WO1988009962A1

WO1988009962A1 - Clock with digital/analog features

Info

Publication number: WO1988009962A1
Application number: PCT/US1988/001921
Authority: WO
Inventors: Kenneth Rubin
Original assignee: Kenneth Rubin
Priority date: 1987-06-08
Filing date: 1988-06-07
Publication date: 1988-12-15
Also published as: AU1989188A

Abstract

A clock has a digital read-out (50) for indicating the hour for the entire hour without apparent change and an analog hand (22) for indicating the minute. The minute-indicating hand is rotatable about a given axis, and the hour-indicating read-out (50) is substantially spaced from that axis and disposed on the minute-indicating hand for rotation therewith.

Description

CLOCK WITH DIGITAL/ANALOG FEATURES The present application is a continuation-in- part of U.S. Patent Application Serial No. 059,628, filed June 8, 1987, itself a continuation-in-part of U.S. Patent Application Serial No. 900,286, filed August 25, 1986, now U.S. Patent No. 4,692,032.

The present invention delates to apparatus for telling time, such as clocks, and more particularly to novel apparatus of that type having both digital and analog aspects.

Commonly owned U.S. Patent Application Serial No. 900,286, filed August 25, 1986, the disclosure of which is expressly incorporated herein by reference, discloses a clock having a digital hour-indicating means and an analog minute-indicating means. In addition to presenting an original and aesthetic appearance, the clock facilitated learning to tell time because the hour indicating means indicated the hour digitally for the entire hour so that the learner avoided the confusion of an hour hand situated between two hour markers. Nonetheless, the embodiment illustrated in that application was not entirely satisfactory. Because the illustrated embodiment required a raceway composed of twelve communicating spirals, the dimensions of the resultant clock were quite large, and hence so was the cost of materials. Further, at 12:00 o'clock the hour-indicating means and the minute-indicating means were at diametrically opposed ends of the clock so that it was difficult to gather all the information necessary to tell time with a single swift glance at the clock, especially where the clock was of large dimensions. Indeed, it is believed that the closer the juxtaposition of the hour-indicating means and the minute-indicating means, the easier it is for beginners, especially children, to learn to tell time.

It will be appreciated that the clocks to which the present application and the above-identified application relate require utilization of both the digital hour-indicating means and the analog minute-indicating means in order to tell time and that there is but one hour-indicating means and one minute-indicating means per clock.

Accordingly, it is an object of the present invention to provide a clock having digital-analog aspects which is sufficiently compact for economical manufacture.

Another object is to provide such a clock which facilitates learning to tell time. A further object is to provide such a clock wherein in one embodiment the minute-indicating means and the hour-indicating means are closely adjacent. Yet another object is to provide such a clock wherein the hour-indicating means is disposed on, is part of, or gives the appearance of either being disposed on or part of the minute hand. It is also an object to provide such a clock wherein in one embodiment the mechanism is of rugged and reliable construction.

It has now been found that the above and related objects of the present invention are obtained in a clock having only a single hour-indicating means and only a single minute-indicating means, for use together to indicate time. The clock comprises digital means for indicating the hour for the entire hour without apparent change, and analog means for indicating the minute.

Preferably the minute-indicating means is rotatable about a given axis, and the hour-indicating means is substantially spaced from the axis and disposed on said minute-indicating means for rotation therewith. More particularly, the minute-indicating means comprises a minute hand having a distal end pointing to the minute, and the hour-indicating means is disposed closely adjacent the distal end. The hour-indicating means and the minute-indicating means are each rotatable about a substantially common axis. The hour-indicating means displays the hour by a digit or digits in a substantially vertical orientation, regardless of the angular orientation of the minute-indicating means. The digit or digits are pivotally secured to a common vertically oriented rotatable disk, whereby gravity maintains them substantially vertically oriented, regardless of the angular orientation of the disk.

In a preferred embodiment, the clock further includes an hour-keeping mechanism for driving the hour-indicating means, a minute-keeping mechanism for driving the minute-indicating means, a motor for continuously driving the minute-keeping mechanism at a constant rate, and means for instantaneously incrementing the hour-keeping mechanism after each full revolution of the minute-keeping mechanism. Preferably, the incrementing means comprises a wolf's tooth gear, a detent, and means biasing the detent and gear to engage and thereby forcibly rotate the gear. The minute-keeping mechanism further comprises a cam adapted to space the detent from the gear against the biasing means except once per revolution of the minute-keeping mechanism. More specifically, the gear has twelve teeth, the detent is biased to bear against the teeth, and the biasing means urges the gear towards the detent. The cam is an internal cam configured and dimensioned to space the detent from the gear by forcing the gear away from the detent against the biasing means at the beginning of an hour, maintaining the gear in a position spaced from the detent until the end of a full revolution of the minute-keeping mechanism, and at the end of the hour momentarily permitting movement of the gear under the influence of the biasing means towards the detent, thereby enabling the gear and the detent to engage and thereby forcibly rotate the gear by one of the teeth.

In one embodiment, the incrementing means comprises means for intermittently connecting and disconnecting the hour-keeping mechanism and the minute-keeping mechanism so that the minute-keeping mechanism drives the hour-keeping mechanism through a full rotation therewith, then momentarily disconnects the mechanisms to permit substantially instantaneous relative rotation of the mechanisms, and finally reconnects the mechanisms for another full rotation of the minute-keeping mechanism. The wolf's tooth gear is secured to the hour-keeping mechanism for rotation therewith as a unit, whereby forcible rotation of the gear by the detent causes the hour-keeping mechanism to disconnect from the minute-keeping mechanism, rotate relative thereto for substantially one-twelfth of a revolution, and then reconnect thereto for another full rotation of the minute-keeping mechanism, the relative rotation of the mechanisms causing the hour-indicating means to increment to display of the next hour. The hour-keeping mechanism comprises a first rotatable disk secured to the gear for rotation therewith, and the minute-keeping mechanism comprises a second rotatable disk defining the cam. The disks have interengaging parts, one of the disks having a sole interengaging part and the other of the disks having twelve parts adapted to be successively engaged by the sole interengaging part, the interengagement of the parts being overcomable momentarily by the forcible rotation of the gear by the detent. In another embodiment, the gear is secured to the hour-keeping mechanism for rotation therewith as a unit, whereby forcible rotation of the gear by the detent causes the hour-keeping mechanism to rotate substantially one-twelfth of a revolution at the end of each full rotation of the minute-keeping mechanism, such rotation of the hour-keeping mechanism causing the hour-indicating means to display the next hour. The clock additionally includes means for biasing the hour-keeping mechanism against all rotation except that induced by forcible rotation of the gear.

In one aspect of the clock of the present invention, the digital means comprises first indicator means, a set of indicia representing hours, and means for associating the first indicator means successively with respective ones of the indicia fixedly for an hour each. The analog means comprises second indicator means,^' the position of the second indicator means representing minutes, and means for continuously varying the position of the second indicator means.

Preferably the first indicator means is associated with one of the one indicia in a fixed positional relationship throughout the hour represented, and the varying means continuously varies the angular orientation of the second indicator means, the position of the second indicator means indicating minutes being its angular orientation. The associating means associates the first indicator means and the associated indicium without relative movement between the first indicator means and the associated indicium for the hour. In the first embodiment the clock additionally includes means for continuously varying the position of the first indicator means throughout each hour, and means for associating the first indicator means and the associated indicium with the second indicator means without relative movement therebetween throughout the hour. in another aspect of the clock of the present invention, the digital means includes a driven component, the analog means includes a driven component, and the clock additionally includes means for driving the driven components of the analog means and the digital means at the same rate of angular rotation.

In the third and fourth embodiments the minute-indicating means and the hour-indicating means are adapted for rotation about a common axis, and the hour-indicating means is transported by the minute-indicating means. More particularly, a hand extends radially outwardly from the common axis, the hand being rotatable about the common axis with both the minute-indicating means and the hour-indicating means to provide said clock with the appearance of both the minute-indicating means and the hour-indicating means being disposed upon or a part of the hand.

Preferably, the portion of the minute-indicating means transporting the hour-indicating means is non-transparent, the hour-indicating means is transparent, and illuminating means is provided behind the hour-indicating means as back lighting theref«or.

The portion of the minute-indicating means intermediate said common axis and the hour-indicating means may be opaque.

In a preferred aspect of these embodiments, an electronic hour-keeping mechanism drives an electronic hour-indicating means and instantaneously increments the hour-indicating mechanism after each full hour, while an electric motor continuously drives the minute-indicating means at a constant rate. More particularly, the digital means comprises first indicator means for displaying a set of indicia representing the hours, the analog means comprises second indicator means, the position of the second indicator means representing minutes, and said clock additionally displaying means for continuously varying the positions of the first and second indicator means throughout each hour. The position of the first and second indicator means are the angular positions thereof relative to a common axis. The orientation of the first indicator means relative to the second indicator means is also continuously varied throughout each hour.

Preferably the clock includes an indicator having first and second states, the indicator in the first state indicating the imminent approach of the end of the hour and in the second state indicating otherwise. The indicator is preferably part of the digital means with its states determined by the digital means, independently of the analog means.

The above description, as well as further objects, features and advantages of the present invention, will be more fully understood by reference to the following detailed description of the presently preferred, albeit illustrative embodiments of the present invention when taken in conjunction with the accompanying drawing wherein: FIG. 1 is a front elevation view of a first embodiment of a clock according to the present invention; FIG. 2 is a side elevation view, partially in cross section, taken along the line 2-2 of FIG. 1;

FIG. 3 is a front elevation view taken along the line 3-3 of FIG. 2; FIG. 4 is a front elevation view, partially in cross section, taken along the line 4-4 of FIG. 2;

FIG. 5 is a fragmentary rear elevation view taken along the line 5-5 of FIG. 2;

FIG. 6 is a fragmentary front elevation view, partially in cross section, taken along the line 6-6 of FIG. 2 with the gear being shown in its lower position in solid line and in its upper position in phantom line;

FIG. 7 is a side elevation view, partially in corss section, of a second embodiment of a clock according to the present invention;

FIG. 8 is a fragmentary front elevation view, partially in cross section, taken along the line 8-8 of FIG. 7;

FIG. 9 is a front elevation view of the second embodiment;

FIG. 10 is a front elevation view of a third embodiment; of a clock according to the present invention;

FIG. 11 is a side elevation view, partially in cross-section, of the third embodiment;

FIG. 12 is a front elevation view of a fourth embodiment of a clock according to the present invention; and

FIG. 13 is a side elevation view, partially in cross-section of the fourth embodiment.

Referring now to the drawing, and in particular to FIGS. 1-6 thereof, therein illustrated is a clock generally designated by the reference numeral 10 and constituting a first embodiment of the present invention. The housing of the clock 10 comprises a back wall 12, a side wall 14 projecting forwardly from the back wall 12, and a partial front wall 16 extending inwardly from side wall 14. disposed on the face of the front wall 16 are a circumferentially spaced series of numbers and dots or other conventional symbols 17 representing the minutes of the hour.

Substantially disposed within the large open area 18 formed by the housing and supported by four rollers or bearings 19 for rotation relative to the housing is a hollow cylinder, generally designated by the reference numeral 20, which acts as part of the minute-keeping mechanism. The minute-keeping cylinder 20 includes a rear disk 21 rotatable therewith. Disposed at the front of the minute-keeping cylinder 20 for rotation therewith is an outwardly projecting minute indicator 22 (such as an arrowhead) which typically extends at least partially over the front wall 16 to point to a particular symbol 17 representing a minute. The minute-keeping disk 21 further defines a rearwardly projecting rim or internal gear 24 containing inwardly facing teeth 26. A stationary motor 28, which may be powered by a battery or an external power supply (neither shown), engages the teeth 26 of the rim 24 via an output worm screw 30, a series of reduction gears 32 and a pinion 33, such that the minute-keeping mechanism 20 is caused to undergo a full 360° rotation once per minute.

For reasons which will become apparent hereinafter, the minute-keeping disk 21 further defines a centrally disposed internal cam 34, and a single spring clip 36 is secured to a mount 37 projecting forwardly from the front surface of the disk 21. the minute-keeping cylinder 20 includes an opaque front wall 38 extending over the entire face of the disk 21, except where it defines a circular cutout 40 (which may be left either as a void or filled in with a transparent sheet) , preferably contiguous with minute indicator 22. The hour-keeping mechanism, generally designated by the reference numeral 50, comprises a disk 52 generally coaxial with and of substantially smaller diameter than the disk 21 of the minute-keeping mechanism 20. The disk 52 is disposed intermediate disk 21 and front wall 38. Forwardly projecting from the front surface of disk 52 are a series of circumferentially spaced pins 54 and secured to each pin 54 for pivotal movement thereabout is an hour paddle or panel 56 which is weighted at one end thereof or so configured and dimensioned that one end thereof will always point downwardly in response to gravity. The panels are consecutively numbered with one or two digits in counter-clockwise order from 1 to 12 with the respective number being disposed on the front surface of the panel 56. The number on the front surface of the panel 56 is oriented so that when the panel is in its normal orientation, with the weighted end down, the number appears vertical. The number is preferably of sufficient size to occupy most, but not all, of the window 40 on- the front wall 38 of the disk 21 of the minute-keeping mechanism 20. The back surface of the disk 52 of the hour-keeping mechanism 50 is provided with a series of twelve circumferentially spaced rearwardly projecting stop catches 58. Under normal circumstances the forwardly projecting spring clip 36 of the disk 21 will engage one of the rearwardly projecting stop catches 58 of the disk 52 as the disk 21 is rotated in a clockwise direction by the action of the motor 28. Once engagement is made between the spring clip 36 and the selected stop catch 58, the clockwise rotation of the disk 21 will carry with it the disk 52. Proper placement of the spring clip 36 and stop catches 58 will insure that a panel 56 is appropriately positioned for viewing through the window 40. The action of gravity on the freely pivotable panel 56 visible through the window 40 will insure that, as the hour progresses and the window 40 follows its clockwise route as the minute indicator 22 indexes to indicate the appropriate minute, the hour number indicated by that panel 56 through window 40 will remain vertically oriented in the proper position.

In order to increment the displayed hour after each full rotation of the minute-keeping mechanism 20, the hour-indicating disk 52 is connected to a special ratchet cjear 60 (to be described hereinafter) adjacent the rear wall 12 by a shaft 62, for rotation together as a unit. The shaft 62 passes through the internal cam 34 of disk 21 so that, as the disk 21 rotates clockwise from the on-the-hour position represented by the spring clip 36, the shaft 62 is forced closer to the center axis of the disk 21, maintained at a fixed distance for the remainder of the hour, and then permitted to move upwardly in response to the urging of expansion spring 64. Expansion spring 64 has an upper end secured to an elbow 66 of the housing projecting forwardly from rear wall 12 and a lower end secured to shaft 62 to exert an upward force thereon. Thus, under the biasing influence of spring 64, the shaft 62 at all times rides the uppermost point of the inner surface of the internal cam 34 as the cam rotates with the disk 21 which defines it.

It will be appreciated that the rear end of shaft 62 must be journaled in a vertically-extending slot 68 in back wall 12 in order to enable suitable vertical motion of the shaft 62 throughout the hour (see FIG. .5). Similarly, disk 52 must be of sufficiently smaller diameter than disk 21 to enable free vertical motion of the disk 52 throughout the hour without interference from the minute-keeping mechanism 20. Similarly, either the spring clip 36 or stop catch 58 must be of sufficient length to insure that the engagement therebetween is retained despite the slight vertical shift between these elements throughout the course of the hour. Finally, the numbers on the panels 56 must be sufficiently smaller than the height of window 40 so that each number remains visible throughout the hour despite the very slight shift in the vertical disposition of the number within the window 40 as a result of the vertical shift in shaft 62. It will be appreciated that the use of the worm 30 as the output shaft of motor 28 enables the motor 28 to drive the internal gear 24 even though the vertical disposition of the internal gear 24 (and the pinion 33 and reducing gears 32) will undergo vertical movement with shaft 62 relative to the fixed motor 28.

