Improved sample grinder

Abstract

The bead mill homogenizer (100) includes: a shaft having a body (30) extending along a main axis (32) and a distal connector (34) extending along a connecting axis (36) at an acute angle to the main axis (32); a motor (20) configured to rotate the shaft about the main axis (32); a head (60) rotatably connected to the distal connector (34) of the shaft; and a clamp (62, 64, 66) fixed to the head (60) and configured to fix a sample vial holder (70, 170, 270, 370, 470), the sample vial holder being configured to hold one or more sample vials therein, wherein rotational movement of the shaft about the main axis (32) is converted into movement of the head (60) in a direction perpendicular to the main axis (32). A sample vial holder (470) is also provided, the sample vial holder having an internal channel network defined within the housing, through which a coolant can pass to control the temperature of a vial disposed therein.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62 / 760,457, filed on November 13, 2018, the disclosure of which is hereby incorporated herein by reference. Background Art

[0003] The present application relates to a mechanical disruption process for relatively small sample volumes and an improved, more robust system for more efficient disruption.

[0004] In the sample preparation market, mechanical disruption is a common way to break, lyse or grind (crush) samples for further testing. Typical goals of these processes include one or more of the following: particle size reduction; facilitating the extraction (lysis) of DNA and RNA, proteins, pesticides and other contaminants (i.e. metals or RoHS materials) by disrupting cells; and homogenization or mixing of samples.

[0005] The "bead mill" system "grinds" and crushes the sample and breaks it using steel balls or other media (such as ceramic or glass). In this process, the sample is shaken in some form. Traditional "bead mill" instruments break / crack the sample by crushing or "grinding" the sample between the top and bottom of the vial during the process or between the steel balls or other media added to the vial. Depending on the design of the instrument, some samples may be cracked between the media due to the media pressing against the top and bottom of the sample container and the media pressing against the side walls of the sample container. The speed of such bead mill systems is usually in the range of 500 to 4000 revolutions per minute. This is equivalent to 1000 to 8000 oscillations per minute. The speed range of large titer plate crushing devices is 500 to 1750 revolutions per minute. The motion in the bead mill product is a vertical motion or horizontal motion that forces the ball media to move back and forth within the vertical height or width of the vial, or a combined motion that swirls the sample and media back and forth in the sample vial.

[0006] The choice of bead mill to use depends on the sample vial size, sample size, and sample characteristics. Tough samples such as seeds, rice, corn kernels, organs, and fibrous plants generally require larger, heavier beads / media, while samples such as bacteria, yeast, and fungi use smaller beads / media. Samples such as leaves, soil, and plant material generally require some investigation into the optimal device and media size.

[0007] Some instruments include a means for keeping samples cool during operation. This involves contacting the vial or titration plate with a cooled cryoblock prior to use. Some disadvantages associated with cryoblocks are that they cannot maintain a specific temperature during use because they act as a heat sink, and their initial temperature is often difficult to adjust and is sometimes too cold for some samples. Improvements are needed.

[0008] Although bead beaters have become an important device for sample grinding, further improvements are desired. Summary of the invention

[0009] A first aspect of the present invention is a bead mill homogenizer comprising: a shaft having a main body extending along a main axis and a distal connector extending along a connecting axis at an acute angle to the main axis; a motor configured to rotate the shaft around the main axis; a head rotatably connected to the distal connector of the shaft; and a clamp fixed to the head and configured to fix a sample vial holder, the sample vial holder being configured to hold one or more sample vials therein, wherein rotational motion of the shaft around the main axis is converted into motion of the head in a direction perpendicular to the main axis.

[0010] In other embodiments according to the first aspect, the body of the shaft may intersect the distal connector at a bend or elbow of the shaft. The distal connector may be disposed within an inner cavity defined by the head. The rotational motion of the shaft about the main axis may also be converted into an oscillatory motion of the head, such that the end of the head closest to the body of the shaft pivots toward and away from the body of the shaft. The fixture may include a clamping base in which a sample vial holder may be disposed, a clamping arm connected to the clamping base, and a clamping latch connected to the clamping base, wherein engagement of the clamping latch with the clamping arm secures the sample vial holder to the head. The clamping arm may be pivotally connected to one side of the clamping base, and the clamping latch is pivotally connected to the other side of the clamping base.

