U.S. patent application number 11/681391 was filed with the patent office on 2008-09-04 for dozer blade tilt with independent functioning lift cylinders.
This patent application is currently assigned to DEERE & COMPANY. Invention is credited to Jeffrey A. Bauer, Mark John Cherney.
Application Number | 20080210446 11/681391 |
Document ID | / |
Family ID | 39732298 |
Filed Date | 2008-09-04 |
United States Patent
Application |
20080210446 |
Kind Code |
A1 |
Cherney; Mark John ; et
al. |
September 4, 2008 |
DOZER BLADE TILT WITH INDEPENDENT FUNCTIONING LIFT CYLINDERS
Abstract
This invention concerns a bulldozer blade having a blade tilt
function effected by independently functioning lift cylinders
thereby eliminating separate tilt hardware and controls.
Inventors: |
Cherney; Mark John; (Potosi,
WI) ; Bauer; Jeffrey A.; (Asbury, IA) |
Correspondence
Address: |
BAKER & DANIELS LLP
300 NORTH MERIDIAN STREET, SUITE 2700
INDIANAPOLIS
IN
46204
US
|
Assignee: |
DEERE & COMPANY
Moline
IL
|
Family ID: |
39732298 |
Appl. No.: |
11/681391 |
Filed: |
March 2, 2007 |
Current U.S.
Class: |
172/824 ;
172/812 |
Current CPC
Class: |
E02F 3/7618
20130101 |
Class at
Publication: |
172/824 ;
172/812 |
International
Class: |
E02F 3/815 20060101
E02F003/815 |
Claims
1. A dozer comprising a blade adjustable for tilt by means of
independently operable lift jacks.
2. The dozer of claim 1 where the independently operable lift jacks
comprise electro-hydraulically controlled cylinders.
3. The dozer of claim 2 where blade tilt results from differential
extension of the pistons of the lift jacks.
4. The dozer of claim 2 whereby the lift jacks are independently
controlled by a suitable algorithm programmed into a controller.
Description
FIELD OF THE INVENTION
[0001] The invention relates to push blade adjustments for a
hydraulically adjustable bulldozer blade
BACKGROUND OF THE INVENTION
[0002] Hydraulically adjustable bulldozer blades are well known in
the art having been described in such U.S. Pat. No. 2,678,508
including tilting features therefore; Pat. Nos. 2,817,168;
3,184,869; 3,991,832, 4,487,269; and 4,828,045 all incorporated
herein by reference.
SUMMARY OF THE INVENTION
[0003] The instant invention relates to hydraulically adjustable
dozer blades incorporating electro-hydraulically controlled
hydraulic cylinder movement to provide blade tilt without separate
traditional tilt function hardware and controls.
[0004] The above mentioned and other features of this invention,
and the manner of attaining them, will become more apparent and the
invention itself will be better understood by reference to the
following description of embodiments of the invention taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 presents a side view of the present invention showing
lift a cylinder connected to the blade.
[0006] FIG. 2 illustrates the blade in a lifted position parallel
to level ground.
[0007] FIG. 3. and FIG. 4 illustrates the blade in a tilt
position.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0008] The term bulldozer 10 is applied to a vehicle for pushing
material with a forward blade. Generally the vehicles are equipped
with endless belts 14 or tracks for motive power. However wheeled
vehicles equipped with forward blades 12 for pushing material also
qualify as bulldozers. The term is frequently shortened to `dozer`
and will be so identified hereafter. Dozer forward blade systems
may be broadly classified as those having support bracing located
outside of the vehicle tracks or wheels (push-beam type) and those
having support bracing between the wheels or tracks ("C"-frame
type).
[0009] Functions useful for dozer blades include the raising and
lowering of the blade hereafter referenced as "lift". Blade angle
concerns movement of one end of the blade forward, corresponding
with movement of the opposite end of the blade rearward. With the
vehicle axis defined as parallel to the forward/rearward direction
of travel, the pitch is described as movement of the top edge of
the blade generally along the vehicle forward and rearward with
respect to the lower blade edge so as to change the angle at which
the blade intersects level ground. Some blades are contoured in a
concave shape as viewed from the front of the vehicle. The
blade-ground angle of intersection in the case of curved blades in
such instance would relate to the angle created by the intersection
of a tangent to the curve of the blade with level ground. Blade
tilt involves raising, or lowering, one end of the blade relative
to the opposite end.
