GB1572758A

GB1572758A - Frame structure for casting building panels

Info

Publication number: GB1572758A
Application number: GB4648277A
Authority: GB
Original assignee: LEISURE LIFE; Leisure Life Inc
Current assignee: LEISURE LIFE; Leisure Life Inc
Priority date: 1976-11-11
Filing date: 1977-11-08
Publication date: 1980-08-06
Also published as: CA1071388A; DE2750075A1; GR64098B; NL7712446A; JPS5652732B2; BE860731A; JPS5386713A; IL53354A

Description

(54) FRAME STRUCTURE FOR CASTING BUILDING PANELS (71) We, LEISURE LIFE, INC., a Corporation organized under the laws of the State of Pennsylvania, United States of America of 301, South Allen Street, State College, Pennsylvania 16801, United States of America, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a frame structure for casting a concrete building panel.

In the building industry, and particularly the art of prefabricated concrete building structures, it has been known for some time that in order to avoid the cost of transporting rather large and heavy precast concrete panels from a central point at which they are manufactured in a casting plant to the site at which the building is to be erected, the panels could be cast on site. The method developed involves forming conventional wooden forms in the shape of generally rectangular frames corresponding to the shape of the concrete panel and laying one of these frames on a flat base and casting the panel within the wooden form. In order to conserve space, it has been proposed to cover such cast panel with a parting material, such as a sheet of plastics, then to cast a second panel on top of the first panel, and to continue thereafter to cast a series of panels in a stack.After the panels have cured, they can be unstacked and the wooden forms removed, and the panels can be incorporated into the building structure.

However, as the art of prefabricated concrete building structures has improved, methods have been developed for directly joining the edges of the panels to each other and filling the joints with a grouting material for sealing the joints, to facilitate the erection of the building. Such panels must have specially shaped edge portions in order to make it possible to join the panels together directly into the finished concrete building structure.

The method of precasting the panels at the site of the building structure has been difficult to adapt to the casting of such specially shaped panels.

It is an object of the present invention to provide a frame structure for casting a concrete building panel, preferably at the site of the building structure itself, which overcomes the drawbacks of the prior art.

It is a further object of the present invention to provide such a frame structure for casting a concrete panel which is light in weight and can therefore be easily and inexpensively transported to any building site, and yet which can be assembled in a way so as to cast a panel having any desired shape of the edge thereof.

It is still a further object of the invention to provide a frame structure for casting a concrete panel which is easy to use and can be easily handled by only two men in assembling the frame structure for the casting of a concrete panel.

It is a still further object of the present invention to provide the frame structure for casting the concrete building panel, the major portions of which can be reused again and again to cast concrete panels.

These objects are achieved according to the present invention by a frame structure for casting a concrete building panel, comprising a plurality of edge frame members each having a generally U-shaped cross-section assembled with a plurality of corner frame members having a configuration which, viewed in plan, corresponds to the angle of the corner of the panel to be cast; said edge frame members and said corner frame members being assembled with ends of the edge frame members abutting the corner frame members, and with the opening of the U-shaped cross-section of said edge frame members facing inwardly of the frame whereby the number of edge frame members along the sides of the frame structure determines the length of the corresponding sides of the panel to be cast; connecting means rigidly connecting said edge frame members and said corner frame members; and liner means in the interior of each of said edge frame members, said liner means having inner portions abutting the interior of said frame members for positioning said liner means in the frame members and surfaces facing the space within the frame which have a shape complementary to the shape of the edge of the panel to be cast by use of said frame structure.

The liner means may comprise liners molded in an easily mouldable material and inserted into said edge frame members and retained therein by retaining means within the members, or the liner means may comprise a coating of easily mouldable material softer than the material of the frame members and having varying thicknesses.

The same frames are used to carry out casting of stacks of panels as described hereinbefore.

The above and other preferred features of the invention will become further apparent from the following description of preferred embodiments of the invention, reference being made to the accompanying drawings, in which: Fig. 1 is a perspective view of an edge frame member forming part of the frame structure of a first embodiment of the present invention; Fig. 2 is sectional view of the frame member of Fig. 1; Fig. 3 is a perspective view of a liner for insertion into the frame member of Figs. 1 and 2; Fig. 4 is a sectional view similar to Fig. 2 with the liner in position in the frame member; Fig. 5 is exploded perspective view of a two-part liner showing the mating portions thereof; Fig. 6 is a perspective view of the opposite side of the liner of Fig. 3;; Fig. 7 is a perspective view of a corner frame member forming part of the frame structure of the first embodiment of the present invention; Fig. 8 is a perspective elevation view of portions of two frame members as shown in Fig. 1 stacked on each other and connected by stacking connecting means; Fig. 9 is a sectional view of a frame member with a liner therein and reinforcing rods locked in position therein; Fig. 10 is a fragmentary perspective view showing how the reinforcing rod of Fig. 9 is inserted into a recess in the liner; Fig. 11 is a perspective view of a liner attachment for forming an edge recess in a panel and attached to a frame member; Fig. 12 is a partial perspective view ot the frame structure in position on a base preparatory to the casting of a concrete building panel;; Figs. 13a, 13b and 13c are sectional views respectively of three forms of edge frame member forming part of a frame structure according to a second embodiment of the present invention; Fig. 14 is a front elevation view of part of the frame member of Fig. 13c; Fig. 15 is a section taken on line 15-15 of Fig. 13c; Fig. 16 is a perspective view of a stack of frame members of the type shown in Fig. 1 3a with the frame members in each layer being joined in end-to-end relationship; Fig. 17 is a view similar to Fig. 16 showing the frame members of the type shown in Fig.

1 3c in the different layers of the stack connected to frame members in layers thereabove and therebelow; Fig. 18 is a perspective view of frame members of the type shown in Fig. 13a connected at a corner of a panel frame by a corner structure; and Figs. 19a, 19b and 19c are views similar to Figs. 13a to 13c showing additional edge shaping members connected to the edge frame members.

The frame structure for casting a concrete building panel according to the present invention has, as the basic elements thereof, a plurality of edge frame members, a plurality of corner members, connecting means connecting the frame members together, and liner means in the edge frame members.

In the embodiment shown in Figs. 1 to 12, edge frame members 20 are shown in Figs. 1 and 2 and have a generally U-shaped crosssection defined by two sides 21 and 22 and a bottom 23. The sides have opposed inner surfaces 21a and 22a which are tapered outwardly toward the open part of the U-shaped cross-section. On the outer surface of the sides 21 and 22 are flats 24 which, when the frame members 20 are stacked one on the other as will be described in detail hereinafter, abut each other. A pointed rib 25, the purpose of which will be defined hereinafter, is provided along the inner surface of the bottom 23. A liner abutment means is provided within the frame member 20, and in the embodiment shown takes the form of an abutment 26 extending along the frame member between the bottom 23 and the side 21.

