Abstract:
A cargo restraint system for retaining a cargo pallet. The cargo restraint system comprising a frame having a receiving channel and a pallet latching member. The pallet latching member is rotatably coupled at a first end to the frame for pivotal movement between a stowed position and a retaining position. The latch member includes a pair of camming surfaces that are engageable with the cargo pallet during an overriding movement of the cargo pallet, which forces the pallet latching member into the stowed position. The pallet latching member has an overall maximum width that is less than a width of the receiving channel of the frame to eliminate any wing-like feature and minimize the potential for damage to the pallet latching member caused by inadvertent snagging of the pallet latching member by the cargo pallet.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to cargo restraints for securing a cargo container or pallet and, more particularly, relates to an improved cargo restraint that minimizes the likelihood of damage caused by snagging of the cargo pallet on the cargo restraint.  
         BACKGROUND OF THE INVENTION  
         [0002]    As is well known in the art, cargo restraints are commonly used in aircraft and other vehicles to secure cargo containers or pallets to prevent excessive movement during transport. Typically, cargo containers are loaded, handled, and aligned into their approximate position within the compartment of the aircraft. As the cargo container is positioned into its final position, a retractable cargo restraint is lifted from a position generally within the floor into an engaged and locked position. The cargo restraint overlaps a flange-like portion or pocket of the cargo container and secures the cargo container relative to the floor to minimize vertical and horizontal movement thereof. However, it is often necessary for these cargo restraints to be overrideable. That is, these restraints should be capable of being deflected downwardly to enable a cargo pallet to slide thereover.  
           [0003]    As illustrated in U.S. Pat. No. 5,011,348, which is commonly assigned and the disclosure of which is hereby incorporated by reference, a cargo restraint is shown having a wing-type camming feature. As best seen in FIG. 1 herein, the cargo restraint  200  is pivotally mounted to the longitudinal members  202  of a frame  204 . The cargo restraint  200  includes a central base  206  having a tapered extension  208  on each forward and aft side. The tapered extension  208  has an upwardly sloping camming surface  210 , which causes the cargo restraint  200  to retract downwardly into the frame  204  upon engagement by a cargo body. As can be appreciated from the figure, tapered extensions  208  have the aforementioned wing-type configuration. However, this wing-type configuration may not afford maximum protection against snagging or other contact with the cargo pallet.  
           [0004]    Cargo pallets are often covered with a cargo netting which drapes over the sides and down to the floor of the cargo area. This cargo netting is particularly susceptible to snagging on tapered extensions  208 . Potentially, the cargo netting may cause damage to the cargo restraint or, in some situations, cause damage to the underlying frame structure. Damage to the cargo restraint and/or frame structure may lead a delay in scheduling of the aircraft in order to accommodate the necessary time for repairs. It should be appreciated, that any delay in flight scheduling may equate to a potential for loss revenue.  
           [0005]    Moreover, this wing-type cargo restraint typically requires expensive forging dies for its manufacture and, furthermore, requires an exorbitant amount of machining time to create the final configuration. Still further, the sheer size of the wing-type cargo restraint requires additional material, which increases the cost of manufacture.  
           [0006]    Accordingly, there exists a need in the relevant art to provide an overrideable cargo restraint that is capable of minimizing the likelihood of snags and/or inadvertent damaging contact between the cargo pallet and the cargo restraint. Furthermore, there exists a need in the relevant art to provide an overrideable cargo restraint that eliminates or at least minimizes the existence of overhanging features, which have the potential of being snagged and/or damaged. Still further, there exists a need in the relevant art to provide a cargo restraint that is capable of overcoming the disadvantages of the prior art systems.  
         SUMMARY OF THE INVENTION  
         [0007]    In accordance with the broad teachings of the present invention, a cargo restraint system for retaining a cargo pallet having an advantageous design is provided. The cargo restraint system comprises a frame having a receiving channel and a pallet latching member. The pallet latching member is rotatably coupled at a first end to the frame for pivotal movement between a stowed position and a retaining position. The latch member includes a pair of camming surfaces that are engageable with the cargo pallet during an overriding movement of the cargo pallet, which forces the pallet latching member into the stowed position. The pallet latching member has an overall maximum width that is less than a width of the receiving channel of the frame to eliminate any wing-like feature and minimize the potential for damage to the pallet latching member caused by inadvertent snagging of the pallet latching member by the cargo pallet.  
