AN IMPROVED METHOD OF SECURING OR FIXING THE PENDULUM OF CLOCKS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by John Ganter at the Office of the
Commissioners of Patents on the 31st October 1882.
JOHN GANTER, of Rosoman Street, Clerkenwell, in the County of Middlesex,
"AN IMPROVED METHOD OF SECURING OR FIXING THE PENDULUM OF CLOCKS
"
My Invention relates to clocks which are enclosed in a wooden or other case
intended to be suspended on a wall or in any other suitable position, and the
pendulum of which is accessible through a small door in the under side or in the
face of the case, and the object is to provide simple means whereby the pendulum
may be securely fixed within the case so as to prevent it moving about when the
clock is being transported from place to place, thus obviating the necessity of
detaching and removing the pendulum from the clock.
The pendulum is essentially of ordinary construction, but the nut working on
the screw formed on the end of the rod, and whereby the pendulum "bob" or weight
can be adjusted on the rod so as to regulate the clock, is recessed in the middle
so as to form an annular groove with a projecting flange on either side. These
flanges are milled, roughened or formed with teeth on their periphery, to facilitate
turning the regulating nut in either direction when necessary to raise or lower the
"bob" or weight.
One end of a flat spring is secured to the pendulum "bob" or weight and its
outer or free end bears on the upper flange of the regulating nut abovementioned,
entering the spaces between the teeth, roughened or milled surfaces on its periphery,
for the purpose of preventing the nut from being turned unintentionally, either
through any jarring motion or while being secured in the case as hereinafter
described.
The means for securing the pendulum consist of a metallic piece or plate projecting
outwards at right angles to the back of the case, to which the ends are secured by
screws or other suitable means in a position almost directly in line with the
regulating nut on the pendulum rod. The holes through which the screws pass to
secure the plate may be elongated so as to form vertical slots to allow of the plate
being adjusted vertically to the exact position desired. A recess is formed in the
plate just large enough to receive the metal remaining between the flanges of the

page_text: regulating nut, and the thickness of the plate is such as to fill up the annular
groove therein, so that the flanges fit over the top and bottom of the plate:
A sliding bolt is fitted to move in guides formed in the plate, so as to be
capable of being brought over the recess therein, and thus secure or lock the
regulating nut.
Instead of making the plate wide enough to fill the annular groove in the
regulating nut it might be made narrower and the sliding bolt arranged to fill up
the remainder of such groove.
The construction of the sliding bolt may be varied, but a convenient mode of
forming the same consists of an angle piece having a part projecting from the
outer arm (which fits over or slides on the outer edge of the plate) so as to cover
the recess in the plate when the bolt is shot, while the other arm of the angle piece
works or slides on the top of the plate. A longitudinal slot is formed through the
plate, and a screw or stud passes through the slot and is secured to the top arm of
the angle piece, a spring plate or washer being inserted between the head of the
screw or stud and the under side of the plate, so as to prevent the bolt shifting
from the position in which it is placed.
The flat spring bearing on the top flange of the regulating nut will prevent the
latter turning when the bolt is shifted so as to bring it between the flanges of the
nut, or to remove it therefrom.
When the "bob" or weight has been adjusted to its proper position on the
pendulum rod, the plate may be secured to the case so as to be directly behind the
annular groove between the flanges of the regulating nut, but it is preferable to
place it in a slightly higher position, so that the pendulum-must be lifted somewhat
to bring the groove in the regulating nut opposite the plate, the extent of the lifting
being such that the pendulum rod will not be disconnected from the clock move-
ment. By thus slightly raising the pendulum its weight (including the "bob")
will be supported by the metallic piece or plate.