Improvements in Escapements for Clocks.
Year: 1898

page_text: Improvements in Escapements for Clocks.
I, LAURENCE ERIKSON, Jeweller, of 1926, Sherman Avenue, Evanston, County of
Cook, State of Illinois, United States of America, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The present invention relates to that class of escapements in which the pendulum
is entirely free and detached from the balance of the mechanism, excepting during
the brief intervals at which it is either giving or receiving an impulse. The
object of the invention is to provide an improved escapement of this class, and
more particularly stated, to provide an escapement of this class in which, as near
as possible, the parts are balanced and so disposed that the conditions are similar
during each and every beat of the pendulum, to the end that the impulses given
to and received from the pendulum shall be uniform.
To this end the invention consists in the features of novelty that are hereinafter
fully described with reference to the accompanying drawing, which is made a
part of this specification and in which
Figs. 1 and 2 are, respectively, a front and a rear elevation of an escapement
embodying the invention, Fig. 1 showing the parts in the positions which they
occupy when the pendulum is at one extremity of its stroke, and Fig. 2 showing
the parts in the positions which they occupy when the pendulum is at the opposite
extremity of its stroke.
A represents a portion of the pendulum, which is suspended in customary
manner and is provided at its lower end with a weight. B is the escapement
and C the pallet. In the drawing the other parts of the works are not shown for
the reason that their construction is fully understood by those skilled in the
art and the present invention is in no way concerned with them further than that
they shall be of such construction that they will impart movement to the escape-
ment wheel in the direction of the arrow. The escapement wheel and pallet shown
in the drawing are of the type used in that class of escapements known in the art
anchor-escapements."
as
"
The pallet is secured to a rock shaft D to which latter is secured a lever which is
adapted and intended to move, with the rock shaft, equal distances in both
directions from a horizontal position, its movement being limited by stops F¹.
One arm E, of the lever is provided with a tappet e and the other arm, E, is
preferably provided with a counterweight E², the object being that there shall be
an equal amount of weight upon opposite sides of the rock shaft to the end that
the parts carried by it shall have no tendency to move it in either direction.
The pendulum A is provided with two cam surfaces a disposed opposite each
other and so that at which ever extremity of its stroke the pendulum may be,
the tappet a will lie in the path of one of the cam surfaces, so that upon the return
stroke said cam surface will come in contact with the tappet and move it to
such position that the pallet is moved to a position which will enable the escape-
ment wheel to turn one space. In moving this one space the escapement, wheel,
CD
011

page_text: acting upon the pallet and through the medium of the lever E, causes the tappet e
to be moved away from the cam surface a² which engaged it as last aforesaid and
into engagement with the opposite cam surface a², and this latter engagement
gives impetus to the pendulum. These operations are repeated at each beat of
the pendulum.
In the operation of this device the pendulum is entirely free and detached from
the works excepting during the brief intervals when it is either giving an impetus
to or receiving an impetus from the tappet e.
By disposing the lever which carries the pallet in the substantially horizontal
position described, and by balancing the parts carried by the rock shaft, similar
conditions will be presented at each and every beat of the pendulum and this
is of prime importance in a time piece, since its accuracy requires that there shall
be no variation in the conditions. The impetus given by the pendulum should
be the same when moving in one direction as it is when moving in the opposite
direction, and the same is true of the impetus given to the pendulum, and hence
the importance of having the parts balanced in all of their possible positions.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
An escapement for clocks characterized by a pendulum which is entirely free
and detached from the works excepting at the brief intervals when it is either giving
or receiving an impulse, said pendulum having a pair of oppositely disposed cam
surfaces, an escapement wheel, a pallet engaging it, a rock shaft carrying the
pallet, a lever carried by the rock shaft and disposed in a practically horizontal
position, and a tappet carried by the lever and adapted to co-operate with the cam
surfaces of the pendulum, the parts carried by the rock shaft being balanced sub-
stantially as set forth.
Dated this 10th day of April 1808