AN IMPROVED CALENDAR CLOCK MOVE- MENT
Year: 1879

page_text: LETTERS PATENT to Jacob Merzbach, of Holborn Viaduct, in the City of
London, for the Invention of "AN IMPROVED CALENDAR CLOCK MOVE-
MENT." A communication from abroad by Erhardt Junghans and Arthur
Junghans, both of Schramberg, Germany.
PROVISIONAL SPECIFICATION left by the said Jacob Merzbach at the Office
of the Commissioners of Patents on the 26th July 1879.
JACOB MERZBACH, of Holborn Viaduct, in the City of London. "AN IMPROVED
CALENDAR CLOCK MOVEMENT." (A communication from abroad by Erhardt Jung-
hans and Arthur Junghans, of Schramberg, Germany.)
This improved calendar clock indicates automatically the week, day, month, and
date, also leap-year, and has no other motive power than the clock with which it is
connected. The motion is derived from the hour wheel of an ordinary clock,
which drives another or extra wheel that in twenty four hours makes a complete
revolution, and by a peg on it raises a lever connected to the calendar works by a
wire or cord; in this manner the works of the calendar movement are put in
motion once in twenty four hours and move the date hand or date dial one day
further round; or the lever may be raised by an eccentric. The works may be of
any desired size and are so constructed that the date may be shewn in two ways,
viz., either with three concentric dials, on which are the names and numbers; these
dials turn from left to right and display always one date, day of the week, and the
month, each through a suitable aperture in a painted glass in front of the works;
or with three hands of different lengths corresponding with the radii of the three
circles on a common dial. The outer circle has the dates 1 to 31, the middle one
the names of the month, and the inner one the days of the week. The hands
likewise move from left to right. The size of the dials is as desired.
•
The works are constructed as follows:-A plate of brass or iron having a spindle
or stud working in a bush fastened to the plate. This stud is fixed by a cross pin

page_text: at the back of the plate, while it is held and works in a bracket in front. On the
said spindle is fastened a wheel for indicating the seven days of the week; this
wheel has seven notches. A disc having the names of the seven days is screwed on
to the said spindle or stud and is moved daily with the aforesaid notched wheel.
In front of the notched wheel there is a brass sleeve, running on a stud and carrying
two discs rivetted on the month disc and the month wheel with twelve teeth.
The former is notched irregularly at the edge corresponding to the varying number
of days in the different months. There is a peg at its outermost point which comes
only in action in February; the other notches, nearer the centre, are for months
of thirty days, and the lowest for those with thirty one days; this will be described
more fully farther on. The aforesaid month disc sets itself on the first day of each
month and turns with the month wheel, with both of which also turns a dial which
is screwed on to the aforesaid sleeve and carrys the names of the months. On the
said sleeve fits another sleeve having four discs fastened thereon; firstly, a disc
having an oblong notch in the edge for the purpose of letting a hook gear once a
month with the month wheel and push it after the said disc has made a full turn
with two other wheels; secondly, one of these two latter wheels has thirty one
teeth and is pushed on a tooth every day by means of a hook. The pitch of the
teeth in this wheel is exactly the same as that of the aforesaid disc, and when both
these move one tooth the wheel with 31 teeth moves and the disc of its cir-
cumference. Thirdly, a date dial is screwed on in front and carries the numerals
1 to 31, and is moved daily one forward, but when the month has only 30, 29, or
28 days the wheel with 31 teeth and dial will be moved past the teeth and
numerals in question at once, so that the date dial will shew the first of the next
month instead of the 29th, 30th, or 31st of the preceeding one. This is done,
fourthly, by the other of the two wheels last mentioned, having only one notch and
a double wire which moves in a bush fixed horizontally to a bracket, one arm of
which is bent to the left almost parallel to the periphery of the said wheel and the
other arm goes towards the month disc and is pressed against it by a spring, made
preferably of brass. By the turning of the month disc the position of the double
wire is also altered, which will be described farther on. The revolutions of the
aforesaid notched wheel, month wheel, and the wheel having thirty one teeth are
regulated by pawl springs; the brass heads or teeth of same are rivetted on and
serve to prevent arbitrary motion of the said wheels. All three pawl springs have
a common fulcrum pin. In order that only one of the teeth of the thirty one toothed
wheel may gear at a time with the aforesaid pushing hook and no tooth be passed
over, and that the other said pushing hook may not always gear into the month
wheel by the notch in the aforesaid disc (when within reach) there are two guard
pegs screwed to a stud, one of which follows the periphery of the wheel having
thirty one teeth in parallel direction and the other follows similarly the month
wheel, by which action and by the position of the aforesaid disk with the oblong
notch a pawl can only fall in its notch and turn the month wheel one tooth when a
ratchet hook turns it the last tooth (the last day of the month), so that the next
day is the first of the next month. Three pushing pawls are arranged side by side
on a pin passing through a lever which has its fulcrum on the stud screwed into
the plate, and is held by a nut. When the lever is raised by a hook formed wire
to which is attached the aforesaid releasing wire or cord, which happens every
twenty four hours by the working of the time keeper, all four pushing pawls rise
therewith and incline by their shape and weight against their wheels, take into the
notches in question, if not occasionally prevented by special appliances, and drag
the wheels round one tooth, while the said lever has to pass the whole way from
the two resting and arresting pegs rivetted to the plate. Now the three aforesaid
pawl springs fall into the next following notches in the wheels and then the said
lever falls by its own weight to the resting peg. The pushing hooks may also be
provided with springs for pressing the same against the wheels in case the works
are not hung straight. The distance of the lever from the resting peg to the arresting

page_text: peg equals the distance of four teeth of the wheel having thirty one teeth. If there-
fore the pawl could gear each time when the notch in the other wheel comes within
reach, then the wheel with thirty one teeth would also be pushed on four teeth
each time, and the aforesaid dial would shew only twenty eight days each month,
as on each twenty eighth day the notch in the other wheel and the aforesaid pawl
would stand against one another, so that the latter would push the former on four
teeth if the arm bent to the left by its position did not interfere. Before entering
further upon the office of the aforesaid double wire, I will describe another disc at
the side of the month disc. This has eight equidistant notches in its periphery,
behind the 1st, 2nd, 3rd, 5th, 6th and 7th notch a small stud is rivetted in vertically.
When the month disc moving with the month wheel after eleven months time has
turned so far that the outermost point of the month disc comes quite close to the
other disc (that is in February) then the aforesaid peg rivetted on in this place
catches into a notch in the other disc and moves it so far that it can, after the next
whole turn of the month disc, catch into the next notch in the other disc. The
double wire is connected therewith in the following manner:-When its one arm
rests on one of the lowest points of the month disc then the opposite arm stands as
far out to the left as possible, and allows the aforesaid pushing pawl, which with
its horizontal peg rides on the double wire sufficiently to gear into the notch of the
other wheel when the latter has already almost passed the pawl, and can only be
turned one tooth, which then is already done by a pawl against the wheel having
thirty one teeth. Thus each tooth of this latter wheel is taken hold of separately,
and the aforesaid dial shews all thirty one numerals successively, that is, the month
has thirty one days. The month wheel is now moved a tooth onwards, and one
arm of the double wire (if now a month of thirty days follows) [comes to rest on a
higher part of the month disc, and thus further to the right. Thus the other arm
of the double wire will also move to the right and give the aforesaid hook more
play, so that in this instance the hook can catch a little sooner and move the wheel
two teeth further. The wheel with 31 teeth and the aforesaid disc make a
proportionate motion, and the latter only shews 30 days because two teeth were
moved at a time. The disc moves a turn, as described, till the peg comes against
the other disc, takes into one of its notches and moves it further. One arm of the
double wire will thereby not only glide over the extreme point of the month disc,
but will be pushed still more to the right by a peg entering between it and the
aforesaid peg, so that the other arm of the double wire following the same motion to
the right recedes so far from the pawl that the latter is released and can take hold
of the notch in the wheel when opposite it. The pawl now pushes this wheel, and
also the wheel with 31 teeth and the aforesaid dial, four numerals further on, and
upon the number 28 follows in this instance the number 1; the same is repeated
three times, as often as the peg touches the disc. In order that in the fourth
(or leap year) the 29th of February may be indicated, the fourth and eight notches
of the disc have no pegs whereby the arm of the double wire could be pushed back
so far as in the other three years; but the latter rather rests on the extreme
point of the month disc, and the other arm of the double wire permits the fall to
push only three teeth, so that the dial in this instance shews the first day of the
new month after the 29th day.
