FR2684656A1 - LIFTING GEAR. - Google Patents

Abstract

Lifting device for lifting equipment such as service vehicles (e.g. three-wheel mowers, four-wheel vehicles, motorized outdoor service equipment, etc.) for inspection, maintenance and servicing repair. The lifting apparatus includes mutually spaced lifting beams (12, 14) and wheel lifting devices (35, 40, 42, 45) carried by the beams. The wheel lifters are movable along the beams and preferably also transverse to the beams and can engage the wheels (102, 103) of the vehicle even when the vehicle is not aligned parallel to the beams. As the beams rise, the wheel lifters cause the vehicle to lift. Access to the underside of the vehicle is free and all parts of the vehicle or its components (eg cutting blades, etc.) can be accessed. The lifting apparatus preferably includes releasable locking elements, to prevent the beams from descending.

Description

LIFTING GEAR

  The present invention relates to a lifting device for lifting equipment in order to allow its inspection, maintenance and repair. More particularly, the present invention relates to a motorized lifting device which is particularly suitable for lifting.

  motorized equipment for outdoor service, vehicles

  games, utility vehicles, etc. Mowing equipment for golf courses and other industrial mowers requires

  typical of frequent interventions (e.g. daily

  inspection, adjustment, maintenance or repair of the various components It is very difficult to access

  to all components of the equipment without lifting the

  equipment or sliding under it The usual chain hoists or gantries are not suitable for lifting most types of motorized equipment because there are normally no easily accessible parts of the chassis to which several chains can be attached for

  lifting In addition, the equipment may not be supported

  stably tied by chains.

  In addition, the gantries and elevators known for automobiles are not adaptable to the lifting of a

  equipment such as commercial mowers (e.g.

  full of three-wheel mowers) or various other types

  equipment that does not have a chassis with the-

  which of the lifting arms of a conventional gantry can

  cleverly engage Gantry cranes or elevators

  usual do not have the types of adjustment that

  needed to allow the lifting of various types of motorized equipment Bridges or gantries that include arms that extend under a vehicle to be lifted require that the arms reach and engage the chassis of the vehicle Although this is possible when lifting ordinary motor vehicles, this is difficult or impossible to achieve when

  try to lift various types of motorized equipment.

  In addition, it is difficult to align an equi-

  motor vehicle, such as commercial mowers, with a gantry crane or a standard elevator of the type intended for lifting automobiles. This makes the use of gantries or elevators even more difficult or painful.

  usual for lifting equipment such as large-

  its mowers, three-wheeled vehicles, etc.

  Hoists, jacks and other types of ap-

  similar have been used in the past for various lifting functions. Reference may be made, for example, to the hoists described in US Patents 2,099,636,

  2,564,267, 3,734,466, 4,058,293, 4,196,887 and 4,856,618.

  Other lifting devices are also described

  in U.S. Patents 4,793,593, 4,540,329 and 2,840,248.

  None of these gantry cranes and lifting devices

  Known ge is not entirely suitable or practical for lifting and supporting irregularly shaped vehicles and certain types of motorized equipment (for example three-wheeled vehicles such as mowers) In addition, gantry or bridge systems which are intended for lifting automobiles and garden tractors or the like usually require that

  the vehicle is very carefully aligned with the device

  lifting eye to be lifted If the vehicle is not properly aligned, the lifting mechanism cannot engage the vehicle, or the weight of the

  vehicle is not properly balanced on the

  lifting me This situation can be very dangerous

  since the vehicle may slip or fall from the elevation

  which can damage the vehicle and injure workers who may be under the vehicle or

near this one.

  Some of the known lifting systems are also

  improperly because they include rails,

  platforms or other lifting structure which

  tends under the vehicle Such a structure can hinder the necessary access to the lower part of the vehicle

  for inspection, maintenance or repair functions

  tion. Although ramps are sometimes used to support a vehicle in an elevated position, it can be very dangerous In addition, the elevation obtained

with ramps is limited.

  To date, no lifting device has been produced which is suitable or practical for the safe and efficient lifting of motorized equipment for external service (for example, three-wheel mowers, utility vehicles, vehicles

games, etc.).

  The subject of the present invention is an apparatus for

  lifting eye which is particularly suitable for

  vehicle and equipment (for example,

  three-wheeled dower) for inspection, maintenance and repair The lifting device is particularly useful for lifting and supporting equipment such as large commercial mowers and

  other types of external service motorized equipment

  laughing, which cannot be lifted and supported

  safe by means of gantry cranes and car lifts

  common bile The device is also suitable for lifting and supporting vehicles such as trolleys

  golf, game vehicles, etc. In a reali-

  sation of the invention, the lifting device is suitable for lifting a three-wheeled vehicle, the device having a free entry passage and lifting means which easily adapt to the vehicle so

  that the vehicle can be driven quickly and conveniently

  in the device, without having to align the vehicle

  with the longitudinal axis of the lifting device The ap-

  similar can easily adapt to vehicles of different

different mensions.

