Abstract:
A compact, ergonomic, lighted, retractable seam ripper is provided, having a housing, a retractable seam ripping blade, an LED, a battery, and a switch. The housing has generally planar exterior sidewalls and lower peripheral surface, a generally arcuate upper peripheral surface, a blade opening in the upper surface, and a longitudinally extending first and second rail generally parallel to the lower peripheral surface. The retractable seam ripping blade is mounted on a blade holder translatable along the first rail. A spring integral with the holder has a locking projection that engages locking depressions in the second rail. An actuating member between the spring and housing dislodges the locking projection from each of the locking depressions. The switch connects the LED to the battery when actuated.

Description:
CLAIM FOR PRIORITY 
       [0001]    This Non-Provisional patent application is based on U.S. Provisional Patent Application Ser. No. 62/239,110, filed on Oct. 8, 2015, the priority of which is claimed, and the disclosure of which is incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    “To err is human” so it is safe to conjecture that seam rippers, in one form or another, have been around almost since the dawn of sewing. Traditionally, these take the form of a blade having a U-shaped cutting-edge recessed at the base of a larger U-shaped thread guide. In the typical case, the blade is fixed to an elongated rod shaped handle and a mating cover detachably mountable upon the handle covers the blade when not in use. Commonly, the detachable mating cover can also mount upon the rearmost end of the handle in the hope, often vain, that it will not be lost. In some cases, the handle is formed to be grasped in the palm with the blade being guided between the thumb and forefinger. Curiously, a commercially available embodiment of this design uses a curved blade rather than the more commonly encountered U-shaped. In other cases, less commonly, a method for shielding the blade in the handle is provided, either by retracting the blade into the handle or by rotating it into a slot formed in the handle. In still another case, a light is provided in the handle to facilitate accuracy. 
         [0003]    However, what has heretofore been lacking in the retinue of tools available to the tailor or seamstress is a compact ergonomic lighted retractable seam ripper. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is drawn to a lighted retractable seam ripper. The seam ripper comprises a housing, a retractable seam ripping blade, and an LED with a switch and battery. 
         [0005]    The housing has generally opposed exterior sidewalls, a generally planar lower peripheral surface joined to an upper peripheral surface, a longitudinally extending first guide within the housing, and a second longitudinally extending guide. The first guide is generally parallel to the generally planar lower peripheral surface. The second guide has two first locking portions formed therein. A blade opening is formed in the upper peripheral surface near an intersection of the upper peripheral surface and the generally planar lower peripheral surface. An illumination opening is formed in the generally arcuate upper peripheral surface spaced from, but closely adjacent to, the blade opening. The exterior sidewalls of the housing have elastomeric gripper pads located centrally thereupon. 
         [0006]    The seam ripping blade has a tapered lower projection and a blunted upper projection with a U-shaped cutting-edge disposed therebetween. The seam ripping blade is mounted on a blade holder translatable along the first guide. A spring engages the blade holder and the second guide. The spring has a second locking portion biased against the second guide and mateable with either of the first locking portions. When one of the first locking portions is mated with the second locking portion, the seam ripping blade projects from the blade opening. When the second locking portion is mated with the other of the first locking portions, the seam ripping blade is retracted within the housing. An actuating member extends between the spring and the exterior of the housing. The actuating member, when urged inwardly, dislodges the locking portions from engagement. When the member is urged rearwardly or forwardly, the member impels the blade holder to translate along the first guide. 
         [0007]    The LED is disposed adjacent to the illumination opening. A battery contained within the housing and a switch mounted in a wall of the housing operatively connect and disconnect the LED to the battery when actuated. 
         [0008]    Other aspects and advantages of the present invention are described in the detailed description below and in the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention is described in detail below with reference to the appended drawings, wherein like numerals designate similar parts. In the Figures: 
           [0010]      FIG. 1  is an exploded isometric view of the compact ergonomic lighted retractable seam ripper of the present invention. 
           [0011]      FIG. 2  is a sectional view of both halves of the compact ergonomic lighted retractable seam ripper of the present invention with the blade extended as in use. 
           [0012]      FIG. 3  is a sectional view of both halves of the compact ergonomic lighted retractable seam ripper of the present invention with the blade retracted as in storage. 
           [0013]      FIG. 4  is an isometric perspective of the compact ergonomic lighted retractable seam ripper of the present invention with the blade extended. 
           [0014]      FIGS. 5, 6, and 7  illustrate the structure of a locking spring which is particularly advantageous in construction of the compact ergonomic lighted retractable seam ripper of the present invention. 
           [0015]      FIG. 8  is an isometric perspective illustrating a preferred embodiment compact ergonomic lighted retractable seam ripper of the present invention in which the seam ripping blade is lowered relative to the lowest extremity of the housing. 
           [0016]      FIG. 9  is a left elevation of the compact ergonomic lighted retractable seam Ripper of  FIG. 8 . 
           [0017]      FIGS. 10 and 11  are sectional views illustrating the interior workings of the preferred embodiment of  FIGS. 8 and 9  in which the seam ripping blade is lowered. 
