U.S. patent application number 10/181828 was filed with the patent office on 2003-05-15 for hand machine tool.
Invention is credited to Heckmann, Marcus, Wanek, Helmut.
Application Number | 20030089509 10/181828 |
Document ID | / |
Family ID | 27623801 |
Filed Date | 2003-05-15 |
United States Patent
Application |
20030089509 |
Kind Code |
A1 |
Wanek, Helmut ; et
al. |
May 15, 2003 |
Hand machine tool
Abstract
A hand-operated machine tool is disclosed that rotationally
drills or percussively chips or both. An embodiment of the
hand-operated machine tool includes a toolholder that is used to
hold tools having a grooved shank. The toolholder has a toolholder
body and at least one radially moving locking member, for example a
locking sphere, that is insertable into a groove in the tool and
the locking member is radially locked in position by a retaining
element that may be displaced by an actuating element to a position
that radially releases the locking member. In an embodiment of the
invention, the toolholder has at least one sealing device that
seals at least one chamber outwardly surrounding the locking
member. The sealing device includes at least one sleeve-shaped
component that is separate from the actuating element and at least
partially defines the volume referred to as the chamber.
Inventors: |
Wanek, Helmut;
(Bietigheim-Bissingen, DE) ; Heckmann, Marcus;
(Leinfelden-Echterdingen, DE) |
Correspondence
Address: |
KENYON & KENYON
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
27623801 |
Appl. No.: |
10/181828 |
Filed: |
October 2, 2002 |
PCT Filed: |
January 9, 2001 |
PCT NO: |
PCT/DE01/00045 |
Current U.S.
Class: |
173/48 ;
173/47 |
Current CPC
Class: |
B25D 17/088 20130101;
B25D 2217/0065 20130101; B25D 2217/0042 20130101 |
Class at
Publication: |
173/48 ;
173/47 |
International
Class: |
E21B 001/00 |
Claims
What is claimed is:
1. A hand-operated machine tool, in particular a drilling and/or
chipping hammer, comprising a percussively and/or rotationally
driven toolholder (10), which is used to hold tools having a
grooved shank and includes a toolholder body (12) having at least
one radially moving locking member (14), which in turn is
insertable into a groove of the tool closed at the shank end and is
held in its locked position by a retaining element (16) that may be
placed by an actuating element (18) in a position that radially
releases the locking member (14); and comprising at least one
sealing device (20, 22, 24, 26, 28) that outwardly seals at least
one chamber (30, 32) surrounding a locking member (14), wherein the
sealing device (20, 22, 24, 26, 28) has at least one sleeve-shaped
component (34, 36, 38, 40, 42, 44) that is separate from the
actuating element (18) and at least partially delimits the chamber
(30, 32) in the radial direction.
2. The hand-operated machine tool according to claim 1, wherein the
actuating element (18) has least one radial distance (110) from the
sleeve-shaped component (34, 36, 38, 40, 42, 44).
3. The hand-operated machine tool according to claim 1 or 2,
wherein the sealing device (20, 22, 24, 26, 28) has at least one
sleeve-shaped, elastically deformable component (34, 36, 38, 40,
42).
4. The hand-operated machine tool according to one of the preceding
claims, wherein at least one sealing surface pair (48, 50, 52) is
held together by a compression spring (46) that holds the retaining
element (16) in its retaining position.
5. The hand-operated machine tool according to claim 4, wherein the
sleeve-shaped component (38) surrounds the compression spring (46)
and seals its ends against neighboring components (54, 56).
6. The hand-operated machine tool according to one of the preceding
claims, wherein one sealing surface pair (58, 60) is situated
axially in front of the locking member (14) and one sealing surface
pair (62, 64) is situated axially behind the locking member (14),
and, in the case of both sealing surface pairs (58, 60, 62, 64),
one sealing surface is formed by the toolholder body (12) or by a
component (54, 66) attached to the toolholder body (12).
7. The hand-operated machine tool according to one of the preceding
claims, wherein a lubricant is introduced into the chamber (30,
32).
8. The hand-operated machine tool according to one of the preceding
claims, wherein at least one sleeve-shaped component (40, 42)
engages with at least one groove (68) in the toolholder body
(12).
9. The hand-operated machine tool according to one of the preceding
claims, wherein a labyrinth seal (72) is situated between the
actuating element (18) and a neighboring component (70).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a hand-operated machine
tool for percussively chipping, rotationally drilling, or both.
BACKGROUND OF THE INVENTION
[0002] A drilling hammer having a rotationally and percussively
driven toolholder is known from German Patent 197 24 532.3. The
toolholder has a body that is designed in a single piece with a
spindle sleeve. The toolholder body has a seating bore into which a
shank of a tool can be inserted and locked in place by a locking
device. The locking device has a locking sphere that is provided in
an opening in the toolholder body and can be inserted into a groove
in a tool that is closed at the shank end.
[0003] In a locked position, the locking sphere is covered radially
to the outside by a retaining sleeve. The retaining sleeve is
mounted on the toolholder body so that it can move in the axial
direction. Using an actuating sleeve, the retaining sleeve can be
moved axially in the tool insertion direction and against the force
of a pre-tensioned helical spring into an unlocked position in
which a clearance within the retaining sleeve allows the locking
sphere to move radially out of the groove in the tool shank,
thereby releasing the tool.
[0004] The spindle sleeve is provided in a machine housing. A
sleeve-shaped extension of the actuating sleeve engages with an end
of the machine housing on the tool side. To enable the actuating
sleeve to move relative to the machine housing, an annular gap is
provided between the extension and the machine housing. The
actuating sleeve limits a chamber surrounding the locking sphere
radially to the outside, with this chamber being limited to the
inside by the toolholder body. The chamber is protected against
dust on the tool side by a dust cap, which is mounted on the
toolholder body and provides a seal radially inward toward the
toolholder body and radially outward toward the actuating sleeve.
On the machine side, the chamber is protected against the
penetration of boring dust by a sealing device.
[0005] The sealing device has a seating ring that supports the
helical spring on the machine side and, for this purpose, has a
cylindrical guide extension for the helical spring. The seating
ring is axially secured on the machine side on a shoulder of the
spindle sleeve. Circumferential grooves are provided in the inner
and outer circumferences of the seating ring, in each of which is
provided a sealing ring. The outer sealing ring provided in the
radially outer circumferential groove seals the chamber between the
actuating sleeve and the seating ring, while the inner sealing ring
provided in the radially inner circumferential groove seals the
chamber between the seating ring and the toolholder body.
[0006] German Patent Application 198 05 187 discloses a
hand-operated machine that includes a toolholder that is
percussively and/or rotationally driven and is used to hold tools
having a grooved shank. The toolholder includes a toolholder body
having a radially moving locking member that is inserted into the
grooved shank of a tool. The locking member is closed at the shank
end and is held in its locked position by a retaining element. The
retaining element is positioned by an actuating element in an
unlocked position that radially releases the locking member. Also,
the hand-operated machine tool has a lubricant storage unit that is
formed by a sleeve-shaped component and surrounds the toolholder
body downstream from the locking member in the direction of
machining. The lubricant storage unit is connected by a valve body
to a seating area of the toolholder body via a connecting line. A
spherical obstruction forms the valve body, and is covered radially
by a spring-loaded ring. The spherical obstruction is pressed
radially inward toward the seating area against a valve seat,
closing the valve body, preventing lubricant in the lubricant
storage area from reaching the seating area of the toolholder body
through the connecting line.
[0007] The valve body and valve seat of German Pact Application 198
05 187 form a throttle valve for the lubricant. In the locked
position, the spherical obstruction projects partially into the
seating area. When the tool is inserted, the spherical obstruction
is pushed radially outward, and therefore, the valve opens and
lubricant passes through the connecting line to the seating area of
the toolholder. After the tool has been inserted, the spherical
obstruction is located in the groove on the shank of the tool;
therefore, the obstruction is reseated in the valve seat of the
valve body by the spring-loaded ring, thus closing the valve and
sealing off the lubricant storage unit.
SUMMARY OF THE INVENTION
[0008] The invention concerns a hand-operated machine that
percussively chips, rotationally drills or both and that includes a
toolholder that is driven percussively, rotationally or both. The
toolholder is used to hold tools having a grooved shank. The
toolholder comprises a toolholder body and at least one radially
moving locking member. The radially moving locking member, for
example a locking sphere, fits into the groove in the shank of the
tool, locking the tool in the toolholder. The locking member is
held in its locked position by a retaining element. The retaining
element is positioned in its unlocked position by an actuating
element that radially releases the locking member. The toolholder
includes at least one sealing device. The sealing device at least
partially defines a chamber or several chambers, which are at least
partially enclosed volumes. At least one chamber is an enclosed
volume surrounding the locking member. The sealing device prevents
at least a significant amount of dust penetration, reducing wear on
the tool and the toolholder body, providing for a longer service
life.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a schematic representation of one embodiment of
a toolholder for a hand-operated machine according to the present
invention.
[0010] FIG. 2 illustrates another embodiment of the toolholder.
[0011] FIG. 3 illustrates an alternative embodiment of the
toolholder illustrated by FIG. 2.
[0012] FIG. 4 shows yet another embodiment of the invention.
[0013] FIG. 5 shows still yet another embodiment of the
invention.
[0014] FIG. 6 shows an enlarged view of the elastically deformable
sealing sleeve of the embodiment of the invention as illustrated by
FIG. 5.
[0015] FIG. 7 illustrates the elastically deformable sealing sleeve
of FIG. 6 in its extended position, when the actuating sleeve of
the embodiment shown in FIG. 5 is deployed axially in the direction
of the shank end of the tool, releasing the locking sphere of the
toolholder.
DETAILED DESCRIPTION
[0016] According to one embodiment of the invention, the sealing
device has at least one sleeve-shaped component that is separated
from the actuating element and at least partially delimits, in the
radial direction, the enclosed volume that is referred to herein as
the chamber. The chamber, in this embodiment is formed
independently of the actuating element, and the sealing device
seals the chamber via a pair of sealing surfaces that rest against
each other at least during operation. The pair of sealing surfaces
contact each other even when the actuating element is stationary
and the toolholder body is rotating, for example when the actuating
element comes into contact with the wall during operation.
[0017] To minimize friction between the actuating element and the
sleeve-shaped component when the actuating element is stationary
and the sleeve-shaped component is moving, in one embodiment of the
invention, there is a space, radially, between at least a portion
of the inner surface of the sleeve-shaped component and the
actuating element.
[0018] According to a further embodiment of the invention, the
sealing device has at least one elastically deformable,
sleeve-shaped component, for example a rubber sleeve, and pairs of
sealing surfaces always remain in contact, even when the retaining
element is in motion. The pairs of sealing surfaces, according to
this embodiment, may be held in contact with large contact forces
without hindering movement or generating friction.
[0019] In one specific embodiment, at least one portion of a pair
of sealing surfaces is held together by a compression spring that
also holds the retaining element in its retaining position, and the
large contact forces that create the sealing action are achieved
between the pair of sealing surfaces without requiring additional
components. In another specific embodiment, the elastically
deformable, sleeve-shaped component surrounds the compression
spring and seals its ends against neighboring components, allowing
the compression spring and the elastically deformable,
sleeve-shaped component to be designed as a preassembled unit. In
yet another embodiment, an elastically deformable, sleeve-shaped
component is injection-molded around the compression spring. In
alternative embodiments, a compression spring surrounded by the
sleeve-shaped component provides a simple dust sealing arrangement
and, alternatively, the sleeve-shaped component may be provided
radially within the compression spring or radially outside the
compression spring.
[0020] According to a further embodiment of the present invention,
one sealing surface pair is provided axially upstream from the
locking member and one sealing surface pair is provided axially
downstream from the locking member, and, in the case of both
sealing surface pairs, one sealing surface is formed by the
toolholder body or by a component attached to the toolholder body.
The sealing action of the sealing device may be improved, and, in
particular, a chamber surrounding the locking member may be
provided in which a lubricant is advantageously provided and which
may be used not only for initial lubrication, but also for
continuous force-feed lubrication. An existing recess for the
locking member may be advantageously used to supply lubricant to
the chamber and discharge lubricant from the chamber to a seating
area of the toolholder, lubricating the seating area of the
toolholder and reducing wear. This may eliminate the need for
additional recesses and components for force-feed lubrication.
[0021] A good sealing action is achievable through simple design
means by having the sleeve-shaped component engage with at least
one groove in the toolholder body. An additional cost-effective
sealing action is also achievable by providing a labyrinth seal
between the actuating element and a neighboring component, for
example a protective cap mounted on the toolholder body. A
labyrinth seal makes it possible to prevent dust and dirt from
penetrating the sleeve-shaped component and lubricant from exiting
the chamber to the outside.
[0022] FIG. 1 shows a cross section of a drilling hammer having a
rotationally and percussively driven toolholder 10, provided in a
lower housing shell 84, for holding tools that have a grooved
shank. The toolholder 10 has a body 12 having a radially moving
locking sphere 14 that is insertable into a groove in the tool that
is closed at the shank end and the locking sphere is held in its
locked position by a retaining sleeve 16, movable within limits in
the axial direction, and a holding sleeve 56.
[0023] The retaining sleeve 16 is loaded via the holding sleeve 56
by a compression spring 46 in the direction of its retaining
position (to the right in FIG. 1, for example). The compression
spring 46 is supported on a seating ring 54 on the machine side (to
the left in FIG. 1, for example). The retaining sleeve 16 is
supported by a ring 76 and a snap ring 78 on the toolholder body 12
on the side facing away from the compression spring 46. When the
locking sphere 14 is in the locked position, the retaining sleeve
16 covers the locking sphere 14 radially, and the holding sleeve 56
secures the locking sphere 14 in the axial direction.
[0024] When the tool is inserted, the locking sphere 14 is pushed
in the direction of the machine side by the shank of the tool into
a recess 74. The holding sleeve 56 is pushed over the locking
sphere 14 against the compression spring 46, which produces a
clearance between the retaining sleeve 16 and the holding sleeve 56
into which the locking sphere 14 is radially moved outwardly.
Therefore, the locking sphere is displaced and the tool may be
inserted completely. Then, the compression spring 46 pushes the
holding sleeve 56 into its original position, forcing the
displacement of the locking sphere 14 into the groove in the shank
of the tool. To drive rotation, the toolholder has rotary driving
webs 82 provided in a seating bore 80 of the toolholder body 12,
and the rotary driving webs engage with the open grooves at the end
of the shank of the tool.
[0025] To remove the tool, an actuating sleeve 18 is displaced in
the machine direction, pushing the retaining sleeve 16 against the
holding sleeve 56 and against the compression spring 46 that loads
the holding sleeve 56, such that the locking sphere 14 is moved
radially outward, allowing the tool to be removed. The compression
spring then presses holding sleeve 56, retaining sleeve 16, locking
sphere 14 and actuating sleeve 18 back into their original
positions.
[0026] The toolholder 10 has a sealing device 20 that seals a
chamber 30 outwardly surrounding the locking sphere 14. According
to one embodiment of the present invention, the sealing device 20
has an elastically deformable rubber sleeve 34 that is separate
from the actuating sleeve 18 and radially defines the volume
referred to herein as the chamber 30 and surrounds the seating ring
54, compression spring 46, holding sleeve 56 and retaining sleeve
16. The rubber sleeve 34 seals the chamber 30 to the outside at the
seating ring 54 and at the retaining sleeve 16. At the tool end of
toolholder body 12, a dust cap 86 is fastened in a form-fitting
manner by an interlocking connection 88 that seals the tool-side
area of the locking sphere 14 against dust via a diaphragm gland 90
in the direction of the actuating sleeve 18. A rivet set 112, which
seals the seating bore 80 on the machine side via seals (not
illustrated in further detail) in grooves 114, 116, is also
provided in toolholder 10.
[0027] Regardless of whether the lock between the tool and
toolholder 10 is released by moving the retaining sleeve 16 against
the compression spring 46, using the actuating sleeve 18, or
whether the tool shank is locked in position by the locking sphere,
the rubber sleeve 34 is able to elastically deform without causing
either of the pairs of sealing surfaces 92, 94 to either separate
or move closer together, for example, between the seating ring 54
and the rubber sleeve 34 and between the rubber sleeve 34 and the
retaining sleeve 16. To prevent either of the pairs of sealing
surfaces from either separating or moving closer together, the
rubber sleeve 34 is braced by the seating ring 54 and the retaining
sleeve 16, i.e., joined in a force-locking manner.
[0028] In a further embodiment, the actuating sleeve 18 is
positioned at a radial and axial distance 110 from rubber sleeve
34. When the actuating sleeve 18 comes into contact with a fixed
wall during operation, thus causing the actuating sleeve 18 to come
to a standstill, the rubber sleeve 34 can continue to rotate along
with the toolholder body 12. This prevents wear between the rubber
sleeve 34 and the actuating sleeve 18.
[0029] The chamber 30 is filled via a recess 74 with a viscous and
temperature-resistant lubricant, which is not illustrated in
greater detail, for the lubrication of seating bore 80. When the
tool is inserted, the locking sphere 14 is pushed radially to the
outside, the volume in the chamber 30 is reduced, and the lubricant
is pressed out of the chamber 30 into the seating bore 80.
[0030] FIG. 2 shows another exemplary embodiment of the invention
comprising a sealing device 22. In the embodiments described
herein, similar components, from one example to the next, are
identified by the same reference numbers. The sealing device 22 of
this embodiment has an elastically deformable rubber sleeve 36 that
surrounds a compression spring 46 and a holding sleeve 56 and
outwardly seals a chamber 30 against a seating ring 54 and a
retaining sleeve 16. The pairs of sealing surface 48, 50 between
the seating ring 54 and the rubber sleeve 36 and between the rubber
sleeve 36 and the retaining sleeve 16, respectively, are held in
contact by the compression spring 46.
[0031] An embodiment of the invention, as illustrated in FIG. 3,
comprises a sealing device 24 that comprises an elastically
deformable rubber sleeve 38, which forms a preassembled unit
together with a compression spring 46. The rubber sleeve 38
surrounds the compression spring 46 and outwardly seals the ends of
a chamber 30 in the direction of a seating ring 54 and a holding
sleeve 56. In this embodiment, the pairs of sealing surfaces 48, 52
are between the seating ring 54 and the rubber sleeve 38 and
between the rubber sleeve 38 and a holding sleeve 56 and are held
in contact by the compression spring 46.
[0032] In another embodiment, as illustrated in FIG. 4, a sealing
device 26 comprises an elastically deformable rubber sleeve 40 that
surrounds a seating ring 54, compression spring 46, holding sleeve
56, retaining sleeve 16, ring 76 and snap ring 78 and seals a
chamber 32 toward the seating ring 54 and a toolholder body 12. On
the machine side, the rubber sleeve 40 surrounds the seating ring
54 radially from both axial sides and, on the tool side, engages
with a groove 68 of the toolholder body 12. One pair of sealing
surfaces 58 is provided axially in the machine direction and one
pair of sealing surfaces 62 is provided axially in the direction of
the tool. To achieve a stable seating of the rubber sleeve, as well
as high wear-resistance, the rubber sleeve may be reinforced by a
fabric in different areas, for example in the area of the seating
ring 54, compression spring 46, holding sleeve 56 and/or retaining
sleeve 16.
[0033] By displacing the actuating sleeve in the machine direction,
the retaining sleeve 16 is moved against the compression spring 46
via the rubber sleeve 40 and the ring 76. The rubber sleeve 40 is
thereby elastically deformed, with the sealing surfaces of the
pairs of sealing surfaces 58, 62 always contacting each other.
[0034] A viscous and heat-resistant lubricant is provided in the
chamber 32 for continuous force-fed lubrication via the recess 74.
For example, when a tool is inserted into the toolholder 10, the
locking sphere 14 is moved radially outward. Then, the volume in
the chamber 32 is reduced, and the lubricant is pressed through the
recess 74 into the seating bore 80. In one embodiment, the area
around the rubber sleeve 40 is also sealed by an O-ring 96 between
the actuating sleeve 18 and the housing shells 84 and by a
labyrinth seal 72 between the actuating sleeve 18 and a neighboring
component, for example a dust cap 70.
