Post: The history of shock absorbers

A design with hydraulic damping was proposed in 1901, but it would only work in one direction. It does not seem to have been put into production immediately, and mechanical shock absorbers such as the Gabriel Snubber began to be installed in the late 20th century (there is also the similar Stromberg Anti-Shox). These used a belt that was rolled inside the unit, allowing it to wind freely under the action of the coil spring, but encountering friction when pulled out. Gabriel Snubbers were installed on the 11.9HP Arrol-Johnston racing car that broke the Brooklands 6-hour Class B record in late 1912, and Automator magazine noted that such a damper might have a good future in racing due to its light weight and ease of installation.
One of the first hydraulic shock absorbers to go into production was the Telesco shock absorber, which was shown at the 1912 Olympia Motor Show and sold by Polyrhoe Carburettors Ltd. It contained a spring inside the telescoping unit, like the pure spring “shock absorber” mentioned above, and oil and internal valves so that the oil could produce damping in the rebound direction. The Telesco unit was mounted to the rear end of the leaf springs, replacing the rear springs in the chassis mounts, so it became part of the spring system, albeit a hydraulically damped section. This arrangement was presumably chosen because it was easy to apply to existing vehicles, but it meant that hydraulic damping was not applied to the action of the main spring, but only to the action of the auxiliary springs on the unit itself.
One problem with cars was the large difference in spring weight between light and fully loaded, especially the rear springs. The springs could bottom out when heavily loaded, and attempts were made to smooth out the lightly loaded ride by using heavy main and auxiliary springs, often called “shock absorbers”, in addition to fitting rubber “shock absorbers”. These auxiliary springs were designed to have different periods, given that the spring and vehicle combination rebounded at a characteristic frequency, but this did not solve the problem of the spring rebound throwing you out of your seat after hitting a bump. What was needed was damping to act on the rebound.
The first hydraulic shock absorbers to act on the movement of the main springs were probably those based on the original concept patented by Maurice Houdaille in 1908 and 1909. They used a lever arm to move hydraulic damping blades inside the unit. Its main advantage over friction disc shock absorbers was that it resisted sudden movements but permitted slow movements, whereas rotary friction shock absorbers tended to stick and then offered the same resistance regardless of the speed of movement.The commercialization of lever-arm shock absorbers does not appear to have made much headway until after World War I, after which they were widely used, for example as standard equipment on the 1927 Ford Model A, manufactured by the Houde Engineering Company of Buffalo, New York.