Abstract:
A process for producing molded products having portions formed with two separate materials is provided. The process involves forming a first component over a structural core in a first step, and forming a second component that is secured to the first component and the core in a second step. The second component can be formed directly over the first component or can be secured thereto after formation. The first and second components can additionally be formed with indicia thereon, or with recesses within which inserts containing the desired indicia can be positioned. Additionally, the first component can be formed with a ridge disposed on a projection formed on the first component that effectively seals off a portion of the first component when the second component is formed around the core and the first component to ensure the portion of the first component surrounded by the ridge remains visible after formation of the second component.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority as a continuation of U.S. Non-Provisional patent application Ser. No. 12/538,439, filed on Aug. 10, 2009, now U.S. Pat. No. 8,641,955, issued on Feb. 4, 2014, which in turn claims priority from U.S. Provisional Application Ser. No. 61/087,365 filed on Aug. 8, 2008, the entirety of which are each expressly incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to molded items, such as handles for various types of tools such as tools utilized in the medical industry including torque wrenches, and, more specifically, to an item having an exterior formed from a two step molding process to provide the desired appearance and properties to the item. 
       BACKGROUND OF THE INVENTION 
       [0003]    Many different types of items are formed from molded components. These components are formed in molding processes that use a desired material in fluid form that is introduced into a mold to be shaped and solidified into the desired to form the item. However, in many of these processes, the item is limited to being formed from only a single type of material, due to various constraints, including the types of material being utilized in the molding process. 
         [0004]    In order to provide various items with improved aesthetic and utilitarian properties, many items have previously been formed from or with multiple molded components. In these items, the components are normally formed separately from one another and later mechanically interlocked with one another, or otherwise secured to one another to form the item or a portion of the item. On many occasions, the manner in which the molded components are secured to one another often provides a less than desirable appearance and/or a less durable construction, as well as increasing the overall expense for the manufacturing and assembly of the components. 
         [0005]    In addition, in certain situations where the item having the multiple molded components is to be subjected to conditions far outside of normal environmental conditions the need for a durable item is paramount, such as in the medical field where molded items are often autoclaved to sterilize the items after use. This is because the conditions utilized to sterilize the items including the molded components can easily degrade or separate the components from one another, thereby damaging the item. In addition, should the components become separated from one another in any manner, that separation can enable various bacteria and other similar organisms to enter the separation present between the components and potentially prevent the item from being properly sterilized. 
         [0006]    Therefore, it is desirable to develop a process for molding an item, such as a tool for use in the medical field, with multiple molded components that provides a tool with the required durability for the molded components in the item, but that also provides a clean and aesthetically pleasing appearance to the item. 
       SUMMARY OF THE INVENTION 
       [0007]    According to one aspect of the present invention, the molding process involves providing a core for the item on which the various materials are to be molded. The core is positioned within a mold having the desired shape for the first molded component, and the material used to form that first component is subsequently injected, or otherwise introduced into the mold. The first component is formed with one or more structural features thereon that enable a second molded component formed of the same or a different material to be directly secured to the first component, such as in a subsequent molding process where the mold utilized in the subsequent process defines a desired configuration for the second component around the core and the first component. 
         [0008]    According to another aspect of the present invention, because the second molded component can be affixed directly to the first molded component in a variety of different manners, such as by molding the second component directly around and/or onto the first component, the materials utilized to form the first and second components can be selected to be easily adhered or affixed to one another and to provide the desired aesthetic appearance to the item. 
         [0009]    According to still another aspect of the present invention, the first and second components can be formed of materials having different colors, textures, and/or other properties to enhance the appearance and feel of the item formed from the first and second components. In addition, one or both of the molded components can be formed with various decorative features thereon that enable the components to more readily form the desired appearance for the item. 
         [0010]    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 
         [0011]    The drawings illustrate the best mode currently contemplated of practicing the present invention. 
           [0012]    In the drawings: 
           [0013]      FIG. 1  is an isometric view of a first embodiment of a tool handle constructed according to the present invention; 
           [0014]      FIG. 2  is an isometric view of the core used to form the handle of  FIG. 1 ; 
           [0015]      FIG. 3  is isometric view of a first component molded over the core of  FIG. 2 ; 
           [0016]      FIG. 4  is isometric view of a second molded component that is affixed to the first component of  FIG. 3 ; 
           [0017]      FIG. 5  is an isometric view of a second embodiment of a tool handle constructed according to the present invention; 
           [0018]      FIG. 6  is an isometric view of the core used to form the handle of  FIG. 5 ; 
           [0019]      FIG. 7  is isometric view of a first component molded over the core of  FIG. 6 ; 
           [0020]      FIG. 8  is isometric view of a second molded component that is affixed to the first component of  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, an item constructed according to the present invention is indicated generally at  100  in  FIGS. 1-4 . The item  100  is formed as a handle  102  that is used to house a suitable mechanism for a tool, such as a ratcheting or torque limiting mechanism, though other types of mechanisms or the omission of any operating mechanism is also contemplated. 
         [0022]    The handle  102  is formed with a core  104  that is formed from any desired and preferably rigid material, such as a metal or hard plastic. The core  104  has a shape corresponding to the desired usage of the item or handle  102 , and thus can have any desired shape, though ergonomic shapes for use on tools utilized in the medical industry are especially preferred. This core  104  is initially positioned within a mold conforming to the desired shape of a first component  106  to be formed around the core  104 . 
         [0023]    The first component  106  is formed on the exterior of the core  104  in any suitable manner, such as in a conventional molding process, and preferably by an injection molding process. The material used to form the first component  106  can be selected based on the desired properties for the first component  106 , such as resiliency, rigidity, tackiness, texture and appearance among others. The material used for the first component  106  also is selected based on its suitability for use in the particular molding process to be used Finally, depending upon the desired aesthetic appearance for the handle  102 , the material selected for use in forming the first component  106  is also selected or modified to have the desired color. 
         [0024]    Thus, to satisfy the above requirements for the first component  106 , the materials that can be utilized for the first component  106 , include, but are not limited to various types of thermoplastic and/or thermoset materials, such as silicone materials, and in particular silicone rubber materials. 
         [0025]    After the formation of the first component  106  on the core  104 , the handle  102  including the core  104  and the first component  106  is removed from that initial mold so that a second component  108  can be formed on the handle  102  that is at least partially complementary in shape with respect to the first component  106 . 
         [0026]    The second component  108  is formed in a separate mold having a configuration corresponding to the shape desired for the second component  108 , such as a conventional molding process, including, but not limited to injection molding. Additionally, the material or materials utilized to form the second component  108  include the same types of materials that can be used in forming the first component  106 . Also, the second component  108  is preferably formed of a material having a color different than that used to form the first component  106  to enhance the aesthetic appearance of the handle  102 . Further, depending upon the location and other optional purposes of the second component  108  the material or materials used to form the second component  108  can be selected to have different and/or complementary properties to the materials used to form the first component  106 . For example, the first component  106  can be formed of a material or materials that are more rigid when formed in the particular molding process. In contrast, the material selected for use in forming the second component  108  can be more flexible and/or tacky when formed in the particular molding process, to provide a different tactile feel to the second component  108  in comparison to the first component  106 . This tactile distinction, which can also be enhanced through the use of differently colored materials for the first component  106  an the second component  108 , can provide the handle  102  with a non-visual indication of the proper location for the hand of an individual on the handle  102  when utilizing a tool or other item incorporating the handle  102 . The different materials selected for use in forming the first component  106  and the second component  108  can also be selected based on other differing characteristics for the materials that provide a desired distinction on the resulting handle  102  or other item  100 , such as different wear characteristics, among others. 
         [0027]    In a first embodiment illustrated in  FIGS. 1-4 , the second component  108  is formed separately from the handle  102  including the core  104  and the first component  106 . The second component  108  is formed of the desired material to have a shape that is directly complementary to a portion of the first component  106 . Preferably, the second component  108  is formed to be an insert positioned within a recess  110  formed in the exterior of the first component  106 . The recess  110  can have any desired shape and/or configuration, such as including a number of projections  112  therein, and the second component  108  is formed to be directly complementary to that shape for the recess  110 , such as by having a number of apertures  114  formed therein through which the projections  112  can extend. 
         [0028]    In this embodiment, the second component  108  is affixed within the recess  110  of the first component  106  in any suitable manner, such as by mechanically fixing the second component  108  therein, such as by frictional contact of abraded portions or engagable portions of the components  106  and  108 , or by using a fastener (not shown) connected to one or both of the first component  106  and the core  104 , by adhering the second component  108  to the first component  106  utilizing a suitable adhesive, or by welding the second component  108  to the first component  106 , such as by thermal or sonic welding, among other suitable means for securing the second component  108  to the first component  106 . 
         [0029]    In this embodiment, there can also be more than one second component  108  secured to the first component  106 , with each of the second components  108  having the same or a different configuration from one another. It is also contemplated that each of the second components  108  can be formed from multiple sections or pieces, each of which is subsequently disposed an secured within the recess  110 . 
         [0030]    Referring now to  FIGS. 5-8 , in a second embodiment for the item  100 , the first component  106 , which is molded around the core  104  in a first mold (not shown) in the same conventional manner as described with regard to the first embodiment illustrated in  FIGS. 1-4 , includes a projection  116  extending outwardly from the first component  106 . The projection  116  includes a ridge  118  around its periphery that separates the inner portion  120  of the projection  116  from the outer portion  122 . Preferably, the ridge  118  has a configuration that enables the ridge  118  to separate the portions  120  and  122  from one another, as well as to provide a tactile locating feature on the exterior of the handle  102 . After the formation of the first component  106  on the core  104 , the core  104  and the first component  106  are placed in a second mold (not shown) for the forming of the second component  108  around the core  104  and the first component  106 , also in any of the aforementioned conventional manners. When the second mold is closed, the ridge  118  on the projection  116  is engaged by the second mold to effectively seal off the inner portion  120  of the projection  116  from the remainder of the interior of the second mold. Therefore, when the material used to form the second component  108  is introduced into the second mold, the material is prevented from flowing into the inner portion  120  of the projection  116  in the first component  106  due to the engagement of the ridge  118  with the second mold used to define and form the second component  108 . The ridge  118  can any suitable cross-sectional shape to enable it to effectively seal against the second mold, such as elliptical, oval, rectangular, square or triangular, but preferably, the ridge  118  is semicircular in cross-section, and has a radius of from 0-2 mm. with a radius of about 1 mm being especially preferred. Thus, as opposed to securing the second portion  108  to the first portion  106  as an insert within a correspondingly shaped recess  110 , as in the first embodiment, in this construction and method of forming the item  100 , the second component  108  is molded directly over the first component  106  while a part of the first component  106  is sealed off, such that part of the first component  106  remains visible through the second component  108 . This greatly reduces the complexity of forming the first component  106 , other than the projections  116 , because any imperfections in the remainder of the first component  106  are effectively covered by the second component  108 . Preferably, based on the requirement for the sealing capability of the ridge  118 , the materials used to form the first component  106  are chosen from those able to withstand the temperatures and pressures exerted during the molding process, and that are capable of forming a solid bond with the material forming the second component  108 . Particularly preferred materials are silicone rubber and similar materials. 
         [0031]    In this second embodiment, the number of projections  116  formed on the first component  106  can be varied as necessary or desired, depending upon the shape of the item  100  and the desired appearance for the item  100 . 
         [0032]    Additionally, in each of the above embodiments, the exposed portions of each of the first component  106  and second component  108  can include indicia  126  positioned thereon or therein. The indicia  126  can be formed directly into the respective first component  106  or the second component  108  during the molding process for these components, or can be formed as a third component  127  that is inserted within a complementary recess  128  disposed in the component  106  or  108 . 
         [0033]    In the configuration where the indicia  126  are formed directly within the component  106  and/or  108 , preferably the indicia  126  are formed as a raised or recessed section  130  of the component  106  and/or  108 . After formation, the section  130  can be further treated, such as by painting or placing another material within the section  130  to change the appearance of the section  130  from the surrounding material forming the first component  106  or the second component  108 . 
         [0034]    In the configuration where the section  130  is formed separately from the particular component  106  and/or  108 , the section  130  can be formed of any desired material with any desired color. Once formed, the section  130  can be inserted and secured within the recess  128  using any of the suitable means described previously regarding the attachment of the second component  108  to the first component  106  in the first embodiment of the invention. Additionally, the section  130  can have any desired shape, such as a fanciful design inserted into a complementary-shaped recess  128 , or a more conventional polygonal or circular shape that can including a particular design therein, such that a number of sections  130  can be created with a number of different designs thereon, but each section  130  having the same exterior profile to enable the sections  130  to be interchangeable. The sections  130  can be secured within the recess  128  in any suitable manner depending upon the particular material utilized to form the sections  130 , such as frictionally securing, adhering, thermally or sonically welding or molding the section  130  within the recess  128 . 
         [0035]    Alternatively, one or both of the components  106  and  108  can be formed with apertures (not shown) that expose portions of the core  104 , or that enable projections (not shown) from the core  104  to extend outwardly through the various components  106  and  108  to function as further decorative features for the handle  102 , or as improved gripping or other utilitarian features for the handle  102 , or both. 
         [0036]    Various other embodiments of the present invention are contemplated as being within the scope of the filed claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.