Abstract:
A tool handle having a central gripping portion joined with a pair of opposed fastening portions. The gripping portion has an internal shell with an overcoating. The overcoating is two-part having first and second external sections having at least one different characteristic. The first overcoating section is applied in a first mold and thereafter the resulting structure is placed in a second mold wherein molding material is flowed through a channel in the interior of said shell from an underside of the handle to an exterior surface of the shell. The first and second sections cooperate to produce a continuous overcoating having sections with different characteristics that are free from molding blemishes.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    The present application is a divisional application of U.S. Ser. No. 09/717,194 filed Nov. 21, 2000, now U.S. Pat. No. ______ 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This application is directed to a tool handle having an inner shell with a molded overlay wherein the overlay includes at least two side by side sections having different characteristics and a method of manufacture thereof such that the sections blend together smoothly and do not include molding gate marks.  
           [0003]    Construction workers require tools that are durable and will withstand significant daily use over long periods of time. Preferably, such tools are also comfortable in the hand of the user and provide the user with a good grip. Handles are, therefore, often constructed with an inner shell that provides form and shape to the handle and then soft pliable overlay that provides a comfortable surface to the user.  
           [0004]    Such handles also represent a substantial amount of weight in many tools such as trowels and floats. Consequently, it is desirable to reduce the weight as much as possible. For this reason, portions of such handle where the handle attaches to a tool may be hollow, whereas the portion of the handle that is to be grasped by the user may include more internal structure or be solid in order to prevent collapse due to pressure exerted by the craftsman during use.  
           [0005]    Because such handles must be designed to comfortably fit the grip of the user, provide structure to attach to a tool, have certain portions that are hollow to reduce weight and for other reasons, the overall handle is typically a complex geometric structure which can present problems in molding, but the outer surface can be molded by most modern molding techniques when just a uniform over-mold or cover is applied to a shell.  
           [0006]    However, it is sometimes also desirable to have an over-mold that has sections with different characteristics. For example, it may be desirable to have sections or inlays with different degrees of softness or resiliency to the remainder of the overlay so as to improve the gripping characteristics in certain areas or, more commonly, it may be desirable to have sections with significantly different colors for purposes of either design or providing information to the user.  
           [0007]    In some instances it is possible to provide a base over-mold and then apply very superficially or just on the surface of the over-mold very thin layers of material that incorporates the second characteristic. In commercial hand tools, this does not work very well, since the tools are used for a long time and the superficial regions wear away fairly rapidly. Consequently, it is preferably that the two different characteristics be provided by sections of the over-mold that have approximately the same depth and, therefore, are likely to not wear out at different times. It is possible to apply to a shell a first overlay that covers a portion of the shell and has a first characteristic and then apply a second overlay that has the second characteristic by using a separate second exterior mold to produce letters, geometric designs or the like. However, when conventional molding techniques are used to apply inlays or the second section in and about the first section of the overlay, blemishes are created due to normal gating and parting lines that are highly undesirable. That is, at the end of the molding process, the molding material that is supplied to those sections through the mold must be somehow separated from the channels in the mold that are supplying the material. When the channels supply the molding material from the exterior of the exterior of the device gate marks and parting lines occur. Therefore, it is desirable to provide a molding method or technique that produces a final handle that includes an outer grippable portion that has an overlay that is comfortable to the user and that has separate external sections of an overlay that have different characteristics such as color and which are substantially free from blemishes that would be caused by molding the second portions of the outer mold by use of conventional molding techniques.  
         SUMMARY OF THE INVENTION  
         [0008]    A handle for use in conjunction with commercial tools and the like includes a central carrier or shell for providing shape and strength to the handle. The shell has an exterior surface and a series of internal ribs in a gripping portion of the handle. The shell also includes at least one attachment portion for joining the shell to the tool.  
           [0009]    The shell is initially placed in a first mold wherein a first over-mold is placed on the shell. The shell includes at least one internal channel running therethrough that communicates with the surface. The first mold allows for injection of a soft molding material onto the surface of the shell except in certain regions that are blocked by the mold. The blocked regions communicate with the internal channel shell and the mold is designed to cooperatively blocked flow of material through the channel and flow into the block regions during the first molding procedure.  
           [0010]    After removal of the shell from the first mold, it has a first section of an over-mold thereon that covers a substantial portion of the surface and has adjacent regions that include no over-mold and which are joined to the shell channel. The channel also joins with an underside of the handle grip portion.  
           [0011]    The handle with the first over-mold thereon is then placed in a second mold. The second mold allows for flow of a second molding material into the regions that were blocked by the first mold. The second material flows from the underside of the handle, through the channel and into the second over-mold open regions to produce second over-mold sections having different characteristics than the first over-mold sections. Often the second over-mold sections are inlays of the first over-mold section or completely surrounded by the first over-mold section. Subsequently, the second mold is removed. The first over-mold and the second over-mold are adjacent to one another and form a smooth transition therebetween without blemishes caused by gating or parting lines except on the underside of the handle where such blemishes are not visible.  
           [0012]    The fastening section or sections preferably are hollow and have cavities so as to reduce weight of the handle. In order to seal about the cavities of the fastening sections, the over-mold is extended slightly beyond the shell whereat the handle abuts with the tool. In this manner, as the tool is secured to the handle by a fastener, pressure exerted compresses the over-mold extension and produces a seal between the tool and the hollow cavity of the fastening section. Likewise, where a fastener such as a bolt, rivet or the like is utilized for securing the handle to a tool, a receptacle is provided for the fastener and an upper bead is provided about the receptacle that is compressed by the fastener and produces a sealing therebetween. This allows the cavity to remain watertight when the tool is used in liquids or cleaned.  
         OBJECTS AND ADVANTAGES OF THE INVENTION  
         [0013]    Therefore, the objects of the present invention are: to provide a handle for use in conjunction with tools, especially commercial tools, that is comfortable, resilient and easy to grip by the user while providing a strong internal structure; to provide such a handle having a molded overlay that has at least two adjacent sections having different characteristics such as different colors; to provide such a handle constructed from a shell having at least one interior channel that allows flow of moldable material through the interior of the handle to a second overlay region or section subsequent to the application of a first overlay region or section on the surface of the handle; to provide such a handle including at least one gripping portion and one fastening portion adjacent to the gripping portion and wherein the fastening portion is hollow for reduction of weight; to provide such a handle wherein the fastening portion includes an extension of the over-mold beyond the shell in the region whereat the fastening section mates with the remainder of a tool to which it is to be secured, so that the extension compresses during joining of the handle to the remainder of the tool to seal an internal cavity against seepage or water; to provide a method of producing such a handle wherein a shell is provided and placed in a first mold and a first molding material to produce a first over-mold is applied to the shell in the first mold that covers a substantial portion of the exterior of the shell, thereafter the shell with the first over-mold thereon is placed in a second mold and a second molding material to produce a second over-mold or inlay and is placed on the shell into second molding regions in a second molding process, so as to cover regions of the shell exterior not covered by the first over-mold; to provide such a molding process wherein a channel is provided within the interior of the shell and the first mold blocks both the channel and the second molding regions from application of the first molding material during the first molding process; to provide such a molding process wherein the second molding material is applied through the channel to the second molding regions from an underside of the handle to prevent parting lines and gating blemishes on the visible surface of the gripping portion of the handle; to provide such a molding process that allows for application of the first molding material and the second molding material in adjacent regions with a smooth transition therebetween and, preferably, with a substantially uniform thickness therebetween so as to provide a clean, long lasting combined over-mold; to provide such a method that allows for application of separate regions to the surface of the handle that are of substantially different characteristics, such as hardness or color; and to provide such a handle which is comparatively inexpensive to produce, very usable in service and especially well adapted for the intended usage thereof.  
           [0014]    Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.  
           [0015]    The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a top plan view of a shell used in construction of a tool handle in accordance with the present invention.  
         [0017]    [0017]FIG. 2 is a side elevational view of the shell.  
         [0018]    [0018]FIG. 3 is a bottom plan view of the shell.  
         [0019]    [0019]FIG. 4 is an enlarged cross-sectional view of the shell, taken along line  4 - 4  of FIG. 1, shown with a first mold placed thereabout.  
         [0020]    [0020]FIG. 5 is a top plan view of a pre-handle subsequent to a first mold procedure with a first over-mold section on the shell and after removal from the mold shown in FIG. 4.  
         [0021]    [0021]FIG. 6 is a side elevational view of the pre-handle shown in FIG. 5.  
         [0022]    [0022]FIG. 7 is a bottom plan view of the pre-handle shown in FIG. 5.  
         [0023]    [0023]FIG. 8 is an enlarged and cross-sectional view of the pre-handle shown in FIG. 5, taken along line  8 - 8  of FIG. 6, and also shown in conjunction with a second mold placed thereabout.  
         [0024]    [0024]FIG. 9 is a top plan view of the completed handle subsequent to removal from the mold shown in FIG. 8.  
         [0025]    [0025]FIG. 10 is a side elevational view of the completed handle.  
         [0026]    [0026]FIG. 11 is a bottom plan view of the completed handle.  
         [0027]    [0027]FIG. 12 is an enlarged, fragmentary and cross-sectional view of the completed handle, taken along line  12 - 12  of FIG. 11.  
         [0028]    [0028]FIG. 13 is an enlarged, fragmentary and cross-sectional view of the shell, taken along line  13 - 13  of FIG. 1, and showing a bolt positioned therein in phantom.  
         [0029]    [0029]FIG. 14 is an enlarged, fragmentary and cross-sectional view of the completed handle, taken along line  13 - 13  of FIG. 1.  
         [0030]    [0030]FIG. 15 is an enlarged, fragmentary and cross-sectional view of the completed handle, taken along line  15 - 15  of FIG. 14. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.  
         [0032]    The reference numeral  1  generally represents a tool handle in accordance with the present invention. The tool handle  1  is joined with a blade  4  or the like to produce a complete tool  5  such as is shown in FIG. 15.  
         [0033]    The handle  1  has a center gripping section or portion  10  and opposed fastening sections or portions  11  and  12  integrally joined to the center gripping portion  10 . The completed handle is shown in FIGS. 9, 10,  11 ,  12 ,  14  and  15 .  
         [0034]    The handle  1  is constructed in a process that is described in greater detail below by beginning with a shell  15  which is illustrated in FIGS. 1 through 3. The shell  15  has an outer frame  18  that is generally C-shaped in cross-section and which includes side panels  20  and  21  and a top panel  23 . The side panels  20  and  21  are integrally joined to the top panel  23  and have a common exterior surface  25 . Extending longitudinally through the gripping portion  10  of the handle  1  and from top to bottom, as seen in FIG. 2, are a plurality of ribs  28 . In the present embodiment there are four ribs  28  in addition to the side panels  20  and  21  which parallel the ribs  28 . The side panels  20  and  21  and the ribs  28  are approximately equally spaced from one another and define flow channels  31  to  35  therebetween.  
         [0035]    The two outermost channels  31  and  35  communicate with the exterior surface  25  on the top panel  23  through a plurality of ports  38 . The outer channels  31  and  35  also communicate with the exterior surface  25  on the side panels  20  and  21  through a plurality of ports  40 .  
         [0036]    The central channel  33  communicates with the exterior surface  25  on the top panel  23  through a plurality of ports  42  and the intermediate channels  32  and  34  also communicate with the exterior surface  25  on the top panel  23  through a plurality of ports  43 . The center gripping portion  10  is separated from the fastening portion  11  and  12  by curved walls  46  and  47  that extend from near the top to near the bottom of the handle  1  and operably prevent passage of fluid between the center portion  10  and fastening portions  11  and  12 .  
