Patent Application
20250178151
This application claims priority to Japanese patent application no. 2023-204829 filed on Dec. 4, 2023, the contents of which are fully incorporated herein by reference.
The present disclosure relates to a rotary tool configured to rotationally drive a tool accessory.
A rotary tool (for example, a grinder) rotationally drives a tool accessory that is removably held on a spindle. A tool accessory is fixed to a spindle, for example, by tightening a nut onto the spindle. In some cases, the nut may loosen when rotation of the spindle is suddenly stopped. To address this problem, Japanese Unexamined Patent Application Publication No. 2012-200794 discloses a grinder with an anti-loosening member. The anti-loosening member is configured such that, when the rotation of the spindle is suddenly stopped, the anti-loosening member moves toward the tool accessory by an action of an inclined surface (cam surface) provided on each of a flange portion of the spindle and the anti-loosening member.
In the grinder described above, the flange portion of the spindle is fitted into a fitting recess provided in the anti-loosening member with play. The lower surface of the flange portion of the spindle forms the inclined surface, which abuts the inclined surface on the bottom surface of the fitting recess. In such a configuration, the anti-loosening member may not sufficiently move on the inclined surface due to the accumulation of dust in the fitting recess, thereby failing to ensure sufficient anti-loosening effects.
In view of the circumstances described above, it is one non-limiting object of the present disclosure to provide an improvement with regard to an anti-loosening structure in a rotary tool.
According to one non-limiting aspect of the present disclosure, a rotary tool including a spindle, an internally threaded member, and an anti-loosening member is provided. The spindle is configured to be rotationally driven in a first direction around a drive axis that defines the up-down direction of the rotary tool. The spindle has a lower end portion formed as an externally threaded portion and a flange portion protruding radially outward from the spindle above the externally threaded portion. The internally threaded member is removably screwed onto the externally threaded portion. The anti-loosening member has an annular shape, and is fitted around the spindle above the externally threaded portion. The anti-loosening member is configured to (i) rotate integrally with the spindle when the spindle rotates in the first direction and (ii) restrict loosening of the internally threaded member by displacing downward while rotating in the first direction with respect to the spindle in response to the stopping of the rotation of the spindle.
The lower surface of the flange portion of the spindle includes a first inclined surface. The first inclined surface extends in the circumferential direction around the drive axis and is inclined downward toward the first direction. The anti-loosening member includes a base portion and peripheral wall portions. The base portion is annular and is located below the flange portion. The base portion has a second inclined surface that slidably contacts the first inclined surface of the flange portion. The peripheral wall portions protrude upward along the outer edge portion of the base portion. Each peripheral wall portion is configured to abut the side surface of the flange portion during the rotation of the spindle to receive the rotational driving force. The peripheral wall portion are provided only in a part of the outer edge portion of the base portion.
In the rotary tool of the present aspect, when the spindle that has been rotating in the first direction stops rotating, the anti-loosening member moves downward while rotating in the first direction with respect to the spindle by the action of the first inclined surface of the flange portion of the spindle and the second inclined surface of the anti-loosening member. This exerts, to the internally threaded member, a force of pressing the internally threaded member downward, thereby restricting loosening of the internally threaded member.
Further, the anti-loosening member includes the peripheral wall portion protruding upward from the base portion to receive the transmission of the rotational driving force from the spindle. However, the peripheral wall portion are provided only partially, rather than entirely, on the circumference of the outer edge portion of the base portion. That is, an opening (a gap or a space), which is a region not occupied by the peripheral wall portion, is present radially outward of the flange portion. Therefore, in comparison with the configuration in which the peripheral wall portion is provided entirely on the circumference of the outer edge portion of the base portion, dust is less likely to accumulate in a region (space) radially inward of the peripheral wall portion. Further, even if dust enters into this region, the dust can be effectively discharged by centrifugal force through the opening (gap) when the anti-loosening member rotates integrally with the spindle. This reduces the possibility that dust enters between the first inclined surface and the second inclined surface, thus hindering the displacement of the anti-loosening member, thereby reducing its effects of the anti-loosening.
In one non-limiting embodiment of the present disclosure, a base portion may have a passage extending from a radially inward end to a radially outward end of the base portion below the flange portion. According to this embodiment, even when dust enters into a radially inward region of the peripheral wall portion, the dust can be discharged not only from the opening that is radially outward of the flange portion, but also from the passage below the flange portion.
