Patent Publication Number: US-2007116529-A1

Title: Method for conveying flexible fabrics using dual side outlets

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is a Divisional Application that claims the benefit of U.S. patent application Ser. No. 11/042,373 filed Jan. 25, 2005. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
      Not applicable.  
     TECHNICAL FIELD  
      This invention relates generally to the handling of flexible fabric or plastic items such as uniforms, table linens and other articles that are commonly handled by commercial laundries and other facilities. More particularly, the invention is directed to a method and apparatus for conveying and sorting flexible fabric items using a conveying system having dual side outlets.  
     BACKGROUND OF THE INVENTION  
      U.S. Pat. No. 6,619,525 to Frankeberger et al. discloses a pneumatic fabric conveyor which is used to deliver flexible fabric items from a sorting area or table to receptacles such as sling carts. The discharge end of the conveyor system is provided with bottom outlets that are controlled by flapper valves which direct the fabric items into receptacles arranged in a row beneath the outlets.  
      Although this construction functions well, it is subject to capacity limitations due to the single row of receptacles that must be located directly below the conveyor tube. Additionally, when a sling cart is full, no more articles can be discharged through the corresponding outlet until the full cart has been moved and replaced by an empty cart. The ability of the system to function efficiently and at a high capacity is reduced as a result of these limitations.  
     SUMMARY OF THE INVENTION  
      The present invention constitutes an improvement in the system shown in U.S. Pat. No. 6,619,525. In particular, the principal goal of the invention is to increase the capacity and efficiency of a pneumatic conveying and sorting system of the type shown in that patent. A counting or weighing control device may or may not be used.  
      More specifically, it is an object of the invention to provide a method and apparatus for conveying flexible fabric items that makes use of a pair of side outlets at each discharge location, thereby doubling the discharge capacity without adding to the linear space that is occupied by the conveying system.  
      Another object of the invention is to provide a method and apparatus of the character described in which each outlet may be provided with a hopper that receives the fabric items and directs them through a chute into an underlying receptacle such as a sling cart, or a sling on a monorail.  
      An additional object of the invention is to provide a method and apparatus of the character described in which the hopper chutes may be equipped with doors that can be closed to allow the underlying cart to be replaced while fabric items continue to be loaded into the hopper. By using the hoppers as holding bins in this manner, the conveying operation can continue uninterrupted while full carts are replaced as necessary with empty carts. As a result, the throughput of the system is not adversely effected by the need to interchange carts.  
      A further object of the invention is to provide a method and apparatus of the character described wherein the space occupied by the conveyor equipment is minimized. In this regard, the capacity can be doubled without adding to the linear space required by the equipment.  
      Yet another object of the invention is to provide a method and apparatus of the character described that is distinguished by simplicity, low cost and ease of use.  
      Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
      In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:  
       FIG. 1  is diagrammatic perspective view of a fabric conveying system that is equipped with dual side outlets in accordance with a preferred embodiment of the present invention; and  
       FIG. 2  is a fragmentary perspective view of part of the discharge end portion of the conveying system, with portions broken away to show certain internal details and with the hopper doors on one of the hoppers shown in the open position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to the drawings in more detail and initially to  FIG. 1  in particular, numeral  10  generally designates a pneumatic conveying system that is used to convey flexible fabric items such as table lines (tablecloths, napkins and the like), uniforms, and other articles that are commonly laundered in commercial laundry or other textile industry facilities, as well as other types of flexible fabrics, plastic bags or other lightweight flexible material that can be pneumatically conveyed in other applications. A sorting table  12  or a similar sorting station may be supported on legs  14  and used for the sorting of fabric articles that are to be conveyed by the conveying system  10 . The sorting table  12  is located at the inlet end of the conveying system and connected with the piping of the conveying system.  
      The conveying system includes a closed conveyor tube which is generally identified by numeral  16 . The conveyor tube  16  extends from the sorting table  12  and is located for the most part at an overhead location, although other locations are possible. The length, size and configuration of the conveyor tubing can be varied as desired to accommodate the space that is available and the application in which the conveying system is used.  
      The conveyor tube  16  may include a vertical inlet tube  18  that extends upwardly from a trough  20  on the sorting table  12 . The tube  18  provides an inlet to the conveyor system through which the fabric articles are fed. The top end of tube  18  connects through an elbow fitting  22  with a horizontal tube  24 . A frame  26  may be provided with a plurality of legs  28 , or the frame  26  may be supported otherwise such as by being suspended from a ceiling. The frame  26  provides support for the overhead tubing and a venturi which is generally identified by numeral  30 . The venturi  30  may be of the type shown in U.S. Pat. No. 6,619,525 which is incorporated by reference as disclosing a type of venturi construction that can be used in the conveyor system  10 . Tube  24  extends to the venturi  30 . A blower  32  has its discharge side  34  connected with the venturi  30  in order to provide a low pressure area in the venturi  30  for drawing fabric items through the conduits  18  and  24  and conveying them downstream from the venturi  30 , as disclosed in U.S. Pat. No. 6,619,525. The downstream end of the venturi  30  is provided with a horizontal tube  36  that may lead to a vent structure  38  which provides a vent effect as disclosed in U.S. Pat. No. 6,619,525.  
      Alternatively, the vent of vent structure  38  may connect with a return pipe  38   a . The return pipe  38   a  may connect with a horizontal conduit  39  which connects with the inlet side of blower  32 . An adjustable door  39   a  on the end of conduit  39  may be slid to expose more or less of the end of conduit  39  to adjust the fresh air intake area to conduit  39 . This closed loop system is advantageous in many respects compared to a simple vent system, although the present invention contemplates a simple vent system as well as the closed loop system shown in the drawings.  
