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Claims  |
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What is claimed is:
1. A pickup assembly for stringed instruments, comprising:
a first coil assembly defined by a first coil, said assembly further
comprising a first surface; and said first surface defined by at least one
first pad in electrical contact with first coil;
a second coil assembly defined by a second coil, said second coil assembly
forming an electrical circuit with said first coil assembly to create an
electromagnetic field through which said strings pass said second coil
assembly further comprising a second surface, said second surface defined
by at least one second pad in electrical contact with said second coil,
said pads cooperatively configured such that when said second coil
assembly is attached to said first coil assembly, said pads and said coils
complete a single electrical circuit, said pads and said coil assemblies
are further configured to permit said second coil assembly to be detached
from said first coil assembly, and whereby said second coil assembly may
be exchangeable with an alternate second coil assembly.
2. The pickup assembly of claim 1, wherein:
said first coil assembly comprises a plurality substantially parallel first
pole members, said first pole members further being parallel with a pole
axis; and
said second coil assembly comprises a plurality of substantially parallel
second pole members, said second pole members further being substantially
parallel with said pole axis.
3. The pickup assembly of claim 2, wherein:
said first pole members are included in said at least one first coil, said
first coil being mounted to a first coil housing; and
said second pole members are included in said second coil, said second coil
being mounted to a second coil housing, said second coil housing being
attachable to and detachable from said first coil housing.
4. The pickup assembly of claim 3, wherein:
each said first coil further comprises a pair of insulating plates, said
plates attached together to form an insulating frame, and first windings
formed by winding wire around each said frame; and
each said second coil further comprises a pair of insulating plates, said
plates attached together to form an insulating frame, and second windings
formed by winding wire around each said frame.
5. The pickup assembly of claim 4, wherein the length of wire comprising
said first windings is shorter than the length of wire comprising said
second windings.
6. The pickup assembly of claim 4, wherein:
said first coil housing further comprises a pair of parallel grooves
adjacent to said first mating surface; and
said second coil housing further comprises a pair of parallel tracks, said
tracks and grooves being configured to be interlockable.
7. The pickup assembly of claim 4, wherein said first coil assembly is
attachable to said stringed instrument and said second coil assembly is
slidingly attachable to, and detachable from, said first coil assembly.
8. The pickup assembly of claim 5, wherein said first coil assembly
comprises a substantially rectangular first coil housing having a mounting
surface opposite to said mating surface and at least two mounting tabs
adjacent to said mounting surface.
9. The pickup assembly of claim 5, wherein said second coil assembly
comprises a substantially rectangular second coil housing having a fin
extending towards said first coil housing.
10. A stacked pickup assembly for guitars, comprising:
a lower coil assembly attachable to said guitar and defined by a first
coil, said assembly further comprising a first surface; and said first
surface defined by at least one first pad in electrical contact with first
coil; and
an upper coil assembly defined by a second coil, said second coil assembly
forming an electrical circuit with said lower coil assembly to create an
electromagnetic field through which said strings pass, said upper coil
assembly further comprising a second surface, said second surface defined
by at least one second pad in electrical contact with said second coil,
said pads cooperatively configured such that when said upper coil assembly
is attached to said lower coil assembly, said pads and said coils complete
a single electrical circuit, said pads and said coil assemblies are
further configured to permit said upper coil assembly to be detached from
said lower coil assembly, and whereby said upper coil assembly may be
exchangeable with an alternate upper coil assembly.
11. The pickup assembly of claim 10, wherein:
said lower coil assembly comprises at least one lower coil, each said lower
coil comprising a plurality substantially parallel lower pole members,
said lower pole members further being parallel with a pole axis; and
said upper coil assembly comprises at least one upper coil, each said upper
coil comprising a plurality of substantially parallel upper pole members,
said upper pole members further being substantially parallel with said
pole axis.
12. The pickup assembly of claim 11, wherein:
each said lower coil further comprises at least one length of wire, each
said length formed into lower windings;
each said upper coil further comprises at least one length of wire, each
said length formed into upper windings; and
whereby when said upper coil assembly is attached to said lower coil
assembly, each said upper windings forms an electrical circuit with one
said lower windings.
13. The pickup assembly of claim 12, wherein:
said lower coils are enclosed in a lower coil housing, said lower coil
housing further comprising a mating surface defined by at least one pad in
electrical contact with said lower windings; and
said upper coils are enclosed in an upper coil housing, said upper coil
housing further comprising a mating surface defined by at least one pad in
electrical contact with one said upper windings said mating surfaces and
pads being cooperatively configured such that when said upper housing is
attached to said lower housing, each said upper pad and windings forms a
single electrical circuit with each said lower pad and windings.
14. The pickup assembly of claim 13, wherein length of wire comprising each
said upper windings is a different length than the length of wire
comprising each said lower windings.
15. The pickup assembly of claim 14, wherein said upper coil housing is
attachable to said stringed instrument and said second coil assembly is
slidingly attachable to, and slidingly detachable from, said first coil
assembly;
said lower coil housing further comprises a pair of parallel grooves
adjacent to said mating surface; and
said upper coil housing further comprises a pair of parallel tracks, said
tracks and grooves being configured to permit said upper coil housing to
slidingly engage said lower coil housing.
16. A stacked electromagnetic pickup system for stringed musical
instruments, said assembly permitting exchange of pickup modules while
said strings remain attached and in tune, comprising:
a lower coil module attachable to said guitar and defined by a first coil,
said module further comprising a first surface; and said first surface
defined by at least one first pad in electrical contact with first coil;
and
a plurality of upper coil modules, each said module defined by a second
coil and further comprising a second surface, said second surface defined
by at least one second pad in electrical contact with said second coil,
said pads cooperatively configured such that when one said upper coil
module is attached to said lower coil module, said pads and said coils
complete a single electrical circuit, said pads and said coil modules are
further configured to permit each said upper coil module to be detached
from said lower coil module, and whereby each said upper coil module may
be exchangeable with an alternate upper coil module, each said attached
upper and lower coil modules forming an electrical circuit and thereby
creating an electromagnetic field through which said strings pass.
17. The stacked pickup system of claim 16, wherein each said upper coil
module comprises a length of wire forming at least one winding, each said
module comprising a different length of wire than said wire length of
another said module. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the amplification of stringed
instruments and, more specifically, to an Exchangeable Stacked Pickup
Assembly and Installation for Stringed Instruments.
2. Description of Related Art
Electromagnetic field-type pickups have been available for stringed
instruments for a number of years. In the case of guitars, virtually every
contemporary musical group uses one or more guitars equipped with an
electromagnetic pickup. In fact, many musicians own more than one model or
type of "electric guitar" in order to obtain different sounds for
different musical pieces. Alternatively, the musician may have guitars of
the same model, but with different electromagnetic pickups in each. It is
this necessity for different guitars to obtain different sounds that is
the focus of the present invention.
FIG. 1 depicts a conventional electric guitar 10. While available in a wide
variety of configurations, the typical electric guitar 10 design includes
a plurality of typically metallic strings 12 running from the head 14 to
the bridge assembly 16. The strings 12 are located cooperatively with one
or more pickups 18, such that the pickups 18 will detect vibrations in the
strings 12 and convert these vibrations into an electrical current for
external amplification and other adjustments.
FIGS. 2A-2D depict common designs for pickups 18. FIG. 2A depicts a
conventional single coil pickup 20. Located within the pickup 20 is a
single electromagnetic coil 22 and a plurality of pole pieces 28, creating
a magnetic field therein. FIG. 2B shows a conventional dual coil pickup
24, having a pair of coils 22. As shown in FIG. 1, the pickups 20 and 24
can be oriented in various positions in relation to the strings (see FIG.
1). FIG. 2C shows a single coil pickup 20, similar to the pickup of FIG.
