Information
-
Patent Grant
-
6435434
-
Patent Number
6,435,434
-
Date Filed
Monday, October 2, 200023 years ago
-
Date Issued
Tuesday, August 20, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Burns, Doane, Swecker & Mathis, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 241 27
- 241 294
- 241 197
- 241 242
- 241 243
- 241 73
- 241 300
-
International Classifications
-
Abstract
A mechanism for disintegrating breakable materials, such as wood, pipes, bricks, etc. includes a rotary drum having striker bars mounted thereon which disintegrate the breakable materials. Each striker bar has a notched cutting edge formed by a row of carbide tips sintered to an edge of a steel body. The cutting edge can be of serrated shape and/or scallop-shape.
Description
BACKGROUND AND OBJECTS OF THE INVENTION
The invention pertains to an apparatus for disintegrating breakable materials, such as wood, cinder block, brick, pipes, etc., and especially relates to striker bars, which disintegrate breakable materials by being impacted thereagainst.
It is conventional to disintegrate or comminute breakable materials such as wood and residual building materials, e.g., bricks, concrete blocks, pipes, for example, by means of so-called hammer hogs, hammer mills, rotor hogs, tub grinders, etc. Those devices operate under the basic principle of rotating a drum to bring grinding elements, carried by the drum, into contact with the materials to be ground. The grinding elements have straight edges that can be hard-faced with carbide, which contact the materials and produce a grinding or crushing action which gradually wears away the materials. As pieces of the materials become ground small enough, they travel through a screen or grating which partially surrounds the drum at a slight distance. The screen can be disposed above or below the drum, and the materials can be introduced between the drum and screen in a radial or axial direction with reference to an axis of rotation of the drum. The grinding elements can be fixed to the drum so as to be immovable relative thereto, or swingable relative to the drum about respective hinge pins.
Material disintegrators of that general type are disclosed, for example, in U.S. Pat. Nos. 4,066,216; 5,165,611; 5,096,129; 5,950,942 and 4,586,663. Depicted in the accompanying
FIG. 1
is a driven rotary drum
10
of the general type disclosed in U.S. Pat. No. 5,165,611. The drum includes a plurality of coaxial segments
12
, each having circumferentially spaced seats for receiving respective striker plates or bars
20
′. Each striker bar
20
′ is bolted to its respective seat and presents a straight edge
14
which engages and crushes the material introduced through an inlet
13
. As the material becomes crushed into pieces of a small enough size, the pieces pass through a grate
16
disposed beneath the drum.
Since the striker bars
20
′ function primarily to crush and grind the materials, considerable energy is expended during operation. Also, much dust and small particles are produced. The cutting edges, even though having been hard-faced with carbide, tend to wear at a relatively rapid rate.
It would be desirable, therefore, to provide a striker bar which requires less energy while increasing the throughput rate of the materials. It would also be desirable to enable the amount of dust and small particles generated during operation to be reduced, as well as to increase the useful life of the striker bars.
SUMMARY OF THE INVENTION
The present invention relates to a striker bar adapted for use on a rotary holder for disintegrating materials. The striker bar comprises a support body having top and bottom surfaces. The top surface includes an edge portion. Cutting tips are fixed to the body and extend along the edge portion. The cutting tips are formed of a harder material than the body, and the cutting tips together form a notched cutting edge, such as a serrated or scallop shaped cutting edge.
The invention also pertains to an apparatus for disintegrating breakable materials, comprising a rotary drum and a plurality of the above-described striker bars mounted thereon.
The invention also pertains to a method of disintegrating material by rotating such a drum.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings in which like numerals designate like elements and in which:
FIG. 1
is a schematic side elevational view of a prior art material-disintegrating apparatus;
FIG. 2
is a top plan view of a blank portion of a striker bar according to the present invention;
FIG. 3
is a side elevational view of the blank depicted in
FIG. 2
;
FIG. 4
is an end elevational view of the blank depicted in
FIG. 2
;
FIG. 5
is a top plan view of a first embodiment of a striker bar according to the present invention;
FIG. 6
is a side elevational view of
FIG. 5
;
FIG. 7
is an end elevational view of
FIG. 5
;
FIG. 8
is a fragmentary side view showing the striker bar of
FIGS. 5-7
mounted on a rotary drum;
FIG. 9
is a top plan view of a second embodiment of striker bar according to the present invention;
FIG. 10
is a side elevational view of
FIG. 9
;
FIG. 11
is an end elevational view of
FIG. 9
;
FIG. 12
is a fragmentary side view showing the striker bar of
FIGS. 9-11
mounted on a rotary drum;
FIG. 13
is a top plan view of a third embodiment of a striker bar according to the present invention;
FIG. 14
is a side elevational view of
FIG. 13
;
FIG. 15
is an end elevational view of
FIG. 13
; and
FIG. 16
is a fragmentary side view showing the striker bar of
FIGS. 13-15
mounted on a rotary drum.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
A striker bar
20
(see
FIGS. 2-4
) according to the present invention comprises a blank or support body
21
and a plurality of cutting tips
60
mounted thereon. The blank is in the form of a generally rectangular steel body
22
having a center mounting portion
24
and first and second identical edge portions
26
,
26
disposed at opposite ends of a top surface
28
of the body (see FIGS.
2
-
4
). The body also includes a bottom surface
30
. Through-holes
32
are formed through the mounting portion
24
for receiving fasteners to secure the striker bar to a drum or other rotary holder.
The top surface
28
has two grooves
40
, each formed between the mounting portion
24
and a respective edge
26
. Each groove
40
includes an inner surface
46
and an outer surface
48
, the surfaces
46
and
48
oriented at a right angle with one another, whereby the groove is of generally V-shaped cross section as the blank is viewed from the side (see FIG.
3
). The outer surface
48
is inclined upwardly and outwardly from a lower end of the inner surface
46
.
Each edge includes spaced apart notches
41
, and the tips
43
of the thus-notched edge
26
are curved, resulting in a scallop-like edge configuration (see FIG.
2
). The regions of the surface
48
that are separated by the notches constitute laterally adjacent projections which define support surfaces
39
. Sintered onto each of the support surfaces
39
is a preformed cutting tip formed of a harder material than the body
21
. For example, the body
21
can be formed of steel, and the cutting tips could be formed of carbide. At each end of the body
21
there is thus provided a row of cutting tips which cooperate to form a generally scallop-shaped cutting edge.
Three preferred cutting tip configurations are disclosed herebelow. A first of those cutting tips
60
is depicted in
FIGS. 5-8
. That cutting tip
60
includes a flat bottom face
61
seated on the respective support surface
39
, a flat top rake face
62
, a clearance face
63
, and a convexly curved cutting edge segment
64
which follows the contour of the outer edge
26
of the support surface
39
. The cutting edge segment
64
is defined by a line of intersection between the rake face
62
and the clearance face
63
. The cutting edge segments
64
at each end of the striker bar
20
together form a notched cutting edge, preferably of scallop-shape, whereby the striker bar
20
has two scallop-shaped cutting edges at respective ends of the striker bar that are usable alternatively, i.e., the striker bar can be reversed to present a new scalloped cutting edge. Adjacent ones of the cutting tips
60
are spaced apart by a notch arranged in overlying relationship to one of the notches
41
, as is evident from FIG.
5
. In lieu of a scallop shape, the tips could be pointed to form a serrated cutting edge. Eventually, the points would wear and the edges would assume a scallop shape.
In use, the striker bars
20
are mounted on the rotary drum of an apparatus such as that shown in
FIG. 1
for example (i.e., in lieu of the striker bars
20
′ shown therein). As shown in
FIG. 8
, the orientation of each striker bar
20
is such that a rake angle A (defined as a positive rake herein) formed by a drum radius R and a plane of the rake face
62
of each active cutting tip
60
is in the range of about 6 to 9 degrees, preferably about 8 degrees. Also, a clearance angle B formed by a drum tangent T and a plane of the clearance face
63
is in the range of 23-27 degrees, preferably about 25 degrees.
Breakable materials, such as wood, pipe, concrete blocks, bricks, etc., would be introduced through the inlet
13
and acted upon by the cutting edges of the striker bars
20
as the striker bars pass across the grate
16
. The cutting edges, due to their notched shape, form teeth that are able to effectively cut through the materials rather than merely crushing the materials as do conventional striker bars. This serves to lower the energy required to disintegrate the materials and reduce the amount of dust and small particles that is generated and entrained in the surrounding air. The disintegration is performed relatively quickly, enabling the production rate to be increased. Also, the cutting edges tend to be self sharpening and therefore last longer.
The inventive striker bars
20
can be mounted on any type of apparatus, including but not limited to the apparatus shown in FIG.
1
.
A striker bar
120
having alternative cutting tips
160
is depicted in
FIGS. 9-12
. The striker bar includes a blank
21
preferably configured the same as in the embodiment disclosed in connection with
FIGS. 5-8
. The cutting tip
160
, rather than having a flat top surface, has a top surface
162
comprised of portions that converge upwardly to form a somewhat sharp edge
164
. The front surface
163
of each tip is of generally rounded convex shape. Thus, each notched cutting edge is of generally scallop shape when the striker bar is viewed in a first direction toward the top surface, (
FIG. 9
) and of generally serrated shape when the striker bar is viewed in a second direction perpendicular to the first direction (FIG.
