Patent Description:
A system and method of checking sealing of a brake caliper housing is disclosed in <CIT>. <CIT> discloses a method of monitoring leaks in a braking device in which an internal pressure of a pressure chamber of the braking device is detected and evaluated during a period of time with a plurality of data points that are recorded at different times and that include at least one braking operation with at least one applied and one released operating state.

The present invention is defined by a method of checking sealing of a brake caliper housing according to claim <NUM> and a brake caliper housing according to claim <NUM>.

Preferred embodiments of the present invention are laid down in the dependent claims.

The present invention may allow a brake caliper housing to be provided with internal passages that allow sealing of a central cavity of a caliper housing as well as sealing of guide pin passages to be evaluated. As such, the integrity of seals associated with guide pin assemblies and components that enclose the central cavity may be simultaneously checked. Moreover, seal integrity may be checked with or without the wheels installed which may reduce inspection time. For example, seals associated with the guide pin assemblies are currently checked by removing a wheel and visually inspecting seals or boots associated with the guide pin assembly. Such a visual inspection takes more time since the wheel must be removed and is less reliable than a non-visual check in which sealing integrity is actively assessed by changing the pressure inside the caliper housing and determining whether a seal is actually functioning as intended.

The brake caliper housing may define a through hole that extends from the cavity.

The pressure check device may be fluidly connected to the cavity via the through hole.

Determining the sealing condition may include detecting the pressure inside the cavity after changing the pressure.

The first guide pin opening may be sealed when the detected pressure inside the cavity remains stable for a predetermined period of time.

The first guide pin opening may not be sealed when the detected pressure inside the cavity does not remain stable for the predetermined period of time.

Changing the pressure may include increasing the pressure inside the cavity and the first guide pin opening.

The method may further comprise decreasing the pressure inside the cavity and the first guide pin opening after determining whether the pressure inside the cavity remains stable.

Changing the pressure may include decreasing the pressure inside the cavity and the first guide pin opening.

The method may further comprise increasing the pressure inside the cavity and the first guide pin opening after determining whether the pressure inside the cavity remains stable.

The brake caliper housing may include a second guide pin opening that receives a second guide pin. The brake caliper housing may include a second internal passage that extends from the cavity to the second guide pin opening. Determining the sealing condition may include detecting the pressure inside the cavity, the guide pin opening, and the second guide pin opening.

The internal passage and the second internal passage may be spaced apart from each other. The guide pin opening and the second guide pin opening may be sealed when the detected pressure remains stable for a predetermined period of time.

According to the present invention, a brake caliper housing is provided. The brake caliper housing comprises: a body that defines: a cavity; a first guide pin opening that is spaced apart from the cavity and that is adapted to receive a first guide pin that facilitates sliding movement of the brake caliper housing; and a first internal passage that extends from the cavity to the first guide pin opening to fluidly connect the cavity to the first guide pin opening.

The first internal passage may become progressively narrower as the first internal passage extends from the cavity to the first guide pin opening.

The body may define a through hole that extends through a back wall of the brake caliper housing to the cavity. The through hole may extend along a through hole axis. The first internal passage may extend away from the through hole axis.

The body may have a front wall that is disposed opposite the back wall and that defines an aperture of the cavity. The first internal passage may be axially positioned between the front wall and the back wall.

The body may define a second guide pin opening that is spaced apart from the cavity and that is adapted to receive a second guide pin that facilitates sliding movement of the brake caliper housing. The body may define a second internal passage that extends from the cavity to the second guide pin opening to fluidly connect the cavity to the second guide pin opening.

The first internal passage may be spaced apart from the second internal passage.

The second internal passage may become progressively narrower as the second internal passage extends from the cavity to the second guide pin opening.

The body may include a first lateral cavity side and a second lateral cavity side that are disposed at opposing lateral sides of the cavity. The first internal passage may extend from the first lateral cavity side to the first guide pin opening. The second internal passage may extend from the second lateral cavity side to the second guide pin opening.

The first internal passage may be disposed proximate a top end of the first lateral cavity side. The first internal passage may be disposed above the first guide pin opening.

Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention, which is defined by the appended claims.

Referring to <FIG>, an example of a brake assembly <NUM> is shown. The brake assembly <NUM> may be provided as part of a vehicle, such as a motor vehicle like a truck, bus, farm equipment, military transport or weaponry vehicle, cargo loading equipment for land, air, or marine vessels, or a trailer. The brake assembly <NUM> may be configured as a disc brake. In at least one configuration, the brake assembly <NUM> may include a brake carrier <NUM>, a brake caliper <NUM>, a pair of brake pad assemblies <NUM>, and optionally a retainer bracket <NUM>. Referring primarily to <FIG>, the brake assembly <NUM> may include components that may facilitate movement of the brake pad assemblies <NUM>, such as one or more guide pin assemblies <NUM>, a brake actuator <NUM>, an operating shaft <NUM>, a yoke <NUM>, a tappet <NUM>, a piston <NUM>, and a wear adjuster mechanism <NUM>.

Referring to <FIG>, the brake carrier <NUM> may be configured to be fixedly mounted to the vehicle. For example, the brake carrier <NUM> may be directly or indirectly mounted to an axle assembly or a steering knuckle. The brake carrier <NUM> may receive and support the brake pad assemblies <NUM> in a manner that permits the brake pad assemblies <NUM> to move along an axis toward and away from the brake rotor <NUM> while inhibiting rotation of the brake pad assemblies <NUM> about the axis. For instance, the brake carrier <NUM> may engage multiple sides of a brake pad assembly <NUM>, such as left, right, and bottom sides. The brake carrier <NUM> may include a rotor opening that may receive a brake rotor <NUM>. As such, the brake carrier <NUM> may straddle the brake rotor <NUM> and help position the brake pad assemblies <NUM> on opposite sides of the brake rotor <NUM>.

Referring to <FIG> and <FIG>, the brake caliper <NUM> may receive various components of the brake assembly <NUM>. In addition, the brake caliper <NUM> may facilitate positioning of the brake pad assemblies <NUM> with respect to the brake rotor <NUM> to facilitate braking of the vehicle. In at least one configuration, the brake caliper <NUM> may be mounted to the brake carrier <NUM> and may include a caliper housing <NUM> and a caliper bridge <NUM>.

