Patent Publication Number: US-6708448-B2

Title: Drive unit for doors, especially elevator doors having a non-rectilinear profile

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drive unit for doors, especially doors having a non-rectilinear profile. 
     More particularly, the present invention relates to a drive unit for elevator doors having a semicircular profile. 
     2. Description of Related Art 
     As is known, elevator systems comprise cars of various type, mainly of parallelepiped form with a square or quadrangular plan. In these cases, the doors that close the car room slide rectilinearly along special guides. 
     Circular plan cars are also common in civil and commercial buildings, and are utilized both for elevators and to create access zones to buildings such as, for instance, banks, hotels and public facilities. 
     Obviously, the doors of these cars have a profile that is not rectilinear but semicircular or, more precisely, circle-arch shaped. The cars of this type have severe drawbacks as concerns the opening and closing movements of the related doors. In fact, the motor units must comprise connections able to transform the rectilinear motion into a motion developed along circle-arches parallel to the profile of the car. 
     The traditional solutions adopted to this aim are extremely complicated from both the construction and the functional aspects, because of the presence of a high number of components, such as, for instance, articulated arms, tie-rods and transmissions. 
     As a consequence, also maintenance and repair operations of the apparatus intended for door movement are exacting, difficult and sometimes critical. 
     A further drawback which is found in circular plan cars is associated to the big size and weight of the drive unit of the door, independently on whether it is located on the roof or the base of the car. 
     There are, in fact, necessary specific reinforcement and supporting structures that concur to further complicate the construction and the assembly of the system. 
     The presence of many linkages and transmissions gives also rise to a high friction between the moving parts, requiring the use of high power motive units, with an ensuing increase in energy consumption. 
     BRIEF SUMMARY OF THE INVENTION 
     Object of the present invention is to obviate the above drawbacks. 
     More particularly, object of the present invention is to provide a drive unit for doors having a non rectilinear profile, in particular and especially elevator doors with a circular plan such as not to require the use of many elements interconnected with each other to cause such movement. 
     A further object of the invention is to provide a drive unit as defined above, extremely compact, of a limited weight and suitable to be connected in a quick and easy manner to the roof or the base of the car. 
     A further object of the present invention is to provide a movement group that does not involve maintenance interventions. 
     A further object of the invention is to provide a drive unit wherein the friction between the components is extremely reduced. 
     A further object of the invention is to provide a drive unit for doors having a rectilinear profile, suitable to ensure a high level of resistance and reliability in the time, and also such as to be easily and economically realized. 
     These and still other objects are achieved by the drive unit for doors having a non-rectilinear profile, in particular for doors of circular plan elevator cars, constituted of aligned or telescopically moving superposed wings, characterized basically in that it comprises a motor provided with a shaft that rotates in alternate clockwise and anti-clockwise direction, and at least a bar or section connected to at least one of the wings and that engages with said shaft. 
     Said drive unit may be located on the roof or the lower base or between the wings of the elevator cars of story doors. 
     In the case of doors constituted of telescopic movement superposed wings, the bar or section is connected to one only of the wings, and a transmission unit transmits the rotation of said wing to the other wing of the door. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The constructive and functional characteristic of the drive unit for doors having a non rectilinear profile of the present invention will be better understood thanks to the following description wherein reference is made to the attached drawings which represent some preferred embodiments by way of non limiting examples and wherein: 
     FIG. 1 shows the schematic top view of a part of a circular plan car in closing position and with the door wings aligned, provided with the unit of the present invention. 
     FIG. 2 shows the schematic top view of the same part of car of FIG. 1, in opening position. 
     FIG. 3 shows the schematic top view of a circular plan car with superposed or telescopic wings, provided with a transmission group, also an object of the present invention; and 
     FIG. 4 shows the schematic top view of a circular plan car with superposed or telescopic wings, provided with a transmission group, and positioned on the cabin roof of an elevator. 
     In the description which follows the expression “bars”, “sections” and “racks” are interchangeable with each other, and the words “pulley”, “serrated pulley”, “toothed pinion gear” and “serrated pinion gear” are also interchangeable with each other. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 and 2 show by way of example a car solution with automatic central opening aligned doors, both as concerns the internal or car wings, indicated by  24 ,  24 ′, and as concerns the external or story ones, indicated by  26 ,  26 ′. 
     With reference to said FIGS. 1 and 2, the drive unit for doors having a non rectilinear profiles of the present invention basically comprises a motor  10 , provided with a rotation shaft  20 , and a couple of curved bars or sections. i.e., racks,  12 , 14 , developed in the shape of a circle-arch, located on the opposite sides of said shaft  20 . Motor  10  may advantageously be an asynchronous or synchronous electric motor or of another known type and may be supported by a conventional plate-like support  16  integral with roof  18  of the elevator car. Shaft  20  of motor  10  protrudes with an orientation that is preferably orthogonal with respect to the surface formed by roof  18 . 
     Said shaft  20  might also be parallel to roof  18 . A preferably serrated pulley  22 , i.e., toothed or serrated pinion gear  22 , is fixed to shaft  20 . Bars or sections  12 ,  14  are curved according to a predetermined radius that corresponds to a circumference concentric with the circular profile of the elevator car. In particular, said sections  12 ,  14  develop in such a manner as to be substantially parallel on each point to the internal wings  24 ,  24 ′ and external wings  26 ,  26 ′ that form the car doors. Motor  10 , through the related support  16 , is advantageously fixed to roof  18  of the elevator car in a position close to said internal wings  24 , 24 ′ and external wings  26 , 26 ′, so that its shaft  20  is aligned with one of the car axes, i.e. along vertical A that corresponds substantially to the approach line of the internal wings  24 ,  24 ′ and of the external wings  26 ,  26 ′, in closing condition. Bars or sealons  12 ,  14  systematically strike diametrically opposed points of pulley  22 , being respectively positioned, with respect to said wings  24 , 24 ′, 26 , 26 ′, before or behind said pulley  22 , and preferably on different plans or levels. 
     Pulley  22  strikes and engages with sections  12 ,  14 , starting from their inner sides, that are facing and opposing each other. The external sides of said sections  12 ,  14  strike, on the contrary, guide means that may be two or more idle wheels or rollers  28 ,  30 , protruding from the plate-like support  16  of motor  10 . According to a preferred embodiment, the internal side of sections  12 ,  14  that strike pulley  22  are provided with indentations  12 ′,  14 ′, complementary to that of pulley  22 . The latter ensures the constant engagement between the components during the movement, and the absence of possible slippings that would lead to asynchronies in the control of wings  24 ,  24 ′,  26 ,  26 ′ when the latter are opening or closing. Indentation  12 ′,  14 ′ on sections  12 ,  14  can be obtained by treating mechanically said sections or formed on an added element, obtained for instance from rubber or plastic material. On the other hand, it is not excluded the possibility that the engagement between pulley  22  and sections  12 ,  14  realizes also in the absence of indentations, as said components, or for instance only the pulley, can be periodically provided with a surface finishing or a rough covering or in any case a covering suitable to create a mechanical interference. A rubber covering on the sides of sections  12 ,  14  and/or the lateral surface of pulley  22  may be the proper solution for this purpose. 
     Motor  10 , whose shaft  20  rotates alternatively in clockwise or anti-clockwise direction, causes the sliding of sections  12 ,  14  along circle-arches parallel to the circular profile of wings  24 ,  24 ′ and  26 ,  26 ′. 
     Wings  24 ,  24 ′ and  26 ,  26 ′ slide in opening and closing orientation along conventional sliding sills or tracks, one of which  32  is internal for the internal wings  24 ,  24 ′, and one external for the external wings  26 ,  26 ′. Wings  24 ,  24 ′ and  26 ,  26 ′ are connected with the respective sections  12 ,  14  by means of arms or tie-rods  36 ,  38 . 
     In particular, each tie-rod  36 ,  38  is connected through known means to the external end of each section  12 ,  14 . Tie-rods  36 ,  38  develop in the direction of said wings  24 ,  24 ′,  26 ,  26 ′ according to a substantially orthogonal orientation, striking them in a position close to the respective edges that approach to each other during the closing step. In case of an elevator provided with simultaneously moved car wings  24 ,  24 ′ and story cars  26 ,  26 ′, as shown in FIGS. 1 and 2, arms or tie-rods  36 ,  38  strike the first and innermost car wings  24 ,  24 ′ and extends to reach the second and outermost story wing  26 ,  26 . The connection between said tie-rods  36 ,  38  and wings  24 ,  24 ′,  26 ,  26 ′ is obtained through washers  40  or like connection means. 
     During the running stage, the drive unit of the present invention determines the alternated sliding in opposite directions of sections  12 ,  14 , following the activation of motor  10  whose pulley  22  is engaged along the internal side of said sections. During the alternate sliding, said sections  12 ,  14  that are connected through tie-rod  36 ,  38  to wings  24 ,  24 ′ and  26 ,  26 ′, move said wings causing their moving away from, or approaching to, each other, sliding along guides  32 ,  34 . Sections  12 ,  14 , in their turn, are guided and kept in position by the idle wheels or rollers  28 ,  30 , protruding from support  16  of motor  10 . 
     FIG. 3 shows, by way of non limiting example, the application of the feeding unit of the present invention to an elevator having a semicircular profile with superposed wings that have a telescopic movement with respect to each other, with an automatic lateral opening of the internal  124  and the external  126  wings of a part of the elevator door. 
     FIG. 3 shows only a part of the elevator formed by two wings  124 ,  126  superposed according to a telescopic movement. The door comprises also two other wings, symmetrical with respect to each other, not shown in the figure. 
     The drive unit of the present invention provides to moving the internal wings  124 , as described above. Said internal wings  124 , in fact, are connected to the related sections  12 ,  14  through arms or tie-rods  36 ,  38 . Sections  36 , 38  are moved by motor  10  through pulley  22  that engages along the internal side of the same, as described above in detail. 
     For the telescopic movement of internal  124  and external wing  126 , a transmission unit  100  is provided, which is also object of the present invention. 
     With reference to FIG. 3, the transmission unit  100  comprises a second serrated idle pulley  110 , pivoted on a shaft  120 , and a couple of curved bars or sections  112 ,  114 , located on the two opposite sides of said idle pulley  110 . 
     Shaft  120  is fixed to the internal wing  124 , in correspondence of its front end with respect to the opening of the elevator doors. Bars or sections  112 ,  114  are curved according to a circumference concentric with the circular profile of the elevator car. In particular, said sections or bars  112 ,  114  are substantially parallel both to wings  124 ,  126 , and the fixed part of the car or structure  122  of story doors. 
     Bars or sections  112 ,  114  are fixed respectively to the fixed structure  122  and the external wing  126 , and are so arranged as to strike the idle pulley  110  on opposite sides. 
     In order to ensure the constant engagement between the idle pulley  110  and the bars or sections  112 ,  114  during the movement, and to prevent a possible sliding, the internal sides of sections  112 ,  114 , which strike pulley  110 , are preferably provided with a complementary indentation  112 ′,  114 ′ that engages with the one of the idle pulley  110 . 
     Identifications  112 ′, 114 ′ may be obtained with mechanical operations directly on sections  112 , 114 , or they may be obtained on a separate element, for instance from rubber or plastic material, and fixed to said sections  112 ,  114 . Alternatively, there may be used any means able to ensure the dragging of bars or sections  112 ,  114  by the idle pulley  110 , without sliding. 
     Thanks to the movement of the internal wing  124 , caused by motor  10 , pulley  110  rotates alternatively in clockwise and anti-clockwise direction, engaging with indentation  112 ′ of section  112 , fixed to the fixed structure  122 . During the rotation, pulley  110  engages with indentation  114 ′ of section  114 ′, fixed to the external wing  126  and causes the simultaneous sliding of the external wing  126  with respect to the internal one  124 . In particular, if the internal wing  124  slides at a velocity (V 1 ) caused by the angular velocity of pulley  22  of motor  10 , the external wing  126  slides at twice said velocity (V 2 =2V 1 ). 
     In the running stage, the alternate closing and opening movement of the internal wing  124 , caused by motor  10 , causes the rotation of the idle pulley  110  that engages with section  112  fixed on the fixed structure  122 . The rotation of pulley  110  induces a simultaneous alternate closing and opening movement of the external wing  126 , in the same direction as the movement of the internal wings  124 , to engage pulley  110  on section  114  fixed to the external wing  126 . 
     As can be inferred from the above, the advantages achieved by the invention are evident. 
     The drive unit for doors having a non rectilinear profile of the present invention has an extremely simple structure formed by a low number of components directly connected to each other. The size and weight of the drive unit are very reduced and, in the absence of joints and transmissions, the assembly of the whole is simple and immediate. Given this advantageous structure, no particular and regular maintenance intervention are needed. Besides, the friction is substantially limited and therefore low power motors with reduced energy consumption may be utilized. While the present invention has been described above with reference to some embodiments thereof reported by way of non limiting example, many modifications and variants may be introduced by those skilled in the art, in the light of the above description. 
     For instance, the drive unit may be utilized for elevators provided only with automatic movement internal wings or one only lateral opening wing; in the latter case, there will be utilized only two rollers  28  or  30 , associated with pulley  22  and a section  14  or  14 ′. 
     The drive unit of the present invention may also be connected to the lower base of the elevator car instead of the roof. 
     Motor  10 , which in the figures is shown in a position orthogonal to the roof of car  18 , may be positioned parallel to said car roof  18 . 
     Besides, while being especially suited for the application to elevator doors or entry doors having a non rectilinear profile, the drive unit of the present invention may be utilized for traditional rectilinear profile doors, in which case sections  12  and/or  14  having a linear development will be used. 
     Referring to FIG. 4, motor  210  constructed in accordance with the invention is shown on the cabin roof  212  of an elevator. 
     The present invention intends to comprise all the modifications and variants that fall within the protection scope of the following claims.