Note: Descriptions are shown in the official language in which they were submitted.
CA 2720159 2017-02-27
TITLE OF INVENTION
Hammer
CROSS REFERENCE TO RELATED APPLICATIONS
Applicant states that this utility patent application claims priority from US
Pat. App. No. 12/882,422,
which patent application claims priority from US Pat. App. No. 12/398,007,
which application is
related to US Pat. App. No. 11/897,586 filed on 08/31/2007, which application
is related to
US Pat. App. No. 11/544,526 (now US Pat. No. 7,559,497) filed on 10/06/2006,
which
application is related to US Pat. App. No. 11/150,430 now (US Pat. No.
7,140,569) filed on
06/11/2005, which application is related to US Pat. App. No. 10/915,750 filed
on 08/11/2004.
Applicant also claims priority from provisional US Pat. App. No. 61/257,958
filed on
11/04/2009.
FIELD OF INVENTION
This invention relates generally to a device for comminuting or grinding
material. More
specifically, the invention is especially useful for use as a hammer in a
rotatable hammermill
assembly.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
No federal funds were used to develop or create the invention disclosed and
described in the
patent application.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISK APPENDIX
Not Applicable
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BACKGROUND
A number of different industries rely on impact grinders or hammermills to
reduce
materials to a smaller size. For example, hammermills are often used to
process forestry
and agricultural products as well as to process minerals, and for recycling
materials.
Specific examples of materials processed by hammermills include grains, animal
food, pet
food, food ingredients, mulch and even bark. This invention although not
limited to grains,
has been specifically developed for use in the grain industry. Whole grain
corn essentially
must be cracked before it can be processed further. Dependent upon the
process, whole
corn may be cracked after tempering yet before conditioning. A common way to
carry out
particle size reduction is to use a hammermill where successive rows of
rotating hammer
like devices spinning on a common rotor next to one another comminute the
grain product.
For example, methods for size reduction as applied to grain and animal
products are
described in Watson, S. A. & P. E. Ramstad, ed. (1987, Corn: Chemistry and
Technology,
Chapter 11, American Association of Cereal Chemist, Inc., St. Paul, Minn.).
The
application of the invention as disclosed and herein claimed, however, is not
limited to
grain products or animal products.
Hammermills are generally constructed around a rotating shaft that has a
plurality of disks
provided thereon. A plurality of free-swinging hammers are typically attached
to the
periphery of each disk using hammer rods extending the length of the rotor.
With this
structure, a portion of the kinetic energy stored in the rotating disks is
transferred to the
product to be comminuted through the rotating hammers. The hammers strike the
product,
driving into a sized screen, in order to reduce the material. Once the
comminuted product is
reduced to the desired size, the material passes out of the housing of the
hammermill for
subsequent use and further processing. A hammer mill will break up grain,
pallets, paper
products, construction materials, and small tree branches. Because the
swinging hammers
do not use a sharp edge to cut the waste material, the hammer mill is more
suited for
processing products which may contain metal or stone contamination wherein the
product
the may be commonly referred to as "dirty". A hammer mill has the advantage
that the
rotatable hammers will recoil backwardly if the hammer cannot break the
material on
impact. One significant problem with hammer mills is the wear of the hammers
over a
relatively short period of operation in reducing "dirty" products which
include materials
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such as nails, dirt, sand, metal, and the like. As found in the prior art,
even though a hammermill
is designed to better handle the entry of a "dirty" object, the possibility
exists for catastrophic
failure of a hammer causing severe damage to the hammermill and requiring
immediate
maintenance and repairs.
Hammermills may also be generally referred to as crushers - which typically
include a steel
housing or chamber containing a plurality of hammers mounted on a rotor and a
suitable drive
train for rotating the rotor. As the rotor turns, the correspondingly rotating
hammers come into
engagement with the material to be comminuted or reduced in size. Hammermills
typically use
screens formed into and circumscribing a portion of the interior surface of
the housing. The size
of the particulate material is controlled by the size of the screen apertures
against which the
rotating hammers force the material. Exemplary embodiments of hammermills are
disclosed in
U.S. Pat. Nos. 5,904,306; 5,842,653; 5,377,919; and 3,627,212.
The four metrics of strength, capacity, run time and the amount of force
delivered are typically
considered by users of hammermill hammers to evaluate any hammer to be
installed in a
hammermill. A hammer to be installed is first evaluated on its strength.
Typically, hammermill
machines employing hammers of this type are operated twenty-four hours a day,
seven days a
week. This punishing environment requires strong and resilient material that
will not prematurely
or unexpectedly deteriorate. Next, the hammer is evaluated for capacity, or
more specifically,
how the weight of the hammer affects the capacity of the hammermill. The
heavier the hammer,
the fewer hammers that may be used in the hammermill by the available
horsepower. A lighter
hammer then increases the number of hammers that may be mounted within the
hammermill for
the same available horsepower. The more force that can be delivered by the
hammer to the
material to be comminuted against the screen increases effective comminution
(i.e. cracking or
breaking down of the material) and thus the efficiency of the entire
comminution process is
increased. In the prior art, the amount of force delivered is evaluated with
respect to the weight
of the hammer.
Finally, the length of run time for the hammer is also considered. The longer
the hammer lasts,
the longer the machine run time, the larger profits presented by continuous
processing of the
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material in the hammermill through reduced maintenance costs and lower
necessary capital
inputs. The four metrics are interrelated and typically tradeoffs are
necessary to improve
performance. For example, to increase the amount of force delivered, the
weight of the hammer
could be increased. However, because the weight of the hammer increased, the
capacity of the
unit typically will be decreased because of horsepower limitations. There is a
need to improve
upon the design of hammermill hammers available in the prior art for
optimization of the four (4)
metrics listed above.
Free-Swinging Hammermill Assemblies
Rotatable hammermill assemblies as found in the prior art, which are well
known and therefore
not pictured herein, generally includes two end plates on each end with at
least one interior plate
positioned between the two end plates. The end plates include an end plate
drive shaft hole and
the interior plates include an interior plate drive shaft hole. A hammermill
drive shaft passes
through the end plate drive shaft holes and the interior plate drive shaft
holes. The end prates and
interior plates are affixed to the hammermill drive shaft and rotatable
therewith.
Each end plate also includes a plurality of end plate hammer rod holes, and
each interior plate
includes a plurality of interior plate hammer rod holes. A hammer rod passes
through
corresponding end plate hammer rod holes and interior plate hammer rod holes.
A plurality of
hammers is pivotally mounted to each hammer rod. The hammers are typically
oriented in rows
along each hammer rod, and each hammer rod is typically oriented parallel to
one another and to
the hammermill drive shaft.
The hammermill assembly and various elements thereof rotate about the
longitudinal axis of the
hammermill drive shaft. As the hammermill assembly rotates, centrifugal force
causes the
hammers to rotate about the hammer rod to which each hammer is mounted. Free-
swinging
hammers are often used instead of rigidly connected hammers in case lodged
metal, foreign
objects, or other non-crushable material enters the housing with the
particulate material to be
reduced, which material may be a cereal grain
For effective comminution in hammermill assemblies using free-swinging
hammers, the
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rotational speed of the hammermill assembly must produce sufficient
centrifugal force to hold
the hammers as close to the fully extended position as possible when material
is being
communited. Depending on the type of material being processed, the minimum
hammer tip
speeds of the hammers are usually 5,000 to 11,000 feet per minute (FPM). In
comparison, the
maximum speeds depend on shaft and bearing design, but usually do not exceed
30,000 FPM. In
special high-speed applications, the hammermill assemblies may be configured
to operate up to
60,000 FPM.
In the case of disassembly for the purposes of repair and replacement of worn
or damaged parts,
the wear and tear causes considerable difficulty in realigning and
reassembling the various
elements of the hammermill assembly. Moreover, the elements of the hammermill
assembly are
typically keyed to one another, or at least to the hammermill drive shaft,
which further
complicates the assembly and disassembly process. For example, the replacement
of a single
hammer may require disassembly of the entire hammermill assembly. Given the
frequency at
which wear parts require replacement, replacement and repairs constitute an
extremely difficult
and time consuming task that considerably reduces the operating time of the
size reducing
machine.
Applicant is the inventor on various other patents and patent applications
relating to hammers for
use in comminuting materials. Accordingly, U.S. Pat. Nos. 7,140,569;
7,559,497; and 7,621,477
and U.S. Pub. App. No. 2009/0224090.
Although not shown in detail herein, one of ordinary skill will appreciate
that the present art may
be applied to the designs and inventions protected by patents held by
Applicant or others without
limitation, dependent only upon a particular need or application, including:
Patent Number Title
D.588,174 Hammermill hammer
D573,163 Hammermill hammer
D555,679 Hammermill hammer
D552,639 Hammermill hammer
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D551,267 Hammermill hammer
D551,266
Hammermill hammer
D550,728
Hammermill hammer
D545,847
Hammermill hammer
D545,846
Hammermill hammer
D545,328
Hammermill hammer
D545,327
Hammermill hammer
D544,504
Hammermill hammer
D544,503
Hammermill hammer
D536,352
Hammermill hammer
D536,351
Hammermill hammer
D536,350
Hammermill hammer
SUMMARY OF INVENTION
In accordance with one aspect of the present invention, there is provided a
hammer for use in a rotatable
hammermill assembly, said hammer comprising: a) a connector end; b) a rod hole
positioned in said
connector end; c) a neck having a first and second end, said neck first end
connected to said connector end;
d) a contact end connected to said neck second end; and e) a neck recess
formed in said neck between said
neck first and second ends.
In accordance with another aspect of the present invention, there is provided
a hammer for use in a rotatable
hammermill assembly, said hammer comprising: a) a connector end; b) a rod hole
positioned in said
connector end; c) a first shoulder surrounding a portion of said rod hole; d)
a second shoulder surrounding
a portion of said rod hole; e) a neck having a first and second end, said neck
first end connected to said
connector end; f) a contact end connected to said neck second end; and g) a
neck recess formed in said neck
between said neck first and second ends.
In accordance with another aspect of the present invention, there is provided
a hammer for use in a rotatable
hammermill assembly, said hammer comprising: a) a connector end; b) a first
shoulder positioned on said
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connector end; c) a second shoulder surrounding a portion of said first
shoulder, wherein said first shoulder
and said second shoulder are configured such that a rod hole may be positioned
in said connector end within
the periphery of said first shoulder and said second shoulder at various
positions along the length of said
hammer; d) a neck having a first and second end, said neck first end connected
to said connector
end; and e) a contact end connected to said neck second end.
In accordance with another aspect of the present invention, there is provided
a hammer for use in a
rotatable hammermill assembly, said hammer comprising: a) a connector end; b)
a rod hole positioned in
said connector end; c) a neck having a first and second end, said neck first
end connected to said
connector end; d) a contact end connected to said neck second end; e) a neck
recess formed in said neck
between said neck first and second ends; f) a first shoulder adjacent top and
surrounding a first portion of
said rod hole; and, g) a second shoulder adjacent to and surrounding a second
portion of said rod hole,
wherein said first shoulder and said second shoulder are non-symmetrical about
the longitudinal axis of
said rod hole.
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BRIEF DESCRIPTION OF THE FIGURES
In order that the advantages of the invention will be readily understood, a
more particular
description of the invention briefly described above will be rendered by
reference to specific
embodiments illustrated in the appended drawings. Understanding that these
drawings depict
only typical embodiments of the invention and are not therefore to be
considered limited of its
scope, the invention will be described and explained with additional
specificity and detail
through the use of the accompanying drawings.
FIG. 1 provides a perspective view of the intemal configuration of a hammer
mill at rest as
commonly found in the prior art.
FIG. 2 provides a perspective view of the internal configuration of a
hammermill during
operation as commonly found in the prior art.
FIG. 3 provides an exploded perspective view of a hammermill as found in the
prior art as shown
in FIG. 1.
FIG. 4 provides an enlarged perspective view of the attachment methods and
apparatus as found
in the prior art and illustrated in FIG. 3.
FIG. 5 provides a perspective view of a first embodiment of a notched hammer.
FIG. 6 provides a top view of the first embodiment of a notched hammer.
FIG. 7 provides a detailed perspective view of the rod hole of the first
embodiment of a notched
hammer.
FIG. 8 provides a perspective view of a second embodiment of a notched hammer.
FIG. 9 provides a perspective view of a third embodiment of a notched hammer.
FIG. 10 provides a perspective view of a fourth embodiment of a notched
hammer.
FIG. 11 provides a perspective view of a fifth embodiment of a notched hammer.
FIG. 12 provides a perspective view of a sixth embodiment of a notched hammer.
FIG. 13 provides a perspective view of a seventh embodiment of a notched
hammer.
FIG. 14 provides a perspective view of an eighth embodiment of a notched
hammer.
FIG. 15 provides a perspective view of a ninth embodiment of a notched hammer.
FIG. 16 provides a perspective view of a first embodiment of a multiple blade
hammer.
FIG. 17 provides a top view of the first embodiment of a multiple blade
hammer.
FIG. 18 provides a perspective view of a second embodiment of a multiple blade
hammer.
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FIG. 19 provides a perspective view of one embodiment of a dual-blade hammer.
FIG. 20 provides a front view of one embodiment of the dual-blade hammer.
FIG, 21 provides a side view of one embodiment of the dual-blade hammer.
FIG. 22 provides a second perspective view of one embodiment of the dual-blade
hammer.
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DETAILED DESCRIPTION ¨ LISTING OF ELEMENTS
ELEMENT DESCRIPTION ELEMENT NUMBER
Hammermill assembly 2
Hammermil drive shaft 3
End plate 4
End plate drive shaft hole 5a
End plate hammer rod hole 5b
Interior plate 6
Interior plate drive shaft hole 7a
Interior plate hammer rod hole 7b
Hammer rod 8
Spacer 8a
Hammer (prior art) 9
Hammer body (prior art) 9a
Hammer contact edge (prior art) 9b
Hammer rod hole (prior art) 9c
Notched hammer 10
Notched hammer neck 11
Neck void 1 la
Notched hammer first end 12
Notched hammer first shoulder 14a
Notched hammer second shoulder I 4b
Notched hammer rod hole 15
Rod hole notch 15a
Notched hammer second end 16
Hardened contact edge 20
First contact surface 22a
First contact point 22b
Second contact surface 24a
Second contact point 24b
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Third contact surface 26a
Third contact point 26b
Fourth contact point 28
Edge pocket 29
Multiple blade hammer 30
Multiple blade hammer neck 31
Multiple blade Ilammer first end 32
Multiple blade hammer first shoulder 34a
Multiple blade hammer second shoulder 34b
Multiple blade hammer rod hole 35
Multiple blade hammer second end 36
First blade 37a
Second blade 37b
Third blade 37c
Blade edge 38
Dual-blade hammer 110
Connector end 120
Rod hole 122
First shoulder 124a
Second shoulder I24b
Notch 126
Neck 130
Neck first end 132
Neck second end 134
Neck recess 136
Neck edge 138
Contact end 140
First contact surface 142a
Second contact surface 142b
Interstitial area 144
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DETAILED DESCRIPTION¨EXEMPLARY EMBODIMENTS
Before the various embodiments of the present invention are explained in
detail, it is to be
understood that the invention is not limited in its application to the details
of construction and the
arrangements of components set forth in the following description or
illustrated in the drawings.
The invention is capable of other embodiments and of being practiced or of
being carried out in
various ways. Also, it is to be understood that phraseology and terminology
used herein with
reference to device or element orientation (such as, for example, terms like
"front", "back", "up",
"down", "top", "bottom", and the like) are only used to simplify description
of the present
invention, and do not alone indicate or imply that the device or element
referred to must have a
particular orientation. In addition, terms such as "first", "second", and
"third" are used herein and
in the appended claims for purposes of description and are not intended to
indicate or imply
relative importance or significance. Furthermore, any dimensions recited or
called out herein are
for exemplary purposes only and are not meant to limit the scope of the
invention in any way
unless so recited in the claims.
DETAILED DESCRIPTION
I. Free-Swinging Hammermill Assemblies
Referring now to the drawings, wherein like reference numerals designate
identical or
corresponding parts throughout the several views, FIGS. 1-3 show a hammermill
assembly 2 as
found in the prior art. The hammermill assembly 2 includes two end plates 4 on
each end with at
least one interior plate 6 positioned between the two end plates 4. The end
plates 4 include an
end plate drive shaft hole 5a and the interior plates 6 include an interior
plate drive shaft hole 7a.
A hammermill drive shaft 3 passes through the end plate drive shaft holes 5a
and the interior
plate drive shaft holes 7a. The end plates 4 and interior plates 6 are affixed
to the hammermill
drive shaft and rotatable therewith.
Each end plate 4 also includes a plurality of end plate hammer rod holes 5b,
and each interior
plate 6 includes a plurality of interior plate hammer rod holes 7b. A hammer
rod 8 passes
through corresponding end plate hammer rod holes 5b and interior plate hammer
rod holes 7b. A
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plurality of hammers 9 are pivotally mounted to each hammer rod 8, which is
shown in detail in
FIG. 4, The hammers 9 are typically oriented in rows along each hammer rod 8,
and each
hammer rod 8 is typically oriented parallel to one another and to the
hammermill drive shaft 3.
Each hammer 9 includes a hammer body 9a, hammer contact edge 9b, and a hammer
rod hole 9c
passing through the hammer body 9a, which is shown in detail in FIG. 4. Each
hammer rod 8
passes through the hammer rod hole 9c of at least one hammer 9. Accordingly,
the hammers 9
pivot with respect to the hammer rod 8 to which they are attached about the
center of the hammer
rod hole 9c. A spacer 8a may be positioned around the hammer rod 8 and between
adjacent
hammers 9 or adjacent hammers 9 and plates 4, 6 to better align the hammers 9
and/or plates 4,
6, which is best shown in FIGS. 3-4. As is well known to those of skill in the
art, a lock collar
(not shown) would typically be placed on the end of the hammer rod 8 to
compress and hold the
spacers 8a and the hammers 9 in alignment. All these parts require careful and
precise alignment
relative to one another. This type of hammer 9, which is shown affixed to the
hammermill
assembly 2 shown in FIGS. 1-3 and separately in FIG. 4, is commonly referred
to as free-
swinging hammers 9. Free-swinging hammers 9 are hammers 9 that are pivotally
mounted to the
hammermill assembly 9 in a manner as described above and are oriented
outwardly from the
center of the hammermill assembly 2 by centrifugal force as the hammermill
assembly 2 rotates.
The hammermill assembly 2 and various elements thereof rotate about the
longitudinal axis of
the hammermill drive shaft 3. As the hammermill assembly 2 rotates,
centrifugal force causes the
hammers 9 to rotate about the hammer rod 8 to which each hammer 9 is mounted.
The
hammermill assembly 2 is shown at rest in FIG. 1 and in a dynamic state in
FIG. 2, as in
operation. Free-swinging hammers 9 are often used instead of rigidly connected
hammers in case
tramped metal, foreign objects, or other non-crushable material enters the
housing with the
particulate material to be reduced, such as grain.
For effective comminution in hammermill assemblies 2 using free-swinging
hammers 9, the
rotational speed of the hammermill assembly 2 must produce sufficient
centrifugal force to hold
the hammers 9 as close to the fully extended position as possible when
material is being
communited. Depending on the type of material being processed, the minimum
hammer tip
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speeds of the hammers are usually 5,000 to 11,000 feet per minute ("FPM"). In
comparison, the
maximum speeds depend on shaft and bearing design, but usually do not exceed
30,000 FPM. In
special high-speed applications, the hammermill assemblies 2 may be configured
to operate up to
=
60,000 FPM.
In the case of disassembly for the purposes of repair and replacement of worn
or damaged parts,
the wear and tear causes considerable difficulty in realigning and
reassembling the various
elements of the hammermill assembly 2. Moreover, the elements of the
hammermill assembly 2
are typically keyed to one another, or at least to the hammermill drive shaft
3, which further
complicates the assembly and disassembly process. For example, the replacement
of a single
hammer 9 may require disassembly of the entire hammermill assembly 2. Given
the frequency at
which wear parts require replacement, replacement and repairs constitute an
extremely difficult
and time consuming task that considerably reduces the operating time of the
size reducing
machine. Removing a single damaged hammer 9 may take in excess of five (5)
hours due to both
the hammermill assembly 2 design and the realignment difficulties related to
the problems
caused by impact of debris with the non-impact surfaces of the hammermill
assembly 2.
Another problem found in the prior art hammermill assemblies 2 shown in FIGS.
1-3 is exposure
of a great deal of the surface area of the hammermill assembly 2 elements to
debris. The end
plates 4 and interior plates 6, spacers 8a, and hammers 9 are all subjected to
considerable contact
with the debris and material within the hammermill assembly 2. This not only
creates excessive
wear, but contributes to realignment difficulties by bending and damaging of
the various
elements of the hammermill assembly 2, which may be caused by residual impact.
Thus, after a
period of operation, prior art hammermill assemblies 2 become even more
difficult to
disassemble and reassemble. The problems related to comminution service and
maintenance of
hammermill assemblies 2 provides abundant incentive for improvement of hammers
9 to
lengthen operational run times.
2. Illustrative Embodiments of Notched Hammer
FIGS. 5-6 show a first embodiment of the notched hammer 10 for use in a
rotatable hammermill
assembly 2, which type of hammermill assembly 2 was previously described
herein. The notched
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hammer 10 is comprised of a notched hammer first end 12 (also referred to
herein occasionally
as the securement end) for securement within the hammermill assembly 2 and a
notched hammer
second end 16 (also referred to herein occasionally as the contact end) for
delivery of mechanical
energy to and contact with the material to be comminuted. The notched hammer
first end 12 is
connected to the notched hammer second end 16 by a notched hammer neck 11. A
notched
hammer rod hole 15 is centered in the notched hammer first end 12 for
engagement with and
attachment of the notched hammer 10 to the hammer rod 8 of a hammermill
assembly 2.
Typically, the distance from the center of the notched hammer rod hole 15 to
the most distal edge
of the notched hammer second end 16 is referred to as the "hammer swing
length."
