IMPROVEMENTS IN DATE CALENDARQ
Year: 1880

page_text: LETTERS PATENT to David Ross, of Crutched Friars, in the City of London,
and County of Middlesex, for an Invention of "IMPROVEMENTS IN DATE
CALENDARQ "
PROVISIONAL SPECIFICATION left by the said David Ross at the Office
of the Commissioners of Patents on the 31st July 1880.
DAVID Ross, of Crutched Friars, in the City of London, and County of
Middlesex. "IMPROVEMENTS IN DATE CALENDARS."
My improved calendar consists essentially of a case or frame, and two faces or
equivalent, one, which may be placed either above or below to suit convenience,
is marked like a clock face, but with the names of the months in place of the usual
figures, and provided with an index hand and button, or the like, to turn it by.
This index hand can be turned to point to any month, and its spindle is connected
within the frame or case with a toothed wheel, which in the model I have made
has 28 teeth, and a space sufficient to allow the index hand to travel from February
to March without actuating any other part of the mechanism, as will presently
appear. The number of teeth in this wheel may be varied in a certain proportion,
so I do not bind myself to use 28 teeth only. The second "face" I form in the
segment of a circle, at the periphery of which upon a movable circular card, or the
like, appear the names of the days of the week, and nearer the centre are arranged
the numbers representing the days of the month, in the segments of five concentric
circles, so that commencing to read at the left side nearest the periphery, one finds
the figure 1 and reaching to 7 upon the first line, 8 to 14 upon the second, 15 to
21 upon the third, 22 to 28 upon the fourth, and 29 to 31 upon the fifth and
smallest line. Now supposing the name card to be turned round, so that Sunday
comes above the first figure, then the Sundays would be the 1st, 8th, 15th, 22nd, and
29th of the month; the Mondays, 2nd, 9th, etcetera.
This arrangement will be well understood.
The figures representing the days of the month are fixtures, while the card
carrying the names of the days of the week is circular and capable of revolving
upon its centre, and is connected to another toothed wheel which is driven by the
former toothed wheel. In my model, the second toothed wheel has 21 teeth, but this

page_text: number also may be altered, bearing in mind that the number must always be some
multiple of 7; thus 28 would be a very good number of teeth for it. Each tooth of
this wheel may point towards one of the days of the week upon the periphery of
the card to which this wheel is attached. Now to explain the working of this
apparatus, I will take this present year, and the index hand pointing to January,
the revolving card places the name Thursday at the head of the list containing 1, 8,
etcetera, giving all the Thursdays in the month; Friday comes opposite 2, 9, etcetera,
and the other days in due order. Upon turning the hand to February, it will be
found that the revolving card has turned to Sunday for the first of February, the
other days being arranged in proper order for that month. The index band will
now be free to turn between the months of February and March upon its dial
without moving the revolving disc, so that Sunday still remains the first of the month
(March), which would have been correct had February only had the usual number
of 28 days; the hand moves free because the space upon the periphery of its wheel
where there are no teeth has come opposite to the other wheel, and so no movement
take place. This year however, being leap year, and February having 29 days, it
is requisite to turn the index hand one entire revolution, bringing it round to
March again, when the day of the week will be found to have changed to Monday,
which is correct.
Turning the index band to April, we find that Thursday was the first, and going
on to August we get Sunday as the first, and December, Wednesday the first;
continuing to January 1881, we have Saturday as the first, and Tuesday as the
first of both February and March, which is correct, so that by merely turning the
index round and making allowance for leap years, we can find any desired day of
the week and month for future years; the same applies also to past years, the
proper allowances being made.
The year also may be introduced by adding the requisite wheels. Ono way of
doing this would be to have four wheels arranged beside each other and partly over-
lapping, carrying figures upon their faces; at the periphery these would carry each
a ten-toothed pinion, and have a suitable projection to take into the teeth of the
pinions as in an ordinary gas meter; the train of wheels can be worked either from
the wheel upon the spindle of the index hand, or may be worked independently by a
button or otherwise from outside the case,
The apparatus as above described, minus the wheels for the year, is a simple
form, but the turning the index hand round for leap year may be obviated by
providing an extra tooth, or its equivalent, upon or in connection with the wheel of
the index hand; this is kept out of gear for the ordinary years, but every fourth
year the tooth is released, and so catching a tooth upon the other wheel turns the
week disc one day farther on between February and March, thereby making it
correct.
