EP0560524A1 - Aus Lamellen gebildete Gabel - Google Patents

Aus Lamellen gebildete Gabel Download PDF

Info

Publication number
EP0560524A1
EP0560524A1 EP93301557A EP93301557A EP0560524A1 EP 0560524 A1 EP0560524 A1 EP 0560524A1 EP 93301557 A EP93301557 A EP 93301557A EP 93301557 A EP93301557 A EP 93301557A EP 0560524 A1 EP0560524 A1 EP 0560524A1
Authority
EP
European Patent Office
Prior art keywords
fork
layers
heel
lamination
blade
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Withdrawn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
EP93301557A
Other languages
English (en)
French (fr)
Inventor
Alan E. Green
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0560524A1 publication Critical patent/EP0560524A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/12—Platforms; Forks; Other load supporting or gripping members

Definitions

  • This invention relates to improvements in forks for material handling vehicles popularly known as lift trucks.
  • Forks for use with lift trucks are typically manufactured of steel or other metallic members.
  • the fork comprises a blade, a heel and a shank.
  • Various means may be used to attach the fork to the lift truck.
  • Forks may be of any size or configuration required to carry the load intended. Most often forks are used with the blade extending substantially horizontally and the shank extending substantially vertically upwardly. Occasionally, however, forks are used where the blade is substantially horizontal and the shank portion extends substantially vertically downwardly. These latter types of forks are referred to in this disclosure as inverted forks.
  • Forks are typically manufactured from steel.
  • the steel may be configured in the desired shape for the cross-sectional configuration for the shank and blade.
  • the thickness of the material normally requires that the material be heated, at least in the region of the heel so that the material can be bent into the typical substantially right angle configuration. In many cases an upset procedure is used to ensure thickening of the fork material in the heel region. This is often advantageous because the stresses are highest in the heel region and thicker metal can be used to carry those stresses.
  • the tip of the blade may be considerably thinner in cross-section than the portions of the fork immediately adjacent to the heel as the stresses at the tip of the blade are considerably lower than adjacent the heel.
  • a fork formed from a solid steel bar may be surface coated with brass or bronze or be made from solid brass or bronze or the like to reduce or eliminate sparking.
  • a fork may be coated with various forms of surface coating or made entirely from a suitable material such as stainless steel all to meet whatever need is required.
  • the fork has a plurality of lamination layers. While the fork will have a blade, a heel and a shank, any one or more of those portions of the fork may be formed from a plurality of lamination layers. Each lamination layer is fixed to the next adjacent layer so that stresses are communicated from one layer into the next adjacent layer. Fixation of the layers may be accomplished with adhesives or by welding.
  • a method for making such a fork involves bending a first lamination layer in a die.
  • a second lamination layer may be bent using the first layer which remains in the die to form the next lamination. This can be repeated for as many layers as desired.
  • the layers may be fixed to each other as they are bent or after all bending has been completed.
  • the tensile layer is of a strength to provide the basic surface capabilities while providing sufficient thickness to allow the use of any desired joining media.
  • Each successive lamination layer is to be of any desired thickness and strength. The exact parameters of each layer is dependent upon the total thickness and width of the fork and the load to be applied.
  • the fork designer has complete freedom as to the number of lamination layers, the thickness of the lamination layers and the location of the lamination layers. In certain cases only the shank will be laminated. In other cases only the blade will be laminated and in still other cases it will be only the heel area that contains lamination layers. These may be combined as the designer chooses.
  • the individual lamination layers are affixed to one another. This may be done by applying adhesives that form chemical bonds or by any form of welding. Suitable adhesives for bonding layers of steel include epoxy resins and urethanes.
  • top surface is used to describe the surface that is loaded in tension under load. In most cases this will be the upper surface of the blade and in the case of a typical fork would be the inner surface of the shank, while in the case of an inverted fork would be the outer surface of the shank.
  • the top surface of a fork requires a yield point which provides a three to one safety factor in accordance with the following calculation: where where
  • the thickness of the top layer is variable and is determined by an adaptation of the previous formulae:
  • lower strength materials such as C1010, C1015, C1018 or equivalent material in the bottom layers is sufficient as the compressive strength of such materials far exceeds the tensile strength and compression action is not normally a feature of fatigue failure mechanism within the confines of fork stresses.
  • the material of the bottom layer may be modified at will to suit specific requirements. While it may be appropriate to vary the material from lamination to lamination, it is within the scope of this invention to create a fork having a plurality of lamination layers where all of the layers are of the same material. It is possible to make a fork of sufficient thicknesses required to resist flexing at the designed load of entirely low strength materials by using sufficient thicknesses and numbers of lamination layers.
  • a fork required to resist corrosion could be made entirely from stainless steel.
  • a very light fork could be made from aluminium.
  • a spark resistant fork could be made entirely from brass or a series of brass or bronze alloys, again reflecting the surface strength requirements.
  • Figure 1 illustrates a fork 10 having a blade 12, a heel 14 and a shank 16.
  • This fork as illustrated is intended to be used in the conventional fashion, that is with the blade extending substantially horizontally and the shank extending substantially vertically upwardly from the blade.
  • the fork has an inner surface 20 which comprises the upper surface of the blade 12, the inner radius of the heel 14 and the inner surface of the shank 16.
  • the fork has an outer surface 22 which comprises the lower surface of the blade 12, the outer radius of the heel 14 and the outer surface of shank 16. In this fork the surface 20 will be loaded in tension while the surface 22 will be loaded in compression.
  • Figure 2 illustrates the lamination layers of the fork of Figure 1.
  • the shank 16 includes four lamination layers 30, 32, 34 and 36.
  • the blade 12 also includes the same four lamination layers 32, 34 and 36.
