MXPA06003994A - Movable subframe for semi-trailers - Google Patents

Abstract

A movable subframe or slider for semi-trailers includes a pair of spaced-apart, parallel and longitudinally extending main members. The main members are interconnected by a pair of longitudinally spaced, parallel and transversely extending horizontal cross members, a horizontally-disposed cross-brace structure, and a pair of longitudinally-spaced, parallel and vertically-disposed cross-brace structures. One or more axle/suspension systems are suspended from hangers which are mounted on and depend from the slider structure, and a retractable pin mechanism enables selective positioning of the slider relative to the trailer body for optimum load distribution and trailer versatility during vehicle operation. The integral slider structure supports the one or more axle/suspension systems, so that concentrated loads imposed on the slider via the axle/suspension systems during operation of the vehicle generally are dissipated throughout the entire slider structure.

Description

SUB-MOBILE FRAME FOR SEMI-TRAILERS DESCRIPTION OF THE INVENTION The invention relates to sub-frames of semi-trailers, and in particular to mobile subframes for semi-trailers. More particularly, the invention is directed to a mobile sub-frame for semi-trailers, which include one or more generally X-shaped or cross-shaped structures that replace one or more of the transversely extending transverse cross members of sub-frames. conventional frames, or alternately replace the K-shaped structures that extend transversely up to now, to more securely support one or more axle / suspension systems suspended from the sub-frame and to react more efficiently to the loads imposed on them. the sub-frame during vehicle operation, while reducing the total weight and possibly the cost of the sub-frame. Mobile subframes or secondary frames, typically referred to as slides in the truck industry, have been used in trailers-trailers or semi-trailers for many years. One or more axle / suspension systems are normally suspended from a single slide structure. The slider in turn is mounted on the underside of the chassis of the trailer or main frame, and can be moved longitudinally along it to increase maneuverability and provide a means of variable load distribution. Once properly positioned, the slide is fixed in place on the inside of the trailer, usually by a retractable pin mechanism. Conventional or prior art slide designs were developed prior to the arrival of trailer air suspension systems. At that time, spring suspension systems were the suspension option for trailers. However, the spring suspension system resulted in relatively rough handling for the load and was not equal in all situations, thus creating the need for a slide with smooth driving characteristics and efficient equal characteristics. The development of the slide resulted in a good distribution of variable load for trailers, which allowed the trailers to be more versatile. In addition, the subsequent development of air suspension systems provided equal load between multiple axles for semi-trailers, with or without the use of runners, as well as improved driving quality for individual axles. Of course, the combination of a mobile slider and an air suspension system provided maximum versatility with respect to variable load distribution and equal load in a trailer. Unfortunately, prior art slides equipped with air suspensions added unwanted weight to the trailer, mainly because those slides were originally built to support spring suspensions and adapted to incorporate air suspensions required additional bracing and support. Also, vehicles that contain more than one non-steerable axle, including semi-trailers, are subjected to lateral or secondary loads. Lateral loads can act through the slide in opposite directions, and the effect of such torsional loads on the slide can be important. In addition, a slide is subjected to strong vertical and longitudinal loads. A durable slide design must react effectively to such loads. Conventional prior art slide designs control vertical loads by using rigid, and therefore heavy, main members and cross members. However, such a rigid structure does not minimize the effect of lateral and longitudinal loads on the slide structure. The state-of-the-art slide design in the semi-trailer industry is the "K-frame slide", which is the subject of US Patent No. 5, 720,489, dated February 24, 1998, to Pierce et al., Which is assigned to the Boler Company, the assignee of the present application. This invention replaced at least four of the cross members of conventional prior art sliders with four shorter and lighter diagonal or inclined members, which when combined with the remaining pair of cross members results in a pair of structures In the form of K. These transversely extending K-shaped structures improved the ability of the slide to react to lateral, longitudinal and vertical loads, but also reduce weight and cost. Although the frame slide K was an improvement over conventional prior art sliders using only a plurality of transversely extending parallel cross members, the present invention solves certain problems associated with the frame slide K and thus is an improvement over the K-frame and conventional rack slides of the prior art. More particularly, the present invention reacts more efficiently to load vectors emanating from secondary or lateral loads and deformation loads by locating the struts generally at locations where those vectors occur. In contrast, the frame slide K, although it performs satisfactorily in most cases, fixes its K-shaped structures away from those particular load vectors, so that certain unwanted deflections and voltage risers still occur, resulting in in less than optimal integrity of the secondary frame frame structure. In this way, the present invention is stronger, reacts to loads more efficiently, is less expensive to manufacture, and is lighter than the conventional slide and frame designs K of the prior art. The objectives of the present invention include providing a slider for semi-trailers that has a significantly reduced weight than that found in prior art slides, yet having improved strength and ability to withstand vertical, longitudinal, rolling and especially secondary loads or lateral and deformation. Another object of the present invention is to provide such a slider for semi-trailers that can be manufactured more efficiently than the slides of the prior art. These objectives and advantages are obtained by the frame structure for a vehicle trailer of the present invention, the frame structure includes, a pair of parallel, longitudinally extending elongate main members, a pair of parallel transverse cross members separated which extend between and join the main members, a horizontally disposed strut structure extending between and joins the main members, and at least one vertically disposed strut structure extending between and joining the main members and in the hanging supports. BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention, illustrative of the best way in which the applicant has contemplated applying the principles, is established in the following description and is shown in the drawings and is pointed out particularly and distinctly and is established in the drawings. appended claims. FIGURE 1 is a perspective view of a conventional prior art slide for a semi-trailer having a plurality of transversely extending parallel cross members, showing the retractable pin mechanism used to selectively locate the slide as length of the inner side of a trailer, and also shows dependent hanging brackets for suspending axle / suspension systems; FIGURE 2 is a fragmentary elevation view of the prior art slide illustrated in FIGURE 1, but showing axle / suspension systems, with wheels / tires and concealed parts represented by dashed lines; FIGURE 3 is a fragmentary top plan view of a small size of the prior art slide shown in FIGURE 2; FIGURE 4 is a fragmentary elevation view, showing the prior art slide of FIGURE 3 movably mounted on the inner side of a trailer chassis; FIGURE 5 is an enlarged fragmentary front end view of the mounted slide shown in FIG.

FIGURE 4; FIGURE 6 is a perspective view of another prior art semi-trailer slide having a pair of K-shaped cross member structures, showing the retractable pin mechanism used to selectively locate the slide along on the inside of a trailer, and that also shows dependent hanging supports to suspend the axle / suspension systems; FIGURE 7 is an enlarged fragmentary elevation view of the slide shown in FIGURE 6, but showing one of the suspended axle / suspension systems, with a wheel / tire, portions of the suspension system, cross member structures and a towing crossbar in which the slide is movably mounted, shown in dashed lines; FIGURE 8 is a fragmentary top plan view of the slide shown in FIGURE 7; FIGURE 9 is a perspective view of the struts slide of the present invention, showing the retractable pin mechanism and the dependent hanging supports; FIGURE 10 is a top plan view of the slide shown in FIGURE 9; FIGURE 11 is an elevation view of the slide shown in FIGURES 9 and 10, but showing one of the axle / suspension systems; FIGURE 12 is a front end view of the slide shown in FIGURES 9 and 10; and FIGURE 13 is a fragmentary bottom front perspective view of the slide shown in FIGURE 12. Similar numbers refer to similar parts throughout the drawings. In order that the improved slide of the present invention can be better understood, a pair of slides of the prior art will first be described. A prior art slide for a semi-trailer is generally indicated at 20 and is shown in FIGURE 1. The slide 20 includes a pair of main members 21, a plurality of cross members 22A to F, front and rear pairs of hanging brackets 23A and 23B, respectively, for suspending axle / suspension systems and a retractable pin mechanism 24. Specifically, each main member 21 is a generally elongated C-shaped beam formed of a metal such as steel or other suitable strong material, and the other components of the slide 20, including the hanging supports 23 and the pin mechanism 24 they form a strong similar material unless otherwise noted. The open portion of each main member 21 opposes the open portion of the other main member and is internally confronted relative to the slide 20. The main members 21 are connected to each other in a parallel parallel relationship by the cross members 22A-F, which extend between and are perpendicular to the main members. Each end of each cross member 22 is nested in the open portion of a respective one of the main members 21, and secured therein by any suitable means such as welding or mechanical fastening. Each cross member 22 is a generally C-shaped beam formed of a metal such as steel or other suitable material, and has a plurality of openings 29 formed in its surface that extend vertically. The openings 29 are aligned with corresponding openings formed in the other cross members 22 to provide the passage of air and / or fluid conduits, electrical lines, and the like used in the operation of the semi-trailer (not shown). Each front hanger 23A is joined by welding or other suitable means, to the lowermost surface of a