2A, but with a single bar magnet 23 in place of the plurality of pole
pieces 28. FIG. 2D shows a double coil 29, in which there is a single coil
winding 32, separated by insulating pieces 26, and in which there may be
two different types of magnets 23.
Now turning to FIG. 3, we might better appreciate a common prior coil 22.
As can be seen, this coil 22 comprises a pair of insulating plates 26
through which a plurality of pole pieces 28 pass. In this design, the pole
pieces 28 are magnetized such that either end has opposite polarity. The
polarity arrangement will create a magnetic field between the ends of the
pole pieces 28, depicted by the field lines 30. It should be appreciated
that the strings 12 pass through the magnetic field lines 30 as they pass
over the coil 22. Not all pole pieces 28 have the same magnetic qualities;
different magnetic characteristics and/or materials will result in
different fields 30 (or field strengths) for each particular string 12 and
pole piece 28 combination. The coil 22 also has coil windings 32, which
are, essentially, formed from a thin, continuous wire wrapped around the
pole pieces 28. The coil windings 32 pass through magnetic fields 30 of
all of the pole pieces 28, and could be made from a variety of metallic
materials, depending upon the desired sound.
In operation, therefore, vibrations of each metallic string 12 will create
fluctuations in the magnetic field 30 of the associated pole piece 28.
Fluctuations in magnetic field lines 30 are well known to create
electromotive forces resulting in electrical current in any electrical
wires located in and perpendicular to the field lines 30. As a result, the
vibrations created when a musician strums the strings 12 will cause
fluctuations in the magnetic fields 30 associated with that string 12, and
a current or voltage will be created in the coil windings 32 that is then
used by amplifiers and other devices to produce external sound through
speakers.
FIG. 4 gives further detail regarding the prior art. FIG. 4 is a cutaway
side view of the coil 22 of FIG. 3 as it might be installed within an
electric guitar. As can be seen, the pole pieces (see FIG. 3) typically
comprise a pole core 34 sheathed in a pole insulator 36, both of them
passing through the two insulating plates 26. It should be appreciated
that the pole insulator 36 and insulating plates 26 may be combined into a
single frame for the coil windings 32 (known as a "bobbin"). The coil 22
is either surface mounted on the face of the guitar 38, or it may be
located in a recess 40 formed within the face 38, depending upon the
particular guitar design. The coil 22 is installed such that the pole
distance 42 is adequate for the strings 12 to vibrate freely, while also
providing optimum sound output; this distance 42 is determined by the
guitar design, and may be adjusted to some extent by the musician.
It can be easily understood that different numbers of coil windings 32 (and
therefore wire lengths) that are on the coil 22 will result in a different
characteristic sound for that particular coil 22. It should be appreciated
that the pole distance 42 is insufficient to permit the coil 22 to be
removed without first removing the strings 12. This can be a very
time-consuming process, which is why musicians maintain more than one
guitar. The design depicted in FIGS. 3-4 are exemplary only; a wide
variety of other designs are known, including designs that combine
insulating pole pieces 28 and magnets located elsewhere in the coil 22.
What all have in common, however, is that the amplification of the sound
is created by currents or voltages created in the coil windings 32, and
that to change the guitar's sound characteristics, one must change either
the magnetic qualities of the pickup or the number of windings in the coil
22, or both.
What is needed, therefore, is a pickup system for stringed musical
instruments that permits the user to change magnet characteristics and/or
the number of coil windings without necessitating string removal and
subsequent guitar re-tuning.
Lace, U.S. Pat. No. 5,221,805 sought to solve this problem. The Lace device
is, essentially, a secondary magnet that is added on to the top of an
existing pickup. Lace states that the "add-on device . . . modifies the
operating characteristics . . . of the output signal of an electromagnetic
pickup" by changing the apparent characteristics of the pickup's magnetic
field. The problem with the Lace device is that it is limited in its
range. While changing the characteristics of the magnetic fields should
result in some change in the output signal, it will not permit the large
changes available by changing the number of coil windings, the coil wire
diameter, or the coil wire material. If a musician could change either the
magnetic field or the coil characteristics (i.e. number of windings, wire
diameter or material), or both, without needing to re-string the musical
instrument, that musician would truly be able to obtain virtually any
desired sound out of a single musical instrument.
