MXPA98004497A - Complete shoe - Google Patents

Abstract

The present invention relates to a composition brake shoe for use in a rail freight or freight vehicle for reconditioning the running surface of the wheel of the rail freight vehicle during a normal braking application in said vehicle, the brake shoe The composition comprises: (a) a brake surface for coupling the rolling of the wheel, having a predetermined configuration and a predetermined surface area, (b) a first friction-type composition material having a predetermined shape and initially it extends at least completely over the predetermined surface area of the brake surface of the composition brake shoe, and (c) a second friction type composition material formed as a discrete insert, having a predetermined shape and molded within it. of the first friction type composition material, the second friction type composition material initiates If it is entirely embedded within the first friction-type composition material, a discrete insert surface will be disposed or located facing a predetermined surface area of the brake surface of the composition brake shoe, the surface of the discrete insert will be gradually exposed according to the first material of the invention. friction type composition is eroded due to the friction coupling with the rolling surface of the wheel during normal brake operations, the second friction type composition material exhibits higher abrasive properties than the first friction type composition material, the second Friction type composition material consists essentially of an abrasive or rubbing ceramic material, the first friction type composition material extends completely over the predetermined surface area of the brake surface of the composition brake shoe, after the second friction-type composition material formed as a discrete insert has been worn or consumed, due to the frictional engagement with the wheel running surface during normal braking operations

Description

COMPOSITE SHOE FIELD OF THE INVENTION The present invention relates, in general, to braking equipment for railway vehicles and, more particularly, this invention relates to a brake shoe of the composition type for use in a braking system of a railway type vehicle. and, even more specifically, the invention relates to an improved brake shoe member with an insert of aggressive high friction material to eliminate defects in the running surface of a wheel while substantially minimizing the condition of formation or generation of sparks during the application of the brake in the railway type vehicle.

BACKGROUND OF THE INVENTION Prior to the conception and further development of this invention, it was generally well known in the art to use brake shoes of various types having different compositions to achieve the very specific braking requirements. For example, these compositions may include cast iron and other types of friction materials that are specifically formulated for various predetermined applications.

P1005 / 98MX It is also well recognized, in the technique of brake shoes, that these various types of friction material will normally exhibit several different friction characteristics in a unique manner. These friction characteristics include, for example, both high friction material and low friction material. Obviously, these different friction characteristics can have a significant effect on the distance that will be required to make a railroad type vehicle come to a complete stop. Additionally, this stopping distance can be greatly affected by the various climatic conditions normally encountered by the railway vehicle during operation, for example, humidity or dry weather. In many of the developed countries of the world there are certain critical requirements imposed on the stopping distance of a railway type vehicle. This imposed stopping distance is obviously for security reasons. Additionally, this imposed detention distance must be achievable even in very adverse weather conditions. For example, one of these critical requirements is that a train must have the ability to stop even in wet conditions at approximately 15% of the normal stopping distance that would be achieved during operation in dry conditions.

P1005 / 98MX This particular requirement can generally be easily achieved through the use of a cast-iron type brake shoe, which will exhibit relatively low friction at normal operating speed and relatively high friction at a low speed and at a low speed. static condition. However, as is generally well known in the art, these cast iron brake shoes will normally generate a considerable amount of undesirable noise and dust during the application of the brakes of a railway type vehicle. Consequently, as population centers have expanded and people have moved closer to railroad structures, this undesirable noise and dust has become a major source of concern for those people who are located adjacent to it. structure of railways. Those skilled in the relevant technique of braking railway vehicles generally believe that a means that could probably be used effectively to significantly reduce this undesirable noise to a generally more acceptable level would be to use a friction composition of a lower type in the manufacture of brake shoes.

P1005 / 98MX Although the use of this lower type friction material may be suitable for braking purposes, this type of brake shoe does not provide any benefit towards the reconditioning of a running surface that may have surface defects, such as slabs or flakes. The removal of these surface defects will normally extend the life of a wheel that is in service. A high-friction brake shoe surface could be used which would be aggressive until the wheel surface is reconditioned; however, this design has the disadvantage of creating or generating sparks significantly during brake applications, which could result in a hazardous condition. The Applicant is aware of another design which is a shoe material manufactured entirely from the aggressive abrasion material, however, this shoe must be applied and removed immediately after a brake application at very low speed. Thus, there is a need for a brake shoe that does not present a safety problem due to the sparking condition at the time that the brake shoe reconditions from the defective surface of the tread of a wheel and additionally from a shoe. brake that can continue to be used for the normal operations of P1005 / 98MX braking, after the tread of the wheel has been reconditioned.

SUMMARY OF THE INVENTION The present invention provides a composition brake shoe for use in a rail freight vehicle for reconditioning the rolling surface of the wheel during the normal application of braking in the rail freight vehicle. The composition brake shoe includes a brake surface having a predetermined configuration and a predetermined surface area. Additionally it includes a first friction type composition material that extends over the surface area of the brake surface of this composition brake shoe. The composition brake shoe further contains a second friction type composition material, formed as a discrete insert, having a predetermined shape and being molded into the first friction type composition material, the second friction type composition material initially is fully embedded within the first friction type composition material, a surface of this discrete insert is located facing the predetermined surface area of the brake surface of the composition brake shoe, a surface of P1005 / 98MX - this discrete insert will be exposed gradually as the first friction type composition material is worn by erosion due to the friction engagement with the wheel running surface, during normal braking operations, the second composition material of Friction type exhibits higher abrasive properties than the first friction type composition material, the second friction type composition material consists essentially of an abrasive ceramic material, this first friction type composition material extends completely over the predetermined surface area of the friction type. brake surface of the composition brake shoe, after the second friction type composition material formed as the discrete insert has been worn due to frictional engagement with the wheel running surface, during normal braking operations.

OBJECTIVES AND ADVANTAGES OF THE INVENTION Therefore, it is one of the primary objects of the present invention to provide a brake shoe with abrasive and aggressive material in a composition brake shoe matrix, which will eliminate the effects of the surface rolling of a wheel during normal braking applications.

P1005 / 98MX It is also an object of the present invention to provide a brake shoe which at least substantially minimizes the production of the sparking or sparking condition while eliminating defects in the running surface. It is another object of the present invention to provide a brake shoe that extends the service life of a wheel during service. Still another object of the present invention is to provide a brake shoe which provides the correct friction for braking, while at the same time removing defects from the wheel running surface. Additionally, it is a further object of the present invention to provide a brake shoe that can be used to recondition the tread of a wheel and still remain in service in the rail freight vehicle until the shoe is fully worn. In addition to the various objects and advantages of the present invention which have been described in some specific detail above, various other objects and advantages of the invention will be much more readily apparent to those persons who are particularly experienced in the relevant art of friction of the invention. brake shoe to P1005 / 98MX from the following more detailed description of the invention, particularly when this detailed description is taken in conjunction with the Figures of the accompanying drawings and with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS OR FIGURES Figure 1 is a plan view of the rear or rear part of a conventional rail brake shoe showing a steel backing plate used to mount a brake shoe in the rail vehicle. Figure 2 is a side elevation view of the rail brake shoe illustrated in Figure 1. Figure 3 is a cross-sectional view of a rail brake shoe taken along lines III-III of Figure 1 , which incorporates therein a currently preferred embodiment of the present invention. Figure 4 is a cross-sectional view of a railway brake shoe taken along lines IV-IV of Figure 2. Figure 5 is a cross-sectional view of a railway brake shoe taken along the length of the lines VV of Figure 1 which incorporates therein the currently preferred embodiment of the present invention.

