US 3604077 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent Inventor Richard L. Ruth, Sr.
Warren, Ohio Appl. No. 784,661 Filed Dec. 18, 1968 Patented Sept. 14, 1971 Assignee Sea Ferro, Inc.
Fort Lauderdale, Fla.
APPARATUS FOR MAKING MOLDED BODIES 12 Claims, 7 Drawing Figs.
US. Cl 25/118 R, 25/130 S, 9/6, 114/65 A, 264/328 Int. Cl 82% 7/02, B63b 5/16 Field of Search 18/4 C, 4
M, 26 M,47 C;25/1 A,2,41 1,413, 99, 100, 118 H, 118 J, 118 R, 118 T, 130A, 130B, 130C, 130 S; 9/6; 114/651; 264/328  References Cited UNITED STATES PATENTS 1,343,176 6/1920 Larsen 25/130 2,370,429 2/1945 Vidal.... 9/6 2,835,016 5/1958 Dixon... 25/100 X 2,913,798 11/1959 Breguct 25/118 X 3,013,922 12/1961 Fisher 9/6 X 3,296,675 1/1967 Filangeri 25/41 Primary Examiner-4.
Spencer Overholser Assistant Examiner-L. R. Frye Alt0rney--Williams and Kreskc ABSTRACT: Methods of and apparatus for manufacturing thin-walled, ferrocement bodies such as boat hulls by means of reusable, cooperable molds between which a cementitious mixture is injected by a novel pressurization device.
PATENTED SEPI 4 |97l sum 1 0F 5 INVENTOR. RICHARD L. RATH,SR.
PATENTEU SEP] 4 I97! sum 2 UF 5 INVENTOR. RICHARD LRATH, 52.
A T TOR/Vff PATENTED SEP 1 4 I97l 3 6 04 07 7,
' sum 3 [1F 5 INVENTOR.
RICHARD L. PATH,5R.
PATENIED SEP 1 4 12m $604107? sum or 5 INVENTOR.
A FOR/V575 \\..0 \J V. ll 1 ll lllllllll.
APPARATUS FOR MAKING MOLDED BODIES While concrete is relatively weak in resisting bending or tension stresses as compared to it strength in resisting compressive stresses, it has long been known that when metal reinforcing material is embedded in the concrete, a remarkable improvement in the strength of the concrete occurs. Indeed if a thin concrete panel is properly reinforced, such panel takes on much of the strength of the reinforcing material and behaves more like the latter in resisting stresses than it does like concrete alone. This principle has been increasingly utilized in the manufacture of boat hulls characterized by their great strength, virtually indefinite life with little or no maintenance, low material cost and surprisingly low weight.
I-Ieretofore, however, the manufacture of boat hulls from ferrocement, a name given to a thin panel of metal reinforced concrete which exhibits more of the characteristics of metal than it does of concrete, has been by hand, with attendant high labor costs and wide variations in quality dependent upon the skill and dedication of the labor employed.
SUMMARY OF THE INVENTION 7 element factor, more consistent, satisfactory results are obtained and, by mechanization, production is greatly increased with much lower unit costs.
The foregoing advantages of the instant invention are accomplished by providing cooperating molds between which the reinforcing material is positioned before injecting cementitious material between such molds. Novelty resides in the steps followed in disposition of the reinforcing material between the molds and subsequent injection of the cementitious material; in the manner of reuse of certain identical mold members with a cooperating mold member; in the manner of precuring the molded body prior to its removal from one of the mold members and its subsequent curing separated from the mold on which it was precured and in the novel mechanism employedin injecting the cementitious material and in other apparatus employed in carrying out the invention.
The foregoing and other advantages will readily become apparent from a study of the following description and from the appended drawings, and in these drawings:
DRAWING DESCRIPTION DETAILED DESCRIPTION With reference to FIGS. 1 and 2, there is shown apparatus comprising a plurality of substantially identical male mold members 10 through 19 having an exterior configuration corresponding, in the present instance, to the interior configuration of a boat hull to be molded, Such male mold members are adapted to circulate in the counterclockwise direction (see FIG. 2) along suitable conveyor rollers 20 and, while a total of ten male mold members areherein disclosed, a greater or lesser number may be employed where circumstances warrant.
