This invention relates to hair clippers, and more particularly to drive systems for hair clippers driven by a rotary motor or a vibrator motor.
Hair clippers require drive systems that maintain linear motion of a reciprocating blade. To guide the reciprocating blade parallel to the stationary blade, the drive systems require precision tolerances. They may use a spring to guide the reciprocating blade in a near-linear path, but spring tolerances are difficult to sustain in manufacturing. As a result, the spring often requires adjustment at the factory assembly line to properly align the reciprocating blade with respect to the stationary blade.
Some drive systems have a guide channel formed in a thick section of the stationary blade, but the thick section is distanced from the cutting load, making the reciprocating blade guiding susceptible to binding. Moreover, sometimes an external feature (such as a cam follower flange) reciprocates outside of the housing, which is an aesthetic disadvantage, or a guide is molded on a housing that if excessively worn can require replacement of the entire housing and a more complex service repair procedure.
Another drive system design has a guide for guiding the reciprocating blade. The guide attaches to the perimeter of the clipper housings. Since a taper adjustment feature is provided on many hair clippers, this type of guide piece introduces more parts and additional manufacturing tolerances to sustain in production for the taper lever adjustment.
In addition, removal and re-assembly of the blade set can be awkward if the user in the field has to depress the spring and cam follower downward while inserting the reciprocating blade and fastening the fixed blade. Thus there is a need for improved drive systems for hair clippers.
Accordingly, one object of this invention is to provide new and improved hair clippers.
Another object is to provide new and improved drive systems for hair clippers driven by a rotary motor or a vibrator motor.
In keeping with one aspect of this invention, a hair clipper has a base housing and a secondary housing cover. A motor is secured between the base housing and the secondary housing cover. The motor can be a rotary motor having a shaft, a cam secured to an end of the shaft and a cam shaft, or a vibrator motor with a drive finger.
A cam follower is operably connected to the cam shaft or drive finger on one side of the cam follower. A blade guide is secured to the base housing, and the one side of the cam follower is operably secured to the blade guide.
A reciprocating blade is operably secured to the other side of the cam follower. A stationary blade is secured to the base housing adjacent the reciprocating blade.
The above mentioned and other features of this invention and the manner of obtaining them will become more apparent, and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, in which:
Referring to
A stationary blade 17 is secured to a taper adjustment bar 18, which in turn is slidably secured to the base housing 12a. The taper adjustment bar 18 and taper adjustment lever 13 are optional. The stationary blade 17 is operably secured to the base housing 12a, with or without blade adjustment.
A reciprocating blade 19 is operably secured adjacent the stationary blade 17. As seen in
In this embodiment, a rotary motor 20 (
The cam 24 has an off-center (i.e., eccentric) cam shaft 26 that is operably engaged with a cam follower 30. The cam shaft 26 is a drive device that fits within a drive slot cavity 32 (
An elongated guide rail 36 (
The cam follower 30 has a bottom side 40 (
A spring 51 (
The blade guide 50 is secured inside of the base housing 12a with internal screws 71 (
The U-shaped ends 38 are preferably flexible so they can be slightly compressed in the guide channel 54, and allow a light interference fit with the blade guide. A light interference fit (lubricated as needed) is beneficial since it largely eliminates the possibility of clearance between the cam follower and the blade guide. Clearance between the guide parts can cause product noise, vibration and less parallel guiding if the reciprocating blade sways in motion.
The U-shaped ends 38 are also preferably equally biased on both sides to facilitate true parallel guiding of the reciprocating blade. Preferably, the ends of the U-shaped ends are spaced apart at the widest span possible between both U-shaped ends, for optimal linear motion of the reciprocating blade. The U-shaped ends 38 are also used for pushing most hair strands out of the blade guide 50, as will be seen.
Vents 56 (
Chamfered surfaces 57 (
Referring again to
The hair clipper 10 is assembled by securing the blade guide 50 to the inside of the base housing 12a with fasteners 71 (
The motor 20, with the cam 24 previously secured to the shaft 22, is mounted in the base housing 12a either before or after the blade guide 50 is secured. The cam follower 30 is installed by placing the cam follower tab 39 beneath the taper adjustment bar 18, to stabilize the cam follower 30 (
The reciprocating blade 19 is installed on the cam follower 30 by locating the opening 21 in the blade 19 over the projection 42 in the cam follower 30. A press fit of the projection 42 in the opening 21 holds the blade 19 in place. The stationary blade 17 is secured over the reciprocating blade 19 in alignment by fastening the stationary blade 17 to the taper adjustment bar 18 (
In use, most of the cut hair strands fall away from the hair clipper 10, but some cut hair strands will presumably fall into the guide channel 54. However, most of those hair strands will be pushed out of the guide channel 54 through the vents 56 by the reciprocating action of the cam follower 30. The sloped surfaces 57 adjacent the vents 56 facilitate hair strand removal.
The cam follower 30 and blade guide 50 can have application in hair clippers having a vibrator motor, as seen in
The advantages of this invention are now apparent. The drive system uses parts that are better for sustaining precision manufacturing tolerances without assembly line adjustment. Blade alignment is improved since the guide rail and guide channel are closer to the cutting load and spaced wider to achieve optimum linear guiding. The drive system is enclosed, which is more aesthetically pleasing, and it is compact, and simpler to service or replace.
While the principles of the invention have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention.
Number | Name | Date | Kind |
---|---|---|---|
3430342 | Wahl | Mar 1969 | A |
3458932 | Fox | Aug 1969 | A |
3561116 | Wahl | Feb 1971 | A |
3589007 | Walton | Jun 1971 | A |
4985999 | Iwasaki et al. | Jan 1991 | A |
5068966 | Wahl et al. | Dec 1991 | A |
5230153 | Andis | Jul 1993 | A |
20020170180 | Brill | Nov 2002 | A1 |
Number | Date | Country |
---|---|---|
21 17 319 | Oct 1972 | DE |
2 808 135 | Dec 2014 | EP |
Entry |
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Wahl GMBH hair trimmer with pivot motor; introduced in 2011. |
Wahl Beret/Mag hair trimmers; introduced in 2002. |
Wahl rotary motor hair clipper blade set; introduced in 1990s. |
Wahl hair clipper introduced in 1969. |
Wahl Chrome Pro Clipper; introduced in Jan.-Mar. 2013. |
EP Search Report issued in EP App. No. 14 17 0570 , dated Oct. 22, 2014. |
Wahl Groomsman trimmers; introduced in1980s. |
Wahl hair clippers blade set introduced in 2009. |
Number | Date | Country | |
---|---|---|---|
20140352159 A1 | Dec 2014 | US |