IMPROVEMENTS IN CALENDAR MOVEMENTS FOR CLOCKS
Year: 1866

page_text: LETTERS PATENT to James Theodore Griffin, of Fleet Street, in the City
of London, Gentleman, for the Invention of "IMPROVEMENTS IN CALENDAR
MOVEMENTS FOR CLOCKS."-A communication from abroad by Henry
Horton of Ithaca in the United States of America
Sealed the 28th June 1867, and dated the 31st December 1866.
PROVISIONAL SPECIFICATION left by the said James Theodore Griffin
at the Office of the Commissioners of Patents, with his Petition, on the
31st December 1866.
1, JAMES THEODORE GRIFFIN, of Fleet Street, in the City of London,
Gentleman, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN CALENDAR MOVEMENTS FOR CLOCKS," to be as follows:-
The objects of this Invention are to construct calendar clocks which will
show the day of the month, the day of the week, and the month, making the
changes instantaneously at midnight, and to hold the several wheels at all
times so that no accidental turning of them can occur.
These improvements consists, first, in the employment of a 4, 8, 12, or more
year wheel containing virtually the uses and position of the wheel hereafter
described, moved by a pin or equivalent, and controlled by a bent wire or
equivalent, and having surfaces as hereafter described; also in the employment
of this year wheel when made of 8 slots, six plain and 2 irregular surfaces, as
described, or other correlative number of parts, periphery slots, and surfaces

page_text: when made, substantially as described; also in the employment of a February
cam constructed on the year cam disc for leap year, as described, when used
in combination with the year wheel before referred to, or with other device or
mechanism in place of the wheel.
Secondly, in the employment, as hereafter described, of a paul in immediate
contact or otherwise with a stop lever which takes into the teeth of the 31-
days' wheel for the purpose of rendering the action of this paul more sure.
Thirdly, in the employment of a lever cam, as hereafter described, on the
31-days' wheel for the purpose of passing the stop lever over the 31st tooth
of the month wheel for months of 30 days, and over the 30th and 31st teeth
for February in leap year, and over the 29th, 30th, and 31st teeth when
February has 28 days or otherwise, using the lever cam for the same
purpose.
Fourthly, in the employment, as hereafter described, of a bent wire for the
purpose of changing the length of the months, and of February in leap year,
in a 31-toothed month wheel, and also of this wire acting in combination with
the lever cam before referred to, and with cams on a year cam disc, and
projections on an eight or other year wheel.
Fifthly, in operating the calender by the slotting or looping of a rod about
the main cam, as hereafter described for retaining the rod in its place, and by
the combination of the main cam and rod producing the changes of the calendar
instantaneously at midnight.
Sixthly, in attaching a tumbler hereafter described to a weight lever in
such manner as to receive the action of the main cam 'by the bent rod, and by
a cam surface of the tumbler carry a stop lever over the teeth of the 31-days'
wheel; also in the employment of a tumbler for raising a stop lever over one
tooth of the 31-days' wheel, and also of one tooth of the year wheel, and of
the days of the week wheel while in the act of making their changes; also in
raising or tilting the stop lever of the 31-days' wheel or the correlative lever of
the week and year wheels over the teeth acted on by the same when produced
by the fall in changing of their respective rods or levers, all as hereafter
described.
Lastly, in the combinations or arrangements of parts of calendar movements
for clocks, as hereafter described.
The improvements will be fully understood by the following description of a
calendar movement to which they are applied.
The ordinary movement of the clock to which the calendar movement is
attached is provided with a wheel, which through the intermediation of a
worm shaft or otherwise imparts motion to a wheel of the calendar movement,

