U.S. patent application number 10/091126 was filed with the patent office on 2003-06-05 for pneumatic ball propulsion apparatus.
Invention is credited to Holke, William Lewis, Smith, William Kirby.
Application Number | 20030101978 10/091126 |
Document ID | / |
Family ID | 25546015 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030101978 |
Kind Code |
A1 |
Smith, William Kirby ; et
al. |
June 5, 2003 |
Pneumatic ball propulsion apparatus
Abstract
An apparatus that propels a ball pneumatically is provided with
an adapter for imparting spin to the ball. In a further aspect, the
apparatus can be provided with a position adjuster that cooperates
with a ball exit tube of the apparatus. A further aspect is
directed to a platform that allows the apparatus to be supported on
a ladder-like device. A pneumatic projectile propulsion apparatus
is capable of achieving high speed with a simple and practical
structure.
Inventors: |
Smith, William Kirby;
(Barrington, IL) ; Holke, William Lewis;
(Barrington, IL) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Family ID: |
25546015 |
Appl. No.: |
10/091126 |
Filed: |
March 4, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10091126 |
Mar 4, 2002 |
|
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|
09999205 |
Nov 30, 2001 |
|
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Current U.S.
Class: |
124/69 ;
124/71 |
Current CPC
Class: |
F41B 11/57 20130101;
A63B 69/38 20130101; A63B 2102/14 20151001; A63B 69/409 20130101;
F41B 11/68 20130101; A63B 2069/402 20130101; A63B 69/0002 20130101;
A63B 69/0024 20130101; A63B 71/00 20130101; A63B 69/0015 20130101;
A63B 2102/22 20151001 |
Class at
Publication: |
124/69 ;
124/71 |
International
Class: |
F41B 011/00 |
Claims
What is claimed is:
1. An adapter for imparting spin to a ball projected from an
apparatus that propels a ball pneumatically from an exit tube,
comprising an engaging member that extends beyond an exit end of an
exit tube and extends into a path of a ball propelled from the exit
tube.
2. The adapter of claim 1, comprising a plurality of engaging
members.
3. The adapter of claim 2, wherein the engaging members are mounted
on a tubular member that engages an exit tube of an apparatus that
propels a ball pneumatically.
4. The adapter of claim 2, wherein the engaging members comprise a
bendable and resilient core and a covering.
5. The adapter of claim 4, wherein the core is made of metal.
6. The adapter of claim 5, wherein the covering is made of
rubber.
7. The adapter of claim 4, wherein the core has a free end and the
cover extends beyond the free end of the core.
8. The adapter of claim 4, wherein at least one lateral groove is
provided in a ball-contacting surface of the covering.
9. In an apparatus that pneumatically propels a ball from an exit
tube, the improvement comprising an engaging member that extends
beyond an exit end of an exit tube and extends into a path of a
ball propelled from the exit tube.
10. A position adjuster for an exit tube of an apparatus that
propels a ball pneumatically from an exit tube, comprising: a first
member; and a second member for engaging an exit tube of an
apparatus that propels a ball pneumatically from an exit tube, the
second member being relatively movable with respect to the first
member.
11. The adjuster of claim 10, wherein the first member comprises a
T-shaped slot and the second member comprises an aperture, the
adjuster further comprising an elongate fastener comprising a first
end that extends through the aperture of the second member and a
second end that engages the slot in the first member.
12. The adjuster of claim 11, wherein the first end of the fastener
is threaded and he adjuster further comprises a bolt threaded on
the threaded first end.
13. A platform for an apparatus that propels a ball pneumatically
from an exit tube, comprising: a first surface for supporting an
apparatus that propels a ball pneumatically from an exit tube; and
first and second engaging members for engaging a ground-contacting
device, provided on a second surface opposed to said first surface;
at least one of the engaging members being movable with respect to
the other of the engaging members.
14. The platform of claim 13, further comprising a pair of parallel
grooves for carrying the movable engaging member.
15. The platform of claim 14, wherein the first and second engaging
members are movable.
16. The platform of claim 14, wherein the grooves have recessed
sidewalls.
17. A pneumatic projectile propulsion apparatus, comprising: a
pressure canister for containing a supply of air for pneumatically
propelling a projectile, comprising an exit tube through which a
projectile is expelled; a hopper for supplying projectiles to the
canister; and a blower for supplying air to the canister, wherein
the blower is a single electric motor blower that draws less than
15 amps of current, and the apparatus is capable of propelling a
tennis ball-sized or baseball-sized projectile at a speed of at
least 90 mph.
18. A pneumatic projectile propulsion apparatus, comprising: a
pressure canister for containing a supply of air for pneumatically
propelling a projectile, comprising an exit tube through which a
projectile is expelled; a hopper for supplying projectiles to the
canister; a cover that contains a blower for supplying air to the
canister, the cover being disposed in the hopper, an outlet of the
blower being in fluid communication with the canister.
19. A pneumatic projectile propulsion apparatus, comprising: a
pressure canister for containing a supply of air for pneumatically
propelling a projectile, comprising an exit tube through which a
projectile is expelled; a hopper for supplying projectiles to the
canister; and a cover that contains a blower for supplying air to
the canister, the canister being carried by the cover and the
hopper being carried by the canister.
Description
[0001] This application is a continuation-in-part of Ser. No.
09/999,205 filed Nov. 30, 2001, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention is directed to an apparatus for
pneumatic propulsion of a ball. Further, the present invention
provides an apparatus that is capable of propelling a ball
pneumatically with high accuracy at speeds useful for baseball and
softball batting training and the like. The present invention also
allows spin to be imparted to a pneumatically-propelled ball.
[0003] Devices that propel a ball by means of a mechanical arm or
rotating disks generally have been used for baseball and softball
training. These devices have not been satisfactory in providing
high-speed propulsion with sufficient accuracy. Devices that use
pneumatic propulsion for tennis training also have been known.
These also have not been sufficiently accurate for baseball and
softball training. In addition, past devices have not had the
capability of imparting spin to a projected ball reliably, thereby
limiting the ability of the devices to provide training conditions
that fully correspond to situations actually faced by participants
in sports like baseball, softball and tennis.
SUMMARY OF THE INVENTION
[0004] The present invention provides an apparatus capable of
projecting a ball pneumatically with sufficient accuracy, e.g. for
baseball and softball training purposes. The present invention
further provides an apparatus that allows fine adjustments in the
direction in which a ball is propelled. The present invention
further provides an apparatus capable of imparting spin to a
pneumatically projected ball. The present invention further
provides an apparatus that is capable of adjustment of the speed at
which a ball is projected pneumatically. The present invention
further provides an apparatus that is capable of projecting a ball
at a velocity of at least 90 mph (145 kph), preferably at least 100
mph (160 kph) using a single blower motor requiring no more than 15
amps of power. The present invention further provides training
methods that make use of one or more of the various aspects of
apparatus that are discussed above.
[0005] The invention is described in more detail below. The present
invention is not limited to the specific embodiments described
below. Modifications will be apparent and are intended to be
encompassed by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a ball propulsion device
according to an embodiment of the present invention.
[0007] FIG. 2 is a perspective view of a ball propulsion device
according to another embodiment of the present invention.
[0008] FIG. 3A is a sectional view of an aim adjusting element
useful with the present invention, while FIGS. 3B and 3C are
perspective views of members that are used in the aim adjusting
element.
[0009] FIG. 4A is side view of a spin imparting element useful with
the present invention, while FIGS. 4B and 4C are top and side views
of one of its pieces.
[0010] FIG. 5A is a top perspective view of support platform for a
ball propulsion device and FIG. 5B is a bottom perspective view
thereof. FIG. 5C is a top perspective view of a second embodiment
of the support platform.
[0011] FIGS. 6A and 6B are side and front perspective views of a
ball propulsion device according to another embodiment of the
present invention.
[0012] FIG. 7 is a side view of a ball propulsion device according
to another embodiment of the present invention.
DETAILED DESCRIPTION
[0013] The present invention will be described below with reference
to the accompanying drawings. The present invention is not limited
to the specific aspects of the invention discussed below.
