Abstract:
Conveyor system accessories are disclosed, which provide an inexpensive way to stage, stockpile and/or sort work pieces and provides easy entry to and exit from a main conveyor. In particular, a trolley or trolleys that carry work pieces ride on the conveyor rail above the chain or intermesh with the chain on the inside of the track. These accessories are used with single track continuous conveyor systems, which greatly enhances the productivity of the single track system by permitting work pieces to be taken off-line without taking the work piece off a load pendant.

Description:
RELATED APPLICATION 
     This application is a division application of U.S. application Ser. No. 09/818,460 filed Mar, 27, 2001 now U.S. Pat. No. 6,588,579. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates, generally, to novel conveyor system accessories for loading and unloading a work piece from a conveyor system. The present invention provides an inexpensive way to stage, stockpile and/or sort work pieces and provides easy entry to and exit from a main conveyor. Alternatively, work pieces may reenter the main conveyor, if desired. Specifically, a trolley or trolleys that carry work pieces ride on the conveyor rail above the chain or intermesh with the chain on the inside of the track. These accessories are used with single track continuous conveyor systems, which greatly enhances the productivity of the single track system by permitting work pieces to be taken off-line without taking the work piece off a load pendant. 
     2. Description of the Related Art 
     Conventional overhead trolley carriers are known in the art. One such type is a continuous flow conveyor. The continuous flow conveyor is restricted by a moving chain, which severely limits the utility of this type of conveyor. Specifically, when it is necessary to remove a work piece from the conveyor it is necessary to take it off a load pendant. Generally, the removal of the work piece from the load pendant requires disengagement of the conveyor drive train, thus stopping motion of the conveyor. Alternatively, if complete stoppage of the conveyor is to be avoided, the conveyor must be slowed down considerably to facilitate the removal of the work piece from the load pendant. Both methods of unloading, however, greatly impact the productivity of the conveyor system. 
     More recently, power and free conveyor systems have been developed to overcome the problems associated with the staging, stockpiling, and/or sorting of work pieces in continuous flow conveyors. Power and free systems have a power track and a carrier track arranged in vertically spaced relation. The power track is an endless chain supported by trolleys mounted on the power track, and longitudinally spaced pushers carried by the chain. A pusher is engageable with a driving dog on the front end of a load carrier, and disengaging means associated with the driving dog is operable by actuating means on the rear end of a preceding load carrier so that successive load carriers can automatically accumulate behind a stopped load carrier. Power and free conveyors overcome many of the problems associated with continuous flow conveyors. These power and free conveyors are, however, generally more than twice as expensive as continuous flow conveyors. 
     In view of the prior art at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the needed inexpensive yet efficient staging, stockpiling, and/or sorting conveyor system could be provided. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a single track continuous conveyor system accessory is provided. In one embodiment of the present invention the conveyor system accessory is a wheel assembly for riding on top of an inverted continuous conveyor track. The wheel assembly has a pair of wheels, which are spaced apart in a parallel side by side relationship and are connected to one another by a transverse axle. A drive means for a conveyor chain is positioned in the inverted continuous conveyor track to engage the wheel assembly and move it in a desired direction. A carrying means for transporting a work piece is rotatably attached to the wheel assembly. The present invention also includes a loading means for positioning the wheel assembly on the top surface of the inverted continuous conveyor track and an unloading means for removing the wheel assembly from the top surface of the inverted continuous conveyor track. 
     A second wheel assembly is provided for the transport of heavy loads and is used in conjunction with the wheel assembly. In particular, the second wheel assembly has a second pair of wheels, which are spaced apart in a parallel side by side relationship and are connected to one another by a second transverse axle. The second wheel assembly is connected to the wheel assembly by a pair of longitudinal members with one end of each pair of longitudinal members rotatably connected to the transverse axle and an opposite end of each pair of longitudinal members rotatably connected to the second transverse axle. Loading means and unloading means are also provided for positioning and removing the combination of the wheel assembly and second wheel assembly on and from the inverted continuous conveyor track, respectively. 
     The conveyor system accessory may also include an alignment means for maintaining the wheel assembly and the combination of the wheel assembly and the second wheel assembly on the top surface of the inverted continuous conveyor track. The alignment means is a plate which is fixedly attached to each of the wheels of the pair of wheels of the wheel assembly and the second wheel assembly. The plates are situated on an external surface of each of the wheels, are perpendicular to the transverse axle, and extend beyond each wheel and overlap a portion of both sides of the inverted continuous conveyor track to form a boundary means for maintaining the wheel assembly in combination with the second wheel assembly on the top surface of the inverted continuous conveyor track. 
     The present system also provides a drive means, which is a vertically oriented elongate planar shaped member that is fixed at one end to the conveyor chain. The opposite end has notches on both sides for engaging the transverse axle of the wheel assembly in combination with the second transverse axle of the second wheel assembly. 
     In an alternative embodiment the wheel assembly meshes with the inverted continuous conveyor track. In this embodiment, the wheel assembly defines an inverted V-shaped assembly having a transverse member across an apex of the V-shaped assembly. The transverse member has rollers on either side of the apex for rolling on a ramp. The inverted V-shaped assembly is attached to a housing, which has a pair of wheels at its front end and a pair of wheels at its rear end. The pairs of wheels are spaced apart in a parallel side by side relationship and are connected to the housing. A drive means is positioned in the inverted continuous track and engages the wheel assembly and moves the wheel assembly in a desired direction. A carrying means for transporting a work piece is rotatably attached to the wheel assembly. Loading and unloading means for facilitating the intermeshing and disengagement, respectively, of the wheel assembly are also provided. 
     The housing of the present invention is an inverted U-shaped assembly with a cut out or slot portion for engagement of the drive means. The inverted U-shaped member allows the respective pairs of wheels of the wheel assembly to straddle a drive portion of the drive means and effectively intermesh with the drive means. 
     In yet a further embodiment, a wheel assembly for riding on a top surface of an inverted continuous conveyor track has a pair of V-shaped rollers. The V-shaped rollers are spaced apart and aligned to engage the upper most corners of the inverted continuous conveyor track and are fixedly attached to a V-shaped angle member by a transverse axle. A drive means is also provided. The drive means engages the V-shaped angle member and moves the wheel assembly in a desired direction. The wheel assembly has a carrying means for transporting a work piece, which is rotatably attached to the wheel assembly. Loading and unloading means are provided. 
     The invention accordingly comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the following description, taken together with the accompanying drawings, and its scope, will be pointed out in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature of the invention, reference should be made to the following detailed description; taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a side view of a dual axle conveyor system accessory of the present invention; 
     FIG. 2 is an end view or cross section of FIGS. 1,  3 ,  4 , and  5 ; 
     FIG. 3 is a side view of a single axle conveyor system accessory of the present invention; 
     FIG. 4 is a top plan view of the single axle conveyor system accessory of FIG. 3; 
     FIG. 5 is the side view of the dual axle conveyor system accessory of FIG. 1, without an angle iron guide; 
     FIG. 6 is a top plan view of the dual axle conveyor system accessory of FIG. 1 entering a main conveyor from staging; 
     FIG. 7 is a further top plan view of the conveyor system accessory of FIG. 1 with the conveyor chain removed for clarity; 
     FIG. 8 is a side view of an internal part carrier conveyor system accessory of the present invention; 
     FIG. 9 is isometric view of the wheel assembly of FIG. 8; 
     FIG. 10 is a cross-section of the conveyor system accessory of FIG. 8, taken alone lines  10 — 10  thereof with the entrance ramp removed for clarity; 
     FIG. 11 is the side view of the conveyor system accessory of FIG. 1 showing an unloading or exiting means; 
     FIG. 12 is a side view of another conveyor system accessory of the present invention; 
     FIG. 12 a  is a cross section of a conveyor system accessory of FIG. 12; 
     FIG. 12 b  is a further side view of FIG. 12 showing a push bar moving a part carrier on the rail with the rear wheels removed for clarity; 
     FIG. 12 c  is a isometric view of FIG. 12; 
     FIG. 13 is a cross section of a conveyor system accessory of the present invention with supports and top angle iron guides; and 
     FIG. 14 is a cross section of yet another conveyor system accessory of the present invention with supports and no top angle iron guide. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The conveyor system accessories of the present invention can be used with any commercially available single track continuous conveyor, such as those available from Rapid Industries, Inc. Louisville, Ky., Richards-Wilcox, Inc., Aurora, Ill., and Webb Inc., Farmington Hills, Mich. For purposes of the present invention the conveyor track is installed in an inverted position. Referring now to the drawings, in which like numerals refer to like elements thereof, FIG. 1, shows an embodiment of the invention denoted as a whole by reference numeral  100 . 
     As shown in FIGS. 1 and 5, a wheel assembly  8  in combination with a second wheel assembly  28  rides on a top surface  16  of an inverted continuous conveyor track  2 . Plan views of this embodiment are shown in FIGS. 6 and 7. Each of the first wheel assembly  8  and the second wheel assembly  28  has a pair of wheels  10  and a second pair of wheels  30 , respectively. The pair of wheels  10  and the second pair of wheels  30  are spaced apart in a parallel side by side relationship and are connected to one another by a transverse axle  12  and a second transverse axle  32 , respectively. 
     The second wheel assembly  28  is connected to the wheel assembly  8  by a pair of longitudinal members  34 . One end of each of the pairs of longitudinal members  34  is rotatably connected to the transverse axle  12 , while an opposite end of each of the pairs of longitudinal members  34  is rotatably connected to the second transverse axle  32 . Wheel assembly  8  in combination with a second wheel assembly  28  is particularly useful in heavy load applications or applications in which the work piece may be awkwardly sized and requires the additional stability provided by wheel assembly  8  in combination with a second wheel assembly  28 . 
     Drive means  18 , also called a dog or a pusher, of conveyor chain  20  is positioned in the inverted conveyor track  2  to engage the wheel assembly  8  in combination with the second wheel assembly  28  and to move the wheel assemblies  8  and  28  in a desired direction. As shown in FIG. 12, the drive means  18  is a vertically oriented elongate planar shaped member  60 . Member  60  is fixed at one end to the conveyor chain  20  and at its opposite end member  60  has notches  38 . The notches  38  are on both sides of member  60  for engaging the transverse axle  12  of wheel assembly  8  in combination with the second transverse axle  32  of second wheel assembly  28 , which permits travel in a forward or backward direction. Drive means  18  functions in a similar manner when only wheel assembly  8  is used, as shown in FIG.  3 . Chain  20  is any standard commercially available conveyor chain having both vertical  62  and lateral  64  load carrying wheels. A top plan view of the conveyor system accessory of FIG. 3 is shown in FIG.  4 . 
     Carrying means  14  is rotatably attached to wheel assembly  8  as shown in FIG.  3 . Alternatively, carrying means  14  is rotatably connected to longitudinal member  34 , which connects wheel assembly  8  to the second wheel assembly  28 , as shown in FIG.  1 . The carrying means or load pendant  14  must either swivel or rotate so that it remains vertically oriented as the travel pitch of the wheel assembly changes from 0° pitch to 90° pitch. As is known in the art, depending on the use of the inverted continuous conveyor track of the present invention, the carrying means or load pendant  14  may be situated so that the work piece is positioned either internally or externally to the conveyor track. 
     Several types of carrying means or load pendants  14  are commercially available from the manufacturers mentioned above. The type of load pendant used will depend on the applications in which the conveyor system is used. For example, depending on the application, a standard clevis load pendant may be appropriate. Other load pendants which may be useful in the present invention include a rigid “V” pendant, a double suspension load hook, a suspension indexing load hook and a double suspension rotating star pendant, to name a few. 
     Loading means  4  is shown in FIGS. 1,  3 ,  5 , and  8 . Loading means  4  positions the wheel assembly  8  either alone or in combination with the second wheel assembly  28  on the top surface or rail  16  of inverted continuous conveyor track  2 . Angle iron or guide  26  may also be present to facilitate the loading of wheel assemblies  8  and  28 . Rising or dipping ramps, which utilize the flow of gravity are used for loading means  4  and unloading means  6 . Alternatively, manual power ramps may transport the wheel assemblies on to and off of the inverted continuous conveyor track  2 . As shown in FIG. 11, unloading means  6  is a downward slopping exit ramp. Unloading means  6  has a slot or cut out, not shown, to facilitate the downward motion and disengagement of drive means  18 . Preferably, the loading means  4  and the unloading means or exit means  6  are placed in a run of straight track. 
     Turning now to FIGS. 13 and 14 the alignment means  22  of the present invention will be described in more detail. As shown in FIG. 13, alignment means  22  secures the wheel assembly  8  or the combination of wheel assembly  8  and second wheel assembly  28  on the top surface or rail  16  of the inverted continuous conveyor track  2 . In an embodiment in which wheel assembly  8  is used to carry a work piece alignment means  22  is a plate  36  that is fixedly attached to each of the wheels of the pair of wheels  10  of wheel assembly  8 . Plate  36  is located on an external surface of each of the wheels and is perpendicular to transverse axle  12 . Plate  36  extends beyond each wheel and overlaps a portion of both sides of the inverted continuous conveyor track  2 . Accordingly, plate  36  forms a boundary, which maintains wheel assembly  8  on the top surface  16  of the inverted conveyor track  2 . 
     In an alternative embodiment in which the wheel assembly  8  is used in combination with second wheel assembly  28 , plate  36  is fixedly attached to each of the wheels of the pairs of wheels  10  and  30  of the combination of wheel assembly  8  and second wheel assembly  28 . Again, plate  36  is situated on an external surface of each of the wheels. Plate  36  is perpendicular to the respective transverse axles  12  and  32  and extends beyond each wheel. Further, plate  36  overlaps a portion of both sides of the inverted continuous conveyor track  2  and forms a boundary for retaining the combination of wheel assembly  8  and second wheel assembly  28  securely on the top surface  16  of the inverted conveyor track  2 . 
     FIG. 13 also shows guide  24 , which may be used in conjunction with alignment means  22 . Guide  24  may be an angle iron, channel iron or tubing retainer to ensure that the wheel assemblies or trolleys stay in position between two dogs  60 , as shown in FIG.  12 . 
     A further embodiment of the present invention, denoted as a whole by reference numeral  200 , is shown in FIGS. 8-10. As shown in FIG. 9, wheel assembly  40  is designed to intermesh with conveyor chain  20 . In particular, wheel assembly  40  defines an inverted V-shaped assembly  42 . The inverted V-shaped assembly  42  has a transverse member  44  across an apex of the V-shaped assembly  42 . Transverse member  44  has rollers  46  on either side of the apex for rolling on a loading means or ramp  4  and unloading means or ramp  6 . The inverted V-shaped assembly  42  is attached to a housing  48 . Housing  48  has a pair of wheels  70  at its front end and a pair of wheels  72  at its rear end. Each of the pair of wheels  70  and  72  are spaced apart in a parallel side by side relationship and connected to the housing  48 . Housing  48  has a cut out or slot  50  to accommodate drive means  18 . Drive means  18  is positioned on the conveyor chain to engage slot  50  of the housing  48  of wheel assembly  40 . Carrying means  14  extends from transverse member  44 . 
     As shown in FIG. 8, rail  16  has been cut away to facilitate the intermeshing of wheel assembly  40  with conveyor chain  20 . A standard conveyor chain  20  has a normal center line of eight (8) inches. It is within the skill of the art to make adjustments in the center line of the conveyor chain  20 . It has been found that the distance or center line between the links of conveyor chain  20  can be increased to ten (10) inch centers to accommodate meshing wheel assembly  40 . An end view of this embodiment is shown FIG.  10 . 
     Housing  48  is an inverted U-shaped assembly having a cut out portion  50  for engagement of the drive means  18 . Housing  48  permits the respective pairs of wheels  70  and  72  to straddle a drive portion of the drive means  18  and intermesh with conveyor chain  20 . 
     A further embodiment of the present invention, denoted as a whole as reference numeral  300 , is shown in FIGS. 12 and 12 a  - 12   c . In this embodiment, wheel assembly  52  rides on the top surface  16  of the inverted continuous conveyor track  2 . Wheel assembly  52  has a pair of V-shaped rollers  54 , which are spaced apart and aligned to engage the upper most corners  16  of conveyor track  2 . The pair of V-shaped rollers  54  are fixedly attached to a V-shaped angle member  56  by a transverse axle  58 . The drive means  18  engages the V-shaped angle member  56  to move wheel assembly  52  is a desired direction. Carrying means  14  is rotatably attached to wheel assembly  52 . Loading means  4  and unloading means  6  are also used in conjunction with wheel assembly  52 . Further, drive means  18  engages the V-shaped angle member  56  of wheel assembly  52 . 
     Thus, while there has been described what are presently believed to be the preferred embodiments of the invention, those skilled in the art will understand that other and further modifications can be made without departing from the spirit of the invention. It is intended that the present invention includes all such modifications as come within the true scope of the invention as set forth in the claims.