Impact tool

An impact tool includes a switch for driving the tool accessory, an operation member configured to be movable between an OFF position and an ON position, a first lock member configured to lock the operation member in the ON position, a second lock member configured to be movable between a lock position and a lock-release position in response to an external operation by a user, and a holding mechanism configured to hold the second lock member in the lock position and also in the lock-release position. The second lock member in the lock position is capable of locking the operation member in the OFF position, and the second lock member in the lock-release position is incapable of locking the operation member in the OFF position.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priorities to Japanese patent application No. 2018-093330 filed on May 14, 2018, and Japanese patent application No. 2018-179038 filed on Sep. 25, 2018. The contents of the foregoing applications are fully incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an impact tool configured to only linearly drive a tool accessory.

BACKGROUND ART

An impact tool (such as an electric hammer (also called as a scraper)) is known which is configured to perform a chipping operation or a scraping operation only by linearly driving a tool accessory. Such an impact tool may include a lock mechanism which is configured to lock an operation member for a switch for driving a tool accessory in a position in which the operation member places the switch in an ON state (see Japanese laid-open patent publication No. 2008-119755, for example).

SUMMARY

Such an impact tool having a lock mechanism as described above eliminates the need for a user to keep pressing the operation member during the chipping or scraping operation so that the convenience is improved. Such an impact tool is, however, desired to further improve the convenience.

It is, accordingly, an object of the present disclosure to provide a technique which helps improve convenience in an impact tool configured to only linearly drive a tool accessory.

According to one aspect of the present disclosure, an impact tool is provided which is configured to only linearly drive a tool accessory along a drive axis extending in a front-rear direction. The impact tool includes a switch, an operation member, a first lock member, a second lock member and a holding mechanism. The switch is for driving the tool accessory. The operation member is configured to be movable between an OFF position and an ON position. The operation member in the OFF position holds the switch in an OFF state, and the operation member in the ON position holds the switch in an ON state. The first lock member is configured to lock the operation member in the ON position. The second lock member is configured to be movable between a lock position and a lock-release position, in response to an external operation by a user. The second lock member in the lock position is capable of locking the operation member in the OFF position. The second lock member in the lock-release position is incapable of locking the operation member in the OFF position. The holding mechanism is configured to hold the second lock member in the lock position and also in the lock-release position.

In one aspect of the present disclosure, the impact tool may further include a grip part extending in an up-down direction orthogonal to the drive axis. The operation member may be provided on the grip part, and the second lock member may be disposed on an upper side of the grip part.

In one aspect of the present disclosure, the second lock member may be movable between the lock position and the lock-release position in a direction crossing a moving direction of the operation member.

In one aspect of the present disclosure, the holding mechanism may include a biasing member. Further, the holding mechanism may be configured to hold the second lock member in the lock position and also in the lock-release position by a biasing force of the biasing member.

In one aspect of the present disclosure, both end portions of the second lock member in a moving direction of the second lock member may be disposed to be externally operated by a user. Further, the end portions of the second lock member may have different structures.

In one aspect of the present disclosure, a single lock member may be configured to serve both as the first lock member and the second lock member. In other words, the single lock member may have both the function of locking the operation member in the ON position and the function of locking the operation member in the OFF position.

In one aspect of the present disclosure, the lock member may be capable of locking the operation member both in the ON position and in the OFF position when the lock member is in the lock position. Further, the lock member may be configured to allow the operation member to move between the OFF position and the ON position when the lock member is in the lock-release position.

In one aspect of the present disclosure, the operation member may include a first interference part, and the lock member may include a second interference part. The second interference part may be configured to be placed on a moving path of the first interference part when the lock member is in the lock position to thereby lock the operation member in the ON position or in the OFF position by interfering with the first interference part. The second interference part may have an outer surface which includes opposed first and second surfaces arranged to cross a moving direction of the operation member. The first surface which is arranged on the ON position side of the second interference part in the moving direction may be configured to lock the operation member in the ON position by abutting on the first interference part. Further, the second surface which is arranged on the OFF position side of the second interference part in the moving direction may be configured to lock the operation member in the OFF position by abutting on the first interference part. It is noted that the terms “the ON position side in the moving direction” and “the OFF position side in the moving direction” may be rephrased more specifically as “the side to which the operation member is moved from the OFF position toward the ON position in the moving direction” and “the side to which the operation member is moved from the ON position toward the OFF position in the moving direction”.

In one aspect of the present disclosure, the first interference part may include at least one projection protruding toward the lock member. Further, the second interference part may include at least one projection protruding toward the operation member.

In one aspect of the present disclosure, the lock member may be movable from the lock-release position in a first direction and a second direction which is different from the first direction. The lock member may be configured to serve as the first lock member to lock the operation member in the ON position when moved from the lock-release position to a specified position in the first direction, and to serve as the second lock member to lock the operation member in the OFF position when moved from the lock-release position to the lock position in the second direction.

In one aspect of the present disclosure, the lock member may be movable in a direction orthogonal to the drive axis. Further, the first direction and the second direction may be opposite to each other.

In one aspect of the present disclosure, the holding mechanism may be configured to hold the lock member in the specified position, the lock position and the lock-release position.

In one aspect of the present disclosure, the operation member may include a first interference part. The lock member may include a second interference part. The second interference part may include an ON-lock part and an OFF-lock part. The ON-lock part may be configured to lock the operation member in the ON position by abutting on the first interference part on the OFF position side of the first interference part when the lock member is in the specified position. The OFF-lock part may be configured to lock the operation member in the OFF position by abutting on the first interference part on the ON position side of the first interference part when the lock member is in the lock position.

