Patent Publication Number: US-2016225495-A1

Title: Insulation System for a Tool and Tool having Same

Description:
The present invention relates to an insulation system for a tool and a tool equipped with said insulation system. 
     In the automotive industry, tools such as screwdrivers are used when installing batteries in electric vehicles. The batteries are generally accumulators that consist of a plurality of elements which have to be screwed to one another. Here, the screws also have to be screwed in on live parts. During this process, the protection of an operator of the tool against electrical voltages must be ensured, these voltages posing a danger to the operator. 
     This is currently implemented by way of example by an insulation tape winding of the tool. However, this is very complex and susceptible to faults. In addition, only the contact of live parts can be avoided hereby. At the least, however, an introduction of the electrical voltages from the workpiece to be worked on into the tool cannot be prevented. 
     The object of the present invention is therefore to provide an insulation system for a tool and a tool equipped with said insulation system, by means of which the aforementioned problems can be solved. In particular, an insulation system for a tool and a tool equipped with said insulation system are to be provided, with which both the tool and also the operator thereof are protected against electrical voltages occurring at a workpiece to be worked on with the tool. 
     This problem is solved by an insulation system for a tool as claimed in claim  1 . 
     Advantageous further embodiments of the insulation system are specified in the dependent claims. 
     The insulation system for a tool offers a convincing overall concept which ensures that both the tool and operator thereof are protected against electrical voltages occurring at a workpiece to be worked on with the tool. An overall solution for example of a screw system for category A screw connections is thus provided which makes it possible to work under “live working” conditions. 
     The insulation system can be easily retrofitted and can thus be used with any standard screwdriver. This is also advantageous for a user of the tool in respect of spare parts management. 
     The insulation system offers a simple and manageable solution to the aforementioned problem. The insulation system contributes to a high process safety of the tool. 
     The object is additionally solved by a tool as claimed in claim  7 . 
     Advantageous further embodiments of the tool are specified in the dependent claims. 
     The tool attains the same advantages as discussed previously in relation to the insulation system. 
     Further possible implementations of the invention also include combinations not explicitly mentioned of features or embodiments described above or hereinafter with regard to the exemplary embodiment. Here, a person skilled in the art will also add individual details as improvements or supplementations to the respective basic form of the invention. 
    
    
     
       The invention will be described in greater detail hereinafter with reference to the accompanying drawing and on the basis of an exemplary embodiment. In the drawing: 
         FIG. 1  shows a side view of a tool having an insulation system in accordance with an exemplary embodiment; and 
         FIG. 2  shows a sectional view of a tool according to the exemplary embodiment. 
     
    
    
