Threaded fastening

Patent metadata

Field	Value
Publication number	US-10436236-B2
Application number	US-201715728630-A
Country	US
Kind code	B2
Filing date	Oct 10, 2017
Priority date	Oct 10, 2017
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A fastener assembly includes a stud, a threaded sleeve, and a compression spring. The stud includes a shaft with a first head at one end and a second head at an opposite end of the shaft, both heads with opposing bearing surfaces. The threaded sleeve is disposed about the shaft. The threaded sleeve includes external threads and a tubular interior with an inwardly projected shoulder. The compression spring is disposed about the shaft inside the threaded sleeve, with a first end bearing against a shoulder of the threaded sleeve and a second end bearing against a bearing surface of the second head. The spring urges the sleeve against the bearing surface of the first head. The assembly can maintain a preload between two components while allowing the components to be separated, and can also be used as a pressure limiter.

First claim

What is claimed is:

1. A fastener assembly comprising:
a stud comprising an elongated shaft, a first head at one end of the shaft and a second head at an opposite end of the shaft, a bearing surface of the first head opposing a bearing surface of the second head;
a threaded sleeve disposed about the elongated shaft of the stud and comprising an exterior surface adapted for connecting to a threaded hole, and having an interior surface with an inwardly projected shoulder, the threaded sleeve having an outer diameter smaller than an outer diameter of the first head of the stud; and
a spring disposed about the shaft of the stud and at least partially inside the sleeve, the spring having a first end bearing against the shoulder of the threaded sleeve and having a second end bearing against the bearing surface of the second head of the stud, the spring arranged to press the sleeve against the bearing surface of the first head;
such that moving the sleeve away from the first head of the stud causes the spring to compress.

2. The fastener assembly of claim 1 , wherein at least one of the first and second heads is adapted to interface with a mating tool to impart torque on the fastener assembly.

3. The fastener assembly of claim 1 , wherein the sleeve is adapted to interface with a mating tool to impart torque on the fastener assembly.

4. The fastener assembly of claim 1 , wherein the spring comprises a compression spring.

5. The fastener assembly of claim 1 , wherein one of the first and second heads comprises at least one rib projected from a periphery of the head.

6. The fastener assembly of claim 5 , wherein the threaded sleeve comprises at least one slot configured to receive the rib, for rotationally locking the threaded sleeve.

7. The fastener assembly of claim 6 , further comprising a depth stopper that limits displacement of the sleeve away from the first head of the stud when applying torque to the fastener assembly.

8. The fastener assembly of claim 1 , wherein both the first and second heads are permanently secured to the shaft.

9. The fastener assembly of claim 1 , wherein the shaft is permanently connected to the first head, and wherein the second head is adjustably coupled to the shaft, for adjusting a preload of the spring.

10. The fastener assembly of claim 1 , wherein the second head comprises at least one rib projecting laterally into a slot of the threaded sleeve.

11. The fastener assembly of claim 1 , wherein the threaded sleeve defines slots facing away from the first head, the slots adapted to interface with a mating tool to impart torque on the threaded sleeve, for adjusting a preload of the spring.

12. The fastener assembly of claim 1 , further comprising marks on an outer surface of the first head and indicating a design preload rotation.

13. The fastener assembly of claim 1 , further comprising a seal that opens when the sleeve is moved away from the first head.

14. The fastener assembly of claim 13 , wherein the seal comprises an O-ring positioned to seal between an underside of the first head and an adjacent surface with the fastener assembly installed.

15. A method of releasably connecting two components, the method comprising:
threading the fastener assembly of claim 1 into a threaded hole defined in a first of the two components; and
compressing a second of the two components between the first component and an underside of the first head of the stud of the fastener assembly, thereby distending the fastener assembly and compressing the fastener assembly spring to maintain a preload tension in the stud shaft of the fastener assembly.

16. The method of claim 15 , wherein the second component is compressed as the fastener assembly is threaded into the hole.

17. The method of claim 15 , wherein the fastener assembly is first threaded into the hole, and then the second component is slid under the first head of the fastener assembly.

18. The method of claim 15 , wherein the threaded hole is a through hole and wherein threading the fastener assembly comprises engaging a distal end of the sleeve of the fastener assembly with a tool from a side of the first component opposite the first head of the fastener assembly.

19. The method of claim 15 , wherein compressing the second component comprises rotating the stud of the fastener assembly through a predetermined rotation angle to develop the desired preload.

20. The method of claim 19 , wherein the first head of the fastener assembly comprises a visible mark indicating the predetermined rotation angle.

21. The method of claim 20 , further comprising, after threading the fastener assembly and before compressing the second component, marking a surface of the second component with a surface mark aligned with a first feature of the fastener assembly, and wherein compressing the second component comprises rotating the first head of the fastener assembly to align the surface mark with the mark indicating the predetermined rotation angle.

22. A method of limiting pressure in a volume, the method comprising threading the fastener assembly of claim 1 into a threaded hole defined through a wall at least partially enclosing the volume, such that the threaded fastener assembly seals the threaded hole; and
leaving an entrance to an exit flow path associated with the fastener assembly exposed to the volume, such that the volume pressure works against the spring to cause the first head of the stud to move away from the sleeve to open the exit flow path from the entrance to an environment about the first head of the fastener assembly in response to the volume pressure exceeding a predetermined limit.

23. A fastener assembly comprising:
a stud comprising an elongated shaft, a first head at one end of the shaft and a second head at an opposite end of the shaft, a bearing surface of the first head opposing a bearing surface of the second head;
a threaded sleeve disposed about the elongated shaft of the stud and comprising an exterior surface adapted for connecting to a threaded hole, and having an interior surface with an inwardly projected shoulder; and
a spring disposed about the shaft of the stud and at least partially inside the sleeve, the spring having a first end bearing against the shoulder of the threaded sleeve and having a second end bearing against the bearing surface of the second head of the stud, the spring arranged to press the sleeve against the bearing surface of the first head;
such that moving the sleeve away from the first head of the stud causes the spring to compress;
wherein the second head comprises at least one rib projecting laterally into a slot of the threaded sleeve.

24. A fastener assembly comprising:
a stud comprising an elongated shaft, a first head at one end of the shaft and a second head at an opposite end of the shaft, a bearing surface of the first head opposing a bearing surface of the second head;
a threaded sleeve disposed about the elongated shaft of the stud and comprising an exterior surface adapted for connecting to a threaded hole, and having an interior surface with an inwardly projected shoulder; and
a spring disposed about the shaft of the stud and at least partially inside the sleeve, the spring having a first end bearing against the shoulder of the threaded sleeve and having a second end bearing against the bearing surface of the second head of the stud, the spring arranged to press the sleeve against the bearing surface of the first he

Assignees

• Velcro BVBA

Inventors

• Hodsdon Jerry G
• Libby Christopher C
• Barker James R

Classifications

• F16B35/041

  Specially-shaped shafts (shape of thread F16B33/02) · CPC title

• F16B35/02

  divided longitudinally · CPC title

• F16B31/04

  for maintaining {a} tensile load · CPC title

• F16B31/00

  Screwed connections specially modified in view of tensile load; Break-bolts (shape of thread {F16B33/02; in couplings F16D9/00}) · CPC title

• F16B5/0266

  using springs · CPC title