Positioned above, and in registry with the male mold member 11, is a fixedly positioned female mold member 21 having an internal cavity corresponding to the exterior configuration of the boat hull to be molded. Disposed beneath the female mold 21 is an elevator 22 in the form of a hydraulic cylinder whose function is to raise a male mold (the mold II in the position of parts shown) to cooperating relation with the overlying female mold 21. As will later appear, when a male mold is elevated to cooperating relation with the female mold, a space is provided therebetween into which cementitious material in plastic form may be injected to form a boat hull.
Mounted above the female mold 21 is a novel device 23 for injecting cementious material into the space between the cooperating mold members and, while such device will later be described in detail, it will suffice for the moment to know that such device communicates with the hull-defining surface of the female mold by a plurality of conduits 24 terminating in spaced-apart injection nozzles or openings 24.1 at such mold surface.
Prior to injection of cementitious material between the female mold member and a cooperating male mold member, metal reinforcing material must be positioned to be embedded in the cementious material and as illustrated in FIGS. 1 and 2, a network of reinforcing material 25 is positioned on the exterior of the male mold member 10. i
With reference to FIG. 4 wherein the male mold member 10 is fragmentarily shown in enlarged detail, the reinforcing material and its method of use is as follows: A plurality of metal rods 26 are disposed in spaced, side-by-side relation on the male mold to extend transversely from gunwale to gunwale across the keel of the hull to be formed. Preferably, the male mold will be formed with grooves 27 for receiving and thus accurately locating respective rods 26. At the stern, located on the left as. viewed in FIG. 4, the rod 26 will extend from the gunwales and forwardly across the hull bottom for juncture, preferably by welding, to the nearest intersecting transverse rod 26. Any suitable means may be employed to retain the rods 26 assembled with the male mold and, as herein illustrated, a series of magnets 28 may be embedded in the male mold member. Such magnets may be permanent magnets or electromagnets as desired. In the event the rods 26 are of nonferrous material, the magnets 28 may be replaced by a suitable staple gripping mechanism which desirably would be designed to sever the staples used to hold the rods in place at a later operational stage.
Following disposition of the rods 26 on the male mold, one or more layers of metal mesh 29 will be overlaid upon the rods 26 over the entire working surface of the mold. Mesh 29 will preferably be spot welded to the rods 26; however, tie wires may also be used for this purpose if desired.
With the layers of metal mesh 29 secured over the rods 26, a plurality of metal rods 30 will be disposed over the mesh 29 in spaced side-by-side relation to extend from the bow of the hull to be formed, along both sides of the hull, and across the stern thereof. Rods 30 will preferably be welded to the layers of mesh 29; however, here again, the rods may be wired in position if desired. After the rods 30 have been affixed, they will in turn be overlaid with one or more layers of mesh 31 which may be identical to mesh 29. Mesh 31 will, of course, also cover the entire working surface of the mold and will be welded, or wired, to the rods 30.
Turning now to mold 11 (FIG. I) which, since it was earlier in the position of mold 10, has been covered with the reinforcing material 25 as hereinabove described, the elevator device 22 will now be actuated to raise the mold 11 to cooperating relation with the overlying female mold member 21 as seen in FIG. 3. Precise alignment of the mold members may be assured as, for example, by guide pins 32 carried by the male mold member and closely receivable in respective sockets in the female mold member.
With the male mold member 11 thus positioned in cooperating relation with the female mold member 21, a cementitious material in plastic, uncured form will be injected by the device 23 through the conduits 24 into the space between the cooperating mold members to completely fill such space and embed the reinforcing material 25. As seen in FIG. 5, the interior of the female mold member 21 is provided with spaced-apart ribs 33 generally coextensive with and in opposed relation to respective rods 26 of the reinforcing material 25. Such ribs, as will be evident, bear against the mesh 31 to insure that the latter is spaced slightly from the hull'defining surface of the female mold member so that such mesh will be embedded in the cementitious material C injected between the mold members. Following injection of the cementitious material between the mold members, male mold member 11, now covered with a'thin layer of cementitious material in which is embedded the reinforcing material 25,
will now be lowered by the elevator 22 to the position seen in FIG. 1.
Mold 12 (FIGS. 1 and 2) illustrates the stage of the operation after the cementitious material has been deposited on the male mold and the latter has been shifted to the right, along the conveyor, from beneath the female mold member 21. Note that the exterior of the body of cementitious material at this time (see also FIG. 6) has grooves 34 therein caused by the previously described ribs 33 in the female mold member. Such grooves, of course, are undesirable in the outer surface of a boat hull and therefore such grooves are adapted to be hand filled with uncured, plastic cementitious material to provide a hull body B whose outer surface is perfectly smooth as shown on the mold 13.
The hull B is now permitted to set up, or precure, for as long as necessary to permit its removal, without damage, from its mold. Assuming that the hull B on male mold 14 has been adequately precured, such mold will be inverted, by a suitable hoisting mechanism not herein shown, over a form 35 configurated to receive the hull. Upon inversion of the mold, the hull will, of course, gravitate therefrom to rest in the form 35. The form 35 will now be shifted as shown in FIG. 2 for final curing of the hull. Such final curing may take place in a natural environment or may, if desired, take place under closely controlled conditions of temperature and humidity.
After the hull B has been removed from the male mold, the latter will be inverted once again and recirculated for use with the female mold. Molds 15 through 19 illustrate various, successive male mold member positions prior to disposition of reinforcing material 25 thereon and subsequent cooperation thereof with the female mold 21 to form another hull body thereon. 7
Turning now to the specific construction of the injection device 23 as seen in FIGS. 1, 2 and 3, such device is shown to comprise a pressure-resistant tank 36 generally coextensive with the cavity in the female mold member 21. Disposed within and lining the interior of tank 36 is a flexible bladder 37. Attached to the underside of bladder 37 and preferably at the center portion thereof is a relatively large diameter pipe 38 for passing plastic, uncured cementitious material. Pipe 38, of course, passes through an opening in the wall of the tank 36 and communicates with the interior of the bladder but not with the interior of the tank. Pipe 38 extends from the bladder 37 to a mixer 39 (FIG. 2) and a check valve 40 is interposed in pipe 38 for a purpose to appear. Mixer 39 is adapted to mix the various constituent materials making up the cementitious material and is adapted to pump such material through the pipe 38, past the check valve 40, and into the bladder 37.
Extending through the wall of tank 36 and from the lower portion of bladder 37 and in communication with the interior of the latter but not with the interior of the tank, are the previously mentioned conduits 24 which terminate in respective, spaced-apart injection nozzles 24.1 at the inner surface of the mold cavity. Extending from an upper portion of tank 36 is a conduit 41 in communication with the interior of the tank but not with the interior of the bladder 37. Conduit 41 extends from the tank to a suitable source of fluid pressure, such as a hydraulic pump unit, seen at 42 in FIG. 2.
In operation and assuming a lower male mold is positioned in cooperating relation with the female mold as seen in FIG. 3, uncured cementitious material in an amount somewhat greater than that required to fill the space between the two mold members will be pumped through the pipe 38 into the bladder 37.
When sufficient cementitious material has been pumped into the bladder, pressurized hydraulic fluid will be introduced into the tank 36 through the conduit 41. With hydraulic fluid under sufficient pressure within the tank and about the bladder 37, the latter will be collapsed, as seen in phantom lines, thus forcing the cementitious material through the conduits 24 and into the space between the two molds where it diffuses through the interstices in the reinforcing material. It will be noted that the check valve 40 in the pipe 38 functions to prevent the cementitious material being forced from the bladder to the mixer.
Since it may be necessary to maintain the molds together, and to also maintain hydraulic pressure on the bladder, for some time after injection of the cementitious material in order to allow the latter to begin to set up sufficiently that it will stay in position on the male mold as it is lowered from the female mold cavity, it is essential that the cementitious material remaining in the bladder 37 and in the conduits 24 and the injection nozzles 24.1 be flushed out before another injection operation is commenced. Accordingly, after the male mold member bearing the hull of cementitious material thereon is moved from beneath the female mold member, the bladder may be filled with water through a suitable inlet line 43 which intersects the pipe 38 and is provided with a valve 44 for controlling flow of water therethrough. As the bladder is filled with water, the hydraulic fluid within the tank and about the bladder will be allowed to return to its source so that the bladder will again be fully distended.
With the bladder filled with water and with any cementitious material remaining therein from the previous injection operation, hydraulic pressure will again be admitted to the tank to again collapse the bladder. Valve 44, of course, will be closed before hydraulic fluid is again admitted to the tank. This will force the contained cementitious material from the bladder the conduits 24 along with the water with which the bladder was filled. The bladder will be collapsed completely by hydraulic pressure to ensure complete ejection of the water so as not to dilute the next batch of cementitious material to be charged into the bladder.
With the bladder 37 and conduits 24 thus flushed clean, (it may also be advisable to manually hose out the female mold cavity at this time), the next male mold member with the reinforcing material 25 thereon may be shifted beneath the female mold member and raised to cooperating position therewith. The bladder 37 may again be charged with cementitious material as before and such material then injected between the mold members as previously described to form another hull body.
While the construction thus far disclosed contemplates forcing the cementitious material through conduits 24 terminating in simple openings 24.1 in the face of the female mold cavity, it may be desirable to control flow of such material through individual ones of such openings.
With reference to FIG. 7 which shows elements similar to those shown in FIG. 5, parts corresponding to those heretofore described are identified by the same reference characters as before but with the suffix a added. As illustrated, a fluid cylinder 45 has a piston rod 46 in alignment with the nozzle or opening 24.1a for movement thereinto as will appear for purpose of closing the latter. Normally, piston rod 46 is retracted as shown whereby the plastic cementitious material Ca may flow from the conduit 24a through the nozzle 24.10 to the space between the mold members.
When, however, it is desired to close off the nozzle 24.10, piston rod 46 will be extended until its free end is flush with the adjoining face of the female mold cavity. In moving from its retracted position shown to its described extended position,
each piston rod 46 will push the cementitious material ahead of it into the space between the molds thus insuring against voids'in the molded hull body and, by retaining all of the piston rods in extended position until the male mold is to be lowered from the female mold, high pressure will be maintained upon the cementitious material mass between the mold members for improved density thereof.
In order to facilitate flow of the cementitious material through and about the reinforcing members 26a, 28a, 30a and 31a, vibrationmay be employed and in the embodiment of the invention seen in FIG. 7, the lower mold member mounts suitable vibration means 47. Preferably, a vibration device is mounted in opposed relation to each injection nozzle 241a to assist in dispersion of the cementitious material from the nozzles.
1. Apparatus for the manufacture of molded bodies, which comprises a plurality of mold members one of which is cooperable with each of the others to provide a body-defining space for receiving moldable material in plastic form which subsequently sets to form a body, said one member being an uppermold member and said other mold members being lower mold members generally identical with each other,
and means for relatively shifting said upper mold member and an underlying lower mold member toward and away from operable relation with each other, said lower mold members being successively cooperable with said upper mold member to form respective bodies thereon and said lower mold members becoming available for reuse with said upper mold member to form another body thereon when the body previously formed on a lower mold member has set sufficiently to permit its removal therefrom.
2. The construction of claim 1 and further comprising a plurality of spaced-apart injection nozzles in said upper mold member and in communication with said space between said upper mold member and a cooperating lower mold member,
and means connected with said nozzles for forcing said moldable material in plastic form through said nozzles and into said space thus forming the body aforesaid.
3. The construction of claim 2 wherein said means last-mentioned comprises a container having rigid walls,
a flexible liner for receiving plastic moldable material, said liner being disposed within said chamber and the interior of said liner communicating with said nozzles,
and means for introducing fluid under pressure into said container and about the exterior of said liner to collapse the latter and thus force said moldable material therefrom and through said injection nozzles.
4. The construction of claim 3 and further comprising means for introducing said plastic moldable material into said liner.
5. The construction of claim 4 wherein said material introducing means comprises an inlet conduit connected to said liner,
and valve means preventing flow of said material through said conduit in a direction away from said liner.
6. The construction of claim 2 and further comprising a plurality of vibratory devices carried by each lower mold member aforesaid to insure even distribution of said moldable material throughout said space between said upper and lower mold members.
7. The construction of claim 6 wherein each of said vibratory devices is carried by said lower mold member in opposed relation with one of said upper mold member injection nozzles.
8. The construction of claim 2 wherein a cutoff valve at each injection nozzle closes the latter generally flush with the body-defining surface of said upper mold member after each material injection cycle.
9. The construction of claim 1 wherein said upper mold member is a female mold member and said lower mold members are male mold members,
and wherein each male mold member has spaced-apart grooves in its body-defining surface for receiving respective, elongated metal reinforcing members for locating the same.
10. The construction of claim 1 wherein said upper mold member is a female mold member and said lower mold members are male mold members,
wherein the body-defining surface of each male mold member is adapted to be overlaid with reinforcing material prior to its disposition in operable relation with said female mold member,
and wherein the body-defining surface of said female mold member is provided with projections engageable with said reinforcing material to maintain the latter spaced from its surface aforesaid.
11. The construction of claim 10 wherein each male mold member has spaced-apart grooves for receiving respective, elongated metal members forming at least a part of said reinforcing material.
12. The construction of claim 11 wherein said female mold member projections are in opposed relation with said male mold member grooves.