevented from advancing the mechanism for more than one step while at the end of other months a special mechanism adjusting the preventive action is made operative in such a way that an action covering a plurality of steps results.

A still further feature of the invention consists in adjusting this preventive action by means of a member the position of which is in its turn adjusted by the shape of guiding faces for said member allotted to each month on the indicator and connected with the month indicator, the shape of the said guide faces changing in accordance with the length of each month so that a display of the proper month indicia by the month indicator also entails the change of the monthly date indicia at the end of the month and at the correct date correspondin to the number of days in the month displayed.

A still further feature consists in providing a member changing the shape of one of the guide faces adjusting the preventive action and connected with the month of February in leap years, said member being also operated by the operation of the month indicator.

A still further feature of the invention consists in making the pawl and ratchet mechanism of the monthly date indicator from which most other motions are derived operative for different lengths byproviding a ratchet wheel driving pawl moved always to the same extent and guide pawl for said ratchet wheel driving pawl which keeps the latter out of engagement with the ratchet wheel for a portion of its stroke, the guide pawl being withdrawn from operative engagement withthe ratchet wheel driving pawl at the end of the month to a varying extent, thus permitting an advance of the ratchet wheel by the ratchet wheel driving pawl to an extent which permits the pointer to pass over the monthly date indicia which are not .valid for a given month in a single step which is a multiple of the steps performed during the month.

A still further feature of the invention consis-ts in making the guide pawl operative by supporting its endon a rotating drum connected with a shaft, during the monthly date indicator shifting, the drum being provided with cut portions, permitting the guide pawl to withdraw its guiding surface to a varying extent.

A still further feature of the invention consists in regulating the operation of the guide pawl by a shifting movement of the same bringingit within reach of cuts of different lengths, said regulation being obtained by aguide member cooperating with a notched disk connected with the month indicator, the absence or presence of notches and the varying depth of the notches of said disk regulating the movement of said guide pawl.

A still further feature of the invention consists in a leap year mechanism regulating the eifective depth of one of the notches by means of a regulating pawl and cam driven by the movable indicator and effective at every fourth revolution of the month indicator.

The invention is illustrated by way of example in the accompanying drawings showing one embodiment thereof. It is however to be understood that this embodiment is merely shown in order to explain the principle of the invention and the best mode of applying said principle. The embodiment shown is therefore not to be regarded as the sole embodiment of the invention and modifications of the said embodiment do therefore not necessarily form departures from the essence of the invention.

In the drawings:

Figure 1 is an isometric View of the perpetual calendar according to the invention, the figure showing mainly the front side.

Figur 2 is an elevational view of the perpetual calendar with the casing being shown in section the view being taken from the rear.

Figure 3 is a plan view of the perpetual calendar mechanism.

Figure 4 is an elevational rear view of said mechanism on an enlarged scale.

Figure 5 is an elevational side view of said mechanism the view being taken from the left side of Figure 4.

Figure 6 is another elevational side view of the mechanism the view being taken from the right side of Figure 4.

Figure '7 is an elevational sectional view through the mechanism the section being taken along line in Figure 3.

Figure 8 is a fragmentary elevational view of part of the dial and of the Sunday indicating mechanism.

Figures 9, 10, 11 and 12 are partial views showing only the elements regulating the number of steps to be performed at the end of the month in order to advance the monthly date indicator for the required number of steps, the three views showing the position of the parts in months of difierent lengths, Figure 9 showing the position of the parts in a thirty day month, Figure 10 the position of the parts in a thirty-one day month, Figure 11 the position of the parts in a twenty-nine day month and Figure 12 showing the position of th parts in a twenty-eight day month.

Figures 13, 14 and are views of the pawl and ratchet mechanism advancing the monthly date indicator and show the parts in different positions at the end of the month, Figure 13 showing the position on the last day of a month. having thirty-one days, Figure 14 showing th position of the parts at the end of a month having twentynine days and Figure 15 showing the position of the parts at the end of a month having twentyeight days.

Figure 16 is a view of the pawl and ratchet mechanism such as shown in Figure 14 but showing the position of the ratchet wheel driving pawl in the moment when it starts to leave the guide pawl, the position at the end of the stroke being indicated in dotted lines.

Figure 17 is a plan view of a detail showing the ste ped out out portion in the drum and the relative positions of the guide pawl and of the ratchet wheel driving pawl.

Figure 18 is a pers ective View of the guide pa l shifting mechanism and of the mechanism for oper t g t e obturator plate.

Figure 19 is a perspective view of the calendar drive shaft with its arms.

The general arrangement of the automatic clock driven perpetual calendar is shown in Figures 1 and 2. From these figures it will be seen that the clock and the calendar mechanism may be arranged side by side within a casing 20 which houses the entire structure. The front of the casing is covered by a front plate 2| into which circular windows 22 have been cut displaying the clock dial 23 and the calendar indicator dial plate 24.

The clock 25 may be of any type and may be a mechanically or electrically driven clock, the sole adaptation which has to be performed in connection with the usual twelve hour clock consisting in the addition of a gear with a 1:2 ratio (not shown) and shaft 26 driven from the hour shaft which produces a turning of the shaft 26 once every twenty-four hours. On this shaft 26 a snail shaped cam 28 is mounted adapted to cooperate with a cam lever 36 carrying at its nd a roller 3| bearing against and rolling on the cam surfaces. The cam lever turns the shaft 32 on which another lever 33 is fixedly mounted so as to move with the shaft. This lever is connected by means of a rod or wire 34 with a lever 35 on the calendar mechanism. This lever 35 is keyed to a shaft or sleeve 36 or is provided with a square bore fitting on a square pin or projection projecting from the said shaft or sleeve.

The sleeve 36 may be termed the calendar drive shaft as the motion of all parts is derived from it. This sleeve supports a long weighted lever 31 at the end of which a weight 38 is attached. A torsion spring 83 (Figs. 3 and 19) the end of which bears against a fixed member provides the torque for driving the perpetual calendar mechanism whenever the lever 30 and roller 3| is tripped releasing the spring action.

The sleeve 36 in addition carries two further levers or

arms

63 and 93 which will be described below. It may be mounted on a pintle or axle 39 held in a manner which will be described and it is provided with the above mentioned coil spring 63. The weight 38 acts as an equalizing and emergency drive means, equalizing the spring action which decreases when the coiled spring unwinds itself.

It will be clear that the snail shaped cam 28, the lever 3!], the shaft 32, the lever 33, the wire 34 and. the operating lever 35 on sleeve 36 serves the purpose of slowly lifting the weight and of tensioning spring 83 during a twenty-four hour period during which the roller 3| rolls along the outer surface of the snail shaped cam 28, the roller 3| being pushed outwardly in a radial direction. At a given moment, for instance at midnight, the roller 3| however overruns the end 21 of the snail shaped cam 28 and moves inwardly releasing the spring and permitting the weight to come down, thus moving operating lever 35 towards the right in Figure 2. The

movement of the operating lever 35 produces all the movement of the perpetual calendar mechanism.

The perpetual calendar mechanism is mounted on a base plate 46 and it comprises a monthly date indicator, the day of the week indicator and a month indicator which indicators, in the exnecessary indications or figures corresponding" to the monthly date. As months may have thirty-one, thirty, twenty-nine or twenty-eight days the annular scale has a window 4'! through which, that portion o of the annular. scale.v which which is ,di'splayed. and also according to the;

year as. the, indications for February in. leap years. differfrom those in other years.

On the, outer. circumference of the annular dialf46ja Sunday indicator in the-form ofa ring I52; may be arranged which is provided. with projecting tonguesor markers 49 pointing towards those figures which indicate the monthly date of the-Sundays of the month; Merely the" markers or.tongues 49 are visible the ring I52 carrying. them being concealed behindthe scale plate or a special holding'ring.

Five tongues or, markers 49 are provided as there maybe five Sundays in a month, but preferably the fifth tongue 5! is distinguished in some way by color or'shape so that it is easily recognizable, as this tongue will not countwhen pointing. to a. day at theibeginning of, the month.

The monthly date'mechanism with its'indieating pointer, 44 is driven by a shaft 45 passing through and supported by the'base plate 40, which shaft projects toward the rear and is supportedv by a: bracket 57 mounted on

spacer spindles

58, 58a projecting from the base plate 40-;which spindles are substantially parallel'with the-shaft.- The bracket 51'may be securedon the'spindles58, 58a by means of threaded-pins 59 projecting; from the spindles andpassing through holes in the bracket and by means of nuts secured to the threaded'pins.

The shaft 45 is provided at its end with a milled head 52 permitting rotation of the shaft by hand for adjustment purposes. To this shaft 45a ratchet wheel 54 is keyed or otherwise secured which is provided with thirty-one ratchet teeth. A cylindrical drum member 55 is secured to and projects axially from the said ratchet wheel 54; This drum member is'provided with a stepped out portion BUcutt-ingacross the part of the actual'length of'the drum, the purpose of'which cut portion may be described later.

The ratchet wheel 5'4 is moreover provided with a-huhmember Bl located within and surrounded by the drum 56 which hub member is provided'at its end'farthest from the ratchet wheel with a snail shaped'canifiit'best seen in Figures 13, 14 and 15'.

The ratchet wheelEfiis driven by a driving pawl 55which has the shape of a paddle-and whichisof the same width or is 'widerthan; the combined actual width of the ratch wheel and of the axially projecting drum member'fi'; The paddle shaped pawl 65' is mountedon' a pawl carrying curved lever 55 pivotally mounted'on an arm 63 which, as abovedescribed; forms one of "the anns-projectingfrom the sleeve 35 which actuated bythe clock bymeans of the clock actuating lever-35:

Thesleeve- 35' or-the axle 39" supporting it may be journaled or-held in substantial parallelism with the shaft-ddby; the baseplate 40 "and the'bracket 51.

