Abstract:
A compressor for a tire-repairing kit contains a second toothed wheel provided with a journal. The journal is functionally connected to a piston in such a way that the piston moves up and down when the second toothed wheel rotates. The inertial forces of the piston carrying out the up and down movement are compensated by a counterweight which is embodied in an integral manner with the second toothed wheel and is fixedly connected thereof.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuing application, under 35 U.S.C. § 120, of copending International application PCT/EP2006/004748, filed May 19, 2006, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German patent application DE 10 2005 029 523.1, filed Jun. 25, 2005; the prior applications are herewith incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to a compressor for a tire puncture kit, which contains the following elements: a drive motor which drives a first gearwheel, a second gearwheel which is mounted rotatably about a shaft and which is operatively connected to the first gearwheel, a stub which is arranged with a parallel offset to the shaft of the second gearwheel and which rotates about the shaft when the second gearwheel rotates, a piston with a piston rod which is connected to the stub in such a way that the piston moves up and down during a rotation of the second gearwheel, and a balancing weight which balances the inertia forces of the piston moving up and down. 
         [0003]    Such a compressor for a tire puncture kit is known, for example, from German utility model DE 200 01 815 U1. In the compressor known from this publication, the second gearwheel contains a central circular hole by which it is mounted rotatably on a hollow shaft which is fixedly connected to the housing of the drive motor. The balancing weight contains a shaft which is guided centrally through the hole in the second gearwheel and through the housing-secured hollow shaft and is mounted rotatably therein. The balancing weight further contains a stub which is connected to the piston rod of a piston in the aforementioned manner. The second gearwheel has a plurality of positioning pins by which the balancing weight is positioned in a defined position with respect to the second gearwheel. Therefore, the balancing weight is always in the correct position during an up and down movement of the piston, in order to be able to balance the inertia forces of the piston. 
         [0004]    The compressor known from the stated publication has a compact structure, since the second gearwheel and the balancing weight are disposed directly one behind the other in the longitudinal direction of the compressor. However, it should be pointed out that the compressor has a complex structure. Moreover, it has to be ensured that the second gearwheel and the balancing weight match one another exactly so that the balancing weight can be positioned without play between the positioning pins of the second gearwheel, since desirable noise might otherwise occur when actuating the compressor. Furthermore, any play between the second gearwheel and the balancing weight could result in the balancing weight not always balancing the inertia forces of the piston in an optimum manner. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    It is accordingly an object of the invention to provide a compressor for a tire repairing kit that overcomes the above-mentioned disadvantages of the prior art devices of this general type, which generates little noise and allows the inertia forces of the piston to be balanced in an optimum manner. 
         [0006]    With the foregoing and other objects in view there is provided, in accordance with the invention, a compressor for a tire puncture kit. The compressor contains a first gearwheel, a drive motor driving the first gearwheel, a shaft, a second gearwheel mounted rotatably about the shaft and operatively connected to the first gearwheel, and a stub disposed with a parallel offset to the shaft mounting the second gearwheel and rotates about the shaft when the second gearwheel rotates. A piston is provided and has a piston rod connected to the stub such that the piston moves up and down during a rotation of the second gearwheel. A balancing weight is provided for balancing inertia forces of the piston moving up and down, the balancing weight is connected nondetachably to the second gearwheel. 
         [0007]    Accordingly, the object of the invention is achieved in that the balancing weight is an element of the second gearwheel and is connected nondetachably thereto. The term “nondetachable connection” and the text below is to be understood as now described. The second gearwheel and the balancing weight can be manufactured, for example, as a single component in order to provide the nondetachable connection. However, the nondetachable connection can also be produced, for example, by adhesive bonding or welding, etc. 
         [0008]    One advantage of the invention can be seen in that there can be no play between the second gearwheel and the balancing weight, since the balancing weight is a fixed element of the second gearwheel. A further advantage of the invention can be seen in that the balancing weight is fixed securely in a defined position relative to the second gearwheel, with the result that the inertia forces of the piston moving up and down can be balanced in an optimum manner. A further advantage of the invention can be seen in that the compressor can be produced in a simple manner, since the second gearwheel and the balancing weight can be formed as a single component, and therefore the number of parts is reduced. 
         [0009]    In a development of the invention, the stub and the shaft for the second gearwheel are elements of the second gearwheel and are connected nondetachably thereto. The advantage of this development can be seen in that further components of the compressor are combined on the second gearwheel, with the result that the number of parts of the compressor is further reduced and the manufacture of the compressor is further simplified. This is particularly applicable if the second gearwheel is formed as a single component with the stated elements. 
         [0010]    In a further development of the invention, the second gearwheel has a cavity which is disposed annularly around the shaft. The advantage of this development can be seen in that the bearing which is used to mount the second gearwheel in the compressor can engage in the cavity, and therefore the overall length of the compressor is shortened. A further advantage of this development can be seen in that the second gearwheel is securely mounted. 
         [0011]    In another development of the invention, the bearing of the shaft, by which the second gearwheel is mounted, is embodied as a ball bearing or rolling bearing. The advantage of this development can be seen in that a ball bearing or a rolling bearing allows a bearing configuration with low friction losses. 
         [0012]    In an added development of the invention, the second shaft is embodied as a hollow shaft and connected to the bearing of the shaft in such a way that the second gearwheel is secured in the axial direction. The advantage of this development can be seen in that the axial securing for the second gearwheel can be accommodated in a space-saving manner in the hollow shaft. 
         [0013]    In an additional development of the invention, the shaft is connected to the bearing with the aid of a screw, which is inserted into the hollow shaft, or by flanging the hollow shaft. The advantage of using a screw can be seen in that the screw can be released simply (for example for exchanging the gearwheel). The advantage of flanging can be seen in that no separate component is required for producing the connection. 
         [0014]    In another further development of the invention, the stub is embodied as a hollow stub to which the piston rod is connected in such a way that the piston rod is secured in the axial direction. 
         [0015]    In another added development of the invention, the connection is produced with the aid of a screw, which is inserted into the stub, or by flanging the stub. 
         [0016]    In another further development of the invention, the second gearwheel is embodied as a cup with an outer cup and an inner cup. The balancing weight is disposed in the outer cup, the shaft is fastened concentrically on the end wall of the inner cup, and the stub is disposed on the end wall of the cup. The advantage of this development can be seen in that the second gearwheel has a compact structure, but nevertheless the balancing weight, the shaft and the stub can be incorporated in the second gearwheel in a space-saving manner. 
         [0017]    In a concomitant development of the invention, the second gearwheel is produced by a casting method. The advantage of this development can be seen in that the second gearwheel can be mass-produced in a simple and cost-effective manner by the casting method. A further advantage of this development can be seen in that the second gearwheel can be formed simply as a single component by the casting method. A castable lightweight metal (for example aluminum) is preferably used to produce the second gearwheel. 
         [0018]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0019]    Although the invention is illustrated and described herein as embodied in a compressor for a tire repairing kit, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0020]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0021]      FIG. 1  is a schematic view of a compressor for a tire puncture kit according to the invention; 
           [0022]      FIG. 2A  is a diagrammatic, cross-sectional view of a second gear wheel; 
           [0023]      FIG. 2B  is a diagrammatic, left-side view of the second gear wheel; 
           [0024]      FIG. 2C  is a diagrammatic, right-side view of the second gearwheel; and 
           [0025]      FIG. 3  is a diagrammatic, sectional view of a detail shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown a compressor  2  for a tire puncture kit in a schematic representation. A drive motor  4  of the compressor  2  drives a first gearwheel  6  which engages with a second gearwheel  8 . The second gearwheel  8  has a shaft  10  which is embodied as a hollow shaft. The second gearwheel  8  additionally contains a stub  22  which is disposed with a parallel offset to the shaft  10  of the second gearwheel  8  and which rotates about the shaft  10  when the second gearwheel  8  is driven by the drive motor  4  and the first gearwheel  6  and rotates. A piston rod  24  of a piston  26  is connected to the stub  22  in such a way that the piston  26  moves up and down in a cylinder  28  of a housing-secured attachment part  12  during a rotation of the second gearwheel  8 . Just like the shaft  10 , the stub  22  is an element of the second gearwheel  8  and is connected nondetachably thereto. Furthermore, the stub  22  is embodied as a hollow stub such that the piston  26  can be secured against extraction in the axial direction by way of its piston rod  24 . In the exemplary embodiment shown, the piston is secured with the aid of a screw  18  which is screwed into the hollow stub  22 , a washer  20  which bears against the end face of the stub  22  and against the lower end of the piston rod  24  being situated between the screw head and hollow shaft  22 . Alternatively, the piston can also be secured by flanging that end of the hollow stub which faces away from the drive motor  4 . 
         [0027]    Apart from the aforementioned elements, the compressor  2  contains a balancing weight  30  (also see  FIG. 2A ) which is an integral element of the second gearwheel  8  and is connected nondetachably thereto. The balancing weight  30  is used to balance the inertia forces of the piston  26  moving up and down. In the exemplary embodiment shown in  FIG. 1 , the balancing weight  30  is accordingly situated at the lower end of the compressor, since the piston  26  is situated precisely at its top dead center. 
         [0028]      FIGS. 2A to 2C  show the second gearwheel  8  in various views. In  FIG. 2A , a cross section is shown through the second gearwheel  8 . The second gearwheel  8  contains a cup  32  which is divided into an outer cup  34  and an inner cup  36  which are disposed concentrically with respect to one another. The balancing weight  30 , which is an integral element of the second gearwheel  8  and is connected nondetachably thereto, is arranged in a part of the outer cup  34 . The hollow shaft  10  is disposed centrally on an end wall  38  of the inner cup  36  in such a way that annular cavity  16  is formed between the hollow shaft  10  and an outer wall  40  of the inner cup  36 . The stub  22  is connected to an end wall  42  of the cup  32  (specifically to that side of the cup  32  which faces away from the interior of the cup  32 ). The stub  22  is connected with a parallel offset to the shaft  10 . Teeth  44  of the second gearwheel  8 , which engage with teeth of the first gearwheel  6  (see  FIG. 1 ), are arranged on the outer edge of the cup  32 . The shaft  10 , the stub  22  and the balancing weight  30  are preferably connected nondetachably to the second gearwheel  8 . This can be achieved in a simple manner by producing the second gearwheel  8  with the stated elements by a casting method. 
         [0029]      FIG. 2B  shows a plan view of the cup as seen from the side featuring the shaft  10 .  FIG. 2B  reveals that the inner cup  36  of the cup  32  is divided into a plurality of segments  36 . 1  to  36 . 7 , with the balancing weight  30  being situated in the segment  36 . 7 . 
         [0030]      FIG. 2C  shows a plan view of the cup  32  from the side featuring the stub  22 . Since the end wall  42  covers the entire base area of the cup  32 , only the end wall  42 , the teeth  44  and the stub  22  can be seen in  FIG. 2C . 
         [0031]      FIG. 3  shows a detail of  FIG. 1  in an enlarged representation, this detail showing the bearing arrangement of the second gearwheel  8  by the shaft  10 , which is embodied as a hollow shaft, in the attachment part  12 , which is connected fixedly to the housing of the drive motor  4  (see  FIG. 1 ). The attachment part  12  contains a cavity  46  which has a circular window  48  in its end wall. Bearings  14   a ,  14   b  in the form of ball bearings or rolling bearings are introduced into the cavity  46 . The shaft  10  is pushed through the window  48  from the right-hand side such that the bearings  14   a ,  14   b  are located between the shaft  10  and the attachment part  12  in the cavity  46  of the attachment part  12  (or in the annular cavity  16  of the second gearwheel). The attachment part  12  contains the seat for the outer rings of the bearings  14   a ,  14   b  and supports them relative to one another. 
         [0032]    The shaft  10  is connected to the bearings  14   a ,  14   b  in such a way that the second gearwheel  8  cannot be extracted toward the right, i.e. is secured, in the axial direction. In the exemplary embodiment shown, the gearwheel is secured with the aid of a screw  18  which is screwed into the hollow shaft  10 . Between the head of the screw  18  and the shaft  10  is situated a washer  20  which produces the connection between the shaft  10  and the bearing  14   a  (see also  FIG. 3 ). Alternatively, the gearwheel can also be secured by flanging that end of the shaft  10  which faces the drive motor  4 , with the result that the flanged edge bears against the bearing  14   a . The inner bearing  14   b  is located between a sleeve  50  and a shoulder  52  of the second gearwheel  8  and is thus fixed in its position. The second gearwheel  8  is secured toward the left by the second gearwheel  8  being supported on the attachment part  12  via the bearings  14 .