US2814866A - Razor having plural cutting heads which are operated in opposite directions by a vibrator type of motor - Google Patents

Description

Dec. 3, 1957 s. M. BAGNO 2,814,866

RAZOR HAVING PLURAL CUTTING HEADS WHICH ARE OPERATED IN OPPOSITE DIRECTIONS BY A VIBRATOR TYPE OF MOTOR Filed Oct. 7, 1953 United States Patent RAZOR HAVING PLURAL CUTTING HEADS WHICH ARE OPERATED IN OPPOSITE DI- RECTIONS BY A VIBRATOR TYPE OF MOTOR Samuel M. Bagno, Long Island City, N. Y.

Application October 7, 1953, Serial No. 384,708

2 Claims. (Cl. 30-43) This invention relates to electric razors and more particularly to an improved drive mechanism for razors that will provide high operating speeds with relatively little attendant vibration.

Broadly, electric razors employ two general types of drives for the oscillating head. The more common type is a conventional motor drive which has the advantage of low speed operation to avoid vibration of the razor as a unit which materially interferes with the cutting efficiency thereof. The second type, and far more inexpensive, is the vibrator drive powered by alternating current. This type of drive has the advantage of high cutting speed but the attendant vibration of the entire razor is of such a large relative amplitude that the cutting efiiciency is far below that of the slower speed motors. High cutting speeds are however desirable in electric razors since they afford a cleaner more uniform shave, but heretofore the vibration problem resulting from high speeds has not been successfully solved.

Accordingly one of the objects of this invention is to provide a highly improved drive for an electric razor that provides high operating speeds together with high cutting efficiency and low attendant vibration of the razor and cutting heads. This is attained through improved means for balancing out or neutralizing the vibratory effects of the drive so that they will not adversely affect the cutting efliciency. In this way the desirable high cutting speeds are readily attainable with resultant desirable and beneficial effects.

Another object of the invention is an improved high speed drive for an electric razor that is characterized by high operating efficiency, dependability, long life and low manufacturing and maintenance costs. Motor driven razors usually employ a pair of contacts that are opened and closed by rotation of the armature and thus periodically energize the motor field to produce rotary motion of the armature. It is virtually impossible however to prevent small particles of hair from getting into the housing and very often a particle will find its way between the contacts. These particles will stick in position and the razor must be taken apart and cleaned before it will operate again. Normally this involves a reasonable expensive service charge in addition to the nuisance to the user. This invention not only avoids the use of contacts which materially reduces consumer maintenance costs, but also eliminates the vibration attendant with conventional vibrator devices. Moreover by reason of its simplified structure the initial cost is low and this low cost is attained notwithstanding the superior qualities of the invention over present razors of which I have knowledge.

Still another object of the invention is a new and improved compact razor of the double or multiple head type that has high cutting efiiciency and high cutting speeds with little vibration of the housing.

A further object of the invention is a new and improved drive for electric razors.

2,814,866 Patented Dec. 3, 1957 The above and other objects and advantages of the invention will become more apparent in the following description and accompanying drawings forming part of this application.

In the drawings:

Fig. 1 is a perspective view of an electric razor embodying the invention;

Fig. 2 is a plan view of the razor of Fig. 1 with the cover removed;

Fig. 3 is a cross sectional view of Fig. 2 taken along the line 3-3 thereof; and

Fig. 4 is a perspective view of the vibrating armature in accordance with the invention.

As indicated above the invention contemplates a razor of conventional size and shape and having a drive mechanism that enables high speed operation without the adverse vibratory effects that directly result from such operation. This end is attained through the use of a balanced driving motor completely enclosed within the housing 12 of the razor 10 as shown in Fig. 1. While the illustrated embodiment of the razor employs two cutting heads, it will become apparent that any number of heads may be simultaneously driven provided they are designed and coordinated with the drive so as to preserve the balanced motion. Tests have indicated that perfect balance though desirable, is not essential since small amounts of vibration will not materially affect the cutting efficiency.

The body 12 of the razor is provided with a removable cover 14 which can be removed to expose the entire drive as shown in Fig. 2. The housing is generally elliptical in shape and in this instance is provided with dual cutting heads 16 and 18 each having two sets of cutting surfaces. Each head is formed of two relatively movable parts 20 and 22 with the outer portion 20 having a central channel 24 and outer depending side members 26 and 28. The flat surfaces bordering the sides of each channel 24 are slotted as shown at 30 to engage the hair to be severed. The cooperating or movable head part 22 is generally U-shaped with the ends of the legs bent outwardly and slotted as shown at 32. These slotted end parts 32 in addition to forming a bearing surface for sliding the member 22 relative to the outer member 20, also severs the hair extending through slots 30 in the outer member 20. With this structure a simple and effective cutting head is provided that is readily adaptable to punch press manufacture.

The drive motor for the cutting heads comprises a pair of balanced vibrating armatures 34 and 34' fastened in opposing relationship to a common mounting bracket 36. Each armature is formed of a flat strip of magnetic material bent at one end to form angle mount 38 (38 in the case of armature 34') and at the other end to form a short transverse member 40 of about one half the width of the body of the armature. Extending upwardly from the member 40 is a relatively rigid member 42 for directly engaging an opening 44 in one head part 22. A magnetic circuit is formed between the two armatures 34 and 34' by providing fiat transverse portions 46 and 46. The member 46 which may be formed integrally with the armature 34 extends transversely to a point spaced from the other armature 34, a distance slightly greater than the vibratory motion to be produced. Similarly, the transverse member 46 of armature 34 extends to a point spaced from the armature 34.

The legs 38 and 38' of each armature may be welded, riveted, or otherwise secured to the bracket 36 which in turn is fastened to the housing 12 by means of screws 48.

The electromagnetic exciting means comprises a coil 50 having a central opening 52 surrounding the transverse armature members 46 and 46' as illustrated in Figs. 2 and 3. The coil may be fastened or otherwise held in position within the case or housing by a series of aligning members 54 which properly position the coil relative to the armatures 34 and 34. Being essentially a vibrator type motor, it may be powered by any suitable type electric current such as 60 cycle current that will afford suflicient high speed operation. The power is directly fed to the coil 50 by a line cord 56 extending through a protective insulating bushing 58 and connected with the coil 50. If desired, it would be possible to arrange the armatures with a pair of contacts to make and break the power applied to the coil and thus enable the device to operate on direct current, or an external converter from D. C. to A. C. may be used.

With the drive motor as described above alternate magnetizing and demagnetizing of the armatures 34 and 34 will cause them to move inwardly and outwardly in opposition one to the other. In so doing, the vibrations thus developed by each armature will balance out so that little motion will be transmitted to the case 12. The vibrating motion of the armatures is transmitted to the respective heads 20 by means of the arms 42 and 42' which are therefore actuated in opposition. Single or multiple head razors may be driven by this device since it is possible, for instance, to drive two heads with one armature and three heads with the other or a single head with but one of the armatures while the other armature remains unloaded. In these cases involving unbalanced loads, the armature having the smaller load may be made slightly heavier or otherwise loaded in order to attain the desired balance.

It is Well known that in vibrating members generally, the vibrating force varies as the square of the vibrating frequency. Conventional razors having rotating armature drives usually operate at about 1000 R. P. M. which is the equivalent of about 16 cycles per see. This low frequency coupled with the mass of the armature and field tends to partially neutralize some of the vibration transmitted to the case. This vibration is however of such a low frequency that the razor can be steadied sufficiently by hand so that the hairs to be severed will follow the vibration of the cutting heads and thus be severed. Increasing the frequency to 60 cycles presents a different problem in that the razor cannot be steadied by hand and the hair will not follow reciprocations of that order. However this invention through its balanced operation utilizes the increased force to effect severance of the hair and at the same time enables a light compact device to be constructed that is substantially free of case vibration.

Because of the complete simplicity of this invention and its adaptability to fabrication by punch press methods it can be made at a fraction of the cost of most present razors and function at materially improved efficiencies. Moreover the elimination of contacts, condensers and the like provides a highly durable and dependable device virtually free of costly and troublesome maintenance.

While only one embodiment of the invention has been shown and described it is apparent that changes, modifications and alterations may be made without departing from the true scope and spirit thereof and that the illustrated embodiment may be adapted to any single or multiple cutting heads.

What is claimed is:

1. An electric razor comprising a housing, a pair of vibrating armatures, at least two shaving heads mounted on said casing, means directly coupling each armature and one of the heads for reciprocation of the heads directly in response to the vibratory motion of the armatures, and an electromagnetic coil surrounding at least part of each armature whereby alternate energization and deenergization of the coil will reciprocate said armatures in opposition one to the other.

2. The combination with an electric razor having at least two cutting heads, of an electrical drive therefor comprising a base, a pair of parallel members of magnetic material secured to and extending from said base, a transverse magnetic member carried by each of said parallel members and extending to a point spaced from the other member, a coil surrounding said transverse magnetic members and means coupling each parallel member with one of said heads.

References Cited in the file of this patent UNITED STATES PATENTS 1,798,756 Redfield Mar. 31, 1931 2,164,425 Rand July 4, 1939 2,240,890 Kavle May 6, 1941 2,245,981 Knopp June 17, 1941 2,259,131 Fleischer et al Oct. 14, 1941 2,261,813 Steinbach Nov. 4, 1941

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