I have described the revolving disc as appearing above or beyond the face
carrying the figures of the days of the month, but it can be made to work inside
(that is, nearer the common centre from which both are struck) if preferred.
Another modification is to place the two faces in one, or nearly so, and have the
index band and wheel as usual, and the wheel for actuating the revolving disc, like
a thin barrel, with the teeth upon the inside instead of the outside, as previously
described. .
If preferred also the index hand may be dispensed with, the name of the
month being depicted upon the side of the wheel, and appearing to view through a
suitable opening in the case.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Ross in the Great Seal Patent Office on the 31st January
1881.
DAVID Ross, of Crutched Friars, in the City of London, and County of
Middlesex. "IMPROVEMENTS IN DATE CALENDARS."
My improved calendar has a case or frame, and two faces or equivalent, one,
which may be placed either above or below to suit convenience, is marked like a
clock face, but with the names of the months (but at varying distances, as herein-
after described) in place of the figures, and provided with an indexhand and button
or the like to turn it by. This indexhand can be turned to point to any month, and
its spindle is connected within the frame or case with a toothed wheel, which, in
the model I have made, has 27 teeth and a toothless space sufficient to allow the
indexhand to travel from February to March without actuating any other part of
the mechanism, as will presently appear. In some cases this toothless space may be
dispensed with by putting the names February and March upon the same division
upon the face D; when this is done no movement is needed between February &
March. The number of teeth in this wheel may require to be varied from 27 to 29
to suit the gearing or depth of gearing employed, so I do not bind myself to use
27 teeth only. The second "face" I form in the segment of a circle, at the
periphery of which upon a movable circular card or the like appear the names of
the days of the week, and nearer the centre are arranged the numbers representing
the days of the month in the segments of five concentric circles, so that commencing
to read at the left side nearest the periphery, one finds the figure 1, and reaching
to 7 upon the first line, 8 to 14 upon the second, 15 to 21 upon the third, 22 to 28
upon the fourth, and 29 to 31 (the odd numbers over the even 4 weeks) upon the
fifth and smallest line. Now, supposing the name card to be turned round so that
Sunday comes above the first figure, then the Sundays would be the 1st, 8th, 15th,
22nd, and 29th of the month; the Mondays 2nd, 9th, etcetera.
The figures representing the days of the month are fixtures, while the card
carrying the names of the days of the week is circular or polygonal, and capable of
revolving upon its centre, and is connected to another toothed wheel which is
driven by the former toothed wheel. In my model the second toothed wheel has
12 teeth, but this may be altered to some other convenient multiple of 7 from 14
upwards; thus 28 would be a very good number of teeth for it. The periphery of
the card or disc is divided into as many equal parts as this wheel has teeth. Each
of these parts bears the name of one of the days of the week in regular order, so
that there are as many sets of 7 days on the card as there are multiples of 7 teeth
in the wheel.
Now to explain the working of this apparatus, I will take this present year
(1880), and the indexhand pointing to January, the revolving card places the name
Thursday at the head of the list containing 1, 8, etcetera, giving all the Thursdays
in the month. Friday comes opposite 2, 9, etcetera, and the other days in due
order. Upon turning the hand to February it will be found that the revolving card
has turned to Sunday for the first of February, the other days being arranged in
proper order for that month. The indexhand will now be free to turn between the
months of February and March upon its dial without moving the revolving disc, so
that Sunday still remains the first of the month (March), which would have been
correct had February only had the usual number of 28 days; the hand moves free
because the space upon the periphery of its wheel where there are no teeth has
come opposite to the other wheel, and so no movement takes place. This year
however, being leap year, and February having 29 days, it is requisite to turn the
indexhand one entire revolution, bringing it round to March again, when the day

page_text: of the week will be found to have changed to Monday, which is correct. This
change is effected because the number of teeth in the driving or indexwheel is such
that, in making one complete revolution, it causes the wheel bearing or directly
actuating the card or disc to move round 29 teeth, so that at the close of each
revolution of the indexwheel, 4 sets of 7 days and one day more have passed the
opening. This is a very important feature in this improved calendar.
Turning the indexhand to April, we find that Thursday was the first, and going
on to August we get Sunday as the first, and December, Wednesday the first.
