US3182570A

US3182570A - Device for the production of bags

Info

Publication number: US3182570A
Application number: US289006A
Authority: US
Inventors: Egli Alwin
Original assignee: Schweizerische Industrie Gesellschaft
Current assignee: Schweizerische Industrie Gesellschaft
Priority date: 1962-07-11
Filing date: 1963-06-19
Publication date: 1965-05-11
Anticipated expiration: 1982-05-11
Also published as: GB1018424A

Description

May 11, 1965 A. EGLl DEVICE FOR THE PRODUCTION OF BAGS Filed June 19, 1963 United States Patent 1 Claim: c1. 93 12 The patent application Serial No. 48,944 filed on August 11, 1960 by Alwin Egli relates to a method for the production of bags from sheets cut to size as well as to a device for carrying out this method.

According to said patent application the device which comprises at least two main mandrels for the folding and interwelding of the bottom of the bags which are capable of being swung stepwise into various operative positions, is characterised by an auxiliary mandrel co-operating with the main mandrels and axially adjustable relative to the same with which are associated a folding box for the formation of the hose for the bags and heatable clamping and welding jaws for the formation of the longitudinal seam, and by feeder rollers for transferring the hose for the bags from the auxiliary mandrel to the main mandrel.

The invention has the object of providing an improvement of the device described in said patent application. It has been found that when working comparatively thin sheets e.g. foils of synthetic substances, into bags the transfer of the hose for the bags from the auxiliary mandrel to the main mandrel by means of the feeder rollers gives rise to break down. Since the hoses for the bags were pulled off by the rollers from the auxiliary mandrel but were pushed upon the main mandrels the case could arise in which they were set up on the main mandrels if they had not sumcient inherent stiffness. This disadvantage is to be overcome by the present invention.

With this and other objects in view which will become apparent from the following description and accompanying drawings, I provide a device for the production of bags from sheets cut to size having at least on its margins to be interwelded a surface consisting of thermo-plastic material, comprising in combination: two main mandrels arranged for being swung step-wise into various operative positions for the folding and interwelding of the bag bottoms, an auxiliary mandrel co-operating with said main mandrels and axially adjustable relative to the same, said auxiliary mandrel having a folding box for the formation of the hose bag and heatable clamping and welding jaws for the formation of the longitudinal seam of the said hose bag, a pair of tongs longitudinally movable in a 1ongitudinal groove of said main mandrels for the transfer of the hose bag from said auxiliary mandrel to said main mandrel.

These and other features of my said invention will be clearly understood from the following description of a preferred embodiment thereof given by way of example with reference to the accompanying drawing, which is diagrammatic side elevation of a device according to the invention.

On an arm 1 rigidly connected with the machine frame two bars 2, 3, are rigidly attached. On the bar 2 an auxiliary mandrel 4 is mounted axially slidable. Its displacement is effected by the turning of a lever 5 which is connected by a connecting rod 6 with the auxiliary mandrel 4, the displacement being effected in the working rhythm of the machine. On the bar 3 two

rocking levers

7, 8, are mounted which at their ends carry heatable jaws 9, which serve for the production of the longitudinal seam of the hose bag. The jaws 9 are heated in the usual manner electrically.

Below the auxiliary mandrel 4 a folding box 10 is arice ranged which is mounted vertically slidable on columns 11. It forms on its top a table which serves for receiving the sheets 12 from which the bag is to be produced. For the supply of the sheets 12 pairs of rollers 13 are provided. The folding box 10 is so constructed that in its uppermost position it can embrace the auxiliary mandrel 4 from three sides. The sheet 12 lying on top of the folding box 10 is folded around the auxiliary mandrel 4 when the folding box is moved to its uppermost end position. The longitudinal edges produced on top beyond the auxiliary mandrel and the folding box are then engaged by the heating jaws 9 and interwelded whereby the hose bag is formed.

On a vertical axle 14 a mandrel wheel 15, having for example four main mandrels 16, is arranged of which one is illustrated in elevation. The main mandrel 16 illustrated lies in axial alignment with the auxiliary mandrel 4, i.e. in the position in which the transfer of the hose bag 12 from the auxiliary mandrel to the main mandrel takes place. The lower wall 16a of the main mandrel is tiltable about an axle 17 in order to facilitate the fitting of the hose bag on it. The swinging-in of the wall 16a is effected automatically when the main mandrel 16 runs into the working position illustrated thereby that a roller 18 arranged on the lower wall 16a runs on a fixed guide rail 19. On top of the main mandrel 16 is moreover arranged a press jaw 20, which is mounted on a rocker arm 21 pivotable about an axle 22 which arm co-operates with a lever 23 actuated by the main drive of the machine. The press jaw 20 serves for arresting the hose bag transferred to the main mandrel 16. V

For the transfer of the hose bag from the auxiliary mandrel to the main mandrel a pair of tongs is provided. The same are mounted on a tongs slide 25 which is slidably mounted on two bars 26 arranged parallel to the main mandrel 16. The tongs slide 25 is moved to-andfro by means of a lever 27 connected to the main drive of the machine by means of a connecting rod 28. The tongs 24 engage into a longitudinal groove 29 of the main mandrel 16. The auxiliary mandrel 4 has likewise a corresponding groove at the end adjacent the main mandrel 16. The upper jaw of the tongs 24 is rigidly connected with the tongs slide 25. The lower jaw is, however, pivotably mounted on the tongs slide 25 and is connected with a lever 30 which co-operates at its lower end with the drop surface of an opener rail 31. A spring 33 tends to pull the lower jaw of the tongs into its closed position. The opener rail 31 is pivotably mounted on two parallel levers 32 which in turn are connected in a manner not illustrated with the main drive of the machine. By turning the lever 32 the opener rail 31 is raised parallel to itself, or lowered. By raising the opener rail accordingly the tongs 24 are opened, and by lowering the opener rail the tongs are again closed by the spring 33, independently of the position of the tong slide 25.

For transferring the hose bag 12' the auxiliary mandrel is firstly moved towards the main mandrel 16 by turning the lever 5. Thereafter the opener rail 31 is raised into its upper position so that the tongs 24 are opened. At the same time by means of the lever 27 the tongs slide 25 is shifted to the left-hand side into the position illustrated in chain dotted lines in which the margin of the hose bag 12 engages between the open jaws of the tongs 24. The opener rail 31 is then lowered so that the tongs 24 close, and clamp the hose bag fast. Then the tongs slide is moved towards the right again into its original position whereby the tongs 24 transfer the hose bag 12' to the main mandrel. When the hose bag abuts an abutment 34, the opener rail is again raised so that the tongs 24 release the hose bag and the jaws moved out of the same. Then the press jaw 20 is lowered and the mandrel wheel is turned into the next working position in which the further folding operations of the hose bag, i.e. the folding of the bottom of the bag are carried out.

Instead of a pair of tongs 24 two simultaneously operating tongs may be arranged side by side.

While I have described herein and illustrated in the accompanying drawing what may be considered a typical and particularly useful embodiment of my invention I Wish it to be understood that I do not limit myself to the particular details and dimensions described and illustrated; for obvious modifications will occur to a person skilled in the art.

What I claim as my invention and desire to secure by Letters Patent, is; i

A device for the production of bags of sheet blanks cut to size having at least on its margins to be interwelded a surface consisting of thermo-plastic material, comprising in combination: two main mandrels arranged for being stepwise rotated nto various operative positions for the folding and interwelding of the bag bottoms, an auxiliary mandrel cooperating with said main mandrels and axially adjustable relative to the same, said auxiliary mandrel having a folding box for the formation of the hose bag, and heatable clamping and welding jaws, a pair of tongs longitudinally movable in a longitudinal groove of one of said main mandrels for the transfer of the hose bag from said auxiliary mandrel to said main mandrel, an opener rail movable parallel to itself in a vertical direction, a tong slide movable in a direction parallel with said longitudinal groove, said pair of tongs being supported by said tong slide, and having jaws one of which is pivotally mounted on said tong slide, the other of said jaws being fixedly connected with said tong slide, a lever connected to said pivoted jaw of said tongs, said opener rail cooperating With said lever so that when the same is moved in parallelism said opener iai win pivot said lever and jaw connected therewith to move the same away from said fixed lever and open said tongs independent of the position of said tongs slide.

References Cited by the Examiner UNITED STATES PATENTS 6/58 Triolo 93 44.1 x 4/63 Egli 93 12