[0035] The embodiment illustrated by FIG. 5 comprises a sealing
device comprising an elastically deformable rubber sleeve 42, which
is folded in multiple layers and which is provided on the tool
side, and a sheet-metal sleeve 44 which is provided on the machine
side. The sheet-metal sleeve 44 seals the chamber 32 against a
circumferential O-ring 66 on the machine side, with the
circumferential O-ring being fastened in a circumferential groove
100 in a seating ring 98 for a compression spring 46. The chamber
32 is sealed between a seating ring 98 and the toolholder body 12
by an seating O-ring 102 via which the seating ring 98 is supported
on a shoulder 104 of the toolholder body 12 on the machine side. On
the tool side, the seating ring 98 is supported on the toolholder
body 12 via a clamping ring 106. On the tool side, the rubber
sleeve 42 seals the chamber 32 between the sheet-metal sleeve 44
and the retaining sleeve 16 at a first end, and the rubber sleeve
42 and the toolholder body 12 at its second end. At its second end,
the rubber sleeve 42 engages with a groove 68 in the toolholder
body 12. The sheet-metal sleeve 44 and the circumferential O-ring
66 forms a pair of sealing surfaces 60 in the machine direction,
and the rubber sleeve 42 and the toolholder body 12 forms another
pair of sealing surfaces 64 in the tool direction.
[0036] By axially displacing, in the machine direction, the
actuating sleeve 18, the retaining sleeve 16 is moved against the
compression spring 46, and the actuating sleeve 18 engages the
rubber sleeve 42, at a location radially outside of a multiple-fold
area 108 of the rubber sleeve 42, allowing the multiple-fold area
108 to unfold, and enabling the locking sphere to displace,
unlocking the tool.
[0037] FIG. 6 shows, for example, the rubber sleeve 42 in the
locked position, and FIG. 7 shows, for example, the rubber sleeve
42 in an unlocked position. For example, the sheet-metal sleeve 44
slides over the circumferential O-ring 66. As in the exemplary
embodiment illustrated in FIG. 4, a viscous and heat-resistant
lubricant is provided in the chamber 32 for continuous force-fed
lubrication via the recess 74.
[0038] Reference numbers
[0039] 10 Toolholder
[0040] 12 Toolholder body
[0041] 14 Locking member
[0042] 16 Retaining element
[0043] 18 Actuating element
[0044] 20 Sealing device
[0045] 22 Sealing device
[0046] 24 Sealing device
[0047] 26 Sealing device
[0048] 28 Sealing device
[0049] 30 Chamber
[0050] 32 Chamber
[0051] 34 Component
[0052] 36 Component
[0053] 38 Component
[0054] 40 Component
[0055] 42 Component
[0056] 44 Component
[0057] 46 Compression spring
[0058] 48 Sealing surface pair
[0059] 50 Sealing surface pair
[0060] 52 Sealing surface pair
[0061] 54 Component
[0062] 56 Component
[0063] 58 Sealing surface pair
[0064] 60 Sealing surface pair
[0065] 62 Sealing surface pair
[0066] 64 Sealing surface pair
[0067] 66 Component
[0068] 68 Groove
[0069] 70 Component
[0070] 72 Labyrinth seal
[0071] 74 Recess
[0072] 76 Ring
[0073] 78 Snap ring
[0074] 80 Seating bore
[0075] 82 Rotary driving web
[0076] 84 Housing shell
[0077] 86 Dust cap
[0078] 88 Interlocking connection
[0079] 90 Diaphragm gland
[0080] 92 Sealing surface pair
[0081] 94 Sealing surface pair
[0082] 96 O-ring
[0083] 98 Seating ring
[0084] 100 Groove
[0085] 102 O-ring
[0086] 104 Shoulder
[0087] 106 Clamping ring
[0088] 108 Area
[0089] 110 Distance
[0090] 112 Rivet set
[0091] 114 Groove
[0092] 116 Groove
* * * * *