Note: Descriptions are shown in the official language in which they were submitted.
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MOTORIZED BALL TOY WITX IMPROVE:D TORQU15
Backaround and Summary o~ the Invention
The invention relates generally to amusement devices
and more particularly to a motorized ball toy capable of
traveling over generally planar surfaces by means of internally-
produced motive power.
Motorized ball toys with internal power supplies and
! lo motors have been configured in different ways to accomplish the
, goal of imparting rolling motion to a ball from within. In U.S.
, Patent No. 2,949,696 a ball with a hollow interior is fitted with
i an axial shaft extending diametrically across the interior of the
ball. The output shaft of a small electric motor engages a gear
on the axial shaft imparting relative rotation therebetween.
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Batteries for powering the motor are mounted eccentrically on the
axial shaft. The batteries weigh more than the motor and tend to
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overbalance it, which allows the motor to rotate the axial shaft
and the ball itself while the motor remains generally stationary
(i.e., nonrotating) relative to the shaft. A similar battery-
: driven ball is shown in ~.S. Patent No. 2,939,246. In that
patent, the motor and axial shaft power a toy ball which
incorporates a gravity actuated on-off switch. A similar drive
mechanism is also used in U.S. Patent No. 4,726,800, wherein the
ball toy is actuated by a small radio receiver and includes a
servo-motor which can change the center of gravity of the ball to
steer it. Finally, in U.S. Patent No. 3,722,134, a ball with a
hollow interior is propelled over flat surfaces by a small
wheeled vehicle which is freely movable (i.e., loose) within the
interior of the ball. The small wheeled vehicle is battery
powered and rolls ~round on the inside of the ball, changing itæ
~- center of gravity and imparting motion to the ball.
In the firæt three prior art motorized ball toys
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i;~ discussed above, an eccentrically-mounted weight is provided
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!'`' within the ball for the motor to impart torque to the axial
shaft. Eccentric mounting of the battery or batteries allows
!:: gravity to impart a necessary counter-rotative force on the drive
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motor of the ball, to which the batteries are operatively
3 connected, in order ~or the motor to exert torque on the shaft
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and turn the ball. Because the batteries in a drive mechanism of
a motorized toy ball are generally the heaviest part of the
mechanism, they greatly affect the weight distribution of the
10 drive mechanism about the axial shaft. In Patent Nos. 2,949,696,
~l 2,939,246 and 4,726,800, the battery or batteries are mounted
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offset from the axial shaft and provide eccentric weight
, distribution which makes the drive mechanism work. In Patent No.
3,722,134 the internal self-propelled vehicle within the ball
~;~ takes place of the driven shaft and the need for eccentric weight
distribution is eliminated.
A problem presented by prior art motorized ball toys
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which use the internal battery or batteries to provide an
eccentric weight distribution is that the battery or batteries
tend to be relatively large compared to the rest of the drive
mechanism, or to the ball itself. Consequently, they cannot be
¦ mounted near the interior wall of the ball because of its
~- curvature, which means the weight of the batteries cannot be
positioned very far from the axial shaft. If the weight
distribution of the drive mechanism around the axial shaft is
insufficiently eccentric, the ball's movement will be slow,
erratic and sluggish because the drive mechanism may counter-
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rotate around the shaft. Alternatively, the weight distribution
might be such that the ball will merely spin in place because it
is caused to rotate too ~ast. Both of these operating
characteristics have been present with prior art shaft-driven
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motorized ball toys.
It is an object of the present invention to provide a
motorized ball toy in which the drive mechanism imparts increased
torque to the axia' drive shaft. It would also be advantageous
to provide a motorized ball toy with enhanced eccentricity in the
weight distribution of the drive mechanism so the ball will
operate smoothly and with improved traction. It would also be
advantageous to have a motorized ball toy which is easily opened
for bat~ery installation or replacement.
Accordingly, a motorized ball toy which moves in
response to internal power is provided, comprising an outer wall
formed of a plurality of wall sections joined together. The wall
sections selectively interlock with one another to form an
assembled outer wall which is generally spherical. A central
shaft extends along a first axis across the interior of the outer
~, wall. The shaft is fixed to the outer wall such that rotation of
the shaft about the first axis produces a simultaneous rotation
of the outer wall about the first axis. A drive frame is
supported on the central shaft and is rotatable about the first
axis within the interior of the outer wall. A motor is suppoxted
on the drive frame and is operatively connected to the central
shaft for imparting relative rotation about the first axis
between the shaft and the drive frame. An inert mass is attached
to the drive frame at a predetermined distance from the first
axis whereby the torque imparted to the central shaft by the
i motor is increased.
In its preferred form, the motorized ball toy employs
an inert mass in the form of a zinc weight which is attached to
the drive frame at a point which generally maximizes the distance
between the central shaft and the zinc weight. The zinc weight
preferably has first and second surfaces on opposite sides
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thereof and is joined to the drive frame along the first surface.
Z The second surface is curved and has a circular cross section
which is generally concentric with the spherical surface of the
outer wall. Such a curved surface allows the zinc weight to be
positioned at a maximum distance from the central shaft,
immediately adjacent the interior surface of the outer wall.
Other features of the preferred embodiment of the
present invention include an outer wall made up of two
hemispherical sections which join together by means of mating
threads on the peripheral edge of each hemisphere. The central
Z shaft of the ball is supported at opposite ends by internal shaft
'~ mounts. One of the shaft mounts releasably engages the shaft and
, 1, the other shaft mount nonrotatably engages the chaft. Rotation
'~ of the shaft relative to the motorized drive frame is transferred
to the outer wall of the ball via the nonrotatable shaft mount.
` Brief Description of th~e Drawings
Fig. 1 is a perspective view of a motorized ball toy in
~'Z accordance with the present invention with the outer wall
schematically shown as transparent to permit the interior parts
to be viewed.
Fig. 2 is a partially exploded view of the motorized
, ball toy of Figs. 1 and 2.
'A Fig. 3 is a cross-sectional view of the motorized ball
$ toy of Fig~ 1 taken along lines 2-2 of Fig. 1.
Fig. 4 is a cross sectional view of a motorized ball
toy as in Fig. 2, taken along line 4-4 of Fig. 3 and illustrating
¦ ~ movement of the zinc weight during counter-rotation of the drive
, frame about the central shaft.
Detailed Description of the Preferred Embodiment
, 30 Referring to Fig. 1, the motorized ball toy of the
, preferred embodiment is indicated generally at 10. The outer
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wall 12 of ball 10 is made up of a plurality of wall sections
~oined together. The wall sections are preferably formed of
molded plastic or another suitable moldable material. Although
the outer wall sections of ball 10 are depicted as transparent in
Fig. 1, they may be opaque. Two hemispherical sections 14, 16
are illustrated. Hemispheres 14, 16 interlock with one another
along their respective peripheral edges 18, 20 (see Fig. 3), also
referred to as mating edges, by respective internal and external
mating threads 22, 24. When the two wall sections 14, 16 are
selectively assembled, the outer wall has the shape of a ball.
Also included in the depicted embodiment between
hemispheres 14, 16 is an 0-ring 45 which is positioned in an 0-
ring seat 43 in hemisphere 16. Alternatively, and perhaps even
preferably, the 0-ring can be positioned in a circumferentially
extending groove (not shown) in either of the hemispheres
ad~acent to the threaded portions, but offset by about 0.030
inch. In any event, the configuration and positioning of 0-ring
45 i8 such that it extends outwardly at least to the outer
surface of wall sections 14, 16, to provide a circumferentially
extending portion having increased friction to reduce the
likelihood that the ball will merely stay in place and spin upon
actuation of motive power.
Within the open interior 30 of ball 10, which is
encompassed by or within the wall sections 14 and 16, is the
drive mechanism for imparting rotational motion to the ball.
Referring to Figs. 1-3, a diametrical central shaft 32 extends
along a first axis 35 across the interior 30 of ball 10. First
axis 35 is preferably a spherical diameter which extends across
the center of ball 10. First and second shaft mounts 33, 34,
respectively, extend inwardly from the respective interior
surfaces 38, 40 of hemispheres 14 and 16. The shaft mounts are
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normally in the form of radially-extending sleeves integrally
formed of the same plastic material from which hemispheres 14, 16
are fabricated. They typically include strengthening fins 36, as
illustrated.
5haft 32 is preferably a steel pin which has a smooth
outside surface at its first end 42 and a nonsmooth outside
I surface at its second end 44, as is seen most clearly in Fig. 2.
The first end of the shaft is smooth in order to be releasably
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~ engaged by first shaft mount 33, which has a correspondingly
! j lo smooth surface on the inside 46 of the sleeve. This releasable
engagement normally results in the first drive shaft mount 33
~', nonrotatably engaging shaft 32 due to the friction fit. Of
, course, once the two hemispheres are threaded into each other,
there will be no relative rotation between the shaft and either
~ I hemisphere. Second end 44 of shaft 32 is preferably knurled or
¦ splined to be nonrotatably and normally nonreleasably engaged by
second shaft mount 34, which has an interior surface 48 designed
to nonslidingly engage the second end 44 of shaft 32. End 44 of
shaft 32 could also be keyed or otherwise fixed to shaft mount 34
in order to prevent mutual rotation therebetween. The purpose of
the nonrotatable engagement between shaft 32 and shaft mounts 33,
34 is to positively transfer any rotation of shaft 32 to
'~ hemisphere 16 and ball 10. The sliding connection between end 42
of the shaft and mount 33 is to permit the two halves 14, 16 of
ball 10 to be separated from one another for assembly and
~ disassembly of the ball. An enlarged flared or conical element
7 49 is, in the depicted embodiment, slipped over a cap 47
positioned over the first end 42 of shaft 32 when assembling the
ball to facilitate assembly of the two hemispheres 14 and 16, as
will be described below.
The drive frame 50 of the ball carries the motor which
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supplies its motive power. Drive frame 50 is centrally disposed
on shaft 32 and iæ supported on the shaft within the interior 30
~ of ball 10. The drive frame includes a motor support or housing
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7. 52, which is shown in two parts 52a and 52b in Fig. 2, for
supporting motor 54 on frame 50. Also supported on and partially
enclosed by housing 52 are several drive gears which form the
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:, operative connection between the drive shaft 56 of motor 54 and
central shaft 32. Such gears include a worm gear 58 keyed to
drive shaft 56, a dual-sprocket reduction gear 60 which meshes
with worm gear 58 and with a drive sprocket 62 keyed to central
~; shaft 32 on another knurled or splined segment 63 and adjacent
~, spacers 51 and 53.
Housing 52 supports a battery case 66, in Fig. 2 shown
as 66a and 66k, in which a conventional dry-cell battery 68 is
housed. Battery 68 provides power to motor 54 through wire
connections (not shown~. At one end of battery case 66 is a
closure/on-off switch mechanism 70 for retaining battery 68 in
case 66 and for turning on and off motor 54. A pair of fins 73,
75 extend from housing part 52b to alternatively be engaged by
slat 69 in mechanism 70, depending upon the position of the
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switch mechanism.
Mechanism 70 also includes an aperture 77 designed to
~'l receive a control wire (not shown) which extends from motor 54,
`~ through aperture 77, and through a hole in the left side SFig. 4)
¦ of mechanism 70, and then to the battery 68. Aperture 77 thus
acts to avoid entanglement of and possible damage to this wire.
Also included in mechanism 70 is a protrusion 65 which engages,
at one end of travel of switch mechanism 70, a battery case 66
0 (see Fig. 3) to prevent over-travel.
Drive frame 50, includinq battery case 66 and all the
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other parts attached to the drive frame, is sized to revolve
around shaft 32 within the interior 30 of ball 10. In other
words, if the ball is held in a manner which prevents its
rotation, drive frame 50 will revolve around first axis 35
whenever motor 54 is energized. Conversely, if the drive frame
is held in one orientation with the motor energized, it rotates
ball 10 about first axi~ 35.
At the lower end of drive frame housing 52, at
approximately the maximum distance from shaft 32 within ball 10,
0 i8 a zinc weight 76 which is attached to the housing. Zinc
weight 76 serves as an inert mass attached to the drive frame to
increase the moment of inertia of the drive frame and thus
increase the torque which motor 54 is able to impart to shaft 32
and ball 10. The term "inert mass" is used herein to distinguish
the zinc weight from a battery or batteries, which are active
components that serve another function in prior art motorized
ball toys, in addition to functioning as weights on some toys.
Zinc weight 76 preferably has a first surface 78 which faces and
is joined or mated to the bottom side 74 of the drive frame
housing. First surface 78 also includes several upwardly-
¦ extending lips 79 which extend around part of the sidewalls of
housing 52, adjacent bottom wall 74. Weight 76 also has a second
j surface 80 opposite the first surface, and second surface 80 is
preferably curved as is shown most clearly in Fig. 4. The curved
second surface 80 has a circular cross section which is generally
concentric with the spherical surface of the outer wall of the
~ ball. The curvature of second surface 80 maximizes the amount of
;~ mass which can be placed at the greatest distance from the first
axis 35 of central shaft 32. As such, it maximizes the
~ 30 eccentricity of the weight distribution of drive frame 50
! relative to shaft 32.
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The mass of zinc weight 76 and the distance it is
positioned from the axis of the central shaft can be selected to
determine the speed, traction and responsiveness of the motorized
ball. Generally, a motorized ball 2 1/2-inches to 5-inches in
diameter is designed to operate at speeds (over a flat planar
surface~ of from 0.3-feet-per-second to 8-feet-per-second, with a
apeed of from 1 to 4 feet per second preferred. In such a ball,
a zinc weight 76 with a weight in the range of about 10 to 60
gram6 i8 suitable, with 36.5 grams being preferred. The weight
should preferably be attached to the drive frame at a
predetermined distance from the axis 35 of central shaft 32, that
distance being slightly less than the internal or interior radius
84 of ball 10. In other words, the outside curved surface 80 of
weight 76 should approach but not touch the inside surface 38, 40
of ball 10 as drive frame 50 orbits around central shaft 32.
Operation of the motorized ball toy of the present
invention requires the user to unscrew the two halves 14, 16 of
the ball to access on-off switch 70. When separating left
hemisphere 14 (as viewed in Fig. 3) from right hemisphere 16, the
removable end 42 of shaft 32 with its cap 47 is slid out from the
receiving sleeve or opening 46 of shaft mount 33. Once the two
halves of ball 10 are separated, the shaft 32 and drive frame 50,
and all parts connected thereto, are supported only from right
hemisphere 16 on shaft mount 36. When switch 70 has been turned
on its pivot 71 to the "on" position to engage fin 75, drive
frame 50 will begin to orbit around central shaft 32 in the
direction of arrow 85 in Fig. 4. This "on" position is the
~! position illustrated in Fig. 4; the "off" position is not
l illustrated but would be in a different rotational position with
-~ 30 respect to pivot 71, and would result in engagement of fin 73 by
slot 69. The user then reassembles the two halves of the ball by
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sliding the ~lidable end 42 of pin 32 and its cap 47 past flared
or conical element 49 and into engagement with shaft mount 33.
This engages the mating threads 22, 24 on the ball hemispheres
and by relatively rotating these two halves the toy is fully
assembled.
Drive frame 50 will continue to orbit until the ball is
placed on a horizontal planar surface, at which time gravity will
tend to stabilize the drive frame with zinc weight 76 oriented
toward the bottom. As motor 54 turns the motor drive shaft 56,
torque is applied to shaft 32 via gears 58, 60 and 62, causing
i central shaft 32 to rotate about first axis 35 in a direction
!j opposite to arrow 85. The rotation of the shaft is transferred
to right hemisphere 14 via shaft mount 34 and with some
assistance from shaft mount 33, which causes ball 10 to rotate
with the shaft and drives the ball along the horizontal planar
surface. ~-~
When the ball strikes an object, a wall, or another
obstruction, the turning of the motor carries drive frame 50
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, around shaft 32 in counter-rotational direction 85 (see Fig. 4),
carrying zinc weight 76 up and over the top of the shaft. Once
the center of gravity of the drive frame has passed over the top
of shaft 32, ball 10 will tend to roll backwards from the
obstruction, change direction slightly and the process will
continue until a new unobstructed forward direction has been
determined for the ball.
In the preferred embodiment, most of the parts of
motorized ball toy 10 can conveniently be made of molded plastic.
Only shaft 32, zinc weight 76 and the electrical system of the
ball need be made of metal. The motorized ball toy can be
inexpensively manufactured and provides amusement to children,
adults and pets. Because zinc weight 76 shifts the center of
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gravity of the drive frame toward the outer periphery of the ball
to the extent that it is possible to do so, the motorized ball
toy of the present invention exhibits substantially more reliable
and steady motion than prior art motorized balls. In addition,
there are no loose parts which could collide with the interior of
the ball should it be dropped. The toy is easily assembled and
di~assembled and the double-end mounting of the central shaft
en~ures ruggedness and durability.
Alternative embodiments are possible within the scope
~ 10 of the present invention. For example, the number of outer wall
s sections which can be separated and joined together to form ball
10 can be modified within the scope of the invention. Three or
s more outer wall ~ections could be provided assuming that when all
s cections are interlocked with one another they form an assembled
outer wall which has the shape of a ball. The orientation and
configuration of the motor, reduction gears and other internal
parts of the drive frame can be modified within the scope of the
present invention. For example, the drive shaft of the motor,
which in the preferred embodiment is perpendicular to the central
shaft of ball 10, could be reoriented to be parallel with the
central shaft. These and other changes will occur to those
skilled in the art.
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