Patent Publication Number: US-9421797-B2

Title: Printer having separating device

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 U.S.C. §371 of PCT International Application No. PCT/EP2013/059794 filed May 13, 2013, based on the German Application No. 20 2012 101 998.1 filed May 31, 2012. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Printing apparatus is provided for printing information on a vertical stack of horizontal vertically-spaced planar objects arranged in a housing, including a separating arrangement for removing the lowermost object from the stack, and a printing device for printing information on the removed object. The stack is supported by a plurality of support arrangements each including a support member mounted for reciprocatory horizontal displacement by an electromagnetic drive device between positions that are adjacent and remote from the stack, respectively. Each support member is guided during this displacement by a guide arrangement including at least one guide lever having a first end pivotally connected with the housing, and a second end connected with a guide follower roller that is in engagement with a guide cam surface carried by the support member. 
     2. Description of Related Art 
     In the patented prior art, it is known from German patent No. DE 197 58 483 C2 to provide a printer for printing media such as plastic cards or mats with labels. These printing media have a relatively great material thickness, so that the requirements imposed on the printer are different from those for customary paper printers. In particular it is necessary to ensure that a high print quality is attained for printing plastic cards or mats as well. A plate-like, rigid printing medium of this type is described in German Application No. DE 20 2006 005 458 U1. 
     The printing media such as plastic cards or mats are located in the printer in a stack, one atop the other, and must be separated before printing. This can take place in a separate separating device arranged ahead of the printer, or the printer may be equipped with a separating device. 
     However, in the previously known separating devices, especially metal components are moved against a stop to establish an end position. In this process, the components hit the stop without prior deceleration, frequently leading to development of noise. In addition, the components become eroded by the high mechanical stress. 
     The use of damping systems in printers of the class mentioned is very complicated. For example, the maintenance effort is very high in the case of hydraulically operating damping systems. The use of elastic materials for damping causes the drawback that the elasticity of the materials means that exact positioning of the components can no longer be guaranteed. In addition, such components can harden over time and thus lose their damping effect. 
     SUMMARY OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide a printing apparatus on a vertical stack of horizontal vertically-spaced planar objects arranged in a housing, including a separating arrangement for removing the lowermost object from the stack, and a printing device for printing information on the removed object. 
     According to a more specific object, the stack is supported in the housing by a plurality of support arrangements each including a support member mounted for reciprocatory horizontal displacement by an electromagnetic drive device between positions that are adjacent and remote from the stack, respectively. Each support member is guided during this displacement by a guide arrangement including at least one guide lever having a first end pivotally connected with the housing, and a second end connected with a guide follower roller that is in engagement with a guide cam surface carried by the support member. A row of horizontal support pins extends from the support plate into the vertical zone defined by the stack. In one embodiment of the invention, two guide levers are provided that are connected by a connecting rod, thereby to provide a parallelogram-type guidance system. In another embodiment, a single guide lever is utilized in conjunction with a stationary guide track and roller arrangement. This separating and printing operation is achieved in a relatively noise-free manner, since the components are guided against hitting one another. 
     According to a further object, a printing apparatus is provided for a plate-like printing medium, especially a card or a mat with a label or several labels for labeling electrical devices, connectors, cables, or the like, which are stacked in a stack, including a separating device for separating a printing medium from the stack, and a printing device. This separating device is designed such that it has at least one drive element with a support component that is provided with at least one guide cam for a follower device for moving the support component between a starting position remote from the stack and an end position adjacent the stack. The follower device is guided along the guiding curve by means of a pivot lever construction. The guiding of the follower along the guide cam ensures that the support component, especially a plate or a component of different dimensions, can be positioned accurately in both the starting and ending positions, and at the same time, the production of high noise is avoided. The end position, as a dead point, is approached without noise, since the follower s permanently lies against the support component. The dead point is defined as the position at which no further movement occur. 
     Advantageously the guide cam is designed as a longitudinal side wall of a slot defined in the support element, since this is easy to produce by industrial manufacturing processes and permits accurate guidance of the support component, for example a plate. 
     Also advantageously the follower member is designed as a deflecting roller, since this can be moved along the guide cam without great frictional losses. More particularly, the roller is guided along the guide cam by means of a linkage arrangement. According to a first embodiment of the invention, this is designed as a four joint linkage construction, which consists of at least two first joint axes or points arranged on counter-bearings, at which in each case a hinged bracket is connected with the stop means, and two second joint axes or points at the ends of the joint lever for coupling with a connecting rod. 
     In the area of each of the second joint axes or points a follower roller is provided, which is guided along the guide cam. This design permits positive guidance of the follower roller along the guide cam. 
     In addition, the follower roller is provided with a biasing spring for the positive return guiding of the plate from the end position, in which no movement takes place. 
     In a preferred embodiment, the plate is connected to a magnetic armature that is withdrawn into an electromagnet. For gentle return control of the magnet armature, the electromagnet is advantageously connected by a switch to an RC circuit. 
     According to another object, a separating device is provided for a plate-like printing medium stacked in a stack, especially cards or labels for labeling electrical devices, connectors, cables, or the like, for separating the printing medium from the stack. The separating device has at least one drive element with at least one support component that is provided with at least one guide cam for a follower device for the movement between a start position and an end position. The follower is guided along the guide cam by means of an articulated linkage construction. 
     Finally, according to another object, a device is provided for moving a component between two positions, wherein the component is equipped with at least one guiding curve for a follower device for the movement of the support component between a start position and an end position (preferably approachable as a dead point). The follower device is guided along the guide cam by means of a linkage construction. Preferably each pivot axis of rotation is located at a 90° angle with the direction of movement of the component (guided mass). Even before the mass is set into motion, the stop is adjacent to the mass and maintains the contact permanently, so that no components hit one another upon reaching the end position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention will become apparent from a study of the following specification, when viewed in the light of the accompanying drawing, in which: 
         FIG. 1  is a diagrammatic sectional view of the printing apparatus of the present invention; 
         FIGS. 2 a -2 d    are diagrammatic views illustrating the steps for operating the support members during the separation of the lowermost object of a stack; 
         FIGS. 3 and 4  are diagrammatic views illustrating a first two-lever parallelogram-type embodiment of the invention when in the de-energized extended and energized retracted positions, respectively; 
         FIG. 5  is a voltage diagram illustrating the dampening operation of the resistance-capacitance circuit of  FIGS. 3 and 4 ; and 
         FIGS. 6 and 7  are diagrammatic views illustrating the operation of a second single-lever embodiment of the invention when in the de-energized extended and energized retracted conditions, respectively. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first more particularly to  FIG. 1 , a printing apparatus  100  is disclosed including a housing H. containing a chamber C in which is supported a vertical stack  102  of horizontal planar objects  101  separated by permanent or removable spacer elements  110  ( FIG. 2 ). The printer  100  is preferably an ink jet printer for plate-type printing media, such as cards or labels on a mat. However, another printer type may also be involved. These printing media  101 , such as cards or mats with at least one label, have quite a high material strength and are usually made of plastic. Separating means  103  are provided for separating the lowermost object from the stack, which object is then transported by endless conveyor belt  107  to printing means  104  which prints selected information on the object. The printer  100  is preferably an ink jet printer for plate-type printing media, such as cards or labels on a mat. However, another printer type may also be involved. These printing media  101 , such as cards or mats with at least one label, have quite a high material strength and are usually made of a synthetic plastic material. In the event that the object  101  is formed from a thermosetting synthetic plastic material, it is then transported to a thermal fixing station  105 . The ink or the like is heat-fixed on the printing medium  101  by the drying device  105 . After all process steps are complete, the printed card  101  is subsequently discharged outwardly of the housing chamber via an outlet opening contained in the end wall thereof. If removable, the spacer elements  110  could be from the object then, or at a later time. 
     Referring now to  FIG. 2 a   , it will be seen that the horizontal planar objects  101  of the stack are vertically spaced by permanent or removable spacer elements  110 , with the lowermost object  101   a  of the stack being initially in engagement with an upper pair of opposed support pin arrangements  106   a . When these two upper support pin arrangements are relatively quickly withdrawn from the stack as shown in  FIG. 2 b   , the stack drops by gravity with the lowermost object  101   a  coming into engagement with the lower pair of opposed support pin arrangements  106   b , with the stack now being supported by these lower pin members. The upper two support pin arrangements  106   a  are now relatively slowly reinserted into the stack as shown in  FIG. 2 c   , whereupon the lower two support pin arrangements  106   b  are relatively quickly separated. The lowermost object  101   a  then drops by gravity from the stack onto the endless conveyor belt  107  as shown in  FIG. 2 d   , with the remaining objects of the stack being supported by the upper two support pin arrangements  106   a . The removed object  101   a  is then transported to the printer  104  by the endless conveyor  107 , and the bottom row of pins  106   b  is then moved back into its first position so that the next card  101   b  can be separated. 
     According to a first embodiment illustrated in  FIG. 3 , the separating means of the present invention comprises at least four separating arrangements  1 , each of which can be moved back and forth between a start position and an end position to separate a lowermost card from the stack, as is further shown in  FIG. 2 . Each separating arrangement includes a horizontal support plate  2  that is mounted for horizontal sliding movement within the housing chamber toward and away from the stack  102  by electromagnetic motor means including a stationary electromagnet  16  fixed to the housing, and a movable armature  15  having a free end connected with the support plate. The support plate carries  2  a row of horizontal parallel support pins  3  that are arranged to extend into the stack when the electromagnetic motor is in the de-energized condition shown in  FIG. 3 , with the support plate being adjacent the stack. A pair of armature biasing springs  18  and  19  are connected at their adjacent ends with the armature, and at their remote ends  20  and  21  with the housing, which springs bias the movable armature toward the illustrated extended position relative to the stationary electromagnet  16 . 
