Abstract:
A lifting apparatus for lifting paint containers into and out of paint mixers of the type supported by a generally horizontal surface and including at least one side, the lifting apparatus having a pair of rigidly connected arms, each including a proximal end pivotably connected to a support structure and a distal end extending from the support structure, a mechanical link in the form of a strap and hook connected to a cross member connecting each of the pair of arms for lifting and lowering a paint bucket into and out of the paint mixer and a pair of gas springs connected between the support structure and the lifting arms for urging the lifting attachment upwards. The support structure may be separate from the paint mixer and may include sliding as well as pivoting movement between the arms and the support structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a Continuation-In-Part of application Ser. No. 10/818,996, filed Apr. 6, 2004 which is a Continuation of application Ser. No. 10/235,978, filed Sep. 5, 2002 now U.S. Pat. No. 6,729,754, the entire contents of each of which are hereby incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    Powered mixers are popular in retail outlets selling paint. When the paint is vended in five gallon buckets (or similar containers), considerable effort required to lift the buckets into and out of the mixers. One form of assistance has been to provide a roller conveyor in front of one version of a paint mixer to raise the bucket to a height at or near that necessary to slide the bucket into the mixer. However, with “drop-in” type paint mixers further lifting effort is still required to move the bucket between the conveyor and mixer. The present invention reduces this effort and provides an attachment that makes it easier to lift five gallon buckets or similar containers of paint into and out of “drop-in” type paint mixers. The present invention will accomplish its function whether or not a conveyor is present in front of the mixer.  
         BRIEF SUMMARY OF THE INVENTION  
         [0003]    The present invention, in one aspect, includes a lifting apparatus for lifting paint containers into and out of paint mixers, where the lifting apparatus is useable in combination with the paint mixer and includes a generally horizontal surface with at least upright member supporting at least one lifting arm including a proximal end pivotably connected to the upright member and a distal end extending beyond the paint mixer, a mechanical link connected to the lifting arm intermediate the proximal and distal ends for lifting and lowering a paint container into and out of the paint mixer, and a spring means connected to the lifting arm for urging the lifting arm vertically upwards.  
           [0004]    The present invention, in another aspect, includes a method of assisting movement of a paint container into and out of a paint mixer according to the steps of providing a lifting attachment having at least one lifting arm with a proximal end pivotably connected to a support and a distal end extending beyond the paint mixer, a mechanical link connected to the lifting arm intermediate the proximal and distal ends for lifting and lowering a paint container into and out of the paint mixer, and spring means connected to the lifting arm for urging the lifting arm vertically upwards, engaging the mechanical link to the paint container; and assisting movement of the paint container with respect to the mixer by moving the lifting arm with the assistance of the spring means.  
           [0005]    In one aspect the present invention is separate from the paint mixer with its own support structure and may be pivotable or pivotable and slideable with respect to the support structure. The sliding version may utilize a separate support structure or the paint mixer as the support structure. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a perspective view from the front and above of a conveyor and paint mixer with the lifting attachment of the present invention shown with a paint bucket in the mixer.  
         [0007]    [0007]FIG. 2 is a side elevation view of the mixer and attachment of FIG. 1.  
         [0008]    [0008]FIG. 2 a  is an enlarged view of a portion of FIG. 2 showing the lifting attachment assembly.  
         [0009]    [0009]FIG. 2 b  is a front elevation view of the mixer and attachment of FIG. 1.  
         [0010]    [0010]FIG. 2 c  is an exploded view of a weldment subassembly with associated parts useful in the practice of the present invention.  
         [0011]    [0011]FIG. 2 d  is an exploded view of the lifting attachment assembly.  
         [0012]    [0012]FIG. 3 is a view similar to FIG. 1, except with the paint bucket on the conveyor and the lifting attachment connected to the bucket in a first position.  
         [0013]    [0013]FIG. 4 is a view similar to that of FIG. 3, except with the lifting attachment raised to lift the bucket to a second position.  
         [0014]    [0014]FIG. 5 is a view similar to that of FIG. 4, except with the bucket moved laterally and rotated to a position in which the bucket is about to be received in the mixer while still supported by the lifting attachment.  
         [0015]    [0015]FIG. 6 is a view similar to that of FIG. 5, except with the bucket fully received in the mixer and with the lifting attachment lowered to a position just prior to release from the bucket.  