In addition to or instead of the above-described embodiment, the passage may be adjacent to an end of the second inclined surface, the end being opposite to the first direction in the circumferential direction. The second inclined surface is inclined downward toward the first direction, corresponding to the first inclined surface. Therefore, the end of the second inclined surface opposite to the first direction is at the uppermost position of the second inclined surface in the up-down direction. Therefore, by providing a passage adjacent to the end, the dimension of the passage in the up-down direction can be maximized.
In addition to or instead of the above-described embodiment, the upper end of the peripheral wall portion of the anti-loosening member may be at a lower position than an upper end of the flange portion of the spindle in the up-down direction. Furthermore, the upper end of the anti-loosening member may be at a position the same as or below the center of the flange portion in the up-down direction. According to these embodiments, it is possible to achieve the anti-loosening member even more resistant to dust accumulation.
In addition to or instead of the above-described embodiment, the peripheral wall portion may include a rotation transmission portion and an extension portion. The rotation transmission portion may have a rotation transmission surface configured to receive the rotational driving force from the spindle. The extension portion may extend in the second direction from an end on the second direction side, which is opposite to the first direction, of the rotation transmission portion, while being radially outward from the flange portion. According to this embodiment, the extension portion reduces the possibility of dust entering between the rotation transmission surface and the side surface of the flange portion from a region radially outward of the flange portion.
In addition to or instead of the above-described embodiment, the peripheral wall portion may further include a stopper portion. The stopper portion may have a stopper surface configured to abut the side surface of the flange portion to restrict the rotation of the anti-loosening member when the anti-loosening member rotates in the first direction with respect to the spindle. The extension portion may extend along an outer edge portion of the base portion at least from a virtual first plane containing the rotation transmission surface to a virtual second plane containing the stopper surface. The flange portion is capable of rotating between a position where the side surface of the flange portion abuts the rotation transmission surface and a position where the side surface abuts the stopper surface. Thus, a region between the first plane and the second plane corresponds to a gap that may be generated between the side surface of the flange portion and the rotation transmission surface. According to this embodiment, since the extension portion corresponds to the entire gap, it is possible to more effectively restrict dust from entering.
In addition to or instead of the above-described embodiment, the rotary tool may further include an annular member removably provided around the spindle between the anti-loosening member and the externally threaded portion. The annular member may be configured to engage with the anti-loosening member and rotate integrally with the anti-loosening member. A recess configured to engage with the annular member may be formed in a lower portion of the rotation transmission portion in the base portion. The extension portion may extend in the second direction beyond an end on a second direction side of the recess. According to this embodiment, since the recess is provided utilizing the portion where the height of the rotation transmission portion is added to the base portion in the up-down direction, it is possible to provide the recess necessary for the engagement with the annular member while suppressing the height of the anti-loosening member in the up-down direction. Further, providing the extension portion also ensures sufficient strength by avoiding thinning of the portion where the recess is formed, while suppressing the height of the entire anti-loosening member in the up-down direction.
In addition to or instead of the above-described embodiment, the rotary tool may further include an annular elastic body attached to an annular groove formed on the outer peripheral surface of the spindle. The anti-loosening member may be held by the elastic body such that the anti-loosening member is (i) rotatable around the drive axis with respect to the spindle and (ii) movable in the up-down direction with respect to the spindle due to elastic deformation of the elastic body. According to this embodiment, rational retention structure for the anti-loosening member can be achieved with less space utilizing the elastic body with a simple structure.
The following specifically describes a representative and non-limiting embodiment of the present disclosure with reference to the drawings. In the following embodiment, a hand-held electrically-driven disk grinder 1 (hereinafter simply referred to as “grinder 1”) is described as an example of a rotary tool according to the present disclosure.
First, a general structure of the grinder 1 is described. As shown in
One end portion of the spindle 3 in an axial direction of the spindle 3 is exposed outward from the housing 10. A tool accessory 91 is removably attached to the one end portion of the spindle 3. For example, a grinding stone, a cutting stone, a blade, a brush, and the like are available as the tool accessories 91 that can be attached to the grinder 1. The user selects an appropriate tool accessory 91 according to a desired machining (processing) operation and attaches the selected tool accessory 91 to the grinder 1. When the spindle 3 is driven by the motor 21 to rotate around the drive axis DX, the tool accessory 91 is rotated to perform a machining operation with respect to a workpiece. The grinder 1 is capable of performing a machining operation, such as grinding, polishing, and cutting, with respect to a workpiece, depending on the type of the tool accessory 91. The tool accessory 91 is partially covered by a wheel cover 92 attached to the housing 10.
The detailed configuration of the grinder 1 is described below. For convenience of description, the direction in which the drive axis DX extends is hereinafter defined as an “up-down direction” of the grinder 1. In the up-down direction, one end side of the spindle 3 to which the tool accessory 91 is attached is defined as the lower side of the grinder 1, and the opposite side is defined as the upper side of the grinder 1. The direction in which the rotation axis RX of the output shaft 215 extends is defined as a “front-rear direction” of the grinder 1. In the front-rear direction, the side on which the spindle 3 is disposed is defined as the front side of the grinder 1, and the opposite side is defined as the rear side of the grinder 1. A direction orthogonal to both the up-down direction and the front-rear direction is defined as a “left-right direction” of the grinder 1. Further, any direction orthogonal to the drive axis DX is defined as the radial direction of the spindle 3. In the radial direction, a direction to be away from the drive axis DX is defined as a radially outward direction, and a direction approaching the drive axis DX is defined as a radially inward direction.
As shown in
The motor housing 11 is an elongated cylindrical housing that extends in the front-rear direction. The motor housing 11 is also configured to function as a grip portion to be held by the user. The motor housing 11 houses the motor 21 and a switch 22. The output shaft 215 of the motor 21 extends in the front-rear direction. The front and rear end portions of the output shaft 215 are respectively supported by bearings. The switch 22 is located behind the motor 21. The switch 22 is operably connected to a switch knob (not shown). The switch knob is located outside the motor housing 11 and is moved between an OFF position and an ON position in response to manual operation by the user. The switch 22 is turned on and off according to the movement of the switch knob. The motor 21 is driven while the switch 22 is ON.
In the present embodiment, the grinder 1 operates on electric power supplied from an external AC power source via a power cord 29 extending from the rear end portion of the motor housing 11. However, the grinder 1 may be configured to operate on electric power supplied from a removably-mounted rechargeable battery.
Further, as shown in
The brake member 253 is configured to move in response to the movement of the switch knob. More specifically, the brake member 253 is strongly pressed against the brake plate 251 by the biasing force of the biasing spring 255 while the switch knob is at the OFF position. When the user moves the switch knob to the ON position, the brake member 253 moves forward to be away from the brake plate 251 against the biasing force of the biasing spring 255, thus permitting rotation of the output shaft 215 of the motor 21. When the user moves the switch knob to the OFF position, the driving of the motor 21 is stopped. Also, the brake member 253 is strongly pressed against the brake plate 251 by the biasing force of the biasing spring 255, thereby braking the output shaft 215 and the spindle 3 through the brake plate 251.
As shown in
With this configuration, the rotation of the output shaft 215 is transmitted to the spindle 3 as the motor 21 is driven, thereby rotationally driving the spindle 3. Since the grinder 1 is a rotary tool that rotationally drives the tool accessory 91 in only one direction, the spindle 3 is rotationally driven in only one predetermined direction around the drive axis DX. Specifically, the rotation direction RD of the spindle 3 (see
The lower end portion of the spindle 3 protrudes downward through an opening provided in the lower end of the gear housing 15, and is exposed to the outside of the housing 10. The lower end portion of the spindle 3 is configured as an externally threaded portion 31. The externally threaded portion 31 is a portion with an outer peripheral surface on which a thread is formed, and occupies a predetermined range from the lower end of the spindle 3. A lock nut 55 is removably screwed onto the externally threaded portion 31 to fix the tool accessory 91 to the spindle 3.
As shown in
Each of the two protruding portions 331 of the flange portion 33 has side surfaces 333 that are substantially parallel to each other, and an arc-shaped end surface. Each side surface 333 is substantially parallel to a plane that contains the drive axis DX. Further, each protruding portion 331 has a lower surface including a first inclined surface 336. The first inclined surface 336 extends in a circular arc along the circumferential direction around the drive axis DX. The first inclined surface 336 is inclined at a predetermined angle with respect to a plane orthogonal to the drive axis DX. More specifically, the first inclined surface 336 is inclined downward toward the rotation direction RD of the spindle 3. The angle between the plane orthogonal to the drive axis DX and the first inclined surface 336 (hereinafter simply referred to as the inclination angle of the first inclined surface 336) is greater than the lead angle of the thread of the externally threaded portion 31.
