DE1214591B - Machine for the production, filling and sealing of stable bags - Google Patents

Description

Machine for the production, filling and sealing of stable bags The invention relates to a machine for manufacturing, filling and sealing of stable bags with an essentially square cross-section made of a weldable or sealable gusseted tube, which can be moved step-by-step with feed means Advancing the tubing material by one of the desired cutting length for the Bag corresponding amount, with a severing device for severing a bag length from one end of the gradually advanced tubing, with holding devices, also with a device for producing a base and at least one bag filling and locking station is provided.

Machines for making such bags from weldable or sealable material Gusseted tubes are already known. In such machines, the hose material in each case by an amount corresponding to the desired cutting length advanced and then one end of the tubing heated and compressed, whereby the material is welded together and the hose end is closed will. The desired bag length is then cut off from the hose material.

By unfolding the hose section closed at one end such a bag is formed, with the closed one to achieve stability End of the section still to form a substantially perpendicular to the Side walls running bottom must be reshaped.

The filling and welding of the manufactured by the aforementioned method The bag can be designed so that the container is either in the path of movement of the tubular material used for bag production is filled and welded or that the bag after welding one end and after separating from Tubing material from the path of tubing material to special filling and sealing stations to be led. When the filling and sealing of the bags is in the path of movement of the Tubing is to take place, the devices can be simple in their structure and be compact. However, the speed of operation of such devices is limited, so that for reasons of economy, as a rule, from the above second option mentioned is made use of. When the filling and Closing the container carried out outside the path of movement of the hose material machines with rotary tables or turret heads are usually used, which in a special way for the quick removal of the separated and one-sided welded bag blanks from the Suitable path of movement of the hose material are.

When a bag making machine is combined with those described above Kind of having a machine to fill and seal the bags in places that are are spaced from the path of tubing, there is a difficulty in it, the bags from the manufacturing machine to the filling and sealing device respectively. In a machine of this type, the bag can move in the path of the Tubing material are produced while using an additional device is passed over the filling and welding or sealing stations. With this machine the said difficulty is overcome, and it becomes not just the problem of Transfer of ready-formed bags via the filling and sealing stations released, but this machine also enables a more uniform bag formation, see above that achieves a noticeable saving in hose material in the manufacture of the pouch can be. The forming or manufacturing time of the bags in each station is the same the time it takes to advance the tube material by one bag cut length is required.

The object of the present invention is to provide a Machine for making, filling and closing of stable ones Build from a weldable or sealable gusseted hose in which the hose material or after separation, the bag blanks are detected by holders and one after the other to form, fill and seal stations, their processing and filling times synchronized with the advance of the hose material is to be guided.

With the machine to be created, the production, filling and Closing the bag is continuous.

Based on a machine known from the prior art for the production, filling and sealing of stable bags with square Cross-section from a weldable or sealable gusseted tube with on both Rollers attacking hose sides or other suitable means of displacement of the hose to a separator and to one with brackets for the separated hose sections provided conveyor is according to the invention provided The object is achieved in that the holders for the bag blanks from the top End in the side folds of the tube sections insertable side jaws and one these associated, radially displaceable opposing jaws exist in known Way are arranged on the circumference of a gradually revolving conveyor table, the a device for welding the lower one at successive stations End of the hose section, one consisting of an air nozzle and a support Device for expanding the hose section to a square cross-section and for shaping the bottom and means for filling and sealing the bags assigned.

In a further and expedient embodiment of the invention, the Side jaws rotatably mounted on a pivot pin and with the radially displaceable Counter jaw be controlled depending on their radial position in the forced run. The side jaws and the counter jaw can with interacting control edges be provided, which are arranged so that when there is a displacement of the opposing jaw The side jaws spread radially inwards towards the turntable into the open position are, and a return spring can be arranged on the side jaws, which this returns to the closed position when the counter jaw with respect to the turntable is pushed radially outward into its forward position.

The radial displacement of the counter jaw can after another Feature of the invention expediently carried out by a slide which with the Feed means, e.g. B. feed rollers, is connected for the hose material and synchronously cooperates with these, so that during the feed movement of the hose material the counter jaw moved radially and the side jaws with their holding shoes in the open position are guided.

According to a further feature of the invention, in the station for welding the lower end of the hose section two opposite sides of the hose section acting jaws for closing of the bag bottom section during a period of standstill of the turntable or Turret head and underneath heating elements for heating the intended for bottom formation Be arranged area of a hose section received by the jaws.

In a likewise further embodiment of the invention, in the Welding station or, in a subsequent position, centering and holding jaws be arranged to close the opposite sides of the lower, too Heating area of the bag sections are suitable.

Behind the bottom closure station is the inflation station with the in placed the bag opening insertable air nozzle, with on the bag support Rigid walls are arranged covering the lower portion of the bag during inflation lead so that the bottom area of the bag when inflated from between the Walls formed slot pushed out and the bottom is unfolded.

Two side plates are arranged to hold and support the bag, which are attached to a rear plate connected to the bracket.

One or more bag filling stations can expediently be located behind the inflation station with at least one bag opening device and mounted on pivotable levers Nozzles from which measured quantities can be filled into the bags, be arranged. A loading device can also be assigned to each holder be, which is arranged together with the bracket on the turntable and indexed and a funnel, dispensing nozzles and a guide between the funnel and the dispensing nozzles, and each loading device can be attached to a carriage, which is radially displaceable relative to the turntable, be attached. Anyone can do this Funnel filling device arranged at a station a container for the bag filling material al, a measuring compartment, valve means between the container and the measuring compartment and further valve means for releasing the bag filling material from the Have measuring compartment in the funnel arranged below.

According to a further feature of the invention, any holder have a measuring vessel connected to it, which together with the holder the turntable is arranged and indexable and for the most part each Rotation of the turntable is supplied with bag filling material, each measuring device is connected to nozzles by means of a line and a valve arrangement, which rotatably arranged on a slide which is radially displaceable relative to the turntable In a further useful embodiment of the invention is after the last filling station a plunger arranged, which recesses and one acting on the counter jaws Has rod which opens the holding shoes of the side jaws, so that the bag is released and the plunger at the same time the open end of the bag in the holding area the retaining shoes squeeze, lock and hold.

In the following, the invention is to be illustrated with reference to the drawings Embodiments of the machine according to the invention are described in more detail. The invention however, it is not limited to these embodiments. 1 to 5 show the steps for forming, filling and closing a container.

F i g. Figure 6 is a top plan view of a turntable with arrangements for opening of the container, FIG. 7 is a plan view of a jaw assembly according to the invention; F i g. 8 is a side view of the jaw assembly shown in FIG. 7; Fig. Figure 9 is a bottom plan view of the jaw assembly with the jaws in their open position Position, fig. 10 is a partial view of a section of the rear jaw lever assembly; 11 is a single side view of the hose advancing assembly and the slide for actuating the counter jaw, FIG. 12 a side view of the bottom sealing arrangement, the arrangement being shown in the heating position, FIG. 13 is a side view the in F i g. 12 in the clamping position, FIG. 14 shows a perspective Representation of the in F i g. 12, FIG. 15 is a partial perspective view the one direction for guiding the hose section, Fig. 16 is a side view of the device for inflating the bags, FIG. 17 is a partial representation of the device shown in FIG. 16, the air nozzle is also in a pivoted position 18 and 19 in plan view the insertion of the air nozzle into the upper one Bag opening or the air nozzle in the inserted state, FIG. 20 the bag loader in a side view, F i g. 21 the solenoid valve assembly with the suction head for Opening of the bag in a partial perspective view, FIG. 22 after the suction head F i g. 21 in plan view, FIG. 23 is a perspective view of the arrangement for changing the handle of the jaws, FIG. 24 shows a plan view of the arrangement according to FIG. 23 on its forward path to open the jaws, FIG. 25 the arrangement according to F 1 G. 24 with the jaws in the fully retracted position FIG. 26 shows the arrangement according to FIG. 24 after the operation has ended and the The jaws have encompassed the outside of the bag, FIG. 27 shows an arrangement for sealing of the upper part of the container in a schematic side view, FIG. 28 the ejector cam in a perspective partial representation, FIG. 29 shows a suction head which is in operation in a partial perspective view when opening a bag in a loading station, 30 shows a schematic representation of a sixteen working stages Machine in plan view, Fig. 31 a loading device in the disengaged position, seen from the side, FIG. 32 shows the loading device according to FIG. 31 in the operating position, 33 shows a side view of a heating device in stations B 'and C ", FIG. 34 an arrangement for heating and sealing the floor in a subsequent station D ', likewise in a side view, FIG. 35, an arranged in a further station E ' Floor cooling device in side view, F i g. 36 shows an arrangement for inflating the Bag in the following station F 'in side view, FIGS. 37 to 40 the progressive one Formation of a square bottom on the bag in the inflation station F 'according to Fig. 36, F i g. 41 a section through the feed device for the loading arrangements, F i g. 42 a and 42 b the transfer arrangement of the station L 'in side and top view, 43a and 43b show the heating device assigned to stations M 'and N' in side view or plan view, F i g. 44 is a side view of the upper sealing unit, FIG. 45 is a side view of the ejector assembly at station P ', FIGS. 46 and 47 Modifications of the heating arrangement, partly in section, FIG. 48 one optional the arrangement to be used for the suction plates.

In the machine according to the invention, a length of gusseted tube deformed into a bag, which can then be loaded with a filling and subsequently is to be finally sealed. The successive stages through which the tubing material is passed through until a filled and sealed bag is obtained, FIGS. 1 to 5 show.

The gusseted tube used to make the bag is on known and has two flat, essentially parallel sides 11 a and 11 b, which at their adjacent side edges by the folded side walls 11 c and ii b are connected. The lower end 12 becomes a pouch to form a pouch Hose section 11 clamped together, and the two sides 11 a and 11 b as well the intermediate folded sides 11 c and 11 d are in a common Seam welded together.

In the next stage, a gas, e.g. B. air, nitrogen or the like, inserted into the partially formed bag through the upper end 13 thereof.

This inflates the bag, with the sides 11 a, 11 b and bloc, 11 d are pushed apart and have substantially flat side walls form.

Since the side walls are welded together at one end 12 of the bag are, the lower end of the bag is closed and a substantially flat bottom formed, the walls 11 c and 11 d in the transverse direction and the folded Fold walls 11 a and lid inwards. Since the hose material 11 made of semi-rigid If there is material, the bag shape created by the inflation remains Removal of the internal pressure is essentially retained. Although the bottoming out can be achieved solely by the application of internal pressure, this can also be achieved by Application of an external, upward force to the floor sections supports will. After the internal pressurization, the bag has essentially the in F i g. 3 square shape shown. The bag can now be filled.

In the last working stage, the upper, open end 13 of the bag closed, clamped and according to the representation in F i g. 5 in similar Welded way, as already described with respect to the lower end 12 became.

The machine for making, filling and sealing the bags consists essentially from a frame with four vertical frame parts, one of these Frame parts supported rectangular upper frame, a base plate and an intermediate plate. Between the intermediate plate and the rectangular upper frame is on one of the Intermediate plate mounted vertical shaft a turntable 28 is arranged. The drive of the device is carried out by an electric motor arranged on the base plate via a a main shaft acting belt drive. The turntable 28 has twelve brackets 40 equipped to accommodate bag blanks. The brackets are on the perimeter of the turntable 28 in the area of a peripheral flange 28 a at equal intervals arranged from each other The turntable stands with a disc 51, which is attached to the lower The end of the shaft driving the turntable is fixed and has twelve rollers, in drive connection. The rollers are on a circle at equal distances from each other arranged and arrive one after the other with a cam mounted on the main shaft for cooperation from which a desired law of motion on the turntable 28 is transmitted. This means that the turntable is indexed with the same indexing angles guaranteed in all stations.

Each holder 40 for receiving the bag blanks 11 consists of two side jaws 41 and 42, which are rotatably mounted on a pivot 28 b and by means of a helical spring 43 acting at its front ends in the closed position are held, as well as a counter jaw 45, which between the side jaws 41 and 42 is arranged. The counter jaw 45 is one on a vertical arm Arranged toggle lever 45 a, which is rotatable on a pin 45 b between the side walls 28 d and 28 e of the turntable 28 is mounted (see FIG. F i g. 7 to 9). On the lever 45 a engages a return spring 46, which the counter jaw 45 radially outwards presses.

The toggle lever 45 a is provided with a protruding portion 45 f (see. Fig. 10), and the counter jaw 45 has a stop 45g, which extends through the counter jaw extends through and beyond it. Parts 45f and 45g can in the individual stations individually and independently of one another Push rod or the like. Are detected, whereby the counter jaw 45 against the action the spring 46 can be displaced radially inward towards the center of the turntable can. Each of the side jaws 41, 42 is at its front end with one inward directed retaining shoe 41 au 42 a, whose inner surface 41 b, 42 b (cf. F i g. 9 and z. B. Fig. 29) cooperates with the front surface 45h of the opposing jaw 45 and so forms the gripping surfaces of the jaws. Furthermore, each side jaw 41, 42 is with Rollers 41 c and 42 c and the counter jaw 45 provided with control edges 45 j, which are in plant and work together. When the brackets 40 are in the Are in the closed position (Fig. 7 or 29), the counter jaw is from the return spring 46 pressed into their front position, and the side jaws 41, 42 are from the spring 43 pressed inwards, with the front surface 45h of the opposing jaw 45 on the inner surfaces 41b, 42b of the side jaws rests.

If a push rod (e.g. slider 75 or 180a in Figs. 11 or 23 to 26) is advanced towards the part 45f or 45g, then the counter jaw 45 is moved radially inward against the action of the spring 46, wherein the side jaws 41, 42 remain closed until the control edges 45 j the Counter jaw 45 with the rollers 41c, 42c of the side jaws 41, 42 for contact and interaction come. Another shift in the Jaw 45 in the same direction causes a Pivoting the side jaws 41, 42 outwards against the tension force of the return spring 43. Conversely, the side jaws 41, 42 move into the closed position as a result of the spring force, as soon as the counter jaw 45 is pushed radially outward (by the spring 46, if the slides release the sections 45f or 45g) and the control edges 45 j except Engage with the rollers 41 c, 42 c.

In the schematic turntable representation according to Fig. 6, let the station at which the hose material is fed, denoted by A. The feeding of the Hose material is illustrated in detail in Fig. 11 of the drawings. The flat, compressed gusseted tube 14 is attached to the device by a Roll or a reel 53 via guide rollers 54 to 56 and fed to the rollers 57, 58 deflected vertically downwards. The gusseted tube is in the vertical area guided by guides 59, 60 which can be moved up and down. Below these tours a separating device 61 is arranged. The drive for the feed device is removed from the main drive shaft in the machine frame and via a connecting rod 66 by means of a toothed rack 66a on one with the deflection roller 57 in connection Transfer gear 57 a. Here, between the directly on the hose material 14 acting pulley 57 and the gear 57 a a coupling device (not shown) be arranged, which an indexing of the roller 57 in only one direction of rotation ensures. In Fig. 11 is the rack 66 a by means of on a slide rod 67 a mounted and pressed by the spring 67 b pressure roller 67 with the gear 57 a pressed into engagement. On the shaft 63 driving the connecting rod 66 are a plurality of cams arranged, of which the cam 63b cooperates with the cam follower 68, whereby the guide 59, 60, which can be moved up and down, for the hose material 14 is actuated via the drive connection 69. The guides 59, 60 engage by means of their protruding guide portions (Fig. 15) on both sides in the side folds of the tubing 14, creating a partial opening of the compressed flat Hose material is brought about. The hose material is in the deflection area of the roller 57 guided between the roller 57 and a pressure roller 58 cooperating with it. The roller 58 is controlled by a magnet 58 a. The advance of the tubing material takes place only when the hose material is pressed by pressing the roller 58 against the feed roller 57 is pressed. The pressing of the roller 58 ensuring the magnet 58 a can be operated in response to a photoelectric device 70, wherein the photoelectric device in connection with markings on the hose material 14 operates, so that hereby a control of the desired feed length of the hose material is achieved. The cutting device 61 is also driven by a device on the Shaft 63 arranged control cam 63c and a toggle linkage arrangement 71, 72. The control cam 63 d for actuating the toggle lever arrangement is on the same shaft 63 74 provided.

While the tubing material 14 is being fed to the FIG. 11 shown bracket 40 move the up and down movable guides 59, 60 down in the direction of the bracket, and the slide 75 is pushed forward by means of the aforementioned cam 63d and the toggle lever 74 (in Fig. 11 to the left), whereby the slide 75 on the section 45f of the counter-jaw 45 strikes and the opposing jaw also radially with respect to the turntable 28 is shifted inward.

As a result, the control edges 45j of the opposing jaw 45 come with the rollers 41 c, 42 c of the side jaws 41, 42 for cooperation, and the side jaws are opened. Now the means of the guide sections of the guides 59, 60 in its side gussets partially open side gusset tube 40 over the holding shoes 41 b, 42 b of the side jaws out. Once the tubing is around the desired Feed length is advanced, the photoelectric device 70 is a On the hose material located marking perceived, and the magnet 58 a brings the pressure roller 58 out of engagement with the hose material, so that the Feed roller 57 slips through the hose material 14 without pushing it forward. Since the drive shaft 63 for the connecting rod 66 preferably rotates uniformly, the rack 66a is moved down as soon as the in the connecting rod slot engaging pin 65 through the top dead center and on its circular path moved on.

So that the direction opposite to the feed direction of the hose material Direction of rotation of the gear 57 a cooperating with the rack 66 a during this phase of movement of the connecting rod 66 is not transferred to the feed roller 57 is, now occurs the one-way clutch, not shown, between the gear 57 a and the feed roller 57 in action, whereby the gear 57 a in this direction of rotation runs empty. During this movement phase runs due to the appropriate design of the cam 63 d the slide rod 75 actuated by the toggle lever 64 back, whereby the section of the opposing jaw 45 which interacts with the slide rod released and the counter jaw by means of the return spring 46 in the z. B. in F i G. 7 position shown is returned, whereby the control edges 45j out of engagement get with the rollers 41 c, 42 c of the side jaws 41, 42 and the side jaws be guided into the closed position by means of their return spring 43, the Holding shoes 41 b, 42 b corresponding to the illustration in FIG. 29 for bag production provided hose section in the area of its upper end against the frontal Press surface 45 a of the counter jaw. Thereafter, the separating device 61 is by means of of the cam 63 is actuated via the knee lever 71 and the linkage 72 and a hose section 11 separated from the hose material 14 corresponding length. Now the Turntable 28 to z. B. 300 switched on, the supplied with a blank Bracket in station B and the next bracket 40 in station A got. In station A, the bracket now located there is in the above described manner supplied with a hose material blank, while with its holder in the station B forwarded blank in this station is closed at its lower ends.

In station B, the hose section 11 is between a pair Clamping jaws 81, 82 clamped, which by a cam follower 83 by means of a on the shaft 87 arranged cam 84 are operated. The cam follower acts here 83 transfers directly to the clamping jaw 82 and a projection arranged thereon the advance movement of the same by means of a two-armed lever 85 and a connecting rod so on the opposite jaw 81 that both jaws at one Actuation by cam follower 83 is substantially uniform to one another to move until the lower portion of the hose section 11 between the clamping jaws 81, 82 is pinched (see FIG. 12). Below the lower end of the hose section 11 is one of two heating elements 91, 92, which are located within a reflector 93 are stored, arranged existing heating device, which by means of the guide 94 and one likewise cooperating with a cam arranged on the shaft 87 Idler 95 is vertically displaceable. If between the jaws 81, 82 of the is clamped lower portion of a hose section 11, is located Heating device in the in F i g. 12 shown advanced position in which the lower portion of the hose section is heated. Advancing the heater takes place by means of the tension spring 97 acting on the cam follower 95 when the on the shaft 87 arranged cams a corresponding pivoting movement of the cam follower allows. In the course of one revolution of the cam, the heating device becomes accordingly lowered according to the law of motion established by the cam track, reducing the heating effect is essentially interrupted (see FIG. 13). Simultaneously with the lowering the heating device, the cam track allows the cam follower 83 a return movement, and the clamping jaws 81, 82 are arranged on the two-armed lever 85 by means of the Return spring 88 returned to the open position. As a result of the effect of the Springs 88, 97 are in constant contact with the cam followers 83, 95 the assigned cam tracks. While the jaws 81, 82 in the open position are performed and thereby the heated lower section of the hose section release, the pressure plates 101, 102 close and press the heated lower one Section of the hose section together, whereby the lower end of the bag through a single seam is formed. To quickly dissipate heat from the weld To ensure at the lower end of the bag, the pressure plates 101, 102 are by means of Pipes 101 a, 102 a connected to a cooling system for the purpose of cooling. As shown in FIGS. 12, 13 shows, the pressure plates 101, 102 can be the heated grasp the lower end of the bag section only when the clamping jaws 81, 82 are in the open position.

After the bottom of the bag 11 is welded, the turntable becomes 28 advanced by a further partial rotation to stations C and D, in which a labeling of the bag, not shown in detail, takes place. After labeling the bracket 40 under consideration is switched to station E according to FIG. In this position, in a manner similar to that in station C, a suction plate is initially used 140 brought up to the container wall 11 a in the area of the upper, open container end, sucked up the container wall and when taking back the suction plate, which in contrast to the arrangement in station C from a cam 144 over a Cam follower 143 and a toggle lever assembly 142 is actuated, entrained, whereby the upper end of the container is opened in the manner already described above. the In this arrangement, suction plate 140 is connected to a suction line 140 a. Together with the control cam 44 for actuating the suction plate is a control cam 146 mounted on the shaft 145, which has a push rod 147 and a two-armed Lever 148 actuates a tube 150 with the air nozzle 149 and the air nozzle into the upper, the now open end of the bag introduces, the air nozzle is by means of the lever 148, 157 and an intermediate plate 155 guided essentially parallel to the block 158. The air nozzle 49 is on the intermediate plate 155 by means of the pivot pin 155a rotatably articulated and at a distance from the pivot pin 155 a by means of the spring 156 supported (cf. FIGS. 16 and 17). Is in the non-operational position As a result of the tension force of the spring 156, the air nozzle 149 according to FIG. 17 in a Inclined position. When lowering the air nozzle in the manner described above, it hits front end of the nozzle against a guide body 159 which is attached to the suction plate 140 is attached, whereby the air nozzle is deflected from its pivoted position and in the upper opening of the bag 11 as shown in FIG. 18 is inserted will. After the air nozzle is inserted into the open end of the bag, the over actuated cam follower 143 and toggle assembly 142 from cam 144 Suction plate shifted again in the direction of the counter jaw 45, whereby accordingly the illustration in Fig. 19, the air nozzle essentially between the at least partially flexible walls of the upper, open end of the container is clamped. Now the inside of the bag is acted upon by compressed air from the air nozzle 149 and the bag inflated. Fold the bag depending on the increasing air pressure the lower areas of the bag spread apart and form the bottom section of the bag.

The soil formation is achieved by the soil support shown in FIG effectively supported by the plate 151. The plate 151 is on a two-armed Lever 152 arranged, which at the end opposite the plate of a third control cam 153 mounted on shaft 145 is actuated. After inflating of the bag and the molding of the bottom section, the suction plate 140 and the air nozzle 149 is withdrawn, which is achieved by appropriate design of the corresponding Cam tracks associated with cam followers is achieved in a simple manner.

When the air nozzle is lifted out of the opening of the bag, it becomes pivoted again due to the tensile force of the spring 159 and initially in the area of Bag opening supported by the guide 159 in a similar manner as above has been described in relation to the insertion of the air nozzle into the top opening of the bag.

After the bottom has been formed in station E, the turntable 28 switches on to a first loading station F. In this station, the first 8augplatte 160, which is supported by the cam 165 mounted on the shaft 166 via the Cam follower 164 and the linkage or toggle lever assembly 163, 162 actuated is, in the same way as the: suction plate 140 in the previous station against the Upper bag section driven and spread the side wall 11 a of the bag and thereby the bag opened. Then the loading nozzle 167, which is similar Like the air nozzle 149 in the previous station of one likewise cams supported on shaft 166 via push rod 170 and the parallelogram linkage assembly 168, 169 is actuated, inserted into the bag opening. After inserting the Feeding nozzle 167 into the bag opening moves the suction plate 160 so far forward, that the bag opening around the loading nozzle is largely closed. Bag filling material is then fed into the interior of the bag through the loading nozzle entered, and then the suction plate and the feed nozzle in the in relation to the previous station described manner in their starting positions returned and the turntable 28 switched to the next station. The on the first loading station F following stations G and H are completely the same In the same way as station F is designed as a loading station (see Fig. 20 and 29).

After the turntable 28, the bracket 40 under consideration with the now If the filled bag 11 is switched on, the bag arrives at station J, where the upper end of the bag is closed. For this it is necessary to use the grip of the holding shoes 41 a, 42 a of the side jaws 41, 42 from their position in the fold of the Seitenwändellc, 11 d to move outwards behind the side wall 11 a of the bag. Show this the F i g. 23 to 26. In the station J opposite the counter jaw 45 is a radial arranged in the direction of the opposing jaw displaceable block 180, which over the cam follower 183 is actuated by the control cam 181 mounted on the shaft 182 will.

