GB2189767A - Loading/unloading apparatus - Google Patents

Description

SPECIFICATION Improvements in loading/unloading apparatus This invention relates to a loading/unloading apparatus for use in loading cargo collected on land ortransported from mineral resources extraction sites into a ship and unloading the cargo from the ship in a different place.

There have been transport systems for collecting corn or other agricultural products various mineral ores orothergradularor powdery materials used in various chemical material industries in a specific place, transporting the collected matter to a site of shipment, loading the transported material into a ship, transporting the loaded material over the sea to a different place, and unloading and distributing the transported material. Various improvements have been made in these transport systems in accordance with the purpose and character of the transported material.

Usually, beltconveyorsare extensively used for these systems of transport. However, belt conveyors are usually led from a site of collection to a site of shipment, and materials must betransported to the collection site on trucks or the like across many cities and towns. In addition, in order to increase the capacity of transport on the belt conveyor, the width of the belt must be increased.

As another type oftransport, has been known to use a bucket conveyor, which employs a number of transport buckets attached to endless chains passed round upper and lower chain wheels. The bucket conveyor is used to scoop cargo collected below it and lift the scooped cargo. Unlike the belt conveyor, however, it cannot continously lift the cargo that is continously broughtto the start point ofthe lifting. In addition, it also has the same drawback as that of the belt conveyor as discussed above.

Further, forthetransport of corn, coal, chemical materials, etc., as large transport ships as possible must be used to reduce the transport expenditure.

Besides, it is necessary to provide measures for preventing the material in transit from constituting the source of dust or source of other contamination.

Further, ports are necessary for utilizing large transport ships.

A port is required at or near an iron manufacturing plant because the cost of transport is not ignorable.

The construction of a new port, however, requires expenditures to prevent the destruction ofthe environment in addition to the port construction cost.

In a further aspect, considering bare caro loaded in a ship, during a long voyage its opposite side layer portions and bottom layer portion tend to be made more compact by compacting forces exerted dueto its own weight orthe rocking and rolling ofthe ship.

The operation ofthe unloading ofthe cargo in the destination port, therefore, usually requires varying amounts of labourfor breaking the cargo depending on the extent of its compactness thatvaries with the exerted compacting force.

The unloading of the earth collected on a barge using an unloader, for instance, usually is done using bucketwheels. In this case, if the bottom ofthe barge has a width of Sm, the bucket wheel must have a diametergreaterthan 5 m in orderto be ableto transferthe earth to a belt conveyor provided on the barge.

For this reason, it is inevitable to use large size bucket wheels.

The cargo unloaded bytheunloaderdescribed above is transported using a Z-shaped transporting apparatus with boat-shaped or box-shaped buckets attached to endless chains. In this case, the cargo can be readily discharged for the bucket has a construction capable of being reversed. When a muddy cargo or like sticky cargo is handled, however, cargo often partly remains stuck to the bottom of the bucket so that the remaining material must scrape off. This requires extra labour.

Besides, mud-like matterstuckto the bucket bottom can be manually scraped offonly inefficiently, and the operation efficiency is low.

Further,the manual operation of removing the remaining muddy matter is rather dangerous.

The present invention is directed to meeting demandsforimprovingthepriorarttransport patterns described above.

According to the present invention there is provided a loading/unloading apparatus comprising: a horizontal transporting unit extending from a cargo collection place to a foundation space of a loading/unloading warf, said foundation space being provided undersea bed; a vertical bucket conveyorforvertically conveying cargo received from orto be supplied to said horizontal transporting unit; a first hopper provided in the neighbourhood of the top end of said vertical bucket conveyor; a crane for discharging unloaded cargo into said first hopper; a second hopper provided in the neighbourhood ofthetop end of said vertical bucket conveyor; and a conveyor unit for supplying loading cargo to said second hopper.

Suitably, the vertical bucket conveyor has four parallel endless chains passed round a plurality of chain wheels and a plurality of buckets coupled ata uniform interval to said endless chains are driven for excursion by a drive chain wheel, and a bucket coupling device for the vertical bucket conveyor comprising: a pair of elongate transversal coupling members respectively coupled to the front and rear ends ofthe underside of the bottom of each said bucket, one of said coupling members being secured at the opposite ends thereof to the bucket bottom, the other coupling member being pivoted to the transversal center of the bucket bottom, said coupling members being coupled at the opposite ends to said endless chains via lever mechanisms and link mechanisms.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which Figure lisa pictorial schematic view showing a transport system according to the invention; Figure2 is a pictorial schematic view showing a loading system; Figure 3 is a perspective view partly in schematic showing a pier with a continuous loader; Figure 4 is a schematic side view showing a bucket conveyor; Figure 5 is a plan view showing the same bucket conveyor; Figure 6shows the configuration of rotary sections A1,B1,C1 an D shown in FigureS; Figure 7 is a plan view showing a bucket E; Figures 8and 9 are respectively longitudinal and transversal sectional views showing the same bucket;; Figure 70 is a plan view showing the relationship between buckets E and inner and outer endless chains; Figure 11 is a side view showing the same; Figure 12 is a fragmentary view showing a bucket coupling; Figure 13 is a side view showing a chain wheel in a rotary section C3; Figure 14 is a side view showing a rotary section D; Figure 15 is a sectional view showing a loading/unloading apparatus used for the transport system according to the invention; Figure 16 is a pictorial perspective view showing a cargo ship with transporting apparatus used as part ofthe transport system according to the invention; Figure 17 is a perspective view, partly broken away, showing a different example ofthe cargo ship with transporting apparatus;; Figure 18 is a sectional view, to an enlarged scale, showing a gate; Figures 19 and 20 are respective a side view and a plan view, partly broken away, showing the cargo ship of Figure 17; Figure 7 is a schematic view illustrating the manner of co-operation of individual conveying means; Figure 22 is a schematic view showing a Z-shaped transporter; Figure 23 is a fragmentary enlarged-scale view showing the Z-shaped transporter of Figure 22; Figures24and 25areviews simiiarto Figure 22; Figure 26 is a schematic plan view showing a bucket conveyor with vibration amplitude limiter; Figure 27 is an exploded perspective view showing a bucket with coupling means;; Figure 28 is a fragmentary plan view showing the structure of vibration amplitude limiterfor a front support point; Figure 29 is a fragmentary plan view showing the structure of vibration amplitude limiterfor rear support point; Figures 30 and 31 are respectivelyfragmentary side and front views showing a coupling structure at a front support point; Figures 32 and 33 are respectivelyfragmentary side and front views showing a coupling structure at a rear support point; Figure34 is a view showing a bucketcoupling structure; Figure 35is a view illustrating the coupling between pin and bush in the bucket coupling structure of Figure 34; Figure 36 is a view showing an improved bucket coupling structure; Figure 37 is a perspective view showing a bucket; and Figure 38 is a perspective view of a bucket.

Now, the transport system embodying the invention will be described with reference to the accompanying drawings.

Figure 1 outlines an example ofthetransport system. In this system, part of mineral ore obtained in an extraction site W is transported using a bucket lifterto the ground surface for the conventional land transport, butthe rest of the ore is led by an exclusive underground conveyorto a port X. In the portX, loading system 1, which is an essential element of the invention, is working.

In an unloading port Y, the cargo is unloaded byan unloading system 7 to be led to a suitable distribution site Z.

In the case of an ore, it may be stacked bare. In the case of corn or chemical products, a tower collectorZ is usedforcollections as shown in Figure 1.

Now, the transport start site W, loading site X, unloading site Y and distributing site Z wi l l be individually described in detail.

Figure 2 shows part of the system according to the invention up to the loading site. A belt conveyor3 extends through a horizontal tunnel. At the end ofthe beltconveyor3, a hopper4and a bucketconveyor fortaking out cargo from the hopper and upwardly transporting it are provided and operatively coupled to each other.

In the case of Figure 2, the bucket conveyor 5 is led to a warf 1 which is separated from the land. Cargo is loaded from thetop ofthe warf 1 into a transport ship using a separately provided bolt conveyor orthe like.

The beltconveyor3 inthetunnel 2 need not consist ofasinglebeltconveyor, butasuitable numberof belt conveyors having a fixed length may be suitable used to coverthe length ofthe tunnel. Doing so will be convenient from the standpoint of power supply.

The bucket conveyor 5, to which cargo is supplied from the underground hopper 4, may be provided with a scraping device and other necessary devices.

The provision ofthese devices will ensure stable operation ofthe bucket conveyor 5 for long time, and the bucket conveyor 5 can transport the maximim quantity of cargo at all time. This is desired from the standpoint of reduction of the operating time. On the warf 1, the cargo that has been transported is loaded into the cargo ship 6 using a belt conveyor, for instance.

It will be understood that with the construction described above there is no need oftransporting cargo on trucks across comparatively high population coastal areas, buttransportcan be done through very convenient centralized control.

Figure3 is a partly broken-away perspectiveview showingthewarfl and neighboring equipment. The bucket conveyor 5 has a construction as shown in the side view of Fig 4. Its rotary sections Al, B1, C1 and D are shown in Figure 6.

The rotary section C1 includes a shaft34a and inner and outer chain wheels 32a and 33b secured to opposite side portions of the shaft 34a. The opposite ends of the shaft 34a are supported in bearing 33 mounted in a casing 44.

The rotary section C2 has the same construction as the rotary section Cl. The rotary section C3 also has the same construction as the rotary section C1 exceptforthat its inner chain wheels 32a are each provided with a notch 42 in a valley 41 betwen adjacent tooth as shown in Figure 13. The notch 42 serves to position a connecting member35b connecting an outer endless chain 31 band a bucket E to be described later when the connecting member 35a comes into engagement in it.

The rotary section D further has the same construction asthe rotary section C1 except for that a driving chain wheel 34c is secured to one end of shaft 34a. The driving chain wheel 32c is coupled through a speed reduction unit to a motor The shaft 34a further carries a discharging member43 secured to its central portion. The discharging member 43 is adapted to strike the bottom of the bucket E and give a shock thereto or raise the bottom,thereby discharging the cargo to the outside. The rotary section Al has opposite side aligned shafts 34b, which respectively carry outer chain wheels 32b secured to them and are supported in bearings 33.

The rotary section A2 has the same construction as the rotary section A1, and the rotation section B2 has the same construction as the rotary section B1.

In this bucket conveyor 5 of Figure 4, the rotary sections C1,A1,A2, B1, A2, B3, D and C3 are disposed in the illustrated positions, and outer endless chains 31 b are passed roundtheouterchain wheels ofthe rotary sections Cl, Al ,A2,D,C3 and C2.

Each bucket E has a front portion coupled on the opposite sides to the respective inner endless chains 31 a and a rear portion coupled on the opposite sides to the respective outer chains 31 b. In this way, a plurality of bucket E are coupled in a row to the inner and outer endless chains 31 a and 31 b. The buckets E can proceed horizontally in a horizontal transport section and they are then moved upwardly, whilst still assuming a horizontal posture, in a vertical transport section.

The notch 42 thatis provided in the valley41 between adjacent teeth of the inner chain wheels 32a in the rotary section C3 to position the connecting member 35b when the member35b is received in it, is provided for providing forsooth excursion ofthe bucket conveyor. To ensure smooth excursion, the innerand outerchain wheels in the individual rotary sections are secured to the associated shafts such thattheirteeth are staggered so that the teeth ofthe inner chain wheels will mesh with links of the inner endless chains.

Figures 7through 12 show the relation between the buckets E and the inner and outer endless chains 31 a and 31 b. The bucket E consists of a boat-like body 39 having an intermediate rubber plate 45 provided between its front and rear poritons. Its opposite side walls have bent lower ends 46. Its bottom is clamped between these bentl lower ends 46 and retainers 47. ltfurtherhasfrontand rear projecting pieces 38a and 38b upwardly projecting from the opposite side walls. These projecting pieces 38a and 38b have respective holes 37, and the front projecting pieces 38a are bolted by bolts 48 to the opposite sides. Aflap member 36 made of rubber is secured by means of an adhesive or bolts to the front portion ofthe bucket body 39.

The bucket E is coupled to the outer endless chains 31 b via a transversal rod 40 penetrating the hole 37b in the rear projecting pieces 38b and connecting members 35b fitted onthetransversal rod 40. The bucket E is also coupled to the inner endless chains 31 a by connecting members 35a fitted on to the rod 40.

The operation of the bucket conveyor will now be described with reference to Figure 4.

When the motor M is started, the inner and outer endless chains 31 a and 31 bare driven in the direction of arrows. Each bucket E is moved horizontally as shown by arrow in the lower horizontal transport section. In the upward run in the vertical transport section, the inner endless chain 31a are passed round the inner chain wheels 32 in the rotary sections s1 and B2,whiletheouter endless chains 32b are passed round the outer chain wheels 32b ofthe rotary sections Al and A2. In this section, the individual buckets E thus ascends at an interval while holding their horizontal posture. When the top ofthis section is reached, each bucket E now is moved horizontally in the direction of arrow.

Atthe rotary section D, each bucket E is U-turned into an inverted state. In this state, it is then moved horizontally. At the subsequent rotary section C3, it is turned right angles to descent in the vertical state. At the rotary section C2, it is again turned rig ht ang les to proceed toward the rotary section Cl.

The cargo such as powdery cargo that is continuously supplied from the belt conveyor 3 over to the lower horizontal transport section ofthe bucket conveyor can be charged into the individual buckets E without partly falling orthe outside by virtue of the flap member 36, which bridges the adjacent buckets E as the buckets E run beneath the discharge end of the belt conveyor 3. Each bucket E now containing cargo runs horizontallyalongthe horizontal transport path to reach the vertical transport section, where it ascends to reach the upper horizontal transport section where it runs horizontally to reach the rotary section D. At this section, its bottom is given a shock or raised by the discharging member 43, so that the content in the bucket can be discharged with only its slight portion remaining stuck to the vessel bottom.The discharged content falls onto a belt conveyor G.

The intermediate plate 45 used for the bucket E of the bucket conveyor 5 may be a rubber plate, a rubber plate with a lamination ofthin flexible metal sheets provided on the lower side ofthe rubber plate, a synthetic resin plate having elasticity and satisfactory partability, an elastic plate having a partable surface layer, etc. This plate serves to take up various metallic sounds generated during operation. Also it has a property of repelling water, and thus with a ca rgo conta ining water it permits the cargo to be discharged with little portion cargoto gathertogethertoward the center and be less stuck to the sidewalls ofthe bucket. And then the bucket is U-turned at the roraty section D, it co-operates with the discharging member43 to reduce the striking of cargo to the bottom of the bucket.

The discharging mem ber 43 may be a cyl inder having a large diameter fitted on the shaft 34a.

Further, the peripheral surface ofthe cylinder may be formed with irregularities to provide for a sort of vibrating effect.

Figures 9 through 14 show a specific construction of the bucket conveyor, which comprised a plurality of rotary sections provided in neccessary locations and endless chains passed round chain wheels in the individual rotary sections and carrying buckets using satisfactorily partableflexible material or elastic material. The rotary section atthe outlet has a shaft with a discharging member. Here, the discharging member43 serves to raise and deform the bottom of each bucket. Thus, cargo that is sticky or capable of being readily solidified can be satisfactorily separated from the bucket and discharged to the outside. With this construction, the following effects can be obtained in addition to the effects described above.

(a) Great quantities of cargo can be transported not only in the vertical and horizontal directions but also in any other direction.

(b) Since the flap member provided on each bucket serves to stride adjacent buckets in the horizontal transport section, powdery cargo can be transported efficiently without the possibility offalling between adjacent buckets.

(c) The bucket conveyor can be installed without requiring a wide installation area as in the case ofthe belt conveyor.

The construction ofthe warf 1 will now be described in detail with reference to Figure 3.

A screwfeeder 51 is provided in a transport chamber 52 formed under a sea bed. The screw feeder 51 extends between one end of a belt conveyor3 in a horizontal tunnel and a lower horizontal transport section of a bucket lifter 5. An upper horizontal transport section of the bucket lifter 5 is located above a cylindrical support 53 and is coupled to separate beltconveyor G.

A plurality of such transportsystems maybe provided, and a bucket lifter is coupled to the belt conveyor G in each system. The bucket lifter is secured to thewarfl.

With this construction ofwarf 1, cargo, for instance coal, is transported on the belt conveyor 3 to the screwfeeder 51 and isthentransferred to the bucket lifterwhose vertical section is in the cylindrical support 53. Atthe top of the bucket lifter, the cargo is delivered from each bucket to an upper horizontal transport section through the cylindrical support 53.

From the upper horizontal transport section the cargo is dropped into transport ship 6.

In the above way, the transported cargo can be continously loaded into the transport ship.

In the destination port, the cargo loaded in the transport ship is unloaded. This is desirably done using a method or apparatus which can overcome drawbacks inherent in the prior art.

Examples of the apparatus that can solve the problems encountered in the prior art are: An unloading apparatus, which can adopt itselfto any barge having any bottom depth.

An unloading apparatus, which uses a bucket lifter in lieu of a bucket wheel so that a hopper and a belt conveyor may be installed by making use of an available space in the bucket lifter to reduce the installation space as a whole.

An unloading apparatus, in which a bucket lifter can be operated by a motor-driven chain block or like lifting device so that operations at the commencement of unloading can be smoothly done.

Further, with respectto the removal of highly sticky cargo remaining stuckto the bucket bottom, an apparatus, in which a boat-shaped bucket is provide with a scraper capable of being turned in an interlocked relation to the turning of the bucket, with the freedom of motion ofthe scraper being increased with such an arrangement that an arm of the scraper is moved by a cam, is desired.

Figure 15 shows a specific unloading apparatus according to the invention. This apparatus has both unloading and loading lines 103 and 106 provided on aware 107. The unloading line 103 includes a crane 101 and a hopper 102. The loading line 106 includes a hopper 104 and a telescopic shoot 105. The warf 107 is constructed such that a cargo ship can be anchored alongside it. A bucket lifter or like conveyor 108 is provided in the warf 109 for conveying cargo to and from a space defined in the foundation orsea bed.

A horizontal converyor 109 is provided such that it extends from the space in the foundation to a cargo yard on land.

The vertical and horizontal converyors 108 and 109 are provided in a water-tightwarf and tunnel spaces.

In view of trend for increasing size and scale of transport ships the warf 107 suitably extends at least about 1 7m from the sea surface to the sea bed and has a heightof about 50m form the sea level to the top of the crame 101. The effective operating length ofthecrane 101 may be about 37 m in orderto be able to be used for 60,000=ton bulk cargo ships, for instance.

The apparatus described above performs an unloading operation of 1,200 tons/h (i.e.,1,200m/h) at the most.

The unloading apparatus of Figure 15 can undertake the loading of cargo as well as mentioned above, and its construction will now be described in detail.

To permit both unloading and loading, a hopper 104 is separately provided over the ward 107 on one side ofthe top of the vertical conveyor 108. A small-scale horizontal conveyor, e.g., a belt conveyor, 117 is provided benearth the hopper 104.

Cargothat is suppliedfrom the hopper 104tothe horizontal conveyor 117 is thus loaded into a bulk cargo ship 112, for instance, th roug h the teiescope shoot 105.

The functions of various components of the apparatus will now be described in connection with the case of unloading.

Forunloadingcargofromthebulkcargoship 112 anchorded alongsidethewarf, the crane 101 is moved up to an intended position, and then its top is appropriately positioned.

A grab 113 which is suspended from the top of the crane 101 is then lowered into the ship and operated to grab cargo. Then it is raised, and moved by horizontal grab means ofthe crane 101 to a position rightabovethe hopper 102. The grasped cargo is then discharged into the hopper 102.

The cargo discharged into the hopper 102 is transported by feeder 114 to be fed into the hopper 1 l5forthevertical conveyor 108 such as a bucket conveyor. The cargo is thus conveyred by the vertical conveyor 108tothe bottom ofthewarf 107.

Cargo is then transferred to the horizontal conveyorl09tobetransportedthroughtunnel 111 to the cargo yard on land.

The unloading apparatus, or more correctly loading/unloading apparatus, as described is constructed such that its main components can be used for both loading and unloading. Forthe loading,thevertical and horizontal conveyors 108 and 109 are operated in the opposite direction. An end portion of the horizontal conveyor 109, which is provided to co-operate with a hopper 118 provided at the lower end of the vertical conveyor 108, may be adapted such that its slope angle is variable for loading and unloading operations.

Thewarf 107 should of course have a structure which will never be collapsed when various equipments such as crane 101 are installed on it. A concrete structure with a concrete wall thickness of about 5m will withstand the weight of various equipments which are necessary for operation at a rate of 1,200 tons/h as noted above.

A bulk cargo ship which is provided with a loading/unloading apparatus according to the invention will now be described with reference to Figure 16. The ship comprises a ship body A, rails B, supports C provided on the rails B, a transversal cargo support member D provided on the supports C,a screw conveyor or beltconveyor E supported on the transversal cargo support member D and a bucket conveyor Fwhich is provided between the conveyor E and hold.

The bucket conveyor F has a cover as illustrated, but the cover may be omitted so that the conveyor is exposed. The bucket conveyor F may be freely displaced in the longitudinal direction ofthe transversal conveyor E. The conveyor system that comprises the bucket conveyor F and transversal conveyor E can be freely displaced along the rails B in the longirudinal direction ofthe ship. The bucket conveyor Fthus can be broughtto a desired position in the hold for loading or unloading of cargo in that portion ofthe hold.

The ship body A itself does not require any special equipmentforloading or unloading, and it only need be capable of ballast adjustment according to graduallyvryingweightofthecargo.

The rails B are laid on the deck ofthe ship body A.

They may be of ordinary type for guiding the conveyorsystem along them. The supports C havea sufficient height for the transversal cargo support member Dto be moved over various equipments provided on the deck.

Of course, the supports C should withstand the sum ofthe weights of the transversal cargo support member D, transversal conveyor E and cargo being transported thereon. The transversal cargo support member D is provided forthe purpose of supporting the transversal conveyor E, and it may have a plate-like form or any other suitable form.

The bucket conveyor E may be ofordinarytype.

The arrangement shown in Figure 16 is for the operation of unloading cargo from ship to land. For loading cargo into ship, the land side end ofthe transversal conveyor is disposed beneath a land side hopper.

Adifferentexample of bulkcargo ship is shown in the perspective view of Figure 17. In this instance, the ship has first conveyor means 201 extending in the hole inthe longitudinal direction of the ship, a pairof second conveyor means 202 provided on the opposite gunnels and capable of rotation in a horizontal plane, and third conveyor means 203 coupling together the first and second conveyor means. The fist and second conveyor means 201 and 202 convey cargo in the horizontal direction, while the third conveyor means 203 conveys cargo in the vertical directions.Drive means 204 can rotate each second conveyor means 202 by 90" in the horizontal plane via wires from the accommodated position, in which it is parallel to the tunnel, to a perpendicular position orfrom the perpendicular position to the accommodated position. Reference numeral 205 designates a hold for containing granularcargo. The bottom ofthe hold 205 is constituted by a numberof aslant members, along which the granular cargo may be supplied onto the first conveyor means 201.

The lower outlet end each aslant member is provided with a gate 206. Reference numeral 207 designates hatch covers. Figure 18 shows an example of the gate 206. The gate 206 has a gate member 261 which is rotatable about a shaft 260. The gate member 261 is driven by a cylinder 263 via a lever 262 integral with the gate member.

Figure 19 is a side view, partly broken away, showing the bulk cargo ship of Figure 17 and Figure 20 is a plan view of the same. In this example, belt conveyors are used as the first conveyor means, and a bucket lifter is used as the third conveyor means.

The belt conveyor serving as each second conveyor means 202 is accommodated inthetunnel when itis not used for loading or unloading. The belt conveyor 202 may be turned byan angle 0 of 900 atthe most about an axis 209 of rotation. It may consist of a plurality of stages so that it can be extended and contracted. The extension and contraction of the belt conveyor may be caused through the wires 208.

Figure 21 shows the coupling betweenthebeltthe belt conveyors 201 and bucket lifter 203. As is shown, cargo is charged from the belt conveyors 201 into a hopper 210 to be supplied to the bucket lifter 203.

The bucket lifter 203 is similarly coupled to the belt conveyors 202.

The operation ofthe bulk cargo ship with the conveyor system described before in connection with Figures 17 through 21 will now be described. A casewill be taken, in which the bulk cargo ship is full of cargo and is anchored alongside warffor unloading. Afterthe ship has been anchored alongside the warf, the second conveyor means 202 in the leftgunnel, in the instant case, isturned 900 by the drive means 204, and it is also extended if necessary, so that its end is broughtto a loading/unloading site. Then, the first to third conveyor means are operated, and the gates 206 are opened. Cargo in the hold 205 thus starts to fall onto the first conveyor means 201.The openings of the gates 206 are controlled depending on the state of cargo in the hold such that cargo remains uniformly, thus minimizing the tilting ofthe ship. The first conveyor means 201 conveys the supplie cargo along the bottom of the ship and transfers it to the third conveyor means 203. The third conveyor means 203 conveys the cargo to a high level position and transfers it onto the second conveyor means 202. The second conveyor means 202 conveys the cargo to site of collection.

The unloading operation described above is entirely carried out automatically and requires neither manual adjustment nor manual help. In addition, no loading/unloading equipment is required on the side ofthe port. Thus, automatic loading and unloading can be carried out at any port.

The bulk cargo which is unloaded onto land in the above way, is transported buy a horizontal transporter, and also by a Z-shaped transporter where there is a level difference, to a storage place.

As the horizontal transporter may be used the conventional belt conveyors, screw conveyors or other conveyors.

The Z-shaped transporter, which is utilized in case where there is a level difference, should be one, which need not be stopped frequentlyforthe purpose of cleaning.

Figure 22 shows an example ofthe Z-shaped transporter. It has a frame 300, which accommodates endless chains 305 with a number of buckets 306 coupled thereto. Each bucket 306 can transport cargo supplied from a screw conveyor 301 for instance, along the endless chain path and discharge it as it is U-turned round a chain wheel 302 at the righttop of the endless chain path.

Ahopper303 is an example ofmeansfor transferring the cargo received from the Z-shaped transporter. The endless chains 305, are driven from a motor304. In case when the cargo transported by each bucket is sticky, it may partly remain stuckto the bucket (i.e., inner side and bottom walls ofthe bucket) as the bucket is U-turned. For removing the residual content, a scraping device as shown in Figure 23, differentfrom that shown in Figure 22, is provided. It has a scraper 307 and a cam 308, these being located to face the underside of a bucket right after the bucket is U-turned. The scraper 307 has an arm 309 which is rotatable about its fulcrum point 310. A scraping blade 311 is mounted on the free end ofthe scraper arm 309.The scraping blade is suitably made of an elastic material such as rubber, and its width is suitably such that it can be in frictional contactwith the opposite sides ofthe bucket.

The scraperarm 309 has a cam roller 312 provided at a suitable position and in rolling contact with the cam 308 with the rotation of the cam 308, the scraping blade 311 undergoes a see-saw motion with the arm 309. With this motion,the matterstuck to the inner surfaces of the bucket is scrapped off as the bucket proceeds pastthe blade 311.

Powerforcausing rotation ofthe cam 308 in an interlocked relation to the process of the bucket, may be conveniently obtained form the chain wheel shaft as is shown. However, it is of course possibleto use a separate chain wheel shaft for deriving the driving torque.

With the above construction of the scraping device, it is possible to design the shape ofthe scraping arm 309 and cam 308 to meet the shape of the inner surface of the bucket and the speed of progress thereof. Thus, it is applicable not only to the boat-like bucket as is shown but also to a bucket of any other shape such as a semi-cylindrical bucket.

As has been described in the foregoing, with the unloading apparatus according to the invention the following effects can be obtained.

Sincetheunloaderusesthe bucket lifter, unloading operation can be donefrom any level in the interior of the cargo ship, which is most desirous for the unloading operation ofthistype on a mass production scale.

The hopper and belt conveyor can be installed in the available space in the bucket limiter minimisethe size of the overall apparatus. This is advantageous from the standpoints of the assembly, transport, storage and disassembly ofthe unloader.

Aside from the above main advantages, the use of the Z-shaped buckettype transporter having a function of automatically scraping residual content offthe bucket during operation ofthetransporter makes it possible to obtain a continous cargo unloading and transporting apparatus, which can be operated continuously for a long time.

The Z-shaped transporter described above in connection with Figure 22 has a certain problem, which will now be described. Figure 24 is a view similarto Figure 22 showing the same Z-shaped transporter except for that additional reference numerals are provided. Reference numeral 300 designates a frame of the Z-shaped transporter.

Reference numerals 312 and 313 designate chain wheels atthe bottom andtopendsoftheZ-shaped transporter, respectively. Reference numerals 314, 315, 316a, 316b, 317a and 317b designate chain wheels at intermediate bent portions of the transporter path. Each of the chain wheels 312,313, 314 and 315 hasfourjuxtaposed chain wheels supported on a common shaft. Four parallel endless chains 305a to 305d are passed roung these four chain wheels. The outertwo endless chains 305a and 305b are also passed round the chain wheels 31 6a and 317a. The innertwo endless chains 305c and 305d are also passed round the chain wheels 31 6b and 31 7b. Each of the buckets 306 has its rear opposite side support points coupled to the respective two inner endless chains 305c and 305d.

The chain wheel 313 atthetop end is driven by drive motor 304, thus causing excursion of the individual buckets 306 along the frame 300. Reference numeral 301 designates a conveyor which is coupled to the bottom end of the Z-shaped transporter. Reference numeral 303 designates a hopper, which receives cargofallingfromthetopendoftheZ-shaped transporter.

In this Z-shaped transporter, which can serve as bucket lifter, the distances between the chain wheels 312 and 316a, between chain wheels and 317a, between chain wheels 317a and 313, between chain wheels 313 and 315, between chain wheels 315 and 314 and between chain wheels 314 and 312 are different, and also the weight (or more correctly mass) between the chain wheels ofthe individual pairs are different depending on the amount or density of cargo contained in the buckets. Therefore, complicated resonant frequencies of the individual of chain wheels occur and have adverse effect on the operation of the bucket lifter. The resonant frequencies, which occur in a large number, also vary depending on conditions, underwhich the bucket lifter is used.Further, waves, winds, earthquakes, etc., which are causes of vibrations, are natural phenomena or at least depend on natural phenomena, so that they cannot be accurately forecast. Therefore, it is impossible to eliminate the adverse influence noted by means of controlling the resonant frequencies. It is more realistic to cope with the adverse influence by means of restricting the amplitude ofvibrations.

Further,the angle, at which the chains are passed round the chain wheels 31 6a, 316b, 31 7a 317b, 315 and 314, is obviously 90" and is limited to 90" so long as the instant structure is employed. The number of rollers of a roller chain which is passed round the chain wheel over the angle of 90" noted above is small, so that detachment of chain is liable in the event when a large amplitude ofvibration is exerted or built up due to resonance.

This drawback is particularly pronounced in case where the bucket lifter is intalled on a ship.

Figure 25 shows a bucket lifterwith vibration amplitude limiter according to the invention. The construction and operation ofthis bucket lifter is substantially the same as the bucketliftershown in Figure 24 except for that the vibration amplitude limiter can overcome the drawback discussed before. In the Figures, like parts are designated by like reference numerals, and their description is omitted.

Figure 26 is a sectional view, to an enlarged scale, taken along line S-S in Figure 25. Figure 27 is an enlarged-scale exploded perspective view showing a bucket and means for coupling the bucketto inner and outer chains. Figure 28 and 29 are enlarged-scale plan views illustrating vibration amplitude limiter at front and rear support sections of the bucket, respectively. The bucket 306 is made of steel sheet and has a shape like a boat. It has a flap member324 of an elastic material, e.g., rubber, projecting from the rear end of its body.The flap member 324 engages the front end ofthe succeeding bucket when the buckets are running pasta spot, atwhich cargo is continously discharge from the conveyor 301 at the bottom ofthe Z-shaped bucket lifter, thus preventing the cargo from falling through otherwise formed gap between adjacent buckets to attach to endless chains and other driving parts and cause wear thereof. If desired, the bottom ofthe bucket is angularly notched or removed, the opening thus formed is covered buy a bottom member 325 of an elastic material, e.g., rubber, which is mounted by means of a mounting frame. In this case, as the bucket 306 is inverted round the chain wheel 313 at the top end, an urging roller326 provided on the shaft chain wheel 313 raises the elastic bottom member 325.In this way, viscous cargo may be discharged satisfactorily. A bracket 327 is mounted on the bucket 306 at a front support point on each side. It is secured to the bucket 306, and it has an upper notch 328a,a pin hole329formed in a lower portion and a stopper 330 projecting form a rear portion. A link member331 is rotatably mounted in the bracket 327 with its pin 331 has a front shaft 334 secured to its upper portion and having a spacer 333.

The front shaft 334 is coupled to the associated inner endless chain. The endless chain is fitted on the spacer portion 333 ofthe front shaft and retained by fitting a nut 335 on the shaft.

As shown in Figure 28, a pair of guide members 346 are provided on stationary supports 348 secured to the frame 300 such that they face each other on the opposite sides of and at a slight spacing from a roller 350 of each inner endless chain, i.e., chain 305c in the illustrated case. The guide members are most suitably made of a highly lublicant material, e.g., and oil-containing alloy. The roller 350 of the chain, which is the guided member, may be made of a material having high rigidity. The guide members 346 and supports 348 constitute the vibration amplitude limiter.

Referring back to Figure 27, a bracket 336 is secured to the bucket 306 at a rear support point on each side. A link 339 is rotatably mounted on the bracket 336 with its pin 338 inserted in a pin hole 337 formed in the bracket 336. The bracket 336 may be of the same shape as the bracket 327 at the front support point. In the instant example, however, it has anotch328bformedin itsfrontportion. Itissecured to the associated side plate ofthe bucket 306.

A stopper 340 projects outwardly from the side plate ofthe bucket on the rear side of the bracket 336.

The link339 has a rearshaft341 securedtoitsupper portion. An arm 342 iscoupledtothefront rearshaft 341. It strides the inner endless chain 305e and extends upto the outer endless chain 305a. The outer endless chain 305a is coupled by a bolt 343 and a nut 344 to the outer end of the arm 342. The arm 342 is coupled to the rear shaft341 by fitting its hole 346 on the shaft 341 and clamping a nut 345 thereon.

As shown in Figure 29, a pair of guide members 346 are provided on the opposite sides of roller350 of the endless chain 305a like the case of the front support point described above. In this case, however, stationary supports 347 have a smaller length than the supports 348. When the bucket 306 is being raised in its horizontal state, the arm 342 is in its position shown in Figure 29, which is at an angle of 900 from its position shown in Figure 27.

When the bucket 306 is on the descent, it is in a vertical state. In this path, the inner endless chain 305c extends on the innerside of and parallelwith the outer endless chain 305a. Here, it extends through a notch 342bformed in the arm 342. The right half of Figure 26 illustrates the arrangement of the guide members in this case. In this case, the guide structure for the outer end less chai n 305a is the same as shown in Figure 29. In the guide structure for the inner endless chain 305c, on the other hand, one side ofthe notch 342a of the arm 342 serves as a guide, and a single support 349 serves as both the supports 347 and 348.

The guide members 346 and supports 347,348 and 349 constitute the vibration amplitude limiter 351.

The vibration amplitude limiter 350 as described above is shown provided at the position corresponding to the line S-S in Figure 25. However, it may be provided at any position of the endless chain excursion path exceptforsections passing round the chain wheels.

In the vibration amplitude limiter,the guide members 346 guidethe rollers of the endless chains 305a to 305d. The chain rollersthus roll over either guide member, so that the coefficient offriction is low.Thus, it is possibleto expectsmooth rotation of the rollers and smooth excursion ofthe endless chains. Besides, the vibration amplitude limiter has no effect on the passage ofthe buckets at all.When the amplitude of vibration of the endless chain tends to be increased due to application of external vibrating force such as waves, winds, etc. or due to resonance caused by shocks, etc. the guide members ofthe vibration amplitude limiter suppresses the vibration of rollers to limitthe amplitude ofvibrations. Thus, cargo being conveyred by the buckets will neverfall thereof nor the buckets will strike the frame due to vibrations.

Further, the vibration amplitude limiter has the same function as a mechanism with guide sprocket wheel, which is so referred to in chain conduction mechanics, so that it can reiiably prevent detachmentofchainsfrom chain wheels.

This meansthatthe bucket lifter with vibration amplitude limiter permits stable conveying operation when used on a ship oron a land place which is subjectto vibrations. Besides, it eliminates the need for vigil personnel that is otherwise necessary for operation in such circumstances, so that it permits saving of man-hour.

Especially, although it has been sometimes impossible to use the usual bucket lifter on a ship for loading and unloading depending on the status of waves, the bucket lifter described above according to the invention can be stably operated even in such circumstances.

Now, a different example ofthe coupling of bucket to chain will be described with reference to Figures 30 through 33.

Figures 30 and 31 show a front support point coupling mechanism. Reference numeral 401 designates a mounting member, which is integral with bucket 306 and also serves as reinforcement member. A pipe 402 is coupled buy a pin 403 to the center ofthe mounting member 401. The pipe 402 is rockable about the pin 403. A shaft 404 is loosely fitted in the pipe 402. A lever 405 is secured by means of welding to an end of the shaft 404 projecting from the pipe 402. A shaft 406 is secured by means of welding to the lever 405. The lever 405 and shafts 404,406 integral with each other are rotatable with respect to and removably coupled to the pipe 402.

The shaft 406 has a tapered end portion 408. The associated endless chain, e.g., chain 305b in the illustrated case, is coupled to the tapered portion 408 and retained thereon by a washer409 and a pin 450.

While the lever 405 is rotatable about the shaft 404, its rearward rotation is restricted by a stopper407 which is secured to the associated side of the bucket 306.

Figures 32 and 33 show a rear support point coupling mechanism. A mounting member 501 is secured to bucket 306, and it supports a pipe 502. A separate mounting member 503 is also secured to the bucket. It is provided notfor shring load, but it is provided for the purpose of preventing warping of the pipe 502.

A shaft 504 is loosely fitted in the pipe 502. A lever 505, a bearing box 508, an arm 509 and a shaft 506 are made integral by means of welding to an end of the shaft 504 projecting from the pipe 502. The integral assembly is rotatable with respectto and removably coupled to the pipe 502.

The endless chain 305a is coupled to the shaft 506 in the same manner as that in which the chain 305b is coupled to the shaft 406 noted above. A stopper 507 is secured to the bearing box 508 which is integral with the lever 505. This structure is similar to the relation between the lever 405 and stopper 407 noted above.

The shaft 506 integral with the arm 509 is rotatably supported in a bearing provided in the bearing box 508.

Referring to Figure 24 again, in a section of bucket excursion path between the chain wheels 31 6a and 316b on one hand and chain wheels 317a and 317b on the other hand, the four chains 305a to 305d extend such that they pass through the respective corners of a rectangle in a horizontal plane. In this section of path, each bucket 306 is coupled to the four chains by the respective four coupling mechanisms, i.e., a pair of front support point coupling mechanisms 400 and a pairofrearsupport pointcoupling mechanisms 500. Bythiscoupling, the bucket 306 is held in the horizontal state while it is raised.Since the chain 305a extends vertically in this section of path, the arm 509 and shaft 506 ofthe accosiated rear support point coupling mechanism 500 are at right anglesto theirorientation shown in Figure 33. Also, the arm 405 in the front support point coupling mechanism 400 and bearing box508inthe rear support point coupling mechanism 500 are capable of engagement with and disengagement form the respective stoppers 407 and 507, while the bucket 306 is coupled in the horizontal state bythe four coupling mechanisms to the respective chains, it is generally difficult to define a plane byfour points. Generally, the weight ofthe bucket is not uniformly shared by the four chains due to such causes as mounting errors and different amounts of elongation ofthe chains. In the instant coupling system, the pipe 402 which is common to the two front support point coupling mechanisms 400 is rockably coupled to the central pin 403.That is, although the bucket 306 is designed to be supported by the four chains (and four coupling mechanisms), its weight is actually three support points, i.e., the mounting members 501 of the rear support point coupling mechanisms 500 (on the opposite sides of the bucket) and the common center pin 403 ofthe front support point coupling mechanisms400.This coupling system meets thetheoryof defining a plane by three points. (The mechanical structure ofthis support system will be hereinafter referred to as three-point support structure).

In the section ofthe bucket excursion path extending form the chain wheels 317a and 317b past the chain wheels 313, 315, 314and 312tothe chain wheels 31 6a and 316b, the buckets 306 are moved just like a cargo train. In this state, the coupling mechanism 400 and 500 are as shown in Figures 25 through 33. in the descent section of the bucket excursion path between the chain wheels 315 and 314,thesupport points on the side ofthe bucketand those on the side of the chains are off-set by mount corresponding to the length of the arms 405 and 505.

The stoppers 407 and 507 are thus in engagement with the arms 405 and bearing boxes 508 and receiving the load of the bucket. If the load is shared non-unifdrmlybythesupportpointsdueto non-uniform elongation ofthe chains or other causes, a stopperwil I bear greaterthan the force exerted to any other stopper. In long use, permanent stresses are produced atthefoursupport points, and eventually the load is shared uniformly by the four support points. In other words, the coupling system shown in Figures 30 through 33 has a function of automaticallyuniformalizingthesharing of load among thefoursupport points of the bucket.

The effectiveness ofthis coupling system is summarized as follows.

(1) Since the coupling system is ofthethree-point support structure, it minimizes the tilting ofthe bucket. The four chains uniformly share the load and uniformly undergo elongation. Thus, the chains can pass round the chain wheels with increased smoothness. These features permit stable operation for long time.

(2) The sharing of load is automatically uniformalized.

(3) The shafts 404 and 504 of the respective coupling mechanisms 400 and 500 are loosely fitted in the pipes 402 and 502. This structure permits very ready replacement of the bucket 306 or replacement of the arm of coupling mechanism, which is desired for convenient maintenance.

(4) Further, the loose fitting of shaft in pipe permits insertion of shaft to an extent substantially equal to one half ofthe width of the bucket. Thus, it is possible to eliminate such inconveniences as partial contact of shaft and occasional detachment thereof while assuring the effectiveness of the above items.

The chains are subject to permanent elongation due to wear as they are used for long time.

Accordingly, means for making chain elongation uniform is necessary.

Further, in order to facilitate the operation of coupling a bucket to chains, the link pitch of which is notuniform, it should bepossibletoreduceor increase the distance between the front and rear support points ofthe bucket.

Referring to Figure 34, a pin 601 outwardly projecting from a side wall of bucket 306 is loosely fitted in a bush 602 projecting from the associated chain. The inner periphery of the bush 602 engages substantiallythe lower halfofthe pin 61 overthe length Xthereof extending in the bush 602 for bearing the load.

When the transporter is used frequently, extra clearance is naturally produced between the pin 601 and bush 602. In consequence, the state of engagement between the pin 601 and bush 602, which is normaily as shown in Figure 35A, would be changed to that as shown in Figure 35B in the event of vibrations ofthe bucket 306 caused by any cause.

The state shown in Figure 35B is very undesired from the standpoint of the safety.

Similar state would also take place in case where a pin is provided on the side ofthe chain and a sleeve-like member is provided on the side of the bucket.

Figure 36 shows a chain which can solve the problem discussed above.

A link of chain 603 has a hole 605formed atthe central position, and a bush 606 is fitted in the hold 605 and secured to the link. The bush 606 is preferably made oftenacious steel.

Apin,for instance the pin 601 shown in Figure 34, projecting from the bucket, is fitted in the bush 606 over the entire length thereof. In this structure, the load is born by the entire width ofthe chain 603. In this case, local wear of the pin and bush is extremely reduced compared to the case of arrangementof ofarrangement of Figure 34. In addition, smoother rotation can be guaranteed.

Figure 37 shows a perspective view of an example of bucket 306. The transporter requires sufficient supervision for its operation. In this example, the bucket body has a glass window 306a provided on each side wall. The glass window 306a will facilitate the supervision of the state of cargo being conveyed and permit early detection offaultiness. The location and shape ofthe glass window may be suitably changed to suit the operation.

As the material of the glass window may be used highly transparent synthetic resins as well as transparent glass.

The bucket body may be painted with a paint of a color, which is in good contrast to the color ofthe cargo being conveyed. Doing sofurtherfacilitates the supervision ofthe cargo being conveyed through the window.

Further, only one ofthe plurality of buckets used in the transporter may be painted with paint of a different color from that for the other buckets. Doing so permits ready confirmation of the number of excursions and also position of a given bucket.

Further, the buckets in the transporter may be painted with paints of different colors corresponding to different capacities or kinds of cargo. This permits increase of operation control efficiency and improvement of safety control in addition to giving an aesthetic effect or fashionablefeature.

Moreover, the bucket body may be made of a synthetic resin depending on the type of cargo conveyed. The synthetic resin bucket will permit weight reduction, increased mass production control property and cost reduction of the transporter. Further, where the bucket is made of a transparent synthetic resin, the supervision may be extrem ely faci I itated .

Claims (31)

CLAIMS:

1. Aloading/unloadingapparatuscomprising: a horizontal transporting unit extending from a cargo collection place to a foundation space of a loading/unloading warf; said foundatin space being provided undersea bed; a vertical bucket conveyor for vertically conveying cargo received from orto be supplied to said horizontal transporting unit; a first hopper provided in the neighborhood ofthe top end of said vertical bucket conveyor; a crane for discharging unloaded cargo into said first hopper; a second hopper provided in the neighborhood of the top end of said vertical bucket conveyor; and a conveyor unitfor supplying loading cargoto said second hopper.

2. The loading/unloading apparatus according to claim 1, wherein said horizontal transporting unit includes a titable conveyor supplying cargo to and receiving cargo from said vertical bucket conveyor.

3. The loading/unloading apparatus according to claim 1, wherein said vertical bucket conveyor is driven by a reversible motor.

4. The loading/unloading apparatus according to claim 1, wherein said vertical bucket conveyor includes: a plurality of boat-like buckets; four endless chains simultaneously driven for moving said buckets; a plurality of chain wheels, said chains being passed round said chain wheels; each said bucket being coupled at both side front and rear support points to said respective endless chains, said endless chains being passed in parallel round juxtaposed chain wheels of each of said chain wheels, said both side front support points being coupled to the outertwo of said four chains, said both side rear support points being coupled to the inner two of said four endless chains, each said bucket being moved With its open top up along a conveying path of its excursion, said bucket being inverted atthe end of said conveying path and moved in a vertical posture parallel to said endless chains along a vertical return path; and a cargo discharging member provided on a shaft ofthe chain wheel at the end of the conveying path, said cargo discharging member serving to cause deformation or give a shock to a flexible bottom of each said bucket passing round said conveyor path end chain wheel so that cargo in the bucket is completely discharged at the conveying path end.

5. The loading/unloading apparatus according to claim 4, wherein said vertical bucket conveyor further includes scraper means for scraping off cargo remaining stuckto the bottom and sides of each said bucket when said bucket is inverted.

6. The loading/unloading apparatus according to claim 5, wherein said scraper means is driven from the shaft is driven from the shaft of said conveyor path end chain wheel.

7. The loading/unloading apparatus according to claim 5, wherein said scraper means is made of rubber or like elastic material.

8. The loading/unloading apparatus according to claim 1 ,wherein said horizontal transporting unit is a belt conveyor.

9. The loading/unloading apparatus according to claim 1, wherein said crane includes a vertically movable grasping bucket.

10. The loading/unloading apparatus according to claim 9, wherein said vertically movable grasping bucket is suspended from said crane and movable along said crane.

11. The loading/unloading apparatus according to claim 1, wherein said conveyor unit is a belt conveyor.

12. The loading/unloading apparatus according to claim 1, which furthercomprises a telescopic shoot capable of being extending from said conveyor unit.

13. The loading/unloading apparatus according to claim 12, wherein said telescopic shoot is slightly flexible.

14. The loading/unloading apparatus according to claim 4, further comprising bucketcoupling device for said vertical bucket conveyor, the coupling device comprising a pair of elongate transversal coupling members respectively coupled to the front and rear end ofthe underside of the bottom of each said bucket, one of said coupling members being secured at the opposite ends thereof to the bucket bottom, the other coupling member being pivoted to the transversal center of the bucket bottom, said coupling members being coupled at the opposite ends to said endless chains via lever mechansims and link mechanisms and linkmechanisms.

15. The loading/unloading apparatus according to claim 14, comprising vibration amplitude limiting meansforguiding rollers ofsaid endless chains, said vibration amplitude limiting means being provided beforeand/oraftersaid chain wheels and/or intermediate positions between adjacent chain wheels.

16. The loading/unloading apparatus according to claim 15, which is installed on a cargo ship.

17. The loading/unloading apparatus according to claim 4, wherein each said bucket has a flapping member capable of engaging the succeeding bucket.

18. The loading/unloading apparatus according to claim 17,wherein said flapping memberis made of a flexible material.

19. The loading/unloading apparatus according to claim 4, wherein each said bucket has a bottom made of an elastic material and a chain wheel provided at a discharging end, at which each bucket is inverted round said chain wheel, is provided with an urging rollerfor urging the elastic bottom ofthe bucket.

20. The loading/unloading apparatus according to claim 4, wherein each of said plurality of boat-like buckets has opposite side coupling points coupled to the inner two of said parallel endless chains and opposite side rear coupling points coupled to the outertwo of said endless chains, and a frame accommodates said endless chains, chain wheels and buckets.

21. The loading/unloading apparatus according to claim 20, wherein each said bucket has a link spaced apart a predetermined distance from a corresponding chain and rotatable about an axis extending beneath the bottom of a bucket, a shaft extending from the other end of said link, and a stopper for restricting the rotation of said link.

22. The loading/unloading apparatus according to claim 21, wherein said link is rotatably mounted in a bracket secured to the sidewall of the bucket and said shaft does not penetrate said bucket.

23. The loading/unloading apparatus according to claim 22, wherein said bracket has a notch for allowing rotation of said shaft.

24. The loading/unloading apparatus according to claim 23, wherein a link provided art a rearcoupling point has an arm striding an inner endless chain and coupled to an outer endless chain.

25. The loading/unloading apparatus according to claim 21, wherein said said bucket has a pin outwardly projecting from each side wall and loosely fitted in a bush provided in a link of a chain and extending over the entire width of the link.

26. The loading/unloading apparatus according to claim 25, wherein said pin or bush or both ofthem are made of tenacious steei.

27. The loading/unloading apparatus according to claim 4, wherein each said bucket is made of a transparent material at least for a portion corresponding to a supervising point.

28. The loading/unloading apparatus according to claim 4, wherein each said bucket is made of a synthetic resin.

29. The loading/unloading apparatus according to claim 4, wherein a portion of said frame is made of a synthetic resin.

30. The loading/unloading apparatus according to claim 29, wherein a portion of said synthetic resin istransparentorcolored.

31. A loading/unloading apparatus constructed, arranged and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.