GB2177073A - Laying paving blocks - Google Patents

Abstract

An array of blocks arranged in a herringbone pattern is produced by apparatus (Figure 4) comprising two sets of rams (13, 17) arranged at right angles to each other. The sets of rams operate alternately to push blocks (15, 19) into position, in herringbone pattern, on a table (8) and the arrays of blocks are then stacked to form pallets. A machine (Figure 8) for paving a surface has a chute (44) onto which arrays of blocks are fed in succession from pallets (68) on a platform (42). The blocks form a continuous strip on the chute (44) and slide down onto the surface to be paved as the machine moves over the latter. The machine moves in steps, each corresponding in length to the length of an array of blocks, and can also be used to deposit a layer of sand prior to the blocks and, subsequently, to embed the deposited blocks.

Description

SPECIFICATION Laying paving blocks The present invention relates to the laying of paving blocks, and to the production ofarraysofblocksfor use in paving.

When a large area is being paved, itistime- consuming and expensive to lay individual paving blocks by hand. Consideration has,therefore, been given to the possibility of using larger paving arrays (known as "layers") comprising a plurality of individual blocks which are handled and laid mechanically as a unit. It has been found, however, that expected savings in time and money are not, in practice, achieved because a substantial amount of manual labour is still required to overcome difficulties in handling the layers and aligning them with the blocks already laid.

Further difficulties arise when it is required that an area should be paved in a herringbone pattern using blocks which are supplied in a standard form of pallet, that is, a pallet in which the blocks in each layer are arranged side-by-side in parallel rows and end-to-end in parallel columns. Although such a pallet could be used in mechanical laying to produce a stretcher bond pattern by displacing alternate columns of blocks, it does not lend itself readily to the mechanical laying of blocks in a herringbone pattern.

It is an object ofthe invention to enable pallets of blocks to be produced, in which the layers of blocks are arranged in a herringbone pattern. It is also an object ofthe invention to enable blocks (which may be arranged in a herringbone pattern) to be laid more easily and more quickly than has previously been possible.

The present invention provides apparatus for producing an array of blocks, in which the blocks are arranged in a herringbone pattern, the apparatus comprising a pair of feeding mechanisms arranged at right angles to each other, and each operableto supp- ly blocks in staggered formation to a common location to produce the said array. Advantageously, each feeding mechanism is arranged to supply blocks from an array of blocks in standard form, by which is meant an array as previously described in which the blocks are arranged side-by-side in parallel rows and end-toend in parallel columns.

In embodiments of the invention described herein, each feeding mechanism is operable to supply a plurality of blocks simultaneously to the common location. More particularly, each feeding mechanism is operable to supply the plurality of blocks from alineof blocks arranged side-by-side and to displace some at least ofthe blocks relative to the remainderto product the said staggered formation.

Apparatus in accordance with this aspect ofthe invention can be used to produce a plurality of individual arrays of blocks, in each of which the blocks are arranged in a herringhone pattern. The arrays, which can be assembled into pallets, may subsequently be used to pave a surface.

Alternatively, apparatus in accordance with this aspect of the invention may form part of a machine for paving a surface, the apparatus being used to produce a plurality of individual arrays of blocks, which are deposited by the machine on the surface to be paved.

The present invention further provides apparatus for laying paving blocks, including meansforforming the blocks into a continuous strip and depositing the strip on the surface to be paved. The forming means may be operable to position individual arrays of blocks end-to-end to form a continuous strip: the blocks in the arrays may be arranged in a herringbone pattern, in which case the arrays may be produced by apparatus in accordance with the first aspect of the invention.

The present invention also provides apparatus for laying paving blocks in a desired pattern including meansforassembling an array of blocks in the desired pattern from a layer of blocks in standard form (as hereinbefore defined) and depositing the array on the surface to be paved.

In both forms of the apparatus for laying paving blocks, the apparatus may be arranged to move over the surface to be paved. The apparatus may be operable in cycles during which blocks are deposited on the surface to be paved and the apparatus moves over the surface a distance related to the length of blocks deposited.

