AU2023202849A1

AU2023202849A1 - Liner Bolt

Info

Publication number: AU2023202849A1
Application number: AU2023202849A
Authority: AU
Inventors: Craig Oldnall
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-05-13
Filing date: 2023-05-08
Publication date: 2023-11-30

Abstract

A liner bolt (10) including a head (14) having an opening (28) in an end thereof 5 and an elongate stud (12) having an external thread on a first end (16) for engagement into the opening (28) in the head (14). The stud (12) includes also a threaded portion (18) adjacent a second end (16) for receiving a nut (20). A slot (36) is provided adjacent the second end (17) of the stud (12) to receive a washer (38) such that when a tool (15) is engaged with the nut (20) to loosen 10 the nut (20), the nut (20) once loosened engages with the washer (38) to rotate the stud (12) relative to the head (14) to disengage the stud (12) from the head (14). 2/7 36 38 17 12 10 16 34 41 18 2 27 32 28 24 26 14 25 Fig 2

Description

2/7

36 38

17 12 10 16

34 41

18 2 27 32 28 24 26 14 25

Fig 2

AUSTRALIA

Patents Act 1990

COMPLETE SPECIFICATION

Invention title:

"Liner Bolt"

Applicant:

Craig Oldnall

Associated provisional applications:

Number 2022901279 filed on 13 May 2022

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

"Liner Bolt"

Field of the Invention

[001] The present invention relates to a liner bolt for securing a sacrificial wear surface, such as a liner within a grinding mill.

Background to the Invention

[002] Grinding mills use liners which are secured to the inner surface of the mill by liner bolts. The liners provide both a protective surface, as well as surface features to assist with the grinding process.

[003] As the liners wear, it is necessary to periodically replace the liners. Liner bolts commonly comprise a shaft having a widened head which is received through a hole in the liner from the inside. The end of the liner bolt extends to the outside of the mill, where it is secured by a nut. When it is time to replace the liners, the nuts are removed and the bolts pushed inwardly into the inside of the mill. As these bolts can become jammed within the liner during operation of the mill, pushing the bolts inwardly will often require the use an impact tool used to drive the bolt inwardly. Alternatively, the bolts may be driven by placing a rod against the outer end and driving with a hammer.

[004] The time taken to drive in the bolts can be significant. As any time in which a mill is not operating results in increased costs, it is therefore important to ensure that the replacement of the liners can be achieved as efficiently as possible. Alternative bolts have been proposed where the shaft of the bolt is threaded into the head of the bolt within the mill. Removal of such bolts comprises firstly removing the nut from the shaft of the bolt and then unthreading the shaft from the head.

[005] The present invention relates to a liner bolt having a construction aimed at reducing the time required to disconnect and remove such a two part liner bolt.

Summary of the Invention

[006] According to one aspect of the present invention there is provided a liner bolt comprising: a head having an opening in an end thereof with an internal thread; and an elongate stud having an external thread on a first end for engagement into the opening in the head and a threaded portion adjacent a second end for receiving a nut; wherein a slot is provided adjacent the second end of the stud to receive a washer such that when a tool is engaged with the nut to loosen the nut, the nut once loosened engages with the washer to rotate the stud relative to the head to disengage the stud from the head.

[007] In a preferred embodiment, the washer is a C-shaped washer.

[008] Preferably the groove comprises a circumferential groove provided between the threaded portion and the second end of the stud.

[009] Preferably the washer includes an outer edge having a diameter less than that of the nut such that a socket type tool can be received over the second end of the stud to engage with the nut without interference from the washer.

[010] Preferably the opening in the head is inwardly tapered and the first end of the stud includes an inwardly tapered end portion having the external thread such that the first end of the stud is engageable in the opening in the head.

[011] In a preferred embodiment, the head includes an inwardly tapered first end portion adjacent the first end.

[012] Preferably the head includes a second end portion having a constant transverse cross section.

[013] Preferably the second end portion of the head is obround in transverse cross section.

[014] Preferably the first end portion of the head tapers inwardly in respect of height and not width.

Brief Description of the Drawings

[015] The invention will now be described, byway of example, with reference to the following drawings in which:

[016] Figure 1 is a perspective view of a liner bolt in accordance with the present invention;

[017] Figure 2 is a perspective view of the liner bolt of Figure 1 with the head of the bolt removed;

[018] Figure 3a is a side view of the liner bolt of Figure 1;

[019] Figure 3b is a side cross sectional view of the liner bolt of Figure 1;

[020] Figure 4a is a first end view of the liner bolt of Figure 1;

[021] Figure 4b is a second end view of the liner bolt of Figure 1;

[022] Figure 5 is a side view of the liner bolt engaged with a liner plate;

[023] Figure 6 is a side view showing a tool engaging with the nut of the liner bolt for removal of the nut; and

[024] Figure 7 is side view showing removal of the nut engaging with a washer on the liner bolt.

Detailed Description of Preferred Embodiments

[025] Referring to the Figures, there is shown a liner bolt 10 comprising an elongate stud 12 and a head 14. The head 14 is engageable with a first end 16 of the stud 12 to form the liner bolt 10. The liner bolt 10 is to be used to secure a liner plate 11 to an outer shell 13 of a grinding mill. A compressible lining 19 may also be provided between the outer shell 13 and the liner plate 11.

[026] The stud 12 comprises an elongate member of circular cross-section. The stud 12 includes a threaded portion 18 adjacent a second end 17 thereof. The threaded portion 18 is provided for receiving a nut 20 in use. The second end 17 of the stud 12 protrudes outwardly from the shell 13 of the mill such that engaging the nut 20 to the threaded portion 18 of the liner bolt 10 engages the liner bolt 10 with the liner plate 11 such that the liner plate 11 is secured to an inner surface of the shell 13.

[027] In the embodiment shown, the head 14 includes a first end portion 24 adjacent a first end which tapers inwardly. The head 14 includes also a second end portion 25 extending from the first end portion 24 to a second end of the head 14. The second end portion 25 has a constant transverse cross section.

[028] As can be seen in Figure 4a, the second end portion 25 of the head 14 in the embodiment shown is obround in transverse cross section. That is, the head 14 adjacent the second end portion 25 comprises linear parallel side walls 26 connected at opposed ends by arcuate end walls 27. The first end portion 24 of the head 14 tapers inwardly in respect of the height only (being the distance between the end walls 27) and not the width (being the distance between the side walls 26). The first end portion 24 is therefore also obround in transverse cross section with the first end portion 24 reducing in cross sectional area such that the first end portion 24 is circular in transverse cross section at the first end 21 of the head 14.

[029] The head 14 includes an opening 28 in the first end 21 thereof. The opening 28 is circular in transverse cross section and tapers inwardly such that an inner end thereof has a smaller diameter than an outer end thereof. The opening 28 includes an internal thread on an inner surface thereof. The first end 16 of the stud 12 includes a tapered end portion 32 at the first end 16 thereof. The tapered end portion 32 also tapers inwardly corresponding to the inward taper of the opening 28, such that the tapered end portion 32 may be received within the opening 28. The tapered end portion 32 of the stud 12 includes an external thread 34 thereon. The external thread 34 is complementary to the internal thread such that the first end 16 of the stud 12 may be screwed into the opening 28 in the head 14.

[030] The second end 17 of the stud 12 is provided with a groove 36 provided to receive a washer 38. The groove 36 comprises a circumferential groove provided between the threaded portion 18 and the second end 17 of the stud 12. The washer 38 is C-shaped such that the washer 38 can be pressed towards the side of the stud 12 to engage with the stud 12 such that an inner edge 40 of the washer 38 is received within the groove 36 (as can be seen in Figure 4b). The washer 18 includes an outer edge 41 having a diameter less than that of the nut 20 such that a socket type tool 15 can be received over the second end 17 of the stud 12 to engage with the nut 20 without interference from the washer 38.

[031] Figure 5 shows a liner bolt 10 secured in place to a grinding mill prior to removal of the liner plate 11. A further washer 42 may be provided between the nut 20 and the outer shell 13. The washer 38 may be engaged with the second end 17 of the stud 12 only at the time of removal of the liner bolt 10, or may be installed earlier. A tool 15 having a socket is placed over the second end 17 of the stud 12 as can be seen in Figure 6. On operation of the tool 15, the nut 20 is loosened to disengage the clamping force between the liner plate 11 and the outer shell 13 of the grinding mill.

[032] As can be seen in Figure 7, when the nut 20 approaches the second end 17 of the stud 12, the nut 20 engages with the washer 38. The nut 20 forces the washer 38 into engagement with the edge of the groove 36 and thereby binds the washer 38 and nut 20 together. Further rotation of the tool 15 thereby applies a rotational force to the stud 12 such that the stud 12 is rotated out of engagement with the head 12. This arrangement thereby allows both the removal of tension applied via the nut 20 and disengagement of the stud 12 from the head 14 in a single operation with a single tool 15.

[033] 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

The claims defining the invention are as follows:

1. A liner bolt comprising: a head having an opening in an end thereof with an internal thread; and an elongate stud having an external thread on a first end for engagement into the opening in the head and a threaded portion adjacent a second end for receiving a nut; wherein a slot is provided adjacent the second end of the stud to receive a washer such that when a tool is engaged with the nut to loosen the nut, the nut once loosened engages with the washer to rotate the stud relative to the head to disengage the stud from the head.

2. A liner bolt in accordance with claim 1, wherein the washer is a C-shaped washer.

3. A liner bolt in accordance with claim 1 or 2, wherein the groove comprises a circumferential groove provided between the threaded portion and the second end ofthe stud.

4. A liner bolt in accordance with any one of claims 1 to 3, wherein the washer includes an outer edge having a diameter less than that of the nut such that a socket type tool can be received over the second end of the stud to engage with the nut without interference from the washer.

5. A liner bolt in accordance with any one of the preceding claims, wherein the opening in the head is inwardly tapered and the first end of the stud includes an inwardly tapered end portion having the external thread such that the first end of the stud is engageable in the opening in the head.

6. A liner bolt in accordance with any one of the preceding claims, wherein the head includes an inwardly tapered first end portion adjacent the first end.

7. A liner bolt in accordance with claim 5, wherein the head includes a second end portion having a constant transverse cross section.

8. A liner bolt in accordance with claim 7, wherein the second end portion of the head is obround in transverse cross section.

9. A liner bolt in accordance with any one of claims 6 to 8, wherein the first end portion of the head tapers inwardly in respect of height and not width.

Craig Oldnall by his Patent Attorneys Armour IP

1 17 2023202849

MEMBERSHIP

17 36 38 12 10

41 25

18 16

27 24 26 14

Fig 1