Continuing to January 1881, we have Saturday as the first, and Tuesday as the
first of both February and March, which is correct, so that by merely turning the
indexhand round, and making allowance for leap years, we can find any desired
day of the week and month for future years; the same applies also to past years,
the proper allowances being made.
The apparatus, as above described, is a simple form, but the turning the index-
hand round for leap year may be obviated by providing an extra tooth or its
equivalent upon or in connection with the wheel of the indexhand; this is kept
out of gear for the ordinary years, but every fourth year the tooth is released or
otherwise brought into use, and so catching a tooth upon the other wheel, turns the
week disc one day farther on between February and March, thereby making it
correct.
The year also may be introduced by adding the requisite wheels; one way of
doing this would be to have four wheels arranged beside each other and partly
overlapping, carrying figures upon their faces at the periphery; these would carry
each a ten toothed pinion, and have a suitable projection to take into the teeth of
the pinions; this train of wheels can be worked either from the wheel upon the
spindle of the indexhand, or may be worked independently by a button or
otherwise from outside the case, the former plan being much preferable.
I have described the revolving disc as appearing above or beyond the face
carrying the figures of the days of the month, but it can be made to work inside
(that is, nearer the common centre from which both are struck) if preferred.
Another modification is to place the two faces in one, or nearly so, and have the
indexhand and wheel as usual, and the wheel for actuating the revolving disc,
like a thin barrel, with the teeth upon the inside instead of the outside, as previously
described.
If preferred also the index hand may be dispensed with, the name of the mouth
being depicted upon the side of the wheel, and appearing to view through a suitable
opening in the case.
Reference being now had to the accompanying Drawings, in which like letters
represent like parts. Fig. 1 is a front elevation of one form of the calendar as it
would hang on the wall or stand upon the desk or table; Fig. 2, a sectional side
elevation of the same; Fig. 3, a view of the interior of the case, the front plate on
which are the "faces," and the indexhand and knob being removed; Fig. 4 is a
view of the indexwheel and movable tooth, the wheel is broken, one portion
showing one side of the wheel and the other portion showing the other side, the
movable tooth appearing in both portions, although of course in the actual wheel
there is only one; Fig. 5 is a side view of the indexwheel with movable tooth,
spindle, or arbor and pinion.
A is the case of the machine and B the front plate, provided with "faces "C
and D and openings E for the figures which represent the year; C¹ is part of the
revolving disc, and has the names for one week now exposed to view. C has the
numbers for the days of the month arranged in five lines, each line being the
segment of a circle; the first line carries the numbers 1 to 7, the second 8 to 14,
and so on up to 31, as shown. Face D is self explanatory; the indexhand D¹
pointing to any month according as it is turned by the knob D2 or in some
equivalent manner. The distances between the months vary according to the
number of days in the preceding month. The circumference of face D being
divided into 32 equal parts (the number of teeth of the indexwheel, if complete)

page_text: the distance from January to February is made equal or proportionately equal to 3
of these parts, because upon the smallest of the segments of concentric circles of
face C are 3 dates, 29, 30, and 31 (the odd days over the even 4 weeks), and the
card or disc must be moved 3 days to bring the day which is opposite the blank
space following 31 back to the figure indicating the 1st, therefore February on
face D must be spaced 3 divisions or spaces from January, this will be readily seen
upon reference to Fig. 1 of the Drawings. The distance from February to March
is the same, 3 parts or divisions; but this distance would require to be varied to
suit the altered number of omitted teeth in the indexwheel, and correspondingly
altered number of divisions of the face, supposing such alterations to be made. The
other distances remain relatively invariable. From March to April the distance is
made equal to 3 parts, for the same reason that January to February is equal to
3 parts. April to May has only 2 parts, because April ending with the 30th the
card C¹ need only be moved 2 days to bring the day from the 31st back to first
for May. The other months are spaced in like manner, according as they have 3
or 2 days over the 4 weeks. These relative distances are another important feature
in this Invention. The arrows indicate the direction in which each part moves
when the index being turned forward; if turned back the motions would all be
reversed.
The index wheel F is shown at Fig. 4; this wheel, as shown here, would if
complete have 32 teeth, or more correctly 31 and a movable one, but owing to the
four teeth omitted at F it has only 27, and a movable one F³. One method of
actuating this movable tooth is shown in this view. A small diamond shaped
plate F upon the underside of the wheel (shown in full lines in the lower half of
the wheel, which is reversed for clearness, and in dotted lines in the upper half) is
secured to the tooth F3, and a spring plate F is secured to the tooth and presses
on the other side of the wheel. Two studs G₁ are fixed in a plate or bridge G
standing under the index wheel, and a stud H projects from the side of stud
wheel H, which is driven by pinion I upon the arbor of said indexwheel. Stud
wheel H. and stud H' make only one revolution to four of the index wheel F;
the gearing employed is immaterial so long as the ratio is preserved, but in the
Drawing pinion I has 15 teeth and stud wheel H 60. Stud wheel H therefore
makes but one revolution for four years, while index wheel F makes one revolution
for one year. When the stud His at the greatest distance from the centre of
indexwheel F, the edge of the diamond plate F³ touches it, and being pressed
against it has to give way, the result being that the tooth F2 is forced out as in the
lower half of Fig. 4. As the wheel turns on the diamond plate comes into contact
with one of the studs G¹ and is forced back, and the tooth withdrawn in the same
manner. This action only takes place at leap year; during the other three years
the stud His clear of the diamond plate, which as it remains in is in its turn
clear of the studs G₁. The positions of these studs and plate are clearly indicated
in Figs. 3 and 4.
The "day" wheel K. which carries the circular disc C¹ has no unusual features;
it has 21 teeth in the Drawing, but might have 28 teeth, or some other convenient
multiple of 7. It is held from turning when not moved purposely by the spring
catch K' or other equivalent device.
As an alternative arrangement of the face D and its corresponding gearing, this
face could be divided into four segments, each segment marked with the 12 months
for one year, for 1st, 2nd, 3rd, and 4th (or leap) years, and to suit this the index
wheel would also be larger, and have four groups of teeth (the one for leap year
having one extra tooth) with suitable spaces between, or a continuous succession
of teeth around the periphery, February and March being then placed for the
ordinary years on the same line, or exactly 7 days (that is, a distance sufficient to
allow the card C¹ to be moved 7 days round) apart, and one day apart for the leap
year; as however this very unequal spacing would be unsightly I prefer the former
arrangement with the teeth of the wheel in groups. In this case also instead of
having an indexhand the side or face of, the wheel itself can be divided and

page_text: marked for the 4 years, the names of the months appearing to view through
suitable opening; but the indexhand is better, as showing which year of the series
is on view. This arrangement though involving a proportionately larger index-
wheel has the advantage of extreme simplicity, and dispenses with the movable
tooth and its mechanism. When this large wheel is employed the first wheel of
the year train will of course require to be moved 4 teeth for each revolution of the
indexwheel instead of only one.
For indicating the year, four wheels are used bearing figures upon their sides, or
upon discs attached to their arbors; they are each numbered alternately 0 to 9
and 0 to 9, and a complete revolution of the first of the series moves the second on
one figure or tooth. The second moves the third in a similar manner, and the third
moves the fourth. Suitable openings are provided in the front plate to allow of
the figures being seen. When worked, as I prefer, from the other mechanism, the
first wheel must move one tooth or figure for one revolution of the index wheel F.
In the Drawing this is done by a wheel L (Fig. 3) driven by pinion I, and driving
another pinion L' at the same rate as pinion I; pinion L¹ gears with another
pinion L of like size fixed upon the arbor of disc M, carrying a stud M³, which
moves the first wheel of the year train one tooth for each revolution which it
makes. As, however, the stud M¹ has to make one revolution to one of the index
wheel, it could with advantage, when the arrangement admits of it, be placed upon
the index wheel itself, and so save the intermediate gearing. Spring catches N
keep these year wheels from moving except when required to do so.
arrangement for indicating the year is not new, and is well understood.
This
As shown in Fig. 1, the calendar represents January 1881, the Saturdays being
1, 8, 15, 22, 29, the Sundays 2, 9, 16, 23, 30, and the other days of the week as
shown. Turning the index D' to February, the disc revolves three teeth, equal to
three days, and so gives Tuesday as the 1st of February. Turning on the index
to March, the plain part of the index wheel is reached, and therefore no movement
of the revolving disc C¹ takes place, and it remains correctly at Tuesday for the
1st March also. Had the year 1881 however been leap year, the sliding tooth would
have been pushed forward (assuming, of course, that the parts had been properly
set to start with) and gearing with the day wheel k, which works the revolving
disc, would have turned that on one tooth, that is, one day, and it would then have
represented Wednesday the 1st March.