By way of example, apparatus constructed in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figures land 2 are plan views of arrays of blocks; Figure 3 illustrates the use of such arrays in paving an area; Figures 4 and 5are, respectively, a plan view and side elevation of apparatus for producing arrays of the type shown in Figure 1; Figures 6A and 6B are plan views of, respectively, another array of blocks and two such arrays side-byside; Figure 7illustrates a modification of the apparatus shown in Figures 4 and 5; Figure 8 is a diagrammatic side view of apparatus for laying paving blocks; Figure 9 is a view on the line IX-IX in Figure8;; Figure 10 is similarto Figure 8 but shows the apparatus at another point in its operating cycle; Figure I I 11 a d isa diagrammatic sideview of part of anotherform ofapparatusforlaying paving blocks; Figure 12 is a plan view of anotherform of appar atusforlaying paving blocks; Figures 12and 128 are plan views oftwogroups of blocks produced within the apparatus of Figure 12; Figure 13 is a front elevation of the apparatus shown in Figure 12; Figure 14shows partof Figure 13,with certain components cut away;; Figure 15isa plan view of a componentofthe apparatus of Figure 12, and Figure 16illustrates an alternative method of laying paving stones using the apparatus of Figure 13.

Figure 1 shows an array (or"layer") 1 of paving blocks in which individual, rectangular blocks 3 are arranged in a herringbone pattern. The array 1 is generally rectangular but, because of the herringbone arrangement of the blocks 3, there are half-block spaces 5 at intervals around the edge of the array.

The size of the array is dependent on the size of the individual blocks, which is typically ofthe order of 200mm by 100mm and 80mm thick. In Figure 1,the blocks 3 are shown as being rectangular but they could be shaped as shown in Figure 2, so that each blockinterlocks laterally and longitudinally with the adjacent blocks, or cou Id have any other suitable shape.

Figure 3 illustrates the use of such arrays in paving an area. For the purposes of illustration, the outline of two arrays 7A, 78 has been emphasized although it will be appreciated that, in fact, the outline of individual arrays would not be apparent over the paved area. It can be seen that the arrays 7A, 7B are disposed side-by-side so that the half-block spaces on the adjacent sides of the block are aligned: as a result, blocksize spaces are formed at intervals along the junction of adjacent arrays and, by inserting tie blocks 9 into these spaces, the paved area is completed. The paved area is then indistinguishable from an area which has been paved by laying the blocks 3,9 individually in a herringbone pattern.

Figures 4 and 5 illustrate how arrays of the type shown in Figure 1 can be produced mecnahically. In Figure 4, a partly-formed array 1 can be seen on a table 8, the partly-formed array having a stepped edge 11 atone end. Further blocks (supplied from "standard form" pallets 12, aswill be described below) are being added atthis end to continue the array, the blocks being pushed into position by hydraulically-operated rams arranged in two sets at right angles to each other. One set, comprising ten "travel" rams 13works longitudinally ofthe array and is shown ready to push a line often blocks 15 onto the table 8. The other set, comprising nine "cross" rams 17, works transversely and, as shown, is in the process of pushing a group of nine blocks 19 onto the table 8.

The hydraulic circuitry (not shown) controlling operation of the cross rams 17 ensures that each of the blocks 19 is pushed forwards only until it encounters the stepped edge 11 of the partly-formed array: that is, block 1 9a at one end ofthe group is onlyjust pushed onto the table 8 before it encounters the edge 11 whereas block19iattheotherend is pushed right across the whole width ofthe array.

The rams 17 are now retracted and the rams 13 are actuated to push the blocks 15 onto the table 8 in a similar manner. As before, nine ofthe blocks 15a to 1Siare pushed onto the table 8 until they encounter the stepped edge 11 of the partly-formed array. The tenth block 1 5j, however, has no counterpart in the transverse set of blocks 19 and is pushed onto the table until it is spaced by the width of a blockfrom the block 19i: this results in half-block spaces 14 at intervals along one side ofthe array as the blocks 15 are pushed into position and similar spaces 18 along the other side of the array as the blocks 19 are pushed into position, corresponding to the half-block spaces shown in Figure 1.

When the blocks 15 are in position on the table, the rams 13 are advanced buy a distance equal to 1-1/2 block lengths. This brings the stepped edge 11 of the partiy-formed herringbone array back into position relative to the rams 17, ready to receive the next group of blocks from the standard form pallet 12. As the herringbone array is advanced it moves from the table 8 onto a receiving unit 21.

The rams 13 are then retracted and, in the meantime, another group of blocks has been positioned in frontofthe previously-retracted rams 17, readyto be pushed onto the table 8.

When a complete layer of blocks has been collected on the pallet-receiving unit2l,the unit is lowered by the depth of a layer and is then ready to collectthe next layer from the table 8. As the unit is lowered it leaves the stepped edge 11 of an array already formed on the table 8, to which blocks are added in the manner described above.

It was mentioned above thatthe blocks 15, 19 are supplied from standard form pallets 12, 14. Conven tionally, these are formed from layers each comprising a 5 x 5 array of blocks and so, to supply each ofthe sets of rams 13,17, two standard form pallets are placed side-by-side to give a 10 x 5 array i n each layer.

For each set of rams 13,17, the blocks are supplied from a respective unit which will now be described.

Thetwo supply units are similarand,forclarity, only the supply unit 23 for rams 13 is shown in the drawings. The supply unit 23 contains two pallets of blocks side-by-side, each layer of blocks comprising a 10 x 5 array as just described: a locating frame 27 (which is lowered as blocks are removed) fits overthetop layer to position the blocks correctly. The unit 23 also includes a lift platform 29 and, within the locating frame 27, a ram 31. Operation of the ram 31 is co-ordinated with that of the platform 29 so that, when the lift is in its lowered position (not shown), the ram 31 is actuated to push one row of ten blocks from the top layer 25 onto the platform 29.The lift is then raised, when required, to the position shown in Figures4and 5,to bring the blocks level with the table 8 and in position in front ofthe rams 13.

At the supply unit associated with the rams 17 the procedure is the same but, in this case, an end section ofthe lift platform (indicated at33 in Figure 5) is sprung so that it can be tripped as the platform is raised to discharge the end block and leave only the nine blocks required at the rams 17.

It will be appreciated that, to initiate the production ofthe herringbone arrayonthetable 8, itwill be necessary to establish the stepped edge 11 by placing a number of blocks manually on the table. Oncethis has been done, however, the production of pallets proceeds automatically with the stepped edge of a partly-formed array remaining on the table 8 (as already described) as each complete pallet layer is collected on the unit 21.

The apparatus shown in Figures4 and 5 also provides, automatically, the half-block spaces at the ends ofthe herringbone layers of the pallets as well as those (14, 18) at the sides of the layers. This is achieved by removing two blocks from the table 8 as each layer is being formed, by providing two sprung traps 35 in the table (Figure 5) through which, at an appropriate moment in the formation of a layer,two blocks can be pushed away by descending plungers (not shown). The positions of the sprung traps on the table are indicated in dotted lines in Figure 4.

It will be appreciated that, although Figures4and 5 illustrate the formation of herringbone arrays ofthe size shown in Figure 1, arrays of a larger orsmaller size could be produced by increasing or reducing the numberoframs.13, 17 and increasing or reducing accordingly the number of standard form pallets placed side-by-side in the supply units. Similarly, the number of blocks removed in the supply units (as at 33 in Figure 5) can be altered.

For example, it may in some circumstances be pre operable to produce herringbone arrays ofthe size shown in Figure 6A. This size of array has the advantage, overthatshown in Figure 1,thatthe half-block spaces 5 on the two sides ofthe array are aligned so that it is not necessary to displace adjacent arrays relative to one another in orderto align the half-block spaces. This is illustrated by Figure 6B which shows two ofthe Figure 6A arrays side-by-side, with key blocks 6 inserted in the aligned half-block spaces. To produce the pallet shown in Figure 6A, the apparatus of Figures 4 and 5 would require eighttravel rams 13 and seven cross rams 17.

Alternatively,the machine shown in Figures 4 and 5 could be modified to produce herringbone pallets in a "diagonal" configuration in which the blocks are arranged at 45" to the sides of the pallet. Such a modification is illustrated in Figure 7 from which it can be seen thatthetravel and cross rams 13,17 are as before but the table 8 has been provided with a diagonal extension 8A leading to the receiving unit which has been re-located accordingly. In this arrangement, the rams 13, 3,1 7 work at 45 to the direc- tion of travel ofthe palletsto the receiving unit and, if necessary, a motor can be provided to vibrate the table 8, 8Ato encourage movement of the blocks towards the receiving unit.

Herringbone pallets assembled as described above can be handled and laid in any known manner orthey can be loaded into a machine, shown in Figures 8to 10, from which the pallet layers can be fed and laid end-to-end to yield a continuous paved strip or (when several such strips are laid side-by-side) a complete paved area.

The machine shown in Figures8to 10 has a main body portion comprising a hopper 40, a verticallymovable platform 42 and a chute 44 arranged in series between, and mounted on,two parallel, elongated side members 46 (shown in Figure 9 but mostly omitted from Figures 8 and 10). The side members 46 constitute a sub-frame and are mounted on a pair of longer rails 48 so that they can slide relative thereto as will be described below. Mounted on, and between, the rails 48 (which constitute the main frame ofthe machine) area hopperfloor50 and a bridge 52which passes over the platform 42. One ofthe rails carries a downwardly-extending wall 53 (Figure 9).

Located beneath the platform 42 and carried by the sub-frame 46 is a vertically-movable foot 54 which can be raised and lowered by hydraulic jacks 56. Adjacent the bottom end ofthe chute 44 and also carried by the side members 46 is a set oftransverse rollers 57.

At the ends of the main frame 48, transverse walls 58,60 are provided. The wall 58 at the hopper end of the machine is coupled byapairofdouble-acting rams 62 to the sub-frame 46 and the wall 60 atthe other end of the machine carries a transitwheel assembly 64 including a hydraulic jack 66. Actuation ofthe rams 62 causes the above-mentioned sliding movement ofthe sub-frame 46 relative to the main frame 48 while actuation of the jack 66 raises and lowersthewall 60 relative to the ground and,therewith, the adjacent end ofthe main frame 48.

For use, the platform 42 is loaded with a stack of paving block pallets 68 (the layers of which may be as shown in Figure 1) and the hopper 40 is loaded with sand or other suitable material on which the blocks are to be bedded-down. The machine can then be operated, as will be described below, to deposit a layerofsand and, on top ofthe sand,the arraysof blocks from pallets 68 (the latter being fed outfrom the machine singly and end-to-end).

The machine is powered by a unit 69 comprising a diesel engine driving an hydraulic pumpforoperat ingthevarioushydraulicjacksand rams as described below.

Figure 8 shows the machine at the commencement of a transit stroke. The rams 62 are retracted so that the hopper 40 lies adjacentthe end wall 58 and directly above the hopperfloor 50. The jacks 56 and 66, on the other hand, are extended so thatthe main frame 48 is raised from the ground and the machine is supported on the foot 54 and transit wheel assembly 64 and, finally, the platform 42 is at such a heightthatthe uppermost layer of pallet 68 will just pass beneath the bridge 52.

During the transit stroke, the rams 62 are extended.

The sub-frame 46, being supported on the foot 54, remains stationary and, with it, the hopper 40, the platform 42 and the chute 44. The main frame 48, on the other hand,will be moved to the left as seen in Figure 8 (into the position shown in Figure 10) taking with itthe bridge 52 and the wheel assembly 64.

During this movement, the bottom of the hopper 40 opens and sand from the hopperfalls onto the ground until, at the end ofthe transit stroke, the bottom of the hopper is almost completely open. Atthe sametime, the pallets 68 have moved underthe bridge 52 which is now located at the hopper end of the platform 42 as shown in Figure 10.

The foot 54 is now raised and the jack 66 is retracted,thereby lowering the rails48and bringingthe side wall 53 and end wall 58 onto the ground. Also, the jacks 41 supporting the platform 42 are extended one step, raising the platform byanamountcorres- ponding to the depth of a pallet layer and bringing the machine into the state shown in Figure 10, readyfora laying stroke. During the laying stroke, with the machine resting on the sidewall 53, the end wall 58 of the wheel assembly 64, the rams 62 are retracted moving the sub-frame of the machinetothe left (as seen in Figure 10). During this movement, the bottom ofthe hopper 40 is closed as the latter moves overthe floor 50 leaving a layer of sand on the ground over which an array of paving stones will subsequently be laid. At the same time, the top ofthe bridge 52 engages the uppermost layer of pallet 68 pushes it onto the chute 44.

Attheendofthelaying strokeoftherams62,the bridge 52 lies at the chute end of the platform 42 and the hopper 40 is completely closed again. The foot 54, which is now located above the sand just discharged from the hopper, is lowered and the jack 66 extended, returning the machine to the condition shown in Figure 8 whereupon the cycle is repeated.

The arrays of blocks pushed from the platform 42 slide down the chute 44in succession and underthe rollers 57 onto sand that has been deposited from the hopper during previous cycles of operation, resulting in a continuous paved strip 70 ofthe desired length as the machine moves to the left as seen in Figures 8 and 10. As each array is pushed from the platform 42, the half-block spaces 5 (Figure 1) in its leading end are aligned with the half-block spaces in the trailing end of the preceding array and give rise to spaces into which key blocks must be inserted to complete the paving. These key blocks can be inserted by hand when the arrays have been laid but are, preferably, inserted automatically at the top of the chute 44 at the commencementofthe laying stroke ofthe machine (Figure 10).

It will be appreciated thatthefoot54, when lowered atthe beginning of a transit stroke ofthe machine, rests on sand that has just been deposited by the hopper 40, and therefore has the effect of compacting the sand before the paving blocks are laid on it. To ensure that the compacted sand then has the required thickness, an adjustable blade 72 is provided on the chute side of the foot 54to reduce the level ofthe compacted sand during the next laying stroke of the machine. Adjacent the blade 72 is a series of tines and vanes (indicated at 74) which have the effect, during this next laying stroke, of raking up the surface ofthe reduced layer of compacted sand.This ensures that the blocks, when deposited, will bed properly into the sand and the process is completed by the provision of a vibrator compactor 76 on the machine subframe, which vibrates the deposited blocks into theirfinal level.

Afterthe passage ofthe machine,thevoids remaining between the blocks above the level of the sand bed must be filled, for example with fine drysand.

This can be done by hand or, alternatively, can be carried out by the machine itself.

When one strip of paving has been completed, the machine is repositioned to lay another strip adjacent the first, and soon until the desired area has been paved. Each strip is completed buy a laying stroke of the machine butwith the sand hopper 40 closed and, before the machine is re-positioned, a clamp (not shown) is applied to the bottom of the chute to restrain the pallets already on the chute. The jack 66 is then extended to raise this end ofthe machine on the transit wheel assembly 64 and the machine is towed to its new position by attaching the other end of the machine to a suitable towing vehicle.

Because each operating step ofthe machine corres pondstothelength of a pallet 68 and becausethe layers of a pallet emerge end-to-end from the chute, they are immediately in the correct position relative to the blocks ofthe adjacent strip once the position of the first blocks has been established. When the arrays are as shown in Figure 1,the half-block spaces 5 on adjacent paved strips are aligned and it is necessary to insert key blocks 9 into these spaces by hand to complete the paving. These key blocks may, conveniently, be the blocks that were removed at 33 when the pallets were being assembled (Figures 4 and 5).

It can be seen from Figure 9thatthe strip of sand 43 deposited from the hopper 40 iswiderthan the pallets 68 and that the sand and paving are restrained bythe plate 53 extending downwardly from one of the main frame rails 48. This provides supportforthe edge of the paving and prevents the blocks spreading sideways underthe compaction. It can also be seen from Figure9thattheothermainframerail (which does not have the downwardly-extending plate 53) does not rest on the ground: this enables the sand and paving to be accommodated but may lead to some instability in which case the machine can be provided with wheeled outriders which would run on the previously-laid paving.

It will be appreciated that hopper 40 could be omitted from the machine shown in Figures 8 to 10: the sand bed would then be prepared separately and the machine used only to lay the blocksfrnm pallets 68 onto the prepared bed.

It is also possible to combine the apparatus of Figures 4 and 5 with the machine of Figures 8to 10 so that herringbone pattern paving can be laid in one operation, on site, from standard-form pal lets.

However, the machine of Figures 8 to loins not restricted to laying from herringbone pallets but can, of course, be used to lay arrays in which the blocks are arranged in other patterns (for example, layersfrom the the standard form pallets already referred to). It is also not essential for the arrays to be rectangular.

If the machine of Figures 8to 10is used to lay diagonal configuration arrays of the type shown in Figure 7 then the need for key blocks is avoided because the serrated edges of adjacent arrays will always interlock. It is, however, necessary to raise the chute 44 so that the blocks are discharged at a higher level than those previously-laid, to enable the interlocking to take place.

If the machine is used to lay arrays ofthetype shown in Figure 6A then, by widening the chute 44, several arrays can be fed at once onto the chute side- by-side in the manner illustrated in Figure 6B because (as explained above) there is no need to displace adjacent arrays relative to one another to align the key block spaces. The key blocks can then be inserted as the arrays are being fed onto the chute.

An alternative form of machine which deposits arrays of blocks onto a separately-prepared sand bed is shown diagrammatically in Figure 11.This machine uses an endless conveyor 70 to deposit the arrays 72 onto the sand bed indicated at 74. The arrays 72 are fed, inverted, from a pallet76 onto the upper run of the conveyor and, as the machine moves forward over the prepared bed 74, the conveyor moves around as indicated by the arrow: as each pallet layer reaches the lower run ofthe conveyor, the blocks are deposited (now in the correct orientation) on the prepared sand bed. Preferably, the machine includes a vibrator78 associated with the lower run of the conveyorto assist in settling the blocks in the bed.

Another machine for laying paving blocks in a herringbone pattern is illustrated in Figures 12to 14.

Unlikethemachineshown in Figures8to 10,this machine does not utilize pre-formed arrays of blocks in herringbone pattern but takes blocks directly from standard-form pal lets and forms them into herringbone pattern subassemblieswhich arethen deposited on the area to be paved. The shape of each sub-assembly is that formed by the blocks numbered 1 to 10 in Figures 12, the outline 100 of which has been emphasized for the purposes of illustration.

The sub-assembly 100 is produced in the machine byfirst assembling two groups offive blocks, one group 101 (shown in Figure 12A) comprising the oddnumbered blocks and the other group 102 (shown in Figure 128) comprising the even-numbered blocks.

