FR2497785A1 - LIFTING MECHANISM FOR FORKLIFT - Google Patents

Abstract

THE MECHANISM CONSISTS OF A MAST CONSISTING OF AN EXTERNAL SECTION 3 AND AN INTERNAL SECTION 4, A LIFTING APRON 1, AND HYDRAULIC LIFT ASSEMBLIES FOR MOVING SECTIONS 3, 4 RELATIVE TO THE OTHER. SECTION 3 IN THE FORM OF A CHASSIS OPENED AT ITS UPPER END AND SHAPED BY GUIDE BEAMS 5 WHICH ALSO CONSTITUTE HOUSING 24 FOR THE HYDRAULIC LIFT ASSEMBLIES, AS WELL AS BY CROSSERS 7, 8 CONNECTING THE BEAMS 5 TO THEIR PART LOWER, THE CROSSMER 7 IS CONSTITUTED BY A PIPE ALLOWING TO SUPPLY THE HYDRAULIC ASSEMBLIES WITH FLUID UNDER PRESSURE. SECTION 4 HAS THE FORM OF A CHASSIS OPEN AT ITS LOWER END. SECTIONS 3, 4 INCLUDE GUIDING ELEMENTS AT THEIR OPEN END. THE BEAMS 5 HAVE A SECTION COMPOSED OF A PART IN O AND A PART IN U. IMPROVEMENT OF VISIBILITY ON THE LIFT TRUCKS.

Description

The present invention relates to a lift mechanism for

  electric or thermal-powered forklift trucks, tractors and the like, incorporating lift masts, and other types of

mechanical handling.

  A known lift mechanism for a forklift includes a mast having an outer section into which a section is incorporated.

  interior. A lifting apron is mounted to move relative to the sec-

  interior by means of flexible support means passing over rollers

  supported by the inner section. The second end of these flexible means

  xibles is fixedly connected to the outer section. Two hydraulic units

  The lifting beams are connected to the mast sections and are mounted on columns. The outer and inner sections of the masts represent

closed structures.

  The main drawback of this known embodiment lies in the fact that it narrows the driver's visual field due to a large section of the hydraulic columns and lift assemblies and the presence of cross members connecting the vertical beams of the mast sections. . In addition, the many components such as hydraulic cylinders, joists and sleepers, make it difficult to mount and adjust

  components between them and increases the weight of the whole.

  The present invention proposes to realize a lifting mechanism

  which is simpler and offers a wider field of view to the driver.

  The invention solves this problem by providing a lifting mechanism whose outer section of the mast forms an open frame at its upper end and comprises guide beams whose lower ends are connected by cross members. The guide beams are profiled

  at the same time to be used as housing for hydraulic lift assemblies

  one of the sleepers serving at the same time as a supply duct

  in oil for these sets. The lifting members of the two elevated assemblies

  are connected at their upper end to the upper end of the inner section of the mast. The inner section of the mast represents an open frame at the base. The two inner and outer sectionsinclude, at their open ends, external guide elements. The guiding legs of the outer section of the mast have a section which is a combination of a part

  at 0 and a U-shaped part, the part at 0 being situated outside with respect to

  The present invention offers the following advantages - an enlargement of the driver's field of view through the lift mechanism, because the guide beams of the outer section of the mast have been combined with the hydraulic lift assemblies - a reduced number of components of the mast sections;

  - a decrease in the weight of the lift mechanism.

  Other features and advantages of the invention will emerge

  of the description which will be given hereinafter with reference to the accompanying drawings

wherein:

  FIG. 1 is a perspective view from the rear of a mechanism

  me elevator according to the invention; - Figure 2 is a sectional view along the line N-N of Figure 1;

  FIG. 3 is a front perspective view of the mechanism

  shown in Figure I; - Figure 4 is a sectional view along the line K-K of Figure 3;

  FIG. 5 is a schematic representation of the elevated mechanism

  tor of the invention, which highlights the magnification of the visual field B of the driver; - Figure 6 is a sectional view of the outer section of the mast of the mechanism of Figure I; and

  FIG. 7 is a sectional view of a guide beam of the section

the mast.

  The lifting mechanism of the invention comprises a lifting apron 1,

  chains 2, an outer mast section 3 and an integral mast section

4.

  The outer section 3 of the mast comprises two guide beams 5 which also constitute housings 24 for the hydraulic lifting assemblies, and two crosspieces 7 and 8 connecting the lower part of the guide beams 5. The section of the guide beams 5 is composed of a part in 0 10 externally connected to a U-shaped portion 11. Inside the housing 24 of the two guide beams 5 are housed the movable members of the hydraulic lifting assemblies. A pipe 9 and the crossbar 7, the latter having the shape of a pipe, are used to power the hydraulic lift assemblies

in fluid under pressure.

  The inner section 4 of the mast consists of two beams 12 connected at their upper end by a cross member 13. The inner section

  4 of the mast is connected to the elevator members 6 by supports 20.

  The guide beams 5 of the outer section 3 of the mast support

  at their upper part, rollers 14 acting in the direction of the arrow C, rollers 15 providing lateral guidance and act in the directions of the arrows Aa and Ab, as well as guide supports 16 acting

  in the directions of the arrows Ba and Bb.

  The beams 12 of the inner section 4 of the mast support, at their lower part, rollers 17 acting in the direction of the arrow C, rollers 18 providing lateral guidance in the directions Ba and Bb,

  as well as guide supports 19 acting in the directions Aa and Ab.

  The chains 2 are connected by one of their ends to the lifting apron 1 by supports 21 and their other end to the outer section 3 of the mast by other supports 22, these chains passing over

  pulleys 23 mounted on axes provided on the inner section 4 of the mast.

  The field of view of the driver through the lifting mechanism B is limited in height only by the upper cross member 13 and linking the beams of the inner section 4 of the mast and the lower rail 7

  3. The field of vision B is limited in width only.

  by the columns constituted by the beams 12 of the inner section

  4 and by the beams 5 of the outer section 3.

  The operation of this lifting mechanism is as follows: the pressurized fluid is introduced through the pipe 9 and the crossbar 7 into the recesses 24 of the hydraulic lifting assemblies of the guide beams 5 the outer section 3 of the mast so as to lift the elevating members 6 and the inner section 4 of the mast. The ascent of the inner section 4 of the mast of the forklift also results in the lifting of the apron 1 thanks to the action

  chains 2 passing on the pulleys 23.

Claims (2)

  1. Lift mechanism comprising a mast composed of an outer section   and an inner section relative to which a lifting apron is mounted to move, this apron being connected to flexible support members passing on pulleys fixed to the inner section of the mast, the other end of the flexible elements being invariably connected to the outer section of the mast, this mechanism also comprising hydraulic lifting assemblies respectively connected to the columns of the mast sections, characterized in that the outer section (3) of the mast has the form of a frame open at its end upper and formed by guide beams (5) which also constitute housings (24) for the hydraulic lifting assemblies, as well as crosspieces (7, 8) connecting the beams (5) to their lower part, one of the cross-members being constituted by a pipe for supplying pressurized fluid with hydraulic lifting assemblies whose parts   elevators (6) are connected at their upper end to the upper end.   the inner section (4) of the mast, the latter having the shape of a   open frame at its lower end, the outer sections (3) and   the upper part (4) of the mast having at its open end guide elements (16, 19) located outside with respect to the columns constituted by the   beams of the inner and outer sections of the mast.   Elevating mechanism according to claim 1, characterized in that the guide beams (5) of the outer section (3) of the mast have a section composed of an O-shaped portion (10) and a U-shaped portion ( 11), the part in O (10)   being located outside with respect to the U-shaped portion (11).