Patent Application
20090178499
The present invention generally relates to gimbal assemblies and, more particularly, to wiring harnesses for gimbal assemblies
Gimbal assemblies that are used to translate human movements to machine movements are used in myriad industries. For example, some aircraft flight control systems include a gimbal assembly in the form of one or more control sticks (or inceptors). The flight control system, in response to input forces supplied to the control stick from the pilot, controls the movements of various aircraft flight control surfaces. No matter the particular end-use system, the gimbal assembly preferably includes some type of haptic feedback mechanism, either active or passive, back through the interface to the interface operator. The interface also typically includes one or more devices, such as a gimbal mechanism, for accurately converting angular displacements into rotary motion.
Gimbal assemblies that employ gimbal mechanisms also typically rely on various types and amounts of wiring harnesses to interconnect various switches and/or knobs on the control stick to some fixed point in the mechanism. Because the control stick is free to rotate about multiple rotational axes, the wiring also rotates and moves with the control stick. This rotation and movement can cause fatigue stress in some or all of the wiring, which can ultimately lead to electrical opens, if not properly addressed. Moreover, the mass and bending of the wiring needs to be accounted for to properly balance the interface.
Although gimbal assemblies that employ gimbal mechanisms and that address the above-mentioned concerns have been designed and manufactured, addressing these concerns can, in many instances, be the most expensive costs associated with the interface. Hence, there is a need for a gimbal mechanism that includes one or more wiring harnesses that are less susceptible to fatigue stresses as compared to present wiring harnesses and/or that do not adversely impact mechanism balance. The present invention addresses at least these needs.
In one embodiment, and by way of example only, a gimbal assembly includes a gimbal mechanism, an electrical connector, and a flexible substrate. The gimbal mechanism is configured to rotate about a first rotational axis and a second rotational axis that is perpendicular to the first rotational axis. The electrical connector is coupled to, and mounted on, the gimbal mechanism. The flexible substrate is coupled to the electrical connector and is adapted to be coupled to an external circuit for electrically interconnecting the electrical connector and the external circuit.
In another exemplary embodiment, a gimbal assembly includes a gimbal mechanism, an electrical connector, and a flexible substrate. The gimbal mechanism is configured to rotate about a first rotational axis and a second rotational axis that is perpendicular to the first rotational axis. The electrical connector is coupled to, and mounted on, the gimbal mechanism. The flexible substrate is coupled to the electrical connector and is adapted to be coupled to an external circuit for electrically interconnecting the electrical connector and the external circuit. The gimbal mechanism includes a roll hub, a pitch hub, a main hub, a main pitch shaft, a first main roll shaft, and a second main roll shaft. The roll hub is configured to rotate about the first rotational axis. The pitch hub is disposed at least partially within the roll hub and is configured rotate relative to the roll hub about the second rotational axis. The main hub is disposed at least partially within, and is coupled to, the pitch hub. The main pitch shaft is coupled to, and extends through, the main hub along the second rotational axis. The first main roll shaft is coupled to the roll hub and extends therefrom along the first rotational axis. The second main roll shaft is coupled to the roll hub and extends therefrom along the first rotational axis.
Furthermore, other desirable features and characteristics of the gimbal assembly will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. In this regard, although the following description is, for convenience, directed to a gimbal assembly implemented with a user interface that is configured as a control stick, it will be appreciated that the system could be implemented with variously configured user interfaces including, for example, variously configured pedals, yokes, levers, and the like. It will additionally be appreciated that the gimbal assembly may be used in any one of numerous applications, such as gyroscopes, that require two degrees of freedom.
A simplified representation of an exemplary embodiment of a portion of a gimbal assembly 100 is depicted in
The gimbal mechanism 104 is preferably mounted within a suitable, non-illustrated housing assembly, and is configured to allow the user interface 102 to be moved from a null position 109, which is the position depicted in
No matter the number of roll and/or pitch shafts, it is noted that if the gimbal assembly 100 is implemented in an aircraft flight control system, and used as a pilot (or co-pilot) inceptor, then the first and second rotational axes 111, 113 may be referred to as the roll axis and the pitch axis, respectively. Whether or not the gimbal assembly is implemented as such, the gimbal mechanism 104 is configured to allow the user interface 102 to be movable about the first rotational axis 111 in a port direction 112 and a starboard direction 114, and about the second axis 113 in a forward direction 116 and an aft direction 118. It will additionally be appreciated that the gimbal mechanism 104 is configured to allow the user interface 102 to be simultaneously rotated about the first and second rotational axes 111, 113 to move the user interface 102 in a combined forward-port direction, a combined forward-starboard direction, a combined aft-port direction, or a combined aft-starboard direction, and back to or through the null position 109.
Before proceeding further, it is noted that the gimbal assembly 100 may be implemented as either an active system or a passive system. If implemented as an active system, the gimbal assembly 100 may further include one or more non-illustrated motors to actively supply force feedback to the user interface 102. If implemented as a passive system, it will be appreciated that the assembly 100 would not include any motors. In either instance, however, the assembly 100 would preferably include the passive feedback mechanisms 106. In the case of the active system, the motors would be the primary means of supplying feedback force to the user interfaces 102, with the passive force feedback mechanisms 106 being the back-up feedback force source. It will nonetheless be appreciated that in the remainder of the description, the assembly 100 is described as if it were implemented as a fully passive system, without any motors.
As previously noted, the user interface switches 103, knobs 105, and/or sensors are each electrically coupled to one or more non-illustrated external circuits via the flexible substrate 106. To facilitate this electrical interconnection, the gimbal assembly 100 additionally includes an electrical connector 120 that is coupled to, and mounted on, the gimbal mechanism 104. The electrical connector 120 is electrically coupled to the switches 103, knobs 105, and or sensors via suitable, non-illustrated wiring or various other interconnections.
The flexible substrate 106 is coupled to the electrical connector 120 and is adapted to be coupled to the one or more non-illustrated external circuits that were previously mentioned. In this manner the flexible substrate 106 electrically interconnects the electrical connector 120, and thus the user interface switches 103, knobs 105, and/or sensors, to these one or more external circuits. The flexible substrate 106 may be coupled to the electrical connector 120 using any one of numerous techniques. For example, the flexible substrate 106 may be soldered to the electrical connector 120, inserted into the electrical connector 120, or formed as an integral part of the electrical connector 120, just to name a few. A particular preferred technique that is used to couple to flexible substrate 106 and the electrical connector is depicted in
In accordance with the preferred technique, the electrical connector 120 includes a plurality of pins 202 and the flexible substrate 106 includes a plurality of openings 204. The pins 202 are disposed in a particular pattern and are electrically coupled to the switches 103, knobs 105, and/or sensors via suitable conductors. These conductors may include, for example, wires, receptacles configured to receive the pins 202 therein, or combinations of each. In any case, it is seen that the flexible substrate openings 204 are disposed in a pattern that matches the pattern in which the pins 202 are disposed.
The flexible substrate 106 may be variously configured, but in the depicted embodiment, and with reference to
It is noted that the flexible substrate 106, as just described, is preferably implemented with multiple arms. By doing so, the overall spring forces associated with the flexing of the flexible substrate 106 during gimbal mechanism operation can be essentially canceled. As a result, the gimbal mechanism 104, and thus the user interface 102, will readily and repeatedly return to its zero-force, null position 109. Moreover, as
It is further noted that although the flexible substrate 106 depicted in
In some embodiments, the flexible substrate 106 may include one or more additional elements to thereby implement one or more additional functions. For example, as
As
It was noted above that a description of a particular physical implementation of the gimbal mechanism 104 that includes two roll shafts 108 could be provided. With reference now to
The pitch hub 404 is disposed, at least partially, within the roll hub 402 and is configured to rotate relative to the roll hub 402 about the second rotational axis 113. To implement this relative rotation, the gimbal mechanism 104 further includes a plurality of pitch hub bearings 416 (e.g., 416-1, 416-4). The pitch hub bearings 416 are each disposed between the roll hub 402 and the pitch hub 404, and include an inner race, an outer race, and a plurality of bearing balls disposed between the inner and outer races. The pitch hub bearing inner races are mounted on the pitch hub 404, and the pitch hub bearing outer races engage the roll hub 402.
The pitch hub bearings 416 are each retained in position, preferably in a free floating manner, via a pitch hub bearing retaining ring 422 and a pitch hub bearing spring 424. More specifically, each pitch hub bearing retaining ring 422 is disposed within a non-illustrated groove formed in the pitch hub 404. The pitch hub bearing springs 424, which in the depicted embodiment are implemented using spring washers, are each disposed between one of the pitch hub bearing retaining rings 422 and one of the pitch hub bearings 416. In the depicted embodiment, only a single pitch hub bearing spring 424 is disposed between each pitch hub bearing 416 and pitch hub bearing retaining ring 422. It will be appreciated, however, that more than one pitch hub bearing spring 424 could be used, if needed or desired. No matter the number of pitch hub bearing springs 424 that are used, each supplies a bias force to one of the pitch hub bearings 416 that pre-loads the pitch hub bearings 416 axially inwardly toward the pitch hub 404, in a free-floating manner. As
The main hub 406 is disposed, at least partially, within the pitch hub 404, and is additionally coupled to the pitch hub 404. In the depicted embodiment, the main hub 406 is coupled to the pitch hub 404 via a plurality of shafts 428; namely, a first minor pitch shaft 428-1 and a second minor pitch shaft 428-2. The first and second minor pitch shafts 428-1, 428-2 are each coupled to the main hub 406 via, for example, suitable non-illustrated pins. The first and second minor pitch shafts 428-1, 428-2 each extend, in opposite directions along a third rotational axis that is perpendicular to the first and second rotational axes 111, 113, from the main hub 406 into first and second bearing cavities 432-1, 432-2, respectively, formed in the pitch hub 404. A first minor pitch shaft bearing 434-1 is disposed in the first bearing cavity 432-1, and a second minor pitch shaft bearing 434-2 is disposed in the second bearing cavity 432-2. The first minor pitch shaft bearing 434-1 is mounted on the first minor pitch shaft 428-1, and is disposed between the first minor pitch shaft 428-1 and the pitch hub 404. Similarly, the second minor pitch shaft bearing 434-2 is mounted on the second minor pitch shaft 428-2, and is disposed between the second minor pitch shaft 428-2 and the pitch hub 404. The minor pitch shaft bearings 434 each include an inner race, an outer race, and a plurality of bearing balls disposed between the inner and outer races. The minor pitch shaft bearing inner races are each mounted on one of the minor pitch shafts 428-1, 428-4, and the minor pitch shaft bearing outer races each engage an inner surface of one of the roll hub bearing cavities 432-1, 432-4. As a result, the first and second minor pitch shafts 428-1, 428-2 may rotate relative to the pitch hub 404 about the third rotational axis.
The minor pitch shaft bearings 434, similar to the pitch hub bearings 416, are each retained in position, in a free floating manner, via a minor roll shaft bearing retaining ring 436 and a minor roll shaft bearing spring 438. More specifically, each minor pitch shaft bearing retaining ring 436 is disposed within a groove formed in each of the minor pitch shafts 428. The minor roll shaft bearing springs 438, which in the depicted embodiment are also implemented using spring washers, are each disposed between a non-illustrated annular spring retaining surface formed on each minor pitch shaft 428 and one of the minor pitch shaft bearings 434. In the depicted embodiment, only a single minor pitch shaft bearing spring 438 is disposed between each annular spring retaining surface and minor pitch shaft bearing retaining ring 436. It will be appreciated, however, that more than one minor pitch shaft bearing spring 438 could be used, if needed or desired. No matter the number of minor pitch shaft bearing springs 438 that are used, each preferably supplies a bias force to one of the minor pitch shaft bearings 434 that pre-loads the minor pitch shaft bearings 434 outwardly away from the annular spring retaining surface, preferably in a free-floating manner. As
The main pitch shaft 410 extends through the main hub 406, and thus through the pitch hub 404 and the roll hub 402, along the second rotational axis 113. The main pitch shaft 410 includes a plurality of integral roll stop surfaces 446 and a minor roll shaft opening 448. The main pitch shaft 410 may be rotationally mounted to via a set of non-illustrated main pitch shaft bearing assemblies. As such, the main pitch shaft 410 is rotatable about the second rotational axis 113. The integral roll stop surfaces 446 are formed on the main pitch shaft 410 and limit rotation of the main hub 406 and, concomitantly, the user interface 102, about the first rotational axis 111. The minor roll shaft opening 448 extends through the main pitch shaft 410 and is configured to receive a minor roll shaft 450.
The minor roll shaft 450 extends into and through the minor roll shaft opening 448 along the first rotational axis 111. It may thus be appreciated that the minor roll shaft 450 is disposed perpendicular to the main pitch shaft 410. The minor roll shaft 450 is coupled to the main pitch shaft 410 via, for example, a dowel pin 451, and the ends of the minor roll shaft 450 extend into minor roll shaft bearing cavities 454 formed in the main hub 406. A minor roll shaft bearing 456 (e.g., 456-1, 456-2) is disposed in each minor roll shaft bearing cavity 454. The minor roll shaft bearings 456 are mounted on the minor roll shaft 450, and are disposed between the minor roll shaft 450 and the main hub 406. The minor roll shaft bearings 456, like each of the previously-described bearings, preferably include an inner race, an outer race, and a plurality of bearing balls disposed between the inner and outer races. The minor roll shaft bearing inner races are each mounted on the minor roll shaft 450, and the minor roll shaft bearing outer races each engage an inner surface of one of the minor roll shaft bearing cavities 454. As a result, relative rotation about the third rotational axis may occur between the minor roll shaft 450 and the main hub 406.
The minor roll shaft bearings 456 are retained in position, in a free floating manner, similar to how each of the minor pitch shaft bearings 434 are retained in position. In particular, a non-illustrated first groove and a non-illustrated second groove are formed in the minor roll shaft 450 adjacent a first end and a second end, respectively, thereof. A first retaining ring 458-1 is disposed within the first groove, and a second retaining ring 458-2 is disposed in the second groove. A minor roll shaft bearing spring 462, which in the depicted embodiment is also implemented using a spring washer, is disposed within each main hub bearing cavity 454 between the main pitch shaft 410 and each of the minor roll shaft bearings 456. More specifically, because of the manner in which the minor roll shaft 450 is configured in the depicted embodiment, one of the minor roll shaft bearing springs 462-2 is disposed between a minor roll shaft bearing 456-2 and a non-illustrated annular retaining surface formed on the minor roll shaft 450, and the other minor roll shaft bearing spring 462-1 is disposed between the other minor roll shaft bearing 456-1 and a spring retaining shim 464 that is disposed over the minor roll shaft 450. Although a single minor roll shaft bearing spring 462 is disposed within each main hub bearing cavity 454, it will be appreciated that more than one minor roll shaft bearing spring 462 could be used, if needed or desired. Moreover, no matter the number of minor roll shaft bearing springs 462 that are used, each supplies a bias force to one of the minor roll shaft bearings 456 that pre-loads the minor roll shaft bearings 456 outwardly away from the main pitch shaft 410, preferably in a free-floating manner. One or more suitably sized shims 466, 468 may be disposed between each minor roll shaft bearing 456 and each minor roll shaft bearing spring 462 and/or each minor roll shaft retaining ring 458, as needed or desired.
In addition to each of the above-described components the gimbal mechanism 104, at least in the depicted embodiment, additionally includes a control base 472, a user interface mounting post 474, and a rigging bracket 476. The control base 472 is coupled to the pitch hub 404 and is disposed over the pitch hub first bearing cavity 434-1. The control base 472 is additionally coupled to the user interface mounting post 474. In the depicted embodiment, as shown most clearly in
The gimbal mechanism 104 described above and depicted in
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.
