Power tool

Abstract

The utility model provides an electric tool, including the casing, the motor in the casing and the work head driven by the motor, and the casing includes the main casing of accommodating the motor and the handle casing connected to the main casing, and the work head at least partially exposes in the main casing, wherein, the electric tool includes the elastic member connected with the handle casing and the main casing and the safety switch in the handle casing, and the handle casing is connected to the main casing through the elastic member, and the safety switch is electrically connected to the motor, when the handle casing moves towards the main casing and overcomes the elastic force of the elastic member, the safety switch is triggered and is disconnected the motor, when the electric tool is overloaded, the thrust applied to the handle casing overcomes the elastic force of the elastic member and makes the handle casing move towards the main casing and thus triggers the safety switch, and the control circuit of the motor is disconnected in time, and the electric tool is effectively protected from overload, solves the problem of the motor burning due to overload without setting the controller, and overcomes the defects of the prior art.

Description

[Technical Field]

[0001] This invention relates to the technical field of power tools, and more particularly to an electric circular saw for cutting tools. [Background Technology]

[0002] An electric circular saw is a tool that uses an electric motor to drive a circular saw blade through a transmission mechanism for cutting operations. Electric circular saws are suitable for cutting materials such as wood, fiberboard, plastics, and flexible cables, and have advantages such as safety, reliability, reasonable structure, and high work efficiency. However, most existing AC or DC brushed electric circular saws lack a controller and overload protection, making them prone to burnout due to overload during operation.

[0003] Therefore, it is indeed necessary to improve the existing technology and provide an electric circular saw that can effectively avoid overload and burnout in order to solve the above problems. [Summary of the Invention]

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an electric tool that can provide overload protection for machines that do not have a controller protection program.

[0005] The present invention addresses the problems of the prior art by adopting the following technical solution: an electric tool includes a housing, a motor located within the housing, and a working head driven by the motor. The housing includes a main housing housing the motor and a handle housing connected to the main housing. The working head is at least partially exposed within the main housing. The electric tool includes an elastic element connecting the handle housing and the main housing, and a safety switch located within the handle housing. The handle housing is floatingly connected to the main housing via the elastic element, and the safety switch is electrically connected to the motor. When the handle housing moves towards the main housing against the elastic force of the elastic element, the safety switch is triggered and disconnects the motor.

[0006] A further improvement is as follows: the safety switch is provided with a triggering part that can be pressed and activated; the main housing is provided with an action member that is positioned toward the triggering part; the elastic force of the elastic member causes the handle housing to move the safety switch away from the action member; when the handle housing moves toward the main housing against the elastic force of the elastic member, the triggering part presses against the action member, thereby activating the safety switch.

[0007] A further improvement is as follows: one end of the elastic element is connected to the main housing and the other end is connected to the handle housing, and the safety switch is disposed adjacent to the elastic element.

[0008] A further improvement is as follows: the main housing has a cavity that opens toward the handle housing, the handle housing has a receiving sleeve corresponding to the cavity, and the two ends of the elastic member are respectively housed in the cavity and the receiving sleeve, so as to be pre-tightly placed between the handle housing and the main housing.

[0009] A further improvement is as follows: the handle housing is C-shaped and has a first end and a second end. The first end houses the safety switch and is floatingly connected to the main housing. The second end is pivotally connected to the main housing around a pivot axis.

[0010] A further improvement is as follows: the working head rotates around a rotating axis to perform the cutting operation, and the pivot is set parallel to the rotating axis.

[0011] A further improvement is that the first end is tangent to the rotational surface of the working head along the extension direction of the elastic element.

[0012] A further improvement is that the handle housing includes a grip portion located between the first end and the second end.

[0013] A further improvement is that the power tool also includes a main switch located in the grip, the main switch being used to control the start and stop of the motor and being connected in series with the safety switch.

[0014] A further improvement is as follows: the handle housing further includes a secondary handle connected to the handle housing. The secondary handle has a connecting portion extending outward from the first end and a grip located at the free end of the connecting portion. The angle between the extension direction of the connecting portion and the extension direction of the elastic element is an acute angle.

[0015] Compared with the prior art, the present invention has the following beneficial effects: When the power tool is overloaded, the thrust applied to the handle housing overcomes the elastic force of the elastic element, causing the handle housing to move toward the main housing, thereby triggering the safety switch and disconnecting the motor control circuit in time, thus providing effective overload protection for the power tool. This solves the problem of motor burnout due to overload without a controller and overcomes the defects of the prior art. [Image Description]

[0016] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0017] Figure 1 This is a cross-sectional view of the power tool of the present invention in its normal operating state;

[0018] Figure 2 yes Figure 1 An exploded view of some parts of the structure of a power tool;

[0019] Figure 3 yes Figure 1 The power tool shown is a cross-sectional view under overload conditions.

[0020] Meaning of the reference numerals in the diagram:

[0021] 100. Electric circular saw; 1. Main housing; 11. Rotating shaft

[0022] 12. Pivot 13. Cavity 14. Actuating element

[0023] 2. Handle housing 21, first end 22, second end

[0024] 24. Grip part; 25. Secondary handle; 251. Connecting part

[0025] 253, handle 3, safety switch 31, trigger unit

[0026] 5. Elastic component 51. Receiving sleeve [Detailed Implementation]

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0028] Please see Figure 1-3 As shown, this embodiment uses an electric circular saw 100 as an example to describe the power tool involved in the present invention. Of course, in other embodiments, the power tool may also be a reciprocating saw, a cutting machine or other cutting tools.

[0029] The electric circular saw 100 includes a housing, a motor located within the housing, and a working head driven by the motor. The housing includes a main housing 1 housing the motor and a handle housing 2 connected to the main housing 1. The working head is at least partially exposed in the main housing 1. The power tool includes an elastic element 5 connected to the handle housing 2 and the main housing 1, and a safety switch 3 located within the handle housing 2. The handle housing 2 is floatingly connected to the main housing 1 via the elastic element 5, and the safety switch 3 is electrically connected to the motor. When the handle housing 2 moves towards the main housing against the elastic force of the elastic element 5, the safety switch 3 is triggered to disconnect the motor.

[0030] During the operation of the electric circular saw 100, based on the relationship between action and reaction forces, the greater the resistance transmitted from the main housing 1 to the handle housing 2, the greater the thrust F applied by the user to the handle housing 2. Within the elastic force range of the elastic element 5, the resistance from the working head is buffered and absorbed by the elastic element 5 located between the main housing 1 and the handle housing 2, providing the user with a comfortable operating experience. When the thrust F applied to the handle housing 2 exceeds the elastic force of the elastic element 5, the handle housing 2 moves towards the main housing 1, triggering the safety switch 3, which promptly cuts off the motor's circuit, effectively protecting the motor and solving the problem of motor burnout due to overload caused by the lack of a controller, thus overcoming the shortcomings of the prior art.

[0031] The component F1 of the thrust F applied to the handle housing 2 in the cutting direction is greater than or equal to the sum of the frictional force on the circular saw 100 and the resistance experienced by the working head during operation. The circular saw 100 is equipped with a guide plate. During the cutting process, the guide plate and the workpiece experience static friction and sliding friction along the cutting direction. In this embodiment, the working head is a saw blade, and the saw blade also experiences resistance from the workpiece when cutting. Besides friction and resistance, the circular saw 100 may also experience other forces in the cutting direction. Only when the component F1 of the force F between the support and the handle housing 2 in the cutting direction is not less than the sum of the aforementioned forces can the circular saw 100 move forward normally and perform the cutting operation.

