U.S. patent application number 10/594957 was filed with the patent office on 2008-02-21 for manual grinding tool.
Invention is credited to Stephan Rieth.
Application Number | 20080045126 10/594957 |
Document ID | / |
Family ID | 34966901 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080045126 |
Kind Code |
A1 |
Rieth; Stephan |
February 21, 2008 |
Manual Grinding Tool
Abstract
The invention relates to a manual grinding tool comprising a
rotating grinding head (7). The inventive grinding device is
characterised by a guiding device that is connected to the grinding
tool (8) and can be applied to a workpiece (19) in a sliding and/or
rolling manner. The grinding head (7) assumes a fixed position in
terms of the guiding device which is used to press the grinding
tool against the workpiece (19) in at least one direction without
tilting.
Inventors: |
Rieth; Stephan; (St. Wendel,
DE) |
Correspondence
Address: |
FRIEDRICH KUEFFNER
317 MADISON AVENUE, SUITE 910
NEW YORK
NY
10017
US
|
Family ID: |
34966901 |
Appl. No.: |
10/594957 |
Filed: |
March 30, 2005 |
PCT Filed: |
March 30, 2005 |
PCT NO: |
PCT/DE05/00591 |
371 Date: |
August 13, 2007 |
Current U.S.
Class: |
451/294 |
Current CPC
Class: |
B24B 23/005 20130101;
B24B 9/00 20130101; B24B 23/043 20130101 |
Class at
Publication: |
451/294 |
International
Class: |
B24B 23/02 20060101
B24B023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2004 |
DE |
10 2004 016 565.3 |
Aug 19, 2004 |
DE |
10 2004 040 900.5 |
Claims
1. A manual grinding tool comprising a rotating grinding head (7),
comprising a guide device (8) which is connected to the tool and
can be placed against a workpiece (19) in a sliding and/or rolling
manner and with respect to which the grinding head (7) assumes a
fixed position and by means of which the tool can be pressed
against the workpiece (19) in at least one direction in a stable
manner without tilting.
2. The grinding tool as claimed in claim 1, wherein the guide
device (8) can be pressed at at least three bearing points against
the workpiece (19) in two directions in a stable manner without
tilting.
3. The grinding tool as claimed in claim 1, wherein the guide
device (8) has a bearing surface (15) which can be adapted to a
surface of the workpiece (19).
4. The grinding tool as claimed in claim 3, wherein the surface of
the workpiece (19) adjoins an edge (20) of the workpiece (19), and
the grinding head (7) is provided for machining the edge (20)
or/and a marginal surface (14) of the workpiece (19a) adjoining the
workpiece edge.
5. The grinding tool as claimed in claim 4, characterized in that
wherein the guide device (8b) comprises a stop element (23) for
bearing against the marginal surface (14b).
6. The grinding tool as claimed in claim 3, wherein the bearing
surface (15) is formed by an annular surface coaxial to the
grinding head (7).
7. The grinding tool as claimed in claim 1, wherein the grinding
head (7e) is arranged between a plurality of stop elements (34, 35)
of the guide device (8e) which are provided for bearing against a
workpiece surface (32).
8. The grinding tool as claimed in claim 7, wherein the stop
elements (34, 35) have different heights and the rotation axis of
the grinding head (7e) is at a desired angle to the workpiece
surface (32) when the stop elements (34, 35) bear against the
workpiece surface (32).
9. The grinding tool as claimed in claim 1, wherein the guide
device (8b-8d) comprises stop elements (11, 12) acting on opposite
sides of a workpiece (19b-19d).
10. The grinding tool as claimed in claim 1, wherein the guide
device (8, 8a, 8d) is adjustable, in particular for setting the
angles of bevels to be ground and for setting the position of the
grinding point at the grinding head (7).
11. The grinding tool as claimed in claim 10, wherein the guide
device (8d) is pivotable about an axis (25) for setting the bevel
angle.
12. The grinding tool as claimed in claim 10, wherein a drive
device is provided for the adjustment, in particular for the
oscillating adjustment, of the grinding point position.
13. The grinding tool as claimed in claim 12, wherein the drive
device is in drive connection with the drive of the grinding head,
preferably via epicyclic or worm gearing.
14. The grinding tool as claimed in claim 12, wherein the drive
device comprises a separate drive motor or pneumatic cylinder.
Description
[0001] The invention relates to a manual grinding tool comprising a
rotating grinding head.
[0002] In conventional grinding tools of that kind comprising a
grinding head mounted on one side, it is the responsibility of the
user to guide the grinding head as accurately as possible by means
of his arm movements and by exerting appropriate retaining forces
and contact pressures. In order to achieve a high material removal
rate, high contact pressures are necessary, the exertion of which
runs counter to accurate guidance of the grinding head.
[0003] The object of the invention is to provide a novel grinding
tool of the type mentioned at the beginning which enables
workpieces to be machined more precisely at a high material removal
rate.
[0004] The grinding tool, which achieves this object, according to
the invention is characterized by a guide device which is connected
to the tool and can be placed against a workpiece in a sliding
and/or rolling manner and with respect to which the grinding head
assumes a fixed position and by means of which the tool can be
pressed against the workpiece in at least one direction in a stable
manner without tilting.
[0005] Advantageously, the grinding head of such a tool can be
accurately guided at a high contact pressure against the workpiece
by virtue of the fact that the rotation axis of the grinding head
remains at a stable angle in at least one direction, the guide
device permitting degrees of freedom for moving the tool manually
in the feed direction of the grinding head and if need be in the
infeed direction decisive for the removal depth.
[0006] The guide device can advantageously be pressed against the
workpiece with at least three bearing points in two directions in a
stable manner without tilting, so that the grinding head can be
guided with uniform inclination with respect to the workpiece
surface. The bearing points may lie in one plane in accordance with
a flat workpiece surface. However, it is also conceivable to place
the guide device with three bearing points against the lateral
surface of a cylindrical workpiece, whose lateral surface or end
edge is to be machined.
[0007] In an embodiment of the invention, the guide device has a
bearing surface which can be adapted to a workpiece surface, e.g. a
flat bearing surface which can be placed against a side of a
plate-shaped workpiece.
[0008] In an embodiment of the invention, said workpiece surface
adjoins a workpiece edge, and the grinding head is provided for
machining the workpiece edge or/and a marginal surface of the
workpiece adjoining the workpiece edge, e.g. a marginal surface of
a workpiece plate.
[0009] In the last-mentioned embodiment, the bearing surface may be
formed, for example, by an annular surface coaxial to the grinding
head. However, a conceivable guide device would also be a roller
having a rotation axis perpendicular to the rotation axis of the
grinding head, the roller rolling on the workpiece surface
adjoining the marginal surface.
[0010] The user of the tool can exert a contact pressure in such a
direction that one component acts on said workpiece surface and the
other component acts via the grinding head on the marginal surface
to be removed. In particular due to the component acting on the
workpiece surface, the tool is held on the workpiece in a stable
manner without tilting and can be accurately guided at a high
contact pressure.
[0011] Furthermore, the guide device may comprise a stop element
for bearing against the marginal surface. The maximum material
removal can be advantageously limited by such a measure.
[0012] In an alternative embodiment, the grinding head is arranged
between a plurality of stop elements which are provided for bearing
against a workpiece surface. Such a tool can serve to grind the
workpiece surface, it being possible for the stop elements to have
different heights in such a way that the rotation axis of the
grinding head is at a desired angle to the workpiece surface when
the stop elements bear against the workpiece surface. With a
conical surface of the grinding head, provision may thus be made
for the nearest generating line of the grinding head to run
parallel to or tangentially to said surface. Such a grinding tool
can advantageously be used for removing welds projecting from
workpiece surfaces.
[0013] In a further embodiment of the invention, the guide device
may comprise stop elements acting on opposite sides of a workpiece,
e.g. a plate or a pipe, at least one of the stop elements being
movable in order firstly to make it easier to insert the workpiece
into the intermediate space between the stop elements and secondly
to be able to adapt the guide device to different workpiece
thicknesses.
[0014] The guide device may be adjustable and may be pivotable
about an axis in particular for setting different angles of bevels
to be ground and may be capable of being locked in desired pivoted
positions.
[0015] The invention is explained in more detail below with
reference to exemplary embodiments and the attached drawings
referring to these exemplary embodiments. In the drawings:
[0016] FIG. 1 shows a first exemplary embodiment for a grinding
tool according to the invention comprising a conical grinding head
and an annular guide device,
[0017] FIG. 2 shows a second exemplary embodiment for a grinding
tool according to the invention comprising a cylindrical grinding
head and an annular guide device,
[0018] FIG. 3 shows a third exemplary embodiment for a grinding
tool according to the invention comprising a disk-shaped grinding
head and a guide device acting on opposite sides of a
workpiece,
[0019] FIG. 4 shows a fourth exemplary embodiment for a grinding
tool according to the invention comprising a guide device according
to FIG. 3 and a conical grinding head,
[0020] FIG. 5 shows a fifth exemplary embodiment for a grinding
tool according to the invention comprising a guide device pivotable
in its entirety,
[0021] FIG. 6 shows a sixth exemplary embodiment of a grinding tool
according to the invention comprising a grinding head arranged
between stop elements of a guide device,
[0022] FIG. 7 shows a seventh exemplary embodiment for a grinding
tool according to the invention, and
[0023] FIG. 8 shows a further exemplary embodiment for a grinding
tool according to the invention.
[0024] A manual grinding tool has a housing 1 for a motor/gear unit
(which cannot be seen in the figures), a handle 2 with a switch
button 3, and a holding stirrup 4 on the housing end remote from
the handle.
[0025] In a housing extension 5 extending at right angles to the
housing longitudinal axis, a shaft 18 connected to the motor/gear
unit can be rotated about an axis 6. At its end remote from the
housing 1, the shaft 18 is connected to a grinding head 7.
[0026] An annular stop 8 forming a guide and having a flat stop
surface 15 coaxially surrounds the grinding head 7. The housing
extension 5 has a section 9 which comprises the stop 8 and can be
screwed to the rest of the grinding tool. The stop 8 can be axially
adjusted by rotating the section 9 and can be locked by a ring nut
16. A further ring nut 17 serves to connect the grinding head 7 to
the shaft 18.
[0027] As FIG. 1 shows, a bevel can be ground on a marginal edge 20
of a plate-shaped workpiece 19 by means of the grinding tool. By
adjustment of the annular stop 8 in the direction of the axis 6,
the application point or the application surface on the grinding
head 7 can be displaced and uniform wear of the conical grinding
surface of the grinding head can be achieved as a result.
[0028] To adjust the guide or the stop 8 in the direction of the
rotation axis 6 of the grinding head 7, the section. 9 could also
be guided in a rotationally locked manner and be coupled axially to
a freely rotatable nut.
[0029] For the purpose of uniform wear of the grinding surface of
the grinding head, the guide or the stop 8 could oscillate in the
direction of the grinding-head rotation axis 6. A separate drive
motor or pneumatic cylinder could be provided for the oscillating
adjustment. However, an adjusting drive could also be connected to
the drive of the grinding head 7, for example, via epicyclic or
worm gearing. The section 9 may be provided with a winding groove,
in which a guide pin or roller connected to the drive device
engages, so that the encircling guide pin or the encircling roller
displaces the section 9, guided in a rotationally locked manner,
back and forth. FIG. 8 shows a further embodiment having an
oscillating grinding head.
[0030] During the grinding, the user presses the flat stop surface
15 of the annular stop 8 against the plate surface, adjoining the
edge 20, of the workpiece 19. A component of the contact pressure
that is parallel to the plate surface provides for the desired
material removal by the grinding head. A component of the contact
pressure that is perpendicular to the plate surface ensures
guidance of the grinding head 7 in a stable manner without tilting,
the rotation axis 6 of said grinding head 7 merely being displaced
in parallel while maintaining its spatial direction during the
grinding. An increase in the contact pressure advantageously leads
to the increase in both the material removal rate and the tilting
moment, so that the tool can also be reliably guided at a high
contact pressure and a high removal rate.
[0031] Due to the annular shape of the stop 8, the tool is
especially suitable for machining concavely running workpiece
edges.
[0032] The grinding head 7 is described in detail in DE 10 2004 016
565.3 included here.
[0033] In the figures below, identical parts or parts having the
same effect are designated by the same reference numerals as in
FIG. 1, the letter a, b, etc., being added to the relevant
reference numeral.
[0034] The grinding tool of FIG. 2 differs from the preceding
grinding tool in that a cylindrical grinding head 7a is provided
instead of a conical grinding head 7. A marginal surface 14 of a
workpiece 19a can be machined by means of this tool.
[0035] This grinding tool can also be reliably guided at a high
contact pressure, a component of the contact pressure that is
perpendicular to the plate surface of the workpiece 19a providing
for the stability of the rotation axis of the grinding head without
tilting, and a component that is parallel to the plate surface
provides for the desired material removal.
[0036] A manual grinding tool shown in FIG. 3 and having a housing
1b has a disk-shaped grinding head 7b. Attached to a housing
extension 5b as a component of a guide device 8b is a carrier 10,
which is connected to a first stop element 11 and a second stop
element 12. The stop elements 11 and 12 act on opposite sides on a
workpiece 19b in a rolling manner via rotatably mounted balls
26.
[0037] The stop element 12 can be adjusted by means of a lockable
setscrew 21 for adaptation to different workpiece plate
thicknesses. Furthermore, the stop element 12 has an extension arm
22 having a stop roller 23. A tapered surface 24 of the stop roller
23 can be placed against a marginal surface 14b of the workpiece
19b.
[0038] By means of the guide device 8b, the grinding tool can be
kept at a desired angle with respect to the plate surfaces of the
workpiece 19b in a stable manner without tilting. By movement of
the tool perpendicularly to the paper plane, a bevel can be ground
on an edge 20b of the workpiece 19b by means of the tool, the
grinding tool being tilted relative to the position shown in FIG.
3, so that the grinding wheel 7b is at an angle to the edge 20b in
the feed direction.
[0039] In the exemplary embodiment in FIG. 4, the grinding is
effected in such a tilted position that the grinding generating
line of a conical grinding head 7c runs parallel to a workpiece
edge 20c.
[0040] In the exemplary embodiment of FIG. 5, a guide device 8d is
designed in a similar manner to the embodiments according to FIGS.
3 and 4. However, the entire guide device 8d is rotatable about an
axis 25 and can be locked in desired rotary positions.
[0041] A stop element 12d can be pivoted about an axis 27 by means
of levers 26. The levers 26 are attached to fork legs 28, between
which a grinding head 7d is arranged, which engages in a recess in
a stop element 11d.
[0042] In the stop position, shown in FIG. 5, of the stop element
12d, the levers 26 engage in a guide 29 in the relevant fork leg
28, as a result of which rotation of the stop element 12d about the
axis 27 is blocked. In this position, the force of a disk spring 30
acts on the stop element 12d. The contact pressure can be adjusted
by the helical spring 30 by means of a knurled nut 31.
[0043] By means of the tool shown in FIG. 5, bevels 20d can be
ground at different angles on workpieces 19d depending on the
pivoted position of the guide device 8d.
[0044] A manual grinding tool shown in FIG. 6 has a guide device 8e
which is intended for placing against a flat surface 32 of a
workpiece 19e.
[0045] The guide device 8e consists of a support plate 33 which is
connected to a housing extension Se of the grinding tool and from
which stop elements 34 and 35 in the form of elongated supporting
feet of different height project. A grinding head 7e having a
conical grinding surface is arranged between the stop elements 34
and 35, which are provided with rollers 36. The difference in
height between the stop elements 34, 35 is dimensioned in such a
way that the respective generating line, nearest to the workpiece
19e, of the conical grinding surface 7e runs parallel to the
surface 32.
[0046] The grinding head 7e could be displaceable with respect to
the rest of the tool and could be acted upon by a spring in such a
way that the contact pressure of the grinding head against the
workpiece is increased by increasing the contact pressure of the
tool against the surface 32.
[0047] A weld 37 projecting from the surface 32 can advantageously
be ground off by means of the tool of FIG. 6, the guide device 8e
guiding the grinding head 7e parallel to the surface 32. In
addition, the rollers 36 provide for linear guidance along the weld
37.
[0048] A grinding tool shown in FIG. 7 and comprising a grinding
head 7f has a guide device 8f with two rollers 38 and 39. The
rollers are attached at one end to a support plate 40 which is
perpendicular to the roller axis and which in turn is connected to
a holder 41 which can be pivoted about an axis 25f and can be
locked in desired pivoted positions. The holder 41 can be varied in
its length for adjusting the grinding point.
[0049] The end edge of a tubular workpiece 42 can be machined with
the tool, the rollers 38 and 39 of the guide device 8f rolling on
the outer or inner lateral surface of the pipe length, while the
support plate 40 bears against the end of the pipe length. The
bevel angle to be ground can be set by pivoting the guide device
8f, and the grinding, point at the conical grinding surface of the
grinding head 7f can be varied by adjusting the length of the
holder 41.
[0050] The workpiece 42 has sufficient play between the rollers 38
and 39 in order to be able to pivot the tool for varying the infeed
and thus the removal depth.
[0051] Instead of two rollers, four rollers could also be attached
to the support plate, and the grinding head could be displaceable
relative to the support plate for varying the infeed.
[0052] In an exemplary embodiment shown in FIG. 8, a drive shaft
18g for a grinding head 7g is connected to gearing 51 via a driving
belt 50. A gear 52 attached to the gearing 51 on the output side
meshes with a gear 53 which is connected to a bush part 9g. The
bush part 9g is rotatably mounted at 54 on a housing extension 5g.
A further bush part 55 arranged between the bush part 9g and the
housing extension 5g and connected to an annular stop 8g has a
curved annular groove 56, in which a cam 57 projecting inward from
the bush part 9g engages. Lugs 59 projecting inward from the bush
part 55 engage in longitudinal grooves 60 in the housing extension
5g, with an anti-rotation locking means being formed.
[0053] The gearing 51 reduces the speed of the drive shaft 18g to a
few revolutions per minute. The cam 57 of the bush part 9g driven
via the gears 52 and 53 displaces the further bush part 55 axially
according to arrow 58, so that the annular stop 8g performs an
oscillating movement.
* * * * *