Abstract:
An apparatus for applying fluid from a fluid source to a substrate. The apparatus comprises a housing configured to receive the fluid from the fluid source, a nozzle arrangement in fluid communication with the housing, and a lever pivotally mounted to the housing for releasably securing the nozzle arrangement thereto.

Description:
TECHNICAL FIELD  
       [0001]     The invention concerns an apparatus for applying fluid comprising housing and an associated applicator nozzle arrangement releasably secured thereto.  
       BACKGROUND  
       [0002]     Apparatuses which include applicator heads, applicator nozzle arrangements, adaptor plates and/or mounting plates are used in various sectors of industry in order to continuously or intermittently apply different materials which are capable of flow. For example, adhesives, lacquers, and coating materials are applied to hygiene articles, wood products, machine parts, and bodywork parts of vehicles or the like, in bead form, line form, point form or over an area.  
         [0003]     For that purpose the applicator nozzle arrangements and applicator heads are connected to a fluid source, for example, an adhesive container, from which the fluid may be conveyed by a pump through a feed passage to the applicator nozzle arrangement. The flow of fluid can be interrupted or enabled, such as by a valve arrangement which is connected into the feed passage. When the valve is in the open condition the fluid then flows through a discharge passage in the applicator nozzle arrangement. The passage communicates with a discharge opening for delivery of the fluid, from which the fluid then issues under pressure and then passes on to the substrate which is movable, for example, by a conveyor device relative to the discharge opening and thus relative to the applicator nozzle arrangement. When the fluid is being applied the applicator nozzle arrangement can be in contact with the substrate (contact type). In other embodiments, the applicator nozzle arrangement maintains a spacing between itself and the substrate (non-contact type).  
         [0004]     Such applicator heads and applicator nozzle arrangements are known, for example, from PCT/EP00/04137 to the present applicants.  
         [0005]     In order to maintain, repair or replace the applicator head and/or the applicator nozzle arrangement in the state of the art, it is necessary to release the large number of fixing screws which connect the applicator nozzle arrangement to the applicator head, such screws generally being difficult to access by virtue of the geometry of the machine. That procedure needs tools, takes up time and from time to time requires skill on the part of the fitter. In addition, after the mounting operation, it is necessary to check for correct positioning of the applicator nozzle arrangement which has possibly altered during the mounting procedure, and that is complicated and expensive.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention provides an apparatus, or applicator head, for applying fluid from a fluid source to a substrate. The apparatus comprises a housing configured to receive fluid from the fluid source, a nozzle arrangement in fluid communication with the housing, and a lever pivotally mounted to the housing for releasably securing the nozzle arrangement thereto. The nozzle arrangement includes a discharge passage applying the fluid to the substrate.  
         [0007]     An advantage of the invention is that no tool is necessary for replacing the applicator nozzle arrangement. This permits the applicator nozzle arrangement to be quickly and inexpensively changed. A further advantage is that, in the event of a change of the applicator nozzle arrangement, it can be very easily and very precisely positioned. Because precise positioning is an important prerequisite for trouble-free operation of adhesive applicator apparatuses, the invention also reduces the error probability of such installations and thus enhances the availability thereof. Those advantages are achieved by the lever according to the invention.  
         [0008]     By virtue of the fact that it is possible to forego the use of tools for replacing the applicator nozzle arrangement, there is also no longer any need, in terms of the design structure, to take account of the fact that sufficient space is kept free for the use of a tool. In this respect, the specified advantages can be achieved by means of a simple and thus inexpensive structure. In addition, existing applicator apparatuses can be easily retrofitted therewith.  
         [0009]     In a preferred embodiment of the invention the lever is mounted on the housing, or main body. In an installation for applying fluids to a movable substrate, a large number of various applicator nozzle arrangements per applicator head are usually kept on hand. The provision of the lever on the main body minimizes the number of levers required overall.  
         [0010]     It is preferable for the lever to be adapted to exert a force on the applicator nozzle arrangement, in which respect the force acts substantially parallel to the contact surface between the applicator nozzle arrangement and the main body. The fluid leaving the applicator head is applied to a generally movable substrate which moves along the applicator surface of the applicator nozzle arrangement. In order to prevent the substrate from being adversely affected by the applicator nozzle arrangement, it is advantageous if the latter has no openings whatsoever or other surface irregularities. The fact that the force exerted on the applicator nozzle arrangement by the lever acts parallel to the contact surface between the applicator nozzle arrangement and the main body avoids the lever having to engage into the surface which is proximate the substrate.  
