Claims:1. A centrifuge rotor comprising a rotor body made of a polymer material and a reinforcement fixed to the rotor body such that the reinforcement lies in a plane perpendicular to an axis of rotation of the centrifuge rotor.
2. The centrifuge rotor as claimed in claim 1, wherein the reinforcement is of planar shape.
3. The centrifuge rotor as claimed in claim 2, wherein the reinforcement is fixed to a bottom side of the rotor body.
4. The centrifuge rotor as claimed in claim 2, wherein the reinforcement is fixed to the rotor body by a plurality of screws.
5. The centrifuge rotor as claimed in claim 2, wherein the reinforcement is made by any or a combination of laser cutting process and stamping process.
6. The centrifuge rotor as claimed in claim 2, wherein the reinforcement is annular shaped and is fixed concentrically to the axis of rotation of the centrifuge rotor.
7. The centrifuge rotor as claimed in claim 6, wherein the bottom side of the rotor body includes an annular shaped recess in which the reinforcement is fixed.
8. The centrifuge rotor as claimed in claim 7, wherein the centrifuge rotor is a swing out rotor and the annular shaped reinforcement has an inner hole sized such that a plurality of sample holders of the centrifuge rotor, in a tilted position, are accommodated within the inner hole of the annular shaped reinforcement.
9. The centrifuge rotor as claimed in claim 2, wherein the reinforcement is disc shaped and is fixed concentrically to the axis of rotation of the centrifuge rotor.
10. The centrifuge rotor as claimed in claim 9, wherein the centrifuge rotor is a fixed angle rotor and the disc shaped reinforcement includes a plurality of openings configured such that a plurality of sample holders project out through the plurality of openings of the disc shaped reinforcement.
11. The centrifuge rotor as claimed in claim 10, wherein the rotor body includes an inner hollow and the disc shaped reinforcement is configured as a cover to close the inner hollow from a bottom side of the rotor body.
12. The centrifuge rotor as claimed in claim 11, wherein the rotor body includes a plurality of bosses and a rim portion, wherein the plurality of bosses are configured to support and fix the disc shaped reinforcement, and the rim portion is configured to support an outer periphery of the reinforcement.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of centrifuges. In particular, the present disclosure relates to a centrifuge rotor having reinforced rotor body made of a polymer.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Centrifuges are well known in the field of separation of fluids. They are used in different fields, such as medicinal field, chemical field etc., to separate fluids of different densities by applying centrifugal force to materials or contents present in the centrifuges. A centrifuge includes a rotor/ centrifuge rotor that is detachably connected to a shaft/ spindle of a motor for rotation at a high speed. The rotor includes multiple cavities/opening/holes for holding containers, such as tubes, for holding the fluid samples. The holes may be inclined at a predetermined angle with respect to the rotor’s axis of rotation, or may be oriented so that the axis of the cavities may lie parallel to the axis of rotation.
[0004] Traditionally, centrifuge rotors are made of aluminum. Usually the low speed rotors are made with cast aluminum and high speed ones are machined from a high strength grade aluminum. The rotors that are subjected to a very high load made of steel, and those for ultra-high speeds applications are made of titanium alloys, and some times of carbon fibre material
[0005] Machined aluminum rotors are expensive to manufacture as they consume a lot of resources to manufacture. Therefore, recently machined plastics and injection molded plastics have been used for low speed and low load applications. Plastics are lightweight and can be easily molded to shapes, they cost less. However, when subjected to load, they creep expand and shatter. Therefore, their behavior is unpredictable and their life is very limited.
[0006] Typically, the centrifugation industry are made of a single material, and when the metal inserts are used, such as in rotors made of plastic material, the inserts are to accommodate the fastening and mounting purpose only.
[0007] There is therefore a need in the art to provide improved and cost effective rotors that overcome limitations of the conventional rotors.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0013] A general object of the present disclosure is to overcome drawbacks of the conventional centrifuge rotors.
[0014] An object of the present disclosure is to provide an improved, simple and cost effective centrifuge rotor.
[0015] Another object of the present disclosure is to provide an improved rotor that is easy to manufacture.
[0016] Another object of the present disclosure is to provide a centrifuge rotor made of a polymer material that does not creep or shatter under working loads.

SUMMARY
[0017] Aspects of the present disclosure relate to an improved centrifuge rotor (also referred to simply as rotor and the two terms used interchangeably hereinafter) that includes a body (also referred to as rotor body and the two terms used interchangeably hereinafter) is made of a polymer material but reinforced to enable operation at higher speeds and loads. In an aspect, the reinforcement is configured on the rotor such that it shares at least a part of stresses acting on a rotor body of the rotor, thereby reducing stresses on the rotor body. Reduced stresses on the rotor body enables it to be operated at higher speeds and loads.
[0018] In an aspect, the reinforcement is fixed to the rotor body such that the reinforcement lies in a plane perpendicular to an axis of rotation of the centrifuge rotor.
[0019] The reinforcement may be of planar shape and made by any or a combination of laser cutting process and stamping process.
[0020] The reinforcement may be fixed to a bottom side of the rotor body. A plurality of screws may be used to fix the reinforcement to the rotor body.
[0021] The reinforcement may be annular shaped and may be fixed concentrically to the axis of rotation of the centrifuge rotor. The bottom surface of the rotor body may include an annular shaped recess in which the annular shaped reinforcement may be accommodated and fixed.
[0022] The centrifuge rotor may be a swing out rotor and the annular shaped reinforcement may have an inner hole sized such that a plurality of sample holders of the centrifuge rotor, in a tilted position, are accommodated within the inner hole of the annular shaped reinforcement.
[0023] In an alternate application, the reinforcement may be disc shaped and may be fixed concentrically to the axis of rotation of the centrifuge rotor. The centrifuge rotor may be a fixed angle rotor and the disc shaped reinforcement may include a plurality of openings configured such that a plurality of fixed sample holders project out through the plurality of openings of the disc shaped reinforcement. The rotor body may be hollow inside being open from a bottom side of the rotor body, and the reinforcement may be configured as a cover to close the inner hollow from a bottom side of the rotor body. The rotor body may include a plurality of bosses to support and fix the reinforcement, and a rim portion where an outer periphery of the reinforcement may rest.
[0024] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0026] FIG. 1 is an exploded view of a conventional fixed angle rotor made of aluminum by machining process.
[0027] FIG. 2 shows perspective views of conventional swing out rotors made of aluminum by machining process.
[0028] FIG. 3 shows perspective views of conventional fixed/ swing out rotors made of machined/ molded plastic.
[0029] FIGs. 4A to 4C respectively illustrate exemplary exploded view, sectional view and a bottom view of the disclosed swing out rotor made of plastic, showing a planar and annular shapes reinforcement fitted in a recess on a bottom side of a rotor body of the centrifuge rotor, in accordance with the second embodiment.
[0030] FIGs. 5A to 5C respectively illustrate exemplary exploded view, bottom view and sectional view of the disclosed fixed angle rotor made of plastic, showing a disc shaped planar reinforcement fitted as a cover on a bottom side of a hollow rotor body of the centrifuge rotor, in accordance with the second embodiment.

DETAILED DESCRIPTION
[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0032] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0033] Various terms are used herein. To the extent a term used in a claim is not defined, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0034] Embodiments explained herein relate to a centrifuge rotor. As known in the art, centrifuge rotors are configured to holed a plurality of sample holders and rotated at high speed about a rotational axis
[0035] FIG. 1 shows an exploded view of a conventional fixed angle rotor made of aluminum by machining process. A conventional rotor 100 made of aluminum includes a rotor body 102 machined from aluminum, a rotor cover 104 having a threaded portion 106 that fits with a corresponding threaded hole in the rotor body 102 and a knob 108 for locking the rotor cover 104. A rotor packing 110 is provided between the rotor body 102 and the rotor cover 104. The rotor cover 104 may also be machined from aluminum.
[0036] FIG. 2 shows perspective views of conventional swing out rotors made of aluminum by machining process. The conventional rotor 200 includes a rotor body 202 that is machined from aluminum with intricate shape that enables pivotally holding of a plurality of sample holders 204.
[0037] FIG. 3 shows perspective views of conventional fixed/ swing out rotors made of machined/ molded plastic. The conventional rotor 300 includes a rotor body 302 that is machined or molded from a plastic material such that the machined shape is configured to hold a plurality of sample holders 304.
[0038] While metallic rotors, such as rotor 100 and 200, on account of high strength of the material of the rotor 102/202, have capability to withstand high centrifugal forces when used at high speeds, they are expensive to make due to costly machining process to achieve the intricate shapes. On the other hand, the plastic rotors, such as rotors 300, made by molding process are cheap to make, but lack capability to be used as high speeds due to lower strength of plastics. Therefore, for higher load and speeds, metallic rotors have to be used which are costlier.
[0039] The disclosed centrifuge rotor is made of a polymer material and is reinforced to enable its operation at higher speeds and loads. While the polymer material allows the body to be molded to intricate shape required to enable accommodating, holding, access and aerodynamic functions, the reinforcement takes care of the structural strength requirements. The reinforcement shares a major portion of the high centrifugal forces generated during centrifugation thereby reducing the stresses on the plastic body and enabling operation at higher speeds, which provides a distinct advantage.
[0040] In an aspect, the reinforcement is restricted to a single plane, and therefore is subjected to only tensile stresses due to centrifugal forces, thereby not requiring expensive manufacturing processes such as casting, machining or forming. A planer shape of the reinforcement enables mass production of the reinforcement by laser cutting or stamping with corresponding cost advantages, besides the cost advantage associated with having a plastic rotor body.
[0041] In an aspect, the planer reinforcement may be configured as having a symmetrical shape and fitted to the plastic body in a plane perpendicular and concentric to an axis of rotation of the rotor. In different applications, the reinforcement can be annular shaped fitted in a recess on a side surface of the rotor body, or can be disc shaped having a plurality of circumferentially spaced openings to accommodate sample holders and a central opening to enable fitment of the rotor to a spindle /shaft. In other applications, the reinforcement may be configured as a cover for fitment on a side of the body supported and fixed on a plurality of bosses and a rim of the rotor body to close an inner hollow of the rotor body.
[0042] Fitment of the reinforcement on the rotor body may be configured such that inertia forces on the body and other parts, such as sample holders, fitted to the body, due to high-speed rotation are transferred to the reinforcement, reducing the stresses on the plastic body. Reduced stress on the body, which is made of plastic, increases life of the rotor. In addition, a plastic body, besides being economical to manufacture, also imparts good finish. Aesthetics, consistent manufacture, corrosion resistance and the advantage of low weight of the centrifuge rotor.
[0043] Referring now to FIGs. 4A to 4C, where different views of a swing out rotor made of plastic with a reinforcement is disclosed, the rotor 400 can include a rotor body 402 configured with a plurality of sample holders 404 that holds samples 406. The rotor 400 further includes an annular shaped planar reinforcement 408 that can be fitted to a bottom face of the body 202, which bottom face is perpendicular to a rotational axis of the rotor 400. The reinforcement 408 can be fitted to the bottom face by a plurality of screws 410. As is evident from FIG. 1A, the reinforcement 408 is sized such that the plurality of sample holders 404 of the centrifuge rotor 400, in their tilted position, are accommodated within the inner hole of the annular shaped reinforcement 408.
[0044] The cross sectional view at FIG. 4B shows the reinforcement 408 fitted in a recess on a bottom side of the body 402 concentric to a rotational axis of the rotor 400.
[0045] FIGs. 5A to 5C show different views of a disclosed fixed angle rotor made of plastic with a reinforcement. The fixed angle rotor 500 includes a plastic body 502, which is includes an inner hollow and open from a bottom side. The reinforcement 508 can be disc shaped and may be fixed by screws 510 concentrically to the axis of rotation of the centrifuge rotor 500 as a cover to close the bottom opening of the rotor body 502. The disc shaped reinforcement 508 may include a plurality of openings configured such that a plurality of fixed sample holders 504 having the samples 506 project out through the plurality of openings of the disc shaped reinforcement 508. The rotor body may include a plurality of bosses to support and fix the reinforcement, and a rim portion where an outer periphery of the reinforcement may rest.
[0046] The reinforcement s 408/508 of different embodiments, being of planar shape can be economically mass produced by any of laser cutting or stamping. The planar reinforcements 408/508 can of a high strength steel capable of withstanding stresses due to centrifugal inertia forces transferred from the body 402/502. As can be understood by those skilled in the art, the reinforcements 408/508 can also be made of acCarbon fibre composite in place of a metal to achieve the same results. It is also possible to use the reinforcement to pre-stress the material of the rotor body, which can result in achieving ultra high speeds for the rotors.
[0047] Thus, the present disclosure provides a centrifuge rotor made of plastic that provides benefits of economical manufacture, intricate shapes and ease of mass manufacture associated with use of plastic/polymer material without its drawbacks, i.e., inability to use in high load and high speed applications.
[0048] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0049] The present disclosure overcomes the drawbacks of the conventional centrifuge rotors.
[0050] The present disclosure provides an improved, simple and cost effective centrifuge rotor.
[0051] The present disclosure provides an improved rotor that is easy to manufacture.
[0052] The present disclosure provides a centrifuge rotor made of a polymer material that does not creep or shatter under working loads.