US 3866371 A
A structural framing system for building low-cost easily-assembled enclosures comprising a connector and a beam which have a unique tongue and groove connection. The connector also has a transverse slot and an aperture. Two connectors fit together at their slots, the apertures are aligned, and a spindle part of a column is inserted through the aligned apertures to form a three-dimensional joint. The beam is then connected to anyone of the ends of the connectors and in that way further beams, connectors, and columns are added so as to form the desired structural framing system.
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Description (OCR text may contain errors)
United States Patent i191 Falconer [4 1 Feb. 18,1975
[ STRUCTURAL FRAMING SYSTEM  Assignee: Midwest Housing Research Corporation, Jefferson City, Mo.
 Filed: Mar. 7, 1973  Appl. No.: 338,663
2,010,874 8/1935 Matheny 52/648 2,712,199 7/1955 Latimer 52/752 3,206,903 9/1965 Johnson 52/648 Primary Examiner-Frank L. Abbott Assistant E.raminer--James L. Ridgill. Jr. Attorney, Agent, or FirmHolman & Stern  ABSTRACT A structural framing system for building low-cost easily-assembled enclosures comprising a connector and a beam which have a unique tongue and groove connection. The connector also has a transverse slot and an aperture. Two connectors. fit together at their slots, the apertures are aligned, and a spindle part of a col umn is inserted through the aligned apertures to form a three-dimensional joint. The beam is then connected to anyone of the ends of the connectors and in that way further beams, connectors, and columns are added so as to form the desired structural framing systern.
7 Claims, 9 Drawing Figures STRUCTURAL FRAMING SYSTEM BACKGROUND OF THE INVENTION The instant invention deals with a structural framing system which is easy to assemble and of low cost.
According to recent housing census data, better than two thirds of the substandard housing in the United States is found outside the metropolitan areas. These areas are normally called rural or urbanizing-rural areas. Studies have shown that the typical small home builder in these areas cannot build at profits which attract him to low to moderate income housing. Moreover, such rural areas are less likely to benefit from industrialized building technology because of logistics and density of housing, noting that the per-unit price decreases as the number of units to be simultaneously built is increased. The distribution of manufactured housing is perhaps the greatest single drawback to lowering the cost of such lowto moderate-income housing. A typical small manufacturer of modular homes usually finds its economic delivery radius is 200 miles or less.
The prior art suggests that low-cost rural housing can be built using small modular components which are specifically designed to be easily and cheaply transported and try to reduce the time and skills required for on-site assembly. Such packaged component systems exist, however, they trade off savings in shipping costs against the greater reliance on local labor to assemble these small component parts at the site, which tends to cancel out the economic advantage.
The present trends in the building industry appear to be directed towards off-site manufactured housing which is not likely to benefit those living in rural areas since the disaggregated character of the rural market and other factors obstruct the marketability and distribution of the factory-fabricated modules.
Another problem long experienced in low-income housing in the rural area, and for that matter lowincome housing in any environment, is the lack of participation of the lower-income family in the houseplanning and design. Such a family has little choice except between one stock plan or another. In a do-ityourself house, conventional building techniques prevent all but those skilled in such techniques from building their own house in accordance with their personalized plans and designs. Rationalized and simplified building methods and techniques would increase the number of people capable of building their own house and thereby increase the amount of choice such lowincome people have in their housing.
SUMMARY OF THE INVENTION It is an object of the instant invention to overcome the above-mentioned problems and to provide a structural framing system which is standardized and simple, thereby making it possible for small local builders to construct housing on-site at reduced cost and increase the opportunity of the home-owner to participate in the planning process. The structural framing system is basically made up of three components, a beam, a connector, and a column. The beam and the connector both have stepped profiles, there being a reduced height end-portion at either end. A groove extends along the longitudinal length of the end-portion, preferably vertically through the entire height of the beam. The full height section has a portion of it adjacent each reduced height portion, which has a reduced width, the width being equal to the width of the groove. The connector also has a transverse vertical slot extending from the level of the reduced height end-portion through the reduced width portion, which slot has a longitudinal width equal to the full width of the connector. There is an aperture extending vertically from the slot through the full width portion. The column is an elongated member having a smaller cross-sectional end-portion which is called a spindle.
Two connectors transversely fit together so that the slot of one fits over the full width section of the other and vice-versa. The apertures of each connector are aligned and the spindle of the column fits through the aligned apertures so that the lower-most connector is supported by a ledge where the column changes a cross-sectional area. It will be seen that in this way, a three-dimensional joint has been formed, the column being adapted to be placed vertical and the two transverse connectors horizontally extending in four different directions. A beam is then connected to anyone or all of the ends of the connectors in a way to be hereinafter explained, and when a change of direction is desired, another pair of connectors is introduced into the system along with a column. In this way, a complete structural framing system can be simply and economically formed.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. FIG. FIG. FIG. FIG.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 through 3 show a beam of the instant structural framing system, which beam is uniquely constructed so as to be quickly and simply joinable to either another beam or a connector. The beam 10 has an end-portion 11, which end-portion preferably has a groove 12 extending through its entire height as seen in FIG. 2. It is possible that the groove need only extend through the major portion of the height of the endportion so as to show a solid longitudinal edge, as opposed to a channel as seen in FIG. 3. A core 13 has a reduced width as best seen in FIG. 3, which width is equal to the width of groove 12. There is a full width middle section 15 the periphery of which defines the outward shape of the beams when they are connected together. FIG. 1 best shows that the beam has a stepped profile in side-elevation, having a full height middle section 15 and reduced height end portions 11. Preferably, beam 10 has a channel down the center of either longitudinal edge, as explained above, it is possible for the edge not to have the channel especially when the beam is to be exposed in the house for aesthetic purposes, or is to be nailed into etc.
FIGS. 4 through 6 show a connector 20 which has an I end-portion 21 having a vertically extending groove 22 in it. This groove longitudinally extends from the core 23 to the end of the connector, and preferably extends the full height of end-portion 21. In the middle of the connector 20, there is a transverse slot 25 which extends from the level of the reduced height end-portion 21 through the core 23. Core 23 is of a reduced width as best seen in FIGS. and 6, and this reduced width is equal to the width of groove 22. The longitudinal width of slot 25 is equal to the full width of the connector. There is an aperture 26 in the center of the connector extending from the slot 25 to the opposite edge of the connector. Preferably there is a channel 24 running along one edge of the connector, but it is possible for this longitudinal edge to be flush and dispense with the channel 24. FIG. 4 best shows that the connector also has a stepped profile in side elevation, having a full height middle section 23 and reduced height end portions 21.
FIG. 7 shows a column 30 which is made up of a large cross-sectional portion 31 and a reduced crosssectional spindle 32. The junction of the large and small cross-sectional portions forms a ledge 33. The cross-sectional area and shape of spindle 32 corresponds with aperture 26, preferably square in crosssection.
The three elements above explained, namely the beam, the connector and the column, fit together to form a rigid three-dimensional joint as best seen in FIG. 8. Two connectors are transversely joined one to the other in such a way that the slot 25 of one fits into the slot of the other and over the full width portion of the other connector remembering, that the width of the slots is equal to the full width of the connector. The holes 26 are aligned and the spindle 32 is introduced through the aligned holes so that the bottom-most connector rests on the ledge 33. To extend any one of the connectors in a longitudinal direction a beam is placed on the connector as seen in FIG. 8 so that the end-portion ll of the beam 10 fits onto and over the core 23 of the connector, and the core 13 of the beam fits into the groove 22 of the connector. Once these elements have been frictionally fit together, noting that their dimensions are such that they will only properly fit in a given orientation, the connection is made permanent by an adhesive, nails, bolts pegging, or a combination of any of the foregoing. The structural framing system can be extended until a junction is desired, or within the structural limits of the material, at which point another pair of connectors is assembled onto a column.
The beams preferably come in three uniform lengths. 6 foot 6 inches, 9 foot 9 inches, and 13 foot 0 inches. The connector is preferably 6 foot 3 inches long and it will be therefore seen that at the corner of a building there is a built-in cantilever of three foot provided by the connectors, and onto which a roofloverhang, or at lower level a sun-deck can be provided. With the threesize beams, rooms of various incremental dimensions made up of combinations of the length of the beams can be made at will. It should be noted that the structural frame system is an open system and therefore does not dictate the final form of the house since it can accept any number of roof or wall sub-systems. These can be either built at the site, or prefabricated. Since the main structural frame system is designed to carry dead and live building loads, the enclosing wall subsystem need not duplicate this capability which, therefore, can allow a dramatic decrease in cost. The wall sub-systems can be the conventional stud-type, an assembly of panels, prefabricated off-site, or made of sheets of structurally stable material onto which a thermosetting plastic foam or other plastic material is either 'trowelled or sprayed.
The structural framing system is extremely adaptable and can be placed on concrete or masonry piers, on a crawl-space or a basement wall, or on a slab-on-grade. In the case of the first two, the houses would have floors supported on the beams, and in the case of the last one, the concrete slab would form the floor.
As far as the material used for making the beam, connector, or column, preferably 54-inch plywood is used. Looking at FIGS. 1 through 6, it will be seen that two outer sheets of plywood run the length of the beam or connector. The cores are made up of two laminated sheets of ii-inch plywood thereby making a core having a thickness of 1% inch. The full width of either the beam or connector would be three inches, the combination of four fli-inch plywood sheets. Plywood is utilized because of its immediate availability, large strength to weight ratio, and relatively low cost. Moreover, plywood, pressed paper products, for example, Homasote or fiberboards can be used with alternating layers of reinforced plastic, such as fiberglass. Use of sandwiched honeycomb structure is also possible and the choice will basically be made on economics and may be overridden by the particular use that the framing system will be put to.
Since the connectors and beams preferably have longitudinal channels along their edges, it is possible to have wallpanels of a thickness commensurate with the width of the channels, so that those wall panels fit into the channels. It can easily be seen that such a simplified method of enclosing would dramatically lower the cost whether the panels were used as dividing partitions within the dimensions of the structure, or as outside walls of the structure. It is possible to spray or trowel thermosetting foams or other plastic materials on the panels making up either the outside or the inside partitions, noting that the polymeric foams possess excellent thermal and and acoustic properties. Moreover, the foams would be applied after the panels are in position and when they set the foam would achieve stiffness and increase the strength and resistance to mechanical damage with a very small increase in weight. It is possible to generate foams on-site and apply these foams directly to the shell or the frame of the building thus creating an enclosing envelope which would greatly reduce the problem of joints between panels. It is possible as well to apply foam to the roof, either on properly sloped panels or onto a sub-structure with the proper pitch.
What is claimed is:
1. Construction means for building low-cost easily assembled structures having joints with structural continuity and stiffness comprising: at least one beam having a stepped profile in side elevation, the middle being a full height section and at least one end portion being of reduced height, a groove extending vertically through the entire height of the end portion and longitudinally from said at least one end to the beginning of said full height section, the middle portion of the full height section being full width, and there being at least one reduced width portion longitudinally extending from said full width middle portion to the reduced height end portion; and at least two connectors also having a stepped profile in side elevation, the middle being a full height section and both end portions being of reduced height, a groove extending vertically through the entire height of the end portions and longitudinally from both ends to the beginning of the full height section, a portion of the full height section being of reduced width and the remainder being full width, a transverse vertical slot extending from the level of the reduced height end portions through said reduced width portion, which slot being in the middle of the connector and having a longitudinal width equal to said full width; said two connectors being fitted transverse to each other with the slot of one fitting into the slot of the other and over the respective full width portions of the two connectors, and said beam fitting onto the end portion of one of said two connectors, the reduced width portion of the beam frictionally fitting into the groove of the one connector and the reduced width portion of the one connector fitting into the groove of the beam so as to form a longitudinal extension of the connector with the beam, thereby forming a twodimensional joint having structural continuity through the intersection point of two connectors.
2. Construction means as claimed in claim 1 wherein said beam has a reduced height end portion at both ends, said groove extends vertically through the entire height of both end portions and longitudinally from both ends to the beginning of said full height section, and there are two reduced width portions each one longitudinally extending from said full width middle portion to each reduced height end portion.
3. Construction means as claimed in claim 2 wherein each connector additionally has an aperture extending vertically from said slot through the full width portion of the full height section, and when the two connectors are fitted together transverse to each other the apertures of the two fitted connectors are aligned.
4. Construction means as claimed in claim 3 in combination with an elongated column having a reduced in cross-section portion at one end, which reduced portion is fitted through said aligned apertures so that one of the connectors rests on a ledge at the transition from the reduced to the full size cross-section of the column, thereby forming a three-dimensional joint having structural continuity through the joint in all three axes, said column being positioned vertically and the transverse connectors extending horizontally.
5. Construction means as claimed in claim 4 wherein said two connectors are fitted at to one another; said aligned apertures are square in cross-section; and said reduced cross-section on the column is square.
6. Contruction means as claimed in claim 1 wherein said beams and connectors are made of plywood and in the assembled condition the beams and connectors have a continuous channel running along at least one longitudinal edge.
7. Construction means as claimed in claim 4 including at least four columns, eight connectors and four beams connected so as to form a three-dimensional encloseable framework for a low-cost building structure.