Abstract:
The present invention concerns a lamp ( 1 ) having a number of plates ( 3, 4, 5 ). The plates ( 3, 4, 5 ) are moveable between a position where the plates ( 3, 4, 5 ) form a common outer surface and a position where the plates ( 3, 4, 5 ) are separated from each other. By means of the plates the shape and appearance of the lamp ( 1 ) may be amended between having the form of for instance a closed sphere and a more or less open form. The plates ( 3, 4, 5 ) are placed on upper and lower curved arms ( 17, 26 ). The curved arms ( 17, 26 ) are connected to an upper ring ( 10 ) and a lower ring ( 9 ). The curved arms ( 17, 26 ) are moved by movement of the lower ring ( 9 ) towards and away from the upper ring ( 10 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention concerns a lamp, especially a ceiling lamp. 
       BACKGROUND 
       [0002]    The desired light pattern of a lamp may vary depending on a number of reasons. It may be that one sometimes wants a more dampened light and sometimes a more powerful light. It may also be that one wants to alter the light distribution. One way to alter the light distribution is to amend the shape of the lamp shade. 
       SUMMARY 
       [0003]    An object of the present invention is to provide means making it relatively easy to alter the shape of a lamp or lamp shade. 
         [0004]    The shape and appearance of the lamp or lamp shade of the present invention may be amended between having a relatively closed form and a more or less open form. The lamp has a number of plates, which are placed adjacent each other in the closed form. The plates may be separated from each other to reach the more or less open form indicated above. The plates could be made in any desired material. In the present example the plates are made of an opaque material, having a reflective inner surface. Thereby when the lamp has the position of being in a closed form it will only give a spread weak light. In said closed position the lamp could be said to have only a decorative function. When the lamp is opened up the light will reflect on the inner surfaces of the plates giving a light distribution depending on how much the lamp has been opened. Thus, the position of the plates may be used as a way of amending the light distribution. 
         [0005]    The closed form may be any desired form, such as a ball shape, egg shape, pear shape, a cubic shape and also shapes having at least partially straight surfaces. The different forms are given by suitable design of the plates and arms by which the plates may be moved. Thus, even though the closed position is described below and shown in the drawings as a sphere for convenience, it is to be understood that it may have any form. 
         [0006]    The plates are placed on curved link arms. The other ends of the link arms are received alternately on a lower ring and an upper ring. The upper ring is placed at a distance straight above the lower ring. The lower ring is arranged moveable towards and away from the upper ring. 
         [0007]    By using several identical elements placed in different positions the costs of manufacture, storing and transport may be kept relatively low. 
         [0008]    As used in this description the expressions “upper”, “lower” and similar expressions are in relation to a ceiling lamp as pendent from a ceiling. As used in the description below the lamp has two end positions, one closed position when a sphere is formed and an open position when the plates have made a maximal movement from said closed position. 
         [0009]    Further objects and advantages of the present invention will be obvious for a person skilled in the art reading the detailed description below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The invention will be described further below by way of an example and with reference to the enclosed drawings. In the drawings, 
           [0011]      FIG. 1  is a side view of a lamp according to the present invention in a first, closed position; 
           [0012]      FIG. 2  is a side view of the lamp of  FIG. 1  in a second, open position; 
           [0013]      FIG. 3  is a side view of the lamp in a position between the closed and open positions of  FIGS. 1 and 2 , respectively, 
           [0014]      FIG. 4  is a perspective view of details of the lamp of previous Figs.; 
           [0015]      FIG. 5  is a side view corresponding to  FIG. 4 ; 
           [0016]      FIG. 6  is a perspective view of the details of  FIG. 4  in another position; 
           [0017]      FIG. 7  is a side view corresponding to  FIG. 6 ; 
           [0018]      FIG. 8  is an enlarged view of a part of the details of  FIGS. 4-7 ; 
           [0019]      FIG. 9  is a perspective view of details of the lamp of previous Figs.; 
           [0020]      FIG. 10  is a perspective vies of details of the lamp of previous Figs; and 
           [0021]      FIG. 11  is a plan view illustrating one example of a locking device. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    A ceiling lamp  1  is shown with a ceiling cup  2 . The ceiling lamp  1  comprises a number of plates  3 ,  4 ,  5 , which plates  3 ,  4 ,  5  may be moved between two end positions. In a first end position, as shown in  FIG. 1 , the plates  3 ,  4 ,  5  are placed in a sphere-like form. Thus, in said first end position the plates  3 ,  4 ,  5  form a generally continuous outer surface. Expressed in another way, each plate  3 ,  4 ,  5  is placed close to or even abutting adjacent plates  3 ,  4 ,  5 . In the second end position, as shown in  FIG. 2 , the plates  3 ,  4 ,  5  are moved away from each other, whereby each plate  3 ,  4 ,  5  is placed at a distance from the adjacent plates  3 ,  4 ,  5 . The plates  3 ,  4 ,  5  may be placed in any position between the two end positions shown in  FIGS. 1 and 2 . Such an intermediate position is shown in  FIG. 3 . The light distribution of the lamp is altered depending on the position of the plates  3 ,  4 ,  5 . 
