US3224726A

US3224726A - Flexible panel form for thin shells

Info

Publication number: US3224726A
Application number: US418494A
Authority: US
Inventors: Graham Phillip
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-12-15
Filing date: 1964-12-15
Publication date: 1965-12-21
Anticipated expiration: 1982-12-21

Description

Dec. 21, 1965 P. GRAHAM 3,224,726

FLEXIBLE PANEL FORM FOR THIN SHELLS Filed Dec. 15, 1964 5 1 i? 307 '35,; 5 6 5 i "w'."" 1i F 4b M INVENTOR. Phi/lip Graham RNEY United States Patent ()fitice 3,224,726 Patented Dec. 21, 1965 3,224,726 FLEXIBLE PANEL FORM F OR THIN SHELLS Phillip Graham, 2825 Glenrnore Ave., Pittsburgh, Pa. Filed Dec. 15, 1964, Ser. No. 418,494 9 Claims. (Cl. 249207) This invention relates to improvements in flexible form for molding thin shell building panels, including adjustable flexible elastic edge forms which can be used to cast curved and flat, thin shell, reinforced panel sections of cementitious materials and plastics, which panel sections can be readily interlocked or bonded together to obtain an integral buildingshell of great strength. This invention is a c-ontinuation-in-part of my copending application Serial No. 86,814, now Patent No. 3,161,938, filed February 2, 1961, entitled Flexible Panel Form for Thin Shells. Applicant also claims rights to an earlier filing date to common subject matter that is describe-d in the present application, which was also described in his application Serial No. 785,273, filed January 6, 1959, now Patent No. 2,971,237, entitled Flexible Building Panel Form. The copending application Serial No. 86,814 was a continuation-in-part of application Serial No. 785,273.

This invention particularly refers to adjustable forming means that has durable elastic flexible edge forms that allow low cost, quick and accurate molding of various shapes and sizes of curved and flat, precast, prestressed, reinforced thin shell concrete panel sections.

My Patent No. 3,154,888, entitled Building Construction, and my Patent No. 2,971,237, describe'how panels formed with such flexible forms can be used to build shelters; in addition, these patents list my numerous related patents that supplement the flexible form means in building shelters.

The form means allows multiple curved thin shell, precast panels to be molded accurately at low cost. The form means allows accurate positioning of fastening means along the edges of the-panels so the panels can be quickly and securely joined at erection. This fastening means allows precast sections to be erected dry with pins during inclement weathergrout mortar being inserted in the joints at a later suitable period. Non-elastic panel portions of the form means can be made of concrete; they can be used to mold the curved faces of the precast building panels, such concrete panel forms may be used as building panels after they have outlived their usefulness as forms.

The form means embodied in this invention is an improvement over the form means described in my Patent No. 3,161,938, since it has simple, low cost, wire supportfastener means that includes a pin portion that is inte grally secured with the remainder of the support-fastener to allow reinforcing strand means to be easily coupled and uncoupled quickly.

An object of my invention is to provide an efficient, low cost, wire support-fastener means having a pin portion that is integral with the remainder of the supportfastener means.

Another object of my invention is to provide an efficient curvable, elastic, flexible, plastic edge form strip that is able to accurately mold the edges of straight and curved, reinforced thin shell precast cementitious sections of various suitable widths, lengths and thicknesses, including tapered thicknesses; furthermore, to provide a simple low cost pin integral with a wire supportfastener means to position and prestress the reinforcing, also means to quickly and accurately position connectors that are on the ends of the reinforcing.

