Patent Publication Number: US-2009223064-A1

Title: Tool with exchangeable piece

Description:
BACKGROUND OF THE INVENTION 
     This invention pertains to the field of tools, such as tools designed to carry sharp blades for scraping or stripping surfaces. 
     Hand-held or manual scraping tools have long been used to remove materials such as paint, wall coverings and flooring material from walls, floors and other planar surfaces. Commercially available hand-held scraper devices generally have a handle portion and an attached clamp portion in which is clamped or otherwise held a metal blade. The majority of the current scraping tools are fashioned to be strictly manually operated, thus limiting their utility. 
     Other known tool systems that provide for use in a handle or in power tool rely on multi-component systems to attach the tool or tool holder to a handle and may need additional tools such as a screw driver to remove the tool from the handle portion. Multiple pieces of the tool or handle add to the complexity and cost to the manufacturing of the tool. Also tools adapted for use in a power tool, such as a power reciprocating saw tend to be a single piece, so when the cutting edge becomes dull or damaged, the tool must either be replaced or the cutting edge needs to be skillfully sharpened. A damaged edge or a poorly sharpened edge may result in gouging the surface being scraped, therefore it is important to maintain a sharp edge in good condition. 
     SUMMARY OF THE INVENTION 
     One aspect of this invention is a handle member that may be fashioned as a single piece that needs no other tools to attach the tool or tool clamp to the handle member providing an easy quick method for switching between uses. Since the handle member is a single piece, it is easy and cost effective to manufacture, and this also dispenses with the problems of multiple pieces to produce and then having to assemble to make the final product. This embodiment can use a plastic handle member with a tapered hole in one end where the tapered hole only retains tools using the elastic properties of the plastic handle against the externally tapered engaging portion of the tool to be held. 
     Another embodiment of the invention is a tool clamp that provides the ability to be used either as a hand tool by using with a handle member or with a power tool, such as a power reciprocating saw. An advantage of this embodiment is that no other tool is needed to remove the tool clamp from the handle member and the tool clamp member is immediately ready for use in a power tool. The tool clamp also provides for easy exchange of tools or blades that can be fitted into its clamp, for example, the use of replaceable blades, so that sharpening is not necessary when the cutting edge becomes dull or damaged. The tool clamp has an extension that is adapted for use with a handle member and a power reciprocating saw. The extension may be tapered to match a taper in the receiving hole of the handle member to make a rigid fit. 
     In other embodiments an extension can be added to the handle and the tool clamp member can simply be inserted into a matching shaped hole of the handle without the use of tools to provide a rigid fit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of the preferred embodiment of the invention utilizing a straight blade in the tool clamp. 
         FIG. 2  is a cutaway view of the handle member of  FIG. 1  showing the tapered slot and internal threads. 
         FIG. 3  is a top view of the assembled tool clamp of  FIG. 1  with a straight blade attached. 
         FIG. 4  is a side view of the assembled tool clamp of  FIG. 1  with a straight blade attached. 
         FIG. 5  is a detailed view of the clamping section of the tool clamp of  FIG. 4 . 
         FIG. 6  is a perspective view of the preferred embodiment of the assembled system of  FIG. 1  showing the attachment of an optional commercially available extension handle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The foregoing “Summary of the Invention,” as well as the following detailed description of preferred embodiments will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred, it being understood, however, that the invention is not limited to the specific arrangements and instrumentalities disclosed. 
     In the preferred embodiment as shown in  FIG. 6 , the tool clamp  40  is engaged with the handle member  11  through the slot  12  by inserting the flat extension  15  (shown in  FIGS. 3 and 4 ) of tool clamp  40  into slot  12 . A slot is shown in this preferred embodiment, but other shaped holes in the handle member to receive a matching shaped extension of the tool clamp could alternately be used. The straight blade  25 , having the blade edge  26  perpendicular to the longitudinal axis of handle  11  is held firmly between the clamp members  22  and  15 . An optional extension handle  50  is shown engaged to the handle member  11  at the end opposite to where the tool clamp  40  is engaged. Such extension handles may be telescoping to allow for variable length. Tool clamp  40  is preferable made of a strong durable material, more preferably of metal, and most preferably of steel. Tool handle member  11  is preferably made of a plastic material, but other materials could be used. 
     In this embodiment, the tool handle  11  is shown with  4  cavities  13  that have a depth about the same as slot  12 . These cavities allow less material to be used in making the handle as well as providing for faster cooling during the molding process. Using less material allows handle  11  to be lighter weight and produced cheaper than without such holes. Even though 4 round cavities are shown in the preferred embodiment, other arrangement of cavities could be utilized to produce a similar effect. The cavities are preferably arranged such that at least one section of handle material extends from near the center of the wide dimension of either side of slot  12  to the outside of handle  11  to provide strength to support the tool while being used. Another arrangement of cavities between the slot and the outside of the handle could incorporate honeycomb shaped cavities. The cavities  13  are shown open to the outside of handle  11  as in  FIG. 1 , but these cavities could alternatively be completely enclosed and invisible, yet still reduce weight and cost, while maintaining adequate strength. 
       FIG. 3  shows the tool clamp of the preferred embodiment in more detail. The straight blade  25  is placed between clamp members  15  and  22  and rests against raised stops  19 . The clamp members  15  and  22  are held together with the blade  25  in between by screws  30  extending through holes  18  of clamp member  15  to engage threaded holes  23  of the clamp member  23 . The screws  30  are tightened until the clamp member  22  firmly rests on straight blade  25  and raised stops  19 . Raised stops  19  are slightly less raised than raised stops  20 . The tool clamp  40  is displayed with the flat extension adapted with taper  16  and the further adapted to be engaged with a reciprocating saw through end  17 . Further shown in  FIGS. 4 and 5 , clamp member  22  is resting on blade  25  and raised stops  20  firmly clamped down by screws  30  extending through clamp member  15  and engaging the threaded holes  23  of clamp member  22 . 
     The clamping method described here, while it is preferred, is but one of any number of ways that a tool, in this case, a straight blade, can be clamped into the tool clamp. Those practitioners in the art will recognize other methods of clamping a tool could be utilized without departing from the invention. 
     The tool clamp  40  is releasably engaged with the handle member  11  as displayed in  FIGS. 1 and 2  by inserting the tapered flat extension  16  of tool clamp  40  in slot  12  of the handle member until the tapered extension  16  rests firmly against matching taper  14  of slot  12  of the handle. The taper  14  in  FIG. 2  of handle  11  is preferably made of an elastic material, such as plastic, that is able to flexibly distort with the contact with the tapered flat extension  16  producing a force that holds the tool clamp  40  in place in handle member  11 .  FIG. 1  also displays the preferred orientation of the straight blade  20  with tool clamp members  15  and  22 .  FIGS. 1 and 2  also show the use of the optional commercial extension handle  50  engaging the internal threads  13  of the handle member  11 . Using internal threads is utilized in the preferred embodiment to engage the option handle extension  50 , but other methods to engage the handle extension  50  with the handle member  11  could be used as well.