Abstract:
A clamping guide including clamps, a clamp actuator and alignment guides where the alignment guides are coupled to and actuated with the clamps. In the preferred embodiment, a pair of clamps and alignment guides are positioned on opposite sides of a power conveyor so that a procession of product, such as blocks, passes between the clamps and between the alignment guides. Each alignment guide is coupled to a corresponding clamp with a linkage. The linkage is configured so that as the clamps close against a portion of the procession on the conveyor, the alignment guides engage another portion of the procession upstream from the clamps to align product between the guides. In another preferred embodiment, the linkage couples the alignment guides to the clamps so that when the clamps are partially or fully withdrawn from the procession, the alignment guides are closer to the procession than the clamps, thereby preventing product from contacting and twisting on edges of the clamps.

Description:
BACKGROUND  
         [0001]    The present invention relates to conveyors and more particularly to an alignment system for use with conveyors to align conveyed product.  
           [0002]    In certain material handling industries, it is desirable to convey a procession of products on a conveyor system, stop flow of the procession and perform some operation on individual units in the procession. For example, in the concrete block manufacturing industry, blocks are typically conveyed in procession on a conveyor to a patterning station, where individual blocks are turned relative to other blocks in the procession. This is usually done to prepare a group of blocks in the procession for staggered stacking in multi-tiered shipping stacks. Typically, one or more blocks, also referred to as “groups,” are separated from the upstream procession of blocks for turning.  
           [0003]    A clamp, positioned at the end of a conveyor but upstream from the patterning station, is used to perform this separation. After a group of blocks to be turned passes the clamp, the clamp clamps against the next blocks in the procession. The passed group of blocks continues to the patterning station, where they are turned. After turning, the clamp releases the clamped blocks and the process is repeated.  
           [0004]    Frequently on conveyor systems, mis-aligned blocks jam in a clamp because they cannot be squarely clamped. The blocks become twisted or mis-aligned due to collision with other blocks or conveyor vibration. To un-jam the clamp, an operator must manually remove or re-orient the block in the clamp, resulting in production down time. Furthermore, efforts to reorient the blocks in the clamp are potentially dangerous.  
         SUMMARY OF THE INVENTION  
         [0005]    The aforementioned problems are overcome in the present invention wherein a clamping guide is provided with a clamp and an alignment guide that are coupled to and actuated with each other. The clamp and alignment guide are configured so that as the clamp stops a conveyed procession of product, the alignment guide simultaneously aligns the procession upstream of the clamp.  
           [0006]    In the preferred embodiment, a pair of clamps are mounted across from one another on a conveyor that conveys a procession of blocks between the clamps. A drive ram extends and retracts the clamps against individual blocks on the conveyor to stop the upstream procession. A linkage couples each of the clamps to corresponding alignment guides positioned upstream from the clamps. The linkage is configured to actuate each of the guides with each of the clamps so that as the clamps extend to stop the procession, the guides align blocks upstream from the clamps.  
           [0007]    In a more preferred embodiment, the linkage couples the guides to the clamps so that as the clamps are retracted by the drive ram and fully withdrawn from the procession, the alignment guides remain closer to the procession than the clamps. Accordingly, the alignment guides protect edges of the clamps from the edges of passing blocks, thereby preventing corners of blocks snagging and twisting on the clamp edges.  
           [0008]    The present invention provides a simple and effective clamping guide to stop and simultaneously align a procession of product. The present invention preferably utilizes one drive system to extend and retract clamps and corresponding alignment guides, thereby eliminating the need for additional drive systems to operate each individually. Further, the retarded retraction of the alignment guides relative to the clamps allows the alignment guides to provide a secondary function of preventing clamp edges from snagging and turning passing product.  
           [0009]    These and other objects, advantages and features of the present invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiments and the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view showing the clamping guide of the present invention;  
         [0011]    [0011]FIG. 2 is a top plan view of the clamping guide;  
         [0012]    [0012]FIG. 3 is an enlarged top plan view of a linkage of the clamping guide in an extending position;  
         [0013]    [0013]FIG. 4 is an enlarged top plan view of the linkage in a retracting position; and  
         [0014]    [0014]FIG. 5 is a perspective view of the linkage. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    A clamping guide in accordance with a preferred embodiment of the present invention is shown in FIG. 1 and generally designated  10 . The clamping guide  10  generally includes a frame  12 , clamps  20 , alignment guides  30 , a linkage  40 , which couples the clamps  20  to corresponding alignment guides  30 , and actuators  50  for extending and retracting the clamps  20  toward and away from one another. By way of example, FIG. 1 also shows a power roller conveyor  100 , which is driven by a conventional roller conveyor drive  110 . The power roller conveyor  100  conveys a procession downstream in direction D through the clamping guide  10 . By way of further example, the clamping guide  10  is also shown upstream from patterning station  200 , which is shown in general detail. As will be appreciated, although a patterning station  200  is illustrated, the clamping guide  10  of the present invention is well suited for use with other product processing stations. In operation, the actuators  50  drive clamps  20  toward blocks in procession B until the clamps  20  clamp against one or more individual blocks. This prevents those clamped blocks from being conveyed or pushed downstream by upstream line pressure caused by blocks accumulating against the clamped blocks. As the clamps  20  are driven, the linkages  40  simultaneously actuate the alignment guides  30  to move toward the procession of blocks B with the corresponding clamps  20 . As the guides engage the procession of blocks B, the linkages allow the alignment guides to align blocks between the guides, thereby aligning the procession of blocks B immediately upstream from the clamps. Preferably, the guides  30  align, but do not clamp the blocks.  
         [0016]    Accordingly, when individual blocks in the procession B reach the clamping guide  20 , they are squarely aligned between the clamps so that they are not crushed by or mis-aligned within the clamps  20 . Preferably, when the clamps  20  are withdrawn by the actuator  50 , the corresponding alignment guides  30  are also withdrawn. When the clamps  20  are fully withdrawn, the alignment guides are positioned closer to procession B than the clamps  20 . In this configuration, the individual blocks in the procession B are unlikely to snag on edges of the clamps because the blocks are deflected from the clamps  20  by the alignment guides  30 .  
         [0017]    With reference to FIG. 1, the clamps  20 , clamping actuators  50  and alignment guides  30  are preferably mounted to frame  12 . The frame  12  generally includes base members  14 , which are connected to one another by transverse beams  15  located under the conveyor  100  and conveyor drive  110 . Alignment frame members  16  are mounted to the transverse beams  15 . Likewise, clamp frame members  18  are mounted to the transverse beams  15  near the clamps  20 .  
         [0018]    The configuration, size and location of the elements of the frame may vary from application to application depending on the desired configuration of the clamps  20  and clamping guides  30 . Power roller conveyor  100  and conveyor drive  110  also are mounted to the transverse beams. As will be appreciated, the clamping guides  10  of the present invention may be retrofitted over an existing conveyor system thereby eliminating the need for the conveyor  100  and associated drive  110 . Further, the power roller conveyor  100  may be substituted with a belt or other conventional conveyor system as the application requires.  
         [0019]    In the preferred embodiment shown in FIGS. 1 and 2, the clamps  20  are movable relative to the frame  12 . Preferably, the extender arms  25  are slidably interfit within the clamp slide members  19 . Similarly, the alignment guides  30  are moveable with respect to the frame  12 . More preferably, the alignment guides  30  are pivotally mounted with mounting pins  35  to the alignment guide slide members  17 . Optionally, the interfitting extender arm  25  and clamp slide members may be substituted with any conventional guiding system that allows the clamps  20  to move toward and away from the procession of blocks B, more preferably perpendicular to the procession&#39;s line of travel on the power conveyor  100 .  
         [0020]    The clamp slide members  19  are adjustably interfit within clamp frame members  18 . This configuration provides adjustability of the alignment guides to accommodate different sized product. A clamp width adjuster  70  is mounted to clamp frame members  18 . The adjuster  70  may be any screw, lasp, hook or other conventional mechanism capable of holding the clamp slide members  19  and clamp frame members  18  in fixed relation to one another, but when de-actuated, allow the clamps  20  to be moved closer to or away from the procession.  
         [0021]    The alignment slide members  17  may also be slidably interfit within alignment frame members  16 , and adjustable with actuation of alignment guide width adjusters  72 , which act on the same premise as the clamp width adjuster  70  explained above.  
         [0022]    The clamp actuators  50  are mounted in fixed relation to the frame  12 , preferably to the clamp frame members  18 . As illustrated, the clamp actuators are hydraulic cylinders  51  with rams  52  extendable and retractable therefrom in a conventional manner. As will be appreciated, the hydraulic cylinders may be replaced with any commercially available actuator system, such as a pneumatic drive, a gear drive, or other drive mechanism, capable of extending and retracting the clamps  20 . As the application requires, the actuator  50  may be controlled by a programmable logic control unit (not shown) to control the extension and retraction of the ram  52  and, therefore, movement of the clamps  20 .  
