Source: http://www.google.com/patents/USRE40643?ie=ISO-8859-1
Timestamp: 2015-06-02 06:31:20
Document Index: 717502060

Matched Legal Cases: ['art 2', 'art 4', 'arts 2', 'arts 2', 'arts 2', 'arts 2']

Patent USRE40643 - Rotary hammer - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA rotary hammer includes a spindle 18 which can be rotatably driven by an intermediate shaft 24 by way of a drive device. A tool holder 16 is arranged for rotation with the spindle 18, and for releasably holding a bit or tool for selective rotation and/or reciprocation. A pneumatic hammering arrangement...http://www.google.com/patents/USRE40643?utm_source=gb-gplus-sharePatent USRE40643 - Rotary hammerAdvanced Patent SearchPublication numberUSRE40643 E1Publication typeGrantApplication numberUS 11/318,391Publication dateFeb 24, 2009Filing dateDec 23, 2005Priority dateApr 7, 2000Fee statusPaidAlso published asDE60137167D1, EP1157788A2, EP1157788A3, EP1157788B1, US6666284, US20020134563Publication number11318391, 318391, US RE40643 E1, US RE40643E1, US-E1-RE40643, USRE40643 E1, USRE40643E1InventorsMichael StirmOriginal AssigneeBlack & Decker Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (19), Referenced by (2), Classifications (10), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetRotary hammer
US RE40643 E1Abstract
an intermediate shaft (24) which is rotatably driven by a motor of the rotary hammer when power is supplied to the motor; a spindle (18) which can be driven in rotation about its axis by the intermediate shaft 24 through a spindle drive arrangement (62,64); a tool holder (16) arranged for rotation with the spindle (18) for releasably holding a bit or a tool such that the bit or tool can reciprocate; a pneumatic hammering arrangement (20,21,22) located within the spindle (18) which can repeatedly impact the bit or tool held within the tool holder (16); said pneumatic hammering arrangement comprising a piston (20) which can be reciprocally driven by a hammer drive arrangement (34,36,38,39,40,42) which can translate rotary drive from the intermediate shaft (24) to a reciprocating drive to the piston (20); and a mode change mechanism for changing the operation of the rotary hammer to operate in any of three modes, a rotary drive only mode, a hammer only mode or a rotary hammer mode; said mode change mechanism comprising: a single actuator (8) switchable by a user of the rotary hammer amongst the three modes of operation; a spindle driving member (56) rotatable on the intermediate shaft (24) for driving the spindle drive arrangement (62,64); a hammer driving sleeve (34) rotatable on the intermediate shaft (24) for driving the hammer drive arrangement (34,36,38,39,40,42); and a mode change sleeve (52) which is permanently driven by the intermediate shaft ( 24 ) and shiftable along the intermediate shaft (24) to change the operation of the rotary hammer to operate in any of the three modes; where, upon the switching of the actuator (8) by a user, shifts the mode change sleeve (52) along the intermediate shaft (24) amongst the three modes positions, such that in a first rotary drive only position the mode change sleeve (52) transmits rotary drive to the spindle driving member (56) to transmit rotary drive to the spindle drive arrangement (62,64), in a second hammer only position the mode change sleeve (52) transmits rotary drive to the hammer driving sleeve (34) to transmit rotary drive to the hammer drive arrangement (34,36,38,39,40,42), and in a third rotary hammer position the mode change sleeve (52) transmits rotary drive to the spindle driving member (56) and to the hammer driving sleeve (34) to transmit rotary drive to the spindle drive arrangement (62,64) and to the hammer drive arrangement (34,36,38,39,40,42). 2. The rotary hammer according to claim 1, which further comprises:
the spindle drive member (56) comprises: a driving member (60); a driven member (62), which forms a part of the spindle drive arrangement (62,64); and wherein the driving member (60) is in permanent engagement with the drive member (62). 19. The rotary hammer according to claim 1, wherein the hammer drive arrangement is a wobble plate arrangement (36,38,39,40).