     In the figures, like or functionally similar elements are provided with the same reference signs, unless otherwise specified. 
       FIG. 1  shows a tool  1  having an insulation system  2 . The tool  1  may be a screwdriver, a riveting tool, a punching tool, a nail gun, etc. The tool  1  in  FIG. 1  is a tool that can be hand-held. However, the tool  1  is not limited hereto. The tool  1  may also be a stationary tool. 
     In  FIG. 1  the tool  1  has a handle  11 , an on/off switch  12 , a battery compartment  13 , a housing  14 , and a drive unit  15 . A battery, such as a rechargeable accumulator or a non-rechargeable battery, can be received in the battery compartment  13 . The tool  1  is thus a cordless tool. The housing  13  is fabricated from a material, for example plastic, etc., that is electrically insulating. The tool  1 , in the region of the housing  13 , thus has a surface made of an electrically insulating material. However, the tool  1  has, at the drive unit  15 , a metal housing, in particular a steel housing. The drive unit  15  thus has an electrically conductive housing. 
     The insulation system  2  in  FIG. 1  has a first element and as second element  22  two housing parts  22 A,  22 B made of an electrically insulating material, such as plastic, etc. In particular, the two housing parts  22 A,  22 B are two insulating half-shells, which surround the metal housing of the angle drive, more specifically the drive unit  15 , as shown in  FIG. 1 . The two housing parts  22 A,  22 B are connected to one another by fastening elements attached in a recessed manner, for example screws, etc. 
     The first element  21  is fastened to the drive unit  15  in  FIG. 1 . In particular, an electrically insulated and electrically insulating extension can be received on a square of the drive unit  15  as first element  21  with integrated hexagonal socket wrench and in particular can be latched in position. The first element  21  is illustrated in greater detail in  FIG. 2 . 
     As shown in  FIG. 2 , a drive flange  211  is fitted on the output square of the drive unit  15  of the tool  1  and held by the detent pin  16  thereof. An insulation piece  212  is arranged in the drive flange  211  and sits in place for example with the aid of an interlocking toothing (not illustrated). As a result of this insulation piece  212 , the working point at a workpiece is electrically separated from the tool  1 . Axial securing is provided via a first fastening element  213 , for example in the form of a screw. 
     On the output side, the insulation piece  212  in  FIG. 2  is received in the output flange  214 , again by means of an interlocking toothing. Axial securing is provided here by a second fastening element  215  in the form of a roll pin. A commercial hex key as tool element  30  can now be fitted onto the output square of the output flange  214 . The output square of the output flange  214  can thus also be referred to as a receiving element for releasably receiving the tool element  30 . 
     The outer insulation of the first element  21  is provided by the components  216 ,  217  and  218  made of an electrically insulating material, such as plastic, etc. The components  216 ,  217  and  218  comprise an insulating sleeve  216 , a retaining ring  217  and a screw sleeve  218 . 
     The desired additional electrical insulation of the tool  1  with respect to electrical voltages at a workpiece to be worked with the tool  1  can thus be provided by the insulation system  2 . 
     In accordance with a second exemplary embodiment, the covering of the screwdriver socket, i.e. of the hex key  30 , can be adjusted by twisting the screw sleeve  218  to a greater or lesser extent and can be secured by means of the retaining ring  217 . The operator of the tool  1  thus has the option to himself set a maximum possible covering with the necessary accessibility to the screwing location. 
     Otherwise, the tool  1  and insulation system  2  thereof are constructed in the present exemplary embodiment in a manner identical to that described with reference to the first exemplary embodiment. 
     In accordance with a third exemplary embodiment the components  216 ,  217  and  218  are not fixedly connected to the output shaft, which is formed from the components  211 ,  212 ,  214 ,  30 . This means that the components  216 ,  217  and  218  in the event of normal operation are frictionally coupled and rotate with the output shaft formed from the components  211 ,  212 ,  214 ,  30 . However, the components  216 ,  217  and  218  remain still when contacted. Consequently, the components  216 ,  217  and  218  are arranged freely rotatably. The components  216 ,  217  and  218  can therefore prevent injuries to the operator of the tool  1 , which may be caused for example if an item of the operator&#39;s clothing is reeled in at the tool  1  and/or insulation system  2  thereof. 
     Otherwise, the tool  1  and insulation system  2  thereof are constructed in the present exemplary embodiment in a manner identical to that described with reference to the first exemplary embodiment. 
     In accordance with a fourth exemplary embodiment the first element  21  is embodied such that the first element  21  cannot be removed from the second element  22  without disassembly. A design of this type prevents the simple, for example tool-free, modification of the insulated output by an operator of the tool  1 . The safety for the tool  1  and operator thereof can thus be further increased. 
     Otherwise, the tool  1  and insulation system  2  thereof are constructed in the present exemplary embodiment in a manner identical to that described with reference to the first exemplary embodiment. 
     All of the previously described embodiments of the tool  1  and of the insulation system  2  can be used individually or in all possible combinations. In particular, all features and/or functions of the previously described exemplary embodiments can be combined arbitrarily. In addition, the following modifications in particular are conceivable. 
     The parts illustrated in the figures are illustrated schematically and may deviate in the actual embodiment from the forms shown in the figures, provided the previously described functions thereof are ensured. 
     Where necessary the first fastening element  213  can also be embodied other than as a screw. The second fastening element  215 , where necessary, may also be embodied other than as a roll pin, and for example can be embodied by a screw. Fastenings in the form of welded connections, glued connections, a snap-fit connection, etc. are also possible for both fastening elements  213 ,  215 .