apparatus 1 shown in the figures applies fluid on a substrate ( not shown ) which is movable relative to the apparatus 1 . typically , the substrate may comprise sheets of film or foil which are transported past the apparatus 1 . of course the surfaces of other substrates could also be coated , such as packaging material or other materials . referring to fig1 apparatus or applicator head 1 has a main body 2 and a fluid supply passage 4 which can be connected to a source of adhesive ( not shown ). the fluid supply passage 4 can be in the form of a cylindrical hole bored in the main body 2 and is supplied with fluid , such as adhesive , through a supply passage , such as in a flexible adhesive line ( not shown ). the main body can have an upper part 3 and a lower part 5 which are threaded together . there is a cylindrical distribution passage 6 inside the main body 2 , which like the fluid supply passage 4 extends the entire length of the applicator head 1 . the distribution passage 6 is formed half as a semi - cylindrical recess in the upper part 3 and the other half as a semi - cylindrical recess in the lower part 5 , so that the distribution passage 6 can easily be cleaned other shapes may be used instead . the distribution passage 6 communicates with a horizontal slot 8 in a slotted nozzle assembly 10 . the slot 8 opens into an elongated outlet aperture 12 , from which adhesive flows during operation and is then transferred to the substrate . above the fluid supply passage 4 , attached to the main body 2 , there are six application valves 14 for selectively stopping and starting the flow of adhesive from the fluid supply passage 4 into the distribution passage 6 and thus through the slot 8 . of course , other manners of controlling the fluid flow may be used instead . in this implementation example , and as those of ordinary skill will understand , each application valve 14 is designed as a pneumatically operable valve and has a needle 16 which is coupled with a pressurized gas piston that is positioned for movement in a cylinder , and can be moved up and down when pressure differences are applied to the piston . the lower section of the needle 16 interacts with a valve seat which is formed on the main body 2 . in the immediate vicinity of the valve seat , between the fluid supply passage 4 and the distribution passage 6 , there is a vertical connecting hole , which is closed by the point of the needle 16 when the application valve is in the closed position and is open when the needle 16 is in the open position . each application valve 14 has a connecting hole associated with it . in a manner which is not shown , the application valves 14 are connected to pressurized gas lines . as fig2 and 3 illustrate , a stopper 18 is positioned movably in the slot 8 of the slotted nozzle assembly 10 and seals off the slot 8 laterally . the stopper 18 is rigidly coupled with a cylindrical piston 20 , which is axially movable within the distribution passage 6 . the stopper 18 extends from the piston 20 to the outlet aperture 12 of the slotted nozzle assembly 10 . the piston 20 has an outer jacket 22 , which is attached to a threaded sleeve 24 . the threaded sleeve 24 is part of an adjusting device 26 , for varying the length of the slot 8 by shifting the stopper 18 in the slot 8 together with the piston 20 in the distribution passage 6 . the adjusting device 26 also has a threaded spindle 30 which is mounted by two ball bearings 28 so that it can rotate . male threads of spindle 30 engage female threads of the threaded sleeve 24 . the ball bearings 28 are set into a plate 32 . attached to the end of the threaded spindle is a hand wheel 34 for manually turning and adjusting the adjusting device 26 . turning the hand wheel 34 rotates the threaded spindle 30 , causing the threaded sleeve 24 , the piston 20 and the stopper 18 to be moved axially in the direction of the longitudinal axis of the slot 8 and of the distribution passage 6 , so that depending on the direction in which the hand wheel 34 is turned the length of the slot — viewed in the longitudinal direction of the application head 1 — is reduced or increased , and thus is variable . those of ordinary skill will recognize that other mechanisms may be used to provide axial movement of such a stopper 18 . the main body 2 , and with it the entire application head 1 , is mounted so that it can be moved back and forth relative to a fixed - position frame in the direction of the longitudinal axis of the slot 8 of the slotted nozzle assembly 10 and fixed in different positions by a guiding and adjusting device . the guiding and adjusting device has two supports 36 which can be attached to a frame of a production apparatus ( not shown ) and attached to them two mutually parallel cylindrical guide rods 38 , 39 , and surrounding the guide rods 38 , 39 the linear guides 40 , 42 , 44 , 46 ; these have several rollers which roll along the guide rods 38 , 39 . the lower section of the main body 2 is screwed together with the linear guides 40 , 42 , 44 , 46 . that enables the main body 2 to move linearly along the longitudinal axes of the guide rods 38 , 39 . the guide rods 38 , 39 have their end sections connected to the supports 36 by screws , as shown in fig1 . the linear guides are screwed to the main body 2 of several angle sections . the guiding and adjusting device also has a threaded spindle 50 with male threads which is mounted in the plate 32 with ball bearings so that it can rotate , as well as a threaded piece with female threads which is engaged with the male threads of the threaded spindle 50 and is screwed to an angle section 48 ( see fig1 ). turning a hand wheel 54 which is coupled with the threaded spindle 50 causes the main body 2 and thus the entire application head 1 to move back and forth linearly depending on the direction of rotation of the hand wheel 54 . the maximum travel displacement depends on the length of the guide rods 38 , 39 . the main body 2 is fixed in any position desired by the friction between the male threads of the threaded spindle 50 and the female threads of the threaded piece 52 . the hand wheels 34 and 54 and the threaded spindles 30 and 50 are positioned on one side relative to the main body 2 , so that they can be operated simply from one side in order to vary the length of the slot 8 and the position of the main body 2 , and thus of the application head 1 . fig3 to 8 illustrate a substrate guiding device for transporting a sheet of film or foil or the like past the outlet aperture 12 of the slotted nozzle assembly 10 along a defined travel path . the substrate guiding device has a frame 58 which is mounted on the main body 2 so that it can be rotated by two pneumatic cylinders 56 , and two parallel guide elements 60 , 62 with a space between them , designed as guide rods with a polished surface , which can be rotated simultaneously and fixed in various rotated positions . the two guide rods 60 , 62 are mounted by their end sections on two plates 64 , 66 , which can be rotated around a rotational axis 68 ( see fig7 ) relative to the frame 58 . it can be seen from fig3 and 5 that the frame 58 , the plates 64 , 66 and the guide elements 60 , 62 can be rotated with the help of the pneumatic cylinder 56 from a first diverted position to a second operating position , and the substrate can be moved past the outlet aperture 12 by adjusting the rotational position of the plates 64 , 66 and fixing them with screws in an optimal position for guiding the substrate according to the needs of the application . alternatively , instead of the guide elements 60 , 62 there can be a pressure roller opposite the outlet aperture 12 . while the present invention has been illustrated by a description of a preferred embodiments and while these embodiments have been described in some detail , it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail . additional advantages and modifications will readily appear to those skilled in the art . the various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user . this has been a description of the present invention , along with the preferred methods of practicing the present invention as currently known . however , the invention itself should only be defined by the appended claims , wherein .