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Publication numberUS3812389 A
Publication typeGrant
Publication dateMay 21, 1974
Filing dateNov 10, 1972
Priority dateNov 10, 1972
Publication numberUS 3812389 A, US 3812389A, US-A-3812389, US3812389 A, US3812389A
InventorsBowerman L
Original AssigneeOster Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hair clipper with improved blade driving means
US 3812389 A
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Description  (OCR text may contain errors)

United States Patent [191 Bowerman 1451 May21, 1974 HAIR CLIPPER WITH IMPROVED BLADE DRIVING MEANS [75] Inventor: Leonard E. Bowerman, Fairfield,

Conn.

1,810,469 6/1931 Dremel 310/29 Primary Examiner-.1. D. Miller Assistant Examiner-Robert J. Hickey Attorney, Agent, or FirmGeorge R. Clark; Neil M. Rose; John S. Pacocha 15 1 ABSTRACT A hair clipper having a vibratory motor with an armature that is pivotally supported by an upright bearing is disclosed. A pair of torsion springs encircle the vertical axis of the bearing. One end of each spring is inserted into apertures in the armature and the other end of each spring bears against the housing of the clipper to bias the armature to a central position. The blade drive pin is integrally molded into the armature and a plastic ball and socket drive member is carried by the pin. The drive member is spring biased against a plastic drive shoe, which is removably secured to the upper cutting blade of the clipper. The drive shoe and the housing of the clipper have mating guiding sur- HAIR CLIPPER WITH IMPROVED BLADE DRIVING MEANS BACKGROUND OF THE INVENTION The present invention relates to electric hair clippers and more specifically, to an electric hair clipper that is driven by an oscillating armature type of electric motor having improved blade drive provisions. Several years ago, the assignee of the present invention introduced a hair clipper utilizing a vibratory oscillating armature type of electric motor which was especially designed for use by professional barbers. This previously introduced hair clipper of the assignee is described in U.S. Pat. No. 3,493,793, patented Feb. 3, 1970 on an application of Paul W. Niemela which was filed July 5, 1968. The present invention is described with reference to an embodiment which utilizes a motor that is similar to that of the Niemela Patent, but it is not intended that the invention be limited solely thereto.

The hair clipper of the Niemela Patent employed a vibratory motor that had a high power output per unit weight. Thus, the weight of a hair clipper could be reduced significantly by using this motor so as to relieve the fatigue of the barber who used the hair clipper relatively constantly during the working portion of his day. The hair clipper of the Niemela Patent and the hair clipper of the described embodiment both employ armatures with a minimum mass and their arrnatures reverse direction with a minimum amount of noticeable housing vibration. This is also particularly important since acceptance of vibratory motor hair clippers has been limited in the past because of the presence of excessive vibration of the clipper housing. In addition, vibratory magnetic clippers were unpopular prior to the introduction of the clipper of the Niemela Patent because they were sensitive to the fluctuation in the supply voltage or to change in the load. The vibratory mo-' tors of the Niemela Patent and of the disclosed embodiment of the present invention herein are not inherently load sensitive as are the prior devices.

Despite the successful and highly satisfactory construction of the hair clipper of the Niemela Patent, it has been found that several problems still existed with respect to the design of the hair clipper of that patent. In the hair clipper of the Niemela Patent, the armature was pivoted for oscillating movement about a bearing pin which was secured to the lower housing of the clipper. On each side of the armature, a coil spring was compressed between the lower housing member and the nylon magnet supporting carrier of the armature. The housing had to be constructed so that a pair of U- shaped recesses or spring recesses were formed in it to receive the outer ends of the springs. The other ends of the springs were received by locating bosses on the nylon carrier. In order to dampen vibration noises associated with these springs, they were filled with a foam plastic material. This construction required that the housing be much wider than is optimum for the hand of the average user. The width of the housing made the clipper too bulky to be used comfortably by a user with an average or a small hand over a relatively long period of time.

