US3685280A

US3685280A - Manual setting mechanism for digital alarm clock

Info

Publication number: US3685280A
Application number: US151187A
Authority: US
Inventors: Wolfgang Fehrenbacher
Original assignee: Kieninger and Obergfell GmbH and Co
Current assignee: Kieninger and Obergfell GmbH and Co; KUNDO KIENINGER and OBERGFELL
Priority date: 1970-06-11
Filing date: 1971-06-10
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22
Also published as: FR2096778A7; FR2096778B4; DE2028679A1; IT987539B

Abstract

An alarm clock with coaxial digit wheels for 1-minute, 10-minute and hour indications has a pair of contact-carrying disks, rotatable about the same axis, mechanically coupled with the 1minute wheel and with the hour wheel, respectively, for entrainment thereby. Each disk confronts an associated selector drum bearing minute and hour indications, respectively, these disks being independently settable to display the time when the alarm is to ring. Each drum consists of insulating material and carries a terminal of an alarm circuit positioned to engage a contact near the periphery of the associated disk whenever the latter occupies a position corresponding to the selected drum setting; the disks are always conductively interconnected, by a contact spring on one disk engaging a metallic track on the other disk, so that the alarm circuit is completed when both disks occupy their preselected positions. To set the time, the disks are independently steppable by toothed actuators manually reciprocable in a slotted guide plate; a swingable detent interposed between the two lower order digit wheels prevents the resiliently indexable 10-minute wheel from overshooting its next position in response to a too rapid stepping of the 1-minute wheel through the associated disk.

Description

United States Patent Fehrenbacher MANUAL SE'ITING MECHANISM FOR DIGITAL ALARM CLOCK Wolfgang Fehrenhacher, St. Geor gen, Black Forest, Germany KUNDO Kieninger &. Obergfell Fabrik fur Technische Laufwerke und Apparate, St. Georgen i/Black Forest, Germany Filed: June 10, 1971 Appl. No.: 151,187

Inventor:

Assignee:

Foreign Application Priority Data June 11, 1970 Germany ..P 20 28 679.1

US. Cl ..58/38, 58/19 R, 58/225, 235/1 C, 58/125 C Int. Cl ..G04c 21/00, G04c 21/16 Field of Search....58/38, 19 R, 19 A, 125 R, 125 C,58/I26 R, 126 E,22.5,85.5,16 R; 235/] C References Cited UNITED STATES PATENTS Primary Examiner-Richard B. Wilkinson Assistant Examiner-Stanley A. Wal AttorneyKarl F. Ross [57] ABSTRACT An alarm clock with coaxial digit wheels for l-minute, 10-minute and hour indications has a pair of contactcarrying disks, rotatable about the same axis, mechanically coupled with the l-minute wheel and with the hour wheel, respectively, for entrainment thereby. Each disk confronts an associated selector drum bearing minute and hour indications, respectively, these disks being independently settable to display the time when the alarm is to ring. Each drum consists of insulating material and carries a terminal of an alarm circuit positioned to engage a contact near the periphery of the associated disk whenever the latter occupies a position corresponding to the selected drum setting; the disks are always conductively interconnected, by a contact spring on one disk engaging a metallic track on the other disk, so that the alarm circuit is completed when both disks occupy their preselected positions. To set the time, the disks are independently steppable by toothed actuators manually reciprocable in a slotted guide plate; a swingable detent interposed between the two lower order digit wheels prevents the resiliently indexable 10-minute wheel from overshooting its next position in response to a too rapid stepping of the 1-minute wheel through the associated disk.

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PATENTED I912 3.685.280

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J d {Ross Attorney MANUAL SETTING MECHANISM FOR DIGITAL ALARM CLOCK My present invention relates to a timepiece such as an alarm clock as disclosed in commonly owned application Ser. No. 101,974 filed by Gunter Hummel and Erich Scheer 28 December 1970. Such a timepiece may be used, aside from alarm purposes, for timing a photographic exposure, for reading a laboratory instrument, or for carrying out any other operation beginning and ending at precisely predetermined instants.

More particularly, my invention concerns a preferably electrically driven timepiece of the digital type, Le. a clock with a set of operatively interconnected digit wheels displaying time indications of a different denominational orders in a window of a housing, such as the units and tens digits of the minutes and corresponding numerical values for the hours.

