Patent Publication Number: US-10759551-B2

Title: Ejection head for an ejection device of a sealing machine for sealing a container

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to European Application No. 17151734.5, filed Jan. 17, 2017, the contents of which are hereby incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The invention relates to an ejection head for an ejection device of a sealing machine, an ejection device for a sealing machine and a sealing machine for sealing a container. 
     Background of the Invention 
     To explain a known ejection head, reference is made below to  FIG. 1  and  FIG. 2 , on the basis of which the prior art will be described in more detail. To distinguish the prior art from the present invention, the reference signs, which refer to features of known examples are provided with an inverted comma, while features of embodiments according to the invention are provided with reference signs which have no inverted comma. 
       FIG. 1  shows the structure of a known ejection head  1 ′ and  FIG. 2  the known ejection head  1 ′ of  FIG. 1  in the operating state. 
     According to  FIG. 1 , the ejection head  1 ′ comprises a supporting element  2 ′ with a supporting axis  3 ′ and a sliding end  4 ′, and a sliding element  5 ′ for sliding the supporting element  2 ′ along a sliding profile of the sealing machine. The sliding element  5 ′ is arranged at the sliding end  4 ′ and can transmit a force acting essentially in the direction of the supporting axis  3 ′ to the supporting element  2 ′. In the known ejection head  1 ′, the sliding element  5 ′ has a rounded surface. 
     In the operating state, the ejection head  1 ′ is connected to an ejection rod. Thereby, the ejection head  1 ′ and the ejection rod form a part of an ejection device. The force can be transmitted to the ejection rod via the supporting element. 
       FIG. 2  shows the known ejection head  1 ′ in the operating state. Thereby, the ejection head  1 ′ slides with the sliding element  5 ′ along a sliding profile  6 ′ of the sealing machine. In order to achieve the two functions of holding down the container and of ejecting the container, the sliding profile  6 ′ has two sections with an elevated level. Thus, the one section with an elevated level of the sliding profile  6 ′ corresponds to the function of holding down the container, in which the container to be sealed is held for the sealing operation by the ejection device and is centered for the lid sealing. The other section with an elevated level of the sliding profile  6 ′ corresponds to the function of ejecting the container, in which the sealed container is ejected from the sealing machine by the ejection device. During the procedure of holding down the container and of ejecting the container, the ejection head  1 ′ is moved along the sliding profile  6 ′ and can also rotate around its supporting axis  3 ′. The rounded surface of the sliding element  5 ′ performs a sliding movement along the sliding profile  6 ′. Thereby, the rounded surface is lubricated by an oil jet (not shown), so that a lubricating film builds up between the rounded surface and the sliding profile  6 ′. 
     SUMMARY 
     An essential disadvantage of the known ejection head is, that the movement performed by it along the sliding profile is basically a sliding movement. This sliding movement leads to increased wear of the sliding profile and the sliding element. Furthermore, there is the risk, that the lubricating film tears off between the sliding profile and the sliding element. Both issues lead to an increased load on the sealing machine due to vibrations, which has a negative effect on the smooth running and the energy consumption of the sealing machine. In particular, as a result of the increased wear, the sliding profile and/or the sliding element must be replaced frequently. Furthermore, the risk of tearing off the lubricating film requires extensive lubrication. 
     Based on this prior art, it is therefore an object of the invention to propose an ejection head for an ejection device of a sealing machine, an ejection device for a sealing machine and a corresponding sealing machine for sealing a container, all of which involve reduced wear, cause reduced energy consumption, include an improved and simplified lubricity and have increased smooth running. 
     The objects of the invention meeting this problem are characterized by the features of the embodiments described herein. 
     Thus, the invention relates to an ejection head for an ejection device of a sealing machine for sealing a container comprising a supporting element with a supporting axis and a sliding end and a sliding element for sliding the supporting element along a sliding profile of the sealing machine, wherein the sliding element is arranged at the sliding end and a force acting essentially in the direction of the supporting axis can be transmitted via the sliding element to the supporting element. 
     According to the invention, the sliding element is designed as a rotatable rolling element, so that in the operating state the supporting element can be unrolled over the rotatable rolling element along the sliding profile. 
     That is to say, in the framework of this invention, the sliding element performs a rolling movement at the sliding profile. The sliding element can rotate freely relative to the supporting element in order to perform the rolling movement. This essentially means that the sliding element can rotate around two different axes. On the one hand, it can rotate around the supporting axis. On the other hand, it can also rotate around an axis which is perpendicular to the direction of movement and which varies during the movement of the sliding element at the sliding profile. This is in contrast to the prior art, where the sliding element is rigidly connected to the supporting element and performs a pure sliding movement at the sliding profile. 
