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Патент USA US2107403

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Feb. 8, 1938.
Filed Jan. 15, 1935
2 sneets-sheet 1'
Feb. 8, -1938.
Filed Jan. l5, 1955
2 _Sheets-Sheet 2
Patented Feb. 8, 1938
Albert J. Weatherhead, Jr., Cleveland, Ohio, as
signor to The Weatherhead Company, Cleve
land, Ohio, a corporation of Ohio
Application January 15, 1935, Serial No. 1,908
12 Claims. (Cl. 253-1521)
sembly, parts of the mechanism being shown in
This invention relates to hydraulicbrake cylin
section; Figure 2 is a section through my brake
der assemblies and methods >of making the same,
and more particularly to the assembly of the
wheel cylinders and supporting and ñuid con
cylinder assembly taken on the line 2_2,4 Figure
l;- Figure 3 is a side elevation of my cylinder re
5 ducting parts for conventional hydraulic vehicle _ moved from the brake; Figure 4 illustrates the
members forming the cylinders of the device
It has heretofore been the general practice to shown in Figure 1 before assembly; Figure 5 il
make the wheel cylinders and associated parts lustrates the ñuid conducting saddle which is
adapted to be secured to the-cylinders; and Fig
from,a single iron casting. 'I'his method of man
ure 6 illustrates a step in the assembly of the 10l
ious manufacturing operations requires a great parts illustrated in Figures 3, 4 and 5.
Brieñy, I attain the objects of my invention
deal of machine work with consequent high cost.
Furthermore, the castings must be of especially and produce brake cylindersv having important
high quality to have the low porosity required to advantages over any heretofore known, by form
ing the cylinders themselves from short pieces of
15 withstand the high operating pressures without
seamless tubing or from drawn cups, and by se
leakage. 'I'he difficulty of the machining opera
tions has been recently increased by reason of curing the iiuid conducting and cylinder sup
the fact that in some types of modern hydraulic porting parts to the cylinder preferably by cop
are employed, thus requiring separate boring,
per brazing. In the preferred form of my inven
tion. as illustrated in the drawings, -two different
connection which is ñuid tight throughout sub
stantially the entirearea of contact between the
tight connection is'made between the arcuate
seat of the saddle and the cylinder throughout
inder assembly wherein the various parts making
assemble the various parts before the requiredA
brakes,'coaxial cylinders of - different diam'eters
reaming and-‘grinding operations for4 each cylin- ` diametersïare employed and I form the cylinders »
from tubing or cups of different diameters tele
It is among the objects of my invention to. scoped together,- lwhile the supporting and attach
ing means may be formed of bar stock. It is to
provide a light and strong hydraulic brake cylin
be understood, however, that cylinders of uni
form diameter may be employed, and that the
nomically with a minimum of machining opera
tions. It is also an object of my invention to supporting and attaching' means may be made by
provide a method of manufacturing such cylinder different methods.
>In applying my cylinders to hydraulic brakes '
assemblies. Another object of my invention is
of conventional design, I preferably make the 30
30 to provide a cylinder assembly wherein the ñuid fluid conducting and attaching means in the form
connecting and supportingmembers are formed
of a saddle having an arcuate seat secured to
separately from the cylinder or cylinders and se
cured to the cylinder or cylinders by means of a the outer surface of the brake cylinder. A ñuid
supporting member and the cylinders". Another ` substantially the entire area of contact, prefer- . object of my invention is' to provide. a brake cyl- ì ably by means of copper brazing. I prefer to
‘up the assembly can be `expeditiously and eco
nomically 'manufactured and assembled, Aand
wherein a minimum of machining operations is
required. Another object of my invention is to
providev a cylinder having a smooth.I internal
working surface particularly adapted for use with
steel pistons.- Another object is to provideA a
method of making such a Working surface.V
Further objects and advantages of my inven
tion will become apparent from Ithe following de
scription of a preferred form thereof, reference
being made‘to the accompanying drawings. The
essential characteristics are summarized in the'
passageways are drilled, and thereafter drill and
tap the necessary ñuid connections. It is'to be
understood. however,`that the steps hereinafter '
described maybe varied and the design ofthe
various parts may alsol be changed for diiïerent »
adaptations of mycylinder assembly tol diiîerent
typesv of brakes.
In order to provide asmooth working surface
in the interior of the cylinders, -I preferablycoat
the interior of the cylinders with copper before
The subsequent brazing operation,
~which is carried out in afurnace having a re
ducing atmosphere, results in the production of
a thinV ñlm of copper iron alloy on the interior
In the drawings, Figure 1 is a fragmentary - surfaces of the cylinders which needs only to be
side elevation -of a hydraulic brake of the con- , burnished to produce an excellent bearing sur
face for the pistons. The copper alloy surface is 55,
55 ventional type embodying my :brake cylinder as
particularly desirable when the cylinder is to be
used in conjunction with steel pistons.
sisting the operation of assembling the pistons
and rubber cups Within the cylinders, while the
Referring in detail to the drawings, in Figures flared outer surface provides a means of retain
1 and 2, I have illustrated an adaptation of my ing the rubber dust caps 38 and 39.
invention to a type of hydraulic brake now in wide
The saddle member 21 may be formed by cut
use. 'I‘he brake which is of conventional construc
ting oil’ bar stock drawn to have substantially
tion may have brake shoes I 0 and Illa pivoted the cross sectional shape illustrated in Figure 4
at their lower ends to anchor pins (not shown) « and having an arcuate surface 38 adapted to en
which are in turn secured to a backing plate I2
gage the outer surface of the larger cylinder I5
10 suitably mounted on the wheel axle. 'I'he >brake and a portion4 39 which is subsequently ma
shoes may be swung outwardly into engagement chined to cylindrical form and threaded to form
with the brake drum by means of fluid pressure the projection 26 and the shoulder 29.
within the communicating cylinders I4 and I5
To assemble the various parts into a strong
and acting on pistons I6 and I1. To prevent unitary assembly, I preferably coat each of the
15 leakage of the fluid, the pistons are provided
parts with a thin coating of copper, either by
with the usual rubber cups I8 and I9, and the electroplating or by dipping or spraying with a
pistons actuate the brake shoes through sult
lacquer solution containing copper> powder in >
able connecting rods 20 and 2|. Upon release of suspension. Thereafter the cylinders I4 and I5
the iluid pressure, the shoes are moved out of are telescoped together to the required amount
20 engagement with the drum by retractor springs
and the saddle member 21 placed in contact with 20
the outer surface oi' the cylinder I5. Preferably,
The brake cylinders are supported on the back
the assembly is supported as shown in Figure 6
ing plate I2 by means of a nut 25 threaded on by means of a blockl 55 of carbon or other re
the projection 26 of the saddle member 21 which fractory material which engages the supporting
extends through the opening 33 in the backing saddle 21, on which the cylindrical members 25
plate, the shoulders 29 and fiat surfaces 30 be
rest. The ends of the cylinders maybe addi
ing drawn tightly against the backing plate. The
saddle member 21 is preferably copper brazed to
the outer surface of the cylinder I5 and is drilled
tionally supported by smaller carbon blocks
56, if desired. 'I'he assembled parts‘are then
placed in a furnace having'an atmosphere of
and tapped through the projection 26 to provide ` hydrogen or other reducing gas, and heated to 30
a passageway 28 for fluid under pressure which a temperature of approximately 2150“ F. At this
may be 'supplied through a hose and a suitable temperature, the copper in the coating of the
connection fitting (not shown). At the top of various parts becomes iiuid, and in the reducing
the cylinder, another opening 3| is drilled atmosphere of the furnace forms an alloy with
through the saddle member and the walls of the underlying steel surface. The copper is
the cylinder to provide a vent for removing all air drawn by capillary attraction into all of the .
from the system. The passageway 3l may be spaces between the various parts and, as is .well
'closed by a suitable plug 32 which extends known in the art of copper brazing, results in a '
through the opening 34 in the backing plate and
copper bond between the assembled parts which
40 assists ~in retaining the cylinder on the plate.
is substantially as’strong asvthe parent metal
It will be noted that cylinder _I5 has a larger itself.
internal diameter than cylinder I4. In some
The copper penetrates the pores of the steel,
types Aof brakes, this ‘is done in order to equalize
the wear on brake shoes III and Ina. In case the forming an alloy therewith, and thus the interior
45 normal forward rotation of the wheel to which surfaces of the cylinders are provided with a 45
the brake is attached is in the direction shown layer of copper and copper iron alloy, which
by the arrow in Figure 1, the wrapping action of is especially smooth and forms an excellent bear
the brake shoe Ill under ordinary circumstances ing surface for the pistons. Sufllcient copper is
would rcause it to bear harder against the drum supplied to take up any inequalities between the
I3 than the brake shoe Illa if the expanding for'ce arcuate surface 38 of the-` saddle member and ,_
on both shoes were equal. To counteract this the exterior surface of the cylinder I5, so that '
the-joint between the saddle member and‘ cylin
tendency and equalize the wear and braking ef
der is leak proof through substantially the en
fort of the two shoes, the cylinder I5 which actu
tire area, and'likewise a leakage proof joint- is
ates the shoe Ila has a slightly larger cross sec
tional area than the cylinder I4 so that `a greater _formed between the exterior of cylinder I4 and :1 Ll
expanding force will be exerted on the shoe Illa, the interior of cylinder I 5. "I'hus by the sín
gle brazing operation, the various parts of the
thusseompensating for the self-energizing ef
fect of the shoe III in the forward rotation of the assembly are strongly secured together, leak
proof joints are formed'where needed, and an ex
brake. In another type of brake the arrange
ment is reversed in order to exert the greater cellent bearing surface is provided on the in 60
expanding force on the; forward shoe and thus. teriors of the cylinder.
At high temperatures in the furnace,- the steel »
reduce the pressure which must be applied to the
pedal. 'I'he general design of the brake 'will not is apt to become somewhat soft and if not prop
be discussed in detail herein, as the brake` per er__ly supported, might possibly be distorted by its
se As
no particularly
part of fthe in
4 and 5, the own weight. I have found, however,.that the
diiliculties due to the Alikelihood of distortion are
cylinders I4 and I6 and the saddle member 21 eliminated by supporting the assembled parts
are all formed separately. The_cylinders I4 and I5 in the lm_anner illustrated in Figure 6. It will be
may comprise short sections of seamless tubing noted -that by this method of supporting, the
or preferably drawn cups having the closed ends tubular cylinders are supported throughout near 70
of the cups cut of! after the drawing operation. ly 180 degrees by the .heavier steel member, while
The cylinders telescope together as indicated at further support is given by the double thiol:
35 in Figures 1` and 3,`and the ends of the cyl A ness òf metal in this zone. Likewise the flared
inders are flared or bell mouthed slightly as at ends 36 and 31 of the cylinders give additional
75 36 and 31, the flare of the internal surface as
strength and rigidity at these points, and as a 75
In the foregoing specification, I have described '
result no measurable distortion takes places dur
a preferred form of my brake cylinder assembly
ing the heating operation.
As previously stated, I prefer to carry out the . and methods of makingI the same. Modifications
drilling and tapping operations after assembly of in both the assembly and the method will be
apparent to those skilled in the art. It is there
fore to be understood that my patent is not
and 3| in the saddle member and the openings in ' limited to the embodiment described herein or
the depending portions 49 and bosses 50 of the ' in any manner other than by the appended claims
supporting plate drilled and tapped. This mode when given -the range of equivalents to which my
all ' of the parts.
'I'he assembled unit may be
mounted in a suitable jig, and the passageways 29
of operation has important advantages, particu
patent may be entitled.
larly in connection with the openings 28 and il.`
The passageway 3i must be drilled tangentially l
through the wall of the cylinder l5 in order that
all air may beA removed from the cylinders
through the vent. Such a tangential drilling op
eration on an ordinary tube requiresV a special
support for the tool, whereas by carrying out the
drilling operation after the assembly, the saddle
I claim:
i. The combination of a tubular brake cylinder ' '
formed of sheet stock having open outwardly
flared ends with a fluid conducting and anchoring
member having a surface conforming to the side
wall of the tubular member and bonded thereto
with a permanent fluid tigl metallic bond»
throughout substantially the w ole of the area of
contact therebetween, and having a passageway
member itself forms the necessary- support. Fur
therein extending through the wall of said tubu 20
thermore, by drilling the passageways after as
member within the said fluid tight bonded
sembly, proper registration of the openings in the
various parts is assured and the preliminary area between said members, and means asso
steps of the assembly operation can be carried out ~ ciated with said fluid conducting and anchoring
member for securing it to an external* support.
more expeditiously.
