Abstract:
A worker safety device for use with an object having a person support surface, the device comprising: a hinged device frame positionable on said object; a frame fastener coupled to the device frame configured to detachably fasten the device frame to the object; an attachment means, attached to the device frame, configured and positioned to attach a personal harness system to the device frame; whereby a person on said surface using the hinged device frame can prevent a fall from said surface by attaching the personal harness to the attachment means.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to the field of worker safety, and in particular, the field of devices and methods for improving worker safety. 
       BACKGROUND OF THE INVENTION 
       [0002]    In recent years, governments, businesses, and society at large have placed a progressively greater value on worker safety. Injuries to workers can be devastating to the injured workers themselves, their families, and their communities. The costs to businesses and governments associated with such injuries are also substantial. Such costs include the costs to businesses of insuring against the risk of liability for worker injuries. Meanwhile, it is usually government, and ultimately the taxpaying public, that bears the costs of caring for injured workers, particularly those that have suffered severe or catastrophic injury. For these and other reasons, businesses, governments and workers themselves striving to improve safety, including the optimization of work processes and methods, and the use of the most advanced safety-promoting equipment available. 
         [0003]    Tractor-trailers (also known as truck-and-trailer, or semi-trailer trucks) are a common sight on North American highways. A tractor-trailer consists of a towing engine (“tractor”), and a trailer that carries freight. The trailer (also referred to as a “truck trailer” is attached to the tractor at the tractor&#39;s rear end, so that some fraction of the weight of the trailer is held up by the tractor, while the rest of the weight rests on the trailer&#39;s own wheels. 
         [0004]    From time to time, it is necessary to perform repairs or routine maintenance on these trailers, requiring a repair person to climb onto the roof of the trailer. In winter, this routine maintenance can include removing snow from the roof. Climbing onto and working on the roof creates a safety hazard, namely, the risk that the worker will slip and/or fall off of the roof and suffer injury or death. 
       SUMMARY OF THE INVENTION 
       [0005]    Therefore, according to the present invention, there is provided a worker safety device for use with an object having a person support surface, the device comprising a hinged device frame positionable on said object; a frame fastener coupled to the device frame configured to detachably fasten the device frame to the object; an attachment means, attached to the device frame, configured and positioned to attach a personal fall arrest device to the device frame; whereby a person on said surface using the fall arrest device can prevent a fall from said surface by attaching the fall arrest device to the attachment means. 
         [0006]    According to another aspect of the invention, there is provided a method of preventing a worker from falling off of a roof of a truck trailer, the trailer having first and second side rails, the method comprising the steps of: providing a worker safety device including a length-adjustable device frame, a first frame fastening element at a first end of the device frame, and a second frame fastening element at a second end of the device frame; fastening the frame to the trailer by (1) positioning the device frame in a pre-fastening position and (2) actuating a frame fastener to cause the frame fastening elements to fasten the device frame to the side rails; and attaching fall-preventing worker safety gear to the device to prevent a worker from falling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Reference will now be made, by way of example only, to preferred embodiments of the invention and in which: 
           [0008]      FIG. 1  is a perspective view of a worker safety device according to the present invention as shown on the roof of a truck trailer; 
           [0009]      FIG. 2  is a top view of a worker safety device according to the present invention. 
           [0010]      FIG. 3  is a perspective view of a worker safety device according to the present invention, as shown in use by a worker on the roof of a truck trailer. 
           [0011]      FIG. 4  is a perspective view of a worker safety device according to the present invention, showing a worker after falling from the roof of a truck trailer. 
           [0012]      FIG. 5 a    is a top view of the worker safety device according to the present invention; 
           [0013]      FIG. 5 b    is a right side view of the worker safety device of  FIG. 5   a;    
           [0014]      FIG. 5 c    is a left side view of the worker safety device of  FIG. 5   a;    
           [0015]      FIG. 5 d    is a bottom view of the worker safety device of  FIG. 5   a;    
           [0016]      FIG. 5 e    is a front view of the worker safety device of  FIG. 5   a;    
           [0017]      FIG. 5 f    is a back view of the worker safety device of  FIG. 5   a;    
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring now to  FIGS. 1-4 , the worker safety device  2  is shown. As shown in  FIG. 3 , the device  2  is preferably positioned on an object, typically a truck trailer  4 . Trailer  4  comprises trailer body  6 , supported by trailer wheels  8 . Trailer  4  further comprises roof  10 , and sides, preferably in the form of first and second side walls  12 ,  14 . At the intersection between roof  10  and each side wall  12 ,  14  is a side edge of roof  10 . Typically, at each of the two side edges of roof  10 , there is a roof rail ( 16 ,  18 ) running along substantially the entire length of the trailer body  6 , from the back of the trailer to the front. Also on the side walls of the typical trailer body  6 , adjacent to each rail  16 , is a rail indentation ( 20 ,  22 ), generally located immediately below rail  16 . Some trailers have no such indentation, but commonly, the rail  16  protrudes outward beyond the portion of the wall ( 12 ,  14 ) immediately adjacent to rail  16 , providing a geometry that facilitates the fastening of the device  2  to the rails  16 ,  18 . 
