Note: Descriptions are shown in the official language in which they were submitted.
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WORLD TIME DEVICE
FIELD OF THE INV~NTION
A device for determining the time at any geographical
location in the world rela-tive to a pre-selected location. The
device may be combined with a twenty-four hour clock mechanism
for automated operation.
BACKGROUND
Many devices and calcula-tion 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 familiari-ty with,
the subject of 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
ci-ties, or even countries, on such a combination of maps.
Moreover, the Margolis paten-t does not provide a visual coding
means whereby land areas falling within different time zones
may be readily distinguished. The Margolis reference further
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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.
SUMMARY OF THE INVENTION
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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, twenty~four evenly spaced first time zone
positions on the frame and together defining a first circle
which is outwardly concentric with the map and twenty-four
evenly spaced second time zone positions around the perimeter
of the map and together defining a second circle between and
concentric with the first circle and -the map. The map is a
south pole projection of the world and rotates in a clockwise
direction relative to the frame such that rotation occurs about
the center point of the map corresponding -to the south pole.
Each of the first and second time zone positions on the frame
corresponds to a distinct hour of a consecutive twenty-four-
hour time period. Land areas of the map and their associated
second time zone positions are visually coded so as to
correspond to distinct time zones. The map may be rotated in a
clockwise direction to align the second time zone position
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associated with a pre-selected land area with the corresponding
first time zone position to identify from the device, by
associating first and second time zone positions and
corresponding land areas by means of the visual coding, the
distinct hour of the twenty-four hours which corresponds to a
selected land area.
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
being fixed to the map so that -the map is caused to rotate by
and with the hour hand. 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.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 illustrates a world time clock device
embodying the inven-tion.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
The invention is described in detail in -the following
with reference to Figure 1. Reference numerals referred to
hereinafter refer to the reference numerals appearing in
Figure 1 to identify eleménts of the device illustrated
thereby. The embodiment of the invention of Figure 1 is
selected for purposes of illustration only; it is to be
understood by the reader that other embodiments might instead
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be selec-ted if desired, for example, an embodiment whieh is
manually operable.
Referring to Figure 1, a world time eloek device 10
is shown having a frame 15, a rotatable map 50 positioned
thereover, twen-ty-four first time zone positions 20, 35 evenly
spaced around said frame 15 and beyond the outer boundary of
the map 50 so as to define a circle thereon, and twenty-four
evenly spaced second time zone positions 30, 40, 45, 160 on and
around the perimeter of the map 50 and together defining a
second circle between and concentric with the circle defined by
the first time zone positions and the map 50.
The map 50 is a south pole projection of -the world
and rotates in a cloekwise direetion abou-t the center point 150
of the map whieh eorresponds to the south pole. A eonventional
twenty-four-hour eloek meehanism (not shown) is installed below
the map 50 and within the frame 15, the eloek meehanism
comprising an hour hand 60, a minute hand 70 and a second hand
80. The hour hand 60 is fixed to the rotatable map 50 so that
the automated rotation of the hour hand 60 (via the
conventional battery-operated cloek mechanism) eauses the map
50 to rotate wi-th -the hour hand 60 as the hour hand 60 rotates.
A full eireular rotation of the hour hand 60, and therefore the
map 50, oeeurs onee every twenty-four-hour period. (A north
pole projeetion map is not suitable as the device eould not
then use a eonventional clock meehanism which operates in a
eloekwise direction; rather a eounter-clockwise rotation of the
map would be r~quired. A further disadvantage assoeiated with
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a north pole projection map would be a high concentration of
land around the center of the map.)
