Cam switch

Last updated
Cam Switch.jpg

Cam switches are mainly used within the low voltage range. On a shaft, switching cams are made of abrasion-resistant conductive material. By rotating the shaft, the contacts are opened or closed by the cams. Often, a plurality of cams are seated on a shaft, which simultaneously switch or switch several pairs of contacts. [1]

History

Friedrich Natalis (1864–1935), who had been working for the Schuckert-Werke (later Siemens-Schuckertwerke) since 1897, had already developed the cam-switching principle in Germany before 1900. In 1895, however, Johann Sigmund Schuckert founder of the electrical engineering company Schuckert & Co supplied cam switches with cam rollers and spring-loaded individual switches (DRP 88586). Thus the term cam switch has been used for such and similar devices over the years. Schuckert also supplied the "carbon control switch" designed by Natalis since 1901 with copper-carbon switching devices with spark-blowers (common spark blowers for direct current or single-spark blowers for direct and alternating current). The main current cam switch retained some significance, even when the rifle control pushed it where it was more economical. In miniature machine construction, the cam switch probably did not appear until the early 1930s. In 1931 the American company General Electric GE released their switch SBl, a 20A auxiliary current control switch, basically a miniaturized image of the large main current control switches. The devices had simple interruption and silver crossover, in some cases they were equipped with a snap mechanism. In Europe around 1940, the first cam switch from Ghielmetti, Solothurn / Switzerland, began to replace conventional roller switches. Switches could also be supplied as auxiliary current control switches with corresponding circuits. They were marketed under the trade name Ghielmetti-Clavier. In September 1948, Kraus & Naimer (of Vienna) produced C15 (15 A), the first company-owned cam switch. In 1949, the company also presented the world's first cam-designed cam switch. At the beginning of 1950, Kraus & Naimer cam switches C30 (30A) were followed with the same design. The Kraus & Naimer cam switches C16 to C200, which came into the market in the spring of 1951, had a decisive influence on the advancement of the cam switch and the introduction of the roller switch in electrical engineering. They had a double interruption and a motor switching capacity appropriate to the rated current. The large number of possible combinations and the extensive additional equipment as characteristic features were responsible for the later development of cam switches as an industrial standard. [2] Kraus & Naimer developed the world's smallest cam switch (model CA4N), [3] which is in the market since 1994.

Precision Mechanisms Corp. (PMC) was started by Leon N. Canick & Charles S Aldrich, the original company President & Vice President respectively, both Chief Engineers in 1957. Mr. Canick was a graduate of Columbia University, a mechanical engineer by trade. Mr. Aldrich was a graduate of Cooper Union University and also a mechanical engineer by trade. Both were former employees of Bell Labs, and also Servo Mechanisms Corp. where they both held senior mechanical engineering positions. Mr. Aldrich (Charlie to most) was credited with the design of the PMC Cam Switch and was the creative and innovative individual behind the scenes, whereas Leon was responsible for the business side of the company. The primary application include throttle control modules, flap/slat position controls, landing gear controls, bay door control and position indication, and in other similar functions where a rotary control and/or position monitoring are required. The uniqueness of our products is in the air design for weight and size and the ease of adjustment of the cam mechanisms. The patented cam mechanisms on each individual stack allow to accurately set desired angles even under conditions of corresponding shad linkage variations, especially when working with detentes. For switching purposes, we use exclusively Honeywell micro-switches only. Low loads are handled with application of golf contacts. Reliability is a high reaching millions of cycles for mechanical life and hundreds of thousands for electrical life. We design and manufacture our own gear boxes in combination with our cam switches and procured synchros and/or potentiometeres. We make cable assemblies and are qualified in Mil-Std-2000 soldering and harness manufacturing procedures. Our statistical process control system had been approved and certified by Lockheed Martin. A Low Torque, Precision Component with Adjustable Snap-Action Switching

• Adjusts to any desired switch dwell angle from 3° to 357 ° of shaft rotation. • Switch settings infinitely adjustable with respect to shaft. • Switch setting independent of other switches in stack • Switching angles cane be set and locked in seconds • Adjustments can be made while shaft is either stationary or rotating • Only 1-1/16" diameter; equivalent of BuOrd Size 11. The PMC Model CS 402 Cam Switch combines in a compact 1-1/16" diameter unit all the functions of a conventional plate cam, cam follower and snap-action switch. External screwdriver adjustments permit rapid setting of any desired switch make angle. Designed for timing, indication, control, computation and other applications where snap action switching is required, it permits the instrument and servo designer to meet specific application requirements through use of a single component that can be mounted in a gear assembly in a manner similar to synchros, potentiometers and other rotating shaft components. Because the CS 402 Cam Switch replaces conventional cam mechanisms, independently mounted switches and their associated hardware, it provides significant savings in design, fabrication and assembly time. Its small size permits significant improvements in miniaturization of the end product. Adjustment of the CS 402 Cam Switch can be accomplished rapidly and precisely while the shaft is either stationary or rotating, by means of two external adjusting screws, and can be completed within seconds. As a result, it provides a unique means for ‘trimming-in’ required performance in production or during equipment maintenance. Conveniently located locking screws maintain switch settings under all conditions of shock and vibration encountered by military equipment. Model CS 402 Cam Switches incorporate standard type SPDT, subminiature, snap switches and are available as single-switch units, or as multi-ganged types with as many as 10 switches. Both single and multi-stack types can be supplied with double-ended shaft for mounting dial or indicator. All types meet applicable requirements of MIL-E-5400.

Related Research Articles

<span class="mw-page-title-main">Analog computer</span> Computer that uses continuously varying data technology

An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude.

<span class="mw-page-title-main">Rotary dial</span> Component that allows dialing numbers

A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing. It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.

<span class="mw-page-title-main">Cam</span> Rotating or sliding component that transmits variable motion to a follower

A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion. It is often a part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an eccentric disc or other shape that produces a smooth reciprocating motion in the follower, which is a lever making contact with the cam. A cam timer is similar, and were widely used for electric machine control before the advent of inexpensive electronics, microcontrollers, integrated circuits, programmable logic controllers and digital control.

<span class="mw-page-title-main">Fishing reel</span> Hand-cranked reel used in angling to stow fishing line

A fishing reel is a hand-cranked reel used in angling to wind and stow fishing line, typically mounted onto a fishing rod, but may also be used to retrieve a tethered arrow when bowfishing.

<span class="mw-page-title-main">Camshaft</span> Mechanical component that converts rotational motion to reciprocal motion

A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines, mechanically controlled ignition systems and early electric motor speed controllers.

<span class="mw-page-title-main">Miniature snap-action switch</span> Electric switch that is actuated by very little physical force

A miniature snap-action switch, also trademarked and frequently known as a micro switch or microswitch, is an electric switch that is actuated by very little physical force, through the use of a tipping-point mechanism, sometimes called an "over-center" mechanism.

<span class="mw-page-title-main">Contact breaker</span>

A contact breaker is a type of electrical switch, found in the ignition systems of spark-ignition internal combustion engines. The switch is automatically operated by a cam driven by the engine. The timing of operation of the switch is set so that a spark is produced at the right time to ignite the compressed air/fuel mixture in the cylinder of the engine. A mechanism may be provided to slightly adjust timing to allow for varying load on the engine. Since these contacts operate frequently, they are subject to wear, causing erratic ignition of the engine. More recent engines use electronic means to trigger the spark, which eliminated contact wear and allows computer control of ignition timing.

<span class="mw-page-title-main">Cam timer</span> Electromechanical system for controlling events

A cam timer or drum sequencer is an electromechanical system for controlling a sequence of events automatically. It resembles a music box with movable pins, controlling electrical switches instead of musical notes.

<span class="mw-page-title-main">Timer</span> Type of clock

A timer is a specialized type of clock used for measuring specific time intervals.

<span class="mw-page-title-main">Rotary encoder</span> Electromechanical device

A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to analog or digital output signals.

<span class="mw-page-title-main">DC motor</span> Motor which works on direct current

A DC motor is an electrical motor that uses direct current (DC) to produce mechanical force. The most common types rely on magnetic forces produced by currents in the coils. Nearly all types of DC motors have some internal mechanism, either electromechanical or electronic, to periodically change the direction of current in part of the motor.

<span class="mw-page-title-main">Linear actuator</span> Actuator that creates motion in a straight line

A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor.

<span class="mw-page-title-main">Ball screw</span> Low-friction linear actuator

A ball screw is a mechanical linear actuator that translates rotational motion to linear motion with little friction. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. They are made to close tolerances and are therefore suitable for use in situations in which high precision is necessary. The ball assembly acts as the nut while the threaded shaft is the screw.

<span class="mw-page-title-main">Swashplate</span> Mechanism to convert between reciprocating and rotary motion

A swashplate, also known as slant disk, is a mechanical engineering device used to translate the motion of a rotating shaft into reciprocating motion, or vice versa. The working principle is similar to crankshaft, Scotch yoke, or wobble/nutator/Z-crank drives, in engine designs. It was originally invented to replace a crankshaft, and is one of the most popular concepts used in crankless engines. It was invented by Anthony Michell in 1917.

<span class="mw-page-title-main">Rangekeeper</span>

Rangekeepers were electromechanical fire control computers used primarily during the early part of the 20th century. They were sophisticated analog computers whose development reached its zenith following World War II, specifically the Computer Mk 47 in the Mk 68 Gun Fire Control system. During World War II, rangekeepers directed gunfire on land, sea, and in the air. While rangekeepers were widely deployed, the most sophisticated rangekeepers were mounted on warships to direct the fire of long-range guns.

<span class="mw-page-title-main">Fan (machine)</span> Machine used to produce air flow

A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.

Industrial fans and blowers are machines whose primary function is to provide and accommodate a large flow of air or gas to various parts of a building or other structures. This is achieved by rotating a number of blades, connected to a hub and shaft, and driven by a motor or turbine. The flow rates of these mechanical fans range from approximately 200 cubic feet (5.7 m3) to 2,000,000 cubic feet (57,000 m3) per minute. A blower is another name for a fan that operates where the resistance to the flow is primarily on the downstream side of the fan.

<span class="mw-page-title-main">Mouse mill motor</span> Simple electric-to-mechanical energy converter

Froment's "mouse mill" motor was an early form of electric motor, also known as the Revolving Armature Engine. It has similarities to both the synchronous motor and the contemporary stepper motor.

Variable valve lift (VVL) is an automotive piston engine technology which varies the height a valve opens in order to improve performance, fuel economy or emissions. There are two main types of VVL: discrete, which employs fixed valve lift amounts, and continuous, which is able to vary the amount of lift. Continuous valve lift systems typically allow for the elimination of the throttle valve.

<span class="mw-page-title-main">Kraus & Naimer</span>

Kraus & Naimer is an electrical switchgear manufacturer specializing in load and disconnect switches. Kraus & Naimer is world market leader in modular cam switches. and a supplier of switchgear for industrial customers in the fields of transport, conveyor systems, lift systems, mechanical engineering and power generation and power distribution systems.

References

  1. Kaspers, Walter: Messen Steuern Regeln für Maschinenbauer Archived 2018-02-13 at the Wayback Machine , p. 178, last accessed on 23 November 2016
  2. Ose, Karl 100 Jahre schalten, steuern, schützen: ein Beitrag zur Geschichte der Niederspannungs-Schaltgeräte in Deutschland. Verlag Brimberg, 1982
  3. "Company History". Archived from the original on 29 November 2016. Retrieved 30 November 2016. Company History, last accessed on 23 November 2016