           [0018]      FIG. 12  is an exploded isometric of the seam ripper of the present invention in which a normally off switch is used to control the lamp to prevent premature exhaustion of the battery. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    The invention is described in detail below with reference to several embodiments and numerous examples. Such discussion is for purposes of illustration only. Modifications to particular examples within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to one of skill in the art. Terminology used herein is given its ordinary meaning consistent with the exemplary definitions set forth immediately below. 
         [0020]    In  FIGS. 1 and 2 , the compact ergonomic lighted retractable seam ripper  10  is comprised of unitary right-hand housing half  12  and unitary left-hand housing half  212  with unitary right-hand housing half  12  having upstanding peripheral wall  14  having formed therein: right blade retraction recess  16 ; right illumination recess  18 ; right illumination switch recess  20 ; and elongated inwardly displaced right positioning slot  22  with right positioning recess  24  being formed therein. Right upper positioning rail  26  extends rearwardly from a position adjacent right blade retraction recess  16 . Right lower positioning rail  28  is spaced from and generally parallel to right upper positioning rail  26 . Forward blade stop recess  30  and rearward blade stop recess  32  are formed in right lower positioning rail  28 . Generally adjacent to and spaced above right blade retraction recess  16  is right illumination recess  18  formed in upstanding peripheral wall  14 . Lower and upper right lamp retention angle lugs,  34 ,  36  are located inwardly and rearwardly adjacent right illumination recess  18 . Battery support  38  comprising battery support ridges  40  extending radially from negative battery contact retention surround  42  having negative battery contact retention aperture  44  formed therein. Outermost ends of battery support ridges  40  have battery location lugs  50  formed thereupon. Right illumination switch recess  20  is formed in upstanding peripheral wall  14  rearwardly of battery support  38  with recessed right switch retention ridge  52  disposed inwardly adjacent thereto with right retention lug  54  being spaced inwardly and closely adjacent therefrom. 
         [0021]    In  FIG. 2 , it can be appreciated that many of the structures in left-hand housing half  212  are mirror images of the corresponding structures in right-hand housing half  12  and are numbered similarly but increased by  200  to distinguish them from structures in right-hand housing half  12 . However, structure corresponding to battery support  38  is unnecessary in left-hand housing half  212  while positive battery contact retention surround  56  is formed between left illumination recess  218  and left illumination switch recess  220 . 
         [0022]    Returning to  FIG. 1 , lamp  58 , transparent lamp cover  60 , battery  62 , illumination switch  64 , illumination switch cover  66 , positive battery contact  68 , negative battery contact  70  and retractable blade assembly  72  are displayed in disposition congruent to their relative positions in the assembled compact ergonomic lighted retractable seam ripper  10  as seen in  FIG. 2 . Retractable blade assembly  72  comprises seam ripping blade  74  having tapered lower projection  76  and balled upper projection  78  with U-shaped cutting-edge  80  disposed therebetween. Seam ripping blade  74  is carried upon blade holder/guide  82  having left and right slots  84 ,  86  respectively adapted to engage right and left upper positioning rails  26 ,  226  and translate thereupon. As best shown in  FIGS. 5, 6 and 7 , locking spring  88 , preferably formed integrally with bladeholder/guide  82  desirably comprises a vertically extending riser portion  90 , the upper end  92  of which is joined to horizontally and longitudinally extending spring arm portion  94  having an upwardly extending support stanchion  96  integrally attached to a rearward portion of horizontally and longitudinally extending spring arm portion  94 , a downwardly extending positioning projection  98  attached to a forward portion of said horizontally and longitudinally extending spring arm portion  94 . Lower end  100  of vertically extending riser portion  90  extends exteriorly to compact ergonomic lighted retractable seam ripper  10  and is secured, preferably integrally, to positioning tab  102 . Support stanchion  96  of locking spring  88  is fixed, preferably integrally, to blade holder/guide  82 , while locking projection  98  is adapted to project through blade stop recesses  30 ,  32  in lower positioning rails  28 ,  228  with locking spring riser  90  riding between lower positioning rails  28 ,  228  extending longitudinally in compact ergonomic lighted retractable seam ripper  10  with positioning tab  102  being attached to locking spring riser  90  and residing in right and left elongated inwardly displaced positioning slot recesses  22 ,  222  formed by the left and right positioning recesses  24 ,  224 . Horizontally and longitudinally extending spring arm portion  94  bears against lower positioning rails  28 ,  228  while locking projection  98  also riding upon lower positioning rails  28 ,  228  between forward and rearward blade stop recesses  30 ,  32 . Downwardly extending positioning projection  98  formed in horizontally and longitudinally extending locking spring portion  94  is urged downwardly against lower positioning rails  28 ,  228  by spring action, and is adapted to be lodged within either forward or rearward blade stop recesses  30 ,  32  remaining fixed therein until dislodged by upward pressure against positioning tab  102 , whereupon retractable blade assembly  72  is free to translate upon upper positioning rails  26 ,  226  until positioning projection  98  engages either of blade stop recesses  30 ,  32 . Transparent lamp cover  60  having lamp  58  disposed therein is lodged between right and left illumination recesses  18 ,  218  and right and left lamp retention angle lugs  34 ,  36 ,  234 ,  236 . Illumination switch  64  inside illumination switch cover  66  is positioned between right and left recessed switch retention ridges  52 ,  252  and bears against switch retention lugs  54 ,  254 . Positive and negative battery contacts  68 ,  70  are lodged within negative and positive battery contact retention apertures  44 ,  56  while wiring (not shown) operatively connects both battery  62 , contacts  70 ,  68  with lamp  58  and illumination switch  64  so that lamp  58  can be illuminated by manipulation of illumination switch  64 . Optionally, right and left thermoplastic elastomer pads  104 ,  106  may be exteriorly attached to housing sidewalls  12 ,  212  to ease gripping thereof. Housing sidewalls  12 ,  212  may be formed from polypropylene or any other convenient polymer by injection molding and joined to each other by ultrasonic welding. 
         [0023]      FIG. 2  illustrates compact ergonomic lighted retractable seam ripper  10  with seam ripping blade  74  projecting therefrom, while  FIG. 3  illustrates the retracted conformation. Desirably, compact ergonomic lighted retractable seam ripper  10  has a thickness of between about 0.25 inches and 0.85 inches, an overall length of between 1¼ inches and 4 inches with the blade retracted so that it may be easily grasped between the thumb and forefinger of either hand. Desirably, the upper periphery of the housing is generally arcuate having a smooth profile with a radius of curvature of between 0.75 inches and 2.25 inches while the lower periphery is generally planar. More preferably at least a portion of the generally arcuate surface is generally in the form of the outer surface of a partial annulus or more precisely, a partial torus. 
         [0024]      FIGS. 8 and 9  illustrate the outer appearance of a compact ergonomic lighted retractable seam ripper  310  in seam ripping blade  378  is disposed so that tapered lower projection  376  is no more than ⅜ of an inch, preferably no more than 5/16 and most preferably no more than ¼ inch, above the lower surface of housing  312 . Decreasing the clearance between tapered lower projection  376  and the lower surface of housing  312  greatly increases the ease with which compact ergonomic lighted retractable seam ripper  310  may be used. In  FIGS. 8 and 9  seam ripping blade  378  is retracted and advanced by manipulation of positioning tab  302  riding in positioning trench  323 . Lamp  358  (see  FIGS. 10 and 11 ) behind transparent lamp cover  360  is functionally identical to the lamp described in previous embodiments as is illumination switch  364  and battery  362 . Thermoplastic elastomer pads  304  (not visible) and  306  are provided as before to facilitate easy gripping. 
         [0025]      FIGS. 10 and 11  are sectional views illustrating the inner workings of compact ergonomic lighted retractable seam ripper  310  in which upper guide rail  326  extends substantially the length of housing  312  bearing against spring  388  integrally formed with blade holder  382 , lower surface of which bears against generally planar bottom  329  of housing  312  having positioning slot  322  formed therein through which positioning tab  302  protrudes riding in positioning trench  323  in the lower surface of housing  312  (see  FIG. 8 .) Locking projection  398  formed on the lower surface of positioning block  382  and projecting laterally outward from positioning tab  302  can be selectively engaged with either rear positioning detent  332  or forward positioning detent  330 . When as in  FIG. 10 , locking projection  398  engages rearward recess  332 , blade  378  is retained within housing  312 . Inward and forward pressure on positioning tab  302  dislodges locking projection  398  from rearward locking detent  332  allowing blade holder  382  to traverse positioning slot  322  whereupon locking projection  398  engages forward positioning detent  330  yielding a configuration shown in  FIG. 11  in which blade  378  projects 27.754 mm from housing  312  being spaced only  6 mm above the lowermost point on positioning tab  302 . Desirably spring  388 , blade support block  382 , including locking projection  398 , and positioning tab  302  are integrally formed from a single piece of Delrin, also known as acetal or Poly(oxymethylene) glycol by injection molding yielding a strong tough lubricious piece which easily slides back and forth in positioning slot  322  in housing  312 . 
         [0026]      FIG. 12  illustrates another embodiment of the invention in which normally off contact switch  402 , consisting of conductive contact plates  404  and  406  held apart by spring  408 , is interposed between left-hand housing half  212  and left-hand thermoplastic elastomer pad  106  so that lamp  58  is only illuminated when compact ergonomic lighted retractable seam ripper  10  is grasped in use to preclude pre-mature exhaustion of battery  62 . 
         [0027]    While the invention has been described in detail, modifications within the spirit and scope of the invention will be readily apparent to those of skill in the art. In view of the foregoing discussion, relevant knowledge in the art and references discussed above in connection with the Background and Detailed Description, the disclosures of which are all incorporated herein by reference, further description is deemed unnecessary. In addition, it should be understood that aspects of the invention and portions of various embodiments may be combined or interchanged either in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.