As shown in
The anti-loosening member 4 is an annular (short cylindrical) member as a whole. The anti-loosening member 4 is disposed around the spindle 3 between the flange portion 33 and the externally threaded portion 31 (inner flange 51) in the up-down direction. The anti-loosening member 4 is configured to rotate integrally with the spindle 3 during the rotational driving of the spindle 3 by the rotational driving force transmitted from the flange portion 33. The anti-loosening member 4 is further configured to cooperate with the flange portion 33, so as to restrict or prevent the lock nut 55 from loosening when the rotation of the spindle 3 is stopped.
More specifically, as shown in
The two peripheral wall portions 45 are diametrically opposite opposed to each other on the base portion 41. With this configuration, two openings (gaps, spaces) 401 are provided between the two peripheral wall portions 45 in the circumferential direction of the anti-loosening member 4. In other words, the two peripheral wall portions 45 and the two openings 401 are alternately disposed along the outer edge portion of the base portion 41. Further, the two peripheral wall portions 45 are point symmetrical in plan view, with respect to the drive axis DX at the center. In a region (space) 450 between the two peripheral wall portions 45 that are diametrically opposite to each other, the flange portion 33 of the spindle 3 is disposed with play in the circumferential direction (see
Each of the peripheral wall portions 45 includes a rotation transmission portion 452, a stopper portion 454, and an extension portion 456.
The rotation transmission portion 452 has a rotation transmission surface 451. The rotation transmission surface 451 is a portion of an inner side surface of each peripheral wall portion 45 and is configured to abut the side surface 333 of the flange portion 33 (protruding portion 331) when the spindle 3 is rotationally driven in the rotation direction RD and receive transmission of rotational power from the spindle 3 (see the solid line in
The stopper portion 454 has a stopper surface 453. The stopper surface 453 is another portion of the inner side surface of each peripheral wall portion 45 and is configured to abut the side surface 333 of the flange portion 33 (protruding portion 331) when the anti-loosening member 4 rotates in the rotation direction RD relative to the spindle 3, thereby restricting the rotation of the anti-loosening member 4 (see the double-dotted line in
The extension portion 456 is a portion connected to the other end of the rotation transmission portion 452 on the side opposite to the rotation direction RD. The extension portion 456 extends along the outer edge of the base portion 41 radially outside of the flange portion 33. The extension portion 456 extends from a virtual first plane P1 containing the rotation transmission surface 451 to slightly beyond a virtual second plane P2 containing the stopper surface 453. As described above, the flange portion 33 is allowed to rotate between the position where the side surface 333 abuts the rotation transmission surface 451 (the position shown by the solid line in
Each peripheral wall portion 45 is configured such that the upper end of the peripheral wall portion 45 is at a lower position than the upper end of the flange portion 33 of the spindle 3 in the up-down direction. More specifically, the upper end of the peripheral wall portion 45 is generally at the center of the flange portion 33 or at a lower position than the center in the up-down direction. Therefore, a generally upper half of the flange portion 33 protrudes above the peripheral wall portion 45 (see
The base portion 41 has two wedge-shaped protrusions 411. The two protrusions 411 are positioned to be respectively opposite to the lower surfaces of the two protruding portions 331 of the flange portion 33 disposed in the region 450. Each of the two protrusions 411 extends in a circular arc in the circumferential direction of the base portion 41. Each of the two protrusions 411 has an upper surface formed as a second inclined surface 412 that is inclined downward toward the rotation direction RD of the spindle 3 at substantially the same angle as the first inclined surface 336. Therefore, the second inclined surface 412 slidably contacts the first inclined surface 336 of the corresponding protruding portion 331 with the flange portion 33 disposed in the region 450.
An end 413 of the second inclined surface 412 (the protrusion 411) on the opposite side of the rotation direction RD (i.e., an end at which the height of the protrusion 411 in the up-down direction is maximum) and an end 457 of the adjacent peripheral wall portion 45 on the rotation direction RD side are spaced apart from each other in the circumferential direction. In other words, there is a gap between the end 413 of the second inclined surface 412 (the protrusion 411) and the end 457 of the peripheral wall portion 45. This gap serves as a passage 403 extending from a radially inward edge to a radially outward edge of the base portion 41 below the flange portion 33 disposed in the region 450.
As shown in
With such a retention structure, the anti-loosening member 4 is rotatable around the drive axis DX with respect to the spindle 3. The anti-loosening member 4 is also movable in the up-down direction with respect to the spindle 3 in response to the elastic deformation of the O-ring 47. Thus, in the present embodiment, a space-saving and rational retention structure for the anti-loosening member 4 is achieved utilizing the O-ring 47 with a simple structure.
As shown in
The inner flange 51 has an insertion hole 510 through which the spindle 3 is inserted and an engagement groove 511 that is engageable with the base portion 41 of the anti-loosening member 4. The engagement groove 511 is provided at an upper part of the inner flange 51 and linearly extends along the diameter of the inner flange 51. The pair of side surfaces of the engagement groove 511 are parallel to each other, and, in a state where the inner flange 51 is fitted around the spindle 3, the side surfaces are substantially parallel to a plane containing the drive axis DX. Further, on the lower side of the inner flange 51, a cylindrical portion 515 protrudes downward to surround the insertion hole 510. The cylindrical portion 515 is configured to fit into the insertion hole 910 of the tool accessory 91.
As shown in
In the present embodiment, the two recesses 458 are disposed below the peripheral wall portions 45, corresponding to the two peripheral wall portions 45. More specifically, as shown in
As described above, in the present embodiment, the recess 458 is provided utilizing the portion where the heights of the rotation transmission portion 452 and the stopper portion 454 are added to the base portion 41 in the up-down direction. This allows the provision of the recess 458 that is necessary for the engagement with the inner flange 51 while suppressing the height of the anti-loosening member 4 in the up-down direction. Further, providing the extension portion 456 also ensures sufficient strength by avoiding thinning of the portion where the recess 458 is formed, while suppressing the height of the entire anti-loosening member 4 in the up-down direction.
As shown in
The operation of the grinder 1 is described below.
The user first attaches an appropriate tool accessory 91 to the grinder 1 according to the desired machining work. If the tool accessory 91 is a disk-shaped tool accessory 91, the user first fits the inner flange 51 around the spindle 3 from below the spindle 3 so that the engagement groove 511 engages with the lower part of the anti-loosening member 4. The user then places the tool accessory 91 around the spindle 3, and moves it upward to fit the cylindrical portion 515 of the inner flange 51 into an upper part of the insertion hole 910. The user further tightens the lock nut 55 onto the externally threaded portion 31 with the upper part of the cylindrical portion 555 of the lock nut 55 fitting into the lower part of the insertion hole 910 of the tool accessory 91. This allows the tool accessory 91 to be clamped by the inner flange 51 and the lock nut 55 and thereby fixed to the spindle 3.
The lock nut 55 is rotated in the opposite direction of the rotation direction RD to be tightened onto the externally threaded portion 31. Therefore, due to the friction, the inner flange 51 and the anti-loosening member 4 also rotate in the opposite direction of the rotation direction RD with respect to the spindle 3. The anti-loosening member 4 is held in a position (shown in solid line in
When the user manually operates the switch knob and moves it to the ON position, the motor 21 is driven and the spindle 3 and the tool accessory 91 fixed to the spindle 3 are rotationally driven in the rotation direction RD. As mentioned above, since the tightening direction of the lock nut 55 is opposite to the rotation direction RD, the lock nut 55 will not loosen from the screwed state while the spindle 3 is rotationally driven.
When the user manually operates the switch knob and moves it to the OFF position, the driving of the motor 21 is stopped and the brake device 25 is activated as described above. Although the output shaft 215 and the spindle 3 quickly stop their rotation, the tool accessory 91 would continuously rotate in the rotation direction RD due to inertia. As well as the tool accessory 91, due to friction, the lock nut 55, the inner flange 51, and the anti-loosening member 4 would continuously rotate in the rotation direction RD, i.e., in the direction in which the lock nut 55 loosens from the screwed state, with respect to the spindle 3.
As the anti-loosening member 4 rotates in the rotation direction RD with respect to the spindle 3, the anti-loosening member 4 is simultaneously moved downward while elastically deforming the O-ring 47 by the action of the first inclined surface 336 of the flange portion 33 and the second inclined surface 412 of the base portion 41 that slide against each other. The anti-loosening member 4 presses the lock nut 55 downward through the inner flange 51 and the tool accessory 91 due to the wedge effect of the first inclined surface 336 and the second inclined surface 412. This restricts the lock nut 55 from loosening. Further, as described above, the inclination angles of the first inclined surface 336 and the second inclined surface 412 are set larger than the lead angle of the thread of the externally threaded portion 31. This reliably prevents the lock nut 55 from loosening.
Although detailed illustrations are omitted, some of the tool accessories 91 for use in the grinder 1 can be attached to the spindle 3 without using the inner flange 51 and the lock nut 55.
Such a tool accessory 91 has an internally threaded portion and is mounted by screwing the internally threaded portion onto the externally threaded portion 31 of the spindle 3. The anti-loosening member 4 of the present embodiment has the same effect on the loosening of such a tool accessory 91 with an internally threaded portion as its effect on the lock nut 55.
As explained above, the grinder 1 of the present embodiment includes the anti-loosening member 4 that restricts loosening of the lock nut 55 or the tool accessory 91 having an internally threaded portion when the spindle 3 stops its rotation. The anti-loosening member 4 includes the base portion 41 having the second inclined surface 412 that slidably contacts with the first inclined surface 336 of the flange portion 33 of the spindle 3, and the peripheral wall portions 45 that receive rotational driving force from the flange portion 33 when the spindle 3 is rotationally driven.
The peripheral wall portions 45 are provided only partially, rather than entirely, on the circumference of the outer edge portion of the base portion 41, and there are openings (gaps) 401 on a portion radially outward from the flange portion 33. Therefore, in comparison with the configuration in which the peripheral wall portions 45 are provided entirely on the circumference of the outer edge portion of the base portion 41, dust is less likely to accumulate in the region 450 of the peripheral wall portions 45. Further, even if dust enters the region 450, the dust can be effectively discharged by centrifugal force through the openings 401 when the anti-loosening member 4 rotates integrally with the spindle 3. This reduces the possibility that dust enters between the first inclined surface 336 and the second inclined surface 412, thus hindering the displacement of the anti-loosening member 4, thereby reducing its effects of the loosening restriction.
Further, in the present embodiment, the upper end of each peripheral wall portion 45 of the anti-loosening member 4 is positioned approximately at the center in the up-down direction of the flange portion 33 or below the center. This allows the anti-loosening member 4 to have a structure even more resistant to dust accumulation.
Further, each peripheral wall portion 45 also includes an extension portion 456 that extends from the rotation transmission portion 452 in the opposite direction of the rotation direction RD. Therefore, it is possible to reduce the possibility of dust entering between the rotation transmission surface 451 and the side surface 333 of the flange portion 33 from the radially outward direction from the flange portion 33. In particular, in the present embodiment, the extension portion 456 corresponds to the entire part of the gap (the region between the first plane P1 and the second plane P2) that may be formed between the side surface 333 and the rotation transmission surface 451, thereby effectively restricting dust from entering.
Furthermore, in the present embodiment, the base portion 41 has a passage 403 that extends from the radially inward end to the radially outward end of the base portion 41 below the flange portion 33. Therefore, even if dust enters below the flange portion 33 in the region 450, the dust can be effectively discharged through the passage 403. In particular, the passage 403 is provided adjacent to the end 413 of the second inclined surface 412, the end being on the opposite side of the rotation direction RD of the spindle 3. Since the second inclined surface 412 is inclined downward toward the rotation direction, the end 413 of the second inclined surface 412 is at the uppermost position of the second inclined surfaces 412 in the up-down direction. Therefore, by providing the passage 403 adjacent to the end 413, the size of the passage 403 in the up-down direction can be maximized. This increases the dust discharge effect.
The correspondences between each component (feature) of the above-described embodiment and each component (feature) of the present disclosure or the present invention are as follows. However, the components of the above-described embodiment are merely exemplary and do not limit the components of the present disclosure or the present invention.
The grinder 1 is an example of a “rotary tool.” The spindle 3 is an example of a “spindle.” The rotation direction RD is an example of a “first direction.” The externally threaded portion 31 is an example of an “externally threaded portion.” The flange portion 33 is an example of a “flange portion.” Each of the lock nut 55 and the tool accessory 91 having an internally threaded portion is an example of an “internally threaded member.” The anti-loosening member 4 is an example of an “anti-loosening member.” The first inclined surface 336 is an example of a “first inclined surface.” The base portion 41 is an example of a “base portion.” The second inclined surface 412 is an example of a “second inclined surface.” The peripheral wall portion 45 is an example of a “peripheral wall portion.” The passage 403 is an example of a “passage.” The end 413 is an example of an “end of the second inclined surface opposite to the first direction in the circumferential direction.” The rotation transmission portion 452 and the rotation transmission surface 451 are examples of a “rotation transmission portion” and a “rotation transmission surface,” respectively. The extension portion 46 is an example of an “extension portion.” The stopper portion 454 and the stopper surface 453 are examples of a “stopper portion” and a “stopper surface,” respectively. The first plane P1 and the second plane P2 are examples of a “first plane” and a “second plane,” respectively. The inner flange 51 is an example of an “annular member.” The recess 458 is an example of a “recess.” The groove 35 is an example of an “annular groove.” The O-ring 47 is an example of an “annular elastic body.”
The above-described embodiment is merely an example, and the power tool according to the present disclosure is not limited to the grinder 1 thus exemplified. For example, the following exemplary modifications are possible. Further, at least one of these modifications may be employed in combination with at least one of the grinder 1 exemplified in the embodiment and the claimed features.
For example, the rotary tool according to the present disclosure is not limited to so-called angle grinders such as the grinder 1. Non-limiting examples of the rotary tool according to the present disclosure include straight grinders, sanders, and polishers. If the rotary tool includes a brake device for the motor or spindle, the anti-loosening structure according to the present disclosure is particularly useful. The brake device is not limited to the friction brake device 25 of the above-described embodiment, but may be a mechanically engaged brake device or an electric brake that electrically brakes the motor 21.
The flange portion of the spindle, the anti-loosening member, and the internally threaded member according to the present disclosure are not limited to the flange portion 33, the anti-loosening member 4, and the lock nut 55 of the above-described embodiment, and their configurations (e.g., shape, size, and manner of engagement/connection with other members) may be changed as appropriate. For example, the number of the protruding portions 331 (the first inclined surfaces 336) of the flange portion 33 and the corresponding protrusions 411 (the second inclined surfaces 412) of the base portion 41 may be one, three or more. Similarly, the number of the protruding portions 331 (the side surfaces 333) of the flange portion 33 and corresponding peripheral wall portions 45 (the rotation transmission portions 452, the stopper portions 454, and the extension portions 456) may be one, three or more.
In view of the nature of the present invention and the above-described embodiment, the following aspects are provided. At least one of the following aspects can be employed in combination with at least one of the features of the above-described embodiments and modification examples, as well as the claimed features.
[Aspect 1] The rotary tool further includes:
The inner flange 51 is an example of an “annular member” of the present aspect.
[Aspect 2] The internally threaded member is a tool accessory having an internally threaded portion that is configured to be screwed onto the externally threaded portion.
1: electrically-driven disk grinder (grinder), 10: housing, 11: motor housing, 15: gear housing, 21: motor, 215: output shaft, 216: driving bevel gear, 22: switch, 25: brake device, 251: brake plate, 253: brake member, 255: biasing spring, 29: power cord, 3: spindle, 31: externally threaded portion, 33: flange portion, 331: protruding portion, 333: side surface, 336: first inclined surface, 35: groove, 38: driven bevel gear, 4: anti-loosening member, 401: gap, 403: passage, 41: base portion, 410: insertion hole, 411: protrusion, 412: second inclined surface, 413: end, 415: recess, 45: peripheral wall portion, 450: region, 451: rotation transmission surface, 452: rotation transmission portion, 453: stopper surface, 454: stopper portion, 456: extension portion, 457: end, 458: recess, 459: side surface, 47: O-ring, 51: inner flange, 510: insertion hole, 511: engagement groove, 515: cylindrical portion, 55: lock nut, 550: thread hole, 555: cylindrical portion, 91: tool accessory, 910: insertion hole, 92: wheel cover, DX: drive axis, RX: rotation axis, RD: spindle rotation direction, P1: first plane, P2: second plane
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-204829 | Dec 2023 | JP | national |
