EP0360389A1 - Method and apparatus in a sheet cutter - Google Patents

Method and apparatus in a sheet cutter Download PDF

Info

Publication number
EP0360389A1
EP0360389A1 EP89307384A EP89307384A EP0360389A1 EP 0360389 A1 EP0360389 A1 EP 0360389A1 EP 89307384 A EP89307384 A EP 89307384A EP 89307384 A EP89307384 A EP 89307384A EP 0360389 A1 EP0360389 A1 EP 0360389A1
Authority
EP
European Patent Office
Prior art keywords
cutter
cutter drum
drum
knife
accumulation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP89307384A
Other languages
German (de)
English (en)
French (fr)
Inventor
Leo Lunden
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Valmet Technologies Oy
Original Assignee
Valmet Ahlstrom Oy
Valmet Karhula Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Valmet Ahlstrom Oy, Valmet Karhula Inc filed Critical Valmet Ahlstrom Oy
Publication of EP0360389A1 publication Critical patent/EP0360389A1/en
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D1/00—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor
    • B26D1/01—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work
    • B26D1/12—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis
    • B26D1/14—Cutting through work characterised by the nature or movement of the cutting member or particular materials not otherwise provided for; Apparatus or machines therefor; Cutting members therefor involving a cutting member which does not travel with the work having a cutting member moving about an axis with a circular cutting member, e.g. disc cutter
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
    • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
    • B26D7/22—Safety devices specially adapted for cutting machines
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/06—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by dry methods
    • D21B1/066—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by dry methods the raw material being pulp sheets
    • D21B1/068—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by dry methods the raw material being pulp sheets by cutting actions

Definitions

  • the invention relates to a method and an apparatus in a sheet cutter such as used in a pulp dryer for minimizing knife loads caused by an accumulation of material.
  • GB Patent 1 108 289 an apparatus is disclosed where the difference in thickness of the material fed through two rotating cutter drums is taken into account.
  • the upper cutter drum is yieldingly mounted in the machine frame.
  • a sensor responds to the raising of the upper cutter drum and the signal is received by an actuator, which raises the upper cutter further to the height required by the thickness of the material.
  • the said GB patent does not present any solution to how to avoid the problem of knife loads caused by a sudden accumulation of material.
  • the invention attemps to overcome or minimize this problem. It has now been discovered to utilize a method wherein the kinetic energy of the rotating drum is controllably converted into gravitational potential energy. Upon an accumulation of material occuring, the rotatable drum is arranged to lift and swing, supported on pivotally mounted bearing housings, or otherwise be displaced. Thus the great kinetic energy of the rotatable knife is substantially converted into potential energy. The lowering of the raised cutter drum is attenuated by means of fluid dampers or other attenuation means.
  • the method for minimizing loads caused by accumulation of material according to the invention is mainly characterized in that, on occurrance of an accumulation of material, the cutter drum is allowed to rise freely upwards, thus converting the kinetic energy substantially wholly into gravitational potential energy.
  • the apparatus according to the invention is mainly characterized in that it includes bearing housings allowing the rising of a pivotally mounted cutter drum, which bearing housings are pivotally mounted on pivots, whereby, on an accumulation of material between the movable knife and the counter knife during the cutting operation, the cutter drum is allowed to rise, and the kinetic energy of the cutter drum is converted into gravitational potential energy.
  • Figure 1 illustrates a sheet cutter 10 which is preferably used in connection with a pulp drying machine (not shown) and which includes a rotatable cutter drum 11 provided with at least one knife 11a.
  • the apparatus comprises a counter knife 12 which is stationary during the cutting operation.
  • An output shaft 15 of the drive motor 13 includes a drive wheel 16, e.g. a cogwheel, on the gears side.
  • the gears 14 include a shaft 18 rotatably mounted in bearings.
  • the shaft 18 includes a drive wheel, preferably a cogwheel 17.
  • Power transmission means e.g., a chain 19, is attached between wheels 16 and 17.
  • shaft 18 has a drive wheel 20, e.g., a belt pulley, which is connected to power transmission means 21, for example a V-belt, which is arranged to connect to a drive wheel 22 connected to a shaft 23 with said drive wheel, preferably also being a belt pulley.
  • a drive wheel 20 e.g., a belt pulley, which is connected to power transmission means 21, for example a V-belt, which is arranged to connect to a drive wheel 22 connected to a shaft 23 with said drive wheel, preferably also being a belt pulley.
  • the shaft 23 runs through a bearing housing 24a and is connected to a shaft journal 25a of the rotatable cutter drum 11.
  • the bearing housing 24a includes a pivot point 26a at one end of the bearing housing.
  • the bearing housing 24a is arranged to swing round or pivot about the pivot point 26a.
  • the bearing housing 24a includes bearing means 27a for the shaft 23.
  • a pivotally mounted bearing housing 24b is correspondingly connected to the other shaft journal 25b of the rotatable cutter drum 11.
  • the bearing housing 24b includes bearing means 27b for the shaft 25b.
  • the bearing housing 24b is arranged to swing round or pivot about a pivot point 26b disposed at the corner of the bearing housing.
  • the pivot points 26a and 26b are preferably made up by bearing means, e.g., trunnions.
  • the motor 13 rotates the cutter drum 11, and thus the material M is cut off between the knife 11a of the cutter drum and the counter knife 12.
  • the apparatus also includes a shear pin 29, on the breakage of which, the cutter drum 11 rises upwards. This prevents damage to the knives and bearing means.
  • Fig. 2 illustrates a clogging or jamming situation.
  • the kinetic energy of the rotating cutter drum 11 is converted into potential energy.
  • the rising of the cutter drum 11 is designated by an arrow L1.
  • Fig. 3 shows an embodiment of the invention where the dropping of the cutter drum 11 back to its lower position is attenuated by an attenuating means 30.
  • the attenuating means can, for example, be a fluid damper.
  • This type of attenuator 30 allows the knife to rise freely upwards, but in the opposite direction the actuator 30 damps the movement and converts the potential energy of the movement, for example, into heat energy or energy stored in the actuator 30, which energy can be freed after the raising and lowering action, thus bringing the actuator back to the state where it functions as an attenuator.
  • the attenuator can also be a flexible damping cushion or other such means.
  • Fig. 4 the method according to the invention is presented as a calculation model.
  • the weight of the cutter drum is 8000 kg and the rotation speed 333 r.p.m.
  • J moment of inertia
  • R1 and R2 are radii of the mantle of the cutter drum
  • ⁇ angular speed
  • m mass
  • g acceleration due to gravity
  • h lifting height for the centre of gravity.
  • the required lifting height calculated with these values is 0.44 m.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Forests & Forestry (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Crushing And Pulverization Processes (AREA)
  • Drying Of Solid Materials (AREA)
  • Details Of Cutting Devices (AREA)
EP89307384A 1988-08-11 1989-07-20 Method and apparatus in a sheet cutter Withdrawn EP0360389A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI883731A FI79572C (sv) 1988-08-11 1988-08-11 Förfarande vid arkskärare och anläggning för användning vid förfarande t.
FI883731 1988-08-11

Publications (1)

Publication Number Publication Date
EP0360389A1 true EP0360389A1 (en) 1990-03-28

Family

ID=8526911

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89307384A Withdrawn EP0360389A1 (en) 1988-08-11 1989-07-20 Method and apparatus in a sheet cutter

Country Status (5)

Country Link
EP (1) EP0360389A1 (sv)
JP (1) JPH0280692A (sv)
KR (1) KR900002904A (sv)
CN (1) CN1040343A (sv)
FI (1) FI79572C (sv)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1108289A (en) * 1965-11-30 1968-04-03 Ariosto Seragnoli Enzo Seragno Method and mechanism for cutting off small sheets from webs of wrapping material, particularly suitable for metallic materials
GB1603999A (en) * 1977-09-28 1981-12-02 Jagenberg Werke Ag Rotary cross cutter

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1108289A (en) * 1965-11-30 1968-04-03 Ariosto Seragnoli Enzo Seragno Method and mechanism for cutting off small sheets from webs of wrapping material, particularly suitable for metallic materials
GB1603999A (en) * 1977-09-28 1981-12-02 Jagenberg Werke Ag Rotary cross cutter

Also Published As

Publication number Publication date
JPH0280692A (ja) 1990-03-20
FI883731A0 (fi) 1988-08-11
CN1040343A (zh) 1990-03-14
KR900002904A (ko) 1990-03-23
FI79572B (fi) 1989-09-29
FI79572C (sv) 1990-01-10

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Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE ES FR GB IT SE

17P Request for examination filed

Effective date: 19900719

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: VALMET-KARHULA INC.

17Q First examination report despatched

Effective date: 19910813

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19911228