FIELD OF THE INVENTION

[0001] This disclosure relates generally to apparatus and methods for suppressing oscillations of an oscillating body.

BACKGROUND

[0002] An unwanted oscillation is a periodic (e.g. reciprocating) movement exhibited by a body (e.g. person or device), which has a negative (e.g. detrimental) impact, such as for example a loss of accuracy, control, or stability. Suppressing (i.e. reducing) the unwanted oscillation may mitigate the negative impact.

SUMMARY

[0003] In one aspect, an apparatus for suppressing oscillations of an oscillating body is provided. The apparatus may include a magnetic housing and a magnetic stabilizing mass. The magnetic housing may be securable to the oscillating body. The magnetic housing may define a housing interior. The magnetic stabilizing mass may be slideably coupled to the magnetic housing in the housing interior by a bearing assembly. The magnetic stabilizing mass may be slideable between a first position and a second position. The magnetic stabilizing mass may have an equilibrium position between the first position and the second position. The magnetic housing may produce magnetic fields that magnetically repel the magnetic stabilizing mass away from the first position at least when the magnetic stabilizing mass is offset from the equilibrium position toward the first position, and that magnetically repel the magnetic stabilizing mass away from the second position at least when the magnetic stabilizing mass is offset from the equilibrium position toward the second position.

[0004] In another aspect, a method of suppressing oscillations of an oscillating body is provided. The method may include securing a magnetic housing to the oscillating body, the magnetic housing containing a magnetic stabilizing mass slideable between a first position and a second position through an equilibrium position; and in response to an oscillation of the oscillating body, the secured magnetic housing magnetically repelling the magnetic stabilizing mass away from the first position and second positions toward the equilibrium position, suppressing the oscillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a perspective view of an apparatus for suppressing oscillation, in accordance with an embodiment;

[0006] FIG. 2 is a perspective view of the apparatus of FIG. 1 , with a magnetic field shield removed;

[0007] FIG. 3 is an exploded view of the apparatus of FIG. 1 ;

[0008] FIG. 4A is a perspective view of an apparatus for suppressing oscillations with a magnetic stabilizing mass in a first position, in accordance with another embodiment;

[0009] FIG. 4B is a perspective view of the apparatus of FIG. 4A with the magnetic stabilizing mass in an equilibrium position;

[0010] FIG. 4C is a perspective view of the apparatus of FIG. 4A with the magnetic stabilizing mass in a second position;

[001 1] FIG. 5A is a top plan view of the apparatus of FIG. 4A with the magnetic stabilizing mass in the first position;

[0012] FIG. 5B is a top plan view of the apparatus of FIG. 4A with the magnetic stabilizing mass in the equilibrium position;

[0013] FIG. 5C is a top plan view of the apparatus of FIG. 4A with the magnetic stabilizing mass in the second position;

[0014] FIG. 6 is a perspective view of an apparatus for suppressing oscillations in accordance with another embodiment;

[0015] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6;

[0016] FIG. 8 is a top plan view of an apparatus for suppressing oscillations in accordance with another embodiment;

[0017] FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 8;

[0018] FIG. 10 shows an apparatus for suppressing oscillation mounted to a user, in accordance with an embodiment;

[0019] FIG. 1 1 shows an apparatus for suppressing oscillation mounted to a 3D printer print head, in accordance with an embodiment; [0020] FIG. 12 shows an apparatus for suppressing oscillation mounted to a clothing washing machine, in accordance with an embodiment;

[0021] FIG. 13 shows an apparatus for suppressing oscillation mounted to a clothing dryer, in accordance with an embodiment;

[0022] FIG. 14 shows an apparatus for suppressing oscillation mounted to a robotic arm, in accordance with an embodiment;

[0023] FIG. 15 shows an apparatus for suppressing oscillation mounted to a camera, in accordance with an embodiment; and

[0024] FIG. 16 shows an apparatus for suppressing oscillation mounted to a firearm, in accordance with an embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0025] Numerous embodiments are described in this application, and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any sense. The invention is widely applicable to numerous embodiments, as is readily apparent from the disclosure herein. Those skilled in the art will recognize that the present invention may be practiced with modification and alteration without departing from the teachings disclosed herein. Although particular features of the present invention may be described with reference to one or more particular embodiments or figures, it should be understood that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described.

[0026] The terms "an embodiment," "embodiment," "embodiments," "the embodiment," "the embodiments," "one or more embodiments," "some embodiments," and "one embodiment" mean "one or more (but not all) embodiments of the present invention(s)," unless expressly specified otherwise.

[0027] The terms "including," "comprising" and variations thereof mean "including but not limited to," unless expressly specified otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a," "an" and "the" mean "one or more," unless expressly specified otherwise. [0028] As used herein and in the claims, two or more parts are said to be “coupled”,“connected”,“attached”,“joined” or“fastened” where the parts are joined or operate together either directly or indirectly (i.e., through one or more intermediate parts), so long as a link occurs. As used herein and in the claims, two or more parts are said to be“directly coupled”,“directly connected”,“directly attached”,“directly joined”, or “directly fastened” where the parts are connected in physical contact with each other. As used herein, two or more parts are said to be“rigidly coupled”,“rigidly connected”, “rigidly attached”,“rigidly joined”, or“rigidly fastened” where the parts are coupled so as to move as one while maintaining a constant orientation relative to each other. None of the terms“coupled”, “connected”, “attached”, “joined”, and“fastened” distinguish the manner in which two or more parts are joined together, unless specifically stated otherwise.

[0029] As used herein and in the claims, a first element is said to be“received” in a second element where at least a portion of the first element is received in the second element unless specifically stated otherwise.

[0030] As used herein and in the claims, a first element is said to be“transverse” to a second element where the elements are oriented within 45 degrees of perpendicular to each other.

[0031] Further, although method steps may be described (in the disclosure and / or in the claims) in a sequential order, such methods may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of methods described herein may be performed in any order that is practical. Further, some steps may be performed simultaneously.

[0032] As used herein and in the claims, a group of elements are said to ‘collectively’ perform an act where that act is performed by any one of the elements in the group, or performed cooperatively by two or more (or all) elements in the group.

[0033] Some elements herein may be identified by a part number, which is composed of a base number followed by an alphabetical or subscript-numerical suffix (e.g. 1 12a, or 1 12i). Multiple elements herein may be identified by part numbers that share a base number in common and that differ by their suffixes (e.g. 1 12i, 1 122, and 1 123). All elements with a common base number may be referred to collectively or generically using the base number without a suffix (e.g. 1 12).

[0034] Unwanted oscillations can present challenges in a wide variety of applications. For example, the oscillations of a 3D printer print head during 3D printing can reduce the accuracy of the printed object. Similarly, the oscillations of a robotic arm in a manufacturing process can create manufacturing defects. Other oscillating bodies that produce unwanted oscillations include for example, home appliances (e.g. clothing washing machines and clothing dryers), and high-rise structures (i.e. tall buildings).

[0035] Furthermore, a portion of the world’s population suffers from involuntary hand or forearm oscillations such as hand or elbow tremors. Depending on severity, involuntary hand motions may impede daily activities and reduce quality of life of the persons experiencing the involuntary motions. Involuntary hand and forearms motions may involve rhythmic muscle movement resulting in hand or forearm oscillation. Involuntary hand and forearm motions may be associated with Parkinson’s disease and Essential Tremor. A person suffering from involuntary forearm tremors may impart their tremor to a device they are holding. For example, if the person suffering from forearm tremors is operating a camera, their tremors may be imparted to the camera and may lead to a shaky video recording or a blurry photo capture.

[0036] Embodiments disclosed herein relate to devices that may be secured to an oscillating body (e.g. such as those noted above) for the purpose of suppressing the oscillation’s amplitude, and thereby lessening the negative impacts associated with the oscillation. In some aspects, the devices may have characteristics of a“damper” in that they dampen (also referred to as suppressing) oscillation amplitude.

[0037] At a high level, dampers may be classified as either tuned or broadband mass dampers. A tuned mass damper may include a mass, viscous damping fluid, and spring, which are collectively tuned to eliminate a single oscillation frequency. In a tuned mass damper, the stabilizing mass is configured to move 90 degrees out-of-phase with the oscillating body’s motion at the single oscillation frequency. To target a different oscillation frequency, the mass, damping fluid, and spring combinations require reconfiguration.

[0038] Embodiments disclosed herein relate to a device having characteristics of a broadband mass damper. In contrast with a tuned mass damper, a broadband mass damper can absorb a spectrum of unwanted oscillations of an oscillating body, which fall within a wide frequency range (i.e. multi-frequency oscillation suppression). Accordingly, broadband mass dampers may be described as having a large stabilization bandwidth.

[0039] In one aspect, tuned mass dampers may differ from broadband mass dampers by their characteristic oscillating body mass to stabilizing mass ratio (also referred to as the‘damper mass ratio’). Tuned mass dampers may have a damper mass ratio of at least 20 to 1 , and broadband mass dampers typically may have lesser mass ratio of at least 5 to 1. Other damper mass ratios are possible.

[0040] A mass damper, whether tuned or broadband, may be active or passive. An active damper is one in which powered actuators are used to generate forces that attenuate the targeted oscillation. Drawbacks of activate dampers include power requirements, high cost, large size, and complexity.

[0041] A passive damper is a device that operates without a power source (e.g. operates without electrical power). Passive dampers produce reactionary forces in response to an oscillation. Advantages of passive systems may include lower cost, simplicity, and no power requirements.

[0042] Dampers may employ a configuration of springs and/or viscous damping liquid to provide spring and damping coefficients that target unwanted oscillations. However, the use of springs and damping liquid has numerous drawbacks. First, dampers containing viscous damping liquid can be very expensive, difficult to customize for a targeted object and oscillation, require regular maintenance to avoid leaks, and have a fixed damping coefficient.

[0043] Second, springs have a limited life cycle that is difficult to determine. Theoretical calculations of spring life cycles have a wide margin of error. This is because a spring’s life may be impacted greatly by environment, temperature, travel, impacts, and surface treatment. Also, spring design for dampers may require significant trial and error to achieve the targeted spring coefficient for the intended application.

[0044] Embodiments disclosed herein are directed to an apparatus having characteristics of a passive broadband mass damper, and related methods. The apparatus suppresses oscillations magnetically. This may avoid the use of springs and damping liquid, and their associated drawbacks. The apparatus is passive, and thus requires no power source (e.g. no batteries, and no power connections). At a high level, the apparatus includes a magnetic stabilizing mass located in a magnetic housing. The relative magnetism of the stabilizing mass and housing produces magnetic repelling forces that resist the stabilizing mass’ movement in reaction to the connected body’s oscillation. This reduces the oscillation amplitude of the connected body within an oscillation frequency bandwidth. It will be appreciated that the dynamic properties of the magnetic repelling forces differ fundamentally from spring and viscous liquid systems, which are characterized by a stiffness (i.e. spring) coefficient and a damping coefficient.

[0045] Referring to FIGS. 1-3, an oscillation suppression apparatus 100 is shown in accordance with an embodiment. As shown, apparatus 100 includes a magnetic housing 104 and a magnetic stabilizing mass 108. Magnetic housing 104 may be attached to a body that exhibits oscillations targeted for suppression. In the example shown, magnetic housing 104 defines an interior 1 12, and magnetic stabilizing mass 108 is slideably coupled to magnetic housing 104 in housing interior 1 12.

[0046] As used herein and in the claims, the adjective“magnetic” as used in connection with housing 104 and stabilizing mass 108, means that these elements emit a magnetic field, and are not simply attractable by magnetic fields (e.g. as in ferromagnetic materials). For example, each of magnetic housing 104 and magnetic stabilizing mass 108 includes (or is composed entirely of) one or more magnets (e.g. permanent magnets).

[0047] In use, magnetic housing 104 is rigidly attached to an oscillating body (e.g. a user’s forearm) whereby the magnetic housing 104 and the oscillating body move together as one. The magnetic stabilizing mass 108 slides relative to magnetic housing 104 in reaction to oscillatory movement of the oscillating body (and the rigidly attached magnetic housing 104). This movement brings opposing magnetic fields of the magnetic stabilizing mass 108 and magnetic housing 104 into interactions which create magnetic repelling forces that are out of phase with the body’s oscillation, and thereby suppresses (i.e. reduces the amplitude of) the oscillation.

[0048] As used herein and in the claims, references to“sliding” or“slideably” or “slides” mean to move smoothly, and do not imply continuous physical contact. For example, a body may slide relative to another body by smoothly gliding, rolling, hovering, or running along a rail or track.

[0049] FIGS. 4A-C and 5A-C illustrate exemplary movements of a magnetic stabilizing mass 108 that is slideably coupled to magnetic housing 104 in a manner that allows (e.g. constrains) the magnetic stabilizing mass 108 to sliding along a linear path 1 16, between a first position 120i and a second position 1202. An equilibrium position 1203 is located between the first and second positions 120i and 1203. A first direction 124i (also referred to as a forward direction 124i) is defined by a vector oriented from equilibrium position 1203 towards first position 120i, and a second direction 1242 (also referred to as a rearward direction 1242) is defined by a vector oriented from equilibrium position 1203 towards second position 1202.

[0050] As shown by comparison of FIGS. 4B and 5B to FIGS. 4A and 5A, when magnetic housing 104 (rigidly connected to the oscillating body) moves in second direction 1242, magnetic stabilizing mass 108 effectively moves relative to magnetic housing 104 in the first direction 124i towards first position 120i. As magnetic stabilizing mass 108 moves away from equilibrium position 1203 towards first position 120i, magnetic repulsion forces develop between magnetic stabilizing mass 108 and magnetic housing 104 which (i) urge the magnetic stabilizing mass 108 to move towards the equilibrium position 1203 (i.e. to move in the second direction 1242 relative to magnetic housing 104), and (ii) urge the magnetic housing 104 to move in the first direction 124i (i.e. in opposition to the oscillation). The result is that the oscillation amplitude in the second direction 1242 is reduced.

[0051] Referring to FIGS. 4B and 5B, and FIGS. 4C and 5C, a corresponding opposite behavior is exhibited when the body’s oscillation moves the magnetic housing 104 in the first direction 124i. Magnetic stabilizing mass 108 effectively moves relative to magnetic housing 104 in the second direction 1242 towards second position 1202. As magnetic stabilizing mass 108 moves away from equilibrium position 1203 towards second position 1202, magnetic repulsion forces develop between magnetic stabilizing mass 108 and magnetic housing 104 which (i) urge the magnetic stabilizing mass 108 to move towards the equilibrium position 1203 (i.e. to move in the first direction 124i relative to magnetic housing 104), and (ii) urge the magnetic housing 104 to move in the second direction 1242 (i.e. in opposition to the oscillation). The result is that the oscillation amplitude in the first direction 124i is reduced.

[0052] Thus, in use apparatus 100 reduces oscillation amplitudes in both directions 124i and 1242 (i.e. suppresses the oscillation) using magnetic repulsion forces between magnetic housing 104 and magnetic stabilizing mass 108.

[0053] Returning to FIG. 2, magnetic stabilizing mass 108 may be mounted to magnetic housing 104 in magnetic housing interior 1 12 in any manner that allows magnetic stabilizing mass 108 to slide relative to magnetic housing 104 in response to oscillations of the connected body. In the example shown, magnetic stabilizing mass 108 is slideably coupled to magnetic housing 104 in a manner that constrains magnetic stabilizing mass 108 to movement along a straight linear path. As used herein, a “linear” path (also referred to as a‘one dimensional’ path) is one composed of a singular line (e.g. having no branches), which may be straight as illustrated or curved.

[0054] As shown, magnetic stabilizing mass 108 may be mounted to magnetic housing 104 by a bearing assembly 128 that reduces frictional resistance to movement between magnetic stabilizing mass 108 and magnetic housing 104. Bearing assembly 128 may be any device that acts to support stabilizing mass 108 within magnetic housing interior 1 12. In some embodiments, bearing assembly 128 may guide (e.g. constrain) magnetic stabilizing mass 108 to move along linear path 1 16.

[0055] Turning to FIG. 3, in some embodiments, bearing assembly 128 may include, for example one or more (or all) of tracks, guide rails, roller bearings, ball bearings, bushings, drawer slides, wheels, or similar friction mitigating mechanical devices. Preferably, bearing assembly 128 provides an effective coefficient of friction (static and dynamic) of less than 0.2 (i.e. friction force during sliding movement of magnetic stabilizing mass 108, relative to magnetic housing 104 along linear path 1 16, is less than 20% of the weight of the magnetic stabilizing mass 108). In some embodiments, bearing assembly 128 may suspend magnetic stabilizing mass 108 within magnetic housing 104 (i.e. out of contact with magnetic housing 104), which may further reduce friction during sliding.

[0056] By reducing friction, magnetic stabilizing mass 108 can move freely along linear path 1 16 in reaction to oscillatory movements of magnetic housing 104. As described above, the relative movement of magnetic stabilizing mass 108 away from equilibrium position 1203 is responsible for bringing the magnetic fields of magnetic housing 104 and magnetic stabilizing mass 108 into an interactive proximity that creates the repulsive forces, which oppose the oscillatory movements of the magnetic housing 104 (and connected body).

[0057] Still referring to FIG. 3, the illustrated bearing assembly 128 includes guide rails 132 that suspend magnetic stabilizing mass 108 within magnetic housing interior 1 12, and constrain magnetic stabilizing mass 108 to a straight linear path. As shown, magnetic housing 104 includes a base 136 (e.g. which may be mounted, in contact with or facing, an oscillating body) and sidewalls 140 that extend upward from base 136. Magnetic housing sidewalls 140 may define a magnetic housing front end 144i (also referred as magnetic housing first end 144i) and an opposed magnetic housing rear end 1442 (also referred as magnetic housing second end 1442). For example, magnetic housing 104 may include a front sidewall 140i (also referred to as first sidewall 140i) at magnetic housing front end 144i, and a rear sidewall 1402 (also referred to as second sidewall MO2) at magnetic housing rear end 1442. Guide rails 132 may extend between magnetic housing front and rear ends 144i and 1442. For example, each guide rail 132 may be connected to magnetic housing front sidewall 140i and to magnetic housing rear sidewall 1402.

[0058] Magnetic stabilizing mass 108 may be mounted to guide rails 132 in any manner that allows magnetic stabilizing mass 108 to move along guide rails 132 with little friction. For example, magnetic stabilizing mass 108 may be mounted to guide rails 132 by one or more friction mitigating members 148, which may include a bushing (e.g. Teflon sleeve or oil impregnated sleeve), roller bearing, or ball bearing. In use, magnetic stabilizing mass 108 slides along guide rails 132 between the first and second positions 120i and 1202.

[0059] Apparatus 100 may include any number of guide rails 132. In the illustrated example, two guide rails 132 are shown. In other embodiments, there may be just one guide rail 132 (e.g. to simplify the design and reduce cost), or there may be three or more guide rails 132 (e.g. to provide greater support and stability for magnetic stabilizing mass 108). Guide rails 132 may extend through apertures 152 in magnetic stabilizing mass 108 as shown, or guide rails 132 may be located externally to magnetic stabilizing mass 108. [0060] Guide rails 132 may be made of any material with sufficient strength and rigidity to support magnetic stabilizing mass 108 without substantial deflection. For example, guide rails 132 may be made of metal (e.g. aluminum or steel). A lightweight metal (e.g. having a density of less than 4g/cm ³ ), such as aluminum, may provide the required strength without adding substantially to the weight of apparatus 100. A reduction in weight may reduce the burden of apparatus on the user where apparatus 100 is carried by the user (e.g. attached to their forearm, or attached to an object carried by the user).

[0061] Reference is now made to FIGS. 6-7. In some embodiments, magnetic stabilizing mass 108 may be movable along a curved (e.g. arcuate) path within magnetic housing 104. The illustrated example shows a magnetic stabilizing mass 108 slideably coupled to magnetic housing 104 in a manner that constrains magnetic stabilizing mass 108 to a curved linear path. In general, apparatus 100 may be more effective at suppressing oscillations where the movement path of the magnetic stabilizing mass 108 more closely matches the directionality of the oscillation. Accordingly, an apparatus 100 having a curved linear movement path 1 16 as shown may provide greater suppression to oscillations having a similarly curved (e.g. arcuate or rotating) directionality, as compared to a straight linear movement path all else being equal.

[0062] As shown, curved linear path 1 16 may curve from equilibrium position 1203 downwardly (e.g. towards the oscillating body to which apparatus 100 is mounted) to first and second positions 120i and 1202. A curved linear path 116 may have a radius of curvature of between 1 cm and 100cm for example, which may be selected according to the characteristics of the oscillations targeted for suppression.

[0063] As used herein, magnetic stabilizing mass 108 is said to be“in” or“within” magnetic housing interior 1 12 where at least a portion (or all) of magnetic stabilizing mass 108 is inside magnetic housing interior 1 12. For example, a portion of magnetic stabilizing mass 108 may extend outside of magnetic housing interior 1 12.

