Stugods excavator revolution

Hydraulic shear

recycling metals
recycling metals | Source

The excavator revolution

Excavators really have come a long way in my short life. Modern excavators are fast,smooth,reliable and so productive that their older cousins seem positively archaic. In my youth my father was a plant manager and transport manager for an Irish civil engineering company. Diggers as they were called did one thing and that was to dig holes.

Modern excavators dig and crush and break and even handle materials. How did that come about ?

The base point of all these different applications come from one thing the Servo system of moving oil.

Older excavators worked on the principle of moving a spool into the flow of oil and diverting that oil to do a different operation.

Although that was a very simple operation it had one drawback the oil is under extreme pressure approx 3,500 pounds per square inch.(psi)

The link from the spool to the lever would normally be a physical connection like a linkage, This would usually end up with a long lever to give the driver the required leverage to move the spool and divert the oil into a different operation.

The servo system uses lower pressure oil to do the work for the operator, The brake pedal on a car can be compared to the servo system, The small pressure exerted on the brake pedal is converted into serious stopping power via the brake wheel cylinders. This example is static though. Imagine instead of a brake pedal the oil is being pumped continually and it's flow can be diverted by a small amount via a manipulator lever. This low pressure oil then diverted to our spool instead of a large clunky lever.

So this small innovation of using a lower pressure oil to move the larger spool which then moves the high pressure oil to do the required action.

Well excavator hydraulic systems are a lot more complicated than that, But this was the single biggest change in excavator hydraulics.

Now our machine is so much faster and smoother to manipulate.

Mechanical shear

Me made a lot of these
Me made a lot of these | Source


The current crop of nearly all excavators manufactured today are controlled by two joy stick type controls and usually a couple of foot pedals for operating the tracks.

The advent of the manipulator control came hand in hand with the use of servo controlled hydraulics. And extreme precision can be achieved by the use of these joy sticks. I recently watched a Youtube video of an operator undressing a mannequin of items of clothing placed on it.

With this precision came the advent of a vast array of attachments which can quickly be changed by the flick of a switch in some cases.

This is my particular area of interest and some of the images on here are equipment we manufacture. The Bulldog shear is really just a big pair of scissors for cutting scrap metal.

The need for workers to cut metals up manually with oxy propane equipment is long gone.

The work was traditionally dangerous,dirty and the fumes given off were almost always dangerous in some form or another. Lead paint was very commonly used in the industrial revolution and is still very common in the US and Uk.

The lead will disappear from the blood stream fairly quickly but settles into the Human skeleton. Testing for lead contamination had to done regularly as it is undetectable soon after.

Undressing chicks with diggers

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