BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the structure of a sectional container semi-trailer of 53 feet;
FIG. 2 illustrates the structure of a conventional joint;
FIG. 3 illustrates the a main beam of container semi-trailer with the conventional joint;
FIG. 4
a is a three-dimensional drawing of a joint according to the preferred embodiment of the present invention;
FIG. 4
b illustrates the structure of a web plate of the joint shown in FIG. 4a;
FIG. 5 is a side view of the web plate in FIG. 4b;
FIG. 6 is a three-dimensional drawing of a joint pair respectively with a positive arrangement and a reverse arrangement;
FIG. 7 is a three-dimensional drawing of the joint pair connected to the front beam and the rear beam respectively;
FIG. 8 illustrates the beam being assembled by using the joints;
FIG. 9 illustrates the assembled beam with joints;
FIG. 10 illustrates another joint according to another preferred embodiment of the present invention;
FIG. 11 illustrates the beam being assembled by using the joints illustrated in FIG. 10; and
FIG. 12 is illustrates the assembled beam with the joints in FIG. 11.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A joint according to the present invention is described hereinafter with reference to a preferred embodiment. As shown in FIG. 4a, the joint 10 comprises: a first connecting plate 11 connected to the main beam; a second connecting plate 12 and a third connecting plate 13, both of which are secured to the same side of said first connecting plate 11 and spaced apart by a certain distance; and a fourth connecting plate 14 slantingly connected between said second connecting plate 12 and said third connecting plate 13. Two holes 19 for fasteners are disposed on each of said second connecting plate 12 and said third connecting plate 13, and four holes 19 for fasteners are disposed on the fourth connecting plate 14. The second to fourth connecting plate 12˜14 are disposed on the same side of the first connecting plate 11, and in one embodiment of the present invention, the slant angle between said second and third connecting plate 12,13 and said first connecting plate directed towards the same direction. The first connecting plate 11 is designed corresponding to shape of the cross-section of the main beam to achieve a better connection. For example, the first connecting plate 11 is designed with an I-shaped cross section to match the I-shaped cross section of the main beam. As shown in FIG. 4b, a web plate 18 is disposed in a chamber defined by the four connecting plates 11, 12, 13, and 14, for example the web plate 18 is disposed at a symmetric plane of the chamber. The web plate 18 connects the first to fourth connecting plate 11˜14 to reinforce the joint 10. Two first reinforcing ribs 16 are disposed on both sides of the web plate 18 connected to the fourth connecting plate 14. The third connecting plate 13 has a connecting surface directed toward the second connecting plate 12. A second reinforcing rib 15 is disposed on the surface of the third connecting plate 13 opposed to said connecting surface. In addition, as shown in FIG. 5, the second and the third connecting plate 12, 13 are slightly slantwise relative to the fourth connecting plate 14 by the same angle, thus forming a whole connecting joint (hereinafter named “joint”). In one embodiment of the present invention, the joint is made by steel-casting. According to operational condition, the joint with the same or similar performance can be manufactured by means of other suitable means such as forging or powder metallurgy.
Now illustrates how to connect the main beam using said joint. FIG. 6 shows two oppositely disposed joints 10a and 10b, wherein joints 10a and 10b have the same structure, just the directions are of 180° difference. The same slant angles of the second and the third connecting plate 12, 13 enable the joints 10a and 10b to engage with each other. When connecting the main beam, first two joints 10a and 10b are secured to a front beam 2a and a rear beam 2b of the main beam respectively, as shown in FIG. 7. Then, the secured joint pairs 10a, 10b are connected. As shown in FIG. 8, for example, first fix the end on which the joint 10a is secured, then the end on which the joint 10b is lifted a little be and approached to the joint 10a, and joint 10b is engaged into joint 10a so that the second, third and fourth connecting plate 12a, 13a, and 14a of joint 10a are in contact with the third, second and fourth connecting plate 13b, 12b, and 14b of joint 10b respectively. During the above-mentioned assembling, the second and the third connecting plates 12a and 13a of the fixed joint 10a provide a limit in the vertical direction, and the fourth connecting plate 14a of the fixed joint 10a provide a limit in the horizontal direction so that it is easy to achieve orientation when joint 10a and 10b are closed up. Afterwards, fasteners 21, for example bolts, are inserted into the holes 19 and screwed down to reliably connect the joints 10a and 10b, thus the front beam 2a and the rear beam 2b are connected. The connected beams are illustrated in FIG. 9.
