U.S. patent application number 10/475177 was filed with the patent office on 2004-09-02 for saw blade sharpening machine.
Invention is credited to Turnac, Andree, Wagner, Roland, Wimble, Gary.
Application Number | 20040171334 10/475177 |
Document ID | / |
Family ID | 7681900 |
Filed Date | 2004-09-02 |
United States Patent
Application |
20040171334 |
Kind Code |
A1 |
Turnac, Andree ; et
al. |
September 2, 2004 |
Saw blade sharpening machine
Abstract
A grinding machine is designed as a multi-station grinding
machine, which has two complete grinding stations. The grinding
stations have grinding heads, which can be moved by means of
appropriate positioning devices, for example compound table
arrangements, and/or pivot tables, in relation to the saw blade.
Positioning devices and arresting devices for the workpiece are
furthermore parts of the grinding stations. The workpiece support
is used for positioning the saw blades to the extent that their
center axis is to be fixed in the grinding. The rotation of the saw
blades around this center axis M, and the clamping in place of the
saw blade in the respective rotated position for performing the
grinding operation is the task of the respective units in the
grinding stations. A very rapid and precise, and therefore
cost-effective, processing of saw blades is possible by means of a
grinding machine designed in this way. The grinding machine is
particularly suited for sharpening saw blades in the course of
their manufacture.
Inventors: |
Turnac, Andree; (Eutingen,
DE) ; Wagner, Roland; (Burladingen, DE) ;
Wimble, Gary; (Locust Grove, VA) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
7681900 |
Appl. No.: |
10/475177 |
Filed: |
April 19, 2004 |
PCT Filed: |
April 9, 2002 |
PCT NO: |
PCT/DE02/01297 |
Current U.S.
Class: |
451/65 ;
451/45 |
Current CPC
Class: |
B23D 63/123 20130101;
B23D 63/14 20130101 |
Class at
Publication: |
451/065 ;
451/045 |
International
Class: |
B24B 001/00; B24B
007/19 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2001 |
DE |
101 19 084.0 |
Claims
1. A grinding machine (1), in particular for saw blades (2), having
a workpiece support (14) arranged for the simultaneous reception of
several identical workpieces (2), a positioning unit (19) connected
with the workpiece support (14), which is used to move the
workpiece support (14) in steps and to maintain it in preselected
positions, at least two grinding stations (11, 12), each of which
has at least a. a grinding device (41, 42) for processing at least
one surface (5, 6, 7) of the workpiece (2) which is fixed in place,
b. a positioning device (51, 52) for positioning the workpiece (2)
in the processing station (11, 12), and c. an arresting device (53,
54) for the temporary clamping of the workpiece (2) in the
processing station (11, 12).
2. The grinding machine in accordance with claim 1, characterized
in that each processing station (11, 12) is equipped to process
only one surface (5), or only one group of surfaces (6, 7), of all
sawteeth (3) of the saw blade (2) located in the processing
station.
3. The grinding machine in accordance with claim 1, characterized
in that the grinding device (41) has a grinding head (37) which is
designed for processing one surface of a sawtooth (3).
4. The grinding machine in accordance with claim 3, characterized
in that the grinding head (37) is equipped for processing a tooth
surface constituting a tooth back (5).
5. The grinding machine in accordance with claim 1, characterized
in that the grinding device (42) has at least one grinding head
(38, 39), which is equipped for processing two tooth surfaces which
are located opposite each other, and that these tooth surfaces
constitute tooth flanks (6, 7).
6. The grinding machine in accordance with claim 5, characterized
in that the grinding heads (38, 39) can be simultaneously brought
into engagement with the sawtooth (3).
7. The grinding machine in accordance with claim 1, characterized
in that each grinding station (11, 12) has a frame (31, 32) which
supports the grinding device (41), the positioning device (51, 52)
and the arresting device (53, 54).
8. The grinding machine in accordance with claim 7, characterized
in that the grinding machine (1) has a base frame (48), which
supports the frames (31, 32) of the grinding stations (11, 12), and
the positioning unit (19) for the workpiece support (14).
9. The grinding machine in accordance with claim 1, characterized
in that the grinding stations (11, 12) are arranged and designed in
such a way that their grinding devices (37, 38, 39) can be
simultaneously operated.
10. The grinding machine in accordance with claim 1, characterized
in that the grinding head (37, 38, 39), as well as positioning,
guidance and displacement devices (33, 35, 34, 36), are part of the
grinding devices (41, 42) in order to move each respective grinding
head (37, 38, 39) in at least three spatial directions (X, Y, Z),
which extend at right angles to each other, and in a pivot
direction (B), which is aligned parallel with the axis of rotation
of the saw blade (2).
11. The grinding machine in accordance with claim 1, characterized
in that the workpiece support (14) has receivers (21) for the
freely rotatable seating of the saw blades (2).
12. The grinding machine in accordance with claim 11, characterized
in that the workpiece support (14) is embodied with three or more
arms, and has at least one receiver (21) on each arm (15, 16,
17).
13. The grinding machine in accordance with claim 11, characterized
in that the receiver (21) is formed by a mandrel (22), whose radial
distance in relation to the axis of rotation (18) of the workpiece
support (14) is arranged to be adjustable.
14. The grinding machine in accordance with claim 13, characterized
in that several predetermined positions are assigned. to each
mandrel.
Description
[0001] The invention relates to a grinding machine, in particular
for sharpening saw blades in the course of their manufacture.
[0002] Saw blade sharpening machines are known which have one or
several grinding heads, by means of which the teeth of a saw blade
are to be brought into the desired shape. It is known that several
grinding heads are required or used for this. For example, grinding
heads are known which have a first grinding disk, for example for
the tooth back, and a second grinding disk, for example for the
tooth face. It is then necessary to process, for example, first the
tooth back and then the tooth face of a saw blade tooth by tooth.
The saw blade is rotated on by exactly one tooth after each
grinding process of a tooth by means of an appropriate positioning
device. The time required for processing the saw blade then is the
time required for two circulations of the saw blade. This can be
shortened, if separate grinding heads are provided for the tooth
face and the tooth back. However, this has the disadvantage that it
is necessary to match the working of both grinding heads exactly,
i.e. to synchronize them. When the saw blade is moved on, both
grinding heads must be out of engagement with the respective
tooth.
[0003] Based on this it is the object of the invention to create a
saw blade sharpening machine which is suitable for generating a
large output, in particular regarding production.
[0004] The grinding machine in accordance with the invention has a
workpiece support which is arranged for the simultaneous reception
of several identical workpieces, in particular saw blades. The
workpiece support can be moved by means of a positioning unit in
such a way that a received workpiece (saw blade) sequentially
passes through at least two grinding stations. At least one
grinding device, one positioning device and one arresting device
are provided in each grinding station. The positioning device and
the arresting device, which are used for the stepped rotation of
the saw blade or other workpiece, as well as for clamping it in
place in the processing position, are assigned to the respective
grinding station. Therefore the positioning and clamping of the
workpiece (saw blade) is a task of the respective grinding station.
By means of this it is possible to attain high clock rates without
the grinding stations interfering with each other.
[0005] Only one grinding device operates at any given time on each
saw blade. It is therefore not necessary to synchronize the
grinding processes on different surfaces of the individual teeth.
Only the total processing time in each processing station must be
synchronized, so that the workpiece support as a whole is moved on
when each of the two processing stations is finished. But it is
possible to let both grinding stations operate unsynchronized with
each other. This provides the option, for example in connection
with saw blades with offset teeth, to process the right and left
flank alternatingly, but also every tooth back.
[0006] The positioning and the arresting device for the workpieces
takes place by means of the grinding station. This has the further
advantage that the accuracy of the result of the work depends only
to a slight degree on the accuracy of the position of the workpiece
support. A high manufacturing quality can be achieved in a simple
and cost-effective manner.
[0007] In addition, it is possible to minimize nonproductive time
by means of the grinding machine in accordance with the invention.
This is successful if every grinding station is assigned the
processing of only one surface, or group of surfaces of all
sawteeth. For example, one grinding station can be equipped to
process the tooth back, and the other grinding station to process
the tooth flanks. In many cases it is possible to omit processing
the tooth face.
[0008] If each of the grinding heads only needs to process one
surface, or group of surfaces, the movements of the grinding heads
can be reduced to merely feed motions. Position changes, such as
are required when one grinding head is intended to process a tooth
face, as well as tooth backs, or tooth backs and tooth flanks, can
be avoided. This has a time-saving effect.
[0009] With the above mentioned concept, one grinding station
processes only the tooth backs of a saw blade, for example, while
the other grinding station only processes the tooth flanks, for
example. In comparison with grinding machines in which processing
of the tooth flanks and the tooth backs of the same saw blade takes
place simultaneously, it is possible to even increase the
output.
[0010] Processing of the respective tooth surfaces is preferably
performed with only one grinding head which contains only one
rotary driven grinding disk. The shape of the grinding disk is
arranged to correspond to the shape of the surface to be processed.
To this extent the grinding head is preferably specialized,
position changes, and therefore corresponding positioning times,
such as they were common with grinding heads having several
grinding bodies, are in principle avoided.
[0011] If necessary, a grinding head can also be provided with a
grinding finger, for example for creating a hollow face.
[0012] A twin grinding head can also be provided, in particular for
processing tooth flanks. It is preferably designed in such a way
that two driven grinding bodies (grinding disks) can be
simultaneously brought into engagement with the oppositely located
flanks of one tooth. A considerable advantage of this step lies in
that the tooth flanks of a saw blade can be ground in one passage
of all teeth of the saw blade, so that the same grinding time
results as a whole, as that used for processing the tooth backs in
the other grinding machine. Two grinding heads, which can be moved
(away from and toward each other), are part of the twin grinding
head, one of which is for example located above, and the other for
example below the saw blade. The relative movement of the grinding
heads in respect to each other can be achieved by means of linear
guide devices and corresponding drive mechanisms, for example.
Displacement of the grinding heads in the radial direction of the
saw blade can be accomplished by the displacement of a common
support. The same applies for the circumferential direction and
possible pivoting movements.
[0013] The grinding machine in accordance with the invention is
suitable for sharpening saw blades with hard alloy inserts,
particularly in its embodiments with twin grinding heads in one
processing station. To produce saw blades equipped with hard alloy
it is possible to provide a soldering station in place of or in
addition to a grinding station, which is used for providing the saw
blades with hard alloy bodies on the teeth.
[0014] In connection with the grinding machine of the invention,
the grinding stations are not only assigned the processing of the
workpiece, but also its positioning. But the workpiece support is
merely used for conveying the workpieces from one grinding station
to the other. Accordingly, each of the grinding stations can have
frames supporting the processing device, the positioning device and
the arresting device. The grinding machine can be provided with a
base frame which supports the positioning unit for workpiece
supports, as well as the two frames of the processing units.
Demands made on the machine frame are in this case also relatively
low in cases where it is intended to achieve a high grinding
accuracy of the workpieces (saw blades).
[0015] The grinding heads of the grinding stations are seated by
means of guidance devices and displacement devices in such a way
that they can be displaced in several directions and are preferably
also pivotable. By means of this the setting of the grinding heads
into a base position and, starting from the latter, a feed
position, is made possible, which is repeated at each sawtooth and
is required for performing the grinding process. But the assumption
of the base position is only used for the initial positioning and
set-up of the grinding station in regard to a defined saw
blade.
[0016] Preferably the saw blades are seated in a freely rotatable
manner on the workpiece supports. Appropriate receivers, for
example mandrels or the like, are used for this. The mandrels can
be provided in predetermined positions on the workpiece supports.
It is also possible to preset several positions for each mandrel to
match different saw blades to be produced. Preferably the
predetermined positions are arranged on the arms of the workpiece
support in such a way that the teeth of the respectively assigned
saw blades are positioned in the same grinding position.
[0017] Further details of advantageous embodiments of the invention
ensue from the drawings, the description or further dependent
claims.
[0018] An exemplary embodiment of the invention is illustrated in
the drawings. Shown are in:
[0019] FIG. 1, a grinding machine in accordance with the invention
in a perspective view,
[0020] FIG. 2, the grinding machine in FIG. 1 in a schematic view
from above,
[0021] FIGS. 3 and 4, a portion of a saw blade in an enlarged
perspective representation, and
[0022] FIG. 5, a workpiece support in a partial perspective plan
view.
[0023] A grinding machine 1 is illustrated in FIG. 1, which is
preferably employed for grinding saw blades 2 in the course of the
manufacturing process. The saw blades 2 are saw blades equipped
with hard alloy, as they are schematically indicated in FIGS. 3 and
4 on a different scale and in part. Each tooth 3 of the saw blade 2
is provided with a hard alloy body 4, which projects over at least
one of the flat sides of the saw blade 2 in the axial direction,
and which protrudes above the tooth in the radial direction, which
can be seen in particular in FIG. 4.
[0024] The hard alloy body 4 is substantially embodied as a cube,
wherein its radially outward pointing surface defines a tooth back
5, and its two lateral surfaces pointing in the axial direction
define tooth flanks 6, 7. With its front, the hard alloy body 4
defines a tooth face 8 on the front of the tooth 2.
[0025] Even in connection with the production of cost-efficient saw
blades it is necessary to grind the tooth back 5 and the tooth
flanks 6, 7. However, in many cases it is possible to omit grinding
the tooth face 8.
[0026] With the grinding machine 1 in accordance with the
invention, grinding of the tooth back and grinding of the tooth
flanks takes place in grinding stations 11, 12, which are separated
from each other and through which the saw blade 2 passes
sequentially. Here, a workpiece support 14 is used for transporting
the saw blades, which has three arms 15, 16, 17 arranged at equal
angular distances from each other, such as can be seen in the view
from above in FIG. 2, for example. The workpiece support 14 is
rotatably seated around a vertical axis of rotation 18. A
positioning unit 19 is used for moving the workpiece support 14 on
by respectively 120.degree. around this axis, which moves the
workpiece support 14 forward and then, during the processing of the
saw blades 2, maintains it in the position reached.
[0027] The workpiece support 14 and its arm 15 can be seen in FIG.
5. Like the other arms 16, 17, the arm 15 extends away from the
axis of rotation 18 in the radial direction. The arms 15, 16, 17
are embodied essentially flat on the top. A mandrel 22 is used for
example as a receiver for the saw blade 2, which has on its upper
end a tapering, for example conical, section 23, underneath that a
flange 24 for seating the saw blade 2, and a screw thread-equipped
shaft 25 for connecting it with the workpiece support 14. One or
several openings 26, 27 provided in the arm 15 are assigned to the
mandrel 22.
[0028] The mandrel 22 and the openings 26, 27 are oriented in such
a way that the center axis 28 of the mandrel 22 is oriented
parallel in respect to the axis of rotation 18. Therefore the saw
blades 2 are horizontally oriented in the grinding machine 1, as
seen in FIG. 1, and rest, centered by the mandrel 22 but rotatable,
on the respective receivers 21. It is also possible to provide
another receiver, which holds and seats the saw blade, instead of
the mandrel 22.
[0029] As can be seen from FIGS. 1 and 2, the processing stations
11, 12 are similarly designed. Each has a mounting, or a frame 31,
32, on which a table 33, 34 is pivotably seated. A drive mechanism,
not further represented, is assigned to the table 33, 34 in order
to be able to bring the table into a desired pivoted position.
[0030] As illustrated in FIG. 1, each table 33, 34 supports a
compound table arrangement 35, 36 which, in turn, supports one
grinding head 37, or two grinding heads 38, 39.
[0031] Together with the compound table arrangement 35, to which
drive mechanisms, not further represented, are assigned, and the
grinding head 37, the table 33 constitutes a grinding device 41.
The table 34, together with the compound table arrangement 36 and
the grinding heads 38, 39, also constitutes a grinding device
42.
