Perforated Sheet Patents (Class 209/397)
  • Patent number: 4758333
    Abstract: A sieve is found useful for the separation of solid particles having substantially equal length and width dimensions from elongate shaped particles, comprising a corrugated sheet having sieve openings on the pitch between ridges and furrows of the corrugations and imperforate furrow bottoms.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: July 19, 1988
    Assignee: General Electric Company
    Inventors: Gregory M. Masica, Eric J. Straub
  • Patent number: 4729949
    Abstract: A method for placing individual living cells at identifiable locations is provided comprising the steps of:(a) providing a carrier having a plurality of apertures, the apertures being arranged in an ordered array and being sized to hold individual cells;(b) applying a fluid containing living cells to the carrier; and(c) applying a force to the cells to move the cells into the apertures.
    Type: Grant
    Filed: November 8, 1983
    Date of Patent: March 8, 1988
    Assignee: Bar-Ilan University
    Inventors: Arye Weinreb, Mordechai Deutsch
  • Patent number: 4717471
    Abstract: In screening apparatus for paper making fiber incorporating a cylindrical screen member provided with cylindrical screening perforations, each of the perforations is characterized by a concentric frustoconical inlet end portion having a maximum diameter at the inlet surface of the screening member which is substantially greater than the portion of the perforation of minimum diameter, the maximum diameter of these inlet end portions being such that adjacent such portions closely approach or intersect each other to define multiple ridges on the surface of the inlet side of the screening member.
    Type: Grant
    Filed: June 4, 1987
    Date of Patent: January 5, 1988
    Assignee: The Black Clawson Company
    Inventor: Jimmy L. Winkler
  • Patent number: 4640364
    Abstract: In a ballast cleaning machine which comprises a machine frame, a ballast excavating and conveying chain mounted on the machine frame, the chain having a discharge end for the excavated and conveyed ballast, ballast screening apparatus arranged to receive the ballast from the discharge end of the chain and to separate a waste component from the clean ballast, a conveyor band system mounted below the screening apparatus for receiving the clean ballast component and redistributing it to the track, and an endless conveyor band mounted below the screening apparatus for receiving and conveying the waste component: a sifting conveyor band mounted between the discharge end of the chain and the screening apparatus, the sifting conveyor band having an upper stringer receiving the excavated and conveyed ballast from the discharge end and defining openings permitting a portion of the waste component to pass through the sifting conveyor band, and a drive connected to the sifting conveyor band for driving the band whereby
    Type: Grant
    Filed: September 17, 1984
    Date of Patent: February 3, 1987
    Assignee: Franz Plasser Bahnbaumaschinen Industriegesellschaft m.b.H.
    Inventor: Josef Theurer
  • Patent number: 4600019
    Abstract: The adjustable chaffer and lower sieve of a combine harvester are replaced by a cob catcher or cob-saving sieve which allows corncobs along with shelled corn to be recovered as a mixture from the harvester rather than separating the corn from the cobs and discarding the cobs. The cob-saving sieve comprises a framework incorporating parallel inclined vanes sufficiently spaced apart to allow cobs to pass therethrough and disposed at an angle to direct airflow from the harvester fan over the surface of the sieve for removal of unwanted material.
