Cord reels are used to manage and store extension cords that provide power to electrical equipment or devices situated at a distance from power outlets. They help in keeping long extension cords organized and prevent tangling or damage when not in use.

Flat PlugExtension CordHome Depot

Retractable cord reels are often installed centrally to streamline the workspace. They can be mounted on ceilings, walls, or workbenches. Commonly found in service garages, machine shops, and manufacturing facilities, these reels help keep the work area organized and efficient.

Medical cord reels are specifically engineered for use in healthcare environments such as hospital wards, operating theaters, emergency departments, medical labs, and radiology suites. They are also utilized in mobile clinics and portable laboratories.

Motor-driven cord reels can be powered by electric, hydraulic, or pneumatic motors. Electric motors, which use either AC or DC power from an electrical outlet, are straightforward to use, cost-effective, and efficient. Hydraulic and pneumatic motors, powered by pressurized liquids and compressed air, respectively, are ideal for environments lacking direct power sources. They are designed to avoid overheating under load and are suitable for areas with high fire and explosion risks.

A lubricant is a substance that is applied on surfaces that have relative motion in between them. The lubricant reduces friction and wears between the surfaces. However, the lubricant can have other...

The above diagram shows the behavior of two incident rays traveling through the focal point on the way to the lens. Note that the two rays refract parallel to the principal axis. A second generalization for the refraction of light by a double convex lens can be added to the first generalization.

Cord reel enclosures are often rated according to standardized systems. The manufacturer usually provides the specific rating for the enclosure, which indicates its level of protection.

Live connection cord reels enable continuous electrical flow through the cord even when part of it is still wound on the reel. These reels are equipped with connection hardware that includes electrical sockets. A crucial element for these reels is the collector ring, which ensures smooth operation while the cord remains live. The collector ring is responsible for delivering power and electrical signals necessary for the reel drum's rotation.

Ultra Thin FlatExtension Cord

First lets consider a double convex lens. Suppose that several rays of light approach the lens; and suppose that these rays of light are traveling parallel to the principal axis. Upon reaching the front face of the lens, each ray of light will refract towards the normal to the surface. At this boundary, the light ray is passing from air into a more dense medium (usually plastic or glass). Since the light ray is passing from a medium in which it travels fast (less optically dense) into a medium in which it travels relatively slow (more optically dense), it will bend towards the normal line. This is the FST principle of refraction. This is shown for two incident rays on the diagram below. Once the light ray refracts across the boundary and enters the lens, it travels in a straight line until it reaches the back face of the lens. At this boundary, each ray of light will refract away from the normal to the surface. Since the light ray is passing from a medium in which it travels slow (more optically dense) to a medium in which it travels fast (less optically dense), it will bend away from the normal line; this is the SFA principle of refraction.

Any incident ray traveling parallel to the principal axis of a diverging lens will refract through the lens and travel in line with the focal point (i.e., in a direction such that its extension will pass through the focal point).

Cord storage reels are designed to neatly wind and store extension cords. They typically include a reel drum and a frame with various mounting accessories, while the extension cord itself is purchased separately. Most of these reels are operated manually using a hand crank. They are ideal for keeping extension cords safe and well-maintained when not in use. However, they are meant solely for storage purposes and should not be used while the cord is energized. Always ensure the cord is fully unwound from the reel before plugging it in.

We have already learned that a lens is a carefully ground or molded piece of transparent material that refracts light rays in such a way as to form an image. Lenses serve to refract light at each boundary. As a ray of light enters a lens, it is refracted; and as the same ray of light exits the lens, it is refracted again. The net effect of the refraction of light at these two boundaries is that the light ray has changed directions. Because of the special geometric shape of a lens, the light rays are refracted such that they form images. Before we approach the topic of image formation, we will investigate the refractive ability of converging and diverging lenses.

The above diagram shows the behavior of two incident rays approaching parallel to the principal axis of the double concave lens. Just like the double convex lens above, light bends towards the normal when entering and away from the normal when exiting the lens. Yet, because of the different shape of the double concave lens, these incident rays are not converged to a point upon refraction through the lens. Rather, these incident rays diverge upon refracting through the lens. For this reason, a double concave lens can never produce a real image. Double concave lenses produce images that are virtual. This will be discussed in more detail in the next part of Lesson 5. If the refracted rays are extended backwards behind the lens, an important observation is made. The extension of the refracted rays will intersect at a point. This point is known as the focal point. Notice that a diverging lens such as this double concave lens does not really focus the incident light rays that are parallel to the principal axis; rather, it diverges these light rays. For this reason, a diverging lens is said to have a negative focal length.

