US3421775A - Low-lift pallet truck - Google Patents

Low-lift pallet truck Download PDF

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Publication number
US3421775A
US3421775A US614157A US3421775DA US3421775A US 3421775 A US3421775 A US 3421775A US 614157 A US614157 A US 614157A US 3421775D A US3421775D A US 3421775DA US 3421775 A US3421775 A US 3421775A
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cross
lever
lifting
members
low
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US614157A
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George Michel Dugelay
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SAXBY
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SAXBY
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
    • B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
    • B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
    • B62B3/0618—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground using fluid lifting mechanisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
    • B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
    • B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
    • B62B3/0625—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground using rigid mechanical lifting mechanisms, e.g. levers, cams or gears

Definitions

  • Low-lift pallet trucks of known types generally cornprise a frame having two longitudinal members or fork arms which are fitted at one end with casters and joined together at the other end by a bridge, said bridge being supported on an elevating unit which is carried by a guide-wheel axle.
  • the lifting action is performed by means of a link-rod system ycomprising a lifting cross-shaft which is rotatably mounted at each end on the truck frame and on each side of which are keyed respectively a top lever and a bottom lever, the end of said top lever being pivoted about a pin carried by the guide-wheel axle and the end of said bottom lever being pivotally coupled to one end of a transmission link-rod extending along the corresponding longitudinal member whilst the other end of said transmission rod is adapted to actuate a system for lifting and lowering casters relatively to the truck frame, with the result that the longitudinal members ⁇ are lifted on the casters when the elevating unit lifts the bridge from the guide-wheel axle.
  • the ⁇ aim of this invention is to provide an improvement to the above-described lift mechanism, the primary object of which is to simplify the manufacture of said mechanism and to facilitate the application of the system to low-lift pallet trucks of different Widths.
  • the improvement according to the invention essentially consists in providing the lifting cross-shaft with a constant noncircular cross-section along its entire useful length between the end bearings and in mounting the top and bottom levers of the link-rod system by forcibly fitting the ends of said levers over said non-circular cross-section.
  • FIG. l is a simplified view in side elevation of a lowlift pallet truck
  • FIG. 2 is a plan view of the link-rod system
  • FIG. 3 is a detail view on a larger scale, this view being taken in cross-section along the line III-III of FIG. 2.
  • the low-lift pallet truck is mainly of conventional design. It comprises a frame with two longitudinal members or fork arms 1 which are supported at one end on casters 2 and joined together at the other end by a bridge 3 which is supported on an elevating unit 4, said elevating unit being carried on a guide-Wheel axle 5.
  • the elevating unit 4 is constituted by a jack which is supplied from a pump actuated by a draw-bar 6.
  • the bridge 3 is supported by a pivot-pin 7 on the jack of the elevating unit 4.
  • the link-rod system ⁇ comprises a lifting cross-shaft 8 which, in accordance with the invention, has a hexagonal cross-section and is rotatably mounted at each end in bearing-bushes 9 which are rigidly fixed to the frame.
  • a top lever or pitman 10 and a bottom lever or pitman 11 which are provided for this purpose with terminal openings of ⁇ corresponding cross-sectional configuration.
  • the end of each upper lever 10 is pivoted on a pin 12 carried by one end of a cross-member 13 which is supported by the axle 5 by means of a thrust-bearing which permits the pivotal motion of said axle and of the elevating unit 4 with respect to said cross-member 13 as initiated by the operating handle 16.
  • each bottom lever 11 is pivotally ⁇ coupled to one end of a transmission link-rod 14 which extends along the corresponding fork larm 1.
  • the other end of said transmission link-rod is pivotally coupled to one end 15a of an elbowed lever 15 and a fork-arm caster 2 is -rotatably mounted at the other end 15b of said elb owed lever 15 which is pivoted on a spindle 16, said spindle being in turn rotatably mounted on the fork arm.
  • the novelty of this invention lies in the structural design of the lifting cross-shaft 8 and of the levers 10 and 11 which are forcibly fitted on said cross-shaft, thereby securing the advantages which have been set forth in the introductory part of this specification.
  • both the lifting shaft and lever end-passages can be endowed with a noncircular cross-sectional configuration other than hexagonal and that any detail modifications can be contempalted without thereby departing either from the Scope or the spirit of the invention.
  • a low-lift pallet truck having a frame with two laterally spaced, longitudinally extending lifting members and a bridge xedly connected between said lifting members adjacent one end thereof, casters mounted on said lifting members adjacent the other end thereof, a guidewheel axle connected to said frame land having a guide wheel thereon for supporting the bridge end of said truck,
  • said linkage means including pivot shaft means mounted on said frame adjacent each of said lifting members and a pair of first lever members positioned on the opposite sides of said truck adjacent said laterally spaced lifting members with one end of each of said rst lever members being interconnected to said elevating means and the other end of each of said first lever membe-rs being nonlrotatably secured to said pivot shaft means, said linkage means further including a pair of second lever members positioned on the opposite sides of said truck adjacent said laterally spaced lifting members with one end of each of said second lever members being nonrotatably secured to said pivot shaft means, a pair of intermediate rods connected between the other end of said pair of second lever members and said casters, and arm means pivotally mounting said casters on said lifting members with said arm means being pivotally connected to said rod members, the improvement wherein said pivot shaft means comprises a single cross-shaft extending between said laterally spaced lifting members with the opposite ends of said