Itwillbeclear that u-pona movement'of'the wire 34 -lifting the weight .38 the calendar driving -sleeve -or shafted-and the arm 63 projecting from it" will be" moved? away from the. ratchet wheeliand in a: clockwisedirection'inFYlgure 4,

while upontripping-of the cam lever- 30 followed by the dropping ofthe weight 38" the calendar drive shaft 36 is turned counter-clockwise in Figures: 2' and 4 and accordingly the paddle shaped'pa-wl-65; the pawl carrying lever 55 and the'arm 63 are movedtowards the ratchet' wheel 541 From Figure-l it will also be-clear that nor mally during the month and at the endof a" month with thirty-one days the-ratchet wheel has to be-advanced fora single step corresponding 'toa single-tooth of the wheel, while at the end'ofithemonththe number of steps differ-in accordance with the number of days of the month and" moreover themovement over a pluralityof stepsstarts at" different dates. In monthswith thirty'days; for instance, the advance of the pointer and of the ratchet wheel starts-when the pointer is two steps off thepositionmarking the first of. the next month and the movement of the ratchet wheel and. of; the-pointer must therefore include an arc corresponding to two steps ofithe' pointer such as made during the month; This corresponds to an advance over two teeth' of the ratchet wheel. In the-month of Februaryin an ordinary year the pointer-has to cover four steps at the end of'the month and the'movement of the pointer-starts onthe 28th; thus requiringvan advance" of the pointer'and of the ratchet wheel through: four steps or four teeth respectively. Ina leapyear' on the other hand the advance'inFebruary covers'threesteps of: the pointer and starts when the pointer has reached the 29 mark; The ratchet wheel inthis case-has toibe advancedfor three teeth; Inorder to provide such a. variable advanceof the ratchet wheel'the pawlgcarrying-lever 55- and the arm 63" always moves through. an. arc which: corresponds to; an advance of the'ratchet wheel for the'maximumnumber of teeth (4) which has'to be performed; but" in order to performonly the required advance of the ratchet wheel corresponding tovone tooth or. to a numberof-teeth which is-smaller than four the paddle shaped pawl-65 moveson a guide pawl 10 which during the-advance of "the-pointerprevents pawl SS-from engaging the teeth of theratchet wheel during part' Ofthis movement. During the; advanceof the pointer fromone monthly date'toanother during the month and during the advanceof the-pointer at the end 'Of,a month having. thirtyonedays theguide pawl H! is so positioned that the movement of the pawl 65 alon the said "guide pawl corresponds, to anadvance through three teeth of ,the ratchet wheel so' that when the pawl finallyengages the ratchetzwheel. the. latter is only advanced for a singletooth;

The guide-pawl l0 is-carried bya guide rod 1 I 'whichis integral with and projects from sleeve or pintle Tipivotallyheld'in eyes 13 of brackets 14 which arermounted on'the base plate." 40: and which-project from said plate at aright angle therefrom and in substantial parallelism with the

spacing spindles

58, 58a; The guide arm or rod l'l inits turn is provided with an enlargement carrying the pin on which a roller. 76 turns. This roller cooperates with'a notched. disk $0 rotatable around an axis which is parallel with the base plate 40.

The guide. pawl 10 is connected with its rod 11 by means of 'a-coi-Lspring H which produces anelastic tension havingthe tendency to move the guide pawl Tiltowards the guide rod: However, during operationthe-guide pawl "lil'issup ported by the dru-m member -55-ax-ially projecting from the ratchet wheel 54 and is thereby kept in proper position in which it will serve as a guide for the paddle shaped ratchet pawl 95 during the larger portion of its advance towards the ratchet wheel. As long as the guide rod I9 therefore rests on the outer surface of the drum 56 the pawl 95 rides on the guide pawl I9 for the major part of the stroke which is made by the arm 63 and the pawl carrying lever 55 and that portion of the stroke which is left when the paddle shaped pawl 65 leaves the guide pawl 19 can only advance the ratchet wheel for a single tooth. As above stated, the drum member 59 has a stepped out portion 69, cutting through a portion of its axial length only. The arcuate length of the cut portion varies step by stepwise with the distance from the ratchet wheel. Therefore, upon a transverse or axial movement of the guide pawl I9 in an axial direction along the drum, such as produced by notches of varying depth in the disk 89 the guide pawl will be moved to a position in which it will meet cut portions of different lengths upon the rotation of the drum member and ratchet wheel. With the guide pawl sliding on the drum, each cut portion makes it unsupported. If the cut portion is of sufiicient arcuate length it may be completely unsupported or it may be supported in a position which differs from that in which it is supported when its pointed end rests on the drum. The paddle shaped ratchet pawl 95 therefore may ride on the guide pawl I9 either along of its stroke or, if the guide pawl has been shifted, along a shorter distance which depends on the position which the guide pawl I9 has assumed when riding over the cut portions. It is thus seen that the guide pawl may regulate the effective stroke of the lever 55 and the paddle shaped pawl 95 at the point at which the guide pawl meets the cut portion of the drum and which corresponds to the day at which the Pointer is to be advanced for more than one step. It will moreover be clear that by providing three steps in the cut portion corresponding to three different positions of the pointer and by leaving one portion of the drum uncut it is possible to provide at the end of the month an advance of the ratchet wheel either for one tooth or for any number of teeth up to four teeth.

In order to keep the ratchet wheel in its position an ordinary detent 61 may be provided which is fixed on the bracket 57 and which is pressed toward the ratchet wheel by a coil spring (not shown). Also in order to limit the advance of the ratchet wheel and to check the forward movement which may be larger than intended a. projecting tooth 99 on the arm 63 is provided which engages the teeth of the ratchet wheel when the desired movement has been performed.

In order to keep the roller I6 on guide rod II permanently in operative engagement with the notched disk 99 whatever the depth of the notches in the disk and also in order to operate the obturator plate 48 the spacer spindle 58 carries an upwardly projecting pivot pin 84 which by means of sleeve 85 supports a rockable bell crank lever 99. Roller I9 is mounted by means of pin I on the rod II and is notched to engage the edge of cam disk 89. One of the arms of the bell crank lever is provided with a lug 91 to which a spring 88 is attached and which is secured on the other side to a post 39 carried by the spacer spindle 58. The bell crank lever .99 is thus permanently spring tensioned. One of the arms 99 of the bell crank lever presses against the guide rod II and thus keeps the roller I9 of the guide rod 1I permanently in contact with the notched disk 89.

The second arm 92 of the bell crank lever 86 is provided with an eye 9| into which one of the bell crank lever 86 is provided with an eye 9I into which one of the bent ends 94 of a. connecting rod or wire is hooked, the other bent end 96 of the said rod 95 forming a pin entering a pin hole provided in an eye of the straight portion of an arm 91 which actuates the obturator plate 48. The upper portion 99 of said arm is rounded and arch like so as to link the straight lower portion of the actuator arm with the obturator plate 48 which is arranged behind the dial in the front plate. The obturator plate actuator arm 91 is provided with an eye or sleeve 99 with which it is rotatably mounted on the shaft 45 carrying the date pointer 44. Its movement therefore is a circular movement around the axis of the shaft 45. This movement advances the obturator plate 48 within the window 41 along the annular zone occupied by the date dial 46.

In order to prevent a disengagement of the bent end 94 from the lever arm 92 when the casing 29 should accidentally be turned upside down, a finger II5a is provided extending across the connecting rod 95 preventing its end 94 from leaving the eye 9| of arm 92.

The month indicator essentially consists of a drum I99 of cylindrical or polygonal shape covered with a strip or strips carrying suitable inscriptions. The drum is so arranged that one of the months named appearing on the drum is always displayed behind the window 42 of the dial 24. The window is substantially horizontal and parallel to the base of the housing. The drum must be arranged to rotate around an axis which is also horizontal and which is parallel to the base plate 49. The base plate is provided with suitable cut portions I9I through which said drum projects so that the perimeter of the drum is always in close proximity to the window 42 and dial 24.

The month indicator drum I99 is supported on the shaft I92 supported on a pintle which may itself be rotated and held in brackets I93 projecting from and held by the base plate 49.

The shaft I92 also carries the disk 89 provided with notches I95 which are of varying depth the uncut periphery of the notched disk supporting the roller I6 during those months which have thirty-one days (Figure 10). The months with thirty days (Figure 9) have shallow notches while a deep notch I95a such as shown in Figure 12 corresponds to the twenty-eight days of the month of February. Of course, the disk 89 is so adjusted on the shaft I92 supporting the indicator drum I99 with which it moves that the notch is in position for the reception of the roller I6 when corresponding month indicia are displayed through the window 42.

The shaft I92 is driven at such a speed that it makes one revolution every year. The revolution of the shaft I92 may be used to produce the correct monthly date displayed during the leap year. Manifestly the notch I 95a for February in this case should be somewhat less deep than the notch provided for the month of February in ordinary years, and the guide pawl 19 should lose its support on the drum somewhat later, the pointer having to be moved to the mark 29. In order to reduce the depths of the notch I95 a supporting pawl I9! may be provided on the preferably of-aflarger width than the disk so Ithat'it may be supported by the .pawl I01.

Alternatively the'di'sk may be provided with-a v .recess 'for'the pawl I 01. .The supporting pawl II'is movedby a cam I08 mounted on a stub airle .I'I3 projecting from the disk surfacean'd .carryingagear Wheel I00 which meshes with a gearwheel III which is stationary. .The ratio .oflthe wheelsJII and I09 is'l to 4. The wheel I09 -wil1'there'fore merelyturn around and com- .plete one full revolution onceevery four t-years and will thenbringthe cam I08.into the .po-

sition shown in Figurell in which the support- .ing pawl .I0I reduces the depth'throug'h which theroller "I6 can move.

The guide pawl "I0 will thus .be movedto a portion of the cut in the drum which is shorter than that used during the .month of February of other years and which,

permitsthe dropping of theguidepawl '10 :only at thepoint which di'fiers from that used in 'February of ordinary years.

The advance of the month indicating drum I00 at the first or every month "is produced'by,

means of a further notched disk IIO which is provided with a regular series of notches similar to teeth. .The disk H0 is also .keyed 'to or fixedly connected with the shaft -I02- a'nd the disks .80 and H0 may be arranged atoppositel .sidesof the drum I00. 'The number of regular .ratchet teethnot'ches ion the disk H0 .is equal to.the numberof morithsormay .be a multiple thereof. The disk is advanced by .means ofa .pawl I I2 which isprojecting "from an arm "I I integral with or mounted 'on theendofa spindle or sleeve Ill. 'The said spindle or sleeve is parallel to the shaft 45 and is'held'by thelbase plate 40 and'bythe .depen'dingend 'I'I6a of the T bracket 51.

'.Preferably the pivoted-arm .I'I5.is projecting .jfrom-a sleeve 'II8 surrounding the-spindle I I I .and .the sleeve may be secured .on the .spindle' by .means of a coil spring I28 which-opposes .the

vided at'its end withaproiecting. hand lever I '(Figuref2) by meansof which the pawl I I2 may be operated in order to readjust the calendar should it have-got out of date.

.At the end of .the arm 'I I5 a roller I22 is mounted which runs along the surface of the snail shaped cam 62 forming ,part of the 'hub meniberBI of the ratchet Wheel. "The snail (shaped cam '62, raises the arm I I5.by.moving-the roller outwardly during itsrotation and during the rotation of the ratchet wheel "54 -and inia given: position forinstance .in the. position shown 'in.Figure .13 the .roller I 22 reaches theen'd of the cam surface. .roller I22 snaps inwardly towards the center of him portion 6I under the tension of spring I20 Upon further movement the and "the arm therefore swings downwardly in Figure '4. Thepoint of .the cam where the roller reaches the end ofthe snail shaped 'camis coincldent with the point at whichtheratchet wheel, the shaft and the pointer 44 reachesthe indication'for the 'end o'fthe month. The radial inward movement of tthe roller and the downward movement of the arm -I I5 taking place-when the tmonthly date position-changes and the pointer movesto-the markfor the'first of the'next'month.

b'aseplate 40.

brackets I 31 with small eyes. 35

The notched disk H0 is also provided with a pawl I25 (Figure 5) urged towards it'byspring and held'by the base plate, which pawlprevents any backward movement of the notched disk.

It is alsopreferable to arrange a guard member I23 on 'the arm II5 which drops into'a notch of the notched disk I I0 in orderto check'its forward motion upon actuation of the pawl.

In order to produce an abrupt dropping of arm II5 from the'en'd of the cam asmallpin I24 may be arranged immediately behind the roller I22 on which the arm rests when the'roller'starts to overrun the pointedend of the snail-cam62.

The snail shaped'cam is not only provided with a step butis undercut to a considerable-extent so that it adopts the shape of "a spiral arm. The cut portion permits the guide'pawl todrop into the interior of the drum without coming 'into contact with the cam 62.

'Theweekday indicaton'the indicia of which are displayed through the window 4| of 'the scale plate 24, consists of a'drum I30 held on androtatable with an axle or spindle I32 which'is held in brackets I33 projectingfrom and held'by'the The drum projects through one of the cut portions'IOI of the base plateaiid is so arranged thatit-is'closelybehind'thewindow'4 I "Like drum'I'00 it carries astrip on which the indiciafa're printed and'it'is operated by'a notched disk I35 which'isfixed'to the drum I30 or itol'the axle or spindle I32. The notched disk is driven 'by a pawl'driving lever I36 pivotedto thebase plate 40 the pivot being "carried by The pawl'carrying lever I36is provided with a pawl I40 which engages the notches of the notched disk I35-wh1le a detent I46 which may be carried by the brackets prevents backward movement of the notches of the said notched disk.

In order to check its forward movement the disk is provided on itsflat or end surface with a number of pins-I45 (Figure 6) set in a circle'and a checking pawl I42 on lever I36'moves'into .the path of the circle containing the pins'andthereby preventsthe movement of'the disk beyondthe predetermined arcuate length.

The 'pawl carrying lever I36 in its turn is moved by a linking rod'l50 which is hinged'to lover I 36 at I48 and which is connected atits other end by means of a hook and eye connection witha projectingarm 93 on the calendar driving s1eeve36 which rocks around its axis or around a pintle'39 when the clockactuates the calendar mechanism.

The Sunday indicator is a mechanism WhiChIiS not included in the automatic operation of the perpetual calendar in the example shown. 'The triangular tongues or markers 49 are mountedon a ring I52 by means of another ring'which'is chamfered on the back and which overlaps the ring I52 to hold it inplace. The ring I52'carries teeth I53 on its outer periphery which mesh with 'the'teeth of a pinion I54 carried byan axle I58 which is turned by'means of a sleeve 'I5'I'in'engagement with it. A knob I55 on the sleevel5'I permits to turn the "pinion aroundits axis "thus moving the ring I52 back 'and' forth.

The operation of the device has already been partly described and it is .thereforeonly briefly summarized.

Let it be assumed'that the clock'25 has been wound by means of the winding knob which also serves to adjust "the hands "Of the clock.

.Then the perpetual calendarmust be adjusted, "an operation which must'only be carriedout at the beginning and if the clock has stopped for a day or longer. In the event that the clock has stopped for more than a month then the clock is set for midnight so that the calendar driving shaft 36 is actuated by means of the snail shaped cam 20, the

levers

30, 33 and the wire 34. Then by means of knob 52 the shaft 45 and the pointer 44 is turned to the first of the month. Further by pushing lever I20 up and down the month indicator drum is rotated until the proper month appears in the window 42 of the dial. Then pawl carrying lever 55 and arm 63 is moved back and released as many times as necessary until the proper day of the week appears in the window 4|. Now the pointer 44 may be moved to the proper date of the month.

The leap year mechanism need not be set unless the clock has stopped for more than a year. Should it however be necessary to reset the leap year mechanism the lever I20 is operated until the February with twenty-nine days appears on the dial. Then if the year for which the calendaihas to be adjusted is one year after the leap year for instance, the month drum is turned for one complete revolution and isthen turned to the month which should appear.

After the setting of the perpetual calendar the clock may be turned to the correct hour and the calendar will remain perpetually right.

' 'When the clock trips the lever 30 by means of cam 28 rod or wire 34 moves to the right in Figure 2, and the weight 38 suddenly drops, the calendar driving sleeve 36 with its projecting

arms

63, 93 being turned by the tension of the coil. spring 83. The guide pawl I in the course of the month rests on the cylindrical drum member 56 and the paddle shaped pawl 65 when moved by arm 63 and lever 55 therefore rides on the guide pawl, and leaves it near the end of ,the stroke and pushes the wheel 54 forward for one tooth. The shaft 45 carrying the ratchet wheel 54is therefore rotated for one step and advances the pointer 44 for one step.

