Modular mechanism for office chairs and the like

Abstract

Mechanism ( 1 ) for office chairs and the like, comprising a main body ( 2 ), a support element ( 7 ) for a back ( 8 ) turnably engaged with the main body ( 2 ) through first mounting means ( 9 ), a propelement ( 10 ) for a seat ( 11 ) mounted onto the main body ( 2 ) through the second mounting means ( 12 ), in which the mounting means ( 9 ) are partially or wholly arranged within said main body ( 2 ). It can also be provided for at least two Types of mounting means ( 12 ) that can be interchangeably mounted onto the main body ( 2 ), so as to change the type of mechanism ( 1 ) according to type of a second mounting means ( 12 ) being used. It can be provided for connecting means ( 16 ) between the prop element ( 10 ) and the support element ( 7 ).

1 - 33 . (canceled)  
   
   
       34 . Mechanism for office chairs and the like, comprising: 
 a main body ( 2 ) that can be engaged with an upper end of an upright ( 4 ) defining the vertical stand of a chair ( 5 ),    a support element ( 7 ) for a back ( 8 ) of the chair ( 5 ) turnably engaged with said main body ( 2 ) by means of first mounting means ( 9 ),    a prop element ( 10 ) for a seat ( 11 ) of the chair ( 5 ) mounted onto said main body ( 2 ) by means of second mounting means ( 12 ), and    elastic prop means placed at least between said support element ( 7 ) and said main body ( 2 ),    characterized in that said first mounting means ( 9 ) are at least partially arranged within said main body ( 2 ).    
   
   
       35 . Mechanism according to  claim 34 , characterized in that also said second mounting means ( 12 ) are at least partially arranged within said main body ( 2 ).  
   
   
       36 . Mechanism according to  claim 34 , characterized in that said first and/or said second mounting means ( 12 ) are wholly housed in said main body ( 2 ).  
   
   
       37 . Mechanism according to  claim 34 , characterized in that it further comprises connecting means ( 16 ) between said prop element ( 10 ) and said support element ( 7 ).  
   
   
       38 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) are arranged at least partially within said main body ( 2 ).  
   
   
       39 . Mechanism according to  claim 38 , characterized in that said connecting means are arranged wholly within said main body ( 2 ).  
   
   
       40 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) are associated directly with said prop element ( 10 ) and with said support element ( 7 ).  
   
   
       41 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) are associated indirectly with said prop element ( 10 ) and with said support element ( 7 ).  
   
   
       42 . Mechanism according to  claim 41 , characterized in that said connecting means ( 16 ) are associated with said first mounting means ( 9 ) and with said second mounting means ( 12 ).  
   
   
       43 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) are provided with at least two separate mounting positions in which they define a different ratio between the movement of said prop element ( 10 ) and said support element ( 7 ).  
   
   
       44 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) are equipped with means ( 26 ) for changing the ratio between the movement of said prop element ( 19 ) and said support element ( 7 ).  
   
   
       45 . Mechanism according to  claim 44 , characterized in that said means ( 26 ) for changing the ratio comprise a change gear operatively placed between said prop element ( 10 ) and said support element ( 7 ).  
   
   
       46 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) comprise at least a first pulley ( 20 ) associated and rotating integrally with said support element ( 7 ), a second pulley ( 21 ) associated and rotating integrally with said prop element ( 10 ), and a flexible connecting element ( 22 ) between said first ( 20 ) and said second pulley ( 21 ).  
   
   
       47 . Mechanism according to  claim 46 , characterized in that said flexible connecting element ( 22 ) is a belt.  
   
   
       48 . Mechanism according to  claim 46 , characterized in that said flexible connecting element ( 22 ) is a chain and in that said first ( 20 ) and second pulley ( 21 ) are toothed wheels.  
   
   
       49 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) comprise at least a first toothed wheel ( 23 ) associated and rotating integrally with said support element ( 7 ), and a second toothed wheel ( 24 ) associated and rotating integrally with said prop element ( 10 ) and operatively connected with said toothed wheel ( 23 ) so as to transmit motion between the prop element ( 10 ) and the support element ( 7 ).  
   