The system disclosed in the aforementioned copending application includes two contact carriers and two rotary selectors coaxially juxtaposed therewith, each selector being independently settable to any one of a multiplicity of angular positions in which it is retained by friction or by suitable indexing means. The two contact carriers, which are preferably disk-shaped and will be referred to hereinafter as disks, are positively linked with the lowest ranking and a higher ranking digit wheel of the display unit, respectively, generally the 1- minute wheel and the hour wheel. As the rate of rotation of the disk entrained by the hour wheel is an aliquot fraction of the rate of rotation of the disk entrained by the 1-minute wheel, the latter will perform several (usually 12 or 24) full revolutions per operating cycle while the former makes only one turn in the course of such cycle. Only once per cycle, therefore, will the two disks simultaneously occupy predetermined positions relative to the associated selectors in which coacting contacts on the two disks and the two selectors establish a connection to complete an external load circuit including, for example, an alarm device. The time of occurrence of such a relative position depends, of course, on the presetting given to the two selectors which are advantageously calibrated in minutes and hours, respectively. Thus, the alarm will go off at exactly the instant when the hour and minute settings of the selectors match the digital reading of the clockwork, the circuit being broken as soon as the parts move out of that relative position. If the clockwork is conventionally stepped so that its reading changes only once per minute, the coincidence position and therefore the operation of the alarm will last for exactly 1 minute. Such a stepping drive, causing successive jumps of each digit wheel or reel by one division, is well known in decimal counters or registers; it may include a single tooth on an input member periodically engaging the gear coupled with the digit wheel, a stepping pawl controlled by an electronically pulsed balancer, or a Geneva movement.

While for alarm clocks it will generally be sufficient to span a period not greater than 24 hours, this period could evidently be extended to, say, a week or a month by a modification of the time base of the controlling digit wheels and/or by the inclusion of a further selector and disk in series with the two mentioned above, this further disk being entrained by a digit wheel of still higher denominational order counting, for example, the number of days.

ln order to facilitate mass production of the parts, the two carrier disks advantageously are of identical basic construction including each a body of dielectric material with conductive facings on opposite surfaces and with throughgoing metallic connectors therebetween; one of the facings of each disk, on the side remote from the other disk, forms part of a contact spring projecting axially toward the associated selector which also has an insulating body formed with a peripherally located discontinuity in its insulation, the contact spring engaging this discontinuity once per revolution to extend the circuit. The discontinuity may be simply a hole through which a contact spring can reach an underlying conductive surface, but in a preferred construction it is constituted by a metallic rivet with a first head contacting such a surface and a second head engageable by the contact spring of the disk. The metallic facings on the two confronting disk sides are designed to provide a permanent conductive connection between the disks, one of these facings having the shape of an annular track while the other facing forms a contact spring engaging that track in any relative position of the two disks.

The general object of my present invention is to provide simple and conveniently operable means for manually advancing the several digit wheels for altering their time indications, more particularly for separately setting their minute and hour readings, independently of the associated electric motor or other prime mover serving for their automatic displacement.

A more specific object is to provide a compact assembly of manual controllers for the adjustment of both the digit wheels and the associated contact carriers to set the time and to select the desired alarm position, these controllers being readily accessible without requiring the opening of the clock housing or the removal of any parts.

In accordance with the instant improvement, I provide separate stepping means respectively engageable with the two contact carriers for selectively advancing same together with the associated digit wheels, advantageously against the force of indexing means yieldably retaining each digit wheel in any one of its several indicating positions, by preferably one indicating position at a time. Thus, the hour wheel may be stepped in increments of either 15 or 30 whereas the 1-minute wheel, entraining the 10-minute wheel can be rotated through 36 with every stroke of the associated stepper. These steppers, according to a more particular feature of my invention, are designed as a pair of sliders reciprocably guided in a slotted plate and provided with working formations, such as sets of sawteeth, positioned to engage the toothed peripheries of a pair of rotary bodies respectively coupled with the two contact carriers for joint rotation. While these rotary bodies could be integral with the two carrier disks, it is generally more convenient to design them as pinions of substantially smaller diameter meshing directly or indirectly with the tooth peripheries of these disks.

In order to enable unidirectional stepping of each carrier disk, each slider is advantageously made of two interfitted parts, one of them resting against a surface of the slotted guide plate whereas the other carries the sawteeth and is movable relatively to the first-mentioned part, in a direction transverse to the plate surface, against the biasing force of a spring (preferably a curved leaf spring) during the return of the slider from its offnnormal to its normal position.

With the 1-minute wheel driven (preferably stepwise) by the prime mover, motion is transmitted from it through the IO-minute wheel to the hour wheel with the aid of coacting projections on confronting sides of the several digit wheels. Advantageously, the interdigital transmission stages are recessed in concave sides of the coaxial, equal-diarneter l-minute and hour wheels, with the smaller IO-minute wheel centered on an axis parallel to the common axis of the two larger wheels and with the distance between these axes approximately equaling the difference of the wheel radii whereby the digit-carrying peripheral portions of these wheels lie substantially in a common plane within the display zone exposed by a window in the clock housing. As the coacting lateral projections of the digit wheels move in orbits which coincide only in the vicinity of this common plane, each higher order wheel is entrained by the immediately preceding lower order wheel only once per revolution of the latter and over a fraction of a circle. Nevertheless, if the 1-minute wheel is manually stepped at high speed in the coupling position of the two minute wheels, the 10-minute wheel could be impelled with excessive force so as to skip its next indexed indicating position. To avoid such overstepping, I prefer to interpose between the two minute wheels a pivoted stop member which is normally biased into a blocking position in the path of the several entrainable projections of the lO-minute wheel but is momentarily deflected into a nonblocking position, by the driving prohection of the 1-minute wheel, at the instant of operative coupling of the two minute wheels.

