U.S. patent application number 09/911018 was filed with the patent office on 2002-03-14 for sharpening unit with disc wear recovery for stick or log cutting machine.
Invention is credited to Gambini, Giovanni.
Application Number | 20020031991 09/911018 |
Document ID | / |
Family ID | 11445579 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031991 |
Kind Code |
A1 |
Gambini, Giovanni |
March 14, 2002 |
Sharpening unit with disc wear recovery for stick or log cutting
machine
Abstract
A sharpening unit with disc wear recovery for stick or log
cutting machine in which the cutting machine is provided with at
least one cutting head (15) bearing a motorized cutting disc (12)
which cuts transversally into rolls the sticks or logs (13)
positioned on a feed surface (14), the head (15) being fitted on a
rotating arm (20) with respect to a central shaft (17) positioned
on a cross member (16) which can be moved up and/or down with
respect to the feed surface (14), where the unit is also arranged
coaxial to the central shaft (17) and comprises a first lever (37),
hinged to the central shaft (17) and mounted on a secondary shaft
(38) coaxial with it, connected by means of an articulated joint
(32) to a trolley (31) sliding with respect to a second lever (28)
which rotates around a rotation axis (27) of the cutting disc (12),
the trolley (31) bearing at least one grinding wheel (33) to
sharpen the cutting disc (12), the central shaft (17) and the
secondary shaft (38) being connected by synchronized movement
elements (40).
Inventors: |
Gambini, Giovanni; (Pisa,
IT) |
Correspondence
Address: |
James V. Costigan, Esq.
HEDMAN & COSTIGAN, P.C.
Suite 2003
1185 Avenue of the Americas
New York
NY
10036-2646
US
|
Family ID: |
11445579 |
Appl. No.: |
09/911018 |
Filed: |
July 23, 2001 |
Current U.S.
Class: |
451/293 |
Current CPC
Class: |
B26D 7/12 20130101; B24B
3/368 20130101 |
Class at
Publication: |
451/293 |
International
Class: |
B24B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2000 |
IT |
MI2000A 001722 |
Claims
1. A sharpening unit with disc wear recovery for stick or log
cutting machine in which said cutting machine is provided with at
least one cutting head (15) bearing a motorised cutting disc (12)
which cuts transversally into rolls the sticks or logs (13)
positioned on a feed surface (14), said head (15) being fitted on a
rotating arm (20) with respect to a central shaft (17) positioned
on a cross member (16) which can be moved up and/or down with
respect to said feed surface (14), characterised in that it too is
fitted coaxial to the central shaft (17) and comprises a first
lever (37), hinged to the central shaft (17) and mounted on a
secondary shaft (38) coaxial with it, connected by means of an
articulated joint (32) to a trolley (31) sliding with respect to a
second lever (28) which rotates around a rotation axis (27) of the
cutting disc (12), said trolley (31) bearing at least one grinding
wheel (33) to sharpen said cutting disc (12), said central shaft
(17) and said secondary shaft (38) being connected by synchronised
movement elements (40).
2. Sharpening unit according to claim 1, characterised in that said
trolley (31) features a supporting plate (32), integral with it,
bearing two grinding wheels (33), each of which features an axis
(X) slanting in the opposite direction thus interacting from
opposite sides with the cutting edge (35) of said cutting disc
(12).
3. Sharpening unit according to claim 1, characterised in that said
articulated joint is a ball joint (32).
4. Sharpening unit according to claim 1, characterised in that the
rotating arm (20) bears two cutting heads (15) positioned
diametrically opposite to each other and each of said heads (15) is
provided with a respective first lever (37) which can rotate around
the respective rotation axis (27) of each cutting disc (12).
5. Sharpening unit according to claim 1, characterised in that said
synchronised movement elements consist of an angle timing device
(40).
Description
[0001] The present invention refers to a sharpening unit with disc
wear recovery for a stick or log cutting machine.
[0002] Both in the field of preparation of cores or sticks for
winding kitchen paper and/or toilet roll and in the field of the
production of rolls of paper wound on said sticks with
pre-established diameter and set height, the individual final rolls
have to be subsequently cut to size ready for distribution and
use.
[0003] At present, cutting to size of these final rolls is
performed by cutting machines which receive the individual log, for
example, and cut it in succession into a number of shorter rolls,
each with the required dimensions.
[0004] These cutting machines use rotating blades, in the form of
cutting discs, which cut the log or stick as it is gradually fed
step by step, reducing it into a number of pieces of the required
size.
[0005] These disc blades feature a sharpened part or cutting edge
which, as it is used, wears out or is lost and must be dressed in
order to operate as required.
[0006] For this purpose various systems currently exist for
recovery of the wear indicated above.
[0007] The known systems are particularly complicated and do not
take account, in a simple and immediate fashion, of the fact that
as the disc wears, it becomes smaller in diameter. This involves
appropriate movement of the sharpening device which, at the moment,
is not simple and requires intervention by skilled operators.
[0008] Up to now devices for sharpening of said discs while they
are moving have been proposed which permit recovery of the wear on
the disc directly while it is moving after a certain number of
pre-set cuts or according to a detection device connected to
it.
[0009] These devices suffer from technical problems due to
connection of the electrical and electronic parts by means of
rotating elements. Furthermore, due to the fact that recovery of
the wear is performed while the disc is moving, there are large
masses moving which create a number of further problems.
[0010] The main object of the present invention is to produce a
sharpening unit that solves the above problems.
