Electric hair cutting appliances

An electric hair cutting apparatus including a casing and a cutter unit secured to the casing.

TECHNICAL FIELD

This invention relates to electric hair cutting appliances.

BACKGROUND

WO 00/37225 describes a hair cutting apparatus including a cutter head mounted on a housing of the apparatus for pivotal motion about an axis. A cutting comb of the cutter head has two associated cutting blades that are adapted to be coupled to a drive element of a drive mechanism. Each of the cutting blades is dependent upon the pivot position of the cutter head. One of the cutting blades is generally disengaged so that only one cutter unit is driven at a time. The axis about which the cutter head is pivotal extends parallel to the cutting edges of the cutting combs or cutting blades. The cutter head is carried at either end in a fork-shaped socket in the housing of the hair cutting apparatus. The pivot axis extends centrally relative to the two cutting elements. Coupling elements are connected to cutting elements of the cutting blades. The coupling elements, for engagement with an eccentric drive, include sloping enlargements to facilitate introduction of the eccentric device in various operating positions. It is necessary to turn off the drive before pivoting the cutter units.

US 2003/0106219 A1 describes another hair cutting apparatus that has a pivotal cutter head with two cutter units, a narrower one and a wider one. The two ends of the cutter head are carried in a casing, with the pivot axis extending normal to a plane formed by the two cutter units. The pivot axis extends centrally relative to the two cutting elements. In order to enable the cutter head to be rotated relative to the casing with the motor turned on, a coupling device is provided. The coupling device temporarily interrupts the driving relationship between motor and shaving unit.

SUMMARY

In certain aspects of the invention, an arrangement is provided that enables an operator of a hair cutting apparatus to rotate a cutter unit about an axis of rotation using the thumb of his or her hand that grips the apparatus. In such aspects, the handling comfort of the hair cutting apparatus can be improved relative to conventional hair cutting apparatuses.

In some embodiments, a drive mechanism for actuation of the cutter unit is disposed so as to act upon a shaving element to be moved (e.g., oscillated). In certain embodiments, the drive mechanism is alternatively or additionally disposed to act upon a component part connected to the shaving element in the proximity of an axis of rotation. In certain embodiments, it is possible to pivot the cutter unit with the drive turned on. This can, for example, help to improve handling of the apparatus.

In certain embodiments, the cutter unit includes a cutting comb and an associated cutting blade, which enable the cutter unit to be used as a hair trimmer or a longhair cutter. In some embodiments, the cutting comb and the cutting blade include teeth with flanks that form the cutting edges.

In some embodiments, two diametrically opposed cutter units are mounted on a carrier body. In such embodiments, the carrier body can be rotated about an axis of rotation extending eccentrically between two cutter units. Rotation of the carrier body relative to a casing of the hair cutting apparatus enables the user to place the desired cutter unit in a working or operative position.

In certain embodiments, two different types of cutter units (e.g., longhair cutter units) are provided. Each of the cutter units can, for example, be placed in an operating state in a predetermined position relative to the casing of the hair cutting apparatus. In some embodiments, the cutter units have widths that differ from one another. The cutter units can, for example, include a cutting comb and an associated cutting blade of different widths. Hence a longhair cutter for shortening longer hair, which has a relatively wide dimension, can be provided along with a relatively narrow contour shaper for cutting precision contours. The relatively wide cutter and the relatively narrow shaper can be brought into respective working positions by pivoting the carrier body. In certain embodiments, the two cutter units are asymmetrically positioned relative to the common axis of rotation. In some embodiments, it is possible to pivot the cutter units (e.g., the relatively wide cutter and/or the relatively narrow shaper) into a working position that is particularly exposed relative to the casing. In such embodiments, the operator can obtain a good view of the working area for the relatively wide cutter and/or the relatively narrow shaper, without substantial interference by the casing or related parts.

Advantageously, the two cutter units can be actuated by a common drive arrangement, which can help to simplify the design and reduce the effort required to assemble the cutting apparatus.

In certain embodiments, the hair cutting apparatus further includes a shorthair cutter unit. In some embodiments, the carrier body is rotatably mounted on the outside (e.g., on an outside surface) of the casing of the hair cutting apparatus equipped with the shorthair cutter unit. In these embodiments, the shorthair cutter unit can be used to produce a relatively close shave, and the cutter unit(s) carried by the carrier body may be designed as longhair cutters of differing widths. In certain embodiments, the cutter unit(s) secured to the carrier body can advantageously be pivoted into their respective operating positions with one hand.

In some embodiments, both the shorthair cutter unit and the cutter unit(s) mounted on the carrier body are driven by a common motor.

In certain embodiments, the carrier body is linearly displaceably mounted on the casing. In such embodiments, the carrier body can be linearly displaced relative to the casing. Such arrangements can help to enable operating positions that are spaced from each other by a wide distance to be selected in a simplified manner.

