Protection mechanism for a power tool and power tool

Abstract

Protective mechanism for a power tool, designed to be arranged on a housing of the power tool to protect a cutting tool of the power tool, characterized in that the protective mechanism comprises: a protective hood (100) which serves to be rotatably arranged on the housing of the power tool, wherein the protective hood can be rotated about its axis of rotation in order to switch between an open working position and a closed working position; an operating rod (200) which serves to be rotatably arranged on the housing of the power tool, wherein the operating rod has a force application end (202) and a connecting end (203); a gear arrangement comprising a gear structure (300) with a gear ratio other than one and connected to the connecting end of the operating rod; wherein the operating rod and the gear assembly are configured such that when the force application end of the operating rod is subjected to an external force, the operating rod is rotated about its axis of rotation (201) by a first angle, thereby causing the gear assembly connected to it to rotate, which pushes the protective hood to rotate by a third angle in order to change the protective hood from the closed working position to the open working position; wherein the first angle is smaller than the third angle.

Description

Technical field

[0001] The present invention relates to a protective device, in particular a protective device for use on a cutting tool side of a power tool. State of the art

[0002] In various work scenarios, such as woodworking and metalworking, power tools with sharp cutting tools are often required, which is why ensuring the operator's safety is of crucial importance.

[0003] To ensure operator safety, some power tools are currently equipped with a protective hood on the cutting tool side. When not in use, the hood is positioned around the cutting tool, covering it for protection. When the cutting tool is in operation, the workpiece automatically pushes the hood aside, allowing the cutting process to proceed smoothly. However, due to complex conditions in practical operating scenarios, such as workpieces with rough surfaces, protrusions, or unevenness, the protective hood may often fail to open automatically.

[0004] Therefore, some power tools are equipped with a protective guard that can be opened manually. However, the current guard must be opened so far that it reaches the fully open position, requiring a greater range of motion from the operator. This not only increases the complexity of operation but is also limited by the restricted operating space. Disclosure of the invention

[0005] One of the objectives of the present invention is to provide a protective mechanism for a power tool that can offer safe and effective protection for the power tool while also allowing convenient opening of the protective cover.

[0006] To achieve the above-mentioned objective, the present invention provides a protective mechanism for a power tool, which serves to be arranged on a housing of the power tool in order to protect a cutting tool of the power tool, wherein the protective mechanism comprises: a protective hood which serves to be rotatably arranged on the housing of the power tool, wherein the protective hood can be rotated about its axis of rotation in order to switch between an open working position and a closed working position; an operating rod which serves to be rotatably arranged on the housing of the power tool, wherein the operating rod has a force application end and a connecting end; a gear arrangement comprising a gear structure with a gear ratio other than one and connected to the connecting end of the operating rod; wherein the operating rod and the gear assembly are configured such that when the force application end of the operating rod is subjected to an external force, the operating rod is rotated about its axis of rotation by a first angle, thereby causing the gear assembly connected to it to rotate, which pushes the protective hood to rotate by a third angle in order to change the protective hood from the closed working position to the open working position; wherein the first angle is smaller than the third angle.

[0007] Another object of the present invention is to provide a power tool that offers improved operational safety and ease of use, thereby achieving an optimal user experience.

[0008] Based on this, the present invention further provides a power tool that includes a protective mechanism described above.

[0009] A safety mechanism for a power tool according to the present invention allows for convenient opening of the guard, provided that the operator's safety is ensured during use. Therefore, the operator can, with a small range of motion—that is, by rotating the operating rod a small angle—rotate the guard a larger angle, thereby fully opening it. In this way, safety during operation of the power tool is ensured, and the user experience is improved. Brief description of the drawings Fig. Figure 1 schematically shows an electric tool applicable to the present invention from a front perspective in a state in which a protective hood is in a closed working position. Fig. Figure 2 schematically shows the power tool applicable to the present invention from a front perspective in a state in which the protective hood is in an open working position. Fig. Figure 3 schematically shows an electric tool applicable to the present invention from a rear perspective in a state in which a protective hood is in a closed working position. Fig. Figure 4 schematically shows the power tool applicable to the present invention from a rear perspective in a state in which the protective hood is in an open working position. Fig. Figure 5 shows an operating rod of a protective mechanism of the present invention in one embodiment in an enlarged view. Fig. Figure 6 schematically shows the operating rod of the protective mechanism of the present invention, rotated by a first angle in one embodiment. Fig. Figure 7 shows a gear structure of the protection mechanism of the present invention in one embodiment. Fig. Figure 8 shows the arrangement of a first gear of the protective mechanism of the present invention in one embodiment from a partially cutaway perspective. Fig. Figure 9 shows the arrangement of a second gear of the protective mechanism of the present invention in one embodiment from a partially cutaway perspective. Fig. Figure 10 shows a structure of one side of the protection mechanism of the present invention in an embodiment in which the first gear of the transmission structure is connected to the operating rod. Detailed descriptions

[0010] A protective mechanism for a power tool and a power tool according to the present invention are explained and described in more detail below in conjunction with the accompanying drawings, description, and specific embodiments. This explanation and description, however, do not constitute an unreasonable limitation of the technical solution of the present invention.

[0011] Power tools, such as portable power tools, often require sharp cutting tools for various operations on workpieces, including cutting. Therefore, ensuring operator safety is crucial. For protection, such power tools are typically equipped with a guard that covers the cutting tool. During operation, the movable guard is pushed aside by the workpiece as the power tool moves forward and penetrates it. However, due to complex conditions in practical operating scenarios, such as workpieces with rough surfaces, protrusions, or unevenness, the guard may not open automatically.

[0012] Therefore, some power tools are equipped with a protective guard that can be opened manually. However, the current guard must be opened so far that it reaches the fully open position, requiring a greater range of motion from the operator. This not only increases the complexity of operation but is also limited by the restricted operating space.

[0013] Based on this, the present invention, in one embodiment, provides a protective mechanism for a power tool that protects the cutting tool of the power tool while simultaneously enabling convenient opening.

[0014] Fig. 1 and Fig. Figure 2 schematically shows a power tool, for example an electric circular saw, which is applicable to the present invention.

[0015] The electric circular saw uses an electric motor to drive the tool head, for example the saw blade, to move in order to cut the material to be cut.

[0016] It should be noted that, although in Fig. 1 and Fig. Figure 2 schematically shows an electric circular saw; the protective mechanism described in the present invention is not limited in its application to circular saws, but is also applicable to other power tools with sharp cutting tools, such as cutting machines with grinding wheels.

[0017] As in Fig. 1 and Fig. As shown in Figure 2, the protective mechanism in this embodiment comprises a protective hood 100 which is arranged peripherally around a cutting tool, wherein the protective hood 100 can be changed between an open working position and a closed working position. Fig. Figure 1 shows a state in which the protective hood is in the closed working position. Fig. Figure 2 shows a state in which the protective hood 100 is in the open working position.

[0018] In some more specific embodiments, the protective hood can comprise a stationary hood body 102, which is fixedly arranged on the housing of the power tool, and a movable hood body 101, which is rotatably arranged on the housing of the power tool via a pivot axis 103. The movable hood body 101 can be opened or closed relative to the stationary hood body 102. Fig. Figure 1 shows a state in which the movable hood body is closed relative to the stationary hood body 102. When the movable hood body 101 is closed relative to the stationary hood body 102 as shown in Figure 1, the hood body is closed relative to the stationary hood body 102. Fig. When the movable hood body 101 is rotated clockwise (as shown in Figure 1), it opens relative to the stationary hood body 102, thereby creating a Fig. Position 2 shown is reached, and thus the protective hood changes from the closed working position to the open working position.

[0019] As in Fig. 1 and Fig. As shown in Figure 2, in some embodiments a buffer element 500 can be arranged between the stationary hood body 102 and the movable hood body 101 to prevent the movable hood body 101 from causing excessive impact on the stationary hood body 102 when changing from the open working position to the closed working position. In some more specific embodiments, this buffer element can be a rubber pad, a buffer spring, or another similar element that can provide damping and shock absorption.

[0020] It should be noted that in other, more specific embodiments, the protective hood may also be provided only with the movable hood body 101, without the fixed hood body. The movable hood body 101 is arranged peripherally around the cutting tool and covers it. When the protective hood is opened or closed, the movable hood body 101 opens or closes relative to the housing of the power tool.

[0021] As in Fig. 3 and Fig. As shown in Figure 4, the protective mechanism further comprises an operating rod 200 which is rotatably arranged on the housing of the power tool so that it can rotate about a pivot axis 201 of the operating rod.

[0022] In some more specific embodiments, it is provided that, if the protective hood comprises the stationary hood body 102, which is fixedly arranged on the housing, the operating rod 200 can be rotatably attached to the stationary hood body 102 via a washer 120 and a connecting element 110, for example a screw (as, for example, in Fig. 8 shown), which allows the operating rod 200 to be rotatably arranged on the housing of the power tool.

[0023] The protective mechanism further comprises a gear arrangement located between the protective hood and the operating rod 200 to amplify the rotary motion of the operating rod and transmit it to the protective hood, the gear arrangement comprising at least one gear structure 300 with a gear ratio other than one, whereby, when a force application end of the operating rod is subjected to an external force, the operating rod is rotated about its axis of rotation 201 by a first angle and then the gear arrangement connected to it is set into rotation, thereby pushing the protective hood to rotate by a third angle greater than the first angle in order to change the protective hood from the closed working position to the open working position.

[0024] Since the gear ratio of the transmission structure in this process is not equal to one, the first angle α1, by which the operating rod 200 was rotated, is smaller than the third angle α3, by which the protective hood was rotated when opening. Therefore, the rotation path of the operating rod 200 is significantly smaller than the opening path of the protective hood. This arrangement allows the operator to open the protective hood by a larger angle by rotating the operating rod only a relatively small angle, thus achieving convenient and rapid opening of the protective hood and also saving operating space.

[0025] It should be noted that the improvement of the present invention lies in the arrangement of the operating rod 200, the gear assembly, and the protective hood, enabling the operator to rotate the operating rod by a relatively small angle when needed, thereby opening the protective hood by a large angle according to the interrelationship between them, without restricting the protective hood to being opened exclusively via the operating rod. Under certain working conditions, the protective hood can be opened by sliding it away from the workpiece. However, even in this case, this does not contradict the technical objective achieved by the present invention.

[0026] In some more specific embodiments, the gear arrangement can further comprise a switching rod 400, which is arranged downstream of the gear structure 300 in the direction of rotary motion transmission; that is, the switching rod is arranged between the gear structure and the guard. According to this arrangement, the rotary motion of the operating rod is transmitted to the switching rod 400 connected to the gear structure. In some more specific embodiments, the switching rod 400 is rotatably mounted on the housing of the power tool and is operatively connected to the guard, thereby pushing the guard from the closed working position to the open working position.

[0027] As in Fig. 3, Fig. 4 and Fig. As shown in Figure 5, the operating rod 200 specifically has a force application end 202, on which the operator exerts an external force, and a connection end 203, which is connected to the transmission structure. When the force application end of the operating rod 200 is subjected to an external force, for example in a Fig. 3, Fig. 4 and Fig. In the direction shown in Figure 5, by the operator pressing downwards the force-actuated end 202 of the operating rod 200, the operating rod 200 rotates counterclockwise about its axis of rotation 201 by a first angle α1, causing the gear structure 300 connected to it to rotate. Then, the shift rod 400 connected to the gear structure 300 is in turn set into rotation counterclockwise about an axis of rotation 401 of the shift rod by a second angle α2 (when viewed from the perspective of Fig. 1 and Fig. 2. The rotation is clockwise by the second angle). This also causes the protective cover to rotate counterclockwise around the axis of rotation 103 by the third angle α3 (when viewed from the perspective of Fig. 1 and Fig. 2. The rotation is clockwise by the third angle), whereby the protective cover is removed from the in Fig. 3 shown closed working position in the in Fig. The open working position shown in section 4 is pushed.

[0028] Since the gear ratio of the transmission structure in this process is not equal to one, as in Fig. 4 and Fig. As shown in Figure 6, the first angle α1, around which the operating rod 200 was rotated, is smaller than the second angle α2, around which the switching rod 400 was rotated, and the third angle α3, around which the protective cover was rotated when opening. Therefore, the rotation path of the operating rod 200 is significantly smaller than the opening path of the protective cover.

[0029] In an embodiment in which the protective hood comprises the stationary hood body 102 and the movable hood body 101, it is provided that when the switching rod 400 is rotated about its axis of rotation 401 by the second angle, the movable hood body 101 is pushed to rotate relative to the stationary hood body 102 and thus opened in order to push the protective hood from the closed working position to the open working position.

[0030] It should be noted that the foregoing description represents only one embodiment of the present invention. Opening the protective cover by the operator pressing down the operating rod can significantly improve the user experience. In other embodiments, however, the force-actuating end of the operating rod can also be lifted by the operator, thereby configuring the operating rod and the switching rod, according to the user's actual application requirements, to rotate in the opposite direction to that described above.

[0031] In the embodiment described above, the direction of rotation of the operating rod 200, when moving the protective hood from the closed working position to the open working position, coincides with the direction of rotation of the switching rod 400 and the direction of rotation of the protective hood. Since the operating rod and the switching rod are each rods with a specific extension length, the directions of rotation of the operating rod 200, the switching rod 400, and the protective hood are identical in the embodiment described above, in order to save space for the arrangement and the operating area.

[0032] However, it can be seen that in other embodiments the direction of rotation of the operating rod 200 is the same as or opposite to the direction of rotation of the switching rod 400, and that the direction of rotation of the switching rod may also be the same as or opposite to the direction of rotation of the protective hood.

[0033] Furthermore, as in Fig. Figure 4 shows that in some embodiments the pivot axis 201 of the operating rod 200 is arranged at its connecting end 203. This arrangement allows for a further simplification of the structural design of the entire device and a reduction in the relevant components.

[0034] Of course, in other embodiments, the connecting end and the force application end of the operating rod can each be arranged on two sides of the axis of rotation of the operating rod, and the distance of the force application end to the axis of rotation can be adjusted by a person skilled in this field as needed to achieve a saving of force.

[0035] In some embodiments, the transmission structure 300 may include a gear transmission structure with a gear ratio other than one.

[0036] For example, the gear drive structure can be found in some more specific embodiments, such as in Fig. Figure 7 shows a first gear 301 and a second gear 302, which meshes with the first gear. As shown in Fig. As shown in Figure 8, the first gear 301 is rotatably arranged about its own axis on the housing of the power tool via its central bore 3013, more precisely, rotatably on the stationary hood body 102. As shown in Fig. As shown in Figure 7, the first gear 301 has an internal tooth ring 3014 on one side opposite its side connected to the connecting end of the operating rod, and the second gear 302 with an external tooth ring engages with the first gear.

[0037] As in Fig. As shown in Figure 9, in some exemplary embodiments the second gear 302 is rotatably mounted about its own axis on the housing of the power tool, more precisely, rotatably on the stationary hood body 102, via a bearing 303, for example a ball bearing. The switching rod 400 is pressed onto the shaft of the second gear via its central bore with a press fit, thereby achieving a coaxial connection with the second gear and synchronous rotation with it.

[0038] As in Fig. As shown in Figure 10, in some more specific embodiments, a recess 3012 is provided on the side of the first gear 301 connected to the operating rod to enable synchronous rotation of the first gear 301 and the operating rod 200. The connecting end of the operating rod is arranged accordingly in this recess, the inner wall of which has a projection 3011 directed radially towards the center of the first gear. The connecting end of the operating rod is provided with a locking groove that fits this projection. In this way, the operating rod is fixedly arranged circumferentially relative to the first gear, allowing the first gear to be arranged coaxially with the operating rod and to rotate synchronously with it.

[0039] This arrangement ensures that the direction of rotation of the second gear is identical to that of the first gear. Through a relatively simple structural design, this embodiment achieves the synchronous rotation of the operating rod and the switching rod, and, thanks to the gear ratio of the gear structure, allows the operator to open the protective cover by a larger angle by rotating the operating rod by a small angle.

[0040] It is evident that during the transmission process, the rotation angle 1 of the control rod 200 (i.e., the first rotation angle α1 by which the control rod is rotated) is equal to the rotation angle 2 of the first gear 301. Furthermore, the rotation angle 3 of the second gear 302 is equal to the rotation angle 5 of the shift rod (i.e., the second rotation angle α2 by which the shift rod is rotated).

[0041] Due to the inherent properties of the gear structure, the gear ring diameter d2 of the first gear 301 and the gear ring diameter d3 of the second gear 302, as well as the number of teeth Z2 of the first gear 301 and the number of teeth Z3 of the second gear, satisfy the following relationship: θ2×d22=θ3×d32 θ1θ5=d3d2=z3z2

[0042] Therefore, in some embodiments, the transmission ratio of the gear structure can be adjusted by setting the ratio of the number of teeth of the first gear 301 to the number of teeth of the second gear 302, thereby adjusting, as required, the relationship between the first angle of rotation by which the operating rod was turned and the second angle of rotation by which the shift rod was turned, and again the relationship between the first angle of rotation by which the operating rod was turned and the third angle of rotation by which the protective cover was turned.

[0043] In some more specific embodiments, the ratio of the number of teeth Z2 of the inner gear ring of the first gear to the number of teeth Z3 of the outer gear ring of the second gear can be (27 to 66) : (10 to 15). It must be specifically stated that the number of teeth is not determined as continuous values ​​within this range, but as discrete values ​​within this range, provided that the basic engagement conditions of the gears are met.

[0044] In a specific example, the ratio of the number of teeth Z2 of the inner ring gear of the first gear to the number of teeth Z3 of the outer ring gear of the second gear can be 45:13. Accordingly, the shift rod 400 is rotated by 35.1° when the operating rod is rotated by only 10.14°.

[0045] This design, through the use of the gear drive structure, ensures a stable transmission structure and allows for easy adjustment of the transmission ratio.

[0046] Of course, other gear drive structures can also be used in other embodiments, for example by inserting a transition gear between the first gear and the second gear, which is in mesh with both the first and second gears, thereby achieving a rotation in the same direction of the first gear and the second gear, even if the first gear and the second gear are each provided with an outer tooth ring.

[0047] Furthermore, in other embodiments, the transmission structure may not be limited to a gear transmission structure. For example, the transmission structure may also include a sprocket structure, a pulley structure, or a similar structure with a gear ratio other than one.

[0048] As in Fig. As shown in Figure 7, in some more specific embodiments, the shift rod 400 has a first arm section 402, which is connected to the transmission structure, and a second arm section 403, which is curved relative to the first arm section. A push rod 404 is arranged at a rear end of the second arm section and is in contact with the protective cover. When the shift rod rotates about its axis of rotation 401 by the second angle, the push rod pushes the protective cover to rotate by the third angle, thus moving it from the closed working position to the open working position. This embodiment, by providing a curved shift rod and a push rod at the rear end of the shift rod that is in contact with the protective cover, ensures that the rotation curve of the protective cover is linked to the rotation angle of the shift rod and that the third angle is larger than the second angle.This achieves, with the simplest possible structural design, that the third angle is larger than the second angle and the second angle is larger than the first, resulting in further savings in operating space. In a specific example, if the control rod 400 is rotated by only 10.14°, the control rod 400 can be rotated by 35.1° based on the gear ratio, allowing the third rotation angle, by which the protective cover is rotated, to reach 60°.

