Patent Publication Number: US-2020300312-A1

Title: Sealed Hydraulic Stop Valve for Caliper Guide Pin Assembly

Description:
The current application is a continuation-in-part (CIP) application of a U.S. non-provisional application Ser. No. 15/997,081 filed on Jun. 4, 2018. The U.S. non-provisional application Ser. No. 15/997,081 claims a priority to a U.S. provisional application Ser. No. 62/538,913 filed on Jul. 31, 2017. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a brake system of an automotive vehicle. In particular, the present invention is a sealed hydraulic stop valve for caliper guide pin assembly of an air disk brake that is generally used in heavy equipment, commercial trucks, and trailers to protect the structural integrity of the stored greased within the caliper guide pin assembly. 
     BACKGROUND OF THE INVENTION 
     Air disk brakes have been widely adopted in Europe, primarily as result of their performance advantages over conventional drum brakes. These high-performance brakes are now being widely adopted in U.S. commercial vehicles and industry experts predict air disc braking systems will consume 30% of the US commercial vehicle market by 2020. One major problem faced by users of these brake calipers is their inherent ability to seize up and cause brake failure during service. Air disc calipers, like most brake calipers, comprise two-pieces of iron. One piece known as the carrier, saddle, or bracket, and is bolted to the wheel end in a fixed position. For the purposes of this discussion, we shall hereafter refer to this as the carrier. The second piece of iron is known as the caliper head or caliper body. It contains the mechanical components that receive actuation from an actuating mechanism (i.e. air chamber), and then converts the force from the actuator into mechanical leverage that operates pistons or threaded tappets. Those pistons or tappets then advance to create brake torque. No brake torque or clamping force can be created unless the caliper head can be pulled into the carrier in such a manner as to create the clamping force necessary for the brake pads to clamp the brake disc and retard the vehicle motion. To affect this free motion between the caliper head and carrier, original equipment manufacturers have designed the caliper with a guide pin assembly (sometimes also referred to as a slide pin or slide pin assembly). This assembly consists generally of one or more bushings that fit inside a bore on the caliper head. These bushings may be made of bronze, brass or steel and may or may not be dimpled. A lubricated steel guide pin is then inserted into the bushing. This guide pin is then bolted into the carrier, attaching the carrier to the caliper head, and providing a mechanism for lateral travel from which clamping force can be derived. Between the carrier and the caliper head is a rubber boot that seals the guide pin assembly on one end. At the back end of the caliper is a metal sealing cap that is pressed into the caliper to seal the guide pin assembly. All major manufacturers of calipers use this same process for the guide pin or slide pin assembly. In all cases, their design is defective and such defect results in extremely high maintenance costs for commercial vehicle fleets, and potential catastrophic brake failure for individual vehicles. The cause of this failure is that original equipment (OE) manufacturers have engineered calipers so that they cannot be regularly lubricated and maintained in such a manner as to extend the life of the guide pin assembly. As a result, the high-performance caliper will operate at temperatures exceeding 1,500 degrees Fahrenheit, and will constantly endure torque loads of more than 15,000 lb.-ft. The combination of this high temperature and high torque causes the grease in the guide pin mechanism to literally evaporate, thus ceasing lubrication between the caliper head and carrier. Because there is no mechanism to service the unit (short of a complete replacement of the guide pin assemblies), the caliper continues to deteriorate until it seizes and creates exceptionally high costs of replacement, or catastrophic brake failure. 
     It is therefore an objective of the present invention to provide a sealed hydraulic stop valve for caliper guide pin assembly which provides a sealed compartment for the stored lubrication that is delivered to the guide pin and bushing of a caliper head. Protecting the structural integrity of the lubricant allows the guide pin and bushing to be continually serviced on an ongoing basis therefore improving the fatigue life of the caliper. The present invention creates an airtight compartment that can be easily rotate between a closed position to maintain the lubricant within guide pin assembly and an opened position to input the lubricant into the guide pin assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the present invention. 