Other objects of my invention will become more apparent from the following description taken with the accompanying drawings wherein:

FIG. 1 is a fragmentary plan view showing flexible forms being used to mold a thin reinforced concrete section;

FIG. 2 is an enlarged, fragmentary sectional view taken along line 22 of FIG. 1;

FIG. 3 is an enlarged, fragmentary elevational View taken along line 33 of FIG. 1;

FIG. 4 is an enlarged, fragmentary, sectional View taken along lines 4-4 of FIGS. 1 and 3;

FIG. 5 is a fragmentary, sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a fragmentary, sectional view taken along line 66 of FIG. 3;

FIG. 7 is a fragmentary, sectional view taken along line 77 of FIG. 5;

FIG. 8 is a fragmentary plan view showing details of the spacer strand;

FIG. 9 is a fragmentary view similar to FIG. 4, showing a wire support-fastener;

Referring to the drawing, FIGS. 1 to 4 inclusive show assemblies F1 and F2 in an arrangement for molding precast, prestressed, reinforced concrete panel sections 1. The assemblies are stacked on the base form 2. Additional assemblies may be stacked above the assembly F2. My Patents No. 3,161,938 and No. 2,971,237 describe such assemblies and their use in detail. The assembly F1 would enclose a space before a panel 1 is formed in it. Each of the assemblies F1 and F2 has a flexible adjustable elastic and resilient plastic or rubber edge form strip 3. An assembly may be stripped of its form 3 so the panel 1 may be used as a building panel. An assembly may also be kept with its form 3 intact with the panel 1, so the assembly may be used as a form until the panel portion deteriorates from usage or is no longer needed as a form, then the panel 1 may be used as a building panel. The stacked casting means allows the molding of accurate duplications of an intricately curved panel surface such that of the base form 2 and apanel 1. A panel 1 for use as a portion of an additional form assembly may be molded on the form 2. The top surface of the panel 1 may be shaped with a screed or scraper.

When an original curved surface of the base form 2 is made, it may be duplicated in reverse by casting a female form on it, thus obtaining male and female forms which may be used to mold additional forms or building panels. The lower facing of a panel 1 is usable as a female form.

Intricately curved form assemblies with their elastic edging strips secured to the concrete panel form may be used as seed-like means to reproduce duplicate panel sections at a very low cost as compared to other casting methods.

The casting means shown causes the molding of identical curvatures to the surfaces of curved panel faces, except that the top surface of the panel is convex and the bottom surface is concave.

Form assemblies with their panel sections 1 kept intact may be kept in stacks so the assemblies are fastened together for safety and ease in handling as a unit during shipping and storage; furthermore, the forms 3 protect the fragile concrete edges and the reinforcing connections from being damaged. The form 3 also shields the panel edges from mud, ice, and other objectionable elements.

The base form 2 may be made of concrete, plaster, or other suitable materials. to it template bar forms 2b and the like. The template bars may be fastened together to form a frame. The base 2 is anchored to a base plate (not shown), which allows the casting means to be portable. The whole assembly may be suitably tilted, or be mounted vertically, while casting to insure against voids forming in the side surfaces of the concrete panels, by diverting air pockets to edges where they can be eliminated or be compensated for with grouting in the field joint.

The base form 2 has anchored.

Template bars 2b and the like may be anchored with bolt inserts 2g. The template bars 2b and the like have accurately spaced holes that are used to align and hold the wire support-fasteners 30 of the assembly F1 to the base 2. The template bars may be omitted if it is preferred to fasten the assembly F1 direct to the base 2, with bolts penetrating the base to hold the assembly.

The concrete for panel 1 of the assembly F1 can be poured within the confines of form 3 with the top surface of the panel being leveled with a screed, or the top surface may be molded by placing a completed assembly F2 on top of the assembly F1. When the top surface of a panel 1 is to be shaped with a screed, the top portion of the form 3 may be depressed with a frame formed with template bars.

The form 3 and supplementary metal parts can be positioned to allow them to be used to mold concrete panels of various widths and various lengths in multiples of eight inches or other suitable modular units, also in various curvatures as well as fiat shapes; furthermore, the panels can be molded in various thicknesses with the form 3. The form 3 may be compressed to taper it to allow it to mold a tapered panel. The form 3 may be compressed to allow a range of depths for molding panels of suitable thicknesses for thin shell building construction. For example, a form 3 with an unrestrained depth of two and a quarter inches that may be compressed to one and a half inches, would allow its use in molding a wide range of panels. Smaller and larger sized forms 3 may be made, such as smaller sizes for very thin type panels that are to be laminated.

There is accurate modular spacing means for spacing stiff embeddable reinforcing strand rods or wires 4. There are stiff connector means for connecting the reinforcing strands 4 to the pin portions 30a of the support-fasteners 30. A strand 4 has a connector welded to each end, the connectors being an eyelet or eye connector, like the eye shown in my Patent No. 3,161,938, on one end and a clevis connector 4b on the other end. The connectors provide a clevis-like pin connected interlocking means for joining building panels to each other at erection.

The connection of the strands 4 to the support-fasteners 30 allows tensioning of the reinforcing strands 4. All the ends of the strands 4 on one side edge and one end edge of a rectangular panel each have an eye. The ends of strands 4 on the other side edge and the other end edge of the panel each have a clevis 4b.

A modular unit is used for spacing the reinforcing strands 4 and for sizing of the panel. With this modular system, the reinforcing spacings are standardized for various types of construction on which it is to be used. Only a half module space is used from the corners of the panel 1 and the like to the first uniformly spaced reinforcing strand so that when erected, half module spaces on adjoining panels form a whole module space.

The edge form 3 is described fully in my Patents No. 2,971,237 and No. 3,161,938. Spaced holes 3g for the reinforcing strands 4 may be punched through the form 3. A slit 3 is cut from each hole 3g to the bottom of the form 3. Splicing means for a form assembly is described and shown in my Patent No. 2,971,237. The form 3 may have

longitudinal holes

30, 3d, and 3c. The form 3 may be made of elastic plastic that is stiff enough so the upper portion of the form will not sag from its own weight. The form 3 may be made of a more elas tic, weaker plastic that is reinforced with fabric or with spring steel wire 3k.

Most of the panel sections to be cast require keying grooves in all their edges, so that panels can be keyed together with mortar grout at the time of erection. The form 3 has a protruding medial portion which is the groove mold offset 3a.

The form 3 may have a retainer offset 3b, shown in FIGS. 2 and 3, to engage or catch against the spacer wires 5 and thus restrain the form 3 from tending to rise due to the lower portion of the form pressuring upwardly. The offset 3b would be particularly useful when the form 3 has slits 3f; the slits 3f would otherwise broaden and allow the'form 3 to rise unhampered by the reinforcing strands 4 and by the spacer strand M. The elastic form 3 may be stretched and compressed to pull it free of a semicured panel 1, spacer strand M, and reinforcing strands 4, without disturbing the pin 30a.

The form 3 with slits 3 and offset 3b may be positioned on strands 4 a distance from the support-fasteners 30, then be slid into the position shown in FIG. 2, thereby allowing the otfset 3b to be squeezed under the spacer wire 5.

The spacer wires 5 are attached to the splice bars 6 by welding or by other suitable means to form an accurate pliable metal spacing strand M. The spacer strand M is positioned along the full length of the form strip 3 at substantially the central portion of the form 3. The bars 6 are accurately spaced a module apart to match the spacing of the holes 3g in the form 3. My Patent No. 3,161,938 describes a spacer strand in detail. Panels of limited accuracy may be molded with forms 3 without the spacer strand M.

Since an eye is thinner than a clevis 4b, an adapter, like the adapter shown in my Patent No. 3,161,938, is slid onto an eye so the eye is positioned and aligned properly. The clevises 4b and eyes are shouldered due to the long stems or rectangular rod strand portions 4s being narrower than the main portions of the clevises and eyes, the wire 4 being welded to the stems. The strands 4s being strong resist forces caused by rough handling that tends to bend or twist the clevises and eyes out of alignment. The shoulders on the clevises and eyes are for allowing forked wedges to be driven between the cured concrete of the panel 1 and the main portions of these connectors to tension the strands 4.

When a semicured panel 1 is to be allowed to cure for a long period, the spacer strand M and the strip 3 may be pulled free so they may be used to mold other panels. The elasticity of the form 3 allows the form 3 to be stretched to permit it to be pulled free of the edging of the panel 1.

Pretensioning or so-called prestressing for use with this type of form means is described in my Patent No. 3,161,938.

The panels 1 may be made without prestressing the wires 4. Such panels would be suitable for much construction work, particularly when the panels are to be used in arch construction.

