Note: Descriptions are shown in the official language in which they were submitted.
- 21 Q60 5 9
Anti-splintering device for sawing machines having a saw
blade.
The invention relates to an anti-splintering device
for sawing machines having a saw blade.
In an apparatus for dividing metal-laminated webs
into individual boards, as is described for example in EP
259,716, the anti-splintering device adopts an unchanged
position relative to the saw blade, the result of which is
that, especially in the event of a change in the cutting
depth, no functional interaction between the anti-splintering
device and the saw blade is guaranteed. As a result of this,
the cut edge of the material is not clean and so has to be
refinished.
On the basis of the above state of the art, the
ob~ect of the invention is to provide a remedy in this
situation.
It will be recognized that the invention is embodied
whenever the anti-splintering device is a member which, in the
operating state of the hand-operated circular saw, is actively
connected simultaneously both to the workpiece and to the
emerging teeth of the saw blade, so that the anti-splintering
device exerts a force not only on the workpiece but also on
the saw blade and interacts with a positioning device which
ensures that the anti-splintering device adopts the correct
operating position. The exertion of force by the anti-
splintering device prevents the formation of a gap between the
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teeth of the saw blade and the anti-splintering device. Since
the anti-splintering device rests in close contact on the
workpiece in the region of the cut, no gap, which could be
regarded as the cause of a ragged cut edge, is formed in this
region either. The cutting line also becomes considerably
more precise as a result of the suppression or even
elimination of vibrations of the saw blade.
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Further expedient and àdvantageous embodiments of
the invention are evident from the subclaims.
If the proposed anti-splintering device is used
in sawing machines with a sawing table, it is expedient
if the part of the anti-splintering device resting on the
workpiece lies in the contact plane defined by the
workpiece and the sawing table or projects from the
sawing table towards the workpiece. The alternative
proposal is particularly suitable when the sawing machine
is used to cut uneven workpieces.
Another expedient embodiment envisages that the
anti-splintering device is adjustable relative to the saw
blade, and can thus be set. This measure, according to
the invention, can be used to particular advantage if the
hand-operated circular saw is designed as an immersion
saw, whose depth of immersion is altered as required, The
radial adjustment of the anti-splintering device ensures
that the anti-splintering device is always in pressure
contact at least with the teeth of the saw blade.
A further expedient embodiment of the invention
envisages that the anti-splintering device can be con-
nected to the sawing machine in an articulated manner and
pivoted about the spindle of the saw blade or about a
spindle extending parallel to that spindle, This measure
ensures that the anti-splintering device can be opera-
tively connected to the teeth of the saw blade even when
the depth of the immersion of the saw blade changes
during the cutting operation. It is further envisaged
that the anti-splintering device interacts with at least
one spring element, by means of which the pressure of the
anti-splintering device acting on the saw blade can be
determined, This measure principally takes account of the
fact that saw blades of different dimensions can be used
in a sawing machine.
Another particularly expedient embodiment en-
visages that the anti-splintering device has a sensor
which is in pressure contact with the body of the saw
blade and supports the part which is in pressure contact
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with the teeth of the saw blade and is designed as an anti-
splintering member. These measures considerably reduce the
wear on the part which is in pressure contact with the teeth
of the saw blade, since the sensor transmits to the saw blade
the actual pressure originating from the anti-splintering
device, whereas the anti-splintering member, which is actively
connected to the teeth of the saw blade, exerts minimal
pressure on the saw blade. The sensor, which preferably
consists of bearing material, simultaneously serves as a
vibration damper for the saw blade, so that two advantages are
achieved by simple measures: first, the wear on the anti-
splintering device is considerably reduced, and secondly the
anti-splintering member can consist of a considerably softer
material than the sensor.
A further particularly expedient embodiment of the
invention envisages that the anti-splintering device can be
accommodated in a housing which is detachably connectable to
the sawing machine, so that it can readily be replaced if the
individual parts of the anti-splintering device are worn.
It is further envisaged that the positioning device
has the shape of an arm, which can be pivoted about a spindle
which extends parallel to the spindle of the saw blade or is
adjustable along a curve which lies in a plane extending
perpendicularly to the spindle. In this arrangement, these
measures can also be taken in such a manner that the anti-
splintering device has the shape of a section of a cylinder,
is rotatable about its spindle and consists of a cuttable
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material. In the context of this concept of the invention, it
is particularly advantageous if the pivot spindle of the arm
is at a distance from the spindle of the saw blade which
corresponds to the radius of the cylindrical anti-splintering
device. The features of the invention ensure that the anti-
splintering device is always arranged in the region of the
teeth of the saw blade emerging from the workpiece. The
advantage of the measures according to the invention resides
in the fact that the
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anti-splintering device is uniformly worn from its working side. Finally,
provision is made for the radial outside of the anti-splintering device to fall
away towards the saw blade. As a result, the operationally correct contact
of the anti-splintering device is ensured, even when the saw blade forms an
acute angle with the plane of the workpiece.
