US20150328764A1

US20150328764A1 - Power tool

Info

Publication number: US20150328764A1
Application number: US14/810,298
Authority: US
Inventors: Kiyonobu Yoshikane; Hajime Takeuchi; Yoshiro Tada; Masanori Furusawa; Masao Miwa; Shinji Onoda; Yoshitaka Machida
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2013-02-01
Filing date: 2015-07-27
Publication date: 2015-11-19
Also published as: US20210402584A1; US20190381646A1; US20230173652A1; US11148272B2; US11597068B2

Abstract

A power tool includes a motor which drives a tool bit, a tool body, a handle, and battery mount part, to which battery is detachably mounted. The power tool includes a plurality of battery mount parts, and the battery mount part, includes a battery engaging part with which the battery, can engage. The battery is mounted to the battery mount part by sliding against the battery engaging part in a crossing direction which crosses the longitudinal direction of the tool bit.

Description

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of International. Applications (1) No. PCT/JP2014/052349, filed on Jan. 31, 2014, which claims priority to Japanese Patent Application No. 2013-018845 filed on Feb. 1, 2013, (2) No. PCT/JP2014/052350 filed on Jan. 31, 2014, which claims priority to Japanese Patent Application No. 2013-018846 filed on Feb. 1, 2013, (3) No. PCT/JP2014/052351, filed on Jan. 31, 2014, which claims priority to Japanese Patent Application No. 2013-018848 filed on Feb. 1, 2013, (4) No. PCT/JP2014/052352 filed on Jan. 31, 2014, which claims priority to Japanese Patent Application No. 2013-018849 filed on Feb. 1, 2013, and (5) No. PCT/JP2014/060835 filed on Apr. 16, 2014, which claims priority to Japanese Patent Application No. 2013-086952 filed on Apr. 17, 2013.
The contents of these applications are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a power tool which performs a predetermined operation.

BACKGROUND OF THE INVENTION

Japanese non-examined laid-open Patent Publication No. 2010-5751 discloses a battery type hammer drill in which the battery is provided as a power source. In this hammer drill, one battery is mounted on a lower surface of a downward extending part which connects a tool body and a handle.

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

The battery utilized to the battery type hammer drill is rechargeable, and when a battery remaining amount is reduced, operations to detach the battery from the hammer drill and to charge the battery and then to mount the battery again are necessary.
However, the battery has heavy weight and therefore there is room for improvement regarding an attaching/detaching operation of the battery.
Accordingly, an object of the present invention is, in consideration of the above described problem, to provide an improved power tool with respect to an attaching and detaching technique of a battery.

Means for Solving the Problem

The above-mentioned problem is solved by the present invention. According to a preferable aspect of a power tool of the present invention, a power tool which drives a detachably attached tool bit in a driving axis of the tool bit is provided. The power tool comprises a motor which drives the tool bit, a tool body which houses the motor, a handle which is connected to the tool body, and a battery mount part to which a battery for providing electric current is detachably mounted. The power tool comprises a plurality of the battery mount parts and can provide electric current from the battery mounted to the battery mount part to the motor. The handle is provided such that it extends in a handle extending direction crossing a driving axis extending direction in which the driving axis extends. The battery mount part comprises a battery engaging part with which the battery is engageable and the battery mount part holds the battery by engaging the battery with the battery engaging part. The battery is slid in a cross direction crossing both of the driving axis extending direction and the handle extending direction with respect to the battery engaging part and the battery is mounted to the battery mount part. Further, the handle is typically and preferably provided on a predetermined plane which includes the driving axis such that the handle extends in the handle extending direction crossing the driving axis extending direction.
According to the present invention, the power tool comprises a plurality of the battery mount parts and each battery is detachably mounted to each battery mount part.
Therefore, degree of freedom regarding an attaching of each battery is enhanced. Further, according to the present invention, the battery is moved in the cross direction crossing both of the driving axis extending direction and the handle extending direction against the battery engaging part and is mounted to the battery mount part. Therefore, in the power tool in which vibration in the driving axis extending direction is generated, a demounting direction (detaching direction) of the battery is perpendicular to a vibration direction. As a result, a possibility of dropping down of the battery from the battery mount part due to the vibration is reduced.
According to a further aspect of the power tool of the present invention, a plurality of the battery mount parts are aligned in the driving axis extending direction.
According to this aspect, a compact arrangement of a plurality of the batteries is possible. Accordingly, an arrangement of electric wiring which is connected to the battery mount part is simplified.
According to a further aspect of the power tool of the present invention, the battery engaging parts are provided such that the batteries are slid from the same side of the tool body with respect to the cross direction and engaged with the battery engaging parts. In other words, the battery is slid in the cross direction crossing both of the driving axis extending direction and the handle extending direction against the tool body (battery mount part) and mounted to the battery mount part. For example, in a case that the handle extending direction is defined as a vertical direction, the batteries which is mounted to the respective battery mount parts are moved from one side among the right side and the left side of the tool body.
According to this aspect, an attaching/detaching operation of the batteries is performed at one side of the tool bit. Accordingly, usability of the attaching/detaching operation of the battery by a user is improved. That is, the attaching/detaching operation is easily performed.
According to a further aspect of the power tool of the present invention, a plurality of the battery mount parts is arranged at a side opposite to the tool bit with respect to the motor in the driving axis extending direction. In other words, the motor is arranged between a plurality of the battery mount parts and the tool bit.
According to this aspect, the battery mounted to the battery mount part is arranged distantly form the tool bit. Accordingly, when the operation is performed by contacting the tool bit with a workpiece, since the battery is arranged distantly from the workpiece, interference by the battery with the operation by the tool bit is prevented.
According to a further aspect of the power tool of the present invention, when the battery is mounted to the battery mount part, a lower surface of the battery is formed flush with a lower surface of the tool body.
According to this aspect, in addition to the lower surface of the tool body, the lower surface of the battery is set as a contact surface when the power tool is placed on the ground or a floor. Accordingly, the power tool is stably placed.
According to a further aspect of the power tool of the present invention, the battery mount part is formed such that a length of the battery mounted to the battery mount part in the driving axis extending direction is shorter than a length in the cross direction.
According to this aspect, the battery mounted to the battery mount part such that the length of the battery in the driving axis extending direction is shorter that the length of the battery in the cross direction. Accordingly, with respect to the driving axis extending direction, whole length of the power tool to which the battery is mounted is shortened.
According to a further aspect of the power tool of the present invention, the batter mount part comprises an elastic member which protrudes toward the battery and contacts with the battery when the battery mounted to the battery mount part. Typically, the elastic member is formed by a rubber, a spring and on, and applies elastic force on the battery.
According to this aspect, the elastic member elastically contacts with the battery mounted to the battery mount part. Accordingly, backlash of the battery due to vibration generated during the operation is prevented by biasing force of the elastic member.
According to a further aspect of the power tool of the present invention, the handle is provided such that at least its one end side in the handle extending direction is connected to the tool body, and each battery mount part is arranged on another end side of the handle in the handle extending direction. The handle preferably includes a cantilever type handle only one end of which is connected to the tool body, and a looped type handle both ends of which are connected to the tool body.
According to this aspect, the battery mounted to the battery mount part is arranged distantly from the tool bit. Therefore, when the operation is performed by contacting the tool bit with a workpiece, the battery is arranged distantly from the workpiece. Accordingly, interference by the battery with the operation by the tool bit is prevented.
According to a further aspect of the power tool of the present invention, the handle comprises a grip portion which is held by a user, and the grip portion is arranged on a driving axis line. Further, all of the battery mount parts are typically arranged on the tool body at one side in the handle extending direction.
According to this aspect, the power tool in which the grip portion of the handle is arranged on the driving axis line is provided. Thus, by applying force by a user on the grip portion on the driving axis line in order to perform the operation, the force is linearly transmitted to the tool bit. As a result, the operation is effectively performed.
According to a further aspect of the power tool of the present invention, the handle comprises a grip portion in which its one end side is connected to the tool body and a reinforcing member which connects another end side of the grip portion and the tool body. That is, the reinforcing member is separately provided from the grip portion. Thus, the reinforcing member connects a region of the tool body other than a connecting region between the tool body and the grip portion and another end side of the hand grip. In such a construction, a plurality of the battery mount parts is preferably arranged on the reinforcing member.
According to a further aspect of the power tool of the present invention, the motor is arranged such that a rotational axis of the motor is intersected with the driving axis.
According to this aspect, the power tool in which the rotational axis of the motor and the driving axis are intersected is provided.
According to a further aspect of the power tool of the present invention, the motor is arranged such that a rotational axis of the motor is paralleled to the driving axis.
According to this aspect, the power tool in which the rotational axis of the motor and the driving axis are parallel is provided.
According to a further aspect of the power tool of the present invention, said plurality of battery mount parts is formed such that the combined gravity center of a plurality of the batteries mounted to said plurality of battery mount parts is located on a plane including the driving axis and a handle central axis which extends in the handle extending direction.
According to this aspect, in a case that a front-rear direction is defined by the longitudinal direction in which the driving axis is extended, a plurality of the batteries can be balanced in weight with respect to a lateral direction crossing the front-rear direction. Accordingly, operability of the power tool is enhanced.
According to another preferable aspect of a power tool of the present invention, a power tool which drives a tool bit at least linearly on a driving axis extending in a predetermined longitudinal direction is provided. The power tool comprises a motor which drives the tool bit, a tool body which houses the motor, a handle which is connected to the tool body, and a battery mount part to which a battery for providing electric current is detachably attached. The hammering tool comprises a plurality of the battery mount parts. The handle is provided such that it extends in a handle extending direction crossing the longitudinal direction. The plurality of the battery mount parts is fixed on the tool body and undetachable from the power tool.
According to the present invention, the power tool has a plurality of battery mount parts to which batteries are detachably mounted, and the battery mount parts are fixed on the tool body and undetachable from the power tool. Especially, in the present invention, the battery is typically mounted to the battery mount part directly without an adapter. Therefore, the adapter is unnecessary compared to a power tool in which the battery is mounted via the adapter. As a result, a light-weighted power tool is provided. Further, “undetachable” is a configuration in which a part or the whole of the battery mount part is not detached easily from the tool body. Namely, it is so-called non-adapter configuration which does not have an adapter attached and detached easily. For example, it may include a configuration in which the battery mount part is formed on a region of the tool body or the handle. In other words, the present invention is characterized to form the battery mount part by means of a configuration which does not allow the battery mount part to be attached and detached freely against the power tool, or a configuration in which a free attaching and detaching of the battery mount part is prevented. In this respect, the present invention may not exclude a configuration which is capable of dismantlement of the battery mount part, however the battery mount part may be dismantled from the power tool. Further, “fixed” is a configuration in which the battery mount part is not relatively moved with respect to the tool body. For example, it may preferably include a configuration in which a part or the whole of the battery mount part is integrated with the tool body directly or indirectly. Namely, it preferably includes a configuration in which a part of the whole of the battery mount part is formed integrally with the tool body, and a configuration in which the battery mount part is fixed on the tool body by means of welding, gluing, rivet, screw and so on.
According to a further aspect of the power tool of the present invention, the battery mount part comprises a battery engaging part with which the battery is engageable and the battery mount part holds the battery by engaging the battery with the battery engaging part. Further, the battery is slid against the battery engaging part and mounted to the battery mount part.
According to this aspect, the battery is attached to the battery mount part by sliding the battery against the battery mount part. Accordingly, an attaching operation of the battery is performed easily.
According to a further aspect of the power tool of the present invention, a plurality of the battery mount parts are arranged to be aligned in a cross direction crossing both of the longitudinal direction and the handle extending direction, and each battery is attached by moving in a direction parallel to the longitudinal direction.
According to this aspect, since a plurality of the battery mount parts are arranged side by side, a compact arrangement of a plurality of the batteries is achieved. As a result, an arrangement of electric wiring with respect to the battery mount parts is simplified.

