US3036607A - Method and device for centering irregularly formed, substantially cylindrical workpieces, such as logs - Google Patents

Method and device for centering irregularly formed, substantially cylindrical workpieces, such as logs Download PDF

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Publication number
US3036607A
US3036607A US822959A US82295959A US3036607A US 3036607 A US3036607 A US 3036607A US 822959 A US822959 A US 822959A US 82295959 A US82295959 A US 82295959A US 3036607 A US3036607 A US 3036607A
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United States
Prior art keywords
workpiece
centering
logs
lifting
substantially cylindrical
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Expired - Lifetime
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US822959A
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English (en)
Inventor
Raura Pentti Valdemar
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FURUPLYWOOD AB
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FURUPLYWOOD AB
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27L—REMOVING BARK OR VESTIGES OF BRANCHES; SPLITTING WOOD; MANUFACTURE OF VENEER, WOODEN STICKS, WOOD SHAVINGS, WOOD FIBRES OR WOOD POWDER
    • B27L5/00—Manufacture of veneer ; Preparatory processing therefor
    • B27L5/02—Cutting strips from a rotating trunk or piece; Veneer lathes
    • B27L5/022—Devices for determining the axis of a trunk ; Loading devices for veneer lathes

Definitions

  • a center line for the log is, as a rule, determined by the eye in connection with fixing the workpiece in the lathe with help of mechanical lifting appliances or manually. Certain simple hand tools are also used for finding this center line. However, in some cases, for certain kinds of wood, a center line is used which is displaced in relation to the geometrical center line of the log, substantially with a view to obtaining certain wood-technical effects.
  • the device described below is designed in such a mannor that at the same time as it lifts the log into the veneer lathe, it automatically determines the desired center line and corrects the errors usually occurring in logs, such as crookedness, conicity and great surface defects.
  • the invention is substantially characterized in that the center is determined in two cross sections located at a certain distance from the ends of the workpiece, starting from three points on the periphery of each cross section, raising the workpiece while it is supported at two points so that the center of each cross section follows a definite line and, when the center has reached a definite position, stopping the workpiece by means of an impulse supplied by a feeling member when said feeling member which is displaced in dependence upon the lifting movement and in the opposite direction, travels towards the workpiece and forms the third point on the periphery of the cross section.
  • the invention relates to a device for finding the center, which is characterized by two independent lifting devices, each supporting the workpiece at a definite distance from the ends of the workpiece, and each comprising a feeling member adapted to be actuated by the workpiece and guided by the respective lifting device, said feeling member stopping the movement of the lifting device when the workpiece has reached the desired position.
  • Each lifting device may be provided with a lifting member which is designed as an arm on which the workpieces rest, and thus serves as a magazine. That part of the lifting member which supports the workpiece, is so designed that the circle center determined by the supporting points and the third point is located in a definite position.
  • the centering is cor- 3,036,607 Patented May 29, 1962 rected by raising or lowering the common center point of the lifting and feeling members.
  • the feeling member When the feeling member has reached its highest position, it is turned for removal of the core and for replacing of the lathe tool.
  • a feed device located on the arm feeds a workpiece one at a time.
  • FIG. 1 is a lateral elevation of the device
  • FIG. 2 an end view
  • FIG. 3 a plan view
  • FIG. 4 a feed device.
  • the workpiece 1 is placed on two spaced arms 2 whereafter it slides, by its own weight, along the arms towards a feed device comprising a part 3 which is so designed that it feeds a workpiece when it is actuated by a force P through a bar 5.
  • a force F is, through bars 6, transmitted to the arms 2 so that the latter raise the workpiece and the movement of the arms is transmitted by link arms 7, 8 and 9 to a bar 11 guided by rollers 10.
  • On said bar 11 there is fixed a feeling member 12 provided with a cross piece 13 which is tangential to the periphery of the workpiece.
  • the impulse supplying part or cross piece 13 of the feeling member 12 acts as a contact element which is operatively connected to the means for moving arms 2 and is arranged to stop the lifting movement of the said arms at contact with the workpiece 1.
  • the centering may be controlled by raising or lowering the lifting and feeling members. This takes place by means of a bar 14 which actuates a bellcrank lever 15 in such a manner that the link arm 8 mounted thereon can be displaced in the vertical direction.
  • the device determines the center points in two cross sections of the log if the cross section is circular.
  • the cross sections are slightly elliptical or irregular, but in practice this is of no importance because the device determines the center, starting from three different tangent lines to the periphery of the cross section.
  • the shape of the log is a straight truncated cone, its center line is obtained by determining the center points in two cross sections taken arbitrarily on the log. If the shape of the log is a curved truncated cone, its center line is found with sufficient exactness by determining the center points in two cross sections located at a fourth of the total length of the workpiece from each end.
  • the lifting movement is obtained either hydraulically, pneumatically or electrically or in some other suitable manner or by these methods in combination.
  • the device is preferably remote-controlled so that the machine operator starts the lifting movement while the centering itself and the return movement of the device take place automatically.
  • a device for centering workpieces having a substantially cylindrical, but irregular, cross section in a lathe comprising two independent lifting devices, each of said lifting devices comprising an arm which is pivotally supported at one end and which, at the other end, is shaped such that it will support a substantially cylindrical workpiece at two points on the periphery of the workpiece and at a definite distance from the ends of the workpiece, said pivotally mounted arms being adapted to support additional workpieces and thus serve as a magazine for feeding workpieces to the lathe, and each lifting device also comprising a feeling member, lever means connecting each of said feeling members to the respective lifting device, the construction and arrangement being such that each feeling member is displaced 3 downward when the lifting device lifts the workpiece through an arcuate path, and is so actuated by said workpiece that, when the feeling member contacts the workpiece, it supplies an impulse which stops the lifting movement when the workpiece is centered in the lathe.
  • a device as claimed in claim 1 characterized by a feed device arranged on the arm for feeding a workpiece one at a time.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Manufacture Of Wood Veneers (AREA)
  • Turning (AREA)
US822959A 1958-07-01 1959-06-25 Method and device for centering irregularly formed, substantially cylindrical workpieces, such as logs Expired - Lifetime US3036607A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1201970X 1958-07-01
SE3036607X 1958-07-01

Publications (1)

Publication Number Publication Date
US3036607A true US3036607A (en) 1962-05-29

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Application Number Title Priority Date Filing Date
US822959A Expired - Lifetime US3036607A (en) 1958-07-01 1959-06-25 Method and device for centering irregularly formed, substantially cylindrical workpieces, such as logs

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US (1) US3036607A (de)
DE (1) DE1201970B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4197888A (en) * 1978-02-21 1980-04-15 The Coe Manufacturing Company Log centering apparatus and method using transmitted light and reference edge log scanner
US4427044A (en) 1981-06-30 1984-01-24 Pigott Enterprises Log centering device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1646115A (en) * 1925-03-25 1927-10-18 John G Sjostrom Veneer lathe

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1024705B (de) * 1956-02-09 1958-02-20 Enso Gutzeit Osakeyhtioe Parvi Kombinierte Zentrier- und Zubringvorrichtung fuer in Furnierschaelmaschinen zu schaelende Rundholzstuecke

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1646115A (en) * 1925-03-25 1927-10-18 John G Sjostrom Veneer lathe

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4197888A (en) * 1978-02-21 1980-04-15 The Coe Manufacturing Company Log centering apparatus and method using transmitted light and reference edge log scanner
US4427044A (en) 1981-06-30 1984-01-24 Pigott Enterprises Log centering device

Also Published As

Publication number Publication date
DE1201970B (de) 1965-09-30

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