AU2018102053A4 - A bolt for use in an aperture having a damaged thread - Google Patents

Abstract

Abstract A bolt (10) comprising a shaft (12) having a head (22) at a first end (18) 5 thereof and a cylindrical sleeve (14) to be received within a threaded aperture. The sleeve (14) includes a first external thread (32) to engage with a damaged internal thread in the aperture (16) and a tapered internal thread (34). The shaft (12) includes a cylindrical first portion (24) extending from the first end (18) to a location between the first end (18) and a second end (19). 10 The first portion (24) includes a second external thread (26). A second portion (25) of the shaft 12 extending from the first portion (24) to the second end (19) tapers inwardly and includes a third external thread (28) such the second portion (25) may be received within the sleeve (14) and rotated to engage with the internal thread (34) of the sleeve (14), thereby expanding the sleeve (14) 15 and fixing the bolt (10) relative to the aperture (16). co coo N-N (0 LO

Description

COMPLETE SPECIFICATION

For an Innovation Patent

Invention title:

“A BOLT FOR USE IN AN APERTURE HAVING A DAMAGED THREAD”

Applicant:

Craig Oldnall & Peter Adams

Associated provisional applications:

The following statement is a full description of the invention, including the best method of performing it known to me:

2018102053 11 Dec 2018 “BOLT FOR USE IN AN APERTURE HAVING A DAMAGED THREAD”

Field of the Invention [001] The present invention relates to a bolt which may be used in an aperture having a damaged thread.

Background to the Invention [002] It is not uncommon for internal threads provided in apertures to become damaged. When sufficiently damaged, the hole will no longer support the bolt for which it was originally intended. One known method of rectifying the damage is to drill out and tap the hole with a new thread, and then use a larger bolt matching the new thread. This process can be a relatively timeconsuming way to perform the repair.

[003] One alternative method for repairing a damaged thread is to insert a specially designed wire coil into the hole that can fill the space between the damaged thread and a newly installed bolt. A disadvantage with such a solution however is that these types of coils may not be suitable for all applications, particularly when the reinstalled bolt is required to support a significant load.

[004] The present invention relates to a bolt which may be used in holes where the internal thread has been damaged. The bolt is aimed at providing a simple repair process in which a strong bolted connection results.

Summary of the Invention [005] According to one aspect of the present invention there is provided a bolt comprising:

a shaft having a head at a first end thereof;

2018102053 11 Dec 2018 a cylindrical sleeve to be received within a threaded aperture, the sleeve including a first external thread to engage with a damaged internal thread in the aperture, a tapered internal thread tapering from inwardly from a first end of the sleeve to a second end of the sleeve and a longitudinal slot to allow for expansion of the sleeve;

wherein the shaft includes a cylindrical first portion extending from the first end thereof to a location between the first end and a second end, the first portion including a second external thread, and a second portion extending from the first portion to the second end, wherein the second portion of the shaft tapers inwardly and includes a third external thread such the second portion may be received within the sleeve and rotated to engage with the internal thread of the sleeve, thereby expanding the sleeve and fixing the bolt relative to the aperture.

[006] Preferably a radius of the first portion of the shaft is greater than the width of the head such that a nut may be received over the head onto the first portion of the shaft [007] Preferably the head comprises a hex head.

[008] Preferably the slot extends from a first end of the sleeve to a second end of the sleeve.

[009] In one embodiment, the shaft includes a circumferential groove adjacent the junction of the first and second portions of the shaft.

Brief Description of the Drawings [010] The invention will now be described, by way of example, with reference to the following drawings:

[011] Figure 1 is a side view of a bolt in accordance with the present invention;

[012] Figure 2 is a side view of the sleeve of the bolt of Figure 1 prior to engagement with an applicator;

2018102053 11 Dec 2018 [013] Figure 3 is a side view of the sleeve engaged with the applicator;

[014] Figure 4 is a side view of the sleeve and applicator prior to insertion into an aperture;

[015] Figure 5 is a side view of the sleeve and applicator inserted into the aperture;

[016] Figure 6 is a side view of the bolt of Figure 1 prior to insertion of the into the aperture;

[017] Figure 7 is a side view of the bolt of Figure 1 showing the shaft engage with the sleeve within the aperture; and [018] Figure 8 is a side view of the bolt of Figure 1 engaged into the aperture and a receiving a nut.

Detailed Description of Preferred Embodiments [019] Referring to Figures, there is shown a bolt 10 comprising generally a shaft 12 and a sleeve 14. The shaft 12 and the sleeve 14 are to be engaged together within an aperture 16 within a body 17, where the aperture 16 has a damaged internal thread. The shaft 12 and the sleeve 14 engage within the aperture 16 such that a first end 18 of the shaft 12 extends outwardly from the aperture for engagement with a nut 20. The nut 20 may be engaged with the shaft 12 to secure an item to the body 17.

