Telescopic screw lift, especially for lifting a flat TV screen from the furniture container into a display position

The subject of the invention is the telescopic screw lift, used especially for installation in the furniture container for lifting flat large-size TV screen from the furniture container into a display position.

There are known telescopic lifts, which have a dual-screw lifting assembly, built into the three-modular telescopic column. In standard version, the lifting assembly has a spindle drive screw coupled on one end via gears with the motor, with the threaded part driven into a sleeve screw. The sleeve screw with external thread is engaged with the nut of the telescopic column actuator.

There are also known other lift designs, for example, from documents EP 0247578, DE 10018742, DE 19711773 and FR 2625488, which have two sleeve screws, of which one driven by the motor is driven into the other sleeve screw, and the latter is screwed onto the spindle screw, rigidly seated in the telescopic column module. Independently from the construction of the screw lifting assembly the actuator and the central module of the telescopic column move coaxially and along the fixed external module on sliding cylindrical guides. Cylindrical guides when engaged with the screw mechanism must be secured from rotating, which is achieved by using keyway joints.

A very fast development of electronics taking place over the last years has resulted in launching large-size, flat audio-video equipment, especially flat TV sets, panel LCD monitors, plasma displays - which require new equipment, adapted for work in the environment. Often displays are installed inside the furniture, from which they are pulled out periodically into display position. For this purpose mechanically driven, vertical screw lifts are most commonly used.

For instance, the device presented in US 2004/0090149 has two, vertical guide screws, seated in bearings on the display sides, driving the horizontal load- bearing plate, on which the display is fitted via spherical pivot. Lower ends of the screws are driven by electric motor via cogbelts. In the upper position the spherical pivot projects above the furniture box so that when the clamp on the pivot is released the display can be manually positioned to ensure best watching position. Before lowering the display into the furniture container it must be always positioned in the vertical null plane. Failure to do so can result in damage of the expensive equipment.

The kinematical system, similar to the one described above, has a unit presented in WO 01/95763. Units presented in US 2005/0057129 and US 2002/0101139 have one central drive screw and two guides, symmetrically located on both sides of the screw. The lowest height of the furniture container with the enclosed TV set is ensured by the constructional system for which the lift is located behind the display, provided this is a telescopic lift.

The telescopic lift as described herein has, similarly as in the described designs, dual-screw lifting assembly installed inside the three-modular telescopic column. The essence of the design refers to a special construction of the telescopic column, in which the cross-section of the walls of the external and central module is in the form of regular polygonal geometric figures, similar to each other and the actuator is similar to them in shape or is round. Module guides are made up of linear double-row, ball bearings, mounted on axes of symmetry of module cross-sections and accordingly external and internal raceway strip to the neighboring wall surfaces.

Running the modules on linear rolling bearings, in the position with spatial layout of the side walls of the prism with a base of the regular geometric figure, ensures not only quiet, low-friction operation of the mechanism, eliminating possible relative rotation of the modules but also greater resistance of the construction to loads from side forces in the pulled out position.

It is advantageous, if the corners of the modules are truncated symmetrically, which minimizes the outline radius of the columns in the cross-section. It is also advantageous when the lift is fixed with elements located in the plane of the rear side of the external module.

Good cooperation of the threaded connections of the lifting assembly is achieved when the sleeve screw is made of plastic, and the drive screw and actuator nut are made of steel. With this embodiment it is purposeful to use a lower end sleeve screw with the internal thread provided with a reinforcing ring, seated on the external surface of the sleeve screw.

Positioning of the subject in the horizontal plane is ensured when the subject bracket is pivot mounted on a pivot coaxially seated on the upper end of the actuator, and additionally, when the bracket is equipped with electric motor coupled via slip-free gear with the actuator. In this version the bracket has a horizontal hanger beam, to which along one side a vertical support frame is connected, run downwards with a small slot from the radial outline of the external module and equipped with arms securing a flat object, particularly TV display.

The lift described herein is characterized by very quiet, vibration-free operation of the mechanisms - which is particularly important when used in habitats. Also remote control of the lifting movement and positioning of the object makes it particularly valuable feature when lifting large TV displays from furniture containers.

The invention is illustrated by the description of the example of lift embodiment, with the bracket adapted for eccentric side fastening of flat TV screen. Fig. 1 shows vertical section of the lift in lower position, fig. 2 shows telescopic column cross-section according to the A-A line marked on fig. 1 , fig. 3 and fig. 4 show cross sections for other column versions, with square and triangular forms of the modules, fig. 5 shows vertical section of the lift in upper position, and top view for directional leaning of the screen is presented on fig. 6

The lift has dual-screw lifting assembly A installed inside the three-modular telescopic column B. The telescopic column B is secured to the vertical wall of the furniture container 21 using fastening elements 13 rigidly connected to the rear wall of the external module 7.

Lifting assembly A has spindle drive screw 1 , and its bottom end is connected via gear 6 with electric motor 5. Drive screw 1 is driven into threaded hole of sleeve screw 2, and its external thread engages with nut 4 seated on the bottom end of actuator 9 of telescopic column B. Sleeve screw 2 is made of polyamide plastic and drive screw 1 and nut 4 of actuator 9 are made from steel. The area of threaded hole, at the bottom end of sleeve screw 2 is embraced from outside by reinforcing ring 3.

Telescopic column B consists of three coaxially driven modules: external 7, central 8 and actuator 9. Walls of external module 7 and central module 8 in the cross-section are of regular octagon shape, and actuator 9 is made of a pipe. Guides of modules 7, 8, 9 are made up of linear dual ball bearings 10, mounted on axes of symmetry of their cross sections using screws or by welding the rails of external raceway 11 and internal raceway 12 to the walls of neighboring modules 9, 8 and 8, 7. In this version the perpendicular layout of planes of opposite linear bearings 10 is at 45° to the fastening plane, to the rear wall of furniture container 21. Corners of external 7 and central 8 module are symmetrically truncated, which also allows to achieve the perpendicular layout. Fig. 3 shows the version with telescopic column B provided with all modules 7, 8, and 9 with square section, and fig.4 shows the version, in which walls of external 7 and central 8 module have triangular cross-section and symmetrically truncated corners while actuator 9 is round.

Bracket C in version provided for securing flat, large-size objects 20 - such as plasma TV screen, has horizontal hanger beam 17 to which along one side vertical support frame 18 running downwards is connected.

Support frame 18 is deflected from the lift axis to form a small slot s between outlines of frame 18 and external module 7. It is equipped with horizontal arms

19 for securing TV screen. Hanger beam 17 is mounted on pivot 14 seated in the sleeve mounted on the upper end of actuator 9. Bracket C is connected with electric motor 15 coupled via slip-free gear 16 - in this embodiment toothed gear - with actuator 9, which allows to remotely control the angle α, and position the screen axis towards the spectator. Operation of electric motor 15 is only possible when the TV set is positioned higher than the level of furniture container walls 21 , which protects the control system. Positioning of TV set 20 covers full range of angle α=360° Parameters of TV set position 20: lifting height and angle α, characteristic for specific configuration of the rooms and particular point of watching are stored in the memory block of the control system - and can be called and executed.