IMPROVING CLOCK ESCAPEMENTS
Year: 1853

page_text: LETTERS PATENT to Charles Cummins, of 148, Leadenhall Street,
in the City of London, Chronometer Maker, for the Invention of
"IMPROVING CLOCK ESCAPEMENTS."
Scaled the 16th January 1854, and dated the 28th July 1853.
PROVISIONAL SPECIFICATION left by the said Charles Cummins
at the Office of the Commissioners of Patents, with his Petition,
on the 28th July 1853.
J, CHARLES CUMMINS, of 148, Leadenhall Street, in the City of
London, do hereby declare the nature of the said Invention for
"IMPROVING CLOCK ESCAPEMENTS" to be as follows:-
Au entire roller working in bearings fitted to the spindle of the
roller acted upon by a wheel with a double row of pins. Or entire
rollers working on pivots acted upon by a wheel with a double row of
teeth; one roller above, the other below, the centre of the wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by, the said Charles Cummins in the Great Seal Patent
Office, on the 27th January 1854.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of July, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Charles Cummins, Her special
licence that I, the said Charles Cummins, my executors, administrators,
and assigns, or such others as I, the said Charles Cummins, my execu-
tors, 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 Invention for "IMPROVING CLOCK
ESCAPEZIENTS," upon the condition (amongst others) that I, the said
Charles Cummins, by an instrument in writing under my band and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Charles Cummins 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 (that is to say):
My Invention consists of peculiar clock escapements, one of which
consists of a wheel with a plain rim upon the plane of this rim there
are two circles formed of pins, cach circle containing an equal number,
the pins being equivalent to the quantity of teeth required in ordinary
clock escapements.
In constructing such an escapement, the distance from the centre of
the wheel being determined upon for the interior circle of pins, divide
such circle into the requisite number of holes, then describe half circles,
as shewn at Figure 5, from the pin holes in the inner circle that will
bisect each other, and where these half circles bisect each other will
be the distance for the exterior circle of pins. The exterior pins should
be twice the size of those in the interior circle; the size of the pins
must be allowed for in making up the escapement. On an arm
attached to the axis of the crutch is formed a slot hole, into which is

page_text: fitted the piece that carries the roller; the slot is for the purpose of
altering the position of the roller to be adjusted, and obtain an equal
amount of escapement action for the right and left swing of the
pendulum.
The distance of the crutch pivot holes from the escapement wheel
pivot holes is from five eighths to an entire diameter of the escape-
ment wheel; the latter distance should not be exceeded.
The diameter of the roller is equal to the space between the pins of
the interior circle. The space between the circles formed by the pins
on the escapement wheel being less than the diameter of the roller
will give to the roller by the rotatory motion of the wheel a revolving
alternate motion, also an oscillatory motion; the latter sustains the
vibration of the pendulum.
The other escapement, and which I call the double roller escape-
ment, has a wheel with one circle of pins or solid projections. The
arm bearing the pieces into which the pivots of the rollers work
is attached, as in the single roller escapement, to the axis of the
crutch; the distance from the escapement wheel pivots to the crutch
pivots is likewise the same. The diameter of the rollers is guided
by the space between the pins, free passage being required for them
and no more; the rollers should be alike in respect to shape and size.
The upper roller is acted upon from the interior of the wheel, the lower
roller from the exterior; the distance between the rollers should be
within one fourth part of the circumference of the wheel, as the effective
angle of the escapement is diminished by exceeding that limit; the
exact position or adjustment is obtained by the aid of the slot holes in
the arm. Suppose the upper roller for the time being to be acted on
by the rotatory motion of the escapement wheel, this action upon the
upper roller ceases by the pin leaving it; the lower roller will be moved
in towards the centre of the wheel, and into the space between two of
the pins; the wheel will then be arrested by a pin coming in contac
with the lower roller; this roller will then begin to revolve; the pendulum
having completed an ascending arc during its return will receive from
the lower roller an impulse; the upper roller will be moved out into the
space between two of the pins, and a pin will again arrest the wheel;
he pendulum will perform the opposite ascending arc; then upon its

page_text: return it will receive from the upper roller an impulse, and thus com-
plete the action of the escapement.
Brass pins or projections and steel roller or rollers, or steel pins or
projections and brass roller or rollers, are applicable and preferred for
these escapements. Friction being considerably reduced in these
escapements, oil is not required where it is indispensable in ordinary
clock escapements.
DESCRIPTION OF THE DRAWING.
Figures 1, and 2, represent the single roller escapement under action
for the right and left swing of the pendulum. A, the escapement
wheel; B, the arm; C, the adjusting piece which carries the roller D.
Figures 3, and 4, represent the double roller escapement in like
positions. A, the escapement wheel; B, the arm; C, C, the adjusting
pieces which carry the rollers; D, D, the rollers. Figure 5, shows the
method or plan for finding the distance of the exterior circle for the
single roller escapement from the centre of the wheel. Figure 6, side
view of the arm B, for the single escapement. Figure 7, shows a side
view of the arm B, for the double roller escapement.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I do
'not confine myself to the precise details shown and described. But I
claim the combinations of escapements herein described, whereby an
entire roller acts with an escapement wheel, or entire rollers act with a
suitable escapenient wheel.
In witness whereof, I, the said Charles Cummins, have here-
unto set my hand and scal, this Twenty-fourth day of January,
in the year of our Lord One thousand eight hundred and fifty-
Witness,-
S. CARPMAEL..
CHARLES CUMMINS. (L.S.)