The present invention is generally related to hydraulic brake system components, and more particularly, to master cylinders.
Master cylinders are often designed for use with hydraulic braking systems for vehicles. Master cylinders are commonly incorporated into braking assemblies in a variety of vehicles such as, for example, towing trailers, motorcycles, and the like. In the trailer industry, master cylinders are incorporated into surge brake actuators for towing trailers to actuate the trailer's braking system when the towing vehicle pulling the trailer is braking or otherwise slowing. For example, when a vehicle towing a trailer slows or stops, the trailer surges forward with respect to the towing vehicle. A master cylinder mounted onto the trailer may sense the surging of the trailer and actuate the trailer's braking system to apply a braking force to the wheels of the trailer, thus slowing or stopping the trailer in coordination with the slowing or stopping of the towing vehicle.
Master cylinders are important to the trailer industry because master cylinders facilitate the safe and effective operation of trailers being pulled by towing vehicles. Therefore, it is continuously desirable to develop novel apparatus, systems, and methods that improve upon master cylinders used in the trailer industry.
The present invention is directed to apparatus, systems, and methods for incorporating a master cylinder into a hydraulic brake system. An embodiment of the present invention includes a housing, a bore extending through the housing, a cover, and a groove formed in the cover. The housing includes a fluid reservoir formed therein. The bore is capable of supporting a movable piston to actuate the hydraulic braking system. The cover is secured to the housing and the groove in the cover descends away from the center of the cover such that the groove is capable of directing fluid away from the center of the cover.
In the accompanying drawings, which are incorporated in and constitute a part of this specification, embodiments of the invention are illustrated that, together with a general description of the invention given above and the detailed description given below, serve to illustrate the principles of this invention. The drawings and detailed description are not intended to and do not limit the scope of the invention or the claims in any way. Instead, the drawings and detailed description only describe embodiments of the invention, and other embodiments of the invention not described are encompassed by the claims.
While the present invention is described with reference to the embodiments described herein, it should be clear that the present invention should not be limited to such embodiments. Therefore, the description of the embodiments herein is illustrative of the present invention and should not limit the scope of the invention as claimed. As described herein, a master cylinder is generally implemented into a surge actuator for use with a towing trailer; however, upon understand the detailed description and accompanying figures, it will be readily understood by one of ordinary skill in the art that embodiments of the described and illustrated master cylinder may be incorporated into a variety of other vehicles to facilitate braking of such vehicles.
Master cylinders may be designed to facilitate the braking of a trailer coupled to a towing vehicle. Typically, the braking systems of a towing vehicle are designed to slow and stop only the towing vehicle. It will readily be understood that as a towing vehicle slows or stops, it is advantage to provide apparatus, mechanisms or systems that also slow or stop a trailer being towed by the towing vehicle. Embodiments of the master cylinders described and disclosed herein may be designed to sense the slowing or stopping of a towing vehicle and apply a braking force to a trailer in proportion to the stopping or slowing of the towing vehicle.
As can be seen in
The cap 104 may be selectively removed from the extended lip 106 to facilitate the pouring of fluid into the housing 105 and the removal of fluid from the housing 105 through the opening 107. When an appropriate operational volume of fluid is deposited in the housing 105 or an appropriate volume of fluid is removed from the housing 105, the cap 104 may be secured in the lip 106 to reseal the opening 107 and prevent fluid from leaking through the opening 107. The cap 104, extended lip 106, and opening 107 may be generally circular in cross-sectional shape, or may be any shape that allows for reversible sealing of the opening 107.
