PROVED HANGING AND SELF-ACTING APPARATUS FOR CLOSING SWING AND OTHER Doors
Year: 1876

page_text: COMPLETE SPECIFICATION filed by Lazarus Threlfall at the Office of the
Commissioners of Patents on the 13th May 1876.
"IM-
LAZARUS THRELFALL, of Colne, in the County of Lancaster, Gentleman.
PROVED HANGING AND SELF-ACTING APPARATUS FOR CLOSING SWING AND OTHER
Doors."
On the Twentieth day of April 1874 Letters Patent were granted to me,
Numbered 1357, for "Improved Self-acting Apparatus for Closing Doors," my
present Invention consists of further improvements in that Invention, with some
alterations and additions.
By reference to my before-mentioned Patent it will be seen that the first part of
that Invention consists of an arrangement of three pullies and a weight. This
weight I dispense with, and for such and the cord substitute an elastic or india-
rubber cord, spiral or other spring with such cord. To the outer or swing edge (at
top) of any door or doors, so that, however left by the person passing through, the
door or doors close by the aforesaid arrangement.
The second part of my Invention remains the same, as in Fig. 7 of my before-
mentioned Patent, and is a spring plate with a face of two convexes, between which
is a concave space the thickness of the door. This I may use in combination with
the before-mentioned or without; where there is a strong current of air it will keep
the door in position.
For double folding doors I use the arrangement of four pullies on a square plate,
more simply constructed and easier got to, which will be seen by reference to the
Drawings herewith. In the first part I place above the top corner and outside of
the door frame, and fitted into such frame, a plate so made as to hang two pullies
horizontally edge to edge, and as near as desired another pulley behind placed in a
vertical position. Behind the front door post I leave sufficient room in which the
elastic cord or spring fastened to the botton at stretch, and passing over the ver-
tical pulley, may work freely. To the top swing corner of door I secure one end of
cord, or carry it along a groove in the top edge of such door, securing it at any
distance along such groove, the other end passing between the two horizontal
pullies, and down the back of the front door gamb, over the pulley immediately
behind, vertically hung, and secured below at any length required.
I most cases I would effect the same purpose by means of a two-pulley plate
fixed in the frame of the door at the top corner, or anywhere along the top part of
the frame, as before I cut a grove along the top of the door inward a short distance
DC11

page_text: to secure the cord, the other end of such cord may pass along a groove, provided in
the top of such door frame after passing between such two pullies, or such other end
after passing between these two pullies may go through the door frame, and be
secured behind or over a single vertical pulley, and down in a groove at the back
or front of door jamb, and secured at any length suitable to the closing strength
desired.
It will thus be seen that whichever way the door opens one of the two horizontal
pullies will receive the elastic cord, which will be sufficient at all times to close the
door, and when closed to keep it so.
Instead of elastic india-rubber cord or spiral spring an ordinary cord with
weights may be used, but the noise made is very objectionable, more costly, and also
requires a box or pocket to work in, not easily applied to casings already fixed,
whilst the clastic cord is perfectly silent.
For the second part of my Invention I provide a steel spring of the before-
mentioned shape, which I screw to the under side of the door frame, so that the
front edges or ends give way when the door presses against them coming in or out,
but when it is closed the door is held to its place; these can be used in combination
or separately.
The addition to my before-mentioned Patent further consists of a new method of
hanging doors by pivot and plate at top and botton, which very much eases the
nction of the door, and is very simply applied.
Figs. 1, on Drawing, is plan and side elevation of a triangular pulley bracket for
an ordinary single swing door opening both ways (or one way only if required).
The return plate a is secured to the plate of the side casing at the very top of the
fraine, the centre exactly opposite the nose of the door, the elastic cord passing
down a groove in the casing of the door, as shown, between the horizontal pullies o
over the vertical one d, which will have the effect of bringing the door back to the
centre again whichever way it may be opened.
For casement already fixed, and where there may not be room behind, I substitute
pulley bracket with four pullies, as shown in Figs. 7, bringing the cord over from
back to the front, then carry it down in a groove or a tube, or conceal it with a
hollow moulding.
Figs. 2 shows an arrangement of four pullies c on a square plate for double doors,
meeting in the middle; the plate c-is screwed to centre of top of door frame.
One end of the elastic cord will be fastened in a groove in the top casing, the other
through or between two pullies to the nose of or up a groove of one door, same as
before described, and if length be required down behind door frame any length
required for the degree of tension. The top of each door is reduced a little at the
extreme corner to allow the cords to pass cach other, and work without friction.
For neatness and concealment the cord inay pass through a tube. Genuine india-
rubber solid cord may be stretched to three times its length, and be held at that
tension for an indefinite period without detriment to its contractive power, and
without extreme frost or great heat and friction is almost indestructable.
Fig. 3 shows a double convex steel spring to be fixed immediately under the
face of plate, Fig. 1, or to the top casing over the nose of any door, for double
doors may be screwed on with the four-pulley plate. The door upon reaching the
centre in its place when closed requires neither lock, latch, nor catch of any kind
to keep it in its place, and yet is easily opened by a little pressure of the hand
against the door. For a single door opening one way only one-half the spring only
would be required.
Fig. 4 shows a pair of folding doors with one method of my improvement
applied, the dotted lines showing the direction the cord is designed to take.
Fig. 5 shows a single door, and one method of my improvements applied, the
dotted lines showing the direction the cord is designed to take, but I decidedly
prefer the following, Fig. 6.
Fig. 6 shows a single pair of pullies, which I may substitute for pullies, Figs. 1
or 7, as they may be fixed anywhere between the nose of the door at top and heel

page_text: at back, the stretching elastic cord carried in top casing only or in a groove, as
before specified, but either front or back.
Fig. 7 is already described in connection with Fig. 1.
Figs. 8, 9, and 10 shows front and side views with plan of my hanging
appliances; and Fig. 11, the plate for them to work in one at top and one at bottom
of door.
I do not confine myself to the precise details I have had occasion to describe and
refer to, as many variations may be made without deviating from the main features
or principle of my Invention; but what I claim as secured to me herein is, the
several methods and appliances or their mechanical equivalents combined or separate
with the clastic or india-rubber cord or, its equivalent, substantialy as and for the
purposes herein-before set forth.
In witness whereof, I, tho said Lazarus Threlfall, have hereunto set my hand
and scal, this
day of May, in the year of our Lord One thousand
.
eight hundred and seventy-six.
Witness,
JOHN LEWIS,
Engineer & Patent Agent,
Preston,
Lancashire.
LAZARUS (LS.) THRELFALL.