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GENERAL PURPOSE STACK SWITCHES

click here to download a schematic drawing
(you will need to have Adobe Acrobat installed on your system to do this)

Complete general purpose stack switch assemblies are made from a pile-up of various actuator springs, contact springs and lifters. These stack switch assemblies can be used on manually operated control devices where switching is operated by cams, push-buttons and other similar mechanical devices. The stack switch assembly is made up of an actuator spring and various contact springs. These current carrying members are insulated from each other by phenolic spacers with plastic tubing press fitted through the stack; thereby insuring correct alignment of contacts and providing high insulation resistance when mounted.
The types of General Purpose Stack Switch Components available are:
* .375 inch (9.52 mm) mounting centers
* .250 inch (6.35 mm) mounting centers
* "Tini-Stack" Switches .188 inch (4.78 mm) mounting centers
* Telephone Relay Type Switches
.250 inch (6.25 mm) mounting centers
Stack Switch Components
Switchcraft offers various stack switch components, such as contact springs, spacers, lifters, etc., in many lengths, thicknesses, mounting centers and other details.
Switchcraft can assemble components into innumerable different stack switch assemblies. It is impossible to catalog every type of stack that has been manufactured. Stack switch assemblies can be designed to meet UL requirements, but only as part of equipment.
.375 Inch STACK SWITCHES
Thousands of switching combinations are possible. Switch mounting centers are .375 inch (9.52 mm) (minimum) with .25 inch (6.35 mm) wide switch parts. Practical spring length is 2.625 inches (66.68 mm) (maximum). Contact Switchcraft for selection of contacts and ratings.
MINIATURE .188 Inch (4.78 mm) STACK SWITCHES
Many Tini-Stack® switching combinations are possible. Switch mounting centers are .188 inch (4.78 mm) (minimum). Practical spring length is 1.750 inch (44.45 mm) (maximum).
SPECIFICATIONS
Springs: Copper alloy, in most standard gauge thicknesses ranging from .006 inch (0.15 mm) to .016 inch (0.41 mm).
Spacers: Rigid plastic, available in thickness of .015 inch (0.38 mm), .032 inch (0.81 mm) and .046 inch (1.17 mm).
Contacts: Welded cross bar palladium rated at 2A, 200W AC non-inductive load. Gold alloy generally recommended for "dry" circuit applications.
Tubing: Thermoplastic.
Lifters: Thermoplastic.
Mounting Hardware: Pressure plate, twin nut and screws: Steel, plated.
.250 Inch (6.35 mm) Inch STACK SWITCHES
Thousands of switching combinations are possible with slightly smaller parts. Mounting centers are .250 inch (6.35 mm) (minimum) with .188 inch (4.78 mm) wide parts. Practical spring length is 2.125 inches (53.98 mm) (maximum). Contact Switchcraft for selection of contacts and ratings.
TELEPHONE RELAY TYPE SWITCHES
Compact stack switches are particularly suitable for low activating force, such as in relay and magnetic operated devices. Contact Switchcraft for selection of contacts and ratings.
SPECIFICATIONS
Springs: Copper alloy, in thicknesses ranging from .006 inch (0.15 mm) to .012 inch (0.30 mm).
Spacers: Rigid plastic is standard in thickness of .031 inch (.79 mm), .047 inch (1.19 mm) and .063 inch (1.60 mm).
Contacts: Fine silver or welded cross bar palladium are standard. Palladium or gold alloy are generally recommended for "dry" circuit applications. Other contacts available for varied customer requirements on special order.
Tubing: Thermoplastic.
Lifters: Thermoplastic.
Bracket: Plated.
Mounting Hardware: Pressure plate, twin nut and screws: Steel, plated.

1. SPRINGS - Copper alloy in most standard gauge thicknesses of .006 (0.15 mm), .008 (0.20 mm), .010 (0.25 mm), .012 (0.30 mm), .016 (0.40 mm) and .020 inch (0.50 mm), a few designs can be made up to .031 inch (.079 mm) thick. All or any contact point hole can be provided; spring can be cut at any point.
2. BRACKETS - Standard brackets are detailed on drawing. Tools are flexible so that various lengths from same width stock can be provided.
3. LIFTERS OR PUSHERS - .125 inch (3.18 mm) and .188 inch (4.78 mm) diameter thermoplastic in various lengths staked into one of the contact point holds provides tandem action between blades or to serve as an actuator.
4. MOUNTING HARDWARE - Pressure plates (S1293 and S2300) twin nuts (S1008 and S1431) and screws available for mounting.
5. LEAF INSULATORS - Punched in same shape as springs in .015 inch (0.38 mm) thickness of fish paper or mylar.
6. SPACERS - Rigid plastic is standard in thicknesses of .015 (0.38 mm), .032 (0.81 mm), .051 (1.30 mm) and .062 inch (1.57 mm). Thickness of .093 inch (2.36 mm) is available for .375 inch (9.52 mm) mounting centers only. For longer surface creepage paths, use both large and standard sized spacers. High temperature insulation also available.
7. THERMOPLASTIC TUBING - .375 inch (9.52 mm) mounting centers pass #5 screw. .250 inch (6.35 mm) mounting centers pass #3 screw. .188 inch (4.78 mm) mounting centers pass #2 screw.
8. CAM FOLLOWERS - Two roller bracket designs (G1734 and G2298) available for springs .250 inch (6.35 mm) wide. Copper alloy standard. Can be furnished in various diameters and materials. Thermoplastic rollers also available.
9. CONTACTS - Welded cross bar contacts are commonly used for cost savings. However, riveted contacts are available. Size and material depend on circuit requirements (supply complete details). For low level audio circuits, we suggest gold alloy or palladium cross bar contacts. Springs can be bifurcated (two contacts per spring).
HOW TO ORDER STACK SWITCHES
Careful consideration of the following suggestions will help specify the most economical and expeditious approach to your switching needs. On initial inquiry or order, supply the following information:
1. Simple sketch or drawing. See "Typical Stack Assembly" drawing. Give details checked that are available.
2. Current, voltage and type of switching load (resistive or inductive).
3. Frequency of operation; life requirements.
4. Details of actuator.
5. Maximum and minimum movement of actuator blade.
6. Any other important specifying details.
It is recommended that data indicated above be forwarded to Switchcraft for comments and recommendations before finalizing your design.

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