GB2457578A

GB2457578A - Torque angle gauge

Info

Publication number: GB2457578A
Application number: GB0902663A
Authority: GB
Inventors: Mark Mccarthy
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-20
Filing date: 2009-02-18
Publication date: 2009-08-26
Anticipated expiration: 2029-02-18
Also published as: GB2457578A8; GB0803039D0; GB2457578B; GB0902663D0

Abstract

A torque angle gauge 6 comprises a means 8 for mounting the angle gauge between a tool and a fastening; a first full, or partial, disc 7 coaxially mounted on the mounting means, said disc having a first light source 11, such as a laser, positioned to emit a focused light beam radially outwards to project a first reference indicator; a second light source 9 positioned to emit a focused light beam radially outwards to project a second reference indicator, the second light source being rotatably mounted relative to the first light source; and a display means having a plurality of angular gradations to display the angular difference between the reference indicators projected by the first and second light sources. An embodiment of the invention employing a single light source is also disclosed (figure 6).

Description

TORQUE ANGLE GAUGE

Field of the Invention

The present invention relates to a gauge tool, and in particular a torque angle gauge for use in the accurate tightening of fastenings in, for example, vehicle engines.

Background of the Invention

For the fastenings used in some vehicles, the vehicle manufacturers specify both torque and angle settings. This is to ensure that the fastenings are not over-or under-tightened. A torque wrench is used to apply a specified amount of torque to a fastening, such as a nut or a bolt. A torque angle gauge can be used to ensure that the correct angle setting is applied to the fastening, thus complying with the manufacture's specifications.

In order for the fastenings to be accurately tightened to the manufacturer's specification a two-stage process in carried out. Firstly a standard torque wrench is used to tighten the fastening to the torque value specified by the manufacturer. Once the specified torque value has been applied, a torque angle gauge is used to ensure that the fastening is then tightened to the specified angle.

One example of a torque angle gauge of the prior art is shown in Figure 1, the gauge comprises a disc with incremental markings thereon which are distributed around the disc to represent the angles from 0 to 3600.

The torque angle gauge also has an indicator disc which is mounted relative to the marked disc. The indicator disc, which has a single marking thereon, is mounted so as to enable the indicator disc to be rotated relative to the marked disc. In this way the indicator disc can be set at a particular angular mark, thus enabling the user's desired angle of rotation to be displayed by the gauge. In use, the torque angle gauge is mounted between the fastening and the torque wrench, thus enabling the user to monitor the angle of torque applied by the wrench.

The main disadvantage with the known torque angle gauges is that the act of tightening a fastening with a wrench usually requires two hands, and can make it difficult to hold the gauge secure at the same time as the user tightens the fastening. Furthermore, whilst the user is tightening a fastening it is not uncommon for the display of the angle gauge to be partially or completely covered by the user's hand as the user seeks to get the best grip on the wrench, thus preventing the user from referring to the gauge without having to stop tightening the fastening.

Summary of the Invention

One aspect of the present invention provides a torque angle gauge comprising: a means for mounting the angle gauge between a tool and a fastening; a first full, or partial, disc coaxially mounted on the mounting means, said disc having a first light source positioned to emit a focused light beam radially outwards to project a first reference indicator; a second light source positioned to emit a focused light beam radially outwards to project a second reference indicator, the second light source being rotatably mounted relative to the first light source; and a display means having a plurality of angular gradations to display the angular difference between the reference indicators projected by the first and second light sources.

By projecting reference indicators away from the angle gauge itself the user can more clearly determine the angle of the rotation applied to the fastening without having to remove their hands.

It will be appreciated that a partial disc comprises a disc with a sector removed.

Preferably the torque angle gauge may further comprise a second full, or partial, disc coaxially mounted on the mounting means, said second disc being rotatable relative to the mounting means. Also the torque angle gauge may be arranged so that the second disc is smaller in diameter than the first disc. The second disc may have the second light source mounted thereon.

Alternatively the second light source may be rotatably mounted on the mounting means.

Preferably the mounting means may comprise a drive shaft engageabte at a first end thereof with a tool and at a second end thereof a fastening. In this way the gauge can be easily mounted between a wrench and a nut that is to be tightened, for example. Alternatively the mounting means may simply comprise an aperture located in the first disc. It will be appreciated that the shape of the aperture should be such as to ensure that the first disc cannot rotate relative to the tool and the fastening when the tool is worked.

Preferably the torque angle gauge may further comprise a locking means to lock the position of the second light source relative to the first light source. In this way the gauge can be used repeatably to apply a constant amount of torque to subsequent fasteners.

Preferably the locking means prevents the rotation of the second disc relative to the first disc. Alternatively the locking means prevents the rotation of the second light source relative to the mounting means.

Advantageously the light sources of the torque angle gauge are lasers.

Preferably the lasers will project a vertical letter box' or I' shaped beam rather that a single point beam. In this way the lasers can project a trail of light radiating outwards from the centre of the gauge, which greatly increases the user's ability to locate and monitor the reference indicators.

It may also be preferable that the focused light beam emitted by the first light source is distinguishable from the focused light beam emitted by the second light source. In this regard it is considered advantageous that the focused light beam emitted by the first light source is a different colour from the light beam emitted by the second light source. Another means of distinguishing the first focused light beam from the second focused light beam may be that the one of the focused light beams is constant and the other focused light beam is intermittent.

Preferably the torque angle gauge may have angular gradations located on the first disc. Alternatively, or additionally, the torque angle gauge may have angular gradations located on the second disc. The first disc of the torque angle gauge may be transparent. Alternatively, or additionally, the second disc may be transparent.

The present invention also provides a method of measuring the amount of angular torque applied to a fastening comprising the steps: attaching a torque angle gauge with two radially oriented light sources between a tool and a fastening; using the angular gradations present on the gauge, set the angle between the first and second light sources so that the angular difference between the reference indicators projected by the first and second light sources is equal to the required torque angle setting; locate the positions of the where the first and second reference indicators are cast; apply the necessary torque angle to the fastening by working the tool in the required rotational direction until the second light source projects the second reference indicator on the point that was originally hit by the first reference indicator.

The method may further comprise the step of locking the positions of the first and second light source relative to one another so that the same torque angle can be repeatably applied to multiple fastenings.

In a second aspect of the present invention a single light source for of the torque angle gauge is provided. The single light source torque angle gauge comprises: a means for mounting the angle gauge between a tool and a fastening; a disc coaxially mounted on the mounting means, said disc having a plurality of angular gradations located thereon; a light source positioned to emit a focused light beam radially outwards from the centre of the disc, said light source being rotatably mounted relative to the disc; biasing means to direct the light source to rotate in one direction relative to the disc; and a restricting member, lockable at any point on the disc to stop the rotation of the light source and ensure that the light source always returns to the same angular orientation relative to the disc.

Preferably the single light source torque angle gauge further comprises a second, fixed restricting member to prevent the biasing means being overstretched by the manual movement of the light source by a user.

It is appreciated that the preferable features discussed for one aspect on the invention may be readily adapted for use with the other aspects of the present invention.

Brief Description of the Drawings

In the drawings, which illustrate a preferred embodiment of the invention: Figure 1 shows an example of a torque angle gauge of the prior art; Figure 2 shows an elevation view of a first embodiment of the torque angle gauge of the present invention; Figure 3 shows a side view of the first embodiment of the present invention; Figure 4 shows an elevation view of a second embodiment of the torque angle gauge of the present invention; Figure 5 shows a side view of the second embodiment of the present invention; and Figure 6 shows the single light source torque angle gauge of the present invention.

Detailed Description of the Preferred Embodiments of the Invention Figure 1 shows an example of a commonly used torque angle gauge 1.

The torque angle gauge 1 comprises a main disc portion 2 with angular markings of 0 to 3600 printed at discrete intervals around the outer edge of the disc. A second, smaller disc 3 is mounted coaxially with the first disc and is rotatable relative to the first disc. The second disc 3 comprises a single indication arrow 4, which is directed radially outwards and can be aligned with any of the angular markings.

The torque angle gauge I further comprises a central hole 5. The central hole 5 allows the gauge to be fitted to tool, for example a torque wrench. The gauge is positioned between the wrench and the fastening (or fastening appropriate adaptor), typical examples of the fastenings used in vehicles are nuts and bolts.

In use, the user can set a target rotation angle that is to be applied to a fastening by rotating the second disc 3 relative to the first disc 2 to align the indication arrow 4 of the second disc with the corresponding angular marking on the first disc. When the wrench is worked to twist the fastening, the user holds the first disc 2 to ensure that it does not move. As the wrench applies rotation to the fastening, the second disc 3 is caused to rotate by the corresponding amount, thus enabling the user to monitor the angle of rotation applied and the target angle of rotation.

The torque angle gauge I of the prior art has a number of disadvantages, including the high likelihood of error due to loss of grip by the user during the application of a rotational force to a fastening. The angular markings on the gauge 1 can also be difficult to see while the user is in the process of applying a rotational force to a fastening.

Figures 2 and 3 show a torque angle gauge 6 according to a first embodiment of the present invention. The gauge 6 comprises a disc 7 fixedly mounted on a drive shaft 8. The disc 7 is mounted such that when the drive shaft 8 is rotated by a tool, such as a wrench, the disc 7 also rotates. The disc 7 is provided with a plurality of angular markings displaying the angles 0 to 3600 which are printed at discrete intervals around the outer edge of the disc 7. The skilled person will appreciate that the disc must be made from a durable material to enable it to survive the various stresses and strains placed upon it.

The drive shaft 8 is engageable at one end with a tool and at the other end with a fastening (or a fastening adapter), thus enabling the rotational force applied by a tool, such as a wrench, to be transmitted to the fastening.

The skilled man will appreciate the nature of the connections required at the ends of the drive shaft 8 to ensure the transmission of rotational force. The drive shaft 8 might suitably be made of a material with high torsional strength, such as metal. The skilled person will appreciate the metals which have the necessary qualities for use in the gauge.

The torque angle gauge 6 is provided with a first laser 11 and a second laser 9. Alternative light sources that are capable of providing a focused light beam will also be appreciated by the skilled man. The first laser 11 is mounted on the underside of the disc 7 and is positioned to emit a light beam radially outwards from the centre of the disc 7.

The second laser 9 is rotatably mounted on the drive shaft 8 so that is can be rotated relative to the disc 7 and thus the first laser 11. The nature of the means by which the second laser 9 is mounted on the drive shaft 8 will be appreciated by the skilled man, although one example may be by way of a collar 10 that encircles the drive shaft 7. Preferably the collar 10 may also comprise a locking means 12, which is lockable to stop the movement of the second laser 9 relative to the drive shaft 8(and thus the first laser 11).

In use, the torque angle gauge 6 is fitted, between a torque wrench and a fastening that is to be tightened, by way of the connections (not shown) on the ends of the drive shaft 8. The user then rotates the second laser 9 until the angle between the light beam of the second laser 9 and the light beam of the first laser 11 corresponds to that specified by the manufactures. The angular markings on the disc 7 ensure the accuracy of the angle. When the appropriate angle has been set, the user should observe where the second light beam hits a solid object, this location can be marked by the user in an appropriate way if necessary. Preferably the angle difference between the first and second lasers should be fixed by engaging the locking means 12.

Once the end point of the second laser beam has been noted, the user can proceed to apply the necessary rotational force to the fastening via the tool. As the drive shaft 8 rotates, thus imparting the torque on the fastening, the first laser 11 is rotated also. Once the beam emitted by the first laser 11 hits the same location on the solid object as the second laser beam did at the start of the process, the user can be sure that the necessary angle of rotation has been applied to the fastening.

An additional benefit of locking the second laser 9 relative to the first laser 11, is that the same angle of rotation can be consistently applied to multiple fastenings without having to rely on guess work.

Figures 4 and 5 show a torque angle gauge 13 according to a second embodiment of the present invention. The torque angle gauge 13 comprises most of the same components as the torque angle gauge 6 described in figures 2 and 3. However, rather than mounting the second laser 9 on the drive shaft 8 directly, the torque angle gauge 13 further comprises a second disc 14, upon which the second laser 9 is mounted. In order to provide the movement of the second laser 9 relative to the first laser 11, the second disc 14 is rotatable relative to the drive shaft 8. The second laser 9 is fixed to the second disc 14 at the same orientation as the previously described, i.e. so that the light beam emitted by the laser is directed radially outwards from the centre of the discs.

The second disc 14 is preferably transparent so that the angular markings on the first disc 7 can be viewed through the second disc 14. It is appreciated that alternative arrangements may be adopted, such as making the second disc 14 smaller in diameter than the first disc 7 to enable the angular markings to be clearly displayed.

The torque angle gauge 13 is used in essentially the same way as the torque angle gauge 6 described above. The main difference between the operation of the torque angle gauge of the first and second embodiments is that in the second embodiment the second disc 14 is rotated relative to the drive shaft 8 and thus the first disc 7. As with the first embodiment the angular difference between the first 11 and second lasers 9 can be locked by use of a locking means 15, which prevents the movement of the second disc 14 relative to the first disc 7.

By projecting the reference points to location distinct from the gauge itself the user can easily apply a consistent specified angular rotation to multiple fastenings without the need for exceptional skill.

It is appreciated that, whilst the above embodiments use one or more complete discs, an effective torque angle gauge can be constructed with an incomplete discs, i.e. discs with one or more sectors removed therefrom.

Figure 6 shows an alternative design of torque angle gauge 20 that makes use of a single light source to solve the problem addressed by the present invention. The light source 23, which is provided by a laser that projects a beam in a vertical letter box' or I' shape, casts a beam radially outwards across the disc 21 thus enabling the user to easily monitor the amount of angle already applied. The gauge 20 has a number of similar components to the other gauges 6, 13 of the present invention. The gauge 20 consists of a disc 21 mounted coaxially on a mounting means in the form of a drive shaft 22. The drive shaft 22 enables the gauge to be fitted between a tool and a fastening, such as a nut or a bolt.

The single light source 23 is rotatably mounted on the drive shaft 22 by a collar 24. The gauge 20 also has a biasing means, not shown, which is arranged to urge the light source 23 to rotate in a particular direction around the drive shaft 22. This direction my be clockwise or anti-clockwise. The biasing means of gauge 20 is arranged to bias the light source 23 to rotate in an anti-clockwise direction.

The disc 21 is provided with a restricting pin 25, which can be fixed on to the disc 21 at various points by inserting the pin 25 into one of the plurality of locating holes 26. Once located in a locating hole 26 the pin 25 blocks the biased rotation of the light source 21 around the drive shaft 22. It will be appreciated by the skilled man that the position at which the pin 25 is located will define the predetermined angle of torque being displayed by the gauge.

The disc 21 is further provided with a end limiting pin 27, which is provided to prevent the light source 21 being rotated beyond a certain point by the user. Over rotating the biased light source could damage the biasing means, which is not desirable. The disc 21 is marked with angular gradations from 0-360° in an anticlockwise direction around the disc.

In use, the user will set the angle of rotation to be applied by locating the restricting pin 25 in an appropriate locating hole 26, in the illustrated example this is at 90°. At rest, the light source will then project its beam radially at 900. The user then turns the tool, which is attached to the fastening via the gauge, whilst holding the gauge by the disc portion thereof, until the light source reaches the end limiting pin 27. This arrangement ensures that the user is able to replicate the angle of torque applied to each fastening.

It is appreciated that the other torque angle gauges of the present invention 6, 13 might also comprise a biasing means, pins 25, 27, and the vertical letter box' style of laser beam light source. It is also appreciated that the gauge of figure 6 may be further improved by providing a second light source similar to light source 23. The second light source would be fixed to the disc 21 so as to provide a constant reference for the end point of the rotation. This additional feature, as well as improving the ease with which a user can monitor the angles being applied, provides a further protection against over turning of the fastening.

Claims

CLAIMS1. A torque angle gauge comprising: a means for mounting the angle gauge between a tool and a fastening; a first full, or partial, disc coaxially mounted on the mounting means, said disc having a first light source positioned to emit a focused light beam radially outwards to project a first reference indicator; a second light source positioned to emit a focused light beam radially outwards to project a second reference indicator, the second light source being rotatably mounted relative to the first light source; and a display means having a plurality of angular gradations to display the angular difference between the reference indicators projected by the first and second light sources.
2. The torque angle gauge of claim 1, wherein the gauge further comprises a second full, or partial, disc coaxially mounted on the mounting means, said second disc being rotatable relative to the mounting means.
3. The torque angle gauge of claim 2, wherein the second disc is smaller in diameter than the first disc.
4. The torque angle gauge of claim 2 or 3, wherein the second light source is mounted on the second disc.
5. The torque angle gauge of any of claims 1, 2 or 3, wherein the second light source is rotatably mounted on the mounting means.
6. The torque angle gauge of any of the preceding claims, wherein the mounting means comprises a drive shaft engageable at a first end thereof with a tool and at a second end thereof a fastening.
7. The torque angle gauge of any of claims 1 to 6, wherein the mounting means comprises an aperture located in the first disc.
8. The torque angle gauge of any of the preceding claims, wherein the torque angle gauge further comprises a locking means to lock the position of the second light source relative to the first light source.
9. The torque angle gauge of claim 8, wherein the locking means prevents the rotation of the second disc relative to the first disc.
10. The torque angle gauge of claim 8, wherein the locking means prevents the rotation of the second light source relative to the mounting means.
11. The torque angle gauge of any of the preceding claims, wherein the first and second light sources are lasers, that preferably project a letter box' or I' shaped beam.
12. The torque angle gauge of any of the preceding claims, wherein the first reference indicator is distinguishable from the second reference indicator.
13. The torque angle gauge of claim 12, wherein the first reference indicator is a different colour from second reference indicator.
14. The torque angle gauge of claim 12, wherein one of the projected reference indicators is constant and the other projected reference indicator is intermittent.
15. A method of measuring the amount of angular torque applied to a fastening comprising the steps: a) attaching a torque angle gauge with two radially oriented light sources between a tool and a fastening; b) using the angular gradations present on the gauge, set the angle between the first and second light sources so that the angular difference between the reference indicators projected by the first and second light sources is equal to the required torque angle setting; c) locate the positions of the where the first and second reference indicators are cast; d) apply the necessary torque angle to the fastening by working the tool in the required rotational direction until the second light source projects the second reference indicator on the point that was originally hit by the first reference indicator.
16. The method of claim 15, wherein the method further comprises the step of locking the positions of the first and second light source relative to one another so that the same torque angle can be repeatably applied to multiple fastenings.
17. The method of claim 15, wherein the torque angle gauge of any of claims 1 to 14 is used.
18. A single light source torque angle gauge comprises: a means for mounting the angle gauge between a tool and a fastening; a disc coaxially mounted on the mounting means, said disc having a plurality of angular gradations located thereon; a light source positioned to emit a focused light beam radially outwards from the centre of the disc, said light source being rotatably mounted relative to the disc; biasing means to direct the light source to rotate in one direction relative to the disc; and a restricting member, lockable at any point on the disc to stop the rotation of the light source and ensure that the light source always returns to the same angular orientation relative to the disc.
19. The single light source torque angle gauge of claim 17, wherein torque angle gauge further comprises a second, fixed restricting member to prevent the biasing means being overstretched by the manual movement of the light source by a user.
20. A torque angle gauge substantially as described, with reference to the drawings, herein.