Patent Publication Number: US-2004050667-A1

Title: Oven and proofing chain

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
     [0001] This application claims the priority benefit of U.S. Provisional Patent Application No. 60/396,601 filed on Jul. 18, 2002. 
    
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
       [0002] Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0003] Oven and proofing chains are used to convey dough through a proofing apparatus which causes the dough to rise and/or through an oven which bakes the dough. A typical proofing or oven chain comprises a plurality of links forming a continuous chain which is pulled through a substantially closed guide track. Each link includes a pair of plates connected to block links. A horizontal roller interposed between the plates engage side walls of the track to guide the link inside the track. Vertical rollers rotatably mounted to the block links support the chain in the track. The vertical rollers are permanently fixed to the block link using rivets and the like.  
       [0004] The environment in both the proofing apparatus and oven can cause the rollers to fail. When a vertical roller fails it must be replaced which requires disassembling the chain, and replacing the entire block link on which the failed roller is permanently affixed. The replaced block link is then discarded along with the rollers attached thereto. This is extremely time consuming and wasteful since the block link is typically undamaged, and if two rollers are fixed to the block link, the roller that has not failed is also discarded.  
       [0005] The vertical track through which the chain is pulled includes a longitudinal slot formed in the track top. Debris falls into the track through the slot, and collects in the track until the chain is shut down for cleaning. Shutting down the conveyor system to clean out the track and prevent damage to the chain is expensive.  
       SUMMARY OF THE INVENTION  
       [0006] The present invention provides a conveyor chain link including a block link and at least one longitudinal plate. The plate has one end pivotally fixed to the block link and a second end pivotally linkable to a block link of an adjacent conveyor chain link. At least one vertical roller is detachably fixed to the block link for supporting the link in a track. In one embodiment, the chain link includes a sweeper extending from the at least one plate, wherein the sweeper urges debris along the track as the link passes through the track.  
       [0007] A general objective of the present invention to reduce the downtime required to replace a failed vertical roller. This objective is accomplished by providing a conveyor chain link for the conveyor chain which has easily replaceable vertical rollers.  
       [0008] Another objective of the present invention is to reduce the downtime necessary to clean the track of a conveyor system. This objective is accomplished by providing a sweeper on a conveyor chain link which sweeps debris from the track to reduce the time necessary for cleaning the track.  
       [0009] These and still other objectives and advantages of the present invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described in reference to the accompanying drawings. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010]FIG. 1 is a top view of conveyor chain incorporating the present invention;  
     [0011]FIG. 2 is a side view of the conveyor chain of FIG. 1;  
     [0012]FIG. 3 is an end view of the conveyor chain of FIG. 1;  
     [0013]FIG. 4 is a cross sectional view of a vertical roller of FIG. 1;  
     [0014]FIG. 5 is an axial view of the vertical roller of FIG. 4;  
     [0015]FIG. 6 is a perspective view of the conveyor chain of FIG. 1; and  
     [0016]FIG. 7 is an alternative vertical roller incorporating the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0017] As shown in FIGS.  1 - 3 , a conveyor system for conveying products through a proofer and/or oven includes a conveyor chain  10  formed from a plurality of substantially identical links  12 . Each link  12  of the conveyor chain  10  is pivotally fixed to an adjacent link  20  to form an endless chain  10 . The chain  10  passes through an elongated guide track  14  having an elongated slot  16 . Product supports  18  fixed to each link  12  supports the product above the guide track  14  as the chain  10  conveys the product through an oven, proofer, and the like.  
     [0018] Referring to FIGS. 3 and 6, the guide track  14  defines the path of the product conveyed by the chain  10 , and includes vertically extending sides  100  joined by a substantially planar bottom  104 . Two top pieces  130  extending inwardly toward each other from a top edge of each opposing side  100  define the elongated slot  16 . The chain links  12 ,  20  forming the chain  10  pass through the space defined by the top pieces  130 , sides  100 , and bottom  104  which guide the chain  10  along the path.  
     [0019] Referring now to FIGS.  1 - 3 , in a preferred embodiment, each link  12  forming part of the chain  10  includes a block link  22  which is pivotally fixed to a pair of vertically spaced, parallel, longitudinal plates  24 ,  26 . Each plate  24 ,  26  has one end  28 ,  30  pivotally fixed to the block link  22  and a second end  32 ,  34  pivotally fixed to a block link  36  of the adjacent link  20 . A horizontal roller  38  is mounted between the two plates  24 ,  26  to keep the conveyor chain  10  centered within the spaced defined by the track  14 . Vertical rollers  40 ,  42  detachably fixed to the block link  22  engage the track bottom  104  to support the link  12  in the track  14 .  
     [0020] The block link  22  includes a body  46  having opposing ends  48 ,  50  joined by sides  52 . A vertical bore  56  formed in one end  50  of the block link body  46  receives a pin  76  for pivotally connecting the plates  24 ,  26  thereto. A second vertical bore  54  is formed in the opposing end  48  of the block link body  46  for pivotally connecting the plates of the link adjacent the opposing end  48  of the block link body  46 .  
     [0021] A transverse horizontal bore  90  formed through the block link body  46  receives a threaded stud  92  (shown best in FIG. 4) extending from each vertical roller  40 ,  42  to detachably fix each vertical roller  40 ,  42  to the block link  22 . The bore  90  can be threaded to threadably engage the stud  92 . Preferably, a locking insert, such as available from Fairchild Fasteners of Dulles, Va., is inserted into each end of the bore  90 . The locking insert threadably engages the stud  92 , and inhibits inadvertent disengagement of the stud  92  from the insert due to vibrations.  
     [0022] The elongated plates  24 ,  26  extend between, and link, the two block links  22 ,  36 . Although a pair of plates  24 ,  26  is disclosed, the link  12  can include one or more plates without departing from the scope of the invention. Each plate  24 ,  26  is connected to the block link  22  by aligning the vertical bore  56  with one of holes  58 ,  60  formed in one end  28 ,  30  of each plate  24 ,  26 . Holes  62 ,  64  formed in the opposing end  32 ,  34  of the plates  24 ,  26  are aligned with the vertical bore  54 , formed in the opposing end  48  of the adjacent block link  36 .  
     [0023] The pivot pin  76  having a head  80  formed at one end  86  includes an opposing end  88  inserted through the bore  56  and respectively aligned holes  58 ,  60 . The pivot pin  76  pivotally links the plates  24 ,  26  to the block link  22 , and is retained in the bore  56  by a cotter pin  82 . The cotter pin  82  is inserted through a hole  84  in the opposing pin end  88  to prevents the pivot pin  76  from slipping out of the bore  56 . A second pivot pin  78  substantially identical to the first pin  76  is inserted through the bore  54  of the adjacent block link  36  and the holes  62 ,  64  to pivotally connect the opposing ends  32 ,  34  of the plates  24 ,  26  to the adjacent link block link  36 . The plates  72 ,  74  of the adjacent link  20  are then pivotally connected to the adjacent block link  36 , in the same manner as described for the one end of the plates  24 ,  26  connected to the block link  22 .  
     [0024] The horizontal roller  38  is mounted between the plates  24 ,  26 , and freely rotates about a vertical shaft  94 . The vertical shaft  94  extends through holes  96 ,  98  formed in the plates  24 ,  26 , and intermittently engages the sides  100  of the track  14  as the link moves through the track  14 . The roller  38  has a diameter which is greater than the width of the plates  24 ,  26 , such that the roller  38  extends transversely past the plates  24 ,  26 . Although a single horizontal roller  38  interposed between the pair of plates  24 ,  26  is disclosed, more than one roller interposed between the pair of plates can be provided without departing from the scope of the invention.  
     [0025] The substantially identical vertical rollers  40 ,  42  are detachably fixed to the block link  22 , and support the weight of the conveyor chain  10  and product being conveyed. Although a pair of vertical rollers is disclosed, a single vertical roller fixed to the block link can be used without departing from the scope of the invention. Advantageously, the vertical rollers  40 ,  42  are detachably fixed to the block link  22  to allow replacement of the vertical rollers  40 ,  42  without disassembling the block link  22  from the plates  24 ,  26 . Moreover, when one vertical roller fails, only the failed roller need be replaced.  
     [0026] The vertical rollers  40 ,  42  are substantially identical. Therefore, only one vertical roller  40  will be described with the understanding that the description also applies to the other vertical roller  42 . Referring to FIGS. 4 and 5, the vertical roller  40  include an outer race  102  which engages a track bottom  104  and an inner race  106 . Ball bearings  108  interposed between the inner and outer races  106 ,  102  allow the outer race  102  to revolve about a roller axis  110  while the inner race  106  is fixed relative to the block link  22 . The size and number of ball bearings  108  is dependent on the desired size of the roller and load capacity of the chain link.  
     [0027] The outer race  102  includes a radially outwardly facing surface  112  which engages the track bottom  104 . The radially outwardly facing surface  112  is joined to a radially inwardly facing surface  114  by sidewalls  116 . A radially inwardly opening groove  118  is formed in the radially inwardly facing surface  114  of the outer race  102 . The inner race  106  is disc shaped having opposed axially facing sides  120 ,  122 . A radially outwardly facing circumferential groove  124  formed in the inner race  106  between the inner race sides  120 ,  122  opens radially outwardly toward the inwardly opening groove  118  formed in the outer race  102 . The grooves  118 ,  124  cooperatively capture the ball bearings  108  therebetween.  
     [0028] The axially extending stud  92  extends from one side  120  of the inner race  106  coaxial with the roller axis  110 . The one side  120  faces inwardly toward the block link  22 . Preferably, the stud  92  includes external threads to threadably engage the locking insert, or internal threads, in the bore  90  to detachably fix the vertical roller  40  to the block link  22 . Advantageously, detachably fixing the vertical roller  40  to the block link  22  allows detaching the roller  40  from the block link  22  if the roller  40  requires replacement. The stud  92  can be formed as an integral part of the inner race  106  or fixed to the inner race  106  using methods known in the art, such as welding, crimping, threadably engaging, and the like, without departing from the scope of the invention. Moreover, although threadably engaging the stud with the block link to detachably fix the roller to block link is preferred, other methods for detachably fixing the roller to the block link, such as described below and shown in FIG. 7, pinning the stud to the block, and the like, can be used without departing from the scope of the invention.  
     [0029] A recessed hex socket  123  fixed relative to the stud  92  extends through the other, or outwardly facing, side  126  of the inner race  106 . The socket  123  is coaxial with the roller axis  110 , and is engageable by a socket wrench for rotating the stud  92  to threadably engage the stud  92  with the block link  22  and fix the roller  40  to the block link  22 . Although a hex socket is preferred, any engagement structure, such as a slot, Phillips head, and the like, which can be engaged to rotate the stud in the link lock bore can be used without departing from the scope of the invention. Preferably, the engagement structure is recessed to prevent dirt from accumulating on surfaces of the outwardly facing inner race side. Most preferably, the engagement structure is formed in a body  125  including the stud  92 , as shown in FIG. 4.  
     [0030] The product support  18  is supported above the link  10  by the link upper plate  24 , and is fixed to the link  12  by the horizontal roller vertical shaft  94 . Preferably, an upper end of the shaft  94  includes threads for threadably engaging a nut which secures the product support  18  to the link  12 . A grid or other platform (not shown) can be secured to the product support  18  to provide a large surface for carrying the product.  
     [0031] A sweeper  128  mounted to the link  12  extends radially from the plates  24 ,  26  to engage debris, such as seeds and flour, and other material in the space defined by the track  14 . In the embodiment disclosed herein, the sweeper  128  loosely surrounds the pair of plates  24 ,  26  and conforms to the inside shape of the track  14  to sweep debris through the track  14 . Although, the sweeper  128  disclosed herein is allowed to slide along the plates  24 ,  26 , the sweeper  128  can be fixed relative to the link  12  using methods known in the art, such as a bracket, fasteners, adhesives, and the like without departing from the present invention. In addition, the sweeper  128 , can be shaped to sweep only the track bottom  104  or sides  100  without departing from the scope of the invention.  
     [0032] The sweeper  128  can be formed from any suitable material which depends on the intended use of the chain link  12 . For example, if the link  12  is used in a proofer, a plastic material, such as an ultra high molecular weight (UHMW) plastic can be used. However, if the chain  10  will be exposed to high heat, such as in an oven, a sweeper formed from a metal, such as stainless steel, or other material having a high melting point, is preferred.  
     [0033] A stop plate  142  can be provided which abuts the sweeper  128 . The stop plate is substantially vertical, and squares the sweeper relative to the track to maintain the sweeper in a substantially vertical position. The stop plate  142  includes a tab  144  which is sandwiched between the product support  18  and top plate  24  to clamp the stop plate  142  to the link  12 . Although a stop plate is disclosed, a stop plate is not necessary for practicing the invention.  
     [0034] As shown in FIGS. 3 and 6, the track  14  includes the bottom  104 , the two sides  100 , and two top pieces  130  which define the inside shape of the track. The horizontal roller vertical shaft  94  and product support  18  extend upwardly through the longitudinal slot  16  defined between the two top pieces  130 . The horizontal roller  38  engages the track sides  100  to guide the link  12  through the track  14 , and the vertical rollers  40 ,  42  engage the track bottom  104  to support the link  12  in the track  14 . Although the track inside shape is defined as being substantially square, the track  14  can have any inside shape without departing from the scope of the invention.  
     [0035] In an alternative embodiment shown in FIG. 7, a vertical roller  132  includes a countersunk bore  134  formed through an inner race  136 . A bolt (not shown) having a threaded portion extends through the bore  134 , and threadably engages the block link  22 , extends completely through the bore  134  to threadably engage a nut, extends completely through the bore  134  to receive a pin, and the like, to detachably fix the roller  132  to the block link  22 . As shown in FIG. 7, more than one row of ball bearings  138  can be provided between the inner and outer races  136 ,  140  to reduce the roller diameter while increasing the load bearing capacity of the roller  132 .  
     [0036] While there has been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. For example, although the pair of plates  24 ,  26  of the link  12  are shown as being disposed inside the track  14 , one of the plates  24  can be positioned above the longitudinal slot  16 , as is known in the art. Of course, if one of the plates  24 ,  26  is disposed above the track  14 , the sweeper  128  does not necessarily surround both plates  24 ,  26 , but would only be mounted relative to the plate  26  disposed within the track  14 .