Tracked vehicle for ground finishing with lifting working components

Abstract

A tracked vehicle for grooming the ground, in particular a snow groomer for grooming ski slopes, the vehicle comprising: a main support frame, which is constructed to support lateral tracks and an upper cab; at least one working assembly, preferably a snowplow assembly, which is coupled to the main support frame at the front and at the rear and is constructed for grooming the ground during movement of the vehicle; a lifting device for the working assembly, which is constructed to selectively switch it between a lowered first working position in which the working assembly is in contact with the ground and a raised second inactive position in which the working assembly is not in contact with the ground; at least one hydraulic stabilizing device, which acts on the working assembly and is constructed so that the movement of the working assembly relative to the main support frame is not inhibited in the lowered first working position, and stabilizes the working assembly relative to the main support frame with greater movement resistance in the raised second inactive position.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102019000024811 filed on December 19, 2019, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The technical field to which the present invention relates is that of tracked vehicles for grooming or working the ground. A preferred embodiment of the invention relates to a snow groomer, i.e. a tracked vehicle configured for grooming a snow-covered ski slope. The term "grooming" relates to performing a specific operation on the ground (on the snow in the case of a snow groomer) during the movement of the vehicle in order to give the ground a desired configuration. To this end, these vehicles comprise a main frame coupled to a working assembly (a snowplow assembly in the case of a snow groomer) comprising at least one device configured for working the ground. In the case of a snow groomer, the snowplow assembly generally comprises: a snowplow configured to operate in front by plowing the snow; and a groomer configured to give the (optionally plowed) snow a specific configuration. As is known, in these tracked vehicles, the working assembly is configured to assume two positions relative to the main frame, i.e. a first, lowered working position in which it acts on the ground, and a second, raised, inactive position in which it is not in contact with the ground and the vehicle can move more freely. In the first, lowered position, the working assembly must be supported so that it can follow the shape of the ground to be trimmed with the least possible resistance. In other words, in the first, lowered position, the working assembly must be supported by the main frame in a non-rigid manner. In the second, raised position, the working assembly must be supported by the main frame in a rigid manner to prevent undesired movements of the working assembly during movement of the vehicle. It is known to provide suitable stabilizing devices acting on the working assembly to ensure these relative support configurations. In this technical field, the present invention addresses the problem of providing a stabilizing device that is particularly effective and can replace the known stabilizing devices. Background Art

[0004] As mentioned above, the present invention relates to the technical field of tracked vehicles for working and grooming the ground. Only preferably, the present invention relates to the technical field of snowplows, that is, those tracked vehicles used for preparing and grooming snow-covered ski slopes. Therefore, although the present invention can be extended to other situations and not just snowplows, for the sake of simplicity, the following description will only refer to snowplows. However, this example does not limit the scope of protection of the present invention. Generally speaking, a vehicle for working and grooming the ground includes a main frame or support platform, which is used for tracked parts mounted on opposite sides of the frame and a cab mounted centrally on the support frame. Starting from this general structure, the vehicle for working and grooming the ground usually includes one or more specific operating units or working assemblies connected to the front or rear of the frame. The field of snowplows generally considers a rear snow plow assembly configured for grooming snow, and a front push blade configured for moving a large amount of snow along a ski slope. The third working assembly may be a winch assembly configured to ensure the stability of the snow groomer on relatively steep slopes and to prevent the snow groomer from slipping when it loses its grip on the snow. The construction details of these working assemblies present in the snow groomer will not be provided here, because on the one hand they are well known to those skilled in the art and on the other hand they themselves are not critical for the purpose of applicability of the present invention.

[0005] It is known that a front or rear working assembly (snowplow assembly of a snowplow) can present two different configurations relative to the main frame supporting it. In particular, a snowplow assembly for a snowplow can be selectively switched between two configurations or two positions. In a first position, which can be defined as a working position, the front or rear working assembly is in a position that allows it to act on the ground (in the case of a snowplow, on the snow) during the movement of the vehicle. In a second position, which can be defined as an inactive position, the front or rear working assembly is in a position that does not allow it to act on the ground (in the case of a snowplow, on the snow) during the movement of the vehicle. Since the transition from the first position to the second position is carried out by lifting the working assembly, the first position can also be defined as a lowered position, while the second position can be defined as a raised position. In order to selectively switch from one position to another, the vehicle includes a lifting arm, which is connected to the main frame on one side and to the lifting frame connected to the working assembly on the other side. As is known, the lifting arm is hydraulically operated and includes a cylinder that accommodates a moving piston. By moving the piston hydraulically, i.e. by flowing a fluid (oil) in the cylinder chamber, the piston slides relative to the cylinder, thereby raising or lowering the lifting frame and thus raising or lowering the associated working assembly. As mentioned above, in the raised configuration and the lowered configuration, it is preferred that the working assembly is supported with different degrees of rigidity. In the lowered position, the working assembly is in contact with the ground and requires the ability to adapt to the changing ground configuration during the movement of the vehicle. Therefore, for this purpose, the bracket is required to be of a type with low rigidity, i.e., able to move in space. In the raised position, the working assembly is not in contact with the ground, and the bracket is required to have high rigidity in this position to prevent undesirable movement that may slow down the movement of the vehicle. It is now known to provide a specific device called a stabilizer, which can tighten the coupling between the working assembly and the main frame in the raised position. The known stabilizer is formed in the form of a pair of cylinders, in which a spring group is arranged. The spring group is configured so that a reaction force is generated on the raised working assembly due to the lifting of the working assembly (i.e., due to the movement of the piston in the corresponding cylinder). This force generated generates a constraint (in addition to the other forces present) that has the purpose of preventing the working assembly from moving.

[0006] However, the stabilizers of the prior art described above have some disadvantages. In fact, the mechanical nature of the stabilizers presents several key problems. The first is that these components are often damaged and therefore do not ensure adequate reliability over time. The second concerns the stresses transmitted by these devices to the working assembly. In fact, such stresses cause local damage in the coupling area between the stabilizer and the working assembly. Finally, the mechanical stabilizers described above do not always operate in a manner that cooperates with the lifting device, which sometimes results in a non-optimal situation in which the working assembly is raised but not yet stable. Summary of the invention

[0007] Based on the above-mentioned prior art, an object of the present invention is to provide a tracked vehicle for grooming the ground, in particular a snow groomer for grooming ski slopes, which can overcome the above-mentioned disadvantages of the prior art.

[0008] A vehicle into which the present invention may be integrated is a vehicle comprising the following components:

[0009] - a main support frame configured to support the crawler parts on the sides and the cab on the top;

[0010] at least one working assembly, preferably a snowplow assembly in the case of a snowplow, coupled to the main frame at the front and rear and configured to groom the ground (groom the snow in the case of a snowplow) during movement of the vehicle;

[0011] A lifting device for the working assembly, configured for selectively switching the working assembly between a first, lowered working position in which the working assembly is in contact with the ground and a second, raised, inactive position in which the working assembly is not in contact with the ground.

[0012] The above description does not require additional details as they are well known to those skilled in the art.For example, in the field of snow groomers, it is known to provide a rear snow plow assembly that can be selectively lifted from the ground.

[0013] With respect to the above, references to "side" and "front / rear" relate to the forward direction of movement of the tracked vehicle.

[0014] For the purposes of the present invention, the term "ground" does not only denote the surface layer of the earth's surface in a geological sense, but in general it also denotes the surface with which the vehicle cooperates during its movement. Thus, the ground according to the present invention is primarily snow and / or ice cover, since the preferred application of the invention relates to snow groomers. However, in other applications, the ground may be a grassy or muddy surface of a forest or cultivated area.

[0015] According to a first aspect of the invention, the vehicle further comprises at least one hydraulic stabilizing device acting on the working assembly. The hydraulic stabilizing device is configured so that it does not inhibit the movement of the working assembly relative to the main support frame in a lowered first working position. In fact, in this position, the working assembly must move as freely as possible to better adapt to the changing configuration of the ground to be trimmed. For example, the working assembly can perform a roll rotation (i.e. around the axis of forward movement) and a pitch rotation (around the lateral axis). Conversely, the hydraulic stabilizing device of the invention is also configured so that it stabilizes the working assembly in a raised second inactive position, i.e., prevents the movement of the working assembly relative to the main support frame or creates a greater resistance to this movement. The term "stabilize" has the meaning of inhibiting or counteracting the typical movements allowed to the working assembly when it acts on the ground.

[0016] The innovative provision of a hydraulic type stabilizer makes it possible to overcome the disadvantages of the prior art which essentially only provides a mechanical stabilizer. In fact, the hydraulic drive ensures a longer service life of the device in safe conditions, reduces the stress transmitted to the working components, and improves the reaction time.

[0017] According to a preferred embodiment of the invention which will be described with reference to the accompanying drawings, the hydraulic stabilizing device is a double-acting hydraulic actuator; preferably, the double-acting hydraulic actuator comprises a cylinder housing a moving piston operated by a drive fluid selectively supplied to a main chamber of the cylinder.

[0018] According to this embodiment, the hydraulic stabilizer comprises two ends (one of which is an extension of the piston) coupled to the working assembly and the lifting frame, respectively. The lifting device connected to the main frame acts on the side opposite to the lifting frame. When the working assembly is lifted, that is, when the lifting device that lifts the lifting frame (and lifts the working assembly by dragging) is operated, the driving fluid is supplied to the main chamber of the stabilizer. Initially, the piston moves until it reaches the end of its stroke, so as to pressurize the main chamber. In this way, the structure becomes very rigid, also resulting in the tightening of the working assembly, thereby inhibiting its previously allowed movement.

[0019] According to a preferred embodiment of the present invention, the above-mentioned stabilization device may include a second chamber configured to allow fine adjustments when the main chamber is filled and under pressure.

[0020] Preferably, the lifting device is also a hydraulic actuator comprising a cylinder housing a moving piston driven by a fluid. In this case, the operation of the lifting device and the operation of the stabilizing device can be coordinated by providing a hydraulic circuit connecting the lifting device to the stabilizing device.

[0021] Of course, different methods may also be provided to operate the two hydraulic devices in a coordinated manner.

[0022] If the vehicle is a snow groomer, it is known that the working assembly may include a snow plow and a grooming carriage or groomer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features and advantages of the present invention will become apparent from the following description of non-limiting embodiments of the present invention with reference to the accompanying drawings, in which:

[0024] Figure 1 shows a schematic side view of a snow groomer for grooming a ski slope;

[0025] Figure 2 yes Figure 1 an enlarged perspective view of certain components of the snowplow in FIG. 1; namely, a snowplow assembly having a frame and a lifting device and a pair of stabilizing devices according to the present invention; the rest of the vehicle has been omitted for convenience;

[0026] Figure 3 and Figure 4 Two different positions of the snow plow assembly relative to the main frame are shown, namely a lowered working position and a raised inactive position;

[0027] Figure 5 Shows Figure 2 an enlarged view of some of the components; namely, the frame and the lifting device and a pair of stabilizing devices according to the present invention;

[0028] Figure 6 A schematic diagram showing a hydraulic circuit for the coordinated operation of the lifting device and the stabilizing device;

[0029] Figure 7 A sectional view of a possible embodiment of a stabilization device according to the invention is shown. DETAILED DESCRIPTION

[0030] A preferred embodiment of the present invention, namely, a snowplow equipped with a snowplow assembly that can be lifted by a pair of stabilizing devices that are constructed to stabilize (i.e., lock in space) the snowplow assembly when the snowplow assembly is raised, will be described below with reference to the accompanying drawings listed above.

[0031] Reference Figure 1, which shows a schematic diagram of a snowplow 1, i.e. a tracked vehicle that can be equipped with the technical solution described in the present invention. The snowplow 1 is a tracked vehicle and is motorized to move on a ground 2 in a direction of movement 3. As mentioned above, the term "ground" refers to a variety of different surfaces on which the vehicle travels. That is, usually, during normal use, the ground is in this case snow, but the ground can nevertheless also be a different contact surface, even a hard surface. In fact, usually, the snowplow is located on the snow in the ideal state of its operation at certain times, while at other times it may be located on an icy or hard surface, and the present invention also extends to other vehicles that are constructed for grooming other types of ground. Of course, the direction of movement 3 can also be different from the direction represented, i.e., for example, the snowplow 1 can also move in the opposite direction. Figure 1 The snow groomer 1 in the embodiment includes a rear snow plow assembly 30 (referred to as a “working assembly”) configured to work on snow 2, a front push blade 29 for moving large amounts of snow, and a winch assembly 31. Figure 1 The snow groomer 1 in the embodiment also includes a supporting frame or main frame 4, a cab 5 mounted on the supporting frame 4, and two track sections 6 mounted on opposite sides of the supporting frame 4. Each track section 6 includes a plurality of tracks 10 wrapped between the front wheels 9 and the rear wheels 8. In addition, each track section 6 includes a plurality of crossbars 11 fixed to the tracks 10. The direction defined by the direction of movement of the tracks 10 will be indicated as the longitudinal direction 3 in the following description, while the rotation axes of the wheels 8, 9 define a transverse direction 7 orthogonal to the longitudinal direction 3.