    Type: Grant
    Filed: May 13, 1985
    Date of Patent: July 15, 1986
    Inventor: Chester L. McBroom
  • Patent number: 4575421
    Abstract: A non-clogging and wear-reducing screen assembly for a vibrating screening machine including a substantially rigid plate having upper and lower sides and having first and second pairs of opposite edges, attachment members formed integrally with a plate on a first pair of opposite edges for attachment to a vibrating screening machine, a plurality of spaced openings throughout the substantially rigid plate and extending in both directions between the first and second pairs of the opposite edges, borders on the plate surrounding the openings, a supporting screen on the upper side of the plate, first and second superimposed contiguous abutting screens overlying the supporting screen, and adhesive firmly securing the supporting screen and the first and second screens to the borders of the openings.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: March 11, 1986
    Assignee: Derrick Manufacturing Corporation
    Inventors: James W. Derrick, Robert G. Derrick
  • Patent number: 4563270
    Abstract: A screen panel for vibratory screening machines can consist of at least one cast, injection-molded or vulcanized perforated plate of elastically flexible material, such as plastic or rubber. It has a multitude of screen openings (5) and crosspieces (2, 3, 4) surrounding them which are interconnected forming one piece and thus the perforated plate. A self-cleaning effect can be achieved with such a perforated plate in the area of each individual screen opening (5) by means of a relative movement of the edges of the screen openings in order to extend the self-cleaning effect to as large an area as possible of each individual screen opening (5). For this purpose, at least two of the crosspieces (2-4) surrounding the individual screen openings (5) have a differing bending resistance by means of differing cross-sections and/or reinforcements (8).
    Type: Grant
    Filed: December 4, 1981
    Date of Patent: January 7, 1986
    Inventor: Kurt Wolff
  • Patent number: 4548213
    Abstract: A device for converting a conventional combine into a unit which will crush and recover corn cobs as well as recover shelled corn comprising a flat perforated metal element which will replace the conventional chaffer and sieve in the final cleaning mechanism of the combine, the element having a plurality of fins protruding above the upper surface thereof adapted to channel and direct the flow of corn stocks and chaff thereover, the holes being of a size sufficient to allow the passage of corn cob particles therethrough.
    Type: Grant
    Filed: August 13, 1984
    Date of Patent: October 22, 1985
    Inventors: James E. Phillips, Jerome J. Cassellius
  • Patent number: 4529520
    Abstract: A screen plate with grooves is described. The grooves are provided at the bottom with perforations. The direction of the grooves substantially deviates from the flow direction of the pulp to be screened. By different inclination of the side planes of the grooves the turbulance force on the pulp can be varied to meet the different needs of various screening applications.
    Type: Grant
    Filed: March 7, 1983
    Date of Patent: July 16, 1985
    Assignee: A. Ahlstrom Osakeyhtio
    Inventor: Harry Lampenius
  • Patent number: 4486302
    Abstract: In a screen consisting of a supporting frame (1) which is covered with apertured (6) screen elements (2) of resilient material, said screen elements (2) are well supported and particularly easy to replace without intervention, e.g. by way of welding, as they have longitudinal guide grooves (7) which have a profile serving to be snapped on to the upper layer (3) of the supporting frame (1) and such a depth that the lower layer (4) of the supporting frame (1) engages the underside of the screen elements (2). In a preferred embodiment the wires or bars in the lower layer (4) of the supporting frame are disposed so as to be out of alignment with the apertures (6) of the screen elements so that also the wires in this layer are protected against wear.
    Type: Grant
    Filed: June 4, 1982
    Date of Patent: December 4, 1984
    Assignee: Aktieselskabet Nordiske Kabel- og Traadfabriker
    Inventor: Aage B. Jorgensen
  • Patent number: 4473466
    Abstract: A flat sieve, or a part thereof, has a flat body of elastic material with a rectangular (or square) frame spanned by a plate of lesser depth with a multiplicity of throughgoing parallel slots and intervening rows of shorter slots interrupted by solid transverse webs which are integral with crossbars intersecting only the lower portions of the longer, throughgoing slots. The length of the shorter slots may be about one-tenth that of the longer slots.
    Type: Grant
    Filed: March 2, 1983
    Date of Patent: September 25, 1984
    Assignee: Isenmann Drahterzeugnisse GmbH
    Inventors: Gerhard Schmidt, Wolfgang Lehmann
  • Patent number: 4447320
    Abstract: A device for cleaning and recovering paper pulp includes a tank divided into inner and outer chambers by a fixed cylindrical sieve. The inner chamber also contains a rotating drum with blades that draw acceptable pulp from the outer chamber through the sieve to the inner chamber for discharge and moves rejected material through a helical path in the outer chamber toward another discharge point. The end of the helical path is blocked to form a dead space where the rejected material is concentrated and then periodically discharged.
