Patent Application
20200037746
In an aspect the present disclosure provides an end effector generally including a base portion coupleable to a motor; a spring coupled to the base portion; and a mass coupled to the spring configured to move relative to the base portion, wherein the spring is configured to fatigue and fail after a predetermined number of cycles, and wherein the end effector is configured to provide indicia of fatigue failure of the spring.
In another aspect, the present disclosure provides a system generally including an appliance including a motor; and an end effector coupleable to the motor and configured to receive motion of the motor, the end effector generally including a spring coupled to a base portion; and a mass coupled to the spring configured to move relative to the base portion, wherein the spring is configured to fatigue and fail after a predetermined number of cycles, and wherein the end effector is configured to provide indicia of fatigue failure of the spring.
This foregoing summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
Aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.
The detailed description set forth below in connection with the appended drawings, where like numerals reference like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.
The following discussion provides examples of end effectors and systems including end effectors configured to provide indicia of a wear state of the end effector. In the examples of the end effectors and systems set forth in more detail below, several are provided that are configured to provide audible and/or haptic indicia when an end effector is worn or otherwise no longer suitable for use.
Through use an end effector, such as a brush, exfoliator, applicator, and the like, may become worn, dirty, or otherwise ready for replacement. Many conventional end effectors do not provide indicia of a wear state. In this regard, such conventional end effectors do not indicate to a user when the end effector is ready for replacement. Accordingly, a user may use an end effector when the end effector is dirty and/or is structurally damaged and no longer able to perform in a preferred manner.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that many embodiments of the present disclosure may be practiced without some or all of the specific details. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein.
Turning now to
As discussed further herein, the end effector 100 is configured to provide indicia of fatigue failure of the spring 106A. In an embodiment, the end effector 100 is configured to provide audible or haptic indicia of such fatigue failure. Accordingly, in an embodiment, the spring 106A and the mass 110A are disposed in an interior portion 114 of a chamber 112 of the end effector 100. When the spring 106A fails due to fatigue the mass 110A, which is no longer couple to the spring 106A, impinges upon sides of the chamber 112 when, for example, the base portion 102 moves. In that regard, the end effector 100 is configured to provide audible or haptic indicia of fatigue failure detectable by a user when mass 110A impinges upon, for example, the interior portion 114 of chamber 112. Such audible or haptic indicia of fatigue failure may be further indicative of a wear state of the end effector 100.
In an embodiment, the haptic or audible indicia do not inhibit other functions of the end effector. In this regard, the end effector may still be coupleable to a motor and used to, for example, wash the face of a user after fatigue failure of the spring 106A.
In an embodiment, the spring 106A includes a stress riser configured to raise stress levels at a particular portion(s) of the spring 106A during oscillation or other cyclic movement. Such stress risers can include, for example, a notch, a plurality of holes in the spring 106A, and a portion having an increased width. Such stress risers may be configured to increase bending within or adjacent to the stress riser. In the illustrated embodiment, spring 106A includes a portion 116A having a cross section of a first width and a notch section 118A having a second width less than the first width. As the mass 110A and spring 106A oscillate or otherwise move to displace spring 106A, the spring 106A bends to a greater degree within or adjacent to the notch section 118A than at other portions of the spring 106A. Such increased bending raises stress levels and, for example, decrease the number of cycles required for fatigue failure of the spring 106A. As illustrated in
Further by reducing the width of the spring 106A and concentrating stress in the notch section 118A, tighter tolerances for manufacturing the spring 106A can be applied to the notch section 118A and, for example, not in other portions of the spring 106A. In this regard, the spring 106A is configured to fail within a smaller range of oscillations and the end effector 100 is configured to provide indicia of a wear state after a narrower range of use (e.g. a narrower range of oscillations). Further, the by including such a stress riser in the end effector 100, the end effector 100 may be designed to provide a more targeted range of use before providing indicia of a wear state. Additionally, relatively tight manufacturing processes to make the spring 106A can be applied to only a relatively small portion of the spring 106A, i.e. the notch section 118A, thus reducing manufacturing costs.
Spring 106A can include any type of spring coupleable to mass 110A and configured to fail due to fatigue. In an embodiment, the spring 106A is selected from the group consisting a tension/extension spring, a compression spring, a torsion spring, and the like. In an embodiment, the spring is a flexural spring. In an embodiment, spring 106A is a metal beam coupled to mass 110A at a first end and post 108 at a second end.
In an embodiment, the spring 106A has a steep fatigue curve compared to the uncertainty of the fatigue curve. A S-N curve is a plot of the magnitude of an alternating stress versus the number of cycles to failure for a given material. With a steep S-N curve having low uncertainty, the statistical range in which the spring 106A will fail is relatively small. As above, with a statistically smaller range of oscillations required for failure, a spring 106A in an end effector 100 can be designed to provide indicia of fatigue failure and of a wear state of the end effector 100 in a narrower range of oscillations, as well. In this regard, end effector 100 may be designed to provide such indicia of a wear state of the end effector 100 relatively close to a predetermined number of oscillations.
In an embodiment, the spring 106A includes a spring material selected from the group consisting of aluminum, an aluminum alloy, steel, titanium, a titanium alloy, a polymeric material, zinc alloys, magnesium and combinations thereof. In an embodiment, the spring 106A includes an aluminum alloy. Many such aluminum alloys have steep fatigue failure curves and, as discussed further herein, are suitable to provide haptic or audible indicia of fatigue failure within a relatively narrow range of use. In an embodiment, the aluminum alloy is a 2000-series aluminum alloy, which typically have steep fatigue failure curves.
In an embodiment, spring 106A is configured to fail due to fatigue in a range of about 100,000 oscillations to about 10,000,000 oscillations. In an embodiment, spring 106A is configured to fail due to fatigue after about 1,000,000 oscillations.
In an embodiment, the spring 106A is a first spring 106A and the mass 110A is a first mass 100, the end effector 100 further includes a second spring 106B coupled to the base portion 102; and a second mass 110B coupled to the second spring 106B configured to move relative to the base portion 102. It is less likely that all of the two or more springs will remain intact after a cycling beyond the predetermined number of cycles than a single spring. In this regard, the end effector 100 is statistically more likely to provide indicia of a wear state closer to a predetermined number of cycles by including two or more springs each coupled to a mass.
As shown in
In the illustrated embodiment spring 106B has a portion 116B having a cross section of a first width; and a notch section 118B having a cross section of a second width less than the first width analogous to the notch section 118A disposed on spring 106A. As above, such a notch section 118B concentrates stress and increases consistency of fatigue failure.
In the illustrated embodiment, end effector 100 is a brush including a plurality of bristles 104. However, it will be understood that end effector 100 may include other forms of end effectors, such as a massager, an applicator, an exfoliator, and the like.
In an embodiment, the end effectors of the present disclosure include a visible indicator of fatigue failure. In this regard, attention is directed to
End effector 200 further includes flags 220A and 220 B disposed on masses 210A and 210B, respectively, and apertures 224A and 224B. As shown in
End effector 200 is shown to further include one or more stops 222A-222D configured to limit oscillation of springs 206A and 206B. As discussed further herein with respect to
In another aspect, the present disclosure provides a system 301 including an appliance 303 including a motor 305 and an end effector 300 coupled to the motor 305 and configured to receive motion from the motor 305. In an embodiment, end effector 300 is an example of end effector 100 or end effector 200.
In the illustrated embodiment, end effector 300 includes springs 306A and 306B coupled to a base portion 302 by post 308; masses 310A and 310B coupled to springs 306 and 306B configured to move relative to the base portion 302; and a plurality of bristles 304. As discussed further herein with respect to
In an embodiment, the motor 305 has a resonant motor oscillation frequency such that when operating the motor 305 oscillates end effector 300 at the resonant motor oscillation frequency when end effector 300 is coupled to appliance 303. In a further embodiment, springs 306A and 306B have a resonant spring oscillation frequency at which springs 306A and 306B resonantly oscillate.
In certain embodiments, the resonant spring oscillation frequency is equal or substantially equal to resonant motor oscillation frequency. In this instance, substantially equal refers to a resonant spring oscillation frequency having a frequency that is within 10% or less, 5% or less, or 1% or less the resonant motor oscillation frequency. Accordingly, when the motor 305 is oscillating at the resonant motor oscillation frequency the springs 306A and 306B are likewise oscillating at the same or substantially the same frequency. In this regard, oscillation amplitudes of springs 306A and 306B are increased relative to oscillation amplitudes if the resonant motor oscillation frequency and the resonant spring oscillation frequency had greater differences. Such large spring oscillation amplitudes increase stress and strain in springs 306A and 306B, thus increasing the likelihood of and decreasing the number of oscillations required to fatigue failure of springs 306A and 306B.
In an embodiment, end effector 300 includes one or more stops (not shown, see
In an embodiment, springs 306A and 306B have a resonant spring oscillation frequency that is less than or greater than the resonant motor oscillation frequency. In this regard, as base portion 302 receives oscillating motion from the motor 305 and springs 306A and 306B move relative to base portion 302, vibration rather than oscillation is induced in springs 306A and 306B. Such vibrations induce stress and strain to springs 306A and 306B, which after a predetermined number of cycles cause fatigue failure of springs 306A and 306B.
In an embodiment, end effector 300 includes a flag (not shown, see for example
In an embodiment, springs 306A and 306B include a portion having a cross section of a first width; and a notch section having a cross section of a second width less than the first width. As discussed further herein with respect to
In an embodiment, masses 310A and 310B are part of an electrical circuit including an indicator (not shown), such as a light or other visible, electrically powered indicator, configured to provide the indicia upon fatigue failure of the springs 306A and 306B. For example, in an embodiment, masses 310A and 310B and springs 306A and 306B are electrically conductive. When one or more of springs 306A and 306B fails due to fatigue, a portion of the electrical circuit is broken or completed and, thus provides the indicia of fatigue failure.
It should be noted that for purposes of this disclosure, terminology such as “upper,” “lower,” “vertical,” “horizontal,” “inwardly,” “outwardly,” “inner,” “outer,” “front,” “rear,” etc., should be construed as descriptive and not limiting the scope of the claimed subject matter. Further, the use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. The term “about” means plus or minus 5% of the stated value.
The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure which are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure, as claimed.
While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the claimed subject matter.