Effects of the Invention

Accordingly, an improved power tool with respect to an attaching and detaching technique of the battery is provided.
Other objects, features and advantages of the present disclosure will be readily understood after reading the following detailed description together with the accompanying drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross sectional view of whole construction of a hammer drill of a first embodiment according to the present invention.

FIG. 2 shows an enlarged view which shows an attaching state of battery packs attached to battery mount parts.

FIG. 3 shows a view when viewed along an arrow A in FIG. 1.

FIG. 4 shows a view when viewed along an arrow B in FIG. 1.

FIG. 5 shows a terminal of the battery mount part.

FIG. 6 shows a perspective view of the battery pack.

FIG. 7 shows a top view of the battery pack.

FIG. 8 shows a view when viewed along an arrow C in FIG. 6.

FIG. 9 shows a view when viewed along an arrow D in FIG. 6.

FIG. 10 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a second embodiment according to the present invention.

FIG. 11 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a third embodiment according to the present invention.

FIG. 12 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a fourth embodiment according to the present invention.

FIG. 13 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a fifth embodiment according to the present invention.

FIG. 14 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a sixth embodiment according to the present invention.

FIG. 15 shows a schematic view of the hammer drill when viewed from the rear of the hammer drill in FIG. 14.

FIG. 16 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a seventh embodiment according to the present invention.

FIG. 17 shows a schematic view of the hammer drill when viewed from the rear of the hammer drill in FIG. 16.

FIG. 18 shows a schematic view of a modified example of the hammer drill of the seventh embodiment.

FIG. 19 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a eighth embodiment according to the present invention.

FIG. 20 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a ninth embodiment according to the present invention.

FIG. 21 shows a schematic view of the hammer drill when viewed from the rear of the hammer drill in FIG. 20.

FIG. 22 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a tenth embodiment according to the present invention.

FIG. 23 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of an eleventh embodiment according to the present invention.

FIG. 24 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twelfth embodiment according to the present invention.

FIG. 25 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a thirteenth embodiment according to the present invention.

FIG. 26 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a fourteenth embodiment according to the present invention.

FIG. 27 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a fifteenth embodiment according to the present invention.

FIG. 28 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a sixteenth embodiment according to the present invention.

FIG. 29 shows a schematic view of the hammer drill when viewed from the rear of the hammer drill in FIG. 28.

FIG. 30 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a seventeenth embodiment according to the present invention.

FIG. 31 shows a schematic view of a hammer drill of an eighteenth embodiment according to the present invention.

FIG. 32 shows a partial cross sectional view of whole construction of a hammer drill of a nineteenth embodiment according to the present invention.

FIG. 33 shows a partial cross sectional view when viewed along an arrow B in FIG. 32.

FIG. 34 shows a partial cross sectional view of whole construction of a hammer drill of a twentieth embodiment according to the present invention.

FIG. 35 shows a view when viewed along an arrow E in FIG. 34.

FIG. 36 shows a partial cross sectional view when viewed from the rear side of the hammer drill (right side in FIG. 34).

FIG. 37 shows a partial cross sectional view of whole construction of a hammer drill of a twenty-first embodiment according to the present invention.

FIG. 38 shows a partial cross sectional view when viewed from the rear side of the hammer drill (right side in FIG. 37).

FIG. 39 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twenty-second embodiment according to the present invention.

FIG. 40 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twenty-third embodiment according to the present invention.

FIG. 41 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twenty-fourth embodiment according to the present invention.

FIG. 42 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twenty-fifth embodiment according to the present invention.

FIG. 43 shows a view when viewed along an arrow F in FIG. 42.

FIG. 44 shows a schematic view of a hammer drill and an arrangement of the battery packs with respect to the hammer drill of a twenty-sixth embodiment according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Each of the additional features and method steps disclosed above and below may be utilized separately or in conjunction with other features and method steps to provide and manufacture improved power tools and method for using such power tools and devices utilized therein. Representative examples of the invention, which examples utilized many of these additional features and method steps in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person skilled in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed within the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe some representative examples of the invention, which detailed description will now be given with reference to the accompanying drawings.

