Patent Publication Number: US-8974133-B2

Title: Dispensing device with an electric motor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY 
     This application relates to German Application No. 20 2010 001 508.1 filed Jan. 28, 2010 and German Application No. 20 2010 011 769.0 filed Aug. 24, 2010, of which the disclosures are incorporated herein by reference and to which priority is claimed. 
     The present invention relates to a dispensing device for dispensing glue or adhesive in the width of the elements to be laid onto an area for the laying of floor coverings, in particular parquet or laminate inboard format, comprising a glue cylinder into which at least one pouch filled with glue or adhesive can be inserted, and comprising a plunger which is disposed displaceably and with axial movement within the glue cylinder so as to compress a pouch located within the glue cylinder and so to push its contents out of the glue cylinder. Furthermore, the present invention relates to a dispensing bar for dispensing glue or adhesive, in particular onto a substrate surface, in the width of floor coverings to be laid in board formats, comprising a base element on which at least one delivery opening and a number of dispensing openings are formed arranged lying next to one another, and in particular opposite the delivery opening. 
     These types of dispensing device are already sufficiently well known from the prior art, and are described, for example, in European Patent Application EP 1 439 009 A1. The device known from this publication includes two glue cylinders which serve to accommodate pouches filled with glue or adhesive. Disposed respectively in the glue cylinders is a plunger that can be moved by means of compressed air in order to compress the pouch located within the glue cylinder and so press its contents out of the pouches and deliver it by means of access openings of a dispensing bar. In order to deliver and distribute the glue, discrete channels coming off of the delivery opening are formed in the dispensing bar which open out into outlet openings formed on the dispensing bar opposite the delivery opening. 
     It is a disadvantage with the known prior art that it is expensive to produce these dispensing bars. Cleaning after dispensing glue is also complex and so costly. If a dispensing bar is not cleaned sufficiently thoroughly after use there is a risk that individual dispensing openings of the dispensing bar will become clogged up. The result can be inhomogeneous glue or adhesive dispensing which can lead to uneven distribution of the glue or adhesive over the surface of the object to be glued. 
     It is a further disadvantage of the known dispensing bar that the dispensing width is also already determined when producing the bar. Therefore, in particular from aspects relating to handling and for a reproduceable, even working result for every board width a particular, very costly dispensing bar may be required. 
     The delivery of glue and adhesive by means of compressed air is not unproblematic either. On the one hand the measures to be taken in order to deliver the compressed air precisely through the dispensing device without the risk of leakage points occurring are very complex. On the other hand, control of the amount dispensed and the dispensing speed with which the glue or adhesive moves out of a dispensing bar adjoining the glue cylinder also proves to be difficult. 
     It is therefore the object of the present invention to provide a dispensing device and a dispensing bar which have a simple structural design and enable simple and precise handling of the glue or adhesive dispensing. 
     This object is initially achieved according to the invention with a dispensing device in that an electric drive is provided which is coupled to the plunger in order to displace the plunger axially. 
     By providing an electric drive the sealing measures required with a pneumatic drive can be dispensed with. Control of the dispensing quantity and speed can also be implemented simply by controlling the rotational speed of an electric motor disposed in the electric drive. 
     In one exemplary embodiment of the present invention the plunger is connected to a toothed rack guided with axial moveability, which extends into the glue cylinder and is coupled to an output shaft of the electric drive so that rotation of the output shaft is converted into movement in a straight line of the toothed rack. 
     It can be advantageous that the electric drive has a gearing mechanism, in particular planetary gearing, which engages with the toothed rack in order to convert rotatory movement of the electric drive into a straight line movement of the toothed rack. In this way homogeneous and smooth movement of the toothed rack and so of the plunger, is made possible, and this aids even dispensing of the glue or adhesive. 
     Particularly simple handling and refillability of the dispensing device is provided if the gears can be switched manually between an operating position, in which they engage with the toothed rack, and a filling position, in which free axial movement of the toothed rack within the planetary gears of the electric drive is possible. In the filling position, by means of the free axial movement of the toothed rack the latter, and so also the plunger, can be brought particularly quickly into an initial position in which filling of the glue cylinder is possible. 
     In order to stabilise the toothed rack disposed in the dispensing device, in a further exemplary embodiment stabilising means are provided on the toothed rack by means of which the toothed rack can be supported on a wall of the glue cylinder in order to counter bending of the toothed rack due, for example, to bending moments acting on the toothed rack. 
     For this purpose the stabilising means can be formed, for example, by cylinder discs moveable along the toothed rack. 
     In order to guarantee that the stabilising means are also distributed as evenly as possible over the extension of the toothed rack with a moveable arrangement, in one exemplary embodiment spacer elements are provided between the stabilising means for holding the stabilising means equidistantly along the toothed rack. 
     The spacer elements can be formed, for example, by spring elements, in particular by spiral springs, which are supported between the stabilising means. 
     Particularly simple control is produced by an operator if the electric drive has actuating means which when actuated by a user enable the rotational speed and/or the direction of rotation of an electric motor used in the electric drive to be set. The actuating means can be designed such that it enables graduated setting of the rotational speed. 
     Alternatively, an infinitely variable change to the rotational speed can also be provided by a corresponding design of the actuating means. 
     In order to provide simple and flexible use of the dispensing device, in one exemplary embodiment of the present invention the electric drive is provided with an accumulator which supplies the electric motor of the electric drive with current. 
     In the electric drive a control can be provided which limits the current consumption of the electric motor. If, therefore, a load to be overcome by the electric motor becomes too big to move on the toothed rack, for example because the axial movement of the toothed rack is blocked, upon reaching a settable maximum current consumption which correlates approximately to the load to be applied, further current consumption is blocked by the control in order to prevent bending of the toothed rack due to the loads acting on it from feed motion and axial blockade. 
     Particularly flexible usability of the dispensing device according to the invention is produced if a dispensing bar adjoining the glue cylinder is attached interchangeably to the glue cylinder. A dispensing width of the dispensing device and so adaptation of the latter to the floor covering to be glued is thus made possible simply by interchanging the dispensing bar. 
     In order to simplify the positioning and guiding of the dispensing device, in one exemplary embodiment at least one stop bar is provided on the dispensing bar by means of which the dispensing device can be positioned and guided on the substrate and/or a wall and/or an edge region of parquet or laminate boards already laid. 
     An alternative or additional possibility for adapting the dispensing width of the adhesive can be provided by dispensing openings being provided on the dispensing bar which in order to set a dispensing width can be temporarily closed by inserts, in particular flat headed screws. 
     The object is further achieved according to the invention with a dispensing bar in that the base element is formed by a tube the axial end regions of which are closed, and in that positioning aids in the form of stop bars are provided at the edge regions of the tube. 
     With the dispensing bar according to the invention the base element is formed by a simple tubular element. The conveyance of the glue from the delivery opening to the surface of the object to be glued no longer takes place through discrete channels. Instead, the glue initially collects within the tube and passes directly from the latter via the dispensing openings onto the component to be glued. The design of the cross-sectional areas of the outlet openings formed in the base element thus determines the form and quantity of the glue or adhesive on the glued surface. For example, the glue can be dispensed onto the object to be glued in the form of round, star-shaped or square strands of glue or adhesive. 
     By means of the simple structural design the dispensing bar according to the invention can be produced inexpensively. Depending on the choice of material for the dispensing bar the latter can even be in the form of a throw-away part. For example, the tube can be produced from plastic, in particular from PVC. Due to the simple and inexpensive production it is also possible from a financial point of view and also wise in view of the associated saving of time when handling the device to use for objects with glued surfaces with different widths a respective dispensing bar with a base element adapted to this width. 
     In order to also be able to use the dispensing bar universally in already existing glue or adhesive dispensing devices, with the dispensing bar according to the invention it is only necessary to adapt the delivery opening to the respective connection configuration of the device already available on the market. It is then possible to use the dispensing bar with any glue dispensing device (dispenser) available on the market and also to retrofit it appropriately. 
     When dispensing the glue or adhesive onto an already laid floorboard the stop bars serve to be brought to rest, and on said board to be moved along, and this contributes to a reproduceable dispensing result and a homogeneous dispensing appearance. Here the stop bars project downwards over the tube so that they form spacing relative to the substrate to be worked on. This embodiment makes it possible to place the dispensing bar on the floor and to bring it to rest against the floor board laterally with the result that it is extremely easy to use the device for dispensing glue. 
     Preferably a bent metal sheet—in particular U-shaped—can be provided that extends over the tube and has arms projecting laterally downwards from the tube forming the stop bars. 
     For homogeneous distribution of the glue or adhesive in the space enclosed by the tube a number of delivery openings can be formed on the tube. 
     The base element can have a round or square, in particular quadratic or also an elliptical cross-section in order to be adapted to the geometry of the area provided with adhesive or glue and to be able to lie on the glued surface to be assembled for example. 