The twenty-four first time zone positions (e.g. 20)
are marked to identify the hours of a single twenty-four-hour
time period from 12 a.m. to 11 p.m. For clarity and improved
readability, these hourly markings also include the marking
"NOON" in association with the time zone position marked 12
p.m. and "MIDNIGHT" in association with the 12 a.m. time zone
position. Each time zone position (20) corresponds to a
distinct hour of a twenty-four-hour time period and, therefore,
the hour hand 60 passes by a first time zone position (20)
every hour. The minute hand 70 rota-tes once every hour (the
same as for conventional twelve hour clocks) and, therefore,
passes by a first time zone position (20) every two and a half
minutes. Similar to -the operation of the minute hand 70, the
second hand 80 passes by a first time zone position (20) every
two and a half seconds. Accordingly, the time of the day
indicated by the clock hands 60, 70, 80 shown in Figure 1 is
12:51:41 p.m. This is the time for all land areas corres-
ponding to first time zone position 30.
Because the map 50 is a single south pole projection
map of the world, portraying all land areas of the world in a
single plane relative to the south pole, the longitudinal lines
(e.g. 170, 175) do not identify or distinguish different time
zones of the land areas shown on the map. Rather, the
differen-t time zones corresponding to land areas of the map 50
are visually distinguished by means of colour coding. For
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example, with reference to Figure 1, -the colour coding selected
for -the land area 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 longi-tudinal lines 170, 175. The second time
zone position 30 is also colour-coded with the colour red such
that all land areas which are colour-coded with the colour red
correspond to the red colour-coded second time zone position
30. In turn, the second time zone position 30 is aligned
with, and corresponds to, the first time zone position 35
representing, in Figure 1, 12 p.m. In any given quadrant of
the map 50, the colour selected for the visual coding of land
areas within the same time zone is not duplicated, to avoid
confusion in identifying land areas within distinct time zones,
but may be duplicated in the opposite quadrant without risk of
confusion. Thus, in the embodiment of Figure 1, it was elected
to also use the colour red for the second time zone position
160 and its associated land areas 165 falling within the time
zone 12 a.m.
To set the device 10 for use in the particular
geographical area in which the user is located, the hour hand
60 is positioned so as to align with the first time zone
position which corresponds to the closest hour of tha-t
geographical area and the minu-te and second hands are aligned
with the first time zone positions corresponding to the minute
and second of tha-t area (bearing in mind that each first time
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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 Ottawa, Canada and the hour hand 60 is approaching
the first time zone position marked "1 p.m.". The device
identifies the time in Ottawa, Canada as being 12:51:41 p.m.
(approaching 1 p.m.). The same time applies to all other land
areas having -the same colour coding as the second time zone
position 45 (which is aligned with the 1 p.m. first time zone
marking) for example, New York City 130.
To determine the time in any other selected
geographical land area, outside of the time zone comprising the
land areas which are colour-coded to correspond -to the 1 p.m.
first time zone position marking shown in Figure 1, one
identifies the colour associated with that land area, the
second time zone position nearest that area which corresponds
to that colour and the corresponding first time zone position
located above that second time zone position. For example,
with reference to Figure 1, it may be seen that when the time
in Ottawa, Canada is 12:51:41 p.m., the time in Mexico is one
hour earlier, that is, 11:51:41 a.m. Simultaneously, the time
in all other land areas of the map, relative to -the pre-
selected land area (being Ottawa in the foregoing example) may
be determined according to the foregoing procedure.
To account for land areas which are situated in half
hour time zones, a different vlsual coding means is used to
identify such areas. In the embodiment of Figure 1, vertical
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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. In Figure 1, therefore, Newfoundland, Canada
is colour-coded to be the same colour as Greenland and is also
coded by vertical lines 100 to identify that the time in
Newfoundland is one-half hour prior to that in Greenland.
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
Alaska corresponds to the 8 a.m. first time zone position
marking and that New Zealand corresponds to the 6 a.m. first
time zone position marking. 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, as well as the first time zone
position markings 1 a.m. to 6 a.m., all of these positions
pertain -to the day following that of Ottawa, Canada.
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
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s-tated previously, the clock mechanism need not be included if,
say, a manually operable pocket device, according to the
nventlon, were to be instead desired. In the case of a
hand-operated device, the user may prefer to rotate the frame
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in counter-clockwise direction relative to the map to set the
time zone positions for a pre-selected land area, rather than
to rotate the map, the two manners of operation being
equivalent.
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