Patent Description:
Percussive massage, which is also referred to as tapotement, is the rapid, percussive tapping, slapping and cupping of an area of the human body. Percussive massage is used to more aggressively work and strengthen deep-tissue muscles. Percussive massage increases local blood circulation and can even help tone muscle areas. Percussive massage may be applied by a skilled massage therapist using rapid hand movements; however, the manual force applied to the body varies, and the massage therapist may tire before completing a sufficient treatment regime.

Percussive massage may also be applied by electromechanical percussive massage devices (percussive applicators), which are commercially available. Such percussive applicators may include, for example, an electric motor coupled to drive a reciprocating piston within a cylinder. A variety of percussive heads may be attached to the piston to provide different percussive effects on selected areas of the body. Many of the known percussive applicators are expensive, large, relatively heavy, and tethered to an electrical power source. For example, some percussive applicators may require users to grip the applicators with both hands in order to control the applicators. Some percussive applicators are relatively noisy because of the conventional mechanisms used to convert the rotational energy of an electric motor to the reciprocating motion of the piston.

<CIT> a battery-powered percussive massage device comprising:.

A need exists for an electromechanical percussive massage device that is less costly, is small, has a relatively light weight, and is portable (e.g., untethered to an electrical power source). A further need exists for an electromechanical percussive massage device that is quitter (less noisy) than conventional devices.

The invention provides a battery-powered percussive massage device as specified in claim <NUM>.

One aspect of the embodiments disclosed herein is a percussive massage device that includes an enclosure having a cylindrical bore that extends along a longitudinal axis. A motor has a rotatable shaft that rotates about a central axis perpendicular to the longitudinal axis. A crank coupled to the shaft includes a pivot, which is offset from the central axis of the shaft. A transfer bracket has a first end portion coupled to the pivot of the crank. A flexible transfer linkage has a first end coupled to a second end portion of the transfer bracket. A piston has a first end coupled to a second end of the transfer linkage. The piston is constrained to move within a cylinder along the longitudinal axis of the cylindrical bore. An applicator head has a first end coupled to a second end of the piston and has a second end exposed outside the cylindrical bore for application to a person receiving treatment.

Another aspect of the embodiments disclosed herein is a percussive massage device. The device comprises an enclosure having a cylindrical bore. The cylindrical bore extends along a longitudinal axis. A motor is positioned within the enclosure. The motor has a rotatable shaft having a central axis. The central axis of the shaft is perpendicular to the longitudinal axis of the cylindrical bore. A crank is coupled to the shaft. The crank includes a pivot, which is offset from the central axis of the shaft. A transfer bracket has a first end portion coupled to the pivot of the crank. A flexible transfer linkage has a first end coupled to a second end portion of the transfer bracket. A piston has a first end coupled to a second end of the transfer linkage. The piston is positioned within the cylindrical bore of the enclosure and is constrained to move only along the longitudinal axis of the cylindrical bore. An applicator head has a first end coupled to a second end of the piston. A second end of the applicator head is exposed outside the cylindrical bore. In certain embodiments in accordance with this aspect, the pivot of the crank is rotatable <NUM> degrees about the central axis of the shaft of the motor. The pivot is substantially aligned with the longitudinal axis of the cylindrical bore at a first rotational position and at a second rotational position. The first and second rotational positions are spaced apart angularly by <NUM> degrees. The pivot is offset from the longitudinal axis in a first offset direction when the pivot is at a rotational position between the first rotational position and the second rotational position in a first angular direction with respect to the first rotational position. The pivot is offset from the longitudinal axis in a second offset direction when the pivot is at a rotational position between the first rotational position and the second rotational position in a second angular direction opposite the first angular direction. The flexible transfer linkage is substantially straight and is aligned with the longitudinal axis of the cylindrical bore when the pivot of the crank is aligned with the longitudinal axis of the central bore at the first rotational position or at the second rotational position. The flexible transfer linkage bends in a first direction with respect to the longitudinal axis of the cylindrical bore when the pivot of the crank is offset from the longitudinal axis in the first offset direction. The flexible transfer linkage bends in a second direction with respect to the longitudinal axis of the cylindrical bore when the pivot of the crank is offset from the longitudinal axis in the second offset direction. In certain embodiments, the applicator head is removably coupled to the piston. In certain embodiments, the flexible transfer linkage comprises resilient rubber. In certain embodiments, the resilient rubber has a Shore durometer hardness of approximately <NUM>.

Another aspect of the embodiments disclosed herein is a method of operating a percussive massage device. The method comprises rotating a shaft of an electric motor to rotate a pivot of a crank about a centerline of the shaft; coupling the pivot of the crank to a first end of a flexible interconnection linkage of a reciprocation assembly; coupling a second end of the flexible interconnection linkage to a piston constrained to move along a longitudinal centerline; and coupling the piston to an applicator head wherein rotational movement of the pivot of the crank causes reciprocation longitudinal movement of the piston and the applicator head. In certain embodiments of the method, the applicator head is removably coupled to the piston. In certain embodiments of the method, the flexible transfer linkage comprises resilient rubber. In certain embodiments of the method, the resilient rubber has a Shore durometer hardness of approximately <NUM>.

Another aspect of the embodiments disclosed herein is a method of assembling a percussive massage device. The method comprises attaching an eccentric crank to the shaft of a motor, the eccentric crank having a pivot; coupling a first portion of a bearing holder to the pivot of the eccentric crank; attaching a first end of a flexible interconnection linkage to a second portion of the bearing holder; attaching a second end of the flexible interconnection linkage to a first end of a piston, the piston constrained to longitudinal movement within a cylinder; and removably attaching an applicator head to a second end of the piston. In certain embodiments of the method, the flexible transfer linkage comprises resilient rubber. In certain embodiments of the method, the resilient rubber has a Shore durometer hardness of approximately <NUM>.

The foregoing aspects and other aspects of the disclosure are described in detail below in connection with the accompanying drawings in which:.

As used throughout this specification, the words "upper," "lower," "longitudinal," "upward," "downward," "proximal," "distal," and other similar directional words are used with respect to the views being described. It should be understood that the percussive massage applicator described herein can be used in various orientations and is not limited to use in the orientations illustrated in the drawing figures.

A portable electromechanical percussive massage applicator ("percussive massage applicator") <NUM> is illustrated in <FIG>. As described below, the percussive massage applicator can be applied to different locations of body to apply percussion to the body to effect percussive treatment. The percussive massage applicator is operable with removably attachable applicator heads to vary the effect of the percussive strokes. The percussive massage applicator operates at a plurality of speeds (e.g., three speeds).

The portable electromechanical percussive massage applicator <NUM> includes a main body <NUM>. The main body includes an upper body portion <NUM> and a lower body portion <NUM>. The two body portions engage to form a generally cylindrical enclosure about a longitudinal axis <NUM> (<FIG>).

A generally cylindrical motor enclosure <NUM> extends upward from the upper body portion <NUM>. The motor enclosure is substantially perpendicular to the upper body portion. The motor enclosure is capped with a motor enclosure endcap <NUM>. The motor enclosure and the upper body portion house a motor assembly <NUM> (<FIG>). The upper body portion also supports a reciprocation assembly <NUM> (<FIG>), which is coupled to the motor assembly as described below.

A generally cylindrical battery assembly receiving enclosure <NUM> extends downward from the lower body portion <NUM> and is substantially perpendicular to the lower body portion. A battery assembly <NUM> extends from the battery assembly receiving enclosure.

A main body endcap <NUM> is positioned on a proximal end of the main body <NUM>. In addition to other functions described below, the main body endcap also serves as a clamping mechanism to hold the respective proximal ends of the upper body portion <NUM> and the lower body portion <NUM> together. As illustrated in <FIG>, the endcap includes a plurality of protrusions <NUM> on an inner perimeter surface <NUM>. The protrusions are positioned to engage a corresponding plurality of L-shaped notches <NUM> on the outer perimeters of the proximal ends of the upper body portion and the lower body portion. In the illustrated embodiment, two notches are formed on the upper body portion and two notches are formed on the lower body portion. The protrusions on the endcap are inserted into the proximal ends of the notches until seated against the distal ends of the notches. The endcap is then twisted by a few degrees (e.g., approximately <NUM> degrees) to lock the endcap to the two body portions. A screw <NUM> is then inserted through a bore <NUM> in the endcap to engage the lower body portion to prevent the endcap from rotating to unlock during normal use.

As shown in <FIG>, the main body endcap <NUM> houses a motor controller (main) printed circuit board (PCB) <NUM>. As shown in <FIG>, the proximal side of the main PCB supports a central pushbutton switch <NUM>. The operation of the switch is described below in connection with the electronic circuitry. As shown in <FIG>, the switch is surrounded on the endcap by a plurality of bores <NUM>, which extend perpendicularly from the outer (proximal) surface of the endcap to form a plurality of concentric rows of bores. Selected ones of the bores are through bores, which allow airflow through the endcap. Three of the bores above the switch have respective speed indication light-emitting diodes (LEDs) 166A, 166B, 166C positioned therein. The three LEDs extend from the proximal side of the PCB as shown in <FIG>. The three LEDs provide an indication of the operational state of the percussive massage applicator <NUM> as described in more detail below. Five of the bores located below the switch have respective battery charge state LEDs 168A, 168B, 168C, 168D, 168E positioned therein. The five LEDs also extend from the proximal side of the PCB as shown in <FIG>. The five LEDs provide an indication of the charge state of the battery when the battery assembly <NUM> is attached and is providing power to the percussive massage applicator. As shown in <FIG>, the distal side of the PCB supports a first plug <NUM>, which includes three contact pins that are connectable to the battery assembly <NUM> as described below. The distal side of the PCB also supports a second plug <NUM>, which includes five contact pins that are connectable to the motor assembly <NUM> as described below.

As shown in <FIG> and <FIG>, a distal portion of the lower body portion <NUM> includes a plurality of through bores <NUM> (e.g., four through bores) that are aligned with a corresponding plurality of through bores <NUM> in the upper body portion <NUM>. When lower body portion is attached to the upper body portion, a plurality of interconnection screws <NUM> pass through the through bores in the lower body portion and engage the through bores of the upper body portion to further secure the two body portions together. A plurality of plugs <NUM> are inserted into outer portions of the through bores of the lower body portion to hide the ends of the interconnection screws.

As shown in <FIG> and <FIG>, the lower body portion <NUM> includes a battery assembly receiving tray <NUM>, which is secured to the inside of the lower body portion in alignment with the battery assembly receiving enclosure <NUM>. The receiving tray is secured to the lower body portion with a plurality of screws <NUM> (e.g., four screws). The receiving tray includes a plurality of leaf spring contacts 204A, 204B, 204C (e.g., three contacts), which are positioned in a triangular pattern. The three contacts are positioned to engage a corresponding plurality of contacts 206A, 206B, 206C, which are positioned around the top edge of the battery assembly <NUM> when the battery assembly is positioned in the battery assembly receiving enclosure.

The battery assembly <NUM> includes a first battery cover half <NUM> and a second battery cover half <NUM>, which enclose a battery unit <NUM>. In the illustrated embodiment, the battery unit comprises six <NUM>-volt lithium-ion battery cells connected in series to produce an overall battery voltage of approximately <NUM> volts when fully charged. The battery cells are commercially available from many suppliers, such as, for example, Samsung SDI Co. , of South Korea. The first battery cover half and the second battery cover half snap together. The two halves are further held together by an outer cylindrical cover <NUM>, which also serves as a gripping surface when the percussive massage applicator <NUM> is being used. In the illustrated embodiment, the outer cover extends only over the portion of the battery assembly that does not enter the battery receiving enclosure <NUM>. In the illustrated embodiment, the outer cover comprises neoprene or another suitable material that combines a cushioning layer with an effective gripping surface.

The upper end of the battery assembly <NUM> includes a first mechanical engagement tab <NUM> and a second mechanical engagement tab <NUM> (<FIG>). As shown in <FIG>, for example, when the battery assembly is fully inserted into the battery assembly receiving enclosure <NUM>, the first engagement tab engages a first ledge <NUM> and the second engagement tab engages a second ledge <NUM> within the battery assembly receiving enclosure to secure the battery assembly within the battery assembly receiving enclosure.

The lower body portion <NUM> includes a mechanical button <NUM> in alignment with the first engagement tab <NUM>. When sufficient pressure is applied to the button, the first engagement tab is pushed away from the first ledge <NUM> to allow the first engagement tab to move downward with respect to the first ledge and thereby disengage from the ledge. In the illustrated embodiment, the mechanical button is biased by a compression spring <NUM>. The lower body portion further includes an opening <NUM> (<FIG>) opposite the mechanical button. The opening allows a user to insert a fingertip into the opening to apply pressure to disengage the second engagement tab <NUM> from the second ledge <NUM> and at the same time to apply downward pressure to move the second engagement tab downward away from the second ledge and thereby move the battery assembly <NUM> downward. Once disengaged in this manner, the battery assembly is easily removed from the battery assembly receiving enclosure <NUM>. In the illustrated embodiment, the opening is covered in part by a flap <NUM>. The flap may be biased by a compression spring <NUM>. In alternative embodiments (not shown), a second mechanical button may be included in place of the opening.

The second battery cover half <NUM> includes an integral printed circuit board support structure <NUM>, which supports a battery controller printed circuit board (PCB) <NUM>. The battery controller PCB is shown in more detail in <FIG>. In addition to other components, the battery controller PCB includes a charging power adapter input jack <NUM> and an on/off switch <NUM>. In the illustrated embodiment, the on/off switch is a slide switch. The battery controller PCB further supports a plurality of light-emitting diodes (LEDs) <NUM> (e.g., six LEDs), which are mounted around the periphery of the battery controller PCB. In the illustrated embodiment, each LED is a dual-color LED (e.g., red and green), which may be illuminated to display either color. The battery controller PCB is mounted to a battery assembly endcap <NUM>. A translucent plastic ring <NUM> is secured between the battery controller PCB and the battery assembly endcap such that the ring generally aligned with the LEDs. Accordingly, light emitted by the LEDs is emitted through the ring. As discussed below, the color of the LEDs may be used to indicate the charged state of the battery assembly <NUM>. A switch actuator extender <NUM> is positioned on the actuator of the slide switch and extends through the endcap to enable the slide switch to be manipulated from the outside of the endcap.

As illustrated in <FIG>, the motor enclosure <NUM> houses the electric motor assembly <NUM>, which is shown in more detail in <FIG>. The electric motor assembly includes a brushless DC electric motor <NUM> having a central shaft <NUM> that rotates in response to applied electrical energy. In the illustrated embodiment, the electric motor is a <NUM>-volt brushless DC motor. The electric motor may be a commercially available motor. The diameter and height of the motor enclosure and the mounting structures (described below) are adaptable to receive and secure the electric motor within the motor enclosure.

The electric motor <NUM> is secured to a motor mounting bracket <NUM> via a plurality of motor mounting screws <NUM>. The motor mounting bracket includes a plurality of mounting tabs <NUM> (e.g., four tabs). Each mounting tab includes a central bore <NUM>, which receives a respective rubber grommet <NUM>, wherein first and second enlarged portions of the grommet are positioned on opposite surfaces of the tab. A respective bracket mounting screw <NUM> having an integral washer is passed through a respective central hole <NUM> in each grommet to engage a respective mounting bore <NUM> in the upper body portion <NUM>. Two of the four mounting bores are shown in <FIG>. The grommets serve as vibration dampers between the motor mounting bracket and the upper body portion.

The central shaft <NUM> of the electric motor <NUM> extends through a central opening <NUM> in the motor mounting bracket <NUM>. The central shaft engages a central bore <NUM> of an eccentric crank <NUM>. The central bore is press-fit onto the central shaft of the electric motor or is secured to the shaft by another suitable technique (e.g., using a setscrew).

