Abstract:
A device having a pusher for pushing glass objects from a resting plate to a conveyor belt moving at a uniform speed. The device has first, second and third electric motors, the first motor mounted to be stationary, and the second and third motors being moveable relative to the first motor. The three motors are connected to the pusher via various transmission parts and controlled independently for controlling the motion of the pusher.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a device for pushing glass objects from a dead plate of an I.S. glassware forming machine onto a conveyor belt. 
     Such devices are intended to transfer the glass object, in particular a hollow glass object, which has been removed from a blow-mold of a glassware forming machine and placed on a stationary dead plate. The device then transfers the glass object by means of a pusher to a conveyor belt moving continuously at a uniform speed. The glass objects must be positioned on the conveyor belt one behind the other to be subsequently introduced into a lehr. In the case of I.S. (individual section) machines where the conveyor belt co-operates with a plurality of manufacturing stations, each of which is provided with a dead plate, the process of pushing the glass objects must take place within a time interval dependent upon the operating cycle of the remaining manufacturing stations and upon the transport speed of the belt. Moreover, the pushing procedure must be performed so as to avoid toppling of or damage to the glass objects and imprecise positioning on the belt. At the end of the movement along a transfer curve, each glass object must be arranged in a defined position on the belt and move with it in the same direction and at the same speed. 
     Document DE 10 2004 010 238 133 discloses a device of this type in which a first lever which at one of its ends can pivot about a vertical, positionally-fixed axis supports at its other end one end of a second lever which can also pivot about a vertical axis, the other end of the second lever having a pusher mounted thereon, said pusher in turn being pivotable about a perpendicular axis and being fitted with three pushing fingers. Allocated to the rotations of the first lever about the positionally-fixed axis, of the second lever with respect to the first lever and of the pusher with respect to the second lever are three positionally-fixed drives which can be controlled in a mutually independent manner, wherein a transfer curve beginning at a point of reception on the dead plate and ending at a point of delivery on the conveyor belt can be produced by the superposition of the three partial movements generated by the drives. The transfer of the rotational movements of the three drives via the levers to the pusher is effected by means of toothed belt gear mechanisms, the operation of which requires a great deal of maintenance. This is accompanied by a comparatively large constructional outlay which is governed by an initial combination of the driving movements of three fixedly disposed drives via hollow shafts guided one inside the other and subsequent separation of these movements for their introduction into the respective component whose rotational movement is to be controlled. 
     Document DE 2008 027 911 A1 discloses a further comparable device in which the pusher is fixedly connected to the end of a crank arm which is connected to a shaft in a rotationally-fixed manner, said shaft being mounted in a rotatable manner on a rotary disk eccentrically with respect to its positionally-fixed axis extending in parallel with said shaft. Said shaft forms the driven shaft of a first electric motor also supported by the rotary disk, wherein the rotary disk is drivingly connected directly with a second, positionally-fixed electric motor. This design indeed allows a simplification in the gear elements necessary for transferring the partial movements of the two electric motors, wherein, however, in comparison with the device known from document DE 10 2004 010 238 B3, there are fewer design options for producing a transfer curve since only two partial movements are to be superposed and the pusher is not pivoted with respect to said crank arm. 
     Finally, EP 1 886 977 A1 discloses a further device for pushing glass objects onto a conveyor belt, in which two electric motors disposed in a machine frame coaxially with respect to each other are fixedly connected to crank arms at the respective ends of their driven shafts, wherein the free end of one crank arm is articulated via a joint directly on a structure supporting a pusher and wherein the free end of the other crank arm is articulated via a joint with an intermediate lever and this, at its end remote from the crank arm, is articulated via a further joint on said structure. The axes of all the joints extend in parallel with each other. By controlling the two electric motors to rotate in the same direction, it is possible to produce a rotational movement of the pusher about the common axis of the two motors, wherein by way of the control to rotate in the same direction, it is possible to move the pusher closer to or further away from a dead plate or a conveyor belt. The transfer curve starting from a dead plate to a conveyor belt is thus a circular arc about the common axis of the two motors. Since only two partial movements are to be superposed, there are also fewer design options for the transfer curve in the case of this device compared with that described in document DE 10 2004 010 238 B3. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to improve a device of the type mentioned above in a simple manner with the design options for the transfer curve being optimum and in particular tailored to requirements. This object is achieved by the present invention which provides a device for pushing glass objects from a dead plate of a section of an I.S. (individual section) glassware forming machine onto a moving conveyor belt. The device includes a pusher for pushing the glass objects and which is mounted on one end of a lever so as to be pivotable about a first vertical axis. The other end of the lever is connected to a vertically extending shaft which is mounted so as to be pivotable about a second vertical axis, wherein the shaft is disposed so as to be eccentrically rotatable about a positionally-fixed, vertically extending axis. A first electric motor is arranged to produce a rotational movement of the shaft about the fixed axis, is positionally-fixed, and has a vertically extending driven shaft. A second electric motor is arranged to produce a rotational movement of the shaft about the second vertical axis, and a third electric motor is arranged to produce a rotational movement of the pusher about the first vertical axis relative to the lever. 
     Accordingly, it is important for the invention that of the three electric motors, only one is positionally-fixed, with the other two, in contrast, mounted so as to rotate with a beam mounted in a positionally-fixed manner so as to be able to pivot about a vertical axis. The latter two motors are thus held eccentrically in relation to the positionally-fixed axis. With respect to the Prior Art mentioned above, in the case of embodiments in which three positionally-fixed electric motors, which can be controlled in a mutually independent manner, are present for the provision of three partial movements, as a result of the omission of gear components which are used for the initial, spatial combination and for the transfer of the partial movements, a considerably reduced constructional outlay is achieved. With respect to the Prior Art, in the case of embodiments in which two electric motors which can be controlled in a mutually independent manner are present for the provision of two partial movements, of which one electric motor is positionally-fixed, the advantage of improved options for producing, and in particular varying, the transfer curve is produced. The smaller number of parts, compared with known devices comprising three axes to be controlled, provides savings in production, assembly and maintenance. 
     The features of the invention are also directed towards an advantageous formation of the means for the pivoting of the pusher with respect to the crank arm supporting it. The four bar chain used in this case and incorporating a push rod can be considered as being low-maintenance and on the whole robust. It is particularly suitable for use under the operating conditions of a glass factory. 
     Further features of the invention are directed towards the arrangement and design of a receiving body connected to the beam and acting as a support for the two electric motors moving with the beam. One of the two receptacles continues as a preferably cylindrical projection part which extends coaxially with respect to the receptacle and in which there is mounted an annular body receiving the point of articulation of the push rod, with the interposition of a hollow shaft. A cover part, from which the sleeve extends on the upper side, forms the upper termination for the receiving body. The projection part is preferably formed in one piece with the cover part. The beam and the receiving body can also be formed in one piece with each other. 
     In another embodiment of the invention, the driving connection between the third electric motor and the hollow shaft is arranged via a spur gear mechanism. This is the only gear mechanism which is required in terms of transferring the driving movements of the three electric motors. 
     In still further embodiments, additional features are directed towards the design of a housing which at least partially receives the electric motors and transfer members disposed downstream thereof. This housing is formed to be closed and on the upper side is characterized by a protective sheet from which only the projection part mentioned in the introduction protrudes. The term “vertical” used in the previous embodiments and hereinafter is directed towards a flat base side of this housing. It is important that all the important components of the device are disposed to be protected from external influences arising from the operation of a glass factory. 
     The features of yet additional embodiments of the invention are directed towards the arrangement of the positionally-fixed electric motor within the housing. This is held in a frame fixed to the housing and for bearing the beam a hollow cylinder fixedly connected thereto is provided, by means of which the beam is mounted on a hollow shaft-like hub so as to be rotatable about its axis, wherein the driven shaft of the first electric motor extends within the hub. In this manner a stable bearing of the beam is provided which is particularly suitable for withstanding stresses. 
     Further protection of the device against the effects of heat, moisture, abrasive dust, etc. is achieved by the housing being disposed below the plane of a dead plate. 
     The mechanical concept of the device, unlike in the Prior Art illustrated above in which not many rotational movements are guided within each other, allows the use of stable carrier-support bearings whose dynamic load ratings turn out to be high which means that a correspondingly long service life is to be expected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail hereinafter with reference to the exemplified embodiment schematically illustrated in the drawings, in which: 
         FIG. 1  shows an illustration of the device in accordance with the invention in a vertical sectional plane; 
         FIG. 2  shows a partially angularly offset illustration of the device of  FIG. 1  in a sectional plane II-II; 
         FIG. 3  shows a plan view of the device along viewing direction III of  FIG. 1 ; and 
         FIG. 4  shows a perspective top view of the device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference numeral  1  designates a first electric motor disposed in a frame  2  in a positionally-fixed manner, the driven shaft  3  of which is connected to a beam  4  in a rotationally-fixed manner. The driven shaft  3  extends through a hollow shaft-like hub  52  and the beam  4  is connected to a hollow cylinder  5  surrounding the hub  52 , the beam being mounted on the hub  52  via the hollow cylinder by means of roller bearings  6 ,  7 . 
     The beam  4  which is thus mounted so as to be rotatable about a vertical, positionally-fixed axis  8  supports at its end remote from the axis  8  a receiving body  9  which, as shown in  FIG. 2 , comprises two cylindrical receptacles  10 ,  11  which are disposed next to each other and whose axes extend in parallel with the axis  8 . 
     A second electric motor  12  is inserted into the lower portion of the receptacle  10  and a third electric motor  13  is inserted into the lower portion of the receptacle  11 . 
     The shaft  14  mounted within the receptacle  10  via roller bearings  15 ,  16  is the driven shaft of the electric motor  12  and this is connected at its upper end to a crank arm  17  in a rotationally-fixed manner, which crank arm extends substantially perpendicular with respect to the shaft  14 . The end of the crank arm  17  is articulated on a pusher  18  so as to be pivotable about a perpendicular axis  19 . 
     A cylindrical projection part  20  is attached at its upper side to the receptacle  10  and has a first hollow shaft  24  mounted therein via roller bearings  21 ,  22 , which hollow shaft extends coaxially with respect to the axis  23  of the driven shaft  14  and at its lower end supports a toothed ring  25 . At its upper end, the hollow shaft  24  is fixedly connected to an annular body  26  on which one end of a push rod  28  is pivotably articulated about an axis  27 , the other end of which is articulated on the pusher  18  so as to be pivotable about an axis  29  at a spaced disposition with respect to the axis  19 . 
     The crank arm  17  forms together with the push rod  28  a four bar chain owing to the arrangement of the axes  19 ,  23 ,  27 ,  29  which means that in dependence upon a rotation of the hollow shaft  24  about the axis  23 , a rotation of the pusher  18  about the axis  19  relative to the crank arm  17  can be produced. 
     The toothed ring  25  is engaged with a toothed ring  30  which is integrally formed on a second hollow shaft  53  connected to the driven shaft  31  of the third electric motor  13  in a rotationally-fixed manner and extending coaxially with respect thereto. The driven shaft  31  of the electric motor  13  is mounted by means of roller bearings  32 ,  33  in a cylindrical projection part  34 —projecting into the receiving body  9 —of a cover part  35  which is fixedly connected to the projection part  20 . The two toothed rings  25 ,  30  form the only spur gear mechanism used in terms of the device. 
     Fastened to the pusher  18  in a manner known per se is an arrangement of pushing fingers  36  which are intended to push the glass objects. 
     As shown above, the first electric motor  1  is drivingly connected to the receiving body  9  and thus the projection part  20  which on its upper side protrudes from a recess  38  formed in a cover  37 . Disposed in this recess  38 , the shape of which can be seen in  FIG. 3 , is the projection part  20  in such a manner as to be eccentrically pivotable about the positionally-fixed axis  8 , reciprocating within this recess  38  by means of the electric motor  1 . 
     The second electric motor  12  is drivingly connected to the crank arm  17 , in particular with regard to the production of a rotational movement of the point of articulation, which can be defined by the position of the axis  19 , on the pusher  18  relative to the axis  23  of the driven shaft  14  which can move together with the beam  4 . 
     The third electric motor  13  is drivingly connected, via the mutually engaged toothed rings  25 ,  30 , to the annular body  26  and thus the push rod  28  for producing a rotational movement of the pusher  18  relative to the crank arm  17  about the axis  19 . 
     Reference numeral  49  designates a housing, within which the electric motors  1 ,  12 ,  13  and the gear parts mentioned above are disposed and are protected against environmental influences. In addition, a protective sheet  50  is provided which forms the upper termination and is provided merely with one opening adapted to the projection part  20 . The protective sheet  50  moves during operation of the device together with the projection part  20  and is connected to the housing  49  with the interposition of a seal  51 . 
     The space delimited by the receptacles  10 ,  11  and the projection part  20  and closed on the upper side by the cover part  35  and the annular body  26  can be filled with oil since this space is closed on the lower side by facing housing parts of the electric motors  12 ,  13 . In this manner, a lubrication system geared towards the service life of the device can be produced. 
     Bearing points which are subjected to a great deal of heat can be formed as dry sliding bearings which are considered to require no maintenance and are simpler to replace than roller bearings. 
     In order to explain the pushing movement, reference is made hereinafter in particular to  FIG. 3 . 
     Reference numeral  39  designates a dead plate, positioned on which by way of example are three glass objects  40 , which are to be pushed, in an arrangement extending perpendicularly with respect to a direction  41 , in which the conveying direction of a conveyor belt  42  moving at a uniform speed extends. 
     By correspondingly controlling the electric motors  1 ,  12  and  13 , partial movements are now generated, the superposition of which being able to produce a closed curve  43  along which the points of articulation of the pusher  18 , which can be defined by the positions of the axes  19 ,  29 , and thus the pusher itself moves between a starting position, which is characterized by the pushing fingers  36  abutting against the stationary glass objects  40  on the dead plate  35  for the first time, along a curved path  44  to a point of delivery  45  at which the pushing fingers  36  are released from the glass objects  40 , in that they are moved back approximately perpendicularly with respect to the conveying direction  41  along a portion  46  in order then in turn to be moved back into the starting position via a curved path  47  and a portion  48  for grasping a further group of glass objects  40 . 
     In the point of delivery  45 , the pushing fingers  36  move at the same speed as the conveyor belt  42 . The superposition of said three partial movements can be arranged such that the curve  43  issues before the point of delivery  45  tangentially in a point in the direction  41  which means that subsequent thereto the pushing fingers  36  move along a linear path element subsequent to said point in the same direction and at the same speed as the conveyor belt  42 . This ensures a smooth transfer preventing the glass objects from toppling over and similarly from being inaccurately positioned on the conveyor belt  42 . 
     The curve  43  is further configured with the proviso that the glass objects  40  are arranged on the conveyor belt  42  one behind the other in the direction  41 . 
     The time taken to travel the curve  43  thus defines the operating cycle of the device. 
     LIST OF REFERENCE NUMERALS 
     
         
           1 . Electric motor 
           2 . Frame 
           3 . Driven shalt 
           4 . Beam 
           5 . Hollow cylinder 
           6 . Roller bearing 
           7 . Roller bearing 
           8 . Axis 
           9 . Receiving body 
           10 . Receptacle 
           11 . Receptacle 
           12 . Electric motor 
           13 . Electric motor 
           14 . Shaft 
           15 . Roller bearing 
           16 . Roller bearing 
           17 . Crank arm 
           18 . Pusher 
           19 . Axis 
           20 . Projection part 
           21 . Roller bearing 
           22 . Roller bearing 
           23 . Axis 
           24 . Hollow shaft 
           25 . Toothed ring 
           26 . Annular body 
           27 . Axis 
           28 . Push rod 
           29 . Axis 
           30 . Toothed ring 
           31 . Driven shaft 
           32 . Roller bearing 
           33 . Roller bearing 
           34 . Projection part 
           35 . Cover part 
           36 . Pushing finger 
           37 . Cover 
           38 . Recess 
           39 . Dead plate 
           40 . Glass object 
           41 . Direction 
           42 . Conveyor belt 
           43 . Curve 
           44 . Path 
           45 . Point of delivery 
           46 . Portion 
           47 . Path 
           48 . Portion 
           49 . Housing 
           50 . Protective sheet 
           51 . Seal 
           52 . Hub 
           53 . Hollow shaft