FR2522752A1 - Piece goods conveyor hydrostatic bearing - has piston in housing with separate seal, accommodating goods on piston crown - Google Patents

Abstract

The hydrostatic support bearing is for a piece goods conveyor with a cushion of liquid. Pressurised liquid is delivered into a chamber enclosed by a bottom surface and a housing and with a seal round the chamber periphery. A piston (3) is accommodated in the housing (1), the goods transported being mounted on its crown, while there is a separate seal between the piston and housing. The seal enclosing the cushion at the periphery of the chamber (2) is rigidly fixed to the housing. It can be in the form of a ring of elastic material, with a flange on its side towards the supporting surface (8).

Description

HYDROSTATIC SUPPORT AND DEVICE

HANDLING OF LOADS ON CUSHION

LIQUID USING THIS SUPPORT.

  The present invention relates to means for handling charges on a liquid cushion and relates to

  in particular a hydrostatic support and a control device

  Nutention of charges on liquid cushion, using this support. The hydrostatic support proposed can be used to move heavy and bulky loads over short distances, and on a horizontal bearing surface

  or inclined, smooth and waterproof, used to obtain the sewn

sin liquid.

  This hydrostatic support can be used for example-

  ple inside workshops and inside the factory

  to move large ol: metal dets and structures,

  tone or other material In some cases, the devices taking advantage of the hydrostatic support offered can replace conventional handling equipment such as cranes The hydrostatic support offered can be

  advantageously used to move structures

  res of ships during erection on site and for

  launching from inclined holds.

  We know the use of handling devices on air cushion Experience shows that in many cases such devices are more

  economical than conventional trucks or platform-

  One of their essential advantages is

  in that they allow easy movement of far-

  water in any direction With the increase-

  tion of the load to be transported on an air cushion, difficulties are encountered If the devices are used

  at low air pressure, the de-

  bit of air and therefore the value of the compressor power per ton of the load to be moved will be very

  high which translates into large energy costs

  gie per ton of load By increasing the pressure

  we can see that the devices in question

  -2- tooth of their stability Problems arise for the choice of material for speakers, and for the desired height

  of hoisting the load above the bearing surface.

  To solve these problems, we proposed to replace

  cer the air cushion by a liquid cushion for example a water cushion The liquid cushion allows to make

  significantly increase the specific pressure on the

  displacement face (bearing surface) up to kgf / cm 2 and more It is obvious that the carrying capacity of a device on a water cushion is greater

  to that of an air cushion device having the same

my dimensions.

  Liquid cushion handling devices generally include several hydrostatic supports, high pressure pumps, supply hoses,

  control and measuring devices The essential element

  tiel of these devices is constituted by the hydrostatic supports (often called "water bearing") which make

  the subject of this description.

  We know of a hydrostatic support for a device for moving loads on a liquid cushion which includes a body

  constituted by a small platform provided, on its

  lower rimeter, of an elastic enclosure ("skirt").

  Through holes made in this body, we

  ject water inside the enclosure as long as the water pressure does not exceed that exerted by the load on the platform At the moment of the equality of these pressures, an oer_ taine quantity Water carlenoe to be scalded under the "skirt" around the entire perimeter by creating a film of carrier water

  then apply a small tensile force to dep-

  tie the load in the desired direction The hydro support

  static just described receives water from

  a pump which can be installed at a certain distance

  this and connected to the support by means of a hose The use of a single support does not guarantee the absolute stability of

  the load to be moved, so we distribute the mass of the far-

of water at least on three supports.

  The implementation of the hydrostatic support of this system requires a large water flow (60 l / min for a load capacity of 60 t), which significantly limits

its possibilities of exploitation.

  A much smaller liquid flow characterizes another known hydrostatic support The body of this support

  has a cavity communicating with the liquid source

  of and used to form, with the bearing surface, a liquid cushion; and a groove concentric with said

  cavity and housing a flexible seal The groove has a sec-

  variable tion widening in the direction of the bearing surface The seal is housed in said groove; this

  joint is hollow and has a variable section (in pear foroe).

  This seal is filled with liquid during work CO is thus

  if you can reduce the liquid flow by sending liquid

  in the groove and in the joint when the support is placed under the load but before the cushion is

  formed It occurs that the seal is pressed against the over-

  bearing face, thereby isolating the cavity where the cushion is formed, from the surrounding medium, that is to say by creating a closed circuit of the cushion. While the cushion is forming, the pressure in the seal is maintained such that the liquid does not not escape as long as the charge

  will not have been lifted to the desired height (within the limits

  support is possible) During the displacement of the load it is ensured that the ratio of pressures in the cushion and the joint is such that a thin film is formed under the joint The thickness of this film, which is also adjustable, is to be maintained so that it is possible to move the load with an effort

  of traction with an insignificant flow of liquid.

  The use of the hydrostatic support which has just been described makes it possible to significantly reduce the flow of liquid in the cushion. However, the manufacture and

  implementation of this support cause certain diffi-

  cultured mainly due to the fact that the joint

  waterproof delimiting the sudden liquid cushion, by means of

  body, the important part of the weight of the

  load, which limits the possibility of hooking-

  -4- be the load carrying capacity of the support and requires a joint

  waterproof very resistant, s Gold, and made of a sufficient material

  flexible This tight seal is therefore of a fairly com-

  folded and it is bulky In addition, to keep the film thickness at the desired value, a constant connection of the groove must be provided, sheltering the joint

  waterproof, with high pressure liquid source.

  The present invention aims to develop a hydrostatic support and a device for handling loads on a liquid cushion, using this support, which make it possible to reduce the action of the load on the joint.

  waterproof of the body delimiting the cushion along the peri

  * meter, to the extent that it is possible to use

  ser in said seal a sealing element of the so-called type

  '"end" without increasing the d 6 bit of liquid in the cushion.

  According to the invention, the hydrostatic support of the device for handling charges on a liquid cushion comprises, to move the surface

  supporting the load with respect to a bearing surface,.

  means for operatively creating a liquid cushion by discharging the liquid into a cavity formed by the bearing surface and a body, a tight seal being provided to delimit the cushion along the perimeter of the said cavity, and it is characterized in that , in the body, a piston is provided on the end face of which the load to be moved is disposed, said piston being provided with its own seal which seals the space between the body and the piston, while

  the seal delimiting the liquid cushion along the peri-

  end of the cavity is secured to the body of the support.

  Such an embodiment of the hydrostatic support

  of the load handling device on liquid cushion

  of reduces the action that the load to move

  exerts on the joint delimiting the following liquid cushion

  before the perimeter to such an extent that it becomes

  possible to use, in said joint, a sealing element

  flexible "end" type without increasing the liquid flow rate of the cushion which simplifies the structure of the joint and makes it possible to increase the load capacity of the support

without increasing its sizes.

-5-

  It is advantageous that the joint limiting the neck

  sin liquid along the perimeter of the cavity is fa-

  made of elastic material under the shape of a ring with an annular projection on its bearing surface facing the bearing surface The fixing of this joint can be carried out quite simply by vulcanization (in

  For this purpose, it is advantageous to produce a circular groove

the end of the body).

  In order to be able to quickly and easily change the seal delimiting the liquid cushion along the perimeter of the cavity in the event of wear, it is advantageous to provide said

  seal of another annular projection on its surface

  t giving the cross section of the joint a C-shape The inner surface of the body, in the area

  fixing the joint, must have an annular bead

  the area to which, using a flange connection, is

  stained the upper annular projection of the joint.

  According to another alternative embodiment of the invention-

  tion, in order to make the implementation more convenient

  re of the joint limiting the liquid cushion according to the peri

  meter of the cavity, it is advantageous to provide it with two annular projections giving the cross-section of the joint a Z-shape. An annular bead must then be provided on the external surface of the body, in the joint fixing zone, which, by means of of a flange assembly, is

  attached the upper annular projection.

  To increase the flexibility of the joint, it is

  tagous to communicate to its annular projection a form

corner in the axial section.

  To guarantee safe pressing by the supporting surface

  of the seal limiting the liquid cushion along the perimeter

  tre of the cavity, at the start of forming said liquid cushion,

  provision should be made between the piston and the surface

  body, at least one stop from the low position

  end of the piston with a shock absorber made under the

  form of at least one compression spring.

  6 - The hydrostatic support being of large dimensions, it is advantageous to produce the shock absorber in the form of at least three compression springs arranged at equal distances from each other along the circumference of the piston.

  To improve the feeding of the cavic, t N liqui-

  of, it is advantageous to provide the support with wi

  tif for controlling the piston stroke, comprising a shut-off valve mounted at the inlet of the connection for bringing the liquid into the cavity and having a closure element connected to a spring rod cooperating with the stop to close the valve stop when the liquid cushion has reached the desired height Adjustment of the cushion height is easy to achieve by providing said stem of the stop valve with a threaded end. Such an embodiment of the support allows, during the work, of

  disassemble the cushion-forming cavity from the con-

  feed feed which ensures the autonomy of the support while considerably increasing its possibilities

technological.

  It is advantageous to create a handling device.

  tion of charges on liquid cushion, in which the

   ke rests on the hydrostatic supports connected to a source of liquid to form the liquid cushion and in which each of the supports is produced according to any of the variants described above, while the

  frame rests on the pistons of these hydro supports> t-

  ticks. The invention will be better understood and other objects, details and advantages thereof will appear better on

  light of the explanatory description which follows

  different embodiments given only at ti-

  ire of nonlimiting examples with reference to the appended drawings in which: FIG. 1 represents the hydrostatic support of the device for handling charges on a liquid cushion according to the invention, seen from the side and in partial axial section; 7- Figure 2 shows in axonometry an embodiment of the seal, with parts in axial section; Figure 3 shows the attachment of the seal to the body; Figure 4 shows the fixing of the seal having the section in C; Figure 5 shows the attachment of the seal having the Z section; FIG. 6 represents an exemplary embodiment of the hydrostatic support with a spring between the piston and the body, seen from the side and in partial axial section; Figure 7 shows an example of attachment of the compression spring to the piston, by a section along VII-VII Figure 6; Figure 8 shows in section an example of attachment of the compression spring to the body; FIG. 9 represents an exemplary embodiment of the hydrostatic support with a stop valve according to the invention, according to a partial axial section; FIG. 10 shows an exemplary embodiment of the shut-off valve with the threaded end of the rod, in a vertical section; FIG. 11 represents, in vertical section, the device for handling charges on a liquid cushion,

  using the hydrostatic support according to the invention.

  It should be noted that the appended drawings bear a schematic character and are only used to illustrate exemplary embodiments of the invention without giving limitations to the dimensions of the elements forming part of the device nor to the dimensional relationships between its elements. The hydrostatic support of the device for handling loads on a cushion comprises (FIG. 1) a body 1,

  delimiting a cavity 2 (used to form the cushion li-

  quide), and a piston 3 mounted so that it can

  move vertically in the cavity 2 A watertight seal

  che 4 delimiting the liquid cushion is rigidly

  stained on the body 1 along the perimeter of the cavity 2.

8-

  The piston 3 has its own seal 5 used for sealing

  expensive space between the piston 3 and the body 1 The support, object of the invention also includes a connector 6 for supplying the liquid forming the cushion As liquid we can use water In winter, at low temperatures, frost resistant liquids such as aqueous chloride solutions should be used

  sodium, antifreeze or mineral oils.

  To reduce the friction between the bearing surface 7 of the seal 4 and the bearing surface 8, on which the hydrostatic support in question moves, it is advantageous to use aqueous solutions of soap or mineral oils.

  The bearing surface 8 must be smooth without depressing

  insignificant deformations of the ladi-

  The surface is tolerated when the liquid cushion is of a sufficient height. The bearing surface can be made of steel or plastic sheets, concrete slabs, asphalt coating, etc. For example, steel sheets can be used. '' a thickness of 3 mm placed on any smooth floor capable of supporting said

  load or on soil that has been previously compacted.

  We tolerate deformations of the sheet surface in

a margin of + 3 mm.

  FIG. 2 represents the simplest example of embodiment of the joint 4, the bearing surface of which has

  an annular projection facing the interior of the housing

  The seal 4 can be made of rubber, plastic or another elastic material.

  clearly sees an annular projection 9 on the inner surface

  seal 4 To fix such a seal the simplest is to operate by vulcanization and, to do this, we will have to practice a circular groove on the end of the joint.

body 1 (see Figure 3).

  Figure 4 shows a fragment of the hydrosta-

  tick in section where the seal is provided with another annular projection giving the seal a C-shape. Such a seal is attached using a flange assembly 10 La -9-

  inner surface of the body 1 has a bead an-

  11 which is pressed the upper annular projection

  of the seal 4 using said flange assembly 10.

  This method of attachment makes it possible to quickly and easily replace the seal. Figure 5 shows another mode of attachment of the seal provided with two annular projections 9 and therefore having the shape of a Z The annular bead 12 which, by means of the flange assembly 10, is pressed the

  upper annular projection 9, is made on the sur-

outer face of the body l.

  To increase the flexibility of the joint, we communicate

  has its annular projection, extending over the bearing surface

te, a wedge shape.

  FIG. 6 shows an exemplary embodiment of the hydrostatic support with stops for the extreme low position of the piston 3 disposed between the body 1 and the

  piston 3 According to this variant of the invention

  tion, the support is provided with a shock absorber which comprises a

  compression spring 13 or a multitude of such res-

  spells. Only one stop can be provided, as shown in

  Figure 6 It consists of an annular bead

  area 11 produced on the internal surface of the body 1 and by an annular bead 14 produced on the external surface of the piston 3 In this case, one (or more)

  compression spring 13 is installed between these fillers

  lets Other variants of the abutments are possible, or in the presence of a seal used to seal

  the space between the body and the piston the stops are made

  linked in the form of protrusions on the piston and

  es correspondents formed on the inner surface of the body Instead of these latter projections can be used an annular bead 11 Based on the information from the accompanying drawings the skilled person can perform the

  variant described above of carrying out the support

  vendique It is for this reason that said variant

is not illustrated.

  - The modes of implementation of the proposed support described

  above ensure a secure pressing against the surface

  aunt 8 of the seal 4 at the start of the formation of the cushion, which saves the liquid and the time necessary to form the cushion The compression spring 15 can

  be spiral and installed so as to surround the piston 5.

  In the case of a large support, there will be placed, between the beads 11, 14 at least three compression springs 13 having equal distances between them. These springs can be flat and attached as well to the bead 14 of the piston 35 (FIG. 7) that at the bead 11

of body 1 (Figure 8).

  FIG. 9 shows an exemplary embodiment of the hydrostatic support with a device for controlling the stroke of the piston 3, being in the form of a

  shut-off valve 15 (shown on a larger scale

  the entire support) The valve 15 is placed at the end

  trée of the connection 6 fixed to the piston 3 and connected to the cavity 2 by a channel 16 formed in the piston 3 The valve

  15 is designed in such a way that its element of iron-

  procedure 17 provided with a spring rod 18 (in contact, when

  the support is in operation, with a stop 19 fixed to the body 1) closes the valve when the liquid cushion has reached the desired height The height of the cushion can

  be easily adjusted by providing the rod 18 with the valve

  stop pe 15 of a threaded end piece 20 (Figure 10).

  Figure 10 also shows a manifold

  inlet 21 and outlet manifold 22 of the shut-off valve

  rêt In the support designed with the shut-off valve 15, the liquid cushion of the desired height is formed automatically On the other hand, the fact that

  need to maintain a constant connection between the cavi-

  tee 2 and the supply conduit ensures the

  tonomy of said support: for this it is necessary to place a stop valve (not shown) between the inlet of the valve 15 and the supply pipe. The autonomy of the support increases the possibilities considerably.

technological of it.

11 -

  Figure 11 shows a handling device.

  tion of charges on a liquid cushion, using the claimed support This device comprises a frame 23 under which the supports which have just been described have been placed, connected to a source of liquid in order to obtain a liquid cushion As a source of liquid, may use a hydraulic accumulator The drawing represents one of the alternative embodiments of the invention, according to which the frame 23 is produced in the form of a hollow body to be filled with a liquid serving to form the liquid cushion.

  In this case, the frame 23 serves, at the same time, to

  hydraulic accumulator Such an embodiment of the frame ensures the autonomy of the handling device for

charges.

  Figure 11 also shows conventionally-

  valve 24 used to let the liquid pass

towards the hydrostatic supports.

  Hydrostatic support of the handling device

  of charges on a liquid cushion works as follows.

  The hydrostatic support is placed under the load on the bearing surface 8 The piston 3 is in its position

  extreme bass and, acting through the res-

  compression spells 13, press the body 1 with the seal 4 on the bearing surface 8 (Figures 6, 9) The tubing 21 of the stop valve 15 is connected, by means

  a valve (not shown), with the discharge pipe

  which sends pressurized liquid to channel 16.

  With the arrival of the liquid the piston 3 and the charge

  tent because of what it forms, between the base of the piston 3 and the bearing surface 8, the liquid cushion (Figure 1) delimited along the perimeter by the seal 4

  and the body 1 When the load reaches the height re-

  quise, the supply of liquid is cut to the cavity 2 Then the connection between the discharge pipe and the shut-off valve is broken 15 The hydrostatic support is ready to move the load After having brought the load to its destination, we lets out the liquid from the cavity 2 12 - which causes the piston 3 to descend to its low position

starting point (see Figure 6).

  One of the operating features of the

  load handling device on liquid cushion used

  reading the proposed hydraulic support, resides in that before the mide in use, the hollow frame 23 is filled with

fluid and compressed gas.

  The use of the hydrostatic support proposed in load handling devices on a liquid cushion makes it possible to significantly increase their load capacity without increasing the dimensions and the weight of these

  devices The claimed support differs from the

  tifs analogous by a simple construction and a mode of

  easy attachment of the seal delimiting the liquid cushion.

  This allows you to easily change the worn seals.

  these particularities of the construction presented in

  make it a convenient device to handle.

  Of course other modifications may be

  made to the device which has just been described only-

  ment by way of nonlimiting example without departing from the

part of the invention.

Claims (9)

  1 Hydrostatic support of the handling device   of charges on a liquid cushion comprising, for displacement   cer the surface supporting the load with respect to a bearing surface (8), means for operatively creating a liquid cushion by pumping the liquid into a cavity (2) formed by the bearing surface (8) and a body (1) , a seal- (4) being provided to delimit the liquid cushion along the perimeter of the aforesaid cavity, characterized in that, in the body (1), there is provided a piston (3) on the end face of which is disposed the load to be moved, said piston (3) being provided with its own seal (5) which seals the space between the body (1) and the piston (3), while the seal (4) delimiting the following liquid cushion the   perimeter of the cavity (2) is integral with the body (1).   2 hydrostatic support according to claim 1, characterized in that the tight seal (4) delimiting the liquid cushion along the perimeter of the cavity (2) is made of elastic material in the form of a ring with an annular projection (9) on its support surface   facing the bearing surface (8).   3 hydrostatic support according to claim 1 or   2, characterized in that the seal (4) is vul-   channeled in a circular groove made on the end of body (1).   4 hydrostatic support according to claim 2,   characterized in that the seal (4) delimiting the neck   sin liquid according to the perimeter, has, on its sur-   inside face, another annular projection giving the cross section of the joint a C shape, the   inner surface of the body (1), in the fixing area   tion of the seal (4), being provided with an annular bead (11) to which, by means of a flange assembly (10), is   attached the upper annular projection (9) of the seal.   Hydrostatic support according to claim 2,   characterized in that the seal (4) delimiting the neck   sin liquid along the perimeter of the cavity (2), is provided with another annular projection giving its cross section a shape substantially in Z, the external surface of the body (1) being provided, in the area of   fixing the seal (4), an annular bead (12) at the   which, by means of a flange connection (10), is attached   the upper annular projection (9) of the seal.   6 Hydrostatic support according to any one of   Claims 2 to 5, characterized in that the projection   annular made along the bearing surface of the   joint has, in section, a wedge shape.   7 Hydrostatic support according to any one of   Claims 1 to 6, characterized in that between the   piston (3) and the inner surface of the body (1), is arranged at least one stop of extreme low position of the body (1) with a damper produced in the form   at least one compression spring (13).   8 hydrostatic support according to claim 7, intended for the displacement of large loads, characterized in that the damper is produced in the form of three compression springs (13) arranged   at equal distances from each other according to the piston turn (3).   9 hydrostatic support according to claim 7 or 8, characterized in that it is provided with a device   piston stroke control, including a   stop valve (15) placed at the inlet of the liquid supply fitting into the cavity (2) and provided with a closing element (17) connected to a spring rod (18) cooperating with a stop ( 19) to close the stop valve (15) during the formation of the liquid cushion of a desired height. Hydrostatic support according to claim 9, characterized in that the stem of the shut-off valve (15)   is provided with a length adjusting device (20).   11 Load handling device on necks   sin liquid in which a frame (23) rests on the hydrostatic supports communicating with a source of liquid to form the liquid cushion, characterized in that each of the hydrostatic supports is produced   according to any one of claims 1 to 10, while   that the frame (23) rests on the pistons (3) of said hydrostatic supports.