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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a strainer for use with a drum, in
particular to an adjustable strainer for use with a snare drum.
2. Description of the Related Art
Snare drums typically include a plurality of wires, or snares, which
contact a bottom drumhead of the snare drum so that the snares are
vibrated by the vibration of the bottom drumhead when the snare drum is
played. A strainer is typically used to tension the snares in order to
change the tone produced by the drum by changing the position of the
snares so that they are either in contact or not in contact with the
drumhead.
U.S. Pat. Nos. 5,557,053 and 6,093,877 to Nickel are examples of
conventional strainers for snares of a snare drum. These strainers use a
lever directly connected to a piston, wherein the lever pivots about an
axis generally perpendicular to the piston, so that when the lever is
pivoted from one position to another, the piston drops and the tension in
the snares is released so that the snares are no longer in contact with
the drumhead. The pivoting lever of strainers such as these can only be
operated so that the snares are either in contact with the drumhead
(snares-on mode), or not in contact with the drumhead (snares-off mode),
and are not adjustable to different tensions in between. Further, the
strainer tends to be tensioned or released quickly, so that the snares
make an unwanted "throw-off" noise against the drumhead, which is very
undesirable, particularly for orchestral musicians. Also, the housings of
Nickel's strainers are made from plastic, and have been known to break
after only a few months of repeated use in a percussion environment.
U.S. Pat. No. 4,787,286 to Okumura, U.S. Pat. No. 5,559,296 to Yamashita,
and U.S. Pat. No. 6,008,445 to Chen also disclose strainers for snare
drums wherein a lever pivots about an axis generally perpendicular to a
piston, similar to Nickel. Further, none of these disclose a continuously
adjustable strainer that prevents the unwanted throw-off noise described
above.
U.S. Pat. No. 5,684,257 to Yanagisawa discloses a strainer having a lever
that pivots about an axis generally perpendicular to a slider assembly and
that can be adjusted to various discrete positions between the snares-on
and the snares-off modes. However, this strainer does not teach a strainer
that is continuously adjustable. Further, this strainer can still create
the undesirable throw-off noise described above, particularly if it is
adjusted quickly.
What is needed is a strainer that avoids the problems described above.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a snare drum strainer mountable
to a shell of a drum is provided. The inventive strainer includes a piston
and an actuator. The piston has an axis and a surface curved about an axis
generally parallel to the piston axis, wherein the piston is operatively
connectable to snares. The actuator and the curved surface rotate one with
respect to the other about an axis generally parallel to the piston axis
to cammingly engage one another to reciprocate the piston to tension and
untension the snares.
Also in accordance with the present invention, a novel snare drum strainer
mountable to a shell of a drum is provided having a piston and an
actuator. The piston has a generally cylindrical surface with at least one
generally helical groove, and the piston is operatively connectable to
snares. The actuator includes a follower insertable into the generally
helical groove, wherein the follower and the generally cylindrical surface
rotate one with respect to the other to reciprocate the piston to tension
and untension the snares.
Also in accordance with the present invention, a novel and improved snare
drum is provided. The novel snare drum includes snares, a shell, at least
one drumhead, and a strainer mountable to the shell, the strainer having a
piston and an actuator, wherein the piston has a generally cylindrical
surface with at least one generally helical groove and is operatively
connected to snares, and the actuator includes a follower insertable into
the generally helical groove, wherein the follower and the generally
cylindrical surface rotate one with respect to the other to reciprocate
the piston to tension and untension the snares.
The rotational camming engagement of the strainer, for example between the
follower and the helical groove, allows for continuous control of the
tension of the snares over at least a portion of the motion of the
strainer, so that different sounds can be selected between the snares-on
mode and the snares-off mode. Also, the rotational camming engagement of
the present invention prevents the unwanted throw-off noise described
above because the camming engagement of the actuator and piston is smooth,
and does not jerk the snares into, or out of, the snares-on mode.
These and other objects, features and advantages are evident from the
following description of an embodiment of the present invention, with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is perspective view of a snare drum shown with snares in a snares-on
mode.
FIG. 2 is a perspective view of the snare drum shown with the snares in a
snares-off mode.
FIG. 3A is a perspective view of the strainer in a snares-on position.
FIG. 3B is a partially cut away perspective view of the strainer in the
snares-on position.
FIG. 4A is a perspective view of the strainer between the snares-on
position and a snares-off position.
FIG. 4B is a partially cut away perspective view of the strainer between
the snares-on position and the snares-off position.
FIG. 5A is a perspective view of the strainer in the snares-off position.
FIG. 5B is a partially cut away perspective view of the strainer in the
snares-off position.
