Rapid palatal expander and method for the assembly thereof

Abstract

Rapid palatal expander which comprises an actuator element ( 2 ) provided with a drive head ( 3 ) and with two stems ( 4 ) with opposite threads, as well as a first and a second main body ( 5, 6 ) provided with aligned female threads ( 7, 8 ) that are each engaged by a threaded stem ( 4 ) of the actuator element ( 2 ). Guide means ( 9 ) are provided for guiding the simultaneous movement of the main bodies ( 5, 6 ) along the longitudinal extension direction Y of the actuator element ( 2 ) following the rotation of the drive head ( 2 ). Such guide means ( 9 ) comprise: a first and a second pair of rods ( 11, 12 ), which are fixed in a single body with the first and the second main body ( 5, 6 ), respectively, and are slidably mutually engaged with each other in a form relationship in order to guide the movement of the two main bodies ( 5, 6 ) with a single degree of freedom in the aforesaid longitudinal direction (Y).

1 . Rapid palatal expander which comprises:
 a rod-shaped actuator element ( 2 ) with main extension in a longitudinal direction (Y), provided with a drive head ( 3 ) arranged in a substantially median position thereof, and with two stems ( 4 ) which are extended aligned in opposite directions from said drive head ( 3 ), with threads in opposite senses provided,   a first and a second main body ( 5 ,  6 ) provided with corresponding opposite first and second front face ( 5 A,  6 A) with respective female threads ( 7 ,  8 ) obtained aligned, each engaged by a threaded stem ( 4 ) of said actuator element ( 2 );   guide means ( 9 ) for guiding the simultaneous movement of said main bodies ( 5 ,  6 ) along said longitudinal direction. Y following the rotation of said drive head ( 2 );   characterized in that said guide means ( 9 ) comprise:   at least one first rod ( 11 ), which is fixed in a single body with said first main body ( 5 ), from whose first front face ( 5 A) such rod is extended towards said second main body ( 6 );   at least one second rod ( 12 ), which is fixed in a single body with said second main body ( 6 ), from whose second front face ( 6 A) such rod is extended towards said first main body ( 5 );   said first and said second rod ( 11 ,  12 ) being at least partially slidably and mutually engaged with each other in a faun relationship in order to guide the movement of said first and second main body ( 5 ,  6 ) with a single degree of freedom in the aforesaid longitudinal direction (Y).   
     
     
         2 . Rapid palatal expander according to  claim 1 , characterized in that the drive head ( 3 ) of said actuator element ( 2 ) is housed in a seat ( 14 ) delimited in a direction (X) transverse to said extension direction (Y), between said mutually engaged rods ( 11 ,  12 ), and in the direction of said extension (Y) between the first and second front face ( 5 A,  6 A) of said main bodies ( 5 ,  6 ). 
     
     
         3 . Rapid palatal expander according to  claim 1 , characterized in that said first and said second rod ( 11 ,  12 ) are extended parallel to each other on the two lateral flanks of said first and second main body ( 5 ,  6 ). 
     
     
         4 . Rapid palatal expander according to  claim 1 , characterized in that said at least one first rod ( 11 ) is hollow and said at least one second rod ( 12 ) is slidably inserted in form engagement within said first rod ( 11 ). 
     
     
         5 . Rapid palatal expander according to  claim 1 , characterized in that said guide means ( 9 ) comprise:
 a first pair of rods ( 11 ), which are fixed in a single body with said first main body ( 5 ), from whose first front face ( 5 A) such rods are extended parallel to each other towards said second main body ( 6 );   a second pair of rods ( 12 ), which are fixed in a single body with said second main body ( 6 ), from whose second front face ( 6 A) such rods are extended parallel to each other towards said first main body ( 5 ).   
     
     
         6 . Rapid palatal expander according to  claim 5 , characterized in that at least one free end of at least one rod of at least one of said pairs of rods ( 11 ,  12 ) is provided with a nose section ( 15 ) that is internally projecting towards the other rod of said pair of rods ( 11 ,  12 ), which transversely defines a reduced distance (D) and is susceptible to abut against an enlarged portion ( 30 ,  300 ) of said drive head ( 3 ) in order to define an end stop in the opening of said expander ( 1 ). 
     
     
         7 . Rapid palatal expander according to  claim 6 , characterized in that said at least one nose section ( 15 ) is obtained on at least one rod of the more internal pair of rods ( 11 ,  12 ), so as to define said reduced distance (D) therebetween. 
     
     
         8 . Rapid palatal expander according to  claim 6 , characterized in that said drive head ( 3 ) comprises a central core ( 3 ′) with width (L) less than said reduced distance (D), susceptible to translate along said extension direction (Y) without interfering with said nose section ( 15 ), and said enlarged portion ( 30 ,  300 ) mechanically associable with said core ( 3 ′) and susceptible to interfere with said nose section ( 15 ) along said extension direction (Y) in order to obtain said end stop. 
     
     
         9 . Rapid palatal expander according to  claim 8 , characterized in that said core ( 3 ′) has cylindrical form and said enlarged portion has annular ring form ( 30 ), which is mechanically fixable on the external peripheral surface of core ( 3 ′). 
     
     
         10 . Rapid palatal expander according to  claim 8 , characterized in that said core ( 3 ′) has a groove ( 16 ) associated, in which a clip is mechanically engageable that is susceptible to interfere with said nose section ( 15 ) in order to obtain said end stop. 
     
     
         11 . Rapid palatal expander according to  claim 6 , characterized in that said drive head ( 3 ) comprises a central core ( 3 ′) provided with said enlarged portion susceptible to interfere with said nose section ( 15 ) along said extension direction (Y), in order to obtain said end stop, and with at least one longitudinal outlet ( 13 ) susceptible to be crossed by said at least one nose section ( 15 ), said core ( 3 ′) having a groove ( 16 ) associated, in which a clip ( 300 ) is mechanically engageable that is adapted to close said longitudinal outlet ( 13 );
 said nose section ( 15 ) being susceptible to abut against said drive head ( 3 ) or said clip ( 300 ) in order to define an end stop in the opening of said expander ( 1 ). 
 
     
     
         12 . Method for the assembly of the rapid palatal expander according to  claim 8 , which comprises:
 a step for inserting said actuator element ( 2 ), with the core ( 3 ′) of said drive head ( 3 ) interposed between the opposite front faces ( 5 A and  6 A) of said two main bodies ( 5 ,  6 ) and with the relative stems ( 4 ) aligned with said female threads ( 7 ,  8 );   a step for the at least partial screwing of said actuator ( 2 ) in order to move said core outside the bulk of said nose section ( 15 );   a step for associating said enlarged portion ( 30 ,  300 ) with said core ( 3 ′) so as to obtain a bulk of said head ( 3 ) interfering with said nose section ( 15 ).   
     
     
         13 . Assembly method according to  claim 12 , wherein said association step provides for:
 the arrangement, during said insertion step, of said enlarged portion in ring form ( 30 ) between one said female thread ( 7 ,  8 ) and one said stem ( 4 ) so as to allow the latter to be inserted within said ring ( 30 );   a step of moving said ring ( 30 ) along said stem up to the external surface of said core ( 3 ′) and subsequent fixing thereon.   
     
     
         14 . Assembly method according to  claim 12 , wherein said association step provides for the coupling, subsequent to said screwing step, of said enlarged portion in the form of a clip ( 300 ) in a groove ( 16 ) associated with the core ( 3 ′) of said drive head ( 3 ).