Abstract:
A device for securing a container to a hoist includes a frame rigidly connectable to the hoist; first and second hooks mounted in mutually close proximity and to the frame to rotate about an axis between a retracted, unlocked position away from the long sill of the container and an activated, locking position disposed at least partially over the long sill; an actuator mounted to the frame to move between an activating position and a retracting position, the actuator engageable with the hooks to rotate the hooks from the activated, locking position to the retracted, unlocked position when the actuator moves from the activating position and the retracting position; springs operationally connected with the hooks for urging the hooks toward the activated, locking position; and, a power device connected with the actuator to move the actuator between the activating and retracting positions.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of material-hauling containers and vehicles for transporting such containers, and specifically to devices for securing such containers to the vehicles. 
     BACKGROUND OF THE INVENTION 
     Large containers are available for collecting, transporting and/or dumping waste, bulk and liquid materials. A typical container will include at least a pair of long sills running the length thereof and a plurality of laterally extending cross sills spaced along the length of and atop the long sills. Such containers are transported on large container hoists that include a vehicle with a hoist frame hingedly connected to the rear of the vehicle frame. The hoist frame includes a long pair of hoist frame rails and can be pivoted between a container loading, unloading and dumping position and a horizontal transport position. When a container is pulled atop the hoist frame, the long sills of the container straddle the hoist frame rails, and the front of the container is secured to the front end of the hoist by the lifting device or other suitable restraint mechanism, in accord with the applicable governing regulations. Such regulations also provide that the rear of the container must likewise be secured. One acceptable manner of tiedown is by hooks or an equivalent mechanism, securing both sides of the container to the vehicle chassis or hoist frame. Such mechanism must be within two meters of the rear of the container. 
     A variety of hold-down mechanisms have been devised to secure the rear end of a container to the hoist frame. One type of hold-down device includes a fixed hook mounted on each side of the container hoist and mating posts extending outwardly from opposing sides of the container. As the container is pulled up onto the hoist, the posts register under the fixed hooks to secure the container onto the hoist. There are a number of problems associated with this type of arrangement. For example, some containers may lack the mating post, in which case there will be nothing to hold the rear end of the container down which, in addition to being a violation of the federal regulations, would pose a significant safety concern. Another problem is that the fixed hook and post design does not permit longitudinal adjustment of the container on the hoist, which is often desired to optimized the weight distribution of the load over the vehicle axles. 
     Another type of hold-down device includes a hook pivotably mounted to the hoist frame and operable to pivot up and over the container long sill. Such devices frequently fail to lockingly engage with the container long sill, however, because one of the container cross sills obstructs the pivoting hook&#39;s path. This occurs because the vehicle hoists and containers vary in size and configuration from one manufacturer to another and because the containers are not always located in the exact same position upon a particular hoist. For example, the spacing between adjacent cross sills of typical containers can vary between 12 and 20 inches. In special cases where extraordinary strength is needed, a container could be made with cross sills spaced considerably closer together. As a result, the chances are fairly good that a cross sill of a container will align with the hold-down hook of a hoist, which in turn will prevent the hook from properly engaging with the container long sill. 
     What is desired is an improved device for holding a container down in a secure position atop a vehicle-mounted hoist frame. 
     SUMMARY OF THE INVENTION 
     Generally speaking, there is provided a device for securing a container to a vehicle-mounted hoist frame, the device including a mutually proximal pair of hooks that can be actuated to pivot up and over the top of the long sill of a container. 
     A device for securing a container to a hoist includes a frame rigidly connectable to the hoist; first and second hooks mounted in mutually close proximity and to the frame to rotate about an axis between a retracted, unlocked position away from the long sill of the container and an activated, locking position disposed at least partially over the long sill; an actuator mounted to the frame to move between an activating position and a retracting position, the actuator engageable with the hooks to rotate the hooks from the activated, locking position to the retracted, unlocked position when the actuator moves from the activating position and the retracting position; springs operationally connected with the hooks for urging the hooks toward the activated, locking position; and, a power device connected with the actuator to move the actuator between the activating and retracting positions. 
     It is an object of the present invention to provide an improved device for holding a container securely onto a vehicle-mounted hoist frame. 
     Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE INVENTION 
     FIG. 1 is a perspective view of a hold-down device  10  in accordance with the preferred embodiment of the present invention. 
     FIG. 2 is a plan view of the hold-down device  10  of FIG.  1  and showing hooks  16  and  17  in the retracted, unlocked position. 
     FIG. 3 is a side elevational view of the hold-down device  10  of FIG. 2, taken along the lines  3 — 3  and viewed in the direction of the arrows. 
     FIG. 4 is a perspective view of central hook actuator  18  of the hold-down device  10  of FIG.  1 . 
     FIG. 5 is a side elevational view of the hold-down device  10  of FIG.  3  and showing hooks  16  and  17  in the activated, locking position. 
     FIG. 6 is a side elevational view of the hold-down device  10  of FIG.  5  and showing hook  17  in the activated, unlocked position. 
     FIG. 7 is a top plan view of central hook actuator  18  and spring loading tool  95  in a spring loading position. 
     FIG. 8 is a side elevational view of the central hook actuator  18  and spring loading tool  95  of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and that any alterations or modifications in the illustrated device, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
     Referring to FIGS. 1-3, there is shown a hold-down device  10  for securing a container onto the hoist frame  11  of a vehicle (not shown). The vehicle is any appropriate vehicle designed to pick up and carry a container such as a container for hauling waste. Such vehicle typically is provided with a hoist frame hingedly connected to the rear of the vehicle so that the hoist frame  11  may be pivoted between a horizontal transport position and an inclined loading, unloading and dumping position. Such vehicles are well known in the material hauling industry. 
     Device  10  generally includes a support frame  15 , a pair of hooks  16  and  17 , a central hook actuator  18 , a pair of coil springs  21  and  22 , an air cylinder  23  and a pivot axle  24 . Frame  15  includes a main mounting bracket  26  and a housing body  27 . Main mounting bracket  26  includes an angle iron brace  28 , a pair of inner mounting brackets  31  and  32  and a pair of outer mounting brackets  33  and  34 . Mounting brackets  31 - 34  each define mutually co-axial holes sized to receive axle  24  therethrough. Housing body  27  includes a pair of opposing side walls  35  and  36  and front cross member  37  rigidly extending between walls  35  and  36 . Side walls  35  and  36  are rigidly connected at their inboard ends to outer mounting brackets  33  and  34  by any appropriate means such as welding, as shown. Front cross member  37  further includes a pair of upstanding cylinder mounting brackets  40  and  41 . Frame  15  has an uppermost surface  42  that is located on the top of brace  28 . In the  5  retracted, unlocked position (FIG.  3 ), all remaining elements of device  10  lie below surface  42 . Consequently, when device  10  is mounted to hoist frame  11  and the hooks  16  and  17  are retracted, device  10  is located sufficiently below and will not obstruct any downwardly protruding elements (such as wheels) of a container being loaded on hoist frame  11 . In one embodiment, the uppermost edge  43  of hook  17  in the retracted position (FIG. 3) is at least two inches below surface  42 . While container configurations will vary from one container to another, the design of hold-down device  10  enables both a flat and low profile while also allowing the hooks  16  and  17  to rotate up to a secure locking position on a widely sized range of containers. 
     Hooks  16  and  17  are mirror images of each other, and description will primarily be directed to just one of hooks  16  and  17 , it being understood to apply to the other of the hooks in mirror fashion. Hook  17  includes a central mounting portion  44 , a leg  45  extending generally radially outwardly from mounting portion  44 , and a hook member  46  extending generally orthogonally from arm  45 , as shown in FIG.  3 . Central mounting portion  44  includes a central hole  49  sized to receive axle  24  therethrough. Hook  17  further defines a control arm  51  that extends laterally from a region on mounting portion  44  approximately at the juncture of mounting portion  44  and leg  45  and toward the other hook  16 . Control arms  51  and  50  (of hook  16 ) extend toward each other an equal distance, but do not touch. Hooks  16  and  17  are each provided with a grease fill port  52  that is in communication with its central hole  49 . 
     Referring to FIGS. 1-4, central actuator  18  includes a central, cylindrically shaped hub  55 , a control fin  56 , a piston connection fin  57 , and a spring bar  58 . Hub  55  defines a central bore  60  with an axis  61 , the bore  60  extending through the width of hub  55  and being sized to receive axle  24  therethrough. For purposes of description, hub  55  also includes opposing left and right annular faces  64  and  65  that are in mutually parallel planes and orthogonal to axis  61 . Also extending substantially perpendicular to axis  61  are forwardly extending control fin  56  and rearwardly extending piston connection fin  57 . Control fin  56  includes a hook bar  66  with a downwardly facing engagement surface  67  that is configured and positioned to engage with the control arms  50  and  51  of hooks  16  and  17  during operation of hold-down device  10 , as discussed herein. In the present embodiment, surface  67  lies in the same plane with axis  61 . A grease fill port  68  (FIGS. 1 and 8) is provided to hub  55 , the port  68  being in communication with central bore  60 . 
     Piston connection fin  57  extends rearwardly of axis  61  (to the left in FIG. 2) and downwardly of planar surface  67  (as viewed in FIG.  2 ). At its outboard end  69 , fin  57  rotatably connects with the outboard end  70  of piston rod  71  of air cylinder  23  by a pin  72  that extends through a hole  73  in fin  57 . Hole  73  is disposed far enough below planar surface  67  to permit piston rod  71  to connect with hole  73  without contacting hub  55  in the retracted, unlocked position shown in FIG.  3 . Piston connection fin  57  also defines a spring tool recess  74  in its outboard end  69 , proximal to hole  73 . 
     Like hooks  16  and  17 , coil springs  21  and  22  are mirror images of each other, and description of one is intended to apply in mirror fashion to the other. Springs  21  and  22  are coil springs with their terminal arms  76 - 77  and  78 - 79  extending substantially tangentially therefrom. Springs  21  and  22  are operationally engaged with hooks  16  and  17  to urge hooks  16  and  17  toward the activated, locking position shown in FIG.  5 . The spring constant K of spring  22  is selected to cause corresponding hook  17  to firmly engage and stay in the locking position over a long sill  82  of a container, but also to permit the corresponding hook to be manually pulled away from the locking position. In one embodiment, spring  22  is a coil spring with a Spring Index C of 10.5942, a Rate of 2.2470# —in/deg.and a Nat. Freq. of 120.2847 Hz. 
     Hooks  16  and  17 , springs  21  and  22  and central hook actuator  18  are mounted for rotation to frame  15  by axle  24 . In one embodiment, axle  24  is a bolt and a nut. These elements are assembled as shown in FIGS. 1-3 whereby springs  21  and  22  encircle hub  55  on opposite sides of control fin  56  and are preloaded, as described herein. Central actuator  18  and springs  21  and  22  are then positioned between inner mounting brackets  31  and  32 , and hooks  16  and  17  are positioned between their respective mounting bracket pairs  31 ,  33  and  32 ,  34 , respectively, as shown in FIG.  3 . Axle  24  is then received through the now coaxial holes in all these members to permit hooks  16  and  17 , central hook actuator  18  and springs  21  and  22  to rotate about axle  24 . Washers, such as at  83  are provided between certain of these members, as desired. As shown in FIG. 3, spring  21  is disposed upon hub  55  such that terminal arm  76  is lodged counter clockwise of spring bar  58 , and the opposing terminal arm  77  is disposed clockwise of control arm  50 . Furthermore, terminal arms  76  and  77  are stressed in the positions shown in FIG. 2 such that terminal arms  76  and  77  are biased to unwind toward each other in the direction of arrows  85  and  86 . 
     Frame  15  is rigidly connected to the frame longitudinal running frame rails  87  of hoist  11  by appropriate means such as welding, and it is positioned so that when hooks  16  and  17  are actuated, as shown in FIGS. 1 and 4, at least one of hooks  16  and  17  will be properly positioned over the long sill  82  of the corresponding container that has been positioned onto hoist frame  11 . Hold-down device  10  may be mounted to the outside or inside of the frame rails  87 , as space permits. 
     Hold-down device  10  operates as follows: 
     With hold-down device  10  in the retracted, unlocked position shown in FIG. 2, air cylinder  23  is activated to retract piston rod  71  which rotates actuator  18  and its spring bar  58  and engagement surface  67  counterclockwise in excess of 90°, approximately to the position shown in FIG.  5 . In one embodiment, actuator  18  is configured to rotate through an angle of 99°. Rotation of spring bar  58  further winds terminal arms  76  and  78  of springs  21  and  22  about hub  55 . Since bar  66  has also rotated counterclockwise, hooks  16  and  17 , under the bias of terminal arms  77  and  79  of springs  21  and  22 , also rotate the same approximate 99°, depending on the size, configuration and positioning of the corresponding hoist frame and container. Hooks  16  and  17  are prevented from rotating any further counterclockwise by the abutting engagement of their control arms  50  and  51  against engagement surface  67  of hook bar  66  or by engagement with long sill  82 . As shown in FIG. 5, hooks  16  and  17  are both in the activated, locking position, and the hook members  46  are thereby in a hold-down, locking position over the long sill  82  of a container positioned atop hoist frame  11 . Containers received onto hoist frames described herein typically include long sills  82  in addition to a plurality of cross sills  88 . When the container is received onto the hoist, and hold-down device  10  is activated, a cross sill  88  may impede one of hooks  16  and  17  from fully rotating to the activated, locking position shown in FIG.  5 . In this case, as shown in FIGS. 1 and 6, the impeded hook  17 , though biased to continue rotating counterclockwise, engages the underside of cross sill  88 , and cannot rotate any farther counterclockwise. In a typical container, the cross sills  88  will be between about 12 and 20 inches apart on center and may be up to about 3.5 inches or 3.75 inches wide. In this typical case, the minimum gap between a pair of adjacent cross sills would be a little over about eight inches. The hooks  16  and  17  of device  10  are sized, configured and assembled to be in mutual close proximity. That is, they are relatively close together so that they will not both be impeded by a pair of adjacent cross sills of a typical container. In one embodiment, the total width W of hooks  16  and  17 , from outer face  90  to outer face  91 , is about seven inches, which would prevent both hooks  16  and  17  from being impeded at the same time by two, adjacent cross sills of a typical container. Likewise, the gap G between hooks  16  and  17  in one embodiment is about four inches, which would prevent both hooks  16  and  17  from being impeded at the same time by a single cross sill  88  in a typical container. The present invention is thus designed to accommodate the vast majority of container configurations. It is recognized, however, that, despite the added cost and weight, a container may be constructed for a special purpose where the cross sills are wider than normal and/or considerably closer together than normal. In such case, the hooks  16  and  17  of device  10  are sized, configured and assembled to be in mutual close proximity relative to the specially sized container so that both hooks cannot be impeded in their rotation to securely hold-down the container. Such mutually close proximity is understood to include values for the width W and gap G that may differ from the foregoing preferred values of seven inches and four inches, respectively, as dictated by the specially sized container. In FIG. 6, since the next, most-adjacent cross sill (not shown) to cross sill  88  is farther from cross sill  88  than the distance between hooks  16  and  17 , hook  16  will not be impeded from fully rotating to its activated, locking position. Long sill  82  is thereby successfully engaged by at least one of hooks  16  and  17 , and the corresponding container (not shown) is properly locked in the hold-down position. 
     Referring to FIGS. 7 and 8 there is shown a spring loading tool  95  to facilitate preloading of springs  21  and  22 . Tool  95  comprises a U-shaped piece of wire having a relatively straight, central fin engagement portion  96 . The opposing, outboard ends of tool  95  are curved around to form loops  98  and  99  that are sized and shaped to receive the terminal ends  77  and  79  of springs  21  and  22 . 
     In use, springs  21  and  22  are slid onto the opposing ends of hub  55 . Actuator  18  is then stabilized such as by clamping it in a vice or similar structure such that the opposing faces  64  and  65  are engaged with the jaws of the vice. Tool  95  is then positioned so that spring terminal ends  77  and  79  (now in the relaxed position shown in dashed lines in FIG. 8 at  92 ) extend through loops  98  and  99 , respectively. Spring ends  77  and  79  may then be manually pulled along with tool  95  to the preloaded condition whereby fin engagement portion  96  is positioned up over outboard end  69  sufficient to allow it to seat within recess  74 . Terminal ends  77  and  79  are now held in the preloaded condition, and actuator  18 , springs  21  and  22 , and the remaining elements may then be assembled as described above. Once actuator  18  and springs  21  and  22  are mounted to frame  15 , tool  95  is removed by pulling fin engagement portion  96  down and out of recess  74  whereby terminal ends  77  and  79  rotate up against control arms  50  and  51 , respectively, and bias them in the direction of arrow  86 . 
     Components described herein may be manufactured separately or may be integrally formed to accommodate ease of replacement, cost considerations, maintenance concerns and the like. In addition, cylinder  23  is described as an air cylinder, but any other appropriate powering means are also contemplated, such as a hydraulic cylinder or a mechanical device such as a rack and pinion combination. 
     It is contemplated that actuator  18  may be of different construction or may made to interact differently with the other components of device  10  so long as a powered unit, such as cylinder  23 , operates to rotate the hooks  16  and  17  from the activated, locking position to the retracted, unlocked position when desired. For example, and not by limitation, piston rod  71  could be connected with hooks  16  and  17  using a slot and pin arrangement. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrated and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.