Perpetual calendar

Abstract: The present invention deals with a variety of advanced perpetual calendars, combined calendars, multiple calendars, etc., using; a) yearly calendars comprising a minimum of two parts one mobile with respect to the other with one representing the weekdays and another representing the months of the year made in rectangular shape, in circular shape, in tubular shape, etc., b) monthly calendars comprising a minimum of two parts, one mobile with respect to the other with one represent­ ing the weekdays and another representing the days of the month, c) weekly/daily calendars displaying the 7 days of the week with the sub-divisions of the days into hours, d) short moon calendars with accommodations for the variable months in it, e) combined calendars joining a Gregorian calendar together with a short moon calendar, f) multi calendars comprising a board support­ ing two belts, showing a yearly calendar, a monthly calendar, and a weekly/daily calendar, using numbered weekdays, bypassing the language barrier, displayed on mobile belts, rotated yearly and monthly to adjust the calendars, while the main supporting board shows the twelve months of the year on the yearly calendar and the days of the month on the monthly calendar, g) multi calendars using circular, yearly and monthly calendars provided with pulleys and belts or chains and weights resulting in a mechanised joint calendar accommodating as well, a weekly/daily calendar using, waterproof transparent covering to allow the surface to be marked with water soluble ink and wiped out without affecting the calendar board,with a variety or cursors to pin­ point the day and its date and with large displays of the day and its date using the One Letter Alphabet system, resulting in a variety of perpetual calendars, wall calendars, desk calendars, pocket calendars, practical to use and easy to produce.

Description: The present invention deals with a variety of advanced, and improved perpetual calendars, and combined calendars using basically two or more units with at least one unit mobile with respect to the others with large scale displays using common variable symbols of One Letter Alphabet (OLA) system. Comparison with the prior art revealed no substantial prior art in that field that could replace the present invention. Field of The Invention The present invention is an improvement to my previous invention CA-A-1,233,447 and deals with a variety of advanced and improved perpetual calendars using; a) calendars with three units, mobile with respect to each other, with one unit representing the weekdays, one unit representing January and February and one unit representing the remaining ten months of the year March to December, b) calendars with two units one representing the weekdays on a belt mounted on the second unit representing the twelve months of the year, c) calendars using weekdays represented on belts and other belt or belts representing the twelve months of the year, d) calendars made of concentric transparent tubes, one representing the weekdays and the other representing the twelve months of the year, e) circular calendars using one ring or disc to display the weekdays and another to display the twelve months of the year, f) short lunar calendars using a plurality of belts one to represent the weekdays and others to represent groups of the months of the year, g) combined calendars combining gregorian calendars with short, lunar calendars, biblical calendars, Chinese calendars, etc., h) monthly calendars comprising a minimum of two parts, one mobile with respect to the other with one part representing the weekdays on a mobile strip or continuous belt and another part representing the days of the month, usually on five parallel rows, etc., i) weekly/daily planning calendars with a roll of transparent paper spread over the marking of the said calendars and unrolling to another pin on the opposite side, j) dual and multiple calendars using a yearly calendar together with a monthly calendar and a weekly/daily planning calendar, k) multiple circular yearly/monthly calendars with pulleys, gears, sprockets, etc., connected with belts, chains or the like rotating altogether with manual or motorized operation, etc., with cursors to pinpoint the actual weekday and its date and with large scale display of the weekday and its date by means of coloured, luminous or physical displays using common variable symbols based on the One Letter Alphabet (OLA) system, that could be visually read at a distance and could be sensed by the blind by touching process. Prior Art The prior art uses mainly disposable calendars hinging basically around the seven days weekly unit and since the number of days in the months differs from one month to the other, and since said numbers are not divisible by seven, it makes it difficult but not impossible to produce re-usable calendars hinging on the seven days weekly unit. Several attempts were made in the past to produce permanent calendars but failed to come up with a satisfactory permanent calendar in relation to the mechanisms, positioning of the units, display of information, and the overall cost, to replace the present calendars, taking into account that the calendars in use allow the user to write notes and appointments next to the dates while using the calendars. On the other hand a calendar hinging around the monthly unit results with very small figures hard to distinguish on a distant wall calendar. At the same time, the species of the art disclosed in CA-A-1233447 had to be further detailed and clarified. EP-A-0242739 discloses (in Figure 19) a perpetual calendar having twelve separate rows representing the twelve months of the year. Each of the twelve rows has the exact number of days of the respective month printed or engraved on it. To set the calendar each year, all twelve rows have to be re-set into their correct relative positions. US-A-2400268 describes a calendar which is not perpetual and is operational for a predetermined number of years only. Such are the problems that the present invention tries to solve to create perpetual calendars, practical to use and easy to produce. Summary of the Invention The present invention deals with perpetual, single, multiple, solar, gregorian and lunar calendars, with yearly, monthly calendars combined with weekly/daily agendas, with numbered weekdays and months in rectangular, tubular or circular shapes, etc.; a) with yearly and monthly calendars comprising a minimum of two units, one mobile with respect to the other and with one representing the weekdays and the other representing the year or the month, displayed on flat strips, on continuous belts, on circular discs or rings, etc., with surface laminated or superimposed transparent disposable or erasable papers, films or the like, for writing notes, appointments, etc., over the appropriate dates, b) with weekly/daily planning calendars marked on the main board with superimposed transparent disposable or erasable paper unrolling from one roll and rolling into another on the opposite sides of the calendar, c) with multi-calendars using yearly, monthly and weekly/daily agendas made compact and mounted on the same board with cursors and a large display of the actual day and its date by means of a common variable symbol using the One Letter Alphabet (OLA) system, resulting in a multi calendar unit, displaying the year, the month, the week and at different scales with provisions for writing notes and planning the week ahead all on the same unit. The perpetual calendar provided by the present invention is defined in claim 1, to which reference should now be made. Preferred yet optional features of the invention are defined in dependent claims 2 to 16. Brief Description of the Drawings Fig. 1 - Shows a perpetual calendar made of three sections placed parallel to each other. Fig. 2 - Shows a rectangular multi-perpetual calendar; a yearly calendar, a monthly calendar, and a weekly/ daily agenda. Fig. 2a - Is the same as Fig. 2, with large displays of the weekday and its date using One Letter Alphabet (OLA) system. Fig. 3 - Shows a circular multi perpetual calendar; a yearly, a monthly and a weekly/daily agenda. Fig. 3a - Shows an enlarged scale of the circular yearly calendar shown on Fig. 3. Fig. 3b - Shows an enlarged scale of the circular monthly calendar shown on Fig. 3. Fig. 4 - Shows a perpetual pocket calendar made of two continuous belts. Fig. 5 - Shows a perpetual tubular calendar made of concentric transparent tubes. Preferred Embodiments A variety of improved and advanced perpetual calendars embodying the present invention are described hereinafter: Fig. 1 shows a three-parallel-piece calendar comprising: A strip 1, displaying a number of consecutive weekdays equal to the number of days in the longest month in the calendar system under consideration plus 12. For the gregorian calendar, the number of consecutive weekdays for rectangular calendars is generally thirty-one plus twelve which equals forty-three. Said consecutive weekdays occupy the same number of equal divisions. A strip 2, showing the month of January and the month of February placed in their constant relation with respect to the weekdays, along two parallel rows representing: the month of January with 1 to 31 consecutive numbers and the month of February with 1 to 29 consecutive numbers occupying the same number of equal divisions, having the same width of the weekday divisions shown in No. 1. Ten rows, 3 showing the remaining ten months of the year placed parallel to each other in the same constant position to each other with relation to the weekdays. The three sections of the calendar are separated at separation lines 4. At the same time the three sections of the calendar are generally provided with holes, holding points or the like 5. A tie 6 is passed through certain calculated holes to join the three sections in their desired position with relation to the weekdays and to each other. To reset the calendar: For years where the twelve months keep the same number of days as in the previous year, the tie 6 is detached from the weekdays section and moved left or right to be connected to different holes on the weekdays section, to have the first of January, under the first week and in line with the weekday on which it begins, and the remaining eleven months of the year would automatically fall in place with relation to the weekdays. For years where the number of days in one or more months is changed from the previous year, the same operation described in (A) has to be repeated after every variable month. For the gregorian calendar, such calendar has to be reset after the month of February, to have the first of March in line with the correct weekday on which it begins. The present calendar shown in Fig. 1, is made of three sections to allow the re-setting of the twelve months in one operation at the beginning of the year. For leap years and the following years, the tie 6 is detached from both strips 1 and 2, and re-attached through different holes on both sections to have January and March fall in the right alignment with regard to the weekdays and the remaining months of the year would automatically fall in place with relation to the weekdays. A cursor 9 is mounted on a rail over the weekdays and stretches to the end of the twelve months, to indicate the current weekday and its date. The current weekday is seen in between the strings of the said cursor and its date on the row representing the current month, underlined by an indicator mounted in between the strings of the said cursor. Every day the cursor 9 is slid by one day's division to show the new day and its date. Every month the months indicator is slid in between the cursor strings to underline the following month. The calendar is provided also with holding points 7, made in the form of holes, horseshoes, pins or the like, to be used as holding points for coloured cords or strings 8 (see Fig. 2a), spread in between the said holding points to display the actual date at the largest scale possible. The upper edge of the calendar is provided with hanging holes, holding points, etc., at the opposite far ends keeping the central part of the top edge free, for the operation of the cursor. Fig. 2 shows a perpetual calendar comprising two main sections: A strip 1a showing the same number of consecutive weekdays as in Fig. 1, occupying the same number of equal divisions. The strip is made in the form of a continuous belt, folded around, in the present case of the gregorian calendar, at the opposite edges of thirty-seven divisions of the same size as the weekdays divisions, through opposite slots 12. A section 3a parallel to the weekdays strip, marked with the twelve consecutive months of the year placed in parallel rows and in the usual constant position with relation to each other, based on consecutive non-leap years where all the months of the year keep the same number of days as in the previous year. To set the calendar: (A) For non-leap years, the weekdays strip is pulled to have the 1st of January come in the zone of the first or second week of the row and in line with the weekday on which it begins, and the remaining eleven months of the year would automatically fall in place with relation to the weekdays. (B) For leap years, where the number of days in the month of February is different from the previous year, the same resetting operation should be repeated at the end of February, to have the 1st of March in line with the weekday on which it begins, and the following months will automatically fall in place with regard to the weekdays. The calendar is provided with a cursor 9, and with holding points 7, for the display of the actual weekday and its date at the largest scale possible. At the same time, to display the actual month on a large scale, the calendar is provided with: (A) A second strip 11 of large scale weekdays having a minimum of thirteen consecutive weekdays. The large scale weekdays strip 11 is folded over at the opposite sides of seven divisions, equal to the weekdays divisions, passed through two opposite slots 12 and folded back behind the main plate to have its opposite ends joined with each other, to form a continuous belt. (B) A section 13 parallel to the weekdays strip and marked with thirty-one consecutive numbers, 1 to 31, occupying thirty-one divisions equal to the weekdays divisions, and placed in parallel rows; four rows of seven divisions each, and three additional divisions at the beginning of the fifth row. The divisions are arbitrarily marked as if the 1st of a month of thirthy-one days falls on a Sunday, i.e., that the 1st, the 8th,the 15th, the 22nd, and the 29th of the month are aligned, with the 1st day of the week, occupying each the 1st division of each of the five rows. If the following month begins on Wednesday, the belt representing the weekdays is pulled to have Wednesday come in line with the first of the thirty-one divisions and the remaining thirty days of the month would automatically fall in place with respect to the weekdays. To allow the user to write notes on the calendar without spoiling the face of the calendar a transparent sheet of paper 14 is hung over the divisions representing the month, by means of pins 15, or the like, to be used for writing notes, appointments or the like, etc., over any of the thirty-one divisions shown below through the transparent paper. Such paper could be replaced each month or that they could be of durable transparent, erasable papers, mylar® film or the like, that they could be wiped with water and reused month after month. Alternatively, the same mylar® film described above, or the like, is laminated over the surface of the whole calendar, resulting in one plate calendar with waterproof surface that could be marked with water soluble ink and wiped out with water to make room for a new writing every month. In another arrangement, the main calendar plate itself is made of synthetic water-resistant film on which it would be possible to write with a water-soluble ink and wipe it out with water without affecting the original printing of the calendar. Another, possibility is that the main calendar plate is printed on the back of a transparent film, of mylar® or the like, leaving the front face of the calendar free for writing with water-soluble ink that could be wiped out and repeated without affecting the printing of the calendar itself. In addition, the calendar assembly is provided with a perpetual agenda made of multi diary markings 16, with writing provisions (A) to (D) possible: (A) A chassis mounted at the opposite sides of the diary markings, to accomodate a roll of transparent paper 17 on one side, unrolling to another pin 18, on the opposite side with the transparent paper passing over the diary markings, to be used for daily planning, appointments, or the like, marked on the transparent paper, using the calendar marking underneath as a guideline for daily handwriting. Every week or day the pin 18 is rotated to pull away the written paper and bring the new paper over the diary marking. (B) The diary marking is made on a detached board that is slipped in between the pages of a multi-sheet transparent blank diaryl (not shown), joined with a binder fastened on the board of the main calendar, resulting in a perpetual agenda attached to the main calendar plate. (C) A set of accordion-folded transparent papers or films used as a diary that could fold and unfold again on the opposite sides in the same way as the word processor unfolds and folds the papers fed to it, to allow for easy revision of notes by unfolding the accordion papers at any time. (D) Transparent waterproof film laminated over the diary marking to allow writing with water soluble ink that could be wiped with water without affecting the surface of the calendar. The perpetual multi-calendar is presented in different shapes and sizes including: (A) A wall calendar, comprising; a yearly calendar, a monthly calendar and a weekly/daily agenda, together with a cursor to indicate the actual day and its date and holding points to display the weekday and its date at a large scale by means of coloured ties distributed in between the main holding points, along the lines of the letters or numbers to be displayed. (B) A briefcase calendar in the shape of a regular double folder, one part inside the other, joined at the lower edges, with the triple calendar generally shown at the interior face of the inner folder, leaving the outer folder to protect the weekdays belts and with the whole assembly used as well to hold papers and documents in between the folds of the two folders. (C) A perpetual calendar/agenda having the weekly/daily schedule presented at the inner face of a general type folder, of an average two folds of 9" by 12" (23 cm by 30 cm) or the like, with an additional outer fold at its left, representing generally the monthly perpetual calendar and an opposite outer fold at its right side, representing a perpetual yearly calendar or the like, with the whole assembly, folded, perforated with long slots and installed on a ring binder with blank transparent waterproof folders inserted on the binder inside the weekly/daily calendar, using the printing underneath as guides, printed only with the names of the seven days of the week, without their dates and with the serial numbers of the weeks of the year from 2 to 52. Every week a filled sheet is removed, inserted behind the calendar assembly and replaced in sequence with the following transparent blank folder. This allows the user to keep a record of the fifty-two weeks of the year and wipe them with water and re-use them for the following year. The names of the weekdays on the transparent blank folder, representing the first week of the year are handwritten yearly and placed in their proper place ending with the weekday preceding the first day shown on the transparent folder representing the second week of the year. (D) A pocket calendar comprising; a reduced, yearly, monthly calendar together with a weekly/daily agenda generally showing the yearly calendar on one fold, the monthly calendar on another fold plus Monday, Tuesday, Wednesday schedules on three reversed front folds with Thursday schedule at the back of Wednesday, Friday at the back of Tuesday, and Saturday, Sunday together at the back of Monday, or the like, folded altogether usually in accordion shape, resulting in a credit card size pocket calendar. (E) A desk calendar made of a reduced form of the type (B) or (C), comprising; the perpetual calendar plate with its upper and lower edges connected to two different drums, joined together through their central shafts by means of two opposite plates or the like, allowing the rollers to move in one direction or the other,unrolling with them, the calendar plate to show the upper or lower sections of the said calendar. The rollers would have larger rims at the opposite sides to prevent the calendar plate from touching the supporting board. (F) A desk calendar using the same calendar plate described in (E) rolled on a single spring-loaded drum, mounted on a solid writing board generally displaying at first sight the schedule of the current day. To check any other date or to write additional notes, the calendar plate is pulled out along the writing pad, checked and then released in an operation similar to pulling or releasing regular window blinds. The calendars shown in Fig. 2 are usually made durable using: (A) Double-coated light-coloured cardboard, plastic board or the like. (B) A front surface laminated with waterproof transparent film, mylar® film or the like, or covered with waterproof transparent reusable film, or with transparent disposable papers, etc., to allow the user to write notes anywhere over the calendar and wipe them out with water or, in the case of detachable papers, to store the notes away for further reference. (C) The strips containing the weekdays are generally made of non-stretchable films, synthetic paper, tyvec, polyart 2, or the like, to resist handling and pulling through the calendar life. At the same time, the opposite ends of the strips, are generally joined to each other at the back of the calendar plate by means of double-sticking tapes, snaps or the like, to form continuous belts which are also fastened to the calendar plate to prevent the lateral movement of the weekdays with respect to the dates of the months. (D) To facilitate the reading of the calendar by anybody regardless of their languages provided they know the numbers from 1 to 10: The weekdays are numbered from 1 to 7 beginning with Sunday as No. 1 and ending with Saturday as No. 7, in the same way as they are referred to in the Bible and in the old languages. The twelve months of the year are also numbered from 1 to 12 beginning with January as No. 1, and ending with December as No. 12. Fig. 3 shows a circular disc or ring 1c, having a minimum of thirty-five consecutive weekdays occupying thirty-five equal divisions on the periphery of the said disc filling the 360 degrees of the circle. A smaller circular disc or ring 3c has the twelve months of the year placed in their constant relation with respect to the weekdays, on twelve concentric rows, divided, each of which with a number of divisions equal to the number of days in the months it represents, with each division occupying the same number of degrees occupied by a weekday division. The discs 1c, 3c are pivoted around a central pin 19 and are fixed to each other by pressure from the central pin, or by means of an eccentric short joining pin 21, or the like passing through corresponding holes 20. The joining pin 21 has a protruding edge at its base and the holes 20 are cut to accommodate the edge so that, by inserting the pin and rotating it, the protruding edge prevents the pin from falling down. To reset the calendar each year: (A) For years where the number of days in the month is the same as in the previous year, the pin 21 is taken out and one of the discs is rotated to have the 1st of January come in line wit the weekday on which it begins. The remaining eleven months automatically fall in place with regard to the weekdays. (B) For years where the number of days in one month or more is different from the previous year and, in the gregorian calendar, for the leap years, the same operation described in (A) has to be repeated at the end of February, to have the 1st of March come in line with the weekday on which it begins and the remaining nine months would automatically fall in place. To show the monthly calendar at a large scale, the present calendar shows an additional similar circular monthly calendar comprising: (A) A disc or ring 11a having seven consecutive weekdays occupying seven equal divisions filling the 360 degrees of the circle, around the periphery of the said disc. (B) A smaller disc or ring 13a, having thirty-one numbers occupying thirty-one divisions, each of which occupies 360 degrees divided by seven, placed in five concentric rows; seven divisions on each of the outer four rings and three divisions at the beginning of the innermost ring, or the like. The numbers are arbitrarily aligned 1 to 7 on the first row, 8 to 14 on the second row, 15 to 21 on the third row, 22 to 28 on the 4th row, and 29 to 31 on the 5th row. This setting places the numbers 1, 8; 15, 22, 29, all in line with Sunday, for example. The discs 11a and 13a are provided with corresponding holes 20a and a pin 21a, used to fasten the discs to each other as already described for the discs lc and 3c. To set the monthly calendar the pin 21a is removed and one of the discs is rotated to have the first of the new month come in line with the weekday on which it begins. The remaining thirty-one days now automatically fall in place with respect to the weekdays, then the pin 21a is put back in place to fasten the two discs together for the month. To pinpoint the actual day and its date on each of the calendars, the central pins of the two calendars 19, 19a are joined with a cord made in the form of a belt to be used as a double triangular cursor 22. The two arms of the belt are separated and passed through a multi-hole tubular section 23, or the like, that separates them: (a) on the yearly calendar, by 360 degrees over thirty-five and (b) on the monthly calendar, by 360 degrees over seven. This allows to show one weekday sector on the yearly calendar and a corresponding larger sector on the monthly calendar. The cursor 22 is provided at its opposite sides with slotted plates 24, 24a or the like, sliding along the arms of the said cursor to indicate the current date. Every day the yearly calendar is rotated by 360 degrees over thirty five to show the following day in between the arms of the 22 cursor on the yearly calendar and its date underlined by an indicator 24 positioned under the row representing the current month. At the same time, the same double cursor 22 shows, on the faster rotating monthly calendar, the weekday in between the arms of the cursor and its date underlined by an indicator 24a. To provide space for short notes, appointments or the like, the large scale disc 13a showing the thirty-one days of the month is laminated with a waterproof film or provided with slots and indentations to hold circular transparent papers 14a, cut in a circular shape and placed over the disc, to be used for writing notes and appointments on the transparent paper, guided by the daily divisions shown under the transparent paper. The paper could be replaced once a month or it could be made of permanent laminated waterproof transparent paper, mylar® or the like that could be erased at the end of the month and made available for the following month. To make it easy to operate, the dual calendar is provided with a pulley 25 on the yearly calendar and a smaller pulley 25a on the monthly calendar which pulleys are operated by different means, like: (A) By joining the pulleys with a belt 26 to transfer the movement from one to the other and a crank 27 is mounted at the centre of one of the pulleys for the operation of the calendar as a whole. (B) By means of chains and sprockets. (C) By means of a chain or cable wrapped around the opposite pulleys with counter weights at their opposite ends hanging down from the said pulleys. The pulleys 25, 25a are proportioned so that one pulley turns 360 degrees over seven, while the other one turns 360 degrees over thirty-five, to have both calendars rotate by one weekday division each, with a simple turning of the crank. The pulleys 25, 25a are made idle for adjustment when needed. In addition, the calendar is provided with a weekly/daily planner as described for Fig. 2, and with holding means to display the current weekday at a large scale one weekday and its date using the One Letter Alphabet (OLA) system. Fig. 4 shows a strip 1a the same as described for Fig. 2. A section 3c is made in the same way as section 3a described for Fig. 2 with the difference that the section 3c is made in the form of a belt folded around a board, chassis or the like 28 and passed through slots 12a where it can be rotated to bring the current month to be closer to the weekdays strip for better identification of each day and its date. At the same time, this reduces the overall size of the calendar, which makes it well suitable for a pocket calendar. Fig 5 shows a perpetual calendar comprising a minimum of two concentric, tubular, transparent sections: (A) An outer tubular section 1c having forty-three consecutive weekdays occupying forty-three equal divisions. (B) An internal transparent tube 3c having the twelve consecutive months of the year placed in parallel rows in the same way described for Fig. 2 with a difference that on Fig. 5 the rows follow the curvature of the tubular section. The tubular sections are supported by a chassis 29 and are provided with a knob 30 to allow the rotation of one tube with respect to the other to keep the current month always close to the weekdays strip. At the same time, the tubular sections have a mechanism allowing them to move parallel to each other for the yearly adjustment of the calendar. The tubular calendar is provided with a cursor 31 in the form of a sleeve with a window, around the outer tubular section. The cursor 31 is slid once a day to show the new day and its date.