The eccentric crank <NUM> has a circular disk shape. The crank has an inner surface <NUM> oriented toward the electric motor and an outer surface <NUM> oriented away from the electric motor. A cylindrical crank pivot <NUM> is secured to or formed on the outer surface and is offset from the central bore of the crank in a first direction by a selected distance (e.g., <NUM> millimeters in the illustrated embodiment). An arcuate cage <NUM> extends from the inner surface of the crank and is generally positioned diametrically opposite the crank pivot with reference to the central bore <NUM> of the crank. A semi-annular weight ring <NUM> is inserted into the arcuate cage and is secured therein by screws, crimping or by using another suitable technique. The masses of the arcuate cage and the semi-annular weight ring operate to at least partially counterbalance the mass of the crank and the forces applied to the crank, as described below.

As shown in <FIG> and <FIG>, the distal end of the upper body portion <NUM> supports a generally cylindrical outer sleeve <NUM> having a central bore <NUM>. In the illustrated embodiment, a distal portion <NUM> proximate to a distal end <NUM> of the outer sleeve is tapered inward toward the central bore. The outer sleeve has an annular base <NUM> that is secured to the distal end of the upper body portion by a plurality of screws <NUM> (e.g., three screws).

The outer sleeve <NUM> surrounds a generally cylindrical mounting sleeve <NUM> that is secured within the outer sleeve when the outer sleeve is secured to the upper body portion <NUM>. The mounting sleeve surrounds a cylinder body <NUM> that is clamped by the mounting sleeve and is secured in a concentric position with respect to the longitudinal axis <NUM> of the percussive massage applicator <NUM>. In addition to securing the cylinder body, the mounting sleeve serves as a vibration damper to reduce vibrations propagating from the cylinder body to the main body <NUM> of the percussive massage applicator. In the illustrated embodiment, the cylinder body has a length of approximately <NUM> millimeters and has an inner bore <NUM>, which has an inner diameter of approximately <NUM> millimeters. In particular, the inner diameter of the cylinder body is at least <NUM> millimeters plus a selected clearance fit (e.g., approximately <NUM> millimeters plus approximately <NUM> millimeters).

As shown in <FIG>, the percussive massage applicator <NUM> includes the reciprocating assembly <NUM>, which comprises a crank engagement bearing holder <NUM>, which may also be referred to as a; a flexible interconnection linkage <NUM>, which may also be referred to as a flexible transfer linkage; a piston <NUM>; and an applicator head <NUM>. The reciprocating assembly is shown in more detail in <FIG> and <FIG>.

The crank engagement bearing holder <NUM> comprises a bearing housing <NUM> having an upper end wall <NUM> that defines the end of a cylindrical cavity <NUM>. An annular bearing <NUM> fits within the cylindrical cavity. A removably attachable lower end wall <NUM> is secured to the bearing housing by a plurality of screws <NUM> (e.g., two screws) to constrain the annual bearing within the cylindrical cavity. The annular bearing includes a central bore <NUM> that is sized to engage the cylindrical crank pivot <NUM> of the eccentric crank <NUM>.

The crank engagement bearing holder <NUM> further includes an interconnect portion <NUM> that extends radially from the bearing housing <NUM>. The interconnect portion includes a disk-shaped interface portion <NUM> having a threaded longitudinal central bore <NUM>. The central bore is aligned with a radial line <NUM> directed toward the center of bearing housing. In the illustrated embodiment, the central bore is threaded with an 8x1. <NUM> metric external thread. The interface portion has an outer surface <NUM>, which is orthogonal to the radial line. The center of the outer surface of the interface portion is approximately <NUM> millimeters from the center of the bearing housing. The interface portion has an overall diameter of approximately <NUM> millimeters and has a thickness of approximately <NUM> millimeters. A lower portion <NUM> of the interface portion may be flattened to provide clearance with other components. Selected portions of the interface portion may be removed to form ribs <NUM> to reduce the overall mass of the interface portion.

A threaded radial bore <NUM> is formed in the interface portion <NUM>. The threaded radial bore extends from the outer perimeter of the interface portion to the threaded longitudinal central bore <NUM>. The threaded radial bore has an internal thread selected to engage a bearing holder setscrew <NUM> that is inserted into the third threaded bore. The bearing holder setscrew is rotated to a selected depth as described below.

As used herein, "flexible" in connection with the flexible interconnection linkage <NUM> means that the linkage is capable of bending without breaking. The linkage comprises a resilient rubber material. The linkage may have a Shore A durometer hardness of around <NUM>; however, softer or harder materials in a medium soft Shore hardness range of 35A to 55A may be used. The linkage is molded or otherwise formed to have a shape similar to an hour glass. That is, the shape of the linkage is relatively larger at each end and relatively narrower in the middle. In the illustrated embodiment, the linkage has a first disk-shaped end portion <NUM> and a second disk-shaped end portion <NUM>. In the illustrated embodiment, the two end portions have similar thicknesses of approximately <NUM> millimeters and have similar outer diameters of approximately <NUM> millimeters. The material between the two end portions tapers to middle portion <NUM>, which has a diameter of approximately <NUM> millimeters. In general, the middle portion has a diameter that is between <NUM> percent and <NUM> percent of the diameter of the end portions; however, the middle portion may be relatively smaller or relatively larger to accommodate materials having a greater hardness or a lesser hardness. The linkage has an overall length between the outer surfaces of the two end portions of approximately <NUM> millimeters. As discussed in more detail below, the smaller diameter middle portion of the linkage allows the linkage to flex easily between the two end portions.

A first threaded interconnect rod <NUM> extends from the first end portion <NUM> of the flexible interconnection linkage <NUM>. A second threaded interconnect rod <NUM> extends from the second end portion <NUM> of the linkage. In the illustrated embodiment, the interconnect rods are metallic and are embedded into the respective end portions. For example, in one embodiment, the linkage is molded around the two interconnect rods. In other embodiment, the two interconnect rods are adhesively fixed within respective cavities formed in the respective end portions. In a still further embodiment, the two interconnect rods are formed as integral threaded rubber portions of the linkage.

The first interconnect rod <NUM> of the flexible interconnection linkage <NUM> has an external thread selected to engage with the internal thread of the threaded longitudinal central bore <NUM> of the crank engagement bearing holder <NUM> (e.g., an 8x1. <NUM> metric external thread). When the thread of the first interconnect rod is fully engaged with the thread of the longitudinal central bore, the bearing holder setscrew <NUM> is rotated to cause the inner end of the setscrew to engage the thread of the first interconnect rod within the longitudinal central bore to inhibit the first interconnect rod from rotating out of the longitudinal central bore.

In the illustrated embodiment, the second interconnect rod <NUM> of the flexible interconnection linkage <NUM> has an external thread similar to the thread of the first interconnect rod <NUM> (e.g., an 8x1. <NUM> metric external thread). In other embodiments, the threads of the two interconnect rods may be different.

In the illustrated embodiment, the piston <NUM> comprises stainless steel or another suitable material. The piston has an outer diameter that is selected to fit snugly within the inner bore <NUM> of the cylinder body <NUM> described above. For example, the outer diameter of the illustrated piston is no greater than approximately <NUM> millimeters. As discussed above, the inner diameter of the inner bore of the cylinder body is at least <NUM> millimeters plus a selected minimum clearance allowance (e.g., approximately <NUM> millimeter). Thus, with the outer diameter of the piston being no more than <NUM> millimeters, the piston has sufficient clearance with respect to the cylinder body that the piston is able to move smoothly within the cylinder body without interference. The maximum clearance is selected such that no significant play exists between the two parts.

In the illustrated embodiment, the piston <NUM> comprises a cylinder having an outer wall <NUM> that extends for a length of approximately <NUM> millimeters between a first end <NUM> and a second end <NUM>. A first bore <NUM> is formed in the piston for a selected distance from the first end toward the second end. For example, in the illustrated embodiment, the first bore has a depth (e.g., length toward the second end) of approximately <NUM> millimeters and has a base diameter of approximately <NUM> millimeters. A first portion <NUM> (<FIG>) of the first bore is threaded to form a 20x1. <NUM> metric internal thread to a depth of approximately <NUM> millimeters in the first bore.

A second bore <NUM> (<FIG>) is formed from the second end <NUM> of the piston <NUM> toward the first end. The second bore has a base diameter of approximately <NUM> millimeters and has a length sufficient to extend the second bore to the cavity formed by the first bore (e.g., a length of approximately <NUM> millimeters in the illustrated embodiment). The second bore is threaded for its entire length to form an internal thread in the second bore. The internal thread of the second bore engages the external thread of the second interconnect rod <NUM> of the interconnection linkage <NUM>. Accordingly, in the illustrated embodiment, the second bore has an 8x1. <NUM> metric internal thread.

A third bore <NUM> is formed in the piston <NUM> near the second end <NUM> of the piston. The third threaded bore extends radially inward from the outer wall <NUM> of the piston to the second threaded bore. In the illustrated embodiment, the third bore is threaded for the entire length of the bore. The third bore has an internal thread selected to engage a piston setscrew <NUM>, which is inserted into the third threaded bore. When the external thread of the second interconnect rod <NUM> of the flexible interconnection linkage <NUM> is fully engaged with the internal thread of the second bore <NUM> of the piston, the piston setscrew is rotated to cause the inner end of the setscrew to engage the external thread of the second interconnect rod within the second bore to inhibit the second interconnect rod from rotating out of engagement with the thread of the second bore.

The applicator head <NUM> of the reciprocating assembly <NUM> can be configured in a variety of shapes to enable a user to apply different types of percussive massage. The illustrated applicator head is "bullet-shaped" and is useful for apply percussive massage to selected relatively small surface areas of a body such as, for example, trigger points. In the illustrated embodiment, the applicator head comprises a medium hard to hard rubber material. The applicator head has an overall length from a first distal (application) end <NUM> to a second proximal (mounting) end <NUM> of approximately <NUM> millimeters. The applicator head has an outer diameter of approximately <NUM> millimeters for a length of approximately <NUM> millimeters along a main body portion <NUM>. An engagement portion <NUM> at the proximal (mounting) end of the applicator head has a length of approximately <NUM> millimeters and is threaded for a distance of approximately <NUM> millimeters to form an external 20x1. <NUM> metric thread that is configured to engage the internal thread of the first bore <NUM> of the piston <NUM>. The thread of the applicator head is removably engageable with the thread of the piston to allow the applicator head to be removed and replaced with a different applicator head as described below. The distal (applicator) end of the applicator has a length of approximately <NUM> millimeters and tapers from the diameter of the main body portion (e.g., approximately <NUM> millimeters to a blunt rounded portion <NUM> having the shape of a truncated spherical cap. The spherical cap extends distally for approximately <NUM> millimeters. The spherical cap has a longitudinal of approximately <NUM> millimeters and a lateral radius of approximately <NUM> millimeters. In the illustrated embodiment, the applicator head has a hollow cavity <NUM> for a portion of the length from the proximal mounting end <NUM>. The cavity reduces the overall mass of the applicator head to reduce the energy required to reciprocate the applicator head as described below.

In the illustrated embodiment, percussive massage applicator <NUM> is assembled by positioning and securing the motor assembly <NUM> in the upper body portion <NUM> as described above. A cable (not shown) from the motor <NUM> in the motor assembly is connected to the five-pin second plug <NUM>.

After installing the motor assembly <NUM>, the reciprocation assembly <NUM> is installed in the enclosure <NUM> by first attaching the flexible interconnection linkage <NUM> to the crank engagement bearing holder <NUM> by threading the first threaded interconnect rod <NUM> into the longitudinal central bore <NUM>. The first threaded interconnect rod is secured within the longitudinal central bore by engaging the bearing holder setscrew <NUM> into the threaded radial bore <NUM>. The annular bearing <NUM> is installed within the cylindrical cavity <NUM> of the bearing bracket and is secured therein by positioning the lower end wall <NUM> over the bearing and securing the lower end wall with the screws <NUM>. It should be understood that the annular bearing can be installed either before or after the bearing bracket is attached to the flexible linkage.

The crank engagement bearing holder <NUM> and the connected flexible interconnection linkage <NUM> are installed by positioning the central bore <NUM> of the annular bearing <NUM> over the cylindrical crank pivot <NUM> of the eccentric crank <NUM> with the flexible interconnection linkage aligned with the longitudinal axis <NUM>. The second threaded interconnect rod <NUM> is directed toward the bore <NUM> of the cylinder body <NUM> within the cylindrical outer sleeve <NUM> at the distal end of the percussive massage applicator <NUM>.

The applicator head <NUM> is attached to the piston <NUM> by threading the engagement portion <NUM> of the applicator head into the threaded first portion <NUM> of the piston. The interconnected applicator head and piston are then installed through the bore <NUM> of the cylinder body <NUM> to engage the second bore <NUM> of the piston with the second threaded interconnector rod <NUM> of the flexible interconnection linkage <NUM>. The interconnected applicator had and the piston are rotated within the bore of the cylinder body to thread the second bore of the piston onto the second threaded interconnect rod. When the second bore and the second threaded interconnector rod are fully engaged as shown in <FIG>, for example, the piston setscrew <NUM> is threaded into the third bore <NUM> of the piston to engage the threads of the second threaded interconnect rod of the flexible linkage to secure the piston to the flexible linkage. In the illustrated embodiment, the interconnected threads of the piston and the second threaded interconnect rod are configured such that the third bore of the piston is directed generally downward as shown in <FIG> and is thereby accessible to tighten the piston setscrew within the third bore. After the piston is secured to the flexible linkage, the applicator head may be unthreaded from the piston without unthreading the piston from the flexible linkage to allow the applicator head to be removed and replaced without having to remove the piston.

After installing the reciprocation assembly <NUM>, as described above, the lower body portion <NUM> is installed by aligning the lower body portion with the upper body portion <NUM> and securing the two body portions together using the screws <NUM> (<FIG>). The main body endcap <NUM> is then placed over the proximal ends of the two body portions to engage the protrusions <NUM> of the endcap with the L-shaped notches <NUM> of the two body portions. The endcap is then secured to prevent inadvertent removal by inserting the screw <NUM> through the bore <NUM> and into the material of the lower body portion.

The battery assembly <NUM> is installed in the battery assembly receiving enclosure <NUM> of the lower body portion <NUM> of the percussive massage applicator <NUM> and electrically and mechanically engaged as described above. The battery assembly may be charged while installed; or the battery assembly may be charged while removed from the percussive massage applicator.

The operation of the percussive massage applicator <NUM> is illustrated in <FIG>, which are views looking up at the motor assembly in the upper body portion <NUM> with the lower cover <NUM> and the battery assembly <NUM> removed. In <FIG>, the eccentric crank <NUM> attached to the shaft <NUM> of the motor <NUM> is shown at a first reference position, which is designated as the <NUM> o'clock position. In this first reference position, the cylindrical crank pivot <NUM> on the outer surface <NUM> of the eccentric crank is at a most proximal location (nearest the top of the illustration in <FIG>). The crank pivot is positioned in alignment with the longitudinal axis <NUM>. The crank engagement bearing holder <NUM>, the flexible interconnection linkage <NUM>, the piston <NUM> and the applicator head <NUM> are all aligned with the longitudinal axis. In this first position, the distal end of the applicator head extends by a first distance D1 from the distal end of the outer sleeve <NUM>.

In <FIG>, the shaft <NUM> of the motor <NUM> has rotated the eccentric crank <NUM> clockwise <NUM> degrees (as viewed in <FIG>). Accordingly, the cylindrical crank pivot <NUM> on the eccentric crank is now positioned to the right of the shaft of the motor at a second position designated as the <NUM> o'clock position. The central bore <NUM> of the annular bearing <NUM> within the crank engagement bearing holder <NUM> must move to the right because of the engagement with the cylindrical crank pivot. The piston <NUM> is constrained by the bore <NUM> of the cylinder body <NUM> (<FIG>) to remain aligned with the longitudinal axis <NUM>. The second end <NUM> of the flexible interconnection linkage <NUM> remains aligned with the piston because of the second threaded interconnect rod <NUM>. The first end <NUM> of the flexible interconnection linkage remains aligned with the crank engagement bearing holder <NUM> because of the first threaded interconnect rod <NUM>. The smaller middle portion <NUM> of the flexible interconnection linkage allows the flexible interconnection to bend to the right to allow the crank engagement bearing holder to tilt to the right as shown. In addition to moving to the right and away from the longitudinal axis, the cylindrical crank pivot has also moved distally away from the proximal end of the percussive massage applicator <NUM>, which causes the crank engagement bearing holder to also move distally. The distal movement of the crank engagement bearing holder is coupled to the piston via the flexible interconnector to push the piston longitudinally within the cylinder. The longitudinal movement of the piston causes the applicator head <NUM> to extend further outward to a second distance D2 from the distal end of the outer sleeve <NUM>. The second distance D2 is greater than the first distance D1.

In <FIG>, the shaft <NUM> of the motor <NUM> has rotated the eccentric crank <NUM> clockwise an additional <NUM> degrees to a position designated as the <NUM> o'clock position. Accordingly, the cylindrical crank pivot <NUM> is again aligned with the longitudinal axis <NUM>. The crank engagement bearing holder <NUM> and the flexible interconnection linkage <NUM> have returned to the initial straight-line configuration in alignment with the piston <NUM>. The cylindrical crank pivot has moved further from the proximal end of the percussive massage applicator <NUM>. Thus, the crank engagement bearing holder and the flexible interconnection linkage push the piston longitudinally within the bore <NUM> of the cylinder body <NUM> to cause the applicator head <NUM> to extend further outward to a third distance D3 from the distal end of the outer sleeve <NUM>. The third distance D3 is greater than the second distance D2.

In <FIG>, the shaft <NUM> of the motor <NUM> has rotated the eccentric crank <NUM> clockwise an additional <NUM> degrees. Accordingly, the cylindrical crank pivot <NUM> is now positioned to the left of the shaft of the motor at a fourth position designated as the <NUM> o'clock position. The piston <NUM> is constrained by the bore <NUM> of the cylinder body <NUM> to remain aligned with the longitudinal axis <NUM>. The smaller middle portion <NUM> of the flexible interconnection linkage <NUM> allows the flexible interconnection linkage to bend to the left to allow the crank engagement bearing holder <NUM> to tilt to the left as shown. In addition to moving to the left and away from the longitudinal axis, the cylindrical crank pivot has also moved proximally toward the proximal end of the percussive massage applicator <NUM>. The proximal movement pulls the piston longitudinally within the cylinder to cause the applicator head <NUM> to retreat proximally to a fourth distance D4 from the distal end of the outer sleeve <NUM>. The fourth distance D4 is less than the third distance D2 and is substantially the same as the second distance D2.

A further rotation of the shaft <NUM> of the motor <NUM> by an additional <NUM> degrees clockwise returns the eccentric crank <NUM> to the original <NUM> o'clock position shown in <FIG> to return the cylindrical crank pivot <NUM> to the most proximal location. This further rotation causes the distal end of the applicator head <NUM> to retreat to the original first distance D1 from the outer sleeve <NUM>. Continued rotation of the shaft of the motor causes the distal end of the applicator head to repeatedly extend and retreat with respect to the outer sleeve. By placing the distal end of the applicator head on a body part to be massaged, the applicator head applies percussive treatment to the selected body part.

In the illustrated embodiment, the axis of the cylindrical crank pivot <NUM> is located approximately <NUM> millimeters from the axis of the shaft <NUM> of the motor <NUM>. Accordingly, the cylindrical crank pivot moves a total longitudinal distance of approximately <NUM> millimeters from the <NUM> o'clock position of <FIG> to the <NUM> o'clock position of <FIG>. This results in a <NUM>-millimeter stroke distance of the distal end of the applicator head <NUM> from the fully retreated first distance D <NUM> to the fully extended third distance D3.

Conventional linkage systems between a crank and a piston have two sets of bearings. A first bearing (or set of bearings) couples a first end of a drive rod to a rotating crank. A second bearing (or set of bearings) couples a second end of a drive rod to a reciprocating piston. When the piston reaches each of the two extremes of the reciprocating motion, the piston must abruptly change directions. The stresses caused by the abrupt changes in direction are applied against the bearings at each end of the drive rod as well as to the other components in the linkage system. The abrupt changes of direction also tend to generate substantial noise.

The reciprocating linkage system <NUM> described herein eliminates a second bearing (or set of bearings) at the piston <NUM>. The piston is linked to the other components of the linkage via the flexible interconnection linkage <NUM>, which bends as the cylindrical crank pivot <NUM> rotates about the centerline of the shaft <NUM> of the motor <NUM>. The flexible interconnect cushions the abrupt changes in direction at each end of the piston stroke. For example, as the applicator head <NUM> and the piston reverse direction from distal movement to proximal movement at the <NUM> o'clock position, the flexible interconnect may stretch by a small amount during the transition. The stretching of the flexible interconnect reduces the coupling of energy through the linkage system to the bearing <NUM> (<FIG>) and the cylindrical crank pivot. Similarly, as the applicator head and the piston reverse direction from proximal movement to distal movement at the <NUM> o'clock position, the flexible interconnect may compress by a small amount during the transition. The compression of the flexible interconnect reduces the coupling of energy though the linkage system to the bearing and the cylindrical crank pivot. Thus, in addition to eliminating the bearing at the piston end of the linkage system, the flexible interconnect also reduces the stress on the bearing at the crank end of the linkage system.

The flexible interconnection linkage <NUM> in the linkage assembly <NUM> also reduces the noise of the operating percussive massage applicator <NUM>. The effectively silent stretching and compressing of the flexible interconnect when the reciprocation reverses direction at the <NUM> o'clock and <NUM> o'clock positions, respectively, eliminates the conventional metal-to-metal interaction that would occur if the linkage system were coupled to the piston <NUM> with a conventional bearing.

As discussed above, the bullet-shaped applicator head <NUM> is removably threaded onto the piston <NUM>. The bullet-shaped applicator head may be unscrewed from the piston and replaced with a spherical-shaped applicator head <NUM>, shown in <FIG>. A spherical-shaped distal end portion <NUM> of the applicator head extends from an applicator main body portion <NUM>, which corresponds to the main body portion <NUM> of the bullet-shaped applicator head. The spherical-shaped applicator head includes an engagement portion (not shown) corresponding to the engagement portion <NUM> of the bullet-shaped applicator head. The spherical-shaped applicator head may be used to apply percussive massage to larger areas of the body to reduce the force on the treated area and to allow the angle of application to be varied.

The bullet-shaped applicator head <NUM> may also be unscrewed and replaced with a disk-shaped applicator head <NUM> shown in <FIG>. A disk-shaped distal end portion <NUM> of the applicator head extends from an applicator main body portion <NUM>, which corresponds to the main body portion <NUM> of the bullet-shaped applicator head. The disk-shaped applicator head includes an engagement portion (not shown) corresponding to the engagement portion <NUM> of the bullet-shaped applicator head. The disk-shaped applicator head may be used to apply percussive massage to a larger area of the body to reduce the force on the treated area.

The bullet-shaped applicator head <NUM> may also be unscrewed and replaced with a Y-shaped applicator head <NUM> shown in <FIG>. A Y-shaped distal end portion <NUM> of the applicator head extends from an applicator main body portion <NUM>, which corresponds to the main body portion <NUM> of the bullet-shaped applicator head. The Y-shaped applicator head includes an engagement portion (not shown) corresponding to the engagement portion <NUM> of the bullet-shaped applicator head. The Y-shaped applicator head includes an applicator base <NUM>. A first finger <NUM> and a second finger <NUM> extend from the applicator base and are spaced apart as shown. The two fingers of the Y-shaped applicator head may be used to apply percussive massage to muscles on both sides of the spine without applying direct pressure to the spine.

The portable electromechanical percussive massage applicator <NUM> may be provided with power and controlled in a variety of manners. <FIG> illustrates an exemplary battery control circuit <NUM>, which comprises in part the circuitry mounted on the battery controller PCB <NUM>. In <FIG>, previously identified elements are numbered with like numbers as before.

The battery control circuit <NUM> includes the power adapter input jack <NUM>. In the illustrated embodiment, the input power provided to the jack as a DC input voltage of approximately <NUM> volts DC. Other voltages may be used in other embodiments. The input voltage is provided with respect to a circuit ground reference <NUM>. The input voltage is applied across a voltage divider circuit comprising a first voltage divider resistor <NUM> and a second voltage divider resistor <NUM>. The resistances of the two resistors are selected to provide a signal voltage of approximately <NUM> volts when the DC input voltage is present. The signal voltage is provided through a high resistance voltage divider output resistor <NUM> as a DCIN signal.

The DC input voltage is provided through a rectifier diode <NUM> and a series resistor <NUM> to a DC input bus <NUM>. The rectifier diode prevents damage to the circuitry if the polarity of the DC input voltage is inadvertently reversed. The voltage on the DC input bus is filtered by an electrolytic capacitor <NUM>.

The DC input voltage on the DC input bus <NUM> is provided through a <NUM>-volt Zener diode <NUM> and a series resistor <NUM> to the voltage input of a voltage regulator <NUM>. The input of the voltage regulator is filtered by a filter capacitor <NUM>. In the illustrated embodiment, the voltage regulator is a HT7550-<NUM> voltage regulator, which is commercially available from Holtek Semiconductor, Inc. , of Taiwan. The voltage regulator provides an output voltage of approximately <NUM> volts on a VCC bus <NUM>, which is filtered by a filter capacitor <NUM>.

The voltage on the VCC bus is provided to a battery charger controller <NUM>. The controller receives the DCIN signal from the voltage divider output resistor <NUM>. The battery charger controller is responsive to the active high state of the DCIN signal to operate in the manner described below to control the charging of the battery unit <NUM>. When the DCIN signal is low to indicate that the charging voltage is not present, the controller does not operate.

The battery charger controller <NUM> provides a pulse width modulation (PWM) output signal to the input of a buffer circuit <NUM>, which comprises a PNP bipolar transistor <NUM> having a collector connected to the circuit ground reference <NUM>. The PNP transistor has an emitter connected to the emitter of an NPN bipolar transistor <NUM>. The bases of the two transistors are interconnected and form the input to the buffer circuit. The two transistor bases are connected to receive the PWM output signal from the controller. The commonly connected bases are also connected to the commonly connected emitters via a base-emitter resistor <NUM>. The collector of the NPN connected to the VCC bus <NUM>.

The commonly connected emitters of the PNP transistor <NUM> and the NPN transistor <NUM> are connected to an anode of a protection diode <NUM>. A cathode of the protection diode is connected to the VCC bus <NUM>. The protection diode prevents the voltage on the commonly connected emitters from exceeding the voltage on the VCC bus by more than one forward diode drop (e.g., approximately <NUM> volt). The commonly connected emitters of the two transistors are also connected through a resistor <NUM> to a first terminal of a coupling capacitor <NUM>. A second terminal of the coupling capacitor is connected to a gate terminal of a power metal oxide semiconductor transistor (MOSFET) <NUM>. In the illustrated embodiment, the MOSFET comprises an STP9527 P-Channel Enhancement Mode MOSFET, which is commercially available from Stanson Technology in Mountain View, California. The gate terminal of the MOSFET is also connected to an anode of a protection diode <NUM>, which has a cathode connected a source (S) terminal of the MOSFET. The protection diode prevents the voltage on the gate terminal from exceeding the voltage on the source terminal by more than the forward diode voltage of the protection diode (e.g., approximately <NUM> volt). The gate terminal of the MOSFET is also connected to the source terminal of the MOSFET by a pull-up resistor <NUM>. The source of the MOSFET is connected to the DC input bus <NUM>.

A drain (D) of the MOSFET <NUM> is connected to an input node <NUM> of a buck converter <NUM>. The buck converter further includes an inductor <NUM> connected between the input node and an output node <NUM>. The output node (also identified as VBAT) is connected to a positive terminal of the battery unit <NUM>. A negative terminal of the battery unit is connected to the circuit ground <NUM> via a low-resistance current sensing resistor <NUM>. The input node is further connected to a cathode of a free-wheeling diode <NUM>, which has an anode connected to the circuit ground. A first terminal of a resistor <NUM> is also connected to the input node. A second terminal of the resistor is connected to a first terminal of a capacitor <NUM>. A second terminal of the capacitor is connected to the circuit ground. Accordingly, a complete circuit path is provided from the circuit ground, through the free-wheeling diode, through the inductor, through the battery unit, and through the current sensing resistor back to the circuit ground.

The battery charger controller <NUM> controls the operation of the buck converter <NUM> by applying an active low pulse on the PWM output connected to the buffer circuit <NUM>, which responds by pulling down the voltage on the commonly connected emitters of the two transistors <NUM>, <NUM> to a voltage near the ground reference potential. The low transition to the ground reference potential is coupled through the resistor <NUM> and the coupling capacitor <NUM> to the gate terminal of the MOSFET <NUM> to turn on the MOSFET and couple the DC voltage on the DC input bus <NUM> to the input node <NUM> of the buck converter <NUM>. The DC voltage causes current to flow though the inductor <NUM> to the battery unit <NUM> to charge the battery unit. When the PWM signal from the battery charger controller is turned off (returned to an inactive high state), the MOSFET is turned off and no longer provides a DC voltage to the input node of the buck converter; however, the current flowing in the inductor continues to flow through the battery unit and back through the free-wheeling diode as the inductor discharges to continue charging the battery unit until the inductor is discharged. The width and repetition rate of the active low pulses generated by the battery charger controller determine the current applied to charge the battery unit in a known manner. In the illustrated embodiment, the PWM signal has a nominal repetition frequency of approximately <NUM>.

The battery charger controller <NUM> controls the width and repetition rate of the pulses applied to the MOSFET <NUM> in response to feedback signals from the battery unit <NUM>. A battery voltage sensing circuit <NUM> comprises a first voltage feedback resistor <NUM> and a second voltage feedback resistor <NUM>. The two resistors are connected in series from the output node <NUM> to the circuit ground <NUM> and are thus connected across the battery unit. A common voltage sensing node <NUM> of the two resistors is connected to a voltage sensing (VSENSE) input of the controller. The battery charger controller monitors the voltage sensing input to determine the voltage across the battery unit to determine when the battery unit is at or near a maximum voltage of approximately <NUM> volts such that the charging rate should be reduced. In the illustrated embodiment, a filter capacitor <NUM> is connected from the voltage sensing node to the circuit ground to reduce noise on the voltage sensing node.

As described above, the negative terminal of the battery unit <NUM> is connected to the circuit ground <NUM> via the low-resistance current sensing resistor <NUM>, which may have a resistance of, for example, <NUM> ohm. A voltage develops across the current sensing resistor proportional to the current flowing through the battery unit when charging. The voltage is provided as an input to a current sensing (ISENSE) input of the battery charger controller <NUM> via a high-resistance (e.g., <NUM>,<NUM>-ohm) resistor <NUM>. The current sensing input is filtered by a filter capacitor <NUM>. The battery charger controller monitors the current flowing through the battery unit and thus through the current sensing resistor to determine when the current flow decreases as the charge on the battery unit nears a maximum charge. The battery charger controller may also respond to a large current through the battery unit and reduce the pulse width modulation to avoid exceeding a maximum magnitude for the charging current.

The output node <NUM> of the buck converter <NUM> is also the positive voltage node of the battery unit <NUM>. The positive battery voltage node is connected to a first terminal <NUM> of the on-off switch <NUM>. A second terminal <NUM> of the on-off switch is connected to a voltage output terminal <NUM>, which is identified as VOUT. The voltage output terminal is connected to the first contact 206A of the battery assembly <NUM>. The first contact of the battery assembly engages the first leaf spring contact 204A when the battery assembly is inserted into the battery receiving tray <NUM>. When the switch is closed, the first terminal and the second terminal of the switch are electrically connected to couple the battery voltage to the voltage output terminal. The voltage output terminal is coupled to an output voltage sensing circuit <NUM>, which comprises a first voltage divider resistor <NUM> and a second voltage divider resistor <NUM> connected in series between the voltage output terminal and the circuit ground. A common node <NUM> between the two resistors is connected to a VOUT sensing input of the battery charger controller <NUM>. The common node is also connected to the circuit ground by a Zener diode <NUM>, which clamps the voltage at the common node to no more than <NUM> volts. The resistances of the two resistors are selected such that when the switch is closed and the output voltage is applied to the output terminal, the voltage on the common node and the VOUT sensing input of the controller is approximately <NUM> volts to indicate that the switch is closed and that the battery voltage is being provided to the selected terminal of the battery assembly.

A second contact 206B of the battery assembly <NUM> is connected to a battery charge (CHRG) output signal of the battery charger controller <NUM> via a signal line <NUM>. The battery charge output signal is an analog signal having a magnitude indicative of the charging state of the battery unit <NUM>. The second battery assembly contact engages the second leaf spring contact 204B when the battery assembly is inserted into the battery receiving tray <NUM>.

A third contact 206C of the battery assembly <NUM> is connected to the negative terminal of the battery unit <NUM> via a line <NUM> and is identified as the battery ground (GND) that is provided to the motor control PCB <NUM> as described below. Note that the battery ground is coupled to the circuit ground by the <NUM>-ohm current sensing resistor <NUM>. The current flowing out of the positive terminal of the battery unit to the motor control PCB and back to the negative terminal of the battery unit does not flow through the current sensing resistor. The third battery assembly contact engages the third leaf spring contact 204C when the battery assembly is inserted into the battery receiving tray <NUM>.

The battery charger controller <NUM> drives the dual-color LEDs <NUM> on the battery controller PCB. The controller includes a first output (LEDR) that drives the red-emitting LEDs in the dual-color LEDs and includes a second output (LEDG) that drives the green-emitting LED in the dual-color LEDs. A first current limiting resistor <NUM> couples the first output to the anodes of the red-emitting LEDs in a first set of three dual-color LEDs. A second current limiting resistor <NUM> couples the second output to the anodes of the green-emitting LEDs in the first set of three dual-color LEDs. A third current limiting resistor <NUM> couples the first output to the anodes of the red-emitting LEDs in a second set of three dual-color LEDs. A fourth current limiting resistor <NUM> couples the second output to the anodes of the green-emitting LEDs in the second set of three dual-color LEDs.

In the illustrated embodiment, the dual-color LEDs <NUM> are driven with different duty cycles to indicate the present state of charge of the battery unit <NUM>. For example, in a first state, the first output (LEDR) of the controller <NUM> is driven with a <NUM> percent duty cycle and the second output (LEDG) of the controller is not driven such that only the red-emitting LEDs are illuminated to indicate that the battery unit needs be charged. In a second state, the first output is driven with a <NUM> percent duty cycle and the second output is driven with a <NUM> percent duty cycle such that the resulting perceived color is a mixture of red and green. In a third state, the first output and the second output are both driven with a respective <NUM> percent duty cycle. In a fourth state, the first output is driven with a <NUM> percent duty cycle and the second output is driven with a <NUM> percent duty cycle. In a fifth state, the first output is not driven and the second output is driven with a <NUM> percent duty cycle such that the color is entirely green to indicate that the battery unit is at or near a fully charged state. The duty cycles at which the two outputs are driven may be interleaved such that the two outputs are not on at the same time. Other than at the first state, the duty cycles are repeated at a rate sufficiently high that the enabled LEDs appear to be on at all times without a perceptible flicker. When the battery controller is in the first state, the battery controller may blink the red-emitting LEDS on and off at a perceptible rate to remind the user that the charge on the battery is low and should be charged before continuing to use the percussive massage applicator <NUM>. In certain embodiments, the first state may be further segmented into two charge ranges. In a first range of charges within the first state, the red LEDs are driven with a constant illumination to indicate that the charge on the charge on the battery unit is low and that the battery unit should be charged soon. In a second range of charges, the red LEDs are blinked to indicate that the charge in the battery unit is very low and that the battery unit should be charged promptly.

<FIG> illustrates an exemplary motor controller circuit <NUM>, which comprises in part the circuitry mounted on the motor controller PCB <NUM>. In <FIG>, previously identified elements are numbered with like numbers as before. As described above, the battery assembly <NUM> provides the positive battery output voltage VOUT on the first leaf spring contact 204A of the receiving tray <NUM> when the battery assembly is inserted into the receiving tray. The positive battery output voltage is identified as VBAT in <FIG>. The CHRG signal from the battery assembly is provided to the second leaf spring contact 204B when the battery assembly is inserted into the receiving tray. The battery ground (GND) is provided to the third leaf spring contact 204C when the battery assembly is inserted into the receiving tray. The DC voltage, the battery ground and the CHRG signal are coupled via a three-wire cable <NUM> to a cable jack <NUM>. The first plug <NUM> on the motor controller PCB plugs into the cable jack to receive the DC voltage on a first pin <NUM>, to receive the CHRG signal on a second pin <NUM>, and to receive the battery ground (GND) on a third pin <NUM>. The battery ground (GND) from the third pin of the first plug is electrically connected to a local circuit ground <NUM>.

The DC voltage (VBAT) on the first pin <NUM> of the first plug <NUM> is filtered by a filter capacitor <NUM> connected between the first pin of the first plug and the local circuit ground <NUM>. The DC voltage is also provided to a first terminal of a current limiting resistor <NUM>. A second terminal of the current limiting resistor is provided to the voltage input terminal of a voltage regulator <NUM>. The voltage regulator receives the battery voltage and converts the battery voltage to <NUM> volts. The <NUM>-volt output of the voltage regulator is provided on a local VCC bus <NUM>. The local VCC bus is filtered by a filter capacitor <NUM>, which is connected between the local VCC bus and the local circuit ground. In the illustrated embodiment, the voltage regulator is a 78L05 three-terminal regulator, which is commercially available from a number of manufacturers, such as, for example, National Semiconductor Corporation of Santa Clara, California.

The CHRG signal on the second pin <NUM> of the first plug <NUM> is provided to a charge (CHRG) input of a motor controller <NUM> via a series resistor <NUM>. The charge input to the motor controller is filtered by a filter capacitor <NUM>. The motor controller receives the <NUM> volt supply voltage from the VCC bus <NUM>.

The DC voltage from the first pin <NUM> of the first plug is also provided directly to a first pin <NUM> of the five-pin second plug <NUM>. The second plug <NUM> is connectable to a second jack <NUM> having a corresponding number of contacts. The second jack is connected via a five-wire cable <NUM> to the motor <NUM>.

A second pin <NUM> of the second plug is a tachometer (TACH) pin, which receives a tachometer signal from the motor <NUM> indicative of the present angular velocity of the motor. For example, the tachometer signal may comprise one pulse for every revolution of the shaft <NUM> of the motor or one pulse per partial revolution. The tachometer signal is provided to a first terminal of a first resistor <NUM> in a voltage divider circuit <NUM>. A second terminal of the first resistor is connected to a first terminal of a second resistor <NUM> in the voltage divider circuit. A second terminal of the second resistor is connected to the local circuit ground. A common node <NUM> between the first and second resistors in the voltage divider circuit is connected to the base of an NPN bipolar transistor <NUM>. An emitter of the NPN transistor is connected to ground. A collector of the NPN transistor is connected to the VCC bus <NUM> via a pull-up resistor <NUM>. The NPN transistor inverts and buffers the tachometer signal from the motor and provides the buffered signal to a TACH input of the motor controller. The buffered signal varies between +<NUM> volts (VCC) and the local circuit ground potential when the tachometer signal varies between the local circuit ground potential and the DC voltage potential from the battery.

A third pin <NUM> of the second plug <NUM> is a clockwise/counterclockwise (CW/CCW) signal generated by the motor controller <NUM> and coupled to the third pin via a current limiting resistor <NUM>. The state of the CW/CCW signal determines the rotational direction of the motor <NUM>. In the illustrated embodiment, the CW/CCW signal is maintained at a state to cause clockwise rotation; however, the rotation can be changed to the opposite direction in other embodiments.

A fourth pin <NUM> of the second plug <NUM> is connected to the local circuit ground <NUM>, which corresponds to the battery ground connected to the negative terminal of the battery unit <NUM> in <FIG>.