           [0008]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limited the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]    [0010]FIG. 1 is a perspective view illustrating an overrideable cargo restraint system having wing-type camming surfaces according to the prior art;  
         [0011]    [0011]FIG. 2 is an environmental view illustrating an aircraft cargo area employing a plurality of overrideable cargo restraint systems according to the principles of the present invention;  
         [0012]    [0012]FIG. 3 is a perspective view illustrating the cargo restraint system according to the principles of the present invention with the retaining member in a raised or retaining position;  
         [0013]    [0013]FIG. 4 is an enlarged plan view illustrating the retaining member of the present invention in the raised position;  
         [0014]    [0014]FIG. 5 is a side view, with portions removed for clarity, illustrating the retaining member in a stowed and locked position;  
         [0015]    [0015]FIG. 6 is a perspective view illustrating the retaining member of the present invention; and  
         [0016]    [0016]FIG. 7 is a partial cross-sectional view taken along line  7 - 7  of FIG. 4.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0018]    Referring to FIGS.  2 - 7 , a cargo restraint system  10  is provided for latching and unlatching cargo containers or pallets in a quick and efficient manner. Cargo restraint system  10  includes a frame or base structure  12  that is adapted to be received within a fore-and-aft track  100  formed in the flooring of an aircraft or cargo vehicle  102 , or possibly a railroad car or truck. Such fore-and-aft tracks  100  are of conventional design and, thus, in the interest of brevity, they will not be described in detail herein. Furthermore, in the interest of brevity, cargo restraint system  10  of the present invention will be described in connection with an aircraft cargo area  104 . However, it should be understood that the principles of the present invention are equally applicable to other applications, such as in trucks, railroad cars, and the like.  
         [0019]    Cargo container  106  is typically loaded into cargo area  104  of aircraft  102  using various motor driven wheels and/or casters to enable cargo container  106  to be efficiently moved throughout cargo area  104 . Once cargo container  106  is properly aligned in the cargo area, a plurality of cargo restraint systems  10  are used to retain or secure cargo container  106  in place during transport. Thus, cargo container  106  is prevented from moving laterally by cargo restraint system  10 .  
         [0020]    Cargo restraint device  10  is commonly mounted within tracks  100  of cargo area  104  in pairs to cooperate to retain each lateral side of each cargo container  106 . However, it should be understood that a single cargo restraint system  10  could be used on each lateral side of cargo container  106  depending on the holding capacity required.  
         [0021]    Referring now to FIGS.  3 - 7 , cargo restraint system  10  includes base structure  12 , a pair of T-section studs  14  extending from the planar undersurface of base structure  12 , optional roller elements  16 , and a latching or retaining member  18 . Each T-section stud  14  is adapted to be received within and retained by a channel (not shown) formed in tracks  100  of the cargo area floor. Base structure  12  is then secured or otherwise locked into engagement with tracks  100  to prevent the relative movement of cargo restraint system  10  relative to tracks  100 .  
         [0022]    Roller elements  16  are each adapted to support and guide cargo container  106  while it is moved across cargo restraint system  10 . To this end, each roller element  16  is pivotally journaled to base structure  12  via a roller axle  20 . As can be appreciated from the figures, roller elements  16  are oriented such that they provide a roller support for cargo container  106  as it moves longitudinally within the aircraft cargo area.  
         [0023]    As best seen in FIG. 3, retaining member  18  is pivotally coupled to base structure  12  via a pivot axle  22 . Specifically, as seen in FIGS.  4 - 6 , retaining member  18  is generally triangularly shaped and includes a pair of bifurcated legs  24  each having a bore  26  coaxially formed therethrough. Similarly, base structure  12  includes a pair of sidewalls  28  each having a bore  30  coaxially formed therethrough. Bores  26  of retaining member  18  and bores  30  of base structure  12  are adapted to receive pivot axle  22  therethrough to provide a pivoting relationship between retaining member  18  and base structure  12 . According to the present embodiment, pivot axle  22  includes retaining devices  32 , such as cotter pins, to permit the simple and reliable installation and retention of pivot axle  22  within bores  26 ,  30 .  
         [0024]    Still referring to FIGS.  4 - 6 , retaining member  18  further includes a cargo pallet retaining flange  34 . Cargo pallet retaining flange  34  generally includes an extension  36  that extends from a main body  39  of base structure  12 . Extension  36  of cargo pallet retaining flange  34  generally includes a guide surface  38 , which engages a vertical surface of cargo container  106  when retaining member  18  is in a raised position. Furthermore, guide surface  38  transitions into a cargo retaining surface  40 , which is adapted to engage and retain a top surface of cargo container  106 . Cargo retaining surface  40  generally transitions into a nose portion  42  and a hook portion  44  along a back side of retaining member  18 . Hook portion  44  generally includes a depression  46  in which a locking member engages to retain retaining member  18  in a stowed position. The locking member will be described in more detail below. Hook portion  44  and depression  46  generally transition into a generally flat backside surface  48  that extends rearward to bifurcated legs  24 .  
         [0025]    As best seen in FIG. 6, retaining member  18  further includes a pair of camming surfaces  50 . The purpose of camming surfaces  50  is to receive or engage cargo container  106  when cargo container  106  is being loaded on or unloaded from the aircraft. As described above, cargo container  106  is moved within cargo area  104  of aircraft  102  along roller elements  16  in a direction that is generally perpendicular to the direction of rotation of retaining member  18 . As cargo container  106  contacts camming surface  50 , cargo container  106  causes retaining member  18  to translate or rotate in a first or downward direction whereby retaining member  18  is generally received within a channel  52  of base structure  12  in a stowed position.  
         [0026]    More particularly, as best seen in FIGS. 4 and 7, camming surfaces  50  generally include a pair of sidewalls  54  (FIG. 7), which transition into generally flat backside surface  48  via a radius or curve  56 . Radius  56  is generally aligned along lines A-A so as to create camming surfaces  50  in a generally converging orientation that extends generally from bifurcated legs  24  to cargo pallet retaining flange  34 . This converging or inwardly directed direction of camming surfaces  50  enables cargo container  106  to approach from a side of retaining member  18  and engage camming surface  50  such that a portion of the resultant force causes retaining member  18  to translate downwardly, thereby allowing cargo restraint system  10  to act in a overrideable manner.  
         [0027]    Cargo restraint system  10  further includes a biasing member  58 , such as a torsion spring, which is generally located about pivot axle  22 . Biasing member  58  includes a first leg  60  which is received within a slot  62  formed within retaining member  18  between bifurcated legs  24 . Biasing member  58  includes a second leg  64  that engages a cross-member  66  that extends between sidewalls  28  of base structure  12 . Biasing member  58  is adapted to bias retaining member  18  in the raised or retaining position (FIG. 3). In this retaining position, retaining member  18  engages a flange or corner of cargo container  106  such that guide surface  38  is generally adjacent to a vertical surface of the flange of cargo container  106  and cargo retaining surface  40  is generally adjacent to a horizontal surface of the flange of cargo container  106 .  
         [0028]    As best seen in FIGS. 4 and 5, cargo restraint system  10  further includes a locking device  68  used for locking or securing retaining member  18  in a lowered or stowed position. Specifically, as seen in FIG. 8, locking device  68  includes a generally U-shaped member  70  that is pivotally attached within channel  52  of base structure  12 . U-shaped member  70  is pivotally attached to base structure  12  via a pair of brackets  72 . In operation, retaining member  18  is pivoted downward into the stowed position and held in that position as locking device  68  is rotated upward so as to engage an upper section  74  of U-shaped member  70  with depression  46  of retaining member  18 . Once upper section  74  engages depression  46 , retaining member  18  may be released such that the biasing force of biasing member  58  causes retaining member  18  to pivot upward and against locking device  68 . This arrangement secures retaining member  18  within the stowed position.  
         [0029]    As best seen in FIGS. 3 and 4, it is important to note that cargo restraint system  10  of the present invention does not include any wing-type feature that may be susceptible to being snagged or otherwise caught by cargo container  106  or netting within cargo area  104  of aircraft  102 . Specifically, as can be seen from the figures, retaining member  18  generally defines a maximum overall width B (FIG. 4) that is less than the internal width between sidewalls  28  of base structure  12 , generally indicated as dimension C (FIG. 4). Accordingly, such ability to retain the overriding function of the retaining member while eliminating the disadvantage of the wing-type feature, enables the cargo restraint system  10  of the present invention to minimize the likelihood of damage to the retaining member, base structure  12 , and/or cargo flooring of aircraft  102 , which may be caused by the inadvertent snagging or contact of the retaining member by cargo container  106 . As described above, such inadvertent contact or snagging may cause damage to various parts of the cargo restraint system, which could lead to a down time of the aircraft.  
         [0030]    The cargo restraint system, according to the principles of the present invention, may be used in a wide variety of cargo restraint applications. For example, the cargo restraint system of the present invention may be used in any 1¼″ cargo system which could be used in the Boeing 717, 727, 737, and 757 or in the DC-9, MD-80, and MD-90. Furthermore, with minor dimensional modifications, the cargo restraint system of the present invention may also be used in any 1¾″ system which could be used in the Boeing 747, 767, and 777 or in the DC-10 and MD-11.  
         [0031]    In addition to the advantage of the present invention set forth above, it should be appreciated that the cargo restraint system of the present invention allows for numerous advantages with regard to the reduction in the size of the retaining member, which equates to a reduction in material use and the size of any forging dies. Moreover, the cargo restraint system of the present invention requires less machining time relative to the wing-type design since a lesser portion of the retaining member includes such camming surfaces.  
         [0032]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.