SE2050011A1 - Nut driver device and a method of tightening nuts - Google Patents

Abstract

The invention relates to a method and a tool (10) for entering a cap nut (21) for connecting a conduit (20) to a conduit connection (24), by friction, wherein the cap nut (21) comprises an axial opening (25) for receiving a first end of the conduit (20) to be connected, and wherein the tool comprises:- a connector (13) for connection to an output end of a nut runner (1),- at least one drive wheel (11, 12), which is rotatably connected to the connector (13), the at least one drive wheel having a circumferential surface (11a, 12a) adapted to screw a nut by friction contact between the circumferential surface (11a, 12a) of the at least one drive wheel (11, 12) and an outer surface (22) of the nut (21), and- a positioning device (16) for positioning the tool (10) with respect to the cap nut (21), the positioning device (16) having a support surface (16b) arranged to interact with the conduit (20) to be connected.

Description

NUT DRIVER DEVICE AND A METHOD OF TIGHTENING NUTS TECHNICAL FIELD The invention relates to a nut driver device and a method a method of tightening nuts.Specifically, the invention relates to a nut driver device that is adapted to tighten nuts arranged to connect a conduit to a conduit connection on e.g. a pipe, rai| or the like.BACKGROUND ln the automotive industry more and more operations of the production line areautomated. However, some assembly steps still need to be made by performed by hand of an operator.

For instance, a large number of nuts or bolts need to be fastened in the assembly of amotor of a vehicle, such as a car, truck or bus. Typically, such operation may beperformed by means of a pneumatic or electric handheld nut runner and therefore causesproblem to an operator. Some nuts or screws are however such arranged that theiraccessibility is limited and/or such that a nut runner may not be used. The entering andtightening of such nuts therefore often involves ergonomic hazards for the operator. Theergonomic problems for the operator are also worsened by the fact that one and thesame operator needs to perform several similar operations per workday or shift, such that repetitive strain injuries and the like may arise.

For the Well-being of production operators every improvement relating the ergonomics of an operator is sought for.

Specifically, it would be advantageous to achieve a device/method overcoming, or atleast alleviating, at least one or some of the drawbacks of the prior art. ln particular, it isdesired to improve the ergonomics for an operator With respect to the entering and tightening or releasing of nuts and bolts of limited access.

SUMMARY OF THE INVENTION lt is an object of the invention to provide a device/method for facilitating the entering and tightening of nuts, bolts and/or screw caps of limited access.

According to a first aspect the invention relates to a tool for entering a cap nut forconnecting a conduit to a conduit connection, by friction, wherein the cap nut comprisesan axial opening for receiving a first end of the conduit to be connected, and wherein the tool comprises: - a connector for connection to an output end of a nut runner, - at least one drive wheel, which is rotatably connected to the connector, the atleast one drive wheel having a circumferential surface adapted to screw a nut by frictioncontact between the circumferential surface of the at least one drive wheel and an outersurface of the nut, and - a positioning device for positioning the tool with respect to the cap nut, thepositioning device having a support surface arranged to interact with the conduit to be connected.

The inventive tool provides an advantageous manner of screwing or unscrewing nuts orbolts in confined spaces or where normal socket-bolt screwing is impeded for problemsrelated to ergonomics and/or accessibility. The invention is particularly advantageous for entering cap nuts arranged to connect a conduit to a conduit connection. ln embodiments of the invention the positioning device is shaped as a hook so as tocapture the conduit to be connected. A hook-shape provides a possibility of supporting the conduit in more than one direction during operation of the tool. ln embodiments of the invention the positioning device comprises a slit for receiving theconduit. The slit may comprise two parallel support surfaces configured to interact with the conduit from two opposed directions. ln embodiments of the invention the support surface is configured to interact with the conduit to be connected in more than one direction.

The possibility of supporting the conduit from more than one direction during the screwingor unscrewing of the nut is useful both because it helps position the active part of the tool,i.e. drive wheel(s) with respect to the nut, and because it helps positioning the conduit such that its connection rim will not interfere with the screwing or unscrewing. ln embodiments of the invention the positioning device is connected to at least one drivewheel via a centre part, and wherein the at least one drive wheel is rotatably arrangedwith respect to the centre part and rotatably connected to the connector through thecentre part, the connector and the at least one drive wheel being arranged on opposite sides of the centre part. ln embodiments of the invention the positioning device is releasably connected to thecentre part. This is advantageous it provides the possibility of exchanging the positioning device and hence make sure that a positioning device specifically adapted for the purpose may be used. Hence, the tool may comprise a plurality of exchangeable positioning devices, adapted for different conduit connections. ln embodiments of the invention a support is rigidly connected to the centre part via atleast one connective element, the support being arranged to be connected to a front end of the nut runner. ln embodiments of the invention two drive wheels are arranged, both drive wheels havinga circumferential surface adapted to screw a nut by simultaneous friction contact bet\Neenboth circumferential surfaces of the respective drive wheel and an outer surface of the nut.

The use of the two drive wheels may improve the friction connection between the tooland the nut to be screwed or unscrewed. Further, in contrast to a tool with a drive wheelthat rotates in the same direction as the output of the nut runner, the rotational direction of the nut will correspond to the direction of the output of the nut runner.

The two drive wheels are preferably friction connected to a main drive wheel which, in turn, is rotatably connected to the connector.

According to a second aspect the invention relates to a method for screwing orunscrewing a cap nut or the like by friction by means of a tool according to anyone of thepreceding claims, the method comprising: - connecting the connector of the tool to an output end of a nut runner, - positioning the positioning device of the tool into interaction with a conduit to beconnected or disconnected, - positioning the circumferential surface of the at least one drive wheel in contactwith an outer surface of the nut to be screwed or unscrewed and maintaining said contactas the nut runner is operated so as to screw or unscrew the nut by friction contactbetween the envelope surface of the at least one drive wheel and the outer surface of the nut.

The method represents an provides an advantageous manner of entering or unscrewingnuts or bolts in confined spaces or where normal socket-bolt screwing is impeded forproblems related to ergonomics and/or accessibility. The method is particularlyadvantageous for entering cap nuts arranged to connect a conduit to a conduit connection.

Other embodiments and advantages will be apparent from the detailed description and the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Below, specific embodiments of the invention will be described with reference to the appended drawings, of which; Fig. 1 shows a tool in accordance with a first embodiment of the invention, arranged on a nut runnerFig. 2 shows the tool in Fig. 1 in operation,Fig. 3 is a perspective front view of the tool in Fig. 1,Fig. 4 is a perspective back view of the tool in Fig. 1, Fig. 5 shows a tool in accordance with a second embodiment of the invention in operation,Fig. 6 is a perspective front view of the tool in Fig. 5, andFig. 7 is a perspective back view of the tool in Fig. 5.

DETAILED DESCRIPTION OF THE SHOWN EMBODIMENTS ln fig. 1 a tool 10 according to a first embodiment of the invention is shown arranged on anut runner 1. ln this specification a nut runner indicates any type of powered handheldtool adapted to provide a rotational torque adapted to screw and/or unscrew a nut, bolt, screw or other threaded fastener. lt may e.g. be a drilling tool. ln the shown embodiment, the nut runner 1 is an electric nut runner, which is powered bya battery 2. The inventive tool 10 may however of course be connected to any type of nutrunner, including pneumatic or hydraulic nut runners, or electric cable connected nut FUHHGFS.

The shown nut runner 1 comprises a handle 3 for holding the nut runner 1 and a trigger 6for activating the rotation of the output 5 of the nut runner 1. The output of the nut runner 1 is arranged at a front end 4 of the nut runner 1.

The invention relates to a tool 10 for entering a nut by friction. The embodiment shown in Fig. 1 comprises a connector 13 for connection to the output 5 of a nut runner 1 and a main drive wheel 11, which is rotatably connected to the connector 13. Two auxiliarydrive wheels 12 are friction connected to the main drive wheel 11. The main drive wheel11 has a friction envelope surface 11a and both auxiliary drive wheels 12 also have acircumferential surface 12a which is rough or otherwise provided to provide friction. Thecircumferential surfaces 12a of the auxiliary drive wheels 12 are adapted to screw a nutby simultaneous friction contact with an outer surface 22 of a cap nut 21, as i||ustrated inFig. 2.

The drive wheels may typically be made of rubber, or plastic or any other material having a friction adapted to provide a rotationa| movement by contact.

The tool 10 further comprises a positioning device 16 for positioning the tool 10 withrespect to the cap nut 21 to be screwed or unscrewed. The positioning device 16 has asupport surface 16b arranged to interact with a conduit 20, which is to be connected to a conduit connection 24 on a pipe 23.

Typically, the pipe 23 is a fuel rail in a motor arrangement, wherein the fuel rail isconnected to conduits 20, which are arranged to provide fuel from the pipe rail, via theconduits 20, to the individual valves of a motor. The invention is however of courseadapted to screw or unscrew nuts for connecting conduits on any type screw connections. ln the shown embodiment, the positioning device 16 is shaped as a hook so as to capturethe conduit 20 to be connected and support the same from below. The positioning device16 is not only useful to provide a proper position for the auxiliary drive wheels 12 withrespect to the cap nut 21. Further, it may be useful in positioning the conduit 20 in a non-stressed position with respect to the cap nut 21 connection by making sure that aconnection rim (not shown) of the conduit 20 will not hinder the screwing of the cap nut21.

As is apparent from Fig. 2 the cap nut 21 may preferably be of the type that includes anouter surface 22 in the form of a cylindrical portion. Such a cylindrical portion offers anadvantage with respect to the inventive tool as it increases the friction interactionbetween circumferential surfaces 12a of the auxiliary drive wheels 12 and the outer surface 22 of the cap nut 21. ln the shown embodiment, a conduit 20 is attached to a pipe 23 in the form of a rail. The rail is provided with a plurality of conduit connections 24. ln Figs. 3 and 4 the tool in accordance with the first embodiment in shown in perspective views from the its front and back, respectively. ln Fig. 3 it is specifically apparent how the main drive wheel 11 is in contact with theauxiliary drive wheels 12, such that their respective circumferential surfaces 11a and 12a,respectively, are in contact and such that a rotation of the main drive wheel 11 will drivethe auxiliary drive wheels 12 in the opposite direction as illustrated by the arrows RO andR1 in Fig. 3. ln Fig. 4 the connector 13, which is arranged to connect the output of the nut runner withthe main drive wheel 11 is illustrated. ln the shown embodiment the connector 13comprises a socket 13a for connection to an output end of a nut runner. The oppositeend of the connector 13, e.g. the output end 13b is rotatably connected to the main drive wheel 11. ln the figures it is apparent that the positioning device 16 is connected to the drive wheels11,12 via a centre part 19, wherein the drive wheels are rotatably arranged with respectto the centre part 19 and rotatably connected to the connector 13 through the centre part19. Typically, a shaft (not shown) extends through the centre part 19 and rotatablyconnects the connector 13 and the main drive wheel 11, which are arranged on opposite sides of the centre part 19, to each other.

Also visible in Figs. 3 and 4 is a support 14, which is rigidly connected to the centre part19 via connective elements 15. The support 14 is arranged to be connected to a front end4 of the nut runner 1. ln the shown embodiment the support is comprised of a ring-shaped member, the ring having an opening 17 at which it is possible to adapt thediameter of the ring. A screw 18 is in the shown embodiment arranged to control the sizeof the gap of the opening, i.e. the distance between the open ends of the support 14,wherein one open end of the support 14 comprises a thread for receiving the screwthread and the opposite open end of the support 14 comprises a bore with a seat forholding the screw head. The support 14 is advantageously adapted to fit any type of nutrunner and may therefore be specifically designed for a specific nut runner. lt does notneed to be ring-shaped. lnstead at may have any shape the fits a specific nut runner.Also, the support may be comprised of one or more attachment means for fixing thesupport to the nut runner, or to at least position or provide a support with respect to the nut runner.

The tool 10 is specifically advantageous for the connection of conduit ends to suchconnections. The method for screwing and unscrewing a cap nut 21 or the like by friction by means of the tool 10 may be performed in the following manner.

Firstly, the connector 13 of the tool is connected to an output end 5 of a nut runner 1. Theconnector 13 is hence preferably adapted to fit a standard nut runner output having e.g. apolygonal shape, or it may be provided with an adapter to fit a specific output of a nutrunner. lt may include a connection bit for connection to, e.g. insertion into, a chuck of a nut runner. ln another step, prior or subsequent to the step of connecting the connector 13 of the toolto the output end 5 of the nut runner 1, the positioning device 16 of the tool is positionedinto interaction with a conduit 20 to be connected or disconnected. ln the shownembodiment, in which the positioning device 16 is hook-shaped having an arc-shapedsupport surface 16b for interaction with the conduit 20, the positioning device 16 may bearranged to support the opposite side of the conduit 20 with respect to the position of thedrive wheels 12, i.e. from below in the drawings. The shown support surface 16b isconfigured to interact with the conduit 20 in more than one direction, e.g. from the side, from above, and/or from below.

Further, in order to achieve the desired screwing or unscrewing of the cap nut 21 thecircumferential surfaces 12a of at least one of the drive wheels 12 needs to be positionedin contact with an outer surface 22 of the nut 21 to be screwed or unscrewed. Thiscontact is subsequently maintained as the nut runner is operated so as to screw orunscrew the nut 21 by friction contact between the circumferential surfaces 12a of at least one of the auxiliary drive wheels 12 and the outer surface 22 of the nut 21. ln an optional step the support 14 is arranged to be connected to a front end 4 of the nutrunner 1. Such connecting may include attaching the support 14 to the nut runner 1 or positioning the support 14 in close interaction with a non-rotating part of the nut runner. ln the embodiment shown in Figs. 1-4, two auxiliary drive wheels 12 are arranged, bothdrive wheels having a friction envelope surface 12a adapted to screw a nut bysimultaneous friction contact between both envelope surfaces 12a of the respective drivewheel 12 and an outer surface 22 of the nut 21. The two drive wheels 12 are frictionconnected to the main drive wheel 11 which is rotatably connected to the connector 13.

This is however only a specific embodiment. ln Figs. 5-7, an alternative, second embodiment is shown. ln this embodiment, noauxiliary drive wheels are arranged. lnstead, A sole drive wheel, the main drive wheel 11,is arranged to screw a nut 21 by friction contact with the outer surface 22 of the nut 21.This embodiment is advantageous in a confined space as it may be made very slim ifneeded. The only |imitation in size is the width of the drive wheel 11 and the extension ofthe positioning device 16 adapted to interact with the conduit to be connected ordisconnected. The positioning device 16 may however be adapted to specific circumstances and may hence be made as minimalistic as possible.

Except for the configuration of the drive wheel 11, most features of the second embodiment are similar to the features of the first embodiment.

The positioning device 16 is however different. ln the first embodiment shown in Figs 1-4,the position device is hook-shaped and arranged as a separate part, which is fastened to the centre part 19. ln the second embodiment, the positioning device 16 is instead arranged as an integratedpart of the centre part 19. The positioning device 16 is arranged as a hook, but also, ithas a more compact construction with a somewhat shorter hook. ln this embodiment, thehook forms a slit 16a into which a conduit to be connected or disconnected may bereceived. The width of the slit 16a may preferably be arranged to a standard sizedconduit. The tool may also be provided with a number of different position devices, whichmay be releasably connected to the centre part 19 of the tool 10, each position device being adapted to a specific cap nut and/or a specific conduit or specific conduit size. ln the shown embodiment the slit 16a has two opposed parallel surfaces 16b, whichdefines the slit 16a. Further, as illustrated in Fig. 7, the slit 16a involves an adjoining wall16c that adjoins two parallel surfaces 16b and offers a possible support for the conduit ina third direction. lf the conduit is fully received into the slit 16a it may hence besimultaneously supported in three directions. Thereby, the position of the conduit 20 withrespect to cap nut 21 arranged to connect the conduit may be adjusted so as to notinterfere with the entering of the cap nut 21. Specifically, the position of the conduit 20may be adjusted by simply tilting the nut runner in any desired angle, without losing contact between the active drive wheel(s) and the nut..

Above, the invention has been described with reference to specific embodiments. Theinvention is however not limited to these embodiments. lt is obvious to a person skilled in the art that other embodiments are possible within the scope of the following claims.

Further, the features of the different embodiments may be combined in any feasible way, such that all possible combinations thereof are also covered by the invention.

Claims (2)

1. A tool (10) for entering a cap nut (21) for connecting a conduit (20) to a conduitconnection (24), by friction, wherein the cap nut (21) comprises an axial opening (25)for receiving a first end of the conduit (20) to be connected, and wherein the toolcomprises: - a connector (13) for connection to an output end of a nut runner (1), - at least one drive wheel (11, 12), which is rotatably connected to the connector(13), the at least one drive wheel having a circumferential surface (11a, 12a) adaptedto screw a nut by friction contact between the circumferential surface (11a, 12a) of theat least one drive wheel (11, 12) and an outer surface (22) of the nut (21), and - a positioning device (16) for positioning the tool (10) with respect to the cap nut(21), the positioning device (16) having a support surface (16b) arranged to interact with the conduit (20) to be connected. The tool (10) according to claim 1, wherein the positioning device (16) is shaped as a hook so as to capture the conduit (20) to be connected. The tool (10) according to claim 1, wherein the positioning device (16) comprises a slit (16a) for receiving the conduit (20). The tool (10) according to either of claims 2 or 3, wherein the support surface (16b) isconfigured to interact with the conduit (20) to be connected in more than one direction. The tool (10) according to claim 3, wherein slit (16a) comprises two parallel supportsurfaces (16b) configured to interact with the conduit (20) from two opposed directions. The tool (10) according to anyone of the preceding claims, wherein the positioningdevice (16) is connected to at least one drive wheel (11, 12) via a centre part (19),and wherein the at least one drive wheel (11, 12) is rotatably arranged with respect tothe centre part (19) and rotatably connected to the connector (13) through the centrepart (19), the connector (13) and the at least one drive wheel (11, 12) being arranged on opposite sides of the centre part. The tool (10) according to claim 6, wherein the positioning device (16) is releasably connected to the centre part (19). The tool (10) according to claim 7, wherein the tool comprises a plurality of exchangeable positioning devices (16), adapted for different conduit connections. 9. 10. 11. 1

2. 11 The tool (10) according to claim 6, 7 or 8, wherein a support (14) is rigidly connectedto the centre part (19) via at least one connective element (15), the support being arranged to be connected to a front end (4) of the nut runner (1). The tool (10) according to anyone of the preceding claims, wherein two drive wheels(12) are arranged, both drive wheels having a circumferential surface (12a) adaptedto screw a nut by simultaneous friction contact between both circumferential surfaces (12a) of the respective drive wheel (12) and an outer surface (22) of the nut (21). The tool (10) according to claim 10, wherein the two drive wheels (12) are frictionconnected to a main drive wheel (1 1) which is rotatably connected to the connector(13). A method for screwing and unscrewing a cap nut (21) or the like by friction by meansof a tool (10) according to anyone of the preceding claims, the method comprising: - connecting the connector (13) of the tool to an output end of a nut runner (1), - positioning the positioning device (16) of the tool (10) into interaction with aconduit (20) to be connected or disconnected, - positioning the circumferential surface (11a, 12a) of the at least one drive wheel(11, 12) in contact with an outer surface (22) of the nut (21) to be screwed orunscrewed and maintaining said contact as the nut runner is operated so as to screwor unscrew the nut (21) by friction contact between the envelope surface (11a, 12a) of the at least one drive wheel (11, 12) and the outer surface (22) of the nut (21).