         [0016]    [0016]FIG. 7 is a view similar to FIG. 3 except without a conveyor and with the bucket elevated slightly above the surface supporting the paint mixer.  
         [0017]    [0017]FIG. 8 is a view similar to that of FIG. 5, except with a single handle.  
         [0018]    [0018]FIG. 9 is an alternative embodiment showing a single arm version of the lifting attachment useful in the practice of the present invention.  
         [0019]    [0019]FIG. 10 is another alternative embodiment of the present invention in a free-standing form useful in the practice of the present invention.  
         [0020]    [0020]FIG. 10 a  is a simplified plan view of an arrangement for the practice of the present invention.  
         [0021]    [0021]FIG. 10 b  is a simplified plan view of an alternative arrangement for the practice of the present invention.  
         [0022]    [0022]FIG. 11 is still another alternative embodiment of the present invention using a sliding and pivoting motion in the practice of the present invention.  
         [0023]    [0023]FIG. 12 is another alternative embodiment of a support structure for the lifting apparatus of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0024]    Referring now to the Figures, and most particularly to FIG. 1, a paint mixer  10 , together with a lifting attachment  12  useful in the practice of the present invention, may be seen. Paint mixer  10  is preferably a Model 5305, available from Red Devil Equipment Co., 7150 Boone Avenue North, Suite 100, Brooklyn Park, Minn. 55428. In the past, it was necessary to manually lift a five gallon paint container or bucket  14  into and out of the mixer. The lifting attachment  12  of the present invention reduces the effort required to move the paint container  14  into and out of the mixer  10 . Typically, a conveyor  16  is located in front of the mixer and preferably extends from a colorant dispenser or tinting station (not shown) to the mixer  10  to assist in moving the five gallon buckets  14  of paint from the tinting station to a mixing station at the mixer. It is to be understood that additional conveyor segments are typically present to extend the length of the conveyor  16  as desired. It is also to be understood that bucket  14  has a bail  18  and handle  20 . A door or hood  22  is pivotably attached to mixer  10  and is closed prior to operating mixer  10 . As may be seen most clearly in FIG. 2, both the mixer  10  and conveyor  16  are preferably supported on a floor or other horizontal surface  24 . Conveyor  16  preferably is a non-powered conveyor having a plurality of rollers  26  supported by a frame  28 , and may include multiple sections similar or identical to the section shown in the figures to transport paint containers  14  towards and away from mixer  10 , as desired.  
         [0025]    Referring now also to FIGS. 2 a ,  2   b ,  2   c , and  2   d , the lifting attachment  12  preferably includes an arm weldment  30  having a pair of arms  32 ,  34 , and a cross brace  36  welded in an “H” form with two pairs of diagonal offsets  38 ,  40  and  42 ,  44 . The first pair of diagonal offsets  38 ,  40  are arranged in arms  32 ,  34 , respectively to conform to a sloping portion  46  of a front side  48  of mixer  10 . As used herein, “side” is to be understood to include the front surface of the mixer  10 , encompassing one or both of the sloping portion  46  and the vertically oriented parts of side  48 . The second pair of diagonal offsets  42 ,  44  reduce the width between a pair of manually graspable handles  50 ,  52 . Each of arms  32  and  34  are preferably formed of ⅛×1.0×1.0 inch cold rolled hollow steel tubing having a square cross section. The cross brace  36  is preferably formed of 16 gauge 0.50×1.00 inch cold rolled hollow steel tubing. The handles  50 ,  52  are preferably formed of ⅞ OD cylindrical steel tubing extend from proximal ends of arms  32  and  34 , respectively, and each has a conventional vinyl handle grip  57  received thereon. A pair of circular cross section pieces of ⅞ OD steel tubing form a pair of journals  58 ,  60  at distal ends of the arms  32 ,  34 , respectively, to allow the arm weldment  30  to pivot with respect to its mounting, to be described infra. A pair of cross section pieces of ⅞ OD steel tubing form projections  62 ,  64  to carry bumpers  65  which limit downward travel of the lifting attachment  12  after installation. A pair of 1 inch wide, 6 gauge steel angle flanges  66  each have an ear  70  formed at an angle of 122 degrees to carry a bumper  69  to limit upward travel of the lifting attachment  12 . Bumpers  65  and  69  are conventional, with bumpers  65  preferably having a shore durometer of 40 and bumpers  69  preferably having a shore durometer of 70. A pair of 1 inch wide, 6 gauge steel gussets  72  each have an aperture  74  therein to receive an end of a gas spring  76  to provide lifting support for lifting attachment  12 . Gas springs  76  are preferably rated at 80 lbs. and preferably have an operating range of 7.09 to 9.09 inches, with metal ball ends, each having a conventional threaded stud for attachment to the lifting attachment  12  using conventional washers and nuts.  
