Patent Description:
Power tools include hand-held power tools and benchtop power tools. Higher demands are placed on the flexibility of working conditions and the compactness of the hand-held power tools aimed at DIY enthusiasts and home users among the hand-held power tools.

In the related art, rotary hand-held power tools such as screwdrivers and drill tools are generally available in either a straight profile or an angular profile to adapt to different usage scenarios. In some cases where straight and angular tools must work together, both tools must be on hand for constant alternation. <CIT> discloses a power tool according to the preamble of claim <NUM>.

An object of the present application is to provide a power tool.

The present application adopts the technical solutions described below.

A power tool includes a main housing provided with an accommodation space; a drive mechanism at least partially accommodated in the accommodation space and including a motor; a working head including an output shaft, where the output shaft is driven by the drive mechanism to rotate about an output axis; and a connection assembly including an input portion connected to the drive mechanism and an output portion connected to the output shaft, where the connection assembly rotates the working head about a first axis relative to the main housing. The power tool includes a first transmission path, the first transmission path is a torque transmission path from the drive mechanism through the connection assembly to the output shaft, and when the working head rotates about the first axis relative to the main housing, components in the first transmission path are configured to be deformed or to be displaced along a direction of the first transmission path.

According to the invention the working head includes a limit position for making the working head move about the first axis to a limit, where when the working head is located at the limit position, the included angle α between an axis of the input portion and an axis of the output portion is less than or equal to <NUM> degrees.

In some examples, the working head includes a limit position for making the working head move about the first axis to a limit, where when the working head is located at the limit position, the included angle α between an axis of the input portion and an axis of the output portion is less than or equal to <NUM> degrees.

In some examples, the working head further includes a first position for making the axis of the input portion parallel to or coincident with the axis of the output portion.

In some examples, the limit position includes a first limit position for making the working head move along a first direction about the first axis to a limit, and the first limit position is located on a side of the first position.

In some examples, the limit position further includes a second limit position for making the working head move along a second direction opposite to the first direction about the first axis to a limit, and the first limit position and the second limit position are located on two sides of the first position.

In some examples, the ratio of the output torque of the output shaft when the working head is located at the limit position to the output torque of the output shaft when the working head is located at the first position is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, when the working head is located at the first position, the output torque of the output shaft is greater than or equal to <NUM> N m.

In some examples, the ratio of the distance L1 between the first axis and a front end of the output shaft to the maximum distance L between a rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, the drive mechanism includes a direct current power supply.

In some examples, the direct current power supply includes a battery and has a nominal voltage less than or equal to <NUM> V.

In some examples, the ratio of the length L2 of the direct current power supply to the maximum distance L between a rear end of the main housing and a front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, when the working head rotates about the first axis relative to the main housing, the connection assembly is allowed to deform.

In some examples, when the working head rotates about the first axis relative to the main housing, at least one of the drive mechanism, the input portion, the output portion, and the output shaft is allowed to be displaced along the direction of the first transmission path.

A power tool includes a main housing provided with an accommodation space; a drive mechanism at least partially accommodated in the accommodation space and including a direct current power supply and a motor; a working head including an output shaft, where the output shaft is driven by the drive mechanism to rotate about an output axis; and a connection assembly connecting the output shaft to the drive mechanism and including at least one connector, where the at least one connector provides at least two orthogonal rotational degrees of freedom to rotate the working head about a first axis relative to the main housing.

A power tool includes a main housing provided with an accommodation space; a drive mechanism at least partially accommodated in the accommodation space and including a direct current power supply and a motor; a working head including an output shaft, where the output shaft is driven by the drive mechanism to rotate about an output axis; and a connection assembly connecting the output shaft to the drive mechanism and including at least one connector, where the at least one connector provides at least two orthogonal rotational degrees of freedom to rotate the working head about a first axis relative to the main housing. The ratio of the distance L1 between the first axis and a front end of the output shaft to the maximum distance L between a rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, the ratio of the distance L1 between the first axis and the front end of the output shaft to the maximum distance L between the rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, the working head includes a limit position for making the working head move about the first axis to a limit, where when the working head is located at the limit position, the included angle α between an axis of the motor and an axis of the output shaft is less than or equal to <NUM> degrees.

In some examples, the direct current power supply includes a battery and has a nominal voltage less than or equal to <NUM> V, and the maximum output torque of the output shaft is greater than or equal to <NUM> N m.

In order that the preceding object, features, and advantages of the present application can be more apparent and easier to understand, examples of the present application are described below in detail in conjunction with drawings. Numerous specific details are set forth below to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other manners than those described herein, and those skilled in the art may make similar modifications without departing from the connotation of the present application. Therefore, the present application is not limited by the examples disclosed below.

In the description of the present application, the terms "joined", "connected", and "fixed" are to be understood in a broad sense unless otherwise expressly specified and limited. For example, the term "connected" may refer to "fixedly connected", "detachably connected", or integrated, may refer to "mechanically connected" or "electrically connected", or may refer to "connected directly", "connected indirectly through an intermediary", "connected inside two elements", or "interaction relations between two elements". For those of ordinary skill in the art, specific meanings of the preceding terms in the present application may be understood based on specific situations.

In the present application, unless otherwise expressly specified and limited, when a first feature is described as "on" or "below" a second feature, the first feature and the second feature may be in direct contact or be in contact via another feature between the two features instead of being in direct contact. Moreover, when the first feature is described as "on", "above", or "over" the second feature, the first feature is right on, above, or over the second feature or the first feature is obliquely on, above, or over the second feature, or the first feature is simply at a higher level than the second feature. When the first feature is described as "under", "below", or "underneath" the second feature, the first feature is right under, below, or underneath the second feature or the first feature is obliquely under, below, or underneath the second feature, or the first feature is simply at a lower level than the second feature.

The present application is described below in detail in conjunction with drawings and examples.

To describe technical solutions of the present application clearly, "upper side", "lower side", "left side", "right side", "front side", and "rear side" as shown in <FIG> are further defined.

As shown in <FIG>, a power tool <NUM> includes a working head <NUM>, a main housing <NUM>, and a drive mechanism <NUM>. The working head <NUM> may output power directly or may be connected to another work accessory to output power. According to the working mode or output power of the working head <NUM>, the power tool <NUM> may be a corresponding tool, such as a screwdriver, a drill, or a wrench. The working head <NUM> is connected to the main housing <NUM> and rotates about a first axis <NUM> relative to the main housing <NUM> under the action of an external force. The working head <NUM> is connected to the drive mechanism <NUM> and outputs power under the action of the drive mechanism <NUM>.

The working head <NUM> includes an output shaft <NUM>. The output shaft <NUM> is driven by the drive mechanism <NUM> to rotate about an output axis <NUM>. In this example, the screwdriver is used as an example, and a mounting groove <NUM> to which different bits are mounted is further formed at the end of the output shaft <NUM>. For example, the mounting groove <NUM> is a standard hexagonal groove. In other alternative examples, for example, the power tool is the wrench, and a mounting head for mounting a sleeve is formed at or connected to the end of the output shaft <NUM>. In other alternative examples, for example, the power tool is the drill, and a collet assembly for holding a drill bit is connected to the end of the output shaft <NUM>.

The main housing <NUM> includes a grip <NUM> and a connecting portion <NUM>, where the connecting portion <NUM> is formed at or connected to an end of the grip <NUM>, and the connecting portion <NUM> is used for connecting the working head <NUM>. In this example, the main housing <NUM> extends along a third axis <NUM> as a whole. The connecting portion <NUM> is located at the upper end of the main housing, that is to say, the working head <NUM> is connected to the upper end of the main housing <NUM>. The connecting portion <NUM> is formed with a first accommodation space. The grip <NUM> is disposed below the connecting portion. The grip <NUM> is formed with a second accommodation space, and the first accommodation space communicates with the second accommodation space. Most of the drive mechanism <NUM> is disposed in the second accommodation space formed by the grip <NUM>. It is to be understood that the main housing <NUM> is substantially in the shape of a straight tube.

As shown in <FIG>, the drive mechanism <NUM> includes a motor <NUM> and a direct current power supply <NUM>. In this example, the motor <NUM> includes a drive shaft rotatable about a drive axis. In this example, the drive axis coincides with the third axis <NUM>. In other alternative examples, the drive axis and the third axis <NUM> are parallel to each other but do not coincide. In other alternative examples, a certain included angle exists between the drive axis and the third axis <NUM>. In this example, the motor <NUM> is specifically an electric motor, and the electric motor <NUM> is used below instead of the motor in the subsequent description, but it does not serve as a limitation of the present invention.

In this example, the direct current power supply <NUM> is specifically a battery or a battery pack. The battery or the battery pack mates with a corresponding power circuit to supply power to the power tool <NUM>. Those skilled in the art should understand that the battery is a built-in rechargeable battery or a replaceable standard battery. The direct current power supply <NUM> may also be the battery pack. In some examples, the direct current power supply <NUM> includes one battery. In some examples, the direct current power supply includes multiple batteries. It is to be understood that the number of cells in each battery varies with the nominal voltage and capacity of the battery, which does not limit the substantive content of the present application. In this example, the direct current power supply <NUM> has a nominal voltage less than or equal to <NUM> V. In this example, the direct current power supply has a nominal voltage less than or equal to <NUM> V.

In this example, the diameter of the grip is basically the same. In some examples, to increase the amount of power stored in the direct current power supply <NUM> to prolong the service life thereof, the width of the grip <NUM> at the corresponding position of the direct current power supply <NUM> increases.

