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Press brake bending is simple stuff: An arrow-shaped punch presses a sheet metal blank into a v-shaped die, thereby forming an angled bend. Or maybe, if we are getting adventurous, we could imagine something like a gooseneck punch making return flanges, but that is stretching it as far as it goes, right?
No, not quite. Press brake tooling has come a long way in recent years, and can do a lot more than it used to, and probably a lot more than you think. Some of the more interesting techniques include wiping, rocker dies, 3 way bending and elastomer bending.
A wiping operation consists of more than one movement, unlike simpler shaping methods. A special die set is used, where the bottom die has movable elements. As the punch moves down and executes the first part of the bend, the bottom element receives the blank and is pressed down on its springs. This motion activates an element on the back of the die, which now moves in and executes the second part of the bend. A good example of the application of this technique is the making of a radiused return flange: The blank is pushed down on the first, springloaded element, and the resulting downward motion bends the blank to a right angle with a radius at the bending point. The second element then comes into play and finishes the job by folding the edge of the blank over, creating a return flange in the process.
Rocker dies are essentially simple dies - with a twist: The top die has a built in 1-axis joint, which allows it to enter a bottom die with a partially obscured opening. This makes it possible to form a channel in one pass, even if the flange is very long - something that (depending on the shape of the part)might not be doable in a traditional channel die set. In that case, rocker dies provide the benefit of reduced setup time and fewer operations in order to shape the part.
The term 3 point bending is used about a special type of die set, in which the bottom die has an element which can be adjusted in height by a servo motor. The top die is buffered from the ram with a special hydraulic cushion to compensate for little variations in the thickness of the blank. Together, the two dies make it possible to attain extreme precision in the angles bent - down to 0.25 degrees. This type of tooling is expensive though.
Elastomer bending is especially interesting. Here, the bottom die isn't steel, but a flat piece of synthetic material which serves to wrap the blank around the punch, as it comes down. The resulting bend radius will be very close to the punch radius, as there is little springback. Also, the elastomer pad does not mar or scratch the blank.
These are some of the techniques that keep press brakes relevant in today's sheet metal fabrication work.
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The design of mechanical diggers has evolved since their creation in the late 19th century. As more tasks are carried out by heavy machinery and the manufacturing processes improved, the ability to tailor the attachments to specific jobs became more elaborate. The excavator bucket attaches to the end of the boom (the articulated arm protruding from the front or rear of a machine). Nowadays there are several commonly used excavator buckets which are used to perform particular tasks.
General Purpose
This design is intended to be useful for most excavation tasks. These buckets normally have teeth at the front which help to get purchase underneath the material that needs to be moved. This allows the bucket to cut through earth more easily than a flat fronted excavator bucket by dragging it toward the machine.
Ditch Maintenance
These excavator buckets are intended to move loose surfaces and carve gradients into landscapes. They normally have a straight front edge which makes them ideal for clearing away the surface rather than cutting through it. Due to the flat front it makes this kind of bucket unsuitable for heavy digging. They will also normally be fitted with drainage holes which reduce the weight and make them easier to work with in areas where water may have collected.
Ribbed Bucket
This type of excavator bucket is specifically designed to work with backhoe machinery which drags the bucket along the ground behind the vehicle. The outer of the bucket is fitted with wear strips which give it the ribbed effect for which it was named. These offer a surface which is designed to be worn from dragging. These plates can then be replaced which extends the working life of the bucket. As these buckets can be used on a multitude of surfaces they normally have teeth similar to the general purpose buckets.
Dedicated Bucket
These excavator buckets also have teeth, like the general purpose buckets and replaceable wear plates like the ribbed bucket.
Grading Bucket
This type of excavator bucket has a sharp edge with no teeth which make them ideal for carving gradients. The main difference between these and ditch maintenance buckets are the drainage holes which make up a larger area on the grading buckets which further reduces the weight.
Grain / Potato Shovel
This type of excavator bucket aims to reduce potential damage to crops during transit by having a rounded leading edge. They may also include wear strips from the toeplate to the back of the shovel which can be replaced to prolong the service life.
Rehandling Bucket
This type of excavator bucket is normally used for loading tasks. The leading edge may have a drilled toeplate which allows teeth to be fitted for tasks which require the bucket to cut through the material. Rolled backs make it easy to release the material.