         [0023]    In the shown embodiment there are plates of two different shapes. Middle plates  3  are positioned between lower plates  4  and upper plates  5  when forming said sphere-like form. All middle plates  3  have the same shape. The lower plates  4  and upper plates  5  have the same shapes, but are placed in inverted positions in use. The plates  3 ,  4 ,  5  are normally opaque, with a reflective inner side, that is the side facing the interior of the lamp  1 . 
         [0024]    The plates  3 ,  4 ,  5  of the lamp are moved between the closed and open positions by means of a first string part  6  and a second string part  7  of a common string. The string parts  6 ,  7  are suspended below the lamp  1 . To change the position of the plates a knob  8  at the end of one of the string parts  6 ,  7  is gripped and drawn downwards. The first string part  6  is drawn downwards when moving the plates  3 ,  4 ,  5  towards the open position and the second string part  7  is drawn downwards when moving the plates  3 ,  4 ,  5  towards the closed position. As it is a common string one string part will go upwards when the other string part is pulled downwards. In other embodiments two strings will be used. 
         [0025]    The plates  3 ,  4 ,  5  are connected to a lower ring  9  and an upper ring  10 , respectively, by means of link mechanisms. An intermediate band  11  is placed between the lower ring  9  and the upper ring  10 , and the intermediate band  11  hangs down from the upper ring  10 . The upper ring  10  is provided at a lower outer circumference of a lamp holder  12 . Which lamp holder  12  is to receive a suitable light source, such as a light bulb (not shown). The lamp holder is received at the lower end of an electrical cord  13  in a normal way. The upper end of the electrical cord  13  is connected to an electrical source inside the ceiling cup  2 . At the lower part of the intermediate band  11  a wheel house  14  is placed. A wheel  30  inside the wheel house  14  receives the string. 
         [0026]    One end of upper curved arms  17  of the link mechanism are connected to the upper ring  10  in a pivot  15 . The other end of each upper curved arm  17  comprises a lower curved part  18  and an upper claw-like part  20 . A connection  24  at the end of the lower curved part  18  is fixed to a lower plate  4  of the lamp  1  in a rigid way. The upper claw-like part  20  has a lower claw  21  and an upper claw  22 . The outer end of the lower claw  21  receives a pivot  23 . The upper claw  22  has a slit  28  receiving a connection  27 , by which connection  27  a middle plate  3  is fixed to the upper curved arm  17  in a rigid way. The part of each upper curved arm  17  between the pivot  15  at the upper ring  10  and the lower curved part  18  and the claw-like part  20  has a curved form. 
         [0027]    One end of lower curved arms  26  of the link mechanisms is connected to the lower ring  9  in a pivot  16 . The form of the lower arms  26  corresponds with the form of the upper arms  17 , the difference being that they are turned in opposite ways. Thus, each lower arm  26  has an upper curved part  19  and an upper plate  5  of the lamp  1  is connected to the upper curved part  19  in a rigid way by means of a connection  25 . Furthermore, each lower arm  26  has a claw-like part connected to middle plate  3  of the lamp  1  in a rigid fashion. 
         [0028]    Each upper arm  17  of the link mechanism is placed adjacent a lower arm  26 . The claw-like parts of the adjacent upper arm  17  and lower arm  26  are connected to each other by means of the pivot  23 . Thus, the adjacent claw-like parts may turn in relation to each other. 
         [0029]    In  FIGS. 4 and 5  one upper arm  17  and an adjacent, co-operating lower arm  26  are shown in the open position of the lamp. In illustrative purpose only two co-operating upper and lower arms  17 ,  26  are shown, but it is understood that the other co-operating upper and lower arms  17 ,  26  are in corresponding positions.  FIGS. 6 and 7  show the upper and lower arms of  FIGS. 4 and 5  in the closed position of the lamp. 
         [0030]    Even though the lamp is illustrated having eight pairs of co-operating upper and lower arms  17 ,  26 , a person skilled in the art realises that any number of co-operating upper and lower arms  17 ,  26  may be used. 
         [0031]    As indicated above, by amending the size and form of the plates as well as the arms of the link mechanisms, the form of the lamp in the closed position may be amended. 
         [0032]    The lower ring  9  has a central opening receiving a rod  29 . The lower ring  9  may slid up and down on the rod  29 . Said central opening of the lower ring  9  and the rod  29  are given such shapes that the lower ring  9  is hindered from rotating in relation to the rod  29 . The rod  29  is placed hanging down from the intermediate band  11 . The length of the rod  29  should be long enough to allow the lower ring  9  to move between positions for the closed and open end positions of the plates  3 ,  4 ,  5  of the lamp  1 . In the open end position of the lamp  1  the lower ring  9  has been moved upwards on the rod  29  to become adjacent to the intermediate band  11 . The movement of the lower ring  9  is controlled by means of pulling the appropriate string part  6 ,  7 . The string is placed on and turns on a wheel  30  at the lower part of the intermediate band  11 . The string is placed on the wheel  30  with the string parts  6 ,  7  hanging down on opposite sides of the wheel  30 . The first string part  6  is received in an opening of the lower ring  9  in such a way that it can move freely in relation to the lower ring  9 . The second string part  7  is received in a fixation  31  on the lower ring  9 , by which fixation  31  the second string part is fixed to the lower ring  9 . By this arrangement the lower ring  9  will move towards the intermediate band  11  when the first string part  6  is pulled downwards. To move the lower ring  9  in a direction away from the intermediate band  11  the second string part  7  is pulled downwards. 
         [0033]    As indicate above the common string may be replaced by two strings. Whereby a first string is fixed to the upper side of the lower ring  9  and from there goes via the wheel  30  down through an opening of the opposite side of the lower ring  9 , in which opening the string can move freely in relation to the lower ring  9 . The other string is fixed to the lower ring  9  in such a way that it hangs down from the lower ring  9 . The wheel  30  is normally placed under a cover in form of the wheel house  14 , as indicated above. 
         [0034]    In  FIG. 11  one example of locking means is shown, which locking means is to hold the plates  3 ,  4 ,  5  of the lamp  1  in any desired position between fully closed and fully opened positions. The locking means has a slide  32  arranged slidable in a cavity  33  of the lower ring  9 . The slide  32  has an opening  34  to receive one of the string parts  6 . The opening  34  of the slide  32  is placed in connection with an opening of the lower ring  9  to receive the string part  6 . By means of a spring  35  the slide  32  is urged outwardly, whereby the slide  32  will be pressed against the string part  6 , which string part  6  thus will be locked in position by means of the slide and the openings receiving the string part  6 . The spring force is strong enough to keep the string lock in any desired positions for the plates  3 ,  4 ,  5  of the lamp, at the same time as the spring force is weak enough to not hinder movement of the string part  6  when a person pulls at one of the knobs  8  at the ends of the string parts  6 ,  7 . 
         [0035]    A person skilled in the art realises that any type of locking device locking the plates  3 ,  4 ,  5  in a desired position may be used. The locking means do not have to act on a string part  6 ,  7  but could act on the lower ring  9 , or one or more of the upper curved arms  17  and the lower curved arms  26 .