U.S. patent application number 10/852366 was filed with the patent office on 2005-03-17 for hand-held grinding tool with replaceable grinding-plate part.
Invention is credited to Madsen, Michael Gramstrup, Nielsen, Svend Jonny.
Application Number | 20050059328 10/852366 |
Document ID | / |
Family ID | 34259067 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050059328 |
Kind Code |
A1 |
Madsen, Michael Gramstrup ;
et al. |
March 17, 2005 |
Hand-held grinding tool with replaceable grinding-plate part
Abstract
There is described a hand-held grinding tool with a replaceable
grinding-plate part, preferably comprising a steel plate, where on
a grinding surface there is applied an abrasive coating in the form
of grains of hard metal, which is preferably secured by soldering,
the hand tool further comprising a handling part and clamping means
for clamping the grinding-plate part to the handling part in a
replaceable manner.
Inventors: |
Madsen, Michael Gramstrup;
(Guangzhou, CN) ; Nielsen, Svend Jonny; (Stovring,
DK) |
Correspondence
Address: |
CANTOR COLBURN, LLP
55 GRIFFIN ROAD SOUTH
BLOOMFIELD
CT
06002
|
Family ID: |
34259067 |
Appl. No.: |
10/852366 |
Filed: |
May 24, 2004 |
Current U.S.
Class: |
451/523 ;
451/524; 451/525 |
Current CPC
Class: |
B24D 15/02 20130101 |
Class at
Publication: |
451/523 ;
451/524; 451/525 |
International
Class: |
B24B 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2003 |
DK |
2003 00149 |
Claims
1. Hand-held tool for the grinding of surfaces, said tool
comprising: a handling part, a grinding-plate part which comprises
a metal plate with a grinding surface having an abrasive coating,
and clamping means for clamping the grinding-plate part to the
handling part in a replaceable manner.
2. Hand-held grinding tool according to claim 1, wherein the
clamping means comprise an operating element for fastening and
loosening the grinding-plate part to/from, respectively, the
handling part and wherein the operating element is arranged to be
operated manually from a side of the hand tool which faces
substantially away from the grinding surface.
3. Hand tool according to claim 1, wherein the grinding-plate part
comprises at least one opening in which internal threads are formed
for co-operation with the clamping means.
4. Hand tool according to claim 1, wherein the grinding-plate part
on a side opposite to the grinding surface comprises an engagement
part for co-operation with the clamping means.
5. Hand tool according to claim 2, wherein the grinding-plate part
further comprises at least two plate parts which extend at a first
distance away from the grinding surface and substantially parallel
with two opposing edges of said surface and said plate parts are
arranged to co-operate with the clamping means.
6. Hand tool according to claim 2, wherein the clamping means
comprise a clamping part which, by operation of the operating
element, clamps said plate parts firmly between the clamping part
and a contact surface of the hand tool.
7. Hand tool according to claim 1, wherein the metal plate at least
at one edge of the grinding surface comprises a side grinding
surface with an abrasive coating, said side grinding surface
extending substantially at right-angles to the grinding surface, so
that the side grinding surface and the grinding surface form an
external corner.
8. Hand tool according to claim 1, which further comprises a
spacing piece arranged in a replaceable manner between the handling
part and a rear of the grinding surface.
9. Grinding-plate part comprising a metal plate with a grinding
surface with abrasive coating, said grinding-plate part being
configured to form part of a hand-held grinding tool according to
claim 1.
10. Grinding-plate part according to claim 9, wherein the metal
plate at least at one edge of the grinding surface comprises a side
grinding surface with an abrasive coating, said side grinding
surface extending substantially at right-angles to the grinding
surface, so that the side grinding surface and the grinding surface
form an external corner.
11. Grinding-plate part according to claim 9, further comprising at
least one opening in which an internal thread is formed for
co-operation with the clamping means.
12. Grinding-plate part according to claim 9, wherein a side
opposite of the grinding surface comprises an engagement part for
co-operation with the hand tool's clamping means.
13. Grinding-plate part according to claim 9, wherein the
grinding-plate part further comprises at least two plate parts
which extend at a first distance away from the grinding surface and
substantially parallel with two opposing edges of said surface,
wherein said plate parts are arranged to co-operate with the hand
tool's clamping means.
14. Hand-held tool for the grinding of surfaces, said tool
comprising: a handling part comprising a handgrip, a grinding-plate
part which comprises a metal plate with a grinding surface having
an abrasive coating, wherein an opening for mounting of a shaft is
provided in said handgrip.
15. Hand tool according to claim 14, wherein a mounting part is
provided within said opening, the mounting part comprising a length
of a profile of a C-shaped cross-section and a slide part provided
therein, the slide part having a through-hole provided with an
internal thread.
16. Hand tool according to any of claim 14, further comprising
clamping means for clamping the grinding-plate to the handling part
in a replaceable manner.
17. Hand tool according to claim 1, wherein the metal plate is a
steel plate.
18. Hand tool according to claim 14, wherein the metal plate is a
steel plate.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a hand-held grinding tool
with a replaceable grinding-plate part, preferably comprising a
steel plate, where on a grinding surface there is laid an abrasive
coating in the form of grains of hard metal, which are preferably
secured by soldering.
[0002] The grinding tool according to the invention is intended for
grinding by hand, i.e. without a motor-driven movement of the
grinding surface, and is preferably configured in a light
construction of plastic, aluminum, wood or the like. The tool can
be configured with or without a handgrip, and can be provided with
an arrangement for the mounting of a shaft for upright
grinding.
BACKGROUND OF THE INVENTION
[0003] The soldering of hard metal grains on steel is a known
technique and is used, among other things, for rotating grinding
tools in both trade and industry. There are also produced smaller
hand tools with hard metal grains such as files, hand-held sanding
pads and grinding boards of steel. Sanding pads with a replaceable
steel sanding plate with hard metal grids are also known, in which
the sanding plate is fastened to the body part by means of
hook-and-loop fastener, such as Velcro. However, such fastening can
only take up a magnitude of the transverse stresses during use of
the tool limited by the ability to be separated again manually.
[0004] Known hand-held grinding tools with hard-metal grains have
hitherto been produced in steel plate of 2-3 mm thickness, where
the grains are soldered directly on to the supporting part of the
construction, and in a size of 200-250 cm.sup.2 with welded-on or
secured handgrip. Alternatively, as described in EP-A-1 260 317,
which is incorporated herein by reference in its entirety, use is
made of a thin steel plate of less than 2 mm, e.g. between 0.1 and
1 mm, which is secured to one or more layers of another lighter
material, e.g. by soldering, brazing, gluing or welding, in the
formation of a composite structure. As starting point, the known
hand-held grinding tools are preferably produced for the flooring
trade for the grinding of the edges of smaller floor areas, where
due to the working position the weight is of no great significance,
in that the weight of the tool does not have to be borne by the
user during the use of the tool. Although hand-held grinding tools
with hard-metal grain secured to a steel plate have a relatively
long life, i.e. that they retain their grinding characteristics
even with long-term use, there is a quite large turnover of such
tools during a building process, the reason being that the tools
are discarded when they are worn down. Therefore, the costs
involved in procuring such tools constitute operational expenses
for the building process.
[0005] Other known hand-held grinding tools for similar
applications consist of a traditional float on which sandpaper or
emery cloth is mounted by means of pins, screws or spring-loaded
clips. However, sandpaper is outdated since the grinding effect is
limited and because sandpaper, where it can be used, has a short
life with many changes as a consequence.
[0006] Particularly in the building trade, due to the use of many
new materials there is an increasing demand for being able to
adjust and grind the building elements and the materials in
general, such as glass fibers, epoxy, paint, lacquer, fillers etc.,
but also known materials such as plaster and bricked or molded
walls.
[0007] The known selection of materials in the production of tools
with a strong self-supporting steel plate results in high weight,
and herewith a limitation in the sizes of grinding pads which can
be used in practice. This is solved partly by the earlier-mentioned
tool with a plate of composite structure which, however, is more
expensive to purchase, whereby the operational costs are
increased.
BRIEF SUMMARY OF THE INVENTION
[0008] With the invention, it is desired to provide a hand-held
grinding tool which utilizes the grinding characteristics and long
life of the hard-metal coating, at the same time that a light and
user-friendly hand-held tool is made possible with limited
operational costs involved in the use thereof.
[0009] This is achieved with the hand-held grinding tool according
to the present invention, where said tool comprises a handling
part, a grinding-plate part, which comprises a metal plate,
preferably a steel plate with grinding surface with abrasive
coating, and clamping means for clamping of the grinding plate part
to the handling part in a replaceable manner.
[0010] By including clamping means which permit a replacement of
the grinding plate part and a strong mounting of the grinding-plate
part, it is made possible that the handling part, which is
preferably made of a lighter material than the grinding-plate part,
can be reused with a new grinding-plate part, whereby the
operational costs involved in the use of the grinding tool are
considerably reduced in relation to tools where the whole of the
tool is discarded when the grinding characteristics of the grinding
plate have been worn down. Moreover, the amount of wastage from the
building process is reduced. The same handling part can function as
a standard part which can be used with different types of
grinding-plate parts with different grain sizes and grain types,
with or without grinding edges at right angles to the
grinding-plate etc.
[0011] It is especially preferred that the grinding tool's clamping
means comprise an operating element for fastening the
grinding-plate part to, respectively loosening the grinding-plate
part from the handling part, inasmuch as the operating element is
arranged to be operated manually from that side of the grinding
tool which faces substantially away from the grinding surface. It
is hereby achieved that the grinding-plate part can be placed on a
horizontal surface, such as a floor or a table, while the handling
part is mounted on the tool by means of the clamping means, whereby
a comfortable work position as well as an easy and precise mounting
is achieved.
[0012] The present invention relates to a hand-held tool for the
grinding of surfaces, said tool comprising a handling part, a
grinding-plate part which comprises a metal plate, preferably a
steel plate, with grinding surface with abrasive coating, and
clamping means for replaceable clamping of the grinding-plate part
to the handling part.
[0013] Preferably, the grinding surface is substantially plane, but
can within the scope of the invention also have a curved surface,
such as a single or double-curve grinding surface. The
circumferential extent of the grinding surface can be configured so
that it corresponds to an envisaged application, but it is
generally preferred that use is made of a rectangular grinding
surface, preferably with a size of 40-300 mm in width and 50-1000
mm in length.
[0014] The abrasive coating comprises preferably hard-metal grains
which are fastened on the metal plate. The fastening is preferably
effected by soldering of the grains on the metal plate, but also
brazing, welding and gluing are among the methods which can be used
for fastening the grains to the metal plate.
[0015] A special aspect is that the hand-held grinding tool's
clamping means can comprise an operating element for fastening
respectively loosening the grinding-plate part to/from the handling
part, inasmuch as the operating element is arranged to be operated
manually from that side of the tool which faces substantially away
from the grinding surface. These clamping means can preferably
comprise threaded rods which are either screwed down into
corresponding holes with internal threads in the grinding-plate
part itself, or which pass through a clamping part of the handling
part and down into corresponding holes with internal threads in the
handling part, where a part of the grinding-plate part arranged for
this purpose is clamped firmly between the clamping part and a
contact part of the handling part. The operating element can, for
example, be a wing screw or other arrangement for direct manual
operation, but it can also be an internal slot or external contact
surfaces on the head of a threaded rod for engagement with a tool,
e.g. a screwdriver or a key. Other clamping means can also be used,
such as clips or eccentric cams which, by turning with an operating
element, firmly clamp a part of the grinding-plate part.
[0016] For co-operation with the hand tool's grinding-plate part,
the clamping means can comprise an engagement part which is secured
to the rear of the grinding surface, such as e.g. a bush with an
internal thread.
[0017] A particularly suitable grinding-plate part further
comprises two plate parts which extend at a first distance away
from the grinding surface and substantially parallel with two
opposite edges of said surface, inasmuch as the plate parts are
arranged to co-operate with the clamping means. These two or more
plate parts are particularly suitable for being clamped firmly by
e.g. a clamping part, which by operation of the operating element
clamp the plate parts between the clamping part and a contact
surface of the hand tool, and are preferably extending in a plane
substantially parallel to the plane of the grinding surface. This
type of tools according to the invention and having a clamping part
for clamping such plate parts against a contact surface have
preferably of larger grinding surface area of e.g. 150 to 3000
cm.sup.2, preferably of 200 to 800 cm.sup.2 with e.g. a rectangular
shape of 80 to 300 mm in width and 150 to 1000 mm in length,
preferably of 100 to 200 mm in width and 200 to 800 mm in
length.
[0018] The grinding-plate part's metal plate can at least one edge
of the grinding surface comprise a side grinding surface with an
abrasive coating, said side grinding surface extending
substantially at right-angles to the grinding surface, so that the
side grinding surface and the grinding surface form an external
corner. These two grinding surfaces can hereby be used for
simultaneous grinding or processing of two material surfaces which
form an internal corner.
[0019] In order to achieve flexibility in the height of the side
grinding surfaces, the tool can also comprise a spacing piece which
is arranged in a replaceable manner between the handling part and
the rear of the grinding surface.
[0020] The invention also relates to grinding-plate parts which are
configured to form part of the hand-held tool according to the
invention.
