Abstract:
A bolt diversion system for use with a conveyor system having a conveyor chain for towing a movable cart. The bolt diversion system is used to prevent debris from interfering with operation of the conveyor chain. The bolt diversion system includes first and second rails, disposed vertically and spaced from one another so as to define a slot therebetween. Lower faces of the rails are disposed close to and in overlapping relationship to upper lateral edges of the chain so as to define a small gap between the first and second rails and the conveyor chain that is smaller than the debris, so that the debris remains in the slot and on top of the conveyor chain. The debris is conveyed by the conveyor chain to a debris removal zone in which a wiper arm assembly is provided. The wiper arm assembly includes a wiper arm that extends across a top of the conveyor chain. The wiper arm knocks debris off of the conveyor chain and into a debris collection container.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention is generally directed toward conveyor systems and, more particularly, toward tow conveyor systems incorporating devices for preventing debris from interfering with the conveyor operation. 
   2. Description of Related Art 
   A tow conveyor system includes a chain having a number of chain links joined together end-to-end to form a continuous or endless chain that is received in a track. The links are typically joined so as to allow a degree of pivotal motion to accommodate bends in the track. 
   As shown in  FIG. 8 , a prior art conveyor chain  10  is received within a recessed track or channel  12 , formed by a metal structural member  14  that is disposed under a factory floor  16 . The conveyor chain  10  is configured to receive a kingpin  18  extending downwardly from a mobile carrier or cart (not shown) that is pulled by the chain  10  past one or more workstations. 
   Conveyor systems are often used in manufacturing facilities, where various components of a manufactured article are assembled at each work station. Such assembly may use various fasteners, including threaded members such as bolts. Often, bolts  20  and other such debris are dropped and end up on the floor. This debris can find its way into the recessed channel  12  housing the conveyor chain  10 . In some circumstances, the debris becomes wedged between the chain  10  and the side of the channel  12 , causing the chain  10  to have an uneven or jerking motion. Sometimes, the debris jams the chain  10 , breaking one or more shear pins on the main gear box drive, and requiring the conveyor to be shut down until necessary repairs can be made. 
   In response to this problem, it has been proposed, as shown in  FIG. 8 , to provide a pair of horizontal plates  22  that are disposed over the top of the channel  12  and have side surfaces that face each other at a fixed distance, so as to define a slotted aperture  24  over the top of the channel  12 . A series of semi-rigid brushes  26  project inwardly from beneath the side surfaces and extend toward each other. In this way, it was expected that the brushes  26  would prevent bolts  20  and other debris from entering the slotted aperture  24  and interfering with the chain  10 , while still allowing the kingpin  18  to move through the slotted aperture  24 . 
   However, it has been found that the brushes  26  are ineffective at preventing debris from entering the channel  12 . It is believed that the brushes  26  deform over time as a result of repeated engagement with the kingpins  18 , causing a gap to develop between the brushes  26  that allows debris to fall into the channel  12 . Further, since the brushes  26  are disposed below the floor surface, it is believed that once debris is received by the brushes  26 , it is difficult for the debris to escape except for passing through the brushes  26  into the channel  12 . It is also believed that the brushes  26  lack strength to hold certain types of debris, and that the kingpin  18  may actually force the debris past the brushes  26 . In any event, the brushes  26  require frequent maintenance and replacement in order to maintain their effectiveness, and conveyor downtime remains a problem despite this proposed remedy. Accordingly, there exists a need in the art for a structure that prevents debris from interfering with conveyor operation. 
   SUMMARY OF THE INVENTION 
   The present invention is directed toward correcting difficulties and drawbacks associated with known systems by providing a conveyor system incorporating a bolt diversion system that prevents debris from interfering with conveyor operation. 
   In accordance with the present invention, the bolt diversion system includes first and second rails that extend vertically and are spaced from one another so as to define a slot therebetween. The rails are mounted at a location proximate to, but above, the conveyor chain in a position overlapping lateral edges of the conveyor chain and, as such, a small gap is provided between the first and second rails and the conveyor chain that is smaller than the debris that may interfere with conveyor operation. Accordingly, debris entering the slot remains on top of the chain and is conveyed thereby to a debris removal zone. 