[0010] Push-beam type blade supports are exemplified by disclosures
such as U.S. Pat. No. 3,628,612. Disclosed is a blade support
system involving jacks directly for the raising and lowering of the
blade; the angling of the blade; and the pitch of the blade. Means
by which blade tilt may be effected is not described. The
push-beams outside the tracks are connected by a transverse
intermediate portion 14 behind the blade.
[0011] U.S. Pat. No. 3,184,869, incorporated herein by reference,
discloses a push beam support where a separate transverse structure
is not employed. Rather, the blade structure serves the function of
the intermediate portion of the transverse structure. The blade
structure is disclosed as having a pitch function but apparently
lacking an angle function.
[0012] U.S. Pat. No. 2,678,508, incorporated herein by reference,
describes tilting a blade by extending or retracting a pitch jack
on one side of the blade.
[0013] It would be advantageous to effect blade adjustment for
lift, pitch and tilt adjustments wherein the blade structure
involves fewer operating parts than disclosed by the prior art.
Lift jacks 18 applicable to the instant invention include hydraulic
cylinders of the double-acting type. Advantageously, the cylinders
employ an electronic feed-back loop to a controller that informs
the controller of the position of the piston within the cylinder
which also relates to the position of the connection of the piston
to the blade support structure, and through the structure to the
position of the blade. Such cylinders are known in the art and
commercially available.
[0014] The instant invention relates to blade support structures
which employ at least two blade lift cylinders 18a, 18b situated
with at least one lift cylinder on each side of the vehicle axis.
The blade lift system makes advantageous use of electro-hydraulic
controls for the lift cylinders. It is also contemplated that a
plurality of cylinders appropriately configured may substitute for
a single cylinder on each side of the vehicle axis.
[0015] The invention will be described as applied to dozer blades
configured with a push-beam 16 support. As known in the art a
spherical bushing connection 22 or other known connection for each
leg of the push beam at the connection of the push beam and blade
permits movement about the connection in more than one plane. The
lift cylinders 18a, 18b connect to the blade 12 also by a fitting
permitting movement about the connection 20. According to such an
arrangement, independently actuating lift cylinders 18a, 18b
attached between the blade and vehicle results in a tilted blade.
The lift cylinders are affixed to the dozer frame by a connection
24a, 24b of the well known trunion and yoke type.
[0016] A dozer equipped as described herein may effect a blade tilt
in response to a command or signal provided from the dozer operator
without the necessity of separate blade tilting apparatus by
independently extending (or retracting) one of the lift cylinders
18a, 18b, relative to the other lift cylinder 18b, 18a. The
independent movement of the lift cylinders results in raising (or
lowering) of the blade 12 on one side of the dozer axis relative to
the other side, thereby effecting a change of blade tilt. Blade
tilt may also be effected by operating lift cylinders in
raising/lowering directions opposite one another.
[0017] Additional hardware required in systems known in the art
making use of lift cylinders for blade tilt in push beam style
dozers include a means for by-pass of hydraulic fluid otherwise
directed to the lift cylinders. When raising or lowering a blade
that has been previously tilted as a result of the lift cylinders
moving independently, the raising or lowering results in the
cylinders operating in parallel. At maximum lift or maximum depth,
a one of the cylinders necessarily reaches end-of-stroke before the
other. In conventional cylinders, the hydraulic pressure is
relieved by relief valves, either at each individual cylinder, or a
by a central relief valve.
[0018] Electro-hydraulically controlled cylinders of the type
suggested for use with the instant invention provide feed-back of
the piston location to a controller. Pressure feedback is also
available to the operator. When the piston reaches end-of-stroke,
the feed-back controller may be programmed by suitable algorithm to
close the hydraulic valve to the cylinder contemporaneously with
the piston reaching the end-of-stroke position. The use of
electro-hydraulically controlled cylinders save costs, reduce
cylinder complexity, and eliminate a potential maintenance item by
deletion of the by-pass valve.
[0019] The feed-back data of the location of the piston in the
hydraulic cylinder is provided to an algorithm in a controller (not
shown). The controller limits hydraulic fluid feed to pistons at
their end-of-stroke. The controller activates pistons in parallel
for lifting the blade, and separately to engage the tilt
function.
* * * * *