FR2563204A1 - ATTACHMENT FOR FORK TROLLEY, AND UNLOADING METHOD USING THE SAME - Google Patents

Abstract

THE INVENTION RELATES TO AN ACCESSORY FOR THE FORK ARMS OF A FORK TRUCK INCLUDING A MAST IN ANCHORED DOOR FOR UNLOADING A LOAD ARRANGED IN A CONTAINER. IN ACCORDANCE WITH THE INVENTION, THE ATTACHMENT 50 INCLUDES A FRAME EQUIPPED WITH A PART COUPLABLE TO THE FORK ARMS 36 ALLOWING TO SEPARATELY CONNECTING AT LEAST ONE OF THE said ACCESSORY ARMS, AND WITH A PART 58 THAT CAN COOPERATE WITH A BAR OF LIFTING 60 ALLOWING THE SEPARATELY COUPLING OF THE ATTACHMENT TO THE SAID LIFT BAR, IN ORDER TO LIFT THE SAID LOAD BY A RELATIVE UPWARD MOVEMENT OF THE MAST OF THE FORK TRUCK. APPLICATION TO THE UNLOADING OF FRAGILE LIFT BAR CONTAINERS, ESPECIALLY WHEN A SINGLE OPENING ALLOWS ACCESS TO THE LOADS AVAILABLE THERE.

Description

The present invention relates to equipment for forklifts,

  and more precisely an accessory that

  you can ride on a telescopic mast forklift

  copics used to charge and discharge a fra-

  of commercial containers of the rail-road type on

  trucks, boats and railway wagons.

  The present invention is particularly suitable for unloading missile boxes with a lifting bar and disposed within a commercial container of about 6 m (twenty feet) in length, and is particularly useful when the unloading facility provided specifically for this purpose is not available, which is typically the case during a military operation. The typical dimensional characteristics of these containers are as follows: square vertical section 2.44 m (eight feet, length 6 m)

  (twenty feet), and opening at one of their ends.

  Until now, forklift trucks have

  were a telescopic mast cantilever which was

  attached a standard apron with two fork arms.

  The forklift was connected to the mast by means of hydraulic cylinders that could be slaved to the cylinders

  mast actuation. In this way, the equipment

  fork could be maintained in a relatively horizontal position, regardless of the upward movement and

lowering the mast.

  When the mast was deployed in a sensi-

  horizontally, the fork carrier had to be substantially vertical, in order to maintain

  horizontally the fixed fork arms

  specifically to this equipment. When the mast was in a substantially horizontal position, the equipment therefore had a very large height requirement. This substantially limited the capacity of the forklift to

  loading and / or unloading pallets or loads

  pressed against each other in

  roads or semi-trailers.

  Due to the limitations of use inherent in known forklifts, various methods of

  unloading, which still have disadvantages.

  To unload pallets from a mobile container carrier in the field using a standard forklift truck, it has been proposed to provide an access ramp.

  allowing the forklift to enter the container.

  to unload the load. This process presents the

  obvious to require a portable ramp, and implies that the forklift makes several trips

  and returns for unloading the container.

  It has also been proposed a so-called "sliding sheet" method, where a sheet of plastic or metal was placed on the bottom of the container, the pallets being placed on this sheet. When unloading the container, the "slip sheet" had to be drawn

  out of the container, and brought on a flatbed truck.

  Forklifts of the standard type then had to approach the side of the truck, and start unloading the pallets. In addition to the obvious risk of tearing the sheet, another problem arose

  platform was not perfectly level or perfect

  aligned with the container: the sheet could then deviate on the side of the platform, causing the fall

pallets.

  To unload containers from

  missiles, a common method was to attach

  chains to the caissons and pulling them towards the edge of the

  until at least half of the box is out of the container. A first forklift was supposed to

  then engage his fork at the front of the box for

  fish for a fall, while a second forklift

  moved on the side of the box and engaged his

  approximately to the center of gravity of the box, so as to lift it from the container and carry it

  to its final location. With this process, the balance

  precarious breakage of the box on the edge of the container

  were risks; in addition, three handling equipment were needed: one to pull the boxes out of the container, another to support

  the end of the box coming out of the container, and a third

  second to take the box in the center and take it out

of the container.

  The present invention aims to provide an accessory for a fork-lift equipment, which is specifically adapted to unloading fragile loads provided with a lifting bar, such as caissons

  missile carriers, for example, and being in

  roads or semi-trailers or containers.

  The accessory of the invention comprises a frame provided with a portion that can be coupled to the fork arms and that separably connects at least one of said arms to said arm

  accessory, and a part that can cooperate with a bar-

  hoisting means for separably coupling said accessory to said lifting bar, for lifting said load by relative movement up the

mast of the forklift.

