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Description  |
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FIELD OF THE INVENTION
A. Background of the Invention
The present invention relates to a mobile music stand rack and method
whereby music stands of more or less conventional design can be
conveniently positioned on the rack and removed therefrom, and the rack
with the stands can conveniently and safely be moved to storage location
for the stands.
B. Background Art
A conventional design for a music stand which has been in existence for
many, many years is one that has a rectangular platform or panel which is
positioned at an inclined angle, on the top of an adjustable support
column or post, with the post being supported from a base which is
commonly made up of three legs extending outwardly from a center location
at 120.degree. angles with respect to one another.
Quite often, these music stands are used for musical instruction at an
educational institution or by musical groups or orchestras. It often
becomes necessary to set up the music stands for music practice (or a
musical performance) and then remove the music stands from that location
for storage. There have been designs where the music stand is collapsible
(thus facilitating storage).
An alternative approach has been to store the music stand in its existing
configuration. One such music stand cart or rack is shown in U.S. Pat. No.
4,315,633 (Boeddeker et al), and also in Des. No. 268,140 (Tenner). This
is a mobile music cart, having a forward and rear pair of ground engaging
wheels, supporting forward and rear frame sections. There are upper and
lower parallel pairs of longitudinal mounting rods which slant at an angle
of about 30.degree. to the horizontal. The music stands are placed in this
cart for storage by lifting the stand to the height of the upper end of
the rack and placing an upper column portion of the stand between the
upper rods, and one arm or member of the base support in the passageway
defined by the lower two rods. Each stand is moved from the upper location
of the two sets of rods downwardly and forwardly to a lower end location.
The music stands are positioned one against the other and in somewhat
nested fashion until the rack is full.
There are a number of other types of mobile storage carts that appear in
the patent literature. Among these are the following:
U.S. Pat. No. 4,221,395 (Carte) shows a trailer designed to carry hurdles
which are used in track meets for the hurdle races. This trailer comprises
a longitudinally extending elongate beam having stanchions 21 standing
upwardly from the beam and transverse arms 22. The hurdles are mounted on
the arm members on opposite sides of the beam, and the forward end of the
beam has a socket type hitch 18 by which the trailer is towed.
U.S. Pat. No. 3,955,926 (Riedesel) shows a mattress carrier having a
horizontal platform supported by front and rear wheels and a rectangular
framework positioned on top of the platform.
U.S. Pat. No. 2,311,422 (Walling) shows a "janitor's cart". This is a
wheeled cart having an upstanding framework to carry instruments, and also
a trash carrying location.
U.S. Pat. No. 1,912,264 (Stannard) shows a wheeled rack to carry chairs.
There is a rectangular frame having front and rear wheels. Opposite sides
of the rear edge of the chair seat have hook members 31 and 32 thereon,
and when the seat is in a folded position, these hook members 31 and 32
are in an upper position to rest upon side rails and thus support each
chair in the rack.
When music stands are used in an undergraduate educational institution
(high school, junior high school, or even in grade school), it often
happens (particularly where there is not a dedicated "band room" where the
music stands might be left in place for weeks at a time) that it is
necessary to store the music stands, take them out again for practice,
store them again, etc. This task often is performed by the students or
others who are not practiced in this task, possibly in a rush, or
inattentive in the details of the task. Also, some of the younger students
(possibly a small girl) may be somewhat lacking in physical size or
strength to be able to handle conveniently, even a relatively simple task
such as moving a music stand into a storage rack. Accordingly, it is
desirable that such a music storage device (particularly a movable or
mobile music stand storage device) be convenient, reliable and "user
friendly". Even if there is a dedicated band room where the music stands
are set up, in many instances the music stands are stored at the end of
the day so that custodial chores could be accomplished, such as sweeping
the band room floor.
Also, when the music stand rack is being moved from one location to the
other, it needs to be relatively stable, and also should be easy to
maneuver.