Each group is assembled, as will be described below, from a respective sta n da rd-fo rm pallet and the two groups are then broughttogetherto producethe sub- assembly 100 which can then be placed in position in the area being paved.

In Figures 12 and 13, the two standard-form pallets from which the two groups of blocks (101 and 102)are produced are shown at 104 and 106. As can be seen in Figure 12, the pallets 104,106 are disposed at right angles to each other and each is provided at one end with a ram 108,110 and atthe other with a discharge trough 112, 114. The discharge troughs are located at differentlevels,thetrough 114beingabovethe trough 1 as shown in Figure 14and it is atthe ends ofthe troughs that the groups 101,102 offive blocks are produced (the group 102 atthe end of upper trough 114 being visible in Figure 12 and the group 101 atthe end of lowertrough 112 being partlyvisible).The groups of five blocks then fall down into a hopper 116 (Figure 14) to produce sub-assemblies of thetype shown at 100 in Figure 1 2which can then be placed in position on the area to be paved as will be described below.

To produce the groups of blocks 101,102 atthe ends of the troughs 112,114, each ram 108,110 is located adjacentthe bottom layer of the adjacent pallet and actuated to push the first row of blocks into the respective trough. Two ofthese blocks must be pushed half a block length furtherthan the other three to fill spaces such as those indicated by the letters Y and Z in thetrough 112 and so produce the required arrangement of blocks at the end of the trough and this is achieved by appropriate shaping ofthe end faces ofthe rams as shown in Figure 12.The pattern of blocks inthetroughs 112,1 14must initially be established by hand but will then remain established and the process will, thereafter, proceed automatically.

From the ends of the troughs, as already mentioned, the groups of five blocks fall down into the hopper 116 from where the sub-assemblies 100 often blocksarefed,insuccession,intoaclamp 118(Figure 15) which, in turn, deposits the sub-assemblies on a prepared sand bed over the area to be paved. The clamp is oftwo-partconstruction 118A, 118B and can be opened and closed by hydraulic rams (not shown) located one at each end 1 19A, 1 1 9B ofthe clamp.

Asthesub-assembliesl00arebeing produced,the machine is moved over the area so that each subassembly is deposited accurately in position relative to the paving that has already been laid. In Figures 12 and 13, the edge ofthe paving that has already been laid is indicated at 120 and the direction of movement ofthe machine is indicated bythe arrow 122. Asubassembly 100 often blocks is contained in the clamp 118 (which is closed) and the machine has been moved (as will be described below) to position the clamp accurately with respect to the edge 120 and the previously-deposited sub-assembly 100. The clamp 118 is then opened and the ten blocks held in the clamp drop into position on the prepared sand bed.At the same time, the ten blocks above them in the hopper 116 also move down until they rest on thetop of those discharged, and are then in position to be gripped by the clamp 1 which is now closed again.

The rams 108,110 are actuated to move more blocks intothetroughs 112,1 14and the machine is then moved to the next position, where the process is repeated.

As the machine advances, a vibrator compactor 124 vibrates the blocks to the required level in the sand bed. The compactor is provided with rollers 124Ato facilitate movement.

The machine itself moves on sets ofwheels 126, 128 and is required to move accurately in predetermined steps parallel to the paving edge 120. To ensurethatthe machine moves parallel to the edge 120, the machine is provided with slides 130, 132 (which engage both the previously-formed edge 120 and the newly-formed edge 1 20A) while the wheels 126,128 are angled (as shown) so that, in the absence ofthe restraining action ofthe slides 130,132, the machine would tend to move away from the paving edge. In combination, however, the slides 130,132 and disposition of the wheels 126, 128 ensure that the machine moves accurately in the required direction.

To regulatethestep-wise movement of the machine, a locator 134 is provided comprising a plurality of hinged units 136 on an endless belt, which engage the serrated edge 120 ofthe previously-laid paving and ensure the accurate positioning of the machine priorto the opening ofthe clamp 118.

The machine is driven byan engine located at 138 and, when it has reached the end of the paving edge 120will be towed backto the beginning of the newlyformed edge 120Ato repeatthe paving process.

The machine shown in Figures 12to 14could be modified, if required, to incorporate a sand hopper from which the sand bed for the blocks would be laid as the machine moves overthe area to be paved. It wouldthen be unnecessary to prepare a sand bed by hand priorto paving.

