FIELD OF THE INVENTION

The invention relates to automotive brakes and, in particular, to dust inhibiting and cooling devices for automotive brakes. More particularly, the invention relates to an anti-dust cooling device or fan for automotive drum brakes. The invention falls within the scope and inventive endeavor of mechanical engineering and will be of particular interest to the automotive industry.

BACKGROUND OF THE INVENTION

Rear disk brakes may be in common usage today. However, the vast majority of new cars and trucks still utilize rear drum brakes, since car manufacturers benefit from the lower cost of drum brakes to maintain the purchase price for a new vehicle at an attractive level for consumers.

Although the technology used in drum brakes has significantly improved over the last twenty years there remain flaws in the design of drum brakes, which have not yet been fully addressed or resolved. For example, under extreme braking conditions such as, for example, repeated high speed slow-downs, which, for example, may occur on a highway, or descent of a steep hill with a heavy load, the drum brakes are known to often fade and loose effectiveness, the consequence being the inability to arrest or slow down the vehicle as desired. The accepted explanation for such failure to adequately perform under certain braking conditions, was heat build up under the drum covering the brake system. It is known in the art that the performance of the brake is directly related to its capability of absorbing heat in the operation of the vehicle. If the brake becomes saturated with heat, the brake will no longer work efficiently. Thus, there is a need to provide a system and method for cooling the drum brake of a vehicle in order to avoid the undesired build up of heat under the drum which can readily be observed under certain braking conditions. Another problem with drum brakes is potential brake lock up which can occur under cold, and/or damp or humid conditions, especially when the brakes have remained inactive for a long period of time in, for example, heavy rain or very humid or cold weather. This type of lock up, as a rule, happens at low speed after initially moving the vehicle and during the first few stops. The low speed lock up of the brakes is believed to be mainly caused by the mixture of dust accumulated inside the drum and deposited on the surface of the brake and the moisture in the air. Accordingly, there is a need for a system and method that is adequate to prevent the low speed lock up described above, by effectively exhausting at least the majority of dust from the drum brake and, thus, maintaining the surface of the brake in a clean condition. It is believed that by reducing the build up of dirt and grime under the drum of the drum brake, the undesired lock up can be either prevented or at least inhibited.

There have been various developments within the prior art, whereby attempts have been made to provide dust-preventing and cooling devices for automotive brakes. For example, United States Patent No.6,371 ,569 to Dean issued April 16, 2002 describes a dust cover for placement between a wheel and brake assembly for preventing dust from the brakes to fall upon the wheel rim. The dust cover for placement between a wheel and brake assembly includes a plate having a front side, a back side and a peripheral edge. The front and back sides generally have a circular shape. The plate has an aperture therethrough. The aperture is generally positioned in a central portion of the plate and has a size adapted for receiving the hub of a vehicle.

United States Patent No. 6, 155,650 to Barger issued December 5, 2000 describes an anti-dust and cooling cover adapted for being positionable between a wheel and a brake assembly of a vehicle, such as an automobile, a truck, a sport utility vehicle, and the like, and being in rotation with the wheel and the brake assembly. The cover comprises a flat, circular plate and a cylindrical wall, and is adapted to be in communication with and to substantially surround the assembly.

United States Patent No. 5,671 ,827 to Demetriou, et al. issued September 30, 1997 describes a disc brake apparatus comprising an annular brake disc carried by a wheel hub rotatably mounted on an axle, the brake disc being constructed of circular friction plates spaced by a plurality of vanes extending radially along an inner face of the friction plates for enhancing flow of air past the disc and for enhancing dissipation of heat from the disc. A caliper brake assembly is mounted on a stationary support, the caliper brake assembly including a caliper housing, a pair of pistons mounted in the caliper housing and a diaphragm mechanism mounted adjacent and engaging the pistons. A brake pad assembly including brake pads is mounted adjacent to the pistons on the caliper housing and a source of pressurized air communicating fluid pressure from an outside source to the caliper assembly causes an application of force to the brake pad assembly by the pistons so that the brake pads engage with opposite radial faces of the brake disc.