Further, from a structural and manufacturing perspective, it is desirable
that the basic design to accomplish the objectives noted above should be
such that the loading on the structural members be such that there can be
achieved economy in the design, and also so that the manufacture and
assembly can conveniently be accomplished.
SUMMARY OF THE INVENTION
The music stand storage rack of the present invention is arranged to
support a plurality of music stands comprising an upper laterally
extending panel section, a vertical support column, and a base having
support means extending outwardly from the lower end of the support
column. The storage rack has a front end, a rear end, and a forward to
rear extending longitudinal center axis.
The rack comprises a central longitudinally extending support guide section
which comprises the following. There is an upward guide section comprising
a pair of laterally spaced, horizontal upper guide rods defining
therebetween a substantially unobstructed passageway to receive an upper
portion support columns of the music stands, and having upwardly facing
support surfaces to engage lower position edges of the panel sections of
the music stand. There is also a lower longitudinally extending lower
support means, providing an elongate upwardly facing support rod means to
engage a lower central surface portion of the base if the music stands.
There is a forward frame section connected to the upper guide rods to the
lower support rods means. The forward frame section presents an
unobstructed entry area leading into the passageway of the upper guide
rods and also has laterally spaced side support members defining a forward
open area sufficiently wide to permit the base of the music stand to pass
therethrough. There is a rear frame section connected to the guide rods
and to the lower support rod means. The rear frame has a stop means
positioned adjacent to the guide rods and adjacent to the rear frame
section. The support surfaces of the guide rods are spaced above the
support means of the lower rod means by a vertical distance less than a
vertical distance between a lower central support portion of the base and
the lower position edges of the panel section. This is done in a manner
that a forwardmost music stand can be supported on the rack with the base
of the forwardmost music stand resting on the lower support rod means at a
slant to the vertical, and with the panel section resting on the upper
guide rods. The forwardmost music stand is prevented by stop means from
passing unobstructedly out the rear end of the rack.
There is a pair of rearwardly spaced ground support wheels positioned at
central support locations of the rack on opposite sides of the rack and
constrained for rotation along horizontal transverse axes.
There is a forward swivel mounted ground engaging wheel mounted at the
front end of the rack and centered on the longitudinal axis. There is also
a rear swivel mounted ground engaging wheel positioned at the rear end of
the rack and centered on the longitudinal axis.
The rear frame section is arranged to define a through opening at the rear
end of the upper guide rods to permit the column of the music stand to
pass out of the rear end of the rack. The rear frame section is arranged
to provide a rear opening sufficiently large to permit passage of the
panel section and base of the music stand.
In the method of the present invention, a music stand rack is provided as
indicated above. The music stands are stored by moving each stand through
the front frame with the column moving into the passageway between the
upper guide rods. The music stands are stored in a slanting position, with
the base supported by the lower rod means, and the panel resting on the
upper guide rods.
Also in the method, the music rack is maneuvered by pivoting the music
stand about an axis extending transversely between the two side wheels.
Other features of the present invention will become apparent from the
following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view showing the music stand rack of a first
embodiment of the present invention, with a load of music stands mounted
to the rack in a stored position;
FIG. 2 is an isometric view similar to FIG. 1, but not showing the music
stands.
FIG. 3 is a side elevational view of the rack of FIGS. 1 and 2;
FIG. 4 is an isometric view similar to FIG. 2, showing a second embodiment
of the present invention;
FIG. 5 is a side elevational view of the second embodiment of FIG. 4;
FIG. 6 is an isometric exploded view of the first embodiment, showing the
component parts disassembled and in position to be assembled;
FIG. 7 is a schematic top plan view of the rack of the present invention,
illustrating the manner in which the vertical loads are carried by the
rack of the present invention;
FIG. 8 is a view similar to FIG. 7, illustrating the manner in which
turning forces are reacted in the rack; and
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, there is shown a first embodiment of the music stand rack 10,
with a near full load of music stands 12 mounted thereon. It is believed
that a clearer understanding of the present invention will be achieved by
first describing briefly the prior art music stands 12 which are stored on
the rack 10, and then presenting a more detailed description of the rack
10.
The music stands 12 shown herein are typical of many music stands that have
been in the prior art for many years. As shown, these comprise a base 14,
a support column 16, and a music support panel 18 which is pivotally
mounted at 20 to the upper end of the column 16. The base 14 is commonly
made up of three elongate feet or support members 22 which extend radially
outwardly from the lower part of the column 16 at 120.degree. angles from
one another. The support column 16 can be constructed to be vertically
adjustable.
The panel 18 comprises a main rectangularly shaped panel section 24, and
there is a lower support ledge or flange 26 which extends at right angles
from the lower edge 28 of the panel section 24. In FIGS. 1 and 5, each
panel section is shown having been folded down to its stored position
where the flange 26 is at an upwardly positioned location.
The music stand rack 10 comprises a rear support frame 30, a forward
support frame 32, an upper elongate guide section 34 and a lower support
section 36. There are rear and forward center swivel mounted ground
support wheels 38 and 40, respectively, each mounted for a full
360.degree. rotation about a vertical axis, and two side wheels 41
laterally spaced from one another and positioned at a mid-length of the
rack 10.
The front support frame 32 has a generally rectangular configuration and
comprises a lower bar 42, two side bars 44 rigidly connected to and
extending upwardly from opposite ends of the lower bar 42, and two upper
bar sections or arms 46 connected to the upper ends of the side bars 44
and extending laterally inwardly toward one another. The inner ends 48 of
the two arms 46 are spaced about three inches from one another and define
a center opening 50 to receive an upper part of the support column 16 of
the music stands 12.
Mounted to the middle of the lower bar 42 are two upstanding, laterally
spaced arms 52. These arms 52 perform two functions. First, they provide
support for the lower support section 36. Second the upper ends 54 of
these vertical arms 52 provide a stop to prevent the base of an adjacent
stand 12 from accidentally moving outwardly from its storage position on
the rack 10. Each of the arms is held in place by suitable mounting
brackets 56.
The upper guide section 34 comprises two horizontal, parallel, laterally
spaced, elongate guide bars 58, the front ends 60 of which are rigidly
connected to the inner ends 48 of the arms 46. The rear ends 62 of the
arms 58 are fixedly connected to the aforementioned rear support frame 30.
The rear frame 30 has a rectangular configuration which has the same
overall size and shape as the front frame 32. Specifically, there is a
lower horizontal bar 64, two side bars 66, and a single upper bar 68
extending entirely across the width of the rear frame 30 and fixedly
connected to the upper ends of the side bars 66.
Fixedly attached to the middle lower part of the lower horizontal bar 64
are two upstanding stop arms 70 which have upper end portions 72 that are
able to engage the base 14 of the rearmost music stand 12. Also these arms
70 connect the the lower support section 36.
Fixedly attached to the upper bar 68 is a push handle 76, comprising an
upper horizontally extending push bar 78, and two vertical mounting struts
80 that attach by their upper ends to the bar 78 and by their lower ends
to the bar 68.
Each of the rear and forward wheels 38 and 40 is mounted to a related
swivel assembly 82 bolted to a respective one of the lower bars 64 and 42.
The swivel assemblies 82 are or may be conventional. The two side wheels
41 are rotatably mounted to a transversely horizontally extending axle 84
that is connected to and positioned below the support section 36. This
axle 84 connects to the lower ends of two vertically extending arms 86,
the upper ends of which connect to, and support, the center part of the
support section 36.
The aforementioned support section 36 comprises two laterally spaced
longitudinally extending bars 88 that are positioned directly below the
two upper rods or bars 60. The rear and front ends 90 and 92 of each bar
88 are fixedly connected to the rear and forward arms 70 and 52,
respectively.
The entire music stand rack is made as a substantially rigid structure
(except of course for the wheels 38, 40 and 41).
To describe the manner in which the music stands are stored on the rack 10,
initially, the panel 18 is rotated about the pivot mounting 20 to the down
position as shown in FIG. 1. Then each music stand 12 is lifted off the
floor, and the upper part of the column 16 is moved into the entryway 50
and into the passageway 93 defined by the two upper bars 60. At the same
time, the base 14 is moved over the stop members 54 and above the two bars
88 that comprise the lower support section 36. This can be accomplished
either by moving the forwardmost support member 22 through the lower
opening 96 defined by the two arms 52. Alternatively, the arms 22 can be
positioned to straddle the two bars 88. Each stand 12 is moved toward the
rear end of the rack 10.
The forwardmost stand 12 is positioned so that the panel section 18 rests
against the two bars 80. The main support for the stand 12 is provided by
the base section 14 resting on the lower support section 88. The
downwardly positioned edges 98 of each panel section 18 rests on the upper
guide bars 60. Then subsequent music stands are mounted onto the rack in
the same manner, and this can be accomplished until the rack is
substantially filled.
It is to be noted that the manner in which the music stands 12 are loaded
onto the rack 10 causes the weight of the stands to be equally distributed
on both sides of a center axis 100 of the support rack 10, the reason for
this being that the support column 60 is constrained to be positioned
within the upper guide bars 60 and rests at a central location on the
lowermost support section 36.
Also, the support rack 10 itself is built symmetrically so that its center
of gravity is also aligned on the center axis 100. Thus, the front and
rear support wheels 38 and 40, being positioned on the center axis 100,
are necessarily positioned along a line vertically aligned with the center
of gravity of the rack 10 itself, when empty, and also aligned with the
center of gravity if the rack 10 is either partially loaded (as in FIG.
3), or fully loaded (as in FIG. 1). The significance of this will be
discussed further below.
To illustrate certain functional features of the rack 10, reference is now
made to FIG. 7 which is a somewhat schematic top plan view of the support
rack 10, where the rack 10 is shown as a rectangle, the four wheels 38, 40
and 41 are shown, and also the longitudinal center axis 100. Let us assume
that the rack 10 is fully loaded with music stands. As indicated above,
the music stands are constrained to be symmetrically loaded so that the
center of gravity 102 is on the center axis 100, at (or very close to) a
transverse axis passing through the two side wheels 41.
As the support rack 10 is pushed forwardly along a straight line parallel
to the center axis 100, it can be appreciated that the rack 10 with the
music stands 12 mounted thereon is quite stable. Any forward to rear
tipping is resisted by either the rear or front wheel 38 or 40. Any side
tipping is resisted by one or the other of the side wheels 41. Since the
center of gravity 102 is at the center of the rack 10, this offers
substantial stability.
However, let it be assumed that there is some sort of diagonal load,
exerted, for example, along the line indicated at 104 in FIG. 7. It will
be noted that the more distant wheels 41 and 40 define a ground engaging
axis 106 about which the rack 10 could tend to tip. However, it can be
seen that the center of gravity 102 is positioned a significant distance
from the axis 106, so that substantial stability is provided when the rack
is subjected to this kind of a force. Obviously, a lateral load (indicated
by the arrow 108) at the center of rack 10 is resisted by the far side
wheel 41.
It often happens that the tipping of most any sort of mobile cart or rack
is most likely to occur when a turning maneuver is attempted. Analysis
will indicate that the forces created by a turning movement with the
present invention are reacted in a manner to not only provide stability,
but also make the turning more easily accomplished. This will be explained
further below.
Since the rear and forward wheels 38 and 40 swivel, and since the side
wheels 41 are constrained to permit movement in only forward and rear
directions, any rotation about a vertical axis of the cart 10 is
constrained to rotate about a transverse, horizontal axis, to occur along
a line passing through the two side wheels 41. Since the center of gravity
102 is at, or at least very close to the actual geometry center of the
cart 10, for purposes of discussion, we will simply consider the point 102
as the geometric mid-point of the storage rack 10.
