Mechanical timers are used to actuate devices at the end of a specified time period. They do not require electrical power and can be stored for long periods of time.

Types of Mechanical Timers

There are several types of mechanical timers.

Clock timers open and close a circuit based on the position of internal or external clockwork.

Spring-driven timers use a spring and trip lever to generate mechanical action.

Dashpot timers pass compressed air or hydraulic fluid into or out of a contained space through an opening with a fixed or variable diameter.

Typically, smaller openings are used for longer time delays. Some mechanical timers provide a standard, analog clock display. Others include rotating number wheels. 

Specifications

Selecting mechanical timers requires an analysis of specifications and features. The minimum time is the shortest interval for which mechanical timers can be configured. By contrast, the maximum time is the longest, configurable time interval. Typically, timing ranges are measured in seconds or hours. Devices with analog clocks display time intervals accordingly.

Features

In terms of features, some mechanical timers include a combined counter/timer mechanism. Others provide an audible alarm or a dial indicator instead of rotating digits. Devices with double shafts are commonly available. Typically, these mechanical timers have a dual shaft on one side for dual inputs, or left and right shaft extensions for left and right inputs. Special shaft lengths, diameters, and “flat” configurations are available.

Mechanical timers differ in terms of materials and mounting methods. Some devices are compact, rugged, or corrosion-resistant. Others provide varying degrees of resistance to environmental factors such as operating temperature, vibration, and shock. In terms of mounting methods, some mechanical timers are flush-mounted, hand held, or portable. Others mount on panels, racks, or DIN rails. DIN is an acronym for Deutsches Institut für Normung (DIN), a German national organization for standardization.  

Applications

Most mechanical timers are used in sequential, automatic control applications where checking the completion of one operation causes the start of another process. Common applications include:

• automatic milling machines
• periodic lubrication
• animated shop-window displays
• staged start-up of pumps
• automatic presses
• industrial washing machines

Mechanical timers are also used in motors, blowers, lighting, and control valves as well as in banking, retail, irrigation, and general industrial applications.

Related Information

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Festo Corporation