General aviation portable electric towbar
A general aviation portable electric towbar that uses a frame to couple to the aircraft on one end, has a handle on the other end for the operator to press a drive roller against the wheel to be driven. The chuck of a drill directly mounts to a drive roller shaft without any other method of motion transfer. Since the drill is mounted on the opposite end as the handle, the drill is controlled by a remote trigger mechanism. Since this configuration can use a drill that is commonly available that directly drives a drive roller without any other method of motion transfer, this device has few parts which reduces weight, costs and complexity, making for a simple, reliable, lightweight and affordable portable electric towbar for general aviation use.
1 . A general aviation portable electric towbar apparatus for moving an aircraft, comprising:
a frame having an attachment mechanism configured to detachably couple to an aircraft wheel, the frame configured to allow lateral movement to control the direction of tow and vertical movement to apply a force for pressing a drive roller into the wheel being driven;
a drive roller supported by the frame that is configured to push against the wheel being driven, the drive roller having an axis of rotation parallel to that of an axis of rotation of the wheel being driven;
a drill with a chuck and a drill trigger, the chuck that mounts directly to a shaft of the drive roller without any other method of motion transfer between the two;
a handle coupled to the frame such that the handle is used to apply a vertical force to press the drive roller into the wheel being driven and a lateral force to move the wheel from side to side for steering; and
a remote trigger mechanism configured to activate the drill trigger from the handle end of the frame.
2 . The towbar apparatus of claim 1 , wherein the location of contact of the drive roller to the wheel being driven is such that a resultant tangential force vector acts through or near the mounting point of the towbar to reduce a torque reaction that the drill generates onto the handle, thereby reducing an opposite force needed.
3 . The towbar apparatus of claim 1 , wherein an additional structural member is attached between the towbar and aircraft to react the torque from the drill.
4 . The towbar apparatus of claim 1 , wherein the remote trigger mechanism comprises an orthogonal trigger pusher that is rotatably coupled on the frame with one end pressing against the drill trigger and the other end connected to a string or cable that runs up to the handle to a ring that can be pulled to activate the drill trigger.
5 . The towbar apparatus of claim 1 , wherein the remote trigger mechanism comprises a cable that runs through a housing to apply a force on the drill trigger.
6 . The towbar apparatus of claim 1 , wherein the remote trigger mechanism is a hydraulic system with a master cylinder actuated at the handle and slave cylinder at the drill to actuator the drill trigger.
7 . The towbar apparatus of claim 1 , wherein the remote trigger mechanism is configured with an electric actuator to apply the force on the drill trigger.
8 . The towbar apparatus of claim 1 , wherein the remote trigger mechanism is activated by a lever at the handle to apply the force on the drill trigger.
9 . The towbar apparatus of claim 1 , wherein the frame is collapsible and folds or telescopes to save storage space with spring loaded pins for quick release and locking.
10 . The towbar apparatus of claim 1 , wherein the attachment mechanism of the frame to couple to the aircraft comprises sliding pins to engage the towbar frame to the aircraft.
11 . The towbar apparatus of claim 1 , wherein the attachment mechanism of the frame to couple to the aircraft comprises an engagement of one or more rods and/or holes to interface to mating features of the aircraft.
12 . The towbar apparatus of claim 1 , wherein the attachment mechanism of the frame to couple to the aircraft is a clamp that is either threaded or spring loaded.