[0014] The general configuration of a pneumatic ball propulsion
apparatus according to the present invention is illustrated in
FIGS. 1 and 2. Referring to FIG. 1, the apparatus 10 includes a
hopper 12 that contains balls (or other projectiles) to be
propelled, and a pressure canister 13 to which a blower is
connected for supplying air to the interior of the canister. The
blower can be connected to a convenient power source to supply
electricity to the blower motor. The canister is provided with an
exit tube 14, through which a ball is expelled after the canister
is pressurized. The inner diameter of the exit tube generally will
be about the same as or only slightly larger than that of the ball
being propelled. The angle of the exit tube can be changed to
adjust the trajectory of the expelled ball. The balls in the hopper
are delivered to the interior of the canister one-by-one with a
rotating carousel that has apertures for accepting and carrying
individual balls. The carousel delivers the ball to a tube, through
which the balls are fed by gravity to the interior of the canister.
If desired, provision can be made for automatic delivery of
projectiles from the hopper to the canister at regular intervals,
for "on-demand" delivery of projectiles from the hopper to the
canister, e.g. by permitting remote control operation of the
carousel. The same device can be capable of either mode of
delivery. In addition, projectile delivery intervals can be
controlled by blocking certain of the projectile-accepting holes in
a rotating carousel. For example, blocking every other hole will
double the interval between projectile deliveries.
[0015] The apparatus in FIG. 1 generally will be set on the ground.
The apparatus needs to maintain the proper orientation to deliver
balls from the hopper to the carousel and from the carousel up to
and through the delivery tube. The legs supporting the canister can
be made adjustable to accommodate unevenness of the ground. In
addition, the legs of the hopper can be made adjustable in order to
allow the hopper to maintain the proper orientation for delivering
balls to the canister. Further, a support for the apparatus,
discussed below, can be provided with a step that accommodates some
unevenness of the ground. The capability for elevation adjustment
also can be built into the rear base of the apparatus.
[0016] In use, balls to be propelled are delivered from the hopper
to the interior of the canister through a tube, and carried to the
exit tube. The exit tube is provided with a resilient seal that is
capable of expanding radially outward, which engages the ball to be
propelled. The seal may be in the shape of a ring and holds the
ball in place during pressurization of the canister. The seal may
be in the form of a ring-shaped rubber member held within the tube,
acting as a barrier to the passage of the ball or other
projectile
[0017] The continued supply of air to the canister causes pressure
to build behind the ball, which in turn increases the force applied
to the seal by the ball. When the force applied by the ball exceeds
the resilient force of the seal, the inner surface of the seal is
forced outward. When the inner surface of the seal is forced
outward sufficiently to permit the ball to pass, the ball is
expelled through the exit tube by the compressed air in the
canister. Devices that use this principle for the pneumatic
propulsion of tennis balls are known, for example devices marketed
by "LobSter", and therefore more detailed description of their
operation is omitted.
[0018] The air pressure and volume accumulated behind the ball when
it is expelled from the exit tube determine the speed at which the
ball is propelled. This can be varied by changing the
characteristics of the seal, e.g. dimensions and/or materials. In
addition, different capacity blowers, multiple blowers and/or
larger canisters can be used as necessary to provide sufficient air
pressure and volume for the desired speed. The canister can have a
cylindrical shape, but other shapes can be used if desired. An
example of useful dimensions for the canister are a diameter of
about 10-16 inches, preferably about 11 inches and a length of
about 14-24 inches, preferably about 16 inches. The canister
generally will have a volume of at least about 1200 cc, preferably
at least about 1500 cc. Such volumes are useful for projecting
balls and the like at speeds suitable for sports training, such as
for baseball training at a collegiate level or higher. For
practical reasons of portability and handling, it is desirable if
the maximum volume is less than about 3500 cc, preferably less than
about 2500 cc. The present invention may be applied readily to
other pneumatic ball propulsion systems that make use of an exit
tube and is not limited to the system described above.
[0019] The exit tubes for pneumatic ball propulsion systems
typically have exit tubes that are no more than about 21 inches (53
cm) in length. For the present purposes, this length is determined
as the distance from the point at which the ball is released (the
seal location in the above embodiment) to the exit end of the tube.
While this may provide sufficient accuracy for purposes such as
tennis, it may not provide sufficient accuracy at higher speeds for
purposes such as baseball and softball training, where location
accuracy on the order of a few inches (cm) or less at a distance of
40 feet (13 m) or more (about 54 feet (17 m) in the case of
simulating a release point for baseball training) is desired.
[0020] In order to provide improved accuracy and speed, an
apparatus in one aspect of the present invention uses an extension
tube 16. The extension tube 16 preferably is secured to the exit
tube 14 with a seal 17, for example a lock pin seal, to provide a
substantially airtight connection. Clamps, tapped connections,
threaded connections, tape and other devices can be used as
appropriate. Alternatively, the exit tube 14 can be formed of a
sufficient length to provide the desired accuracy and velocity. The
length necessary for achieving a particular accuracy will change
depending on the speed of the balls. For purposes of ball speeds in
a range of about 40-65 mph (about 65-105 kph), the exit tube length
should be at least about 15 inches (about 35 cm), preferably at
least 20 inches (about 50 cm). The extension tube 16 illustrated in
FIG. 1 has a length of about 21 inches (about 53 cm), and provides
an exit tube length of about 27 inches (about 68 cm). For higher
ball speeds, longer exit tube lengths are necessary. For example,
for ball speeds as high as 75 mph or 90 mph (120 kph or 145 kph) or
more, an exit tube length of 4 feet (1.3 m) or more may be needed.
For example an extension tube 18 in FIG. 2 has a length of about
4.5 feet (1.5 m). Generally, the exit tube should be the shortest
length that provides the desired accuracy and speed, as an
excessive tube length can cause ball speed to drop. It is desirable
to optimize the exit tube length with respect to speed and accuracy
for the intended application.
[0021] In a preferred embodiment, the exit tube will have a length
from 2.5 feet (0.8 m) to 5.5 feet (1.7 m), particularly 3 feet (1
m) to 5.5 feet (1.7 m), more particularly 3 feet (1 m) to 5 feet
(1.5 m), and more particularly 4 feet (1.3 m) to 5 feet (1.5 m).
This is especially useful for baseball training.
[0022] It also may be desirable to use an exit tube whose exit end
has a color that provides an enhanced visual focal point for
someone using the apparatus for training. For example, the exit
end, and particularly the end face of the tube facing the user,
could be painted (or otherwise colored) in a fluorescent red color.
Other colors might be used if desired.
[0023] For high level training, especially in sports such as
baseball or tennis, and which can include vision training, it is
desirable to project a ball at speeds of about 100 mph (160 kph)
and higher. While it is possible to achieve speeds of about 140 mph
(220 kph) and higher with a reasonably practical canister size by
using multiple blower motors, this suffers from practical drawbacks
in terms of requiring special electric circuitry or dual wires to
separate power sources on different circuits, and renders such
apparatus useful only in relatively specialized applications.
Therefore, in one aspect of the present invention, the ball
projecting apparatus is capable of projecting a ball at a speed of
at least 100 mph (160 kph), for example in a range from about 50
mph to 105 mph (80 to 170 kph) and makes use of a single blower
requiring no more than 15 amps of current. An example of a suitable
blower is the Ametek Model 117500-12 blower available from Lamb
Electric of Kent Ohio, which is a 7.2 inch (183 mm) fan diameter
three-stage tangential bypass discharge blower that can operate on
a typical "house" voltage of 120 volts, drawing no more than 15
amps of current. Such a blower has a maximum airflow of about 102.5
cfm for general motor performance and is capable of supplying a
canister discussed above with a pressure of about 4-7 psi,
preferably about 5-7 psi, more preferably about 5-6 psi, which is
sufficient to propel a tennis ball-sized projectile at a speed of
over 100 mph (160 kph) at the volumes noted above. The use of a
single motor blower drawing less than 15 amps of current is
particularly useful for in baseball and softball training.
[0024] It is possible to allow for changing the ball speed for a
given tube length by providing selectively openable apertures on
the exit tube. Opening an aperture on the exit tube results in the
loss of some of the compression, thereby decreasing the ball speed.
When a plurality of such apertures is provided, the options for
varying ball speed increase. Opening more apertures, or increasing
the effective size of an aperture, reduces the ball speed more. A
short tube piece with selectively openable apertures can be used to
provide the option of speed variation as an add-on feature. The
selectively openable apertures also could be in the form of one or
more simple holes that can be covered selectively by an operator,
for example using finger(s). For example, this allows for
simulation of change-ups and other off-speed pitches for baseball
or softball training.
[0025] The embodiment of FIG. 2 shows an apparatus that is
elevated. The apparatus 10 may be supported on a ladder-like device
20. A tripod 22 may be used to support the end of the extension
tube 18. This configuration is advantageous in that the ball exit
point is similar to the point where a baseball would be released
when thrown by a pitcher. The height and angle of propulsion can be
varied as desired, e.g. to simulate a ball thrown from a pitcher's
mound. While the apparatus 10 is set on a platform in FIG. 2, it
would be possible to provide adjustable legs or the like as part of
the apparatus 10 itself, or a tripod-like support structure with
adjustable elevation (e.g. by a crank) could be used for more
convenient transport. A step-up device like a ladder is useful
because it facilitates access to the propulsion device, e.g. to
clear jams. Ladders such as the Costco Prodeck III ladder or the
Costco Pro Fold Deluxe ladder are examples of useful devices. It
may be necessary to provide a platform, for example one as shown in
FIGS. 5A-C discussed below, to provide proper support for the
apparatus. When the apparatus is elevated, it may be useful to
provide one or more viewing apertures in the sidewall of the hopper
12, which allows an operator to assess the status of projectiles in
the hopper, e.g. number remaining, possible misfeeding, etc. The
viewing aperture may be on the order of 0.75 to 2 inches (2 to 5
cm) in diameter, preferably about 2 inches. The apertures can be
open or covered with a transparent material if desired.
[0026] Elevating the apparatus 10 may be useful for other types of
training besides baseball training. For example, an elevated
apparatus could be used to simulate a tennis serve. This generally
would require more elevation than for baseball training, and the
elevation can be selected as appropriate for a particular
activity.
[0027] A position adjuster 38 (FIGS. 3A-C) may be provided to
permit close control over the direction of the propelled ball. In
one embodiment, the position adjuster 38 can include a first member
40 and a second member 42 that is capable of relative movement with
respect to the first member 40 to permit position adjustment, and
also is capable of being secured to the first member 40 to prevent
relative movement. It is desirable to provide finger tip and
pinpoint control. The second member 44 is adapted to engage the
exit tube (or an extension tube) of the apparatus 10. In the
illustrated embodiment, this is accomplished by providing a
U-shaped cut-out in the second member 44. The exit tube or
extension is carried in the cut-out. Other engagement systems can
be used as desired.
[0028] One example of a system permitting the relative movement
between the first and second members is illustrated in FIG. 3A. In
this embodiment, the first member 42 is provided with a T-shaped
slot 42. A fastening member 48 has a head that is engaged in the
slot 44, and extends through an aperture 46 in the first member 44.
As one example, the fastening member may have a threaded end, and a
threaded bolt 50 engages the threaded end of the fastening member.
The bolt may take the form of a knob, wing nut or the like for ease
of operation by hand, and the term bolt is intended to cover
structures of this general type. The bolt can be tightened to
secure the first and second members together and can be loosened to
permit movement between the two, i.e. by virtue of the fastening
member sliding in the slot.
[0029] The direction of position adjustment is determined by the
orientation of the slot. In the embodiment FIG. 1, the slot is
oriented vertically to permit fine control of the height of the end
of the extension attached to the exit tube. In the embodiment of
FIG. 2, the slot is oriented horizontally to permit fine control of
the ball projection direction. The illustrated embodiment of FIGS.
3A-C can be considered to be infinitely adjustable. Other
infinitely adjustable systems may be suitable, or systems that have
step-wise adjustment also may be useful.
[0030] The first member 40 is provided with a suitable support. In
the case of an embodiment like that of FIG. 1, the first member 40
is provided with an appropriate base that rests on the ground. In
the case of an embodiment like that of FIG. 2, the first member is
carried by a device such as a tripod, which can be used to provide
vertical adjustability.