In one aspect of the present disclosure, the first interference part may include at least one projection protruding toward the lock member. Further, the second interference part may include at least one projection protruding toward the operation member.

In one aspect of the present disclosure, the operation member may be configured to restrict a movement of the lock member from the lock-release position in the first direction when the operation member is in the OFF position. The operation member may be further configured to restrict a movement of the lock member from the lock-release position in the second direction when the operation member is in the ON position.

In one aspect of the present disclosure, the operation member may be provided in a front portion of the grip part so as to be movable in the front-rear direction. The lock member may be movable in a direction crossing the front-rear direction. The lock member may include a first abutment part and a second abutment part. The first and second abutment parts may be arranged at different positions in the front-rear direction and spaced apart from each other in a moving direction of the lock member. The first abutment part may be arranged forward of the second abutment part. Further, the operation member may be configured to abut on the first abutment part when the operation member is in the OFF position, thereby restricting the movement of the lock member in the first direction, and to abut on the second abutment part when the operation member is in the ON position, thereby restricting the movement of the lock member in the second direction.

In one aspect of the present disclosure, each of the first and second abutment parts may be a projection protruding toward the operation member.

In one aspect of the present disclosure, the operation member may include a receiving part configured to abut on the first abutment part and on the second abutment part. The first abutment part my be configured to lock the operation member in the ON position by abutting on a front surface of the receiving part when the lock member is in the specified position. Further, the second abutment part may be configured to lock the operation member in the OFF position by abutting on a rear surface of the receiving part when the lock member is in the lock position.

In one aspect of the present disclosure, the receiving part may include at least one projection protruding toward the lock member.

In one aspect of the present disclosure, the impact tool may further include a battery-mounting part which is configured to removably receive a rechargeable battery.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An embodiment is now described with reference to the drawings. In the present embodiment, an electric hammer (also called as a scraper)1is described as an example. The electric hammer1is an example of an impact tool which is configured to only linearly drive a tool accessory91along a specified drive axis A1. The electric hammer1may be used for a chipping operation or a scraping operation (surface preparation).

First, the general structure of the electric hammer1is described. As shown inFIGS. 1 and 2, an outer shell of the electric hammer1is mainly formed by a body housing10and a handle15.

The body housing10is generally L-shaped and includes a driving-mechanism-housing part11and a motor-housing part13. The driving-mechanism-housing part11extends along the drive axis A1. A tool holder39to which the tool accessory91may be removably coupled is provided in one axial end portion of the driving-mechanism-housing part11in a direction of the drive axis A1. The motor-housing part13is connected to the other axial end portion of the driving-mechanism-housing part11on the side opposite to the tool holder39. The motor-housing part13extends in a direction crossing (more specifically, generally orthogonal to) the drive axis A1. The driving-mechanism-housing part11houses a motion-converting mechanism3and a striking mechanism4, which will be described later. The motor-housing part13houses a motor2.

In the following description, for convenience sake, the extending direction of the drive axis A1of the electric hammer1(hereinafter also referred to as a drive-axis-A1direction) is defined as a front-rear direction of the electric hammer1. In the front-rear direction, the side of the one axial end portion of the electric hammer1in which the tool holder39is disposed is defined as a front side (or a front end region side) of the electric hammer1and the opposite side is defined as a rear side. Further, a direction orthogonal to the drive axis A1and corresponding to the extending direction of the motor-housing part13is defined as an up-down direction of the electric hammer1. In the up-down direction, a direction toward which the motor-housing part13protrudes from the driving-mechanism-housing part11is defined as a downward direction and the opposite direction is defined as an upward direction. A direction orthogonal to the front-rear direction and the up-down direction is defined as a left-right direction.

The handle15is generally C-shaped and includes a grip part151and connection parts153,156. The grip part151is an elongate portion to be held by a user and extends in the up-down direction behind the body housing10. A trigger16which can be depressed by the user is provided on a front portion of the grip part151. The connection parts153,156protrude forward from upper and lower end portions of the grip part151, respectively, and are connected to a rear end portion of the body housing10. A battery-mounting part159, which is configured to removably receive a rechargeable battery93, is provided on a lower end portion of the lower connection part156. The structure of the battery-mounting part159is well known and therefore not described in detail here.

The structure of the electric hammer1is now described in detail.

First, the internal structure of the body housing10is described. As shown inFIG. 2, the motor2is housed in a central portion of the motor-housing part12of the body housing10. In the present embodiment, a direct current (DC) brushless motor is employed as the motor2. The motor2is arranged such that a motor shaft23which rotates together with a rotor21extends in the up-down direction, orthogonal to the drive axis A1. A controller27which is configured to control driving of the motor2is housed in a lower end portion of the motor-housing part13.

Further, the motion-converting mechanism3is housed in a rear portion of the driving-mechanism-housing part11, and the striking mechanism4is housed in a front portion of the driving-mechanism-housing part11. The motion-converting mechanism3is configured to convert rotation of the motor shaft23into linear motion and transmit it to the striking mechanism4. In the present embodiment, the motion-converting mechanism3is configured as a crank mechanism including a crank shaft31, a connecting rod33, a piston35and a cylinder37. The striking mechanism4is configured to apply striking force to the tool accessory91in the drive-axis-A1direction. In the present embodiment, the striking mechanism4includes a striker41and an impact bolt43. The structures of the motion-converting mechanism (crank mechanism)3and the striking mechanism4are well known and therefore not described in detail here.