A charging interface may be provided near the end of the main housing <NUM>, such as one or more of a universal serial bus (USB) interface, a Type-C interface, and a lighting interface. In this example, the charging interface <NUM> is disposed at the bottom. The direct current power supply <NUM> is electrically connected to the charging interface <NUM>. In some examples, the direct current power supply <NUM> is the rechargeable battery removable from the grip <NUM>. The power tool is not limited to only using the direct current power supply <NUM> for power supply. With the corresponding rectification, filtering, and voltage regulation circuits, the power tool can be powered by not only the direct current power supply but also the alternating current power.

As shown in <FIG> and <FIG> and <FIG>, the working head <NUM> further includes a moving portion <NUM> and an output shaft housing <NUM>. The moving portion <NUM> is formed on or connected to the output shaft housing <NUM>. The output shaft housing <NUM> is wrapped around the outer circumference of the output shaft <NUM>. When the output shaft <NUM> rotates about the output axis <NUM>, the output shaft housing <NUM> basically does not rotate with the output shaft <NUM>.

The moving portion <NUM> is connected to the main housing <NUM>. In this example, the moving portion <NUM> is movably connected to the connecting portion <NUM> or is disposed in the first accommodation space. When the working head <NUM> rotates about the first axis <NUM> relative to the main housing <NUM>, the moving portion <NUM> rotates with the working head <NUM> about the first axis <NUM>. The connecting portion <NUM> on the main housing <NUM> is provided with a rotation groove <NUM>, the output shaft <NUM> protrudes from the rotation groove <NUM>, and the moving portion <NUM> is limited in the rotation groove <NUM>. The connecting portion <NUM> includes an arc-shaped or arc-like guide portion, and the working head <NUM> moves along the guide portion. In some examples, the rotation groove <NUM> may be a closed groove body formed with a space in which the moving portion <NUM> is placed. In some examples, the rotation groove <NUM> may be an open groove and has a limiting portion for limiting the movement of the moving portion <NUM>. The limiting portion is provided so that the rotation groove <NUM> is formed with a limiting groove with an opening in the first accommodation space. The output shaft <NUM> protrudes from the rotation groove <NUM>, and the outer diameter of an end of the output shaft <NUM> connected to the moving portion <NUM> is approximately equal to the width of the rotation groove so that the end is engaged with the rotation groove <NUM>. The rotation groove <NUM> is disposed on a circumferential side (that is, a side around the first axis <NUM>) of the connecting portion <NUM>. In this example, the circumferential side of the connecting portion <NUM> is a curved surface, and the moving portion <NUM> is a curved surface having a shape corresponding to the circumferential side of the connecting portion. The surface of the moving portion <NUM> fits the inner surface of the connecting portion <NUM> so that the moving portion <NUM> is movable along the rotation groove <NUM> on the connecting portion <NUM>.

As shown in <FIG>, in this example, the power tool <NUM> further includes a connection assembly <NUM>. The connection assembly <NUM> rotates the working head <NUM> about the first axis <NUM> relative to the main housing <NUM>. The connection assembly <NUM> transmits the torque outputted by the drive mechanism <NUM> to the output shaft <NUM>. The power tool <NUM> includes a first transmission path. The first transmission path is a torque transmission path from the drive mechanism <NUM> through the connection assembly <NUM> to the output shaft <NUM>. In this example, after the electric motor <NUM> is powered on, the drive shaft of the electric motor <NUM> rotates to generate torque. The drive mechanism <NUM> transmits the torque to the output shaft <NUM> through the connection assembly <NUM>. The output shaft <NUM> outputs torque and the torque acts on a fastener, thereby forming a torque transmission path from the drive mechanism <NUM> through the connection assembly <NUM> to the output shaft <NUM>, that is, the first transmission path. It is to be understood that when the working head <NUM> rotates about the first axis <NUM> relative to the main housing <NUM>, an axis P of the first transmission path changes with the rotation of the working head <NUM>, that is, the rotation of the output shaft <NUM>. That is, the starting point of the axis P of the first transmission path is the electric motor <NUM>, and the end point of the axis P passes through the output shaft <NUM>. Therefore, the axis P of the first transmission path is a curve or a straight line from the electric motor <NUM> through the connection assembly <NUM> to the output shaft <NUM>. The direction of the first transmission path is from the starting point to the end point of the axis P of the first transmission path.

The connection assembly <NUM> includes an input portion 50a connected to the drive mechanism <NUM> and an output portion 50b connected to the output shaft <NUM>. The input portion 50a and the output portion 50b are two independent components connected to each other or different parts of the same component. When the working head <NUM> rotates about the first axis <NUM> relative to the main housing <NUM>, the components in the first transmission path are allowed to deform or to be displaced along the direction of the first transmission path. That is to say, the component group in the first transmission path includes at least one component that is or includes a flexible structure, or at least two components in the component group in the first transmission path are in a floating connection. In this manner, when the working head <NUM> rotates about the first axis <NUM>, the axis P of the first transmission path may bend or change in angle, thereby releasing the axial limit of the components in the first transmission path. In this example, the input portion 50a and the output portion 50b are independent components connected to each other. When the working head <NUM> rotates about the first axis <NUM> relative to the main housing <NUM>, at least one of the drive mechanism <NUM>, the input portion 50a, the output portion 50b, and the output shaft <NUM> is allowed to be displaced along the direction of the first transmission path. In some examples, the input portion 50a and the output portion 50b are different parts of the same component, for example, this component may be a flexible cable or a flexible shaft. When the working head <NUM> rotates about the first axis <NUM> relative to the main housing <NUM>, the connection assembly <NUM> is allowed to deform.

As an example of the present application, the connection assembly <NUM> includes a universal joint 50c. In this example, the universal joint 50c includes a first universal joint <NUM> and a second universal joint <NUM> connected to each other, that is, the universal joint 50c may be a duplex universal joint. The first universal joint <NUM> may provide at least two orthogonal rotational degrees of freedom. The second universal joint <NUM> may provide at least two orthogonal rotational degrees of freedom.

The first universal joint <NUM> is used as an example for the description of the specific structure. The first universal joint <NUM> includes a first input portion <NUM>, a first output portion <NUM>, and a first holding portion <NUM>. The first holding portion <NUM> connects the first input portion <NUM> to the first output portion <NUM>. In this example, the first holding portion <NUM> is a spherical retaining frame composed of a spherical base <NUM> and a corresponding ball head <NUM>. Any one of the first input portion <NUM> and the first output portion <NUM> forms or is connected to the spherical base <NUM>, and the other one of the first input portion <NUM> and the first output portion <NUM> forms or is connected to the ball head <NUM>. In this example, the drive mechanism <NUM> is connected to an end of the first input portion <NUM>, and the spherical base <NUM> is formed at the other end of the first input portion <NUM>. The ball head <NUM> is formed at an end of the first output portion <NUM>, and the second universal joint <NUM> is connected to the other end of the first output portion <NUM>. Rolling balls are disposed in the ball head <NUM> to keep the ball head <NUM> in the spherical base <NUM> and enable the first universal joint <NUM> to achieve variable-angle power transmission. The dimension of part of the first input portion <NUM>, the first output portion <NUM>, and the first holding portion <NUM> with the largest radial dimension is defined as the maximum radial dimension R1 of the first universal joint <NUM>. In this example, the diameter of the spherical base <NUM> is the maximum radial dimension R1 of the first universal joint <NUM>. The ratio of the maximum radial dimension R1 of the first universal joint <NUM> to the outer diameter dimension R2 of the electric motor <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>. It is to be explained that when the electric motor <NUM> is an inrunner motor, the outer diameter of the electric motor <NUM> is the diameter of stator laminations. When the electric motor <NUM> is an outrunner motor, the outer diameter of the electric motor <NUM> is the diameter of a rotor sleeve. In some examples, the ratio of the maximum radial dimension R1 of the first universal joint <NUM> to the outer diameter dimension R2 of the electric motor <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the maximum radial dimension R1 of the first universal joint <NUM> to the outer diameter dimension R2 of the electric motor <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the maximum radial dimension R1 of the first universal joint <NUM> to the outer diameter dimension R2 of the electric motor <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>.

In this example, the ball head <NUM> forms a floating connection with the spherical base <NUM>. When the working head <NUM> rotates around the first axis <NUM> relative to the main housing <NUM>, the ball head <NUM> floats relative to the spherical base <NUM>, that is to say, there is a gap between the ball head <NUM> and the spherical base <NUM> so that the ball head <NUM> can move relative to the spherical base <NUM> in the direction of the first transmission path. The ball head <NUM> can be understood as a part in the first transmission path that can be displaced along the direction of the first transmission path.

As can be seen from the related art, the outer diameter of the electric motor affects the performance of the electric motor. In the first transmission path, the connection assembly <NUM> needs to ensure sufficient strength so that the torque can be transmitted to the output shaft <NUM>. In this manner, breaking or unspecified deformation of the connection assembly can be avoided during torque transmission. The increase of the diameter or volume of the connection assembly <NUM> improves the strength of the connection assembly, but the feel of the product are affected and the cost of the product is increased. Therefore, a relatively balanced and proper relationship is required between the connection assembly <NUM> and the electric motor <NUM>. The ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the electric motor <NUM> is defined to be greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the electric motor <NUM> is defined to be greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the maximum radial dimension R1 of the first universal joint to the outer diameter dimension R2 of the electric motor <NUM> is defined to be greater than or equal to <NUM> and less than or equal to <NUM> so that the strength of the connection assembly <NUM> can be ensured during torque transmission. The overall compactness of the power tool is improved, providing a better use effect.

In some alternative examples, the number of universal joints included in the connection assembly is not limited. The number of universal joints may be one or more than two, which does not limit the substantive content of the present application.

In some alternative examples, the first universal joint <NUM> is a cross shaft universal joint. The first holding portion is a cross shaft part connecting the first input portion to the first output portion. The diameter of the first holding portion is the diameter of the smallest circle enclosing the cross shaft part.

In this example, the first universal joint <NUM> and the second universal joint <NUM> are spherical universal joints with the same structure. In some examples, the first universal joint and the second universal joint may have the same structure but different dimensions. In some examples, the first universal joint and the second universal joint may have different structures and different dimensions. It is to be understood that when the universal joint 50c includes two or more single universal joints, the maximum radial dimension R1 of the universal joint 50c is the maximum value among the radial dimensions of the input portion, the output portion, and the holding portion of each single universal joint in the universal joint 50c.

In this example, the connection assembly <NUM> further includes an intermediate piece <NUM>. The intermediate piece <NUM> is used for displaying the logo or special appearance of the product, a product shape, or product information. For example, the intermediate piece <NUM> is used for indicating the rotational angle of the working head <NUM> about the first axis <NUM> or the rotational speed of the output shaft <NUM>. In some examples, a state display unit is disposed on the intermediate piece <NUM>. The state display unit includes a liquid crystal display (LCD)/light-emitting diode (LED) display screen, a buzzer, a component like a light-emitting diode, or another component with a prompt function, and the state display unit is used for performing a state display or giving a prompt when the power tool has an abnormal working state or a low battery. A specific prompt mode varies with the definition and requirement of the product. It is to be understood that the specific prompt mode has been fully disclosed to those skilled in the art. It is to be understood that the intermediate piece does not belong to the components of the universal joint 50c, and the dimension of the intermediate piece does not belong to the dimension of the universal joint 50c.

As shown in <FIG>, the working head <NUM> includes a limit position and a first position. The limit position is a position for making the working head <NUM> move about the first axis <NUM> to the limit, and the first position is a position for making the axis of the input portion 50a parallel to or coincident with the axis of the output portion 50b. In this example, the axis of the input portion 50a coincides with the drive axis of the electric motor <NUM> and the third axis <NUM>. The axis of the output portion 50b coincides with the output axis <NUM> of the output shaft <NUM>. As shown in <FIG>, when the working head <NUM> is at the first position, the third axis <NUM> coincides with the output axis <NUM>. The included angle α between the axis of the input portion 50a, that is, the third axis <NUM> and the axis of the output portion 50b, that is, the output axis <NUM>, is <NUM> degrees. As shown in <FIG>, when the working head <NUM> is at the limit position, the included angle α between the axis of the input portion 50a, that is, the third axis <NUM> and the axis of the output portion 50b, that is, the output axis <NUM>, is less than or equal to <NUM> degrees. In some examples, when the working head <NUM> is at the limit position, α is less than or equal to <NUM> degrees, <NUM> degrees, or <NUM> degrees. The included angle α between the axis of the input portion 50a, that is, the third axis <NUM> and the axis of the output portion 50b, that is, the output axis <NUM>, when the working head <NUM> is at the limit position is limited so that the output torque of the output shaft <NUM> is ensured, and the torque transmission efficiency of the connection assembly is ensured. When the working head <NUM> is at the first position, the connection assembly <NUM> has the maximum torque transmission efficiency. The torque transmission efficiency of the connection assembly <NUM> when the working head <NUM> is at the limit position is lower than the torque transmission efficiency of the connection assembly <NUM> when the working head <NUM> is at the first position. In this example, at the limit position, the included angle α between the axis of the input portion 50a, that is, the third axis <NUM>, and the axis of the output portion 50b, that is, the output axis <NUM>, is less than or equal to <NUM> degrees so that the ratio of the output torque of the output shaft <NUM> when the working head <NUM> is at the limit position to the output torque of the output shaft <NUM> when the working head <NUM> is at the first position is greater than or equal to <NUM> and less than or equal to <NUM>, thereby ensuring the torque transmission efficiency of the connection assembly. In some examples, the ratio of the output torque of the output shaft <NUM> when the working head <NUM> is located at the limit position to the output torque of the output shaft <NUM> when the working head <NUM> is located at the first position is greater than or equal to <NUM> and less than or equal to <NUM>. In this example, when the working head <NUM> is located at the first position, the output torque of the output shaft <NUM> is greater than or equal to <NUM> N·m.

In this example, the limit position includes a first limit position for making the working head <NUM> move along a first direction about the first axis <NUM> to the limit. Multiple positions for locking the working head <NUM> may further be included between the first position and the first limit position. As shown in <FIG> and <FIG>, the power tool <NUM> further includes a positioning assembly <NUM>. The positioning assembly <NUM> is used for positioning the rotational position of the working head <NUM> about the first axis <NUM> relative to the main housing <NUM>. The positioning assembly <NUM> is disposed between the moving portion <NUM> and the connecting portion <NUM> and couples the moving portion <NUM> to the connecting portion <NUM> to stop the working head <NUM> at a set position.

The positioning assembly <NUM> includes a base <NUM>, a positioning member <NUM>, and a positioning groove <NUM>. Multiple positioning grooves <NUM> are provided. The multiple positioning grooves <NUM> are disposed on the inner side of the connecting portion <NUM>. In this example, multiple angle indicators <NUM> are disposed on the outer side of the connecting portion <NUM>, that is, a side observable by the user. The number of the angle indicators <NUM> is the same as the number of the positioning grooves <NUM>. The base <NUM> is disposed on the working head <NUM>. In this example, the base <NUM> is disposed on the output shaft housing <NUM>. The base <NUM> extends along the direction of the first axis <NUM>. The positioning member <NUM> connects the moving portion <NUM> to the connecting portion <NUM>. An end of the positioning member <NUM> is connected to the base <NUM>, and the other end of the positioning member <NUM> is clutchably connected to the positioning groove <NUM>. The positioning member <NUM> is movable in the base <NUM> relative to the moving portion <NUM>. The movement of the positioning member <NUM> is caused by the rotation of the working head <NUM> about the direction of the first axis <NUM>, and the shape of the multiple positioning grooves <NUM> corresponds to the shape of the positioning member <NUM>. The positioning groove <NUM> is connected to the positioning member <NUM> to position the working head <NUM>. The position of each positioning groove <NUM> corresponds to a different rotational angle of the working head <NUM>.

When the working head <NUM> rotates from a certain angle to another angle, the positioning member <NUM> moves from a corresponding positioning groove <NUM> into the the base <NUM> and then moves from the base <NUM> to another positioning groove <NUM>. In this example, the positioning member <NUM> includes a rolling ball <NUM> and a telescopic member <NUM>. When the working head <NUM> rotates, the rolling ball <NUM> moves in an adjacent positioning groove <NUM> to a groove wall and is then pressed by the groove wall, and the rolling ball <NUM> biases the telescopic member <NUM>. When the rolling ball <NUM> enters one positioning groove <NUM>, the telescopic member <NUM> supports the rolling ball <NUM> to keep the rolling ball <NUM> in the positioning groove <NUM>.

As shown in <FIG>, the power tool <NUM> further includes a locking assembly <NUM> for positioning the rotational position of the working head <NUM> about the first axis <NUM> relative to the main housing <NUM>. It is to be understood that the limiting force provided by the positioning assembly <NUM> is not enough to ensure that the working head <NUM> and the main housing <NUM> do not move relative to each other during operation. That is to say, when the positioning assembly <NUM> completes the positioning, the relative motion between the working head <NUM> and the main housing <NUM> can be restricted, but when the torque output work is performed, the positioning state of the positioning assembly <NUM> is easily destroyed. The locking assembly <NUM> can provide a locking force sufficient to keep the working head <NUM> and the main housing <NUM> in a relatively locked state stably during operation.

The locking assembly <NUM> includes first teeth <NUM>, second teeth <NUM>, and a trigger <NUM>. The first teeth <NUM> and the second teeth <NUM> are engaged with each other. The first teeth <NUM> are formed around the circumferential direction of the working head <NUM>. In this example, the first teeth <NUM> are disposed on the output shaft housing <NUM> and are disposed on the outer circumference of a first through hole <NUM>. The trigger <NUM> is partially disposed outside the main housing <NUM> and is used for the user to trigger. The trigger <NUM> is connected to the second teeth <NUM>. The trigger <NUM> includes a locked position and an unlocked position, where when the trigger <NUM> is at the locked position, the first teeth <NUM> and the second teeth <NUM> are engaged with each other. When the trigger member <NUM> is triggered to move to the unlocked position, the second teeth <NUM> are displaced and disengaged from the first teeth <NUM>, and at this time, the working head <NUM> can rotate about the first axis <NUM> relative to the main housing <NUM>. The trigger <NUM> is disposed on the same side as a torque regulation operating member <NUM> and a switching operating member. The trigger <NUM> is located at the upper position of the grip. The trigger <NUM> is disposed at a position where the thumb can operate when the palm of the user holds the grip.

In this example, the locking assembly <NUM> further includes a biasing element <NUM> connected to the trigger <NUM>. The biasing element <NUM> provides a biasing force to move the trigger <NUM> from the unlocked position to the locked position, that is, a biasing force to move the second teeth <NUM> toward the first teeth <NUM>. It is to be understood that the number of the positioning grooves <NUM> in the positioning assembly <NUM> corresponds to the number of the first teeth <NUM>.

In some examples, the limit position includes a second limit position for making the working head <NUM> move along a second direction about the first axis <NUM> to the limit. The first limit position and the second limit position are located on two sides of the first position. The first position is an intermediate position, the first limit position is in front of the first position, and the second limit position is behind the first position. The second limit position and the first limit position may be arranged symmetrically with respect to the first position, or the second limit position may be closer to the first position than the first limit position.

As shown in <FIG>, the drive mechanism <NUM> further includes a transmission assembly <NUM>. The transmission assembly <NUM>, the electric motor <NUM>, and the direct current power supply <NUM> are connected from top to bottom in sequence. In this example, the transmission assembly <NUM>, the electric motor <NUM>, and the direct current power supply <NUM> are disposed in the second accommodation space, or at least most of the transmission assembly <NUM>, the electric motor <NUM>, and the direct current power supply <NUM> are disposed in the second accommodation space.

The transmission assembly <NUM> is used for transmitting power outputted by the electric motor <NUM> to the output shaft <NUM>. The transmission assembly <NUM> is disposed between the output shaft <NUM> and the electric motor <NUM>, and the transmission assembly <NUM> is at least partially or entirely disposed in the grip <NUM> and may be at least partially disposed in the connecting portion <NUM>. In this example, the transmission assembly <NUM> adopts a planet gear deceleration mechanism. The transmission assembly <NUM> includes a planetary gearset <NUM> of three stages or more than three stages and a gearbox housing <NUM>. An internal tooth structure is disposed on the inner side of the gearbox housing <NUM>. Since the working principle of the planet gear deceleration mechanism and the principle of deceleration generated by the transmission assembly or the speed regulation principle of the planet gear have been fully disclosed to those skilled in the art, a detailed description is omitted herein for the brevity of the description.

As shown in <FIG> and <FIG>, the distance between the rear end of the main housing and the front end of the output shaft when the working head <NUM> is at the first position is defined as the maximum distance L. The distance between the first axis <NUM> and the front end of the output shaft <NUM> is L1. It is to be explained that in this example, a clamping portion for clamping the accessory is formed on a shaft body of the output shaft, and the front end of the output shaft is the front end of the shaft body. In some examples, the output shaft includes the shaft body and the clamping portion, the clamping portion is fixedly connected to the shaft body, and the front end of the output shaft is the frontmost part of the shaft body and the clamping portion. In some examples, the output shaft includes the shaft body and the clamping portion, and the clamping portion is detachably connected to the shaft body. That is to say, after the clamping portion of the power tool is detached, when the shaft body can still drive the accessory to work, the front end of the output shaft is the front end of the shaft body. In this example, the ratio of the distance L1 between the first axis <NUM> and the front end of the output shaft <NUM> to the maximum distance L is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the distance L1 between the first axis and the front end of the output shaft to the maximum distance L is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, the ratio of the distance L1 between the first axis and the front end of the output shaft to the maximum distance L is greater than or equal to <NUM> and less than or equal to <NUM> so that the working head is more suitable for a narrow space. In this example, the distance L1 between the first axis and the front end of the output shaft is less than or equal to <NUM>. In some examples, the distance L1 between the first axis and the front end of the output shaft is less than or equal to <NUM>. In some examples, the distance L1 between the first axis and the front end of the output shaft is less than or equal to <NUM>. In some examples, the distance L1 between the first axis and the front end of the output shaft is less than or equal to <NUM>.

In some examples, the distance L3 between the first axis <NUM> and the rear end of the main housing is less than or equal to <NUM>. In some examples, the distance L3 between the first axis <NUM> and the rear end of the main housing is less than or equal to <NUM>. In some examples, the distance L3 between the first axis <NUM> and the rear end of the main housing is less than or equal to <NUM>.

In this example, the direct current power supply <NUM> is built in the main housing. When the working head <NUM> is at the first position, the ratio of the length L2 of the direct current power supply <NUM> to the maximum distance L between the rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, when the working head <NUM> is at the first position, the ratio of the length L2 of the direct current power supply <NUM> to the maximum distance L between the rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM>. In some examples, when the working head <NUM> is at the first position, the ratio of the length L2 of the direct current power supply <NUM> to the maximum distance L between the rear end of the main housing and the front end of the output shaft is greater than or equal to <NUM> and less than or equal to <NUM> so that the whole power tool is compact. The length L2 of the direct current power supply <NUM> is the length of the battery or battery pack of the direct current power supply <NUM> along the direction of the third axis <NUM>. In this example, the weight of the power tool is less than or equal to <NUM>. In some examples, the direct current power supply <NUM> is a battery pack, the battery pack is detachably mounted in the main housing, and the direct current power supply <NUM> is partially mounted in the main housing. In this case, the length L2 of the direct current power supply <NUM> is the length of the battery pack.

As shown in <FIG> and <FIG> and <FIG>, a window portion <NUM> is disposed in the main housing <NUM> and used for displaying the internal structure of the power tool <NUM>. In this example, the window portion <NUM> is disposed on the connecting portion <NUM>, and the position of the window portion <NUM> is opposite to the position of the connection assembly <NUM> so that part of the structure of the connection assembly <NUM> is displayed in the window portion.

