Title: Method and apparatus for mechanical paving.
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The invention relates to a method of mechanically laying pavin or the like, in which bricks are taken simultaneously from a packet of bricks, in batches of at least one group at a time, and placed in a desired pattern as they are moved to a sub-grade. 5 In a prior method, which is described, for example, in Dutch patent application 69,03959, the bricks are transferred from the packet to a conveyor, on which they may undergo a shift- or rotation, after which, at the delivery end of the conveyor, they are moved to an auxiliary template and then, by way of a subjacent template onto the sub-grade. 10 This method is very cumbersome and the apparatus required for carrying it out is consequently very complicated, requires many parts and is expensive. Moreover the apparatus cannot easily be adapted to different widths of roads.
It is an object of the present invention to remove the dis- 15 advantages referred to.
For this purpose a method of a kind mentioned above is characterized in that the bricks of the group of bricks after being re¬ moved from the packet: are first spaced a small distance apart, then moved into the desired basic pattern, thereafter moved towards each other again 20 and subsequently put in their place on the sub--grade.
In this method, two or more rows of bricks may be removed at a time from the upper layer of a stack of bricks positioned in a first pattern, by engaging the bricks of these rows each individually and simultaneously, then putting them into the desired second pattern and 25 placing them all at the same time directly onto the sub-grade in said ~f ■ second pattern.
The invention further relates to apparatus for mechanically laying a pavement or the like, comprising a carriage equipped with suction-lift means comprising a frame equipped with at least one suction 30 cup which is connected with a vacuum source. According to the invention the apparatus is characterized in that the frame is equipped with a plurality of suction cups corresponding with the number of bricks to be
placed simultaneously, which suction cups are movable in longitudinal and transverse direction and also in a rotary sense in mutually coupled f shion.
It is noted thatDutch patent 147,811 discloses a method and apparatus for placing paving bricks, in groups, onto a road surface, in which the bricks are first put, by hand, in a herringbone pattern on a conveyor which is movable in the longitudinal direction of the road, and then, by means of a suction-lift device, placed in groups into their place on the sub-grade. Although with this apparatus the bricks are placed in a herringbone pattern by hand, nevertheless a very complicated machine has come about, which is not easily adapted to different widths of roads. Another disadvantage of this prior apparatus is that it can hardly be used for paving squares and bends in roads.
For the sake of completeness it is pointed out that Dutch patent 133,818 discloses a travelling paver including a movable jib the free end of which carries a suction-lift device. That apparatus, however, is more particularlyintended for placing tiles one-by-one at joint dis¬ tances apart.
Furthermore, Dutch patent application 68,16198 discloses a method and apparatus in which from a number of piled up rows of bricks each time the bottom row is deposited onto a sub-grade in a pattern cor¬ responding with the desired bond and then pressed against a row of bricks already placed. It is true that this concerns a very simple method and apparatus, but the number of bricks laid per time-unit is low, too." More- over the apparatus is subject to considerablewear and tear.
In a further elaboration of the invention each suction cup is secured to a hollow guide bush or a suction pipe extending through it, the bushes are accommodated, in groups, for sliding movement in relative¬ ly movable guides, each guide bush is fixed to a guide plate, and the guide plates which are fixed to one and the same guide are interconnected by two slotted coupling elements disposed diametrically relatively to the guide bush. In that embodiment the guides may each, with the help of sliding bearings, be connected with shafts disposed on opposite sides of the frame, and cylinder-and-piston combinations mounted between the guides. For the positioning of the guide bushes one of the guide bushes of each set cooperating with one guide may be connected to the free end
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of the piston rod so as to be restrained from rotation and the guide plate located opposite the piston rod end may be engaged by a spring, on the one hand, and by a coupling plate, on the other, the other end of eac of which is fixed to the frame. Furthermore the frame may be provided with a vacuum tank, whic on the one hand, can be connected with a vacuum source and, on the other hand, is provided with a number of connecting nipples corresponding to the number of hollow guide bushes, which connecting nipples are each fixed, by means of vacuum tubes, to a hollow guide bush or a suction pipe extending through it. It is thus achieved that the apparatus operates correctly even in case one or more bricks are missing by whatever cause. For convenience each guide may consist of two pairs of strips in spaced superimposed relationship, with the guide plates being each attached between the two lower and upper strips. To elucidate the invention one embodiment of a paving machine according to the invention will be described with reference to the accompanying drawings. In said drawings,
Fig. 1 shows the upper layer of a stack of bricks in the suc¬ cessive positions during its placing in herringbone pattern; Fig. 2 shows a view similar to Fig. 1, during the placing in shifted pattern of the upper layer of a stack of bricks;
Fig. 3 shows a top view of part of a carriage with suction- lift device according to the invention, for placing a plurality of bricks, in groups, in herringbone pattern; Fig. 4 shows a side view of the apparatus of Fig. 3;
Fig. 5 shows a cross-section of a suction-lift device used on the apparatus of Fig. 3 and 4;
Fig. 6 shows a top view of the suction-lift device of Fig. 5, with the parts on the left in a position before placing the bricks in herringbone pattern and, on the right, after placing the bricks in herringbone pattern and
Fig. 7 shows a side view of the apparatus shown in Fig. 6. According to Fig. 1 , which shows a top view of a stack of bricks, bricks 1 are supplied in a number of rows, in this example four, of eleven bricks each. From the closed pattern shown in Fig. la the rows are spaced a small distance apart (Fig. lb) . As Fig. lc shows, the bricks
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of each row are then spaced a small distance apart, at the same time the bricks of adjoining rows are put in an off-set position relative to each other. Then all the bricks are turned, that is to say: each of the succes¬ sive rows alternately in opposite direction (Fig. Id) . Finally the rows of bricks are moved towards each other which leads to the herringbone pattern shown in Fig. le.
Figures 2a, 2b, 2c and 2d successively show the positions of the bricks when moved from the closed pattern in which they are supplied to the off-set pattern shown in Fig. 2d. For mechanically laying paving the apparatus shown in Figures
3-7 may be used. In Figures 3 and 4, in addition, jib 2 of a travelling crane 3 is shown. These two figures show that from the stack of bricks 4, supplied, by means of a suction-lift device 5 carried by the free end of jib 2, the upper layer can be taken from the stack of bricks 4. After placing the bricks in the correct pattern these can be placed in the pavement simultaneously.
The suction—lift device 5 will now be described in more detail with reference to Figures 5, 6 and 7. These show that the suction-lift device is provided with a frame 6. in this frame two parallel shafts are secured one above the other at both sides.
As stated before, each brick is engaged separately by a suc¬ tion cup 8. Each of the suction cups is secured to a suction pipe 9 ex¬ tending through a guide bush 10 which in turn is secured to a guide plate 11. The drawing shows that the guide bushes are mounted in a guide con- sisting of four spaced strips 12, 13, 14 and 15 for cooperation with the suction cups for encaging a single row of bricks..The ends"of strips 12-15 are each attached, by means of couplings, to sliding bearings'17 mounted on shaft 7.
Guide bushes 10 are each positioned for sliding movement between strips 12, 14, on the one hand, and strips 13, 15, on the other, while guide plates 11, fixed to guide bushes 10, are positioned for sliding movement between strips 12, 13, on the one hand, and strips 14, 15, on the other.
The adjoining guide plates 11, fixed to guide bushes coopera- ting with one guide are each interconnected by two pairs of coupling strips 18. The coupling strips, each engaging with each guide plate diametrically opposite the guide bush, are at one end equipped with a
slot 19.
As Figures 6 and 7 show, the coupling plate 11 located on one end of a row is secured to coupling 16 by a spring 20, on the one hand, and by a coupling rod 21, on the other. For realizing the desired movement pattern, a piston-and-cyUn der assembly 22 is used. The free end of piston rod 23 thereof is, by • means of a strip 24, fixed to one of the guide bushes 10 cooperating with one guide 12-15. For the spacing apart of guides 12-15 during the execu¬ tion of the desired movement pattern these are each interconnected by piston-and-cyUnder combinations 25 on the position of couplings 16.
Figures 5 and 7 show a vacuum tank 26, arranged within frame 6 of the suction-lift device, which tank is provided with a number of connecting nipples 27 corresponding with the number of guide plates. Connecting nipples 27 are each, by means of vacuum tubes 28, connected with a suction pipe 9. Although not shown in the drawing, it will be clear that the vacuum tank may be connected with a vacuum pump fixed to carriage 3, by means of a tube.
Further the drawing shows that the top of the frame is provided with a connecting flange 29 for attachment to the movable jib 2 of crane 3. In this flange a servo motor not shown may be built in for selectively turning the frame of the suction-lift device, so that the position there¬ of may be adapted to the position of the stack of bricks from which the upper layer or part thereof is to be removed and for placing the same on the exact position in the pavement pattern. Within the scope of the inventive idea a large number of changes and additions are possible, of course.
Thus the construction of the guides and the mutual connection of the guide plate could easily be changed. Further, in the frame of the suction-lift device means, such as clamping means could be provide to ensure that the rows of bricks to be engaged are held properly in con¬ tact with each other, so that each suction cup engage with the subjacent bricks approximately in the middle. Furthermore, the apparatus lends • itself particularly well to placing smaller zones than the four or eleven bricks placed in this case, namely by covering some of the suction cups or closing them in some other way. Also the suction cup located in a ful¬ ly enclosed corner can be closed, and the remaining brick, which is apt
to give trouble during mechanical placing, may be manually put in its place afterwards.