For enhanced handling comfort, it is possible for the linear and/or rotary movements of the carrier body to be performed by an electric motor.

In some embodiments, the hair cutting apparatus improves the ease of operation of the cutter unit(s) rotatably mounted on the casing. In certain embodiments, for example, the hair cutting apparatus can be operated with only one hand.

DETAILED DESCRIPTION

The perspective view ofFIG. 1shows a dry shaver1with a casing2and a shorthair cutter unit3. The shorthair cutter unit3includes an outer cutter4constructed in the form of a shaving foil beneath which an undercutter (not shown) is moved to and fro in oscillating fashion. The casing2accommodates a drive motor (not shown) and, where applicable, electric storage cells (not shown) and/or a power supply (not shown) and charging unit (not shown) for the supply of power to the drive motor. Arranged on a rear side of the casing2is an on/off switch5. The on/off switch5controls the supply of power to the drive motor which, when turned on, causes the undercutter of the shorthair cutter unit3to oscillate. The motor also drives a drive element6protruding from the casing2. In this arrangement, like the undercutter, the drive element6is driven to oscillate parallel to the transverse axis of the dry shaver.

Arranged on the front side of the casing2is a slide switch7on which a carrier body8is mounted. First and a second longhair cutter units9and10, respectively, are secured to the carrier body8, as shown inFIG. 1. The slide switch7is movably mounted to the casing2for displacement along the longitudinal axis of the casing2. The carrier body8in turn is pivotably mounted on the slide switch7for pivotal motion about an axis of rotation11that extends substantially perpendicularly to the front side of the casing2. The linear displaceability of the slide switch7on the casing2can be accomplished using any of various techniques, such as slide-type longitudinal guideways.

The construction of the module assembly, which includes the slide switch7and the carrier body8is illustrated inFIGS. 7-9. The slide switch7includes a backing plate12and a cover shell13provided with recessed grips14. The backing plate12serves to mount the switch longitudinally displaceably on the casing2. A U-shaped spring15is provided between the backing plate12and the cover shell13. A double lever16is mounted on the backing plate12. The backing plate12has a mounting point17to which the double lever16can be mounted for rotation on its central swivel bearing18. A drive pin19is provided at the upper end of the double lever16. The drive pin19extends transversely in the direction of the cover shell13. Coupling projections20are provided at the lower end of the double lever16. The coupling projections20extend transversely in a direction opposite to that of the drive pin19, i.e., toward the casing2.

In this arrangement, the coupling projections20pass through an oval aperture21provided in the backing plate12. The upper third of the cover shell13includes a circular cutout22, which, in an assembled state, surrounds the drive pin19. The cutout22extends concentrically about the drive pin19when the double lever16is in the intermediate position illustrated inFIGS. 7-9. The cutout22is bounded by a circumferential collar23that serves as a support for the mounting plate24. The mounting plate24has a circular cutout25of a diameter corresponding to (e.g., substantially equal to) the diameter of the cutout22of the cover shell13. The mounting plate24and the cover shell13are pivotally connected with each other via a swivel joint26. The swivel joint26includes a bearing ring27on which two diametrically opposite and axially extending domed mounting members28are formed. While the mounting plate24engages the collar23on the front side of the cover shell13, the bearing ring27of the swivel joint26contacts the collar23on the rear or inner side of the cover shell13. In this arrangement, the domed mounting members28extend through both the circular cutout22of the cover shell13and the circular cutout25of the mounting plate24, combining with a circumferential shoulder to centrally locate the cover shell13and the mounting plate24.

As shown inFIGS. 1 and 9, the carrier body8includes a cover29and the mounting plate24. The domed mounting members28of the swivel joint26each have two axially extending bores to receive corresponding fastening pins provided on the inside of the cover29of the carrier body8.

Referring toFIGS. 7-9, the two longhair cutter units9and10are attached to the carrier body8. The longhair cutter units9and10are held between the mounting plate24and the cover29of the carrier body8and are adapted to be driven by the drive pin19passing through the swivel joint26. The first longhair cutter unit9includes a stationary cutting comb30and a linearly oscillating cutting blade31. Each of the cutting comb30and the cutting blade31has a straight row of teeth. Flanks of the cutting teeth form cutting edges to cut hairs captured between the teeth. The cutting comb30has elongated holes32into which guide pins33extend, forming a linear bearing. The cutting blade31includes a coupling member34that has a hole mount35for receiving the drive pin19. The hole mount35is constructed as a vertically extending oblong hole.

The second longhair cutter unit10, whose width can be less than half the width of the first longhair cutter unit9, similarly includes a stationary cutting comb36and a cutting blade37driven to oscillate in pivotal fashion. Tooth rows of the cutting comb36and the cutting blade37are of generally rounded construction, their radius of curvature lying roughly about a pivot point38of a drive lever39formed on the cutting blade37. At the end of the drive lever39remote from the cutting blade37is another hole mount40constructed as a vertically extending oblong hole for receiving the drive pin19. The pivot point38is formed by a bearing pin41extending from the inside of the cover29. The two cutting combs30and36are fastened to the inside of the cover29.

