Abstract:
An extension device for trigger-actuated hand tools includes a longitudinal member having a handle with an actuation mechanism at one end thereof and a tool engaging portion at the other end thereof. A linkage couples the actuation mechanism to the trigger of the hand tool. The tool engaging portion can be adapted to engage a variety of tools and preferably includes a threaded screw fastener to secure the extension device to the tool. In a preferred embodiment, the longitudinal member is a hollow tubular member and the linkage is a spring-biased, unitary rod extending through the interior bore of the hollow tubular member.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to an accessory for hand tools, such as pneumatic and electric tools, and more specifically to a extension piece with a trigger that provides user control of the tool at a specified distance from the tool itself.  
         BACKGROUND OF THE INVENTION  
         [0002]    There are a large variety of pneumatic and electric tools developed over the past 20 or more years that require the operator to remain in immediate proximity with the tool in order to operate the trigger, switch or other mechanism that actuates the tool. In many instances, this requires the operator to maintain awkward and/or uncomfortable body posture, such as on one&#39;s knees, for extended periods of time. Additionally, it is frequently desired to use such tools in a manner that does not allow the operator to maintain the customary hand contact that is required to effectively actuate the tool. For example, a nail gun that is used to install ceiling tiles would otherwise require a means of getting the operator closer to the ceiling (e.g., on a ladder, etc.) in order to actuate the gun and drive nails into the ceiling. While solutions to such problems of using pneumatic and electric tools do exist (such as rudimentary extension devices), there is currently the need to remedy various drawbacks associated with existing solutions.  
           [0003]    For example, some extension devices provide only an extension that grips the tools itself, and do not allow for remote actuation of the trigger or other mechanism that operates the tool. These devices possess the drawback that the operator must always stay within a specific proximity of the tool so that they may turn it on and off in the conventional manner.  
           [0004]    Another drawback of existing extension devices is that they are frequently heavy, bulky and otherwise too unwieldy for many desired applications. For example, most of such prior art devices require multiple hands to operate, even for use with tools that otherwise only require a single hand to operate normally. This presents the serious burden of inhibiting the other tasks that an operator would like to or must accomplish with his free hand, such as maintain difficult positioning, balance or performing tasks that facilitate the efficient completion of the job at hand.  
           [0005]    Still other drawbacks of existing extension devices is that they oftentimes do not afford the flexibility and/or simplicity that is required to provide an accessory product that makes sense to both the consumers and the producers. Such extension devices are usually of a fixed nature, and are inflexible in adapting to a discrete number of positions that are most advantageous to the various required uses. Similarly, such devices generally fail to possess the simplicity and compactness that is desired, thereby placing the operator at a significant disadvantage.  
           [0006]    Therefore, current extension devices are generally unable to offer the construction, usefulness, and flexibility required to adequately and cost-effectively provide the functionality desired by today&#39;s pneumatic and electric tool-using customers.  
         SUMMARY OF THE INVENTION  
         [0007]    An extension device for electric and pneumatic trigger-actuated hand tools comprising an extension piece, a handle having a tool actuation mechanism (trigger), a tool engaging portion, and linkage that translates a user action at the handle to the operating mechanism located on the tool itself is described. The tool-engaging portion is adapted to the particular tool that it is desired to operate, and may include, for example, a threaded screw fastener or a band structure to secure the tool therein. In one embodiment, the extension piece is comprised of a hollow tubular member, and the linkage comprises a unitary rod spring biased within the hollow tubular member and extending therethrough. In the presently preferred embodiment, the extension device may be set at multiple angles by means of discrete positioning means that allows a person to use the device with any tool for a large variety of applications.  
           [0008]    Other features and advantages of the present invention will be apparent from the accompanying drawings and from detailed description that follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 illustrates a person using a tool extension device, according to one embodiment of the present invention;  
         [0010]    [0010]FIG. 2 illustrates a close-up view of the left side of the tool extension device, shown attached to an exemplary tool, according to one embodiment of the present invention;  
         [0011]    [0011]FIG. 3 a  illustrates a close-up view of the right side of the tool extension device, according to an embodiment of the present invention where the tool engaging portion is hinged and in an open (tool receiving) position;  
         [0012]    [0012]FIG. 3 b  illustrates a close-up view of the right side of the tool extension device, according to an embodiment of the present invention where the tool engaging portion is hinged and in an closed (tool securing) position;  
         [0013]    [0013]FIG. 4 illustrates a cross-section of the tool extension device, showing a unitary linkage member with fixed trigger structure, according to one embodiment of the present invention; and  
         [0014]    [0014]FIG. 5 illustrates a cross-section of the tool extension device, showing a linkage member with moving trigger structure, according to one embodiment of the present invention; 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    An extension device for electric and pneumatic trigger-actuated hand tools comprising an extension piece, a handle having a tool actuation mechanism (trigger), a tool engaging portion, and linkage that translates a user action at the handle to the operating mechanism located on the tool itself is disclosed. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide an understanding of the present invention. It will be evident, however, to those of ordinary skill in the art that the present invention may be practiced without the specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate explanation. The description of preferred embodiments is not intended to limit the scope of the claims appended hereto.  
         [0016]    The typical operation of a contemplated tool extension device in shown in FIG. 1. FIG. 1 illustrates a person using a tool extension device that is constructed according to one preferred embodiment of the present invention. As seen in the figure, the tool operator or user  102  is shown holding an extension device  104  in one hand. The extension device  104  includes a first longitudinal extension member  105 , a handgrip portion  106  and actuation mechanism  108  (such as a trigger) at one end, and a tool engaging portion  110  at the other end. In this embodiment, the tool engaging portion  110  is comprised of a tool-receiving cavity and a threaded knob  114  that is used to secure the tool  116  onto the extension device  104 . The tool  116  shown in the embodiment of FIG. 1 is a pneumatic nail gun that is generally attached to a source of pressurized air by means of a hose  118 ; however, the invention disclosed herein is not limited to any particular tool or tools.  
         [0017]    As seen in more general detail in the embodiment of FIG. 1, the tool  116  has an switch  120  (which could be a button, a trigger, an on/off switch or any other type of salient mechanism), which is actuated by the relative movement of a lever  122  extending from the tool end of the extension device  104 . The lever  122  is connected to the actuation mechanism  108  by means of linkage (not shown in FIG. 1) that extends through the extension member  105 , according to this preferred embodiment. During use, user action upon the actuation mechanism  108  (e.g. pulling the trigger) is translated by means of a linkage structure to the lever  122  located at the tool-receiving end of the extension device  104 . As will be described in more detail below, the actuation mechanism  108 , the lever  122  and/or the linkage can be spring biased so as to return the lever  122  to a non-actuating (non-triggering) position after a user action, thereby resetting the tool and extension device positioning for subsequent and repetitive use.  
         [0018]    [0018]FIG. 2 illustrates a close-up view of a portion of the tool extension device  104 , shown attached to an exemplary tool  116 , according to one embodiment of the present invention. FIG. 2 shows greater detail of how the tool  116  may be secured to the extension device  104 , and how the lever  122  can engage and operate the tool switch  120 . With respect to the extension device  104 , the detail of FIG. 2 depicts only the tool-side portion of the extension member  105 , as well as the tool engaging portion  110 , the threaded knob  114 , an exposed portion of the linkage  202 , and the lever  122 . With respect to the illustrated tool, the detail of FIG. 2 depicts the tool body  204 , the tool handle  206 , the tool operating switch  120 , and the pressurized air hose  118 .  
         [0019]    As is evident from the illustration of FIG. 2, the tool  116  can be secured to the extension device  104  by inserting the handle  206  within a complimentary-shaped tool-receiving cavity  112  and screwing an inward facing, threaded end (not shown) of the threaded knob  114  against an upper side of the tool handle  206 . This screwing-in of the threaded knob  114  forces the tool handle against the lower (in this figure) bracket portion of the tool receiving cavity  112 , thereby securing the tool  116  to the extension device  104 .  
         [0020]    This tool-receiving cavity  112  and threaded knob  114  combination is one form of the securing device set forth in this specification, however many other securing devices are contemplated. For example, as described below in connection with FIG. 3 a , a preferred embodiment that is a modification of the above securing device incorporates a two-piece or hinged tool-receiving cavity. As shown in the figure, the tool engaging portion flips open and closed to accept and surround the tool handle, with a similar threaded knob on the hinged portion being used to secure the tool. Furthermore, the securing device might also take the form of a band having some type of a clip or a screw-together clasp that is used to tighten the band around the tool handle. Similarly, the securing device could take the form of cavity that snaps tightly closed or structure that is twisted in such a manner as to lock the handle tightly in place. In sum, the securing device can take the shape of many known mechanical coupling devices that provide a firm connection between the extension device  104  and the tool  116 . Depending upon the tool itself, the securing device can secure the tool by connection to some part of the subject tool, and is not limited to attachment to the tool handle alone.  
         [0021]    [0021]FIG. 3 a  illustrates a close-up view of the right side of the tool extension device, according to an alternate embodiment of the present invention where the tool engaging portion is hinged and in an open (tool receiving) position. The extension device  104  is shown in FIG. 3 a  such that the tool side of the extension member  104  and the exposed tool engaging portion  110  are readily seen, according to this preferred embodiment. The tool engaging portion  110  is composed of a first portion  302  that is fixed to the extension member  104 , a hinge  304 , a second portion  306  that is rotatably attached to the hinge  304 , and a threaded knob  308  having a plunger/coupling end portion  310 . Also shown in this view are the exposed part of the linkage portion  202 , and the lever  122 .  
         [0022]    [0022]FIG. 3 b  illustrates a close-up view of the right side of the tool extension device, according to this alternate embodiment of the present invention where the tool engaging portion is hinged and in an closed (tool securing) position. From this ‘closed’ arrangement, the backside of the second portion  304  discussed above in connection with FIG. 3 a  is the primary structure that can be seen of the tool engaging portion  110 . As can be seen from the Figure, the threaded knob  308  is now located on top (in this view) of the tool engaging portion  110 , as it has been rotated upward along with the second portion  304  via the hinge (not shown).  
         [0023]    [0023]FIG. 4 illustrates a cross-section of the tool extension device, showing a unitary linkage member with fixed trigger structure, according to one embodiment of the present invention. In this embodiment, the basic parts of the extension device  104  are shown in cross-section, including the handle portion  106 , the extension member  105 , the tool engaging portion  112 , and the threaded knob  114 . The interior of the extension member  105  depicts the preferred elements of a linkage portion that connects the actuation mechanism  108  with the lever  122 . In should be noted that, although this and other embodiments illustrate the linkage portion located on the interior of the extension member  105 , the present invention contemplates any location of the linkage elements with respect to the extension member  105 , such as external thereto, or a combination of external and internal components.  
         [0024]    The linkage portion illustrated in the embodiment of FIG. 4 is comprised of a unitary rod  402  and a spring biasing member  404 . The spring biasing member  404  can be any type of spring or biasing device that either exerts a pushing or pulling force on the unitary rod  402  so as to keep it in a “set” position allowing continuous and repetitive actuation of the tool. In this regard, the spring biasing member  404  can be attached to any part of the extension device  104  that provides such bias. This unitary linkage embodiment is characterized by a particularly simple construction that has both the actuation mechanism  108  and the lever  122  permanently affixed to either end of the unitary rod  402 . This unitary structure affords significant advantage, in terms of desirability, reliability and ease-of-construction, over known extension devices.  
         [0025]    [0025]FIG. 5 illustrates a cross-section of the tool extension device, showing a linkage member with a moving trigger structure, according to one embodiment of the present invention. This illustration shows most of the same elements of the extension device  104  from FIG. 4 without change, specifically, the handle portion  106 , the extension member  105 , the tool engaging portion  112  and the threaded knob  114 . However, the embodiment of FIG. 5 shows a linkage portion that is comprised of an actuation mechanism  108  situated at a set rotation point  410 , a lever  122  situated at a lever rotation point  416 , and moving linkage connecting the two rotation points. It is noted that this embodiment is shown for purposes of illustration and not limitation, as many known moving linkages are contemplated within the scope of the present invention.  
         [0026]    The contemplated moving linkage(s) can be implemented, as shown in FIG. 5, by means of a cable  412  and a cable sleeve  414 . In such embodiments, the cable  412  is connected to either the actuation mechanism  108  itself or to a gear mechanism (such as those found in conventional bicycle brake lines) such that operation of the actuation mechanism  108  causes the cable to be drawn in a direction either away from or into the fixed cable sleeve  414 . The relative motion on the cable is either translated directly through the cable sleeve, or indirectly by means of more complicated linkage, to the tool-receiving end of the extension device. At the tool receiving end, the cable  412  exits the cable sleeve  414  and provides relative motion to the lever  122  in order to operate the trigger of the pneumatic or electric tool. This relative motion is provided in the complimentary fashion as the relative motion that was delivered by the user&#39;s hand.  
         [0027]    In the foregoing, a device has been described for providing an extension of reach and actuation for hand tools, particularly pneumatic or electric tools. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense