Improvements in Power Brakes.
Year: 1889

page_text: Date of Application. 14th May, 1889-Accepted, 6th July, 1889
COMPLETE SPECIFICATION.
[Communicated from abroad by THE LAURENCE RAILWAY BRAKE COMPANY, of 280,
Broadway, in the City, County, and State of New York, Manufacturers.]
Improvements in Power Brakes.
I WILLIAM WILLOT POPPLEWELL of 17 and 18 Southampton Buildings in the
County of Middlesex Engineer 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 that is to say :
This invention relates to improvements in that class of brakes for locomotives and
cars that are operated by means of a vacuum, compressed air, steam or any actuating
fluid.
The object of this invention is to provide a brake of this kind which is simple in
construction the parts of which can be readily applied or removed and which does not
subject the locomotive or car-frame or the wheels to any undue or injurious strains.
In the accompanying drawings Fig. 1 is a side view of a locomotivo provided with.
the improved brake, parts being broken out.
Fig. 2 is a rear view of the same, parts being in section and others omitted.
Fig. 3 is a rear view of the brake proper.
Fig. 4 is a vertical transverse sectional view on the line x, x Fig. 3.
Fig. 5 is a horizontal.sectional view on the line y, y of Fig. 4.
Fig. 6 is a rear view of the brake shoe.
Fig. 7 is a horizontal sectional view of the brake shoe on the line v, v Fig. 6.
Similar letters of reference indicate corresponding parts.
The brake cylinder or chamber. A has greater height than width and has its ends
rounded, this shape being given to the same so that the width of the cylinder or
chamber will not be much greater than the width of the wheel tire Z, and the greater
height is given for the purpose of having a sufficient area so as to produce the
necessary pressure. Said cylinder or chamber projects from a plate B which is bolted
or otherwise suitably fastened to the frame C of the locomotive or to a suitable frame
or piece on the car or truck. The cylinder or chamber A. is provided along its outer
edge with a wing D which is parallel with the plate B. The plate B and wing D are
united at the top and bottom by curved pieces 133 with which the said plato B and
wing D form a compartment B on that end or head of the cylinder or chamber
facing the rim of the wheel. Between said plate B and wing D that is in the
compartment B* the brake shoe E is mounted to swing in a manner that will be set
forth hereinafter. The cylinder or chamber A, is provided with a removeable head F,
which is bolted on the rear edge of the cylinder or chamber said head being provided
with a neck F forming a guide aperture for a neck G' projecting from both surfaces
to the piston G within the cylinder or chamber the front end of said neck G¹ being
A packing
guided in an aperture G in the front head of the cylinder or chamber A.
diaphragmn H preferably made of rubber and duck but which if desired may be made
of any other suitable material is provided with a central aperture through which the
neck G¹ of the piston can pass and along its edges is provided with a bead H'. The
edge of the diaphragm H is placed and firmly clamped between the rear edge of the
cylinder or chamber and the edge of the head F the packing plate resting on the rear
face of the piston and covering said entire rear surface.
The head F has a rib F on its inner surface along the edge and the edge of said rib
bears on the diaphragm H and presses it against the side of the cylinder or chainber
as shewn.
The edges of the piston are rounded or curved as shewn at G°. The diaphragm H
is so shaped and moulded as to have an approximately V-shaped groove H along its
rim, one side of said grooved part resting on the curved or rounded part G of the

page_text: piston. When the piston is back as far as possible the diaphragm H can rest on the
same without fold or wrinkle, and when the piston moves toward the front end of
the cylinder or chamber one side of the groove part of the diaphragmn leaves the
curved part of the piston and when the piston moves back again the diaphragm will
at once resume its snug position. All breaking cracking or folding of the diaphragm is
thus effectually prevented.
The piston G is provided on its inner face with an annular ridge I and the front
head of the cylinder or chamber A is provided on its inner surface with a like annular
ridge I. A heavy rubber packing ring J which is meniscus shaped in cross section
is passed around the neck G₁ of the piston G and its edges rest against the annular
ridges I, I as shewn the central portion of the inner surface of said rubber ring J
resting against the outer surface of the neck G¹. The shouldered packing ring Kis
placed in an annular groove in the neck F¹ of the head F and rests snugly against
the neck G¹ of the piston and forms a close and tight joint. The neck G¹ is provided
with an internal screw thread and into said, neck the screw block L is screwed
which is provided on its outer end with two jaws L' between which a lever L
is pivotted the pivotted end of said lever I being provided with a cam head L
and the opposite end being provided with the weight L³ for the purpose of
keeping said lever L in vertical position. The cam-end of the lever I is provided
with a stop-lug M³ that can abut against a ridge Mª uniting the jaws L. Between
the jaws La rubber cushion M is fastened by a rivet or otherwise on the outer end of
the block. L and bears against the cam end of the lever L² to prevent undue swinging
of the same. The block L is provided in its inner end with a tapering aperture N,
the inner end of which is rounded to receive the rounded end of a push bar Othe
opposite end of which passes through a transverse slot P in the front closed end of
the neck G and can bear against the brake shoe E, as shewn in Figs. 4 and 5.
The push bar O and the recess N in the block form a ball and socket joint. The
bar O can swing laterally as the shoe swings laterally with the wheel, and said bar
is free to move forward and back and is not positively connected either with the
piston or block L or the brake shoe.
On the front head of the cylinder or chamber A, two lugs are formed at the top
and bottom and through a pair of the same, a bolt Q is passed which is also passed
through an eye formed on one end of a link R from which the shoe E is suspended
by means of a pin S which also passes through two wings or lugs T on the back of
the shoe. As shown in Fig. 4 said wings T have apertures at the top and bottom to
permit of reversing the shoe. The bolt S is provided with a pin W which can swing
into a groove V formed on the back of the brake shoo said groove being provided
with notches V1 V through which said pin W can pass. When the brake shoe is to
be attached it is held from the front of the cylinder or chamber A as far as possible
and the bolt S passed through the apertures in the wings T and through the apertures
in the lower end of the link I the arm or pin W on said bolt being at right angles
to the front of the cylinder or chamber so that it can pass through the corresponding
netches V¹. When the shoe is then released it swings down against the front of the
cylinder or chamber and thereby presses the arm or pin W into the pocket or
groove V thus preventing withdrawing of the bolt S.
bolt S to become detached accidentally as the same can only be removed after swinging
It is thus impossible for the
outward the brake shoe turning the bolt S until the pin or arm W is at right angles
or approximately at right angles to the front of the cylinder or chamber and then
withdrawing said bolt. The cylinder or chamber A is provided at the top and bottom
with a neck a for attaching the pipe by means of which the air is exhausted and the
head F is provided with necks d to permit the air to enter when the air on the
opposite side of the piston is exbausted. In case the brake is to be operated by steam
or compressed air or carbonic acid gas or any other like fluid the pipes are connected
with the necks d.
The operation is as follows:-
When the air is exhausted from the space between the front of the cylinder or
chamber A and the piston G by means of the ejector Y or otherwien the atmasalani

page_text: ressure presses the piston G in the direction of the arrow r¹ and the push bar O
At the same time the rubber ring J is com-
resses the shoe E against the wheel.
ressed and the central part of itsținner surface pressed firmly against the outer surface
of the neck G thus forming an absolutely tight joint. When the vacuum is destroyed
he expansion of the ring J and the weight of the brake shoe move the piston in the
nverse direction of the arrow a¹. As the brake shoe wears off the push bar 0
must be moved outward correspondingly to the wearing of the shoe. To move the
push bar outward the screw block L is turned by means of the lever L² so as to
nove in the direction of the arrow ¹ in some cases there is not sufficient space
In such cases
to turn the block L when the lever L hangs down from the same.
the lever L is swung outward to be nearly in line with the axis of the block L,
it being locked in place by the action of the cushion spring M on the eccentric or
cam part . The stop M³ prevents swinging the handle lever L' beyond the centre.
After the block L has been adjusted the handle lever L' is swung down and its
weighted end L³ keeps it in a vertical position and prevents accidental unscrewing
of the block L. The cylinder or chamber A can easily be reversed that is it can
be applied on either side of the locomotive or either side of the wheel as it is
provided at the top and bottom with lugs Q for hanging the brake shoe, and
provided at the top and bottom with necks for attaching air-inlet or outlet pipes.
The improved brake is very simple in construction as it is composed of few parts
and those in turn are subjected to strains only which are the least injurious. The
diaphragm H which makes the piston absolutely airtight is not subjected to any
injurious strains as it rests snugly on the piston G.