Liner retaining means in the inner portion of the U-shaped cross-section is here shown in the form of an inner channel portion 27 which has a slot-shaped opening 28 therein directed toward the open part of the U-shaped cross-section. The inner channel portion 27 is defined by a depending flange 27a having the lower end 27b bent inwardly into the interior of the channel portion 27, and an outwardly and upwardly projecting flange 27c having an inwardly turned edge 27d. The inwardly turned edges define the opposite sides of the slot 28. At intervals along the slot 28 are slot enlargements, as shown in 28a in Fig. 2, for a purpose to be described hereinbelow.

On the outside of the frame member 20 is an outer channel 29 having a slot 30 opening out of the channel 29. The edges of the frame member defining the slot 30 are turned inwardly at 29a and 29b.

It will be seen that the frame member 20 is thus in the shape of a channel member, and in this embodiment it is preferably an extruded aluminium channel member having a length of up to 14 feet. When extruded in a gauge having sufficient strength to support concrete in a panel having a thickness of 6", the 14 foot long frame member weighs approximately 110 pounds, which is easily handled by two men. Alternatively, other moulded or extruded metals can be used, or rigid moulded or extruded plastics materials, such as polyurethane resin, can be used.

In order to form the corners of the panels, corner frame members 31 are provided as shown in Fig. 7. The corner frame members each have two portions 3 1a and 31b which have the same cross-section as the edge frame members 20. These portions are abutted at one end thereof to each other and are attached to each other at an angle corresponding to the angle of the corner of the panel to be cast. In the specific form as shown in Fig. 6, the portions 3 1a and 3 1b are welded to each other to form a 900 corner.

It will thus be seen that the edge frame members and corner frame members can be assembled together to provide a frame as shown in Fig. 12, comprising a corner frame member 31 at each corner of the frame and one or more edge frame members 20 between each two adjacent corner frame members 31. In the specific frame shown in Fig.

12, the panel is to be rectangular, and there is a single edge frame member 20 extending across the short side of the frame between two adjacent corner frame members 31, and there are two edge frame members 20 extending in the direction of the long side of the frame between adjacent corner frame members 31. It will be obvious to those skilled in the art, however, that a square panel could be cast simply by making the number of edge frame members the same on each side of the frame, or other relative dimen sions could be obtained by inserting the requisite number of edge frame members 20 between adjacent corner frame members 31.

Moreover, the panels need not be rectangu lar, and corner frame members 31 having the portions 3 1a, 3 1b abutted at different angles could be used to form shapes such as triangu lar or hexagonal panel casting frames, and so on.

In order to join the edge frame members 20 to each other and to the corner frame members 31, connecting means is provided as shown in Figs. 2 and 7. The connecting means is constituted by a bar 3 3a which is positioned in the outer channel 29 over the inside of the slot 30 and a plate 33b positioned over the outside of the slot 30, and the bar and the plate extending between an abutting pair of frame members 20, or a frame member 20 and a portion of the abutting corner frame member 31, across the joint between the members. Threaded through the bar 33a and plate 33b in each of the abutting frame members on opposite sides of the joint is at least one threaded shaft 34 having a handle 35 thereon for rotating the shaft.It will be seen that by threading the shaft 34 through the bar 33a against the innermost surface of the channel 29, the bar 33a is forced against the inturned edges 29a and 29b, and the plate 33b is drawn tightly against the outside of the frame member, thus securely fixing the bar 3 3a and the plate 33b to the frame members 20, or the corner frame member 31. By fixing the bar 3 3a and plate 33b in both of the abutting frame members, the two frame members are secured together, and since the bar 33a substantially fills the channel 29, the abutting frame members will be substantially perfectly aligned with each other in the direction of the length of the frame members. A roller 34a around each shaft 34 enables the connecting means to move easily along the slot 30.

In order to hold frame members which have been stacked one on top of the other with the flats 24 on the upper frame member resting on the corresponding flats on the lower frame member, for purposes which will be discussed in greater detail hereafter, there is provided at intervals along the frame members and as shown in Figs. 8 and 12 a stacking connecting means in the form of a plate 36 having apertures therein spaced a distance equal to the distance between the channels 29 in frame members stacked one above the other. Threaded shafts 34 with handles 35 thereon are provided in each aperture and a bar like the bar 33a is provided in each channel 29.By passing the threaded shafts 34 through the apertures in the plate 36 into the bars 33a and by tightening the handles against the plate 36, the plate will be clamped to the outer surfaces of the upper and lower frame members, thus fixing the lower and upper frame members to each other.

In order to adjust the vertical positions of the frame members 20 relative to each other, it may be desirable to provide shims (not shown) between the frame members. In this case, additional holes must be provided in the plate 36, as will be readily apparent to those skilled in the art.

There is also preferably provided an anchoring means constituted by two angle plates 37a and 37b. Angle plate 37a has two vertically spaced holes therein each having a threaded shaft 34 with a handle 35 thereon extending therethrough. The upper shaft 34 extends through slot 30 into channel 29 where it engages in plate 33a as described above for the connecting means. The lower shaft 34 is threaded into a tapped hole in frame member 20. Angle plate 37b has one side secured, for example by rivets 37c, to the outwardly projecting portion of angle plate 37a, with the other side of plate 37b horizontal so that it can be secured by bolts, for example, to a supporting base.

Liner means is provided for each frame member 20 and, in this embodiment, for each corner frame member 31 also. As shown in Figs. 3 and 4, the liner means is in the form of a liner 40 having a shape providing surfaces 40a and 40b thereof which engage the inner surfaces 21a and 22a of the sides 21 and 22 of the frame members 20 and 31 which are substantially complementary to the surfaces 21a and 22a , i.e., which taper at substantially the same angle as the surfaces 40a and 40b. On the face of the liner 40 which is toward the innermost part of the frame member 20 or 31 is at least one projection 41 substanstantially aligned with an enlargement 28a in slot 28 in the inner channel portion 27, and tightly engaged in the slot enlargement 28a for retaining the liner 40 within the frame member.By placing the enlargements at intervals along the liner 40 corresponding to the intervals at which the enlargements 28a are located, the projections cooperate with the enlargements 28a both to retain the liner in the frame member and to locate the liner positively in the lengthwise direction relative to the frame member.

The liner 40 has a lower corner edge 42 which is shaped as shown in Figs. 3 and 4 to fit against the abutment 26 and limit the distance which the liner 40 can be inserted into the frame member. In addition, a projecting rib 42a along the lower portion of the face of the liner which faces the bottom 23 of the frame member 20 projects into the recess between the pointed rib 25 and side member 21 to further locate the liner 40 in the frame member 20.

It will thus be seen that the liner 40 is substantially wedged into the frame member 20, and retained therein by the engagement of the projection 41 in the slot enlargements 28a. The distance the liner 40, as shown, can move into the frame member 20 is limited by the abutment of the corner 42 with the abutment 26 and projecting rib 42a with the bottom 23. The liner 40 is thus securely positioned, and yet can be easily withdrawn in the direction of the open end of the U-shaped cross-section because the surfaces 21a and 22a and the complementary surfaces 40a and 40b are tapered outwardly toward this opening.

The liner 40 is preferably of a material which is softer than the material of the frame members, and most preferably is of expanded polystyrene. The liner can also be of so-called rubber polyurethane, either foamed or unfoamed. Such liners 40 can be easily moulded to the desired shape, and yet they are relatively inexpensive and extremely lightweight. They can thus be used as throw-away inserts for insertion into the frame member 20, and yet they are extremely easy to handle and to ship. In prac tice, where the liners are not protected from contact with the concrete, they can be used to cast one panel and then discarded. The frame members can be used over and over again.

Thus, for a complete building, there must be provided a complete set of liners, i.e., for all the edges of the panels. However, only enough frame members are needed to form for example three, four or five panels, and these are used over and over, as will be described hereinafter.

By making the material of the liner softer than the material of the frame member, which is preferably aluminium, the projections 41 can be made slightly larger than the width of the enlargements 28a, and the projections 41 are then slightly crushed as they are forced into the slot 28 so as to securely retain the liner 40 within the frame member.

The surface 43 of the liner 40 facing the space within the frame is shown in Figs. 4 and 6 as being substantially flat with projections 43a along the lower edge thereof, and the corresponding edge of the concrete panel will thus be substantially flat with corresponding recesses therein. However, the liner 40 can be formed so as to give the shape of the surface 43 any desired shape and the corresponding edge of the cast panel will then have a complementary shape. In addition, vertically extending recesses such as apertures 46 can be provided in the liner 40 into which the closed ends of loop-shaped reinforcing rods 44 can extend into the space within the frame, as shown in Figs. 6, 9 and 10. Preferably plugs 45 of rubber, plastics or the like, are placed on the reinforcing rods 44, as shown in Figs. 9 and 10, to plug the portion of the recess 46 not occupied by the rod 44 to block entry of concrete into the recess. The plugs 45 each have a body 45a and opposed cup-shaped flaps 45b on each end of the body which flaps co-operate to grasp the reinforcing rod 44 to position the plug thereon. With this arrangement, when the liners are removed from the cast panel, as will be described below, the loops of reinforcing rod will project from the edge of the panel. The reinforcing rod loops 44 are anchored by anchors 48 extending through corresponding apertures 47 in the bottom member 23 of the frame 20 or corresponding apertures 47 in the frame portions of the corner frame member 31 and recesses 46a in the liner 40 which intersect the recesses 46.

The anchors 48 each have a shank 49 with a hook 50 on the inner end which hooks into the looped reinforcing rod 44 in recess 46, the recess 46a being sufficiently large to accommodate hook 50. The other end of the shank has fastening means such as a nut 51 threaded thereon for drawing the hook 50 into tight engagement with the reinforcing rod 44 and drawing the reinforcing rod into the bottom of recess 46. Thus, the anchors 48, when they are tightened, hold the assembly of the frame member 20 or 31, the liner 40 and the reinforcing rod 44 together.

Moreover, gaps can be left between the liners 40, in which case the inner surface of the frame member will then serve as the form for the edge of the panel. In such a case, the projections 42a on the liner 40 on either side of the gap will extend to rib 25 and cooperate with the lower face of the rib 25 to form a relatively thin edge projection on the edge of the finished concrete panel.

In order to protect the surface 43 of the liner 40 which faces the inside of the frame member 20 and which will contact the concrete from the effects of the concrete and to keep the concrete out of contact with the aluminum of the frame members 20 and 31, there can be provided a protector 44, best shown in an exaggerated thickness, in Figs. 4 and 9. This protector is a sheet of plastics material, such as polyethylene, which has been moulded to a shape corresponding to the shape of the surface 43, that is with the projections 43a, or any other projections or recesses or the like present on the surface 43 and which has the ends 55a and 55b moulded in a shape for fitting snugly around the ends of the side members 21 and 22 of the frame members.The ends 55a and 55b extend back from the ends of the side members 21 and 22 at least to the rearmost flats 24 to protect the top and bottom surfaces of the frame members 20 and 31 from the concrete cast into the centre of the frame to form the panel. Preferably, the protector 55 has a groove 56 in the portion thereof just inside the end af the side member 21 for accommodating a strip of rubber or like sealing material which is held therein during the casting of the panel so as to provide a sealing gasket along the edge of the finished panel for engagement with the next adjacent panel in a finished building structure.

The liner 40 has been shown in Figs. 3,4,6 and 9 as being a single piece element, a single piece liner is very satisfactory. However, it is desirable for some purposes to change the position of the surface 43 of the liner so as to make it lie within the frame member 20 or 31 or so as to make it project beyond the ends of the side members 21 and 22 of the frame members 20 and 31. In order not to have to hold a large inventory of liners of various thicknesses, the liner can be made in two parts, as shown in Fig. 5, namely an inner (with respect to the bottom of the frame member 20) part 40y and an outer part 40z.

The inner part has recesses 60 in the outwardly facing surface 61 thereof, while the outer part 40z has complementary projections 62 on the inwardly facing surface 63 thereof for holding the parts in the proper relative positions within the frame member.

Naturally, the positions of the complementary recesses 60 and projections 62 can be reversed. In this way, a relatively small number of inner parts 40y can be provided, all the same size, and a large number of different sizes, particularly different thicknesses, of outer parts 40z can be provided so that the position of the outer surface 43 of the liner can be located at any one of several locations.

If it is desired to provide an edge recess in an edge of the panel, an edge recess form 65, as shown in Fig. 11, which has a shape complementary to the desired shape of the recess can be provided and can be secured to the frames 20 and 31 by a flexible trap 66 extending around the periphery of the form and having anchor elements 67 on the end thereof anchored in the inner channel portion 27. A simple T-shaped anchor element 67 will suffice, it simply being necessary to turn the T-shaped portion parallel to the slot 28 and insert it through the slot and allow it to turn perpendicular to the slot 28.

Thus, by the combination of the liner and the internal surface of the frame member, substantially any desired shape can be given to the edge of the cast panel. It requires only moulding of the liner 40 with the requisite shape of the surface 43, or providing apertures or gaps at proper places in the liner 40 or between the adjacent liners 40, for providing the requisite shape to the edge of the cast panel. It will be readily understood that indicator markings and matching markings can be provided on the edge of the cast concrete panel by providing appropriate shapes to the liner 40.

The frame members 20 and 31 can obviously have liners 40 therein, some of which have different shaped surfaces 43 from the others. Therefore, by providing an appropriate series of liners, a panel can be cast having the desired shape of the edge thereof for mating with any type of adjacent panels.

As shown in Fig. 12, after one panel P has been cast, a second set of frame members 20 and 31 is positioned on top of the frame members 20 and 31 for the first panel by stacking connecting means 36, with a parting sheet therebetween, for example of plastics, and after sufficient time has been allowed for the first panel P to set, the second panel can be cast. The frame members for casting the second panel are held in the proper position by the connecting means 36 as shown and described in connection with Fig. 8. After the first panel has set sufficiently so that it will maintain its shape and support the weight of another panel, the frame members 20 and 31 can be pulled laterally off the liners 40, leaving the liners 40 temporarily attached to the edges of the panels.The thus removed frame members can then be used for casting a third or fourth panel up in the stack in the same manner that the second or third panel is cast.

Beginning with the third panel in the stack and all those thereabove, the frame members on the last panel cast are supported on the reinforcing rods 44 embedded in the cast panel, and the frame members for the next panel to be cast will in turn be supported by the frame members for the past panel cast.

After the panels have completely set, they can be handled in the usual way by erecting into a concrete building structure. During the handling of these panels and up until they are placed in position, the liners can, if desired, be left attached to the panels, so as to prevent physical damage, such as chipping, to the edges thereof. Just before the panels are placed in their final position, the liners can be removed by simply pulling them off.

If the protectors are used, both the liners 40 and frame members 20 and 31 will be protected from the concrete. When the liners 40 are removed, the protectors can remain on the edges of the panel for temporary pro tection thereof and thereafter be discarded.

Thus, the interior surface of the frame members 20 and 31 do not become as dirty as conventional concrete forms. They are much easier to keep clean and in good condition for reuse, and can be used almost indefinitely.

Since frame members need not be cleaned extensively between uses, the recycling of the frame members for further casting opera tions can be carried out in an extremely short time as compared with conventional forms for use in casting concrete. Where the protec tors 55 are used, the liners 40 can also be reused a number of times, thereby reducing the size of the inventory of liners necessary for a given building structure.

If it is desired to cast a panel with a thick ness greater than that of the dimension of the frame members 20 and 31 in the direction of panel thickness, the shims mentioned hereinbefore can be provided between the stacked frame members, and appropriate means provided for preventing the concrete from escaping between the frame members Liners made of polystyrene can be cut to any desired length simply by using a hot wire.

It IS equally simple to form mitered corners for insertion into the corner frame members 31. Since all of the parts are interchangeable, the details of the edges of the panel can be chosen as desired and to meet extremely complex design requirements for abutting panels of concrete which have different functions in the completed concrete building structure.

Polystyrene liners are inexpensive and disposal thereof after they have been used a few times is not costly. A further advantage of leaving polystyrene liners or protectors on the edges of the panels after removal of the frame members is that, in addition to protecting the edges of the panels from physical damage, they slow the escape of moisture from the concrete, and further insulate the concrete from freezing during extremely cold weather.

If the liners are disposed of after a few uses, they do not become worn, and the edges of the cast panels are always given the proper form.

It is also possible, instead of removing the liners from the edges of the cast panels, to leave the expanded polystyrene liners in place in the finished concrete building structure in order to provide for thermal insulation, or to absorb certain structural deflections which may occur in floor and roof panels, for example.

The overall system from which the frames are made for a complete building structure not only occupies a relatively small space for purposes of shipping, but is relatively light in weight. In one practical embodiment of the invention, it has been found that the form system, including the frame members, liners, protectors and connecting bars, and the reinforcing and post-tensioning steel for a 20,000 square feet building can be packed and shipped in one Sea Land container.

Further, the cross-sectional shape of frame members 20 and 31 is such as to not only support and align liners 40, but also to cooperate with liners 40 having a variety of configurations to create an interaction between elements 20, 31 and 40 and thereby provide numerous concrete profiles necessary for the structural connections of the final concrete structure. In actual building practice, these profiles cannot be formed by either the frame elements 20 and 31 alone, or liner 40 alone.

It is only by the interaction of all these elements that a practical system of casting the panels is achieved.

In the use of the first embodiment, it is preferred that the edge frame members 20 be kept out of contact with the concrete being cast, so that in each instance a liner 40 will be inserted into the frame member and subsequently removed from the frame member when the frame structure is disassembled.

While this gives good flexibility insofar as using different shaped liners for making panels with different shaped edges, there is a tendency for the outsides of the frame members and the edges to have concrete adhere thereto, so that an inordinate amount of time is spent cleaning the frame members.

The structure can be modified to provide a different form of liner means which is permanently attached to the frame members, thereby reducing the number of parts necessary for forming a concrete building panel and reducing the amount of concrete adhering to the frames. A second embodiment of the invention in which the different form of liner means is used is shown in Figs. 13a and 19c.

Referring to Figs. 13a to 15, it will be seen that the edge frame member 120 has a generally U-shaped cross-section defined by two side members 121 and 122, and a bottom member 123. In the form shown in Fig. 13a the frame member is a single integral piece, while in the form shown in Fig. 13b, the frame member is made of three pieces welded together.

A liner means in the form of a coating 140 of a mouldable material which is relatively soft as compared to the material of the frame member 120 itself and which is resistant to attack by concrete, which is abrasion resistant and which is resistant to release agents for releasing concrete, is moulded over the outer surface of the side members 121 and 122, and the inner surface of the side members 121 and 122 and the bottom member 123. The coating 140 has a varying thickness for providing the surface 1 40a which faces the space within the frame with the desired shape, said shape being different from the shape of the interior surface of the frame member 120.For example, the coating 140 in Fig. 13a has a thick portion 140b along the inside of the bottom member 123 with a recess 140c at the lower part thereof, while the coating 140 in Fig. 13b has a thin portion 140d at the same location and no recess.

A preferred material for this coating is polyurethane having a hardness of about 80 Shore A and the coating 140 is bonded to the metal of the frame member by a conventional adhesive. The coating 140 is moulded to the frame member so as to provide flats 141 and 142 on the exterior surfaces of the side members 121 and 122, which flats, when the frame members 120 are stacked one on the other as will be described in detail hereinafter, abut each other. The inner surface of the coating 140 on the inner surface of side members 121 and 122 of Figs. 13a and 1 3b is tapered toward the opening of the frame.Mounted within the interior of the frame member 120 having the form shown in Fig. 1 3c is a filler 127 which extends from the outer end of the side member 122 downwardly and then inwardly where it joins the inner surface of the bottom member 123. In the specific arrangement shown, the frame member 120 and filler are made of extruded aluminium, the side member 122 and the filler 127 being formed as a single extrusion and permanently attached to the inner surface of the bottom member 123 of the frame member 120 by welding or the like. The other side member 121 can also be extruded separately and attached to the bottom member 123.

The inner surface of the filler 127 has a pair of upstanding webs 127b, the purpose of which will be described shortly. The lower surface 1 27a of the filler 127 is slightly tapered outwardly in the direction of the opened side of the frame member 120. The tapered surfaces facilitate removal of the edge of the concrete panel cast by the use of the frame members.

On the outside of the bottom member 123 of the channel member 120 is an outer channel 129 having a slot 130 opening out of the channel 129. The edges of the frame member defining the slot 130 are turned inwardly.

Along the upper outside corner of the frame member 120 is an upper groove 129c, and along the lower outside corner of the frame member is a lower groove 129d, the purpose of which will be described hereinafter.

In this embodiment, as in the first embodiment, the frame member is preferably an extruded aluminium channel member having a length of up to 14 feet, and having a gauge with sufficient strength to support concrete in a panel having a thickness of 6 inches.

Again other moulded or extruded metals or rigid moulded or extruded plastics materials can be used.

In order to form the corners of the panels, there are provided corner frame members 131, as shown in Fig. 18, which are simple boxes with a plane flat top 132 and depending plane flat walls (not visible in the drawing). When the corner frame member is in place between two edge frame members 120, the ends of the edge frame members are abutted against two adjacent walls of the corner frame member. The longitudinal dimensions of the side walls abutted by the edge frame members 120 are the same as the dimensions of the side members 121 and 122 of the edge frame members 120, so that when the corner frame member 131 is in position at the corner of a frame, the corner between the two walls of the corner frame member is at the intersection of the inner ends of the edge frame members.When the panel corners are right-angled corners, the corner frame member will be square, the outside walls thereof being the same size as the walls abutted by the ends of the edge frame members 120. However, if the corner is not a right angle, the corner frame member will have a quadrilateral shape with the two outer walls either both shorter than the abutted walls, where the corner angle is obtuse, or both longer than the abutted walls where the corner angle is acute.

In order to join the edge frame members 120 to each other and to the corner frame members 131, connecting means is provided as shown in Figs. 13a, 13b and 16 and is constituted by a pair of bars 161a and 161b which are L-shaped in cross-section, with one leg extending into the respective upper and lower grooves 129c and 129d, and with the other leg extending outwardly of the bottom member 123 of the frame member 120. Over the outer face of the bottom member 123 is a connecting plate 162 which has a series of bolts 163 along the upper and lower edges thereof, which bolts extend through the plate 162 and thread into tapped holes 161c in the bars 161a and 161b.It will be seen that the plate 162 is sufficiently long to extend over the joint J between two abutting ends of adjacent frame members 120, and that when the bolts 163 are tightened, the plate 162 and bars 161a and 161b will be clamped tightly to the bottom members 123 of the frame members 120 on opposite sides of the joint J.

In order to join the edge frame members 120 to the corner frame member 131, plates 162 and bars 161a and 161b are used to attach the plates 162 to the frame members 120. Holes are tapped in the outside side walls of the corner frame members 131 at appropriate places and bolts 132 are used to attach the ends of plates 162 to the outside side walls of the corner frame members 131.

An elongated aperture 164 is provided in each end portion of the plate 162 in alignment with the slot 130 opening out of the outer channel 129. The purpose of this groove will be described hereinafter.

In order to hold the frame members of frames which have been stacked one on top of the other with the flats 141 and 142 of the coating 140 abutting each other, as shown in Fig. 17, there is provided at intervals along the frame members 120 a stacking connecting means in the form of stacking plates 165 on each of the frame members 120 and vertically extending angle members 166 extending vertically between frame member 120 in the stack. Each of the plates 165 has a pair of grooves 165a in the face thereof extending transversely to the length of the frame member 120. Slots 165b open out of the grooves 165a.Bolts 167 extend through the ends of the plates, both at the top and bottom thereof, and thread into tapped holes in bars 161a and 161b which are identical to the corresponding bars in the connecting means for connecting the frame members 120 to each other described above in connection with Fig. 16. Thus, the bolts 167 and the bars 161a and 161b together clamp the plates 165 to the outside of the bottom members 123 of the frame members 120.

A clamping bar 168 is provided in each of the transversely extending grooves 165a, and one leg 166a of the angle member 166 has a projection 166b thereon which extends into the slot 165b. Bolts 169 extend through the one leg 166a of the angle member 166 into tapped holes (not shown) in the clamping bar 168, so that by tightening the bolts 169, the clamping bar 168 clamps the edges defining the slot 165a between the clamping bar and the one leg 166a of the angle member 166, thus securing the angle member 166 in a vertical position with respect to the horizontal frame members 120. By thus clamping the vertically extending angle member 166 to two superposed frame members 120, the frame members are connected to each other.

By spacing the grooves 165a along the face of the plates 165 properly, when one angle member 166 is used to connect a first and second superposed frame member 120, and a second angle member 166 is used to connect second and third superposed frame members, the other flange members of 166c of the angle members 166 abut each other at the position of the intermediate frame member, thus bracing the stacking connecting means against relative lateral movement of the frame members 120.

Since it is frequently necessary to have reinforcing rods in the concrete panels being cast, anchor means is also provided in the present embodiment for anchoring the ends of the reinforcing rods in the frame members.

As shown in Figs. 13c to 15, the fillers 127 have slots 1 27c therein at intervals therealong, and the looped ends of the reinforcing rods R are inserted into these slots to a position in which they project the desired amount above the inner surface of the filler 127. A hook member 180 of the desired length is provided within the space within the filler 127 having the shank end 180a extending through an aperture 123a in the bottom 123 of the frame member into the outer channel 129. The hook member 180 rests on the upper edges of the webs 127b on the outside of the filler 127. The hook member 180 is held in place by a retaining plate 181 urged against the inside face of the bottom 123 by a spring 182 held on the hook 180 by holding plate 183 attached to the hook 180 by a pin 183a. As seen in Figs. 14 and 15, a plurality of adjacent hooks of different lengths can be held by a single retaining plate 181 and a single holding plate 183. However, it is not necessary that groups of hooks 180 be provided. Single hooks and retaining plates, etc.

can be provided at intervals along the frame members 120.

The outer end of the shank 180a extends through an aperture 133b in a hook retaining bar 133a in the channel 129, and in a recess 133c in the bar 133a is provided a nut 134 threaded onto the threaded end of the shank 180a. Thus, the nut 134 can be tightened to draw the hook 180 toward the inner surface of the bottom 123 so as to increase the tension on the springs 182 and properly locate the hook 180.

The apertures 164 in the plates 162 are provided to give access to the nuts 134 threaded onto the ends of the hooks 180 so that adjustment can be made in the tension on the reinforcing rods by further tightening the nuts 134 while the frame members 120 are connected end-to-end, and while they are assembled in a vertical stack. Likewise, access can be gained to the nuts 134 for removing them so as to permit removal of the hooks when the frame member 120 is to be removed from the edge of the cast concrete panel. Thus, the plates 162 never need to be completely removed from the bars 16 1a and 161b, but can simply be loosened so that the assembly of the plates 162 and bars 161a and 16 1b can be slid along the length of the channels 120.

It will thus be seen that by providing the proper length of hooks 180 and properly positioning them within the interior of the filler 127, the reinforcing rods can be located at any desired position and held there.

A cover plate (not shown) should be provided which covers the bottom of each of the slots 172c which is not filled by the reinforcing rod R so as to block entry of concrete into the interior of the filler during casting of concrete.

It is believed that the manner of using the present embodiment will be clear from the description of the use of the first embodiment. The frame members 120 and 131 are assembled end-to-end in the desired shape of the panel, with the adjacent abutting frame members being connected by the plates 162 and bars 161a and 161b and bolts 163, and the reinforcing rods R are properly positioned as desired. The thus assembled frame is placed on a base, and the concrete is cast into the centre of the frame to form the desired panel in the same manner as described in connection with Fig. 12. The concrete will fill the space within the coating 140 within the frame member 120 so as to produce the desired shape of the edge of the concrete panel. In the present embodiment, where the frame members as shown in Fig.

1 3c are used and reinforcing rods are provided, the reinforcing rods will project out of a longitudinal recess along the edge of the finished concrete panel so that further rein forcing rods can be looped through the pro jecting reinforcing rods R to connect the edges of the panels to adjacent panels. After the first panel has been cast, a second frame is placed on the first frame, and the frames are connected in the manner as shown in Fig.

17 by the stacking connecting plates 165 and the angle members 166, and the second panel is cast. The third frame is assembled and connected to the second frame by the stacking connecting plates 165 and the angle members 166, and the third panel is cast.

Thereafter, the lower angle member 166 is removed from the first and second frames, and elevated, and a fourth frame is placed on top of the third frame and attached to the third frame by the thus raised angle member.

The panels are cast in sequence up the stack in this fashion.

After they have set sufficiently to be strong enough to handle, they are removed from the stack, and the frame members 120 are removed from the edges of the now completely cast panel simply by moving them off the edge of the panel. A release agent for releasing the concrete from the coating 140 can be placed on the coating 140 prior to casting. This makes it possible to keep the frame members quite clean. Since substantially no concrete will adhere to the coating, the frame member is ready for immediate use for casting further panels.

It is of course possible, as is the case with the first embodiment, to remove frame members from panels which have been cast in the lower portion of a stack of panels and which have set for use in casting new panels at the top of the stack.

It will be seen that in the present embodiment, the liner means, i.e., the coating 140, is not removed from the frame members and replaced with fresh liner means for casting further panels. Once the frame member is removed from the cast panel, it is immediately available for use in casting a new panel.

It will be seen from Figs. 13a to 13c that the shapes of the edges of the panels cast by the use of the frames described are limited to the cross-sectional shapes of the frame members 120 as shown in the figures. However, occasionally it is desired to have different shapes of the edges of the panels, or to provide recesses in the edges of the panels for the insertion of special structural elements in the finished concrete building structure. To make possible the provision of such shapes or recesses, the present embodiment of the invention provides plug-in elements which fit tightly into the frame members 120.

Referring to Figs. 1 9a to 19c, a first plug-in element 201 is shown in Fig. 19a for modifying the shape of the edge of the panel cast with the frame member of Fig. 13c. The plug-in element 201 has an L-shaped rigid extrusion 202 made, for example, of aluminium, which has the lower outside surface, the vertical outside surface and the top edge of the longer leg of the L coated with a mouldable material 203 which is preferably the same as the material of the coating 140 forming the lining means on the frame members 120.The dimension of the plug-in element 201 from the top to the bottom is such as to enable it to fit tightly into the smaller portion of the recess in the frame member 120 between the lower part of the filler 127 and the upper surface of the coating 140 on the side member 121 and be held there by friction between the coating 140 and the coating 203. The plug-in element 201 can extend the full length of the frame member 121, or it can be less than the length of the frame member 121, in which case end walls must be provided which fill the cross-section of the interior of the frame member between the plug-in element 201 and the bottom of the recess within the frame member.The panel cast with a frame member or members having one or more plug-in elements 201 therein will have an edge with a crosssectional shape like that of the space within the frame member 120 to the right of the plug-in member 201 in Fig. 19a.

Fig. 1 9b shows a similar plug-in element 211 for use with a frame member as shown in Figs. 13a or 13b. In this form of the plug-in element, the extrusion 212 is generally C-shaped, and the coating 213 on the outside surface thereof in turn has the outer surface with a shape complementary to the shape desired for the edge of the panel to be cast.

The top and bottom portions of the plug-in element 211 have recesses 214 in the coating 213 which are complementary to the shapes of the ends of the coating 140 where it extends around the ends of the side members 121 and 122 of the frame member 120. The dimensions of the plug-in element 211 between the recesses 214 are such that when the plug-in element 211 is inserted into the opening in a frame member 120 such as shown in Fig. 1 3a or 13b, the plug-in element is held in place by the frictional engagement between the material of the coating 140 and the material of coating 213.

The plug-in element 221 of Fig. 1 9c differs from that of Fig. 19b by the overall shape of the exterior surface thereof, and by the provision of a generally rectangular projection 225 moulded in the coating material 223 which extends along only a portion of the length of the plug-in element 221.

As with the plug-in element 201 of Fig.

19a, where the plug-in elements 211 and 221 of Figs. 1 9b and l 9c extend less than the full length of the frame member 120, end walls must be provided thereon.

WHAT WE CLAIM IS: 1. A frame structure for casting a concrete building panel, comprising a plurality of edge frame members each having a generally U-shaped cross-section assembled with a plurality of corner frame members each hav ing a configuration which, viewed in plan, corresponds to the angle of the corner of the panel to be cast; said edge frame members and said corner frame members being assembled with ends of the edge frame mem bers abutting the corner frame members, and with the opening of the U-shaped cross section of said edge frame members facing inwardly of the frame whereby the number of edge frame members along the sides of the frame structure determines the length of the corresponding sides of the panel to be cast; connecting means rigidly connecting said edge frame members and said corner frame members; and liner means in the interior of each of said edge frame members, said liner means having inner portions abutting the interior of said frame members for position ing said liner means in the frame members and surfaces facing the space within the frame which have a shape complementary to the shape of the edge of the panel to be cast by use of said frame structure.

2. A frame structure as claimed in claim 1 in which each said edge frame member has a liner retaining means in the interior thereof and each of said plurality of corner frame members has two portions having the same cross-section as said edge frame members and a liner retaining means in the interior of the member, said portions being abutted at one end thereof to each other and attached together at an angle corresponding to the angle of the corner of the panel to be cast, the ends of the edge frame members in said panel moulding frame are aligned with and abut the other ends of the portions of the corner frame members, and said liner means are liners engaged with liner retaining means in said frame members.

3. A frame structure as claimed in claim 2 in which said liner retaining means in each frame member comprises an inner channel portion in the innermost portion of the interior of said U-shaped cross-section and extending along the length of the frame member and having a slot-shaped opening therein directed toward the open part of said U-shaped cross-section, and said liners each have at least one projection thereon engaged in said slot-shaped opening for retaining the liners in said frame members.

4. A frame structure as claimed in claim 3 in which said liners are of a material which is softer than the material of the frame mem bers and said projections are slightly larger than the width of said slot-shaped openings and are forcibly engaged in said slot-shaped openings for retaining the liners in the frame members.

5. A frame structure as claimed in claim 3 in which the inner channel portion in each frame member has a plurality of pairs of opposed recesses spaced along the edges defining said slot-shaped opening to form slot enlargements, and said liners each have projections spaced at distances therealong corresponding to the spacing of said slot enlargements and of a size for fitting tightly into said enlargements, whereby the liners are properly located along the frame mem bers.

6. A frame structure as claimed in claim 2 in which the surfaces of at least some of the liners facing the space within the panel moulding have a shape which is different from the shape of the corresponding surface

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. extend the full length of the frame member 121, or it can be less than the length of the frame member 121, in which case end walls must be provided which fill the cross-section of the interior of the frame member between the plug-in element 201 and the bottom of the recess within the frame member. The panel cast with a frame member or members having one or more plug-in elements 201 therein will have an edge with a crosssectional shape like that of the space within the frame member 120 to the right of the plug-in member 201 in Fig. 19a. Fig. 1 9b shows a similar plug-in element 211 for use with a frame member as shown in Figs. 13a or 13b. In this form of the plug-in element, the extrusion 212 is generally C-shaped, and the coating 213 on the outside surface thereof in turn has the outer surface with a shape complementary to the shape desired for the edge of the panel to be cast. The top and bottom portions of the plug-in element 211 have recesses 214 in the coating 213 which are complementary to the shapes of the ends of the coating 140 where it extends around the ends of the side members 121 and 122 of the frame member 120. The dimensions of the plug-in element 211 between the recesses 214 are such that when the plug-in element 211 is inserted into the opening in a frame member 120 such as shown in Fig. 1 3a or 13b, the plug-in element is held in place by the frictional engagement between the material of the coating 140 and the material of coating 213. The plug-in element 221 of Fig. 1 9c differs from that of Fig. 19b by the overall shape of the exterior surface thereof, and by the provision of a generally rectangular projection 225 moulded in the coating material 223 which extends along only a portion of the length of the plug-in element 221. As with the plug-in element 201 of Fig. 19a, where the plug-in elements 211 and 221 of Figs. 1 9b and l 9c extend less than the full length of the frame member 120, end walls must be provided thereon. WHAT WE CLAIM IS:

1. A frame structure for casting a concrete building panel, comprising a plurality of edge frame members each having a generally U-shaped cross-section assembled with a plurality of corner frame members each hav ing a configuration which, viewed in plan, corresponds to the angle of the corner of the panel to be cast; said edge frame members and said corner frame members being assembled with ends of the edge frame mem bers abutting the corner frame members, and with the opening of the U-shaped cross section of said edge frame members facing inwardly of the frame whereby the number of edge frame members along the sides of the frame structure determines the length of the corresponding sides of the panel to be cast; connecting means rigidly connecting said edge frame members and said corner frame members; and liner means in the interior of each of said edge frame members, said liner means having inner portions abutting the interior of said frame members for position ing said liner means in the frame members and surfaces facing the space within the frame which have a shape complementary to the shape of the edge of the panel to be cast by use of said frame structure.

on the other liners.

7. A frame structure as claimed in claim 2 in which the liners each have a shape with the surfaces thereof engaging the sides of the U-shaped cross-sectional frame members substantially complementary to the sides of the interior of the U-shaped cross-section frame members.

8. A frame structure as claimed in claim 7 in which the opposed inner surfaces of the sides of the U-shaped cross-section of the frame members are tapered outwardly toward the open part of the U-shaped crosssection.

9. A frame structure as claimed in any one of claims 2 to 8 in which said liners are a relatively soft easily mouldable material.

10. A frame structure as claimed in claim 9 in which said liners are expanded polystyrene, rubber polyurethane or foamed polyurethane.

11. A frame structure as claimed in claim 10 in which at least some of said liners are one-piece liners.

12. A frame structure as claimed in claim 10 in which at least some of said liners are in two parts and comprise an inner part for fitting into the inner part of a frame member and an outer part having the surface facing the space within the frame members, said parts having mating projections and recesses for holding the parts in the proper relative engaged positions.

13. A frame structure as claimed in any one of claims 2 to 12 in which the outer surfaces of the sides of the U-shaped crosssectional frame members have flats thereon for abutting corresponding flats of adjacent frame members when the frames are stacked.

14. A frame structure as claimed in any one of claims 2 to 13 in which said frame members are extruded aluminium.

15. A frame structure as claimed in any one of claims 2 to 14 in which each frame member has an outer channel therealong having a slot opening out of said outer channel, and said connecting means for connecting each two adjacent frame members comprises a bar positioned in said outer channel and extending between adjacent frame members, a plate along the outside of said frame members, and connecting members on opposite sides of the joint between adjacent frame members and extending through said plate, said slot and bar for drawing said plate and said bar toward each other to clamp said frame members therebetween.

16. A frame structure as claimed in claim 15 in which said connecting members each comprise a threaded shaft threaded through said bar for drawing said bar against the outer wall of the interior of said channel on opposite sides of said slot, and a handle on the shaft bearing against the outside of said plate.

17. A frame structure as claimed in claim 2 further comprising stacking connecting means for connecting a plurality of said frames in a stack one above the other.

18. A frame structure as claimed in claim 17 in which each frame member has an outer channel therealong on the outer surface of the bottom of the U-shaped cross-section and having a slot opening out of said outer channel, and said stacking connecting means comprises a plate extending transversely of at least two frame members, a bar in the outer channel of each frame member, and threaded means connected to said plate and to said bars for clamping said plate to said frame members.

19. A frame structure as claimed in claim 18 in which said threaded means is a threaded shaft extending through said plate and threaded through each bar for drawing said bars against the outer wall of the interior of said outer channel on opposite sides of said slot in each frame member, and a handle on each threaded shaft for urging said plate against the frame members over said slots.

20. A frame structure as claimed in any one of claims 2 to 19 in which said frame members and liners have recesses therein for the insertion thereinto of reinforcing rods to be held by said frame structure and be cast into the panel.

21. A frame structure as claimed in claim 20 further comprising anchors extending through said frame members and said liners for engaging the reinforcing rods for holding said reinforcing rods in said liners.

22. A frame structure as claimed in claim 21 in which said anchors are arranged to engage horizontally oriented U-shaped reinforcing rods with the U-shaped end in the respective recesses of the liners, and said anchors are each constituted by a shank having a hook on one end for engagement with the U-shaped end of the associated reinforcing rod and means on the other end for engaging the frame member in which the anchor is located for pulling the reinforcing rod snugly into the associated recess and securing the associated reinforcing rod, liner and frame member tightly together.

23. A frame structure as claimed in claim 22 further comprising a plug for engagement between the legs of each U-shaped reinforcing rod, said plug having portions for engaging around the legs of the rod and having an overall shape complementary to the crosssection of the reinforcing rod receiving recesses in the liners for plugging each of said recesses when a reinforcing rod is positioned therein for preventing concrete from flowing into the recesses during the casting of the concrete panel.

24. A frame structure as claimed in any one of claims 2 to 23, further comprising a recess form member engaged with a liner and extending into the space within the frame, and a strap extending around said recess form member and having the ends thereof engaged in said liner retaining means in the frame member from which the recess form member extends.

25. A frame structure as claimed in any one of claims 2 to 24 further comprising a protector for at least some of the frame members and liners of said frame structure, said protector comprising sheet material positioned over the surface of the liners facing the space within the frame with the ends of said sheet extending along the outer surfaces of said frame members.

26. A frame structure as claimed in claim 25 in which each said protector has a groove therein facing the space within the frame with which it is associated for receiving a strip-shaped gasket to be moulded into the edge of the concrete panel.

27. A frame structure as claimed in claim 1 in which said liner means in each edge frame member comprises a coating of a mouldable material softer than the material of the frame members and having a varying thickness for providing the desired shape to the surface of the liner means facing the space within the frame, which shape is different from the shape of the interior surface of the edge frame member.

28. A frame structure as claimed in claim 27 in which the surfaces of at least some of the coatings facing the space within the frame have a shape which is different from the shape of the corresponding surfaces on other coatings.

29. A frame structure as claimed in claim 27 in which the opposed inner surfaces of the side members of the U-shaped cross-section of the edge frame members and the coatings thereon are tapered outwardly toward the open part of the U-shapXed cross-section.

30. A frame structure as claimed in claim 27 in which the material of the coating extends around the ends of the side members of the U-shaped cross-section of the edge frame members and along the outside surfaces of said side members.

31. A frame structure as claimed in claim 30 in which part of the coating on the outside surfaces of said side members has a thickened portion with a flat outer surface for abutting a corresponding flat surface on an edge frame member which lies against the flat outer surface.

32. A frame structure as claimed in any one of claims 27 to 31 in which said edge frame members are extruded aluminium.

33. A frame structure as claimed in any one of claims 27 to 31 in which said coating material is polyurethane adhered to said edge frame member.

34. A frame structure as claimed in any one of claims 27 to 31 in which each frame member has a groove along the upper and lower outer corners thereof, and said connecting means for connecting each two adjacent frame members comprises two bars of L-shaped cross-section with one leg in a corresponding groove in adjacent frame members, and a plate extending along the outside of said frame members, and connecting members along the edges of said plate opposite said bars and extending through said plate into said bars for drawing said plate and said bars toward each other for clamping said frame members therebetween.

35. A frame structure as claimed in claim 27 in which said corner frame members each comprise a plate member and depending side walls depending therefrom and abutting the ends of edge frame members at the corners of the frame.

36. A frame structure as claimed in claim 35 in which said corner frame members each further have depending side walls along the outside of the corner frame member flush with the outside surfaces of the bottom members of the abutting edge frame members, and said edge frame members each have a groove along the upper and lower outer corners thereof, and said connecting means for connecting adjacent frame members comprises two L-shaped cross-section bars with one leg in a corresponding groove in an edge frame member abutting in corner frame member, a plate extending along the outside of the adjacent frame members, and connecting members along the edges of the plate opposite said bars and extending through said plate into said bars for drawing said plate and said bars toward each other for clamping the edge frame member therebetween, and further connecting members extending through said plate for securing said plate to said outside depending side walls of said corner frame member.

37. A frame structure as claimed in any of claims 27 to 36 further comprising stacking connecting means for connecting a plurality of frames in a stack one above the other.

38. A frame structure as claimed in claim 37 in which each edge frame member has a groove along the upper and lower outer corners thereof, and said stacking connecting means comprise a plurality of bars of L-shaped cross-section with one leg in corresponding grooves in the edge frame members in the stack, a stacking plate on the outside of each of the edge frame members in the stack, connecting members along the edges of said stacking plates opposite said bars and extending through said plates into said bars for drawing said plates and bars toward each other for clamping the edge frame members therebetween, said stacking plates each having a pair of spaced parallel grooves therein extending in a direction of stacking of the frame members, each groove having a slot opening out of the groove which is narrower than the groove, a bar in each groove, the bar in one groove extending through the corresponding groove in the stacking plate on the next higher edge frame member in the stack and the bar in the other groove extending through the corresponding groove in the stacking plate on the next lower edge frame member in the stack, a pair of angle members, one angle member having one flange over the slots of the grooves in which one bar is positioned, and the other angle member having one flange over the slots of the grooves in which the other bar is positioned, and connecting means extending through said one flange on each angle member into the corresponding bar for drawing said bars and flanges toward each other to clamp said stacking plates therebetween, the angle members having second flanges thereon which abut each other for resisting relative lateral movement of said edge frame means to which said stacking connecting means is connected.

39. A frame structure as claimed in any one of claims 27 to 38 in which said liner means further comprises a filler member extending between one of said side members of at least one of said U-shaped cross-section edge frame members and the bottom member thereof with said coating over the surface thereof within said edge frame member, said filler member defining a closed space between said filler member and the inner surface of said edge frame member, and anchors extending into said closed space through said frame member for engaging reinforcing rods for holding reinforcing rods in position in said frame during casting of a concrete panel therein.

40. A frame structure as claimed in claim 39 in which said anchors are arranged for engaging horizontally oriented U-shaped reinforcing rods with the U-shaped end in the closed space, said filler has at least one slot therein through which the reinforcing rod extends, and said anchors are each constituted by a shank having a hook on one end for engagement with the U-shaped end of the associated reinforcing rod and means on the other end for engaging the frame member in which the anchor is located for pulling the reinforcing rod snugly into the closed space and securing the associated reinforcing rod and frame member tightly together.

41. A frame structure as claimed in any one of claims 27 to 41 further comprising a plug-in member for at least one of said edge frame members, said plug-in member being rigid and having a coating thereon of the same material of the coating forming said liner means and having a dimension for fitting tightly into the space within said edge frame member with the surface thereof facing the interior of the frame having the desired shape complementary to the shape of the edge of the panel to be cast by the frame structure.

42. A frame structure as claimed in claim 27 in which said edge frame members each have a bottom member and two separate side members, the side members being connected to the bottom member.

43. A frame structure as claimed in claim 27 in which said edge frame members each have a bottom member and two side members formed of a single piece of material.

44. A frame structure for casting a concrete building panel substantially as hereinbefore described with reference to Figures 1 to 12 or Figures 1 3a to 1 9c of the accompanying drawings.