[0064] Turning to FIG. 2, each of magnetic housing 104 and magnetic stabilizing mass 108 may be composed of, or include, any configuration of magnet(s) that generate repulsion forces which oppose oscillatory movements of the magnetic housing 104. For example, each of magnetic housing 104 and magnetic stabilizing mass 108 may include one or more discrete magnets. In the illustrated example, magnetic housing 104 includes first and second housing magnets 156i and 1562 (also referred to as front and rear housing magnets 156i and 1562), and magnetic stabilizing mass 108 includes first and second stabilizing mass magnets 160i and 1602 (also referred to as front and rear stabilizing mass magnets I6O1 and I6O2). In alternative embodiments, any one or more (or all) of magnets 156 and 160 may be substituted by two or more magnets (e.g. there may be two or three front housing magnets 156i).

[0065] Referring to FIGS. 5A-C, in the illustrated example, first magnets 156i and I6O1 are positioned and oriented to generate together a repelling force when magnetic stabilizing mass 108 is offset from equilibrium position 1203 towards first position 120i, and second magnets 1562 and I6O2 are positioned and oriented to generate together a repelling force when magnetic stabilizing mass 108 is offset from equilibrium position 1203 towards second position 1202. As shown, magnets 156 and 160 are positioned so that as magnetic stabilizing mass 108 moves away from equilibrium position 1203 towards first position 120i, a distance between first magnets 156i and I6O1 decreases and a distance between second magnets 1562 and I6O2 increases; and as magnetic stabilizing mass 108 moves away from equilibrium position 1203 towards second position 1202, a distance between first magnets 1562 and I6O2 decreases and a distance between first magnets 156i and I6O1 increases.

[0066] A magnet’s orientation may be described by reference to their North and South magnetic poles. When the same pole (e.g. both North or both South) of two magnets are brought into proximity to each other, the magnetic fields of those magnets produce a magnetic repelling force that urges the magnets to separate (as opposed to an attractive force that urges the magnet to come together). First magnets 156i and I6O1 may be oriented so that they generate a repulsive force when moved toward each other; and second magnets 1562 and I 6O2 may be oriented so that they generate a repulsive force when moved toward each other. For example, first housing magnet 156i may be oriented with a first pole facing in the second direction 1242 (e.g. rearward) and first stabilizing mass magnet I 6O1 may be oriented with a first pole facing in the first direction 124i (e.g. forward), and both first poles may be the same (e.g. both North or both South). Similarly, second housing magnet 1562 may be oriented with a first pole facing in the first direction 124i (e.g. forward) and second stabilizing mass magnet I6O2 may be oriented with a first pole facing in the second direction 1242 (e.g. rearward), and both first poles may be the same (e.g. both North or both South).

[0067] As shown, first housing magnet 156i may be located at magnetic housing front end 144i (e.g. connected to magnetic housing front sidewall 140i) proximate first position 120i, and second housing magnet 1562 may be located at magnetic housing rear end 1442 (e.g. connected to magnetic housing rear sidewall MO2) proximate second position 1202. First stabilizing mass magnet I6O1 may be positioned at magnetic stabilizing mass front end 164i, and second stabilizing mass I6O2 may be positioned at magnetic stabilizing mass rear end 1642, as shown. As exemplified, the housing and mass stabilization magnets 156 and 160 may be longitudinally aligned along a line parallel to path 1 16. Such alignment may provide a symmetry that may simplify the design. In alternative embodiments, one or more (or all) of magnets 156 and 160 may be offset from a line parallel to path 1 16. Such misaligned may provide flexibility to better target certain oscillations for suppression.

[0068] Reference is now made to FIGS. 8-9. In some embodiments, magnetic housing 104 may include just one housing magnet 156 (i.e. instead of two or more housing magnets 156). Alternatively or in addition, magnetic stabilizing mass 108 may include just one stabilizing mass magnet 160 (i.e. instead of two or more stabilizing mass magnets 160). The illustrated embodiment is an example of an apparatus 100 that includes just one housing magnet 156 and just one stabilizing mass magnet 160. In this example, magnets 156 and 160 may be shaped, positioned, and oriented to produce the repelling forces described above when magnetic stabilizing mass 108 is offset from equilibrium position 1203 towards the first and second positions 120i and 1202. For example, a front portion 1681 (also referred to as a first portion 1681) of housing magnet 156 at magnetic housing front end 144i may define a first pole, and a rear portion 1682 (also referred to as a second portion 1682) of housing magnet 156 at magnetic housing rear end 1442 may define a second pole. Stabilizing mass magnet 160 may have first and second poles at respective front and rear ends 164i and 1642 of magnetic stabilizing mass 108. The first poles of magnetic housing 104 and magnetic stabilizing mass 108 may be the same (e.g. both North or both South), and the second poles of magnetic housing 104 and magnetic stabilizing mass 108 may be the same (e.g. both South or both North), whereby the repelling forces described above for suppressing oscillations may be produced.

[0069] Referring to FIG. 3, magnets 156 and 160 may be permanent magnets. As compared with electromagnets, permanent magnets do not require electrical power to emit a magnetic field, and therefore do not require apparatus 100 to include a battery or power connection. As compared with temporary magnets, permanent magnets retain their magnetic intensity nearly indefinitely (typically 10 years or more). In preferred embodiments, magnets 156 and 160 are rare earth magnets, such as for example neodymium magnets. Advantageously, rare earth magnets are characterized by a long life cycle (i.e. before an appreciable loss of magnetism), low manufacturing cost, high magnetic field strength to mass ratio, and high magnetic field strength to volume ratio.

[0070] Referring to FIGS. 5A-5C, the magnetic repelling force generated by opposing magnetic fields increases as the distance between the magnets 156 and 160 decreases. Without being limited by theory, it is approximated that the repelling force is inversely proportional to a distance between the magnets 156 and 160, squared. Consequently, magnets 156 and 160 in apparatus 100 will generate greater repelling forces in response to stronger oscillations that cause the magnetic stabilizing mass 108 to move faster and therefor further away from the equilibrium position 1203 towards the first and second positions 120i and 1202.

[0071] For better vibration suppression, it is preferred that the magnetic stabilizing mass 108 be permitted to develop an initial acceleration with minimal resistance (i.e. minimal magnetic and frictional resistance). This is because apparatus 100 relies upon the movement of magnetic stabilizing mass 108 away from equilibrium position 1203 towards the first and second positions 120i and 1202 in order to produce the out-of-phase repelling forces that suppress the targeted oscillations. Accordingly, when magnetic stabilizing mass 108 is located at equilibrium position 1203, the repelling forces between magnets 156 and 160 should be small (or even effectively zero) so that magnetic stabilizing mass 108 may accelerate substantially unencumbered.

[0072] Equilibrium position 1203 is the position at which magnetic stabilizing mass 108 settles when apparatus 100 is at rest (i.e. not oscillating). At equilibrium position 1203, forward and rearward repelling forces (if any) acting upon magnetic stabilizing mass 108 are equal. Each of the forward and rearward repelling forces acting upon magnetic stabilizing mass 108 at equilibrium position 1203 may be less than 5% (i.e. 0% to 5%) of the weight of magnetic stabilizing mass 108. In the illustrated example, equilibrium position 1203 is located at a midpoint along linear path 1 16 between first and second positions 120i and 1202. In alternative embodiments, equilibrium position 1203 is instead located closer to one of the first or second positions 120 than the other. This may be due to the shape of linear path 116, or the relative strengths of different magnets among magnets 156 and 160. For example, in various embodiments, magnets 156i and 1562 may have the same or different strength, and magnets I 6O1 and I6O2 may have the same or different strength.

[0073] Reference is now made to FIGS. 10-16, which show an apparatus 100 attached to a variety of different oscillating bodies 172.

[0074] In FIG. 10, apparatus 100 is rigidly connected to an oscillating body 172 that is a user’s arm. In this application, apparatus 100 may help to suppress involuntary arm tremors, such as tremors caused by Parkinson’s disease or Essential Tremor. As shown, apparatus 100 may be connected to oscillating body 172 by a mounting member 208. In various embodiments and applications, mounting member 208 may be an arm strap as shown, a rope/cable/cord, a sleeve/sheath, adhesive, a fastener (e.g. screw, bolt, nail, or rivet), welds, or hook and loop fastener (e.g. Velcro™) for example. In some embodiments, apparatus 100 may be permanently connected to the oscillating body 172, and in other embodiments apparatus 100 may be removably connected to the oscillating body 172.

[0075] In FIG. 1 1 , apparatus 100 is rigidly connected to an oscillating body 172 that is a 3D printer print head (e.g. print head of an FDM 3D printer). In this application, apparatus 100 may help to suppress oscillations of the print head 172 that may occur during printing operations. For example, 3D printer print heads 172 are known to experience an oscillation known as“ringing” when the print head 172 changes direction sharply, which results in rippled print surfaces. Thus, by suppressing oscillations of print head 172, apparatus 100 may contribute to better quality 3D prints.

[0076] In FIGS. 12-13, apparatus 100 is rigidly connected to an oscillating body 172 that is a home appliance (e.g. the clothing washing machine 172 of FIG. 12, or the clothing dryer 172 of FIG. 13). Rotating drums within washing machines and dryers produce oscillations, which can generate noise and in some cases cause damage to the appliance. Thus, by suppressing oscillations of home appliances 172, apparatus 100 may help reduce noise and mitigate damage to the appliances 172.

[0077] In FIG. 14, apparatus 100 is rigidly connected to an oscillating body 172 that is a robotic arm. Arm segments 176 of a robotic arm 172 may experience oscillations during programmed movements due to their cantilevered configuration, which may reduce movement and positional accuracies. Thus, by suppressing oscillations of robotic arm 172, apparatus 100 may contribute to better movement and positional accuracies of robotic arm 172.

[0078] In FIGS. 15 and 16, apparatus 100 is rigidly connected to an oscillating body 172 that is a handheld article (a camera in FIG. 15, and a firearm in FIG. 16). In this case, when a user grasps the handheld article, it is the user that imparts oscillations upon the handheld article 172, and which characterizes the article as an oscillating body. For example, users of cameras and firearms 172 (i.e. photographers and hunters) practice various techniques to reduce shake upon the camera or firearm 172, in order to avoid a blurry image (or shaky video recording) or inaccurate shot. Apparatus 100 when affixed to a handheld article 172 (e.g. the camera of FIG. 15 or the firearm of FIG. 16) may be effective for suppressing oscillations imparted to that handheld article 172 by the user. In the context of cameras and firearms 172, this may help to produce a clearer image (or more still video recording) or more accurate shot.

[0079] For many applications, including for example the applications noted above, apparatus 100 may be configured to provide suppression for oscillation frequencies in a range of 1 -20 Hz, or in a range of 10-50 kHz. To suppress oscillation frequencies in both frequency ranges, two apparatus 100 may be connected to the same oscillating body. In alternative embodiments, apparatus 100 may be configured to provide oscillation suppression for oscillation frequencies outside of these ranges.