     The support plate  2  is guided during its horizontal movement relative to the stack by guide means including a pair of guide levers  8  and  9  that are pivotally connected at first ends by pivot axes  6  and  7  to the housing fixed supports  60  and  70 , respectively. The second ends of the guide levers are pivotally connected by pivot axes  80  and  90  with the ends of a connecting rod  12 , thereby to define a parallelogram-type linkage. The pivot axes of rotation of the linkage construction are at right angles to the direction of motion of the guided component (here a plate). Also connected with the lever second ends are rotatable follower rollers  10  and  11  that extend into guide slots  4  and  5 , respectively, contained in the support plate  2 . The opposed walls  140 ,  141  and  150 ,  151  of these slots define guide cam surfaces that are engaged by the rollers  10  and  11  respectively. It should be noted that the guide cam surface according to the invention can be understood not only as being linear, but also as a curved rolling path. Advantageously the rollers  10 ,  11  are supported so as to roll without large frictional losses along the guiding curve  140 ,  150  formed as the longitudinal sides of the slots. A linkage biasing spring  13  is connected at one end with the pivot axis  80  of the connecting rod  12 , and at the other end with the fixed housing location  14 . This linkage spring biases the connecting rod to the left to prevent the linkage from being locked up when the levers  8  and  9  are in the extended position of  FIG. 4 . 
     The electromagnet  16  of  FIG. 3  includes a coil that is energized via an operating circuit  23  including a pair of input terminals  24 , and a parallel branch containing a resistor R and a capacitor C. When a direct-current voltage V is applied across the input terminals  24  as shown in  FIG. 4 , the electromagnet  16  is energized, and the armature  15  is quickly withdrawn into the coil of the electromagnet, against the restoring force of the tension springs  18  and  19 . This movement of the armature quickly displaces the support plate  2  and the row of support pins  3  away from the stack, with the movement of the support plate being guided by the counterclockwise movement of the levers  8  and  9 , and the engagement of the rollers  10  and  11  with the cam surfaces  140  and  150 , respectively. When the supply of the direct-current supply voltage is interrupted, the linkage spring  13  biases connecting rod  12  to the left to prevent locking-up of the linkage, and the armature springs  18  and  19  cause the armature  15  to be returned to the extended position of  FIG. 3 , whereby the support plate is displaced toward its  FIG. 3  position adjacent the stack. Owing to the discharge effect of the capacitor C, this return action of the support plate is dampened and relatively slow, owing to the discharging of the capacitor, as shown by the capacitor discharge curve Uc of  FIG. 5 . 
     It is important to note that as a result of the plunging of the magnet armature  15  into the electromagnet  16 , its tensile force acts on the plate  2 . This exerts a reactive force on the rollers  10 ,  11  in such a manner that the articulated levers  8 ,  9  of the linkage perform a pivoting movement, which leads to a sliding movement of the deflecting rollers  10 ,  11  along the guide cam surfaces defined by the slots  4 ,  5 . Since the two deflecting rollers  10 ,  11  are coupled by the connecting rod  12 , guided movement of the plate  2  parallel to the housing wall takes place. The end position of the plate  2  is reached when the articulated rods  8 ,  9  are pivoted out in parallel to the direction of movement and thus the system has approached a dead point. At the end position both of the springs  18  and  19  are deflected and exert a restoring force on the magnet armature  15 . 
     When the application of direct current on the terminal clamps  24  is interrupted by the opening of a switch (not shown), the condenser C discharges over the series resistor R and the voltage U on the electromagnet  16  drops continuously. The voltage curve of the capacitor is shown in  FIG. 5 . As a result, the magnet armature  15  is not suddenly withdrawn from the coil of the electromagnet  16 , but instead a very gentle movement takes place. In addition the stopping of the plate  2  in its respective end position or dead point position as a result of guidance in the guide curves  140 ,  150  takes place with minimal momentum, or virtually momentum-free, and thus correspondingly with little or no noise, since the movable stop part is permanently attached to the moving mass and thus at no time do components hit one another. 
     When the voltage U on the electromagnet  16  decreases, the magnet armature  15  moves back out of the electromagnet  16  and the plate  2  with the pins  3  moves back to its start position. In this process a force is exerted on the stop  10  by the moving magnet armature  15  and also by the spring  13 ; this force drives the stop  10  from its end point back in the direction of the other side of the guiding curve  140 . As a result of the coupling of the stop  10  over the connecting rod  12  with the other stop  11 , this stop  11  also moves along the guiding curve  150 , and the articulated rods  8 , 9  undergo a pivoting motion, so that the plate  2 —and thus the separating pins  3  attached to it—returns to its start position. At this point the springs  18  and  19  are almost horizontally aligned and hold the rollers  10 ,  11  and the magnet armature  15  and the plate  2  in a defined start position. 
     Through the guidance of the rollers  10 ,  11  by means of a four joint construction in a guiding curve  140 ,  150  it is ensured that the plate  2  can be exactly positioned both in the start position and in the end position, since no components hit one another. In addition, high noise development is avoided, since as a result of a continuously decreasing voltage curve provided by the RC element, a soft movement of the four-joint construction back to the start position is made possible. In addition, the mechanical stress on the plate  2  can be distinctly reduced. 
     According to a second single-lever embodiment shown in  FIG. 6 , the support plate  30  is displaced toward and away from the stack of objects by the movable armature  39  of the electromagnetic motor means including stationary electromagnet  41 . For guidance, the support plate is provided with a single slot  33  having opposed side walls defining cam surfaces  301 ,  302 , and a single guide lever  35  that is connected at one end by pivot  34  with the housing fixed support  300 . Roller  36  is rotatably connected with the lever second end and extends into the slot  33 . Lever spring  37  connected between the lever second end and the fixed support  38  biases the lever to the left away from the illustrated pivot end position. To further guide the support plate, it is provided with a plurality of rollers  31  that ride on the stationary guide track  32  provided on the fixed housing, which guide is parallel with the direction of axial travel of the armature  39 . A support plate spring  42  connected between the support plate  30  and the fixed support connection  43  biases the armature  39  and the support plate  30  toward the extended positions shown in  FIG. 6 , wherein the support plate is adjacent the stack. 
     Upon energization of the electromagnet by the application of a direct-current voltage to the operating terminals as shown in  FIG. 7 , the armature  39  is quickly withdrawn into the electromagnet, the support plate  40  is displaced away from the stack, the tension spring  42  is expanded, and the guide lever  35  is pivoted in the counterclockwise direction about the pivot axis  34 . During this travel of the support plate, it is guided by the cooperation between the lever roller  36  and the cam surface  302  of slot  33 , and between the plate rollers  31  and the stationary guide track  32 . 
     Upon de-energization of the electromagnet, the armature  39  and the support plate  30  are returned by spring  42  to their positions of  FIG. 6 , with the support plate being adjacent the stack, and with the support pins (not shown) extending into the stack. If this arrangement were to be provided with the RC circuit of  FIGS. 3 and 4 , the support plate and the armature would be subjected to the slow-return capacitor-discharge dampening operation of  FIG. 5 . 
     In this embodiment, the articulated lever  35  describes a semicircular motion and reaches a second end position as a dead point, when the articulated lever  35  is in a parallel orientation relative to the track  32 . Since the maximum deflection of the plate  30  is determined by the semicircular motion of the articulated lever  35 , the length of the articulated lever  35  thus predetermines the travel distance of the plate  2 . In the first half of the path of the plate  30 , the roller  36  moves along the first longitudinal side  301  of the slot hole  33  until the articulated rod  35  has rotated through 90°. Then the other longitudinal side  302  of the slot hole  33  represents the guiding curve, and the stop means  36  moves along this curve  302 , so that the articulated lever  35  rotates through a further 90°. 
     As a result of the guidance of the roller  36  by a joint construction along a guiding curve  301 ,  302 , it is ensured that the plate  30  can be exactly positioned in both the start and end positions. Since the roller  36  is carried along during the movement of the component or the plate  30 , the component is braked abruptly, but it does not hit the end of a path of motion hard against an end stop. Instead, according to the invention the end point at the end of a guiding curve  301 ,  302  determines the end position of the stop means  36  in the manner of a dead point and thus determines the end position of the component or the plate  30 . 
     In the embodiment shown, movement of the roller  36  is provided along two guiding curves  301 ,  302  accomplished by the two longitudinal sides of the slot  33 . In this process in each case one guiding curve serves for one direction of movement. However, it is also conceivable that only one guiding curve  301  is provided and the articulated rod can then achieve an end position of the moving mass. 
     In addition, as a result of a continuously decreasing voltage curve provided by an RC element, here also a very soft movement of the joint construction back into the start position can be provided, which leads to a further reduction of noise production. Furthermore the mechanical stress on the plate  30  can be reduced distinctly. 
     In a further development of the invention it is possible to produce the dimensions of the plate with the stop means such that it can be placed inside of an electromagnet. 
     While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes may be made without deviating from the invention described above.