  • the blade is tapered in the region 40 as the stresses are considerably lower towards the tip of the fork than adjacent the heel region.
  • the layer 36 which is at the outer surface of the shank and the fork does not extend all the way to the tip of the fork. Machining of the fork may be required in the area 40 to give a smooth surface to the bottom of the fork.
  • the heel region 14 includes two additional lamination layers 44 and 46. These layers will be loaded in compression during use of the fork of Figure 1.
  • the lamination layers 44 and 46 as shown in Figure 2 comprise portions of a longer length of material that has been affixed to the lamination layer 36. After affixation the heel area will be machined to the configuration shown. This is done to provide a smooth generally vertical surface 22 so that the surface of lamination layers 44 and 46 is a continuation of the flat, vertical surface 22 at the outside surface of the shank 16.
  • the lamination layers 44 and 46 may be machined to comprise a flat surface aligned with surface 22, the lower surface of the blade 12.
  • All of the lamination layers 30, 32, 34, 36, 44 and 46 comprise two surfaces, an inner surface and an outer surface.
  • the outer surface of lamination layer 30 matches precisely the inner surface of lamination layer 32.
  • these surfaces are referred to as complimentary surfaces. By this it is meant that when the two lamination layers are placed against each other there is full surface contact throughout the entire extent of that surface.
  • lamination layers 32 and 34 have complimentary surfaces.
  • Lamination layers 34 and 36 have complimentary surfaces
  • layers 36 and 44 have complimentary surfaces
  • layers 44 and 46 have complimentary surfaces.
  • the complimentary surfaces may be joined by adhesives forming suitable chemical bonds. Such a bond is shown by way of illustration in Figure 4 as a heavy line 50 between layers 34 and 36.
  • layer 30 is fixed to layer 32 and layer 32 is fixed to layer 34 by welding.
  • the weld beads 52 extend along the side edges of the fork for the entire extent of the contact between the complimentary surfaces. Any type of welding which is satisfactory for joining the materials in question may be used.
  • the weld need not be continuous but must of course be sufficient to affix the two surfaces one to the other to pass the stresses from the respective layers of the lamination.
  • the type of welding and the amount of welding may vary depending upon how close the weld is to the neutral axis of the material where there will be a minimum requirement. It may also be possible to use less weld material if desired away from the heel region of the fork where the maximum stresses will be occurring.
  • Figure 3 illustrates a portion of a fork in which the shank 16 and the blade 12 comprise a single layer material 60.
  • the heel 14 comprises additional reinforcing lamination layers 62 and 64.
  • the lamination layers 62 and 64 are essentially similar to those discussed above as layers 44 and 46. In a fork of this configuration the lamination layer 60 will be loaded in tension at its surface 20 and loaded in compression at its surface 22.
  • the reinforcing lamination layers 62 and 64 of the heel 14 will be loaded in compression or tension depending upon the location of the neutral axis for the particular configuration of the heel chosen.
  • the fork of Figure 5 is similar in most respects to the forks discussed above, but is intended to be used as an inverted fork.
  • This fork 70 comprises a blade 12, a heel 14 and a shank 16.
  • the inner surface 20 comprises the lower surface of the blade 12, the inner radius of the heel 14 and the inside surface of the shank 16.
  • the outer surface 22 of the fork 70 comprises the upper surface of the blade 12, the outer radius of the heel 14 and the outer surface of the shank 16. In this fork the outer surface 22 is loaded in tension and the inner surface 20 is loaded in compression when the fork is in use.
  • the fork 70 comprises three lamination layers 72, 74 and 76 which have respective complimentary surfaces. These three lamination layers extend from the shank 16 through the heel 14 and into the blade 12.
  • the heel 14 comprises two additional lamination layers 78 and 80 which extend only over the heel area 14.
  • the affixing and machining of the lamination layers 72, 74, 76, 78 and 80 is similar to the production of the fork 10 referred to above.
  • a further lamination layer 82 is then added to the fork.
  • the lamination layer 82 has a surface which is complimentary to the lamination layer 76 in the region of the shank 16 and in the region of the blade 12.
  • the lamination layer 16 has a surface which is complimentary to the machined surfaces of the lamination layers 78 and 80.
  • the complimentary surface of the lamination layer 16 provides full surface to surface contact which the remainder of the fork.
  • the lamination layer 82 which is of the hi-tensile material while the remainder of the layers 72, 74, 76, 78 and 80 may be chosen from other materials as appropriate.
  • the thicknesses of the various lamination layers are not necessarily the same and may be selected by the designer to meet the strength requirements as selected by the designer.
  • a plate of the required thickness would be cut to form a bar of the correct length and width. In some cases the widths or thicknesses may be varied along the length.
  • the bar would then be placed in the correct position in a die and bent to the radius of that die. This bar would then constitute the inside surface 20, that is the surface having the smallest radius for the heel section.
  • the second bar could then be formed by leaving the first layer in position in the die. The second bar can then be bent in accordance with the radius formed by the combination of the die and the first layer. This will then produce a complimentary surface between the first and second lamination layers. The process is then continued by adding successive layers including those designed for the heel area until the desired thickness of the fork is achieved.
  • each layer apart from the first may be determined by the maximum thickness which may be bent over the particular radius without undue deformation and for the strength of the press available and/or whether or not heat is used in the bend area.
  • inverted fork machining would be required in the heel section before inserting the formed fork into the die for production of any additional layer such as lamination layer 82.
  • any desired machining may be carried out in a normal fashion. This could be used to produce smooth edges where tapers are required or desirable or include shaping of the heel sections as may be most appropriate. Any of the ordinary configuration of heel section may be machined into the laminated fork made in accordance with this invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
EP93301557A 1992-03-10 1993-03-01 Aus Lamellen gebildete Gabel Withdrawn EP0560524A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US84878092A 1992-03-10 1992-03-10
US848780 1992-03-10

Publications (1)

Publication Number Publication Date
EP0560524A1 true EP0560524A1 (de) 1993-09-15

Family

ID=25304247

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93301557A Withdrawn EP0560524A1 (de) 1992-03-10 1993-03-01 Aus Lamellen gebildete Gabel

Country Status (2)

Country Link
EP (1) EP0560524A1 (de)
CA (1) CA2089960A1 (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19515834C1 (de) * 1995-04-29 1996-05-23 Vetter Umformtechnik Gmbh Gabelzinke
EP1690822A2 (de) * 2005-02-15 2006-08-16 Vetter Umformtechnik GmbH Beschichtete Gabelzinken insbesondere für Gabelstapler
WO2012171051A1 (de) 2011-06-15 2012-12-20 Szlezak Philipp Verfahren zur herstellung einer gabelzinke und gabelzinke
US9802802B2 (en) 2015-03-23 2017-10-31 Caterpillar Inc. Work tool

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE379976C (de) * 1922-11-25 1923-08-31 Ag Deutsche Maschf Lasthaken fuer Hebezeuge
GB666102A (en) * 1949-09-27 1952-02-06 Wards Welders Ltd Improvements relating to mechanical handling trucks
US2817792A (en) * 1956-01-11 1957-12-24 Production Plastics Corp Material handling apparatus
FR2237831A1 (de) * 1973-07-17 1975-02-14 Lancer Boss Ltd
US3897097A (en) * 1974-01-07 1975-07-29 Jr Howard G Davis Flying fork-type lifting member
DD265050A3 (de) * 1987-04-20 1989-02-22 Fortschritt Veb K Gabelzinke fuer lastfoerdergeraete
US4810016A (en) * 1984-10-16 1989-03-07 Stelco Inc. Lifting hook

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE379976C (de) * 1922-11-25 1923-08-31 Ag Deutsche Maschf Lasthaken fuer Hebezeuge
GB666102A (en) * 1949-09-27 1952-02-06 Wards Welders Ltd Improvements relating to mechanical handling trucks
US2817792A (en) * 1956-01-11 1957-12-24 Production Plastics Corp Material handling apparatus
FR2237831A1 (de) * 1973-07-17 1975-02-14 Lancer Boss Ltd
US3897097A (en) * 1974-01-07 1975-07-29 Jr Howard G Davis Flying fork-type lifting member
US4810016A (en) * 1984-10-16 1989-03-07 Stelco Inc. Lifting hook
DD265050A3 (de) * 1987-04-20 1989-02-22 Fortschritt Veb K Gabelzinke fuer lastfoerdergeraete

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19515834C1 (de) * 1995-04-29 1996-05-23 Vetter Umformtechnik Gmbh Gabelzinke
EP0739854A1 (de) * 1995-04-29 1996-10-30 Vetter Umformtechnik GmbH Gabelzinke
EP1690822A2 (de) * 2005-02-15 2006-08-16 Vetter Umformtechnik GmbH Beschichtete Gabelzinken insbesondere für Gabelstapler
EP1690822A3 (de) * 2005-02-15 2007-08-15 Vetter Umformtechnik GmbH Beschichtete Gabelzinken insbesondere für Gabelstapler
WO2012171051A1 (de) 2011-06-15 2012-12-20 Szlezak Philipp Verfahren zur herstellung einer gabelzinke und gabelzinke
AT511652A1 (de) * 2011-06-15 2013-01-15 Szlezak Philipp Gabelzinke
AT511652B1 (de) * 2011-06-15 2013-07-15 Szlezak Philipp Gabelzinke
CN103648962A (zh) * 2011-06-15 2014-03-19 菲利普·斯勒扎克 制造叉臂的方法和叉臂
JP2014522353A (ja) * 2011-06-15 2014-09-04 スレザック，フィリップ フォークアームの製造方法とフォークアーム
RU2556807C1 (ru) * 2011-06-15 2015-07-20 Филипп ШЛЕЗАК Способ изготовления зубца вил и зубец вил
US9624080B2 (en) 2011-06-15 2017-04-18 Philipp Szlezak Method for producing a fork arm, and fork arm
US9802802B2 (en) 2015-03-23 2017-10-31 Caterpillar Inc. Work tool

Also Published As

Publication number Publication date
CA2089960A1 (en) 1993-09-11

Similar Documents

Publication Publication Date Title
CN109382631B (zh) 异种材料的设计特征—增强坯料和成形挤出
US4824314A (en) Composite fastener system and manufacturing method thereof
US3610290A (en) Metal laminates and tubing embodying such laminates
US6605370B2 (en) Method of manufacturing an aluminium joined product
EP2127797A1 (de) Verfahren zur Verbindung unterschiedlicher Metalle aus einem Stahlprodukt und einem Leichtmetallprodukt
AU711682B2 (en) Composite panel
US20110027047A1 (en) Solid rivet for joining composite component parts
US5016807A (en) Method for producing workpieces of metal
EP0305113B1 (de) Rotierende oder bewegende metallische Komponenten und Verfahren zur Herstellung solcher Komponenten
US5093209A (en) Compound steel workpiece
US6314834B1 (en) Hollow crank arm
EP0813455B1 (de) Rohre aus rostfreiem stahl und verfahren zur ihrer herstellung
US5289965A (en) Method of superplastically forming and braze bonding a structure
US5429879A (en) Laminated metal composite formed from low flow stress layers and high flow stress layers using flow constraining elements and making same
EP0560524A1 (de) Aus Lamellen gebildete Gabel
US5664453A (en) Hollow extruder die for extruding a hollow member of a zinc-containing aluminum alloy
US4722125A (en) Method for producing a tungsten carbide tip punch
US4133471A (en) Method for making clad metal sheets having at least one curved major surface
US4551896A (en) Method of manufacturing a rotor for a rotary fluid pump
EP0995511A2 (de) Material mit Schichtstruktur und Verfahren zu seiner Herstellung
US4893744A (en) Lining method using clad pieces and a clad piece for the method
US4469349A (en) Stabilizer
EP0592495B1 (de) Superplastischer geformter und diffusions verschweisster strukturen
WO2021200695A1 (ja) リベット継手の製造方法、リベット継手、及び自動車部品
DE2745163C2 (de) Verfahren zum Herstellen eines Rades für luft- oder gasgefüllte Reifen von Kraftfahrzeugen

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): DE FR GB

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: 19940316