Abstract:
In an arrangement for sliding doors, a door leaf comprises a number (n) of interlinked and jointed sections ( 4:1-4 :n) in which adjoining sections are able to rotate around a joint axis (A) from a position in which the sections are in alignment with each other to a relative angled position. The door leaf can slide in the door opening ( 6 ) in guides ( 8, 9 ), each of which comprising a first and a second interacting guide element ( 8′, 8″; 9′, 9 ″) arranged on two opposing end edges ( 22, 23 ) of the door leaf and the corresponding sides of the door opening. To obtain a sound insulating door, there is an elastically deformable material between the adjoining and relatively flexible sections ( 4:1-4 :n) to separate the sections from each other.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention concerns an arrangement for sliding doors on mobile units such as lift cages and where a door leaf comprises a plurality of interlinked and jointed sections in which adjoining sections are able to rotate around a joint axis from a position in which the sections are in alignment with each other to a relative angled position, whereby the door leaf can slide in the door opening in guides, each of which comprising a first and second interacting guide elements, the first interacting guide elements arranged on two opposing end edges of the door leaf and the second interacting guide elements arranged on corresponding sides of the door opening. 
     2. Description of the Background Art 
     Sliding doors of this type are used in a number of different applications in which the doors are usually arranged to move in the vertical or horizontal plane relative to the door opening. With regard to sliding doors on mobile units such as lift cages and similar devices, there is a particular necessity for them to exhibit sound-insulating qualities, as problems with noise, resonation vibration and structure-borne sound together with other problems are generated while the mobile unit is in motion. On lift cages with sliding doors of the type referred to, i.e. in which the door leaf principally comprises a number of interlinked and jointed sections, a large proportion of the noise is generated in the joints between the sections. This has been a problem especially on rack and pinion lifts due to the many moving mechanical parts that are used to move the lift cage along the mast. It has also become evident that the noise and vibration generated during the motion of the lift cage increases proportionally to the speed, which, as should be understood, limits the speed at which the lift can move without noise being perceived as trying by the occupants. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is therefore to achieve an arrangement on a sliding door of the aforesaid type, whereby the noise issue of such a door is essentially eliminated. In particular, the intention is to achieve sound-insulating properties of sliding doors that are arranged in mobile units such as lift cages. 
     This is achieved by the arrangement in accordance with the present invention exhibiting the distinctive features and characteristics specified in the following claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following is a description of this invention with references to attached drawings, where 
     FIG. 1 is a perspective view of a lift cage with sliding door, 
     FIG. 2 is a front view of the sliding door shown in FIG. 1, 
     FIG. 3 is a perspective view of the sliding door shown with separated parts, 
     FIG. 4 is an enlargement view of an upper guide in the sliding door in the form of a cross section along the line IV—IV in FIG. 2, 
     FIG. 5 is an enlargement view in the form of a cross section along the line V—V in FIG. 2, 
     FIG. 6 is an enlargement view of a cross section along the line VI—VI in FIG. 2, 
     FIG. 7 is a cross sectional view of the upper guide for adjoining sections included in the sliding door, 
     FIG. 8 is a cross sectional view of the lower guide for adjoining sections included in the sliding door, 
     FIG. 9 is a cross sectional view through several adjoining sections included in the sliding door, 
     FIG. 10 is a perspective view of a jointing element included in the sliding door and 
     FIG. 11 is an enlarged cross sectional view of two adjoining sections in the circle  11  of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a horizontal opening door fitted on a conventional lift cage  2  is generally designated  1 . The door leaf  3  is of louvre type, i.e. comprising several sequentially arranged vertical and interlinked jointed sections  4 , in which each section is designed as a principally rigid unit. The flexible joint between the sections is defined on the drawings as a joint axis A, around which adjoining sections  4 ,  4 ′ (FIG. 3) can rotate in relation to each other between a position in which the sections are aligned with each other and a position where they are at an angle to each other. 
     When carrying out opening and closing motions, the door leaf  3  is moved horizontally as indicated by the double-headed arrow  5 . When the door  1  is open, the door leaf  3 , as shown in FIG. 1, is moved to one side so that it principally surrounds one wall of the lift cage  2 , whereby the lift cage opening  6  is essentially completely exposed. Given that the sliding door moves outside and around one corner of the lift cage  2 , the particular use of this type of door is in areas where the door must not occupy any part of the lift cage load carrying surface  7 . Furthermore, conveying e.g. pallets and other bulky objects in and out of the lift cage is facilitated due to the ability to completely expose the door opening  6 . 
     The door leaf  3  slides in the lift cage  2  along upper and lower guide members designated  8  and  9  respectively running between the door leaf  3  and the lift cage  2 . Each guide member  8 , 9  comprises a first and a second interacting guide element  8 ′,  8 ″ and  9 ′,  9 ″ (FIG. 5) respectively, where at least one of the said guide elements comprises an elastic material. 
     As illustrated in FIG.  4  and FIG. 5, the first guide element  8 ′ of the upper guide member  8  comprises a guide rail  10  arranged on the lift cage  2  and the second guide element comprises a carriage  11  arranged at the top of the said sections  4 . The said carriage  11  comprises a mainly U-shaped supporting arm  12  with a shaft  13  having a journalled roller  14  that runs in a groove in the guide rail  10  and has an external circumference of an elastomeric material, which acts on the said guide rail. The first guide element  9 ′ of the lower guide member  9  comprises a guide rail  15  made of joined sheet with a grooved channel  16  and the second guide element  9 ″ comprises a shaft  17  having a journalled roller  18  running along the said channel  16  with a circumference of elastomeric material that acts on the inside surfaces of the grooved channel  16  in the guide rail  15 . 
     The sections  4  are manufactured of a lightweight material, which in this embodiment comprises extruded aluminum and, as illustrated in FIG. 6, the sections  4  are produced with an outer hollow part  19 , from which a number of lateral reinforcements  20  emanate. At the ends of the bottom and top edges of each section  4 , generally designated  22  and  23  respectively in FIG.  7  and FIG. 8, there are openings  21  running continuously along the length of the section. 
     Referring to FIG.  7  and FIG. 8, each such opening  21  is designed to receive a continuous means of attachment, generally designated  24 , running through the length of the section to secure a respective means of connection, generally designated  25 , to the ends of the top and bottom edges,  22  and  23  respectively, of each section  4 . Each such means of attachment  24  comprises a shaft  26  running through holes  27  arranged in the means of connection  25  and at each end is fitted with a means  28  for fastening the means of connection  25  to the ends of each edge  22 ,  33  of the section  4 . For the described embodiment of this invention, the said means of attachment  24  comprises a thread  29  and associated nut  30  on each end of a shaft  26  but could equally comprise a groove with associated retaining ring on each end of the shaft or any similar arrangement. 
     Each of the said connecting devices  25  fitted on one section  4  exhibits a cantilever  31  projecting from the section in the same direction, whereby an adjoining section  4 ′ illustrated in the figure on the right is flexibly joined between the said projecting cantilevers  31  with an attaching device  24  similar to the type described above. For the flexible joint between the said two adjoining sections  4  and  4 ′ respectively, running the length of the opening  21 ′ in the section  4 ′, there is a shaft  26 ′ that, via a bearing box  32  at the ends, is flexibly connected to both projecting cantilevers  31  running through holes  33  arranged in each of them. For the flexible joint between the sections  4  and  4 ′, the projecting cantilever  31  on the connecting device  25  has through bending been laterally displaced to a certain degree from the principal plane of the connecting device and thereby also the ends of each edge  22 ,  23  of the section  4  seen from the inside. In this way, a space is formed so that the following section  4 ′ can be accommodated and flexibly connected to the area between the said projecting cantilever  31 , as illustrated in FIG.  7  and FIG.  8 . As illustrated in FIG.  7  and FIG. 8, the connecting devices  25  will consequently be arranged in a partly overlapping and linked manner between the consecutively disposed sections  4 ,  4 ′. The joint axis A between the adjacent sections  4 ,  4 ′ is applied to one of the sections  4 ′ and runs through the same so that the second section  4  can pivot at a radial distance from the section  4 ′ around the joint axis A, which is also illustrated in FIG.  8 . 
     The bearing box  32  comprises a somewhat damping elastic material and is arranged in the vicinity of the flexible joint between the said connecting device  25  and attaching device  24  so that structure-borne sound is not conveyed to the flexible joints of adjoining sections  4 ,  4 ′. 
     The bearing box  32  comprises a first and a second part  34  and  35  respectively, where each such part is designed as a sleeve  36  with a support flange  37  made of rubber or equivalent plastic material. The sleeve-shaped part  36  is employed in a ring-shaped area defined between the connecting device  25  hole  33  and the part of the shaft  26 ′ that runs through the said hole. The sleeve-shaped part  36  thereby forms in principle a radial bearing between the connecting device  25  and the shaft  26 ′ running through the section  4 ′ and acts as an elastic damper that separates the said parts from each other in the flexible joint between the sections  4 ,  4 ′. The support flanges  36  of the first part  34  and the second part  35  form in a similar way an axial and elastic insulating bearing between the projecting cantilever  31  of the connecting device  25  and the section  4 ′. 
