GB2294420A

GB2294420A - Seized nut removal tool

Info

Publication number: GB2294420A
Application number: GB9421456A
Authority: GB
Inventors: Robert Peter Sunman
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-25
Filing date: 1994-10-25
Publication date: 1996-05-01
Also published as: GB9421456D0

Abstract

A tool for removing damaged fasteners e.g. nuts has an internal helical cutting thread 6 in a tapering bore, which enables seized or damaged fasteners iii to be removed, normally without damage to the stud iv upon which the fastener is mounted. A drive bar ii is inserted into a square section cavity a of the tool and the assembly is then rotated, causing the cutting thread 6 to bite into the fastener (iii) thus facilitating its removal. <IMAGE>

Description

HELrCALLY THREADED NUT REMOVAL TOOL. DESCRIPTION This application refers to a ranee of socket tools constructed

preferably of chromium steel, stellite#or@similar metals and alloys, for use primarily in the removal of old, damaged and possibly rounded-off hexagonal or square nut which have become seized onto their mating stud by corrosion or other chcmica action.

Preamble: A problem exists in such areas of activity as motor vehicle repair and maintenance, in that, with age, fastenings tend to become corroded toether, and attempts to remove them result in the rounding off of the flats provided to give purchase to a spanner or hexagonal socket and bar, thus making it virtually impossible to remove the nut by rotating it up its thread.

Current methods for the removal of seized fastenings when chemical penetrating and freeing agents have failed, include nut splitters, saws and a thermal torch, i.e. the nut is either cracked, sawn or burnt off. Among tie disadvantages of these removal procedures are that the mating siud is damaged or destroyed by the process. A further disadvantag is that none of these methods can be used easily in a restrieted spate such as might be found beneath an exhaust manifold or in a recess in an engine casing. This current invention proposes a sile means of achieving nut removal from any position where it is normally possible to use a socket and bar system, a box spanner or a ring spanner.Various thread pitches are envisioned for different applications.

Description: According to this present invention, there is provided a device for use as an attachment with a standard square section drive hexagonal socket spanner set or similar nut and bo!t removal system. This device may also be presented in the form of a box spanner, having a hole in the upper part for the introduction of a toriury bar, or in t6 > e configuration of a spanner, this description, however, for the sake of clarity, wi describe the device only in its manifestation as one tyc of attachment for a socket set, and wlii oh is so constructed as HELICALLY THREADED NUT REMOVAL TOOL.

have a square section mating orifice in its upper part to receive the turning bar of the socket set and, in its lower part, a hollow conical interior, threaded with a hardened helical cutting thread and having its operation opposite handed to the stud on which the nut is mounted. In most circumstances, this would mean having a left handed thread, although a right handed ersion is also envisioned.

In application, the action of unscrewing the nut would cause t"e helical thread to bite into the material thereof, bedding itself firmly into the metal, and increasing its grip as the turning action would make the thread drag the device don, forcing the nut ore firmly into the tapered interior, and thus increasing the bite of the thread and improving grip.

Operation:- The nut to be removed having become rounded such that no valid purchase may b obtained With either spar.ner, ring spanner, box spanner or socket spanner, the device is placed over the nut, and t!:c tors @sion bar of the socket spanner set is inserted inte the square section crifice in the upper part in the normal manner. The nut is then removed by turning the bar in the normal dirc@tion for removing the nut.

A specifie embodiment of the invention will now be described with specific reference to the accompanying drawings.

Figure 1. shows a vertical cross-section of a typical embodiment.

Figure 2. shows a series cf her zontal cross-sections based on fig. 1, at A - A, B - B, and C - C.

Figure 3i shows an exposed erthogonal vertical section, bored en fig. 1 Figure 4. illustratss the relative operating positions of the device, a turning me@ and a seized nut during operation. In this figure, i. is the deviqe, represents the turning means, iii. the seized nut, and the protruding stem cf the bol@ to which the flu s seized.

Operating procedure:- the turning means (ii) is inserted into the square section cavity (a) at the top end of the device. The assembly is then placed vertically over the seized nut (iii) and rotated, causing the cutting thread (b) to bed itself into the nut, driving the device further down onto the nut, jamming it further into the taper and providing an extremely tight grip which will then enable the nut to be removed. Naturally, the smallest bore device which will fit the nut would be the size employed.

Claims

1. a means of removing fastenings which depend for their action upon rotation, and which have become seized or relatively unmovable.

2. a means of removing such seized fastenings, such that it is not necessary to damage the thread upon which the fastening is mounted.

3. a means by which an increased grip may be achieved upon such a fastening as a result of its resistance to turning.

4. a) a device having a conical or tapered hollow interior which is provided with a helical cutting thread.

b) a device as in the preceding claims which has a hardened internal cutting thread which may be either handed.

5. a device as in the preceding claims which is so constructed as to work in conjunction with and as an attachment for a socket spanner set, and which has a mating upper orifice to receive the torsion bar of the socket spanner set.

6. a device as in the preceding claims which is provided with external flats to accommodate a spanner.

7. a device as in the preceding claims which is provided with a through hole to accommodate a tommy bar.

8. a device as in the preceding claims which may be manufactured in a range of sizes to accommodate a range of stud sizes.

9. a device as in the preceding claims which is manufactured in a range of sizes to accommodate a range of drive, spanner or torsion/tommy bar sizes.

10. a device as in the preceding claims whose taper will permit it to be used on different sizes of stud.

11. a device as in claims 1, 2, 3, 4, 5, 8, 9 and 10, being of an extended length, and having a hollow cylindrical cavity between the tapered section and the socket for the turning member, such that an extended bolt may be comfortably accommodated.

12. a device as in the preceding claims which may be either an accessory to an established nut removal system or may be a tool in its own right, having a rotating means built in as an integral part of the device itself.