Gates is involved in the entire history of timing belts. It was in 1917 that Gates founder John Gates created the world's first rubber V-belt. Then, 28 years later, in 1945, Gates created the first timing belt using teeth to synchronise it with the gears.
The development of belts in the automotive industry
The first known timing belt was used in 1945, and the first belt-driven camshaft engine was invented in 1954 by the American Bill Devin. He built a Panhard Devin racing car with opposed air-cooled cylinders, using a Timing belt to drive the two overhead camshafts. This car won the Sports Car Club of America (SCCA) national championship in 1956.
The 1966 Pontiac in-line six was the first mass-produced vehicle to use an overhead camshaft engine driven by a timing belt. The Fiat 124 engine with twin camshafts, developed in the early 1960s, was also a pioneer in this field.
The first range of Synchronous belts featured a V-belt profile and tooth pitch. From this single size, a wide variety of constructions were developed to meet the requirements of light or heavy, low or high speed applications.
A wide range of Belt applications
The product has evolved into a complex range of pitches, profiles and constructions. A wide variety of pitches are now available to optimise drive design for different load and speed conditions.
Different tooth profiles have been developed to increase the transmissible power for a given belt size.
The MXL cross-section succeeded the DP standard. Imperial pitch trapezoidal profiles (MXL, XL, L, H, XH, XXH), still widely used today, are the historical profiles of timing belts.
Metric standards (T5, T10 and T20) then appeared, without significantly revolutionising transmissible power.
Metric pitches with wider teeth (AT5, AT10, AT20) were developed for applications with higher loads.
The HTD (circular teeth) and STPD (first curvilinear teeth) profiles were developed by Uniroyal (now Gates Rubber) and Goodyear respectively. Although similar, these systems were not compatible.
Subsequently, several manufacturers developed curvilinear and parabolic teeth optimised for high-speed power transmission, giving rise to the STS, RPP, MGT, etc. profiles.
Gates' Poly Chain® is currently the best performing Belt. Initially made from rubber, the driving belt was converted to polyurethane to increase the hardness of the teeth and the transmission capacity. Originally developed for Harley-Davidson, it has evolved from HTD to MGT parabolic teeth, then to GT2 versions with Kevlar®, Carbon and finally Volt antistatic cords.