Note: Descriptions are shown in the official language in which they were submitted.
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- 1 - 68297-894
This invention relates to a method and apparatus for
breaking composite material such as cement into a plurality of
pieces.
Numerous types of apparatus have been devised for break-
ing surfaces such as concrete or asphalt pavement. Such apparatus
may be referred to as demolition apparatus.
Known demolition apparatus are shown in United States
Patents 3,319,724 and 3,358,779. These known demolition apparatus
are attached to a boom o an earthmoving machine for support of
the apparatus. These known apparatus require a separate motor for
operation thereof.
It is an object of this invention to provide demolition
apparatus which is adapted to be attached to a boom of an earth-
moving machine, but in which the demolition apparatus is operated
by movement of the boom, without the use of a separate motor for
operation of the dernolition apparatus.
SUMI~qARY OF THE INVENTION
The invention provides apparatus adapted to mounting on
a boom arm supported for movement by fluid actuating means, said
apparatus comprising a support member, means for connecting the
support member to the boom arm, an elongate impact plunger suppor-
ted by the support member for linear movement relative to the
support member and for engaging a surface to be impacted, a spring
disposed for biasing the plunger toward the surface, means for
preloading the spring in response to movement of the support member
by the boom arm toward the surface to develop a substantial
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68297-894
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preload force within the spring, means for releasing the spring
when the support member moves toward the surface to a predetermined
limit, and means for exerting the preload force of the spring
against the impact plunger when the spring is released.
The invention also provides a demolition apparatus adap-
ted to be connected to a force arm and moved into forcible engage-
ment with a composite material for breaking said composite material
into a plurality of pieces, comprising: a housing having an end
and being connectable to and movable in response to movement of
said force arm; an actuator plunger having an end and being con-
nected to and axially movable relative to the housing between
first and second positions; a power plunger having an end and being
connected to and axially movable relative to the housing in a
direction substantially parallel to said actuator plunger in
response to movement of said actuator plunger from the first toward
the second position, said plunger ends being longitudinally spaced
a preselected distance "D" one from the other at the first position
of the actuator plunger with said actuator plunger end being
spaced the farthest from said housing; spring means ~or longi-
tudinally biasing the power plunger relative to the housing and in
a direction toward said end of said power plunger; and means for
compressing said spring means in response to moving the actuator
plunger from the first toward the second position and releasing
said spring means in response to the power plunger having been
moved relative to and toward the housing a preselected distance
greater than said preselected distance.
- 2a - 68297-894
The disclosed demolition apparatus is capable of apply-
ing large forces in consideration of the physical size and weight
of the apparatus.
It can be easily and readily attached to a boom of an
earthmoving machine and detached therefrom, and can be operated
at any desired angle, such as vertical operation for demolition
of a pavement and such as horizontal operation for demolition of
a wall or the like. The demolition apparatus can be constructed
at relatively low rosts and is long lived.
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In operation, the housing is moved toward a
pavement or wall or the like which is to be
demolished. As the housing is moved toward the
pavement, the actuator plunger comes into engagement
with the surface to be demolished. However, the power
plunger is spaced from the surface. As continued
movement of the housing toward the pavement surface
occurs, the actuator plunger remains in engagement with
the pavement, and the latch which is attached to the
actuator plunger remains in engagement with the power
; plunger and maintains the position of the power plunger
with respect to the surface. Therefore, continued
movement of the housing toward the surface causes the
actuator plunger and the power plunger to be positioned
upwardly within the housing. Such relative movement
between the power plunger and the housing is against
the forces of the power spring.
This movement of the housing toward the
surface continues until an abutment member comes into
engagement with the latch which is attached to the
actuator plunger. As the latch comes into engagement
with the abutment member, the latch is operated and is
~; released from engagement with the power plunger. ~hen
this occurs, the power spring instantaneously and
rapidly forces the power plunger to travel into
striking engagement with the pavement. The power
plunger strikes the pavement with the energy of the
power spring.
In another aspect of the invention, a holding
pressure is exerted on the first surface of the
material in a direction generally toward the second
surface of the composite material. The holding
pressure is increased to generate tensile forces within
the first thickness portion and along the surface of a
slab of material to be broken. This increased
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magnitude holding pressure is maintained on the
material while the first surface is impacted in a
direction generally toward the second surface at a
location spaced from the location of said holding
pressure.
Brief Description of the Drawings
Fig. 1 is a side elevational view of a boom
and boom arm of an earthmoving machine, showing a
bucket attached to the boom arm for movement and
operation with movement of the boom and the boom arm.
Fig. 2 is a side elevational view showing the
demolition apparatus attached to the boom arm,
replacing the bucket. The demolition apparatus is
shown supported by the boom arm in a position spaced
from a pavement to be demolished. In this figure the
pavement is shown in section.
Fig. 3 is a side elevational view showing the
boom and the boom arm of Figs. 1 and 2. This figure
shows the actuator plunger of the demolition apparatus
in engagement with a pavement surface.
Fig. 4 is a side elevational view showing a
portion of the boom arm of the machine, with the
demolition apparatus attached thereto and showing the
positions of the power plunger and actuator plunger at
the instant of release of the power plunger for
striking action.
Fig. 5 is a side elevational view, similar to
Fig. 4, but illustrating downward striking action of
the power plunger.
Fig. 6 is a fragmentary sectional view
illustrating demolition action created by successive
operations of the power plunger of the demolition
apparatus.
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Fig. 7 is an enlarged side sectional view
illustrating the position of the plungers of the
demolition apparatus as shown in Figs, 2 and 3, as the
demolition apparatus is being moved downwardly toward a
surface for demolition thereof.
Fig. 8 is an enlarged sectional view similar
to Fig~ 7 but showing the position of the plungers
during ~urther downward movement of the housing and as
the actuator plunger engages a surface to be demolished.
Fig~ 9 is a fragmentary sectional view drawn
on substantially the same scale as Figs. 7 and 8, and
illustrating the positions of the elements and Members
of the demolition apparatus at the instant the power
plunger is released for downward striking travel toward
a surface for demolition thereof.
Fig. 10 is a sectional view similar to Figs. 7
and 8 and illustrating striking action of the power
plunger after release thereof.
Best Mode for Carrvina Out the Invention
, . _
Figs. 1, 2, and 3 show a portion of a machine
operation unit 20 which may be a tractor or carrier
vehicle or the like, herein shown as an earthmoving
machine.
Pivotally attached to the operation unit 20 is
a boom 22. Pivotally attached to the boom 22 by means
of a connection unit 24 is a boom or force arm 26.
Rigidly attached to the boom 22 intermediate
the ends thereof is a connection unit 30. A linearly
operable fluid motor 34 is pivotally attached to the
operation unit 20 and to the connection unit 30. A
linearly operable fluid motor 36 is pivotally attached
to the connection unit 30 and has a piston rod 38
extending therefrom. The piston rod 38 is pivoitally
attached to the connection unit 24.
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A linearly operable fluid motor 40 is
pivotally attached to the connection unit 24 and has a
piston rod 44 extending there~rom. A lever 46 is
pivotally attached to the end of the piston rod 44.
The lever 46 is also pivotally attached to the arm 26
adjacent the end thereof.
As shown in Fig. 1, the boom arm 26 has a
bucket 50 pivotally attached thereto adjacent the end
thereof for movement and operation by the operation
unit 20. The bucket 50 is also pivotally attached to a
link 52. The link 52 is also pivotally attached to the
: lever 46. The fluid motors 34, 36, and 40 are operated
by control means, not shown, carried by the operation
unit 20. Thus, the boom 22, the boom arm 26, and the
bucket 50 are moved by operation of the operation unit
n.
When it is desired to attach demolition
apparatus 60 of this invention to the boom arm 26, the
:~ bucket 50 is removed from the arm 26 and fro~ the link
52. The demolition apparatus 60 of this invention
; includes a housing 64 which is provided with a bracket
62 which is pivotally attached to the end portion of
~: the force arm 26 and to the link 52.
Within the housing 64 is a power plunger 68
- 25 which has an end 69. The power plunger 68 is mounted
at the opposite ends o~ the housing 64 and extends from
both of the opposite ends of the housing 64. The power
plunger 68 is axially movable with respect to the
housing 64.
As shown in Figs. 7, 8, and 10, within the
housing 64 at the lower end thereof is a cushion 70.
The power plunger 68 extends through the cushion 70.
Encompassing the power plunger 68 and firmly secured
thereto is a collar 72. Compressed between the collar
72 and the upper end o~ the housing 64 and encompassing
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the power plunger 68 is a resilient or biasing member
preferably in the form of a coil spring 76, for
longitudinally biasing the power plunger 68 relative to
the housing 64 and in a direction toward said end 69 of
the power plunger 68.
