3.1 STUDY REVIEW
Crane use and evolution started with the needs in the erection of anvil and structural works. Travelling cranes of the hand operated type were in use in the 1880s. About this time complicated designs of powered motion were offered by English and American builders involving a driving shaft along the runway and multiple clutches for transferring the power of the driving shaft to the hoist, trolley or bridge motions. Successive crane development ran thus: 1880 saw the hand powered crane, 1900 the electrical driven crane with a motor for each motion; by 1920 definite standards had been established for cranes in general and for various types of services; 1940 brought the enclosed gear cases, roller bearings and standardized designs; and 1960 produced the changes in crane control which resulted in smoother operation, safer handling of load,remote operation and new safety features for protection of equipment and personnel (Greiner,1967).
Crane use and evolution started with the needs in the erection of anvil and structural works. Travelling cranes of the hand operated type were in use in the 1880s. About this time complicated designs of powered motion were offered by English and American builders involving a driving shaft along the runway and multiple clutches for transferring the power of the driving shaft to the hoist, trolley or bridge motions. Successive crane development ran thus: 1880 saw the hand powered crane, 1900 the electrical driven crane with a motor for each motion; by 1920 definite standards had been established for cranes in general and for various types of services; 1940 brought the enclosed gear cases, roller bearings and standardized designs; and 1960 produced the changes in crane control which resulted in smoother operation, safer handling of load,remote operation and new safety features for protection of equipment and personnel (Greiner,1967).
From
the cranes used in building and structural engineering works, cranes have been
developed for all cadre of material handling jobs in manufacturing and service
industries. As a result,many different varieties of crane exist. Broughton
(1958) grouped all cranes into fourmain categories, which remain applicable
today,
as
enunciated by Thompson Geoffrey (2007):
Overhead
Travelling Crane: This consist of fixed rails lying on one or two elevated
girders with the trolley or crane bridge (with hoisting apparatus) that can
transverse the length of the rails.
The
Jib Crane: This consists of an inclined member that can rotate about a central
point and suspend the load from the outer end of the inclined member.
Gantry
Crane: This is a girder or girders connected to vertical members which are
either fixed or move along tracks at the base of the vertical member, the
hoisting equipment can be usually traverse the bridge girder or girders.
Cantilever
or Tower: This is a vertical mast with a horizontal cantilever that rotates
horizontally around the vertical member. The trolley and hoisting equipment
move along the horizontal cantilever. The hydraulic shop crane is a small
cantilever crane operated manually and can be moved in all directions through
the action of the steel
or rubber tires installed at the base.
According
to a document of control engineering practice, in the context of further
automation of manufacturing processes, automated transportation of heavy weight
using crane becomes more and more important. Applying the skills or Robots to
crane automation, a wide market of new applications could be developed (Sawodny
et al., 2002).
3.2 CONCEPT DESIGN
The construction of hydraulic engine hoists consists of such larger parts as the main frame, hydraulic jack, legs, wheels, boom and a chain with a hook at the end of the boom.
Ø Main Frame - The part that holds everything together is the main frame or upright post. The main frame, haves two support plates on the sides which adds to the durability and stability of the tool. Also, it has a handle with rubber grips mounted to the top part of the frame, which allows moving the hoist easier when it is carrying a load.
Ø Hydraulic Jack - Hydraulic jack is the most important and advanced part of a hydraulic hoist that uses a hydraulic system to lift heavy objects. It generally is a hydraulic bottle jack that has one side mounted to the main frame and other side to the boom. The engine hoists have special mounts on the side of the upright post, where you can insert the pumping bar, so it does not lie around your garage floor while not being used.
Ø Legs And Wheels - Hydraulic engine hoists are equipped with two legs and 4 big casters and two small casters. It has expandable legs that provide better stability for the machine. For example, the engine is located further into the engine compartment, so you need to lift it out with fully extended boom. Then you can also extend legs of the hoist and move them further below a car. It also has foldable legs which mean that they can be lifted upwards when the hoist is not in use so it takes much less space when stored. Legs can be quickly folded using a quick release pin system and unfolded in the same way, meaning that you can change the hoist from working to folding position and back usually in under a minute. Casters are used to transport the hoist and are made with durable steel bearings allowing moving the hoist also when carrying a load. Hydraulic engine hoists need a firm and level surface, so wheels can roll freely on the surface and does not get stuck into the ground when lifting a load.
Ø Boom, Chain and Hook - To lift a load an engine hoist has an adjustable boom. It means that the boom can be extended to reach engine blocks located further into the engine compartment. Boom can be extended pretty quickly using a simple pin system. At the end of the boom is a steel chain with a grab hook, where you can attach the load.
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