IMPROVEMENTS IN APPARATUS FOR REGULATING THE MOTION AND ACTION OF DOOR SPRINGS
Year: 1871

page_text: LETTERS PATENT to Alexander Charles Moffatt, of Princes Street,
Leicester Square, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR REGULATING THE MOTION AND ACTION OF
DOOR SPRINGS."
Sealed the 15th December 1871, and dated the 19th June 1871.
PROVISIONAL SPECIFICATION left by the said Alexander; Charles
Moffatt at the Office of the Commissioners of Patents, with his
Petition, on the 19th June 1871.
I, ALEXANDER CHARLES MOFFATT, of Princes Street, Leicester Square,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR REGULATING THE MOTION AND
ACTION OF DOOR SPRINGS," to be as follows :-
This Invention relates to certain improvements in apparatus for
regulating the motion and action of door springs, the object being to
effect an uniform closing of a spring door in the central or mid linė

page_text: of motion, although the sole plate fixed in the floor may have changed
its original situation by the loosening of the screws or the strain of the
leverage.
In order to effect this result the axis on which the door swings is
provided (beneath the sole plate in the recess of the metal chamber)
with a crank set or keyed horizontally, such crank having a disc, roller,
or circular bearing plate thereon, the two opposite surfaces of the disc
bearing on two curved levers set on fulcra near the centre of the spring.
Now, in ordinary circumstances, where the sole plate or chamber is in
its true position, these curvilinear levers are at all points equidistant
from the centre of motion of the axis, and they are kept in such position
by means of an adjustable bar with a projection thereon so that each
extremity of the levers butts against the projection. But when the
door plate is out of its true line this adjustable bar is shifted in the
requisite direction, so as to compensate for the variation of the medial
line; and consequently the motion and action of the levers is regulated
and controlled by means of the central projection or stop for closing
the door, and by the extreme side stops for each opening.
The mainspring is connected at each extremity with the arm of
each curved lever at about such point as may be necessary between
the fulcra and the curvilinear levers; or if the spring is required to be
of a larger diameter, its points may be brought in contact or fixed to
the curvilinear portion of the lever. The action will be the same; for
since the spring presses constantly on each arm of the lever and forces
both in contact with the stop to close the door, it necessarily follows
that the point of closing must be regulated according to the position
or angle of the central stop, the internal curves of the levers at the
closed position fixing the disc of the crank in or out of line with the
medial line of the door plate.
The sliding bar contains a slot at or near cach end, so that when it
is shifted two set screws may be tightened on the slots, and passing into
threads in the box may hold the same in the required position; or a
horizontal lever may be applied to the regulating bar, whereby it may
be shifted, and the lever can then be secured to the chamber by a set
screw.
The stems of the curvilinear crank levers may be serrated or notched
with saw teeth in order that the spring may be adjusted to different
powers to suit the unequal pressure on each side of the door. The

page_text: teeth hold the extremities of the spring in position, notwithstanding
the change in the angles of the crank caused by the position of the
determinable line of the door centre.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Charles Moffatt in the Great Seal Patent
Office on the 19th December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
CHARLES MOFFATT, of Princes Street, Leicester Square, in the County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of June, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Charles Moffatt, Her
special licence that I, the said Alexander Charles Moffatt, my executors,
administrators, and assigns, or such others as I, the said Alexander
Charles Moffatt, 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 Invention
for "
IMPROVEMENTS IN APPARATUS FOR REGULATING THE MOTION AND ACTION
OF DOOR SPRINGS," upon the condition (amongst others) that I, the said
Alexander Charles Moffatt, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, 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 Alexander Charles Moffatt, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
My Invention relates to certain improvements in apparatus for regu-
lating the motion and action of door springs, the object being to effect

