Patent Publication Number: US-9844865-B2

Title: Driver tool

Description:
CROSS-REFERENCE 
     This application is the U.S. National Stage of International Application No. PCT/JP2013/060375 filed on Apr. 4, 2013, which claims priority to Japanese patent application no. 2012-088842 filed on Apr. 9, 2012. 
     TECHNICAL FIELD 
     The present invention relates to a driving tool that performs a driving operation of a struck material. 
     BACKGROUND ART 
     Japanese Laid-open Patent Publication No. 2011-25363 discloses an electric/pneumatic driving tool having a battery-powered electric motor and a compression device which is driven by the electric motor. In this driving tool, compressed air generated by the compression device is supplied into a cylinder, and a driving mechanism is linearly moved by this compressed air, so that a nail serving as a struck material is driven. 
     SUMMARY OF THE INVENTION 
     Incidentally, in case a nail driving operation will be performed, it is important to realize a size reduction of the driving tool from the viewpoint of improving operability. In the driving tool described in Japanese Laid-open Patent Publication No. 2011-25363, a compression cylinder for use in generating compressed air is disposed close and parallel to the driving cylinder, and a handle is connected to intersect with the compression cylinder. 
     In a structure in which the compression cylinder and the driving cylinder are disposed in parallel with each other, however, if a piston is designed to have a stroke required to generate compressed air, a rear region (compression chamber) of the compression cylinder protrudes rearward of a rear end of the driving cylinder, wherein the nail driving direction of the driving mechanism is defined as a forward direction (front) of the driving tool and its opposite is defined as a rearward direction (rear) of the driving tool. Therefore, it is not effective in shortening of the driving tool in the front-rear direction. 
     The present invention has been made in view of the problem above and it is an object of the present invention to provide a driving tool that enables size reduction. 
     The above-described problem can be solved by claim  1 . A preferred aspect of a driving tool of the present invention includes a first cylinder, a first piston that is disposed so as to be slidable within the first cylinder and is configured to generate compressed air in the first cylinder, a motor that drives the first piston, a second cylinder, a second piston that is disposed so as to be slidable within the second cylinder and has a sliding part and an elongate driving part connected to the sliding part, a handle, and a magazine that is configured to feed the struck material onto an axis of movement of the driving part. The compressed air in the first cylinder is supplied into the second cylinder and the second piston is linearly moved toward a front end of the second cylinder by the compressed air, so that the driving part drives the struck material. Further, the “driving tool” in the present invention corresponds in a representative manner to nailers or tackers. In addition, the “struck material” suitably includes straight rod-like items with a sharp point or to staples having a U-shape. The manner of “feeding the struck material onto the axis of movement of the driving part” by the magazine suitably includes a manner of feeding the material onto the axis of movement of the driving part from a direction perpendicular to the axis of movement, and to a manner of feeding the material onto the axis of movement from a direction oblique to the axis of movement. 
     Further, the first cylinder is arranged to intersect with the second cylinder and extend alongside the magazine. The first piston is configured to slide in a direction alongside the magazine. The handle is disposed on the opposite side of the first cylinder from the magazine with reference to the direction that the axis of movement of the driving part extends. Further, the magazine in the present invention is configured as an elongate member extending in a prescribed direction so as to store a plurality of materials side by side in the prescribed direction. The manner of arranging the handle suitably includes a manner of arranging it in parallel to the magazine and a manner of arranging it obliquely to the magazine. 
     According to the present invention, the first cylinder is arranged to intersect with the second cylinder and extend alongside the magazine, and the first piston slides in a direction alongside the magazine. Therefore, in case the direction in which the second piston drives the struck material is defined as a forward direction and its opposite direction is defined as a rearward direction, the first cylinder is precluded from protruding in the rearward direction of the driving tool. As a result, the overall length of the driving tool can be shortened, so that the driving tool is reduced in size. 
     According to a further aspect of the driving tool of the present invention, the magazine and the first cylinder are disposed at a front end region of the second cylinder. Further, the handle is disposed at a rear end region of the second cylinder on a side opposite to the front end region of the second cylinder. 
     In known driving tools, the compression cylinder and the driving cylinder are disposed in parallel to each other and the handle is connected to the compression cylinder. Therefore, the handle is located at a distant position from the axis of movement of the driving part disposed within the driving cylinder. According to this embodiment, however, because the handle is disposed at the rear end region of the second cylinder, the handle can be arranged to be located closer to the axis of movement of the driving part. With this arrangement, it is possible to suppress the occurrence of moments around the handle held by the user, which moments are caused by recoil during the driving operation of the struck material. Further, when performing the driving operation of the struck material, a pressing force exerted onto the handle can be efficiently applied to the workpiece. 
