Patent GB-1228344-A (GB)
IPC: F02K9/60
Filed: 1969-01-27
Abstract: 1,228,344. Toy rockets. VASHON INDUSTRIES Inc. 27 Jan., 1969 [26 Jan., 1968], No. 4393/69. Heading B7W. [Also in Divisions F1 and F3] A rocket unit constructed as a toy comprises a body which defines a chamber for containing a liquefied gas propellant, a propulsion nozzle disposed at one end of the chamber through which the fluid discharges to provide thrust, means for retaining a plug in a closing position within the nozzle and selectively operable means for releasing the plug so as to initiate "firing" of the rocket. The rocket shown in Figs. 1 and 2 comprises a body 1 which defines a propellant container, a thrust nozzle 6, and a nose cone 3 which is secured to the body 1 by a release section 4. The rocket comprises fins 2 and is mounted on a launch device 8, 9 by means of guides 68, 69. The body 1 comprises an upper end wall 11 and a lower end wall 32, also a filling device 26 and a pressure relief valve 18. The body is filled with liquefied gas such as a fluorinated hydrocarbon from a container. A thrust nozzle 6 is mounted in the lower end wall 32, a nozzle extension 37 being secured to the nozzle 6. A nozzle closure plug 7 is initially retained within the orifice of the nozzle by means of a fusible wire 39 which is clamped between the nozzle 6 and nozzle extension 37 and extends between an electrically conductive cap 43 and the closure plug 7, an insulating layer 48 being provided between the plug 7 and the cap. Leads 44, 47 are connected to the cap 43 and the nozzle plug. A locking pin 37a is also provided to retain the nozzle plug. The release unit 4 comprises end walls 49, 51, the unit 4 being secured to the body 1 by engaging the screwed member 52 with the member 53. A member 58 formed with a central bore 59 extends across the unit 4, and a diaphragm 57 co-operates with the member 58. A plug member 56 engages the diaphragm and may engage with a flexible member 61 which when deformed locks the nose cone 3 to the unit 4. A small bore pipe 66 places the chamber below the member 58 in communication with the propellant chamber. When the chamber is filled with liquefied gas under pressure the pressure is communicated to the space below member 58, the diaphragm extends and the plug 56 deforms the member 61 to lock the parts together. To "fire" the rocket, the locking pin 37a is removed, current is passed through the circuit 44, 47 to fuse the wire 39 whereby the pressure within the chamber ejects the nozzle plug and the propellant discharges through the nozzle, being vaporized in the process. When the propellant chamber is empty, the pressure below the diaphragm 57 also falls after a time interval, the locking member 61 is released and the nose cone separates and is returned by parachute. The invention may be applied to a two-stage unit, Fig. 7, the first stage being releasably connected to the second stage by a device 81 similar to 61 in Fig. 2, a closure plug 73 for the second stage nozzle 76 being connected to the first stage unit so that as the first stage separates it withdraws the plug from the second stage nozzle and the second stage unit then "fires". In Fig. 8 two first-stage rocket units 82, 83 are mounted laterally of the second stage unit 93. Each first stage unit comprises a flexible diaphragm 57 and plug member 56 as in Fig. 2 so that when the propellant chamber is under pressure the plug member 56 is moved upwardly and the contact 86 is moved away from the fixed contact 87. When the pressure within the propellant chamber falls the member 56 moves downwardly, the contacts 86, 87 close and current passes to the fusible wire 39 whereby the nozzle plug of the second stage rocket unit is released and the second stage thus "fires", the two first stage units falling away.