METHOD AND APPARATUS FOR MANUFACTURING BUILDING BLOCKS CONTAINING HOLES

Abstract: The block compound is supplied to a measuring box (13) and a mould (21A, 21B) is engaged therewith. The mould is closed from below while inserting a mould core (22) therein, and a portion of the block compound in the measuring box is discharged therefrom into the mould. The mould core is vibrated and the vibration is transmitted to the mould and the measuring box.

Description: METHOD AND APPARATUS FOR MANUFACTURING BUILDING BLOCKS CONTAINING HOLES The invention relates to a method for manufacturing building blocks containing holes, wherein a plastic com¬ pound with cement as a binder is vibrated in a mould. It has been developed particularly for manufacturing building blocks containing holes of cement-stabi 1 i zed light clinker, i.e. burnt expanded clay, or similar porous filler, but it is applicable also to the manu¬ facture of other types of building blocks containing holes, e.g. such blocks made of concrete. According to the German laid-open specification 2,325,165, it is previously known to vibrate the mould core during the manufacture of building blocks by this process in order to obtain a satisfactory working of the constituents of the compound from which the build¬ ing block is manufactured so as to produce a building block of homogeneous quality. The primary object of the invention is to facilitate the manufacture of building blocks of the type referred to and to lower the manufacturing costs thereof while obtaining a high quality of the building blocks as to the accuracy of size as well as the strength and homogeneity thereof. In order to achieve this object there is provided according to the invention a method for manufacturing building blocks containing holes, wherein the plastic compound having cement as a binder is supplied to a measuring box in an amount which is substantially greater than that corresponding to the volume of the block, the block compound is allowed to flow from above into a mould from the r easuring box, a mould core for forming the holes of the block extending from below into the mould, and the mould core is with- drawn from the mould after the block having been formed therein, characterized in that the mould core is vibrated and that the vibration is transmitted to the mould as well as the measuring box. The invention also relates to an apparatus for manufacturing building blocks containing holes, of a plastic compound having cement as a binder by working the method according to the invention, said apparatus comprising at least one mould open at the top thereof, a mould core which can be inserted into the mould from below, a measuring box located above the mould and having a volume which is substantially greater than the volume of the block to be formed in the mould, and means for supplying the plastic compound from above to the measuring box, characterized in that means are connected to the mould core for vibrating the core and that the mould core and the measuring box can be engaged with the mould from below and from above, respectively, while maintaining the mould core, the mould and the measuring box in vibration-transmitting re! ationship . In order to illustrate the invention this will be described in more detail below reference being made to the accompanying drawings wherein FIG. 1 is a side view of an apparatus for work ng the method according to the invention; FIG. 2 is a front view, partly a vertical cross- -sectional view, of the apparatus; FIG. 3 is an enlarged fragmentary side view of a slide forming part of the apparatus; FIG. 4 is an enlarged vertical cross-sectional view of the mould and the associated mould core; FIG. 5 is a plan view of the mould core; FIG. 6 is a plan view of the mould; and FIG. 7 is an end view of a section of the bottom OMPI of the mould. The apparatus for working the method according to the invention, disclosed in FIGS. 1 and 2 in the draw¬ ings, comprises an upright apparatus stand 10. A hopper 11 is provided in the upper portion of the stand to receive a supply of the plastic compound of which the building block is to be manufactured such as a wet mixture of Portland cement and light clinker (porous burnt clay). The hopper is funnel-shaped and has at the bottom thereof a discharge opening provided with a pivoted closure slide 12 which can be operated manually or by servo means in a suitable way. Below the hopper 11 a measuring box 13 open at the top connects to the discharge opening of the hopper, said measuring box being supported by a slide 14 which is guided for vertical displacement in the stand 10. This slide can be reciprocated between an upper position shown in solid lines in FIG. 1 in the drawings, and a lower position shown in dot and dash lines in FIG. 1 in the drawings, by means of a double-acting hydraulic ram, a screw spindle or other operating means. The connection between the measuring box 13 and the slide 14 preferably comprises anti -vi brati on means of conventional type although such means have not been shown in the drawings. Plastic compound from which the building blocks are to be manufactured is filled directly into the measuring box 13 through the open upper end thereof from the hopper 11 while the discharge from said measuring box is controlled by means of a closure slide 15 at the lower end of the measuring box. This slide is connected to a double-acting hydraulic ram 16 supported by a bracket 17 on the measuring box ' 13, and the slide can be displaced by means of said ram between the closed position shown and an opened position in which the lower end of the measuring box 13 is fully open. The slide 15 is guided for displacement in a frame 18 at the lower end of the measuring box. A U-formed member 19 is rotatably mounted in the apparatus stand 10 and can be rotated by means of a hydraulic engine 20 connected therewith, between two positions spaced 180°. Each limb of the member 19 supports a mould 21A and 21B, respectively, these two moulds being floatingly mounted in the member 19 by anti-vibration means, although such mounting is not shown in detail in the drawings. In the upper position of the mould, mould 21A being shown in this position in FIGS. 1 and 2 in the drawings, a mould core 22 can be inserted into the mould from below. This core is supported by anti-vibration means 23 on a bracket 24 projecting from a slide 25 guided for vertical dis¬ placement in the apparatus stand 10 between a lower position shown by solid lines in FIG. 1 , and an upper position shown by dot and dash lines in FIG. 1 in the drawings. Two or more electrical vibrators 26 of the unbalanced type are mounted on the core 22 in order to provide vibration of the core. The mould should be provided with a l d n the upper position thereof, and for this purpose there is provided on the apparatus stand 10 a bracket 27 projecting from the stand, which has a magazine 28 receiving a number of stacked boards 29 the lowermost board of the stack being displaceable on a runway 30 on the bracket 27 by means not shown such as a double- -acting hydraulic ram, from the lowermost position in the stack of boards 29 to a position on top of the mould 21A where the board forms a lid and is shown at 29A. On the mould or on the member 29 supporting the moulds there should be provided means such as hydraulically operated hooks for locking the lid 29A in position on the mould 21A but such means which can easily be provided by the man skilled " in the art have not been shown in the drawings. •A lifting fork 31 is provided in the lower portion of the apparatus stand 10 and is guided for vertical displacement in the stand between the lower position thereof shown by solid lines, and an upper position shown by dot and dash lines in FIG. 1 in the drawings, the lifting fork when in the upper position thereof, being engaged with the lid 29B on the mould 21 B shown in the lower position thereof. As will be understood the lid has been located on the mould 21B and locked to this mould when it was in the upper position there¬ of, occupied by the mould 21A in FIGS. 1 and 2 in the drawings. The lifting fork 31 is inserted in the lower position thereof between the rollers 32 of a roller conveyor provided at the base of the stand, and then is located below the horizontal plane tangential to the rollers 32 at the top thereof. The slide 25 and the lifting fork 31 can be provided with means of the same type as provided for the slide 14 in order to displace the slide 25 and the lifting fork 31 vertically up and down in the apparatus stand 10. Referring to FIGS. 4 to 7 in the drawings, these figures disclose in more detail how the moulds 21A and 21B are constructed for co-operation with the mould core 22. In the present case each mould is constructed for moulding four building blocks and comprises a rectangular frame which is open at top and bottom and is provided with partition walls 34 parallel to the shorter sides of the frame. On the outside of the frame 33 there are provided two circumferential flanges 35 and 36 project¬ ing perpend cularly from the frame and spaced one above the other as shown in FIG. 4. The frame 33 can be supported by the member 19 at these flanges 35 by anti- -vibration means. In each section of the frame 33, i.e. in each cavity for an individual building block, there is provided a bottom 37 havi g openings 38 the form and pattern of which correspond to the form and pattern of the holes of the building block to be manufactured in the apparatus. The bottom 37 fits inside the mould cavity to be displaceable transversely of the plane thereof inside the mould cavity. On the lower side thereof each bottom 37 has two longitudinal rails 39 interconnected by a transverse rail 40 at each end of the bottom 37 the rail 40 being located between the lower. side of the bottom 37 inwardly of or flush with the edge. along the shorter side of the bottom, and a projecting tongue 39' formed by each rail 39. Between the upper side of the bottom and the upper edge of the tongue 39' there is accordingly provided a space equal to the combination of the thick¬ ness of the bottom and the height of the rail 40. There¬ fore, the bottom can be pushed into the mould cavity formed by the frame 33 and the partition walls 34 a distance corresponding to said space. Rails 41 extending along the longer- sides of the frame 33 are connected to the tongues 39' formed by the rails 39, said rails 41 being connected to bars 42 two for each bottom at each end thereof, which are dis- placeably guided in the two flanges 35 and 36 and are connected at the upper ends thereof to rails 43 corresponding to rails 41 and thus extending along the longer sides of the frame 33. Thus, when the mould is in the position according to FIG. 4, the bottoms 37 of the several sections of the mould are suspended by the bars 42 which are supported at the rails 43 on the upper side of the flange 1 35. In this position, the bottom is located inside the mould cavity and the lower side there- of is substantially flush with the lower edge of the fram OMPI Wl O 33. If the frame is turned up and down from the position shown in FIG. 4 the bottom 37 can slide a short distance into the mould cavity until the tongues 39' engage the edge of the frame 33, which is now the upper edge. A good point about the displacement thus provided will be explained in more detail in connection with the description of the method accord¬ ing to the invention when worked in the apparatus shown and described. The mould core 22 is shown in FIGS. 4 and 5 and comprises a panel 44 supporting a number of upwardly projecting core bodies 45 of a form corresponding to the form of the holes in the building block to be manufactured and arranged in the same pattern as the holes of the block. The core bodies 45 of the core can be inserted into the mould cavity through the openings 38 of the bottom 37. In order to limit the movement into the mould cavi ty, standards 46 having guide pins 47 at the ends thereof are provided on the panel 44, these guide pins 47 penetrating into openings in the flange 36 on the frame 33 when the mould core is being displaced into the mould cavity. The standards 46 will engage the lower side of the flange 36 to form abutments limiting the movement of the mould core into the mould cavity. When the mould core is in the position defined by the standards 46 the upper ends of the core bodies 45 can be located below the upper edge of the frame 33 if the building blocks are to be formed with bottom holes, as shown in FIG. 4 in the drawings. The mould and the mould core are of course constructed with due considerat on of the technique commonly applied when constructing moulds and thus the necessary relief is provided in the mould as well as on the mould core. The method according to the invention can be per- formed in the following manner by using the apparatus shown and described: The measuring box 13 is supplied with plastic com¬ pound for the building blocks to be manufactured from the hopper 11 the compound being allowed to flow by gravity from the hopper into the measuring box 13 when the closure slide 12 has been opened. It is of course presupposed that the closure slide 15 is in the closed position shown. The measuring box is filled completely, and it will be seen that this box has a volume which is substantially greater than the volume corresponding to the four building blocks manufactured in a mould, and preferably the volume of the measuring box is four times as large as the volume of the four building blocks. Now, it is initially assumed that the measuring box 13 is filled completely with plastic compound and it is also assumed that the moulds 21A and 21B are located in the upper and lower positions, respectively, shown in FIGS. 1 and 2 in the drawings. Finally, it is also assumed that no lid 29A has been located on the upper mould 21A so far. The filled measuring box 13 is dis¬ placed to the lower position thereof by displacement of the slide 14 downwardly in the apparatus stand 10 and then the rails 43 of the mould 2 A will engage the frame 18 of the measuring box. This frame should be provided with a resilient sealing ring, not shown, which will engage the upper edge of the frame 33 and will seal between the frame 18 and the frame 33, the engagement of the rails 43 with the frame 18 defining the extent of compression of the sealing ring between the measuring box and the mould. The next step of the method is that the slide 25 is displaced to the upper end position thereof, the mould cores 22 being raised and inserted into the mould 2TA. The mould bodies 45 then pass through the openings 38 O.MP1 of the bottoms 37 of the mould and eventually the guiding pins 47 penetrate into the openings of the flanges 36 and the standards 46 engage the lower side of the flanges36. Thus, the mould 21 A is clamped between the measuring box 13 and the mould core 22. The measuring box, the mould and the mould core being in this position there is provided a vibration trans¬ mitting connection from the mould core 22 provided with the vibrators 26, to the mould 21 A through the standards 46 and the flange 36 and from the mould to the measuring box 13 through the bars 42 and the rails 43 engaging the frame 18. Therefore, when the vibrators 26 are started in the next step of the method not only the mould core 22 but also the mould 21A and the measuring box 13 ll vibrate. No other parts of the apparatus will vibrate, however, because said three vibrating elements all are connected to the supporting parts of the apparatus stand, i.e. the slide 14, the member 19, and the slide 25, by anti -vibration means. When the closure slide 15 is withdrawn to the opened position thereof which can take place before or after the vibrators 26 having been started, the