TECHNICAL FIELD

[0001] The present invention relates to a system for launching a model rocket. More particularly, the present invention relates to a launch system for a model rocket constructed of soft drink or soda bottles. The launch system makes use of water and / or compressed air to propel the model rockets. The present invention may be used as an educational tool and / or for fun.

BACKGROUND ART

[0002] Launch pads and systems for launching model rockets are known in the art and may be used for fun and / or educational purposes.

[0003] One example of a known launch pad is sold commercially under the name “Aquapod”. The Aquapod has a rocket release based on a pull cord lever that causes difficulty when launching because upon action of the pull cord, the entire system can undesirably move. This necessitates securing the Aquapod unit to the ground using, for example, tent pegs to prevent it from moving when the release cord is pulled. However, this makes for extreme difficulty when attempting to launch off any hard surface where anchor points are limited. The synthetic string used for the pull cord also tends to break after repeated launches. In turn, this can result in users physically handling the system to actuate it by hand thereby comprising safety. The Aquapod is also prone to leaking water from the rocket into the plumbing which leads to inconsistent results. The Aquapod is only capable of one launch angle. Further, the Aquapod tends not to hold pressure reliably after repeated use leading inconsistent results.

[0004] Another example of a known launch pad is sold commercially under the name “Liquifly”. The Liquifly has a hollow rubber bung that fits in to the opening of a rocket bottle which is blown out of the opening when it can no longer withstand the internal pressure of the bottle, similar to a cork escaping a champagne bottle. However, this also means that the user is unable to control when the rocket is released. Like the Aquapod, the Liquifly is only capable of launching a rocket at one angle. Pressure is also not held reliably as this depends on the condition of the rubber bung and the bottle as they wear with time and repeated use.

[0005] There is thus a need for improved launch systems and pads for model rockets.

[0006] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0007] The present invention is directed to system for launching a model rocket which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

[0008] With the foregoing in view, the present invention in one form, resides broadly in a system for launching a bottle comprising:

a launch pad configured for supporting the bottle prior to launch;

a trigger release handle configured for controlled launch of the bottle at a predetermined time; and

an actuation cable operatively connecting the trigger release handle to the launch pad; wherein in use the system is pressurised with air and the trigger release handle is activated to actuate the cable and launch the bottle from the launch pad.

[0009] The present invention in another form resides broadly in a network comprising a plurality of launch systems as disclosed above, and an air source connected to the plurality of launch systems.

[0010] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[001 1] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0012] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[0013] Figure 1 is a perspective view of a launch system according to an embodiment of the invention. [0014] Figure 2 is a partial cross-sectional side view of the second support leg in the system in figure 1. The view is taken from the side opposing the launch angle indicator.

[0015] Figure 3 is a cross-sectional perspective view of the trigger release handle in the system in figure 1.

[0016] Figure 4 is an exploded front view showing the components of the spout support member in the system in figure 1.

[0017] Figure 5 is a partial cross-sectional side view of the launch pad in the system in figure 1 prior to fitting with a bottle.

[0018] Figure 6 is a partial cross-sectional side view of the launch pad in the system in figure 1 in a bottle-locked, pre-launch configuration.

[0019] Figure 7 is a partial cross-sectional side view of the launch pad in the system in figure 1 in a bottle-released, post-launch configuration.

[0020] Figure 8 is a perspective of the launch system in figure 1 during use on an indoor (i.e. interior) surface.

[0021] Figure 9 is a side view of a plurality of launch systems in figure 1 during use on an outdoor (i.e. exterior) surface and connected to a common air source.

[0022] Figure 10 is a side view of the second support leg in the launch system according to another embodiment of the invention.

[0023] Figure 1 1 is a is a cross-sectional view of the trigger release handle in the launch system according to another embodiment of the invention.

[0024] Figure 12 is a partial cross-sectional side view of the launch pad in the launch system prior to fitting with a bottle according to an embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

[0025] The features of a launch system 10 as depicted in the accompanying figures and their respective reference numerals are listed in the table below.

[0026] Figures 1 to 7 illustrate a launch system 10 for launching a model rocket exemplified as a soft drink bottle 16. Figures 10 to 12 depict alternative embodiments of certain features illustrated in figures 1 to 7 that may also be used in the launch system 10. System 10 comprises a launch pad 12, a trigger release handle 14, and an actuation cable 36 operatively connecting the handle 14 to the pad 12.

[0027] The launch pad 12 comprises a first support leg 18, a second support leg 20 opposing the first support leg 18, and a centrally located support structure 24 mounted between the first and second support legs 18 and 20.

[0028] The support structure 24 supports the inverted bottle 16, is adjustable by rotation about a longitudinal axis that extends between and is perpendicular to the first and second legs 18 and 20, and provides a passage for compressed air to the interior of the bottle 16 in use as will be described below. [0029] The support structure 24 may be manufactured as one piece by injection moulding, if desired.

[0030] However, in the illustrated embodiment, the support structure 24 has a generally horizontally elongated spout support member 56 mounted between the first and second legs 18 and 20. The spout support member 56 is comprised of a connector 65, two connecting tubes 59, and two end caps 57 all made of PVC (polyvinyl chloride) as shown in figure 4. The hollow connector 65 is integrally formed with four outlets most of which are arranged in an L- or T- shape relative to one another. Connecting tubes 59 are hollow but could be solid if desired.

[0031] One end of each tube 59 is friction fitted to an opposing outlet on connector 65. In another embodiment, one end of each tube 59 is glued into an opposing outlet on connector 65.

In yet another embodiment, one or more screws such as self-tapping screws are inserted through and into the connector 65 and the tube 59 to strengthen the connection between connector 65 and tube 59.

[0032] The other ends of tubes 59 pass through a leg bushing 21 then a hole in the supporting legs 18, 20. The leg bushing 21 prevents the supporting leg 18 from moving or creeping slowly towards the centre of the launch pad 12 in use. System 10 has two leg bushings 21 , one for each leg 18 and 20, although only one bushing 21 is visible in figure 1. The leg bushing 21 is secured to the end of the connecting tube 59 that passes through the supporting legs 18 or 20. In an alternative embodiment, the leg bushing 21 has a tube-like shape that extends along the length of the connecting tube 59 between a supporting leg 18 or 20 and connector 65 and is able to rotate freely around the tube 59. This eliminates the need for leg bushing 21 to be secured to the tube 59. The tube 59 that passes through supporting leg 20 also passes through bush nut 23 that provides spacing between the angle indicator 22 and the angle markings displayed or embossed on leg 20. This stops the angle indicator 22 from scraping against the angle markings in use thereby preventing wear of these parts. The angle indicator 22 has a recess (not shown) through which the connecting tube 59 also passes. The recess prevents undesired movement between the tube 59 and the angle indicator 22. Therefore, as tube 59 is rotated about its longitudinal axis, the angle indicator 22 also moves simultaneously i.e. independent movement is prevented. This ensures the user always reads the correct angle. End caps 57 are then friction fitted over the ends of connecting tubes 59 that have passed through the supporting legs 18, 20. As an alternative to the arrangement shown in figure 4, the spout support member 56 may also be manufactured as one piece should the entire structure 24 not be integrally formed. [0033] Spout support member 56, and more particularly an outlet of connector 65 as illustrated, is connected to an air inlet 52 via an adapter 54. An example of a suitable air inlet 52 is a standard Nitto fitting, a Schrader valve (standard car tyre type valve), or a Jopla air compressor fitting. Air inlet 52 is connected to an air source (not shown), e.g. compressed air, via air hose 26.

[0034] As shown in figure 2, a friction plate 38 lies against the underside of the connecting tube 59 of the spout support member 56 within a recess in the second support leg 20. The friction plate 38 has the shape of an arc and thus may also be known as an arc plate although the friction plate may be of any suitable shape. For example, the friction plate 38 may have the shape of an arc with a square flat base as showin in figure 10. Should plate 38 wear with time and repeated use it may be easily replaced. A friction adjustment nut 40 is operatively associated with the plate 38. The nut 40 extends away from the plate 38 and the underside of the second support leg 20 towards the surface upon which the launch pad 12 rests. This is best observed in figure 2. In use, the nut 40 is turned to anti-clockwise to loosen the pressure of the plate 38 against tube 59 which allows the spout support member 56 to be rotated about its longitudinal axis extending between the first and second legs 18 and 20. When the desired launch angle is attained, nut 40 is turned clockwise to tighten the plate 38 against tube 59 which prevents rotation of member 56, variation of the launch angle, and the launch pad 12 from falling over in use. This allows for variation and control of the launch angle relative to the surface on which the system 10 stands. The launch pad 12 may have only one plate 38 and one nut 40 on either first or second legs 18 or 20.

Alternatively, the launch pad 12 may have two plates 38 and two nuts 40, one on each of the first and second legs 18 and 20 as shown in figure 1. Although friction plate 38 may be 3D printed, plate 38 is preferably machined from aluminium, or a suitable plastic such as polycarbonate or acrylic, to increase its life span. The nut 40 may be a melt-in copper nut insert.

[0035] The support structure 24 also has a generally elongated pressure spout 58 arranged in a perpendicular orientation relative to the spout support member 56. The lower end of the pressure spout 58 is connected to an outlet of the connector 65 and secured in place with a suitable adhesive such as cyanoacrylate (CA) to prevent leaking while the opposing end has a pressure spout outlet 68 that is in contact with, and directly supports, the bottle 16. In some embodiments, one or more screws such as self-tapping screws are inserted into and through the connector 65 and the lower end of the pressure spout 58 to strengthen the connection between connector 65 and pressure spout 58. First, second, and third sealing O-rings 70, 71, and 72 are located on the pressure spout outlet 68 for preventing escape of compressed air from system 10.

Preferably, O-rings 70, 71, and 72 are two millimetre industrial standard O-rings. An air channel 60 passes through the interior of pressure spout 58 and is configured for passage of air from the air source and spout support member 56 to the bottle 16. Mounted on the exterior of the pressure spout 58 are a cable guide 28, first and second restraint arms 64 and 66, a resilient band 62 around the lower ends of the restraint arms 64 and 66, a bracket 61, and a release collar 30. The cable guide 28 and the bracket 61 extend around the circumference of the pressure spout 58. A lower portion of each restraint arm 64 and 66 is fastened to bracket 61 using a screw or pin, for example. The bracket 61 also functions as a seat for the release collar 30 prior to the system 10 being fitted with a bottle and post-launch of the bottle as shown in figures 5 and 7 respectively. The band 62, arms 64, 66, and release collar 30 will be described further below in the use of system 10. In an alternative embodiment, there is no cable guide 28 mounted on the pressure spout 58. In this embodiment, the bracket 61 includes a small cup (not shown) that receives the sheath 37 of actuation cable 36. This results in a more positive connection and negates the need for the cable guide 28.

[0036] Pressure spout 58 may be 3D printed from PLA (polylactic acid) with a two part epoxy coating to create a pressure seal. Alternatively, the pressure spout 58 may be 3D printed from ABS (acrylonitrile butadiene styrene) followed by an acetone vapour treatment to seal the porous plastic. In another alternative, the pressure spout 58 is CNC (computer numerical control) machined from a PVC (polyvinyl chloride) rod. In yet another alternative, the pressure spout 58 is CNC machined from Acetal plastic rod. This results in an absolute pressure seal. The other parts of the launch system 10, such as the supporting legs 18 and 20, and trigger release handle 14, preferably also have a two part epoxy coating applied after being 3D printed to provide increased rigidity and water proofness. The other parts of the launch system 10, such as the trigger release handle 14, may be 3D printed from PLA (polylactic acid). In another embodiment, one or both supporting legs 18 and 20 are produced by a CNC router from a 12 mm thick Acrylic sheet. In another embodiment illustrated in figure 10, each supporting leg 18 and 20 has a recess 92 for receiving a face plate 91. The face plate 91 is 3D printed and is thinner than the support legs 18 and 20. The face plate 91 is secured to the outwardly facing or launch angle indicator 22 side of each support leg 18 and 20. The face plate 91 displays the launch angle markings thereby functioning as a protractor. The angle markings are also 3D printed. Inclusion of the face plate 91 allows for an increased rate of manufacture, is quicker to produce, and results in stronger support legs 18 and 20. When the face plate 91 is present in the launch pad 12, there is no need to include the bush nut 23 as in essence the bush nut 23 is integrated into the face plate 91.

[0037] In another alternative, the components of the launch pad 12 are injection moulded from a suitable material such as plastic, preferably ABS. An advantage of manufacturing the system components by injection moulding is that the components are not porous and thus no epoxy coating need be applied.

[0038] The second support leg 20 has a launch angle indicator 22 that is operatively associated with the spout support member 56. As the spout support member 56 of structure 24 is rotated, the pressure spout 58, bottle 16 (if fitted), and indicator 22 are also rotated. The indicator 22 lines up with the longitudinal axes of the pressure spout 58 and bottle 16 when the launch pad 12 is viewed from the side, as well as angle markings provided on the second support leg 20 which are easily read by a user. Angle markings in 5 and 10 degree increments are shown in figure 1 in a similar manner to a protractor displaying angle markings. Rotation is achieved by a user gripping the support structure 24, preferably connector 65, with one or two hands then rotating the support structure 24 about the longitudinal axis of spout support member 56.

[0039] In another embodiment, the support structure 24 may be internally sealed at the junction of the connecting tubes 59 and the 4-way connector 65, with a male fitting end cap (not shown) inserted into the opposing outlets of the connector 65. Alternatively, the pressure seal may be achieved by using solid tubes instead of hollow tubes 59. This allows for easy servicing of the friction nut system 38 and 40 in the first and second legs 18 and 20 without compromising the integrity of the pressure inside structure 24 as the pressure is held within air hose 26, air inlet 52, connector 65, pressure spout 58, and bottle 16.

[0040] In another embodiment, a male fitting end plug (not shown) is inserted and glued into the end of each connecting tube 59 that is adjacent to the connector 65 as shown in figure 4. The male fitting end plug is 3D printed. After insertion of the male fitting end plug, epoxy is poured into the opposing open end of the connecting tube 59 and allowed to cure to ensure an absolute seal at the end of the tube 59 having the male fitting end plug that is adjacent to the connector 65. The male fitting end plug in conjunction with the epoxy seals each connecting tube 59 meaning the interior of each tube 59 is not under pressure during use of system 10. In turn this allows end caps 57 and / or launch angle indicators 22 to be screwed into the opposing ends of each tube 59 without loss of pressure as will be described below. After the epoxy has cured the connecting tube 59 is glued into the connector 65. The glue joint is then further reinforced by the insertion of a screw, such as a self tapping screw, penetrating both the connector 65 and the connecting tube 59.

[0041] Preferably, the launch pad 12 is highly symmetrical with a plane of symmetry passing vertically through bottle 16 (when fitted), pressure spout 58, and connector 65. This symmetry is most evident from figures 4 and 9. The launch pad 12 preferably has two launch angle indicators 22, two face plates 91, and two male fitting end plugs inserted into the end of each connecting tube 59. The high degree of symmetry simplies manufacture of the system 10 and allows a user to read the angle markings from either end of launch pad 12.

[0042] The trigger release handle 14 has a trigger 32 and a grip 34 adapted for gripping by a user’s hand as shown in figure 1. Grip 34 is comprised of two grip halves held together by one or more through bolts. One grip half is shown in figure 3. When the complementary grip halves are joined together they form a hollow interior space for housing internal components of the handle 14. A grip half according to another embodiment is shown in figure 11. An actuation cable 36 extends from the handle 14, through the cable guide 28 (if present) and bracket 61, to the release collar 30 on launch pad 12. The actuation cable 36 comprises a stainless steel cable 35 surrounded by sheath 37 as shown in figure 3 and figure 11. The trigger 32 is connected to handle 14 at pivot point 33. Although not illustrated, a through bolt that passes through the pivot point 33 and trigger 32 may hold the grip halves together and serve as the pivot point 33 of the trigger 32. The trigger 32 has a plurality of teeth 46 that are operatively associated with corresponding teeth on gear 48 housed inside handle 14. Another through bolt (not shown) may pass through a hole in the centre of gear 48. A return spring 42 is also housed inside handle 14. A first end 50 of cable 35 is connected to the trigger 32 as shown in figure 3. Alternatively, the first end 50 of cable 35 is connected to the inside of gear 48. As the first end 50 is not directly visible in figure 11, only its approximate location is indicated in figure 11. With reference to figure 3, from its first end 50, the cable 35 passes through the second end 44 of spring 42 then out of the handle 14 to launch pad 12. An opposing first end 43 of spring 42 is connected to handle 14. The second end 74 of cable 35 is operatively connected to the release collar 30 by passing end 74 through an elongated hole on the side of recess collar 30 then placing a cap on end 74. The cap on end 74 is larger than the elongated recess to prevent end 74 from being pulled back through the elongated hole and out of the release collar 30. In the alternative embodiment shown in figure 11, a compression spring 93 is used instead of return spring 42. In this alternative embodiment, the grip half or halves include a stop and a small recess to accommodate the cable 35. The first end 43 and the second end 44 have the flat end shape of the compression spring 93 instead. The second end 44 of the compression spring 93 is supported by the stop built into the grip half or halves while the first end 43 of the compression spring 93 is supported by an aluminium cable grip 90 and a spring retention washer 89. For example, grip 90 and washer 89 may be a 12 mm diameter washer that is held in place by a swaged aluminium ferrule. When compression spring 93 is used, the sheath 37 does not extend into the hollow interior of handle 14 as shown in figure 3 but instead terminates in a recess at the base of handle 14 to maximise the space available for the compression spring 93.

[0043] As seen in figure 5, the launch system 10 also has a fluid check valve 63 that minimizes the quantity of water lost from the bottle prior to launch. This prevents water draining from the bottle / rocket into the launch pad 12 and allows an accurate measure of water content in the bottle 16 at the time of launch. Fluid check valve 63 has an O-ring 67. Preferably, the fluid check valve 63 is a gravity-type check valve. In an alternative embodiment, the O-ring 67 may be replaced with a silicone rubber washer. A restraint pin 69 extends across and through the walls of the pressure spout outlet 68. O-ring 72, in addition to preventing escape of compressed air as described above, also holds the restraint pin 69 in place to prevent pin 69 from falling out of spout 58. Pin 69 retains the fluid check valve 63 within the pressure spout 58 so that valve 63 cannot fall out when the launch pad 12 is inverted as will be described below. Pin 69 also retains the fluid check valve 63 within the pressure spout 58 so that valve 63 cannot escape when the launch system 10 is under pressure. In another embodiment shown in figure 12, the fluid check valve 63 is replaced with a spring type check valve, preferably a two-part spring-loaded check valve. The spring type check valve as shown in figure 12 comprises a spring loaded fluid check valve 94, a compression spring 88, a spring retainer 87 and a silicon washer 95. When the spring type check valve is used, the restraint pin 69 also extends through the spring retainer 87. In figure 12, the O-ring 67 is replaced with the silicon washer 95.

[0044] As shown in figure 8, the launch system 10 also comprises at least one built-in pressure relief valve 83 or 84. In preferred embodiments, two pressure relief valves 83 and 84 are built-in. In some embodiments, only one pressure relief valve 83 is built-in. When a system 10 is used individually such as in figure 8, the at least one pressure relief valve is preferably set to 80 psi.

[0045] The launch system 10 can be used individually on an interior surface 76, for example a tiled floor, as shown in figure 8, or an exterior surface such as a grass field or a concreted area (not shown). The system 10 in figure 8 is connected to a manual air pump 78 via air hose 26. However, any suitable air source may be used such as an air compressor used to inflate car tyres.

[0046] Figure 9 illustrates a network of multiple launch systems 10 connected to a common air source 79 via air hose 82. Again, any suitable source of compressed air may be used. A common pressure relief valve 85 or 86 is used for all launches. In some embodiments, only one pressure relief valve 85 is built-in. The network of launch systems shown in figure 9 lie on an exterior surface 80 such as a grass field but the network may also be set up on an interior surface, if desired.

[0047] Use of the launch system 10 to fit and launch a model rocket i.e. bottle 16 will now be described.

[0048] A bottle 16 may be launched using air alone or using a combination of air and water. If using air only to launch a bottle 16, the empty bottle 16 is inverted and the bottle opening or neck 17 is fed onto and over the pressure spout 68 of the launch pad 12 in the direction of arrow A in figure 1. If a combination of air and water is used to launch a bottle 16, a predetermined amount of water is first added to bottle 16 in its normal upright position. The launch pad 12 is then inverted and the pressure spout 68 is fed down through the bottle opening and into the bottle neck 17. Fitting the launch pad 12 to the bottle 16 in this manner ensures the water content of the bottle 16 (the rocket) does not leak out prior to launch.

[0049] After the bottle 16 is fitted to the launch pad 12, the release collar 30 is raised from bracket 61 to a position surrounding bottle neck 17. This also engages the first and second restraint arms 64 and 66 onto the flange 19 on neck 17 that is found on all pressure-rated PET (polyethylene terephthalate) plastic soft drink and soda bottles 16. Resilient band 62 stretches as the restraint arms 64 and 66 engage flange 19. Arms 64 and 66 pivot about their fastening point to bracket 61.

[0050] The system(s) 10 is then pressurised using air from a compressor, manual pump or a baulk pressurised air tank as the air source connected to air hoses 26 or 82. The direction of air flow into system(s) 10 is shown by the direction of arrows B and F in figures 1 and 9. Once the system(s) 10 has been pressurised to a predetermined level the system is ready to launch the bottle 16. Figures 1 and 6 illustrate the system 10 in this locked / pre-launch configuration. A user holds the handle 14 as shown in figure 8. When launch of bottle 16 is desired, the user pulls the trigger 32 towards grip 34 in the direction of arrow C shown in figure 1. This actuates cable 36. First cable end 50 moves away from spring 42, spring 42 is stretched and the second cable end 74 is pulled down. In turn, this lowers the release collar 30 down towards bracket 61, the pair of restraint arms 64 and 66 are sprung open under the influence of band 62, and the bottle 16 is released skywards away from the launch pad 12 in the direction of arrows D and E in figures 8 and 9. The resilient band 62 retracts back to its original, unstretched, conformation. This released / post-launch configuration is shown in figure 7. The user releases trigger 32 so that it returns to the position shown in figure 1. At the same time, spring 42 also returns to its original conformation shown in figure 3. The system 10 is then ready to be used again by fitting another bottle 16 onto pressure spout 68 as described above. When compression spring 93 is used instead of return spring 42 as shown in figure 11, and the user pulls trigger 32 towards grip 34 in the direction of the curved dashed arrow G, the first cable end 50 is caused to move as shown by the curved solid arrow adjacent gear 48 in figure 11, and the compression spring 93 is compressed in the direction of the straight solid arrow depicted inside handle 14 in figure 11. Upon release of trigger 32, the bias of the compression spring 93 returns the trigger 32 to the pre-launch position shown in figure 11.

[0051] The launch system 10 of the present invention is environmentally friendly as no electrical power or batteries are required to operate the system 10. Rather, the launch is activated purely by mechanical features being the cables and pullies.

[0052] The system is preferably built making use of three dimensional printing and CNC (computer numerical control) machining techniques. This makes for a robustly built system that can be used repeatedly, with high reliability. The launch pad 12 is designed with minimal moving parts thereby reducing the number of potential failure points. The launch system 10 is thus reusable multiple times, demonstrates high reliability during operation, and delivers consistent results.

[0053] Advantageously, the launch angle can be varied to emphasize fair testing methods.

[0054] The launch system 10 preferably uses a sheathed stainless-steel cable with a trigger type release. The stainless-steel actuation cable, when used, is extremely robust. To date the present Applicant has never experienced a cable break during use of the system 10.

[0055] The launch system 10 can be operated from any surface without the need to secure the system 10 to the surface or surrounding structures in any way.

[0056] The launch system 10 preferably has a fully adjustable launch angle capability which incorporates a friction plate 38 within the support legs 18, 20 which when utilized allows the launch angle to be firmly set without fear of the system 10 toppling over.

[0057] Preferably, the launch system 10 includes two industrial grade pressure relief valves numbered as 83, 84 in figure 8 and 85, 86 in figure 9, which can be independently selected for use depending on whether launching a bottle / rocket indoors or outdoors. When two pressure relief valves are present, they are preferably connected in parallel between the air sources 78, 79 and the launch pad 12. One pressure relief valve (83 and 85) is set to 40 psi while the other (84 and 86) is set to 80 psi. When the system 10 is used outdoors, the hoses 26 and 82 between the air sources 78, 79 and the launch pad 12 are connected to the pressure relief valve that is set to 80 psi i.e. 84 and 86. When the system 10 is used indoors, the hoses between the air source and the launch pad 12 are connected to the pressure relief valve that is set to 40 psi i.e. 83 and 85. In an alternative embodiment, the launch system 10 includes only one industrial grade pressure relief valve numbered as 83 in figure 8 and 85 in figure 9. The pressure relief valve 83, 85 is still connected between the air sources 78, 79 and the launch pad 12. In this embodiment, the pressure relief valve 83, 85 is set to 80 psi.

[0058] In another embodiment, the system 10 further comprises a pressure relief valve instead of the end cap 57 next to the angle indicator 22. This is not shown. Preferably, this pressure relief valve will be set to 80 psi. This pressure relief valve also functions as an end cap.

[0059] It is not necessary for the system 10 to comprise the end caps 57. In some embodiments, an end cap 57 and a launch angle indicator 22 as illustrated are formed as one component that is connected to the end of tube 59 after passage through the support legs 18, 20. Thus, in some embodiments the system 10 comprises a launch angle indicator configured for both indicating the launch angle and covering the end of tube 59. Covering the end of tube 59 helps to prevent external elements such as dust from entering the interior of tube 59. In alternative embodiments, the end cap 57 and launch angle indicator 22 are not formed as one component. Rather, a launch angle indicator 22 is secured to tube 59 and the ends of tubes 59 remain open or uncovered. In these embodiments, the launch angle indicator is connected to the connecting tube 59 using one or more screws, such as self-tapping screws, inserted through the launch angle indicator and the tube 59. Use of screws is possible because the interior of tube 59 is not under pressure. In these embodiments, the launch angle indicator may be 3D printed and the system 10 comprises two launch angle indicators, one on each end of the connecting tubes 59 at opposing ends of launch pad 12.

[0060] In an embodiment, the bottle that is launched with the system is a soft drink bottle or a soda bottle. These are commonly sold at supermarkets and convenience stores and contain a fizzy beverage that releases gas upon opening. The beverage is emptied from the bottle prior to use with the launch system. However, any bottle that is capable of withstanding a pressure of at least about 40 psi (2.72 atm, 275.8 kPa, 2069 mm Hg) is suitable for use with the launch system of the invention. Preferably, the bottle that is launched with the system is capable of withstanding a pressure of between about 40 psi and 120 psi. At least one bottle is used with the system per launch. Preferably, one bottle is used per launch. It is also possible to fasten two or more bottles together in an end-to-end arrangement using adhesive tape and launch the fastened bottle arrangement. Hence, more than one bottle may be launched at a time using the system. The bottle or bottles may be modified prior to launch for example, by adding fins or other aesthetically pleasing features providing the pressure-holding capability of the bottle is not compromised.

[0061] In an embodiment, the launch system comprises at least two restraint arms, preferably three restraint arms, more preferably four restraint arms.

[0062] In some embodiments, the launch system includes three, two-millimeter industrial standard o-rings to achieve a positive seal of the compressed air.

[0063] In the present specification and claims (if any), the word‘comprising’ and its derivatives including‘comprises’ and‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0064] Reference throughout this specification to‘one embodiment’ or‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases‘in one embodiment’ or‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment.

Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0065] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.