Composite nut and bolt

• US 5,033,925 A
• Filed: 12/16/1988
• Issued: 07/23/1991
• Est. Priority Date: 12/16/1988
• Status: Expired due to Fees

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Goodrich Corporation (Rtx Corporation)
• Inventors: Moghe, Sharad R.
• Primary Examiner(s): Wilson, Neill R.
• Application Number:
  US07/285,483
• Time in Patent Office: 949 Days
• Field of Search: 411/411, 411/424, 411/366, 411/82, 411/258, 411/907, 411/908, 411/901, 411/902, 411/903, 411/904, 411/900, 405/259-261, 156/148, 156/149, 156/391-393, 156/468, 156/475
• US Class Current: 411/366.1
• CPC Class Codes: B29C 53/585 the cross-section varying along their axis, e.g. tapered, with ribs, or threads, with socket-ends
• CPC Class Codes: B29C 70/222 the structure being shaped to form a three dimensional configuration
• CPC Class Codes: B29D 1/005 fibre reinforced
• CPC Class Codes: B29K 2105/0827 Braided fabrics
• CPC Class Codes: F16B 33/006 Non-metallic fasteners using screw-thread
• CPC Class Codes: F16B 35/00 Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws F16B33/008 takes precedence; joining sheets or plates using screws with two separate threads F16B5/0275; using screws with adjustment sleeves F16B5/0283; thread cutting screws F16B25/00
• CPC Class Codes: F16B 37/00 Nuts or like thread-engaging members specially shaped for rotations by a tool F16B23/00
• CPC Class Codes: Y10S 411/901 Core and exterior of different materials
• CPC Class Codes: Y10S 411/908 Resinous material

Abstract

A hollow composite internally threaded member such as a nut includes a reinforcing fabric layer such as a braided or knit layer extending in the axial direction of the member and conforming to its threads. A method of making such an internally threaded member comprises forming and embedding in a polymeric matrix a reinforcing fabric layer on an externally threaded cylindrical core and thereafter removing the core. Such internally threaded member may be threadedly joined and adhesively bonded to an externally threaded member of complementary thread pitch and thread diameter to form a bolt. The externally threaded member may comprise an elongate core having an integral tubular fabric layer bonded to its exterior surface.

Claims

1. A hollow internally threaded member formed of fibers in a polymer matrix, said member having an interior surface having an integral thread having a rounded apex, the hollow member comprising a polymeric matrix encapsulating a bundle of successively applied coaxial reinforcing fabric layers extending throughout in the axial direction of the hollow member, the innermost layer of reinforcing fabric having continuous undulate members closely conforming to the contour of the thread.

6. In combination, the hollow member of claim 1 threadedly joined to an externally threaded member of complementary thread pitch and thread diameter.

7. The combination of claim 6 wherein the hollow member and externally threaded member are together bonded by polymeric material.

2. In combination, a hollow internally threaded member formed of fibers in a polymer matrix, said member having an interior surface having an integral thread having a rounded apex, said thread including a reinforcing fabric layer extending in the axial direction of the member and conforming to the threads, the hollow member being threadedly joined to an externally threaded member of complementary thread pitch and thread diameter and bonded thereto by polymeric material.

3. In combination, a hollow internally threaded member formed of fibers in a polymeric matrix, said member having an interior surface having an integral thread having a rounded apex, said thread including a reinforcing fabric layer extending in the axial direction of the member and conforming to the threads, the hollow member being threadedly joined to externally threaded member of complementary thread pitch and thread diameter, the externally threaded member comprising an elongate core and an integral tubular braided layer bonded to the exterior surface of the core, the braided layer including at least one element of greater radial projection relative to the core than the remainder of the elements forming the braided layer, said at least one element of greater radial projection defining the helical thread appearing on the exterior surface of the core.

4. In combination, a hollow internally threaded member formed of fibers in a polymer matrix, said member having an interior surface having an integral thread having a rounded apex, said thread including a reinforcing fabric layer extending in the axial direction of the member and conforming to the threads, the hollow member being threadedly joined to an externally threaded member of complementary thread pitch and thread diameter, the externally threaded member comprising a fiber-reinforced polymeric rod having a thread defining element helically extending around and along the lengthwise direction of the core and projecting radially outwardly of the core, and a fabric layer enveloping, conforming and secured to the outer surface of the combined core and thread-defining element.

5. In combination, a hollow internally threaded member formed of fibers in a polymer matrix, said member having an interior surface having an integral thread having a rounded apex, said thread including a reinforcing fabric layer extending in the axial direction of the member and conforming to the threads, the hollow member being threadedly joined to an externally threaded member of complementary thread pitch and thread diameter, the externally threaded member comprising a polymeric rod having reinforcing textile fibers selected from the group consisting of carbon fibers, glass fibers and aramid fibers extending throughout in the lengthwise direction of the rod, said rod having its thread reinforced by a continuous textile fabric layer enveloping, conforming and bonded with a polymeric matrix to the polymeric rod.

8. A hollow internally threaded member formed of fibers in a polymer matrix, said member having an interior surface having an integral thread having a rounded apex, said thread including a reinforcing fabric layer extending in the axial direction of the member and conforming to the threads, wherein the reinforcing fabric layer is selected from the group consisting of tubular braided fabric and tubular knit fabric.

9. The hollow member of claim 8 wherein the thread is reinforced with closely spaced fibers which extend axially of the hollow member in opposite sense helices.

10. The hollow member of claim 8 including a plurality of layers of reinforcing fabric distributed throughout.

11. In combination, the hollow member of claim 8 threadedly joined to an externally threaded member of complementary thread pitch and thread diameter.

12. The combination of claim 11 wherein the hollow member and externally threaded member are together bonded by polymeric material.