Patent Publication Number: US-9895670-B2

Title: Head for a mixing apparatus

Description:
BACKGROUND 
     The present invention relates to a mixing apparatus such as a centrifuge or shaker. In particular, the invention relates to a head that can be coupled to a mixing apparatus and configured to receive either a microplate or test tubes. 
     SUMMARY 
     In one embodiment, the invention provides a head that can be coupled with a mixing apparatus. The head includes a body that defines a longitudinal axis and includes a plurality of sides that are deformable and are spaced to permit frictional engagement of a microplate between them. The head also includes at least one vertical channel that is configured to removably secure a test tube to the body so that a longitudinal axis of the test tube orients in a direction perpendicular to the longitudinal axis of the body, and at least one horizontal channel that is configured to removably secure a test tube to the body so that a longitudinal axis of the test tube orients in a direction parallel to an axis of the horizontal channel. 
     In another embodiment, the invention provides a head that can be coupled with a mixing apparatus. The head includes a body that defines a longitudinal axis and a first side, a second side, a third side, and a fourth side that each includes a projection. The body includes a central member for supporting a microplate between the sides. The head includes a first vertical channel, a second vertical channel, a third vertical channel, and a fourth vertical channel. The first vertical channel is configured to removably secure a first test tube to the body in a direction so that a longitudinal axis of the test tube is perpendicular to the longitudinal axis of the body. The second vertical channel is configured to removably secure a second test tube to the body in a direction so that a longitudinal axis of the test tube is perpendicular to the longitudinal axis of the body. The first horizontal channel is configured to removably secure a third test tube to the body in a direction so that a longitudinal axis of the test tube is parallel to the longitudinal axis of the body. The second horizontal channel configured to removably secure a fourth test tube to the body in a direction so that a longitudinal axis of the test tube is perpendicular to the longitudinal axis of the body. The first test tube, the second test tube, the third test tube, and the fourth test tube can be coupled to the body at the same time. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a mixing apparatus with a head having a plurality of test tubes secured thereto according to a first embodiment of the invention. 
         FIG. 1 a    is a perspective view of the mixing apparatus with the head of  FIG. 1  having a microplate secured thereto. 
         FIG. 2  is an exploded view of the mixing apparatus and head of  FIG. 1 . 
         FIG. 3  is a perspective view of the head of  FIG. 1 . 
         FIG. 4  is a top plan view of the head of  FIG. 1 . 
         FIG. 5  is a bottom plan view of the head of  FIG. 1 . 
         FIG. 6  is a first side elevation view of the head of  FIG. 1 . 
         FIG. 7  is a second side elevation view of the head of  FIG. 1 . 
         FIG. 8  is a front elevation view of the head of  FIG. 1 . 
         FIG. 9  is a rear elevation view of the head of  FIG. 1 . 
         FIG. 10  is a first cross-sectional view of the head of  FIG. 1  along line  10 - 10  of  FIG. 3 . 
         FIG. 11  is a second cross-sectional view of the head of  FIG. 1  along line  11 - 11  of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
       FIGS. 1-11  illustrate a head  10  that can be coupled to a mixing apparatus  14  (e.g., a centrifuge, shaker, etc.). The mixing apparatus  14  includes a housing  18  that encloses a motor  22 . A rotor post sub-assembly  20  ( FIG. 3 ) is located in the housing  18 . The housing  18  includes a three-position switch or button  26  that actuates the motor  22  and an actuator or dial  28  that varies the speed of the motor  22 . The three-positions of the switch  26  include “off,” “on,” and “intermittently on.” In the illustrated embodiment, the housing  18  includes a power supply that provides alternating current (AC) power via a corded plug  30  electrically coupled to a wall outlet. In other embodiments, the power supply may be a battery pack or any number of suitable powering options, however. 
     Further with respect to  FIGS. 2 and 3 , the head  10  includes a body  50  that defines a longitudinal axis A and includes a first side  54 , an opposite second side  58 , a third or front side  62 , and a fourth or rear side  66  opposite front side  62 . A coupler  70  ( FIGS. 5-11 ) extends from the body  50  and secures the head  10  to the housing  18  of the mixing apparatus  14 . The body  50  defines one or more horizontal channels  80 ,  84 ,  88 ,  92  for holding test tubes. In the illustrated embodiment, the first horizontal  80  channel is defined in part by the first side  54 , the second horizontal channel  84  is defined in part by the second side  58 , the third horizontal channel  88  is defined in part by the third side  62 , and the fourth horizontal channel  92  is defined in part by the fourth side  66 . Each of the first, the second, the third, and the fourth sides  54 ,  58 ,  62 ,  66  is spaced apart from a central member or median  100  by the first, the second, the third, and the fourth horizontal channels  80 ,  84 ,  88 ,  92 , respectively. Therefore, each of the first, the second, the third, and the fourth channels  80 ,  84 ,  88 ,  92  is also defined in part by the central member  100 . Each of the first, the second, the third, and the fourth sides  54 ,  58 ,  62 ,  66  includes a projection or lip  104  that protrudes towards the central member  100 . In the illustrated embodiment, the first and the second channels  80 ,  84  are each further defined by a first rib  108  and an opposing second rib  112  that extend from the third and the fourth sides  62 ,  66 , respectively. The first and the second ribs  108 ,  112  are positioned at distal ends of the first and the second channels  80 ,  84 . 
     As illustrated in  FIGS. 1-4 , the first and the second channels  80 ,  84  are spaced apart from one another by the central member  100 , and they longitudinally extend parallel to the longitudinal A axis. The third and the fourth channels  88 ,  92  are spaced apart from one another by the central member  100  and longitudinally extend perpendicular to the longitudinal axis A. As illustrated herein, the first, the second, the third, and the fourth sides  54 ,  58 ,  62 ,  66  are substantially arcuately shaped in cross section and are elastically deformable such that each of the first, the second, the third, and the fourth horizontal channels  80 ,  84 ,  88 ,  92  can removably receive and secure a test tube with a snap-fit engagement. The projection  104  on each of the first, the second, the third and the fourth sides  54 ,  58 ,  62 ,  66  engages and maintains the test tube within the respective channel  80 ,  84 ,  88 ,  92 . The first and the second channels  80 ,  84  have a diameter D1 and are configured to removably receive and secure 50 ml test tubes  96  ( FIG. 11 ). The third and the fourth channels  88 ,  92  have a diameter D2 and are configured to removably receive and secure 15 ml test tubes  98  ( FIG. 10 ). The first and the second diameters D1, D2 are different from one another and could be differently sized to engage different size test tubes. 
     A bottom  120  of each of the first and the second sides  54 ,  58  includes a plurality of test tube apertures  130  that are configured to hold test tubes so that their longitudinal axes orient in a direction parallel to an axis B ( FIG. 2 ) and in a direction that is perpendicular to the longitudinal axis A. Each of the apertures  130  includes a wall  134  ( FIGS. 2, 3, 5, 7 ) that is positioned adjacent to and concentric therewith. The walls  134  project from the body  50  in a direction parallel with the axis B. In the illustrated embodiment, the walls  134  are substantially uniform in height, but in other embodiments the walls have varying heights. The apertures  130  and walls  134  define vertical channels  138  that have a diameter D3 ( FIG. 4 ) and are configured to snugly and removably receive and secure 1 ml test tubes (not shown). The third diameter D3 may be different from the first and the second diameters D1, D2. Again, diameter D3 depends on the size of the test tubes to be held in them. 
     The central member  100  includes a top surface  200  having a non-uniform contour. In other words, the top surface  200  has raised regions  204 ,  208 ,  212  and depressed regions  216 ,  220 . The central member  100  also includes a deformable pad  224  that is flush with one of the raised portions  208  of the top surface  200 . The pad  224  is constructed from an elastomeric material such as polyurethane foam. 
     The central member  100  includes a plurality of test tube apertures  250 ,  254  that are also configured to hold test tubes so that their longitudinal axes orient in a direction parallel to the axis B and therefore, perpendicular to the longitudinal axis A. As illustrated  FIG. 3 , the central member  100  includes a pair of first rows  258 , which contain the apertures  250 , and a pair of second rows  262 , which contain the apertures  254 , with one of each of the rows  258 ,  262  on opposite sides of the pad  224 . 
     The apertures  250  of the first row  258  each include an adjacent, concentric wall  270  that projects from the body  50  in a direction parallel to the longitudinal the axis B. The apertures  250  and the walls  270  each define a vertical channel  274  ( FIG. 10 ) that extends along the axis B (e.g., perpendicular to the longitudinal axis A) and have a diameter ( FIG. 4 ). The vertical channels  274  are configured to removably receive and frictionally engage 1.5 ml test tubes  278 . The fourth diameter D4 is different from the first, the second, and, the third diameters D1, D2, D3. In the illustrated embodiment, the walls  270  of each aperture  250  have varying heights due to the different positions of each aperture  250  along the contoured top surface  200 . The heights are selected so that top surfaces of all of the walls  270  are co-planar. 
     The apertures  254  of the second row  262  each include an adjacent, concentric wall  300  that projects from the body  50  in a direction parallel to the longitudinal the axis B. The walls  300  of the apertures  254  in the second row  262  each include a first wall section  304  that is disposed above the top surface  200  of the central member  100  ( FIGS. 3, 4, and 10 ) and a second wall section  308  that is disposed below a bottom surface  312  of the central member  100  ( FIGS. 5 and 10 ). The first wall section  304  is continuous, while the second wall section  308  is discontinuous, thereby defining converging projections  320  ( FIGS. 8-10 ). The projections  320  are biased towards a central of the respective aperture  254  and are also elastically deformable. The apertures  254  of the second rows  262  and the walls  300  define vertical channels  324  that have a diameter D5 of and are configured to removably receive and frictionally engage 2 ml test tubes  328  ( FIG. 4 ). The fifth diameter D5 is different from the first, the second, the third, and the fourth diameters D1, D2, D3, D4. In the illustrated embodiment, the walls  300  of each aperture  254  have varying heights due to the different position of each aperture  254  along the contoured top surface  200 . The heights are selected so that top surfaces of the walls  300  are all co-planar. The converging projections  320  ensure that the test tubes are securely retained within the vertical channels  324 . 
     The body  50  is also configured to removably receive and frictionally engage a microplate  350 . In particular, the first, the second, the third, and the fourth sides  54 ,  58 ,  62 ,  66  are elastically deformable and receive the microplate therebetween. The projections  104  on each of the first, the second, the third and the fourth sides  54 ,  58 ,  62 ,  66  engage and maintain the position of the microplate  350  relative to the body  50  and secure the microplate  350  with a snap-fit engagement. An auxiliary coupling mechanism (not shown) may additionally be used to secure the microplate  350  relative to the body  50 . The auxiliary mechanism may be an elastic retention bands (not shown) that are pre-attached to the mixing head, for example. 
     To assemble the head and housing, the head  10  is secured (i.e., by a snap fit engagement or fastening system) to the housing  18  of the mixing apparatus  14 . The rotor post sub-assembly  20  underlies the pad  224  and connects to a switch (not shown) in the housing for activating the motor  22 . Once assembled, either the microplate  350  or one or more test tubes may be secured to the head  10 . For example, the user can couple the microplate  350  to the head  10  between the first, the second, the third, and the fourth sides  54 ,  58 ,  62 ,  66  using one or more of the projections  104  on those sides. Alternatively, the user may slide one or more test tubes into one or more of the horizontal channels  80 ,  84 ,  88 ,  92  and one or more of the vertical channels  138 ,  274 ,  324 . The head  10  is configured to receive several sizes of test tubes at the same time. In other words, the head  10  can receive, for example, a 50 ml test tube in one of the horizontal channels  80 ,  84  and a 15 ml test tube in another of the horizontal channels  88 ,  92  at the same time. Also, the head  10  can receive, for example, a 1 ml test tube in one of the vertical channels  138 , a 1.5 ml test tube in another of the vertical channels  274 , and a 2 ml test tube in yet a third of the vertical channels  324 , all at the same time. Similarly, the head  10  can receive a test tube in one or more of the horizontal channels  80 ,  84 ,  88 ,  92  and a test tube in one or more of the vertical channels  138 ,  274 ,  324  at the same time. Once appropriately positioned, the motor  22  is actuated by the switch  26 . Actuation of the motor  22  moves (e.g., translates, oscillates, or translates and oscillates) the head  10  relative to housing  18  to agitate the contents of the microplate  350  or of the one or more test tubes. 
     The head  10  is depressible relative to the housing  18  to manually actuate the motor  22 , if switch  26  is in the intermittent position. In particular, when a manual force is applied to the pad  224 , the pad  224  will move toward the sub-assembly  20  in the housing  18 , thereby actuating the motor  22 . Removal of the force causes the motor  22  to stop. Therefore, a user can, for example, press a bottom, closed end of a test tube into the pad  224  and actuate the motor  22 . By holding the test tube against pad  224  while the motor is actuated, the contents of the test tube are agitated. Removing the test tube from the pad  224  shuts the motor off. If the switch  26  is at the “intermittent” position and the speed dial  28  is set to maximum, a vortex motion will be created within the contents of the test tubes held in or pressed against the head. 
     Various features and advantages of the invention are set forth in the following claims.