Note: Descriptions are shown in the official language in which they were submitted.
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This application claims priority on US Provisional Patent Application No.
61/148,146 filed January 29, 2009, incorporated herein by reference.
VIBRATORY COMPACTION/'DRIVING APPARATUS
Technical Field
The present invention relates generally to soil compactors/drivers
and, in particular, to a soil compactor/driver with reduced manufacturing
and maintenance costs.
Background Art
Power operated soil compactors are used in the construction
industry to increase the density of soil during excavation projects. In some
known compactors, a unit for inducing vibrations in a base plate includes a
eccentrically mounted, rotatable weight. The weight is suitably rotated, i.e.,
.by a hydraulic motor to produce vibrations or oscillations in the compactor.
It is also known to operate soil compactors using the boom of a backhoe
in order to position the compactor appropriately. if a hydraulic motor is
used to drive the eccentric weight, it is also known to use the hydraulic
system.of the backhoe to provide hydraulic fluid to the hydraulic motor in
the compactor.
In at least some compactors, the weight mechanism is; supported for
rotation between a pair of bearings. Due to the extreme conditions under
which soil compactors are operated, maintenance of these support
bearings is often needed. In order to improve reliability of past soil
compactors, lubricating systems have been devised to lubricate the
bearings. In at least one prior art compactor, a means for delivering
grease to the bearings was provided, which included passages connected
with the bearing through which grease was delivered from an outside
source of grease such as a grease gun. An example of a soil compactor,
provided with a means for greasing the support bearings, is disclosed in
U.S. Patent No. 3;561,336:
In another type of soil compactor, lubrication was provided to the
bearings using an oil sump. The rotating weight would pass through the oil
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in the oil sump resulting in the bearings being splash lubricated by oil. Use
of an oil sump necessitates monitoring of the oil level in the compactor and
it also increases the cost of the unit since the weight chamber must be
sealed to prevent leakage of the oil. In both prior art designs described
above, periodic maintenance was necessary. If lubrication wasn't
maintained, the bearings would quickly fail, requiring a repair and costly
downtime for the compactor.
Disclosure of Invention
The present invention provides a new and improved soil
compactor/driver in which both manufacturing costs and maintenance
costs are reduced. According to a preferred embodiment, the
compactor/driver includes a housing in which a weight chamber is defined.
Preferably, the apparatus includes mounting structure by which the
housing is attached to a manipulating machine such as a backhoe. A
weight assembly is carried by the housing and includes an eccentrically
mounted weight which is locatable within the chamber. Rotation of the
weight produces vibrationfimpulses in the housing. When the apparatus is
used as a soil compactor, the housing is attached to a compaction plate
which transmits these vibratory forces to soil and effects its compaction.
When used as a driver, the housing transmits the impulses to a base plate
which, in turn, is used to drive in pins, posts, etc.
According to one feature of the invention, the weight assembly is
supported for rotation within the chamber by a pair of sealed bearings that
do not require maintenance. In a more preferred embodiment, the sealed
bearings are spherical bearings.
According to another feature of the invention, the weight assembly
may comprise first and second end plates, each of the end plates adapted
to receive at least a portion of one of the sealed bearings. The housing
defines first and second openings associated with the first and second end
plates. According to this feature, the end plates, bearings and weight are
arranged to be preassembled outside of the housing. After the
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components are assembled, the entire assembly is installable as a unit into
the housing which substantially reduces manufacturing costs and assembly
time while. also decreasing maintenance costs.
According to the illustrated embodiment, the housing comprises a
weldment that includes two spaced-apart vertical side plates welded to a
base plate and further includes a pair of abutting, inverted L-shaped plate
members that are welded to the side plates. Horizontal portions of the L-
shaped plates abut each other and are preferably welded together to
thereby define at least a portion of the weight chamber.
Additional features of the invention will become apparent and a
fuller understanding obtained by reading the following detailed description
made with the accompanying drawings.
Brief Description of Drawings
Fig. 1 is a an exploded view of a soil compactor/driver constructed in
accordance with a preferred embodiment of the invention;
Fig. 2 is an exploded view of a vibratory mechanism forming part of
the device shown in Fig. 1;
Fig. 3 illustrates one embodiment of a weight subassembly that
forms part of the vibratory unit shown in Fig. 2; and
Fig. 4 illustrates another embodiment of a weight subassembly that
forms part of the vibratory unit shown in Fig. 2.
Best Mode for Carrying Out the Invention
Fig. 1 is an exploded view of an compactor/d river assembly
constructed in accordance with a preferred embodiment of the invention.
The assembly includes a vibratory unit indicated generally by the reference
character 10 and a mounting frame 12 by which the vibratory unit 10 is
attached to an operating arm such as the boom of a backhoe (not shown).
As seen in Fig. 1, the mounting frame 12 includes a pair of spaced apart
inverted U-shaped side plates 14 disposed on either side of a mounting
plate 16. The mounting plate 16 is suitably attached to an operating/lifting
arm using appropriate hardware. For example, the mounting frame may be
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mounted to the boom of a backhoe using the mounting arrangement
disclosed in U.S. Patent No. 5,927,665, which is owned by the present
assignee, and which is hereby incorporated by reference.
The inverted U-shaped side plates 14 define four mounting legs 20
to which the vibratory/oscillatory unit 10 is attached. In the illustrated
embodiment, the vibratory unit is coupled to the legs 20 by four isolation
mounts 24. Details of the isolation mounts, etc., can be found in U.S.
Patent No. 3,909,149. Each isolation mount 24 is bolted to an associated
leg and, in turn, is bolted to the vibratory unit 10.
As seen best in Fig. 1 and Fig. 2, the vibratory unit 10 (Fig. 1)
includes. a rotatable, eccentrically mounted weight 28 (Fig. 2) which, when
rotated, produces vibrations/pulses in the vibration unit 10. The vibration
unit 10 includes a compaction plate 30 and a vibration inducing drive unit
34 (Fig. 2) rigidly attached to the compaction plate 30.
The vibration inducing drive unit 34 includes a housing indicated
generally by the reference character 40 and a rotatable weight assembly
68 that is mounted in the housing 40 and which is rotated by a drive motor
60 shown in Fig. 1. The housing 40, which is preferably a weidment,
includes first and second spaced apart vertical side plates 42, 44. The
side plates 42, 44, in the, illustrated embodiment, have their bottom edges
welded to the top of a base plate 45. A pair of inverted L-shaped plates
47, each having a horizontal segment 47a and a vertical segment 47b
(only one is shown), define a substantially sealed chamber 43 in which the
weight assembly 68 is located. In particular, the side edges of the vertical
segment 47b of each plate 47 is welded to the inside of the side plates 42,
44. A bottom edge (as viewed in Fig. 2) of each L-shaped plate 47 is
welded to the base plate. The horizontal segments 47a of the L-shaped
plates 47 abut each other and are welded along the boundary indicated by
the reference character 47c. Mounting plates 48 are welded to the side
plates 42, 44 and serve as mounting points for some applications.
In the illustrated embodiment, the drive motor 60 is a hydraulic
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motor and includes hydraulic hoses 62 for receiving and discharging
hydraulic fluid. The hoses 62 extend between the hydraulic motor 60 and
a control valve 64. If the compactor/driver is attached to a backhoe, the
control valve 64 is suitably connected to the hydraulic system forming part
of the backhoe.
As seen best in Fig. 1, each isolation mount 24 includes a mounting
plate 24a that is secured to the side plates 42, 44 of the vibratory unit
housing 40. Each mount includes a second mounting plate 24b which is
secured to an associated leg 20 of the mounting frame 12. Fig. 1
illustrates bolt holes 20a for receiving bolts from the isolation mounts.
As indicated above, the eccentrically mounted weight 28, when
rotated by the hydraulic motor 60, induces vibration/impulses which are
coupled to the base plate 45. If the device is used as a compactor, the
boom would position the compactor on the earth to be compacted.
Rotating the concentrically mounted weight 60 produces vibrations which,
when transmitted to the soil produces compaction in the soil. A fuller
understanding of this type of soil compactor can be found in-U.S. Patent
No. 3,561,336, which is hereby incorporated by reference.
According to the invention, the vibration mechanism 68, as seen in
Fig. 2, includes a support shaft 70 defining an axis of rotation for the
weight
28. The weight 28 is supported for rotation between first and second
bearing housings 74, 76 by a pair of associated bearings 78. According to
theinvention, the bearings are preferably sealed spherical roller bearings
which require no maintenance. However, other types of sealed bearings
are also contemplated by the present invention. As seen in Fig. 3, the first
and second bearing housings 74, 76 are secured to the first and second
side plates 42, 44.
According to the preferred embodiment of the invention, the
vibration mechanism 68, including the eccentrically mounted weight 28, is
preassembled as a subassembly and is then installed into the housing 40.
As seen best in Fig. 3, the weight mechanism subassembly includes the
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weight 28, the first and second bearing housings 74, 76, the sealed
support bearings 78 and the shaft 70 that is received and supported by the
sealed bearings 78.
In the embodiment illustrated in Fig. 3, the first side plate 42
includes a relatively large opening for receiving a reduced diameter portion
(or pilot diameter) 74a of the first bearing housing 74. The second side
plate 44 includes an inside circular recess 44a for receiving a pilot diameter
78a of the second bearing housing 76. Suitable fasteners, such as bolts,
secure the second bearing housing 76 to the second side plate 44.
The shaft 70 that is rotatably supported by the sealed bearings 78
includes a splined inner bore 70a which is adapted to receive a
complementally shaped splined drive shaft (not shown) forming a part of
the hydraulic drive motor 60. The splined connection allows the hydraulic
drive motor 60 to be easily coupled and de-coupled from the eccentric
weight mechanism 68, for maintenance and other purposes.
With the disclosed construction, the manufacture and maintenance
of this unit is greatly enhanced. The eccentric weight mechanism 68,
including the first and second bearing housings 74, 76 and sealed bearings
78 is pre-assembled as a unit and the entire unit is then installed into the
weight housing 40. Bolts 75 are then used to secure the first bearing
housing 74 to the first side plate 42 and the second bearing housing 76 to
the second side plate 44. If maintenance is needed, the bolts 75 are
simply removed and the entire weight mechanism 68 is removed as a unit.
The use of sealed bearings eliminates the need for periodic maintenance
to grease the bearings or to provide an oil sump in the weight housing 40
for lubricating the bearings. Spherical bearings suitable for this application
are available from SKF and are sold under the "Explorer" designation.
With the disclosed construction, both manufacturing costs and
maintenance costs are reduced while increasing reliability.
Fig. 4 illustrates an alternate construction for the weight mechanism.
In this construction, a weight 28' is comprised of three separate weight
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elements 84 that are pressed on or otherwise suitably attached to a
support shaft. Sealed bearings 78 of the type disclosed in Fig. 3 rotatably
support the weight 28' between associated bearing caps 74, 76'. A first
bearing cap 74' includes a reduced diameter portion 74a' which is received
by the first side plate 42. Unlike the second bearing housing 44 shown in
Fig. 3, the second bearing housing 44' shown in Fig. 4 is of a stepped
construction and includes a reduced diameter portion 76a' that is received
in a bore 44a' formed in the second side plate 44'. Suitable fasteners,
such as bolts, secure the first and second bearing housings 74', 76' to the
associated side plates 42, 44'. In the alternate construction, the weight
mechanism is also preassembled outside the housing and is installed as a
subassembly into the housing. Like the first embodiment, manufacturing
and maintenance costs are reduced by the illustrated construction. The
use of sealed bearings, preferably spherical sealed bearings, substantially
reduces maintenance and the bearings themselves can be easily replaced
once the weight subassembly is removed from the vibratory housing.
The disclosed compactor/driver device can be used, not only to
compact soil, but can also be used to drive wood, steel and aluminum
sheeting, beams, pilings, posts and sea walls. The disclosed unit can
deliver impulses at the rate of 2100 cycles per minute by suitable operation
of the hydraulic motor 60.
Although the invention has been described with a certain degree of
particularity, it should be understood that those skilled in the art can make
various changes to it without departing from the spirit or scope of the
invention as hereinafter claimed.
