US3651891A - Hoist for lift trucks - Google Patents

Hoist for lift trucks Download PDF

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Publication number
US3651891A
US3651891A US867332A US3651891DA US3651891A US 3651891 A US3651891 A US 3651891A US 867332 A US867332 A US 867332A US 3651891D A US3651891D A US 3651891DA US 3651891 A US3651891 A US 3651891A
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US
United States
Prior art keywords
masts
cylinder
piston
pair
plate
Prior art date
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Expired - Lifetime
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US867332A
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English (en)
Inventor
Gennaro Pittaluga
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.)
FIAT SOC PER AZIONI AZIENDA OM
FIAT SOC PER AZIONI AZIENDA OM STABILIMENTO DI MILANO
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FIAT SOC PER AZIONI AZIENDA OM
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Application filed by FIAT SOC PER AZIONI AZIENDA OM filed Critical FIAT SOC PER AZIONI AZIENDA OM
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Publication of US3651891A publication Critical patent/US3651891A/en
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Expired - Lifetime legal-status Critical Current

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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
    • B66F9/08—Masts; Guides; Chains

Definitions

  • Foreign Application Priority Data trucks comprising a plate carrying forks slidable in the guides of the innermost pair of masts, the latter being slidable in the guides of the pair of movable intermediate masts sliding in turn in the grooves of the pair of fixed masts, a telescopic cylinder with two pistons, namely a smaller and a larger piston, mechanical transmission means adapted to transmit the movements from the cylinder to the plate and thereafter to the movable masts, and abutment means for carrying the pair of inten'nediate masts along, in which the smaller piston is connected to the plate to obtain, with respect to the cylinder, movements of the plate twice those of said smaller piston, and the larger piston is connected to the pair of fixed masts to obtain movements of the cylinder with respect to the fixed masts three times those of the larger piston with respect to the cylinder itself, the thrust area of the larger piston being practically one and a half times the thrust area of the smaller piston.
  • the present invention relates to a hoist for lift trucks belonging -to the class of hoists constituted by three pairs of masts, two of them movable and one fixed, which are fitted one within the other with the possibility of sliding, a plate slidable in turn along the innermost pair of masts and carrying forks and/or special fixtures employed for moving various objects, and at least one hydraulic cylinder which raises the plate and masts through mechanical transmission means, such as, for example, rollers and chains and other means, and more precisely, in a first stage, called free lift, raises the plate to the maximum height without the pairs of movable masts moving and without the cylinder itself projecting beyond the minimum overall height defined by the masts themselves in the retracted position, while in a second stage the cylinder produces with the same mechanical transmission means which take part in
  • these hoists which, as has already been said, have as their fundamental characteristic that of permitting the maximum elevation of the plate and, consequently, of the load supported thereby through the medium of the forks or other equipment without any variation in the minimum overall height of the hoist with the masts retracted, may be of the type having a plurality of single cylinders or a single telescopic cylinder.
  • the multi-cylinder type has the advantage of having the raising speed of the plate during the free lift equal to that of the plate during the raising of the movable masts, it presents the disadvantage of having a plurality of cylinders of which at least one is of a height practically equal to that of the hoist when closed, which reduces visibility for the driver in the stage of translation of the truck.
  • the type having a single telescopic cylinder may be equipped with a high cylinder or a low cylinder, there being meant by a high cylinder one with a height practically equal to that of the hoist when closed and by a low cylinder one with a height less than that of the hoist when closed.
  • a high cylinder one with a height practically equal to that of the hoist when closed
  • a low cylinder one with a height less than that of the hoist when closed.
  • hoists with a low telescopic cylinder are further more divided into hoists in which the speed of the plate during the free lift is different to that during the raising of the movable masts and hoists in which the speed remains the same in the two stages.
  • the present invention relates to a hoist of the last type, that is a hoist with a low telescopic cylinder which allows good visibility and having a constant speed of the plate, with consequent elimination of jerking or jolting of the load in the stage of transition from free lift to elevation with the masts in motion.
  • This hoist is characterized substantially in that the smaller piston is connected kinematically to the plate slidable along the guides of the pair of innermost masts through mechanical transmission means such as to obtain, with respect to the cylinder, movements of the plate (free lift) twice those of said smaller piston, and that the larger piston is connected kinematically to the pair of fixed masts through mechanical transmission means separate from those of the smaller piston and such as to obtain movements of the cylinder with respect to the fixed masts three times those of the larger piston with respect to the cylinder itself, the thrust area of the larger piston being practically one and a half times that of the thrust area of the smaller piston.
  • FIGS. 1, 2 and 3 show respectively from the side, in diagrammatic form, the hoist fully lowered, the hoist with the forks at maximum free lift and the hoist with the forks at maximum elevation, while FIGS. 4 and 5 are two front views of a practical embodiment of the same hoist mounted on a lift truck, the hoist being fully lowered and at maximum elevation, respectively; and
  • FIG. 6 is a side view of the hoist of FIGS. 4 and 5 partly in section.
  • the reference 1 indicates the hydraulic cylinder equipped with two plunging pistons 2, 3 fitted one within the other and both contained in the cylinder.
  • the piston 2 of larger diameter is inserted at the bottom, while the piston 3 of smaller diameter is inserted at the top.
  • the cylinder 1 is fixed to the inner pair of movable masts 4.
  • the ratio between the thrust areas of the two pistons is 1.5
  • the cap or head 5 of the smaller piston 3 is equipped with one or more pulleys 6 on which are placed the chains 7 which are anchored at one end to the cylinder 1 and support at the other end the plate with the forks 8, which move at a speed twice that of said piston 3 (FIG. 2).
  • the head or cap 9 of the piston 2 of larger diameter is equipped with pulleys 10 and anchorages 11 cooperating by means of other chains 12 separate from the first-mentioned chains with other pulleys 13 mounted towards the bottom of the cylinder.
  • the last-mentioned chains are anchored to the upper end of the fixed masts 14, then passed at the bottom round the pulleys 10 at the head of the piston in the grooves of said pulleys and over half the circumference thereof and ascend and pass at the top round the pulleys 13 (mounted towards the bottom of the cylinder) in the grooves of said pulleys and over half the circumference thereof, being finally fixed by their ends to the anchorages 11 with which the head 9 is provided.
  • the raising action begins with the plate and forks 8 slidable along the innermost masts 4 by the action of the upwardly directed piston 3, while the pairs of movable masts 4 and 15 remain stationary until such time as the plate engages with the upper part of the innermost masts 4 at 16.
  • the movable masts will be lowered first and, only when these have completed their travel, will it be possible for the plate and the forks 8 to be lowered along the innermost masts.
  • a hoist comprising, in combination:
  • first and second telescoping piston members movably extending from said cylinder inopposite direction, wherein the thrust area of one of said first and second piston members is one and one-half times the thrust area of the other of said first and second piston members; and wherein the movement of said load-carrying plate with respect to said cylinder is approximately twice as great as the movement of said second piston with respect to said cylinder;
  • said first flexible means being trained at least partially around said first and second pulleys
  • said second flexible means being trained at least partially around said third pulley.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Forklifts And Lifting Vehicles (AREA)
US867332A 1969-08-08 1969-10-17 Hoist for lift trucks Expired - Lifetime US3651891A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2072469 1969-08-08

Publications (1)

Publication Number Publication Date
US3651891A true US3651891A (en) 1972-03-28

Family

ID=11171113

Family Applications (1)

Application Number Title Priority Date Filing Date
US867332A Expired - Lifetime US3651891A (en) 1969-08-08 1969-10-17 Hoist for lift trucks

Country Status (6)

Country Link
US (1) US3651891A (sv)
AT (1) AT302181B (sv)
DE (1) DE1952386A1 (sv)
FR (1) FR2057611A5 (sv)
GB (1) GB1255987A (sv)
YU (1) YU31629B (sv)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4458785A (en) * 1982-10-25 1984-07-10 Bushnell Jr Sherman W Lift
US4493397A (en) * 1982-08-06 1985-01-15 Nissan Industrial Equipment Co. Fork lift trucks
US4701097A (en) * 1986-09-22 1987-10-20 Fmc Corporation Rear platform lift
US20080302601A1 (en) * 2007-06-06 2008-12-11 Andrew Baker Lift assembly

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2812102A1 (de) * 1978-03-20 1979-09-27 Jungheinrich Kg Hubgeruest fuer hubgeraete
NL189558C (nl) * 1978-08-14 1993-05-17 Asea Ab Hefinrichting voor vorkhefvoertuigen.
SE420591B (sv) * 1979-09-03 1981-10-19 Kalmar Last Maskin Verkstad Ab Anordning vid ett mastformigt, teleskopiskt forlengbart lyftstativ till en motordriven truck
SE422574B (sv) * 1980-06-03 1982-03-15 Asea Ab Trippelstativ for gaffeltruckar
FR2578235B1 (fr) * 1985-03-01 1988-04-01 Fenwick Linde Chariot de manutention comprenant un mat de levage constitue de trois elements
GB2264282B (en) * 1992-02-20 1995-04-12 Lansing Linde Ltd Lift trucks and extensible mast structures therefor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918143A (en) * 1957-12-19 1959-12-22 Towmotor Corp Triple telescopic high free lift truck
US3208556A (en) * 1962-02-19 1965-09-28 Towmotor Corp Multiple stage masts for lift trucks
US3252545A (en) * 1963-02-27 1966-05-24 Eaton Yale & Towne Industrial truck

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918143A (en) * 1957-12-19 1959-12-22 Towmotor Corp Triple telescopic high free lift truck
US3208556A (en) * 1962-02-19 1965-09-28 Towmotor Corp Multiple stage masts for lift trucks
US3252545A (en) * 1963-02-27 1966-05-24 Eaton Yale & Towne Industrial truck

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4493397A (en) * 1982-08-06 1985-01-15 Nissan Industrial Equipment Co. Fork lift trucks
US4458785A (en) * 1982-10-25 1984-07-10 Bushnell Jr Sherman W Lift
US4701097A (en) * 1986-09-22 1987-10-20 Fmc Corporation Rear platform lift
DE3730415A1 (de) * 1986-09-22 1988-04-07 Fmc Corp Flugzeugbeladevorrichtung
US20080302601A1 (en) * 2007-06-06 2008-12-11 Andrew Baker Lift assembly

Also Published As

Publication number Publication date
GB1255987A (en) 1971-12-08
YU31629B (en) 1973-08-31
FR2057611A5 (sv) 1971-05-21
AT302181B (de) 1972-10-10
DE1952386A1 (de) 1971-03-04
YU261769A (en) 1973-02-28

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