Simultaneously the lever 93 moves downwardly and pulls wire I50 thus actuating the pawl carrying arm I36. The weekday drum is thus advanced and the indicia for the following day appear in the'window 4 I.

The advance continues in the same manner until the end of the month is reached. At the end of the month the roller I22 has either reached the end of the cam 62 or is one, two or three steps away from the end of the cam. Should the month be a month with thirty-one days the roller I22 willhave reached the end of the snail shaped cam. For such a month the disk 80 will not be provided with a notch and therefore the roller 16 will roll on the circumference of the disk and the guide rod II and the guide pawl ID are in the extreme position to the left in Figure in which the guide pawl rides on the drum along a strip located in immediate vicinity of the ratchet wheel 54. As this strip is not provided with a cut portionvthe next actuation of the calendar driving sleeve 36 will result in the advance of the pawl 65 along the guide pawl I0 for the major part of the stroke so that the ratchet wheel 54 will again beonly-advanced for a single tooth. The operation for such a month is thus the same as the operation already described for the advance of the pointer during the months.

Should however the month be the month of February, for example, the portion of the disk 80 which faces the roller [6 is the deepest notch I050. The guide rod II and the guid pawl has therefore moved to the extreme right in Figure 12 and the guide pawl rides on the strip near the edge of the drum which is farthest away from the ratchet wheel 54. On this strip of the drum the cut portion extends over the greatest length and the tip of the pawl 10 reaches the edge of the cut portion on the 28th. The roller I22 is still three steps away from the end of the snail shaped cam 62, the position of the cam being indicated in Figure 15. The next actuation of the calendar driving sleeve 36 therefore makes the guide pawl drop as shown in Figure 15, the paddle shaped pawl 65 is no longer guided by pawl I0 and therefore advances the ratchet wheel through an arc corresponding to its full stroke which corresponds to an advance through four steps. The shaft 45 is therefore rotated through four steps and advances the pointer and rotates it past three day marks to the fourth mark corresponding to the first of the next month. The arm 93 however performs only its ordinary motion and advances the week day drum I30 for a single step corresponding to one day by means of wire I50, pawl carrying lever I36 and pawl I40.

It will also be clear that when the guide rod II moved to the right in Figure 12 because roller 16 engaged notch I05a the arm 90 of bell crank lever 86 followed this movement as spring 88 draws the arm 90 towards the guide rod thus producing the necessary pressure to keep the roller in contact with the notches. The second arm 92 of the bell crank lever 86, upon such movement, pulled the obturator plate 48 across the window 41 by moving the arm 91 carrying the obturator plate. The calendar is then set for the month of February.

It will also be seen that when the snail shaped cam 62 is rotated during the advance of the ratchet wheel 54 through four teeth it is moved past roller I22 and therefore the roller I22 and arm I I 5 snaps inwardly. This movement advances the month drum for one step by means of pawl II2. At the end of the month the calendar therefore shows the correct weekday, the correct month and the pointer has been advanced to the mark for the first day of the month.

From the above it will be readily seen that the depth of the notch in the disk rotating with the month drum controls the movements of the monthly date pointer and of the obturator plate by controlling the extent to which the guide pawl I0 is moved to one side or the other.

The leap year mechanism has already been described in detail.

From the above description it will be seen that the mechanism used operates with very little friction, consumes small power and operates with th minimum of moving and intermeshing members. The mechanism is moreover positively acting and is perpetually in accordance with the calendar as long as the driving clock continues to work.

While the invention has been described with reference to a single example it will be clear that the details especially those of an unessential nature may be changed without in any way affecting the operation without departing from the essence of the invention.

Having described the invention, what is claimed as new is:

l. A clock driven perpetual calendar mechanism comprising a clock controlled mechanism operated once every twenty-four hours, a month indicator, a weekday indicator and a monthly dateindicatona calendar drive shaft, connected with and operated by the clock controlled mechanism and performing an angular movement of predetermined extent upon operation, means for linking said Weekday indicator with said calendar drive shaft, a rotary shaft driving the monthly date indicator, means for operating the month indicator,controlled by the said rotary drive shaft and operative at the completion of a full revolution of'the same, means for advancing said rol0 tating monthly date indicator drive shaft step by step, means on the calendar driveshaft for operating the aforesaid advancing means for the rotating drive shaft step by step, step regulating means controlled by the rotating drive shaft for the monthly date indicator for limiting the effective extent of the stepwise advance of the advancing means forthe rotating drive shaft for .the monthly date indicator, an obturator plate for concealing monthly date indications not ex- 'isting in the month indicated by the month indicator and means controlled by said step regulating means for moving said obturator plate.