A number of illustrative embodiments of the invention are
shown diagrammatically in the drawing and are explained in detail below.
In the drawing:
Fig.1 shows part of a sawing machine in vertical plan
view with an anti-splintering device,
Fig. 2 shows a sawing machine with a further anti-
splintering device,
Fig. 3 shows a sawing machine whose anti-splintering
device is pivotably mounted,
Fig. 4 shows the sawing machine shown in Fig. 3 in the
direction of the arrow IV, during the cutting
operation,
Fig. S shows the sawing machine shown in Fig. 4
before the cutting operation,
Fig. 6 shows a sawing machine having an anti-
splintering device, whose anti-splintering
member is pivotably mounted,
Fig. 7 shows a lateral view of the sawing machine
shown in Fig. 6,
Fig. 8 shows a sawing table with parts of the anti-
splintering device,
Fig. 9 shows a keyhole saw shown in Fig. 9 in a lateral
view,
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4a
Fig. 10 shows a keyhole saw shown in Fig. 9 in a lateral
view,
Fig. 11 shows an anti-splintering device designed as a
separate part,
Fig. 12 shows the anti-splintering device shown in Fig.
11 in operational connection with a hand-
operated circular saw,
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Fig. 13 shows the hand-operated circular saw shown in
Fig. 12 in the direction of the arrow Xll,
Fig. 14 shows part of a sawing machine in lateral view
with a positioning device designed as an arm,
Fig. 15 shows an end-on view of the sawing machine
shown in Fig. 14,
Figs. 16
and 17 show part of a sawing machine with two
positioning devices, and
Fig. 18 shows a sawing machine with a pivotable sawing
table and a positioning device.
Fig. 1 shows part of a sawing machine with a saw blade 10 and
anti-splintering device 16. The anti-splintering device 16 can be
operationally connected to the sawing machine, can be rested on a
workpiece (not shown) and can be arranged laterally from the saw blade 10
and in the region o the teeth 14 of the saw blade emerging from the
workpiece. Formed in the sawing table 20 of the sawing machine is a saw-
blade passage 18 in which the saw blade 10 is mounted to rotate about the
spindle 24. The anti-splintering device 16 is so designed that it is in
pressure contact with the emerging teeth 14 of the saw blade. The anti-
splintering device 16 is, moreover, so designed that its part 34, which can
be rested on the workpiece, lies in the contact plane defined by the
workpiece and the sawing table 20 towards the workpiece. The anti-
splintering device 16 is accommodated in the housing 50, whose radial
position can be determined by the screws 36 and 38. Since there is no rigid
connection between the set-screws 36, 38 and the housing 50, spring
elements 44 are provided with exert pressure on the housing 50.
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The anti-splintering device 16 further posses a sensor 32,
which is in pressure contact with the body 30 of the saw blade, and the part
34 which is in pressure contact with the teeth 14 of the saw blade and is
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designed as an anti-splintering member. It will be recognized that the
sensor 32 and the anti-splintering member 34 are adjustable in the axial
direction of the saw blade 10 and thus can be set. The anti-splintering
member 34 is adjustable relative to the sensor 32, the sensor 32 being
designed as a dog of the anti-splintering member 34. In the initial position,
that is to say before the anti-splintering device becomes operational, a gap
31 is formed between the sensor and the anti-splintering member 34. If the
sawing machine is now switched on, the teeth 14 of the saw blade are
actively connected to the anti-splintering member 34, which consists of
cuttable material, so that the gap 31 is minimized. In this region, the anti-
splintering member is supported on the sensor 32. Further wear on the anti-
splintering member 34 arises in practice when wear is caused to the sensor
32, which is in pressure contact with the level section of the body 30.
Although both the sensor 32 and the anti-splintering member 34 are each in
pressure contact with one spring element, 26 and 28 respectively, the spring
element 28 can only press the anti-splintering member 34 against the sensor
32. The sensor 32 and the anti-splintering member 34 can additionally be
regulated by set-screws 40 and 42, this regulation taking place towards the
spindle 24. Fig. 2 shows that two sides of the saw blade 10 each interact
with one anti-splintering device. In this arrangement, the individual parts of
the anti-splintering device are of approximately mirror-image design. The
sensor 32', the anti-splintering member 34' and the spring element 26'
approximately correspond to the corresponding parts of the other anti-
splintering device.
Figures 3 to 5 show an anti-splintering device 316 which can
be pivoted, via a joint rod 48 and a joint 46, about a spindle 25. The spindle
25 extends parallel to the spindle 24 of the saw blade 10. Thus, the anti-
splintering device 316 can be pivoted in the direction of rotation of the saw
blade 10. The sensor 32 and the anti-
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CA 021060~9 1998-04-02
splintering member 34 are accommodated in a housing 50. As is
particularly apparent from Figures 4 and 5, the anti-
splintering member 34 is further advanced and has an oblique
stop surface 52. The joint arm 48 interacts with a
compression spring 54, which tends to press the anti-
splintering device 316 against the workpiece.
Figures 6 and 7 show a hand-operated circular saw
with an anti-splintering device 616 which is accommodated in a
housing 650 and has a sensor 632 and an anti-splintering
member 634. Accommodated in the housing 650 is a body 601
which is in pressure contact with the spring element 626 and
bears both the sensor 632 and the anti-splintering member 634.
The sensor 632 can be set by the set-screw 40, while the anti-
splintering member 634 rotatable in an articulated manner to
the body 601 and pivoted about the spindle 51. The anti-
splintering member 634 is rotatable about the longitudinal
axis of the joint arm 47 and pivoted can be in the direction
of the arrows. The joint arm 47 interacts with a spring
element 49, which tends to press the anti-splintering member
634 against the workpiece 12.
Fig. 8 shows a sawing table 20 with a saw-blade
passage 18 and a housing 50. The anti-splintering device 16,
with sensor 32 and anti-splintering member 34, can be
introduced into the housing 50. These two parts are,
furthermore, accommodated in a further housing 2, so that the
insertion of the anti-splintering device 16 into the housing
50 and/or its removal therefrom can take place without
difficulty.
Figs. 9 and 10 show that the anti-splintering device
can also be used with a keyhole saw, the saw blade 914
performing vertical reciprocal movements.
Figs. 11 to 13 show an anti-splintering device 1116,
which is intended as an accessory for hand-operated circular
saws and keyhole saws and is hence designed as a separate
part. This anti-splintering device 1116 consists of a plug
part 1118 with two anti-splintering members 1120 and 1122
which can be positioned laterally
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from the saw blade 10 and consist of cuttable material, that is to say a
material whose hardness is less than that of the teeth of the sawing
machine. The anti-splintering members 1120 and 1122 possess, in the
region of contact with the saw blade 10, sensors 1132 and 1134 whose
hardness is greater than the hardness of the anti-splintering members 1120
and 1122 and which preferably consist of bearing material.
A further feature of the anti-splintering members 1120 and
1122 is that they are articulated on the plug part 1118, this occurring in the
regions 1124 and 1126. The ends of the anti-splintering members 1120,
1122 which are remote from the sensor 1132, 1134 interact with a
compression spring 1130, which tends to press the sensors 1132, 1134
against the saw blade 10. The special feature of this articulation resides, in
particular, in the fact that, as a result of the gap 1110 which i-s formed
between the anti-splintering member 1120, 1122, the two anti-splintering
members can be brought independently of each other into pressure contact
with the saw blade 10. They are thus, as it were, in floating pressure contact
with the saw blade 10 and can therefore follow lateral movements of the saw
blade . The sawing machine possesses a plug socket 1136 with a tensioning
screw 1140, which serves to fix the plug part 1118. A further special feature
of the anti-splintering device 1116 resides in the fact that it can also
preferably be actively connected to guide rails for sawing machines, since
its thickness approximately corresponds to the thickness of the guide rails,
so that the anti-splintering device 1116 can rest in close contact on the
workpiece without a gap forming between the saw tooth 14 and the anti-
splintering member 1120, 1122, which gap would critically contribute to the
formation of splinters in the region of upper edges of the workpiece.
Figures 14 to 16 shows a cylindrical anti-splintering member
634, which is supported by a positioning device 3 having an arm 7. The arm
7 has two elbows and is
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CA 021060~9 1998-04-02
articulated at a distance r vertically above the spindle 24 of
the saw blade 14. The distance r corresponds to the radius r
of the anti-splintering member 634. The result is to ensure
that the anti-splintering member 634 always rests on the
workpiece 12 precisely where the teeth of the saw blade 14
emerge from the workpiece. When the arm 7 is pivoted, the
bearing point of the anti-splintering member 634 moves along a
circular path along the circumference of the saw blade 14,
and, in so doing, can roll on the workpiece 12. The anti-
splintering member 634 has a cylindrical recess 5 which is
open towards the saw blade 14, and its circumferential surface
6 falls away towards the saw blade 14 (cf. Figures 16, 17).
As a result of this measure it is possible, in the case of an
anti-splintering member consisting of cuttable material such
as plastic, for it to be worn equally by the teeth of the saw
blade. In order to minimise the wear on the member 634, a
sensor 32 consisting of a bearing material with good slip
properties is also provided in this illustrative embodiment.
the sensor may consist of bronze, sintered metal or carbon.
The arm 7 interacts with a tension spring 19, which
presses the anti-splintering member 634 against the workpiece
12. Even after adjustment of the sawing table 20 to alter the
cutting depth, or after pivoting in order to saw a bevel or an
angled cut (see Figures 15 and 17), the anti-splintering
member 634 always automatically comes to rest at the right
point in the region of the teeth of the saw blade 14. Figures
16 and 17 show that the saw blade 14 is flanked by an anti-
splintering member 634 on each side, these being supported by
arms 7 which are arranged parallel but are separate.
As the illustrative embodiment according to Figure
18 shows, however, the anti-splintering member 34 can also be
of block-shaped design and be articulated on a positioning
device designed as a rod 11. This is arranged in the spindle
13 on the housing 8 or on the protective hood of the hand-
operated circular saw. The spindles 13, 15, 24 of the joints
run parallel to each other. The surface in contact with the
saw blade 14 of the anti-splintering member 34 is clearly
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greater than, preferably at least about four times as great
as, the surface brushed by the teeth of the saw blade 14, so
that the teeth remain in contact with the anti-splintering
member 34 at every cutting depth, that is to say in every
position of the sawing table 20; even when the sawing table 20
is pivoted about the spindle 9. As in the previous
illustrative embodiments, the anti-splintering member 34 is
connected to a sensor 32 which is supported on the untoothed
lateral surface of the saw blade 14. The sensor 32 is, for
this purpose, arranged at a point of the anti-splintering
member 34 which is close to the spindle and remote from the
sawing table 20, or even on a corresponding bracket.
The anti-splintering member 34 can be displaceable
in a groove in the sawing table 20, along the bearing surface
thereof, or is pressed onto the workpiece by means of a spring
54' supported on the housing 8, so that it always rests flat.
The rod 11, for example, can serve to press the anti-
splintering member 34 against the saw blade 14, in which case
the rod 11 is of resilient design and is mounted on the
housing 8 with prestress towards the saw blade 14. The
positioning devices 3 and 11 are also, naturally, arranged in
pairs to the left and right and adjacent to the saw blade 14,
so that this is subjected resiliently to the effect of one
anti-splintering member 34 on each side.
The positioning device could, of course, also be of
different design. A control cam, for example, would be
especially conceivable, extending parallel to the saw blade
and guided along a control arm, one end of which bears the
deflection guard 34. In this case the dimensions of the
control cam and of the arm would have to be such that the
deflection guard adopts the necessary position relative to the
teeth of the saw blade emerging from the workpiece when the
sawing table is adjusted.
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Another possible embodiment offers a prestressed cable
pull by which the deflection guard is set.
In summary, it may be stated that the proposed
anti-splintering device or the deflection guard system
can be employed with hand-operated circular saw, keyhole
saws, stationary saws or even industrial saws. The
production costs of the anti-splintering device are
m;n;m~l ~ since it can be assembled from separate com-
ponents, which are then operationally connected to a
hand-operated circular saw. The splintering of the
material is prevented directly at the saw tooth, so that
no parallel guidance of the sawing table is required. The
complete deflection guard with sensor is resiliently
guided on the saw blade so that no gap is formed between
the saw teeth and the deflection guard. The sensor can,
however, also be retrospectively adjusted as required.
A further advantage of the proposed anti-
splintering device resides in the fact that it can also
be attached underneath the sawing table. As a result,
splintering is prevented even if there are irregularities
of the workpiece surface. In this arrangement, it is
advantageous to attach the anti-splintering device
resiliently to the sawing machine. The sensor and anti-
splintering member are mouldings which can easily be
replaced and are economical to produce.
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