      The downstream side of the vent structure  38  connects with a horizontal tube  40  which in turn connects with a square conduit  42  located on the discharge end portion of the conveyor system  10 .  
      With additional reference to  FIG. 2 , the conduit  42  has flat opposite sides  46  located in vertical planes. Each of the sides  46  is provided with a plurality of outlets  48 , with the outlets being arranged in aligned pairs located on opposite sides  46  of conduit  42 . The outlets  48  open into the upper end portions of respective hoppers  50  which are connected with the opposite sides  46  of conduit  42  and supported in part by the frame  26 . One of the hoppers  50  is provided for each of the outlets  48 . By way of example,  FIG. 1  shows an arrangement in which there are five of the outlets  48  on each side of conduit  42  so that there are five of the hoppers  50  on each side of conduit  42 . Hoppers  50  are arranged in pairs located on opposite sides of the conduit  42 , and the hoppers  50  on each side of the conduit are arranged in a straight row extending parallel to conduit  42  and located slightly to one side of it.  
      Referring again to  FIG. 2  in particular, each of the outlets  48  is provided with a gate  52 . Each gate  52  is mounted on a vertical shaft  54  which may be rotated to move the gate  52  between open and closed positions. In the closed position of gate  52 , the gate covers the corresponding outlet  48  to close the outlet  48  and prevent fabric items from discharging through it. In the open position of gate  52  (shown for one of the gates in  FIG. 2 ), the gate is swung inwardly such that it intercepts fabric items passing through the conduit  42  and prevents them from moving downstream past the open gate. The open gate  42  exposes the corresponding outlet  48  and deflects the incoming fabric item or items through the open outlet  48  and into the corresponding hopper  50 . The gates  52  thus act as valves for the outlets  48  and may be moved between the open and closed positions by a pneumatic cylinder  56  or by any other suitable actuating means.  
      Each of the hoppers  50  is provided on its lower end with a chute  58  which presents a discharge opening  60  in the bottom end of each chute. Immediately underlying each of the hoppers  50  is a receptacle  62  which may take the form of a sling cart or bin mounted on wheels (or a sling hanging from a overhead monorail system)  64  (see  FIG. 1 ). Each of the receptacles  62  has an opening  66  in its upper end which underlies the discharge opening  60  in the bottom of the corresponding hopper  50 . There is one receptacle  62  for each hopper  50 , and the receptacles  62  are arranged in two straight rows located on opposite sides of conduit  42 .  
      Chute  58  of each hopper  50  may be provided with a pair of hopper doors  68  which are used to open and close the opening  60 . When the doors  68  are closed, they block the opening  60  and cause the fabric items in the hopper  50  to be retained within the hopper. When the doors  68  are opened, the opening  60  is exposed so that the fabric items within the hopper  50  are discharged by gravity through opening  60  and into the underlying receptacle  62  through opening  66 . The doors  68  of each hopper may be opened and closed by pneumatic cylinders or any other suitable means that can be actuated as needed.  
      The end of conduit  42  may connect with a vertical tube  44  (see  FIG. 1 ) or, more preferably, with a hopper and bin system like those described previously. Thus, if all of the doors  52  are closed, the items that are being conveyed are directed into the hopper on the end and eventually into the bin on the end.  
      In operation of the system  10 , the fabric items or other lightweight flexible items are loaded into the conveying system through the inlet tube  18 . Blower  32  and venturi  30  create a low pressure region which draws the fabric items through the conveyor tube  16  and conveys them into the conduit  42  on the discharge end of the conveying system. The vent effect provided by the vent  38  assists in the conveying operation.  
      As the fabric items are conveyed through conduit  42 , gates  52  are selectively opened and closed to direct the fabric items into proper hoppers  50 . The fabric items may be provided with indicia which may be read by suitable sensors in the conveying system in order to identify and/or count each particular fabric item and open and close the gates  52  in a manner to direct that item into the hopper  50  that is appropriate for that particular fabric item. Only one of the gates  52  is open at any time, so each of the fabric items is directed into the appropriate hopper  50  as determined by the open gate. The doors  68  of the hoppers  50  are normally open, so the fabric items that are directed into the hoppers are delivered from the hoppers into the underlying receptacles  62 . Thus, for example, all uniform shirts of a particular type can be directed into one of the receptacles  62 , napkins can be directed into another of the receptacles  62 , and tablecloths can be directed into still another of the receptacles  62 .  
      When one of the receptacles  62  is full of materials, doors  68  of the overlying hopper  50  can be temporarily closed (automatically or by the action of a human operator) so that the full receptacle  62  can be moved and replaced with an empty receptacle while the conveying operation continues uninterrupted and the fabric materials continue to be loaded into the hopper  50 . While its doors  68  are closed, the hopper  50  accumulates the fabric items within it and thus serves as a holding bin while the receptacles  62  are interchanged. Once an empty receptacle  62  has been moved into place beneath the hopper  50 , doors  62  can be opened again, and the fabric items that have accumulated within the hopper  50  are then discharged into the receptacle  62 .  
      By providing a pair of the outlets  48  at each discharge location along the length of the conduit  42 , the discharge capacity of the conveyor is doubled in comparison to the unit shown in U.S. Pat. No. 6,619,525 which has only a single bottom outlet at each discharge location. The throughput is thus doubled in this fashion without the need to increase the length of the conveyor tubing. The receptacles  62  are located in two separate straight rows which are located generally on opposite sides of the conduit  42  so that they add slightly to the overall width but not to the length. Additionally, by using the hoppers  50  as temporary holding bins when the receptacles  62  are full, the conveying operation can continue uninterrupted while the receptacles are interchanged, thus increasing the throughput and efficiency of the conveying operation.  
      From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.  
      It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.  
      Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.