Apparatus for moulding hydraulic cement or the like material

• US 4,059,376 A
• Filed: 02/28/1977
• Issued: 11/22/1977
• Est. Priority Date: 11/24/1973
• Status: Expired due to Term

• Current Assignee: Taisei Corporation, Yasuro Ito
• Original Assignee: Taisei Corporation, Yasuro Ito
• Inventors: Yamamoto, Yasuhiro, Ito, Yasuro, Kaga, Hideharu, Sumita, Tadayuki
• Primary Examiner(s): Flint, Jr., J. Howard
• Application Number:
  US05/772,421
• Time in Patent Office: 267 Days
• Field of Search: 425/217, 425/242 R, 425/244, 425/405 R, 425/812, 425/DIG. 60, 249/141
• US Class Current: 425/546
• CPC Class Codes: B28B 1/24 by injection moulding injection moulding of ceramic slips B28B1/265; of tubular articles B28B21/38
• CPC Class Codes: B28B 23/0081 Embedding aggregates to obtain particular properties
• CPC Class Codes: B28B 7/0058 Moulds, cores or mandrels with provisions concerning the elimination of superfluous material; Moulds with burr-removing means provided therein or carried thereby
• CPC Class Codes: B28B 7/44 for treating with gases or degassing, e.g. for de-aerating treating with hot gases or vapour B28B7/42
• CPC Class Codes: E02D 27/01 Flat foundations
• CPC Class Codes: Y10S 425/06 Vacuum
• CPC Class Codes: Y10S 425/812 Venting

Abstract

Hydraulic cement or the like is poured into a closed mould under a reduced pressure condition to a level slightly higher than a predetermined level. Coarse aggregate and steel rods are prepacked in the mould. After pouring, the pressure in the mould is increased to atmospheric pressure or a higher pressure to force the hydraulic cement above the predetermined level back into the space below the level thus compacting the poured in hydraulic cement. A cushion device is provided for the pouring device. An overflow tank is connected to the mould to observe the level of the poured cement. The pressure in the overflow tank is also decreased during pouring and increased after pouring.

Claims

1. An apparatus for moulding a hydraulic substance comprising an injection tank, a moulding tank, and an overflow zone, said moulding tank being adapted to contain an aggregate, means for reducing the pressure in the moulding tank and in the overflow zone to a vacuum, means for introducing a cement and water mixture into the injection tank, means for transferring said mixture from the injection tank into the moulding tank in sufficient excess quantity to cause said mixture to overflow from the moulding tank into the overflow zone, and means for returning the overflow zone to at least atmospheric pressure, whereby at least a portion of said excess quantity of said mixture in the overflow zone is returned to the moulding tank to eliminate the voids between the aggregate in the moulding tank created by removing the excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially void-free product, said mixture being maintained in sufficient quantity in said overflow zone to avoid the introduction of air into the moulding tank.

2. The apparatus of claim 1, wherein the overflow zone is positioned above the moulding tank.

3. The apparatus of claim 2, wherein a perforated plate is disposed between the overflow zone and the moulding tank.

4. The apparatus of claim 1, wherein the overflow zone is a separate overflow tank which is positioned higher than the moulding tank.

5. The apparatus of claim 1, wherein the moulding tank and the overflow zone are disposed in a closed container and the means for reducing the pressure in the moulding tank and the overflow zone is a vacuum means which is operatively connected with the closed container.

6. The apparatus of claim 5, wherein the closed container is provided with a vent means which is closed by a valve means operatively associated therewith.

7. The apparatus of claim 4, wherein the overflow tank is provided with a vent means which is closed by a valve means operatively associated therewith.

8. The apparatus of claim 1, wherein a means is disposed at the point of introduction of the cement and water mixture to the moulding tank from the injection tank, said means functioning to increase the area at the inlet to the moulding tank to provide a smooth transition between the injection tank and the moulding tank and to reduce the tendency of the aggregate to block and reduce the effective area of transition between said tanks.

9. The apparatus of claim 8, wherein said means is a screen-like member.

10. The apparatus of claim 4, wherein the injection tank is disposed above the moulding tank.

11. The apparatus of claim 1, wherein the moulding tank is surrounded by an enclosure, and means are provided for evacuating the enclosure, said enclosure functioning as an intermediate chamber of reduced pressure formed between the atmosphere and the moulding tank, thereby protecting the environment in the moulding tank.

12. The apparatus of claim 4, wherein the injection tank is a closed tank and means are provided for evacuating said injection tank.

13. The apparatus of claim 1, wherein the injection tank is an open tank and a cushioning means is operatively disposed between the injection tank and the moulding tank.

14. The apparatus of claim 13, wherein the cushioning means is a closed tank and means are provided for evacuating said closed tank.

15. The apparatus of claim 14, wherein conduit means provide communication between the injection tank and the closed tank and between the closed tank and the moulding tank and valve means are provided in said conduit means between said tanks.

16. The apparatus of claim 13, wherein the cushioning means is an inverted U-shape tube which provides communication between the injection tank and the moulding tank, said inverted U-shape tube provided with a valve means.

17. The apparatus of claim 15, wherein a pump means is disposed in the conduit means between the injection tank and the closed tank.

18. The apparatus of claim 15, wherein a pump means is disposed in the conduit means between the closed tank and the moulding tank.

19. The apparatus of claim 13, wherein the cushioning means is a closed cylinder means and means are provided for evacuating said cylinder means.

20. The apparatus of claim 19, wherein conduit means provide communication between the injection tank and the closed cylinder and between the closed cylinder and the moulding tank and valve means are provided in said conduit means.

21. The apparatus of claim 20, wherein pump means are disposed in said conduit means between the injection tank and the closed cylinder.

22. The apparatus of claim 13, wherein the cushioning means is a bellows means and means are provided for evacuating said bellows means.

23. The apparatus of claim 22, wherein conduit means provide communication between the injection tank and the bellows means and between the bellow means and the moulding tank and valve means are provided in said conduit means.

27. The apparatus of claim 12, wherein a spreader means is disposed in the injection tank at a position beneath an opening for admitting said hydraulic substance, for removing excess water and entrained air from said hydraulic substance.

28. The apparatus of claim 27, wherein the spreader means is a triangular baffle plate.

29. The apparatus of claim 27, wherein the spreader means is provided with a vibrating means.

30. The apparatus of claim 12, wherein an open tank containing the hydraulic substance is connected to the injection tank and a throttle valve is positioned above the injection tank between said open tank and said injection tank for causing the hydraulic substance to drop into the reduced pressure atmosphere of the closed injection tank.

31. The apparatus of claim 12, wherein a vibrating means is mounted to the outside of the closed injection tank for vibrating the same to remove excess water and entrained air from the hydraulic substance.

32. The apparatus of claim 12, wherein the injection tank is an elongated, inclined, pipe-like element which is provided with an evacuating means and a vibrating means.

33. The apparatus of claim 1, wherein the overflow tank is connected to the moulding tank by a conduit means and said conduit means is filled with aggregate to a level higher than the moulding tank.

34. The apparatus of claim 33, wherein the conduit means contains a wire to prevent the coarse aggregate from filling the overflow tank.

35. The apparatus of claim 1, wherein the overflow tank is connected to the moulding tank by a conduit means and said conduit means and the lower portion of said overflow tank are filled with aggregate.

36. The apparatus of claim 35, wherein a wire is disposed above the aggregate to hold it in position.

46. The apparatus of claim 12, wherein vacuum means are operatively associated with both the upper and lower portions of the moulding tank.

47. The apparatus of claim 12, wherein means are provided for introducing the cement and water mixture from the injection tank into the bottom of the moulding tank.

24. An apparatus for moulding a hydraulic substance comprising a closed injection tank, a closed moulding tank and a closed overflow tank, said moulding tank being adapted to contain an aggregate, means for reducing the pressure in said tanks, conduit means connecting said pressure-reducing means to said tanks, an open supply tank operatively connected to the injection tank by conduit means, conduit means providing communication between said injection tank and said moulding tank, said conduit means containing a closed pump means which is also operatively connected with said pressure-reducing means, and a circulation conduit containing a pressure-regulating means, said circulation conduit being connected at one end to the injection tank and at the other end to the conduit between the moulding tank and the pump means, wherein a cement and water mixture is transferred from the open supply tank to the closed injection tank and, in turn, to the moulding tank in sufficient excess quantity to cause said mixture to overflow from the moulding tank into the overflow tank, and means are provided for returning the overflow tank to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow tank is returned to the moulding tank to eliminate the voids between the aggregate in the moulding tank created by removing the excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially void-free product, said mixture being maintained in sufficient quantity in said overflow tank to avoid the introduction of air into the moulding tank.

25. The apparatus of claim 24, wherein the pressure-regulating means is a pressure-regulating tank.

26. The apparatus of claim 24, wherein the pressure-regulating means is a pressure-regulating valve.

37. An apparatus for moulding a hydraulic substance comprising an injection tank, a moulding tank, and an overflow chamber, said moulding tank being provided with double-walled end portions which divide the moulding tank into a central moulding tank and two lateral absorption chambers, said central moulding tank being adapted to contain an aggregate and said lateral absorption chambers being adapted to contain an absorption material, said lateral chambers communicating with the central moulding tank, means for reducing the pressure in the injection tank, the central moulding chamber, and the overflow chamber, means for evacuating the lateral absorption chambers, means for introducing a cement and water mixture into the injection tank, means for transferring said mixture from the injection tank into the central moulding tank in sufficient excess quantity to cause said mixture to overflow from the central moulding tank to the overflow chamber and means for returning said overflow chamber to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow chamber is returned to the central moulding tank to eliminate the voids between the aggregate in the central moulding tank created by removing the excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially void-free product, said mixture being maintained in sufficient quantity in said overflow chamber to avoid the introduction of air into the central moulding tank.

38. The apparatus of claim 37, wherein the inner wall of said double-walled end portion contains an aperture which provides said communication between said lateral chambers and said central moulding tank.

39. The apparatus of claim 38, wherein said aperture contains a filter material.

40. The apparatus of claim 38, wherein said aperture contains a hydraulic substance detector.

41. The apparatus of claim 37, wherein said overflow chamber is an inverted U-shaped tube.

42. The apparatus of claim 37, wherein the overflow chamber is a transparent chamber.

43. The apparatus of claim 37, wherein said overflow chamber is a bellows-type device.

44. The apparatus of claim 37, wherein the overflow chamber is a coiled pipe.

45. The apparatus of claim 37, wherein the overflow chamber is a tank.

48. An apparatus for moulding a hydraulic substance comprising a closed injection tank, a mould adapted to contain an aggregate, and a closed overflow tank, said mould being disposed in a vacuum chamber, means for evacuating the injection tank, the vacuum chamber and the overflow tank, means for introducing a cement and water mixture into the injection tank, means for transferring said mixture from the injection tank into the mould disposed in the vacuum chamber in sufficient excess quantity to cause said mixture to overflow from the mould into the overflow tank and means for returning the overflow tank to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow tank is returned to the mould disposed in said vacuum chamber to eliminate the voids between the aggregate in the mould created by removing the excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially void-free, moulded product, said mixture being maintained in sufficient quantity in said overflow tank to avoid the introduction of air into the mould.

49. The apparatus of claim 48, wherein the overflow tank is transparent so that the quantity of cement and water mixture which overflows the mould can be monitored.

50. An apparatus for repairing a crack in a concrete structure which comprises a cover plate on all sides of said crack to seal the crack from the atmosphere, an injection tank and an overflow tank in the vicinity of said crack, means for reducing the pressure in said crack and in the injection and overflow tanks, means for introducing a cement and water mixture into the injection tank, means for transferring said mixture from the injection tank into the crack in sufficient excess quantity to cause said mixture to overflow from the crack into the overflow tank, means for returning the overflow tank to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow tank is returned to the crack to eliminate any voids which may have been produced in the mixture, by removing excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially void-free product, said mixture being maintained in sufficient quantity in said overflow tank to avoid the introduction of air into the crack.

53. The apparatus of claim 50, wherein the cover plate is a flat plate which extends across all sides of the crack and is flush with the outer surface of the concrete structure, said plate being provided with an air sealing member and a mortar sealing member.

54. The apparatus of claim 53, wherein the flat plates are provided with wedge-shaped filling members, said filling members being drawn toward the crack when a vacuum is applied to said crack, thereby increasing the sealing effect of the crack.

55. The apparatus of claim 54, wherein corner plates are disposed at the corners of the concrete structure between the flat plates and said concrete structure and tie bars are provided to connect opposing flat plates together.

51. An apparatus for interconnecting different portions of a concrete structure wherein a gap exists between said concrete structure and wherein said gap is adapted to be filled by a coarse aggregate, which comprises a porous cover around said aggregate disposed in said gap, means for applying a thin coating of concrete to said porous cover to seal said gap, an injection tank and an overflow tank disposed in the vicinity of said gap, means for reducing the pressure in said gap and in the injection and overflow tanks, means for introducing a cement and water mixture into the injection tank, means for transferring said mixture from the injection tank to the gap in sufficient excess quantity to cause said mixture to overflow from the gap into the overflow tank, means for returning the overflow tank to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow tank is returned to the gap to eliminate the voids between the aggregate in the gap created by removing the excess water and entrained air under reduced pressure, and means for replacing said voids with said cement and water mixture to produce a substantially void-free product, said mixture being maintained in sufficient quantity in said overflow tank to avoid the introduction of air into the gap.

52. The apparatus of claim 51, wherein the porous cover is an expanded metal.

56. An apparatus for moulding a hydraulic substance comprising an aggregate and a cement and water mixture, said moulding apparatus comprising an injection tank, a moulding tank adapted to contain an aggregate and an overflow tank, means for reducing the pressure in the injection tank, in the moulding tank, and in the overflow tank to a vacuum, means for introducing the cement and water mixture into the injection tank, means for transferring said mixture from the injection tank into the moulding tank in sufficient excess quantity to cause said mixture to overflow from the moulding tank into the overflow tank, and means for returning the overflow tank to at least atmospheric pressure whereby at least a portion of said excess quantity of said mixture in the overflow tank is returned to the moulding tank to eliminate voids between the aggregate in the moulding tank created by removing the excess water and entrained air under reduced pressure, and replacing said voids with said cement and water mixture to produce a substantially voidfree product, said mixture being maintained in sufficient quantity in said overflow tank to avoid the introduction of air into the moulding tank.

57. The apparatus of claim 56, wherein the overflow tank is disposed at a lever above the moulding tank.

58. The apparatus of claim 57, wherein the overflow tank is transparent.

59. The apparatus of claim 56, wherein the moulding tank comprises an air impervious sheet disposed in a recess formed in the surface of the ground and a hood mounted to the periphery of said sheet above said recess.