[0032] Figure 2 yes Figure 1 1 is an enlarged perspective view of certain components of a snow groomer, namely, a snow plow assembly 30. In this example, the snow plow assembly includes a snow plow device 12 and a groomer device 13. Other construction details of the snow plow assembly 30 are omitted because they are known to those skilled in the art and the composition of the snow plow assembly does not constitute a limitation of the present invention. In other words, the snow plow assembly can be of any type, as it can also be a working component other than a snow plow assembly. In order to integrate a working component into the present invention, the only limitation required of the working component is that it should be selectively raiseable and lowerable relative to the ground. To this end, Figure 2 The snow plow assembly 30 is connected to or includes a lifting frame 14 on the side opposite to the slide 13, and is coupled to the main frame 4 through the lifting frame. A lifting arm 15 is provided between the main frame 4 and the lifting frame 14, which is a device configured to lift and lower the snow plow assembly 30. A pair of stabilizing devices 16 are provided between the lifting frame and the snow plow assembly 30. The formation of these stabilizing devices 16 according to the present invention will be described in detail below. Figure 2 , the rest of the vehicle 1 is omitted for convenience.

[0033] Figure 3 and Figure 4 Two different positions of the snow plow assembly 30 relative to the main frame, ie, relative to the ground 2, are shown. Figure 3 The snow plow assembly 30 is shown in a lowered operating position, with the snow plow 12 and groomer 13 acting on the ground 2 (ie, snow). Figure 4 The snow plow assembly 30 is shown in a raised inactive position, wherein the snow plow 12 and the groomer 13 are in a position not engaging the ground 2. In this example, the lifting device 15 is a hydraulic actuator configured to raise and lower the snow plow assembly 30 by rotating about an axis parallel to the transverse direction 7. Figure 3 The lifting device 15 comprises a cylinder 17 housing a mobile piston 18 driven by a fluid supplied into the cylinder. The axis of rotation about which the snowplough assembly 30 is raised and lowered corresponds to the coupling point between the lifting device 15 and the main frame 4. This point is indicated by reference numeral 19. Figure 4 As can be seen in FIG. 1 , the piston 18 is located relatively deep in the cylinder 17 due to its operation and the lifting of the snow plow assembly 30. The stabilizer 16 is configured so that Figure 3 In the lowered first working position, the movement of the snowplow assembly 30 relative to the main support frame is not inhibited, so the snowplow assembly 30 can "freely" rotate about the longitudinal axis 3 and the transverse axis 7. In fact, in this position, the snowplow assembly 30 must move as freely as possible to better adapt to the changing configuration of the snow 2 to be groomed. However, in Figure 4 In the embodiment of the present invention, the stabilizers 16 act on the snowplow assembly 30 to "stabilize" its movement, that is, they are configured to prevent or provide significant resistance to movement of the snowplow assembly 30 relative to the main support frame 4. Thus, the term "stabilize" has the meaning of inhibiting or opposing the typical movement that the snowplow assembly 30 is allowed to make when it acts on the ground 2.

[0034] Figure 5 Shows Figure 2 In particular, Figure 5 In the embodiment of the present invention, most of the snow plow assembly 30 has been removed and only the portion coupled to the stabilizer 16 is shown. According to a main aspect of the present invention, the stabilizer 16 is of the hydraulic type and Figure 5 Also shown is a hydraulic circuit 20 for supplying the stabilizing device 16. In this example, the hydraulic circuit 20 connects the lifting device 15 to the stabilizing device 16 (both of which are hydraulically operated) so that they operate in coordination.

[0035] Figure 6A schematic diagram of the hydraulic circuit 20 of the previous figure is shown. As will be further explained in detail in the description of the subsequent figures, the stabilizer 16 of this example is a double-acting hydraulic actuator. That is, each stabilizer 16 includes a cylinder 32 accommodating a moving piston 33, which defines a main chamber 21a and a sub-chamber 21b for supplying or discharging a pressurized fluid (e.g., oil) in the cylinder 32. The sub-chamber is a chamber that accommodates a portion of the rod of the piston 33. Similarly, the lifting device 15 also defines a main chamber 22a and a sub-chamber 22b. Figure 6 As can be seen in the drawing, the larger chambers 21a of the two stabilizers 16 are connected to each other and also to the smaller secondary chamber 22b of the lifting device 15 of the lifting frame 14. Due to this connection, during the lifting stroke, the oil present in the secondary chamber 22b of the lifting device 15 automatically flows into the main chamber 21a of the stabilizer 16, thereby stabilizing the snow plow assembly 30. The secondary chamber 21b of the stabilizer 16 is connected to the secondary chamber 21b of the stabilizer 16. Figure 6 The fuel tank is indicated by line 24. Figure 3 In the working position, the main chamber 21 a of the stabilizer 16 is emptied so that the snow plough assembly can conform to the ground as best as possible. Figure 6 Also shown are a first valve 25 and a second valve 26 for controlling the flow of oil between the oil tank 24 and the hydraulic actuators 15 , 16 .

