Claims
- 1. A method of producing a nonwoven web comprising:
- providing a plate having a perforated, elastomeric sheet adhered thereto with deflectible pins resiliently mounted in said perforations,
- providing a robotized head for depositing a continuous strand in a programmed pattern,
- wherein said head includes a freely rotatable, strand guiding tube projecting therefrom and terminating in a horn having a curved length, and
- lowering said horn below the tops of the pins and then depositing said strand from said horn in between said pins according to said programmed pattern.
- 2. The method of claim 1 wherein said head is a block having a passage therethrough and said tube is rotatably mounted in said passage.
- 3. The method of claim 1 wherein said head has an aperture extending therethrough and a driven rotor mounted in said aperture, said rotor having an eccentric passage therethrough, said tube being rotatably mounted in said passage.
- 4. The method of claim 1 wherein the pins are aligned in a plurality of rows and wherein is provided a transfer device for lifting a deposited strand from the bed, said transfer device comprising a plurality of blades and transverse bars holding the blades in space parallelism each blade being adapted for insertion into said bed beneath a deposited pattern, between adjacent rows of pins.
- 5. A method of preparing a reinforcing web for a composite structure comprising:
- laying the end of a continuous strand in a bed of densely packed deflectible pins, resiliently mounted in said bed,
- depositing the strand continuously beneath the tops of said pins by guiding it therethrough according to one or more desired patterns while
- simultaneously pulling the strand from a package, and then
- cutting the strand and transferring the web intact for further processing into a composite structure.
- 6. The method of claim 5 further comprising guiding said strand in a pattern of repeating, closed, geometrical shapes.
- 7. The method of claim 6 further comprising guiding said strand in a pattern of overlapped rows of shingled loops
- 8. The method of claim 7 further comprising guiding said strand through a freely rotatable tube programmed for movement according to said pattern, said tube terminating in a curved length projecting into said bed of pins.
CROSS-REFERENCE
This is a continuation-in-part of my copending application Ser. No. 445,166, filed Nov. 29, 1982, now U.S. Pat. No. 4,715,924.
Plastic composites reinforced with fibers are known and used in a wide variety of aerospace, industrial and sporting applications. Initially, the reinforcing structures were woven fabrics which provided uniformity throughout the composite. However, nonwoven webs are now being used because they are less expensive than woven fabrics. Normally such webs have been laid down randomly or in a semi-ordered fashion. It is apparent that improved composites could be produced if the nonwoven web could be laid down in a precisely ordered fashion. In some composites, complete uniformity is desired, whereas, in others, the fiber density should be greater at the locations where the stresses are greater.
According to the method of the present invention, a reinforcing web for a composite structure is prepared by first laying the end of a continuous strand in a bed of densely packed pins. After the end is located, the strand is deposited continuously beneath the tops of the pins by guiding it through the bed according to a desired pattern, while simultaneously pulling the strand from a package. When a complete web has been laid, the strand is cut and the web is transferred intact for further processing into a composite structure. In the guiding step, the strand is advanced in a pattern of repeating, closed geometrical shapes.
US Referenced Citations (11)
Foreign Referenced Citations (5)
| Number |
Date |
Country |
| 0110698 |
Jun 1984 |
EPX |
| 3003666 |
Aug 1981 |
DEX |
| 0482903 |
Jan 1973 |
JPX |
| 1088931 |
Oct 1967 |
GBX |
| 2024052 |
Jan 1980 |
GBX |
Non-Patent Literature Citations (1)
| Entry |
| American Machinist, vol. 125, #11, Nov., 1981, pp. 3 & 179. |
Continuation in Parts (1)
|
Number |
Date |
Country |
| Parent |
445166 |
Nov 1982 |
|
Patent Grant
4976012