page_text: so that the latter wheel revolves once in 24 hours; this wheel is mounted
on a fixed pin, and carries a main cam, which rotates with it once in
24 hours. The cam is embraced by a rod bent into the form of a vertical
slot or loop, and the rod is kept in a vertical position by one end being carried
from the bottom of the loop up through eyes on the cam pin. The other end
of the rod is carried from the bottom of the loop to a plate, to which the upper
ends of two connecting rods are attached; the lower ends of these rods are in
connection, as hereafter described, one with the 31-days' wheel, the other with
the week wheel. The end of the first rod is attached to one end of a tumbler
pivoted at about its middle to a weight lever mounted loosely on the shaft of
the 31-days' wheel; the weight lever has a projection on its back face near
its upper end, under which the tumbler in the upward movement of the rod
takes, so as to lift this end of the weight lever; the weight lever at this end
also carries a paul, which engages in one tooth of the 31-days' wheel, and
thereby moves the wheel the distance of one tooth every time it is carried
down by the fall of the weight lever; this fall takes place with the descent of
the connecting rod before named when the main cam after raising the loop of
the bent rod to its highest position suddenly at midnight lets it fall. The
paul has a projection at its upper part, which bears with sufficient pressure
against a stop lever to insure the paul taking into its tooth; this stop lever is
pivoted at one end to the frame or to a pillar, while its other end has a
projection which engages into the teeth of the 31-days' wheel, and prevents
the wheel moving, the lever being kept down by a spring; but when the loop.
of the bent rod falls with the connecting rod, and that end of the tumbler to
which this rod is connected, the other end of the tumbler which has a cam.
surface strikes up and disengages the stop lever from the 31-days' wheel, and
allows the wheel to be turned the distance of one tooth by the paul and weight
lever, as before described. The lower end of the second connecting rod before
mentioned is connected (in a similar way to the first-named. rod) to the week
wheel, which, however, has 14 teeth or other number corresponding to the
number of days in two or other number of weeks; this week wheel is attached
to the end of a drum marked with the names of the days of the week, one or
other of which is always visible through an aperture in the dial plate; in this
case, however, the stop lever may be kept down by its own weight instead of
by a spring. The shaft of the 31-days' wheel projects through the dial plate
and carries a pointer; on this shaft a cam is mounted of corresponding shape
.to the main cam, and having bearing upon it a leg depending from a horizontal
bar pivoted at one end to the frame; the opposite end of the bar is free to
move up and down on a guide; near this end it has connected to it a short

page_text: rod connected to a tumbler on one end of a weight bar carrying a paul,
which takes into the teeth of a twelve-toothed year wheel on the end of a drum
marked with the names of the months, one or other of which is always visible
through a hole in the dial plate; these parts act in a similar manner to those
on the 31-days' wheel, as before described, the bar falling at the end of every
month, and being again gradually raised by the cam on the shaft of the
31-days' wheel. On the other end of the drum is a year cam disc, having
projections and depressions on its periphery arranged according to the number
of days in the several months; the depressions correspond with months of
31 days, and the projections with months of 30 days, except one projection
which is larger or wider for February. The outer face of this disc carries a
pin, which takes into a slot in an eight-year wheel having eight slots and six
plain and 2 irregular surfaces between the slots; the two irregular surfaces
are for leap years, and the others for ordinary years. This eight-year wheel
is carried by the frame or by a pillar. As the drum revolves the pin on the
cam disc at the end of every February enters another of the slots and moves
this wheel an eighth of a revolution. A bent spring wire carried on the frame
takes into one or other of the slots, and prevents the wheel rotating, except
when released by being acted upon by the February projection on the disc, when
the eight-year wheel has to make its eighth of a revolution, as just stated.
Upon the front face of the 31-days' wheel a lever cam is pivoted having three
projections of varying length; this cam moves round with the wheel, and the
projections at the end of each month have come round to the top of the wheel.
The bent wire before mentioned when acted upon by the projections of the
year disc is pushed so that its end which is bent up comes against the face of
one of the projections, so that the lever cam as it moves round rises over the
end of the wire for the extent of this projection, and at the same time raises
the stop lever by means of a pin depending therefrom. When the portion of
the year cam disc corresponding to a month of 31 days, that is to say, a
depression of the cam, bears against the bent wire the end of the latter is not
caused to bear against any of the projections of the lever cam; but when a
projection corresponding to a month of 30 days bears against the bent wire
its end takes against the smallest projection of the lever cam, which is thereby
raised as it moves round together with the stop lever a sufficient time for the
31-days' wheel to move the distance of two teeth. In like manner at the end
of February of 28 days the end of the bent wire is caused by the February
cam of the year disc to take against the largest projection of the lever cam,
whereby this cam and the stop paul are raised a sufficient time for the 31-days'
wheel to move the distance of 4 teeth.