   In further accordance with the present invention, a wiper assembly is provided at the debris removal zone to remove debris being carried on top of the conveyor chain. The wiper arm assembly includes a wiper arm that extends across the conveyor chain so as to be adjacent the top surface of the conveyor chain. The wiper arm directs debris being carried on the conveyor chain into a collection receptacle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and further features of the present invention will be apparent with reference to the following description and drawings, wherein: 
       FIG. 1  is a schematic illustration of a conveyor system incorporating the bolt diversion system according to the present invention; 
       FIG. 2  is a top view illustrating a debris removal zone according to present invention; 
       FIG. 3  is a cross-sectional view as seen along line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is a cross-sectional view as seen along line  4 - 4  of  FIG. 2 , 
       FIGS. 5A ,  5 B and  5 C illustrate the debris removal zone according to the present invention, and show wiper assemblies according to the present invention in various states of use; 
       FIG. 6  is a perspective view of the wiper assembly according to the present invention; 
       FIG. 7  is an end elevational view of the wiper assembly; and, 
       FIG. 8  shows a conveyor track of the type used in a conventional conveyor, along with a prior art device for blocking debris. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   With reference to  FIG. 1 , a conveyor system  50  incorporating a bolt diversion system of the present invention is illustrated. The present conveyor system  50  includes a loading/unloading station  52  and a plurality of debris removal zones  54 . The loading/unloading station  52  is adapted for placing one or more movable articles, preferably mobile carriers or carts, on the conveyor at the start of the conveyor cycle, and for removing the mobile carriers at the end of the conveyor cycle. In the preferred and illustrated embodiment, the conveyor system  50  is a tow conveyor system including a conveyor chain  60  for pulling the mobile cart along the conveyor path and past one or more workstations. It will be appreciated that the circular configuration of the conveyor system is only one example, and that the present invention is not limited thereto. 
   As particularly shown in  FIG. 2 , the conveyor chain  60  is formed of a plurality of links  60   a  that are pivotally connected to each in a known fashion so as to enable the chain  60  to follow curves at the corners of the conveyor system  50 . Each link  60   a  includes an upper surface  60   b , a pair of lateral side surfaces  60   c , and a bottom surface  60   d . The upper surfaces  60   b  of the links  60   a  cooperate to define an upper surface of the chain  60 . Lateral portions of the chain upper surface  60   b  (i.e., portions adjacent the side surfaces  60   c ) are hereinafter referred to as the lateral edges of the upper surface  60   b . Further, each link includes an engagement portion or opening  60   e  for receiving a kingpin  68  of an associated mobile cart  68   b , as will be described hereinbelow. 
   The chain  60  is received within a guide assembly that follows and defines the conveyor path. The guide assembly includes a guide  64  and a pair of cap plates  70 . It will be appreciated that the guide  64  is substantially symmetrical about a central axis and that the cap plates  70  are substantially identical to one another. 
   The guide  64  is preferably disposed below a floor surface  66 , and defines a recessed channel  62 . The guide  64  includes a pair of inner vertical walls  64   a , a bottom wall  64   b , a pair of top walls  64   c , and a pair of outer vertical walls  64   d , as shown best in  FIG. 3 . Each of the cap plates  70  are associated with one of the guide top walls  64   c , and are set into the floor so as to be flush with the floor surface  66 . The cap plates  70  are supported by the associated top wall  64   c  so as to cover an associated lateral portion of the channel  62 , as illustrated in  FIG. 3 . 
   Each of the cap plates  70  have an inwardly directed side surface  70   a  that faces toward the other cap plate side surface  70   a . The cap plate side surfaces  70   a  cooperate to define a slot  72  over the top of the channel  62 . The slot  72  has a reduced width as compared to that of the channel  62  and, with the exception of debris removal zones  54 , preferably extends uninterrupted the length of the conveyor system  50 . 
   The present bolt diversion system includes first and second rails  74  and a wiper assembly  80  that cooperate to retain debris on the top of the conveyor chain  60  and, when the debris reaches one of the debris removal zones  54 , to remove the debris from the top of the chain  60  into a collection receptacle  90 . 
   The first and second rails  74  are generally rectangular in shape and have inwardly facing side surfaces  74   a  and downwardly facing bottom surfaces  74   b . The rails  74  are secured to, and extend downwardly from, an underside of an associated one of the cap plates  70  adjacent the side surfaces  70   a  thereof. As such, the rail inner surfaces  74   a  are substantially flush with the side surfaces  70   a  of the associated cap plate  70 , and face toward one another so as to further define the slot  72  and extend a depth dimension of the slot  72 . 
   The rail bottom surfaces  74   b  face toward, and are slightly spaced from, the upper surface  60   b  of the conveyor chain  60 . More specifically, the downwardly-facing rail bottom surfaces  74   b  overlap lateral edges of the chain upper surface  60   b , as illustrated. Accordingly, a small gap  76 , which is sized to prevent entry of debris therethrough that would cause jamming of the conveyor chain  60  or otherwise interfere with operation of the conveyor, is provided between the rail bottom surface  74   b  and the chain upper surface  60   b . Therefore, potentially damaging debris is retained on the chain upper surface  60   b  within the slot  72  between the rails  74  and is conveyed with the chain  60  to the next debris removal zone  54 , described hereinafter. 
   In the preferred embodiment, the first and second rails  74  are formed of a low friction polymer material, such as nylon. It is contemplated that the rails  74  can be installed with new conveyor cap plates  70  or retrofitted onto the cap plates in existing conveyor systems. The rails  74  are preferably secured to the associated cap plate  70  by mechanical fasteners extending through the cap plates  70  from above. Although the rails  74  are preferably spaced from the chain upper surface  60   b , it is also contemplated that the rail bottom surface  74   b  may slidably engage the chain upper surface  60   b , either continuously or intermittently, if desired. 
   With reference to  FIGS. 1 ,  2 ,  4 - 7 , the wiper assembly  80  includes a wiper arm assembly  82 , a stop assembly  104 , a main body  106 , a lower mounting plate  108 , and the collection receptacle  90 . Preferably, a pair of oppositely-directed wiper assemblies  80  is provided at each debris removal zone  54 , as will be apparent from the following description and is shown in  FIG. 1 . In the debris removal zone, the rails  74 , a portion of the floor surface  66 , and portions of the guide  64  are removed, and the wiper assembly  80  is mounted on an underside of the guide top wall  64   c . The portion of the floor surface  66  is removed, as shown best in  FIG. 4 , to permit access to the collection receptacle  90  from above. Naturally, a removable cover (no shown) may be installed to normally close or cover the receptacle opening. Preferably, a plurality of threaded fasteners  109  extend through the guide top wall  64   c  and are threadably received in corresponding openings  102  in the main body  106  to mount the wiper assembly  80  in place. 
   The main body  106  includes a flat base plate  106   a  that is secured to the underside of the guide top wall  64   c , and a downwardly extending mounting block  106   b  to which the lower mounting plate  106  and stop assembly  104  are secured. 
   The lower mounting plate  108  is a flat plate that is secured to a downwardly facing surface of the mounting block  106   b  via a series of bolts  110 . The lower mounting plate  108  cooperates with the flat base plate  106   a  of the main body  106  and a first hinge pin  96  to pivotally mount the wiper arm assembly  82 , described hereinafter. 
   The stop assembly  104  includes a stud  104   a  that is threadably received in a horizontal bore formed in the mounting block  106   b  and from which a stop member  104   b  extends. A lock nut holds the stud  104   a  in place. The extension amount of the stop member  104   b  is adjustable so as to vary a position in which the stop member  104   b  engages a rigid arm  84  of the wiper arm assembly  82 , and thereby serves to limit a range of movement of the wiper arm assembly  82  in a first direction, as will be apparent from the following description. 
   The wiper arm assembly  82  includes a wiper arm  86 , the rigid arm  84 , a first biasing spring  88 , a second biasing spring  92 , and a fixed mount  94  for the second biasing spring  92 . 
   The rigid arm  84  includes a first portion  84   a , a second portion  84   b , and a cylindrical portion  84   c  disposed between and interconnecting the first and second portions  84   a ,  84   b . The cylindrical portion  84   c  is disposed between the lower mounting plate  108  and the base plate  106   a  of the main body portion  106  and receives the first hinge pin  96  to secure the rigid arm  84 , and the wiper arm  86  associated therewith, for pivotal motion. In this regard the cylindrical portion  84   c  may be considered as a bearing or bushing that rotates around the first hinge pin  96 . 
   The first portion  84   a  of the rigid arm  84  extends from an upper end of the cylindrical portion  84   c  and has a finger  84   d  extending from a distal end thereof. The finger  84   d  serves as a stop for the wiper arm  86  and as a mount for the first biasing spring  88 , as described more fully hereinafter. 
   More specifically, the distal end of the rigid arm first portion  84   a  is bifurcated so as to define upper and lower spaced apart mounts, each of which have an aligned opening formed therein for receipt of a second hinge pin  98 . The wiper arm  86  has a proximal end, including an extension  86   a  that fits between the upper and lower mounts. The extension  86   a  has an opening formed therein through which the second hinge pin  98  extends to pivotally secure the wiper arm  86  to the rigid arm first portion  84   a.    
   The finger  84   d  extends from the distal end of the rigid arm first portion  84   a  and along a first side  86   b  of the wiper arm  86  at the proximal end thereof. A first end of the first biasing spring  88  is secured to the finger  84   d  while the second end of the first biasing spring  88  is secured to a distal end of the wiper arm  86 . Preferably, the first side  86   b  of the wiper arm  86  has a lengthwise extending groove formed therein to receive at least a portion of the first biasing spring  88 . The first biasing spring  88  urges the wiper arm  86  into a position wherein the first side  86   b  of the wiper arm proximal end is in engagement with the rigid arm finger  84   d , and in which the wiper arm  86  is substantially aligned with the rigid arm first portion  84   a , as illustrated. 
   The rigid arm second portion  84   b  extends from a lower end of the cylindrical portion  84   c , and extends across a downwardly facing surface of the main body  106 . A first end of the second biasing spring  92  is secured to a distal end of the rigid arm second portion  84   b , while a second end of the second biasing spring  92  is secured to the fixed mount  94 , which is welded to or otherwise integrally provided by the main body portion  106 . The second biasing spring  92  urges the rigid arm second portion  84   b  into engagement with the stop member  104   b , as illustrated. 
   The collection receptacle  90  is disposed in a position to collect debris that is brushed or knocked off of the chain  60  by the wiper arm  86 , as is shown in  FIG. 4 . More particularly, the receptacle  90  includes an inlet ramp  90   a  and a bin  90   b . The ramp  90   a  is disposed adjacent one lateral side surface  60   c  of the chain  60  and leads downwardly to the bin  90   b . Debris moved off of the chain upper surface  60   a  by the wiper arm  86  falls down along the inlet ramp  90   a  into the bin  90   b  and collects therein. 
   With reference to  FIGS. 5A-5C , operation of the wiper assemblies  80  at a debris removal zone  54  will be described hereinafter. 
     FIG. 5A  illustrates the wiper assemblies  80  when the conveyor  60  is operated in a first direction, and in a condition in which the wiper arm assemblies  82  are at rest. As such, the wiper arms  86  extend across the top  60   c  of the conveyor chain  60   a  (see  FIG. 4 ), and are biased toward the rest positions by operation of the springs  88 ,  92 . In this position, should a bolt or other debris engage the wiper arm  86 , the bolt or debris will be brushed or knocked off of the top of the conveyor  60  and into the collection receptacle  90 . It will be appreciated that the second spring  92  biasing the wiper arm assembly  82  into the rest position illustrated in  FIG. 5A  will have sufficient strength to retain the wiper arm assembly  82  in the rest position when debris is encountered, but will permit the wiper assembly  82  to pivot into a deflected or second position upon encountering a stronger or immovable obstacle, such as the kingpin  68 . 
   With reference to  FIG. 5B , the wiper assemblies  80  are illustrated in a condition in which one of the kingpins  68  engages the wiper arm  86 . As illustrated, the wiper arm assembly  82  is pivoted around the hinge pin  96  and against the biasing force of the second spring  92 , such that the rigid arm  84  moves outwardly and such that the wiper arm  86  rides over the kingpin  68 . When the kingpin  68  moves beyond the wiper arm  86 , the second spring  92  rotates the wiper arm assembly  82  back to the rest position by pulling the rigid arm  84  into contact with the stop member  104   b.    
   With reference to  FIG. 5C , the wiper assembly  80  is illustrated in a condition in which the conveyor  60  is operated in a second or opposite direction and in which the kingpin  68  engages the second side  86   b  of the wiper arm  86 . The wiper arm  86  is pivoted about the second hinge pin  98  against the biasing force of the first spring  88 . The wiper arm  86  rides over the kingpin  68 , and when the kingpin  68  has cleared the wiper arm  86 , the first spring  88  rotates the wiper arm  86  back into the rest position by pulling the wiper arm  86  into contact with the finger  84   d.    
   While the present invention has been described hereinbefore with particularity, it is considered apparent that the invention is capable of numerous modifications, rearrangements, and substitutions of parts and, therefore, is not limited to the particular preferred embodiment illustrated herein and described hereinbefore. Rather, the invention is only defined by the claims appended hereto.