SUMMARY OF THE INVENTION
In light of the aforementioned problems associated with the prior devices,
it is an object of the present invention to provide an Exchangeable
Stacked Pickup Assembly and Installation for Stringed Instruments. It is a
further object that the system and assembly permit the user to change
magnet characteristics and/or the number of coil windings without
necessitating string removal and subsequent guitar re-tuning. It is a
still further object that the pickup system include a lower coil assembly
for attaching to the face of a guitar, and an upper coil assembly for
attaching to, and detaching from the lower coil assembly. It is an object
that both the lower coil assembly and the upper coil assembly include
conventional pickup coil assemblies, and that they are in electrical
circuit when attached to one another. It is another object that the
preferred system include a variety of upper coil assemblies, each having
unique electromagnetic qualities, such that the user need only exchange
one upper coil assembly with another in order to effect a desired change
in sound to the stringed instrument.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention, which are believed to be
novel, are set forth with particularity in the appended claims. The
present invention, both as to its organization and manner of operation,
together with further objects and advantages, may best be understood by
reference to the following description, taken in connection with the
accompanying drawings, of which:
FIG. 1 is a perspective view of a conventional electric guitar;
FIGS. 2A-2D are a top and side views of conventional single- and dual-coil
pickups;
FIG. 3 is a partial cutaway perspective view of a coil of a conventional
pickup;
FIG. 4 is a cutaway side view of the coil of FIG. 3 as it might be
installed within an electric guitar;
FIG. 5 is a cutaway side view of a preferred embodiment of a stacked single
coil pickup of the present invention;
FIG. 6 is a perspective view of a preferred embodiment of a stacked dual
coil pickup assembly of the present invention;
FIG. 7 is a side view of the stacked dual coil pickup assembly of FIG. 6;
FIG. 8 is a top view of the lower coil assembly of the stacked dual coil
pickup assembly of FIGS. 6 and 7;
FIG. 9 is a bottom view of the upper coil assembly of the stacked dual coil
pickup assembly of FIGS. 6 and 7;
FIG. 10 is a perspective view of a preferred embodiment of the stacked
single coil pickup assembly of the present invention; and
FIG. 11 is a partial exploded perspective view of the upper coil assembly
of FIGS. 6, 7 and 9 (excluding the housing).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the
art to make and use the invention and sets forth the best modes
contemplated by the inventors of carrying out their invention. Various
modifications, however, will remain readily apparent to those skilled in
the art, since the generic principles of the present invention have been
defined herein specifically to provide an Exchangeable Stacked Pickup
Assembly for Stringed Instruments.
The present invention can best be understood by initial consideration of
FIG. 5. FIG. 5 is a cutaway side view of a preferred embodiment of a
stacked single coil pickup 42 of the present invention. The example shown
might be used to replace the prior coil shown in FIG. 4. In its depicted
form, the stacked single coil pickup 42 comprises a lower coil 44 which is
attached to the face of the guitar 38, such as in the recess 40 shown. The
lower coil 44 has many components in common with the prior coils (see
FIGS. 3 and 4), including the insulating plates and pole insulators (not
labeled, see FIGS. 3 and 4). What is unique about the lower coil 44 is
that it has an upper surface configured with a winding contact 46. The
winding contact 46 is, in its preferred form, a metallic contact pad that
is in electrical circuit with the lower coil windings 48. Also included in
the lower coil 44 is a lower pole core 49, which may be configured as with
the prior devices heretofore described. Furthermore, the lower coil 44 is
configured to be shorter than the prior art coil (see FIG. 4).
Attached to the top of the lower coil 44 is an upper coil 50, which may be
very similar to the lower coil 44, in that it has a conventional design,
such as insulating plates and pole insulators (not labeled, see FIGS. 3
and 4), upper coil windings 52 and an upper pole core 54. What is unique
about the upper coil 50 is that it includes an upper winding contact 56 on
its bottom that is in electrical circuit with the upper coil windings 52.
The lower winding contact 46 and the upper winding contact 56 are
configured such that they meet and complete an electrical connection when
the upper coil 50 is attached to the top of the lower coil 44. Once
connected, the upper coil 50 and lower coil 44 create, in effect, a single
coil. If the magnetic characteristics of the stacked coil pickup 42 are
identical in the combination to the coil 22 shown in FIG. 4, and if the
total wire length of the lower coil windings 48 plus the upper coil
windings 52 equal the wire length of the coil windings 32 of the coil 22
of FIG. 4, then the magnetic field 30 of the stacked pickup 42 and output
response of the stacked pickup 42 should be identical to the prior pickup
22 of FIG. 4.
What makes this design so powerful and unique is the ability to exchange
the upper coil 50 with an alternative upper coil 50 that has different
magnetic and/or coil winding 52 characteristics. Changes in these
characteristics will result in changes in the output signal of the pickup
42, and consequently, changes in the sound characteristics of the guitar.
It should be appreciated that each different upper coil 50 is designed to
be attachable and detachable from the lower coil 44 while not altering the
pole distance 42, and without requiring removal of the strings 12. Further
detail in regard to the installation and removal of the upper coils 50 is
provided below in connection with FIGS. 6-10.
FIG. 6 is a perspective view of a preferred embodiment of a stacked dual
coil pickup assembly 58 of the present invention. As should be understood,
the stacked dual coil pickup assembly 58 is designed to take the place of
the conventional dual coil pickup 24 shown in FIG. 2B. In this design, the
lower coil assembly 60 contains a pair of lower coils 44 mounted therein,
each being electrically connected to a lower winding contact 46. The lower
coils 40 are also defined by bar magnets 23 (or pole pieces, depending
upon the desired sound characteristics). The lower coil assembly 60
further may include a pair of mounting tabs 62 to attach the lower coil
assembly 60 to the guitar face (see FIGS. 4 and 5), either within a recess
(see FIGS. 4 and 5) or on the lower face plate 67 itself. The lower coil
assembly 60 (and, similarly, the upper coil assembly 64) may be assembled
by filling the housing 75 with epoxy or other filler once the face plate
67 and other components are inserted therein. Attachable to the top of the
lower coil assembly 60 is an upper coil assembly 64. The upper coil
assembly 64 contains a pair of upper coils 50. The upper and lower coils
50 and 60, respectively, are designed as described above in connection
with FIG. 5. As also depicted in this figure, the upper coil assembly 64
is preferably engaged and disengaged from the lower coil assembly 60 by
sliding it in the direction 66. As previously discussed, therefore, the
upper coil assembly 64 can be removed and replaced without removing the
strings (see FIGS. 4 and 5).
Other versions or embodiments of the present invention are conceived of;
for example, the lower and upper winding contacts 46 and 56 may be
metallic pads (as shown herein), or they could also comprise miniature or
sub-miniature electronic connectors, such as matched, interlocking male
and female "molex" connectors.
Now turning to FIGS. 7, 8 and 9, we can better understand the upper and
lower coil assemblies 64 and 44. FIG. 7 is a side view of the stacked dual
coil pickup assembly 58 of FIG. 6, provided to give further detail
regarding the means for attaching the upper and lower coil assemblies 44
and 64 to one another. The upper coil assembly 64 is preferably formed
with a track 68 running along its length on either side of the assembly
64, with a fin 70 formed at one end. The lower coil assembly 44 includes a
groove 72 formed along its length on either side and one end of the
assembly 44, that is configured to receive the track 68. To attach the
assemblies 44 and 64, one need merely to insert the track 68 into the
groove 72 and then slide the upper coil assembly 64 along the lower coil
assembly 44 until the depression 74 formed in the lower coil assembly 44
receives the fin 70.
FIG. 8 is a top view of the lower coil assembly 44 of the stacked dual coil
pickup assembly 58 of FIG. 7 along the line A--A. The lower coils 44 are
enclosed in, and attached to, a lower coil housing 75; the groove (see
FIG. 7) is formed along the upper edge of the lower coil housing 75. As
can be seen, the preferred mounting tab 62 extending from the lower coil
housing 75 may also be defined by an aperture 76 formed therethrough to
accept a mounting screw or the like to mount the lower coil assembly 44 to
the guitar. Also shown in this figure are the lower winding contacts 46,
that are preferably metallic pads attached to the top surface of the lower
face plate (see FIG. 6). Each lower winding contact 46 is electrically
connected to its respective lower coil 44 (i.e. its windings).
Furthermore, the lower coil assembly 44 may be permanently or removeably
wired to the other electrical components comprising the guitar's
amplification system.
FIG. 9 is a bottom view of the upper coil assembly 64 of the stacked dual
coil pickup assembly of FIG. 7 along the line B--B, provided to give
further detail regarding this assembly. The pair of upper coils 50 are
housed within and attached to the upper coil housing 80. The tracks (see
FIG. 7) are formed in the upper coil housing 80 such that they engage the
grooves (see FIG. 7) formed within the lower coil housing (see FIG. 8).
Also attached to the bottom side of the upper coil housing 80 are the
upper winding contacts 56. Like the lower winding contacts (see FIG. 8),
the upper winding contacts 56 are preferably metallic pads attached to the
housing 80 and electrically connected to their respective upper coil 50
and positioned to connect with the corresponding lower winding contact
(see FIG. 8) when the upper coil assembly 64 is slidingly attached to the
lower coil assembly (see FIG. 8). Furthermore, as with the lower coil
assembly (see FIG. 8), the upper winding contacts 56 are preferably
attached to the upper face plate 81.
FIG. 10 indicates how a single coil pickup might be provided by the present
invention. FIG. 10 is a perspective view of a preferred embodiment of the
stacked single coil pickup assembly 84. Like the dual coil embodiment, the
stacked single coil pickup assembly 84 comprises a lower coil assembly 86
that attaches to the stringed instrument, and an upper coil assembly 88
which slidingly attaches to the lower coil assembly 86 such that the upper
winding contact (not shown) is placed in electrical contact with the lower
winding contact 46. The lower coil assembly 86 may further be defined, as
here, by a pair of mounting tabs 92 for attaching the lower coil assembly
86 to the guitar or other stringed instrument.
FIG. 11 gives further detail of the present invention; it is an exploded
perspective view of the upper coil assembly 64 of FIGS. 6, 7 and 9
(excluding the housing). The upper face plate 81 comprises a substantially
rigid plate having at least one slot 94 configured to accept the bar
magnets 23 (or pole pieces) therethrough. In a single coil embodiment,
there would be one-half as many slots 94 (or other apertures). The face
plate 81 has an outer face 96 and an inner face 98. The upper winding
contacts 56 are attached to the outer face 96 of the face plate 81, and
configured such that they will contact the lower winding contacts (see
above) when the upper coil assembly is attached to the lower coil
assembly. The upper face plate 81 may further comprise printed circuits on
its surface(s) to provide electrical connection to the various components
mounted thereon, as well as to external circuitry. The upper coils 50, as
previously discussed, reside over the bar magnets 23 to provide the output
current necessary for amplification of the guitar's sound.
It should be apparent that the present invention is an appropriate
replacement for virtually any type of current electromagnetic pickup,
including both passive and active pickups.
Those skilled in the art will appreciate that various adaptations and
modifications of the just-described preferred embodiment can be configured
without departing from the scope and spirit of the invention. Therefore,
it is to be understood that, within the scope of the appended claims, the
invention may be practiced other than as specifically described herein.
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