Abstract: The trailer steering mechanism automatically steers the trailer wheels in accordance with the tow vehicle steering and articulation between the tow vehicle and trailer during backing maneuvers to facilitate backing maneuvers and to prevent or greatly reduce the possibility of jackknifing between tow vehicle and trailer. The mechanism includes a pivotally attached steering frame connected between the steerable wheels of the trailer and one or more hydraulic cylinders that, when locked, create a very strong link between the tow vehicle and the trailer and its steering system. An alternative embodiment employs two non-powered hydraulic cylinders in tandem. The cylinders are able to withstand great loads, and more importantly, are able to disengage while under great load without jamming. The cylinders provide links that exert lateral force to the trailer to push or pull the trailer into a turn while backing, in addition to controlling the steering mechanism of the trailer.

Abstract: The trailer steering mechanism automatically steers the trailer wheels in accordance with the tow vehicle steering and articulation between the tow vehicle and trailer during backing maneuvers to facilitate backing maneuvers and to prevent or greatly reduce the possibility of jackknifing between tow vehicle and trailer. The mechanism includes a pivotally attached steering frame connected between the steerable wheels of the trailer and one or more hydraulic cylinders that, when locked, create a very strong link between the tow vehicle and the trailer and its steering system. An alternative embodiment employs two non-powered hydraulic cylinders in tandem. The cylinders are able to withstand great loads, and more importantly, are able to disengage while under great load without jamming. The cylinders provide links that exert lateral force to the trailer to push or pull the trailer into a turn while backing, in addition to controlling the steering mechanism of the trailer.

Abstract: The trailer steering mechanism automatically steers the wheels of a trailer in accordance with the tow vehicle steering and articulation between the tow vehicle and trailer during backing maneuvers in order to facilitate backing maneuvers and to prevent or greatly reduce the possibility of jackknifing between tow vehicle and trailer. The mechanism includes a pivotally attached steering frame connected between the steerable wheels of the trailer and one or more hydraulic cylinders that, when locked, create a very strong link between the tow vehicle and the trailer and its steering system. The hydraulic cylinders are able to withstand great loads, and more importantly, are able to disengage while under great load without jamming. The hydraulic cylinders provide links that exert lateral force to the trailer to push or pull the trailer into a turn while backing, in addition to controlling the steering mechanism of the trailer.

Abstract: A dirty filter indicator device adapted for use with a furnace, an air conditioning assembly and the like. As the filter collects dirt and dust, the overall airflow is restricted causing more air to flow through the whistle device. This increased air flow through the device alerts the occupants to the need to change the air filter. The device has a canopy to prevent large dust particles from clogging the device and an adjustable nozzle element which can be adjusted to begin whistling according to the degree of dirtiness of the filter by cutting portions of the distal end of the whistle.

Abstract: A dirty filter indicator device adapted for use with a furnace, an air conditioning assembly and the like. As the filter collects dirt and dust, the overall airflow is restricted causing more air to flow through the whistle device. This increased air flow through the device alerts the occupants to the need to change the air filter. The device has a canopy cover to prevent large dust particles from clogging the device and an adjustable nozzle element which can be adjusted to begin whistling according to the degree of dirtiness of the filter by cutting portions of the distal end of the whistle.