Patent Publication Number: US-2011053136-A1

Title: Turntable for support of loaded surfaces

Description:
Subject of this invention is a turntable for vertical support of loaded horizontal surfaces, that has an upper and a lower half, between which it includes a vertical rotatable guiding element. 
     In many cases there is a demand for rotating an object on a horizontal supporting surface so that rotation is to be slow and long-lasting, but application of any external energy sources is not required. Using electrical tools the rotation can be accomplished with any speed and within any duration, but supply or storing of electric energy is costly, requiring maintenance, and the engines themselves are very sensitive to environmental effects. 
     Target of our invention is to satisfy the above demand by a simple, reliable and cheap to manufacture mechanism—a turntable—that does not require any electric or other energy from external sources, thereby it is environment-friendly and economic. 
     We have recognised that mechanic work performed along a small movement path evoked by gravity can be transformed to rotation so that this is performed in prolonged time interval, while make-up of energy—that is movement along the path in reverse direction—is performed faster. Pendulum-clocks work on such a principle, but there slow movement of weights causes alternating motion. Our recognition is application of a similar principle for production of rotational motion. The invention is a corresponding mechanism consisting of two halves. 
     The turntable according to the introductory paragraph in its most general form is such that within the guiding element a braking element is arranged that limits vertical downward movement of the loaded horizontal surface to a given speed. The guiding element includes a threaded part that converts vertical downward movement into rotational motion, where the upper half during his downward movement engaged into the threaded part, through it is connected to the lower part by mechanical coupling for rotation transfer. The braking element is configured so that—after expiration of loaded condition—it allows backward movement of the upper half relatively to the lower part practically without or with light braking, and during its downward movement the upper half is coupled to the lower part without mechanical coupling for rotation transfer. 
    
    
     
       Further the invention will be presented by drawings, where 
         FIG. 1  is a sectional view of the turntable according to the invention, 
         FIG. 2A  is the enlarged braking element outlined by a sphere on  FIG. 1 , in a section showing upward motion, 
         FIG. 2B  is the enlarged braking element outlined by a sphere on  FIG. 1 , in a section showing downward motion, 
         FIG. 3  is a design that is configured with an adhesive surface and that has a coupling intermediate element, in section, and 
         FIG. 4  is a design according to  FIG. 3  in which there is an external regulating element. 
     
    
    
     In  FIG. 1  a turntable according to the invention is shown, which serves for vertical support of a practically horizontal surface. The turntable consists of two parts, of an upper half  1  and a lower half  2  with a guiding element  3  between them that includes a threaded part  4  of fixed position relatively to the lower part  2 . This threaded part  4  is a thread with high pitch with one or more starts established in the internal cavity  5  and in the inserted envelope of the upper part of the guiding element  3  as well as the connecting complementing formation. Such a complementary formation can be e.g. a full thread or only one or more protrusions from the cylindrical shell surface of the cavity  5 . The essence is that in case of a force directing downwards and acting onto the upper half  1  the formation engaged into the threaded part  4 , and through this establishes a mechanical coupling to the lower part  4 . When it is in the condition loaded by the previous weight, under the effect of the downward pressing force the threaded part  4  with high pitch will move downward so that in the meantime rotates. We must regard to both movements—lowering and turning—as a relative displacement between the upper half  1  and the lower half  2 . According to the invention, however, the task is that rotation under this gravity is performed slowly, and we can regulate even this slow speed. Our further target is that return to initial position—differently from the previous—is performed fast and without rotation. To achieve this double target, on the one hand we must establish in the guiding element  3  a braking element  6  that causes some braking of various extent against vertical movement between the lower half  1  and the upper half  2  depending on the direction. When these are approaching, the braking is large and dampens the motion to extremely slow. When they are moving away, the braking is minimal, almost zero. To accomplish this, on the exemplary design of  FIG. 1 , on the lower part of the guiding element  3  we show a mechanism with a piston  7  and a non-return valve  8 , enlarged in  FIG. 2A . In the cylinder  9  of the guiding element  3  a piston  7  is placed that air tightly seals the lower volume of the cylinder  9 . Air closed here can flow outward or inward only through a valve  8 . When the upper half  1  and thereby the piston arm  10  is reached and moved by a force that acts upward then the  11  sealing of the valve  8  opens, and the air can flow through bores  12 ,  13  along the arrow almost unobstructed into the lower closed room of the cylinder  9 . This condition—that can be established by a returning element, e.g. a spring, but manual operation can also be imagined—is shown in  FIG. 2A . In case of a movement in reverse direction, closed air according to  FIG. 2B  forced to flow outward as a result of volume decrease. This flow, however, enforces the sealing  11  to close the bore  12 . Between the sealing  11  and the inner wall of the valve  8 , at their contact surface we may use such solution that impairs hermetic closing, thereby allowing some low flow. This can be achieved by making the contacting surfaces roughened, abrasive or by forming at least on one of them small-sized grooves, channels, chamfers. Air diffusion ability of artificial diffusing structure worked out in such a way in contacting surfaces can be regulated. For this, previously known solutions exist and are well applicable. Alternatively, however, instead we may prepare in the piston  7  a small-sized air diffusion opening  14 , e.g. a bore, which has a minimal role in the position according to  FIG. 2A  when the valve  8  is open, but when according to  FIG. 2B  the valve  8  is closed—and now we assume perfect closure—then flow-out from the closed room can be performed only through this opening  14 . We can adjust the damped speed of the downward movement by the size of the opening  14  or by the total size of several openings  14 . Such a design, in which we establish several small openings  14  in the piston  7 , and we adjust the braking rate of the braking element  6  so that we close some of these openings  14  and release several of them. The less free openings  14  exist, the higher is damping, i.e. the slower is the achieved rotation. In the piston  7  of the braking element  6  therefore one or more passing openings  14  determine the minimum speed of diffusion of the medium based on the two directions. 
     We can adjust the speed of the movement by the size of the openings  14  only as fixed. If, however, instead of borings we insert—between the lower and upper part of the cylinder  9  divided into two parts by the piston  7 —a regulating element  18  that is easily adjustable by the user then by changing the diffusing section of the regulating element the speed—and thereby the duration of lowering—becomes easily controllable. This solution is shown in  FIG. 4 . Here therefore we place the regulating element  19  protruding into the closed room part, in the cylinder  9  of the piston  7 , so that by the regulable speed of diffusion of the medium we change the speed of lowering movement of the upper half  2 . At a piston  7  moving in air medium, the other end of the regulating element  19  can be opened also into the open space. Element corresponding to the regulating element  19 —e.g. regulable valve—is a commonly known element which is easy to manufacture. 
     Our further object—establishment of a rotating motion during downwards movement and escaping it in reverse order—can be accomplished in several ways. One opportunity is a mechanism that engages into the threaded part  4  depending on the direction. For this, there are a number of known solutions. For this, on one of the lower half  2  and upper half  1  the threaded part  4 , while on the other half the engaging mechanism is found. This part of the lower part  2  and upper part  1  practically forms concentric circles, among which the engaging mechanism constitutes the connection, but only in one direction. Formations that contact with the threaded part  4  and that are formed on the other half can be e.g. protrusions that engage into the threaded part  4 . The engaging mechanism can be accomplished with these protrusions or with other similar engaging springy mechanism by a tool fixed on the thread of high pitch. 
     Another possible design form is shown in  FIG. 3  where a part of the guiding element  3  is an intermediate element  15 , which—as a screw nut mechanism—is in constant connection with the threaded part  4 . Downward movement of this intermediate element  15  is limited by the braking element  6 . Upper horizontal surface of the intermediate element  15 —as adhesive coupling—engages on the internal lower surface  16  of the cavity  5  formed for the upper half  1 . This adhesive coupling-like engagement, however, will proceed only when a downward force is effected onto the upper half  1 , therefore this presses it with the intermediate element  15 . When e.g. manually or by other way we move the upper half  1  then the rotation-transferring connection established with the intermediate element  15  is broken, and the intermediate element  15  and can turn independently from the upper half  1  in the internal cavity  5  of the upper half  1 , to which the lower retaining edge  17  does not transfer the rotation, it just prevents outfall of the intermediate element  15  from the upper half. 
     According to an expedient design, that can be seen e.g. in  FIGS. 3 and 4 , for the braking element  6  and thereby for the upper half  1  that moves together with it, the turntable includes a returning element that in case of expiration of the loaded condition moves the braking element  6  into its upper position. The returning element expediently is a spring  18  that is supported on the lower part of the cylinder  8  and returns the piston  7  to its upper position when the load originated from gravity and exceeding the spring force expires. Instead of a returning element, or for its supplementation, manual operation can be applied additionally when we simply draw up the upper half  1 . 
     Rotation of the piston  7  would lead to superfluous wear, therefore during its upward and downward movement it is expedient to avoid that. For this, between the piston  7  and the piston arm  10  or between the intermediate element  15  and the piston arm  10  a component decreasing friction—e.g. a bearing—can be placed. 
     We will describe the operation of the turntable according to the example in  FIG. 3 . When an object or person of sufficiently large weight is put onto the practically horizontal upper surface of the upper half  1  then it presses down that by the force F. As a result of this, the intermediate element  15  that engages into the threaded part  4  of high pitch will move downward through its full or partial inside threading, while it will turn to the rotation direction q, too. In the meantime the intermediate element  15  establishes an adhesive connection on the surface  16  of the cavity  5  according to the principle of known clutch disks, and it rotates the upper half  1  relatively to the lower part  2 . Meanwhile the speed of lowering of the upper half  1 , of the intermediate element  15  is determined by the braking element  6 . This allows pressing-out of a given small amount of air (or liquid) due to proper valve configuration for every time unit. This limits downward movement of the piston  7 , which also presses the spring  18 . Movement of the piston  7  is transmitted to the upper half  1  via the piston arm  10  through the opening of the intermediate element  15 . When the downward movement reaches the lower possible end position or the force F disappears earlier then the spring  18  moves the piston  7  upward, which due to the valve practically unobstructed can advance upward. Then on the surface  16  in for fail of the pressing force no adhesion is created, that is the upper half  1  advances forward without rotation, however the intermediate element  15 , for which remaining in the cavity  5  is provided by the edge  17 , will rotate again on the threaded part  4 , while advancing upward. 
     Beside the described embodiments, we may also apply additional solutions to achieve braking as well as engagement to the threaded part  4  depending on the direction. Generally our target is that possible theoretical speed of loaded downward movement and unloaded upward movement—where the latter can be performed manually or with sprung return—is very different, and in most cases we wish to specify only the speed of downward movement and through the threaded part  4  thereby the speed of rotation, and returning is performed practically unobstructed, the speed or time (if it is short) of which is not important. 
     In the shown exemplary implementations of the braking element  6  we applied air in the space delimited by the piston  7  and the cylinder  9 , but we can use liquid, too. In this case the spring effect caused by the gaseous medium falls out, and as a result of incompressibility of liquids we get a device of harder operation. 
     The turntable according to the invention practically serves for vertical support of horizontal surfaces and this opens various areas for application. The solution has an important advantage that no energy supply is required. Such application area can be, for example, establishment of such sunbath bed that rotates at a predetermined speed and thereby the person lying on it is turned towards the sunshine. This makes sun-tan more uniform and reduces the risk of concentrated burning of the skin. Of course, rotation speed must be adjusted so that the turnaround takes several minutes or several decades of minutes. The speed of rotation must be so low that the user does not detect it, as fast rotation can be disturbing, and may cause even dizziness, for example. For complete exclusion of risks of accidents, it is expedient to reduce also the speed of upward movement and to make the diffusing borings by observing this. With the described valve- and piston solutions, such a braking element  6  can be accomplished. 
     Further application areas for the turntable can be its configuration as a warehouse- or exhibition tool for product fairs. 
     Similarly to the previous way, we can make a maintenance-free moving advertisement tool without the need for energy supply, which requires seldom restarting only, but this may cover even a long period. Energy-free usage of the turntable according to the invention is especially advantageous in such areas (e.g. on open air) where it cannot or can be provided only in a costly way. 
     The turntable can be applied as a school training or demonstration tool that shows an object or phenomenon from its several sides for many people. 
     As a turntable, it can be configured for entertainment purposes in restaurants, at drawing-rooms, on programs. 
     For some mounting and working tasks, where traditionally e.g. conveyor belt can be applied, by using the turntable according to the invention, workpieces or components can be forwarded among workplaces arranged along a circle, saving energy 
     In bigger sizes the turntable according to the invention may be suitable also for moving of theatrical sceneries or stages. 
     In general, the invention is suitable for all such tasks where one or more objects must be made available or visible from different directions without additional source of energy, and this operation can be repeated after expiry of a given time interval by human intervention. The part of the turntable that establishes rotation, the guiding element can be prepared also in small size, and for this the necessary base and upper supporting surfaces, components can be inserted separately, thereby they can be easily assembled and disassembled and transported. Place of utilisation does not require any ground- or other preparation. 
     PARTS LIST 
     
         
         
           
               1  upper half 
               2  lower half 
               3  guiding element 
               4  threaded part 
               5  cavity 
               6  braking element 
               7  piston 
               8  valve 
               9  cylinder 
               10  piston arm 
               11  sealing 
               12  boring 
               13  boring 
               14  opening 
               15  intermediate element 
               16  surface 
               17  edge 
               18  spring 
               19  regulating element