Methods for grinding of samples using a combination of rotational and linear motion

Abstract

Disclosed herein are devices, apparatuses, and methods for grinding of samples. A method includes securing a sample vial in a holder attached to a connecting linkage, the sample vial having a grinding media in the sample vial. The method includes rotating a crank that is operatively coupled to a proximal end of the connecting linkage at a proximal pivot point so that the proximal pivot point undergoes rotational motion. The method includes restricting a distal pivot point of the connecting linkage to a linear path, the distal pivot point near a distal end of the connecting linkage. A result being that the sample vial undergoes a combination of rotational and linear motion.

Claims

1. A method of manufacturing an apparatus for grinding of samples, the method comprising: operatively coupling a proximal pivot point of a connecting linkage to a crank pivot; securing the crank pivot to a crank at a position away from the central axis of the crank, the crank configured to impart rotational motion to the crank pivot and the crank pivot configured to rotate with respect to the connecting linkage or the crank; operatively coupling a distal pivot point of the connecting linkage to a slide pivot; securing the slide pivot to a sliding carriage, the sliding carriage configured to travel in a linear path and the slide pivot configured to rotate with respect to the connecting linkage or the sliding carriage; and attaching a holder to the connecting linkage, the holder configured to hold a sample vial such that rotation of the crank causes at least a portion of the holder to undergo a combination of rotational and linear motion.

2. The method of claim 1 wherein attaching the holder comprises attaching the holder to the connecting linkage between the proximal pivot point and the distal pivot point.

3. The method of claim 1 wherein attaching the holder comprises attaching the holder to the connecting linkage at a location that is more distal than the distal pivot point.

4. The method of claim 1 further comprising attaching a second holder to the connecting linkage, the second holder configured to hold a second sample vial such that rotation of the crank causes at least a portion of the second holder to undergo a combination of rotational and linear motion.

5. The method of claim 4 wherein the second holder is attached to the connecting linkage at a location that is more distal than the distal pivot point.

6. The method of claim 1 further comprising operatively coupling a motor to the crank.

7. The method of claim 1 further comprising securing a sample vial in the holder, the sample vial including a grinding media in the sample vial.

8. The method of claim 1 further comprising coupling the sliding carriage to a rail that is configured to restrict movement of the sliding carriage to the linear path.

9. The method of claim 1 further comprising: attaching a big pulley shaft to a big pulley and the crank such that rotation of the big pulley causes the crank to rotate by way of the big pulley shaft; and operatively coupling a drive belt to the big pulley and to a motor such that the motor causes the crank to rotate by way of the drive belt, the big pulley, and the big pulley shaft.

10. The method of claim 1 wherein the holder is configured to hold a plurality of sample vials.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further objects of the present invention together with additional features contributing thereto and advantages accruing therefrom will be apparent from the following description of the preferred embodiments of the invention which are shown in the accompanying drawing figures with like reference numerals indicating like components throughout wherein:

(2) FIG. 1 is blow-up illustration of the apparatus of the present invention showing the individual components thereof;

(3) FIG. 2 is an isometric view of the apparatus of the present invention; and

(4) FIGS. 3A, 3B, 3C, and 3D are a top view of the apparatus of the present invention at four different angular positions of the crank.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

(5) The components of the preferred embodiment of the apparatus of the present invention are shown in the blown-up illustration of FIG. 1. The individual components of the apparatus, with like reference numbers corresponding to the drawing of FIG. 1, are listed below in Table 3:

(6) TABLE-US-00003 TABLE 3 Ref No. Description 10 crank 11 crank pivot 12 sliding carriage/carriage/slide 13 slide pivot 14 rail 15 rail screws 16 linkage or connecting linkage 18 holder 20 sample vial or tube 21 frame top 22 ceramic bead 26 motor 28 drive belt 30 small pulley 32 big pulley 34 spacer 36 spacer 38 big pulley shaft 40 small pulley shaft 42 frame bottom 44 threaded adapter 46 frame screws 48 adapter screws 50 crank pivot bolt 52 slide pivot bolt 54 slide pivot nut 56 top frame screw 58 slide pivot carriage screw 60 slide pivot bearing 62 crank pivot bearing 100 reference line

(7) As illustrated in FIG. 1, a sample tube or vial (20) fits inside a holder (18). The holder (18) is attached to a connecting linkage or linkage (16). The linkage (16) sits on top of bearing pivots; the crank pivot (11) and slide pivot (13). The proximal end of the linkage (16) is attached to the crank pivot (11) via the top frame screws (56) while its distal end is attached to the slider pivot bearing (60) in the slider pivot (13) and is held in place via the slide pivot bolt (52) and slide pivot nut (54). The slide pivot (13) is connected to the sliding carriage or slide (12) via slide pivot carriage screws (58). The slide (12) sits on top of the rail (14) which is attached to the frame top (21) via slide screws (15). The crank pivot (11) is attached to the crank (10) via a crank pivot bearing (62). The crank (10) is connected to the big pulley (32) via the big pulley shaft (38). The big pulley (32) is driven or turned via a small pulley (30) through a drive belt (28). The small pulley (30) is connected to a small pulley shaft (40) which connects directly to the motor (26). The big pulley (32), big pulley shaft (38), drive belt (28) and the small pulley (30) are held in place between the frame top (21) and frame bottom (42) via frame screws (46) and spacers (34 and 36). The frame bottom (42) is attached to a threaded motor adapter (44) via adapter screws (48). The threaded motor adapter (44) allows for the attachment of the device of the present invention to the motor (26) which drives the small pulley (30) thereby moving the sample vial (20) in an elliptical path at a predetermined rate. In an alternate embodiment of the present invention, the sliding carriage (12) and rail (14) is made longer so that the holder (18) could be placed directly on the sliding carriage (12). The motion of the sample vial (20) is linear in this alternative embodiment.

(8) With reference now to FIG. 2, there is depicted an isometric view of a fully assembled apparatus of the present invention with the sample vial (20) in vial holder (18) which is in turn mounted on the connecting linkage (16), which has a pivot point at each end for connecting it to sliding carriage (12) at the distal end and crank 10 at the proximal end as shown in FIG. 2. Slide/carriage (12) slides on rail (14), which is fixed to the frame top (21) of the apparatus as discussed above. Motor (26) is linked to crank (10) via small pulley (30), drive belt (28), and big pulley (32). As crank (10) is driven to rotate by motor (26), its rotational motion is converted to linear motion as carriage (12) slides on rail (14). Since holder (18) is placed approximately halfway between the crank (10) and carriage (12), it experiences a combination of linear and rotational motion, resulting in an elliptical trajectory of sample vial/tube (20).

(9) The next figures, FIGS. 3A-D, show a top view of the apparatus at four angular positions of the cycle of crank (10), as it rotates in a counterclockwise direction. Also illustrated is a ceramic bead (22) that acts as pestle in grinding samples placed in the sample vial (20). Since the ceramic bead (22) has a high finite inertia, it will tend to stay in place at the level of reference line (100) while vial (20) surrounding it reciprocates in an elliptical path.

(10) Specifically, FIG. 3A depicts the ceramic bead (22) at midway the length of the vial (20), pressed against its left wall as it travels towards the top. FIG. 3B depicts the bead (22) impacting the top end of the tube. FIG. 3C depicts the ceramic bead (22) again midway the length of the tube, pressed against the right wall as it travels towards the bottom of the tube. Finally, the ceramic bead (22) impacts the bottom of the tube in FIG. 3D.

(11) Operation

Example 1

(12) 1. A sample to be ground or homogenized, if liquid is present, is inserted into a sample vial (20) that has preloaded hard grinding matrices [ceramic beads (22)] inside.

(13) 2. The vial (20) is sealed and inserted into the holder (18) of the device.

(14) 3. The device is turned on for a set period of time (usually 5 seconds or less, for example) at about 4,000 to 5,000 cycles per second to cause the sample to be ground or homogenized.

(15) 4. The tube is removed from the holder and unsealed to remove the ground sample for analysis.

Example 2

(16) 1. The user determines the optimal location for the holder on the connecting linkage.

(17) 2. The holder is attached onto the connecting linkage at the predetermined optimal location (distance from the crank pivot) to allow optimal grinding or homogenization of a sample.

(18) 3. A sample to be ground or homogenized, if liquid is present, is inserted into a sample vial (20) that has preloaded hard grinding matrices [ceramic beads (22)] inside.

(19) 4. The vial (20) is sealed and inserted into the holder (18) of the device.

(20) 5. The device is turned on for a set period of time (usually 5 seconds or less, for example) at about 4,000 to 5,000 cycles per second to cause the sample to be ground or homogenized.

(21) 6. The tube is removed from the holder and unsealed to remove the ground sample for analysis.

CONCLUDING STATEMENTS

(22) All patents, provisional applications, patent applications and other publications mentioned in this specification are herein incorporated by reference.

(23) While this invention has been described in detail with reference to certain preferred embodiments, it should be appreciated that the present invention is not limited to those precise embodiments. Rather, in view of the present disclosure, which describes the current best mode for practicing the invention, many modifications and variations would present themselves to those of skill in the art without departing from the scope and spirit of this invention. The scope of the invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

(24) Furthermore, those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.