.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
a fixed
1. In a power brake the combination with a cylinder or chamber having
and a removeable head of a piston in said cylinder a neck projecting from said piston
and guided in both heads of the cylinder and a push bar resting loosely on said
piston and against the brake shoe substantially as set forth.
2. In a power brake the combination with a cylinder or chamber of a piston having
a neck guided in both heads of the cylinder or chamber a block screwed into said
neck and a push bar held loosely in said neck and resting against the back of the
brake shoe substantially as set forth.
3. In a power brake the combination with a cylinder of a piston provided with a
neck guided in both heads of the cylinder or chamber, a screw block in said neck a
push bar resting loosely in said screw block and a handle lever pivotted to the outer
end of said screw block and having one end weighted substantially as set forth.
4. In a power brake the combination with a cylinder or chamber of a piston
provided with a neck guided in both beads of the cylinder or chamber a screw block
in said neck a weighted handle lever pivotted to the outer end of said screw block
and a spring acting on the pivotted end of said lever substantially as set forth.
5. In a power brake the combination with a cylinder or chamber having a neck
on one head a packing ring in said neck a piston in said cylinder or chamber provided
with a neck guided in both heads, a screw block in said piston neck and a push bar
held loosely in said screw block substantially as set forth.
6. In a power brake the combination with the cylinder or chamber of a piston
having a neck guided in said cylinder or chamber and a rubber ring surrounding
said neck and bearing against the piston and the inner surface of one cylinder head
substantially as set forth.
7. In a power brake the combination with a cylinder or chamber and a piston
having a neck of a rubber ring which is meniscus-shaped in cross section and
surrounds the neck on the piston between said piston and one head of the cylinder
substantially as set forth.
8. In a power brake the combination with a cylinder or chamber having a guide
opening on one head, an annular projection surrounding said opening on the inner

page_text: surface of said head a piston having a neck guided in said opening in the cylinder
head an annular projection on said piston and around said neck and a rubber ring
surrounding the piston neck the edges of said ring bearing against the above mentioned
annular projections substantially as set forth.
9. In a power brake the combination with a cylinder or chamber of a head
provided on its inner surface with a ridge along the edge and a diaphragm having its
edge clamped between the cylinder or chamber and its head, the edge of said ridge
pressing the diaphragm near the edge of the same against the inner side of the
cylinder or chamber substantially as set forth.
10. The combination with a cylinder or chamber of a piston and a diaphragm
clamped between the cylinder or chamber and one head of the same which diaphragm
rests on the piston and is moulded and shaped to have an approximately V-shaped
groove along the rim, substantially as set forth.
11. The combination with a brake shoe, of a link, a bolt passing through said link
and through wings on the shoe, said shoe being provided with a pocket or groove in
its back for receiving a pin or arm of said bolt substantially as set forth.
12. A brake shoe provided on its back with two wings forming a
receiving one end of a push-bar and a groove at the outer side of one wing which
recess for
groove serves to receive an arm on the bolt by which the brake shoe is pivotted to the
link substantially as set forth.
13. The combination with a cylinder or chamber having an opening in its front of
a piston provided with a neck passing through said opening one end of said neck
being provided with a transverse slot, a push har passed through said slot and a
screw-block in the piston neck which screw block has a recess for receiving the
inner end of the push bar substantially as set forth.
14. The combination with a locomotive frame of a cylinder or chamber secured
on said frame adjacent to the rim of the wheel the said cylinder or chamber being
flattened to have approximately the width of the wheel rim the long axis of said
cylinder or chamber being parallel with one of the diameters of the wheel, a piston
in said cylinder or chamber and a brake shoe connected with said piston and located
between the piston and the rim of the wheel substantially as set forth.
15. The combination with a locomotive frame of a cylinder or chamber secured on
the same, a piston in said cylinder or chamber, a brake shoe operated by said piston
and located between the piston and the rim of the wheel and a link pivotted to the
brake shoe and to the top of the cylinder or chamber containing the piston that
operates the shoe substantially as set forth.
16. The combination with a cylinder or chamber projecting from a plate and
having a wing on that side of the cylinder opposite the one connected with the plate
of a brake shoe between said plate and wing and a piston in the cylinder or chamber
acting on said brake-shoo substantially as set forth.
Dated this 14th day of May 1889
POPPLEWELL & Co.,
Agents for the Applicant.