Abstract:
An improved load securing bar for the transport industry includes telescoping tubes, the position of which can be adjusted relative to each other to control the length of the load securing bar for different size environments and different loads. The load securing bar preferably includes both a rough adjustment mechanism for relatively long length adjustments and a fine adjustment mechanism for more precise length adjustments. The fine adjustment mechanism includes a gear and rack assembly which are housed within the telescoping tubes.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to retaining devices to prevent the shifting of loads within an enclosed space, and more particularly, to an improved load retaining device for vehicles, particularly trucks, to prevent shifting of the load of the truck while in transit. 
     2. Summary of Related Art 
     Cargo within trucks, unless it substantially fills the available space, tends to shift position during transit, in response to acceleration, deceleration and/or bumps or other vibrations. Typically during loading, trucks are not totally filled, thus resulting in the shifting problem. While mechanisms such as cargo webs are available for retaining cargo, such webs are unwieldy and are especially unsuitable for situations where frequent loading and unloading occur. 
     One type of extendable bracing bar is a hydraulic bracing bar. Hydraulic bracing bars have proven to be unsuitable for most applications due to occurrence of leakage and poor performance in cold temperatures. 
     Extendable bracing bars are well known in the art of load bracing in the trucking industry. Many of these bars provide for a large imprecise adjustment of the bar length and then a shorter, more precise adjustment to optimize the bar length for the retaining purposes. An example of such a bar is found in U.S. Pat. No. 5,378,095, which describes a load securing device for holding cargo within trucks against shifting during motion of the truck. The bar of U.S. Pat. No. 5,378,095 provides a gross adjustment and a final adjustment via a pinion gear engaged with a rack. The final adjustment structure does not utilize springs so as to increase the durability of the device. This bracing bar has not found its way into commercial use. 
     A disadvantage of this bracing bar is that the final adjusting mechanism is exposed to the environment. As such, the mechanism is vulnerable to damage from accidental contact or through added exposure to contaminants during normal usage. Additionally, there can be danger to the user or to the cargo from the exposed adjusting mechanism. It would be preferable to minimize the possibility of damage to this mechanism. 
     Therefore, it is an object of the present invention to provide an improved load securing device. 
     It is a further object of the present invention to provide a load securing device which minimizes the possibility of damage or undue wear to the fine adjustment mechanism. 
     Yet another object of the invention is to provide a load securing bar where the operator and the load are not exposed to the mechanism of the gear and rack. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a load securing bar, including telescoping tubes, with structure for both rough adjustments and more precise adjustments, wherein most of the structure for the more precise adjustments is contained inside the hollow main tube. Specifically, the gear and rack are both within tubes. Preferably, the load bar is designed with the structure for rough adjustment at one end and the structure for precise adjustment at the other. In this manner, the structure is not exposed to excessive wear and thus can result in an increased service life of the bar. In a typical application, a vehicle may use about ten load bars to adequately restrain the cargo. 
     The ends of the bar of the invention may be equipped with structure for bracing the bar in the vehicle, preferably pivotable feet or pads. The bar can preferably include a main tube and second and third tubes axially displacable within the main tube. The fine adjustment mechanism can make fine adjustments of the position of the second tube with respect to the main tube and the rough adjustment mechanism can adjust the position of the third tube with respect to the main tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in light of the accompanying drawings in which: 
     FIG. 1 shows a profile view of a load bar according to the present invention; 
     FIG. 2 shows an expanded cut away view of the load bar of FIG. 1 showing the internal mechanism; 
     FIG. 3 shows a cross section of section A—A in FIG. 1; and 
     FIG. 4 shows a cross section of section B—B in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, FIGS. 1 and 2 illustrate a load bar in accordance with the present invention, including a main tube  1 . A second tube  2  is positioned to slide in the main tube  1 . In a preferred embodiment of the present invention the main tube  1  is substantially hollow, although other embodiments of this main tube may be possible, wherein parts of the main tube are not hollow. A toothed track or rack  3  is connected to the second tube  2  and is positioned to slide along the inner surface of the main tube  1  along with the second tube  2 . Preferably, the toothed track  3  can be pinned to the second tube  2 , as best seen in FIG.  2 . An axle  4  for a gear  5  is rotatably fixed in the main tube  1 . The gear is preferably designed with a first set of teeth  27  and a second set of teeth  28 . The second set of teeth  28  of the gear  5  are preferably at a sharper angle than the first set of teeth  27  and are adapted to cooperate with a pawl  8 . The first set of teeth  27  of the gear  5  are designed to mesh with the teeth of the toothed track  3  to displace the toothed track  3 , along with the second tube  2 , relative to the main tube  1  upon rotation of the gear  5  in the direction of rotation  6 . This rotation then displaces the second tube  2  in the direction  7 . To minimize wear of toothed track  3  and the main tube  1  when the toothed track  3  is sliding with respect to the main tube  1 , at least one low friction pad  23  can be positioned on the toothed track  3  to slide along the inside of the main tube  1 . This low friction pad  23  can thus substantially prevent direct contact of the toothed track  3  with the interior of the main tube  1 . Preferably, a pair of spaced apart pads  23  are used. 
