Mechanical Engineering Dictionary-Material Handling System

Important Terms and their Meaning of Mechanical Engineering-Material Handling System:

ADJUSTABLE RAMP – A loading platform that is power operated or mechanically operated.

APRON CONVEYOR – A conveyor for transporting packages or bulk materials, consisting of a series of metal or wood slats (also rubber, cotton, felt wire etc.) attached to an endless chain. Also called SLAT CONVEYOR.

ARRESTING GEAR – Means of sustaining the load which do not interfere with the hoisting gear but prevent it from coming down due to gravity e.g., ratchet and pawl arrangements and friction type.

AUTOMATIC GRAB – A crane grab in which the grasping and releasing of the load are effected without manual assistance.

BAND or BELT CONVEYOR – An endless band passing over, and driven by horizontal pulleys, thus forming a moving track which is used to convey loose material or small articles.

BALANCED LUFFING – Luffing mechanism, in which the moment due to the weight of the jib is at balance with the moment produced by the counterweight.

BARGES AND LIGHTERS – Shallow draft, box like vessels used for cargo transport in protected waters such as bays, rivers and canals.

BARREL ELEVATOR – This comprises parallel travelling chains, with curved arms projecting. The chains pass over sprocket wheels at the top and bottom of the elevator, and lift barrels from a loading platform to a runway.

BARREL HOPPER – A machine for unscrambling, orientating and feeding small components during a manufacturing process, in which a revolving barrel tumbles the components onto a sloping, vibrating feeding blade.

BAY – An area used for the open storage of heavy items.

BELT CONVEYOR – A conveyor which consists of a belt of suitable material such as rubber, canvas, balata etc., running over a pair of end drums or pulleys and supported at intervals by a series of rollers called idlers, these in turn being supported on a conveyor frame.

BELT CONVEYOR IDLERS – Number of idler rolls provided between the terminal pulleys to prevent the belt from sagging due to gravity and under the load.

BELT CONVEYOR PULLEYS – Wheels used to support and drive the belt. They include drive, terminal or bend, take up and snub pulleys.

BIN – An enclosed space for storing certain types of goods.

BIN TICKET – Tickets attached to storage places to provide information on the quantity of goods received, issued and on hand.

BRACING – Securing the contents of a shipment to prevent shifting and damage.

BRAKE – Arrangement in the hoisting machinery to stop the load and hold it when applied to the hoisting motion or bring the relevant mechanisms at rest within specified braking distances. May be a band brake, disc brake or a cone brake.

BUCKET ELEVATOR – Conveyor equipped with buckets which carry bulk material in the vertical or near vertical direction, loading is at the bottom and discharging is at the top.

BULK COMMODITY TRUCK – Trucks used to transport loose bulk materials, such as sand and gravel.

BUCKET OR SKIP HOISTS – Hoisting equipment for handling of bulk materials in self dumping buckets or skips.

BULLDOZER – A pendant attachment mounted on crawler and wheel tractors, that strips off soil surface and transports it to the required spot.

CANTILEVER RACKS – Racks supported only on one end, leaving the other end open for placing and removing the long bars, rods etc.

CAPSTAN DRUM – Equipment used for hoisting anchors on board ships, hauling various loads etc.

CAR PULLERS – Equipment used for shunting railroad cars at ports and docks.

CAROUSEL – A rotating or circulating storage device. The worker stays in one place while the needed item comes to the work station.

CHAIN CONVEYORS – Conveyors which employ chains of various designs as the driving traction element. Chain conveyors carry aprons, pans, buckets, cradles, pockets, cars etc.

CHOCKS – Supports used to keep boxes off the ground.

CHUTE – An inclined surface with sides for material movement by gravity.

COLD STORAGE WAREHOUSE – A warehouse used for storing highly perishable goods and foods.

CONTAINERIZATION – Transportation of freight in sealed portable containers.