[0011] The fixture can be configured to receive a plurality of differently configured sample vial holders. The bead mill homogenizer can also include a plurality of differently configured sample vial holders. The differently configured sample vial holders can include at least two of the following: a first sample vial holder having only one hole for holding a vial; a second sample vial holder having only two holes for holding two vials; a third sample vial holder having only three holes for holding three vials; a fourth sample vial holder having only four holes for holding four vials; a fifth sample vial holder having only five holes for holding five vials; a sixth sample vial holder having only six holes for holding six vials; and a seventh sample vial holder having at least one hole for holding a vial and an internal channel network through which a coolant can pass to control the temperature of a vial disposed therein.

[0012] The bead mill homogenizer may also include a sample vial holder defining an internal channel network, through which a coolant may pass to control the temperature of a vial disposed therein. The sample vial holder may include a housing defining a cavity, the cavity being configured to at least partially enclose the vial, and the internal channel network may include an inlet channel, an internal channel adjacent to the cavity, and an outlet channel connected for coolant flow. The sample vial holder may include a housing and a holder plug, the housing defining a cavity, the cavity being configured to at least partially enclose the vial, the holder plug being disposed in the cavity to seal the cavity relative to the external environment, and the holder plug defining a cavity in which the vial may be placed. An empty cavity may be defined between the inner surface of the cavity of the housing and the outer surface of the holder plug. The internal channel network may include an inlet channel leading to the empty cavity and an outlet channel leaving the empty cavity, so that the inlet channel, the empty cavity, and the outlet channel define a passage through which a coolant may pass to control the temperature of a vial disposed in the holder plug.

[0013] The bead mill homogenizer may also include a first bearing assembly disposed around the shaft between the head and the motor. The head may also include a second bearing assembly disposed around the distal connector of the shaft. The motor may include a third bearing assembly.

[0014] The bead mill homogenizer may also include: a speed measuring disk rotatably connected to the body of the shaft, wherein the speed measuring disk defines a plurality of holes on its circumferential periphery; and an optical interrupter having two plates between which the IR signal passes, wherein the circumferential periphery of the speed measuring disk is disposed between the plates of the optical interrupter so that the holes cross the path of the IR signal. The bead mill homogenizer may also include: a processor that receives a signal corresponding to the interruption of the IR signal and is configured to use the signal to calculate the rotational speed of the shaft.

[0015] The sample vial holder may have an end wall that covers at least 50% of the area of ​​each end face of the vial, respectively. Rotational movement of the shaft about the main axis may rotate the distal connector so that the distal connector scans an imaginary conical surface. Rotational movement of the shaft about the main axis may rotate the head along a circular path on the imaginary conical surface.

[0016] A second aspect of the present invention is a sample vial holder for use with a bead mill homogenizer, comprising a housing defining a cavity configured to at least partially enclose a vial; and an internal channel network defined within the housing through which a coolant may pass to control the temperature of a vial disposed therein.

[0017] In other embodiments according to the second aspect, the internal channel network may include an inlet channel, an internal channel adjacent to the cavity, and an outlet channel connected for coolant flow. The sample vial holder may also include: a holder plug disposed in the cavity to seal the cavity relative to the external environment, the holder plug defining a cavity in which the vial can be placed. An empty cavity can be defined between the inner surface of the cavity of the housing and the outer surface of the holder plug. The internal channel network may include an inlet channel leading to the empty cavity and an outlet channel leaving the empty cavity, so that the inlet channel, the empty cavity, and the outlet channel define a passage through which the coolant can pass to control the temperature of the vial disposed in the holder plug. The sample vial holder may also include a protective cover configured to cover the open end of the cavity.

[0018] A third aspect of the present invention is a bead mill homogenizer comprising: a shaft having a main body extending along a main axis and a distal connector extending along a connecting axis at an acute angle to the main axis; a motor configured to rotate the shaft around the axis of the shaft and comprising a first bearing assembly; a head rotatably connected to the distal connector of the shaft, wherein the head comprises a second bearing assembly arranged around the distal connector of the shaft; a sample vial holder fixed to the head; and a third bearing assembly arranged around the shaft between the head and the motor.

[0019] Other aspects of the invention relate to methods of using the above aspects, comprising operating the motor to rotate the shaft about its primary axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a cross-sectional side view of a bead mill homogenizer according to the present invention.

[0021] Figure 2 yes Figure 1 A perspective view of a bead mill is shown.

[0022] Figures 3 to 5 is with Figure 1 A perspective view of a bead mill shown in FIG. 1 used in conjunction with different sample vial sizes having different sample holders for each vial type.

[0023] Figure 6 yes Figure 1 An exploded view of the sample vial holder of the bead beater is shown.