     In one exemplary embodiment the tube is formed from a number of tube sections interlocking like a telescope which are connected to one another, displaceably in relation to one another, in order to set the dispensing width of the adhesive or the glue. With this embodiment the width of the dispensing bar can be adapted to the width of an object to be glued. In order to be able to guarantee homogeneous dispensing of the glue or adhesive when the tube sections are shifted relative to one another, in a further configuration of this embodiment a grating can be provided on the tube sections. By means of the latter it is achieved that after shifting the tube sections always adopt a position in which the outlet openings lie over one another in a crossover region of the tube sections, and so remain penetrable over the whole extension of the tube. 
     It has proven to be particularly advantageous if the width of the tube of a dispensing surface of the component to be glued corresponds in particular to a floor board to be glued. If in addition the dispensing openings and the distances between them are also adapted to the different widths of the adhesive dispensing surfaces and different parquet board widths, a particularly homogeneous adhesive application is achieved. Also the dispensing openings can not only be disposed next to one another, but also in a number of rows so as to enable faster and specific material application onto the glued surface. 
     In one embodiment of the invention the axial end regions are closed by means of caps. These caps can be designed such that they project radially from the tube and so form a spacer in relation to the substrate being worked on. The caps then form the stop bars. 
     According to one preferred embodiment provision is made such that at least one cap is fixed rotatably onto the tube and has an extension, which is likewise tubular, projecting into the tube, the extension having wall regions which by turning the cap can be brought to overlap the dispensing openings so as to thus reduce the dispensing width. With this embodiment, depending on the rotational position, the cap covers a different number of dispensing openings so that the dispensing width can be set by turning the cap. 
     With a variation of the embodiment the extension can overlap a predetermined number of dispensing openings and have openings in the extension corresponding to the dispensing openings. Preferably a number of rows of openings are provided here in the extension, the number of which preferably decreases from one row to the next from the outside to the inside. With this embodiment the user sets the dispensing width before placing in operation the dispensing bar by overlapping a desired number of openings in the extension with the dispensing openings by turning the extension. 
     Alternatively, the tubular extension can also be cut off at an angle so that its extent is of variable length. In this case the cap is turned before placing in operation to such an extent that the desired number of dispensing openings are covered. 
    
    
     
       Further advantageous embodiments of the present invention can be gathered from the sub-claims or from the drawings described below. These show as follows: 
         FIGS. 1   a  and  1   b  a diagrammatic illustration of a dispensing device according to the invention for dispensing glue or adhesive onto a substrate surface; 
         FIG. 2  a perspective exploded drawing of the dispensing device according to the invention according to  FIG. 1 ; 
         FIG. 3  a diagrammatic illustration of the dispensing device according to the invention in operation; 
         FIG. 4  a diagrammatic illustration of a glue dis-pensing device with a dispensing bar according to the invention; 
         FIG. 5  the glue dispensing device according to  FIG. 4  from the right; and 
         FIG. 6  an enlarged partial illustration of the glue dispensing device with two caps. 
     
    
    
       FIGS. 1   a  and  1   b  show a diagrammatic illustration of a dispensing device  1  for dispensing glue or adhesive for laying or gluing floor coverings, in particular parquet or laminate in board format. 
     The dispensing device  1  is designed as a free-standing device and has a glue cylinder  103  into which a pouch  3  filled with glue or adhesive is inserted. Adjoining the free end of the glue cylinder—shown on the left in the drawing—is a dispensing bar  102  which is connected to the glue cylinder  2  via a delivery opening  108 . The dispensing bar  102  has a base element  107  which has a number of dispensing openings  108  lying next to one another opposite the delivery opening  108 . In the exemplary embodiment shown the base element  107  is in the form of a cylindrical tube made of plastic, the axial end regions of which are closed by caps  113 . A respective positioning aid in the form of stop bars  111  is respectively provided at the end regions of the base element  107 . The stop bars  111  are formed here on a bent metal sheet which is pushed onto the glue cylinder  103  via the delivery opening  108  and is screwed to the base element  107  of the dispensing bar  102 . 
     The interchangeability of the dispensing bar  102  makes it possible to unscrew the dispensing bar  102  with different widths of parquet board for dispensing the adhesive and to replace it with a further dispensing bar  102  with a correspondingly shorter or longer base element  107 . Alternatively, it is also possible to provide adaptation of the working width to the width of the parquet boards by temporarily closing individual outlet holes or dispensing openings  109  of the dispensing bar  102  with inserted flat headed screws. 
