Improvements in Power Brakes for Locomotives.
Year: 1890

page_text: Date of Application, 29th July, 1890-Accepted, 27th Sept., 1890
COMPLETE SPECIFICATION.
Improvements in Power Brakes for Locomotives.
I HENRY BIRKBECK of 34 Southampton Buildings Chancery Lane, London, W.C.
Patent Agent (a communication to me from abroad by The Lawrence Railway Brake
Company of New York City, in the County and State of New York United States of
America) 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 invention relates to improvements in power brakes for locomotives and the
object of the invention is to provide a brake in which the brake shoes are applied to
the rims of the wheels in such a manner that the wheels are not interfered with in
their lateral or vertical movements caused by irregularities in the track and so that
the pressure of the brake shoes on the wheels does not act injuriously on the bearings
or journal boxes of the axles.
The improved brake can be applied on all kinds of locomotives whether the wheels
on the same are close together or at a distance from each other.
In the accompanying drawings Figure 1 is a side view of a locomotive engine
provided with several constructions of the improved locomotive brake.
Figure 2 is a vertical longitudinal sectional view of that construction of the brake
adapted for location between two wheels that are close to each other.
Figure 3 is a vertical transverse sectional view of the same on the line 3-3 of
Figure 2.
Figure 4 is a vertical transverse sectional view of that construction of the brake
adapted for location between wheels that are a greater distance apart.
Figure 5 is a vertical longitudinal sectional view of that construction of the brake
as adapted for the end wheels.
Figure 6 is a transverse sectional view on the line 6-6 of Figure 5 and
Figure 7 is a longitudinal vertical sectional view of a modified construction of the
brake for wheels that are a greater distance apart.
Similar letters of reference indicate corresponding parts.
In many engines the driving wheels are so located that their rims are but a few
inches apart thus rendering it extremely difficult to apply a brake mechanism
between said wheels. In the improved brake the cylinder or chamber A Figures 1, 2
and 3 which is made oblong that is to say its length is greater than its width is
arranged between the driving wheels a but above the planes of the axle b. Said
cylinder or chamber A contains a diaphragm B resting against and secured to the
under side of a piston plate from which the stem D projects downward said stem
having a slot D. The upper brake shoes F are pivoted to the cylinder or chamber A
by pivots F in such a manner as to be adjacent to the wheel rimis and below their
pivots they rest against the heads of pins G placed into tubular rubber cushion
springs H resting in suitable sockets in the side parts of the cylinder or chamber A.
Said cushion springs H and pins G prevent the upper ends of the shoes F from
tilting downward sufficiently to rest upon the wheel rims when the brakes are not
applied and thus serve to hold the brake shoes at all times in proper position in
relation to the wheel rims. In the cylinder or chamber A two levers J are arranged
one at each side the outer ends of the levers J being pivoted by pivots J¹ to the
cylinder or chamber which pivots J₁ are above and slightly to one side of the
pivots F by which the brake shoes F are pivoted to the cylinder or chamber and
the inner ends of said levers J are bent to form toes J' which pass into the slot D' of
the stem D and rest on the bottom of said slot. To each lever J the upper end of a
link K is pivoted a short distance from the turning point or pivot J of said lever J
the lower ends of said links K being pivoted to lugs E² of a tubular pull rod E

page_text: passing up through the bottom neck A² of the cylinder or chamber A. The lower
part of said tubular pull rod E is threaded internally and into the same the upper
end of the pull rod E¹ is screwed which supports the lower brake shoes in a manner
that will be described hereinafter. A packing ring L is placed into the bottom
neck A2 of the cylinder or chamber A and against the inner edge of the same the
tubular pull rod E rests which ring serves to prevent undue rattling. The head A'
of the cylinder or chainber A between which head and the cylinder or chamber the
diaphragm B is clamped securely is provided on its top with a suitable lug M to
which a bolt N is pivoted said bolt passing up through the bottom aperture of a box
shaped hanger O securely bolted to the frame or running board d of the locomotive.