'2. A clock driven perpetual calendar mechanism comprising a clock controlled'mechanism operated once very twenty-four hours, a month indicator, a weekday indicator nd a monthly date 1indicator,.a.calendar drive shaft, connected with and operated by the clock controlled mechanism :and performing an angular movement of predetermined extent upon operation, means for linkingsaid weekday indicator with said calendar drive shaft, a rotary shaft driving the monthly date indicator, and adapted to perform one complete revolutionin each month, a ratchet wheel. on said rotating shaft provided with a number of teeth proportional to the maximum number of days in a month, a reciprocating ratchet pawl for advancing saidiratchet wheel step by step,

said ratchetpawl being directly connected with 140 the calendar drive shaft and moved by the same throughan angle corresponding to the maximum number of steps through which the said ratchet wheelhas to be advanced atone time to complete its revolution, anadjustable guide pawl for said ratchet wheel advancing .pawl, guiding the said pawl toward thelratchet wheel during aportion of its stroke, thus limiting the. extent of the efiective stroke imparting movement to the. ratchet wheelmeans for adjustingthe position of said guide pawl relatively to the ratchet wheel, in-

cluding a guide member forsaidlguide pawl, a monthindicator, means for operatin the same including controlling means-carried by the ropawl with respect to the latter.

3. A clock driven perpetual calendar mechanism comprising a clock controlled mechanism operated once every twenty-four hours, a month indicator, a weekday indicator and a monthly date indicator,- a calendar drive shaft, connected "with-and operated by the clock controlled mechanism and performing an angular movement of predetermined extent upon operation, means for v linking said weekday indicator with said calendar drive shaft, a rotary shaft driving the monthly "date indicator, and adapted to perform a com- :plete revolution during each month, a ratchet wheel on said rotating shaft provided with a num- :ber :of: teeth: proportional to the. maximum numher of days in a month, a ratchet pawl foradvancing said ratchet wheel step by step, directly connected with and moved by said calendardrive shaft thus performing a reciprocating movement of constant arcuate length, each step of said ratchet wheel during the month advancing the monthly date indicator from one date to the succeeding date, and an angular advanceof variable extent for the different months advancing the monthly date indicator from the last date of one month to the first date of the succeeding month,;a guide drum provided with axially stepped :cuts connected with and moved by said rotating shaft, an adjustable guide pawl for said ratchetpawl, guided and supported during the month ,by said guide drum, but released by the same in different positions and to a different extent in predetermined axial positions of the rotating shaft, :corresponding to the last day of the month, said guide pawl guiding the ratchet wheel advancing pawl during a portion of its stroke toward the ratchet wheel and limiting the extent of the effective residual stroke advancing the ratchet wheel, a month indicator, means for operating thesame including controlling means carried by the rotating shaft and producing operation of said month indicator operating means once during a complete revolution of the rotating monthly date indicator shaft, and regulating means connected with the month indicator for adjusting the-relave axial position of the guide pawl with respect to the guide drum, to adjust the position'of the said guide pawl relatively to the ratchetwheel, so as to make the ratchet pawl which is guided by the guide pawl, operative to advance the ratchet wheel to different extents.

4. A clock driven perpetual calendar as claimed in claim 2 wherein the guide member consists of a cylindrical drum coaxial with the'rotating shaft and provided with cut portions of different arcuate length along different axial sections of the drum and wherein the regulating means con nected with the month indicator comprisecam means for moving the guide pawl in an axial direction along the cylindrical drum.

5. A clock driven perpetual calendar mechanism comprising a clock controlled mechanism operated once every twenty-four hours, a month indicator, a weekday indicator and a monthly date indicator, a calendar drive shaft, connected with and operated by the clock controlled mechanism and performing an angular movement of predetermined extent upon operation, means for linking said weekday indicator with said calendar drive shaft, a rotary shaft driving the monthly date indicator, and adapted to perform one complete'revolution in each month, a ratchet wheel on said rotating shaft provided with a number of teeth proportional to the maximum number of days in a month, a ratchet pawl for advancing said ratchet wheel step by step with a ratchet teeth engaging edge, said ratchet pawl being directly operated by the calendar drive shaft and moved by and with the same through an angle corresponding to the maximum number of steps the said ratchet wheel has to be advanced at one time to complete its revolution, an adjustable guide pawl for said ratchet wheel advancing pawl, guiding the ratchet wheel engaging edge of the ratchet pawl during a portion of its stroke toward the ratchet wheel and limiting the extent of the effective stroke of the pawl advancing the ratchet wheel to the movement performed after engagement of the teeth of the wheel, means for adjusting the position of the guide pawl relatively 15 to the ratchet wheel to vary the effective stroke of the ratchet wheel advancing pawl, a month indicator means for operating the same including controlling means carried by the rotating shaft producing operation of said month indicator operating means once during a complete revolution of the rotating monthly date indicator shaft, means connected with the month indicator for adjusting the position of the guide pawl, said means including a notched disk provided with notches of different depth and a guide pawl carrier provided with a member cooperating with said notched disk and entering and leaving the notches during a revolution of the notched disk moving the guide pawl to different axial positions, and a drum carried by said ratchet wheel provided with axially stepped cuts for guiding the guide pawl, said drum providing an adjustment of the guide pawl after different angular movements of the ratchet wheel in accordance with the axial position of the guide pawl on the said drum.

6. A clock operated perpetual calendar mechanism as claimed in claim 1 wherein the means for operating the month indicator consists of a ratchet wheel driving the month indicator, a

ratchet pawl engaging said ratchet wheel, a pivoted spring pressed lever carrying the said ratchet pawl, a guiding means on the said pivoted lever, and a snail shaped cam supporting said guiding means and mounted on said rotatable monthly date indicator shaft, said cam moving the pivoted lever gradually away from the ratchet wheel during its revolution, but producing a sudden radial inward movement of the guiding means and of the pivoted lever carrying the ratchet pawl at the completion of a full revolution, thus advancing the ratchet wheel and the indicator for one step at the completion of a revolution of the rotating monthly indicator shaft.