Also, mounted within the housing 64 is an
actuator plunger 80 which has an end 81. The actuator
plunger 80 extends from both ends of the housing 64 and
extends through the cushion 70. The actuator plunger
80 is axially movable with respect to the housing 64
~ between a first position (Fig. 7) and a second position
- (Figs. 8 & 9). Firmly secured to the actuator plunger
80 intermediate the ends thereof is a base 82. A lug
84 is secured to the base 82. Pivotally attached to
the lug 84 and to the actuator plunger 80 is a latch
86. The latch 86 has an engagement portion 86e which
is positioned adjacent the power plunger 68. A control
spring 89 is compressed between the base 82 and the
latch 86 and urges pivotal movement of the latch 86 in
a counterclockwise direction as viewed in Figs. 7-lO.
The lug 84 is provided with a stop portion 84e which
limits counterclockwise pivotal movement of the latch
86 to the position thereof shown in Figs. 7 and 8.
` Fixed within the housing 64, adjacent the actuator
plunger 80, is an abutment member 90 which is
engageable by the latch 86.
For purposes of clarity, it should be
understood that the spring means 77 for longitudinally
biasing the power plunger 68 relative to the housing 64
and in a direction toward said end 69 of said power
plunger 68 includes the spring 76, collar 72. Further,
the means 83 for compressing said spring means 77 in
response to moving the actuator plunger 80 from the
first toward the second position and releasing said
spring means 77 in response to the power plunger 68
.
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having been moved toward the housing 64 a distance
greater than said preselected distance (D) includes
base 82, lug 84, lug portion 84e, latch 86, latch
engagement porton 86e, coil spring 89, lug stop portion
84e/ and abutment member 90. It should also be
understood that the "trigger" mechanism, which consists
of the latch 86, collar 72, and abutment member 90, can
be of other construction without departing from this
invention.
Industrial Applicability
As stated above and as shown, the demolition
apparatus 60 of this invention easily and readily
replaces the bucket 50 which is shown attached to the
boom arm 26. The bracket 62 of the housing 64 is
pivotally attached to the end portion of the boom arm
26 and to the link 52. Movement of the boom 22 and the
boom arm 26 thus moves the demolition apparatus.
In a demolition process using the demolition
apparatus 60, the boom 22 and the boom arm 26 are
; operated to move the demolition apparatus 60 toward thesurface to be demolished, as illustrated in Fig. 2.
The actuator plunger 80 and the power plunger 68 are
normally in their maximum extension positions, as shown
in Figs. 2, 3, and 7. In this position, the power
plunger 68 is spaced upwardly with respect to the
actuator plunger 80. As the boom 22 and the arm 26
; move the demolition apparatus 60 downwardly toward a
pavement 96, the actuator plunger 80 is brought into
engagement with the pavement 96, as illustrated in Fig.
3. The engagement portion 86e of the latch 86 which is
attached to the actuator plunger 86 is in engagement
with the collar 72, which is secured to the power
plunger 68. Therefore, as the boom 22 and the arm 26
continue to move the demolition apparatus 60
downwardly, the housing 64 is moved downward but the
actuator plunger 80 and the power plunger 68 do not
move. Therefore, there is relative movement between
the plungers 80 and 68 and the housing 64. This
downward movement of the housing 64 is against the
compression forces of the spring 76 which encircles the
power plunger 68 and which engages the collar 72 and
the housing 64. This downward movement of the housing
64 continues until the abutment member 90 within the
housing 64 engages the latch 86 which is carried by the
actuator plunger 80, as shown in Fig. 9. This is at a
location at which the power plunger 68 has been moved
toward and relative to the housing 64 a distance
greater than preselected distance ~Dn. When this
engagement occurs, the latch 86 is pivotally moved
against the force of the control spring 89 and becomes
disengaged from the collar 72 which is secured to the
power plunger 68, as illustrated in Fig. 9. When the
latch 86 releases the collar 72, the power spring 76
immediately forces the power plunger 68 downwardly at a
high rate and with a significant force, as illustrated
in Figs. 9 and 10. The power plunger 68 strikes the
pavement 96 and crushes and breaks the pavement 96, as
illustrated in Figs. 5 and 6. When the power plunger
68 reaches its maximum downward position as illustrated
in Fig. 10, the collar 72 engages the cushion 70.
The demolition apparatus 60 is then again
raised by the arm 26 and the boom 22, and the
demolition apparatus 60 is moved to an adjacent
position above the pavement 96. The housing 64 is
again moved downwardly for engagement of the actuator
plunger 80 with the pavement 96, and the operation is
repeated to cause the power plunger 68 to strike the
pave~ent in ~everal adjacent locations. The pavement
is broken and demolished, as illustrated in Fig. 6.
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Thus, the demolition apparatus of this
invention is operated without the use of a special
motor for operation thereof. Movement of the boom arm
26 and the boom 22 with respect to the sur~ace to be
demolished causes operation of the demolition apparatus
60.
If it is desired to demolish a wall, ceiling,
- or the like, the boom 22 and the boom arm 26 are
operated to change the angle of the housing 64.
Thus, the demolition apparatus 60 can be
employed to demolish a surface which is substantially
horizontal or a surface which is substantially vertical
or a surface having any other angle. However, at some
angles it is necessary to employ a return spring on the
actuator plunger 80 for ease of operation.
Another apsect of the invention resides in the
method of breaking into a plurality of pieces a sheet
of pavement or composite material 96 having (as shown
in Figs. 4 and 5) opposed first and second surfaces
20 102,103, a thickness, a first thickness portion 104
containing said first surface 102, and a second
thickness portion 106 containing said second surface
103 and wherein said composite material 96 has greater
strength in compression than in tension. An example of
such composite material 96 is concrete containing
Portland cement.
In the steps of this unique method, a holding
pressure is exerted on the first surface of the
composite material 96 in a direction generally to~ard
the second surface 103. The holding pressure is then
increased to a magnitude sufficient to generate tensile
forces within said first thickness portion 104 and
along said first surface 102. Thereafter, the
increased magnitude holding pressure is maintained
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while impacting the first surface 102 in a direction
generally toward said second surface and at a location
~ spaced from the location of said holding pressure.
; As described above, the holding or concrete
bending pressure is exerted by actuato~ plunger 80 and
the impacting force is exerted by power plunger 68.
One skilled in the art will quickly recognize
that by exerting the increased holding pressure on the
first surface of the concrete, the upper portion of the
concrete will be subjected to tensile forces and the
lower portlon will be subjected to compression forces
in response to generating bending forces on the
concrete.
It has been discovered that when concrete has
such forces imparted and then heavily impacted in the
general vicinity of such bending forces, that the
concrete will shatter and break into a significantly
larger number of pieces to a significantly greater
depth and the broken pieces will be of smaller
individual sizes than where the composite material is
impacted without exerting bending forces upon it. By
the method of this invention, the inherent
characteristics of concrete and other composite
material, both man made and naturally occurring, are
utilized to mechanically assist i~ the demclition
process. It has also been observed that upon impact,
major breaking lines radially downwardly and outwardly
at approximately 45 angles, as shown in Fig. 5, as
opposed to more conventional, substantially vertical,
cracking that is produced by impacting the unstressed
concrete.
~ he increased magnitude holding or bending
pressures exerted on the concrete are naturally a
function of the thickness of the concrete desired to be
broken. The majority of concrete generally desired to
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be removed falls within a thickness of 12 inches or
less. Preferred increased magnitude holding pressures
are therefore in the range of about 600 p9i to about
150 psi. This pressure is preferably exerted by a
holding element or actuator plunger 80 having an end
whose area is greater than about 7 square inches. At
pressures below the preferred minimum, the upper
surface of the concrete is not sufficiently stressed
and breaking is undersirably inefficient and wastes
manpower and expenseO At pressures greater than the
preferred maximum, the concrete is unnecessarily
stressed which represents an undesirable waste of
manpower and expense. Where the holding element has a
surface area less than the preferred range, the
concrete first surface is subjected to undesirable
shear forces and where the surface is greater than that
preferred area, the apparatus wastes material utilized
for its construction and requires unnecessary power to
move and handle the apparatus.
In breaking concrete, it has also been
discovered that the distance between the holding force
and the impact force should be greater than one inch
and the concrete should be impacted at intervals not
less than 5 inches from one another in order to brealc
the concrete efficiently and effectively. At lesser
distances apart an undesirable shearing action is
produced and at less distances between impacts there is
a waste of resources by over fracturing the concrete
and/or failins to efficiently utilize the optimum
lateral extent of concrete crack propogation.
Although the preferred embodiment of the boom
operated demolition apparatus of this invention has
been described, it will be understood that within the
purview of this invention various changes may be made
in the form, details, proportion and arrangement of
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parts, the combination thereof, and the mode of
operation, which generally stated consist in a boom
operated demolition apparatus within the scope of the
appended claims.
