Rotary hammer

Abstract

A 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 facilitates repeated impacting of the bit or tool for reciprocation within the tool holder (16). A mode change mechanism includes a knob 18 for selectively operating the rotary hammer in any of three modes, identified as a rotary drive only mode, a hammer only mode and a rotary hammer mode.

Description

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.

In general, the above-identified embodiments are not to be construed as limiting the breadth of the present invention. Modifications, and other alternative constructions, will be apparent which are within the spirit and scope of the invention as defined in the appended claims.

Claims

1. A rotary hammer, which comprises:

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:

a driven member (54) on the mode change sleeve (52);

a driving member (50) mounted non-rotatably on the intermediate shaft (24) in permanent engagement with the driven member (54), so that rotation of the intermediate shaft rotatably drives the mode change sleeve.

3. The rotary hammer according to claim 1, which further comprises:

a driving member (54) on the mode change sleeve (52);

a driven member (48) on the hammer drive sleeve (34); and

wherein the hammer drive sleeve (34) is located towards the rear of the mode change sleeve (52) and the driven member (48) is engageable with the drive member (54) to transmit rotary drive from the intermediate shaft (24) to the hammer drive sleeve (34).

4. The rotary hammer according to claim 3, wherein a driven member (54) on the mode change sleeve (52) which engages a driving member (50) on the intermediate shaft (24) is axially extended to form the driving member (54) of the mode change sleeve (52) which is engageable with the driven member (48) on the hammer drive sleeve (34).

5. The rotary hammer according to claim 1, which further comprises:

a driven member (58) on the spindle drive member (56);

a driving member (54) on the mode change sleeve (52); and

wherein the spindle drive member (56) is located towards the front of the mode change sleeve (52) and the driven member (58) is engageable with the driving member (54) to transmit rotary drive from the intermediate shaft (24) to the spindle drive member (56).

6. The rotary hammer according to claim 5, wherein a driven member (54) of the mode change sleeve (52) which engages a driving member (50) of the intermediate shaft (24) is axially extended to form the driving member (54) which is engageable with the driven member (58) on the spindle drive sleeve (56).

7. The rotary hammer according to claim 1, which further comprises:

a driven member (48) on the hammer drive sleeve (34);

a driving member (54) on the mode change sleeve (52);

a driven member (58) on the spindle drive member (56);

the hammer drive sleeve (34) is located towards the rear of the mode change sleeve (52) and the driven member is engageable with the driving member (54) to transmit rotary drive from the intermediate shaft (24) to the hammer drive sleeve (34);

the spindle drive member (56) is located towards the front of the mode change sleeve (52) and the driven member (58) is engageable with the driving member (54) to transmit rotary drive from the intermediate shaft (24) to the spindle drive member (56); and

the mode change mechanism is arranged such that in a first rotary drive only position the mode change sleeve (52) is shifted to a forward position on the intermediate shaft (24) to transmit rotary drive to spindle driving member (56) through the driving member (54) and the driven member 58, in a second hammer only position the mode change sleeve (52) is shifted to a rearward position on the intermediate shaft (24) to transmit rotary drive to the hammer driving sleeve (34) through the driving member (54) and the driven member (48), and in a third rotary hammer position the mode change sleeve (52) is shifted to an intermediate position on the intermediate shaft (24) between the forward and rearward positions and transmits rotary drive to the spindle driving member (56) through the driving member (54) and the driven member (58) and transmits rotary drive to the hammer driving sleeve (34) through the driving member (54) and the driven member (48).

8. The rotary hammer according to claim 1, which further comprises:

a mode changing member (68); and

wherein the switching of the single actuator (8) shifts the mode change sleeve (52) through the mode change member (68).

9. The rotary hammer according to claim 8, which further comprises:

a housing part (2,4); and

the mode change member (68) is mounted on the housing part (2,4) of the rotary hammer so as to be slideable in a direction substantially parallel to the intermediate shaft (24).

10. The rotary hammer according to claim 8, which further comprises:

a mode change arm (72) on the mode change member (68); and

wherein the mode change arm (72) extends laterally of the mode change member (68) with the arm (72) surrounding at least a part of the mode change sleeve (52) and is connected to the mode change sleeve (52) such that shifting of the mode change member (68) shifts the mode change sleeve (52) through the mode change arm (72) amongst the three mode positions.

11. The rotary hammer according to claim 8, which further comprises:

a housing part (2,4);

a rotatable knob (8) forms the actuator (8) and is mounted on the housing part (2,4);

an eccentric pin (14) on the rotatable knob (8); and

wherein when the rotatable knob (8) is rotated the eccentric pin (14) is rotated and slideably engages with the mode change member (68) in order to shift the mode change member (68) to shift the mode change sleeve (52) amongst its three positions.

12. The rotary hammer according to claim 1, which further comprises:

a biasing arrangement (76,78) which is located between the actuator 8 and the mode change sleeve (52) in order to bias the mode change sleeve (52) towards the position on the intermediate shaft (24) which corresponds to the position to which the actuator (8) is switched.

13. The rotary hammer according to claim 1, which further comprises:

a mode change member (68);

a mode change arm (72) on the mode change member (68);

a biasing arrangement (76,78), which comprises:

a first spring member (76); and

a second spring member (78);

wherein the mode change arm (72) extends laterally of the mode change member (68) and at least partly surrounds a part of the mode change sleeve (52) and is connected to the mode change sleeve (52) such that shifting of the mode change member (68) shifts the mode change sleeve (52) through the mode change arm (72) amongst its three positions;

the biasing arrangement (76,78) located between the actuator (8) and the mode change sleeve (52) in order to bias the mode change sleeve (52) towards the position on the intermediate shaft (24) which corresponds to the position to which the actuator (8) is switched; and

the first spring member (76) located between a forward end of the mode change sleeve (52) and a forward facing part of the mode change arm (72) and the second spring member (78) located between a rearward end of the mode change sleeve (52) and a rearward facing part of the mode change arm (72).

14. The rotary hammer according to claim 1, which further comprises;

a spindle lock (70) to lock the spindle (18) against rotation when the rotary hammer is in a hammer only mode.

15. The rotary hammer according to claim 14, which further comprises:

a mode change member (68);

the spindle lock (70) comprising:

a first locking member (70); and

a second locking member (62,64); and

wherein the switching of the single actuator (8) shifts the mode change sleeve (52) through the mode change member (68) and the first locking member (70) is located on the mode change member (68) and engages the second locking member (62,64) located on the spindle (18) when the mode change member (68) is shifted to a hammer only mode position to lock the spindle (18) against rotation.

16. The rotary hammer according to claim 1, which further comprises:

the pneumatic hammering arrangement comprising:

a ram (21);

a reciprocally driven piston (20) which is reciprocally drives the ram (21) through a closed air cushion; and

an anvil (22) which is repeatedly impacted by the ram (21) and, in turn, impacts the bit or tool held in the tool holder (16).

17. The rotary hammer according to claim 1, wherein the intermediate shaft (24) is substantially parallel to the spindle (18).

18. The rotary hammer according to claim 1, wherein:

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).

20. The rotary hammer according to claim 1, which further comprises:

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.