HAIR CLIPPERS WITH FLEXING ELECTRICALLY ADJUSTABLE BLADES

A flex clipper provides a feature to help the cutting blade set float more effortlessly by adjusting automatically to the contours of a client's head to prevent getting stuck and causing cuts and irritation to the scalp. The hair clipper preferably also uses a self-contained motor-driven pivotable adjustment mechanism to adjust the relative position of the stationary and reciprocating blades of a common type of blade set. One or more on/off switches operable by the thumb of the hand holding the clipper to afford a barber total automatic adjustment with the clipper itself in an on or off condition.

FIELD OF THE INVENTION

The present invention relates to hair cutting.

BACKGROUND OF THE INVENTION

Electrically operated hair clippers have been used for many years. Some of the commonly available models have a manual lever on the side to incrementally adjust the relative position between the stationary and the reciprocating blades in a blade set to adjust the minimum length of hair that is being clipped. Other prior art patents show infinite adjustability over a range. The prior art does not reveal motor-powered continuous adjustability of the blade set which affords the barber the ability to perform the adjustment even during the clipping activity by simply activating a switch and/or having a flexing compliance blade set that adjusts around the contours of the scalp of a flex clipper is described which, in addition to the aforementioned powered hair cutting length adjustment feature, provides an additional feature to help the cutting blade set float more effortlessly by adjusting automatically to the contours of a client's head, to prevent the blade set getting stuck and causing cuts and irritation to the scalp of the customer.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a flexing hair clipper with a flexing cutting blade adjuster which adjusts automatically to the contours of a client's head to prevent the blade set getting stuck and causing cuts and irritation to the scalp.

It is also an object of the present invention to provide a hair clippers device with infinitely variable blade distances from the scalp of the patron.

Other objects which become apparent from the following description of the present invention.

SUMMARY OF THE INVENTION

The hair clippers of this invention use a self-contained motor-driven adjustment mechanism to adjust the relative position of the stationary and reciprocating blades of a common type of blade set, preferably with a flexing blade set to adjust to the contours of the scalp of the customer having his or her hair being cut and trimmed.

While other on/off switches can be used, preferably two momentary switches operable by the thumb of the hand holding the clipper afford a barber total automatic adjustment with the clipper itself in an on or off condition. There is no need for two-handed fidgeting or selection of only a few discrete increments of length adjustment as with the commonly available models. Since the small gear motors used for the adjustment are brush type or brushless permanent magnet motors which are operated by direct current, the adjustment feature is most compatible with cordless clippers already using an on-board DC source in the form of a re-chargeable battery to drive the reciprocating blade. The invention will be described as a modification of a cordless clipper, although AC driven corded type clippers can also be modified with this feature by the addition of an on-board AC to DC power supply for the adjustment motor.

In the first embodiment, a modified blade set is used such that a gear rack is attached to the stationary blade. It is engaged with a worm gear pinion driven by a low-speed gear motor through a reversible drive circuit. Either limit switches, limit sensors, or over-current sensors are used to disable the adjustment motor at either the long or short hair end limits. The motor then can only be driven in the opposite direction.

In the second embodiment, a conventional blade set is used. The modification is such that a motor-driven final gear replaces the manual handle thereby retaining the original mechanism (of any type) that is used to move the stationary blade relative to the reciprocating blade in the conventional blade set. A timing belt bushing couples a rear mounted adjustment motor to a front side-mounted gear train coupled to the shaft of the blade shifting mechanism. Attached to the timing belt bushing for linear back and forth excursions is a magnet with a pointer. The magnet is used to operate two normally closed magnetic reed switches placed at the opposite distal ends of the permissible excursion thereby serving the limit switch function. The pointer moves over a tri-colored linear scale viewable by the barber from the top of the hair clipper; this quickly indicates the hair length setting. A plastic housing cover over the adjustment motor at the back and over the timing belt bushing and gear train at the side encloses the entire compact mechanism.

In a third embodiment, a flex clipper is described which, in addition to the aforementioned powered hair cutting length adjustment feature, provides an additional feature to help the cutting blade set float more effortlessly, by adjusting automatically to the contours of a client's head to prevent getting stuck and causing cuts and irritation to the scalp.

To achieve this automatic adjustment, the blade set with motor driven length adjuster in now housed in a separate module. Compliance is introduced between this module and the main housing of the flex clipper. The blade set can now tilt a small amount in any direction to automatically adjust to the local scalp contours while the cutting process is controlled as usual by grasping the main housing. The rigid attachment of the blade set to the housing is replaced by a flexing compliant attachment. Two methods are described, one is by using a large diameter short bellows while the other method uses a short length (a ring) of thick-walled elastomeric foam tubing which provides similar function.

Both flexing compliant attachments permit tilting and a small amount of linear axial movement between blade set and main housing, but both resist any relative rotational movement between blade set and main housing. This rotational resistance ensures good control of the blade set by keeping the cutting edge always aligned with the top surface of the housing (as in a normal rigid attachment) except for any minor local tilting. This rotational stiffness must also resist the driving torque of the motor driving the reciprocating cutter blade.

Since the drive motor for the reciprocating cutter blade is in the main housing and the crank mechanism and blade set are in a separate module, a flexing compliant motor coupling that can follow any blade movements relative to the main housing is required. A metal bellows coupling of a diameter which fits inside the hollow interior of coupling bellows or foam ring is used. To keep the mass and size of the forward blade set module low, a modified cutting length adjuster mechanism is used; for example, in one embodiment, it uses a miniature stepper motor with a lead screw. The powering and control cable from the stepper motor driver in the main housing is also guided through the hollow interior of the coupling member.

The flexing compliance (i.e., spring characteristics) of the coupling member as well as the damping characteristics can be determined by the geometric design and material selected. The proper “feel” can be achieved through simulation and actual prototype testing known to those skilled in the art of hair clippers technology. While the damping characteristics are not as important as the compliance, they determine the smoothness and sound deadening performance. For the bellows, a wide variety of thermoplastic elastomers (TPE's) or rubbers can be used. By using thin material crossection, even normally rigid plastics such as nylons or polypropylene can be used. Geometric design of the bellows includes overall length and diameter as well as number and shape of convolutions. By using filled TPE's or alloys of rubber/TPE a wide variety of damping characteristics can be designed in. Foamed rubbers or TPE's can be used for a foam ring coupling; other parameters that can be selected include type of cell (open or closed) and size of the cells. Material selection must also pay attention to longevity and compatibility with lubricants and hair conditioners.

In a further alternate embodiment, the blade set is also capable of flexing around the contours of the customer's hair, scalp and skull. Power is applied to the blade set by a conventional motor within the handset housing of the clippers. The motor may be activated by conventional tap switches, rotating wheel switches, or other manually activated switches. Instead of a flexible cylindrical neck, as in the aforementioned flexing embodiment, in this embodiment, the blade set is pivotable upward from a first position to a second position, whereby the blade set is controlled by a semi-rigid flexible belt bushing piece, i.e. known as a “flexor” which is positioned on the bottom of the clippers housing and which includes a semi-rigid flexible curved distal end which biases against a portion of the blade set to urge the blade set to move around the contours of the customer's hair, scalp and skull during the process of a hair cutting. The flexor counteracts the propensity of the upwardly pivoted blade set to pivot outwardly and holds the blade set in a mid-point position so that the blade set can push in or push out while moving over the three-dimensional curvature of the hair, scalp and skull of the customer. The flexor gently pushes the pivoted blade set to a flexing motion or a relaxed motion against the hair, scalp and skull of the customer. The moving blade of the blade set moves horizontally against the stationery blade of the blade set during the cutting of the hair. A spring is provided to hold the movable blade and the stationery blade closely adjacent and parallel to each other. The spring is located under a driver which has a driver bracket attached to the blade set. The driver moves the movable blade against the stationery blade to facilitate cutting of the hair on the scalp and skull of the customer. The movable blade is moved closely adjacent and parallel to the stationery blade, by an eccentric rotating cam which is powered by the motor (such as for example the motor M in the other embodiment shown in drawingFIG. 8) inside the housing of the hair clippers. The eccentric cam causes the driver to move the movable blade of the blade set adjacent to the stationery blade in subsequent left and right sets of multiple parallel movements, during cutting of the hair of the scalp and skull of the customer. The rod of the rotating cam is positioned between an open U-shaped driver and causes the movement of the movable blade against the adjacent surface of the stationery blade. The U-shaped driver is mounted to a driver bracket which is attached to the blade set, and urges the blade set forward or back in an infinitely variable range of motion, limited by the pushing or release of the flexor against the pivoted blade set. A pivot mount is attached to a pivot plate which pivots the blade set and pivots about a pin, which connects the movable pivot plate and blade set to the stationery pivot mount, which is mounted to a base. The base is preferably connected to a three-sided shroud which covers the two sides and front of the pivoting mechanisms in front of the pivotable blade set.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2show two views of a conventional cordless electric hair clipper1with on/off switch3, conventional blade set2, and side manual incremental adjusting handle4. The detents5engage handle4to set the minimum hair cutting length at one of the selections.

FIG. 3shows the mechanism which uses gear motor10driving worm gear pinion11to perform an adjustment of stationary blade14relative to reciprocating blade13in blade set12. A gear rack15subassembly is attached to blade14and engages pinion11. Also shown in this view are limit switches16and17at the longest and shortest settings respectively.FIGS. 4 and 4Ashow clipper housing20with the adjustment feature. Conventional on/off switch25connected to clipper motor24(shown schematically as an encircled “M”) is at one side while momentary (or “tap”) switches21and22on the top surface are used to energize gearmotor10in a direction toward longer settings or shorter settings respectively. Gearmotor10is enclosed in descending housing26, which descends below clipper housing20. WhileFIGS. 3, 4 and 4Ashow a worm gear, it is anticipated that other gears may be used, such as rack and pinion gears or other gears known to those skilled in the art.

FIG. 5is a wiring diagram for the first embodiment ofFIGS. 3 and 4wherein gearmotor10is a simple brush type permanent magnet type driven by a common “H-bridge” drive module35. Battery30is used primarily to power clipper motor24through on/off switch25. It is also used as the power source for the adjustment feature. Drive module35has two direction inputs for clockwise and counterclockwise operation, an “ON” input, and power input and motor output connections as shown. In operation, if normally open switch22is pushed, a signal will flow through normally closed limit switch17energizing the ON input through isolation diode36; motor10will be driven clockwise until either switch22is released or limit switch17is opened at the end of the excursion. Similarly, if switch21is pushed, counterclockwise operation is achieved through limit switch16and isolation diode37. Once a limit switch is opened, motor10can only be driven in the opposite direction until the open limit switch is again closed.

FIGS. 6 and 7show top and side views of the second embodiment of motor-driven minimum hair length adjustable hair clippers. The same circuit shown inFIG. 5is completely applicable to this embodiment as well. The same momentary (“tap”) switches21and22are used to control motor10which is now placed at the back end of hair clipper40. Except for the addition of switches21and22, the housing41and internal mechanism is identical to that of the prior art cordless clipper shown inFIGS. 1 and 2. In this embodiment, a conventional blade set12and internal blade adjusting mechanism is used. The feature of this embodiment couples through the shaft formerly engaged with a manual handle4. This is shown at the center of output gear51. In the top view ofFIG. 6, housing cover42is a plastic shell used to enclose the feature mechanism. InFIG. 7, this cover42is removed to reveal the mechanism; the position is shown in dashed lines. On the top edge of cover42is a tri-colored strip43with green region45denoting the long settings, yellow region46denoting medium length settings, and red region47denoting short settings. This scale is meant to be read relative to the position of pointer assembly44which is attached to timing belt bushing55transmitting power and torque from pulley57mounted on motor10to pulley56attached to the input gear of gear train50.

Gear train50is used to adjust the torque at output gear51and to match the speed and torque of gear motor10and the desired indicating excursion of belt bushing55so as to form an ergonomic range. Besides the pointer on top, pointer assembly44also carries a small powerful magnet to operate limit switches16and17which are now implemented as normally closed magnetic reed switches. On/off switch25fits between timing belt bushing55and pokes through a side switch hole in housing cover42. WhileFIGS. 6 and 7show a particular embodiment for an exterior mounted embodiment, it is anticipated that other exterior mounted embodiments may be used, such as those known to those skilled in the art.

While this third embodiment will be described as for a flex hair clipper with both powered hair cutting length adjustment as well as flexing compliance introduced between the main housing and blade set module, it should be noted that the flexing compliance feature to permit the blade set to automatically adjust to scalp contours and irregularities can be afforded to hair clippers without the powered hair cutting length adjustment. If the latter feature is not implemented, the blade set module will just contain the blade set and crank mechanism with coupling to the drive motor in the main housing which operates the reciprocating cutting blade; there would not be a cutting length adjustor motor, adjuster mechanism attached to the comb plate, nor a housing for the adjuster motor.

FIG. 8shows an exploded view of the major components of this embodiment. Flex clipper100has main housing110which contains drive motor116with shaft112which drives the reciprocating cutter blade113, rechargeable battery135(unless it is an AC driven corded model), and an electronic driver module160for the hair cutting length adjuster motor145located in blade set module140at the left of theFIG. 8. Rigid coupling ring118is attached at the coupling end of housing110. Blade set module140carries adjustable comb plate114, reciprocating cutter blade113, internal crank mechanism143for reciprocating cutter blade113, drive shaft142for crank mechanism143, housing144for internal hair length adjustment motor145, internal hair length adjustment direct comb plate mechanism114(shown inFIG. 12), and a rigid coupling ring146.

Also shown inFIG. 8is molded compliant bellows120with integral mounting rings126and128is shown between blade module140and main housing110, which it couples together. Metal bellows130couples drive motor116in main housing110and crank drive shaft142in blade module140. Cable148powers and controls motor145for hair cutting length adjustment from electronic step driver module160contained in housing144; it is passed through the hollow interior of bellows120.

FIG. 9shows an assembled flex clipper100showing tap switches21and22for adjusting cutting length and clipper operating switch25. A thumb operable reverse direction wheel23can also be optionally used. Bellows120is shown coupling blade module140to housing110in a flexing compliant fashion. The length of bellows120as shown inFIGS. 8 and 9may be shorter than shown based on the design and materials of the bellows. Bellows integral collars126and120fit over fixed collars146and118on blade module140and housing110respectively. Fasteners, such as self tapping screws, are used to secure the bellows collars to collars146and118which preferably have transverse holes in registration.

FIG. 10shows an alternate embodiment of an assembly of resilient foam ring152with attached metal collars154, which are adhesively attached or vulcanized as appropriate to the collar material. The assembly ofFIG. 10can be used in lieu of custom molded bellows120. Depending on many variables known to those skilled in the hair clippers technology, such as desirable product life, product price point, manufacturing cost, performance, volume, and materials used, either the bellows or the foam ring assembly may be the better choice.

FIG. 11shows a perspective view of the foam ring prior to attachment of coupling rings154.

Although other types of flexing compliant motor couplings can be used, such as a variety of spring type couplings, the preferred coupling between shaft112and shaft142for reciprocating blade drive is a metal bellows coupling130such as those supplied by Servometer of Cedar Grove, N.J. This type of coupling easily fits inside the hollow bellows120or foam ring152central hole while not interfering with the degrees of freedom of the bellows or foam ring.

FIG. 12shows the simple direct comb plate114adjustment mechanism which includes preferably stepper motor145, and a fastening mechanism, such as, for example, threaded bracket149and fine lead screw147. Although other methods can be incorporated, a stepper motor145is preferred to a DC gearmotor due to size and complexity. At about 6 mm diameter and 9.5 mm long, a FDM0620 stepper motor from Micromo of Clearwater, Fla. is very compact and is driven with 20 steps per revolution to drive lead screw147.

FIG. 13shows a schematic diagram for the flex clipper. It is noted that no limit switches are required because step motors can just “lose steps” with no damage when a hard stop is encountered. Tap switches22and24determine the direction of rotation of stepper motor145by supplying the proper sequence of steps from step driver module160over cable148. Reciprocating blade motor116for reciprocating cutter blade113is directly powered through switch25. Battery135(or equivalent DC power supply for corded versions) supplies power to both reciprocating blade motor116, and to stepper motor145, through step driver module160.

FIGS. 14-23Dshow a further flexing hair clipper200. In a further alternate embodiment, the blade set206,207is also capable of flexing around the contours of the customer's hair, scalp and skull. Power is applied to the blade set206,207by a conventional motor M (as inFIG. 17) within the handset housing208of the hair clippers200. The motor M may be activated by conventional tap switches, rotating wheel switches, or other manually activated switches (not shown). Instead of a flexible cylindrical neck, as in the aforementioned flexing embodiment ofFIGS. 8-13, in this embodiment, inFIGS. 14-23D, the blade set206,207is pivotable upward from a first position to a second position, whereby, as shown inFIG. 18, the blade set206,207is controlled by a semi-rigid flexible belt bushing piece215, i.e. known as a “flexor”215which is positioned on the bottom of the clippers housing208. The flexor215includes from top to bottom a series of joined, parallel rippled wave-like rounded peaks215cand valleys215d. The flexor215includes a semi-rigid flexible curved distal end215a, attached to a linear proximal body portion215b. The semi-rigid flexible curved distal end215abiases against a portion of the blade set206,207to urge the blade set206,207to move around the contours of the customer's hair, scalp and skull during the process of a hair cutting. The flexor215counteracts the propensity of the upwardly pivoted blade set206,207to pivot outwardly and holds the blade set206,207in a mid-point position so that the blade set206,207can push in or push out while moving over the three-dimensional curvature of the hair, scalp and skull of the customer. The semi-rigid flexible curved distal end215aof the flexor215gently pushes the pivoted blade set206,207to a flexing motion or a relaxed motion against the hair, scalp and skull of the customer. The straight linear proximal body portion215of the flexor215stabilizes the flexor215against the body of the hair clipper200.

The moving blade206of the blade set206,207moves horizontally against the stationery blade207of the blade set206,207during the cutting of the hair. A spring (not shown) is provided to hold the movable blade206and the stationery blade207closely adjacent and parallel to each other. The spring is located under a driver204which has a driver bracket201attached to the blade set206,207. The driver204is connected to the driver bracket201, which pivots about driver pin210by the force of driver204. The driver204moves the movable blade206against the stationery blade207to facilitate cutting of the hair on the scalp and skull of the customer. The movable blade206is moved closely adjacent and parallel to the stationery blade207, by an eccentric rotating cam211which is powered by the motor M (such as for example the motor M in the other embodiment shown in drawingFIG. 8) inside the housing208of the hair clippers200. Motor “M” is powered by a power source being one of a battery within the main hair clipper housing208or an AC driven corded power source, similar to battery135ofFIG. 8herein, (or equivalent DC power supply for corded versions) which supplies power to both reciprocating blade motor “M”, or, as also shown inFIG. 8, to a stepper motor145, through a step driver module160.

The eccentric cam211causes the driver204to move the movable blade206of the blade set206,207adjacent to the stationery blade207in subsequent left and right sets of multiple parallel movements, during cutting of the hair of the scalp and skull of the customer. The rod211aof the rotating eccentric cam211is positioned between the open U-shaped driver204and causes the movement of the movable blade206against the adjacent surface of the stationery blade207.

The U-shaped driver204is mounted to a driver bracket201which is attached to the blade set206,207, and urges the blade set206,207forward or back in an infinitely variable range of motion, limited by the pushing or release of the bushing belt flexor215against the pivoted blade set206,207. A pivot mount202is attached to a pivot plate205which pivots the blade set206,207and pivots about a pin209, which connects the movable pivot plate205and blade set206,207to the stationery pivot mount202, which is mounted to a base. The base housing208, supports motor “M” within, and the base housing208, is preferably connected to a three-sided shroud/cover203, which covers the two sides and front of the pivoting mechanisms in front of the pivotable blade set206,207.

In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.

It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.