CONVEYOR – A mechanism that moves material along a fixed path. A mechanical device for carrying packages or bulk material from place to place (as by an endless moving belt or a chain of receptacles).

COUNTER WEIGHTS – Weights provided on cranes to offset the dead weight of metal structure and, to a certain extent, the moment due to the hook load.

COVERED HOPPER – A freight car with a closed top designed to meet the needs of malt and grain shippers.

CRANE – A machine for raising, shifting and lowering heavy weights by means of projecting swinging arm or with the hoisting apparatus supported on an overhead track.

CRANE DERRICK – The distance between the loads centre of gravity and the axis about which crane boom can swing.

CRANE HELICOPTER – A crane hung from a helicopter, used as a means of moving loads and doing a variety of jobs in regions which are difficult of access, capable of descending vertically on the load and lifting it from the ground directly.

CRAWLER CRANE – A crane mounted on a crawler mounting, e.g., a frame supported by track laying assemblies which obtain the drive from an engine mounted on a rotating part of the crane.

CREEPING DRIVE UNIT – An arrangement frequently employed on electric hoists to obtain extra low spotting speeds.

DEAD ZONE – In a shop floor, when two overhead bridge cranes serve adjacent bays, part of floor area (about 15 to 20%) inaccessible for any of the hooks, as close as they may be. This is dead zone.

DERRICK – A framework over a drill hole (e.g., on oil well) for supporting the boring mechanism for hoisting.

DIESEL ELECTRIC DRIVE – System consisting of a diesel generator set and electric motors on all motions.

DOUBLE BOTTOM RIG – Two trailers joined to a tractor.

DOUBLE FACED PALLET – A pallet with two decks that form the top and bottom surfaces.

DOUBLE STRING TIE – A method of tying heavy packages.

DOUBLE WALL CORRUGATED FIBREBOARD – Fibreboard consisting of three flat facings and two corrugated pieces arranged in alternate layers.

DOUBLE WRAP – Two or more sheets of paper used to wrap breakable articles.

DRIVEWAY INSTALLATION – A loading ramp that raises or lowers the truck so that the floor of the truck is level with the dock.

DRUM – In hoisting unit, a device for spooling the rope in one layer or in more than one layer.

DUNNAGE – Lumber or other material used to brace a shipment in transport.

ELECTRIC DRIVE – An arrangement consisting of an electric motor, suitable motor controls, and a gear train linking the motor with the operating mechanism.

ELEVATOR – A platform or caged hoist that moves material or personnel from one level to another.

ELEVATING GRADER – Machine that cuts soil layer by layer and moves it away by means of a conveyor into a dump or onto transporting facilities.

ESCALATOR – Chain conveyor specially adapted for the vertical transportation of people over an inclined path. It is an inclined conveyor with the driving traction in the form of steeps attached to step drive chains and each escalator step is carried on four wheels riding on tracks.

EXCELSIOR – Shredded or curled pieces of wood.

FISHYBACK – The transportation of highway trailer bodies abroad ship.

FLAMMABLE – A marking on the box to indicate that the contents may easily set on fire or have a tendency to explode.

FLAT BED TRAILER – A flat surfaced platform with wheels.

FLATTENED STRAND WIRE ROPE – A modification of linear contact ropes. During its manufacture, every strand laid from wires of circular cross–section is radially squeezed over the circumference so as to flatten the wires.

FLEX – Flow tank car. A pressurized tank car that can unload in a few minutes.

FLOATING CRANE – A crane mounted on self propelled or towed pontoons, used for salvage work, along shore and offshore duties, crane motions are accomplished with electric drives, commonly of the dc type employing the Ward Leonard control.

FLOW RACK – Rack in which the material can be inserted at one side and will move by gravity to the other where order picking takes place.

FORCE OF GRAVITY – Force decided by the attraction the earth exerts on a body which, unlike the mass, depends on the local value of the acceleration of free fall.