'7. A perpetual calendar mechanism as claimed in claim 1 wherein the calendar drive shaft comprises a sleeve under spring tension provided with four arms, one of said arms carrying a weight adapted to move the shaft when released, one of said arms being connected with the clock controlled mechanism by a connecting member, one of said arms carrying and operating the means for advancing the rotating monthly date indicator drive shaft, and one of said arms being connected with the weekday indicator and operating the same.

8. A clock driven perpetual calendar mechanism comprising a clock controlled mechanism operated every twenty-four hours, a calendar dial provided with monthly date indicia arranged in a circle, with a pointer moving along said indicia rotatable around an axis passing through the center of the circle, said dial being provided with a plurality of windows, one of said windows being an annular window covering an arc corresponding to the last indicia of the month, means for carrying the indicia behind the window, a movable obturator plate moving behind said window adapted to cover one or more of these indicia, a further window displaying the week day indicia, a drum carrying said indicia rotatable around an axis parallel to said window and to said dial, a further window displaying the month indicia, a drum carrying the month indicia and rotatable around an axis parallel to said window and to said dial, a shaft driving the pointer extending substantially at right angles to the dial, a calendar driving shaft substantially parallel to the pointer driving shaft, provided with a weighted arm and connected with and operated by the clock controlled mechanism, and performing an angular movement of predetermined extent upon operation, a ratchet wheel on said pointer driving shaft, adapted for stepwise advance and provided with a number of teeth proportional to the maximum number of days in a month, a ratchet pawl for advancing said ratchet wheel step by step, carried on a rockable arm, fixed on the calendar drive shaft, the arcuate movement of the said ratchet pawl being equal to the maximum number of steps through which the said ratchet wheel has to be advanced at one time to complete its revolution, an adjustable guide pawl for said ratchet pawl, guiding the latter during a portion of its stroke and preventing engagement of the ratchet pawl with the ratchet wheel during this portion of the stroke, said guide pawl being carried by a pivoted lever, means connected with the month indicia carrying drum for adjusting the position of the guide pawl carrying pivoted lever, means connected with the pointer driving shaft for adjusting the position of the guide pawl, both said means cooperating in determining the effective position of the guide pawl relative to the ratchet pawl and ratchet wheel, a ratchet wheel connected with the month indicia carrying drum, for advancing said drum in a step by step manner, a pawl operated by the pointer shaft for advancing the ratchet wheel of the month indicia drum for one step for each revolution of the pointer shaft, a pawl and ratchet mechanism connected with the weekday indicia drum, means for operating said mechanism connected with the calendar driving shaft, and means for shifting the obturator plate, said means being controlled by the pivoted lever of the guide pawl.

9. A clock driven perpetual calendar as claimed in claim 5, comprising in addition a two armed bellcrank lever, a spring for keeping the same under tension, one arm of the bellcrank lever pressing against the guide pawl carrier thus keeping the same in engagement with the notched disk, an obturator plate arranged near and forming part of the monthly date indicator for covering monthly dates not existing in a month displayed by the month indicator, an operative carrier arm for said obturator plate rotatable around the rotatable monthly date indicator driving shaft, and a connecting link between said obturator plate carrier arm and the second lever of the bellcrank lever.

10. A perpetual calendar mechanism as claimed in claim 1, wherein the weekday indicator and the means for linking the same to the calendar drive shaft comprise a drum carrying weekday indicia, rotatable with a shaft, a disk with ratchet teeth on said shaft, a ratchet pawl mechanism including a plurality of pawls, a pivoted arm carrying said pawls, a series of pins projecting from said disks and arranged in a circle at regular intervals, one of said pawls engaging the ratchet teeth of the disk, the other engaging the projecting pins, an arm projecting from the calendar drive shaft, and a linking member connecting the end of the projecting arm with the free end of the pivoted pawl carrying arm of the week indicator.

11. A calendar mechanism as claimed in claim 8 comprising in addition a movable ring surrounding the calendar dial markers carried by said ring and projecting towards the monthly date indicia for indicating Sundays, a toothed segment carried by said ring, a pinion meshing 17 with said toothed segments and hand operated means for turning said pinion so as to set the Sunday markers on the correct dates for the month displayed.

12. A clock driven perpetual calendar mechanism as claimed in claim 1 wherein the clock controlled mechanism comprises a snail shaped cam driven by the clock at a rate of one revolution for every twenty-four hours, a spring pressed lever mechanism having one arm applied against the snail shaped cam, a second lever arm on said lever mechanism, an arm connected with and projecting from the calendar driving shaft, a rigid link connecting said last named arm with the second lever arm of the lever mechanism, a 15 weighted arm on the calendar driving shaft, and a coiled spring for imparting an angular movement to said calendar driving shaft.

JOHN LIND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 173,572 Andrews Feb. 15, 1876 704,916 Peatfield July 15, 1902 799,679 Shirk Sept. 19, 1905 10 2,170,408 Hillcourt Aug. 22, 1939 FOREIGN PATENTS Number Country Date 346,935 Germany Jan. 11, 1922