FIELD OF THE INVENTION
The present invention relates in general to a lever lock for use in mechanically controlling a
hydraulic valve spool of the type present in a directional control valve and commonly
associated with auxiliary hydraulically operated machinery and more particularly to a
mechanism to lock the lever attached to said directional control valve at a fixed position for
assistance in modern farm technology such as through implementation of laser leveler
application.
BACKGROUND OF THE INVENTION
Most of today's heavily equipped machinery, such as a front end bucket loader, an earth
mover, and an excavator, to name a few, operate principally by means of hydraulic fluid flow
sustainably operating under moderate to high pressures. Pressurized fluids is preferentially
controlled by means of one or more directional control valves (DCV) each being equipped
with hydraulic valve spools and distributed through a defined network of hoses and tubes.
The hydraulic valve spool of one particular type noted in the art can be generally described
as comprising a central (neutral) position maintained with springs. Depending on the
manufacturer's design configuration, sliding the valve spool to a general fore position opens
the valve to permit hydraulic fluid to flow to the actuator and from the actuator to the
reservoir. Conversely, when the valve spool is allowed to return to a neutral (center)
position, the actuator fluid paths are closed, locking the valve in position. Directional control
valves are usually designed to be stackable, with one control valve serving each hydraulic
cylinder and one fluid input supplying all the control valves in the stack. The valve spool
positions noted above might be actuated by means of a mechanical lever control of the
particular type.
With increasing trend of farm tech prosperity, usage of DCV is increasing which is used for
auxiliary hydraulic operated machines such as Tipping trolley application, tractor mounted
combines, Dozer, Loaders & laser leveler application etc. Based on the application the
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hydraulic spool-type directional control valves such as herein concerned also have been
provided with various mechanisms to define certain operating positions of a valve member
thereof, and/or to releasably hold the valve member in one or more of those positions until
the operator of the valve manually actuates it to another position, such as to neutral.
Detent mechanisms are among the more common of such expedients for defining and/or for
releasably holding the valve member against biased return to its neutral position. For
example, US4049235A discloses use of detents for locking movable elements. Despite the
fact that detent mechanisms have achieved a notable state of simplicity, they nevertheless
require a number of machining operations and extra parts such as balls and springs to act on
the balls, all of which add to the cost of manufacture and complicates valve assembly
procedures. The art offers solutions to the problem posed by using detent mechanism. For
instance, in US3677281A is provided a toggle joint so associated with the valve element of a
control valve that the knee of the toggle joint is carried a slight distance past dead center to a
defined toggle cocked position in consequence of actuation of the valve member to one of its
operating positions, and which toggle joint is releasably maintained in cocked condition
under the force of the return spring acting on the valve member.
Further, DE3909015A1 discloses a device for locking an actuating lever for controlling two
directional control valves. The said locking device provides for two locking devices, situated
apart but in immediate proximity to one another, to be arranged for both pivoting regions of
the actuating lever, each locking device essentially consisting of bearing bolt and shaft,
respectively, the holding notch, as well as the pin.
Furthermore, JP2007195465A discloses a horizontal control mechanism of the left and right
wheels to relatively move up and down as the left and right vehicle body is horizontal relates
transplantation machine provided. Disclosed mechanism operates the lift lever in the raised
position the lock lever at the same time automatically switched to the unlocked position from
the locked position, even in the middle of planting work to lower the vehicle body, the
horizontal control to be able to unlock the mechanism easily, even if you unlock the
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horizontal control mechanism in the middle of planting work, prevent the planting no part in
the field occur is interrupted in the middle of the planting work it is those who can be so.
Further, JP2001026950A relates to a locking mechanism of the hydraulic control lever to
perform the operation of the working machine to be mounted on a swivel working vehicle.
Said mechanism provides a structure of hydraulic operation lever part for swivel working
machine by forming a locking groove for retaining the rotated position of the lock lever in a
guide hole in which the swivel fulcrum part of the lock lever slides according to the rotating
operation.
Furthermore, US4526055A is directed particularly for manually controlling lever
arrangements for the control of one or more hydraulic valves. For example, control lever
arrangements employed to operate the hydraulic valves which control loaders and diggers of
industrial tractors. When used in such an application the locking device may be arranged to
lock the or each associated control valve in its neutral position thus preventing operation of
the loader or digger.
From the aforesaid discussions, it would be evident that based on the said applications it is
desirable to have a valve member in particular position for example, such as up or raised
position, neutral position , hoist position and working position.
In laser land leveling application which is a revolutionary technology in modern farming
implemented to enhance use efficiency of water and fertilizer nutrients, and to improve the
crop stand and yields i.e. technology finds use in conservation of irrigation water. Laser
leveling is a process of smoothening the land surface (± 2 cm) from using laser equipped
drag buckets to achieve precision in land leveling. Precision land leveling involves
converting the fields in such a way as to create a regular slope. A laser-controlled land
leveling system consists of the following five major components: Drag bucket, Laser
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transmitter, Laser receiver, Control box and the Hydraulic system which is to supply oil to
raise and lower the leveling bucket.
Further, in surveying and construction, the laser level is a control tool consisting of a laser
beam projector that can be affixed to a tripod, which is leveled according to the accuracy of the
device and which projects a fixed red or green beam along the horizontal and/or vertical axis A
tower-mounted laser level is used in combination with a sensor on a wheel tractor-scraper in the
process of land laser leveling to bring land (for example, an agricultural field) to near-flatness
with a slight grade for drainage.
Conventionally, the user, in the event of keeping the DCV lever in the “up” position, had to
either keep holding the lever in the desired position using his hands or had to tie said DCV
lever with a cloth or a rope so that the laser leveller works fine (Fig. 1) which is out rightly
inconvenient and irritating for the user.
None of the prior art discloses a mechanism or structure which keeps the directional control
valve (DCV) lever in a fixed position. For example, an “up” position as desired in laser
leveler application. Thus, there is a dire need to develop a mechanical locking technique for
a lever attached to the hydraulic spool-type directional control valve to be implemented in
said applications such as laser leveler.
OBJECTS OF THE INVENTION
An object of the invention is to overcome the aforementioned and other drawbacks existing
in prior art devices and arrangements.
Another object of the present invention is to develop a Mechanical Locking device for lever
of hydraulic spool-type Directional control valve (DCV) in laser leveler application to keep the
DCV lever in an “up” position.
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SUMMARY OF THE INVENTION
The present application discloses a device for mechanical locking for lever of hydraulic spooltype
Directional control valve (DCV) in a fixed position as described in Fig. 2. In a preferred
form, in laser leveler application to keep the DCV lever in an “up” position, the proposed
mechanism finds useful. Further, in an aspect the locking device includes a mounting
assembly having a DCV mounting bracket integrally connected to a mounting plate. In one
aspect, the DCV mounting bracket is configurably arranged to fit about and over a
mountable portion of the hydraulic valve spool-type DCV. In another aspect, the DCV
mounting bracket includes a first pin and a threaded pin fixedly attached thereto and
extending outward therefrom. In another aspect, a sliding rod assembly is implemented for
locking the lever in the fixed position relative to said mounting assembly. In an aspect, the
sliding rod assembly includes a sliding rod arranged to hold the lever in the fixed position.
Further, the sliding rod is fixedly attached to first pin and threaded pin on the DCV mounting
bracket using a locking plate and a wing nut.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above brief description, as well as further objects, features and advantages, of the
present invention can be fully appreciated by reference to the following detailed description.
These features of the present invention will become more apparent upon reference to the
drawings, wherein:
Fig. 1: Illustrates the prior art technique for holding the hydraulic spool-type DCV lever.
Fig. 2: Illustrates Mechanical locking setup for the hydraulic spool-type DCV lever
according to the preferred embodiment of the present invention.
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DETAILED DESCRIPTION OF THE INVENTION
Although the disclosure hereof is detailed and exact to enable those skilled in the art to
practice the invention, the physical embodiments herein disclosed merely exemplify the
invention which may be embodied in other specific structure. While the preferred
embodiment has been described, the details may be changed without departing from the
invention, which is defined by the claims.
It will be apparent, however, to one of ordinary skill in the art that the present invention may
be practiced without specific details of the well known components and techniques. In other
instances, well known components or methods have not been described in detail but rather in
a block diagram in order to avoid unnecessarily obscuring the present invention. Further
specific numeric references should not be interpreted as a literal sequential order. Thus, the
specific details set forth are merely exemplary. The specific details may be varied from and
still be contemplated to be within the spirit and scope of the present invention. The features
discussed in an embodiment may be implemented in another embodiment. The term coupled
is defined as meaning connected either directly to the component or indirectly to the
component through another component.
The present invention will be described in detail below with reference to an embodiment as
shown in the drawing.
Turning now to the drawings, and referring first to FIG. 1, the user, in the event of keeping
the DCV lever (1) in the “up” position (operating mode), needs to in one aspect, either keep
holding the lever in the desired position using his hands or in second aspect, has to tie said
DCV lever (1) with a cloth or a rope (as shown in Fig. 1). The reference to the conventional
system is made in order to better distinguish the present inventive disclosure discussed later
in greater detail. The details of the conventional mechanism are well-known in the art, and
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therefore, are described herein only in the detail required to fully disclose the present
invention.
Further, improvement to the conventional techniques is vividly illustrated in Fig.2. In Fig.2,
a mechanical lock setup for Directional Control Valve (DCV) lever (1) according to the
present invention is shown. A Directional Control Valve (2) is mounted on a DCV mounting
bracket (6) with the use of nuts and bolts (not shown in the Fig.). In an embodiment, a DCV
lever (1) is operably connected to said DCV (2). In another embodiment, the sliding rod (3)
is connected to said DCV mounting bracket (6) using pins which in the present embodiment
is first pin (7) and threaded pin (8) which are welded on the mounting bracket (6), a locking
plate (5) and a wing nut (4). In an embodiment, Wing nut (4) is loosened and the sliding rod
(3) is moved vertically up to hold DCV lever (1) in up (operating) condition, thereby the
locking plate (5) presses the sliding rod (3) against said DCV mounting bracket (6) with the
help of a wing nut (4). In another embodiments, locking may also be achieved by utilization
of spring (torsional or compression), linkages and by implementation of wires.
The Sliding rod (3) can be tightened & loosened via the wing nut (4) enabling the user to
lock and unlock the DCV lever (1) at desired position/fixed position/desired fixed position of
the DCV lever (1), which rests on the sliding rod (3), as per the requirement and to use it
efficiently and hence can be held at a fixed position (“UP”) very easily and conveniently. In
an embodiment, adjusting the locking plate (5) is achieved by releasing and turning the wing
nut (4).

WE CLAIM:
1. A locking device for mechanically locking a DCV lever (1) in a fixed position for
application to modern farm technology, wherein the DCV lever (1) is integrally
connected to a hydraulic spool-type directional control valve (DCV), said locking
device comprising:
a mounting assembly having a DCV mounting bracket (6) integrally connected to a
base plate (9), whereby said DCV mounting bracket (6) is configurably arranged to fit
about and over a mountable portion of the hydraulic valve spool-type DCV (2), said
DCV mounting bracket (6) having two apertures extending thereby to restrict
movement of a sliding rod (3) in a vertical direction, said DCV mounting bracket (6)
further having first pin (7) and threaded pin (8) fixedly attached thereto and extending
outward therefrom;
a sliding rod assembly for locking the DCV lever (1) in the fixed position relative to
said DCV mounting bracket (6), said sliding rod assembly comprising:
a sliding rod (3) arranged to hold the DCV lever (1) in the fixed position,
wherein said sliding rod (3) is fixedly attached to first pin (7) and threaded pin (8) on
the DCV mounting bracket (6).
2. The device of claim 1, wherein said sliding rod (3) is fixedly attached to first pin (7)
and threaded pin (8) on the DCV mounting bracket (6) using a locking plate (5) and at
least one of wing nut (4), spring, linkage and wire.
3. The device of claim 1, wherein the locking plate (5) is adjustably arranged for locking
the sliding rod (3) against the DCV mounting bracket (6) of the mounting assembly.
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4. The device of claim 1 and 2, wherein the locking plate (5) is adjustably arranged for
locking the sliding rod (3) against the DCV mounting bracket (6) comprises adjusting
the locking plate (5) by releasing and turning the wing nut (4).
5. The device of claim 3, wherein the adjusting of the locking plate (5) further comprises
at least tightening or loosening the sliding rod (3).
6. The device of claim 1 and 2, wherein the locking plate and the wing nut (4) is
adjustably arranged on the threaded pin (8) which is being fixedly attached to the
DCV mounting bracket (6).
7. The device of claim 1, wherein the fixed position represents only up and/or raised
position.
8. The device of claim 1, wherein the application to modern farm technology is laser
leveler.