Variable pitch multi-root blade set for hair cutting

Abstract

The blade set is operatively connected to the hair trimmer and includes a fixed blade and a moving blade configured for reciprocal movement transversely relative to the fixed blade, where at least one of the fixed blade and the moving blade includes a base and a plurality of teeth extending from the base and having at least two different root portions between adjacent teeth, wherein at least one first one of the teeth extends from the base to a first position, and at least one second one of the teeth extends from the base to a second position, such that the first position and the second position are different and form two different cutting lines for cutting hair.

Description

Technical Field

[0001] The present invention generally relates to electric hair cutting appliances, namely hair trimmers and hair trimmers, and more particularly to electric hair cutting appliances having a blade set with teeth of varying pitch and multiple roots for cutting hair on different cutting lines. Background Art

[0002] Electric hair cutting appliances, more specifically hair trimmers and hair trimmers (collectively referred to herein as "hair trimmers") are well known in the art for cutting and styling hair and for trimming the edge of a person's hairline to obtain a relatively sharply defined edge. Such devices are used by professional hairstylists and barbers, and by consumers to trim their own hair or the hair of others.

[0003] The blade set of a hair trimmer typically includes two blades: a fixed blade and a moving blade that reciprocates relative to the fixed blade. Each blade includes a plurality of teeth that protrude forward and are spaced apart along the leading blade edge that defines the cutting line. The spacing or distance between adjacent teeth is known as the tooth pitch. The tooth pitch is a factor that determines how a particular blade set cuts hair. The tooth pitch between adjacent teeth can be the same from one end of the blade set to the other, or the tooth pitch between adjacent teeth can be variable throughout the blade set, i.e., the tooth pitch between adjacent teeth is different. The tooth pitch in different blades may also be different, wherein the tooth pitch between adjacent teeth of one blade in the blade set is different from the tooth pitch between adjacent teeth of another blade in the blade set.

[0004] Similar to the pitch of the teeth, the alignment of the blades also affects how the blade set cuts hair and the operation of the hair trimmer. For example, perfectly matching the pitch between the teeth of the moving blade and the fixed blade in the blade set provides good feeding of hair into the blade set, but creates a high load on the motor of the hair trimmer, which may cause the blades to stick and may shorten the life of the motor.

[0005] Therefore, there is a need for an improved blade set for a hair trimmer which can improve the feeding and cutting of hair. Summary of the invention

[0006] The hair trimmer of the present invention meets or exceeds the above needs by a blade set designed to improve cutting efficiency. In the trimmer of the present invention, the blade set includes a fixed blade and a movable blade that reciprocates laterally, wherein the teeth on at least one of the fixed blade and the movable blade have ends or tips that form at least one cutting line for cutting hair.

[0007] In one embodiment, the blade group is operably connected to a hair trimmer and includes a fixed blade and a movable blade configured to reciprocate laterally relative to the fixed blade, at least one of the fixed blade and the movable blade includes a base and a plurality of teeth extending from the base, and has at least two different roots between adjacent teeth, wherein at least one first tooth of the teeth extends from the base to a first position, and at least one second tooth of the teeth extends from the base to a second position, so that the first position and the second position are different and form two different cutting lines for cutting hair.

[0008] In another embodiment, a hair trimmer is provided, comprising: a trimmer housing defining a longitudinal axis and a cutting end; and a trimmer blade set operatively connected to the cutting end and comprising a fixed blade and a movable blade configured to reciprocate laterally relative to the fixed blade. At least one of the fixed blade and the movable blade comprises a base and a plurality of teeth extending from the base, and having at least two different roots between adjacent teeth, wherein at least one of the teeth depends on both the first root and the second root.

[0009] In another embodiment, a hair trimmer is provided, comprising: a trimmer housing defining a longitudinal axis and a cutting end; and a trimmer blade set operatively connected to the cutting end and comprising a fixed blade and a movable blade configured to reciprocate laterally relative to the fixed blade. At least one of the fixed blade and the movable blade comprises a base and a plurality of teeth extending from the base, wherein at least one first tooth of the teeth extends from the base to a first position, at least one second tooth of the teeth extends from the base to a second position, and at least one third tooth of the teeth extends from the base to a third position, wherein the first position, the second position, and the third position are different and form three different cutting lines for cutting hair. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a top perspective view of a hair trimmer including an embodiment of a blade set of the present invention.

[0011] Figure 2 yes Figure 1 A top perspective view of a moving blade in a blade set.

[0012] Figure 3 is a schematic diagram showing different cutting areas of the blade set of the present invention.

[0013] Figure 4 is a schematic diagram showing different cutting edges of the blade set of the present invention.

[0014] Figure 5A It is a front perspective view of another embodiment of the moving blade of the blade set of the present invention.

[0015] Figure 5B yes Figure 5A An enlarged partial view of the moving blade.

[0016] Fig. 6A It is a front perspective view of another embodiment of the moving blade of the blade set of the present invention.

[0017] Figure 6B yes Fig. 6A An enlarged partial view of the moving blade.

[0018] Fig. 7A yes Figure 2 A front perspective view of the moving blade shown in FIG.

[0019] Figure 7B yes Fig. 7A An enlarged partial view of the moving blade.

[0020] Fig. 8A It is a front perspective view of another embodiment of the moving blade of the blade set of the present invention.

[0021] Figure 8B yes Fig. 8A An enlarged partial view of the moving blade.

[0022] Fig. 9 is a front view of an embodiment of a blade set of the present invention comprising partially matching teeth on a moving blade and a stationary blade, wherein the moving blade is in a first position.

[0023] Fig.10 yes Fig. 9 A front view of the blade set of the present invention, wherein the movable blade is in the second position.

[0024] Fig.11 is a graph showing different loads on the motor of a hair trimmer. DETAILED DESCRIPTION

[0025] See also Figure 1 to Figure 2 The hair trimmer of the present invention is generally designated 20 and includes a trimmer housing 22 that houses a drive motor, electronic circuitry, an optional rechargeable battery (not shown), etc., all of which are well known to those skilled in the art. In a preferred embodiment, the housing 22 is configured as two opposing clamshell halves, which is common in the industry. The housing 22 defines a longitudinal axis "LA" ( Figure 1 ) and having a cutting end 24.

[0026] The hair trimmer 20 includes a trimmer blade set 26, which includes a fixed blade 28 having a plurality of fixed blade teeth 30 and an opposing moving blade 32 having a plurality of moving blade teeth 34. When the moving blade 32 is reciprocated laterally relative to the fixed blade by a drive motor and associated power transmission components, a cutting line 33 is formed by the engagement of the teeth 30, 34. As described in detail below, the teeth 30 on the fixed blade 28 and the teeth 34 on the moving blade 32 each have a size and shape configured for cutting hair, and have a root 35, which is the base of one or more teeth, where each tooth is connected to the base 37 of the blade. The root 35 and the edges of the teeth define a space 36 between the teeth. In operation, the hair being cut extends through the space 36 between the teeth 30, 34 on the fixed blade 28 and the moving blade 32 and is cut by the opposing cutting edges of the teeth 30, 34.

[0027] refer to Figures 3 to 4 The size and shape of the spaces 36 between the teeth are particularly important in cutting and texturizing human hair. Figure 3 As shown, the spaces 36a and 36b between the teeth 30, 34 of the fixed blade 28 and the moving blade 32 form different cutting areas. For example, the upper portion 38 of each space 36a, 36b is used to produce different cutting lengths in the end textured area 39. The larger or wider middle portion of the space 36a, 36b is configured to receive more hair and form a large cutting area 40. One or more spaces 36a, 36b can extend to the base 37, toward the mounting end 42 ( Figure 2 ), wherein the lower portion of the space 36 creates a further difference in cut length and forms a root texturing region 44. Figure 4 As shown in the drawings, each tooth 30, 34 of the stationary blade 28 and the moving blade 32 has opposite sides: a left side and a right side, which form cutting edges 46a and 46b to cut hair when the moving blade moves from left to right relative to the stationary blade 28. By adjusting the size and shape of the above-mentioned areas, a desired balance is achieved between texturing and bulk hair cutting, wherein most of the texturing occurs in the end texturing area, while the further root texturing area helps to produce a softer texturing effect.

[0028] refer to Figure 5A and 5B , shows an embodiment of a blade 48 for a fixed blade 28 and / or a moving blade 32 of a blade set 26, wherein the blade 48 includes a length LB ( Figure 2) extends from a plurality of teeth 50. In this embodiment, the teeth 50 are arranged in pairs of teeth extending from a first root 52 and defining a first space 53, and the tooth pairs have a second root 54 extending between the tooth pairs and defining a second space 55. The first space 53 is the space between adjacent teeth 50 in each tooth pair, and the second space 55 is the space between adjacent tooth pairs. Figure 5B As shown, the second space 55 has a length L2 which is greater than the length L1 of the first space 53 , wherein the length is the distance from the root of the bottom end of the first or second space to the end of the tooth 50 .

[0029] In addition, the first pitch 56 between the teeth in each tooth pair 50 is different from the second pitch 58 between adjacent tooth pairs 50. In the exemplary embodiment, the first pitch between adjacent teeth in each tooth pair is 1.219 mm, and the second pitch between adjacent tooth pairs is 1.300 mm. It should be understood that the first pitch 56 and the second pitch 58 can be the same, different, or any suitable distance. And in this embodiment and the following embodiments, as described above, the pitch generally refers to the lateral spacing of the blade teeth of the trimmer. In the blade set of the present invention, the pitch is the distance from the center of one tooth to the center of the adjacent tooth. It should be understood that the pitch can also be the distance between the cutting edge of one tooth and the corresponding cutting edge of the adjacent tooth.

[0030] In the illustrated embodiment, each tooth 50 has a first cutting edge 60a and an opposite second cutting edge 60b, wherein the angle θ of each cutting edge relative to the vertical line can be the same or different. In addition, the blade 48 has a single cutting line 62 defined by the distal end or end 64 of the tooth 50, that is, the ends of the teeth are all in the same horizontal plane.

[0031] refer to Fig. 6A and 6B , shows another embodiment of a blade 65 for a fixed blade 28 and / or a moving blade 32 of a blade set 26, wherein the blade includes a plurality of tooth segments 66 extending along the length of the blade. Each tooth segment 66 includes three teeth extending from a first root 67, wherein outer teeth 68 are located on opposite sides of the tooth segment, and the length of each outer tooth is greater than the length of the middle tooth 70. A second root 69 extends between the tooth segments 66. In addition, the first space 72 (the space between each outer tooth 68 and the middle tooth 70) is the same in each tooth segment 66. The second space 74 (the space between adjacent tooth segments 66) is different from the first space 72. More specifically, as Figure 6B As shown, the second space 74 has a length L2 which is greater than the length L1 of the first space 72 , wherein the length is the distance from the first root 67 or the second root 69 to the end 76 of the outer tooth 68 .

[0032] In addition, in this embodiment, the first tooth pitch 78 (the distance between the outer teeth 68 in each tooth segment 66) is different from the second tooth pitch 80 (the distance between adjacent tooth segments 66). In the exemplary embodiment, the first tooth pitch is 1.626 mm and the second tooth pitch is 1.255 mm. It should be understood that the first tooth pitch and the second tooth pitch can be the same, different, or any suitable distance. Each tooth 68, 70 in this embodiment has a first cutting edge 82a and an opposing second cutting edge 82b, wherein the angle θ of each cutting edge relative to the vertical line can be the same or different. As shown in FIG. Figure 6B As shown in FIG. 1 , the angles θ1 , θ2 and θ3 of the opposing first and second cutting edges of the teeth 68 , 70 are different. This configuration enables the teeth 68 , 70 within each tooth segment 66 and between tooth segments to cut hair at different lengths, for example for different texturing.

[0033] In the illustrated embodiment, in each tooth segment 66, the ends 76 of the outer teeth 68 extend further outward from the blade 64 than the ends 76 of the middle teeth 70. Thus, the blade 64 has two different cutting lines, namely a first cutting line 84 formed by the ends 76 of the outer teeth 68, and a second cutting line 86 formed by the ends 76 of the middle teeth 70, as shown in FIG. Fig. 6A As shown, the hair is cut at the first cutting line or the second cutting line.

[0034] In addition, if Figure 6B As shown, the first root 67 defines a first root line transverse to the longitudinal axis of the trimmer housing, and the second root 69 defines a second root line, wherein the distance between the first root and the end of the tooth 76 is different from the distance between the second root and the end of the tooth 76. In this embodiment, some teeth (such as tooth 76) extend only from the first root 67 (first root line), while some teeth (such as tooth 68) extend from both the first root 67 (first root line) and the second root 69 (second root line). It should be understood that the blades in the blade set can have any suitable number of roots, wherein the teeth extend from one root or two roots.

[0035] Reference now Fig. 7A and 7B, shows another embodiment of a blade 88 for a fixed blade 28 and / or a moving blade 32 of a blade set 26, wherein the blade 88 includes a plurality of teeth 90 having ends 92 extending outwardly from the blade to different positions, and different roots extending between adjacent teeth to form a wave pattern extending along the length of the blade. More specifically, the teeth 90 on the blade 88 include: a first tooth 94 having a first end 96 extending outwardly from the blade to a first position; a second tooth 98 having a second end 100 extending outwardly from the blade to a second position; and a third tooth 102 having a third end 104 extending outwardly from the blade 88 to a third position. In this embodiment, the end 104 of the third tooth 102 extends farther from the base 87 of the blade 88 than the end 100 of the second tooth 98, and the end of the second tooth extends farther from the base 87 than the end 96 of the first tooth 94. As Figure 7B As shown, the end 96 of the first tooth 94 defines a first cutting line 106 , the end 100 of the second tooth 98 defines a second cutting line 108 , and the end 96 of the third tooth 94 defines a third cutting line 110 .

[0036] Furthermore, the tooth 90 extends from the first root 105a and the second root 105b and defines two different spaces between the teeth, the first space 112 being located between the first tooth 94 and the adjacent second tooth 98, and the second space 114 being located between the second tooth 98 and the adjacent third tooth 102. Figure 7B As shown, the second space 114 extends closer to the mounting end 116 of the base 87 than the first space 112. It should be understood that the first space 112 and the second space 114 can be identical, ie, the same size and shape, or can be different.

[0037] Also, in this embodiment, the plurality of teeth 90 have: a first tooth pitch 116, which is the distance between adjacent first teeth 94 and second teeth 98; and a second tooth pitch 118, which is the distance between adjacent second teeth 98 and third teeth 102. In one embodiment, the first tooth pitch 116 and the second tooth pitch 118 are the same. In another embodiment, the first tooth pitch 116 and the second tooth pitch 118 are different. It should be understood that the first tooth pitch 116 and the second tooth pitch 118 can be the same, different, or any suitable distance. In addition, each tooth 90 in this embodiment has a first cutting edge 120a and an opposite second cutting edge 120b, wherein the angle θ of each cutting edge relative to the vertical line can be the same or different. As shown in FIG. Figure 7B As shown, the opposing first and second cutting edges 120a, 120b of the first, second and third teeth 94, 98, 102 are at different angles θ1, θ2, θ3 and θ4.

[0038] refer to Fig. 8A and 8B, shows another embodiment of a blade 122 for a fixed blade 28 and / or a moving blade 32 of a blade set 26, wherein the blade 122 includes a plurality of teeth 124 having an end 126 extending outward from the blade 122 to a common position or the same position from a first root 127a or a second root 127b to form a single cutting line 128. In addition, along the length of the blade 122, there are a plurality of spaces 130 between adjacent teeth 124, which spaces are different, or may also be the same, i.e., the same size and shape. In this embodiment, the pitch between adjacent teeth 124 is different. Specifically, as Figure 8B As shown, in the exemplary embodiment, the teeth include a first pitch 132 between adjacent teeth 124 and a second pitch 134 between adjacent teeth 124. In the exemplary embodiment, the first pitch is 2.184 mm and the second pitch is 2.794 mm. It should be understood that the first pitch 132 and the second pitch 134 can be the same, different, or any suitable distance. The two different pitches (the first pitch 132 and the second pitch 134) are repeated along the length of the blade.

[0039] Furthermore, in this embodiment, each tooth 124 has a first cutting edge 136a and an opposite second cutting edge 136b, wherein each cutting edge has the same angle θ relative to the vertical line. In another embodiment, the angles of the cutting edges 136a, 136b of the teeth 124 are different. It should be understood that one or more teeth 124 of the blade 122 can have cutting edges with the same or different angles θ.

[0040] In one embodiment, the spaces between the teeth of the stationary blade exactly match the spaces between the teeth of the moving blade, so that the teeth on the stationary blade and the moving blade are substantially aligned with each other. Figures 9 to 11 In another embodiment shown in , the spaces 138 between the teeth 140 on the fixed blade 142 partially match the spaces 144 between the teeth 146 on the moving blade 148. In this way, when the moving blade 148 reciprocates relative to the fixed blade 142, the teeth 146 on the moving blade 148 at least partially extend into (or overlap) the spaces 138 between the teeth 140 on the fixed blade 142. Thus, this configuration improves the feeding of hair through the blades 142, 148 because the spaces between all teeth are opened substantially at the same time. In addition, this configuration also reduces the maximum load on the motor and / or the duration of the maximum load because all teeth do not cut hair at the same time, which in turn improves the life of the trimmer motor.

[0041] Fig.11 A graph is shown with engagement percentage on the Y-axis (i.e. the percentage of teeth of the blade set engaging hairs simultaneously) and time on the X-axis. Fig.11As shown, when the teeth on the fixed blade and the moving blade are fully or accurately matched, the feeding of hair to the blade set is improved, but the load 150 on the motor is high, because all teeth cut hair at the same time. In traditional or standard blade sets, the engagement percentage is low, which keeps the load 152 on the motor at a low level, but the feeding of hair into the teeth is sometimes hindered. In contrast, the partial matching of the blades reduces the load 154 on the motor because all teeth are not cut at exactly the same angle and at exactly the same time. And, similar to the accurate matching structure, the motor load 154 of the partially matched blade appears peak, but it is significantly less than the load 150 generated by the accurately matched blade, and is dispersed in a longer period of time. In the above-mentioned embodiment, the teeth on the fixed blade and the moving blade can accurately match or partially match each other.

[0042] Although specific embodiments of the hair trimmer and associated blade set of the present invention have been described herein, those skilled in the art will appreciate that changes and modifications may be made thereto without departing from the broader aspects of the invention as set out in the following claims.

Claims

1. A blade assembly (26), characterized in that: The blade set is operatively connected to a hair trimmer, the blade set comprising: a fixed blade (28); and a movable blade (32) configured to reciprocate laterally relative to the fixed blade, At least one of the stationary blade and the movable blade comprises a base (37) and a plurality of teeth (30, 34) extending from the base and having at least two different roots (52, 54) between adjacent teeth, wherein at least a first tooth (68) of the teeth extends from the base to a first position and at least a second tooth (70) of the teeth extends from the base to a second position, wherein the first position and the second position are different and form two different cutting lines for cutting hair.

2. The blade assembly according to claim 1, characterized in that: Each of the teeth includes a first cutting edge (82a, 120a, 136a) and a second cutting edge (82b, 120b, 136b), wherein the first cutting edge and the second cutting edge are each angled relative to a vertical line extending from the base transversely to the base, wherein the angles of the first cutting edge and the second cutting edge of at least two of the teeth are different.

3. The blade assembly according to claim 1, characterized in that: Each of the teeth includes a first cutting edge (82a, 120a, 136a) and a second cutting edge (82b, 120b, 136b), wherein the first cutting edge and the second cutting edge are each angled relative to a vertical line extending from the base transversely to the base, wherein the angles of the first cutting edges and the second cutting edges of all teeth are the same.

4. The blade assembly according to claim 1, characterized in that: Each of the teeth includes a first cutting edge (82a, 120a, 136a) and a second cutting edge (82b, 120b, 136b), wherein the first cutting edge and the second cutting edge are each angled relative to a vertical line extending from the base transversely to the base, wherein the angle of the first cutting edge and the angle of the second cutting edge of at least one of the teeth are different.

5. The blade assembly according to claim 1, characterized in that: Each of the teeth includes a first cutting edge (82a, 120a, 136a) and a second cutting edge (82b, 120b, 136b), wherein the first cutting edge and the second cutting edge each form an angle relative to a vertical line, and the vertical line extends from the base transversely to the base, wherein the angle of the first cutting edge and the angle of the second cutting edge of multiple teeth in the teeth are different.

6. The blade assembly according to claim 1, characterized in that: The teeth are formed as tooth segments (66), each of the tooth segments including at least two teeth, wherein the at least two teeth in each of the tooth segments have a first tooth pitch (78), and adjacent teeth between the tooth segments have a second tooth pitch (80), wherein the first tooth pitch and the segment tooth pitch are different.

7. The blade assembly according to claim 1, characterized in that: The teeth are formed as tooth segments (66), each of the tooth segments comprising at least two teeth, wherein the at least two teeth in each of the tooth segments have a first tooth pitch (78), and adjacent teeth between the tooth segments have a second tooth pitch (80), wherein the first tooth pitch and the segment tooth pitch are the same.

8. The blade assembly according to claim 1, characterized in that: Each of the teeth has a flat end, and the flat ends of the teeth are parallel to each other.

9. A hair trimmer, characterized in that: include: a trimmer housing (22) defining a longitudinal axis and a cutting end (24); as well as a trimmer blade set (26) operatively connected to the cutting end and comprising a stationary blade (28) and a movable blade (32) configured for transverse reciprocating motion relative to the stationary blade, At least one of the stationary blade and the movable blade comprises a base (37) and a plurality of teeth (30, 34) extending from the base and having at least two different roots (35) between adjacent teeth, wherein at least one of the teeth depends on both the first root and the second root.

10. The hair cutting and trimming device according to claim 9, characterized in that: Also included is the blade set according to claims 1 to 8.

11. A hair trimmer, characterized in that: include: a trimmer housing (22) defining a longitudinal axis and a cutting end (24); as well as a trimmer blade set (26) operatively connected to the cutting end and comprising a stationary blade (28) and a movable blade (32) configured for transverse reciprocating motion relative to the stationary blade, At least one of the fixed blade and the movable blade includes a base (37) and a plurality of teeth (94, 98, 102) extending from the base, wherein at least a first tooth (94) of the teeth extends from the base to a first position, at least a second tooth (96) of the teeth extends from the base to a second position, and at least a third tooth (102) of the teeth extends from the base to a third position, wherein the first position, the second position and the third position are different and form three different cutting lines for cutting hair.

12. The hair trimmer according to claim 11, characterized in that The teeth define at least two different roots.

13. The hair trimmer according to claim 11, characterized in that Also included is the blade set according to claims 1 to 8.

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