When curved wires 4, for a curved panel, are positioned above the base 2 or above the convex surface of a cured form panel 1, they may be supported by chairs, as described in my Patent No. 3,161,938.

The support-fasteners 30 are used to selectively gauge the effective depth of the form 3 and thus the thickness of the panel 1. The fasteners 30 restrain the form 3 from tilting. The support fasteners 30 align and support the assemblies F2 and the like that are above the assembly F1. The fastener 30 is fastened to the template bar 2b with a bolt 22 and a lock washer. A dowel 23 may also be used to position the fastener 30 to the template bar 2b. The dowel 23 is bolted to the fastener 30. A ridge on the stem of dowel 23 engages the underside of the fastener 30. Bolts 22 may be used to attach and align the fasteners 30 of the assembly F1 to the fasteners 30 of the assembly F2. Dowels 23 align the upper and lower fasteners 30. The pointed dowels 23 are selfcentering with the holes in the adjacent form assembly.

A wire support fastener 30 may be made of steel. The wire 30 is formed so as to provide means to perform functions that the more costly support fastener, described in my Patent No. 3,161,938, can perform. The surfaces of the wire 30 that contact each other may be welded together. A pin portion 30a is integral with the fastener 30. The fastener 30 has a bottom portion 3012 that is engageable with a base 2 or the like. The fastener 30 may have a top portion 300, which may be like the bottom portion 30b. The bottom 30b and the top 300 may be formed so as to provide an inner hole 30d and an outer hole 3tle in each portion. The holes 30d and 30:: may be used to .secure the fastener 30 to a base 2 or the like, also to like fasteners that may be positioned above and below it. The pin portion 30a is reinforced by the looped portion 30 that is bent around it. The looped portion 30 also acts as a seat for a clevis 4b or the like. The lower crimped portions 30g are an adjusting means to vary the height of the pin portion 300 above the bottom portion 30b. The crimps 30g may be squeezed towards each other with a pair of tongs to flatten the bends or crimps to an extent to cause the pin 30a to rise. The crimps 30g may be crimped to a greater degree with another tool to widen them to lower the pin 30a. The upper crimped portions 3012 may be squeezed towards each other to increase the overall height of the fastener 30. The crimps 36g may be crimped to a greater degree to spread them wider to decrease the overall height of the fastener 30. The diagonal arm portions 30k and 36m support the pin portion 30a. The

arm portions

30k and 30m may be bent with a tool, as shown in FIG. 9, to provide take-up means to tension the reinforcing 4. The clevis 4b on the reinforcing strand 4 may be forced onto the pin portion i'alla to cause the

arms

30k and 30m to be tensioned. The tensioning would stretch the

portions

30k and 30m, thus tending to straighten them. The wire used to make the fastener 30 may be made of steel that is hard enough to give limited spring action to at least the

arms

30k and 30m. The crimped portions 30g and 3011 and the adjacent portions of the bottom portion 30b and the top portion 30c may be nonresilient to allow the bottom portion 30b and the top portion 30c to be gripped with a tool and be twisted to tilt them so they can be made to bear against a warped or curved base 2 or the like.

A modified fastener (not shown) that is similar to fastener 30 may be made with pieces of Wire that are welded together and to plates that act as bottom and top portions.

Fasteners 30 allow self-uncoupling of a cured panel 1 from a form assembly F1 and the like. The panel 1 can be attached to a crane and be raised free of the form assembly without any need to manually disengage the pins from the clevises 4b or eyes. The form assembly P1 with a cured panel 1 engaged to it may overturned with a crane, causing the panel 1 to automatically uncouple itself by falling freely away from its engagement with the form assembly F1 and its pin means.

Wire mesh fabric may be used for reinforcing rather than wires 4, as described in my Patent No. 3,161,938. Reinforcing rod anchors are welded to the embeddable strand portions 4s of clevises 4b and eyes. The wire fabric may be stretched and be fastened to the anchors. Fiber glass may be embedded in the concrete for reinforcing and/ or insulation.

When the form assemblies are used to mold panels that are tapered in thickness, the form assemblies used to mold the top and bottom surfaces of the tapered panel are variably spread apart, the form 3 being depressed to a tapered shape. The fasteners 30 would be suitably adjusted to support the tilted form assemblies to maintain the selective variable thicknesses due to the tilting.

The fluid concrete for a panel 1 may be inserted into a form assembly by various means. The concrete may be inserted through the access holes that are cored in the panels 1. Concrete can be deposited within the confines of the form 3 of an assembly before a complete form assembly is used to cap the fluid concrete. The excess concrete is forced out of the holes 10. The holes 10 may also be used for inserting vibrators. An access 6 unit for inserting concrete through the elastic form means is described in my Patent No. 2,971,237.

In a typical joint of the interlocked panels like panel 1, a pin or bolt connects each eye to a clevis 4b. The panels 1 are keyed together with the grout mortar.

A panel similar to panel 1 may be molded with only a portion of the panel edging being molded with elastic form 3. The other portion of the panel edging may be molded by other suitable form means, including edges of like panels that are positioned alongside the space for molding a panel, so as to mold the edging.

Thus it will be seen that I have provided economical form means that is capable of performing a wide variety of operations to suit many conditions.

While I have illustrated and described several embodiments of my invention, it will be understood that these are by way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim:

1. A fastener for a form having an elastic edge for molding a thin cementitious panel having embeddable reinforcing strand means; said fastener consisting of a single metallic wire, said wire having a lower looped portion forming a base, said lower looped portion forming at least one hole for receiving a supporting element, said wire having a substantially vertical portion and an upper looped portion, said upper looped portion forming at least one hole, said wire having a portion offset from said vertical portion, said offset portion including a terminal portion of said wire, said terminal portion forming a pin, said pin being substantially parallel to said vertical portion, said terminal portion projecting outwardly away from the plane of said base, each of said embeddable reinforcing strand means having an end portion which includes an aperture, said pin accurately positioning said strand means end portion so that said aperture faces towards the planes of the major surfaces of said panel, whereby said strand means end portion may be quickly coupled to said pin and whereby said panel may be easily and quickly pulled away from and automatically uncoupled from said fastener without disturbing said pin.

2. A fastener as recited in claim 1, wherein said wire includes lower crimped means above said lower looped portion, said lower crimped means being pliable so that it may be flattened to an extent to raise said pin and may be bent more acutely to lower said pin, whereby said embeddable reinforcing strand can be variably positioned above said base and whereby said fastener can be varied in height.

3. A fastener as recited in claim 1, wherein said wire includes upper crimped means below said upper looped portion, said upper crimped means being pliable so that it may be flattened to an extent to raise said upper looped portion and may be bent more acutely to lower said upper looped portion, whereby said fastener may be varied in height while maintaining said pin a constant height above said base.

4. A fastener as recited in claim 1, wherein said wire includes a pliable portion adjacent to said lower looped portion, whereby said pliable portion may be bent to cause said lower looped portion to conform to the plane of said supporting element.

5. A fastener as recited in claim 1, wherein said wire having a second portion offset from said vertical portion, said second offset portion including a second terminal portion of said wire, said second terminal portion forming a substantial loop around a lower portion of said pin, thereby restraining said pin from moving objectionably and whereby said loop acts as a seat for an end portion of said embeddable reinforcing strand means.

6. A fastener as recited in claim 1, wherein said lower looped portion and said upper looped portion each have two holes, whereby said fastener may be securely restrained from pivoting laterally.

7. A fastener as recited in claim 2, wherein said wire includes upper crimped means below said upper looped portion, said upper crimped means being pliable so that it may be flattened to an extent to raise said upper looped portion and may be bent more acutely to lower said upper looped portion, whereby said fastener may be varied in height to a substantial degree.

8. A fastener as recited in claim 7, wherein said wire has a second portion offset from said vertical portion, said second offset portion including a second terminal portion of said wire, said second terminal portion forming a substantial loop around a lower portion of said pin, thereby restraining said pin from moving objectionably and whereby said loop acts as a seat for an end portion of said embeddable reinforcing strand.

9. A form for molding at least a portion of a thin cementitious building panel having stiff embeddable metal strand means spaced along at least the edging of said building panel portion, said form comprising an elongated elastic strip, a base for supporting said strip, said strip being sufiiciently rigid so as to prevent sagging of its top portion when supported on said base, said strip having an effective height substantially equal to the thickness of said building panel portion to be cast, said strip having a length at least sufficient to mold said edging of said building panel portion, said strip being sufficiently flexible so as to be bendable in all directions to allow it to follow the contours of curved and fiat planes, said strip confining the fresh cementitious aggregate of said building panel portion deposited onto said base and defining the shape of said edging, said strip having spaced transverse holes through an intermediate portion of its height and substantially parallel to the plane of the said base, said embeddable metal strand means having end portions extending through said holes, a plurality of fasteners disposed along the length of said strip for fastening said strip to said base and for anchoring the said end portions of said embeddable metal strand means, said end portions including connector means, each of said connector means including an aperture, each of said fasteners consisting of a single metallic wire, said wire having a lower looped portion forming a bottom, said lower looped portion forming at least one hole for receiving said base, said wire having a substantially vertical portion and an upper looped portion, said upper looped portion forming at least one hole, said wire having a portion otfset from said vertical position, said offset portion including a terminal portion of said wire, said terminal portion forming a pin, said pin beng substantially parallel to said vertical portion, said terminal portion projecting outwardly away from the plane of said base, said pins coupling said connector means, wherein said anchoring is provided, and wherein each of said pins accurately positioning one of said connector means so that said aperture faces towards the planes of the major surfaces of said panel, whereby said connector means may be quickly coupled to said pins and whereby said panel may be easily and quickly pulled away from and automatically uncoupled from said fasteners without disturbing said pins.

References Cited by the Examiner UNITED STATES PATENTS 2,323,705 7/1943 Cooper 25l3l 2,971,237 2/1961 Graham 251l8 3,161,938 12/1964 Graham 25-121 J. SPENCER OVERHOLSER, Primary Examiner.

WILLIAM J. STEPHENSON, Examiner.

Claims

1. A FASTENER FOR A FORM HAVING AN ELASTIC EDGE FOR MOLDING A THIN CEMENTITIOUS PANEL HVING EMBEDDABLE REINFORCING STRAND MEANS; SAID FASTENER CONSISTING OF A SINGLE METALLIC WIRE, SAID WIRE HAVING A LOWER LOOPED PORTION FORMING A BASE, SAID LOWER LOOPED PORTION FORMING AT LEAST ONE HOLE FOR RECEIVING A SUPPORTING ELEMENT, SAID WIRE HAVING A SUBSTANTIALLY VERTICAL PORTION AND AN UPPER LOOPED PORTION, SAID UPPER LOOPED PORTION FORMING AT LEAST ONE HOLE, SAID WIRE HAVING A PORTION OFFSET FROM SAID VERTICAL PORTION, SAID OFFSET PORTION INCLUDING A TERMINAL PORTION OF SAID WIRE, SAID TERMINAL PORTION FORMING A PIN, SAID PIN BEING SUBSTANTIALLY PARALLEL TO SAID VERTICAL PORTION SAID TERMINAL PORTION PROJECTING OUTWARDLY AWAY FROM THE PLANE OF SAID BASE, EACH OF SAID EMBEDDABLE REINFORCING STRAND MEANS HAVING AN END PORTION WHICH INCLUDES AN APERTURE, SAID PIN ACCURATELY POSITIONING SAID STRAND MEANS END PORTION SO THAT SAID APERTURE FACES TOWARDS THE PLANES OF THE MAJOR SURFACES OF SAID PANEL, WHEREBY SAID STRAND MEANS END PORTION MAY BE QUICKLY COUPLED TO SAID PIN AND WHEREBY SAID PANEL MAY BE EASILY AND QUICKLY PULLED AWAY FROM AND AUTOMATICALLY UNCOUPLED FROM SAID FASTENER WITHOUT DISTURBING SAID PIN.