With reference to FIG. 8, let us examine the lateral forces exerted in a
simple turning motion where the storage rack 10 is being pushed in a
forward direction, and it is desired to make a 90.degree. turn. The person
who is grasping the push bar 78 would exert a lateral force at that
location, this being indicated by the arrow 110. If we ignore for purposes
of analysis the linear movement of the rack 10, we can consider the center
of rotation to be about the center point 102. For the moment, let us
ignore the effect of friction, such as might occur from the swivel mounted
wheels 38 and 40 being caused to rotate, and also the small amount of
friction provided by the side wheels 41.
The main resisting force to this turning force 110 are the two inertial
forces provided by the front and rear portions of the loaded rack 10, with
the music stands 12 loaded thereon. The front half is indicated at 112,
and the rear half at 114. The transverse center axis is indicated at 115.
The front section 112 has a center of inertia indicated at 116,
approximately mid-way between the rear end of the rack 10 and the
transverse center axis 114. In like manner, the front portion of the rack
has a center of inertia at 118 approximately mid-way between the
transverse center axis 115 and the front end of the rack 10.
The inertial force at 116 is exerted into the rack 10 in a direction
opposite to the moving force 110, and this inertial force is indicated at
120. On the other hand, since the rear half portion 114 of the rack 10
rotates in a direction opposite to that of the front half 112, the
inertial force at 118 is in the opposite direction, and this inertial
force is indicated at 122. Since the distance from the point 116 to point
102 and also the distance from the point 118 to the center point 102 is
half the distance of the location of the handle 78 to the center point
102, and since the moments must balance around the center location 102
(the moment being equal to the force times the length of the moment arm),
analysis indicates that the force 110 would be equal to the force 120 and
also equal to the force 122.
However, in addition to the moments balancing, it is necessary that the
lateral forces balance. Analysis indicates that the total lateral force
resulting from the turning force (indicated at 110) exerted on the handle
78 would necessarily be reacted entirely at the location of the one side
wheel 41 that is in the outside of the turn. This lateral resisting force
is indicated at 124 and it is equal to the force 110.
A preferred embodiment of the storage rack of the present invention has a
total length dimension of six feet. Thus, with the turning axis being at
the center 102, this turning maneuver can easily be accomplished about a
relatively short turning radius, and in a more confined turning area. If
we assume a given rate of forward speed (e.g. two to three miles per
hour), and if a turn about a given radius is to be made, it can be seen
that because the handle at 78 would be moved a relatively short distance
in an arc laterally (in comparison with a conventional cart where there
would be a set of turning wheels at either the front or the rear end of
the carts), a relatively small turning force would have to be applied to
the storage rack 10 of the present invention.
The above explanation is somewhat simplified. The actual force moment which
would tend to tip the rack 10 over (ignoring for the moment any
centrifugal force that would act on any cart or rack which is traveling
forwardly and making a sharp turn) would result in large part from the
lateral force 110 being exerted at a higher location (i.e. at the handle
10) and the inertial forces in the rack 10 and the music stands 12 mounted
thereon, and also how there are reacted into the ground engaging wheels.
However, regardless of the accuracy of the above analysis, actual use of
the rack 10 (when loaded) verifies its ability to be maneuvered easily
while remaining quite stable.
To discuss another benefit of the present invention, let us now look at the
structural loading in the rack 10, as shown in FIG. 2. Most all of the
weight is carried by the two lower bars 88. These elongate bars or rods 88
are supported at three locations, namely the location of the rear wheel
38, the forward wheel 40, and at 10 the axle 84. Assuming that the music
stands 12 are distributed substantially evenly over the length of the two
bars 88, approximately one half of the weight is carried by the middle
wheels 81, with a quarter of the weight being carried at the end swivel
wheels 38 and 40. In effect, both the front half and the rear half of the
elongate support rods or bars 88 act as beams. These "half length" beams
carry one half the weight over one half of the span. Thus, the bending
moments on the front and rear half of the bars 88 are reduced by one
quarter, in comparison to a situation if there were no middle wheels 41 at
all. In actuality, the bending moments are even somewhat less than one
quarter, since the rods 88 are continuous, and in the area where these
rods 88 extend over the two vertical support struts 86, there is a reverse
bending moment. Thus, in addition to this arrangement of the wheels 38, 40
and 41 contributing to the mobility and convenience of the rack 10, these
also contribute to carrying the load more effectively through the load
bearing members 88.
In addition, these rods 88 serve another function, and that is that any
laterally directed rotational movement of either the front frame 42 or the
rear frame 68 are transmitted into the rods 88 and thence through the
struts 86 into the axle 84 and into the side wheels 41, these causing the
lateral force to act at the location of the wheels 41.
The second embodiment of the present invention is illustrated in FIGS. 4
and 5. Components of the second embodiment which are similar to components
of the first embodiment of FIGS. 1 through 3 will be given like numerical
designation, with an "a" suffix, distinguishing those of the second
embodiment. It can be seen that the front frame 32a and the lower support
section 36a are substantially identical to the corresponding components 32
and 36 in the first embodiment of FIGS. 1 through 3. Also, the wheels 38a,
40a, and 41a are substantially identical to the corresponding components
of the first embodiment of FIGS. 1 and 2.
The two upper guide bars 58a differ from the guide bars 58 of the first
embodiment in that at the forward end there is a pair of upright stop
members 150. The reason for this is that the rear end of the two guide
rods 58a is open at 152. These stop members 150 position the most rearward
music stand and prevent it from passing out from the end opening at 152,
unless it is first lifted a short distance.
The rear frame 30a has a somewhat different configuration. There is a lower
rod 64a, and two side rods 66a. However, the two side rods 66a extend
upwardly to a higher level and connect to an upper cross-bar 78a which
essentially serves two functions. First, the cross bar 78a connects to the
two vertical rod members 66a to form a rigid rectangular frame with the
lower bar or rod 64a. Second this bar 78a serves as the steering bar, and
thus serves the same function as the bar 78 in the first embodiment of
FIGS. 1 through 3.
There are two arms 154 which extend inwardly to connect at 156 to the rear
ends of the two guide rods 58a. Thus, it can be seen that these arms 154
serve substantially the same function as the arms 46 of the first
embodiment
The mode of operation of this second embodiment of FIGS. 4 and 5 is
substantially the same as in the first embodiment with regard to travel,
maneuverability, and stability of the rack 10a. Also, the basic method of
loading is substantially the same as in the first embodiment, except that
in the second embodiment, the stop members 150 engage the music stand
panel 18 and thus position the music stands 12.
The main difference is in the unloading the music stands 12. The area above
the bars 154 and below the upper bar 78a is sufficiently large that it
enables the panel 18 of the music stand 12 to pass through. Thus, it
becomes readily apparent that the rack 10a can be unloaded from both the
front and the rear. Also, it would be possible to simultaneously load from
the front and the rear. For example, when the loading takes place from the
front, the music stands 12 could be moved half way down the length of the
rack 10a. At the same time, several music stands 12a could be moved into
the storage position through the rear opening 152, and after a number of
these are in place, they could simply be tilted in an upward and rearward
slant. Other techniques could be used also.
FIG. 6 illustrates the storage rack 10a of the first embodiment, with the
components in a preassembled arrangement. The front and rear frames 32 and
30 are welded as unitary structures. The guide rods 60 are connected by a
cross bar 160 (which can also function as a stop member) and these are
provided as a unitary structure. The two support rods 88 are each fixedly
attached to the forward 52 and rear 70 arms. The axle 84 is provided
separately.
It can be seen that these components are joined by a variety of nuts and
bolts, some of which are indicated at 160, along with washers 162 and
cotter pins 164 as needed. Also, there are end caps 166 provided at
various locations to close the open ends of the various bars or rods that
are welded together. Since the manner in which these components can be
connected and assembled is readily apparent from a viewing of FIG. 6,
these will not be described further herein.
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