[0032] See Figure 1 As shown, the safety switch 3 has a trigger part 31 that can be pressed and activated. The main housing 1 has an actuating member 14 facing the trigger part 31. The elastic force of the elastic member 5 causes the handle housing 2 to move the safety switch 3 away from the actuating member 14. When the handle housing 2 moves towards the main housing 1 against the elastic force of the elastic member 5, the trigger part 31 presses against the actuating member 14, thus activating the safety switch 3. When the pushing force F acting on the handle housing 2 is greater than the elastic force of the elastic member 5, the trigger part 31 presses against the actuating member 14, at which point the safety switch 3 is activated and the motor is disconnected.

[0033] See Figure 2 As shown, one end of the elastic element 5 is connected to the main housing 1 and the other end abuts against the safety switch 3, which is fixedly disposed within the handle housing 2. In this embodiment, the elastic element 5 is a compression spring. Of course, in other embodiments, the elastic element 5 can also be a tension spring, as long as the positional relationship between the tension spring and the main housing 1 and the safety switch 3 is adjusted accordingly.

[0034] The main housing 1 has a cavity 13 facing the handle housing 2, and the handle housing 2 has a receiving sleeve 51 corresponding to the cavity 13. The two ends of the elastic member 5 are respectively received in the cavity 13 and the receiving sleeve 51, so as to be pre-tightly placed between the handle housing 2 and the main housing 1. The compression spring has a tendency to extend towards the safety switch 3, causing the trigger part 31 to move away from the actuating member 14. The compression amount of the compression spring characterizes the magnitude of the thrust F applied to the handle housing 2, and also reflects the magnitude of the friction and cutting resistance experienced by the electric circular saw 100. While the compression spring is compressed by the thrust F applied to the handle housing 2, the safety switch 3 moves towards the actuating member 14. When F exceeds the elastic force of the compression spring, the trigger part 31 can press against the actuating member 14, thereby triggering the safety switch 3 and stopping the motor. After the motor stops, the user performs the corresponding fault checks and troubleshooting. Then the resistance disappears, and the thrust F applied to the handle housing 2 also disappears. The compression spring extends again under the action of elastic restoring force, causing the safety switch 3 to move away from the action member 14, and the motor can be reconnected to the control circuit.

[0035] The handle housing 2 is C-shaped and has a first end 21 and a second end 22. The first end 21 houses the safety switch 3 and is floatingly connected to the main housing 1. The second end 22 is pivotally connected to the main housing 1 around a pivot 12. The first end 21 of the C-shaped handle is floatingly connected to the main housing 1 via an elastic element 5, and the second end 22 is pivotally connected to the main housing 1 around the pivot 12, achieving a connection relationship that is both independent and dependent on the main housing 1. Through this connection relationship, when the saw blade is subjected to greater cutting resistance, the first end 21 of the handle housing 2 rotates away from the main housing 1 around the second end 22. When the resistance is transmitted from the main housing 1 to the handle housing 2, it is partially buffered or absorbed by the elastic element 5, thereby reducing the impact on the user and improving the user's operating comfort. The elastic restoring force of the elastic element 5 also allows the user to apply a combined force in the cutting direction and the base plate direction to the handle housing 2 without expending a lot of pushing force, thus making it easier for the user to perform the cutting operation of the electric circular saw 100.

[0036] In addition, the working head rotates around a rotating axis 11 to perform the cutting operation, and the pivot 12 is arranged parallel to the rotating axis 11. The parallel arrangement of the pivot 12 and the rotating axis 11 of the saw blade allows the handle housing 2 to quickly pivot when the saw blade encounters resistance, thereby buffering the impact and improving the user's grip comfort.

[0037] Combination Figure 1As shown, the first end 21 is tangent to the rotation surface of the working head along the extension direction of the elastic member 5, so that the thrust applied to the handle housing 2 is consistent with the extension direction of the elastic member 5 and acts on the main housing 1 without loss, thereby balancing the resistance experienced by the working head.

[0038] The handle housing 2 includes a grip portion 24, which is located between the first end 21 and the second end of the handle housing 2.

