Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

278 Chapter 11 Proprioceptive and Environmental Sensing Mechanisms and Devices
Figure 11-9
By-pass linear
By-Pass Layouts
The by-pass layout shown in Figures 11-9 and 11-10 relieves the switch
of taking any force, but, more importantly, is less sensitive to slight variations
in the positions of the switch and the sensed object, especially if a
switch with a long throw is used. Removing the hazard of impact and
reducing sensitivity make this layout both more robust and less precise.
With careful design, however, this layout is usually a better choice than
the previous layout because it requires less precision in the relationship
between the hard stop and the switch’s lever or button. Remember that
the object being sensed can be anything that is close to the robot, including
the ground.
This layout and its derivatives are the basis of virtually all mechanical
timers. They are still found in dishwashers, washing machines, and any
device where turning the knob results in an audible clicking sound as the
arm or button on the switch jumps off the lobe of the cam. They can be
stacked, as they are in appliances, to control many functions with a sin-