   
       50 . Mechanism according to  claim 49 , characterized in that it further comprises at least a third toothed wheel ( 25 ) placed between said first toothed wheel ( 23 ) and said second toothed wheel ( 24 ).  
   
   
       51 . Mechanism according to  claim 49 , characterized in that said wheels ( 23 ,  24 ) are friction wheels instead of toothed wheels.  
   
   
       52 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) comprise at least an oblong connecting element ( 27 ) turnably associated with said prop element ( 10 ) and said support element ( 7 ).  
   
   
       53 . Mechanism according to  claim 52 , characterized in that said oblong connecting element ( 27 ) can be mounted onto at lest one of said prop element ( 10 ) and support element ( 7 ) in a plurality of operating positions corresponding to various connecting ratios between said elements.  
   
   
       54 . Mechanism according to  claim 37 , characterized in that said connecting means ( 16 ) comprise at least a first crank ( 17 ) and a connecting rod ( 18 ) turnably associated one with the other and operatively connected between said prop element ( 10 ) and said support element ( 7 ) so as to transmit motion.  
   
   
       55 . Mechanism according to  claim 54 , characterized in that said connecting means ( 16 ) comprise a second crank ( 19 ) turnably associated with the connecting rod ( 18 ) and with said prop element ( 10 ).  
   
   
       56 . Mechanism according to  claim 37 , characterized in that it comprises a pair of said connecting means ( 16 ) arranged symmetrically on two opposite sides of the main body ( 2 ).  
   
   
       57 . Mechanism according to  claim 37 , characterized in that connecting means ( 16 ) define a 1:1 transmission ratio between the prop element ( 10 ) and the support element ( 7 ), so as to obtain the same inclination of back and seat, and therefore a “swinging” mechanism, without a direct fastening between back and seat.  
   
   
       58 . Mechanism according to  claim 34 , characterized in that said main body ( 2 ) comprises a support frame ( 13 ) that can be engaged with said upper end of an upright ( 4 ) and at least a cover element ( 14 ) that can be associated with said support frame ( 13 ), said first and/or said second mounting means ( 12 ) being placed at least partially within said cover element ( 14 ).  
   
   
       59 . Mechanism according to  claim 58 , characterized in that said first and/or said second mounting means ( 12 ) are wholly housed in said cover element ( 14 ).  
   
   
       60 . Mechanism according to  claim 58 , characterized in that said cover element ( 14 ) is equipped with fastening means through which it can be associated in a removable way with said main body ( 2 ) so as to be interchangeable with a plurality of cover elements.  
   
   
       61 . Mechanism according to  claim 34 , characterized in that it comprises at least two types of said second mounting means ( 12 ), which can be mounted onto said prop element ( 10 ) and onto said main body ( 2 ) in an interchangeable way, so as to change the type of mechanism ( 1 ) according to the type of second mounting means ( 12 ) being used.  
   
   
       62 . Mechanism according to  claim 61 , characterized in that the second mounting means ( 12 ) comprise a first type of second mounting means ( 12 ) for securing the prop element ( 10 ) to the main body ( 2 ), and at least a second type of mounting means ( 12 ) for turnably mounting the prop element ( 10 ) onto the main body ( 2 ).  
   
   
       63 . Mechanism according to  claim 61 , characterized in that it comprises at least two types of said first mounting means ( 9 ), which can be interchangeably mounted onto said support element ( 7 ) and onto said main body ( 2 ), so as to vary the type of mechanism ( 1 ) according to the type of first mounting means ( 9 ) being used.  
   
   
       64 . Mechanism according to  claim 61 , characterized in that said at least two types of mounting means ( 9 ,  12 ) can be mounted onto said main body ( 2 ) on the same fastening spots.  
   
   
       65 . Mechanism according to  claim 61 , characterized in that said at least two types of mounting means ( 9 ,  12 ) can be mounted onto said support element ( 7 ) and/or onto said prop element ( 10 ) on the same fastening spots.  
   
   
       66 . Chair ( 5 ) characterized in that it comprises a mechanism ( 1 ) according to  claim 34.