GB2159658A

GB2159658A - Improvements to drum heads

Info

Publication number: GB2159658A
Application number: GB08406779A
Authority: GB
Inventors: Robert Craig Hedditch
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-03-15
Filing date: 1984-03-15
Publication date: 1985-12-04
Also published as: GB2159658B; GB8406779D0

Abstract

In a drum-head 1 for a musical instrument, or a musical instrument including a drum head, the said drum head is formed from a polyurethane plastics material. Preferably the polyurethane plastics material is an elastomeric, urethane thermoplastic rubber. More preferably, the urethane thermoplastic rubber has a specific gravity in the range 1.11 to 1.25 inclusive, a tensile strength in the range 27.0-56.0 N.10<6>m<-2> inclusive, a flexural strength in the range 6.89-13.79 N.10<6>m<-2> inclusive, a compressive strength in the range 130.9-144.7 N.10<6>m<-2> inclusive, an "Izod" impact strength in the range 0.56 to 0.70 mKg inclusive and a water absorbtive property of not more than 1.00%/24hr. Most preferably the plastics material is that known in the marketplace as "Kaylan D75". <IMAGE>

Description

SPECIFICATION Improvements to drum heads The present invention is concerned with improvements to drum heads, such as are used on musical istruments of the drum-type or banjo-type.

Known drum-heads otherwise known as drum-tensioning heads, have previously been made of laminated wood or of metal, and are subject to changes in shape and physical parameters which affect the sound quality of the musical instrument to which they are attached. These changes usually accompany alterations in the ambient temperature or the humidity of the atmosphere surrounding the instrument.

The occurence of these changes presents a problem as the instrument must be tuned before use and subsequent alterations of the sound-quality require re-tuning of the instrument which is both time-consuming and inconvenient.

According to a first aspect of the present invention there is provided a drum-head for a musical instrument, formed from a polyurethane plastics material.

According to a second aspect of the present invention there is provided a musical instrument including a drum head formed from a polyurethane plastics material.

Conveniently, the polyurethane plastics material is an elastomeric, urethane thermoplastic rubber.

Preferably, the urethane thermoplastic rubber has -a specific gravity in the range 1.11 to 1.25 inclusive, a tensile strength in the range 27.0-56.0 N.106m-2 inclusive, a flexual strength in the range 6.89-13.79 N.106m-2 inclusive, a compressive strength in the range 130.9-144. 7 N.106m-2 inclusive, an ' 'Izod' impact strength in the range 0.56 to 0.70 mKg inclusive and a water absorbtive property of not more than 1.00%/24hr.

Rigid, elastomeric, urethane rubbers are among the most abrasive resistant of all plastics materials. Furthermore, they are resistant to chemical degradation by the atmosphere and by organic solvents. Moreover, the use of the non-conducting and heavilly damping urethane rubber, removes the problems associated with metal parts which may become electromagentically coupled with any sensitive "pick-up" device being used in association with the instrument.

It has been found that the polyurethane elastomer known in the marketplace as "Kaylan D75 Black" is of particular utility when employed in the present invention.

In a particular embodiment of the present invention the mounting lugs for mounting the drum head on the drum body may also be formed of a polyurethane elastomer.

In order that the present invention may be better understood it will be described in further detail with reference to the accompanying drawings wherein; Figure 1 shows a part of a drum and an exploded drum head according to the present invention, and, Figure 2 shows a cross-section through the drum head of Fig. 1 along the line X-X.

Turning now to Fig. 1 there is shown a drum head 1 comprising a substantially annular body of polyurethane elastomer and having a plurality of depentant, intergrally-formed lugs 2 disposed perimetrally about the annulus 1. Each lug is provided with a hole 3.

In the example given the substantially annular body was formed of the polyurethane elastomer known in the marketplace as "Kaylan D75 Black", by conventional moulding techniques.

A plurality of hook-like elements 4, equal in number to that of the lugs 2, are located in the holes 3. The purpose of these elements is to apply a downwardly acting force to the annular body 1. Each hook-like element 4 has a threaded shank 9 at its lower end. It should be understood that the particular method of tensioning the drum head is not limited to that of the present example, but will vary from one type of instrument to another, and therefore it is possible to envisage embodiments of the present invention which do not employ these hook-like members.

In use, a drum-skin 8 is placed over the end of a drum body 7. With certain musical instruments, for example with a 'conga' type drum, a metal or wooden ring is inserted within a fold of the skin to enable the drum head to obtain a purchase on the skin. Such a ring is not shown in the present example, however it should be understood that such a ring may be employed with the drum head of the present invention. The annular body 1 is placed over the drum-skin and the hook-like ends of the hook-like elements 4 are located in the holes 3 of the lugs 2. The threaded shank 9 of each hook-like element 4 is passed through a hole 10 provided in a mounting lug 5 mounted on the drum body 7 and a nut 6 is screwed onto the shank. The drum skin may now be tensioned in the conventional manner by a progressive tightening of the nuts 6.

It is a particularly advantageous feature of the present invention that both the drum head 1 and the mounting lugs 5 may be formed of the polyurethane elastomer without any reduction in sound quality.

Turning now to Fig. 2 there is shown a cross-section along the line shown in X-X in Fig. 1.

It can be seen from Fig. 2 that the hole 3 is countersunk at the aperture facing away from the drum body. This countersinking 11 facillitates the securement of alternative fixing means other than the hook-like element 4, to the drum head 1.

Although the invention has been described in terms of a drum head, it should be understood that the present invention also extends to drums employing a drum head of the type described above, to fixtures such as the hooklike elements and the mounting lugs mounted on the drum body, when these are made of a polyurethane elastomer.

Claims

1. A a drum-head for a musical instrument formed from a polyurethane plastics material.

2. A musical instrument including a drum head, wherein the said drum head is formed from a polyurethane plastics material.

3. The drum head of claim 1, wherein the polyurethane plastics material is an elastomeric, urethane thermoplastic rubber.

4. The drum head of claim 3, wherein the urethane thermoplastic rubber has a specific gravity in the range 1 .11 to 1.25 inclusive.

5. The drum head of claim 3, wherein the urethane thermoplastic rubber has a tensile strength in the range 27.0-56.0 N.106m-2 inclusive.

6. The drum head of claim 3, wherein the urethane thermoplastic rubber has a flexual strength in the range 6.89-13.79 N.106m-2 inclusive.

7. The drum head of claim 3, wherein the urethane thermoplastic rubber has a compressive strength in the range 130.9-144.7 N.1 06m - 2 inclusive.

8. The drum head of claim 3, wherein the urethane thermoplastic rubber has an "Izod" impact strength in the range 0.56 to 0.7 mKg inclusive.

9. The drum head of claim 3, wherein the urethane thermoplastic rubber has a water absorbtive property of not more than 1 /24hr.

10. The drum head of any of the preceding claims, wherein the polyurethane plastics material is that known in the marketplace as "Kaylan D75".

11. A drum head as claimed in any of the preceeding claims wherein mounting lugs for mounting the drum head on the drum body are formed of a polyurethane elastomer.