US2790236A - Blade driving assembly for hair clippers and shavers - Google Patents

Description

April 30, 1957 M. 5. ANDIS 2,790,236

BLADE DRIVING ASSEMBLY FOR HAIR CLIPPERS AND SHAVERS Original Filed March 15, 1951 I 6 linnenior Warn/6w 6- AND/.5

M, M v M Gttornegs nited States BLADE DRIVING ASSEMBLY FOR HAIR CLIPI'EIQS AND SHAVERS Matthew G. Andis, Racine, Wis., assignor to Andis Clipper Company, Racine, Wis., a corporation of Wisconsm Original application March 15, 1951, Serial No. 215,740,

now Patent No. 2,704,887, dated March 28, 1955. Di-

vided and this application July 22, 1954, Serial No. 445,038

6 Claims. (Cl. 30210) A spring arm extends from the armature toward the tem movable blade and is tensioned by a screw connected with the armature. The tension is communicated to the movable blade by a special form of spring which accommodates relative movement between the arm and the blade resulting from the fact that the arm oscillates in a plane which is oblique with reference to the plane of blade reciprocation. The spring is centered with respect to the arm and has integral cylindrical terminal portions projecting from the arm toward the respective ends of the blade and in bearing engagement with the upper surface of the blade.

Held to the spring arm which extends from the arma ture is a plastic roller or driving collar of circular cross section and having substantial axial extent. This roller is engaged in a slot which extends transversely of the blade and corresponds in width to the diameter of the roller. The elongation of the slot and the length of the roller accommodate the relative movement between the blade and the arm while positively transmitting motion from the arm to the blade in the direction of blade reciprocation. To avoid interference with the free movement of the roller through the slot, the plastic guide element disposed in the blade channel is cut away centrally to leave an opening in the range of movement of the roller.

In the drawings:

Fig. lis a plan view of the forward end of a reciprocable blade clipper, of a type such as is used in shaving, portions of the case being broken away to expose the shearing head.

Fig. 2 is a view on an enlarged scale taken in section on the line 22 of Fig. 1.

Fig. 3 is a view further enlarged, taken in section on line 33 of Fig. 4.

Fig. 4 is a plan view of the blade assembly with portions of the reciprocable blade broken away to expose a plastic guide element which is fastened to the shear plate.

Fig.5 is a bottom plan view of the reciprocable blade and driver. i

Fig. 6 is a view taken in section on the line 66 of Fig. 5.

Although the present invention is not concerned with the motor, portions of a motor of the vibratory armature type are illustrated in Fig. 1 and Fig. 2. There is a core frame 7 mounted in the clipper case 8 and supporting winding 9. The poles, one of which is shown at 10, are energized intermittently, as by alternatingcurrent, to atice tract the vibratory armature 11, which has a transversely extending arm 12 in advance of the motor.

Screwed to the arm 12 of armature 11 is the mounting portion 13 of the tension spring 14. Passing through the mounting portion is a tension adjusting screw 15 threaded into an ear 16 of the armature. At its outer end, the tension spring 14 carries a driving collar or roller 20 which desirably takes the form of a plastic bead internally screw threaded to receive the screw 21 which passes through the end of the tension spring 14 to hold the bead to the spring. Screw 21 also passes through an aperture in an equalizing spring 22 having an upturned lip 23 engaged with the end of the tension spring 14 to hold the equalizing spring at right angles. The equalizing spring has its end portions 24 turned downwardly and thence curving upwardly as shown in Figs. 1 and 6 to provide downwardly convex bearing portions which test on the upper surface of the reciprocable cutting blade 25 at points spaced laterally from the elongated slot 26 in such blade wherein the driving collar 20 is confined. The width of the slot 26 substantially conforms to the diameter of the driving head 20 as shown in Fig. 5. The side margins of the slot constitute bearing thrust shoulders engaged by the head to transmit reciprocatory motion to the blade during the oscillation of the tension spring arm 14 by which the head is carried.

Due to the fact that the blade is reciprocable in a plane obliquely inclined with reference to the plane in which the. armature 11 oscillates, it is necessary to accommodate relative displacement between the tension spring and the blade in addition to relative oscillation of the tension spring respecting the plate. The cylindrical form of the driving collar 20 accommodates the oscillation. Relative displacement due to the fact that the blade reciprocates, while the armature and tension spring oscillate, is accommodated by the length of the slot 26, while the slight rocking movement attributable to the difference in angle of the planes aforesaid is accommodated by the transverse equalizing spring 22 and the movement permitted the cylindrical collar in slot 26. This relative movement is vertical as well as fore and aft respecting the blade.

A bracket 27 projecting forwardly from the clipper case, as shown in Figs. 2 and 3, has an upwardly inclined arm 28 to which the shear plate 30 is held by screws 31 (Fig. 3, passing through apertures 32) Fig. 4. The

shear plate is provided with ground bearing surfaces at v 33, 34, and is provided at its forward margin with notches defining very fine teeth 35 which project from bearing space 33. The concavity of the blade at 36 between the bearing surfaces is merely for relief.

Spanning the concavity at 36 is the prefabricated guide member 40 desirably made of plastic and preferably cut from a sheet of plastic. It is generally rectangular but has marginal guide surfaces only at its corners at 41, 42, 43, and 44, as best shown in Fig. 4. Between surfaces 41 and 42 at its outer margin and surfaces 43 and 44 on its rear margin it is relieved. Projecting centrally from its rear margin is a mounting tongue 45 anchored by screws 46 to the guide plate 30. The heads of screws 46 may engage an apertured clamp plate 47 to distribute on the surface of guide member 40 the clamping pressure of screws 46. The unused central part of guide member 40 may be cut away at 48 so as not to obstruct the freedom of movement of the driving collar 20.

The under surface of the reciprocable blade 25 is channeled as best shown in Fig. 3. Its flanges project downwardly to provide a forward bearing flange 49 sliding on the bearing surface 33 of the shear plate. Its rear flange 50 is discontinuous, being relieved at 51 to clear the positioning arm 45 of guide member 40. The discontinuous bearing flange 50 rides upon the shear plate bearing surface 34.

The inner margin 52 of the forward flange of the reciprocable blade bears against the marginal surfaces 41 and 42 of guide member 4a9, while the inner surface 53 of the rear flange of blade 25 bears against the rear marginal bearing surface 43 and 44 of guide member 40. The complementary finished surfaces of the hardened steel blade 25 and the plastic guide element accurately guide the reciprocation of the blade with a minimum of friction and much less expense than would be required to grind similar surfaces on the hardened steel of the shear plate 30. By fabricating the guide member 40 from plastic, the blade 25 moves smoothly to reciprocate its teeth 55 over the teeth 35 of the shear plate to elfect the desired shearing action.

The guard, generically represented by reference character 60, comprises a light metallic frame with its margin stiffened at 61 by folding the metal back upon itself. The cross bar portion 62 of this frame has fine teeth 63 which desirably are spaced forwardly from, the register with the underlying teeth 35 of the shear plate but are obliquely disposed with reference to the plane of the shear plate, at an obtuse angle thereto, as clearly illustrated in Figs. 2, 3 and 4. The tooth cross bar 62 of the guard frame 60 is supported by arms 64 which embrace the sides of the shear plate, as best shown in Figs. 1 and 4, and are connected thereto by cars 65 underlying the top of the shear plate and by a single screw 66 passing through the rear transverse bar portion 67 of the guard frame.

The rearward rake of the forward cross bar 62 of the guard frame, plus the provision of the teeth 63 therein, permits the hair to reach the teeth of the shear plate and yet guards the flesh from being caught between the teeth of the shear plate and the reciprocating blade. The separate pro-fabrication of the guard frame greatly reduces the expense of providing the shear plate with a corresponding guard; yet the flanged construction of the arms 64 and the engagement of these arms and their ears 65 with the shear plate provides a construction substantially as rigid as if the guard and the shear plate were made in one piece. 7

While the device resembles a hair clipper, and may be used as a hair clipper, the fineness of its teeth, adapt it for dry shaving. Therefore, reference to the device as a clipper is intended to be generic and not to preclude the utility of the clipper for shaving purposes.

I claim:

1. In a clipper, the combination witha reciprocable blade and a vibratory driving arm therefor, the vibratory driving arm including a tension spring and adjusting means operatively connected thereto for adjusting the tension in the tension spring which is transmitted to the reciprocable blade, equalizing spring means for resiliently biasing the tension spring away from the reciproeable blade, the blade and the arm having means guiding them for movement in obliquely related planes, of a roller connected to the end of the arm and projecting across the reciprocatory path of movement of a portion of the blade, the blade having opposed shoulders laterally fitted to the roller and extending substantially at right angles to the path of blade reciprocation, the space between said opposed shoulders being open in the direction of shoulder extent for a distance sufiicient to accommodate relative movement between the roller and the blade in the direction of shoulder extent, the roller constituting a non-metallic plastic whereby noise is minimized and the rotative change of position of the roller surfaces contacting the shoulders distributes wear.

2. In a clipper, the combination with a reciprocable blade and a vibratory driving arm therefor, the blade and the arm having means guiding them for movement in obliquely related planes, of a roller connected to the end of the arm and projecting across the reciprocatory path of movement of a portion of the blade, the blade having opposed shoulders laterally fitted to the roller and extending substantially at right angles to the path of blade reciprocation for a distance sufiicient to accommodate relative movement between the roller and the blade in the direction of shoulder extent, said arm having a leaf spring centrally connected to it and having free ends extending toward the ends of the blade, the ends of the spring having downwardly convex terminal portions in bearing engagement with the top surface of the blade for transmitting pressure from the arm to the blade while accommodating relative movement between the arm and the blade in consequence of the dilferent planes in which the arm and blade operate.

3. The device of claim 2 in which the spring has an upturned ear engaged with the end of the arm to position the spring substantially at right angles to the arm, the spring being interposed between the arm and said roller, said arm having a screw extending through it and through the spring into the roller.

4. In a clipper, the combination with a shear plate having a guide member extending longitudinally thereof and provided with a central opening, of a channeled blade positioned over the guide member and guided thereon for longitudinal reciprocation, said blade having a slot registering with the opening of the guide member and elongated transversely of the direction of reciprocation, a driving arm mounted for oscillation in a plane oblique with reference to the plane of said blade and having a terminal portion overlying the blade and approximately parallel therewith, and a member connected with said arm and extending therefrom into the slot of the blade for movement through the blade in the course of blade reciprocation and in consequence of the different planes of arm and blade movement, said member having bearing engagement with the sides of said slot and being free to move longitudinally of the slot in the course of relative movement of the arm and blade.

5. The device of claim 4 in which said member is substantially cylindrical and comprises non-metallic plastic.

6. The device of claim 4 in which said arm is provided with a leaf spring centrally connected to it and having an integral portion engaged with said arm to maintain said spring substantially at right angles to the arm, the spring having free end portions which are downwardly convex and in bearing engagement with the blade at points spaced outwardly toward the ends of the blade from the slot in which said member is disposed.

References Cited in the file of this patent UNITED STATES PATENTS Andis et a1. Feb. 9, 1954

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