US3427009A

US3427009A - Apparatus and method for handling concrete blocks

Info

Publication number: US3427009A
Application number: US588559A
Authority: US
Inventors: Harry Norman Shute
Original assignee: Shute Concrete Products Inc
Current assignee: Shute Concrete Products Inc
Priority date: 1966-10-21
Filing date: 1966-10-21
Publication date: 1969-02-11
Anticipated expiration: 1986-02-11

Description

Feb. 11, 1969 H. N. SHUTE 3,427,009

APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Filed Oct. 21, 1966 Sheet 0114 F|Gl T" as 35 M/ VEN TOR HARRY NORMAN SHUTE BY mw a A TTORNEYS Feb. 11, 1969 SHUTE 3,427,009

APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Filed Oct. 21, 1966 Sheet 2 of 4 'VTTVTT AJL TI T

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(Ii-I Q-LP H. N. SHUTE Feb. 11,1969

APPARATUS AND METHOD FOR HANDLI\NG CONCRETE BLOCKS Filed Oct. 21, 1966 1969 H. N. SHUTE APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Filed Oct. 21, 1966 Sheet FIG-1O United States Patent 3,427,009 APPARATUS AND METHOD FOR HANDLING CONCRETE BLOCKS Harry Norman Shute, Shute Concrete Products, Inc., 4810 Woodside Drive, Richmond, Ind. 47274 Filed Oct. 21, 1966, Ser. No. 588,559 US. Cl. 26328 20 Claims Int. Cl. F27b 3/12, 9/00; B281) /00 ABSTRACT OF THE DISCLOSURE Racks of concrete blocks are delivered from a rack loading station to an open top steam curing kiln and are arranged in horizontally spaced relation with a cover for the kiln being formed by a plurality of substantially rigid panels arranged in a coplanar relation. After the blocks on each rack are cured, the rack is lifted from the kiln and delivered to a rack unloading station, after which the blocks are arranged in the form of cubes which are delivered to a storage rack and arranged in tiers on gravity feed roller conveyors.

This invention relates to the production of concrete blocks, and more particularly, to an improved method and apparatus for efiiciently handling and curing concrete blocks with reduced labor and equipment costs so as to produce blocks at a minimum unit cost. The term concrete blocks as used herein is intended to include all forms of concrete modules which are adapted to be used as structural or decorative members of a building or other structure.

Concrete blocks are commonly produced by an automatic block machine which forms batches of blocks on steel pallets which are successively supplied to the ma chine. The pallets of fresh concrete blocks are loaded into a series of racks by an automatic loading machine and each loaded rack is then transported, commonly by a power operated fork-lift truck, to a tunnel-like kiln through an open end of the kiln. After the kiln is filled, it is closed usually by a hinged door and steam is introduced for providing a hot, humid atmosphere for a period of several hours to cure the blocks.

After the curing operation, the kiln is opened, and each rack of blocks is transported, such as by a fork-lift truck, from the kiln to automatic unloading equipment which removes each pallet of cured blocks from the rack. The blocks are then processed through a separating machine where each batch of block is removed or separated from its supporting steel pallet and the pallets are successively returned to the block machine for use in forming new blocks.

After the cured concrete blocks are separated from the steel pallets, the blocks are usually transferred by a conveyor to a cubing machine which automatically collects and stacks a predetermined number of blocks to form a large cube. The cube is subsequently transported to a storage area or yard, again usually by a fork-lift truck which either engages a wooden pallet supporting the cube or the bottom layer of blocks in the cube.

It has been found that considerable investment is required in the construction of the tunnel-like kilns and in the fork-lift trucks which are used to transport the racks to and from the kilns and in transporting the palletized cubes to the storage yard. In addition, it has been found that the labor cost for the truck operators is a significant cost and, of course, these costs are reflected in the selling price of the blocks.

Accordingly, it is a primary object of the present invention to provide an improved method and apparatus "Ice for handling and curing concrete blocks to minimize the cost in producing the blocks.

It is also an object of the invention to provide novel apparatus which is adapted for providing automatic or semi-automatic transfer or processing of the blocks to and from the curing kiln and to the storage yard.

Another object of the invention is to provide apparatus including a novel curing kiln having an open top for receiving a substantial number of curing racks, and further including an overhead crane system for moving each rack from the rack loading machine to the kiln and then to the rack unloading machine.

Still another object of the invention is to provide apparatus as outlined in the preceding paragraph wherein each rack carries a cover member which cooperates with the cover member of adjacent racks when the racks are within the kiln to form an overall top cover for the kiln.

It is also an object of the invention to provide apparatus as outlined above and including sealing means for preventing the escape of steam from the kiln between the cover members on the racks during curing of the blocks.

Still another object of the invention is to provide apparatus including a novel storage rack and means for automatically transferring and loading palletized cubes of cured blocks into the storage rack.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings- FIG. 1 is a somewhat diagrammatic plan view of apparatus constructed in accordance with the invention and showing a curing kiln also constructed in accordance with the invention;

FIG. 2 is a vertical section through the kiln as taken generally along the line 22 of FIG. 1;

FIG. 3 is a perspective view of a typical guide member for maintaining uniform orientation of the block supporting racks within the kiln;

FIG. 4 is a fragmentary section of a portion of a loaded kiln as taken generally along the line 4 4 of FIG. 1;

FIG. 5 is a plan view of the kiln with the racks removed and showing diagrammatically the means for producing steam and venting each compartment of the kiln;

FIG. 6 is a section of a steam generating trough as taken generally along the line 66 of FIG. 5;

FIG. 7 is a fragmentary section of adjacent cover members and showing means for forming a vapor seal therebetween;

FIG. 8 is a perspective view of a typical rack removed from the kiln and showing two pallets of blocks supported thereby;

FIG. 9 is a perspective view of a storage rack and as sociated loading equipment constructed and arranged in accordance with the invention;

FIG. 10 is an end elevational view of the storage rack and loading equipment shown in FIG. 9; and

FIG. 11 is a perspective view of a modified form of the apparatus of the invention.

Referring to the drawings which illustrate preferred embodiments of the invention, FIG. 1 shows an automatic block forming machine 15 which successively forms batches of blocks B (FIG. 2) on successively supplied steel plate-like pallets 16. The pallets of blocks are conveyed from the block machine 15 to an automatic racking machine 18 which loads the pallets 16 into racks 20 (FIG. 8) at difierent elevations or tiers formed by angle support members 21 extending laterally between legs 22 rigidly connected by upper longitudinal members 23.

Each rack 20 includes a cover member 25 which preferably is formed from a rigid insulated water and steam proof material, as for example, a laminated sheet manufactured by Johns-Manville and including an insulation core 26 (FIG. 7) spaced between a pair of rigid asbestos sheets 27. Surrounding each cover member 25 is a resilient seal 28 including a flexible casing 29 covering a resilient sponge-like material 31. The casing 29 is secured to the sheets 27 by a series of top and bottom screws 32. The racks 20 also include hanger or support rods 34 which extend through the cover member 25 and are rigidly secured to the end support legs 22.

The racks 20 are normally stored in a pit-like kiln 35 (FIGS. 1, Z and which includes side walls 36 adjoining end walls 37 and intermediate walls 38 which divide the kiln into compartments 40 each having an open top. The open top is preferably at or near ground level, although the entire kiln of this invention may be placed above ground level. The

walls

36, 37 and 38 of the kiln are preferably constructed on concrete blocks and are supported by a poured concrete floor 41 in which are formed series of parallel, spaced rectangular troughs 42 extending between the side walls 36 with one or more troughs in each compartment 40. A layer 43 of insulating material, as for example, polyurethane board is provided adjacent the outer surface of the

walls

36 and 37 and a corresponding layer 44 is provided under the floor 41 to minimize the transfer of heat from the kiln into the surrounding earth. For purposes of illustration, each compartment 40' of the kiln 35 is sufficiently large to enclose a group of racks 20 (FIG. 1). As shown in FIG. '2, the lifting racks 20 each have a height which corresponds substantially to the vertical depth of the kiln 35.

An air inlet manifold 45 (FIGS. 2 and 5) extends longitudinally along one side wall 36 of the open top kiln 35 and connects with upper and lower inlet ducts 47 for supplying air to each compartment 40 of the kiln from a blower 48. A corresponding exhaust manifold 50 extends longitudinally along the opposite side wall 36 and is connected to each compartment 40 of the kiln by upper and lower ducts 51 for venting or exhausting air supplied through the inlet ducts 47. A remotely controllable valve member or damper 52 is provided in each of the

ducts

47 and 51 for controlling the flow of air through each compartment 40 of the kiln 35.

A series of guide members 55 (FIGS. 2 and 3) each having tapered surfaces 56, are mounted on the floor 41 within each compartment 40 of the kiln 35 for receiving the corner legs 22 of the racks 20. The guide members 55 cooperate in maintaining uniformly aligned relationship between adjacent racks 20 with the abutting seals 28 in uniform pressure contact so that when the racks 20 are in place in the kiln the cover members 25 cooperate with the

walls

36, 37 and 38 to form a relatively air tight and steam impervious insulating top cover for each compartment of the kiln. The individual cover members 25 thus align into coplanar relation over the kiln section forming a relatively rigid surface on which an operator may safely walk, if necessary.

A V-shaped metal trough 58 (FIG. 6) having end walls 59 is mounted within each of the rectangular concrete troughs 42 formed within the floor 41. A conduit 60 (FIGS. 5 and 6) extends longitudinally within each trough 58 from a main supply line 61. Low pressure steam, hot oil, or other heated fluid is circulated within each conduit 60 for heating a predetermined quantity of water 62 supplied to the corresponding trough 58 to produce vapor or steam in each compartment 40' of the kiln during the curing operation.

For transporting each of the racks 20 between the kiln 35 and the racking machine 18, the apparatus of the invention includes a bridge crane 65 (FIGS. 1 and 11) including a pair of parallel extending rails 66 (FIG. 11) which are connected by laterally extending members 67 supported by wheels 68 which roll on parallel spaced tracks 69 extending parallel to the side walls 36 of the kiln 35. Preferably the wheels 68 are driven by a motor 70 (FIG. 11).

A trolley or carriage 72 is supported by the rails 66 for traversing movement between the tracks 69 and is powered by a motor 73. The carriage 72 supports a vertically extendable frame 75 which is powered by a motor 76 and carries clamping or grab hooks (not shown) for gripping the hanger rods 34 on each rack 20. As shown in FIG. 1, the bridge crane 65 not only travels over the entire kiln 35 but also travels over the racking machine 18 so that each rack 20 can be lifted from the kiln 35 and transported to the racking machine 18 for loading the pallets of new blocks B into the racks.

After the blocks are cured within the kiln, each rack 20 is lifted by the overhead crane 65 from the kiln 35 and transported back to the racking machine 18 where the pallets 16 of cured blocks are automatically unloaded from the racks and are then transported to a separating machine 80 where the blocks are removed from the pallets 16. The pallets are then transported by a conveyor 81 back to the block machine 18 to be reused for forming blocks.

The conveyor 82 transports successive rows of blocks from the separating machine 80 to a cubing machine 85 which stacks several layers of blocks onto a wooden pallet '87 (FIG. 9) to form a cube C. A typical cube C may include various numbers of blocks depending upon the size of the blocks. Each pallet 87 of blocks is deposited by the cubing machine on a self-propelled platform car 88 (FIG. 9) having front wheels 89 straddling an endless rail 90.

The endless rail 90 extends from the cubing machine 85 to the receiving side of a storage rack and then back to the cubing machine. The storage rack 95 is constructed with a series of parallel spaced vertical posts 96 connected at the top by cross members 97. A series of rollers 98 are mounted on each of the posts 96 and cooperate with corresponding rollers on adjacent posts to form several tiers within the rack. The rollers 98 defining each tier are arranged in sloping relationship as shown in FIG. 10. Preferably the storage rack is intended to be under cover, however, the rack may be installed outside a building.

Extending above the track 90 adjacent the receiving side of the storage rack 95 is a bridge crane 100 which includes parallel spaced tracks 102 supported by wheels (not shown) mounted on laterally extending tracks in the same manner as the bridge crane 65. A trolley or carriage 104 powered by a motor 105, is supported by the rails 102 for traversing movement across the receiving side of the rack. A vertically extendable frame 106 is suspended from the carriage 104 and supports parallel spaced fork members .107.

As each platform car 88 carrying a palletized cube of blocks approaches the storage rack 98, the fork members 107 are inserted into the pallet 87 and the cube of blocks is lifted from the car and elevated to one of the storage tiers within the storage rack 95 as shown in FIG. 10. The frame 106 is then rotated 90 after which the crane moves toward the storage rack and the fork members 107 deposit the cube of blocks on the rollers 98 so that the pallet of blocks move by gravity towards the discharge side of the rack. After each pallet of blocks is removed from a platform car 88, the car automatically continues on the endless track 90 to the cubing machine 85 for receiving another palletized cube of blocks.

Referring to FIG. 11, which shows a modified form of apparatus constructed in accordance with the invention, the vertically extendable frame 75 of the bridge crane 65 supports a rectangular frame 110 from which depends a series of pivotally mounted arms 112 each having a hooked shape lower end portion 113. The arms 112 are simultaneously opened and closed by corresponding links 1'14 which connect the arms to eccentric locations on corresponding actuating disks 115 rotatably driven by a reversible motor 116. Each cover member 25' of the racks 20' is formed with spaced apart slots 119 which enable the gripping arms 112 of the bridge crane 65 to engage the longitudinal upper frame member 23 of the rack for lowering and raising each of the racks into and from the kiln 35.

After each compartment 40 of the open top kiln 35 is loaded with racks 20' of fresh concrete blocks, a roll of flexible water and steam impervious tarpaulin 120 is rolled over the top of the cover members 25 to seal the compartment 40 and prevent the escape of steam from between the cover member or through the slots 119 during the curing process. The tarpaulin 120 is preferably formed from a neoprene-coated nylon fabric. Thus in the modification shown in FIG. 11, the tarpaulin 120 replaces the seals 28 which surround the cover members 25 shown in FIGS. 7 and 8.

To cure the fresh concrete blocks loaded within the kiln 35, steam or hot oil is introduced into the conduits 60 and a predetermined quantity of 'water is supplied to the troughs 58. The heat produced by the seam or hot oil within the conduits 60 causes the water within the troughs to evaporate and produce a hot humid atmosphere in each of the compartments of the kiln. The compartments are maintained at the desired temperature for the time required to complete low pressure steam curing. After this period, the hot humid air in each of the compartments is exhausted by introducing a supply of fresh air through the inlet manifold 45 from the blower 48. The hot humid air is thereby exhausted through the manifold 50 to the outside so that when the racks 20 or 20' are removed, none of the hot humid air escapes into the working space directly above the kiln.

From the drawings and the above description, it can be seen that apparatus constructed in accordance with the invention provides desirable features for curing and bandling concrete blocks. Basically, it has been determined that the construction of the open top kiln 35 substantially reduces the construction cost of the kiln when compared to the conventional oven or tunnel-type kilns. Since the kiln is preferably recessed below ground level, heat loss is also reduced. Furthermore, the combination of the open top kiln 35 along with racks each carrying a cover member and a bridge crane adapted to transport each rack from the kiln to the racking machine 18, provides for a simplified and efiicient method of handling the blocks from the rack loading portion of the racking machine 18 to the curing kiln 35 and then back to the unloading portion of the racking machine. The compartmentalized construction of the kiln 35 also enables the compartments to be used separately. Thus blocks may be cured in one compartment wile loading or unloading another compartment.

