US4586658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impact grinding method and apparatus
Assignee: Individual
•
Filing: 1984-10-05
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Granted: 1986-05-06
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Expires: 2004-10-05
Abstract
Abstract For impact grinding a free-flowing feed material to a finished product of a narrow grain size range, particularly in the cereal and feeding stuff grinding industry, the feed material is fed to an impact or hammer mill (1) having a sieve jacket (33), wherein it is subjected to a first impact grinding phase, during which a first finished product passes through the sieve jacket (33), while a recirculation material component is withdrawn from the grinding chamber (34) through exhaust means (51) provided on the sieve jacket (33), said recirculation material component being fed to a grain size separator means (4) comprising a sieve screen (44) for separating further finished product from an oversize component which is to be returned to the impact grinding phase, preferably together with newly introduced feed material.
Inventors
- 👤 Edwin Eisenegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:16
CPC Classifications
B; B02; B02C; B02C13/00; B02C13/13
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
205 words
A method for impact grinding granular material to a finished product of a predetermined relatively narrow grain size range and to prevent the formation of excessive undersize material wherein a first sieve means is provided extending substantially entirely over a grinding path between a material feed station and a material receiving post-feed station, and a second sieve means is provided apart from the grinding path, said method comprising the steps of: introducing material to be ground to said grinding path and impact grinding said material to grain size in said grain size range and passing at least some of said ground material in said grain size range through said first sieve means; withdrawing at least part of said material not passed through said first sieve means from said grinding path at a predetermined point on said grinding path without allowing any of said withdrawn material to reenter said grinding path; introducing all of said withdrawn material to the second sieve means for separating oversize material relative to said grain size range from finer material; conveying said finer material to said post-feed station without passing through said grinding path; and reintroducing said oversize material to said grinding path to be ground to said grain size range.
Claim 2
Independent Claim
205 words
A method for impact grinding granular material to a finished product of a predetermined relatively narrow grain size range and to prevent the formation of excessive undersize material wherein a first sieve means is provided extending substantially entirely over a grinding path between a material feed station and a material receiving post-feed station, and a second sieve means is provided apart from the grinding path, said method comprising the steps of: introducing material to be ground to said grinding path and impact grinding said material to grain size in said grain size range and passing at least some of said ground material in said grain size range through said first sieve means; withdrawing at least part of said material not passed through said first sieve means from said grinding path at a predetermined point on said grinding path without allowing any of said withdrawn material to reenter said grinding path; introducing all of said withdrawn material to the second sieve means for separating oversize material relative to said grain size range from finer material; conveying said finer material to said post-feed station without passing through said grinding path; and reintroducing said oversize material to said grinding path to be ground to said grain size range.
Claim 3
Dependent Claim
34 words
The grinding method set forth in claim 1 wherein: said separation process is carried out by passing said withdrawn material through a second sieve means to separate said oversize material from said finer material.
Claim 4
Dependent Claim
37 words
The grinding method set forth in claim 1 including the step of: pneumatically conveying material which has not passed through said first sieve means from said grinding path to a point for carrying out said separation process.
Claim 5
Dependent Claim
61 words
The grinding method set forth in claim 3 wherein: said first sieve means is configured to form an interior grinding chamber into which material is introduced for impact grinding, and pressure air is generated in said grinding chamber for pneumatically conveying said material which has not passed through said first sieve means to a point for carrying out said separation process.
Claim 6
Dependent Claim
25 words
The grinding method set forth in claim 1 including the step of: subjecting said material passed through said first sieve means to said separation process.
Claim 7
Dependent Claim
43 words
The grinding method set forth in claim 5 including the steps of: providing bucket elevator means, and conveying said material which has passed through said first sieve means with said material withdrawn from impact grinding to means for carrying out said separation process.
Claim 8
Dependent Claim
26 words
The grinding method set forth in claim 5 including the step of: withdrawing material from said grinding path at plural predetermined locations along said grinding path.
Claim 9
Dependent Claim
28 words
The grinding method set forth in claim 5 including the step of: metering the amount of material withdrawn from said impact grinding and conveyed to said separation process.
Claim 10
Dependent Claim
216 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber for conducting said withdrawn material away from said grinding chamber without allowing any of said withdrawn material to reenter said grinding chamber prior to reaching a separator means, said separator means in communication with said discharge duct for receiving all of said material withdrawn from said grinding chamber and for separating oversize material from finer material in said grain size range, said separator means including a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and a second outlet for discharging said finer material to said discharge means.
Claim 11
Dependent Claim
216 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber for conducting said withdrawn material away from said grinding chamber without allowing any of said withdrawn material to reenter said grinding chamber prior to reaching a separator means, said separator means in communication with said discharge duct for receiving all of said material withdrawn from said grinding chamber and for separating oversize material from finer material in said grain size range, said separator means including a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and a second outlet for discharging said finer material to said discharge means.
Claim 12
Dependent Claim
53 words
The impact grinding apparatus set forth in claim 9 wherein: said feed means opens centrally into said grinding chamber for introducing said material to said grinding chamber adjacent an end surface of said sieve jacket and in a substantially axial direction with respect to an axis of rotation of said impact tool means.
Claim 13
Dependent Claim
47 words
The impact grinding apparatus set forth in claim 9 wherein: said feed means opend radially into said grinding chamber through said sieve jacket for feeding material to said grinding chamber in a substantially radial direction with respect to an axis of rotation of said impact tool means.
Claim 14
Dependent Claim
38 words
The impact grinding apparatus set forth in claim 9 wherein: said discharge means for material which has passed through said sieve jacket and which has been separated from oversize material in said separator means includes pneumatic conveying means.
Claim 15
Dependent Claim
43 words
The impact grinding apparatus set forth in claim 9 wherein: said apparatus includes a rotor carrying said impact tool means and including blower means for generating pressure air for pneumatic conveying of said material withdrawn from said grinding chamber to said separator means.
Claim 16
Dependent Claim
49 words
The impact grinding apparatus set forth in claim 9 wherein: said separator means includes sieve means and a cyclone separator and said discharge duct opens into said cyclone separator for separating material from conveying air prior to introduction of said material to said sieve means of said separator means.
Claim 17
Dependent Claim
51 words
The impact grinding apparatus set forth in claim 14 wherein: said discharge duct includes conveyor means located between a third outlet and said separator means, said third outlet being adapted to have material which has passed through said sieve jacket as well as material withdrawn from said grinding chamber fed thereto.
Claim 18
Dependent Claim
244 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber; separator means in communication with said discharge duct for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means; a rotor carrying said impact tool means and including blower means for generating pressure air for pneumatic conveying of said material withdrawn from said grinding chamber to said separator means; and means forming an air lock between said first outlet and said grinding chamber and operative to effect pneumatic decoupling therebetween.
Claim 19
Dependent Claim
244 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber; separator means in communication with said discharge duct for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means; a rotor carrying said impact tool means and including blower means for generating pressure air for pneumatic conveying of said material withdrawn from said grinding chamber to said separator means; and means forming an air lock between said first outlet and said grinding chamber and operative to effect pneumatic decoupling therebetween.
Claim 20
Dependent Claim
34 words
The impact grinding apparatus set forth in claim 16 wherein: said apparatus is provided with means forming an air lock between said second outlet and said discharge means operative to effect pneumatic decoupling therebetween.
Claim 21
Dependent Claim
240 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means comprising an oscillating conveyor trough for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber, separator means in communication with said discharge duct for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including oscillating separator sieve means, means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means, said separator sieve means and said conveyor trough being connected to a common oscillating drive means, and said first outlet is connected to an outlet of said conveyor trough for conducting said oversize material to said grinding chamber.
Claim 22
Dependent Claim
240 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing; sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means comprising an oscillating conveyor trough for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including a discharge duct in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber, separator means in communication with said discharge duct for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including oscillating separator sieve means, means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means, said separator sieve means and said conveyor trough being connected to a common oscillating drive means, and said first outlet is connected to an outlet of said conveyor trough for conducting said oversize material to said grinding chamber.
Claim 23
Dependent Claim
244 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing first sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including shutter means and a sliding gate in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber for opening said sieve jacket to a variable degree to vary the amount of material withdrawn from said grinding chamber without passing through said sieve jacket; means defining a space for receiving material which has passed through said sieve means and material withdrawn from said grinding chamber, and separator means in communication with said space for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means.
Claim 24
Dependent Claim
244 words
Apparatus for impact grinding material to a predetermined grain size range without producing an excessive amount of undersize granular material, said apparatus comprising: a housing first sieve means disposed in said housing and comprising a curved sieve jacket defining a grinding chamber, rotating impact tool means disposed in said grinding chamber, feed means for feeding material to said grinding chamber, discharge means for discharging material in said grain size range from said housing, means for withdrawing material which has passed over but not through said sieve means from said grinding chamber including shutter means and a sliding gate in communication with said grinding chamber at a point along said sieve jacket downstream of the point of introduction of material to said grinding chamber for opening said sieve jacket to a variable degree to vary the amount of material withdrawn from said grinding chamber without passing through said sieve jacket; means defining a space for receiving material which has passed through said sieve means and material withdrawn from said grinding chamber, and separator means in communication with said space for receiving material withdrawn from said grinding chamber and for performing a separation process to separate oversize material from finer material in said grain size range, said separator means including means forming a first outlet for discharging oversize material to said grinding chamber to be ground to said grain size range and means forming a second outlet for discharging said finer material to said discharge means.
