Information
-
Patent Grant
-
6520592
-
Patent Number
6,520,592
-
Date Filed
Monday, May 7, 200123 years ago
-
Date Issued
Tuesday, February 18, 200321 years ago
-
Inventors
-
-
Examiners
- Bagnell; David
- Singh; Sunil
Agents
- Andrus, Sceales, Starke & Sawall, LLP
-
CPC
-
US Classifications
Field of Search
US
- 299 69
- 299 361
- 299 381
- 299 100
- 404 83
- 404 85
- 404 86
- 404 90
- 404 1332
- 037 403
- 414 912
- 172 245
- 172 247
- 172 253
- 173 100
- 173 94
- 173 89
- 173 211
-
International Classifications
-
Abstract
A pavement demolition hammer is removably fastened to a loader and includes a mounting plate securable to the loader. A framework is attached to the mounting plate and is provided with a lower spring and an upper spring spaced from the lower spring. A hammer handle has a proximal end pivotally mounted to the framework for swinging movement between the lower spring and the upper spring, and a distal end equipped with a hammer head adapted to engage the pavement. The loader applies a moving force to the mounting plate such that the lower spring is accelerated against the bottom of the handle causing the handle and the hammer head to swing upwardly from a pavement surface to be broken towards the upper spring. The handle and the hammer head return to the pavement surface either by gravity or acceleration from the upper spring against the top of the handle in a manner that the hammer head impacts and demolishes the pavement surface.
Description
FIELD OF THE INVENTION
This invention relates broadly to equipment and processes for breaking up concrete, asphalt and other pavement surfaces and, more particularly, pertains to a drop hammer arrangement which is conveniently attached for movement on a loader machine such as a skid steer.
BACKGROUND OF THE INVENTION
Pavement surfaces comprised of concrete, asphalt and the like occasionally need to be partially or completely removed with the aid of various construction equipment. One type of impact device in widespread use for breaking up and demolishing smaller areas of pavement surfaces is a pneumatic, manually-operated, jack hammer. For larger expanses of pavement to be broken, it is common to equip a loader, such as a backhoe or skid steer, with an impact hammer attachment. In each case, it is necessary to supply an air compressor or separate power source to operate the jack hammer or impact hammer. In addition, there is a significant amount of vibration and fatigue inflicted on the hammer operator and the environment is affected by the large volume of dust particles emanated into the air. Other problems associated with the use of conventional hammers include a high noise factor and the periodic need to fix leaking oil fittings or repair air hose ruptures.
Other types of dedicated demolition equipment are available for breaking up concrete and other hard pavement surfaces. However, such special purpose devices are expensive to acquire, operate and maintain, and are often not practical for contractors during occasional demolition work.
Several other loader-mounted, demolition apparatus are known which use swinging hammer heads and employ various spring arrangements to impart whipping action or provide a cushioning effect. These apparatus have been generally over-complicated, require significant movement of their loader device for operation, transmit vibration and shock to the human operator and are not always easily mounted on their loaders.
Accordingly, it is desirable to provide a demolition hammer which has a simplified structure and a cost which is affordable to small sized contractors. Such demolition hammer should be capable of easy attachment to any skid steer loader and of establishing a resonant vibration such that cracking of pavement occurs throughout a large area. In addition, the demolition hammer should employ a spring arrangement which not only has the ability to return a hammer with gravity motion to an impact point and increase the speed of the return, but also relies upon the springs to absorb shocks and vibrations so they are not felt by the operator.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide an apparatus and method for demolishing pavement wherein a lower spring is utilized to accelerate a hammer handle and hammer head towards an upper spring, the hammer handle and the hammer head returning to an impact point on a pavement surface either by gravity or acceleration from the upper spring.
It is another object of the present invention to provide an apparatus and method for demolishing pavement wherein the apparatus may be quickly and universally mounted upon a skid steer loader without any electric, hydraulic or pneumatic connections.
It is also an object of the present invention to provide an apparatus and method for demolishing pavement which has a low noise factor and is operator friendly causing no fatigue on the human operator.
It is an additional object of the present invention to provide an apparatus and method for demolishing pavement which can deliver variable impacts at distances remote from the skid steer loader.
It is a further object of the present invention to provide an apparatus and method for demolishing pavement which is less expensive and less complicated than those of the prior art.
In one aspect of the invention, a pavement demolition hammer is removably fastened to a loader. A mounting plate is securable to the loader, and a framework is attached to the mounting plate and provided with a lower spring and an upper spring spaced from the lower spring. A hammer handle has a proximal end pivotally mounted to the framework for swinging movement between the lower spring and the upper spring, and a distal end is equipped with a hammer head adapted to engage the pavement. The loader applies a moving force to the mounting plate such that the lower spring is accelerated against the bottom of the handle causing the handle and the hammer head to swing upwardly from a pavement surface to be broken towards the upper spring, the handle and the hammer head returning to the pavement surface either by gravity or acceleration from the upper spring against the top of the handle in a manner that the hammer head impacts and demolishes the pavement surface. The mounting plate is a generally rectangular, planar surface having a V-shaped bracket at its upper end, and a rearwardly extending lip with a pair of spaced apertures at a lower end, the bracket and the lip being manually engagable with an adapter plate on the loader. The framework includes a horizontally extending fork bottom disposed perpendicularly and forwardly of the mounting plate, a vertically extending fork top rising from a rearward end of the fork bottom along a forward surface of the mounting plate, and an upwardly and forwardly extending fork extension connected to an upper end of the fork top. A forward end of the fork bottom carries a generally cylindrical, lower coil spring, and a forward end of the fork extension carries a generally cylindrical, upper coil spring. The framework further includes a pair of parallel, spaced apart side plates, each side plate being attached to the fork bottom, fork top and fork extension. The hammer handle is disposed to swing between the side plates. The hammer handle is provided with an upper spring plate engagable with the upper spring, and a lower spring plate engagable with the lower spring. The hammer handle is normally supported on the lower spring. The hammer head has a generally cylindrical configuration with a downwardly depending impact point. The hammer head extends beyond the forward end of the fork bottom.
In another aspect of the invention, a pavement demolishing hammer includes a loader having lifting arm structure, a hydraulic cylinder carried on the lifting structure and an adapter plate including a top end pivotally mounted to the hydraulic cylinder and a bottom end pivotally secured to the lifting arm structure, the bottom end provided with a spring loaded pin. A framework includes a mounting plate with a bracket at an upper end and an apertured lip at a lower end. The mounting plate bracket is engagable with the top end of the adapter plate and the spring loaded pin is engagable with the apertured lip. The framework further includes a horizontally extending fork bottom disposed generally perpendicularly to the mounting plate, a vertically extending fork top to which the mounting plate is secured, and an upwardly and forwardly extending fork extension connected to the fork top. A generally cylindrical, lower coil spring is disposed on the fork bottom and a generally cylindrical, upper coil spring is located on the fork extension. A pair of spaced apart, side plates is provided, each being attached to the fork bottom, fork top and the fork extension. A hammer handle has a rearward end pivotally attached to the fork top for pivotal movement between the side plates and between the upper spring and the lower spring, and a forward end provided with a hammer head adapted to engage the pavement. Selective actuation of the hydraulic cylinder moves the mounting plate and framework such that the lower spring is accelerated against the bottom of the handle causing the handle and hammer head to swing upwardly from the pavement towards the upper spring. The handle and the hammer head return to the pavement either by gravity or acceleration from the upper spring against the top of the handle in a manner that the hammer head impacts the pavement.
In yet another aspect of the invention, there is contemplated a method of demolishing pavement including the steps of a) providing a framework with a lower spring and an upper spring spaced from the lower spring; b) providing a hammer handle having a proximal end pivotally mounted to the framework between the lower spring and the upper spring, and a distal end equipped with a hammer head adapted to engage the pavement; and c) moving the framework such that the lower spring is accelerated against a bottom of the handle causing the handle and the hammer head to swing upwardly from a pavement surface towards the upper spring, the handle and the hammer head returning to the pavement surface either by gravity or acceleration from the upper spring against a top of the handle in a manner such that the hammer head impacts and demolishes the pavement surface.
Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The drawings illustrate the best mode presently contemplated of carrying out the invention.
In the drawings:
FIG. 1
is a perspective view of a pavement demolition hammer embodying the present invention;
FIG. 2A
is a side view of the demolition hammer about to be coupled to the front end of a skid steer loader;
FIG. 2B
is a view like
FIG. 2A
showing the initial engagement of the demolition hammer with the skid steer loader;
FIG. 2C
is a view like
FIG. 2B
showing the demolition hammer attached to the skid steer loader and raised from the ground;
FIG. 3A
is an enlarged, detail view showing the full engagement of a mounting plate of the demolition hammer with an adapter plate on the skid steer loader;
FIG. 3B
is an enlarged, detail view showing the initial engagement between the mounting plate of the demolition hammer and the adapter plate of the skid steer loader; and
FIGS. 4A through 4C
are side views showing the progressive manner in which the demolition hammer is used when coupled on the skid steer loader.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings,
FIG. 1
illustrates a demolition hammer
10
which is particularly useful in breaking up and demolishing hard pavement such as concrete, asphalt and the like. In the ensuing figures, it should be appreciated that the hammer
10
is designed to be conveniently and quickly coupled to any type of skid steer loader
12
which provides the moving force to make the hammer
10
operational.
In
FIG. 1
, the hammer
10
is shown as a stand alone attachment which is supported on a ground surface and fabricated so that it will maintain an upright position and not tip over. Hammer
10
has a simple yet efficient and sturdy construction generally comprised of a mounting plate
14
, a framework
16
and a hammer handle
18
having a hammer head
20
for impacting and cracking a pavement surface.
Mounting plate
14
has a generally rectangular planar surface having an upper end provided with a downwardly opening, V-shaped bracket
22
and a lower end equipped with a rearwardly extending lip
24
with a pair of spaced apart apertures, one being seen at
26
. As will be understood below, the bracket
22
and lip
24
are engagable with mating structure on an adapter plate
28
on the skid steer loader
12
.
The framework
16
is welded or otherwise fixedly joined to the forward surface of the mounting plate
14
and has a width which is less than that of the mounting plate
14
. The framework
16
includes a horizontally extending, plate like, fork bottom
30
projecting perpendicularly relative to the mounting plate
14
, a vertically extending, plate like fork top
32
rising from the rearward end of the fork bottom
30
along the height of the mounting plate
14
, and an upwardly and forwardly extending, plate like, fork extension
34
connected to the top end of the fork top
32
. In the preferred embodiment, the fork extension
34
lies at an obtuse angle of about 125 degrees relative to the fork top
32
. The forward end of the fork bottom
30
is provided with a generally cylindrical, lower spring coil
36
, while the forward end of the fork extension
34
carries a generally cylindrical, upper coil spring
38
. A pair of spaced apart, solid side plates
40
,
42
are each connected to respective side edges of the fork bottom
30
, fork top
32
and fork extension
34
. Each side plate
40
,
42
is constructed with a horizontal inline, tubular bushing
44
,
46
projecting laterally therefrom. Each bushing
44
,
46
is connected by a gusset
48
,
50
to the fork top
32
.
The hammer handle
18
is generally an elongated, square tube having a rearward end which carries a central pivot bushing
52
interposed between the inline bushings
44
,
46
projecting through the side plates
40
,
42
. A pivot pin
54
is placed through aligned openings on the inline bushings
44
,
46
and pivot bushing
52
to define a pivotal mounting for the handle
18
. A mid portion of the handle
18
has an upper spring plate
56
which is disposed on the top of the handle
18
, and a lower spring plate
58
which is located on the bottom of the handle
18
. The upper spring plate
56
is engagable with the upper spring
38
, and the lower spring plate
58
is engagable with the lower spring
36
. A forward end of the handle
18
carries the hammer head
20
which is a steel cylinder having a downwardly depending impact point
60
. The hammer head
20
is supplementally attached to the handle
18
by gusset structure
62
. In its normal rest position, the handle
18
is supported upon the lower coil spring
36
. With this construction, the handle
18
is swingable upwardly and downwardly between the side plates
40
,
42
, and between the lower coil spring
36
and the upper coil spring
38
.