     According to a further aspect of the driving tool of the present invention, the magazine and the first cylinder are disposed adjacent to each other. According to this aspect, by disposing the first cylinder adjacent to the magazine, a further size reduction of the driving tool can be realized. 
     According to a further aspect of the present invention, the driving tool has a compressed air supply passage that provides communication between the first cylinder and the second cylinder, and a valve member that is disposed in the compressed air supply passage and serves to provide and cut off communication between the first cylinder and the second cylinder. The valve member is disposed in a connecting region, which is connected to the second cylinder, of the compressed air supply passage. 
     According to this aspect, by disposing the valve member in the connecting region, which is connected to the second cylinder, of the compressed air supply passage, a majority of the compressed air supply passage normally is in communication with the first cylinder. Specifically, the compressed air supply passage can be used as part of the compression chamber. Therefore, the compressed air is prevented from expanding while being supplied into the second cylinder, so that energy losses are reduced. 
     According to a further aspect of the driving tool of the present invention, the compressed air supply passage is provided alongside a longitudinal axis of the second cylinder. The manner of forming the “compressed air supply passage” suitably includes a manner of integrally forming it as an inner passage inside a wall of the second cylinder and a manner of forming it as a separate member from the second cylinder. In case it is formed as a separate member, the compressed air supply passage is preferably configured as a tubular member. 
     According to this aspect, by providing the compressed air supply passage alongside the longitudinal axis of the second cylinder, other components for the driving tool can be rationally arranged. Specifically, other components are arranged without interfering with the compressed air supply passage. 
     According to a further aspect of the driving tool of the present invention, the magazine and the first cylinder are disposed in parallel to each other. Further, as for the manner of being “parallel”, it is not necessary to be strictly parallel, but it may be substantially parallel. 
     According to this aspect, by arranging the magazine and the first cylinder in parallel with each other, it is possible to eliminate waste with regard to installation space. 
     According to a further aspect of the driving tool of the present invention, a rotation axis of the motor is arranged in parallel to the longitudinal axis of the second cylinder. Further, as for the manner of being “parallel”, it is not necessary to be strictly parallel, and it may be substantially parallel. 
     According to a further aspect of the present invention, the driving tool has an operating member that is manually operated by a user in order to control the motor. The first cylinder, the second cylinder, the handle and the motor are arranged to form a hollow space surrounded by the four parts. The operating member is arranged to project into the hollow space. The operating member suitably includes a trigger and a switch, which are operated by the user. Further, the operating member is preferably mounted on the handle, and more preferably is disposed in a region of the handle that is adjacent to the second cylinder. 
     According to this aspect, by forming the hollow space surrounded by the first cylinder, the second cylinder, the handle and the motor, strength against external forces that act on the driving tool inwardly from outside of the hollow space is increased. Further, because the operating member is arranged to project into the hollow space, the operating member is protected from the external forces. In addition, in case the operating member is disposed in the region of the handle that is adjacent to the second cylinder, the operating member can be easily operated by the user holding the handle. 
     According to a further aspect of the driving tool of the present invention, the first cylinder, the second cylinder, the handle and the motor are arranged to form a quadrilateral having the four members as its respective sides. According to this aspect, strength against external forces acting on the driving tool is increased. 
     According to a further aspect of the driving tool of the present invention, one end of the handle is connected to the second cylinder. In addition, the handle is arranged to extend in a crossing direction that crosses a longitudinal direction of the second cylinder. The motor and a battery that supplies power to the motor are disposed on the other end of the handle in the crossing direction. 
     According to this aspect, by disposing the motor and the battery at the other end of the handle, the parts of the electrical system are rationally disposed adjacent to each other. Further, in case the weight ratio of the motor and the battery, which are disposed at the other end of the handle, to the second cylinder which is connected to the one end of the handle, is set to about one, the center of gravity of the driving tool is located substantially in the middle of the handle, so that operability of the driving tool is improved. 
     According to the present invention, an improved driving tool is provided that enables size reduction. 
     Other objects, features and advantages of this invention 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  is an external view showing the overall structure of a nailer. 
         FIG. 2  is a view as seen from arrow A in  FIG. 1 . 
         FIG. 3  is a sectional view showing the overall structure of the internal mechanisms of the nailer. 
         FIG. 4  is a sectional view taken along line B-B in  FIG. 3 . 
         FIG. 5  is a sectional view taken along line C-C in  FIG. 3 . 
         FIG. 6  is a sectional view taken along line D-D in  FIG. 2 . 
         FIG. 7  is a view showing a link mechanism for moving a valve. 
         FIG. 8  is a sectional view taken along line E-E in  FIG. 3  and showing a state in which the valve is located at a forward position to cut off communication between a compression chamber and a cylinder chamber. 
         FIG. 9  is a sectional view showing a nail driving state in which the valve is located at a rear position to provide communication between the compression chamber and the cylinder chamber, and a driving piston is moved forward. 