The ratchet gear 60 is a wolf's tooth gear having twelve teeth 69, one for each hour to be displayed on the clock (see FIG. 6). It is a property of a wolf's tooth gear that, as it is brought into engagement with a radially directed resilient detent, the detent will force a rotation of the gear by one tooth, here equivalent to 30°. Depending from the elbow 66 in vertical alignment with the gear 60 is a resilient detent 70. The detent 70 is configured and dimensioned to engage the gear 60 as the shaft 62 reaches the shaft-releasing portion of the internal cam, thereby allowing rapid upward motion of the shaft 62, in response to the biasing action of spring 64. This results in a movement of the gear 60 and shaft 62 from the lower position indicated in phantomline in FIG. 6 to the raised position indicated in solid line, with the resultant sideways motion of detent 70 from the unstressed position indicated in phantom line to the stressed position indicated in solid line. The resulting engagement of the detent 70 and gear 60 forcibly moves the gear 60 in a clockwise direction by one tooth with sufficient force and abruptness to break the engagement between the spring clip 36 of disk 21 and the stop catch 58 of disk 52 with which it was engaged. It will be appreciated that the disk 21 is not free to follow the sharp motion of the disk 52 as the orderly rotation of the disk 21 is under the control of motor 28. As the abrupt motion of the disk 21 under the influence of detent 70 terminates, the spring clip 36 of the disk 21 is in an appropriate position to engage the stop catch 58 associated with the next hour (beyond that with which it was engaged prior to engagement of the detent 70 and gear 60). To illustrate operation of the hour-incrementing mechanism, as the minute-keeping disk 21 rotates during the course of an hour from the on-the-hour orientation, the shaft 62, secured at one end to the hour-keeping mechanism disk 52 and at the other end to the wolf's tooth gear 60, is first depressed by the gradually curved incline of internal cam 34 and then maintained by the constant radius portion of cam 34 in a depressed position until the end of the hour. During this time the two disks 21 and 52 are maintained together as a unit for rotation together by means of the engagement of spring clip 36 and a stop catch 58. At the end of the hour, the sharp outward slope of internal cam 34 releases the shaft 62 for upward motion under the bias of spring 64, thereby causing detent 70 to sharply impinge upon gear 60 and to cause a forcible relative rotation of disk 52 in the clockwise direction. After this abrupt engagement of the detent 70 and gear 60, the next stop catch 58 is in condition for engagement with spring clip 36, and the continued rotation of disk 21 causes cam 34 to again initiate depression of shaft 62, thus ending the engagement of gear 60 and detent 70. As the minute indicator 22 rotates around the face of the clock, so do the window 40 of front wall 38 and the appropriate hour indicator 56 visible therethrough, so that it appears that the hour indicator is disposed on or is part of the minute indicator. If desired, the front wall 38 may be designed so that it appears as if there is a hand extending from the center of the clock all the way to the minute indicator, that hand including the minute indicator 22 and hour indicator 56. To summarize, this embodiment of the invention provides a clock of strikingly unusual and aesthetic design with digital/analog features, the clock being sufficiently compact for economical manufacture. The hour-indicating means (including the window and paddle displayed therein) is disposed adjacent a distal end of the minute indicator, thereby facilitating reading of the hour and minute together as necessary to tell time. Referring now to FIGS. 7-9, therein illustrated is a second embodiment of the present invention comprising a clock generally designated by reference numeral 100. Whereas in the first embodiment 10 the hour-indicating means is apparently disposed on and rotated with the minute-indicating means, in the second embodiment 100 the hour-indicating means appears through a stationary window. While the hour-indicating means and minute-indicating means are not in as close juxtaposition as in the first embodiment 10, the second emϋlbodiment 100 is a very compact design affording substantially greater stability against vibration and shock than the first embodiment. Elements of the second embodiment performing functions generally corresponding to those performed by elements of the first embodiment will be designated by the corresponding three digit numeral in the 100 series.

The housing is comprised of the rear wall 112, a side wall 114 and a front wall 116, the latter being opaque except for an hour revealing circular window 140 (which may be an aperture or a transparent material as shown) and a transparent peripheral margin 200 on which are disposed a circumferentially spaced series of numbers or numbers and dots or other conventional symbols 117 representing the minutes of the hour.

Within the volume 118 defined by the housing, there is disposed a minute keeping mechanism, generally designated by the reference numeral 120, comprising a vertically oriented disk 121 defining an internal cam 134. A minute indicator in the form of a bar 122 is disposed on the front surface of the disk 121 so as to be visible through peripheral margin 200 of the front wall 116, and an internal gear 124 projects rearwardly from the back surface of the disk 121. A motor 128 secured to the housing drives internal gear 124, and hence the disk 121, through output worm screw 130, reducing gears 132, and pinion 133 which meshes with the internal gear 124. The housing further defines a guide channel 202 having radially inwardly extending walls disposed immediately in front of and to the rear of the edge of disk 121. The hour-keeping mechanism, generally designated by the reference numeral 150, comprises a vertically oriented disk 152 disposed intermediate the front wall 116 of the housing and the minute-keeping disk 121. Fixedly disposed on the front face of the hour-keeping disk 152 are a series of a circumferentially spaced numbers 204 from 1 to 12 representing the hours, the numbers 204 being oriented so that, as disk 152 rotates to bring them into alignment with the window 140, they are vertically oriented. The numbers 204 are slightly lesser in vertical extent than the window 140 so that the numbers remain clearly visible despite minor variations in the vertical position of the disk 152.

As in the first embodiment, indexing of the hour-keeping disk 152 at the end of an hour is effected when the internal cam 134 of the hour-keeping disk 121 allows a sharp upward movement of the horizontal shaft 162 connected at its forward end to the hour-keeping disk 152 and adjacent its rear end to a wolf's tooth gear 160, both for rotation therewith. As the shaft

162 is drawn sharply upward under the biasing influence of spring 164 depending from housing member elbow 166, the downwardly directed resilient detent 170 functionally rotates the wolf's tooth gear 160 by one tooth 169, thereby causing a corresponding indexing of the hour-keeping disk 152 to cause the next successive hour 204 to appear in window 140. Whereas the hour-keeping disk 152 rotated throughout the hour with the minute-keeping disk 21 in the first embodiment, in the second embodiment the hour-keeping disk 152 maintains a constant angular orientation throughout the hour until it is time for the incrementing the hour.

To this end, horizontal shaft 162 is secured at its forward end to disk 152 for rotation therewith as a unit and is journaled at its rear end in a short rectangular member 208 disposed within the rectangular slot 168 of the rear wall 112 of the housing. The short rectangular number 208 is slidable up or down the rear wall slot 168 as necessary to accommodate the varying vertical position of shaft 162, as it varies throughout the hour, but the width of the short rectangular member 208 substantially fills the width of the slot 168 to preclude rotation of the short rectangular member 208 relative to the slot 168. Immediately forwardly of the small rectangular member 208 is a large rectangular member 210 secured thereto, thereby to also preclude rotation of the large rectangular member 210. Disposed forwardly of the large rectangular member 210 is a stabilizing wheel 212 having 12 circumferentially spaced grooves 214 about its periphery, the stabilizing wheel 212 being secured to the shaft 162 for rotation therewith as a unit. A resilient pawl 216 extends towards stabilizing wheel 212 from a point 218 on the front face of the large rectangular member 210. The curved tip of pawl 216 enters one of the grooves 214 at the beginning of a hour to preclude accidental rotation of the shaft 162 during the course of the hour until, at the end of the hour, the shaft 162 is forcibly rotated. The forcibly rotation of shaft 162 results from a mechanism similar to that causing the forcible rotation of the shaft 62 in the first embodiment 10 — when the shaft 162 is freed by internal cam 134 for upward motion under the bias of spring 164, the detent 170 depending from elbow 166 engages the wolf's tooth gear 160, thereby causing the wolf's tooth gear 160 to rotate by one tooth 169, thus rotating the shaft 162 and hour disk 152 by 30°. It will be appreciated that the appearance of the second embodiment is basically similar to that of the first embodiment for the viewer, except that the hour indicator appears stationary rather than rotating with the minute indicator. Operation of the second embodiment is also substantially similar to operation of the first embodiment. The minute indicator disk 121 is rotated at the rate of one cycle per hour by motor 128. During this rotation the hour-indicating disk 152 is maintained in its angular orientation by the action of pawl 216 on the stabilizing wheel 212, the stabilizing wheel 212 being linked to the hour-indicating disk 152 by means of shaft 162. At the end of the hour the internal cam 134 of the minute-keeping disk 121 releases the shaft 162 for abrupt upward motion under the bias of spring 164, and the engagement of resilient detent 170 and wolf's tooth gear 160 overcomes the stabilizing action of the pawl 216 and causes rotation of the hour-keeping disk 152 until the next hour is exhibited in the window 140 and the tip of pawl 216 settles in the next groove 214 of stabilizing wheel 212. It will be appreciated by those skilled in the mechanical arts that while a wolf's tooth gear in the form illustrated is preferred, other gears functionally equivalent to the wolf's tooth gear may be employed to provide the abrupt and forcible indexing of the hour-keeping disk at the end of an hour. Also, if desired, the wolf's tooth gear may be reversed (that is, turned in the opposite direction) if the order of the hour numbers on the hour-keeping mechanism is also reversed, the result being substantially the same for the viewer. In the first embodiment the forwardly projecting spring clip 36 of the disk 21 and the rearwardly projecting stop catches 58 of the disk 52 may be substituted by a series of forwardly projecting stop catches 58 on the disk 21 and a rearwardly projecting spring clip on the disk 52, provided that the spring clip and stop catches offer the requisite intermittent connection and disconnection of the disks 21, 52 as described hereinabove.

To summarize, the second embodiment of the present invention provides a clock of unusual and aesthetic design having digital/analog aspects, the clock being sufficiently compact for economical manufacture and facilitating learning to tell time, the second embodiment is of especially rugged and reliable construction.

Referring now to FIGS. 10-11, therein illustrated is a third embodiment of the present invention comprising a clock generally designated by the reference numeral 300. Whereas in the first embodiment 10 the hour-indicating means is apparently disposed on and rotated with the minute-indicating means, in the third embodiment 300 the hour-indicating means is in fact disposed on and rotated with the minute-indicating means. The mechanical aspects of the working mechanism of the third embodiment are greatly simplified relative to the first and second embodiments to provide an even greater maintenance-free performance as well as reduced manufacturing costs. Elements of the third embodiment performing functions generally corresponding to those performed by elements of the first embodiment will be designated by corresponding three-digit numerals in the 300 series.

The housing of the clock 300 comprises a back wall 312, a side wall 314 projecting forwardly from the back wall 312, and a front wall 316 extending inwardly from side wall 314. Disposed on the face of the front wall 316 are a circumferentially spaced series of numbers and dots of other conventional symbols 317 representing the minutes of the hour. A stationary motor 328, which may be powered by a battery or an external power supply (neither shown), is disposed within the housing and secured to the back wall 312 at the center thereof. The motor 328 drives a radially extending minute hand or indicator 322 at the rate of one cycle per hour through a vertical plane. The minute hand 322 preferably extends radially outwardly from the central horizontal axis of the clock and terminates in tip 400, shaped like a point or arrow, adjacent to or intersecting the minute representations 317. The central portion of the front wall 316 is preferably opaque or translucent so that the motor 328 is not visible therethrough, thereby focusing attention on the minute hand 322 itself and the minute representations 317. An hour-keeping and -indicating means 402 of cylindrical design has its side wall journaled into an aperture in the minute hand 322 with ball bearings 404 being provided to facilitate movement of the hour cylinder 402 relative to the minute hand 322. The hour cylinder 402 is disposed intermediate the axis of rotation of the minute hand 322 and the tip 400 thereof, preferably closely adjacent the tip 400 and substantially spaced from the axis of rotation. The bottom portion of the hour-keeping and -indicating means 402 is enlarged (as shown) or weighted so that, under the influence of gravity, the bottom portion will always be the lowest portion, irrespective of the position of the minute hand 322, with the minute-keeping and -indicating means 402 rotating relative to minute hand 322 under the influence of gravity. Thus, in its mechanical self-righting aspect the hour-indicating means 402 is similar to the hour paddle or panel 56 of the first embodiment.

In its electronic aspects, the hour-keeping and -indicating mechanism 402 comprises a device having an LED or LCD hour display and associated electronics. The device has a display in which the digit or digits of the hour are displayed for one hour and then incremented to indicate the next hour. Such devices, which may be standard digital time displays with the minute display portion disabled, are available from Uce, Inc. of S. Norwalk, Conn.

If desired, the display device may further include an AM/PM display so as to avoid any confusion as to which 12-hour segment of the day is involved. Furthermore, it is preferred that the display device include a controller and an indicator 406 which is turned "on" by the controller a few minutes before the hour changes (i.e., imminent to the end of the hour) and is turned "off by the controller as the hour changes. The indicator 406 may simply be a bar underneath the digit or digits representing the hour, although other indicators may be used. The purpose of the indicator is to avoid the confusion which might otherwise arise as to the correct hour when the minute hand is pointing at or very close to due north — that is, at the "zero" or "sixtieth" minute. As there is always the possibility that the minute hand is slightly ahead of or behind where it should be, confusion might arise if the hour indicator was "12" and the viewer was uncertain as to whether the time was 12:59 or 12:01. With the optional indicator feature, if the indicator is turned on (indicated in solid line in FIG. 12), the time is before the change of the hour and therefore

12:59; and if the indicator is turned off (indicated in phantom line in FIG. 10), then the time is just past the change of the hour and therefore 12:01. This feature is not required in a conventional two-handed clock as the position of the hour hand is utilized in conjunction with the position of the minute hand to clearly distinguish between 12:59 and 12:01. For ease and economy of manufacture as well as trouble-free maintenance, both the motor 218 and hour-keeping and -indicating means 402 are battery operated — i.e., each has its own battery. While they may also be powered by a common power supply (e.g., an external power supply), expensive trouble-prone commutators are required in this instance between parts moving relative to one another, such as the minute hand 322 and motor 328, on the one hand, and the hour-keeping and -indicating means 402 and the minute hand 322, on the other hand.

The facility with which the clock 300 of the third embodiment may be utilized to teach children or the mentally handicapped how to tell time is self evident in FIG. 10. Even a child can be easily taught that the time is 12:04 or 4 minutes after 12. The closer proximity of the hour and minute readings further facilitates the telling of time by those with a narrowed field of vision. Referring now to FIGS. 12-13, therein illustrated is a fourth embodiment of the present invention comprising a clock generally designated by the reference numeral 500. Whereas in the third embodiment 300 the hour-indicating means is disposed on and rotated with the minute hand and appears to be disposed on and rotated with the minute hand, in the fourth embodiment 500 the hour-indicating means is disposed on and rotated with the minute-indicating means, but appears to be free floating. Elements of the fourth embodiment performing functions generally corresponding to those performed by elements of the third embodiment will be designated by the corresponding three digit numerals in the 500-series. The housing of the clock 400 comprises a back wall 512, a side wall 514 projecting forwardly from the back wall 512, and a partial front wall 516 extending inwardly from the side wall 514. Disposed on the face of the front wall 516 are a circumferentially spaced series of numbers and dots or other conventional symbols 517 representing the minutes of the hour. Along the central horizontal axis of the device is a stationary motor 528, secured to the back wall 512.

The motor 528 is adapted to drive a coaxial minute disk 522, substantially disposed slightly rearwardly of the front wall 516, through a vertical plane at the rate of one revolution per hour. The minute disk 522 is opaque and carries a minute indicator 600 disposed forwardly of the housing front wall 516 and terminating adjacent to or intersecting the minute representations 517 on the housing front wall 516. The minute disk 522 and its extension 600 comprise a minute hand. A cylindrical hour-keeping and -indicating means 602 is journaled into the minute disk 522 by ball bearings 604, as in the third embodiment 300. The hour cylinder 602 is disposed intermediate the axis of rotation of the minute 522 and the minute indicator 600, preferably closely adjacent the minute indicator 600 and substantially spaced from the axis of rotation. The bottom portion of the hour-keeping and -indicating means 602 is enlarged (as shown) or weighted so that, under the influence of gravity, the bottom portion will always be the lowest portion, irrespective of the angular orientation of the minute disk 522, with the hour-keeping and -indicating means 402 rotating relative to minute hand 322 under the influence of gravity. Thus, in its self-righting mechanical aspect the hour-indicating means 602 is similar to the hour-indicating means 402 of the third embodiment and the hour panel or paddle 56 of the first embodiment.

In the fourth embodiment, however, the non-transparent elements of the hour cylinder 602 — other than the digits themselves — are disposed outside of the periphery of the display, typically in an extension 610 behind the opaque minute disk 522, as shown in FIG. 13. Thus the portion of the minute disk 522 which is occupied by the hour-keeping and -indicating means 602 is, except for the hour-indicating digit or digits and the "on" indicator bar 606, substantially transparent or translucent. If desired, the hour-keeping and -indicating means 602 may also have an opaque or contrastingly-colored circumferential border or margin, as illustrated.

Also disposed in the housing is an illumination source 612 for back lighting the transparent portion of the hour-keeping and -indicating means 602. While the illumination source 612 may simply be an incandescent light, an annular neon bulb disposed about the motor 528 and secured to the housing back wall 512 is preferred. The light source 612 provides back lighting for the digital display representing the hour so as to create an overall visual impression of the hour digit or digits (either alone or with a circumferential border) floating along a path adjacent the circumference of the clock face and pointing to the appropriate minute representations 517. If desired, the minute indicator 600 may be formed of fiber optic material so that it is illuminated by the illumination source 612, thereby further facilitating reading of the minutes, even in the dark. While the back-lighting effect is most impressive in a dark environment, such as at night, it is -clearly present even in a well lighted environment, such as an illuminated room.