The lip 106 may be arranged to facilitate the pouring of fluid into the housing 105 and to prevent contaminants from entering the housing 105. For example, the lip 106 may serve as a raised filler lip onto which an operator may rest a fluid container used to pour fluid into the housing 105. By using the lip 106 to rest a fluid container, an operator may more readily fill the housing 105 with fluid without concerns of spilling fluid onto the cover 102 or other exterior surfaces of the master cylinder 100. In addition, the lip 106 may provider a barrier to prevent debris, dirt, or other such contaminants residing on the surface of the cover 102 from passing through the opening 107 and entering the master cylinder 100. For example, when the cap 104 is removed from the extended lip 106 to allow fluid to be added, there is the possibility that contaminants residing on the surface of the cover 102 may flow into or otherwise enter the housing 105. However, the lip 106 extends above the surface of the cover 102 to block the flow of such contaminants through the opening 107 and into the housing 105.
The cover 102 may also include a groove or channel 110 along the upper surface of the cover 102. The groove 110 is arranged as a drainage groove to drain or otherwise move fluids and other substances away from the cover 102. As will be readily understood, a master cylinder 100 that is coupled to a trailer is commonly exposed to the elements during normal operation. For example, the master cylinder 100 is commonly exposed to dirt, grease, moisture, and other such contaminants as a trailer is towed behind a towing vehicle. Such contaminants may settle on the surface of the cover 102 and may cause damage to the cover 102, in the form of rust, oxidation, or other such corrosion, or may cause damage to internal components of the master cylinder 100 if allowed to enter the housing 105.
The drainage grooves 110 are arranged to prevent water and other such fluids that promote corrosion from settling on the cover 102. The grooves 110 are angled, slanted, descended, or otherwise arranged to promote the flow of fluid and contaminants away from the opening 107 and to generally encourage fluids and contaminants to flow off the cover 102. Such an arrangement is particularly affective in controlling moisture and contaminants when the cap 104 is removed from the extended lip 106 during regular maintenance, such as during the filling of the master cylinder 100 with fluid or the bleeding of pressure from the braking system.
In one embodiment, the exterior surface of the cover 102 may be generally angled downward and away from the extended lip 106 to assist the grooves 110 in promoting the flow of fluids and other contaminants way from the opening 107. Although the cover 102 as described and illustrated herein includes one drainage groove 110, other embodiments may include a plurality of grooves or a system of grooves that include multiple legs or channels to promote the flow of fluid and other contaminants away from the opening 107 and off of the cover 102.
In addition, a dust boot 144 may be attached to an opening of the bore 123. The dust boot 144 may prevent foreign particles, such as dirt, dust, grease, moisture, and the like from entering the bore 123 or fluid reservoir 120. The piston 140 may compress the spring 132 to drive fluid through the pressure cup 134 and actuate the braking system of the trailer. The spring 132 may return the piston back to a “neutral” position in which fluid may again enter the bore 123. The master cylinder 100 may be arranged such that the pressure within the master cylinder 100 selectively actuates and disengages the braking system of a trailer or other such towed vehicle.
In an embodiment of a master cylinder 100, the gasket 114 is seated or otherwise positioned between the cover 102 and the housing 105 prior to the assembly of the master cylinder 100. The gasket 114 serves as a sealing member to seal the reservoir 120 formed by the assembly of the cover 102 to the housing 105. The gasket 114 is arranged to prevent fluid within the reservoir 120 of the housing 105 from flowing through the interface between the cover 102 and the housing 105.
The cover 102 may be secured to the housing 105 through fasteners, such as screws, bolts, rivets, and the like (not shown). The cover 102 includes a plurality of fastener apertures 109 and the housing 105 includes a plurality of matching fastener apertures 112. The fastener apertures 109 in the cover 102 are arranged to align with the fastener apertures 112 of the housing 105 such that when the cover 102 is fitted onto the housing 105, fasteners may be passed through the aligned fastener apertures 109, 112 and be secured in the fastener apertures 112 of the housing 105. Such an arrangement may secure the cover 102 to the housing 105. The cover 102 may be attached to the housing 105 such that the attachment is reversible, or alternatively, the cover 103 may be attached to the housing 105 such that the attachment is not reversible. In one embodiment, the fastener apertures 112 of the housing 105 may be threaded such that threaded screws or bolts passing through the fastener apertures 109 of the cover 102 may be secured into the fastener apertures 112 of the housing 105 to secure the cover 102 to the housing 105.
The gasket 114 may include a plurality of apertures 116 that match and align with the fastener apertures 109, 112 of the cover 104 and housing 105. In such an arrangement, the gasket 114 may be positioned between the cover 102 and the housing 105 to seal the interface without interfering with fasteners passed through the fastener apertures 109, 112 to secure the cover 102 to the housing 105. The gasket 114 further includes an opening 115 coinciding with the access opening 107 in the cover 102. The gasket opening 115 is arranged so as not to interfere with fluids passing through the access opening 107, i.e., the gasket opening 115 does not interfere with the fluid communication between the access opening 107 and the fluid reservoir 120 located in the housing 105.
The cover 102 may also include a plurality of posts 108 extending downward from the fastener apertures 109. The posts 108 may be arranged for mating engagement and alignment with the gasket apertures 116 and fastener apertures 112 of the housing 105. Such an arrangement may maintain the alignment or orientation of the gasket 114 with respect to the cover 102 and housing 105 during and after assembly of the master cylinder 100. Engagement of the posts 108 with the fastener apertures 112 of the housing also maintains the alignment or orientation of the cover 102 with respect to the housing 105 during and after assembly of the master cylinder 100. Maintaining alignment and orientation of components reduces or eliminates issues of wear, leakage, or misalignment of the gasket 114, cover 102, housing 105, and other such components of the master cylinder 100.
A coating or sealant may be applied to the gasket 114 prior to assembly of the master cylinder 100 to enhance the sealing capabilities of the gasket 114. In one embodiment, an adhesive is applied to both sides of the gasket 114 to adhere or otherwise bond the gasket 114 to both the cover 102 and the housing 105 during and after assembly of the master cylinder 100. Such an arrangement may enhance the seal provided by the gasket 114, along with enhancing the durability and service life of the seal provided by the gasket 114. Adhesives used in the assembly of the master cylinder 100 may be arranged to cure through the application of pressure. The tightening of fasteners coupling the cover 102 to the housing 105 may generate the appropriate pressure needed to cure adhesives.
In another embodiment, the adhesive may be arranged to provide a bond that allows for disassembly of the master cylinder 100 without damaging the gasket 114, cover 102, or housing 105. In one example, the adhesive may be selected such that the bond created by the adhesive is loosened or broken by the application of a chemical that does not affect the gasket 114 or other master cylinder components. In another example, the adhesive may be selected such that the bond created by the adhesive is sufficient to enhance the sealing ability of the gasket 114, yet may still allow for separation of the gasket 114 from the cover 102 and housing 105 through the application of non-destructive mechanical force.
In another embodiment, a gap filler may be applied to both sides of the gasket 114. A gap filler may enhance the seal of the gasket 114 by filling gaps between the gasket 114 and the cover 102 and housing 105; however, the gap filler may not include any adhesive properties. In such an arrangement, the seal is enhanced without substantially affecting the disassembly of the master cylinder 100. Although the embodiments described include adding a coating to both sides of the gasket 114, it will be readily understood that a coating may be applied to only one side of a gasket 114 or may be applied directly to the cover 102 or housing 105 to enhance the seal between the cover 102 and housing 105. It will also be appreciated that the application of adhesives further forms a master cylinder 100 that is a fully self-contained and separate unit that may be assembled with or other wise utilized by a wide variety of trailers.
With further reference to
The reservoir 120 generally contains brake fluid, or other similar hydraulic fluids. When pressure is bled from the brake lines into the reservoir 120, the fluid in the reservoir 120 may be disturbed. Such disruption often causes fluid to flow upward towards the access opening 107. The splashguard 118 is positioned and arranged to deflect such upwardly flowing fluid to minimize or prevent the fluid from flowing to and through the access opening 107 during bleeding of the brake lines.
As illustrated in
The tabs 121 and body 117 of the splashguard 118 are arranged such that when the tabs 121 are secured in the baffles 122, the body 117 is appropriately positioned to deflect fluid disturbed by bleeding the brake lines from splashing through the access opening 107. Although an embodiment of the splashguard 118 is described and illustrated herein as having a body 117 and a pair of tabs 121, it will be readily appreciated by one of ordinary skill in the art that a splashguard 118 may be of any other appropriate shape or position that blocks the fluid paths from the bleed valves 119 to the access opening 107. The splashguard 118 is preferably made out of stainless steel to resist rust or other such corrosion, but may also be manufactured or otherwise fabricated from any other material suitable for contact with hydraulic fluid and capable of deflecting disturbed fluid.
In addition to deflecting fluid during bleeding of brake lines, the splashguard 118 may deflect fluid disturbed by movement of the piston 140 within the master cylinder to prevent such fluid from flowing out of the access opening 107. It will also be understood that the splashguard 118 may be arranged to be retained within the reservoir 120 without use of the baffles 122. In one example, the splashguard 118 may be shaped or bent in such a manner so as to be self-retained within the reservoir 120.
The cap 104 and the extending lip 106 may each include mating threads such that the cap 104 may be reversibly secured to the lip 106 by engaging the mating threads and twisting or otherwise turning the cap 104 with respect to the lip 106. In one embodiment, the threads of the cap 104 are located on an outside surface of the cap and the threads of the lip 106 are located on an inside surface of the lip 106. In such an arrangement, the cap 104 is positioned and secured within the lip 106 to seal the access opening 107 against leakage of fluid from the reservoir 120. In another embodiment, the threads of the cap 104 are located on an inside surface of the cap 104 and the threads of the lip 106 are located on an outside surface of the lip 106. In such an arrangement, the lip 106 is positioned and secured within the cap 104 to seal the access opening 107 against leakage of fluid from the reservoir 120.
It will be readily appreciated that embodiments as described herein provide for the cap 104 to be reversibly secured to the cover 102. Such arrangements allow for the cap 104 to be removed from the cover 102 for system functions such as filling the reservoir 120 with a fluid, venting the reservoir 120, bleeding the braking system, and the like. The cap 104 may include features on the exterior surfaces of the cap 104 to facilitate manually gripping the cap 104. The cap 104 may further include a diaphragm 154 and a radial seal to further facilitate the sealing of the access opening 107 with the cap 104.
In an embodiment, the threads on the cap 104 and the threads of the lip 106 may both be relatively coarse threads. In such an arrangement, rotating or twisting the cap 104 into the extended lip 106 results in a relatively large vertical displacement with respect to the amount the cap 104 is turned. Such relatively large vertical displacements may provide a more user-friendly arrangement than a cap with fine threads. In addition, course threads are generally more durable and more resistant to stripping or other such deformations due to repeated use as compared to fine threads. In an embodiment, the threads are arranged such that a quarter-turn, i.e., rotating the cap 104 through ninety degrees of rotation, moves the cap 104 from a fully engaged and sealed position to an disengaged position where the cap 104 may be removed from the cover 102.
In an embodiment, a master cylinder 100 may include a decal 146 attached to an exterior surface of the master cylinder 100. In one example, as seen in
In another embodiment, information may be molded, embossed or otherwise incorporated into components of the master cylinder 100. In one example, as illustrated in
Also as illustrated in
An exemplary embodiment of the pressure cup 134 is illustrated in
An exemplary embodiment of the spring 132 is illustrated in
An exemplary embodiment of the cap 104 is illustrated in
Another exemplary embodiment of a cap 204 is illustrated
With further reference to
The invention has been described above and, obviously, modifications and alternations will occur to others upon a reading and understanding of this specification. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.
The application claims priority from U.S. Provisional Patent Application No. 60/856,228, entitled “MASTER CYLINDER” and filed on Nov. 2, 2006, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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60856228 | Nov 2006 | US |