Adjustable pitch drum

An adjustable pitch drum consists of a drum shell having an open end, a drum head pitch changing mechanism, and a supporting structure mounting the pitch changing mechanism to the drum shell. The pitch changing mechanism consists of a threaded rod adjustably threaded to the supporting structure, a drum head clamping hoop mounted coaxially on the rod for rotation thereabout, and a drum head tensioning hoop non-rotatably mounted on the other end of the rod. Rotation of the drum head and its clamping hoop about the rod varies the tension of the drum head on the tensioning hoop, thereby changing the pitch of the drum. Movement of the threaded rod in the supporting structure changes the spacing of the drum head from the drum shell open end, thereby changing the resonance characteristics of the drum assembly.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to new and useful improvements in adjustable pitch 
drums and more particularly to a separate independently adjustable pitch 
drum head having a supporting means securing the same on a conventional 
drum shell. 
2. Brief Description of the Prior Art 
A conventional drum consists of a cylindrical drum shell having drum heads 
held in place by head hoops. Conventional drums are usually not tunable 
except in a very narrow range by adjustment of the head hoop. 
A RotoTom is a recently designated adjustable pitch drum manufactured by 
Remo, Inc. of North Hollywood, California. The RotoTom is in public use 
and on sale but is not described in any patent or published literature 
other than a limited amount of advertising literature available from the 
manufacturer. The RotoTom has a stand and a threaded shaft which extends 
upward and terminates in an end portion which abuts the head of the drum. 
The drum consists of a single head mounted on a supporting hoop and 
supported on a rigid multi-legged spider support. The spider is secured on 
a threaded tubular support which rides on the threaded shaft. Rotation of 
the supporting hoop by the drummer causes the threaded support to move 
upward and downward on the threaded shaft and vary the tensioning force 
against the drum head to tune the same. The RotoTom does not have the 
appearance of a conventional drum and has encountered some customer 
resistance. In addition, the RotoTom, while adjustable in pitch, does not 
have the tone effects provided by the shell of a conventional drum. 
SUMMARY OF THE INVENTION 
This invention comprises a new and improved drum assembly consisting of a 
RotoTom coupled to a conventional drum shell and supporting means for 
supporting the RotoTom on such shell. 
It is an object of this invention to provide a new and improved adjustable 
pitch drum. 
Another object of this invention is to provide an improved supporting 
structure for mounting an adjustable pitch independently adjustable drum 
head on a drum shell. 
A feature of this invention is the provision of an independently adjustable 
drum head, known as a RotoTom, coupled by an adjustable support to a drum 
shell. 
Another feature of this invention is an improved supporting spider and 
adjustable shaft arrangement for supporting an independently adjustable 
drum head on a drum shell. 
Other objects and features of this invention will become apparent from time 
to time throughout the specification and claims as hereinafter related.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the drawings, there is shown a combination of an adjustable pitch drum 
with a conventional drum shell. The combination results in the advantages 
of adjustable pitch and the tone afforded by a conventional drum shell, 
together with the appearance of a conventional drum. In FIG. 1 the 
combination is shown including a conventional drum shell 1 having a lower 
drum head 2 held in place by a conventional drum hoop 3. The upper end of 
the drum is open and does not have the conventional drum head stretched 
thereon. 
At the open end 4 of drum shell 1 there is supported an adjustable pitch 
drum structure, generally designated 5 of the type known as a RotoTom. 
The RotoTom 5 consists of a threaded rod 6 which carries a tensioning 
spider at its upper end comprising the central support 7 having a 
plurality of legs 8 and 9 which extend to and are integral with a 
tensioning hoop 10. The tensioning spider is held in a fixed position at 
the end of supporting rod 6. 
A second spider 11 is supported on rod 6 and consists of a central threaded 
hub 12 having a plurality of supporting arms 13 extending outward to and 
being integral with a first supporting hoop 14. A second supporting hoop 
15 is spaced from spider 11 and fits inside clamping hoop 16. Hoops 15 and 
16 secure the periphery of drum head 17 tightly. Hoop 16 has a lower 
flange 18 through which extend a plurality of bolts 19 which are 
threadedly mounted in bosses on supporting hoop 14 of spider 11. 
Hoop 14 may be rotated to turn support 12 on threaded shaft 6 to vary the 
position of spider 11 relative to the tensioning hoop 10. Tensioning hoop 
10 is maintained in a position abutting the drum head 17 and rotation of 
supporting hoop 14 moves the same on shaft 6 to adjust the tension of the 
drum head for tuning. This adjustment is operable to tune over a range of 
up to several octaves. The structure, so far described, is that of a 
commercially available RotoTom. 
In this apparatus there is provided a supporting spider 20 having a 
plurality of legs 21 secured in a fixed position to supporting plate 22. 
The legs 21 are rebent at their respective upper ends as indicated at 23 
to provide a supporting rim fitting over the open end 4 of drum shell 1 
and held in position by drum hoop 24. The supporting legs 21 are made 
rigid by bracing flanges 25 which are formed integrally therewith. In the 
embodiment illustrated in FIGS. 1 and 2, there are provided four of the 
supporting arms 21 spaced equally around the drum shell 1. 
Supporting plate 22 has a nut 26 secured on the lower surface thereof as by 
welding or brasing. Nut 26 provides a fixed threaded support for shaft 6 
of the RotoTom. On the upper side of the assembled support is provided a 
lock washer 27 and locking nut 28 having an operating level 29 terminating 
in a handle 30. 
When the apparatus is assembled, the support spider 20 is placed over the 
open end 4 of drum shell 5 and held in place by drum hoop 24. Next, the 
shaft or supporting rod 6 of the RotoTom has the locking screw 28 threaded 
thereon and lock washer placed in position. The shaft or supporting rod 6 
is then threaded into supporting nut 26 on the support spider 20. The 
RotoTom shaft or supporting rod 6 is threaded into to nut 26 to the 
desired position relative to drum shell 1 and handle 30 is used to rotate 
lever 29 to rotate nut 28 until it is compressed against lock washer 27 
and secures the shaft in a fixed position. 
When the drum is assembled in this manner it has the appearance of a 
conventional drum but provides the action and tone of a RotoTom. 
Supporting hoop 14 may be rotated to vary the pitch of drum head 17 and 
can provide tuning over a wide range. When lever 29 is moved to rotate nut 
28 and release shaft or supporting rod 6 for movement, rotation of 
supporting hoop 14 will cause shaft or rod 6 to be threaded into or out of 
supporting nut 26. This will cause the RotoTom to be moved upwardly or 
downwardly relative to the open end 4 of drum shell 1 and provide an 
additional variation in tone. The movement of the RotoTom relative to the 
open end of drum shell 1 provides for variation in resonant tone as well 
as the tuning which may be effected by rotation of the RotoTom on its 
supporting shaft or rod 6. When the RotoTom is positioned relative to 
supporting spider 20 at a point providing the desired resonant tone, lever 
29 is operated to rotate locking nut 28 to lock the shaft or rod 6 in a 
fixed position.