         [0019]    It will be appreciated that the invention may be used on a variety of objects, including, without limitation straight trucks. 
         [0020]    An embodiment of the worker safety device  2  is shown at  FIGS. 1-4 . The device  2  comprises a hinged device frame  24  positionable on the object, typically the trailer  4 . It will be appreciated, as elaborated below, that the worker safety device  2  is preferably configured for use with an object, such as trailer  4 , that has a person-support surface on which a worker might be located. In the case of truck trailer  4 , that person-support surface would typically comprise roof  10 , but it will be appreciated that a device in accordance with the present invention may be used with other objects where it is desired to protect worker safety. 
         [0021]    As shown in  FIG. 3 , the device frame  24  is preferably positioned above the roof  10 , with the sides  20 ,  22  of the trailer  4  extending downward from the roof  10 . 
         [0022]    In the embodiment shown in  FIGS. 1-3 , the frame  24  comprises a first elongate member  26  and a second elongate member  28 . The members  26 ,  28  are preferably hingedly attached to one another by means of a joining plate  30 , and are pivotally moveable relative to one another. 
         [0023]    The device  2  further comprises an elasticized cord  32 , such as a bungee, frame fastener, which is attached at one end to a first mid-point  34  of the first elongate member  26  and at the other end to a second mid-point  36  of the second elongate member  28 . The elasticized cord  32  works bias the first elongate member  26  and second elongate member  28  together. In the process of fastening the frame  24  to the trailer  4 , fastening elements  38 ,  40  (described in further detail below) are pulled against the side edges of the trailer, so as to grip rails  16 ,  18 , and preferably engage indentations  20 ,  22 . The frame  24  is thus fastened to trailer  4 . To detach the frame  24 , members  26 ,  28  and elements  38 ,  40  are pulled apart against the force of elasticized cord  32 , thus releasing the grip of one or both of elements  38 ,  40  on the corresponding rail  16 ,  18 . 
         [0024]    It will be appreciated that apart from the preferred and alternate embodiments described herein, the invention comprehends other modes of frame fastener. What is important is that the fastener be configured to fasten the device frame to the object. Thus, for example, anything that functions to hold the frame  24  in place on the object could be a frame fastener. Preferably, though not necessarily, the device frame will be detachably fastened to the object, meaning that the frame fastener is selectively operable to fasten the frame to the object and detach the frame from the object. A further example of such a frame fastener would be selectively engageable and disengageable suction cups attached to the frame, configured to fasten the frame to the object when engaged, and detach the frame when disengaged. 
         [0025]    It will be appreciated that the fastening may be accomplished by means other than the gripping of rails  16 ,  18 . For example, other parts of trailer  4  may be gripped. Or, a mode of fastening other than gripping may be employed. What is important is that the frame fastener be configured to fasten frame  24  to the object. 
         [0026]    Preferably, the device  2  includes two wheel means attached to the device frame  24  and positioned so as to bear on sides  12 ,  14 , so that the wheel means roll along the sides to facilitate movement of the device along the object. In the preferred embodiment, there is a wheel means associated with each of the fastening elements  38 ,  40 , with each wheel means consisting of two wheels  42 . Preferably, wheel means  42  are positioned and rotatably attached to each fastening element ( 38 ,  40 ). As can be seen in  FIG. 3 , wheels  42  are positioned so as to bear on respective sides  12 ,  14 , and particularly, rails  16 ,  18 . 
         [0027]    It will be appreciated by those skilled in the art that the invention comprehends two types of locking, or fastening. First, the invention comprehends the use of the frame fastener to fasten the device frame  24  to the trailer body  6 . The purpose of such fastening is to allow a person working on roof  10  to attach worker safety gear to the device  2  to prevent falling and injury. However, even with the frame  24  fastened to trailer body  6  by the frame fastener, it is still possible to move the device frame  24  along the length of trailer  6 . This lengthwise or lateral movement along trailer  6  is important because it may be necessary for a worker to perform maintenance on one portion of the trailer, and then move safely to a different portion of the trailer and perform more maintenance there. Thus, in accordance with the present invention, a worker may fasten the device frame to trailer body  6  and perform work in the vicinity of the trailer adjacent to device frame  24 . When it is desired to perform maintenance on a different portion of trailer body  6 , the worker can push or pull device frame  24  along the length of trailer body  6  while the device frame  24  remains fastened to trailer body  6 . This provides safety to the worker even as the worker moves the device frame  24 . 