United States Patent No. 4,484,667 to Bottieri, Jr. issued November 27, 1984 describes a dust shield plate which is clamped between the spider of an automotive vehicle wheel and the rotor of a disc brake for that wheel. The plate covers the axially inboard side of the wheel spider and prevents dust given off by the disc brake from getting on the wheel at the axially outboard side of the wheel spider. The shield plate has a circular peripheral edge which slidably engages the inside of the wheel at its tire-supporting rim and circumferentially spaced slits extending inward from this edge to provide flexible and resilient fingers in succession along the periphery. This enables the shield plate to be slidably inserted into wheels with somewhat different inside diameters. The shield plate has seven arcuate openings enabling it to be mounted on a wheel with four or five wheels studs or four wheels studs and two guide pins.

United States Patent No. 4,005,768 to Bubnash, et al. issued February 1 , 1977 describes a dust shield for a disc brake which has an arcuate portion positioned adjacent an annular braking surface of a disc brake rotor. The arcuate portion of the shield has a plurality of ventilation holes with an annular lip at the periphery of each hole. A plate extends across the arcuate shield portion and is spaced apart from the annular lips. The dust shield permits air to flow about the rotor for cooling purposes while reducing the contamination of the braking surfaces of the rotor by dirt particles carried by splashed road water and air. The prior art devices, while fulfilling their respective particular objectives, are known to suffer from issues pertaining to their structure and use or operation. The invention herein has, thus, been devised with a view to minimizing or, where possible, overcoming the issues surrounding the prior art designs of covers for the brake system of automobiles.

SUMMARY OF THE INVENTION

It is an object of the present invention to address the deficiencies found within the prior art by providing a brake drum anti-dust cooling device. The present invention seeks to minimize or overcome the aforementioned deficiencies by the nature of its design.

According to an embodiment of the present invention there is provided, a drum brake including a bearing hub assembly and a brake drum cover, the drum brake comprising a device for inhibiting the penetration of dust or other particles into the brake drum and for cooling the brake drum, the device comprising a plate and a wall extending from a surface of the plate so as to form a drum-like member for closely covering the bearing hub assembly, the plate being provided with a central opening for permitting the spindle portion of the vehicle's axle to pass through the central opening and a plurality of openings spaced around the central opening, each of the plurality of openings being dimensioned for permitting a corresponding wheel stud attached on the bearing hub assembly to pass through each of the plurality of openings in the plate and then through a corresponding opening in the brake drum cover for allowing a vehicle's wheel to be rotatably attached to the brake drum and the vehicle's axle, and the cylindrical wall being provided with a plurality of spaced apart means for creating an airflow inside the brake assembly, when the vehicle is in motion, for inhibiting the penetration of dust or other particles into the brake drum and for cooling the brake drum. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further understood from the following detailed description of preferred embodiments, having regard to the accompanying drawings, in which:

Figure 1 is a front plan view of a vehicle left side rear drum brake assembly having a brake drum anti-dust cooling device installed thereon according to an embodiment of the present invention ;

Figure 2 is a front plan view of a vehicle right side rear drum brake assembly having the brake drum anti-dust cooling device installed thereon according to an embodiment of the present invention ;

Figure 3 is a partially exploded perspective view showing a drum break assembly with a brake drum anti-dust cooling device in accordance with an embodiment of the invention; and

Figure 4 is an exploded perspective view showing a strut-type suspension portion of a vehicle and a drum break assembly with a brake drum anti-dust cooling device in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A better understanding of the present invention and its objects and advantages will become apparent to those skilled in this art from the following detailed description, wherein there is described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of modifications in various obvious respects, all without departing from the scope and spirit of the invention. Accordingly, the description should be regarded as illustrative in nature and not as restrictive.

Figs. 1 and 2 illustrate a plan view from the left side and right side, respectively, of a brake drum assembly with the anti-dust cooling device or annular fan 1 installed over a vehicle's axle 10 extending through a backing plate 30. The anti-dust cooling device 1 includes a plate from which a cylindrical wall extends so as to form a drum-like member suitable for installation through one end of the rear axle 10. The anti-dust cooling device 1 is shaped and dimensioned to cover the bearing hub assembly of the drum brake. The anti-dust cooling device 1 includes a plurality of openings through which the wheel studs 18 extend outwardly through openings in the brake drum 20 for securing the vehicle's wheel. Also shown in Figs. 1 and 2, are primary and secondary braking shoes 12 and the cylinder assembly 11 of the brake system. A star wheel adjusting assembly 14 includes an adjusting arm 16 and adjusting cable 15 which is connected to the anchor pin 13. The adjusting cable passes through an adjusting cable guide 17. Shown in Fig. 1 is the anti-dust cooling device 1 manufactured for attachment on the left side of a vehicle for rotation in the direction of the arrow. A similar anti-dust cooling device 2 for attachment of the right side of a vehicle, shown in Fig. 2, is constructed as a mirror image of the device 1.

Referring to Fig. 3, shown is a perspective view of the brake assembly with the anti- dust cooling device 1 covering the end of the rear axle 10 with the studs 18 extending through holes or orifices provided in the plate portion of the anti-dust cooling device 1. A brake drum 20 is shown as being positionable over the anti-dust cooling device 1 , between the anti-dust cooling device 1 and the wheel.

Figure 4 illustrates an exploded view of the brake assembly with the anti-dust cooling device or fan 1 positionable between the bearing hub assembly 22 and the brake drum 20. As one skilled in the art will be aware, a drum brake for use in the breaking system of a vehicle includes a backing plate 30 adapted to be mounted on a non-rotatable part of the vehicle, such as, for example, the knuckle 28 of the strut 29. An inner seal 24 is positioned around the spindle portion 25 of the vehicle's axle 10, which passes through a median orifice in the backing plate 30 for connection to the revolving bearing hub assembly 22. The hub assembly 22 has a plurality of wheel studs 18. In the embodiment illustrated in Fig. 4 there are five wheel studs. Openings or orifices in the plate of the anti-dust cooling device 1 can be provided for the wheel studs so that the anti-dust cooling device 1 is positionable closely between the bearing hub assembly 22 and the brake drum 20 for rotation therewith. A washer 27 and a retaining nut 26 threaded on the axle spindle 25 are provided for removably connecting a dust cap 23 provided for preventing the entering of dust and other particulate matter inside the drum brake assembly. Fig. 4 illustrates the anti-dust cooling device 1 according to an embodiment of the invention. The anti-dust cooling device 1 includes a plate 2 from which a cylindrical wall 3 extends so as to form a drum-like member suitable for installation over the bearing hub assembly 18. The plate of the anti-dust cooling device 1 includes a central opening for permitting the spindle portion 25 of the vehicle's axles 10 to pass through so that the anti-dust cooling device 1 closely surrounds the bearing hub assembly 18. A plurality of openings can be provided in the plate 2 for permitting the studs 18 to pass through the plate of the anti-dust cooling device 1 and through the opening in the brake drum 20 so as to allow the vehicle's wheel to be rotatably attached thereto. A plurality of vanes 6 can be provided on the outer surface of the cylindrical wall 3 for creating an air flow inside the brake assembly for preventing or minimizing the accumulation of dust or debris inside the brake assembly and for cooling the brake assembly when the vehicle is in motion.

In operation, when the vehicle is in motion, the vehicle's wheel, the brake drum 20, the anti-dust cooling device 1 , and the bearing hub assembly 22 rotate. The anti-dust cooling device 1 by virtue of rotating inside the brake assembly is believed to operate by creating an imbalance of air inside the brake assembly causing a minor turbulence or vortex within the break drum forcing or preventing the dust and other particulate matter outside the brake assembly. A drilled opening can be provided in the backing plate so as to assist the air flow inside the brake assembly in accordance with an embodiment of the invention.

Advantageously, due to the reduction in dust and moisture particles that can adhere to the brake assembly, the invention can be useful to reduce or eliminate the appearance of brake noise, which can be defined as a high pitch squeal that occurs at low speed (below 20 mph). While the brake noise cannot be considered as indicative of the brake system locking up or being in danger of doing so, the brake noise can be inconvenient to the driver and/or passengers, as well as the other participants in the traffic.

INDUSTRIAL APPLICABILITY The present invention provides an anti-dust cooling device or fan for automotive drum brakes. Benefits derived from the use of the present invention can be enjoyed, for example, in the construction of automotive vehicles, in particular, drum brake assemblies for automotive vehicle and the service and maintenance thereof by service professionals.