A vehicle having a lifting arm, which can be used as an agricultural machine

Abstract: A vehicle having a lifting boom, comprising: a load-carrying frame (12) having a front section (12a) and a rear section (12b), a lifting boom (18) extending parallel to the longitudinal axis of the vehicle and articulated to the frame (12) in the rear section (12b), an operating and driving cab (28) placed on a side of the vehicle (18) and an internal combustion engine placed on the opposite side of the boom (18) with respect to the operating cab (28). The rear section (12b) of the frame has a platform on which is intended to be mounted a lifting device (50), in particular operatively associated to a three-point hitch, whereby the vehicle can be used also as an agricultural machine.

Description: The present invention relates to a vehicle having a lifting boom, of the type having the characteristics forming the subject of the preamble of claim 1, which is known from EP-A-0375705 of the same Applicant or from EP-A-0 692 448. Vehicles having a longitudinally arranged telescopic lifting boom, projecting from the front section of the vehicle and articulated to the rear section of the frame have shown a great versatility of use. Remaining the same the basic structure of the vehicle, it is possible to manufacture vehicles intended to be used as aerial platforms, machines for use in building constructions, forklifts, etc. The present invention has the object to provide improvements which permit to further increase the field of use of a vehicle with lifting boom of this type. According to the present invention this object is achieved by a vehicle having the characteristics forming the subject of the main claim. The idea on which the present invention is based consists essentially in providing in the rear section of the frame a platform on which is intended to be mounted a lifting device, in particular operatively associated to a three-point hitch, so that the vehicle can be used also as an agricultural machine. A vehicle with a single telescopic boom and a rear hitch is for example known from GB-A-2 316 057. The vehicle according to the present invention can perform all the functions of a normal agricultural tractor and furthermore as all the advantages deriving by the presence of a lifting boom with high performances. For completing the functions of an agricultural machine, the vehicle according to the invention is preferably provided with a power take-off arranged below the platform adapted to receive the lifting device. In order to permit operation of the power take off directly from the output shaft of the internal combustion engine, the engine is preferably arranged with its longitudinal axis inclined with respect to the longitudinal axis of the vehicle. Further characteristics and advantages of the vehicle according to the present invention will become evident in the course of the detailed description which follows, given purely by way of non-limiting example, with reference to the annexed drawings, in which: figure 1 is a perspective view of a vehicle according to the present invention, figure 2 is a cross-section of the rear part of the vehicle of figure 1, figure 3 is a perspective view of the rear section of the frame of the vehicle of figure 1, without the lifting device, figure 4 is a perspective view similar to figure 3, showing the vehicle provided with a three-point hitch and with the respective lifting device, and figure 5 is a plan view of the vehicle of figure 1. Referring to the drawings, a vehicle according to the present invention is indicated at 10. The vehicle 10 comprises a load bearing frame 12 formed by sturdy welded sheet metal. The frame 12 has a front section 12a and a rear section 12b, carrying respective axles for the front and the rear wheels 14, 16. Preferably, the wheels 14 and 16 have all the same diameter and all of them are both steering and motor-driven. The vehicle 10 is provided with a boom 18 formed by a sturdy box-shaped beam with a rectangular cross-section. The boom 18 can be simple or telescopic and carries at its free end a base 20 for fixing thereto an implement (not shown) which depending on the needs can be a fork, a shovel, an aerial platform, etc. The boom 18 is articulated to the rear section 12b about an horizontal transversal axis 22, formed by a trunnion 24. In a way per se known, a lifting cylinder 26 has its ends articulated to the boom and frame. With particular reference to figure 5, in a lowered position the boom 18 extends parallel to the longitudinal axis of the vehicle and its free end projects beyond the front section 12a. On a side of the longitudinal boom 18 is arranged a control and driving cab 28 wherein are housed an operator seat (not shown) as well as all the mechanical, electrical and hydraulic systems and devices for driving the vehicle and for operating the boom 18 and all the accessory devices of the vehicle 10. Referring always to figure 5, the vehicle 10 is provided with an internal combustion engine 30 which is arranged on the opposite side of the boom 18 with respect to the control cab 28 and is placed between the two wheels 14, 16 of this side of the vehicle. For the reasons which will be clear in the following of the description, the engine 30 is arranged with its longitudinal axis inclined with respect to the longitudinal axis of the vehicle. This inclination can be for example of about 10-30°. For avoiding interference with the lateral visibility of the operator, the whole engine assembly is enclosed in a housing 32 which is located below an horizontal plane tangent to the upper side of the boom 18 when the boom is in its completely lowered configuration. For the same reason, when the boom 18 is in its completely lowered position, it is partially received in a channel-shaped portion 36 of the frame, having a width at least equal to the width of the boom 18. In this way, in its completely lowered position, the boom 18 extends in a substantially horizontal position and lies well below the line of lateral visibility of the operator. Referring now to figure 3, the rear section 12a of the frame has an horizontal platform 38 which extends above the axle 40 of the rear wheels. The platform 38 extends at least partially beyond the rear axle 40 towards the rear of the vehicle and is placed below the trunnion 24 forming the articulation axis of the boom 18. With respect to the trunnion 24, the platform 38 is at least partially shifted toward the rear portion of the vehicle. The platform 38 is laterally delimited by a pair of wall 42 formed by sturdy sheet metal, which form a support for the trunnion 24. The lateral walls 42 are an integral part of the frame and are arranged on the extension of the lateral walls of the channel-shaped portion 36. Each of these lateral walls 42 has a projection 44 arranged backwardly with respect to the rear axle 40. The projections 44 extend below the lower axle 40 and have respective holes 46 whose axes are aligned along a transversal axis. The platform 38 has a machined reference zone where are formed a plurality of holes 48 for fixing a lifting device indicated at 50 in figures 2 and 4. In the example shown in the figures, the rear section 12b is provided with a three-point hitch comprising, in a way per se known, two lower arms 51 and an upper central arm 52. The lifting device 50 is operatively associated to the lower arms 51 of the three-point hitch by means of the respective lifting levers 54 and tie rods 56. The lower arms 51 are articulated in the holes 46 of the projections 44 whereas the central upper arm 52 of the three-point hitch is articulated to a bracket 58 carried by the lifting device 50. In a way per se known, the lifting device 50 is adapted to rotate together the lifting levers 54 about a transversal axis 60 and this rotation raises or lowers the lower arms 51. The lifting device 50 is driven by an hydraulic unit associated with the internal combustion engine 30 and is operated by the operator by means of hydraulic distributors placed in the control cab. The tree-point hitch 51, 52 is a standard attachment which permits to mount on the vehicle 10 any type of agricultural implement and permits the use in the agricultural field of a vehicle whose structure and architecture have been designed with the main object of having a lifting boom with high performances in terms of reachable hights and weight which can be lifted. In this way, the vehicle according to the invention has all the merits and advantages of both a lifting boom device and a modern agricultural tractor. Even if the tree-point hitch is an ideal device for equipping a vehicle according to the present invention, it is not excluded that in alternative the vehicle can be provided with a lifting device of a different nature, such as for example a crane or the like, mounted on the rear platform 38. A particularly advantageous aspect of the horizontal platform 38 according to the present invention consists in that it is arranged so as to be visible by the operator in the cab 28, which considerably simplifies the task of the operator during the operation of the lifting device 50. Furthermore, the vehicle according to the invention is preferably provided with a power take-off 62 placed below platform 38 and also below the rear axle 40. As shown in figure 5, the power take-off 62 is mechanically driven by means of a reduction gear 64 and a cardanic shaft 66 connected, by means of a friction clutch 68, to the rotor of an hydraulic pump 70 connected to the output shaft of the internal combustion engine 30. The inclined disposition of the engine 30 has the purpose to drive mechanically the power take-off 62 and has the further advantage to permit easy access to the engine-pump assembly for maintenance operations by virtue of the fact that such assembly is articulated to the frame about a vertical axis 72 (figure 5) and can be brought in the position shown in broken lines in figure 5, after having removed fixing screws (not shown) and after having disengaged the cardanic shaft 66. The vehicle according to the invention can also be provide with a front power take-off 74 mechanically operated by a transmission shaft 76 connected to the reduction gear 64 of the rear power take-off 62. Another particularly advantageous feature of the vehicle according to the invention consists in that the axles of the front wheels 14 and rear wheels 16 are both free to oscillate with respect to the frame 12 about a longitudinal axis and can be locked in a desired position by means of respective hydraulic cylinders 78, only one of which is visible in figure 1.

Claims: A vehicle having a lifting boom, comprising: a load-carrying frame (12) having a front section (12a) and a rear section (12b) and provided with two axles, respectively front and rear, each having a pair of wheels (14, 16), a lifting boom (18) extending parallel to the longitudinal axis of the vehicle and articulated to the frame (12) in the rear section (12b), an operating and driving cab (28) placed on a side of said boom (18), an internal combustion engine (30) placed on the opposite side of the boom (18) with respect to the operating cab (28) and arranged between the wheels (14, 16) of that side, characterized in that the rear section (12b) of the frame (12) comprises: a platform (38) carrying a lifting device (50), operatively associated to a three-point hitch (51, 52), two lateral walls (42) projecting upwardly from the plane of the platform (38) and carrying the articulation axis (22, 24) of the lifting boom (18), said lateral walls (42) having respective downwardly projecting portions for the articulation of the lower arms (51) of said three-point hitch (51, 52). A vehicle according to claim 1, characterized in that said platform (38) extends along a substantially horizontal plane. A vehicle according to claim 1 or claim 2, characterized in that said platform is placed below the articulation axis (22) of the lifting boom (18). A vehicle according to claim 1, characterized in that said platform is at least partly arranged backwardly with respect to the articulation axis (22) of the lifting boom (18) and projects at least in part towards the rear part of the vehicle beyond the rear axle (40). A vehicle according to claim 1, characterized in that it comprises a power take off (62) arranged below said platform (38). A vehicle according to claim 5, characterized in that said power take-off (62) is mechanically driven by means of a transmission (64, 66, 68) connected to the output shaft of the internal combustion engine (30). A vehicle according to claim 6, characterized in that the internal combustion engine (30) is arranged with its own longitudinal axis inclined with respect to the longitudinal axis of the vehicle (10). A vehicle according to any of the preceding claims, characterized in that the front axle and the rear axle are free to oscillate with respect to the frame (12) about a longitudinal axis and in that said axles can be selectively locked in a predetermined position by means of respective hydraulic actuators (78).

Inventors: GALFRE RENATO, MERLO AMILCARE, GALFRE, RENATO, MERLO, AMILCARE
Applicants: MERLO PROJECT S R L, MERLO PROJECT S.R.L.
Application year: 1998
Main classification: B66F9
IPC codes: B62D49, A01B51, B66F9