2. The combination of a tubular brake cylinder
The drawn cups which preferably comprise the
cylinders I4 and I5 may be formed with great formed. of sheet stock having open outwardly
accuracy so that the interior surface of the cyl~ ñared ends and a stepped mid-portion with a
fluid connecting and anchoring member having
inders can be finished Within the necessary toler
ances merely by burnishing the interior copper an arcuate wall conforming with the side wall 30
of the tubular member and bonded thereto ad
and copper alloy surfaces. The simple burnish
ing operation producesy a smooth copper alloy jacent the stepped mid-portion thereof with
` surface and no further roaming or grinding is
It will be obvious to those skilled in the art that
the various steps in the production of my cylinder
assembly can be carried out in diñerent orders
and in different manners. For example, the ma..
chining operations or part of them can-be carried
out before the brazing operation. If desired, the
a permanent fluid tight metallic bond throughout
substantially the whole of the arcuate area of
contact therebetween and having passageways
therein extending through the wall of said tubu- ~
lar member within the `said fluid tight bonded
area between said members, and means asso
ciated with said last named member for securing
it to an external support.
3. The method of> making a duid pressure 40
copper can be supplied by some copper pellets or
brake cylinder which comprises telescoping two
wires disposed adjacent the surfacesto be joined ,v tubular
steel parts together, positioning a saddle
` together instead of by coating the entire surfaces
like steel member over the outer of said tubular
of the various parts. However, if the machining
operations are carriedv out first,- care must be
taken to see `that copper doesnot flow into the
threads of the tap holes, for it is very dii'licuit to
retap the holes after copper hasbeen deposited in
the threads. It is perfectly satisfactory, how
ever, to first drill the holes, then carry out the
brazing operation, and thereafter tap the threads
parts where the tubular parts overlap, copper
brazing the three parts together to form a fluid 45~
tight connection throughout the areas of contact
and thereafter forming passageways through said
member and tubular parts in the zone of the
copper brazed joints therebetween.
4. A method of making a i'luid pressure brake 50
cylinder of a steel cylindrical tubular part and
in the holes'. While I prefer to coat the interior a steel anchoring and connecting part having a
ofthe cylinders with copper as well as the ex
surface adapted substantially-tocoincide with a
terior, because the interior provides an excellent Wall of the tubular part, which comprises copper
fbearing surface while the exterior surface pro
brazing said part to said member, supplying suffi
vides a corrosive resisting surface, nevertheless» cient copper. in the brazing operation to cause at
the copper coatings can befomitted, without de
least part of the interior surface of said part to
parting from the teachings of my invention.
'From' the foregoing description, it will be seen
that because of the'great strength of the welded
joints and their leak proof qualities, I have pro
duced .an extremely strong brake cylinder assem-l
bly. My cylinder assembly is light as comparedA
. be coated with copper, forming ñuid passageways
through said member into said- part'within the
area~of copperv brazed connection therebetween,
andv finishing the’interior copper surface of the
tubular part to form a smooth working wall for .
a piston‘to be operated therein.
5. A method of making* fluid pressure brake
with presenttypes of assemblies because of the ,
_greater strength of _ the materials employed as cylinders which includes the steps of shaping the
open end of a‘ferrous cylinder to provide a periph
eral overhanging cap retaining portion, forming
sembly operations and 'machining can be carried a ferrous iiuid conducting part having- an arcuate
out~expeditiously-and economically.:` My method surface adapted to conform to the outer surface
of said cylinder, supporting said fluid conducting
produces cylinders having excellent interior sur
faces for engagement with the pistons which op- _ 'part on a refractory support and supporting said
. erate therein, and a cylinder assembly made ac'--. cylinder on .the arcuate surface of said fluid con
_cording to my invention may be adapted to vari " ducting part, supplying non-ferrous bonding
ous types of brakes; as well as other uses wherein metaltothe area of contact of said part and said
cylinder and heating the assembled parts to a
75 iluld pressures are involved.
compared Lto- cast,irqn. Y Bycmy method, many
machining opërationsï‘areieliminatedl and the as
temperature suillcient to form an alloy bond be
tweensaid part and said cylinder, the arcuate sur
face of said fluid conducting part supporting said
cylinder to assist in preventing the deformation
of said cylinder during the heating thereof.
6. A method of making fluid pressure brake
cylinders comprising forming a ferrous cylinder
having an open end, flaring the open end portion
of the cylinder, forming a ferrous fluid connec
tion member, assembling the member and the
cylinder, supplying copper to the contiguous sur
faces of the member and the cylinder, and there
after heating the assembly to a sufllciently high
temperature to cause the formationof an alloy
bond between the member and the cylinder, the
flared end of the cylinder assisting in preventing
the deformation of said cylinder during the heat
ing thereof.
7. That method of making a fluid pressure
brake cylinder which comprises forming a pair of
tubular steel cylinders of different diameters,
telescoping said cylinders together throughouta
portion of their length, forming a fluid inlet mem
ber with an arcuate surface adapted to engage an
i.. LA
exterior cylindrical surface of the larger of said
two cylinders and thereafter securing said two cyl
inders and said fluid inlet member together.
8. That method of making a iluid pressure
brake cylinder which comprises forming a pair of
bond arranged between said members and means
associated with said fluid conducting and anchor
ing member for securing the same to an external
l0. The combination of a tubular ferrous metal
cylinder having an open end provided with a
peripheral overhanging dust cap retaining .ilange
and a' stepped mid portion with a fluid connecting
and anchoring member having an arcuate wall
conforming to the> side wall of the tubular mem
ber and bonded thereto adjacent a stepped mid
portion thereof with a permanent fluid tight
metallic bond throughout substantially the whole
of the arcuate area of contact therebetween and
having passageways therein extending through
the ywall of said tubular member within the said
fluid tight bonded area between said members, and
means associated with said last named member for
securing the same' to an external support.
11. A method of making a -fluid pressure brake
cylinder of an apertured steel cylindrical tubu
lar part and an apertured steel anchoring and con
necting part having a surface adapted substan
tially» to coincide with a wall of the tubular part
which comprises copper brazing said part to said
member with the apertures of said part and
said member in alignment to form- a brake fluid
conduit, supplying sufllcient copper in the brazing
operation to cause at least a part of the interior
tubular steel cylinders of different diameters,
telescoping said cylinders together throughout a
surface of said part to be coated with copper, and
finishing the interior copper surface of the tubu
portion of their lengths, forming a fluid inlet mem
-lar part to form a smooth working wall for a’pis
ber with an arcuate surface adapted to engage an
ton to be operated therein.
exterior cylindrical surface of the larger of saidV
12. That method of making fluid~ pressure brake
two cylinders and thereafter securing said twocylinders and said fluid inlet member together by
a single copper brazing operation.
9. The combination o_f a tubular brake cyl
inder formed of sheet metal vstock having the open
40 end thereof provided with a peripheral over
hanging cap retaining flange, a fluid conducting
and anchoring member having a surface conform
ing to 'the side wall of the tubular member and
bonded thereat with a permanent fluid tight>
:s Li metallic bond throughout substantially the whole
of the area of contact therebetween and having a
passageway therein extending through the wall
of said tubular member within the said fluid tight
cylinders which comprises forming a cylindrical
blank of steel stock, shaping a ferrous supporting
fluid inlet block to embrace and intimately con-A
tact said blank, temporarily securing said block
and blank in assembled relation and applying a
quantity of copper to said assembly sumcient to
copper braze the parts'in assembled relation and
form a copper alloy lining for said blank, there
after heating the assembly to copper braze the
parts together and form said lining and burnishlng
and polishing the copper ,alloy lining of the cy
lindrical blank.
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