[0021] Furthermore, the present invention relates to a hand-held
tool, such as the one previously described, optionally with any of
the various technical features disclosed, for the grinding of
surfaces, said tool comprising a handling part comprising a
handgrip, a grinding-plate part which comprises a metal plate,
preferably a steel plate, with a grinding surface having an
abrasive coating, wherein an opening for mounting of a shaft is
provided in said handgrip. The opening is so arranged, that the
handgrip may be used for manual operation of the tool without being
hindered or impeded by the opening. A mounting part may provided
within said opening, preferably so that it substantially is fully
accommodated within the opening, the mounting part comprising a
length of a profile of a C-shaped cross-section and a slide part
provided therein, the slide part having a through-hole provided
with an internal thread. Thereby, the point of attack of the forces
from the shaft on the tool may be varied.
BRIEF DESCRIPTION OF THE DRAWING
[0022] Preferred embodiments of the invention are shown as examples
hereof in the accompanying drawing, where
[0023] FIG. 1 shows a first embodiment seen in perspective,
[0024] FIG. 2 shows an exploded view in perspective of the
embodiment in FIG. 1,
[0025] FIG. 3 shows a second embodiment seen in perspective,
[0026] FIG. 4 shows an exploded view in perspective of the
embodiment in FIG. 3,
[0027] FIG. 5 shows a third embodiment seen in perspective,
[0028] FIG. 6 shows the embodiment in FIG. 5 in the opened
state,
[0029] FIG. 7 shows an exploded view in perspective of the
embodiment in FIG. 5, and
[0030] FIG. 8 shows the embodiment in FIG. 5 seen in perspective,
where the mounting of a shaft on the tool is shown.
DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION
[0031] A first embodiment of the invention is shown in FIGS. 1 and
2, and is a hand-held grinding tool 1 which comprises of a
rectangular handling part 2 which is provided with a handgrip 3 for
direct manual use of the tool 1, and an opening 4 with internal
thread for mounting of a swivel 5 or universal joint 5 which is
used for mounting a shaft on the tool. The handling part 2 has four
openings 6 with internal threads disposed in a recess 7 in the edge
of the handling part 2. A mounting frame 8 has corresponding
openings 9 without internal threads, and can be clamped to the
handling part 2 by means of four screws 10 with a head with slot,
e.g. a wide straight slot, which is easy to clean before it is
operated with a screwdriver. When the screws 10 are tightened, the
mounting frame 8 functions as a clamping part which clamps the
plate parts 11, 12, 17 of the grinding-plate part 13, which extend
parallel with the grinding sole of the grinding-plate part 13,
between the mounting frame 8 and a contact surface 14, which is
formed by the recess 7 in the handling part 2. The grinding-plate
part 13 is hereby clamped to the handling part.
[0032] The grinding-plate part 13 is a steel plate, on one side of
which there is soldered hard-metal grains, so that a surface with
abrasive coating is created. The grinding sole, of which only the
rear 15 can be seen directly in the figures, is rectangular in
shape and extends as a plane surface. At the two long edges of the
grinding sole, and at the one short edge, the steel plate is bent
upwards so that a side grinding surface 16 is formed. At a given
height H, the steel plate is bent again so that three plate parts
11, 12, 17 are formed which extend parallel with the grinding sole,
and which are suitable for co-operation with the mounting frame 8
and the contact surface 14 of the recess 7 for clamping of the
grinding-plate part 13 to the handling part 2. Between the
grinding-plate part 13 and the handling part 2 there is placed a
spacing piece 18 with a height of e.g. 5-50 mm, which is secured to
the handling part 2 in a removable manner with two screws 19. The
rear 15 of the grinding sole is supported by the distance piece 18,
which can be changed so that the tool 1 can be adapted for use with
different grinding-plate parts 13 with vertical side grinding
surfaces 16 of different heights H.
[0033] When the abrasive coating on the grinding-plate part 13 is
worn down or needs to be replaced for other reasons, the four
screws 10 which hold the mounting frame 8 are loosened and the
grinding-plate part can be slid out towards the one short end of
the grinding-plate part 13. Thereafter, a new grinding-plate part
13 can be pushed in and secured by tightening the four screws 10.
In cases where the new grinding-plate part 13 has a side grinding
surface 16 of a height H different to that of the old
grinding-plate 13, the distance piece 18 is dismounted and a new
distance piece 18 of suitable thickness is mounted on the handling
part 2 before the new grinding-plate part 13 is slid in.
[0034] In an alternative to the first embodiment, use is not made
of a mounting frame 8, and instead the edges 11, 12, 17 of the
grinding-plate part 13 are provided with holes which the screws 10
pass through for the clamping of the grinding-plate part 13 to the
handling part 2.
[0035] A second embodiment of the invention is shown in FIGS. 3 and
4, and is a hand-held sanding block 101 which comprises a handling
part 102 with a through-going opening 120 and a circular recess 121
in the upper surface 122 of the handling part 102, so that space is
formed for the housing of a clamping element in the form of a screw
123 with a head 124, in which head 124 there is provided a wing 125
for manual operation of the screw 123. The head 124 of the screw
123 passes down in the recess 121, so that when the screw 123 is
mounted, the upper side 126 of the head 124 forms part of a plane
which is formed by the upper surface 122 of the handling part 102.
The threaded part 127 of the screw 123 extends through the handling
part 102 and engages with a bush 128 which is provided with an
internal thread and is soldered on the rear 115. of a
grinding-plate part 113. The grinding-plate part 113 has bent-up
edges which form side grinding surfaces 116 along all four edges of
the rectangular grinding plate part 113. The handling part 102 is
provided with a recess 129 on its lowermost edge, and the four side
grinding surfaces 116 fit into this recess 129.
[0036] A third embodiment of the invention is a hand-held grinding
tool 210 as shown in FIGS. 5-8, where the mounting frame 208 is
connected to the handling part 202 by a hinge 230 along one of the
narrow edges of the handling part 202. Close to the other end of
the handling part 202 there is placed two clamping parts 231 which
are pivotally secured to the handling part 202 around a vertical
axis, and which comprises a head 232 with a wing 233 which, by the
turning of the part 231, enters into engagement with an inclined
recess 234 in the mounting frame 208, so that the mounting frame
202 is clamped down against a contact surface 214 of the handling
part 202, whereby the grinding-plate part 213 is held firmly on the
handling part 202. The clamping parts 231 can be turned manually by
the user gripping around the head 232 and the wing 233 with his/her
fingers or with pliers, but can also be turned using a tool which
fits down in the slot 236 which is formed in the heads 232 of the
clamping parts 231. With the turning of the clamping parts 231
during the clamping of a grinding-plate part 213, the angular
extent of the turn is limited by a stop 235 which the wing 233
abuts against when it stands in the optimal clamping position.
[0037] The grinding-plate part 213 has three plate parts 211, 212,
217 which extend parallel with the grinding sole of the
grinding-plate part 213, and in which there are punched elongated
holes 237 which fit together with conical projections 238 on the
mounting frame 208 and elongated depressions 239 in the contact
surface 214 of the handling part 202. For the changing of a
grinding-plate part 213, the wings 233 of the clamping parts 231
are turned away from the stops 235, so that the wings 231 stand in
a position as shown in FIG. 6, where the mounting frame 208 can be
opened and the grinding-plate part 213 can be pushed out from the
handling part 202. A new grinding-plate part 213 is mounted by
being pushed in over the handling part 202, after which the
mounting frame 202 is closed. The projections 238 are hereby
pressed down through the punched-out holes 237 and into the
depressions 239. The effect of the conical configuration of the
projections 238 is partly that the punched-out holes 237 are
secured precisely in the correct position, and. partly that the
plate parts 211, 212, 217 are clamped down against the contact
surface 214 of the handling part 202.
[0038] In the exploded view in FIG. 7 it is seen that this
embodiment can comprise a spacing piece 218, so that the tool 201
can be adapted for use of grinding-plate parts 213 with vertical
side surfaces 216 of different heights H.
[0039] As shown in FIGS. 7 and 8, a shaft 240 can be mounted on the
hand tool 201 by means of a mounting part 241 which is placed in a
cutout 242 in the side of the molded handgrip 203 and is secured
with screws 243. The mounting part 241 is a profile with a C-shaped
cross-section in which a slide part 244 can be displaced along the
mounting part 241. The securing part 245 for the shaft 240 has an
opening 246 through which a bolt 247 with an operating wing 248 can
pass. On the other side of the clamping part 245, the bolt 247
passes through a spacing piece 249 which lies up against the outer
side of the mounting part 241, and the threaded part 250 of the
bolt 247 enters into engagement with a corresponding internal
thread in a through-going opening 251 in the slide part 244. When
the bolt is tightened, the outer end of the threaded part 250 will
abut up against the inner side of the mounting part 241, while the
slide part will be pressed the opposite way in the profile, and
this effect will lock the bolt 247 in position. The securing part
245 can turn freely around the bolt 247, which is decisive for the
use of the tool 201 with the shaft 240.
[0040] While the invention has been described with reference to an
exemplary embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *