Improvements in Door Springs and Checks for Swing-doors, also applicable for Single-doors and Rebated Doors.
Year: 1898

page_text: Date of Application, 15th Oct., 1898-Accepted, 1st Apr.,
1899
COMPLETE SPECIFICATION.
Improvements in Door Springs and Checks for Swing-doors, also
applicable for Single-doors and Rebated Doors.
+
I, THOMAS JONES, of No. 9, Southampton Row, Holborn, in the County of
Middlesex, Manufacturers' Agent, 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 improvements in door springs and checks more
particularly for swing or double-acting doors, but also applicable for single doors
and rebated doors; and the main object of it is to provide means whereby without
increasing the usual and very limited space at disposal for the mechanism, to
obtain as long a throw as possible to a piston working in a cylinder filled with
air or liquid and thereby enabling the employment of a correspondingly long
cylinder and thus increasing the efficiency of the check as hereafter explained.
I would remark that this invention only relates to door springs and checks
employed underneath the bottoms of doors and not to those which are attached
to or which operate in combination with the tops of doors.
The following is a complete description of my invention with reference to the
accompanying drawings forming part thereof and to be read therewith, and in
which:-
Figure 1 is a vertical sectional elevation of my improved door spring or check
fitted with one cylinder, and enclosed in its box or casing; a portion of the door
above also appearing.
Figure 2 is a plan view of the mechanism and case shewn in Figure 1; the
cylinder and piston being in section, and the cover plate of the box removed.
Figure 3 is a vertical sectional elevation of my improved door spring or check
fitted with two cylinders and enclosed in its box or casing and a portion of the
door above also appearing; the positions of the parts being those which they
assume when the door is closed.
Figure 4 is a plan view of the mechanism and case shewn in Figure 3; one of
the cylinders and its piston being in section, and the positions of the parts being
those which they assume when the door is open towards the observer.
According to my invention the box or case a containing the whole of the spring
and check mechanism is sunk into the door sill as usual. This case contains the
usual bolt b which protrudes up into the bottom of the door as a means of connecting
the door with the spring and check mechanism. c, c, are two spring-pressed
levers somewhat resembling in form a pair of ordinary calipers, but instead of the
arms or fingers being connected together at one end by means of a rivet as in
calipers, they are separate and at the end in question are hooklike in form, the said
hooks embracing the noses of a double round-nosed block d, against which they
are spring-pressed one on either side by means of buffer-like springs e, el, acting
parallel with the said block which thus becomes a fulcrum for them. These
levers form the connecting mechanism by which the springs e, el, which are in
reality the door springs provided as an auxiliary to the action of the check, but

page_text: which may be employed alone without the check, are connected with the door; the
crank f being fixed to the bolt b, which latter, as before stated, enters a hole in the
bottom of the door. The end or nose of the crank is preferably provided with a
roller such as g for anti-friction purposes and this roller it will be seen bears
continually at some point in the interior surface of the arms according to the
position of the door at the moment.
The construction which I have described so far, is, I am aware, not novel in
door checks, but what I am now about to describe constitutes the essence of my
present invention.
To the end of the crank f is loosely pivoted at the extremity of the central
leg or arm of a T-shaped lever, t. The said lever for convenience is arranged
parallel with and over the spring-pressed levers above described. Two hinged
bent-levers h, are loosely pivoted at one extremity to blocks i, ¹, fixed to the case
one on either side of and in alignment with the bolt b, at a sufficient distance
therefrom to be out of the range of the crank f. The other extremities of these
hinged bent-levers h, are loosely pivoted to the extremities of the other arms
of the T-shaped lever t. The hinge of these levers is at z.
The check proper consists of one or more cylinders in each of which works a
piston or plunger; the cylinder or cylinders being filled with air or some suitable
liquid.
I am aware that a cylinder and piston or plunger have been already employed
for the same purpose, but such cylinders have contained a strong spring or springs
interposed between the piston-head and the cylinder cover to make up for the
shortness of stroke which the pistons of such cylinders had, and consequently they
were not able to draw in sufficient air to make a reliable cushioning in the cylinder
without the assistance of the said springs.
Hitherto the outer extremity of the piston rod has been connected directly with
the crank thus only a very short stroke was obtained and consequently only a
very tiny cylinder employed. Without taking up any more room than usual I
cause the piston rod or rods to have a much longer stroke than hitherto and this
I effect as follows:-
The crank fas above stated is loosely pivoted at a to the extremity of the central
leg of the T-shaped lever t, and to each extremity of the arms of the said lever I
loosely pivot the outer end of one of the piston rods (when two cylinders are
employed as shewn in Figures 3 and 4), and when only one cylinder is employed
I prefer to attach the outer extremity of the piston rod to the centre of the arms of
the T-shaped levert as shewn in Figures 1 and 2.
By having thus solved the problem of how to obtain a long stroke for the
piston I am thus enabled to employ a much longer cylinder than usual without
requiring additional space, which is a great advantage, as it will hold enough air
for the proper cushioning of the heaviest door without necessitating any auxiliary
springs in the cylinder.
In Figures 1 and 2, I shew the cylinder n fitted with two covers n¹, n2 in one
of which, n, a hole o is made for the ingress and egress of the air or liquid which
provides the necessary cushioning matter.
In Figures 4 and 5 the piston and cylinder are slightly modified, the cylinder
having only one cover n and the pistons j, j so adjusted as to come right out
of the cylinder when the door is open wide. The object of this modification is
to ensure that the cylinder is perfectly brimming full of air before the piston
begins to compress it.
The cylinder may be fixed or it may be pivoted as shewn at ? so that it can
oscillate slightly and thus relieve the piston rod of any strain.
The bent levers h and h¹ are inflexible at their hinge in a backward direction
when opened out in line as shewn in Figures 1 and 2 and being always under the
influence of the springs e, e¹ through the medium of the levers c, c, prevent the
door from swinging past the centre, so that there will not be a continual oscillation
of the door till it comes to rest, but it comes to rest when it arrives at the centre

page_text: the first time the said springs co-acting with the friction of the joints of the said
levers being sufficient resistance to overcome the momentum of the door.
The action of this invention is as follows:-The action of opening the door
by pressing against or pulling it, causes the bolt or stud in the bottom of it to
turn the crank which pulls with it the T-shaped lever, and simultaneously the
roller y on the crank presses open or back, against the action of its spring, one of
the spring levers c, c, according in which direction the door is being opened.
The T-shaped lever in turn then draws out the piston rod which moves (being
guided by the cylinder) practically in a direct line, which action draws the air
or liquid into the cylinder by creating a vacuum. On the door being released,
the crank and T-lever tend to assume their normal positions by reason of the
spring which was compressed in the opening movement of the door, exerting its
pressure upon the crank through the medium of the spring-pressed lever on that
side. The piston is thus forced back again into the cylinder not suddenly but
gradually as it meets with the resistance of the air or liquid which it has to
drive out before it.
A stop q is provided in the case for the tip of the free ends of the levers c,
butt against.
c¹ to
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a door check and spring of the class referred to for the bottoms of doors,
the means for giving to the piston rod a long and rectilinear stroke, consisting
of the combination with the bolt crank (f) and the outer end of the piston rod
or rods, of the T shaped or three-armed lever (t) as described and set forth.
2. In a door check and spring of the class referred to, for the bottoms of
doors, the means for giving to the piston rod a long and rectilinear stroke,
consisting of the combination with the bolt crank (f) the piston rod or rods, the
levers (c, c) the springs (e, e¹) and the fulcrum block d, of the T shaped or three-
armed lever as described and set forth.
3. In a door check and spring of the class referred to, for the bottoms of doors,
the means for giving to the piston rod a long and rectilinear stroke, consisting
of the combination with the bolt crank (f) and the outer end of the piston rod
or rods, of the T shaped or three armed lever and the hinged bent levers (h, h¹)
arranged and co-operating as described and set forth.
4. In a door check and spring of the class referred to, for the bottoms of doors,
the employment in combination with the Tshaped lever of two separate cylinders
and pistons operated alternately by one and the same crank, in the manner and
for the purposes described.
5. A door check and spring of the class referred to, for the bottoms of doors,
constructed operated and working substantially as described and illustrated in the
accompanying drawings.
6. In a door check and spring of the class referred to, for the bottoms of doors,
the combination with the bolt crank (f) and the T shaped lever (t) of one or more
pistons and one or more cylinders, the latter devoid of any spring or springs but
filled with air or liquid only, and the piston or pistons being adjusted so as to
come either nearly or quite out of their cylinder or cylinders on the outward
stroke substantially as described and illustrated in the accompanying drawings.
Dated the 15th day of October 1898.
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.