  According to the invention, in one embodiment, the lifting device comprises: (a) two substantially horizontal lifting beams

  which are transversely spaced from each other

  so as to leave a free entry passage

  bre for the vehicle; (b) two side wheel lifting elements, each of which is easily attached to one of the beams

  lifting, to engage a side wheel

  of the vehicle, each lifting element of

  side wheel - can be moved longitudinally -

  along a respective lifting beam, so as to easily adapt to vehicles of different dimensions and to a poor vehicle

  aligned with the longitudinal axis of the ap-

  the same; (c) a third wheel lifting member for engaging and lifting the third wheel of the vehicle; and (d) lifting means for raising the two lifting beams and the third element of

  wheel lifting, to lift the vehicle.

  The apparatus according to the present invention is very easy to adapt and it can be used for the safe and efficient lifting of motorized equipment and vehicles of various types and styles.

  wheel lifting elements can be moved longitudinally

  Lement, and preferably also transversely, with respect to the lifting beams The equipment or the vehicle need not be aligned parallel to the lifting beams The wheel lifting elements can be moved and positioned so that they correctly and desiredly engage the wheels of the equipment to be lifted, regardless of

  misalignment between the vehicle and the device.

  The lifting device according to the present invention is suitable for safe and efficient lifting

  a wide variety of vehicles and motorized equipment

  laughing stock (for example, commercial mowers, vehicles

  three-wheeled and four-wheeled cules,

  golf, play vehicles, etc.) The device does not require

  site not access to the vehicle or team chassis-

  to safely lift it, and no special alignment is required to allow

  the hoist to operate In addition, the hoist

  lifting eye does not require vertical adjustment of arms or suspensions to properly engage

  with the vehicle or equipment to be lifted.

  The lifting device is very open and you can easily drive a vehicle to insert it

  in the region between the lifting beams.

  After bringing wheel lifting elements into engagement with the wheels, the vehicle can be lifted to the height

  desired The underside of the vehicle is completely open or

  green and accessible to allow inspection, maintenance

  maintenance and repair of the vehicle In other words, the ap-

  similar lifting does not hinder access to the lower face

re of the vehicle.

  The present invention also provides

  lifting methods, lifting forks and methods

  of fixing the lifting forks to a lifting beam. The invention is described below in more detail.

  detailed, with reference to the attached drawings on the-

  which the same references designate the same parts in the various views, and in which:

  Figure 1 is a perspective view illus-

  trant one embodiment of a lifting apparatus

  form with the invention (before fixing the lifting elements of side wheels); Figure 2 is a perspective view of the lifting apparatus of Figure 1, a large mower of the

  trade being placed between the lifting beams in pre-

  preparation for lifting by the device; Figure 3 is a top view illustrating a way in which the apparatus can drive and support a large commercial three-wheel mower for lifting functions even when the mower is not aligned parallel to the lifting beams;

  Figure 4 is a perspective view illus-

  a large commercial mower that is securely supported in the elevated position to allow an operator to inspect, maintain and repair components under the mower;

  Figures 5 A to 5 D illustrate a pre-

  embodiment of a wheel lifting fork which can be used in the present invention;

  FIG. 6 illustrates a preferred embodiment of

  cable system and hydraulic cylinder, use

  for the movement of the lifting beams;

  Figure 7 is a top view of the track

  pours that connects the upper ends of the two sup-

  vertical ports; Figures 8 A to 8 C illustrate a preferred method of attaching the cables to a vertical slide for moving one of the lifting beams; Figure 9 is a side view showing one of the lifting beams and one of the uprights; Figure 10 is a section along the line -10 of Figure 9;

  Figure 11 is a partial elevational view-

  cut from one of the uprights, representing the

  releasable security lock tif;

  Figure 12 is a perspective view illus-

  still operating the ver-

  security rusting; Figure 13 is a bottom view of a mode

  production of a tray which can be used in the

  vention; Figure 14 is a section of the tray along line 14-14 of Figure 13; Figure 15 is a section of the tray along line 15-15 of Figure 13;

  Figure 16 is a side view of the end

  upper half of one of the uprights;

  Figure 17 is a side view of the end

  top half of the other amount;

  FIG. 18 shows the control levers

  accessible on one of the uprights of the device;

  Figure 19 shows the ver-

  security rust on the other upright; Figure 20 is a side view of one of the

  uprights, representing openings for observation

  tion of the equalization bar to which the lifting cables are attached;

  Figures 21 A and 21 B show the installation

  lation of a photocell and a reflector which can be used in a lift signaling system in the high position; Figure 22 illustrates one way in which a leg of the post can be attached to the floor; Figure 23 shows the lower end of one of the uprights;

  Figure 24 is a perspective view illus-

  trant another embodiment-of a suspension

  fork which can be used in the present invention

  tion Figure 25 is an end view illustrating another embodiment of a lifting beam and a

  fork suspension, which can be used in the pre-

  invention; Figures 26 A and 26 B are elevational views

  illustrating the operation of the protection system

  foot tion; FIG. 27 is a perspective view of an embodiment of a hydraulic cylinder usable in the present invention; and

  Figures 28 A and 28 B are elevational views.

  tion and in section representing a preferred mode of realization

  sation of a hydraulic relief valve which is used

  readable in the apparatus of the present invention.

  Reference is made to FIG. 1 which represents an embodiment of a lifting device 10 in accordance with the present invention. The device comprises elongated and mutually spaced lifting beams 12 and 14,

  vertical supports or uprights 16 and 18 and a tra

  pour 19 Bases 15 and 17 are attached to the ends

  lower mounts of uprights 16 and 18, respectively.

  The bases can be bolted to the floor of the workshop.

  link or the building in which the appliance is to be used

  lifting eye, if desired This is illustrated in figure 22, in which a 17 A bolt is used to fix the base 17 to a floor 11 Due to the bolting of the device to the floor, the device is extremely stable and prevented from moving or tilting Depending on the length of the bases 15 and

  17, it may not be necessary to fix them to the floor.

  The lifting beams are transversely spaced from each other, so that a large open area is defined between the beams and a vehicle to be lifted can be brought quickly and conveniently into

  this area There is no need to align the vehicle

  rolls with the lifting beams or with the longitudinal axis

  nal of the device The longitudinal axis is defined as being the axis perpendicular to the plane defined by the two uprights When the lifting beams are mutually parallel, the longitudinal axis of the lifting device

is parallel to the beams.

  In the lifting device illustrated on the

  drawings, the lifting beams are mutually parallel

  parallel but they can be non-parallel if desired For example, the rear ends of the lifting beams can be inclined towards each other The rear ends of the beams can even be connected to each other, if Preferably, the

  lifting beams are horizontal, as shown.

  Each lifting beam is preferably

  attached to a vertical slide 20 which is retained so

  sliding in a respective upright The upper end

  of each slide is attached to a system of

lifting cables.

  As shown in Figure 10, the amount

  is of tubular type and has a wide, long slot

  lengthwise, along its length 20 A pads are pre-

  ference attached to opposite edges of the slide for him

  substantially give the interior dimensions of the world

  So long, the lifting beam is prevented from lowering

  stumble, twist or turn relative to the world

  as long as the lower end of each upright preferably has a crossbar or rod fixed at this location so as to maintain the desired dimension for the upright. This is illustrated in FIG. 23, where a bar 16 A is fixed at the lower end of

amount 16.

  The lifting cable system includes

  preferably two cables 21 and 22 which are attached to each

  that slide through an equalizer bar

  sation 23 The equalization bar is attached to the end

  upper part of the slide by means of a 23 A bolt

  in such a way that the equalizer bar can pi-

  vote around its center, as shown in Figures 8 A to 8 C, for example In the case where one of the

  cables is faulty (for example due to a break

  re or loosening), the other cable still supports the beam This is a safety feature

  additional Figure 20 shows openings

  res 16 A, arranged in the upright 16, which allow

  observe whether the equalization bar 23 is in position

  horizontal tion, which indicates that the two cables

  are still properly connected and operational.

  Figures 5 A to 5 B illustrate a pre-

  wheel lifting device, usable in the present invention The wheel lifting device

  shown includes a lifting fork 40 to which

  is fixed an elongated tail 42 The fork has mutually spaced branches or bars 40 A La

  length of branches and distance between branches

  ches can vary as desired, in order to receive any size of wheel The branches or bars of the fork can engage in a sliding way

  with a vehicle wheel to be lifted, front and rear

  of the wheel footprint, that is to say that one branch of the fork extends along the ground in front of the wheel and the other branch slides on the ground behind the wheel. wheel is defined as the part of the wheel in contact with the ground There is no need to lift the wheel of the vehicle so that the

fork comes into engagement with it.

  The tail 42 extends opposite the fork

  , as illustrated The length of the tail 42 can

  The diameter and configuration of the cross-section

  tail tail may also vary

i 11

  The tail is square or rectangular in section.

  The lifting fork is detachably connected or fixed to one of the lifting beams, by means of a suspension 45 comprising a body which has opposite arms 46 and 47 When the suspension is fixed to the lifting beam, the arm 46 leans against

  one side of the beam and the arm 47 bears against the

  tre side This is best illustrated in Figure 5 B. Preferably, the lifting beams have a non-circular cross section, so that the suspension (to which the lifting fork is attached) does not rotate towards the equipment to be lifted when lifting the lifting beams As illustrated, a rectangular cross section of the lifting beams

  lifting is very suitable.

  be a square or other polygonal or non-circular section for the lifting beams If you

  uses a beam with a circular section, then the above

  board must be bolted, pinned or keyed to the

  lifting beam to prevent angular rotation

unwanted milk.

  As shown in FIGS. 5 A and 5 B, the lower end of the arm 46 of the suspension preferably comprises a lip 46 A which passes under the lower edge of the lifting beam The lip 46 A (a) prevents the suspension 45 to mount directly and (b) prevents the suspension 45 from being partially placed on the end of the beam 12 or 14 The end of each lifting beam preferably comprises a

  raised end part (for example 12 A and 14 A).

  Since the vertical dimension of the end portions 12 A and 14 A is greater than the vertical dimension between the lip 46 A and the bars 49 of the suspension, the suspension cannot be completely fixed to the outer end of the lifting beams This

  safety feature prevents attaching the hanger

  sion only partially at the end of the beam.

  The upper part of the suspension body includes a receiving part for slidingly receiving the tail 42 of the fork. The receiving device has an upper section 48 which prevents the tail 42 from moving upwards and away from the beam A 48 A handle can be secured to the

bar 48.

  Thus, an angular movement or a rotation of the suspension 45 with respect to the lifting beam, in the direction of the equipment to be lifted, is prevented by the opposing arms 46 and 47 which engage with the opposite sides of the beam The angular movement or rotation of the tail 42 relative to

  the beam is prevented by means of the bar 48 extends

  dant above the tail 42 The tail is supported,

  on its lower surface, by means of the trans-

  versales 49 Thus, the tail 42 is very stably supported in the suspension 45, so as to resist the downward force which is applied to the

fork 40.

  The tail 42 is slidably received

  in suspension 45 in such a way that the posi-

  transverse or lateral position of the tail relative to the suspension is easily adjusted, as necessary, in order to slide the forks 40 A (a) around a wheel 102 of a vehicle to be lifted, or (b) to move them away wheel 102 after completion of maintenance or

vehicle repair.

  The longitudinal position of the suspension relative to the lifting beam can be adjusted

  by lifting the fork and the con-

  nected from the tail upwards (as shown on

  Figure 5 A) then simple sliding of the hanger

  sion 45 along the beam to the desired position.

  Then lower the fork and the tail, so that the suspension 45 again engages with the opposite sides of the beam (Figure 5 B) When a weight is applied to the fork, the suspension tightens the beam strongly and does not slide along it The suspension also prevents the fork from tilting

down.

  Since the position of the forks in relation to the lifting beams is adjustable both in the

  longitudinal direction and in the trans- direction

  side or side, the forks can be brought to any required position on the beams in order to properly attack the wheels of the vehicle, whatever

  the position of the vehicle in relation to the beams of the

  vage This is very well illustrated in top view on

  Figure 3, which shows a large mower of the

  merce 100 positioned between beams 12 and 14 The mower is not aligned parallel to the beams or to the longitudinal axis of the lifting device and

* however the forks can easily and conveniently-

  ment engage with the side wheels 102 of the mower. Although you can attach another fork to one of the lifting beams in order to engage

  and lift the wheel 103 from the mower, you can also

  Also use a lifting plate 35 which is supported

  between the beams Preferably, the position of the plate

  sheet 35 relative to the beams is adjustable For example

  ple, the beams may have a plurality of mutually spaced holes 13 along their upper surface A handle 36 provided at each end of the plate preferably has an end or pin 36 A directed downwards, which can engage in a hole

  13 at the desired location along the beam, as shown

  very on Figures 14 and 15 This prevents the tray

to slide relative to the beams.

  When we want to lift vehicles in four

  wheels, two wheels can be placed on the

  then use two forks to attack and lift

  to the other two wheels Alternatively, you can use

  use a separate fork for lifting each wheel.

  Figures 14 and 15 illustrate another characteristic of the lifting plate. An edge 35 A of the plate extends to the floor 11 when the lifting beams are in their lowered position, in order to facilitate the rolling of a wheel of a vehicle on platform The opposite edge 35 B of the platform does not extend down to the floor This avoids pinching a worker's feet under the edge 35 B when

  lowers the beams Each side edge of the platform

  wears a raised rib to help retain the

wheel on the pan.

  Another characteristic is a bar 38 for protecting the toes or feet, which extends along the platform. It is pivotally mounted at

  each of its ends The bar 38 extends slightly-

  towards the front of the platform If a worker's foot is

  hit by the bar 38 when the lifting beams

  ash, the bar 38 pushes the worker's foot away from the underside of the edge 35 B of the tray This is illustrated in Figures 26 A and 26 B.

  When the vehicle is lifted by the device

  reil, workers can easily access any

  the underside of the vehicle, for inspection,

  Yours and Repair For example, when the vehicle is a large commercial mower (as illustrated, for example, in Figure 4), a worker can access the functional components of the machine (for example, the rotor and the cutting blades) without having to crawl under the machine As illustrated, the worker can sit on a swivel stool and work on the machine in a comfortable position.

  an inspection, maintenance or repair of a

very efficient and convenient.

  A hydraulic cylinder 24 is carried by the tra-

  verse 19 The jack 24 is supplied by a hydrau-

  lique comprising an electric motor 27, a tank

  oil 29, a hydraulic pump 31 with check valve

  return, a valve body 32 and a control rod 33 The tank has an end plate 37

  and a 37 A oil level indication window

  24 A piston ge is movable between an ex-

  tension and a retracted position Pulleys 26 are attached to the outer end of the piston rod 24 A. The cables 21 and 22 are attached between their ends

  by bolts 25 and the cables pass around the

  lees 26 and 28 A strand of each cable descends into the upright 16 and is attached to an equalization bar 23

  and to the slide 20, as illustrated in FIG. 6 The

  strand of each cable passes around the pulley 28, then along the crossbar 19 and over a pulley 30, after which it descends into the upright 18 and is attached

  an equalizer bar and a slide. When the piston rod 24 A of the cylinder 24 is

  retracted into cylinder 24, cables 21 and 22

  place the two lifting beams upwards This has

  of course the effect of raising everything that is

  jogged by the forks and the lifting plate Since the 24 A piston rod is retracted in the cylinder for

  lifting the beams, there is no need for

  serve as separate guide elements for the piston rod

  tone The tension on the cables maintains correct alignment of the rod with the cylinder Since the strands

  of each cable are attached to the lifting beams op-

  posed via the equalization bars,

  the force due to the load acting on each of the

  lees 26 is balanced In addition, this arrangement allows

  use standard small hydraulic cylinders.

  The lifting device also preferably includes a releasable safety locking system,

  to prevent the lifting beams from falling accidentally

  dentically and undesirably when they wear

  the security system includes a rack

  1st fixed to one of the slides (or directly to a

  lifting beam) Preferably, a rack is

  attached to each of the slides The rack is ali-

vertically hindered.

  Figures 11 and 12 illustrate a pre-

  security lock féré used in this

  te invention The rack comprises projections or benches 50 which are spaced from each other and aligned vertically In the embodiment shown, the benches 50 are fixed directly to the slide 20 Alternatively, the benches can be fixed to a bar or a strip separate which is

itself fixed to the slide.

  A locking element 52, which is mounted

  pivotally on an axis 53, cooperates with the

  during the ascent of the slides (and therefore of the lifting beams), the bench seat 50 can cross

  the locking element 52 by tilting the element

  locking opposite the slide Then,

  the weight of the locking element causes the

  turn it against the slide, again at

  beneath the bench Consequently, the element of ver-

  rust prevents the slide from falling, in case of

  failure of cables or the hydraulic system.

  To release the locking system, a lever 54 is manually pushed down so as to move the locking element 52 away from the benches

  We can then lower the beam.

  In a preferred system, a safety lock

  curity is associated with each of the Au-

  in other words, there is a rack on each slide 20 There is also a locking element

  52 supported by each upright 16 and 18, which is associated

  linked to a rack provided on the respective slide

tif 20.

  The two locking elements are inter-

  connected in such a way that they can be released simultaneously using a single lever 54 An elongated rod 55 extends upwards from the locking element 52, to one end of an arm 56

  provided at the upper end of the upright 18 The former

  opposite end of arm 56 is fixed to a horizontal rod

  tale 57 which extends, inside the cross member 19, to an arm 58 located at the upper end of

  the other upright 16 A rod 59 is connected to an

  mite from arm 58 and extend down to the element

lock 52.

  Thus, a movement of the lever 54 downwards has the effect that the locking elements 52 on the

  two uprights emerge simultaneously from the two cremail-

  leers on the two slides This is an advantage

  net floor compared to various locking systems

  known on lifting equipment where it is necessary

  be able to release the locks on each side separately

of the lifting device.

  Another advantage of the latch release system used here is that when the rod 55 is urged upward, this has the effect that the rod 59 is also urged upward to release

  the locking element of the other lifting beam.

  When the rod 55 descends, this allows the locking element in the upright 18 to again come into engagement with the rack fixed to the beam 14 If, for some reason, the locking element in the

  post 16 is prevented from engaging with the rack

  beam attached to beam 16, this does not interfere with the

  latching of the locking element on the rack-

beam era 14.

  We can also use other means

  to simultaneously release the two locking elements

  lage, if desired For example, cables can

  be interconnected between the two locking elements

  lage in such a way that their clearance is obtained

  simultaneous by applying a voltage to the cables.

  The control lever 60 for actuating the

  hydraulic group is preferably placed next to the

  lock release sink 54, or at least on the same amount, so that the operator can release the

  locking system and lower the beams of the

  vage, in the same place The control lever 60 is

  linked to a vertical rod 61 which extends upwards

  up to a switch 62 The movement of the pivot lever

  while 60 upwards causes a downward displacement of the rod 61 (which is pivotally connected to the opposite end of the lever 60) As a result

  arm 64 carrying the switch 62 pivots downward.

  A switching push button 62 A then meets a bench seat or a plate 63 The closing of this electric switch excites the electric motor 27 which then drives the hydraulic pump 31 The fluid

  hydraulic is pumped from tank 29, through

  to the valve and in line 34 A, to control the retraction of the piston rod 24 A of the cylinder 24 in

  the cylinder This retraction of the piston rod drives

  ne a uniform rise of the beams 12 and 14 When the lever 60 is returned to its neutral position, the arm of

  switch is raised and the electric motor stops.

  The beams also stop rising when the mo-

  electric tor stops Hydraulic pressure in the pipe prevents the beams from coming down In addition, the locking elements engage with the

  racks fixed to the beams, which provides a block

  mechanical cage preventing the beams from descending.

  When we want to lower the beams, we first release locking elements, such as

  described above Then, push the control lever

  mande 60 down This causes a movement of

  the rod 61 upwards, so that the switching arm

  tor 74 pivots up The control rod 33, which is fixed at one end to the arm 64, turns in response to the pivoting of the arm 64 The opposite end of the rod 33 is received in the valve body 32 and this end of the rod 33 has a notched part 33 A When the rod 33 rotates in a certain direction, it controls the opening of a valve 70, which allows the hydraulic fluid from the line 34 A to return to the tank 29 The beams of lifting can then descend slowly as the fluid

returns to the tank.

  The preferred valve is illustrated in the fig-

  res 28 A and 28 B The hydraulic fluid coming from the pump

  pe 31 is discharged, via a passage 32 A, into an inlet orifice of the valve body 32 and it exits through an outlet orifice, in a pipe 34, to cause the retraction of the piston rod 24 A in

  cylinder 24 (to raise the lifting beams).

  In this situation, the valve 70 remains in contact with a seat 80 In this position, the valve 70 prevents

  the hydraulic fluid to drain back to the re-

  serve by a passage 32 C and an outlet 32 B.

  In order to open the valve and allow re-

  turn the hydraulic fluid to the tank, we rotate

  the control rod slightly in a certain direction

  tion, in such a way that the notched part 33 A attacks the lower end 70 A of the valve 70 so that the valve rocks and then lifts up relative to the

  seat 80 (as illustrated in Figure 28 B).

  When the valve 70 is initially atta-

  qué by the notched part 33 A, the valve 70 first switches slightly so as to move away from the seat 80,

  on one side The small opening thus generated in

  be the head of the valve and the seat allows the hy-

  hydraulics to start to flow down, beyond

  of the valve and in the passage 32 B back to the tank.

  This initial tilting of the valve 70 does not require

  the application of a significant force to the in-

  In other words, the length of the valve stem 70 compared to the diameter of the seat of the valve

  valve 80 provides a mechanical multiplication favo-

  maple which allows a small mechanical force to overcome

  creates the pressure of the hydraulic fluid in the system.

  This constitutes a specific advantage of the

  valve according to the present invention.

  After the valve 70 has tilted slightly to one side, relative to the seat 80, the pursuit of

  rotation of the rod 33 causes an additional tilting

  valve 70 A further engagement of part 33 A against the end 70 A pushes the valve

  upwards and away from seat 80 (as illus-

  tré on figure 28 B) so as to create a larger opening for the flow of the hydraulic fluid through the valve and towards the tank In other words,

  when the notched part attacks the lower end

  of the valve stem 70, a component of form

  this vertical and a horizontal force component are simultaneously generated This causes an initial tilting or tilting of the valve then an uplift

of the valve relative to the seat 80.

  The pressure drop across the seat of the

  pet is reduced after the initial tilting of the valve.

  The force which is then necessary to lift the cla-

  pet relative to the seat is therefore reduced.

  Thus, the operation of the relief valve described here provides a significant improvement over

  to the usual relief valves in which a component

  movable shutter health is moved directly con-

  be the hydraulic pressure prevailing in the system, this

which requires significant strength.

  The valve 70 preferably comprises a part

  conical or inclined tie 70 B directly under the head of the

  flap, to facilitate centering of the flap relative to

  worn at seat 80 when rod 33 returns to its posi-

  initial tion A spring 82 recalls the valve 70 towards

  its normally closed position A finger 84, with a res-

  associated spell 85, tends to return the rod 33 to its normal position, as shown in FIG. 28 A, when the rod is turned in the opposite direction to the direction required to attack the valve 70 Although the lower end A of the valve stem is preferably conical

  (as shown), it is not necessarily conical.

  For example, the valve stem can be a cy-

  lindrique without tapered end.

  Another feature that can be in-

  cluse is a high level elevator signaling system For example, a source 66 of radiation

  electromagnetic can be attached to the upper end

  lower of one of the uprights and a reflector 65 can be attached to the upper end of the other upright The source 66 emits a narrow beam of radiation (for example infrared radiation) which is directed towards the reflector 65 The reflected beam is received by the detector part of the source 66 If an object lifted by the lifting beams enters the path of the beam and obstructs it, then the detector no longer receives

  the beam This causes a so-

  nore to warn of the lifting situation at the level

  top When the electric motor that powers the system

  hydraulic lifting head stops, it also cuts

the audible alarm.

  Another advantage of the signaling system illustrated here is that electrical energy is only needed on the upright 18. There is no need to supply an electrical supply to the upright 16 Le

  reflector 65 does not require a power supply

  than. We can also use other types of signaling systems For example, we can fix a light source to one of the uprights and we can

  attach a photodetector to the other upright to receive

  see a light beam emitted by the light source.

  When a lifted object interrupts the light beam,

  the photodetector activates an audible alarm for warning

  provide the operator with the lifting condition at the highest point.

  Of course, the light source and the detector (or a reflector) can also be fixed to walls or another support structure close to the lifting device, to fulfill the same function or

a similar function.

  Figures 24 and 25 illustrate other mo-

  suspension yen usable in the present invention

  tion to fix and support the forks on a

  lifting frame In FIG. 24, the suspension 90 comprises

  takes a tubular element 92 to which is fixed perpendicular

  another tubular element 94

  its or gussets 93 can be welded or otherwise fixed between the two tubular elements, in a

  reinforcement purpose The tubular element 94 is shown

  tee as having a square cross section for re-

  slide a dry fork rod

  square transverse tion Thus, the suspension 90 can be moved in the longitudinal direction of a beam, and a fork tail can be moved in the transverse or lateral direction relative to

to the beam.

  Figure 25 is an end view illustrating

  a non-circular lifting beam 95 This beam comprises

  takes a substantially cylindrical tube or profile, to the outer surface of which is fixed a

  keyway with square orectectular section, as illustrated

  A suspension 95 comprises a lower part with a through opening which is substantially in conformity with the external surface of the greater part of the

  beam 97 Preferably, the opening comprises a part

  enlarged tie 96, as illustrated Suspension 95 can

  be moved in the longitudinal direction of the thumb

  tre 97 The presence of the enlarged opening part 96 makes it possible to rotate the suspension approximately 900 in one direction (for example to allow the suspension to tilt upwards and away from the vehicle to be lifted).

  Suspension 95 also includes an opening

  transverse structure for sliding reception of the fork tail 42 The tail 42 can be moved in the transverse or lateral direction with respect to

to the lifting beam 97.

Claims (16)

  1. Lifting device (10) for lifting a vehicle   three-wheeled carrier (100) of the type comprising two lateral wheels (102) and a third wheel (103), said apparatus providing an unobstructed entry passage and   lifting means which easily adapt to said vehicle   the so that said vehicle can be brought in quickly   and conveniently in the lifting device, that the device   reil can be easily adapted to vehicles of different   different mensions and that the device can be easy-   ment adapted to a vehicle not aligned with respect to the longitudinal axis of said lifting device, characterized in that it comprises: (a) two substantially horizontal lifting beams (12,14) which are transversely spaced one of the another to define an unobstructed entry for said vehicle between said lifting beams; (b) two side wheel lifting devices, each of which is easily attached to one of said beams   (12,14), to engage with a side wheel   the (102) of said vehicle at the front and at the rear of the footprint of said side wheel, said side wheel lifting device being movable in the longitudinal direction of said beam so as to adapt easily to vehicles of different dimensions and to a   vehicle misaligned with respect to the longitudinal axis   nal of said lifting device; (c) a third wheel lifting device (35) for engaging and lifting said third wheel (103); and (d) lifting means for raising said said   two beams and said three-way lifting device   fifth wheel so as to raise said vehicle to three wheels.   2. Lifting device according to the claim   tion 1, characterized in that said side wheel lifting devices can be moved transversely   with respect to said lifting beams (12,14).   3. Lifting device according to the claim   tion 1, further characterized in that it comprises a pre-   mier and a second mutually spaced upright (16,18), said first lifting beam (12) is adjacent to said first upright (16) and said second lifting beam (14) is adjacent to said second upright (18), and said means are supported by the said amounts.   4. Lifting device according to the claim   tion 1, further comprising a power supply (31) and a hydraulic cylinder (24), characterized in that   said hydraulic cylinder is movable between a posi-   extension and a retraction position and, when   that said cylinder is moved from said extension position   at said retraction position, said beams lifting (12,14) go up.   5. Lifting device according to the claim   tion 4, characterized in that it further comprises a   releasable safety locking device, for use   fishing the descent of said lifting beams.   6. Lifting device according to the claim   tion 5, characterized in that said ver-   safety rusting comprises: (a) an elongated vertical rack (50) fixed to a respective beam of said lifting beams (12,14), and (b) a locking element (52) carried by a respective amount of said amounts (16 , 18) so that, when said locking member engages said rack, said beam is prevented from descending.   7. Lifting device according to the claim   tion 1, characterized in that each said lateral wheel lifting device comprises (a) a suspension (45) and (b) a fork (40) which has an elongated tail (42), said suspension can be fixed to one of said   lifting beams (12,14), said tail is received in a   sliding and retained in said suspension, and   said fork is movable transversely with respect to port to said beam.   8. Lifting device as claimed   tion 7, characterized in that said suspension comprises a body (45) comprising (a) first and second arms (46,47) which engage with said beam   lifting (14) in such a way that the rotation an-   gular of said body relative to said beam is em-   caught in at least one direction, and (b) a receiving portion (48) for receiving and supporting said tail (42) against angular rotation relative to   to said beam in said one direction.   9. Lifting device according to the claim   tion 3, further comprising first and second vertical slides (20) fixed, respectively, to said first and second lifting beams (12,14),   characterized in that said first and second layers   scissors are slidably retained, respectively-   ment, in said first and second uprights (16,18), and said lifting means comprise (a) motor means (24) and (b) cables (21,22) functionally connected between said motor means and said first and second slides (20).   10 Method for lifting and supporting a vehicle of the type having two side wheels and a third wheel, characterized in that it comprises the steps of (a) construction of a first and a second   mutually spaced and sensitive lifting beams (12,14)   completely horizontal, so as to define an unobstructed entry for said vehicle between said lifting beams; (b) construction of two side wheel lifting devices, each of which is easily attached to one of said lifting beams, to engage with   a side wheel of said vehicle at the front and at the rear   re of the footprint of said side wheel, said side wheel lifting device being movable in the longitudinal direction of said beam   so as to easily adapt to vehicles of   different vehicles and a vehicle that is misaligned   with respect to the longitudinal axis of said lifting device ge;   (c) construction of a third-party lifting device   me wheel (35); (d) construction of lifting means for lifting said beams and said third wheel lifting device; (e) positioning of said vehicle between said lifting beams;   (f) supplying said wheel lifting devices la-   téral in engagement with said two side wheels; (g) bringing said third wheel lifting device into engagement with said third wheel; and (h) lifting said beams and said device   lifting of third wheel so as to lift said vehicle.   11. Method according to claim 10, characterized in that each lifting fork device comprises (a) a suspension (45) and (b) a fork (40) which comprises an elongated tail (42), said   suspension can be fixed to one of said beams of the   vage (12,14) and said tail is received in a sliding manner   health and restraint in said suspension.   12. Lifting fork device, charac-   terized in that it comprises: (a) a suspension (45); and   (b) a fork (40) which includes means for mounting   stage (42) for fixing said fork on said suspension   if we; so that said fork is laterally adjustable with respect to said suspension.   13 Lifting fork device following   vant claim 12, characterized in that said suspension (45) comprises a body comprising (a) first and second opposite arms (46,47) and (b) a receiving part (48), said body can come engaged with a lifting beam in such a way that angular rotation of said body relative to said beam is prevented in at least one direction, and said receiving portion can receive and support   said tail (42) against angular rotation relative to   wearing said body in said one direction.   14. Improvement in a lifting device of the type comprising an elongated lifting beam and means for lifting said beam, characterized in that it comprises:   (a) a suspension (45) which is carried by said pusher   tre and which is movable along said beam; and   (b) a fork (40) which includes means for mounting   stage (42) for mounting said fork on said suspension, so that said fork is adjustable laterally by in relation to the said suspension.   15. Method for fixing a lifting fork to an elongated lifting beam (12) having a   longitudinal axis in a horizontal plane and having a sec-   non-circular cross-section, characterized in that it comprises the steps of:   (a) construction of a suspension which can be terminated   attached to said lifting beam, said suspension comprises   both a body (45) and a receiving portion (48);   (b) construction of a lifting fork (40) comprising   both an elongated tail (42); (c) fixing said body of said suspension to the   said lifting beam in such a way that the rota-   angular tion of said suspension relative to said beam is prevented in at least one direction, said body being movable along said beam; (d) fixing said tail to said suspension in such a way that (1) the angular rotation of said tail relative to said beam is prevented in said one direction, and (2) said tail is   movable transversely to the long axis tudinal of said beam.   16 Method according to claim 15, characterized in that it comprises the reception step   sliding from said tail into said reception part.