Abstrict A horizontal impact crusher having a frame cover for accessing
the machine's crushing chamber is provided with hydraulic cover
latches for opening and closing the frame cover.
Claims What we claim is:
1. In a horizontal impact crusher having a base, a crusher frame
on said base, and an interior crushing chamber within said crusher
frame, said crusher frame including a stationary portion having
a first interior edge structure, and a cover portion movable between
a closed and open position to access said interior crushing chamber,
said cover portion having a second interior edge structure that
mates with the first interior edge structure of the stationary portion
of said frame when said cover portion is closed, a latch assembly
comprising
a latch mechanism secured to the edge structure of one of the stationary
and cover portions of said crusher frame, said latch mechanism being
moveable between an unlocked position where the cover portion of
said crusher frame can be opened and a locked position where the
cover portion of the crusher frame, when closed, is secured to the
stationary portion of the crusher frame,
hydraulic means for hydraulically moving said latch mechanism to
its unlocked position by exerting a sufficient hydraulic actuation
force thereon, and
spring means for mechanically biasing said latch mechanism to its
locked position in the absence of a sufficient hydraulic actuation
force from said hydraulic means whereby the latch mechanism remains
in a normally locked position.
2. The latch assembly of claim 1 wherein said latch mechanism is
in the form of a latch plate disposed to span the edge structures
of the stationary and cover portions of said crusher frame and wherein
said latch plate is raised to an unlocked position by said hydraulic
means and lowered to a locked position by said spring means.
3. The latch assembly of claim 2 further comprising at least one
mounting post extending from the edge structure of one of the stationary
and cover portions of said crusher frame, and wherein said latch
plate is slidably carried on said mounting post and is raised and
lowered thereon by said hydraulic means and spring means.
4. The latch assembly of claim 3 wherein said mounting post has
a head portion and said spring means includes a compression spring
disposed over said mounting post between the head portion thereof
and said latch plate so as to lower said latch plate on said mounting
post in the absence of a sufficient hydraulic actuation force from
said hydraulic means.
5. The latch assembly of claim 4 wherein said latch plate is carried
on at least two mounting posts and a compression spring is provided
for each mounting post.
6. The latch assembly of claim 4 wherein said hydraulic means includes
a hydraulic cylinder mounted directly to said latch plate.
7. The latch assembly of claim 4 wherein a latch post positioned
in opposition to said latch plate extends from the edge structure
of the other of the stationary and cover portions of said crusher
frame, and wherein said latch plate includes a latch post hole which
registers with said latch post when the cover portion of said frame
is in its closed position, whereby the latch plate lockingly engages
the latch post when the latch plate is lowered by said spring means.
8. In a horizontal impact crusher having a base, an upright crusher
frame on said base, and an interior crushing chamber within said
crusher frame, and wherein said crusher frame includes a stationary
portion having a first interior edge structure, and a cover portion
movable between a closed and open position to access said interior
crushing chamber, said cover portion having a second interior edge
structure that mates with the first interior edge structure of the
stationary portion of said frame when said cover portion is closed,
and said frame including latch means for latching the stationary
portion and moveable cover portion of said crusher frame together
in a closed position, the improvement comprising a latch means in
the form of at least one hydraulically actuated latch plate assembly
disposed to span and releasably secure the edge structures of the
stationary and cover portions of said crusher frame to releasably
maintain closure of said cover portion, said latch plate assembly
including
a latch post positioned along the edge structure of one of the
stationary and cover portions of said crusher frame,
a latch plate positioned along the edge structure of the other
of the stationary and cover portions of said frame in opposition
to said latch post, said latch plate extending over and having a
latch post hole which registers with said latch post when the cover
portion of said frame is in its closed position, and
hydraulic means for raising and lowering said latch plate when
the cover portion of said frame is in its closed position such that
said latch post is disengaged and engaged by said latch plate for
unlocking and locking the cover portion of the crusher frame.
9. The latch plate assembly of claim 8 wherein the hydraulic means
for raising and lowering said latch plate causes said latch plate
to rise by exerting a sufficient hydraulic actuation force thereon
and permits the latch plate to lower in the absence of said hydraulic
actuation force.
10. The latch plate assembly of claim 9 further comprising spring
means for mechanically biasing said latch plate so that it is lowered
onto said latch post in the absence of a sufficient hydraulic actuation
force from said hydraulic means whereby the latch plate remains
in a normally locked position.
11. The latch plate assembly of claim 8 wherein at least two latch
plate assemblies are provided along the interior edge structures
of said frame.
Description BACKGROUND OF THE INVENTION
The present invention generally relates to crushing machines for
materials benefication, and more particularly to horizontal impact
crushing machines and the need to periodically access the crushing
chamber for such machines.
Horizontal impact crushing machines are well-known in the art and
have been in use for many years. Such machines utilize "blow
bars" (sometimes called "breaker" or "impact"
bars) on the perimeter of a rotor assembly rotating at high speeds
to propel crushable material against work-hardened wall structures,
called "curtains." The resulting impact forces act to
pulverize the material fed into the crusher.
From time to time it is necessary to access the interior of a horizontal
impact crushing machine for maintenance purposes or to dislodge
uncrushable materials. Conventionally, such access is provided by
means of a frame cover that is rotated on the base of the machine
to an open position by means of a hydraulic cylinder. In a closed
position, such a frame cover is held to the stationary portion of
the frame by means of mechanical latches which are difficult to
access and operate, since they require an operator to climb up onto
the machine and physically undo the latches, which typically requires
a tool to break the latches free. The difficulty of gaining access
to the crusher having conventional cover latches leads to costly
down time, and creates conditions that can lead to injuries where
proper safety procedures are not followed. For example, if the machine
is accidentally turned on when a maintenance person is on the machine,
severe injury could result.
The present invention provides a means for latching and unlatching
the access cover of a horizontal impact crusher without the need
for a maintenance person to climb onto the machine for the purpose
of mechanically operating the latches. The invention permits the
access cover to be latched and unlatched quickly and efficiently,
thereby minimizing down time, and also reduces the risk of injury
to the maintenance person.
SUMMARY OF THE INVENTION
The present invention involves a horizontal impact crusher having
a base, an upright crusher frame supported on the base, and an interior
crushing chamber. The crusher frame is divided into a stationary
portion and a movable cover portion that is pivotally attached to
the base to permit the cover to pivot to an open position. Both
the stationary portion and movable covered portion of the frame
have interior edge structures which meet and are latched together
when the covered portion is in a closed position. In accordance
with the invention, latch means for the covered portion are provided
in the form of hydraulically actuated latch means which can be remotely
actuated without the need for a maintenance person to climb onto
the machine. The hydraulic latch means is preferably normally closed,
such that, the latches can only be unlatched with the application
of hydraulic pressure. Such a safety feature will prevent the accidental
unlatching of the frame cover due to loss of hydraulic pressure.
It is further contemplated that the crusher's motor can be interlocked
with the hydraulic latches, such that, for safety, the crusher cannot
be operated when the frame cover is open.
Therefore, it can be seen that a primary object of the invention
is to provide an efficient means of unlatching the access cover
of a frame of a horizontal impact crusher. Another object of the
invention is to provide a latching mechanism for the frame's cover
that will reduce down time and enhance the safety environment of
the crusher. Other objects of the invention will become apparent
from the following description and claims, as well as the accompanying
drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a horizontal impact crusher
having hydraulic cover latches in accordance with the invention.
FIG. 2 is a side elevational view of the horizontal impact crusher
shown in FIG. 1 with the frame cover opened.
FIG. 3 is a top plan view of the hydraulic latch plate assembly
of the invention attached to the interior edge structures of the
stationary and movable portions of the crusher frame.
FIG. 4 is a side elevational view of the latch plate assembly shown
in FIG. 3.
FIGS. 5A-5C are cross-sectional views of the latch plate assembly
shown in FIGS. 3 and 4 illustrating the operation of this assembly.
FIG. 6 is a block diagram of the hydraulic actuation circuit and
drive motor interlock of the invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
Referring now to the drawings, FIGS. 1 and 2 show the general configuration
of a horizontal impact crusher (denoted by the numeral 11) having
a base portion 13 an upright crusher frame 15 a top feed opening
17 and an internal crushing chamber 18. During operation, drive
motor 19 mounted to the exterior of frame 15 drives internal rotor
assembly 21 such that the rotor assembly's blow bars 23 propel crushable
material fed through feed opening 17 against the surfaces of a series
of internal curtain assemblies (not shown). The blow bars experience
considerable wear due to the rugged operating environment of the
crusher and because of this, the crushing chamber needs to be periodically
accessed to replace the blow bars, and to make other repairs. The
interior crushing chamber may also have to be accessed to remove
uncrushable material that find its way into the machine.
To permit such access, crusher frame 15 is seen to have a rear
cover portion 25 pivotally attached to base 13 at pivot point 27
which is actuated from a closed to an opened position as shown in
FIG. 2 by externally mounted hydraulic cylinders 29. It can be seen
that the frame's cover portion 25 which accounts for over half
of the crusher's total frame structure, breaks away from a front
stationary portion 31 of the frame just behind feed opening 17.
Both the stationary portion 31 and movable cover portion 25 have
mating interior edge structures 33 35 that extend from the top
of the crusher frame to the crusher's base 13. To provide reinforced
edges, each edge structure is lined with transversely extending
rim plates 34 36. It is noted that the crusher frame can also be
provided with smaller hatch doors, such as door 37 which can be
used for inspection and light maintenance purposes.
When closed, the movable frame cover 25 is latched to the stationary
frame portion 31 along interior edge structures 33 35 by hydraulically
actuated latch means in the form of two identical latch plate assemblies
39 41 positioned at two different locations along the mating interior
edge structures. These latch plate assemblies are now described
with reference to FIGS. 3-5 which illustrate the construction and
operation of latch plate assembly 41.
Latch plate assembly 41 is seen to include a latch post 43 secured
to side wall 45 of frame cover 25 just to the inside of rim plate
34. The rest of latch plate assembly 41 is mounted to the frame's
front stationary portion 31 opposite latch post 43. More specifically,
a latch mechanism in the form of latch plate 47 having post hole
49 is mounted to edge structure 35 of the stationary frame portion
by means of mounting bolts 51 which are anchored into mounting
block 53 welded into the frame corner formed by rim plate 36 and
the stationary frame's side wall 46. Locking plate 47 which is
slidably carried on mounting parts in the form of bolts 51 is biased
to the closed position shown in FIG. 5A by spring means in the form
of coil springs 55 which extend between the top of the latch plate
and the enlarged head portion provided by bolt heads 57. Washers
59 can suitably be provided between the ends of mounting springs
55 and the bolt heads.
As best seen in FIG. 4 hydraulic actuation of locking plate assembly
41 is accomplished by hydraulic cylinder 61 which is mounted to
latch plate 47 between the two spring loaded mounting bolts 51.
Hydraulic cylinder 61 can suitably be a commercially available low
pressure hydraulic cylinder having an operating range of 750 psi
to 1500 psi. One such commercially available cylinder is the series
LH low pressure hydraulic cylinder supplied by the Fluid Power Division
of Versa Tek Company.
The operation of the latch plate assembly is now described in reference
to FIGS. 5A-5C. When frame cover 25 is in its closed position, latch
plate 47 extends over and engages latch post 43 in the latch plate's
post hole 49. Compression springs 55 of the latch spring assembly
bias the latch plate into the normally closed locking position shown
in FIG. 5A, thereby locking the frame cover in place. When hydraulic
pressure is applied to hydraulic cylinder 61 latch plate 47 is
retracted to an unlocked position as shown in FIG. 5B to disengage
from post 43. When thusly retracted, the frame cover 25 can be swung
away from stationary frame 31 as shown in FIG. 5C. Loss of hydraulic
pressure will prevent the latch plate assembly from being opened.
When frame cover 25 is closed, it can be locked in place by latch
plate assemblies 39 41 by simply releasing the hydraulic pressure
to permit the locking plates of the assemblies to engage their associated
locking posts.
FIG. 6 generally illustrates in block diagram form the safety features
of the invention. A hydraulic circuit represented by block 63 is
provided to actuate the machine's latch plate assemblies from a
normally closed condition such that the frame cover cannot open
in the absence of hydraulic pressure. The hydraulic actuation circuit
is additionally employed to actuate an interlock 65 for preventing
the rotor assembly drive motor from operating when the hydraulic
latch assemblies are in an opened condition. Such a safety feature
will prevent any inadvertent operation of the machine when a worker
is in the vicinity of an open crusher. It will be appreciated that
a hydraulic actuation circuit and drive motor interlock can be provided
in accordance with designs well-known to persons of ordinary skill
in the art.
Therefore, it can be seen that the present invention provides a
means for readily and efficiently latching and unlatching the frame
cover of a horizontal impact crusher and at the same time improving
the crusher's safety environment. While the invention has been described
in considerable detail in the foregoing specification and the accompanying
drawings, it is understood that it is not intended that the invention
be limited to such detail, except as necessitated by the following
claims.
|