11
). When mounted on a drum
12
(FIG.
12
), the rake angle
1
A is positive and in the range of about 6 to 9 degrees, preferably about 8 degrees. The clearance angle
1
B is in the range of about 23-27 degrees, preferably about 26 degrees (see FIG.
12
).
A third striker bar configuration
220
is depicted in
FIGS. 13-16
. In that embodiment, the cutting tip
260
has a top surface
262
which forms an edge
264
, as well as a front surface
263
which also forms an edge
266
that is aligned with the edge
264
when the striker bar is viewed in plan (FIG.
13
). Thus, each notched cutting edge is of generally serrated shape as viewed either in plan (
FIG. 13
) or from the end (FIG.
15
). When mounted on a drum
12
, each cutting tip forms a negative rake angle
2
A in the range of −10 to −15 degrees, preferably about −12 degrees, and a clearance angle
2
B in the range of 23-27 degrees, preferably about 26 degrees.
It will be appreciated that a striker bar
20
,
120
,
220
according to the present invention includes a notched cutting edge formed by hard cutting edges which are able to cut through a bulk inflow of breakable materials, rather than merely crushing them. That reduces energy expenditures and dust formation, as well as accelerating the disintegration rate of the materials.
Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims
- 1. A striker bar adapted for use on a rotary holder for disintegrating breakable materials, the striker bar comprising a support body having top and bottom surfaces, the top surface including an edge portion, the edge portion comprising a plurality of projections spaced apart by at least one first notch, a row of cutting tips fixed to the body and extending along the edge portion; the cutting tips mounted on respective ones of the projections and spaced apart by at least one second notch arranged in overlying relationship to the at least one first notch, the cutting tips formed of a harder material than the body; the row of cutting tips together forming a notched cutting edge, with each tip forming a segment of the notched cutting edge.
- 2. The striker bar according to claim 1 wherein the notched cutting edge is generally scallop-shaped.
- 3. The striker bar according to claim 1 wherein the notched cutting edge is generally serrated-shaped.
- 4. The striker bar according to claim 1 wherein the cutting edge is scallop-shaped when the insert is viewed in a first direction toward the top surface, and serrated-shaped when the insert is viewed in a direction perpendicular to the first direction.
- 5. The striker bar according to claim 1 wherein the body is of generally rectangular shape, there being two of the edge portions disposed at opposite ends of the body.
- 6. The striker bar according to claim 1 wherein the edge portion of the body includes a groove formed by an upwardly facing mounting surface and a generally upright side surface facing away from a center of the body; the mounting surface including a notched edge corresponding to the notched cutting edge.
- 7. The striker bar according to claim 6 wherein the supporting surface is inclined upwardly in a direction away from a center of the body.
- 8. The striker bar according to claim 1 wherein the edge portion comprises more than two projections, adjacent ones of the projections separated by a notch.
- 9. The striker bar according to claim 1 wherein the top surface is generally flat.
- 10. The striker bar according to claim 1 wherein the top surface includes two portions converging upwardly to form an edge.
- 11. The striker bar according to claim 10 wherein the top surface is generally arc-shaped as viewed in side elevation.
- 12. The striker bar according to claim 1 wherein the front surface includes two portions converging to form an edge.
- 13. The striker bar according to claim 1 wherein the body is formed of steel, and the cutting tips are formed of cemented carbide.
- 14. An apparatus for disintegrating breakable materials, comprising:a rotary drum; and a plurality of striker bars mounted on the drum, each striker bar including: a body having top and bottom surfaces, the top surface including a plurality of edge portions, at least one of the edge portions comprising a plurality of projections spaced apart by at least one first notch, a row of cutting tips fixed to the body and extending along the at least one edge portion; the cutting tips mounted on respective ones of the projections and spaced apart by at least one second notch arranged in overlying relationship to the at least one first notch, the cutting tips formed of a harder material than the body; the row of cutting tips together forming a notched cutting edge, with each tip forming a section of the notched cutting edge.
- 15. The apparatus according to claim 14 wherein each striker bar is oriented on the drum to form a rake angle in the range of about 6 to 9 degrees, and a clearance angle in the range of about 23-27 degrees.
- 16. The apparatus according to claim 14 wherein each striker bar is oriented on the drum to form a rake angle in the range of about −10 to −15 degrees, and a clearance angle in the range of 23 to 27 degrees.
US Referenced Citations (11)