Power tool

Abstract

The electric tool comprises a housing, a motor accommodated in the housing, a working head connected to the motor, and a shroud partially accommodating the working head, the shroud being circumferentially rotatable and arranged on the housing, the electric tool further comprises a switching assembly arranged on the housing, the switching assembly comprising a guide rod fixed on the housing, a clamping block movably arranged on the guide rod, and an elastic member connected to the clamping block, the shroud comprises a coupling portion capable of being clamped with the clamping block, the clamping block has a locking position for clamping with the coupling portion, an unlocking position for being disengaged from the coupling portion, and a movement path from the locking position to the unlocking position, the movement path comprises a horizontal displacement for accumulating the elastic recovery force of the elastic member and a vertical displacement for being disengaged from the coupling portion. The electric tool of the present application utilizes the switching assembly to achieve the one-way rotation of the shroud to unlock the shroud.

Description

[Technical Field]

[0001] This invention relates to the field of power tools, and particularly to a handheld power tool. [Background Technology]

[0002] The safe operation of power tools is receiving increasing attention, and related safety regulations are becoming more comprehensive. Power tools, such as angle grinders or sanders, often produce flying debris and sparks during operation, necessitating the installation of guards to separate the workspace, including the working head, from the operator. Guards are generally fan-shaped and fixed to the power tool; some guards are rotatable to allow the operator to adjust the angle, making the power tool more suitable for different working directions or objects.

[0003] For safety reasons, the guard needs to be unlocked before it can be rotated. However, the existing unlocking mechanisms for power tools are poorly designed and cannot easily and efficiently unlock the guard in one direction. Accidental reverse rotation of the guard negatively impacts the safety of using the power tool, and the inefficient and cumbersome unlocking mechanisms also hinder safer use.

[0004] Therefore, it is indeed necessary to provide an improved power tool to overcome the shortcomings of the prior art. [Summary of the Invention]

[0005] To address the aforementioned problems, this invention provides a simple and efficient electric tool for unlocking a protective cover by unidirectional rotation.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] An electric tool includes a housing, a motor housed within the housing, a working head coupled to the motor, and a protective cover partially housing the working head. The protective cover is rotatably disposed on the housing. The electric tool further includes a switching assembly disposed on the housing. The switching assembly includes a guide rod fixed to the housing, a locking block movably disposed on the guide rod, and an elastic element connected to the locking block. The protective cover includes a coupling portion that can engage with the locking block. The locking block has a locked position for engaging with the coupling portion, an unlocked position for disengaging from the coupling portion, and a movement path from the locked position to the unlocked position. The movement path includes a horizontal displacement that accumulates the elastic restoring force of the elastic element and a vertical displacement that disengages from the coupling portion.

[0008] A further improvement is as follows: the coupling part includes a plurality of protruding ribs spaced apart along the rotation direction of the protective cover, and the locking block includes a protrusion that can be vertically inserted between two adjacent protruding ribs to engage the locking block with the coupling part.

[0009] A further improvement is as follows: the front and rear sides of the protrusion along the horizontal displacement direction are respectively a first side and a second side, at least part of the first side is an inclined surface, and the second side is a plane.

[0010] A further improvement is that the guide rod is provided with a groove or a through hole, and the locking block is slidably connected to the guide rod through the groove or through hole.

[0011] A further improvement is as follows: the locking block and the guide rod are connected by a fixing pin, wherein the guide rod is provided with an oblong hole, the locking block is provided with a connecting hole corresponding to the oblong hole, the fixing pin passes through the oblong hole and the connecting hole, and the fixing pin can move back and forth along the oblong hole.

[0012] A further improvement is that the card block is in the locked position when it slides to one end of the groove or through hole, and in the unlocked position when it slides to the opposite end.

[0013] A further improvement is that the axis of the guide rod is not parallel to any tangent line that is tangent to the circumferential rotation direction of the protective cover.

[0014] A further improvement is that the switching component further includes a pair of support blocks fixed to the housing at intervals, and the two ends of the guide rod are respectively fixed to the pair of support blocks.

[0015] A further improvement is as follows: the elastic element is a compression spring, and the two ends of the compression spring abut against the locking block and the support block, respectively.