Quick Hitch Mechanisms
Most excavator buckets can be used with quick hitch mechanisms which allow the operator to interchange attachments quickly. They are secured to the dipper arm with two pins which can either be released manually by the operator or remotely with a hydraulic ram. These mechanisms enable operators to change attachment more frequently but have also caused many accidents resulting in serious or fatal injuries. The majority of these accidents have been attributed to semi-automatic systems which require a pin to be removed manually before the operator released the bucket remotely.
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In the past decade the prices of oil and gas have reached an all-time high. This has led to the increase in the use of alternative fuels. One such alternative fuel that has gained popularity in recent times is 'firewood'. Firewood is cheap and cost effective, burning firewood is carbon neutral and it is easily available. It is because of these reasons that a lot of people have started using firewood in their homes, to provide heat, instead of gas or oil. To use firewood in an open fire or wood burner, the wood needs to be cut into a specific size. Cutting firewood can be a tedious and physically exhausting task. There is however a machine available that makes the task a lot easier. This machine is called a 'Log Splitter'. In this article we will find out what it is, what are its advantages, and which is the best one for you.
What is a log splitter? To put it simply, it is a mechanical axe. It is designed to split logs faster than a conventional axe. It makes the task of splitting logs a lot easier and safer. They work by using a motor powered hydraulic pump to exert pressure against the log with the help of a metal wedge, this forces the log to split open. They are very useful as they split logs into the exact size necessary for various wood burners around the house. They are easy to use and not overly complicated.
How can you choose the right log splitter? There are a number of makes and models available in the market. This can get very confusing for a prospective buyer. The important thing to keep in mind is that there are three types: Hydraulic, Electric and Gas Log Splitters. How fast and how powerful it can be depends on the splitting force (RAM) that it can exert on the log. For domestic use one with a RAM between 10 to 15 tons is sufficient, but for professional use on a larger scale one capable of exerting between 25-40 tons of pressure will be required.
To make sure you choose the right log splitter, make a list of your requirements and then match it to the benefits of the machine. If you require one for home use that requires little or no manual labor; then you should get an electric or gas powered one that has a RAM of 10-15 tons. If you would like to move it to your area of work and store it in a different area then you should get one that has large transport wheels. This will make it more convenient to use.
Log splitters are extremely useful and can help save a lot of time and energy. When choosing one make sure you keep in mind all your requirements and then buy the machine that is best capable of fulfilling them.
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Anybody who has ridden a bike with spring coil shock absorbers on hard undulating surfaces would know how different and efficient the damping is on a pneumatic and hydraulic shock. The present day shock is a very state of the art shock and vibration damping equipment that works on either compressed air power or fluids to dissipate the energy and the vibrations generated from tyre contact with road surface. The shock impulse is dissipated through the Pneumatic and hydraulic cylinders with a sliding piston setup inside. The cylinder is filled with a fluid or air, as the requirement might be. Shock absorbers find use not only in the motor and automobile suspensions but in aircraft landing gear, in drilling equipment, in earth moving equipment, in oil rigs and many other huge industrial machineries. The same principle behind shock absorbers is employed in rail transport which limits the yawing of bogies from side to side in a fast moving train.
Pneumatic and hydraulic damping systems contain pneumatic cylinders or hydraulic cylinders which employ a steel piston, a piston rod, a cylinder barrel setup to help deliver the damping effect. As compressed air or fluid moves into a pneumatic or hydraulic cylinders, it pushes the piston up or down through the length of the cylinder. The reflex action of the piston is either activated by either the compressed air or by a spring mechanism, which brings back the spring to its original position. These are also called Single Action Cylinders. Cylinders come in a variety of types and may either be pneumatic cylinders, electro pneumatic cylinder, hydraulic cylinders or electro hydraulic cylinders. Double Acting Cylinders (DAC) employ the force of air to move in two ways, in an extend stroke and a retract stroke. Double Acting Cylinders have two ports, one for outstroke and one for in-stroke.