Since it may be necessary at times to advance the hour wheel without concurrently rotating the minute wheel, the driving projection of the 10-minute wheel (on the side thereof confronting the hour wheel) is advantageously designed as an overrunning-clutch type coupler by being mounted on a spring-loaded lever, giving clearance to the lateral projections of the hour wheel upon reversal of the normal relative rotation of the two wheels.

The above and other features of my invention will be described in detail hereinafter with reference to the accompanying drawing in which:

FIG. 1 is a front-elevational view (with parts broken away) of a digital clockwork provided with an alarm mechanism according to my invention;

FIG. 2 is a bottom view of the assembly of FIG. 1;

FIG. 3 is an enlarged sectional elevation of the alarm control stage of the assembly of FIGS. 1 and 2;

FIG. 4 is a side view of the assembly of FIG. 3;

FIG. 5 is a bottom view of that assembly;

FIG. 6 is an exploded perspective view of the digit wheels and associated couplings of the clockwork of FIGS. 1 and 2;

FIG. 7 is a side view of an intermediate digit wheel, as seen in the direction VII of FIG. 6;

FIG. 8 is an enlarged bottom view of a component also seen in FIG. 5;

FIG. 9 is a side view of a slider forming part of the component of FIG. 8;

FIG. 10 shows the component of FIG. 8 from the opposite side; and

FIG. 11 is a view similar to FIG. 9 but showing the component in section and on a larger scale.

In FIGS. 1 and 2 I have shown parts of the housing of an electrical digital clock including a bracket 1 with two

upstanding anns

2, 3. This housing has a window, not shown, for displaying the time of day (here 16:36 hours or 4:36 PM) in the form of digits carried by three

coaxial wheels

4, 5 and 6. Digit wheel 4, bearing the numerals 0 to 9, and digit wheel 5, bearing the numerals 0 to 5, show the minutes; digit wheel 6 displays the hours with the aid of eight peripherally mounted prismatic bodies of which three, designated 8, 9 and 10, are visible in FIG. 1. These bodies are in the form of regular three-sided pyramids provided, as shown in the copending application referred to, with star wheels each carrying three angularly spaced pins engageable by a fixed stud in a stationary end cap ll secured to arm 2. Reference in this connection may also be made to commonly owned application Ser. No. 32,660 filed Apr. 28, 1970 by Oskar Obergfell and Giinter Hummel. now US. Pat. No. 3,616,642. Thus, during any revolution of wheel 6, any

digit carrier

8, 9, 10 etc. is tripped on passing through its nadir position and rotated through to exhibit a new face to the observer; these faces, 24 in all, carry the numerical designations from O0 to 23. Naturally, the 24 hour readings could also be designated 1 AM to 12 AM and 1 PM to 12 PM. Each digit carrier may be held in its position relative to wheel 6, for a full revolution of that wheel, by friction or with the aid of indexing means not shown.

Bracket 1 supports, via posts 13 and screws 14, a similar, smaller bracket 15 having

upstanding arms

16 and 17. The arm 3 of bracket 1 is broadened to serve as a mounting plate for a motor 22 and other parts of the stepping drive, the motor having a base 31 supported on plate 3 by posts 21. Two further mounting

plates

33, 34 are secured to plate 3 by means of mounting bolts 32 surrounded by tubular spacers 35.

Mounting

plates

33 and 34 define a compartment for a unit, more fully illustrated in FIG. 3, which controls the closure of an alarm circuit including a power source 201, a bell or buzzer 202, and a manual circuit breaker 203 assumed to be closed. This circuit is connected across a pair of binding posts 55, 55' fixedly held in mounting

plates

33 and 34, respectively. These mounting plates are provided with a pair of fixed coaxial sleeves 41, 42 which receive

gudgeons

43, 44 of an axle 40 and which carry a pair of fixed but resiliently deformable indexing plates 49, S0 of insulating material provided on their confronting surfaces with conductive annular zones 51, 51'. The sleeves 41 and 42 further receive

hubs

45, 46 of a pair of insulating

selector elements

37 and 36, respectively, which are generally cup-shaped with outwardly facing concavities embracing the

indexing plates

49 and 50. The

elements

37 and 36, which will be referred to hereinafter as drums, have

end walls

53, 54 each formed near its periphery with an annular array of corrugations 56, 56' engaged by the rounded extremity 57 or 57' of the associated binding post 55 or 55', the latter being secured to the corresponding

indexing plate

49, 50 whose resiliency tends to maintain the extremities 57 or 57 in engagement with the corrugated surface 56 or 56'. The corrugations of this surface are as numerous as the angular settings of the corresponding selector drum,

namely 24 in the case of the

hour drum

36 and 60 in the case of the minute drum 37. To facilitate the manual setting of either drum, their outer peripheries are provided with

gear teeth

60 and 61. Posts 55 and 55' are in conductive contact with the metalized

zones

51 and 51 of

plates

49 and 50, respectively, which are engaged by proximal heads of

rivets

52, 52 traversing the

drum walls

53 and 54, respectively.

