GB2375404A

GB2375404A - Multi zone clock display with spiral hour hand

Info

Publication number: GB2375404A
Application number: GB0105323A
Authority: GB
Inventors: Robert Darwen
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-03
Filing date: 2001-03-03
Publication date: 2002-11-13
Also published as: GB0105323D0

Abstract

A clock which enables the time in different time zones to be read simultaneously from the dial. The clock has a dial which is divided radially into a maximum of 12 segments of 30 degrees each, each segment (1, fig 1) representing a particular time zone. Each segment is further divided into 12 concentric bands (2, fig 2) representing the hours in each time zone over a 12 hour period. The clock has a single hand (4, fig 4) in the form of an Archimedes' spiral with its origin at the centre of the dial and terminating near the circumference of the dial and having 12 reference points (5, fig 4) along the length of the hand. As the spiral hand revolves around the dial at a rate of one revolution per 12 hour period, the time in one or more time zones can be read by noting the position of each reference mark on the hand with respect to the radial and concentric markings on the dial.

Description

MULTI ZONE CLOCK This invention relates to a multi time zone clock.

Dial clocks are devices for measuring the passage of time whereby the circumference of a disk is divided into uniform sections and marked with the numeric sequence of a conventional time period; i. e. 12 divisions of 30-degrees and the number sequence 1 to 12 for the 12-hour time period or 60 divisions of 6-degrees with the number sequence 1-60 for either the 60-minute time period or the 60-second time period.

From the centre of this disk or'dial'rotates a radial arm or'hand'that passes in uniform speed across the marked divisions along the circumference of the dial thus indicating the passage of time. Each full rotation of an arm is equivalent to one full sequence of the time period marked; i. e. the'hour hand'marking the 12-hour time period makes one full revolution around the dial every twelve hours, the'minute hand'marking the 60-minute time period makes one full revolution around the dial every sixty minutes while the'second hand'marking out the 60-second time period makes one full revolution around the dial every sixty seconds. Commonly all three of these time periods are marked on the same disk- Dial clocks of this kind can show only one time zone, however. To know the time in another part of the world it is necessary to refer to another clock that is adjusted to the local time zone in question or to make an arithmetic calculation where the difference between two time zones is known.

An object of this invention is to allow for the simultaneous'reading-off of multiple time zones from only one dial clock, with the movement of only one indicator and without the need for any calculation.

Accordingly, the present invention provides a dial that is marked with up to twelve 30 degree sectors, each representing a different time zone. These sectors are divided into twelve radial'bands'and marked 1-12 to indicate the conventional twelve-hour time period mentioned above. Each sector's 1-12 marking are adjusted against the other sectors'markings. The moving indicator of the clock is an archimedian spiral of one revolution that has twelve indicating marks along its length. This spiral arm (or 'hand') makes a single clockwise revolution every twelve hours and its markings traverse in turn each of the sectors'radial bands, indicating the passage of the hour and the actual hour in the time zone represented by each sector.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which :- Figure 1 shows a disk with three 30 degree sectors marked on it.

Figure 2 shows a section of each of the three sectors divided into twelve radial bands and one of the sectors marked 1-12.

Figure 3 shows all three sectors marked 1-12 and the name of a city adjacent to each of the three marked sectors.

Figure 4 shows the archimedian spiral arm and twelve markings along its length.

Figure 5 shows the archimedian spiral arm in place on the clock face.

Figure 6 shows the archimedian spiral arm on the clock 4 hours and 15 minutes later.

Referring to the drawings Fig 1 shows three 30-degree sectors at equal distance from each other; 1 indicates one of the three sectors. This example is of a clock that shows the time in three time zones simultaneously. The remaining 270 degrees on the disk could be used for up to a further nine 30-degree sectors which would show the time in up to nine further time zones.

Fig 2,2 indicates one of the radial bands in one of the 30-degree sectors. This radial band is achieved by dividing both radii of a section of the 30-degree sector into twelve equal parts and drawing arcs between the twelve divisions. The arc length of each of these radial bands represents the time period of one hour. Fig 2,3 indicates one of the hour markings, in this case the hour 4, either am or pm.

Fig 3 shows all three sectors/time zones marked with the numeric sequence 1-12 indicating the conventional twelve hour time period in three different time zones.

The order of the 1-12 numeric sequence in the sectors is adjusted relative to one another. The time zone that each sector represents is indicated by the name of a city in that time zone placed adjacent to the sector. The arrows adjacent to two of the sectors (12 & 13) indicate whether that time zone is before or after the time that is indicated in the London time zone.

Fig 4,4 shows a right-handed archimedian spiral arm of one revolution. This revolution begins at the point of the innermost radial band of the sectors and ends at the extent of the outermost radial bands. The innermost point of the archimedian spiral (6) extends directly and is attached to a spindle at the centre of the disk, which is itself connected to the motive power source. The spiral arm makes one full revolution every twelve hours. The archimedian spiral arm has, along its length (4) (from its outer to inner extent), twelve markings (5) that serve as indicators of the passage of time across a particular hour and of the actual hour that obtains in the sectors'indicated time zone. The distance between the markings on the spiral arm decreases in direct correspondence to the decreasing length of the radial bands across which each spiral arm mark traverses in its revolution around the dial; i. e. starting from the outer extent of the spiral the distance between the first and second markings

on it is equivalent to the circumferential length of the outer-most radial band and the distance between the second and third marking is equal to the circumferential length of the second-most outer radial band and so on until the eleventh and twelfth markings on the spiral where the distance between them is equivalent to the circumferential length of the inner-most radial band of the sector/s.

Fig 5 shows the archimedian spiral arm in place on a clock face designed to show the time in three different time zones. The arm is caught in the process of making one full revolution every twelve hours. It can be seen from 7,8, 9, respectively, that the markings on the spiral arm indicate that it is half past the hour'l'in the London time zone, half past the hour'11'in the Sydney time zone and half past the hour'8'in the New York time zone.

Fig 6 shows the clock four hours and fifteen minutes later showing, from 10, 11, 12, respectively, that it is 5. 45 in London, 3.45 in Sydney and 12.45 in New York.

It can be seen from Fig 5 and Fig 6 that as each spiral arm marking traverses and reaches the edge of its corresponding radial band then the next mark on the spiral arm begins its passage across the next radial band, and so on until all twelve markers have passed across all twelve radial bands in a sector and a full sequence of the time period has been completed. The spiral arm will have made one full revolution and the sequence can begin again.

It should be noted in addition that while the numeric sequence in the example runs from low numbers to high'inwards', i. e. from the edge of the dial to the centre and that the archimedian spiral is right-handed, the reverse can order can be used but the spiral would be left-handed (or right-handed but turn counter-clockwise).

It should also be noted that while the example given shows sectors marking the 12hour time period it is also possible to mark the 60-minute and/or 60-second time period within a sector: the divisions and numbering of the sector and the markings and turning speed of the indicating spiral arm would be scaled accordingly as per the scaling on a conventional clock. In short a conventional clock that marked hours, minutes and seconds could be represented in three 30-degree sectors divided into twelve, sixty and sixty numbered divisions respectively, with three spiral arms with twelve, sixty and sixty markings each making one full revolution every twelve hours, sixty minutes and sixty seconds, respectively.

It should further be noted that the positioning of the 30-degree sectors in the dial and in relation to one another is only dependant upon the ordering of the numeric sequence within the sectors radial bands; i. e. the three sectors/time zones in the example fig 5 could be adjacent to one another (forming a block sector of 90-degrees) with no lose of accuracy just so long as the ordering of the numeric sequence in the

individual sectors is adjusted to correspond to the passage of the relevant spiral arms' mark.

It should finally be noted that any number of 30-degree sectors from one to twelve can be used depending on however many time zones (from only one or to the maximum twelve) are required.

Claims

CLAIMS 1 A clock comprising an hour hand in the form of a spiral and where the twelvehour time period is marked radially from the centre of a dial. The time is read off by the passage of the spiral arm along the radially marked time period. Other identified world time zones are marked radially on the dial and when the number order in these other time zones is adjusted relative to one another and to the position of the spiralarm the time is be read off simultaneously in the different time-zones by the movement of the spiral-arm.