First Embodiment

A first embodiment of the present invention is explained below with reference to FIG. 1 to FIG. 9. The first embodiment is explained by using a battery type hammer drill as a one example of a power tool. As shown in FIG. 1, an electric hammer drill 100 to which a hammer bit 119 is attached is the power tool which performs a drilling operation or a chipping operation like that against a workpiece by causing the attached hammer bit 119 to do a hammering movement in its longitudinal direction and a rotational movement around its longitudinal direction. The hammer bit 119 is an example of a feature which corresponds to “a tool bit” in the present invention.
The hammer drill 100, in an overall view, is mainly provided with a main body 101 which forms an outline of the hammer drill 100. At a front region of the main body 101, the hammer bit 119 is detachably attached thereto via a cylindrical tool holder 159. The hammer bit 119 is inserted into a bit insertion hole of the tool holder 159 and held such that it is allowed to reciprocate in its longitudinal direction with respect to the tool holder 159 and prevented from rotating in its circumferential direction with respect to the tool holder 159.
The main body 101 is mainly provided with a motor housing 103 which houses an electric motor 110, and a gear housing 105 which houses a motion converting mechanism 120, a hammering mechanism 140 and a power transmitting mechanism 150. A hand grip 109 which is held by a user is connected to the main body 101 at a side opposite to the hammer bit 119 in the longitudinal direction of the hammer bit 119. The main body 101 is an example of a feature which corresponds to “a tool body” and the hand grip 109 is an example of a feature which corresponds to “a handle” in the present invention.
Further, in this embodiment, for the sake of convenience of explanation, with respect to the longitudinal direction of the hammer bit 119 or a longitudinal direction of the main body 101, the hammer bit 119 side is referred to as a front side of the hammer drill 100 and the hand grip 109 side is referred to as a rear side of the hammer drill 100. Furthermore, an upper side in FIG. 1 is referred to as an upper side of the hammer drill 100 and a lower side in FIG. 1 is referred to as a lower side of the hammer drill 100.
In the main body 101, the gear housing 105 is arranged in the front and the motor housing 103 is arranged in the rear in the longitudinal direction of the hammer bit 119. Further, the hand grip 109 is arranged rearward of the motor housing 103. The motor housing 103 is extended downwardly lower than a lower surface of the gear housing 105 and the electric motor 110 is arranged in this extended region. The electric motor 110 is arranged such that a rotational axis of the electric motor 110 is extended so as to incline with respect to a vertical direction and to cross a hammering axis extending in the longitudinal direction of the hammer bit 119. The electric motor 110 is an example of a feature which corresponds to “a motor” and the hammering axis is an example of a feature which corresponds to “a driving axis” in the present invention.
Namely, the hammer drill 100 according to the first embodiment is constructed such that the hammering axis of the hammer bit 119 is perpendicular to the rotational axis of the electric motor 110 and hereinafter the hammer drill having such construction is called as a first form of the hammer drill for the sake of convenience. Further, each of the motor housing 103, the gear housing 105 and the hand grip 109 which forms the main body 101 is provided by connecting left and right housing members to each other with respect to the longitudinal direction of the hammer bit 119.
Rotational output of the electric motor 110 is converted into a linear motion by the motion converting mechanism 120 and then transmitted to the hammering mechanism 140, and causes impact force in the longitudinal direction of the hammer bit 119 (lateral direction in FIG. 1) via the hammering mechanism 140. Further, the rotational output of the electric motor 110 is decelerated by the power transmitting mechanism 150 and then transmitted to the hammer bit 119, and the hammer bit 119 is rotated in its circumference direction. The electric motor 110 is energized and driven when a trigger 109 a arranged on the hand grip 109 is pulled.
The motion converting mechanism 120 is arranged above a motor shaft 111 of the electric motor 110 and the motion converting mechanism 120 converts the rotational output of the motor shaft 111 into the linear motion in a front-rear direction of the hammer drill 100. The motion converting mechanism 120 is mainly provided with an intermediate shaft 121 which is rotationally driven by the motor shaft 111, a rotation member 123 which is mounted to the intermediate shaft 121, a swing member 125 which is swung in the front-rear direction of the hammer drill 100 by rotation of the intermediate shaft 121 (rotation member 123), a cylindrical piston 127 in the form of a driving member which is reciprocated in the front-rear direction of the hammer drill 100 by swing motion of the swing member 125 and a cylinder 129 which houses the piston 127. The motor shaft 111 is arranged to incline with respect to the intermediate shaft 121. The cylinder 129 is formed integrally with the tool holder 159 as a rear part of the tool holder 159.
The hammering mechanism 140 is arranged above the motion converting mechanism 120 and rearward of the tool holder 159, and the hammering mechanism 140 transmits a linear output in the front-rear direction of the hammer drill 100, which is converted from the rotational output of the electric motor 110 by the motion converting mechanism 120, to the hammer bit 119 as a hammering force. That is, the hammering mechanism 140 is mainly provided with a striker 143 in the form of an impact element which is slidably disposed within the cylindrical piston 127, and an impact bolt 145 which is arranged frontward of the striker 143 and is collided by the striker 143. Further, an inner space rearward of the striker 143 in the piston 127 forms an air chamber 127 a which transmits slide motion of the piston 127 to the striker 143 by air pressure fluctuation.
The power transmitting mechanism 150 is arranged frontward of the motion converting mechanism 120 and the power transmitting mechanism 150 transmits the rotational output of the electric motor 110 transmitted from the intermediate shaft 121 of the motion converting mechanism 120 into the tool holder 159. That is, the power transmitting mechanism 150 is mainly provided with a gear deceleration mechanism which comprises a plurality of gears including a first gear 151 which is rotated integrally with the intermediate shaft 121, a second gear 153 which is engaged and meshed with the first gear 151 and is mounted onto the tool holder 159 (cylinder 129) and so on.
The hand grip 109 is mainly provided with a grip portion 109A which extends in a vertical direction perpendicular to the longitudinal direction of the hammer bit 119 (hammering axis extending direction). The hammering axis extending direction which is a longitudinal direction of the hammer bit 119 is an example of a feature which corresponds to “a driving axis extending direction” in the present invention. Further, the vertical direction is an example of a feature which corresponds to “a handle extending direction” in the present invention. The grip potion 109A is arranged with predetermined interval in the longitudinal direction of the hammer bit 119 with respect to an upper part of the motor housing 103. An upper part of the grip portion 109A is connected to an upper connection part 103 a which extends rearward in substantially horizontal manner from a rear-upper end region of the motor housing 103, and a lower part of the grip portion 109A is connected to a lower connection part 103 b which extends rearward in substantially horizontal manner from an intermediate region in the vertical direction of the motor housing 103. Further, in the first embodiment, as shown in FIG. 1, the upper connection part 103 a and the lower connection part 103 b are extended and formed integrally with the motor housing 103, however those parts may be extended and formed integrally with the grip portion 109A.
The lower connection part 103 b of the motor housing 103 extends rearward from substantially intermediate region in the vertical direction of the motor housing 103 and has a mount part 160 to which battery packs are mounted at its lower surface part. The mount part 160 comprises two battery mount parts 160A, 160B.
The two battery mount parts 160A, 160B are aligned next to each other in the longitudinal direction of the hammer bit 119. These two battery mount parts 160A, 160B are fixed on the lower connection part 103 b in an undetachable manner from the hammer drill 100.
Further, each battery packs 170A, 1703 for providing driving electric current to the electric motor 110 is individually detachably attached to each battery mount parts 160A, 160B, respectively. The two battery mount parts 160A, 160B is an example of a feature which corresponds to “a plurality of batter mounting parts” in the present invention, and the battery pack 170A, 170B is an example of a feature which corresponds to “a battery” in the present invention. In FIG. 1 to FIG. 4, the battery packs 170A, 170B are illustrated by a chain double-dashed line.
Furthermore, an inner space is formed within the lower connection part 103 b and a controller 130 for controlling the electric motor 110 is provided at the inner space. That is, the controller 130 is, as shown in FIG. 1, arranged between the battery packs 170A, 170B and the hand grip 109. In other words, the controller 130 is horizontally arranged above the battery packs 170A, 170B. Further, as shown by the chain double-dashed line in FIG. 1, the controller 130 may be arranged rearward of the electric motor 110 between the battery packs 170A, 170B and the electric motor 110.
FIG. 6 to FIG. 9 show the details of the battery pack 170A, 170B (FIG. 6 to FIG. 9 show one battery pack). The battery pack 170A, 170B is mainly provided with a substantially rectangular parallelepiped battery case 171 and a plurality of battery cells (not shown) which are housed in the battery case 171. The battery pack 170A, 170B is detachably mounted to the each battery mount part 160A, 160B by horizontally sliding along a lower surface of the each battery mount part 160A, 160B in a lateral direction which crosses both of the longitudinal direction of the hammer bit 119 and the extending direction of the hand grip 109. Further, each of two battery packs 170A, 170B has the same construction (configuration) and attachable to both of two battery mount parts 160A, 160B.
In order to slide the battery pack 170A, 170B against the battery mount part 160A, 160B, each of pair of mount guides 173 which extends in a longitudinal direction of the battery pack 170A, 170B is provided on each side surface of an upper side of the battery case 171. Further, a hook 175 for locking and a press button 177 for unlocking are provided at a center part of the upper side. The hook 175 for locking is provided at a rear side part with respect to an attaching direction of the battery pack 170A, 170B (sliding direction while attaching) and is biased by a spring (not shown) such that it protrudes from an upper surface of the battery case 171. The press button 177 for unlocking is provided at rear side part with respect to the attaching direction of the battery case 171 (a sliding direction while attaching). Further, the press button 177 is mechanically linked with the hook 175 such that when a user presses the press button 177, the hook 175 is moved in a direction in which the hook 175 is pulled down from the upper surface of the battery case 171.
On the other hand, as shown in FIG. 1 and FIG. 2, in each battery mount part 160A, 160B, a front and rear pair of guide rails 161 which extend in a lateral direction crossing the longitudinal direction of the hammer bit 119 (hammering axis) is provided, respectively, in order to mount the battery pack 170A, 170B from a side of the hammer drill 100.
The guide rails 161 are formed integrally with the lower connection part 103 b. The guide rails 161 form substantially U-shaped section in the lateral direction and one end in an extending direction of the guide rails 161 is opened as an insertion opening for the mount guide 173. Further, the mount guide 173 of the battery pack 170A, 170B is slid against the guide rails 161 in a direction crossing both of the longitudinal direction of the hammer bit 119 and the extending direction of the hand grip 109 and inserted.
That is, the guide rail 161 has a function as a guide mean while mounting the battery pack 170A, 170B to the battery mount part 160A, 160B and a function as a falling preventing mean to prevent the battery pack 170A, 170B from falling off the battery mount part 160A, 160B. The guide rail 161 is an example of a feature which corresponds to “a battery engaging part” in the present invention.
Further, as shown in FIG. 4, each battery mount part 160A, 160B comprises a recessed engagement part 163 with which the hook 175 of the battery pack 170A, 170B can engage. The engagement part 163 is arranged between the front and rear guide rails 161 at a battery inserted side. Accordingly, when the battery pack 170A, 170B is mounted to the battery mount part 160A, 160B, the engagement part 163 is engaged with the hook 173. Therefore, the battery pack 170A, 170B is fixed on the battery mount part 160A, 160B and to move in a detaching direction (a direction opposite to the sliding direction while attaching) or to fall off of the battery pack 170A, 170B is prevented. Further, when mounting the battery pack 170A, 170B to the battery mount part 160A, 160B, a tapered part of the hook 173 is pressed by the engagement part 163 and once moved downward, and thereafter the hook 173 engages with the engagement part 163 by returning to its initial position.
Each battery pack 170A, 170B mounted to each battery mount part 160A, 160B is held such that an outer surface except an upper surface as a mounting surface mounted to the battery mount part 160A, 160B is exposed. Further, a lower surface of the battery pack 170A, 170B is formed flush with a lower surface of the motor housing 103. With such a construction, the lower surfaces of the battery pack 170A, 170B and the motor housing 103 are formed as a placement surface and thereby the hammer drill 100 is stably placed on the ground or a floor.
As described above, the battery pack 170A, 170B is arranged rearward of the electric motor 110 and below the hand grip 109 such that the longitudinal direction of the battery pack 170A, 170B is parallel to a crossing direction which crosses both of the longitudinal direction of the hammer bit 119 and the handgrip extending direction. Two battery packs 170A, 170B are arranged side by side in the front-rear direction (longitudinal direction of the hammer bit 119). That is, the battery pack 170A, 170B is mounted to the battery mount part 160A, 160B such that its length in the longitudinal direction of the hammer bit 119 is shorter than its length in a direction crossing the longitudinal direction of the hammer bit 119.
Further, in the first embodiment, with respect to two batter pack 170A, 170B, when viewed from the rear of the hammer drill 100, an attaching direction of the battery pack 170A, 170B is defined by a moving (sliding) direction from a left side to a right side of the hammer drill 100 (a direction shown by an arrow F in FIG. 3 and FIG. 4), while a detaching direction of the battery pack 170A, 170B is defined by an opposite moving direction. That is, in the first embodiment, the attaching/detaching direction of the battery pack 170A and the attaching/detaching direction of the battery pack 170B are the same direction to each other. Further, as a modified example, the attaching/detaching direction of one battery pack 170A and that of another battery pack 170B may be defined as different directions to each other. Namely, when viewed from the rear of the hammer drill 100, one battery pack 170A may be attached from the right side of the hammer drill 100 and another battery pack 170B may be attached from the left side of the hammer drill 100.
Further, each battery mount part 160A, 160B has a terminal 165 (refer to FIG. 5). The terminal 165 is arranged between a pair of the front and rear guide rails 161 in each battery mount part 160A, 160B and fixed on the lower surface of the lower connection part 103 b.
Further, when the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B, each terminal 179 (refer to FIG. 6 and FIG. 7) of the battery packs 170A, 170B is electrically connected to each terminal 165 which is formed on a lower surface of each battery mount parts 160A, 160B (refer to FIG. 5), and thereby it makes possible to provide electric current to the electric motor 110 and the controller 130.
Further, as shown in FIG. 3, at the lower surface of each battery mount part 160A, 160B, four cylindrical rubber pins 167 are provided such that each of them are arranged at each corners of a virtual rectangle. These four rubber pins 167 protrude downward at a predetermined length and elastically bias four points downwardly on an upper surface of the battery pack 170A, 170B which is mounted to the battery mount part 160A, 160B. With such a construction, shakiness of the battery pack 170A, 170B due to vibration is prevented. The rubber pin 167 is an example of a feature which corresponds to “an elastic member” in the present invention. Furthermore, the rubber pin 167 may be formed other than the cylindrical shape, and alternatively a spring element such as a flat spring like that may be utilized instead of the rubber pin 167.
As described above, according to the first embodiment, the battery mount parts 160A, 160B are provided at two parts as front and rear on the lower connection part 103 b of the motor housing 103, and each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. Therefore, for example, in the hammer drill 100 of 36V specification, two 18V battery packs 170A, 170B are mounted and electrically connected in series. The 18V battery pack has light weight much more compared to a 36V battery pack. Accordingly, a user can perform a replacing operation of the battery pack 170A, 170B or an attaching/detaching operation of the battery pack 170A, 170B to/from the battery mount part 160A, 160B easily. As a result, usability of the attaching/detaching operation of the battery pack 170A, 170B is improved. Further, in the hammer drill 100 of 18V specification, two 18V battery packs 170A, 170B are electrically connected in parallel. In such a case, a long-term driving of the hammer drill 100 becomes possible. Further, in the hammer drill 100 of 36V/18V specification, a connecting mode of the battery packs 170A, 170B may be switched between in series mode and in parallel mode. In such a case, a switching switch which is operated by a user to switch the connecting mode may preferably be provided.
Further, according to the first embodiment, two battery mount parts 160A, 160B are provided and fixed on the lower connection part 103 b of the motor housing 103, and the battery packs 170A, 170B are mounted to these battery mount parts 160A, 160B. That is, two battery packs 170A, 170B are mounted directly to the battery mount parts 16A, 160B without an adapter. Accordingly, when mounting a plurality of battery packs, the adapter is not required compared to a construction in which a plurality of the battery packs are mounted to a single battery mount part via an adapter and thereby light-weighting of the hammer drill 100 is achieved.
Furthermore, the battery pack 170A, 170B is generally formed as a substantially rectangular parallelepiped shape. According to the first embodiment, the 18V battery packs 170A, 170B are aligned in the front-rear direction and arranged on the lower connection part 103 b of the motor housing 103 such that those longitudinal directions are perpendicular to the longitudinal direction of the hammer bit 119. That is, when the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B, each battery pack 170A, 170B is arranged such that its length in the longitudinal direction of the hammer bit 119 is shorter than its length in a direction crossing the longitudinal direction. With such a construction, length of an arrangement space of the battery pack 170A, 170B in the longitudinal direction of the hammer bit 119 becomes shorter compared to a construction in which the longitudinal direction of the battery packs 170A, 170B is parallel to the longitudinal direction of the hammer bit 119. Accordingly, a compact-shaped the hammer drill 100 in which its length in the front-rear direction is shortened is constructed.
Further, according to the first embodiment, the battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting into the battery mount part 160A, 160B from the side of the hammer drill 100. Therefore, in the battery pack 170A, 170B, the detaching direction of the battery pack 170A, 170B crosses the hammering axis of the hammer bit 119 or a direction of vibration generated by the hammering movement of the hammer bit 119. Accordingly, the detaching direction of the battery pack 170A, 170B does not mate with the vibration direction of the hammer drill 100, and a possibility of falling of the battery pack 170A, 170B due to the vibration of the hammer drill 100 is reduced.
Further, according to the first embodiment, the battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by sliding the mount guide 173 of the battery pack 170A, 170B along the guide rail 161 of the battery mount part 160A, 160B. Accordingly, the battery pack 170A, 170B is easily mounted.
Further, according to the first embodiment, the battery pack 170A, 170B is arranged rearward of the motor housing 103 and below the hand grip 109. In the first form of the hammer drill 100, due to structural characteristics in which a region of the motor housing 130 which houses the electric motor 110 is extended downward, a free space is provided rearward of the downward extending region which is below the hand grip 109. Therefore, since the battery packs 170A, 170B are arranged by utilizing the free space, the battery packs 170A, 170B are rationally arranged. Further, such a position of the battery packs 170A, 170B is remote from an operation point by the hammer bit 119, and thereby the battery packs 170A, 170B do not interfere with the working operation.
Further, according to the first embodiment, the battery packs 170A, 170B are arranged rearward of the motor housing 103 and below the hand grip 109, and the lower surface of the battery packs 170A, 170B is formed flush with the lower surface of the motor housing 103. Therefore, when the hammer drill 100 is placed on the ground or the floor, the hammer drill 100 is stably placed. Further, in the first embodiment, the hammering axis of the hammer bit 119 and the rotational axis of the electric motor 110 are inclined with each other, however it is not limited to this. For example, the electric motor 110 may be arranged such that the hammering axis of the hammer bit 119 and the rotational axis of the electric motor 110 are perpendicularly intersected to each other.
Further, according to the first embodiment, two battery mount parts 160A, 160B are arranged side by side. Accordingly, an arrangement of electric wiring connected to respective terminals 165 of the battery mount parts 160A, 160B to which the battery 170A, 170B is electrically connected is simplified.