         FIG. 10  is a sectional view showing a state in which the communication between the compression chamber and the cylinder chamber is maintained and the driving piston is returned near to a rear initial position. 
         FIG. 11  is a perspective view showing a cylindrical cam. 
         FIG. 12  is a sectional view showing a modification to the valve. 
     
    
    
     DETAILED DESCRIPTION 
     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 improved driving tools and devices utilized therein. Representative examples of this 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. 
     An embodiment of the present invention will now be described with reference to  FIGS. 1 to 11 . This embodiment will be explained using an electric-pneumatic nailer as one example of a driving tool according to the present invention. As shown in  FIGS. 1 and 2 , a nailer  100  mainly includes a body housing  101  serving as a tool body that forms an outer shell of the nailer  100 , and a magazine  105  that stores nails (not shown) serving as a struck material to be driven into a workpiece. The body housing  101  is formed by joining together a pair of substantially symmetrical housings. The body housing  101  integrally has a handle  103  to be held by a user, a driving mechanism housing part  101 A for housing a nail driving mechanism  120  (see  FIG. 3 ), a compression device housing part  101 B for housing a compression device  130  (see  FIG. 3 ) and a motor housing part  101 C for housing an electric motor  111  (see  FIG. 7 ). 
     The handle  103 , the driving mechanism housing part  101 A, the compression device housing part  101 B and the motor housing part  101 C of the body housing  101  are arranged to form a generally quadrilateral shape having these four parts as its respective sides. Specifically, the handle  103  and the compression device housing part  101 B are arranged to form one pair of opposed sides, and the driving mechanism housing part  101 A and the motor housing part  101 C are arranged to form the other pair of opposed sides, so that the four parts form a quadrilateral shape such as a rectangle, square, trapezoid or parallelogram shape. Further, it is not necessary for all of the four parts to extend in a straight line; for example, the handle  103  may be formed to extend in a curved line. The handle  103  is an elongate member having a prescribed length; one end of the handle  103  in its direction of extension is connected to one (rear) end region of the driving mechanism housing part  101 A and the other end in its direction of extension is connected to one (rear) end region of the motor housing part  101 C. The compression device housing part  101 B is arranged to extend substantially in parallel to the handle  103 ; one end of the compression device housing part  101 B in its direction of extension is connected to the other (front) end region of the driving mechanism housing part  101 A and the other (front) end region in its direction of extension is connected to the other (front) end region of the motor housing part  101 C. Thus, the handle  103 , the driving mechanism housing part  101 A, the compression device housing part  101 B and the motor housing part  101 C define an approximately quadrilateral space S. The handle  103  is an example embodiment that corresponds to the “handle” according to the present invention. 
       FIG. 1  shows a nail driving direction (discharge direction) in which a nail is driven in the rightward direction in  FIG. 1  through a driver guide  141  disposed at a front end (right end as viewed in  FIG. 1 ) of the nailer  100 . The nail driving direction is a nail striking direction in which a driver  125  (see  FIG. 3 ) strikes the nail. Further, for the sake of convenience of explanation, the front end side of the nailer  100  (the right as viewed in  FIG. 1 ) is taken as the front or front side and its opposite side is taken as the rear or rear side. The side of a connection between the handle  103  and the driving mechanism housing part  101 A (upper side as viewed in  FIG. 1 ) is taken as the top or upper side and the side of a connection between the handle  103  and the motor housing part  101 C (lower side as viewed in  FIG. 1 ) is taken as the bottom or lower side. 
     As shown in  FIG. 3 , the nail driving mechanism  120  is housed in the driving mechanism housing part  101 A of the body housing  101 . The nail driving mechanism  120  mainly includes a driving cylinder  121  and a driving piston  123 . The driving cylinder  121  and the driving piston  123  are example embodiments that correspond to the “second cylinder” and the “second piston”, respectively, according to the present invention. 
     The driving piston  123  that drives nails is housed in the driving cylinder  121  such that it is slidable in the front-rear directions. The driving piston  123  includes a piston body  124  that is disposed so as to be slidable in the driving cylinder  121 , and an elongate driver  125  that is integrally formed with the piston body  124  and extends forward from the piston body  124 . Further, the driving piston  123  linearly moves in the longitudinal direction of the driving cylinder  121  by compressed air that is supplied into a cylinder chamber  121   a . Thus, the driver  125  moves forward within a driving passage  141   a  formed in the driver guide  141  and drives the nail. The piston body  124  and the driver  125  are example embodiments that correspond to the “sliding part” and the “driving part”, respectively, according to the present invention. The cylinder chamber  121   a  is defined as a space surrounded by an inner wall surface of the driving cylinder  121  and a rear surface of the piston body  124 . 
     The driver guide  141  is provided at the front end (right end as viewed in  FIG. 3 ) of the driving cylinder  121 . The magazine  105  is an elongate rectangular member that stores nails. The magazine  105  is disposed at the front end of the body housing  101  or in front of the compression device housing part  101 B and is connected to the driver guide  141 . Further, the magazine  105  has a pusher plate  105   a  for pushing the nails upward as viewed in  FIG. 3 . The pusher plate  105   a  feeds the nails one by one into the driving passage  141   a  of the driver guide  141 . 
     As shown in  FIG. 3 , the compression device  130  is housed in the compression device housing part  101 B of the body housing  101 . The compression device  130  mainly includes a compression cylinder  131  and a compression piston  133  that is disposed in the compression cylinder  131  and can slide in the vertical direction. The compression cylinder  131  and the compression piston  133  are example embodiments that correspond to the “first cylinder” and the “first piston”, respectively, according to the present invention. 
     The compression cylinder  131  is disposed in parallel alongside the magazine  105 . Specifically, the compression cylinder  131  is disposed alongside the longitudinal direction of the magazine  105  and an upper end of the compression cylinder  131  is integrally connected to a front end portion of the driving cylinder  121 . The compression piston  133  is arranged to slide in the vertical direction along the magazine  105 , and the sliding direction of the compression piston  133  is substantially perpendicular to the sliding direction of the driving piston  123 . The volume of a compression chamber  131   a  in the compression cylinder  131  is changed by the sliding movement of the compression piston  133  in the vertical direction. When the compression piston  133  moves upward, the compression piston  133  compresses air in the compression chamber  131   a . The compression chamber  131   a  is defined as a space surrounded by an inner wall surface of the compression cylinder  131  and an upper surface of the compression piston  133 , and is provided adjacent to the driving cylinder  121  in an upper region of the compression cylinder  131 . 
     As shown in  FIG. 3 , the electric motor  111  (see  FIG. 7 ) for driving the compression device  130  is housed in the motor housing part  101 C of the body housing  101 . The electric motor  111  is arranged such that its rotation axis extends substantially in parallel to the axis of the driving cylinder  121 . Therefore, the rotation axis of the electric motor  111  is perpendicular to the sliding direction of the compression piston  133 . Further, a battery mounting region is provided on a lower end of the motor housing part  101 C, and a rechargeable battery pack  110  from which the electric motor  111  is powered is attached to this battery mounting region. The battery pack  110  is an example embodiment that corresponds to the “battery” according to the present invention. 
     The speed of rotation of the electric motor  111  is reduced by a planetary gear type, speed reducing mechanism  113  and then the rotation is converted into linear motion by a crank mechanism  115  serving as a motion converting mechanism and is transmitted to the compression piston  133 . Specifically, the compression device  130  is provided that mainly includes the compression cylinder  131 , the compression piston  133  and the crank mechanism  115 . Further, the speed reducing mechanism  113  and the crank mechanism  115  are housed in an inner housing  102  (also referred to as a gear housing), which is provided in the compression device housing part  101 B and the motor housing part  101 C. 
     The crank mechanism  115  mainly includes a crank shaft  115   a , an eccentric pin  115   b  and a connecting rod  115   c . The crank shaft  115   a  is rotated by the planetary gear type, speed reducing mechanism  113 . The eccentric pin  115   b  is provided at a position displaced from the center of rotation of the crank shaft  115   a . One end of the connecting rod  115   c  is connected to the eccentric pin  115   b  so as to be relatively rotatable, and the other end is connected to the compression piston  133  so as to be relatively rotatable. The crank mechanism  115  is disposed below the compression cylinder  131 . 
     The electric motor  111  is controlled to start and stop by a trigger  103   a  provided on the handle  103  and by the driver guide  141  serving as a contact arm provided in a front end region of the body housing  101 . Specifically, the trigger  103   a , which can be operated by the user&#39;s finger, and a trigger switch  103   b  (see  FIG. 7 ) are provided on the handle  103 ; the trigger switch  103   b  is turned on and off by depressing and releasing the trigger  103   a . When the trigger switch  103   b  is turned on, the electric motor  111  is energized. On the other hand, when the trigger switch  103   b  is turned off, the electric motor  111  is stopped. The trigger  103   a  is arranged to project inward from the handle  103  into the approximately quadrilateral space S surrounded by the handle  103 , the driving mechanism housing part  101 A, the compression device housing part  101 B and the motor housing part  101 C, that is to say, the hollow space surrounded by the driving cylinder  121 , the compression cylinder  131 , the handle  103  and the electric motor  111 . The trigger  103   a  is an example embodiment that corresponds to the “operating member” according to the present invention. 
     The driver guide  141  that serves as the contact arm is arranged such that it can move in the nail driving direction, and is biased towards the front (forward) by a biasing spring  142  (see  FIG. 8 ). When the driver guide  141  is located at a front position, a contact arm switch  143  (see  FIG. 8 ) is turned off. When the driver guide  141  is moved toward the body housing  101  side (to a rear position), the contact arm switch  143  is turned on. The electric motor  111  is energized when both the trigger switch  103   b  and the contact arm switch  143  are turned on, whereas the electric motor  111  is stopped when either one or both of the trigger switch  103   b  and the contact arm switch  143  is/are turned off. 
     As shown in  FIG. 6 , the nailer  100  has an air passage  135  that provides communication between the compression chamber  131   a  (see  FIG. 3 ) of the compression cylinder  131  and the cylinder chamber  121   a  of the driving cylinder  121 , and a valve  137  that opens and closes the air passage  135 . The air passage  135  and the valve  137  are example embodiments that correspond to the “compressed air supply passage” and the “valve member”, respectively, according to the present invention. When the driving piston  123  is moved to a rear end position (to the left as viewed in  FIG. 3 ) and the compression piston  133  is moved to a lower end position (bottom dead center) as shown in  FIG. 3 , the nailer  100  is defined as being located in the initial position. Specifically, the position where the crank angle is zero degrees is the bottom dead center and is defined as the initial position. 
     As shown in  FIG. 6 , the air passage  135  mainly includes a communication port  135   a  open to the compression cylinder  131  side, a communication port  135   b  open to the driving cylinder  121  side, a communication path  135   c  that communicates between the communication ports  135   a ,  135   b , a valve housing space  135   d  and an annular groove  135   e  formed in an inner circumferential surface of the valve housing space  135   d . As shown in  FIG. 4 , the communication port  135   a  is formed in a cylinder head  131   b  of the compression cylinder  131  and communicates with the compression chamber  131   a . As shown in  FIG. 6 , the communication port  135   b  is formed in a cylinder head  121   b  of the driving cylinder  121 . One end of the communication port  135   b  communicates with the communication path  135   c , and the other end communicates with the annular groove  135   e . Specifically, the communication port  135   b  communicates with the valve housing space  135   d  via the annular groove  135   e . As shown in  FIG. 6 , the communication path  135   c  is formed by a pipe-like member and extends in the front-rear direction along the driving cylinder  121 . One end of the communication path  135   c  communicates with the communication port  135   a  and the other end communicates with the communication port  135   b.    
     As shown in  FIG. 6 , the valve  137  is disposed in the valve housing space  135   d . The valve housing space  135   d  has substantially the same inner diameter as the cylinder chamber  121   a  and is formed in the cylinder head  121   b  so as to communicate with the cylinder chamber  121   a . Therefore, the valve  137  disposed in the valve housing space  135   d  is configured as a columnar member having substantially the same diameter as the piston body  124  of the driving piston  123  and arranged to be movable in the front-rear directions on the same axis as a nail-driving axis line (axis of movement) of the driver  125  of the driving piston  123 . By moving in the front-rear directions, the valve  137  provides communication between the compression chamber  131   a  and the cylinder chamber  121   a  or cuts off the communication. In other words, the valve  137  opens and closes the air passage  135 . 
     Specifically, as shown in  FIGS. 8 to 10 , two O-rings  139   a ,  139   b  are provided on an outer periphery of the valve  137 , spaced apart in the front-rear direction. When the front O-ring  139   a  is positioned in front of the annular groove  135   e  and in contact with an inner wall surface of the valve housing space  135   d , communication between the compression chamber  131   a  and the cylinder chamber  121   a  is cut off. Further, when the O-ring  139   a  is moved into the region of the annular groove  135   e  that is spaced from the inner wall surface of the valve housing space  135   d , the compression chamber  131   a  and the cylinder chamber  121   a  communicate with each other.  FIG. 8  shows the state in which the air passage  135  is closed by the valve  137 , and  FIGS. 9 and 10  show the state in which the air passage  135  is opened by the valve  137 . Further, the rear O-ring  139   b  is provided to prevent the compressed air from leaking out through the communication port  135   b  and has no involvement in the communication between the compression chamber  131   a  and the cylinder chamber  121   a . As described above, the valve  137  is provided in a connecting region, which connects with the cylinder chamber  121   a  of the driving cylinder  121 , of the air passage  135 . 
     As shown in  FIGS. 8 to 10 , the valve  137  is normally biased forward by a compression coil spring  138  so as to cut off communication between the compression chamber  131   a  and the cylinder chamber  121   a . Further, a stopper  136  is provided in front of the valve  137 . The stopper  136  is formed by a flange-like member projecting radially inward into the cylinder chamber  121   a  and defines the rear end position of the driving piston  123 , which moves rearward after a driving operation. Further, the stopper  136  defines the front end position of the valve  137  biased forward by the compression coil spring  138 . 