[0016] A further improvement is proposed: the elastic element is a tension spring, and both ends of the tension spring are fixed to the locking block and the support block, respectively.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The power tool further includes a switching assembly disposed on the housing. The switching assembly includes a guide rod fixed to the housing, a locking block movably disposed on the guide rod, and an elastic element connected to the locking block. The protective cover includes a coupling part that can engage with the locking block. The locking block has a locked position that maintains engagement with the coupling part, an unlocked position that disengages from the coupling part, and a movement path from the locked position to the unlocked position. The movement path includes a horizontal displacement that accumulates the elastic restoring force of the elastic element and a vertical displacement that disengages from the coupling part. The power tool utilizes the switching assembly to achieve unidirectional rotation of the protective cover to unlock it. The switching assembly has a simple structure and ingenious design. Through the locking block, which has a movement path that can be decomposed into displacements in different directions, it simultaneously unlocks the protective cover to the unlocked state and accumulates the elastic restoring force for resetting to the locked state. After releasing the external force applied to the protective cover, the protective cover naturally locks, achieving unidirectional unlocking of the protective cover simply and efficiently. [Image Description]

[0018] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0019] Figure 1 This is a cross-sectional view of the power tool of the present invention;

[0020] Figure 2 This is a partial exploded view of the power tool of the present invention;

[0021] Figure 3 This is an assembly diagram of the power tool switching assembly of the present invention;

[0022] Figure 4 This is a partial schematic diagram of the power tool of the present invention with the locking block in the locked position after the compression spring is used;

[0023] Figure 5 This is a partial schematic diagram of the power tool of the present invention with the locking block in the unlocked position after the compression spring is used;

[0024] Figure 6 This is a partial schematic diagram of the power tool of the present invention with the spring-loaded locking block in the locked position;

[0025] Figure 7 This is a partial schematic diagram of the power tool of the present invention with the spring-loaded locking block in the unlocked position.

[0026] Meaning of the reference numerals in the diagram:

[0027] 100, Housing; 200, Motor; 300, Working Head; 400, Protective Cover; 410, Coupling Part; 411, Protruding Rib; 500, Switching Assembly; 510, Guide Rod; 511, Waist-shaped Hole; 520, Locking Block; 521, Protrusion; 522, First Side Surface; 523, Second Side Surface; 524, Connecting Hole; 530, Elastic Member; 540, Fixing Pin; 550, Support Block [Detailed Implementation]

[0028] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as "upper," "lower," "front," and "rear" that indicate orientation or positional relationship are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device / element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0029] Please see Figures 1 to 5The power tool shown in this invention, such as an angle grinder, includes a housing 100, a drive assembly 1, a transmission assembly 2, a working assembly 3, and a control assembly 4. The drive assembly 1 includes a motor 200 and an output shaft driven by the motor 200, the output shaft being connected to the transmission assembly 2. The working assembly 3 is connected to the other side of the transmission assembly 2 relative to the output shaft. The working assembly 3 includes working heads 300 such as grinding wheels and wire wheels. The motor 200 drives the working assembly 3 through the transmission assembly 2 to act on the surface to be worked or the workpiece to be processed, thus realizing the operation of the power tool. The control assembly 4 includes chips and circuits, used to control the operation of the drive assembly 4. The drive assembly 4, transmission assembly 2, and control assembly 4 are disposed within the housing 100 and are constrained and protected by the housing 100.

[0030] The housing 100 includes a main housing and a head housing connected to the main housing. A motor 200 is housed within the main housing, and a working head 300 and a protective cover 400 are located within the head housing. The working head 300 is coupled to and driven by the motor 200. The protective cover 400 at least partially houses the working head 300, ensuring that the working head 300 does not obstruct the operator when in operation. The protective cover 400 is fan-shaped or semi-circular, and can rotate circumferentially to allow the operator to adjust its angle.

[0031] The power tool in this embodiment also includes a switching assembly 500 for switching the locked and unlocked states of the guard 400. The assembly includes a guide rod 510, a locking block 520, and an elastic element 530. The switching assembly 500 is mounted on the housing 100. The guide rod 510 is fixed to the housing 100, the locking block 520 is movably mounted on the guide rod 510, and the elastic element 530 is connected to the locking block 520. The switching assembly 500 should not be understood as acting solely on the change of the guard 400's state during the switching action, but rather on maintaining the guard 400's state before and after the switching. For example, if the guard 400 is kept in the locked state, in which state it cannot be unintentionally unlocked, then the switching assembly 500 has a locking effect on the guard 400; or if the guard 400 is kept in the unlocked state, in which state it is subject to intentional external force, then under the action of this external force, the switching assembly 500 releases the locking state of the guard 400.

[0032] The guide rod 510 is a straight rod with a cross-section that can be circular, rectangular, or other irregular shapes, preferably a rectangular cross-section. The length of the guide rod 510 is less than the width of the head housing, allowing it to be directly installed in the space near the connection between the guard 400 and the housing 100 without modifying the existing internal structure of the power tool. The guide rod 510 is positioned between the housing 100 and the guard 400 and fixed to the housing 100. Furthermore, a support block 550 can be provided between the housing 100 and the guard 400, fixed to the housing 100, while the guide rod 510 is indirectly fixed to the housing 100 through its fixation to the support block 550. One end of the support block 550 is fixed to the housing 100, and the other end extends toward the protective cover 400, which makes it easy to limit the guide rod 510 between the protective cover 400 and the housing 100. At the same time, there is no need to change the original structure of the housing 100 or the protective cover 400, and there is no need to redesign or open a mold, thus saving costs.

[0033] The locking block 520 is movably mounted on the guide rod 510, limited by the guide rod 510, and reciprocates along the extension direction of the guide rod 510. The locking block 520 is block-shaped, hollow inside to fit onto the guide rod 510, and includes at least one outwardly protruding portion 521. The elastic member 530 is connected to the locking block 520, and they can generate forces to each other, thereby transferring kinetic energy or accumulating potential energy. The connection between the locking block 520 and the elastic member 530 can include abutment, detachable connection, or mutual fixation. The elastic member 530 can be confined to the guide rod 510, clamped between the locking block 520 and the housing 100, or disposed between the locking block 520 and the aforementioned support block 550. Preferably, the elastic element 530 is a spring, which is sleeved on the guide rod 510. The two ends of the spring are connected to the locking block 520 and the support block 550 respectively, such that the two ends of the spring abut against the opposite sides of the locking block 520 and the support block 550 respectively.

[0034] The protective cover 400 includes a coupling portion 410 that can engage with the locking block 520. The coupling portion 410 is specifically located on the side of the protective cover 400 used for mounting to the housing 100, and the opposite side of the protective cover 400 is the side closer to the working head 300. The locking block 520 has at least two position states and a movement path between the two position states, including a locked position maintaining engagement with the coupling portion 410, an unlocked position disengaging from the coupling portion 410, and a movement path from the locked position to the unlocked position. When the locking block 520 is in the locked position, the protective cover 400 cannot be unlocked by unintentional external force. This unintentional external force refers to an external force exceeding a certain degree applied in a single rotation direction of the protective cover 400, except as designed. This "certain degree" is affected by the elastic force of the elastic element 530 and the degree of engagement between the coupling portion 410 and the locking block 520, and can be adjusted through pre-design. The aforementioned "single rotation direction" refers to one of two opposing rotation directions included when the protective cover 400 can rotate circumferentially. Therefore, when the operator consciously needs to rotate the cover 400 in a single direction using a certain amount of force, the locking block 520 can be moved to the unlocked position, at which point the locking block 520 disengages from the coupling part 410. After disengaging, the locking block 520 no longer limits the cover 400, and the cover 400 can continue to rotate until the operator rotates the cover 400 to the desired position.

[0035] After rotating to the desired position, the cover 400 needs to re-enter the locked state, that is, the locking block 520 is in a locked position where it is re-engaged with the coupling part 410. In different embodiments, depending on the specifications of the cover 400 and the requirements of the corresponding power tools, the coupling part 410 is configured in different types, including protrusions or grooves distributed at different intervals. The area between adjacent protrusions or the groove itself can serve as the engagement area with the locking block 520. Each time the locking block 520 passes through an engagement area, the cover 400 rotates by a certain angle. Preferably, the locking block 520 switches between the locked and unlocked positions simultaneously, and travels a movement path from the locked position to the unlocked position and a return path from the unlocked position to the locked position.

[0036] The aforementioned movement path includes displacements that can be decomposed into two directions. The horizontal displacement compresses or stretches the elastic element 530 to accumulate its elastic restoring force, while the vertical displacement is primarily used for the disengagement of the locking block 520 from the coupling part 410. It should be noted that the horizontal and vertical displacements refer to displacement directions that are approximately 90° apart. The actual displacement direction of the locking block 520 lies between these horizontal and vertical displacement directions. Since the horizontal displacement is along the guide rod 510, the actual displacement direction of the locking block 520 is inclined relative to the guide rod 510 and is not perpendicular to the rotation plane of the protective cover 400. The guide rod 510 and the plane containing the protective cover 400 are approximately parallel. In another embodiment, the axis of the guide rod 510 is not parallel to any tangent line tangent to the circumferential rotation direction of the cover 400; that is, the guide rod 510 is also inclined relative to the cover 400 and not parallel to the plane in which the cover 400 is located. The rod of the guide rod 510 on the side closer to the locked position is closer to the cover 400 than the rod on the side closer to the unlocked position. Under the action of external force, the elastic element 530 can act on the locking block 520 to keep it in the locked position. The external force applied by the operator forces the elastic element 530 to store energy and allows the locking block 520 to be in the unlocked position. After the external force is released, the stored elastic restoring force allows the elastic element 530 to act on the locking block 520 to return it to the locked position.

[0037] The protective cover 400 has a connecting portion in its middle that connects to the housing 100. This connecting portion is hollow to allow passage of a transmission assembly for driving the working head 300. Around this hollow portion, protrusions can be stamped to engage with recesses on the housing 100. When the protrusions of the protective cover 400 engage with the recesses and rotate, the protective cover 400 is guided within the recesses on the housing 100, leaving it with only rotational freedom. An O-ring can be provided between the housing 100 and the protective cover 400 to reduce wobbling during their fit.

[0038] In one embodiment, the coupling portion 410 includes a plurality of protruding ribs 411 spaced apart along the rotation direction of the cover 400. The protruding ribs 411 can be arranged around the protrusion, wherein when the protrusion is cylindrical, the plurality of protruding ribs 411 are distributed in a ring-like space. The locking block 520 includes a protrusion 521, which can be vertically inserted between two adjacent protruding ribs 411 to engage the locking block 520 with the coupling portion 410. The length of the protrusion 521 is not less than the aforementioned vertical displacement distance, and the width of the protrusion 521 is not greater than the distance between two adjacent protruding ribs 411. The front and rear sides of the protrusion 521 along the aforementioned horizontal displacement direction are respectively a first side surface 522 and a second side surface 523, and the two side surfaces correspond to two adjacent protruding ribs 411 respectively. The operator rotates the cover 400 in a forward direction to unlock it, and in a reverse direction to unlock it. The first side panel 522 and the second side panel 523 are positioned along the forward rotation direction. At least part of the first side panel 522 is a slope, allowing the raised rib 411 and the protrusion 521 to slide smoothly relative to each other when the cover 400 is rotated forward and an attempt is made to unlock it, thus disengaging the locking block 520 from its locked position. Preferably, the top of the protrusion 521 is chamfered to form the aforementioned slope. The second side panel 523 is a flat surface, preventing the raised rib 411 and the protrusion 521 from sliding easily when the cover 400 is subjected to a reverse external force, thus preventing the cover 400 from rotating in the reverse direction.

[0039] To guide and limit the locking block 520, the guide rod 510 is provided with a groove or through hole, and the locking block 520 is slidably connected to the guide rod 510 through the groove or through hole. Furthermore, the locking block 520 and the guide rod 510 are connected by a fixing pin 540, one end of which can be secured with a snap ring. The guide rod 510 is provided with a slotted hole 511, and the locking block 520 is provided with a corresponding connecting hole 524. The fixing pin 540 passes through the slotted hole 511 and the connecting hole 524, and can reciprocate along the slotted hole 511. The outer diameter of the fixing pin 540 is the same as or similar to the inner diameter of the connecting hole 524 and the width of the slotted hole 511, making it difficult for the locking block 520 to wobble on the fixing pin 540 and relative to the slotted hole 511. The length of the waist-shaped hole 511 is the same as or slightly greater than the distance of the moving path of the locking block 520. The locking block 520 is in the locked position when it slides to one end of the groove or through hole, and in the unlocked position when it slides to the opposite end. For example, when the guide rod 510 is provided with a waist-shaped hole 511, the above-mentioned locked and unlocked positions are located at the positions after the locking block 520 slides to both ends of the waist-shaped hole 511.

[0040] The switching assembly 500 also includes a pair of support blocks 550 fixed to the housing 100 at intervals, and the two ends of the guide rod 510 are respectively fixed to the pair of support blocks 550. In one embodiment, the elastic element 530 is a compression spring, which is sleeved on the guide rod 510, and its two ends abut against the locking block 520 and the support block 550 respectively. In another embodiment, the elastic element 530 is a tension spring, which is sleeved on the guide rod 510, and its two ends are fixed to the locking block 520 and the support block 550 respectively. In different embodiments using tension springs or compression springs, the tension springs and compression springs are located on different sides of the locking block 520, and the locking block 520 is reset by elastic restoring force and tension force respectively, while the structure of other parts of the power tool remains the same.

[0041] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative power tools can be developed without departing from the principles and scope of this invention. The scope of protection of this invention is defined by the claims.

Claims

1. A power tool, comprising a housing, a motor housed within the housing, a working head coupled to the motor, and a protective cover partially housing the working head, the protective cover being rotatably disposed within the housing, characterized in that: The power tool further includes a switching assembly disposed on the housing. The switching assembly includes a guide rod fixed to the housing, a locking block movably disposed on the guide rod, and an elastic element connected to the locking block. The protective cover includes a coupling portion that can engage with the locking block. The locking block has a locked position that is engaged with the coupling portion, an unlocked position that is disengaged from the coupling portion, and a movement path from the locked position to the unlocked position. The movement path includes a horizontal displacement that accumulates the elastic restoring force of the elastic element and a vertical displacement that disengages from the coupling portion. The protective cover is circumferentially rotatable, specifically including two mutually opposite rotational directions. When the locking block is in the locked position, the protective cover can only be unlocked in one of the directions.

2. The power tool according to claim 1, characterized in that: The coupling part includes a plurality of protruding ribs spaced apart along the rotation direction of the cover, and the locking block includes a protrusion that can be vertically inserted between two adjacent protruding ribs to engage the locking block with the coupling part.

3. The power tool according to claim 2, characterized in that: The front and rear sides of the protrusion along the horizontal displacement direction are respectively the first side and the second side, at least part of the first side is an inclined surface, and the second side is a plane.

4. The power tool according to claim 1, characterized in that: The guide rod is provided with a groove or a through hole, and the locking block is slidably connected to the guide rod through the groove or through hole.

5. The power tool according to claim 4, characterized in that: The locking block and the guide rod are connected by a fixing pin. The guide rod has a waist-shaped hole, and the locking block has a connecting hole corresponding to the waist-shaped hole. The fixing pin passes through the waist-shaped hole and the connecting hole, and the fixing pin can reciprocate along the waist-shaped hole.

6. The power tool according to claim 4, characterized in that: When the card block slides to one end of the groove or through hole, it is in the locked position; when it slides to the opposite end, it is in the unlocked position.

7. The power tool according to claim 1, characterized in that: The axis of the guide rod is not parallel to any tangent line that is tangent to the circumferential rotation direction of the shield.

8. The power tool according to claim 1, characterized in that: The switching assembly also includes a pair of support blocks fixed to the housing at intervals, and the two ends of the guide rod are respectively fixed to the pair of support blocks.

9. The power tool according to claim 8, characterized in that: The elastic element is a compression spring, and the two ends of the compression spring abut against the locking block and the support block, respectively.

10. The power tool according to claim 8, characterized in that: The elastic element is a tension spring, and the two ends of the tension spring are fixed to the locking block and the support block, respectively.

Images