Abstract:
A lift assembly for use in conjunction with a conveyor to lift item(s) off of the conveyor and remove the item(s) from the conveying path. The lift assembly may include a housing having housing side walls and a bottom wall, and a carriage having carriage side walls and a carriage bottom wall. The carriage is movable with respect to the housing. The lift assembly may further include a track that receives a guide member of the carriage for guiding the carriage as it is raised and lowered with respect to the housing. The lift assembly may further include an actuator that causes the carriage to be raised and lowered.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims the benefit of provisional patent application Ser. No. 61/392,710 filed Oct. 13, 2010, the entirety of which is hereby expressly incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a lift assembly for use in conjunction with a conveyor system, for lifting an item off of the conveyor system to remove the item from the conveying path. 
     BACKGROUND AND SUMMARY 
     In operation of a conveyor system, it is sometimes desirable to lift an item or items off of and above the conveying member of the conveyor system, thus preventing movement of the lifted item or items along the conveying path. The lifting of an item or items off the conveying member is typically coupled with advancing upstream item(s) along the conveying path, in order to eliminate spaces between conveyed items and therefore maximize the efficiency of operation of the conveyor system. In this manner, the conveyed items can be accumulated on the conveying path at the location of the furthermost downstream items for subsequent movement and processing. 
     The present invention is directed to a lift assembly for use with a conveyor system, which is operable to lift the conveyed item(s) above the conveying member of the conveyor system. In one embodiment, the lift assembly of the present invention includes a housing, a carriage supported by the housing, a track, and a guide member received within the track and operably attached to the carriage. The guide member moves along the track as the carriage is raised and lowered with respect to the housing. The lift assembly may further include an actuator that is attached to the housing on one end and to the carriage on the other. The housing may have two side walls located one on either side of a conveying path and a bottom wall between the two side walls. The carriage is supported by the housing and includes two carriage side walls located one on either side of the conveying path, a carriage bottom wall, and a pair of supports. Each support is supported by a respective carriage side wall and extends inwardly toward the conveying path. The lift assembly may include a pair of guide members, with each guide member being supported by a respective carriage side wall. A pair of tracks guide the carriage as it is raised and lowered with respect to the housing. Each track receives a respective guide member. Further, the lift assembly includes an actuator for raising and lowering the carriage with respect to the housing. The track may be in the form of a slot in a wall, or it may be formed by a bracket attached to a wall. 
     In another embodiment, the lift assembly includes a housing having two side walls located one on either side of a conveying path and a bottom wall below the conveying path. The carriage is supported by the housing that includes two carriage side walls located one on either side of the conveying path, a carriage bottom wall, and a pair of supports. Each support is supported by a respective carriage side wall and extends inwardly toward the conveying path. The carriage further includes a pair of guide members that are supported by a respective carriage side wall. The lift assembly includes a pair of tracks that guide the carriage as it is raised and lowered with respect to the housing, with each track receiving a respective guide member. Further, an actuator raises and lowers the carriage with respect to the housing. One end of the actuator is attached to the housing and the opposite end of the actuator is attached to the carriage, and the actuator is situated between the side walls of the housing. The carriage bottom wall may have an aperture through which the actuator extends. In such a configuration, the actuator may be attached to an upper surface of the carriage bottom wall. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated in the accompanying drawings in which like reference numerals represent like parts throughout. 
       In the drawings: 
         FIG. 1  is an isometric view of one embodiment of a conveyor lift assembly in accordance with the present invention; 
         FIG. 2  is an end elevation view of the lift assembly of  FIG. 1 ; 
         FIG. 3  is a top plan view of the lift assembly of  FIG. 1 ; 
         FIG. 4  is a side elevation view of the lift assembly of  FIG. 1 ; 
         FIG. 5  is a section view of the lift assembly of  FIG. 1  taken along line  5 - 5  of  FIG. 3 ; 
         FIG. 6  an isometric view of a conveyor system incorporating the lift assembly of  FIG. 1 ; 
         FIG. 7  is a top plan view of the conveyor system of  FIG. 6 ; 
         FIG. 8  is a side elevation view of the conveyor system of  FIG. 6 ; 
         FIG. 9  is an enlarged partial side view of the conveyor system of  FIG. 6 ; 
         FIG. 10  is an isometric view of a second embodiment of the lift assembly of the present invention; 
         FIG. 11  is a cross-sectional view of the lift assembly of  FIG. 10  taken along line  11 - 11  of  FIG. 10 ; 
         FIG. 12  is a cross-sectional view of the lift assembly of  FIG. 10  taken along line  12 - 12  of  FIG. 10 ; 
         FIG. 13  is a cross-sectional view of the lift assembly of  FIG. 10  taken along line  13 - 13  of  FIG. 10 ; 
         FIG. 14  is an isometric view of the lift assembly of  FIG. 10  in a lowered position; 
         FIG. 15  is a side elevation view of the lift assembly of  FIG. 10  in the lowered position; 
         FIG. 16  is an isometric view of the lift assembly of  FIG. 10  in a raised position; and 
         FIG. 17  is a side elevation view of the lift assembly of  FIG. 10  in the raised position. 
