The invention relates to a device for controllably applying a torque to a turnable fixing. In particular, it relates to a torque wrench. More specifically, the invention relates to a device for controlling the torque applied to lugs or fixings securing a drum head to a drum frame. The invention also resides in a system for controllably tightening a drum head using the device.

Background of the invention

Drums are typically tuned using a hand-held key that is connected to lugs upon a drum via, for example, a 6mm-square socket, on the key - the key being turned by hand to control the tightness of the head upon the drum. Each of the lugs on a drum are tightened or loosened by hand, in turn, until the head is tuned to the correct pitch. The torque applied to the lugs via the key adjusts the tension of the head and directly affect s the pitch.

One known device for tuning drums is a“Tune-Bot” (www.tune-bot.com) that rests on the edge of a drum adjacent the head and indicates electronically the pitch of the drum corresponding to a point on the drum at which the head was struck. Tuning a drum using a“Tune-Bot” device involves placing said device at the edge of the drum and sequentially adjusting the head of the drum by manually turning the key upon each lug until striking the drum at points on the head adjacent each lug result in the same pitch being played. The level of torque applied to the lugs is repeatedly adjusted until a strike upon the drum indicates, via the electronic device, the desired pitch.

An alternative known drum tuning device resides in a mechanical device that measures the displacement of the head. Such a known device is a“Drum Dial” (www.drumdial .com). This device is placed adjacent each lug upon the head of the drum and each lug is adjusted until the displacement of the head is constant.

Known devices do not inhibit over-tightening of the lugs of a drum, which could lead to irreparable damage to the drum head or the drum components. Known devices are also slow to use because a musician setting up the drum will constantly have to adjust each lug until the desired pitch is achieved.

Moreover, tuning the drum using these known devices, or by ear, requires a degree of skill. Such configuration can only be achieved in quiet or controlled environments. It would not be possible, for example, for a drum head to be changed and tuned quickly at an event such as a concert where (i) the background noise would inhibit detection of the pitch and (ii) the speed at which the drum could be tuned by measuring the displacement would be a gross inconvenience. Summary of the invention

In general terms the invention resides in a device for applying a controlled torque to a fixing. The invention is demonstrated, merely by way of example, in the form of a drum adjustment device for adjusting or tuning the head on a drum. The device has a head for engaging with a fixing and a drive or handle for turning the head and fixing. Between the head and the handle is a torque mechanism that is adjustable to set a maximum torque applicable to a fixing via the head. The torque mechanism has a clutch and bias against the clutch. Adjusting the bias varies the maximum torque transferrable from the handle to the head. The bias mechanism has two or more bias units, which are arranged to extend parallel to the axis about which the handle turns. This arrangement can allow the bias mechanisms to be packaged alongside the drive. And, this arrangement can allow the bias mechanisms to be packaged within the handle between proximal and distal ends of the device. More particularly, the bias mechanisms are configured between the head at the distal end and the clutch, which resides at the proximal end. This can provide improved adjustment control and/or packaging of the device.

From one aspect, the invention resides in a drum adjustment device for adjusting or tuning the head on a drum, the device having: a head at a distal end of the device for engaging with a lug or fixing on the drum, said head defining a turn axis about which the head is arranged to turn a lug or fixing; a drive located towards a proximal end of the device, the drive configured to turn around a drive axis to turn the head; and a torque mechanism connecting the drive and the head, wherein said torque mechanism is adjustable to adjust the maximum torque applicable by the drive to the head, said torque mechanism having: a clutch; and a plurality of elongate bias units adjustable to adjust a force applied to the clutch, each bias unit defining a bias axis that defines a direction along which said force is applied to the clutch, wherein the bias axes are arranged to extend parallel to the drive axis.

The bias axes can be positioned parallel to drive axis, about which the drive is arranged to turn. This can improve packaging of the device because the length can be shorted because the bias axis is not necessarily in line with the drive axis. The drive axis can extend perpendicularly from the turn axis or be aligned with turn axis 20, or be changeable between these positions.

The torque mechanism can have two or more bias units or members. The bias members can be equally spaced about the drive axis. The equal spacing can be in a circumferential or radial pattern such that, for example, two bias members can be positioned opposite each other at 180-degree positions. If three bias units were used then the units can be displaced 120 degrees apart, at equal distances from the drive axis. The bias units can apply the force to the clutch in a direction towards the distal end. In this configuration the bias units are packaged between the proximal end operable by a user and the distal end that engages with a fixing. The direction of force applied to the clutch can be directed away from the fixing towards the clutch.

At least one bias unit can have a resilient member arranged around a threaded rod and a nut movably mounted upon the threaded rod is configured to compress the resilient member thus enabling adjustment of the force applied to the clutch. The nut can have a washer arranged between the nut and the resilient member. The nut can be a special nut having an aperture for each threaded rod or guide such that displacement of the nut moves the or each bias unit simultaneously.

An adjustment ring can be configured to adjust the force applied to the clutch. The adjustment ring can be connected via a gear to at least one bias unit. The adjustment ring, when rotated, can turn a nut to adjust the compression on a resilient member.

The resilient member can be a spring or a compressible member. The spring can have a helical spring component and/or a spring washer, such as a Belleville washer. The spring can be mounted around the threaded rod such that the rod passes therethrough.

The mechanism for compressing the resilient member has been described as a nut upon a threaded member, although additionally or alternatively, a ratchet type mechanism or similar screw- type adjustment means.

The bias units can have different configurations. The bias units can include springs and each bias unit can have a different spring configuration. At least three different springs can be provided in the bias units of the device. The at least three different springs can all have different compression forces. For example, a strong, medium and light spring can be provided.

The device can be provided with an even number of bias units. At least two of the bias units can be symmetrical. This is the simplest configuration of the device. Alternatively, the bias units can be asymmetrical. The forces applied to the clutch by each bias unit can be different. The forces applied by the bias units to the clutch can be asymmetrical.

Each bias unit can have a spring for applying a force against the clutch. The springs can be identical. At least one of the bias units can have two or more springs. At least one of the bias units can have two or more springs and said bias unit having two or more springs can have at least two different springs. Having an asymmetrical system in which bias units apply different forces can enable a greater range of torque to be applied. By having two or more different springs on one bias unit the sensitivity of the device can be increased. Additionally, or alternatively, configuring at least one of the bias units with a shorter spring that, at some torque settings, does not apply a force to the clutch the range and/or sensitivity can be increased further.The adjustment means can be located proximal the head of the device. The clutch can be located at the distal end of the device, said distal end being the operable end of the device. The bias units can be configured between the adjustment means and the clutch.

The clutch can have a head-side plate, connected to the head and a drive-side protrusion or plate, connected to the drive mechanism. The protrusion and/or plates of the clutch can have reciprocating features that disengage when the rotational force applied by the head-side plate to the drive-side protrusion or plate exceeds a threshold and the drive-side plate or protrusion is biased against the bias unit. Different forms or shapes of reciprocating or matching features can be envisaged. The clutch can have a slipper-type mechanism. The matching features of the clutch remain engaged when a rotational force is beneath a threshold. Plates of a clutch can be configured to be parallel and substantially planar, except for the matching features e.g. the protrusions and holes. When the rotational force exceeds a threshold the matching features of the clutch disengage.

The reciprocating features can have the same number of protrusions and recesses. For example, one plate of the clutch can have six recesses while the other has six protrusions. Said recesses and protrusions can be aligned. The reciprocating features can have a number of protrusions and recesses, and the number of recesses can be an integer multiple of the number of protrusions.

A plate having protrusions can be replaced by independent protrusions. Such protrusions can be positioned by a guide or body receiving such protrusions. The number of recesses for receiving protrusions can be two or more, but can be 6, 12, 24 or 36. The number of protrusions can be equal to, or less than the number of recesses and can be two or more, but can be 6, 12, 24 or 36. A greater number of recesses can provide a greater degree of haptic feedback.

The plates of the clutch can both be configured with recesses and the clutch can be provided with bearings between the plates that resides in the recesses until displaced when rotation of the drive with respect to the head exceeds a threshold level of torque.

A gauge can be provided to indicate the level of the torque threshold. The gauge can be located at the proximal end of the device. The gauge can be configured to indicate the maximum torque force applicable to the head via the drive. The gauge can be digital. The gauge reading can be based upon the degree of displacement of a bias unit towards the clutch. The gauge reading can be based upon the degree of displacement of a nut towards the clutch. The position of a nut can be read by a sensor, such as a potentiometer. The device can be configured to connect to hand held electronic device to record or indicate the threshold level of torque applicable by the device. A housing can at least partially enclose the drive and the cross-section of a central portion of the housing between the distal and proximal ends has two planar surfaces. The surfaces can extend parallel to each other. The housing can be configured with two, three, four, five or six surfaces. These surfaces accommodate a user’s hand for ergonomic purposes. The number of surfaces can be selected to complement the number of bias units to be packaged in the housing.

The invention also resides in a system for applying torque to a fixing, such as the torque applicable to the lug of a drum for tuning the head on a drum, the system having device according to any preceding claim. In light of the teaching of the present invention, the skilled person would appreciate that aspects of the invention were interchangeable and transferrable between the aspects described herein and can be combined to provide improved aspects of the invention. Further aspects of the invention will be appreciated from the following description.

Brief Description of the Figures

Figures la and lb show end elevation and plan views of the device respectively;

Figures 2a to 2f show perspective views and a cross-sectional view of the device, and variations thereof, shown in Figures la and lb, while Figures 2g to 2k show sectional and perspective views of the device having different spring configurations;

Figure 3 shows a system having the device of Figures 1 and 2;

Figure 4 shows perspective rendered views of the device having an adjustment ring and a display; and

Figure 5 shows a perspective view of an evaluation rig that evaluates the pull-force the device can apply to a drum tension rod.

Description of the Figures

Figures la and lb show a device 10 having a housing 12. A gripping portion 14 is provided on the housing to improve the ergonomic handling of the device during operation. A head 16 is provided at the distal end 18 of the device 10. The head 16 preferably has an interchangeable component in order that the device can engage with different types or shapes of lugs or fixings. The head 16 defines a turn axis 20 about which the head can turn a fixing.

A drive 22 is located at the proximal end 24 of the device 10. The distal end is configured to rotate about a drive axis 26. Rotation of the drive 22 about the drive axis 26 affects the turning of the head 16 about the turn axis 20.

In the Figures the drive axis is shown aligned with the turn axis. However, the turn axis 20 and drive axis 26 may be arranged substantially perpendicular such that the housing 12 extends from the turn axis and rotates therearound like a hand on a clock face. The inventor, however, proposes that the drive 22 turns around the drive axis 26 and that the drive axis 26 extends in line with the turn axis 20. The drive is configured to apply a rotational force to the head 16 that turns around the turn axis 20 until a threshold torque level is reached.

A torque mechanism 28 connects the drive 22 and the head 16. An adjustment ring 30 positioned at the distal end of the housing 12 can be rotated to adjust the threshold point, or maximum torque level, that limits the torque applicable through the torque mechanism to the head. When the level of torque required to turn the head reaches or exceeds the threshold or level then the torque mechanism stops the rotational force applied to the housing being transferred to the head.

An example of a torque mechanism 28 is shown in detail in Figures 2a to 2d. An alternative example is shown in Figures 2e and 2f. Like numerals refer to like features unless specifically mentioned. In each case, an interchangeable socket 32 can be located on the head 16 for engaging with a fixing. A drive shaft 34 extends from the head 16 to the drive 22(the housing of the device, not shown in all Figures). A drive shaft sleeve 36 can surround the drive shaft to enable uninhibited rotation of the head 16 and free rotation of the drive about the shaft.

The drive shaft 34 is connected to the drive at the distal end of the device 10 via an upper torque plate 38 or head-side plate. The upper torque plate 38 engages with a lower torque plate 40 or drive-side plate having protrusions 40a. In the alternative example shown in Figures 2e and 2f one or more pins 40a or the like perform the function of the protrusions on the torque plate 38. It is via this interface between the torque plates, via protrusions or upper torque plate and pins, that rotational force is transferred from the drive 22 to the head 16 and the torque threshold is determined. The use of protrusions 40a, which extend in part in to the head-side plate 38, enables the device to provide haptic or sensory feedback to a user, said feedback occurring because the protrusions 40a will be displaced when the torque being applied exceeds a threshold level.

To be clear, the upper torque plate 38 is directly connected to the drive and driven together with the drive shaft 34 and head 16 of the device 10. The lower torque plate 40, or each pin 40a, is directly connected to and moved by the housing 12 of the device when said housing is turned around the drive axis 26, or the turn axis should the drive extend perpendicularly from the turn axis.

The threshold or level is set by the torque mechanism 28, wherein a spring 42 is biased against the drive-side plate 40 or a pin 40a. The depth of the spring 42, and therefore the force applied to the drive-side plate, is adjustable by moving a nut 44 mounted on a lead screw towards the lower torque plate 40 thus compressing the spring 42 there-between. The spring 42 has the lead screw 46 passing there- through. The nut 44 is shaped to inhibit rotation within the housing and is, preferably, trapezoidal. In the examples of Figures 2a to 2d, a nut 44 is provided for each lead screw and is shaped to inhibit rotation within the housing when the lead screw is turned to displace the nut. In the example of Figures 2e and 2f a single nut 44 is provided, said nut having an aperture for each lead screw and a bridge 44a therebetween. Lead screw bearings 46a are provided at each end of the lead screw 46 to enable the lead screw to rotate about its axis. A lead screw gear 48 is connected to the distal end of the lead screw 46, and the rotation of said lead screw gear causes the lead screw 46 to rotate in the bearings 46a and move the nut 44, which is inhibited from turning, along the length of the lead screw, thus affecting the length of the spring 42. It is to be noted that the bridge 44a of the nut 44 on Figures 2e and 2f inhibit turning.

The lead screw gears 46 are held in place by a lead screw gear retainer 50. The lead screw gear 46 is connected to the adjuster 30 such that rotation of the adjuster causes rotation of the lead screw gears. Turning the gears turns the lead screws. The turning lead screws turn and move the position of the nut 44 mounted upon the lead screw and consequently adjust the length of the spring by compressing it, and the degree of bias against the lower torque plate 40.

The torque plates 38, 40 define a clutch 52. The clutch can be a slipper-type clutch, and can include a roller and cam mechanism, which locks the position of the drive and the head together with a specific force regulated by an adjustable bias unit. When a torque applied to the head exceeds a holding force of the clutch and the spring then the clutch will slip, and no torque will be applied to the head.

In Figures 2a to 2d, the plates of the clutch 52 are planar and extend parallel to one another. The clutch transfers a rotational force applied to the housing 12 through the lower torque plate 40 to the upper torque plate 38 that is connected to the drive shaft 34. The lower torque plate, or drive-side plate 40 is shown in Figures 2c and 2d having protrusions that are typically bumps or similar rounded features, such as a spherical cap. These caps are received within reciprocating holes or recesses in the head-side plate or upper torque plate 38. The spring 42 biases the lower torque plate caps into the recesses of the upper torque plate such that rotation of the housing causes a rotation of the head 16. When the rotational force required to turn the head exceeds a threshold torque level set by the drive, then the springs biasing the caps on the drive-side plate will be unable to maintain the caps within the holes and the caps will be displaced from the reciprocating holes on the upper torque plate. The spring will compress allowing the drive plate to rotate and, therefore, inhibit the housing on the drive 22 from turning the head 16.

Each displaced cap will quickly find a hole and snap or click back in to the next hold due to the spring bias upon the plate, thus providing haptic feedback. If the drive is rotated further, then the spring will compress again and the cycle of displacement and relocation of the caps within the holes will repeat. The clicking sound will repeat and audible and tactically indicate that the torque limit has been reached and that the head will no longer turn.

The clutch can additionally or alternatively have shaped protrusions and holes that allow the clutch to slip when a maximum tightening torque level has been reached but retains the clutch plates in a fixed relationship i.e. connected together when the device is rotated to loosen the lugs or fixings on the drum. In other words, the device is inhibited from over tightening a lug but the torque applied when undoing a fixing is unlimited.

The protrusions 40a of Figures 2e and 2f are an example of an alternative drive-side clutch. The pins 40a can be held in an aligned position with a body or guide. As shown in Figure 2e, the lead screws engage with the pins 40a such that the springs push against the outside edge of the pins 40a biasing the pins towards the upper torque plate 38. The pins are displaceable in the direction of the head 16 against the springs 42 such that they can be moved out of the holds on the upper torque plate 38. The shape of the head of the pin 40a can be asymmetrical such that the pin is more inclined to displace when the housing 22 is rotated in one direction compared to another. Additionally, or alternatively, the holes or recesses in the can be asymmetrically shaped such that the pin is more inclined to displace when the housing 22 is rotated in one direction compared to another.

In the examples shown, the torque mechanism 38 has a pair of lead screws 46, springs 42 and associated components. The components forming the torque mechanism in the embodiment shown can be considered as two bias units 54 working together. Each bias unit has a lead screw gear retainer 50, lead screw gear 48, lead screw bearings 46a and are arranged at either end of the lead screw 46 and a spring 42 that is biased against the clutch to enable the drive 22 to turn the head 16.

Each of the bias units 54 define a bias axis 56 along which the force of the spring is applied to the clutch. These bias axes extend parallel to the drive axis.

Two bias units 54 are shown by way of example and, in the opinion of the inventor, this provides an ergonomic configuration for improved turning. Having two or more bias units distributes the force applied to the clutch and enables the size of each unit to be reduced. The springs are, preferably, the same from a cost point of view. However, the inventor has realised that the performance of the device can be optimised by implementing different spring configurations, as described below.

Alternatively, three bias units could be packaged within the housing and the housing shape adapted to have a triangular cross-sectional profile. It is also anticipated that at least 4, 5 or 6 bias units could be packaged within the housing. The inventor considers the location of the adjustment ring 30 is ergonomically suited for location at the distal end of the device. It follows that the rotation of the ring 30, having a geared connection to the lead screw, can easily affect rotation of the screw such that it moves the nut and adjusts the length of the spring and the force applied to the clutch, thus adjusting the maximum torque applicable through the head that is connected to the clutch via the drive shaft. The inventors have also considered that a directional ratchet mechanism 55 can be provided at the distal end to enable a user to change and fix the direction that the device will turn the head 16.

The device, with the clutch located at the proximal end of the device, enables the drive shaft 34 to provide a stable core for the device 10 and with the bias units 54 packaged between the ring 30 and clutch 52, the overall length of the device 10 can be minimised. If the clutch were located between the bias units and the head then the clutch interface would require reinforcement to inhibit separation of the plates.

The device 10 having a plurality of bias units not only distributes the force applied to the clutch but in turn reduces the overall size of the device for a given spring type and torque range, which would be much larger if only one bias device was used.

Moreover, the length of the device can be shortened because, unlike traditional torque controlling or adjustment devices the components do not extend linearly along a spring axis from the head. In the device the clutch is located at the distal end and the bias mechanism is located between the clutch and the head.

In an alternative configuration, the ring 30 can be arranged at the distal end.

It is also possible within the scope of the invention to have the turn axis and drive axis arranged perpendicular to one another. In such a scenario, a torque mechanism 28 would still be provided within the housing 12 and a clutch 52 would control the torque applied between the drive 22 and the head 16. In this configuration the drive-side plate 40 that is biased by the springs 42 would be connected to a head-side plate 38 connected to the head - however, the form of the clutch would change and the head-side plate would be in the form of a drum having a central axis aligned with the drive axis 20 and a cam or similar recesses on its arcuate surface, while the drive-side plate would engage with the cam on the head-side plate to cause the head to turn about the turn axis 20.

A gauge 58 can be provided on the proximal end of the housing to indicate the level or threshold at which the drive will stop turning the head. Said level or threshold can be a newton-meter value and/or a scaled equivalent. The gauge can be calibrated to accurately indicate the level of torque applicable through the head. The gauge can be mechanical or digital, as shown in Figure 4. Gauge measurements can be derived from the position of the nuts 44 in relation to the shaft 34. By way of example, Figure 2f indicates how a bridge 44a, which functions as an extension or feature of a nut 44, can be used to engage with a sensor, such as a potentiometer strip 60. The strip can determine the position, which can be input to a processor to calculate or look-up the torque threshold corresponding to the position at which the nut 44 contacts the strip 60.

The device has generally been described and shown as having two bias units 54, each with a spring 42, lead screw 46 and nut 44 adjustably configured to vary the force applied to the clutch 52, typically via a protrusion 40a. While 3 or more bias units can be provided to define the range and sensitivity of the device the inventor has been able to configure and adjust the performance of the device by implementing different spring configurations.

Figure 2g to 2k show sectional and perspective views of the device having different spring configurations. For reference, Figure 2g has two identical symmetrical springs 42 and their free length extends from the nut 44 to the clutch. The deflection vs load graph of these springs is substantially identical except for tolerance variations. The performance of the device in Figure 2g can be modified by making the bias units asymmetrical and changing at least one of the wire diameter and number of coils of one of the springs - for practical purposes the free length is not changed and the outer diameter is not changed to minimise the impact of the other components of the device 10 or bias unit 54. Figure 2h illustrates an alternative asymmetric configuration in which the free length of one of the springs is shorter than the other such that in the lowest torque setting the short spring cannot impart a force on the clutch 52.

Figure 2i illustrates an asymmetric spring configuration in which the left hand bias unit 54, as viewed, has a short free length such that in the lowest torque setting the short spring cannot impart a force on the clutch 52, while the right hand bias unit, as viewed, has two different springs whose total free length when arranged together extends from the nut 44 to the clutch 52. The smaller of the two springs shown on the right hand unit is lighter i.e. has lower compression resilience and can be selected to adjust the sensitivity of the device at the lower end of the range. Figures 2j and 2k are, respectively, perspective and sectional views of Figure 2i showing the bias unit having two springs applying contacting the protrusion 40a that forms part of the clutch 52.

A selection of springs were used in the evaluation of the pull-force applicable to a drum nut, some of which are listed in Table 1. The spring material was stainless steel and the range of outer diameters ranged between about 6mm to about 7.5mm, while the wire diameters ranged from about 0.5mm to about 1 mm. Their free lengths were up to about 45mm. Table 1

6.35mm Compression Springs - O.Smm Stainless Steel R4.02 (#2507) » Required Length (mm); 45

6.35mm Compression Springs - 0.63mm Stainless Steel R1.33 (#2506) · Required Length ( mm); 45

7.3mm Compression Springs - 1.0mm Stainless Steel R11.71IM/mm/cm j#D29080j■ Required Length ( mm); 45 7.1mm Compression Springs - 0.8mm Stainless Steel R4.8!M/mm/cm ( #029070) · Required Length ( mm) ; 45 6.8mm Compression Springs - 0.5mm Stainless Steel R0.73N/mm/cm (#D29030b)■ Required Length ( mm) : 45 6.35mm Compression Springs - 0.63mm Stainless Steel R1.33 (#2506) · Required Length (mm) ; 45

6.35mm Compression Springs - 0.8mm Stainless Steel R4.02 (#2507) · Required Length (mm) ; 45

6.35mm Compression Springs - 0.63mm Stainless Steel R1.33 · Required Length ( mm) : 45

6.35mm Compression Springs - O.Smm Stainless Steel R4.02 · Required Length ( mm); 45

It is to be noted that the springs have been described in their configurations with respect to their free length but one or more springs can be installed in the device under tension such that a minimum level of torque can be applied to a fixing in the lowest setting i.e. when the nut 44 is furthermost from the clutch 52.

Independently of the values of the springs, the different spring configurations in Figures 2g, 2h and 2i were tested across a range of settings in the device shown. The configuration of Figure 2i was found to provide optimal settings because the bias member having two springs, whose free length was maximum in the minimum torque setting (i.e. the nut 44 furthest from the torque plate52), was able to finely adjust the torque because of the use of the smaller and lighter spring, as shown. As the torque setting increases and the nut 44 moves towards the clutch 52 then the larger heavier spring begins to apply a load against the clutch. When the nut is moved closer still to the clutch then all three springs impose a force upon the clutch such that a higher torque setting can be applied by the device. A higher torque setting translates to a higher pull force imposed on a drum skin through a lug.

Figure 3 shows a system in which the device 10 operates for tuning a drum. A device 10 is connectable to a hand-held computer device 200, such as a phone or tablet and/or a remote server, such as a computer 300. Preferably, the communications there-between are wireless, using a technology such as Bluetooth™.

The device 10 has the capability to connect to the internet or a hand-held device 200 in the vicinity via Bluetooth and/or other wireless means. Settings for the device that correspond to notes for generic or specific drum heads can be accessed, uploaded or shared. The device can also be configured with recording and/or playback components that enable notes and or sounds played adjacent the device to be communicated to a remote user or server. In this way, the device enables instruments to be tuned to the same specification across different locations i.e. groups working together across the globe. Accurate communication of a setting that gives a specific sound can be achieved because the device setting is shared and can be duplicated elsewhere. The device 10 is adapted to adjust the lugs on a drum and operate independently of the phone 200 and server 300. Settings for the device, or readings taken therefrom, may optionally be stored upon the phone and/or the server.

The process of tuning a drum involves tightening around the drum head by adjusting tension rod screws or lugs to accurately apply a predetermined tension. The process assumes that a clean and well-maintained drum is being tuned.

The required torque applied to the lugs of a drum can depend on (i) the diameter of the drum, (ii) the type of drumhead being used, (iii) the grade of the drumhead (e.g. single/double ply) and (iv) the tone or style preferred by the drummer.

The level of torque to be applied to a lug of a drum is known. This can either be given by an SI scale value i.e. N/m, or a proprietary value e.g. on a scale of 1 to 100. The level to be applied can be provided on the drum head in, for example, handwritten form. A single level or torque value can apply to the whole drum head such that each lug is tightened to the same level. The torque applied correlates to a pull-force applied by the drum tension rod.

The level is set by turning the adjuster 30 on the device 10 until the required level is shown on the gauge 58. This can be indicated by a number. The number is unique that that drum and the pitch to be achieved after tightening the lugs to the pre-set level.

Assuming that the lugs are all loose and need to be tightened then the drive 22 is rotated upon a lug until the clutch 52 slips thus indicating that the pre-set level of torque has been applied to said lug. A user will hear and feel movement of the clutch plates against one another. This is repeated until all lugs are tightened.

To change the level, the adjuster 30 is rotated.

The number of positions, or angle of ratio between the torque plates, can be set according to the level of sensitivity required by the device. In the examples, either six or eight indents are provided in the upper-torque plate 38. The lower-torque plate 40 in Figure 2d is shown having the same number of protrusions of the holes on the matching clutch plate. The number of protrusions can be adjusted and, by way of example, the example in Figure 2e has just two protrusions located at the end of each spring.

When the device is first used on a drum that has been set up, but the levels of torque applied to each lug is unknown, then levels can be determined and recorded. In this way, the head can be transferred to a different drum and configured quickly using the device, as per the basic tuning described above. To establish the level of torque applied to a lug, the steps below can be followed: a. Set the device to a low number, and this will mean that the setting is lower than the level of torque applied to the lugs.

b. Check that the lugs does not move when the device is turned.

c. Increase via the adjuster the level on the device by one division or unit of measure, or the smallest integral increment and attempt to turn the lugs again. Repeat this step until all the lugs move.

d. Undo the lugs by half a turn by turning the device in reverse.

e. Adjust the device level down by one division and re-tension the screw by turning the device rapidly.

f. The level of the device corresponds to the desired tuning preference of the drum head for this drum.

g. Then retune the drum as described above. Write on the drumhead the level indicated on the device.

This process can be repeated for different grades of drumhead on the same drum. If a previously tuned head is removed and then returned to the drum then setting the device to the recorded level written on the head and tightening the lugs to this level will quickly and accurately tune that head to the preferred setting.

The device can be used to create a library of different grades of heads to suit different styles of music that can be quickly and confidently changed. Standard settings can be suggested. Because of the huge array of different drumhead and musical styles, these suggested settings are only an indicator of the number range you might expect for a particular drumhead at a particular diameter.

In the development of the device the inventor created an evaluation rig 100, as shown in Figure 5. The rig has a chassis 102 having a drum tension rod 104 configured at one end and a pull plate 106 mounted on a skid 108. At the opposite end of the chassis 102 an anchor 110 is provided and a crane scale 112 is mounted on the anchor and secured to the pull plate such that the pull-force applied to the scale 112 by turning the tension rod 104 could be measured.

While the device is configured to apply a predetermined limited torque level to a fixing the performance of the device 10 was assessed based on the pull-force that it could apply to a drum tension rod. Such tension rods are available in a limited number of variants, one of the most common being a“12-24”, which comes from Unified and American Screw Threads for Bolts, Nuts, and Machine Screws standards published by ANSI Bl .1-1974. This“12-24” reference is given merely by way of example and in light of the teaching herein a skilled person would be able to correlate, or establish a relationship, between the device torque setting and the pull-force achievable through a drum tension rod.

Although the device can apply a torque to any fixing the application to drum tension rod concerns the pull-force in the practical application of tuning a drum. When tuning a drum the range of pull forces required is between a minimum of ‘finger-tight’ (about 5kg of pull-force) that can be achieved without using a tool and manually turning a fixing to secure a nut by hand and a maximum ‘destructive force’ (typically 300kg or above) that causes damage to the drum.

By using this rig the inventor was able to select a spring configuration that provided a pull force from approximately 5kg to 275kg. The maximum pull-force achievable by the device was in excess of 350kg and, therefore, springs were selected to limit the maximum torque applicable to a drum tension rod.

As described above, the device is configured with settings that, for example, range between 1 and 99 units. This range could be set to be between 1 and 199 or even 1 and 999. Additionally, or alternatively the range can be customisable.

During the evaluation of the device on the test rig the inventor was able to select a spring configuration that enabled a change of 1 unit to correspond to a quarter-turn of the tension rod, which results in a note of a drum from a C to a C#. A spring configuration that achieved a wide range of settings is shown, by way of example, in Figure 2i.

During evaluation of the different spring configurations, the lowest pull-force that the device could adjust with a symmetrical system, as shown in Figure 2g, was 2lkg. In contrast, the spring configuration of Figure 2i was able to achieve adjustment down to a pull-force of 5kg.

The device can be configured to emit a warning sound when the device applies or exceeds a predetermined level of torque.

In light of the teaching herein it can be appreciated that both the range and sensitivity of the device can be tuned to particular applications such as the tuning of a drum, and that setting the performance is achievable by adjusting at least one of the clutch 52, pitch of the lead screw 42 and corresponding nut 44 and spring 42. Modifying the spring configuration provides a simple and low- cost way of defining the performance range and sensitivity of the device.

Overall, the device 10 functions to apply a controlled level of torque to a fixing via the head 16 of the device. The adjustment of the level of torque is achieved through the adjustment ring 30. The rotation of the ring in turn adjusts the force applied by a bias unit 54 to a clutch 52 located in a drive 22. The level of force applied by the bias unit 54 to the clutch 52 determines the torque level at which the drive 22 stops rotating the head 16. This allows the device to adjust the tension rods on the drum to move in a unilateral manner, vertically up and down around the bearing edge thus facilitating the drum head to float up and down in equal amounts around the head producing an even tone.

The adjustment of the torque is affected by the rotation of the ring which in turn rotates an internal lead screw of the bias unit to cause a nut located on the lead screw to move along the length of a bias axis 56 defined by the lead screw, thus adjusting the length of one or plurality of springs 42 positioned between the nut and the clutch.

The drive-side plate 40 and head-side plate 38 of the clutch turn together while the bias unit 54 applies a sufficient force to the drive-side plate. When the torque applied to the drive 22 is sufficient to displace the drive-side plate with respect to the head-side plate, the spring 42 will compress such that the clutch disconnects thus inhibiting the drive from rotating the head.

The provision of caps and holes upon the clutch create a clicking sound when the torque threshold is reached. A number of caps and holes are provided in the clutch such that the springs 42 will repeatedly compress and the caps will repeatedly re-engage with the holes within the clutch to provide a clicking sound.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word "comprising" and "comprises", and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. In the present specification,“comprises” means“includes or consists of’ and“comprising” means“including or consisting of’. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The present invention has been described above purely by way of example, and modifications can be made within the spirit and scope of the invention, which extends to equivalents of the features described and combinations of one or more features described herein. The invention also consists in any individual features described or implicit herein.