P1005 / 98MX BRIEF DESCRIPTION OF THE CURRENTLY PREFERRED MODALITY AND OF VARIOUS ALTERNATIVE MODALITIES OF THE INVENTION Before proceeding to a more detailed description of the present invention, it should be noted that for reasons of clarity during the understanding of the invention, the identical components with functions identical ones have been designated with the same reference numbers in all the Figures of the drawings. Reference will now be made more specifically to Figures 1 and 2. Illustrated herein is a conventional brake shoe configuration, generally designated 10, capable of incorporating therein an embodiment of the present invention. The brake shoe 10 includes a bracket 1 connected to a back plate 3 to which a brake shoe member of composition type is secured. The brake shoe 10 further includes a stop portion 2 which engages a wedge member (not shown). The back plate 3 and the stop portion 2 are used to locate and attach or connect the brake shoe 10 to the brake head portion (not shown) of the brake beam portion of a predetermined brake system. Reference will now be made more specifically to Figures 3, 4 and 5. Figures 3, 4 and 5 are cross-sectional views taken along the P1005 / 98MX lines III-III, IV-IV and V-V, respectively, of Figures 1 and 2. A currently preferred embodiment of the invention is illustrated therein. As shown therein, the brake shoe 10 has a steel backing plate 3, a backing material layer 4 for joining the first friction type composition material 5 to the backing plate 3. The first material of friction type composition 5 of the brake shoe 10, in accordance with the present invention, is a friction composition type material, which extends over the surface area of the brake shoe 10 and provides the required friction and effort of braking when pushed against the tread of a railway wheel. The surface of the brake shoe 10, when used in a railway braking system, will exhibit a generally arched shape. The first friction type composition material 5 will hereinafter be referred to as the base material 5. Embedded in this base material 5, there is a discrete insert of a second friction type composition material 6. This second material of friction type composition it is formed as a discrete insert, having a predetermined shape, and is molded into the base material 5. The second friction type composition material 6 is initially fully embedded P1005 / 98MX within the base material 5. A surface of this discrete insert of the second friction type composition material 6 will be located facing the predetermined surface area of the brake surface of the composition brake shoe 10. A surface of the second material of friction type composition 6 will be gradually exposed as the base material 5 is eroded or abraded by erosion due to the frictional engagement with the wheel running surface during normal braking operations. The second friction type composition material 6 exhibits greater abrasive properties than the base material 5. The second friction type composition material 6 consists essentially of an abrasive ceramic material used for abrasive wheels. The base material is again fully extended over the predetermined surface area of the brake surface of the brake shoe 10 after the second friction type composition material, formed as a discrete insert, has been worn due to frictional engagement with the wheel running surface during normal braking operations. In a presently preferred embodiment of the invention, the second friction type composition material 6 is an aluminum oxide abrasive ceramic composite. It should be noted that the second material of P1005 / 98MX friction type composition 6 will hereinafter be referred to as the discrete insert 6. In a preferred embodiment of the present invention, this base material 5 is a friction composition material comprising abrasive components selected from a group consisting of morganite , chromite, iron oxide black and silicon carbide and various mixtures thereof. These abrasive components are present in the base material 5 generally in a range of from about 35 to about 45 weight percent. The base material 5 also includes inorganic fillers selected from the group consisting of clay, talc and zinc oxide and various mixtures thereof. These inorganic fillers are present in the base material 5 generally in a range of between about 18 and about 25 weight percent. The base material 5 further includes organic fillers and binders selected from the group consisting of mineral rubber, carbon filler, carbon black, liquid resin, cashew resin, SB rubber and recovered brake composition material and various mixtures thereof. These organic fillers and binders are present in the base material 5 generally in a range of between about 30 and about 40.

P1005 / 98MX percent by weight. The base material 5 also contains various cross-linking and curing agents selected from the group consisting of sulfur, hexamethylenetetramine, activators, accelerators and various mixtures thereof. The crosslinking and curing agents are present individually in the base material 5 generally in concentrations of 1 percent or less. In a preferred embodiment of the invention these abrasive components are present in the base material 5 generally in a range of between about 37 and about 40 weight percent, the inorganic fillers are generally present in a range of between about 21- and about 23. percent by weight and organic fillers and binders are generally present in a range of between about 36 and about 39 weight percent. In a presently preferred embodiment of the invention, the base material 5 is at least twice as aggressive towards the tread of the wheel as the conventional fretting friction composition material used before the present invention. The brake shoe 10 is applied to a rail wheel (not shown) which may exhibit certain effects of a detrimental type on the running surface of the wheel. These defects are called slabs or flakes. As P1005 / 98MX is evident in Figures 3 and 5 of the brake shoe 10, the discrete insert 6 is surrounded by base material 5. As the outer surface of the base material 5 wears through normal braking operations, the discrete insert 6 it is gradually exposed and during any subsequent braking operation provides improved abrasion and reconditioning of the running surface of the rail wheel. This improved abrasion and reconditioning continues until the discrete insert 6 is spent or consumed. However, the reconditioning of the tread of the wheel will continue, but to a lesser degree, even after the discrete insert 6 has been worn or consumed since the composition of the base material 5 is designed to be more aggressive towards the tread of the wheel that the composition of conventional brake brake shoes. In this way, the brake shoe 10, of the present invention, provides adequate braking, while continuing to recondition the tread of the wheel, even after the discrete insert 6 has been consumed and, remains as a brake shoe useful at least to the point of waste of the shoe. A central line of the surface of the discrete insert 6 is preferably located perpendicular to a longitudinal axis of the surface of P1005 / 98MX brake of the base material 5 and is located or disposed within the base material 5 at a depth in the center line of between about 0.1 inches and about 0.3 inches from the brake surface of the brake shoe 10. In a mode currently preferred of the invention, the center line of the surface of the discrete insert 6 is located along a central line of the brake shoe 10 which is located perpendicular to a longitudinal axis of the brake surface of the brake shoe 10. In this presently preferred embodiment of the invention, the depth of this discrete insert 6 in the base material 5 is between 0.125 and 0.25 inches in the center line. In accordance with the present invention, the discrete insert 6 has a thickness of between about 0.125 inches and about 0.375 inches. In the presently preferred embodiment of the invention, the thickness of the discrete insert 6 is, however, between about 0.2 inches and about 0.3 inches. The discrete insert 6 is essentially a rectangular block in the presently preferred embodiment of the invention. This block has a width generally about 3 inches long at the centerline of the discrete insert 6. The width is almost but not P1005 / 98MX completely, through the total width of the brake shoe 10. In the presently preferred embodiment of the invention, the discrete insert 6 additionally has a length of between about 1.5 inches and about 3 inches measured along the length of the longitudinal side of the brake shoe 10. As is evident in Figures 3 and 5, the discrete insert 6 is molded into the base material 5. As the base material 5 is worn or consumed by normal braking operations, the discrete insert 6 is exposed and subsequently provides a more aggressive abrasive machining effect on the tread of the wheel to eliminate surface defects. The thickness and the abrasive characteristics of the discrete insert 6 are controlled to provide the wear of the wheel sufficiently accelerated to clean or erase the defects (slabs or flakes) of the tread of the wheel. In the tests performed on railway wheels exhibiting severe surface defects, photographs were taken of the running surfaces before the brake shoe 10, complete with the base material 5 and the base insert 6, was mounted as a brake shoe of replacement. After the brake shoe with the present invention was installed as a brake shoe 10, photographs were taken again after 210 arrests at 40 P1005 / 98MX miles per hour and, again after 410 stops at 40 miles per hour. Photographs of the wheel surfaces indicated that visible defects were essentially eliminated after a total of 410 arrests. In addition, the AAR specification tests indicated that the stopping distance using the brake shoes with the present invention were completely within acceptable stopping distances for each tested speed. The average stopping distances were virtually at the midpoint of the specification limits of the AAR. The tests were developed with both light and heavy or heavy braking. In this way, the present invention not only reconditions the treads of the wheel with severe defects but also continues to provide adequate braking during the life of the brake shoe. As previously described, the base material 5 is also designed to be more aggressive with the tread of the wheel than a brake shoe of conventional composition and will continue to provide cleaning and reconditioning of the running surface of a wheel but to a much slower speed then that made by the discrete insert 6. This would be analogous to the use of coarse and fine sandpaper in a P1005 / 98MX sanding operation. Although the discrete insert 6 is shown in Figure 5 of the drawings and is also described in the foregoing description, as located in the base material 5 at the center of the brake shoe 10, it is within the scope of the present invention to place to the discrete insert 6 in other positions within the base material 5 in the brake shoe 10. This entire process is designed to extend or extend the service life of a wheel in service. The process requires minimal effort to maintain the tread of the wheel, which has exhibited certain types of tread defects, since all that is required to recondition the tread of the wheel is the replacement of the tread. an existing brake shoe by a brake shoe 10 of the present invention. The rolling surface of the wheel is reconditioned during normal braking operations without any additional work. In this way, the brake shoe 10 reconditions the rolling surface of the wheel and can remain in the railway vehicle during the life of the brake shoe. With the reconditioning of the tread of the wheel, the useful life of the wheel extends or extends significantly. Whereas previously it has been described with P1005 / 98MX detail the currently preferred embodiment and various alternative embodiments of the present invention, it is understood that those persons having experience in the relevant technique of brake shoes can devise various other adaptations and modifications of the invention without deviating from the spirit of the invention. the invention or the scope of the appended claims.