         [0011]     It is preferred that a torque can be applied to the lever by an adjusting screw. Friction occurs at the areas of contact between the adjusting screw and the applicator head, and the adjusting screw and the lever respectively. That friction prevents the adjusting screw coming loose during operation so that the torque applied to the lever does not change during operation.  
         [0012]     It is particularly preferable for the adjusting screw to be arranged at the end of the lever, which is proximate the main body. This arrangement provides that the adjusting screw is at a great spacing from the pivot point of the lever so that a good lever ratio is achieved. This arrangement also means that the adjusting screw is disposed at a relatively large spacing from the possibly hot applicator nozzle arrangement. Alternatively the adjusting screw can be disposed on the same side as the applicator nozzle arrangement, as viewed from the mounting of the lever.  
         [0013]     In a preferred embodiment of the invention, the applicator nozzle arrangement and the lever engage each other in a positively locking relationship. This affords a particularly robust connection between the applicator nozzle arrangement and the applicator head. Even if the clamping force exerted by the lever slackens, the positively locking engagement ensures that the applicator nozzle arrangement cannot come loose from the applicator head.  
         [0014]     In a preferred embodiment of the invention, at its end in contact with the applicator nozzle arrangement, the lever has a portion with a convex and arcuate contour. A convex and arcuate contour provides an extended contact region between the lever and the applicator nozzle arrangement. Such a contour also has a positive effect on the levels of positioning accuracy which can be achieved.  
         [0015]     It is preferred that the main body has a support section against which the applicator nozzle arrangement can be pressed by the lever. The support section is configured to serve as an abutment such that it results in an increase in the level of positioning accuracy.  
         [0016]     It is particularly preferred in that respect for the concave structure to have a preferably flat guide surface which extends in such a way that the applicator nozzle arrangement is pressed against the main body by the action of the lever. That affords a secure clamping connection between the applicator nozzle arrangement and the main body.  
         [0017]     In a preferred embodiment, the applicator nozzle arrangement is guided linearly between the support section and the one end of the lever. In such an arrangement only the lever has to be released in order to change the applicator nozzle arrangement. The applicator nozzle arrangement can then be released from the applicator head by a translatory movement. The linear guidance also enhances the degree of positioning accuracy of the applicator nozzle arrangement relative to the applicator head.  
         [0018]     A preferred applicator nozzle arrangement is one which includes a concave recess extending along a narrow side and a convex projection extending along the narrow side which is in opposite relationship to said narrow side. Such an arrangement provides that the applicator nozzle arrangement can only be connected to the applicator head in one way, namely the correct way, and therefore excludes mounting errors.  
         [0019]     A particularly preferred applicator nozzle arrangement is one in which the convex projection is adapted for co-operating with a concave structure of the main body of an applicator head as described above. The co-operation of the convex projection with the concave structure affords a large contact surface area for the applicator nozzle arrangement on the applicator head so that this ensures a high level of positioning accuracy and a secure connection between the two.  
         [0020]     In a preferred embodiment, the applicator nozzle arrangement has an arresting member which limits a movement in a direction parallel to the contact surface of the main body and the applicator nozzle arrangement. The arresting member is formed in particular by a hollow pin in which a ball is subjected to a spring force such that a fraction of the ball projects beyond an end face of the hollow pin. In that respect, the term “movement” is only used to denote a movement of the applicator nozzle arrangement, such movement being guided by the main body, as occurs upon mounting of the applicator nozzle arrangement.  
         [0021]     The arresting member permits precise positioning and at the same time rapid mounting of the applicator nozzle arrangement on the applicator head. If the above-mentioned hollow pin is used and if the applicator nozzle arrangement is disposed in the correct position relative to the applicator head, then the spring-loaded ball in the hollow pin is urged further beyond the end of the hollow pin by the spring force, by an amount which is small relative to its diameter. In that situation the ball engages into a recess provided on the applicator nozzle arrangement so that the applicator nozzle arrangement and the applicator head are secured relative to each other.  
         [0022]     A preferred adaptor plate according to the invention is adapted for mounting to a main body of an above-described applicator head. The adaptor plate includes a concave recess extending along a narrow side and a convex projection extending along the narrow side which is in opposite relationship to said narrow side. Moreover, in a preferred embodiment of the adaptor plate the convex projection is adapted for co-operating with a concave structure of the main body of an applicator head. It is also desirable if the adaptor plate has an abutment, in particular a pin, which limits a movement in a direction parallel to the contact surface of the main body and the applicator nozzle arrangement.  
         [0023]     A particularly preferred adaptor plate is one which includes a recess for accommodating an elastic sealing element. Upon mounting of the applicator nozzle arrangement to the applicator head the elastic sealing arrangement is elastically deformed and thus prevents leakage flows of the fluid in the situation where the two components are not perfectly positioned relative to each other.  
         [0024]     A preferred mounting plate is one in which the lever is mounted to the main body. That permits rapid retro-fitment of applicator systems which hitherto operate with another clamping system.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]     An embodiment of the present invention is described hereinafter with reference to the drawings in which:  
         [0026]      FIG. 1  shows a perspective view of an applicator head, or apparatus, with a correspondingly associated, mounted applicator nozzle arrangement,  
         [0027]      FIG. 2  shows a side view of the applicator head and the associated applicator nozzle arrangement of  FIG. 1 ,  
         [0028]      FIG. 3  shows a perspective view of the applicator head and the applicator nozzle arrangement of  FIGS. 1 and 2 , in the separated condition,  
         [0029]      FIG. 4  shows a further perspective view of the components as shown in  FIG. 3 ,  
         [0030]      FIG. 5  shows a mounting plate,  
         [0031]      FIG. 6  shows an exploded view of the mounting plate of  FIG. 5 ,  
         [0032]      FIG. 7  shows a perspective view of a hollow pin for securing the applicator nozzle arrangement and the applicator head relative to each other, and  
         [0033]      FIG. 8  shows a further perspective view of the components as shown in  FIG. 3 , with the hollow pin shown in  FIG. 7 . 
     
    
     DETAILED DESCRIPTION  
       [0034]      FIG. 1  shows an applicator head  10 , or apparatus  10 , which has a main body  12 , or housing  12 , an associated applicator nozzle arrangement  14  and a lever  16 . The main body  12  includes a dosing dispenser  18  and a mounting plate  20 .  
         [0035]     The dosing dispenser  18  is of substantially cuboidal configuration and at one of its narrow sides has an electrical connection  22  for connection to a voltage source and a connection  24  for the feed of fluid. A solenoid (not shown here) which enables or interrupts the delivery of fluid from the applicator head  10  is supplied with power by way of the connection  22 . The mounting plate  20  is mounted to the side opposite to the connections  22 ,  24 , by two screws  26   a ,  26   b . In that case the screw  26   a  engages into a screwthreaded hole  28   a  (see  FIG. 6 ) and the screw  26   b  correspondingly engages into a screwthreaded hole  28   b  in the mounting plate  20 . The dosing dispenser  18  and the mounting plate  20  are flush with each other at three sides.  
         [0036]     The mounting plate  20  is positioned with a contact surface  30  against the dosing dispenser  18  (see also  FIGS. 5 and 6 ). The lever  16  is mounted pivotably by a pin  32  at that narrow side of the mounting plate  20 , which does not terminate with the narrow side of the dosing dispenser  18 . As  FIG. 6  shows in an exploded view, the pin  32  is accommodated in two mounting bores  34   a ,  34   b  in the mounting plate  20  and extends through a mounting bore  36  in the lever  16 .  
         [0037]     Disposed adjacent to the lever  16  on the mounting plate  20  is a rectangular contact plate  38 . An upper part of the contact plate  38  projects beyond the contact surface  30  of the mounting plate  20 , while a lower part is positioned with its rear side against the body of the mounting plate  20 . The contact plate  38  is screwed to the mounting plate  20  by a hexagon socket head screw  40  which extends through a hole  42 . A through bore  44  extends in the contact plate  38  in the lower end thereof, and a spring  46  extends through the through bore  44 . The spring  46  is positioned with one end against the body of the mounting plate  20  and with its other end against the lever  16 , and braces the two components against each other under pressure.  
         [0038]     At its end opposite the pin  32  and the contact point of the spring  46 , the lever  16  carries an adjusting screw  48  disposed in a screwthreaded hole. The screw, when rotated in the clockwise direction, tightens the lever  16  against the contact plate  38  so that the spring  46  is compressed. At the same end as the pin  32  and the support point of the spring  46 , the lever  16  terminates in a convex contour  50  which is proximate the mounting plate  20  and which in the present case is in the form of a circular arc.  
         [0039]     The mounting plate  20  has a nozzle contact surface  52  which extends parallel to the contact surface  30  and which is delimited by a projection  54  at its side opposite the lever  16 . The projection  54  is of such a configuration that the mounting plate  20  is substantially in the form of an L provided with serifs, the back of which is the contact surface  30 . In this arrangement the projection  54 , at its end remote from the contact surface  30 , has a flat guide surface  56  which faces towards the contact surface  52 . Rotation of the adjusting screw  48  in the clockwise direction moves the end of the lever  16  with the convex contour  50  towards the projection  54 .  
         [0040]     Between the contact surface  30  and the contact surface  52  a through bore  58  which is drilled out passes completely through the mounting plate  20 . An O-ring (not shown) is fitted into a groove in the through bore  58 . That O-ring serves to prevent leakage flows when the mounting plate  20  is mounted to the dosing dispenser  18 .  
         [0041]     Adjoining the side surfaces which are adjacent to the projection  54  and the lever  16  is a recess  59  which blends into the contact surface  52 . The internal width of the recess  59  is greater than the outside diameter of the O-ring (not shown) which is fitted into the groove in the through bore  58 . That prevents the O-ring from being sheared off when the mounting plate  20  is mounted to the applicator nozzle arrangement.  
         [0042]     Extending centrally through the projection  54  is a screwthreaded through bore  60  into which is screwed a centering pin  62  with a male screwthread thereon ( FIG. 6 , see  FIGS. 3 and 4 ). On its side which is closer to the lever  16  in the position of installation, the centering pin  62  has a raised portion  64  while on the side in opposite relationship to that raised portion it has a slot  66 . In the installed position, the centering pin  62  terminates flush with the projection  54  in such a way that only the raised portion  64  projects on the side of the centering pin that faces towards the lever  16  (see  FIG. 4 ).  
         [0043]     As  FIG. 2  shows, the flat guide surface  56  of the projection  54  forms an undercut configuration; together with the end of the lever  16 , which has the convex contour  50 , a space is thus formed jointly with the contact surface  52  for receiving the applicator nozzle arrangement  14 .  
         [0044]     The applicator nozzle arrangement  14  includes an adaptor plate  68  and a nozzle plate  70  which are connected together fixedly but releasably, for example by four screws ( FIG. 3 ). At an inlet side, or its side which in the position of installation is proximate the contact surface  52  of the mounting plate  20 , the applicator nozzle arrangement  14  has a contact surface  72 . In a first sidewall, or narrow side adjacent to the contact surface  72 , there is an arcuate recess  74  which extends along that narrow side and which is larger than the convex contour  50  of the lever  16  (see  FIG. 2 ). Provided on the opposite narrow side, or second sidewall, is a projection  76  in the form of a truncated pyramid, whose one narrow side terminates flush with the contact surface  72 . Disposed in opposite relationship to that surface is a sliding surface  78  which is inclined with respect to the contact surface  72  by the same angle as the guide surface  56  is inclined with respect to the contact surface  52 .  
         [0045]     Extending perpendicularly to the contact surface  72  in the projection  76  is a slot  80  which is of a depth that is greater than the amount by which the raised portion  64  of the centering pin  62  (see  FIG. 6 ) projects in the position of installation beyond the corresponding boundary surface of the projection  54 .  
         [0046]     Extending into the contact surface  72  is a bore  81  which is not visible in  FIG. 3  and which is therefore shown in broken line. It extends from the contact surface  72  through the applicator nozzle arrangement  14  and terminates in an underneath surface  82 , or outlet surface  82 , which is in opposite relationship to the contact surface  72 . The underneath surface  82  is that surface of the applicator nozzle arrangement  14 , which comes into contact with a movable substrate when fluid is being applied to the substrate. Positioned in the bore  81  is an O-ring  83 , which is also not visible in  FIG. 3  and is therefore shown in broken line, and which projects in part beyond the contact surface  72 .  
