IMPROVED SELF-ACTING APPARATUS FOR CLOSING DOORS
Year: 1874

page_text: LETTERS PATENT to Lazarus Threlfall, of Colne, in the County of
Lancaster, Gentleman, for the Invention of "IMPROVED SELF-ACTING
APPARATUS FOR CLOSING DOORS."
Sealed the 16th October 1874, and dated the 20th April 1874.
PROVISIONAL SPECIFICATION left by the said Lazarus Threlfall at
the Office of the Commissioners of Patents, with his Petition, on
the 20th April 1874.
I, LAZARUS THRELFALL, of Colne, in the County of Lancaster,
Gentleman, do hereby declare the nature of the said Invention for
"IMPROVED SELF-ACTING APPARATUS FOR CLOSING DOORS," to be as follows:-
The first part of my Invention consists in an arrangement of threo
pullies and a weight connected by a 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 consists of a spring plate. with a face of two convexes
between which is a concave the thickness of the door. In the centre of

page_text: this concave space I make a hole by which I screw it to the under side
of the door frame into which the door fits and works.
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 make a case,
or I make the door post a box, up and down which a weight can freely
work. To the top swing corner of door I secure one end of a cord, chain,
or equivalent, passing such in the groove of or between the two pullies
horizontally hung, and over the pulley immediately behind vertically
hung, and connect it then to a weight behind front door post or box.
It will thus be seen that whichever way the door opens one of the two
pullies will receive the cord, the weight will be sufficient to at all times
close the door, and when closed to keep it so.
For the second part of my Invention I provide a steel spring plate of
the shape before mentioned, which I screw to the under side of the
door frame, so that the front edges give way when the door presses
against them, coming in or out, but when it is closed the door is firmly
shut. These can be used in combination or separately.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Lazarus Threlfall in the Great Seal Patent Office
on the 19th October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LAZARUS
THRELFALL, of Colne, in the County of Lancaster, Gentleman, send
greeting.
2
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Letters Patent, bearing date the Twentieth day of April, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Lazarus Threlfall, Her special licence a
that I, the said Iazarus Threlfall, my executors, administrators, and
assigns, or such others as I, the said Lazarus Threlfall, my executors,
administrators, and assigns, should at any time agree with, and no

page_text: 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 "IMPROVED SELF-ACTING.
› APPARATUS FOR CLOSING DOORS," upon the condition (amongst others) that
I, the said Lazarus Threlfall, my executors or administrators, by an in-
strument 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 Lazarus Threlfall, 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, reference being had to the accompanying Drawings,
and to the several Figures marked thereon. In the several views similar
parts are marked by corresponding letters of reference.
Fig. 1 is a plan and side elevation of a triangular pulley-bracket for
an ordinary single swing door opening both ways (or one way only).
The return plate a is screwed to the face of the side casing at the very
top of the frame, the centre exactly opposite the nose of the door when
shut; the cord is secured to the nose of the door passed, as shown,
between the horizontal pulleys c, over the vertical one d, and to the
weight x, Figs. 5 and 8, which will have the effect of bringing the door
back to the centre again whichever way it may be opened.
Figs. 2 shows an arrangement of four pulleys c on a square plate for
double doors meeting in the middle. The plate e is screwed into the top
frame or casing by screws f. The top of each door is reduced a little to
allow the cord to work without friction. For neatness and concealment
I pass the cord through a tube.
Fig. 3, an arrangement for doors already fixed and where there is not
room for a weight within the casings, then instead of passing the cord
over the vertical pulley, as in Fig. 1, bringing it from the double pulleys
to another horizontal pulley to be fixed on the outside casing, and then
conducted to bracket, Fig. 4, which I fix vertically. This bracket is
formed to keep the weight from the wall in moving up & down.

page_text: Fig. 5 shows the weight suspended, the higher part of suspending rod
is flattened to receive additional weights if necessary.
Fig. 6 shows spare weights to slot on the flattened rod if required.
Fig. 7 shows a convex steel spring to be fixed immediately under the
face of plate (Fig. 1), or to the top casing over the nose of the door.
This is calculated to check any too rapid descent of the weight, and to
keep the door in its place when shut, and removes the necessity of a
lock, latch, or catch of any kind.
Where any heavy weights are necessary a spiral steel-wire spring is
attached as part of the suspension cord.
For a single door opening one way only half of the convex spring
would be used.
Having described my Invention and the several ways of application,
I wish it to be understood that I do not confine myself to the precise
details I have had occasion to describe and refer to, as many variations
may be made in detail without deviating from the principle or main
features of my Invention; but what I claim as secured to me herein
is,―the several methods, or any mechanical equivalent of the same, for
"Self-acting Apparatus for Closing Doors," substantially as herein-
before set forth.
In witness whereof, I, the said Lazarus Threlfall, have hereunto
set my hand and seal, this Fift day of October, in the year of
our Lord One thousand eight hundred and seventy-four.
LAZARUS THRELFALL. (L.S.)
Witness,.
JOHN LEWIS,
Engineer & Patent Agent,
Preston,
Lancashire.