It is necessary that the calendar movement is so connected with the clock
movement that the lever is lifted each time the whole distance from the resting
peg to the arresting peg; when the clock and the calendar works stop, and are
not put in motion for a month, week, or day, the calendar works are so set
that the aforesaid three dials are turned so far to the left as to shew correctly..
So, also, when the works have a common dial with three hands the latter are
similarly turned to the right position. When the works are taken to pieces,
and it is desired to put them together again, it must be observed only to
keep the order of the pegs on the disc accurate according to the years. If, for
instance, the February next but one falls in leap year then the disc must be so set
that the notch to be caught next by the aforesaid peg has likewise a peg, and the next

page_text: notch none, and so on. If the disc should be turned the small wire must again rest
in a small notch of the former, as otherwise the peg cannot catch into the disc, and
the whole works would stop. The friction is so small that oiling is not needed,
and had even better be omitted, as if the oil should get thick it would interfere
with the working. As the works differ in construction from existing calendar works
in that they have no special impelling spring rollers or band for names and
numerals, and the influence on the driving clock work is constantly the same, an
unequal wear of the parts is not probable, and it may thus last for an unlimited
time.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jacob Merzbach in the Great Seal Patent Office on the 26th January
1880.
JACOB MERZBACH, of Holborn Viaduct, in the City of London. "AN IMPROVED
CALENDAR CLOCK MOVEMENT." (A communication from abroad by Erhardt
Junghans and Arthur Junghans, both of Schramberg, Germany.)
The improved calendar clock indicates automatically the week, day, month, and
date, and also leap year, and has no other motive power than the clock with which
it is connected. The motion is derived from the hour wheel of an ordinary clock,
which drives another or extra wheel that in 24 hours makes one complete revolu-
tion, and by a peg on it raises a lever connected to the calendar works by a wire
or cord. In this manner the works of the calendar movement are put in motion
once in 24 hours, and moves the date band or date dial one day further round, or
the lever may be raised by an excentric; and in order that this Invention may be
better understood I will now proceed to describe the same with reference to the
accompanying Drawing. Figure 1 is a front view, Figure 2 side view of the
calendar works; and Figures 3 to 8 are details. The works may be of any desired
size, and are so constructed that the date may be shewn in two ways, viz., as shewn
in Figure 8, with three concentric dials, on which are the names and numbers;
these dials turn from left to right, and display always only one date, day of the
week, and month each through a suitable aperture in a painted glass on front of
the works; or with three hands of different lengths corresponding with the radii
of the three circles on a common dial. The outer circle has the dates 1 to 31, the
middle one the names of the months, and the inner one the days of the week. The
hands likewise move from left to right. The order of the wheels in the movement
is in this case the reverse of that shewn in the Figure; hence D would be front
wheel, and M hinder wheel. The size of dials is as desired. The works are con-
structed as follows:-
A is the plate of brass or iron by preference; B is a spindle or stud working in
the bush a fastened to the plate; the stud B is fixed by a cross pin at the back of

page_text: the plate, while it is held and works in the bracket C in front. On B there is (for
indicating the 7 days of the week) a wheel D with 7 notches for that purpose; the
dial D' containing the names of the 7 days is screwed on to B, and is moved daily
with the wheel D. In front of the wheel D there is a brass sleeve E, running on
the stud B, and carrying two discs rivetted on, viz., the month disc F, and the
month wheel G, with 12 teeth; the former is notched irregularly at the edge, corre-
sponding to the varying number of days in the months. The peg F1, Figure 6, at
its outermost point comes only in action in February; the other notches nearer
the centre are for months with 30 days, and lowest for those with 31 days; this
will be described more particularly further on. The disc F sets itself on the first day
of each month, and turns with the wheel G, and with both of them the dial H also
turns, which is screwed on to the same sleeve E, and carries the names of the
months. On the sleeve E fits a sleeve J, having four discs fastened on it, viz.,
firstly, the disc K, Figure 5, having an oblong notch on the edge for the purpose of
letting the hook. Y' gear once a month with the month wheel G, and push it after
that K has made a full turn with the wheels L and M; secondly, the wheel L with
31 teeth (Figure 4) is every day pushed on a tooth by the hook X¹; the pitch of
the teeth in this wheel is exactly the same as that of the wheel K, and when both
move one tooth L moves / and K 1/12th of its circumference.
Thirdly. The date dial N is screwed on in front on to J, and carries the numerals
1 to 31, and is moved daily one forward, but when the month has only 30, 29, or
28 days, L and M will be moved past the teeth and numerals in question at once,
so that the date dial will show the 1st of the next month instead of the 29th, 30th,
or 31st of the preceding one. This is done, fourthly, by the wheel M having only
one notch, and a double wire V, which moves in a bush fixed horizontally to the
bracket C, and one arm VI of which is bent to the left almost parallel to the
periphery of the wheel M; the other wire V2 goes towards the disc F, and is pressed
against it by a spring V³. By turning the disc F the position of the double wire
is also altered, which is described further on. The revolutions of the three wheels
D, G, and L, are regulated by pawl springs P, Q, R, Figure 1. The brass heads or teeth
of same are rivetted on and serve to prevent arbitrary motion of said wheel. All
three pawl springs have a common fulcrum pin 0 (the pawl springs are not shewn
in Figure 2). In order that on the wheel L only one tooth gears at a time with
the pushing hook X¹, and no tooth be passed over, and that the pushing hook Y'
may not always gear in the wheel G by the notch in the disc K (when within
reach) there are two guard pegs S and T screwed to the stud U. One of them S
follows the periphery of the wheel L in parallel direction, but the other one T
follows similarly the wheel G, whereby and by the position of the disc K the
pawl Y can only fall in its notch and turn G one tooth, when W or X' turns it the
last tooth (the last day in the month), so that the next day is the first of the next
month. The pushing-pawls W, X', Y', and Z' are arranged side by side on a pin
passing through the lever X, which has its fulcrum on the stud Y, and screwed into
the plate A, and is held by a nut. When the lever X is raised (by the hook formed
wire Z, to which is attached the aforesaid releasing wire or cord, which happens
every 24 hours, by the working of the time keeper) all four pushing pawls rise
therewith, incline by their shape and weight against their wheels, take into the
notches in question, if not occasionally prevented by special appliances, and drag
the wheels round one tooth, while X has to pass the whole way from q to p, the
two resting and arresting pegs rivetted to the plate A. Now the pawl springs
P, Q, R, fall into the next following notches in the wheels, and then X by its own
weight falls back to the resting peg q. The pushing hooks may also be provided
with springs for pressing same against the wheels in case the works are not
perpendicular. The travelling of X from q to p equals the distance of four teeth
of the wheel L. If therefore the pawl W could gear each time when the notch in
the wheel M comes within reach, then the wheel L would also be pushed each time
on four teeth, and the dial N would shew only 28 days each month, as on each

page_text: 28th day the notch in the wheel M and the pawl W' would stand against one
another, that the latter would push the former on 4 teeth if the arm V' by its
position did not interfere. Before entering further upon the office of the double
wire V I will describe the disc W at the side of the month disc F. This has
8 equidistant notches in its periphery; behind the 1st, 2nd, 3rd, 5th, 6th, and 7th
notches a small stud is rivetted in vertically. When the disc F moving with the
month wheel G after 11 months time has turned so far that the outermost point
of F comes quite close to the disc W (that is in February), then the peg F¹ rivetted
on in this place catches into a notch in the disc W, and moves it so far that it can
after the next whole turn of the disc F catch into the next notch in W. The
double wire V is connected herewith in the following manner :-When its arm V³
rests on one of the lowest points of the disc F, then the opposite arm V¹ stands so
far out to the left as possible, and allows the pushing pawl W', which with its