Referring primarily to <FIG>, the caliper housing <NUM>, which may also be referred to as a brake caliper housing, may be moveably disposed on the brake carrier <NUM>. For example, the caliper housing <NUM> may be slidably disposed on a pair of guide pin assemblies <NUM> that may be fixedly coupled to the brake carrier <NUM>. An example of a guide pin assembly <NUM> is shown in more detail in <FIG>. As is best shown in <FIG>, the caliper housing <NUM> may facilitate mounting of the brake actuator <NUM>. As is best shown in <FIG> and <FIG>, the caliper housing <NUM> has a body <NUM> that defines a cavity <NUM>, at least one guide pin opening <NUM>, and at least one internal passage <NUM>, and may have an opening <NUM> and a hole <NUM>.

The body <NUM> of the caliper housing <NUM> may be configured as a unitary one-piece component. The body <NUM> may be integrally formed with the caliper bridge <NUM> or the body <NUM> and the caliper bridge <NUM> may be separate parts that may be fastened together.

Referring to <FIG>, <FIG>, and <FIG>, the cavity <NUM> may receive or partially receive various components that facilitate movement of the brake pad assemblies <NUM>, such as the operating shaft <NUM>, yoke <NUM>, tappet <NUM>, piston <NUM>, and the wear adjuster mechanism <NUM>. The cavity <NUM> may be at least partially defined by various walls of the caliper housing <NUM> or sides of the body <NUM>, such as a front wall <NUM> (best shown in <FIG>), a back wall <NUM>, a first lateral cavity side <NUM>, a second lateral cavity side <NUM>, a top cavity side <NUM>, and a bottom cavity side <NUM>.

Referring to <FIG>, the front wall <NUM> may face toward the brake carrier <NUM>, a back side of a brake pad assembly <NUM>, and the brake rotor <NUM>. The front wall <NUM> may define an aperture <NUM> of the cavity <NUM>. The aperture <NUM> may be at least partially enclosed by a cover plate <NUM> that may be fixedly mounted to the caliper housing <NUM>, such as with fasteners like bolts. The front wall <NUM> may be disposed opposite the back wall <NUM>.

Referring to <FIG>, <FIG>, and <FIG>, the back wall <NUM> may face away from the brake carrier <NUM> and the brake rotor <NUM>. The back wall <NUM> may define the opening <NUM> and the hole <NUM>.

Referring to <FIG> and <FIG>, the first lateral cavity side <NUM> may be disposed at a first lateral end of the cavity <NUM>. The first lateral cavity side <NUM> may extend between the front wall <NUM> and the back wall <NUM>.

The second lateral cavity side <NUM> may be disposed at a second lateral end of the cavity <NUM>. As such, the second lateral cavity side <NUM> may be disposed opposite the first lateral cavity side <NUM>. The second lateral cavity side <NUM> may extend between the front wall <NUM> and the back wall <NUM>.

The top cavity side <NUM> may be disposed proximate the top of the cavity <NUM>. The top cavity side <NUM> may extend between the front wall <NUM> and the back wall <NUM>. The top cavity side <NUM> may also extend between the first lateral cavity side <NUM> and the second lateral cavity side <NUM>. For instance, the top cavity side <NUM> may extend from a first end of the first lateral cavity side <NUM> to a first end of the second lateral cavity side <NUM>.

The bottom cavity side <NUM> may be disposed opposite the top cavity side <NUM>. The bottom cavity side <NUM> may extend between the front wall <NUM> and the back wall <NUM>. The bottom cavity side <NUM> may also extend between the first lateral cavity side <NUM> and the second lateral cavity side <NUM>. For instance, the bottom cavity side <NUM> may extend from a second end of the first lateral cavity side <NUM> to a second end of the second lateral cavity side <NUM>.

Referring to <FIG> and <FIG>, the opening <NUM> may extend from the cavity <NUM> through the back wall <NUM> of the caliper housing <NUM>. In at least one configuration, a shaft of the brake actuator <NUM> may extend through the opening <NUM> to facilitate actuation of the operating shaft <NUM>. The opening <NUM> may be disposed above an axis <NUM>.

The hole <NUM> may be a through hole that may extend from the cavity <NUM> through the back wall <NUM> of the caliper housing <NUM>. The hole <NUM> may be spaced apart from the opening <NUM>. The hole <NUM> may be disposed above a brake rotor axis of rotation <NUM>, which is best shown in <FIG>, and below the axis <NUM>. The hole <NUM> may receive a plug, fitting, or combinations thereof as will be discussed in more detail below. The hole <NUM> may extend along a through hole axis <NUM>.

Referring to <FIG> and <FIG>, at least one guide pin opening <NUM> may be defined by the body <NUM> of the caliper housing <NUM>. In the configuration shown, two guide pin openings <NUM> are provided that are spaced apart from each other and positioned on opposite sides of the cavity <NUM>. Each guide pin opening <NUM> may receive a corresponding guide pin assembly <NUM> that facilitates sliding movement of the caliper housing <NUM> with respect to the brake carrier <NUM> as will be discussed in more detail below. Each guide pin opening <NUM> may be configured as a through hole that may be spaced apart from the cavity <NUM> and that may extend along a guide pin axis <NUM>. The guide pin axes <NUM> may be disposed substantially parallel to each other. The term "substantially parallel" as used herein means the same as or very close to parallel and includes features or axes that are within ±<NUM>° of being parallel each other.

At least one internal passage <NUM> may be defined by the body <NUM> of the caliper housing <NUM>. In the configuration shown, two internal passages <NUM> are illustrated. An internal passage <NUM> may be disposed inside the body <NUM> and extend from the cavity <NUM> to a guide pin opening <NUM>. For instance, a first internal passage <NUM> extends from the cavity <NUM> to the first guide pin opening <NUM> to fluidly connect the cavity <NUM> to the first guide pin opening <NUM>. Similarly, a second internal passage <NUM> may extend from the cavity <NUM> to the second guide pin opening <NUM> to fluidly connect the cavity <NUM> to the second guide pin opening <NUM>. In at least one configuration, the first internal passage <NUM> may be spaced apart from and may not intersect the second internal passage <NUM>.

The internal passages <NUM> may generally extend laterally outboard and away from the center of the cavity <NUM>. As such, the internal passages <NUM> may extend away from the through hole axis <NUM>. For instance, the first internal passage <NUM> may extend from the first lateral cavity side <NUM> to the first guide pin opening <NUM>. The second internal passage <NUM> may extend from the second lateral cavity side <NUM> to the second guide pin opening <NUM>. In at least one configuration, the first internal passage <NUM>, the second internal passage <NUM>, or both may be disposed proximate the top cavity side <NUM>. For instance, the first internal passage <NUM>, the second internal passage <NUM>, or both may be disposed proximate a top end of the first lateral cavity side <NUM> and the second lateral cavity side <NUM>. As such, the ends of the internal passages <NUM> that are located adjacent to the cavity <NUM> may be disposed above the guide pin openings <NUM>. As is best shown in <FIG>, an internal passage <NUM> may be axially positioned between the front wall <NUM> and the back wall <NUM> of the caliper housing <NUM>.

An internal passage <NUM> may be provided in various configurations. In the configuration shown in <FIG>, the internal passages <NUM> are illustrated as having a substantially constant height or shape from end to end. In the configuration shown in <FIG>, the internal passages <NUM> are illustrated as having a height or shape that varies. For instance, an internal passage <NUM> may become progressively narrower as the internal passage <NUM> extends from the cavity <NUM> toward a corresponding guide pin opening <NUM>.

Referring to <FIG> and <FIG>, the caliper bridge <NUM> may be integrally formed with the caliper housing <NUM> or may be a separate part that is fixedly disposed on the caliper housing <NUM>. For example, the caliper bridge <NUM> may be coupled to the caliper housing <NUM> with one or more fasteners, such as bolts. In at least one configuration, the caliper bridge <NUM> may cooperate with the caliper housing <NUM> to at least partially define an opening that may facilitate insertion and removal of the brake pad assemblies <NUM>.

Referring to <FIG>, a pair of brake pad assemblies <NUM> may be received in and may be supported by the brake carrier <NUM>. The brake pad assemblies <NUM> may be disposed on opposite sides of the brake rotor <NUM> and may be engageable with the brake rotor <NUM> to slow rotation of the brake rotor <NUM> and an associated wheel about a brake rotor axis of rotation <NUM>. One brake pad assembly <NUM> may be positioned between the caliper housing <NUM> and the brake rotor <NUM> and may be referred to as an inboard brake pad assembly <NUM>. The brake pad assembly <NUM> located on the opposite side of the brake rotor <NUM> may be positioned between the caliper bridge <NUM> and the brake rotor <NUM> and may be referred to as an outboard brake pad assembly <NUM>. The brake pad assemblies <NUM> may include a backplate <NUM> and friction material <NUM>.

The backplate <NUM> may be a structural member of a brake pad assembly <NUM>. The backplate <NUM> may be configured as a generally flat plate and may be made of any suitable material, such as metal or a metal alloy. As is best shown in <FIG>, a side of the backplate <NUM> that faces away from the friction material <NUM> may engage or contact the tappet <NUM>.

The friction material <NUM> may be disposed on a side of the backplate <NUM> that may face toward the brake rotor <NUM>. The friction material <NUM> may contact the brake rotor <NUM> during vehicle braking.

Referring to <FIG>, the retainer bracket <NUM> may be removably mounted to the brake caliper <NUM>. For example, the retainer bracket <NUM> may extend across the brake pad assemblies <NUM> and the opening in the brake caliper <NUM> to help retain the brake pad assemblies <NUM> in the brake carrier <NUM> when the retainer bracket <NUM> is secured to the brake caliper <NUM>. Conversely, the retainer bracket <NUM> may be detached from or removed from the brake caliper <NUM> to permit removal of the brake pad assemblies <NUM> or installation of the brake pad assemblies <NUM> via the opening.

Referring to <FIG>, one or more guide pin assemblies <NUM> may slidably couple the caliper housing <NUM> to the brake carrier <NUM> such that the caliper housing <NUM> may slide along the guide pin axis <NUM> with respect to at least a portion of the guide pin assembly <NUM>. A guide pin assembly <NUM> may extend from the brake carrier <NUM> into a corresponding guide pin opening <NUM>. A guide pin assembly <NUM> may have any suitable configuration. For instance, a guide pin assembly <NUM> may include a fastener <NUM>, a sleeve <NUM>, and at least one bushing <NUM>. In addition, one or more sealing components <NUM> may be provided with or associated with a guide pin assembly <NUM> to help isolate a guide pin opening <NUM> and components that may be received in the guide pin opening <NUM> from the surrounding environment.

The fastener <NUM> may fixedly couple the sleeve <NUM> to the brake carrier <NUM>. The fastener <NUM> may have any suitable configuration. For instance, the fastener <NUM> may be configured as a bolt, such as a carriage bolt, that may be received in a fastener hole of the brake carrier <NUM>. For instance, the fastener <NUM> and the fastener hole of the brake carrier <NUM> may have mating threads. The fastener <NUM> may be partially received in the guide pin opening <NUM> of the caliper housing <NUM> and may extend along or around the guide pin axis <NUM>.

The sleeve <NUM> may receive the fastener <NUM>. For instance, the sleeve <NUM> may be configured as a hollow tube that may receive the fastener <NUM> and that may be at least partially received in the guide pin opening <NUM> of the caliper housing <NUM>. The hollow portion of the sleeve <NUM> that may receive the fastener <NUM> may be sized slightly larger than the fastener <NUM> so as to permit insertion and rotation of the fastener <NUM> for assembly purposes but may otherwise generally center the sleeve <NUM> about the guide pin axis <NUM>. The sleeve <NUM> may be fixedly positioned or stationary with respect to the brake carrier <NUM>. The sleeve <NUM> may extend from and may engage or contact the brake carrier <NUM>. Alternatively, the sleeve <NUM> may be separated from the brake carrier <NUM> by an intervening component.

One or more bushings <NUM> may be received or partially received in the guide pin opening <NUM>. A bushing <NUM> may encircle the sleeve <NUM> and may extend from the sleeve <NUM> to the caliper housing <NUM>. A bushing <NUM> may facilitate sliding of the caliper housing <NUM> along the guide pin axis <NUM> and with respect to the brake carrier <NUM>. For example, the bushing <NUM> may be slidable with respect to the sleeve <NUM>. A bushing <NUM> may have any suitable configuration. For instance, a bushing may be configured as a hollow cylinder.

One or more sealing components <NUM> may be provided to help separate the guide pin opening <NUM> from the surrounding environment. For instance, a sealing component <NUM> may inhibit contaminants such as particulates and moisture or water from entering the guide pin opening <NUM>, thereby helping maintain smooth sliding movement of the caliper housing <NUM> and inhibiting corrosion of internal components. A sealing component <NUM> may be completely received inside the guide pin opening <NUM>, partially received inside the guide pin opening <NUM>, or may be located outside the guide pin opening <NUM>. A sealing component <NUM> may have any suitable configuration. For instance, a sealing component <NUM> may be configured as a seal, such as an O-ring, that may encircle the sleeve <NUM> and may extend from the sleeve to the caliper housing <NUM> or and intervening component. Alternatively or in addition, a sealing component <NUM> may be configured as a cover, cap, boot, or the like. In the configuration shown in <FIG>, one sealing component <NUM> is configured as a cap <NUM> while the other sealing component is configured as a flexible boot <NUM>.

The cap <NUM> may be provided to cover the end of the guide pin opening <NUM> that faces away from the brake carrier <NUM>. In at least one configuration, the cap <NUM> may be received in the guide pin opening <NUM>. The cap <NUM> may partially receive the guide pin assembly <NUM>.

The flexible boot <NUM> may extend between the brake carrier <NUM> and the brake caliper <NUM> or between the guide pin assembly <NUM> and the caliper housing <NUM>. The flexible boot <NUM> may flex or change in length in response to movement of the brake caliper <NUM>. For instance, the flexible boot <NUM> may expand or unfold when the brake caliper <NUM> moves in a first direction with respect to the brake carrier <NUM> and may contract or fold when the brake caliper <NUM> moves in a second direction with respect to the brake carrier <NUM>.

Referring to <FIG>, the brake actuator <NUM> may be mounted to the brake carrier <NUM>. In at least one configuration, the brake actuator <NUM> may be mounted to the back wall <NUM> of the caliper housing <NUM> and may have a brake actuator shaft that may extend through the opening <NUM> in the caliper housing <NUM>. The brake actuator shaft may engage the operating shaft <NUM> and may be moveable to rotate the operating shaft <NUM>.

Referring to <FIG> and <FIG>, the operating shaft <NUM> may transmit force from the brake actuator <NUM> other moveable components of the brake assembly <NUM>. In at least one configuration, the operating shaft <NUM> may generally be configured as an inverted "Y" and may include a lever <NUM>, a pair of cams <NUM>, and a tab <NUM>.

Referring primarily to <FIG>, the lever <NUM> may extend from the cams <NUM> toward the opening <NUM> of the caliper housing <NUM>. The lever <NUM> may have a pocket that may receive an end of the brake actuator shaft.

The cams <NUM> may be spaced apart from each other such that a gap <NUM> is provided between the cams <NUM>. In at least one configuration, the cams <NUM> may have mirror symmetry with respect to each other. In at least one configuration, a cam <NUM> may include a concave recess <NUM> and a convex surface <NUM>.

The concave recess <NUM> may receive a corresponding roller <NUM>. The roller <NUM> may be supported by a corresponding arcuate surface in the cavity <NUM> of the caliper housing <NUM> and may be rotatable about a roller axis of rotation <NUM>, which is best shown in <FIG>.

Referring to <FIG>, the convex surface <NUM> may be disposed opposite the concave recess <NUM>. The convex surface <NUM> may engage a corresponding set of roller bearings <NUM> that may be disposed between the convex surface <NUM> and the yoke <NUM>. The rollers <NUM> and roller bearings <NUM> may facilitate rotation of the operating shaft <NUM> about an axis of rotation. The operating shaft axis of rotation may be disposed at a radial centerline of the convex surface <NUM>.

The tab <NUM> may extend from at least one of the cams <NUM> into the gap <NUM>. A ball pin <NUM> may be fixedly mounted to the tab <NUM> and may extend toward the wear adjuster mechanism <NUM> as will be discussed in more detail below. In at least one configuration, the ball pin <NUM> may have a generally spherical or rounded ball at its distal end.

The yoke <NUM> may be disposed between the operating shaft <NUM> and the piston <NUM>. In at least one configuration, the yoke <NUM> may include a concave surface <NUM>, an engagement surface <NUM>, and a through hole <NUM>.

The concave surface <NUM> may face toward the operating shaft <NUM> and may engage the roller bearings <NUM>.

The engagement surface <NUM> may be disposed opposite the concave surface <NUM>. The engagement surface <NUM> may engage or contact an end of the piston <NUM>.

The through hole <NUM> may be disposed proximate the center of the yoke <NUM> and may receive at least a portion of the wear adjuster mechanism <NUM>. The through hole <NUM> may extend around an axis <NUM>, which is best shown in <FIG>. The axis <NUM> may be offset from and may extend substantially parallel to the brake rotor axis of rotation <NUM>.

Referring to <FIG> and <FIG>, the tappet <NUM> may be moveable along the axis <NUM> with respect to the caliper housing <NUM>. However, the brake carrier <NUM> may inhibit or prevent the tappet <NUM> from rotating about the axis <NUM>. As is best shown in <FIG>, the tappet <NUM> may protrude away from the cavity <NUM> of the caliper housing <NUM> and may have a generally hollow body that may include an inner female thread <NUM> and an engagement face <NUM>.

The inner female thread <NUM> may face toward the axis <NUM> and may extend around the axis <NUM>.

The engagement face <NUM> may face away from the cavity <NUM>. The engagement face <NUM> may engage or contact a brake pad assembly <NUM>. For example, the engagement face <NUM> may engage or contact a side of the backplate <NUM> that may be disposed opposite the friction material <NUM>.