         [0026]    A 2 inch wide strap of nylon webbing  77  carries a hook  78  sized and shaped to receive bail handle  20  on bucket  14 . The hook  78  is preferably formed of 7 gauge steel. As may be seen most clearly in FIG. 2 c , webbing  77  preferably has a pair of loops  79  formed at each end of the strap by stitching the webbing to itself. One loop captures the hook  78 , and the other loop is received over a plate clamp  80 . The hook and webbing subassembly is preferably sized to enable the hook to release from the handle  20  when the lifting attachment is at or near the lowermost position. The hook and webbing subassembly is preferably secured to the cross brace  36  by the plate clamp  80 . As may be seen most clearly in FIGS. 2 c  and  2   d , conventional nuts are preferably used to secure bumpers  69  and plate clamp  80  to the lifting attachment  12 .  
         [0027]    Referring now most particularly to FIGS. 2 a  and  2   d , a plate  82  has a first pair of tabs  84  welded thereto for securing the gas springs  76 , and further has a second pair of tabs  86  welded to the plate  82  to support the arms  32 ,  34  at the journals  58 ,  60 . A pair of end walls  90 ,  92  are similarly welded to plate  82 . Each of the tabs  84 ,  86  and end walls  90 ,  92  are to be understood to include conventional projections received in notches (not shown) in plate  82  for maintaining the respective locations of these parts as they are welded together. End walls  90 ,  92  each have an aperture  94  aligned with an aperture  96  in tabs  86  to receive a conventional shoulder bolt  98  to form a pivot in each of journals  58 ,  60 . A decorative sheet metal cover  100  is preferably received over plate  82  and attached to end walls  90 ,  92  via studs  102  received in slotted tabs  104  welded to cover  100 . A conventional nut (not shown) is received over each of studs  102  and tightened to secure cover  100  to the lifting attachment assembly  12 .  
         [0028]    Referring now again most particularly to FIG. 2 a , a plurality of studs  106  preferably project downward from plate  82  and are used to secure the lifting attachment assembly  12  to the mixer  10  in a conventional manner.  
         [0029]    Referring now to FIGS. 3, 4,  5  and  6 , the operation of the lifting attachment will be explained. In FIG. 3, a paint bucket  14  is shown located on the conveyor  16  just prior to insertion into the mixer  10 . At this position, the arms  32 ,  34  of the lifting attachment  12  have been manually lowered and the hook  78  has been manually engaged with the bail handle  20  of the bucket  14 . In FIG. 4, the lifting attachment has been manually elevated with the aid of the gas springs  76 , by grasping at least one handle grip  57  and raising assembly  12  until the bucket clears a bucket receptacle  108  in the mixer  10 . It is to be understood that cross brace  36  will move laterally, as well as vertically, as the assembly  12  is elevated, moving bucket  14  closer to receptacle  108  as the assembly is elevated.  
         [0030]    In FIG. 4, the assembly  12  is nearly fully elevated, evidenced by close approach of bumpers  69  to plate  82 . At this time, the bucket  14  is positioned over the receptacle  108 , but is not aligned therewith. In FIG. 5, the bucket  14  is manually aligned with receptacle  108 , while attachment  12  is held in the fully elevated position. The lifting attachment is then lowered to the position shown in FIG. 6, using one or both handle grips  57 , while the bucket  14  slides into receptacle  108 , coming to rest as shown in FIG. 6. The lifting attachment  12  is shown in FIG. 6 positioned slightly above its lowermost position. This allows arms  32 ,  34  to be lowered to the lowermost position (not shown) at which time the bail handle  20  is released from hook  78 . The lifting attachment is then released from manual control, at which time it will return to the uppermost position similar to that shown in FIGS. 4 and 5, but with the bucket  14  remaining fully received in receptacle  108 . It is to be understood that the uppermost position will allow the lifting attachment to move (preferably about four inches in travel) higher than that shown in FIGS. 4 and 5, to enable the lifting attachment to rest in a position providing greater clearance to the mixer  10  than that shown in FIGS. 4 and 5. After the lifting attachment is elevated and released, door  22  is closed on mixer  10  and the paint is agitated by mixer  10 , after which the door  22  is opened and the process described above is repeated in reverse order to lift the bucket  14  from the mixer and return it to the conveyor  16 .  
