Accurate positioning and alignment of devices can be a major requirement during operation of an apparatus. For example, in a system comprising optical and/or optomechanical devices (such as a beam splitter, a gas cell, a lens, a mirror, etc.), passage of electromagnetic radiation through the various devices is desirably controlled to facilitate a very high degree of accuracy in whatever experiments, measurements, etc., are being conducted with the devices.
When performing an experiment utilizing electromagnetic radiation having a narrow frequency range, precise positioning of a lens with respect to a beam of radiation may be critical to facilitate passage of the beam of radiation through the lens as opposed to a portion or all of the beam being reflected off the surface of the lens, for example, when the surface of the lens is not correctly aligned perpendicular to the path of the beam.
The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.
Described herein are various technologies pertaining to a kinematic mount, which is employable to relatively precisely position devices relative to one another. The kinematic mount may be particularly well-suited for employment with relatively complex optical systems, which comprise beam-splitters, gas cells, lenses, mirrors, and other devices. An exemplary kinematic mount comprises a plurality of kinematic apparatuses, wherein each kinematic apparatus in the plurality of kinematic apparatuses can be interacted with to adjust position of a device. An exemplary kinematic apparatus includes a cylindrical alignment tube having a proximal end and a distal end, wherein an exterior of the alignment tube is threaded. The kinematic apparatus also includes a spherical alignment ball that includes a threaded aperture. A diameter of the alignment tube corresponds to a diameter of the threaded aperture of the alignment ball, such that the threaded exterior of the alignment tube at the proximal end thereof is configured to mate with the threaded aperture of the alignment ball. The distal end of the alignment tube can include, for instance, a hexagonal head.
The kinematic mount further comprises a planar base plate, wherein the base plate includes a plurality of recesses. A number of recesses in the plurality of recesses can correspond to a number of kinematic apparatuses in the plurality of kinematic apparatuses. A respective pair of roller bearings can be positioned in each recess, wherein roller bearings in a pair of roller bearings are arranged in parallel with one another and are separated by a gap. A respective alignment ball may be positioned to rest on each pair of roller bearings.
The kinematic mount additionally includes a support structure, upon which, for example, a desirably positioned device can rest. The support structure, in an exemplary embodiment, comprises a plurality of flanges, with each flange having a threaded aperture therethrough. Positions of the threaded apertures on the support structure correspond to respective positions of the recesses of the base plate. Further, diameters of the threaded apertures of the support structure correspond to diameters of the respective alignment tubes of the kinematic apparatuses, such that threads of an alignment tube can mate with threads of a respective threaded aperture of the support structure.
In operation, when the alignment tubes of the respective kinematic apparatuses are threadedly mated with respective threaded apertures of the support structure, and the alignment balls are resting upon respective pairs of roller bearings of the base plate, the alignment apparatuses can be rotated about respective lengths thereof, thus causing position of the support structure with respect to the base plate to alter. Accordingly, height of the support structure over the base plate, as well as tilt of the support structure, can be relatively precisely configured, thereby allowing a position/tilt of a device resting upon or attached to the support structure to be relatively precisely configured.
Other aspects will be appreciated upon reading and understanding the attached figures and description.
Various technologies pertaining to relatively precisely positioning a device through utilization of a kinematic mount will now be described with reference to the drawings, where like reference numerals represent like elements throughout. As used herein, the term “exemplary” is intended to mean serving as an illustration or example of something, and is not intended to indicate a preference. Additionally, as used herein, the terms “approximately” and “about” are intended to encompass values within 10% of a specified value.
