The invention relates to a compressor for discharging a medium, in particular tire sealant that is to be discharged from a container into a tire, wherein a motor of the compressor drives a step-up transmission wheel for moving at least one piston in a compression chamber.

Prior art DE 10 2004 042 91 1 A1 discloses a device for conveying a gas from a pressure chamber, in particular for discharging a sealant from this container into a tire of a vehicle and for inflating the tire. A compressor can be attached to the sealant container disclosed in said document. This compressor can also be configured as a diaphragm compressor which compresses air present in the sealant container in order to force sealant out of the sealant container.

Moreover, WO 2010/066448 discloses a device for conveying a gas from a pressure chamber, in particular for discharging a sealant from this container into a tire of a vehicle and/or for inflating the tire, wherein a piston is arranged to be oscillatingly movable in the pressure chamber. A gear element is also assigned to the piston and converts a rotational movement of the input shaft of a drive into an oscillating movement.

Problem

The problem addressed by the present invention is that of simplifying and improving known compressors for conveying a gas from a pressure chamber and for transporting a medium. Solution to the problem

The problem is solved by the fact that the step-up transmission wheel is provided only partially on its circumference with a toothing and/or consists of two toothed wheels lying on each other.

In one illustrative embodiment of the present invention, the compressor has a motor which is connected eccentrically to a piston rod via an output wheel, which piston rod moves a piston in the compression chamber. According to the invention, provision is made that the step-up transmission wheel is arranged upstream from the output wheel. The step-up transmission wheel and output wheel are adapted to each other such that a different transmission of force can take place depending on which toothings are in engagement. For this purpose, provision is made that the output wheel consists of two wheel halves that lie on each other. Each wheel half has a toothing, but the latter does not extend over the entire circumference, and instead only over a predetermined arc distance. In the preferred illustrative embodiment, this arc distance is in each case 180°.

By contrast, the step-up transmission wheel consists of two toothed wheels which lie on each other and which interact alternately with one or other wheel half of the output wheel. One toothed wheel has a greater diameter than the other toothed wheel. The toothed wheel with the smaller diameter can apply a greater force to the output wheel than can the toothed wheel with the greater diameter. Therefore, the toothed wheel with the smaller diameter engages in the corresponding toothing of the output wheel when air is to be compressed into the compression chamber. By contrast, if air is only to be sucked in, the toothed wheel with the greater diameter engages in the toothing of the output wheel half assigned to it. In a further illustrative embodiment of the invention, the step-up transmission wheel is provided only partially on its circumference with a toothing. This toothing alternately engages in at least two toothings of a fork element on which at least one piston is provided. The function is such that, with the direction of rotation remaining constant, the step-up transmission wheel engages alternately in the different toothings and thus causes a different movement of the piston. In a preferred illustrative embodiment, the piston is connected to a fork element which forms an elongate opening into which the step-up transmission wheel engages. Two opposite side flanks of this fork element enclose this elongate opening more or less elliptically, wherein the side flanks on the inside of the elongate opening are provided with the toothings lying opposite each other. By contrast, the step-up transmission wheel is provided with a toothing over only about half of its circumference. If this step-up transmission wheel now rotates about its axis, the arrangement is configured such that the toothing of the step- up transmission wheel initially runs along an inner toothing of the fork element and, at the end of this toothing, engages with at least one tooth in the opposite toothing. This brings about a movement of the fork element in the opposite direction, as a result of which the piston is moved to and fro in the compression chamber.

In a preferred illustrative embodiment, however, the fork element is connected to in each case one piston at both ends. It is also conceivable here that the fork element is also connected to several pistons via a corresponding joint and corresponding piston rods, which pistons move in corresponding compression chambers. This allows a corresponding compressor according to the invention to be arranged in a wheel rim, specifically in a five-hole wheel rim, since the corresponding pistons are then able to move between the holes.

In these arrangements, a transmission of force and a distribution of the pressure forces to different compression chambers are greatly improved. Description of the figures

Further advantages, features and details of the invention will become clear from the following description of preferred illustrative embodiments and from the drawing, in which

Figure 1 shows a perspective view of a compressor according to the invention; Figure 2 shows a plan view of the compressor according to Figure 1 ;

Figure 3 shows a partial view of the compressor according to Figure 2 seen in direction X; Figure 4 shows a perspective view of the interaction between a step-up transmission wheel and an output wheel;

Figures 5-8 show schematic plan views of a further illustrative embodiment of part of a compressor according to the invention in different positions of use;

Figures 9 and 10 show schematic plan views of two further illustrative embodiments of parts of a compressor according to the invention.

According to Figure 1 , a compressor P according to the invention has a motor 1 , which is cooled by a fan 2. A step-up transmission wheel 3, which sits on a motor shaft (not shown), interacts with an output wheel 4.

The output wheel 4 is connected eccentrically to a piston rod 5, which moves a piston 6 (Figure 3) in a compression chamber 7. A valve piece 8, which has a line 9 to a tire, for example, and has a connection 10 to a container for tire sealant, for example, is attached to this compression chamber 7. This compressor functions as follows:

The step-up transmission wheel 3 is moved in rotation via the motor 1 and transmits its rotational movement to the output wheel 4. The latter in turn moves the piston rod 5 in the compression chamber 7. In this way, air is forced out of the compression chamber 7 into the valve piece 8 and into the line 9. A medium, in particular tire sealant, is then either sucked in from a container (not shown) via the connection 10 or is additionally forced into the line 9 and thus introduced, for example, into a tire that is to be sealed.