     
    
    
     DETAILED DESCRIPTION 
     A conveyor system  10  including one embodiment of a lift assembly  30  of the present invention is shown in  FIGS. 1-9 . The conveyor system  10  includes side rails or supports  12  that are substantially parallel to one another. The side supports  12  cooperate to define a conveying path  14  along which items may be transported by one or more conveying members  16 , e.g., a belt (or multiple belts), tabletop assembly, etc. In one embodiment, the side supports  12  extend above the conveying member  16  to prevent items from falling off of the conveyor system  10 . 
     A series of support members  18  cooperate with the side supports  12  to form a frame  11  of the conveyor system  10 . The support members  18  are spaced apart from one another along the conveying path  14  and are substantially perpendicular to the side supports  12 . The number and spacing of support members  18  may vary as desired. 
     In addition to the conveying member  16 , the conveyor system  10  includes guide rails  17  that are substantially parallel to the conveying member  16  and side supports  12 . The guide rails  17  are supported by and may be secured to the support members  18 . In one embodiment there are three spaced apart guide rails  17  that support a conveying member  16 . See  FIG. 6 . However, the number of guide rails  17  may vary as desired. For example, the embodiment shown in  FIG. 14  has four guide rails  17 . The guide rails  17  help to guide the conveying member  16 , which is driven by an actuator (not shown) such as a motor in a manner as is known, along the conveying path  14  so that the conveying member  16  remains aligned with respect to the conveying path  14 . 
     The conveyor assembly  10  further includes a lift assembly  30  that enables an item or items to be lifted off of and above the conveying member  16 , thus preventing the conveying member  16  from moving the lifted item or items along the conveying path  14 . Such a function, i.e., preventing an item from being transported along the conveying path  14  while allowing for the transportation of additional items along the conveying path  14 , is desirable under certain circumstances. For example, in order to maximize the efficiency of the conveyor assembly  10 , when down-stream items are lifted off of the conveying member  16  it may be desirable to continue to move up-stream items along the conveying path  14  until they reach the stopped, down-stream items. In other words, it is desirable to accumulate the items on the conveying path  14  at the furthest possible down-stream point until the stopped items can again be moved, to eliminate gaps between the items being conveyed. 
     The lift assembly  30  includes a bottom wall  31  and side walls  32 . The side walls  32  are substantially parallel to one another and are substantially perpendicular to the bottom wall  31 . The side walls  32  may be integral with the bottom wall  31 , or, alternatively, the side walls  32  may be attached to the bottom wall  31  by any suitable means, e.g., bolts, screws, welds, etc. The side walls  32  and bottom wall  31  cooperate to form a housing  35  for a carriage  40  that may be raised and lowered by an actuator  50 . 
     As shown in  FIG. 2 , the carriage  40  has a U-shaped cross section with two inwardly extending supports  43  in the form of plates at the top of the carriage  40 . The U-shaped portion of the cross-section of the carriage  40  is formed by a carriage bottom wall  41  and two carriage side walls  42 . The carriage side walls  42  are substantially parallel to one another and substantially perpendicular to the carriage bottom wall  41 . The supports  43  extend inwardly from the top ends of respective carriage side walls  42 . The carriage bottom wall  41 , carriage side walls  42 , and supports  43  may be integral with one another, or they may be separate components attached to one another by any suitable means, e.g., screws, bolts, welds, etc. The carriage  40  is sized to fit within the housing  35 . 
     The lift assembly  30  further includes a pair of guide walls  36  that function to guide the carriage  40  as it is raised and lowered with respect to the housing  35 . As shown in  FIG. 2 , the guide walls  36  are substantially parallel to one another. Each guide wall  36  is situated between a respective side wall  32  and carriage side wall  42 . Each guide wall  36  includes a track  37  that houses a guide member  44 , e.g., a roller, that is attached to the carriage  40 . In the embodiment shown in  FIG. 1 , the respective tracks  37  are aligned on opposite sides of a longitudinal axis of the housing  35 , e.g., a longitudinal axis along which the actuator  50  is aligned. 
     In one embodiment, the carriage  40  has a pair of rollers  44  that extend beyond each carriage side wall  42 . Each guide wall  36  has two corresponding tracks  37  to receive a respective pair of rollers  44 . As shown in  FIG. 1 , the track is in the form of a slot in the guide wall  36 . The track  37  in the guide wall  36  is angled, thus providing a ramp along which the roller  44  may travel as the carriage is raised and lowered by the actuator  50 . As shown in  FIGS. 1 and 4 , the track  37  is angled upwardly in the general direction of the conveying path  14 . Accordingly, as the carriage  40  is raised it also travels horizontally in the direction that items are conveyed along the conveying path  14 . 
     It should be noted that the guide member  44  is not limited to a roller. The guide member  44  can take the form of any structure capable of being received within and guided by a corresponding track  37 . It should be further noted that the track/guide member arrangement could be reversed. In other words, the guide member  44  could be associated with the guide wall  36  while the track  37  could be associated with the carriage  40 . 
     The lift assembly  30  further includes at least one actuator  50 . As shown in  FIG. 3 , one embodiment features a single actuator  50  that is generally centered between the side walls  32  of the housing  35 . On one end, the actuator  50  is pivotably coupled to a bracket  52  that is secured to the bottom wall  31  of the lift assembly  30 . The other end of the actuator  50  is rotatably coupled to a bracket  53  that is secured to the carriage  40 . As shown in  FIG. 1 , the actuator  50  extends through an aperture  45  in the bottom wall  41  of the carriage  40 . The aperture  45  is sized to enable the actuator  50  to freely extend and retract so as to raise and lower the carriage  40  as desired. Alternatively, the aperture  45  could be eliminated and the actuator  50  could be attached to a bottom side of the bottom wall  41  of the carriage  40 . 
     As shown in  FIG. 7 , in one embodiment the actuator  50  is positioned within the footprint of the conveying system  10  and is situated beneath the conveying member  16 . Moreover, the actuator  50  may be centered between the side supports  12  of the conveying system  10 . 
     In one embodiment, the actuator  50  is a pivotably mounted piston assembly. Thus, during operation, the piston rod is extended to move the carriage  40  along the tracks  37  in the guide walls  36 . Since the tracks  37  are angled upwardly in the same general direction in which the piston rod extends, the carriage  40  is driven upward to a raised position along the tracks  37  by the actuator  50 . Conversely, as the piston rod is retracted, the carriage  40  is pulled downwardly along the tracks  37 , thus lowering the carriage  40  with respect to the housing  35  to its initial, lowered position. 
     As shown in  FIGS. 6-9 , the lift assembly  30  may be integrated into the conveyor system  10 . More specifically, the lift assembly  30  is sized to fit between the side supports  12  of the conveyor system  10 , and it is positioned such that the side walls  32  are substantially parallel to the side supports  12 . The lift assembly  30  is positioned so that the conveying member  16  and guide rails  17  are positioned between the supports  43  of the lift assembly. In other words, there is a gap  46  between the supports  43  within which the conveying member  16  and guide rails  17  are situated. In one embodiment, corresponding lift members  47  may be attached to the supports  43 . The lift members  47  may be integral with the supports  43 , or they may be separate components that are attached to respective supports  43  by any suitable means. 
     When the carriage  40  is in the lowered position, the top surface of the support  43  (and lift member  47 , if applicable) lies in a plane that is lower than the top surface of the conveying member  16 . See, e.g.,  FIGS. 14 and 15 . Thus, the support  43  (and lift member  47 , if applicable) will not contact, and therefore will not interfere with, the transportation of the item(s) along the conveying path  14 . Alternatively, the top surface of the support  43  (and lift member  47 , if applicable) may lie in the same plane as the top surface of the conveying member  16 . Accordingly, item(s) may slide along the support  43  (and lift member  47 , if applicable) while being transported by the conveying member  16  along the conveying path  14 . When the support  43  is raised, the top surface of the support  43  lies in a plane that is higher than the top surface of the conveying member  16 , to suspend movement of the item(s). See, e.g.,  FIGS. 16 and 17 . 
     Another embodiment of the lift assembly  30  of the present invention is shown in  FIGS. 10-16 , and like reference characters will be used where possible to facilitate clarity. In this embodiment, the tracks  37  are separate components, such as brackets, that are attached to the side walls  32  with one or more fasteners, e.g., bolts. Alternatively, the tracks  37  may be integral with the side walls  32 . As shown in  FIG. 11 , the tracks  37  are sized to receive the guide member  44 . In this embodiment, the guide wall  36  has been eliminated. 
     As shown in  FIGS. 14 and 16 , the actuator  50  lies within the footprint of the conveying member  16 . The actuator  50  is aligned along a central longitudinal axis of the conveying member  16 , and the lift members  47  are evenly spaced on either side of the central longitudinal axis of the conveying member  16 . Thus, the load of an item to be lifted may be evenly distributed with respect to the lift members  47  and actuator  50 . 
     Multiple lift assemblies  30  may be incorporated into the conveyor system  10  in a sequential manner to form zones  19  along the length of the conveyor system  10 . In such an arrangement, each lift assembly  30  would correspond to a respective zone  19  within the conveyor system  10 . See  FIG. 8 . 
     Various alternatives and modifications are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.