         FIG. 2  is an exploded view of the present invention. 
         FIG. 3  is a perspective view of the enlarged tubular guide pin and the lubrication directional plug of the present invention. 
         FIG. 4  is a cross-sectional view of the tubular guide pin. 
         FIG. 5  is a perspective view of an alternative embodiment of the present invention in an exploded state. 
         FIG. 6  is a bottom perspective view of the grease valve for the sealed hydraulic stop valve. 
         FIG. 7  is a side of the grease valve for the sealed hydraulic stop valve, showing the plane upon which a cross sectional view is take shown in  FIG. 8 . 
         FIG. 8  is a cross section view of the grease valve for the sealed hydraulic stop valve taken along line  8 - 8  of  FIG. 7 . 
         FIG. 9  is a bottom perspective view of the coupler for the sealed hydraulic stop valve. 
         FIG. 10  is a side of the coupler for the sealed hydraulic stop valve, showing the plane upon which a cross sectional view is take shown in  FIG. 11 . 
         FIG. 11  is a cross section view of the coupler for the sealed hydraulic stop valve taken along line  11 - 11  of  FIG. 10 . 
         FIG. 12  is a schematic view of the present invention shown within the opened configuration. 
         FIG. 13  is a schematic view of the present invention shown within the closed configuration. 
     
    
    
     DETAIL DESCRIPTIONS OF THE INVENTION 
     All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention. 
     The present invention generally relates to a brake system of an automotive vehicle. More specifically, the present invention relates to air disk brake and internal lubrication thereof. The present invention is a sealed hydraulic stop valve for caliper guide pin assembly which is capable of being continually serviced on an ongoing basis for increased product longevity. The present invention prevents costly maintenance and potential catastrophic brake failure due to a lack of guide pin lubrication (grease) and introduction of outside elements that can compromise the structural integrity of the stored lubrication. The present invention is designed as an aftermarket kit for air disk brakes but could be added to OE manufactured parts as an OE offering. 
     Referring to  FIG. 1-2 , the present invention comprises a tubular guide pin  1 , a cap  6 , a sealed hydraulic stop valve  9 , and a plurality of lubricating grooves  13 . The tubular guide pin  1  acts as the guide pin, or also known as a slide pin, which acts as a track for a caliper head in the air disk brake assembly. The tubular guide pin  1  allows for the caliper head to translate towards and away from a carrier of the air disk brake assembly, similar to traditional guide pins. The size, material composition, and design of the tubular guide pin  1  are subject to fit a variety of air disk brake assemblies. Each of the plurality of lubricating grooves  13  provides a means of applying/dispersing grease to the interface surfaces between the tubular guide pin  1  and a receiving bore of the carrier. In particular, the interface surfaces include an external surface  2  of the tubular guide pin  1  and the internal surface of the receiving bore or bushings of the caliper head. In order to ensure total coverage of the interface surfaces, the plurality of lubricating grooves  13  is radially distributed about the tubular guide pin  1 ; wherein, each of the plurality of lubricating grooves  13  normally traverses into the tubular guide pin  1  from the external surface  2  of the tubular guide pin  1 . Thus, any grease introduced to the plurality of lubricating grooves  13  disperses and covers all the interface surfaces. The grease is introduced to the plurality of lubricating grooves  13  through a front surface  4  of the tubular guide pin  1 . In particular, each of the plurality of lubricating grooves  13  traverses into the tubular guide pin  1  from the front surface  4  of the tubular guide pin  1 . The grease within the present invention is retained and sealed off by the cap  6 . The cap  6  is concentrically positioned with the tubular guide pin  1 . Additionally, the cap  6  is positioned about the tubular guide pin  1 , adjacent to the front surface  4  of the tubular guide pin  1 , in order to form a liquid seal at the front surface  4  of the tubular guide pin  1 . 