FIG. 6 is an exploded perspective view of the strainer of the present
invention.
FIG. 7A is a plan view of a piston of the strainer taken along line 7A--7A
in FIG. 7B.
FIG. 7B is a plan view of the piston taken along the line 7B--7B in FIG.
7A.
FIG. 7C is a plan view of the piston take along the line 7C--7C in FIG. 7A.
FIG. 8 is a projection of a generally cylindrical wall onto a plane showing
a helical groove detail of generally helical grooves of the piston.
DETAILED DESCRIPTION OF THE INVENTION
A strainer 10, sometimes called a "throw-off" mechanism, for use on a snare
drum 2 is shown in FIGS. 1 and 2. Snare drum 2 includes a shell 3 having
an upper end 4 and a lower end 5, with an upper drumhead (not shown)
mounted on upper end 4 and a lower drumhead 7 mounted on lower end 5. A
plurality of snares 8 are mounted to snare drum 2 so that they are
proximate and generally parallel to lower drumhead 7.
Snares 8 are movable between a tensioned, or snares-on mode, as shown in
FIG. 1, and an untensioned, or snares-off mode, as in FIG. 2. Snares 8 are
tensioned and untensioned by strainer 10 of the present invention. The
novel strainer 10 includes a piston 14 mountable to shell 3 of drum 2 so
that piston 14 can reciprocate, and an actuator 18 cammingly engageable
with piston 14. Piston 14 has an axis of reciprocation 20 and a surface 22
curved around an axis 21 that is generally parallel to axis of
reciprocation 20. Snares 8 are operatively connectable to piston 14, such
as by snare clamp 16 shown in FIG. 1. In one embodiment, piston 14 is
retained within a housing 12 connected to shell 3 so that piston 14 is
reciprocatably mounted to shell 3, see FIGS. 3A-5A Either actuator 18 or
curved surface 22 is rotatable so that one rotates with respect to the
other about an axis 23 generally parallel to axis of reciprocation 20 to
cammingly engage each other to reciprocate piston 14 to tension and
untension snares 8.
In one embodiment, curved surface 22 has at least one groove 24a extending
both laterally around piston 14 and axially along piston 14, and actuator
18 includes a follower 26a insertable into groove 24a. In one embodiment,
groove 24a extends laterally about piston 14 between about 90.degree. and
about 360.degree., preferably between about 120.degree. and about
270.degree., still more preferably about 180.degree.. As groove 24a
extends laterally about curved surface 22, it also extends axially along
curved surface 22 for an axial length L (shown in FIG. 7A). The axial
length L is selected to provide sufficient tension in snares 8 in their
snares-on mode and to provide adequate release of snares 8 in the
snares-off mode.
In one embodiment, groove 24a is generally spiral shaped extending along
curved surface 22 and curving around axis of curvature 21, wherein groove
24a curves generally along piston surface 22 in both a lateral and an
axial direction. Generally spiral groove 24a guides follower 26a so that
it follows a generally spiral path with respect to piston 14, wherein
piston 14 moves in the direction of axis of reciprocation 20 as actuator
18 rotates with respect to piston 14. In one embodiment, generally spiral
groove 24a extends around piston 14 for between about 1/4 and about 1
turn, preferably between about 1/3 and about 2/3 of a turn, and still more
preferably about 1/2 of a turn around piston 14.
In another embodiment, curved surface 22 of piston 14 is generally
cylindrical in shape, and there is at least one generally helical groove
24a in generally cylindrical surface 22. Actuator 18 includes a follower
26a insertable into generally helical groove 24a, wherein follower 26a and
generally cylindrical surface 22 rotate one with respect to the other to
reciprocate piston 14 to tension and untention snares 8.
The rotational camming engagement between piston 14 and actuator 18 moves
piston 14 from a first, or snares-on position, shown in FIG. 1, to a
second, or snares-off position, shown in FIG. 2. In a preferred
embodiment, shown in FIGS. 1 and 2, piston 14 has a generally vertical
orientation with respect to drum shell 3.
Drum
Snare drum 2 includes snares 8, at least one drumhead 7, a shell 3, and
strainer 10 mountable to shell 3. In one embodiment, shell 3 is generally
cylindrical in shape; however snare drum 2 can be of other shapes without
varying from the scope of the present invention.
In one embodiment, an upper drumhead (not shown) is mounted to shell 3 at
an upper end 4 and a lower drumhead 7 is mounted to shell 3 at a lower end
7. The drumheads can be mounted to shell 3 by any means known in the art,
for example rims 28 and 29 which are secured to shell 3.