[0024] Figure 7 yes Figure 1 A perspective view of the speed control mechanism in a bead mill is shown.

[0025] Figure 8 is a perspective view of another clamping mechanism according to the present invention.

[0026] 9A to 9CPerspective views of three examples of sample boxes or vial holders are shown.

[0027] FIG. 10A to FIG. 10F They are respectively an assembly perspective view, an exploded perspective view, a top view, a side view, a front view and a rear view of another sample vial holder according to the present invention.

[0028] FIG. 11A to FIG. 11B 1 and 2 are respectively an assembled perspective view and an exploded perspective view of another sample vial holder according to the present invention.

[0029] Fig.12 is a perspective view of a sample vial holder according to the present invention.

[0030] FIG. 13A to FIG. 13B They are Fig.12 Bottom view and cross-sectional side view of the sample vial holder are shown. DETAILED DESCRIPTION

[0031] like Figures 1 to 7 As shown, the improved bead mill homogenizer includes a housing in which a motor 20 is arranged. The motor 20 is connected to an output shaft that extends through the housing 10 into a sample chamber 12, which is shielded by a removable sample shield 14 that can be locked in place during use. The motor 20 is anchored to a damping plate 40, which is connected to the bottom and sides of the housing 10 by a damping device 42 (such as a spring and a shock absorber). Shock absorbers are provided at each end of the instrument to reduce vibration effects. The housing 10 includes several pads 16 at its bottom to further damp the vibrations generated by using the bead mill 100 on the outer surface. The bead mill 100 also allows the instrument to be used as a mixer, with mixing speeds of 750rpm and 1000rpm, and homogenizing or grinding speeds of 2000rpm, 3000rpm and 4000rpm. Other speeds for either use are also contemplated.

[0032] The shaft 30 rotates about its central longitudinal axis 32 via a bearing. A pin or screw is fixedly connected to the distal end of the shaft 30. The axis 36 of the pin 34 is at an acute angle to the axis of the shaft 30 so that the entire shaft / pin structure includes a bend or elbow, so that rotation of the shaft 30 causes the pin 34 to move around or scan out an imaginary conical surface. The pin 34 is disposed within an inner cavity of the sample connector or head so that the pin 34 can rotate within the inner cavity during use. The sample connector 60 is block-shaped and has a flat surface facing the motor 20. The flat surface is not perpendicular or orthogonal to the axis 32. The sample connector 60 is connected to the housing 10 via springs on each side of the shaft 30 and, for example, by anchors 63 and anchors 65 on each side of the sample connector 60, such as Figure 3As shown. In this way, when the shaft 30 rotates around its central axis, the pin 34 rotates eccentrically as described above and causes the inner cavity in the sample connector 60 to move around the same imaginary conical surface, but does not rotate completely around the axis of the pin 34. During this movement, some lateral oscillations damped by the spring occur. That is, the sample connector 60 has an upward surface that remains generally upward throughout this movement. The spring anchors the sample connector 60 to the housing 10 to further guide its oscillatory motion. The length of the shaft 30, the angle and position of the sample connector 60, and the strength of the spring are configured to produce a more violent stirring process so as to grind the sample more efficiently.

[0033] The rotational movement of the shaft 30 about the axis causes the sample connector 60 to move about the circle of an imaginary cone, thereby moving the sample connector 60 in all directions perpendicular to the axis. This also causes the head to rock, pivot or oscillate toward and away from the body of the shaft 30 (i.e., where the motor 20 is located). For example, while Figure 1 The sample connector 60 is depicted tilted so that it is angled from the lower left to the upper right of the image, but once the pin 34 is rotated to its highest position, the sample connector 60 will be angled from the upper left to the lower right of the image. Since the sample connector 60 itself does not rotate about an axis, this creates a seesaw or oscillating motion about an axis that is generally horizontal and perpendicular to the axis. As the sample connector 60 is operated, the horizontal axis about which the sample connector 60 oscillates moves back and forth slightly, and its motion is damped by the spring that helps secure the sample connector 60 to the housing 10.