[0036] In the future, it can also be controlled by a separate valve or hydraulic system. Arrow F1 indicates the flow of oil from the oil tank to the valve 26; arrow F2 indicates the flow of oil from the valve 26 to the main chamber 22a of the lifting device 15; arrow F3 indicates the flow of oil from the secondary chamber 22b of the lifting device 15 to the main chamber 21a of the stabilizer 16; arrow F4 indicates the flow of oil from the secondary chamber 21b of the stabilizer 16 to the oil tank 24.

[0037] at last, Figure 7 A cross-sectional view of a possible embodiment of a stabilizing device 16 according to the invention is shown. The figure shows in detail the supply F3 of oil into the main chamber 21a and the discharge F4 of oil from the secondary chamber 21b. The figure also shows the presence of a pin 34 around the head of the piston 33, which acts as a damping element in the transition between activation and deactivation of the stabilizing device 16.

[0038] Of course, both the lifting device 15 and the stabilizing device 16 comprise ends configured to be coupled to the respective frames to allow correct operation. In the example shown, these ends are joints.

[0039] Finally, it is evident that modifications and variations may be made to the invention described herein without departing from the scope of the appended claims.

Claims

1. A tracked vehicle for finishing ground, the vehicle (1) comprising: - a main support frame (4) configured to support the crawler tracks (6) at the sides and the cab (5) at the top; - at least one working assembly (30) coupled to the main support frame (4) at the front and rear and configured to modify the ground (2) during movement of the vehicle (1); - a lifting device (15) for the working assembly (30), which is configured to selectively switch the working assembly (30) between a first lowered working position in which the working assembly is in contact with the ground (2) and a second raised inactive position in which the working assembly is not in contact with the ground (2); - at least one hydraulic stabilizing device (16) acting on the working assembly (30) and configured so as not to inhibit the movement of the working assembly (30) relative to the main support frame (4) in the first, lowered, working position and to stabilize the working assembly (30) relative to the main support frame (4) with a greater resistance to movement in the second, raised, inactive position.

2. The vehicle according to claim 1, wherein: The hydraulic stabilizing device (16) is a double-acting hydraulic actuator.

3. The vehicle according to claim 2, wherein: The double-acting hydraulic actuator comprises a cylinder (32) accommodating a moving piston (33), within which a main chamber (21a) selectively filled and emptied with a driving fluid is arranged.

4. The vehicle according to claim 3, wherein: The cylinder (32) houses a second chamber (21b) configured to allow fine adjustments even when the main chamber (21a) is filled.

5. The vehicle according to claim 1, wherein: The lifting device (15) is a hydraulic actuator comprising a cylinder (17) which houses a moving piston (18) driven by a fluid.

6. The vehicle according to claim 5, wherein: The operation of the lifting device (15) and the operation of the hydraulic stabilizing device (16) are coordinated.

7. The vehicle according to claim 6, wherein: The vehicle (1) comprises a hydraulic circuit (20) which connects the lifting device (15) to the hydraulic stabilizing device (16) so that the operation of the hydraulic stabilizing device (16) is linked to the operation of the lifting device (15).

8. The vehicle of claim 1, wherein: The vehicle comprises a lifting frame (14) located between the main support frame (4) and the working assembly (30), the lifting device (15) extending between the main support frame (4) and the lifting frame (14), and the hydraulic stabilizing device (16) extending between the lifting frame (14) and the working assembly (30).

9. The vehicle according to claim 8, wherein: The lifting frame (14) and the working assembly (30) are formed as one body.

10. The vehicle of claim 1, wherein: The vehicle (1) is a snowplow and the working assembly (30) includes a snowplow (12) and a groomer (13).

11. The vehicle according to any one of claims 1 to 10, wherein: The vehicle (1) is a snow groomer for grooming ski slopes.

12. The vehicle according to any one of claims 1 to 10, wherein: The working component (30) is a snow plow component.

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