Earthworking machine of the loader type
AssigneePoclain
InventorVictor Yeou
Life of this patent
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Abstract
The invention relates to a hydraulic loader comprising a boom, a balance beam and a bucket for loading material, boom jacks and balance beam jacks being coupled between the frame and the boom and between the boom and the balance beam. A secondary jack is also coupled between the frame and the boom and comprises an active chamber, while a first conduit connects this active chamber to the extension chamber of the balance beam jack and a first cut-off valve is disposed in this first conduit, establishing, in its first position, communication of the two sections of the first conduit which are connected thereto, isolating, on the contrary, in its second position, these two sections. One application of the invention is the production of a powerful and efficient loader.
Claims13
In an earthworking machine of the loader type, constituted by:
- a frame,
- a boom mounted to pivot with respect to the frame about a first axis,
- a balance beam mounted to pivot with respect to the boom about a second axis, the first and second axes being parallel to each other,
- a material loading bucket coupled to the balance beam, preferably by means of a third pivot axis and a bucket jack,
- a double-acting, boom jack, coupled between the frame and the boom and comprising a boom raising chamber and a boom lowering chamber,
- double-acting, balance beam jack, coupled between the boom and the balance beam and comprising a chamber for extension of the balance beam with respect to the boom and a chamber for return of the balance beam with respect to this boom,
- a circuit for supplying said jacks with pressurised fluid comprising:
- at least one source of pressurised fluid, and
- at least two three-way control valves disposed as follows:
- a boom control valve between the boom jack and a source of fluid under pressure and a balance beam control valve between the balance beam jack and a source of fluid under pressure, each capable of selectively placing one of the chambers of the corresponding jack in communication with the source of fluid under pressure, with an exhaust or of isolating this chamber from said source of fluid under pressure and, correlatively, of placing the other chamber in communication with the exhaust, with the source of pressurised fluid, or of isolating this other chamber from said source of pressurised fluid, and
- a secondary jack coupled between the frame and the boom and comprising at least one active chamber, a first conduit connects this active chamber of the secondary jack to the chamber for extension of the balance beam jack, a first cut-off valve with at least two positions being disposed in this first conduit, establishing, in its first position, the communication of the two sections of the first conduit connected thereto, but, in its second position, isolating these two sections.
Dependencies are inferred from the claim text.