     The valve  137  is configured as a mechanical valve to be controlled by a cylindrical cam  181  (see  FIGS. 3 and 11 ) which rotates in conjunction with the crank mechanism  115 . Rotation of the cylindrical cam  181  is converted into linear motion in the front-rear directions by a link mechanism  185  serving as a relay member and is then transmitted to the valve  137 . As shown in  FIG. 11 , the cylindrical cam  181  is an end face cam having a cam face  181   a  on one side in its axial direction. As shown in  FIG. 3 , the cylindrical cam  181  is fitted onto the crank shaft  115   a  and rotates together with the crank shaft  115   a . The cam face  181   a  is shaped such that the valve  137  is moved rearward and provides communication between the compression chamber  131   a  and the cylinder chamber  121   a  when the air in the compression chamber  131   a  is compressed to the maximum (the crank angle is 180 degrees). 
     As shown in  FIG. 7 , the link mechanism  185  includes a first link  185   a  and a second link  185   b . The first link  185   a  is disposed to extend in the vertical direction along a lateral surface of the compression cylinder  131 . The first link  185   a  is supported substantially at its center in the vertical direction on the inner housing  102  by a support shaft  186  such that the first link  185   a  is pivotable in the front-rear direction. A lower end of the first link  185   a  is in contact with the cam face of the cylindrical cam  181  via a cam follower  187  (see  FIG. 5 ). The second link  185   b  is disposed along a lateral surface of the driving cylinder  121  such that it is movable in the front-rear directions. As shown in  FIGS. 8 to 10 , one end (front end) of the second link  185   b  is connected to an upper end of the first link  185   a  by a pin  189  so as to be relatively rotatable. Further, the other end (rear end) of the second link  185   b  is engaged with an annular engagement recess  137   a  formed in the outer periphery of the valve  137 . 
     Therefore, as shown in  FIG. 7 , when the upper end portion of the first link  185   a  is pivoted forward about the support shaft  186  and the second link  185   b  is moved forward, the valve  137  is moved forward and cuts off communication between the compression chamber  131   a  and the cylinder chamber  121   a  (see  FIG. 8 ). On the other hand, when the upper end portion of the first link  185   a  is pivoted rearward and the second link  185   b  is moved rearward, the valve  137  is moved rearward and provides communication between the compression chamber  131   a  and the cylinder chamber  121   a  (see  FIG. 9 ). Further, the biasing force of the compression coil spring  138 , which biases the valve  137  forward, acts in a direction that presses the cam follower  187  against the cam face  181   a  of the cylindrical cam  181 . 
     In the nailer  100  constructed as described above, which is in the initial position as shown in  FIG. 3 , when the contact arm switch  143  (see  FIG. 8 ) is turned on by pressing the driver guide  141  against the workpiece and the trigger switch  103   b  (see  FIG. 7 ) is turned on by depressing the trigger  103   a , the electric motor  111  is energized. Thus, the crank mechanism  115  is driven via the speed reducing mechanism  113  and the compression piston  133  is moved upward. At this time, as shown in  FIGS. 3 and 8 , communication between the compression chamber  131   a  and the cylinder chamber  121   a  is kept cut off by the valve  137 , so that the air in the compression chamber  131   a  is compressed. 
     When the compression piston  133  reaches near the top dead center or when the air in the compression chamber  131   a  is compressed to the maximum, the valve  137  is moved rearward via the cylindrical cam  181  and the link mechanism  185 , so that the compression chamber  131   a  and the cylinder chamber  121   a  communicate with each other. When the compression chamber  131   a  and the cylinder chamber  121   a  communicate with each other, the compressed air in the compression chamber  131   a  is supplied into the cylinder chamber  121   a , so that the valve  137  is moved to the rear end position as shown in  FIG. 9 . At the same time, the driving piston  123  is moved forward by the compressed air supplied into the cylinder chamber  121   a . Then the driver  125  of the driving piston  123  strikes the nail in the driving passage  141   a  of the driver guide  141  and drives it into the workpiece. 
     The compression piston  133  moves downward after the compressing operation. At this time, the volume of the compression chamber  131   a  is increased so that the pressure in the compression chamber  131   a  is reduced. The pressure in the compression chamber  131   a  acts on the driving piston  123  via the air passage  135  and the cylinder chamber  121   a . By this pressure reduction, as shown in  FIG. 10 , air in the cylinder chamber  121   a  is sucked into the compression chamber  131   a , and the driving piston  123  is moved rearward and comes into contact with the stopper  136 . Thus, the driving piston  123  is returned to the initial position. The valve  137  maintains the communication between the compression chamber  131   a  and the cylinder chamber  121   a  until the driving piston  123  has returned to the initial position. However, when the compression piston  133  comes close to the initial position or the bottom dead center, the valve  137  is moved forward by the biasing force of the compression coil spring  138  and cuts off the communication between the compression chamber  131   a  and the cylinder chamber  121   a . Further, when the compression piston  133  is returned to the initial position, the supply of current to the electric motor  111  is interrupted and the electric motor  111  is stopped even if the trigger switch  103   b  and the contact arm switch  143  are held in the on state. One cycle of the nail driving operation is completed in this manner. 
     According to the above-described embodiment, the compression cylinder  131  and the compression piston  133 , which form the compression device  130 , are disposed alongside the magazine  105 . Specifically, the compression device  130  is disposed in the front region of the nailer  100 , thereby avoiding that the compression device  130  protrudes rearward of the nailer  100 . As a result, the length of the nailer  100  in the front-rear direction or the overall length of the nailer  100  is shortened, so that a size reduction of the nailer  100  can be realized. 
     In addition, according to this embodiment as well, because the compression device  130  is disposed in the front region of the nailer  100 , the degree of freedom increases in the arrangement and configuration of the handle  103  that is disposed at the rear region of the driving cylinder  121 . Specifically, the handle  103  is arranged to be located closer to the nail-driving axis line of the driver  125 . Therefore, the recoil force generated during the nail driving operation by the driver  125  can be easily controlled by the user&#39;s hand. In addition, the user can efficiently apply a pressing force against the workpiece. Further, the trigger  103   a  on the handle  103  can also be disposed closer to the driving cylinder  121 . Therefore, the operability of the trigger  103  can be improved. 
     In addition, according to this embodiment, because the magazine  105  and the compression cylinder  131  are disposed adjacent to each other, a rational arrangement can be realized with no dead space. In this case, the magazine  105  and the compression cylinder  131  are preferably disposed in parallel to each other. Therefore, for example, in the nailer  100  in which the magazine  105  is disposed obliquely to the nail-driving axis line of the driver  125 , the compression cylinder  131  is also disposed obliquely to the nail-driving axis line. 
     In addition, according to this embodiment, because the communication path  135   c  connects the compression chamber  131   a  of the compression cylinder  131  and the cylinder chamber  121   a  of the driving cylinder  121 , the degree of freedom increases in the relative arrangement of the compression cylinder  131  and the driving cylinder  121 . In this case, the cylindrical member forming the communication path  135   c  is disposed alongside the driving cylinder  121 , so that the cylindrical member avoids interference with other components. Further, the cylindrical member may be formed of a hard material or may be formed of a flexible material, which can be freely bent during assembly. 
     In addition, in this embodiment, in the air passage  135  that connects the compression chamber  131   a  of the compression cylinder  131  and the cylinder chamber  121   a  of the driving cylinder  121 , the valve  137  is disposed in a connecting region that connects with the cylinder chamber  121   a . Thus, the air passage  135  forms a portion of the compression chamber  131   a . Therefore, while the compressed air is being supplied into the cylinder chamber  121   a  of the driving cylinder  121 , the compressed air is prevented from expanding. Specifically, energy losses of the compressed air are reduced. As a result, the nail driving operation is performed with excellent energy efficiency. 
     In addition, according to this embodiment, because the compression cylinder  131 , the driving cylinder  121 , the handle  103  and the electric motor  111  are arranged to form an approximately quadrilateral shape and are connected to each other, the stiffness of the nailer  100  can be increased. Therefore, damage to the nailer  100  by external forces is prevented. 
     In addition, according to this embodiment, the electric motor  111  and the battery pack  110  are disposed at the lower end side of the handle  103 . Thus, the electrical system can be rationally arranged all in one region. Further, in case the weight ratio of the electric motor  111  and the battery pack  110 , which are provided at the lower end side of the handle  103 , to the driving cylinder  121 , which is connected to the upper end of the handle  103 , is set to about one, the center of gravity of the nailer  100  is set substantially in the middle of the handle  103 , so that operability of the nailer  100  is improved. 
     In the above-described embodiment, the cylindrical cam  181  is configured as an end face cam, but a cylindrical grooved cam having a groove on its outer circumferential surface may be used in place of the end face cam. 
     In addition, in the above-described embodiment, the valve  137  is configured as a mechanical valve which is controlled by the cylindrical cam  181 , but it is not limited thereto. For example, as shown in  FIG. 12 , an electrically controllable solenoid valve  145  may be used in place of the mechanical valve. The solenoid valve  145  mainly includes a valve body  145 A, which can move in the front-rear directions, and an electromagnet  145 B that moves the valve body  145 A. For example, when the air in the compression chamber  131   a  is compressed to the maximum, the electromagnet  145 B moves the valve body  145   a  rearward and provides communication between the compression chamber  131   a  and the cylinder chamber  121   a . Further, when the compression piston  133  comes close to the bottom dead center, the electromagnet  145 B moves the valve body  145   a  forward and cuts off the communication between the compression chamber  131   a  and the cylinder chamber  121   a . By provision of a position sensor, for example, that detects the rotational position of the crank shaft  115   a  of the crank mechanism  115 , which drives the compression piston  133 , the electromagnet  145 B is controlled by a controller based on the detected rotational position of the crank shaft  115   a.    
     Although the above-described embodiment described the nailer  100  as an example of the driving tool, it may also be applied to driving tools, other than nailers, known as tackers and staplers. 
     In view of the object of the above-described invention, driving tools according to the present invention can be configured according to the following aspects. 
     (Aspect 1) 
     A driving tool that performs a driving operation of a struck material, comprising: 
     a first cylinder, 
     a first piston that is disposed so as to be slidable within the first cylinder and generates compressed air in the first cylinder, 
     a motor that drives the first piston, 
     a second cylinder, 
     a second piston that is disposed so as to be slidable within the second cylinder and has a sliding part and an elongate driving part connected to the sliding part, 
     a handle, and 
     a magazine that is configured to feed the struck material onto an axis of movement of the driving part, wherein: 
     the compressed air in the first cylinder is supplied into the second cylinder and the second piston is linearly moved toward a front end of the second cylinder by the compressed air, whereby the driving part drives the struck material, and 
     the first cylinder is arranged to intersect a longitudinal axis of the second cylinder and extend alongside a longitudinal axis of the magazine, 
     the first piston is configured to slide in a direction alongside the longitudinal axis of the magazine, and 
     the handle is disposed on an opposite side of the first cylinder from the magazine with reference to the direction that the axis of movement of the driving part extends. 
     (Aspect 2) 
     The driving tool as defined in claim  1  or Aspect 1, wherein the first cylinder is disposed in parallel to the magazine. 
     (Correspondences Between the Features of the Embodiment and the Features of the Invention) 
     The above-described embodiment is merely an example of a mode for carrying out the present invention. Accordingly, the present invention is not limited to the structure of the embodiment. Correspondences between the features of the embodiment and the features of the invention are as follows. 
     The nailer  100  is an example embodiment that corresponds to the “driving tool” according to the present invention. 
     The handle  103  is an example embodiment that corresponds to the “handle” according to the present invention. 
     The trigger  103   a  is an example embodiment that corresponds to the “operating member” according to the present invention. 
     The magazine  105  is an example embodiment that corresponds to the “magazine” according to the present invention. 
     The battery pack  110  is an example embodiment that corresponds to the “battery” according to the present invention. 
     The electric motor  111  is an example embodiment that corresponds to the “motor” according to the present invention. 
     The driving cylinder  121  is an example embodiment that corresponds to the “second cylinder” according to the present invention. 
     The driving piston  123  is an example embodiment that corresponds to the “second piston” according to the present invention. 
     The piston body  124  is an example embodiment that corresponds to the “sliding part” according to the present invention. 
     The driver  125  is an example embodiment that corresponds to the “driving part” according to the present invention. 
     The compression cylinder  131  is an example embodiment that corresponds to the “first cylinder” according to the present invention. 
     The compression piston  133  is an example embodiment that corresponds to the “first piston” according to the present invention. 
     The air passage  135  is an example embodiment that corresponds to the “compressed air supply passage” according to the present invention. 
     The valve  137  is an example embodiment that corresponds to the “valve member” according to the present invention. 
     EXPLANATION OF THE NUMERALS 
       100  nailer 
       101  body housing 
       101 A driving mechanism housing part 
       101 B compression device housing part 
       101 C motor housing part 
       102  inner housing 
       103  handle 
       103   a  trigger 
       103   b  trigger switch 
       105  magazine 
       105   a  pusher plate 
       110  battery pack 
       111  electric motor 
       113  planetary gear type, speed reducing mechanism 
       115  crank mechanism 
       115   a  crank shaft 
       115   b  eccentric pin 
       115   c  connecting rod 
       120  nail driving mechanism 
       121  driving cylinder 
       121   a  cylinder chamber 
       121   b  cylinder head 
       135   e  annular groove 
       123  driving piston 
       124  piston body 
       125  driver 
       130  compression device 
       131  compression cylinder 
       131   a  compression chamber 
       131   b  cylinder head 
       133  compression piston 
       135  air passage 
       135   a  communication port 
       135   b  communication port 
       135   c  communication path 
       136  stopper 
       137  valve 
       137   a  engagement recess 
       138  compression coil spring 
       139   a ,  139   b  O-ring 
       141  driver guide 
       141   a  driving passage 
       142  biasing spring 
       143  contact arm switch 
       145  solenoid valve 
       145 A valve body 
       145 B electromagnet 
       181  cylindrical cam 
       181   a  cam face 
       185  link mechanism 
       185   a  first link 
       185   b  second link 
       186  support shaft 
       187  cam follower 
       189  pin 
     S hollow space