Light-emitting element for power tool

Abstract

A power tool includes a tool housing having an outer surface supporting a portion of an elongated LED filament. The LED filament includes a flexible substrate and micro LEDs disposed on the substrate in an electrical connection arrangement in such a manner that light is emitted from the LED filament in a direction perpendicular to the substrate in an angular range from 0 degree to 360 degrees. The relatively small diameter and large flexibility of the LED filament and the intense illumination provided by the LED filament make the LED filament suitable for use as a lighting device in small devices such as hand-held power tools.

Description

Light-emitting elements for power tools Background Technology

[0001] The use of lighting elements such as those including light-emitting diodes (LEDs) to provide enhanced and ring lights has become popular in some automobiles and relatively larger, high-end products. However, using LED-included lighting elements in smaller devices with limited available package space can be more challenging. For example, providing enhanced illumination or workpiece lighting using LEDs in handheld power tools can be challenging because the LEDs may need to be mounted on a printed circuit board and / or wired through the product to the power supply (or the lighting component itself). On the other hand, it is desirable to provide improved workpiece lighting and / or enhanced illumination in handheld power tools without having to enlarge the tool housing or power supply. Summary of the Invention

[0002] LED filament light-emitting components can be used to highlight or enhance tool features and more effectively illuminate workpieces during tooling operations including sawing, grinding, polishing, etching, etc. LED filaments can be used for aesthetic and / or light distribution purposes and are achieved with the high efficiency of conventional light-emitting diodes (LEDs). An LED filament is a thin, elongated lighting element that is sufficiently flexible to allow for sharp rotations relative to multiple axes and to bend into complex shapes. This can be compared to some conventional LED strips, which are flexible around a single axis, such as the axis extending in the width direction of the thin substrate supporting the LED.

[0003] Further advantageously, the filament comprises microLEDs. MicroLEDs (also known as mLEDs or μLEDs) are display technologies based on tiny LED devices that can be used, for example, to directly create colored pixels. In an LED filament, mLEDs are arranged compactly and in series to provide a light intensity greater than some conventional LED strips and to emit light over a wider angular range compared to some conventional LED strips. As used herein, the term “microLED” refers to an LED having a size of a few micrometers, while the term “filament” refers to a long, thin substrate that is substantially equivalent in flexibility in three dimensions, in the form of a filament or cord. Due to its slender structure, relatively high light intensity, and multiaxial flexibility, LED filaments can be assembled and positioned to place the light-emitting components where they are needed, which may vary for each tool type depending on the tool properties and requirements.

[0004] In some embodiments, the LED filament may travel along the outer surface of the tool housing around housing features to create decorative details or provide enhanced illumination of tool housing details. In other embodiments, the LED filament may strategically travel along the outer surface of the tool housing to provide workpiece illumination. In further embodiments, the LED filament may be disposed within the tool housing and arranged to cooperate with transparent portions of the tool housing to provide focused illumination of tool housing details and / or workpiece. The enhanced illumination may be white or a different color, and the color of the enhanced illumination depends on the properties of the specific LED filament used. The LED filament is a low-voltage, low-current device that can be powered by a tool power supply or a separate power supply. As used herein, the term "low voltage" refers to a voltage of less than 5 volts, and the term "low current" refers to a current of less than 200 mA.

[0005] In some embodiments, the LED filament can be arranged as a coil, such as a coil surrounding the nozzle of a rotary power tool. By providing a multi-turn coil, the combined effect of these coils is a brighter and stronger light compared to that obtained by a single LED filament. This effect provides a spotlight or flashlight effect when surrounding the nozzle of a power tool.

[0006] In some embodiments, the LED filament can travel around tool components that are in close proximity to the workpiece during use. For example, when wrapped around the periphery of a sander pad, illumination is propagated from a position close to the workpiece surface onto the workpiece. This close-to-surface light propagation, combined with the LED filament's ability to emit light across a 360-degree range, allows the user to clearly see the surface texture, inspect the surface polishing, and determine whether the surface has been adequately polished.

[0007] In some embodiments, an LED filament can travel around the saw blade to illuminate the sawed area on the workpiece and reduce or eliminate shadow formation. For example, the filament can be placed on the base of a wire saw power tool. More specifically, the filament can extend along the cutout of the base that houses the wire saw blade. The light propagation close to the workpiece and around the saw blade, combined with the LED filament's ability to emit light in a 360-degree range, minimizes or eliminates shadows on the workpiece surface. This can be compared to some conventional tool light emission patterns where the light source is located on the tool housing (e.g., from above the blade), which can cause the saw blade and tool base to cast shadows on the workpiece surface, making the sawing path difficult to see.

