U.S. patent application number 13/177743 was filed with the patent office on 2012-01-12 for projectile launcher.
This patent application is currently assigned to TUBE PLASTICS LIMITED. Invention is credited to Christopher Martyn-Smith, Gary Smith, Ian Webb.
Application Number | 20120010050 13/177743 |
Document ID | / |
Family ID | 42712064 |
Filed Date | 2012-01-12 |
United States Patent
Application |
20120010050 |
Kind Code |
A1 |
Smith; Gary ; et
al. |
January 12, 2012 |
PROJECTILE LAUNCHER
Abstract
A projectile launcher for launching a projectile is provided.
The projectile launcher is arranged to be connected to a trampoline
having a frame and a jumping mat, the jumping mat connected to the
frame by resilient members, the projectile launcher including a
propulsion element adapted to provide a motive force to propel a
projectile and an energy extraction element arranged to be
connected to a trampoline and to extract energy from the action of
a user bouncing on the trampoline to provide power to the
propulsion element.
Inventors: |
Smith; Gary;
(Worcestershire, GB) ; Martyn-Smith; Christopher;
(Worcestershire, GB) ; Webb; Ian; (London,
GB) |
Assignee: |
TUBE PLASTICS LIMITED
Worcestershire
GB
|
Family ID: |
42712064 |
Appl. No.: |
13/177743 |
Filed: |
July 7, 2011 |
Current U.S.
Class: |
482/27 ; 124/16;
124/56 |
Current CPC
Class: |
A63B 2009/008 20130101;
A63B 69/407 20130101; A63B 69/409 20130101; A63B 71/022 20130101;
A63B 47/02 20130101; A63B 21/157 20130101; A63B 47/002 20130101;
A63B 5/11 20130101; A63B 5/00 20130101 |
Class at
Publication: |
482/27 ; 124/16;
124/56 |
International
Class: |
A63B 5/11 20060101
A63B005/11; F41B 11/00 20060101 F41B011/00; F41B 7/00 20060101
F41B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2010 |
GB |
GB 1011463.5 |
Claims
1. A projectile launcher for launching a projectile, the projectile
launcher arranged to be connected to a trampoline having a frame
and a jumping mat, the jumping mat connected to the frame by
resilient members, the projectile launcher including a propulsion
element adapted to provide a motive force to propel a projectile
and an energy extraction element arranged to be connected to a
trampoline and to extract energy from the action of a user bouncing
on the trampoline to provide power to the propulsion element.
2. A projectile launcher according to claim 1, in which the energy
extraction element is adapted to be connected to the jumping mat or
to one or more of the resilient members.
3. A projectile launcher according to claim 1, in which the energy
extraction element includes a cable, arranged to be connected at a
first end to the trampoline, and connected at a second end to a
ratchet mechanism, the cable arranged to be drawn by the trampoline
as a user jumps on the trampoline to actuate the ratchet
mechanism.
4. A projectile launcher according to claim 1, in which the energy
extraction element includes at least one lever element to alter the
ratio between the movement of the jumping mat as the user bounces
on the trampoline and the movement of the ratchet mechanism.
5. A projectile launcher according to claim 3, in which the
propulsion element includes a spring for providing the motive force
and the ratchet mechanism is used to withdraw the spring.
6. A projectile launcher according to claim 1, in which the energy
extraction element comprises a pump and the propulsion element
includes a pressure reservoir, wherein the pump is arranged to be
actuated by the reciprocating motion of the jumping apparatus as a
user jumps, and the pressure reservoir is arranged to be charged
with pressure by the pump.
7. A projectile launcher according to claim 1, in which the
projectile launcher is arranged to launch a projectile with each
bounce of the user on the jumping apparatus
8. A projectile launcher according to claim 1, in which the
propulsion element includes a trigger mechanism adapted to release
the energy stored in the propulsion element when a predetermined
force or pressure is reached or after a predetermined time interval
or after a predetermined amount of movement of the energy
extraction element, or after a predetermined number of bounces on
the trampoline.
9. A projectile launcher according to claim 1, in which the
projectile launcher is arranged to launch a projectile comprising
one of a ball, a rocket, a bubble, or a jet of fluid.
10. A trampoline in combination with a projectile launcher for
launching a projectile, the projectile launcher including a
propulsion element adapted to provide a motive force to propel a
projectile and an energy extraction element connected to the
trampoline and adapted to extract energy from the action of a user
bouncing on the trampoline to provide power to the propulsion
element.
11. A combination according to claim 10, in which the projectile
launcher includes a hopper for guiding projectiles into the
projectile launcher for propulsion by the propulsion element and
wherein the hopper may be adapted to store more than one projectile
and feed the projectiles into the projectile launcher one at a
time.
12. A combination according to claim 10, in which the trampoline is
at least partially surrounded by a screen assembly that at least
partially encloses a region above the jumping mat and the hopper is
accessible to receive projectiles through a projectile return
aperture in the screen assembly.
13. A combination according to claim 12, in which the projectile
return aperture is located beneath the projectile launcher and a
projectile lifting mechanism is connected between the projectile
return aperture and the hopper, the projectile lifting mechanism
arranged to lift the projectile to the hopper and optionally the
projectile lifting mechanism is powered by the energy extraction
element or a second energy extraction element.
14. A combination according to claim 10, in which the projectile
launcher comprises an aiming mechanism so that the user can direct
the projectiles to a particular location.
15. A kit of parts comprising a trampoline and a projectile
launcher as defined in claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. .sctn.119(a)
of British Patent Application No. 1011463.5 filed Jul. 7, 2010, the
entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a projectile launcher and, in
particular, a projectile launcher for attachment to a jumping
apparatus, such as a trampoline. It also relates to a jumping
apparatus in combination with the projectile launcher. It also
relates to a kit of parts for assembly into a jumping apparatus and
projectile launcher.
[0004] 2. Description of Related Art
[0005] Trampolines are a type of jumping apparatus that typically
comprise a flexible mat connected to a frame by one or more springs
or other resilient members such that the flexible mat is held above
the ground in tension. Energy stored in the springs when a user
jumps on the flexible mat can be used to propel them into the air.
Alternatively, the springs and flexible mat may be replaced with an
elastic mat, connected to the frame, which stretches and resiles to
propel the user into the air. A jumping pillow or inflatable
trampoline is further type of jumping apparatus that includes a
frame containing a flexible or elastic hollow body that is filled
with fluid, such as air. A user compresses the fluid or deforms the
body as they jump onto the apparatus to store energy, which can be
used to assist in propelling them into the air when they jump from
the apparatus. Thus, this jumping apparatus is also arranged to
store energy to propel a user into the air when the user jumps onto
the jumping apparatus enabling them to bounce.
BRIEF SUMMARY OF THE INVENTION
[0006] According to a first aspect of the invention, we provide a
projectile launcher for launching a projectile, the projectile
launcher including a propulsion element adapted to provide a motive
force to propel a projectile and an energy extraction element
arranged to be connected to a jumping apparatus and to extract
energy from the action of a user bouncing on the jumping apparatus
to provide power to the propulsion element.
[0007] This is advantageous as the projectile launcher can be used
with a jumping apparatus, such as a trampoline, to launch
projectiles toward the trampoline for the user of the trampoline to
catch, which is fun. Further, the projectile launcher is powered by
the user bouncing on the trampoline. Thus, the energy extraction
element advantageously takes a portion of the energy that would
have been stored in the jumping apparatus for propelling the user
and uses it to provide power to the propulsion element for use in
its propulsion of the projectile.
[0008] Preferably the projectile launcher is arranged to be
connected to a jumping apparatus comprising a trampoline having a
frame and a jumping mat, the jumping mat connected to the frame by
resilient members.
[0009] Preferably the energy extraction element is arranged to be
connected to the jumping mat. This is advantageous, as the jumping
mat moves relative to the frame as the resilient members stretch
and resile with each bounce of the user, which provides a
convenient point to extract energy from the trampoline.
Alternatively the energy extraction element may be adapted to be
connected to one or more of the resilient members.
[0010] Preferably the energy extraction element includes a cable,
arranged to be connected at a first end to the jumping apparatus,
and connected at a second end to a ratchet mechanism, the cable
arranged to be drawn by the trampoline as a user jumps on the
jumping apparatus to actuate the ratchet mechanism.
[0011] Preferably the energy extraction element includes at least
one lever element to alter the ratio between the movement of the
jumping mat as the user bounces on the trampoline and the movement
of the ratchet mechanism. This is advantageous as the lever element
can be easily adjusted to tailor the typical displacement of the
mat experienced by the trampoline to the operation energy
extraction element. Thus, the lever element can be used to adjust
the projectile launcher for use with different trampolines,
different resilient element strengths and different user weights,
for example.
[0012] Preferably the propulsion element includes a spring for
providing the motive force and the ratchet mechanism is used to
withdraw the spring. Thus, the energy from the energy extraction
element powers the withdrawal of the spring so that the projectile
can be launched.
[0013] Alternatively the energy extraction element may comprise a
pump and the propulsion element may include a pressure reservoir,
wherein the pump is arranged to be actuated by the reciprocating
motion of the jumping apparatus as a user jumps, and the pressure
reservoir is arranged to be charged with pressure by the pump. This
is advantageous as the air pressure can be used to propel a
projectile.
[0014] The projectile launcher may be arranged to launch a
projectile with each bounce of the user on the jumping apparatus.
Alternatively, the propulsion element may be arranged to store the
energy from the energy extraction element and release it when a
predetermined threshold is reached. This is advantageous, as the
propulsion element may include a trigger mechanism adapted to
release the energy stored in the propulsion element when a
predetermined force or pressure is reached.
[0015] Preferably the projectile launcher is constructed and
arranged to launch a projectile comprising one of a ball, a rocket,
a bubble, or a jet of fluid.
[0016] According to a second aspect of the invention, we provide a
jumping apparatus in combination with a projectile launcher for
launching a projectile, the projectile launcher including a
propulsion element adapted to provide a motive force to propel a
projectile and an energy extraction element connected to the
jumping apparatus and adapted to extract energy from the action of
a user bouncing on the jumping apparatus to provide power to the
propulsion element.
[0017] This is advantageous as the combination of the projectile
launcher and the jumping apparatus provides entertainment that
allows a user to combine the game of jumping with the game of
catching.
[0018] Preferably the jumping apparatus includes a jumping mat and
a support that extends above the jumping mat for supporting the
projectile launcher.
[0019] Preferably the projectile launcher includes a hopper for
guiding projectiles into the projectile launcher for propulsion by
the propulsion element. Preferably the hopper is adapted to store
more than one projectile and feed the projectiles into the
projectile launcher one at a time.
[0020] Preferably the jumping apparatus is at least partially
surrounded by a screen assembly that at least partially encloses a
region above the jumping mat. The screen assembly is advantageous
as it may act to prevent a user bouncing off the jumping apparatus,
which could lead to injury. Preferably the support forms part of
the screen assembly.
[0021] Preferably the projectile launcher includes a hopper for
guiding projectiles into the projectile launcher for propulsion by
the propulsion element. Preferably the hopper is accessible to
receive projectiles through a projectile return aperture in the
screen assembly. Preferably the projectile return aperture is
located at a position in the screen higher than the projectile
launcher. Thus, the projectiles will be guided by the hopper under
the influence of gravity.
[0022] The projectile return aperture may be located beneath the
projectile launcher and a projectile lifting mechanism may be
connected between the projectile return aperture and the hopper,
the projectile lifting mechanism arranged to lift the projectile to
the hopper. The projectile lifting mechanism may be powered by the
energy extraction element or a second energy extraction element.
This is advantageous as it allows smaller children to return the
projectile to a point that is easily reached, rather than making
them struggle to return the projectile to a point which may be far
above them.
[0023] The projectile launcher may be arranged to launch
projectiles within the bounds of the screen assembly.
Alternatively, the projectile launcher may comprise an aiming
mechanism so that the user can direct the projectiles to a
particular location. This is advantageous as the particular
location may be into a further jumping apparatus having a
projectile launcher.
[0024] It will be appreciated that the optional features described
above in relation to the first aspect of the invention apply
equally to the second aspect of the invention.
[0025] According to a third aspect of the invention we provide a
kit of parts comprising a jumping apparatus and a projectile
launcher as defined in the first aspect of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0026] There now follows by way of example only a detailed
description of the present invention with reference to the
accompanying drawings in which;
[0027] FIG. 1 shows a first view of an embodiment of a jumping
apparatus in combination with a projectile launcher;
[0028] FIG. 2 shows a second view of the embodiment of FIG. 1;
[0029] FIG. 3 shows a cut away view of the embodiment of the
projectile launcher shown in FIGS. 1 and 2;
[0030] FIG. 4 shows a side view of an embodiment of the projectile
launcher;
[0031] FIG. 5 shows a perspective view of the projectile launcher
shown in FIG. 4 with a further part removed;
[0032] FIG. 6 shows a further perspective view of the other side of
the projectile launcher shown in FIG. 4 with further parts removed
for clarity;
[0033] FIG. 7 shows the connection between an energy extraction
element and a trampoline;
[0034] FIG. 8 shows a diagrammatic view of a second embodiment of
the projectile launcher; and
[0035] FIGS. 9a and 9b show a second embodiment of the energy
extraction element and its connection to a trampoline with FIG. 9b
showing a magnified portion of FIG. 9a.
DETAILED DESCRIPTION OF THE INVENTION
[0036] A trampoline 1 in combination with a projectile launcher 2
is shown in FIG. 1. The projectile launcher 2 is adapted to launch
a projectile 3 and is powered by a user 4 bouncing on the
trampoline. The user 4 may choose to catch or collect the
projectile 2 while they are bouncing.
[0037] The trampoline 1 comprises a frame 5 and a jumping mat 6,
which may be of materials such as polyethylene of polypropylene.
The jumping mat 6 is connected to the frame 5 by one or more
resilient members 9 (shown in FIG. 7), which, in this embodiment,
comprise a plurality of coil springs. It will be understood that
other resilient members could be used, for example spring loaded
rods or elasticised material. The coil springs hold the jumping mat
6 in tension within the frame 5.
[0038] The frame 5 comprises a plurality of legs 7 that support the
jumping mat 6 above the ground. The trampoline 1 includes a screen
assembly 8 that extends from around the perimeter of the jumping
mat 6 upwardly therefrom. The screen assembly 8 includes a safety
screen 10 which acts to prevent the user 4 bouncing off the
trampoline and potentially injuring themselves. The safety screen
10 includes a door 11 to allow the user 4 to access to and from the
jumping mat 6. The safety screen 10 also includes a projectile
return aperture 12 which leads to a hopper 13. The hopper 13 is
arranged above the projectile launcher 2 and receives projectiles
through the projectile return aperture 12. The hopper 13 guides the
projectiles into the projectile launcher 2 for launching. In this
embodiment, the hopper 13 is arranged to store a plurality of
projectiles for sequential feeding into the projectile launcher 2.
Thus, the hopper 13 comprises a wide mouth 14 adjacent the
projectile return aperture 12, which narrows to a size
corresponding to the projectile 3 so that only one projectile can
enter the projectile launcher at any one time. The safety screen
also includes a launch aperture 19 through which the projectile
launcher 2 propels the projectiles over the jumping mat 6.
[0039] The projectile launcher 2 is supported above the jumping mat
6 by a launcher support 15. The launcher support 15 also houses
part of an energy extraction element, as will be described
below.
[0040] The projectile launcher 2 comprises a propulsion element 20
for launching the projectile 3 and an energy extraction element 21
for powering the propulsion element 20. The propulsion element 20
and part of the energy extraction element 21 are surrounded by a
housing 22 (shown in FIGS. 1 and 2, but omitted from subsequent
Figures for clarity). The housing 22 also includes a tubular barrel
portion 23, which guides the projectile 3 out of the projectile
launcher 2 when the propulsion element 20 propels the
projectile.
[0041] The propulsion element 20 comprises a coil spring 24, which
acts on a launching ram 25. The launching ram 25 is mounted at one
end of a launching rod 26. The launching ram 25 is arranged to
contact the projectile to propel it from the projectile launcher 2
when spring 24 releases its energy. The launching rod 26 is
slidably received within a launcher support 27. The spring 24
extends between the ram 25 and the launcher support 27, biasing
them apart. Thus, withdrawal of the launching rod 26 into launcher
support 27 will cause the launching ram 25 to compress spring 24
against the launcher support 27.
[0042] The energy extraction element 21 comprises a transfer cable
28, a ratchet arm 30 and a withdrawal wheel 31. The withdrawal
wheel 31 includes a ratchet gear 32 fixedly secured thereto, which
is acted on by ratchet arm 30. The transfer cable 28 is connected
to the trampoline 1 at one end and to the ratchet arm 30 at its
other end. The ratchet arm 30 and withdrawal wheel 31 are rotatably
connected to an axle 33 and can rotate independently of one
another. The axle 33 extends between opposed sides of the launcher
support 27.
[0043] The ratchet arm 30 can pivot about axle 33 and includes a
pawl 34 that acts on the ratchet gear 32. The pawl 34 is rotatably
secured to the ratchet arm 30 by an axle 35. The pawl 34 is biased
towards engagement with the ratchet gear 32 by a spring (not
visible). The ratchet arm 30 is adapted to move between a first
position, where it abuts the launcher support 27 (as shown in FIG.
4) and a second position when it is rotated in the direction of
arrow 29. The ratchet arm 30 is biased to the first position by a
return spring 38.
[0044] The withdrawal wheel 31 includes withdrawal pegs 36a, 36b
and 36c (shown best in FIG. 6). The withdrawal pegs 36a, 36b, 36c
are arranged to contact a withdrawal plate 37. The withdrawal plate
37 extends from the launching rod 26 toward the pegs 36a, 36b, 36c.
The pegs 36a, 36b, 36c and withdrawal plate are arranged such that
rotation of the withdrawal wheel 31 causes each of the pegs 36a,
36b, 36c to bear against withdrawal plate 37 over a portion of
their circular path. The withdrawal pegs thus withdraw the
launching rod 26 against the force of spring 24 as the withdrawal
wheel 31 rotates. After a predetermined amount of rotation, the
pegs will move out of engagement with the withdrawal plate 37,
allowing the launching rod 26 and launching ram 25 to shoot forward
under the influence of the spring 24.
[0045] The ratchet gear 32 is also acted on by a second pawl 40.
The second pawl 40 pivots about an axle 41 that is secured to the
launcher support 27.
[0046] FIG. 7 shows the connection between the transfer cable 28
and the trampoline 1. The transfer cable 28 is secured to the
jumping mat 6 at the same point as one of the resilient members 9.
The transfer cable 28 extends through the resilient member 9 and
under a guide member 42. The guide member 42 is secured to the
frame of the trampoline. Thus, when a user 4 jumps on the
trampoline jumping mat 6, the resilient members 9 will stretch
increasing the distance between the jumping mat 6 and the guide
member 42. This will apply a force to the transfer cable 28, which
will act to move the ratchet 30 from its first position towards its
second position. It will be appreciated that the more force the
user applies to the jumping mat 6, the further the angular
separation between the first position and the second position. The
transfer cable 28 may include an extendable portion (not shown)
which increases the length of the cable 28 should a potentially
damaging force be placed on the cable. This will prevent damage to
the projectile launcher 2. It will be appreciated that the transfer
cable 28 could be attached to one or more of the resilient members
9. Further, it may be secured to a belt that passes under the
jumping mat 6 and is secured to an opposed side of the frame of the
trampoline. Thus, the belt will be moved by the deformation of the
jumping mat 6 and will transfer the displacement to the transfer
cable 28.
[0047] In use, the projectile launcher 2 will typically have a
projectile, such as a ball 3, loaded within it on launching plate
50, adjacent the launching ram 25. As the user bounces on the
jumping mat 6, the transfer cable 28 is drawn and released with
each bounce and is kept taut by the return spring 38 acting on
ratchet arm 30. This reciprocating motion of the transfer cable 28
repeatedly moves the ratchet arm between its first and second
positions. The pawl 34 of the ratchet arm 30 will act to rotate the
ratchet gear 32 when it moves from its first position to its second
position. When the ratchet arm 30 moves back to its first position,
the pawl 34 rides over the teeth of the ratchet gear 32. The second
pawl 40 acts to prevent the ratchet gear 32 rotating with the
ratchet arm 30 when it returns from the second position to the
first position. Thus, the ratchet arm 30 converts the reciprocating
motion of the transfer cable 28 into rotary motion of the
withdrawal wheel 31 in a single direction.
[0048] With reference to FIG. 6, rotation of the ratchet gear 32
and therefore also the withdrawal wheel 31 advances pegs 36a, 36b,
36c in the direction of arrow 51. Each peg 36a, 36b, 36c will, in
turn, engage the withdrawal plate 37 as the withdrawal wheel 31 is
rotated in steps. The withdrawal plate 37 extends between the pegs
36a, 36b, 36c such that rotation of the withdrawal wheel 31 will
withdraw the launching rod 26. With further rotation of the
withdrawal wheel 31, the peg in contact with the withdrawal plate
37 will move towards the free end 52 of the plate 37. The peg will
then move out of engagement with the withdrawal plate 37. On doing
so the launching rod 26 is no longer prevented from shooting
forward under the force of spring 24 in the direction of arrow 52
to contact the projectile 3 and launch it from the projectile
launcher 2. The energy stored in spring 24 is used to launch the
projectile. Thus, the length of the withdrawal plate 37 and its
interaction with the pegs 36a, 36b, 36c act as a trigger mechanism
which determines the amount of withdrawal of the launching rod 26
before it is allowed to launch the projectile 3.
[0049] FIG. 8 shows a second embodiment of the projectile launcher
2. The propulsion element 20 comprises a pressure storage vessel 81
and the energy extraction element 21 comprises a pump
mechanism.
[0050] The propulsion element 20 uses the air pressure stored in
the pressure vessel to propel the projectile 3 from a barrel 80.
The propulsion element 20 releases the pressure from the pressure
vessel 81 when a trigger mechanism, comprising a pressure release
valve 82, reaches a predetermined pressure.
[0051] The pump mechanism 21 uses the reciprocating motion of the
transfer cable 28 to drive a lever 83 between a first position (as
shown in FIG. 8) and a second position. The return spring 38 biases
the lever 83 to the first position and keeps the transfer cable 28
taut. Movement of the lever 38 drives a piston 84 within a bore 85.
The piston 84 includes a one-way valve (not shown) to draw air into
the bore 85. As the piston moves toward the pressure storage vessel
81 it drives the drawn in air into the vessel 81. A second one-way
valve 86 maintains the pressure in the pressure storage vessel 81
when the piston 84 is withdrawn. In this embodiment the piston 84,
bore 85 and pressure vessel 81 are shown as being housed in a
single hollow body, although it will be appreciated that the piston
84 and bore 85 could be separate from the pressure vessel 81.
[0052] In use, each bounce of the user on the jumping mat 6 acts
through the cable 28 and the lever 83 to pump air into the pressure
storage vessel 81. When a predetermined pressure is reached within
the vessel 81, the pressure release valve 82 opens, which allows
the pressurized air to vent through a conduit 87 into a base 88 of
the barrel 80 behind a projectile 3. The escaping pressurized air
provides the motive force to propel the projectile 3 along and out
of the barrel 80.
[0053] This embodiment may also include a hopper (not shown in FIG.
8) for feeding projectiles into the projectile launcher 2. The
barrel 80 includes a lip 92 to receive projectiles 3 from the
hopper. The hopper dispenses the projectile in the direction of
arrow 91 on to the lip 92. The projectile 3 can then roll into the
barrel 80 for subsequent launching.
[0054] In a modification (not shown) the pump mechanism may be
connected directly to the jumping mat 6 and frame 5 instead of via
the transfer cable 38. Thus, movement of the jumping mat 6 relative
to the frame 5 withdraws and drives the piston 84 within the bore
85. The air pressure from the pump is transported by a conduit to
the pressure vessel 81.
[0055] In a modification (not shown) the projectile launcher 2 of
FIG. 8 may be adapted to launch bubbles rather than balls. Thus,
the barrel 80 will be replaced with a bubble generator and bubble
liquid reservoir. The bubble liquid reservoir contains a liquid,
such as soap solution, from which the bubbles are formed. The air
supply conduit 87 is connected to the bubble generator to supply a
stream of air for generating the bubbles. The pressure release
valve 82 will be set to a lower level for generating bubbles, as
less pressure will typically be required for generating bubbles
than propelling a ball from a barrel.
[0056] The projectile launcher 2 may include an aiming mechanism so
that the user can set where the projectile launcher 2 launches the
projectiles. The aiming mechanism may comprise an adjustable
bracket between the launcher support 15 and the projectile launcher
2. The adjustable bracket may include means for ensuring that the
projectile launcher 2 is aligned with the launch aperture 19,
regardless of the position of the aiming mechanism.
[0057] The portion of the safety screen 10 and screen assembly 8
including the projectile return aperture 12 may be separable from
the remainder of the screen assembly and may be adapted to retrofit
to an existing trampoline with or without a safety screen. Thus,
the projectile launcher 2 may form part of a kit of parts for
retrofitting to a trampoline, the kit also including the projectile
launcher support 15 and hopper 13. The launcher support 15 may
include a connector for connecting it to a frame of a trampoline.
The kit of parts may include the screen assembly with projectile
return aperture 12.
[0058] FIGS. 9a and 9b show part of a further embodiment of an
energy extraction element 21. This embodiment utilises a lever
element comprising a lever 100 for magnifying the displacement of
the jumping mat for operating the energy extraction element.
Further, the lever element 100 can be adjusted by moving the
fulcrum to compensate for different trampolines, the resilient
strength of the resilient members or the weight of a user. In this
embodiment, the lever 100 is connected to the jumping mat 6 at a
first end 101. An opposed end 102 of the lever 100 is connected to
a transfer rod 103. The lever 100 is mounted to a pivot point 105
on a guide frame 104 and the guide frame 104 connects to the
trampoline frame 5. The guide frame 104 includes a clamp 106 to
connect it to the poles that form the frame 5. The transfer rod 103
connects the lever 100 to a further lever 107 at first end 108,
which is located with the remainder of the energy extraction
element 21. The further lever 107 is connected to the guide frame
104 at a fulcrum 110. The further lever 107 has a second end 111,
opposite the first end 108, which engages a ratchet mechanism in
order to withdraw the propulsion element 20. The second end
includes a slot 109 that engages with a spigot on an index gear 112
to effect its rotation on movement of the further lever 107. The
ratchet mechanism comprises the index gear 112 which engages a
spring clutch 114 through a set of inclined teeth 118. The clutch
includes a series of grooves 119 in its circumferential surface
that engage with a ratchet 115. The index gear 112 drives a firing
wheel 113 through the clutch 114. The firing wheel 113 withdraws a
toothed rod 115 which forms part of the propulsion element. The
firing wheel 113 has a toothed portion 116 and a non-toothed
portion 117, wherein the propulsion element is released when the
non-toothed portion 117 aligns with toothed rod 115.
[0059] In use, each bounce of the user deforms the mat 6 and draws
the first end 101 of lever 100 downward. Accordingly, the opposed
end 102 is moved upwards, which pushes the transfer rod 103
upwards. The transfer rod 103 then acts on the first end 108 of the
further lever 107 to move it upwards. The second end 111 engages
the spigot of the index gear 112 which is rotated by the downward
movement of the second end 111. The index wheel 112 incrementally
rotates the firing wheel 113 through the clutch 114. As the
bouncing mat returns to its original position the second end 111 of
the further lever 107 will rise and the set of inclined teeth
between the index gear 112 and the spring clutch 114 and the
ratchet 115 ensure the mechanism "charges" the propulsion element.
The firing wheel 113 and propulsion element are arranged such that
the un-toothed portion 117 aligns with the toothed rod 115 when a
coil spring (not shown) of the propulsion element is withdrawn.
Thus, the firing wheel 113 and toothed rod 115 will be disengaged
to allow the energy stored in the coil spring to propel a
projectile, as discussed in previous embodiments.
[0060] In a further embodiment, the jumping apparatus comprises a
jumping pillow. The energy extraction element is thus modified to
extract energy from the jumping pillow. A typical jumping pillow
comprises a frame that houses a resiliently compressible hollow
body, which is filled with air. The energy extraction element is
substantially similar to that shown in the previous embodiments and
includes a transfer cable 28. The transfer cable is connected to a
pressure plate mechanism, which is mounted between the frame and
the hollow body. The pressure plate mechanism includes a first
plate element and a second plate element biased apart by a plate
spring. The transfer cable is secured between the first and second
plate elements. When a user 4 bounces on the hollow body to
compress it, the first plate element and second plate element are
pressed together against the force of the plate spring. This
movement releases tension in the transfer cable 28 and any slack is
taken up by return spring 38. When the hollow body resiles, the
first plate element and second plate element separate under the
force of the plate spring. This separation of the first plate
element and second plate element draws the transfer cable.
Accordingly, without the weight of a user on the jumping pillow,
the pivot arm 30 adopts its second position. When a user pushes
downward to compress the jumping pillow, the pivot arm 30 moves to
the first position under the force of return spring 38. When a user
jumps from the jumping pillow into the air, the plate spring moves
the pivot arm to the second position thereby rotating the
withdrawal wheel 31. It will be appreciated that other forms of
jumping apparatus could be used and the energy extraction element
is arranged to extract energy from the jumping apparatus that would
previously have been used to propel the user who bounces on the
jumping apparatus.
[0061] Although the present invention has been described as
extracting energy from the trampoline when a user bounces on the
trampoline, it may be arranged to extract energy when the resilient
elements of the trampoline recoil from their extended position.
Also, the energy extraction element may store the energy for
propelling the ball in any appropriate manner, such as potential
energy in a spring or pressure vessel or as electricity generated
by a generation means powered by the user bouncing on the
trampoline. Further, the energy extraction element may connect to
the trampoline in any appropriate manner in order to use the action
of user jumping or bouncing to actuate the projectile launcher.
* * * * *