Patent Application
20140014385
The present application claims priorities from Japanese Patent Application No. 2012-158175 filed on Jul. 14, 2012, Japanese Patent Application No. 2012-213267 filed on Sep. 26, 2012, and Japanese Patent Application No. 2012-256999 filed on Nov. 25, 2012, the contents of which are hereby incorporated by reference into this application.
The present invention relates to operability improvement, downsizing, and weight reduction of a power tool that uses a storage battery as a drive source. The power tool is comprised of a motor part, a resin-made housing housing a speed reducing mechanism part, etc. that transmits the rotative force generated by the motor part, and a handle turnably provided at the housing.
As a conventional switch structure of a so-called foldable power tool, the technique of Japanese Patent Application Laid-Open Publication No. 2011-73087 (Patent Literature 1) using a switch (SW) turnable about a rotation shaft of a tool retaining part is known. In Patent Literature 1, the tool is comprised of a halved resin-made main housing (front-side housing), which houses a motor part, a speed reducing mechanism part transmitting the rotative force generated by the motor part, etc., and a handle housing (rear-side housing), which is turnably connected and houses a battery in an internal space; and a switch for turning on or off the motor is provided in the main housing side.
A switch 206, which turns on or off the rotation of the motor 204, is provided in the space which is in the rear side of the motor 204 of the main housing 202 and in the front side of the turning shaft 210. The switch 206 is connected to a lever part 207, which is moved in the circumferential direction of the main housing 202 having a cylindrical shape. When the lever part 207 is moved in a first direction of the circumferential direction, the motor 204 is rotated in a forward direction (direction in which a screw is tightened with a tip tool (bit)); and, when the lever part 207 is moved in a second direction, the motor 204 is rotated in a reverse direction (direction in which a screw is loosened with the tip tool). The switch 206 sets either ON or OFF of the motor 204 and causes the motor 204 to rotate at a determined speed by obtaining the ON state, but is not capable of adjusting the speed of the rotation of the motor 204.
The handle housing 203 is a housing, which houses a battery 230 and serves as a grip part to be grasped (held) by an operator; and the handle housing is formed in a substantially cylindrical shape having an opening 203c at a rear end and is manufactured by a left-right division style by integral molding of a polymer resin product such as plastic. The main housing 202 and the handle housing 203 are coupled to each other so as to be turnable about the turning shaft 210 by about 70 degrees. The battery 230 housed in the handle housing 203 is formed by a so-called battery pack method by which it is attachable/detachable through the opening 203c, and a latch part 231 is provided in the rear side thereof. The rear surface of the battery 230 forms part of an outer edge part of the handle housing 203, and a metal-made connector 232 is provided at a substantially rectangular corner part at the front end thereof.
A terminal base 211 is provided in the handle housing 203, and a plurality of metal-made terminals 212 are fixed thereto. When the connector 232 is brought into contact with the plurality of terminals 212 in the power tool 201 side by attaching the battery 230 to the interior of the handle housing 203, a state that electric power can be supplied from the battery 230 to the motor 204 is obtained. The vicinity of the lower side of the turning shaft 210 serves as the space for allowing extension of a lead wire 209a, which is an power supply line from the terminal 212 to the motor 204, and a lead wire 209b, which supplies electric power to a LED 214 for irradiating the vicinity of the tip tool; and a cover 215 is provided for covering the space. The cover 215 is a plate-like member, which is fixed to the main housing 202 side by a turning shaft 216. In the front side of the terminal base 211 of the handle housing 203, housing space 217 for housing the cover 215 when the housing is folded is formed.
In the power tool of the conventional technique, the lever part 207, which controls supply/stoppage of electric power to the motor 204, is disposed on the main housing 202 side, and the switch 206, which controls supply/stoppage of electric power to the motor 204, is also provided on the main housing 202 side. Therefore, in the aspect as described in
In the power tool as described above, when the switch 206 is provided in the handle housing 203 side, the switch has to be disposed in the vicinity of the position (housing space 217) to which the cover 215 enters in the gun-type shape; therefore, the switch and the cover 215 interfere with each other. In order to prevent the interference, the handle housing 203 has to be extended in the central-axis direction (=front-rear direction), the size of the power tool is increased, and portability is lost. Furthermore, when used in the folded state, the both lateral surfaces of the main housing are held with the thumb and the forefinger, and a switch operation is carried out with the right hand; therefore, there has been a risk that the holding state of the tool main body becomes unstable during the operation of the switch, and the stability of the output shaft may be reduced.
It is a preferred aim of the present invention to provide a foldable-type power tool having an easy-to-use switch mechanism in which the position of a switch is moved to a handle housing side.
It is another object of the present invention to provide a power tool which is a foldable type and is configured to be able to firmly retain a housing main body so that an output shaft is stabled and operations are enabled.
It is another preferred aim of the present invention to provide a power tool which has reduced the risk of squeezing of a finger(s) in the vicinity of a hinge of a main housing and a handle housing upon folding.
It is another preferred aim of the present invention to provide a power tool which is a foldable type and is configured to be able to firmly retain the housing main body so as to stabilize the output shaft and enable operations.
It is a still another preferred aim of the present invention to provide a power tool which has reduced the risk of squeezing of a finger(s) in the vicinity of the hinge of the main housing and the handle housing.
According to one feature of the present invention, a power tool has: a handle housing that houses a battery and has a first grip part; a motor that is driven by electric power of the battery; an output shaft to which a tip tool is attached; a power transmission system that transmits rotative force of the motor to the output shaft; a main housing that houses the motor and the power transmission system and has a second grip part; and a turning mechanism that is turnably connected at a rear end part of the main housing and a front end part of the handle housing; the power tool operable in at least a state that the main housing and the handle housing are disposed straight and a state that the main housing and the handle housing are disposed to be folded; in which, in the state that the handle housing is folded, the second grip part is positioned in front of the first grip part in an axial direction of the main housing. A switch and a trigger that control rotation of the motor are provided in the rear of the turning mechanism of the handle housing.
According to another feature of the present invention, the first and second grip parts are formed of a material having higher elasticity than that of the handle housing and the main housing, and the second grip part is provided on each of left-right lateral surfaces of the main housing. The second grip part forms a curved surface serving as a surface curved in an opposite direction of an outer peripheral surface of the main housing having a substantially cylindrical shape. The first and second grip parts are manufactured by two-layer molding with the handle housing and the main housing. An upper end surface of the handle housing has a first recessed part having a length longer than the width of two fingers. In the upper end surface of the handle housing, a second recessed part is formed in the vicinity of the rear of the trigger.
In this manner, according to the present invention, in the state in which the handle housing is folded, the second grip part is serially aligned in front of a part of the first grip part in the axial direction of the main housing. Therefore, in the state in which the operator is holding the handle housing, the second grip part of the main housing can be held from both left-right side in a manner that the thumb and the forefinger are stretched toward the main housing side, the stability of the output shaft can be maintained while firmly holding the main body of the power tool, and highly precise reliable operations can be carried out.
Moreover, in the immediately rear of the turning mechanism of the handle housing, the switch and the trigger that control the rotation of the motor are provided. Therefore, even when the housing is folded to form the gun type to carry out an operation, the trigger can be disposed at an easy-to-use position, and the main housing can be configured to be compact.
Furthermore, the first and second grip parts are formed of a material having higher elasticity than that of the handle housing and the main housing. Therefore, a power tool that does not easily cause slippage which leads to reduction of fatigue of the holding fingers can be achieved.
Hereinafter, an embodiment of the present invention will be described based on the drawings. In the drawings described below, the same parts are denoted by the same symbols, and repetitive explanations thereof will be omitted.
A power tool 1 uses a chargeable and attachable/detachable battery pack 60 as an electric power source, uses an unillustrated motor as a drive source to apply rotative force and striking force to an output shaft via a power transmission system, and carries out operations such as screw tightening and bolt tightening by transmitting the rotative force or striking force to a tip tool such as a driver bit 58 retained by an attachment hole covered with a sleeve 57. A housing of the power tool 1 consists of a main housing (front housing) 10 and a handle housing (rear housing) 20. The main housing 10 is formed by integral molding of a polymer resin such as plastic so as to be dividable into two to the left and the right, and the left-right parts are fixed by unillustrated screws. The handle housing 20 is formed to have a cylindrical shape having an opening 20c at a rear end and is manufactured by a left-right division style by integral molding of a polymer resin such as plastic.
The main housing 10 and the handle housing 20 are coupled to each other by a turning mechanism having an unillustrated turning shaft in the vicinity of the center of the front-rear direction and is turnable about the turning shaft by about 70 degrees. The plane that turns is the plane including the front-rear and top-bottom directions viewed in
The power tool 1 of
To detach the battery pack 60, the battery pack 60 is pulled out from the opening 20c while pushing latch parts 61 provided at two locations on the left and the right. The shape of the rear end of the battery pack 60 is formed so as to cover the opening 20c of the handle housing 20, and the rear surface of the battery pack 60 forms part of an outer edge part of the handle housing 20. A plurality of lithium-ion cells of, for example, 18650 or 14500 are housed in the battery pack 60; however, the sizes, types, numbers, etc. of the batteries may be optionally set.
In the space of the part that is in the handle housing 20 and is adjacent to the turning mechanism, a trigger 7, which operates a switch (main switch) for controlling supply/stoppage of electric power to the motor, and a forward/reverse switching lever 8 for switching the rotation direction of the motor are housed. In the present embodiment, the main switch is a so-called variable resistance switch in which the resistance value thereof is varied depending on the operation amount of the trigger 7 and is configured so that the rotation speed of the motor is varied depending on the operation amount of the trigger 7. The trigger 7 has a trigger body part 7a having a width around which a finger can be hooked, and the rear end of the trigger 7 is configured to be swingable substantially in the top-bottom direction when the front side thereof swings (turns) about an axis point (swinging shaft 43) by a predetermined angle.
The forward/reverse switching lever 8 is provided substantially above the swinging shaft 43 of the trigger 7. The forward/reverse switching lever 8 is connected to a switch for switching the rotation direction of the motor to a “forward rotation direction (tightening direction)” and a “reverse rotation direction (loosening direction)”. The forward/reverse switching lever 8 can be operated by sliding in the left-right direction. Meanwhile, it is preferred to achieve a mechanical or electrical lock mechanism by providing not only lever positions at the two locations corresponding to a forward-rotation-direction position and a reverse-rotation-direction position but also providing a lock position between the two locations so that, at the lock position, the trigger 7 is locked to be mechanically not movable or the motor is not electrically turned on even when the trigger 7 is pulled. A concave part 24, which is hollowed from an outer part of the handle housing 20 toward the inner side, is provided in the periphery of the forward/reverse switching lever 8 to configure so that forward/reverse switching lever 8 after operation is not projected from the outer part of the handle housing 20 to the outer side. A specific configuration of the concave part 24 will be described later.
The handle housing 20 serves as a part that is mainly held by the operator and has a function of a base member which forms a first grip part. Therefore, the handle housing has a shape that fits a hand when being held by the operator, and, in the upper side of the handle housing, two gently recessed parts (concaves) 23b and 23d are formed from a front end 23a to a rear step part 23e. When the directions of the handle housing 20 are mentioned in the present specification, they are viewed based on the case in which the power tool 1 is in the straight shape as shown in
The part between the recessed part 23b and the recessed part 23d is configured so that the boundary between the front/rear concaves can be found out by a flexion point 23c. As a result of providing the flexion point 23c, when the operator holds the handle housing 20, by which part of the grip part he/she is holding can be found out by tactile sensation. A lower part of web spaces of fingers on which the largest force acts can be guided by the first recessed part 23b; therefore, the grip part having good workability can be provided. In this case, as the shape of the handle housing 20, the two gently recessed parts (concaves) 23b and 23d are formed, and elastic bodies 21 and 22 serving as the first grip part are formed.
The elastic bodies 21 and 22 are constituent materials having higher elasticity than those of the constituent material (plastic) of the handle housing 20 and are formed as thin surface layers of a resin having high elasticity on a lower layer serving as the constituent material of the handle housing 20 by using, for example, techniques of two-layer molding. Since publicly known techniques can be used as the manufacturing technique of the two-layer molding, detailed explanations thereof will be omitted. The part on which the elastic body 22 formed at a position separated from the elastic body 21 also forms part of the first grip part. The elastic body 22 also forms two recessed parts and a flexion point from the vicinity of the front end thereof to the vicinity of the rear end thereof, and the detailed shapes thereof will be described later. The first grip part of the present embodiment is formed by the elastic bodies 21 and 22, which are disposed to be separated from each other; however, the first grip part is not limited to this shape, but may be configured to have a shape coupling the elastic bodies 21 and 22 or configured so as to be divided into three or more and dispersedly disposed.