     The front surface  4  of the tubular guide pin  1  receives the grease through the sealed hydraulic stop valve  9 . The sealed hydraulic stop valve  9  is a hydraulic valve that receives, regulates, and distributes grease into the present invention. A variety of different types of hydraulic valves may be used as the sealed hydraulic stop valve  9 . In particular, the sealed hydraulic stop valve  9  is positioned adjacent to the cap  6 , opposite the tubular guide pin  1 , to allow for grease injection without full deconstruction and maintenance of the caliper. The sealed hydraulic stop valve  9  is adjacently integrated into the cap  6  in order to establish a fluid connection between an external environment and the interior of the cap  6 , i.e. the front surface  4  of the tubular guide pin  1 . Resultantly, the sealed hydraulic stop valve  9  is fluid communication with each of the plurality of lubricating grooves  13 . 
     Referring to  FIG. 1-2 , it is preferred that each of the plurality of lubricating grooves  13  is curved for maximum grease penetration. In particular, each of the plurality of lubricating grooves  13  comprises a curved portion  14  and a guide portion  15 . The curved portion  14  is an elongated narrow cut or depression that is positioned extending along the tubular guide pin  1 . Additionally, the elongated narrow cut curves along a semi-helical (a semi-circular) path with a central axis being the central axis of the tubular guide pin  1 . This ensures that all portions of the external surface  2  for the tubular guide pin  1  are covered in grease. The guide portion  15  is a small cut or depression in the front surface  4  of the tubular guide pin  1  that receives grease and directs said grease towards the curved portion  14 . More specifically, the guide portion  15  is positioned adjacent to the front surface  4  of the tubular guide pin  1  and extends from an internal surface  3  of the tubular guide pin  1  to the external surface  2  of the tubular guide pin  1 . Additionally, the guide portion  15  is positioned adjacent to the curved portion  14  in order to put the guide portion  15  in fluid communication with the curved portion  14 . The length, size, cross-section, number of, and positioning of the plurality of lubricating grooves  13  is subject to change to meet the needs and requirements of different brake assemblies as well as the needs of the user. In a preferred embodiment of the present invention, a cross-section of each of the plurality of lubricating grooves  13  is preferably semi-circular shaped. 
     Referring to  FIG. 2 , similar to traditional designs, the cap  6  comprises a tubular portion  7  and a disk portion  8 . The tubular portion  7  is an elongated tube sized to complimentary fit over the tubular guide pin  1  to attach the cap  6  to the tubular guide pin  1 . More specifically, the tubular portion  7  is concentrically positioned about the tubular guide pin  1 , adjacent to the front surface  4  of the tubular guide pin  1 . The disk portion  8  is a thin circular structure which closes off the tubular portion  7  and, thus, the tubular guide pin  1 . The disk portion  8  is concentrically positioned with the tubular portion  7 . Additionally, the disk portion  8  is terminally and perimetrically connected to the tubular portion  7 . 
     Referring to  FIG. 5 , the lubrication directional plug  16  fills the internal space of the tubular guide pin  1 , thus forcing any grease introduced through the sealed hydraulic stop valve  9  to be redirected to the plurality of lubricating grooves  13 . Referring to  FIG. 2 , the lubrication directional plug  16  comprises a cylindrical body  17  and a plurality of directional grooves  19 . The cylindrical body  17  is complimentary sized to the internal space of the tubular guide pin  1 . The cylindrical body  17  is concentrically positioned within the tubular guide pin  1  with a front surface  18  of the cylindrical body  17  being positioned coplanar with the front surface  4  of the tubular guide pin  1 . Thus, the front surface  18  of the cylindrical body  17  receives the grease being injected through the sealed hydraulic stop valve  9 . The plurality of directional grooves  19  receives the injected grease and redirects it to plurality of lubricating grooves  13 . In particular, the plurality of directional grooves  19  is radially distributed about the cylindrical body  17 ; wherein each of the plurality of directional grooves  19  normally traverses into the front surface  18  of the cylindrical body  17 . For efficient flow of grease, each of the plurality of directional grooves  19  is in fluid communication with a corresponding groove from the plurality of lubricating grooves  13 . In an alternative embodiment, the lubrication directional plug  16  comprises only the cylindrical body  17  as any grease entering through the sealed hydraulic stop valve  9  still leaks toward the plurality of lubricating grooves  13 . 
     The number within the plurality of directional grooves  19  preferably matches the number within the plurality of lubricating grooves  13 . Additionally, the size, geometry, and design of each of the plurality of directional grooves  19  matches the size, geometry, and design of each of the plurality of lubricating grooves  13 . This ensures a smooth fluid flow between the plurality of directional grooves  19  and the plurality of lubricating grooves  13 . More specifically, a cross-section for each of the plurality of directional grooves  19  is semi-circular shaped. Furthermore, in the preferred embodiment of the present invention, a first end  20  of each of the plurality of directional grooves  19  is positioned coincident with each other, at the center of the front surface  18  of the cylindrical body  17 . The center of the front surface  18  of the cylindrical body  17  coincides with an output of the sealed hydraulic stop valve  9 ; and resultantly, the first end  20  of each of the plurality of directional grooves  19  receives the grease entered into the present invention through the sealed hydraulic stop valve  9 . A second end  21  of each of the plurality of directional grooves  19  is positioned adjacent with a corresponding groove from the plurality of lubricating grooves  13  to establish a fluid communication. 
     Referring to  FIG. 5 , in one embodiment of the present invention, the lubrication directional plug  16  comprises the cylindrical body  17  and a removal hole  26 . In the preferred embodiment, the front surface  18  of the cylindrical body  17  redirects grease towards the plurality of lubricating grooves  13 . The cylindrical body  17  is concentrically positioned within the tubular guide pin  1  with the front surface  18  of the cylindrical body  17  being positioned coplanar with the front surface  4  of the tubular guide pin  1 . The removal hole  26  provides a means of removing the cylindrical body  17  from the tubular guide pin  1 . More specifically, the removal hole  26  concentrically traverses into the front surface  18  of the cylindrical body  17  such that a pick may be inserted into the removal hole  26  and pull the lubrication directional plug  16  out of the tubular guide pin  1 . 
     Referring to  FIG. 3  and  FIG. 4 , for mounting and installment purposes, in the preferred embodiment of the present invention comprises an annular groove  22  and a mounting tube  24 . The annular groove  22  is positioned adjacent to a rear surface  5  of the tubular guide pin  1 . Additionally, the annular groove  22  laterally traverses into the tubular guide pin  1  from the external surface  2  of the tubular guide pin  1 . In order to prevent over greasing and possibly hydro-locking the assembly, a grease dam is used. The grease dam prevents grease from filling any portions besides the interface surfaces. More specifically, the grease dam is formed by positioning a distal end  23  of each of the plurality of lubricating grooves  13  offset from the annular groove  22 , thus creating a physical barrier. The grease dam limits the amount of grease allowed in the present invention. Once grease reaches the grease dam of each of the plurality of lubricating grooves  13 , back pressure is created which causes the sealed hydraulic stop valve  9  to cease inputting process of grease. The offset distance between the distal end  23  of each of the plurality of lubricating grooves  13  and the annular groove  22  is subject to change to meet various performance and lubrication needs. The mounting tube  24  allows the tubular guide pin  1  to be fastened to the carrier. The mounting tube  24  is positioned adjacent to the rear surface  5  of the tubular guide pin  1  and is concentrically positioned within the tubular guide pin  1 . More specifically, a first portion of the mounting tube  24  is positioned within the tubular guide pin  1  and a second portion of the mounting tube  24  is externally positioned to the tubular guide pin  1 . The mounting tube  24  is laterally and perimetrically connected to the tubular guide pin  1 . The first portion acts as an interlocking component by fitting in a corresponding bore of the carrier head. This anchors the mounting tube  24  to the carrier head in terms of lateral movement. The second portion acts as a flange for a fastening bolt. The fastening bolt traverses through the mounting tube  24  with a head portion pressing against the second portion and the threaded portion of the fastening bolt being engaged to the carrier head. Resultantly, the present invention is secured to the carrier head. 
     In alternative embodiments of the present invention, other mounting and installment means, components, and methods may be utilized depending on the type of caliper, manufacturing methods, vehicle type/brand, and other similar factors. For alternative means, one particular characteristic is consistent, the grease dam. In general, the distal end  23  of each of the plurality of lubricating grooves  13  is positioned offset from the rear surface  5  of the tubular guide pin  1 . 
     Referring to  FIG. 2  and  FIG. 6-11 , the sealed hydraulic stop valve  9  is a hydraulic shut-off valve and comprises a grease valve  50 , a coupler  59 , a plurality of outlet channels  65 , an overflow fitting  69 , and an input fitting  68 . Referring to  FIG. 6-8 , the grease valve  50  that function as the rotatable component within the sealed hydraulic stop valve  9  comprises a main body  51 , a tubular attachment  55 , an inlet opening  57 , and a main feed chamber  58 . In reference to general configuration of the sealed hydraulic stop valve  9 , the main body  51  and the tubular attachment  55  are adjacently connected to each other in such a way that the main body  51  and the tubular attachment  55  are concentrically positioned along a central axis. The main body  51  is preferably formed into a hemispherical shape thus providing a tangential surface for input fitting  68  to be mounted or connected. The tubular attachment  55  is preferably a cylindrical body thus allowing tubular attachment  55  to be rotatably mounted within the coupler  59 . The main feed chamber  58  traversing into the tubular attachment  55  from a top surface  52  of the main body  51  and delineates an elongated channel. The inlet opening  57  traverses into the main feed chamber  58  from a lateral surface  53  of the main body  51 , wherein the inlet opening  57  angularly intersects with the main feed chamber  58 . The overflow fitting  69  is slidably positioned within the main feed chamber  58  to regulate the amount of grease within the present invention. The input fitting  68  is externally connected onto the lateral surface  53  so that grease can be injected into the sealed hydraulic stop valve  9 . As a result, the inlet opening  57  is selectively in fluid communication with the coupler  59  through the plurality of outlet channels  65  so that the grease can be distributed into the present invention. The inlet opening  57  is selectively in fluid communication with an overflow opening  54  of the main body  51  through the overflow fitting  69  so that the overflow fitting  69  can be activated regulate the amount of grease. 
     Referring to  FIG. 8 , the input fitting  68  is concentrically positioned to the inlet opening  57  and hermetically connected onto the lateral surface  53  of the main body  51 . In order to discharge grease into the main feed chamber  58 , the input fitting  68  is in fluid communication with the inlet opening  57 . More specifically, the input fitting  68  is a mechanical device that allows for the flow of grease in one direction. Thus, the input fitting  68  receives the grease through a hand-grease gun, or any other device with similar capabilities. 
     Referring to  FIG. 8 , the overflow fitting  69  is a pressure activated pop-up valve for the overall system that ensures that the grease within the present invention is under a specific pressure, therefore regulating the amount of grease within the present invention. If at one point, the internal pressure of the present invention surpasses a specific pressure, the overflow fitting  69  is activated and grease is released through the overflow fitting  69  automatically. In order words, when the internal pressure of the present invention is below the specific pressure, the flow of grease is continuously released into the present invention as the inputted grease is discharged into the plurality of lubricating grooves  13 . When the plurality of lubricating grooves  13  is filled with grease, the internal pressure of the present invention exceeds the specific pressure and activates the overflow fitting  69 . As a result, the flow of grease is discharged through the overflow opening  54 , wherein the overflow opening  54  is delineated by the main feed chamber  58  about the top surface  52 . 
     Referring to  FIG. 9-11 , the coupler  59  that mounts the sealed hydraulic stop valve  9  onto the cap  6  and stays stationary within the present invention comprises a connector wall  60 , an outer wall  61 , an inner wall  62 , a distribution chamber  63 , and a base  64 . More specifically, the connector wall  60 , the outer wall  61 , the inner wall  62 , and the base  64  are concentrically positioned of each other thus delineating two different compartments. Furthermore, the base  64  and the connector wall  60  are oppositely positioned of each other about the inner wall  62 . The inner wall  62  is radially positioned within the outer wall  61 . The outer wall  61  is terminally connected to the connector wall  60 . The inner wall  62  is terminally connected to the connector wall  60 . In other words, the outer wall  61  is perimetrically connected to an outer edge of the connector wall  60 . The inner wall  62  is perimetrically connected to an inner edge of the connector wall  60 , wherein the connector wall  60  is a ring shaped body. The base  64  is perimetrically connected around the inner wall  62 , wherein a receiver compartment is delineated within the base  64  and the inner wall  62 . The receiver compartment provides an empty space to receive the tubular attachment  55  so that the grease valve  50  can be rotatably mounted to the coupler  59 . More specifically, an outer surface  56  of the tubular attachment  55  is internally positioned to an inner wall  62  of the coupler  59  so that the tubular attachment  55  can be rotatably positioned within the inner wall  62 . The distribution chamber  63  is interspaced within the inner wall  62 , the outer wall  61 , and the connector wall  60  so that the distribution chamber  63  can be opened to the cap  6 . 
     The present invention further comprises a valve-receiving coupler  25  for attaching the coupler  59  to the cap  6  as shown in  FIG. 5 . The valve-receiving coupler  25  is concentrically integrated into the disk portion  8 . More specifically, the valve-receiving coupler  25  comprises a valve hole and a coupling tube. The valve hole traverses through the disk portion  8  and the coupling tube is concentrically positioned with the valve hole, adjacently connected to the disk portion  8 . The valve-receiving coupler  25  is internally threaded to interlock with coupler  59 . An output fitting  70  that is externally positioned on the outer wall  61  is threadedly attached within the valve-receiving coupler  25 . 
     Referring to  FIG. 8  and  FIG. 11 , the plurality of outlet channels  65  comprises at least one valve channel  66  and at least one coupler channel  67  so that the inputted grease can be discharged from the tubular attachment  55  to the distribution chamber  63 . More specifically, the valve channel  66  traverses through the tubular attachment  55 . The coupler channel  67  traverses through the inner wall  62  of the coupler  59 . Furthermore, the valve channel  66  and the coupler channel  67  are radially aligned with each other so that the present invention can be in between an opened configuration and a closed configuration as the grease valve  50  is rotated about the central axis. 
     For example, when grease valve  50  is preferably rotated in the counterclockwise direction, the valve channel  66  is concentrically aligned with the coupler channel  67  thus converting the present invention from the closed configuration to the opened configuration as shown in  FIG. 12 . As a result, the inlet opening  57  is in fluid communication with the distribution chamber  63  through main feed chamber  58 , the valve channel  66 , and the coupler channel  67  thus allowing the grease to discharge into the plurality of lubricating grooves  13  through the cap  6 . However, the present invention can also alternatively convert from the closed configuration to the opened configuration via counterclockwise rotation of the grease valve  50 . 
     For example, when grease valve  50  is preferably rotated in the clockwise direction, the valve channel  66  is radially offset from the coupler channel  67  thus converting the present invention from the opened configuration to the closed configuration as shown in  FIG. 13 . As a result, the inlet opening  57  is in fluid communication with the tubular attachment  55  through main feed chamber  58  thus preventing the grease to discharge into the plurality of lubricating grooves  13  through the cap  6 . Furthermore, the offset positioning of the valve channel  66  and the coupler channel  67  form a hermetic connection between the cap  6  and the sealed hydraulic stop valve  9 . However, the present invention can also alternatively convert from the opened configuration to the closed configuration via clockwise rotation of the grease valve  50 . 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.