Schob pendulum

In fact, these values correspond to those for the well known Lupke pendulum and also for a modified version of the Schob pendulum. 

Figure 9-6. Rebound resilience apparatus, (a) Lupke pendulum (b) Schob pendulum (c) Dunlop pendulum (d) Goodyear-Healey pendulum (e) tripsometer (m = off-centre mass) (f)...

At the time of writing, there is an ASTM project to produce a standard for the Schob pendulum which seems to be making slow progress. The draft has little detail of the pendulum dimensions, which is probably so that the standard will encompass the two (at least) versions of the apparatus that have existed. 

Nechiporenko41 used a novel approach of repeated impact testing to obtain fatigue life under circumstances that would be relevant to tyres in quarries. He used a Schob pendulum with automatic delivery and counting of impacts, and needed only tests at two energies with up to 150 blows to give a rapid test. 

ASTM D105410 now specifies only the Goodyear-Healey pendulum (it previously also included the Schob). The Goodyear-Healey is a simple pendulum consisting of a rod mounted on ball races with an additional mechanism for measuring the depth of penetration of the indentor. A note... 

ISO 4662 details testing by the pendulum method. There are a number of different machines that conform to the specifications for impacting mass, velocity, and the apparent strain energy density. The types of suitable instruments mentioned in the specification include the Liipke, Schob, and Zerbini. Some modern instruments have electronic outputs giving either digital or printed results. 

---