Patent Application
20060064878
The present invention relates generally to hair cutting devices having a moving cutting blade and a drive system, and specifically to hair clippers having a bladeset driven by rotary motor systems.
One type of electric hair clipper used for cutting hair employs an electric motor with an eccentric drive member secured to the armature. A linkage converts rotary motion to linear reciprocating blade motion.
Conventionally, a pivoting or reciprocating driving member is used to drive a moving clipper blade of a clipper bladeset in a laterally reciprocating fashion with respect to a static clipper blade. The driving member has a contact portion which contacts the moving blade to drive the blade through the reciprocating motion. A considerable amount of wear occurs at a contact portion of the driving member, causing the contact portion to wear down or fail, while the remainder of the driving member remains relatively structurally sound and intact.
Typically, once the contact portion or tip is worn down or has failed, additional operational noise and/or reduced stroke results, causing insufficient and/or inefficient cutting. A user then has to replace the entire driving member, requiring some degree of disassembly of the drive system, and usually the clipper housing, to gain access and replace the driving member. The replacement process typically can require excessive time to disassemble and reassemble the clipper. This process is not only time consuming, but is also labor intensive and requires some mechanical inclination. Additionally, disassembly and reassembly can lead to further product failure when other clipper components are misaligned and/or damaged during the replacement process.
Thus, there is a need for a driving member assembly for a hair cutting device which addresses the drawbacks of the prior art.
The above-identified needs are met or exceeded by the present replaceable tip for use with a driving member of a hair clipper. The replaceable tip is configured to drive a moving blade, and is constructed and arranged to be replaceable upon the drive member without disassembly of a clipper housing.
An alternate replaceable tip for a driving member of a clipper is also disclosed. The replaceable tip is generally rectangular and is disposed at the end of the driving member. The replaceable tip is configured to drive a moving blade.
A method of replacing a replaceable tip of a driving member without disassembling a clipper housing is also disclosed. The method comprises the steps of unfastening and removing a bladeset from the clipper housing. The replaceable tip is removed from the driving member, and a replaceable tip is disposed on the driving member. Then, the bladeset is disposed on and fastened to the clipper housing.
In another embodiment, a driving member having a replaceable tip for a hair clipper is configured to drive a moving blade of the hair clipper. The replaceable tip and the driving member are constructed and arranged for the replaceable tip to be replaceable upon the drive member without disassembly of a clipper housing.
Referring now to
The replaceable tip 10 is configured to be removably disposed on a distal end 18 (
The driving member 12 operates as part of a drive system 28. The drive system 28 includes a motor assembly 30 and a chassis including a base plate 32 having a pair of spaced, generally parallel, normally projecting arms 34. Each of the arms 34 has a throughbore 36 dimensioned for receiving a respective end of a linear drive shaft 38. The drive shaft 38 is oriented to be parallel to the operational axis of the moving blade 26 and defines an operational path for the driving member 12. One end 40 of the drive shaft 38 is preferably splined and is secured in a friction fit into the corresponding throughbore 36.
To facilitate linear sliding of the driving member 12 upon the drive shaft 38, the driving member includes a transverse throughbore 42. At least one and preferably two drive shaft bushings 44 are slidable upon the drive shaft 38 on an inner diameter, and are slidingly received in the throughbore 42 on an outer diameter.
In the driving member 12, the throughbore 42 is preferably located in the shoulder 22. Projecting from the shoulder 22 is the neck 24 having at its end 18 the removable tip 10. The tip 10, in turn is preferably configured to be fixed to the moving blade 26 of the bladeset 16. By fixing the relative displacement of the distal end 18 of the driving member 12 with the moving blade 26 (
The body 20 defines a chamber 50 having an upper opening 52 which provides access to a cam follower 54. The cam follower 54 defines the lateral stroke of a bearing 56 rotatably engaged on a cam lug 58 of an eccentric cam 60. In operation, an armature 62 turns under power from the motor 30, the eccentric cam lug 58 follows an eccentric path defined by the cam follower 54, and the driving member 12 is pushed to move laterally along the linear drive shaft 38. Thus, the rotary motion of the motor assembly 30 is translated to the linear motion of the moving blade 26. While the present invention has been described with respect to a rotary to linear drive system 28, any electric motor powered appliance drive system that activates a moving or reciprocating member is contemplated.
The replaceable tip 10, when disposed on the distal end 18 of the driving member 12, is the portion of the driving member that contacts the moving blade 26. Typically, the moving blade 26 has a receiving formation 64 (shown hidden) configured for receiving the replaceable tip 10. In the preferred embodiment, the receiving formation 64 is a notch or groove that accommodates and mates with the replaceable tip 10 so that the transverse motion of the neck 24 is translated to the moving blade 26. Preferably, the replaceable tip 10 is tightly engaged with the receiving formation 64, however, it is contemplated that slight displacement of the receiving formation relative to the replaceable tip can occur.
When the driving member 12 translates a motion generally transverse to the longitudinal axis “a” of the clipper 14, the replaceable tip 10 is configured to remain confined within the receiving formation 64. Preferably, the replaceable tip 10 does not move in-or-out or up-and-down relative to the receiving formation 64, thereby lessening the wear introduced by impact stresses, and prolonging the life of the replaceable tip 10.
However, through use, the replaceable tip 10 will experience wear relative to the receiving formation 64. Such wear will increase the amount of play of the tip 10 in the receiving formation 64, will decrease the efficiency of the drive system 28, will usually increase operational noise of the clipper 14, and becomes generally undesirable. When the replaceable tip 10 wears down or otherwise fails, an advantage of the present replaceable tip is that it can be replaced without disassembling the drive system 28 to replace the entire driving member 12. Instead, only the bladeset 16 has to be removed from the clipper 14 to gain access to the replaceable tip 10. This is typically accomplished by exerting pressure on the moving blade 26 side of the bladeset 16 to unclip the bladeset from the clipper 14, releasing a snap fit. Alternatively, if fasteners are used to secure the bladeset to the housing, the fasteners are unfastened and the bladeset is pulled away from the clipper 14. In other units, a lock member needs to be released or moved to allow detachment of the bladeset. In such cases, the clipper body does not have to be disassembled. In some hair clippers 14, the bladeset 16 is secured to the clipper with only a snap-fit. Then, the replaceable tip 10 can be pulled off from the neck 24 of the driving member 12 with the user's fingers, a pliers, or the like. When a new replaceable tip 10 is engaged on the driving member 12, preferably by being pressure fit on the neck 24, the bladeset 16 can be refastened to the clipper 14.
Referring now to
At least one, but preferably a plurality of driving member retainer structures 72, such as snaps, lugs, bosses or ridges, are disposed on the neck 24 to be engaged in corresponding tip retainer structures 74, such as snap holes or grooves. It is also contemplated that other retainer structures may 72, 74 be used to retain the replaceable tip 10 on the distal end 18 of the driving member 12. When the driving member retainer structures 72 and the tip retainer structures 74 are engaged, the neck 24 extends within the replaceable tip 10 substantially along the length of the tip, but the neck preferably does not protrude through an opposite side 76 of the tip. In the preferred embodiment, the opposite side 76 is radiused in both the normal and longitudinal directions with respect to the clipper 14. This configuration provides a locating function with the receiving formation 64, as well as provides a curved impact surface when the replaceable tip 10 is used for arcuate motion (See
Referring now to
In the corresponding driving member 84, a driving member engagement portion 86, preferably a pin, is preferably integrally formed to protrude from the distal end 88 of a neck 90 to be received in an engagement portion 92 of the replaceable tip 84. When the pin 86 is introduced at the tapered end 82, the pin slightly protrudes from the wide end 80. Additionally, the pin 86 has a slight flare 94 (
The wide end 80 of the replaceable tip 78 is received in the receiving formation 64 of the moving blade 26. The replaceable tip 78 has side ends 96 that are preferably slightly concave in the direction normal to the engagement portion 92, as shown in
The tapered end 82 of the replaceable tip 78 and the driving member 84 preferably have a first and second locking formation 98, 100, such as a mating “V”-shaped geometry, to prevent rotation of the tip 78 relative to the driving member. Also preventing the rotation of the replaceable tip 78 relative to the driving member 84 is the engagement portion 92 and the pin 86, both of which are preferably shaped to have a slight eccentricity about the longitudinal axis “b” of the replaceable tip. In the embodiment of the tip 78, the axis “b” is oblique to the clipper axis “a”, however, other orientations are contemplated depending on the application. It is also contemplated that other shapes of engagement portions 86, 92 can be used, particularly if configured to mate but not rotate with respect to each other. Further, a configuration having a circular pin 86 and engagement portion 92 is contemplated where the additional restraint of the eccentricity is not desired, as long as relative motion of the tip to the driving member 84 is prevented.
The driving member 84, like the driving member 12, is a rotary-to-linear mechanism having a body 102, a shoulder portion 104 and the neck 90, which are integrally formed of a material selected for durability, formability and affordability. Preferably, the shoulder 104 is pivotally attached to the clipper 14 at a pivot bore 108. As the body 102 is driven by the motor assembly 30, the shoulder 64, as well as the neck 90, moves relative to the clipper 14, by sliding generally transverse and arcuate to a longitudinal axis “a” of the clipper about a rod 110. In this embodiment, a distal end 88 of the neck 90 travels a slightly arcuate path.
Driving of the body 102 is preferably effected by coupling the driving member 84 to the motor assembly 30 forming a drive system 112. In particular, the drive system 112 preferably has an eccentric cam 114 that protrudes upwardly from the drive system into a cam-receiving portion 116 of the body 102. The cam-receiving portion 116 preferably includes an opening 118 in the body 102 configured to accommodate and generally circumscribe the cam 114. In a preferred embodiment, the cam 114 is preferably round with a hollow center configured to be disposed eccentrically around a stationary shaft 120. When the motor 30 drives the drive member 84, a gear drive 122 rotates the cam 114 about the stationary shaft 120, and the eccentricity of the cam induces the body 102 to pivot about the pivot rod 110.
It is contemplated that other embodiments of driving members can be used. In one contemplated embodiment of a driving member (not shown), the driving member preferably has two legs fixedly attached to a clipper at a first end, and a bridging structure between the legs at a second end. Each leg is preferably resilient and is configured to deform. Preferably, a cam, or other mechanical member, is coupled to the bridging structure to drive the driving member. When the cam imparts transverse motion on the bridging structure, the legs of the driving member deform, and the replaceable tip 10, 78 disposed on the bridging structure reciprocates. The replaceable tip 10, 78 has an engagement portion that is configured to engage the driving member at a distal end, preferably at the bridging structure, such as by snapping, sliding, fastening, pressure fitting, or any other method. Further, it is contemplated that the replaceable tip 10, 78 may engage both the driving member and the cam (or similar mechanism), such that cam directly imparts force on the tip.
A detailed description of the preferred drive mechanism is disclosed in U.S. patent application Ser. No. ______, entitled “Rotary Motor Clipper with Linear Drive System”, Attorney Docket No. 2206.71159, filed Aug. 30, 2004, which is incorporated by reference herein.
While specific embodiments of the present replaceable tip and method of replacement have been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.
