Disclosed is a bicycle frame folder including two pivoted folding frames, a stop block received in between the folding frames and driven by a control lever to lock the folding frames in the closed position or to unlock the folding frames for permitting them to be opened in folding up the bicycle frame tubes connected thereto, a guide screw turned to move the stop block forwards in locking the folding frames in the closed position or backwards in releasing the folding frames, the control lever having a spring supported safety hook releasably hooked on a stub retaining rod on the lower folding frame as the folding frames are closed and locked.

A collapsible bicycle frame includes a main frame having a front frame and a rear frame. A rear end of the front frame and a front end of the rear frame are pivotally connected. The rear end of the front frame includes a first engaging mechanism while the front end of the rear frame includes a second engaging mechanism for securely engaging with the first engaging mechanism when the front frame and the rear frame are in an extended status, and the first engaging mechanism and the second engaging mechanism disengages from each other when collapsing the bicycle.

A control device carried beneath the fifth wheel of the tractor or truck of a tractor-trailer vehicle and coupled to the trailer, in which dangerous lateral movements of the trailer with respect to the tractor while under way are prevented by arresting means responsive to the vehicle brakes applied during the initial lateral movement of the trailer. The lateral travel of the trailer is stopped before it can reach a point beyond which it cannot be returned to a normal position and which might result in jackknifing. The device acts upon normal vehicle brake application by the driver and without regard to the direction or directions of lateral movement.

A pivotal device for connected two parts of a foldable bicycle includes two boards each are connected to a part of the bicycle and are pivotally connected with each other. A clutch device is connected between the two boards and includes two pins extending through the two side plates of each of the two boards. Each of the pins are movable to disengage from one of the two boards to allow the two boards to be pivoted away from each other. A secure device is connected to the clutch device so as to secure the pins of the clutch device in position such that the two boards are not pivoted away from each other.

A securing apparatus that releasably secures two or more mechanical elements is provided. The securing apparatus may be attached to one mechanical element and include abutment surfaces that abut at least one additional mechanical element. Forces exerted by the at least one additional mechanical element and the securing apparatus on each other serve to maintain the securing apparatus in a locked position. The securing apparatus may include a locking member that includes a protruded portion that extends at least partially beneath the securing apparatus and at least one mechanical element. A pull-ring may be provided to rotate the locking member and release the mechanical elements being secured. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.