The hour-keeping and -indicating means 602, the motor 528 and the illumination source 612 may each be independently powered by electrical storage means (i.e., batteries) or all three may be powered by a common electrical storage means or an external power supply. While only low level illumination is required from the illumination source 612, the power demands of the illumination source 612 and motor 528 far exceed the power demand of the hour-keeping and -indicating means 602; accordingly, the former may be easily and conveniently connected to an external power supply (without any need for commutators or the like), while the latter is provided with electrical storage means which may be adequate for powering the same on a continuous basis for one-three years.

Operation of the third and fourth embodiments is self-evident. The motor 328, 528 drives the minute indicator 400, 600 at one revolution per hour. The minute hand 322 or disk 522, connecting the motor 328, 528 and minute indicator 400, 600, carries a self-contained hour-keeping and -indicating means 402, 602. As the latter displays for the hour in question a digit or digits representing the hour, the hour-keeping and -indicating means 402, 602 freely rotates relative to the minute hand 422 or disk 522 under the influence of gravity to maintain the hour digit or digits in a vertical orientation adjacent the appropriate minute representation.

To summarize, the third and fourth embodiments of the present invention provide a clock having digital/analog aspects of novel aesthetic design, the clock including self-contained electronic means for keeping and indicating the hour, thereby eliminating much of the mechanical aspects of the clocks of the first and second embodiments to provide a clock which is less expensive to construct and less likely to require repair.

Now that the preferred embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be limited only by the appended claims, and not by the foregoing specification.

Claims

WHAT IS CLAIMED IS:

1. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time comprising:

(A) digital means for indicating the hour for the entire hour without apparent change, and

(B) analog means for indicating the minute; said minute-indicating means being rotatable about a given axis, and said hour-indicating means being substantially spaced from said axis and disposed on said minute-indicating means for rotation therewith.

2. The clock of Claim 1 wherein said hour-indicating means and said minute-indicating means are each rotatable about a substantially common axis.

3. The clock of Claim 2 wherein said minute-indicating means comprises a minute hand having a distal end pointing to the minute, and said hour-indicating means is disposed intermediate said common axis and said distal end.

4. The clock of Claim 1 wherein said hour-indicating means displays the hour by a digit or digits in a substantially vertical orientation, regardless of the angular orientation of said minute-indicating means.

5. The clock of Claim 3 wherein said hour-indicating means comprises an aperture.

6. The clock of Claim 2 wherein said minute-indicating means comprises a minute hand having a distal end pointing to the minute, said hour-indicating means is at all times closely adjacent said distal end.

7. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising:

(B) analog means for indicating the minute; said hour-indicating means displaying the hour by a digit or digits in a substantially vertical orientation, regardless of the angular orientation of said minute-indicating means, said digit or digits being pivotally secured to a member disposed for rotation in a vertical plane, whereby gravity maintains said digit or digits substantially vertically oriented regardless of the angular orientation of said member.

8. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising:

(A) digital means for indicating the hour for the entire hour without apparent change, (B) analog means for indicating the minute,

(C) an hour-keeping mechanism for driving said hour-indicating means, (D) a minute-keeping mechanism for driving said minute-indicating means,

(E) means for continuously driving said minute-keeping mechanism at a constant rate, and (F) means for instantaneously incrementing said hour-keeping mechanism after each full revolution of said minute-keeping mechanism.

9. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising:

(A) digital means for indicating the hour for the entire hour without apparent change,

(B) analog means for indicating the minute,

(C) an hour-keeping mechanism for driving said hour-indicating means,

(D) a minute-mechanism for driving said minute-indicating means,

(E) means for continuously driving said minute-keeping mechanism at a constant rate, and (F) means for instantaneously incrementing said hour-keeping mechanism after each full revolution of said minute-keeping mechanism, said incrementing means comprising a wolf's tooth gear, a detent, and means biasing said detent and gear to engage and thereby forcibly rotate said gear; • said minute-keeping mechanism further comprising a cam adapted to space said detent from said gear against said biasing means except once per revolution of said minute-keeping mechanism.

10. The clock of Claim 9 wherein said gear has twelve teeth, said detent is biased to bear against said teeth, said biasing means urges said gear towards said detent, and said cam is an internal cam configured and dimensioned to space said detent from said gear by forcing said gear away from said detent against said biasing means at the beginning of an hour, maintaining said gear in a position spaced from said detent until the end of a full revolution of said minute-keeping mechanism, and at the end of the hour momentarily permitting movement of said gear under the influence of said biasing means towards said detent, thereby enabling said gear and said detent to engage and thereby forcibly rotate said gear by one of said teeth.

11. The clock of Claim 9 wherein said incrementing means comprises means for intermittently connecting and disconnecting said hour-keeping mechanism and said minute-keeping mechanism so that said minute-keeping mechanism drives said hour-keeping mechanism through a full rotation therewith, then momentarily disconnects said mechanisms to permit substantially instantaneous relative rotation of said mechanisms, and finally reconnects said mechanisms for another full rotation of said minute-keeping mechanism.

12. The clock of Claim 11 wherein said gear is secured to said hour-keeping mechanism for rotation therewith as a unit, whereby forcible rotation of said gear by said detent causes said hour-keeping mechanism to disconnect from said minute-keeping mechanism,

~ rotate relative thereto for substantially one-twelfth of a revolution, and then reconnect thereto for another full rotation of said minute-keeping mechanism, said relative rotation of said mechanisms causing said hour-indicating means to display the next hour.