A plunger 180 a is connected to the block 180, which is in the direction of the projection 45g of the opposing jaw 45 over the open end of the bag extends. As the cam 181 revolves, the block 180 moves in the direction of the holder 40 shifted, whereby the plunger 180a on the projection 45g of the opposing jaw 45 and the counter jaw in the direction of the pivot pin 28b of the side jaws 41, 42 shifts. In doing so, the stalk surface facing the upper end of the bag comes into play of the block 180 with the side wall 11 a of the bag 11 in the area of the bag opening to the plant, and the upper bag section is between this face and the Opposite surface of the opposing jaw 45 clamped. In the event of a further radial shift of the block 180, the rear control edges of the opposing jaw 45 act on corresponding ones Control edges or roll the side jaws so that the side jaws are around their pivot pins 28 b are spread and the holding shoes 41 a, 42 a out of engagement with the side folds get the bag (see. Figs. 24 and 25).

The one at its upper end between the counter jaw 45 and the end face 180 d of the block 180 clamped bag is, as F i g. 25 shows so far radial displaced that the front surface 80d facing bag side 11a behind the holding shoes 41 a, 42 a of the side jaws 41, 42 arrives. Then the return of the block begins 180, which takes place as a function of the shape of the cam track of the control cam 181, and the opposing jaw, which is under the action of the return spring 46, follows this return movement. This will get there the cooperating control edges of the counter jaw and the side jaws are disengaged, and the side jaws are released from the return spring 43 brought into the closed position, which is now the Seitenwandlla of the bag reach behind, as shown in FIG. So that the holding shoes can be gripped properly 41 a, 42 a of the side jaws is guaranteed, are in the engagement area of the holding shoes Recesses 180 b, 180 c arranged in the end face 180 d of the block 180. Before the side jaws with their holding shoes 41 a, 42 a the full support of the Take over the bag, a device 187 occurs, which of a likewise occurs The control cam 185 mounted on the shaft 182 is actuated via the push rod 186 and alignment shoes 187 b, 187 c on a carrier 187 a, in action. the Alignment shoes are lowered onto the bag walls that are pressed together at the top and align them so that the cut edges of the bag material are in one plane and can be welded properly. The alignment shoes 187 b, 187 c are arranged on the U-shaped support 187 a, which the block 180 mounted plunger 180a overlaps on both sides.

From station 1, the turntable switches the one provided with the bags Bracket40 to the station K, where the closed and from the holding shoes of the side jaws held bag end is sealed. The device for sealing is shown in FIG G. 27 and completely identical to the device already described for sealing the bottom section according to FIGS. 12 and 13. In the case of the one shown in FIG The device is the same as with the device for sealing the bottom section the container material is initially clamped between the clamping jaws 195, 196 and the heating device 190 to 194 led into the heating position, whereupon after sufficient Heating of the section to be sealed, the heating device and the clamping jaws are withdrawn and the compression of the heated wall sections of the bag takes place by means of the pressure jaws 197, 198. After sealing, the pressure jaws give 197, 198 the upper end of the bag with the finished weld seam free, and the turntable switches the holder to the following station L.

A cam 199 is arranged in station L (see FIG. 28), which is movable in the direction of the projection 45g and the counter jaw 45 radially in the direction of the pivot 28 b of the side jaws 41, 42 moves, whereby the interacting control edges of the counter jaw and the side jaws the side jaws Lead into the open position and the holding shoes 41 a, 42 a release the bag.

The filled bag can by means not shown, such as For example, a drop device, a conveyor belt or the like, removed from the machine will. In order to ensure that as a result of the bentel filling on the the section of the bag acting on the holding shoes of the side jaws does not lead to the tearing off of this section, is useful in the delivery station L the bottom of the bag is supported by a support plate 202 extending from the reciprocating support device 151 at station E to station L extends and on which the bag base surface can slide (see support plate 202 in Fig. 20). As a further support, page plates 204, 209 are provided be interconnected by a back plate 206 and attached to the turntable are arranged. These side plates 204, 205 (see example FIG. 7) are used for side and rear support of the bag while it is being transported from a station to the next along the support rail or support plate 202 is continued.

It goes without saying that the drives for the individual stations are timed to match. The suction plates in the various stations can be carried out in exactly the same way as shown in FIGS be. Since all stations work at the same time, the suction plates of the individual Stations also operated by actuators of completely identical design be. As shown in Figure 21, the suction plate consists of a block 230, which is arranged on an actuating rod 231, which serves as the core of the solenoid 232 serves. The suction line 240 is connected to the block 230, which according to FIG via the channels 230a, Z30b, 230c with the suction nozzles 233b, 233c of the actual suction section g 233 is connected.

There is a recess between the suction nozzles of the suction section 233 233 a is provided, in the area of which the air nozzle 149 or the feed nozzles 167 be inserted into the bag opening. As shown in Fig. 7, the suction plates are in stations C, E, F, G, H via the corresponding connecting lines to a common vacuum line 241 connected.

In the modified embodiment shown in FIGS a machine for the production, filling and sealing of bags from a weldable or sealable gusseted tube, the basic structure of the arrangement is correct with the first embodiment. In the following, therefore, mainly the modifications of this embodiment will be described.

In the embodiment shown in FIGS. 31, 32, the loading devices are arranged together with the brackets 40 on the turntable 311 and are through Cam 312 mounted above the turntable is actuated. The loading devices are on plates 313, which with bearing blocks 313 a, 313 b to support the guide rods 314, 315 are provided, stored. On the guide rods 314, 315 is located a carriage 316 which has a roller 317 in the cam track 312 at the bottom of the cam 311 has. This rests the carriage 316 on the guide rods 314, 315 controlled by the cam 312. At the front end of the carriage 316 is a rotatably mounted arm 318 connected, at the front end of several nozzles 319 are arranged, which via the channel 320 with the funnel 321 in connection stand. Radially protruding beyond the front end of the rotatably mounted arm 18 a cam 322 is arranged, which with a stationary arranged cam 323 can come to cooperation when the feeder from the carriage 316 is pushed radially outward. As a result, the arm 318 is pivoted, and the nozzles 319 reach the filling position. As already mentioned above, takes place the radial displacement of the carriage 316 as a function of the course of the cam track 312 a, with which the roller 317 mounted on the carriage cooperates.

The loading of the holders arranged on the turntable 311 40 takes place in the same way; as described with respect to the first embodiment is. When indexing the turntable 312 from station A 'to station B' (see.

Fig. 30) the bottom section of the container blank is in the Area of the floor heating device shown in FIG. 33, while the upper area of the container blank in the manner described above from the holding shoes of Side jaws is held. In the station B 'is again by means of a not shown Punching device a perforation in the area of the upper bag opening in a bag side wall stamped.

The in F i g. 33 illustrated floor heating device of station B ' consists of a cast body attached to the machine frame, not shown, which is provided with a bearing 350 a and the reciprocating rod 351 receives. The frame 352 is also connected to the cast body. The rod 351 carries a Bearing plate 353 on which the actual heating device 354 is arranged. At the frame part 352, the two legs 356 are connected to which the pivot pin 357, 358 are stored. Arms -359,361 are attached to the pivot pins as well two levers 360, 362 extending substantially perpendicular thereto, which at their the Heater 354 facing ends via pivot pins 363, 364 to a U-shaped Brackets 365 are connected, which with a push rod 366 over the pivot 367 is connected By actuating the push rod 364, the jaws 359, 361 can be operated. Independently of this, the heating device 354 can by means of the in the storage 350a guided rod in the heating position or in the rest position be moved. In station C 'there is an essentially similar heating device arranged, which also in the station C 'a heating for. the bottom welding Provided sections of the bag blank guaranteed.

In the station D 'is on the one hand by a labeling device, not shown in the area of a punched perforation in the side wall at the upper end of the bag a label is applied and the lower portion of the bag, which in the previous Stations B ', C' is already heated, sealed. The device for sealing of the bottom portion of the bag is constructed in a manner similar to that of the devices in stations B ', C', but with an additional pair of sealing jaws 376, 377 is arranged (cf.

Fig. 34.) In contrast to the arrangement according to Fig. 33, the jaws have 359, 361 in the area of their bearings by means of the bolts 357, 358 protruding sections 359a, 361a, which extend essentially parallel to the levers 360, 362. On the projections 359 a, 361 a by means of the bolts 372, 373 connecting straps 370, 371 connected, which with support arms 376 a, 377 a of the sealing jaws 376, 377 are connected.

By operating the U-shaped body 365 by means of the push rod 366 are thus both the jaws 359, 361 and the sealing jaws 376, 377 operated in the same direction. After in the previous stations the lower section of the hose section is heated by pressing the lower wall sections together of the bag the lower end of the bag is welded by means of the sealing jaws 376, 377. The jaws are then released, and the holder 40 with the one in the bottom area The sealed bag is passed on to the next station E ', in which the Lower section of the bag is sandwiched between cooling jaws for quick To ensure heat dissipation and thus solidification of the weld seam.

When switching the turntable from station D 'to station E 'is welded to the bottom of the bag through a at the top of a fixed jaw 381 attached guide track so that the container bottom lies between the fixed jaw 381 and a movable jaw 382 when the turntable comes to a standstill (see. Fig. 35). The jaw 381 is by means of Screw bolt 384 with a bracket attached to the fixed part of the machine 383, while the jaw 382 is connected to one through an opening 381a in the jaw 381 extending therethrough slide 382 a is connected, which via the Linkage arrangement 385 to 392 of the control cam 393 against the action of the return spring 394, which the jaw 382 into the. Closing position leads, is actuated. It is the toggle lever 386 - by means of the pivot pin 387 on the one connected to the machine frame Bracket 383 or a projection 383 b arranged on this bracket.

The jaws 381, 382 are provided with channels 381b, 382b for the passage of a Equipped with coolant.

When the turntable is indexed, the with the now arrives its lower end welded hose section provided holder 40 in the Inflation station F '(see. Fig. 36). The means of inflation is essential identical to that in relation to the first embodiment according to FIG. 16 described Arrangement. Only instead of the suction plate arrangement 140 are elastic ones Plate 419 and a support bracket 420 with a lever 422 on the plate carrier 417 arranged. The plate carrier 417 is in the same way as the suction plate holder stored in FIG. 16 and as a function of the cam track of the control cam 144 can be actuated back and forth on the shaft 145. The one on the support bracket 420 by means of the pivot pin 420 a mounted lever 422 has a portion 422 a, which according to the Depiction in Fig. 38 engages in the opening of the bag and the side wall 10a on the return of the plate carrier 417 spreads so that the air nozzle 149 into the bag opening is insertable. The lever 422 is actuated by means of an electromagnet 424, which works together with a soft iron block 425 arranged on the plate carrier 417. When the plate carrier 417 with the elastic plate 419 in the direction of the upper end of the bag held by the side jaws 41 is guided, the lever engages over 422 with its section 422a, the side wall 10a of the bag, whereupon by actuation desElektromagnets 424 the lever is pivoted so that the section 422 a in the bag opening engages. Subsequently, in relation to the first embodiment already-described way the air nozzle 149 is introduced into the bag opening and, like the fig. 37 to 40 show - the bag inflated. Likewise in contrast for the first embodiment, the lower end of the bag is in one of the plates 426 formed slot 426 a, from which the lower one, welded The bag section slides out during inflation, as in particular FIGS. 39 and 40 demonstrate.

After the bottom formation of the bag by inflating and finished the air nozzle is returned to its original position, the turntable is switched on, and the holder with the bag arrives at station G '.

The station G 'is the hopper filling arrangement shown in Fig. 41, which essentially consists of a container 430 and the valve assemblies 432, 435 exists, assigned. The valves are operated by the one with the Machine frame firmly connected arm 443 mounted magnet 441.

