Abstract: A hitch and ball alignment device for aligning a tow ball with a trailer tongue includes a first sensing unit and a controller. The first sensing unit comprises a first sensor, which is position type, and a first transmitter. A first coupler is coupled to the first sensing unit and is configured to removably couple the first sensing unit to one of a tow ball, which is coupled to a vehicle, and a trailer tongue. The controller comprises a screen and a receiver. The first sensor is configured to determine a distance between the first sensing unit and the other of the tow ball and the trailer tongue and to signal the controller via the first transmitter. The controller is positioned display the positions of the tow ball and the trailer tongue on the screen to guide a user to align the tow ball with the trailer tongue.

Abstract: A hitch and ball alignment device for aligning a tow ball with a trailer tongue includes a first sensing unit and a controller. The first sensing unit comprises a first sensor, which is position type, and a first transmitter. A first coupler is coupled to the first sensing unit and is configured to removably couple the first sensing unit to one of a tow ball, which is coupled to a vehicle, and a trailer tongue. The controller comprises a screen and a receiver. The first sensor is configured to determine a distance between the first sensing unit and the other of the tow ball and the trailer tongue and to signal the controller via the first transmitter. The controller is positioned display the positions of the tow ball and the trailer tongue on the screen to guide a user to align the tow ball with the trailer tongue.

Abstract: An overload warning device for use in a crane having a telescopic jib which includes, in a transmission between a slave jib and a pointer, a bank of cams each appropriate for a different length of jib, a common follower cooperable with the cams, and a selector mechanism operable automatically in response to change in the jib length for effecting relative movement between the follower and the cams to bring the follower into cooperation with the cam corresponding to the newly selected jib length.