A quick glance for more safety

Vehicle operators must always walk on a tightrope: if brake pads and drums are changed too early, costs are incurred that could actually have been avoided. But if you neglect to check or don’t notice wear quickly enough, this could lead to dangerous situations on the road. “Our engineers’ idea was therefore to allow a quick visual check of the condition of the brake drum and brake lining at any time. All you need is a small torch,” explains Michael Schwarz, Head of the Patent and Trade Mark Rights Department at BPW Bergische Achsen. “Naturally, this saves a considerable amount of time and especially increases safety in vehicle operation.” So it is not surprising that even more than 30 years after the patent application, the brake drum wear indicator has become an integral part of day-to-day business in the transport industry.

At the beginning of the 1990s, BPW engineers developed a brake drum with a circumferential fold that extends down to the brake linings. A clever idea: the height of this fold precisely matches the maximum permissible brake drum wear. The lining is also shaped accordingly up to the wear limit in the adjacent area. “An inspection window in the cover plate allows you to visually check or very easily and clearly recognise the condition,” Michael Schwarz explains further. Very simple and quick: if the fold is still visible but the brake lining is no longer pronounced, only the lining needs to be replaced. However, if the fold is no longer visible then the brake drum needs to be replaced. To protect the inspection window itself from spray water and dirt, it is fitted with a rubber cover that is easy to open and can also be quickly closed again after inspection.

But BPW’s innovation has not only made it much easier to check the trailer for brake wear. The replacement of wear parts saves just as much time and is just as uncomplicated: together with the torque-limited axle nut, BPW’s ECO Technology provides servicing that is almost as fast as in Formula 1. This is possible as the friction linings cannot work their way into the brake drum due to the fold that is present around the circumference of the brake drum, which means that no edge is formed that makes it difficult to remove the brake drum. . The patent specification from back in 1992 states: “The invention thus kills three birds with one stone by allowing better control of brake lining wear and brake drum wear and at the same time eliminates the need to rework the brake drum during brake lining replacement.”

With more than eleven million units sold, BPW’s Drum brake ECO Drum has proven its reliability for towed vehicles over many years. Optimised friction pairing with the brake drum guarantees minimum wear and high performance. And the wear indicator allows a visual check in seconds – because safety comes first!