The present invention relates to hair cutting.
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.
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.
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 drawing
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
Gear train 50 is used to adjust the torque at output gear 51 and to match the speed and torque of gear motor 10 and the desired indicating excursion of belt bushing 55 so as to form an ergonomic range. Besides the pointer on top, pointer assembly 44 also carries a small powerful magnet to operate limit switches 16 and 17 which are now implemented as normally closed magnetic reed switches. On/off switch 25 fits between timing belt bushing 55 and pokes through a side switch hole in housing cover 42. While
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.
Also shown in
Although other types of flexing compliant motor couplings can be used, such as a variety of spring type couplings, the preferred coupling between shaft 112 and shaft 142 for reciprocating blade drive is a metal bellows coupling 130 such as those supplied by Servometer of Cedar Grove, N.J. This type of coupling easily fits inside the hollow bellows 120 or foam ring 152 central hole while not interfering with the degrees of freedom of the bellows or foam ring.
The moving blade 206 of the blade set 206, 207 moves horizontally against the stationery blade 207 of the blade set 206, 207 during the cutting of the hair. A spring (not shown) is provided to hold the movable blade 206 and the stationery blade 207 closely adjacent and parallel to each other. The spring is located under a driver 204 which has a driver bracket 201 attached to the blade set 206, 207. The driver 204 is connected to the driver bracket 201, which pivots about driver pin 210 by the force of driver 204. The driver 204 moves the movable blade 206 against the stationery blade 207 to facilitate cutting of the hair on the scalp and skull of the customer. The movable blade 206 is moved closely adjacent and parallel to the stationery blade 207, by an eccentric rotating cam 211 which is powered by the motor M (such as for example the motor M in the other embodiment shown in drawing
The eccentric cam 211 causes the driver 204 to move the movable blade 206 of the blade set 206, 207 adjacent to the stationery blade 207 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 211a of the rotating eccentric cam 211 is positioned between the open U-shaped driver 204 and causes the movement of the movable blade 206 against the adjacent surface of the stationery blade 207.
The U-shaped driver 204 is mounted to a driver bracket 201 which is attached to the blade set 206, 207, and urges the blade set 206, 207 forward or back in an infinitely variable range of motion, limited by the pushing or release of the bushing belt flexor 215 against the pivoted blade set 206, 207. A pivot mount 202 is attached to a pivot plate 205 which pivots the blade set 206, 207 and pivots about a pin 209, which connects the movable pivot plate 205 and blade set 206, 207 to the stationery pivot mount 202, which is mounted to a base. The base housing 208, supports motor “M” within, and the base housing 208, is preferably connected to a three-sided shroud/cover 203, which covers the two sides and front of the pivoting mechanisms in front of the pivotable blade set 206, 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.
This application is a continuation-in-part of application Ser. No. 16/547,535, filed on Aug. 21, 2019, which '535 application is a continuation of application Ser. No. 15/677,018, filed Aug. 15, 2017, now U.S. Pat. No. 10,391,646 B2 issued Aug. 27, 2019, which '018 application is a continuation of application Ser. No. 14/622,554 filed Feb. 13, 2015, now U.S. Pat. No. 9,731,424 issued Aug. 15, 2017, which '554 application is a continuation-in-part of application Ser. No. 13/727,274, filed on Dec. 26, 2012, now U.S. Pat. No. 9,352,476 issued May 31, 2016, which '274 application is a divisional of application Ser. No. 12/592,537, filed on Nov. 24, 2009, now U.S. Pat. No. 8,341,846 issued Jan. 1, 2013, which '018, '554, '274 and '537 applications are incorporated by reference herein. Applicant claims priority under 35 U.S.C. § 120 therefrom. Application Ser. No. 12/592,537 is based upon provisional application Ser. No. 61/117,434 filed Nov. 24, 2008, which application is also incorporated by reference herein. Applicant claims priority under 35 USC§ 119(e) therefrom.
Number | Date | Country | |
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61117434 | Nov 2008 | US |
Number | Date | Country | |
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Parent | 12592537 | Nov 2009 | US |
Child | 13727274 | US |
Number | Date | Country | |
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Parent | 15677018 | Aug 2017 | US |
Child | 16547535 | US | |
Parent | 14622554 | Feb 2015 | US |
Child | 15677018 | US |
Number | Date | Country | |
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Parent | 16547535 | Aug 2019 | US |
Child | 17546841 | US | |
Parent | 13727274 | Dec 2012 | US |
Child | 14622554 | US |