EP3031769B1

EP3031769B1 - Vehicle comprising scissor stabilisers

Info

Publication number: EP3031769B1
Application number: EP15186638.1A
Authority: EP
Inventors: Marco IOTTI
Original assignee: Manitou Italia SRL
Current assignee: Manitou Italia SRL
Priority date: 2014-12-09
Filing date: 2015-09-24
Publication date: 2017-08-23
Anticipated expiration: 2035-09-24
Also published as: EP3031769A1

Description

The invention relates to stabilizers for lifts or handlers or air platforms of the telescopic type and, particularly, of the rotary type.
Telescopic lifts are known which consist of a vehicle provided with a frame which is movable on tracks or wheels, comprising a frame-mounted platform, whereon the driver's cab is in turn mounted together with a telescopically extendable maneuvering arm.
At the distal end of the arm, there is provided an equipment, or "accessory" for lifting or moving loads, such as for example a fork, a basket, a bucket, a side-shifter, a winch, and the like.
For the sake of brevity, the apparatus at issue shall be generically referred to as "the vehicle", regardless of the type of equipment installed thereon. In order for the loads to be lifted and moved at great heights and with a significant "working radius", the lift need to be stabilized.
There are known several types of stabilizers mounted on the vehicle frame which are chosen according to the performance required by the apparatus and to customer needs.
Stabilizers may pass from an extended working configuration, wherein the they support the whole vehicle while lifting it from the ground, to a retracted rest configuration, wherein they exhibit an overall width which is in compliance with the rules governing road travel.
In the working configuration thereof, stabilizers stand on the ground by means of so-called "supporting feet", thereby defining a supporting quadrangle.
The greater the amplitude of this quadrangle, the greater the stability offered to the vehicle.
In addition, the greater is the height to which the vehicle is raised by the stabilizers, the more said vehicle is versatile, which implies being effectively usable on uneven or non-flat grounds.
It is to be noted that for the lifting of heavy loads, once stabilized, the frame of the vehicle shall be maintained as horizontal as possible.
One stabilizer of the known type, is the so-called "scissors stabilizer" as shown in Figures 1 and 4.
The scissor stabilizers 10 of the known type are formed by two stabilization assemblies provided on the front and on the rear of the vehicle and mounted on the frame thereof, in proximity of the wheels 2. Each stabilization assembly comprises a pair of telescopically extensible arms 30, 301, usually with a single extension, which arms exhibit corresponding distal ends intended to be resting on the ground via aforementioned "supporting feet" 40, 41, as well as proximal ends which are hinged to a support frame 50.
The support frame 50 is the component of the stabilization assembly that is fixed directly to the vehicle 10.
The two arms 30, 31 of each assembly are arranged side by side, opposite one another, and are further individually solidly constrained to the corresponding support frame by means of hydraulic cylinders 60, which are in turn hinged to said frame 50.
When the stabilizers are in the retracted configuration shown in Figure 1, the arms 30, 301 are arranged horizontally.
In detail, when a stabilization assembly of the known type is in the retracted configuration, the two arms 30, 301 thereof lie in the same horizontal plane.
When arranged in this configuration, the arms 30, 301, as well as the supporting feet 40, 401, must not exceed the overall width of the vehicle 10 allowed by the rules of road travel.
Furthermore, for the purposes of off-road driving of the vehicle 10 or in order for it to climb ramps or cross bumps, the arms 30, 301 of the stabilizers, in the retracted configuration, shall leave an adequate ground clearance.
In other words, the pairs of arms 30, 301, as well as the supporting feet 40, 401, must be located at a height from the ground allowing the types of use as specified in the preceding paragraph.
In more detail, the ground clearance determines what in jargon is called "angle of attack" of the vehicle 10.
The angle of attack is substantially the angle that the vehicle 10 may assume on uphill or downhill slope without any part thereof, nor even the stabilizers, impacting the ground.
When the stabilizers are in the working configuration, the arms 30, 301 are extended and resting on the ground through the supporting feet 40, 41.
In this configuration, the arms 30, 301 are oblique relative to the ground and spread apart like scissors.
The maximum length of the arms 30, 301 and the distance between the centers of rotation C1, C2 of the arms relative to the support frame 50, are among the factors of outmost importance in determining performance of the stabilizers.
The length of the arms 30, 301, however, is limited by the maximum transversal dimension exhibited by the vehicle 10 in the retracted configuration thereof.
The distance I between the centers of rotation C1, C2 influences the horizontality of the vehicle 10 during the stabilization step.
Thus, the value of the length of the arms 30, 301 and the distance between the centers of rotation C1, C2 of current stabilizers, is determined in such a manner as to confer the best performance to the vehicle 10 according to the conditions established.
US3958813 discloses a crane provided with scissor outriggers including extensible beans that, in the retracted position, are arranged horizontal. WO2014162191 discloses a lift truck comprising stabilization means having extensible arms that, in the closed position, are arranged horizontal.
In consideration of the fact that the vehicles are destined to off-road use, to climb ramps and to cross bumps or the like, the need is felt at the time within the market of lifts and similar vehicles, to further increase performance in terms of stabilization while in compliance with the rules of road travel.
In this context, the technical task at the base of the present invention is to provide a vehicle comprising scissor stabilizers, which is able to meet the above need.
The technical task as mentioned, is achieved by a vehicle which comprises scissor stabilizers realized according to claim 1.
Further characteristics and advantages of the present invention will become more apparent from the indicative, and therefore non-limiting description, of a preferred but non-exclusive embodiment of a vehicle provided with scissor stabilizers, as illustrated in the accompanying drawings in which:

Figure 1 is a front view of a vehicle provided with scissor stabilizers, according to the prior art;
Figure 2 is a front view of a vehicle provided with scissor stabilizers according to the invention, in the extended working configuration thereof;
Figure 3 is a front view of a vehicle provided with scissor stabilizers according to the invention, in the retracted rest configuration thereof;
Figure 4 is a front view in which the vehicle of the prior art and the one described in the present invention, are arranged side by side;
Figure 5 is an axonometric view of the front stabilization assembly of the vehicle of the invention, wherein the latter is illustrated coupled to the front wheels; and
Figure 6 is a front view of a connecting element comprised within the stabilization assembly.

With reference to the appended figures, by the numeral 1 it is generally indicated the vehicle comprising scissor stabilizers, realized according to the invention.
The vehicle 1 herein described, may be a lift or telescopic handler, particularly rotatable, or a forklift truck or an aerial platform of the telescopic type or similar machines intended for the lifting of loads.
The scissor stabilizers of the invention comprise at least one stabilization assembly 11, provided with relative support frame 5, whereon at least a pair of telescopically extensible arms 3, 31 is assembled.
The stabilizers preferably provide two stabilization assemblies 11 which are arranged on the front and on the rear of the vehicle 1 and mounted on the frame thereof.
In detail, the component of the stabilization assembly 11 which is termed "support frame" 5 is mounted on, or integrated in the vehicle frame 1. Each telescopic arm 3, 31 is provided with a first segment 32, 33 hinged to the corresponding support frame 5 and with a second extractable segment 34,35.
Supporting feet 4, 41, in jargon termed "stabilizing feet", are provided relative to the distal ends of the arms 3, 31, i.e. to the second segments 34,35.
The two arms 3, 31 of the stabilization assembly 11 are mounted opposite one another.
Each stabilization assembly 11 is suitable to pass from an extended working configuration (see Figures 2, 5 and 6), wherein the vehicle 1 is stabilized, to a retracted rest configuration (see figure 3), in the which the vehicle 1 exhibits the minimal transversal dimension T and in which the stabilization assembly 11 reaches the maximum height from the ground, thereby defining a clearance between the vehicle 1 and the ground, or "ground clearance" L.
The stabilization assembly 11 may of course pass alternately from one configuration to another.
By the term transversal dimension T, it is to be meant the size of the width of the vehicle 1, being defined by the development of the stabilization assemblies 11 between the sides of the vehicle 1 itself.
More in detail, the transversal dimension T is defined by the distance between the supporting feet 4, 41.
The ground clearance L is defined between the bottom of the stabilization assembly 11, in its retracted configuration, and the ground, and is comprised between the wheels 2, or tracks or the like.
If the vehicle 1 is placed on a flat ground, the transversal dimension T extends horizontally and the ground clearance L vertically.
As previously mentioned, the ground clearance L defines the attack angle of the vehicle 1, thus influencing performance level thereof.
Preferably each support frame 5 comprises first of all a main element 51, which is stationary relative to the rest of the vehicle 1.
To be precise, the main element 51 is mounted on the vehicle 1 at a suitable height from the ground, i.e. at a given distance from the point where the tires touch the ground.
The height at which the support frame 5 is mounted with respect to the vehicle 1, determines the height at which the latter is being brought as soon as the stabilizers are in the extended working configuration thereof. Indeed, the lower is the support frame 5, the greater will be the height K2 reached by the wheels 2 with respect to the ground, and the lower is the ground clearance L.
This aspect will be discussed further below.
In this case, the support frame 5 may include a movable connecting element 7 for each arm 3, 31, being hinged to both the main element 51 and to the first segment 32, 33, thus allowing movement of the arm 3, 31 during the transition between the retracted configuration and the extended configuration.
Preferably, the main element 51 is formed by a plurality of plates opposite one another and connected between cross members.
The points at which the connecting elements 7 are hinged to the main element 51 will be termed hereinafter "centers of rotation" C1, C2, while the points at which the connecting elements 7 are hinged to the first segments 32, 33 shall be simply called "hinge points" P1, P2.
The arms 3, 31 are further individually solidly constrained to the main element 51 by means of hydraulic cylinders 60, or other actuators, in turn hinged to the main element 51 of the frame 5.
Of course the hydraulic cylinders 60 are arranged for moving the stabilizers from the retracted configuration to the extended configuration and vice versa.
According to an important aspect of the invention, when in the retracted configuration, the arms 3, 31 are arranged diagonally one to another, and the clearance L between the vehicle 1 and the ground is defined by the proximal ends 36, 37 of the first segments 32, 33.
As it will become more clear hereinafter, this arrangement, allows to obtain a lower hinge point P1, P2 of the first segment 32, 33 of the arms 3, 31 than the prior art, see Figure 4.
In the extended configuration, for a given maximum length of the arms 3, 31, at equal distance I between the centers of rotation C1, C2, the lowering of the hinge point P1, P2 allows to significantly increase the height K2 at which the wheels 2 are brought, i.e. the distance of the tires to the ground (see figure 4).
Indeed, owing to the invention, a better use can be made of the space occupied by the stabilizers in the retracted configuration thereof.