Claim 25
Independent Claim
262 words
An apparatus for impact grinding granular material to a finished product of a predetermined relatively narrow grain size range and to prevent the formation of excessive undersize material, said apparatus comprising: a feed means associated with a feed stations for feeding material to be ground; a first sieve means having curved sieve jacket defining a grinding chamber connected to the feed means, said first sieve means for passing at least some of ground material in said grain size through said sieve jacket to a discharge means for discharging material in said grain size range from said grinding apparatus; a rotating impact tool means disposed in said grinding chamber for impact grinding said material to a grain size in the grain size range; means for withdrawing material from said grinding chamber including a discharge duct in communication with the grinding chamber at a predetermined point in the grinding chamber wherein said impact tool means is interposed between the discharge duct and the feed means, said withdrawal means for withdrawing at least part of said material not passed through said first sieve means from said grinding path at the predetermined point without allowing any of the withdrawn material to reenter the grinding chamber; conveying means within the discharge duct for conveying the withdrawn material immediately to a separator means; said separator means for separating oversize material relative to said grain size range from finer material and including a first outlet means for discharging said oversize material to the grinding chamber and including a second outlet means for discharging the finer to the discharge means.
Claim 26
Independent Claim
262 words
An apparatus for impact grinding granular material to a finished product of a predetermined relatively narrow grain size range and to prevent the formation of excessive undersize material, said apparatus comprising: a feed means associated with a feed stations for feeding material to be ground; a first sieve means having curved sieve jacket defining a grinding chamber connected to the feed means, said first sieve means for passing at least some of ground material in said grain size through said sieve jacket to a discharge means for discharging material in said grain size range from said grinding apparatus; a rotating impact tool means disposed in said grinding chamber for impact grinding said material to a grain size in the grain size range; means for withdrawing material from said grinding chamber including a discharge duct in communication with the grinding chamber at a predetermined point in the grinding chamber wherein said impact tool means is interposed between the discharge duct and the feed means, said withdrawal means for withdrawing at least part of said material not passed through said first sieve means from said grinding path at the predetermined point without allowing any of the withdrawn material to reenter the grinding chamber; conveying means within the discharge duct for conveying the withdrawn material immediately to a separator means; said separator means for separating oversize material relative to said grain size range from finer material and including a first outlet means for discharging said oversize material to the grinding chamber and including a second outlet means for discharging the finer to the discharge means.
Claim 27
Dependent Claim
70 words
The apparatus set forth in claim 20 wherein: said separator means has an oscillating separator sieve means and said feed means has an oscillating conveyor trough, and wherein said separator sieve means and said conveyor trough are connected to a common oscillating drive means, said first outlet is connected to an outlet of said conveyor trough, and said oversize material is conducted to said grinding chamber from said conveyor trough.
Claim 28
Dependent Claim
52 words
The apparatus set forth in claim 20 wherein: said feed means opens centrally into said grinding chamber and said material is introduced to said grinding chamber adjacent an end surface of said sieve jacket and in a substantially axial direction with respect to an axis of rotation of said impact tool means.
Claim 29
Dependent Claim
47 words
The apparatus set forth in claim 20 wherein: said feed means opens radially into said grinding chamber through said sieve jacket and said material is fed to said grinding chamber in a substantially radial direction with respect to an axis of rotation of said impact tool means.
Claim 30
Dependent Claim
39 words
The apparatus set forth in claim 20 wherein: said discharge duct defines a pneumatic conveyor path leading from said grinding chamber to said separator means, and said material is pneumatically conveyed to said separator means through said discharge duct.
Claim 31
Dependent Claim
57 words
The apparatus set forth in claim 20 wherein: said discharge means for the material which has passed through said sieve jacket and which has been separated from oversize material in said separator means includes pneumatic conveying means and said material which has been separated is pneumatically conveyed to further separation means in communication with said discharge means.
Claim 32
Dependent Claim
44 words
The apparatus set forth in claim 20 wherein: said apparatus includes a grinding rotor carrying said impact tool means and including a blower rotor means for generating pressure air and for conveying said material pneumatically by said air pressure air to said separator means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |