Abstract:
A cargo container hold down device that includes a latch and spring used in a housing defined by a base that forms a surface thereabout on which cargo container corner fittings rests in the applied relation on the container relative to the supporting structure or platform involved, further including a bottom end that interfaces with a deck or vehicle structure for retention of the hold down device so the opposite side of the hold down device is allowed to automatically engage and disengage with a cargo container corner fitting as necessary to achieve proper handling and transport of cargo containers, the device using a latch on a pin, the pin carried in a pocket such that the latch force varies as a function of container position and movement, thereby enabling the use of a single spring in a low profile lock.

Description:
CLAIM OF PRIORITY 
   Priority is claimed based on U.S. Provisional Application Ser. No. 60/310,152 filed Aug. 3, 2002, entitled “Latch Device for Securing Cargo Containers” and having the same inventor identified herein. 

   BACKGROUND OF THE INVENTION 
   The invention relates to container securement devices, and more particularly, to improvements in cargo container securement devices of the type that provide automatic securement and release of a cargo container. The device is mountable on a deck or frame of a vehicle or similar surface as desired so that the device can be adapted to different load conditions including a different mix of containers of different length and the like. 
   This latch device can be used to hold a cargo container onto a vehicle deck such as a railroad car deck. The device can be adapted to hold two cargo containers together such as in the case of double stacking containers. Four latch devices are used to fasten the four corner castings or fittings of a cargo container to a vehicle deck or similar surface. The container&#39;s four bottom corner fittings are brought into contact with the top end of the latch device, thereby sliding over the top of the housing and engaging the protruding latch. A cargo container can be removed when the bottom lip of the corner fitting or casting contacts the concave underside of the upper portion of the latch and overcomes the latch&#39;s resistance while the container is being pulled off the housing. 
   A latch device that may be used wherever the present device can be used is illustrated in U.S. Pat. No. 5,570,981. U.S. Pat. No. 5,570,981 is incorporated herein by reference. The present latch device has fewer parts than what is illustrated in U.S. Pat. No. 5,570,981. The present latch device only has one internal resilient spring, whereas the device in U.S. Pat. No. 5,570,981 has two internal resilient springs. One spring of U.S. Pat. No. 5,570,981 may use a material whose stiffness varies and changes with temperature more than a metal type material. Spring stiffness is directly related to the device&#39;s engaging and releasing forces of the cargo container. With a single spring made of metal, the spring stiffness rate does not vary as greatly as with a second material of a second spring. The elimination of the second spring permits the engaging and releasing of cargo containers with the desired force over a greater temperature range. 
   Also, the sheer block of the housing is larger in the present invention allowing room for a larger latch. A larger latch can be stronger and may have an increased service life. The larger latch due to the taller housing can handle larger loads. 
   The larger latch in combination with the use of only one spring allows greater ability to adapt the latch of the present invention. The shape of the contact and pivot surfaces of the latch&#39;s leg may be tailored to create various embodiments with a greater range of container engagement and release features. 
   BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT 
   A device for securing cargo containers to a vehicle deck or similar surface comprising a housing containing a latch mechanism that extends outwardly from the housing to engage a cargo container corner casting. The other side of the housing has a flat base that is tailored to interface with a vehicle deck or similar surface. 
   Where a cargo container is to be secured to a deck or frame of a vehicle or similar surface, the base of the housing is oriented and fastened in such a manner as to prevent its removal from the deck or vehicle. Welding and using fasteners are examples of appropriate fastening techniques. The appropriate corner fitting of the cargo container is brought into contact with the exposed end of the device latch mechanism that extends outwardly from the housing to engage the cargo container corner casting and secure it to the deck or frame of a vehicle. When appropriate force is exerted to pull the cargo container off of the deck, the devices latch mechanism that extends outwardly from the housing will automatically retract into the devices housing allowing the cargo container to be removed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a frontal elevational view of the latch device for cargo containers. 
       FIG. 2  is a side elevational view of the latch device for cargo containers. 
       FIG. 3  is a back elevational view of the latch device for cargo containers. 
       FIG. 4  is a top plan view of the latch device for cargo containers. 
       FIG. 5  is a bottom plan view of the latch device for cargo containers. 
       FIG. 6  is a sectional side elevational view of the housing for the latch device. 
       FIG. 7  is a side elevational view of the latch for the latch device. 
       FIG. 8  is a sectional side elevational view showing the positions of the latch device&#39;s internal components just prior to the cargo container&#39;s corner fitting engaging with the device. 
       FIG. 9  is a sectional side elevational view showing the positions of the latch device&#39;s internal components partially retracted into the devices housing while the cargo container&#39;s corner fitting engaging onto the device. 
       FIG. 10  is a sectional side elevational view showing the positions of the latch device&#39;s internal components fully retracted into the devices housing just after the cargo container&#39;s corner fitting has been engaged onto the device. 
       FIG. 11  is a sectional side elevational view showing the positions of the latch device&#39;s internal components while the cargo container&#39;s corner fitting is engaged with the device. 
       FIG. 12  is a sectional side elevational view showing the positions of the latch device&#39;s internal components just prior to the cargo container&#39;s corner fitting being removed from the device. 
       FIG. 13  is a sectional side elevational view showing the positions of the latch device&#39;s internal components during partial removal of the cargo container&#39;s corner fitting from the device. 
       FIG. 14  is a sectional side elevational view showing the positions of the latch device&#39;s internal components during partial removal of the cargo container&#39;s corner fitting from the device. 
       FIG. 15  is a sectional side elevational view showing the positions of the latch device&#39;s internal components retracted into the devices housing just after the cargo container&#39;s corner fitting has been removed from the device. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The latch device  10  includes a housing  11 , a latch  12 , a pin  13 , a spring  14  and two side screws  15  and  37 . One side screw  15  or  37  is on each side of housing  11 . An assembled frontal view of device  10  is shown in FIG.  1 . An assembled side lateral view of device  10  is shown in FIG.  2 . The housing  11  has a base bottom  16  that interfaces with the deck or vehicle or similar surface. The housing  11  has a base  18  which is spaced between a cargo container&#39;s corner fitting  21  and a vehicle deck&#39;s appropriate structure and surface  25 . 
   The illustrations within this document show that the vehicle deck&#39;s appropriate structure and surface  25  is a flat structure. Surface  25  is described herein as a vehicle deck, but may be other types of surfaces. It is also to be noted that the scope of the design of latch device  10  is not to be limited to an appropriate structure and surface  25  being a flat structure. Housing  11 , base bottom  16  and base  18  are allowed to be varied as defined by the user. 
   Housing  11  is adapted to accommodate latch  12 . Housing  11  includes internal pockets  22  and  23  that accommodate pin  13  to secure latch  12  inside housing  11 . Housing  11  also includes internal pocket  28  adapted to allow latch  12  to pivot therein. Housing  11  also includes cavity  42  adapted to accommodate spring  14 . Internal housing surface  38  and surface  39  are adapted to contact surface  35  and  36  of leg  29  of latch  12  when latch  12  is in various positions. Surfaces  26  and  27  of housing  11  are adapted to accommodate pin  13  thereby allowing latch  12  to pivot in the desired positions. The typical application of latch device  10  is for securing a standard cargo container  20  onto a vehicle deck or frame surface  25  such as shown in FIG.  11 . 
   The latch  12  as best seen in  FIG. 7  includes a leg  29  at one end and a convex upper-side  41  at the opposite end. A latch aperture  34  is between the leg  29  and upper-side  41  to allow movement of the latch  12 . Leg  29  includes an upper housing contact surface  35  and a lower housing contact surface  36  on opposite sides. Surfaces  35  and  36  engage internal housing surface  38  and  39  at different times depending on the position and movement of the latch  12 . The convex upper-side  41  of latch  12  includes a concave underside  40  adapted to engage a surface of the corner casting  21  of a cargo container  20 . Latch  12  includes a protrusion  30  preferably partially formed in a recess of latch  12 . Protrusion  30  is adapted to accommodate one end of spring  14 . 
     FIG. 6  illustrates side holes  32  and  33  in housing  11  that are used to insert pin  13  during assembly of device  10 . Side screws  15  and  37  are installed into side holes  32  and  33  of housing  11  to assure that pin  13  remains within housing  11  during operation of device  10 . Spring  14  operates between protrusion  30  of the latch  12  and cavity  42  of the housing  11 . Spring  14  sits within cavity  42  in housing  11  and assures proper orientation of spring  14  during operation of device  10 . 
     FIG. 12  represents the earliest operational stage of when a corner casting  21  of a standard cargo container  20  is being removed off of the latch device  10  and is starting to make contact with the concave underside  40  of latch  12 . It is to be observed that latch  12  is secured in the internal pockets  22  and  23  of housing  11  by pin  13 . In this illustration, latch aperture  34  is defined by a through hole. Pin  13  interfaces with pin receiving latch aperture  34 .  FIG. 5  shows the two ends  17  and  19  of pin  13  contact the internal housing pockets  22  and  23  respectively. Spring  14  being positioned onto the protrusion  30  of latch  12  assures that latch  12  is secured into proper position. 
   As corner casting  21  of a standard cargo container  20  is being removed off of the latch device  10  and is in contact with the concave underside  40  of latch  12 . It is to be observed that latch  12  is pivoting about pin  13  in the internal pockets  22  and  23  of housing  11 . Latch aperture  34  is contacting and pivoting about pin  13  in the internal housing pockets  22  and  23 . Spring  14  being positioned onto the protrusion  30  of latch  12  assures that latch  12  translates and pivots through the desired motion. The actual location and shape of latch aperture  34  and internal housing pockets  22  and  23  are allowed to be tailored as desired to obtain the desired release action of the latch device  10 . 
     FIG. 13  represents the operational stage of when a corner casting  21  of a standard cargo container  20  is being removed off of the latch device  10  and is making contact with the concave underside  40  of latch  12 . It is to be observed that leg  29  of latch  12  has pivoted and rotated in the internal pocket  28  of housing  11  about pin  13 .  FIG. 13  shows that surface  35  of leg  29  of latch  12  is now coming into contact and pivoting about internal housing pocket  28  at surface  38 . Pin  13  being positioned in the internal housing pockets  22  and  23  assures that latch  12  translates and pivots through the desired motion. The actual location and shape of latch surface  35  and internal housing surface  38  is allowed to be tailored as desired to obtain the desired release action of the latch device  10 . 
   This two or more surface pivot and contact area  35  of latch  12  during the release action of latch device  10  is similar but unique from prior art Brewster U.S. Pat. No. 5,570,981. Latch  12  of latch device  10  is guided and restrained by a pin  13  but has an additional latch pivot area  35  about internal housing surface  38 . Line of action  43  defines the travel line that the contact surfaces of corner casting  21  of a standard cargo container  20  travels while it is being removed off of or being placed onto the latch device  10 . Typically, it is desired that latch aperture  34  contacting and pivoting about pin  13  in internal housing pockets  22  and  23  be near or to the right of line of action  43 , which results in minimizing the mechanical force advantage of spring  14  illustrated in FIG.  13 . Minimizing the mechanical force advantage of spring  14  during initial release motion of corner casting  21  aids in obtaining low applied forces and smooth startup motion of latch  12 . After startup motion of latch  12 , it is desired to increase the mechanical force advantage of spring  14  so as to minimize the required size of spring  14 . This is accomplished by creating new pivot areas other than aperture  34  of latch  12  farther away and to the left of, or outboard of, line of action  43  as illustrated in FIG.  13  and previously described. 
     FIGS. 13 ,  14  and  15  represent operational stages further along when a corner casting  21  of a standard cargo container  20  is being removed off of the latch device  10  and eventually clearing contact with the concave underside  40  of latch  12 . It is to be observed that latch  12  is pivoting in the internal pocket  28  of housing  11  by its leg  29 .  FIGS. 13 ,  14  and  15  show latch surface  35  is contacting and pivoting about internal housing pocket  28  at surface  38 . It is allowed for latch surface  35  to be contoured and to contact and pivot about internal housing pocket  28  at surface  38  to obtain the desired release effect of latch device  10 . Pin  13  being allowed rotate out of pockets  22  and  23  of housing  11  and translate along surfaces  26  and  27  of housing  11 . Surfaces  26  and  27  of housing  11  are contoured to assure pin  13  and latch  12  translates and pivots through the desired motion. The actual location and shape of latch aperture  34  and surface  35  and internal housing pockets and surfaces  22 ,  23 ,  26 ,  27  and  38  are allowed to be tailored as desired to obtain the desired release action of the latch device  10 . 
     FIG. 8  represents the earliest operational stage of when a corner casting  21  of a standard cargo container  20  is engaging with latch device  10  and is starting to make contact with the convex upper-side  41  of latch  12 . It is to be observed that latch  12  is secured in the internal pockets  22  and  23  of housing  11  by its pin  13 . Latch surface  36  contacts internal housing at surface  39 . Spring  14  being positioned onto the protrusion  30  of latch  12  assures that latch  12  is secured into proper position. As corner casting  21  of a standard cargo container  20  is engaging the latch device  10 , container  20  and is in contact with the convex upper-side  41  of latch  12 . Latch  12  pivots in the internal pocket  28  of housing  11  by its leg  29  when container  20  moves downward. Latch surface  36  is contacting and pivoting about internal housing pocket  28  at surface  39 . Pin  13  being allowed rotate out of pockets  22  and  23  of housing  11  and translate along translation surfaces  24  and  31  of housing  11 . Surfaces  24  and  31  of housing  11  are contoured to assure pin  13  and latch  12  translates and pivots through the desired motion. The actual location and shape of latch aperture  34  and surface  36  and internal pockets and housing surfaces  22 ,  23 ,  24 ,  31  and  39  are allowed to be tailored as desired to obtain the desired engagement action of the latch device  10 . 
   It is to be observed that this pivot and contact area  36  of latch  12  during the engagement action of latch device  10  is similar to prior art Brewster U.S. Pat. No. 5,570,981. Line of action  43  defines the travel line that the contact surfaces of corner casting  21  of a standard cargo container  20  travels while it is engaging and being placed onto the latch device  10 . Typically, it is desired that latch surface  36  contacting and pivoting about internal housing pocket  28  at surface  39  be as far away and to the left of line of action  43 , which results in minimizing the mechanical force advantage of spring  14  as illustrated in FIG.  9 . Minimizing the mechanical force advantage of spring  14  during the engagement motion of corner casting  21  aids in obtaining low applied forces and smooth engagement motion of latch  12 . 
     FIGS. 9 and 10  represents operational stages further along when a corner casting  21  of a standard cargo container  20  is being engaged onto latch device  10  and clears contact with the convex upper-side  41  of latch  12 . It is to be observed that latch  12  is pivoting in the internal pocket  28  of housing  11  by its leg  29 .  FIG. 9  shows latch surface  36  is contacting and pivoting about internal housing pocket  28  at surface  39 . Pin  13  being allowed rotate out of pockets  22  and  23  of housing  11  and translate along surfaces  24  and  31  of housing  11 . Surfaces  24  and  31  of housing  11  are contoured to assure pin  13  and latch  12  translates and pivots through the desired motion. The actual location and shape of latch aperture  34  and surface  36  and internal housing pockets and surfaces  22 ,  23 ,  24 ,  31  and  39  are allowed to be tailored as desired to obtain the desired engagement action of the latch device  10 . 
   Although the preferred embodiment of the invention is illustrated and described in connection with a particular type of latch, it can be adapted for use with a variety of latches. Other embodiments and equivalent latch devices and methods are envisioned within the scope of the invention. Various features of the invention have been particularly shown and described in connection with the illustrated embodiment of the invention; however, it must be understood that these particular embodiments merely illustrate and that the invention is to be given its fullest interpretation within the terms of the appended claims.