[0049] As in Fig. 5 and Fig. As shown in Figure 6, in some embodiments the protective mechanism may further comprise a first elastic element 600 connected between the operating rod 200 and the housing of the power tool to exert an elastic restoring force on the operating rod. For example, when the operating rod 200 is pressed downwards, the first elastic element 600 is stretched, creating an elastic preload force. When the external force exerted on the operating rod 200 is released, the operating rod therefore rotates under the influence of the elastic restoring force in a direction opposite to the rotational movement in which the protective cover is opened, in order to effect the return to its original position. In some more specific embodiments, the first elastic element 600 may comprise a first helical spring.Of course, in other embodiments the first elastic element can also be a disc spring, a torsion spring, a leaf spring or a similar component that exerts an elastic force.

[0050] As in Fig. 1 and Fig. As shown in Figure 2, in some embodiments the protective mechanism may further comprise a second elastic element 700, which is connected between the switching rod 400 and the housing of the power tool in order to exert an elastic restoring force on the switching rod. For example, if the switching rod 400, as shown in Figure 2, is connected to the housing of the power tool, the protective mechanism may be further extended by a second elastic element 700, which is connected between the switching rod 400 and the housing of the power tool to exert an elastic restoring force on the switching rod. Fig. As shown in Figure 1, when rotated clockwise, the second elastic element 700 is stretched, creating an elastic preload. When the force exerted on the shift rod is released, the shift rod 400 therefore rotates under the influence of the elastic restoring force, as shown in Figure 1. Fig.Figure 1 shows the second elastic element rotating counterclockwise to effect the return. In some more specific embodiments, the second elastic element 700 can comprise a second helical spring. Of course, in other embodiments, the second elastic element can also be a disc spring, a torsion spring, a leaf spring, or a similar component that exerts an elastic force.

[0051] In one embodiment, the present invention further provides a power tool which has the protective mechanism described above, wherein the protective hood is arranged peripherally around and covers a cutting tool of the power tool, thereby achieving the protective function and simultaneously improving the user experience for the operator.

[0052] In some more specific embodiments, the power tool can be an electric circular saw.

[0053] It should be noted that the processes described in the present invention, both clockwise and counterclockwise, are exemplary descriptions with reference to the corresponding drawings and do not represent a limitation of the technical solution of the present invention.

[0054] It should be noted that the prior art within the scope of protection of the invention is not limited to the embodiments specified herein, and that prior art which is not in conflict with the solutions according to the invention, including but not limited to previous patent documents, publications, disclosures, etc., may be included within the scope of protection of the invention.

[0055] Furthermore, the combination of the individual technical features herein is not limited to the combinations described in the claims or the combinations described in the specific embodiments. All technical features described herein can be freely combined or connected in any way, as long as they do not contradict each other.

[0056] It should also be noted that the embodiments listed above are only specific embodiments of the present invention. Obviously, the present invention is not limited to the aforementioned embodiments. And similar modifications or variations that are made as a consequence and that can be directly derived by a person skilled in the art from the disclosed content of the present invention or easily devised are to fall within the scope of protection of the present invention.

Claims

[1] Protective mechanism for a power tool, designed to be arranged on the housing of the power tool to protect a cutting tool of the power tool, characterized by , that the protection mechanism includes: a protective hood (100) which serves to be rotatably arranged on the housing of the power tool, wherein the protective hood can be rotated about its axis of rotation in order to switch between an open working position and a closed working position; an operating rod (200) which serves to be rotatably arranged on the housing of the power tool, wherein the operating rod has a force application end (202) and a connecting end (203); a gear arrangement comprising a gear structure (300) with a gear ratio other than one and connected to the connecting end of the operating rod; wherein the operating rod and the gear assembly are configured such that when the force application end of the operating rod is subjected to an external force, the operating rod is rotated about its axis of rotation (201) by a first angle, thereby causing the gear assembly connected to it to rotate, which pushes the protective hood to rotate by a third angle in order to change the protective hood from the closed working position to the open working position; wherein the first angle is smaller than the third angle. [2] Protection mechanism according to claim 1, characterized by, that the transmission arrangement further comprises a shift rod (400) which serves to be rotatably arranged on the housing of the power tool, wherein the shift rod is connected to the transmission structure and is operatively connected to the protective hood, wherein, when the operating rod rotates about its axis of rotation (201) by the first angle, it causes the shift rod connected to the transmission structure to rotate about an axis of rotation (401) of the shift rod by a second angle, whereby the shift rod pushes the protective hood to rotate by the third angle, wherein the first angle is smaller than the second angle. [3] Protection mechanism according to claim 2, characterized by, that the shift rod has a first arm section (402) which is connected to the transmission structure and a second arm section (403) which is curved relative to the first arm section, wherein a push rod (404) is arranged at the rear end of the second arm section which is in contact with the protective hood, wherein when the shift rod is rotated about its axis of rotation by the second angle, the push rod pushes the protective hood to rotate by the third angle, and wherein the second angle is smaller than the third angle. [4] Protection mechanism according to claim 1, characterized by that the pivot axis of the operating rod is located at its connecting end. [5] Protection mechanism according to claim 2, characterized by, that when the protective hood moves from the closed working position to the open working position, the direction of rotation of the operating rod coincides with the direction of rotation of the switching rod and the direction of rotation of the protective hood. [6] Protection mechanism according to claim 1, characterized by , that it further comprises: a first elastic element (600) connected between the operating rod and the housing of the power tool to exert an elastic restoring force on the operating rod. [7] Protection mechanism according to claim 6, characterized by , that the first elastic element comprises a first helical spring. [8] Protection mechanism according to claim 2, characterized by , that it further comprises: a second elastic element (700) connected between the shift rod and the housing of the power tool to exert an elastic restoring force on the shift rod. [9] Protection mechanism according to claim 8, characterized bythat the second elastic element includes a second helical spring. [10] Protection mechanism according to claim 1, characterized by , that the protective hood comprises a fixed hood body (102) which is fixedly arranged on the housing of the power tool and a movable hood body (101) which is rotatably arranged on the housing of the power tool, wherein the movable hood body is rotated and opened by the rotation of the switching rod about its axis of rotation by the second angle relative to the fixed hood body in order to move the protective hood from the closed working position to the open working position. [11] Protection mechanism according to any one of claims 1 to 10, characterized by , that the transmission structure comprises a gear transmission structure with a gear ratio other than one. [12] Protection mechanism according to claim 11, characterized by , that the gear drive structure includes: a first gear (301) which is coaxially connected to the connecting end of the operating rod and rotates synchronously with the operating rod, the first gear having an internal toothed ring; and a second gear (302) having an outer gear ring meshing with the inner gear ring of the first gear, wherein the second gear is coaxially connected to the shift rod to cause the shift rod to rotate synchronously with the second gear. [13] Protection mechanism according to claim 12, characterized by , that the first gear has a radially directed elevation (3011) on its side connected with the operating rod, the center of the first gear being provided with a detent groove matching the elevation. [14] Protection mechanism according to claim 12, characterized by, that the ratio of the number of teeth of the inner gear ring of the first gear to the number of teeth of the outer gear ring of the second gear is (27 to 66) : (10 to 15). [15] Power tool, characterized by , that it comprises a protective mechanism according to one of claims 1 to 14, wherein the protective hood is arranged peripherally around and covers a cutting tool of the power tool.

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