    Type: Grant
    Filed: January 21, 1982
    Date of Patent: May 8, 1984
    Assignee: E et M Lamort
    Inventor: Jean-Pierre J. Lamort
  • Patent number: 4379056
    Abstract: An improved filtering system that includes a cleaning assembly and a filter element in the form of a plate or drum with a plurality of long, narrow through openings or slits in each of a plurality of rows. The improved cleaning assembly and filter element includes slit cleaning elements connected downstream of the hill and dale filter element or an improved slit cleaning element upstream of the flat surface or drum surface of a filter with upstream connecting slits. The cleaning assembly may also include a scraper cleaning element positioned for relative movement in relationship to the filter element. As fluid enters the filtering system, the debris or trash is filtered from the fluid and deposited on the upstream surface of the filter element and in the slits for removal by the cleaning assembly.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: April 5, 1983
    Inventor: Tadashi Hagihara
  • Patent number: 4351719
    Abstract: A vibratory screen apparatus is employed to continuously separate particles of random sizes, such as wood chips, into groups large, medium and small sized particles. A vibratory frame has a horizontal platform driven in vibratory movement to convey particles on the platform to one end of the platform. Upper and lower inclined screens are mounted upon the platform, particles are fed to the upper end of the upper screen which will pass medium and small sized particles passing through the lower screen to the platform. Gravitational movement of particles down the inclined upper screen is delayed by the vibratory movement of the screen; abutment surfaces on the upper surface of the upper screen imparting intermittent upward movement to particles on that surface which resists, but does not overcome gravitationally induced flow of the particles.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: September 28, 1982
    Assignee: Morbark Industries, Inc.
    Inventor: Larry L. Morey
  • Patent number: 4287066
    Abstract: A sieve sheet having radially extending separating slots in order to subdivide the area of the sieve sheet into sieve segments. The separating slots are embedded with plastics material. The sieve segments may be arranged in a configuration differing slightly from a plane, thus stiffening the sieve.
    Type: Grant
    Filed: September 8, 1976
    Date of Patent: September 1, 1981
    Assignee: Elfo AG Sachseln
    Inventors: Albert Greutert, Ernst Stumvoll
  • Patent number: 4276159
    Abstract: In screening apparatus for paper making fiber incorporating a cylindrical screen member provided with screening perforations which are either cylindrical or slotted in section, the perforations are characterized by greater flow area on the inlet side of the cylinder than on the accepts side of the cylinder. More specifically, each of the screening perforations includes a generally funnel-shaped portion on the inlet side of the cylinder which leads to a short parallel sided portion on the accepts side of the cylinder.
    Type: Grant
    Filed: June 19, 1980
    Date of Patent: June 30, 1981
    Assignee: The Black Clawson Company
    Inventor: Donald F. Lehman
  • Patent number: 3943054
    Abstract: A segmented screen body or bottom for classification, screening and washing of fragmented hard stocks employs a multiplicity of segmented elements constructed of elastomer or rubber material which, when abutted and supported in predetermined relations, define sieve apertures of a predetermined size and extending, if desired, in staggered longitudinal rows. The structure further requires a multiplicity of parallel transverse metal wires or equivalent elements which are embedded and extend through appropriate apertured portions of the elastic components. In the preferred form the essential elements include T-shaped and L-shaped elements, all of which may be obtained from identical integral moldings of T-shape and many of which are cut along transverse lines at the T-top to provide from the same moldings complementary L-shaped elements.
    Type: Grant
    Filed: December 19, 1974
    Date of Patent: March 9, 1976
    Assignee: Durex Products, Inc.
    Inventor: Gordon L. Simonson