[0034] The application uses small metal balls, ceramic balls or other glass media to "grind" or crush samples. After the ball is inserted into a sample container or a titration plate of acceptable size, due to the rotation of the horizontally oriented shaft 30, the sample moves up and down vertically at high speed, which causes the ball to decompose the material in the sample container in their movement. The vial containing a single sample and one or more balls or multiple sample vials each having their own medium selection shake with complex motion, which combines reciprocating swing and short lateral motion, and each end of the vial moves along an 8-shaped path. This motion produces powerful G-forces in the vial to crush the toughest rocks, slag and ceramics. The beads or balls in the vial will not bottom out for a long time at either end of the vial before being thrown in different directions. Bead milling technology can be used with balls or other media ranging in size from less than 100 microns to as large as 25 millimeters. The medium can be such as steel, plastic, zirconium, garnet, glass and many other materials. While any media can be used in a bead mill, the choice of beads depends on the vial size, the size and hardness of the sample to be crushed, the sensitivity of the sample to heat, media contamination concerns, and many other factors.

[0035] The bead mill 100 contains several bearings, including two dual bearing assemblies. The first bearing assembly is designed to protect the bead mill 100 from excessive wear and tear on the motion mechanism (i.e., the sample connector 60 attached to the shaft 30). Figure 1 As shown, the bearing assembly 50 is located in a housing anchored to the damping plate 40. The movement of the sample connector 60 can cause considerable axial displacement loads on the motor shaft 30, which can reduce the life of the motor. The bearing assembly 50 located between the sample connector 60 and the motor 20 protects the motor 20 primarily by preventing the shaft 30 from colliding with the motor 20 along its axis. That is, the movement of the sample connector 60 directs forces along the axis of the shaft 30 toward the motor 20, and the presence of the bearing assembly 50 greatly reduces these forces from colliding with the motor 20 to protect the motor and extend the life of the bead mill 100. The bearing assembly 50 avoids the need to replace components in the bead mill 100 in the early stages of product use. A second bearing assembly 61 similar to the bearing assembly 50 is disposed in the sample connector 60 to interact with the pin 34 and provide similar protection for the sample connector 60. Another bearing is disposed in the motor 20 itself.

[0036] The sample connector 60 is configured to be connected to a sample vial holder 70 by a novel clamping device. The sample vial holder 70 is located in a clamping base 62, which is firmly mounted or anchored to the top of the sample connector 60 so that the clamping base 62 moves with the rest of the sample connector 60. The clamping arm 64 is pivotally connected to one side of the clamping base 62 via a pin or bolt 67 so that it can swing toward and away from the clamping base 62. The clamping latch 66 is pivotally connected to the other side of the clamping base 62. The vial holder has wings 72 that are shorter than its total width and protrude outward from each side so that these wings 72 can be located between the two arms of the clamping base 62. This fixes the vial holder in the horizontal direction along the axis, while the clamping base 62 and the clamping arm 64 further fix the vial holder in other horizontal and vertical directions. When the clamping arm 64 is closed over the top of the sample vial holder and the vial therein, the clamping latch 66 can pivot to lock the clamping arm 64 firmly in place. In summary, the components of the sample connector 60 securely and reliably hold the sample vial holder 70 and the vials therein in its operational state throughout high levels of agitation and vibration and throughout the duration of the bead milling process. This vial holder mounting mechanism is unique in its form factor and application use for maintaining the integrity of the vial container. Figure 6 The sample holder is shown inserted into and clamping arms 64 to secure the holder. Figure 8Another clamping mechanism according to the present invention is shown, specifically a sample holder 170, a cartridge, a clamping base 162, a retention arm 164, and a locking mechanism assembly 166. The locking mechanism assembly 166 includes a horizontally oriented rod that swings toward the retention arm 164 and pins the distal end of the retention arm 164 underneath it while locking into a slot in the clamping base 162.

[0037] The bead mill 100 is designed to operate with a variety of materials that have different sizes and can be ground using different pulverizing media. One benefit of the design of the bead mill 100 is that it can accommodate and securely hold several different types of interchangeable sample vial holders, which allows different numbers and sizes of vial types to be used as needed. This design feature allows the bead mill 100 to handle very different vial form factors.

[0038] For example, in the sample vial holder used in the bead mill 100 in the bead mill (i.e., grinding) or mixing mode, the following is particularly provided. The first sample vial holder holds six 2ml plastic vials, each of which has a screw cap. The second sample vial holder holds four 5ml plastic vials, each of which has a screw cap or a slide cap. The third sample vial holder holds two 2ml cooled sample containers. The fourth sample vial holder holds two 1ml hardened tool steel vial sets. The fifth sample vial holder holds a 1.6 or 3.5ml agate vial set. The sixth sample vial holder holds a 5ml hardened tool steel vial set, for example, made of tungsten carbide. The seventh sample vial holder holds one to four 7 or 12ml plastic vials. These are just some examples of vial holders that can be used with the bead mill 100. It will be appreciated that different vial holders can be designed to hold different types of vials of different quantities and sizes as needed. For example, typical sample vial sizes range from 2 ml to 7 ml. Some instruments accommodate sample container sizes exceeding 75 ml. Vial sizes range between 2ml and 50ml. Some instruments limit sample vial size selection to 2ml, 5ml, and 7ml, while other units accept these and other vials such as 75ml vials, titer plates, 50ml QuEChERS vials, and many others. They can accommodate a full range of sample vials from 2mL to 50mL centrifuge tubes or up to six deep well titer plates.

[0039] 9A to 9C Three different sample vial sizes are shown, with each vial type having a different sample holder. More specifically, Figure 3 A 2 ml vial is shown, Figure 4 A 5 ml vial is shown, and Figure 5A 5 ml carbide steel vial is shown. Each vial holder has the same footprint so that it can be used with the sample connector 60 (more specifically, the same clamp base 62, clamp arm 64 and clamp latch 66).

[0040] Unlike other cell lysis and homogenization devices, the bead mill 100 is not limited to cell lysis and homogenization alone. It can use other types of sample vials to grind rocks, glass, cement, catalysts and other brittle samples. These sample vials have metal ends or are reinforced with metal at each end so that they can withstand the stronger forces generated by the brittle nature of these types of samples. The bead mill 100 can be used for sample preparation related to elemental analysis and particle size analysis using techniques such as XRF spectroscopy and inductively coupled plasma (ICP) emission spectroscopy. The unit is able to support heavier insulated vial assemblies to help temperature sensitive samples by limiting the temperature rise associated with the bead milling process. Other instruments cannot handle multiple sample containers for a range of applications from cell lysis to mechanical grinding, allowing rocks to be ground into powder.

[0041] In addition to using stronger vials, the sample vial holder 70 associated with the bead mill 100 has stronger and larger end walls 71, such as Figure 3 As shown. The hole of each vial is deeper so that the end wall 71 covers more area of ​​each top end and each bottom end of each vial. In one embodiment, the end wall 71 can cover more than 50% of the area of ​​each end face of the vial. In other embodiments, the end wall 71 can cover 60%, 70%, 80%, 90% or other percentages of the area of ​​each end face of the vial. In other embodiments, the profile of one or both end walls 71 is designed to completely cover the end of the vial. This enhances the strength of each vial end so that the balls or other media used for grinding will not quickly wear the vials during agitation and operation of the bead mill 100.

[0042] FIG. 10A to FIG. 10FAnother vial holder 270 is shown for a 5 mL metal vial 92, which may have a steel cap or a tungsten carbide cap. The vial holder 270 is designed to hold a vial 92 for grinding / crushing very hard materials (such as small rocks). The base 273 of the vial holder 270 supports a chamber area 274 in which the vial 92 is disposed. A lid 275 is pivoted at one end of the chamber via bolts or screws so that once the vial 92 is placed inside the chamber, the lid can cover the chamber. The other end of the chamber is provided with an end wall 271 to further secure the vial 92. The wings of the base 273 extend downwardly and cooperate with the sample connector 60, which covers and clamps the vial holder 270 as described above to secure the vial 92 in place during use. The lid does not need to be secured to the end wall 271 separately, because the vial holder 270 will only operate within the sample connector 60. That is, the clamping arm 64 secures the lid 275 in place during use, thereby securing the chamber. The vial holder 270 provides another embodiment of a fixed holder for different types of vials so that the bead mill 100 can accommodate these harder and more fragile samples.

[0043] Fig.11A and Fig. 11B A vial holder 370 is shown that is similar to another variation of the vial holder 270. The vial holder 370 is designed for a 3.5 mL agate vial 94 that is used for grinding hard materials that require an iron-free sample holder. When the clamp arm 64 is in place, both the vial holders 270 and 370 press the vial cap onto the vial to prevent sample powder from escaping from the vial.

[0044] like Fig.12 , Fig.13A and Fig. 13B As shown, one type of sample vial holder 470 according to the present invention is a holder for a cooled sample vial 96. All high energy bead mill machines heat the sample inside at a rate of about 10 degrees Celsius per minute due to frictional collisions of the beads during homogenization. An improved cooled vial assembly is provided to counteract the warming tendency of the machine operation. The cooled vial assembly uses a refrigerated circulator to provide temperature stability for the sample holder, including a dry air purge to reduce condensation.

[0045] A series of channels are provided in the sample connector 60, the sample vial holder 70 and / or the vials themselves to allow the passage of cooled liquid throughout the agitation process of the bead mill 100. These channels can be connected through the shaft 30 so that they can be accessed from the interior of the housing 10 during operation of the device. This allows the temperature of the sample to be maintained at a certain level throughout the process. Prior art devices using pre-cooling blocks do not have the same ability to continuously influence and control the temperature during operation of the machine.

[0046] The vial holder includes a housing 479 having a cavity 477 in which the vials 96 are disposed. Each cavity 477 is first provided with a holder plug 478 which itself has a cavity for inserting the vials 96. The holder plug 478 is placed in the cavity 477 so that a flange at its open end seals the cavity from the external environment and in some cases may be sealed with an O-ring or gasket. This creates a thin recessed cavity 476, such as Fig. 13B As shown, the cavity 476 encloses the bracket plug 478 such that cooling material can flow throughout the cavity 476 and around the bracket plug 478 .

[0047] The network of flow channels 482a to 482f is entered by flow ports 481a to 481b at the lower end of the housing 479. The flow ports are connected to inlet hoses and outlet hoses fixed by nuts 483a to 483b to provide and allow cooling fluid to leave from the vial holder. These hoses can extend through the bead mill 100 and can be connected to a pump and a coolant reservoir so that the bead mill 100 can circulate the cooling fluid. Flow port 481a leads to distribution channel 484a, which in turn leads to flow channels 482a to 482c. These flow channels 482a to 482c lead to corresponding concave cavities 476, so that the cooling fluid can be guided from the inlet hose to engage with each support plug 478. Then flow channels 482d to 482f allow the cooling fluid to leave the concave cavity 476 and enter the collection channel 484b, which empties the cooling fluid to the flow port 481b and discharges the outlet hose. A cooling fluid, such as water, a mixture of water and ethylene glycol, or any other type of fluid that can maintain extremely low temperatures (e.g., at or below the freezing point of water) and achieve proper circulation through the system can be provided at a constant temperature and circulated through this path so that the cooling fluid can absorb heat from the vial through the bracket plug 478 during grinding of the sample within the vial, thereby continuously maintaining a lower desired operating temperature.

[0048] The vial holder has a protective cover 488 that clips into a latch 489 so that the capped end of the vial can be securely retained in the receptacle during use. The protective cover 488 is thinner at its lower end to provide a recess on the side facing the vial so that the cap of the vial can be accommodated and shielded. A lower attachment 490 is provided to connect to the sample connector 60. In particular, the bottom frame portion of the vial holder has a central recessed area to allow connection to an external hose for fluid circulation, and also has a side frame with a window to allow the sample connector 60 to clamp the vial holder in a similar manner to that described above, but the clamping arm 64 extends through the frame instead of extending around the entire vial holder.

[0049] In another embodiment, the sample vial or sample vial holder 70 may include a phase change material (PCM) in its wall, which has a better ability to maintain low temperatures than the cooled metal currently used in prior art devices. Phase change material (PCM) products from PureTemp (such as PureTemp 4PCM material) have been used in experiments, and the characteristics of the phase change material product are such that a large amount of heat energy is required to allow a phase change from solid to liquid or from liquid to solid. The melting point of PureTemp 4 material is 4 degrees Celsius. PCM (such as PureTemp 4) can remain colder for a longer time after reaching a solid frozen state because such a material must absorb more heat energy before "melting". PCM can absorb a large amount of heat from the sample holder and sample, which otherwise may raise the temperature to an unacceptable level for some samples (such as RNA). During the RNA sample grinding process for DNA extraction, the sample needs to be kept below 4-5 degrees Celsius. During the sample grinding experiment, the sample temperature will rise due to the violent interaction of the steel balls in the vial.

[0050] Experiments were conducted using 2.5 grams of PCM inserted into the cavity of a 2 vial sample holder and secured within the cavity to prevent leakage. The PCM cavity was located between two 2 ml sample vials. The holder with vials was placed in a conventional refrigerator freezer for 1.5 hours and tested for temperature rise in a 1 minute "grinding" experiment at 4000 rpm in a SPEX SamplePrep GenoLyte, where the 2 mm vials contained 1 ml of water and seven 2.8 mm steel balls. As described below, the use of PCMs to reduce sample heating has proven to be very successful. Under normal grinding conditions, the outer surface of the vial rose by 15 degrees Celsius, while with the PCM integrated into the sample vial holder, the outer surface of the vial rose by only 3.5 degrees. The use of this type of material in sample grinding methods can be extended to many instruments, including SPEX SamplePrep's GenoGrinder, MixerMill and MiniG products.

[0051] The bead mill 100 includes a speed control mechanism that operates independently of the weight of the vial and the sample mass, because the speed is measured and maintained during grinding to ensure that the set speed is maintained each time it is used alone. This ability is provided by a measuring disk 80 that is rotationally coupled to the shaft 30 to rotate with it. The disk 80 includes a plurality of holes 82 and is positioned so that its peripheral edge and the hole 82 rotate between two plates 84, 86 of the optical interrupter, which pass the IR signal between the two and are anchored to the damping plate 40. The size and / or position of the hole 82 are known, and the frequency of the hole 82 passing between the plates 84, 86, more specifically the frequency of passing through the IR signal path, allows the recording of the detected IR signal interruption. This interruption corresponds to the passing of the solid part of the disk 80 between the holes 82. This allows the bead mill 100 to determine the rotation speed of the shaft 30 as follows. The plates 84, 86 communicate with the processor that receives the signal corresponding to the IR signal interruption. The processor then calculates the frequency of these interruptions, given the known radial distance of each hole 82 from the central axis of the shaft 30, and also given the known arc length between consecutive holes 82 (which arc length is a constant value for all adjacent pairs of holes 82 in the disk 80). The duration of one complete rotation of the shaft 30 can then be determined, from which the angular velocity or rotational speed can be determined. Figure 7 The components are depicted, showing how speed can be actively measured in real time to confirm the actual speed setting.

[0052] The bead mill 100 includes a digital display that can allow the user to provide inputs (such as time, speed, etc.) and can provide the user with a readout of the same metrics.

[0053] The bead mill 100 and its various novel components described herein may be used in a number of markets and applications including the following.

[0054] Agriculture: for plant research and crop science, residual pesticide analysis, food safety, disease research, protein extraction, soil research, biofuels, etc. Target customers will include crop research companies, environmental and agricultural testing companies and institutions, pesticide and fertilizer manufacturers, etc.

[0055] Forensic Science: For human identification, drug abuse, toxicology, etc. Target customers will include police laboratories, contract testing laboratories, archaeological laboratories, government laboratories, etc.

[0056] Mining & Cement: For grinding and crushing of cement and ores. Target customers will include mining production companies, steel mills, contract testing laboratories, cement production, government agencies, etc.

[0057] Pharmaceutical / Medical Research: For DNA extraction, mixing and blending, quality control, disease research, contamination testing, protein extraction, etc. Target customers will include pharmaceutical research companies, disease research institutions, biotechnology companies, contract testing laboratories, etc.

[0058] Materials Research: For mechanical alloying, mixing and blending, cryogenic grinding, sample size reduction for elemental studies (e.g. RoHS), and sample size reduction for pressed pellets and sample measurements. Target customers will include university engineering and materials science departments, battery manufacturers, solar companies, automotive companies, airlines, polymer production companies, contract testing laboratories, recycling companies, packaging companies, electronic goods manufacturers, etc.

[0059] Although the present invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are only illustrative of the principles and applications of the present invention. It should therefore be understood that various modifications may be made to the illustrative embodiments and other arrangements may be designed without departing from the spirit and scope of the present invention as defined by the appended claims.

[0060] Industrial Applicability

[0061] The present invention has broad industrial applicability, including but not limited to a bead mill homogenizer apparatus and a method for pulverizing and decomposing materials.

Claims

1. A bead mill homogenizer, comprising: a shaft having a body extending along a main axis and a distal connector extending along a connector axis at an acute angle to the main axis; a housing housing a motor configured to rotate the shaft about the primary axis; a head rotatably connected to the distal connector of the shaft and connected to the housing via a first spring on a first side of the shaft and a second spring on a second side of the shaft; and A clamp is secured to the head and is configured to secure a sample vial holder configured to hold one or more sample vials in a in, wherein the body of the shaft intersects the distal connector at a bend or elbow in the shaft such that rotational movement of the shaft about the main axis is converted into movement of the head in a direction perpendicular to the main axis, and wherein the distal connector is disposed within a lumen defined by the head, and wherein the pin is disposed within the lumen of the sample connector or the head such that the pin can rotate within the lumen during use.

2. The bead mill homogenizer according to claim 1, wherein Rotational movement of the shaft about the main axis is also converted into oscillatory movement of the head, causing the end of the head closest to the body of the shaft to pivot towards and away from the body of the shaft.