FORK LIFT TRUCK – Equipment designed to pick up, transport, stack and unstack pallet loads.

FOURWAY PALLET – A pallet design that permits entry of materials handling equipment from four sides.

FRAGILE – A marking on the box to indicate that the contents are delicate and breakable.

GANTRY CRANE – Crane consisting of a bridge crane superimposed on two frames or legs operating on a rail track flush with the ground.

GENERAL MERCHANDISE WAREHOUSE – The most common type of public warehouse for storing manufactured or non-manufactured goods that require protection.

GONDALA – A car with low sides and no top.

GRAB – Device suspended from the crane hook which grasp and release the load (of given shape and size) at almost no time.

GRAVITY ROLLER CONVEYOR – A material handling installation in which the bed consists of rolls fitted to a frame. Suitable for handling of unit loads and containerized high volume materials.

HAND DRIVE – Manual operation which is in wide use on the hoisting and slewing motions of slow running, low capacity machinery.

HOOK – Multipurpose attachment widely used in hoisting installations, carries the load by one or more of slings made of hemp ropes or chains.

HYDRAULIC POWER EQUIPMENT – Unit which consists of an electric motor or internal combustion engine driving a pump which feeds fluid into the hydraulic operating cylinder through the lines with control valves.

H WARP – A method of wrapping large fragile items.

HOISTING MACHINE – Moves loads vertically as well as transfers them from one point of the area covered by the machinery into another.

INDUSTRIAL TRUCK – A self powered, individually operated conveyance for moving materials or persons.

JACK – Device used to lift loads through a short height some 0.8 to 1 m used widely in repair and erection jobs, e.g., screw jacks, rack and lever jack’s rack and pinion jacks and hydraulic jacks.

LANG LAY ROPE – A rope in which the wires are twisted in the same direction as the strands are.

LEFT HAND LAY ROPES – Ropes in which the strands bend round to the left.

LEVEL LUFFING – Luffing mechanism which ensures that the crane hook travels along an almost horizontal path when luffing is in progress.

LIFT – Hoisting equipment adapted to lift loads vertically.

LIFTING CAPACITY – The maximum safe load the machine is designed to handle.

LIFTING MAGNET – Handling device, operating on direct current. Widely used in handling steel and cast iron loads.

LIFTING TACKLE – A system of stationary and movable sheaves interlinked by a pliable member in the form of a wire rope to obtain a gain in either force (power lifting tackle) or speed (speed lifting tackle).

LUFFING or DERRICKING – It is the pivoting of the crane jib in a vertical plane so as to change the reach.

MANIPULATOR – A device that grasps an item and moves it to a new position or orientation for the next operation. It may be a simple pincer or complicated robot.

MATERIALS HANDLING – Procedures involving receiving, storing, sorting, packing, shipping, freight handling and controlling of goods and materials.

MONORAILS – An overhead track (usually an I beam) upon which the carriers or hoists move.

MULTIPLE RACK CAR – Special equipment designed to carry motor cars.

NON-SPINNING ROPES – Multilayer constructions having alternately opposite lays of individual layers.

OPEN HOPPER – A freight car with an open top and collapsible bottom.

ORDINARY LAY ROPE – A rope in which the direction of twist of wires is opposite to that of the strands in the rope.

ORDINARY (untwisting) ROPES – Ropes in which the wires and strands fail to retain their position once the wire sizings are removed from the ends and consequently, these ropes tend to untwist.

ORIGINATING CARRIER – The first carrier to receive the goods from the shipper.

OVERHEAD BRIDGE CRANE – A shop floor unit consisting of a trolley or crab equipped with a hoisting mechanism, a bridge travelling on wheels fitted to end carriages and supported by track rails, which in their turn are fixed to rail supports provided either at the top of the shop walls or columns.

OVER LOAD PROTECTION DEVICE – Units provided on the hoisting motion that automatically cut out the hoisting motor on jib and tower cranes when the excess of load lifted is not less than 10 per cent of the rated capacity.

PALLET – A standard platform on which material is placed for storage and movement. The platform has an upper and lower flat surface with space between for the forks of an industrial lift truck.

PIGGYBACK (TOFC) – Transportation of highway trailers or demountable trailer bodies on specially equipped cars.

PIN WHEEL PLATFORM – A pallet pattern used for the arrangement of items of unequal length or width.

PIPE LINES – Specialized carriers that transport petroleum or natural gas.

PLATE CLAMP – Handling attachment which is an eccentric clamp used for handling steel sheets and plates in the vertical position.

PNEUMATIC CONVEYING – Method of transporting bulk materials in the form of powder, short fibre and granules over a pipe line as a mixture with air or due to the pressure of air, e.g., suction or vacuum type systems, pressure type systems, combination systems.

PNEUMATIC DRIVE – System in which compressed air is admitted into direct acting cylinders under pressure, the piston rods are linked with the business end.

PORTABLE PLATE – A loading ramp that can be moved to any loading position on the deck.

POSITIONER – A device that orients and positions the part for the next operation.

POWER DRIVE – Drive provided in the form of electric motor, steam engine, internal combustion engine, hydraulic or air motor. Includes combinations such as diesel electric, electro hydraulic, electro pneumatic drives.

POWER SHOVEL – An earth digging machine with an operating member (bucket) which digs soil, carries it over a small distance and dumps it in a pile or onto transporting facilities.

PREFORMED WIRE ROPES – The ropes in which the wires and strands, before being laid, are preformed to fit the shape they carry in the rope.

RACK – A storage place for individual items or palletized loads.

RAIL ROAD CRANE – Crane mounted on a truck meeting railroad requirements and supported by axles of varying number used for load handling and wreckage clearing purposes, carry a power unit which is a combination of a diesel, a generator and a number of electric motors.

REACH OF CRANE – Distance of the load from the axis of the rotary part of the crane, decided by crane stability, decreases with an increase in the load to be handled.

REVERSIBLE PALLET – A pallet with an identical top and bottom deck.

REVOLVING CRANE – A crane which can lift up the load and transfer it to any point of a circle with a radius equal to the reach, being thus suitable for loading the rail road flat cars and lorries, for construction site works etc. e.g., travelling revolving crane, fixed revolving crane.

RIGHT HAND LAY ROPES – Ropes in which the strands bend round to the right.

ROW PATTERN – A pallet pattern used for the arrangement of items of unequal length or width.

SCRAPER – Machine that removes earth slice by slice, transports and places it in an earth structure, or pushes it to a dump and then levels the same.

SCREW CONVEYORS – Installations serving to move materials over a trough by a rotating screw. Also called SPIRAL CONVEYORS.

SEAL – A small metal strip that is placed on a railroad car door when loading is completed.

SELF CLOSING GRAB – A crane grab which can pick up the load automatically but must be released with manual assistance.

SELF LEVELING – Bringing the lift to a stop so that its platform is level with the landing.

SEMI GANTRY CRANES – Hoisting installations in which one pair of legs travels over a track placed on a low foundation while the other pair receives support from an elevated track laid on a trestle or track girder attached to the building.

SHAKING CONVEYOR – Unit which consists of a deck in the form of a trough or pan suspended from, or supported by a stationary frame and the deck is induced to oscillate, causing the material to move along at a pace and in a mode governed by the character of the oscillations, e.g., oscillating conveyors and vibrating conveyors.

SINGLE FACED CORRUGATED FIBRE BOARD – Fibre board with a flat facing of corrugated material on one side.

SINGLE FACED PALLET – A pallet consisting of one deck.

SINGLE WALL CORRUGATED FIBRE BOARD – Fibre board with a flat facing of corrugated material on both sides.

SKID – Similar to pallets except it has no bottom surface.

SKIP HOIST – Conveyor which consists of a bucket moving between guides, with the power of a cable reeved round sheaves and drums which turn through electric drives. Used for vertical movement of coal.

SLIP SHEET – A single sheet of heavy, strong, corrugated fibre board or plastic. Unit load is pulled on it and the forks of the lift truck slide underneath.

SLOTTED STYLE BOX – A box with slots, made from a single piece of fibreboard.

SOFC – A container stacked on a flat car.

SOLID FIBRE BOARD – Two or more layers of fibre board glued together to make a single sheet.

SPAN – Horizontal distance between the axes of crane track rails.

SPEED GUARD – Device which prevents the hook loads from acceleration beyond a set limit. They are usually centrifugal brakes (e.g., centrifugal disc brake, centrifugal internal block brake), hydraulic units and eddy current brakes.

SPIRAL or SCREW CONVEYORS – Unit which employs an endless helicoids screw rotating in a trough. The movement of the screw gradually moves the material to a higher location.

STABILITY OF A CRANE – The ratio of the righting and tipping moments taken about a tipping axis.

STABILITY COEFFICIENT OF CRANE PROPER – The ratio of the moment produced by the dead weight of all crane components, with the allowance for a track gradient effect facilitating the chance of
overturning, taken about a tipping axis to the moment set up by a wind pressure exceeding the safe maximum operating value taken with respect to the same tipping axis.

STABILITY COEFFICIENT OF A CRANE UNDER A LOAD – Ratio of the moment set up by the dead weight of crane components with the allowance of additional forces (wind effect, inertia at starting and stopping the hoisting, slewing and travelling motions, effect of track ground gradient) taken about a tipping axis to the moment due to the working load about the same axis.

STOP OFF CAR – A car that stops at two or more destinations to finish loading or to partly unload.

STOWAGE – Arrangement of freight in the hold of the ship.

STRINGER – Timber that runs the length of a pallet.

TANK TRUCK – A truck in which liquids are transported.

TRACTOR – A crawler or wheel mounted, self propelled vehicle designed to perform agricultural, earthmoving, road making, load carrying and other work.

TRACTOR TRAILER TRAIN – The combination of a puller unit with a train of wheeled dollies.

TRAVELLING CANTILEVER WALL CRANE – Crane arranged to travel over tracks secured to a side wall of the building.

TRAVELLING GANTRY CRANE – A crane which has a rigid four legged gantry travelling over a track laid along the work area, topping the gantry is a rotary part with a jib, a movable counter weight, hoisting and luffing units.

TRUCK – A self powered wheel vehicle used for carrying loads and people.

TRUCK CRANES – Cranes mounted on chassis of standard design or on special purpose chassis with tyred wheels.

TYPE I HAND CRANK – Unit directly linked to the load brake and requiring a constant effort in order to lower the load which descends at a rate corresponding to the rate of crank rotation.

TYPE II HAND CRANK – An arrangement to effect lowering of load at a speed exceeding that of hoisting and finds application where this mode of operation is called for by process requirements.

TWO WAY PALLET – A pallet design that permits forks or hand pallet trucks to enter from two sides only and in opposite directions.

UNITIZED LOAD – A grouping of smaller shipments that are bound together to travel as a single larger unit, also called UNIT LOAD.

UPENDERS AND DUMPERS – Specialized machines used to unload materials handling carriers at a desired location.

VACUUM LIFTER – End of line attachment, a convenient means of handling sheet stock of various kind (steel, non-ferrous metals, glass etc.) along with cartons, boxes etc. To lift a load, the vacuum cup is applied to its surface, and the vacuum generator is set into operation, creating a vacuum in the cup.

VERTICAL LIFT – A ferries’-wheel type conveyor that moves goods from the receiving area to the checking area.

WEIGHT OF A BODY – Force which the body exerts on the support due to the force of gravity.

WINCH – Equipment used for hauling, pulling, or hoisting e.g., rope and chain winches, stationary winches, mobile winches.

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