Abstract:
A handle and a method of fabricating a handle, or another article of manufacture, that minimizes or avoids the likelihood of accumulating contamination before, during, or after use. The article includes a core element, for example, a plastic core element, having an outer surface and raised indicia, such as, letters or logos, extending beyond the outer surface; and a light-transferring material completely covering the raised indicia of the core element wherein the raised indicia are visible through the light-transferring material. The complete covering of the indicia avoids separation between the cover and the indicia. The cover material may be a translucent thermoplastic elastomer. Though particularly applicable to the medical device industry, aspects of the invention may be applied to a broad range of industries.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to articles of manufacture and methods of fabricating those articles, for example, handles. More particularly, the present invention relates handles, for example, handles for medical devices, and methods of fabricated handles having a core with human readable indicia and a translucent cover through which the indicia can be read. 
     2. Description of Related Art 
     In the art of medical devices, there are many types of handles and handle-like structures formed by molding and over molding, for example, molding a first material over a second or core material. Often, some form of logo or insignia is provided on the core material that is exposed, and thus viewable, after over molding. This is typically achieved by providing an over molded material having and outer surface that is substantially tangent to the surface of the logo or insignia. However, since the core material and the over molded material are typically of different composition, the interface between the over molded material and the logo or insignia is susceptible to separation. Typically, such separation can provide an ideal location for dirt and microbes to congregate and spread. Clearly, a need exists in the art to avoid such separations, especially, in the field of medical devices. 
     The prior art discloses various handle structures having over molded logos or insignia. For example, U.S. Pat. No. 6,749,790 issued to Lieser, et al. discloses a handle formed from a shank over molded with a core of a polypropylene and then over molded with a thermoplastic elastomer. U.S. Pat. No. 6,726,868 issued to Panfili, et al. discloses a double molding process for producing a “sign” or logo in a handle. U.S. Published Patent Application No. 2007/0186453 A1 issued to Little, et al. discloses a toothbrush that has a thermoplastic elastomer molded to a handle and completely seals an image pocket. U.S. Published Patent Application No. 2004/0121671 A1 issued to Skedeleski discloses a fin construction having registration posts for over molding a flexible material. U.S. Pat. No. 6,195,830 issued to Bruschi discloses a paintbrush handle having a core over molded with a soft thermoplastic rubber and having a raised part that penetrates the rubber. However, though these and other prior art references disclose some form of over molding about a structure, the structure or indicia over molded is invariably covered by the over molded material. That is, as is typical of the prior art, the over mold material simply abuts, and does not seal, whatever is projecting from the core of the handle. 
     However, none of the prior art discloses an over molded article construction with encapsulated logo or insignia that avoids the undesirable separation discussed above. Aspects of the present invention address this and other limitations of the prior art. 
     SUMMARY OF THE INVENTION 
     According to aspects of the present invention articles of manufacture and methods of fabricated articles of manufacture, for example, medical device handles, are provided which avoid or prevent the undesirable separation of the over molded material from the logo or insignia by substantially completely covering the logo or insignia on the core with a translucent material. As a result, the logo or insignia is visible through the translucent material without providing interfaces that may separate between the over molded material and the logo or insignia. 
     One aspect of the invention is a method for fabricating an article, for example, a handle, the method comprising or consisting of providing a core element having an outer surface and raised indicia extending beyond the outer surface; and molding a light-transferring material over the raised indicia of the core element wherein the light-transferring material completely covers the raised indicia, and wherein the raised indicia are visible through the light-transferring material. The raised indicia may be raised letters, numerals, symbols, characters, designs, logos, pictures, decorations, or a combination thereof. In one aspect the light-transferring material, for example, a translucent or transparent material, may completely cover the raised indicia wherein no gaps are provided on an outer surface of the article between the raised indicia and the light-transferring material. The light transferring material may typically be an elastomeric material having a softening point of at least about 100 degrees C., for example, a translucent GLS Kraton® thermoplastic elastomer, or its equivalent. 
     Another aspect of the invention is an article of manufacture, for example, a handle, comprising or consisting of: a core element having an outer surface and raised indicia extending beyond the outer surface; and a light-transferring material completely covering the raised indicia of the core element wherein the raised indicia are visible through the light-transferring material. Again, the raised indicia may be one or more of the indicia described above. In one aspect, the light-transferring material completely covers the raised indicia wherein no gaps are provided on an outer surface of the article between the raised indicia and the light-transferring material. Again, the light-transferring material on this article may be a translucent and a transparent material, for example, a translucent thermoplastic elastomer, such as, GLS Kraton® thermoplastic elastomer. 
     These and other aspects, features, and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be readily understood from the following detailed description of aspects of the invention taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of a handle for a medical device according to the prior art. 
         FIG. 2  is a perspective view of a detail of the prior art handle shown in  FIG. 1  identified by Detail  2  in  FIG. 1 . 
         FIG. 3  is perspective view of core element prior to over molding according to one aspect of the invention. 
         FIG. 4  is a perspective view of a handle according to an aspect of the present invention after over molding the core element shown in  FIG. 3 . 
         FIG. 5  is a perspective, cross-sectional view of the handle shown in  FIG. 4  as sectioned along lines  5 - 5  in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of a handle  10  for a medical device according to the prior art. As is typical of the prior art, handle  10  comprises an elongated member adapted to be grasped and manipulated by the user, for example, the surgeon. Handle  10  typically has a first, free end  12  and a second end  14  to which a tool shaft  16  (a representative portion of which is shown in phantom) is typically mounted, for example, a surgical boring tool and the like. The handle  10  typically comprises an elongated core element  18  shaped and contoured to facilitate handling. In order to enhance the users grasp of the handle  10 , core element  18  may be covered, for example, over molded, with a cover  20 , for example, a cover made of an elastomeric material having increased frictional properties, that is, typically increased frictional properties compared to the material of core  18 . The material of cover  20  may be, for example, a thermoplastic elastomer or a thermoplastic polyurethane. The cover  20  typically enhances the grippability of tool  10 . 
     In addition, it is common for marketing information or indicia  22  to be provided on handle  10 , for example, the name of the handle manufacturer or the name of the facility at which tool  10  is used. As is typical, as in the case shown in  FIG. 1 , the indicia  22  are provided as raised letters on the surface of the core  18 . The raised indicia  22  are then typically over molded with cover  20  whereby the surface of the raised indicia  22  and the surface of the over molded cover  20  are substantially co-planar. In other words, raised indicia  22  typically penetrate cover  20  and the surface  23  of indicia  22  are exposed to the external environment. Though such exposed over molded indicia may provide enhanced definition or visibility to the indicia  22 , the penetration of cover  20  by indicia  22  can have undesirable disadvantages, especially when handle  10  used as a medical device. 
       FIG. 2  is a perspective view of a detail of the prior art handle  10  shown in  FIG. 1  identified by Detail  2  in  FIG. 1 . As shown in  FIG. 2 , since indicia  22  penetrate through cover  20 , an interface  24  between indicia  22  and cover  20  is typically present. Because the core  18  (typically, harder and more rigid) and cover  20  (typically, softer and more pliable) are typically of different materials, there is typically no bonding between the cover  20  and the indicia  22  at interface  24 . Since the interface  24  is typically not bonded, one or more separations  26  between indicia  22  and cover  20  are often encountered on over molded handles having raised indicia. The separation  26  can be exacerbated by repeated handling, for example, by the surgeon, and due to the extreme temperature variations the handle  10  is typically exposed to, for example, during high temperature sterilization. However, the undesirable disadvantage of separation  26  is the potential home separation  26  can proved for undesirable substances or organisms. For example, such crevices provided by separation  26  can be ideal locations for microbes to gather and propagate. This is especially true in hospital environments in which medical devices having these prior art handles are typically used. Of course, separation  26  in  FIG. 2  is only a representative separation identified for the sake of this disclosure. Interface  24  is present wherever cover  20  abuts a character or image of indicia  22  and separation  26 , and its potential to accumulate germs and bacteria, may be found anywhere and everywhere along interface  24  of handle  10 . Aspects of the present invention, address this undesirable limitation, among others, of the prior art. 
       FIG. 3  is perspective view of core element  30  prior to over molding according to one aspect of the invention. Core element  30  may be metallic or non-metallic, including plastic or wood, but core element  30  is typically made from a plastic or a plastic mounted on a metallic inner core, as shown in  FIG. 5 . In one aspect, core element  30  may be made from a polypropylene, a polycarbonate, or a acrylonitrile butadiene styrene (ABS), for example, injection molded from a polypropylene or a polycarbonate. Core element  30  may also be shaped to provide comfort and compatibility with the grasp of the user, including ridges and bulbous ends to facilitate handling by the user. 
     As shown in  FIG. 3 , elongated, uncovered core element  30  may typically include a tool shaft  31  projecting from core element  30  and having a tool end or adapted to receive a tool. Though in  FIG. 3 , tool shaft  31  projects radially about a centerline of core element  31 , one or more tool shafts  31  may project from anywhere along core element  31 , including projecting axially from an end of core element  31  as shown by tool shaft  16  in  FIG. 1 . 
     According to aspects of the invention, core element  31  typically comprises an outer surface  32  and raised indicia  34  that extend beyond the outer surface  32  of core element  30  and provide one or more surfaces  36  above the surface of outer surface  32 . As used in this specification and claims the term “indicia” refers to any mark intended to convey information to the viewer. For example, indicia may include letters, numerals, symbols, characters, designs, logos, pictures, decorations, or combinations thereof, among other means of relaying information to the viewer. As also shown in  FIG. 3 , core element  30  may also include one or more additional areas  38  having raised surfaces, that is, areas raised above the surface of surface  32 , that, as will be discussed below, may provide a retention mechanism for the cover of handle  30 . As shown in  FIG. 3 , additional raised areas  38  may be positioned on bulbous ends  39  of core element  30 . 
       FIG. 4  is a perspective view of a handle  40  according to an aspect of the present invention after over molding the core element  30  shown in  FIG. 3  with a material or cover  42 . According to aspects of the invention, cover  42  may comprise an elastomeric material, for example, to provide a resilient, comfortable grip, having enhanced friction that resists slippage from the user&#39;s hand, for example, when exposed to blood or another bodily fluid during surgery. The elastomeric material may be a light-transferring material, that is, material that may be at least partially translucent, for example, through which indicia  34  may be at least partially visible. In addition, in one aspect of the invention, the elastomeric may have a softening point above the temperature handle  40  is typically exposed to, for example, a softening point of at least 100 degrees C., but may have a softening point above 150 degrees C. or 200 degrees C. When handle  40  is used on a medical device, in one aspect, the elastomeric material from which cover  42  is made may have a softening point temperature greater than at least 250 degrees C., that is, greater than the temperature a medical device is likely to be exposed to during sterilization, for example, in an autoclave or similar sterilization device. In another aspect, the elastomeric material from which cover  42  is made may have a softening point temperature greater than at least 300 degrees C. 
     In one aspect, cover  42  may comprise a thermoplastic elastomer (TPE) (also known as thermoplastic rubbers). Typical TPEs that may be used for cover  42  include, but are not limited to, Styroflex® styrene-butadiene copolymer provided by BASF, Kraton® TPE provided by GLS, Pellethane™ polyurethane provided by Dow Chemical, Pebax® polyether block amide provided by Arkema, Arnitel copolyester provided by DSM, and Hytrel polyester provided by Du Pont, or their equivalents. According to aspects of the invention, the material from which cover  42  is made may typically be at least somewhat translucent whereby indicia  34  may be at least partially visible through the cover. In one aspect, the material of cover  42  may be substantially translucent, and may be substantially transparent, whereby indicia  34  may clearly be seen through cover  42 . Cover  42  may include a shade or coloring, for example, a translucent blue or translucent red, among other translucent colorings. In one aspect of the invention, a translucent or transparent grade of GLS Kraton® TPE may be used for cover  42 , for example, GLS&#39;s G2705 TPE, or its equivalent. 
     As shown in  FIG. 4 , and contrary to the prior art, indicia  34  on core element  30  do not penetrate the surface of cover  42 . That is, contrary to the prior art, no interfaces between the indicia  34  and the cover  42  are present, for example, no interfaces  24  in  FIG. 2  that are susceptible to separation  26  are present in handle  40 . Accordingly, according to aspects of the invention, handle  40  may be devoid of and unlikely to obtain any separations  26  that can be locations where microbes can accumulate and propagate. That is, aspects of the present invention provide a marked sanitary improvement over existing handle structures, especially for handles for medical devices. 
       FIG. 4  also illustrates raised areas  38 , for example, on bulbous ends  39 , of handle  40 . According to one aspect, of the invention, raised areas  38  may be provided that project above the surface  32  of core element  30  and which are not covered by cover  42 . In one aspect, raised areas  38  may be positioned anywhere along handle  40  to provide an obstruction to the movement of cover  42  with respect to core element  30 . For example, in one aspect, raised areas  38  have a height that is about equal to the thickness of cover  42 . Raised areas  38  may also be slightly higher or lower than the thickness of cover  42  whereby raised areas  38  project beyond cover  42  or are recessed below the surface of cover  42 . In one aspect, no raised areas  38  are present to minimize or eliminate any possible separation of cover  42  from a raised area  38 . 
       FIG. 5  is a perspective, cross-sectional view of handle  40  shown in  FIG. 4  as sectioned along lines  5 - 5  shown in  FIG. 4 .  FIG. 5  includes a cross-section of core element  30 , cover  42 , and raised indicia  34  according to one aspect of the invention. As shown, cover  42  may have a thickness  44 , which may range from about 0.010 inches to about 0.25 inches, but is typically between about 0.040 inches and about 0.180 inches, for example, between about 0.080 inches and about 0.130 inches. As also shown in  FIG. 5 , thickness  46  of cover  42  above the height of raised indicia  34  may range from about 0.010 inches to about 0.25 inches, but is typically between about 0.020 inches and about 0.120 inches, for example, between about 0.030 inches and about 0.080 inches. 
     As shown in  FIG. 5 , core element  30  may comprise a plurality of components, for example, an inner core  52 , an intermediate layer  54 , and an outer layer  56  providing the outer surface  32  of core  30 . Inner core  52  may be metallic, for example, steel, stainless steel, aluminum, or titanium, among other metals, or plastic, for example, one or more of the plastics disclosed herein. Inner core  52  may provide the structural rigidity typically required for a handle, and may be adapted to receive tool shaft  31  shown in  FIG. 3 . Intermediate layer  54  may also be a plastic, for example, one or more of the plastics disclosed herein, but may typically be made from a polypropylene, a polycarbonate, or an acrylonitrile butadiene styrene (ABS). Outer layer  56  may also be a plastic, for example, a polypropylene, a polycarbonate, or an ABS. In one aspect, intermediate layer  54  and outer layer  56  may be made of the same material, for example, be both made from a polycarbonate. Moreover, intermediate layer  54  and outer layer  56  may not be separate components, but may comprise a single component made of one material, for example, a polycarbonate. 
     In one aspect of the invention, a method for fabricating an article, for example, a handle  40  is provided. The method includes or comprises providing a core element  30  having an outer surface  32  and raised indicia  34  extending beyond the outer surface  32 ; and molding a light-transferring material  42  over the raised indicia  34  of the core element  30  wherein the light-transferring material  42  completely covers the raised indicia  34 , and wherein the raised indicia  34  are visible through the light-transferring material  42 . In one aspect, the light-transferring material  42  completely covers the raised indicia  34  wherein no gaps or separations  26  (see  FIG. 2 ) are provided on an outer surface of the article  40  between the raised indicia  34  and the light-transferring material  42 . 
     It will be apparent to those of skill in the art that aspects of the invention provide a article of manufacture, for example, a handle, and method of fabricating articles of manufacture having human readable indicia that are not prone to harboring dirt or microbes by preventing the formation of interfaces that may be prone to separation. Though aspects of the invention may be applied to a broad range of over molded articles of manufacture, including, household products, sporting goods, tools, toys, and the like, it will be apparent that aspects of the invention are especially suitable for the manufacture of articles for medical devices, for example, handles for medical device. 
     While several aspects of the present invention have been described and depicted herein, alternative aspects may be effected by those skilled in the art to accomplish the same objectives. Accordingly, it is intended by the appended claims to cover all such alternative aspects as fall within the true spirit and scope of the invention.