Abstract:
A hair depilating device having a plucking assembly comprising at least two hubs, each accomodating at least one radially-extending swivel element mounted on the hub via a pin radially extending from the wall of the hub. The sidewall of the hub further includes a pinch plate, which projects radially outwardly therefrom. The radially-extending swivel element and pinch plate of a neighboring disc-like assembly define a V-shaped hair trap. The other side of the pinch plate forms a second V-shaped hair trap with a radial extension swivel element of a third opposing neighboring disc-like assembly. The opposing edges of the hair-traps at the rear end meet first, and only afterwards is the entire trap closed. This design provides a substantially reduced rotational closure distance, traveled by the hair-trap elements from the instant the trap begins to close until full trap closure. The trap closing displacement required for closure is also greatly reduced and more hairs are trapped and the plucking efficiency increased.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a hand held, motorized depilating device for removing unwanted skin hair, and more particularly, for plucking out skin hair, utilizing a new method to shorten hair-trap closure distance, thereby increasing the hair plucking efficiency. 
     BACKGROUND OF THE INVENTION 
     Substantially all the depilating devices currently on the market operate in a very similar manner. Their operation is based on a rotating hair plucking assembly having a collection of tweezer elements mounted thereon. Hair traps, formed by the interaction between the aforementioned tweezer elements, are opened and closed by either employing a system of cams or by employing inclined thrust bearings. The first of these types is shown in the devices based on U.S. Pat. No. 5,112,341 to Dolev, the present inventor. The second of these types is shown in the devices based on U.S. Pat. No. 5,281,233 to Dolev. Another common feature is that in these depilating devices, opposing edges of the hair-trap tweezer elements remain parallel to one another, during the entire period of hair-trap opening and closing. 
     Opening and closing the aforementioned hair traps by employing a system of inclined thrust bearings is quiet, efficient and essentially devoid of excess vibrations. However, the rotational closure distance, traveled by the hair-trap elements from the instant the trap begins to close until full trap closure, is quite long. Consequently, a large percentage of the hairs that entered the trap at an early stage of closure succeed in escaping the trap before closure is complete. In addition, another substantial percentage of hairs is unable to enter the trap during the later stages of closure, as the entry gap to the trap has been substantially reduced at these stages. 
     It is possible to reduce the rotational closure distance, traveled by the hair-trap elements from the instant the trap begins to close until full trap closure, by employing cams to convey the closing force. However, use of the cam mechanism increases the energy expenditure, the noise level, the vibrations, and the resulting level of discomfort encountered in using the device. 
     Therefore, it would be desirable to provide a superior power-driven depilating device, which provides a reduction in the rotational closure distance, traveled by the hair-trap elements from the instant the trap begins to close until full trap closure. In addition, it would be desirable to simultaneously increase the hair plucking efficiency, without increasing the energy expenditure, the noise level, the vibrations, and the resulting level of discomfort encountered in using the device. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a principal object of the present invention to overcome the above-mentioned disadvantages and provide a hand-held, motorized depilating device for removing unwanted skin hair, introducing a new method to shorten the closure distance of the hair-traps without increasing the energy expenditure, the noise level, the vibrations, and the resulting level of discomfort encountered in using the device. 
     In accordance with a preferred embodiment of the present invention, there is provided a motor-powered depilating device comprising: 
     a hair-plucking assembly, coupled to motor means, and being exposed through an opening in a manually-held housing, said hair-plucking assembly being rotatable about a shaft and including at least two disc-like assemblies, each disc-like assembly comprising: 
     a central hub; 
     at least one radially-extending swivel support formed thereon; 
     at least one radially-extending swivel element mounted in spring-biased fashion on a pin radially extending from said hub, through said radially-extending swivel support, thereby defining a swiveling axis, an outer end of said swivel element defining a flattened peripheral portion substantially perpendicular to said swiveling axis, said flattened peripheral portion forming a first hair trap edge, and 
     a pinch plate extending radially outwardly from said hub, circumferentially offset from said flattened peripheral portion and being disposed opposite a flattened peripheral portion defining a first hair trap edge associated with an adjacent disc-like assembly, 
     said pinch plate providing a second hair trap edge, which together with said associated first hair trap edge, defines a V-shaped hair trap, 
     and 
     a motion control means arranged to provide closing and opening motion of said V-shaped hair trap by forcing said associated first hair trap edge against said second hair trap edge during rotational motion of said disc-like assemblies about said shaft. 
     In the preferred embodiment, the hair plucking assembly comprises at least two hubs, each accommodating at least one radially-extending swivel support. At least one radially-extending swivel element is mounted in spring-biased fashion on a pin radially extending from a hub. The sidewall of the hub further includes a pinch plate, which projects radially outwardly therefrom. A radially extending swivel element associated with a disc-like assembly is spring-biased to a certain position and arranged so as to define a V-shaped hair trap, with a pinch plate associated with an adjacent disc-like assembly. The other side of said pinch plate forms a second V-shaped hair trap with a radially-extending swivel element of another opposing neighboring disc-like assembly. 
     in the inventive device, the opposing edges of the hair-trap elements do not remain parallel to one another, during the entire period of hair-trap opening and closing. With respect to the direction of rotation of the disc-like assembly, opposing edges at the rear end are closed first, leaving the hair-trap entrance open, and only afterwards is the entire trap closed. 
     The inventive device provides three outstanding advantages: 
     1. The rotational closure distance, traveled by the hair-trap elements from the instant the trap begins to close until full trap closure, is substantially less than the rotational closure distance traveled when utilizing parallel-positioned opposing edges of hair-trap tweezer elements. 
     2. Since opposing edges at the rear end meet first, that end of the trap is essentially closed. This effectively delays the escape of hairs that have already entered the trap. The trap closing displacement required for closure is shortened and more hairs are trapped and the plucking efficiency increased. 
     3. The shortened trap closing displacement reduces the noise and vibration level associated with the device operation, and consequently, yields a reduced level of energy expenditure. 
     To activate the traps in the manner described above, requires that opposing radially extending swivel elements swivel on an axis substantially perpendicular to peripheral portion alignment. In addition, the opposing edges must approach the state of closure with one set of ends biased adjacent to the trap face, i.e. the line of trap closure. This is accomplished by utilizing a biasing spring or other biasing arrangement, as will be described further herein. 
     According to the preferred embodiment, in accordance with the principles of the present invention, the hubs are rotatably mounted on a fixed arcuate shaft and each hub includes engagement means for engaging at least one adjacent hub so that rotational motion of one hub imparts rotational motion to an adjacent hub. Trap opening and closing is accomplished by using a motion control means employing inclined pressure bearings. 
     According to another embodiment, the hubs are rotatably mounted on a straight shaft, and trap opening and closing is accomplished by using a motion control means employing cams or inclined thrust bearings. 
    
    
     Other features and advantages of the invention will become apparent from the drawings and the description contained herein below. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the invention, reference is made to the accompanying drawings, in which like numbers designate corresponding elements or sections throughout, and in which: 
     FIG. 1 is a side cross-sectional view of a prior art depilating device as shown and described in U.S. Pat. No. 5,281,233 to Dolev, featuring a number of disc assemblies; 
     FIG. 2 is a plan view of a disc assembly used in the device of FIG. 1; 
     FIG. 3 is a perspective view of the disc assembly of FIG. 2; 
     FIG. 4 shows the disc assembly of FIG. 2, as rotatably mounted on a fixed arcuate shaft; 
     FIG. 5 displays an edge view of the disc assembly of FIG. 4; 
     FIG. 6 is a perspective view of the disc assembly of FIG. 4, featuring a pinch plate feature, which doubles the number of hair-traps; 
     FIG. 7 displays an edge view of the disc assembly of FIG. 6; 
     FIG. 8 schematically illustrates a prior art depilating device employing inclined thrust bearings, in which the opposing edges of the hair-trap remain parallel to one another, during the entire period of hair-trap opening and closing; 
     FIG. 9 schematically illustrates a preferred embodiment of a depilating device employing inclined thrust bearings, constructed and operated in accordance with the principles of the present invention, in which the opposing edges of the hair-trap are V-shaped, i.e. not parallel to one another, during the entire period of hair-trap opening and closing; 
     FIG. 10 schematically illustrates a prior art depilating device employing cams, in which the opposing edges of the hair-trap remain parallel to one another, during the entire period of hair-trap opening and closing; 
     FIG. 11 schematically illustrates an alternative embodiment of a depilating device of the present invention, employing cams, in which the opposing edges are V-shaped, i.e. not parallel to one another, during the entire period of hair-trap opening and closing; 
     FIG. 12 is an exploded perspective view of the preferred embodiment of a depilating device disc-like assembly of the present invention, featuring radially-extending swivel elements and a biasing spring; 
     FIG. 13 is a sectional view of several adjacent prior art disc assemblies, incorporating the pinch plate feature, as shown in FIGS. 6-7; 
     FIG. 14 is a sectional view of the preferred embodiment of the present invention featuring several adjacent disc-like assemblies, incorporating the pinch plate feature and the swivel elements; 
     FIG. 15 is a perspective view of an alternative embodiment of a depilating device disc-like assembly of the present invention, featuring alternative types of spring-like swivel members; 
     FIG. 16 is a side cross-sectional view of the preferred embodiment of the present invention, featuring a number of disc-like assemblies; 
     FIG. 17 is an isometric view of the preferred embodiment of the present invention, showing the electrical motor and air compressor; 
     FIG. 18 is a cross sectional view of the device of FIG. 17; 
     FIG. 19 is a perspective view of the preferred embodiment of the present invention, featuring a pain reducing attachment, mounted on each radially extending swivel support; 
     FIG. 20 is a perspective view of an alternative embodiment of the present invention, featuring a pain reducing attachment, mounted on each radially extending swivel support, but not incorporating the pinch plate feature; and 
     FIG. 21 is a sectional view of an alternative embodiment of the present invention featuring several adjacent disc-like assemblies, incorporating the swivel elements, but not the pinch plate feature. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-3 are reproduced from U.S. Pat. No. 5,281,233 to Dolev, inventor of the present invention. The figures are thoroughly described therein, with regard to the reference numbers shown. Therefore, the following description relates only to the specific features of interest for which a description is required in order to compare the previous and present inventions. 
     FIG. 1 shows a cross-sectional view of the prior art device, featuring a number of disc assemblies. The hair plucking assembly  12  is shown, comprising one or more disc assemblies  28 . Each of disc assemblies  28  is rotatably mounted on an arcuate shaft  32 . The curved portion of arcuate shaft  32  has a constant radius of curvature, such that disc assemblies  28  are caused with the assistance of inclined thrust bearings  54  and  64  and push rods  56  and  66  to efficiently and smoothly close and open hair-traps. 
     FIG. 2 is a plan view of a disc assembly used in the device of FIG.  1 . Disc assembly  28  is comprised of three major parts: a hub  34 , and a pair of discs  36 . Each of discs  36  has at least one radially extending arm  38 , emanating from its center. Each arm  38  terminates in a flattened peripheral portion  40 . When flattened peripheral portion  40  is pressed against the corresponding flattened peripheral portion  40  of the complementary disc  36  a trap is formed. The central portion of each disc  36  has an opening, which is sized and shaped to fit over a projection of hub  34 . Hub  34  has shoulders  46 , one shoulder  46  per arm  38  of disc  36 . Shoulders  46  are sized and shaped so that the leading edge of each arm  38  abuts against a portion of one of shoulders  46 . A rotational motion of hub  34  transmits the same rotational motion to discs  36 . Hub  34  includes a series of axial engagement protrusions  70  and recessions  72 , for engaging corresponding portions in the adjacent hub, to insure that the disc assemblies interact properly. 
     As seen in FIG. 3, extending from shoulders  46  of hub  34  is a pair of axial protrusions  48 , extending axially in opposite directions. When a particular set of axial protrusions  48  is located in the concave configuration produced by the curvature of arcuate shaft  32 , axial protrusions  48  extend through the open spaces between adjacent arms  38  of discs  36  to touch the nearer disc  36  of an adjoining disc assembly  28 , thereby causing the adjoining disc assembly  28  to form a trap. (see FIG.  1 ). Hub  34  includes an edge  50 , which lies between each pair of corresponding arms  38  of complementary discs  36 . 
     Whenever axial protrusions  48  of adjoining disc assemblies  28  press discs  36  together, a pair of arms  38  of complementary discs  36  pivot slightly towards each other about the corresponding edge  50  of hub  34  located between the pair of arms  38 . This pivoting brings the pair of flattened peripheral portions  40  at the end of the pair of arms  38  together in parallel fashion to form a trap. 
     FIG. 4 shows the disc assembly of FIG. 2, as rotatably mounted on a fixed arcuate shaft. As shown by the directional arrows A in the diagram, the radially extending arms  38  pivot about an axis oriented parallel to the peripheral portions  40  of the hair trap. 
     FIG. 5 displays a sectional view of the disc assembly of FIG.  4 . 
     FIG. 6 is a perspective view of a disc assembly, incorporating the pinch plate feature, as described in the above-referenced Dolev patent (U.S. Pat. No. 5,281,233), at col. 7, lines 27-42. The edge  50  of hub  34  includes a pinch plate  39 , which projects radially outward from edge  50 , and which doubles the number of hair-traps. 
     FIG. 7 displays a sectional view of the apparatus of FIG.  6 . The pivoting or bending of arms  38  of discs  36  towards each other effects the creation of two traps. One trap is formed between one face of the pinch plate  39  and one of flattened peripheral portions  40  and the other trap is formed between the other face of the pinch plate  39  and the flattened peripheral portion  40  of the complementary disc  36 . 
     FIG. 8 schematically illustrates a prior art device, in which the opposing edges of the trap, i.e. flattened peripheral portions  40 , remain parallel to one another, during the entire period of hair-trap opening and closing. Arrow B designates the direction of rotation, and arrows C designate the direction of hair trap displacement. Hair traps are opened and closed by employing inclined thrust bearings  54 . The entrance width between the opposing edges of the trap is given as 1 mm., such that to close the trap, the trap closing displacement required for each side of the hair-trap is 0.5 mm. As can be seen, the rotational closure distance to achieve trap closure is 5.0 mm. 
     FIG. 9 schematically illustrates a preferred embodiment of a depilating device constructed and operated, in accordance with the principles of the present invention, in which the opposing edges of the hair-trap do not remain parallel to one another, during the entire period of hair-trap opening and closing. Hair traps are opened and closed by employing inclined thrust bearings. With respect to the direction of rotation of the disc-like assembly (arrow B), the rear set of ends of opposing edges meet first, and only afterwards is the entire trap closed. Although the entrance width between the opposing edges of the trap remains 1.0 mm, in order to close the trap, the trap closing displacement required for each side of the hair-trap is only 0.25 mm. 
     As can be seen from a comparison of FIGS. 8 and 9, the rotational closure distance has been reduced from 5 mm in the prior art design, to 3.5 mm in the present invention. 
     FIG. 10 schematically illustrates a prior art device, in which the opposing edges of the trap, i.e. flattened peripheral portions  40 , remain parallel to one another, during the entire period of hair-trap opening and closing. Hair traps are opened and closed by employing cams  57  and cam follower  58 . The entrance width between the opposing edges of the trap is given as 1 mm., and the closing displacement required to close the trap is 0.5 mm. for each side of the hair-trap. 
     FIG. 11 schematically illustrates an alternative embodiment of a depilating device of the present invention, in which the opposing edges do not remain parallel to one another, during the entire period of hair-trap opening and closing. Hair traps are opened and closed by employing cams. The rear set of ends of opposing edges meet first and only afterwards is the entire trap closed. Although the entrance width between the opposing edges of the trap remains 1.0 mm, in order to close the trap, the trap closing displacement required for each side of the hair-trap is only 0.25 mm. 
     FIG. 12 is an exploded perspective view of an embodiment of a depilating device disc-like assembly of the present invention, featuring radially-extending swivel elements  38   a . A disc-like assembly  28   a  comprises a central hub  34   a  having formed thereon a set of three radially-extending swivel supports  50   a . In each of swivel element supports  50   a , there is formed at least one cavity  43 . At least one radially extending element  38   a  has formed on its inside surface a pair of lugs  45  through which pin  35  passes. Pin  35  is connected pivotally to radially-extending swivel supports  50   a  via aperture  43   a . An outer end of the radially extending element  38   a  defines a flattened peripheral portion  40   a . Radially-extending swivel element  38   a  is mounted in spring-biased fashion on pin  35 , which defines a swiveling axis. In this embodiment, the spring biasing force (arrow E) is provided by compression spring  33 , which is seated in cavity  43 . Radially extending element  38   a  swivels about pin  35 , as shown by rotational arrows D. 
     As seen in FIG. 12, the sidewall of the hub  34   a  has a pinch plate  39   a  extending radially outwardly therefrom, and circumferentially offset from the flattened peripheral portion  40   a.    
     Hub  34   a  includes a series of axial engagement protrusions  70   a  and recessions  72   a , for engaging corresponding portions in the adjacent hub, to insure that the disc-like assemblies interact properly. 
     FIG. 13 is a sectional view of several adjacent disc assemblies, incorporating the pinch plate feature, as specifically mentioned in U.S. Pat. No. 5,281,233 to Dolev. In this prior art design, each disc assembly is able to form traps by utilizing its own flattened peripheral portion  40  components. Trap closing activation force is transmitted between adjacent discs by axial protrusions  48  as shown in FIGS. 6,  7 . 
     FIG. 14 is a sectional view of several adjacent disc-like assemblies, incorporating the pinch plate feature and the radially extending swivel arms, constructed and operated, in accordance with the principles of the present invention. In the present invention, two disc-like assemblies are required to form a trap between pinch plate  39   a  and a flattened peripheral portion  40   a.    
     FIG. 15 is a perspective view of an alternative embodiment of a depilating device disc-like assembly of the present invention, featuring alternative types of spring-like swivel members  38   b  and  38   c  acting as radially extending swivel elements. Whereas in FIG. 12, it can be clearly seen that the two radially-extending swivel elements share a common swiveling axis, in FIG. 15 each radially-extending swivel element has its own virtual swiveling axis  35   a , that is still substantially perpendicular to the flattened peripheral portions  40   a . The swivel elements and biasing spring employed in FIG. 12 have been replaced by spring-like members  38   b,c . The spring-like swivel members  38   b,c  are fixed to the hub by ultrasonic welding or other method, thus ensuring consistent springiness. 
     FIG. 16 is a side cross-sectional view of an embodiment, constructed and operated in accordance with the principles of the present invention, featuring a number of disc-like assemblies. Pinch plate  39   a  is shown disposed between a pair of flattened peripheral portions  40   a  associated with adjacent disc assemblies, so as to define a pair of V-shaped hair traps, one on each side of the pinch plate. 
     Spring  62  transmits trap-closing force (arrow G) via inclined thrust bearing  54  to the total hair plucking assembly. Arrows F show the flow of air through the depilating device, which is provided to create a positive pressure, as described further herein with respect to FIG.  18 . 
     FIG. 17 is a perspective view of the preferred embodiment of the device, showing a miniature air compressor  80  mechanism, including a shroud  82  and impeller  81 . 
     FIG. 18 is a cross-sectional view of the device of FIG. 17, in which the miniature air compressor  80  is shown. The dotted arrows F indicate the airflow in the device, and this airflow is developed when depilating device motor  14  is activated. This airflow setup creates a positive pressure to prevent small hairs from clogging the sensitive internal mechanisms and pressure bearings. 
     FIG. 19 is a perspective view of the preferred embodiment of the present invention, featuring soft whipping pain reducing attachments, mounted on each radially extending swivel support  50   a . The direction of rotation is designated by arrow B. The pain reducing attachment  37   a  is shown in two positions: before rotation it is retracted (shown as  37 ) and once the rotation starts it is extracted (shown as  37   a ) beyond the periphery of the disc-like assembly by centrifugal force. In this embodiment, pain reducing attachment  37   a  is made of soft plastic and mounted on the top portion of pin  35 , and contacts the skin before the trap edges do. This prior contact desensitizes the skin to an appreciable degree and thereby reduces the pain level experienced. In other embodiments, the pain reducing attachment  37   a  may be mounted in other locations on the periphery of the radially extending swivel support  50   a.    
     FIG. 20 is a perspective view of an alternative embodiment of the present invention, not incorporating the pinch plate feature, featuring a pain reducing attachment, mounted on each radially extending swivel support  50   a . The direction of rotation is designated by arrow B. The pain reducing attachment  37   a  is shown in two positions: before rotation it is retracted (shown as  37 ) and once the rotation starts it is extracted (shown as  37   a ) beyond the periphery of the disc-like assembly by centrifugal force. In this embodiment, pain reducing attachment  37   a  is made of soft plastic and mounted on the top portion of pin  35 , and contacts the skin before the trap edges do. This prior contact desensitizes the skin to an appreciable degree and thereby reduces the pain level experienced. In other embodiments, the pain reducing attachment  37   a  may be mounted in other locations on the periphery of the radially extending swivel support  50   a.    
     FIG. 21 is a sectional view of several adjacent disc-like assemblies, incorporating the radially extending swivel arms, constructed and operated, in accordance with the principles of the present invention. In the present invention, two disc-like assemblies are required to form a trap with pinch plate  39   a . In this embodiment, the pinch plate feature is not incorporated. 
     Having described the invention with regard to a certain specific embodiment, it is to be understood that the description is not meant as a limitation since further modifications may now suggest themselves to those skilled in the art, and it is intended to cover such modifications, as fall within the scope of the appended claims.