[0008] In some embodiments, an LED filament is received in a groove formed on the outer surface of the tool housing. The groove is shaped and sized to receive and retain the LED filament within it. The groove may have a depth dimension less than the diameter of the LED filament, thereby allowing the filament to extend from the groove. In other embodiments, the groove may have a depth dimension greater than the diameter of the LED filament, thereby allowing the filament to be recessed relative to the tool housing. The groove may extend into the tool housing in a direction perpendicular to the tool housing surface, or it may extend into the tool housing in a direction at an acute angle relative to the tool housing surface. In some embodiments, the angle of the groove is selected such that light is emitted in a predetermined direction.

[0009] In some aspects, a power tool includes a tool housing and an electric motor disposed within the tool housing. The electric motor has an output shaft. The power tool includes a machining tool mechanically connected to the output shaft and extending from the tool housing. The machining tool is configured to transmit motion of the output shaft to an attachment of the tool. Furthermore, the power tool includes an elongated LED filament. A portion of the LED filament is supported on a portion of the tool housing. The LED filament includes a substrate and micro-LEDs disposed on the substrate at spaced-apart electrical connections, such that light is emitted from the LED filament in an angular range from 0 degrees to 360 degrees in a direction perpendicular to the substrate.

[0010] In some embodiments, the substrate is sufficiently flexible that the LED filament can be bent around each of the three orthogonal axes with a radius of 5 mm.

[0011] In some embodiments, the portion of the tool housing includes a portion of the outer surface of the tool housing having an external shape, and the portion of the LED filament is arranged on the portion of the tool housing in such a way as to illuminate the external shape.

[0012] In some embodiments, the portion of the tool housing includes a portion of the outer surface of the tool housing having an external shape, and the portion of the LED filament is arranged on the portion of the tool housing in a manner that outlines the external shape.

[0013] In some embodiments, the portion of the tool housing includes a groove, and the groove is fitted to receive and retain the portion of the LED filament. Furthermore, the portion of the LED filament is disposed within the groove.

[0014] In some embodiments, the groove is formed on the outer surface of the tool housing. The groove is shaped and sized such that when the portion of the LED filament is disposed in the groove, the portion of the LED filament protrudes relative to the outer surface of the tool housing.

[0015] In some embodiments, the groove is formed on the outer surface of the tool housing. The groove is shaped and sized such that when the portion of the LED filament is disposed in the groove, the portion of the LED filament is recessed relative to the outer surface of the tool housing.

[0016] In some embodiments, when the groove is viewed in cross-section, the groove axis is defined by a line extending through a first point and a second point, wherein the first point is located midway between the sidewalls of the groove, corresponding to the intersection of the groove and the outer surface of the tool housing, and the second point is located midway between the sidewalls of the groove, corresponding to the blind end of the groove. The groove axis is perpendicular to the portion of the tool housing.

[0017] In some embodiments, when the groove is viewed in cross-section, the groove axis is defined by a line extending through a first point and a second point, wherein the first point is located midway between the sidewalls of the groove, corresponding to the intersection of the groove and the outer surface of the tool housing, and the second point is located midway between the sidewalls of the groove, corresponding to the closed end of the groove. The groove axis forms an acute angle with respect to the portion of the tool housing.

[0018] In some embodiments, the LED filament includes an elongated cylindrical body having a first end and a second end opposite to the first end, a first electrical terminal extending from the first end, and a second electrical terminal extending from the second end, the body having a diameter in the range of 1 mm to 5 mm.

[0019] In some embodiments, the LED filament includes an elongated body having a first end and a second end opposite to the first end, and when the body is arranged in a straight line, the body has a length corresponding to the distance between the first end and the second end. Furthermore, the body supports at least 300 micro-LEDs per meter of body length.

[0020] In some embodiments, the LED filament includes a flexible cylindrical substrate that supports a microLED along its length, and wherein the substrate is covered with a coating that extends along the length of the substrate and around its circumference, such that the coating is concentric with the substrate and surrounds the substrate and the microLED.

[0021] In some embodiments, the power tool is mounted to be connected to a power supply, and the power supply supplies power to the motor and the LED filament.

[0022] In some embodiments, the power tool includes a structure that rests against a workpiece surface when the power tool is in use. The structure has a contact surface that faces and rests against the workpiece when the power tool is in use, and an adjacent surface that abuts the contact surface along an edge. A portion of the tool housing extends along the edge, thereby extending a portion of the LED filament along the edge.

[0023] In some embodiments, the portion of the LED filament is arranged as a coil stack.

[0024] In some embodiments, the portion of the outer surface of the tool housing surrounds the circumference of the tool housing, and the portion of the LED filament surrounds the portion of the outer surface of the tool housing at least twice. Attached Figure Description

[0025] Figure 1 is a side view of a battery-powered handheld power tool 1 implemented as an eccentric sander.

[0026] Figure 2 is a side cross-sectional view of the sander in Figure 1.

[0027] Figure 3 is a schematic diagram of an LED filament.

[0028] Figure 4 is a cross-sectional view of the LED filament as seen along line 4-4 in Figure 3.

[0029] Figure 5 is an enlarged side view of the LED filament.

[0030] Figure 6 is an example of the arrangement of traces and micro-LEDs as provided in an LED filament.

[0031] Figure 7 is a side view of a portion of the sander in Figure 1, illustrating the LED filament supported on the processing tool of the sander.

[0032] Figure 8 is a perspective view of the machining tool of Figure 7 separated from the sander, showing the groove and omitting the LED filament.

[0033] Figure 9 is a perspective view of the machining tool of Figure 7 separated from the sander, illustrating the groove and showing the LED filament disposed in the groove.

[0034] Figure 10 is a schematic cross-sectional view of a portion of the tool housing, illustrating the first morphology of the groove.

[0035] Figure 11 is a schematic cross-sectional view of a portion of the tool housing, illustrating a second morphology of the groove.

[0036] Figure 12 is a schematic cross-sectional view of a portion of the tool housing, illustrating the third form of the groove.

[0037] Figure 13 is a perspective view of the machining tool of Figure 7, showing a groove arranged downward toward the workpiece to guide light; Figure 13 includes an insert view illustrating a schematic cross-sectional view of a portion of the tool housing, showing the groove of Figure 13 at an acute angle.

[0038] Figure 14 is a schematic representation of an LED filament, showing multiple small, closely spaced micro-LEDs supported along the filament, and how illumination from the LED filament provides high-resolution shadows on an object. Figure 15 is a schematic representation of a prior art LED strip, showing relatively fewer conventional LEDs with relatively larger spacing and supported on a relatively wide substrate compared to an LED filament, and how illumination from the conventional LED strip provides fewer and coarser shadows on an object compared to an LED filament.

[0039] Figure 16 is an exemplary illustration of an LED filament used on a rotary tool 100 to emphasize the features of the tool housing.

[0040] Figure 17 is another exemplary illustration of an LED filament used on a rotary tool 100 to emphasize the features of the tool housing.

[0041] Figures 18 and 19 are exemplary illustrations of coiled LED filaments used on a rotary tool to provide emphasis and illumination. Figure 18 is an exploded view of the rotary tool and nozzle attachment. Figure 19 is a perspective view of the rotary tool of Figure 18.

[0042] Figure 20 illustrates the LED filament used on the housing of a wire saw, showing the LED filament outlining the contour of the opening in the bottom plate of the housing.

[0043] Figure 21 illustrates the LED filaments used on the housing of a wire saw, showing an LED filament that outlines the opening of the housing bottom plate, and another LED filament that wraps around a portion of the motor housing area of ​​the tool housing. Detailed Implementation

[0044] Referring to Figures 1 and 2, a handheld, battery-powered power tool 1, implemented as an eccentric sander, includes a tool housing 2. The tool housing 2 consists of at least one first housing half-shell 2A and a second housing half-shell (not shown). When assembled together, the first and second housing half-shells provide a hollow, enclosed structure that houses and supports tool drive components, which are briefly described below. The sander 1 includes an LED filament 60 supported on the outer surface of the tool housing 2. The LED filament 60 can be used to emphasize elements of the tool housing 2, such as its shape, overmolded areas, or design features. Alternatively or additionally, the LED filament 60 can be used in key locations to provide enhanced illumination. In some embodiments, this arrangement of the LED filament 60 is used to highlight the surface texture of a workpiece, allowing the user to achieve improved results compared to some previous lighting arrangements and systems. Details of the power tool 1 and the LED filament 60, along with some exemplary applications of the LED filament as the light-emitting element of the power tool 1, are provided below.

[0045] The tool housing 2 includes a motor housing region 5 and a handle region 6. A motor driver 8 is disposed in the motor housing region 5. The motor driver 8 is connected to an output shaft 10. In the illustrated embodiment, the motor driver 8 is an electronically commutated motor 12. The motor 12 and the output shaft 10 form a common first axis 14. The first axis 14 is coaxial with the output shaft 10. The output shaft 10 is connected to a carrier shaft carrying a machining tool 16 via an eccentrically positioned bearing. In the illustrated embodiment, the machining tool 16 of the battery-powered handheld power tool 1 is a backing pad, to which a grinding device such as sandpaper or abrasive blocks can be attached for machining the workpiece surface. The bearing may be a ball bearing, enabling the carrier shaft to rotate automatically about a carrier rotation axis, which also constitutes the rotation axis of the machining tool 16. The rotation axis of the carrier shaft is parallel to and eccentrically spaced from the rotation axis 14 of the output shaft 10.

[0046] Handle area 6 provides a handle 22, which is used by an operator to grip the power tool 1. The term "handle" refers to a component around which at least one of an operator's hands can be positioned for the purpose of manipulating the power tool 1. The motor housing area 5 and the handle area 6 may be arranged at an angle to each other. In the illustrated embodiment, the motor housing area 5 and the handle area 6 are at an angle of approximately 90° relative to each other.

[0047] A set of electronic components 24 is provided in the handle area 6. This set of electronic components 24 is provided to power the motor 12. Although this set of electronic components 24 is provided in the handle area 6, it is also conceivable that this set of electronic components 24 may be integrated into the motor 12 or implemented separately.

[0048] The rechargeable battery 26 serves as an energy source for the motor driver 8 and for the LED filament 60.

[0049] In the illustrated embodiment, the handle region 6 has a first gripping region 28, which defines the area around which the operator's hand rests when operating the power tool 1. For particularly convenient operation of the power tool 1, it is advantageous to provide a second gripping region 30 on the motor housing region 5. The second gripping region 30 may be shaped as a spherical handle, which also provides a pleasing visual appearance. The second gripping region 30 is designed such that it is positioned in the operator's hand in a particularly ergonomic manner.

[0050] The motor 12 directly drives the carrier shaft. The term "directly" means that the electronically commutated motor 12 is connected to the carrier shaft without the intervention of conventional transmission devices such as planetary gear drives, bevel gear drives, or spur gear drives. The eccentrically positioned machining tool 16 of the power tool 1 performs an oscillating motion. In this case, the stroke produced during the oscillating motion is twice the eccentric distance between the rotation axis of the carrier shaft and the first axis 14.

[0051] The electronically commutated motor 12 includes a stator 32 that carries a current-carrying winding 31. The stator 32 is located on the motor housing. The rotor 34, which carries a permanent magnet 35, is connected to the output shaft 10.

[0052] Since the electronic components 24 in a manual power tool 1 with an electronically commutated motor 12 are designed to be more powerful and larger in size and volume than in a brushed motor, cooling becomes increasingly important, thus requiring optimal cooling. Cooling can be implemented as passive or active cooling. In the case of passive cooling, heat is removed by convection. In the case of active cooling, heat is removed from the parts to be cooled by means of a cooling system, which in the illustrated embodiment is a fan 36. The fan 36 for cooling the motor drive 8 is integrated in the first motor housing region 5. In particular, the fan 36 is positioned between the electronically commutated motor 12 and the machining tool 16. However, it is also conceivable to use other cooling systems, such as Peltier elements, closed cooling circuits, etc. Similarly, it is conceivable to omit the fan and achieve cooling, for example, by means of strategically placed cooling fins and / or cooling bodies.

[0053] The power tool 1 includes a dust extraction device 38 attached to the tool housing 2. The machining tool 16 has drill holes distributed along its entire circumference, through which grinding dust generated during workpiece machining is drawn into the motor housing by means of a dust fan 39, which is fixedly connected to the output shaft 10. The grinding dust conveyed through the drill holes of the machining tool 16 travels via the dust extraction device 38 to a dust collection container (not shown).

[0054] A switching element is provided for starting a battery-powered handheld power tool 1. This switching element can be implemented, for example, as a bias-off switch. However, it is also conceivable that the switching element be implemented as a continuous speed control switch or a stop switch.

[0055] In an exemplary embodiment, the power tool 1 is implemented as a battery-powered handheld sander 1. As can be seen in Figures 1 and 2, a rechargeable battery 26 is connected to the rear side of the tool housing 2. A battery voltage indicator may be integrated into the handle area. A battery voltage indicator may be provided to offer a visual indication of the battery voltage level. This can be achieved using a colored LED, a flashing LED, a digital indicator element, an LCD, etc.

[0056] Referring to Figures 3 to 6, the LED filament 60 includes an elongated cylindrical body 66 having a first end 62 and a second end 64 opposite to the first end 62. The LED filament 60 includes a first electrical terminal 63 extending from the first end 62 and a second electrical terminal 65 extending from the second end 64. The body 66 is slender, for example having a diameter in the range of 1 mm to 5 mm.

[0057] The body 66 of the LED filament 60 can be made of a thin, flexible material, such as plastic or silicone. This allows the LED filament 60 to be bent and shaped to fit different lighting fixtures and designs. The materials used for the LED filament 60 are also selected for their heat resistance and ability to provide electrical insulation for the electrical components therein.

[0058] The LED filament 60 includes an array of electrically connected microLEDs 90. The microLEDs 90 used in the LED filament 60 are extremely small, typically only a few micrometers in size. The microLEDs 90 can be made of semiconductor materials known for their high efficiency and long lifespan, such as gallium nitride (GaN) or indium gallium nitride (InGaN). However, any suitable material can be used to form the microLEDs 90.

[0059] The micro-LEDs 90 are electrically connected in series along the flexible LED filament 60, thereby allowing a continuous current to power the entire length of the LED filament 60. The series connection ensures that all micro-LEDs 90 receive the same amount of current, resulting in a consistent, continuous, and uniform light output. Typically, this electrical connection is made using a thin conductive trace 82 integrated into the flexible material of the LED filament 60. In some embodiments, the trace 82 serves as a substrate, and the flexible material is coated as a coating 80 onto the trace 82. For example, the coating 80 may extend along the length of the substrate and around its circumference, such that the coating 80 is concentric with the substrate and surrounds both the substrate and the micro-LEDs 90.

[0060] One end of trace 82 corresponds to a first electrical terminal 63 extending from the first end 62, while the opposite end of trace 82 corresponds to a second electrical terminal 65 extending from the second end 64. The first and second electrical terminals 63 and 65 are electrically connected to a power supply circuit that includes a motor 12, a battery 26, control electronics 24, and one or more power switches (not shown).

[0061] The trace 82 is designed to be flexible and durable. Together with the flexible coating 80, the trace 82 allows the LED filament 60 to be bent and shaped without compromising electrical connections. For example, in some embodiments, the trace 82 is flexible enough that the LED filament 60 can be bent around each of the three orthogonal axes with a radius of 15 mm. In other embodiments, the LED filament 60 can be bent around each of the three orthogonal axes with a radius of 5 mm or less, which allows the LED filament 60 to be arranged in intricate, irregular curved shapes (Figure 3) to closely follow abrupt changes in surface shape, including bending around corners, or to be arranged in coiled stacks to multiply the illumination effect of the microLED 90.

[0062] In the LED filament 60, light is directed outward from the trace 82 in a 360-degree range in a direction perpendicular to the trace 82 (Figure 4). In the illustrated embodiment, the LED filament 60 supports at least 300 micro-LEDs per meter of filament length. In some embodiments, the body supports at least 500 micro-LEDs per meter of filament length. As used herein, the term "filament length" refers to the distance between the first end 62 and the second end 64 of the filament when the LED filament 60 is arranged in a straight line.

[0063] One advantage of this filament design is the potential for higher efficiency due to the use of more LED emitters with lower drive current. Another advantage of this design is the convenience of achieving near-complete "global" (360°) illumination from an array of miniature LEDs 90.

[0064] Referring to Figures 7 to 9, an LED filament 60 may be employed on the power tool 1 to highlight or enhance tool features and / or tool housing features and to illuminate the workpiece more effectively than some conventional power tools during tool operation. The LED filament 60 or a portion 61 thereof may be supported on a portion 40 of the tool housing 2.

[0065] In some embodiments, the portion 40 of the tool housing 2 includes a portion of the outer surface 3 of the tool housing 2 having an external shape, and the portion 61 of the LED filament 60 is arranged on the portion 40 of the tool housing 2 in such a way as to illuminate the external shape. For example, the LED filament portion 61 may follow the external shape (e.g., the LED filament may outline the contour of the external shape) to highlight the external shape.

[0066] The LED filament 60 can be secured to the tool housing, for example, using adhesives, clips, or other suitable techniques. In the illustrated embodiment, for example, the outer surface 3 of the tool housing includes a shallow groove 42 that is fitted to receive and retain a portion 61 of the LED filament 60 therein by press-fit.

[0067] In some embodiments, the groove is shaped and sized such that when a portion 61 of the LED filament 60 is disposed in the groove 42, that portion 61 protrudes relative to the outer surface 3 of the tool housing. In one example, this can be achieved by making the groove 42 have a depth less than the diameter of the LED filament 60.

[0068] In some embodiments, the groove 42 is shaped and sized such that when a portion 61 of the LED filament 60 is disposed in the groove 42, that portion 61 is recessed relative to the outer surface 3 of the tool housing. This can be achieved, for example, by making the groove 42 have a depth greater than the diameter of the LED filament 60.

[0069] Referring to Figures 10 to 13, the depth and / or geometry of the groove 42 can be fitted to direct light to desired locations, including toward a tool housing feature to be highlighted or toward a workpiece. When the groove 42 is viewed in cross-section, the groove axis 48 is defined by a line extending through a first point 51 and a second point 52, where the first point 51 is located midway between the sidewalls 44 of the groove 42, corresponding to the intersection of the groove 42 and the outer surface 3 of the tool housing, and the second point 52 is located midway between the sidewalls 44 of the groove 42, corresponding to the closed end 46 of the groove 42. In the schematic illustration of the groove 42 shown in Figure 10, the groove axis 48 is perpendicular to the outer surface 3 of the tool housing. Furthermore, the LED filament 60 is recessed relative to the outer surface 3 of the tool housing, thereby causing the light emitted from the groove 42 to be generally oriented in a direction perpendicular to the outer surface 3 of the tool housing. The arc length of the emitted light is determined in part by the width of the groove 42 at the first point 51 (e.g., the width of the groove opening).

[0070] Similarly, in the schematic illustration of the groove 42 shown in Figure 11, the groove axis 48 forms an acute angle with respect to the outer surface 3 of the tool housing, and the LED filament 60 is recessed relative to the outer surface 3 of the tool housing. However, in this example, the light emitted by the LED filament 60 is generally oriented at an acute angle with respect to the outer surface 3 of the tool housing.

[0071] In the schematic illustration of the groove 42 shown in Figure 12, the groove 42 is relatively shallow, thereby allowing the LED filament 60 to extend relative to the outer surface 3 of the tool housing. In this embodiment, the LED filament 60 emits light in an arc of approximately 180 degrees.

[0072] Referring to Figure 13, the groove 42 can be provided along the periphery of the sanding tool 16 at a position closely adjacent to the surface to which the grinding apparatus is attached. In this example, the LED filament 60 is recessed, and the groove 42 is fitted such that the groove axis 48 is oriented toward the workpiece surface. In this example, the groove 42 also protrudes from the shape of the tool 16, because the groove 42, and therefore the LED filament 60, also follows the shape into and out of the lateral recess 15 of the tool 16 and through different heights relative to the workpiece surface. This is possible because the LED filament 60 is flexible along multiple axes, allowing for illumination along complex, multi-axis bends.

[0073] Referring to Figures 14 and 15, the relatively fine profile of the LED filament 60 advantageously allows it to be placed very close to the workpiece surface (Figure 14) compared to some conventional LED light-emitting devices with larger substrates and standard-sized LEDs (Figure 15). Furthermore, the high density of the micro-LEDs 90 on the LED filament 60 generates nearly continuous light. This arrangement of the LED filament 60 guides the light approximately horizontally, resulting in shadows cast by defects 96 on the workpiece surface. Due to the high density of the micro-LEDs 90, the resolution of the shadows 94 is increased relative to some conventional LED light-emitting devices 160 with larger substrates 182 and standard-sized LEDs 190, thus providing additional detail regarding any defects on the workpiece surface.

[0074] In the embodiments illustrated in Figures 1 to 15, the battery-powered handheld power tool 1 is a sander, and the processing tool 16 of the sander 1 is a backing pad to which an abrasive device, such as sandpaper or abrasive blocks, can be attached for surface processing of a workpiece. In other embodiments, such as when the battery-powered handheld power tool 1 is a drill, saw, grinder, rotary tool, vibratory tool, etc., as discussed below, the processing tool 16 can be a spindle combined with a chuck, clamp, or other attachment device for connecting drill bits, cutting tools, grinding tools, etc., to a spindle.

[0075] Referring to Figures 16 to 21, the power tool 1 is not limited to a sander. The LED filament 60 can be used in conjunction with other types of handheld power tools, including but not limited to drills, saws, grinders, and rotary tools.

[0076] As can be seen in Figures 16 and 17, the LED filament 60 can be used with the housing 102 of the rotary sawing tools 100, 100' to highlight the details and / or stylistic features of the tool housing 102. In Figure 16, the LED filament 60 is used in the rotary tool 100 to highlight the switch and / or human-machine interface (HMI), while in Figure 17, the LED filament 60 is used in the rotary tool 100' to highlight the elongated shape of the handle 122.

[0077] As can be seen in Figures 18 and 19, another rotary tool 100” includes a first LED filament 60 (1) coiled around the circumference of the front end 110 of the rotary tool 100”. The first LED filament 60 (1) includes a first filament portion 60 (1a) coiled around the circumference of the front portion of the rotary tool 100” and thus providing overall illumination at the front portion of the rotary tool 100”, and a second filament portion 60 (1b) extending rearward along the tool handle 122 in a manner emphasizing the shape of the tool handle 122. In addition, the second LED filament 60 (2) is coiled around a nozzle attachment 112. The nozzle attachment 112 may be mechanically connected to the tool front end 110. The second LED filament 60 (2) can direct light toward the workpiece and the sawing attachment. Furthermore, by coiling the first filament portion 60 (1) and the second LED filament 60 (2), the intensity of the illumination is increased relative to the light emitted by the linear arrangement of the second LED filament 60.

[0078] Referring to Figure 20, the LED filament 60 can be used together with the saw housing 202. In the illustrated embodiment, the saw is a wire saw 200, wherein the housing 202 includes a base plate 203 that rests on the workpiece when the wire saw 200 is in use. The base plate 203 includes an opening 204 along the front edge 206 of the base plate 203, and the wire saw blade 205 extends through the opening 204 in a direction perpendicular to the workpiece surface. The opening 204 partially wraps around the blade 205, and there is a gap between the blade 205 and the opening 204. The LED filament 60 travels along the edge of the opening 204 so as to extend from the front edge 206 of the base plate and partially wrap around the saw blade 205. Because the light emitted from the LED filament 60 is close to the workpiece and propagates around the saw blade, and because the LED filament 60 emits light across a 360-degree range, the illustrated configuration minimizes or eliminates shadows on the workpiece surface. This can be compared to some conventional tool light patterns where the light source is provided at a position above the blade 205, which may cause the saw blade and tool base plate to cast shadows on the workpiece surface, making it difficult for the user to see the sawing path.

[0079] Referring to Figure 21, the power tool 1 may include a plurality of LED filaments 60. In the illustrated embodiment, the wire saw 300 includes a first LED filament 60 (1) traveling along a base plate opening 304, and a second LED filament 60 (2) traveling along a forward-facing portion of the motor housing region 303 of the tool housing 302. The first LED filament 60 (1) provides a clear view of the position of the blade 305 relative to the workpiece, while the second LED filament 60 (2) provides overall illumination of the area in front of the wire saw 300.

[0080] Although the manual power tool 1 described herein is battery powered, the power tool 1 is not limited to this type of power supply. For example, in some embodiments, the power tool 1 may be a corded or roped power tool that is configured to be manually connected to an AC power source via a plug.

[0081] Although the LED filament 60 is described herein as being fixed to the outer surface of the power tool housing 2, the LED filament is not limited to this form. In some embodiments, the LED filament 60 is fixed to the inner surface of the power tool housing 2 and is visible through a transparent or partially transparent area of ​​the tool housing 2. In other embodiments, the LED filament is disposed inside the tool housing 2 and is fixed to a structural or operational component of the tool near a transparent or partially transparent area of ​​the tool housing.

[0082] The foregoing has described selectively illustrative embodiments of a power tool including LED filament lighting in some detail. It should be understood that only structures deemed necessary for illustrating the power tool and LED filament are described herein. Other conventional structures, and the structures of accessories and auxiliary components of the power tool and LED filament, are considered to be known and understood by those skilled in the art. Furthermore, while working examples of the power tool and LED filament have been described above, the power tool and LED filament are not limited to the above-described working examples, but various design changes can be implemented without departing from the combinations set forth in the claims.

Claims

1. A power tool comprising: a tool housing; an electric motor disposed in the tool housing, the electric motor including an output shaft; a machining tool mechanically connected to the output shaft and extending from the tool housing, the machining tool being configured to transmit motion of the output shaft to an attachment of the tool; and an elongated LED filament, a portion of the LED filament being supported on a portion of the tool housing, the LED filament including a substrate and microLEDs disposed on the substrate in a spaced-apart electrical connection arrangement, such that light is emitted from the LED filament in an angular range from 0 degrees to 360 degrees in a direction perpendicular to the substrate.

2. The power tool of claim 1, wherein the substrate is sufficiently flexible that the LED filament can be bent around each of the three orthogonal axes with a radius of 5 mm.

3. The power tool of claim 1, wherein the portion of the tool housing includes a portion of the outer surface of the tool housing having an external shape, and the portion of the LED filament is arranged on the portion of the tool housing in such a way as to illuminate the external shape.

4. The power tool of claim 1, wherein the portion of the tool housing includes a portion of the outer surface of the tool housing having an external shape, and the portion of the LED filament is arranged on the portion of the tool housing in a manner that outlines the external shape.

5. The power tool of claim 1, wherein the portion of the tool housing includes a groove fitted to receive and retain the portion of the LED filament, and the portion of the LED filament is disposed in the groove.

6. The power tool of claim 5, wherein the groove is formed on the outer surface of the tool housing, and the groove is shaped and sized such that when the portion of the LED filament is disposed in the groove, the portion of the LED filament protrudes relative to the outer surface of the tool housing.

7. The power tool of claim 5, wherein the groove is formed on the outer surface of the tool housing, the groove being shaped and sized such that when the portion of the LED filament is disposed in the groove, the portion of the LED filament is recessed relative to the outer surface of the tool housing.

8. The power tool of claim 5, wherein when the groove is viewed in cross-section, the groove axis is defined by a line extending through a first point and a second point, wherein the first point is located at the midpoint between the sidewalls of the groove, corresponding to the intersection of the groove and the outer surface of the tool housing, and the second point is located at the midpoint between the sidewalls of the groove, corresponding to the closed end of the groove, and the groove axis is perpendicular to the portion of the tool housing.

9. The power tool of claim 5, wherein when the groove is viewed in cross-section, the groove axis is defined by a line extending through a first point and a second point, wherein the first point is located at the midpoint between the sidewalls of the groove, corresponding to the intersection of the groove and the outer surface of the tool housing, and the second point is located at the midpoint between the sidewalls of the groove, corresponding to the closed end of the groove, and the groove axis forms an acute angle with respect to the portion of the tool housing.

10. The power tool of claim 1, wherein the LED filament comprises an elongated cylindrical body having a first end and a second end opposite to the first end, a first electrical terminal extending from the first end, and a second electrical terminal extending from the second end, and wherein the body has a diameter in the range of 1 mm to 5 mm.

11. The power tool of claim 1, wherein the LED filament comprises an elongated body having a first end and a second end opposite to the first end, the body having a length corresponding to the distance between the first end and the second end when the body is arranged in a straight line, and the body supporting at least 300 micro LEDs per meter of body length.

12. The power tool of claim 1, wherein the LED filament comprises a flexible cylindrical substrate supporting a microLED along the length of the substrate, and wherein the substrate is covered with a coating extending along the length of the substrate and around the circumference of the substrate such that the coating is concentric with the substrate and surrounds the substrate and the microLED.

13. The power tool of claim 1, wherein the power tool is configured to be connected to a power supply, and the power supply supplies power to the motor and the LED filament.

14. The power tool of claim 1, wherein the power tool includes a structure that abuts a surface of a workpiece when the power tool is in use, the structure comprising: a contact surface that faces and abuts the workpiece when the power tool is in use, and an adjacent surface that abuts the contact surface along an edge, wherein the portion of the tool housing extends along the edge, thereby extending the portion of the LED filament along the edge.

15. The power tool of claim 1, wherein the portion of the LED filament is arranged as a coil stack.

16. The power tool of claim 1, wherein the portion of the outer surface of the tool housing surrounds the circumference of the tool housing, and the portion of the LED filament surrounds the portion of the outer surface of the tool housing at least twice.

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