IMPROVEMENTS IN OR ADDITIONS ΤΟ CLOCKS FOR INDICATING THE DATE OF THE GREGORIAN CALENDAR
Year: 1884

page_text: of the Gregorian Calendar.
I, HERBERT JOHN HADDAN, of 67, Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said invention for IMPROVEMENTS IN
OR ADDITIONS ΤΟ CLOCKS FOR INDICATING THE DATE OF THE GREGORIAN
CALENDAR, a communication to me from abroad by the firm of J. Brandt, and
G. W. von Nawrocki, of 124 Leipzigerstrasse, Berlin, Germany, agents for Thomas
Kruczkowski, Organist, of Barloschno, to be as follows :—
This apparatus which indicates the complete date of the Gregorian Calendar is
set in motion by a clockwork from the arbor of the hour-hand.
The apparatus is placed between the going part and the dial plate of a clock.
All its parts are mounted on a base plate situated between the ordinary clockwork
and the dial plate.
This plate or partition is connected with the dial plate by means of stay bolts
and provided in the centre with a sleeve passing through the dial and serving as a
bearing for the arbor of the hour-hand. The arbor of the hour hand carries close
behind the partition a small tooth wheel which gears into another toothwheel of
double the diameter and which will be hereinafter called the day-wheel.
This day wheel makes one complete revolution every 24 hours; its short arbor
Has its pivotal bearings in the partition. This arbor carries at its other end a
star-wheel having three teeth and a second wheel having only one tooth.
The wheel with one tooth gears at each revolution into a ratchet-wheel and
turns the same for the distance of one tooth. This wheel, hereinafter called the
month-wheel, has 31 teeth and is screwed fast or made of one piece with another
wheel having 49 teeth, hereinafter called the 49. teeth-wheel. These two wheels
turn freely on the hub of a disk itself loosely mounted on the sleeve of the
partition.
Under the teeth 29, 30 and 31 of the month wheel there are three movable
levers arranged in corresponding slots of the said two wheels. The levers are

page_text: pivoted on small pins passing across the slots of the two wheels and which are
mounted in recesses situated about the centre of the levers.
These levers are provided at their rear end with a nose by means of which they
engage in the recesses of a wheel mounted behind the 49 teeth wheel. In this
position, the forward ends of the levers protrude through the month wheel. The
levers with their noses are pressed in the recesses situated under the same, by
means of springs.
•
On the hub of the disk, and close to the month wheel, there is also mounted a
wheel, hereinafter called the four-years wheel. The four years wheel is loosely
mounted; it has 48 teeth and is provided on one of its surfaces with a series of
16 holes arranged in pairs around its centre at equal distances from the latter, and
another group of 11 holes arranged in 4 radial sets, three radii having each three
holes, and one radius two holes.
The latter group of holes may also be replaced by 4 radial slots at right angles
to each other and of corresponding length. The holes of these sets or groups
correspond to the position of the noses of the levers and serve in combination with
these levers to set the mechanism on the first day of the months.
•
The mechanism is so arranged that in February the noses of the levers engage
in the radially arranged holes or slots, in March the noses are situated between
the radial holes and the circumferential holes, in April they engage in one of the
circumferential holes.. The four years wheel is further provided on the inside
with a ring wheel of the same diameter and having 50 teeth.
The ring wheel or toothed ring is adapted to turn freely on the projecting
central part of the 4 years wheel and is held in position by a disc which is
screwed' on.
This toothed ring has a projecting pin which at each revolution of the ring turns
a pinion for the distance of one tooth; this pinion has four teeth and is mounted
on its arbor sideways of the four years wheel. The arbor of this pinion passes
through the four years wheel and carries at its other end a small disc sunk into
the four years wheel and having three notches placed at an angle of 45° to each
other. The four teeth pinion and disc are arrested in each of their positions by a
spring acting as a pawl. The four years wheel gears on the one hand jointly with
the ring, wheel into a small pinion pivoted to a large disk opposite the base plate
and hereinafter called cover plate and on the other hand jointly with the 49 teeth!
wheel into a pinion pivoted to the partition or base plate. The two last mentioned
pinions have each 8 teeth.
Next to the coverplate there is also a ratchet-wheel mounted loosely on the
sleeve or hub of the partition.
The hub of this ratchet wheel passes through the dial plate and carries a hand
serving to indicate the date.
The ratchet wheel is held in all it's positions by a pawl fixed to the partition.
The ratchet wheel is held so that it can turn in neither direction without
previously being disengaged from the pawl.
The ratchet wheel receives intermittent motion from the coverplate by means of
a spring secured to the said plates.
In order to allow this spring the necessary play the ratchet wheel is recessed.
The above described mechanism works as follows:
°
The clockwork turns the pinion of the day wheel twice round within 24 hours
by means of the hour-wheel and its arbor and the said pinion turns the day wheel,
(which has twice as many teeth as the pinion) once round within 24 hours.
Simultaneously with the day-wheel the wheel which has only one tooth is also
turned round once, thereby turning the. month wheel (having 31 teeth) for one
tooth.
The month wheel is thus turned for one tooth in 24 hours. The motion of the
month wheel is imparted through the auxiliary or 49 teeth wheel to a pinion which
gears into and turns the four-years wheel having 48 teeth. The latter wheel is
☑

page_text: thus turned for one tooth every month and as it has one tooth less (48) than the
49 teeth wheel which imparts the rotary motion to the pinion of the month
wheel the latter will make one turn more than the 49 teeth wheel within four
years. For the month of February the month or 48 teeth wheel is set so that the
first set of three superposed holes or the slot are placed accurately under the ends
of the three levers mentioned above.
The springs cause the levers to engage in the said holes while the other ends of
In this position the
the levers protrude from the month or 31 teeth wheel.
28th of February has approached. On this day the 31 teeth wheel is turned within
the first 18 hours for the 29th 30th and 31st tooth by means of the spur wheel
mounted on the arbor of the day wheel as mentioned above and the three teeth of
Within the last
which engage with the protruding ends of the three levers.
6 hours, however, the one tooth wheel engages with its tooth the tooth No 1 of the
month wheel and thus sets the latter on the 1* of March. Between the 5th and the
25th of March the four years wheel changes its position relatively to the 31 teeth
or month wheel and the auxiliary wheel owing to the different pitch of the teeth of
the four years wheel and the auxiliary wheel, in consequence of which the ends
of the levers are simultaneously disengaged from the holes of the four years wheel
and the ends of the levers again recede into the month-wheel. The month wheel,
and auxiliary wheel are turned during the whole month of March solely, by the
tooth of the one tooth wheel.
In the mean time the four years wheel and the month wheel and auxiliary wheel
again alter their position relatively to each other so that in April the end of the
lever engages in the next hole of the month wheel.
The end of the lever consequently protrudes from the 31 teeth wheel and on the
30th of April the month wheel and the auxiliary wheel are turned within the 12th
and 18 hours by the spur wheel for the 31" tooth and set on the 1st of May within
the last six hours by the tooth of the one tooth wheel. In this manner the
mechanism continues to work during the other months and during the second and
third year. In the fourth year, however, when February has 29 days and in the
leap years 1700, 1800 and 1900, when February has 28 days while in the year 2000
when February again has 29 days, the mechanism is set in the following manner :
The four years wheel having 48 teeth and which turns round once in four years,
gears into the pinion having 8 teeth, which is pivoted to the coverplate, and
imparts its motion through the above mentioned pinion to the ring wheel having
50 teeth. The ring wheel thus remains within four years for two teeth behind the
four years wheel in consequence of which it makes one turn less than the four
years wheel within 100 years. In the leap year 1700 the wheel with the projecting
pin turns the first tooth of the 4 tooth pinion only half way owing to which the
first notch of the disc is placed in front of the radially arranged holes of the four
years wheel,
In this manner an opening is left for the end of the third lever in the year 1700;
the three levers protrude with their ends from the month-wheel; and the double
wheel is set by the spur wheel from the 28th of February on the 1st of March.
After some months the projecting pin p' fully turns the step of the four toothed
pinion and the notch of the disk is placed sideways out of the direction of the
radially arranged holes of the four years wheel.
In the following years the uppermost hole of the radial set of holes is covered by
the four tooth wheel so that at this place only two holes are brought into play
corresponding to the 29 days of February.
In the years 1800 and 1900 the same takes place as in the year 1700, in the
year 2000, however, when February has again 29 days the uppermost that is to say
the third hole must again be covered, notwithstanding that the 4 tooth wheel has
only been turned half a division (length of pitch) by the projecting pin.
This is effected by omitting the notch of the disk (coupled with the four tooth
wheel) at this place.

page_text: The date is indicated by the day hand mounted on the hub of the ratchet wheel.
The latter has 31 teeth and is set in motion by the coverplate which, within
24 hours is turned for * of a revolution that is to say for 1 tooth by means of the
one tooth wheel.
In order to turn the day hand intermittently the ratchet wheel is held by the pawl 5
until the day wheel has been turned for one tooth by the one tooth wheel. This
stretches the spring and as soon as the pawl is thrown out of gear the ratchet
wheel follows the cover plate. The rotary motion of the ratchet-wheel is limited by
a pin of the cover plate.

page_text: of the Gregorian Calendar.
I, HERBERT JOHN HADDAN of 67, Strand, in the City of Westminster, Civil
Engineer, do herby declare the nature of said invention for IMPROVEMENTS IN
OR ADDITIONS TO CLOCKS FOR INDICATING THE DATE OF THE GREGORIAN CALENDAR,
a communication to me from abroad by the firm of J. Brandt and G. W. von
Nawrocki, of Berlin, agents for Thomas Kruczkowski, Organist, of Barloschno,
Empire of Russia, and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
This apparatus, which indicates the complete date of the Gregorian Calendar, is
set in motion by a clockwork from the arbor of the hourhand.
In describing this invention, reference will be made to the accompanying
drawing, in which Fig. 1. is a front view, Fig. 2 a back view, and Fig. 3 a side
view of the apparatus, while Fig. 4. is a vertical section and Figs. 5 and 6 are
sections, showing the acting part in various positions.
The apparatus is placed between the going part and the dial plate of a clock.
All its parts are mounted on a base plate A, situated between the ordinary clock-
work and the dial plate.
This plate or partition A is connected with the dial plate B, by means of stay
bolts, and provided in the centre with a sleeve a, passing through the dial B and
serving as a bearing for the arbor b of the hourhand C. The arbor of the hour-
hand C carries close behind the partition A a small tooth-wheel d, which gears
into another tooth wheel e of double the diameter, and which will be hereinafter
called the day-wheel.
This day wheel makes one complete revolution every 24 hours; its short arbor e¹
has its pivotal bearings in the partition A. This arbor e¹ carries at its other end,
close to each other, a star wheel f, having three teeth and a second wheel f¹, having
only one tooth (Figs. 4, 5, 6, 8 and 10).
The wheel f¹ with one tooth, gears at each revolution into a ratchet-wheel g,
and turns the same for the distance of one tooth. This wheel g, hereinafter called
the month wheel, has 31 teeth and is screwed fast or made of one piece with
another wheel g¹, having 49 teeth, herein after called the 49 teeth wheel. These
two wheels g g turn freely on the hub of a disc h itself loosely mounted on the
sleeve a of the partition A.
•
Under the teeth 29, 30 and 31 of the month wheel g there are three
movable levers i, ¹³, arranged in corresponding slots of the said two wheels g g'
(Figs. 10 & 11). The levers i are pivoted on small pins k, passing across the
slots of the two wheels g g¹, and which are mounted in recesses, situated about
the centre of the levers iii, as shown in Fig. 1.
These levers are provided at their rear end with a nose l, by means of which
they engage in the recesses of a wheel n, mounted behind the 49 teeth wheel g¹.
In this position, represented in Fig. 11, the forward ends m of the levers protrude
through the month wheel g. The levers, with their noses 1, are pressed into the
recesses, situated under the same, by means of springs g³.

page_text: On the hub of the disc h and close to the month wheel g, there is also mounted
a wheel n, hereinafter called the four years wheel. The four years wheel n is
loose; it has 48 teeth and is provided on one of its faces with a series of 16 holes n',
arranged in pairs around its centre, at equal distances from the latter; and another
group of 11 holes, n³, arranged in 4 radial sets.
The latter group of holes may also be replaced by 4 radial slots at right angles
to each other and of corresponding length as indicated in Fig. 9 by dotted lines.
The holes n¹ and n³ correspond to the position of the noses of the levers i i¹ **
and serve, in combination with these levers, to set the mechanism in the first day
of the months.
The mechanism is so arranged, that in February the noses of the levers i i¹ i³
engage in the radially arranged holes or slots n², in March the noses are situated
between n³, and the nearest hole n', in April they engage in one of the circum-
.ferential holes n¹, as indicated in Fig. 9. The four years wheel n is further
provided on the inside with a ring-wheel p of the same diameter, and having
50 teeth.
The ring wheel or toothed ring p is adapted to turn freely on the projecting
central part of the four years wheel n and is held in position by a disc p', which
is screwed on, (Figs. 4, 7 and 8).
This toothed ring p has a projecting pin p³, which, at each revolution of the
ring p, turns a pinion g for the distance of one tooth; this pinion q has four teeth
and is mounted on its arbor sideways of the four years wheel n. The arbor q³.of
this pinion passes through the four years wheel n and carries at its other end a
small disc gl, sunk into the four years wheel n and having three notches 93, placed
at an angle of 45° to each other. The four teeth pinion g and disc q' are arrested in
each of their positions by a spring 2 (Fig. 7) acting as a pawl. The four years
wheel n gears on the one hand jointly with the ring wheel p into a small pinion o,
pivoted to a large disc h opposite the base plate and hereinafter called cover plate,
and on the other hand jointly with the 49 teeth wheel q¹ into a pinion », pivoted
to the partition or loose plate A. The two last mentioned pinions o and r have
each 8 teeth.
Next to the cover plate h, there is also a ratchet-wheel 8, mounted loosely on the
sleeve or hub a of the partition A. The hub of this ratchet-wheel s passes through
the dial plate B and carries a hand D, serving to indicate the date. The ratchet-
wheels is held in all its positions by a pawl s¹, fixed to the partition A. The
ratchet-wheel is held so that it can turn in neither direction without previously
being disengaged from the pawl s¹.
The ratchet-wheel s receives intermittent motion from the coverplate h by means
of a spring t, secured to the said plate h. In order to allow this spring t the
necessary play, the ratchet wheel s is recessed, as represented in Figs. 5 and 6.
The above described mechanism works as follows:
The clockwork turns the pinion of the day wheel & twice round within 24 hours
by means of the hour wheel and its arbor b, and the said pinion & turns the day
wheel e, which has twice as many teeth as the pinion d, once round within
24 hours.
Simultaneously with the day wheel e, the wheel f¹, which has only one tooth, is
also turned round once, thereby turning the month wheel g, having 31 teeth, for
one tooth in the direction of the arrow. (Figs. 5 and 10). The month wheel g is
thus turned for one tooth in 24 hours.
The motion of the month-wheel g is imparted through the auxiliary wheel g¹,
having 49 teeth, to the pinion r, which gears into and turns the wheel n, having
48 teeth. The latter wheel n is thus turned for one tooth every month, and as it
has one tooth less (48), than the 49 teeth wheel g¹, which imparts rotary motion to
the pinion r, it will make one turn more, than the 49 teeth wheel g¹ & g within four
years. For the month of February the month-or 48 teeth wheel n is set so, that
the first set of three superposed holes or the slot n² (at I Fig. 9) are placed
accurately under the ends of the three levers i¹ i², mentioned above,

page_text: The springs g³ cause the levers to engage in the said holes n², while the other
ends m of the levers protrude from the month-or 31 teeth-wheel g (Fig. 11). In
this position the 28th of February has approached. On this day the 31 teeth
wheel g is turned within the first 18 hours for the 29th 30th and 31th tooth by
means of the spur wheel f, mounted on the arbor of the day wheel e as mentioned
above, and the three teeth of which engage with the protruding ends m of the
three levers i, . Within the last 6 hours, however, the one tooth wheel f¹
engages with its tooth the tooth No 1 of the month wheel g and thus sets the latter
on the 1st of March. Between the 5th and the 25th of March the four years wheel n
changes its position relatively to the wheels g g', owing to the different pitch of the
wheels n and g', in consequence of which the ends of the levers i¹³are simul-
taneously disengaged from the holes n² of the wheel n, and the ends m of the levers
again recede into the month wheel g. The month wheel and auxiliary wheel g g'
are turned during the whole month of March, solely by the tooth of the one tooth
wheelf. In the mean time the four years wheel n and the month wheel and
auxiliary wheel g g again alter their position relatively to each other, so that in
April the end of the lever i engages in the next hole n¹ of the month wheel n.
The end m of the lever consequently protrudes from the 31 teeth wheel g and
on the 30th of April the wheels g g are turned within the 12th and 18th hours by a
tooth of the star wheelf for the 31st tooth and set on the first of May within the
last six hours, by the tooth of the one tooth wheel f¹.
.
In this manner the mechanism continues to work during the other months and
during the second and third year.
.
In the fourth year, however, when February has 29 days and in the leap
years 1700, 1800 and 1900, when February has 28 days, while in the year 2000,
when February again has 29 days, the mechanism is set in the following manner.
The four years wheel n, having 48 teeth, and which turns round once in four
years, gears into the pinion o having 8 teeth, which is pivoted to the coverplate h,
and imparts its motion through the pinion o to the ring wheel p, having 50 teeth.
The ring wheel thus remains within four years for two teeth behind the four years
wheel n, in consequence of which it makes one turn less, than the four years
wheel n within 100 years. In the leap year 1700, the wheel p with the projecting
pin p' turns the first tooth of the four tooth pinion only half way, owing to which
the first notch of the disc q' is placed in front of the radially arranged holes n³,
at IV, Fig. 9. In this manner an opening is left for the end of the third lever i
in the year 1700; the three levers protrude with their ends from the month
wheel'g, and g g' is set by the spur wheel fas described above from the 28th of
February on the 1st of March.
After some months the projecting pin p² fully turns the tooth of the four
toothed pinion q, and the notch of the disc q' is placed sideways out of the direction
of the radially arranged holes n. In the following years the uppermost hole of
the radial set * IV is covered by the four teeth wheel q, so that at this place only
two holes are brought into play, corresponding to the 29 days of February. In the
years 1800 and 1900 the same takes place, as in the year 1700; in the year 2000
however, when February has again 29 days, the uppermost, that is to say the third
hole n IV Fig. 9, must again be covered, notwithstanding that the wheels q q¹ have
only been turned half a division (length of pitch) by the projecting pin p².
This is effected by omitting the notch of the disc q' at this place.
The date is indicated by the day hand D, mounted on the hub of the ratchet-
wheel 8.
The latter has 31 teeth and is set in motion by the. cover plate h, which,
within 24 hours, is turned together with o, n p² g¹ for of a révolution, that is
to say, for 1 tooth by means of the one tooth wheel. In order to turn the day
hand D intermittently, the ratchet-wheel a is held by the pawl a¹, until the day
wheel g has been turned for one tooth by f¹. This strains the spring t (Fig. 6),
and as soon as the pawl s' is thrown out of gear, the ratchet-wheels follows the
cover plate h. The rotary motion of the ratchet-wheels is limited by a pin a of
the cover plate h..
8
•

page_text: Fig. 6 shows the position of the ratchet-wheel 8 at the moment, when the pawl s¹
is being thrown out of gear. The pawl s² is thrown out of gear by a pin v of the
wheel e, which at midnight presses against an arm s² of the pawl a'. This calendar
shows the correct date for 10000 years.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim, is
1. An attachment to a clock, serving to show the complete date of the Gregorian
Calendar and adapted to be set in motion by the hour wheel of the clock, said
mechanism comprising the wheels d, e, f, fi; the wheels g, g¹, provided with
levers i, i, 2; the annular wheel p, the wheel n, provided with pinions q, q' and
apertures n' n³, said wheel gearing, on the one hand in conjunction with p, into
the pinion o; further the disch with spring t and pin u; the wheels with pawl 8¹
and hand D.
2. In a calendar mechanism, the combination of wheel n, having holes n², n³, 1
with levers i, i, i, situated in the wheel g g¹ for indicating or setting the months.
3. A wheel n having an annular wheel p with pin p³, and pinions q q³, mounted
on the same axle q³, in combination with the pinion o, for the purpose of setting
in every century the February with 28 days, and in every fourth century the
February with 29 days.