The elongated hair clipper of the present invention by constrast is extremely narrow and thin and it is, therefore, very easily gripped by even the user with very small hands. The major reasons for this improved shape being that torsion springs are employed in the hair clipper of the present invention which are coiled around the vertical axis of the bearing pin and the use of a new and improved very flat on/off switch. Thus, the elongated hair clipper can be made narrower without increasing its vertical dimension. In addition, with the use of torsion springs, much heavier springs can be employed, and thus, the problem of occasional spring breakage which occurred with the smaller coil springs of the clipper of the Niemela Patent is eliminated.

The torsion springs also serve to hold the armature in place on the bearing pin. Because of this, a separate metal field locating and support member is not required in the hair clipper of the described embodiment as it is in the hair clipper of the Niemela Patent. In the clipper of the present invention, the field is located by plastic abutments which are integrally formed on the housing and by a resilient bushing which is compressed when the upper and lower housing members are secured together. The bushing forces mating cut-out surfaces on the field structure forward thereby forcing abutting members on the field structure against the locating abutments on the housing.

In the hair clipper of the Niemela Patent, blade drive was achieved by means of an extension of the armature which drove the upper blade or the cutter by contact of the armature extension and the cutter along a line. the necessary pressure was maintained by an elongated biasing spring that was screwed into the lower housing of the cutter of the clipper. The biasing spring had a plastic block on its outer end which was inserted into a groove in the cutter so as to force the cutter against the comb.

The drive mechanism described in the previous paragraph has a number of disadvantages. First of all, since the armature extension makes contact with the cutter along a line, excessive wear of the cutter and of the armature may occur. In addition, the biasing spring may be subjected to bending or twisting with respect to the armature which could result in improper or uneven pressure upon the cutter, which in turn would result in impair cutting efficiency and increased load on the armature.

It is, therefore, an object of the present invention to provide a hair clipper having a drive shoe, preferably fonned of plastic, that is easily removable from the upper blade of the clipper when replacement of the blade is desired.

It is another object of the present invention to provide a blade drive mechanism for a motorized device drive pin which is secured to the armature and a drive bearing and a bias spring which are inserted over the drive pin wherein the spring acts on the drive bearing so that the outer end of the drive bearing forces the blades of the clipper together through an intermediate drive assembly.

It is an additional object of the present invention to provide a hair clipper having a guide surface on a drive shoe which is secured to the upper cutter blade of the clipper so that it mates with a corresponding guide surface on the housing.

It is a further object of the present invention to provide a dirve mechanism with a drive bearing having a spherically shaped drive member and a correspondingly shaped recess in a drive socket, wherein the drive socket is preferably provided with a hole that prevents air compression in the recess.

It is another object of the invention to provide a motorized hair clipper of the vibratory armature type having reduced dimensions which are achieved in part by use of torsion bias return springs which are coiled around the vertical axis of the bearing pin which supports the armature.

It is a still further object of the present invention to provide a hair clipper having a two-piece housing with field locating provisions including a compressible bushing which expands when the housing is secured together so as to force the rear end of the field forward so that abutment members on the housing of the clipper and abutment members on the field structure engage each other and thereby locate the field properly.

Additional advantages and objects of the present invention will be apparent to those skilled in the art from this document.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the hair clipper of the present invention with the upper blade or cutter removed;

FIG. 2 is a cross-sectional view of the hair clipper taken along the line 22 of FIG. 1;

FIG. 3 is a plan view looking into the upper housing of the hair clipper with the lower housing removed, but with portions of the lower housing shown in section and with other parts of the clipper in place;

FIG. 4 is a side view of the hair clipper motor armature with the torsion return bias spring in placev on the armature;

FIG. 5 is a side view of the motor field structure and its associated electrical contacts;

, FIG. 6 is a cross-sectional view of the field structure taken along the lines 66 of FIG. 5',

FIG. 7 is a cross-sectional view of the field structure taken along the lines 77 of FIG. 6;

FIG. -8 is a side and partial cross-sectional view of the bobbin of the field structure;

FIG. 9 is a side view of the armature of the clipper motor; I

FIG. 10 is a top view of the armature of the clipper motor; and

FIG. 11 is a front view of the motor field structure which shows the salient magnetic poles of the field.

TECHNICAL DESCRIPTION OF THE INVENTION With reference to the drawings, there is shown in FIG. 1 a hair clipper designated generally by reference numeral 20. The hair clipper includes a housing 22 which is made of an upper housing member 24 and a lower housing member 26. The upper and lower housing members are secured together in abutting relationship by screws 28, 30 to form a motor enclosure 32, as shown in FIG. 2. The housing 22 is preferably formed of a plastic such as phenolic.

A removable blade set 34 is received on the front end of the clipper. The blade set 34 consists of a lower blade or comb 36 and an upper blade or cutter 38 which is pressed into shearing engagement with the comb 36, by a blade drive assembly 40. The comb 36 is secured to the lower housing member 26 by a screw 42 which passes through an opening 44 in the lower portion of the comb 36 and then into a threaded channel 46. There is a small amount of clearance between the screw 42 and the size of the opening 44 so that adjustment of the comb 36 may be easily made in order to achieve proper alignment of the comb 36 and the cutter 38. The comb 36 and the cutter 38 are provided with teeth which have abutting outer edges in the conventional manner so that relative movement between the cutter 38 and the comb 36 will result in the desired cutting action of the hair.

The cutter 38 is provided with a plastic snap-fit" drive shoe 48 which is part of the blade drive assembly 40. The drive shoe 48 has projecting ears 50 that are constructed to extend through slots 38a in the cutter when the ears 50 are pressed toward each other. When the pressure is released on the ears 50, they are forced apart by the natural resiliency of the plastic against the outer edges of the slot 380 so as to lock the drive shoe 48 into the cutter 38. The drive shoe 48, which is best shown in FIG. 3 where the cutter has been removed, is provided with the snap-fit ears 50 so that the cutter 38 may be removed and replaced by a new blade when it is dull. The cutter 38 is made of metal and is relatively thin and lightweight, and with the ease of assembly that is provided by the present invention, it becomes more economical and convenient to replace the cutter 38 when it is dull rather than to resharpen it.

The rear end of the drive shoe 48, which faces towards the motorenclosure 32 is formed in the shape of a trapezoidal channel 52. The trapezoidal channel 52 is open at its bottom and has a top surface 59 and side surfaces 58, 60. Force supplied to the drive shoe 48 through the side surfaces 58, 60 of channel 52 presses the cutter 38 and the comb 36 together and drives a guide surface 54 at the front end of the drive shoe 48 against a downwardly depending mating guide surface 56 on the upper housing member 24. The guide surface 56 is substantially at a right angle with respect tovthe elongated planar surface 38b of the cutter 38. At this angle, the optimum normal force between the cutter 38 and the comb 36 and the optimum normal force between the guide surfaces 54, 56 are obtained. The manner inwhich the required driving force is transmitted to the side surfaces 58, 60 of the drive shoe 48 by the remaining elements of the drive assembly 40 is described later herein. The required mechanical power for the hair clipper is provided by the electrical motor 62 which includes a field or stator 64 and an oscillating armature 66. The armature 66 is supported for oscillating movement by means of a steel bearing pin 68 which has an upper end 68a of reduced diameter that is molded into the housing member 24. An oil impregnated bushing 70 is integrally formed with the armature 66 so as to reduce the friction between the armature 66 and the bearing pin 68. The rear portion of the armature 66 consists of a rigid insulating frame or carrier 72, which is preferably constructed of nylon and into which permanent magnets 74, 76 are integrally molded.

A permanent magnet 78, which is preferably formed of a ferrite ceramic material, is positioned in the carrier 72 between the pole pieces 74, 76.The pole pieces 74, 76 are elongated members that are formed of a suitable, magnetically permeable material,.which may be sintered iron. The pole pieces 74, 76 have at their outer ends a pair of salient pole faces 74a, 74b and 76a, 76b, respectively. The permanent magnet78 is polarized so that the pole pieces 74, 76 are magnetized to the opposite polarities. As a consequence, the salient pole faces 74a, 74b of the pole 74 will be magnetized to the opposite polarity of the salient pole faces 74a, 76b of the pole 76. Thus, when the pole faces 74a, 74b are of a North pole, the pole faces 74a, 76b will be of a South pole; and when the pole faces 74a, 74b are of a South pole, the pole faces 76a, 76b will be of a North pole.