Claims: A perpetual calendar comprising first (1; 1a; 1c; 11a) and second (2, 3; 3a; 3c; 13a) parts which are movable relative to each other, the first part being divided into a plurality of divisions of equal width, the divisions containing identifications of consecutive days of the week, the second part being divided into a grid having a plurality of rows and a plurality of columns intersecting to form the cells of the grid, the cells of each row of the grid containing consecutive numbers corresponding to the days of predetermined periods of days and each predetermined period being represented by a respective row, a first row of the grid adjacent the first part being alignable with the first part so that the divisions of the first part correlate with the cells of the first row of the grid, the calendar being characterised in that the first part (1; 1a; 1c; 11a) is movable as unit relative to the second part (2, 3; 3a; 3c; 13a) whereby, when the divisions of the first part are correlated with the cells of the first row of the grid, the cells of the remaining rows of the grid occupy predetermined positions relative to the divisions of the first part. A perpetual calendar according to claim 1, modified in that the second part (2, 3) is divided into first (2) and second (3) portions which are movable relative to each other, the first portion (2) having thereon the days of the year up to the end of February and the second portion (3) having thereon the days of the remainder of the year, the relative movement between the first and second portions allowing compensation to be made for the additional day in February in a leap year. A perpetual calendar according to claim 2, having means (5, 6; 20, 21; 20a, 21a) for releasable linking together of the first and second portions of the second part for movement as a unit relative to the first part. A perpetual yearly calendar according to claim 1, wherein the number of days on the first part (1; 1a; 1c; 11a) is equal to the number of days of the longest month of a predetermined calendar system plus twelve, the number of rows of the grid of the second part (2, 3; 3a; 3c; 13a) is equal to the number of months in a year of the calendar system, and the number of columns of the grid is equal to the number of days of the longest month of the calendar system plus six. A perpetual monthly calendar according to claim 1, wherein the number of days on the first part (1; 1a; 1c; 11a) is equal to one week plus six days, the number of rows of the grid of the second part (2, 3; 3a; 3c; 13c) is equal to five, and the number of columns of the grid is equal to seven. A perpetual calendar according to claim 5, wherein the four rows of the grid closest to the first part contain the days of four consecutive weeks and the fifth row contains three additional days. A perpetual calendar according to any preceding claim, wherein the first part (1c; 11a) is annular and the second part (3c; 13a) is a circular disc located within the first part and rotatable relative to the first part about its central axis (19), the rows of the grid being defined by respective concentric circles and the divisions of the first part and the cells of the rows of the second part being formed by equiangularly-spaced radial lines originating at the central axis. A perpetual calendar according to any of claims 1 to 6, in which the first part is formed as a rectilinear strip and the second part is formed as a grid of orthogonal rows and columns. A perpetual calendar according to claim 8, wherein the rectilinear strip is an endless flexible band (3c), a first section of which extends over the front of the calendar and a second section of which extends behind the calendar. A perpetual calendar according to any of claims 1 to 6, wherein the first (1c) and second (3c) parts are concentric tubes, the divisions of the first part and the grid of the second part being on the outer surfaces of the tubes. A perpetual calendar according to any preceding claim having a cursor (9; 22; 31) for identifying the cell of the grid corresponding to the current day. A perpetual dual calendar comprising a perpetual yearly calendar according to claim 4 in combination with a perpetual monthly calendar according to claim 5 or 6. A perpetual dual calendar comprising first and second calendars each according to claim 7, the first calendar being a yearly calendar and the second calendar a monthly calendar, the dual calendar having transmission means linking the circular calendars for simultaneous rotation at respective speeds appropriate the time periods covered by the calendars. A perpetual calendar according to claim 13, wherein the transmission means comprises a belt and two pulleys. A perpetual calendar according to any preceding claim, wherein a transparent film (14; 14a) extends over the grid of the second part to allow the cells corresponding to selected dates to be marked on the film, the calendar having a further area (16, 17) on which the marked date can be explained in writing. A perpetual calendar according to any preceding claim, comprising a flat board provided with sets of holding points, positioned at the main intersections of the lines of superimposed common symbols, representing the alphanumeric characters, each set of the said holding points comprising at least nine holding points, defining three parallel rows and three columns, differently coloured or shaped displaying means (8) being spread between the holding points to show the first letter of the actual day of the week in one colour and its date in another colour or shape, displayed at the full height and width of the flat board, to allow distant visual reading as well as reading through touch by visually impaired persons.

Inventors: HOYECK RALPH HABER, HOYECK, RALPH HABER
Applicants: HOYECK RALPH HABER, HOYECK, RALPH HABER
Application year: 1989
Main classification: G09D3
IPC codes: G09F3, G09D3