Rotary valve to feed artificial snow at constant rate

{
  "publication_number": "US6511000B2",
  "country": "US",
  "kind": "B2",
  "title": "Rotary valve to feed artificial snow at constant rate",
  "abstract": "An apparatus preventing adhesion, growth and freezing of ice pieces, which tend to happen with quality artificial snow such as fine flake snow and powder snow. The rotary valve 1 to feed artificial snow at a constant rate includes: impeller rotary shaft 3 which is placed in cylindrical casing 2 along the length direction of the cylinder; a plurality of impellers 4 which are arranged around impeller rotary shaft 3 at an equal distance from each other in the radial direction; opening 25 for loading of artificial snow which connects the top portion of a wall of cylindrical casing 2 with the top portion of a housing; opening 7 for receiving compressed air which is formed on casing side wall 6 to receive said compressed air from a blower; and an exit 10 for artificial snow formed at the other casing side wall 9 to blow out artificial snow, cut in a given amount, with compressed air. The impeller 4 is connected with the adjacent impeller at its end contacting impeller rotary shaft 3 by a smooth surface of arched plate 14 having arc 15. The opening 7 for loading of artificial snow on casing side wall 6 and the exit 10 for artificial snow on the other casing side wall 9 are arranged across from each other in arc 15 between impellers 4.",
  "claims": [
    "1. A rotary valve to feed artificial snow at a constant rate comprising: a cylindrical casing; an impeller rotary shaft which is placed in said cylindrical casing along the length direction of the cylinder; a plurality of impellers which are arranged around said impeller rotary shaft at an equal distance from each other in the radial direction; a housing which supports said cylindrical casing therein; an opening for loading of artificial snow, which connects the top portion of a wall of said cylindrical casing with the top portion of said housing; an opening for receiving compressed air, which is formed on the side wall of said casing at one end of said impeller rotary shaft to receive said compressed air from a blower; and an exit for artificial snow, which is formed on the other end of said casing wall to blow out artificial snow cut in a given amount with compressed air, wherein the diameter of said impeller rotary shaft is established to be about one half of the diameter of said cylindrical casing, wherein said impeller is connected with the adjacent impeller at its end contacting said impeller rotary shaft by a smooth surface of an arched plate having an arc; and wherein said opening for receiving compressed air on one end of the side wall of said casing and said exit for artificial snow on the other end of the side wall of said casing are arranged across from each other in said arc between said impellers.",
    "2. The rotary valve to feed artificial snow at a constant rate according to claim 1, wherein said arched plate having said arc is covered by a lubricating resin coating layer.",
    "3. The rotary valve to feed artificial snow at a constant rate according to claim 2, wherein hollow portions are formed on two sides of said impeller between said arched plate having said arc and said impeller rotary shaft, wherein a heater is placed in a heater hole at the center of said impeller rotary shaft in the axial direction, and wherein said heater hole and each of said hollow portions are connected via a plurality of thermal convection holes which are formed in the radial direction to send the heat from said heater hole to each hollow portion.",
    "4. The rotary valve to feed artificial snow at a constant rate according to one of claim 2, wherein ring grooves are formed at both ends of said impeller rotary shaft, and ring seals are engaged to said ring grooves so as to airtightly seal the sections between the ends of said impeller rotary shaft and the side walls of said cylindrical casing.",
    "5. The rotary valve to feed artificial snow at a constant rate according to claim 1, wherein hollow portions are formed on two sides of said impeller between said arched plate having said arc and said impeller rotary shaft, wherein a heater is placed in a heater hole at the center of said impeller rotary shaft in the axial direction, and wherein said heater hole and each of said hollow portions are connected via a plurality of thermal convection holes which are formed in the radial direction to send the heat from said heater hole to each hollow portion.",
    "6. The rotary valve to feed artificial snow at a constant rate according to one of claim 5, wherein ring grooves are formed at both ends of said impeller rotary shaft, and ring seals are engaged to said ring grooves so as to airtightly seal the sections between the ends of said impeller rotary shaft and the side walls of said cylindrical casing.",
    "7. The rotary valve to feed artificial snow at a constant rate according to one of claim 1, wherein ring grooves are formed at both ends of said impeller rotary shaft, and ring seals are engaged to said ring grooves so as to airtightly seal the sections between the ends of said impeller rotary shaft and the side walls of said cylindrical casing."
  ],
  "description_excerpt": "1. Field of the Invention The present invention relates to an apparatus to feed artificial snow to an artificial snow making device at a constant rate to precipitate artificial snow on a ski slope. 2. Description of the Invention An artificial snow making device to precipitate artificial snow conventionally blows out artificial snow by using the centrifugal force of rotating impellers. Kinds of artificial snow mainly include: 1) plate snow; 2) flake snow; and 3) powder snow. In the case of 1) plate snow, the ice pieces are relatively large such that they do not adhere to a feeder while being fed into the artificial snow making device. However, as the size of the ice pieces becomes smaller from 2) flake snow to 3) powder snow, it tends to adhere to the feeder. The adhered ice pieces gradually grow larger and freeze such that the feeder eventually stops functioning. Impellers 4 of a conventional artificial snow blower or a rotary valve of a feeder are formed around impeller rotary shaft 3 in the radial direction. As shown in FIG. 8, the bottoms of impeller 4 contacting impeller rotary shaft 3 form corner portions 26 at an approximately right angle. Corner portions 26 hardly catch large ice pieces 27 while fine ice pieces 27 tend to adhere thereto. As mentioned above, the adhered ice pieces grow and freeze into lumps of ice pieces 27. The lumps cause additional load to impellers 4 such that additional drive is required to maintain the rotation of impellers 4. Further, the operating surfaces of impellers 4 are reduced such that the performance is deteriorated. Finally, the en tire device is frozen and stops.",
  "cpc": [
    "F25C 3/04",
    "B65G 53/4633",
    "F25C 2400/02"
  ],
  "ipc": [
    "B65G 53/46",
    "E01H 4/02",
    "F25C 3/04"
  ],
  "assignees": [
    "KOYO INDUSTRY CO LTD"
  ],
  "inventors": [
    "FUJIWARA TAKAMASA"
  ],
  "filing_date": "2001-04-17",
  "publication_date": "2003-01-28",
  "grant_date": "2003-01-28",
  "priority_date": "2000-05-17",
  "application_number": "US-83562401-A",
  "family_id": "18651897",
  "citations": [
    "DE2606483A1",
    "DE2903323A1",
    "DE9408383U1",
    "EP0945694A1",
    "FR2573527A1",
    "GB1055578A",
    "JPH05312449A",
    "JPH11116053A",
    "US4385729A",
    "US4798331A",
    "US5062279A",
    "US5297731A"
  ]
}