With reference now to
The alignment assembly also includes an alignment ball 130 (which may also be referred to as an aligning ball, tooling ball, or ball) having a threaded aperture 113 extending partially therethrough. A diameter of the alignment tube 110 corresponds to a diameter of the threaded aperture 113, and pitch of threads along the exterior of the alignment tube 110 correspond to pitch of threads of the threaded aperture 113, such that the thread 115 of the alignment tube 110 mates with the threaded aperture 113, thus facilitating connection of the alignment tube 110 to the alignment ball 130. A flange 120 has a threaded aperture 125 extending therethrough, wherein a diameter of the threaded aperture 125 corresponds to the diameter of the alignment tube 110, and pitch of the thread 115 corresponds to pitch of thread in the threaded aperture 125, such that threads of the alignment tube 110 can mate with threads of the threaded aperture 125. The flange 120 can be a portion of a support structure, upon which an optical device, for instance, can rest or be attached. The support structure can be planar, such that the flange 120 is a portion of a flat plate. In other exemplary embodiments, the flange 120 can be a raised or recessed portion of the support structure.
In an exemplary embodiment, the alignment tube 110 can comprise a through hole 112, and similarly the alignment ball 130 can include through hole 114 formed therein, as further described in
The support assembly comprises a base 150, which can optionally include a recess. A plurality of support bearings 140 are positioned on the base 150, optionally in the recess. The support bearings, in an exemplary embodiment, can be roller bearings that are cylindrical in shape and are arranged in parallel with one another. The alignment ball 130 is positioned to rest upon the support bearings. Thus, as shown in
In an exemplary embodiment, the alignment ball 130 can remain located on bearings 140 by means of gravity acting vertically in direction X on the mass of the kinematic assembly 100, where in effect the mass of the kinematic assembly 100=the mass of the flange 120 (plus any plate, support, device connected thereto)+the mass of the alignment tube 110+the mass of the alignment ball 130.
As depicted in
To facilitate a change in position of the flange 120 on alignment tube 110, and accordingly the position of the flange 120 with respect to the base 150 (as indicated by the line H of
It is to be appreciated that while
Turning to
The fastener 310 can be secured (e.g., through use of an allen key or similar device) into the threaded aperture 350 of the base 150, thereby securing the alignment tube 110, the alignment ball 130, and the flange 120. As illustrated, the diameter of the through hole 114 of the alignment ball 130 can be less than the diameter of the through hole 112 of the alignment tube 110, thereby forming, at the junction of the through hole 112 and the through hole 114, a step S against which the lower washer 330 can be located. Hence, when the fastener 310 is tightened onto the base 150 via the threaded aperture 350, a locking force is applied from the fastener 310 to the alignment ball 130 via the spherical washers 320 and 330. Similarly, to unlock the alignment tube 110 and the alignment ball 130 from the base 150, the fastener 310 can be loosened in the threaded aperture 350, thereby releasing the locking force on the spherical washers 320 and 330 and enabling movement of the alignment tube 110 and the alignment ball 130. If required, e.g., during operation of the kinematic assembly 300 (or assemblies 100 as shown in
With knowledge of various parameters relating to the respective threads of the alignment tube and threads of the threaded aperture 125 of the flange 120, positioning of the flange 120 can be closely controlled, where such parameters include the thread pitch, thread diameter (major, minor, pitch), etc. Further, with such knowledge, it is possible to determine an angle of revolution of the alignment tube 110 and a corresponding change in height H of the flange 120. For example, where a combination of thread pitch and thread diameter is configured such that a 1° of rotation of the alignment tube 110 results in a corresponding change of 0.001″ (or mil) in position of the height of the flange 120, if the flange 120 is to be moved 0.01″ (or 10 mils), the alignment tube 110 can be turned through 10° in the required direction to facilitate the adjustment resolution.
Further, as illustrated in
As previously mentioned, the exemplary assemblies 100 and/or 300 can be utilized to facilitate alignment of a portion of an optical system, a portion of an optomechanical system, or other system where one or more portions thereof may require adjustment of any of height, position, alignment, angle, etc. In an exemplary embodiment, rotational positional adjustment of the alignment tube 110 can be effected by applying torsion to the hexagonal head 116, e.g., by a wrench, or similar device, which accordingly provides a positional change of the flange 120. For example, the rotational position of the alignment tube 110 can be performed manually, whereby the position of the alignment tube 110 is changed to facilitate placement of the flange 120 at a desired location.
In another exemplary embodiment, the position of the alignment tube 110 and corresponding placement of the flange 120 (and accordingly the support 410) can be controlled by a computer-implemented system.
In an exemplary embodiment, the position sensor 620 can monitor the position of the flange 120 and/or the support 410, or a device 650 (e.g., an optical device) located thereon. Based on feedback received from the position sensor 620, the positioning component 610 can cause the drive component 630 to operate to change the rotational position of alignment tube 110, which, as previously described, effects a corresponding change in the position of the flange 120. The rotational position of the alignment tube 110 can be adjusted, until the position of the flange 120 (and/or the support 410 or the device 650) is determined by the positioning component 610 in conjunction with the position sensor 620 to be at the desired position. The drive component 630 can comprise suitable means to facilitate adjustment of the alignment tube 110, where such means can include a servo-motor, screw drive, and the like.
In a further exemplary embodiment, an external system 640 can provide instruction/feedback to the positioning component 610. For example, in the optical system mentioned herein, a beam of electromagnetic radiation can be directed through the optical system, whereby the device 650 may require a positional adjustment to effect a desired effect in the electromagnetic radiation, e.g., redirection of the beam, splitting of the beam, etc. The position to facilitate the desired effect is identified/determined by the external system 640. For example, a magnitude of beam splitting of the electromagnetic radiation may be increased and/or reduced by orientating the device 650 to a different position. The external system 640 can receive information regarding the magnitude of beam splitting and instruct the positioning component 610 to control operation of the drive component 630 to facilitate reducing or increasing the degree of beam splitting.
Due at least partially to the essentially loose/free coupling between the alignment assembly components, e.g., the alignment tube 110 and the alignment ball 130 in conjunction with the flange 120 (and the support 410) and the supporting bearings 140, a degree of change in the relative position of the one or more assemblies 401-403 can be accommodated.
In a conventional system, where various components providing positional adjustment are in a fixed location relative to each other, thermal expansion (e.g., of a supporting plate) can be problematic and difficult to accommodate. However, the assembly 700 can accommodate such thermal expansion. As illustrated, the bearings 712-713, the bearings 714-15, and the bearings 721-722 can be roller-type bearings, and thus can be aligned along their respective lengths to accommodate thermal expansion (e.g., of the support 410) whereby, owing to each of the alignment balls 130 being in free contact with the respective bearing pairs 712-713, 714-15, and 721-722, any of the alignment balls 130 can slide along their respective roller bearing pair while maintaining their associated flanges 120 at a desired height. As illustrated in
The various components comprising assemblies 100-700 can be constructed from any suitable material(s) to facilitate operation of the various embodiments presented herein. For example, any of the various components can be formed with a hardened steel such as alloy 400 series steel, alloy 51200 bearing steel, a ceramic, a polymer, a composite, or any combination thereof. Materials selection can be based on selecting a material that is not prone to surface distortion (e.g., dimpling) when placed under load in contact with another material, e.g., the alignment ball 130 should not undergo dimpling when placed on the bearing(s) 140.
At 820, for each aligning assembly, a support assembly can be formed to facilitate supporting the aligning assembly. A support assembly can comprise of a base into which are located a pair of bearings.
At 830, a flange comprising a threaded aperture is attached onto the alignment tube, wherein the threaded aperture has a diameter and thread pitch to fit the diameter and thread pitch of the alignment tube.
At 840, each alignment assembly can be located on its respective support assembly, e.g., the alignment ball for each alignment assembly is located on its respective support bearings.
At 850, with each alignment assembly positioned on its respective support assembly, the alignment tube can be rotated to facilitate adjustment of the height of the flange respectively attached to the alignment tube. As each alignment tube is rotationally adjusted, the height of the flange can be changed while any according tilt in a support plate associated with the flange is accommodated by an according tilt in the alignment tubes, which are not being rotationally adjusted but are free to be aligned on their respective support bearings. Rotation of the alignment tube can be by any suitable means, e.g., an external-drive structure, an internal-drive structure, or combination thereof. The methodology 800 completes at 855.
In an embodiment, the methodology 900 starts at 905, and at 910, a measurement is received regarding the current position of a device, for example the position of a lens relative to an optical axis. In an exemplary embodiment, the position of the device can be directly determined, for example, by a position measurement taken directly from a surface of the device, a surface of a plate or similar device supporting the device, position of a flange connecting the supporting plate to an alignment tube comprising the alignment assembly, or the like. In another embodiment, the measurement can be received from an external source. For example, in the previously mentioned optical system, a beam of electromagnetic radiation can be directed through the optical system and is incident on the surface of the device, passes through the device, undergoes beam splitting by the device, a quantity associated with the electromagnetic radiation is determined, etc. Based upon measurements regarding the interaction of the electromagnetic radiation and the device, an initial position of the device relative to the electromagnetic beam can be determined/inferred by an external component.
At 920, a determination can be made regarding the received measurement and a desired position of the device. In the event of the position being determined to be correct, the methodology 900 returns to 910 to await receipt of the next measurement regarding the position of the device.
If it is determined at 920 that the position is incorrect, at 930 a determination can be made regarding a distance to be moved to facilitate the device being placed in the required position. The distance can be of any movement, e.g., a linear displacement, a vertical displacement, a horizontal displacement, a vector displacement, an angular displacement, a rotational displacement, a combination of any of the foregoing, etc.
In an exemplary embodiment, the diameter of the aligning tube, associated thread diameter (any of major diameter, minor diameter, average pitch diameter, pitch diameter), thread pitch, current angle of an aligning tube, position of supporting base, position of a supporting flange, etc., can be known. Based thereon, it is possible to determine an angle of revolution of the aligning tube to facilitate placing the device at the desired position. For example, where a combination of thread pitch and thread diameter is configured such that a 1° of rotation of the aligning tube results in a corresponding change of 0.010″ (or 10 mils) in position of the height of the device, the aligning tube can be turned through 10° to facilitate moving the device 0.1″ (or 100 mils). In an exemplary embodiment, such determination can be performed by a manual operation.
In another embodiment, whereby the computer-based system comprises a processor(s), memory, etc., the determination(s) can be performed by the processor(s) executing instructions relating to adjustment of position of the aligning tube (and corresponding positional change of the device, flange, supporting structure, etc.), wherein the determinations can be performed in conjunction with one or more lookup tables pertaining to such parameters as the diameter of the aligning tube, associated thread diameter (any of major diameter, minor diameter, average pitch diameter, pitch diameter), thread pitch, current angle of an aligning tube, position of supporting component, position of a supporting flange, etc. At 940, an instruction is forwarded to a drive component, wherein the instruction relates to a degree of rotation required to effect a change in the height of the device. Optionally, the methodology 900 can return to 920, where again a determination is made regarding whether the device position is correct. The methodology 900 completes at 945.
In another embodiment, the methodology 1000 starts at 1005, and at 1010, a determination can be made regarding aligning a plurality of bearings to facilitate compensation of thermal expansion of the optical apparatus. The determination can be made with regard to various pertinent parameters such as the distance between the respective bearing pairings, an anticipated magnitude of thermal expansion (e.g., based on materials utilized, operating temperatures, change in operating temperatures), or the like.
At 1020, a support assembly can be constructed, wherein the bearings are aligned at the determined angle(s).
At 1030, an operating assembly (e.g., the optical apparatus, aligning assembly, etc.) comprising one or more aligning assemblies can be located onto the support assembly, wherein in an initial condition the various aligning assemblies are located on their respective bearing pairs.
At 1040, operation of the optical apparatus is undertaken, whereby during the operation, a device (e.g., such as a beam splitter, a gas cell, a lens, a mirror, etc.) may undergo heating which can give rise to thermal expansion of the component, or associated component (e.g., a support assembly).
At 1050, based upon the free coupling between an aligning assembly and its associated bearing pair, the aligning assembly (e.g., the ball comprising the aligning assembly) is free to move along the associated bearing pair and thus the thermal expansion resulting from operation of the optical apparatus can be accommodated by the combination of the aligning assembly and associated pair of bearings. The methodology 1000 completes at 1055.
At 1120, the fastener can be tightened into the aperture in the base, thereby causing the spherical washers to be pressed against the stepped structure, and thus causing the aligning ball (and accordingly the aligning tube and any connected structure such as a supporting plate) to become locked in place against the two or more bearings. The aligning tube does not have to be aligned perpendicular to the base, thereby enabling a tilted aligning tube (e.g., titled as a result of aligning a supporting plate and/or an associated component) to be secured without loss of the angle of tilt.
At 1130, a previously tightened fastener can be un-tightened in the aperture in the base, thereby causing the spherical washers to be loosened against the stepped structure, and thus causing the aligning ball (and accordingly the aligning tube and any connected structure such as a supporting plate) to become unlocked against the two or more bearings. By unlocking the fastener (which, along with the spherical washers can be subsequently removed), the aligning assembly (e.g., comprising the aligning tube and aligning ball) is free to move to facilitate subsequent adjustment of a component in an optical system as previously described. The methodology 1100 completes at 1135.
Referring now to
The computing device 1200 additionally includes a data store 1208 that is accessible by the processor 1202 by way of the system bus 1206. The data store 1208 may include executable instructions, operating parameters, required operating parameters, etc. The computing device 1200 also includes an input interface 1210 that allows external devices to communicate with the computing device 1200. For instance, the input interface 810 may be used to receive instructions from an external computer device, from a user, etc. The computing device 1200 also includes an output interface 1212 that interfaces the computing device 1200 with one or more external devices. For example, the computing device 1200 may display text, images, etc. by way of the output interface 1212.
Additionally, while illustrated as a single system, it is to be understood that the computing device 1200 may be a distributed system. Thus, for instance, several devices may be in communication by way of a network connection and may collectively perform tasks described as being performed by the computing device 1200.
As used herein, the terms “component” and “system” are intended to encompass computer-readable data storage that is configured with computer-executable instructions that cause certain functionality to be performed when executed by a processor. The computer-executable instructions may include a routine, a function, or the like. It is also to be understood that a component or system may be localized on a single device or distributed across several devices.
Various functions described herein can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer-readable storage media. A computer-readable storage media can be any available storage media that can be accessed by a computer. By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc (BD), where disks usually reproduce data magnetically and discs usually reproduce data optically with lasers. Further, a propagated signal is not included within the scope of computer-readable storage media. Computer-readable media also includes communication media including any medium that facilitates transfer of a computer program from one place to another. A connection, for instance, can be a communication medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave are included in the definition of communication medium. Combinations of the above should also be included within the scope of computer-readable media.
The term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.
What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable modification and alteration of the above structures or methodologies for purposes of describing the aforementioned aspects, but one of ordinary skill in the art can recognize that many further modifications and permutations of various aspects are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the details description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
This application claims priority to U.S. Provisional Patent Application No. 61/691,164, filed on Aug. 20, 2012, entitled “ADJUSTABLE KINEMATIC MOUNTS”, the entirety of which is incorporated herein by reference.
This invention was developed under contract DE-AC04-94AL85000 between Sandia Corporation and the U.S. Department of Energy. The U.S. Government has certain rights in this invention.
Number | Date | Country | |
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61691164 | Aug 2012 | US |