[0011] A further object of the present invention is to produce a
unit for sharpening the discs of a cutting machine that eliminates
the problems with connection of the electrical and electronic parts
by means of rotating elements.
[0012] A further object of the present invention is to produce a
unit for sharpening the discs of a cutting machine in which the
moving masses are reduced to a minimum, eliminating all related
problems.
[0013] These objects according to the present invention are
achieved by producing a sharpening unit with disc wear recovery for
stick or log cutting machine as described in claim 1.
[0014] Additional characteristics are described in the dependent
claims.
[0015] The characteristics and advantages of a sharpening unit with
disc wear recovery for a stick or log cutting machine according to
the present invention will be illustrated more clearly in the
following description, which is intended as a non-restrictive
example, referring to the attached schematic drawings in which:
[0016] FIG. 1 is a front view of a sharpening unit with disc wear
recovery fitted on the head of a stick or log cutting machine;
[0017] FIG. 2 is a rear partial enlarged view of part of the unit
of FIG. 1;
[0018] FIG. 3 is a section view along the line III-III of FIG.
1;
[0019] FIG. 4 is an enlarged view, partly in section, of part of
half the unit shown in FIG. 1 illustrating one single cutting head
and the respective part of the sharpening unit.
[0020] With reference to the figures, a sharpening unit 11 is shown
with wear recovery of a cutting disc 12 for the head 15 of a stick
or log cutting machine, schematised in 13, on a feed surface
14.
[0021] In the example shown, the cutting unit, consisting of two
cutting heads 15 arranged diametrically opposite each other, is
fitted on a general cross member 16 which can be moved up and/or
down with respect to the feed surface 14 by means of a control
unit, not shown, and is rotated by means of a central shaft 17. In
particular, it should be noted that a sleeve 18 is fixed to the
cross member 16 and is positioned coaxial externally to the central
shaft 17, which passes inside it. The sleeve 18 supports, revolving
via bearings 19, a rotating arm 20 which extends from both sides of
the central shaft 17 and is fitted with a pair of cutting heads 15
of the cutting machine. Each cutting head 15 has its own structure
and is fitted with the above-mentioned cutting disc 12. The cutting
disc 12 is rotated by a kinematic chain (not specifically shown)
fitted at the end with a timing pulley 21 moved by a timing belt
22, due also to the presence of relay pulleys 23. A profiled box 24
bearing the moving part of the cutting disc 12 is rotated by a
further pulley 25, controlled by a belt 26, with relay pulleys 23,
and coaxial to the timing pulley 21. Each cutting disc 12 rotates
around a rotation axis 27 which can be moved according to the
movements of the rotating arm 20 and profiled box 24.
[0022] According to the present invention, the sharpening unit 11
is positioned in a cutting machine of the type described above.
[0023] In particular, the sharpening unit 11 comprises, revolving
axially around the rotation axis 27 of each cutting disc 12, a
lever 28 supported at one end by bearings 29. The lever 28 houses a
linear guide 30 bearing a trolley 31 on which two grinding wheels
33 are fitted by means of a supporting plate 32. The two grinding
wheels 33 each have X axis slanting in the opposite direction to
the other grinding wheel axis thus collaborating from opposite
sides with the cutting edge 35 of the cutting disc 12.
[0024] In its turn the trolley 31 bears half of an articulated
joint such as a hinged joint or a ball joint 36, the second half of
which is positioned on a further lever 37 controlled by a secondary
rotation shaft 38 positioned coaxially inside the central shaft 17,
which is the fulcrum of the lever 37. The lever 37 is also
supported by bearings 39 on the outer surface of the central shaft
17 which bears the rotating arm 20 with the cutting discs 12. The
secondary rotation shaft 38 is thus independent of the central or
main rotation shaft 17.
[0025] According to the invention, furthermore, the main rotation
shaft 17 of the rotating arm 20 and the secondary rotation shaft 38
of the further lever 37 are connected to an angle timing device
40.
[0026] Said angle timing device 40 takes its movement from a main
motor 42 and, via a transmission with differential inside the
timing device 40, permits transmission in a ratio of 1/1 between
the two outlet shafts 17 and 38.
[0027] This angle timing device 40 has the job of angle timing the
two shafts 17 and 38 also with the shafts moving.
[0028] Alternatively, synchronised movement elements can be
provided such as electronic or electromechanical means for
coordinating rotation of the central shaft and secondary shaft.
[0029] In the example shown, a retiming motor 41 of the angle
timing device 40 varies the angle between the main tool holder arm
20 and the wear control lever 37 on the cutting discs 12.
[0030] Variation of this angle involves sliding of the grinding
wheel trolley 31 on the linear guide 30 positioned on the lever 28
hinged coaxially to each cutting disc 12. Sliding of the trolley 31
causes the grinding wheels 33 fitted on the same to move nearer or
farther away from the centre of the disc.
[0031] In this way it is possible to control with an accuracy of
one hundredth of a millimeter the position of the grinding wheels
with respect to the cutting disc.
[0032] It is also important to note that all electrical and
electronic contacts in the moving part have been eliminated.
[0033] Furthermore, the presence of elements with non-significant
mass minimises the rotating masses employed in said grinding wheel
sharpening unit.
[0034] A sharpening unit according to the present invention
therefore permits sharpening of the cutting discs while they are
moving, without any problem, directly preparing for said operation
as the cutting disc diameter is gradually reduced by wear.
* * * * *