         [0047]     For the purposes of mounting the applicator nozzle arrangement  14  to the main body  12 , the applicator nozzle arrangement  14  is positioned beside the main body  12  in such a way that its contact surface  72  extends substantially parallel to the contact surface  30  of the main body  12 . The applicator nozzle arrangement  14  is then moved towards the main body  12  so that the sliding surface  78  comes into contact with the guide surface  56  and the recess  74  embraces the convex contour  50  of the lever  16  in a positively locking relationship. In that situation the applicator nozzle arrangement  14  is linearly guided by the projection  54  and by the convex contour  50  of the lever  16 .  
         [0048]     Provided on the applicator nozzle arrangement is an arresting pin  84  (see  FIGS. 1 and 2 ) which stops the movement of the applicator nozzle arrangement  14  by abutting against the lever  16  when the applicator nozzle arrangement is in the correct position. In that position, to secure the assembly, the centering pin  62  is screwed in, engaging into the slot  80  and thus securely fixing the applicator nozzle arrangement  14 .  
         [0049]     As an alternative to the centering pin  62 , a hollow pin  86  with a male screwthread is screwed into the through bore  60  ( FIG. 7 ). The hollow pin has a slot  90  on its one end face  88 . Extending from the end face  88  is a central axial blind bore  92 . Disposed opposite the end face  88  is a second end face  94 . The blind bore  92  extends along the longitudinal axis of the hollow pin  86 , terminates shortly before the end face  94 , and there goes into a second central bore  96  which extends axially from the end face  94 . Arranged in the region in which the blind bore  92  goes into the bore  96  is a ball  98  whose diameter is between the diameter of the bore  96  and that of the blind bore  92 . Acting against the ball  98  is a compression spring  100  which extends through the blind bore  92  and terminates at a closure portion  102  which terminates flush with the end face  88  and the slot  90  and is glued into the blind bore  92 . The compression spring  100  braces the ball  98  against the closure portion  102  so that a fraction of the ball  98  projects beyond the end face  94 . The ball is pressed into the blind bore  92  by pressing against the ball in opposition to the spring force.  
         [0050]     The hollow pin  86  and the centering pin  62  are alternatives which both co-operate with the slot  80 . The arresting pin  84  is a redundancy in relation to both so that only the arresting pin  84 , the centering pin  62 , or the hollow pin  86  is sufficient to guarantee that the applicator nozzle arrangement  14  is secured on the applicator head  10 .  
         [0051]      FIG. 8  shows the position of the hollow pin  86  upon installation in the mounting plate  20 . In that case the end face  94  terminates flush with the projection  54  so that only the ball  98  projects on the side proximate the lever  16 . When the applicator nozzle arrangement  14  is pushed into the space formed by the projection  54  and the convex contour  50 , the ball  98  is urged into the blind bore  92  (see  FIG. 7 ) by the projection  76  (see  FIG. 3 ). When the applicator nozzle arrangement  14  is in the correct position relative to the mounting plate  20 , the ball  98  snaps into the slot  80  (see  FIG. 3 ) by virtue of the force exerted by the compression spring  100  (see  FIG. 7 ) and thus secures the applicator nozzle arrangement  14  relative to the mounting plate  20 .  
         [0052]     A torque is applied to the lever  16  by rotating the adjusting screw  48  through 180°-360° in the clockwise direction. As a result of that torque, the end of the lever  16  with the convex contour  50  moves further into the recess  74  and applies a force to the applicator nozzle arrangement  14 , which extends substantially parallel to the contact surfaces  52  and  72 . That force urges the applicator nozzle arrangement  14  in a direction towards the projection  54 . In that situation the sliding surface  78  slides against the flat guide surface  56  of the projection  54 , with the applicator nozzle arrangement  14  being moved further towards the main body  12 . In that case the projection acts as a support for the lever  16  such that the applicator nozzle arrangement  14  and the main body are braced relative to each other. To this end, the bores  58  and  81  are directly one above the other and are sealed off relative to each other by the O-ring  83 .  
         [0053]     To release the connection between the applicator nozzle arrangement  14  and the main body  12  the adjusting screw  48  is rotated in the anti-clockwise direction. This reduces the force applied to the adaptor plate  68  by the lever  16 . The applicator nozzle arrangement  14  is then removed from the main body  12  by a translatory movement.  
         [0054]     Such a fixing mechanism means that different adaptor plates  68  which are adapted in respect of their design configurations to the respective situation of use can be easily and quickly fixed and released.