respective one of the main members 21 to a location directly under the cross members 22A, B. Each rear hanger 23B similarly joins a location directly under the members 22D, E in cross. Each main member 21 has a pair of crossbar guides 25 mounted on its outer surface by bolts 26. Each crossbar guide 25 is mounted adjacent to a respective one of the front and rear ends of the main member 21. A low friction band 27 is attached to the uppermost surface of each main member 21 by means of recessed fasteners 28, and generally extends the entire length of the main member 21. The web 27 is formed of any suitable low friction material, such as ultra high molecular weight polyethylene. As mentioned in the foregoing and as best shown in FIGURES 2 and 3, the slide 20 of the prior art supports the systems 30A and 30B of e e / front and rear suspension, respectively. Since each axle / suspension system 30A, B is suspended from the slider 20, but does not form an integral part thereof, only the major components of the system 30 will be cited to assist in the description of the environment in which the slider operates. of the prior art. Each axle / suspension system 30A, B includes generally identical suspension assemblies 31 suspended from each of the pair of hangers 23A, B, respectively. Each suspension assembly 31 includes a suspension beam 32 which is pivotally mounted to the suspension bracket 23 in a conventional manner. A pneumatic spring 33 is suitably mounted on and extends between the upper surface of the rearmost end of the suspension beam 32 and the main member 21 in a location directly under one of the cross members 22C, F. A shock absorber 34 extends between and is mounted on the suspension beam 32 and a certain cross member 22. One or more reinforcement posts 60 are strategically joined within each member 22C, F crosswise to reinforce the cross member to support the suspension assemblies 31. Other components of the suspension assembly 31, mentioned herein for relative fullness only, include an air brake 35 and a height control valve 36. An axle 37 extends between and is captured in the pair of suspension beams 32 of each axle / suspension system 30A, B. Wheels / tires 38 are mounted on each end of the shaft 37. The slide 20 is movably mounted on the trailer chassis 40 (FIGURES 4-5) by sliding engagement of the cross-member guides 25 with the cross-links 41 generally Z-shaped and parallel separate ones that are mounted on and depend on the inner side of the main frame members (not shown) of the trailer chassis. Each low friction band 27 splices the lower surface of the uppermost portion of a respective one of the crosspieces 41 to provide a smooth friction-free contact surface generally for slidable movement of the slider 20 on the towing chassis 40. The slide 20 is selectively positioned relative to the trailer chassis 40 for optimum load distribution and trailer versatility by the retractable pin mechanism 24 engaging the selected ones of the openings 53 formed in the cross members 41 in a manner well known to those skilled in the art. who have ordinary experience in the truck technique. Another semi-trailer slide of the prior art is generally indicated at 120 and is shown in FIGURE 6. Although the slide 120 of the prior art is similar in many respects to the slide 20 of the prior art described in detail in the foregoing and shown in FIGS. 1-5, the slide 120 is different from the slide 20 in certain aspects. The slide 120 is the object of the North American Patent No. 5,720,489 referred to in the foregoing. The structural differences between the slides 120 and 20 will be described in detail immediately in the following. The slider 120 includes a pair of main members 121, cross member structures 122A and 122B generally in the form of a front and rear K, respectively, front and rear pairs of hanging supports 123A and 123B, respectively, for suspending the axle systems. suspension, and a retractable pin mechanism 124. Specifically, each main member 121 is a generally elongated C-shaped beam formed of a metal such as steel or other suitable material and the other components of the slide 120, including the hanging supports 123 and the pin mechanism 124 are formed from a strong similar material unless otherwise noted. The open portion of each main member 121 is opposite the open portion of the other main member and is internally confronted relative to the slide 120. The main members 121 are connected to each other in a parallel parallel relationship by the member structures 122A, B K-shaped cross. Each K-shaped cross member structure 122 includes a base member 160 that extends between and is perpendicular to the main members 121. Each base member 160 is a generally C-shaped beam formed of a metal such as steel or other suitable material. The open portion of each base member 160 is confronted in a front direction. Each end of the base member 160 is nested in the open portion of a respective one of the main members 121, and secured therein by any suitable means such as welding or mechanical fastening. Each front hanger bracket 123A is attached, by welding or other suitable means, to the lower surface of a respective one of the main members 121 in a location directly under the base member 160 of the front K-shaped cross member structure 122A. . Each back bracket 123B similarly joins in a location directly under the base member 160 of the rear K-shaped cross member structure 122B. Each K-shaped cross member structure 122 further includes a pair of inclined members 161, of which each is a generally C-shaped beam also formed of a metal such as steel or other suitable strong material. The open portion of each inclined member 161 is confronted in an outward-facing direction and each of the inclined members extends between generally the middle portion of the base member 160 and a respective one of the main members 121. The front end of each inclined member 161 is attached to the rearmost surface of the base member 160 at an angle by any suitable means such as welding or mechanical fastening., and the rear end of each of the inclined members is nested at an angle in the open portion of a respective one of the main members 121, and is also joined thereto by any suitable shape such as welding or mechanical fastening. An optional reinforcing bar 171, which extends between the more posterior ends of the main members 121, adds additional strength to the structure, and is bonded thereto by any suitable means such as welding or mechanical fasteners. Thus, it can be seen that the base member 160 and the inclined members 161 of an integral K-shaped cross member structure 122 which interconnects and maintains the main members 121 in a separate parallel relationship. One or more openings 129 (FIGURE 6) are formed on the vertically extending surface of each base member 160 and each inclined member 161, and each of the openings 129 is aligned with the corresponding openings formed in the other members to provide the passage of air and / or fluid conduits, electric lines, and the like used in the operation of the semi-trailer (not shown). Each main member 121 has a pair of crossbar guides 125 mounted on its outer surface by bolts 126. Each crossbar guide 125 is mounted adjacent to a respective one of the front and rear ends of the main member 121. A low friction band 127 is attached to the uppermost surface of each main member 121 by means of recessed fasteners 128, and generally extends the entire length of the main member 121. The web 127 is formed of any suitable low friction material, such as ultra high molecular weight polyethylene. As mentioned in the above, and as best shown in FIGURES 7 and 8, the slide 120 supports the front and rear axle / suspension systems. However, only the front axle / suspension system 130 is shown in the drawings and is described in the present position that the front and rear systems are identical in structure and operation. Further, since the axle / suspension system 130 is suspended from the slider 120, but does not form an integral part thereof, only the major components of the system 130 will be cited to assist in describing the environment in which the slider operates. 120. The axle / suspension system 130 generally includes identical suspension assemblies 131 suspended from each pendant bracket 123A of the pair of front hangers. A reinforcement box 170 is mounted by any suitable means in the open portion of each main member 121, in front of and adjacent each end of the base member 160, to provide additional resistance to the slide 120 for supporting the hanging supports 123A and their assemblies 131 of associated suspension. Each suspension assembly 131 includes a suspension beam 132 that is pivotally mounted to the suspension bracket 123A in a conventional manner. A pneumatic spring 133 is suitably mounted on and extends between the upper surface of the rearmost end of the suspension beam 132 and the main member 121 at a location directly below the outer end of a respective one of the inclined members 161a of the structure 122A of a K-shaped cross member. A crash absorber 134 extends between and is mounted on the suspension beam 132 and the respective inclined member 161. Another component of the suspension assembly 131, mentioned here only for relative fullness, is an air brake 135. An axle 137 extends between and is captured in the pair of suspension beams 132 of the axle / suspension system 130. One or more wheels / tires 138 are mounted on each end of the shaft 137. The slide 120 is movably mounted on the towing chassis (not shown) by slidable engagement of the guide rails 125 with cross-bars 141 generally Z-shaped. and separate parallels (FIGURE 7), which are mounted on and depend on the inner side of the main frame members (not shown) of the trailer chassis. Each low friction band 127 splices the lower surface of the uppermost portion of a respective one of the crosspieces 141 to provide a generally smooth, friction free contact surface for slidable movement of the slider 120 on the towing chassis. The slider 120 is selectively positioned relative to the tow chassis for optimum load distribution and trailer versatility by the retractable pin mechanism 124 which couples the selected ones of the openings 153 formed in the cross members 141 in a manner known to those having Ordinary experience in the truck technique. As discussed in the foregoing, the K-shaped cross member structure 122 of the prior art slide 120 improved over the conventional cross members 22 of the prior art slide designs such as the slide 20. More particularly, the prior art slide 120 utilizes a cross member and location structure to more efficiently support the combined vertical, lateral and longitudinal load conditions experienced by the slide primarily during the movement of the semi-trailer, yet reduces the total weight of the slider of that of the other slides of the prior art by up to about fifteen percent. Specifically, the slides must be constructed so that they can withstand the various loading conditions that a trailer will undergo during the movement of the semi-trailer. Vehicles that contain more than one non-steerable axle, such as semi-trailers, may be subjected to lateral or secondary loads directed through the hanging slide supports.

