Adjustable load bar

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.

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.

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.