GB2302200A - Drum with tuning arrangement - Google Patents

Abstract

The drum comprises a drum shell 11, a drum head 12 having a skin 17 and a head hoop 18 at its periphery, a counter-hoop 13, a resiliently deformable compression ring 14 located between the counter-hoop and the head hoop and a shell ring 15 attached to and surrounding the shell. The shell ring has a plurality of nylon cam blocks 28, each having an inclined undersurface, on its outer surface. The counter-hoop has a corresponding series of stainless steel plates 31 which are inclined and which engage the cam blocks. One of the plates has an integral rack (32, Fig 5) which engages a pinion (34) rotatably mounted on the drum shell. Rotation of the pinion moves the rack and thereby tightens the skin. Location of the cam blocks on the shell ring can be achieved with considerable accuracy, thus minimising the likelihood of uneven forces being applied to the head hoop. Any residual unevenness is accommodated by the compression ring.

Description

DRUM The present invention relates to drums, that is to say percussion instruments, such as snare drums, tomtoms, bass drums, tympanis, and the like. The invention is particularly concerned with the tuning of drum heads.

In conventional drums, the skin of the drum head is stretched over the open end of a cylindrical drum shell and is held in position by means of a counter-hoop which bears on the rim of the head. The skin is tensioned by means of tensioning bolts which act on the counter-hoop and engage tapped fittings fixed to the drum shell. When these bolts are tightened, the counter-hoop is urged against the rim, thus tensioning the skin.

In order to ensure that the skin is evenly tensioned and is therefore "tuned", it is necessary to adjust minutely each of the bolts, which are usually at least six or eight in number. This procedure is complicated by the fact that when one bolt is adjusted it has differing effects on the tension on the skin produced by the other bolts, making tuning a very time consuming and skilled operation.

Two related proposals which seek to address this disadvantage are described in British Patent Nos. 1488167 and 1558045. In the first of these references, the counter-hoop has a series of circumferentially located inclined slides which each engage a pair of rollers which are fixed to the shell. The rollers in each pair are offset to define an angle of inclination which corresponds to the inclination of the slides. Thus, as the counter-hoop is rotated in one sense, the slides and rollers engage, drawing the counter hoop down against the head rim and so tensioning the head. Rotation in the other sense has the opposite effect. The counter-hoop is rotated by means of a rack which is fixed to the counterhoop, and a pinion fixed to the shell; as the pinion is rotated, the rack is driven circumferentially.The arrangement shown in the second reference is very similar except that the rollers are replaced by inclined nylon blocks.

A disadvantage of these arrangements is that even tensioning is still difficult to achieve in practice, partly due to unevenness and imperfections in the heads and partly due to the difficulties in attaching the rollers or blocks accurately to the shell. Fine tuning screws are provided in the counter-hoop in an attempt to address this problem but these require similar adjustments to the tensioning bolts or conventional drums.

It is therefore an object of the present invention to provide a system which enables a drum skin to be tensioned and tuned in a single operation.

According to the present invention there is provided a drum comprising:- a drum shell; a drum head having a skin extending over an open end of the shell and a circumferential hoop lying outside the open end of the shell; a counter-hoop lying over the head hoop, the counter-hoop having a plurality of circumferentiallyspaced inwardly-facing cam followers; and means for rotating the counter hoop about the drum axis with respect to the drum shell; the drum also including a shell ring attached to and surrounding the shell in the vicinity of the open end and a compression ring located between the counter-hoop and the head hoop; the shell ring having a plurality of circumferentially-spaced, outwardly facing cam members which respectively engage the counter-hoop cam followers.

Thus, the counter-hoop bears on the head hoop through the compression ring and the cam followers on the counter-hoop engage beneath the cam members. As the counter-hoop is rotated the camming action causes the counter-hoop to be drawn down on to the head hoop and so the skin is tightened. The location of the cam members on the shell ring can be achieved with considerable accuracy, thus minimising the likelihood of uneven forces being applied to the head hoop by the counter-hoop. Any residual unevenness, which may be as a result of imperfections in the head can be accommodated by the compression ring.

Preferably the cam members are blocks, for example of nylon, which have an inclined underface. The inclination of each block therefore effectively constitutes part of a discrete helix which would extend around the drum. Preferably the cam followers are inclined plates or slides which each follow a corresponding helical path about the drum. The slides may be of a suitable metal such as stainless steel.

Preferably the means for rotating the counter-hoop comprises a rack and a pinion. Preferably the rack is fixed to and extends part of the way around the counterhoop, the rack being inclined at the same helical angle as the cam followers. Preferably, the pinion is rotatably mounted relative to the drum shell.

Preferably, the counter-hoop is of stainless steel which is preferably polished. The compression ring may be of any suitable deformable material and is preferably also resilient; a convenient material is NEOPRENE (T.M.).

Preferably, the shell ring extends beyond the edge of the shell in order to define the rim across which the skin is stretched.

There may be at least four cam members and four cam followers, and preferably six or more of each.

Preferably, the rack is formed integrally with one of the cam followers.

Preferably, a series of buffers are provided on the drum shell, in order to protect the surface of the shell.

The buffers are preferably arranged circumferentially about the shell near the top and bottom. They may each comprise a resilient insert in a metal housing. The insert is preferably of SANTOPRENE (T.M.) and the housing of polished stainless steel. The buffers are of particular benefit when different sized drums are stored one inside the other, a realistic possibility in accordance with the invention in view of the fact that the heads can be removed very simply.

The invention may be carried into practice in various ways and one embodiment will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a partial vertical section through one wall of a drum in accordance with the present invention; Figure 2 is a view similar to Figure 1 to a larger scale, with the cam members and followers omitted; Figure 3 is a partial plan view of the drum; Figure 4 is a partial vertical section through the top part of the drum; and Figure 5 is a partial vertical section of the top part of the drum additionally showing the rack and pinion.

Referring first to Figures 1 and 2, the drum comprises a drum shell 11, a drum head 12, a counter-hoop 13, a compression ring 14 and a shell hoop 15. The drum shell 11 is of standard laminated resin bonded hardwood construction. It is cylindrical and open ended. The shell hoop 15 is of polished stainless steel and is rigidly attached around the top of the shell 11. The shell hoop has a rim 16 which extends above the top of the open end of the shell 11.

The head 12 comprises a skin 17 and a flesh hoop or bead 18 at its periphery. The head 18 is located outside the shell hoop 15 so that the skin 17 stretches over the rim 16. The counter hoop is of polished stainless steel and comprises three vertical rings 21, 22, 23 of increasing diameter interconnected by two annular portions 24, 25. These effectively define an upper narrow channel 26 and a lower wide channel 27. The band 18 is thus located within the upper channel 26. The compression ring 14 also is located in the upper channel, between the counter hoop 13 and the head 18.

Referring now to Figures 1, 3 and 4, the shell hoop 15 has on its outer surface a series of nylon cam blocks 28. These each have an inclined undersurface 29. The counter-hoop 13 has a corresponding series of stainless steel plates 31 which are inclined in a way which corresponds to the inclination of the undersurface 24 the blocks 28.

As shown in Figure 5, one of the plates 31' has an integral rack 32 with downwardly facing teeth 33. The rack 32 therefore has the same inclination as the plate 31'. A pinion 34 is rotatably mounted on the drum shell 11 and engages the teeth 33 of the rack 32.

In use, when the drum components are assembled, the plates 31 are located beneath the blocks 28. The vertical ring 22 and horizontal portion 24 of the counter-hoop 15 engage the compression ring 14 which bears down on the bead 18. The skin 17 extends over the rim 16. As the pinion 34 is rotated, anticlockwise in Figure 5, the rack 32 is drawn to the left. The plates 31 slide beneath the blocks 28 and the inclined surfaces 29 cause the counter-hoop 13 to be forced downwards.

This in turn exerts a downward pressure on the bead 18 which stretches the skin 17 evenly over the rim 16. Any slight unevenness in the skin is compensated for by the compression ring 14.

Claims (14)

1. A drum comprising: a drum shell; a drum head having a skin extending over an open end of the shell and a circumferential head hoop lying outside the open end of the shell; a counter-hoop lying over the head hoop, the counter hoop having a plurality of circumferentially spaced inwardly facing cam followers; and means for rotating the counter-hoop about the drum axis with respect to the drum shell; the drum also including a shell ring attached to and surrounding the shell in the vicinity of the open end and a compression ring located between the counter-hoop and the head hoop; the shell ring having a plurality of circumferentially spaced, outwardly facing cam members which respectively engage the counter-hoop cam followers.

2. A drum as claimed in Claim 1, in which the cam members are blocks which each have an inclined undersurface.

3. A drum as claimed in Claim 1 or Claim 2, in which the cam followers are inclined plates, whose inclination corresponds to the inclination of the cam members.

4. A drum as claimed in any preceding Claim, in which the cam members are of nylon and the cam followers are of stainless steel.

5. A drum as claimed in any preceding Claim, in which the means for rotating the counter-hoop comprises a rack and a pinion.

6. A drum as claimed in Claim 5, in which the rack is fixed to and extends part of the way around the counterhoop and is inclined with the same inclination as the cam followers.

7. A drum as claimed in Claim 5 or Claim 6, in which the pinion is rotatably mounted relative to the drum shell.

8. A drum as claimed in any preceding Claim, in which the counter-hoop is of polished stainless steel.

9. A drum as claimed in any preceding Claim, in which the compression ring is of a deformable resilient material.

10. A drum as claimed in any preceding Claim, in which there are at least four cam members and at least four cam followers.

11. A drum as claimed in any preceding Claim, in which the rack is formed integrally with one of the cam followers.

12. A drum as claimed in any preceding Claim, further including a series of buffers provided on the drum shell, the buffers being arranged circumferentially about the shell near the top and the bottom.

13. A drum as claimed in Claim 12, in which each buffer comprises a resilient insert in a metal housing.

14. A drum, constructed and arranged substantially as herein specifically described with reference to and as shown in the accompanying drawings.