page_text: an uniform closing of a spring door in the central or mid line of
motion, although the sole plate fixed in the floor may have changed its
original situation by the loosening of the screws or the strain of the
⚫leverage.
In order to effect this result the axis on which the door swings is
provided (beneath the sole plate in the recess of the metal chamber)
with a crank set or keyed horizontally, such crank having a disc, roller,
or circular bearing plate thereon, the two opposite surfaces of the disc
bearing on two curved levers set on fulcra near the centre of the spring.
Now, in ordinary circumstances, where the sole plate or chamber is in
its true position, these curvilinear levers are at all points equidistant
from the centre of motion of the axis, and they are kept in such position
by means of an adjustable bar with a projection thereon so that each
extremity of the levers butts against the projection. But when the
door plate is out of its true line this adjustable bar is shifted in the
requisite direction, so as to compensate for the variation of the medial
line; and consequently the motion and action of the levers is regulated
and controlled by means of the central projection or stop for closing
the door, and by the extreme side stops for each opening.
The mainspring is connected at each extremity with the outer arm
of each curved lever at about such point as may be necessary between
the fulcra and the curvilinear levers; or if the spring is required to
be of a larger diameter, its points may be brought in contact or fixed
to the curvilinear portion of the lever. The action will be the same;
for since the spring presses constantly on each arm of the lever and
forces both in contact with the stop to close the door, it necessarily
follows that the point of closing must be regulated according to the
position or angle of the central stop, the internal curves of the levers
at the closed position fixing the disc of the crank in or out of line with
the medial line of the door plate.
The sliding bar contains a slot at or near each end, so that when it
is shifted two set screws may be tightened on the slots, and passing into
threads in the box may hold the same in the required position; or a
horizontal lever may be applied to the regulating bar, whereby it may
be shifted, and the lever can then be secured to the chamber by a set
screw.
1
1

page_text: powers to suit the unequal pressure on each side of the door. The
teeth hold the extremities of the spring in position, notwithstanding the
change in the angles of the crank caused by the position of the deter-
minable line of the door centre.
From the foregoing description my Invention will be readily under-
stood; I annex the accompanying Drawings to illustrate the best means
of carrying the same into practical effect. The modifications described
will therefore be easily comprehended.
The Drawings represent the simplest form of door spring and the
most durable arrangement. Fig. 1 shews a plan view of the general
action of the door spring, and Fig. 2, the side view of the guide plate
or shoe on which the door is set by the requisite screws; Figs. 3, 4,
and 5 shew respectively the forms of the sliding and regulating stops
requisite for controlling the action of the levers, and consequently for
regulating the exact position of the doors.
In Fig. 1, a is the box or bed plate and recess in which the working
parts are contained; the circular or curvilinear compound spring b, b,
is shewn pressing on the teeth of the levers c, c; these levers take
their bearing from the projection d by means of the quadrants or other
circular bearings e, e.
The extremities c³, c², of the levers c gear with
the adjustable stop f, capable of sliding in the slots f¹ and of being
tightened by the screws g, g. Over the plan Fig. 1 a plate of brass.
or other metal is placed, with screw holes corresponding with those of
the box or frame; and above this frame the guide plate of the swing
door is set in its bearing, shewn in Figs. 1 and 2 by the letter ; then
i is the axis which carries the hinge; k, the roller actuating the levers ;
and 1, the square stem on which the guide plate is secured. In Fig. 1
the plate and the guide are, of course, removed in order to shew the
interior arrangements of the spring.
Fig. 3 shews an elevation of the adjustable stop ƒ on its sliding
vertical plate f¹. I propose to apply beneath this plate and on the bed
plate of the apparatus a strip of leather or other suitable material in.
order that the set screws may be enabled to fix the same firmly against
the action of the springs and levers, notwithstanding the position of
the apparatus' when once set in the floor of a building, because it is
obvious that the mere adjustment of the vertical slide'f', f', will serve
to regulate the centre of motion of the compound springs c', c', as before
described.

page_text: In Fig. 4 an under plan of the adjustable plate f¹, f¹, is shewn with
transverse teeth which will bite into corresponding teeth or into leather
or other fabric when tightened by the screws g; Fig. 5 shews another
example of Fig. 4 where the serrated grooves are, longitudinal, the object
being the same.
I also propose to electrotype or coat the plate and shoe with tin or
other metal, in order to preserve the same from atmospheric influence,
or from the action of oil.
Having now described the nature of my said Invention, and the
manner in which the same is to be performed, I would remark in con-
clusion that I do not limit myself to the precise details or configuration
of parts which I have described and shewn, as the same may obviously
be varied or modified (as previously described) without in any degree
departing from the principles of the Invention; but what I claim and
desire to be secured to me by the herein in part recited Letters Patent
is, the general arrangement, combination, and construction of parts
forming an improved apparatus for regulating the motion and action of
door springs as described and shewn; but especially I claim the method
of regulating and controlling or adjusting the movement or action of
such springs by means of the adjustable vertical slide or its equivalent,
substantially as herein specified and shewn.
In witness whereof, I, the said Alexander Charles Moffatt, have
hereunto set my hand and seal, this Eighteenth day of December,
in the year of our Lord One thousand eight hundred and seventy-
one
Witness,
ALEX: PRINCE,
Office for Patents,
4, Trafalgar Square,
Charing Cross.
A. C. MOFFATT. (L.S.)