EP0220968B1 - Continuously working hydraulic linear winch - Google Patents

Description

The present invention relates to a linear hydraulic winch for continuous operation, comprising a fixed frame in the form of a support plate, a first and a second pair of hydraulic cylinders which extend perpendicular to the support plate and whose fixed elements are fixed to said plate, a first and a second traction blocks, which are connected to the mobile elements of the first and second pairs of hydraulic cylinders respectively.

Linear hydraulic winches are well known. They are either of the intermittent operating type (see patent FR 2 498 169) or of the continuous operating type (see FIG. 1 of the appended drawings which schematically represents such a continuously operating winch). With equal traction forces and equal strokes of hydraulic cylinders, known winches with continuous operation have the disadvantage of having a larger overall length than that of winches with intermittent operation. This is due to the fact that in continuously operating winches, the two traction blocks are mounted movable in the winch frame, and to the fact that an additional pair of hydraulic cylinders is provided to move that of the two traction blocks which is usually fixed in an intermittent winch. On the other hand, as their name suggests, the winches with continuous operation have the advantage of making it possible to obtain a continuous movement of the cable, therefore of the load, on which they act.

The present invention therefore aims to provide a linear hydraulic winch with continuous operation which has, at equal traction forces and equal strokes of the hydraulic cylinders, a lengthwise dimensions of the same order of magnitude as that of known linear hydraulic winches operating intermittent.

However, there is already known from patent FR-2 167 951 a linear hydraulic winch with continuous operation, according to the preamble of claim 1, which is relatively compact.

However, in the device represented in FIGS. 2 and 3 of this French patent, the two support members 9 and 10 and the two pairs of hydraulic cylinders 21 and 22 are located on the same side of the support plate 25, only the carrier member 10 being located between the cylinders of the four jacks 21 and 22. The carrier member 9, when active, is supported on a shoe 11 which itself is supported on a transverse piece 27 whose ends are respectively fixed to the piston rods 24 of the two cylinders 22. Likewise, the carrier member 10 is supported on a shoe 12, which itself is supported on the bottom of a U-shaped part 26, the branches of which are respectively fixed to the piston rods 23 of the cylinders 21.

Although, in principle, the lifting and lowering device shown in FIGS. 2 and 3 of this French patent makes it possible to vertically move the rod 8 and the load attached to it almost continuously, such a known device has however, some drawbacks. Indeed, in service, depending on whether the carrier member 9 or 10 is active for carrying the rod 8 and the load, it cannot be avoided that the part 27 or 26 is deformed by bending under the weight of the load. It cannot therefore be avoided that significant bending moments are applied to the piston rods 24 of the cylinders 22 or to the piston rods 23 of the cylinders 21. It follows that, if a lifting and lowering device was actually produced in accordance with the figures 2 and 3 of patent FR-A 2 167 951, the piston rods 23 and 24, the guide members associated therewith with cylinders 21 and 22 and the sealing members associated with said piston rods and with the pistons of said cylinders would, in service, subject to rapid and prohibitive wear, incompatible with prolonged use of the lifting and lowering device. This device should therefore be stopped frequently to replace worn parts. Frequent stops would not only be inconvenient for the operation of the lifting and lowering device, but they would also increase the operating and maintenance costs in a prohibitive manner.

The aforementioned drawbacks are practically eliminated when two annular cylinders 31 and 32 are used, which concentrically surround the rod 8 as shown in FIGS. 4a to 4e or 5a to 5g or 6a to 6d of the aforementioned French patent or even two annular cylinders 11 as shown in GB-A 2 153 316. However, in this case, an extremely long structure is necessarily obtained.

The present invention precisely makes it possible to obtain a winch structure as compact as that of FIGS. 2 and 3 of document FR-A 2 167 951, while greatly reducing the bending stresses applied in service to the piston rods of the cylinders of the two pairs. of cylinders and, consequently, while greatly reducing the wear of the fixed and mobile parts which are in mutual contact, relative to the device of FIGS. 2 and 3 of French patent FR-A 2 167 951.

To this end, the linear hydraulic winch of the present invention is characterized in that the first and second traction blocks are arranged respectively on either side of the support plate, each of said first and second traction blocks being located between the cylinders of the two cylinders, respectively, of one of the two pairs of cylinders and fixed directly to the movable elements of the first or of the second pair of cylinders, respectively.

• La figure 1 montre schématiquement, en élévation, un treuil hydraulique linéaire connu à fonctionnement continu.
• La figure 2 montre, en perspective, une première forme d'exécution du treuil hydraulique linéaire de la présente invention.
• La figure 3 montre, en élévation, le treuil hydraulique linéaire de la figure 2.
• La figure 4 est une vue en coupe suivant la ligne IV-IV de la figure 3.
• La figure 5 est une vue du treuil hydraulique linéaire suivant la flèche F de la figure 2.
• La figure 6 montre, à plus grande échelle et en coupe verticale l'un des deux blocs de traction du treuil hydraulique linéaire des figures 2 à 5.
• La figure 7 est une vue en coupe suivant la ligne VII-VII de la figure 6.
• La figure 8 est une vue en coupe suivant la ligne VIII-VIII de la figure 7.
• Les figures 9 à 11 montrent trois autres formes d'exécution du treuil hydraulique linéaire de la présente invention.
• La figure 12 montre, à plus grande échelle, un détail de la figure 9.

The invention will now be described in detail with reference to the accompanying drawings in which:

• Figure 1 shows schematically, in elevation, a known linear hydraulic winch with continuous operation.
• Figure 2 shows, in perspective, a first embodiment of the linear hydraulic winch of the present invention.
• Figure 3 shows, in elevation, the linear hydraulic winch of Figure 2.
• FIG. 4 is a sectional view along line IV-IV of FIG. 3.
• FIG. 5 is a view of the linear hydraulic winch along the arrow F in FIG. 2.
• FIG. 6 shows, on a larger scale and in vertical section, one of the two traction blocks of the linear hydraulic winch of FIGS. 2 to 5.
• Figure 7 is a sectional view along line VII-VII of Figure 6.
• FIG. 8 is a sectional view along line VIII-VIII of FIG. 7.
• Figures 9 to 11 show three other embodiments of the linear hydraulic winch of the present invention.
• FIG. 12 shows, on a larger scale, a detail of FIG. 9.

The known linear hydraulic winch shown in FIG. 1 comprises a fixed frame 1, of rectangular shape, formed by two beams 1a and 1b braced at their ends by crosspieces 1c and ld which are drilled in the middle of a hole 2 through which passes a cable 3. Two traction blocks 4 and 5 are respectively fixed to movable crosspieces 6 and 7, the ends of which can slide in the longitudinal members 1 _- a and 1b. The cross member 6 can be moved back and forth with the traction unit 4 by a pair of hydraulic cylinders 8, the cylinders of which are fixed to the cross member 1c. Similarly, the cross member 7 can be moved back and forth with the traction unit 5 associated with it by a pair of hydraulic cylinders 9 whose cylinders are respectively fixed to brackets 11 respectively fixed to the side members 1a and 1b. Each of the two traction blocks 4 and 5 comprises two clamping members (not shown), in the form of a wedge, which, when they are selectively clamped against the cable 3, cooperate with the latter by friction to pull it.

To pull the cable 3 for example in the direction of arrow G, the two tightening members of the traction unit 4 are tightened on the cable 3 and the traction unit 4 is moved by the two hydraulic cylinders 8 in the direction of the arrow G while the traction unit 5, whose two clamping members are loose, is moved in the opposite direction to the arrow G. When the traction units 4 and 5 respectively occupy the positions shown in phantom in FIG. 1 , the two tightening members of the traction unit 5 are tightened on the cable 3 and the traction unit 5 is moved in the direction of the arrow G while the traction unit 4, the two tightening members of which are now released, is moved in the opposite direction to the arrow G, until the two traction units again occupy the positions shown in solid lines in FIG. 1. Then, the cycle described above starts again as many times as it is necessary to move d e the desired quantity the load connected to the cable 3.

In FIGS. 2 to 8, the elements of the linear hydraulic winch of the present invention, which have the same function as those of the known linear hydraulic winch of FIG. 1, are designated by the same reference numbers. The frame 1 of the linear hydraulic winch of the present invention is reduced to a single support plate 12, perpendicular to the longitudinal axis of the cable 3, which is pierced in its center with a hole 2 for the passage of said cable.

The cylinders 8a of the two hydraulic cylinders 8 and the cylinders 9a of the two hydraulic cylinders 9 are fixed to the support plate 12, the two cylinders 8a being located on one side of said plate and in a first plane perpendicular thereto. , while the two cylinders SLa are located on the other side of the plate 12 in a second plane perpendicular to said plate. Preferably, the aforementioned first and second planes are also perpendicular to each other as can be seen in particular in FIG. 5. The piston rods 8b of the two hydraulic cylinders 8 pass through the support plate 12 and are fixed directly to the traction unit 4 which is arranged between the cylinders 9a of the two hydraulic cylinders 9. Similarly, the piston rods 9b of the two hydraulic cylinders 9 pass through the support plate 12 and are fixed directly to the traction unit 5 which is disposed between the cylinders 8a of the two hydraulic cylinders 8.

With such an arrangement, a linear hydraulic winch with continuous operation is obtained, which is extremely compact. By way of example, a linear hydraulic winch produced in accordance with the present invention, having a traction capacity of 500 tonnes and having hydraulic cylinders whose stroke is 1.8 m, has an overall length of less than 5 m. By way of comparison, a known linear hydraulic winch produced in accordance with FIG. 1, having a traction capacity of 500 tonnes and hydraulic cylinders whose stroke is only 1.2 m, has an overall length of approximately 12 m .

The two traction units 4 and 5 are identical, so that only one of them will be described with reference to FIGS. 6 to 8. As shown in these figures, the traction unit 4 comprises, so known, a frame or body 13 having four walls two by two perpendicular defining an elongated passage with rectangular cross section, in which are arranged two clamping members 14 in the form of a wedge, between which the cable passes 3. Each of the two clamping members 14 has, in known manner, an outer surface 14a which is sloping relative to the longitudinal axis of the cable 3, and can roll, by means of a set of rollers 15, on the inner surface 16a of a support piece 16 which is rigidly fixed to the body 13 and whose inner rolling surface 16a has a slope identical to that of the surface 14a of the corresponding clamping member 14. Thus, any relative movement of the two clamping members 14 relative to the body 13 causes, in the direction of said movement, the clamping or loosening of the cable 3 by said clamping members 14.

Means are further provided for synchronizing the movements of the two clamping members 14, for moving them between their respective clamping and loosening positions shown in FIGS. 6 and 8, and for keeping the two clamping members 14 in their position Clamping. Usually, these three functions are performed by separate elements, at least some of which are located outside the traction unit. According to a preferred embodiment of the present invention, these three functions are performed by a single auxiliary hydraulic cylinder 17 located inside the body 13 of the traction unit 4. As shown in FIGS. 6 and 8, the piston rod 17a of the jack 17 has a length substantially equal to that of the body 13, and it is fixed at each of its ends to a block 18 itself rigidly fixed to the body 13. In the middle of the piston rod 17a is rigidly fixed a piston 17b. The "cylinder" 17c of the jack 17 has a cross section whose outer profile is square as is more particularly visible in Figure 7. The "cylinder" 17c is partially engaged in two rectangular cavities 19 which face each other and which are respectively formed in the clamping members 14. Each of the two cavities 19 has a length equal to that of the "cylinder" 17c so that the ends of the latter are in contact with the end faces of the cavities 19. A fluid under pressure can be admitted into the “cylinder” 17c on the left side of the piston 17b (seen in FIG. 6) through a hole 21 drilled radially in the piston rod 17a near the piston 17b, through an axial passage (not shown) of the piston rod 17a through a line 22 connected to the left end of said piston rod. Similarly, the pressurized fluid can be admitted into the “cylinder” 17c on the right side of the piston 17b through a hole 23 drilled radially in the piston rod 17a, through another axial passage (not shown) formed in the rod piston 17a and through a line 24 connected to the right end of said piston rod. With such an arrangement, when the pressurized fluid is admitted into the “cylinder” 17c through the line 22, the “cylinder” 17c is moved to the left (seen in FIG. 6) and, because it is nested in the cavities 19 of the two clamping members 14, it moves the latter, in a strictly synchronous manner, towards their clamping position. Conversely, when the pressurized fluid is admitted into the “cylinder” 17c through the pipe 24, the “cylinder” 17c is moved to the right (seen in FIG. 6) and it brings with it, in a strictly synchronous manner, the two clamping members 14 towards their release position, in which they can be maintained for as long as desired while maintaining the pressure in the pipe 24.

In the three embodiments shown in Figures 9 to 11, the elements which are identical or which play the same role as those of Figures 2 to 8 are designated by the same reference numbers.

In the winches shown in Figures 9 and 10, the two traction blocks 4 and 5, the first pair of jacks 8 and the second pair of jacks 9 are arranged in the same plane perpendicular to the plate 12, the traction block 4 and the two jacks 8 being located on one side of the plate 12, while the two jacks 9 and the traction unit 5 are located on the other side of the plate 12. In the winch of FIG. 9, the rods piston 8b and 9b of the four cylinders 8 and 9 are fixed to the plate 12, while in the winch of Figure 10, the cylinders 8a and 9a of the four cylinders 8 and 9 are fixed to the plate 12. Preferably, in the winch of Figure 9, the piston rods 8b of the two cylinders 8 are respectively aligned with the piston rods 9b of the two cylinders 9, and the aligned piston rods 8b and 9b are constituted by a rod 25 which is common to two cylinders 8 and 9 and which is fixed in the middle to the plate 12. For this purpose, as shown in Figure 12, each e rod 25 passes through a hole 26 in the plate 12 and is provided in its middle with a flange 27 which is held axially in abutment against a shoulder 28 by a threaded ring 29 screwed into the hole 26. In addition, the body 13 of each of the two traction blocks 4 and 5 of the winch of FIG. 9 has two blind cylindrical holes 31 which are closed, on the side of the plate 12, by an annular plug 32 serving as a guide for the rod 25, and in which slide the pistons of the two cylinders 8 or 9 respectively.

Similarly, the cylinders 8a of the two cylinders 8 of the winch of FIG. 10 are respectively aligned with the cylinders 9-a of the two cylinders 9, and the aligned cylinders are constituted by a cylindrical body 33 which is common to two cylinders 8 and 9 and which is fixed in the middle to the plate 12 by means similar to those shown in FIG. 12 and already described with respect to the rod 25. The internal bore of the cylindrical body 33 is provided in the middle with a partition transverse separating the chambers of the two jacks 8 and 9. In addition, in the winch of FIG. 10, the body 13 of each of the two traction blocks 4 and 5 comprises, at its end furthest from the plate 12, two parts 34 which extend laterally in opposite directions and to which the piston rods 8b or 9b of the jacks 8 or 9 are fixed respectively.

In the winch of Figure 11, the two traction blocks 4 and 5, the two cylinders 8 and the two cylinders 9 are arranged in a similar manner to that shown in Figure 2, but the four cylinders 8 and 9 are more long. In this case, the cylinders ELa and 9a of the cylinders pass through holes 35 in the plate 12 and are fixed substantially in their middle to said plate 12 by means similar to those shown in FIG. 12 and already described in connection with the rod 25. In addition, the piston rods 8b and 9b of the cylinders 8 and 9 of the winch of FIG. 11 are fixed to projecting lateral parts 34 of the body of the traction blocks 4 and 5, respectively, in a manner similar to that shown in Figure 10.

Although this is not shown in FIGS. 9 to 11, each of the traction units 4 and 5 may include an auxiliary cylinder similar to the cylinder 17 shown in FIGS. 6 to 8, to move the clamping members 14 synchronously between their tightening and loosening positions.

It goes without saying that the embodiments of the present invention which have been described above have been given by way of purely indicative and in no way limitative examples, and that numerous modifications can be easily made by those skilled in the art. art without departing from the scope of the present invention as claimed. Thus in particular that, instead of being produced in the form of a molded block, the body 13 of each of the two traction blocks 4 and 5 can be constituted by several elements assembled to each other.

Claims (13)

1. A continuously operating hydraulic linear winch, comprising a fixed structure (1) in the form of a support plate (12), first and second pairs of hydraulic actuators (8 and 9) which extend perpendicularly to the support plate and of which the stationary elements (8a and 9a; 8b and 9b) are secured to said plate, first and second traction units (4 and 5) which are connected to moving elements (8b and 9b; 8a and 9a) of the first and second pairs of hydraulic actuators (8 and 9) respectively, characterised in that the first and second traction units (4 and 5) are disposed respectively on either side of the support plate (12), each of said first and second traction units (4 and 5) being situated between the cylinders (8a or 9a) of the two actuators (8 or 9), respectively, of one of the two pairs of actuators and being secured directly to the moving elements (8b or 9b; 8a or 9a) of the first or second pair of actuators (8 and 9), respectively.

2. A hydraulic linear winch according to claim 1, characterised in that the first pair of actuators (8) is disposed in a first plane perpendicular to the support plate (12), in that the second pair of actuators (9) is disposed in a second plane perpendicular to the support plate (12), in that the piston rods (8b or 9b) of each pair of actuators (8 or 9) are secured to the traction unit (4 or 5) associated therewith, whereas the cylinders (8a or 9a) of each pair of actuators (8 or 9) are secured to the support plate (12) and extend at least partly on the opposite side of said plate in relation to the traction unit (4 or 5) associated therewith, and in that each of the two traction units (4 or 5) is disposed between the cylinders (9a or 8a) of the pair of actuators (9 or 8) associated with the other traction unit (5 or 4).

3. A hydraulic linear winch according to claim 2, characterised in that the cylinders (8a or 9a) of each pair of actuators (8 or 9) are wholly situated on the opposite side of the support plate (12) in relation to the traction unit (4 or 5) associated therewith.

4. A hydraulic linear winch according to claim 2, characterised in that the cylinders (8a or 9a) of each pair of actuators (8 or 9) pass through apertures (35) in the support plate (12) and are secured substantially at their centre to said plate (12), and in that each of the two traction units (4 or 5) comprises, at its end most remote from the suppor plate (12), two portions (34) which extend laterally in opposite directions and to which are secured the piston rods (8b or 9b) of the pair of actuators (8 or 9) associated therewith.

5. A hydraulic linear winch according to any one of claims 2 to 4, characterised in that the second plane is perpendicular to the first plane.

6. A hydraulic linear winch according to claim 1, characterised in that the two traction units (4 and 5) and the first and second pairs of actuators (8 or 9) are disposed in one plane perpendicular to the support plate (12), the first traction unit (4) and the first pair of actuators (8) being situated on the side of said plate (12), whereas the second traction unit (5) and the second pair of actuators (9) are situated on the other side of said support plate (12).

7. A hydraulic linear winch according to claim 6, characterised in that the piston rods (8b and 9b) of the four actuators (8 and 9) are secured to the support plate (12).

8. A hydraulic linear winch according to claim 7, characterised in that the piston rods (8b) of the first pair of actuators (8) are aligned respectively with the piston rods (9b) of the second pair of actuators (9), and in that the aligned piston rods (8b and 9b) are formed as a rod (25) which is common to the two actuators (8 and 9) respectively of the first pair and second pair of actuators and which is secured at its centre to the support plate (12).

9. A hydraulic linear winch according to claim 8, characterised in that each of the two traction units (4 and 5) comprises blind cylindrical holes (31) which are closed, on the side of the support plate (12), by an annular plug (32) serving as a guide for said rod (25) and in which slide respectively the pistons of the actuators (8 or 9) of one of the two pairs of actuators.

10. A hydraulic linear winch according to claim 6, characterised in that the cylinders (8a and 9a) of the four actuators (8 and 9) are secured to the support plate (12).

11. A hydraulic linear winch according to claim 10, characterised in that the cylinders (8a) of the first pair of actuators (8) are aligned respectively with the cylinders (9a) of the second pair of actuators (9), and in that the aligned cylinders (8a and 9a) are formed by a cylindrical body (33) which is common to two actuators (8 and 9) respectively of the first pair and second pair of actuators and which is secured at its centre to the support plate (12).

12. A hydraulic linear winch according to claim 10 or 11, characterised in that each of the two traction units (4 and 5) comprises, at its end most remote from the support plate (12), two portions (34) which extend laterally in opposite directions and to which are secured the piston rods (8b or 9b) of the pair of actuators (8 or 9) associated therewith.

13. A hydraulic linear winch according to any one of claims 1 to 12, in which each of the two traction units (4 and 5) comprises a body (13) having two opposite inner surfaces (16a) inclined relative to the longitudinal axis of the body (13) and two wedge-like clamping members (14), each of which has an outer surface (14a) having the same inclination as one of the two inner surfaces (16a) of the body (17) (sic) so that a relative longitudinal movement of the two clamping members in relation to the body (13) causes, in accordance with the direction of said relative movement, the clamping or release by said clamping members (14) of a cable (3) with which the hydraulic winch is intended to cooperate, characterised in that each of the two traction units (4 and 5) also comprises an auxiliary hydraulic actuator (17) whose "cylinder" (17c) is partly enclosed in two mutually facing cavities (19) formed respectively in the two clamping members (14) and of a length equal to that of the "cylinder" (17c) of the actuator (17), and of which the piston rod is secured at each of its ends to the body (13) of the traction unit.

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