US 3216585 A
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Description (OCR text may contain errors)
Nov. 9, 1965 c. E. WHITTLE 3,
REINFORCED TUBULAR PALLET Filed Jan. 20, 1964 2 Sheets-Sheet 1 FIG! FIGZ Fl G INVENTOR.
CHARLES E. WHITTLE A TTORNE Y Nov. 9, 1965 c. E. WHITTLE 3,215,535
REINFORCED TUBULAR PALLET Filed Jan. 20, 1954 2 Sheets-Sheet 2 FIG? 4 INVENTOR.
CHARLES E. WHITTLE ATTORNEY United States Patent 3,216,585 REINFORCED TUBULAR PALLET Charles E. Whittle, 903 Monk St., Brunswick, Ga. Filed Jan. 20, 1%4, Ser. No. 338,695 Claims. (Cl. 211-60) This invention relates broadly to pallets, and more particularly to an improved reinforced pallet for handling heavy logs or pulpwood for the pulpwood industry.
The present invention is an improvement of the pallet structure disclosed in my Patent No. 2,529,752, issued November 14, 1950, for Method and Apparatus for Loading and Transporting Logs and Other Materials. In order to decrease operating costs and increase efficiency of operation, it is the desire of the pulpwood industry to carry larger loads of pulpwood without materially increasing the weight and size of the equipment used to load and transport the pulpwood. In order to accomplish this, the tendency in the trade has been to increase the heights of the upright standards of the pallet shown in my previously-mentioned patent, thus allowing more pulpwood to be loaded in each pallet. Although no difficulties have as yet been encountered the gradual increase in loads, without increasing the weight and size of the material from which the pallet is constructed, is rendering the older pallet designs unsuited for these increased loads.
The weakest point of a tubular pallet is normally at the curved portions at the base of the U-shaped sections which make up the pallets. With the tendency to make the pallet standards higher for holding more pulpwood, and the reluctance to increase the weight of the tubular material from which the standards and the curved portions are constructed, the increased weight places more bending stress on the curved portions so that these older pallets are presently carrying the maximum loads which they are structurally capable of handling. If the standards are constructed any higher than the maximum heights presently being used, the older pallet structures will have a tendency to break at the lower curved portions since the increase in load will stress the curved portions beyond their structural strength.
Since the trend in the pulpwood industry of carrying progressively larger loads is continuing, and does not appear to be leveling off, it is imperative for the industry to have an improved pallet construction of greater strength which is capable of carrying the heavier loads required by the industry. It is therefore an object of the present invention to provide a construction of pulpwood pallet having greater structural strength than those presently used in the industry without increasing the weight of the pallet.
Another object of the invention is to provide a construction of tubular pallet having novel means for reinforcing the pallet at its weakest points.
A further object of the invention is to provide a reinforced pulpwood pallet capable of handling increased loads which is simple in construction and economical to manufacture.
Other and further objects of the invention reside in the novel structure for reinforcing the curved portion of the pallet to eliminate the tendency of the pallet to break at the curved portion under increased loads, and will become apparent to those skilled in the art from the specification hereinafter following, and with reference to the accompanying drawings, in which:
FIG. 1 is a side elevational view of the pallet structure of the invention loaded with pulpwood;
FIG. 2 is an end elevational view of the pallet structure of FIG. 1, with the pulpwood load being omitted;
FIG. 3 is an enlarged horizontal sectional view, partly in elevation, of a fragmentary portion of the pallet structure, taken substantially along line 3-3 of FIG. 1, with the pulpwood load omitted;
FIG. 4 is a vertical sectional'view of a fragmentary portion of the pallet structure, with the view being taken substantially along line 4-4 of FIG. 3;
FIG. 5 is an enlarged crosssectional view taken substantially along line 55 of FIG. 4, and particularly showing the manner in which the load-supporting member is connected to the pallet tubular section;
FIG. 6 is a perspective view on a reduced scale of the preferred form of the tension reinforcing member of the pallet structure;
FIG. 7 is a perspective view of a modified form of the tension reinforcing member of FIG. 6; and
FIG. 8 is an elevational view of a fragmentary portion of the pallet structure, similar to FIG. 4, with parts omitted, showing the manner in which the modified form of tension reinforcing member of FIG. 7 is assembled on the pallet structure.
Referring to the drawings in greater detail, the pallet structure of the invention includes a pair of U-shaped end frames 1 and 2, with each of the U-shaped end frames formed of tubular material, such as, for example, 3 /2" outside diameter pipe. Each end frame member includes a pair of upright standards 3 joined to a horizontal bottom portion 4 by means of the curved portions 5 and is preferably die-formed from a single piece of tubular material.
In the preferred form of the invention an angle member, having a top horizontal flange portion 6 and a vertical wall portion 7 having its end extremities 8 and 9 tapered upwardly and terminating in top horizontal flange 6 at the ends thereof, is bent upwardly at each end by dieforming or the like to form a curved beam reinforcing member which is of shallow U-shape, as shown particularly in FIGS. 1, 4 and 6. Thus, the cross-section of the curved beam member gradually reduces at opposite ends of the curved beam. The top horizontal flange is preferably approximately the sarne width as the diameter of the tubular material from which the U-shaped end frames 1 and 2 are formed, and is curved at the vertical portions 10 and 11, at opposite ends thereof to conform to the profile or surface curvature of the upstanding tubular standards 3. Thus the end portions 10 and 11 of the curved beam member are curved in the vertical plane about axes parallel with the longitudinal axes of the upstanding standards 3.
A curved beam member thus formed is positioned between the upstanding standards 3 of each of the U-shaped end frames, such that the vertical wall portion 7 thereof lies substantially tangent with the outside diameter of the bottom portion 4 of the end frame, as shown particularly in FIG. 5, with the bottom edge of the vertical wall portion 7 lying in abutment with the side of the bottom tubular portion and rigidly welded thereto substantially throughout its length. The vertical portions 10 and 11 of the curved beam member abut the surfaces of the upright standards 3 which are directed toward each other just above the end frame curved portions 5 and are secured thereto along only the vertically extending edges thereof by means of the vertical welds 12 and 13. It is important to note that no horizontal weld is provided between the upstanding standards 3 and the nd of the vertical portions 10 and 11 of the cur ed beam member since this would tend to greatly weaken the structure, and it has been found that greater strength is provided by the pallet structure by providing only the two vertical welds 12 and 13 in connecting the curved beam member to the vertical portions of the standards 3. The bottom edge of the vertical wall portion '7 including the curved tapered vertical wall portions 8 and 9 are secured by welding substantially throughout their length to the curved portions 5 and bottom horizonal portion 4 of the U- end of the pallet to the other.
shaped end frame member. It will be noted that this weld extends longitudinally of the tubular member from which the end frame is constructed, as opposed to extending transversely thereof.
The end frames 1 and 2 constructed in the manner described, and each having a curved beam secured adjacent the top surface of the horizontal portion 4, are interconnected in spaced relation adjacent their bases in the area of the curved portions 5 by means of tubular cross members 14 and 15 which, as shown, in FIG. 5, are welded partly to the inner side walls of the U-shaped end frame at the curved portions 5 and partly to the curved tapered vertical wall portions 8 and 9 of the curved beam members. It will be noted that the vertical wall portions 7, 8 and 9 of adjacent end frames 1 and 2 are positioned inwardly of the pallet structure to provide a connecting surface for the tubular cross members 14 and 15, and the top flanges 6 of the curved beam members extend outwardly of the pallet structure above the horizontal bottom portions 4.
An apertured horizontally extending lug 17 is secured by welding or the like to each of the tubular cross members 14 and 15 in positions extending horizontally outwardly of the pallet structure, as shown in FIGS. 1 and 3. These apertured lugs are adapted to be engaged by the hook of a winch for pulling the loaded pallets on to the bed of a transportation body and also serve as holddown ties for securing the pallets to the transportation body, during transportation, as set forth in my previously mentioned Patent No. 2,529,752. The pallet structure is completed by means of reinforcing gusset plates 18 Welded between each of the end frame members and the tubular cross members 14 and 15, to reinforce the cross members against the pulling stresses exerted on them by the winch cable through the apertured lugs 17 when the loaded pallets are pulled by the winch on to a transportation body.
The pallet structure thus formed constitutes an openframework and provides a rigid support for the heavy load of logs, indicated generally at 16, loaded transversely of the pallet on top of the curved beam members. It will be noted that the curved beam members extend the entire length of the pallet structure and that the fibers of these beams are continuous and uninterrupted from one By keeping the fibers of these beams continuous the resistance of the beams against bending stresses is maintained.
The weight of the logs 16 loaded in the pallet which would normally bear directly against the curved portions 5 of the pallet now bear against the top flanges 6 of the curved beam structures along the entire area of the curved portions 5 and since the angle member from which the curved beams are formed is relatively thin, the fibers of the beams are tensioned substantially throughout their lengths in the loaded condition, and since the curved beams are supported at their ends to the vertical portions or upstanding standards 3 of the pallet, above the curved portions 5, a majority of the reaction stress to the load occurs in the vertical standards 3, thus relieving the curved portions 5 of the U-shaped end frames from the extreme bending stresses which would normally cause breakage of these curved portions if the reinforced curved beam members were not present. As previously stated,
when the pallet is loaded the curved portions of top flanges 6, as well as the remaining portion of these flanges, are subjected to tensile stresses when the pallet is loaded with logs, and the vertical wall portions 7, 8 and 9 connected rigidly between these top flanges and the curved end frames 1 and 2 are subjected partly to tensile force but mainly to compressive forces. In any event, the manner in which the curved beam angle members are connected to the U-shaped end frames produces a pallet structure having a curved beam element at the base thereof which greatly reinforces the curved portions 5 of the .pallet while, at the same time, sacrificing very little load space within the pallet between the upright standards 3. This latter provision of the present structure is very important to the industry, since the reinforced pallet structure does not in any way reduce the loading space within the pallet.
In the pallet shown in my previously mentioned Patent No. 2,529,782, the rails on the end frames, Which support the main weight of the logs, are joined to the curved portions of the end frames along the curve, for example, approximately 8 inches above the bottom of the end frame. Thus, in the old form of the pallet structure, the supporting rails join the end frames along the curved portions and below the mid-point of the curved portions so that substantial weight from the logs bears directly against the curved portions of the pallet. In contrast to this, in the new form of the invention, as set forth in the present application, the curved beam log supporting memers have their opposite ends 10 and 11 connected to the upright standards 3 at points on the vertical portion of the standards just above the curved portions 5 by means of the vertical welds 12 and 13. By way of comparison with the older pallet construction, the weld joints 12 and 13 are approximately 21 inches above the base of the pallet, thus indicating that the curved beam portions overlie the entire area of the end frame curved portions 5.
The minute sacrifice to the interior load space of the pallet is achieved by the fact that the curved beam members afford a gradually reduced cross section at their end portions so that the assembled pallet structure also affords a gradually reduced section through the entire curved portions of the pallet. Since the curved portions of the pallet have this feature of the gradually reduced cross section, very little additional interior load space of the pallet is occupied by this new construction than was occupied by the pallet construction shown in my previous patent, and the gradually reduced cross section construction has been found to be greatly superior for the load bearing requirements of larger pallet structures than that disclosed in my previously mentioned patent. The new pallet structure is capable of bearing standards as high as 84 inches and can easily carry loads as large as two cords of pulpwood which would weigh approximately 11,000 pounds. The pallets may be constructed in different lengths with the lengths mainly being governed by the transportation body on which the pallets are loaded. The widths of the pallets are normally governed by the lengths in which the timber products are cut, and these of course usually do not exceed the maximum highway limits.
A modified construction of the curved beam member for constructing the pallet of the present invention is shown in FIGS. 7 and 8. In this form of the invention the vertical wall portions are removed from opposite ends of a straight angle member leaving only the center vertical Wall portion 7 connected to the top flange portion 6. The ends Ill and 11' of top flange portion 6' are then bent upwardly in the manner shown, in the same configuration as the preferred form of the invention, and the ends 10' and 11 are then curved in the opposite plane to conform to the contour of the upright standards 3. The curved beam member is then place on the U-shaped end frame and the opposite vertical edges of end portions 10' and 11 are welded at 13' to the upright standards 3. The lower edge of vertical wall portion 7 is welded to the side wall of horizontal bottom portion 4, as shown in FIG. 8. A pair of arcuate plates 8 and 9 having an upwardly tapering reduced width are then Welded in place between the curved beam member and the pallet end frame to form end wall extensions of vertical wall portion 7, that is, the inner arcuate edges of plates 8' and 9 are Welded to the inner edge of top flange 6, while the outer arcuate edges are welded to the curved portions 5 of the end frame and the widest ends of the plates are welded in abutment with the terminating ends of vertical wall portion 7 This modified construction has been found to perform just as efficiently as the preferred form of the invention, although it does require additional manufacturing steps.
While the invention has been described in certain preferred embodiments it is realized that modifications may be made without departing from the scope of the invention, and it is to be understood that no limitations upon the invention are intended other than may be imposed by the scope of the appended claims.
What I claim as new and desire to secure by Letters Patent of the United States, is as follows:
1. A pallet for carrying logs and the like comprising, a pair of end frame members each having a pair of upright standards connected to a base portion by a pair of curved frame portions, an upwardly curved member connected to each end frame member in overlying relation to said base portion and curved frame portions and adapted to receive the load carried by said pallet directly thereon and thereby be tensioned throughout its length to reinforce said end frame members, and transverse members interconnecting said pair of end frame members adjacent the bases thereof.
2. A pallet as set forth in claim 1 in which said upwardly curved member is connected at opposite ends to said end frame member above said curved frame portions.
3. A pallet as set forth in claim 2 in which the ends of said upwardly curved member are connected to said end frame member by welds extending only in the vertical plane.
4. A pallet as set forth in claim 1 in which the connection of said upwardly curved member and end frame member provides an upwardly progressing reduced crosssection at the curved frame portions.
5. A pallet as set forth in claim 1 in which said upwardly curved member is U-shaped, and is connected substantially throughout its length to said end frame member.
6. A pallet as set forth in claim 1 in which said upwardly curved member is angular in cross-section with opposite ends of the vertical wall thereof tapered upwardly.
7. A pallet comprising a pair of end frame membershaving a pair of upstanding standards connected to a base portion by a pair of curved portions, an upwardly curved member connected to each end frame member and adapted to receive the load carried by said pallet, each of said upwardly curved members having ends connected to said end frame member above the curved portions to thereby transfer stresses from the load to the upstanding standards, and each of said upwardly curved members connected intermediate the ends to said base portion, and transverse members interconnecting said pair of end frame members adjacent the bases thereof.
8. A pallet as set forth in claim 7 in which said transverse members are connected partly to said end frame members and partly to the upwardly curved members.
9. A pallet for carrying and transporting heavy loads comprising a pair of tubular end frame members of substantially U-shaped contour having vertically extending tubular end portions and a substantially horizontally extending base portion, a U-shaped beam extending longitudinal between the vertically extending end portions of each end frame member and connected at opposite ends to the lower ends of said vertically extending end portions, a body portion connecting said U-shaped beam intermediate the ends thereof in spaced relation above said base portion of said end frame member, and transverse members interconnecting said pair of end frame members adjacent the bases thereof whereby the top surfaces of said U-shaped beams are operative to receive the load carried by the pallet.
10. A pallet as set forth in claim 9 in which said body portion comprises a generally rectangular vertical wall portion connected between said horizontally extending base portion and said U-shaped beam, and a pair of arouate vertical wall portions connected on opposite sides of said rectangular vertical wall portion between the curved portions of said U-shaped end frame member and the curved portions of said U-shaped beam for reinforcing the end frame member.
References Cited by the Examiner UNITED STATES PATENTS 502,967 8/93 Hetrick et a1 182-217 1,021,280 3/12 Ungar 182-140 2,529,752 11/50 Whittle 2145 17 CLAUDE A. LE ROY, Primary Examiner.