IMPROVEMENTS IN PNEUMATIC APPARATUS DESIGNED TO SERVE AS A SPRING, AND APPLICABLE FOR BUFFERS, BEARINGS, AND OTHER APPARATUS REQUIRING ELASTIC OR YIELDING SUPPORT."
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by George Robert Joughin at the Office
"
of the Commissioners of Patents on the 27th January 1879.
GEORGE ROBERT JOUGHIN, of Inchicore, Dublin, Ireland. 'IMPROVEMENTS IN
PNEUMATIC APPARATUS DESIGNED TO SERVE AS A SPRING, AND APPLICABLE FOR
BUFFERS, BEARINGS, AND OTHER APPARATUS REQUIRING ELASTIC OR YIELDING
SUPPORT."
My Invention relates to a pneumatic apparatus or air spring in which a piston
and a diaphragm or diaphragms enclosed within a cylinder act in such a manner
as to render the said apparatus very advantageous as a spring for railway buffers
or bearings or for other like purposes. The said improvements consist chiefly in
means for controlling the recoil of the spring to any desired extent.
In one form of the said apparatus I use a diaphragm which may be so formed
and arranged that the piston will push it up, but it will be retained in place or
kept from descending below its proper position by the sides of the cylinder, or by a
spindle projecting from the cover or from the piston when the piston commences to
return. The said diaphragm may have a large valve opening upwards, and has a
small hole drilled through it so that when the piston is pushed up the air between
the piston and diaphragm will pass to the other side of the said diaphragm, but
when the piston commences to return the said valve will close and the air can then
reach the piston only by the small hole. It is obvious that this hole may be of any
required size, and therefore the recoil can be controlled or regulated as desired. The
effect required, namely, an easy recoil, may be obtained also by a modified con-
struction of the said apparatus, in which I use a series of diaphragms or plates
arranged on a central spindle one above the other with spaces between them, and
seated in the interior of the cylinder. When the piston is pushed inward or into
the cylinder the air between the piston and lower diaphragm, or between the
diaphragms, will pass to the other side of each diaphragm, but when the piston
commences to return one of the diaphragms immediately rests on its seat, thus
compelling the air to act on the piston through the holes therein and so obtaining
an easy recoil.
The said diaphragms may be faced with leather or other suitable material to
ensure their having a tight joint on their seat if such will be required, and by
increasing the number of diaphragms, thus bringing them closer together the recoil
may be made very delicate. The said diaphragms may also be guided in their

page_text: action by other means than the central spindle, for instance, by hinging them to the
sides of the cylinder.
The air can be retained in the cylinder-by-any suitable means, but I_prefer_to_
use for this purpose a device termed a hydraulic collar on the piston, the cylinder
-being-partly filled with a suitable liquid. When the said cylinder has to work on
-its-side_or_in_any_other_position where the liquid will not cover the hydraulic
collar_by_gravitation, I make the piston in two parts, separating them-by-an-inter-
posing-liquid-and-attaching-a.hydraulic collar to each portion; then when they are
screwed together, no matter in what position the cylinder is turned, the liquid
cannot escape but will always cover the collars, thus securing an air tight joint.
In some instances I may use an extra or additional collar turned towards the
inside of the cylinder, which collar serves very effectually for retaining the air, as
in the working of the piston in the cylinder it will always be kept moist.
When the stroke of the piston is required to have a definite length I prefer to use
one diaphragin. When a variable length of stroke is required I use a number of
diaphragms, arranged as above described; when the cylinder is to occupy any other
position than an upright one springs are arranged in combination with the
diaphragms or plates to press them to their seats, and I may have two spindles
attached to the piston to assist in guiding them. I provide means for filling the
cylinder with air at any desired pressure by an opening made in the side or top of
the said cylinder or in the piston,' and provided with a valve, and the cylinder may
be filled through this opening in any convenient manner.