         [0028]    It will be appreciated that the invention comprehends other means for facilitating lateral movement of the device frame  24  along trailer body  6  besides the wheel means referred to above. For example, the lateral movement facilitating means may include low friction sliders (not shown), consisting of low friction pads. Such pads would preferably be made of a low-friction material, and like the wheel means, are positioned so as to bear against sides  12 ,  14 , and in particular indentations  20 ,  22 . Whatever form the means for facilitating lateral movement may take, it will be appreciated that such means preferably include a low-friction interface between device frame  24  (preferably fastening elements  38 ,  40 ), and the trailer body  6 , to allow for easy lateral movement of the device frame  24  along the trailer body  6 . 
         [0029]    On the other hand, it will be appreciated that while the capability for such lateral movement is preferred to permit movement for maintenance, repair, snow removal etc., and while having means for facilitating such lateral movement is preferred, the invention does not require the capability for such lateral movement. Rather, though not preferred, it is possible for a user to simply unfasten or detach the device  2  from the trailer body  6  when it is desired to move the device  2  along the length of the trailer body  6 . 
         [0030]    It will be appreciated that it is typical for fall-prevention safety equipment to include some kind of hook or carabiner which is meant to be attached to a fixed point to prevent a worker from falling. Therefore, the attachment means preferably comprises a hook-receiving element, most preferably in the form of ring  44 . Preferably, as can be seen in  FIGS. 1-3 , the ring  44  is attached to the joining plate  30 . 
         [0031]    It will be appreciated that the attachment means may take other forms. It may be curved, and may have an open or closed shape. What is important is to provide a means for attaching a fall prevention device. 
         [0032]    To use the device  8 , a worker would fasten the device  2  to the trailer body  6 . In the preferred embodiment, the worker climbing up to the roof  10  is initially positioned at one side of trailer  4 . The worker positions device  2  in a pre-fastening position above roof  10 . Preferably, the worker extends it across roof  10  so that the opposite end of device  2  (the opposite fastening element) grips the opposite rail. Then, the worker pulls the near side of the device  8 , so that the near fastening element is positioned off roof  10 . The adjacent fastening element is then gently released and elasticized cord  32  contracts to cause the near fastening element to grip the near rail. The device  2  and frame  24  are thus fastened to the trailer  4  by elasticized cord  32  to cause the fastening elements to fasten frame  24  to the side rails. Frame  24  can be removed or detached by pulling the near fastening element away from the opposite one against elasticized cord  32 , releasing the near fastening element from gripping the near rail and then removing the device  2  from roof  10 . 
         [0033]    It will be appreciated that the invention comprehends other modes of actuating the frame fastener to cause the fastening elements to fasten frame  24  to the side rails. For example, a strap connecting the frame elements may be retracted to pull the fastening elements together to fasten the frame  24  to rails  16 ,  18 . 
         [0034]    After fastening, the worker would attach a fall arrest device or safety harness, to which he himself is attached, to ring  44 . Then, in the event that the worker were to be in danger of falling (e.g. the worker trips or stumbles, and is about to fall off of roof  10 ), his fall arrest device would act as a brake. Meanwhile, the fall arrest device is attached to device frame  24 , which is in turn fastened to trailer body  6 , with the result that the worker would be prevented from falling off of roof  10  and to the ground, and would be saved from the attendant injury. 
         [0035]    Preferably, the ring  44  is positioned approximately midway along the length of device frame  24 , and thus, approximately equidistant from the sides  12 ,  14  when the device frame  24  is fastened to the trailer body  6 . This positioning is preferred because it maximizes the area of roof  10  that a worker can reach while his fall-prevention gear is attached to ring  44 . 
         [0036]    It will be appreciated that the attachment of the ring  44  to the frame  24  at opposed ends  38 ,  40 , though preferred, is not required. Other modes of attachment are comprehended by the invention. The above-described form of attachment is preferred because it has been found that having two widely distributed attachment points distributes the force on those attachment points, and on the device frame  24 , in a beneficial manner in the event that a worker is falling and is thus exerting a force on the device frame  24 . By having the ring  44  attached to the frame  24  at the opposed ends  38 ,  40 , the force on the frame  24  acts at points adjacent to the fastening points of the device frame  24  to the trailer body  6 . Thus, the amount of twisting force and torque applied to the device frame  24  is reduced, thus reducing the risk that the device would not operate properly. 
         [0037]    Furthermore, distributing the points at which the attachment means is attached to the device frame  24  is beneficial, in that it is less likely that the attachment means will undesirably come off of the device frame  24 . 
         [0038]    It will further be appreciated that the attachment means may take other forms besides the embodiments described above. What is important is that the attachment means be attached to the device frame and be configured and positioned to attach the fall arrest device to the device frame. 
         [0039]    The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.