         [0031]    In an alternative arrangement as shown in FIG. 7, a paint bucket  14  may be located on the floor  24  in front of mixer  10 , where the lifting attachment  12  may be used to assist raising the bucket  14  from the floor and into and out of the mixer  10 . The conveyor  16  is absent from this arrangement.  
         [0032]    Referring now most particularly to FIG. 8, an alternative embodiment of the present invention may be seen. In this embodiment, a single elongated handle  54  extends between the arms  32  and  34 . Handle  54  may have a vinyl grip thereon, similar to grip  57  for handles  50  and  52 .  
         [0033]    Referring now to FIG. 9, a still further alternative embodiment of the present invention utilizes a single arm  110  replacing and performing the functions of arms  32  and  34 . Arm  110  may be made of stronger material, if desired, or may be made of larger cross section material, to adequately support the increased loading for a single arm embodiment. An increased capacity spring  112 , preferably doubling the force of spring  76 , (but with the same stroke) may be used in this embodiment. Alternatively a pair of springs  112 ,  114  may be used with ratings the same as springs  76 . In this embodiment, a yoke or Y-shaped member  116  may be used to support webbing  77 , and a single handle  118  is preferable, with a vinyl grip, if desired.  
         [0034]    Referring now to FIGS. 10 and 11, it may be seen that the present invention may be practiced with free standing versions of the lifting apparatus. FIG. 10 shows an embodiment for a lifting apparatus  120  which is preferably not permanently attached to a paint mixer, but instead, is designed to have a paint mixer (such as the paint mixer  10 ) resting on it. A support structure or frame  122  includes a base member  124  and a pair of upright members  126 . Each upright member may be reinforced with a gusset  128 . Each upright member  126  has a lifting arm  130  pivotably attached thereto at pivot joints  131 , and a gas spring  132  or other device adapted to provide a lifting force is connected between the respective arm  130  and upright member  126 . A cross member  134  is secured between arms  130 , and carries a lifting strap  136  and hook  138 . It is to be understood that the lifting apparatus  120  may be the same or similar to lifting attachment  12 , except that it is not attached to the paint mixer, either directly or indirectly, but has its own support frame which may take various forms, provided that (in this embodiment) the support frame is free-standing with respect to the paint mixer. The operation of this embodiment is the same as that described for the previous embodiments. Furthermore, it is to be understood that the upright members may be located at the sides or even the front of the mixer, as alternatives to the embodiment shown in FIG. 10, where the upright members are shown in a position where they would be located at the back of the mixer.  
         [0035]    [0035]FIG. 10 a  is a simplified plan view of a “footprint” of the lifting apparatus of the present invention in the embodiments (e.g., shown in FIGS. 10 and 11) which are separate from the mixer. The base member  124  is shown as a frame of reference, with rear positions  172  shown to correspond to the positions of the upright members  126  of the embodiment shown in FIG. 10. Alternative locations for the upright members are at the sides of the paint mixer at locations  174 - 180 , or any where between locations  174  to  176  and  178  to  180 . As a still further alternative, the upright members may, if desired be located at the front of the mixer, as indicated at locations  182 . It is to be further understood that one or more upright members  126  may be located at the rear of the mixer between locations  172 , if desired, for example, to support a lifting attachment similar to that shown in FIG. 8 or  9 . Chain line  170  indicates a position for the mixer  10  with respect to the base member  124  of the lifting attachment  120 , with it being understood that clearance is provided either at the sides of mixer  10  or above mixer  10  for the gas springs  132  and their attachments to upright members  126 , which may be similar to tabs  84  (see FIGS. 2 a  and  2   d ).  
         [0036]    Referring now to FIG. 10 b , a simplified plan view of a “footprint” of a modified paint mixer  10 ′ may be seen. In this view, mixer  10 ′ may be “notched” or recessed at any of positions  184  to accommodate upright members  126 . The housing of the mixer may be inset as shown, or the housing may be “pushed out” in the regions intermediate “notches”  184  that are used to accommodate the upright members  126 . It is to be understood that, although notches  184  are shown adjacent corners, the notches may be located at alternative positions corresponding to such alternative positions described for the upright members with respect to FIG. 10 a.    
         [0037]    Referring now most particularly to FIG. 11, another version of the present invention shows a lifting apparatus  140  which, as shown, has its own support frame  142 . In an alternative embodiment (not shown) the sliding and pivoting arrangement of this embodiment may be attached to the paint mixer, if desired. Referring to FIG. 11, support frame  142  has a base member  144  and a pair of upright members  146  with gussets  148 . Lifting apparatus  140  has a pair of lifting arms  150  and a pair of gas springs or other lifting force devices  152 . A cross member  154  is secured between lifting arms  150  and supports a strap  156  carrying a hook  158 , as in earlier embodiments. Lifting apparatus  140  differs from the embodiments described above in that each of the arms  150  and lifting force devices  152  are pivotably attached to respective slide rails  160  which are slideably mounted on respective slide supports  162 . As shown the slide supports are mounted on the upright members  146 , but in an alternative version, the slide supports may be mounted to respective lateral sides of the paint mixer  10 . It is to be understood that the slide rails may be similar to drawer slides. Slide rails  160  are free to move by sliding along a predetermined length of slide supports  162 , with end stops  168  limiting travel of the rails or cars  160  at the respective ends of supports  162 .  
         [0038]    In operation, the lifting apparatus  140  may be stored by moving the slide rails  160  fully to the rear or distal end  164  of the slide supports  162 . To lift a paint container, the lifting apparatus  140  is preferably grasped by one or both handles  165  and moved forward by advancing slide rails  160  along slide supports  162  toward proximal end  166 . Stops  168  provided at each of ends  164 ,  166  of support  160  prevent separating the slide rail  160  from the slide support  162  during normal operation. Once the lifting apparatus  140  is advanced to the proximal end  166  of the slide supports  162 , the arms  150  are lowered by pulling down on handles  165  and the hook  158  is engaged with a paint container bail (not shown, but similar to either FIG. 3 or FIG. 7). The arms  150  are then raised by pushing or lifting up with handles  165 , with the assist of gas springs  152 , raising the paint container up vertically. Next the lifting apparatus  140  is pushed back away from the proximal end  166 , moving towards the distal end  164 , until the paint container is over the paint container receptacle  108  of the paint mixer  10 , similar to the relation of container  14  and receptacle  108  shown in FIG. 4. The paint container is then tipped or allowed to tip into alignment with the receptacle, as shown in FIG. 5, after which the arms  150  are lowered analogously to the position shown in FIG. 6, allowing the paint container to be fully received in the receptacle  108 . The process is reversed to remove the paint container from the receptacle using this embodiment. It is to be understood that the details of the pivoting connections to the arms and gas springs of FIGS. 10 and 11 may be the same as those shown and described for prior embodiments, as are the details of the strap and hook. It is to be further understood that the embodiments of FIGS. 10 and 11 may be used with or without a conveyor  16  in front of the paint mixer  10  in the practice of the invention using these embodiments. The embodiments of the lifting apparatus of FIG. 8 or  9  may be used with either of the support frames  122  or  142 , shown in FIGS. 10 and 11.  
         [0039]    Referring now to FIG. 12, an alternative support structure  200  for the lifting apparatus of the present invention includes a generally horizontal shelf-like member  202  to which any of the various embodiments of the lifting arms may be attached. Shelf  202  may be integrally formed with a pair of upright members  226 . Alternatively, one or more upright members may be separately formed and attached to shelf  202  using conventional fastening means. In the alternative, the upright members) may extend behind the paint mixer  10  and be connected to shelf  202  in a generally C-shaped configuration in which the shelf  202  is cantilevered from the upright member behind the mixer. The shelf  202  may rest on top of or in close clearance to the upper surface  204  of mixer  10 . Upright members  226  are preferably attached to a base member  224 .  
         [0040]    This invention is not to be taken as limited to all of the details thereof as modifications and variations thereof may be made without departing from the spirit or scope of the invention. For example and not by way of limitation, it is to be understood that the present invention is useful in lifting non-cylindrical, as well as cylindrical containers, into and out of mixers. By way of another example, and not by way of limitation, the spring member may be connected to the mixer instead of the support structure (even though the support structure is separate from the mixer) while still remaining within the scope of the present invention.