Solid material comminution or disintegration – Apparatus – Comminuting elements
Reexamination Certificate
1999-03-25
2001-02-20
Husar, John M. (Department: 3725)
Solid material comminution or disintegration
Apparatus
Comminuting elements
C241S298000, C241S300000
Reexamination Certificate
active
06189821
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention is in the field of grinders and pulverizers. More specifically, the present invention provides grinders which reduce the size of plastic and other polymeric particles through circular shaped grinding rings. The present invention further provides an apparatus that reduces the time required replacing worn blade segments, and increases grinding or pulverizing efficiency.
BACKGROUND OF THE INVENTION
Many industrial applications require the grinding and pulverizing of plastic and other polymeric components. A common grinding machine utilizes a circular shaped drive ring, commonly about two feet in diameter, orientated substantially in the plane which is perpendicular to the ground, and which is attached to a motor-driven rotatable shaft. The drive ring has attached to it numerous blade segments, usually a total of between 14 and 60, and each blade segment contains a plurality of blades. In the grinding machines in current use, the segments are attached to the drive ring using at least one direct fastener, such as a bolt. Usually the blade segments are attached using two bolts.
Bolting the blade segments to the drive ring provides a secure connection during the grinding or pulverizing process, but this connection mechanism causes production inefficiency and other problems. When blades are worn, the operator must replace the blade segments. It takes extensive time to replace the blade segments, because each segment must be unbolted and, after sharpening or replacement, re-bolted to the drive ring. Even with automated equipment for removing and installing the bolts, the exchange process can require 4 to 6 hours to complete. Extensive replacement time results in the manufacturer losing machine operation time, or having to invest in a redundant drive ring-blade segment set. This poses a problem to the industrial plastic grinder or pulverizer, because many cannot afford to purchase duplicate drive ring sets for immediate replacement or afford to pay for machine operators to replace blade segments.
Additionally, worn blade segments are sharpened by re-cutting groves into the surface of the blade segment. The bolting mechanism requires that the blade segments contain threaded longitudinal grooves. Threaded grooves require a minimum thickness in the blade segments and, therefore, reduce the width of the blade segment available for resharpening.
A solution to this problem was attempted by eliminating the bolt attachment, and fixing blade segments in place using pressure or clamping, such as disclosed in U.S. Pat. No. 3,941,319. This approach does not provide a complete solution because it relies on clamping or overt pressure to fix the blade segments in place. This approach resulted in additional components that impede the grinding or pulverizing process and, in some cases, failed to adequately fix the blade segments in place.
SUMMARY OF THE INVENTION
The present invention is an apparatus for grinding polymeric materials comprising (a) a drive ring receivable onto a rotatable shaft and having (i) a first flat surface, (ii) a second flat surface; wherein the first flat surface is orientated in a first plane, the second flat surface is orientated in a second plane, and the first flat surface plane is separate from the second flat surface plane; and wherein the drive ring defines a recess adjacent to the drive ring first flat surface and defined by (i) an inner wall orientated in a plane, (ii) an outer wall oriented in a plane and (iii) an interior flat surface oriented in a plane and which comprises an inner edge and an outer edge wherein (A) the inner edge of the interior flat surface is connected to the inner wall, and (B) the outer edge of the interior flat surface is connected to the outer wall; (b) a plurality of blade segments forming a plane; (c) an adapter ring which is substantially the same size and shape as the drive ring recess, forming a plane, (d) a means for connecting the blade segments to the adapter ring whereby, (i) the blade segments received into the adapter ring are precluded from moving in a plane which is substantially perpendicular to the plane of the adapter ring and blade segment combination and (ii) the blade segments freely move in the plane which is substantially the same as the plane of the adapter ring and blade segment combination; and (e) a means for connecting the adapter ring to the drive ring, wherein (i) the adapter ring connected to the drive ring is insertable into and maintained in the drive ring recess and (ii) the blade segments received into the adapter ring which is connected to the drive ring are precluded from moving in the plane which is substantially the same as the plane of the adapter ring and blade segment combination.
In an embodiment of the present invention, the means for laterally receiving blade segments into the adapter ring is selected from the group consisting of (a) a plurality of tongue and groove fittings, (b) a plurality of dove-tail shaped fittings and (c) a plurality of inverted “T” shaped fittings. In the preferred embodiment of the present invention, the dovetail shaped fitting angle of incidence is about 60 degrees. In one embodiment of the present invention, the dovetail shaped fitting has a male section and a female section, wherein the male section of the dovetail is connected to the blade segment and the female section of the dovetail is connected to the adapter ring. In another embodiment of the present invention, the dovetail shaped fitting has a male section and a female section, wherein the male section of the dovetail is connected to the adapter ring and the female section of the dovetail is connected to the blade segment.
In another embodiment of the present invention, the drive ring is substantially circular-shaped, the drive ring recess is substantially ring-shaped and the adapter ring is substantially ring-shaped.
In another embodiment of the present invention, the drive ring further defines a plurality of holes in the drive ring recess. In the preferred embodiment of the present invention, the drive ring further defines about 120 holes in the drive ring recess.
In another embodiment of the present invention, the means for connecting the adapter ring to the drive ring comprises (a) at least one flange tab connected to the outer edge of the adapter ring wherein the flange tab is adapted to receive a fastener therein; and (b) at least one hole in the drive ring, wherein the hole is positioned opposite the flange tab and the hole is adaptable to receive a faster therein. In the preferred embodiment, the present invention comprises 8 flange tabs and corresponding drive ring holes.
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patent: 5348064 (1994-09-01), Nettles et al.
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Davis , Wright, Tremaine, LLP
Husar John M.
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