         [0037]    The fastening portions  11  and  12  each include a hollow cavity  49  and  50  respectively which are defined by the walls  46  and  47  in conjunction with the shell  15  with the exception of having a mold withdrawal opening  51  on the underside thereof and a fastener opening  52  on an upper side thereof. Each of the fastening sections  11  and  12  have a pair of longitudinal ribs  55  and  56  and a cross rib  57  that provide strength to the structure and a fastener receiving structure  58  that is operably positioned beneath the fastener opening  52  in the shell  15 .  
         [0038]    The fastener receiving structure includes an upper cylindrical wall  60  joined to a lower cylindrical wall  61  of smaller diameter at a shoulder  62 . The receiving structure  58  is sized and shaped to receive a fastener, such as a rivet on the illustrated bolt  64 , for securing the handle  1  to the blade  4 . The bolt  64  includes a head  65  and a threaded shank  66 . The upper cylindrical wall  60  has a large enough diameter to receive the bolt head  65  and a lower cylindrical wall  61  is sized and shaped to snugly receive the threaded shank  66 . Extending in a circle around the shoulder  62  and inward from the lower cylindrical wall  61  is a V-shaped bead  68  that is compressed as the bolt  64  is tightened so as to seal thereabout. The handle  1  has a molded covering  70  that extends over the entire outer exterior surface  25  of the shell  15  except in the location of the lower openings  51  and fastener openings  52 . The covering  70  is two part, having a first part or section  72  that covers a substantial portion of the shell  15  and a second part or section  73  which has non-integral portions and which mates with and adjoins the section  72  which in many cases entirely surrounds portions of the section  73  so as to produce an inlay. In particular, the section  73  has upper chevron-shaped portions  75  that are spaced and form a pattern or artistic design on the top panel  23 . The section  73  also has portions  76  located on the side panels  20  and  21  which in the present embodiment are in the shape of lettering.  
         [0039]    The sections  72  and  73  are constructed of first and second outer mold materials and are of approximately the same thickness on the shell  15  so as to form smooth transitions therebetween. In the present embodiment the first and second mold materials are similar in many ways having a preferred durometer in a range of from 60 to 70 and being relatively soft and pliable with a thickness of about 80 to 110 thousands of an inch over the entire shell  15 . In some embodiments the durometer could vary outside the above noted range when it is desirable to have two different durometers. In the present embodiment the first and second mold materials are of substantially different color so as to provide a contrast between the sections  73  and  72 . In particular, the section  73  portion second portion  76  includes writing that visually stands out in comparison to the section  72  and the section  73  portion  75  includes a design which visually stands out in comparison to the section  72 . While in the present embodiment the difference between the first and second mold materials after curing has been described as being with respect to color, it is foreseen that in some embodiments other characteristics could be modified such as relative hardness or the like to improve grip or abrasion in certain areas and for other purposes. The mold materials may vary with different plastics, but are preferably polyurethanes or polypropylenes.  
         [0040]    In the molding process the first mold material also fills the channels  32 ,  33  and  34  between the interior ribs  28 . The second mold material fills the outer channels  31  and  35  that are located between the side panels  20  and  21  and the ribs  28  respectively. A circumferential ring  79  of molding material extends slightly below the shell  15  about the opening  51 , as is seen in FIG. 13. When the handle  1  is joined to the remainder of the tool  5 , the ring  79  is compressed to produce a watertight seal therebetween, as seen in FIG. 15. The seal thus formed in conjunction with the seal formed by the bead  68  in conjunction with the bolt  64  renders the cavities  49  and  50  watertight.  
         [0041]    A pair of molds  85  and  86  are utilized in conjunction with the shell  15  to produce a final and completed handle  1 . The molds  85  and  86  are shown in a somewhat simplified and schematic matter in order to illustrate the process for producing the handle  1 , as molds and molding apparatus of this type are well known in the industry.  
         [0042]    The mold  85  has an upper element  89  and a lower element  90 . The upper element  89  is generally spaced from the shell exterior surface  85  the thickness of the intended covering  70  and, in particular, the section  72 . Portions  92  of the upper element  89  occlude the regions to be covered by the sections  73 . A pair of mold core slides  93  are operably positioned inwardly and abut against the shell  15  during the molding process so as to occlude the ports  40 .  
         [0043]    The lower element  90  is also preferably mostly spaced from the shell ribs  28  the expected width of the covering  70  except in the regions of the exterior channels  31  and  37  wherein the lower element  90  has a pair of plugs  95  that abut against the channels  31  and  36  so as to preclude flow of the first molding material thereinto. The mold  85  has an internal manifold  96  that has openings  96  and  97 . The openings  96  communicate with the lower end of the exterior surface of the side panels  20  and  21 , whereas the openings  98  abut an underside  82  of the shell  15  and flow communicate with the interior channels  32 ,  33  and  34 . In this manner as the first molding material flows through the manifold  96 , the first molding material enters the channels  31 ,  32  and  33  and the space between the exterior surface  25  and the mold  85  and eventually cures in the channels  31 ,  32  and  33  as well as in the over-mold or cover section  72 . The ports  42  and  43  allow flow of the first molding material between the exterior surface  25  and the channels  32 ,  33  and  34 . Once the first molding material has entered and completely filled the channels  32 ,  33  and  34  as well as the first section  72  located between the exterior surface  25  and the mold  85 , and has cured sufficiently, the mold  85  is removed.  
         [0044]    Thereafter, a product  100  of the first mold  85  is inserted into the second mold  86 , as is illustrated in FIG. 8. The second mold includes an upper element  101  and a lower element  102 . The upper element snugly fits about the first mold product  100  except in the regions associated with the second sections  73  where open space for the sections  73  is provided. The second mold lower element  102  has a flow manifold  104  that has openings  105  that are aligned with the channels  31  and  35 . In this manner, as a second molding material is flowed through the manifold  104 , it enters the channels  31  and  35  and flows through the interior of the shell  15  to the locations of section  73  and, in particular, to portions  75  and  76  thereof. The second molding material fills and remains in the channels  31  and  33 , as well as the over-mold section  73  subsequent to curing. The molding material in the channels  31  to  35  cooperates with the shell  15  to produce a strong yet pliable structure to allow firm gripping of the handle  1 . In particular, the molding material flows from the channel  31  and  35  through the ports  40  into the section portions  76  and through the ports  38  to the second section portions  75 . Once the second molding material has cured sufficiently, the second mold  86  is removed and the handle  1  is complete. A cross-section of the handle  1  subsequent to the second molding operation is seen in FIG. 12 with the shell  15  cross-sectioned with diagonals to the right, the first mold material  108  cross-sectioned with diagonals to the left and the second mold material  109  being cross-sectioned with cross-hatching. As can be seen in FIG. 12, the entire center gripping portion  10  of the handle  1  is filled with either the shell  15  or the first molding material  108  or the second molding material  109 .  
         [0045]    In accordance with the present invention, a first molded section  72  is placed upon a supporting shell  15 . Subsequently, a second molding section  73  is placed upon the shell as an inlay or in interspaced locations between the section  72  by flowing the material of the second molding material through an interior of the shell  15 . This allows the second molding material in section  73  to be completely surrounded by the first molding material in section  72  and both to be fully exposed to the exterior once the handle  1  is removed from the second mold  86 . This also allows the second molding material of the section  73  to be placed on the shell  15  without creating blemishes due to gate marks or parting lines that would be produced if the second molding material flowed directly from the mold  86  into the section  73 .  
         [0046]    It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.