The front end of the carrier 72 of the armature 66 has a steel drive pin 80 which has a rear portion of a reduced diameter 80a that is integrally molded into the forward section of the armature 66. The drive pin 80 passes through a rectangular boss 67 on the forward section of the armature 66. A foam pad 69, which is preferably formed of polyether, surrounds the boss 67 to prevent hair clippings from entering the motor enclosure 32. A drive bearing 84 which is preferably formed of plastic and which has a hollow cylindrical bearing surface 84a that receives the drive pin 80 and ball socket section 84b transmits driving force to dirve socket 86. A coil spring 82 surrounds the hollow cylindrical bearing section 840 and it is compressed around this section between the surface 67a of the boss 67 and the surface 840 of the drive bearing 84. The ball section 84b of the drive bearing 84 transmits the forwardly directed force of the compressed spring 82 to the plastic drive socket 86, having concave spherical recess 86a which receives the ball section 84b in mating relationship.

The plastic drive socket 86 has a front surface 92 and a pair of side surfaces 88, 90 which form a trapezoid that mates with the trapezoidal channel 52 that is formed in the drive shoe 48. The side surfaces 88, 90 of the drive socket 86 abut against the side surfaces 58, 60 of the drive shoe 48 so as to impart a substantially uniform force to the drive shoe 48 along a relatively large surface area. By imparting the drive force along a relatively wide surface area a minimum of wear is insured. In order to prevent the binding of thee socket 86 and the drive shoe 48, space is provided between the forward surface 92 of the drive socket 86 and the rear surface 59 of the trapezoidal channel 52 of the drive shoe 48. Although the drive shoe 48 itself could be formed with the corresponding spherical recess for receiving the ball section 84b, it is preferred that a separate drive member, such as the drive socket 86, be provided so that tolerances in the construction of the blade drive assembly may be increased. The drive socket 86 has a hole 86 c in the spherical recesses 86c which prevents compression of air between the ball 84b and the recess 86c which would reduce the effectiveness of the blade drive mechanism.

In operation, the armature 66 is biased to a central position by means of a pair of torsion springs 94, 96 which surround a downwardly-depending boss 98 that is formed on the upper housing 24 and the downwardly-depending portion 70b of the bushing 70. The carrier section 72 of the armature 66 has a pair of apertures therein, 100, 102 for receiving the bent outer ends 104, 105, respectively, of the torsion springs 94, 96. Slightly sloped spring channels 106, 107 are formed around the upper portion 70a and on the uppermost part of the lower portion 70b of the bearing 70. Sloped spring support bearings 75, 77 are also formed in the upper and lower housing members 24, 26 as shown in FIG. 2. The torsion springs 94, 96 are placed in the spring channels 106, 107, respectively, and are coiled around the vertical axis of the drive pin 80. A pair of cut-away landings 109, 111 are provided at the outer edge of the spring channels 106, 107, respectively, below the level of the upper and lower exterior surfaces 113 and 115 of the carrier 72. The ends 117, 119 of the torsion springs 94, 96 which are not inserted into the apertures 100, 102 are then placed in the landings 109, 111 so that they extend outwardly until they abut against the respective one of the shoulders 121, 123 which are formed integrally with the lower housing member 26. Thus, the springs 94, 96 are able to return the armature 66 to its center position by means of the torsion spring effect that is exhibited by the springs 94, 96 due to the force that is applied between the outer ends 117, 119 of the springs 94, 96 and the corresponding shoulder portions 121, 123 of the housing 22.

By employing torsion springs that are wound about the vertical axis of the bearing pin 68 instead of horizontally oriented coiled springs, such as those employed in the clipper of the previously mentioned Niemela Patent, a very slim and compact hair clipper may be constructed. In addition, by using torsion springs much larger springs can be used and, therefore, the possibility of spring breakage is reduced. The torsion springs 94, 96 are preferably formed of tin plated music wire or the like.