When the motor2is driven and the piston35is moved forward within the cylinder37, air in an air chamber formed between the piston35and the striker41is compressed so that the internal pressure increases. Therefore, the striker41is pushed forward at high speed by the action of an air spring and collides with the impact bolt43, thereby transmitting its kinetic energy to the tool accessory91. As a result, the tool accessory91is linearly driven along the drive axis A1and strikes a workpiece. On the other hand, when the piston35is moved rearward, the air in the air chamber expands so that the internal pressure decreases and the striker41is retracted rearward. The chipping or scraping operation (surface preparation) may be performed while such operations of the motion-converting mechanism30and the striking mechanism are repeated.

The internal structure of the handle15is now described. As shown inFIG. 2, the trigger16is provided on the front portion of the grip part151of the handle15. In the present embodiment, the trigger16is configured as an elongate lever extending in the up-down direction. The trigger16is supported by the grip part151so as to be pivotable generally in the front-rear direction. More specifically, the trigger16is pivotable between a frontmost position shown inFIG. 3and a rearmost position shown inFIG. 4, around a lower end portion of the trigger16. The trigger16has a projection161protruding upward from its upper end portion. In the present embodiment, two such projections161are provided apart from each other in the left-right direction (seeFIG. 5). Each of the projections161has a rectangular block-like shape having a front surface162and a rear surface163. The front surface162and the rear surface163are surfaces which are generally orthogonal to the moving direction of the trigger16, and are opposed to each other in the moving direction. The projection161is configured to be engageable with a lock member18(specifically, with a projection184), which will be described in detail later.

As shown inFIG. 2, a switch17for energizing the motor2(in other words, for driving the tool accessory91) is housed within the grip part151. The trigger16is normally (in a non-depressed state) biased forward by a plunger171which protrudes from a body170of the switch17, and held in the frontmost position (shown inFIG. 3) within a pivot range of the trigger16. In the frontmost position, the front surface162of the projection161is in abutment with a rear end of a lower wall of the connection part153, and the switch17is in an OFF state. When the trigger16is depressed and turned rearward to a specific position (also referred to as a switching position) within the pivot range, the plunger171is pushed into the body170and the switch17is placed in an ON state. When the switch17is in the ON state, the motor2is energized and the tool accessory91is driven.

In the present embodiment, the rearmost position (shown inFIG. 4) of the trigger16in the pivot range is set slightly rearward of the switching position. Therefore, the switch17is held in the OFF state when the trigger16is located within a range (excluding the switching position) between the frontmost position and the switching position, and the switch17is held in the ON state when the trigger16is located within a range (including the switching position) between the switching position and the rearmost position. In the following description, the position of the trigger16(between the frontmost position and the switching position) to place the switch17in the OFF state is referred to as an OFF position, and the position of the trigger16(between the switching position and the rearmost position) to place the switch17in the ON state is referred to as an ON position.

As shown inFIG. 2, a lock member18is provided in the upper connection part153of the handle15. The lock member18of the present embodiment has a function of locking the trigger16in the OFF position (also referred to as a trigger-lock function) and a function of locking the trigger16in the ON position (also referred to as an on-lock function). The function of locking the trigger16in the OFF position can also be rephrased as a function of restricting the trigger16from moving to the ON position. The manner of restricting the trigger16from moving to the ON position includes not only the manner of completely preventing the movement from the OFF position, but the manner of preventing the movement up to the ON position while allowing a slight movement from the OFF position. Similarly, the function of locking the trigger16in the ON position can also be rephrased as a function of restricting the trigger16from moving to the OFF position. The manner of restricting the trigger16from moving to the OFF position includes not only the manner of completely preventing the movement from the ON position, but the manner of preventing the movement up to the OFF position while allowing a slight movement from the ON position.

The structure of the lock member18is now described in detail. In the present embodiment, as shown inFIG. 2, the lock member18is a rod-like member having a generally elliptical section. The lock member18is supported above the trigger16by the connection part153so as to be movable in the left-right direction. More specifically, as shown inFIGS. 5 and 6, through holes154and155are formed in left and right walls of the connection part153, respectively. Left and right end parts181,182of the lock member18are respectively inserted through the through holes154,155so that the lock member18is supported to be slidable in the left-right direction. The right end part182of the lock member18has a different structure from the left end part181. Specifically, the right end part182is configured as a large-diameter part having a slightly larger diameter than the left end part181. Correspondingly, the through hole155is formed slightly larger than the through hole154. The left and right end parts181,182are at least partially exposed to the outside from the connection part153through the through holes154,155, respectively, and serve as operation parts to be pushed rightward or leftward by the user.

A projection184is provided to protrude downward from a lower end of the lock member18. In the present embodiment, there are two such projections184which are respectively engageable with the two projections161of the trigger16. The two projections184are arranged apart from each other in the left-right direction, with a spacing which is larger than the width of the projection161of the trigger16in the left-right direction. The spacing between the projections161of the trigger16in the left-right direction is also larger than the width of the projection184of the lock member18in the left-right direction. The width of the projection184in the left-right direction is generally equal to the width of the projection161in the left-right direction. Further, the projection184has a rectangular block-like shape having a front surface185and a rear surface186, as shown inFIG. 3. The front surface185and the rear surface186are generally orthogonal to the moving direction of the trigger16and opposed to each other in the moving direction.

Further, as shown inFIGS. 5 and 6, a projection is provided to protrude upward on a central upper end portion of the lock member18. The projection has two recesses recessed downward and arranged side by side in the left-right direction. The left recess and the right recess are hereinafter referred to as a first recess188and a second recess189, respectively. Further, a flat spring157is disposed within the connection part153such that the flat spring157is opposed to the lock member18from above. A generally central portion of the flat spring157is formed as a protruding portion protruding downward. The flat spring157may be snap-engaged with the first recess188or the second recess189via this protruding portion, thereby holding the lock member18in a specified position (where the protruding portion is engaged with the first recess188or with the second recess189), thereby restricting the lock member18from sliding relative to the connection part153in the left-right direction. Thus, even if the lock member18is released after once pushed to move by the user, the lock member18does not automatically return to an initial position. The user can move the lock member18rightward or leftward from the specified position against the biasing force of the flat spring157by pushing the left end part181rightward, or by pushing the right end part182leftward.

The trigger-lock function and the on-lock function of the lock member18are now described.

As shown inFIG. 5, when the right end part (large-diameter part)182is pushed leftward and the lock member18is placed in a position in which the flat spring157is engaged with the second recess (right recess)189, the left end part181protrudes leftward from the connection part153. At this time, the two projections184of the lock member18are disposed in positions respectively deviated leftward from moving paths of the two projections161of the trigger16which is movable between the frontmost position (seeFIG. 3) and the rearmost position (seeFIG. 4). In other words, the lock member18is disposed in a position in which the projections161do not interfere with the projections184in the process of movement of the trigger16between the frontmost position and the rearmost position. Therefore, by depressing the trigger16placed in the frontmost position as shown inFIG. 7, the user can move the trigger16rearward up to the rearmost position as shown inFIG. 8. When the user releases the trigger16, the trigger16is biased forward by the plunger171and returned to the frontmost position shown inFIG. 7.

In this manner, when the lock member18is placed in a position in which the protruding portion of the flat spring157is engaged with the second recess189, the lock member18allows the trigger16to move between the frontmost position and the rearmost position and cannot lock the trigger16in the ON position or in the OFF position. Accordingly, the position of the lock member18in which the protruding portion of the flat spring157is engaged with the second recess189is also referred to as a lock-release position.

As shown inFIG. 6, when the left end part181is pushed rightward and the lock member18is disposed in a position in which the flat spring157is engaged with the first recess (left recess)188, the right end part182protrudes rightward from the connection part153. At this time, the two projections184of the lock member18are disposed on the moving paths of the two projections161of the trigger16. In other words, the lock member18is disposed in a position in which the projections161interfere with the projections184in the process of movement of the trigger16between the frontmost position and the rearmost position.

As shown inFIG. 3, when the lock member18is placed in this position while the trigger16is located in the frontmost position, the projections184are located slightly rearward of the projections161of the trigger16. In this state, when the user depresses the trigger16, as shown inFIG. 9, the rear surfaces163(seeFIG. 3) of the projections161of the trigger16abut on the front surfaces185(seeFIG. 3) of the respective projections184of the lock member18, so that the trigger16is prevented from further moving rearward. At this time, the trigger16is in the OFF position. In other words, the lock member18locks the trigger16in the OFF position (performs the trigger-lock function) through engagement (abutment) between the projections184and161. Therefore, unless moving the lock member18to the above-described lock-release position (seeFIG. 5), the user cannot depress the trigger16and thus cannot cause the tool accessory91to be driven.

When the lock member18is disposed in the lock-release position (seeFIG. 5) and thereafter, as shown inFIG. 4, moved to the position in which the flat spring157is engaged with the first recess188while the trigger16is depressed to be placed in the rearmost position, the projections184are located slightly forward of the projections161of the trigger16. In this state, when the user releases the trigger16, the trigger16is biased forward by the plunger171. As shown inFIG. 10, however, the front surfaces162(seeFIG. 3) of the projections161abut on the rear surfaces186(seeFIG. 3) of the respective projections184, so that the trigger16is prevented from further moving forward. At this time, the trigger16is in the ON position. In other words, the lock member18locks the trigger16in the ON position (performs the on-lock function) through engagement (abutment) between the projections184and161. Therefore, even if the user releases the trigger16, the switch17is kept in the ON state and the tool accessory91is kept driven. Unless moving the lock member18to the above-described lock-release position (seeFIG. 5), the user cannot return the trigger16to the OFF position and stop driving of the tool accessory91.

In this manner, when the lock member18is placed in a position in which the protruding portion of the flat spring157is engaged with the first recess188, the lock member18can lock the trigger16in the ON position or in the OFF position. Accordingly, the position of the lock member18in which the protruding portion of the flat spring157is engaged with the first recess188is also referred to as a lock position.

As described above, the electric hammer1of the present embodiment includes the lock member18having both the on-lock function and the trigger-lock function. Therefore, when the user wants to keep driving the tool accessory91for a while, the user can lock the trigger16in the ON position with the lock member18, thereby eliminating the need for troublesome operation of keeping depressing the trigger16. Further, for example, when the operation is suspended for a while, the user can lock the trigger16in the OFF position with the lock member18, thereby preventing the tool accessory91from being unintentionally driven. Particularly, the electric hammer1of the present embodiment may be carried or stored with the battery (power source)93left mounted thereto. Therefore, by locking the trigger16in the OFF position with the lock member18when carrying or storing the electric hammer1, the tool accessory91can be prevented from being unintentionally driven due to some cause.

Further, in the present embodiment, the flat spring157is provided which is configured to hold the lock member18in the lock position and also in the lock-release position. Therefore, even if the external operation of the lock member18is released by the user after the lock member18is placed in the lock-release position, the lock member18is held in the lock-release position by the flat spring157and does not automatically return to the lock position. Similarly, even if the external operation of the lock member18is released by the user after the lock member18is placed in the lock position, the lock member18does not automatically return to the lock-release position. The lock of the trigger16can be released only by moving the lock member18to the lock-release position, regardless of an operation of the trigger16.

Therefore, for example, when moving the trigger16locked in the OFF position to the ON position, the user need not perform a troublesome two-action operation of holding the lock member18in the lock-release position and moving the trigger16to the ON position at the same time. In other words, once moving the lock member18to the lock-release position, the user can cause the tool accessory91to be driven in one action (only by depressing the trigger16). In the chipping or scraping operation, the user may operate the trigger16to drive the tool accessory91while shifting the machining position little by little. In such a case, the user may need to repeat the operations of depressing and releasing the trigger16at short intervals. The lock member18of the present embodiment, however, does not require the two-action operation for each depressing operation of the trigger16, so that work efficiency and convenience can be improved.

Further, the user can easily switch the position of the lock member18simply by moving the lock member18against the biasing force of the flat spring157since the lock member18is held in the lock position or in the lock-release position only by the biasing force of the flat spring157.

Further, in the present embodiment, the trigger16is provided on the grip part151extending in the up-down direction orthogonal to the drive axis A1, and the lock member18is disposed on the upper side of the grip part151. In other words, the lock member18and the trigger16are provided in different portions, but relatively close to each other. Thus, the structure for locking the trigger16can be realized in a relatively compact structure, utilizing engagement between the projections161and184.

Further, in the present embodiment, the lock member18can be moved in a direction crossing the moving direction of the trigger16between the lock position, in which the lock member18is capable of locking the trigger16in the OFF position, and the lock-release position, in which the lock member18is incapable of locking the trigger16in the OFF position, in response to the external operation by the user. Specifically, the lock member18can be moved in the left-right direction between the lock position and the lock-release position, while the trigger16can be moved in the generally left-right direction. The moving directions of the trigger16and the lock member18correspond to the respective operating directions. Therefore, the user can easily lock the trigger16in the OFF position and release the lock by moving the lock member18. Further, when operating one of the trigger16and the lock member18, the user can be prevented from mistakenly operating the other since the operating directions of the trigger16and the lock member18are different from each other.

In the present embodiment, the both end portions of the lock member18in the moving direction (i.e. the left-right direction) are disposed to be externally operated by the user and have different structures. Specifically, the right end part182which is pushed to release the lock of the trigger16has a larger diameter than the left end part181which is pushed to lock the trigger16in the ON position or in the OFF position. Therefore, the user can easily recognize which one of the left and right end parts181,182should be operated when moving the lock member18to the lock position or to the lock-release position.

In the present embodiment, the single lock member18has both the on-lock function of locking the trigger16in the ON position and the trigger-lock function of locking the trigger16in the OFF position. Therefore, both of the functions are realized in a more compact and simpler structure than in a structure using two separate lock members. Further, in the present embodiment, the lock member18performs the on-lock function and the trigger-lock function by interference of the projections184with the projections161of the trigger16on the moving paths of the projections161when the lock member18is in the lock position. Specifically, the rear surface186(on the ON position side (rear side)) and the front surface185(on the OFF position side (front side)) of the projection184, which are opposed to each other and arranged to cross the moving direction of the trigger16, lock the trigger16respectively in the ON position and in the OFF position by abutting on the projection161. Thus, the lock member18is capable of performing the on-lock function or the trigger-lock function in the same position (in the lock position), depending on which one of the rear surface186and the front surface185of the projection184abuts on the projection161. In this manner, the lock member18which is capable of performing the both functions is realized in a compact, simple and easy-to-operate structure.

Correspondences between the features of the embodiment and the features of the disclosure are as follows. The electric hammer1is an example that corresponds to the “impact tool”. The drive axis A1is an example that corresponds to the “drive axis”. The switch17is an example that corresponds to the “switch”. The trigger16is an example that corresponds to the “operation member”. The lock member18is an example that corresponds to each of the “first lock member”, the “second lock member” and the “single lock member”. The grip part151is an example that corresponds to the “grip part”. The flat spring157and the first and second recesses188,189as a whole is an example that corresponds to the “holding mechanism”. Each of the projections161of the trigger16is an example that corresponds to the “first interference part”. Each of the projections184of the lock member18is an example that corresponds to the “second interference part”. The rear surface186and the front surface185of the projection184are examples that correspond to the “first surface” and the “second surface”, respectively. The battery-mounting part159is an example that corresponds to the “battery-mounting part”.

The above-described embodiment is a mere example and an impact tool according to the present disclosure is not limited to the structure of the electric hammer1of the above-described embodiment. For example, the following modifications may be made. Further, one or more of these modifications may be employed in combination with the electric hammer1of the above-described embodiment or the claimed invention.

For example, the on-lock function of locking the trigger16in the ON position and the trigger-lock function of locking the trigger16in the OFF position may be realized by a plurality of separate lock members in place of the single lock member18. In this case, for example, two lock members, each of which, like the lock member18, can be moved in the left-right direction between the lock position and the lock-release position, may be provided respectively corresponding to the ON position and the OFF position of the trigger16. Alternatively, two lock members may be provided to be movable in different directions from each other between the lock position and the lock-release position.

In the above-described embodiment, the lock member18can lock the trigger16in the ON position and in the OFF position when placed in the same lock position, while allowing the trigger16to move from the ON position to the OFF position as well as from the OFF position to the ON position when placed in the same lock-release position. Even when using the single lock member18to realize the on-lock function and the trigger-lock function, however, a lock position for locking the trigger16in the ON position and a lock position for locking the trigger16in the OFF position may be different from each other. Similarly, a lock-release position for allowing the trigger16to move from the ON position to the OFF position and a lock-release position for allowing the trigger16to move from the OFF position to the ON position may be different from each other.

As an example of such a modification, with reference toFIGS. 11 to 15, a lock member19is now described. The lock member19has different lock positions for locking the trigger16in the ON position and for locking the trigger16in the OFF position, and has a common lock-release position. In the present modification, the body housing10, the handle15and the trigger16are slightly different in shape from those of the above-described embodiment, but substantially have the same structures. Accordingly, in the following description and the drawings to be referred, components having substantially the same structures are given the same numerals, and are not described or only briefly described.

As shown inFIG. 11, like the lock member18of the above-described embodiment, the lock member19of the present modification is a rod-like member. The lock member19is supported above the trigger16by the connection part153so as to be movable in the left-right direction, while left and right end portions of the lock member19are respectively inserted through the through holes154,155. Further, unlike the lock member18, the left and right end portions of the lock member19have the same shape.

Further, in the present modification, three projections are provided to protrude downward from the lower end portion of the lock member19. The three projections have generally the same protruding length. The three projections are spaced apart from each other in the left-right direction, and each of the distances between adjacent two projections is larger than the width of the projection161of the trigger16in the left-right direction. The central, left and right projections are hereinafter referred to as a first projection193, a second projection194and a third projection195, respectively.

As shown inFIG. 12, the first to third projections193to195each have a rectangular block-like shape. The first to third projections193to195have different sizes in the front-rear direction and are arranged at different positions in the front-rear direction. More specifically, the first projection193has the shortest length in the front-rear direction. The second projection194on the left of the first projection193is arranged such that the front end of the second projection194is at the same position as the front end of the first projection193in the front-rear direction and extends further rearward than the rear end of the first projection193. The third projection195on the right of the first projection193is arranged such that the rear end of the third projection195is at the same position as the rear end of the first projection193in the front-rear direction and extends further forward than the front end of the first projection193.

Further, as shown inFIG. 11, a projection is provided to protrude upward on a central upper end portion of the lock member19. In the present modification, the projection has three recesses recessed downward. The central, left and right recesses are hereinafter referred to as a first recess197, a second recess198and a third recess199, respectively. The first recess197is provided in the center of the lock member19in the left-right direction. Like in the above-described embodiment, the flat spring157is disposed within the connection part153. The flat spring157may be snap-engaged with one of the first to third recesses197to199via the protruding portion of the flat spring157, thereby holding the lock member19in a specified position (where the protruding portion is engaged with the one of the first to third recesses197to199).

The trigger-lock function and the locking function of the lock member19are now described.

In the present modification, as shown inFIG. 11, the position of the lock member19in which the protruding portion of the flat spring157is engaged with the first recess197(i.e. in which the centers of the lock member19and the handle15in the left-right direction coincide with each other) is set as a lock-release position. When the lock member19is placed in the lock-release position, the two projections161of the trigger16are respectively located between the first projection193and the second projection194and between the first projection193and the third projection195in the left-right direction. Thus, the trigger16is allowed to move between the frontmost position (seeFIGS. 3 and 12) and the rearmost position (seeFIGS. 4 and 14). Unless depressed, the trigger16is biased by the plunger171(seeFIG. 2) and held in the frontmost position (i.e. the OFF position). Further, as shown inFIG. 12, when the trigger16is in the frontmost position, the front ends of the first and second projections193,194are located at generally the same position as the rear ends of the projections161in the front-rear direction. Further, the front end of the third projection195is located forward of the rear ends of the projections161(more specifically, at generally the same position as the front ends of the projections161) in the front-rear direction.

In this state, when a user pushes the left end portion of the lock member19to move the lock member19rightward from the lock-release position, the protruding part of the flat spring157is snap-engaged with the second recess198(seeFIG. 11), and the lock member19is held in this position by the biasing force of the flat spring157.

In this position, as shown inFIG. 13, the first projection (central projection)193and the second projection (left projection)194of the lock member19are disposed behind the two projections161of the trigger16(on the moving paths of the first and second projections193,194when the trigger16moves from the frontmost position toward the rearmost position). When the user depresses the trigger16, the rear surfaces of the projections161of the trigger16abut on the front surfaces of the first and second projections193,194, so that the trigger16is prevented from further moving rearward and cannot reach the ON position. In other words, the lock member19locks the trigger16in the OFF position (performs the trigger-lock function) through engagement (abutment) between the first and second projections193,194and the two projections161. Accordingly, the position of the lock member19in which the protruding portion of the flat spring157is engaged with the second recess198is hereinafter also referred to as an OFF-lock position.

As shown inFIG. 12, when the user pushes the right end portion of the lock member19in a state in which the lock member18is in the lock-release position and the trigger16is held in the frontmost position (OFF position), the right projection161of the trigger16abuts on a left surface of the third projection195and thereby prevents the lock member19from further moving leftward. Thus, when the trigger16is disposed in the frontmost position, the user cannot move the lock member19leftward (toward an ON-lock position shown inFIG. 15) from the lock-release position.

When a user depresses the trigger16in a state in which the lock member19is in the lock-release position, as shown inFIG. 14, the trigger16can be moved up to the rearmost position. When the trigger16is placed in the rearmost position, the rear ends of the first and third projections193,195are located at generally the same position as the front ends of the projections161in the front-rear direction, and the rear end of the second projection194is located rearward of the front ends of the projections161(specifically, at generally the same position as the rear ends of the projections161) in the front-rear direction.

In this state, when the user pushes the right end portion of the lock member19to move the lock member19leftward from the lock-release position, the protruding portion of the flat spring157is snap-engaged with the third recess199(seeFIG. 11) and the lock member19is held in this position by the biasing force of the flat spring157.

In this position, as shown inFIG. 15, the first projection (central projection)193and the third projection (right projection)195of the lock member19are located in front of the two projections161of the trigger16(on the moving paths of the first and third projections193,195when the trigger16moves from the rearmost position to the frontmost position). When the user releases the trigger16, the front surfaces of the projections161of the trigger16abut on the rear surfaces of the first and third projections193,195, so that, although being biased forward by the plunger171, the trigger16is prevented from further moving forward and cannot reach the OFF position. In other words, the lock member19locks the trigger16in the ON position (performs the on-lock function) through engagement (abutment) between the first and third projections193,195and the two projections161. Accordingly, the position of the lock member19in which the protruding portion of the flat spring157is engaged with the third recess199is hereinafter also referred to as an ON-lock position.

As shown inFIG. 14, when the user pushes the left end portion of the lock member19in a state in which the lock member19is in the lock-release position and the trigger16is held in the rearmost position (ON position), the left projection161of the trigger16abuts on a right surface of the second projection194and thereby prevents the lock member19from further moving rightward. Thus, when the trigger16is disposed in the rearmost position, the user cannot move the lock member19rightward (toward the OFF-lock position shown inFIG. 13) from the lock-release position.

As described above, in the present modification, the user can lock the trigger16in the ON position by moving the single lock member19leftward from the lock-release position, and can lock the trigger16in the OFF position by moving the lock member19rightward from the lock-release position. In other words, two different operating (moving) directions (leftward and rightward) are set, using the lock-release position as a reference position, for the two different functions of the lock member19(i.e. the function of locking the trigger16in the ON position and the function of locking the trigger16in the OFF position). Thus, the user can easily understand how to operate the lock member19. Further, for example, a mark or other similar indicator indicating an operating direction and a corresponding function may be provided on an upper surface of the lock member19or the connection part153, in order to make it easier for the user to understand an appropriate operating direction.

Further, in the present modification, the trigger16(specifically, the projections161) is configured to restrict a leftward movement of the lock member19from the lock-release position when the trigger16is in the OFF position, and to restrict a rightward movement of the lock member19from the lock-release position when the trigger16is in the ON position. More specifically, the lock member19has the second projection194and the third projection195which are arranged at different positions in the front-rear direction and spaced apart from each other in the left-right direction (i.e. the moving direction of the lock member19). In the frontmost position (i.e. OFF position), the trigger16(the projections161) abuts on the third projection195, which is arranged forward of the second projection194, thereby preventing the further leftward movement of the lock member19. In the rearmost position (i.e. ON position), the trigger16abuts on the second projection194, which is arranged rearward of the third projection195, thereby preventing a further rightward movement of the lock member19. Therefore, when the trigger16is located in the frontmost position, the lock member18can be moved to the OFF-lock position, but not to the ON-lock position. Further, when the trigger16is located in the rearmost position, the lock member18can be moved to the ON-lock position, but not to the OFF-lock position. Therefore, the user can easily recognize a direction to move the lock member19, depending on the position of the trigger16, and the lock member19can perform an appropriate function depending on the position of the trigger16.

In the present modification, the first and third projections193,195of the lock member19are configured to lock the trigger16in the ON position by abutting on the projections161on the front of the projections161of the trigger16when the lock member19is disposed in the ON-lock position. Further, the first and second projections193,194are configured to lock the trigger16in the OFF position by abutting on the projections161on the rear of the projections161of the trigger16when the lock member19is disposed in the OFF-lock position. In this manner, also in the present modification, the lock member19which is capable of locking the trigger16in the OFF position and also in the ON position is realized in a compact, simple and easy-to-operate structure.

In the present modification, the lock member19is an example that corresponds to each of the “first lock member”, the “second lock member” and the “single lock member”. The ON-lock position, the OFF-lock position and the lock-release position of the lock member19are examples that correspond to the “specified position”, the “lock position” and the “lock-release position”, respectively. Each of the projections161of the trigger16is an example that corresponds to the “first interference part”. Each of the first to third projections193to195is an example that corresponds to the “second interference part”. Each of the first and third projections193,195is an example that corresponds to the “ON-lock part”. Each of the first and second projections193,194is an example that corresponds to the “OFF-lock part”.

Further, in a structure in which the switch17is held in the ON state when the trigger16is located within a certain range, like the range (including the switching position) between the switching position and the rearmost position in the above-described embodiment and modification, the controller27may control a rotation speed of the motor2such that the rotation speed increases as a depressed amount of the trigger16increases. In this case, it may be preferred that the lock member18,19is capable of locking the trigger16in the ON position which corresponds to the maximum rotation speed of the motor2. Alternatively, the lock member18,19may be capable of locking the trigger16in a plurality of ON positions (different ON positions in the front-rear direction) which respectively correspond to different rotation speeds of the motor2. For example, a plurality of projections each having a rear surface arranged in a different position in the front-rear direction from the other may be provided on the trigger16and the lock member18,19.

In the above-described embodiment, the on-lock function and the trigger-lock function are realized by engagement (abutment) between the two projections184of the lock member18and the two projections161of the trigger16. The numbers of the projections184and161may, however, be one, three or more. Further, the engagement (abutment) between the lock member18and the trigger16when the lock member18is in the lock position may be realized by structures other than the projections184and161. For example, a rod-like lock member may be arranged to be movable in the left-right direction or in the up-down direction between a lock position, in which the lock member is partially located on the moving path of the upper end of the trigger16, and a lock-release position, in which the lock member is entirely located out of the moving path. In this case, like the above-described embodiment, the on-lock function and the trigger-lock function can be realized with the single lock member by arranging the lock member in a position corresponding to the projections184of the above-described embodiment in the front-rear direction. Further, the lock member may be of a rotary type, instead of the linearly sliding type. The lock member need not be disposed on an upper side of the grip part151(within the connection part153), but may be disposed, for example, within the grip part151.

Similar changes may also be made to the lock member19. For example, the lock member19may have only the first projection193. In this case, when the lock member19is in the ON-lock position, the first projection193can lock the trigger16in the ON position by abutting on the left projection161on the front of the left projection161of the trigger16. Further, when the lock member19is in the OFF-lock position, the first projection193can lock the trigger16in the OFF position by abutting on the right projection161on the rear of the right projection161.

Alternatively, for example, the lock member19may have only the first and second projections193,194, and the trigger16has only the left projection161. In this case, when the lock member19is in the ON-lock position, the first projection193can lock the trigger16in the ON position by abutting on the projection161on the front of the projection161. Further, when the lock member19is in the OFF-lock position, the second projection194can lock the trigger16in the OFF position by abutting on the projection161on the rear of the projection161. In this case, the rear end of the second projection194may be arranged at the same position as the rear end of the first projection193in the front-rear direction. Further, the front end of the first projection193may be arranged forward of the front end of the second projection194, that is, forward of the rear end of the projection161of the trigger16when the trigger16is in the OFF position.

Further, the lock member19may have two projections having the same shape and arranged at the same position in the front-rear direction, and the trigger16may have three projections arranged at different positions in the front-rear direction. In other words, the projections of the lock member19and the trigger16may be replaced with each other. In this case, as described above, the number, arrangement and size of the projections may also be appropriately changed.

The structure for holding the lock member18in the lock position and in the lock-release position is not limited to the flat spring157and the first and second recesses188,189, but may be appropriately changed. For example, the flat spring157may be provided on the lock member18, and the first and second recesses188,189may be provided in the connection part153. Alternatively, for example, a flexible locking piece may be provided on one of the lock member18and the connection part153, and a groove which can be engaged with the locking piece may be provided on the other. Similar changes may also be made to the structure for holding the lock member19in the ON-lock position, the OFF-lock position and the lock-release position.

Further, for example, the power source of the electric hammer1may be an external alternate current (AC) source, instead of the removably mounted battery93. The structures of the motor2, the motion-converting mechanism3and the striking mechanism4may also be appropriately changed. For example, an AC motor having a brush may be employed as the motor2. A well-known motion-converting mechanism having a swinging member may be employed as the motion-converting mechanism3, in place of the crank mechanism.

In view of the nature of the present invention and the above-described embodiment, the following aspects are provided. The following aspects can be employed in combination with any of the electric hammer1of the embodiment and the above-described modifications, or in combination with the claimed invention.

The second lock member may be movable between a lock position and a lock-release position in response to an external operation by a user, the second lock member in the lock position being capable of locking the operation member in the OFF position by partially interfering with the operation member on a moving path of the operation member, the second lock member in the lock-release position being entirely out of the moving path.

The lock member may be movable between a lock position and a lock-release position in response to an external operation by a user, the lock member in the lock position being capable of locking the operation member both in the ON position and in the OFF position, the lock member in the lock-release position allowing the operation member to move between the OFF position and the ON position.

In Aspect 2, the lock member may be configured to partially interfere with the operation member on a moving path of the operation member when the lock member is in the lock position, and to be entirely out of the moving path of the operation member when the lock member is in the lock-release position.

The operation member may be provided on a front portion of the grip part so as to be movable in the front-rear direction, and

the second lock member or the lock member may be disposed to be movable in a left-right direction, which is orthogonal to the front-rear direction and to the up-down direction.

The first interference part may comprise a projection protruding toward the lock member, and

the second interference part may comprise a projection protruding toward the operation member.

The holding mechanism may be configured to hold the second lock member in the lock position and in the lock-release position by snap-engagement.

The holding mechanism may be configured to release the second lock member in response to an external operation of the second lock member, regardless of an external operation of the operation member.

The lock member may be movable in a direction orthogonal to the drive axis, and

the first direction and the second direction may be opposite to each other.

The holding mechanism may be configured to hold the lock member in the specified position, the lock position and the lock-release position.

The operation member may be configured to:allow the lock member to move from the lock-release position only in the second direction when the operation member is in the OFF position, andallow the lock member to move from the lock-release position only in the first direction when the operation member is in the ON position.
(Aspect 11)

The operation member may be provided in a front portion of the grip part so as to be movable in the front-rear direction,

the lock member may be movable in a direction crossing the front-rear direction,

the lock member may have a first abutment part and a second abutment part, the first and second abutment parts being arranged at different positions in the front-rear direction and spaced apart from each other in a moving direction of the lock member, the first abutment part being arranged forward of the second abutment part, and

the operation member may be configured to:abut on the first abutment part when the operation member is in the OFF position, thereby restricting the lock member from moving in the first direction, andabut on the second abutment part when the operation member is in the ON position, thereby restricting the lock member from moving in the second direction.

The third projection195and the second projection194of the above-described modification are examples that correspond to the “first abutment part” and the “second abutment part”, respectively, according to the present aspect.

In Aspect 11, the operation member may have a receiving part configured to abut on the first and second abutment parts.

In Aspect 12, the receiving part may comprise at least one projection protruding toward the lock member.

The projection161of the above-described modification is an example that corresponds to each of the “receiving part” and the “projection” according to aspects 12 and 13, respectively.

In Aspect 12 or 13,

the first abutment part may be configured to lock the operation member in the ON position by abutting on a front surface of the receiving part when the lock member is in the specified position, and

the second abutment part may be configured to lock the operation member in the OFF position by abutting on a rear surface of the receiving part when the lock member is in the lock position.

In any one of aspects 11 to 14, each of the first and second abutment parts may comprise a projection protruding toward the operation member.

The first interference part may comprise at least one projection protruding toward the operation member.

The second interference part may comprise at least one projection protruding toward the lock member.

DESCRIPTION OF NUMERALS