Snap Action Switches Technical Guide Switch construction These basic principles apply to all our precision switches. The specific Single-pole changeover switch (i.e. 83 161) characteristics of each model are given in more detail in the relevant production sections. Push button Case Mounting hole Introduction Our switches are high-precision, snap-action Terminal NC n2 switches and these are a few of the key Return spring features which distinguish our switches: Contact mobile -High ratings with small dimensions Contact fixed -Very short travels Terminal NO n4 Mounting hole - Low operating forces -Highly dependable force and travel values - Long life Common terminal C n1 - Large range of actuators for easy Pivot point adaptation to the most varied applications Blade Electrical function SPDT (C) Normally closed (NC) Normally open (NO) 2 12 14 14 Double-pole changeover switch (i.e. 83 132 0) Push button Blade Case Contact fixed Terminal NO n3 Terminal NO n4 Contact mobile Terminal NC n1 Terminal NC n2 Mounting hole Mounting hole Return spring Electrical function SPDT (C) Normally closed (NC) Normally open (NO) 34 3 4 12 12 The NO and NC circuits must both be of the same polarity. Products and specifications subject to change without notice. Order/Technical Support Tel: (800) 677-5311 / FAX: (800) 677-3865 / www.crouzet-usa.com 3/104Snap Action Switches Technical Guide Mechanical characteristics Terminology - Forces - Positions - Travel OF TTF RF RP TP OL RLP OF Operating Force TTF Total travel force RF Release force Force required to displace the operating Force to which the operating force must Maximum force which must be applied to device from its rest position RP to its be reduced to allow the snap-action the operating device to displace the rest overtravel limit position. (We only specify mechanism to return to its release position RP to the tripping point TP. this value if it is higher than the operating position RLP. force. When not quoted, it is equal to or less than the operating force). MOF Maximum overtravel force The maximum force which can be applied to the operating device, without damaging it, in the end of travel position 3 where it is in abutment internally or against the face of the case. RP Rest position TP Tripping point RLP Release position OL Overtravel limit Position of the operating device Position of the operating device relative Position of the operating device at the Position of the operating device when an when no external mechanical force is to the fixing point (hole, face) at the moment when the snap-action mechanism extreme force has moved it to the trips on its return to its original position. applied. Also described asheight at moment when the microswitch trips. effective end of the available travel. res. PT Pre-travel OT Overtravel DT Differential travel Distance between the rest position RP Distance between the tripping point TP Distance between the tripping point TP and the tripping point TP. and the overtravel limit OL. and the release position RLP. The reference point for the figures given for travel and forces is a point F situated on the button in the case of a plain microswitch, or, generally, 3 mm in from the end of a plain actuator. The reference point for the positions is one of the fixing holes, unless otherwise indicated. Graphs of forces vs. travel Contact force Operating force (external) applied to the operating device Force after depression: depression return return outward Button movement Contact force Products and specifications subject to change without notice. Order/Technical Support Tel: (800) 677-5311 / FAX: (800) 677-3865 / www.crouzet-usa.com 3/105 Electrical Travel Positions Forces Position of pushbutton circuit PT OT DT