The present invention relates to a device for determining the time in any geographical location in the world relative to the time of any selected location. The device may be combined with a twenty-four hour clock mechanism for automated operation. Many devices and calculation means for determining the time in different time zones of the world have been used in the past. However, all such prior means have required some form of calculation, or skilled operation, on the part of the user or a high degree of knowledge of, and familiarity with the subject or world geography.

United States Patent No. 594,410 to Margolis describes one such device comprising two overlapping maps which together rotate by means of the operation of a twenty- four-hour clock mechanism, one map being of the southern hemisphere and the other of the northern hemisphere. However, a high degree of visual confusion is caused by the use of such overlapping maps and it is difficult to identify the position of selected cities, or even countries, on such a combination of maps. Moreover, the Margolis patent does not provide visual coding means whereby land areas falling within different time zones may be readily distinguished. The Margolis reference further does not readily lend itself to the marking of city and country names on the maps themselves because of the fact of there being two overlapping maps and, therefore, several areas having too many associated names to mark on the limited area provided.

The invention claimed herein provides a device for determining the time of day anywhere in the world, and the device does not have associated with it the above-identified disadvantages of the prior art. The device may be manually operable or may instead be automated in the form of a clock. Essentially, the device comprises a frame, a rotatable map positioned thereover, a first time zone attached to the frame and defined by an annular band which is outwardly concentric with the map and evenly divided into twenty-four segments and a second time zone defined by an circumferential ring located

around the perimeter of the map and evenly divided into twenty-four segments. The map is a south pole projection of the world and it may be rotated manually or by a clock mechanism about the center point corresponding to the south pole. Preferably, for the manual embodiment, a hour hand is also provided. For both manual and automated embodiments, the hour hand rotates clockwise together with the map. Each of the first time zone segments on the frame corresponds to a distinct hour of a consecutive twenty-four-hour time period. The respective hour is printed in the middle of the sector. Preferably, when a 12 numbers scale is used, a.m. and p.m. abbreviations are recommended for distinguishing the day hours from the night hours. Each of the second time zone segments on the map periphery are visually distinct. Preferably they are color coded. These segments are centered on the longitude lines, 15° apart (corresponding to one hour) .

The geographical time areas are comprised of lands of longitude character having the same local hour. For practical reasons they are typically set off from surrounding lands by conventions (e.g. territorial, statal or economical) . Land areas of the map are also visually coded so as to corespondent to a proximal second time zone sector. Thus, each second time zone has an associated geographical time area. The map should be rotated to align the second time zone sector with the first time zone sector for setting the local time (known) of the selected geographical area. Thus, by associating second and first time zone sectors, the time of all geographical areas can be determined by means of the visual coding. In a preferred embodiment of the invention, the operation of the device is automated by means of a twenty- four-hour clock mechanism, the hour hand of the clock mechanism advancing with the map (i.e. the map rotates together with the hour hand) . For re/setting the zone, (i.e. when re/installing the device in a selected geographical area) the hour hand should be positioned into the middle of the second time zone

sector which is colour coded as the selected geographical area (i.e. the area of re/location) . A stop mechanism enables the hour hand to be rotated counterclockwise for re/positioning it. The map will not rotate counterclockwise with the hour hand.

For setting the time, the hour, minute and second hands should be positioned at will as for any known clock, in accordance with the local time. The map will rotate with the hour hand in the clockwise direction. Another preferred embodiment refers to a manual device. For this case, only an hour hand is provided. For re/setting the zone, the hour hand is rotated counterclockwise as described above. Then the map with the hour hand are rotated clockwise towards the position indicating the local time.

For both embodiments described above, after re/setting the zone and the time, the local time of any geographical area may be continuously read against the first time zone annular band, using the visual codification. Furthermore, the possibility of creating a computer data base containing the south pole projection of the world map in the form of a clock face, the first and the second time zones (using an adequate visual codification) , hour, minute and second hands is also envisaged. The clock image may be retrieved from the computer memory and displayed under supervision of a program capable also of re/setting the zone and the time, as described above.

The manual embodiment can be used as an example in schools for didactic purposes (i.e. for explaining to the students changes of the dates and hours around the world) .

The automatic embodiment may be used by air and sea lines, in armed forces and business houses.

Preferably, the device, whether manually operable or in the form of a clock, includes additional visual coding means associated with land areas of the map which are in half- hour time zones.

Figure 1 illustrates a world time clock device embodying the invention;

Figure 2 is a perspective view illustrating the stop mechanism for the hand hour-map re/setting (of the zone) ; Figure 3 is a lateral view illustrating the stop mechanism for the hand hour-map re/setting.

The invention is described in detail in the following with reference to Figures 1 to 3. Each device item will be further referred by same reference numeral in all drawings. The embodiment of the invention of Figures 1 to 3 are selected for purposes of illustration only; it is to be understood by the reader that other embodiments might instead be selected if desired, for example, an embodiment which is manually operable. Referring to Figure 1, a world time clock device 10 is shown having a frame 15, a rotatable .map 50 positioned thereover and a first time zone annular band 85. The annular band 85 is evenly divided into twenty-four first time zone sectors 20, 45, is fixed to the frame 15 and arranged partly beyond the outer boundary of the map 50. A second time zone circumferential ring 40, defined on and around the perimeter of the map 50 is divided into twenty-four evenly spaced second time zone sectors 30, 35.

The map 50 is a south pole projection of the world and, in one preferred embodiment, rotates in a clockwise direction about the center point 150 which corresponds to the south pole. A conventional twenty-four-hour clock mechanism 25 is installed below the map 50 and within the frame 15. The clock mechanism comprises an hour hand 60, a minute hand 70 and a second hand 80. The hour hand 60 is fixed on a hour shaft 55 together with the rotatable map 50 so that they are rotated together by the conventional (e.g. battery-operated) twenty-four hour clock mechanism 25. A full circular rotation of the hour hand 60, and therefore the map 50, occurs once every twenty-four-hour period. (A north pole projection map is not suitable as the device could not then use a conventional clock mechanism which operates in a clockwise

direction; rather a counter- clockwise rotation of the map would be required. A further disadvantage associated with a north pole projection map would be a high concentration of land around the center of the map.) The twenty-four first time zone sectors 20 are marked to identify each hour of a twenty-four-hour time period from 12 a.m. to 11 p.m. For clarity and improved readability, these hourly markings may also include the marking "NOON" in association with the first time zone sector marked 12 p.m. and "MIDNIGHT" in association with 12 a.m. first time zone sector. The hour hand 60 traverses a first time zone sector 20 in one hour. The minute hand 70 rotates once every hour (the same as for conventional twelve hour clocks) and, therefore, traverse each first time zone sector 20 in two and a half minutes. Similar to the operation of the minute hand 70, the second hand 80 traverses each first time zone sector in two and a half seconds. Accordingly, the time of the day indicated by the clock hands 60, 70, 80 shown in Figure 1 for all land areas corresponding to second time zone sector 30 is approximately 4:26:58.5 p.m. This is the time e.g. in Vancouver, Seattle and Los Angeles.

All land areas of the world are portrayed on the map 50 in a single plane relative to the south pole. The time zones, corresponding to geographical time areas of the map 50 are visually distinguished by means of colour coding. For example, with reference to Figure 1, the colour coding selected for the geographical time area 180, comprising the Canadian province of Manitoba, the United States state of Minnesota downwards through to Louisiana, Mexico and Central America is red (shown in Figure 1 by dark shading) and, as can be seen from the map 50, this area crosses over the longitudinal lines 175 and 185. The second time zone sector 35 is also colour-coded with the colour red such that all geographical time areas 180, which are colour-coded with the colour red correspond to the red colour-coded second time zone sector 35. The center of the second time zone sector 35 indicate approximate 6:26:58.5 p.m., being positioned between

the first time zone sector 45 indicating, in Figure 1, 6 p.m. and a first time sector indicating 7 p.m. For any given geographical area, the time can be read in a similar way. In any quadrant of the map 50, the colour selected for the visual coding of land areas within a geographical time area is not duplicated, to avoid confusion in identifying land areas. The colours may be duplicated in the opposite quadrants without risk of confusion. Thus, in the embodiment of Figure 1, it was elected to also use the colour red for a second time zone and its associated land areas diametrically opposed to second time zone 35 and time areas 180. The time for that geographical time area is approximate 6:26:58.5 a.m.

To install the device 10 for use in the particular geographical area in which the user is located, two types of settings are required.

A first step consists of setting of the zone. To this end, the hour hand should be rotated counterclockwise while the map is held immobile, towards a position where the hour hand lays in the middle of a second time zone of interest (i.e. having same colour with the geographical area of the new location) . The hour hand should be aligned with that respective longitudinal line. This is obtained by the use of a stop mechanism as illustrated in Figures 2 and 3. An hour shaft 55 has such length as to receive over it the disc with the map 50 and the hour hand 60. On the back face of the map, a disc 65 is attached. Its diameter is smaller than the map diameter. The assembly consisting of the map 50 and the disc 65 is mounted in such a way that it can slide over the hour shaft. Disc 65 has a flexible tab 75. The disc is rotated with the map 50 and with the hour hand 60 by the hour shaft 55 of the clock mechanism 25 in a clockwise direction. At the base of the frame, along the circumference of a central bottom concavity 200, a circular row of ratchet teeth 95 is arranged. When the map moves with the hour shaft 55 in the clockwise direction, the tab 75 slides over the ratchet teeth of the circular row of ratchet teeth 95. When re/setting of the zone is requested, the hour hand 60 should be gently rotated

counterclockwise toward the new desired position in the middle of the respective second time zone sector aligned with the central longitudinal line of the new zone. The tab 75 would oppose the rotation of the map 50, because it will be locked between two ratchet teeth.

