Product Description

1. Spring boxare used for the Rolling Shutter Door, like Garage Door .

2. Made of general Q235 steel plate give to quality and durability.

3. Surface alvanized in silvery , which make the wheels perfectly resistant to fight against rust.

4. The existing exterior diamaters come in 200mm, 220mm,240mm,260mm.

5. Interior diameter:  42mm 43mm 50mm .60mm 76mm

6. We also supply  hooks which used for the Spring Box

FAQ:

1. Are you a factory or trading company?
HangZhou Xihu (West Lake) Dis. Yongbida Hardware Factory is a professional manufacturer from ZheJiang province, we have high quality products of locks, spring box, door hardwares, other accessories, and so on.
 
2.Where is your factory?
Our factory is located in HangZhou, established in 1990s with 20000m2   and more than 60 employees in different departments , about 30minutes to the CBD of HangZhou and 1 hour to HangZhou Xihu (West Lake) Dis. international airport.
   
3.Can you produce the products as per customer design?
We started OEM and ODM business since 2007.  Please refer us samples or 3D drawing, we will offer the best prices for you.
   
4. How does your factory do regarding quality control?
We have staff to check every process, and each product will be inspected before packing by our QC staffs.
   
5. How about your packing?
Our products are packed with multi-packing to protect from the long-district transportation. EPE bag+ thick poly bag+ hardboard inner box +5-layer master carton.
Pallets are available if required, but the charge should be paid by you.
 
 6.How is your After-Sales service?
 Any defective products, Please send us the pictures of defective products to check. If the problem occurred by us, products can be returned, we will send you a replacement without extra fee.
 
7.May I get your sample for free to check before order?
Of course, free sample is available for checking, but you need to pay for the express cost, the delivery is about 2–4 days.
 
8.  How about your delivery day?
Usually our delivery time is about 30days after deposit.
 
9. How can I trust you in the first cooperation?
Firstly, samples can be sent to check our quality and you are welcome to visit our factory. 

10. If you have more questions,  just please contact us !

 

What is a pulley?

Pulleys are shafts or wheels on a shaft that support the movement and change of direction of a taut cable. The pulley also transfers power from the shaft to the cable. A simple pulley is used to raise the school flag. Read on to learn about the basic types of pulleys. We also covered the use of pulleys in everyday life. Read on to learn more about this important mechanical part.

composite pulley

A composite pulley is a mechanical system where 2 or more pulleys and ropes are connected together. It reduces the force required to lift the load because the force is divided by the distance of each pulley. Distance is equal to the mass of the object. Composite pulleys are a common mechanical system on sailboats. Composite pulleys can be used to lift heavy equipment such as sails.
The compound pulley unit consists of 2 pulleys, 1 fixed and the other movable. The fixed pulley is fixed overhead, while the movable pulley is connected to the load by a chain. The lift applies force to the other end of the rope. Anchor points are attached to fixed joists, ceiling joists or sturdy branches. The chain should be long enough to support the load during lifting.
Composite pulleys can be made from a variety of materials. Some are fixed and remain fixed. Others are detachable. The composite pulley combines the advantages of both types, making it a versatile tool. In the table below, these 3 types of pulleys are compared. It’s easy to see which 1 is best for your needs. The right choice depends on your specific needs and budget.
The compound pulley system consists of 2 fixed pulleys and 1 movable pulley. The compound pulley system multiplies the force by a factor of 2. The compound pulley system is particularly suitable for heavy loads and is ideal for construction sites. Workers apply less than half the load force on the composite pulley, significantly reducing the force required. This is a major benefit for many people.

Fixed pulley

Fixed pulleys are fixed gears of fixed length that are mounted on solid objects. There are many different types of pulley systems. Some cooperate with each other, but not “fixed”.
Fixed pulleys can be used for a variety of purposes. One application is to lift small objects. They have a one-to-1 mechanical advantage. Often, a single pulley can lift small loads. The force required to lift a single fixed pulley remains the same. They are usually used to lift lighter objects. They can even be attached to buckets used to draw water from wells.
While single fixed pulleys have desirable mechanical advantages, they are not suitable for force multipliers. Because their mechanical advantage diminishes over time, they are not effective force multipliers. They are used to redirect work so that it can be applied in the most convenient direction. This mechanical advantage is the main advantage of fixed pulleys and the most common way of moving objects. They have several benefits, including the ability to increase the speed of moving objects.
Another application for fixed pulleys is lifting supplies. A scaffold can weigh more than 1 and can be directly hoisted. In order to facilitate the transportation of materials, fixed pulleys are usually installed on the top of the scaffolding on construction sites. Then thread the rope through the edge of the groove that holds the pulley. The fixed pulley exerts the same force on the pull side as on the push side. The same is true for moving objects with fixed pulleys.

moving pulley

A movable pulley is a device whose part is fixed to another object, usually a rod or beam. The movable part moves with the load, making the load feel lighter. This is a useful tool for those who need to carry heavy items such as large bags. The advantages of moving pulleys are many. Here are some of them. Read on to learn more about them.
One of the most common uses of movable pulley systems is climbing high objects. Climbers act as pulley loads and pull ropes to lift objects. Eventually, when the traction stops, the climber descends. However, it is still a useful tool in other situations. The movable pulley system can help you climb the tallest objects or lift them to level surfaces.
Another example of movable pulleys is in industry. Depending on the load, movable pulleys make handling and moving loads easier. You can use them in a variety of applications in manufacturing and industry, including cleaning. For example, the American flag is raised and lowered every day. Removable pulleys are a handy tool when buildings need cleaning.
If you’re not sure whether a task requires a pulley, a zipline might be a good option. Connect the 2 ends of the rope and the pulley will move along the rope, then attach the rope to the metal cable. The load is the person holding the pulley, and the force comes from the attachment on the other end of the rope. There are 2 types of live pulleys: simple pulleys with just 1 wheel and live pulleys with many ropes attached.

School flag raised with simple pulleys

How is the school flag raised? It is pulled up by a rope attached to a pulley at the top of the pole. When the rope is pulled, the pulley turns, raising the flag. A pulley is a simple mechanism that helps people move heavier objects with ease. The rope must be securely attached to the pulley to keep the flag stable.
A simple pulley is a spinning wheel with grooves on 1 side and ropes on the other. The rope can be any length and the wheels can be any size. The rope has to go through the groove and the load is attached to the other end of the rope. Simple pulleys are pulleys with fixed shafts. An example is the wheel on a school flagpole.
A simple pulley system consists of a primary pole, a secondary pole and an outer member. The primary flagpole is connected to the track by a detour, while the secondary flagpole is connected to the track by a pipe. There is a groove on 1 side of the track, which passes through the inner cavity of the flagpole. An open track at the upper end of the track connects the 2 parts of the pulley.
A simple pulley can be used for many purposes. This is a useful machine that can be used to raise the flag. Among other things, it can be used in clothing lines, bird feeders, and even roofers. And, of course, you can use the pulley to raise the flag. Its versatility makes it an essential part of school decor.

cast iron pulley

If you are looking for pulleys for your machine, you may come across cast iron pulleys. They are usually cheap and available in a variety of sizes. The rim is held in place by a mesh attached to a central boss. The arms and spokes can be straight or curved, but most are oval. There are many uses for this type of pulley.
You might wonder why the arms of cast iron pulleys are so curved. Bent arms tend to yield rather than break. Cast iron pulleys are usually round with a slight bump on the rim, which helps keep the belt centered on the rim as it moves. On a 300mm diameter pulley, the bumps may be as small as 9mm.