US3817010A - Beam strengthening method and apparatus - Google Patents

Abstract

This invention is a strengthening and straightening method and apparatus for beams of wood or the like in which previously warped beams or those subject to warping have been straightened or are conditioned against warping by a tension strap which applies tensioning forces to the beam.

Description

United States Patent [191 Stegmuller June 18, 1974 BEAM STRENGTHENING METHOD AND APPARATUS [56] References Cited [76] Inventor: Charles D. Stegmuller, Moosa UNITED STATES PATENTS Canyon Rd, Bonsall, Calif. 92003 3,686,809 8/1972 Lindal 52/223 R [22] Filed: 1973 Primary Examiner-Henry C. Sutherland [21] Appl. No; 339,404 Assistant ExaminerCarl D. Friedman [63] Related [1.8. Application Data [57] ABSTRACT Cimlinunlion-impun of Ser. Nos. l32.69l. April 9, I971, Pat. No. 3,722,562,211! Ser.No. 299.792,0m. mvem'on a Strengthenmg and stralghtenlng 24 I972. rnethod and apparatus for beams of wood or tl e like 1n WhlCh prevlously warped beams or those sub ect to [52] Us CL 52/223 R 52/29l 52/727 warping have been straightened or are conditioned 511 Int Cl. .1 1564c 3/10 f warping by a tension Strap which applies [58] Field of Search 52/223 R, 727, 736, 514, 810mg forces the beam 2 Claim, 7 Drawing Figures BEAMSTRENGTHENING METHOD AND APPARATUS CROSS REFERENCE TO RELATED PATENT APPLICATIONS This application is related to and a continuation in part of my co-pending patent applications, Ser. No. 132,691, filed Apr. 9, 1971, now, U.S. Pat. No. 3,722,562 and Ser. No. 299,792, filed Oct. 24, 1972.

BACKGROUND OF THE INVENTION l Field of the Invention This invention relates to the field of wooden and other beams, and particularly to a method and device for straightening such beams when they have been warped and of holding the same in a straightened position, as well as to a method and device for improving the strength and resistance to warping of such beams or beams which will be subject to warping so that increased stability and strength in use is provided.

2. Description of the Prior Art With the exception of my co-pending patent applications, Ser. No. 132,691, filed Apr. 9, 1971, now, U.S. Pat. No. 3,722,562 and Ser. No. 299,792, filed Oct. 24, 1972, there is no prior art known for accomplishing the straightening of beams by purely mechanical means and methods and in which the tension forces within a warped or warpablebeam may be so applied as to hold them in a stable condition with increased strength and resistance to warping by their own forces of tension. The past prior art, with the exception of the foregoing applications, have been to steaming and other similar methods, none of which then utilized the natural forces within the beam to actually strengthen such beam and hold it against warping.

SUMMARY OF THE lNVENTlON Wooden planks and beams are used extensively in the construction industry. All sizes such as the very commonly used 2 X 4 and the like, are used in great quantity in the construction of most housing and for many other purposes.

Wood is well-known as an excellent building material and is most suitable for all types of construction and structures. Wood has unusual qualities of strength, durability, ease of handling, and the like, but it does have a characteristic fault in that frequently due to climatic conditions, or the like, wood beams will become warped or twisted.

When wooden beams are warped or twisted, they frequently become unusable resulting in great waste, or they are difficult to use and require unusual handling and placement.

Additionally, a beamwhich is warped, but which is then held in tension against the warping by the means as shown in this particular patent application, achieves great additional strength and stability against further twisting in use since there is an opposition of forces which, in essence, has prestressed the beam.

Those who are experienced in the lumber arts and in dustry can examine the straight beams and by closely examining the fiber alignment thereof, particularly those beams of heart wood (that wood from the center of the tree) may determine that there are strong possibilities that such a beam will warp. They can also tell from the examination of the fiber, the direction in which it will warp. Even other beams, such as plastics, metal, and the like, can be closely examined and, if necessary, placed in a bending moment to discover a warping direction, if the same exists, as it frequently will. When such warping direction is discovered, such warping direction as a tendency can be overcome by the method and apparatus particularly shown in this patent application. Thus, a beam which appears to be perfectly straight, but which has a tendency to warp under loading can be counteracted so that it will not warp at all. Since the beam will have a tendency to warp in one particular direction, by the method and means indicated herein, the warping tendency will be overcome. The beam, however, will not warp in the opposite direction, since the natural tendency to warp will hold it against that. In this manner, the usability and durability of beams of all types, particularly wood, but other beams as well, can be greatly enhanced.

It will be noted that beams can be actually purposely warped in one or another manner, even beams made of such materials as concrete, plastic, or the like, and the stability and effectiveness thereof improved by the use of the tensioning through straightening with the device and method herein described.

1 have devised amethod and means for straightening wooden beams, which have been warped without any requirement for complex and expensive equipment. Additionally, my method and device may be used for the purpose of improving the stability and strength of a beam which has previously been. warped, whether of wood or other material, in which tensioning straps are applied after twisting the beam with clamps, or the like, into a straight condition and when the clamps are removed the tensioning between the tendency to return to the warped condition and the restraining tensioning straps creates a new and strengthened material. And, I

have found that by anticipating a warping condition which will occur in the future, that my method and ap paratus can be utilized to prevent such future warping and to provide a beam having improved straightness and strength characteristics.

It is an object of this invention to provide an economical method and device for straightening wooden beams;

It is a further object of this invention to provide a method and device for straightening and strengthening warped beams;

It is a further object of this invention to provide a device in which the tensioning of a beam against a restraining force is achieved;

It is a further object of this invention to provide a method and device for preventing warping in beams which would otherwise Warp under loading, or aging.

The foregoing and other objects and advantages of this invention will be clear to those skilled in the art upon reading the following Description of a Preferred Embodiment together with an examination of the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS HO. 1 illustrates a twisted wooden beam which is being prepared for straightening by the method and means herein;

FIG. 2 illustrates the straightened beam after straightening has been completed;

FIG. 3 indicates a straightened beam with a previous twisted condition shown in dotted lines near one end thereof and in which a decorative strapping is used for straightening;

FIG. 4 illustrates a beam of a different material which has been purposely formed in a warped condition and then straightened by this invention to induce a tensioned condition.

FIG. 5 is the same view as FIG. 4 in which the clamps have been removed from the straightened beam and lines of force are illustrated showing the tensioning effect;

FIG. 6 illustrates a wooden beam which would have a tendency to warp in the direction of the phantom lines but which has been prevented from so warping by the method and device of this invention; and

FIG. 7 is a beam of the same nature as FIG. 6 in which the beam is held against warping by the method and a simplified and alternative embodiment of this invention.

DESCRIPTION OF A PREFERRED EMBODIMENT By reference to FIG. I, there is shown a beam 10 which is clearly in a twisted condition such as is frequently encountered in the field. It will be noticed that the alignment of the end of the beam 12 is considerably out of alignment with the end of the beam 14.

I have found that most beams of wood when so twisted, if twisted back into a condition of a complete alignment wherein the end 14 and the end 12 are perfectly aligned with one another results in a completely straight beam, since most beams will not tend to buckle or become twisted otherwise when straightened out.

Immediately upon releasing any pressure, which has been brought to bear to bring the ends into alignment, however, normally the beam will once again twist. This is even frequently true if the beam is carefully steamed and pressed into condition and dried carefully.

It will be noted by further reference to FIG. 1 that it is held at one end by a clamp 30 and at the other end by a like clamp 30. These two clamps are then rotated with reference to one another either by hand or by in turn fastening extensions to said clamps and by hand or machine bringing them into alignment so that the beam is aligned as indicated in FIG. 2. The twisting action required for this purpose is clear and is illustrated in the FIGURE.

It will be seen that a strap which may be of ordinary steel strapping material, or the like, has been cut to an appropriate length to make several wraps around the beam in question. Each end of the strap has been provided as at 21 and 22 with a hole suitable to accommodate a strong lag bolt 23 and 24 respectively.

After the beam has been twisted into its straightening position as illustrated in FIG. 2, the lag bolt 23 is fastened in position and thereafter the strap 20 is carefully and tightly wrapped around the beam conforming to the natural contour of the beam and without allowing slack therein. The opposite end of the strap 20 is fastened adjacent to the other beam end by lag bolt 24 through the hole 22.

It is also deemed desirable to staple or otherwise fasten the strap at numerous additional positions on the beam such as indicated by the rectangular marks on FIG. 2 and such fastening would be by staple or the like, as indicated by the numeral 25 in certain of these instances.

It is important to notice the directional alignment of the strap 23 with reference to the condition of twisting previously existing in the beam. The condition of twisting previously existing in the beam as indicated in FIG. 1 would have been, if looking from the direction of end 14 towards the direction of 12 in a counter-clockwise direction from top to bottom of the end 14. After being straightened by pulling in a clockwise direction, it is necessary that the strapping be applied from end 12 towards end 14 in a counter-clockwise direction, that is in the same direction of the twist previously existing. A simple examination will show that this is necessary because of the tensile forces set up when the beam attempts to warp after the twisting forces have been removed.

In FIG. 3, there is illustrated another beam 40 and a prior twist condition at 42 has been shown. It should be noticed that strapping 50 has been applied by lag bolts 53 and 54. Additionally, however, the strapping 50 is noted to have several marks or designs about it and is supplemented by another like strap 55 in the opposite direction. The only reason for this is for decorative effects and to give an appearance of symmetry to the entire finished item when desired.

By paying particular attention to FIGS. 4 and 5 the unique advantages obtained from the application of this method and device will be clear. When a beam has been in a twisted condition, there are, of course, certain forces set up tending to hold the beam in that direct condition. Such forces are not, however terribly effective since further warping in the direction of warpage is easily possible and, likewise, it is easily possible to warp or bend partially in the reverse direction. It is true that a complete reversal of the direction of warping is unlikely and extremely difficult to obtain. This works to the advantage of my method and device.

As is illustrated, when the warped beam is completely straightened and my device has been applied to main tain it in that straightened condition, then, there is virtually no possibility for further warping under use. The beam being warped in one direction cannot readily be warped in the other direction and, in fact, this becomes very nearly impossible. Likewise, however, the tensioning strap now prevents the beam from warping in the other direction (its natural warp direction), and for this reason, we have a completely stable beam which finds that it cannot become warped in either direction.

If careful attention is given to FIG. 4, it will be noted that FIG. 4 is a beam of plastic which has been warped and then straightened by the method and device herein described. In FIG. 4, it will be seen that the beam is in a straight condition with its ends 112 and 114 in alignment as is appropriate with a straight beam. These ends are held by clamps which were used to straighten the previously warped beam. These clamps have been indicated simply by the general reference numeral 130.

At 214, there is illustrated in phantom the condition of the beam 110 before it was straightened and in its originally warped condition.

The tensioning strap is secured at its ends by lag bolts, or the like, 123 and 124, and the strap has certain decorative effects 125 formed by staples holding the strap at various locations about the beam.

FIG. 5 is the same as FIG. 4 except that the clamps have been removed from the ends and the phantom drawing of the warped end is not shown.

Instead of that, however, there is shown a force line 100, which indicates the normal twisting force within the warped beam tending to go back to its warped condition.

Likewise, tensioning forces within the strap 102 and 104 are illustrated by the arrows and it is seen that these are opposed to the force tending to twist in the natural warped condition.

Thus it will be seen that an attempt to warp the beam, or twist it, in the original warped direction, such as the pulling of the force or additional forces in the direction 100 will be restrained by the strap and its tensioning forces 102-104.

Likewise, it will be seen that if it were attempted to warp the beam or twist it in a direction opposite to its original warped direction, that the tension of the initial warping forces 100, which are being restrained by the strap will prevent such further warping in an opposite direction.

FIG. 6 illustrates a beam 310 having ends 312 and 314 and in which at least one end would have a tendency to warp in the direction indicated at 414, but which has not actually so warped.

A strap 320 has now been applied in a manner similar to that described in connection with the other FIG- URES relating to this invention and held in position adjacent its ends 312 and 314 by appropriate screws, bolts, or the like, 323 and 324 respectively. It will be clear that when this beam now attempts to warp, whether under loading stress or otherwise, it will be held against such warping. On the other hand, it cannot warp in the other direction since the internal forces tending to warp it in the direction indicated will prevent its warping in the other direction. This beam is now stable and may age or be subjected to loads without danger of warping as previously not only existed, but would have been the natural outcome of such loading or aging.

FIG. 7 illustrates a very simplified device for practicing the method of this invention. It will be noted that a beam 510 having ends 512 and 514 has a tendency to warp adjacent one of its ends at least, generally in the direction 614. Prior to such warping taking place, or for that matter, after warping and straightening, strap 520 is applied to one side and fastened adjacent one corner by appropriate bolt, or the like, 523, and appropriate and adjacent another corner by bolt, or the like, 524.

This embodiment as shown in FIG. 7 may or maynot be fully effected depending upon the exact configuration of the beam being straightened, strengthened,'and- /or held against warping forces. In some cases, the breadth of the side to which the strap is fastened may be such that it will not be quite sufficient, or for other 5 reasons it might not be quite sufiicient. The width and the configuration as well as the overall warping tendencies may be important in this regard. It may, for example, be desirable to fasten such a strap with one end fastened adjacent a comer on one side and the other end 0 adjacent an edge, or the like, in which a partial crossing of the beam is appropriate. Likewise, the number of loopscompletely around the beam may be one or a multiplicity, depending again upon the shape and configuration.

It will now be noted that I have not only provided the means for straightening previously warped beams and strengthening beams by warping and straightening, but by appropriate inspection, a natural warping tendency of a beam may be discovered and it may be prevented before it occurs, as well as being corrected after it occurred. In such case, or in either case, the result is an improved article which now will not warp since the natural warping forces within the beam under the appropriate conditions will be offset by the tensile strength of the strap applied in appropriate manner. In this way,

a beam which might otherwise collapse or become unsightly in use can be relied upon to the fullest extent of its natural strength and, in some cases, beyond such strength because of the counteraction of the natural twisting forces with the tensile strength of the strap applied.

While the embodiments of this invention shown and described are fully capable of achieving the objects and advantages desired, it is to be noted that these embodiments are for illustrative purposes only and are not to be considered by way of limitation,

I claim:

1. The method of preventing warping in a beam comprising:

a. Examining the beam to determine the direction in which it may ultimately warp;

b. Fastening a strap adjacent one corner of one side of said beam; and fastening the other end of said strap to a point on said beam such that the strap passes in a diagonal direction across at least one side of such beam so that any warping forces tending to warp said beam will act against the tensile strength of said strap as so fastened.

v2. The method of claim 1 in which the said strap 50 contacts more than one side of said beam and is fastened at one end adjacent one end of said beam and at its other end adjacent the other end of said beam.

Claims (2)

1. The method of preventing warping in a beam comprising: a. Examining the beam to determine the direction in which it may ultimately warp; b. Fastening a strap adjacent one corner of one side of said beam; and fastening the other end of said strap to a point on said beam such that the strap passes in a diagonal direction across at least one side of such beam so that any warping forces tending to warp said beam will act against the tensile strength of said strap as so fastened.

2. The method of claim 1 in which the said strap contacts more than one side of said beam and is fastened at one end adjacent one end of said beam and at its other end adjacent the other end of said beam.

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