The connecting member 438 c is with the iron core 441 a, which is enclosed concentrically by the magnet windings 441 b, in connection. To the Link 438 c is above the U-shaped bracket 438 a, 438 b by means of the Guide 437 in the bore 437a mounted sleeve 436 via the flanges 436a, 436 b connected. The valve stem 433 is axially displaceable within the sleeve stored and in the area of the U-shaped bracket 438 a, 438 b by means of the spring 439 supported on the flange 433 a. At the lower end in the area of the measuring chamber or nozzle 431 is connected to the valve stem 433 of the valve body 432, which with a valve seat surface 431 a cooperates and by means of the distance from the valve plate located guide 432 a is secured against tilting. On the sleeve 436 is the second valve body 435 between a flange part 436 a and a coil spring 440, which is supported on the bearing 437, is arranged. When the valve body 432 is in the closed position, the valve body 435 is open, and out of the interior of the container 430, bag filling material can flow into the metering chamber 431. As soon by actuating the magnet 441, the valve body 432 is axially displaced, d. H. opened is, the valve body 435 comes under the action of the coil spring 440 in the Closed position and seals the connection between the interior of the container 430 and the metering chamber 431. Since the funnel 321 (cf. F i g. 31 and 32) under the funnel filling device according to FIG. 41 is located, flows the bag filling material located in the metering chamber 431 when the valve body is open 432 into funnel 321. The transfer of the hopper filling material from the hopper 321 in the container 319 takes place in the manner already described, the carriage 316 carrying the funnel on the pivotably mounted arm 318 in FIG advanced position according to FIG. 32 is located and the cam 322 with the stationary Cam 323 arranged on the machine frame cooperates. Such funnel filling arrangements can be used in several following stations, e.g. B. in the stations H ', J', K ', arranged be, whereby different fillings can be introduced into the bags.

When the turntable moves on to station L ', the bag is filled completed and the loading device in the position shown in FIG withdrawn so that the area above the bag 11 is free.

In the station L 'are in a similar manner to the first embodiment the side jaws implemented so that their holding shoes behind the side wall 11a of the Grab the bag (cf. form 1 the Fig.23 to 26 and to embodiment 2 F i g. 42 a and 42 b. The device for moving the side jaws according to FIG. 42 a and 42 b has two slide rods 451, 452 which are attached to a frame part 450 are stored and are arranged essentially parallyl to one another. Every slide bar is provided with a fork-shaped section 451 a, 452 a, in which the toggle lever engaged rollers 455, 458. The toggle levers 453, 457 are on pivot pins stored and connected to push rods 456, 459. The slide rod 451 is on front end provided with a rotatably mounted roller460, which is so arranged is that it cooperates with the portion 45g of the counter jaw 45 when the slide rod is pushed forward. The second slide bar is provided with a bracket 461, on which a lever 462 is rotatably mounted, which is under tension by a spring 463 is held, whereby the roller 464 arranged at the rear end of the lever 462 is in engagement with the cam track 450a. That in the area of after Converting the side jaws 41 closed bag opening protruding other end of the Lever 462 is provided with sloping surfaces at the bottom, and one downwards protruding portion 461 a of the bracket 461 has a flat vertical front on, which is cut out so that the section 461 a between the side jaws 41, 42 can go through. The implementation of the holding shoes 41 a, 42 a of the side jaws 41, 42 takes place in the same way as in the first embodiment described above, the slide rod 451 replacing the plunger 180 a and the slide rod 452 takes the place of the reciprocating block 180. The shift of the Slide rods 451, 452 are actuated according to a fixed law of motion of the push rods 456, 459 connected to the toggle levers 453, 457.

After the turntable has advanced to station M ', this will be from behind the holding shoes of the side jaws 41, 42, closed upper Bag end by means of the in F i g. 43 a and 43 b illustrated device heated. The upper end of the bag is located between the two sliding rods471, 472 arranged jaws 47in, 472 a. The slide bars are on the machine frame 473 mounted so as to be movable to and fro, the actuation by means of the toggle levers 476, 481 takes place, which with their rollers 475, 480 in U-shaped sections 474, 479 of the slide rods engage and by means of the push rods 478, 482 around their pivot pin 477 after a desired law of motion can be actuated. The jaws 471 a, 472 a are provided with cooling channels 47po, 472 e. Furthermore, on the machine frame 473 a means the guide 483 and the intermediate member 486, the heating device 487 is arranged. By actuating the push rod 485 connected to the guide 483, the Heating device 487 can be moved into or out of the heating position. During the warming up of the upper end of the bag to be welded are those with cooling channels 471 e, 472 e provided jaws 47in, 472 a in the closed position, so that only the over the jaws in the direction of the heater 487 protruding portion of the Bag material is heated. A second heater of the same type Execution is arranged in station N '. After -in the stations M ', N' the to the sealing portion of the bag material is sufficiently heated, the turntable becomes switched on, and the bag arrives at the closing device assigned to station 0 ' according to FIG. 44. The locking device has a fixed jaw 491 and a pivotable one arranged on the machine frame 490 by means of the pivot 492 Jaw 494, which can be actuated by means of the according to a desired law of motion Push rod 495 via lever arms 493 a, 493 b into the closed or open position is actuatable.

The closing jaws 491, 494 are by means of the lines 496, 496 a with Cooling agent is supplied to ensure rapid hardening of the by pressing the To ensure closing jaws formed weld seam at the upper end of the container.

After the upper end of the container has been welded, the turntable switches continue to the station ', where the mounting of the side jaws by means of the one shown in Fig. 45 Device is solved. For this purpose it is connected to a machine frame Bracket 499 a two-armed lever 502, 503 pivotable by means of the pivot 501 connected, which can be actuated by means of the according to a desired law of motion Push rod 505 can be actuated and at its in the area of the protruding Cam 45g of the opposing jaw 45 protruding end carries a roller 504, which a pivoting of the two-armed lever the opposing jaw radially in the direction of moves the pivot pin 28b of the side jaws, causing the side jaws to slide into the Open position are guided. As a result of the release of the upper end of the bag the holding shoes of the side jaws fall completely filled and sealed Bags on a conveyor belt Z and is used for packaging and shipping purposes discharged from the machine.

In the last-described embodiment of the machine forms the station Q 'a reserve station. After the turntable 311 from the delivery station P 'via the reserve station Q' to station A 'begins for the looked at bracket the same duty cycle again.

46 and 47 are possible modifications of the heating device shown. According to Fi g. 46 is the heating coil 612 in a slot 611a of a ceramic Block 611 stored. When the heater is in the operating position the section to be heated protrudes, e.g. B. the bottom area of the bag 11 in into the recess 611, as shown in FIG. In the case of the in FIG. 47 illustrated Heating device are two heating coils -614, 615 in inside the recess 613a the ceramic block 613 stored. In the same way as with the modification according to FIG. 46 protrudes the portion to be heated of the bag 11 in the Heizsteliung into the recess 613 a.

In Fig. 48 is a particular embodiment of a suction device illustrates, in which a cylinder 630 can be reciprocated by means of the links 631, 632 is stored on the machine frame. The links 631, 632 form a parallel guide. The front end of the cylinder is closed by the end plate 630a. In the End plate is a suction plate 633 with the interior of the cylinder 630 connecting small hole 630b.

A sealing ring 634a is provided within the cylinder Piston 634 slidably mounted, which is connected to a connecting rod 635 is.

The connecting rod G35 stands over the pin 636 a with a back and forth moveableeii lever 636 in connection. When operating this arrangement, the frictional force which the piston has to overcome during its sliding movement and consequently onto the cylinder transmits, somewhat smaller than the frictional force required to overcome the joint friction would be expended in the joint connections of the cylinder on the links 631, 632. This ensures that when the piston 634 moves in FIG on the left first the piston is immersed in the cylinder and then the cylinder on the Links 631, 632 is pivoted until the suction plate 633 with the corresponding Side wall of the bag, e.g. B. with the side wall 11 a, comes into contact. By the plant of the suction plate on the corresponding container wall 11a corrects the movement of the cylinder 630 comes to a standstill, and the piston 634 is completely immersed in the cylinder 630 a, whereby the air trapped in the cylinder is pushed out through the opening 630 b will. As soon as the direction of movement of the piston is reversed, the suction effect of the piston, the side wall 11 a of the bag from the suction plate 633, which is preferably consists of at least partially elastic material, detected and in the same way splayed from the remaining wall areas of the bag, as described in connection with the embodiments explained above has already been described.

Claims (1)

Claims: 1. Machine for manufacturing, filling and sealing of stable bags with a square cross-section made of a weldable or sealable one Side-gusseted hose, with spindles that engage on both sides of the hose for advancement of the hose to a separator and to one with brackets for the conveyor provided with separated hose sections, characterized in that the holders for the tube sections (11) from the upper end in the side folds insertable side jaws (41, 42) and one of these associated, radially displaceable Counter jaw (45) are made in a known manner on the circumference of a gradually revolving Conveyor table (28) are arranged, which a device at successive stations for welding the lower end of the Schlatichabschnittes, one from an air nozzle (149) and a support (t51) existing device for expanding the hose section on a square cross-section and for shaping the floor and facilities züm Filling and closing of the bag are assigned 2. Device according to claim 1, characterized in that the side jaws (41, 42) on a pivot pin (28b) rotatably mounted and with the radially displaceable counter jaw (45) as a function are controlled by their radial position in forced operation. 3. Apparatus according to claim 2, characterized in that the side jaws (41, 42) and the counter jaw (45) are provided with interacting control edges, whereby the side jaws when the counter jaw is displaced radially inwards to the turntable or turret head (28, 311) into the open position are spread, and that the side jaws by means of a spring (43) in the closed position be guided when the counter jaw due to the action of the return spring (43) is pushed into its front position. 4. Apparatus according to claim 3, characterized in that one with Slides (75, 180) coupled to the drive of the hose feed rollers (57, 58) are provided which acts on the counter jaw (45) to move it radially inward, whereby the side jaws (41, 42) with their holding shoes (41 a, 42 a) to receive open a hose section (11). 5. Device according to claim 1 and / or one or more of the claims 2 to 4, characterized in that in the station (B) for welding the lower End of the hose section (11) two on opposite sides of the hose section (11) acting jaws (101, 102; 376, 377; 641, 649) for closing the bag bottom section during a period of standstill of the turntable or turret head (28, 311) and including heating elements (91, 92; 612; 614, 615) for heating the soil provided area of a hose section received by the jaws are. 6. Apparatus according to claim 5, characterized in that in the Welding station (B, C) or a subsequent position to close the opposite one Sides of the lower, to be heated area of the hose section centering and Holding jaws (81, 82; 359, 361; 381, 382) are arranged. 7. The device according to claim 1 and one or more of the preceding Claims, characterized in that the inflation station behind the bottom closure station is arranged with the air nozzle (149) which can be inserted into the bag opening (13) and that on the support (151) rigid walls (426) are arranged, which during inflating the lower portion of the bag (11) in one between the walls Formed slot (426a) lead, so that when the bag is inflated, its bottom area is forced out of the slot and the bottom is unfolded. 8. Apparatus according to claim 7, characterized in that on the Bag holder (40) side plates (204, 205) are arranged, which on a rear, are attached to the bracket (40) connected plate (206). 9. The device according to claim 1 and one or more of the claims 2 to 8, characterized in that one or more behind the inflation station Bag filling stations with at least one bag opening device (160, 233, 720) and nozzles (167) mounted on pivotable levers (168, 169) through the measured Filling quantities can be filled into the bag (11) are arranged. 10. Apparatus according to claim 9, characterized in that each Holder (40) is assigned a loading device, which together with the Holder is arranged on the turntable and is indexed, and that the Loading device a hopper (321), dispensing nozzles (319) and a guide (320) between the hopper (321) and the nozzles (319) and that each loading device (319, 320, 321) is rotatably attached to a carriage (316) which is relative to the Turntable or turret head (28 or 311) is radially displaceable. 11. The device according to claim 10, characterized in that each a hopper filling device arranged at a station, a container (430) for bag filling material, a measuring compartment (431), valve means (435) between the container (430) and the measuring compartment (431) and a further valve device (432) for releasing the bag filling material from the measuring compartment into the funnel (321) arranged below. 12. The device according to claim 1 and one or more of the claims 2 to 11, characterized in that each holder (40) is connected to a Has measuring device (712) which can be switched further together with the holder and over most of each revolution of the turntable with bag filler material is supplied, and that each measuring vessel (712) by means of a line (714) and a Valve assembly (713) is connected to nozzles (319) which are rotatable on a slide (316), which is radially displaceable relative to the turntable, are arranged. 13. The device according to claim 1 and one or more of the claims 2 to 12, characterized in that after the last filling station a ram (180) is arranged, which recesses (180 b, 180 c) and one on the counter jaws (45) has acting rod (180 a), which the holding shoes (41 a, 42 a) of the The side jaws (41, 42) open so that the bag (11) is released and the plunger (180) at the same time the open end of the bag in the holding area of the shoes (4asa, 42a) squeezes, locks and holds. Documents considered: German Patent No. 1 033 581; Austrian Patent No. 208 301; French patents No. 1,136,300, 1141957; U.S. Patents Nos. 2,177,919, 2,643,496, 2759648, 2 868 375, 2 935 831. Older patents considered: German Patent No. 1 119 750.