     It is an essential advantage of the ejection head according to the invention that due to the rolling movement of the sliding element at the sliding profile, the wear of the sliding element and the sliding profile is reduced. As a result, the service life of the ejection head and the sliding profile or the change intervals of the ejection head and the sliding profile can be extended. Furthermore, an increased smooth running is achieved by the rolling movement of the sliding element at the sliding profile resulting in a reduced energy consumption of the sealing machine and a decreased load on the sealing machine due to vibrations. In addition, the ejection head according to the invention improves the lubricity of the ejection head and simplifies the lubricating. 
     In an embodiment, which is very important in practice, the ejection head additionally comprises a bearing element, via which the rotatable rolling element is mounted at the supporting element. Due to the bearing element, the lubrication of the rolling element is simplified, the rolling movement of the rolling element is improved, the wear of the rolling element and the sliding profile is reduced and the heat generation at the rolling element and the sliding profile is decreased. Furthermore, the positioning of the rolling element at the ejection head is improved by the bearing element. 
     It has proved to be advantageous when the bearing element is detachably connected to the supporting element. As a result, the bearing element can be replaced separately, whereby costs can be reduced at the sealing machine. 
     It is also advantageous the bearing element and/or the rotatable rolling element having a hardened surface, in particular a hard coating. Hence, the wear of the bearing element and/or the rotatable rolling element can be reduced, which results in an extended service life of the bearing element and/or the rotatable rolling element. 
     It is also advantageous when the bearing element and/or the rotatable rolling element are made of metal and/or plastic and/or a ceramic material and/or a composite material. This also reduces the wear of the bearing element and/or the rotatable rolling element, which results in an extended service life of the bearing element and/or the rotatable rolling element. 
     In another embodiment, which can be very important in practice, the ejection head additionally comprises a holding element, via which the rotatable rolling element is held in the bearing element. Due to the holding element, improved securing of the rolling element is achieved at the ejection head. Furthermore, improved lubricity of the rolling element is achieved. 
     In practice, it has also proven to be advantageous that the rotatable rolling element be designed as a ball or an ellipsoid. As a result, an optimal linear and axial rolling movement of the ejection head is ensured at the sliding profile. 
     Furthermore, it is advantageous that the ejection head additionally comprises a spring element, via which the rotatable rolling element can be pressed against the sliding profile in the operating state. A continuous contact between the rolling element and the sliding profile is ensured by the spring element. In addition, the contact force, with which the rolling element abuts the sliding profile, can be adjusted via the spring element. Unevenness of the rolling element and/or the sliding profile can be compensated via the spring element resulting in an increased smooth running of the sealing machine. 
     In practice, it has also proven to be advantageous for the spring element to be designed as a spiral spring. This allows a simplified construction of the ejection head. 
     The present invention further relates to an ejection device for a sealing machine for sealing a container with an ejection rod and an ejection head according to the invention. 
     The present invention also relates to a sealing machine for sealing a container comprising an ejection device and a sliding profile, wherein the ejection device comprises an ejection rod and an ejection head and the ejection head having a sliding element, which is designed as a rotatable rolling element and via which the ejection head can be unrolled along the sliding profile in the operating state. 
     In an embodiment, which can be very important in practice, the sliding profile has a groove suitable for receiving and/or guiding the rotatable rolling element. As a result, the Hertzian stress between rolling element and sliding profile can be reduced. Furthermore, the rolling movement and guiding of the rolling element can be improved on the sliding profile. 
     It is also advantageous for the sliding profile to have a hardened surface, in particular a hard coating. As a result, the wear of the sliding profile can be reduced or the service life of the sliding profile can be extended. 
     Furthermore, it has proven to be advantageous, when the sliding profile is made of metal and/or plastic and/or a ceramic material and/or a composite material. As a result, the wear of the sliding profile can be reduced or the service life of the sliding profile can be extended. 
     Preferably, but not necessarily, the sealing machine may additionally comprise a sliding profile support with which the sliding profile is detachably connected. Thus, the sliding profile can be replaced separately at the sealing machine, which results in a cost reduction of the sealing machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail hereinafter with reference to the drawings. 
         FIG. 1  is a known ejection head from the prior art, 
         FIG. 2  is the known ejection head from  FIG. 1  at a sliding profile in the operating state, 
         FIG. 3  is an embodiment of an ejection head according to the invention, 
         FIG. 4  is an embodiment of an ejection device according to the invention with an ejection rod and an ejection head according to  FIG. 3 , 
         FIG. 5  is the ejection head according to the invention according to  FIG. 3  at a sliding profile in the operating state, and 
         FIG. 6  is a detailed view X according to  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     As already mentioned,  FIG. 1  and  FIG. 2  show the prior art and have already been explained in detail at the beginning, so that there is no need for further discussion. 
       FIG. 3  shows a first embodiment of an ejection head according to the invention, which is referred to as a whole with the reference sign  1  in the following. The reference signs used in  FIG. 3  to  FIG. 6  do not have an inverted comma, since these figures relate to embodiments of the present invention. As already mentioned above, only the reference signs of  FIGS. 1 and 2  have an inverted comma, since these relate to the known prior art. 
     According to  FIG. 3 , the ejection head  1  comprises a supporting element  2  with a supporting axis  3  and a sliding end  4  and a sliding element  5  for sliding the supporting element  2  along a sliding profile of the sealing machine. Thereby, the sliding element  5  is arranged at the sliding end  4  and can transmit a force acting essentially in the direction of the supporting axis  3  to the supporting element  2 . The sliding element  5  is designed as a rotating rolling element in the form of a ball. The ejection head  1  additionally comprises a bearing element  7  and a holding element  8 , via which the rotatable rolling element  5  is mounted or held at the supporting element  2 . 
       FIG. 4  shows the ejection head  1  from  FIG. 3  and an ejection rod  9 , to which the ejection head  1  is detachably connected. Thereby, the ejection head  1  and the ejection rod  9  form a part of an ejection device  10  of a sealing machine, not shown, for sealing containers. A force can be transmitted to the ejection rod  9  via the ejection head  1  in the operating state. The ejection device  10  is movably mounted along its longitudinal axis  12  and rotatably mounted around the longitudinal axis  12  in a receiving device  11  of the sealing machine. The receiving device  11 , in turn, is rotatably mounted in a holding device (not shown) of the sealing machine by receiving bearings (not shown). 
     A first gear ring  14  is disposed at the upper end of the receiving device  11 , which gear ring interacts with a second gear ring (not shown) of the sealing machine in the operating state. The receiving device  11  and the ejection device can be set to intrinsic rotation via the first gear ring  14 . The movement of the receiving device  11  and the ejection device  10  along the sliding profile  6 , however, is generated via the holding device of the sealing machine. 
       FIG. 5  shows the ejection device  10  with the ejection head  1  according to  FIG. 3  in the operating mode. In doing so, the ejection head  1  slides with the rotating rolling element  5  along the sliding profile  6  of the sealing machine, which sliding profile is connected to a sliding profile support  15  of the sealing machine. In order to achieve the two functions of holding down the container and of ejecting the container, the sliding profile  6  has two sections with an elevated level. Thereby, the one section with an elevated level of the sliding profile  6  corresponds to the function of holding down the container, in which the container to be sealed is held for the sealing operation by the ejection device and is centered for the lid sealing, and the other section with an elevated level of the sliding profile  6  corresponds to the function of ejecting the container, in which the sealed container is ejected from the sealing machine by the ejection device. During the procedure of holding down the container and of ejecting the container, the ejection head  1  is moved along the sliding profile  6  and can also rotate around the longitudinal axis  12  of the ejection device  10 . 
     The rotating rolling element  5  performs a rolling movement at the sliding profile  6 . The sliding element  5  can rotate freely relative to the supporting element  2  in order to perform the rolling movement and thereby rotate essentially around two different axes. On the one hand around the supporting axis  3 . On the other hand, also around an axis which is perpendicular to the direction of movement and which varies according to the direction of movement during the movement of the rotating rolling element  5  at the sliding profile  6 . This, in contrast to the prior art, where the sliding element  5 ′ is rigidly connected to the supporting element  2 ′ and performs a pure sliding movement at the sliding profile. 
       FIG. 6  shows a detailed view X according to  FIG. 5 . As can be seen, the sliding profile  6  has a suitable groove or a notch  16  for receiving and/or guiding the rotatable rolling element  5 . Due to the groove or notch  16 , the Hertzian stress between the rotating rolling element  5  and the sliding profile  6  can be reduced. 
     Furthermore, the rolling movement and guidance of the rotating rolling element  5  at the sliding profile  6  can be improved.