     Disposed on the end of the glue cylinder  103  lying opposite the dispensing bar  102  is an electric drive  9  which—as also illustrated in greater detail in FIG.  107 —is coupled to an axially moveable plunger  10  disposed in the glue cylinder  2  in order to displace the plunger  10  axially within the glue cylinder  2 . The plunger  10  is connected to a toothed rack  11  which extends into the glue cylinder  103  and is guided therein with axial moveability. The toothed rack  11  is coupled to an output shaft (not shown) of the electric drive  9  so that rotation of the output shaft driven by the electric motor is converted into a straight-line axial movement of the toothed rack  11  and the plunger  10 . 
     The toothed rack  11  is connected to a gear mechanism (not detailed) of the electric drive  9 . The free end of the toothed rack  11  projects out of a housing  12  surrounding the electric drive  9 . The length of the section of the toothed rack  11  projecting out of the housing  12  shows a user the amount of glue or adhesive remaining in the glue cylinder. 
     The length of the toothed rack  11  is designed, as shown in  FIG. 1   b , such that after reducing the dispensing bar  102  by using an actuating means  13  formed on the housing  12  of the electric drive  9 , and so by pushing the toothed rack  11  and the plunger  10  further forward, the squeezed pouch  3  can be pushed out of the glue cylinder  103  without a user having to take hold of the pouch  3 . 
     A rotational speed of the electric motor for moving the toothed rack  11  is set by the actuating means  13 . In this way the delivery rate of the glue or adhesive can be adapted to the prevailing operating conditions. 
     The supply of power to the electric motor of the electric drive  9  is implemented by means of an accumulator  14  connected to the electric motor and fitted in the housing  12 . In order to simplify handling the housing  12  of the electric drive  9  is designed in the form of a handle. A further handle element  15  is optionally fastened to the glue cylinder  103  substantially centrally. 
     In order to stabilise the movement of the toothed rack  11  within the dispensing device  1 , in this exemplary embodiment stabilising means  16  in the form of cylinder discs are provided by means of which the toothed rack  11  can be supported on the wall of the glue cylinder  103 . The cylinder discs  16  are attached to the toothed rack  11  with axial movement. 
     In order to further stabilise the toothed rack  11  spacer elements are provided between the stabilising means  16  in order to hold the stabilising means  16  equidistantly along the toothed rack  11 . In the present exemplary embodiment the spacer elements are formed by spiral springs  17  which extend axially along the glue cylinder  103 . 
     As a further measure for preventing bending of the toothed rack  11   a  control is provided in the electric drive  9  which limits the current consumption of the electric motor. In this way overloading of the toothed rack  11 , the stabilising means  16  and the electric motor is ruled out and the energy yield from the accumulator  14  is maximised. 
     The gear mechanism provided in the electric drive  9  is in the form of a planetary gear and a flange-mounted angular gear which can be switched manually between an operating position, in which it engages with the toothed rack  11 , and a filling position, in which a free axial movement of the toothed rack  11  within the electric drive  9  contrary to the dispensing direction of the glue or adhesive is possible. 
     Alternatively, it is also possible to switch the gear into a filling position such that it finds itself in a type of idling state if the toothed rack  11  is then drawn manually by means of a filling lever  18  formed on the free end of the toothed rack  11  without expending any great force into a position in which the piston  10  with the glue cylinder  103  comes to rest against its end facing towards the electric drive  9  so as to thus clear the space required for refilling the glue cylinder  103  with a further pouch loaded with glue or adhesive. 
       FIG. 3  shows a dispensing device  1  according to the invention in operation. The length of the dispensing device  1  in the form of a free-standing device is approx. 115 cm and is chosen such that it enables fatigue-free working and at the same time in the packaged state fits onto a euro-pallet. 
     In order to enable the most accurate possible positioning and the straightest and most even possible dispensing of beads of adhesive  19  from the openings of the dispensing bar the stop bar  111  is brought by a user to rest against a wall, or as shown here, against an edge  20   a  of strips of parquet board  10  already laid or on the substrate or floor to be worked on, and during dispensing of the adhesive is drawn along the edge  20   a  formed by the wall or board strip and the substrate. 
     By pressing the actuating means  13  the adhesive is distributed in uniform adhesive beads over the substrate. By means of the actuating means  13  the delivery quantity and delivery speed of the adhesive beads  19  can be varied. If therefore the adhesive beads  19  are distributed not in a straight line but in a meandering form on the substrate, either the delivery output can be reduced by the regulator  13  or the feed speed of the dispensing device  1  can be increased which can be achieved, for example, by faster walking. 
