DEPLOYMENT-RETRACTION APPARATUS FOR AIRCRAFT TURBINES

Abstract: A deployment-retraction apparatus (10) for an air turbine (12) of an aircraft movable from a stowed inoperative position within the aircraft to an extended operable position externally of and in the airstream of the aircraft, and being retractable from the extended position to the stowed position. A piston and cylinder device (30, 32) is used to extend and retract the turbine. The piston is moved to an extended position by a high force mechanical compression spring (34). The piston is moved to a retracted position by applying fluid pressure (82) in opposition to the compression spring. A mechanical latch and release mechanism (42) is operatively associated with the piston for holding the piston in retracted condition and releasing the piston upon initiation of an electrical signal (68). The fluid pressure to retract the piston is applied in response to initiating an electrical signal (78). The fluid pressure also retracts a downlock pin (72) which holds the piston in its extended position.

Description: DEPLOYMENT-RETRACTION APPARATUS FOR AIRCRAFT TURBINES Field of the Invention This invention relates to control systems for use on aircraft and, more particularly, to a deployment- retraction apparatus for an air turbine of an aircraft, or the like. Background of the Invention Deployment-retraction apparatus are used in control systems on aircraft for moving "wind motors" from' : a stowed inoperable position within the aircraft to an extended operable position externally of the aircraft and in the airstream thereof. The turbine is retractable from the extended position into the stowed position when its operation is no longer required. Such wind motors or turbines are used for driving accessories, such as hydraul¬ ic pumps, for example, on the aircraft. For instance, the accessory pump may be intended to feed the hydraulic control system with liquid under pressure, particularly in case of failure of a main hydraulic circuit to which liquid under pressure is normally fed by pump means oper¬ ated by suitable power and in particular by the engine of the aircraft. Heretofore, such deployment-retraction appara¬ tus have required considerable energy for operation, particularly significant electrical energy for deployment of the apparatus. Should such high energy sources them¬ selves become inoperative, the deployment-retraction apparatus may fail. There is a need for an improved apparatus of the character described which is capable of deploying a wind motor, such as an air turbine, from its stowed position without dependency on high energy type hydraulic or electrical power sources. Summary of the Invention An object, therefore, of the invention is to provide- a new and improved deployment-retraction appara¬ tus for an air turbine of an aircraft, or the like. Another object of the invention is to provide an~. apjxaxatus of the character described which can deploy the? a r- turbine without high energy hydraulic or electri¬ cal source: means,, by employing a high energy mechanical deployment system. In the exemplary embodiment of the invention, the deployment-retraction apparatus is provided for moving an air turbine of an aircraft from a stowed inoperable position within the aircraft to an extended operable position externally of and in the airstream of the air¬ craft, and being retractable from the extended position to the stowed position. The turbine is mounted by means to afford its extendability and retractability. Actuator means is connected to the mounting means. Latch means is provided for holding the actuator means in retracted position, and signal means is provided for releasing the latch means. A high force mechanical compression spring is provided for forcing the actuator means from its re¬ tracted- position to an extended position, and means are provided for retracting the actuator means from its ex¬ tended! position, against the force of the compression spring, to its retracted position in engagement with the latch means. More specifically, the signal means include selectively operable solenoid means for actuating a low energy release means operatively associated with the latch means. The latch means comprise mechanical linkage means including the release means. Means are provided for damping movement of the actuator means as it moves toward its extended position, and downlock means are provided for holding the actuator means in its extended position. As disclosed herein, the downlock means comprises a spring loading locking mechan¬ ism movable into locking relationship with the actuator means automatically in response to the actuator means reaching its extended position. Therefore, it can be seen that the deployment- retraction apparatus is effective to deploy the turbine ; to its extended operable position by energization of a low energy solenoid. The remaining energy for releasing the latch mechanism and moving the turbine from its stowed inoperative position to its extended operable position is provided by mechanical means, including the high force mechanical compression spring. The retracting means include means for applying fluid pressure to the actuator means in opposition to the compression spring for moving the actuator means to its retracted position. The fluid pressure is simultaneously applied to the downlock means for releasing the same to allow the actuator means to move to its retracted posi¬ tion. Signal means, including a selectively operable low energy solenoid, is provided for selectively applying the fluid pressure to the actuator means and the downlock means. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. tO -4- Description of the Drawings The features of this invention which are be¬ lieved to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best under¬ stood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in; which: FIGURE 1 is a side elevation of the deployment- retraction apparatus of the invention, with an air tur¬ bine; shown in full lines in its extended operable posi- i tion, and in phantom in its stowed inoperable position; FIGURE 2 is a longitudinal section through the deployment-retraction apparatus; and FIGURE 3 is a somewhat schematic section illus¬ trating the fluid passages of the apparatus. Description of the Preferred Embodiment Referring to the drawings in greater detail, and first to Figure 1, a deployment-retraction apparatus is generally designated 10 and is designed for use with an air turbine, generally designated 12, of an aircraft, or the like. The aircraft is shown by dashed line 14 and conventionally includes one or more compartment doors through which the air turbine moves between a stowed inopπexative position (shown in phantom) within the air¬ craft and an extended operable position externally of and in the airstream of the aircraft, as shown in full lines. Mounting means 16 is pivoted to the aircraft, as at 18, to afford air turbine 12 its extendability and retracta- bility. Deployment-retraction apparatus 10 includes an actuator 20 in the form of a cylindrical piston, with an extension 22 of a piston rod projecting from one end thereof.- Extension 22 is pivotally connected, as at 24, to mounting means 16 of the air turbine for moving the turbine between its stowed and extended positions. Referring to Figure 2, deployment-retraction apparatus 10 includes actuator means which, as stated above, includes cylindrical piston 20 and piston rod extension 22. Piston 20 is reciprocal within an outer cylinder 26, and a piston rod 28 is reciprocally mounted within an internal fluid cylinder 30. A working piston 32 is mounted on the inner end of piston rod 28. As described in greater detail, a high force mechanical compression spring 34 is provided for biasing the actua¬ tor means toward its extended position. The spring is mounted in compression condition between an annular flange 36 projecting radially outwardly from fluid cylinder 30 and an interior shoulder 38 of an end cap 40 of cylin¬ drical piston 20. Latch and release means, generally designated 42, are operably mounted in an interior compartment of a rear housing portion 44 of the apparatus. More particu¬ larly, a latch arm 46 is pivotally mounted at 48 and includes a hook portion 50 for latching engagement with a spherical end 52 of a rear extension 54 of piston rod 28. A spring 55 biases latch arm 46 and hook portion 50 in a counterclockwise or latching direction. In the position shown in Figure 2, hook portion 50 is in latching or locking engagement with spherical end 52 of the piston rod. A link arm 56 is pivotally mounted within the hous¬ ing at 58. The link arm is biased in a clockwise direc¬ tion by spring means 59 and carries a rear roller bearing 56a and a forward roller bearing 56b. Latch arm 46 is prevented from rotation in a clockwise direction by rear roller bearing 56a, and front roller bearing 56b engages the underside of a lever arm 60. The lever arm is pivotal¬ ly mounted at 62 and is biased in a clockwise direction by spring means 64. The upper end of the lever arm is biased against a rotatable, slotted pin 66. The slotted pin is rotatable by a selectively operable, low energy solenoid means 68. The operation of latch and release means 42 now will be described. As stated above, in the position of Figure 2 spherical end 52 of piston rod 28 is latched behind hook portion 50 of latch arm 46. This maintains the actuator and, therefore, the air turbine in its stowed inoperative position. Deployment is initiated by an electrical signal to low energy solenoid means 68 which rotates pin 66. The pin rotates until lever arm 60 encoun¬ ters a slot cut into the pin. Two torsion springs 64 rotate lever arm 60 in a clockwise direction as the lever arm contacts front roller bearing 56b of link arm 56. Each torsion spring is sized to handle the required load individully to provide a safety feature. Link arm 56 rotates about pivot 58 in a counterclockwise direction so that rear roller bearing 56a rotates away from and out of engagement with latch arm 46. Spring 55 then rotates the latch arm in a clockwise direction to move hook portion 50 out of engagement with spherical end 52 on extension 54 of piston rod 28. This allows high force mechanical compression spring 34 to pull on hook portion 50 and rotate latch arm 46 to thereby move the hook portion away from spherical rod end 52, releasing the latching mechan¬ ism. The compression spring initiates the deployment action, opening the appropriate compartment doors against the aerodynamic loading, and deploying air turbine 12 -7- from its stowed inoperative position to its extended operable position as shown in full lines in Figure 1. As piston 32 approaches the fully deployed position within fluid cylinder 30, damping means are included to provide shock absorption and therefore a smooth transition to a fully deployed condition. More particularly, a series of damping orifices 70 are pro¬ vided at the forward end of fluid cylinder 30, the ori¬ fices decreasing in size in a forward direction. As will be. described in greater detail hereinafter, fluid cylinder 30 is filled with liquid which is forced outwardly through damping orifices 70 for accommodating shock loads on the • actuator means at full actuator stroke. At the fully extended position, piston 32 will bottom against the forward end of fluid cylinder 30 and downlock means are provide for holding the actuator means and, therefore, the air turbine in extended position. More particularly, a downlock pin 72 is loaded by a coil spring 74 for biasing radially inwardly. Piston 28 has a reduced diameter portion 76 for receiving downlock pin 72. When the piston bottoms against the front end of cylinder 30, downlock pin 72 will be biased by spring 74 into the reduced diameter portion 76 of piston rod 28 to mechanically hold the piston, the actuator means and the air. turbine all in extended condition. From the foregoing, it can be seen that the entire deployment action of apparatus 10 has been ef¬ fected by mechanical means initiated by a simple signal to a low energy solenoid. Therefore, the system does not depend on high pressure or high energy hydraulic or electri¬ cal arrangements as in deployment-retraction apparatus heretofore available. Retraction is initiated by an electrical signal to a retract solenoid 78 shown in phantom in Figure 2. A low pressure port 80 and a high pressure port 82 are provided in the housing of apparatus 10. A high pressure shuttle valve, generally designated 84, is provided in the hydraulic system for controlling retraction. More particularly, referring to Figure 3, a somewhat schematic, sectional view illustrates the hydraul¬ ic: circuit of the deployment-retraction apparatus. For those, mechanical elements described above in relation to Figures 1 and 2, like numerals have been applied. For instance, retract solenoid valve 78, low pressure port 80,- and high pressure port 82 are shown at the rear of the illustration. The high and low pressure ports are in communication with high and low pressure sources, respec¬ tively, on the aircraft. As shown, low pressure port 80 is in communication with fluid cylinder 30 for filling the cylinder with liquid, through passages 86 and 88, shuttle valve 84, passage 90 and damping orifices 70. • Retract solenoid 78, upon initiation by an electrical signal, operates a conventional two-position, three-way valve, generally designated 92 which, upon actuation, will port high pressure liquid from the air¬ craft system to shuttle valve 84, through passages 94. The associated force will cause the valve to depress the shuttle valve spring thereby moving the shuttle valve itself. This will allow high pressure liquid to contact the underside of downlock pin 72, through passage 96. The use of a shuttle valve precludes the necessity of an extremely large solenoid valve to move the downlock pin and therefore saves weight and electrical power draw. The downlock pin is retracted against spring 74 by the high pressure liquid. Simultaneously, high pressure -9- begins to build against the forward end of piston 32. Fluid pressure on the forward face 98 of the piston over¬ comes the load of compression spring 34 to cause the piston to move toward its retract position (to the right in Figures 2 and 3) to pivot air turbine 12 toward its stowed position as shown in phantom in Figure 1. As the piston reaches it uplock position, spherical end 52 re¬ loads behind hook portion 50 of latch arm 46 (Fig. 2) and its spring 55. Roller bearing 56a of link arm 56 follows latch arm 46 and locks the latch arm in uplock condition. With the deployment-retraction apparatus 10 of this invention, the actuator means is extremely reliable ,- because the energy required to deploy the air turbine is mechanically stored by high force mechanical compression spring 34. The system does not depend on high pressure hydraulic or high energy electrical systems to operate. The energy required to release the apparatus also is stored in torsion springs and initiation of both deploy¬ ment and retraction is effected by electrical * signals to simple, small energy solenoids. It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The pres¬ ent examples and embodiments, therefore, are to be consid¬ ered in all respect as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims: CLAIMS 1. A deployment-retraction apparatus for an air turbine of an aircraft, or the like, movable from a stowed inoperable position within the aircraft to an extended operable position externally of and in the air- stream of the aircraft, and being retractable from the extended position to the stowed position, comprising: mounting means to afford the air turbine its exteaidability and retractability; actuator means connected to the mounting means; latch means for holding the actuator means in : retracted position; signal means for releasing the latch means; spring means for forcing the actuator means from its retracted position to an extended position; and means for retracting the actuator means from its extended position, against the force of the spring means, to its retracted position into engagement with the latch means. 2. The apparatus of claim 1 wherein said spring means comprises a high force mechanical compression spring, 3. The apparatus of claim 2 wherein said signal meairs includes selectively operable solenoid means for actuating release means operatively associated with the latch means. 4. The apparatus of claim 3 wherein said latch means comprise mechanical linkage means including said release means. . . -11- 5. The apparatus of claim 3, including downlock means for holding the actuator means in its extended position. 6. The apparatus of claim 5 wherein said down¬ lock means comprises a spring loaded locking mechanism movable into locking relationship with the actuator means automatically in response to the actuator means reaching its extended position. 7. The apparatus of claim 1, including means for damping movement of the actuator means as it moves toward its extended position. 8. The apparatus of claim 1 wherein said re¬ tracting means include means for applying fluid pressure to the actuator means in opposition to the spring means for moving the actuator means to its retracted position. 9. The apparatus of claim 8, including downlock means for holding the actuator means in its extended position. 10. The apparatus of claim 9 wherein said means for applying fluid pressure to the actuator means also includes means for applying fluid pressure simultan¬ eously to the downlock means for releasing the downlock means to allow the actuator means to move to its retracted position. 11. The apparatus of claim 8, including signal means for selectively applying the fluid pressure to the actuator means. 12. The apparatus of claim 11 wherein said signal means include selectively operable solenoid means for actuating valve means to release the fluid pressure to the actuator means. -13- 13. A deployment-retraction apparatus for an air turbine of an aircraft, or the like, movable from a stowed inoperative position within the aircraft to an extended operable position externally of and in the air- stream of the aircraft, and being retractable from the extended position to the stowed position, comprising: mounting means to afford the air turbine its extendability and retractability; actuator means connected to the mounting means; mechanical latch means for holding the actuator means in retracted position; electrical signal means, including solenoid ; means, for releasing the mechanical latch means; a high force mechanical compression spring for forcing the actuator means from its retracted position to an extended position; hydraulic means for retracting the actuator means from its extended position, against the force of the compression spring, to its retracted position into engagement with the latch means; and electrical signal means, including solenoid means, for initiating actuation of the hydraulic means. 14. The apparatus of claim 13 including spring means to move the latch means to a release condition in response to initiating the signal means therefor. 15. The apparatus of claim 14 wherein said latch means comprise mechanical linkage means including said release means. 16. The apparatus of claim 13, including down¬ lock means for holding the actuator means in its extended position. 17. The apparatus of claim 16 wherein said downlock means comprises a spring loaded locking mechan¬ ism movable into locking relationship with the actuator means automatically in response to the actuator means reaching its extended position. 18. The apparatus of claim 13, including means for damping movement of the actuator means as it moves . toward its extended position. 19.- The apparatus of claim 13 wherein said actuator means includes a piston and cylinder device, with said compression spring acting on the piston in a forward, extending direction, and said hydraulic means acts on the piston in a rearward, stowing direction. 20. The apparatus of claim 19, including means for damping movement of the piston as it moves toward its extended position. 21. .The apparatus of claim 20 wherein said damping means include orifice means in the cylinder, the cylinder being filled with low pressure fluid when the piston is in retracted position. 22. The apparatus of claim 19, including down¬ lock pin means for holding the piston in its extended position. -15- 23. The apparatus of claim 22 wherein the hydraulic means for retracting the piston include means for applying fluid pressure simultaneously to the down¬ lock pin for releasing the downlock pin to allow retrac¬ tion of the piston.

Inventors: COHEN MORDEHY, COHEN, MORDEHY
Applicants: SUNDSTRAND CORP, SUNDSTRAND CORPORATION
Application year: 1986
Main classification: B64D41
IPC codes: B64D41