The cutting blades31and37are arranged between their associated cutting combs30and36, respectively, and the mounting plate24. The teeth of the associated cutting combs generally protrude only a small amount over the blades' rows of teeth, which can help to reduce the risk of injury to a user by the driven components.

As soon as the double lever16is set into oscillating motion as will be described below, the two cutting blades31and37are oscillated because they are both in engagement with the drive pin19. By swiveling the carrier body8about the axis of rotation11, one of the two longhair cutter units9or10can be moved into a working position. It is generally not necessary to turn off or disengage the drive when rotating the carrier body8about the axis of rotation because the drive pin19oscillating about the swivel bearing18, due to its central location relative to the swivel joint26, can continue to drive the two cutting blades31or37or can move freely within its hole mounts35and40.

When the carrier body8is swiveled through 90° from the initial position shown inFIG. 8, the amplitude of the movements of the cutting blades31or37will decrease to zero, because the dimensions of the hole mounts35and40coincide with the oscillating motion of the drive pin19which moves freely to and fro within the hole mounts35and40. If the swiveling motion of the carrier body8continues, that is, from 90° to 180°, the oscillation amplitude of the cutting blades31and37will increase again until, upon being swiveled through 180°, they have again reached their maximum value.

To lock the carrier body8in the two working positions shown inFIGS. 1-6, two radially projecting cams42are provided on the bearing ring27of the swivel joint26, as shown inFIG. 9. The cams42, in these working positions, make locking engagement with notches43provided on the legs of the U-shaped spring15. Because the swivel joint26rotates with the carrier body8, on rotation of the carrier body8, the cams42are able to move freely into and out of locking engagement with the notches43through elastic deformation of the U-shaped spring15.

FIGS. 1 and 2show the dry shaver1in its initial position. Actuation of the on/off switch5sets the motor (not shown) in operation and drives the undercutter (not shown) beneath the outer cutter or shaving foil4in an oscillating manner. At the same time, the drive element6, which projects a small amount from the casing2, oscillates transversely to the casing2, i.e., oscillates in the same direction as the undercutters. In this state, the shorthair cutter unit3is actuated so that it is able to cut hair, and the two longhair cutter units9and10are not driven, e.g., the cutting blades31and37of the cutter units9and10, respectively, experience substantially no movement relative to their associated cutting combs30and36, respectively. The first longhair cutter unit9, in this arrangement, lies at a level below the shorthair cutter unit3so that a clear view of the latter's working area can be achieved.

Referring toFIGS. 3 and 4, by sliding the slide switch7upwards relative to and lengthwise to the casing2by a distance X, the drive element6enters the space between the coupling projections20of the double lever16. After sliding the distance X, which is the distance between stops on the casing2and on the slide switch7, the double lever16, driven by the drive element6, oscillates about the mounting point17, i.e., the swivel bearing18. In this second operating state of the hair cutting apparatus1, the cutting blade31performs an oscillatory linear motion relative to the cutting comb30, and the cutting blade37performs an oscillatory pivotal motion relative to the cutting comb36about the pivot point38. In this second operating state, the first, relatively wide longhair cutter unit9is directed upwards, extending over and beyond the shorthair cutter unit3. The first longhair cutter unit9, in this position, can be used to remove or precut relatively long hair which subsequently can be better captured and shaved off by the shorthair cutter unit3if desired. Owing to the exposed position of the first longhair cutter9, a clear view of the first longhair cutter unit9can be achieved and thus the ease of use the apparatus can be increased.

FIGS. 5 and 6illustrate a third operating state in which the second longhair cutter unit10is moved into a working position. In this operating state, the slide switch7is in its upper switch position as shown inFIGS. 3 and 4. In contrast to the second operating state, the carrier body8and the cutting elements attached to the carrier body8are rotated about the axis of rotation11through 180° relative to the side switch7or the casing2. In this manner, the second, relatively narrow longhair cutter unit10can be rotated to its working position, as illustrated by graphic44. The relatively narrow longhair cutter unit10can serve as a precision shaper, e.g., for shaping beards. Considering that the axis of rotation11is in an eccentric relationship to the position of the two longhair cutter units9and10and considering further that the distance between the second longhair cutter unit10and the axis of rotation11is about double the distance between the axis A rotation11and the first longhair cutter unit9, in the third operating state shown inFIGS. 5 and 6the second longhair cutter unit10protrudes over and beyond the shorthair cutter unit3a more significant amount than does the first longhair cutter unit9in the second operating state illustrated inFIGS. 3 and 4. As a result, when using the second longhair cutter unit10, the operator can have a substantially clear view of the cutting operation.

In some embodiments, the pivotal movement of the carrier body8and/or the longitudinal displacement of the slide switch7can be performed by control drives that the operator can control via appropriate switching elements.