Year: 1875

page_text: LETTERS PATENT to Alfred John Higham, of No. 13, Blackheath
Terrace, Blackheath, in the County of Kent, Gentleman, for the

page_text: these stops alternately certain parts of the escape wheel rest, one of
them acting on one side of the pendulum from above and the other on
the other side of the pendulum from below, and though the impulse
levers may be arranged one on each side of the pendulum as usual, in
several arrangements of escapements I arrange the escape wheel and
stops or parts on or off the said impulse levers, or on or off parts
connected therewith, so as to stop or lock the escape wheel always in
the same direction or nearly so.
The "Dennison" escapement above mentioned has two sets of teeth,
3 for lifting and 6 for stopping or locking, but the arrangement herein
described is adapted to an escape wheel with one cam or tooth or other
single or double number to the "pin wheel," or to that escapement
known as "Graham's dead beat," or to other escapements, and the
locking of the escape wheel may take place upon the fan as used with
most gravity escapements.
By arranging parts of the escape wheel and of the impulse levers a
subsiduary or secondary locking may be obtained, so as to make the
action of the clock or other timekeeper more regular and certain. This
modification may come into action only when the clock or other time-
keeper is about to "trip" or slip teeth, and thus prevent such
tripping," or it may be constant. This subsiduary and double locking
is also applicable to other escapements.
"
The stops or teeth against which the escape wheel locks are usually
applied on the impulse levers, but this is not necessary if arms or parts
are applied to carry such stops or teeth and enable the pendulum to
obtain the desired movement when required.
I do not limit myself to the use of two levers, as in certain cases more
or fewer may be conveniently used, and it is not necessary that there
should be two stops or teeth for the escape wheel to lock against, one
being sometimes sufficient, and this might be attached to the pendulum,
or on occasions more than two may be used.
This escapement with the adaptation of a balance wheel in place of
the pendulum, and an extra spring or springs in substitution of the
force of gravity is applicable to other timekeepers.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred John Higham in the Great Seal Patent
Office on the 17th February 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
JOHN HIGHAM, of No. 13, Blackheath Terrace, Blackheath, in the
County of Kent, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of August, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alfred John Higham, Her special license
that I, the said Alfred John Higham, my executors, administrators,
and assigns, or such others as I, the said Alfred John Higham, my
cxccutors, 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
"IMPROVEMENTS IN CLOCKS AND OTHER TIMEKEEPERS," upon the condition
(amongst others) that I, the said Alfred John Higham, 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 Alfred John Higham, 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 improvements in clocks and other timekeepers have reference to
the escapements thereof.
In the escapement commonly known as "Denison's double three-
legged gravity escapement" there are two impulse levers, one on each
side of the pendulum, each lever being provided with a stop, and upon

page_text: these stops alternately certain parts of the escape wheel rest, one of
them acting on one side of the pendulum from above and the other on
the other side of the pendulum from below, and although the impulse
levers may be arranged one on each side of the pendulum as is usual
in several arrangements of escapements, I according to my Invention
arrange the escape wheel or parts thereof, and stops or parts on or of
arms or parts of the said impulse levers, or on or of parts connected
therewith, so as to stop or lock the escape wheel always on the same
side of a line drawn through or between the axes or point or points of
motion of the arms of the impulse levers and the axis of the escape
wheel, or so that the force exerted in any case by the arms employed
may be alike.
The "Denison escapement" as generally used has two sets of teeth,
three for lifting and six for stopping or locking, but the arrangement as
employed by me is adapted to an escape wheel with one cam or tooth
or other number to the "pin wheel," or to other escapements, and the.
locking of the train may take place upon the fan as used with some
gravity escapements.
The escape wheel and the impulse levers are arranged so that a
subsidiary or secondary locking is obtained, by which the action of
the clock or other timekeeper is more regular and certain. This
modification comes into action only when the clock or other timekeeper
is about to "trip" or slip teeth, and thus prevent such "tripping," or if
desired it may be arranged to be constant in its action. This subsidiary
and secondary locking is also applicable to other escapements.
The stops or teeth against which the escape wheel locks are usually
applied on the impulse levers, but this is not necessary if arms or parts
are applied to carry such stops or teeth and enable the pendulum to
give the desired movement when required.
I do not limit myself to the use of two levers, as in certain cases one
or other number may be used, or, when there are more than one, that
they should be swung from precisely the same point of suspension, and
it is not necessary that there should be two stops or pallets for the
escape wheel to lock against, one being sometimes sufficient, or more
than two may be used.
The escapement according to my Invention, with the adaptation of a

page_text: in substitution of the force of gravity, is applicable to other timekeepers.
But that the Invention may be the better understood I will by the
aid of the accompanying Drawings proceed to describe means pursued
by me in carrying the same into effect.
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents the front view of the "escapement," with parts.
arranged according to my Invention, and adapted for use with a clock
or other timekeeper; a and b are the two impulse levers which are
supported by and swing from the axis of motion c, and have impulse
pins a and b respectively for action with the pendulum; d represents
a portion of the pendulum; and e is the escape wheel which is applied
to the axis e, as is well understood.
Figures 2 and 3 represent opposite edge views of parts of this
escapement; Figure 4 is a sectional plan view of the same taken in the
direction of the letters A, B, of Figure 1; and Figure 5 represents as a
plan view the edge of the wheel e, with the pins or studs h, h', in the
opposite sides of the periphery thereof, and indicating the relation,
length, and position of such pins or studs.
In cach of the Figures the same letters indicate corresponding parts
wherever they occur.
and are other arms forming parts of or applied to the upper ends
of the impulse levers a and b. The lower ends of these arms f and g
are formed with or have applied to them the plates or pallets f¹ and g¹
respectively. These plates or pallets are each formed broader at one
end that next the respective arm to which it belongs, and then narrower
from that part to its outer end for g³, the object of which will presently
appear, but I do not confine myself to this form, as for instance such
pallets may be formed with the broad part alone, omitting the narrower
part, when the pins h would also be omitted, and these arms may be
applied in relation to the direction of motion of the escape wheel or
wheels, so that the pins or stops h or h and h¹ may act on the respective
pallets in a direction towards in place of from the axis or axes of the
arms of those pallets so long as the direction of action selected for the
arms correspond. The wheel e is provided not only with the double
row of pins and ³, already referred to, but also near its centre with six

page_text: other pins i, three of which are represented in Figures 1 and 4, as pro-
jecting from one side of the wheel e, and three from the opposide side
thereof, but this arrangement may be varied.
I will now describe the action of the respective parts.
Suppose the
pendulum d to be swinging to the right, it will, as shown, be just leaving
the impulse pin a² of the impulse lever a, and the impulse lever a will
be resting by its projection a¹ against a lifting pin i, and the pendulum
is now acting upon the impulse pin 6 of the impulse lever at the
same time the locking arm is being moved to the right and a locking
pin is escaping from the broad end of the plate or pallet g¹. The
wheel e then moves a of a rotation, moving another pin and thereby
moving the impulse lever a into position for the wheel e to lock itself
with the pallet f₁ of the arm f by a locking pin ¹ on the opposite side,
which in its turn is unlocked for another pin ' to fall on the plate g¹ at
the lower end of the arm g, as described in respect of the plate f¹, but
the plates or pallets f¹ and g¹, as stated, arc of a peculiar shape, the
object of which is, supposing from some cause a locking pin / had not
fallen on the little projection or broad end of a pallet f¹ or g', as the
case may be, the clock would then "trip,” but that in such a case a
safety pin would then fall on the extended part of the pallet f¹ or g¹,
then being held in position by the action of the pendulum on the impulse
pin a² or b², as the case might be, and prevent the clock from really
tripping," this pin would rest on the plate or pallet f¹ or g' till the
impule lever a or b had arrived at its place of rest against a lifting pin i,
as is represented by the Drawings.
The plates or pallets f¹ or g¹ may be continued at their narrower ends
as long as convenient, but a small length will generally be found
sufficient.
2,2, are stops which may be used to prevent the levers a and b moving
the arms fand beyond the range of protection from the pallets f¹, g¹.
These stops,, may be adjustable so as to allow the clock to " run "if
desired for its being so set to time.
In place of the pins i, i, a cam or cams, such as represented by
Figure 6, may be employed, and in place of 6 pins i, three on each side,
only one or other number of pins may be employed, but with any such
alterations the pins or hand will be varied in number, according to
circumstances.

page_text: If desired the pins h or hand h¹ may be applied to a wheel or arms
separate from the axis of the pin i. When pins and ' are used
they may also be variously divided and applied to separate wheels or
arms.
Having thus described my Invention and means which I adopt in
carrying the same into effect, I would have it understood that I do not
confine myself to the precise arrangements of parts as shewn and
described, as the same may be varied without departing from the
peculiar character of the Invention, but what I do claim is, the arranging
or combining parts of clocks and other timekeepers, whereby escape-
ments thereof of the character referred to are acted upon for their
"locking" by arms f, g, and their pallets, operating with suitable
impulse levers as described.
In witness whereof, I, the said Alfred John Higham, have here-
unto set my hand and seal, this Seventeenth day of February,
in the year of our Lord One thousand eight hundred and seventy-
six.
ALFRED J. HIGHAM. (L.S.)