As shown generally in FIGS. 5-6 and in detail in FIG. 7, at least one rod hole
notch 15a is
formed in the notched hammer rod hole 15. The at least one rod hole notch 15a
transverses the
length of the notched hammer rod hole 15 and is aligned with the notched
hammer neck 11. As
shown in the various embodiments pictured and described herein, the
longitudinal axis of the rod
hole notch 15a is parallel with the longitudinal axis of the notched hammer
rod hole 15, but may
have different orientations in embodiments not pictured or described herein,
such as an
embodiment wherein the rod hole notch 15a is not parallel to the longitudinal
axis of the notched
hammer rod hole 15. Furthermore, the cross-sectional shape of the rod hold
notch 15a may be
any shape, such as circular, oblong, angular, or any other shape known to
those skilled in the art.
Additionally, the cross-sectional shape of the rod hole notch 15a may vary
along its length.
As shown in FIGS. 5:7, the sides of the notched hammer neck 11 in first
embodiment of the
notched hammer 10 are parallel, and the notched hammer rod hole 15 is
surrounded by a notched
hammer first shoulder 14a. The notched hammer first shoulder 14a is comprised
of a raised,
single uniform ring surrounding the notched hammer rod hole 15. The notched
hammer first
shoulder 14a thereby increased the material thickness around the notched
hammer rod hole 15 as
compared to the thickness of the notched hammer first end 12. The notched
hammer first
shoulder 14a increases the surface area available for distribution of the
opposing forces placed on
the notched hammer rod hole 15 during operation in an amount proportional to
the width of the
hammer. This increase in surface area allows for a longer useful life of the
notched hammer 10
because the additional surface area works to decrease the amount of elongation
of the notched
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hammer rod hole 15 while still allowing the notched hammer 10 to swing freely
on the hammer
rod 8 during operation. Other embodiments of the notched hammer 10 may not be
configured
with a notched hammer first shoulder 14a, and in still other embodiments the
sides of the
notched hammer neck 11 may be oriented other than parallel to one another.
The first embodiment of the notched hammer 10 also includes a hardened contact
edge 20
welded on the periphery of the notched hammer second end 16. The hardened
contact edge 20 is
positioned on the portion of the notched hammer second end 16 that is most
often in contact with
the material to be comminuted during operation of the hammermill assembly 2.
The hardened
contact edge 20 may be comprised of any suitable material known to those
skilled in the art, and
it is contemplated that one such material is tungsten carbide. In other
embodiments of the
notched hammer 10 a hardened contact edge 20 is not positioned on the notched
hammer second
end 16.
A second embodiment of the notched hammer 10 is shown in FIG. 8. In the second
embodiment
the notched hammer neck 11 includes a plurality of neck voids 1 la. As shown
in FIG. 8, the
second embodiment includes two neck voids Ila that are both circular in shape
but have
different diameters from one another. The neck voids l la may have any shape,
and each neck
void 1 la may have a different shape than an adjacent neck void 1 la.
Furthermore, neck voids
11 a may have perimeters of differing values, and the neck voids l la need not
be positioned
along the center line of the notched hammer neck 11. More than two neck voids
lla may be used
in any the second embodiment of the notched hammer 10. The neck voids I la may
be
asymmetrical or symmetrical. As shown in FIG. 8, the circular nature of the
neck voids I la
allows the transmission and dissipation of the stresses produced at the
notched hammer first end
12 through and along the notched hammer neck 11.
The notched hammer neck 11 in the second embodiment is not as thick as the
notched hammer
first end 12 or the notched hammer second end 16. This configuration of the
notched hammer
neck 11 allows for reduction in the overall weight of the notched hammer 10,
to which attribute
the neck voids 1 la also contribute. The mechanical energy imparted to the
notched hammer
second end 16 with respect to the mechanical energy imparted to the notched
hammer neck 11 is
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= CA 2720159 2017-02-27
also increased with this configuration. The neck voids 1 la also allow for
greater agitation of the
= material to be comminuted during operation of the hammermill assembly 2.
A third embodiment of the notched hammer 10 is shown in FIG. 9. The notched
hammer rod
hole 15 in the third embodiment includes a notched hammer first shoulder I4a
and a notched
hammer second shoulder 14b oriented symmetrically around the notched hammer
rod hole 15.
As explained in detail above for the first embodiment of the notched hammer
10, the first and
second rod hole shoulders 14a, I4b allow the notched hammer rod hole 15 to
resist elongation. In
the third embodiment, the notched hammer second shoulder 14b is of a greater
axial dimension
than the notched hammer first shoulder 14a but of a lesser radial dimension,
and both the
notched hammer first and second shoulders 14a, 14b are symmetrical with
respect to the notched
hammer rod hole 15. This configuration increases the useful life of the
notched hammer 10 while
simultaneously allowing for decreased weight thereof since the portion of the
notched hammer
first end 12 not formed as either the notched hammer first or second shoulders
14a, 14b may be
of the same thickness as the notched hammer neck 11 and notched hammer second
end 16. The
third embodiment is also show with a hardened contact edge 20 welded to the
notched hammer
second end 16, but other embodiments exist that do not have a hardened contact
edge 20.
The edges of the notched hammer neck 11 in the third embodiment are non-
parallel with respect
to one another, and instead form an hourglass shape. This shape starts just
below the notched
hammer rod hole 1.5 and continues through the notched hammer neck 11 to the
notched hammer
second end 16. This hourglass shape yields a reduction in weight of the
notched hammer 10 and
also reduces the vibration of the notched hammer 10 during operation.
A forth embodiment of the notched hammer 10 is shown in FIG. 10, which most
related to the
second embodiment of the notched hammer 10 shown in FIG. 8. The fourth
embodiment does
not include neck voids 1 la. As shown, the fourth embodiment provides the
benefits of increasing
the surface area available for distribution of the opposing forces placed on
the notched hammer
rod hole 15 in proportion to the thickness of the notched hammer neck 11
without using a
notched hammer 'first or second shoulder 14a, 14b. As with some other
embodiments disclosed
and described herein, the fourth embodiment allows for decreased overall
notched hammer 10
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CA 2720159 2017-02-27
weight from the decreased thickness of notched hammer neck l 1 while
simultaneously reducing
the likelihood of elongation of the notched hammer rod hole 15.
A fifth embodiment of the notched hammer is shown in FIG. 11. In the fifth
embodiment, the
thickness of the notched hammer first end 12, notched hammer neck 11, and
notched hammer
second end 16 are substantially similar. A notched hammer first shoulder 14a
is positioned
around the periphery of the notched hammer rod hole 15 for additional strength
and to reduce
elongation thereof, as explained in detail above. Additionally, the fifth
embodiment includes a
hardened contact edge 20. The rounded shape of the notched hammer first end 12
strengthens the
notched hammer first end 12 by improving the transmission of hammer rod 8
vibrations away
from the notched hammer first end 12, through the notched hammer neck 11 to
the notched
hammer second end 16. The rounded shape also allows for overall weight
reduction of the
notched hammer 10. The edges of the notched hammer neck l 1 are parallel in
the fifth
embodiment, but they may also be curved to create an hourglass shape as
previously disclosed
for other embodiments.
A sixth embodiment of the notched hammer is shown in FIG. 12. In this
embodiment, notched
hammer first and second shoulders 14a, 14b are positioned around the periphery
of the notched
hammer rod hole 15 to prevent elongation thereof. As with the fifth
embodiment, the thickness
of the notched hammer first end 12, notched hammer neck 11, and notched hammer
second end
16 are substantially equal. The sixth embodiment also includes a hardened
contact edge 20, and
the edges of the notched hammer neck 11 are curved to improve vibration energy
transfer as
previously described for similar configurations.
A seventh embodiment of the notched hammer is shown in FIG. 13. The notched
hammer second
end 16 of the seventh embodiment includes a plurality of contact surfaces 22a,
24a, and 26a,
which increases the overall surface area available for contact with the
material to be
comminuted. The seventh embodiment includes a first, a second, and a third
contact surface 22a,
24a, and 26a, respectively, which results in four distinct contact points a
first, second, third,
and fourth contact points 22b, 24b, 26b, and 28.
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CA 2720159 2017-02-27
During operation, two of the three contact surfaces 22a, 24a, 26a are working,
depending on the
direction of rotation of the notched hammer 10. The notched hammer 10 may be
used bi-
directionally by either changing the direction of rotation of the hammermill
assembly 2 or by
removing the notched hammer 10 and reinstalling it facing the opposite
direction. For example,
during normal operation in a first direction of rotation, primarily the first
and second contact
surfaces 22a, 24a will contact the material to be comminuted, and the first
and second contact
points 22b, 24b will likely comprise the primary working areas. Accordingly,
the third contact
surface 26a will be the trailing surface so that the third and fourth contact
points 26b, 28 will
exhibit very little wear.
If the direction of rotation of the notched hammer 10 is reversed either by
reversing the direction
of rotation of the hammermill assembly 10 or be reinstalling each notched
hammer 10 in the
opposite orientation, primarily the second and third contact surfaces 24a, 26a
will contact the
material to be communicated, and the third and fourth contact points 26b, 28
will likely comprise
the primary working areas. Accordingly, the first contact surface 22a will be
the trailing surface
so that the first and second contact points 22b, 24b will likely exhibit very
little wear.
The first, second, and third contact surfaces 22a, 24a, 26a are symmetrical
with respect to the
notched hammer 10 in the seventh embodiment. In the seventh embodiment, the
linear distance
from the center of the notched hammer rod hole 15 to the first, second, third,
and fourth contact
points 22b, 24b, 26b, 28, respectively, is equal. However, in other
embodiments not pictured
herein those distances may be different, or the contact surfaces 22a, 24a,
26a, and/or the contact
points 22b, 24b, 26b, 28 may be different. In such embodiments the contact
surfaces 22a, 24a,
26a are not symmetrical. In still other embodiments not pictured herein, the
notched hammer 10
includes only two contact surfaces 22a, 24a, or more than three contact
surfaces. Accordingly,
the precise number of contact surfaces used in any embodiment of the notched
hammer 10 in no
way limits the scope of the notched hammer 10.
In the seventh embodiment, the thickness of the notched hammer first end 12,
notched hammer
neck 11, and notched hammer second end 16 is substantially equal. Furthermore,
a hardened
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CA 2720159 2017-02-27
contact edge 20 has been welded to the notched hammer second end 16 to cover
the first, second,
and third contact surfaces 22a, 24a, 26a.
An eighth embodiment of the notched hammer 10 is shown in FIG. 14. This
embodiment is
similar to the seventh embodiment in that notched hammer second end 16 of the
eighth
embodiment includes three distinct contact surfaces 22a, 24a, 26a, and four
distinct contact
points 22b, 24b, 26b, 28. However, the notched hammer second end 16 in the
eighth embodiment
also includes a plurality of edge pockets 29. Each edge pocket 29 is a cutaway
portion placed one
of the contact surfaces 22a, 24a, 26a. In the eighth embodiment two edge
pockets 29 are
positioned on the notched hammer second end 16 symmetrically about either side
of the second
contact surface 24a. In other embodiments, the edge pockets 29 are not
symmetrically positioned
on the notched hammer second end 16, and the number of edge pockets 29 in no
way limits the
scope of the notched hammer 10. The edge pockets allow temporary insertion of
"pocketing" of
the material to be comminuted during rotation of the hammermill assembly 2 to
increase loading
upon the contact surfaces 22a, 24a, 26a, and thereby increase the contact
efficiency between the
notched hammer 10 and the material to be comminuted.
The depth of each edge pocket 29 may be proportional to the difference between
the hammer
swing length and the distance from the center of the notched hammer rod hole
15 to the first and
third contact surfaces 22a, 26a. In many applications the depth of the edge
pocket 29 is from 0.25
to twice the thickness of the notched hammer first end 12. The shape of the
edge pocket 29 may
be rounded, as shown in FIG. 14, or it may be angular in embodiments not
pictured herein.
Furthermore, the edge pockets 29 may be tapered so that the thickness thereof
is not constant.
The eight embodiment includes a hardened contact edge 20. It also includes
notched hammer
first and second shoulders 14a, 14b, and the edges of the notched hammer neck
11 are curved so
that the notched hammer 10 is shaped similar to an hourglass.
A ninth embodiment of the notched hammer 10 is shown in FIG. 15. In this
embodiment, the
thickness of the notched hammer first end 12, notched hammer neck 1 I, and
notched hammer
second end 16 are substantially equal. The ninth embodiment includes notched
hammer first and
second shoulders 14a, 14b positioned around the periphery of the notched
hammer rod hole 15.
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= CA 2720159 2017-02-27
However, unlike other embodiments previously described and disclosed herein,
the notched
hammer first and second shoulders 14a, 146 in the ninth embodiment are not
symmetrical with
respect to the notched hammer rod hole 15. This allows for overall weight and
material reduction
of the notched hammer 10 while still providing the benefits of reinforcement
around the
periphery of the notched hammer rod hole 15 provided by notched hammer
shoulders 14a, 14b as
previously described in detail. The ninth embodiment also includes a hardened
contact edge 20,
and the edges of the notched hammer neck 11 are curved.
The various features and or elements that differentiate one embodiment of the
notched hammer
from another embodiment may be added or removed from various other embodiments
to
result in a nearly infinite number of embodiments. Whether shown in the
various figures herein,
all embodiments may include a notched hammer first shoulder 14a alone or in
combination with
a notched hammer second shoulder 14a having an infinite number of
configurations, which may
or may not be symmetrical with one another and/or the notched hammer rod hole
15.
Furthermore, any embodiment may have notched hammer first and/or second
shoulders 14a, 14b
on both sides of the notched hammer 10.
Other features/configurations that may be included on any embodiments alone or
in combination
include: (1) curved or straight edges on the notched hammer neck 11; (2)
reduced thickness of
the notched hammer neck 11 with respect to the notched hammer first end 12
and/or notched
hammer second end 16; (3) curved or angular notched hammer first ends 12; (4)
hardened
contact edges 20; (5) neck voids Ila; (6) multiple contact points; (7)
multiple contact surfaces;
(8) edge pockets 29; and, (9) multiple blades, which is described in detail
below, or any
combinations thereof. Furthermore, any embodiment may be bidirectional. Any
embodiment of
the notched hammer 10 may be heat treated if such heat treatment will impart
desirable
characteristics to the notched hammer 10 for the particular application.
In embodiments of the notched hammer 10 having a notched hammer neck 11 that
is reduced in
width (i.e., wherein the edges are curved) or thickness, it is contemplated
that the notched
hammer 10 will be manufactured by forging the steel used to produce the
notched hammer 10.
This is because forging typically in a finer grain structure that is much
stronger than casting the
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CA 2720159 2017-02-27
=
notched hammer 10 from steel or rolling it from bar stock as found in the
prior art. However, the
notched hammer 10 is not so limited by the method of construction, and any
method of
construction known to those of ordinary skill in the art may be used including
casting, rolling,
stamping, machining, and welding.
Another benefit of some of the embodiments of the notched hammer 10 is that
the amount of
surface area supporting attachment of the notched hammer 10 to the hammer rod
8 is
dramatically increased. This eliminates or reduces the wear or grooving of the
hammer rod 8
caused by rotation of the notched hammer 10 during use. The ratio of surface
area available to
support the notched hammer 10 to the weight and/or overall thickness of the
notched hammer 10
may be optimized with less material using various embodiments disclosed
herein. Increasing the
surface area available to support the notched hammer l 0 on the hammer rod 8
while improving
securement of the notched hammer 10 to the hammer rod 8 also increases the
amount of material
in the notched hammer 10 available to absorb or distribute operational
stresses while still
providing the benefits of the free-swinging hammer design (i.e., recoil to non-
destructible
foreign objects).
Embodiments of the notched hammer 10 having only a notched hammer first
shoulder 14a or
notched hammer first and second shoulders 14a, 14b (oriented either non-
symmetrical with
respect to the notched hammer rod hole 15, such as the ninth embodiment shown
in FIG. 15 or
symmetrical, such as the third, sixth, or eighth embodiments, shown in FIGS.
9, 12, and 14,
respectively) may be especially useful with the rod hole notch I5a. In such
embodiments it is
contemplated that the thickness of the notched hammer first and second
shoulders 14a, 14b will
be 0.5 inches or greater, but may be less for other embodiments.
It should be noted that the present invention is not limited to the specific
embodiments pictured
and described herein, but is intended to apply to all similar apparatuses for
improving
hammermill hammer structure and operation. Modifications and alterations from
the described
embodiments will occur to those skilled in the art without departure from the
scope of the notched
hammer 10.
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CA 2720159 2017-02-27
3. Illustrative Embodiments of Multiple Blade Hammer
Several exemplary embodiments of a multiple blade hammer 30 will now be
described. The
preferred embodiment will vary depending on the particular application for the
multiple blade
hammer 30, and the exemplary embodiments described and disclosed herein
represent just some
of an infinite number of variations to the multiple blade hammer 30 that will
naturally occur to
those skilled in the art.
A perspective view of a first embodiment of a multiple blade hammer 30 is
shown in FIG. 16.
The first embodiment is a metallic-based multiple blade hammer 30 for use in a
rotatable
hammermill assembly 2 as shown in FIGS. 1-3. Other embodiments of the multiple
blade
hammer 30 for use with types of hammermill assemblies other than that shown
and described
herein are included within the scope of the multiple blade hammer 30.
The multiple blade hammer 30 includes a multiple blade hammer first end 32 and
a multiple
blade hammer second end 36, which are connected to one another via a multiple
blade hammer
neck 11. The multiple blade hammer 30 in the first embodiment includes a
multiple blade
hammer rod hole 35 formed in the multiple blade hammer first end 32. Multiple
blade hammer
first and second shoulders 34a, 34b both surround the multiple blade hammer
rod hold 35, which
is shown most clearly in FIGS. 16 and 17. In this respect, the multiple blade
hammer first end 32
is configured in a very similar manner to the notched hammer first end 12 in
the ninth
embodiment thereof, which is shown in FIG. 15. Accordingly, the multiple blade
hammer first
and second shoulders 34a, 34b in the first embodiment of the multiple blade
hammer 30 are not
symmetrical with respect to the multiple blade hammer rod hole 35.
In other embodiments of the multiple blade hammer 30 not pictured herein, the
multiple blade
hammer first and second shoulders 34a, 34b may be symmetrical with respect to
the multiple
blade hammer rod hole 35. In such embodiments of the multiple blade hammer 30,
the multiple
blade hammer first end 32 would be configured in a manner similar to the
notched hammer first
end 12 in the third embodiment thereof, which is shown in FIG. 9. In other
embodiment of the
multiple blade hammer 30 not pictured herein, only a first multiple blade
hammer shoulder 34a
may surround the multiple blade hanuner rod hole 35. In such embodiments of
the multiple blade
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CA 2720159 2017-02-27
hammer 30, the multiple blade hammer first end 32 would be configured in a
manner similar to
the notched hammer first end 12 in the first embodiment thereof, which is
shown in FIG. 5. In
still other embodiments of the multiple blade hammer 30 not pictured herein,
the multiple blade
hammer neck 31 is reduced in thickness compared to the thickness of the
multiple blade hammer
first end 32. In such embodiments of the multiple blade hammer 30, the
multiple blade hammer
first end 32 would be configured in a manner similar to the notched hammer
first end 12 in the
second embodiment thereof, which is shown in FIG. 8. Accordingly, it will
become apparent to
those skilled in the art in light of the present disclosure that the multiple
blade hammer first end
32 may include a multiple blade hammer first shoulder 34a and/or a multiple
blade hammer
second shoulder 34b, both of which may be in any configuration/orientation
disclosed for the
notched hammer 10.
The multiple blade hammer second end 36, which is the contact end, in the
first embodiment
includes a first, second, and third blade 37a, 37b, 37c, These three blades
37a, 37b, 37c provide
for three distinct contact surfaces in the axial direction, which is best seen
in FIG. 16. The
multiple blade hammer second end 36 provides for contact and delivery of
momentum to
material to be comminuted. The multiple blade hammer second end 36 includes at
least two
blades 37a, 37b, and in the first embodiment pictured herein includes three
blades 37a, 37b, 37c.
Accordingly, the multiple blade hammer 30 may be configured with two or more
blades 37a,
37b, 37c depending on the particular application, and the scope of the
multiple blade hammer 30
extends to any hammer having two or more blades 37a, 37b, 37c. The at least
two blades 4 have
combined width greater than the width of the multiple blade hammer first end
32, The distance
between the blades 37a, 37b, 37c will vary depending on the specific
application of the multiple
blade hammer 30, and in the first embodiment the distance between the blades
37a, 37b, 37c is
approximately equal to the thickness of the blades 37a, 37b, 37c, which is
approximately one-
fourth of an inch. However, the particular dimensions and/or orientation of
the blades 37a, 37b,
37c is in no way limiting.
In other embodiments not pictured herein, the multiple blade hammer 30
structure may undergo
further manufacturing work and have tungsten carbide welded to the periphery
of each of the
hammer blades 37a, 37b, 37c for increased hardness and abrasion resistance.
Furthermore, the
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CA 2720159 2017-02-27
=
=
multiple blade hammer first end 32, second end 36, and neck 31 may be heat-
treated for
hardness. It is contemplated that in many embodiments of the multiple blade
hammer 30 it will
be beneficial to construct the multiple blade hammer 30 using forging
techniques. However, the
scope of the multiple blade hammer 30 is not so limited, and other methods of
construction
known to those of ordinary skill in the art may be used including casting,
machining and
welding.
In other embodiments of the multiple blade hammer 30 not pictured herein, the
multiple blade
hammer 30 may have neck voids 1 la placed in the multiple blade hammer neck
31. In still other
embodiments of the multiple blade hammer 30 not pictured herein, the thickness
of the multiple
b-lade hammer neck 31 may be less than the thickness of either the multiple
blade hammer first
end 32 or second end 36. In such embodiments of the multiple blade hammer 30,
the multiple
blade hammer first end 32 and neck 31 would be configured substantially
similar to the notched
hammer first end 12 and 11 in the fourth embodiment thereof, which is shown in
FIG. 10.
In still other embodiments of the multiple blade hammer 30 not pictured
herein, each blade 37a,
37b, 37c may be configured to have more than one distinct contact point. In
such embodiments
of the multiple blade hammer 30, each blade 37a, 37b, 37c would be configured
substantially
similar to the notched hammer second end 16 in the seventh embodiment thereof,
which is
shown in FIG. 13. Edge pockets 29 may be positioned in any of the blades 37a,
37b, 37c in
variations of such embodiments, the configuration of which is not limiting to
the scope of the
multiple blade hammer 30 in any way, and may vary in a manner previously
explained for the
eighth embodiment of the notched hammer 10.
A second embodiment of the multiple blade hammer 30 is shown in FIG. 18. In
the second
embodiment the multiple blade hammer rod hole 35 is formed with at least one
rod hole notch 15
The at feast one rod hole notch 15a transverses the length of the multiple
blade hammer rod hole
35 and is aligned with the multiple blade hammer neck 31. As shown in FIG. 18,
the longitudinal
axis of the rod hole notch 15a is parallel with the longitudinal axis of the
multiple blade hammer
rod hole 35, but may have different orientations in embodiments not pictured
or described herein,
such as an embodiment wherein the rod hole notch 15a is not parallel to the
longitudinal axis of
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______ ¨ ¨ ¨
,
= CA 2720159 2017-02-27
the multiple blade hammer rod hole 15. Furthermore, the cross-sectional shape
of the rod hold
notch 15a may be any shape, such as circular, oblong, angular, or any other
shape known to
those skilled in the art. Additionally, the cross-sectional shape of the rod
hole notch 15a may
vary along its length.
The various features and or elements that differentiate one embodiment of the
multiple blade
hammer 30 from another embodiment may be added or removed from various other
embodiments to result in a nearly infinite number of embodiments. Whether
shown in the
various figures herein, all embodiments may include a multiple blade hammer
first shoulder 34a
alone or in combination with a multiple blade hammer second shoulder 34a
having an infinite
number of configurations, which may or may not be symmetrical with one another
and/or the
multiple blade hammer rod hole 35. Furthermore, any embodiment may have
multiple blade
hammer first and/or second shoulders 34a, 34b on both sides of the multiple
blade hammer 30.
Other features/configurations that may be included on any embodiments alone or
in combination
include: (1) curved or straight edges on the multiple blade hammer neck 31;
(2) reduced
thickness of the multiple blade hammer neck 31 with respect to the multiple
blade hammer first
end 32 and/or any blades 37a, 37b, 37c; (3) curved or angular multiple blade
hammer first ends
32; (4) hardened contact edges 20 positioned on and/or adjacent to the blade
edges 38; (5) neck
voids Ila; (6) multiple contact points on any blade 37a, 37b, 37c; (7)
multiple contact surfaces;
(8) edge pockets 29; and, (9) multiple blades 37a, 37b, 37c, which is
described in detail below, or
any combinations thereof. Furthermore, any embodiment may be bidirectional.
Any embodiment
of the multiple blade hammer 30 may be heat treated if such heat treatment
will impart desirable
characteristics to the multiple blade hammer 30 for the particular
application.
In embodiments of the multiple blade hammer 30 having a multiple blade hammer
neck 31 that
is reduced in width wherein the edges are curved) or thickness, it is
contemplated that the
multiple blade hammer 30 will be manufactured by forging the steel used to
produce the multiple
blade hammer 30. This is because forging typically in a finer grain structure
that is much
stronger than casting the multiple blade hammer 30 from steel or rolling it
from bar stock as
found in the prior art. However, the multiple blade hammer 30 is not so
limited by the method of
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CA 2720159 2017-02-27
construction, and any method of construction known to those of ordinary skill
in the art may be
used including casting, rolling, stamping, machining, and welding.
Another benefit of some of the embodiments of the multiple blade hammer 30 is
that the amount
of surface area supporting attachment of the multiple blade hammer 30 to the
hammer rod 8 is
dramatically increased. This eliminates or reduces the wear or grooving of the
hammer rod 8
caused by rotation of the multiple blade hammer 30 during use. The ratio of
surface area
available to support the multiple blade hammer 30 to the weight and/or overall
thickness of the
multiple blade hammer 30 may be optimized with less material using various
embodiments
disclosed herein. Increasing the surface area available to support the
multiple blade hammer 30
on the hammer rod 8 while improving securement of the multiple blade hammer 30
to the
hammer rod 8 also increases the amount of material in the multiple blade
hammer 30 available to
absorb or distribute operational stresses while still providing the benefits
of the free-swinging
hammer design (i.e., recoil to non-destructible foreign objects).
Embodiments of the multiple blade hammer 30 having only a multiple blade
hammer first
shoulder 34a or multiple blade hammer first and second shoulders 34a, 34b
(oriented either non-
symmetrical with respect to the multiple blade hammer rod hole 35 or
symmetrical) may be
especially useful with the rod hole notch 15a. In such embodiments it is
contemplated that the
thickness of the multiple blade hammer first and second shoulders 34a, 34b
will be 0.5 inches or
greater, but may be less for other embodiments.
It should be noted that the present invention is not limited to the specific
embodiments pictured
and described herein, but is intended to apply to all similar apparatuses for
improving
hammermill hammer structure and operation. Modifications and alterations from
the described
embodiments will occur to those skilled in the art without departure from the
scope of
the multiple blade hammer 30.
4. Illustrative Embodiments of Dual-Blade Hammer
Referring now to the drawings, wherein like reference numerals designate
identical or
corresponding parts throughout the several views, FIG. 19 provides a
perspective view of one
Page 26
CA 2720159 2017-02-27
embodiment the dual-blade hammer 110. The embodiment of the dual-blade hammer
110
pictured herein includes a connector end 120, a contact end 140, and a neck
130 positioned
between the connector end 120 and contact end 140.1n the embodiment pictured
herein, the neck
first end 132 is affixed to the connector end 120 and the neck second end 134
is affixed to the
contact end 140.
The connector end 120 in the embodiment pictured herein is formed with a rod
hole 122
therethrough. The rod hole 122 may be formed with a notch 126 therein as well,
as best shown in
FIG. 20. The rod hole 122 serves to pivotally attach the dual-blade hammer 110
to a hammer pin
or rod (neither shown) of a hammermill assembly. Hammer pins and rods used in
hammermill
assemblies and their operation are not further described herein for purposes
of clarity, but are
well known to those skilled in the art.
The connector end 120 may also include a first shoulder 124a positioned around
the periphery of
the rod hole 122. The notch 126 may protrude into the first shoulder 124a, as
shown in the
embodiment of the dual-blade hammer 110 pictured in FIGS. 19 and 20. A second
shoulder 124b
may also be positioned around a portion of the periphery of the first shoulder
124a. In the
embodiment pictured herein, the second shoulder 124b encompasses approximately
one-half of
the periphery of the first shoulder and is positioned opposite the area of the
first shoulder 124a in
which the notch 126 is formed.
As shown herein, the first shoulder 124a is not generally circular in shape,
but rather it is
generally triangular in shape with a rounded vertex adjacent the notch 126,
and the thicknesses of
the first and second shoulders 124a, 124b are approximately equal. This
configuration allows for
discrepancies in the location of the rod hole 122 to account for machining
differences within the
hammermill. That is, the precise location of the rod hole 122 and notch 126
may be adjusted by a
predetermined amount along the length of the connector end 120 to adjust the
swing length of the
dual-blade hammer 110. That is, an area exists in the connector end 120 in
which the rod hole
1 22 may be positioned such that the rod hole 122 is within the periphery of
the first and second
shoulders 124a, 124b. In such a case, the dual blade hammer 110 would be
formed without a rod
hole 122, and the rod hole 122 would be added just prior to installation in a
hammermill so that
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CA 2720159 2017-02-27
the swing length of the dual-blade hammer 110 could be precisely set. The area
in which the rod
hole 122 could be formed may have a different size in one embodiment of the
dual-blade
hammer 110 to the next, and the amount of swing-length adjustment will also
depend on the size
of the rod hole 122. However, it is contemplated that the most critical
dimension of this area will
be along the length of the dual-blade hammer 110, and the amount of adjustment
in that
dimension may be as small or as large as required by the tolerances of the
hammermill, and is
therefore in no way limiting to the scope of the dual-blade hammer 110.