As the industry requirements may vary, pneumatic and hydraulic cylinder come in a variety of bores and strokes configurations. These may vary between being smaller than an inch all the way up to several feet. The power of compressed air or air may range from a few pounds per square inch to hundreds of pounds creating enough power and force of a few thousands of pounds. The pistons rods are usually made of toughened alloy steel. Cylinder pipes are seamless drawn and are precisely honed to the smoothest finish to prevent corrosion and provide long life for piston-seals.
Valves present inside the pneumatic and cylinder help regulate the flow of compressed air or fluids and maintain the pressure inside the pressure inside the pneumatic or hydraulic cylinder. Some pneumatic cylinders reach 1000 mm in diameter, and are used in place of cylinders for special circumstances where leaking hydraulic oil could impose an extreme hazard. Pneumatic and hydraulic cylinders also find application in automated shutters in train and tram doors, and automated exits that are monitored and activated by sensors. The low friction nature of arrangement in Pneumatic and hydraulic cylinders enable a smooth, slow-speed operation and at a low pressure which is a safety consideration in human traffic areas.
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Some people are thinking that installing an elevator is luxury and some people, necessity. If you are one of those who think that means luxury, it's all right; I'm not saying that installing home elevators is a must. At least that you can do is to read this article and maybe you'll learn something new about the lifts. If you are one of those who think that means necessity I want to tell you some details about the most used types of elevators for home appliance.
The most used types of home elevators are: hydraulic elevators, electric (traction) elevator, pneumatic lift elevator and overhead winding drum. Hydraulic lifts are the most secure and the most used home elevators. These lifts are operated by hydraulic rams also known as a "hydro rams". They are pumps that cycle the water, supplied by hydro-power.
There are a few types of hydraulic elevators, known as "roped-hydraulic", "hole less", and "in ground". "In ground" systems must have a huge hole at the lowest level of the house and has to be drilled down, with depth same as the length of the lift trajectory. That's because the cylinder is moving down through the hole as the cab is moving up. Sometimes there are no possibilities to drill this hole. In that case are using "hole less" systems because on each side of the elevator they are using a pair of hydraulic jacks as a moving force. Roped-hydraulic system is alternative when it's not possible to drill hole for the cylinder and the cab travel is greater than the "hole less" systems can provide. They are combination of hydraulics and ropes connected to jacks, controlled by friction governor and governor-tension sheave.
Electric also known as traction elevators have two types of traction systems. The traction systems can be geared or gear less. The geared systems can be power supplied by alternative or direct current. Geared machines are using to control the moving of the cab. The cab is connected by big steel ropes and they are rolled by high-speed motor over drive sheave. The gear less system includes alternative or direct current high-speed gear less motor which is attached to the drive sheave directly without using steel ropes.
The third type is the pneumatic elevators. These lifts can carry only one or two people and their cab is moved by pneumatic system by creating air pressure difference between the top and the bottom of the cylinder tube. No cables, no pistons and no pulleys, just like the elevators in the "sci-fi" movies. The aluminum and glass are the only materials used in the process of manufacturing of these residential lifts.
The last of the four types is overhead winding drum elevator. As we can assume from their name these types of residential lifts, an overhead winding drum is used to manipulate with the elevation cab, so there's no need for machine room because the winding drum machine is placed at the top of the elevator hoist-way.
I hope that this information was quite helpful for you and as a potential buyer you've got some clarifications about the types and subtypes of home elevators. I'm sure that you'll make the right choice and you'll install the most suitable elevator, according to your requirements.
| Price : | Post Date : Nov 11, 2011 17:57:22The ram pump, or water ram, is a very useful 'old-tech' device that has been around for many years and is as useful today as ever. It can pump water from a flowing source of water to a point ABOVE that source with no power requirement other than the force of gravity. Invented before electric water pumps, this rugged, simple and reliable device works continuously with only 2 moving parts and very little maintenence. Typically installed at remote home sites for domestic water supply, watering livestock, gardens, decorative lily and fish ponds, water wheels and fountains. Because it uses no power, a ram pump can be used where water would normally not be used and would flow on downstream.
This book explains in simple terms and with illustrations how the ram pump works, where and how it can be set up, and how to keep it going. The second section of the book gives step-by-step plans for building a fully operational Atlas Ram Pump from readily available plumbing fittings and which require NO welding, drilling, tapping or special tools to fabricate. The final chapter shows how to build an inexpensive ferro-cement water storage tank.
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