Snow clearing device

Abstract

A snow-plough blade group for absorbing lateral impacts comprising: a first and a second snow-removing blade; a first support bearing the blades; the second blade being mobile with respect to the first support between a first position, in which the blades identify a first snow-removing surface, and a second position in which the blades identify a second snow-removing surface larger than the first one; a second support hinged to the first support; a first hydraulic cylinder connected between the first and second support for orientating the first support with respect to the second support; a discharge of liquid in overpressure; bypass valve means connecting the first hydraulic cylinder with the discharge, which bypass valve means are configured such that when the pressure in the first hydraulic cylinder exceeds a threshold value, the bypass valve means place the first hydraulic cylinder in liquid communication with the discharge; characterized in that a sensor detects a position assumed by the second blade; and the bypass valve means vary the threshold value according to the sensor reading.

Claims

1. A snow-plough blade group for absorbing lateral impacts, the snow-plough blade group having a variable snow removing surface for absorbing lateral impacts and comprising: a first snow-removing blade; a second snow-removing blade; a first support bearing the first snow-removing blade and the second snow-removing blade; the second snow-removing blade being mobile with respect to the first support between a first position, in which the first snow-removing blade and the second snow-removing blade identify a first snow-removing surface, and a second position in which the first snow-removing blade and the second snow-removing blade identify a second snow-removing surface which is larger than the first snow-removing surface; a second support which is hinged to the first support; a first hydraulic cylinder which is connected between the first support and the second support for orientating the first support with respect to the second support; a discharge of liquid in overpressure; a bypass valve means which connect the first hydraulic cylinder with the discharge of liquid in overpressure, which the bypass valve means are configured such that when the pressure of the liquid contained in the first hydraulic cylinder exceeds a threshold pressure value, due to a lateral impact on the second snow-removing blade the bypass valve means places the first hydraulic cylinder in liquid communication with the discharge of liquid in overpressure, thus modifying the orientation of the first support, of the first snow-removing blade and of the second snow-removing blade with respect to the second support; further comprising a sensor which detects a position assumed by the second snow-removing blade with respect to the first support; and wherein the bypass valve means vary the threshold pressure value according to the sensor reading.

2. The snow-plough blade group of claim 1, wherein: the bypass valve means comprises: a switch having at least three ways comprising a first way, a second way, a third way and a lever which is mobile between a first position, in which the lever places the first way of the switch in liquid communication with the third way of the switch, and a second position, in which the lever places the second way of the switch in liquid communication with the third way of the switch; a first single-directional bypass valve having a first threshold pressure value, which first single-directional bypass valve has at least a first way and a second way and is connected to the first way of the switch; and a second single-directional bypass valve having a second threshold pressure value which is greater than the first threshold pressure value, which second single-directional bypass valve has at least a first way and a second way and is connected to the second way of the switch; the sensor comprises: a body having a shaped profile, which body is fixed to the second snow-removing blade; and a cursor which couples with the shaped profile of the body in order to activate the lever of the switch; the snow-plough blade group being configured such that when the second snow-removing blade is in the first position the lever of the switch is in the first position, connecting the first hydraulic cylinder with the discharge of liquid in overpressure via the first single-directional bypass valve; and when the second snow-removing blade is in the second position the lever of the switch is in the second position, connecting the first hydraulic cylinder with the discharge of liquid in overpressure via the second single-directional bypass valve.

3. The snow-plough blade group of claim 2, wherein: the first way of the first single-directional bypass valve is connected to the discharge of liquid in overpressure; the second way of the first single-directional bypass valve is connected to the first way of the switch; the first way of the second single-directional bypass valve is connected to the discharge of liquid in overpressure; the second way of the second single-directional bypass valve is connected to the second way of the switch; the third way of the switch is connected to the first hydraulic cylinder.

4. The snow-plough blade group of claim 2, wherein the shaped profile is a rail and wherein the cursor comprises an idle roller which runs along the rail which rotatably bears the idle roller and which activates the lever of the switch.

5. The snow-plough blade group of any one of the preceding claim 1, comprising a second hydraulic cylinder which is connected between the first support and the second support such as to orientate the first support with respect to the second support; wherein the discharge of liquid in overpressure is defined by the chamber of the second hydraulic cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Specific embodiments of the invention will be described in the following of the present description, according to what is reported in the claims and with the aid of the accompanying tables of drawings, in which:

(2) FIGS. 1-4 schematically illustrate a snow-plough blade group of known type in various working positions;

(3) FIG. 5 illustrates a portion of a hydraulic diagram of the snow-plough blade group of FIG. 1-4;

(4) FIG. 6 is a perspective view of the snow-plough blade group object of the present invention, in a first working position;

(5) FIG. 7 is a view of a detail in larger scale of the snow-plough blade group of FIG. 6 when the snow-plough blade group is in the first working configuration;

(6) FIG. 8 is a view of the larger-scale detail of the snow-plough blade group of FIG. 6, when the snow-plough blade group is in a second working configuration;

(7) FIG. 9 is a view of the larger-scale detail of the snow-plough blade group of FIG. 6 when the snow-plough blade group is in a third working configuration;

(8) FIG. 10 is a view of the larger-scale detail of the snow-plough blade group of FIG. 6 when the snow-plough blade group is in a fourth working configuration.

(9) FIG. 11 illustrates an embodiment of a portion of hydraulic diagram of the snow-plough blade group of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

(10) With reference to FIGS. 6-11, reference numeral (100) relates to a snow-plough blade group for absorbing lateral impacts, object of the present invention.

(11) The snow-plough blade group (100) has a variable snow-removing surface for absorbing lateral impacts and comprises: a first snow-removing blade (3); a second snow-removing blade (4); a first support (5) bearing the first snow-removing blade (3) and the second snow-removing blade (4). The second snow-removing blade (4) is mobile with respect to the first support (5) between a first position (H1) (illustrated in FIGS. 6, 7), in which the first snow-removing blade (3) and the second snow-removing blade (4) identify a first snow-removing surface (6), and a second position (H2) (FIG. 10) in which the first snow-removing blade (3) and the second snow-removing blade (4) identify a second snow-removing surface (7) which is larger than the first snow-removing surface (6). The snow-plough blade group (100) further comprises: a second support (8) (FIG. 6) which is hinged to the first support (5); a first hydraulic cylinder (10) which is connected between the first support (5) and the second support (8) for orientating the first support (5) with respect to the second support (8); a discharge (15) of liquid in overpressure; bypass valve means (12) which connect the first hydraulic cylinder (10) with the discharge (15) of liquid in overpressure, which bypass valve means (12) are configured such that when the pressure of the liquid contained in the first hydraulic cylinder (10) exceeds a threshold pressure value, due to a lateral impact on the second snow-removing blade (4), the bypass valve means (12) place the first hydraulic cylinder (10) in liquid communication with the discharge (15) of liquid in overpressure, thus modifying the orientation of the first support (5), of the first snow-removing blade (3) and of the second snow-removing blade (4) with respect to the second support (8); a sensor (17) which detects a position assumed by the second snow-removing blade (4) with respect to the first support (5). The bypass valve means (12) vary the threshold pressure value according to the sensor (17) reading.

(12) A lateral impact is an impact (for example against a pavement or a kerb) which occurs at the externally-projecting end (27) of the second snow-plough blade (4); this type of impact is very frequent as the operator driving the work vehicle, which for example bears the snow-plough blade group (100), has greater difficulty in identifying (and therefore avoiding) obstacles which are located at the marginal edges of his or her visual field.

(13) The second support (8) can be borne by a work vehicle that is not illustrated: for example the second support (8) is fixed to the frame of the work vehicle.

(14) The snow-plough blade group (100) preferably comprises a second hydraulic cylinder (11) which is connected between the first support (5) and the second support (8) such as to orientate the first support (5) with respect to the second support (8); wherein the discharge (15) of liquid in overpressure is defined by the chamber (15) of the second hydraulic cylinder (11).

(15) The bypass valve means (12) preferably comprise: a switch (21) having at least three ways comprising a first way (22), a second way (23), a third way (24) and a lever (25) which is mobile between a first position (FIG. 11), in which the lever (25) places the first way (22) of the switch (21) in liquid communication with the third way (24) of the switch (21), and a second position (not illustrated), in which the lever (25) places the second way (23) of the switch (21) in liquid communication with the third way (24) of the switch (21); a first single-directional bypass valve (18) having a first threshold pressure value, which first single-directional bypass valve (18) has at least a first way (29) and a second way (30) and is connected to the first way (22) of the switch (21); and a second single-directional bypass valve (19) having a second threshold pressure value which is greater than the first threshold pressure value, which second single-directional bypass valve (19) has at least a first way (31) and a second way (32) and is connected to the second way (23) of the switch (21). The sensor (17) comprises: a body (20) having a shaped profile (33), which body (20) is fixed to the second snow-removing blade (4); and a cursor (26) which couples with the shaped profile (33) of the body (20) in order to activate the lever (25) of the switch (21). The snow-plough blade group (100) is configured such that: when the second snow-removing blade (4) is in the first position (H1) the lever (25) of the switch (21) is in the first position, connecting the first hydraulic cylinder (10) with the discharge (15) of liquid in overpressure via the first single-directional bypass valve (18); when the second snow-removing blade (4) is in the second position (H2) the lever (25) of the switch (21) is in the second position, connecting the first hydraulic cylinder (10) with the discharge (15) of liquid in overpressure via the second single-directional bypass valve (19).

(16) In greater detail, and according to an embodiment illustrated in FIG. 11: the first way (29) of the first single-directional bypass valve (18) is connected to the discharge (15) of liquid in overpressure; the second way (30) of the first single-directional bypass valve (18) is connected to the first way (22) of the switch (21); the first way (31) of the second single-directional bypass valve (19) is connected to the discharge (15) of liquid in overpressure; the second way (32) of the second single-directional bypass valve (19) is connected to the second way (23) of the switch (21); the third way (24) of the switch (21) is connected to the first hydraulic cylinder (10).

(17) The shaped profile (33) is preferably a rail (34) and the cursor (26) comprises an idle roller (35) which runs along the rail (34) and a command rod (36) which rotatably bears the idle roller (35) and which activates the lever (25) of the switch (21).

(18) In the illustrated figures the second snow-plough blade (4) can slide with respect to the first snow-plough blade (3); alternatively, the second snow-plough blade (4) can for example rotate with respect to the first snow-plough blade (3) about a hinge axis (this solution is not illustrated).

(19) The foregoing has been described by way of non-limiting example and any eventual constructional variants are considered to fall within the protective scope of the present technical solution, as claimed in the following.