A Brake Expander That Is More Cost Effective Yet Less Robust

A hydraulic expander is an integral part of a drum brake. Usually, this is a two-piece assembly, involving a cylinder housing and a pair of coaxial pressure pistons. The latter is mounted in the former and affixed to the brake support, which in turn is secured to the axle and/or wheel via a spring-loaded or axially mounted brake caliper. This type of system is ideally designed to provide hydraulic pressure on the linings of the drum to actuate a brake, which in turn applies braking power to the wheels. These systems are only applicable to drum brakes, and are usually limited to applications where space is at a premium.

Fortunately, the hydraulic expander is not the only type of brake mechanism in this niche. For instance, there are a variety of disc, sleeve, and calliper types available. In addition, there are also a host of other hydraulic components to consider. One such component is the adjusting screw. The adjusting screw can be thought of as a flange that engages the flange member of an associated brake shoe, enabling the shoe to expand. Its functions include acting as an actuating element in the expander-wedge mechanism 11, and transmitting movements to the flange members of the shoes.

There is a great deal of competition in this field. Some manufacturers offer a standard package, which includes the aforementioned adjusting screw and its accompanying retraction springs, a lube oil system, and a quick-closing valve. Others, like Knott, offer a more customizable package that comprises an adapter that allows you to choose from a wide range of flanged or sleeved brake shoes.

However, in this day and age of overpriced and underpowered vehicles, the brake expander is often overlooked in favor of a cheaper, less robust alternative. Besides, it's an intricate device that requires considerable expertise to install. As a result, the number of aficionados who are interested in the subject is limited. Thus, a better solution is needed. Accordingly, the present invention aims to address this need by offering a more cost effective yet more robust hydraulic expander. To do so, the expander-wedge mechanism 11 comprises a pair of cylindrical support surfaces, which are affixed to a brake support 10 via a thrust member 19 and a pair of coaxial pressure pistons. Each of the two pistons is attached to the other by an adjusting screw 12. An oversized variant of the same is affixed to the end of each piston, in the same manner.