Having now described my Invention, and the method of performing the same, I
wish it to be understood that I do not confine myself to the exact details of
construction previously enumerated, as these could be considerably varied without
departing from the essential features of my Invention (for instance, the shape and
construction of the case, the relative position and size of the faces, and to some
extent the figures or symbols upon them, the mechanism for actuating the figures
which indicate the year, and the means for actuating the movable tooth, are all
susceptible of variation, and are merely set down here as being, what I believe to
be, the most satisfactory way carrying out my Invention); but that what I do
claim and desire to protect under the hereinbefore in part recited Letters Patent
is,―
First. In a date calendar, the combination of the two "faces" (or equivalent
devices) D, with or without its index hand D¹ and C, with its revolving card or
equivalent device C¹ so connected together or mutually actuated, that for each
ordinary revolution or part of a revolution representing an ordinary year, of the
indexhand or wheel, the revolving card or equivalent device C¹ shall have presented
to view one day more than any multiple of seven days; and for every fourth
revolution of said indexband or wheel, or part of a revolution representing a
fourth or leap year, the said revolving card or equivalent device C shall have
presented to view two days more than any multiple of seven days, substantially as
and for the purposes set forth and shown.
Second. In a date calendar the employment in combination with the face C and
revolving card C¹ of the face D, bearing the names or abbreviations of the names

page_text: of the twelve months of the year, or of the months of four complete years differentially
spaced around or upon it, said differential spacing being arranged in proportionate
ratio with the connecting gearing or mechanism according as each month has exactly
four weeks, or three or two days more than four weeks, substantially as and for the
purposes set forth and shown.
Third. As a gearing or mechanismn for connecting or actuating the indexhand D
and revolving card C₁ or their equivalents in a date calendar, the combination of
the indexwheel F minus certain teeth, and provided with one movable tooth or
equivalent device which only comes into use once in every four revolutions of said
indexwheel, with the day wheel K gearing with said indexwheel, and having 21
teeth or other convenient multiple of 7, substantially as and for the purposes set
forth and shown.
Fourth. In a date calendar the employment of the movable tooth F* or its
mechanical equivalent coming into operation once only for every four years,
indicated by the calendar for the purpose of allowing for an extra day in the month
of February in each leap year, substantially as set forth.
Fifth. In a date calendar tho employment of the fixed studs G¹, revolving
stud H, and diamond shaped plate F³ as an actuating mechanism for the movable
tooth F, substantially as and for the purposes set forth and shown.
Sixth. In a date calendar the combination of the indexwheel F having four
separate groups of teeth (one of said groups having one tooth more than the other
three groups) and suitable spaces between; the face D, divided into four segments
each bearing the names of the months for a whole year, and day wheel K. gearing
with said indexwheel, substantially as and for the purposes set forth.
Seventh. In a date calendar the combination of face D divided into four
segments, in three of which the names of the months February and March are
placed on the same line or division, or a distance apart equal to a travel of seven
days of the revolving card C' or its equivalent, and in the fourth segment the said
names February and March are placed a distance apart equal to a travel of one
day of the revolving card C', the indexwheel F having a complete succession of teeth
round its periphery, and the day wheel K, substantially as and for the purposes set
forth.
Eighth. The hereindescribed simple form of date calendar consisting essentially
of faces D and C or equivalent and their attendant mechanism, so arranged and
constructed that for every revolution of the indexhand or wheel, the revolving card
or equivalent device C shall have presented to view one day more than any
multiple of seven days, the extra day in leap year being provided for by one extra
complete revolution of said indexhand or wheel, substantially as set forth.
In witness whereof, I, the said David Ross, have hereunto set my hand and
seal, this Thirty first day of January, in the yer of our Lord One thousand
eight hundred and eighty one.
Witness,
ALFRED J. BOULT,
of the Firm of Wm. P. Thompson & Co.,
Patent Agents,
London & Liverpool.
DAVID ROSS. (L.S.)