         [0023]    [0023]FIGS. 3 and 4 show the actuator  50  and clamps  20  in more detail. The yoke  53  of ram  52  is connected to the clamp  20  with drive arm  21  via yoke pin  59 . The clamp  20  is guided in its extension and retraction by interfitment of extender arm  25  in clamp slide member  19 . Each of the clamps  20  include a clamping plate  22  to which a wearing plate  23  is secured. The clamping plate  22  is preferably constructed of metal or synthetic material of high strength. The clamp wearing plate  23  preferably is constructed of a high density rubber or plastic material that is resistant to wear. The size and shape of the clamping plate  22  and clamp wearing plate  23  may vary depending on the block or product size. The clamp wearing plate  23  is secured to the clamping plate  22  with bolts, screws, tabs or other fasteners. In some applications, the clamp wearing plate  23  may be eliminated.  
         [0024]    As shown in FIGS. 1 and 3, the alignment guides  30  are generally rectangular plate elements constructed of metal or synthetic material of high strength. Preferably, a low-friction plate  32  is secured to the alignment guides  30 . This may be done with bolts, screws or other fasteners. The low-friction plate  32  is preferably of a high density polyethylene or other synthetic material. The low-friction plate  32  functions to reduce friction between the alignment guides and passing product, and/or facilitate alignment by allowing the product to easily shift into square between the guides  30 . As desired, the low-friction plate  32  may be absent. The alignment guides are generally guided toward one another in a consistent manner with the aid of the linkage  40 . Preferably, the guides  30  are pivotally mounted with mounting pin  35  to the alignment slide member  17 . As will be appreciated, other mechanisms for ensuring that the alignment guides  30  move toward each other in a consistent manner may be used.  
         [0025]    With particular reference to FIGS.  3 - 5 , the alignment guides  20  and clamping plate  22  are coupled together with linkage  40 , which generally includes clamp arm  24 , guide pin  26 , which interfits within journal  36 , and guide arm  34 . Preferably, the clamping plate  22  is mounted to clamp arm  24 , which is preferably mounted on the side of the clamping plate opposite the clamp wearing plate  23 . The clamp arm  24  may be secured to the clamping plate  22  by a weld or fasteners such as bolts or screws. Optionally, multiple clamp arms  24  may be secured to the clamping plate. Secured to the clamp arm  24  is guide pin  26  which may be a pin, bolt, shaft or other structure coupled to the clamp arm  24 . Although the cross section of guide pin  26  is shown annular, it may be elliptical, square or rectangular, or any other desired shape.  
         [0026]    With further reference to FIGS. 3 and 5, the guide arm  34  is secured to or integral with alignment guide  30 . Guide arm  34  includes journal  36  including opposing journal ends  36   a  and  36   b . The journal  36  is preferably in the form of a slot, but may be any open channel or other guide mechanism that allows guide pin  26  to move relative to the guide arm  34  in certain positions and engage the guide arm  34  in other positions. Stabilizer arm  38  is secured to or integral with guide arm  34 . As will be appreciated, stabilizer arm  38  may be secured directly to the alignment guide  30  as well. The stabilizer arm  38  extends over the drive arm  21 . Preferably, friction block  39  is disposed between the stabilizer arm  38  and the drive arm  21 . The friction block is constructed of a low friction material to reduce abrasion and wear between the stabilizer arm  38  and the drive arm  21 . As will be appreciated, the friction block  39  may be secured to or integral with stabilizer arm  38  or the drive arm  21  as desired.  
         [0027]    With reference to FIGS.  3 - 5 , the clamping guide  10  may also include an adjuster  60  to fine-tune the spatial relationship between the alignment guides  30 , the clamping guides  20 , and their movement relative to procession B. As shown, the adjuster  60  includes bracket  64  to which set screw  62  is movably coupled. The bracket  64  is mounted in a stationary position relative to the alignment guides  30 , preferably to the clamping guide frame member  19 . The function of the set screw  62  is to adjust the positioning of the guide pin  26  within the guide journal  36  and, therefore, adjust the spatial relationship of the alignment guide  30  with respect to the clamp  20 . Locking nut  66  may be tightened against bracket  64  to prevent movement of the set screw  62  relative to the bracket  64 .  
       Operation  
       [0028]    With reference to FIGS. 1, 3 and  4 , the operation of the clamping guide  10  will now be explained. As shown in FIG. 1, a procession of blocks B are conveyed by power conveyor  100  downstream in the direction of arrow A toward patterning conveyor  200  or any other block manipulating station as desired. To initiate stopping the procession of blocks B toward the downstream patterning station, the power conveyor  100  is shut down so that it no longer propels the procession of product B, however, downstream. Upstream line pressure from blocks accumulating in the procession B naturally urges the blocks on the power conveyor  100  downstream toward the patterning station  200 .  
         [0029]    To prevent the procession B from flowing downstream and affecting tasks performed on the patterning station  200 , and to align blocks in the procession B, the clamping guides  10  are activated. The clamps  20 , and consequently, the alignment guides  30  are driven inward, toward the product procession B, by the clamp actuators  50 . Clamps  20  clamp against block B 2  (or more blocks if more blocks are between the clamps), to prevent block B 2  from moving past the clamps  20 . Via the linkage  40 , the guides  30  are actuated simultaneously with the clamps  20 . The alignment guides push upstream mis-aligned blocks, for example, B 1 , into alignment so that the procession B generally includes aligned blocks. Preferably, the alignment guides  30  align, but do not clamp against the blocks. Specifically, if only the alignment guides  30  contacted blocks in procession B, the force in contact would not be sufficient to stop the procession B from progressing downstream due to upstream line pressure. Optionally, however, some alignment guides may actually clamp blocks in procession B.  
         [0030]    With reference to FIGS. 3 and 4, the interaction of the alignment guides  30 , linkage  40  and clamps  20  is shown in more detail. As clamp actuator  50  is actuated, ram  52  drives drive arm  21 , and subsequently clamp plate  20 , in an extending direction C toward and into contact with block B 2 . As clamp arm  24  moves with clamping plate  22  the guide pin  26  moves within the journal  36 . When the guide pin  26  contacts the journal end  36   a , this causes the alignment guide  30  to move inward in direction C toward block B 1 , which is upstream from block B 2 .  
         [0031]    Preferably, the guide pin  26  and guide arm  34  interact so that in a fully extended position as shown in FIG. 3, the clamp plate  22  clamps against the block B 2  whereas the alignment guide  30  and friction-reducing plate  32  align, but do not exert a force that prevents or restricts blocks therebetween from being pushed downstream due to upstream line pressure. More preferably, the effective pressure of the clamping guides against the blocks B 1  therebetween is enough to align but not clamp the blocks. Additionally, the set screws  62  may be used to establish the most retracted position of the alignment guides, as shown in FIG. 4. There, the set screw  62  abuts the alignment guide  30  so that it cannot be retracted farther than illustrated.  
         [0032]    After the alignment guides  30  have aligned the procession of product therebetween and/or the operations downstream from the clamping guide  10  are completed, the clamp actuator  50  retracts, thereby retracting the clamp plate  22  and alignment guide  30  toward a retracted position as shown in FIG. 4. As the clamp actuator  50  moves the clamp plate  22  in direction  0 , the guide pin  26  moves relative to the journal  36  until it engages journal end  36   b . At this point, the alignment guide  30  begins to move in direction O with the clamping plate  22 . With reference to FIG. 2, the alignment guide pivots about the mounting pin  35  so that the guides are at a slight angle with respect to the product procession D. With reference again to FIGS. 3 and 4, the stabilizer arm  38  slides relative to the drive arm  21  as the clamps  20  and alignment guides extend in direction C toward the procession of blocks or retract in direction O away from the procession. The interaction of the stabilizer arm and drive arm  21  holds the alignment guide  30  off the conveyor  100 . Additionally, the stabilizer arm  38  restricts or prevents the alignment guide  30  from excessively tilting or angling from the vertical and horizontal planes.  
         [0033]    Preferably, the guide pin  26  engages the journal end  36   b  so that as the clamps  20  are retracted, the alignment guides  30  lag behind the clamps  20  some distance D. In the fully retracted position, the alignment guides are closer to the product procession a distance D. The set screw  62  may be used to establish this distance D by screwing it into or out from the bracket  64 . Accordingly, the alignment guides  30  shield edges of the clamps  20  from product. With this feature, individual blocks moving on the conveyor are less prone to snag on the edges  29  of the clamps  20  and misalign.  
         [0034]    After the procession of blocks has been stopped and the blocks upstream from the clamps align between the alignment guides  30 , the power conveyor  100  is re-power to move the next block or group of blocks to the patterning station. The process explained above is then repeated again to stop and align the next portion of the product procession.  
         [0035]    Although the preferred embodiment of the clamping guide includes pairs of opposing clamps and opposing alignment guides that move toward each other to clamp and align a portion of a procession of product, the clamping guide may alternatively include one clamp and one alignment guide on one side of the power conveyor  100  and a fixed plate or frame member (not shown) on the opposite side of the procession. The operation of this embodiment is identical to that of the preferred embodiment except that a portion of the procession of blocks is clamped and aligned against a fixed member rather than a second set of clamps and alignment guides.  
         [0036]    The above descriptions are those of the preferred embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular.