Patent Application
20100131157
Not applicable.
Not applicable.
Skid steer loaders and multi-terrain loaders are used extensively in construction applications, in agricultural applications, and in other applications where power and versatility are needed. Skid steer loaders and multi-terrain loaders are essentially the same type of machine, with the exception of the ground engagement components. Typically, skid steer loaders move on wheels, while multi-terrain loaders are carried on tracks. However, both types of loaders offer relatively small size and high maneuverability, and can use a wide variety of attachment work tools, making them extremely flexible in application. Skid steer loaders and multi-terrain loaders may be used to dig, to level, to cut, to carry, to load, and to perform any number of other tasks. For each such task, the loader carries a specially designed attachment on the loader arms that extend forward from the loader body.
Skid steer loaders and multi-terrain loaders typically are hydraulically powered. An hydraulic pump, driven by a diesel engine, supplies hydraulic fluid under pressure to various vehicle components. A loader typically has a pair of hydraulic motors that drive the vehicle wheels or tracks. The loader is turned by driving the wheels or tracks at differing speeds. The loader arms that extend forward from the vehicle and to which a bucket, grapple, blade or other attachment is mounted, are also moved by means of hydraulic cylinders that are appropriately configured and controlled by the loader operator. To accomplish this control, the vehicle operator typically uses joy stick controls, or similar controls, in the operator cab.
One significant advantage offered by skid steer loaders and multi-terrain loaders is their ability to carry and operate dozens of different attachments, changing the function of the machine as rapidly as the attachments can be changed. These numerous attachments include augers, bale handlers, brooms, buckets, cold planers, concrete pulverizers, cutters, dozer blades, fertilizer spreaders, fork lift forks, grapples, hitches, landscape rakes, mowers, mulchers, plate compactors, pole claws, pot movers, rock and tree handlers, rock saws, rollers, rotary brooms, shears, snow blowers, splitters, stump grinders, swale blades, tillers, tree spades, trenchers, and winches, among others. Each of these attachments or work tools is unique. Some of the attachments are mounted on the ends of the forward extending loader arms and are simply raised, lowered and reoriented by hydraulic cylinders on the loader that control the position of the arms and the orientation of the attachment coupler at the ends of the arms. Many of the attachments, however, have additional moving elements on the attachment that are powered by one or more hydraulic cylinders carried on the attachment. For example, a grapple attachment may have jaw-like teeth that are moved in relation to each other to grasp an object. One or more hydraulic cylinders are carried on the attachment to effect this movement.
Controlling hydraulic cylinders that are carried on attachments has been problematic. Typically, hydraulic valves on the loader are controlled by an operator to control the flow of hydraulic fluid to the cylinders on an attachment. Because the designs of the various attachments are so diverse, the movement rates of the cylinders on the attachments that is needed or preferred for operation of the attachments may vary significantly. Consequently, the valves must be actuated differently when an operator is controlling various attachments. Movement of an attachment element might, for example, be slower or faster than desired. Similarly, controlling the hydraulic cylinders on the vehicle that control the position of the arms and the orientation of the coupler at the ends of the arms that engages the coupler is also difficult in that the speed of movement and the fluid flow needed to move these cylinders varies among the various attachments. As a consequence, rapid changing of attachments has been made more difficult due to the need to adjust the hydraulics for changes in operation.
In one embodiment, a work attachment is provided for a vehicle. The vehicle has a vehicle body, forward extending support arms, a motor-driven hydraulic fluid pump, hydraulic lines for carrying hydraulic fluid, a hydraulic fluid reservoir, hydraulic cylinders for moving the arms with respect to the body, valves for controlling the supply of hydraulic fluid to the hydraulic cylinders, and controls for controlling the valves. The vehicle further includes a control for providing one or more electrical control signals on a vehicle attachment control line for controlling an attachment. The work attachment is mounted on the forward extending support arms. The work attachment has relatively movable attachment elements and one or more attachment hydraulic cylinders for effecting movement of the attachment elements. Hydraulic fluid lines having quick connect couplings for connection to the hydraulic lines of the vehicle are included on the attachment. An attachment electrical control line for connection to the vehicle attachment control line is included on the attachment. A processing circuit, on the attachment, is responsive to the one or more electrical control signals on the attachment electrical control line for providing one or more valve control signals. Finally, electrically actuated hydraulic valves on the attachment are connected to the hydraulic fluid lines and are responsive to the one or more valve control signals, for controlling the application of hydraulic fluid to the one or more attachment hydraulic cylinders in response to the one or more valve control signals.