page_text: For leap year the following arrangement is adopted, one of the irregular
surfaces of the eight-year wheel coming into operation; this irregular surface
is of the same extent in a circular direction as each plain surface, but it has
an indentation, and the year disc bas a corresponding indentation of less depth
in the February cam. In ordinary years when the February cam bas pushed
the bent wire so as to take against the third or largest projection on the lever
cam the indentation of the February cam is not entered by the bent wire,
because the plain surface of the 8-year wheel keeps the wire out against the
third projection; in leap year, however, the indented surface of the 8-year
wheel does not keep the wire out against this third projection, but allows the
wire to withdraw so as to enter the indentation of the February cam; the end
of the wire thereby takes against the middle projection of the lever cam, and
this cam and the stop lever are raised a sufficient time for the 31-days' wheel
to move the distance of three teeth. The bent spring wire works in a plate
slotted horizontally to keep it in position.
Instead of an eight-year wheel a 4, or 12, or other year wheel having
a correlative number of parts may be employed, the slots corresponding to the
number of years, and every fourth surface between the slots being indented
for leap year.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Theodore Griffin in the Great Seal Patent Office on the
29th June 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THEODORE GRIFFIN, of Fleet Street, in the City of London, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of December, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Theodore Griffin, Her special licence that I, the said
James Theodore Griffin, my executors, administrators, and assigns, or such
others as I, the said James Theodore Griffin, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an

page_text: Invention for "IMPROVEMENTS IN CALENDAR MOVEMENTS FOR CLOCKS," (com-
municated to me from abroad by Henry Horton, of Ithaca, in the United
States of America,) upon the condition (amongst others) that I, the said
James Theodore Griffin, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Theodore Griffin, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say:-
The objects of this Invention are to construct calendar clocks which will
show the day of the month, the day of the week, and the month, making the
changes instantaneously at midnight, and to hold the several wheels at all
times so that no accidental turning of them can occur.
These improvements consist, first, in the employment of a four, eight, twelve,
or more year wheel, containing virtually the uses and position of the wheel
herein-after described, moved by a pin or equivalent, and controlled by a bent
wire or equivalent, and having surfaces as hereafter described; also in the
employment of this year wheel when made of eight slots, six plain and two
irregular surfaces, as described, or other correlative number of parts, periphery,
slots, and surfaces, when made substantially as described; also in the employ-
ment of a February cam constructed on the year cam disc for leap year, as
described, when used in combination with the year wheel before referred to,
or with other device or mechanism in place of the wheel.
Secondly, in the employment, as herein-after described, of a paul in
immediate contact or otherwise with a stop lever which takes into the teeth of
the 31-days' wheel for the purpose of rendering the action of the paul more sure.
Thirdly, in the employment of a lever cam, as hereafter described, on the 31-
days' wheel for the purpose of passing the stop lever over the 31st tooth of the
month wheel for months of 30 days, and over the 30th and 31st teeth for
February in leap year, and over the 29th, 30th, and 31st teeth when February
has 28 days, or otherwise using the lever cam for the same purpose.
Fourthly, in the employment as hereafter described of a bent wire for the
purpose of changing the length of the months and of February in leap year in
a 31-toothed month wheel, and also of this wire acting, in combination with

page_text: the lever cam before referred to, and with cams on a year cam disc, and
projections on an eight or other year wheel.
Fifthly, in operating the calendar by the slotting or looping of a rod about
the main cam, as hereafter described, for retaining the rod in its place, and
by the combination of the main cam and rod producing the changes of the
calendar instantaneously at midnight.
Sixthly, in attaching a tumbler hereafter described to a weight lever in such
manner as to receive the action of the main cam by the bent rod and by a
cam surface of the tumbler carry a stop lever over the teeth of the 31-days'
wheel ; also in the employment of a tumbler for raising a stop lever over one
tooth of the 31-days' wheel, and also one tooth of the year wheel, and of the
days of the week wheel while in the act of making their changes; also in
raising or tilting the stop lever of the 31-days' wheel, or the correlative lever of
the week and year wheels over the teeth acted on by the same when
produced by the fall in changing of their respective rods or levers, all as
bereafter described.
Lastly, in the combinations or arrangements of parts of calendar move-
ments for clocks, as hereafter described.
The improvements will be fully understood on reference to the accom-
panying Drawings, of which Figure 1 is a view of a calendar face; Figure 2,
a back view of the mechanism; Figure 3, an end elevation with the casing in
section, and Figure 4 a plan of the same, and by the following description of
a calendar movement to which they are applied.
The ordinary movement of the clock to which the calendar movement is
attached is provided with a wheel which through the intermediation of a worm
shaft or otherwise imparts motion to a wheel of the calendar movement so that
the latter wheel revolves once in twenty-four hours; this wheel is mounted on a
fixed pin a, and carries a main cam 6 which rotates with it once in twenty-four
hours. The cam is embraced by a rod c bent into the form of a vertical slot or
loop, and the rod is kept in a vertical position by one end being carried from the
bottom of the loop up through eyes on the cam pin, as shown; the other end
of the rod is carried from the bottom of the loop to a plate d, to which the
upper ends of two connecting rods e, f, are attached; the lower ends of these
rods e, f, are in connection, as hereafter described; one e with the 31-days'
wheel, the other f with the week wheel. The end of the first rod is attached
to one end of a tumbler g, pivoted at about its middle to a weight lever h
(shown detached in Figure 8) mounted loosely on the shaft of the 31-days'
wheel i; the weight lever h has a projection ; on its back face near its upper
end, under which the tumbler g in the upward movement of the rod e takes,

page_text: so as to lift this end of the weight lever h; the weight lever at this end also
carries a paul k, a detached view of which is seen in Figure 4ª, which engages
in one tooth of the 31-days' wheel, and thereby moves the wheel the distance
of one tooth every time it is carried down by the fall of the weight lever; this
fall takes place with the descent of the connecting rod e before named, when
the main cam 6 after raising the loop of the bent rod c to its highest position
suddenly at midnight lets it fall. The paul k has a projection at its upper
part, which bears with sufficient pressure against a stop lever m to insure the
paul taking into its tooth; this stop lever m is pivoted at one end to the
frame or to a pillar, as shown, while its other end has a projection n which
engages into the teeth of the 31-days' wheel, and prevents the wheel moving,
the lever m being kept down by a spring; but when the loop of the bent
rod falls with the connecting rod and that end of the tumbler g to which
this rod e is connected the other end of the tumbler which has a cam
surface strikes up and disengages the stop lever from the 31-days' wheel and
allows the wheel to be turned the distance of one tooth by the paul k and
weight lever m, as before described. The lower end of the second con-
necting rod f, before-mentioned, is connected in a similar way to the first-
named rod e to the week wheel o, which however has 14 teeth or
other number corresponding to the number of days in two or other number
of weeks; this week wheel is attached to the end of a drum marked
with the names of the days of the week, one or other of which is always
visible through an aperture in the dial plate, as seen in Figure 1; in this case,
however, its stop lever p may be kept down by its own weight instead of by
a spring. The shaft of the 31-days' wheel projects through the dial plate and
carries a pointer; on this shaft a cam is mounted of corresponding shape to
the main cam, as shown in Figure 5, and having bearing upon it a leg q
depending from a horizontal bar pivoted at one end to the frame. The
opposite end of the bar is free to move up and down a guide s; near this
end it has connected to it a short rod t connected to a tumbler on one end of a
weight lever u carrying a paul which takes into the teeth of a twelve-toothed
year wheel on the end of a drum marked with the names of the months, one
or other of which is always visible through a hole in the dial plate. These
parts act in a similar manner to those on the 31-days' wheel, as before
described, the bar r falling at the end of every month, and being then again
gradually raised by the cam 9 on the shaft of the 31-days' wheel. On the
other end of the drum is a year cam disc v, shewn in Figure 6, having pro-
jections and depressions on its periphery arranged according to the number of
days in the several months; the depressions correspond with months of

page_text: 31 days, and the projections with months of 30 days, except one projection,
which is larger or wider, for February. The outer face of this disc carries a
pin w, which takes into a slot in an eight-year wheel x, having eight slots
and six plain and two irregular surfaces between the slots, as shewn in
Figure 7, the two irregular surfaces are for leap years, and the others for
ordinary years; this eight-year wheel is carried by the frame or by a pillar.
As the drum revolves the pin on the cam disc at the end of every February
enters another of the slots and moves this wheel an eighth of a revolution. A
bent spring wire y carried on the frame takes into one or other of the slots
and prevents the wheel rotating, except when released by being acted on by
the February projection on the disc when the eight-year wheel has to make
its eighth of a revolution as just stated. Upon the front face of the 31-days'
wheel a lever cam is pivoted, having three projections of varying length;
this cam moves round with the wheel, and the projections at the end of each
month have come round to the top of the wheel. The bent wire before
mentioned when acted upon by the projections of the year disc is pushed so
that its end which is bent up comes against the face of one of the projections,
so that the lever cam as it moves round rises over the end of the wire for
the extent of this projection, and at the same time raises the stop lever m by
means of a pin a depending therefrom. When the portion of the year cam
disc corresponding to a month of 31 days, that is to say, a depression of the
cam bears against the bent wire the end of the latter is not caused to bear
against any of the projections of the lever cam; but when a projection
corresponding to a month of 30 days bears against the bent wire its end takes
against the smallest projection of the lever cam 2, which is thereby raised as
it moves round together with the stop lever m a sufficient time for the
31-days' wheel to move the distance of two teeth. In like manner at the
end of February of 28 days the end of the bent wire is caused by the February
cam of the year disc to take against the largest projection of the lever cam g,
whereby this cam and the stop paul m are raised a sufficient time for the
31-days' wheel to move the distance of 4 teeth.
For leap year the following arrangement is adopted, one of the irregular
surfaces of the eight-year wheel coming into operation; this irregular surface
is of the same extent in a circular direction as each plain surface, but it has
an indentation, and the year disc v has a corresponding indentation of less
depth in the February cam. In ordinary years when the February cam has
pushed the bent wire so as to take against the third or largest projection on the
lever cam the indentation of the February cam is not entered by the bent wire,
because the plain surface of the eight-year. wheel keeps the wire out against

page_text: the third projection; in leap year, however, the indented surface of the 8-year
wheel does not keep the wire out against this third projection, but allows
the wire to withdraw, so as to enter the indentation of the February cam, the
end of the wire thereby takes against the middle projection of the lever cam,
and this cam and the stop lever are raised a sufficient time for the 31-days'
wheel to move the distance of three teeth. The bent spring wire works in a
plate slotted horizontally to keep it in position. Instead of an eight-year
wheel a 4, or 12, or other year wheel having a correlative number of parts
may be employed, the slots corresponding to the number of years, and every
fourth surface between the slots being indented for leap year.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim as the "Improve-
ments in Calendar Movements for Clocks,-
First, the employment of a 4, 8, 12, or more year wheel, containing virtually
the uses and position of the wheel herein-before described moved by a pin or
equivalent, and controlled by a bent wire or equivalent, and having surfaces
as herein-before described.
Second, the employment of a year wheel when made with 8 slots, six plain
and two irregular surfaces, as herein-before described, or other correlative
number of parts, periphery slots, and surfaces when made substantially as
herein-before described.
Third, the employment of a February cam constructed on the year cam
disc for leap year, as herein-before described, when used in combination
with the year wheel, or with other device or mechanism in place of the
wheel.
Fourth, the employment, as herein-before described, of a paul in immediate
contact or otherwise with a stop lever which takes into the teeth of the
31-days' wheel for the purpose of rendering the action of the paul more
sure.
Fifth, the employment of a lever cam, as herein-before described, on the
31-days' wheel for the purpose of passing the stop lever over the 31st tooth
of the month wheel for months of 30 days, over the 30th and 31st teeth for
February in leap year, and over the 29th, 30th, and 31st teeth when February
has 28 days, or otherwise using the lever cam for the same purpose.
Sixth, the employment, as herein-before described, of a beut wire for the
purpose of changing the length of the months, and of February in leap year
in a 31-toothed month wheel, and also of this wire acting in combination
with the lever cam, herein-before described, and with cams on a year cam
disc, and projections on an eight or other year wheel.

page_text: Seventh, operating the calendar by the slotting or looping of a rod about
the main cam, as herein-before described, for retaining the rod in its place,
and by the combination of the main cam and rod producing the changes of
the calendar instantaneously at midnight, as herein-before described.
Eighth, attaching the tumbler, herein-before described, to a weight lever
in such manner as to receive the action of the main cam by the bent rod, and
by a cam surface of the tumbler carry a stop lever over the teeth of the.
31-days' wheel, as herein-before described.
Ninth, the employment, as herein-before described, of a tumbler for raising
a stop lever over one tooth of the 31-days' wheel, and also one tooth of the
year wheel, and of the days of the week wheel while in the act of making
their changes.
Tenth, raising or tilting the stop lever of the 31-days' wheel, or the correlative
lever of the week and year wheels over the teeth acted on by the same when
produced by the fall in changing of their respective rods or levers, as berein-
before described.
Eleventh, the combinations or arrangements of parts of calendar movements
for clocks, all substantially as herein-before described and represented in the
accompanying Drawings.
In witness whereof, I, the said James Theodore Griffin, have hereunto
set my hand and seal, the Twentieth day of June, One thousand eight
hundred and sixty-seven.
JAMES T. GRIFFIN. (L.s.)