GB2481962A - Nut extractor - Google Patents

Abstract

The nut extractor 1 includes a circumferential polygonal body 10 having an exterior surface 2 and an interior surface 3 about a central axis 4. The extractor has at least one orifice 5 between the exterior surface and the interior surface, through which a screw means 11 may be received therethrough. An engaging means 13 is slidably disposable adjacent the orifice, such that it is substantially diametrically opposite the orifice. In use, the engaging means and the screw means are adapted to firmly engage a portion of a nut or bolt 12 received therebetween. The screw means may have a pointed tip to allow it to dig into a rounded nut 12. A plate (15, Figure 2) may additionally be fitted onto the tip of the screw to allow the extractor to be used in unfastening undamaged bolts / nuts with planar flats. The extractor may be used for various purposes, including removal of threaded fasteners, stubborn nuts or bolts and rounded nuts or bolts. The extractor may also be used together with a wrench or spanner which engages its exterior surface.

Description

Nut Extractor The present invention relates to extraction tools. More particularly, but not exclusively, it relates to adjustable nut extractors suitable for use with spanners or wrenches.

Nut extractors are known and are often employed in plumbing, mechanical engineering and in various other skilled trades to remove nuts or threaded fasteners which may have become stuck (commonly known in the industry as stubborn nuts / bolts' ) and which refuse to disengage by use of conventional wrenches, spanners or pliers.

There are many different types of nut extractors. The most common extractors have some form of gripping mechanism that utilizes one or more of engaging means using adjustable jaws, teeth, springs, sockets or wedges and suchlike to enable them to firmly engage a stubborn nut or bolt that slips when grasped. Further, some have square drives for use with hand ratchets, impact wrenches, air ratchets, while others are provided with hexagonal "flats" for use with flat wrench, pliers and adjustable wrenches. Among the variations are the "interference fit" type extractors that are similar in size and shape to a socket, but has sharp spiral flutes on its inside (commonly known in the industry as symmetrical reverse spiral flutes), facing opposite in direction to the loosening direction. The spiral flute opening is smaller than the corresponding size bolt head or nut to be removed, as the remover is intended to be hammered or driven on -thus the interference fit. In use, the extractor is hammered' on, the spiral flutes such that it "dig into" the rounded off flats of a nut or bolt, in the opposite direction of loosening. Once securely fixed, a user can then use an open end or box end wrench to turn the remover, and therefore remove the stuck bolt or nut.

There are also "advanced camming type" extractors that work in a similar manner to a socket, such that they are dropped over the stripped bolt head or nut without the need to use a hammer, and then turned by a ratchet. These extractors works by having a set of steel cams inside the socket, which expand over and onto the flats of the bolt or nut. As the socket is turned, the cams are squeezed tighter and tighter into the flats of the nut or bolt, such that as more torque is applied, the harder the cams grip the flats of the nut or bolt.

One particular application for nut extractors include the removal of tap heads of water taps serving baths and sinks. In such an instance it is often desirable to unscrew the tap head using a spanner or wrench, but if this is worn, it becomes extremely difficult to do so. One reason for this is that that wrenches, and the nuts they are suppose to remove, have tolerances such that they are not usually manufactured to an exact dimension, as this would increase the manufacturing costs of such articles, leading to an expensive product. This means that each product usually has a tolerance range. For example since it is desirable for a V2" wrench to work on every 1⁄4." nut head, then theoretically, the smallest tolerance wrench (of 1⁄4." size) must be able to easily fit on the largest tolerance nut (of 1⁄4" size). The difficulty is that the largest tolerance wrench (of 1⁄4" size) does not always fit well on the smallest tolerance nut head, and will most likely fit loosely on the smallest tolerance nut head (of 1⁄4" size) -and even loosely on products made anywhere in between. If it is too loose, then there will be slippage occurring on the interface of the flats of the nuts and the jaws of a wrench, for example between the commonly hex sides of a nut and the grasp of the spanner, which makes it extremely difficult to unfasten. This slippage will over continued use result in gradual rounding of the corners of the nut, damaging it.

Further, another reason for stubborn nuts may be that nuts or bolts that have been painted over and left unchanged over many years can become stuck as a result of weather implements (warm temperature, humidity, etc) that may have caused corrosion due to mechanical damage in the threadings of the internal bore.

There are many devices that are designed to remove or unfasten stubborn bolts or threaded fasteners; US6598498B discloses an extractor that has an attachment end having an attachment means for connection to an extraction tool and a receiving end. The receiving end has an interior bore that angles inwardly towards the attachment end. The interior bore has a central axis having two arcuate grooves -curve radially and inwardly towards the central axis of the interior bore-that extend along the interior bore towards the attachment end forming sharp helical shaped ridges.

JP 7237054A discloses a bolt-nut clamping machine that has a wrench socket connected to an output shaft through a universal joint. It has a spiral slant face 17 and a precipice 18 connecting the lowest part and highest part of the slant face to each other and facing the opposite side to the clamping rotating direction of the wrench socket 5.

JP 900 1469A discloses a nut turning tool 10 having a cylindrical socket 11 to be inserted and fitted into a round nut 1. The inner circumferential face 1 la in the socket 11, has respective jaw parts 1 ib, which are engaged/removed with/from respective notch parts lb that project outwardly are formed on the outer circumferential face Ia of the round nut 1.

CN 2254025 Y discloses a spanner which can wrench the geometric surfaces of worn screw bolts. An inner hole of a close spanner or a socket spanner is made into a regular do-decagon, a round angle is arranged on an angle top, each side is arched, and an expanded M-shaped sharp tooth is arranged on each side. A shape tooth on an arched side of contiguous angles forms a far-near symmetrical mode with an angle.

DE 202005007853U1 discloses a socket bit having a square-shaped opening at the top that is joined to a complementary part of a wrench or ratchet and a hexagonal opening at its lower side that is attached to the screw or nut to be tightened or loosened. The opening 22 is slightly wider at the outer edge and is provided with a rounded recess 23 in each of the corners. A pointed projection 24 is positioned between each pair of corners for a better grip.

However, these disclosures are not ideally suited for removing nuts, bolts or threaded fasteners for a number of reasons. Firstly, a number of the extractors disclosed are designed specifically for rounded off nuts and not for use on nuts that have their flats in perfect undamaged order. Also, with frequent use, and if not lined up straight on the head while you are applying torque, the flutes or teeth on some of the extractors may be vulnerable to mechanical limitations in that it they may can crack, or break and wear off, and the whole tool will eventually require replacement. Also if the extractor is to be hammered onto a nut, it can cock or tilt to one side as it is being hammered on -thus causing more damage to the bolt head or nut, leaving it totally immoveable. A further problem is that the user may be required to slowly apply torque and press down hard enough to prevent slippage, and this can be quite strenuous. Also for the interference fit type, if the rounded bolt or nut is down inside a limited access hole -where the interference fit type can not reach, it may not be possible to use such devices to remove the stubborn nut. Much more importantly, because of the large range of sizes for bolts and nuts, most most such extractors will come in sets of 5 or so varying dimensions, and typical dimensions include 5/l6in, 10mm, 13mm, 1L'l6in and 3/4in, necessitating the need to buy a number of articles for a whole range of varying sizes, and if an extractor for one size is damaged, replacement usually requires buying the whole set, incurring further cost. A further problem is that most devices disclosed in the prior art are not adjustable and cannot be used on varying nut sizes, being vulnerable to encounter the same tolerance problems as those encountered by conventional spanners and wrenches. Finally, if replacing water taps, most "hammer on" devices will not be able to engage the tap head nut because the tap head s spindle would be in the way, and not allow such engagement, especially if the extractor is not a hollow type.

Accordingly, it would be desirable to have an extraction tool that overcomes one or more of the disadvantages and limitations described above and provides a more effective alternative that is economical to manufacture and purchase, and easy to use.

According to a first aspect of the present invention, there is provided an extractor comprising; a circumferential substantially polygonal body having an exterior surface and an interior surface about a central axis; the extractor being provided with at least one orifice means between the exterior surface and the interior surface, through which a screw means may be received therethrough; the extractor being further provided with an engaging means slidably disposable adjacent the orifice means, such that it is substantially diametrically opposite the orifice means, wherein, in use, the engaging means and the screw means are adapted to firmly engage a portion of a nut or bolt received therebetween.

Preferably, the extractor body comprises a substantially hollow polygon.

Advantageously the extractor body comprises a partially hollow polygon.

Preferably, the extractor body is adapted to be used with a conventional spanner or wrench.

Advantageously, the extractor body is adapted to cooperate with other suitable plumbing tools such as pliers.

Preferably, extractor body is substantially hexagonal.

Advantageously the extractor body is substantially octagonal.

Optionall)c the extractor body is substantially circular.

The extractor body may be any suitable shape, and may comprise at least two halves for clamping around a nut.

Preferably, the orifice means comprises at least one threaded bore.

Advantageously the orifice means may comprises at least one non-threaded bore.

Optionally the orifice means may comprise a partially threaded bore.

Preferably, the orifice means is adapted to receive the screw means.

Advantageously, the orifice means is adapted to securely receive the screw means, whereby when fully inserted, the screw means remains immoveable, but by unscrewing.

The screw means may be adapted to be securely driven into the orifice means so as to be locked within the orifice means.

Preferably, the screw means may comprise at least one dimensional bolt.

Advantageously, the screw means may comprise a threaded bolt.

Optionally, the screw means may comprise a non-threaded bolt.

Preferably the screw means has a proximal end and a distal end.

Advantageously, the screw means is provided with a screw head disposed at the proximal end.

Preferably, the screw means is provided with an engaging means disposable at the distal end.

The distal end of the screw means may be the tip of the screw means.

Advantageously the engaging means of the screw means is adapted to cooperatively grasp a nut or bolt against the engaging means of the extractor body therebetween. The engaging means of the screw means and the engaging means of the extractor body may sandwich' a nut or bolt between their members.

Preferably the extractors engaging means comprises a removable dimensional member, that is slidably fitted within a crevice of the interior surface of the extractor.

Advantageously, the extractors engaging means may comprise a substantially cuboid plate, for example a generally rectangular or square bit' that fits within the crevice of the interior surface of the extractor.

The extractors engaging means may comprise a dimensional member, that is slidably fixed within the crevice of the interior surface of the extractor. The extractors engaging means may comprise a non removable section of the interior surface of the extractor.

Preferably the engaging means of the extractor is provided with one or more teeth or arcuate grooves on a first planar face.

Advantageously, the teeth or grooves may form a set of ribbed ridges protruding outwardly of the internal surface of the extractor.

Alternatively, the teeth or grooves may form a set of ribbed ridges facing inwardly of the internal surface of the extractor.

Preferably, the engaging means is provided with a substantially flat side on a second planar face.

Advantageously, the engaging means is adapted to fit firmly within the crevice of the interior surface of the extractor.

According to a second aspect of the present invention, there is provided a method of using an extractor, comprising providing an extractor as described in the first aspect above, and undertaking the steps of firmly securing the extractor onto a nut or bolt and using a wrench or spanner to apply torque to the extractor to disengage the nut An embodiment of the present invention will now be more particularly described by way of example, and with reference to the figure of the accompanying drawings, in which: Figure 1 is a top elevation of' the present invention showing the arrangement of the extractor, the first engaging means and the screw means.

Figure 2 is top elevation of the present invention showing, in use, the position of the extractors engaging means and the screw means' engaging means.

Figure 3 is a perspective view of the engaging means of the screw means described in the present invention.

Referring now to figure 1, an extractor 1 has a circumferential polygonal body 10 having an exterior surface 2 and an interior surface 3 about a central axis 4, The extractor 1 has at least one orifice 5 adjoining the exterior surface 2 and the interior surface 2. through which a screw or bolt 11 may be detachably received therethrough. Further, the extractor has an engaging means 13 slidably disposable adjacent the orifice 5, such that it is substantially diametrically opposite the orifice 5, wherein the engaging means 13 and the screw 11 are adapted to flrthly engage a portion of a nut 12 received therebetween, The screw 11 may be pointed to allow it to dig into the rounded nut 12, which is to be enganged.

In a preferred embodiment, the extractor 1 comprises a substantially hollow polygon that is shaped like a nut. However, it will be appreciated by a skilled person in the field that the extractor body may comprise any cooperate shape such as hexagonal or octagonal so as to be suitable for use with different types of spanners, wrenches and other suitable fastening plumbing tools. Further, the extractor 1 may comprise at least two halves' (not shown) pivoted against each other, for clamping or enveloping around a nut. This is particularly important where the rounded nut to be unfastened surrounds a tube or shaft, in the middle of a pipe with no suitable open ends' for mounting the extractor through. Further, engaging means 13 is adapted to cooperatively grasp a nut 12 against the screw 11 therebetween. The engaging means 13 helps in effectively sandwiching' the nut 12 or bolt between the screw 11 and the engaging means 13. Preferably, the engaging means 13 is slidably fitted within a crevice 6 of the interior surface 3. The engaging means 13 may comprise a rectangular or square bit' that fits within the crevice 6 of the interior surface 3. This is important because it means that the engaging means 5 may comprise a dimensional member, that is slidably fixed within the crevice 6 of the interior surface 3 and can be turned around (back to front), enabling the extractor 1 to be used on a normal nuts that are in undamaged condition. In a different embodiment, the engaging means 13 may be a non removable section of the interior surface 3 of the extractor 1. Further, the engaging means 13 is provided with one ol. more teeth or arcuate grooves 14 on a first planar face. This is important because the teeth or grooves 14 form a set of ribbed ridges protruding outwardly of the internal surface 3 of the extractor, in use such teeth dig and securely grasp a rounded nut 12. Alternatively, the teeth or grooves 14 may form a set of ribbed ridges facing inwardly of the internal surface 3 of the extractor 1. This enables the tool to be used for effectively grasping both damaged and undamaged nuts, by turning around the engaging means 13.

Referring now to figure 2, the orifice 5 comprise a threaded bore, through which the screw 11 may be driven. However the orifice 5 may be a non-threaded bore adapted to securely receive a non threaded screw or stud by a locking mechanism such as a lock spring and the like. The importance of this is that the orifice 5 is adapted to secure the screw from being withdrawn except by unscrewing or unlocking of the spring lock.

The screw 11 is provided with an engaging means 15 detachably disposable at the tip of the screw 11.

This is important because the screw's engaging means 15 cooperatively grasp a nut 12 against the engaging means 13 of the extractor body therebetween. Further, if the engaging means 13 is turned around and fixed within the crevice 6 with the teeth or grooves 14 facing inwardly as shown in figure 2, then the engaging means 15 of the screw means and the engaging means 13 of the extractor body sandwiches' can sandwich an undamaged nut 12 or bolt between their members, without digging into it and damaging it. The engaging means 15 (figure 3) may be provided with a small tight fitting bore to enable it to be securely fastened to the tip of the screw 11 ( figure 1 & 2) The extractor may be formed from rigid metal or rigid plastics material. However, it will be appreciated that other suitable tensile material may be used.

In a preferred embodiment, the teeth or grooves forming the ridges may be made by laser cutting.

Having described and illustrated the principles of the invention with reference to a preferred embodiment thereof, it will be apparent that the invention can be modified in arrangement and detail without departing from such principles. Accordingly, in view of the many possible embodiments to which the principles may be put, it should be noted that the detailed embodiments are illustrative only and should not be taken as limiting the scope of the invention. qlm