As shown in <FIG>, the power tool <NUM> further includes a switch assembly including at least two switches that are used for controlling different functions of the electric motor and a controller. The switch assembly includes operating members and corresponding switch elements. The operating members include a main switch operating member <NUM>, the torque regulation operating member <NUM>, and the switching operating member. The main switch operating member <NUM> corresponds to a main switch and is used for controlling the start and stop of the electric motor <NUM>. The torque regulation operating member <NUM> and the switching operating member send different signals to the controller to control the output torque of the output shaft <NUM> and switch a forward rotation state and a reverse rotation state of the electric motor <NUM>. The main switch operating member <NUM> is disposed at the joint of the grip <NUM> and the connecting portion <NUM>. In this example, the main switch operating member <NUM> is disposed on a side adjacent to the window portion <NUM>. The switching operating member is coupled to the main switch operating member <NUM>. The torque regulation operating member <NUM> is disposed on the grip <NUM>. In some examples, the torque regulation operating member <NUM> is disposed near the lower end of the grip <NUM>. The torque regulation operating member <NUM> is disposed on the same side as the window portion <NUM>. That is to say, the main switch operating member <NUM> and the torque regulation operating member <NUM> are disposed on adjacent sides. It is to be understood that the main switch operating member <NUM> and the torque regulation operating member <NUM> are staggered at an angle on the main housing <NUM> around the third axis <NUM>. In this example, a torque indicator light <NUM> is disposed near the torque regulation operating member <NUM>. Different display states of the torque indicator light <NUM> indicate different output torque. The torque indicator light <NUM> and the torque regulation operating member <NUM> are disposed on the same side of the grip <NUM>. In other alternative examples, the switching operating member and the main switch operating member <NUM> are disposed independently and disposed on the same side of the grip <NUM>.

In this example, the torque regulation operating member <NUM> is integrated with a locking function, or a lock is disposed near the torque regulation operating member <NUM>. That is, the lock can control the connection and disconnection of the electrical connection between the electric motor and the direct current power supply.

The controller is disposed on a control circuit board <NUM>. The control circuit board <NUM> includes a printed circuit board (PCB) and a flexible printed circuit (FPC) board. The controller uses a dedicated control chip, for example, a single-chip microcomputer and a microcontroller unit (MCU).

The operating members are connected to the corresponding switches. The switches are electrically connected to the controller. According to different signals sent by the switches, the controller performs corresponding control actions on the electric motor.

The control circuit board <NUM> is electrically connected to the drive mechanism <NUM>. The control circuit board <NUM> is disposed in the grip <NUM> and is parallel or basically parallel to the drive mechanism <NUM> or the third axis <NUM>. Being basically parallel refers to the case where the included angle between the control circuit board <NUM> and the drive mechanism <NUM> or the third axis <NUM> is less than or equal to <NUM> degrees.

As shown in <FIG>, the power tool <NUM> further includes a lighting assembly <NUM>. The lighting assembly <NUM> is disposed on the working head <NUM> and provides light for illuminating a working region. The lighting assembly <NUM> rotates with the working head <NUM> about the first axis <NUM> and always provides light for illuminating the working position of the output shaft <NUM>. The lighting assembly <NUM> includes a lighting element for emitting light, and the lighting element is disposed in the output shaft housing <NUM> and located on a side of the output shaft <NUM>. In other alternative examples, the lighting element is disposed around the output shaft.

As shown in <FIG>, in this example, the connecting portion <NUM> includes a left connecting portion <NUM> and a right connecting portion <NUM> that are assembled with each other. The right connecting portion <NUM> is integrally formed with the grip <NUM>. That is to say, the basically cylindrical grip <NUM> is integrally formed with the right connecting portion <NUM>. The left connecting portion <NUM> is detachably connected to the right connecting portion <NUM>, so as to increase the strength of the main housing <NUM>. The bottom of the main housing <NUM> further includes a lower cover <NUM> connected to the lower opening of the right connecting portion <NUM>. The charging interface <NUM> is disposed on the lower cover <NUM>.

Claim 1:
A power tool (<NUM>), comprising:
a main housing (<NUM>) provided with an accommodation space;
a drive mechanism at least partially accommodated in the accommodation space and comprising a motor (<NUM>);
a working head (<NUM>) comprising an output shaft (<NUM>), wherein the output shaft (<NUM>) is driven by the drive mechanism to rotate about an output axis (<NUM>); and
a connection assembly (<NUM>) comprising an input portion (50a) connected to the drive mechanism and an output portion (50b) connected to the output shaft (<NUM>), wherein the connection assembly (<NUM>) rotates the working head (<NUM>) around a first axis (<NUM>) relative to the main housing (<NUM>);
wherein the power tool (<NUM>) comprises a first transmission path, the first transmission path is a torque transmission path from the drive mechanism through the connection assembly (<NUM>) to the output shaft (<NUM>), and at least a component in the first transmission path are configured to be deformed or to be displaced along a direction of the first transmission path when the working head (<NUM>) rotates about the first axis (<NUM>) relative to the main housing (<NUM>); characterized in that
the working head (<NUM>) comprises a limit position where the working head (<NUM>) moves to a limit around the first axis (<NUM>), and an included angle α between an axis of the input portion (50a) and an axis of the output portion (50b) is less than or equal to <NUM> degrees when the working head (<NUM>) is located at the limit position.