Patent Abstract:
A handle for a tool is provided that is formed of a core positioned within a sleeve of a temperature resistant material to form a handle with a space between the core and the sleeve. The core can be formed by machining a metal material while the sleeve and an optional skin positioned on the sleeve can be molded. The materials forming the sleeve and skin, and the space formed between the core and sleeve, create a handle that can be adapted to form a variety of different tools with different mechanisms located in the core that also has improved heat transfer characteristics for sterilization purposes.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. Ser. No. 13/709,952, filed Dec. 10, 2012, which claims priority from U.S. Provisional Application Ser. No. 61/568,231 filed on Dec. 8, 2011, the entirety of which is expressly incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to handles for tools and more specifically to handles for medical devices that are subjected to harsh environments, such as handles which are periodically placed within an autoclave for sterilization purposes. 
     BACKGROUND OF THE INVENTION 
     There are many types of handles for tools of different types. These handles cam include within them various devices and mechanisms that enable the handle to perform various functions for the tools formed with the handle. 
     Many of these types of handles are used in situations that require that the handle be able to withstand very harsh environments during use of the tool or during cleaning of the tool. One example of handles of this type is a handle for a medical tool that must be sterilized by placing the handle in an autoclave. In the autoclave the handle is subjected to high temperature steam that effectively sterilizes the surfaces of the handle on which bacteria and other undesirable organisms may be located. 
     With prior art handles, the handle is normally formed with a central core formed of a single piece of a suitable material, such as a rigid metal. The metal core is machined and shaped as necessary to provide the desired structure for the various internal configuration or components for the tool to be positioned within the core. The shaping of the tool often requires that the core be intricately cut in a number of different sequential steps in order to achieve the desired shape to accommodate the particular configuration or shape of the components to be positioned within the core, which can greatly increase the costs and time required for creating the handle core. 
     Further, once machined into the desired configuration, the core of the tool is often formed with a molded material disposed around the exterior of the central core in order to provide the desired grip and aesthetic or appearance characteristics to the handle. To provide these characteristics to the handle, the molded material is formed in varying thicknesses on the exterior of the core. In most constructions, the molded layer is formed from an insulating type material, such as a silicone, which provides a desirable feel to the tool, while also being able to be formed with the desired shape around the core. 
     However, in those situations where the tool is required to be sterilized such as in an autoclave, the placement of the molded material directly around the exterior of the core can inhibit the transmission of heat from the exposed ends of the core to the interior of the core as a result of the insulating properties of the molded material. As a result, certain areas of the core may not be reached by the steam in order to achieve the necessary temperature for effective sterilization of the entire handle which can prevent the handle from being able to be used for its intended purpose. 
     Thus, it is desirable to develop a handle that can be formed with an outer molded layer of a suitable material that provides the desired characteristics to the handle while also enabling effective heat transfer to the entire core in order to quickly and effectively sterilize the core and the entire handle. 
     SUMMARY OF THE INVENTION 
     Briefly described, one aspect of the present disclosure provides a handle having a central core formed of a heat conducting material within which can be positioned any number of various types of mechanisms suitable for providing the desired utility for the tool. The core is positioned within a moldable sleeve of a relatively thin walled heat tolerant material having a relatively constant thickness. The sleeve includes interior features that enable the central core to be effectively positioned within and mated to the sleeve in the correct position. The sleeve also includes exterior features, and/or an exterior shape that enables an outer skin formed of the moldable, insulating material, such as silicone, placed on the exterior of the sleeve to have a relatively constant thickness across the entire length of the sleeve. In the assembled configuration, the core is held within the sleeve by an end cap engaged with the core and extending over the sleeve and the exterior of the skin. 
     In this configuration, the core and sleeve define an air space between the core and the sleeve that enables more effective heat transfer along the entire length of the core. This insulating effect of the skin on the core is consequently reduced as a result of the presence of the space and the more consistent thickness of the skin on the exterior of the sleeve. As a result, when the handle is disposed in an autoclave for the purposes of sterilizing the handle, the steam can more quickly raise the temperature of the core to enable the handle to be effectively heated and sterilized within the predetermined treatment cycles of the autoclave, even a high speed autoclave. 
     According to another aspect of the present disclosure, the core is formed with engagement surfaces for connecting and mating with sleeves having complementary surfaces, but the sleeves can be formed with any desired shape between the complementary surfaces. As a result, the same core configuration can be used with sleeves of various shapes. 
     According to still another aspect of the present disclosure, because the core is formed with a relatively simple and consistent configuration, regardless of the configuration of the remainder of the handle, the core can be formed with a variety of mechanisms for providing the desired utility for the handle. 
     Numerous other aspects, features, and advantages of the present invention will be made apparent from the following detailed description together with the drawings figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode currently contemplated of practicing the present invention. 
       In the drawings: 
         FIG. 1  is an isometric view of a one embodiment of a handle constructed according to the present disclosure; 
         FIG. 2  is a side isometric view of the handle of  FIG. 1 ; and 
         FIG. 3  is a cross-sectional view along line  3 - 3  of  FIG. 2 ; 
         FIG. 4  is a partially exploded, cross-section isometric view of the handle of  FIG. 3 ; 
         FIG. 5  is an isometric, cross-sectional view of the sleeve and skin of the handle of  FIG. 4 ; 
         FIG. 6  is a side plan, cross-sectional view of the sleeve and skin of  FIG. 5 ; 
         FIG. 7  is an exploded, isometric cross-sectional view of the sleeve and skin of  FIG. 6 ; 
         FIG. 8  is an isometric, cross-sectional view of the sleeve of  FIG. 5 ; and 
         FIG. 9  is an isometric view of the core of the handle of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views, one embodiment of a handle constructed according to the present disclosure is illustrated generally at  10  in  FIG. 1 . As best shown in  FIGS. 1-4 , this embodiment of the handle  10  is formed of a central core  12 , a sleeve  14  disposed around the core  12 , an outer skin  16  formed around the sleeve  14 , and an end cap  18  engaged with one end of the core  12  and extending over the sleeve  14  and outer skin  16 . 
     Referring now to  FIGS. 1-4 and 9 , the core  12  is shaped to accommodate a particular mechanism  100  therein, such as a ratcheting mechanism, a torque-limiting mechanism, or a variable gear ratio driving mechanism among others, such as those disclosed in one or more of U.S. Pat. Nos. 6,817,458; 7,430,945; and/or U.S. Patent Application Publication No. US2010/0294084, which are each expressly incorporated by reference herein in their entirety. In the illustrated embodiment, the core  12  is formed with a generally tubular configuration with a wide first end  20  and a wide second end  22  joined by a narrow central passage  24 . The first end  20  is shaped in a suitable machining process to accept any of a number of mechanisms therein to provide the desired utility for the handle  10 . The first end  20  is configured to closely conform to the shape of the particular mechanism, and alternatively can be formed to be connectable to a number of different mechanisms in an interchangeable manner. A shaft  102  of a suitable implement can be inserted through the second end  22  along the passage  24  into engagement with mechanism disposed within the first end  20 . 
     The second end  24  is also shaped in a suitable machining process to be able to accept any of a number of shaft securing mechanisms therein, in order to releasably secure the implement shaft within the core  12  in engagement with the mechanism disposed in the first end  22  of the handle  10 . 
     The exterior of the first end  20  and the second end  22  are formed with engaging surfaces  25 ,  26 , respectively, capable of contacting and engaging or mating with complementary surfaces  28  on the interior of the sleeve  14  to lock the core  12  in position with regard to the sleeve  14 . In addition, both the first end  20  and the second end  22  extend beyond the ends of the sleeve  14  in order to facilitate the connection of the handle  10  to other components of the manufacture of the handle  10 . 
     In the illustrated embodiment, the core  12  is formed as a single piece of a suitable material, such as stainless steel, that is capable of being sterilized effectively through the application of heated steam to the core  12 , such as in an autoclave. In an alternative embodiment, the core  12  can be formed with the first end  20  and the second end  22  being separate from the passage  24 , and the subsequently connected in any suitable manner to the respective ends of the passage  24 , which in the illustrated embodiment has a diameter less than that of the first end  20  and the second end  22 . In this embodiment, the first end  20  and second end  22  can be shaped to conform to a particular mechanism to be placed therein, further enhancing the ability of the core  12  to be adapted for particular uses of the handle  10 . The core  12  has a diameter much less than the diameter of the sleeve  14  in order to greatly reduce the amount of material required for the formation of the core  12  and to provide a space  30  between the exterior of the core  12  and the interior of the sleeve  14  in the finished construction of the handle  10 . 
     In either embodiment for the core  12 , the configuration of the core  12  requires a minimum of separate machining steps, greatly reducing the amount of time required for the formation of the core  12 . 
     Looking now at  FIGS. 3-8 , in the illustrated embodiment the sleeve  14  is formed as a hollow, generally tubular member having a front end  32  and a rear end  34 . The front end  32  includes an inwardly tapering engagement ridge  36  and the rear end  34  includes a radially inwardly extending engagement flange  38 . The engagement ridge  36  and the engagement flange  38  are shaped complementary to the engagement surfaces  25 ,  26  on the first end  20  and second end  22  of the core  12  in order to securely seat the core  12  within the sleeve  14 . 
     The sleeve  14  is formed from a material that is heat resistant, meaning that the material can withstand the temperatures and/or pressures used to sterilize the handle  10 . This material can be the same as that used for the core  12 , or can be a different material. In certain embodiments, the sleeve  14  can be formed from a material such as metal, including aluminum, among others, or a plastic material. 
     When formed of these types of materials, especially plastic materials, the sleeve  14  can be formed by molding the material forming the sleeve  14  into the desired shape, which greatly reduces the amount of the material required and the time necessary to form the sleeve  14 . Additionally, the sleeve  14  can be formed by hydroforming, stamping or in other similar processes, also resulting in significant reductions on used material and time for forming the sleeve  14 . Also, because the sleeve  14  is formed according to one of these less intricate procedures, the sleeve  14  can be formed with more intricate shapes to enhance the desired attributes of the handle  10 , as well as with a more uniform thickness along the length of the sleeve  14 . This is especially true when the sleeve  14  is molded, as the mold can be designed with the particular form desired for the sleeve  14  to enable the sleeve  14  to be readily reproduced in a simple molding process. In addition, this more uniform thickness of the sleeve  14  along its length further speeds up the curing time for the sleeve  14 , consequently speeding up the overall manufacturing process for the handle  10 . 
     The outer skin  6  that is positioned on the exterior of the sleeve  14  is formed of any suitable material, such as a silicone material. The skin  16  is molded directly onto the sleeve  14  which is placed within the mold for the skin  16 , with the material used to form the skin subsequently injected into the mold around the sleeve  14 . Due to the shape of the sleeve  14  which, as a result of its construction and method of formation can be formed to more closely conform to the desired shape for the handle  10 , the amount of material required to be injected around the sleeve  14  to term the skin  16  is greatly reduced. This consequently reduces the insulating ability of the skin  16  on the handle  10 , thereby increasing the heat transfer along the handle  10 . In one embodiment, the thickness of the material forming the skin  16  can be less than 15 mm, and in another embodiment can be less than 10 mm, and in still another embodiment can be less than 6 mm. The thickness of the skin  16  can also vary in one or both of the radial and axial directions of the handle  10  to provide the desired shape to the skin  16  and the handle  10 , and in one embodiment the skin  16  can vary in thickness between about 0 mm and about 12 mm, and in another embodiment can vary between about 1 mm and about 8 mm, and in still another embodiment can vary between about 1 mm and about 5 mm. 
     To assist in holding the core  12  within the finished sleeve  14  and skin  16 , once properly seated within the sleeve  14 , the second end  22  of the core  12  is engaged with an inner member  40  of the end cap  18 . The inner member  40  is formed to be generally tubular in shape and is positioned in alignment with the passage  24  in the core  12  to enable the shaft to pass through the inner member  40  of the cap  18  and the passage  24  of the core  12  for engagement with the mechanism disposed within the first end  20  of the core  12 . In the illustrated embodiment, to hold the inner member  40  within the second end  22  of the core  12  the inner member  40  has a threaded outer surface  42  that is engaged with a complementary threaded surface  44  on the interior of the second end  22  of the core  12 , though other suitable engaging mechanism as are known in the art can be utilized as well. 
     The end cap  18  also includes an outer member  46  that functions to engage the exterior of the skin  16  and sleeve  14  and hold the core  12  within the sleeve  14 . In the illustrated embodiment, the outer member  46  is conical in shape and extends axially outwardly from the inner member  40  in a direction that partially overlaps the inner member  40 . When the inner member  40  is engaged with the core  12 , an engagement surface  48  on the outer member  46  engages and compresses the skin  16  against the sleeve  14  while simultaneously drawing the second end  22  of the core  12  into secure and aligned engagement with the sleeve  14 . The end cap  18  can be formed from any suitable material, but in the illustrated embodiment is formed from a metal, such as stainless steel. 
     When fully assembled, the insulating effect of the skin  16  on the core  12  is consequently reduced as a result of the presence of the space  30  defined between the core  12  and the sleeve  14 /skin  16  and the more consistent thickness of the skin  16  disposed on the exterior of the sleeve  14 . As a result, when the handle  10  is disposed in an autoclave for the purposes of sterilizing the handle  10 , the steam can more quickly raise the temperature of the core  12  to enable the handle  10  to be effectively heated and sterilized within the predetermined treatment cycles of the autoclave, even a high speed autoclave. Further, with the construction of the handle  10 , the particular mechanism disposed within the core  12  can be removed from the care  12  to enable the core  12  to be more effectively sterilized. 
     In other alternative embodiments, the end cap  18  can be omitted or formed as a component of the core  12 , or the sleeve  14  and skin  16  can be formed as a single member, such that only one molding step is required to for the sleeve  14  or skin  16  to be secured around the core  12 . 
     In still other alternative embodiments, the space  30  between the exterior of the core  12  and the interior of the sleeve  14  can be utilized to house any of a number of different devices or mechanisms to enhance the utility of the handle  10 , such as any of a number of electronic devices, among others. 
     Various other embodiments of the present disclosure are contemplated as being within the scope or the filed claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.

Technology Classification (CPC): 1