As seen in
FIGS. 2A through 2C
,
3
A,
3
B, and
4
A through
4
C, the hammer
10
described above is designed to be removably attached to skid steer loader
12
by means of the mounting plate
14
and the mating adapter plate
28
. With particular reference to
FIGS. 2A
,
3
A and
3
B, the adapter plate
28
is a generally rectangular planar surface which is generally coextensive in surface area with the mounting plate
14
. The lower end of the adapter plate
28
is pivotally connected to downwardly extending arms
64
of the skid steer loader
14
. The lower end of the adapter plate
28
is also provided with a conventional, spring loaded pin arrangement
66
. This arrangement includes an elongated movable pin
68
on each side of the adapter plate
28
which passes through aligned apertures
70
in a keeper
72
on each side and through an aperture
74
formed on opposing sides in a forwardly extending ledge
76
. Each pin
68
is normally biased upwardly (as shown by the arrow in
FIG. 3B
) by a coil spring
78
which is positioned between the top of the keeper
72
and a collar
80
surrounding the pin
68
. Each pin
68
may be forced downwardly against the bias of the spring
78
to engage with the apertured lip
24
on the mounting plate
14
. The bottom of each pin
68
is provided with cam or detent structure to hold the pin in place when the pin is moved downwardly against its spring
78
. The upper end of the adapter plate
28
is pivotally secured to a rod end
82
of a hydraulic tilt cylinder
84
normally used to move the bucket (not shown) of the skid steer loader
14
. The bucket is normally detachably coupled to the skid steer loader
14
by means of the adapter plate
28
. A casing end of the cylinder
84
is pivotally connected to an extension
86
on the arms
64
. The upper end of the adapter plate
28
is also formed with an upstanding surface
88
which is engagable with the mounting plate bracket
22
.
When it is desired to use the hammer
10
, the skid steer loader
14
approaches the ground-based, stationary hammer
10
from the rear of the mounting plate
14
(FIG.
2
A). Using the tilt cylinder
84
, the skid steer operator moves the upper end of the adapter plate
28
into engagement with the mounting plate bracket
22
(
FIG. 2B
,
3
B). Further movement of the cylinder
84
pivots the adapter plate
28
into the engagement position of
FIG. 3A
at which point a worker employs the pin arrangement
66
to couple the mounting plate
14
and the hammer
10
to the adapter plate
28
and loader
14
. Thereafter, the attached hammer
10
can be raised via the loader arms
64
and moved to a desired location where pavement is to be demolished (FIG.
2
C).
To begin pavement destruction, the loader arms
64
are lowered to bring the hammer
10
to the pavement surface (FIG.
4
A). Here, the loader operator tilts the mounting plate
14
downward to a position allowing the impact point
60
of the hammer head
20
to contact the pavement surface. With a quick movement of the cylinder control, tilting the mounting plate
14
upward, the lower coil spring
36
is accelerated against the bottom of hammer handle
18
. The resulting contact applies a force causing the handle
18
to swing upward. The amount of tilt movement defines the distance the handle
18
swings upward. Immediately after the loader operator tilts the mounting plate
14
upward, the mounting plate
14
is tilted downward to allow the handle
18
to return to the surface. If the operator tilts the mounting plate
14
upward hard enough, the handle
18
will travel to a position (
FIG. 4B
) where the upper coil spring
38
will absorb energy and prevent over travel and accelerate the handle
18
back towards the surface (FIG.
4
C). Any shocks or vibrations are absorbed by the upper and lower springs
36
,
38
which stop fatigue to the skid steer loader
12
.
The hammer head
20
returns to the surface either by gravity or by acceleration from the upper coil spring
38
depending on the operator's needs. The hammer head
20
then impacts the surface causing the surface material to yield. The impact is magnified by a much smaller point
60
located on the center, bottom of the hammer head
20
. The entire process is repeated until the operator has reduced the surface material to a manageable size for removal. The operator then moves the skid steer loader
12
with the attachment
10
to an adjacent area and begins again. When the required area of surface material is broken up, the operator can drop the attachment
10
from the skid steer loader
12
by using the spring pins
68
to disconnect the mounting plate
14
from the adapter plate
28
, and install the standard bucket to begin removal of the material.
It should now be appreciated that the present invention provides a pavement demolition hammer which is low maintenance, low decibel and is environmentally friendly. This demolition hammer has a simplified, yet rugged construction with identical, interchangeable parts. Such hammer is noteworthy because it establishes a resonant vibration in the pavement so that cracking occurs throughout a larger area instead of simply penetrating a hole in a slab. The hammer has a quick recycle time with no latches or pins to catch and no stop hammer action between drops. The inventive design allows for 360 degrees motion of the loader to easily reach any direction and access corner work in an efficient manner. The hammer is an attractive cost alternative to more expensive breaking equipment.
While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only, and should not be deemed limitative on the scope of the invention set forth with the following claims.
Claims
- 1. A pavement demolition hammer removably fastened to a loader, comprising:a mounting plate securable to the loader; a framework attached to the mounting plate and provided with a lower spring and an upper spring spaced from the lower spring; and a hammer handle having a proximal end pivotally mounted to the framework for swinging movement between the lower spring and the upper spring, and a distal end equipped with a hammer head adapted to engage the pavement, whereby the loader applies a moving force to the mounting plate such that the lower spring is accelerated against a bottom of the handle causing the handle and the hammer head to swing upwardly from a pavement surface to be broken towards the upper spring, the handle and the hammer head returning to the pavement surface either by gravity or acceleration from the upper spring against a top of the handle in a manner such that the hammer head impacts and demolishes the pavement surface, wherein the mounting plate is a generally rectangular planar surface having a V-shaped bracket at an upper end, and a rearwardly extending lip with a pair of spaced apertures at a lower end, the bracket and the lip being removably engagable with an adapter plate on the loader, and wherein the framework includes a horizontally extending fork bottom disposed perpendicularly and forwardly of the mounting plate, a vertically extending fork top rising from a rearward end of the fork bottom along a forward surface of the mounting plate, and an upwardly and forwardly extending fork extension connected to an upper end of the fork top.
- 2. The demolition hammer of claim 1, wherein a forward end of the fork bottom carries the lower spring, and a forward end of the forked extension carries the upper spring, both the upper and lower springs being generally cylindrical coil springs.
- 3. The demolition hammer of claim 2, wherein the framework further includes a pair of parallel, spaced apart side plates, each side plate being attached to the fork bottom, fork top and fork extension.
- 4. The demolition hammer of claim 3, wherein the hammer handle is disposed to swing between the side plates.
- 5. The demolition hammer of claim 2, wherein the hammer handle is provided with an upper spring plate engagable with the upper spring, and a lower spring plate engagable with the lower spring.
- 6. The demolition hammer of claim 2, wherein the hammer handle is normally supported on the lower spring.
- 7. The demolition hammer of claim 2, wherein the hammer head extends beyond the forward end of the fork bottom.
- 8. The demolition hammer of claim 1, wherein the hammer head has a generally cylindrical configuration with a downwardly depending impact point.
- 9. A pavement demolishing hammer comprising:a loader having lifting arm structure, a hydraulic cylinder carried on the lifting structure and an adapter plate including a top end pivotally connected to the hydraulic cylinder and a bottom end pivotally secured to the lifting arm structure, the bottom end formed provided with a spring loaded pin; a framework including a mounting plate with a bracket having an upper end and an apertured lip at a lower end, the mounting plate bracket being engagable with the top end of the adapter plate and the spring loaded pin being engagable with the apertured lip, the framework further including a horizontally extending fork bottom disposed generally perpendicularly to the mounting plate, a vertically extending fork top to which the mounting plate is secured, and an upwardly and forwardly extending fork extension connected to the fork top, there being a lower cylindrical coil spring disposed on the fork bottom and an upper cylindrical coil spring located on the fork extension and a pair of spaced apart side plates, each attached to the fork bottom, fork top and fork extension; and a hammer handle having a rearward end pivotally attached to the fork top for pivotal movement between the side plates, and between the upper spring and the lower spring, and a forward end provided with a hammer head adapted to engage the pavement, whereby selective actuation of the hydraulic cylinder moves the mounting plate and framework such that the lower spring is accelerated against a bottom of the handle causing the handle and the hammer head to swing upwardly from the pavement towards the upper spring, the handle and the hammer head returning to the pavement either by gravity or acceleration from the upper spring against a top of the handle in a manner that the hammer head impacts the pavement.
US Referenced Citations (17)