3. The bead mill homogenizer according to claim 1, wherein The clamp includes a clamp base, a clamp arm connected to the clamp base, and a clamp latch connected to the clamp base, wherein a sample vial holder can be disposed within the clamp base, and engagement of the clamp latch with the clamp arm secures the sample vial holder to the head.

4. The bead mill homogenizer according to claim 3, wherein: The clamp arm is pivotally connected to one side of the clamp base, and the clamp latch is pivotally connected to another side of the clamp base.

5. The bead mill homogenizer according to claim 1, wherein The fixture is configured to receive a plurality of differently configured sample vial holders.

6. The bead mill homogenizer according to claim 5, further comprising a plurality of sample vial holders in different configurations.

7. The bead mill homogenizer according to claim 6, wherein: The sample vial holders of the different configurations include at least two of the following: a first sample vial holder having only one hole for holding a vial; a second sample vial holder having only two holes for holding two vials; a third sample vial holder having only three holes for holding three vials; a fourth sample vial holder having only four holes for holding four vials; a fifth sample vial holder having only five holes for holding five vials; a sixth sample vial holder having only six holes for holding six vials; and A seventh sample vial holder has at least one hole for holding a vial and an internal channel network through which a coolant can pass to control the temperature of a vial disposed in the internal channel network.

8. The bead mill homogenizer of claim 1, further comprising a sample vial holder defining an internal channel network through which a coolant can pass to control the temperature of a vial disposed therein.

9. The bead mill homogenizer according to claim 8, wherein: The sample vial holder includes a housing defining a cavity configured to at least partially enclose a vial, and wherein the internal channel network includes an inlet channel, an internal channel adjacent the cavity, and an outlet channel connected for coolant flow.

10. The bead mill homogenizer according to claim 8, wherein: The sample vial holder includes a shell defining a cavity configured to at least partially enclose a vial, and a holder plug disposed in the cavity to seal the cavity from an external environment, the holder plug defining a cavity in which a vial can be placed.

11. The bead mill homogenizer according to claim 10, wherein: A hollow cavity is defined between an inner surface of the cavity of the housing and an outer surface of the stent plug.

12. The bead mill homogenizer according to claim 11, wherein The internal channel network includes an inlet channel leading to the empty cavity and an outlet channel exiting the empty cavity, such that the inlet channel, the empty cavity, and the outlet channel define a passage through which a coolant can pass to control a temperature of a vial disposed in the rack plug.

13. The bead mill homogenizer of claim 1, further comprising a first bearing assembly disposed about the shaft between the head and the motor.

14. The bead mill homogenizer according to claim 13, wherein: The head also includes a second bearing assembly disposed about the distal connection of the shaft.

15. The bead mill homogenizer according to claim 14, wherein: The motor includes a third bearing assembly.

16. The bead mill homogenizer according to claim 1, further comprising: a velocity measuring disc rotationally coupled to the body of the shaft, wherein the velocity measuring disc defines a plurality of apertures on a circumferential periphery thereof; and an optical interrupter having two plates between which the IR signal passes, wherein the circumferential periphery of the velocity measuring disk is disposed between the plates of an optical interrupter such that an aperture traverses a path of the IR signal.

17. The bead mill homogenizer of claim 16, further comprising a processor that receives a signal corresponding to an interruption of the IR signal and is configured to use the signal to calculate the rotational speed of the shaft.

18. The bead mill homogenizer according to claim 1, wherein: The sample vial holder has end walls that respectively cover at least 50% of the area of ​​each end face of the vial.

19. The bead mill homogenizer according to claim 1, wherein: Rotational movement of the shaft about the primary axis rotates the distal attachment member such that the distal attachment member scans an imaginary conical surface.

20. The bead mill homogenizer according to claim 19, wherein Rotational movement of the shaft about the major axis causes the head to rotate along a circular path on an imaginary conical surface.

21. A bead mill homogenizer, comprising: a shaft having a body extending along a main axis and a distal connector extending along a connector axis at an acute angle to the main axis; a housing housing a motor configured to rotate the shaft about an axis and including a first bearing assembly; a head rotatably connected to the distal connection of the shaft and connected to the housing via a first spring on a first side of the shaft and a second spring on a second side of the shaft, wherein the head includes a second bearing assembly disposed about the distal connection of the shaft; a sample vial holder secured to the head; and a third bearing assembly disposed about the shaft between the head and the motor, wherein the body of the shaft intersects the distal connector at a bend or elbow in the shaft, and Wherein, the distal connector is disposed in an inner cavity defined by the head.

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