Abstract: An elevator climbs and lifts loads along the length of a double ladder. The double ladder comprises a first ladder and a second ladder that join together to form an overlap portion. The overlap portion is wider and generally less stable than the individual ladders. The elevator helps overcome the physical barriers imposed at the overlap portion. The elevator utilizes guiding mechanisms having different orientations and designs to smoothly cross over misalignments and instable structures in the double ladder. The elevator includes a housing. The underside of the housing includes guide units that ride the side rails to align a first ladder and a second ladder. Rollers press the housing in contact to the ladders. Notched rollers suppress vibrations on the housing. The guide mechanisms selectively engage the ladders and the overlap portion based on the position of the elevator. A motorized platform extends from the housing.

Abstract: A portable barrier for a door sill that comprises of a restriction bar, a mount bar that is disposed on the restriction bar, a connection tube that joins the restriction bar with the mount bar, and an adjustable spring mechanism that allows the mount bar to be adjusted upward or downward. The adjustable mechanism comprises springs and screws that can be manually adjusted.

Abstract: A mobile ladder support assembly provides stable lateral and rear support, and transportability for operation of a ladder. A lateral support bar restricts lateral tilting by the assembly. A pair of height adjustable rear support bars restrict backwards tilting by the assembly. A pair of caster wheels transport the assembly and the ladder. The wheels ride a pivot bar that rotates in a first direction for a stationary position. When the pivot bar is manipulated towards the second direction, the pair of wheels drop to a mobile position. Springs at the ends of the pivot bar create tension that maintains the pivot bar in the first position. Tabs selectively engage a notches to retain the wheels in the stationary position, or release the wheels to the mobile position. The free rotation and swivel of the wheels creates a center of mass that drop the wheels to the mobile position.

Abstract: A portable barrier for a door sill fills a gap between the flooring and the bottom of a respective door to restrict passage of water, air, and pests. The barrier detachably mounts into a door sill on an exterior side of the door. The barrier is height adjustable, so as to enable the dual function of inhibiting passage through the gap beneath the door, and enabling passage of a wheeled vehicle over the barrier. A restriction bar provides the barrier function. The restriction bar has a tapered edge to enable a wheel to roll over it. A mount bar is disposed parallel to the restriction bar for mounting to the flooring. A spring biases the restriction bar towards an extended position for expanding above the door sill. The spring compresses to enable the restriction bar to move towards the mount bar. A bolt passes through and aligns the components.

Abstract: A mobile ladder support assembly provides stable lateral and rear support, and transportability for operation of a ladder. A lateral support bar restricts lateral tilting by the assembly. A pair of height adjustable rear support bars restrict backwards tilting by the assembly. A pair of caster wheels transport the assembly and the ladder. The wheels ride a pivot bar that rotates in a first direction for a stationary position. When the pivot bar is manipulated towards the second direction, the pair of wheels drop to a mobile position. Springs at the ends of the pivot bar create tension that maintains the pivot bar in the first position. Tabs selectively engage a notches to retain the wheels in the stationary position, or release the wheels to the mobile position. The free rotation and swivel of the wheels creates a center of mass that drop the wheels to the mobile position.

Abstract: An elevator climbs and lifts loads along the length of a double ladder. The double ladder comprises a first ladder and a second ladder that join together to form an overlap portion. The overlap portion is wider and generally less stable than the individual ladders. The elevator helps overcome the physical barriers imposed at the overlap portion. The elevator utilizes guiding mechanisms having different orientations and designs to smoothly cross over misalignments and instable structures in the double ladder. The elevator includes a housing. The underside of the housing includes guide units that ride the side rails to align a first ladder and a second ladder. Rollers press the housing in contact to the ladders. Notched rollers suppress vibrations on the housing. The guide mechanisms selectively engage the ladders and the overlap portion based on the position of the elevator. A motorized platform extends from the housing.