In one mode of operation the present invention relates to an extension arm for a spanner or the like, and in particular, to such an extension device for operative transmission of rotation movement of a nut, bolt, socket or the like, from a remote distance.

Description of the Prior Art It is often necessary to use tools in relatively inaccessible locations. Tools of many varying shapes and sizes are currently commercially available, such that a tradesman or other user is able to select a tool which is most appropriate to use in the circumstances for example, tools such as screwdrivers, sockets or wrenches, are provided with long or short handles.

The problems remains that whilst tools themselves might be provided in varying sizes in order to make it easier to place the tool in locations which are difficult to access, there is a need for a tool which, in at least one mode of operation, can extend the effect of existing tools.

Certain kinds of extension arms are already known including those disclosed in US3,987,691 (Savage), US4,374,480 (Diaz) and US5,732,605 (Mann). These tools, however, have limitations in that they are operable in only one mode of operation and, even in that mode, are not adapted to impart a turns ratio, and hence a torque ratio, of other

than 1: 1 thereby limiting their effectiveness in practical use.

It is an object of the present invention to overcome or ameliorate one or more of the abovementioned problems.

In particular forms the multifunction wrench aid seeks to address or ameliorate the problems by providing the ability to operate in more than one mode.

In a particular form the invention seeks to provide a tool which may be used effectively as an extension arm device for a spanner for rotating nuts, bolts, sockets or the like, provided in inaccessible locations.

Summary of the Invention Accordingly, in one broad form, the present invention provides an extension arm device for a spanner or the like, having: drive means at substantially a first end thereof to receive said spanner or like device; and, driven means at substantially a second end thereof adapted to engage a nut, bolt, socket or the like; whereby, in use, said spanner is received by said first end of said device and is rotated such that movement is operatively transmitted to rotate said nut, bolt, socket or the like.

Preferably, the device further has a plurality of gears operatively connected between said drive means and said driven means.

Also preferably, the device may utilise any desirable gearing ratio, including 1: 1 gearing ratio, or larger or smaller gears.

In this form, preferably, at least one of said gears is a circular gear.

Also, however, preferably, the device may be embodied wherein at least one of said gears is a worm gear, a planetary gear and/or a non-circular such as an elliptical gear.

Preferably, the device further has a chain or like device connected between sprockets provided on said drive means and said driven means.

Preferably, said device is a substantially longitudinal straight device.

In a preferred form, said device is provided with at least one bend, corner or curve therein.

In another preferred embodiment, said device is provided with a differential means therein.

In a preferred form, the device further comprises a ratchet device.

Preferably, a locking pin may be engaged with said drive means to render said drive means inoperative, such that said first end of said spanner may be rotated to effect rotation of said nut, bolt, spanner or the like connected to said second end of said device.

In a preferred embodiment, said driven means is disengageable from said device.

Preferably, said first end of said drive means is adapted to receive an extension arm via a male or female socket such that said drive means may be operated from a remote location.

Preferably, the device is constructed of a plurality of said devices may be interlinked.

In a further broad form of the invention there is provided a multifunction wrench aid comprising, in combination, a wrench and wrench extension arm assembly, said aid comprising a drive end spaced a predetermined distance

from a driven end; said drive end incorporating head engagement means for releasably engaging a peripheral portion of a nut or bolt or the like; said driven end incorporating driver engagement means for releasably engaging a drive device such as a wrench or socket driver; said driven end further incorporating support arm engagement means for releasable, non-pivotable, reception of a support arm whereby, in use, said support arm is engaged in non- pivotable manner by said support arm engagement means and a torque is applied to said driven end by said drive device for transmission over said predetermined distance to said drive end and is applied to said peripheral portion of said nut or bolt or the like by said head engagement means and whereby turning moment induced in said wrench aid by said torque is counter-balanced by application of a counter-torque applied via said support arm.

In a further broad form of the invention there is provided a multifunction wrench aid, said aid including a first working end spaced a predetermined distance from a second working end; said first working end incorporating first engagement means for releasably engaging at least one of a drive device or a driven device; said second working end engaging at least one of a drive device or a driven device; at least one of said first working end or said second working end further incorporating support arm engagement means for releasable, non-pivotable, reception of a support arm whereby, in use, said support arm is engaged in non-pivotable manner by said support arm engagement means and a torque is applied to one of said first or second working end by said drive device for transmission of said torque over said predetermined distance by rotation translocation means to the

other of said first or second working end for application of a said torque to said driven device and whereby, in use, turning moment induced in said wrench aid by said torque can be counter-balanced by application of a counter-moment applied via said support arm.

In yet a further broad form of the invention there is provided a multifunction wrench aid, said aid including a first working end spaced a predetermined distance from a second working end; said wrench aid further including rotation translocation means interconnecting said first working end to said second working end; said first working end incorporating first engagement means for releasably engaging at least one of a drive device or a driven device; said second working end incorporating second engagement means for releasably engaging at least one of a drive device or a driven device; at least one of said first working end or said second working end further incorporating support arm engagement means for releasable, non-pivotable, reception of a support arm whereby, in use, said support arm is engaged in non-pivotable manner by said support arm engagement means and whereby a torque which is applied to one of said first or second working end by said drive device is transmitted over said predetermined distance by said rotation translocation means to the other of said first or second working end for application of said torque to said driven device whereby, in use, turning moment induced in said wrench aid by application of said torque can be counter-balanced by application of a counter-moment applied via said support arm.

Preferably at least one of said first working end or said second working end further incorporating support arm

engagement means for releasable, non-pivotable, reception of a support arm whereby, in use, said support arm is engaged in non-pivotable manner by said support arm engagement means whereby, in use, turning moment induced in said wrench aid by application of said torque can be counter-balanced by application of a counter-moment applied via said support arm.

Preferably said first engagement means includes means for engaging both a drive device and a driven device.

Preferably said second engagement means includes means for engaging both a drive device and a driven device.

Preferably said first engagement means includes means for engaging a drive device.

Preferably said second engagement means includes means for engaging a driven device.

Preferably said drive device comprises a wrench or socket driver.

Preferably said driven device comprises a head portion of a nut or bolt or the like.

Preferably said support arm engagement means comprises a stub or socket.

Preferably said predetermined distance lies in the range lcm to lm.

Preferably said rotation translocation means comprises a plurality of gears intermeshed in series over said predetermined distance.

Preferably said means for engaging both a drive device and a driven device comprises a walled aperture adapted to receive a drive rod therein, said drive rod adapted to be engaged by a spanner, socket or the like for urging rotation of means for engaging both a drive device and a driven device.

Preferably said means for engaging both a drive device and a

driven device comprises a socket and drive rod mounted on a common axis.

Preferably said multifunction wrench aid is adapted to operate in a first mode wherein said first working end engages a drive device and said second working end engages a driven device; said multifunction wrench aid adapted to work in a second mode wherein said first working end engages a driven device and said second working end engages a drive device.

Preferably said rotation translation means includes turns ratio variation means whereby a turns ratio of other than 1: 1 is achieved between said first engagement means and said second engagement means.

Preferably said turns ratio variation means introduces a turns ratio in the range 5: 1 to 2: 1 between said first engagement means and said second engagement means.

Preferably said turns ratio variation means introduces a turns ratio between said first engagement means and said second engagement means of approximately 3: 1.

Preferably said wrench aid incorporates releasable locking means whereby said wrench aid is operable as a wrench when said locking means causes said rotation translocation means to be locked against rotation.

Preferably said rotation translocation means comprises a gear train comprised of a plurality of intermeshed gears.

Preferably said rotation translocation means comprises a worm drive.

Preferably said rotation translocation means comprises a chain drive.

Preferably said rotation translocation means incorporates a one way clutch thereby to permit said multifunction wrench aid to operate in a mode whereby at least one of either said

first engagement means or said second engagement means is rotatable in only one direction.

Preferably said rotation translocation means includes a planetary gear system.

In a further broad form of the invention there is provided a method of accessing the head of a nut, bolt or the like comprising applying a first end of the extension arm device to said head and applying a spanner or the like to said second end of said extension arm device thereby to cause rotation of said head.

In yet a further broad form of the invention there is provided a method of accessing the head of a nut, bolt or the like comprising applying a first end of the multifunction wrench aid to said head and applying a spanner or the like to said second end of said multifunction wrench aid thereby to cause rotation of said head.

Brief Description of the Drawings The present invention will become more fully understood from the following detailed description of preferred but non- limiting embodiments thereof, described in connection with the accompanying drawings, wherein: Fig. 1 illustrates, in Figs. l (a) and l (b) respectively, typical plan and elevation views of the device in accordance with the present invention; Fig. 2 illustrates the device of the present invention comprising a plurality of circular gears; Fig. 3 shows an arrangement of the present invention using planetary gears; Fig. 4 illustrates a plan view of the device showing use of multiple planetary gears; Fig. 5 illustrates an elevational view of a preferred

arrangement of the invention wherein the driven mechanism is detachable; Fig. 6 illustrates yet a further embodiment of the invention; Fig. 7 illustrates an embodiment of the invention which uses a chain drive; Fig. 8 illustrates another embodiment of the invention incorporating a locking pin; Fig. 9 illustrates, in Figs. 9 (a), 9 (b) and 9 (c), a sectional cut-away view, a plan view, and a side elevational view of an alternative embodiment of the device in accordance with the present invention; Fig. 10 illustrates, in Figs. 10 (a), 10 (b) and 10 (c), a sectional cut-away view, a plan view and a side elevational view of an embodiment showing the provision of a cogged socket insert; Fig. 11-in Figs. 11A, 11B illustrates a wrench aid according to a further embodiment of the invention usable in two modes; Fig. 12 illustrates a wrench aid according to a further embodiment of the invention usable in a first mode which is common to the wrench aid of Fig. 11 and also in a further mode which is different from the wrench aid of Fig. 11; Fig. 13A, B illustrates a further embodiment of the wrench aid incorporating a worm drive; Fig. 14 illustrates a further embodiment of the wrench aid which incorporates a one way clutch providing a further mode of operation; Fig. 15 illustrates the use of two or more wrench aids of the invention connected in series.

Fig. 16 is a top view, partly sectioned and partly diagrammatic of an extension tool according to a further embodiment of the invention; Figs. 17A, B illustrate details of a ratchet mechanism forming part of the extension tool of Fig. 16; Fig. 18 illustrates further views of the ratchet mechanism of Fig. 16 and a gear with which it interacts; Fig. 19A, B, C illustrates a wrench aid according to a further embodiment of the invention; and Fig. 20A, B, C, D illustrates in detail some of the components of the wrench aid of Fig. 19A, B, C.

Detailed Description of Preferred Embodiments Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated.

As shown in Figs. 1 and 2, there is provided a substantially elongate extension arm device for a spanner, generally designated by the numeral 1. The device comprises a drive means at substantially one end of the device 1, and a driven means 3 at a second end. The drive means is adapted to receive a spanner or like device, and the driven means is adapted to engage a nut, bolt, socket or the like. In use, the spanner is received by the first end, and operatively engaged in the drive means 2, such that, when the spanner is rotated, movement is operatively transmitted via an arrangement of gears, a chain drive, or the like, to rotate a nut, bolt or socket, which is operatively connected to the driven means 3 at the second end of the device 1 As shown in Figs. 1 and 2, the device of the present invention 1 preferably comprises a plurality of gears, for instance, circular gears, generally designated by the numeral

4. Whilst circular gears are shown in Figs. 1 and 2, any other form of gears may alternatively be provided, such as planetary gears 5, such as shown in Fig. 3, or any other non- circular gears, such as elliptical gears and the like. Other types of gear arrangements, such as worm gears 6, may also be utilised, such as might be used in the embodiment of Fig. 5, for transmittal of the rotating movement into a different plane.

Fig. 4 illustrates an extension arm device 20 according to a further embodiment of the invention which possesses certain particular advantages as a result of use of two planetary gear arrangements together with making provision for utilising an adapter for driving gears located midway along the length of the extension arm device 20.

Specifically, extension arm device 20 has a first working end 21 and a second working end 22 housed within an elongate transmission arm 23. First working end 21 includes a first planetary gear providing a first turns ratio between first socket adapter 25 and first toothed gear 26.

Second working end 22 includes a second planetary gear providing a second turns ratio between second socket adapter 28 and second toothed gear 29.

The first tooth gear 26 is drivingly interconnected with second toothed gear 29 by means of an intermeshed gear train comprising toothed gears 4A, 4B, 4C as illustrated in Fig. 4.

In this instance gear 4C includes a third socket adapter 30 whereby, in use, a user has a choice of three separate socket adapters, namely adapters 25,28 or 30 to utilise for attachment of a driving device thereto and also has a choice of the same three socket adapters for engagement with a driven device.

The end result of this arrangement is that the user may

select from a relatively wide variety of turns ratios and hence torque ratios as between various ones of the three socket adapters 25,28,30. As to be discussed in respect of later embodiments of the device of the invention different ones of the socket adapters can be utilised for engagement of a driven device at different times, if necessary by reorienting the extension arm device 20 so that, for example, a first socket adapter may be used for initial loosening of a bolt head, being the driven device and then the third socket adapter could be used for subsequent, rapid rotation for removal of the driven device.

Extension arm device 20 can additionally include support arm engagement means at either end, as illustrated, in the form of stubs 31,32 for non-pivotable receipt of a support arm (not shown) for use in resisting turning moment induced in the elongate transmission arm 23 during use of the extension arm device 20. The use and purpose of a support arm is described elsewhere in this specification with reference to other embodiments of the invention.

Fig. 6 illustrates a further embodiment of the extension arm having a bulbous housing 114 attached to one end of a narrow, elongate transmission arm 101. This embodiment incorporates a cone drive cog 10 driven by worm drive 11 which, in turn, is driven by shaft 12 via ratchet drive 13 as generally illustrated in Fig. 6.

In the embodiments of both Fig. 6 and Fig. 7 a walled aperture 14 is utilised as a means of interconnecting the extension arm to a driven device. The walled aperture 14 is adapted to receive a socket drive within it or a rod which, in turn, can engage a driving or driven device.

An alternative form of the invention is shown in Fig. 7, wherein a chain drive is used instead of a plurality of

circular gears, for transmittal of the force between a drive member 2 and a driven member 3, via the chain 7. The various embodiments shown in the drawings, show the device as a substantially longitudinal elongate straight device. It will, however, be appreciated that the gear arrangements, such as shown in Fig. 2, need not necessarily be provided in a straight line, but the device could be embodied in a curved or bent shape. It will also be appreciated that a plurality of identical gears, such as shown in Fig. 2, need not be provided, but a differential means could be included to effect transfer of the torque in different desired manners.

It will also be appreciated that it may be useful to incorporate a ratchet device with an appropriate pull, such that movement in only one direction may be effected.

The embodiment of Fig. 8 illustrates the provision of a locking pin 8 into at least one of the gears, such that movement of the gears may be prevented. In such an embodiment, the end 2 of the device may be gripped by the hand and used as a wrench to rotate the driven end 3, to effect rotation of a nut, bolt or spanner connected to the driven end 3 of the device.

Fig. 5 illustrates an embodiment wherein one end of the device, in this case the driven end 3, may be disengageable from the remainder of the device. Different types of end 3 may then be adapted to fit different types of nut, bolt, socket or the like.

It will also be appreciated that a plurality of device 1 may be interlinked with another device 1 using an appropriate engaging piece, provided there between, enabling the device to be used for rotating nut, bolts, sockets or the like, in a varying range of inaccessible locations.

In Fig. 9 is illustrated an alternative embodiment of

the device according to the present invention. Fig. 9 (a) illustrates a sectional cut-away view of the device, Fig.

9 (b) shows a plan view, and Fig. 9 (c) details a side elevational view. The embodiment of Fig. 9 indicates that a gear ratio of other than 1: 1 may be provided to alter the force or torque required to be physically exerted to operate the device. The particular embodiment shows seven 14 teeth cogs, one 26 teeth cog and one 9 teeth cog. The embodiment also illustrates the alternative use of male or female connectors, which may be selected, depending upon requirements to provide alternate modes of operation. The provision of female sockets enables the addition of a male connector and/or an extension arm as desired, enabling any desired torque to be provided.

In Fig. 10 is illustrated yet a further alternative embodiment of the device in accordance with the present invention. Fig. 10 (a) illustrates a sectional cut-away view of the device, Fig. 10 (b) shows a plan view, and Fig. 10 (c) details a side elevational view. The embodiment of Fig. 10 illustrates the use of other than 1: 1 gear ratios, and, the provision of cogged socket inserts 15, allowing a cogged socket to be adapted to the device for the purpose of enabling torque to be provided thereto, or, to allow an extension piece to be connected thereto.

FURTHER EMBODIMENTS With reference to Fig. 11 a wrench aid 100 according to a further embodiment of the invention is illustrated in plan view. The wrench aid 100 is of substantially similar construction to the extension arm device illustrated and described with reference to Fig. 10 earlier.

In this instance the wrench aid is specifically adapted

for operation from either end as to be described with reference to Figs. 11A and 11B.

The wrench aid 100 comprises a narrow, elongate transmission arm 101 having, at a first end 102 support arm engagement means in the form, in this instance, of stub 103.

Also at first end 102 is located a first engagement means in the form, in this instance, of combined spanner stub and socket 104 shown in greater detail in the inset of Fig. 11A.

The combined spanner stub and socket 104 comprises a spanner stub 105 and a socket 106, each mounted at opposed ends of a common axis 107. The spanner stub 105 is adapted to receive the nut engaging aperture 108 of a spanner 109 for the purpose of imparting a torque to common axis 107. Socket 106 includes a head receptor cavity 110 for engagement upon a head 111 of a nut 112 or the head of a socket wrench (not shown) or similar.

At a second end 113 of transmission arm 101 is located a bulbous housing 114 which incorporates a second engagement means in the form of a second combined spanner stub and socket 115 of substantially the same construction as the (first) combined spanner stub and socket 104 described above and wherein like components are numbered identically but include a suffix B. The bulbous housing 104 also includes a second support arm engagement means in the form of a second stub 116 adapted, as for first stub 103 for non-pivotable reception of a support arm 117.

In this instance the bulbous housing 114 accommodates on common axis 107B a large diameter gear 118 which has a diameter greater than that of gears 119 forming gear train 120 located within the narrow, elongate transmission arm 101.

In this instance the gears 119 of the gear train 120 are all of the same diameter including the gear mounted on common

axis 107 whereby 1: 1 torque transmission is effected from the combined spanner stub and socket 104 through to the second end 113 of transmission arm 101. At this point engagement of the gear train 120 with the large diameter gear 118 means that increased torque is applied to second common axis 107B and hence to head 111 of nut/screw 112 as compared with the torque applied by wrench 109 to common axis 107.

With reference to Fig. 11B the wrench aid 100 can be reversed or"end for ended"to operate in a second mode whereby decreased torque is applied to nut/screw 112 via common axis 107 as compared with the torque applied at common axis 107B. However, there will be an amplification of rotational speed of nut/screw 112 compared with the rotational speed of spanner 109.

In both instances a support arm 117 can be utilised to resist turning moment induced in the wrench aid 100 by the torque applied via wrench 109.

Fig. 12 illustrates an alternative embodiment of the invention similar in many respects to that of Fig. 11A and where like components are numbered as for Fig. 11A. In this instance the wrench aid 200 incorporates a locking pin 220 which is adapted, in a locking position, to prevent rotation of gear 119 nearest first end 102 thereby to convert the wrench aid into a wrench.

Fig. 13A, B illustrates a wrench aid 200 according to a further embodiment which has a construction substantially similar to that of the wrench aid 100 of Fig. 11 but, additionally, includes a worm drive 201 actuable by rotation of worm drive arm 202 via T wrench 203 or socket wrench 204 thereby to cause direct rotation of large diameter gear 218.

With reference to Fig. 14 yet a further embodiment of the invention is described comprising a wrench aid 300 having

a construction substantially similar to that described with reference to Fig. 11 but, additionally, including a one way clutch mechanism within bulbous housing 314.

In this instance the one way clutch has a construction as illustrated in the inset of Fig. 14.

If locking pin 320 is not engaged the wrench aid 300 acts as an extension arm. If locking pin 320 is engaged then the wrench aid acts as a socket driver or like device.

With reference to Fig. 15 the wrench aid of any of the previous embodiments such as, for example wrench aid 100 can be"daisy-chained"by serial engagement, as illustrated, when operating in extension arm mode thereby to provide access via a tortuous path to an otherwise inaccessible nut/screw.

With reference to Fig. 16 there is shown an extension arm 400 of the type described with reference to Fig. 11 except that, in place of the combined spanner stub and socket unit 104 at first end 102 there is incorporated an actuation arm 401 pivotably connected to a ratchet mechanism 402. The ratchet mechanism 402 is adapted to communicate torque in one direction only to first gear 403 of gear train 404 within transmission arm 405 for transmission to combined spanner stub and socket 406 located at second end 407 of arm 400.

The ratchet mechanism 402 is operated by applying a reciprocating motion to actuation arm 401 with the ratchet mechanism engaging first gear 403 for transmission of torque in only one direction.

In this instance the gear train 404 is sized so as to cause the rate of turns ratio to vary from 3: 1 with combined spanner stub and socket 406 rotating once for every three turns of first gear 403.

Fig. 17A shows a plan view of the hub 408 of the ratchet mechanism 402 and including views of retention bolts 409 and

pawls 410. Fig. 17B shows a side view of the hub 408.

Fig. 18 illustrates the hub 408 in place relative to driven 411 and shows the manner of engagement of the pawls 410 with tines 412 of the driven gear 411. The pawls 410 are biased to a return position by springs 413 and are arranged to engage with tines 412 only when rotated in one direction.

With reference to Figs. 19A, B, C there is illustrated a wrench aid 500 according to a further embodiment of the invention. This arrangement includes a gear train 120 within transmission arm 101 and additionally includes in bulbous housing 114 a one way clutch assembly 501 which incorporates wedges 502 biased by springs 503 so that in one direction of rotation the wedges lock inner hub 504 relative to toothed ring 505 and, in the other direction, free wheel relative to toothed ring 505.

The toothed ring 505 itself may be locked by sliding lock arm 506 in the direction of the arrow in Fig. 19A so as to engage a tooth of tooth ring 505.

Hence, in a first mode of operation the wrench aid 500 is operable as an extension arm in the manner previously described with lock arm 506 disengaged. When lock arm 506 is engaged the wrench aid 500 becomes a socket wrench. As for previous embodiments an extension arm 507 may be attached to resist turning moment of the transmission arm 101, in use.

Fig. 20A is a section view along line AA of Fig. 19C showing one of the gears 403 within the transmission arm 101.

Fig. 20B illustrates detail of the one way clutch assembly.

Fig. 20C illustrates an insert 508 for insertion within the hexagonal walled aperture 509 of the wrench aid 500 thereby to receive a square cross section rod (not shown) within square cross section aperture 510 located therewithin.

Fig. 20D illustrates an extension arm 507 having a square cross section working end 511 for insertion either in non-pivoting end aperture 512 of the wrench aid 500 or in the square cross section aperture 510 of the insert 508.

It will be appreciated that the present invention provides a unique device which may have numerous variations and modifications made thereto, depending on the particular use and application of the device. A plurality of sizes of nuts, bolts, sockets or the like may be engaged by having appropriate ends 3 on the device. A wide variety of lengths and angled devices may be provided to suit the particular inaccessible location.

All such variations and modifications which become apparent to persons skilled in the art should be considered to fall within the spirit and scope of the invention as broadly hereinbefore described.

Industrial Applicability Embodiments of the invention have particular application for providing extension of the action of commonly available tools such as spanners or torque wrenches and would find application in mechanical workshops adapted to service, for example, motor vehicles, trucks or other heavy vehicles.

The device is particularly appropriate as a useful tradesman or home handyman's tool for rotating nuts, bolts, sockets or the like in inaccessible locations.