As the cord is extended, it moves through a gap between two roller guides that steer its direction. These rollers are made from smooth materials to minimize cord wear. A ratcheting system locks the reel drum at various positions to maintain the desired length of the cord. A stopper, larger than the clearance, is positioned near the cord's end to secure it when fully retracted. Additionally, the guide arm adjusts the angle at which the cord is paid out.

The first consideration when choosing a cord reel is the type and specifications of the cord it will accommodate. It's essential to determine the cord's outer diameter, length, bend radius, and gauge before selecting a reel. These dimensions impact the size of the reel required; larger and thicker cords necessitate a bigger reel. Additionally, the weight of the cord should be factored in, as heavier and longer cords may need an automatic retraction system to handle the increased effort and save time and labor.

The above diagram shows the behavior of two incident rays approaching parallel to the principal axis. Note that the two rays converge at a point; this point is known as the focal point of the lens. The first generalization that can be made for the refraction of light by a double convex lens is as follows:

These cord reels help prevent tripping hazards and ensure a stable power supply to medical equipment, which is crucial for patient safety. They usually feature a spring-driven retraction system and are housed in a robust, durable casing. The materials used in medical cord reels are selected for their ease of cleaning, waterproof properties, resistance to corrosion, and antimicrobial characteristics.

In a retrieve configuration, the cord reel is attached to mobile equipment, with the cord’s free end secured to a stationary point. As the reel moves away from the anchor, the cord unwinds and extends. When the reel moves back towards the anchor, the cord retracts. Strong spring tension is necessary to ensure the cord retracts quickly enough to keep pace with the moving equipment.

IP Rating System. IP (Ingress Protection) ratings are used to classify electrical enclosures based on their sealing effectiveness against unwanted intrusion of foreign bodies and moisture. They indicate the suitability of the device for use in a specific environment. IP ratings are assigned per EN 60529 or IEC 60509.

Rotating PlugExtension Cord

These two "rules" will greatly simplify the task of determining the image location for objects placed in front of converging lenses. This topic will be discussed in the next part of Lesson 5. For now, internalize the meaning of the rules and be prepared to use them. As the rules are applied in the construction of ray diagrams, do not forget the fact that Snells' Law of refraction of light holds for each of these rays. It just so happens that geometrically, when Snell's Law is applied for rays that strike the lens in the manner described above, they will refract in close approximation with these two rules. The tendency of incident light rays to follow these rules is increased for lenses that are thin. For such thin lenses, the path of the light through the lens itself contributes very little to the overall change in the direction of the light rays. We will use this so-called thin-lens approximation in this unit. Furthermore, to simplify the construction of ray diagrams, we will avoid refracting each light ray twice - upon entering and emerging from the lens. Instead, we will continue the incident ray to the vertical axis of the lens and refract the light at that point. For thin lenses, this simplification will produce the same result as if we were refracting the light twice.

Motor-driven cord reels feature a motor to assist in winding the cord onto the reel drum. They are particularly useful when significant retraction force is required. These reels operate at slow speeds and maintain consistent tension on the cord, helping to prevent overstretching and potential damage.

Cord reels are commonly constructed from materials such as plastic (e.g., PVC, ABS), fiberglass, stainless steel, and aluminum. Metal cord reels are typically used for thicker, heavier cords and often feature anti-corrosion coatings to endure outdoor and harsh conditions. Plastic cord reels, suited for lighter cords, are generally used indoors. Premium cord reels may be designed to be water-resistant, non-sparking, dust-proof, and resistant to shock and vibration, making them suitable for extreme environmental conditions.

In a stretch configuration, the cord extends horizontally with some sag and no support. The reel can be either stationary or mobile and is typically mounted on the ceiling or high up on a wall. The cord should be 10% longer than the distance from the reel to the workstation to account for the sag.

Any incident ray traveling parallel to the principal axis of a converging lens will refract through the lens and travel through the focal point on the opposite side of the lens.

The required cord length must be estimated in order to select the live connection cord reel, which covers the distance between the power source and the workstation. The following are the operating parameters of cord reels pertaining to the required cord length:

The above diagram shows the behavior of two incident rays traveling towards the focal point on the way to the lens. Note that the two rays refract parallel to the principal axis. A second generalization for the refraction of light by a double concave lens can be added to the first generalization.

Explosion-proof or hazardous location cord reels are engineered to prevent sparks that could cause fires or explosions. They feature a spark-resistant ratchet mechanism and an explosion-proof slip ring enclosure. These reels are certified for use in environments where flammable and explosive materials are present, such as in mining operations, grain storage facilities, and manufacturing plants that produce fuels, fertilizers, paints, or explosives.

The certification and inspection of cord reels are conducted in accordance with UL 355, also known as the UL Standard for Safety Cord Reels. A UL certification indicates that a cord reel meets stringent safety and performance standards. Cord reels that have been certified by UL often display a UL mark to signify their compliance with these rigorous criteria.

A metering pump is a precision mechanical device that moves or pumps a measured amount of a fluid or liquid in a predetermined time period to create an accurate and exact volumetric flow...

In a vertical pick-up configuration, the cord reel is mounted on a machine component that moves up and down. The power source is located above the reel drum at the end of the cord. As the machine moves, the reel coils or releases the cord accordingly. Adequate spring tension is required to manage the cord’s upward movement into the reel.

Now we have three incident rays whose refractive behavior is easily predicted. These three rays lead to our three rules of refraction for converging and diverging lenses. These three rules are summarized below.

These three rules of refraction for converging and diverging lenses will be applied through the remainder of this lesson. The rules merely describe the behavior of three specific incident rays. While there is a multitude of light rays being captured and refracted by a lens, only two rays are needed in order to determine the image location. So as we proceed with this lesson, pick your favorite two rules (usually, the ones that are easiest to remember) and apply them to the construction of ray diagrams and the determination of the image location and characteristics.

Lighted cord reels have an attached lamp at the free end of the power cord. The light source may be an incandescent, fluorescent, or LED lamp. The cord is pulled at the desired length, and the lamp is hung on a ceiling or wall above the area being observed. The light from the lamp may be directed flexibly for optimal lighting.

These reels are commonly employed in heavy-duty scenarios, including outdoor and remote locations like mines, tunnels, refineries, construction sites, and water treatment facilities.

flat plugextension cord3-prong

The typical installation configurations for cord reels vary based on their intended use. This factor is crucial when choosing the right cord reel for your needs.

In a lift configuration, a stationary cord reel is fixed to a wall or ceiling above the work area. The cord is lowered vertically either manually or using a mechanism. The reel is built to support the weight of the cord and the outlet box, so it must be constructed from robust materials. A ratchet mechanism ensures that the cord stays in place when extended. This setup is commonly used in manufacturing environments and retail stores.

Cable reels hold conductive cable or lifting cable and are used for storage, unwinding, and winding. Contacts on electric cable reels keep the power on while winding. Reels are machines that wrap long, continuous goods like cable...

Commercial cord reels are optimally designed for light-duty applications. They are used in environments where corrosion is unlikely to occur. They are usually made of non-metallic material or stainless steel and are portable. They are commonly found in classrooms, offices, retail stores, and others.

Now suppose that the rays of light are traveling towards the focal point on the way to the lens. Because of the negative focal length for double concave lenses, the light rays will head towards the focal point on the opposite side of the lens. These rays will actually reach the lens before they reach the focal point. These rays of light will refract when they enter the lens and refract when they leave the lens. As the light rays enter into the more dense lens material, they refract towards the normal; and as they exit into the less dense air, they refract away from the normal. These specific rays will exit the lens traveling parallel to the principal axis.

The above discussion focuses on the manner in which converging and diverging lenses refract incident rays that are traveling parallel to the principal axis or are traveling through (or towards) the focal point. But these are not the only two possible incident rays. There are a multitude of incident rays that strike the lens and refract in a variety of ways. Yet, there are three specific rays that behave in a very predictable manner. The third ray that we will investigate is the ray that passes through the precise center of the lens - through the point where the principal axis and the vertical axis intersect. This ray will refract as it enters and refract as it exits the lens, but the net effect of this dual refraction is that the path of the light ray is not changed. For a thin lens, the refracted ray is traveling in the same direction as the incident ray and is approximately in line with it. The behavior of this third incident ray is depicted in the diagram below.

The connection hardware should provide enough electrical outlets to support all your devices. Consider safety features such as sockets with grounding terminals for added protection. Some cord reels are equipped with automatic circuit breakers to safeguard against short circuits and current surges. Additionally, certain models offer USB ports for convenient charging of devices.

Underwriters Laboratories (UL) is an independent safety organization headquartered in Northbrook, Illinois. UL’s team of experts tests and assesses various electrical products, including cord reels, to identify potential hazards.

Flatextension cordfor under rug

Stainless steel cord reels are typically made from grade 304 stainless steel, known for its superior mechanical properties, including high strength and durability, as well as excellent resistance to corrosion. These reels are ideal for use in industries such as food processing, pharmaceuticals, and healthcare, where maintaining hygiene and preventing contamination are critical. Additionally, other sectors can also take advantage of the robust performance and longevity offered by stainless steel cord reels.

Cord reels feature a cylindrical drum designed to hold and manage extension cords. The drum is equipped with two large flanges or discs on either end to keep the cord securely wound. This drum is mounted on a frame that includes various accessories, such as brackets and bases, allowing it to be attached to floors, ceilings, posts, walls, carts, or equipment.

360° rotating flat plugextension cord

To use the cord reel, pull out the desired length of cord to make the necessary electrical connections; this extended position is known as the payout position. Connect the equipment plug to the receptacles on the cord reel or at the end of the cable. The excess cord remains coiled on the drum. When the cord is no longer needed, the winding mechanism will automatically retract and rewind the cord onto the drum, keeping it organized and ready for the next use.

Retractable cord reels automatically pull the cord back to the reel drum, making them easier to operate than manual cord reels. They use a spring mechanism to provide the retraction force. As the cord is uncoiled and pulled out for use, tension builds up on the steel torsion spring. Once the electrical power is no longer needed, the stored energy in the torsion spring is released, retracting the cord back to the reel.

Consider the operating environment of the cord reel when making your selection. A robust enclosure or casing is essential for protecting the internal components from damage caused by moisture, corrosion, dust, and debris. Enclosures help ensure the cord reel’s performance and reliability, especially in outdoor or harsh conditions. Consequently, enclosed cord reels are generally preferable to open models.

Manual cord reels are operated using a hand crank that rotates the reel drum to extend the electrical cord. To rewind the cord onto the reel, you turn the crank in the reverse direction. These reels are suited for lightweight or shorter cables, as the manual process of winding and unwinding is relatively easy. They are portable, cost-effective, and commonly used in indoor settings like homes, offices, and retail spaces.

Flat plugextension cord10 ft

Cord reels are widely used across various industries to extend the lifespan of power and extension cords. They help prevent tangling and nesting, protecting the cords from wear, abrasion, and damage by allowing only the required length to be exposed for electrical connections. Additionally, cord reels enhance safety by reducing tripping hazards associated with cluttered cables. By choosing the appropriate type, specifications, and installation method for a given application, cord reels provide both convenience and practicality, making them a valuable investment for efficient and safe cord management.

Open cord reels are designed without an enclosure, providing direct access to their internal parts. They are typically used in light-duty applications and are suited for environments where corrosion is not a concern.

Low profileExtension Cord

A two-digit code is assigned to each electrical enclosure. The first digit indicates the protection from foreign bodies and particulates. Meanwhile, the second digit indicates the protection from moisture and immersion in water. The digit is replaced by “X” if the enclosure is unrated or offers no protection.

Lastly, consider your budget when selecting a cord reel. Opt for a reel that offers the necessary features and specifications while staying within your financial limits.

A hose reel is a mechanism for storing and use of a hose on a barrel for easy access. It is a system designed to make hoses, cords, flexible tubing, and wire conveniently available for immediate use...

Lighted cord reels are perfect for outdoor environments and locations lacking nearby power sources. They are also useful indoors, such as in service garages, where they provide additional lighting to illuminate the workspace.

When purchasing live connection cord reels, ensure that the reel comes with a cord of adequate length and the necessary connection hardware. It’s crucial to verify that the reel matches the required amperage, voltage rating, and plug and socket type to ensure reliable power transmission from the mains to your equipment.

Lubrication systems distribute the lubricant to the moving machine parts in contact. Lubricants reduce the friction between sliding or rolling machine elements, such as gears, spindles, bearings, chains, dies, screws, cylinders, valves, and...

Now suppose that the rays of light are traveling through the focal point on the way to the lens. These rays of light will refract when they enter the lens and refract when they leave the lens. As the light rays enter into the more dense lens material, they refract towards the normal; and as they exit into the less dense air, they refract away from the normal. These specific rays will exit the lens traveling parallel to the principal axis.

Now let's investigate the refraction of light by double concave lens. Suppose that several rays of light approach the lens; and suppose that these rays of light are traveling parallel to the principal axis. Upon reaching the front face of the lens, each ray of light will refract towards the normal to the surface. At this boundary, the light ray is passing from air into a more dense medium (usually plastic or glass). Since the light ray is passing from a medium in which it travels relatively fast (less optically dense) into a medium in which it travels relatively slow (more optically dense), it will bend towards the normal line. This is the FST principle of refraction. This is shown for two incident rays on the diagram below. Once the light ray refracts across the boundary and enters the lens, it travels in a straight line until it reaches the back face of the lens. At this boundary, each ray of light will refract away from the normal to the surface. Since the light ray is passing from a medium in which it travels relatively slow (more optically dense) to a medium in which it travels fast (less optically dense), it will bend away from the normal line. This is the SFA principle of refraction. These principles of refraction are identical to what was observed for the double convex lens above.

Choosing the right cord reel can significantly boost productivity and enhance safety in your workspace. With a variety of designs available, it's important to consider the following factors to select the most suitable cord reel for your specific needs:

In a drag configuration, the cord reel is mounted on a wall or post slightly above the floor. The cord is pulled horizontally from the reel, either manually or by machinery, as it remains on the ground. A ratchet mechanism secures the cord once it is extended. This configuration allows for flexible extension over longer distances as the cord moves horizontally.