초록 ▼

A hammer drill (2) includes a clockwise and counterclockwise driven tool spindle (28), a drive pinion (70) operatively connectable with the tool spindle (28) for transmitting a torque thereto, a separate control handle (6) for selecting one of the hammer drill functions including a pure drilling ope

A hammer drill (2) includes a clockwise and counterclockwise driven tool spindle (28), a drive pinion (70) operatively connectable with the tool spindle (28) for transmitting a torque thereto, a separate control handle (6) for selecting one of the hammer drill functions including a pure drilling operation, a pure percussion operation, and a rotary-percussion operation), and a switching device (8) which is adjustable in accordance with a position of the control handle (6) and which is shiftable by the control handle (6) in a clockwise rotation position for effecting a pure drilling operation in a clockwise direction and in a counterclockwise rotation position for effecting a pure drilling operation in a counterclockwise direction.

대표청구항 ▼

What is claimed is: 1. A hammer drill (2) for carrying out a pure drilling operation, a pure percussion operation, and a rotary-percussion operation, comprising: a clockwise and counterclockwise driven tool spindle (28); a drive pinion (70) operationally connectable with the tool spindle (28) for t

What is claimed is: 1. A hammer drill (2) for carrying out a pure drilling operation, a pure percussion operation, and a rotary-percussion operation, comprising: a clockwise and counterclockwise driven tool spindle (28); a drive pinion (70) operationally connectable with the tool spindle (28) for transmitting a torque thereto; a separate control handle (6) rotatable to different positions for selecting one of the pure drilling operation, the pure percussion operation, and the rotary-percussion operation; a switching device (8) adjustable in accordance with a position of the control handle (6) and shiftable by the control handle (6) in a clockwise rotation position for effecting a pure drilling operational in a clockwise direction and in a counterclockwise rotation position for effecting a pure drilling operation in a counterclockwise direction; and an eccentric member (30) for driving a percussion mechanism or the hammer drill (2), and a drive member (34) for driving the eccentric member (30), wherein the switching device (8) comprises coupling means (24) arranged between the eccentric member (30) and the drive member (34). 2. A hammer drill according to claim 1, wherein the switching device (8) includes clockwise drive gear means and counterclockwise drive gear means for alternatively forming a clockwise rotational connection and a counterclockwise rotational connection between the tool spindle (28) and the drive pinion (70) in a pure drilling operation. 3. A hammer drill according to claim 2, wherein the switching device (8) is switchable by the control handle (6) in an additional position in which the clockwise and counterclockwise drive gear means occupies a position in which both the clockwise rotational connection and the counterclockwise rotational connection between the drive pinion (70) and the tool spindle (28) are broken, and the tool spindle (28) is rotatable relative to a hammer drill housing (4). 4. A hammer drill according to claim 2, wherein the clockwise drive gear means and the counterclockwise gear means comprises, respectively, a first drive gear (66) connectable with the tool spindle (28) for providing the clockwise drilling operation, and a second drive gear (68) connectable with the tool spindle (28) for providing the counterclockwise drilling operation, the first and second drive gears (66, 68) having respective tooth surfaces (67, 69) arranged opposite each other. 5. A hammer drill according to claim 4, wherein both the first and second drive gears (66, 68) are permanently connected with the drive pinion (70) and are alternatively rotatably connectable with the tool spindle (28). 6. A hammer drill according to claim 5, wherein the switching device (8) comprises a sleeve-shaped shifting member (54), for rotatably connecting the tool spindle (28) alternatively with one of the first and second drive gears (66,68) and supported on the tool spindle (28) for joint rotation therewith and for axial displacement relative thereto. 7. A hammer drill according to claim 1, wherein the switching device (8) has a chiseling position in which a pure chiseling operation takes place and in which the tool spindle (28) is operatively connected to a hammer drill housing (4) without a possibility of rotation relative thereto. 8. A hammer drill according to claim 7, wherein the switching device (8) comprises a shifting member (54) having engagement means (60) engaging matching engagement means (62) fixedly secured to the housing (4) in the chiseling position of the switching device (8) for preventing rotation of the tool spindle (28) relative to the housing (4). 9. A hammer drill according to claim 1, wherein the coupling means comprises a coupling member (24) permanently rotatably connected with one of the eccentric member (30) and the drive member (34) and rotatably disconnected from another of the eccentric member (30) and the drive member (34) in a switch-off position. 10. A hammer drill according to claim 9, wherein the coupling member (24) has a ramp profile (22); and the switching device (8) has a movable bearing region (20) engaging the ramp profile (22) for displacing the coupling member (24) in an axial direction away from the another of the eccentric member (30) and the drive member (34) upon rotation thereof. 11. A hammer drill according to claim 10, wherein the switching device (8) comprises a shift plate (14) linearly displaceable in the hammer drill (2) and adjustable by the control handle (6), and wherein the bearing region (20) is provided on the shift plate (14). 12. A hammer drill according to claim 11, wherein the switching device (8) comprises a sleeve-shaped shifting member (54) translationally connectable with the shift plate (14). 13. A hammer drill according to claim 11, wherein the shift plate (14) has a tooth profile (12) connected, directly or indirectly, with a rotatable matching tooth profile provided on the control handle (6).