Patent Publication Number: US-7222903-B2

Title: Spreader bar apparatus

Description:
STATEMENT OF GOVERNMENT INTEREST 
   The invention described herein may be manufactured and used by the U.S. Government for Governmental purposes without the payment of any royalties thereon. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to a new and improved spreader bar for use in lifting operations. 
   2. Description of the Related Art 
   Spreader bars are commonly used in industry for lifting large objects with a single hook that is attached to the lift cables of a helicopter, crane or other lifting device. A lifting hook is commonly provided with a pair of slings that depend from the helicopter or crane hook at angles in a bridle fashion. Each of the slings contacts a respective end portion of the spreader bar and then continues downwardly wherein it is attached to a load that is to be lifted. 
   One particular problem with spreader bars relates to the size of the spreader bar relative to the particular load that is to be lifted. Some prior art spreader bars have telescoping sections to adjust the spreader bar to different lengths to accommodate different loads. Such telescoping spreader bars have operated well in lifting relatively light loads of a few thousand pounds but have exhibited problems in lifting very heavy loads. Another problem of prior art spreader bars is related to transportation and storage of the spreader bar. Many prior art spreader bars are extremely heavy when compared to the strength of an average worker. Therefore, it is difficult for a single worker to move, lift and transport many of the prior art spreader bars. 
   The prior art reveals several different spreader bar apparatuses and similar devices. U.S. Pat. Nos. 6,079,760 and 6,296,288 disclose a spreader bar that comprises a plurality of bar sections that are connected end-to-end to form a lifting bar with a central longitudinal axis and with left and right end bar end members. U.S. Pat. No. 6,412,649 discloses a spreader bar that includes an elongated bar member that has end portions which support a flexible lifting member. U.S. Pat. No. 5,863,085 discloses a spreader bar that has a rigid elongated support bar. End caps are connected to the rigid elongated support bar in order to use the spreader bar in a lifting operation. The end caps have sockets that fit over the ends of the bar. U.S. Pat. No. 5,716,088 discloses a lifting frame and a single-piece spreader bar. The end caps have sockets that fit over the ends of the bar. U.S. Pat. No. 5,603,544 discloses compression cap assemblies that are used with the ends of a spreader bar. U.S. Pat. No. 4,842,314 discloses a pipe lift cap assembly comprising a pair of first and second cap members that can be removably attached to respective ends of a pipe or casing. The end caps have sockets that fit over the ends of the bar. U.S. Pat. No. 4,538,849 discloses a spreader bar assembly that has a pair of separate elongated spreader bars. Each spreader bar is supported independently by alternate radially branching lines. U.S. Pat. No. 4,397,493 discloses a spreader bar assembly that utilizes a single rigid member. U.S. Pat. No. 3,829,145 discloses a spreader bar extension that comprises a rectangular upper framework. U.S. Pat. No. 2,020,174 discloses a vehicle hoist frame that comprises two tubular rods that are interconnected at the center by a pivot. Each tubular rod has a plate-disc at the center of the tubular rod. Each disc has a slot in the shape of the arc of a circle. 
   What is needed is a new and improved spreader bar apparatus that has the required strength for military and commercial applications, but which is compact, light-weight and relatively inexpensive to manufacture. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a spreader bar apparatus. The spreader bar has an elongate central member having a hollow interior, and a pair of elongate end members wherein each elongate end member is partially disposed within the hollow interior of the central elongate member so that a first portion of the elongate end member is within the hollow interior of the elongate central member and a second portion of the elongate end member is external to the hollow interior. The second portion of each elongate end member extends to a distal end. The spreader bar has a pair of sling guides wherein each sling guide is attached to the distal end of a corresponding elongate end member. The first portion of each elongate end member has an end that is located within the hollow interior of the elongate central member. These ends of the first portions of the elongate end members abut one another so as to cause compressive forces to be translated through the entire spreader bar. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is perspective view of the spreader bar apparatus of the present invention. 
       FIG. 2  is a top view of the spreader bar apparatus of  FIG. 1 . 
       FIG. 3  is an enlarged view of a portion of the view shown in  FIG. 1 . 
       FIG. 4  is an enlarged view of a guide member shown in  FIG. 1 . 
       FIG. 5  is partial view, in perspective, of an elongate end member shown in  FIG. 1 . 
       FIG. 6  is perspective view of an elongate central member shown in  FIG. 1 . 
       FIG. 7  is a partial view, in cross-section, showing portions of the elongate end members disposed in the hollow interior of the central member. 
       FIG. 8  is side-elevational view showing the spreader bar apparatus of the present invention being used in a lifting operation. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In the description of the invention various embodiments and/or individual features are disclosed. As will be apparent to the ordinarily skilled practitioner, all combinations of such embodiments and features are possible and can result in preferred executions of the invention. 
   Referring to  FIGS. 1 ,  2 ,  3 ,  6  and  7 , there is shown spreader bar  10  of the present invention. Spreader bar  10  comprises elongate central member  12  which has hollow interior  14  and opposite distal end portions  16  and  18 . Each distal end portion  16  and  18  defines an opening, one of which being opening  18  while the other opening is not shown, in communication with hollow interior  14 . Spreader bar  10  further comprises a pair of elongate end members  20  and  22 . Elongate end member  20  has portion  23  that is disposed within hollow interior  14  of elongate central member  12  and portion  24  which is external to hollow interior  14  (see  FIG. 7 ). Similarly, elongate end member  22  has portion  25  that is disposed within hollow interior  14  and portion  26  that is external to hollow interior  14 . Elongate end member  20  has distal end  27  external to hollow interior  14  and end  28  within hollow interior  14 . Similarly, elongate end member  22  has distal end  29  external to hollow interior  14  and end  30  within hollow interior  14 . In accordance with the invention, ends  28  and  30  of elongate end members  20  and  22 , respectively, abut one another so as to cause compressive forces that are produced by a sling line attached to a load in a lifting operation to be translated throughout the entire spreader bar  10 , i.e. elongate end members  20  and  22 . 
   Referring to  FIGS. 1-7 , in a preferred embodiment, elongate central member  12  and elongate members  20  and  22  are substantially tubular in shape and have a generally circular cross-section. However, it is to be understood that elongate central member  12  and elongate members  20  and  22  can have other suitable cross-sectional shapes, e.g. square, oval, rectangular, triangular, etc. 
   Referring to  FIGS. 3 ,  5  and  6 , spreader bar  10  further comprises a locking system to prevent elongate end members  20  and  22  from being dislodged from hollow interior  14  of elongate central member  12 . In one embodiment, the locking system comprises a plurality of pairs of diametrically positioned openings  40  in elongate central member  12 , and a plurality of pairs of diametrically positioned openings  42  in each elongate end member  20  and  22 . Due to the particular views shown in  FIGS. 5 and 6 , the openings located in the bottom sides of elongate central member  12  and elongate end members  20  and  22  are not shown. Each pair of diametrically positioned openings  40  in elongate central member  12  are substantially aligned with a corresponding pair of diametrically positioned openings  42  in elongate end members  20  and  22 . The locking system further comprises a plurality of pin members  44 . Each pin member  44  is removably disposed through a corresponding pair of diametrically positioned openings  40  in elongate central member  12  and a corresponding pair of diametrical positioned openings  42  in either elongate end member  20  or elongate end member  22 . Each pin member  44  has distal end  46  that is exposed when pin member  44  is disposed though diametrically positioned openings  40  of the elongate central member  12  and diametrically positioned openings  42  of end members  20  and  22  (see  FIGS. 1 ,  6 ,  7  and  8 ). Each pin member  44  has opening  47  adjacent distal end  46 . The locking system further comprises a plurality of locking members  48 . Each locking member  48  is disposed through an opening  47  of a corresponding pin member  44  so as to prevent each pin member  44  from becoming dislodged from diametrically positioned openings  40  of elongate central member  12  and diametrically positioned openings  42  of elongate end members  20  and  22 . In one embodiment, each locking member  48  comprises a cotter pin. The locking system further comprises a plurality of ties  50 . Each tie  50  has a first end that is attached to elongate central member  12  with fastener  52 . Fastener  52  can be any suitable device such as a rivet, screw, bolt, etc. Another portion of each tie  50  is attached to a corresponding pin member  44 . In one embodiment, each tie  50  is threaded through a cavity (not shown) in a corresponding pin member  44 . Each tie  50  also has a second end that is attached to a corresponding locking member  48 . Tie  50  prevent pin members  44  and locking members  48  from being separated from spreader bar apparatus  10  or otherwise lost or misplaced. In one embodiment, each tie  50  comprises a wire lanyard. The locking system secures elongate end members  20  and  22  within hollow interior  14  of elongate central member  12  and prevents elongate end members  20  and  22  from becoming dislodged from hollow interior  14 . In order to remove elongate end members  20  and  22  from hollow interior  14 , locking members  48  must first be removed from all openings  47  in pin members  44 . Next, pin members  44  are then be withdrawn from diametrically positioned openings  40  and  42 . Elongate end members  20  and  22  can then be removed from hollow interior  14  of elongate central member  12 . 
   Referring to  FIGS. 1 ,  2 ,  4 ,  5  and  8 , spreader bar  10  comprises a pair of sling guide members  70  and  72 . Sling guide member  70  is attached to end  27  of elongate end member  20  and sling guide member  72  is attached to end  29  of elongate end member  22 . Sling guide member  70  comprises a pair of guide plates  74  and  76  that are arranged in a generally vertical orientation. Sling guide member  70  further comprises generally smooth, rounded and downwardly sloping contact surface  78  that is between guide plates  74  and  76 . Contact surface  78  is free of any burrs or surface aberrations that can cause damage to a sling line. During a lifting operation, guide plates  74  and  76  contain the sling line therebetween so that the sling line contacts contact surface  78 . Guide plates  74  and  76  have aligned openings (not shown) for receiving pin member  80  which maintains the sling line between guide plates  74  and  76 . A locking member  82  is removably disposed within an openings (not shown) in pin member  80  to prevent pin member  80  from being dislodged from the openings (not shown) in guide plates  74  and  76 . In one embodiment, locking member  82  comprises a cotter pin. 
   Similarly, sling guide member  72  comprises a pair of guide plates  90  and  92  that are arranged in a generally vertical orientation. Sling guide member  72  further comprises generally smooth, rounded and downwardly sloping contact surface  94  that is between guide plates  90  and  92 . Contact surface  94  is free of any burrs or surface aberrations that can cause damage to a sling line. During a lifting operation, guide plates  90  and  92  contain the sling line therebetween so that the sling line contacts contact surface  94 . Guide plates  90  and  92  have aligned openings (not shown) for receiving pin member  98  which maintains a sling line between guide plates  90  and  92 . Locking member  100  is attached to pin member  98  to prevent pin members  98  from being dislodged from the openings (not shown) in guide plates  90  and  92 . In one embodiment, locking member  100  comprises a cotter pin. 
   Referring to  FIGS. 1 ,  2 ,  4 ,  5  and  8 , sling guide member  70  comprises tie  102  which has one end attached to guide plate  76  with fastener  104 . Fastener  104  can be any suitable device such as a screw, rivet, bolt, etc. Tie  102  is threaded through a cavity (not shown) in the top portion of pin member  80 . In an alternate embodiment, tie  102  is rigidly attached to pin member  80 . The other end of tie  102  is attached to locking member  82 . Tie  102  prevents pin member  80  and locking member  82  from being separated from spreader bar  10  or otherwise misplaced or lost. In one embodiment, tie  102  comprises a wire lanyard. Similarly, sling guide member  72  comprises tie  106  which has one end attached to guide plate  92  with fastener  108 . Fastener  108  can be any suitable device such as a screw, rivet, bolt, etc. Tie  106  is threaded through a cavity (not shown) in the top portion of pin member  98 . In an alternate embodiment, tie  106  is rigidly attached to pin member  98 . The other end of tie  106  is attached to locking member  100 . Tie  106  prevents pin member  98  and locking member  100  from being separated from spreader bar apparatus  10  or otherwise misplaced. In one embodiment, tie  104  comprises a wire lanyard. 
   Referring to  FIGS. 1 and 2 , spreader bar  10  can be made out of a variety of materials, e.g. steel, aluminum, composite materials. In a preferred embodiment, spreader bar  10  is fabricated from metal. More preferably, spreader bar  10  is fabricated from aluminum. If spreader bar  10  is fabricated from steel, it is preferable that a non-corrosive coating be applied to the steel. 
   Referring to  FIG. 8 , there is shown spreader bar  10  during a lifting operation. Sling line  110  is carried by hook  112  that is attached to a lift line (not shown) which is suspended by a lifting machine such as a crane or helicopter (not shown). Sling line  110  is attached to load  114  by any suitable means and is positioned between the guide plates of each sling guide member  70  and  72  as described in the foregoing description. The compressive force exerted by sling line  110  on spreader bar  10  is translated throughout the entire spreader bar  10 . 
   EXAMPLE 
   A spreader bar was constructed in accordance with the present invention. The spreader bar  10  was constructed so that elongate central member  12  had a length of 50 inches and the overall length of the spreader bar  10  was 100 inches. Elongate central member  12  had an inner radius of 1½ inches and an outer radius of 1 11/16 inches. Each elongate end member  20  and  22  had an inner radius of 1¼ inches and an outer radius of 1 7/16 inches. The guide plates of each sling guide member  70  and  72  were spaced apart by 2 inches. Each guide plate  74 ,  76 ,  90  and  92  had a length L (see  FIG. 4 ) of 4 inches. The total weight of spreader bar was 26 lbs. During testing, a compressive load of 28,000 lbs. was applied to the spreader bar. The spreader bar performed satisfactorily without deformation, bending or damage. 
   Although the preceding example describes specific dimensions, it is to be understood that such dimensions apply to one particular embodiment of the invention and that other suitable dimensions can be used as well. Furthermore, the preceding example describes a compressive force of 28,000 lbs. that was applied to the spreader bar. However, it is to be understood that the spreader bar of the present invention can be used in situations wherein the compressive force exceeds 28,000 lbs. 
   Spreader bar apparatus  10  provides several advantages and benefits. For example, since ends  28  and  30  of elongate end members  20  and  22 , respectively, are in an abutting relationship within hollow interior  14  (see  FIG. 7 ), compressive forces caused by sling lines attached to a load are translated throughout the entire spreader bar  10 . Thus, spreader bar  10  does not rely on the shear strength of bolts and pins, but rather, relies on the strength of the entire spreader bar thereby increasing the capabilities of spreader bar  10 . Furthermore, spreader bar  10  is relatively lighter in weight than most conventional or prior art spreader bars thereby providing ease of use, transportation and storage. Additionally, sling guide members  70  and  72  allow spreader bar  10  to be used for multiple purposes. Spreader bar  10  can be used on crane lifts as well as helicopter lifts. Spreader bar  10  is relatively less expensive to manufacture in comparison to most conventional or prior art spreader bars. Another important advantage of spreader bar  10  is that it can be easily disassembled for purposes of transportation and/or storage. A user can simply remove locking pins  48  from pin members  44 , remove pin members  44  from openings  40  and  42 , and then remove elongate end members  20  and  22  from the hollow interior  14  of elongate central member  12 . 
   The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular forms disclosed, as these are to be regarded as illustrative rather than restrictive. Variations in changes may be made by those skilled in the art without departing from the spirit of the invention. Accordingly, the foregoing detailed description should be considered exemplary in nature and not limited to the scope and spirit of the invention as set forth in the attached claims.