Abstract:
A three-in-one pneumatic tool combining interchangeable tool heads with a standard pneumatic rotary drive assembly. The system includes drill, die grinder, and ratchet tool heads that may be attached/detached as desired from a pneumatic drive assembly. A quick-release coupling mounted at the mating end of the pneumatic drive assembly allows the user to easily insert the corresponding mating end of the various tool heads into the pneumatic drive so they may then be used in the same manner as their more traditional versions.

Description:
RELATED APPLICATIONS 
       [0001]    There are no related applications. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
       [0003]    None. 
       FIELD OF THE INVENTION 
       [0004]    The present invention generally relates to a pneumatic tool with interchangeable tool heads. More specifically, this invention relates to a combination pneumatic tool wherein the functionality of multiple tools is duplicated using easily interchangeable tool heads that may be quickly exchanged as desired. No additional tools are required in order to perform the operation, the hand strength and dexterity possessed by the average adult is sufficient. 
       BACKGROUND OF THE INVENTION 
       [0005]    Compressed gasses, usually in the form of compressed air, have long been used to provide motive power for hand tools. At least as early as 1858, Burnell U.S. Pat. No. 21,318 disclosed a fluid-driven “rotary engine” that is usable, for example, as a “steam engine, a water-wheel or a meter.” While such fluid-driven devices continue to be common, ostensibly the most common “fluid” now used in such apparatuses is compressed air, or in some cases, compressed nitrogen. Typically, the compressed gas is injected into a chamber wherein it causes rotational movement of a rotor/impeller. Power produced at the axle of the rotor/impeller is then coupled to various rotating tools to perform, for example, cutting-, drilling-, or grinding-type operations. These pneumatically-powered tools can be used in essentially any role in which an electric motor may be used, with the advantage that they are often simpler and less expensive to manufacture, more durable, and lighter/smaller compared to their electrically powered counterparts. Nonetheless, pneumatic tools are expensive and their manufacture is labor intensive. Moreover, since the tools must be attached by a hose to their compressed air supply, utilizing multiple tools for a task typically entails an unnecessarily laborious process wherein the user must remove the hose from the tool he/she no longer needs and thereafter attach it to the now-required tool. Furthermore, the cost of acquiring specific tools for specific jobs is expensive and the acquisition of such tools requires significant storage space. 
         [0006]    What is needed therefore is a cost-effective method to quickly switch heads as they are needed using the basic air supply and coupling. Such a device presents cost and space economies and its costs of manufacturing and ownership would be lower compared to traditional tools. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is a three-in-one pneumatic tool uniquely combining interchangeable tool heads with a standard pneumatic rotary drive assembly. In a preferred embodiment, the system includes drill, die grinder, and ratchet tool heads that may be attached/detached as desired from a pneumatic drive assembly. A quick-release coupling mounted at a mating end of the pneumatic drive assembly allows the user to easily insert the corresponding mating end of the desired tool head into the pneumatic drive so that they may then be used in the same manner as their more traditional versions. The system not only saves time when multiple tools are needed to complete a particular task, the system also reduces the costs of both manufacturing the tools and their price to the consumer, with the additional benefit that because the incremental costs of additional tool heads will be lower compared to buying a traditional pneumatic tool, the consumer may be able to afford a wider array of tools than otherwise possible. Furthermore, when breakage occurs only one tool head need be replaced or repaired. Moreover, the tool heads can be upgraded as technological improvements are made, thereby ensuring that the system will never become obsolete. 
         [0008]    While in its preferred embodiment, this invention includes drill, die grinder, and ratchet tool heads, this apparatus contemplates use of any tool head utilizing rotational motion, for example, a cut-off tool, circular saw, circular sander, or impact wrench. Additionally, this invention encompasses tools wherein rotational motion may be converted into linear movement, for example, a reciprocating sander or impact hammer/drill/wrench. 
         [0009]    It is an object of the invention to provide a pneumatic tool with interchangeable tool heads; 
         [0010]    It is yet another object of this invention to provide an interchangeable tool head pneumatic tool wherein no tools are required in order to exchange tool heads; 
         [0011]    It is still another object of this invention to provide an interchangeable tool head pneumatic tool wherein typical human hand strength and dexterity are sufficient to exchange tool heads; 
         [0012]    It is an object of this invention to provide a pneumatic tool with easily interchangeable tool heads wherein tool heads incorporating new technologies can be accommodated; and, 
         [0013]    It is another object of this invention to provide a wide array of pneumatic tools to the consumer at a lower cost. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is an exploded perspective view of the invention showing the pneumatic drive assembly and the ratchet, die grinder, and drill tool heads of the preferred embodiment; 
           [0015]      FIG. 2  is a perspective detail view of the mating ends of the pneumatic drive assembly and the tool heads shown in  FIG. 1 ; 
           [0016]      FIG. 3  is an enlarged front view showing the pneumatic drive assembly mating end; 
           [0017]      FIG. 4  is a cutaway schematic showing the mating end of the pneumatic drive assembly with the mating end of a tool head inserted therein, prior to interlocking; 
           [0018]      FIG. 5  is a cutaway schematic showing the mating end of the pneumatic drive assembly with the mating end of a tool head inserted therein as shown in  FIG. 4 , with mating ends interlocked; and, 
           [0019]      FIG. 6  is an exploded perspective view of the mating end of the pneumatic drive assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The preferred embodiment and best mode of the invention are shown in  FIGS. 1 through 6 . While the invention is described in connection with certain preferred embodiments, it is not intended that the present invention be so limited. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0021]    This invention may be constructed from any sufficiently durable material including carbon steel, stainless steel, aluminum, zinc, other metals, various polymers, ceramics, and combinations thereof. 
         [0022]    Turning now to  FIG. 1 , the preferred tool embodiment  10  is shown, including its pneumatic drive assembly  11 , a ratchet tool head  12 , a die grinder tool head  13 , and a drill tool head  14 . The pneumatic drive mating end  20  and the tool head mating ends  40  of each of the tool heads are also shown and are disclosed in detail infra. Also shown is air hose  19  which is connected to a supply of compressed air (not shown) to thereby provide motive power for the apparatus  10 . The air hose  19  is mounted to the pneumatic drive assembly  11  in a conventional manner, typically via a threaded fitting of sufficiently compressible metal (e.g., brass) such that an air-tight seal is ensured. 
         [0023]    Turning to  FIG. 2 , the pneumatic drive mating end  20  and tool head mating end  40  are shown in detail. The pneumatic drive mating end  20  is mounted to the distal end  21  of the pneumatic drive assembly  11 . A locking ring  22  is mounted at the distal end of the pneumatic drive mating end  20  whereby locking and unlocking of the tool heads are effected. In the preferred embodiment, knurling is applied to the external surface of the locking ring  22  to increase the user&#39;s grip when manipulating the tool  10 . This invention contemplates any mechanism by which treatments may be applied to the surfaces of the implement  10  to increase friction in areas that will be manipulated by the user, including stipling, acid etching, and the similar. The pneumatic drive mating end  20  has a female end  24  defined by the interior surface  30  of the pneumatic drive mating end  20  sized to accommodate insertion of the corresponding tool head mating end  40 . The female end  24  is preferably hexagonal in cross section although any eccentric shape may be used to ensure that the external surfaces of the pneumatic drive assembly  11  and tool heads  12 ,  13 , or  14  do not rotate relative to one another when mated. Locking bearings  25  consisting of spherical, ball-bearing-like elements are provided adjacent the interior surface  30  of the female end  24 . The bearings  25  are held in apertures  26  formed in the interior surface  30  which are slightly smaller in diameter than the diameter of the bearings  25  such that when the bearings  25  are inserted from behind the interior surface, the bearings  25  protrude outward from the surface  30  of the female end  24  but are prevented from complete passage through apertures  26 . The locking bearings  25  are biased toward the interior of the female end  24  via a spring (not shown in  FIG. 2 ) discussed infra. The pneumatic drive assembly drive shaft  23  is shown at the center of the female end  24 . The drive shaft  23  is in communication with the rotor/impeller (not shown) of the pneumatic drive assembly, and its drive shaft male end  31  is accommodated by the corresponding female end  44  in the tool heads  12 ,  13 , or  14  when the device  10  is assembled for use. Like the female end  24  discussed above, the drive shaft male end  31  is hexagonal in cross section but any eccentric shape will suffice to ensure that the drive shaft male end  31  and the rotating elements of the respective tool heads  12 ,  13 , or  14  rotate in concert. 
         [0024]    The proximal end  41  of any of the tool heads  12 ,  13 , or  14  is also shown in  FIG. 2  with the tool head mating end  40  mounted proximally in relation thereto. The tool head mating end  40  further comprises the tool head shank  42  with male end  43  having exterior dimensions corresponding to the interior dimensions of the female end  24  of the pneumatic drive mating end  20 . A tool head drive shaft female end  44  is provided on the tool head mating end  40 , coaxially inside the tool head shank  42 , and is sized to accommodate the drive shaft male end  31  of the pneumatic drive mating end  20 . The drive shaft female end  44  is free to rotate and is in communication with the rotating elements of tool heads  12 ,  13 , or  14  (not shown). An arcuate locking channel  50  is formed in the tool head shank  42 , the channel  50  having a radius sized to hold the locking bearings  25  of the pneumatic drive mating end  20 . 
         [0025]      FIG. 3  shows the front end of the pneumatic drive mating end  20  with its locking bearings  25  in their locked position. In  FIGS. 4 and 5 , mating of the tool  10  is shown.  FIGS. 4 and 5  are cutaway schematics showing the mated pneumatic drive assembly  11  (more specifically, its pneumatic drive mating end  20 ) mated with a tool head  12 ,  13 , or  14  (more specifically, a tool head mating end  40 ).  FIG. 4  shows the apparatus just prior to locking and  FIG. 5  shows the same apparatus fully mated and ready for use. As shown in  FIG. 4 , the locking ring  22  is biased against a circumferential coil spring  52  held in position via first and second spring retaining lips  55 ,  56 . Withdrawing/retracting the lock ring  22  exposes an annular unlocking channel  53  formed on the interior surface of the locking ring. Thereafter, insertion of the tool head mating end  40  causes the locking bearings  25  to retract into the unlocking channel  53  such that they cannot impinge insertion of the respective tool head  12 ,  13 , or  14 . As shown in  FIG. 5 , once the tool head  12 ,  13 , or  14  is fully seated, the locking ring  22  is released and the coil spring  52  biases the locking ring  22  forward. A split ring  51 , as seen in perspective in  FIG. 6 , abuts the step formed in the locking ring to prevent further movement within locking ring  22 , at which point the unlocking channel  53  has been moved from alignment with the locking bearings  25  with the result that the bearings  25  are now forced into the locking channel  50  of the tool head mating end  40  thereby locking the mating end in place. 
         [0026]      FIG. 6  is an exploded view of various elements of the pneumatic drive mating end  20  showing the relative position of each element. Notable elements and assembly steps include its female end  24  showing the apertures  26  therein for accommodating the locking bearings  25 . As noted above, coil spring  52  is positioned over the female end  24  such that it encircles same and rests on the second spring retaining lip or step  56 . The locking ring  22  is subsequently positioned over this combination so that the other end of the coil spring  52  bears against the first spring retaining lip or step  55 , thus holding locking bearings  25  and coil spring  52  captive. A split ring  51  is then fastened about the annular split ring channel  54  formed in the exterior surface of the female end  24  in order to secure the apparatus. 
         [0027]    In use, the user simply retracts the locking ring  22  of the pneumatic drive mating end  20  proximally so that the locking bearings  25  are free to move. Insertion of the tool head mating end  40  causes the bearings  25  to retract into the unlocking channel  53 . Once seated, the locking ring  22  is released and pressure from the coil spring  52  causes it to return to its original position, simultaneously moving the unlocking channel  53  away from alignment with the locking bearings  25  and thus forcing the aforementioned bearings  25  back into their locked position. When a tool head  12 ,  13 , or  14  is seated, the locking channel  50  of the tool head mating end  40  is locked in place such that the male end  43  of the tool head shank  42  is accommodated within female end  24  of the pneumatic drive mating end  20  and the pneumatic drive assembly  11  and tool heads  12 ,  13 , or  14  are locked together and cannot rotate relative to one another. Similarly, the drive shaft male end  31  of the pneumatic drive assembly drive shaft  23  is accommodated within the tool head drive shaft female end  44  such that they are locked together and cannot rotate relative to one another. The apparatus  10  is now locked together and ready for use. One need only ensure that a supply of air is provided and the various cutting, polishing, drilling, grinding, etc. operations may be commenced. In operation, compressed gas enters the proximal end of the pneumatic drive assembly  11 , thereby causing rotation of the rotor/impeller therein. The impeller is in communication with the drive shaft  23  of the pneumatic drive assembly, which is now interlocked with the corresponding tool head drive shaft female end  44  of the selected tool head  12 ,  13 , or  14 , such that, in order, rotation of the impeller causes rotational motion of the drive shaft  23 , which in turn causes rotation of the tool head drive shaft female end  44 . The tool head drive shaft female end  44  is in communication with the operational elements of the tool, for example, its drill head, die grinder head, or ratchet head such that work may now be performed. 
         [0028]    The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments which have been described above. Instead, the embodiments described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the following claims: