Abstract:
A rack for the transport of thin wall parts such as automotive body panels stampings has a steel frame with two parallel channels positioned on either side of a planar floor member. Each channel has a series of parallel slots which receive tabs extending downwardly from parallel plastic leaves. The leaves are restricted from removal from the rack by rods which extend through the frame beneath the channels and through rod openings in the tabs. The plastic leaves are of two types having side structures which do not nest. Because the leaves are not hinged to the floor member, they will stay in either position due to gravity. The non-nesting leaf side structures permit a plurality of leaves to be flipped from one position to the other simultaneously.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
         [0001]    Not applicable.  
         STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT  
         [0002]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    The present invention relates to racks for the transport of thin wall parts in general, and more particularly to racks which have the capacity to be loaded and unloaded at the top sides.  
           [0004]    Many sheet metal stampings, plastic panels, and composite carbon fiber panels go into the construction of an automobile. In particular, exterior body panels are often formed of thin wall parts. The parts are fabricated, for example, in stamping mills, and are then transported to assembly lines where the panels are assembled and painted. Because many of these stamped parts are visible to the customer, it is imperative that they be free of scratches, dings, or distortions. At the same time, for efficient transport and assembly it is desirable that these parts be readily and conveniently accessible, while also being protected from contact with exterior objects or with other adjacent parts.  
           [0005]    U.S. Pat. No. 4,976,092 discloses a rack having a steel frame open to the top and sides, and having a horizontal plywood board to which a series of parallel plastic leaves are connected by living hinges which are screwed in place. The plastic leaves are formed as single sheet thermoformed thermoplastic parts which have projecting edge portions which allow the edges of adjacent leaves to nest. This rack receives individual metal parts between pairs of plastic leaves. The rack is loaded with parts at the place of manufacture, then transported on a forklift vehicle, for loading and transport to eventually reach its final destination where the metal parts are removed. Although such a rack provides advantageous clearance for side loading, it provides certain deficiencies. Because the leaves are hinged directly to the plywood board, they have a tendency to return to an initial orientation, rather than remaining where positioned. In addition, the nesting edge portions can cause the adjacent leaves to lock together to prevent multiple leaves from being flipped at once between loading and transport positions. Moreover, as the plastic leaves must be replaced from time to time to reconfigure the rack for new parts, the removal and reattachment of the leaves to the plywood board is laborious and time-consuming, and costly in terms of additional fasteners required.  
           [0006]    What is needed is a side or top loading part rack which is rapidly assembled, easily operated, easily maintained and which avoids locking or interference of adjacent leaves when being turned in groups.  
         SUMMARY OF THE INVENTION  
         [0007]    A rack for the transport of thin wall parts such as automotive body panels stampings has a steel frame with two parallel channels positioned on either side of a planar floor member. Each channel has a series of parallel slots which receive tabs extending downwardly from parallel plastic leaves. The leaves are restricted from removal from the rack by rods which extend through the frame beneath the channels and through rod openings in the tabs. The plastic leaves are of two types having side structures which do not nest. Because the leaves are not hinged to the floor member, they will stay in either position due to gravity. The non-nesting leaf side structures permit a plurality of leaves to be flipped from one position to the other simultaneously.  
           [0008]    It is an object of the present invention to provide a rack for metal stampings having a plurality of plastic leaves which are readily removed and replaced.  
           [0009]    It is another object of the present invention to provide a rack for metal stampings in which multiple plastic leaves may be pivoted simultaneously without interference between each other.  
           [0010]    It is also an object of the present invention to provide a rack for metal stampings in which individual plastic leaves remain where positioned and do not have a tendency to return to an initial position.  
           [0011]    It is a further object of the present invention to provide a rack which eliminates any hinged connection between the plastic leaves and the rack.  
           [0012]    Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is an exploded isometric view of the rack of this invention.  
         [0014]    [0014]FIG. 2 is a cross-sectional view of the rack of FIG. 1, a first leaf being partially broken away to reveal a second leaf having different side structure.  
         [0015]    [0015]FIG. 3 is a cross-sectional view of the rack of FIG. 2 taken along section line  3 - 3 .  
         [0016]    [0016]FIG. 4 is a fragmentary cross-sectional view of a leaf of the rack of FIG. 2 shown in relation to a frame channel illustrated in phantom view. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    Referring more particularly to FIGS.  1 - 4 , wherein like numbers refer to similar parts, a rack  20  is shown in FIG. 1. The rack  20  has a steel frame  22  which has two parallel channels  24  positioned on either side of a planar floor member  26 . Each channel has a series of parallel slots  28  which receive tabs  30  which extend downwardly from plastic leaves  32 . The leaves  32  are restricted from removal from the frame  22  by rods  34  which extend through rod openings  36  in the tabs  30 .  
         [0018]    The frame  22  has a base structure  38  comprised of square and rectangular metal tubing  44  welded together to provide four way entry openings  40  adapted to receive the protruding tines of a forklift vehicle. Four corner posts  42  extend upwardly from the frame base structure  38 . The height of the corner posts  42  is determined by the size of the parts to be accommodated by the rack  20 , but will generally be between 12 and 100 inches tall. Inclined ramps  46  are fixed to the front corner posts. The ramps  46  support the inclined leaves  32  when they are loaded with sheet metal or other thin wall parts  48 . The leaves are also supported by two angled front plates  50  which are fixed to a front crossbar  52 , a front horizontal member  54  which extends rearwardly from the front crossbar  52 , and a front bar  56  which extends upwardly from the base structure  38  rearward of the horizontal member  54 . This front structure serves to maintain the parallelism of the panels during shipment, and the particular arrangement of ramps, angled front plates, or bars will vary depending on the geometry of a particular part to be transported.  
         [0019]    The channels  24  may be formed of ⅛ to ¼ inch thick sheet. As shown in FIG. 1, the channels  24  are fixed to the base structure  38  of the frame  22 . As shown in FIG. 4, each channel has a top wall  58  which has portions defining an array of parallel slots  28 . The two channels  24  are positioned such that the slots of one channel are aligned with the slots of the other. The channel top wall  58  is spaced above the base structure  38  by two parallel channel side walls  60  which have outwardly extending flanges  62  which are fixed to the base structure  38  such as by welding. Each slot is about five inches wide, and the slots are separated from each other on about 2.5 inch centers. However, the spacing or index of the slots may range from 1 to 5 inches. Each slot is approximately three times the thickness of the plastic at the tab, thus for a ⅛ inch thick tab as illustrated, the slot is about ⅜ inch wide.  
         [0020]    The floor member  26  extends between the two channels  24  and has a top surface which is at approximately the same level as the top wall  58  of the channels. The floor member  26  may be composed of two strips  64  of three-quarter inch plywood which extend in the front to back direction and which are fastened to the base structure  38 , and a single sheet  66  of one-half inch plywood which is fastened to the strips.  
         [0021]    The two rods  34  may be one-half inch diameter solid steel rods which taper to {fraction (3/16)} inches in diameter at one-half inch long tapered ends  68 . The front beam  70  and the rear beam  72  of the base structure  38  are provided with oblong holes  74  through which the rods  34  are inserted within the channels  24 . Flanges  76  extend downwardly at the front and rear of the channels  24 , as shown in FIG. 2, and have circular or oblong slots routed or punched therein through which the rods  34  extend. In addition, a downwardly extending plate with a similar sized slot in is welded extending downwardly from the channel top walls  58  at a position approximately centered between the front and the rear of each channel  24 . When received within the slots in the flanges  76  and the center plates, the rods  34 , which may be about 86 inches long, are restrained from excessive bending. Once the rods are positioned to extend through the openings in the leaf tabs  30 , cotter pins  77  are inserted through {fraction (3/16)} inch diameter holes in the ends of the rods to restrain the escape of the rods from the frame. It should be noted that the rods may also be fabricated from non round parts, and from tubular parts.  
         [0022]    As shown in FIG. 2, each leaf  32  has two downwardly extending tabs  30 , as best shown in FIG. 4, which are received within a pair of slots  28  in the opposed channels. Each leaf  32  is configured with customized dunnage structure  78 . The dunnage structure  78  may be an arrangement of protrusions and recesses configured to engage and retain a particular metal part  48  between the leaves  32 . For example, semicircular shells  80  may have slots routed in them to retain the lower edges of the sheet metal parts  48 . In any event, the dunnage structure  78  may very depending upon the type of part which is intended to be conveyed within the rack  20 .  
         [0023]    When the leaves  32  are formed as single sheet thermoformed parts, every projection on one surface has a corresponding recess on the opposed surface. In the prior art racks, this relationship between adjacent leaves resulted in nesting engagement between leaves in the course of pivoting a leaf from a loaded to an unloaded position. When the leaves nested—generally at the position perpendicular to the floor—adjacent leaves would become locked together and would pivot no further. Hence, to avoid this nesting, it became necessary to pivot the leaves one by one. The rack  20  of this invention eliminates entirely this tendency to lock and permits simultaneous pivoting of groups of leaves. Nesting is eliminated by providing nonidentical molded leaves  32 : a first leaf  82  which has side margins  83  which project frontwardly from a flange around the dunnage structure, and a second leaf  84  which has side margins  86  which project rearwardly from a flange around the dunnage structure. The dunnage structure is substantially the same on both the first leaves  82  and the second leaves  84 . The leaves are interspersed on the frame alternating between a first leaf  82  and a second leaf  84 . As shown in FIG. 3, the result of this arrangement is that the frontwardly protruding side margins of each first leaf  82  will engage against the rearwardly protruding side margins of a preceding second leaf  84 . Moreover, the flanges from which the side margins protrude will engage against each other without nesting, to permit unhindered sliding movement between adjacent side margins as the leaves are pivoted in groups from one working position to the other.  
         [0024]    As shown in FIG. 4, each leaf has three ribs above each tab, which help to stiffen the leaf in the vicinity of the tab, to carry loads away from the tab, and to support the leaves at a desired repose angle in both the loaded and unloaded positions. A center rib  88  projects rearwardly, while two side ribs  90  project frontwardly, one on each side of the center rib. The lower edges of the ribs  88 ,  90  are positioned at approximately the same level as the lower margin  94  of the leaf adjacent to the tabs  30 . The lower margin  94  of each leaf is generally supported on the top surface  92  of the floor member  26 .  
         [0025]    As shown in FIG. 3, the leaves  32  are each movable between two positions of repose. In a first unloaded position, the leaves are inclined toward the rear of the rack  20 , and toward a brace assembly  96  mounted to a rear cross bar  98  which extends between the rear corner posts  42 . In the unloaded position, each leaf is inclined from the horizontal plane of the top walls  58  of the channels  24 . The second, loaded, position is rotated from approximately 10° to 60° from the first position, into a position in which the tabs  30  are inclined slightly toward the front of the rack. The amount of inclination will vary depending on the transported part. In the first unloaded position, the center rib  88  will generally be close to or engaging the top wall  58  of the channels  24 , while in the second loaded position, the side ribs  90  will generally be close to or engaging the top wall of the channels.  
         [0026]    The rack  20  will typically be used in a manufacturing facility in proximity to a source of formed sheet metal parts  48 . In its initial setup, all but the first leaves  32  are pivoted toward the rear of the rack, in the unloaded position. The first leaf  32  is pivoted toward the front of the rack in the loaded position. The first part  48  is positioned inclined against the first leaf  32 , with the lower edge of the part  48  being restrained by the semicircular shells  80 . The second leaf  32  is then pivoted from the unloaded to the loaded position to overlie the first leaf and to surround the part  48 . The edge structure and other protrusions of the dunnage structure  78  protect the part  48  and prevent its contact with other parts. These steps are repeated until each leaf  32  is loaded with a part  48 . Then, the brace assembly  96  is pivoted toward the front of the rack to restrain all the leaves in the loaded position.  
         [0027]    As shown in FIG. 1, the brace assembly  96  has two upwardly extending members  100  connected by a cross member  102 . The lower ends of the members  100  are mounted by pins to brackets  104  which project frontwardly from the rear crossbar  98 . One of the upwardly extending members  100  has a spring-loaded pin is extendable into a pin hole in one of the brackets  104  and which which retains the brace assembly in a nonengaged position during loading of the parts. A toothed cam  106  extends frontwardly from the rear crossbar  98  alongside one of the upwardly extending members  100 . Another spring-loaded pin  108  is fixed to an upwardly extending member  100 , and acts as a ratchet against the toothed cam  106  to allow the brace assembly to be pressed down to engage the loaded leaves. During shipment the parts may shift or compress, which could allow a front to back movement of the parts. The weight of the cross member  102  can automatically cause the brace assembly  96  to ratchet into tighter engagement to take up any looseness.  
         [0028]    It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.