Another important advantage of the apparatus of the invention is that each movement of the bridge crane 65 may be easily controlled automatically, as for example, from a tape control system programmed with the necessary information for successively transporting each rack from the kiln 35 to the racking machine .18 for automatic unloading of cured blocks and transporting a rack loaded with fresh blocks back to the kiln. It has been determined, however, that even without an automatic control system, the apparatus substantially simplifies the handling and curing of the blocks.

Another desirable feature of the apparatus of the invention is the handling of each palletized cube of blocks as received on the platform cars 88. That is, the combination of the storage rack 95 (FIGS. 9 and 10) and the bridge crane 100, enables each palletized cube to be removed from its corresponding car 88 and deposited into the storage rack at one of the levels or tiers defined by the supporting rollers 98 and thereby enable the blocks to be easily and conveniently removed from the opposite side of the storage rack as the blocks are loaded for shipment. Furthermore, by controlling each movement of the bridge crane 100 with a programmed magnetic or punched tape, each cube of palletized blocks can be automatically loaded onto the receiving side of the storage rack without employing an operator.

Thus it becomes apparent that by employing the apparatus of the present invention in conjunction with commercially available automatic block forming and racking machines together with an automatic pallet unloader and cubing machine, fresh concrete blocks can be formed, cured and delivered in the form of palletized cubes to the storage rack 95 with optimum efficiency and minimum labor cost. Furthermore, the apparatus of the invention enables the blocks to be automatically or semiautomatically processed with a minimum capital investment for equipment. For example, the open top kiln is much less expensive to construct than a tunnel-type kiln, consumes less space, and the bridge cranes 65 and may be installed with substantially less investment than would be required for suitable fork-lift trucks capable of handling the same production of blocks. In addition, the apparatus can 'be installed in substantially less space. That is, no floor space is required for maneuvering forklift trucks or for storing racks either before or after the loading and unloading of blocks into the racks.

While the form of apparatus and process herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus and process, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. Apparatus for efficiently handling and curing concrete blocks formed in successive batches on a series of pallets, comprising a kiln including a floor and side walls defining an open top chamber, means for introducing steam into said chamber, a plurality of separate racks within said chamber and arranged in horizontally spaced relation, each said rack being independently removable from said chamber, removable top cover means for said kiln, means for loading pallets of blocks into each said rack, means for unloading the pallets of blocks from each said rack, means for transporting each said rack between said loading means and said kiln and between said kiln and said unloading means, and said transporting means including a vertically extendable rack engaging member for lowering each said rack into said chamber for curing of the blocks thereon and for raising each rack from said chamber after curing.

2. Apparatus as defined in claim 1 wherein said transporting means comprises a bridge crane, horizontally extending track means supporting said crane, and said Vertically extendable rack engaging member includes rigid guide means connected to said crane for maintaining positive orientation of each said rack relative to said crane.

3. Apparatus as defined in claim 1 wherein said removable top cover means for said kiln includes a top cover member on each said rack, said top cover members disposed in generally coplanar relationship when said racks are in said kiln for cooperatively forming a top cover for said kiln, and means for sealing said cover members to avoid the escape of steam between said cover members during curing of the blocks.

4. Apparatus as defined in claim 3 wherein said sealing means includes a flexible tarpaulin extending over said cover members and adapted to be rolled up during moving of said racks into and out of said kiln.

5. Apparatus as defined in claim 3 wherein said sealing means includes a resilient sealing member extending around the periphery of each said cover member.

6. Apparatus as defined in claim 1 including at least one vertically extending intermediate wall within said kiln for separating said kiln into a plurality of open top compartments, air vent means for each said compartment, and said means for introducing steam into said kiln includes separately controllable means for introducing steam into said compartments to provide for curing blocks in a portion of said kiln.

7. Apparatus as defined in claim 1 including means for cubing cured blocks on a pallet, a storage rack having a receiving side and a discharge side and including means for supporting a plurality of tiers of pallets of cured blocks, means for loading said pallets of blocks into each said layer of said storage rack, and means for transporting each said pallet of blocks from said cubing means to said loading means for said storage rack.

8. Apparatus as defined in claim 7 wherein said supporting means on said storage rack for each tier includes a series of aligned rollers arranged in sloping relationship towards said discharge side of said storage rack, said loading means for said storage rack including an overhead bridge crane, said transporting means including an endless track extending from said cubing means to said storage rack, a plurality of power driven cars each including means for supporting a pallet of cubed blocks, and each car including means for engaging said track for directing said car from said cubing means to said bridge crane and then back to said cubing means.

9. An improved method for efficiently handling and curing concrete blocks formed in successive batches on a series of pallets, comprising the steps of loading said pallets having blocks thereon onto a plurality of racks, transporting each said rack by lifting and carrying said rack with a crane to a kiln having an open top, lowering each said rack by said crane down into said kiln and arranging said racks in horizontally spaced relation within said kiln to permit independent removal of each said rack from said kiln, covering said kiln, introducing steam into said kiln for curing said blocks, lifting each said rack from said kiln by said crane after the blocks are cured, and transporting each said rack by said crane rack unloading means.

10. A method as defined in claim 9 wherein each said rack includes a cover member mounted thereon, and including the step of placing a flexible tarpaulin over said cover members to prevent steam from escaping from between said cover members.

11. A method as defined in claim 9 including the steps of separating the pallet from each batch of cured blocks, stacking and cubing the blocks on wooden pallets, successively transporting the pallets of stacked blocks on independently driven cars to a gravity discharge storage rack, and successively loading the pallets of stacked blocks into said storage rack with an overhead crane.

12. A kiln for use in the curing of newly manufactured concrete blocks comprising a substantially water impervious floor and side walls defining a generally rectan ular chamber having an open top, means for introducing heat into said chamber, a plurality of substantially identical separate racks positioned within said chamher and arranged in horizontally spaced relation, each said rack having means for supporting a plurality of newly made concrete blocks and being independently removable from said kiln, and means forming a substantially steam impervious removable cover for said chamber when said racks are in place therein.

13. The concrete block curing kiln of claim 12 in which said cover means comprises individual cover segments carried substantially at the top of each of said racks which align in substantially coplanar position with each other when said racks are in place in said kiln.

14. The concrete curing kiln of claim 12 in which said cover means comprises a plurality of generally rectangular and substantially rigid cover members arranged in substantially coplanar relation.

15. The concrete curing kiln of claim 12 including at least one intermediate vertical wall within said chamber for dividing said kiln into a plurality of open top compartments and a plurality of horizontally spaced racks in each said compartment.

16. A storage rack for a plurality of pallets each having a group of concrete blocks thereon, comprising a plurality of generally parallel spaced vertical posts arranged in a plurality of rows, adjacent said posts spaced apart to receive a pallet of blocks therebetween, and roller means connected to said posts and arranged in vertically spaced relationship for supporting corresponding tiers of pallets having blocks thereon.

17. A rack as defined in claim 16 wherein said roller means connected to said posts for supporting each said tier of pallets are arranged in sloping relationship to provide for gravity movement of the pallets of blocks towards one side of said rack.

18. Apparatus for curing concrete blocks comprising a pit-like kiln having side walls and a bottom defining an open top chamber, rack means received in said kiln through said open top for supporting a plurality of concrete blocks for curing, trough means in said kiln bottom for receiving a quantity of Water for vaporizing into steam during curing, means in said trough means for vaporizing said water, vent means in one of said walls for admitting air into said kiln, and insulating means for covering said open top chamber with said rack means in place for preventing the escape of steam therefrom during curing.

19. Apparatus of claim 18 further comprising partitions in said kiln dividing said kiln into a plurality of separate curing chambers, and said insulating means comprising a separate forming cover for each of said chambers.

20. The apparatus of claim 18 in which said insulating means comprises rigid sheet material.

References Cited UNITED STATES PATENTS 1,407,193 2/1922 Diescher 18-4 X 1,482,187 1/1924 Hatch 252 2,990,069 6/1961 Repasky et al 252 X 3,325,870 6/1967 Lacy et al 252 FREDERICK L. MATTESON, JR., Primary Examin r.

E. G. FAVORS, Assistant Examiner.

US. Cl. X.R.