Also, longitudinal loads can adversely affect a slide. In certain sharp turns known as drag turns, the front axle is dragged sideways in one direction, while the rear axle is dragged sideways in the opposite direction. The resulting helical torsional action or deformation effect of such lateral and / or longitudinal loads on a slide may be important. However, in addition to the lateral and longitudinal loads, the runners must be able to withstand extreme vertical loads imposed through the suspension assemblies and hanging supports. Again, in the slide 20 of the prior art, the cross members 22C and 22F are located directly on the site of the pneumatic spring joints in the main members 21 to provide support and as discussed immediately above, the members 22A , B, D and E cross provide support for the hanging supports 23. The prior art slide 20 and similar designs attempt to control the adverse effect produced by the vertical loads by using rigid and therefore heavy main members 21, and members 22 in cross. Although the configuration of the conventional heavy and rigid cross member optimizes the ability of prior art sliders to support vertical loads, the ability of such prior art slide designs to support lateral and longitudinal loads is less than optimal since the resulting deformation effect on the rigid and heavy slide causes high tension in the joints of the cross members 22 and the main members 21, and ultimately reduces the life of the slide. The prior art slide 120 has shown an improved ability to withstand lateral, longitudinal and vertical loading conditions by utilizing the K-shaped cross member structures 122 and also provides significant weight savings and manufacturing cost over the others prior art slide designs such as the slide 20 due to a reduction in the parts and associated labor required to assemble those parts. The cross members 22A-C and 22D-F of the prior art slide 20 are replaced by the K-shaped cross member structures 122A and 122B, respectively, to achieve such a remarkable improvement covered in the aforementioned US Patent. No. 5,720,489. More particularly, and with reference now only to the cross-shaped structure 122A in the form of a front K since the structure and effect of the back structure 122B are virtually identical, a single base member 160 replaces two cross members 22A, B support the front hanging brackets 123A against vertical loads. The inclined members 161, in combination with the base member 160, provide lateral and longitudinal support to the slide 120 in forming the K-shaped structure or spacer 122A. The inclined members 161 are also positioned to provide vertical support for the pneumatic springs 133. The result has improved the ability of the prior art slide 120 to withstand the combined vertical, lateral and longitudinal loading conditions, while reducing the total weight of the slide. Thus, the slide 120 of the prior art has shown, in relation to other prior art sliders such as the slide 20, improved capacity to withstand lateral and longitudinal loads such as those that can occur when the semi-trailer makes turns of braking and surface drag very divided or find impact of turning with sidewalks and direct impact with potholes. However, the space for improvement in the structure and function of the slide 120 still exists. The improved slider for semi-trailers of the present invention is generally indicated at 220 and is shown in FIGURE 9, and is an improvement over slides 20 and 120 of the prior art. More specifically, although the slider 220 of the present invention is similar in some respects to the slides 20 and 120 of the prior art described in detail in the foregoing and shown in FIGS. 1-8, the slider 220 is different from slides 20 and 120. in certain aspects, thereby contributing to the improved performance of the slide of the present invention over these and other similar prior art sliders. The structural and resultant performance differences between the slide 220 of the present invention and the slides 120 and 20 of the prior art will be described in detail in the following. The slide 220 includes a pair of main members 221, front and rear cross members 222A, B, respectively, front and rear vertical brace structures 210A, B, respectively, a horizontal brace structure 211, front and rear pairs of hanging brackets 223A, B, respectively, for suspending axle / suspension systems, and a retractable pin mechanism 224. Specifically, each main member 221 is an elongated J-beam formed of a metal such as steel or other suitable material. The main members 221 are connected to each other in parallel relation separated by members 222A, B in the front and rear cross and front and rear vertical brace structures 210A, B and the horizontal brace structure 211. The cross members 222A, B, and the brace structures 210 A, B, and 211 are formed of a metal such as steel, aluminum, or other suitable strong material, such as a composite material, an example of which is fiber reinforced polyethylene. of glass.

Each cross member 222 is a generally C-shaped beam that has its open portion facing forward. Each cross member 222 extends between and is attached to each of its ends, preferably by fasteners such as bolts 218, to a reinforcing bracket 219 which in turn is welded to its respective main member 221. In accordance with one of the main features of the present invention, each spacer structure 210A, B includes a pair of inclined members 212 which generally extend transversely. Although the inclined cross members 212 are also each formed of a strong material such as steel or other strong material, they are much lighter than any of the cross members 22 or diagonal members 161 of the sliding structures 20, 120 of the prior art, respectively, described in the foregoing. Each cross member 212 is generally C-shaped with the open portion of one of the cross members facing forward, and the open portion of the other cross member confronting thereafter. Each cross member 212 extends between a respective one of the main members 221 adjacent the pin mechanism 224 and the hanger brackets 223. More particularly, the end of the top or main member of each inclined cross member 212 is preferably soldered to a flange 213 extending internally which in turn is welded to its respective main member 221. The lower end or hanging bracket of each inclined cross member 212 is attached to a front surface of its respective hanger 223 by fasteners 214 such as bolts. Another fastener 215, preferably a bolt, extends through the aligned openings (not shown) formed in a central portion of each cross member 212 and secured thereto by a nut to interconnect the members for added structural integrity. According to another important feature of the present invention, the horizontal brace structure 211 is formed by a pair of cross members 216 extending diagonally. The ends of each cross member 216 preferably are each welded to the respective ones of the main members 221 adjacent to the respective ones of the hanging supports 223A, B, so that the horizontal brace structure 211 extends from the portion most front of the slide 220 and posterior to the central portion of the slide. The diagonal cross members 216 similarly are held together where they intersect by a brace bolt 217 or a weld (not shown). In this way, it can be seen that the cross members 222A, B and the vertical and horizontal brace structures 210A, B and 211, respectively, interconnect and maintain the main members 221 in a separate parallel relationship. Each numeral 212, 222A, B in cross has a plurality of openings formed in its vertically extending surface. The openings 229 are aligned with corresponding openings formed in the other cross members 212, 222A, B to provide passage of air and / or fluid conduits, electrical lines, and the like used in the operation of the semi-trailer (not shown) . Other advantages of the vertical and horizontal brace structures 210A, B and 211 on the cross members 22 of the prior art or the inclined members of the sliders 20 and 120, respectively, will be described in detail in the following. Each main member 221 has a pair of guide rails 225 mounted on its outer surface by bolts 226 adjacent to the respective ones of the hanger brackets 223A and B. A low friction band 227 is attached to the uppermost surface of each main member 221 by means of recessed fasteners 228 and generally extends the entire length of the main member 221. The band 227 is formed of any suitable low friction material, such as ultra high molecular weight polyethylene. As mentioned in the above, and as best shown in FIGURE 11, the slide 220 of the present invention supports the front and rear axle / suspension systems. However, only the front axle / suspension system 230 is shown in the drawings and describes in the present post that the front and rear systems are identical in structure and operation. In addition, since the shaft / suspension system 230 is suspended from the slide 220, but does not form an integral part thereof, only the main components of the system 230 will be cited to assist in describing the environment in which the slide operates of the present invention. The axle / suspension system 230 includes generally identical suspension assemblies 231 suspended from each hanger bracket 223A of the pair of front hangers. A reinforcing box 270 is mounted by any suitable means on the inner side of each main member 221, rear of each end of the horizontal brace structure 211, and adjacent to and on the respective of the hanging brackets 223A, B, to provide additional resistance to the slide 220 to support the hangers 223A, B and their associated suspension assemblies 231. Each suspension assembly 231 includes a suspension beam 232 which is pivotally mounted to the suspension bracket 223A in a conventional manner. A pneumatic spring 233 is suitably mounted on and extends between the upper surface of the rearmost end of the suspension beam 232, or an extension thereof, and the main member 221 at a location directly below the outer end of a respective one of members 222A, B in cross. A shock absorber 234 extends between and is mounted on the suspension beam 232 and the respective cross member 222A, B. Another component of the suspension assembly 231, mentioned here only for relative fullness, is a pneumatic brake 235. An axle 237 extends between and is captured in the pair of suspension beams 232 of the axle / suspension system 230. One or more wheels (not shown) are mounted on each end of the shaft 237. The slide 220 is movably mounted on the trailer chassis (not shown) by sliding engagement of the guide rails 225 with generally Z-shaped cross-members. and separate parallels that are mounted on and depend on the inner side of the trailer chassis in a manner well known to those with experience in semi-trailer technology. Each low friction band 227 splices a respective one of the crosspieces to provide a generally friction free, smooth contact surface for slidable movement of the slider 220 in the trailer chassis. The slide 220 is selectively positioned relative to the trailer frame for optimum load distribution and trailer versatility by the retractable pin mechanism 224 that couples selected ones of the openings formed in the crosspieces (not shown) in a manner known to those who he has ordinary experience in the truck technique and as shown and described in the foregoing for the slides 20, 120 of the prior art. As discussed in the foregoing, an important feature of the present invention is the vertical and horizontal brace structures 210A, B, 211 which replace and improve on the conventional cross members 22 and the inclined members of the sliding designs the prior art. More particularly, the slide 220 of the present invention optimizes the location of the transverse member structure to react more efficiently against secondary or lateral loads, torsional or helical torsional loads, and the reciprocating or longitudinal load conditions experienced by the During the movement of the semi-trailer, it still reduces the total weight of the slide from that of the prior art sliders to approximately fifteen percent and provides a stronger and more efficient slide structure in general. Specifically and as seen in the above in the discussion of slide 120 of the prior art, the runners must be constructed in such a way that they can withstand the various load conditions to which a trailer will be subjected during the movement of the semi-trailer. Vehicles that contain more than one non-steerable axle, such as semi-trailers, are subjected to lateral or secondary loads. Such lateral loads, in the case of driving returns, are directed through the hanging slide supports in opposite transverse directions. Also, the longitudinal loads may adversely affect the slides 20 and 120. The twisting or deformation effect of such lateral and / or longitudinal loads on the slides 20, 120 may be significant, although less important in the slider 120 that has been considered therefore the tip slider, which in the conventional slide 20 of the prior art. However, in addition to the secondary or lateral and oscillating or longitudinal loads, the sliders must be able to withstand extreme vertical loads imposed through the suspension assemblies and hanging supports. Again, the cross members 22C and 22F in the prior art slide 20 are located directly on the site of the pneumatic spring joints in the main members 21 to provide support, and as discussed immediately above, the members 22A , B, D and E cross provide support to the hanging supports. The prior art slide 20 and similar designs attempt to control the adverse effect produced by the vertical loads by using rigid and therefore heavy main members 21 and cross members 22. Although the configuration of the heavy and rigid conventional cross member optimizes the capacity of the prior art sliders such as the slide 20 to support vertical loads, the ability of such prior art slide designs to support lateral and longitudinal loads is less than optimal since the resulting deformation effect on the rigid and heavy slide causes a high tension in the joints of the cross members 22 and the main members 21, and ultimately reduces the life of the slide. Although the sliding 120 that uses the structures 122 of the K-shaped cross member was an improvement and resulted in significant weight and manufacturing cost savings over the prior art slide 20 due to a reduction in the parts and associated labor required to assemble those parts and satisfactorily performing its intended function, the present invention is stronger and more efficiently controls certain helical deflections. In addition, the present invention reacts more efficiently to other loads. For example, when the loads are found by the suspension assemblies 231 of a semi-trailer during operation, the improved slide 220 of the present invention is subjected to concentrated loads that pass through the vehicle suspension assemblies 231 during the operation. operation, and the slide reacts efficiently or dissipates such concentrated loads throughout the entire slide structure. In particular, the combination of structure 210A, B and 211 of vertical and horizontal brace, respectively, allows the dispersion of loads throughout the slide structure adjacent to the front and rear suspension brackets 223A, 223B, respectively, instead of a more limited area adjacent each hanging support as in the slides 20, 120 of the prior art. For example, as a lateral load from one side of the slide 220 pushes a force through some of the cross members 212 and 216 of the vertical and horizontal brace structures 210A, B and 211, respectively, the other of the members on cross 212 and 216 pull forces through the sliding structure. Specifically, the vertical brace structures 210A, B react more efficiently to the lateral loads allowing the elimination of the traditional hanging bracket cross members and the diagonal bracing of the hanging bracket, thereby reducing weight and cost while increasing the durability. The horizontal brace structure 211 also reacts more efficiently against helical or deformation torsional loads, lateral loads, swing loads and reciprocating loads. This reduces the deflections of the main crosspieces 221 and all the components attached to the main cross members, such as the frame hangers 223 and the suspension assemblies 231, thereby providing a stronger and lighter design. Also, the vertical brace structures 210A, -B and the horizontal brace structures 211 are combined and cooperate to share and thereby react more efficiently against lateral loads and reciprocating loads, similarly reducing the deflections of the main crosspieces and all the components attached to the main crossbars, also in this way adding to the resistance of the slide in a lightweight and less expensive design package. The slider 220 of the present invention achieves the improved results described above because it efficiently locates the new vertical and horizontal strut structures 210A, B and 211, respectively, in locations where the load vectors of the lateral loads and the deformation loads they happen The prior art sliders 20, 120, in comparison and contrast, in many cases locate their cross members 22 or frame structures 122 away from these load vectors so that unwanted deflections and elevators of tension are much more prevalent . For example, the K-shaped cross member structures 122 are not activated by lateral loads and thus do not dissipate those charges. The spacer slide 220 of the present invention results in less cost in the manufacturing process, faster assembly times and a stronger and lighter slide than the prior art sliders. It is understood that other embodiments of the spacer runner 220 can be made only with the horizontal spacer structure 211 or only with one or more structures' 210A, Vertical brace B, and with varying numbers of members 222 crosswise and still showing advantages over sliders, 20, 120 of the prior art. However, the preferred embodiment of the present invention is to use vertical and horizontal braces structures 210A, B and 211, respectively, with a pair of cross members 222. It is further understood that means other than the guide rails 225 can be used to movably connect the towing links. Similarly, it is further understood that means other than the retractable pin mechanism 224 shown and described herein may be used in conjunction with the present invention to selectively position the mobile sub-frame of the present invention relative to the trailer. In addition, the brace structures 210A, B, 211 may have different configurations to a cross or "X", such as an integral integral rectangular plate shape, without affecting the general concept of the present invention. It should be noted that the present invention also contemplates the use of inventive concepts of the mobile slide or secondary frame structure in stationary primary frame structures, having two or more axes, of certain types of heavy-duty vehicle trailers, for example , platform trailers and some tank trailers. It also contemplates the application of the inventive concepts described in the foregoing on non-mobile subframes of the type found in bulk cargo trailers. Therefore, the improved slide for semi-trailers is simplified, provides an effective, safe, economical and efficient structure that achieves all the objectives listed, stipulates to eliminate difficulties encountered with previous semi-trailer slides and solves the problems and obtains new results in The technique. In the previous description, certain terms have been used for brevity, clarity and understanding; but no unnecessary limitation will be implied from them beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly interpreted. In addition, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described. Now having described the features, discoveries and principles of the invention, the manner in which the improved trailer slider is constructed, accommodated and utilized, the characteristics of the construction and layout and the advantageous, novel and useful results obtained; the novel and useful structures, devices, elements, arrangements, parts and combinations are set forth in the appended claims.

Claims (12)

1. CLAIMS 1. A frame structure for a vehicle trailer, the frame structure characterized in that it includes: a) a pair of longitudinally extending and elongated parallel main members separated; b) a pair of spaced transverse parallel cross members extending between and joining the main members; and c) a horizontally disposed strut structure extending between and attaching to the main members.
2. 2. The frame structure according to claim 1, characterized in that at least one vertically disposed brace structure extends between and joins the main members and a pair of hanging brackets which are attached to and depend on the main members.
3. 3. The frame structure according to claim 2, characterized in that the brace structures horizontally and vertically arranged each have a generally cross-shaped or X shape. The frame structure according to claim 3, characterized in that a pair of vertically arranged strut structures extends between and joins the main members and the hanging supports; in which each of the vertically arranged strut structures includes a pair of diagonal cross members; and in which each of the vertical diagonal cross members extends between and is mounted on the respective main members and the hanging supports. The frame structure according to claim 3, characterized in that a reinforcement box is attached to each of the adjacent main members a and subsequently of each of the ends of each of a pair of diagonal cross members of the horizontally arranged brace structure; and in which each of the ends of each of the horizontal diagonal cross members is mounted on the main members adjacent to the respective ones of the hanging supports. The frame structure according to claim 2, characterized in that a reinforcing bracket is attached to each of the main members adjacent to each of the ends of each of the transverse cross members; and in which each end of each of the transverse cross members is joined to a respective one of the reinforcing clamps. The frame structure according to claim 6, characterized in that at least one hanger bracket is attached to and depends on each of the main members to mount at least one axle / suspension system in the frame structure; and in which a pneumatic spring of the axle / suspension system is mounted on and depends on each of the main members adjacent to a respective one of the ends of a respective one of the transverse cross members. The frame structure according to claim 7, characterized in that an upper end of each of a pair of shock absorbers of the axle / suspension system is joined to a respective one of the transverse cross members. The frame structure according to claim 1, characterized in that the frame is a subframe structure movably mounted on the separate parallel elongate crosspieces mounted on the bottom of the trailer; wherein the main members each include means for movably coupling a selected one of the trailers of the trailer; and wherein the sub-frame structure includes means for selectively positioning the sub-frame structure relative to the trailer frame to facilitate load distribution. The frame structure according to claim 9, characterized in that the means for movably coupling the respective of the towing links a pair of separate crossbar guides mounted on an outer surface of each of the main members; wherein the cross-member guides slidably engage the towing cross members; and in which a low friction material is generally mounted over the entire uppermost surface of each of the main members to facilitate sliding movement of the subframe structure on the towing links. The frame structure according to claim 9, characterized in that the means for selectively positioning the subframe structure relative to the trailer is a retractable pin mechanism. The frame structure according to claim 9, characterized in that the sub-frame structure is formed of steel.