[0031] The illustrated embodiment permits adjustment in one
direction. However, it is possible to apply this aspect of the
present invention to a system that permits adjustment in two
directions. For example, a first member 40 provided with a
horizontal slot could in turn be provided with an aperture that
accepts a fastening member extending from a vertical slot carried
by a third member that is otherwise essentially identical to the
first member.
[0032] The first and second members of the position adjuster may be
made of any suitable material, such as plastic, wood, metal,
ceramic, etc. A metal member may be used to define the slot in the
first member if desired. For example, a metal member of the desired
cross section may secured to a slot in the first member. It should
be noted that the position adjuster can be adjusted by hand or
driven, e.g. with motor-driven gearing or a motor-driven rack and
pinion arrangement, or pneumatically, e.g. with compressed air
taken from the canister. Remote control of the position adjuster
may be useful in some cases.
[0033] Another aspect of the present invention permits a spin to be
imparted to a pneumatically-propelled ball. An example of this
aspect is illustrated in FIGS. 4A-C. In this embodiment, at least
one engaging member 26 is provided at an exit end of an exit tube,
and has a portion that extends into the ball ejection path from the
exit tube. The engaging member briefly grips the ball as it is
expelled from the exit tube, thereby imparting spin to the ball. By
imparting spin to the ball, it is possible to simulate pitches like
a curve ball, slurve ball or slider, or to provide more realistic
practice situations for other ball sports like tennis.
[0034] It is preferred to provide more than one, and more
preferably two, engaging members in order to impart spin with
greater certainty and reproducibility. In one aspect of the
invention, two independent engaging members are provided. This
allows the ready and independent adjustment of the spacing between
the engaging members and pressure applied by the engaging members,
thereby permitting variation in the nature of the spin imparted to
the ball. However, the engaging members instead may be joined
together if desired. In addition, the engaging members may be
formed integrally with the tube end.
[0035] The engaging members may be mounted directly on the exit end
of the exit tube if desired. However, if the engaging members are
mounted on a separate tube that itself is secured to the exit tube,
there are advantages through the ability to change the direction of
the spin imparted to the ball. Thus, in this embodiment, two
engaging members 26 are mounted on a tube 28 with clamps 30 to
provide a spin adapter assembly 24. The clamps 30 may be of a screw
hose clamp type, for example. The tube 28 can be configured to
cooperate with the exit end of the exit tube in any suitable
manner. For example, a clamping sleeve that fits over both the end
of the end of the tube 28 and the end of the exit tube, and
preferably is provided with separate clamping members such as screw
hose clamp mechanisms at both ends of the sleeves, can be used.
Loosening the clamping mechanism at the tube 28 side permits
relative rotation between the tube 28 and the exit tube, which
changes the circumferential position of the engaging member(s) with
respect to the exit tube, and permitting the ready variation in the
direction of spin imparted to the ball. This makes is possible to
simulate different game situations easily.
[0036] Providing the engaging member(s) on the tube 28 also has the
advantage of readily imparting or not imparting spin to the ball as
desired, i.e. by including the tube 28 in or removing the tube 28
from the exit tube assembly as desired. When the engaging member(s)
is mounted on a separate tube 28, the tube 28 preferably will be
relatively short, e.g. on the order of about 4 inches (10 cm), so
that the tube 28 does not affect the ball propelling properties of
the exit tube significantly. The inner diameter of the tube 28
should correspond to that of the exit tube.
[0037] The engaging members preferably are stiff and resilient
enough to engage the projected ball sufficiently to impart spin but
without significantly impeding the propulsion of the ball from the
exit tube or changing the ball's direction (other than through the
action of the spin during the ball's flight). The nature of the
materials forming the engaging members, the amount by which the
engaging member extends into the ball exit path, and the angle at
which the ball contacts the engaging member, i.e. the amount of
hook at the end of the engaging member, can be selected
appropriately to achieve this. It is desirable that the engaging
members be bendable to permit changes in their configuration,
thereby facilitating the changes in the spin imparted to the
projected ball.
[0038] In one example, the engaging members are formed from a
resilient and bendable metal core 32 and a flexible sleeve 34, for
example made of a flexible rubber. In one example, the metal core
can be 3/8 inch outer diameter (about 1 cm) copper pipe. The rubber
sleeve may be 5/8 inch outer diameter (about 1.7 cm) flexible
reinforced rubber tubing, such as that used for fuel lines.
[0039] It is desirable that part of the metal core be exposed, as
this will permit more secure connection between the engaging member
and the tubular member on which the engaging member is mounted.
When the copper pipe is used as the metal core, the exposed end can
be flattened to provide additional security in the connection. It
may be desirable to have the rubber sleeve extend beyond the end of
the metal core. In one embodiment, the rubber sleeve extends about
2 inches (5 cm) beyond the free end of the metal core. The rubber
sleeve can be provided with lateral grooves 36 to improve the
gripping of the ball to impart spin. Also, a soft, absorbent
abrasive may be incorporated in the ball-contacting surface to
improve the gripping. For the present purposes, the indication that
a sleeve or covering extends beyond the end of the core should be
understood to mean that the end of the sleeve or covering is beyond
the end of the core by a distance greater than the thickness of the
material forming the covering or sleeve along the length of the
core.
[0040] A further aspect of the present invention, illustrated for
example by FIGS. 5A-C, provides a platform for the apparatus 10
that can engage a ladder-type support. The platform 52 has a
support surface 54, on which the apparatus 10 will sit during use.
The support surface is surrounded by a lip 56, which inhibits
movement of the apparatus off of the support surface 54 due to
vibration and the like. If desired, the support surface 54 can be
provided with a low shelf upon which one set of legs of the
apparatus can rest, which can help provide the desired orientation
to the apparatus when it is sitting on the support surface.
[0041] Referring to the bottom view of FIG. 5B, blocks 60 are
provided for engaging a ladder-like device on which the platform 52
is to be mounted. One or both of the blocks 60 may be adjustable
with respect to each other. In the embodiment of FIGS. 5A and B,
both blocks 60 are carried in grooves 58. An individual block is
carried by a parallel pair of grooves. A threaded fastener may be
used, which engages the sidewalls of the groove and extends through
the block 60. A bolt similar to that discussed above for FIGS. 3A-C
may be used to tighten the block in place or loosen it for
adjusting movement. The sidewalls of the groove may be recessed so
that the fastening member does not extend above the level of the
support surface 54.
[0042] When both blocks are adjustable, the degree of adjustment
and utility of the platform with different devices is increased.
However, when more limited adjustability is acceptable, only one of
the blocks may be adjustable. For a platform that is intended for a
specific application, it may be acceptable to have both blocks
fixed. The blocks may be provided with horizontal lips to provide
more secure engagement with a ladder-type device, but this can
reduce the usefulness of the platform with a variety of different
devices.
[0043] In many cases, it is desirable for the apparatus 10
essentially to be centered on the platform. For some specific
applications, for example depending on the configuration of the
structure on which the platform is to be mounted, there may be some
advantage in having the apparatus positioned closer to one side. An
example of this is shown in FIG. 5C. In this embodiment, a support
surface 62 extends beyond the area for the apparatus 10, which is
defined by the lip 56. In this embodiment, only a single adjustable
block 60 is provided. The other block is fixed, for example near
the edge of the support surface 62 outside of the lip 56. In
particular, the use of a support structure that carries the
apparatus in an off center relationship to the crown of a ladder
might be useful in reducing the chances of immediate collapse or
falling of the ladder in the event of failure of the ladder's
support at the end of the platform. That is, if the apparatus is
positioned so that more weight is on the side of the crown opposite
to a side that is supported by arms from the ladder, there is less
likelihood of an immediate downward collapse should one or both of
the arms fail, fail to lock properly, etc.
[0044] As exemplary dimensions useful for a platform to support a
"LobSter" pneumatic ball propulsion device, the support surface 54
may be about 17.5 inches square (about 44 cm). The lip may be about
2 inches (5 cm) high. An extended support surface 62, for example
useful with the Costco Prodeck III ladder or the like, is about 23
inches by 19 inches (57 cm by 47 cm). The area within the lip 56 is
about 12 inches by 19 inches (30 cm by 47 cm). If both blocks 60
are adjustable, providing a range of spacing between the blocks 60
from about 13 inches to 19 inches (32 cm to 47 cm) is suitable for
use with a wide variety of ladder-like devices. The blocks 60 may
be about 3 inches high (7.5 cm).
[0045] The various aspects of the pneumatic ball propulsion
apparatus are useful in training methods for sports making use of a
ball, such as baseball, softball, tennis and cricket, particularly
for baseball and softball. In these training methods, the ball or
other projectile will be projected in the general direction of a
person wielding an implement such as a bat or racket that is
intended to make contact with the projectile. In addition, they may
be useful for training in other activities, e.g. for training for
goalkeepers in sports such as hockey and lacrosse. While the
illustrated embodiment is useful for propelling tennis balls, the
invention can be adapted to other balls, such as baseballs,
softballs, pickle balls and wiffle balls, and to non-ball
projectiles as well.
[0046] Further aspects of the ball propulsion apparatus are
discussed below. In each of these further aspects, the ball
propulsion apparatus operates under the same general principle
discussed above for the apparatus shown in FIGS. 1 and 2, i.e.
delivery of projectiles to a canister and an increase of pressure
behind the projectile until sufficient pressure is built up to
expel the projectile through the exit tube. The discussion of
details of the extension tubes, speed-controlling apertures,
position adjusters, spin-imparting members, and support platforms
above also applies to these further aspects of the ball propulsion
apparatus and is not repeated.
[0047] In the ball propulsion apparatus shown in FIG. 6A and B, a
pressure canister 64 carries a hopper 66 for holding and delivering
balls or other projectiles, e.g. by gravity, to the canister. The
hopper carries a cover 68, which houses a blower. The cover can be
provided with ventilation holes for the blower if necessary. In one
example, the blower can be secured to the hopper, e.g. with bolts
or the like extend through the hopper sidewall and/or bottom. In
addition or instead, one or mounting brackets can be secured to the
hopper, with the blower secured to the mounting bracket(s). The
cover also can be secured to the hopper by screws or the like that
extend through the sidewall and/or bottom. The blower expels air
through outlet 69 to tubing 70, which delivers the air to the
canister 64. The tubing can be made of any suitable material, e.g.
flexible tubing as is commonly used in pulling a vacuum or other
tubing such as pvc tubing, depending on the specific application.
Tubing connections can be secured, for example, with automotive
hose clamps or the like as needed. The canister 64 is provided with
suitable legs or other supports to allow it to sit securely on the
ground or on an elevated platform, and these can be made adjustable
to ensure a suitable angle and orientation for feeding projectiles
from the hopper to the canister. The blower can be, for example,
the Ametek Model 117500-12 discussed above, and the apparatus can
deliver a tennis ball-sized or baseball-sized projectile at a speed
of at least 90 mph (145 kph), preferably at least 100 mph (160 kph)
using a single blower that draws no more than 15 amps.
[0048] In the ball propulsion apparatus shown in FIG. 7, pressure
canister 72 carries a hopper 74. In this case, cover 74 for a
blower acts as a support for the canister and hopper. The cover may
be of a parallelepiped configuration, although to provide improved
stability it might be useful if the bottom of the cover is larger
(i.e. covers a larger area) than the top. The bottom of the cover
can be larger in the front-to-back and/or side-to-side direction.
It may be desirable to have the top sloped relative to the bottom,
i.e. sloping downward from front to back, to help ensure a suitable
angle and orientation for feeding projectiles from the hopper to
the canister. The canister may be secured to the cover in any
suitable manner, for example with the U-shaped (when viewed from
the front or rear of the device) member 78, which may be provided
with adjustable gripping members such as screw to engage the
canister securely. In this case, the blower expels air through an
opening in the top of the cover 74, and communicates with the
canister by a short pipe, allowing a simple and direct air supply
to the canister and improving the balance of the machine.
[0049] In the ball propulsion apparatus shown in FIG. 6 and FIG. 7,
the blower is outside of the canister. This is advantageous in that
it increases the effective volume of the canister. However,
providing the blower inside of the canister is possible, as is the
case of the apparatus in FIGS. 1 and 2.
[0050] While a detailed description of the present invention has
been provided above, the invention is not limited thereto, and
modifications thereto will be apparent. The invention is defined by
the following claims.
* * * * *