a releasable detent arrangement (90,92,94) for releasably latching the actuator (8) in a mode switch position. 21. The rotary hammer according to claim 1, wherein the mode change sleeve is a single sleeve. 22. A rotary hammer comprising:
a housing; a tool holder coupled to the housing and configured to releasably hold a tool; a spindle configured to rotate about a first longitudinal axis of the spindle to cause drilling motion of a tool held within the tool holder; a piston that reciprocates within the spindle along the first longitudinal axis to cause hammering motion of a tool held within the tool holder; a motor at least partially disposed in the housing; an intermediate shaft configured to be rotated about a second longitudinal axis by the motor when power is supplied to the motor; a spindle drive mechanism coupled to at least one of the intermediate shaft and the spindle to selectively transmit rotary motion of the intermediate shaft to rotary motion of the spindle; a piston drive mechanism coupled to at least one of the intermediate shaft and the piston to selectively transmit rotary motion of the intermediate shaft to reciprocal motion of the piston; a mode change mechanism configured to select among a drilling mode, a hammering and drilling mode, and a hammering mode, the mode change mechanism including a front sleeve portion and a rear sleeve portion each shiftable along the intermediate shaft and permanently driven by the intermediate shaft to change the operation of the rotary hammer to operate in any of the three modes, wherein the front sleeve portion is moveable along the second longitudinal axis to selectively couple the spindle drive mechanism to the intermediate shaft when in the drilling mode and the hammering and drilling mode to transmit rotary movement of the intermediate shaft to rotary movement of the spindle and to selectively decouple the spindle drive mechanism from the intermediate shaft when in the hammering mode so that rotation of the intermediate shaft does not cause rotation of the spindle, and wherein the rear sleeve portion is moveable along the second longitudinal axis to selectively couple the piston drive mechanism to the intermediate shaft when in the hammering and drilling mode and the hammering mode to transmit rotary movement of the intermediate shaft to reciprocating movement of the piston and to selectively decouple the piston drive mechanism from the intermediate shaft when in the drilling mode so that rotation of the intermediate shaft does not cause reciprocating movement of the piston; an actuator switch moveable among three positions corresponding to the drilling mode, the hammering and drilling mode, and the hammering mode; and a linkage that links the actuator switch to the mode change mechanism to effectuate the movement of the front and rear sleeve portions upon movement of the actuator switch. 23. The rotary hammer according to claim 22, wherein the front sleeve portion comprises a projection that can be selectively engaged with a recess on the spindle driving member when the mode change mechanism is in the drilling mode and the drilling and hammering mode. 24. The rotary hammer according to claim 22, wherein the rear sleeve portion comprises a projection that can be selectively engaged with a recess on the hammer driving member when the mode change mechanism is in the hammering mode and the drilling and hammering mode. 25. The rotary hammer according to claim 24, wherein the front sleeve portion comprises a projection that can be selectively engaged with a recess on the spindle driving member when the mode change mechanism is in the drilling mode and the drilling and hammering mode. 26. The rotary hammer according to claim 22, wherein the linkage comprises a bar that extends substantially parallel to the second longitudinal axis and at least one arm that extends laterally from the bar, the at least one arm being coupled to the mode change mechanism such that shifting of the bar along the second longitudinal axis moves the mode change mechanism among the drilling mode, the drilling and hammering mode, and the hammering mode. 27. The rotary hammer according to claim 22, wherein the actuator switch comprises a rotatable knob mounted on the housing and an eccentric pin coupled to the rotatable knob, wherein when the rotatable knob is rotated the eccentric pin is rotated and slideably engages with the linkage in order to shift the mode change mechanism among the drilling mode, the drilling and hammering mode, and the hammering mode. 28. The rotary hammer according to claim 22, further comprising a spring that biases the mode change mechanism toward one of the drilling mode, the drilling and hammering mode, and the hammer mode. 29. The rotary hammer according to claim 28, wherein the spring biases the front sleeve portion of the mode change mechanism to couple the intermediate shaft to the spindle drive mechanism. 30. The rotary hammer according to claim 28, wherein the spring biases the rear sleeve portion of the mode change mechanism to couple the intermediate shaft to the piston drive mechanism. 31. The rotary hammer according to claim 22, further comprising a spindle lock member to lock the spindle against rotation when the rotary hammer is in the hammering mode. 32. The rotary hammer according to claim 31, wherein the spindle lock member comprises a set of teeth that are fixed against rotation and that are moveable substantially parallel to the second longitudinal axis with the linkage to bring the set of teeth into engagement with the spindle drive mechanism. 33. The rotary hammer according to claim 22, further comprising a ram that is reciprocally driven by the piston through an air cushion, and an anvil that is repeatedly impacted by the ram and that, in turn, impacts the tool held in the tool holder. 34. The rotary hammer according to claim 22, wherein the intermediate shaft is substantially parallel to the spindle. 35. The rotary hammer according to claim 22, wherein the spindle drive mechanism comprises a first splined ring gear that is permanently fixed to the spindle and a second splined ring gear that engages the first splined ring gear, wherein the front sleeve portion of the mode change mechanism causes the second splined ring gear to rotate with the intermediate shaft. 36. The rotary hammer according to claim 22, wherein the piston drive mechanism comprises a wobble drive mechanism that converts rotary motion of the intermediate shaft to reciprocal motion of the piston. 37. The rotary hammer according to claim 22, wherein the actuator includes a releasable detent arrangement that releasably latches the actuator in at least one of the three positions. 38. The rotary hammer according to claim 22, wherein front sleeve portion and the rear sleeve portion are disposed on a single mode change sleeve. Description
CROSS-REFERENCE TO RELATED APPLICATION This application is a Reissue of U.S. Pat. No. 6,666,284 B2, issued Dec. 23, 2003, which claims priority to Great Britain application Serial No. 0008465, filed Apr. 17, 2000. BACKGROUND OF THE INVENTION
Conventional rotary hammers of this type typically include a spindle mounted for rotation within a housing of the hammer which can be driven by a rotary drive arrangement, selectively engageable and disengageable with a pinion driven by a motor of the hammer. The spindle rotatably drives a tool holder of the hammer which in turn rotatably drives a tool or bit releasably secured within the hammer. A piston is generally slideably located within the spindle and is reciprocally driven by a hammer drive mechanism which translates the rotary drive of a hammer motor to a reciprocating drive of the piston. A ram, also slideably located within the spindle, forward of the piston, follows the reciprocation of the piston due to successive reversing pressures in an air cushion within the spindle between the piston and the ram. The ram repeatedly impacts an anvil slideably located within the spindle forward of the ram which transfers the forward impacts from the ram to the tool or bit, for limited reciprocation within the tool holder at the front of the hammer. The mode change mechanisms for such hammers can selectively engage and disengage the rotary drive to the spindle and the reciprocating drive to the piston.
In order to insure transmission of rotary drive between the parts, which may not initially be in meshing alignment when the hammer is first switched to one of the three modes of operation, a biasing arrangement is located between the actuator and the mode change sleeve in order to bias the sleeve towards a position on the intermediate shaft which corresponds to the position to which the actuator is switched. When the hammer includes a mode change member having a mode change arm as described above, it is preferred that the biasing arrangement includes a first spring means located between a forward end of the mode change sleeve and a forward facing part of the mode change arm and a second spring means located between a rearward end of the mode change sleeve and a rearward facing part of the mode change arm.
It is preferred that the spindle drive member include a driving member, preferably a gear, which is in permanent engagement with the spindle drive engagement, which preferably includes a gear.
Referring to FIGS. 1, 2a, 2b and 2c, a first embodiment of a rotary hammer includes a forward housing part 2 and a central housing part 4, which are held together by threaded fasteners (not shown) to form a housing for a hammer spindle, a spindle drive arrangement, a hammer drive arrangement and a mode change mechanism. A resilient housing seal 6 fits between the housing parts 2 and 4 in a complementary recess provided in co-operating end surfaces of the housing parts to form a seal between the housing parts. The housing parts 2 and 4 are each formed with semi-circular recesses 2a and 4a, respectively, which co-operate to form a circular recess, lined with a ring section 6a of the housing seal 6, within which a mode change knob 8 is mounted for rotation about a mode change axis 12. The mode change knob 8 has an axle with an enlarged portion 10 which is captured within the hammer housing when the housing parts 2 and 4 are assembled together. In this manner, the mode change knob 8 is secured to the hammer housing. An eccentric pin 14 is formed with and extends from an end of the mode change axle for slideably moving a mode change member 68, as described below.
The hammer drive arrangement includes a hammer drive sleeve 34 which is rotatably mounted on the intermediate 24 and which has a wobble plate track 36 formed around the sleeve at an angle to the axis of the intermediate shaft. A wobble plate ring 38, having an extending pin 40, is mounted for rotation around the wobble plate track 36 by way of ball bearings 39 in a conventional manner. The end of the wobble pin 40, remote from the wobble plate ring 38, is mounted through an aperture in a trunnion 42 which is pivotally mounted to the rear end of the hollow piston 20 by way of two arms 44 having aligned apertures formed therethrough. Thus, when the hammer drive sleeve 34 is rotatably drive about the intermediate shaft 24, a wobble plate drive (which is formed by the wobble plate track 36, the wobble plate ring 38, the ball bearings 39, the wobble pin 40, the trunnion 42 and the arms 44) reciprocally drives the hollow piston 20 in a conventional manner. The hammer drive sleeve 34 has a set of driven splines 48 formed on a forward end of the sleeve. The driven splines 48 are selectively engageable with the driving gear 50 by way of the mode change mechanism described below. When the intermediate shaft 24 is rotatably driven by the motor pinion, and the mode change mechanism engages the driving splines 48 of the hammer drive sleeve 34, (1) the driving gear 50 rotatably drives the hammer drive sleeve, (2) the piston 20 is reciprocally driven by the wobble plate drive, and (3) the tool or bit mounted in the tool holder 16 is repeatedly impacted by the anvil 22 by way of the action of the ram 21.
The spindle drive member includes a spindle drive sleeve 56 which is mounted for rotation about the intermediate shaft 24. The spindle sleeve 56 includes a set of driving teeth 60 at the forward end thereof which are permanently in engagement with the teeth of a spindle drive gear 62. The spindle drive gear 62 is mounted non-rotatably on the spindle 18 by way of a driving gear 64 which has a set of teeth formed on the internal circumferential surface thereof which are permanently engaged with a set of drive teeth 66 formed on the outer cylindrical surface of the spindle 18. Thus, when the spindle drive sleeve 56 is rotatably driven, the spindle 18 is rotatably driven, and this rotary drive is transferred to the tool or bit by way of the tool holder 16. The drive sleeve 56 has a driven gear 58 located at a rearward end of the drive sleeve which can be selectively driven by the intermediate shaft driving gear 50 by way of the mode change mechanism.
The mode change mechanism, which can be used to selectively actuate the hammer drive arrangement and/or the spindle drive arrangement, includes the mode change member 68 which is slideably mounted within the housing on guide members (not shown) mounted within or formed integrally with the housing. The mode change member 68 is formed with a set of spindle lock teeth 70 which can be selectively engaged with the spindle drive gear 62 to lock the spindle, against rotation, by way of the drive gear. The mode change membr 68 has a mode change ring 72 secured to a central region thereof so that the ring extends laterally of the member. The mode change ring 72 is slideably mounted over a mode change sleeve 52. A pair of coil springs, forward spring 76 and rearward spring 78, are mounted surrounding the mode change sleeve 52 in order to position the mode change ring 72 with respect to the mode change sleeve. The forward spring 76 acts between an annular flange 84, located towards the forward end of the mode change sleeve 52, and the forward annular face of the mode change ring 72. The rearward spring 78 acts between the rearward annular face of the mode change ring 72 and a stop ring 80, which is mounted towards the rearward end of the mode change sleeve 52 by a snap ring 82.
As shown in FIG. 2a, the rotary hammer is in the rotary drive only mode in which the spindle 18 is driven rotationally and the hammer drive arrangement is disengaged. The mode change knob 8 is in the farthest position to which it can be rotated in a clockwise direction and so the eccentric pin 14 lies forwardly of the axis 12 of the knob and maintains the mode change member 68 in the forwardmost position. In this position, the spindle lock teeth 70 are located forward of the spindle drive gear 62 which is free to rotate in order to rotationally drive the spindle 18. The mode changing ring 72 is in its forwardmost position and urges the mode change sleeve 52 forwardly by way of the spring 76. In this manner, the internal teeth 54 of the sleeve 52 are disengaged from the hammer drive splines 48 on the hammer drive sleeve 34 and so that the internal teeth 54 of the mode change sleeve 52 are engaged with the driving gear 50 on the intermediate shaft 24 and the driven gear 58 on the spindle drive sleeve 56.
As shown in FIG. 2b, the rotary hammer is in the rotary hammer mode in which the spindle 18 is driven rotationally and the hammer drive is engaged. The mode change knob 8 is in an intermediate position and the eccentric pin 14 is located above the axis 12 of the mode change knob and maintains the mode change member 68 in an intermediate position. In this position, the spindle lock teeth 70 remain located forward of the spindle drive gear 62, which is free to rotate in order to rotationally drive the spindle 18. The mode change ring 72 is in an intermediate position and urges the mode change sleeve 52 into an intermediary position by way of the spring 76 or the spring 78, depending on the previous mode of operation of the rotary hammer. In this intermediate position, the internal teeth 54 of the sleeve 52 are engaged with the hammer driven splines 48 on the hammer drive sleeve 34 and with the driving gear 58 on the spindle drive sleeve 56.
As the internal teeth 54 are engaged with the hammer driven splines 48, rotation of the intermediate shaft 24 is transmitted to the hammer drive sleeve 34 which rotates with the intermediate shaft. Thus, rotary drive from the motor is translated into a reciprocating drive of the hollow piston 20 by way of the driving gear 50 of the intermediate shaft, the mode change sleeve 52, the hammer driven splines 48 on the hammer drive sleeve 34 and the wobble plate mechanism, whereby hammering action occurs. The engagement of the internal teeth 54 of the mode change sleeve 52 with the driving gear 50 of the intermediate shaft 24 and the driven gear 58 of the spline drive sleeve 56 transmits rotary drive from the intermediate shaft to the spindle drive sleeve 52. This rotary drive is then transmitted to the spindle 18 by way of the driving teeth 60 on the spindle drive sleeve 56, the spindle drive gear 62 and the spindle drive ring 64. Accordingly, the rotary hammer operates in the rotary hammer mode. Note that the rotary hammer can be moved into the rotary hammer mode by rotating the mode change knob 8 either counter-clockwise from the rotary drive only position or clockwise from the hammer only mode position.
A second embodiment of a rotary hammer having a mode change mechanism according to the present invention is shown in FIGS. 3, 4a and 4b. The second embodiment is similar to the first embodiment of the rotary hammer, with like parts identified by like numerals, the difference being that the spindle drive member is a spindle drive pinion 56′. As shown in FIGS. 3, 4a and 4b, the front end of a motor drives the intermediate shaft 24 of the rotary hammer by way of a motor pinion 23 and the drive gear 32 of the intermediate shaft. In this way, the intermediate shaft 24 is always driven in rotation when the motor is switched on. The spindle drive pinion 56′ has a rearward axial projection 70 which is rotatably mounted within a co-operating recess 72 within the front part of the intermediate shaft 24 by way of a needle bearing 74. Thus, the spindle drive pinion 56′ can rotate relative to the intermediate shaft 24. The forward end of the spindle drive pinion 56′ is rotatably mounted in a bearing 28 mounted in the rotary hammer housing. In the same way described above, rotary drive is transmitted from the intermediate shaft 24 to the spindle drive pinion 56′ by the mode change sleeve 52 to rotatably drive the spindle 18 by way of the spindle drive gear 62.
The hammer drive sleeve 34 and intermediate shaft are supported by an intermediate support bearing arrangement 129. The hammer drive sleeve 34 has formed on its external surface, forwardly of the wobble bearing arrangement 36, 38, 39, an annular channel 140 within which runs a set of bearing balls 142. The bearing balls 142 run between an inner race formed within the annular channel 140 of the hammer drive sleeve 34 and an outer race 144 formed in a bearing ring 146. The bearing ring 146 is used to support the intermediate shaft 24 and hammer drive sleeve 34 within the housing 2, 4. Thus, the intermediate shaft 24 is supported in the housing parts 2 and 4 by the rearward bearing 26, the forward bearing 28, and the intermediate support bearing arrangement 129 via the hammer drive sleeve 34. While the embodiments described above refer to rotary hammers within which the motor is in line with the hammer spindle (i.e., parallel thereto), the mode change mechanism is also suitable for the so called L-shaped hammers in which the axis of the motor is perpendicular to the spindle. In such L-shaped rotary hammers, the motor pinion will extend into the hammer housing from below and will mesh with an intermediate shaft drive gear (replacing the gear 32) which is a bevel gear.
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