The invention relates to an actuating device for an approximately horizontal mobile platform that is able to be set in movement in a vertical direction between a high position and a low position, and having a frame supporting the platform, said actuating device having at least one rigid chain actuated by at least one motor secured to the frame, and a guide member for guiding the rigid chain between a position substantially extended in the direction of the ground and a position substantially stowed parallel to the frame.

The invention relates to an actuating device for an approximately horizontal mobile platform that is able to be set in movement in a vertical direction between a high position and a low position, and having a frame supporting the platform, said actuating device having at least one rigid chain actuated by at least one motor secured to the frame, and a guide member for guiding the rigid chain between a position substantially extended in the direction of the ground and a position substantially stowed parallel to the frame.

The invention relates to an actuating device for an approximately horizontal mobile platform that is able to be set in movement in a vertical direction between a high position and a low position, and having a frame supporting the platform, said actuating device having at least one rigid chain actuated by at least one motor secured to the frame, and a guide member for guiding the rigid chain between a position substantially extended in the direction of the ground and a position substantially stowed parallel to the frame.

A vertically movable workpiece support device has a ratchet wheel with a larger diameter than the outer diameter of a driving sprocket wheel and is concentrically attached to an end surface of a boss portion in the driving sprocket wheel. A pair of left and right bearing members are provided side by side, on a side on which the free end side of a drive chain is horizontally extended with respect to the driving sprocket wheel, so as to sandwich a horizontally extending path section of the drive chain. A movable pawl is pivotally supported between the pair of left and right bearing members and engages with the ratchet wheel to block the rotation of the ratchet wheel caused by the movement of the drive chain when the workpiece support base is lowered. An actuator switches the movable pawl to a non-action position with respect to the ratchet wheel.

A vertically movable workpiece support device has a ratchet wheel with a larger diameter than the outer diameter of a driving sprocket wheel and is concentrically attached to an end surface of a boss portion in the driving sprocket wheel. A pair of left and right bearing members are provided side by side, on a side on which the free end side of a drive chain is horizontally extended with respect to the driving sprocket wheel, so as to sandwich a horizontally extending path section of the drive chain. A movable pawl is pivotally supported between the pair of left and right bearing members and engages with the ratchet wheel to block the rotation of the ratchet wheel caused by the movement of the drive chain when the workpiece support base is lowered. An actuator switches the movable pawl to a non-action position with respect to the ratchet wheel.

A vertically movable workpiece support device has a drive chain bendable to only one side which supports a workpiece support base in a vertically linear path section. The drive chain extends from one end portion coupled to the workpiece support base to an intermediate portion engaging with a driving sprocket wheel. A chain guide plate which sandwiches, with the driving sprocket wheel, a link-to-link roller of the drive chain is arranged on an outer side of the driving sprocket wheel. A mark is displayed, on the side surface of the chain guide plate, in a position separated a certain distance outward from a turning path of links in the drive chain, and an opening portion for visually checking the mark is provided in a side wall which pivotally supports the driving sprocket wheel.

A vertically movable workpiece support device has a drive chain bendable to only one side which supports a workpiece support base in a vertically linear path section. The drive chain extends from one end portion coupled to the workpiece support base to an intermediate portion engaging with a driving sprocket wheel. A chain guide plate which sandwiches, with the driving sprocket wheel, a link-to-link roller of the drive chain is arranged on an outer side of the driving sprocket wheel. A mark is displayed, on the side surface of the chain guide plate, in a position separated a certain distance outward from a turning path of links in the drive chain, and an opening portion for visually checking the mark is provided in a side wall which pivotally supports the driving sprocket wheel.

A thrust lifting device that is able to transmit a thrust force for lifting loads, includes at least one articulated lift column provided with at least one meshing part, and with at least one arm directed upward from the meshing part, the lift column made up of links with a link of rank 1 at the upper end of the upwardly directed arm and running links of rank n, where n is between 2 and N, the number of links of the lift column, at least one rotary pinion driving the lift column by the meshing part meshing with the pinion, at least one arm opposite the upwardly directed arm and formed by resting links, the resting links being able to pass to the meshing part and to the upwardly directed arm by rotation of the pinion, and at least one stabilizer that is movable along the upwardly directed arm.

A thrust lifting device that is able to transmit a thrust force for lifting loads, includes at least one articulated lift column provided with at least one meshing part, and with at least one arm directed upward from the meshing part, the lift column made up of links with a link of rank 1 at the upper end of the upwardly directed arm and running links of rank n, where n is between 2 and N, the number of links of the lift column, at least one rotary pinion driving the lift column by the meshing part meshing with the pinion, at least one arm opposite the upwardly directed arm and formed by resting links, the resting links being able to pass to the meshing part and to the upwardly directed arm by rotation of the pinion, and at least one stabilizer that is movable along the upwardly directed arm.

The present invention is an improved apparatus and method for forming a retractable tower or column. The present invention includes pointed hooks wherein the hooks are attached to each section of a section chain, one in a horizontal direction and one in an off-set manner. The section chains are placed on a take up mechanism in an operable position and then raised utilizing a motor. As the section chains are raised, they are guided by a guide tower, rollers, shims, and gear racks into a position whereby hooks from adjacent sections of the section chains form coupled engagements. The coupled engagement of the hooks of the sections of each adjacent section chains thereby form the column.