Second Embodiment

Next, a second embodiment is explained with reference to FIG. 10. As shown in FIG. 10, in the second embodiment, the electric motor 110 is arranged such that the rotational axis of the electric motor 110 is parallel to the hammering axis of the hammer bit 119. In addition, the grip portion 109A of the hand grip 109 is arranged on the hammering axis line. The hammer drill 100 according to the second embodiment is called as a second form of the hammer drill, for the sake of convenience. The hand grip 109 extends from a rear-upper end region of the motor housing 103 downwardly and crosses the longitudinal direction of the hammer bit 119. A tip end of the grip portion 109A and a rear-lower end region of the motor housing 103 are connected by a support member 107 for reinforcing the hand grip, which is extended so as to incline against an up-and-down direction (vertical direction). That is, the hand grip 109 comprises the grip portion 109A and the support member 107. The support member 107 is an example of a feature which corresponds to “a reinforcing member” in the present invention. Rotation of the electric motor 110 is converted into a linear motion by the motion converting mechanism 120 and then transmitted to the hammer bit 119 held by the tool holder 159 via the hammering mechanism 140 as impact force. Furthermore, the rotation of the electric motor 110 is transmitted to the hammer bit 119 held by the tool holder 159 via the power transmitting mechanism 150 as rotational motion.
In the second form of the hammer drill 100 described above, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 on the lower surface of the tip end of the grip portion 109A and the support member 107. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100. Thus, according to the second embodiment, in the second form of the hammer drill 100, similar advantage described in the first embodiment is obtained.

Third Embodiment

Next, a third embodiment is explained with reference to FIG. 11. According to the third embodiment, in the second form of the hammer drill 100, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 so as to be astride both lower surfaces of the motor housing 103 and the gear housing 105. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100. Thus, according to the third embodiment, in the second form of the hammer drill 100, similar advantage described in the first embodiment is obtained.

Fourth Embodiment

Next, a fourth embodiment is explained with reference to FIG. 12. As shown in FIG. 12, in the fourth embodiment, the grip portion 109A of the hand grip 109 is provided so as to extend from a lower region of the rear end side part of the motor housing 103 downwardly and crosses the longitudinal direction of the hammer bit 119. The hammer drill 100 according to the fourth embodiment is called as a third form of the hammer drill, for the sake of convenience.
In the third form of the hammer drill 100 described above, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 on the lower surface of the hand grip 109 which is formed as the tip end (free end) of the hand grip 109. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100. Thus, according to the fourth embodiment, in the third form of the hammer drill 100, similar advantage described in the first embodiment is obtained.

Fifth Embodiment

Next, a fifth embodiment is explained with reference to FIG. 13. As shown in FIG. 13, in the fifth embodiment, in addition to the third form of the hammer drill described above, the tip end of the grip portion 109A and a lower region of the front end side part of the motor housing 103 are connected by the support member 107 for reinforcing the hand grip, which is extended so as to incline against an up-and-down direction (vertical direction). That is, the hand grip 109 comprises the grip potion 109A and the support member 107. The hammer drill 100 according to the fifth embodiment is called as a fourth form of the hammer drill, for the sake of convenience. The support member 107 is an example of a feature which corresponds to “a reinforcing member” in the present invention.
In the fourth form of the hammer drill 100, two battery mount parts 160A, 160B are provided and aligned in the vertical direction on a front surface region of the support member 107 (on the support member 107). Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100. Thus, according to the fifth embodiment, in the fourth form of the hammer drill 100, similar advantage described in the first embodiment is obtained.
Further, following modified examples other than the first through fifth embodiments may be provided, however illustrations of which are omitted for the sake of convenience.

First Modified Example

In the first form of the hammer drill 100, the lower surface of the lower connection part 103 b which connects the motor housing 103 and the hand grip 109 may be formed flush with the lower surface the motor housing 103, and two battery mount parts 160A, 160B may be provided on the lower surface of the motor housing 103 and/or the lower connecting part 103 b and aligned in the longitudinal direction of the hammer bit 119. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Second Modified Example

In the second form of the hammer drill 100, one battery mount part 160A may be provided on the lower surface of the tip end of the grip portion 109A and the support member 107, and another battery mount part 16013 may be provided so as to be astride both lower surfaces of the motor housing 103 and the gear housing 105. The lower surfaces of the motor housing 103 and the gear housing 105 are formed flush with each other. With such a construction, two battery mount parts 160A, 160B are provided distantly from each other. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Third Modified Example

In the second form of the hammer drill 100, one battery mount part 160A may be provided on the lower surface of the grip portion 109A and the support member 107, and another battery mount part 160B may be provided on the upper surface of the grip portion 109A. That is, two battery mount parts 160A, 160B are provided distantly from each other. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Fourth Modified Example

In the third form of the hammer drill 100, one battery mount part 160A may be provided on the lower surface of the hand grip 109 which is formed as the tip end (free end) of the hand grip 109, an another battery mount part 160B may be provided so as to be astride both lower surfaces of the motor housing 103 and the gear housing 105. That is, two battery mount parts 160A, 160B are provided distantly from each other. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Fifth Modified Example

In the third form of the hammer drill 100, two battery mount parts 160A, 160B may be provided on the upper surface of the rear region of the motor housing 103 and aligned in the longitudinal direction of the hammer bit 119. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Sixth Modified Example

In the fourth form of the hammer drill 100, two battery mount parts 160A, 160B may be provided on the tip end of the hand grip 109 (lower surface of the hand grip 109) and aligned in the longitudinal direction of the hammer bit 119. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 1703 is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 1603 in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Seventh Modified Example

In the fourth form of the hammer drill 100, one battery mount part 160A may be provided on the lower surface of hand grip 109 and another battery mount part 160B may be provided on the front surface of the support member 107. That is, two battery mount parts 160A, 160B are provided distantly from each other. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Eighth Modified Example

In the fourth form of the hammer drill 100, two battery mount parts 160A, 160B may be provided on the lower surface of the gear housing 105 and aligned in the longitudinal direction (front-rear direction) of the hammer bit 119. Further, each battery pack 170A, 170B is detachably mounted to each battery mount part 160A, 160B. The battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by inserting (sliding) into the battery mount part 160A, 160B in a direction crossing the longitudinal direction of the hammer bit 119 from the side of the hammer drill 100.

Sixth Embodiment

Next, a sixth embodiment is explained with reference to FIG. 14 and FIG. 15. According to the sixth embodiment, in the first form of the hammer drill 100, two battery mount parts 160A, 160B are arranged on the lower surface of the lower connection part 103 b which connects the motor housing 103 and the hand grip 109 such that the battery mount parts 160A, 160B are aligned in a direction crossing both of the longitudinal direction of the hammer bit 119 and the extending direction of the hand grip 109. In addition, the battery packs 170A, 170B are attached and detached to/from two battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B against the battery mount parts 160A, 160B parallel to the longitudinal direction of the hammer bit 119.
Namely, the battery pack 170A, 170B is attached to the battery mount part 160A, 160B by moving the battery pack 170A, 170B in a direction from rear to front of the hammer drill 100, while the battery pack 170A, 170B is detached from the battery mount part 160A, 160B by moving the battery pack 170A, 170B in an opposite direction (from front to rear of the hammer drill 100). Further, construction other than above is similar to that of the first embodiment. According to the sixth embodiment, the same advantage as the first embodiment is obtained.

Seventh Embodiment

Next, a seventh embodiment is explained with reference to FIG. 16 and FIG. 17. According to the third embodiment, in the first form of the hammer drill 100, the battery mount parts 160A, 160B are provided on side surfaces of a vertical wall 103 c which extends downwardly. The vertical wall 103 c is formed integrally with the lower connection part 103 b at a lower-center part of the lower connection part 103 b. Further, the battery mount parts 160A, 160B are provided on right and left side surfaces of the vertical wall 103 c, respectively. That is, two battery mount parts 160A, 160B are arranged at right side and left side separately via the vertical wall 103 c. Further, the battery pack 170A, 170B is attached to and detached from the battery mount part 160A, 160B by moving (sliding) the battery pack 170A, 170B against the battery mount part 160A, 160B in the front-rear direction (longitudinal direction of the hammer bit 119). Further, construction other than above is similar to that of the first embodiment.
According to the seventh embodiment, when the hammer drill 100 is placed on the ground and so on, the vertical wall 103 c is utilized as a stand (pedestal). In such a case, a lower surface of the vertical wall 103 c is preferably formed flush with a lower surface of the attached battery packs 170A, 170B. Accordingly, when the hammer drill 100 is placed on the ground or a floor, the hammer drill 100 is stably placed. Further according to the seventh embodiment, the same advantage as the first embodiment is obtained.
Further, in the seventh embodiment, as shown in FIG. 18, small-size and small-capacity battery pack 170A, 170 b compared to the battery packs 170A, 170B shown in FIG. 17 may be utilized. For example, in the battery pack of 18V specification, capacity of normal-size (large-capacity) battery pack shown in FIG. 17 is 3 Ah (ampere-hour), while capacity of the small-sized battery pack is 1.3 Ah. The small-sized light- weight battery pack 170A, 170B is, as shown in FIG. 18, shortened its depth compared to the battery pack shown in FIG. 17. Accordingly, the small- sized battery pack 170A, 170B is formed as a rectangular parallelepiped having the same width and length other than the depth as the normal-size battery pack. Therefore, even when the small-size battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B provided on the right-side and left-side surfaces of the vertical wall 103, the lower surface of the battery packs 170A, 170B mounted to the battery mount parts 160A, 160B are formed flush with the lower surface of the vertical wall 103 c. Accordingly, when the hammer drill 100 is placed on the ground or a floor, the hammer drill 100 is stably placed.

Eighth Embodiment

Next, an eighth embodiment is explained with reference to FIG. 15. As shown in FIG. 19, in the eighth embodiment, the electric motor 110 is arranged such that the rotational axis of the electric motor 110 is parallel to the hammering axis of the hammer bit 119. In addition, the grip portion 109A of the hand grip 109 is arranged on the hammering axis line. The hand grip 109 is mainly provided with the grip portion 109A and a support member 107. The grip portion 109A extends from a rear-upper end region of the motor housing 103 downwardly and crosses the longitudinal direction of the hammer bit 119. The support member 107 connects the tip end of the grip portion 109A in its extending direction and a rear-lower end region of the motor housing 103. The support member 107 is extended so as to incline against the vertical direction, and is provided to reinforce the hand grip 109A. Rotation of the electric motor 110 is converted into a linear motion by the motion converting mechanism 120 and then transmitted to the hammer bit 119 held by the tool holder 159 via the hammering mechanism 140 as impact force. Furthermore, the rotation of the electric motor 110 is transmitted to the hammer bit 119 held by the tool holder 159 via the power transmitting mechanism 150 as rotational motion.
In the eighth embodiment, in the second form of the hammer drill 100 described above, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 on the lower surface of the tip end of the grip portion 109A and the support member 107. Further, the battery pack 170A is mounted to the battery mount part 160A by moving toward rear side of the hammer drill 100. In other words, the battery pack 170A is mounted to the battery mount part 160A by moving in a direction close to the rear side battery mount part 160B. On the other hand, the battery pack 170B is mounted to the battery mount part 160B by moving toward front side of the hammer drill 100. In other words, the battery pack 170B is mounted to the battery mount part 160B by moving in a direction close to the front side battery mount part 160A. Further, each battery pack 170A, 170B is detached by moving in a direction opposite to each attaching direction. Further, construction other than above is similar to that of the first embodiment.
According to the eighth embodiment, two battery mount parts 160A, 160B is constructed such that the battery packs 170A, 170B mounted to respective battery mount parts 160A, 160B are arranged face to face in the longitudinal direction of the hammer bit 119. Further, as the longitudinal direction of two battery packs 170A, 170B is parallel to the longitudinal direction of the hammer bit 119, to protrude of the battery packs 170A, 170B from the side of the main body 101 is prevented. Further, according to the eighth embodiment, substantially same advantage as the first embodiment is obtained.

Ninth Embodiment

Next, a ninth embodiment is explained with reference to FIG. 20 and FIG. 21. As shown in FIG. 20 and FIG. 21, in the ninth embodiment, the grip portion 109A of the hand grip 109 extends from a rear end region of the motor housing 103 downwardly and crosses the longitudinal direction of the hammer bit 119.
In the ninth embodiment, in the third form of the hammer drill 100 described above, the battery mount parts 160A, 160B are arranged on right and left side surfaces of the motor housing 103 in a rear region of the motor housing 103 in the longitudinal direction of the hammer bit 119. That is, two battery mount parts 160A, 160B are arranged at two points of right and left of the motor housing 103 separately via the motor housing 103. Further, the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B from rear side to front side of the hammer drill 100, and the battery packs 170A, 170B are detached from the battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B from front side to rear side of the hammer drill 100. Further, construction other than above is similar to that of the first embodiment.
According to the ninth embodiment, the battery packs 170A, 170B are arranged on the both side of the hammering axis of the hammer big 119. Therefore, the gravity center of the hammer drill 100 is arranged proximal to the hammering axis in the vertical direction crossing the longitudinal direction of the hammer bit 119. Thus, moment around the gravity center of the hammer drill 100 during the hammering operation by the hammer bit 119 is reduced. Further, according to the ninth embodiment, substantially same advantage as the first embodiment is obtained.

Tenth Embodiment

Next, a tenth embodiment is explained with reference to FIG. 22. As shown in FIG. 22, in the tenth embodiment, in the fourth form of the hammer drill 100, one battery mount part 160A is arranged on the lower end part of the grip portion 109A as a tip end of the hand grip 109, and another battery mount part 160B is arranged on the front surface of the support member 107. That is, two battery mount parts 160A, 160B are arranged separately in the front-rear direction via the hand grip 109. Further, one battery pack 170A is moved from rear to front of the hammer drill 100 and mounted to one battery mount part 170A. Further, another battery pack 170B is moved from lower to upper of the hammer drill 100 and mounted to another battery mount part 170B. Further, construction other than above is similar to that of the first embodiment.
According to the tenth embodiment, two battery packs 170A, 170B are rationally arranged at mutually separated two points by utilizing the grip portion 109A of the hand grip 109 and the support member 107. Further, according to the tenth embodiment, substantially same advantage as the first embodiment is obtained.

Eleventh Embodiment

Next, an eleventh embodiment is explained with reference to FIG. 23. In the eleventh embodiment, in the first form of the hammer drill 100, the lower surface of the lower connection part 103 b which connects the motor housing 103 and the hand grip 109 is formed as a non-stepped planar shape.
Further, in FIG. 23, the electric motor 110 is arranged such that the rotational axis of the electric motor 110 is perpendicular to the driving axis of the hammer bit 119, however the electric motor 110 may be arranged such that the rotational axis of the electric motor 110 is inclined against the vertical direction and intersected with the driving axis of the hammer bit 119.
Further, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 (front-rear direction) on the lower surface of the lower connection part 103 b. Further, the battery pack 170A is mounted to one battery mount part 160A by moving (sliding) the battery pack 170A in a direction close to another battery mount part 160B. On the other hand, the battery pack 170B is mounted to another battery mount part 160B by moving (sliding) the battery pack 170B in a direction close to one battery mount part 160A. That is, the battery pack 170A is mounted to the battery mount part 160A by sliding against the battery mount part 160A in a direction of an arrow 11A. On the other hand, the battery pack 170B is mounted to the battery mount part 160B by sliding against the battery mount part 160B in a direction of an arrow 11B. The directions of the arrows 11A and 11B are parallel to a driving axis extending direction in which the driving axis of the hammer bit 119 is extended. Further, construction other than above is similar to that of the first embodiment.
According to the eleventh embodiment, in the first form of the hammer drill 100, two battery mount parts 160A, 160B are rationally arranged by utilizing the lower surfaces of the motor housing 103 and the hand grip 109. Further, according to the eleventh embodiment, substantially same advantage as the first embodiment is obtained.

Twelfth Embodiment

Next, a twelfth embodiment is explained with reference to FIG. 24. In the twelfth embodiment, in the third form of the hammer drill 100, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 (front-rear direction) on the lower surface of the tip end of the hand grip 109. Further, the battery pack 170A is mounted to one battery mount part 160A by moving (sliding) the battery pack 170A in a direction close to another battery mount part 160B. On the other hand, the battery pack 170B is mounted to another battery mount part 160B by moving (sliding) the battery pack 170B in a direction close to one battery mount part 160A. Further, construction other than above is similar to that of the first embodiment.
According to the twelfth embodiment, in the third form of the hammer drill 100, two battery mount parts 160A, 160B are rationally arranged by utilizing the lower surface of the tip end of the hand grip 109. Further, according to the twelfth embodiment, substantially same advantage as the first embodiment is obtained.

Thirteenth Embodiment

Next, a thirteenth embodiment is explained with reference to FIG. 25. In the thirteenth embodiment, in the fourth form of the hammer drill 100, a lower surface of the grip portion 109A of the hand grip 109 and a lower surface of the support member 107 which connects the tip end of the grip portion 109A and the motor housing 103 are formed as a single flat surface. Further, two battery mount parts 160A, 160B are provided and aligned in the longitudinal direction of the hammer bit 119 (front-rear direction) on the flat surface. Further, the battery pack 170A is mounted to one battery mount part 160A by moving (sliding) the battery pack 170A in a direction close to another battery mount part 160B. On the other hand, the battery pack 170B is mounted to another battery mount part 160B by moving (sliding) the battery pack 170B in a direction close to one battery mount part 160A. Further, construction other than above is similar to that of the first embodiment.
According to the thirteenth embodiment, in the fourth form of the hammer drill 100, two battery mount parts 160A, 160B are rationally arranged by utilizing the lower surfaces of the grip portion 109A and the support member 107. Further, according to the thirteenth embodiment, substantially same advantage as the first embodiment is obtained.

Fourteenth Embodiment

Next, a fourteenth embodiment is explained with reference to FIG. 26. In the fourteenth embodiment, in the first form of the hammer drill 100, one battery mount part 160A is arranged on the lower surface of the lower connection part 103 b which connects the motor housing 103 and the handgrip 109. On the other hand, another battery mount part 160B is arranged on a front surface of the lower region of the motor housing 103. That is, two battery mount parts 160A, 160B are separately arranged via the motor housing 103. Further, the battery pack 170A is mounted to one battery mount part 160A by moving (sliding) the battery pack 170A in a direction parallel to the longitudinal direction of the hammer bit 119. On the other hand, the battery pack 170B is mounted to another battery mount part 160B by moving (sliding) the battery pack 170B in the vertical direction of the hammer drill 100. That is, the battery pack 170A is mounted to the battery mount part 160A by sliding against the battery mount part 160A in a direction of an arrow 24A. On the other hand, the battery pack 170B is mounted to the battery mount part 160B by sliding against the battery mount part 160B in a direction of an arrow 24B. Further, the directions of the arrows 24A and 24B are parallel to a virtual plane including the driving axis of the hammer bit 119 and an extending axis in which the grip portion 109A of the hand grip 109 is extended. The direction of the arrow 24A and the direction of the arrow 24B are intersected with each other. Accordingly, a longitudinal direction of the battery pack 170A mounted to the battery mount part 160A and a longitudinal direction of the battery pack 170B mounted to the battery mount part 160B are intersected with each other. Further, construction other than above is similar to that of the first embodiment.
According to the fourteenth embodiment, in the first form of the hammer drill 100, two battery mount parts 160A, 160B are rationally arranged by utilizing the lower surface of the lower connection part 103 b and the front surface of the lower region of the motor housing 103. Further, according to the fourteenth embodiment, substantially same advantage as the first embodiment is obtained.

Fifteenth Embodiment

Next, a fifteenth embodiment is explained with reference to FIG. 27. In the fifteenth embodiment, in the second form of the hammer drill 100, one battery mount part 160A is arranged on the lower surface of the tip end of the grip part 109A and the support member 107, and another battery mount part 160B is arranged on the lower surface of the motor housing 103. That is, two battery mount parts 160A, 160B are separately arranged in the front-rear direction via the motor housing 103 and the hand grip 109. Further, the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B respectively by moving (sliding) the battery packs 170A, 170B in a direction parallel to the longitudinal direction of the hammer bit 119. Further, construction other than above is similar to that of the first embodiment.
According to the fifteenth embodiment, in the second form of the hammer drill 100, two battery mount parts 160A, 160B are rationally arranged by utilizing the lower surface of the tip end of the grip portion 109A and the support member 107 and a part of the motor housing 103. Further, according to the fifteenth embodiment, substantially same advantage as the first embodiment is obtained.

Sixteenth Embodiment

Next, a sixteenth embodiment is explained with reference to FIG. 28 and FIG. 29. In the sixteenth embodiment, in the second form of the hammer drill 100, the battery mount parts 160A, 160B are arranged on the right and left side surfaces of the motor housing 103 and the gear housing 105 so as to be astride both of the motor housing 103 and the gear housing 105. That is, two battery mount parts 160A, 160B are separately arranged on two points of the right and left side surfaces via the motor housing 103 and the gear housing 105. Further, the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B in a direction from rear to front of the hammer drill 100 and detached from the battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B in a direction from front to rear of the hammer drill 100. Further, construction other than above is similar to that of the first embodiment.
According to the sixteenth embodiment, the battery packs 170A, 170B are arranged on the both side of the hammering axis of the hammer big 119. Therefore, the gravity center of the hammer drill 100 is arranged proximal to the hammering axis in the vertical direction crossing the longitudinal direction of the hammer bit 119. Thus, moment around the gravity center of the hammer drill 100 during the hammering operation by the hammer bit 119 is reduced. Further, according to the sixteenth embodiment, substantially same advantage as the first embodiment is obtained.

Seventeenth Embodiment

Next, a seventeenth embodiment is explained with reference to FIG. 30. In the seventeenth embodiment, in the third form of the hammer drill 100, one battery mount part 160A is arranged on the tip end of the hand grip 109 and another battery mount part 160B is arranged on the lower surfaces of the motor housing 103 and the gear housing 105. The lower surface of the motor housing 103 is formed flush with the lower surface of the gear housing 105. Therefore, two battery mount parts 160A, 160B are separately arranged via the motor housing 103 and the gear housing 105. Further, the battery packs 170A, 170B are mounted to the battery mount parts 160A, 160B by moving (sliding) the battery packs 170A, 170B in the longitudinal direction of the hammer bit 119 against two battery mount parts 160A, 160B.

Eighteenth Embodiment

Next, an eighteenth embodiment is explained with reference to FIG. 31. In the eighteenth embodiment, the battery packs 170A, 170B which are mounted to the lower surface of the lower connection part 103 so as to be aligned in the front-rear direction are covered by a rotatable cover member 180. The cover member 180 is made of elastomer and the cover member 180 is a boxed member formed as substantially rectangular parallelepiped having opened upper and front surfaces. A front-rear part of the cover member 180 is mounted to the motor housing 103 via a support shaft 181 in a rotatable manner. Accordingly, the cover member 180 is rotated upward and thereby the whole of the battery packs 170A, 170B is covered by the cover member 180 as illustrated by a solid line in FIG. 31. On the other hand, the cover member 180 is rotated downward and thereby the battery packs 170A, 170B are exposed as illustrated by a chain double-dashed line in FIG. 31. Thus, to detach the battery packs 170A, 170B is allowed. Further, the cover member 180 comprises an engagement recess 183 and when the cover member 180 is rotated upward, the engagement recess 183 is engaged with an engagement protrusion 185 formed at a rear end part of the lower connection part 103 b. Accordingly, the cover member 180 is held in its closed position.
According to the eighteenth embodiment, the battery packs 170A, 170B mounted on the lower surface of the lower connection part 103 b are covered by the cover member 180. With such a construction, a dust proof effect and a water proof effect with respect to the battery pack 170A, 170B are obtained. In addition, an inadvertent falling of the battery packs 170A, 170B is prevented by the cover member 180. Furthermore, the cover member 180 protects the battery packs 170A, 170B from the external force.
In the eighteenth embodiment, the cover member 180 is mounted to the motor housing 103 in an undetachable manner, however it is not limited to this. For example, the cover member 180 may be mounted to the motor housing 103 in a detachable manner. In such a case, the cover member may be attached to a plurality of the battery packs and thereby the plurality of the battery packs is integrated. That is, the plurality of the battery packs is disposed inside the cover member and thereby an assembly of the plurality of the battery packs and the cover member is formed. In this assembly, the terminals and the mount guides of the plurality of the battery packs are exposed from the cover member for mounting to the battery mount parts. Further, when the assembly is mounted to the battery mount parts, the cover member is contacted with the battery mount parts. With such a construction, the battery packs are sealed by the cover member.
As described above, in an aspect to form the assembly, the cover member is attached and detached as needed. Further, the plurality of the battery packs are attached to the battery mount parts by a single attaching operation. Further, the plurality of the battery packs detached from the hammer drill is integrally held. Accordingly, missing of the battery packs is prevented.
Further, the cover member 180 may be applicable to a hammer as a hammering tool other than the hammer drill 100. Further, apart from the hammering tool, the present invention is applicable to a power tool such as an electric driver, an electric wrench, an electric grinder, an electric reciprocating saw, an electric jigsaw and so on to which a plurality of battery packs can be mounted.

Nineteenth Embodiment

Next, a nineteenth embodiment is explained with reference to FIG. 32 and FIG. 33. In the nineteenth embodiment, with respect to two of the front and rear battery mount parts 160A, 160B, when viewed from the rear of the hammer drill 100, an attaching direction of the battery pack 170A, 170B is defined by a moving (sliding) direction from a left side to a right side of the hammer drill 100 (a direction shown by an arrow F in FIG. 32 and FIG. 33), while a detaching direction of the battery pack 170A, 170B is defined by its opposite moving direction. That is, respective battery packs 170A, 170B are mounted to two of the front and rear battery mount parts 160A, 160B by moving in the same direction to each other.
Further, two of the front and rear battery mount parts 160A, 160B is formed such that each gravity center of the battery pack 170A, 170B mounted to each battery mount part 160A, 160B is located on a plane including the driving axis of the hammer bit 119 and the center axis of the hand grip 109. Further, construction other than above is similar to that of the first embodiment.
According to the nineteenth embodiment, in two of the front and rear battery mount parts 160A, 160B, in a state that the battery packs 170A, 170B are mounted respectively, each gravity center of the battery pack 170A, 170B is located on the plane including the driving axis of the hammer bit 119 and the center axis of the hand grip 109. With such a construction, the batteries 170A, 170B can be balanced in weight with respect to the lateral direction of the hammer drill 100, and thereby operability of the hammer drill 100 is prevented from being damaged.
Further, according to the nineteenth embodiment, the battery pack 170A, 170B is mounted to the battery mount part 160A, 160B by sliding the mount guide 173 of the battery pack 170A, 170B along the guide rail 161 of the battery mount part 160A, 160B. Accordingly, the battery pack 170A, 170B can be easily mounted.
Further, according to the nineteenth embodiment, as shown in FIG. 33, an elastomer 104 formed as an elastic member for cushioning is installed on side outer surfaces of the lower connection part 103 b of the motor housing 103 is provided so as to extend in the front-rear direction. When the hammer drill 100 is placed on the ground by in a sideward posture in which its side surface is contacted with the ground, the tip end of the elastomer 104 contacts with the ground. With such a construction, end surfaces in the longitudinal direction of the battery packs 170A, 170B are avoided contacting directly with the ground. Accordingly, the battery packs 170A, 170B are protected by being damaged due to contact with the ground.

Twentieth Embodiment

Next, a twentieth embodiment of the present invention is explained with reference to FIG. 34 to FIG. 36. As shown in FIG. 34 to FIG. 36, according to the twentieth embodiment, in a construction in which two of the front and rear battery packs 170A, 170B are mounted by inserting from the side of the hammer drill 100 (in a direction crossing both of the longitudinal direction of the hammer bit 119 and an extending direction of the hand grip 109), those inserting directions are set to be opposite to each other. Constructions other than that described above are similar to those in the hammer drill 100 according to the nineteenth embodiment.
In the twentieth embodiment, with respect to components of two of the front and rear battery mount parts 160A, 160B, the arrangement and direction of the engagement part 163 and the terminal 165 of the front battery mount part 160A are formed opposite to those of the rear battery mount part 160B. With such a construction, as shown by arrows F in FIG. 35, one (front) battery pack 170A is mounted to the battery mount parts by moving the battery pack 170A from the right side to the left side of the hammer drill 100, and another (rear) battery pack 170B is mounted to the battery mount part by moving the battery pack 170B from the left side to the right side of the hammer drill 100.
According to the twentieth embodiment, two (even number) of the battery packs 170A, 170B are moved in respective directions against the hammer drill 100 and mounted. With such a construction, the combined gravity center of the battery packs 170A, 170B is located on a plane including the driving axis of the hammer bit 119 and the center axis of the hand grip 109. Therefore, it is not necessary to set the battery mount parts 160A, 160B in order to place the combined gravity center of the battery packs 170A, 170B on the plane including the driving axis of the hammer bit 119 and the center axis of the hand grip 109. Further, apart from the above, similar advantage as the first embodiment is obtained.

Twenty-First Embodiment

Next, a twenty-first embodiment of the present invention is explained with reference to FIG. 37 and FIG. 38. In the twenty-first embodiment, one battery mount part 160A is provided on the lower surface of the lower connection part 103 b of the motor housing 103. Further, one battery pack 170A is mounted to the battery mount part 160A by moving the battery pack 170A from the side of the hammer drill 100 (in a cross direction crossing both of the longitudinal direction of the hammer bit 119 and an extending direction of the hand grip 109).
According to the twenty-first embodiment, since an arrangement space for the battery pack 170A is reduced, a lower part of the electric motor 110 can be shifted rearward. Therefore, as shown in FIG. 37, the rotational shaft of the electric motor 110 can be arranged so as to be perpendicular to the driving axis and thereby the motor housing 103 is formed compact and to downsize the hammer drill 110 is possible. Further, apart from the above, similar advantage as the first embodiment is obtained.

Twenty-Second Embodiment

Next, a twenty-second embodiment of the present invention is explained with reference to FIG. 39. As shown in FIG. 39, according to the twenty-second embodiment, a vertical wall 103 which extends downwardly is provided at the center region of the lower surface of the lower connection part 103 b of the motor housing 103. The vertical wall 103 c is arranged between the front battery mount part 160A and the rear battery mount part 160B. The lower surface of the vertical wall 103 c is formed flush with the lower surface of the hammer drill 100 (the lower surface of the motor housing 103). Further, constructions other than that described above are similar to those in the hammer drill 100 according to the nineteenth embodiment.
According to the twenty-second embodiment, when the hammer drill 100 is placed on the ground, the vertical wall 103 c is utilized as a stand (pedestal) together with the lower surface of the motor housing 103. Thus, the hammer drill 100 is stably placed. Further, apart from the above, similar advantage as the first embodiment is obtained. Further, in the twenty-second embodiment, the inserting directions of the battery packs 170A, 170B to the battery mount parts 160A, 160B may be defined as the same directions to each other similar to the nineteenth embodiment or defined as the opposite directions to each other similar to the twentieth embodiment.

Twenty-Third Embodiment

Next, a twenty-second embodiment is explained with reference to FIG. 40. According to the twenty-second embodiment, in the fourth form of the hammer drill 100, an arrangement of the battery mount parts 160A, 160B is different from the hammer drill 100 according to the fifth embodiment. Constructions other than the battery mount parts 160A, 160B are similar to those in the hammer drill 100 according to the fifth embodiment, and therefore the same reference numerals are assigned and explanations thereof are omitted.
In the twenty-third embodiment, as shown in FIG. 40, the battery mount parts 160A, 160B are provided on an upper surface (upper side in FIG. 40) of the main body 101 in a direction in which the hand grip 109 is extended. The battery pack 170A is mounted to the battery mount part 160A by sliding against the battery mount part 160A in a direction of an arrow 23A. On the other hand, the battery pack 170B is mounted to the battery mount part 160B by sliding against the battery mount part 160B in a direction of an arrow 23B. The directions of the arrows 23A and 23B are parallel to a driving axis extending direction in which the driving axis of the hammer bit 119 is extended.
According to the twenty-third embodiment, with respect to the direction in which the hand grip 109 is extended, the battery mount parts 160A, 160B are arranged upward of a region of the main body 101, to which the hand grip 109 is connected. Accordingly, a free space on the upper side of the main body 101 is effectively utilized.

Twenty-Fourth Embodiment

Next, a twenty-fourth embodiment is explained with reference to FIG. 41. According to the twenty-fourth embodiment, in the second form of the hammer drill 100, an arrangement of the battery mount part 160B is different from the hammer drill 100 according to the fifteenth embodiment. Constructions other than the battery mount part 160B are similar to those in the hammer drill 100 according to the fifteenth embodiment, and therefore the same reference numerals are assigned and explanations thereof are omitted.
As shown in FIG. 41, in the twenty-fourth embodiment, with respect to a vertical direction in FIG. 41 in which the hand grip 109 is extended, the battery mount part 170A is arranged at a lower side of the main body 101 (lower side in FIG. 41) and the battery mount part 170B is arranged at an upper side of the main body 101 (upper side in FIG. 41). Specifically, the battery mount part 160A is arranged on the lower end part of the hand grip 109 and the battery mount part 160B is arranged on the upper end part of the hand grip 109. The battery pack 170A is mounted to the battery mount part 160A by sliding against the battery mount part 160A in a direction of an arrow 24A. On the other hand, the battery pack 170B is mounted to the battery mount part 160B by sliding against the battery mount part 160B in a direction of an arrow 24B. Further, the directions of the arrows 24A and 24B are parallel to a driving axis extending direction in which the driving axis of the hammer bit 119 is extended, and the direction of the arrow 24A is a direction from front to rear of the hammer drill 100, and the direction of arrow 24B is a direction from rear to front of the hammer drill 100. Further, in the twenty-fourth embodiment, attaching directions of the battery packs 170A, 170B are different directions to each other, however attaching directions of the battery packs 170A, 170B may be matched with each other. On the other hand, each battery mount parts 160A, 160B may be formed such that the battery pack 170A is slid in the direction of the arrow 24B and mounted to the battery mount part 160A, and the battery pack 170B is slid in the direction of the arrow 24A and mounted to the battery mount part 160B.