A fifth pin <NUM> of the second plug <NUM> receives a pulse width modulation (PWM) signal generated by the motor controller <NUM>. The PWM signal is coupled to the fifth pin via a current limiting resistor <NUM>. The motor <NUM> is responsive to the duty cycle and the frequency of the PWM signal to rotate at a selected angular velocity. As described below, the motor controller controls the PWM signal to maintain the angular velocity at one of three selected rotational speeds.

The motor controller <NUM> has a switch-in (SWIN) input that receives an input signal from the pushbutton switch <NUM>. The pushbutton switch has a first contact connect to the local circuit ground <NUM> and has a second contact connected to the VCC bus <NUM> via a pull-up resistor <NUM>. The second contact is also connected to the local circuit ground via a filter capacitor <NUM>. The second is also connected to the SWIN input of the motor controller. The input signal is held high by the pull-up resistor until the switch contacts are closed by actuating the pushbutton switch. When the switch is actuated to close the contacts, the input signal is pulled to <NUM> volts (e.g., the potential on the local circuit ground). The filter capacitor reduces the switch contact bounce noise. The motor controller may include internal debounce circuitry to eliminate the effects of the switch contact bounce. The motor controller is initialized in an off-state wherein no PWM signal is provided to the motor <NUM>, and the motor does not rotate. The motor controller is responsive to a first activation of the switch to advance from the off-state to a first on-state wherein the PWM signal provided to the motor is selected to cause the motor to rotate at a first (low) speed. A subsequent activation of the switch advances the motor controller to a second on-state wherein the PWM signal provided to the motor is selected to cause the motor to rotate at a second (medium) speed. A subsequent activation of the switch advances the motor controller to a third on-state wherein the PWM signal provided to the motor is selected to cause the motor to rotate at a third (high) speed. A subsequent activation of the switch returns the motor controller to the initial off-state wherein no PWM signal is provided to the motor and the motor does not rotate. In the illustrated embodiment, the three rotational speeds of the motor are <NUM>,<NUM> rpm (low), <NUM>,<NUM> rpm (medium) and <NUM>,<NUM> rpm (high).

The motor controller <NUM> generates a nominal PWM signal associated with the currently selected on-state (e.g., low, medium or high speed). Each on-state corresponds to a selected rotational speed as described above. The motor controller monitors the tachometer signal (TACH) received from the pin <NUM> of the five-pin plug <NUM> via the voltage divider <NUM> and the NPN transistor <NUM>. If the received tachometer signal indicates that the motor speed is below the selected speed, the motor controller adjusts the PWM signal (e.g. increases the pulse width or increases the repetition rate or both) to increase the motor speed. If the received tachometer signal indicates that the motor speed is above the selected speed, the motor controller adjusts the PWM signal (e.g. decreases the pulse width or decreases the repetition rate or both) to decrease the motor speed.

The motor controller <NUM> generates a first set of three LED control signals (LEDS1, LEDS2, LEDS3). The first signal (LEDS1) in the first set is coupled via a current limiting resistor <NUM> to the first speed indication LED 166A. The first signal in the first set is activated to illuminate the first speed indication LED when the motor controller is in the first on-state to drive the motor at the first (low) speed. The second signal (LEDS2) in the first set is coupled via a current limiting resistor <NUM> to the second speed indication LED 166B. The second signal in the first set is activated to illuminate the second speed indication LED when the motor controller is in the second on-state to drive the motor at the second (medium) speed. The third signal (LEDS3) in the first set is coupled via a current limiting resistor <NUM> to the third speed indication LED 166C. The third signal in the first set is activated to illuminate the third speed indication LED when the motor controller is in the third on-state to drive the motor at the third (high) speed.

The motor controller <NUM> is further responsive to the CHRG signal from the input plug <NUM>. As discussed above, the CHRG signal is generated by the battery charger controller <NUM> to indicate the state of charge of the battery unit <NUM>. The motor controller determines the present state of charge of the battery unit from the CHRG input signal and displays the state of charge on the five battery charge state LEDs 168A, 168B, 168C, 168D, 168E which are visible through the main body endcap <NUM>. The motor controller generates a second set of five LED control signals (LEDC1, LEDC2, LEDC3, LEDC4, LEDC5). The first signal (LEDC1) in the second set is coupled via a current limiting resistor <NUM> to the first charge LED 168A. The first signal in the second set is activated to illuminate the first charge indication LED when the battery unit has a lowest range of charge. The motor controller may blink the first charge indication LED at a perceptible rate to indicate the lowest range of charge. The color (e.g., red) of the light emitted by the first charge LED may differ from the color (e.g., green) of the light emitted by the other LEDS to further indicate the lowest range of charge (e.g., no more than <NUM> percent of charge remaining). The second signal (LEDC2) in the second set is coupled via a current limiting resistor <NUM> to the second charge indication LED 168B. The second signal in the second set is activated to illuminate the second charge indication LED when the battery unit has a second range of charge (e.g., <NUM>-<NUM> percent of charge remaining). The third signal (LEDC3) in the second set is coupled via a current limiting resistor <NUM> to the third charge indication LED 168C. The third signal in the second set is activated to illuminate the third charge indication LED when the battery unit has a third range of charge (e.g., <NUM>-<NUM> percent of charge remaining). The fourth signal (LEDC4) in the second set is coupled via a current limiting resistor <NUM> to the fourth charge indication LED 168D. The fourth signal in the second set is activated to illuminate the fourth charge indication LED when the battery unit has a fourth range of charge (e.g., <NUM>-<NUM> percent of charge remaining). The fifth signal (LEDC5) in the second set is coupled via a current limiting resistor <NUM> to the fifth charge indication LED 168B. The fifth signal in the second set is activated to illuminate the fifth charge indication LED when the battery unit has a fifth range of charge (e.g., <NUM>-<NUM> percent of charge remaining). It should be understood that the ranges of charge are only approximations and are provided as examples.

The portable electromechanical percussive massage applicator <NUM> described herein advantageously allows a massage therapist to effectively apply percussion massage over an extended time duration without excessive tiring and without being tethered to an electrical power cord. The reduced noise level of the portable electromechanical percussive massage applicator described herein allows the device to be used in quiet environment such that the person being treated with the device is able to relax and enjoy any ambient music or other soothing sounds provided in the treatment room.

Claim 1:
A battery-powered percussive massage device comprising:
a main housing (<NUM>) having a main enclosure (<NUM>, <NUM>) that encloses a piston (<NUM>);
an applicator head (<NUM>; <NUM>; <NUM>; <NUM>) removably coupled to the piston (<NUM>), at least a portion of the applicator head exposed outside the main housing (<NUM>);
a battery assembly receiving enclosure (<NUM>) extending from the main enclosure (<NUM>, <NUM>); and
a battery assembly (<NUM>) positionable in the battery assembly receiving enclosure (<NUM>) and removably secured to the battery assembly receiving enclosure such that a first portion of the battery assembly is positioned within the battery assembly receiving enclosure and a second portion of the battery assembly extends from the battery assembly receiving enclosure, wherein the battery assembly (<NUM>) comprises a battery unit (<NUM>),
characterised in that:
the second portion of the battery assembly has an outer gripping surface (<NUM>) configured to be gripped by one hand;
the main housing (<NUM>) encloses a motor (<NUM>) and, in operation, the piston (<NUM>) is caused to reciprocate along a longitudinal axis by the motor;
the battery assembly (<NUM>) further comprises a battery controller printed circuit board (<NUM>) positioned within said second portion, the battery controller printed circuit board including an input jack (<NUM>) to receive electrical charging power and a battery charger controller (<NUM>) that controls said charging power received via said input jack to charge the battery unit (<NUM>);
a plurality of light-emitting diodes (LEDs) (<NUM>) is positioned around the periphery of said battery controller printed circuit board (<NUM>) within the second portion of the battery assembly (<NUM>), said LEDs (<NUM>) driven by said battery controller (<NUM>) so that the colour of the LEDs indicates the charged state of the battery assembly (<NUM>); and
a translucent plastic ring (<NUM>) is aligned with the LEDs (<NUM>) through which light from the LEDs is emitted so as to be seen externally of the second portion of the battery assembly.