The work attachment can be any of a number of different hydraulically powered devices. For example, the work attachment can be an auger, a bale handler, a broom, a bucket, a cold planer, a concrete pulverizer, a cutter, a dozer blade, a fertilizer spreader, fork lift forks, a grapple, a hitch, a landscape rake, a mower, a mulcher, a plate compactor, a pole claw, a pot mover, a rock and tree handler, a rock saw, a roller, a rotary broom, a shear, a snow blower, a splitter, a stump grinder, a swale blade, a tiller, a tree spade, a trencher, or a winch.
The processing circuit is responsive to the one or more electrical control signals on the attachment electrical control line. The processing circuit may comprise an amplifier circuit for providing one or more valve control signals of appropriate amplitude to control the operation of the electrically actuated hydraulic valves and the attachment. The valve control signals are preferably specifically matched to the performance characteristics of the valve they control by the amplifier.
In another embodiment, the vehicle has a vehicle body, forward extending support arms, a motor-driven hydraulic fluid pump, hydraulic lines for carrying hydraulic fluid, a hydraulic fluid reservoir, hydraulic cylinders for moving the arms with respect to the body, and a control for providing one or more electrical control signals on a hydraulic cylinder control line for controlling the hydraulic cylinders. A work attachment is mounted on the forward extending support arms. The work attachment includes hydraulic fluid lines having quick connect couplings for connection to the hydraulic lines of the vehicle, an attachment electrical control line for connection to the hydraulic cylinder control line, a processing circuit, responsive to the one or more electrical control signals on the attachment electrical control line, for providing one or more valve control signals, and electrically actuated hydraulic valves, connected to the hydraulic fluid lines on the work attachment. The valves are responsive to the one or more valve control signals, for controlling the application of hydraulic fluid to the hydraulic cylinders on the vehicle body in response to the one or more valve control signals.
A vehicle may comprise a vehicle body, forward extending support arms, a motor-driven hydraulic fluid pump, hydraulic lines for carrying hydraulic fluid, a hydraulic fluid reservoir, hydraulic cylinders for moving the arms with respect to the body, valves for controlling the supply of hydraulic fluid to the hydraulic cylinders, controls for controlling the valves, a control for providing one or more electrical control signals on a vehicle attachment control line for controlling an attachment, a processing circuit, responsive to the one or more electrical control signals on the attachment electrical control line for providing one or more valve control signals, and a work attachment, mounted on the forward extending support arms. A vehicle attachment may have relatively movable attachment elements and one or more attachment hydraulic cylinders for effecting movement of the attachment elements, hydraulic fluid lines having quick connect couplings for connection to the hydraulic lines of the vehicle, and electrically actuated hydraulic valves, connected to the hydraulic fluid lines and responsive to the one or more valve control signals, for controlling the application of hydraulic fluid to the one or more attachment hydraulic cylinders in response to the one or more valve control signals. The processing circuit may comprise an amplifier circuit for providing one or more valve control signals of appropriate amplitude to control the operation of the electrically actuated hydraulic valves and the attachment.
It is an object of the present invention to provide an improved vehicle and work attachment in which hydraulic valves are carried on the attachment, rather than on the vehicle, thereby facilitating changing attachments on the vehicle.
The loader 10 has a vehicle body 20 supported by the tracks 12, and further includes forward extending support arms 22. As seen in
The loader 10 has a hydraulic fluid reservoir 50, and hydraulic cylinders 52 for moving the arms 22 with respect to the body 20. Cylinders 52 typically are operated together so that they can be connected in parallel. Other hydraulic cylinders, not shown, are typically provided to control the orientation of the attachment coupler at the ends of the arms 22. Only one such cylinder is shown in
It will be apparent from a review of
Although the presently preferred embodiments of this invention have been described, it will be understood that within the purview of the invention various changes may be made within the scope of the following claims.