Twenty-Fifth Embodiment

Next, a twenty-fifth embodiment is explained with reference to FIG. 42 and FIG. 43. According to the twenty-fifth embodiment, in the first form of the hammer drill 100, an arrangement of the battery mount parts 160A, 160B is different from the hammer drill 100 according to the first embodiment, and the hammer drill 100 according to the twenty-fifth embodiment further comprises an additional device mounting part 190. Constructions other than the arrangement of the battery mount parts 160A, 160B are similar to those in the hammer drill 100 according to the first embodiment, and therefore the same reference numerals are assigned and explanations thereof are omitted.
In the hammer drill 100 according to the twenty-fifth embodiment, the battery mount parts 160A, 160B are respectively arranged on both sides of the main body 101 in a direction (lateral direction in FIG. 43) crossing both of the longitudinal direction of the hammer bit 119 (lateral direction in FIG. 42) and a direction in which the hand grip 109 is extended (vertical direction in FIG. 42). The battery packs 170A, 170B are respectively mounted to the battery mount parts 160A, 160B by sliding against the battery mount parts 160A, 160B in a direction of an arrow 25A shown in FIG. 42. Further, the direction of the arrow 25A is parallel to the driving axis extending direction in which the driving axis of the hammer bit 119 is extended.
Further, in the twenty-fifth embodiment, the additional device mounting part 190 is formed at a lower part of the hand grip 109 and rearward of the motor housing 103. The additional device mounting part 190 comprises an engaging part (not shown). For example, large-sized battery pack larger than the battery pack 170A, 170B, a dust collecting device and so on are mounted to the additional device mounting part 190. The large-sized battery pack or the dust collecting device is engaged with the engaging part of the additional device mounting part 190 and held by the additional device mounting part 190.

Twenty-Sixth Embodiment

Next, a twenty-sixth embodiment is explained with reference to FIG. 44. According to the twenty-sixth embodiment, in the second form of the hammer drill 100, to provide only one battery mount part is different from the hammer drill 100 according to the fifteenth embodiment. Constructions other than the battery mount part are similar to those in the hammer drill 100 according to the fifteenth embodiment, and therefore the same reference numerals are assigned and explanations thereof are omitted.
In the hammer drill 100 according to the fifteenth embodiment, the battery mount part 160A is arranged on the lower part of the main body 101 (lower part of the motor housing 103) and frontward of the hand grip 109 (support member 107). The battery pack 170A with voltage required for driving the electric motor 110 is mounted to the battery mount part 160A. The battery pack 170A is mounted to the battery mount part 160A by sliding against the battery mount part 160A in a direction of an arrow 26A. Further, the direction of the arrow 26A is parallel to the driving axis extending direction in which the driving axis of the hammer bit 119 is extended.
According to the twenty-sixth embodiment, since the battery mount part 160A is provided on the motor housing 103, the gravity center of the hammer drill 100 can be closer to the driving axis of the hammer bit 119. Further, a free space on the main body 101 of the hammer drill 100 and frontward of the hand grip 109 is effectively utilized.
Further, the arrangement of two battery mount parts 160A, 160B and the moving direction of the battery packs 170A, 170B while attaching may be utilized from combination of each aspect described in the first through twenty-sixth embodiments as needed.
Furthermore, in the first through twenty-sixth embodiments described above, the mount part 160 is fixed on the main body 101 or the handgrip 109, however it is not limited to this. For example, the mount part 160 may be attachable to or detachable from the main body 101 or the hand grip 109. Further, the battery pack may be attached via a predetermined adapter to a region from which the mount part 160 is detached. Further, in the first through twenty-sixth embodiments, two battery mount parts 160A, 160B are provided, however more than three battery mount parts may be provided.
Further, in the first through twenty-sixth embodiments described above, as an example of the power tool, the hammer drill 100 in which the hammer bit 119 performs the hammering operation and the rotational operation is utilized for explanation, however it is not limited to this. For example, the present invention is applicable to a hammer which only performs the hammering operation as the power tool. Apart from that, as the power tool, the present invention is applicable to an electric driver, an electric wrench, an electric grinder, an electric reciprocating saw or an electric jigsaw.
Having regard to an aspect of the present invention, following features are provided as the power tool according to the present invention. Further, each feature may be utilized independently or in conjunction with other feature(s) or claimed invention(s).

(Feature 1)

A power tool which drives a detachably attached tool bit in a driving axis of the tool bit, comprising:
a motor which drives the motor,
a tool body which houses the motor,
a handle which is connected to the tool body, and
a plurality of battery mount parts to which a battery for providing electric current to the motor is detachably mounted,
wherein the power tool is configured to be able to provide electric current from a plurality of the batteries mounted to said plurality of the battery mount parts to the motor,
the handle is provided on a predetermined plane which includes the driving axis such that the handle extends in a handle extending direction crossing a driving axis extending direction in which the driving axis extends,
each battery mount part comprises a battery engaging part with which the battery is engageable and holds the battery by engaging the battery with the battery engaging part, and
the battery is slid against the battery engaging part in a normal direction of the predetermined plane and mounted to the battery mount part.

(Feature 2)

The battery engaging part comprises a guide rail on which the battery is engaged and slid.

(Feature 3)

The guide rail of the battery engaging part is provided so as to extend in a direction crossing both of the driving axis extending direction and the handle extending direction.

(Feature 4)

The tool body has a tool body lower surface which is formed flush with the lower surface of the battery when the battery is mounted to the battery mount part.

(Feature 5)

A plurality of the battery mount parts are electrically connected to each other such that the mounted batteries are electrically connected in series.

(Feature 6)

A plurality of the battery mount parts are electrically connected to each other such that the mounted batteries are electrically connected in parallel.

(Feature 7)

A plurality of the battery mount parts are electrically connected to each other such that a first connecting mode in which the mounted batteries are electrically connected in series and a second connecting mode in which the mounted batteries are electrically connected in parallel are switchable.

(Feature 8)

A power tool which drives a detachably attached tool bit in a driving axis of the tool bit, comprising:
a motor which drives the tool bit,
a tool body which houses the motor, and
a battery mount part to which a battery for providing electric current is detachably mounted,
wherein the power tool comprises two battery mount parts and can provide electric current from the battery mounted to the battery mount part to the motor,
two battery mount parts are aligned on a straight line extending in a predetermined direction,
the battery mount part comprises a battery engaging part and holds the battery by engaging the battery with the battery engaging part,
the battery is mounted to one battery mount part among said two battery mount parts by sliding the battery on the battery engaging part in a direction in which the battery approaches another battery mount part, and
the battery is mounted to another battery mount part among said two battery mount parts by sliding the battery on the battery engaging part in a direction in which the battery approaches the one battery mount part.

(Feature 9)

The power tool according to feature 8, wherein the predetermined direction is defined as a direction parallel to the driving axis.

(Feature 10)

The power tool according to feature 8 or 9, further comprising a handle which is connected to the tool body,
wherein the handle is provided such that it extends in a handle extending direction crossing the driving axis, of which at least one end side in the handle extending direction is connected to the tool body, and
two battery mount parts are arranged at another end side of the handle in the handle extending direction.

(Feature 11)

The power tool according to feature 8 or 9, further comprising a handle which is connected to the tool body,
wherein the handle is provided such that it extends in a handle extending direction crossing the driving axis, of which at least one end side in the handle extending direction is connected to the tool body, and
two battery mount parts are arranged on the tool body at said one end side of the handle in the handle extending direction.

(Feature 12)

The power tool according to any one of features 8 to 11, wherein the motor is arranged such that a rotational axis of the motor is intersected with the driving axis.

(Feature 13)

The power tool according to any one of features 8 to 11, wherein the motor is arranged such that a rotational axis of the motor is parallel to the driving axis.

(Feature 14)

The power tool according to feature 10 or 11, wherein the motor is arranged such that a rotational axis of the motor is parallel to the driving axis,
the handle includes a grip portion which is held by a user, and
the grip portion is arranged on the driving axis line.

(Feature 15)

The power tool according to feature 10 or 11, wherein the motor is arranged such that a rotational axis of the motor is parallel to the driving axis,
the handle includes a grip portion of which one end side is connected to the tool body and a reinforcing member which further connects another end side of the grip portion and the tool body.

(Feature 16)

The power tool according to any one of features 8 to 15, wherein two batteries are mounted to said two battery mount parts respectively such that a front surface of one battery with respect to a sliding direction of said one battery against the battery engaging part when said one battery is mounted to one battery mount part and a front surface of another battery with respect to a sliding direction of said another battery against the battery engaging part when said another battery is mounted to another battery mount part face each other.

(Feature 17)

A power tool which drives a detachably attached tool bit in a driving axis of the tool bit, comprising:
a motor which drives the tool bit,
a tool body which houses the motor,
a handle which is connected to the tool body, and
a battery mount part to which a battery for providing electric current is detachably mounted,
wherein the power tool comprises two battery mount parts and can provide electric current from the battery mounted to the battery mount part to the motor, and
said two battery mount parts are arranged at mutually separated two points between which the tool body and/or the handle are/is arranged.

(Feature 18)

The power tool according to feature 17, wherein the handle is arranged so as to extend in a handle extending direction crossing a driving axis extending direction in which the driving axis is extended, of which at least one end side in the handle extending direction is connected to the tool body, and
one battery mount part among said two battery mount parts is arranged at another end side of the handle in the handle extending direction.

(Feature 19)

The power tool according to feature 18, wherein another battery mount part among said two battery mount parts is arranged on the tool body at one side of the tool body in the handle extending direction.

(Feature 20)

The power tool according to feature 19, wherein said another battery mount part among said two battery mount parts is arranged on the tool body at the same side with respect to the driving axis as said one battery mount part.

(Feature 21)

The power tool according to any one of features 18 to 20, wherein the motor is arranged such that a rotational axis of the motor is parallel to the driving axis.

(Feature 22)

The power tool according to feature 21, wherein the handle comprises a grip portion which is held by a user, and
the grip portion is arranged on a driving axis line.

(Feature 23)

The power tool according to feature 21, wherein the handle comprises a grip portion in which its one end side is connected to the tool body and a reinforcing member which connects another end side of the grip portion and the tool body, and
another battery mount part among said two battery mount parts is arranged on the reinforcing member.

(Feature 24)

The power tool according to feature 18, wherein the motor is arranged such that a rotational axis of the motor is intersected with the driving axis, and
another battery mount part among said two battery mount parts is arranged at a side opposite to said one battery mount part with respect to the motor in the driving axis extending direction.

(Feature 25)

The power tool according to feature 17, wherein the handle is arranged so as to extend in a handle extending direction crossing a driving axis extending direction in which the driving axis is extended, and
said two battery mount parts are arranged at both sides of the tool body in a cross direction crossing both of the driving axis extending direction and the handle extending direction.

(Feature 26)

The power tool according to any one of features 17 to 21, wherein said two battery mount parts are arranged so as to be mutually separated with respect to an extending direction in which the driving axis is extended.

(Feature 27)

The power tool according to any one of features 17 to 21, wherein said two battery mount parts are arranged so as to be mutually separated with respect to a direction crossing an extending direction in which the driving axis is extended.

(Feature 28)

The power tool according to any one of features 17 to 27, wherein the battery mount part comprises a battery engaging part and holds the battery by engaging the battery with the battery engaging part,
the battery engaging part is formed so as to extend in a direction parallel to a virtual plane including the driving axis and a handle extending axis of the handle which extends in the handle extending direction, and
the battery is mounted to the battery mount part by sliding against the battery engaging part in a direction parallel to the virtual plane.

(Feature 29)

The power tool according to any one of features 17 to 28, wherein the battery to be mounted to the battery mount parts is formed as an elongate-shape which extends in a predetermined longitudinal direction, and
said two battery mount parts are formed such that a longitudinal direction of the battery mounted to one battery mount part among said two battery mount parts and a longitudinal direction of the battery mounted to another battery mount part are parallel to each other.

(Feature 30)

The power tool according to any one of features 17 to 28, wherein the battery to be mounted to the battery mount parts is formed as an elongate-shape which extends in a predetermined longitudinal direction, and
said two battery mount parts are formed such that a longitudinal direction of the battery mounted to one battery mount part among said two battery mount parts and a longitudinal direction of the battery mounted to another battery mount part are intersected with each other.

(Feature 31)

A hammering tool which drives a tool bit at least linearly on a driving axis extending in a predetermined longitudinal direction, comprising:
a motor which drives the tool bit,
a tool body which houses the motor,
a handle which is connected to the tool body, and
a battery mount part to which a battery for providing electric current to the motor is detachably attached,
wherein the hammering tool comprises a plurality of the battery mount parts,
the handle is provided such that it extends in a handle extending direction crossing the longitudinal direction, and
the battery mount part is fixed on the tool body and undetachable from the hammering tool.

(Feature 32)

The hammering tool according to feature 31, wherein the battery mount part comprises a battery engaging part with which the battery is engageable and the battery mount part holds the battery by engaging the battery with the battery engaging part,
the battery is slid against the battery engaging part and mounted to the battery mount part.

(Feature 33)

The hammering tool according to feature 32, wherein a plurality of the battery engaging parts are provided such that the batteries are attached by moving each battery in the same direction.

(Feature 34)

The hammering tool according to feature 32 or 33, wherein a plurality of the battery mount parts are arranged to be aligned in the longitudinal direction, and each battery is attached by moving in a cross direction crossing both of the longitudinal direction and the handle extending direction.

(Feature 35)

The hammering tool according to feature 32 or 33, wherein a plurality of the battery mount parts are arranged to be aligned in a cross direction crossing both of the longitudinal direction and the handle extending direction, and each battery is attached by moving in a direction parallel to the longitudinal direction.

(Feature 36)

The hammering tool according to feature 32, wherein two battery mount parts among the plurality of the battery mount parts are aligned on a line which extends in a predetermined direction,
the battery is attached to one battery mount part among said two battery mount parts by sliding against the battery engaging part in a direction close to another battery mount part, and
the battery is attached to another battery mount part among said two battery mount parts by sliding against the battery engaging part in a direction close to one battery mount part.

(Feature 37)

The hammering tool according to any one of features 32 to 36, wherein the battery is attached to the battery mount part by sliding against the battery engaging part in a cross direction crossing both of the longitudinal direction and the handle extending direction.

(Feature 38)

The hammering tool according to any one of features 31 to 37, wherein two battery mount parts among the plurality of the battery mount parts are arranged at mutually separated two points between which the tool body and/or the handle are/is arranged.

(Feature 39)

The hammering tool according to any one of features 31 to 38, wherein the motor is arranged such that a rotational axis of the motor is parallel to the driving axis.

(Feature 40)

The hammering tool according to feature 39, wherein the handle comprises a grip portion which is held by a user, and the grip portion is arranged on a driving axis line.

(Feature 41)

The hammering tool according to feature 39 or 40, wherein the handle comprises a grip portion in which its one end side is connected to the tool body and a reinforcing member which connects another end side of the grip portion and the tool body, and
at least one battery mount part among a plurality of the battery mount parts is arranged on the reinforcing member.

(Feature 42)

The hammering tool according to any one of features 31 to 37, wherein the motor is arranged such that a rotational axis of the motor is intersected with the driving axis.

(Feature 43)

The hammering tool according to any one of features 38 to 42, wherein two battery mount parts among a plurality of the battery mount parts are arranged respectively at both side of the tool body in a cross direction crossing both of the longitudinal direction and the handle extending direction.

(Feature 44)

A hammering tool which drives a tool bit at least linearly on a driving axis extending in a predetermined longitudinal direction, comprising:
a motor which drives the tool bit,
a tool body which houses the motor,
a handle which is connected to the tool body, and
a mount part to which a battery for providing electric current to the motor is detachably mounted,
wherein the handle is provided such that it extends in a handle extending direction crossing the longitudinal direction,
the mount part comprises a battery engaging part with which the battery is engageable and the mount part holds the battery by engaging the battery with the battery engaging part, and
the battery is slid in a cross direction crossing both of the longitudinal direction and the handle extending direction with respect to the battery engaging part and the battery is mounted to the mount part.

(Feature 45)

The hammering tool according to feature 44, wherein the mount part is provided such that the gravity center of the battery mounted to the mount part is located on a plane including the driving axis and a handle central axis which extends in the handle extending direction.

(Feature 46)

The hammering tool according to feature 44 or 45, wherein the mount part comprises a plurality of battery mount parts to which a plurality of batteries is detachably mounted respectively, and
said plurality of battery mount parts is arranged so as to be aligned in the longitudinal direction.

(Feature 47)

The hammering tool according to feature 46, further comprising a partition wall which is arranged between at least two battery mount parts among said plurality of battery mount parts and is extended in the handle extending direction,
wherein a vertical direction is defined by the handle extending direction, and
a lower surface of the partition wall is formed flush with a lower surface of the tool body.

(Feature 48)

The hammering tool according to feature 46 or 47, wherein the mount part comprises an even number of the battery mount parts to which each of an even number of the batteries is detachably mounted,
the battery is mounted to a half number of the battery mount part among said even number of the battery mount parts by sliding the battery against the battery engaging part in one direction, and
the battery is mounted to the rest of a half of the battery mount part among said even number of the battery mount parts by sliding the battery against the battery engaging part in a direction opposite to said one direction.

(Feature 49)

The hammering tool according any one of features 46 to 48, wherein the mount part comprises an even number of the battery mount parts to which each of an even number of the batteries is detachably mounted, and
each battery mount parts positioned next to each other are formed such that the battery is mounted to the battery mount part by moving in an opposite direction which is opposite to a direction in which the battery is moved when it is mounted to another battery mount part next to said battery mount part.

(Feature 50)

The hammering tool according to any one of features 46 to 49, wherein said plurality of battery mount parts is formed such that the combined gravity center of a plurality of the batteries mounted to said plurality of battery mount parts is located on a plane including the driving axis and a handle central axis which extends in the handle extending direction.

(Feature 51)

The hammering tool according to any one of features 44 to 50, wherein the motor is arranged such that a rotational axis of the motor is intersected with the driving axis.

Correspondence Relationships Between the Constituent Elements of the Present Embodiments and the Constituent Elements of the Present Invention

The correspondence relationships between elements of the embodiments and elements of the present invention are as follows. Further, the embodiments describe merely examples of configurations for carrying out the present invention, and the present invention is not limited to the configurations of the embodiments.
The main body 101 is one example of a configuration that corresponds to “a tool body” of the present invention.
The hammer bit 119 is one example of a configuration that corresponds to “a tool bit” of the present invention. The electric motor 110 is one example of a configuration that corresponds to “a motor” of the present invention.
Two battery mount parts 160A, 160B is one example of a configuration that corresponds to “a plurality of battery mount parts” of the present invention.
The battery mount part 160A is one example of a configuration that corresponds to “a battery mount part” of the present invention.
The battery mount part 160B is one example of a configuration that corresponds to “a battery mount part” of the present invention.
The battery pack 170A is one example of a configuration that corresponds to “a battery” of the present invention.
The battery pack 170B is one example of a configuration that corresponds to “a battery” of the present invention.
The guide rail 161 is one example of a configuration that corresponds to “a battery engaging part” of the present invention.
The engagement part 163 is one example of a configuration that corresponds to “a battery engaging part” of the present invention.
The rubber pin 167 is one example of a configuration that corresponds to “an elastic member” of the present invention.
The support member 107 is one example of a configuration that corresponds to “a reinforcing member” of the present invention.

DESCRIPTION OF NUMERALS

100 hammer drill
101 main body
103 motor housing
103 a upper connection part
103 b lower connection part
103 c vertical wall
104 elastomer
105 gear housing
107 support member
109 hand grip
109A grip portion
109 a trigger
110 electric motor
111 motor shaft
119 hammer bit
120 motion converting mechanism
121 intermediate shaft
123 rotation member
125 swing member
127 cylindrical piston
127 a air chamber
129 cylinder
130 controller
140 hammering mechanism
143 striker
145 impact bolt
150 power transmitting mechanism
151 first gear
153 second gear
159 tool holder
160 mount part
160A battery mount part
160B battery mount part
161 guide rail
163 engagement part
165 terminal
167 rubber pin
170A battery pack
170B battery pack
171 battery case
173 mount guide
175 hook for locking
177 press button for unlocking
179 terminal
180 cover member
181 support shaft
183 engagement recess
185 engagement protrusion
190 additional device mounting part

Claims

1. A power tool which drives a detachably attached tool bit in a driving axis of the tool bit, comprising:

a motor which drives the tool bit,

a tool body which houses the motor,

a handle which is connected to the tool body, and

a battery mount part to which a battery for providing electric current is detachably mounted,

wherein the power tool comprises a plurality of the battery mount parts and can provide electric current from the battery mounted to the battery mount part to the motor,

the handle is provided such that it extends in a handle extending direction crossing a driving axis extending direction in which the driving axis extends,

the battery mount part comprises a battery engaging part with which the battery is engageable and the battery mount part holds the battery by engaging the battery with the battery engaging part, and

the battery is slid in a cross direction crossing both of the driving axis extending direction and the handle extending direction with respect to the battery engaging part and the battery is mounted to the battery mount part.

2. The power tool according to claim 1, wherein a plurality of the battery mount parts are aligned in the driving axis extending direction.

3. The power tool according to claim 1, wherein the battery engaging parts are provided such that the batteries are slid from the same side of the tool body with respect to the cross direction and engaged with the battery engaging parts.

4. The power tool according to claim 1, wherein a plurality of the battery mount parts is arranged at a side opposite to the tool bit with respect to the motor in the driving axis extending direction.

5. The power tool according to claim 1, wherein, when the battery is mounted to the battery mount part, a lower surface of the battery is formed flush with a lower surface of the tool body.

6. The power tool according to claim 1, wherein the battery mount part is formed such that a length of the battery mounted to the battery mount part in the driving axis extending direction is shorter than a length of the battery in the cross direction.

7. The power tool according to claim 1, wherein the batter mount part comprises an elastic member which protrudes toward the battery and contacts with the battery when the battery mounted to the battery mount part.

8. The power tool according to claim 1, wherein the handle is provided such that at least its one end side in the handle extending direction is connected to the tool body, and

a plurality of the battery mount parts is arranged on another end side of the handle in the handle extending direction.

9. The power tool according to claim 8, wherein the handle comprises a grip portion which is held by a user, and the grip portion is arranged on a driving axis line.

10. The power tool according to claim 9, wherein a plurality of the battery mount parts is provided on the tool body at one side with respect to the handle extending direction.

11. The power tool according to claim 8, wherein the handle comprises a grip portion in which its one end side is connected to the tool body and a reinforcing member which connects another end side of the grip portion and the tool body.

12. The power tool according to claim 11, wherein a plurality of the battery mount parts is arranged on the reinforcing member.

13. The power tool according to claim 1, wherein the motor is arranged such that a rotational axis of the motor is intersected with the driving axis.

14. The power tool according to claim 1, wherein the motor is arranged such that a rotational axis of the motor is paralleled to the driving axis.

15. The power tool according to claim 1, wherein said plurality of battery mount parts is formed such that the combined gravity center of a plurality of the batteries mounted to said plurality of battery mount parts is located on a plane including the driving axis and a handle central axis which extends in the handle extending direction.

16. A power tool which drives a tool bit at least linearly on a driving axis extending in a predetermined longitudinal direction, comprising:

a motor which drives the tool bit,

a tool body which houses the motor,

a handle which is connected to the tool body, and

a battery mount part to which a battery for providing electric current to the motor is detachably attached,

wherein the power tool comprises a plurality of the battery mount parts,

the handle is provided such that it extends in a handle extending direction crossing the longitudinal direction, and

the battery mount part is fixed on the tool body and undetachable from the power tool.

17. The power tool according to claim 16, wherein the battery mount part comprises a battery engaging part with which the battery is engageable and the battery mount part holds the battery by engaging the battery with the battery engaging part,

the battery is slid against the battery engaging part and mounted to the battery mount part.

18. The power tool according to claim 16, wherein a plurality of the battery mount parts are arranged to be aligned in a cross direction crossing both of the longitudinal direction and the handle extending direction, and each battery is attached by moving in a direction parallel to the longitudinal direction.