mould 21A is filled with plastic compound from the measuring box 13 and such compound will be vibrated in the mould to the extent which is necessary in order to obtain a homo¬ geneous filling of the mould. However, at the same time compound remaining in the measuring box 13 is vibrated, which provides a more intense working of the compound and a more thorough wetting of the cement binder in the compound. The compound supplied to the mould thus has been vibrated several times, in the present case four times, before it is filled into- . the mould 21 A after having been thoroughly worked. It is necessary to supply to the measuring box 13 after each filling of the mould only the amount of compound corresponding to one filling of the mould. When the mould 21A has been filled and vibrated as is necessary, the slide 15 is returned to the closed position thereof. An interesting detail in connection therewith will be explained with reference to FIG. 3. As will be seen from FIG. 3, the slide 15 provides a sharp edge 48 having a bevelled surface 49 at the - lower side thereof and a bevelled surface 50 at the upper side thereof. The slide 15 is guided in the frame 18 and thereby is prevented from deviating from the rectilinear path thereof, and therefore, when it cuts into the compound and separates the portion there¬ of contained in the mould, from the portion thereof remaining in the measuring box the sharp edge will provide a pressure on the compound in the mould at the bevelled surface 49 so that the material will be compressed, which provides a thorough filling of the mould in its entirety. In FIG. 3 there is indicated by an arrow how. the material is compressed under the slide 15 at the sharp edge 48 thereof when the slide moves from the right to the left during the closure thereof. Now, the measuring box 13 and the mould co re 22 are separated from the mould 21A by displacing these movable elements upwards and downwards, respectively, by displacement of the slide 14 upwards and the slide 25 downwards to the positions shown by solid lines. The board 29A is displaced from the magazine 28 and is locat as a lid on top of the mould 21A and is locked to the mould in the manner previously ind cated. The member 19 is turned around 180° by means of the hydraulic engine 20 so that the filled mould 21A will arrive at the lower position where the mould 218 is located in FIGS. 1 and 2 in the drawings. If it is assumed that the mould 21 B has been filled in the manner described above and has been provided with a lid 29B, the next step of the method is that the lifting fork 31 is raised to engage the lid 29B. This lid is unlocked from the mould 21B, and when the lifting fork 31 later on is lowered also the lid 29B with the moulded block standing thereon is lowered said block sliding from the mould 21 B . Sliding of the block from the mould can be facilitated by means of an impulse vibrator mounted to the member 19. When the lifting fork 31 is lowered the bottom 37 will move a little nto the mould cavity and the weight thereof will assist in pressing the block out of the mould, the bottom simultaneously pressing the lid 29B against the lifting fork 31 over the bars 42 and the rails 43, which facilitates the removal of the block from the mould. When the lifting fork 31 is in the lower position shown by solid lines the lid 29B with the building block or more exactly the four building blocks standing thereon is located on the rollers 32 of the roller conveyor and the blocks can now be removed to a position where they are to be dried, by this roller conveyor. The mould 21A can of course be filled and vibrated in the upper position thereof at the same time as the . blocks previously formed are being removed from the mould 21B at the lower position thereof, and in this connection it should be noted that the heavy vibrations imparted to the mould 21 A will not be propagated over the member 19 to the mould 21B because the moulds are sus¬ pended by anti -vi brati on means. However, as mentioned above, a lighter vibration can be imparted to the mould 21 B in the lower position thereof in order to facilitate the removal of the blocks from the mould. In the apparatus described the displacement of the moulds from the filling position to the emptying position takes place inside the apparatus proper by means forming part of the apparatus, i.e. the member 19 driven by the hydraulic engine 20. However, it is also possible to arrange the moulds for movement in paths extending through the apparatus and to turn around the moulds outside the apparatus by using means already available for this purpose. An apparatus as that described is, however, advantageous because the manufacture of the blocks can take place in a compact and self-contained unit. In a modification of the apparatus described for manufacturing composite building blocks containing holes therein, i.e. blocks of sandwich construction, partition walls are provided in the measuring box 13, which can be displaced downwards into the mould 29A or 29B when engaged with the measuring box. Two partition walls in that case are provided for each partition wall 34 in the mould. They, extend in parallel with the partition wall 34 and are spaced one on each side of the partition wall 34. Two further partition walls are provided one spaced from each of the shorter end walls of the frame 33 in parallel therewith. Thus, these displaceable partition walls provided in the measuring box 13 when positioned in the mould engaged with the measuring box define a mould cavity at each partition wall 34 at each side there of and at each shorter side wall of the frame 33. Two or more hoppers in that case are provided in order to supply a material of a different type to said cavities than that supplied to the rest of the mould cavity. Thus, a more dense material such as concrete or cement-stabilized light clinker can be used for the surface layer along the longitudinal . sides of the block while a high-insulating material such as cement-stabilized light clinker material or plastics material can be used for the body of the block. O P

Claims: CLAIMS 1. A method for manufacturing building blocks containing holes, wherein the plastic compound having cement as a binder is supplied to a measuring box (13) in an amount which is substantially greater than that corresponding to the volume of the block, the block compound is allowed to flow from above into a mould (2 A) from the measuring box (13), a mould core (22) for forming the holes of the block extending from below into the mould, and the mould core is withdrawn from the mould after the block having been formed therein, c h a r a c t e r i z e d in that the mould core (22) is vibrated and that the vibration is transmitted to the mould (21A) as well as the measuring box (13). 2. A method as claimed in claim 1 , c h a r a c - t e r i z e d in that the compound in the measuring box (13) is vibrated several times, i.e. every time the mould (21A) is being filled, before it is supplied to the mould. 3. An apparatus for manufacturing building blocks containing holes, of a plastic compound having cement as a binder by working the method according to claim 1 or 2 comprising at least one mould (21A) open at the top thereof, a mould core (22) which can be inserted into the mould from below, a measuring box (13) located above the mould (21A) and having a volume which is substantially greater than the volume of the block to be formed in the mould, and means (11, 12) for supplying the plastic compound from above to the measuring box, c h a r a c t e r i z e d in that means (26) are connected to the mould core (22) for vibrating the core and that the mould core and the ' measuri ng box can be engaged with the mould from below and from above, respecti-vely, while maintaining the mould core, the mould and the measuring box in vibration-transmitting rel ationshi p . 4. An apparatus as claimed in claim 3', c h a r a c t e r i z e d in that the mould (2 A) is floatingly mounted in the apparatus. 5. An apparatus as claimed in claim 4, c h a r a c t e r i z e d in that the mould (21A), the mould core (22) and the measuring box (13) are vibrational ly insulated from the stand (10) of the apparatus. 6. An apparatus as claimed in any of claims 3 to 5, c h a r a c t e r i z e d in that the means for supplying the plastic compound comprises a hopper (11, 12) above the measuring box (13) for discharging the compound into the measuring box and that the measuring box (13) and the mould core (22) are mounted for displacement towards and away from the mould (21A) at the upper and lower sides thereof, respectively. 7. An apparatus as claimed in any of claims 3 to 6, c h a a c t e r i z e d in that means are pro- vided for locating and retaining a lid (29A) on the mould ( 21A) and for subsequent turning of the mould. 8. An apparatus as claimed in claim 7, c h a r a c t e r i z e d in that the mould ( 21A) is mounted to a pivoted member (19) for displacement of the mould between a filling position between the mould core (22) and the measuring box (13) and an emptying position spaced 180° from the filling position and located below the mould core. 9. An apparatus as claimed in any of claims 3 to 8, c h a a c t e r i z e d in that the mould comprises a frame (33) forming the side walls of the mould, and a bottom (37) formed ' with one or more openings (38) for the mould core (22), which is mounted for limited movement transversely of the plane of the bottom inside the frame. OMPI 7 < λ Λ f* W WiiPKOU 10. An apparatus as claimed in claim 9, c h a r a c t e r i z e d in that the mould core (22) is provided with guide pins (46, 47) engageable with flanges (36) or the like on the outside of the frame (33) . 1-1. An apparatus as claimed in claim 9 or 10, c h a r a c t e r i z e d in that the bottom (37) is connected with bars (42) at one end thereof, said bars extending between the open upper and lower ends of the mould and being guided for displacement in the longitudinal directio.n thereof on the outside of the frame (33) while the bars have heads (43) at the other ends thereof to be engaged with the measuring box (13) and a lid (29A) arranged on the mould, respect vely. 12. An apparatus as claimed in claim 11 , c h a r a c t e r i z e d by a resilient seal provided between the edge of the frame (33) forming part of the mould, and the measuring-box (13).

Inventors: INGESTROEM C
Applicants: INGESTROEM C
Application year: 1979
Main classification: B28B7
IPC codes: B28B1, B28B7, B28B13