Pneumatic two-handed safety system - has 5-2 way valve to give signal when two switches are actuated in given time and released

摘要

The pneumatic two-hand safety switching system comprises two manual switches (1, 2) which each give a signal when operated. These must both be operated within a given short time interval determined by a volume n14) and a throttle (13) to produce a final signal (at 26). A first signal is produced within the system if both switches are operated within the said time interval and a second signal if both switches are released. To produce both the first and the second signal, a 5/2-way valve (5) is provided. A filter (19) may be arranged upstream of the throttle whose pore size is such that it gradually clogs up.