     In a preferred embodiment of the present invention, the main tube  1  has a substantially square or rectangular cross section. Preferably, the at least one low friction pad  23  can be made of durable, low friction plastic, and the toothed track  3  can preferably be made of anodized aluminum. In at least one preferred embodiment of the present invention, the sizes and teeth ratio of the first set of teeth  27  of the gear  5  and the toothed track  3  can be designed so that one complete rotation of the handle  19  and gear  5  results in a displacement of the second tube  2  with respect to the main tube  1  of about three inches. 
     The load bar also includes a mechanism to allow rotation of the gear  5  to extend the second tube  2  with respect to the main tube  1 , but to prevent rotation of the gear  5  in the direction opposite the direction of rotation  6 . In the embodiment shown, the pawl  8  is positioned so that a tooth  9  of the pawl  8  selectively engages the second set of teeth  28  of the gear  5 . A spring  10  tensions the pawl  8  to intermesh the tooth  9  with the second set of teeth  28  of the gear  5 . The interaction of the second set of teeth  28  of the gear  5  with the tooth  9  of the pawl  8  allows the gear  5  to rotate by a ratcheting action in the direction of rotation  6 , but prevents rotation in the opposite direction. An end  11  of the pawl  8  extends through a slot  12  in the main tube  1 . By displacing the end  11  of the pawl  8 , the tooth  9  can be disengaged from the gear  5 , allowing the second tube  2  to move opposite the direction  7 . In the embodiment shown, the end  11  of the pawl  8  can be displaced by hand, although other mechanisms for displacing the end  11  are possible within the scope of the present invention. Similarly, the illustrated embodiment shows a tension spring  10  tensioning the pawl  8 . Other embodiments of this mechanism are possible within the scope of the present invention. For example, a V or L shaped plate spring can be designed in such a manner as to tension the pawl  8  with respect to the gear  5 . For example, the pawl  8  could be positioned to engage the gear  5  from the opposite side from what is shown herein. In this case, the V or L shaped spring could engage the end  11  of the pawl  8  and push it away from the outside of the main tube  1  which, in the example described, would engage the tooth  9  of the pawl  8  with the gear  5 . In the embodiment described, the pawl  8  could release the gear  5  by pressing the end  11  of the pawl  8  toward the main tube  1 . Other constructs of this mechanism are also possible within the scope of the present invention. 
     In the preferred embodiment illustrated in FIG. 1, a third tube  13  is provided which is a part of the rough adjustment structure. A pin  14  is operatively connected to the third tube  13 , and engages with one of a series of holes  15  in the main tube  1 . The series of holes  15  are axially displaced from one another to allow a displacement of the third tube  13  with respect to the main tube  1 . The third tube  13  thus telescopes within the end of the main tube  1  opposite the second tube  2 . This allows the load bar to be easily extended to a rough distance before the fine adjusting mechanism is utilized to insure the load is adequately supported. 
     FIG. 4 illustrates a detail view of the rough adjustment mechanism. The pin  14  is attached to an end of a plate spring  16  which is positioned inside the third tube  13 , and extends through a hole  17  in the wall of the third tube  13 . The opposite end of the plate spring  16  is secured to the inside of the third tube  13 . In the embodiment shown, the plate spring  16  is held by a rivet  18 , but other conventional methods of fastening, such as welding, are possible in conjunction with embodiments of the present invention. By the mechanism shown, the pin  14  can be displaced from the hole  15  in the main tube  1  in which it is engaged, and then the third tube  13  can be moved to align with a different one of the plurality of holes  15 . This allows a rough adjustment of the length of the load bar. 
     FIG. 1 also shows a handle  19  which is secured to the axle  4  and the gear  5 . This handle  19  can be used to adjust the fine position of the load bar by turning the gear  5  in the direction of rotation  6  to displace the second tube  2  in the direction  7 . The pawl  8  prevents the gear  5  from turning opposite the direction of rotation  6 . The connection of the handle  19  to the gear  5  can be a simple connection which always rotates with the gear  5 , or the connection can be designed so that it does not rotate with the gear  5  when the gear  5  is allowed to rotate opposite the direction of rotation  6 . This choice may be preferred for safety when disengaging the load bar. 
     FIG. 1 also illustrates  2  optional foot members or pads  20  disposed at opposite ends of the load bar. As shown, one foot member  20  is connected to the second tube  2  and the other foot member  20  is connected to the third tube  13 . Preferably, the foot members  20  are connected by a ball joint  21  to their respective tubes ( 2 ,  13 ), which allows the foot members  20  to pivot with respect to the tubes. This can help to insure a secure positioning of the load bar even when the opposing surfaces it is positioned between are not perfectly parallel to each other. If a load bar according to the present invention was constructed without the rough adjustment mechanism and the third tube  13 , the pads  20  could be placed on an end of the second tube  2  and the end of the main tube  1  opposing the second tube  2 . 
     FIG. 3 illustrates a cross section of the main tube  1  at the gear  5 . In a preferred embodiment, the axle  4  can be held in position by bearings  22  mounted in apertures in the main tube  1 , preferably sealed roller bearings, to securely hold the gear  5  in the main tube  1 , while allowing rotation of the gear  5 . Preferably the end of the axle  4  of the gear  5  can be secured with a screw  24  and washer  25  combination. FIG. 3 also illustrates a pair of pins  26 , which secure the gear  5  to the axle  4 . 
     Use of the invention, as described above, can be carried out as follows. The rough adjustment mechanism can simply be used by depressing the pin  14  through the hole  15  in main tube  1 . The third tube  13  can then be moved to the appropriate position so that the pin  14  can extend through a different one of the holes  15 . This allows rough adjustment of the length of the load bar in discreet increments. The fine adjustment mechanism can then be used to make precise adjustments of the length to the desired length. By turning the handle  19  the gear  5  rotates and the pawl  8  disengages from the tooth of the gear  5  with which it is engaged and engages with the next tooth, displacing the second tube  2  with respect to the main tube  1 , thus increasing the length of the load bar. This continues as the handle  19  is being turned. When the desired length is reached, the tooth  9  of the pawl  8  engages the gear  5  to hold the bar at that length. To remove the bar, the release of the pawl  8  is engaged. In the illustrated embodiment, the end  11  of the pawl  8  projecting through the slot  12  in the main tube  1  is depressed, against the force of the spring  10 , which releases the tooth  9  of the pawl  8  from the teeth of the gear  5 . This allows the gear  5  to rotate opposite the direction of rotation  6 , decreasing the length of the load bar. The rough adjustment mechanism can be shortened in the same manner that it is lengthened, by depressing the pin  14 , and manually adjusting the relative positions of the main tube  1  and the third tube  13 . 
     The inventive load bar described thus has a simple and efficient operation, and is improvement over known load bars. By locating of the gear and rack assemblies inside the tubes, the present invention makes a more compact load bar and insures that there are no exposed gears. Thus the mechanism is protected from undue wear, and also users and cargo of the vehicle are not exposed to the gear mechanism. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.