[0039] The power tool also includes a main switch disposed within the grip portion 24, the main switch being used to control the start and stop of the motor and being connected in series with the safety switch 3. The power tool also includes a trigger for operating the main switch, the trigger being rotatably at least partially exposed outside the handle housing 2.

[0040] See Figure 2 As shown, the handle housing 2 also includes a secondary handle 25 connected to the handle housing 2. The secondary handle 25 has a connecting portion 251 extending outward from the first end 21 and a grip 253 located at the free end of the connecting portion 251. The angle between the extending direction of the connecting portion 251 and the extension direction of the elastic member 5 is an acute angle. The secondary handle 25 is designed to allow users to hold the handle with both hands, improving the distribution of force, ensuring even force distribution on both hands, and enhancing grip comfort.

[0041] In summary, the power tool using the technical solution of this invention has a positive correlation between the thrust applied to the handle housing 2 and the resistance experienced by the working head. Therefore, when the machine is overloaded, the thrust applied to the handle housing 2 exceeds the elastic force of the elastic element, allowing the handle housing 2 to move towards the main housing 1 with the safety switch 3. This triggers the safety switch 3 in time, thereby disconnecting the motor and providing effective overload protection for the power tool. This solves the problem of motor burnout due to overload without a controller and overcomes the shortcomings of the prior art.

[0042] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many other alternatives to the power tools of this invention can be developed without departing from the principles and scope of the invention. The scope of protection of this invention is defined by the claims.

Claims

1. A power tool, comprising a housing, a motor located within the housing, and a working head driven by the motor, the housing comprising a main housing housing the motor and a handle housing connected to the main housing, the handle housing comprising a main switch for controlling the start and stop of the motor, the working head being at least partially exposed within the main housing; characterized in that: The power tool includes an elastic element connecting the handle housing and the main housing, and a safety switch located inside the handle housing. The handle housing is floatingly connected to the main housing via the elastic element. The safety switch is connected in series with the main switch and is electrically connected to the motor. When the handle housing moves towards the main housing against the elastic force of the elastic element, the safety switch is triggered and disconnects the motor.

2. The power tool according to claim 1, characterized in that: The safety switch is provided with a trigger part that can be pressed and activated, and the main housing is provided with an actuating member that is disposed toward the trigger part. The elastic force of the elastic member causes the handle housing to move the safety switch away from the actuating member. When the handle housing moves toward the main housing against the elastic force of the elastic member, the trigger part presses against the actuating member, thereby triggering the safety switch.

3. The power tool according to claim 2, characterized in that: One end of the elastic element is connected to the main housing and the other end is connected to the handle housing, and the safety switch is disposed adjacent to the elastic element.

4. The power tool according to claim 3, characterized in that: The main housing has a cavity that opens toward the handle housing, and the handle housing has a receiving sleeve corresponding to the cavity. The two ends of the elastic member are respectively housed in the cavity and the receiving sleeve, so as to be pre-tightly placed between the handle housing and the main housing.

5. The power tool according to claim 1, characterized in that: The handle housing is C-shaped and has a first end and a second end. The first end houses the safety switch and is floatingly connected to the main housing. The second end is pivotally connected to the main housing about a pivot axis.

6. The power tool according to claim 5, characterized in that: The working head rotates around a rotating axis to perform a cutting operation, and the pivot is arranged parallel to the rotating axis.

7. The power tool according to claim 5, characterized in that: The first end is tangent to the rotational surface of the working head along the extension direction of the elastic element.

8. The power tool according to claim 5, characterized in that: The handle housing includes a grip portion located between the first end and the second end.

9. The power tool according to claim 8, characterized in that: The power tool also includes a main switch located within the grip, the main switch being used to control the start and stop of the motor and being connected in series with the safety switch.

10. The power tool according to claim 8, characterized in that: The handle housing also includes a secondary handle connected to the handle housing. The secondary handle has a connecting portion extending outward from the first end and a grip located at the free end of the connecting portion. The angle between the extending direction of the connecting portion and the extension direction of the elastic member is an acute angle.

Images