horizontal peg rides on V₁, only just sufficient to gear into the notch of M, when
the latter already has almost passed the pawl, and only can be turned one tooth
which is already done by the pawl Y against the wheel L. Thus each tooth of
the wheel L is taken hold. of separately, and the dial N shows all 31 numerals
successively, that is, the month has 31 days. The month wheel G is now moved a
tooth onwards, and V2 (if now a month of 30 days follows) comes to rest at a
higher part of the disc F, and thus further to the right. Thus V will also move to
the right and give the hook w' more play, so that in this instance the book can
catch a little sooner, and moves M two teeth further, L and N make a proportionate
motion, and the latter only shews 30 days, because two teeth were moved at a
time. The disc F moves a turn, as described, till the peg F' comes against the
disc W, takes into one of its notches and moves it further. The wire V° will
thereby not only glide over the extreme point of F, but will be pushed still more to
the right by a peg entering between it and F, so that V1 following the same motion
to the right recedes so far from the pawl W₁ that the latter is released, and can
take hold of the notch in the wheel M when opposite it. The pawl W' now
pushes M and also L and N four teeth (four numeral) further, and upon the
number 28 follows in this instance the number 1; the same repeated three times
as often as the peg F¹ touches the disc W. In order that in the fourth (or leap
year) the 29th of February may be indicated the 4th and 8th notches of the disc W
(Figure 6) have no pegs, whereby the wire V2 could be pushed back as far as in
the other 3 years, but the latter rests on the extreme point of F, and V₁ permits
the pawl w to push only 3 teeth, so that the dial N° in this instance shews the
first day of the new month after the 29th day. It is necessary that the calendar
movement be so connected with the clock movement that when the lever X is
lifted it moves the whole distance from q to P. When the clock and the calendar
works stop and are not put in motion for a month, week, or day, the calendar
works are so set that the dials D', H, or N are turned so far to the left as to show
correctly. So also when the works have a common dial with three hands the latter
are similarly turned to the right position. When the works are taken to pieces,
and it is desired to put them together again, it must be observed to keep the order
of the pegs on the disc W correct according to the years. If, for instance, February
next but one falls in a leap year, then the disc W must be so set that the notch
next to be caught by F1 has a peg, and the next one none, and so on.
If the
dise W should be turned the small wire w³ must again rest in a small notch of the
former, as otherwise the peg F¹ cannot catch into the disc W, and the whole works
would stop. The friction is so small that oiling is not needed, and had even better
be omitted, as if the oil should get thick it would interfere with the working. As
the works differ in construction from existing calendar works, having no special
impelling spring nor rollers or bands for names and numerals, and the influence on
the driving clock work is constantly the same, an unequal wear of the parts is not
probable, and it may thus last for an unlimited time.
Having thus described and ascertained the nature and object of this Invention

page_text: and the manner of carrying the same into effect, I would remark in conclusion that
what I claim is,-
First. The calendar clock movement, having no special weight or spring, but
working by the power of the clock movement to which it is connected, substantially
as set forth.
Second. The construction of calendar movement, substantially as set forth.
In witness whereof, I, the said Jacob Merzbach, have hereunto set my hand
and seal, this Fifth day of January, in the year of our Lord One thousand
eight hundred and eighty.
JACOB MERZBACH. (L.S.)