Abstract:
A hinge for wings or doors, in particular of electrical appliances, having a first element, a second element and a rocker lever for connecting the first and second elements; the lever pivots on the second element and has a first arm integral with the first element to render the first and second elements movable relative to one another with a tilting action between a closed position and an open position; the second element consisting of a substantially box-shaped body containing both elastic parts, inserted between the second element and a second arm of the lever to apply an elastic action on the lever, and a damping device, for applying a damping action on the lever during the reciprocal motion of the first and second elements, when the closed position is almost reached.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a hinge for wings or doors. 
         [0002]    The use of a hinge made in accordance with the present invention is particularly advantageous for constraining the door of an electrical appliance to the respective supporting frame. 
         [0003]    In the following description and by way of example only, without limiting the scope of the invention, the present invention is described with reference to an oven. 
         [0004]    In known types of ovens hinges usually comprise two separate elements, kinematically connected to one another and both having a box-shaped structure. More precisely, one of the two box-shaped structures is fixed to the oven supporting frame, at one side of the oven mouth, whilst the other is fixed to one edge of the door, which is that way is rendered movable with a tilting action relative to the above-mentioned frame. 
         [0005]    Between the two box-shaped structures a lever, usually a rocker lever, is operatively inserted, pivoting on one of the two box-shaped structures, usually on the one fixed to the door, and having a first arm rigidly constrained to the other of the two box-shaped structures. The second arm of the lever, coplanar with the first, is operated on by elastic elements which influence the movement of the door, for both opening and closing. Said elastic elements are housed in the box-shaped structure to which the lever is hinged and, more precisely, operate between that box-shaped structure and a rod positioned inside it. The free end of the rod, that is to say the end not interacting with the elastic elements, pivots at the above-mentioned second arm of the lever. 
         [0006]    During door rotation starting from the closed position, the elastic elements oppose, during a first step, the detachment of the door from the oven supporting frame and, in a second step, subsequent rotation of the door and its consequent lowering to an end of stroke position in which the oven mouth is completely open. In this second opening step, the door, under the combined action of its own weight which promotes its descent and of the elastic elements which apply a braking action, performs a gradual rotation. 
         [0007]    During door rotation starting from its open end of stroke position, the action of the elastic elements is first balanced by the weight of the door, initially guaranteeing gradual closing rotation; however, then, in the absence of a braking action by the user, the elastic elements push the door towards the oven frame with such a force that it often closes in a rather sudden and noisy way. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention has for an aim to provide a hinge for wings or doors which is free of the above-mentioned disadvantage. 
         [0009]    Accordingly, the present invention provides a hinge for wings or doors comprising the features described in any of the claims herein. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present invention is now described, by way of example and without limiting the scope of application, with reference to the accompanying drawings, in which: 
           [0011]      FIGS. 1   a  and  1   b  are respectively a front view and longitudinal section of a hinge made in accordance with the present invention, in its closed position and associated with an oven, the latter only partly, schematically illustrated; 
           [0012]      FIG. 2  is an exploded view of the hinge of  FIG. 1   a;    
           [0013]      FIGS. 3   a ,  3   b  and  3   c  are respectively a front view, a longitudinal section and a perspective view with some parts cut away for clarity, of the hinge of  FIG. 1   a  in an intermediate position; and 
           [0014]      FIGS. 4   a  and  4   b  are respectively a front view and a longitudinal section of the hinge of  FIG. 1   a  in its open position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    With reference to  FIGS. 1   a  and  1   b , the numeral  1  denotes as a whole an oven comprising a frame  2  to which a door  3  is connected by two hinges  4 , only one of which is illustrated. 
         [0016]    Each of the two hinges  4  comprises a first element  5 , fixed to the oven  1  frame  2  at a respective side of the oven mouth, and a second element  6 , fixed to a respective edge of the door  3 . In particular, the shape of the first element  5  and the second element  6  is substantially box-shaped and extended and they are kinematically connected to one another by a connecting lever  7  which is also part of the hinge  4 . The lever  7  is a rocker lever, pivoting on the second element  6  by means of a pin  8  and has a first arm  9   a  rigidly constrained to the first element  5  to render the door  3  movable with a tilting action relative to the frame  2  between a closed position and an open position. 
         [0017]    The central longitudinal axes of the lever  7  and of the second element  6 , labeled A and B respectively, lie in a plane at a right angle to the central longitudinal axis of the pin  8 , labeled C, which is the axis of rotation of the door  3  relative to the frame  2 , and they are at a right angle to one another in the above-mentioned closed position ( FIGS. 1   a  and  1   b ) and substantially aligned in the above-mentioned open position ( FIGS. 4   a  and  4   b ). 
         [0018]    As illustrated in  FIG. 1   b , the second element  6  has a transversal separator  10 , in an intermediate position between the two longitudinal ends of the second element  6 , specifically between the end hinged to the lever  7 , labeled  11 , and an end opposite to the latter, labeled  12 . 
         [0019]    Between the separator  10  and the end  12  there is a pre-compressed helical spring  13 , held in contact with the separator  10  by the head  14  of a rod  15  positioned coaxially inside the spring  13 . 
         [0020]    The rod  15  exits the spring  13  longitudinally with one end  16 , which passes through an opening made in the separator  10  and points towards the above-mentioned end  11 . In this way, the opening made in the separator  10  acts as a guide for the rod  15 , constraining it to a longitudinal linear motion. 
         [0021]    The end  16  of the rod  15  is hinged, by a pin  17 , to the first longitudinal end  18  of a fork  19 , whose second longitudinal end  20  is hinged to the lever  7  by a pin  21  positioned near the above-mentioned pin  8 . The pin  17  is slidably constrained to two guide and end of stroke slots  22 , made in the sides of the second element  6  and extending in a prevalent direction of extension parallel with the direction B. 
         [0022]    The position of the pin  21 , which is closer to the axis B than the pin  8 , and the pre-compression of the spring  13 , guarantee an elastic action which tends to continuously push and hold the door  3  in its closed position. 
         [0023]    Only when the closed position is almost reached, from and towards the closed position, overlapping with the above-mentioned elastic action of the spring  13  there is the action of another pre-compressed helical spring  23 , designed to operate in conjunction with a cam  24  made on a second arm  9   b  of the rocker lever  7 , through a rod  25  acting on a cam follower  26 , to give the door  3  a spring-to closing movement and to define a door stable semi-open position. Specifically, the follower  26  is supported by a pin  27  slidably constrained to two guide and end of stroke slots  28 , made in the sides of the second element  6  and extending in a prevalent direction of extension parallel with the direction B. The follower  26  is pushed towards the cam  24  by a race made on one end of the rod  25 , and the latter is pushed by the spring  23  which is stopped in contact with a transversal separator  29  in the second element  6 . The separator  29  is in an intermediate position between the separator  10  and the end  11  of the second element  6  and has an opening which acts as a guide for the rod  25 , so as to constrain the rod to a longitudinal linear motion. 
         [0024]    The spring  23  is smaller than the spring  13 , since, while the function of the spring  13  is mainly to balance the weight of the door  3 , the function of the spring  23  is, as indicated, to give the door  3  a spring-to closing movement and to define a door stable semi-open position. 
         [0025]    The two springs  13  and  23 , the relative rods  15  and  25 , the fork  19  and the cam follower  26  as a whole form elastic means  30 , inserted between the second element  6  and the lever  7  to apply on the lever  7  a two-step elastic action, specifically, during a first step, when the closed position is almost reached, from and towards the closed position, in which the action of the two springs  13  and  23  overlaps, and in a second step, between the above-mentioned door  3  stable semi-open position and the fully open position, in which the elastic action on the lever  7  is only applied by the spring  13 . 
         [0026]    Each of the two hinges  4  also comprises damping means  31 , contained in the second element  6  and designed to apply a damping action on the lever  7  at the end of the closing stroke, that is to say, during the reciprocal motion of the first element  5  and the second element  6 , when the door  3  closed position is almost reached. 
         [0027]    The damping means  31  comprise a gas or fluid cylinder  32 , having an outer body  33  mounted in the second element  6 , near the longitudinal end  12  of the latter, and a rod  34  which can move with linear motion relative to the outer body  33 . 
         [0028]    The outer body  33  is housed in a fixed position in a support  35  which is constrained to the above-mentioned end  12  by a cylindrical hinge  36 . 
         [0029]    The rod  34  consists of a first portion  37  acting directly on the cylinder  32  piston and of a second portion  38  forming an extension, having a first longitudinal end  39  connected to the first portion  37  and a second longitudinal end  40  which is free, designed to act on the lever  7  during the reciprocal motion of the first element  5  and the second element  6  and when the closed position is almost reached. 
         [0030]    For this purpose, the lever  7  has two thrust projections  41 , extending in such a way that they are aligned with one another longitudinally from two opposite faces of the lever  7 , and the end  40  has a fork-shaped free end portion, designed to make contact with the projections  41 , simultaneously, when the door  3  has almost reached its closed position, and to remain in contact until the closed position is reached. As illustrated in  FIG. 2 , the projections  41  are formed by the two longitudinal ends of a cylindrical element  42 , inserted in a through-hole  43  in the lever  7  and rigidly constrained to the lever. 
         [0031]    The following is a brief description of the operation of one of the two hinges  4  starting at the door  3  closed position, illustrated in  FIGS. 1   a  and  1   b.    
         [0032]    The torque applied to the door  3  when it is opened by the user and, beyond a predetermined rotation, by the weight of the door  3 , conflicts with the torque generated by the elastic means  30 , which therefore render the movement of the door  3  towards the fully open position gradual and subject to a braking action. During the initial opening step, the action applied on the lever  7  by the damping means  31 , which continues for as long as there is contact between the end  40  and the projections  41 , is negligible compared with the torque applied by the user. 
         [0033]    Starting from the door  3  fully open position, a rotation of the door towards the closed position is promoted by the action of the elastic means  30  and is initially hindered by the weight of the door  3 . When the door  3  reaches an intermediate closing position, in which contact is made between the end  40  and the projections  41  ( FIGS. 3   a ,  3   b  and  3   c ), following cylinder  32  compression, the damping means  31  apply a damping action conflicting with the closing action applied by the elastic means  30 , and therefore render the door  3  movement towards the fully closed position gradual and subject to a braking action. 
         [0034]    It is therefore evident that, even in the absence of a braking action by the user, the door  3 , pushed towards the oven  1  frame  2  by the elastic means  30 , reaches the frame in a gentle, silent way thanks to the end of stroke damping provided by the damping means  31 . 
         [0035]    It should also be emphasized that the damping means  31  are housed in the hinge  4 , in a position hidden from view and protected from impacts or dirt, with obvious advantages in terms of appearance and reliable operation. 
         [0036]    According to an alternative embodiment, not illustrated, the first element  5  is fixed to one edge of the door  3  and the second element  6  is fixed to the oven  1  frame  2  at one side of the mouth of the oven. 
         [0037]    It is also evident that, in addition to the specific example of use described above, a hinge of the type disclosed may advantageously be used to constrain a generic wing to a respective frame.