Year: 1886

page_text: I, JOHN JAMES PURNELL, of the Atlas Works, Webber Street, Blackfriars
Road, in the County of Surrey, Pattern Maker, 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 objects of my Invention are to secure the easy opening, and the effectual
closing, of a door. The apparatus by which these desirable ends are obtained, and
especially those parts which comprise, or are closely related to, my Invention, are
represented on the accompanying sheet of drawings.
Figure 1, is a vertical longitudinal section, and Figure 2 a plan, of the internal
arrangements of my apparatus. A is a box or reservoir, made of metal or other
material, in which the apparatus is placed. B is a cylinder, containing a spring, c,
piston, d, piston-rod, c, and connecting rod, f. The head of the connecting-rod is
attached to a crank, g, which works on a pin, h. The upper end of this pin is pro-
longed and enters the under framing of the door, to which it is fixed.
The action of my Invention may be thus described:-The reservoir is filled, or
partially filled, with oil or other liquid. The figures on the drawing represent the
apparatus as it would appear when the door to which it is attached is wholly
closed. As the door opens, so the pin, h, being fixed to it, follows the segmental
movement thus made, and would continue to do so until the door has reached its
utmost swing. By this means action is communicated to the piston, and forces it
towards the other end of the cylinder. As this movement of the piston proceeds,
the oil in the reservoir is gradually drawn into the cylinder through a properly
proportioned orifice, i, in the piston, or in the end of the cylinder, or in any other
suitable place, and its action is regulated by the valve, k. When the door-after
being more or less opened-is left entirely to the action of the apparatus, it is
obvious that the spring, which has been compressed by the aforesaid movement of
the piston, will immediately take a reactive course and tend, whilst forcing the
piston back, to close the door. The fluid which has entered the cylinder, and
followed, the piston in its forward course, is now pressed upon by the backward
movement of the piston, and effects its escape from the cylinder by means of an
orifice, m, having dimensions calculated to regulate the rapidity with which the
oil is allowed to make its exit, and thus to hasten or retard the closing of the
door. This orifice is situated at some convenient point, such as that shown on
the drawing.

page_text: I now proceed to point out two peculiarities pertaining to the apparatus which
constitute the chief parts of my Invention. A door may, no doubt, be opened and
closed with facility by means thus far described; but my Invention does more: it
effects such movements with an ease and efficiency never yet attained, First-
Instead of the rigid action which follows from the use of a fixed cylinder, I produce
a perfectly smooth and easy movement by giving to the cylinder an oscillatory
motion on the pivot, p. This is perfectly clear; and in order to give adequate
scope for the oscillation, it will be seen that the reservoir gradually widens as it
approaches the crank end of the cylinder. Secondly-I ensure the absolute closing
of the door, check its tendency to yield either to the right or the left, and thus
effectually prevent the ingress or egress of air, by the very simple device of giving
a flat surface to a certain portion of the crank, as shown in figure 2, and also in a
cross section apart. Thirdly-My apparatus can be placed so that no part of it
will project beyond the inner edge of the door; thus rendering it unnecessary to
cut into, and so weaken, the door-post.
My apparatus is unchangeably applicable to a single or double acting door, to
either a right or left handed door, and to a swing door.
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.) The application and use of an oscillating cylinder, in the manner, and for
the purposes, herein-before described.
(2.) The special form given to the crank, in that part of its surface which comes
into direct contact with the connecting-rod, as described and shown.
Dated this 18th day of May 1886
JOHN JAMES PURNELL.