On the upper end of said bolt N a nut P is screwed having its lower end formed cup
shaped and between the bottom of said box and the cup shaped lower end of said
nut Pa powerful helical spring R surrounds the bolt N. The entire brake device is
thus supported by means of the bolt N nut P and spring R from the box or
bracket O. The lower brake shoes Q which are arranged between the wheel rims
and below the planes of the axles are pivoted to the opposite ends of a block S
resting on a sleeve T that is bolted or riveted to the lower end of the rod E' and is
provided at its lower end with a cross piece or hand wheel T.
In said block S cushion springs Hare arranged like those described above for
supporting the lower parts of the shoes and thus prevent the shoes from coming in
contact with the rims of the wheels when the brake is not applied. A flexible
pipe V connects the head A¹ of the cylinder A with the vacuum pipe Vi for the
purpose of exhausting the air said pipe 'V' being connected with the ejector for other
vacuum apparatus in the cab g.
The operation is as follows:-
When the air is exhausted from the space between the piston C and the head A of
the cylinder or chamber A the exterior pressure of the air forces the piston ()
upward whereby the slotted stem D₁ is also forced upward and in turn pulls up the
toe ends of the levers J. Thereby the links K are pulled upward and in turn pull
up the tubular pull rod E and the rod E¹. Thereby the block S is raised and the
shoes pressed against the wheel rims said shoes Q forming an abutment. As the
free ends of the levers J can only be pulled up until the shoes Q rest firmly against
the rims of the wheels it follows that the pivot points J' of the levers J within the
cylinder or chamber A must move downward and with them the entire chamber A.
moves downward whereby the upper brake shoes I are pressed against the wheels.
By the downward movement of the brake cylinder or chamber A the spring Ris
compressed more or less.
When the vacuum is destroyed the piston moves downward the cylinder A
moves upward the rod E¹ is moved downward and all the brake shoes are released.
By turning the nut P the cylinder or chamber A can be so adjusted as to hold the
upper brake shoes F the desired distance from the wheel rims and by turning the
rod E the same is screwed a greater or less distance into the tubular rod E and
thereby the lower brake shoes Q are adjusted to be in proper position in relation to
the wheel rims. As the cylinder or chamber A can swing on the bolt N and as the
pull rod E is connected with the cylinder or chamber A by pivot links and levers it is
evident that even when the brake shoes are firmly applied on the wheels said wheels
can move up and down or laterally without causing any undue strain on the working
parts of the brake such up and down movements being caused by irregularities in
the track which are frequently quite considerable.
In case the wheels are separated a greater distance from each other as shown for
example in Figure 1 between the first and second wheels (from the front of the
locomotive) one of the constructions shown in Figures 4 and 7 is used.
In the construction shown in Figure 4 the brake shoes K2 are connected by links l
with the cylinder or chamber A which is constructed and hung in the manner
previously described. The shoes are also connected by links n with a bracket o on
the locomotive frame u. The pull rod is screwed into the downwardly projecting
piston stem D and is provided at its lower end with a box D³. Levers r pivoted

page_text: to que miks n have their free ends placed into the box D³ and rested on the bottom of
the same.
When the air is exhausted from the cylinder or chamber A the air pressure forces
the piston upward whereby the rod p and the box D³ are pulled upward and thereby
the shoes K are pressed against the wheel rims and form an abutment.
As now the piston cannot move upward any further the chamber or cylinder A
moves downward under the action of the atmospheric pressure and thereby by means
of the links assists in pressing the shoes K against the wheel rims.
When the vacuum is destroyed the spring R pulls the cylinder or chamber upward
and the rod p is moved downward.
In Figure 7 a brake is shown which is also used where the wheels are separated
a greater distance. The cylinder a is cast integral with its head a which is provided
with a central neck a into which the air exhaust tube is screwed the lower end
of said tube projecting a short distance from the under side of the head a and said
projecting part being screw threaded. The upper part of the tube projects through
a suitable aperture in the running board or frame of the locomotive and is surrounded
above said running board d by a helical spring d the lower end of which rests on a
suitable socket plate d of the running board d the upper end of the spring resting
against the under side of the nut, e screwed on the upper end of the tube 65. Said
nute has a longitudinal bore and is provided at its upper end with a neck e on
which a tube can be applied for connecting the nut e and tube 5 with the pipe
connected with the air ejector or said tube 66 can be connected in the manner
described (or any other suitable manner) with a chamber containing compressed
air or with a steam pipe or with pipes for conducting any other motive fluid.
Within the cylinder a a tubular diaphragm or packing which is made of india
rubber or analogous or suitable material is placed which is provided at its upper end
with an inwardly projecting flange f and at its lower end with an outwardly pro-
jecting flange which latter is clamped between the bottom edge of the cylinder
and the bottom head g of the cylinder. The upper flange f of the tubular packing
diaphragm is clamped between the underside of the top plate a and a circular
plate that is screwed on the lower threaded and projecting end of the tube b³.
The tubular diaphragm is thus held securely at the top and bottom and its outer
cylindrical surface is held a short distance from the inner walls of the cylinder «³.
The piston which has a diameter slightly greater than the inner diameter of the
tubular diaphragm is provided on its edge with a downwardly projecting flange
the outer face of which is slightly rounded. The piston rod is connected with the
piston and projects through the central neck g of the bottom head of the cylinder
and is guided at its lower end by a suitable guide piece on the frame of the
locomotive. On suitable lugs on the side of the neck g of the bottom head g³ the
two links are pivoted the opposite ends of which are pivoted to the top wings nº
of two casings n also provided with bottom wings n to which the two links are
pivoted the opposite ends of said links of being pivoted respectively to the opposite
lugs of a collar p fixed on the piston rod near the lower end of the same.
The casing n contains a screw g³ provided near its outer end with a flange 2 resting
against a shoulder on the inner surface of the casing at the outer end of the same
and beyond said flange each screw is provided with a stem which projects from
an aperture in the outer end of the casing n' and on said stem a head is fixed
which is used for turning the screw 7. Each screw 9' is screwed into the internal
screw threaded bore of a sleeve u pivoted to the brake shoe to at or near the centre
of the same.
The shoes are suspended by means of links in the usual
manner.
is
The operation is as follows
When the air is exhausted from the upper part of the cylinder as the piston
forced upward by the pressure of the exterior air and the outer ends of the links os
are forced from each other in the manner of a toggle lever and. the break shoes are
pressed against the rims of the wheels. As the air is still further exhausted from

page_text: the top part of the cylinder and as the piston cannot be forced up any further the
entire cylinder moves downward (under the action of the air) and the outer ends of
the links are forced from each other in the same manner as in a toggle lever and
thus more pressure is exerted on the shoes. The links and o³ do not act directly
on the shoe but press the casing n³ laterally. Said casing presses the screws 7
laterally and as the screws are in the sleeves and said screws are pivoted to the.
brake shoes it follows that the shoes are pressed against the wheel rims. As the brake
shoes and the wheel rims wear off the screws are turned so as to move the
sleeves toward the shoes-that is to say-the effective length of the sleeve is
increased accordingly as the shoes wear off. When the air is exhausted from the
cylinder the pressure of the air in the narrow space between the outer surface of the
tubular diaphragm and the inner wheels of the cylinder forces the said tubular
diaphragm inward and against the edges of the piston thereby packing the piston
and preventing leakage.
The above described constructions are adapted to be located between two wheels
but it is also necessary to provide a brake shoe at the outer edge of both the
front and rear wheels which brakes are constructed as shown in Figures 5 and 6.