The second step consists of setting the time and this takes place after the first step has been accomplished. To this end, the use of a classic twenty-four hour clock mechanism will allow the hour and minute hand to be rotated clockwise and positioned to show the correct time. The hour hand 60, the minute hand 70 and the second hand 80 will be positioned so as to indicate on the first time zone the hour, the minutes and seconds of that area (bearing in mind that each first time zone position corresponds only to two and a half minutes or seconds, respectively) .

Referring to Figure 1, the device 10 is set for use in the preselected geographical land area comprising Los Angeles, U.S.A., and the hour hand 60 is moving towards the first time zone position marked "5 p.m.". The device identifies the time in Los Angeles, U.S.A., as being 4:26:58.5 p.m. The same time applies to all other land areas having the same colour coding as the second time zone sector 30 for example Seattle, U.S.A., or Vancouver, Canada. To determine the time in any other selected geographical land area at this particular moment, one identifies the colour associated with that land area, the second time zone sector nearest that area which corresponds to that colour and reads the time on the first time zone annular band corresponding to that a second time zone sector. For example, with reference to Figure 1, it may be seen that when the time in Alberta, Canada indicated by the second time zone sector 100 is 5:26:58.5 p.m., the time in Los Angeles, U.S.A., is one hour earlier, that is 4:26:58.5 p.m. Simultaneously, the time in all other land areas of the map, may be determined according to the foregoing procedure. To account for land areas which are situated in half hour time zones, a different or a supplementary visual coding means is used to identify such areas. In the embodiment of

Figure 1, vertical lines are used to indicate an area for which the time is one-half hour prior to the neighbouring land areas having the same colour code. Therefore, India is colour-coded to be the same colour as Pakistan and is also coded by vertical lines to identify that the time in India is one-half hour prior to that in Pakistan. It can be assumed that embodiments where the base colour of half time zones is selected so that their time will be read by adding one half hour to the time of the neighbouring land areas having the same colour are also conceivable.

The International Date Line 90 marks the date applicable to the geographical areas of the map 50. To illustrate this with reference to Figure 1, it is shown that one of Alaska•s second time zone sector indicates on the first time zone 3:26:58.5 p.m. and that Eastern State of Australia's second time zone sector indicates on the first time zone 10:26:58.5 a.m. If the date is 1 January in Ottawa, Canada, the date in Alaska is also 1 January, but 2 January in New Zealand. Since the a.m. hour applicable to New Zealand falls on the opposite side of the International Date Line relative to Alaska, the time of this geographical area pertains to the day following that of Ottawa, Canada.

Furthermore, on the front face of the frame 15, three circular concentric concavities may be included; i.e. a bottom, a middle and an upper concavity. As shown in Figures 2 and 3, in the bottom concavity 200, the circular row of ratchet teeth 95 is fixed along the circumference, as described above for the stop mechanism. The middle concavity 210 includes the circular map 50 so that it may freely rotate (i.e. without touching the concavity walls) . The upper concavity 220 is created for fixing the first time zone annular band 85. The annular band 85 preferably will partially obturate the second time circumferential ring on the map 50, for creating a guide for the map into the frame 15. For the automated embodiments of the device, the clock mechanism is arranged under the face of the frame 15. The hour, minute and second shafts traverse the front face of the

frame for engaging the hour hand and the map, the minute hand and the second hand respectively. A cover may be provided as a back and front face of the frame for protecting the clock mechanism. While the foregoing specific description is directed to the embodiment shown in Figure 1, the invention is not limited to the described embodiment. Many variations of the specific features described above might be made while still falling within the scope of the invention. For example, as stated previously, the clock mechanism need not be included if, say, a manually operable pocket device, according to the invention, were to be instead desired. In the case of a hand- operated device, the user may prefer to rotate the frame in counter-clockwise direction relative to the map to set the time zone sectors for a pre-selected land area, rather than to rotate the map, the two manners of operation being equivalent.

Furthermore, the conventional incorporation of a particular geographical area in a time zone may vary, because of political or economical reasons, without altering the scope of the present invention as claimed in the following claims.