US 3136058 A
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Description (OCR text may contain errors)
June 9, 1964 M. ca. ANDlS 3,136,058
HAIR CLIPPER BLADE DRIVE IN A VIBRATORY TYPE CLIPPER Filed 000. 26, 1962 INVENTOR. MHTTf/EW 6-. up/.6
ATTOZ/VEY! United States Patent 3,136,058 HAIR CLIPPER BLADE DRIVE IN A VIBRATORY TYPE CLIPPER Matthew G. Anrlis, Racine, Wis., assignor to Andis Clipper Co., Racine, Wis., a corporation of Wisconsin Filed Oct. 26, 1962, Ser. No. 233,279 1 Claim. (Cl. 30-210) This invention relates to a hair clipper blade drive in in a vibratory type clipper.
In a hair clipper of the character described, the movable blade is reciprocated on the shear plate by means of a leaf spring connected with the free end of a vibratory armature. Conventionally, the blade reciprocates in a plane which is oblique with reference to the plane of oscillation of the armature and is driven by a driver which is normally a roller mounted in the end of the driving spring and bearing between the sides of a way in the reciprocable blade. At the point where the roller is mounted, the end of the spring is approximately parallel to the plane of reciprocation of the blade, whereby the axis of the roller is normal to that plane. The Way extends transversely of the path of reciprocation to accommodate the difference between the arcuate movement of the driver and the rectilinear movement of the driven blade. While the driver normally has the form of a roller, it does not necessarily rotate.
The spring not only drives the blade but also provides the bias which holds the movable blade to the shear plate.
Because the amplitude of vibration of the armature is limited and the teeth of the shear plate and blade are relatively fine, it is important that the stroke of the reciprocable blade be maintained as accurately as possible so that a given shearing cut will be completed in each stroke. Otherwise, as the barber moves the clipper through the hair, there will be a tendency for the clipper to pull hair which is engaged without being cut.
The driver tends to wear rapidly because of the fact that in the course of its vibratory movement it must accommodate not merely for different paths of movement but also for the different planes of movement of the driving spring and the driven blade.
The present invention contemplates the provision of beveled surfaces at the sides of the slot in which the driver operates in the driven blade, the driver being tapered to exert axial thrust as well as lateral thrust in the course of its oscillation. In the preferred roller, both a spherical taper and a conical taper are superior to a cylindrical drive roller, but the conical taper is preferred. The tapered roller automatically takes up wear and retains tension, reduces noise, improves accuracy and, unexpectedly, has greatly increased life over a cylindrical drive roller. In a typical test, a cylindrical drive roller broke down after 330 hours of operation, whereas a tapered roller, at the conclusion of its test, had operated 1216 hours and was still in operable condition.
In the drawings:
FIG. 1 is a plan view of a hair clipper embodying the invention, portions of the case being broken away.
FIG. 2 is an enlarged detail view taken in section on line 22 of FIG. 1.
FIG. 3 is a view in perspective showing in mutually separated positions an assembly of driving spring and conically tapered roller, and the blade with which the roller operates.
FIG. 4 is a view taken in section on the line 4-4 of FIG. 2.
FIG. 5 is a View similar to FIG. 4 showing a modified embodiment in which the roller has a spherical bearing surface.
In all respects other than the driving connection to the reciprocable blade, a clipper exemplifying the invention is conventional. The case 6 houses a motor which includes an electromagnet 8 and an armature 10. The bottom portion of the case supports the bracket 14 upon which the shear plate 16 is mounted in any desired way. Cooperating with the teeth 18 of the shear plate 16 are the complementary teeth 20 of the reciprocable blade 22 which has the usual bearing surfaces 24, 26, slidably guided on the upper surface of the shear plate 16.
The drive spring 30 is fastened, as by screws 32, to the feed end of the vibratory armature 10 and a tension adjusting screw 28 conventionally has its head engaged with the spring and its threaded end adjustably fixed in a boss 34 at the end of the armature 10. The free end 36 of spring 30 is approximately parallel to the plane of reciprocation of the reciprocable blade 22 when the device is at rest. Obviously, the parallelism is not maintained during the vibration of the armature, because the spring oscillates and the blade reciprocates on different paths and in different planes.
The drive member 40 is mounted by a screw 42 on the free end 36 of the drive spring 30. Preferably it is a roller. In accordance with the present invention, the roller 40 has a bearing portion 44 which is tapered where it engages the beveled surfaces 46 of the blade 22. Desirably, these surfaces are machined at opposite side margins of an opening 48 which completely penetrates the blade. However, it is not necessary that there be an opening. The drive roller may be made of metal but is preferably made of synthetic resin such as nylon or Teflon.
The alternate form of the roller shown at 400 in FIG. 5 has its beveled surface 440 convex in axial section, being generally spherical, instead of being conical like the surface 44. However, while this is superior to the cylindrical rollers heretofore used, it has not been found to be as desirable as the conical bearing surface.
It is not essential that the bevel of thebearing surfaces 46 of the blade shall conform to the section of the roller. However, it is preferred that the bearing engagement between the roller and the blade shall be effected below the top surface 50 of the blade. This is true both in FIG. 4 and FIG. 5. This condition can be satisfied in a variety of ways. However, it is not essential that contact be limited to a plane below the top surface 50 of the blade, FIG. 4 showing a construction in which both sides of the conical bearing surface 44 of the roller 40 are in full engagement with the bearing surfaces 46 of blade 22 when the parts are at rest.
In a vibratory hair clipper having a reciprocable blade and an oscillatory driver having an end portion over the blade, a single substantially positive central driving connection from said driver to said blade comprising a member made of synthetic resin and tapering downwardly from the driver and having generally conical bearing surfaces of circular contour in section, means including a screw for attaching said member to the said end portion of the driver, said blade having a socket in which said bearing surfaces are disposed, the blade surfaces at ing surfaces of the member transmitting the bias to the blade.
References Cited in the file of this patent UNITED STATES PATENTS Cahill July 6, 1909 Lutes Jan. 5, 1932 Andis et a1. Feb. 9, 1954 Wahl et al Mar. 10, 1959 hj r-