The cylinder or chamber A is bolted to the frame u of the locomotive (Figure 1)
and contains a diaphragm and piston of the usual construction which need not be
described here and from said piston a rod projects through an aperture in the
head of the cylinder or chamber A. Said rod c is connected by a pivoted link d
with the upper end of a lever et pivoted at f to the brake shoe g which is located
adjacent to the wheel rim. A greater or less distance above the pivot f connecting
the lever e¹ with the brake shoe the outer end of a fulcrum bar 4* is pivoted to the
lever which fulcrum bar is provided with a longitudinally screw threaded bore
for receiving the threaded stem provided with a rounded shoulder or collar and
with an extension m². The fulcrum bar is inserted into a recess n of a block n'
projecting from a bracket p securely bolted to the frame or side plate of the
locomotive which recess n is of such size transversely that the fulcrum bar can
swing laterally in the same as shown in Figure 6. To prevent the fulcrum bar h
from turning it is made of such shape that its sides rest against the top and bottom
of the recess n³. The inner end of the recess 8 is rounded as at n° to form a seat
for the rounded collar or shoulder of the stem and at the inner end of said
recess an aperture is formed in the block n through which aperture the
extension m of the stem ** passes. A helical spring is placed into the recess q
in the rear end of the block n' and hears against a cross piece or hand wheel t
fastened on the outer end of the extension m. The spring holds the rounded
shoulder against the rounded inner end of the recess quite snugly thereby
preventing undue rattling of the parts. A helical spring is interposed between the
back of the brake shoe g and a set screw in the lower end of the lever et for the
purpose of maintaining the equilibrium of the shoe.
The operation is as follows:-
Either by exhausting the air from the cylinder A or by forcing compressed air
or steam or any other suitable fluid into said cylinder the rod is moved in the
direction indicated by the arrow a Figure 5 whereby the brake shoe is moved in the
inverse direction of the arrow a and pressed against the wheel rim the pivot con-
necting the fulcrum bar and lever et being the fulcrum. In case the shoe g*
wears off the same must be adjusted so as to be at all times the proper distance from
the wheel rim. To so adjust the screw the hand wheel or cross piece on the rear
end of the extension m of the stem is turned. As the fulcrum bar cannot
turn on account of its shape and the shape of the recess no said fulcrum bar must
necessarily travel on the stem k in the direction toward the wheel rim and thereby
the shoe is adjusted the proper distance from the wheel rim. Any wear of the shoe
can thus be taken up so that the shoe will at all times be in the proper position in
relation to the rim of the wheel. As the rounded collar rests against the rounded
inner end of the recess n in the block n' and as said recess n is wider than the

page_text: fulcrum bar said fulcrum bar can swing laterally in the recess and thus can move
with the lever et shoe o' and the wheel rim when the wheel vibrates laterally as
constantly occurs on locomotive wheels.
It is evident that in place of operating the above described brake mechanisms by
vacuum they can be operated by compressed air only slight changes being necessary
in the construction to adapt them for being operated by compressed air or any other
suitable motive fluid.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
:―
1. A brake cylinder or chamber mounted on a locomotive frame between the wheels
to move vertically and a movable piston in said cylinder or chamber substantially as
set forth.
2. The combination with a locomotive frame of a brake cylinder or chamber held
by a spring hanger or support between the wheels substantially as set forth.
3. The combination with a locomotive frame of a brake cylinder or chamber
mounted vertically movable between the wheels brake shoes connected with and
operated by said cylinder or chamber and a movable piston in said cylinder or
chamber connected with brake shoes substantially as set forth.
4. The combination with a locomotive frame of a cylinder, or chamber mounted
vertically movable between two wheels of a piston in said cylinder and an operating
rod operated from said piston and passing down between the two wheels substantially
as set forth.
5. The combination with a locomotive frame of a cylinder or chamber mounted to
move vertically of a piston in said cylinder brake shoes on the cylinder and another
set of brake shoes connected with the piston substantially as set forth.
6. The combination with a locomotive frame of a cylinder or chamber mounted
between the wheels of a piston in said cylinder or chamber provided with an exten-
sion or piston rod levers pivoted on the cylinder or chamber and engaging said piston
rod or extension a pull rod links connecting the pull rod with the said levers and
brake shoes at the lower end of said pull rod and operated by the same substantially
as set forth.
7. The combination with a locomotive frame of a cylinder or chamber mounted
between the wheels to move vertically of a piston in said cylinder or chamber and
provided with an extension or piston levers pivoted in said cylinder or chamber a
pull rod which is adjustable in length and connected with the said levers in the
chamber brake shoes applied on said cylinder or chamber and brake shoes supported
by the lower end of the pull rod substantially as set forth.
8. The combination with a vehicle frame of a cylinder or chamber a hanger or
box on the vehicle frame a screw bolt pivoted to the cylinder or chamber and passed
into the box a nut on said bolt a spring on which the nut rests and brake shoes
operated from the cylinder substantially as set forth.
9. In a power brake for vehicles a power cylinder mounted movably on the frame
or body of the vehicle brake shoes operated from said cylinder or chamber and a
movable piston in said chamber or cylinder and also operating brake shoes com-
bined substantially as set forth.
10. In a power brake the combination with a brake shoe a cylinder or chamber
and a piston rod projecting from the same of a fulcrum bar on the vehicle frame a
lever pivoted to said fnlerum bar and having its turning point on the same the longer
end of said lever being connected with the piston rod said lever being also connected
with the brake shoe substantially as set forth.
11. The combination with a cylinder or chamber a piston rod and a brake shoe of
a lever connected with the piston rod and pivoted to the shoe a block on the locomo-
tive frame and a fulcrum bar pivoted to the above mentioned lever and located
adjustably within said block substantially as set forth.
12. The combination with a cylinder or chamber piston rod and brake shoe of a

page_text: lever connected with said piston rod and pivoted to the brake shoe a block held on
the locomotive frame a fulcrum bar located in said block and pivoted to the above
mentioned lever and a screw for moving said fulcrum bar toward or from the wheel
rim substantially as set forth.
13. The combination with a cylinder or chamber piston rod and brake shoe of a
lever pivoted to the piston rod and pivoted to the brake shoe a block projecting from
the locomotive frame and having a recess the inner end of which is rounded a screw
thread stem having a rounded shoulder resting against the rounded inner end of
said recess and a fulcrum bar screwed on said threaded stem and connected with the
above mentioned lever that is pivoted on the brake shoc substantially as set forth.
14. In a brake the combination with a cylinder mounted to move toward a
movable piston in the same of a piston rod on said piston brake shoes suitably
suspended and hung sleeves connected with the brake shoes casings surrounding said
sleeves links connecting said casings with the cylinder and other links connecting the
said casings with the piston rod substantially as set forth.
15. The combination with a cylinder piston and a piston rod said cylinder being
mounted to move toward its movable piston of brake shoes suitably suspended and
hung sleeves pivoted to the brake shoes screws screwed into said sleeves casings
surrounding the sleeves and resting against the screws and links connecting said
casings with the cylinder and other links connecting said casings with the piston rod
substantially as set forth.
16. The combination with a cylinder piston and piston rod of brake shoes suitably
suspended and hung sleeves pivoted to the brake shoes screws screwed into said sleeves
and provided at their outer ends with flanges casings surrounding the sleeves and
having their outer ends rested against the flanges of the screws heads for turning
said screws links connecting said casings with the cylinder and other links connecting
the casings with the piston rod substantially as set forth.
17. The combination with a cylinder of a cylindrical diaphragm held a short
distance from the walls of said cylinder and a piston in said cylinder substantially
as set forth.
18. The combination with a cylinder of a tubular diaphragm in the same and a
piston having a rounded edge substantially as set forth.
19. The combination with a cylinder of a tubular diaphragm in the same top and
bottom flanges on said diaphragm means for clamping the flanges of the diaphragm
and a piston in the cylinder substantially as set forth.
20. The combination with a cylinder of a tubular diaphragm provided with
flanges resting against the top of the cylinder a plate resting against said flanges
and means for pressing said plate against the flanges substantially as set forth.
Dated this 29th day of July 1890.
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Patentee.