       FIGS. 4 and 5  show a diagrammatic illustration of a further glue dispensing device  100  for dispensing glue or adhesive to an object to be glued such as for example parquet or laminate boards. The glue dispensing device  100  comprises a dispensing bar  102 , a glue cylinder  103  and a compressed air delivery device  104  which can be controlled by means of an actuation lever  106  which is provided on a handle  105  fitted onto the glue cylinder  103 . 
     The dispensing bar  102  has a base element  107  on which a delivery opening  108  and a number of dispensing openings  109  lying next to one another and opposite the delivery opening  108  are formed (see also  FIG. 5 ). In one exemplary embodiment (not shown) the dispensing openings  109  are disposed at an angle of 30°, 45° or 60° relative to the axis formed by a glue cylinder  103 . 
     In the exemplary embodiment shown the base element  107  is designed in the form of a cylindrical tube made of plastic, in this case PVC, the axial end regions  110  of which are closed by caps  113 . The width of the tube  107  is chosen here such that it corresponds to the width of the object to be glued. 
     A respective positioning aid in the form of a stop bar  111  is provided at the end regions  110  of the tube  107 . The stop bars  111  are formed here by a bent metal sheet which is pushed onto the glue cylinder  103  by means of a connection nozzle  112  and screwed onto the dispensing bar  102 . More specifically, a U-shaped bent metal sheet is provided which extends over the tube  107  and has arms projecting laterally downwards from the tube  107  forming the stop bars  111 . As can be seen in particular in  FIG. 4  the arms project downwards over the tube  107  in order to form spacing relative to the substrate to be worked on. The arms have on their lower end region a rounded, in this case semi-circle-like form (see  FIG. 3 ). 
     By means of the stop boards  111  it is possible to dispense the glue or adhesive with precise positioning and evenly. For this purpose the dispensing bar  102  is placed on the floor with its stop bar  111  and laid against a wall or against a floor board already laid and guided along the latter. 
     The quantity of glue flowing out is determined and controlled here by the size and number of dispensing openings  109 , the speed of movement of the device  101  over the surface of the object to be glued and to be assembled along the already laid floor boards and the system pressure applied by the compressed air delivery device  104 , among other things dependently upon the viscosity of the adhesive. 
     The glue cylinder  103  serves to accommodate glue pouches (not shown) in which the glue or adhesive to be applied is stored. In order to apply glue or adhesive the glue pouch is first of all inserted into the glue cylinder such that the glue can flow out of the glue pouch via an outlet opening  112  formed on the glue cylinder  103  into the delivery opening  108  formed in the dispensing bar  102 . The dispensing of the glue from the glue pouch from the outlet opening  112  via the delivery opening  108  into the interior of the tube  107  can be implemented, for example, by means of a plunger (not shown) which successively compresses the glue pouch by means of compressed air from the compressed air delivery device  104  (not shown). 
     If the interior of the tube  107  is totally filled with glue, further delivery of the glue from the glue pouch ensures that the glue passes automatically homogeneously out of the dispensing openings  109  of the tube  107  onto the object to be glued according to the width of the tube  107  and the arrangement of the dispensing openings  109  disposed therein. 
       FIG. 6  shows an enlarged partial illustration of an alternative dispensing bar for a glue dispensing device  101 . With this embodiment the axial ends of the tube  107  are closed by two caps  113 . The latter project radially in relation to the tube diameter  107  and so guarantee a predetermined distance from the substrate to which the glue is to be applied. At the same time the outer face surfaces form the stops on the cap side by means of which the dispensing bar  102  can be positioned laterally. 
     As can be seen easily in  FIG. 6  the caps  113  respectively have an extension  113   a ,  113   b , also tubular in form, projecting into the tube  107 , the extensions  113   a ,  113   b  having wall regions which by turning the cap  113  are brought to overlap with the dispensing openings  109  so as to thus reduce the dispensing width. For this purpose, in a simple way the extension  113   a  of the cap  113  on the left in the drawing is cut off at an angle, the position shown defining the maximum dispensing width, whereas with a cap  113  turned about 180° the extension  113   a  covers the maximum possible number of dispensing openings  109 . 
     With the cap  113  on the right in the drawing the extension  113   b  has a length that is constant over its extent. For this purpose a number of rows of openings  114  are provided in the extension  113   b , the number of openings  114  decreasing from one row to the next from the outside to the inside. In the position shown the maximum possible number of dispensing openings  109  are covered by the extension  113   b . By turning in an anticlockwise direction the dispensing width is continuously increased.