Rotary shaver with improved support structure for shaving heads

Abstract

A shaving device comprises a head structure ( 2 ) and a base structure ( 4 ). The head structure ( 2 ) is configured to retain and support at least one shaving head ( 30 A, 30 B, 30 C). The head structure ( 2 ) is releasably retainable on the base structure ( 4 ). The base structure ( 4 ) is free of support elements in an area of an outer circumference of the head structure ( 2 ) such that the head structure ( 2 ), when coupled to the base structure ( 4 ), is not supported in the area of its outer circumference. The head structure ( 2 ), when coupled to the base structure ( 4 ), is substantially only retained on the base structure ( 4 ) by a retaining force provided by a retaining structure of the base structure ( 4 ). When an overloading force is exerted on the head structure ( 2 ), the force is transferred to a coupling element ( 8 ) arranged in a central area ( 2 A) of the head structure ( 2 ) such that the coupling element ( 8 ) is released from the retaining structure of the base structure ( 4 ) in order to prevent damage to the head structure ( 2 ).

The invention claimed is: 
     
       1. A shaving device comprising a base structure and a head structure, wherein the head structure comprises:
 a head support structure configured to hold at least one shaving head;   a coupling element arranged in a central area of the head structure; and   
       wherein the base structure comprises:
 a retaining structure configured for releasably retaining the coupling element for coupling the head structure to the base structure; and 
 
       the base structure being free of support elements in an area of an outer circumference of the head structure such that the head structure, when coupled to the base structure, is not supported in the area of its outer circumference, and the head structure, when coupled to the base structure, being substantially only retained on the base structure by a retaining force exerted by the retaining structure on the coupling element,
 wherein the coupling element is a shaft-like element protruding from the central area of the head structure and comprising, at a distal end thereof, a sloped surface facing the head support structure, 
 wherein the retaining structure comprises 
 a retaining recess for receiving the coupling element; and 
 a spring element at least partly provided in the retaining recess, the spring element being arranged for engaging the sloped surface of the coupling element such that the coupling element is retainable in the retaining recess, 
 and wherein the sloped surface protrudes from the shaft-like coupling element. 
 
     
     
       2. The shaving device as claimed in  claim 1 , wherein the head structure, when coupled to the base structure, is solely supported by the coupling element. 
     
     
       3. The shaving device as claimed in  claim 1 , wherein a drive shaft for driving the at least one shaving head extends between the base structure and the head structure through the coupling element. 
     
     
       4. The shaving device as claimed in  claim 1 , wherein the head support structure is configured to support at least two rotary shaving heads, the coupling element being arranged in a center of a substantially circular area, the substantially circular area being restricted by a rotary shaft of each rotary shaving head. 
     
     
       5. A head structure for use in the shaving device as claimed in  claim 1 , the head structure comprising:
 a head support structure configured to hold at least one shaving head;   a coupling element arranged in a central area of the head structure;   
       wherein the head structure, when coupled to the base structure, is retainable on the base structure substantially only by a retaining force provided by the coupling element. 
     
     
       6. A shaving device comprising a base structure and a head structure, wherein the head structure comprises:
 a head support structure configured to hold at least one shaving head;   a coupling element arranged in a central area of the head structure; and   
       wherein the base structure comprises:
 a retaining structure configured for releasably retaining the coupling element for coupling the head structure to the base structure; and 
 
       the base structure being free of support elements in an area of an outer circumference of the head structure such that the head structure, when coupled to the base structure, is not supported in the area of its outer circumference, and the head structure, when coupled to the base structure, being substantially only retained on the base structure by a retaining force exerted by the retaining structure on the coupling element,
 wherein the coupling element is a shaft-like element protruding from the central area of the head structure and comprising, at a distal end thereof, a sloped surface facing the head support structure, 
 wherein the retaining structure comprises 
 a retaining recess for receiving the coupling element; and 
 a spring element at least partly provided in the retaining recess, the spring element being arranged for engaging the sloped surface of the coupling element such that the coupling element is retainable in the retaining recess, 
 and wherein a collar is provided around the coupling element for abutting on an edge around the circumference of the retaining recess. 
 
     
     
       7. The shaving device as claimed in  claim 6 , wherein the coupling element is substantially cylindrical and the sloped surface is provided in a coupling recess in the coupling element. 
     
     
       8. The shaving device as claimed in  claim 7 , wherein an inner diameter of the retaining recess and an outer diameter of the substantially cylindrical coupling element are substantially equal. 
     
     
       9. The shaving device as claimed in  claim 6 , wherein the distal end of the coupling element is at least partly beveled for forcing the spring element aside when the coupling element is being inserted in the retaining recess. 
     
     
       10. The shaving device as claimed in  claim 6 , wherein a drive shaft for driving the at least one shaving head extends between the base structure and the head structure through the coupling element. 
     
     
       11. The shaving device as claimed in  claim 6 , wherein the head support structure is configured to support at least two rotary shaving heads, the coupling element being arranged in a center of a substantially circular area, the substantially circular area being restricted by a rotary shaft of each rotary shaving head. 
     
     
       12. A head structure for use in the shaving device as claimed in  claim 6 , the head structure comprising:
 a head support structure configured to hold at least one shaving head;   a coupling element arranged in a central area of the head structure;   
       wherein the head structure, when coupled to the base structure, is retainable on the base structure substantially only by a retaining force provided by the coupling element. 
     
     
       13. A shaving device comprising:
 a head structure comprising a head support structure configured to hold at least two rotary shaving heads, the head structure further including a shaft-like coupling element arranged in a central area of the head structure;   a base structure that includes a retaining structure configured for releasably retaining the coupling element in a retaining recess to couple the head structure to the base structure, the base structure being free of support elements in an area of an outer circumference of the head structure such that the head structure, when coupled to the base structure, is not supported in the area of its outer circumference, and the head structure, when coupled to the base structure, is substantially retained on the base structure by a retaining force exerted by the retaining structure on the coupling element;   a collar shaped and configured to abut the base structure at an edge around the retaining recess; and   a spring element that engages a sloped surface to retain the shaft-like coupling element in the retaining recess, wherein the engagement between the spring element and the sloped surface is overcome where the head structure receives a sufficiently large load, thereby disengaging the spring element from the sloped surface to release the head structure from the base structure.   
     
     
       14. The shaving device of claim 13, wherein a drive shaft for driving the at least one shaving head extends between the base structure and the head structure through the coupling element. 
     
     
       15. The shaving device of claim 13, wherein the at least two rotary shaving heads comprise three rotary shaving heads. 
     
     
       16. The shaving device of claim 13, wherein the base structure is mounted on a handle. 
     
     
       17. The shaving device of claim 13, wherein spring force applied by the spring element on the sloped surface pulls the coupling element inwards into the retaining recess, and the spring force is overcome where the head structure receives the sufficiently large load.