Patent Publication Number: US-10307919-B2

Title: Sandwich structured cutter and personal hair trimmer using the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Chinese Application No. 201611042941.7 filed on Nov. 21, 2016, the entire contents of which are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The disclosure relates to the technical field of personal care supplies, and in particular to a sandwich structured cutter composed of two fixed blades and a reciprocating blade, and a personal hair trimmer using the same cutter. 
     BACKGROUND 
     Traditional personal hair trimming devices, for example, electric clippers, electric shavers and the like, all are composed of a blade set and a main body assembly. A main body part of the blade set includes a fixed blade and a reciprocating blade which are overlapped with each other. An edge of a front end of the reciprocating blade is provided with a row of cutting teeth. Both left and right edges of each cutting tooth are provided with a cutting edge. An edge of a front end of the fixed blade is provided with a row of comb teeth. An inner surface of each comb tooth contacting the reciprocating blade forms an acute angle with a lateral edge of the comb tooth. The edge of the front end of the reciprocating blade is overlapped with the edge of the front end of the fixed blade. The reciprocating blade is driven by a drive unit stretched out from the main body assembly, so that the edge of the front end of the reciprocating blade makes reciprocating motion with respect to the edge of the front end of the fixed blade, thereby trimming hairs stretching into gaps between the comb teeth of the fixed blade. 
     However, as the reciprocating blade, particularly the cutting teeth on the edge of the front end of the reciprocating blade, is exposed or partially exposed, a user may be easily hurt, or a psychological fear may be brought to the user. 
     SUMMARY 
     In order to solve the defects and shortages of existing technologies, the disclosure aims to provide a new type cutter of which a reciprocating blade is not exposed and which has a higher trimming efficiency, and provide a personal hair trimmer using the same cutter. 
     The aim of the disclosure is realized through a technical scheme as follows. 
     A sandwich structured cutter includes two fixed blades and a reciprocating blade sandwiched between the two fixed blades, wherein edges of front ends of both the two fixed blades are provided with a row of comb teeth, an inner surface of each comb tooth contacting the reciprocating blade forms an acute angle with a lateral edge of the comb tooth, an edge of a front end of the reciprocating blade is provided with a row of cutting teeth having cutting edges, the edges of the front ends of the two fixed blades are overlapped with the edge of the front end of the reciprocating blade, wherein the edges of the front ends of the two fixed blades are overlapped with each other, the edge of the front end of the reciprocating blade is sandwiched between the edges of the front ends of the two fixed blades, and the edge of the front end of the reciprocating blade is not exposed out of the edge of the front end of any one fixed blade, and the reciprocating blade is drivable, so that the edge of the front end of the reciprocating blade thereof makes reciprocating motion relative to the edges of the front ends of the two fixed blades, thereby realizing trimming of hairs. 
     Preferably, a cross section of the cutting tooth of the reciprocating blade, which is perpendicular to the length direction of the reciprocating blade, is a parallelogram, upper and lower opposite sides of the parallelogram align and close to corresponding inner surfaces of the comb teeth of the two fixed blades respectively. 
     Preferably, all of the cutting teeth of the reciprocating blade are arranged in a same direction. 
     Preferably, each of the cutting teeth of the reciprocating blade is arranged to be perpendicular to the edge of the front end of the reciprocating blade, or, each of the cutting teeth of the reciprocating blade is arranged to be inclined in a same direction at a same angle with respect to the edge of the front end of the reciprocating blade. 
     Preferably, the parallelograms of every two adjacent cutting teeth of the reciprocating blade are inclined towards each other, such that, on upper and lower ends of the every two adjacent cutting teeth, the cutting teeth are close to each other on one end while the cutting teeth are far away from each other on the other end to form a trapezoid construction. 
     Preferably, the two fixed blades are of a teeth overlapped structure, that is, the comb teeth of one fixed blade are overlapped with the comb teeth of the other fixed blade in a one-to-one correspondence manner, and gaps between the comb teeth of one fixed blade also are overlapped with gaps between the comb teeth of the other fixed blade in a one-to-one correspondence manner. 
     Preferably, the two fixed blades are of a teeth staggered structure, that is, the comb teeth of one fixed blade are overlapped with the gaps between the comb teeth of the other fixed blade in a one-to-one correspondence manner. 
     The disclosure further provides a personal hair trimmer using any one of the above sandwich structured cutters, which includes a main body assembly and a blade set; the blade set includes a cutter composed of a reciprocating blade and a fixed blade; and a drive mechanism used for driving the reciprocating blade is arranged inside the main body assembly. 
     Compared with existing technologies, the disclosure has advantages as follows. 
     1. The sandwich structure allows the cutting teeth of the reciprocating blade to be sandwiched between the comb teeth of the fixed blades, thereby avoiding the exposure of the cutting teeth of the reciprocating blade. The safety is higher. 
     2. The cross section of the cutting tooth of the reciprocating blade is of a parallelogram, so that two acute angles of the cross section of the cutting tooth of the reciprocating blade realize two times of trimming when the reciprocating blade makes reciprocating motion one time with respect to the fixed blades. The trimming efficiency is improved. 
     3. The fixed blades may adopt a teeth overlapped structure or a teeth staggered structure, which are applicable to different hair trimmers and different users. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a sandwich structured cutter according to a first embodiment of the disclosure. 
         FIG. 2  is a combined view of a sandwich structured cutter according to a first embodiment of the disclosure. 
         FIG. 3  is a perspective view of a reciprocating blade according to a first embodiment of the disclosure. 
         FIG. 4  is a combined view of a sandwich structured cutter according to a second embodiment of the disclosure. 
         FIG. 5  is a perspective view of a reciprocating blade of a sandwich structured cutter according to a third embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Embodiment 1 
     As shown in  FIGS. 1 to 3 , this embodiment provides a sandwich structured cutter, which is formed by two fixed blades  1 ,  3  and a reciprocating blade  2 . The reciprocating blade  2  is sandwiched between the two fixed blades  1 ,  3 . Edges of front ends of the two fixed blades  1 ,  3  are provided with a row of comb teeth  11 ,  31  respectively, and an inner surface of each comb tooth contacting the reciprocating blade  2  forms an acute angle with a lateral edge of the comb tooth. An edge of a front end of the reciprocating blade  2  is provided with a row of cutting teeth  21  having cutting edges. The edges of the front ends of the two fixed blades  1 ,  3  are overlapped with the edge of the front end of the reciprocating blade  2 . Herein, the edges of the front ends of the two fixed blades  1 ,  3  are overlapped with each other, the edge of the front end of the reciprocating blade  2  is sandwiched between the edges of the front ends of the two fixed blades  1 ,  3  and is not exposed out of the edge of the front end of any one of the fixed blades  1 ,  3 . The reciprocating blade  2  can be driven by a drive mechanism matched with the cutter, so that the edge of the front end of the reciprocating blade  2  makes reciprocating motion between the edges of the front ends of the two fixed blades  1 ,  3 ; during the reciprocating process, trimming edges are formed between the edge of the cutting tooth  21  of the reciprocating blade  2 , that is, the cutting edge, and the acute angle of each comb tooth  11  or  31  of the fixed blade  1  or  3 , so as to trim hairs. 
     A cross section of the cutting tooth  21  of the reciprocating blade  2 , which is perpendicular to the length direction of the reciprocating blade, is of a parallelogram, upper and lower opposite sides of the parallelogram align and close to corresponding inner surfaces of the comb teeth  11 ,  31  of the two fixed blades  1 ,  3  respectively. Two opposite acute angles of the parallelogram serve as cutting edges. 
     All of the cutting teeth  21  of the reciprocating blade  2  are arranged in a same direction. Specifically, each of the cutting teeth  21  of the reciprocating blade  2  is arranged to be perpendicular to the edge of the front end of the reciprocating blade  2 . 
     Comb teeth  11 ,  31  of the two fixed blades  1 ,  3  are in up down one-to-one correspondence, forming a teeth overlapped structure. 
     Embodiment 2 
     This embodiment provides another sandwich structured cutter. As shown in  FIG. 4 , this embodiment is similar to the Embodiment 1, with the only difference that the two fixed blades  10 ,  30  are of a teeth staggered structure, that is, the comb teeth  110  of one fixed blade  10  are overlapped with the gaps between the comb teeth  310  of the other fixed blade  30  in a one-to-one correspondence manner. The cutting teeth  210  of the reciprocating blade  20  all are sandwiched between the comb teeth  110 ,  310  of the fixed blades. 
     Embodiment 3 
     This embodiment provides yet another sandwich structured cutter. As shown in  FIG. 5 , this embodiment is similar to the Embodiment 1, with the only difference that the parallelogram of every two adjacent cutting teeth  2100  of the reciprocating blade are inclined towards each other, such that, on upper and lower ends of the every two adjacent cutting teeth  2100 , the cutting teeth are close to each other on one end while the cutting teeth are far away from each other on the other end to form a trapezoid construction. 
     Embodiment 4 
     This embodiment provides still yet another sandwich structured cutter. This embodiment is similar to the Embodiment 2, that is, the two fixed blades are of a teeth staggered structure, while the structure of the reciprocating blade is the same as or similar to that of the Embodiment 3, that is, every two adjacent cutting teeth of the reciprocating blade are inclined towards each other, such that, on upper and lower ends of the every two adjacent cutting teeth, the cutting teeth are close to each other on one end while the cutting teeth are far away from each other on the other end to form a trapezoid construction. 
     In the above Embodiment 1 and Embodiment 2, all of the cutting teeth of the reciprocating blade are arranged in a same direction, besides the above condition that each of the cutting teeth of the reciprocating blade is arranged to be perpendicular to the edge of the front end of the reciprocating blade, a condition as follows may exist that each of the cutting teeth of the reciprocating blade is arranged to be inclined in a same direction at a same angle with respect to the edge of the front end of the reciprocating blade. 
     It should be noted that, for the ordinary skill in this field, multiple improvements and modifications may be made without departing from the idea of the disclosure, and these improvements and modifications are intended to be included in the scope of protection of the disclosure. Therefore, the scope of protection of the patent of the disclosure should be based on claims appended herein.