Preferably, snares 8 are mounted to snare drum 2 so that snares 8 are
proximate and generally parallel to lower drumhead 7. Snares 8 can be
mounted to shell 3 directly, or snares 8 can be mounted to rim 28 or 29.
In one embodiment, snares 8 are mounted to lower rim 29 so that snares 8
are in contact with lower drumhead 7 when snares 8 are in the snares-on
mode, as shown in FIG. 1. In a preferred embodiment, snares 8 are mounted
to snare drum 2 by a snare anchor 30 mounted to lower rim 29 at one end of
snares 8, while the other end of snares 8 is mounted to a reciprocating
snare anchor 32 which is operatively connected to piston 14 via a strap 34
and snare clamp 16. As piston 14 moves from the snares-on position to the
snares-off position, snares 8 are moved from their tensioned or snares-on
mode to their untensioned or snares-off mode.
Housing
Continuing with FIG. 1, piston 14 is mounted to shell 3 by housing 12 of
strainer 10 connected to shell 3 so that a player of snare drum 2 can
easily change snares 8 from the snares-on mode to the snares-off mode
simply by changing strainer 10 from its first position to its second
position. In one embodiment, housing 12 is mounted to shell 3 via mounting
screws (not shown) which are inserted through mounting holes in shell 3
(not shown). Piston 14 can also be mounted to shell 3 by one or more
brackets or a frame.
Turning to FIG. 6, housing 12 includes a bore 36 extending through housing
12 for receiving piston 14. Preferably, bore 36 has a cross-sectional
shape that complements the cross-sectional shape of piston 14 so that
piston 14 will easily slide along housing bore 36. For example, for the
generally cylindrical piston 14 shown in FIG. 6, bore 36 is also generally
cylindrical in shape, wherein there is a small allowance between the bore
36 and piston 14. In one embodiment, housing 12 also includes a recess 38
for receiving actuator 18 so that actuator 18 can engage with piston 14,
as described below. Housing 12 can also include a guiding follower 27
which is inserted into a guiding groove 40 in piston 14, described below.
In one embodiment, shown in FIG. 6, guiding follower 27 comprises a set
screw 78 having a shank 80, wherein set screw 78 is threadingly engageable
with a hole (not shown) in housing 12. Guiding follower 27 can also
include a bearing 82 coupled with shank 80. In a preferred embodiment,
bearing 82 is a roller bearing mountable on shank 80 of set screw 78,
wherein roller bearing 82 is insertable into guiding groove 40 of piston
14.
Piston
Turning to FIGS. 3A-5A, piston 14 is mounted to shell 3, such as by
inserting piston 14 through bore 36 in housing 12, so that piston 14 can
move between its snares-on position and its snares-off position. Piston 14
includes an axis of reciprocation 20, shown in FIG. 7A, and a piston
surface 22 curved around an axis of curvature 21 generally parallel to
axis of reciprocation 20. In one embodiment, axis of curvature 21 and axis
of reciprocation 20 are one and the same, as shown in FIG. 7A.
Piston surface 22 cammingly engages with actuator 18, as described below,
to reciprocate piston 14 from its snares-on position to its snares-off
position to tension and untension snares 8. In a preferred embodiment,
shown in FIG. 6, there is at least one generally helical groove 24a in
piston surface 22. In one embodiment, piston 14 also includes a guiding
groove 40 (see FIG. 7A) for receiving a guiding follower 27 (FIG. 6) for
guiding piston 14 as it moves from its snares-on position to its
snares-off position and for preventing piston 14 from rotating relative to
housing 12.
In one embodiment, curved piston surface 22 is generally cylindrical in
shape so that curved piston surface 22 comprises at least a portion of a
generally cylindrical wall. In a preferred embodiment, piston surface 22
is shaped like a generally cylindrical wall around a substantial portion
of the circumference of a cylinder. However, piston surface 22 does not
have to be continuous around the circumference of piston 14, nor must
piston surface 22 have a generally circular cross section, as shown in
FIG. 6. In one embodiment, piston 14 is generally cylindrical in shape
having a length of between about 2 inches and about 21/4 inches,
preferable about 21/8 inches and a diameter of between about 1/2 inches
and about 7/8 inches, preferably about 11/16 inches.
Helical groove 24a extends around piston surface 22 and receives a follower
26a for cammingly engaging with actuator 18, as described below. In one
embodiment, shown in FIGS. 7A, 7B and 8, there are two helical grooves
24a, b spaced laterally from each other on piston surface 22 so that one
helical groove 24a is spaced around piston surface 22 from the other
helical groove 24b by a predetermined number of degrees. In a preferred
embodiment, the first helical groove 24a starts at a generally opposite
side of, or about 180.degree. around piston 14 as the second helical
groove 24b and extends around about 180.degree. of the circumference of
piston surface 22.
Continuing with FIGS. 7A and 7B, each helical groove 24a, b has a width W,
a depth D, and an axial length L. In one embodiment, each helical groove
24a, b has a length L in the axial direction of between about 1/4 inches
and about 1/2 inches preferably about 3/8 inches for a helical groove 24a,
b that extends around between about 90.degree. and about 360.degree.,
preferably between about 120.degree. and about 240.degree., and still more
preferably about 180.degree. of piston surface 22, a width W of between
about 3/8 inches and about 3/4 inches, preferably about 5/16 inches and a
depth D of between about 1/16 inches and about 1/4 inches, preferably
about 1/8 inches.
Each helical groove 24a, b receives and cammingly engages with a follower
26a, b to move piston 14 from its snares-on position to its snares-off
position. Followers 26a, b slide or roll along helical grooves 24a, b and
engage groove walls 42 and 44 in order to bias piston 14 in one direction
or the other. For example, in one embodiment, shown in FIGS. 3B through
5B, when actuator 18, described below, is moved from its snares-on
position to its snares-off position, follower 26a slides along helical
groove 24a and follower 26b slides along helical groove 24b in a
counterclockwise direction and cammingly engages with top groove wall 42,
allowing gravity to bias piston 14 generally downwardly from its snares-on
position to its snares-off position. If a player of snare drum 2 wishes to
return snares 8 to the snares-on mode, actuator 18 is moved from its
snares-off position to its snares-on position so that followers 26a, b
slide or roll along helical grooves 24a, b in a clockwise direction so
that followers 26a, b cammingly engage with a top groove wall 42 to bias
piston 14 generally upwardly from its snares-off position to its snares-on
position. In another embodiment (not shown), actuator 18 remains generally
stationary and piston 14 is rotated so that helical grooves 24a, b are
guided by followers 26a, b.
In one embodiment, best seen in the preferred helical detail of FIG. 8,
each helical groove 24a, b extends from a lower end 74 to an upper end 76
and includes a first portion P1 having a first axial length L1, and a
second portion P2 having a second axial length L2. In a preferred
embodiment, first portion P1 has a first helical angle .alpha.
corresponding to a small first axial length L1, whereas second portion P2
has a second helical angle .beta. corresponding to a large second axial
length L2. Helical grooves 24a, b can also include a locking detent 77 to
lock piston 14 into place in its snares-on position. In one embodiment,
detent 77 is formed by a slightly upturned portion of helical groove 24a,
b at leading end 74 into which follower 26a, b settles.
In one embodiment, first portion P1 extends around between about 60.degree.
and about 120.degree., and preferably about 90.degree. of piston surface
22, or about half of the turn of each helical groove 24a, b, and second
portion P2 extends around the remainder of helical groove 24a, b so that a
follower 26a, b following helical groove 24a, b from the snares-on
position to the snares-off position will first slide along first portion
P1 and then along second portion P2.
A small helical angle .alpha. or .beta., corresponding to a small axial
length L of helical groove 24, allows for easier tuning of the vertical
position of piston 14 because piston 14 is moved by a small amount as
actuator 18 is rotated. Conversely, a large helical angle .alpha. or
.beta. corresponding to a large axial length L of helical groove 24 allows
piston 14 to be adjusted quickly because piston 14 is moved by a large
amount as actuator 18 is rotated.
In one embodiment, helical angle a of first portion P1 is a small angle of
between about 10.degree. and about 20.degree., and preferably angle
.alpha. is about 15.degree. so that for a cylindrical piston 14 having a
diameter of about 11/16 inches the axial length L1 of first portion P1 is
about 1/10 inches. A relatively small angle .alpha. is preferred to allow
for tuning of strainer 10 in the tensed range where snares 8 will still
vibrate against lower drumhead 7 when snare drum 2 is played. A
predetermined helical angle .alpha. is selected so that it is small enough
to provide friction between top groove wall 42 and follower 26a, b that is
sufficient to prevent piston 14 from dropping prematurely to its
snares-off position.
Helical angle .beta. of second portion P2 can be between about 20.degree.
and about 30.degree., and preferably is about 25.degree. so that for an
11/16 inch diameter cylindrical piston 14, the axial length L2 of second
portion P2 is about 11/40 inches, so that the total axial length L of each
helical groove 24 is about 3/8 inches. A predetermined angle .beta. is
selected so that it is large enough to provide insufficient friction to
hold between top groove wall 42 and follower 26a, b, thus, piston 14
slides due to gravity and the tension of snares 8 as well as being biased
by actuator 18 until it is in the snares-off position.
In one embodiment, piston 14 includes a guiding groove 40 (FIG. 7A) for
receiving guiding follower 27 (shown in FIG. 6) to guide piston 14 as it
moves from its snares-on position to its snares-off position and to ensure
that piston 14 does not rotate with respect to housing 12 as followers
26a, b cammingly engage with helical grooves 24a, b. In a preferred
embodiment, guiding groove 40 runs generally axially along piston 14 and
has a width GW of between about 3/16 inches and about 1/2 inches,
preferably about 5/16 inches, a depth GD of between about 1/16 inches and
about 1/4 inches, preferably about 1/8 inches and a length GL of between
about 1/2 inches and about 9/10 inches, preferably about 7/10 inches for
an 11/16 inch diameter piston 14.
Snares 8 are operative connected to piston 14. In one embodiment, snares 8
are operatively connected to piston 14 via a snare clamp 16 mounted to a
lower end 46 of piston 14 so that when piston 14 moves from its snares-on
position to its snares-off position, snare clamp 16 also moves from a
first or snares-on position to a second or snares-off position. In a
preferred embodiment, shown in FIGS. 1 and 2, snare clamp 16 clamps a
strap 34 operatively connected to snares 8.
In one embodiment, snare clamp 16 includes a main portion 48 and a clamping
plate 50 mountable to main portion 48 with clamp screws 52. A tongue 54
can also be mounted to main portion 48, wherein tongue 54 is insertable
into a piston bore 56 in piston 14. A threaded rod 58 is insertable
through piston bore 56, as shown in FIG. 6, wherein threaded rod 58 can
threadingly engage a threaded hole (not shown) in tongue 54. In a
preferred embodiment, threaded rod 58 is also coupled to a knurled
adjustor knob 60 for fine tuning of the tension of snares 8. Adjustor knob
60 can be rotated so that threaded rod 58 rotates with respect to tongue
54 causing the effective length of snare clamp 16 and threaded rod 58 to
change, adjusting the tension in snares 8.
In a preferred embodiment, tongue 54 and a portion of piston bore 56 at the
lower end 46 of piston 14 have a cross sectional shape that prevents
rotation of tongue 54 with threaded rod 58 as adjustor knob 60 is turned.
In one embodiment, shown in FIG. 6, tongue 54 and piston bore 56 have a
generally hexagonal cross section while threaded rod 58 has a generally
circular cross-section sized to fit within piston bore 56 without
interference, so that threaded rod 58 will rotate easily within piston
bore 56, but tongue 54 will not.
Actuator
Returning to FIGS. 3B-5B, actuator 18 causes piston 14 to move from its
snares-on position to its snares-off position by cammingly engaging with
piston surface 22. In one embodiment, actuator 18 is retained within
recess 38 of housing 12 (shown in FIG. 6) so that actuator 18 is rotatable
around piston 14 so that actuator 18 can cammingly engage piston surface
22. In one embodiment, actuator 18 includes at least one follower 26a
insertable into helical groove 24a. In a preferred embodiment, wherein
there are two helical grooves 24a, b, as described above, actuator 18
includes two followers 26a, b for cammingly engaging with helical grooves
24a, b. Actuator 18 can also include a handle 62 having a knob 63 so that
a player of snare drum 2 can easily turn actuator 18 whenever it is
desired.
Preferably, actuator 18 is generally annular in shape, as shown in FIG. 6,
with an actuator bore 64 for surrounding piston 14. Followers 26a, b
extend radially inwardly into actuator bore 64 and into helical grooves
24a, b to cammingly engage with piston 14, best shown in FIGS. 3B through
5B. In one embodiment, followers 26a, b are extensions which extend
radially inwardly from actuator 18.
Turning to FIG. 6, the extensions can be formed from set screws 66a, b
which are threaded through actuator 18, wherein set screws 66a, b include
a head 68a, b and a shortened shank 70a, b that extends into helical
groove 24a, b to cammingly engage with groove walls 42 and 44. In a
preferred embodiment, shown in FIG. 6, followers 26a, b include a bearing
72a, b coupled with shank 70a, b of set screw 66a, b, wherein bearing 72a,
b engages with helical groove 24a, b to bias piston 14 from its snares-on
position to its snares-off position. Bearing 72a, b can be one of several
bearings known in the art, but preferably bearing 72a, b is an annular
roller bearing, as shown in FIG. 6, mountable on shank 70a, b of set screw
66a, b. A roller bearing 72a, b can easily | | |
