Патент USA US2107403код для вставки
Feb. 8, 1938. A. J. WEATHERHEAD, JR - '2,107,403 y BRAKE CYLINDER ASSEMBLY AND METHOD OF MAKING SAME Filed Jan. 15, 1935 MINI/0 INE! - 2 sneets-sheet 1' Feb. 8, -1938. A. J. wyaATHERl-IEAD,l JR V2,107,403 BRAKE, CYLINDER ASSEMBLY AND METHOD OF MAKING SAME Filed Jan. l5, 1955 l 2 _Sheets-Sheet 2 (Ittvrnegs' 2,107,403 Patented Feb. 8, 1938 UNITED STATES PATIENTy OFFICE _ 2,101,403 BRAKE CYLINDER ASSEMBLY AND ME'rnoD OF MAKING SAME . 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 QI 5 ducting parts for conventional hydraulic vehicle _ moved from the brake; Figure 4 illustrates the members forming the cylinders of the device brakes. 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 ufacture resulted in heavy cylinders and the var 10 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 der. 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 der assembly which may be manufactured eco 25 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' 50 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 assembly. 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 ‘ claims: 2 2,107,403 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 10 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 22 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 65 se As forms shown no particularly part of fthe in present Figures Invention. 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 3 2,107,403 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 10 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 lar 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 required. y 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, (ii) 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 Cl 2,107,403 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 11 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 support. 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. ~ ALBERT J . WEATHERHEAD, JR.