The field 64 for the hair clipper consists of core 114 which is formed of a stack of E-shaped laminations 118 that are made of magnetically permeable material which are retained together and are secured to a plastic supporting bobbinll6 by means of rivets 123. The E- shaped core 114 has a pair of outer legs 120, 122, and a central leg 124. The central leg 124 is substantially thicker than the outer legs 120, 122 and it terminates in a pair of salient poles 124a, and 124b. The outer legs 120, 122 of the core 114 terminate in a salient pole pairs 120a, 122a, respectively. Surrounding the central leg 124 of the core 114 is a field coil 126 which is best shown in FIG. 5. The bobbin 116 has a hollow cylindrical center around which the windings of the coil 126 are wound the windings are of magnetic wire having a conventional suitable insulation thereon. The inside surfaces of the outer legs 120, 122 are further insulated from the coil by a pair of fibre insulators 126, 127 which are inserted between the legs 120, 122 and the outside of the coil 126 (FIG. 3).

When the coil 126 is energized by electrical current flowing in either direction, it will induce magnetic flux in the core 114 which will cause the salient pole faces 124a, 124b of the central leg 124 to be magnetized to one polarity, while the salient pole faces 120a, 122a of the outer legs 120, 122, respectively, will be magnetized to the opposite polarity. By means of the interaction that occurs between the salient poles 120a, 122a, 124a and l24b of the core 114 and the salient poles 74a, 74b, 76a and 76b of the armature 66, the desired vibratory action of the motor is obtained. A more complete description of the operation of a motor that is employed in the present invention may be obtained by reference to the aforementioned Niemela Patent. However, it should be appreciated that the present invention is not limited to the specific type of motor shown in the Niemela Patent.

The bobbin 116 on which the coil 126 is wound is formed with a pair of end panels 130, 132 which extend on opposite sides of the central section 128 so as to form a reel for the coil 126. In addition, however, both the front end panel 130 and the rear panel 132 are provided with a pair of grooves which are used to receive a pair of electrical contact members so as to provide the required electrical connection to the field coil 126 and to the power source. For example, the slots 134, 136 are provided in the front end panel 130 for receiving the electrically conductive connectors 138, 140, respectively. The connectors 138, 140 extend downwardly into the slots 134, 136 along substantially the entire length of the rear end panel 130 and down beyond a forwardly extending ledge 142 of the front end panel 130. The lower ends of the connectors 138, 140 are then outwardly bent and end in terminals 138a, 140a. The forward end of the field coil 126 is brought out and connected to the terminal 140a while the jumper wire 144, which is coupled to the power source, is connected to the terminal 138a.

A pair of slots 146, 148 are also formed in the rear end panel 132 of the bobbin 116 for receiving the connectors 150, 152. The connectors 150, 152 extend downwardly along the rear end panel 130 for a major portion of its length. The lower end of the connectors 150, 152 are bent outwardly and they end in terminals 150a, 152a (FIG. 3). The rear end of the field coil 126 is brought out and is connected to the terminal 150a, and the jumper wire 144, which is also connected to the terminal 138a, is connected to terminal 152a. The terminals 150a, 152a are interconnected with the power cord 154 through a pair of removable female connectors 156, 158 which receive the male terminals 150a,

152a, respectively.

Input power is supplied to the motor 62 the hair clipper through the power cord 154 which passes into the clipper through an aperture 156 in the rear face 158 of the housing 22. A flexible strain relief bushing 160 is secured around the power cord 154 at its end where it passes through the aperture 156. The strain relief bushing 160 has a forward rectangular section 160a and a ring-like section 16% which is separated from section 160a sufficiently to form an intermediate groove 1600 that mates with a corresponding pair of ribs (not shown) formed on the upper and lower housing members 24, 26. This groove and rib thereby holds the bushing 160 in place in the housing 22.

In order that the clipper may be hung on a nail or hook when it is not in use, ,a bail 162, which is preferably formed out of stainless steel, is also provided at the rear face of the clipper 20. The bail 162 is bent so as to act as a spring and the outer ends 162a, 162b of the bail 162 are bent upwardly so as to extend into the holes 164, 165 in the upper housing member 124, thereby securing the bail 162 to the housing 22.

One desirable feature of the hair clipper of the described embodiment is that the field 64 is held in place in the housing of the clipper without the necessity of coupling any external securing means to the field 64. Screws 28, are screwed into the threaded boss 166 at the rear of the upper housing 24 and into the threaded lower end 68a of the bearing pin 68, respectively, to hold the upper and lower housing members 24, 26 together. The lower housing member 26 has an upwardly-projecting cylindrical boss 168 through which the screw 28 also projects. The ledge 154 of the bobbin 116 is formed with two legs 154a, 154b, while the forward portion of the ledge 154 and the core 114 both have a semicircular cutout section 155 so that the legs 154a, 154b of the ledge 154 extend around the lower boss 168. A resilient, compressible cylindrical bushing 170 which is made of neoprene, or other suitable material, is positioned between the bosses 166, 168 and positioned so that the semicircular cutout portion of the edge 114a of the core 114 conforms to the cylindrical outer surface of the bushing 170, as best shown in FIG. 2. The insulating member is compressed between the bosses I66 and 168 when the screws 28, 30 are screwed into their respective bosses and as the bushing 170 is compressed, it presses forward against the edge 114a of the core 114 to urge the field 64 forward. As the field 64 is pressed forward by the compressed bushing 170, the'abutments 184, 186 on the outer legs 120, 122 of the laminations of the core 114 are pressed into contact with abutments 188, that are integrally formed on the upper housing member 24. When the abutments 184, 186 of the field 64 are pressed into contact with the abutments 188, 190, respectively, of the housing 22 and the rear edge 1 14a of the core 114 is wedged against the compressed bushing 170, the field 64 is secured finnly in place in the housing.

A pair of resilient foam pad strips 172, 174 are cemented to the bottom of the core 114. The foam pad strips 172, 174 are compressed against the integrally formed runners 176 of the lower housing member 26 when the housing is secured together. These strips 172,

' 174 are also bent up as the upwardly forward portion of the core 114 so as to abut against the upwardly projecting abutment members 180, 182 of the lower housing member 26. The foam strips 172, 174 are then flattened out when the housing is assembled to take up any looseness that might otherwise exist between the field 64 and the housing 22 to cushion movement of the field 64.

The desired construction for positioning the field in its proper place eliminates, the need for special mounting frames and also the necessity of putting holes in the core structure. In the motor of the described embodiment, the core laminations 1 14 are preferably very thin in order to minimize core losses, and if holes were drilled in thelaminations and mounting screws were inserted in these holes the magnetic properties of the core would be substantially deteriorated.

While there has been illustrated and described a particular embodiment of the present invention, it will be understood that changes and modifications may occur to those skilled in the art, and it is, therefore, contemplated by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed is:

1. A hair clipper comprising a two-piece elongated housing, a blade set comprising a first member and a second member, means to secure said second member to said housing, an electrical motor in said housing, blade drive means for driving said first member relative to said second member comprising force transmitting means coupled to said motor constructed to transmit a biasing force along the elongated dimension of said housing, a drive shoe positioned in abutting engagement with said drive means and secured to said first member so as to press said first and second members together in response to said biasing force, said drive shoe having a first guide surface formed thereon, said housing having a second guide surface formed thereon, said first and second guide surfaces being biased into engagement during operation of said device to maintain said first and second members in aligned cutting relationship.

2. A drive shoe and cutter blade construction for a hair clipper having a comb blade comprising a metal cutter blade having cutting teeth and openings therein and a drive shoe formed of a resilient material having segments which are removably secured in respective ones of said openings in said blade by the natural resiliency of said material, said drive shoe further having a plurality of driving surfaces located remote from said resilient segments for receiving driving and biasing forces thereon for driving said cutter blade and for biasing said cutter blade against said comb blade.

3. The drive shoe and cutter blade combination of claim 2 wherein the blade has two elongated slot openings therein and the drive shoe has two spread apart elongated segments which can be moved toward each other by a squeezing force so as to pass through the elongated slot openings of the blade and said segments are secured in said slot openings of said blade when the squeezing force on said segments is released.

4. A hair clipper comprising an elongated housing, an electric motor in said housing having a stationary field means and a vibrating armature, a blade set comprising a first member and a second member, means to secure said second member to said housing, said armature being located in said housing intermediate said field means and said blade set, a drive pin secured to said armature and projecting along the elongated dimension of said housing toward said blade set, a drive bearing having a hollow bearing section which is positioned over said drive pin and a spherical end section on the outer end of said drive bearing, resilient compressible spring means surrounding said bearing section and biasing said spherical end section toward said blade set, blade drive and biasing means comprising a spherical recess for receiving said spherical end section, said blade drive and biasing means being in engagement with said first member of said blade set so as to bias said first and second members together and so as to drive said first member in vibratory motion relative to said second member and said spherical recess having a hole therein to prevent air compression in said recess.

5. A hair clipper comprising an elongated housing, an electric motor in said housing having a stationary field means and a vibrating armature, a blade set comprising a first member and a second member, means to secure said second member to said housing, said armature being located in said housing intermediate said field means and said blade set, a drive pin secured to said armature and projecting along the elongated dimension of said housing toward said blade set, a drive bearing having a hollow bearing section which is positioned over said drive pin and a spherical end section on the Y outer end of said drive bearing, resilient compressible spring means surrounding said bearing section and biasing said spherical end section toward said blade set, blade drive and biasing means comprising a spherical recess for receiving said shperical end section, said blade drive and biasing means being in engagement with said first member of said blade set so as to bias said first and second members together and so as to drive said first member in vibratory motion relative to said second member, said blade drive and biasing means comprising a drive socket having said recess therein and a separate drive shoe which is secured to said first member, said drive socket having one or more first surfaces, and said drive shoe having one or more second surfaces which are in engagement with respective ones of said first surfaces so as to transmit the forces applied to said recess by said spherical end section from said 7. A hair clipper as set forth in claim 5 wherein said spherical recess has a hole therein to prevent air compression in said recess.

8. A hair clipper as set forth in claim 5 wherein said drive shoe has a first guide surface that extends from the first member of said blade set in substantially a normal direction, said housing has a second guide surface substantially parallel to said first guide surface and said first and second guide surfaces are in engagement during operation of the clipper.

9. A hair clipper as set forth in claim 5 wherein the said drive socket has a first generally trapezoidal crosssection with said first surfaces forming the sides of said first cross-section and said drive shoe is formed with a channel having a second generally trapezoidal crosssection with said second surfaces forming the sides of said second cross-section.

10. A hair clipper as set forth in claim 5 wherein said drive shoe has a first guide surface that extends from the first member of the blade set in substantially a normal direction, said housing has a second guide surface substantially parallel to said first guide surface and said first and second guide surfaces are in engagement during operation of the clipper.

l 1. A motorized device comprising a two-piece housing having a first housing member and a second housing member, an electric motor in said housing having a stationary field means and a vibratory armature, said first housing having a first boss and said second housing having a second boss spaced apart from said first boss, a compressible, expandable bushing positioned intermediate said first and second bosses, means to secure said first and second housing members together and to compress said expandable bushing between said first and second bosses thereby expanding the dimensions of said bushing in at least one direction, said field means having a surface at a first end thereof which is in contact with an outer surface of said expandable means when said expandable means is expanded by compression, first abutment means on said field means located near a second end of said field means, second abutment means on said housing located adjacent said second end of said field means with said field means being movable in said housing in response to the force exhibited on said first end of said field means by said expandable means so as to move said first abutment means into engagement with said second abutment means thereby locating said field means properly in said housmg.

12. A motorized device as set forth in claim 11 wherein a pair of runners are provided on opposite sides of said housing so that said field means is slideable back and forth on said runners and a pair of resilient pads are positioned intermediate said field means and said runners.

13. A motorized device as set forth in claim 12 wherein said resilient pads extend over a portion of said first end of said field means and said housing has third abutment means located such that said resilient pads are positioned intermediate said third abutment means and said first end of said field means.

14. A hair clipper comprising a two-piece housing having a first housing member and a second housing member, an electric motor in said housing, having a stationary field means and a vibratory armature, said first housing having a first boss and said second housing having a second boss spaced apart from said first boss, a compressible, expandable means positioned intermediate said first and second bosses, means to secure said first and second housing members together and to compress said expandable means between said first and second bosses thereby expanding the dimensions of said expandable means in at least one direction, said field means having a surface at a first end thereof which is in contact with an outer surface of said expandable means when said expandable means is expanded by compression, first abutment means on said field means located near a second end of said field means, second abutment means on said housing located adjacent said second end of said field means with said field means being movable in said housing in response to the force exhibited on said first end of said field means by said expandable means so as to move said first abutment means into engagement with said second abutment means so as to locate said field properly in said housing.

15. A hair clipper as set forth in claim 14 wherein a pair of runners are provided on opposite sides of said housing so that said field means is slideable back and forth on said'runners and a pair of resilient pads are positioned intermediate said field means and said runners.

16. A hair clipper as set forth in claim 15 wherein said resilient pads extend over a portion of said first end of said field means andsaid housing has third abutment means located such that said resilient pads are positioned intermediate said third abutment means and said first end of said field means.

17. A hand-held hair clipper comprising a thin, elongated two-piece housing with a rear end and a front end and having a first housing member and a second housing member, an electric motor in said housing having a stationary field means having a rear end and a front end and a vibratory armature positioned adjacent said front end of said field means, said first housing having a first boss near said rear end, said second housing means having a first surface at the rear end thereof which is in contact with an outer second surface of said expandable means when said expandable means is expanded by compression, first abutment means located ment means on said housing located adjacent said front end of said field means with said field means being movable toward the front end of said housing in response to the force exhibited on said first surface at said rear end of said field means via said second surface of said expandable means so as to move said first abutment means into engagement within said second abut ment means thereby locating said field properly in said housing, a bearing pin around which said armature oscillates, a pair of torsion springs located on opposite sides of said armature for returning said armature to a central position, said bearing pin being secured to said housing and projecting along the thin dimension of said housing, said torsion springs being coiled around the axis of said bearing pin, one end of each of said torsion springs being secured to said armature and the other end of each of said torsion springs being in engagement with said housing, a blade set comprising a first blade member and a second blade member, said armature being located in said housing intermediate said field means and said blade set, means to secure said second blade member to said front end of said housing, a drive pin secured to said armature and projecting along the elongated dimension of said housing toward said blade set, a drive bearing having a hollow bearing section which is positioned over said drive pin and aspherical end section on the outer end of said drive bearing resilient, compressible spring means surrounding said bearing section and biasing said spherical end section toward said blade set, blade drive and biasing comprising a spherical recess for recieving said spherical end section, said blade drive and biasing means being in engagement with said first blade member so as to bias said first and second members together and so as to drive said first blade member in vibratory motion relative to said second blade member.

18. A hair clipper as set forth in claim 17 wherein said blade drive and biasing means comprises a drive socket having said recess the rein and a separate drive shoe which is secured to said first member, said drive socket having one or more first surfaces, and said drive shoe having one or more second surfaces which are in engagement with respective ones of said first surfaces so as to transmit the forces applied to said recess by said spherical end section from said drive socket to said first member of said blade set via said drive shoe.

19. A hair clipper as set forth in claim 18 wherein said drive shoe is removably secured to said first blade compression in said recess.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4651761 *Nov 6, 1985Mar 24, 1987Suen Ru HHair cutting tool
US6243955Apr 16, 1999Jun 12, 2001Anthony Glen ForbersHair clipper attachment device and method of use
US7239053 *May 8, 2003Jul 3, 2007Wahl Clipper CorporationVibrator motor
US8610329 *Dec 12, 2008Dec 17, 2013Wahl GmbhDrive unit for a hair cutting machine
US20100307009 *Dec 12, 2008Dec 9, 2010Heinrich SchwerDrive unit for a hair cutting machine
Classifications
U.S. Classification310/29, 30/210
International ClassificationB26B19/28, H02K33/04
Cooperative ClassificationH02K33/04, B26B19/282
European ClassificationB26B19/28A, H02K33/04