[0032] The table 33 can be displaced around a vertical pivot axis
43, which is parallel with the axis of rotation 18. This axis is
also called the B axis. A first carriage of the compound table
arrangement 35 can be displaced radially in respect to this in the
Z direction. This Z carriage supports a carriage which can be
displaced transversely to it (X direction). In turn, the X carriage
supports a carriage which can be displaced in a direction parallel
with the axis of rotation 18 (Y direction). The displacement
directions X, Y, Z, as well as the B axis are used for setting up
and adjusting a desired position of the grinding head 37, as well
as for performing a feed movement of the latter. It is
alternatively possible to determine the sequence of the carriages
in a different way.
[0033] The grinding head 37 has a driven grinding disk 44, which is
designed as a grinding disk for the tooth back 5. It operates by
means of its narrow exterior circumferential surface. It axis of
rotation is oriented approximately radially in respect to the saw
blade 2 and matches the direction of the tooth back 5.
[0034] The processing station 12 is correspondingly laid out. The
table 34 is pivotable around a pivot axis 45, which is aligned
parallel with the axis of rotation 18 and is called the B axis. A
carriage can be displaced in the Z direction radially in respect to
the B axis on the table 34. In turn, the Z carriage supports a
carriage which can be displaced horizontally transversely to it in
the X direction. It is provided with two carriages (Y1, Y2), which
can be separately displaced in the Y direction, each of which
supports a grinding head 38, or 39. Each of the grinding heads 38,
39 has a grinding disk 46, 47 used for grinding the tooth flanks 6,
7. Their axes of rotation are oriented parallel with each other, as
well as approximately radially in relation to the saw blade 2.
[0035] The two frames 31, 32 are seated on a common machine frame,
or base frame 48, which also supports the positioning unit 19. A
positioning device 51, 52, as well as an arresting device 53, 54,
are respectively provided for each processing station 11, 12 on the
base frame 48, or the frames 31, 32 or, as illustrated in FIG. 1,
on the tables 33, 34. The positioning devices 51, 52 are
constructed in the same way. They are embodied as so-called
separating fingers, which have a pin 55 supported by a finger and
used for moving the individual teeth 3 of the saw blade 2 in steps.
In the course of this, the pin 55 moves in a loop-shaped path 56.
The respective separating finger operates synchronously in respect
to the grinding head 37, or the grinding heads 38, 39, in each
processing station 11, 12.
[0036] The arresting devices 53, 54 are also embodied identically
with each other. The arresting device 53 is designed as a clamping
device and is used to firmly clamp the saw blade 2 in the
processing position in such a way that its tooth 3 is maintained
fixedly and steadily during the grinding process. To accomplish
this, the arresting device 53 has two clamping jaws, which are
arranged opposite each other and extend above, or below the saw
blade 2 and come into contact with its flat sides. The lower
clamping jaw 57 is preferably stationarily arranged, while the
upper clamping jaw 58 is seated in the form of a rocker above the
lower clamping jaw 57, which can be seen in particular in FIG. 1.
An appropriate drive mechanism 58, which acts on the rear end 59
which is remote from the saw blade 2 of the upper clamping jaw 58a,
is used to firmly clamp the saw blade 2 between the facing clamping
jaws, or release it, in a controlled manner.
[0037] As FIG. 2 further shows, the processing stations 11, 12 are
arranged offset from each other by 120.degree. in respect to the
axis of rotation 18. A position arranged between them, also offset
by 120.degree., is the loading and unloading position. A loading
and unloading unit 61, whose basic principles at least can be seen
in FIG. 2, is provided on the grinding machine 1 for removing
ground saw blades from the workpiece support 14 and to place saw
blades on it which still must be ground. One or several saw blade
supports 62, to which a gripper 63 with vacuum suction devices
and/or magnets is assigned, can be part of it. The gripper can be
maintained on a carriage 64, which is seated to be linearly
displaceable and which causes the loading and unloading of the
workpiece support 14.
[0038] The grinding machine 1 so far described operates as
follows:
[0039] During operation, the gripper 63 initially places a first
saw blade 2 on the workpiece support 14 in the position shown at
the bottom in FIG. 2. The central opening finds its way onto the
mandrel 22 with restricted play, on which the saw blade 2 is
therefore seated in a freely rotatable manner. The workpiece
support 14 then rotates on by 120.degree. around the axis of
rotation 18, so that the saw blade 2 is transported into the first
processing station 11 and finds its way between the jaws of the
arresting device 53. With the pin 55 the positioning device 51,
formed by the separating fingers, now engages a first tooth space
and brings a first tooth into the processing position. Now the
arresting device 53 closes and clamps the tooth of the saw blade 2
to be processed firmly in relation to the grinding head 37. The
latter can now grind the tooth back. When this is finished, the
arresting device 53 opens and the positioning device 51 moves the
saw blade 2 forward by one tooth. In this way all tooth backs 5 of
all teeth of the saw blade 2 are processed one after the other.
[0040] When processing is finished, the workpiece support 14
rotates by 120.degree., so that the saw blade 2, whose tooth backs
5 have already been processed, finds its way into the grinding
station 12. Processing of the tooth flanks now takes place here,
again tooth after tooth. In the course of transferring the saw
blade 2 from the grinding station 11 into the grinding station 12,
the workpiece support 14 has guided a further, not yet worked saw
blade 2 into the grinding station 11. While the desired tooth
grinding is performed on the previous saw blade 2 in the processing
station 12, grinding of the tooth backs takes place in the grinding
station 11.
[0041] Both grinding stations 11, 12 operate synchronously with
each other as a whole. But the grinding times of one individual
grinding operation of a tooth in the grinding stations 11, 12 can
be different. For example, it is possible to grind all tooth backs
one after the other in the grinding station 11, while the upper
tooth flanks of only the even-numbered teeth, and the lower tooth
flanks of only the odd-numbered teeth are ground in the grinding
station 12, so that the progression of the individual saw blades 2
in the grinding stations 11 and 12 takes place at different times
and at different step lengths. However, this is not mandatory, both
stations can also operate completely synchronously.
[0042] The positioning of the saw blades 2 in the processing
stations 11, 12 is relatively independent of the exact positioning
of the workpiece support 14 because of the assignment of the
positioning device 51, 52, as well as the arresting devices 53, 54
to the respective grinding stations 11, 12. Furthermore, decoupling
of the processing of the two saw blades 2 from each other takes
place in this way. In particular, the interference with the work
process on one saw blade by the work process on another saw blade,
for example by the transmission of vibrations via the workpiece
support 14, is unlikely, if not impossible.
[0043] The grinding machine 1 is designed as a multi-station
grinding machine, which has two complete grinding stations 11, 12.
The grinding stations 11, 12 have grinding heads, which can be
moved by means of appropriate positioning devices, for example
compound table arrangements 35, 36 and/or pivot tables 33, 34, in
relation to the saw blade 2. Positioning devices 51, 52 and
arresting devices 53, 54 for the workpiece are furthermore parts of
the grinding stations 11, 12. The workpiece support 14 is used for
positioning the saw blades 2 to the extent that their center axis
is to be fixed in the grinding stations 11, 12. The rotation of the
saw blades 2 around this center axis M, and the clamping in place
of the saw blade in the respective rotated position for performing
the grinding operation is the task of the respective units in the
grinding stations 11, 12.
[0044] If required, the grinding machine can also have three
grinding stations with 90.degree. spacing and a four-armed
workpiece support. For example, the third grinding station can be
used for grinding the tooth face. If desired, the grinding machine
can also perform additional manufacturing steps. For example, in
place of one grinding station, or in addition to the existing
grinding stations, it can be possible to provide a soldering
station, which is arranged at the same angular spacing as the
grinding stations among each other. The soldering station can be
used for fastening hard metal plates on the teeth 3.
[0045] A very rapid and precise, and therefore cost-effective,
processing of saw blades is possible by means of a grinding machine
designed in this way. The grinding machine 1 is particularly suited
for sharpening saw blades in the course of their manufacture.
* * * * *