In detail, in comparison to the height K1 that can be reached by the known vehicle 10, such increased height K2, at which the vehicle of the present invention is brought, is defined based on the height at which the support frame 5, 50 is mounted on the corresponding vehicle 1, 10.
It follows that, owing to the invention, for a given width of the ground clearance L, i.e. with an equal angle of attack, the proposed vehicle 1 is able to be better stabilized on uneven grounds, since a greater lifting height allows greater efficiency in terms of horizontal arrangement of the frame of the vehicle 1.
Note that, in the example shown in Figure 4, both the stabilizers of the invention and those of the prior art, exhibit the same incidence angle A between the arms and the ground.
To better understand how the invention attains the aims thereof, it is appropriate to describe further features of the preferred embodiment of the stabilizers provided by the present invention.
As mentioned, the distal ends of the second segments are provided with supporting feet 4, 41, exhibiting a corresponding supporting surface 42, 43, which is destined to be in contact with the ground.
The supporting feet 4, 41 preferably comprise substantially triangular bodies, which are freely pivoted in the corresponding second segment 34, 35, wherein the supporting surface 42, 43 is defined by the base of the "triangle".
According to a preferred aspect, in the retracted configuration, the supporting surfaces 42, 43 of the supporting feet 4, 41 lie in corresponding substantially vertical planes.
In detail, each supporting foot 40, 41 may include two lateral ends, defined by the angles formed at the base of the triangle, one of which lateral end 44, 45 is heavier than the rest of the supporting feet 40, 41.
This arrangement allows that, in the retracted configuration, such heavier end 44, 45 is facing downwards.
As previously mentioned, in the retracted configuration of the prior art, only the lower ends of the supporting feet define the ground clearance of the stabilizers.
In fact, in the retracted configuration of the prior art, the first and second segments of an arm are perfectly parallel one to another and located at a greater height than the ideal plane, whereon the lower ends of the supporting feet or, more precisely the sharp ends thereof, are placed. Owing to the lowering of the hinge points P1, P2, the invention allows to better use the spaces obtained, and preferably, aforesaid proximal ends 36, 37 of the first segments, or rather the lower sharp ends thereof, are placed in the same ideal plane of the lower ends 44, 45 of the supporting feet 4, 401, said plane P being practically the minimum lower projection plane (see figure 3).
In the example shown, the support frame 5 comprises a pair of connecting elements 7 for each arm 3, 31, which connecting elements 7 are parallel one to another.
As shown in Figure 6, each connecting element 7 preferably comprises a plate defined by a first part 71 exhibiting a substantially trapezoidal shape, and a second part 72 with a substantially triangular shape, said parts 71, 72 being joined one to another at one common side, or base 70.
In detail, the "triangular" and "trapezoidal" shape of the plate 7 have rounded angles defining corresponding lobes thereon.
Here, the height H1 of the second part 72 is greater than the height H2 of the first part 71.
In fact, the plate of the connecting element 7 comprises a first hole 73 passing through the connection with the first segment 32, 33 of an arm 3, 31, thus defining above mentioned hinge point P1, P2, which is located in the first part 71 of the plate 7 itself.
Further, the plate includes a second through-hole 74 passing through the connection with the main element 51 of the support frame 5, thereby defining the mentioned center of rotation C1, C2, which is placed near the vertex of the first part 72 of the plate.
Therefore, the greater height H2 of the triangle 72 with respect to the trapezium 73, helps to lower the hinge points P1, P2.
Another possible explanation of the geometrical characteristics of the plates of the connecting elements 7, is to state that each plate comprises four main lobes, one of which is an upper lobe which ends with the rounded vertex of the "triangle" 72 and is placed at a distance from the first hole 73 greater than that of the other lobes, said second hole 74 being formed at said upper lobe.
From the above, it appears clear that, if compared to the scissor stabilizers of the prior art, the stabilizers of the present invention offer better performance, while maintaining constant and extremely reduced the transversal dimension T and the ground clearance L.
In fact, owing to the greater lifting height or "stabilization height " allowed by the stabilizers of the invention, a more effective horizontal arrangement (or "levelling") of the vehicle frame 1 on uneven grounds may be attained. Alternatively, it may be taken advantage of the inventive concept herein described by increasing the ground clearance L, and thus the angle of attack, based on a corresponding maximum excursion reachable by the vehicle 1 during the stabilization step.
Indeed, where the support frames 5 of the stabilization assemblies 11 are mounted at a height greater than that of the frames 50 of the known vehicles 10, the lowering of the hinge points P1, P2 may serve for compensating the greater distance at which the frame 5, or rather its main element 51, is located relative to the ground.
Thus when the stabilizers proposed are in the extended configuration thereof, the vehicle 1 can be brought to same height of the prior art, however when the stabilizers are in the retracted configuration, the angle of attack is instead increased with respect to the known vehicle 10.
So, here, the vehicle 1 of the present invention is able to overcome bumps or ramps with stronger inclination.
Interim solutions are also possible wherein the invention is applied to increase both the angle of attack and the maximum excursion during the stabilization step, and a compromise is established in relation to the increase of these two factors.
Such advantageous results are due to the technical solutions through which lowering of the hinge points of the telescopic arms 3, 31 is allowed.

Claims

A vehicle (1) comprising scissor stabilizers, said stabilizers including at least a stabilization assembly (11) provided with at least a support frame (5) on which at least a pair of telescopically extendible arms (3, 31) is assembled, each arm (3, 31) being provided with a first segment (32, 33) hinged to said frame (5) and at least a second extractable segment (34, 35);
wherein said stabilization assembly (11) is adapted so as to pass from an extended working configuration, in which the vehicle (1) is stabilized, to a retracted rest configuration, in which the vehicle (1) has the minimum transversal dimension (T) and in which the stabilization assembly (11) has the maximum height above the ground so as to define an opening (L) between the vehicle (1) and the ground;
characterized in that, in said retracted configuration the arms (3, 31) are arranged oblique to one another and said opening (L) between the vehicle (1) and the ground is defined by proximal ends (36, 37) of said first segments (32, 33).
The vehicle (1) according to the preceding claim, wherein said minimum transversal dimension (T) is defined by the mutual distance between distal ends (42, 43) of the second segments (34, 35).
The vehicle (1) according to the preceding claim, wherein said distal ends of the second segments (34, 35) are provided with supporting feet (4, 41) having a corresponding supporting surface (42, 43), said minimum transversal dimension (T) being defined by the distance between said supporting surfaces (42, 43).
The vehicle (1) according to the preceding claim, wherein in said retracted configuration of the stabilization assembly (11), the supporting surfaces (42, 43) lie in corresponding vertical planes.
The vehicle (1) according to the preceding claim, wherein said supporting feet (4, 41) are freely pivoted in the corresponding second segment (34, 35) and each comprises a first heavier lateral end (44, 45) so as to enable, in the retracted configuration, said first lateral ends (44, 45) of the supporting feet (4, 41) and said proximal ends (36, 37) of the first segments (32, 33) to lie in a same plane (P).
The vehicle (1) according to at least one of the preceding claims, wherein said support frame (5) comprises a main element (51) that is fixed relative to the rest of the vehicle (1) and at least a movable connecting element (7) for each arm (3, 31), wherein the movable connecting element (7) is hinged to both said main element (51) and said first segment (32, 33) so as to enable the movement of the arm (3, 31) while passing from the retracted configuration to the extended configuration.
The vehicle (1) according to the preceding claim, wherein each connecting element comprises a plate (7) defined by a first part (71) with a substantially trapezoidal shape and a second part (72) with a substantially triangular shape joined at a common side (70), the height (H1) of the second part being greater than the height (H2) of the first part.