In the pictured embodiment of the dual-blade hammer 110, a line of symmetry
exists along the
length of the dual-blade hammer from the view shown in FIG. 20. This line of
symmetry bisects
the rod hole 122 and notch 126, and passes through the vertex of the first
shoulder 124a. In other
embodiments not pictured herein, the first shoulder 124a may extend further
down the neck 130
than it does in the illustrative embodiment, allowing even more adjustment in
the swing length of
the dual-blade hammer 110. Alternatively, the first shoulder 124a may be
generally semi-circular
in shape, such as in the notched hammer first shoulder 14a shown in FIG. 15.
Accordingly, the
specific shape and/or configuration of the first shoulder 124a and/or second
shoulder 124b in no
way limit the scope of the dual-blade hammer 110 as disclosed and claimed
herein.
The first and/or second shoulders 124a, 124b provide increased strength and
longevity to the
dual-blade hammer 110 in many applications, as is well known to those skilled
in the art. In the
embodiment pictured herein, both the first and second shoulders 124a, 124b are
positioned on
both sides of the rod hole 122, which is best shown in FIG. 21. However, in
other embodiments
not pictured herein, either the first or second shoulder 124a, 124b may be
positioned on only one
side of the rod hole 122. The optimal dimensions of both the first and second
shoulders 124a,
124b will vary depending on the specific application of the dual-blade hammer
110, and are
therefore in no way limiting to the scope of the dual-blade hammer 110. In the
embodiment
pictured herein, the thickness of both the first and second shoulders J24a,
J24b is 0.75 inches.
In the embodiments pictured herein, the connector end 120 is rounded, as best
shown in FIGS.
19, 20, and 22. In the embodiment of the dual-blade hammer 110 pictured
herein, the outer
diameter of the connector end is 2.5 inches. However, in other embodiments not
pictured herein,
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CA 2720159 2017-02-27
the connector end 120 may have other shapes, such as rectangular, triangular,
elliptical, or
otherwise without departing from the scope of the dual-blade hammer 110 as
disclosed
herein. Furthermore, the relative dimensions and angles of the various
elements of the dual-blade
hammer 110 may be adjusted for the specific application of the dual-blade
hammer 110, and
therefore an infinite number of variations of the dual-blade hammer 110 exist,
and such
variations will naturally occur to those skilled in the art without departing
from the scope of
the dual-blade hammer 110.
As best shown in FIG. 20, the neck edges 138 of the embodiment of the dual-
blade hammer 110
pictured herein are non-linear. In the embodiment pictured herein, curvature
of both neck edges
138 is derived from a circle having a radius of eighteen inches. However, the
precise orientation
and/or configuration of the neck edges 138 are in no way limiting in scope.
Accordingly, in other
embodiments of the dual-blade hammer 110 not pictured herein the neck edges
138 may be
linear. The optimal width, curvature, and configuration of the neck 30 will
vary depending on the
specific application of the dual-blade hammer 110, which may depend on the
type of material to
be comminuted.
The neck 130 of the dual-blade hammer 110 includes at least one neck recess
136, which is best
shown in FIGS. 19, 20, and 22. The neck recess 136 in the embodiment pictured
herein is
generally rectangular in shape with rounded corners, but may have other shapes
in other
embodiments not shown herein. The curved portions of the neck recess 136
pictured herein are
derived from circles having radii of three and one-half inches, which may be
more or less in
other embodiments not pictured herein. One or more neck recesses 136 may be
formed in each
side of the neck 130, and the optimal number, orientation, and configuration
of neck recesses 136
will depend on the specific application of the dual-blade hammer 110. In the
embodiment
pictured herein, the dual-blade hammer 110 includes two identical neck
recesses 136
symmetrically (with respect to the orientation shown in FIG. 21) positioned on
each side of the
neck 130.
In the embodiment pictured herein, each neck recess 136 protrudes into the
neck 130 by 0.075
inches, such that the width of the neck 130 between the two neck recesses 136
is 0.1 inch.
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CA 2720159 2017-02-27
Accordingly, the thickness of the neck 130 at a position thereof in which no
neck recesses 136
protrude is 0.25 inches. However, the dimensions of the neck 130, including
the thickness
thereof adjacent to neck recesses 136, and the dimensions, configuration,
and/or placement of
neck recesses 136 is in no way limiting to the scope of the dual-blade hammer
110. The dual-
blade hammer 110 may have any number of neck recesses 136 (e.g., a single neck
recess 136 on
one side of the neck 130, multiple neck recesses 136 on one side of the neck
130, multiple
recesses 136 on both sides of the neck 130, etc.). Furthermore, the neck
recesses 136 may have
any shape without departing from the scope of the dual-blade hammer 110 as
disclosed
and claimed herein. In other embodiments of the dual-blade hammer 110 not
pictured herein the
neck recess(s) 136 may extend through the neck 130. In such embodiments, the
neck recess(s)
136 would appear as voids positioned in the neck 130. Several such embodiments
of such voids
are disclosed in U.S. Pat. No. 7,559,497 .
The neck second end 134 is affixed to the contact end 140. The contact end
140, which delivers
energy to the material to be comminuted, may have an infinite number of
configurations, the
optimal of which will depend on the particular application of the dual-blade
hammer 110. For
example in embodiments not pictured herein, the contact end 140 may be
comprised of a single
contact surface with multiple contact points, or it may be configured with
multiple contact
surfaces having multiple contact points. Certain embodiments of the contact
end 140 that may be
included with the dual-blade hammer 10 are disclosed in U.S. Pat. App. No.
12/398,007.
In the embodiment pictured herein, the contact end 140 is formed with a first
contact surface
142a and a second contact surface 142b, wherein the two contact surfaces 142a,
142b are
separated from one another by an interstitial area 144. Other embodiments of
the dual-blade
hammer 110 may include a weld-hardened edge on one or more of the contact
surfaces 142a,
142b. In the embodiment of the dual-blade hammer 110 pictured herein, the
width of the contact
end 140 is two inches, and the overall thickness of the contact end is 0.75
inches. The thickness
of the interstitial area 144 is 0.1 inches. However, as stated above, the
contact end 140 may take
on any orientation and/or configuration without departing from the scope of
the dual-
blade hammer 110 as disclosed and claimed herein.
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,
CA 2720159 2017-02-27
The materials used to construct the connector end 120, first or second
shoulder 124a, 124b, neck
130, and contact end 140 will vary depending on the specific application for
the dual-blade
hammer 110. Certain applications will require a high tensile strength
material, such as steel,
while others may require different materials, such as carbide-containing
alloys. Accordingly, the
above-referenced elements may be constructed of any material known to those
skilled in the art,
which material is appropriate for the specific application of the dual-blade
hammer 110, without
departing from the scope thereof.
Other methods of using the dual-blade hammer 110 and embodiments thereof will
become
apparent to those skilled in the art in light of the present disclosure.
Accordingly, the methods
and embodiments pictured and described herein are for illustrative purposes
only. The dual-blade
hammer 110 also may be used in other manners, and therefore the specific
hammermill in which
the dual-blade hammer 110 is used in no way limits the scope of the dual-blade
hammer 110.
It should be noted that the dual-blade hammer 110 is not limited to the
specific embodiments
pictured and described herein, but is intended to apply to all similar
apparatuses for reducing the
weight of a communiting instrument while retaining the strength thereof.
Modifications and
alterations from the described embodiments will occur to those skilled in the
art without
departure from the scope of the dual-blade hammer 110.
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