The main housing 10 is subsidiarily held by the operator in some cases, and a second grip part is therefore formed also in the main housing 10 side. The second grip part is a part in which an elastic body 11 is formed. The elastic body 11 is also a constituent material having higher elasticity than that of the constituent material (plastic) of the main housing 10 and is formed as a thin surface layer of a resin of a resin having high elasticity on a lower layer serving as the constituent material of the main housing 10 by using, for example, techniques of two-layer molding. Moreover, the shape of a particular area of the elastic body 11 is arranged and configured so that force easily acts on the main housing 10 via a holding finger(s) when held by the operator.
Non-slip treated parts 11a and 11b are formed in particular parts of the elastic body 11. The non-slip treated parts 11a and 11b are formed at the same positions also on the right-side lateral surface of the main housing 10. The non-slip treated parts 11a and 11b are formed by, for example, a plurality of small recessed parts formed on the elastic body 11. The non-slip treated parts are not limited only to recessed parts but also may be formed by convex parts, grooves, steps, etc. since an object thereof is to prevent slipping. Furthermore, only the non-slip treated parts 11a and 11b may be formed of a further another material (third material). The elastic body 11 serving as the second grip part is similarly formed also on the right-side lateral surface (not illustrated) as well as the illustrated left-side lateral surface and is bilaterally symmetrical and coupled on the upper side.
A cover 45 is disposed on the lower side of the turning center by which the main housing 10 and the handle housing 20 are folded (the side in which a narrow angle is formed). The cover 45 is a plate-like member. When the power tool 1 is used in the mode shown in
Next, the internal structure of the power tool 1 will be explained by using a partial cross-sectional view of
In the present embodiment, the power transmission system is comprised of a speed reducing mechanism 38, which uses planetary wheels, and the striking mechanism 30 having a hammer 32 and an anvil 35, and is serially disposed having the same axis as the motor 4. The speed reducing mechanism 38 has a sun gear attached to the rotation shaft of the motor 4, a plurality of planetary gears, and a fixed-type ring gear on the outer peripheral side of the planetary gears. In the speed reducing mechanism 38, a planetary carrier fixing a rotation shaft of the plurality of planetary gears is rotated. A widely used publicly-known striking mechanism (impact mechanism) can be used as the striking mechanism 30. The striking mechanism 30 is comprised of: a spindle 31, which is connected to the planetary carrier; a hammer 32, which is movable in an axial direction; a spring 34, which biases the hammer 32; cam grooves; balls; etc. A spindle lock mechanism 39, which prevents relative rotation of an output shaft 56 with respect to the main housing 10 when the motor 4 is stopped, is provided between the striking mechanism 30 and the sleeve 57. The spindle lock mechanism 39 is a lock mechanism for carrying out hand tightening by rotating the power tool 1 as if the power tool is a driver after rotation of the motor 4 is stopped. Since a specific structure of the spindle lock mechanism 39 is publicly known, the explanation thereof is omitted herein.
A connector (terminal) 62 is provided at a substantially rectangular corner part at the front end of the battery pack 60. On the other hand, a plurality of metal-made terminals 15 are fixed to a terminal base 14 of the handle housing 20. When the battery pack 60 is attached to the interior of the handle housing 20, the connector 62 is brought into contact with the plurality of terminals 15 on the power tool 1 side. As a result, a state in which electric power from the battery pack 60 can be supplied to the motor 4 is obtained. The switch (main switch) for controlling supply/stoppage of electric power to the motor 4, and a forward/reverse switch for switching the rotation direction of the motor 4 are housed in the space that is in the handle housing 20 and between the battery pack 60 and a turning shaft 9.
In the present embodiment, the switch 6 is a so-called variable resistance switch in which the resistance value thereof is varied depending on the operation amount of the trigger 7 and is configured so that the rotation speed of the motor 4 is varied depending on the operation amount of the trigger 7. The front side of the trigger 7 is configured to be swayed (turned) only by a predetermined angle about the swinging shaft (swing supporting point) 43 so that the rear part of the trigger 7 is practically movable in the top-bottom direction. A compressed spring 6b is provided between the trigger 7 and the switch 6; and, when the trigger 7 is set free, the trigger 7 is moved in the direction in which the switch 6 is released. In the present embodiment, the swinging shaft 43 is provided on the front side of the trigger 7; therefore, the operator who holds the handle housing 20, which forms the first grip part, can easily hold the trigger 7, and the power tool 1 having an easy-to-use switch mechanism is achieved.
The forward/reverse switching lever 8 is provided in the space which is on the front side of the switch 6 and between the switch 6 and the turning shaft 9. The cover 45 is disposed in the vicinity of the turning shaft 9 and in the side toward which the main housing 10 and the handle housing 20 are folded (the side in which a narrow angle is formed). In a way opposite to that of the power tool shown in
Particularly, in the power tool in which the battery pack 60 is disposed in the handle housing 20, a lead wire 37a, which supplies electric power to the motor 4, and a lead wire 37b, which supplies electric power to an LED 14, have to be disposed in the vicinity of the turning shaft 9; therefore, the power tool has the structure which is provided with the space for allowing their extension. Note that, since the cross section of the cover 45 perpendicular to the axial direction thereof includes an opening having an upright U-shape, the height of the cover 45 (lateral surface of the cover 45) and the height of a housing space 47 (substantially equal to the cross section of the center part of the cover 45) do not match with each other when viewed in
As is understood in
Furthermore, the main housing 10 is not required to house the switch mechanism between the motor 4 and the turning shaft 9 different from the conventional technique shown in
Next, an operation state in the case in which the power tool 1 according to the embodiment of the present invention is straight will be explained with reference to
Again returning to
The upper-side coupled part of the elastic body 11 is gripped by the vicinities of the distal ends of the ring finger 104 and the little finger 105; therefore, gripping it is comfortable and it facilitates operation. In this way of gripping, the forward/reverse switching lever 8 can be easily operated by moving the thumb 101 or the forefinger 102, and there is no need to largely separate the hand from the main housing 10 or the handle housing 20.
Next, an operation state of a case in which the power tool 1 according to the embodiment of the present invention is folded will be described with reference to
Moreover, since the protruding part 12 protruding to the lower side of the main housing 10 by about a distance H is provided, the middle finger 103 can be naturally guided to the center of the body part 7a of the trigger 7 by the protruding part 12. The trigger 7 can be operated by carrying out a pulling operation of the middle finger 103 in the central-axis direction of the first grip part, and variable speed drive of the motor 4 can be easily carried out.
As is understood from the cross-sectional view of
Next, a detailed shape of the handle housing 20 will be described with reference to
The second recessed part 23d is formed also from the flexion point 23c to the rear side (the vicinity of the rear of the trigger 7); however, the recessed part 23d rather has a substantially the same height as the flexion point 23c than being a concave, and the rear step part 23e is higher than them in this state. The vicinity of the center of the grip part is configured to be recognizable by a tactile sensation by the flexion point 23c, and the vicinity of the rear end of the grip part is configured to be recognizable by the rear step part 23e. If the frontend 23a and the rear step part 23e are connected to each other by a straight line, the flexion point 23c is hollowed by about D1. The elastic body 21 is disposed up to a rear end part 23f, which is positioned in the vicinity of the opening 20c of the handle housing 20.
In the shape of the part (lower side) of the elastic body 22 of the handle housing 20, mainly two recessed parts 26c and 26e are formed. In this case, when viewed from a flexion point 26d, the recessed part 26c is formed on the front side, and the recessed part 26c is formed on the rear side. A front end 26a of the elastic body 22 is positioned in the vicinity of the swinging shaft 43 of the trigger 7 (see
As described above, in the case of the gun-type shape and the gripping method shown in
Also when the forward/reverse switching lever 8 is to be operated, the handle housing 20 can be retained by the middle finger 103, the ring finger 104, and the little finger 105; therefore, there is no need to switch the way of holding the power tool 1 or to support the power tool 1 with the left hand. Furthermore, the vicinity of the rear end of the lower side of the main housing 10 is configured to have a flat surface, i.e., the protruding part 12 protruding to the lower side of the vicinity of a bottom surface part 10c. Since the protruding part 12 is formed, only by lifting up the power tool 1 with one hand and bending the forefinger, in the case of holding with the right hand, along the lower end surface of the main housing 10, the forefinger can be guided to an appropriate position in front of the trigger 7. Therefore, usability can be further improved.
Since the shapes chamfered (beveled) in this manner are used, when the handle housing 20 is turned with respect to the main housing 10, most of the vicinities of the rear end surfaces of the hatched parts 13 and 28 are not brought into contact with each other. A protruding part 25a protruding downward is formed in the vicinity of the front end of the trigger 7, and a protruding part (trigger tongue) 25b protruding downward is formed in the vicinity of the rear end of the trigger 7 so that they exert effect of preventing slippage of the finger(s), which is retaining the power tool 1, and guiding the finger(s) of the operator to a predetermined position (the trigger 7 or the elastic body 22).
The push-type forward/reverse switching lever 8 exposed to the both lateral surfaces of the handle housing 20 is disposed in the tapered concave 24 and is configured to be a short lever so as not to interfere with the hand(s) and fingers gripping the handle housing 20. Therefore, the operator is capable of easily carrying out a switching operation while holding the first grip part (the elastic bodies 21 and 22) and is capable of preventing unintentional application of force to the forward/reverse switching lever 8 while carrying out a tightening operation. It is preferred to mechanically lock the lever so that the forward/reverse switching lever 8 cannot be moved while the trigger 7 is being pulled or use a configuration so as to electrically lock the lever so that the lever is not reacted even when the forward/reverse switching lever 8 is moved.
Furthermore, the protruding part 25a is formed above the trigger 7; therefore, even if the forefinger, etc. are in the vicinity of the trigger 7 upon folding, the forefinger can be naturally guided to the pressing surface of the trigger 7 in combination with the shape of the protruding parts 12 and 25a without squeezing the finger(s) in the vicinities of the hatched parts 13 and 28. Note that the protruding part 25a is caused to protrude mainly for housing the swinging shaft 43, and the protruding part 25b is provided for guiding the gripping finger(s). The elastic body 22 is formed up to the vicinity of the lower side of the protruding part 25b; therefore, the finger which pulls the trigger 7 can be positioned at a predetermined position, and a comfortable gripping feeling is achieved by the elastic body 22, which is a soft material. A hatched part 29 also has a shape chamfered (beveled) so that a step or unevenness from the trigger 7 to the elastic body 22 is eliminated.
As described above, according to the present embodiment, the vicinity of a hinge mechanism (turning mechanism) mutually coupling the grip parts of the main housing 10 and the handle housing 20 has a shape which has an effect of pushing the finger(s) to the outside upon turning, and the end faces thereof (the vicinities of the hatched parts 13 and 28) are formed at the angle (θ) by which the end faces are mutually bidirectionally parallel or not intersected; therefore, the finger(s) can be effectively prevented from being squeezed therein. The angle (θ) is about 20 degrees in the present embodiment, but maybe suitably set in a range about 10 to 30 degrees.
