AU667056B2

AU667056B2 - Sealing system for brakes

Info

Publication number: AU667056B2
Application number: AU26220/92A
Authority: AU
Inventors: R.J. Phillips
Original assignee: R J PHILLIPS
Current assignee: R J PHILLIPS
Priority date: 1991-10-02
Filing date: 1992-10-02
Publication date: 1996-03-07
Anticipated expiration: 2012-10-02
Also published as: AU2622092A

Description

6670U56

AUSTRALIA

Patents Act 1990 0* 0 COMPLETE SPECIFICATION INVENTION TITLE: SIE~ SYSTEM FOR BRAKES The following statement is a full description of this invention, including the best method of performing it known to me: TITLE OF~ THE INVENTION: Sealing System for Brakes FIELD OF THE INVENTION: This invention seals brake drumis, thus preventing water and dust from entering. This inventioni encompasses electric, hydraulic and air operated drum brakes as used on boat trailers, caravans and trailers.

Current designs of trailer brakes allow water and dust to enter the drum. These combined elements then rust and corrode the brake's workings, rendering themn Unsafe, inefficient and. eventually inoperable.

One pertinent example of how these problemns occur is found in the use of boat trailers.

To both launch and recover their respective vessels, boat trailers must ultimately be submerged in water (fresh or salt), thus imm-nersig the brakes also. The brakes, hot from working are instantly cooled, contracting and sucking water into the d rm and bearinlgs.

The aforementioned process of decay now begins. This has led to many boat trailers losing a wheel, creating potentially fatal situations, This invention keeps the drumn and bearings free from water and dust. This not only allows the mechanics of the braking systemn to work efficiently, but protects the bearings by providing a cleaner and safer environment.

*BRIEF SUMMARY OF THE INVENTION: This invention provides a sealing system adapted to seal brakes of various types as used on selected wheels of trailers, caravans and the like, wherein the sealing system comprises a seal having two arms being free to move away from the sealing faces at high revolutions per Minute, and wherein in use a rear portion of housing means protecting a brake is sealed by the sealing system to a front portion of the housing means protecting the brake from the effect of dust and/or water.

BRIEF DESCRIPTION OF THE DRAWINGS: In order to assist the understanding of the invention reference will be made to the drawn examples, Figure I and Figure 2.

Figure 1 is an example of one emnbodimnent of the invention.

Figure 2 is an example of a heavy duty embodimntt of the invention drawn in Figure 1.

DETAILED DESCRIPTION OF THE INVENTION: Most seals can only seal one surface, the purpose of which is to keep oil or grease in (This also provides the seal with lubrication). The new seal serves to keep water and dust out. In this invention a special seal is required. This is a combination of a lip and V seal, making it both compact, and able to seal two surfaces at the one time.

The lip part of the seal runs on plastic ring which has specific friction properties.

This will extend the life and efficiency of the seal. The lip part of the seal may run directly onto the backing plate but with a greatly reduced life expectancy. The V part of the seal runs against the vertical surface of the backing plate at low speeds, and lifts off the surface at high speeds, when sea_-ng is not critical because of centrifugal forces preventing water and dust from entering.

4 The seal is housed in the brake drum which is finned to aid cooling.

rings of various sizes are used to seal the following:

SS

backing plate to spindle cap to drum screws to cap studs to drum a Since the brake is now a sealed unit, a vent (10) is fitted to the backing plate A hose may be clamped to the vent and fastened in such a location as to eliminate the possibility of water and dust entering. This allows the brake to breathe as required.

The following text refers to Figure 2, except where specified.

-3- In this embodiment which is a heavy duty version of Figure 1, air has been introduced to cool the drum which now runs inside a sealed housing. This comprises a backing plate and front cover which houses a lip seal which runs on a low friction plastic ring located in the drum The seal is much smaller in diameter than the special seal shown in Figure 1. Accordingly the speed (meters per second) is much lower. This, combined with the fact that the seal is located in a much cooler position further away from shoe/drum contact, extends the life of the seal greatly. The seal itself is also protected with a V seal mounted in a carrier sealing the vertical surfaces of the front cover rings of various sizes are used to seal the following: o backing plate to front cover backing plate to spindle (14); cap to drum screws (11) to drum S'.o studs (12) to drum As this is a totally sealed unit, cooling is now required for the drum. Cool air enters via air inlet This is supplied from a clamped hose connected to a filter which is located k above water level. Cool air flows into a low pressure area of the drum. The air circulates through angled holes in the drum and is expelled out via the air exhaust in a high pressure area. This high pressure area is created by the drum acting as a pump inside the housing. The air exhaust also has a hose clamped to it, located above water level.

Claims

1. A drum brake sealing system adapted to seal brakes of various types as used on selected wheels of trailers, caravans and the like, wherein the sealing system comprises a first seal mounted on a drum, the first seal having an arm which is free to move away from a sealing face on brake-housing means at high revolutions per minute, and wherein in use a rear portion of housing means protecting a brake is sealed by the sealing system to a front portion of the housing means protecting the brake from the effect of dust and/or water.

2. A sealing system as claimed in claim 1, wherein the sealing system is located between a backing plate and a cover plate each forming part of the housing means.

3. A sealing system as claimed in claim 1, wherein the sealing system is located between a cover plate and a drum housing for the brake.

4. A sealing system as claimed in any one of claims 1 to 3, wherein the first seal is adapted to mate with and travel on a self-lubricating insert.

5. A sealing system as claimed in claim 1, substantially as described with reference to Figure 1. S

6. A sealing system as claimed in claim 1, substantially as described with reference to Figure 2. Dated this 10th day of January 1996 RODRIC JOHN PHILLIPS By his Patent Attorney By his Patent Attorney MURRAY COMPANY