A Hobson's joint or Hobson's coupling is a type of right-angle

constant-velocity joint Constant-velocity joints (also known as homokinetic or CV joints) are mechanical joints which allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or Backlash (e ...

; rods bent 90° are able to transmit torque around a corner because they are all free to turn in their mounting holes in both legs of the coupling. Hobson's joints are used to make

elbow engine An elbow engine is a piston-based steam engine typically fed by steam or compressed air to drive a flywheel and/or mechanical load. It is based on a mechanism known as a Hobson's joint. Although not commonly used today for practical purposes, it i ...

s, a novelty device, but also for practical purposes in tools and

shaft-driven bicycle A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel. Shaft drives were introduced over a century ago, but were mostly supplanted by chain-driven bicycles due to the gear r ...

gearing.

External links

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References

Gears Rotating shaft couplings {{mech-engineering-stub