As illustrated in FIG. 3, the outer surface of drum 37 carries hour markings (here ranging from O0 to 23, in conformity with those of digit wheel 6) while drum 36 is similarly provided with minute markings (ranging from O0 to 59). It will be convenient, as shown, to write out only the even-numbered indications and to replace the odd-numbered ones by lines, dots or the like. These 24 scale divisions of

drum

37 and 60 scale divisions of drum 36 can be observed through a viewing slot of the housing and/or read against an arrow or other marker alongside each drum showing the exact hour and minute to which the two drums have been set.

Two

disks

38, 39 are sandwiched between the

drums

36, 37 and are also freely rotatable on the axle 40. The two disks have identically shaped bodies of insulating material, preferably a thermoplastic resin, and are respectively coupled with l-minute wheel 4 and with hour wheel 6 for entrainment thereby. Thus, disk 38 performs exactly one revolution per hour whereas disk 39 makes one revolution every 24 hours. The latter disk, juxtaposed with drum 37, carries a contact spring 79 bearing upon the outer surface of drum wall 53 along an orbit which includes the rivet 52 so that the electric circuit from terminal 55 is extended to disk 39 whenever this disk and the drum 37 are in a predetermined relative position, i.e. the position in which the hour reading of the drum corresponds to that displayed by the digit carriers 8 etc. of wheel 6. In an analogous manner, disk 38 carries a contact spring 81 on its side facing the drum 36, the latter spring bearing upon the outer surface of drum wall 54 to make contact with the rivet 52' thereof in a relative position in which the minute reading of the drum corresponds to that displayed by the

digit wheels

4 and 5. Rivet 52 and spring 79 are so dimensioned and positioned that their area of contact extends over less than and is limited to a single operating position of disk 39 for any indexed position of drum 37; in an analogous manner, the area of contact of rivet 52 and spring 81 extends over less than 6 and is also limited to a single operating position of disk 38 for any indexed position of drum 36. Disk 39 is further provided with a conductive annular track 83 continually wiped by a contact brush 80 on the inner surface of disk 38; with

springs

80 and 81 conductively interconnected and with spring 79 also permanently connected to track 83, spring 79 lies always in circuit with spring 81 so that the load circuit 201 203 is completed whenever spring 79 contacts the rivet 52 at the same time that the spring 81 engages the rivet 52'.

The

rivets

52 and 52 represent discontinuities in the insulation of their respective drums and, in a simplified system, may be replaced by openings in the drum wall through which the free ends of the contact springs 79 and 81 can reach the conductive zones 51 and 51', respectively, whenever the disk position matches the settings of the associated drums. Such a simplification, reducing the contact resistance, is particularly advantageous with low-voltage power supplies, yet the interposition of the rivets affords greater precision.

The transmission linking

digit wheels

4 and 6 with

disks

38 and 39, respectively, includes a shaft 66 extending parallel to the wheel axis, this shaft being journaled in an upturned extension 68 of bracket 1 and in the mounting plate 33. A gear on shaft 66 is in mesh with the toothed periphery of wheel 6 while a pinion 69 on the other end of that shaft drives a gear 77 keyed, together with a pinion 78, on a sleeve 76 freely rotatable on another shaft 73 spanning the

plates

33 and 34. A similar sleeve 70, freely rotatable on shaft 66, bears a gear 71 in mesh with the toothed periphery 64 of wheel 4 and terminate in a pinion 72 meshingwith a gear 74 keyed to shaft 73. Disk 39 has a toothed periphery 62 in mesh with pinion 78 whereas disk 38 also has a toothed periphery 63 in mesh with a similar pinion keyed to shaft 73. This gear train provides a step-down ratio of 24 m (i.e. 3 1 for the torque transmission from wheel 6 to disk 39, the latter being thus stepped once per hour through an angle of 15, and provides a step-down ratio of 6 1 between wheel 4 and disk 38 whereby this disk is advanced every minute through an angle of 6. Thus, the load circuit of FIG. 3 is closed once per 24-hour period for exactly 1 minute; naturally, this load circuit may include a holding relay or other timing means for either foreshortening or exte nding the operating time of the alarm 202.

The positive coupling of the

digit wheels

4 and 6 with the

disks

38 and 39, respectively, via transmission 66 79 translates any manual adjustment of these disks into a corresponding displacement of the corresponding wheels. The means for making this adjustment, as well as the interstage coupling mechanism for converting the periodic stepping of wheel 4 by motor 22 (at 1- minute intervals) into less frequent advances of

wheels

5 and 6, will be described hereinafter with reference to FIGS. 4 11.

Digit wheels

4, 5 and 6 are rotatably joumaled on three fixed

shafts

19, 18 and 7, respectively, all parallel to the transmission shaft 66. Shaft 7 extends between

uprights

2 and 16; shafi 18 spans the

arms

16 and 17 of bracket 15 which lie within the concave sides of the two

hollow wheels

6 and 4, confronting the intermediate wheel 5, while shaft 19 is secured to

uprights

17 and 3 in line with shaft 7. The two aligned shafts 7 and 19 are offset from shaft 19 by a distance equal to the difference between the radii of the two larger wheels 4, 6 (which are of like diameter) and of the smaller wheel 5 whereby the centrally disposed faces of the polygonal peripheries of the

wheels

4, 5 and 6 as viewed in H6. 1 (constituted in the case of wheel 6 by an exposed prism face such as that of prism 9) are coplanar in their display position. Since the number of faces of

wheels

4 and 5 are 10 and six, respectively, the ratio of their radii is approximately 5:3; this afi'ords sufficient clearance to accommodate the bight portion of bracket 15 adjacent wheel 5 within the confines of

wheels

4 and 6.

Wheel 5 is also laterally recessed, as seen in FIGS. 6 and 7, so as to have two overhanging

rims

111, 136 corresponding to a rim on the concave side of wheel 6 and a similar rim on the confronting face of wheel 4. The spaces framed by rim 100 of wheel 6 and by the corresponding rim of wheel 4 serve to accommodate indexing means constituted, in the case of wheel 6, by a ratchet 101 normally engaged by a pawl 103 which is swingable about a fulcrum 104 and has its free end 105 stressed by a tension spring 107 anchored at 106 to the body 102 of the digit wheel. The analogous indexing mechanism for wheel 4 has not been illustrated, yet its counterpart on wheel 5 has been shown in FIG. 7 to comprise a ratchet 117 rigid with shaft 18 and a pawl 121 pivoted to the wheel at 119, its free end 120 being stressed by a spring 116 anchored at 115 to an escapement lever 1 13 with a fulcrum 1 12. The free end 1 14 of lever 113 is integral with an axially extending projection or dog 110, having a transverse face 119 and a beveled face 120, which is normally held by spring 116 against the inner peripheral surface of rim 111 so as to lie in the path of a set of co-operating projections 109 of wheel 6 formed as internal ribs on the rim 100 thereof. Similar projections 130, in the shape of prismatic studs, extend axially from the inner periphery of rim 136 of wheel 5 into the concave side of wheel 4 for coupling engagement with a single dog 131 fixed within that side to the rim of the latter wheel. In conformity with the number of active faces of

wheels

5 and 6, ratchets 117 and 101 have six and eight teeth, respectively; similarly, there are eight projections 109 on the former wheel and six projections 130 on the latter wheel.

Thus, in view of the relative eccentricity of the orbits of

projections

130, 131 and 109, 110, wheel 5 is stepped once per revolution of wheel 4 through an angle of 60 whereas the wheel 6 is advanced once per revolution of wheel 5 through an angle of 45. The primary stepping drive for wheel 4 includes, besides the synchronous motor 22, a gear train 23-30, 30;, 30b; if this drive comprises a stage with position immobilization of the load, such as a Geneva motion, the aforementioned indexing mechanism for digit wheel 4 may be omitted.

The presence of lever 113 has the effect of an overrunning clutch by permitting the hour wheel 6 to overtake the IO-minute wheel 5 on being manually rotated (counterclockwise as viewed in FIG. 7) to change the hour indication, with the projections 109 camming aside the projection 110 by bearing upon the beveled face 120 thereof if the latter projection happens to lie between the two foremost ribs 109', 109" of wheel 6 as illustrated in FIG. 6, i.e. if wheel 5 occupies the 50- minute position in which its next step would advance the wheel 6 from, say, the l l-oclock to the l2-oclock position.

Thus, regardless of the relative positions of the several coupling projections, the positions of the two

minute wheels

4 and 5 will remain unaffected by any adjustment of hour wheel 6 so as to eliminate the need for any subsequent readjustment of the minute indications. On the other hand, a manual advance of 1- minute wheel 4 may also step the lO-minute wheel 5 and possibly the hour wheel 6, in the same way as does the automatic drive.

In view of the play afforded by the indexing mean 117, 118 and 101, 103, the range of positive entrainment of wheel 5 by wheel 4 and of wheel 6 by wheel 5 may be somewhat less than 60 and 45, respectively, inasmuch as the force of loading springs 116 or 107 will in such case complete the rotation of the follower wheel through the desired angle. If, however, the user applies excessive force to the l-minute wheel 4 in turning it past the carry position (illustrated in FIG. 6) in which dog 131 engages the next projection of wheel 5, the latter could be propelled past its next indexing position so as to overshoot its desired setting. To prevent this, I prefer to interpose between the wheels 4 and 5 a stop member 132 in the form of a yoke with two arms 133, 134 straddling the shaft 18 of wheel 5, this yoke having a hole 132 traversed by a pivot pin (not shown) in the recessed side of wheel 4 so as to be limitedly swingable between an operative position and an inoperative position. In its operative position, into which the yoke 132 is urged by a spring 137 anchored to it at 138 and tied to the body of wheel 4 at 139, an axial extension 141 of arm 133 lies in the path of a stud 130' so as to block the advance of the wheel 5; a transverse extension 140 of arm 134 lies in a zone beyond the ends of studs 130. As the dog 131 approaches the stud 130" to be entrained, it engages the extension 140 so as to deflect the yoke 132 in a clockwise sense into a non-blocking position to clear the stud 130', yoke 132 returning immediately to its normal position with the continuing advance of dog 131 so that extension 141 intercepts the next-following stud of wheel 5 at a point where pawl 121 is effective to index that wheel for a proper centering of its exposed digit in the viewing window. This positive limitation of the advance of intermediate wheel 5 to a single step also prevents any possible overstepping of hour wheel 6. An abutment 142 integral with bracket arm 17 arrests the stamped or molded yoke member 132 in its normal position by engaging its arm 133.

FIGS. 4, 5 and 8 11 show details of the manual stepping means for

wheels

4 and 6. A guide plate with a pair of parallel slots 156, 156', transverse to the wheel axes, is secured to mounting

plates

33, 34 with the aid of indentations 151, 151' and slots 152, 152' of plate 150 receiving projections 188, 188' and tabs 187, 187' of these mounting plates, two hook-shaped lugs 186, 186' on the latter plates engaging edges 184, 184' of recesses 185, 185' formed at the lower comers of plate 150 as viewed in FIGS. 8 and 10 (see also FIG. 2). Two sliders 155, are respectively guided in slots 156, 156' for manual reciprocation, each of these sliders consisting (as particularly illustrated for slider 155) of an outer part 153 and an inner part 154 snapfitted together. As best seen in FIG. 11, part 153 has a T-profile with a stem 162 and a bar 159 having a milled surface 160, T-bar 159 being constituted by a raised portion of a strip 158 which rests flat against the outer surface of guide plate 150 and spans the slot 156 thereof; corresponding elements of slider 155' have been designated 158', 159'. Stem 162 is formed with a pair of bosses 165 received, with play, in recesses of two jaws 164 of part 154 bracketing that stem, part 154 being of sufficiently resilient material (metal or plastic) to facilitate the snap interfitting of the two parts within a cutout of strip 158. Jaws 164, passing together with stem 162 through guide slot 156, form a web integral with a flange of part 154 projecting laterally beyond that slot, this flange being formed with sawteeth 163 positioned to engage a set of peripheral teeth of sleeve 76 integral with pinion 78 (cf. FIG. 2); the corresponding sawteeth of slider 155' are engageable with similar teeth 174 on an extension of pinion 75. A curved leaf spring 173, also bridging the slot 156, has a central slot traversed by the web 164 so as to bear upon the flange portion of part 154 in an inward direction (arrow A, FIG. 11), i.e. in a sense tending to reduce the clearance 161 between web 164 and T-bar 159 so as to hold the sawteeth 163 in line with the coacting teeth 175, these latter teeth being advantageously undercut as shown in order to maintain their engagement with teeth 163 when the slider 155 is moved upwardly in the direction of arrow B. Upon the subsequent return stroke, the sloping edges of

teeth

163 and 175 drive the part 154 outwardly against the force of spring 173 into the position shown in FIG. 1 1 (which, however, will not normally exist once the slider has cleared the pinion 76 on returning to its rest position against the direction of arrow B). Reverse rotation of

pinions

75, 78 is prevented by friction and by the aforedescribed indexing means, supplemented if necessary by a pawl-andratchet arrangement (e.g. a modification of indexing elements 101, 103 and 117, 118) permitting only unidirectional movement of the

disks

62, 63 and the digit wheels 4 6 coupled therewith.

Sliders 155 and 155' are biased into their normal retracted positions (i.e. downwardly in FIGS. 8 11) by a transverse arm 167 whose extremities 168, 168' engage in a clearance 169 formed between the two parts of the respective slider. 'I'he midpoint 171 of arm 167 is under tension from a coil spring 166 lodged in a cutout 170 of guide plate 150 and anchored to the lower edge 172 of that cutout; either slider may therefore be moved upwardly, with the limits of the corresponding guide slot 156 or 156', against the restoring force of that spring. The length of these slots is advantageously so chosen that a stroke of the slider 155 rotates disk 39 and hour wheel 6 through a little more than whereas the slider 155' rotates disk 38 and 1- minute wheel 4 through a little more than 6 (as indicated by the somewhat greater length of slot 156 in comparison with slot 156'), enabling each digit wheel to be returned to its proper indexed position by the associated spring'loaded pawl. Thus, the number of manual reciprocations of sliders 155 and 155' determines the number of hours and minutes, respectively, by which the time setting of the clock is to be advanced.

To adjust the alarm position, a pair of milled

wheels

176, 177 are freely rotatable on a shaft 178 spanning the mounting

plates

33 and 34.

Wheels

176 and 177 are inegral with a pair of pinions 1'79, 180, respectively, meshing with

respective pinions

182, 183 on another shaft 181 supported by these plates.

Pinions

182 and 183 engage the

peripheral teeth

61 and 60, respectively, of

drums

36 and 37 which are thus independently rotatable with the aid of these milled wheels. With guide plate 150 mounted at the bottom of the clock frame and the nadirs of

wheels

176, 177 coplanar with the milled surfaces of bars 159, 159', and with the center of gravity of the clock mechanism located above the rectangle defined by these four elements, 176, 177, 159, 159, the latter may serve as supporting legs for the timepiece.

The system herein disclosed allows for manual resetting at any time, even during the stepping of a higher order digit wheel by one of a lower order.

lclaim:

1. A timepiece comprising:

a set of operatively interconnected digit wheels including a first wheel provided with time indications of a relatively high denominational order and a second wheel provided with time indications of a relatively low denominational order;

drive means for rotating said first wheel at a relatively slow rate and said second wheel at a relatively fast rate;

a first contact carrier and a second contact carrier juxtaposed for independent rotation about a common axis;

transmission means positively linking said first and second contact carriers with said first and second wheels, respectively, for rotary entrainment thereby;

first and second stepping means normally disengaged from but respectively engageable with said first and second contact carriers for selectively advancing same together with the associated digit wheels independently of said drive means;

a first rotary selector and a second rotary selector centered on said axis and confronting said first and second contact carriers, respectively, said selectors being independently settable to any one of a multiplicity of angular positions;

retaining means for holding each of said selectors in a chosen angular position;

co-operating first contacts on said first contact carrier and said first selector making in a predetermined relative position thereof;

co-operating second contacts on said second contact carrier and said second selector making in a predetermined relative position thereof;

conductor means maintaining a continuous conductive connection between the contacts on said contact carriers; and

a load circuit including a source of current and a controlled device connected across the contacts of said selectors for actuation of said device upon simultaneous making of said first and second contacts.

2. A timepiece as defined in claim 1 wherein said drive means comprises mechanism for intermittently advancing said first and second wheels through successive indicating positions corresponding to the multiplicity of angular positions of said first and second selector means, respectively, whereby said load circuit remains closed for a period equaling the residence time of said second wheel in any of its indicating positions, each of said digit wheels being provided with indexing means for yieldably retaining same in each indicating position thereof, said stepping means being operable to advance the associated digit wheels by one indicating position.

3. A timepiece as defined in claim 2 wherein said contact carriers are provided with a pair of peripherally toothed rotary bodies respectively coupled therewith for joint rotation, said first and second stepping means comprising each a reciprocably guided slider with a working formation positioned to engage the toothed periphery of the associated rotary body for unidirectionally entraining same upon reciprocation between a normal and an off-normal position.

4, A timepiece as defined in claim 3 wherein said transmission means is provided with a fixed frame,

further comprising a guide plate on said frame having a pair of slots respectively accommodating said sliders.

5. A timepiece as defined in claim 4 wherein each of said sliders comprises two interfitted parts, one of said parts resting against a surface of said guide plate, the other of said parts having a set of sawteeth constituting said working formation and being movable with reference to said one of said parts, in a direction transverse to said surface, against a biasing force for clearing the toothed periphery of the associated rotary body upon a return of the slider to said normal position.

6. A timepiece as defined in claim 5 wherein said other of said parts has a web traversing the corresponding slot of said guide plate and a flange rigid with said web extending laterally beyond said corresponding slot, said web bearing said sawteeth, each slider being further provided with spring means bearing upon said web and said guide plate alongside said corresponding slot to generate said biasing force.

7. A timepiece as defined in claim 6 wherein said one of said parts has a stem inside said corresponding slot and said web comprises two jaws bracketing said stem, said jaws and said stem being provided with interengaging retaining means.

8. A timepiece as defined in claim 7 wherein said one of said parts is formed with a milled ridge carrying said stem.

9. A timepiece as defined in claim 5 wherein said rotary bodies have undercut peripheral teeth engageable by said sawteeth.

10. A timepiece as defined in claim 4 wherein said sliders are provided with resilient restoring means anchored to said plate for tending to maintain each slider in said normal position.

11. A timepiece as defined in claim 10 wherein said slots are parallel to each other, said restoring means comprising an arm generally perpendicular to said slots having opposite extremities in engagement with said sliders and a tension spring attached to a midpoint of said arm.

12. A timepiece as defined in claim 3 wherein said contact carriers are two peripherally toothed disks, said rotary bodies being a pair of pinions respectively meshing with said disks.

13. A timepiece as defined in claim 2 wherein said first and second wheels are of like diameter and centered on said common axis, said digit wheels including a third wheel of smaller diameter centered on a further axis offset from said common axis and interposed between said first and second wheels, said third wheel being provided with time indications of an intermediate denominational order, the time indications of all digit wheels being displayed on peripheral portions thereof lying substantially in a common plane parallel to said common and further axes, said mechanism including a prime mover for said first wheel and coacting projections on confronting sides of said first, third and second wheels intermittently engageable with one another in the vicinity of said common plane.

14. A timepiece as defined in claim 13 wherein said first and second wheels are provided with concave sides facing said third wheel and receiving said coacting projections thereof.

15. A timepiece as defined in claim 14 wherein said tran mission me s is rovided wi a f e frame including an outer rack t spanning a ll sai igit wheels and an inner bracket on said outer bracket received partly in said concave sides and spanning said third wheel, said digit wheels being provided with fixed axles secured to adjoining arms of said inner and outer brackets, said indexing means including co-operating members on said axles and on said wheels.

16. A timepiece as defined in claim 15 wherein said third wheel is provided, on its side confronting said first wheel, with a lever carrying one of said projections and with biasing means normally holding said lever in a position for periodically advancing said first wheel but enabling manual rotation of said first wheel independently of said third wheel under the control of said first stepping means.

17. A timepiece as defined in claim 16 wherein said co-operating members include a pawl on the side of said third wheel confronting said first wheel, said biasing means comprising a spring anchored to both said lever and said pawl.

18. A timepiece as defined in claim 15, further comprising stop means pivoted on said inner bracket in the concave side of said second wheel facing said third wheel and resilient means normally holding said stop means in the path of several projections present on the confronting side of said third wheel for preventing the latter from substantially overshooting an indexed indicating position thereof, a coacting projection in the concave side of said second wheel being engageable with said stop means for momentarily deactivating same upon engagement with any of said several projections to permit the advance of said third wheel.

19. A timepiece as defined in claim 1 wherein said selectors are a pair of peripherally toothed drums, said transmission means being provided with a frame supporting said stepping means, further comprising a shaft on said frame parallel to said axis, a pair of setting wheels for said selectors independently rotatable on said shaft, and gear means positively coupling said setting wheels with said drums.

20. A timepiece as defined in claim 19 wherein said first and second stepping means are a pair of sliders reciprocably guided in said frame for parallel motion transverse to said axis, said sliders and said setting wheels projecting from the underside of said frame at spaced-apart locations in coplanar relationship to form a set of supporting legs therefor.

Claims

1. A timepiece comprising: a set of operatively interconnected digit wheels including a first wheel provided with time indications of a relatively high denominational order and a second wheel provided with time indications of a relatively low denominational order; drive means for rotating said first wheel at a relatively slow rate and said second wheel at a relatively fast rate; a first contact carrier and a second contact carrier juxtaposed for independent rotation about a common axis; transmission means positively linking said first and second contact carriers with said first and second wheels, respectively, for rotary entrainment thereby; first and second stepping means normally disengaged from but respectively engageable with said first and second contact carriers for selectively advancing same together with the associated digit wheels independently of said drive means; a first rotary selector and a second rotary selector centered on said axis and confronting said first and second contact carriers, respectively, said selectors being independently settable to any one of a multiplicity of angular positions; retaining means for holding each of said selectors in a chosen angular position; co-operating first contacts on said first contact carrier and said first selector making in a predetermined relative position thereof; co-operating second contacts on said second contact carrier and said second selector making in a predetermined relative position thereof; conductor means maintaining a continuous conductive connection between the contacts on said contact carriers; and a load circuit including a source of current and a controlled device connected across the contacts of said selectors for actuation of said device upon simultaneous making of said first and second contacts.

4. A timepiece as defined in claim 3 wherein said transmission means is provided with a fixed frame, further comprising a guide plate on said frame having a pair of slots respectively accommodating said sliders.

15. A timepiece as defined in claim 14 wherein said transmission means is provided with a fixed frame including an outer bracket spanning all said digit wheels and an inner bracket on said outer bracket received partly in said concave sides and spanning said third wheel, said digit wheels being provided with fixed axles secured to adJoining arms of said inner and outer brackets, said indexing means including co-operating members on said axles and on said wheels.