10 13. The clock of Claim 12 wherein said hour-keeping mechanism comprises a first rotatable disk secured to said gear for rotation therewith, and said minute-keeping mechanism comprises a second rotatable disk defining said cam, said disks having interengaging ⁵ parts, one of said disks having a sole interengaging part and the other of said disks having twelve parts adapted to be successively engaged by said sole interengaging part, the interengagement of said parts being overcomable momentarily by the forcible rotation 0 of said gear by said detent.

14. The clock of Claim 9 wherein said gear is secured to said hour-keeping mechanism for rotation therewith as a unit, whereby forcible rotation of said gear by said detent causes said hour-keeping mechanism 5 to rotate substantially one-twelfth of a revolution at the end of each full rotation of said minute-keeping mechanism, said relative rotation of said hour-keeping mechanism causing said hour-indicating means to display the next hour.

15. The clock of Claim 14 additionally including means for biasing said hour-keeping mechanism against all rotation except that induced by forcible rotation of said gear.

16. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising: (A) digital means for indicating the hour for the entire hour without apparent change, and

(B) analog means for indicating the minute, said digital means comprising first indicator means, a set of indicia representing hours, means for associating said first indicator means successively with respective ones of said indicia fixedly for an hour each, and means for continuously varying the position of said first indicator means throughout each hour, and said analog means comprising second indicator means, the position of said second indicator means representing minutes, and means for continuously varying the position of the second indicator means.

17. The clock of Claim 16 wherein said first indicator means is associated with one of said one indicia in a fixed positional relationship throughout the hour represented, and said varying means continuously varies the angular orientation of said second indicator means, the position of said second indicator means indicating minutes being its angular orientation.

18. The clock of Claim 16 wherein said associating means associates said first indicator means and said associated indicium without relative movement between said first indicator means and said associated indicium for the hour.

19. The clock of Claim 17 including means for continuously varying the angular orientation of said first indicator means throughout the hour.

20. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, βomprising:

(A) digital means for indicating the hour for the entire hour without apparent change, including a driven component,

(B) analog means for indicating the minute, said analog means including a driven component, and

(C) means for driving said driven components of said analog means and said digital means at the same rate of angular rotation.

21. A clock having only a single hour-indicating means and only a single minute-indicating means for use together to indicate time, comprising: (A) digital means for indicating the hour for the entire hour without apparent change,

(B) analog means for indicating the minute, said minute-indicating means and said hour-indicating means being adapted for rotation about a common axis and being so disposed relative to one another as to create the appearance that said hour-indicating means is disposed upon or a part of said minute-indicating means.

22. The clock of Claim 21 wherein a hand extends radially outwardly from said common axis, said hand being rotatable about said common axis with both said minute-indicating means and said hour-indicating means to provide said clock with the appearance of both said minute-indicating means and said hour-indicating means being disposed upon or a part of said hand.

23. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising: (A) electronic digital means for indicating the hour for the full hour without apparent change;

(B) analog means for indicating the minute;

(C) an electronic hour-keeping mechanism for driving said hour indicating means and for instantaneously incrementing said hour-indicating mechanism after each full hour; and

(D) an electric motor for continuously driving said minute-indicating means at a constant rate.

24. A clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising: (A) digital means for indicating the hour for the full hour without apparent change; and

(B) analog means for indicating the minute; said digital means comprising first indicator means for displaying a set of indicia representing the hours, and means for continuously varying the position of said first indicator means throughout each hour, and said analog means comprising second indicator means, the position of said second indicator means representing minutes, and means for continuously varying the position of said second indicator means throughout each hour.

25. The clock of Claim 24 therein said position of said first and second indicator means are the angular positions thereof relative to a common axis.

26. The clock of Claim 24 wherein the orientation of said first indicator means relative to said second indicator means is also continuously varied throughout each hour.

27. The clock of Claim 24 therein the orientation of said first indicator means relative to said second indicator means is also continuously varied throughout each hour.

28. a clock having an hour-indicating means and a minute-indicating means for use together to indicate time, comprising:

(A) digital means for indicating the hour for the entire hour without apparent change; and

(B) analog means for indicating the minute; said hour-indicating means displaying the hour by a digit or digits in a substantially vertical orientation, regardless of the angular orientation of said minute-indicating means, said digit or digits being rotatable relative to and secured to a member disposed for rotation in a vertical plane, whereby gravity maintains said digit or digits substantially vertically oriented regardless of the angular orientation of said member.

29. A clock having only a single hour-indicating means and only a single minute-indicating means for use together to indicate time, comprising: (A) digital means for indicating the hour for the entire hour without apparent change;

(B) analog means for indicating the minute; said minute-indicating means and said hour-indicating means being adapted for rotation about a common axis, and said hour-indicating means being transported by said minute-indicating means.

30. The clock of Claim 29 wherein a hand extends radially outwardly from said common axis with both said minute-indicating means and said hour-indicating means to provide said clock with the appearance of both said minute-indicating means and said hour-indicating means being disposed upon or a part of said hand.

31. The clock of Claim 30 wherein the portion of said minute-indicating means transporting said hour-indicating means is non-transparent, said hour-indicating means is transparent, and illuminating means is provided behind said hour-indicating means as back lighting therefor.

32. The clock of Claim 31 wherein the portion of said minute-indicating means intermediate said common axis and said hour-indicating means is opaque.

33. A clock having only a single hour-indicating means and only a single minute-indicating means for use together to indicate time, comprising: (A) digital means for indicating the hour for the entire hour without apparent change;

(B) analog means for indicating the minute; and

(C) an indicator having first and second states, said indicator in the first state indicating the imminent approach of the end of an hour and in its second state indicating otherwise.

34. The clock of Claim 33 wherein said indicator is a part of said digital means.

35. The clock of Claim 34 wherein the state of said indicator is determined by said digital means.