The piston <NUM> may be at least partially received inside the tappet <NUM>. The piston <NUM> may be moveable along the axis <NUM>. In addition, the piston <NUM> may be rotatable about the axis <NUM>. In at least one configuration and as is best shown in <FIG>, the piston <NUM> may have a hollow tubular configuration that may include an outer female thread <NUM>, at least one recess <NUM>, and an end cap <NUM>. The brake assembly <NUM> may be provided with a single piston <NUM> in one or more configurations.

The outer female thread <NUM> may face away from the axis <NUM> and may extend around the axis <NUM>. The outer female thread <NUM> may mate with the inner female thread <NUM> of the tappet <NUM>. As such, the tappet <NUM> and the piston <NUM> may have mating threads.

At least one recess <NUM> may be provided in an inner surface of the piston <NUM> that may be disposed opposite the outer female thread <NUM> and that may face toward the axis <NUM>. In the configuration shown, two recesses <NUM> are provided that are disposed opposite each other and extend the length of the piston <NUM>. The recesses <NUM> may facilitate mounting of a disc pack of the wear adjuster mechanism <NUM> as will be discussed in more detail below.

Referring to <FIG> and <FIG>, the end cap <NUM> may be disposed at an end of the piston <NUM> that may face toward the brake pad assembly <NUM> and the tappet <NUM>. The end cap <NUM> may be integrally formed with the body of the piston <NUM> or may be provided as a separate component. In the configuration shown, the end cap <NUM> is provided as a separate component that may be received in the hollow body of the piston <NUM>. The end cap <NUM> may be fixed to the piston <NUM> such that the piston <NUM> is not rotatable with respect to the end cap <NUM>.

Referring to <FIG>, the wear adjuster mechanism <NUM> may be configured to maintain a desired running clearance between the brake pad assemblies <NUM> and the brake rotor <NUM> when the brake pad assemblies <NUM> are retracted. As an overview, the wear adjuster mechanism <NUM> may include a one-way clutch that may permit the axial position of a brake pad assembly along the axis <NUM> to be adjusted or move closer to the brake rotor <NUM> in response to wear of the friction material <NUM>. The wear adjuster mechanism <NUM> may be provided in various configurations, some examples of which are disclosed in <CIT>. The wear adjuster mechanism <NUM> may be at least partially received inside the piston <NUM>. In at least one configuration and as is best shown with reference to <FIG> and <FIG>, the wear adjuster mechanism <NUM> may include a shaft <NUM>, a first bearing assembly <NUM>, a second bearing assembly <NUM>, a drum <NUM>, a disc pack <NUM>, a first biasing member <NUM>, and a second biasing member <NUM>.

The shaft <NUM> may be at least partially received in the cavity <NUM> of the caliper housing <NUM>. The shaft <NUM> may be disposed in the through hole <NUM> of the yoke <NUM> and inside the hole or cavity of the piston <NUM>. In addition, the shaft <NUM> may be spaced apart from the yoke <NUM> and the piston <NUM>. The shaft <NUM> may be rotatable about the axis <NUM> and may define a shaft cavity <NUM> and a ball pin engagement feature <NUM>.

The shaft cavity <NUM> may extend along the axis <NUM>. In at least one configuration, the shaft cavity <NUM> may be configured as a through hole that may extend along the axis <NUM> from a first end of the shaft <NUM> to a second end of the shaft <NUM> that may be disposed opposite the first end of the shaft <NUM>. A portion of the shaft cavity <NUM> that may be received inside the yoke <NUM> may have a larger diameter than a portion of the shaft cavity <NUM> that may be received inside the piston <NUM>.

The ball pin engagement feature <NUM> may be configured to engage the ball pin <NUM>. The ball pin engagement feature <NUM> may be disposed at an end of the shaft <NUM> that may face toward the operating shaft <NUM> and may be offset from the axis <NUM>. In the configuration shown, the ball pin engagement feature <NUM> is configured as a recess that may receive the ball pin <NUM>. The ball pin <NUM> may extend at an angle with respect to the axis <NUM> such that rotation of the operating shaft <NUM> may cause the ball pin <NUM> to engage a side or surface of the ball pin engagement feature <NUM> in a manner that may rotate the shaft <NUM> about the axis <NUM>. It is also contemplated that the ball pin engagement feature <NUM> may have a male configuration and the ball pin <NUM> may have a female configuration in other configurations.

The first bearing assembly <NUM> may rotatably support the shaft <NUM>. The first bearing assembly <NUM> may be disposed proximate a first end of the shaft <NUM> and may receive the shaft <NUM>. For instance, the first bearing assembly <NUM> may extend around the shaft <NUM> and may be received inside the piston <NUM>. As such, the first bearing assembly <NUM> may extend from the shaft <NUM> to or toward the inner surface of the piston <NUM>.

The second bearing assembly <NUM> may rotatably support the shaft <NUM>. The second bearing assembly <NUM> may be disposed proximate a second end of the shaft <NUM> and may receive the shaft <NUM>. For instance, the second bearing assembly <NUM> may extend around the shaft <NUM> and may be received inside the through hole <NUM> of the yoke <NUM>. As such, the second bearing assembly <NUM> may extend from the shaft <NUM> to or toward the yoke <NUM>.

The drum <NUM> may be received inside the piston <NUM> and may be spaced apart from the piston <NUM>. The drum <NUM> may extend around and may receive a portion of the shaft <NUM>. In addition, the shaft <NUM> may be selectively rotatable about the axis <NUM> with respect to the drum <NUM> as will be discussed in more detail below. In at least one configuration, the drum <NUM> may have a hollow tubular construction that may include at least one recess <NUM>. A plurality of recesses <NUM> may be arranged around an exterior side of the drum <NUM> that faces away from the axis <NUM>. The recesses <NUM> may facilitate mounting of the disc pack <NUM>. Axial movement of the drum <NUM> may be constrained by the shaft <NUM> and by a spacer <NUM> that may extend from an end of the drum <NUM> to the first bearing assembly <NUM>.

The disc pack <NUM> may selectively couple the piston <NUM> and the drum <NUM>. As is best shown in <FIG>, the disc pack <NUM> may include a plurality of discs that may include at least one outer disc <NUM> and at least one inner disc <NUM>. The outer discs <NUM> may have at least one tab <NUM> (best shown in <FIG>) that may be received in a recess <NUM> of the piston <NUM>. As such, the outer discs <NUM> may be rotatable about the axis <NUM> with the piston <NUM>. The inner discs <NUM> may have at least one tab <NUM> that may be received in a recess <NUM> of the drum <NUM>. As such, the inner discs <NUM> may be rotatable about the axis <NUM> with the drum <NUM>. The outer discs <NUM> and the inner discs <NUM> may be arranged in an alternating order in an axial direction or in a direction that extends along the axis <NUM>. For instance, at least one inner disc <NUM> may be axially positioned between two adjacent outer discs <NUM> or vice versa. The piston <NUM> may be rotatable about the axis <NUM> with the drum <NUM> when the discs of the disc pack <NUM> are sufficiently compressed such that the outer discs <NUM> and the inner discs <NUM> do not slip with respect to each other. Conversely, the drum <NUM> may be rotatable with respect to the piston <NUM> when the discs of the disc pack <NUM> are not sufficiently compressed or when the outer discs <NUM> and the inner discs <NUM> slip with respect to each other.

Referring to <FIG> and <FIG>, the first biasing member <NUM> may exert a biasing force on the disc pack <NUM>. The first biasing member <NUM> may have any suitable configuration. For instance, the first biasing member <NUM> may be configured as a spring that may extend from the first bearing assembly <NUM> to the disc pack <NUM> and that may exert a biasing force on the disc pack <NUM> in a direction that may extend toward the yoke <NUM>. As such, the first biasing member <NUM> may compress the discs of the disc pack <NUM>.

The second biasing member <NUM> may selectively couple the shaft <NUM> and the drum <NUM>. The second biasing member <NUM> may have any suitable configuration. For example, the second biasing member <NUM> may be configured as a wrap spring that may be axially positioned between the disc pack <NUM> and the second bearing assembly <NUM>. The second biasing member <NUM> may be partially received inside the yoke <NUM> and may be partially received inside the piston <NUM>. The second biasing member <NUM> may extend around the shaft <NUM> and may extend around a portion of the drum <NUM>. The second biasing member <NUM> may be configured to slip and allow the shaft <NUM> to rotate with respect to the drum <NUM> and the piston <NUM> when the brake is released or braking is disengaged as will be discussed in more detail below.

Referring to <FIG>, one or more retraction springs <NUM> may be provided to facilitate retraction of the brake pad assemblies <NUM>. A retraction spring <NUM> may be received in the cavity <NUM> of the caliper housing <NUM> and may extend from the yoke <NUM> to the cover plate <NUM>. The retraction spring <NUM> may be configured to actuate the yoke <NUM> away from the cover plate <NUM> since the cover plate <NUM> is fixed to the caliper housing <NUM>. As such, the retraction spring <NUM> may urge the yoke <NUM> to move along the axis <NUM> in a direction that extends away from the brake rotor <NUM> and the cover plate <NUM>.

Operation of the brake assembly <NUM> will now be described in more detail. As an overview, the brake assembly <NUM> may start in a retracted state in which braking of the vehicle is not requested. As such, the brake pad assemblies <NUM> may be retracted away from the brake rotor <NUM> and components of the brake assembly <NUM> may be positioned as shown. In response to a vehicle braking command, the brake actuator <NUM> may extend the brake actuator shaft, thereby rotating the operating shaft <NUM> about its axis of rotation in a first direction. Rotation of the operating shaft <NUM> may move the yoke <NUM>, tappet <NUM>, piston <NUM>, wear adjuster mechanism <NUM>, and the inboard brake pad assembly <NUM> that is disposed adjacent to the tappet <NUM> along the axis <NUM> toward the brake rotor <NUM>. Movement of the yoke <NUM> toward the brake rotor <NUM> may compress the retraction springs. In addition, rotation of the operating shaft <NUM> may cause the ball pin <NUM> to engage the ball pin engagement feature <NUM> of the shaft <NUM>, which may rotate the shaft <NUM> about the axis <NUM>. Once the inboard brake pad assembly <NUM> contacts the brake rotor <NUM> a reaction force may then move the brake caliper <NUM> with respect to the brake carrier <NUM> to actuate the outboard brake pad assembly <NUM> that is disposed between the brake rotor <NUM> and the caliper bridge <NUM> into engagement with an opposite side of the brake rotor <NUM> to help slow rotation of the brake rotor <NUM> and an associated vehicle wheel. Retracting the brake actuator shaft may allow the operating shaft <NUM> to rotate about its axis of rotation in a second direction, which in turn may allow the actuation sequence to proceed in reverse under the biasing force of the retraction springs.

Rotation of the operating shaft <NUM> may or may not result in adjustment of the running clearance between the brake pad assembly <NUM> and the brake rotor <NUM>. For example, rotation of the operating shaft <NUM> in the first direction may operate the wear adjuster mechanism <NUM> to extend the tappet <NUM> closer to the brake rotor <NUM> with respect to the piston <NUM> when the operating shaft <NUM> and the ball pin <NUM> rotate the shaft <NUM> about the axis <NUM> before the inboard brake pad assembly <NUM> contacts the brake rotor <NUM>. As such, the shaft <NUM> and the drum <NUM> may rotate together about the axis <NUM> due to the force exerted by the second biasing member <NUM>. Rotation of the drum <NUM> may cause the piston <NUM> to rotate about the axis <NUM> due to the coupling provided by the disc pack <NUM>. Rotation of the piston <NUM> may extend the tappet <NUM> (i.e., extend the tappet <NUM> further away from the yoke <NUM> and closer to the brake rotor <NUM>) due to the mating of the outer female thread <NUM> of the piston <NUM> and the inner female thread <NUM> of the tappet <NUM>. For example, rotation of the piston <NUM> may cause the tappet <NUM> to extend to the left from the perspective shown with respect to the piston <NUM> due to operation of the mating threads since the tappet <NUM> is inhibited from rotating about the axis <NUM> by the brake carrier <NUM>. Extension of the tappet <NUM> with respect to the piston <NUM> may stop when the inboard brake pad assembly <NUM> contacts the brake rotor <NUM>. For example, the torque required to rotate the piston <NUM> increases substantially when the inboard brake pad assembly <NUM> contacts the brake rotor <NUM> even when the brake actuator <NUM> continues to rotate the operating shaft <NUM> and hence continues to rotate the shaft <NUM>. As a result, the discs of the disc pack <NUM> may slip with respect to each other, thereby permitting rotation of the shaft <NUM> with respect to the piston <NUM>.

The wear adjuster mechanism <NUM> may operate to hold the tappet <NUM> in its adjusted position when the brake pad assemblies <NUM> are retracted. For example, when the brake actuator <NUM> is retracted the operating shaft <NUM> may rotate in a second direction that is disposed opposite the first direction, or clockwise from the perspective shown. The ball pin <NUM> may then rotate the shaft <NUM> in the opposite direction back to its previous rotational position. However, the force exerted by the disc pack <NUM> may exceed the force exerted by the second biasing member <NUM>. As a result, the disc pack <NUM> may inhibit rotation of the piston <NUM> about the axis <NUM> with respect to the drum <NUM> while the second biasing member <NUM> may slip or allow the shaft <NUM> to rotate about the axis <NUM> in the second direction with respect to the drum <NUM> and back to its previous position.

Rotation of the operating shaft <NUM> may not result in adjustment of the running clearance between the brake pad assembly <NUM> and the brake rotor <NUM> when the inboard brake pad assembly <NUM> contacts the brake rotor <NUM> before the operating shaft <NUM> and the ball pin <NUM> rotate the shaft <NUM> about the axis <NUM>. As previously discussed, the torque required to rotate the piston <NUM> increases substantially when the inboard brake pad assembly <NUM> contacts the brake rotor <NUM>. As a result, the discs of the disc pack <NUM> may slip with respect to each other as the operating shaft <NUM> rotates in the first direction, thereby permitting rotation of the shaft <NUM> with respect to the piston <NUM> while rotation of the piston <NUM> is opposed by the tappet <NUM> reacting against the brake rotor <NUM>. The wear adjuster mechanism <NUM> may operate to hold the tappet <NUM> in its current position when the brake pad assemblies <NUM> are retracted (e.g., the disc pack <NUM> may inhibit rotation of the piston <NUM> about the axis <NUM> while the second biasing member <NUM> may slip or allow the shaft <NUM> to rotate about the axis <NUM> and back to its previous position as previously described).

Referring to <FIG>, the cavity <NUM> inside the caliper housing <NUM> may be sealed from the surrounding environment to inhibit contaminants and moisture or water from entering the cavity <NUM>. For example, the brake actuator <NUM> and the cover plate <NUM> may directly or indirectly seal against the caliper housing <NUM>, such as with an intervening seal or gasket that may facilitate sealing of a corresponding opening of the caliper housing <NUM>. Similarly, a flexible boot <NUM> may extend from the tappet <NUM> to the caliper housing <NUM> and/or the cover plate <NUM> to provide sealing between the tappet <NUM> and the caliper housing <NUM> while accommodating movement of the tappet <NUM>. In addition, the hole <NUM> in the caliper housing <NUM> may receive a component such as a plug that may facilitate sealing as previously discussed.

Sealing of the cavity <NUM> may help prevent corrosion of components or surfaces inside the cavity <NUM> of the caliper housing <NUM>. For example, moisture inside the cavity <NUM> can lead to corrosion of components inside the cavity <NUM> that facilitate movement like the operating shaft <NUM>, yoke <NUM>, tappet <NUM>, piston <NUM>, wear adjuster mechanism <NUM>, rollers <NUM>, roller bearings <NUM>, or corrosion of surfaces that may support these components or that these components may move upon. A small amount of moisture may be present in the cavity <NUM> at the time of assembly due to water vapor in the air inside the cavity <NUM>. However, the amount of moisture in the cavity <NUM> may change if there is leakage or a leak path between the cavity <NUM> and the surrounding outside environment, between the guide pin opening <NUM> and the surrounding environment, or both. For instance, leakage may occur around or through the brake actuator <NUM>, cover plate <NUM>, flexible boot <NUM>, sealing component <NUM>, or the like during use. A leak path may allow water or additional water vapor to enter the cavity <NUM>, which may increase the potential for corrosion. Visual inspection of surfaces and components of the brake assembly <NUM> for a leak path and/or for corrosion is inherently subjective, is reliant upon the thoroughness of the visual inspection by an inspector, and is thus subject to error. In addition, visual inspection may require removal of a vehicle wheel to permit access by the inspector, extensive disassembly of the brake assembly, or both. Such steps may increase inspection times in associated costs. A pressure check device <NUM> may address some or all of these deficiencies.

Referring to <FIG>, an example of a pressure check device <NUM> is shown that facilitates checking of the sealing of the caliper housing <NUM>. The pressure check device <NUM> may include a fitting <NUM>, a pressure sensor <NUM>, and a communication device <NUM> and may be fluidly connected to a pressure adjustment device <NUM>.

The fitting <NUM> may be fluidly connectable to the cavity <NUM>. For instance, the fitting <NUM> may be received in the hole <NUM> in the caliper housing <NUM> when the pressure check device <NUM> is installed. The fitting <NUM> may be fluidly connectable to the pressure sensor <NUM> and the pressure adjustment device <NUM>.

The pressure sensor <NUM> may be fluidly connectable to the cavity <NUM>. The pressure sensor <NUM> may provide a signal, output, or response indicative of the fluid pressure or air pressure in the cavity <NUM>. The pressure sensor <NUM> may be of any suitable type, such as an electronic pressure sensor or a non-electronic pressure sensor. The pressure sensor <NUM> may be of any suitable type and may be disposed in any suitable location, such as between the cavity <NUM> and the pressure adjustment device <NUM>. As such, the pressure sensor <NUM> may be disposed outside the brake assembly <NUM> in one or more configurations.

The communication device <NUM> may provide information regarding the pressure inside the cavity <NUM>. The communication device <NUM> may be of any suitable type. For instance, the communication device <NUM> may produce an audible output, visual output, tactile output, or combinations thereof. Some examples of communication device <NUM> may include a display, light, speaker, haptic device, or combinations thereof. In at least one configuration, the communication device <NUM> may be a gauge that may have a digital or analog display that shows the pressure detected or measured by the pressure sensor <NUM>.

The pressure adjustment device <NUM> may provide negative pressure, positive pressure, or both. For instance, the pressure adjustment device <NUM> may provide negative pressure to extract fluid from the cavity <NUM> through a passage in the fitting <NUM>. Conversely, the pressure adjustment device <NUM> may provide positive pressure to provide fluid to the cavity <NUM> through the passage in the fitting <NUM> to increase the fluid pressure inside the cavity <NUM>. The fluid inside the cavity <NUM> may be a gas or gas mixture such as air; however, it is contemplated that another gas or gas mixture could be provided other than air like nitrogen gas, helium gas, an inert gas, or the like. The term "air pressure" may be used herein to generically reference air as the gas mixture or other gases or gas mixtures that may be provided to or exhausted from the cavity <NUM>. In at least one configuration, the pressure adjustment device <NUM> may be a pump or be connected to a pump that may be manually powered or non-manually powered.

Referring to <FIG>, a flowchart of a method of checking sealing of a caliper housing <NUM> is shown. This method may be employed with a brake assembly having a caliper housing <NUM> as previously discussed. The method may be employed during initial assembly of the brake assembly <NUM> by the manufacturer or by a technician during maintenance or inspection of the brake assembly <NUM>. In addition, the method may be employed when the brake assembly <NUM> is not operated to extend or retract the brake pad assemblies.

The method steps below are discussed in the context of the pressure check device <NUM> being fluidly connected to the cavity <NUM> of the caliper housing <NUM>, such as via the hole <NUM>. As such, installation of the pressure check device <NUM> is not included in the method steps.

At block <NUM>, the fluid pressure in the cavity <NUM> is changed. The fluid pressure may be changed with the pressure adjustment device <NUM>. For instance, the pressure adjustment device <NUM> may be connected to the fitting <NUM>. A valve may be opened and the pressure in the cavity <NUM> may be changed by either supplying air to the cavity <NUM> to increase the fluid pressure in the cavity <NUM> above the surrounding atmospheric pressure or by extracting air from the cavity <NUM> to decrease the fluid pressure in the cavity <NUM> below the surrounding atmospheric pressure. The change in pressure may be an amount that is outside the error range of the pressure sensor <NUM>. As an example, the pressure may be increased or decreased by <NUM> psi (<NUM> kPa) or more.

At block <NUM>, the sealing condition or sealing of the cavity <NUM> and the guide pin openings <NUM> is determined with the pressure check device <NUM>. The sealing condition is determined after the fluid pressure inside the cavity <NUM> has been changed. For example, the fluid pressure may be detected with the pressure sensor <NUM> and may be indicative of the pressure in the cavity <NUM> as well as in the internal passages <NUM> and the guide pin openings <NUM> that are fluidly connected to the cavity <NUM>.

At block <NUM>, the detected pressure may be evaluated to determine whether the detected pressure is stable. Stable pressure may be indicative of no leaks or a sufficiently sealed cavity <NUM>. For instance, the detected pressure may be stable when the pressure detected by the pressure sensor <NUM> is within a predetermined range after a predetermined period of time. The predetermined range may be based on the design tolerances of the pressure sensor <NUM>. As an example, the predetermined range may be ± <NUM> psi (<NUM> kPa) although larger or smaller ranges are contemplated if accommodated by the pressure sensor <NUM>. The predetermined period of time may be based on development testing. As an example, the predetermined period of time may be greater than <NUM> seconds, such as between <NUM> seconds and <NUM> seconds, and predetermined periods of time greater than <NUM> seconds are also contemplated. If the detected pressure is stable, then the method may continue at block <NUM>. If the detected pressure is not sufficiently stable, then the method may continue at block <NUM>.

At block <NUM>, the cavity <NUM> is considered to be adequately sealed or acceptably sealed since the detected pressure is sufficiently stable over or at the end of the predetermined period of time.

At block <NUM>, the cavity <NUM> and one or more guide pin openings <NUM> that are fluidly connected to the cavity <NUM> are not considered to be adequately or acceptably sealed from the surrounding environment since the detected pressure is not sufficiently stable over or at the end of the predetermined period of time. The presence of one or more leaks may allow pressurized gas in the cavity <NUM> to escape the cavity <NUM> and/or a guide pin opening <NUM> if positive pressure has been provided or may allow air from the surrounding environment to enter the cavity <NUM> and/or a guide pin opening <NUM> if negative pressure has been applied. The brake assembly <NUM> may then undergo further inspection or evaluation to determine the source of any leaks and to repair the leak or leaks.

At block <NUM>, the pressure in the cavity <NUM> may be reset to its previous state. For instance, if negative pressure was applied, then additional air may be provided to the cavity <NUM> to generally equalize the pressure in the cavity <NUM> with the surrounding atmospheric pressure. Similarly, if positive pressure was applied, then air may be exhausted from the cavity <NUM> to generally equalized the pressure in the cavity <NUM> with the surrounding atmospheric pressure. The pressure in the cavity <NUM> may be reset by providing or removing air via the pressure check device <NUM> or simply by removing the pressure check device and allowing air to pass through the hole <NUM> before closing or plugging the hole <NUM>.

Claim 1:
A method of checking sealing of a brake caliper housing (<NUM>), the method comprising:
providing a brake assembly (<NUM>) that has a brake caliper housing (<NUM>) that is slidable with respect to a first guide pin (<NUM>), wherein the brake caliper housing (<NUM>) comprises a body (<NUM>) that defines a cavity (<NUM>), a first guide pin opening (<NUM>) that receives the first guide pin (<NUM>), and a first internal passage (<NUM>) that extends from the cavity (<NUM>) to the first guide pin opening (<NUM>);
fluidly connecting a pressure check device (<NUM>) to the cavity (<NUM>);
changing a pressure of a fluid inside the cavity (<NUM>); and
determining a sealing condition with the pressure check device (<NUM>) after changing the pressure.