  According to another aspect of the invention, the accessory is provided with a pair of hooks secured to the frame, and

  which can cooperate with lifting bars.

  According to another aspect of the invention, the assembly

  the accessory has a low profile, so as to facilitate

  bed his entry into a container filled with loads.

-4-

  According to another aspect of the invention, the access

  The evening is sized to allow

  with the lift bar before or after it

  been placed on the fork arms.

  The present invention therefore provides an accessory for forklift equipment which is entirely suitable for loading and unloading trailers.

  roads or semi-trailers or containers, the equi-

  fork carrier can be positioned in a substantially horizontal plane while the mast is maintained in the same plane. The invention provides an accessory of

  very low profile, and makes it possible to insert the mast and the access

  in a trailer or container filled with loads.

  We understand that it is important to maintain a low profile when we know that we use in trailers to

  containerized cargo containers of dimensionne-

  predetermined manner. Fork arms must be able to pick up and lift loads in hollows

  deep and / or when the free height is very limited.

  The horizontal movement of the fork arms facilitates the precise positioning required to take the lifting bar of a missile box, or to slip under a load pallet. The horizontal movement of the arms also makes it possible to move the load in a horizontal plane before removing it from the container, in order to release it from the bottom of the container or

from a neighboring charge.

  The invention will appear more clearly in the light of

  of the following description and drawings

  In a preferred embodiment, with reference to the figures, FIG. 1 is a perspective view of a trolley.

  cantilever forks used in connection with the

  vention; FIG. 2 is a schematic side view of the trolley

  fork of Figure 1 unloading from

  a pallet of a container placed on the ground; - Figure 3 is a schematic side view of the forklift using an accessory according to the invention for unloading boxes from a container placed on the ground; FIG. 4 is a schematic side view of the forklift conventionally unloading a

  pallet of a container placed on an overhead platform

  truck; FIG. 5 is a side view of the forklift of

  FIG. 3 unloading boxes of a

  content placed on a raised truck platform, using an accessory according to the invention; FIG. 6 is a side view of the accessory for

  fork double hook made according to the invention

  tion, and presented in use in Figure 3; - Figure 7 is a front view of the fork arm accessory of Figure 6; and Figure 8 is a schematic diagram of the leveling circuit employed to maintain the fork arms

  in a substantially horizontal position.

  A forklift truck 10 of the telescopic mast type

  that comprises a telescopic arm 12 whose rear end 14 is hinged to an off-road vehicle provided with a body 16. The body 16 is of the type described in US Pat. No. 3,937,339 (the content of which is incorporated

  here as a reference), and in particular it is

  denies a leveling device

  the vehicle body in relation to the chassis. This makes the forklift 10 particularly suitable for use on uneven terrain. The typical dimensions of such forklift trucks are as follows: approximately 7.3 m long (24 feet) in the position of load, 2.44 m wide (8 feet) and also 2.44 m high

(8 feet) (horizontal mast).

  --6- As is the usual practice for

  this type, hydraulic cylinders 18 are used for

  angularly the mast 12 with respect to the horizon-

  tale. An extension 20 is hinged to the front end 22 of the mast 12, by means of a mounting plate 24 and hydraulic cylinders 26; the axis of articulation of the jack 26 to the plate 24 being, as shown in the figure, placed substantially below the axis of articulation of the extension 20, it is possible to pivot the extension 20 so that that it is generally aligned with the longitudinal axis of the mast 12, or even that it is above

of this axis.

  The rear end of the extender 20 is provided with a pair of laterally mounted projectors 27, so that the projectors 27 will follow the movement of the extender 20. As shown in FIG. 2, a fork assembly 28 is hinged to the front end 30 of the extension 20

  by means of a connection plate 32 and hydraulic cylinders

  34. It is thus possible to rotate the assembly

  fork 28 in a vertical plane, this movement of pivots-

  being entirely independent of the pivoting movement

  the mast 12 and / or the pivoting movement of the

extension 20.

  As best shown in FIG.

  fork 28 comprises a pair of telescopic hydraulic cylinders

  copics 38 provided for horizontal movement

Fork arms 36.

  The horizontal movement of the fork arms 36 is mechanically controlled, and more precisely hydraulic, and each arm 36 can be moved independently of the other. In addition, each fork arm 36 can be moved beyond the center line 120 of the extension 20, so that the two arms 36 can be positioned

  same side of the center line 120.

  As the different figures show, the

  forked 28 is easily maintained in a horizontal plane. Previously, this position was maintained by the operator by being discriminating in handling the controls of the hydraulic cylinders, as well as by automatic systems that the operator could

  to activate if he wished. For example,

  keep the load level during high lift operations, by slaving the jacks 34 of the fork to the jacks 18 of the mast, so that the pivoting

  the mast 12 generated a corresponding movement of the

  seems to fork 28, the latter being thus maintained in

substantially horizontal position.

  But given the number of positions that can take the extension 20, it is not possible to maintain

  the fork assembly 28 in horizontal position in asser-

  screwing the jacks 34 of the fork to the cylinders 18 of the mast.

  FIG. 1 thus shows the extension 20 in a sensible position

  vertically, that is to say that the hydraulic cylinder 26 is approximately fully retracted, the fork arms 36 are substantially horizontal, and the mast 12 is

  completely returned. Figure 2 shows an entire mast 12

  deployed with the extension 20 partially deployed, by means of the jack 26, so as to allow the fork arms 36 to take and carry a pallet 40.

  height between the deployed mast 12 and the upper wall

  container 42 is indicated by the distance D. The cylinder 18 can not be pulled out to a sufficient degree.

  to raise the mast 12 in order to lift the pallet 40.

  The lifting of the pallet 40 is therefore necessarily effected by taking out the hydraulic cylinder 26, so as to pivot the extension 20, thus lifting the pallet 40. As explained below, fork arms 36 are required. that they remain horizontal, with a slight latitude of movement.

  Figure 3 shows the mobile unit 10

  A load 44, which requires that the extension 20 is substantially in a plane parallel to the horizontal plane defined by the load 44. In this case again, the distance D provides only a small free height. The mast 12 is presented in approximately full retracted position, with the hydraulic cylinder 18 also in the fully retracted position, so as to obtain the small height requirement necessary between the upper wall of the container 42 and the mounting plate 24. As in FIG. Figure 2, it is necessary that the fork arms 36 are substantially horizontal of the plane defined by the load 44. In order to maintain the small overall height, it must be satisfied with a limited degree of adjustment of the cylinder 18 when the lifting and unloading of the load 44 of the container 42. As a result, the hydraulic cylinders 26 are

  almost completely out, so as to position the

  lanyard 20 in the same plane as the forks 36.

  Since the arms 36 can be adjusted independently by pivoting, the hydraulic cylinder 34 can hold the arms 36 in the horizontal plane during the adjustment of the

position of the extension 20.

  FIG. 4 shows the mobile unit 10 unloading a pallet 40 from a raised container 42, as is the case when the container is placed on a platform of

  45. In this case, the mast 12 is nearly complete

  deployed, and the hydraulic cylinders 26 and 34 are partially extended to place the fork arms 36 -9- under the pallet 40. To lift the pallet 40, it raises the mast 12 first, then after having returned slightly, you can continue lifting the

  pallet 40 by deploying the cylinders 26.

  FIG. 5 shows the mobile unit 10 discharging a load 44 from a raised container 42, which requires

  that the extension 20 is substantially in a parallel plane

  is aligned to the horizontal plane defined by the load 44. The mat 12 is slightly raised by the cylinders 18, and is partially deployed. The hydraulic cylinders 26 and 34 are fully extended, so as to place the extension 20 in the same

plan that fork arms 36.

  The fork assembly 28 is equipped with a circuit

  level 29 shown schematically in Figure 8.

  The leveling circuit 29 includes a pendulum switch 31, located on the fork assembly 28, just behind the cylinders 38. Although it can also be used

  other means for the automatic upgrade, a

  pendulum mutator of the type sold by P-Q Controls, Inc. under the model number 410 appeared perfectly

  adapted for the particular needs of this application.

  The pendulum switch 31 is mounted at an angle such that an upward tilt of the fork arms 36 will be detected by the switch 31 as corresponding to a horizontal position. The pendulum of the switch 31

  oscillates in a plane substantially parallel to the long axes

  of the forks 36, and is adjusted to provide a signal corresponding to the detection of an angle

  predetermined in an angular range from 1.5 to 3.

  The output of the switch 31 is connected to a selector 33 which makes it possible to switch off the switch 31 in order to

  to use manual control 37. The

  dule is connected, via the switch 33, to a proportional control solenoid valve 39, placed

  on the extension 20, behind the plate 35. The electro-

  Valve 39 controls the supply of hydraulic fluid to the cylinders 34. Upon detecting a non-horizontal position of the fork assembly 28, the pendulum switch 31 transmits a signal to the control solenoid valve 39, and the pump 41 supplies in hydraulic fluid the cylinders 34 so

  maintain the fork assembly 28 in a substantially

horizontally.

  Figure 2 illustrates the use of the team

  fork carrier for unloading a pallet 40 in position

  in a container 42, and Figures 2 and 3 have a container placed on the ground, or at least the same level as the forklift 10. It should nevertheless be noted that the forklift 10 is particularly

  well suited for unloading containers in over-

  high, such as those carried by road trailers, as shown in Figures 3 and 4. In the latter case, the mast 12 is substantially deployed at its maximum length, and the extension 20 is positioned at an appropriate angle to allow a subsequent deployment of the fork, and also to position the fork assembly 28 under the pallet. The horizontal movement of the fork arms 36 is particularly useful for this operation, since the various load pallets 40 may have different receiving areas for the fork legs, and the fork carriage 10 may not always be in position.

  perfect alignment with the pallet 40. Like these two

  During the same load handling operation, the fork arms 36 are provided with a wide range of horizontal displacement, from their maximum position of separation illustrated in FIG. 1, to a position in The arms are of the same side with respect to the center line 120. Similarly, it is not uncommon when the pallet 40 is transported that the pallet moves and is in contact with the wall of the container.

  42 or a neighboring pallet. A slight horizontal shift

  fork of the forks 36 will release the pallet 40, and the pallet may be out, preferably by retracting the telescopic mast 12, or by rolling back the carriage

  with fork 10 to move it away from the container 42.

  FIG. 3 illustrates the use of the forklift truck 10 for unloading a container filled with loads, in particular for taking out of a container 42 a box 44, of the missile box type, for example. For this operation, the forklift 10 uses a fork arm accessory according to the invention, here provided with a double hook. The accessory 50 consists of a rectangular frame 52, whose interior is divided by a central partition 56 so as to define two housings 54 for receiving fork arms. Two hooks

  58 intended to cooperate with a lifting bar are

  frame 52, and extend downward, a hook

  58 being centered below each dwelling 54.

  The total weight of the accessory 50 is about 0.23 m (9 inches) so as not to increase the height requirement which must remain low: it is indeed in an operation like this that the weak congestion of the extension

  20 and the fork assembly 28 are extremely advantageous

  geous. Each box 44 is provided with a recessed lifting bar 60 placed approximately at the center of gravity of the box 42, said lifting bar being housed in a recess 62 provided for this purpose. When the transverse lifting bar 60 does not affect the entire width of the box 44, the possibility of a horizontal movement of the arms

  fork 36, with the horizontal movement of the access

  The result of the 50th evening is again very important.

  As seen in Figure 3, the fork arms 36

  are positioned horizontally and inserted in the boxes.

  54. Accessory 50 may, where space permits,

  be manually coupled to the lifting bar 60,

  then seizing the fork arms 36 in the housing 54; it is also possible to thread the accessory 50 onto the forks 36, then to position it so as to couple it to the lifting bar 60. In the latter case, the extension piece is brought into a substantially horizontal position, and

  the fork assembly 28 is maintained in a substantially

  horizontally. The hooks 58 are positioned

  above the recess 62, behind the lifting bar 60. The hooks 58 are then lowered towards the recess 62, and then moved forwards until the rear portion 64 of the hooks 58 is closed. engages under the lifting bar 60. We can then slightly lift the box 44, and if necessary move it in a horizontal plane, as

  it has been exposed above, in order to free it from the wall of.

  container or neighboring boxes. The box 44 can then be removed from the container, preferably by retracting the mast 12 if the latter was in the deployed position, or by moving the fork carriage 10 back away from it.

container 42.

  Figures 2 to 5 illustrate by way of example two types of application of the present invention, with a container on the ground or elevated; there are in fact an infinite number of combinations of the positions of the extension 20 and the fork assembly 28, so that the potential uses of such a forklift extension

are very numerous.

  The following claims, which

  The main features of the invention are also encompassed by the various embodiments of the invention. -13-

Claims (4)

  1. Accessory for the forks of a fork   forked riot having a cantilevered mast used for unloading a load disposed in a container, characterized in that it comprises a frame (52) provided with a portion which can be coupled to the fork legs for releasably connecting at least one of said arms   accessory, and a part (58) that can cooperate with a bar-   lifting lever (60) for separably coupling said attachment to said lifting bar to lift said load by relative upward movement of the mast of the forklift.   2. Accessory according to claim 1,   in that the frame comprises at least one housing (54) into which said fork arms can be inserted, and at least one hook (58) integral with said frame for coupling   said frame to said lifting bar (60).   3. Accessory according to claim 2, characterized   rised by the fact that the frame defines two members (54), each   each of said housings receiving one of said fork arms, a hook that can be coupled to a lifting bar being associated to each of said dwellings.   4. A method of unloading a container whose interior is accessible only by a single opening,   the charges arranged inside the container being sen-   siblement rectangular and provided with a transverse horizontal lifting bar and housed in a recess provided for this purpose, characterized in that it comprises the following steps:   - insertion by the opening of the container means (58) allow-   both a coupling to the lifting bar (60) connected to a telescopic mast, positioning of said coupling means above the recess (62) of the load, - lowering of the coupling means in the direction of the recess, coupling of the lifting bar and said coupling means, lifting of the load, and unloading of the load by the recoil of said coupling means, out of the interior of the container and by the unique opening of it.