Thrust vector adjustment device

Abstract

The present invention provides a robust means of adjusting the angular mounting of thrust producing devices such as airplane engines. The device provides independent adjustment of the thrust vector for each axis and offset adjustment to maintain the center line of the engine. A means of indicating the angle of adjustment is inherent in the design. The invention also provides for an opening along the centerline to accommodate power take-off shafts or to mount jet or ducted fan engines.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] Not Applicable. 1 X Y X Y Y* SETTING SETTING VECTOR X* VECTOR POSI- (degrees) (degrees) (degrees) POSITION (degrees) TION 10.0 0.0 0.0722 0.0063 0.0 0.0 20.0 0.0 0.3004 0.0262 0.0 0.0 30.0 0.0 0.7236 0.0631 0.0 0.0 0.0 10.0 0.0 0.0 0.0722 0.0063 0.0 20.0 0.0 0.0 0.3004 0.0262 0.0 30.0 0.0 0.0 0.7236 0.0631 10.0 10.0 0.0722 0.0063 0.0722 0.0063 20.0 10.0 0.3004 0.0262 0.0722 0.0063 *Note: The X and Y positions are determined using a vector five (5) units long with an origin at the center of the Y top plate and perpendicular to that plate in both X and Y planes. The angle of the wedges for both axes is 4.70 degrees.

BACKGROUND OF THE INVENTION

[0002] On large scale radio controlled aircraft piston engines that are used to provide thrust need to be mounted at different vertical and horizontal angles relative to the aircraft's centerline to counter act torque effects of the engine. On a particular aircraft design or kit, engines with different power ratings require angles unique to that engine. The present state-of-the-art requires the use of different quantities of washers be placed under each of four mounting bolts to generate these angles. Another approach is to drill offset mounting holes in longitudinal mounting rails (U.S. Pat. No. 5,303,896 by Sterka addresses vibration issues, but shows only these longitudinal mounting rails). Other similar approaches are used, but are either tedious to adjust (as in adding and removing washers) and/or prone to vibration induced failures. Some approaches that have been proposed (U.S. Pat. No. 5,505,423 by Kusijanovic and U.S. Pat. No. 4,249,711 by Godbersen) solve some of these problems, but do not provide a method to indicate what the angle has been set to. Also, existing approaches do not provide translational adjustment required to counteract the induced translation caused by the angular adjustments. This invention also provides for the mounting of jet engines and ducted fan engines (as in U.S. Pat. No. 5,238,205 by Gleichauf) but also provides for pointing of the thrust vector of those engines.

BRIEF SUMMARY OF THE INVENTION

[0003] A bulkhead (typically called the firewall) that has provision for making angular adjustments and the counteracting translational adjustments in the field. The angular adjustment for each axis is provided by a pair of wedge shaped disks (Plates 1 & 2 in one axis and plates 3 & 4 in the other axis) that produce a change in angle as they are rotated relative to each other about a common axis. One pair of disks provides angular adjustment in pitch (Y axis) and the other pair in yaw (X axis). The angled surfaces of Plates 1 & 2 face each other and rotate about a common axis. The engine is mounted to the most forward disk (Plate 4). This plate (Plate 4) can be adjusted in the Y direction to counteract the induced vertical translation in that axis. This base (Plate 1) is mounted to the firewall which can be adjusted in the X direction to counteract the induced translation along that axis.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING

[0004] FIG. 1 is an overall view of the invention with the firewall of the aircraft at the bottom and the engine at the top.

[0005] FIG. 2 is a plan and side view of the adjusting plate which is show as being identical for each axis.

[0006] FIG. 3 is a plan and side view of the base plate for the device that mounts to the firewall.

[0007] FIG. 4 is a plan and side view of the top plate for the device that the engine mounts to.

DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention provides a robust means of adjusting the angular mounting of thrust producing devices such as airplane engines.

[0009] The method for providing this adjustment in both the Y and X axes is by the rotation of angular plates, one set for each axis. FIG. 1 shows the X-axis adjusting plate 2 and the Y-axis adjusting plate 3. These plates rotate about a common axis 10 and are retained tightly via four bolts 11 between a top plate 4 and a base plate 1. The device 16 (assumed here to be a piston engine) to be vectored or pointed is mounted via stand-offs 18, bolts 20 and nuts 21 onto the top plate 4. The four bolts 11 mount this assemblage to the base plate 1. The base plate 1 is mounted to the assembly 17 (typically the firewall of the aircraft) requiring the device 16 via four mounting bolts 22 and stand-offs 19.

[0010] FIG. 2 shows the detail of the adjusting plates 2 and 3. These are show as identical plates which are mounted 90 degrees from each other and the bases mounted against each other as shown in FIG. 1. The plates have four slots 5 that accept bolts 11 and allow their rotation about a common axis 10 shown in FIG. 1. A pointer 15 is inscribed on tab 6 to provide an indication of the amount of angular adjustment being made. For devices 16 which have a through shaft (as in an engine application that has a rear power take-off) a clearance hole 7 is provided. The nature of the design does not limit the size of this hole 7 and therefore, supports jet engines or ducted fan engines that would be mounted in this hole. The slope of the adjusting plate 2 or 3 can be made in various angles for different applications. The angle can also be made different between plate 2 and plate 3 if the range of adjustment in the X-axis is required to be different from the Y-axis. The plates 2 and 3 are circular to provide clearance when they are rotated for top plate 4 mounting hardware 20 and 21 and base plate 1 mounting bolts 22.

[0011] FIG. 3 shows the detail of the base plate 1. Four threaded holes 8 provide anti-rotation mounting via bolts 11 for the top plate 4. Clearance hole 7 is also provided as in the adjustment plates 2 and 3. Indication scribe lines 23 are provided for the pointer 15 on the adjusting plate 2 to indicate how much adjustment has been made. The slots 13 for the mounting bolts 22 into the assembly 17 allow for the elimination (if required) of lateral offsets caused be the angular adjustment of plates 2 and 3. Stand-offs 19 provide clearance for adjusting bolts 11. Stand-offs 19 and bolts 22 can be replaced by vibration isolation mounts as described by Sterka in U.S. Pat. No. 5,3003,896, but this is not a requirement for the operation of the invention.

[0012] FIG. 4 shows the detail of the top plate 4. Four clearance holes 9 provide anti-rotation mounting via bolts 11 down to the base plate 1. Clearance hole 7 is also provided as in the adjustment plates 2 and 3. Indication scribe lines 23 are provided for the pointer 15 on the adjusting plate 3 to indicate how much adjustment has been made. A mirror is needed to read this indication as it is on the downward facing surface of the top plate 4 when assembled. The slots 14 for the mounting hardware 20 and 21 allow for the elimination (if required) of lateral offsets caused be the angular adjustment of plates 2 and 3. Stand-offs 18 provide clearance for adjusting bolts 11.

[0013] The operation of the invention is best understood by observing FIG. 1. Four bolts 11 are passed through four springs 12, the top plate 4, adjusting plates 2 and 3 and screwed into the threaded holes 8 in the base plate 1. The bolts 11 are initially tightened until there is a slight clamping force exerted by the springs 12. The base plate 1 is then initially loosely mounted to the primary assembly 17 using bolts 22 and stand-offs 19. The device 16 to be pointed or vectored is initially loosely fastened to top plate 4 via fasteners 20 and 21 and four spacers 18. The angular adjustments are then made by rotating plates 2 and 3. Plate 2 is used for X-axis adjustment and plate 3 is used for Y-axis adjustment. No interaction occurs between the two axes. Upon completion of the angular adjustments, bolts 11 are tightened until springs 12 are fully compressed. Plates 1 and 4 are then adjusted (if required by the application) to remove any inducted lateral movement of device 16. Fasteners 20 and 21 are then tightened to secure the device 16 to the top plate 4 and fasteners 22 are tightened to secure the whole adjusting device to the assembly 17.

Claims

1. The invention provides stable mounting with adjustable thrust vector control for motors and engines for model aircraft or remotely piloted vehicles comprising:

a disk for each axis that by rotating said disk provides an angular change of the thrust vector for one axis without effecting the thrust vector of the other axis,

an indicator on each adjustment disk that gives an indication of the setting for that axis,

provision for adjustment in translation for each axis to counteract the induced translation along that axis when the angular change is made in the thrust vector.

2. The method for providing the adjustment in claim 1 in both the Y and X axes is by the rotation of angular plates (wedges), one set for each axis.

3. Plates in claim 2 that have different angles for each axis, thus providing a different range of adjustment for each axis.

4. One or more additional adjusting plates from claim 3 to provide coarse pointing (one pair of plates) and fine pointing (the second pair of plates).

5. For devices to be pointed or vectored which require a centerline opening (as in a piston engine with a rear power take-off, a jet engine or a ducted fan engine) a clearance hole through the center is provided.