P1005 / 98MX

Claims (20)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A composition brake shoe for use in a rail freight or freight vehicle. for reconditioning the running surface of the wheel of the railway loading vehicle during a normal braking application in said vehicle, the composition brake shoe comprises: (a) a brake surface having a predetermined configuration and a predetermined surface area; (b) a first friction type composition material having a predetermined shape and initially extending at least completely over the predetermined surface area of the brake surface of the composition brake shoe; and (c) a second friction-type composition material formed as a discrete insert, having a predetermined shape, and molded into the first friction-type composition material, the second friction-type composition material will initially be fully embedded within the first type composition material P1005 / 98MX friction, a discrete insert surface will be disposed or located facing the predetermined surface area of the brake surface of the composition brake shoe, the surface of the discrete insert will be gradually exposed as the first friction type composition material is Eroded due to the frictional engagement with the wheel running surface during normal braking operations, the second friction type composition material exhibits higher abrasive properties than the first friction type composition material, the second type composition material The friction consists essentially of an abrasive or rubbing ceramic material, the first friction-type composition material extends completely over the predetermined surface area of the brake surface of the composition brake shoe, after the second composition material of type friction shaped like u No discrete insert has been worn or consumed, due to frictional engagement with the wheel's running surface during normal braking operations.
2. 2. A composition brake shoe for use in a rail freight vehicle for reconditioning the rolling surface of the wheel, according to claim 1, wherein the first material of P1005 / 98MX friction type composition includes: (a) abrasive components selected from the group consisting of morganite, chromite, iron oxide black, silicon carbide and various mixtures thereof, abrasive components are present in the first material of friction type composition generally in a range of between about 35 and about 45 weight percent, (b) inorganic fillers selected from the group consisting of clay, talc, zinc oxide and various mixtures thereof, inorganic fillers are present in the first friction type composition material generally in a range of between about 18 and about 25 weight percent, (c) organic fillers and binders selected from the group consisting of mineral rubber, carbon filler, carbon black, resin liquid, cashew resin, SB rubber, recovered composite brake material and various mixtures thereof, loads and agl Organic builders are present in the first friction type composition material generally in a range of between about 30 and about 40 weight percent and (d) crosslinking and curing agents selected from the group consisting of sulfur, P1005 / 98MX hexamethylenetetramine, accelerators, activators and various mixtures thereof, the crosslinking and curing agents are individually present in the first friction type composition material generally in a concentration of about 1 weight percent or less.
3. 3. A composite brake shoe for use in a rail freight vehicle to recondition the wheel running surface, according to claim 2, wherein the abrasive components are present in the first friction type composition material generally in a range of between about 37 and about 40 weight percent.
4. 4. A composition brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 2, wherein the inorganic fillers are present in the first friction type composition material generally in a range between about 21 and about 23 weight percent.
5. 5. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 2, wherein the organic fillers and binders are present in the first material of P1005 / 98MX friction type composition generally in a range of between about 36 and about 39 weight percent.
6. 6. A composite brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel according to claim 1, wherein the abrasive ceramic material is an aluminum oxide abrasive composite.
7. A composite brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 1, wherein the center line of a discrete insert surface is located perpendicular to an axis longitudinal of the brake surface of the second friction type composition material disposed or located within the first friction type composition material at a depth a in the center line of between about 0.1 inch and about 0.3 inch from the brake surface of the Brake shoe composition.
8. A composite brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 7, wherein a discrete insert surface is disposed or located within the first P1005 / 98MX friction type composition material to the depth in the centerline of between approximately 0.125 inches and approximately 0.25 inches from the brake surface of the brake shoe composition.
9. 9. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 7, wherein the center line of a discrete insert surface is located along a line central of the composition brake shoe located perpendicular to the longitudinal axis of the brake surface of the composition brake shoe.
10. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 9, wherein the center line of a discrete insert surface is located in a location on the shoe brake of composition different from the centerline of the composition brake shoe located perpendicular to the longitudinal axis of the brake surface of the composition brake shoe.
11. 11. A composition brake shoe for use in a rail freight vehicle for reconditioning the rolling surface of the wheel, according to claim 1, wherein the discrete insert P1005 / 98 X is usually a rectangular block.
12. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 11, wherein the discrete insert exhibits a thickness generally of between about 0.125 inches and about 0.375 inches.
13. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel according to claim 11, wherein the thickness of the discrete insert is generally between about 0.2 inches and about 0.3 inches.
14. A composition brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 11, wherein the discrete insert is generally about 3 inches long at the center line of the insert discreet.
15. 15. A composition brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 11, wherein the discrete insert has a length of between about 1.5 inches and about 2.5 inches at long one-sided P1005 / 98MX longitudinal brake shoe.
16. 16. A composition brake shoe for use in a rail freight vehicle to recondition the wheel running surface, according to claim 1, wherein the predetermined configuration of the brake surface is arcuate.
17. 17. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel according to claim 1, wherein the first friction-type composition material is attached or bonded to a backing plate. metal during molding.
18. 18. A composition brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 17, wherein the metal backing plate includes a means for securing the brake shoe of composition. to a brake beam located in the rail freight vehicle.
19. 19. A composition brake shoe for use in a rail freight vehicle for reconditioning the running surface of the wheel, according to claim 1, the presently preferred embodiment of the present invention, the base material 5 is at least twice so aggressive towards the tread of the P1005 / 98MX rolls as a conventional friction composition material for freight or load brake shoes. A composition brake shoe for use in a rail freight vehicle for reconditioning the wheel running surface, according to claim 17, wherein the predetermined shape of the first friction type composition material is generally rectangular on an axle arranged or located perpendicular to that of a longitudinal axis of the brake shoe and the predetermined surface area of the brake surface exhibits a convex shape to conform to a surface of the tread of a railway wheel and an opposite surface radially to the brake surface exhibits a concave shape for molding to the backing plate of the brake shoe and the generally arcuate edges disposed or located along the longitudinal axis of the brake shoe. P1005 / 98MX