The machine could also be modified to lay blocks from sizes of pallets other than thefive-by-five size shownat104and106inFigure12.Whateversizeof pallet is employed, it may be more practical to em ploya re-usablesteel stillageforthe pallets rather thanthe conventional wooden stillagesincethefor- merwill be more ableto withstand the action ofthe lower layer of blocks being pushed into the respective trough 112,114 by the associated ram 108,110.

As another alternative, the machine could be simplified substantially and used to deposit only five blocks at a time (for example, the blocks shown in Figure 12A). In this case, the pallet 106 and associated ram 110 and discharge trough 114would not be re quired.

It is a Iso not essential forthe machine to laythe sub-assemblies 100 in the orientation shown in Fi gure 12: it could, instead, laythe sub-assemblies in the orientation shown in Figure 16. In this case, the machinewould move in the direction ofthe arrow 140 andthelocatorl34wouldbearrangedto position the machine by engagement with the blocks indicated by the letter"W". In addition, the orientation ofthe troughs 112,1 14 and the associated rams and hopper would be changed to correspond with that ofthe sub-assembly 100 shown in Figure 16.

Various other modifications of the paving machines described above are possible. For example, the method of moving the machine of Figures 8to 10 is not an essential feature and the machine could, if desired, be modified to run on wheels, and could include a locating arrangementsimilartothat(134) shown in Figures 12 to 14. Similarly, the method of moving the machine of Figures 12 to 14 could be modified, as could the method employed for depositing the sub-assemblies of blocks 100. For example, the clamp 118 could be replaced bye chute similarto that used in the machine of Figures 8 to 10 and/or,the machine could be arranged to work fro the unlaid side ofthe paving.

Claims (47)

1. Apparatus for producing an array of blocks, in which the blocks are arranged in a herringbone pattern, the apparatus comprising a pair of feeding mechanisms arranged at rightanglesto each other, and each operable to supply blocks in staggered formation to a common location to produce the said array.

2. Apparatus as claimed in claim 1, in which each feeding mechanism is arranged to supply blocks from an array of blocks in standard form (as herein before defined).

3. Apparatus as claimed in claim 1 or claim 2, in which each feeding mechanism is operable supply a plurality of blocks simultaneouslyto the common location.

4. Apparatus as claimed in claim 3, in which each feeding mechanism is operable to supply the plurality of blocks from a line of blocks arranged side-by-side and to displace some at least of the blocks relative to the remainder to produce the said staggered formation.

5. Apparatus as claimed in claim 4, in which each feeding mechanism is operable displace each block lengthwise relative to the adjacent block by a distance equal to half the length of a block.

6. Apparatus as claimed in anyoneofclaims3to 5, in which each feeding mechanism comprises a respective ram for each of the plurality of blocks, the plurality of rams being operable simultaneously to move the plurality of blocks lengthwise to the said common location.

7. Apparatus as claimed in claim 6, in which each ram is arranged to move furtherthan the adjacent ram by a distance equal to half the length of a block.

8. Apparatus as claimed in claim 7, in which the feeding mechanisms are operable alternately, each mechanism being arranged to position a plurality of blocks adjacent a plurality of blocks already positioned at the said co mmon location bytheotherfeed- ing mechanism.

9. Apparatus as claimed in any one ofthe preceding claims, including receiving means to which blocks, arranged in a herring bone pattern, are fed from the said common location.

10. Apparatus as claimed in claim 9, in which the receiving means is arranged to be fed with blocks continuously.

11. Apparatus as claimed in claim 10, in which the receiving means is operable to divide the blocks received into a plurality of pellets.

12. Apparatus as claimed in anyoneofclaims9to 11, in which blocks are fed to the receiving means in a direction at 45" to the longitudinal axes of the blocks.

13. Apparatusasclaimed in anyoneofclaims8to 11, in which blocks are fed to the receiving means in a direction parallel to the longitudinal axes of some of the blocks and at right angles to the longitudinal axes ofthe remaining blocks.

14. Apparatus as claimed in claim 12, including means for removing selected blocks from the standardform array.

15. Apparatus as claimed in claim 13, including means for removing selected blocks from the herringbone pattern array.

16. Apparatus as claimed in claim 4, in which each feeding mechanism is operable to displace alternate blocks lengthwise reletivetothe remaining blocks by a distance equal to half the length of a block.

17. Apparatus as claimed in any one of claims 3,4 and 16, in which each feeding mechanism comprises a single ram operable to move the plurality of blocks lengthwise to the said common location.

18. Apparatus as claimed in claim 15, inwhichthe ram is shaped to displace alternate blocks lengthwise relative to the remaining blocks by a distance equal to half the length of a block.

19. Apparatus as claimed in claim 16 in which the feeding mechanisms are operable simultaneouslyto supply respective lines of staggered blocks which are broughttogethertoform en array of blocks in her- ringbone pattern.

20. Apparatus for laying paving blocks, including meansforforming the blocks into a continuous strip and depositing the strip on the surface to be paved.

21. Apparatus as claimed in claim 20, in which the forming means is operable to position arrays of blocks end-to-end to form a continuous strip.

22. Apparatus as claimed in claim 20 or claim 21, the apparatus being movable over the surface to be paved to deposit the said continuous strip.

23. Apparatus as claimed in claim 22 when appen- dantto claim 2l,the apparatus being operable in cycles during each of which another array is added to the continuous strip of blocks and the apparatus moves, over the surface to be paved, a distance equal to the length of an array.

24. Apparatus as claimed in claim 23, in which the apparatus is movable in steps during each ofwhich first one part of the apparatus moves relative to the remainder ofthe apparatus and the surface to be paved, and then the second part ofthe apparatus moves relative to the said one part and the surface to be paved.

25. Apparatus as claimed in any one of claims 21 to 24, including a discharge arrangement from which the said continuous strip is deposited on the surface to be paved, and means forfeeding arrays of block in succession to the input end of the discharge arrangement.

26. Apparatus as claimed in any one of claims 20 to 25, including means for embedding the deposited strip in thesurfaceto be paved.

27. Apparatus as claimed in any one of claims 20 to 26, including meansfordepositing on the surface to be paved, prior to the blocks, a layer of material into which the blocks are to be embedded.

28. Apparatus as claimed in claim 27 including means for levelling and/or compacting and/or raking the layer of material before the blocks are deposited thereon.

29. Apparatus as claimed in any one of the pre- ceding claims, including meansforassemblingthe blocks into arrays from which the said continuous strip is formed.

30. Apparatus as claimed in claim 29, in which the means for assembling the blocks into arrays is operable to arrange the blocks in a herringbone pattern.

31. Apparatus as claimed in claim 30, in which the assembling means comprises apparatus as claimed in any one of claims 1 to 19.

32. Apparatusfor laying paving blocks in a desired pattern including means for assembling a subassembly of blocks in the desired pattern from an array of blocks in standard form (as hereinbefore defined) and depositing the sub-assembly on the surface to be paved.

33. Apparatus as claimed in claim 32, in which the assembling means comprises apparatus as claimed in any one of claims 16 to 19.

34. Apparatus as claimed in claim 32 or claim 33, the apparatus being arranged to move in steps over the surface to be paved, each step being equal to the length of a su b-assembly of blocks.

35. Apparatus as claimed in claim 34, theepparatus being operable in cycles during each ofwhich: a sub-assembly of blocks is formed; a sub-assembly of blocks is deposited on the surface to be paved, and the apparatus is moved one step over the surface to be paved.

36. Apparatus as claimed in claim 34 or claim 35, including means engageable with previously-laid paving to constrain the apparatus to move parallel to the edge of that paving and in position to deposit a sub-assembly adjacent the said edge.

37. Apparatus as claimed in claim 20 or claim 34, including means for locating the apparatus in a desired position relative to blocks already deposited on the surface to be paved.

38. Apparatus as claimed in claimed 37, in which the said locating means is engageable with the blocks already deposited on the surface to be paved.

39. A method of paving a surface including the steps offorming, from an array of blocks in standard form (as hereinbefore defined), arrays of blocks in which the blocks are arranged in herringbone pattern and depositing the herringbone arrays end-to-end on the surface.

40. A method as claimed in claim 39, including the step offorming the herringbone arrays into a continuous strip before they are deposited on the surface.

41. A method as claimed in claim 40, in which the longitudinal axes of some of the blocks in the herringbone arrays lie parallel to the axes of the arrays, the method including the step of aligning key block spaces, around the periphery of each herringbone array, with those in a previously-deposited array.

42. A method as claimed in claim 41, including the step of inserting blocks into the aligned key block spaces.

43. A method as claimed in claim 39, in which each array is deposited as a unit adjacent a previously-deposited array.

44. Amethod as claimed in any one of claims 39 to 43, substantially as hereinbefore described.

45. Apparatusforproducing an arrayofblocks, the apparatus being substantially as described herein with reference to, and as shown in Figures 4 and 5 of the accompanying drawings.

46. Apparatus as claimed in claim 1, substantially as described herein with reference to, and as shown in, Figures 12 to 14 ofthe accompanying drawings.

47. Apparatus for laying paving blocks,substan- tially as described herein with reference to, and as shown in, Figures 8 to 10 or Figure 1 1 or Figures 12to 14 of the accompanying drawings.