Patent Publication Number: US-6712498-B1

Title: Straddle mixer

Description:
FIELD OF THE INVENTION 
     The present invention relates to an apparatus for blending coating materials and particularly a straddle mixer that is adjustable to suit paint drums of different sizes and fastenable to the paint drum, and has a detachable blender to facilitate washing and cleaning. 
     BACKGROUND OF THE INVENTION 
     A conventional paint or coating material mixer such as the one shown in FIG. 1 mainly includes a small driving motor  1  which has a spindle extended to form a center stem  2 . The center stem  2  has a lower end coupled with one or more blades  3  which may be driven to rotate by the motor  1 . The top end and one side of the motor  1  have respectively a handle ring  4  and a handgrip  5  to enable an user to grasp with two hands for placing the lower end of the center stem  2  into a paint drum to mix the paint contained therein with the rotating blades  3  when the motor  1  is activated. In practical use, paints and coating materials usually have a relatively high viscosity, and a painter usually has to estimate in advance the required paint for a given painting area, and blends the required paint of a desired color in one batch to avoid blending in different batches and result in different painting color hues. However, the conventional paint mixer mentioned above is suitable only for blending a small amount of paint. This is mainly caused by the constraints of human labor and the sizes of the handle ring and handgrip. As the motor is made from metal and is quite heavy, and the paint has a great viscosity, it is difficult for a painter to grasp and hold the paint mixer for a long period of time or to blend a large amount of paint. This is a problem pending to be resolved. 
     SUMMARY OF THE INVENTION 
     Therefore the primary object of the invention is to provide a straddle mixer that has a larger driving motor mounted onto a horizontal base dock. There is a clamp apparatus with an adjustable clamping width located beneath the base dock for fastening to the upper rim of a paint drum. The clamp apparatus also enables a blender to move to thoroughly blend the paint. 
     Another object of the invention is to provide a chuck below the motor that is movable to grip or detach the blender so that the paint drum may be cleaned easily and the blender may be detached or replaced conveniently. 
    
    
     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional mixer. 
     FIG. 2 is a perspective view of an embodiment of the invention in use. 
     FIG. 3 is an exploded view of an embodiment of the invention. 
     FIG. 4 is a cross section taken along line  4 — 4  in FIG.  2 . 
     FIG. 5 is a fragmentary cross section of an embodiment of a chuck of the invention. 
     FIG. 6A is a schematic view of an embodiment of the invention in an operating condition. 
     FIG. 6B is a schematic view of an embodiment of the invention in another operating condition. 
     FIG. 7 a perspective view of another embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 2 and 3, the straddle mixer of the invention includes a vertical air motor  10  and a speed reducer  11  connecting to a lower end of the motor  10 . Below the speed reducer  11 , there is a hollow coupling barrel  12  housed in an opening formed on a horizontal base dock  13 . The hollow coupling barrel  12  has a peripheral flange fastened to the base dock  13  around the opening. The upper end of the coupling barrel  12  has a cavity  121  directing downwards to house the lower section of the speed reducer  11 . The coupling barrel  12  has a center hole to allow a spindle  111  that fastened to the lower end of the speed reducer  11  to pass through. There is a bearing  112  located between the spindle  111  and the coupling barrel  12 . The spindle  111  has a lower end fastened to a round chuck  14 . Referring to FIG. 5, the chuck  14  has three jaws  141  located at the lower end. The jaws  141  are retractable synchronously towards the center to grip the stem  151  of a blender  15 . 
     The stem  151  of the blender  15  has two blade units  152  mounted onto a lower end thereof for blending paint or coating materials. 
     The horizontal base dock  13  has two sleeves  16  located respectively at a front side and a rear side on a lower section thereof to couple with a rod  161 . Each sleeve  16  is engaged with a set screw  162  from the outer wall for fastening the rod  161  securely in the sleeve  16 . There is a clamp apparatus mounting onto the two rods  161 . The clamp apparatus includes a stationary plank  163  located at one end of the rods  161  that has a first groove  164  formed on an inner wall surface to engage with a top peripheral rim  21  of a paint drum  20 . The clamp apparatus has a movable plank  165  movably run through by another end of the rods  161 . Referring to FIG. 4, the movable plank  165  includes a front plank  165 A and a rear plank  165 B that are fastened together by screws. The front plank  165 A has an inner wall surface with a second groove  166  formed thereon. The rear plank  165 B has a fish eye cavity  167  formed in the axial direction. There is an anchor block  17  fastened to anther end of the rods  161 . There is a screw rod  18  coupling with a middle screw hole  171  formed on the anchor block  17 . The screw rod  18  has one end formed a retain flange  181  which is greater than the outer diameter of the screw rod  18  and another end running through the fish eye cavity  167  of the rear plank  165 B to fasten to a wheel  182 . Turning the wheel  182 , the screw rod  18  may be driven to rotate. Then the retain flange  181  at one end of the screw rod  18  may push the front plank  165 A moving towards the stationary plank  163  or drive the rear plank  165 B moving the entire movable plank  165  towards the anchor block  17  as shown in FIGS. 6A and 6B. 
     By means of the construction set forth above, when in use, first select a suitable blender  15  to be gripped by jaws  141  of the chuck  14 . Fasten the jaws  141  tightly to enable the stem  151  of the blender  15  be fastened securely below the horizontal base dock  13 . The movable plank  165  of the invention may be adjusted to the left or right side to suit the size of the paint drum  20 . For operation, place the invention on the top of the paint drum  20  in a straddle manner with the first groove  164  of the stationary plank  163  located at one end of the base dock  13  to wedge and engage with the top peripheral rim  21  of the paint drum  20 , then turn the wheel  182  to move the movable plank  165  towards the top peripheral rim  21  at another side of the paint drum  20  to enable the second groove  166  on the movable plank  165  to engage tightly with the top peripheral rim  21  at another side. Then move the blade units  152  at the lower end of the blender  15  into the paint drum  20 . The set screw  162  on the sleeve  16  may be loosened to adjust the left and right position of the horizontal base dock  13 , and be fastened again to station the blender  15  at a desired location in the paint drum  20 . Then the motor of a greater power may be activated to blend a large amount of paint or coating materials. Thus the invention can save human labor and overcome the problem of hand gripping limitation that occurs to conventional mixers. The invention also can blend a large amount of paint and resolve the problem of blending paint in multiple batches that result in different color hues. 
     In addition, the three jaws  141  of the chuck  14  can grip or loosen the blender. Therefore different types of blenders  15  with different number and size of stems  153  and blade units  152  (referring to FIG. 7) may be selected and coupled with the chuck  14  to meet various blending requirements effectively. This is especially useful for blending a large amount of paint or coating materials. 
     When there is a need to wash or clean the blender  15  or the paint drum  20 , the jaws  141  of the chuck  14  may be loosened to remove the blender  15 . The wheel  182  may also be turned to move the movable plank  165  outwards so that clamp apparatus may be removed from the paint drum  20 . All this makes washing and cleaning of the blender  15  and the paint drum  20  much easier.