When the vehicle is moving, forces caused by stretching, bending, twisting or shearing and the like are transferred to the joints through the main beam of container semi-trailer. In the present invention, the second and the third connecting plates are slantwise inwardly relative to the fourth connecting plate, and the second, third and fourth connecting plates 12, 13 and 14 of the joint pairs 10a and 10b are engaged with the respective ones. Therefore, the engaged second connecting plates and the third connecting plates bear a horizontal stretching force exerted on the joints. Similarly, the second connecting plates and third connecting plates bear a tension force caused by bending of the joint. The second, third and fourth joints bear the vertical shearing force on the joints. Similarly and obviously, the second, third and fourth joints bear a toque when the joint is twisted. Hence, the fasteners such as bolts are used to connect the joints without bearing external forces exerted on the joints. Because the pretightening force to connect the joints is relatively small and there is no alternate tightening and loosening, the bolts has an improved stress, and thus the service life and reliability of the connection are increased.
Furthermore, the stress distributions of the joints of the present invention and the conventional joints (as shown in FIG. 3) are of great difference. In the present invention, the external force mainly act upon the second, third and/or fourth connecting plates, wherein the area of the load bearing cross section is much greater than that of the prior art. Therefore, the stress condition on the joints of the present invention is much better than that of the joints in the prior art. Additionally, when the external force which causes the deformation act upon the joints of the present invention, the second and the third connecting plate are far away from a neutral layer of deformation of the joints so that the practical stress distributions of said second and third connecting plates are also improved. Hence, the joints having such a design have a longer service life.
FIG. 10 illustrates a joint 20 of another preferred embodiment according to the present invention. Said joint 20 comprises: a first connecting plate 21 connected to the main beam; a second connecting plate 22 and a third connecting plate 23, both of which are connected to the same side of the first connecting plate 21; and, a fourth connecting plate 24 slantingly connected between said second connecting plate 22 and said third connecting plate 23. Specially, the second connecting plate 22 comprises a bent portion 221 secured to the first connecting plate 21 and a base 222, wherein the bent portion 221 is sunk from the surface of the base 22. Also, the third connecting plate 23 comprise a bent portion 231 and a base 232, wherein said third connecting plate 23 is connected to the first connecting plate 21 through said base 232, and the second bent portion 231 is protruded from the surface of said base 232. The two opposite ends of the fourth connecting plate 24 are secured to the base 222 and the bent portion 231 respectively.
Similarly, when connecting the beam, the joint pairs 20a and 20b are first secured to a front beam and a rear beam of the main beam respectively. For example, as shown in FIG. 11, the first joint 20a is welded to the front beam 2a through the first connecting plate 21a while the second joint 20b is welded to the rear beam 2b through the second connecting plate 21b. Then, the two joints 20a and 20b are closed up to each other. The bent portion 221a and the base 222a of the second connecting plate 22a of the joint 20a and the bent portion 231a and the base 232a of the third connecting plate 23a of the joint 20b, the fourth connecting plate 24a and the 24b, the bent portion 231b and the base 232b of the third connecting plate 23b and the bent portion 221b and the base 222b of the second connecting plate 22, are closed up to each other respectively. Finally, the joints 20a and 20b are connected by fasteners to achieve the connection of the front beam 2a and the rear beam 2b. The assembly is illustrated in FIG. 11, and the connected beams are illustrated in FIG. 12.
The other structure of the joint 20 and the principle of improving the stress distribution of the connection by the joints 20 are similar to the aforementioned embodiment and will not be described again in detail here.
It should be understood that although an object of the present invention is to solve the problem of transporting the extremely long semi-trailer using containers, the joint can also meet the requirement of connecting other similar structure.
While the invention has been described with reference to the specific embodiments described above, it is evident that many alternatives, modifications and variations are apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative and not limiting. Various changes can be made without departing from the spirit and scope of the invention.
Patent Application
20080035814