     It should be understood that in the same manner as described above, an adjacent third section  4 ″ is flexibly joined to the second section  4 ′ and so on to create a succession of (n) pivoting sections  4 : 1 - 4 :n forming a continuous door leaf  3 . 
     With reference to FIG. 6, jointing elements of slightly yielding elastic material generally designated  37  are fastened to the area or to the joint between each of the adjoining sections  4 ,  4 ′ and the remotely located flanking edges  38 ,  38 ′. The said jointing elements  37  are intended to achieve a relative butt joint between the sections  4 ,  4 ′ so that structure-borne sound is not conveyed between them. Jointing element  37  is also intended to act as a crush guard between the sections  4 ,  4 ′ while the door leaf  3  is in motion and to prevent snow and dust from penetrating into the lift cage  2 . The material in the jointing element  37  should be chosen so that the relative flexibility between the sections  4  is not negatively affected. For example, the jointing element  37  can be made of ethylene-propylene rubber or some other suitable thermoplastic or synthetic rubber that is easy to form and can be produced by extrusion. 
     A jointing element  37  is exemplified in FIG. 10, from which it is evident that it mainly comprises of a flat extrusion exhibiting a fluted depression generally designated  39  that is arranged along the side edges of the extrusion and two longitudinal folding notches  40  that are located in the center of the extrusion, along which the extrusion can be folded so that when mounted, it exhibits a mainly groove-shaped appearance illustrated in FIG.  11 . 
     When fitted and in cross-sectional view, the extruded jointing element  37  exhibits a first and a second partition  41  and  42  respectively that via joints generally designated  43  are connected to the side edges  38 ,  38 ′ of the adjoining sections  4 ,  4 ′. The first and second partitions  41 ,  42  are relatively connecting via a first sidewall  44  forming a transition that is in line with the outer sides  45 ,  45 ′ of the adjoining sections  4 ,  4 ′. The fluted depressions  39  running along the side edges each define a seat or a pick-up area corresponding to a protrusion  46 ,  46 ′ coming from the butting side edges  38 ,  38 ′ of the respective adjoining sections  4 ,  4 ′. The said protrusions  46 ,  46 ′ are designed to extend the outsides  47 ,  47 ′ of the adjoining sections  4 ,  4 ′ to provide, as should be understood, support and a contact surface for the adjoining sections  4 ,  4 ′ when they are in alignment. In order to prevent structure-borne sound from being conveyed between the said protrusions  46 ,  46 ′ and thereby also between adjoining sections  4 ,  4 ′, the said protrusions are contained within the fluted depressions  39  in a manner in which they are essentially surrounded and embedded. 
     The joints  43  between the first and second partitions  41 ,  42  of the jointing elements  37  and the abutting side edges  38 ,  38 ′ comprise a sharp-edged and almost arrow-like boss  48 ,  48 ′ arranged on the free end of the protrusion  46 ,  46 ′, which, in order to attain a locking action between the respective partitions  41 ,  42  of the jointing element  37  and the abutting edges  38 ,  38 ′ of the adjoining sections, interact with an undercut groove  49  that is arranged in the bottom of the fluted depression  39 . As a result of this design, the jointing element  37  can very easily be anchored to and engage a considerably locking grip in the abutting side edges  38 ,  38 ′ of the adjoining sections  4 ,  4 ′ with only hand pressure or with the use of a rubber mallet. 
     As the joint axis A is located in one of the adjoining sections  4 ,  4 ′ and the jointing element has partly a divisible sidewall formed by both the protrusions  46 ,  46 ′ and the fluted depressions  39  surrounding the said protrusions and partly a flexible sidewall  44 , it has the advantage that the adjoining sections  4  act like a hinge that can be rotated relative to each other without the jointing element  37  offering any appreciable resistance to the rotating motion. In the main, this property is achieved partly because one of the sidewalls of the jointing element  37  is divisible so that rotation is obtained only via the first sidewall  44  and partly because the first sidewall is not compressed during the actual rotating motion but is only folded along the notches  40 . This should become clear after a close study of FIG.  9  and FIG.  11 . It should also be understood that such detrimental compression of the first sidewall of the jointing element would nevertheless arise if the joint axis A were to be located on the geometrical axis between the sections  4  and  4 ′, i.e. principally half way between the adjoining sections. 
     The present invention is not limited to the above description or as illustrated in the drawings but can be changed and modified in a number of different ways within the framework of the idea of invention specified in the following claims.