[020] The sleeve 14 of the bolt 10 comprises a cylindrical sleeve of constant cross section having a slot 30 extending from a first end thereof to a second end thereof. The slot 30 is provided to allow expansion of the sleeve 14 in use. The sleeve 14 includes a first external thread 32 on an outer surface thereof extending from the first end to the second end of the sleeve 14. The sleeve 14 includes also an internal thread 34. The internal thread 34 is tapered such that the internal thread 34 tapers inwardly from the first end to the second end thereof.

[021] The shaft 12 of the bolt 10 includes a head 22 at a first end thereof for engagement by a tool. The head 22 may comprise a hex head for engagement by a suitable tool for rotating the shaft 12. The shaft 12 includes

2018102053 11 Dec 2018 a first portion 24 being cylindrical and extending from the first end 18 towards a second end 19 of the shaft 12. The first portion 24 of the shaft 12 extends from the first end 18 to a location located between the first and second ends and 19. The shaft 12 includes also a second portion 25 extending from the first portion 24 to the second end 19. The radius of the first portion 24 of the shaft 12 is greater than the width of the head 22 such that the nut 20 may be received over the head 22 onto the first portion 24 of the shaft.

[022] The first portion 24 of the shaft 12 includes a second external thread 26. The second external thread 26 is provided to be engaged by the nut 20 once the shaft 12 is secured relative to the aperture 16. The second portion 25 of the shaft 12 tapers inwardly from the first portion 24 to the second end of the shaft 12. The inwardly tapering second portion 25 of the shaft 12 includes a third external thread 28 thereon. The tapering second portion 25 of the shaft 12 is shaped such that it may be received in use within the sleeve 14 to engage with the internal thread 34 thereof. The shaft 12 includes also a circumferential groove 44 adjacent the junction of the first and second portions 24 and 25 of the shaft 12.

[023] In use, the sleeve 14 is to be inserted into the aperture 16. An applicator 36 is provided for inserting the sleeve 14 into the aperture 16. The applicator 36 comprises an elongate member having a head 38 at a first end thereof and a tapered thread 40 at the second end thereof. The tapered thread 40 is provided to be received within the internal thread 34 of the sleeve 14 such that the sleeve 14 can be engaged with the applicator 36 and inserted into the aperture 16. The sleeve 14 may then be rotated into the aperture 16 by using a suitable tool engaged with the head 38 of the applicator 36. The applicator 36 includes is a shoulder portion 42 adjacent a proximal end of the tapered thread 40 such that the shoulder portion 42 engages with the first end of the sleeve 14 once the sleeve 14 has reached an inner end of the aperture

16. Engagement with the shoulder portion 42 prevents further movement of the applicator 36 relative to the sleeve 14 such that the applicator 36 does not expand the sleeve 14.

2018102053 11 Dec 2018 [024] The shaft 12 may then be inserted into the aperture 16 such that the second portion 25 of the shaft 12 is received within the sleeve 14 (as can be seen in Figure 7). Rotation of the shaft 12 by a suitable tool causes the second portion 25 of the shaft 12 to rotate within the sleeve 14 thereby expanding the sleeve 14 and clamping bolt 10 within the inside of the aperture

16. The first portion 24 of the shaft 12 remains extending outwardly from the aperture 16 such that the first portion 24 may receive a nut 20 in order to secure a further item to the body 17.

[025] It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention.

Claims (5)

1. The claims defining the invention are as follows:

   1. A bolt comprising:

   a shaft having a head at a first end thereof;

   a cylindrical sleeve to be received within a threaded aperture, the sleeve including a first external thread to engage with a damaged internal thread in the aperture, a tapered internal thread tapering from inwardly from a first end of the sleeve to a second end of the sleeve and a longitudinal slot to allow for expansion of the sleeve;

   wherein the shaft includes a cylindrical first portion extending from the first end thereof to a location between the first end and a second end, the first portion including a second external thread, and a second portion extending from the first portion to the second end, wherein the second portion of the shaft tapers inwardly and includes a third external thread such the second portion may be received within the sleeve and rotated to engage with the internal thread of the sleeve, thereby expanding the sleeve and fixing the bolt relative to the aperture.
2. 2. A bolt in accordance with claim 1, wherein a radius of the first portion of the shaft is greater than the width of the head such that a nut may be received over the head onto the first portion of the shaft
3. 3. A bolt in accordance with claim 2, wherein the head comprises a hex head.
4. 4. A bolt in accordance with any one of the preceding claims, wherein the slot extends from a first end of the sleeve to a second end of the sleeve.
5. 5. A bolt in accordance with any one of the preceding claims, wherein the shaft includes a circumferential groove adjacent the junction of the first and second portions of the shaft.