Source: https://patents.google.com/patent/US7743514B2/en
Timestamp: 2020-01-27 03:08:39
Document Index: 497036765

Matched Legal Cases: ['art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145', 'art 145']

US7743514B2 - Reciprocating power tool - Google Patents
Reciprocating power tool Download PDF
US7743514B2
US7743514B2 US12/318,126 US31812608A US7743514B2 US 7743514 B2 US7743514 B2 US 7743514B2 US 31812608 A US31812608 A US 31812608A US 7743514 B2 US7743514 B2 US 7743514B2
US12/318,126
US20090113728A1 (en
Sadaharu Oki
2004-12-02 Priority to JP2004350015A priority Critical patent/JP4573637B2/en
2004-12-02 Priority to JP2004-350015 priority
2005-11-30 Priority to US11/289,547 priority patent/US7526868B2/en
2008-12-22 Application filed by Makita Corp filed Critical Makita Corp
2008-12-22 Priority to US12/318,126 priority patent/US7743514B2/en
2009-05-07 Publication of US20090113728A1 publication Critical patent/US20090113728A1/en
2010-06-29 Publication of US7743514B2 publication Critical patent/US7743514B2/en
Japanese non-examined laid-open Patent Publication No. 2001-9632 (hereinafter referred to as “D1”) discloses an electric reciprocating saw as an example of a reciprocating power tool. The known reciprocating saw includes a motion converting mechanism for causing a slider to reciprocate in the longitudinal direction. A counter weight is provided in the motion converting mechanism. When the slider reciprocates, the counter weight reciprocates in a direction opposite to the reciprocating direction of the slider, with a 180° phase shift with respect to the slider. As a result, vibration of the reciprocating saw caused by the reciprocating movement of the slider can be reduced.
Further, Japanese non-examined laid-open Patent Publication No. 06-79701 (hereinafter referred to as “D2”) discloses an electric reciprocating saw having a first motion converting mechanism for converting the rotating output of a motor into reciprocating linear motion in the longitudinal direction of the slider and a second motion converting mechanism for converting the rotating output of the motor into swinging motion in the vertical direction of the slider. In the reciprocating saw having such a construction, the tool bit or the blade supported by the slider not only linearly reciprocates in the longitudinal direction, but swings in the vertical direction, whereby the cutting efficiency can be increased.
The above-described problem can be solved by the features of claimed invention. According to the invention, a representative reciprocating power tool is provided to comprise a body, a tool bit disposed in the tip end region of the body, an actuating mechanism disposed within the body to cause the tool bit to linearly reciprocate, a handgrip disposed on the rear end of the body on the side opposite to the tool bit. The “reciprocating power tool” according to the invention may include various power tools such as a reciprocating saw and a jig saw, to be used to cut a workpiece of various materials such as wood and metal. The “tool bit” typically comprises a blade which is formed of a steel sheet and has teeth continuously formed on the edge of the steel sheet.
According to the invention, an elastic element is disposed between the handgrip and the body and serves to absorb vibration transmitted from the body to the handgrip by elastically receiving the relative rotation of the handgrip and the body. The “elastic element” comprises a rubber or a spring. The manner in which the “elastic element is disposed” suitably includes both the manner in which the elastic element is disposed apart from the pivot and the manner in which the elastic element is disposed on the axis of the pivot. The elastic element disposed between the handgrip and the body absorbs and reduces vibration caused in the body and transmitted to the handgrip, by elastic deformation of the elastic element. Such vibration reduction by using the elastic element is more effective for weight reduction of the reciprocating power tool, compared with the known art that uses a counter weight.
FIG. 1 is a sectional view showing an entire reciprocating saw having a vibration-proof handgrip according to an embodiment of the invention.
A representative embodiment of the present invention will now be described with reference to the drawings. As shown in FIG. 1, a reciprocating saw 101 as a representative embodiment of a reciprocating power tool according to the invention comprises a body 103, a slider 107, a blade 111 and a handgrip 105. The slider 107 projects from the body 103 and the blade 111 is detachably mounted to a chuck 109 on the end of the slider 107 and cuts a workpiece (not particularly shown). The blade 111 is a feature that corresponds to the “tool bit” according to the invention. The body 103 includes a motor housing 103 a and a gear housing 103 b connected to the front end of the motor housing 103 a In the present embodiment, for the sake of convenience of explanation, the side of the blade 111 is taken as the front side and the side of the handgrip 105 as the rear side in the following description.
The motor housing 103 a of the body 103 houses a driving motor 113. The driving motor 113 is driven when the user depresses a trigger switch 115. The blade 111 then reciprocates in the longitudinal direction together with the slider 107 and the chuck 109 and can cut a workpiece. The slider 107, the chuck 109 and the blade 111 form a moving part. The slider 107 is supported via a bearing 108 in the gear housing 103 b such that the slider 107 can reciprocate in its longitudinal direction. The slider 107 is connected to a motor shaft 117 via a motion converting mechanism 121 disposed within the gear housing 103 b. The motion converting mechanism 121 is a feature that corresponds to the “actuating mechanism” according to the invention.
The construction of the handgrip 105 and the construction for mounting the handgrip 105 to the body 103 will now be explained with reference to FIGS. 1 to 3. Vibration is caused in the body 103 during operation of cutting a workpiece with the reciprocating saw 101. According to the representative embodiment, in order to reduce transmission of this vibration to the handgrip 105, the handgrip 105 is constructed as follows. The handgrip 105 is a D-type handgrip which is generally D-shaped in side view. The handgrip 105 is hollow and generally rectangular in section. An opening 141 is formed in the front upper region of the handgrip 105 and opens to the front. In order to mount the handgrip 105 to the motor housing 103 a, the opening 141 is fitted on the rear end of the body 103 or a grip mounting portion 143 formed in the rear end portion of the motor housing 103 a.
The handgrip 105 has a two-part structure which is divided into halves along a vertical plane parallel to the axis of the slider 107. Specifically, the handgrip 105 includes right and left halves 105 a, 105 b (see FIGS. 2 and 3). The right and left halves 105 a, 105 b are butted against each other from the sides in such a manner that the region of the opening 141 covers the grip mounting portion 143. In this state, the halves 105 a, 105 b are joined by clamping screws 144 (see FIG. 1) at several points on the edge portions of the halves 105 a, 105 b. Thus, the handgrip 105 is fixedly mounted on the grip mounting portion 143. The handgrip 105 can be detached from the grip mounting portion 143 by unscrewing the clamping screws 144 so as to disjoin the halves 105 a, 105 b from the grip mounting portion 143. Specifically, the handgrip 105 is constructed to be detachably mounted to the body 103. Further, as shown in FIG. 1, an engaging portion 142 is formed on the engagement surfaces between the opening 141 and the grip mounting portion 143. The respective engaging portions 142 have projections and depressions and engage with each other. By the engagement of the engaging portions 142, the handgrip 105 is prevented from falling off rearward from the body 103.
Further, the handgrip 105 is partitioned into two forward and rearward parts. The forward part comprises a fixed part 145 a mounted to the motor housing 103 a, and the rearward part comprises a moving grip part 145 b that a user grips. The fixed part 145 a is mounted to the motor housing 103 a in such a manner as mentioned in the preceding paragraph. One end (lower end) of the moving grip part 145 b is rotatably connected to one end (lower end) of the fixed part 145 a via a pivot 147. The other end (upper end) of the moving grip part 145 b is elastically connected to the other end (upper end) of the fixed part 145 a via a compression coil spring 149. The compression coil spring 149 is a feature that corresponds to the “elastic element” in the present invention. With the above-mentioned construction, the moving grip part 145 b and the body 103 can rotate vertically or in a direction crossing the direction of the reciprocating movement of the blade 111 about the pivot 147 with respect to each other. Thus, the vibration-proof handgrip 105 is formed with a construction in which the moving grip part 145 b is rotatably connected at its lower end to the fixed part 145 a via the pivot 147 and connected at its upper end to the fixed part 145 a via the compression coil spring 149.
When the slider 107 moves from the top dead center to the bottom dead center or when the blade 111 retracts to be drawn leftward as viewed in FIG. 1 to cut the workpiece, the angle of inclination of the blade 111 defined by the angle between the horizontal axis and the axis of the slider 107 gradually increases. In other words, the tip end of the blade 111 is oriented upward. By such increase in the blade inclination, the number of teeth of the blade 111 which touch the workpiece during cutting operation is reduced compared with the case in which the blade 111 is moved linearly. Therefore, the teeth of the blade 111 can readily dig into the workpiece, so that the cutting efficiency can be improved. On the other hand, when the slider 107 moves from the bottom dead center to the top dead center (the blade 111 is pushed), the angle of inclination of the blade 111 gradually decreases. FIG. 4 shows the blade 111 inclined at an angle of θ1 (for example, 1°) when the slider 107 is in the bottom dead center. FIG. 5 shows the blade 111 inclined at an angle of θ2 (for example, −5°) when the slider 107 is in the top dead center. Thus, according to the embodiment, when the blade 111 linearly reciprocates, the blade 111 is caused to vertically swing together with the body 103, so that the angle of inclination of the blade 111 changes. As a result, the cutting efficiency can be improved. The angle of inclination of the blade 111 tends to vary in a greater degree as the load during cutting operation increases.
a handgrip disposed on a rear end of the body on the side opposite to the tool bit, wherein the handgrip and the body are coupled to each other such that the handgrip and the body can rotate with respect to each other via a fixed axis pivot about a rotational axis extending in a direction perpendicular to a direction of reciprocating linear motion of the tool bit and the tool bit swings together with the body with respect to the handgrip held by a user of the power tool, at the same time as when the tool bit linearly reciprocates with respect to the body via the motor;
an elastic element disposed between the handgrip and the body, wherein the elastic element absorbs vibration transmitted from the body to the handgrip by elastically receiving the relative rotation of the handgrip and the body; and
a dynamic vibration reducer disposed in the handgrip, the dynamic vibration reducer reducing the vibration transmitted from the body to the handgrip during cutting operation, the dynamic vibration reducer further being contained in the handgrip in line with the elastic element and closer to the rear end of the reciprocating power tool than the elastic element, the dynamic vibration reducer and the elastic element being positioned substantially along a rotation direction of the handgrip and the body and the dynamic vibration reducer further including at least a weight and a spring disposed on each side of the weight.
2. The reciprocating power tool as defined in claim 1, wherein the dynamic vibration reducer comprises a single dynamic vibration reducer.
a switch to turn on and off the motor, wherein the dynamic vibration reducer is provided above the switch.
6. The reciprocating power tool as defined in claim 1, wherein the dynamic vibration reducer has a guide rod and the weight surrounds the guide rod.
12. The reciprocating power tool as defined in claim 11, wherein, when the tool bit linearly moves in a direction to cut a workpiece, the angle of inclination of the tool bit gradually increases.
US12/318,126 2004-12-02 2008-12-22 Reciprocating power tool Active US7743514B2 (en)
JP2004350015A JP4573637B2 (en) 2004-12-02 2004-12-02 Reciprocating work tool
JP2004-350015 2004-12-02
US11/289,547 US7526868B2 (en) 2004-12-02 2005-11-30 Power tool with vibration reduction
US12/318,126 US7743514B2 (en) 2004-12-02 2008-12-22 Reciprocating power tool
US11/289,547 Continuation US7526868B2 (en) 2004-12-02 2005-11-30 Power tool with vibration reduction
US20090113728A1 US20090113728A1 (en) 2009-05-07
US7743514B2 true US7743514B2 (en) 2010-06-29
ID=35610083
US11/289,547 Active US7526868B2 (en) 2004-12-02 2005-11-30 Power tool with vibration reduction
US12/318,126 Active US7743514B2 (en) 2004-12-02 2008-12-22 Reciprocating power tool
US (2) US7526868B2 (en)
EP (2) EP1666182B9 (en)
JP (1) JP4573637B2 (en)
DE (1) DE602005022035D1 (en)
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2004-12-02 JP JP2004350015A patent/JP4573637B2/en active Active
2005-11-29 EP EP20050026037 patent/EP1666182B9/en active Active
2005-11-29 EP EP09006843.8A patent/EP2090393B1/en active Active
2005-11-29 DE DE200560022035 patent/DE602005022035D1/en active Active
2005-11-30 US US11/289,547 patent/US7526868B2/en active Active
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US7526868B2 (en) 2009-05-05
EP2090393A3 (en) 2010-11-03
EP1666182B1 (en) 2010-06-30
US20060117581A1 (en) 2006-06-08
EP2090393B1 (en) 2013-08-21
EP2090393A2 (en) 2009-08-19
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US20090113728A1 (en) 2009-05-07
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