Plastic product dispenser body with moving bottom

Abstract

The hollow body includes a sidewall and a supporting bottom. The body has a part, forming all or part of the bottom, free to move in the axial direction under a manual axial force applied thereon, due to a portion of the flexible wall surrounding the moving part and the thickness being chosen such that the flexible wall is resilient in bending. The flexible wall is an annular portion inscribed within a circle typically centred on the axial direction of the body. The body is formed from a plastic material that can be subjected to resilient bending. The axial manual pressure applied on the moving part enables reliable and repeated displacement thereof, and triggers a technical effect inside the hollow body, due to an auxiliary part.

1 . Hollow body ( 1 ) of a dispenser ( 6 ) for a cosmetic product, typically a cosmetic product, typically with a symmetry of revolution about an axial direction ( 10 ) of the said body, comprising a sidewall ( 2 ) and a supporting bottom ( 3 ), the said sidewall ( 2 ) having an upper edge ( 20 ) typically provided with an outer thread ( 200 ), forming an opening ( 201 ), characterised in that: 
 a) the said body ( 1 ) comprises a part ( 12 ), forming all or part of the said bottom ( 3 ), free to move in the axial direction under a manual axial force applied on the said part ( 12 ), due to a portion of the flexible wall ( 11 ) of the said sidewall ( 2 ) or the said bottom ( 3 ) surrounding the said moving part ( 12 ) and the thickness being chosen such that the said flexible wall is resilient in bending and forms a hinge,    b) the said flexible wall portion ( 11 ) is an annular portion inscribed within a circle typically centred on the said axial direction ( 10 ) of the said body ( 1 ),    c) the said body ( 1 ) is formed from a plastic material that can be subjected to the said resilient bending for the said flexible wall portion ( 11 ), such that the said stress or manual axial pressure ( 7 ) applied on the said moving part ( 12 ) pushes it into the said body ( 1 ) along an axial displacement, the said moving part ( 12 ) coming out of the said body ( 1 ) and typically moving into its original axial position as soon as the said manual pressure ( 7 ) is removed,    d) the said axial displacement, when the said stress or manual pressure ( 7 ) is applied to the said moving part ( 12 ) and pushes it into the said body ( 1 ), is an axial distance varying from 2 mm to 10 mm.    
   
   
       2 . Dispenser body according to  claim 1 , in which the said plastic material comprises a blend of two plastic materials, a first plastic material with a said high bending modulus, with a bending modulus of more than 350 MPa, and a second plastic material with a said low bending modulus, the bending modulus being less than 350 MPa.  
   
   
       3 . Dispenser body according to  claim 2  in which the said first plastic material has a content by weight varying from 40% to 80%, and the content by weight of the said second plastic material varying from 60% to 20% respectively.  
   
   
       4 . Dispenser body according to  claim 2 , in which the said first plastic material is a thermoplastic material typically chosen from among PE, PP, and the said second plastic material is an elastomer, typically SEBS.  
   
   
       5 . Dispenser body according to  claim 1  in which the said sidewall ( 2 ) is a flared wall ( 2 ′), and in which: 
 a) the said sidewall ( 2 ) forms a sequence of several circular wall portions, starting from the said upper edge and working towards the bottom, typically 3 walls P 1  ( 21 ), P 2  ( 22 ) and P 3  ( 23 ), with outside diameters D 1 , D 2  and D 3  in decreasing order of diameter, each of the said diameters being taken at the top part of the said corresponding wall ( 21 ,  22 ,  23 ),    b) the said sequence of several circular wall portions, typically 3 walls P 1  ( 21 ), P 2  ( 22 ) and P 3  ( 23 ), may have decreasing average thicknesses E 1 , E 2  and E 3 ,    c) the said bottom ( 3 ) has a diameter D 4 <D 3  and a thickness E 4  equal to at least 1.5E 3 ,    d) the said thickness E 3  is chosen such that the said relatively thin wall portion P 3  ( 23 ) forms the said flexible wall portion ( 11 ) forming the said hinge and thus the said bottom ( 3 ) forms the said moving part ( 12 ).    
   
   
       6 . Dispenser body according to  claim 5 , in which: 
 a) D 2 /D 1  is between 0.80 and 0.92,    b) D 2 /D 3  is between 0.6 and 0.8,    c) D 3 /D 4  is between 0.5 and 0.7,    and in which the said sidewall ( 2 ) has an outside profile typically corresponding to a segment of a parabola.    
   
   
       7 . Dispenser body according to  claim 5 , in which the height H of the said body ( 1 ) typically varies from 30 mm to 60 mm and diameter D 1  that is larger varies from 40 mm to 70 mm.  
   
   
       8 . Dispenser body according to  claim 5 , in which: 
 a) the said average thickness E 1  of the wall Pi or the upper wall is between 5 mm and 2 mm,    b) the said average thickness E 2  of the wall P 2  or the median wall is between 1 mm and 2 mm,    c) the said average thickness E 3  of the wall P 3  or the lower wall is between 0.3 mm and  1 .    
   
   
       9 . Dispenser body according to  claim 5 , in which the said walls P 2  ( 22 ) and P 3  ( 23 ) have a typically constant thickness E 2  and E 3 , the said walls P 2  ( 22 ) and P 3  ( 23 ) being connected through an intermediate wall P 23  ( 24 ) with a variable thickness E 23  over its height H 23 , the said height H 23  being between 2 and 5 mm.  
   
   
       10 . Dispenser body according to  claim 5 , in which the said wall P 1  ( 21 ) or upper wall has a constant inside diameter over its entire height H 1 , the said height H 1  varying from 12 mm to 30 mm, and preferably from 15 mm to 25 mm.  
   
   
       11 . Dispenser body according to  claim 5 , in which the said upper edge ( 20 ) or the top part of the said wall Pi ( 21 ) has a click fit means ( 25 ) that will cooperate with an auxiliary part ( 5 ), the said auxiliary part ( 5 ) typically closing off the said opening ( 201 ) and forming means of application of the said product.  
   
   
       12 . Dispenser body according to  claim 5 , in which the said wall P 3  ( 23 ) or the lower wall has an average angular slope α 3  with the said typically plane bottom ( 3 ) varying from 20° to 40°, the said wall P 2  having an average angular slope α 2  such that α 3 =α 2 +Δα where Δα varies from 10° to 30°.  
   
   
       13 . Dispenser body according to  claim 1 , in which the said sidewall ( 2 ) forms a typically cylindrical straight skirt ( 2 ″) connected to the said bottom ( 3 ), the said bottom ( 3 ) comprising the said flexible wall portion ( 11 ) and the said moving part ( 12 ).  
   
   
       14 . Dispenser body according to  claim 13 , in which the said straight skirt ( 2 ″) has an average thickness E 1  between 5 mm and 2 mm, and the said bottom ( 3 ) includes: 
 a) a peripheral part F 1  ( 30 ) with the said average thickness E 1 ,    b) a median part F 2  ( 31 ) with thickness E 2  between 0.3 mm and  1  forming a portion of the flexible wall ( 11 ),    c) a central part F 3  ( 32 ) with thickness E 3  between 1 mm and 2 mm, the said central part F 3  ( 32 ) forming the said moving part ( 12 ) of the said bottom.    
   
   
       15 . Dispenser body according to  claim 14 , in which the said median part F 2  ( 31 ) forms or includes an outer re-entrant ring ( 310 ) with a slope β 1  varying from 30° to 70° and a projecting inner ring ( 311 ) with a slope β 2  varying from −100 to 500.  
   
   
       16 . Dispenser body according to  claim 14 , in which, when the said stress or manual pressure ( 7 ) is not applied, the said central part F 3  ( 31 ) may be offset inwards with respect to the said peripheral part F 1  by a height h varying from 2 to 5 mm, so as to avoid or limit the risk of a force being accidentally applied on the said central part F 3  ( 31 ).  
   
   
       17 . Dispenser body according to  claim 12 , in which the said straight skirt ( 2 ″) and the said bottom ( 3 ) have a radius of curvature of the fillet R varying from 5 to 15 mm, and typically from 6 mm to 10 mm.  
   
   
       18 . Dispenser body according to  claim 12 , in which the said straight skirt ( 2 ″) has a round or oval or square or rectangular cross-section, taken perpendicular to the said axial direction.  
   
   
       19 . Dispenser body according to  claim 1 , in which the said body ( 1 ) is a moulded part, typically formed by injection of the said plastic material.  
   
   
       20 . Dispenser body according to  claim 1 , in which the said axial displacement is an axial distance varying from 3 to 6 mm.  
   
   
       21 . Product dispenser comprising a body ( 1 ) according to  claim 1 , a means ( 4 ) of closing off the said opening and typically an auxiliary part ( 5 ) that depends on the said axial displacement for its operation.