[0080] As described above, the damper mass ratio (i.e. ratio of oscillating body mass to mass of magnetic stabilizing mass) may be at least 5: 1 in many embodiments. The following are non-limiting examples of the mass of magnetic stabilizing mass 108 in various applications. In FIG. 10, magnetic stabilizing mass 108 may be 0.1 kg to 1 kg; in FIG. 11 , magnetic stabilizing mass may be 0.02kg to 0.2kg; in FIGS. 12-13, magnetic stabilizing mass 108 may be 2kg to 20kg; in FIG. 14, magnetic stabilizing mass 108 may be 0.3kg to 3kg; in FIG. 15, magnetic stabilizing mass 108 may be 0.05kg to 0.5kg; and in FIG. 16, magnetic mass may be 0.06kg to 0.6kg.

[0081] Returning to FIG. 2, magnetic stabilizing mass 108 may be made of any materials that can provide an overall density suitable for providing the required weight in an acceptable volume. In some embodiments, magnetic stabilizing mass 108 includes a dense metal (e.g. having a density greater than 6g/cm ³ ), such as a tungsten alloy (e.g. 80% or more tungsten, and remainder is other metal(s) such as nickel, copper, or iron). For example, magnetic stabilizing mass 108 may be composed essentially of a dense metal body 180 carrying magnet(s) 160.

[0082] Still referring to FIG. 2, apparatus 100 may optionally include a magnetic field shield 184. Magnetic field shield 184 may help reduce the spread of magnetic fields emitted by magnetic housing 104 and magnetic stabilizing mass 108 outside of apparatus 100. This may reduce the risk that apparatus 100 may interfere with or damage electronic equipment (e.g. hard disk drives), cards with magnetic strips, pacemakers, and other articles/devices. As shown, magnetic field shield 184 may be connected to magnetic housing 104, and sized and positioned to overlay magnets 156 and 160. For example, magnetic field shield 184 may have a‘C-shape’ that extends over front and rear housing ends 144i and 1442, as well as upper end 1443 of magnetic housing 104.

[0083] In the illustrated embodiment, magnetic field shield 184 has a longitudinal length 188 that is equal to or greater than a length 192 of magnetic housing 104. As shown, magnetic field shield 184 has a lateral width 196 that is less than width 204 of magnetic housing 104. In other embodiments, shield width 196 may be equal to or greater than magnetic housing width 204.

[0084] Magnetic field shield 184 has a material, thickness, and surface area suitable to suppress magnetic fields from passing through magnetic field shield 184. For example, the magnetic field strength (e.g. measured in Guass units) measured at an outer side 216 of magnetic field shield 184 may be 0% to 5% of the magnetic field strength measured at an opposed inner side 220 of magnetic field shield 184. In some embodiments, magnetic field shield 184 is composed primarily of a nickel-iron, low- expansion allow containing 36% nickel (also known as Invar 36, FeNi36, or 64FeNi). [0085] In the illustrated example, magnetic field shield 184 is removably connected to magnetic housing 104 (i.e. magnetic field shield 184 can be selectively attached, removed, and reattached). This allows magnetic field shield 184 to be removed when not required, or to access magnetic stabilizing mass 108, bearing assembly 128, or magnets 156 or 160.

[0086] In other embodiments, apparatus 100 does not include a magnetic field shield.

[0087] Referring to FIG. 3, magnetic housing 104 may have an “open-air” housing interior 1 12 (i.e. housing interior 1 12 is open to the exterior environment). That is, magnetic housing 104 may not seal housing interior 1 12 (i.e. a gas or liquid tight seal is not provided). In the illustrated example, magnetic housing 104 includes an open upper end 1443, and a large aperture 212 in magnetic housing base 136. In one aspect, this avoids the cost and complexity of forming and maintaining a sealed housing interior 1 12. In another aspect, this allows for a minimalist magnetic housing 104 with reduced weight and cost. Still, for certain applications (e.g. dirty industrial applications, underwater applications), magnetic housing 104 may provide a magnetic housing interior 1 12 that is gas and/or liquid tight, such as to prevent an ingress of dirt or liquid that could interfere with the movement of magnetic stabilizing mass 108.

[0088] While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole.

Items

Item 1 : An apparatus for suppressing oscillations of an oscillating body, the apparatus comprising: a magnetic housing securable to the oscillating body, the magnetic housing defining a housing interior;

a magnetic stabilizing mass slideably coupled to the magnetic housing in the housing interior by a bearing assembly, the magnetic stabilizing mass being slideable between a first position and a second position, the magnetic stabilizing mass having an equilibrium position between the first position and the second position;

the magnetic housing producing magnetic fields that magnetically repel the magnetic stabilizing mass away from the first position at least when the magnetic stabilizing mass is offset from the equilibrium position toward the first position, and that magnetically repel the magnetic stabilizing mass away from the second position at least when the magnetic stabilizing mass is offset from the equilibrium position toward the second position.

Item 2: The apparatus of any preceding item, wherein the magnetic housing comprises one or more housing magnets, which collectively produce the magnetic fields.

Item 3: The apparatus of any preceding item, wherein the magnetic stabilizing mass comprises one or more stabilizing mass magnets, which collectively produce magnetic fields extending within the housing interior.

Item 4: The apparatus of any preceding item, further comprising an arm strap coupled to the housing.

Item 5: The apparatus of any preceding item, further comprising:

a magnetic field shield coupled to the magnetic housing, the magnetic field shield overlaying at least the one or more housing magnets and the one or more stabilizing mass magnets.

Item 6: The apparatus of any preceding item, wherein the magnetic field shield is removably coupled to the magnetic housing.

Item 7: The apparatus of any preceding item, wherein the magnetic stabilizing mass comprises a tungsten alloy.

Item 8: The apparatus of any preceding item, wherein each of the one or more housing magnets and the one or more stabilizing mass magnets is a permanent magnet. Item 9: The apparatus of any preceding item, wherein the housing interior is open to an external environment.

Item 10: The apparatus of any preceding item, wherein:

the one or more housing magnets and the one or more stabilizing mass magnets are collectively positioned to generate a first magnetic repulsion force that increases relative to an offset of the magnetic stabilizing mass from the equilibrium position toward the first position, and a second magnetic repulsion force that increases relative to an offset of the magnetic stabilizing mass from the equilibrium position toward the second position.

Item 1 1 : The apparatus of any preceding item, wherein

the magnetic housing comprises a housing front end and a housing rear end, the housing front end opposite the housing rear end,

the magnetic stabilizing mass comprises a stabilizing mass front end and a stabilizing mass rear end, the stabilizing mass front end opposite the stabilizing mass rear end,

in the first position, the stabilizing mass rear end is proximate to the housing rear end, and

in the second position, the stabilizing mass front end is proximate to the housing front end.

Item 12: The apparatus of any preceding item, wherein the one or more housing magnets comprise a front housing magnet at the housing front end and a rear housing magnet at the housing rear end.

Item 13: The apparatus of any preceding item, wherein the one or more stabilizing mass magnets comprise a front stabilizing mass magnet at the stabilizing mass front end and a rear stabilizing mass magnet at the stabilizing mass rear end.

Item 14: The apparatus of any preceding item, wherein the rear housing magnet is oriented to repel the rear stabilizing mass magnet, and the front housing magnet is oriented to repel the front stabilizing mass magnet. Item 15: The apparatus of any preceding item, wherein the bearing assembly constrains the magnetic stabilizing mass to sliding between the first position and the second position along a linear path.

Item 16: The apparatus of any preceding item, wherein the linear path is straight.

Item 17: The apparatus of any preceding item, wherein the linear path is curved.

Item 18: The apparatus of any preceding item, wherein the magnetic stabilizing mass is suspended in the housing interior by the bearing assembly.

Item 19: The apparatus of any preceding item, wherein the bearing assembly comprises a guide rail supporting the magnetic stabilizing mass and constraining the magnetic stabilizing mass to sliding between the first position and the second position along a linear path.

Item 20: The apparatus of any preceding item, wherein the guide rail extends through the magnetic stabilizing mass.

Item 21 : A method of suppressing oscillations of an oscillating body, the method comprising:

securing a magnetic housing to the oscillating body, the magnetic housing containing a magnetic stabilizing mass slideable between a first position and a second position through an equilibrium position; and

in response to an oscillation of the oscillating body, the secured magnetic housing magnetically repelling the magnetic stabilizing mass away from the first position and second positions toward the equilibrium position, suppressing the oscillation.

Item 22: The method of any preceding item further comprising a user grasping the oscillating body and imparting the oscillation to the oscillating body.

Item 23: The method of any preceding item, wherein the secured magnetic housing magnetically repelling the magnetic stabilizing mass comprises: the magnetic stabilizing mass sliding in the magnetic housing.

Item 24: The method of any preceding item, wherein the magnetic stabilizing mass sliding in the magnetic housing comprises: the magnetic stabilizing mass sliding along a linear path. Item 25: The method of any preceding item, wherein the magnetic stabilizing mass sliding in the magnetic housing comprises: the magnetic stabilizing mass sliding along a curved linear path.

Item 26: The method of any preceding item, wherein the magnetic stabilizing mass is suspended in the magnetic housing by a bearing assembly.

Item 27: The method of any preceding item, wherein the secured magnetic housing magnetically repelling the magnetic stabilizing mass comprises:

generating magnetic repulsion forces that increase relative to an offset of the magnetic stabilizing mass from the equilibrium position toward the first and second positions.

Item 28: The method of any preceding item, wherein the secured magnetic housing magnetically repelling the magnetic stabilizing mass comprises repeatedly:

the magnetic stabilizing mass sliding from the equilibrium position toward the first position;

a first housing magnet magnetically repelling the magnetic stabilizing mass away from the first position toward the equilibrium position;

the magnetic stabilizing mass sliding from the equilibrium position toward the second position; and

a second housing magnet magnetically repelling the magnetic stabilizing mass away from the second position toward the equilibrium position.

Item 29: The method of any preceding item, wherein:

the first housing magnet magnetically repelling the magnetic stabilizing mass comprises the first housing magnet and a first stabilizing mass magnet generating a first repulsive force, and

the second housing magnet magnetically repelling the magnetic stabilizing mass comprises the second housing magnet and a second stabilizing mass magnet generating a second repulsive force.

Item 30: The method of any preceding item, wherein the oscillating body is a user’s arm. Item 31 : The method of any preceding item, wherein the oscillating body is a 3D printer print head.

Item 32: The method of any preceding item, wherein the oscillating body is a household appliance.

Item 33: The method of any preceding item, wherein the oscillating body is a robotic arm.

Item 34: The method of any preceding item, wherein the oscillating body is a camera.

Item 35: The method of any preceding item, further comprising a user grasping the camera and imparting the oscillation to the camera.

Item 36: The method of any preceding item, wherein said the oscillating body is a firearm.

Item 37: The method of any preceding item, further comprising a user grasping the firearm and imparting the oscillation to the firearm.