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Forklifts And Lifting Vehicles (AREA)
  • Handcart (AREA)
  • Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
  • Automatic Cycles, And Cycles In General (AREA)

Description

Jan. 14, 1969 G. M. DUGELAY 3,421,775
LOW-LIFT PALLET TRUCK Filed Feb. e. 1967 United States Patent O 3,421,775 LOW-LIFT PALLET TRUCK George Michel Dugelay, ChatenayMalabry, France, assignor to Saxby, Paris, France, a corporation of France Filed Feb. 6, 1967, Ser. No. 614,157 Claims priority, applicatior; France, Feb. 23, 1966, 5 8
U.S. Cl. 280-43.12 1 Claim Int. Cl. B62b 3/00 ABSTRACT 0F THE DISCLOSURE The present invention -relates to small handling machines of the type commonly referred to as low-lift pallet trucks, these machines being frequently provided with fork arms which are intended to be inserted beneath loads, pallets or skids for the purpose of lifting them slightly and displacing them rover short distances.
Low-lift pallet trucks of known types generally cornprise a frame having two longitudinal members or fork arms which are fitted at one end with casters and joined together at the other end by a bridge, said bridge being supported on an elevating unit which is carried by a guide-wheel axle.
The lifting action is performed by means of a link-rod system ycomprising a lifting cross-shaft which is rotatably mounted at each end on the truck frame and on each side of which are keyed respectively a top lever and a bottom lever, the end of said top lever being pivoted about a pin carried by the guide-wheel axle and the end of said bottom lever being pivotally coupled to one end of a transmission link-rod extending along the corresponding longitudinal member whilst the other end of said transmission rod is adapted to actuate a system for lifting and lowering casters relatively to the truck frame, with the result that the longitudinal members `are lifted on the casters when the elevating unit lifts the bridge from the guide-wheel axle.
The `aim of this invention is to provide an improvement to the above-described lift mechanism, the primary object of which is to simplify the manufacture of said mechanism and to facilitate the application of the system to low-lift pallet trucks of different Widths.
The improvement according to the invention essentially consists in providing the lifting cross-shaft with a constant noncircular cross-section along its entire useful length between the end bearings and in mounting the top and bottom levers of the link-rod system by forcibly fitting the ends of said levers over said non-circular cross-section.
As Ia consequence, keys are no longer required and a free lchoice is permit-ted in the positions 0f said levers along the length of the lifting cross-shaft, with the result that the assembly can readily be adapted to the width of the corresponding elements of the pallet truck. These advantages in turn permit of simplification in both machining and I:assembly and therefore a reduction in cost price without in any way affecting the ruggedness of the mechanism as a whole.
One form of execution of the invention is shown 3,421,775 Patented Jan. 14, 1969 ICC by way of example in the accompanying drawings, in which:
FIG. l is a simplified view in side elevation of a lowlift pallet truck;
FIG. 2 is a plan view of the link-rod system; and
FIG. 3 is a detail view on a larger scale, this view being taken in cross-section along the line III-III of FIG. 2.
The low-lift pallet truck is mainly of conventional design. It comprises a frame with two longitudinal members or fork arms 1 which are supported at one end on casters 2 and joined together at the other end by a bridge 3 which is supported on an elevating unit 4, said elevating unit being carried on a guide-Wheel axle 5.
The elevating unit 4 is constituted by a jack which is supplied from a pump actuated by a draw-bar 6. The bridge 3 is supported by a pivot-pin 7 on the jack of the elevating unit 4.
The link-rod system `comprises a lifting cross-shaft 8 which, in accordance with the invention, has a hexagonal cross-section and is rotatably mounted at each end in bearing-bushes 9 which are rigidly fixed to the frame. There are fitted on each side of said cross-shaft 8 a top lever or pitman 10 and a bottom lever or pitman 11 which are provided for this purpose with terminal openings of `corresponding cross-sectional configuration. The end of each upper lever 10 is pivoted on a pin 12 carried by one end of a cross-member 13 which is supported by the axle 5 by means of a thrust-bearing which permits the pivotal motion of said axle and of the elevating unit 4 with respect to said cross-member 13 as initiated by the operating handle 16. The end of each bottom lever 11 is pivotally `coupled to one end of a transmission link-rod 14 which extends along the corresponding fork larm 1. The other end of said transmission link-rod is pivotally coupled to one end 15a of an elbowed lever 15 and a fork-arm caster 2 is -rotatably mounted at the other end 15b of said elb owed lever 15 which is pivoted on a spindle 16, said spindle being in turn rotatably mounted on the fork arm.
It is already known that, when the jack of the elevating mechanism 4 lifts the bridge 3 and is supported on the guide-wheel axle 5, it initiates the simultaneous pivotal motion of the top levers 10 and bottom levers 11 on the one hand and of the elbowed levers 15 on the other hand, the pivotal motion of the top and bottom levers being transmitted to the elbowed levers by the link-rod 14, with the result that the frame as a whole moves upwards parallel to itself.
The novelty of this invention lies in the structural design of the lifting cross-shaft 8 and of the levers 10 and 11 which are forcibly fitted on said cross-shaft, thereby securing the advantages which have been set forth in the introductory part of this specification.
It will be readily yapparent that both the lifting shaft and lever end-passages can be endowed with a noncircular cross-sectional configuration other than hexagonal and that any detail modifications can be contempalted without thereby departing either from the Scope or the spirit of the invention.
What I claim is:
1. In a low-lift pallet truck having a frame with two laterally spaced, longitudinally extending lifting members and a bridge xedly connected between said lifting members adjacent one end thereof, casters mounted on said lifting members adjacent the other end thereof, a guidewheel axle connected to said frame land having a guide wheel thereon for supporting the bridge end of said truck,
means and said casters for raising the other end of said truck in response to raising of the bridge end of the truck, said linkage means including pivot shaft means mounted on said frame adjacent each of said lifting members and a pair of first lever members positioned on the opposite sides of said truck adjacent said laterally spaced lifting members with one end of each of said rst lever members being interconnected to said elevating means and the other end of each of said first lever membe-rs being nonlrotatably secured to said pivot shaft means, said linkage means further including a pair of second lever members positioned on the opposite sides of said truck adjacent said laterally spaced lifting members with one end of each of said second lever members being nonrotatably secured to said pivot shaft means, a pair of intermediate rods connected between the other end of said pair of second lever members and said casters, and arm means pivotally mounting said casters on said lifting members with said arm means being pivotally connected to said rod members, the improvement wherein said pivot shaft means comprises a single cross-shaft extending between said laterally spaced lifting members with the opposite ends of said cross-shaft being pivotally connected to said pair of lifting members, the portion of said cross-shaft extending between said lifting members having a uniform noncircular cross section and the ends of said pairs of first and second lever members having noncircular openings substantially identical in size and shape to the cross-section of said `cross shaft for nonrotatably securing said pairs of first and second lever members to said cross-shaft.
References Cited UNITED STATES PATENTS 1,891,658 12/1932 Thomas 74-548 3,188,107 6/1965 Quayle 2SC-43.12 3,188,698 6/1965 Zoll et al 74-519 BENJAMIN HERSH, Primary Examiner.
ROBERT R. SONG, Assistant Examiner.
US614157A 1966-02-23 1967-02-06 Low-lift pallet truck Expired - Lifetime US3421775A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR50778A FR1475891A (en) 1966-02-23 1966-02-23 Development of pallet trucks

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US3421775A true US3421775A (en) 1969-01-14

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DE (1) DE1942676U (en)
ES (1) ES336451A1 (en)
FR (1) FR1475891A (en)
GB (1) GB1163456A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3612564A (en) * 1970-01-16 1971-10-12 Allis Chalmers Mfg Co Lift linkage for walkie lift truck
WO1983003579A1 (en) * 1982-04-20 1983-10-27 Np Marketing Corp Cargo restraining device
EP1413496A1 (en) * 2002-10-25 2004-04-28 Italcarrelli Srl Lifting and transportation device with a flat loading bed
US20040099486A1 (en) * 2002-11-22 2004-05-27 Gramatikov Ivan K. Fork height adjustment mechanism
US20050116432A1 (en) * 2002-02-20 2005-06-02 Hans-Peter Borrmann Pallet truck
US20060125196A1 (en) * 2004-12-15 2006-06-15 Grand Steer Inc. Steering device for pallet truck
US20090279994A1 (en) * 2008-05-07 2009-11-12 Ivan Kirilov Gramatikov Fork assembly lift mechanism
US20120305867A1 (en) * 2010-02-17 2012-12-06 lLIFTER S.R.L. Transpallet
US8336913B1 (en) 2009-05-07 2012-12-25 Grand Steer Inc. Steering device for pallet jack
US9522816B2 (en) * 2015-05-05 2016-12-20 Kenneth Taylor Apparatus and method for moving catalyst bins

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1891658A (en) * 1930-11-15 1932-12-20 Westinghouse Air Brake Co Locking means for rotatable elements
US3188107A (en) * 1962-05-17 1965-06-08 Yale & Towne Inc Lift truck
US3188698A (en) * 1960-12-01 1965-06-15 Wilson J G Corp Safety device for vertically movable doors

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1891658A (en) * 1930-11-15 1932-12-20 Westinghouse Air Brake Co Locking means for rotatable elements
US3188698A (en) * 1960-12-01 1965-06-15 Wilson J G Corp Safety device for vertically movable doors
US3188107A (en) * 1962-05-17 1965-06-08 Yale & Towne Inc Lift truck

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3612564A (en) * 1970-01-16 1971-10-12 Allis Chalmers Mfg Co Lift linkage for walkie lift truck
WO1983003579A1 (en) * 1982-04-20 1983-10-27 Np Marketing Corp Cargo restraining device
US4515506A (en) * 1982-04-20 1985-05-07 N P Marketing Corporation Pallet cargo restraining device
US20050116432A1 (en) * 2002-02-20 2005-06-02 Hans-Peter Borrmann Pallet truck
US7296806B2 (en) * 2002-02-20 2007-11-20 Borrmann Gmbh Pallet truck
EP1413496A1 (en) * 2002-10-25 2004-04-28 Italcarrelli Srl Lifting and transportation device with a flat loading bed
US20040099486A1 (en) * 2002-11-22 2004-05-27 Gramatikov Ivan K. Fork height adjustment mechanism
US7191872B2 (en) 2002-11-22 2007-03-20 The Raymond Corporation Fork height adjustment mechanism
US7226060B2 (en) 2004-12-15 2007-06-05 Grand Steer Inc. Steering device for pallet truck
US20060125196A1 (en) * 2004-12-15 2006-06-15 Grand Steer Inc. Steering device for pallet truck
US20070284838A1 (en) * 2004-12-15 2007-12-13 Grand Steer Inc. Steering device for pallet truck
US20080042381A1 (en) * 2004-12-15 2008-02-21 Grand Steer Inc. Pallet jack
US7427075B2 (en) 2004-12-15 2008-09-23 Grand Steer Inc. Steering device for pallet truck
US7475887B2 (en) 2004-12-15 2009-01-13 Grand Steer Inc. Pallet jack
US20090279994A1 (en) * 2008-05-07 2009-11-12 Ivan Kirilov Gramatikov Fork assembly lift mechanism
US8336913B1 (en) 2009-05-07 2012-12-25 Grand Steer Inc. Steering device for pallet jack
US20120305867A1 (en) * 2010-02-17 2012-12-06 lLIFTER S.R.L. Transpallet
US9051161B2 (en) * 2010-02-17 2015-06-09 Pr Industrial S. R. L. Transpallet
US9522816B2 (en) * 2015-05-05 2016-12-20 Kenneth Taylor Apparatus and method for moving catalyst bins

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Publication number Publication date
DE1942676U (en) 1966-07-21
FR1475891A (en) 1967-04-07
ES336451A1 (en) 1968-01-01
GB1163456A (en) 1969-09-04

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