Patent Application
20210107009
The invention pertains to laboratory products and in particular to clamps for laboratory shakers.
Shakers are widely used in laboratories to stir liquids held in beakers, flasks or test tubes. The shaker has a platform that oscillates horizontally when the shaker is operating. A shaker platform will normally include an array of threaded holes to enable attachment of clamps to the platform with threaded fasteners such as screws or bolts. Metal flask clamps for Erlenmeyer flasks typically include a pair of intersecting bands that extend horizontally to form a base and bend upward to extend above the hip of the flask and along the tapered wall of the flask. Normally, a spring coil is attached around the ends of the bent bands. The flask is inserted into the clamp by expanding the spring coil and the bands outwardly by pressing the base of the flask into the opening created by the spring coil. One of the issues with metal clamps of that flasks tend to spin within the clamps when the shaker operates. The spinning can cause marring if the flask is made of glass, and in fact can cause substantial damage if the flask is made of plastic. Another issue is that metal springs require extreme forces to insert or remove the flask, and there is the danger of flask breakage. In addition, the metal springs tend to deform and loosen after repeated use and the flasks tend to rattle loosely inside the metal flask clamp creating significant noise pollution in the workspace. If the flask contains a large volume of fluid significant torque is generated which can cause the flask to spin excessively within the clamp especially if the metal springs are loose. As a result, there is a need for improved flask clamps for laboratory shakers.
Disclosed herein are flask clamps that capture and firmly hold flasks or vessels of various shapes, enclosing the sidewall of the flask or vessel in a trap or loops. The trap relatively conforms to the profile of the perimeter of the vessel and are spring loaded in the upward direction in order to rise upward along the sides of the vessel. The loops pivot relative to the bottom of the flask creating an arc motion that tightens against the sidewall as it rises. The loaded loops are in tension against the flask, and the multiplicity of loops hold vessels in tension with opposing forces.
The clamp comprises a base and a multiplicity of interlaced loops. Each of the interlaced loops comprise a first end, a second end, and a curved member between the first end and the second end. The multiplicity of interlaced loops are pivotally connected by the first end and the second end to the periphery of the base, the curved members are configured to spontaneously coalesce, and interlaced loops are configured for concerted movement when an effective opening force is applied to any curved member.
In one embodiment, the base comprises a multiplicity of socket pairs comprising a first socket and a second socket. The multiplicity of socket pairs is equal to the multiplicity of interlaced loops, and the first socket and the second socket of a single socket pair are configured to receive the first end and the second end of a single interlaced loop. In certain embodiments, the first and second socket are axially offset from one another. When the first and second ends are placed into the offset axially-parallel sockets, the interference loads the wire to move in an upward direction to a neutral load position.
In another embodiment, the multiplicity of interlaced loops are pivotally connected to the base via a multiplicity of torsion spring pairs comprising a first torsion spring formed from or connected to the first end of a single interlaced loop and a second torsion spring formed from or connected to the second end of the single interlaced loop, and the multiplicity of torsion spring pairs is equal to the multiplicity of interlaced loops.
The interlaced loops may further comprise a catch configured to engage another of the loops when each of the multiplicity of interlaced loops are in a coalesced state, forming an opening for receiving a flask. In certain embodiments, the catch comprises a sigmoidal turn within the curved member.
In some embodiments, the clamp comprises two, three or four interlaced loops. In a particular arrangement, a first wire loop is arranged over a second wire loop and under a third loop; the second wire loop is arranged over the third wire loop and under the first loop; and the third loop is arranged over the first loop and under the second loop. The first loop may comprise a catch configured to engage the second loop; the second loop may comprise a catch configured to engage the third loop; and the third loop may comprise a catch configured to engage the first loop.
In some embodiments, the clamp is configured to receive an Erlenmeyer flask, a Florence flask, a round-bottom flask, or a cylindrical beaker.
Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention.
Disclosed herein are flask clamps that capture and firmly hold flasks or vessels of various shapes, enclosing the sidewall of the flask or vessel in a trap or loops. The trap relatively conforms to the profile of the perimeter of the vessel and are loaded in order to rise along the sides of the vessel. The loops pivot relative to the bottom of the flask creating an arc motion that tightens against the flask's sidewall. The loaded loops are in tension against the flask, and the multiplicity of loops hold vessels in tension with opposing forces.
There are a number of advantages that may be realized by using the clasps as described herein. These clamps may be used with thin-walled and/or plastic flasks susceptible to crushing by the clamps known in the art since the compressive force applied by the loops onto the side wall is distributed around a majority of the periphery. The clamps continuously self-tighten with any flask movement away from center. The clamps allow for quiet operation and minimize marring of the sidewall surface because rattling of the flask is minimized or eliminated entirely. The clamps also allow for flask size variance such as texture, diameter, height, and pitch. The force applied to any one loop is transferred to all of the loops, allowing for easy insertion or removal of the vessel. The profile of the loops may be thin to provide for minimally obstructed viewing of the contents within the flask. Moreover, the clamp may be constructed without sharp edges of sheet metal profiles that can cut or abrade personal protective equipment, such as gloves, or the user's skin.
The flask clamp includes a flask holding mechanism attached to the clamp base. The flask holding mechanism comprises a multiplicity of interlaced loops. Each of the loops comprise a first end, a second end, and a curved member between the first and second ends. In the exemplary embodiments illustrated below, the loops have a D-like profile, but other profiles may be used however. The loops may optionally comprise contoured rollers attached to the curved members. The wire loops may be pivotally connected to the periphery of the base.
Because the loops are interlaced, some of the advantages described above are realized. The loops may spontaneously coalesce. As used herein, “spontaneously coalesce” means that the curved member of each loop is capable of moving away from the base and inwardly toward an imaginary line normal to the center of the base after an effective opening force is removed from the curved member without apparent external influence, force, or cause due to the loading on the loops. Because the loops are interlaced, they can coalesce and form an opening for receiving the flask. The loops may also comprise a catch for engaging another loop, resulting in a coalesced state and forming an opening of a designed size for receiving a flask. As used herein, a “coalesced state” means the opening formed from the loops is minimized. In some cases, the catch is a sigmoidal turn in the curved member.
The loops may be interlaced in an over-under arrangement. For a flask having three loops, the underside of a catch on a first loop engages an adjacent second loop, the underside of a catch on the second loop engages a third loop, and the underside of a catch on the third loop engages the first loop. Although the immediately prior example illustrates the over-under arrangement with three loops, the clamp may have any suitable number of loops. Suitably, the clamp may be formed from 2 loops, 3 loops, 4 loops, 5 loops, 6 loops, or more than 6 loops. Embodiments having 4, 5 or 6 loops of wire offer redundant strength to eliminate single fault failure and loss of flask containment or may be more suitable for larger flasks.
A force applied to one of the loops will be transferred to all of the other loops. Interlacing the loops results in concerted movement between the loops. This advantageously allows for a flask to be easily inserted into or removed from the clamp. An effective opening force applied to any one curved member in the direction of the base will cause the opening formed by the curved members to widen, allowing for the flask to be inserted. As used herein, an “effective opening force” is a force sufficient to increase the size of the opening relative to the size of the opening in a coalesced state. Moreover, an effective opening force applied to any one curved member in the direction of the base will cause the opening formed by the curved members to widen, allowing for the flask to be removed from the clamp.
The clamp may have a generally circular base and the loops may be evenly spaced around the periphery. The loops may be connected to the base in any suitable manner that results in loading the holding forces. Loading may be affected by the positioning of the curved members, the form for the curved members, the mechanical properties of the curved members, or any combination thereof.
In some embodiments, the base comprises a multiplicity of socket pairs. Each of the socket pairs comprises a first and a second socket. The number of socket pairs may be equal to the number of loops so as to receive the first and second end of a loop in the first and second socket. In certain embodiments, the first and second socket are axially offset from one another and arranged along the periphery of the base. Because the sockets are axially offset, a suitably conformed loop with result in spring-like loading. The offset sockets create a torsion effect on the spring wires, clamping onto the flask, and allow for the benefits described herein.
In another embodiment, the loops may be connected to the base via a multiplicity of torsion spring pairs. The torsion spring pairs comprise a first and a second torsion spring formed from or connected to the first and second end of the loop, respectively. The torsion springs load the loop and allow for the benefits described herein.
The clamps described herein may be used in variety of different settings. In one embodiment, the clamp is configured for use with a laboratory shaker. An exemplary embodiment is illustrate in
The clamp base may include a removable, elastomeric cover that provides a frictional surface for the base of the flask. The frictional forces on bottom surface of the flask prevent the flask from spinning when the shaker is in use. The downward component of the normal force exerted on an Erlenmeyer flask by the clamp facilitates the effect of the frictional surface. The elastomeric cover also preferably includes an overlapping lip that extends over the peripheral edge of the base, and in some places underneath the base. The lip provides a seal against the shaker platform in case of a spill inasmuch as magnetic pressure pulls the base of the flask clamp and the elastomeric lips against the shaker platform. It has been found that the above described configuration including the elastomeric, replaceable cover and the contoured plastic rollers (or roller sets) provide a desired amount of cushioning and significantly quieter operation of the shaker.
One or more permanent magnets may be attached and exposed below the base, preferably three nickel-coated, rare earth magnets equally spaced around the periphery of the base. For stability purposes, it has been found desirable to equally space the magnets from one another and also locate the magnets near the periphery of the clamp base. Placing the magnets near the periphery of the clamp base maximizes flux density of the magnetic field near the periphery of the base, as opposed to using a single magnet centered under the flask.
The nickel-coated, rare earth magnets are preferably flat magnets, and the flat bottom surface of the magnets (as well as a magnetic base plate) are magnetically attracted to the shaker platform, which is preferably made of magnetic, non-magnetized stainless steel. The nickel coating helps to protect the rare earth magnets from corrosion and chipping and also provides an improved surface for adhesion of the magnets to the clamp base. In addition, the use of a nickel coating does not compromise the viability of biological cells in the laboratory, as would for example a zinc coating. The use of multiple rare earth magnets allows for the polar alignment of the magnets to be optimized in order to increase the magnetic flux density between the flask clamp base and the platform. For example, staggered polar alignment may increase magnetic flux density and overall attraction of the clamp to the shaker platform. The rare earth magnets are preferably adhered to the top base plate which is made of magnetic stainless steel. The use of the magnetic stainless steel top base plate reduces the magnetic field in the flask and additionally helps to focus magnetic flux density (magnetic attraction) between the base plate and the shaker platform. In an alternative embodiment, the rare earth magnets can be manufactured with a step peripheral shoulder, and instead of using adhesive to attach the magnets to the top base plate, the magnets are attached to the base by mechanically capturing the shoulders on the magnets between the plates in the base assembly.
The base of the flask clamp may also include downwardly extending positioning bosses, for example three or more positioning bosses may be made of the same material as the base of the clamp or made of an engineered thermal plastic such as polyoxymethylene. The downwardly extending bosses are sized and configured to fit into clamp positioning holes or indentations on the shaker platform when the flask clamp is positioned on the shaker platform with the magnets exerting magnetic pressure to hold the flask clamp on the shaker platform. The positioning bosses prevent the flask clamp from sliding on the surface of the shaker platform while the shaker is in use. The clamp positioning holes or indentations on the shaker platform are preferably non-threaded such that the positioning bosses can be easily set in the holes or indentations without a tool.
In some embodiments, the clamp base may be mechanically fastened to the shaker platform with one or more threaded fasteners such as screws, bolts, or other suitable fastening components.
The clamp base as described above can be used to hold other types of laboratory containers besides an Erlenmeyer flask, e.g., a Florence flask, a round-bottom flask, or a cylindrical beaker. Suitably the clamp may be configured to receive any flask or laboratory having a profile similar to any of the forgoing.
The clamp and its components may be prepared of any suitable material. Wire form loops may be preferred for certain applications due to its tensile strength and ability to be repeatedly autoclaved, but a similarly functioning assembly may be prepared in alternative materials, such as plastic that can be molded inexpensively. Those of skill in the art are capable of selecting materials for appropriate specialty applications.
An exemplary embodiment of the invention is depicted in the Figures.
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Unless otherwise specified or indicated by context, the terms “a”, “an”, and “the” mean “one or more.” For example, “a molecule” should be interpreted to mean “one or more molecules.”
As used herein, “about”, “approximately,” “substantially,” and “significantly” will be understood by persons of ordinary skill in the art and will vary to some extent on the context in which they are used. If there are uses of the term which are not clear to persons of ordinary skill in the art given the context in which it is used, “about” and “approximately” will mean plus or minus ≤10% of the particular term and “substantially” and “significantly” will mean plus or minus >10% of the particular term.
As used herein, the terms “include” and “including” have the same meaning as the terms “comprise” and “comprising.” The terms “comprise” and “comprising” should be interpreted as being “open” transitional terms that permit the inclusion of additional components further to those components recited in the claims. The terms “consist” and “consisting of” should be interpreted as being “closed” transitional terms that do not permit the inclusion additional components other than the components recited in the claims. The term “consisting essentially of” should be interpreted to be partially closed and allowing the inclusion only of additional components that do not fundamentally alter the nature of the claimed subject matter.
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 herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
Preferred aspects of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred aspects may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect a person having ordinary skill in the art to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This application claims benefit of priority to U.S. Provisional Application Ser. No. 62/658,225, filed Apr. 16, 2015, the contents of which are incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/027608 | 4/16/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62658225 | Apr 2018 | US |