The present invention relates in part to an improvement of the force transmission of the force of the motor 1 to the piston rod 5 or the piston 6. It is known that more force is needed when compressing the air in the compression chamber 7 than when sucking new air into the compression chamber. To take account of this force relationship, both the step-up transmission wheel 3 and also the output wheel 4 are preferably formed in two parts. According to Figure 4, the step-up transmission wheel 3 consists of two toothed wheels 1 1 and 12 which lie on each other and which have a congruent opening 13 for receiving a motor shaft. Moreover, the toothed wheel 1 1 also has a greater diameter than the toothed wheel 12.

The output wheel 4 consists of two halves 4.1 and 4.2. Each half is provided with a toothing 14.1 and 14.2, respectively. Each toothing 14.1 and 14.2 extends over only a half circumference of the respective output wheel half 4.1 , 4.2, while the other half is free of toothing. Here too, provision is made that the output wheel half 4.2 with the toothing 14.2 has a greater diameter than the output wheel half 4.1 with the toothing 14.1 . The toothed wheel 12 with the smaller diameter interacts with the output wheel half 4.2 with the greater diameter, while the toothed wheel 1 1 with the greater diameter interacts with the output wheel half 4.1 with the smaller diameter. As soon as the toothed wheel 12 with the smaller diameter comes into engagement with the toothing 14.2 of the output wheel half 4.2, a greater force can thus be applied by the step-up transmission ratio, such that this state of engagement is preferred when a greater force is intended to act on the piston 6 during the compression. When the piston 6 retreats in order for new air to be sucked into the compression chamber 7, the toothed wheel 1 1 with the greater diameter is then in engagement with the toothing 14.1 of the output wheel 4.1 with the smaller diameter.

Figures 5 to 8 show a further illustrative embodiment of a possible actuation of two pistons 6.1 and 6.2 in two compression chambers (not shown). The two pistons 6.1 and 6.2 are connected to each other via a fork element 15. For this purpose, the fork element 15 has two curved side flanks 16.1 and 16.2 which connect two connector stubs 17.1 and 17.2 on the pistons 6.1 and 6.2 to each other. The side flanks 16.1 and 16.2 enclose an elongate opening 18, and, within the interior of this elongate opening 18, parts of the side flanks 16.1 and 16.2 extending approximately parallel to each other are provided with a toothing 19.1 and 19.2, respectively.

A step-up transmission wheel 3.1 , approximately half of which is provided with a further toothing 20, engages in this elongate opening 18.

This illustrative embodiment of a gear according to the invention, in particular for compressors, functions as follows:

The step-up transmission wheel 3.1 , which sits on a shaft of a drive, rotates about its axis A. In doing so, the toothing 20 of the step-up transmission wheel 3.1 runs along the inner toothing 19.1 of the side flank 16.1 , such that the fork element 15 moves downward according to the arrow 21 when the step-up transmission wheel 3.1 is fixed in position. During this, the piston 6.2 moves deeper into its compression chamber and forces the fluid or gas contained therein out of this compression chamber. At the same time, the piston 6.2 moves out from its associated compression chamber and sucks in fluid or gas. Figure 6 shows the step-up transmission wheel 3.1 running along the toothing 19.1 , the step-up transmission wheel 3.1 here being located approximately at the middle of the elongate opening 18. According to Figure 7, an uppermost tooth 22 of the toothing 20 of the step-up transmission wheel 3.1 has now reached an uppermost tooth 23 of the toothing 19.1 . At the same time, an opposite tooth 24 engages under an uppermost tooth 25 of the opposite toothing 19.2. Upon further rotation of the step-up transmission wheel 3.1 , the toothing 20 engaging in the toothing 19.2 carries the fork element 15.1 in the opposite direction, as is shown by the arrow 26. Figure 8 shows the corresponding central position of the step-up transmission wheel 3.1 in the elongate opening 18.

Finally, the tooth 24 of the toothing 20 of the step-up transmission wheel 3.1 reaches a lower tooth 27 of the toothing 19.1 and the position of use shown in Figure 5, wherein the opposite tooth 22 again unlatches from the toothing 19.2. The tooth 24 now comes into engagement with the toothing 19.1 , as is shown in Figure 5. Figure 9 shows that the fork element 15 according to the invention can also interact with three pistons. For this purpose, instead of the piston 6.2, two piston rods 5.1 and 5.2 are connected to the fork element 15 via a joint 28. A piston 6.3, 6.4 is provided at the other end of the piston rods 5.1 , 5.2, respectively. In Figure 10, the fork element 15 actuates two mutually opposite pairs of pistons 6.3, 6.4 and 6.5, 6.6, wherein the pair 6.5, 6.6 replaces the piston 6.1 and is connected to the fork element 15 via corresponding piston rods 5.3 and 5.4, respectively, and via a joint 28.1 . However, the process of movement of the arrangement according to Figure 9 and Figure 10 corresponds to the details concerning the function of the illustrative embodiment according to Figures 5 to 8. List of reference signs