Abstract:
A locking mechanism has a guide and a vertically movable plate. The plate is movable in the guide under gravitational influence between a locked position and an unlocked position. A slot is formed in the plate to receive a guide pin. The guide pin maintains the movable plate in the guide. The slot enables axial vertical movement of the plate in the guide. The plate moves into the locked position upon contact with a surface. In this position, the plate projects from the guide to lock a roll off container onto the hoist. The movable plate reverts to the unlocked position upon removal of the surface so that the plate moves into the guide.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/346,051, filed on Jun. 6, 2016. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to vehicles that transport refuse roll off containers and, more particularly, to a locking mechanism to secure the roll off container to a hoist on the vehicle. 
       BACKGROUND 
       [0003]    During transporting of refuse roll away container, generators or the like, it is desirable to lock the container onto the hoist during transport so that the container is unable to move on the hoist. Types of devices exist to secure and lock these roll off containers with the hoists. While these types of locking devices are satisfactory to lock the roll off containers with the hoists, designers strive to improve the art. 
         [0004]    The present disclosure provides the art with a device that locks roll off containers to a hoist. The device is influenced by gravity to move the device between a locked and an unlocked position. The present disclosure provides a movable plate that moves vertically with respect to the hoist. The movable plate moves between a locking position, where a surface forces the movable plate to extend out of a guide above the hoist rail, to an unlocking position, where the movable plate passes through the hoist rail. 
       SUMMARY 
       [0005]    Accordingly to a first aspect of the disclosure, a locking mechanism to secure a roll off container to a hoist comprises a guide with a vertically moving plate. The plate is movable in the guide under gravitational influence between a locked position and an unlocked position. A slot is formed in the movable plate to receive a guide pin. The guide pin maintains the movable plate in the guide. The slot enables vertical movement of the plate in the guide such that the movable plate moves into the locked position upon contact of the plate with a surface on the frame. The plate projects from the guide to lock the roll off container onto the hoist. The plate reverts to the unlocked position upon removal of the surface so that the movable plate moves into the guide by gravity. The plate has an overall elongated rectangular configuration with a pair of parallel sides. One end of the plate, between the parallel sides, has a tapered portion with a radiused corner. The slot is defined by a pair of parallel edges that is parallel with the parallel sides. 
         [0006]    According to a second object of the disclosure, a vehicle having a roll off container locking mechanism comprises a vehicle with a frame and a powertrain to drive the vehicle. A hoist is positioned on the frame. The hoist moves between a roll off container pickup position and a roll off container transport position. The locking mechanism is coupled with the hoist. The locking mechanism comprises a guide with a vertically moving plate. The plate is movable in the guide under gravitational influence between a locked position and an unlocked position. A slot is formed in the movable plate to receive a guide pin. The guide pin maintains the movable plate in the guide on the hoist. The slot enables vertical movement of the plate in the guide such that the movable plate moves into a locked position upon contact with a surface on the frame. The plate projects from the guide to lock the roll off container onto the hoist. The plate reverts to the unlocked position upon removal of the surface so that the movable plate moves into the guide on the hoist. The plate has an overall elongated rectangular configuration with a pair of parallel sides. One end of the plate, between the parallel sides, has a tapered portion with a radiused corner. The slot is defined by a pair of parallel edges that is parallel with the parallel sides. A front hold down is positioned on the hoist adjacent the locking mechanism. A portion of the roll off container is locked between the front hold down and the locking mechanism. 
         [0007]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0008]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0009]      FIG. 1  is a side elevation view of a refuse vehicle with a hoist for loading, unloading, and transporting roll off containers. 
           [0010]      FIG. 2  is a side elevation view of a refuse vehicle with a roll off container attached to a cable on the hoist. 
           [0011]      FIG. 3  is a side elevation view of a refuse vehicle with a container on the hoist. 
           [0012]      FIG. 4  is a perspective view of the hoist and frame. 
           [0013]      FIG. 5  is a detailed perspective view of the locking mechanism. 
           [0014]      FIG. 6  is a side elevation view partially in section of the locking mechanism. 
           [0015]      FIG. 7  is an elevation view of an additional embodiment of a locking plate. 
           [0016]      FIG. 8  is a perspective view of an additional lift mechanism. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Turning to the figures, a vehicle for loading, unloading, and transporting roll off containers is illustrated and designated with a reference numeral  10 . The vehicle  10  typically includes a cab  12  and a chassis or vehicle frame  14 . The vehicle  10  includes a drivetrain with an engine, shafts and wheels  16  that move the vehicle  10  in a conventional manner. A hoist  20 , also known as a “tilt frame,” is adapted to be mounted on the chassis or frame  14 . 
         [0018]    The hoist  20  includes a pair of side rails  22 ,  24  and a lifting mechanism  26 . In this regard, the use of the term “container” is not meant to be limiting. Although it is anticipated that the invention will be used primarily on refuse containers, it can be used to load or unload virtually any structure or object known today, including storage containers, portable generators and the like. 
         [0019]    The hoist  20  is pivotally attached to the bed or frame  14  of the vehicle  10  in a conventional manner. The lifting mechanism is generally referred to by the reference numeral  26 . A pair of hydraulic cylinders  38 ,  40  is used to rotate or tilt the hoist  20  relative to the frame  14  in a manner shown in the drawings. In this regard, the tilting of the hoist  20  is conventional with container vehicles of this type and it is not believed necessary to describe the tilting and pivoting mechanism in further detail. A hydraulic fluid for the hydraulic cylinders used with the invention is typically contained in a fluid tank box  42 . A control valve  44 , for the hydraulic cylinders, is typically positioned adjacent the tank box  42 . 
         [0020]    As indicated, the free end of the cable  32  extends from the movable carriage  28 . The cylinder  27  moves the carriage  28 . The free end of the cable  32  is of sufficient length that it can be attached to a container  18  positioned behind or at the rear of the vehicle  10 . The free end of the cable  32  may contain any conventional mechanism for latching to a container  18  such as a latch, clasp, or hook  46 . 
         [0021]    Once the cable  32  is attached to the container  18 , as shown in  FIG. 1 , the vehicle operator operates the movable carriage  28 . This moves the container onto the hoist  20  as illustrated in  FIG. 2 . The hook  46  or attaching mechanism has been attached to the container  18 . The operator pulls the container  18 , via the carriage  28 , toward the hoist  20  and continues to load the container  18  all the way onto the hoist  20 . 
         [0022]    As the container  18  is loaded onto the hoist frame  20 , it is pulled towards the end of the hoist  20 . As this occurs, a bar  19  of the container  18  contacts a front hold down  52  to position the container  18  on the hoist  20 . As the hoist  20  is moved towards the frame  14 , a locking mechanism  60  locks the container  18  onto the hoist  20  as seen in  FIG. 3 . 
         [0023]    The locking mechanism  60  is positioned adjacent the front hold down  52 . The locking mechanism  60  secures the bar  19  or the like of the roll off container  18  to the hoist  20  during transport of the container  18 . 
         [0024]    The locking member  60  includes a plate  62  that is held within a guide  64  within the rail  22 . The guide  64  includes an aperture or bore  66  with a pair of guide plates  68  and  70  defining the sides of the bore  66 . The guide plates  68 ,  70  help to prevent swaying of the locking plate  62  in the guide  64 . The guide plates  68 ,  70  can be secured with the rail  22  to hold the guide  64  in position. 
         [0025]    The plate  62  has an overall rectangular configuration as seen in  FIG. 5 . The plate  62  includes a pair of parallel sides  72 ,  74 . The one end  76 , between the parallel sides  72 ,  74 , includes a tapered portion  78  and a radius corner  80 . This enhances securement of the container  18  in the locking mechanism  60 . The other end  82  includes a flat portion  84  that is substantially perpendicular to the parallel sides  72 ,  74 . Also, tapered portions  86  extend from portion  84  to the parallel sides  72 ,  74 . Any type of configuration could be utilized at this end to contact the frame surface. 
         [0026]    A slot  88  is formed in the plate  62 . The slot  88  is defined by a pair of parallel edges  90 ,  92 . The edges  90 ,  92  are parallel to one another as well as parallel to the sides  72 ,  74 . The ends of the slot  88  are defined by arcuate edges  94 ,  96 . Thus, the slot  88  has an overall oval or elliptical configuration. A guide pin  98  is secured onto the rail  22 . The guide pin  98  can be welded or the like so that the slot  88  receives the guide pin  98  in the bore  66  on the rail  22 . Thus, the plate  62  moves vertically within the guide  64 . The guide pin  98  also acts as a stop, contacting the arcuate edge  94  of the slot  88 , to prohibit further movement of the plate  62  through the rail  22 . Alternatively, slots could be formed in the rail  22  and a guide pin  98  could be formed on the plate  62 . Thus, the guide pin  98  would move in the slots on the rail. 
         [0027]    The mechanism for locking containers  60  is influenced by gravity. The gravitational influence enables the plate  62  to pass through the rail  22  when the rail  22  is moved away from the frame  14 , as shown in phantom in  FIG. 1 . Also, when the rail  22  is in a down position adjacent the frame  14 , the surface of the frame  14  pushes the plate  62  so that it projects from the rail  22  into a locking position, as seen in  FIGS. 4 and 5 . Accordingly, the locking mechanism  60  utilizes gravity to move the locking mechanism  60  between a locked and unlocked position. 
         [0028]      FIG. 7  illustrates an additional plate  62 ′. The same reference numerals have been used to identify the same features. Here, the plate  62 ′ includes a first end  104  that is perpendicular to sides  72 ,  74  and parallel to end portion  84 . Here, the plate  62 ′ uses sides  72 ,  74  to contact the container  18 . 
         [0029]    An additional refuse hoist is illustrated in  FIG. 8 . Here, it includes a hinged tail  110 . A pulley or sheave  112 , to accommodate cable movement, is positioned on the tilt frame  20  at the rotation point of the hinged tail member  110 . This enables the cable  32  to easily follow along in the plane of the hinged tail member  110  when it is rotated to its down or lowered position. 
         [0030]    The free end of the cable  32  is passed around the sheave  112 . The free end of the cable  32  is of sufficient length that it can be attached to a container  18  positioned behind or at the rear of the vehicle  10 . 
         [0031]    Once the cable  32  is attached to the container  18 , the vehicle operator operates the carriage  28 . The hinged tail  110  may be rotated until the end and roller is positioned on or near the ground or other ground surface. Note that the operator can in some situations pull the container  18  onto the hinged tail  110  without raising the hoist  20  and with skill, continue to load the container  18  all the way onto the hoist  20 . Also, the operator can, in some situations, pull the container  18  onto the hinged tail  110  with a combination of pulling the container  18  forward and lifting the hinged tail  110 . In this regard, in some instances, containers  18 , waiting to be loaded onto the vehicle, are “frozen” to the ground and the lifting or hinged tail  110  combination with the cable  32  will effectively break the containers free from the frozen ground. 
         [0032]    Another option for use is to pull the container  18  onto the hinged tail member  110  with the hinged tail  110  at the maximum angle with respect to the ground surface. The hinged tail angle provides a steeper angle to load the container  18 , which minimizes the potential of the container jumping the side rails  22 ,  24 . With the hinged tail  110  at the maximum angle with respect to the ground, the resultant angular pull of the cable  32  beyond sheave  112  provides greater vertical force and less horizontal force. The reduced horizontal component reduces forces that would cause a misaligned container  18  to jump over the side rails  22 ,  24  on the hoist  20 . 
         [0033]    By not having to raise the tilt frame member  20  to the extent necessary with conventional lift frame vehicles, the present disclosure enables the loading and unloading of the container  18  in a significantly faster manner. This increases the number of trips a vehicle operator can perform in a shift and thus lowers costs and increases revenue. 
         [0034]    Other types of lifting arrangements are illustrated in assignee&#39;s U.S. Pat. No. 8,444,365 entitled “Roll Off Hoist With Hinged Tail And Hydraulic Reeving System”; U.S. Pat. No. 8,465,246 and U.S. Pat. No. 9,446,700, both entitled “Roll Off Hoist With Hinged End Portion; U.S. Pat. No. 7,572,091 entitled “System For Loading/Unloading Containers”, U.S. Pat. No. 7,568,881 entitled “System And Method For Loading/Unloading Containers”, and U.S. Patent Application Publication No. 2013/0084152 entitled “Container Loading System”, all of which are herein incorporated by reference. 
         [0035]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.