Improvements in Air-brakes.
Year: 1889

page_text: Date of Application, 21st June, 1889-Accepted, 27th July, 1889
Improvements in Air-brakes.
I, FREDERIK ARNOLD HOLLEMAN, of Oisterwyk Netherlands, Holland Gentleman,
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 :-
This my invention has reference to certain new and useful improvements in air-
brakes, and it consists in the combination with the main air pipe, cylinder, and weighted
lever, of a regulating valve hereinafter described and claimed.
By this my invention an ordinary lever brake may be converted into an automatic
brake, which will operate with a constant and unvarying pressure, and simul-
taneously throughout the length of the train however numerous the carriages or
trucks may be.
I now proceed to describe my said invention, reference being had to the accom-
panying drawings, and the figures and letters of reference marked thereon :-Similar
letters indicating like parts throughout all the views.
Fig. 1, is a longitudinal sectional elevation of part of a truck, showing my improved
valve in place, Fig. 2 is a sectional elevation of my improved regulating device
showing the valve in its normal position, and Fig. 3, is a like section showing the
valve under pressure. Fig. 4 is a cross section through the air cylinder showing its
connection with the main pipe. Fig. 5 is a cross section of the valve casing and
shield suspended on the main pipe.
In the drawings, a refers to the main air supply pipe, which runs throughout the
length of the train, and to which is connected on every truck or carriage an air
cylinder b, of small diameter. This said air cylinder is fitted at its ends with
imperfectly and loosely fitting covers c, which will allow air to enter between them
and the cylinder. Two pistons d, fitted with piston-rods e, are free to travel longitu-
dinally within the cylinder b. To each of the piston-rods e is suitably secured a chain,
metallic rope, or other equivalent appliance, which runs over suitable pulleys f, and is
attached to the lever h, at g. The lever h, carries a weight i, which is adapted to
travel in a frame j, and which, by its weight will, in combination with its connecting
levers and k, cause the brakes to be applied to the wheels in the ordinary way,
when released. This said weight may be supported at times by a bar 1, which may be
slid underneath the lever h.
To the main air supply pipe a, is connected my improved regulating valve m,
which consists essentially of a cylinder or casing n, having closed ends, and having a
flat surface upon its upper side, which has an oblong aperture o, and a square
aperture p.
These said apertures are covered by a slide or valve q, in which is secured a
projecting stud or pin r, which extends through, and is free to travel in the slot or
aperture o, and enters a suitable aperture in the valve s. The said valve 8, is loosely
fitted and adapted to travel in the valve casing n, and is formed with a partition t
and an inwardly projecting flange w. Between the two flanges u and w, is a spiral
spring y, which tends to keep the valve s, in the forward end of the casing n.
In order to prevent dirt and dust from interfering with the working of the valve, it
is enclosed in a metal cylinder or shield z, having a cover z¹, and an opening,
through which air enters to the valve after being filtered through the felt, cotton, or
other filtering material 2.
The operation of this my invention is as follows:-After a vacuum has been created
in the main pipe a, and in the brake cylinder b, the lever h, with the weight i, is held
suspended as shown in Fig. 1. When however it is necessary to apply the brakes
air is admitted into the main pipe a, and the vacuum being destroyed allows the

page_text: pistons d, to be drawn along by the weight i, in falling, which in combination with
the levers k, will apply the brakes with a force depending upon the amount of air
admitted.
The main pipe a, being too long to admit air to apply the brakes simultaneously
throughout the length of the train, I provide the regulating valve m, which is
applicable for use with any vacnum brake, which is connected to the main pipe a, on
every truck or carriage as shown.
The vacuum created in the main pipe extends into the casing n, of the regulating
valve m, to the right of the division t, and inasmuch as the valves, is fitted loosely in
the casing n, a vacuum is likewise established to the left of the division t.
When the brakes are to be applied lightly, the slight pressure arising in the main
can extend itself along the sides of the valve s, without moving it against the pressure
of the spiral spring y, but when it is necessary to apply the brakes with full force,
and much air is allowed suddenly to enter the main pipe a, the heavy pressure upon
the division t, cannot speedily equalize itself in the remaining portion of the cylindrical
casing n, and the valve s, simultaneously with the slide valve q, is in consequence moved
in a backward direction, thereby uncovering the aperture p, through which air suddenly
entering the main pipe allows all the levers h, to drop, and all the brakes to be
simultaneously applied. Sudden shock when applying the brakes rapidly is prevented
by the air in the forward ends of the brake cylinders, which air not being able to
escape rapidly between the cylinder and the loose fitting covers, acts as an air
cushion.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is performed, 1 declare what I claim is:-
:―
The combination with the main air-pipe a, brake cylinder b, and weighted lever h,
of the regulating valve m, consisting of the several parts, and of the casing or shield z,
containing the filtering material, all substantially as and in combination hereinbefore
described and illustrated in the drawings hereunto annexed.
Dated this Twenty first day of June One thousand eight hundred and eighty
BROWNE & ATKINSON,
Applicant's Agents.