Next, a second embodiment will be described with reference to
In the shape of the upper side of the handle housing 80, a flexion point 83c is provided between the front end 83a and the rear end 83f, a recessed part 83b is provided on the front side of the flexion point 83c, and a recessed part 83d is formed on the rear side of the flexion point 83c and between there and step part 83e. The front-rear-direction width of the recessed part 83b is preferred to have a length corresponding to about the total of the forefinger 102 and the middle finger 103. The recessed part 83b is not required to be largely hollowed; and the recessed part 83b may be substantially a slight concave as shown in
In the lower part of the elastic body 81 of the handle housing 80, a lower front end 86a is positioned on the rear side of a trigger 77. A concave 86b, which substantially accommodates the middle finger 103, is formed on the immediately rear side of the lower front end 86a, and, in the rear thereof, a smooth surface (curved surface) is formed from a flexion point 86c to a step part 86d. A hook hole 87 is formed immediately behind the step part 86d, and the elastic body 81 is configured so as to reach a lower rear end 86e in the rear side of the hook hole 87. A protruding part 85a is formed on the front side of the trigger 77, and a forward/reverse switching lever 78 is disposed thereabove. The shape of an elastic body 71 serving as a second grip part formed in the main housing 70 side is substantially similar to that of the elastic body 11 of the first embodiment; however, the shapes of recessed parts 71a and 71b serving as non-slip treated parts are somewhat different from those of the first embodiment. However, the difference thereof is derived from design factors, and the shape of the elastic body 71 and the recessed parts 71a and 71b shown in
Next, a third embodiment will be described with reference to
The rear housing 302 is formed to have a cylindrical shape having an opening 302c at the rear end thereof and is manufactured by a left-right division style by integral molding of a polymer resin product such as plastic. The front housing 303 and the rear housing 302 are coupled to each other by a turning shaft 310 and are turnable about the turning shaft 310 by about 70 degrees. The plane that turns is the plane including the front-rear and top-bottom directions as viewed in
The motor 304 is a brushed DC motor used as a drive source for rotating the unillustrated tip tool and is housed on the rear side of the front housing 303. In the present embodiment, the battery pack 330 is used as an electric power source for driving the motor 304. A rotation shaft of the motor 304 is connected to a power transmission system for rotating the tip tool. In the present embodiment, the power transmission system is comprised of a speed reducing mechanism 318, which uses planetary wheels, and a striking mechanism 320 having a hammer 322 and an anvil 325, and they are serially disposed to have the same axis as the motor 304.
The speed reducing mechanism 318 has a sun gear attached to the rotation shaft of the motor 304, a plurality of planetary gears, and a fixed-type ring gear on the outer peripheral side of the planetary gears. In the speed reducing mechanism 318, a planetary carrier for fixing a rotation shaft of the plurality of planetary gears is rotated. A widely used publicly-known striking mechanism (impact mechanism) can be used as the striking mechanism 320. The striking mechanism 320 is comprised of: a spindle 321, which is connected to the planetary carrier; a hammer 322, which is movable in an axial direction; a spring 324, which biases the hammer 322; cam grooves; balls; etc. A spindle lock mechanism 319, which prevents relative rotation of an output shaft 326 with respect to the front housing 303 when the motor 304 is stopped, is provided between the striking mechanism 320 and the sleeve 327. The spindle lock mechanism 319 is a lock mechanism for carrying out hand tightening by rotating the power tool 301 as if the power tool is a driver after rotation of the motor 304 is stopped. Since a specific structure of the spindle lock mechanism 319 is publicly known, the explanation thereof is omitted herein.
The battery pack 330 has a substantially cylindrical chassis, which is attachable and detachable to and from internal space through the opening 302c of the end part of the rear housing 302, and the battery pack is an electric power source which is of a so-called cassette type and easily replaceable. Hooking parts 331a are provided at two locations on the chassis of the battery pack 330, and, when they are engaged with recessed parts (not illustrated) formed on the inner wall of the rear housing 302, the battery pack 330 is retained. In order to detach the battery pack 330, the battery pack 330 is pulled from the opening 302c while pressing latch parts 331 provided at two locations on the left and the right. The shape of the rear end part of the battery pack 330 is formed so as to cover the opening 302c of the rear housing 302, and the rear surface of the battery pack 330 forms part of an outer edge part of the rear housing 302. A connector 332 is provided at a substantially rectangular corner part of the front end of the battery pack 330, and a plurality of metal-made terminals 312 are fixed to a terminal base 311 of the rear housing 302.
When the battery pack 330 is attached to the interior of the rear housing 302, the connector 332 is brought into contact with the plurality of terminals 312 on the power tool 301 side. As a result, a state in which electric power from the battery pack 330 can be supplied to the motor 304 is obtained. In the battery pack 330, for example, two lithium-ion cells of the 18650 size are housed; however, the size and the number of the housed secondary batteries are optional, and cells of the 14500 size may be used for downsizing. The housed batteries are not limited to secondary batteries, but also may be primary batteries such as dry-cell batteries.
In the space which is inside the rear housing 302 and is between the battery pack 330 and the turning shaft 310, a switch (main switch) 306, which controls supply/stoppage of electric power to the motor 304, and a forward/reverse switch 308 for switching the rotation direction of the motor 304 are housed. In the present embodiment, the switch 306 employs a so-called variable resistance switch in which the resistance value thereof is varied depending on the operation amount of a plunger 306a, and the rotation speed of the motor 304 is variable depending on the operation amount of the switch 306. The plunger 306a of the switch 306 is operated by a trigger part 307, and a part for connection to the plunger 306a is slid in the top-bottom (vertical) direction.
The part connected to the plunger 306a is configured to be movable in the top-bottom direction when the front side of the trigger part 307 is swung (turned) about the swinging shaft (swing supporting point) 313 by a predetermined angle. In the present embodiment, a swinging shaft 313 is provided in the front side of the trigger part 307; therefore, the operator who holds the rear housing 302 also serving as the grip part is capable of easily holding the trigger part 307, and the power tool 301 having the easy-to-use switch mechanism was achieved.
The forward/reverse switch 308 is provided in the space which is in the front side of the switch 306 and is between the switch 306 and the turning shaft 310. The forward/reverse switch 308 is a switch for switching the rotation direction of the motor 304 to a “forward rotation direction (tightening direction)” and a “reverse rotation direction (loosening direction)”. The forward/reverse switch 308 can be operated by sliding a lever part thereof in the left-right direction; wherein, a mechanical or electrical lock mechanism is preferred to be achieved by providing not only providing the lever member with two locations of a forward-rotation-direction position and a reverse-rotation-direction position, but also providing a lock position therebetween so that, at the lock position, the trigger part 307 is mechanically locked to be immobile or the motor 304 is configured to be not electrically turned on even when the trigger part 307 is pulled.
The cover 315 is disposed in the vicinity of the turning shaft 310 and in the side toward which the front housing 303 and the rear housing 302 are folded (the side in which a narrow angle is formed). In a way opposite to that of the power tool shown in
As is understood from
In the present embodiment, the turning shaft 310 of the turning mechanism of the housings, the turning shaft 316 of the cover 315, and the swinging shaft 313 of the trigger part 307 are disposed in parallel to each other so as to be extended in the left-right direction. The turning shaft 310 (the front-rear-direction position thereof is at an arrow A1), the turning shaft 316 (the front-rear-direction position thereof is at an arrow A2), and the swinging shaft 313 (the front-rear-direction position thereof is at an arrow A3) are sequentially disposed from the front to the rear. This means that the turning shaft 316 and the swinging shaft 313 are disposed in the rear of the turning shaft 310, in other words, are disposed inside the rear housing 302; therefore, the structure of the front housing 303 can be simplified, and the assembling performance thereof can be improved.
Furthermore, the front housing 303 is not required to house a switch mechanism between the motor 304 and the turning shaft 310 different from the conventional technique shown in
When using in the state of the gun type as shown in
In the present embodiment, the rotation speed of the motor 304 is varied depending on the pulled degree of the trigger part 307; therefore, a tightening operation can be effectively carried out while optionally adjusting the rotation speed. On the front side of the protruding part 302d, an oblique side part 302b, which is formed obliquely upward toward the front end part of the rear housing 302, is formed. When the rear housing 302 is turned, the oblique side part 302b abuts a rear end surface 303b of the front housing 303. Because of a reason that the oblique side part 302b has to be formed in this manner and a reason that the lead wires 309a and 309b have to be extended on the lower side of the turning shaft 310, the cover 315 is provided in the power tool 301 of the present embodiment; and, in the straight state, the cover 315 functions as a casing or part of the housing which covers the internal space for allowing extension of the lead wires 309a and 309b. In the folded state, the cover 315 is housed in housing space of the front housing 303. In order to ensure the housing space, a protruding part 303a, which is somewhat projecting downward, is formed on the lower side of the vicinity of the rear end of the front housing 303.
As described above, in the present embodiment, in the internal space of the rear housing 302, the two switches, i.e., the switch 306 and the forward/reverse switch 308 are disposed between a front end surface of the battery pack 330 and the turning shaft 310. Furthermore, the trigger part 307, which can adjust the speed of the motor 304 depending on the operation amount thereof, is provided immediately below the switch 306; therefore, a very easy-to-use power tool was achieved. Moreover, the configuration of the switch part can be comparatively simply formed, and the manufacturing cost of the power tool can be effectively reduced. In the present embodiment, the two switches, i.e., the switch 306 and the forward/reverse switch 308 are mutually different parts; however, a switch unit of a combination type integrating them for the power tool may be used, or a switch mechanism which carries out variable speed control of the motor 304 and a switch mechanism which switches the rotation direction of the motor 304 maybe achieved by providing a plurality of types of switch units, contact point units, and variable capacity units on a circuit board to which the switch 306 is fixed.
Next, a fourth embodiment of the present invention will be described with reference to
The power tool 351 utilizes electric power, which is supplied by the battery pack 330, to rotate the motor 354 serving as a drive source. The rotation of the motor 354 is subjected to speed reduction by the speed reducing mechanism 365 and subjects an output shaft 376 to rotary drive at a predetermined speed via the clutch mechanism 370. The speed reducing mechanism 365 is comprised of, for example, a three-level planetary-wheel speed-reducing mechanism (speed-changing gear case) meshed with a pinion gear of a rotation shaft of the motor 354. Moreover, the speed reducing mechanism 365 has a shift knob 368 for switching a speed switching ratio, and two-level speed change to a low speed and a high speed is enabled when the operator carries out a switching operation of the shift knob 368. A housing of the power tool 351 is comprised of the front housing 353 and the rear housing 302. The front housing 353 and the rear housing 2 are turnable about the turning shaft 310 by about 70 degrees only; and operations can be carried out in a so-called straight-type shape in which the front housing 353 and the rear housing 302 have the same axis to each other as shown in
The clutch mechanism 370, which is disposed on the tip side of the front housing 353, controls whether rotation torque, which is obtained at the output shaft of the speed reducing mechanism 365, is to be transmitted to the output shaft 376 or not in response to load. Therefore, when desired tightening torque (load torque) is set in advance by a dial 379 for torque adjustment and mode switching, the clutch mechanism 370 has a function that, when the rotative force of the output shaft of the speed reducing mechanism 365 reaches the set tightening torque, the output shaft thereof is caused to idle to shut off the transmission of rotation from the speed reducing mechanism 365 to the output shaft 376.
The clutch mechanism 370 is comprised of: a pin 372, which is a clutch nail; a clutch nail, which is formed on a front end surface of a ring gear 369 constituting the third-level planetary-gear speed-reducing mechanism; a coil spring 374, which presses the pin 372 toward the rear in the axial direction; and a pressing member 375, which is movable in the axial direction in the front side of the coil spring 374. The pressing member 375 is rotated in synchronization when the dial 379 is rotated. When the dial 379 is operated to be rotated, the pressing member 375 is moved in the axial direction. When the pressing member 375 is moved in the axial direction (front-rear direction), the strength of the biasing force of the pin 372 toward the rear can be adjusted, and the tightening torque (load torque) can be adjusted. In
Next, a fifth embodiment of the present invention will be explained by using
Next, a sixth embodiment of the present invention will be described with reference to
An unillustrated compressed spring 396b is disposed in the periphery of the plunger 396a. When the operator is not pulling the trigger part 397, the convex part 397a is caused to abut an inner wall of the protruding part 392d by the repulsive force of the compressed spring 396b. This abutting position is the position at which the motor is stopped. Also in the fourth embodiment, the speed of the motor 304 can be adjusted by the pulling amount of the trigger part 397, and the easy-to-use foldable-type power tool can be achieved. The cover 315 is axially supported to the rear housing 302 by the turning shaft 316. However, as is understood from
Next, a seventh embodiment will be described with reference to
The rear housing 402 is formed to have a cylindrical shape having an opening 402c in the rear end thereof and is manufactured by integral molding of a polymer resin product such as plastic. The front housing 403 and the rear housing 402 are coupled to each other by a turning shaft 410 and are turnable about the turning shaft 410 by about 70 degrees. The plane that turns is the plane including the front-rear and top-bottom directions viewed in
The motor 404 is a brushed DC motor used as a drive source for rotating an unillustrated tip tool and is housed in the rear side of the front housing 403. In the present embodiment, the battery pack 430 is used as an electric power source for driving the motor 404. A rotation shaft of the motor 404 is connected to a power transmission system for rotating the tip tool. In the present embodiment, the power transmission system is comprised of: a speed reducing mechanism 415, which uses planetary wheels; and a striking mechanism 420 having a hammer 422 and an anvil 425, and they are serially disposed to have the same axis with the motor 404. The speed reducing mechanism 415 has a sun gear attached to the rotation shaft of the motor 404, a plurality of planetary gears, and a fixed-type ring gear on the outer peripheral side of the planetary gears. In the speed reducing mechanism 415, a planetary carrier fixing a rotation shaft of the plurality of planetary gears is rotated. A widely used publicly-known striking mechanism (impact mechanism) can be used to constitute the striking mechanism 420. The striking mechanism 420 is comprised of: a spindle 421, which is connected to the planetary carrier; a hammer 422, which is movable in an axial direction; a spring 424, which biases the hammer 422; cam grooves; balls; etc.
The battery pack 430 has a substantially cylindrical chassis, which is attachable and detachable to/from internal space through the opening 402c of the end part of the rear housing 402, and the battery pack is an electric power source which is a so-called cassette type and easily replaceable. Unillustrated hooking parts are provided at two locations on the chassis of the battery pack 430, and, when they are engaged with recessed parts (not illustrated) formed on the inner wall of the rear housing 402, the battery pack 430 is retained. In order to detach the battery pack 430, the battery pack 430 is pulled from the opening 402c while pressing latch parts 431 provided at two locations on the left and the right. The shape of the rear end part of the battery pack 430 is formed so as to cover the opening 402c of the rear housing 402, and the rear surface of the battery pack 430 forms part of an outer edge part of the rear housing 402. A connector 432 is provided at a substantially rectangular corner part of the front end of the battery pack 430, and a plurality of metal-made connectors 432 are fixed to a base 411 of the rear housing 402. When the battery pack 430 is attached to the interior of the rear housing 402, the connector 432 is brought into contact with the plurality of terminals 412 on the power tool 401 side; as a result, a state in which electric power from the battery pack 430 can be supplied to the motor 404 is obtained.
In the space which is in the rear housing 402 and is between the battery pack 430 and the turning shaft 410, a switch (main switch) 406, which controls supply/stoppage of electric power to the motor 404, and a forward/reverse switch 408 for switching the rotation direction of the motor 404 are housed. In the present embodiment, the switch 406 is a so-called variable resistance switch in which the resistance value thereof is varied depending on the operation amount of a plunger 406a, and the rotation speed of the motor 404 is varied depending on the operation amount of the switch 406. The plunger 406a of the switch 406 is operated by a trigger part 407 of a so-called paddle type, having a part thereof connected to the plunger 406a is slid in the top-bottom direction.
A trigger part 407 has a predetermined length in the front-rear direction, and the part thereof in contact with the plunger 406a is slidable in the top-bottom direction when the rear side of the trigger part is swung (turned) about a swinging shaft (turn supporting point) 413 by a predetermined angle. In the present embodiment, the trigger part 407 is comparatively large in the front-rear direction; therefore, the power tool 401 having an easy-to-use switch mechanism which can be easily gripped by the operator who grips the rear housing 402, which also serves as a grip part is achieved. A tip part of the trigger part 407 can be easily held by the operator and is provided with a protruding part 407a which is projecting downward so that the tip part of the trigger part 407 can be determined by a touch sensation. As the pull load (=the compression load of the plunger 406a) of the trigger part 407, initial load P may be set as shown by the expressions below, where the total weight of the rear housing 402 side (including the battery pack) is M2, and the weight of the front housing 403 side is M1.
If M2>M1,
P≧(M1+M2)/2 (1)
If M2≦M1,
P≧(M1+M2) (2)
When the pull load of the trigger part 407 is set in this manner, even if the own weight of the power tool 401 is applied to the trigger part 407 for some reason such as a situation in which the power tool 401 is placed on the floor, the switch 406 can be effectively prevented from being unintentionally turned on since the pull load of the trigger part 407 is larger than the own weight of the power tool 401.
The forward/reverse switch 408 is provided in the space which is on the front side of the switch 406 and between the switch 406 and the turning shaft 410. The forward/reverse switch 408 is a switch for switching the rotation direction of the motor 404 to a “forward rotation direction (tightening direction)” and a “reverse rotation direction (loosening direction)”. The forward/reverse switch 408 can be operated by sliding an operation lever 409 in the left-right direction; however, a lock mechanism is preferred to be achieved such that the operation lever 409 is provided not only with two locations, i.e., a forward-rotation-direction position and a reverse-rotation-direction position but also with a lock position therebetween so that, when the operation lever 409 is fixed at the position, the trigger part 407 is mechanically locked to disable pulling or the motor 404 is not electrically turned on.
The swinging shaft 413 is disposed in the overlapped part. Therefore, even when the axial-direction length of the space between the battery pack 430 and the turning shaft 410 is limited, the length of the trigger part 7 can be configured to be sufficiently long, and the axial-direction length of the rear housing 402 is effectively prevented from being increased depending on the shape of the trigger part 407. In the front housing 403, the switch mechanism is not required to be housed between the motor 404 and the turning shaft 410 different from the conventional technique described in Patent Document 1. Therefore, the axial-direction length of the front-side housing 403 can be made shorter by the length of the switch mechanism. Herein, the outer diameter DB of the battery pack 430 is 18 mm, and the diameter DH of the motor 404 is 29 mm, where the outer diameter DB of the battery pack 430 is made sufficiently small with respect to the motor. Therefore, sufficient space can be ensured at the lower side of the battery pack 430 side, the grip part can be prevented from becoming thick even when the trigger part 407 of the paddle type is provided, and therefore the easy-to-hold power tool can be achieved. The motor and the turning mechanism are disposed on the same axis inside the front housing, and a rear end of the motor is adjacent to the turning mechanism.
The axial direction of the swinging shaft 413 is disposed so as to be in the left-right direction of the rear housing 402. This is a perpendicular direction when viewed from the turning plane. On the inner side of the vicinity of the front end of the trigger part 407, a convex part 407b, which abuts the inner side of a stopper wall 402b of the rear housing 402, is formed. Part of the switch-side surface of the trigger part 407 abuts the plunger 406a. The plunger 406a is biased by an unillustrated compression spring in the direction in which the plunger 406a projects from the switch 406. When the operator stops holding the trigger part 407, the convex part 407b is returned by the effect of the spring to the position abutting the stopper wall 402b, i.e., to the position at which the motor 404 is turned off.
In the present embodiment, in the internal space of the rear housing 402, the two switches, i.e., the switch 406 and the forward/reverse switch 408 are disposed between the front end surface of the battery pack 430 and the turning shaft 410. In the present embodiment, these two switches are mutually different parts; however, a switch unit for a power tool of a combination type in which they are integrated may be used. A front upper end part of the rear housing 402 serves as a protruding part 402d, which abuts a step part 403a of a rear part of the front housing 403 and serves as a stopper in the straight state.
When the plunger 408a is moved in the left-right direction, the forward/reverse switch 408 switches the rotation direction of the motor 404 to forward rotation or reverse rotation. The plunger 408a is linked with the movement of the operation lever 409 and moved to the left-right by a working part 414 fixed to the operation lever 409. When the operation lever 409 is disposed in this manner, in a situation in which the power tool 401 particularly having the shape of the straight type is placed and rolled on the floor or the like, the operation lever 409 can be effectively prevented from being moved by the own weight of the power tool 401. In the seventh embodiment of
Next, with reference to
As described above, in the three states of
Next, an eighth embodiment of the present invention will be described with reference to
The power tool 451 utilizes the electric power, which is supplied by the battery pack 430, to rotate the motor 454 serving as a drive source. The rotation of the motor 454 is subjected to speed reduction by the speed reducing mechanism 465 and subjects an output shaft 476 to rotary drive at a predetermined speed via the clutch mechanism 470. The speed reducing mechanism 465 is comprised of, for example, a three-level planetary-wheel speed-reducing mechanism (speed-changing gear case) meshed with a pinion gear of a rotation shaft of the motor 454. Moreover, the speed reducing mechanism 465 has a shift knob 468 for switching a speed switching ratio, and two-level speed change to a low speed and a high speed is enabled when the operator carries out a switching operation of the shift knob 468. A housing of the power tool 451 is comprised of the front housing 453 and the rear housing 402. The front housing 453 and the rear housing 402 are turnable about the turning shaft 410 by about 70 degrees only; and operations can be carried out in a so-called straight-type shape in which the front housing 453 and the rear housing 402 have the same axis with each other as shown in
The clutch mechanism 470, which is disposed on the tip side of the front housing 453, controls whether rotation torque, which is obtained at the output shaft of the speed reducing mechanism 465, is to be transmitted to the output shaft 476 or not in response to load. In this manner, when desired tightening torque (load torque) is set in advance by a dial 479 for torque adjustment and mode switching, the clutch mechanism 470 has a function that, when the rotative force of the output shaft of the speed reducing mechanism 465 reaches the set tightening torque, the output shaft is caused to idle to shut off the transmission of rotation from the speed reducing mechanism 465 to the output shaft 476.
The clutch mechanism 470 is comprised of: a pin 472, which is a clutch nail; a clutch nail, which is formed on a front end surface of a ring gear 469 constituting the third-level planetary-gear speed-reducing mechanism; a coil spring 474, which presses the pin 472 toward the rear in the axial direction; and a pressing member 475, which is movable in the axial direction on the front side of the coil spring 474. The pressing member 475 is configured so as to be rotated in synchronization when the dial 479 is rotated. When the dial 479 is operated to be rotated, the pressing member 475 is moved in the axial direction. When the pressing member 475 is moved in the axial direction (front-rear direction), the strength of the biasing force of the pin 472 toward the rear can be adjusted, and the tightening torque (load torque) can be adjusted.
In
Next, a ninth embodiment of the present invention will be described with reference to
Next, a tenth embodiment of the present invention will be described with reference to
At the front-side part of the rear housing 452 in which the trigger part 457 is provided, a protruding part 452a protruding downward than the trigger part 457 is formed and plays a role of a stopper so that, when the operator places the power tool 451 in the straight state on the floor, the trigger part 457 is not unintentionally caused to be in a pulled state. An unillustrated compressed spring is disposed in the periphery of the plunger 406a. When the operator is not pulling the trigger part 457, a convex part 457b of the trigger part 457 is caused to abut the inner wall of the protruding part 452a by the repulsive force of the compression spring. This abutting position is the position at which the motor is stopped.
Next, an eleventh embodiment of the present invention will be described with reference to
The front-rear-direction length LT2 of the trigger part 407 of the eleventh embodiment is short compared with LT of the seventh embodiment and has a size suitable for the operator to carry out a pulling operation with the forefinger and the middle finger. Moreover, the trigger part 407 is configured so as to be slightly overlapped in the axial direction with the length LB in which the battery pack is housed; therefore, the trigger part 407, which is somewhat long, can be achieved without increasing the total length of the rear housing 402. In the front-side part of the rear housing 402 in which the trigger part 407 is provided, a protruding part 402a, which protrudes more downward than the trigger part 407, is formed. When the operator places the power tool 401 in the straight shape on the floor, the protruding part plays a role as a stopper so that the trigger part 407 is not unintentionally caused to be in a pulled state. An unillustrated compression spring is disposed in the periphery of the plunger 406a. When the operator is not pulling the trigger part 407, the convex part 407b of the trigger part 407 is caused to abut the inner wall of the protruding part 402a by the repulsive force of the compression spring. This abutting position is the position at which the motor is stopped.
Next, a twelfth embodiment of the present invention will be described with reference to
Hereinabove, the present invention has been explained based on the plurality of embodiments. In any of the cases, the disposing methods of the switches of the power tools thereof can simultaneously achieve downsizing in addition to improvement in the switch operability, and the operability can be genuinely improved.
Hereinabove, the present invention has been explained based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the range not departing from the gist thereof. For example, the above-described embodiments are formed by using the attachable/detachable battery pack 430; however, the invention may be applied not only to the attachable/detachable configuration, but also to a power tool directly incorporating a battery cell in the rear housing. Moreover, the power transmission system housed in the front housing of the foldable-type power tool can be used not only to a product comprised of the impact mechanism or the clutch mechanism, but can be similarly used also to a foldable-type power tool using another optional mechanism(s). Furthermore, the type of the motor housed in the front housing is not limited only to a brushed motor, but may be configured to use a brushless DC motor.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-158175 | Jul 2012 | JP | national |
| 2012-213267 | Sep 2012 | JP | national |
| 2012-256999 | Nov 2012 | JP | national |
