US2474136A - Packing of plastic material - Google Patents

Description

A. D. WILSON El AL -PAGKING OF PLASTIC MATERIAL June 21, 1949.

2 Sheets-Sheet 1 Filed April 25, 1946 QN k w h. mm w #r \M Ql i jizzrqn 2'07: ARTHUR DACRE WIl-JW 6 WILL/AN DMZ/Ely My 84 a 2 en- ATTURIY1$ I June 21, 1949. A. D. WILSON El AL PACKING OF PLASTIC MATERIAL 2 Sheets-Sheet 2 Filed April 25, 1946 Patented June 21, 1949 PACKING OF PLASTIC MATERIAL Arthur Dacre Wilson, Grays, and William Dalziel,

Birkenhead, England, assignors to Lever Brothers Company, a corporation of Maine Application April 23, 1946, Serial No. 664,419 In Great Britain April 26, 1945 The present invention relates to the packing of plastic materials such as margarine, lard and other materials of similar plasticity, and it relates particularly to devices for rapidly forming into blocks or prints the output from a machine producing the material continuously.

According to the present invention an arrangement for coupling a continuously operating machine for producing plastic materials such as margarine to an intermittently operating packing machine, comprises a connection between the outlet of the producing machine and the inlet of the packing machine for conducting the material under the output pressure of the producing machine to the packing machine, and means for applying additional pressure to the material in said connection while said packing machine is open to be charged and for releasing said pressure while said packing machine is closed,

said means serving to accommodate the material,

issuing from the producing machine during the period of closure of the packing machine.

The said means may comprise a cylinder and piston connected as a branch to said connection. While the packing machine is closed the piston moves up the cylinder to accommodate the continued feed of material into the connection from the producing machine. When the packing-machine opens, compressed air or mechanical pressure is applied behind the piston which forces the material at increased pressure to fill the packing machine. As soon as the latter closes the pressure behind the piston is released.

In what follows reference will be made, for simplicity of description, to the production of margarine, but it will be readily apparent that the invention can be applied to the production of other plastic materials on which similar operations are performed.

The invention will be described with reference to the accompanying drawings in which 7 Figure 1 shows diagrammatically a complete system for continuously processing margarine and Figure 2 shows the packing machine embodying the invention.

In the complete system for processing margarin shown in Figure 1, the starting materials (usually oil and milk) from supply tanks I and 2 are fed by pumping devices 3 and 4 through a conduit 5. The pumping devices 3 and 4 preferably are such as to supply the materials from the tanks I and 2 in the required proportions automatically.

The material passes along theconduit 5 to a processing apparatus 6 which may be of the well 6 Claims. (CI. 31-14) known type in which the ingredients to be mixed, emulsified and cooled, are passed through thinwalled nickel tubes surrounded bya cooling medium of evaporating liquid ammonia. The tubes are provided with internal rotating blades which remove the thin film of chilled material from the wall of the tubes. In this way the oil and milk are rapidly cooled and mixed. Details of such an apparatus, being well known, need not be fully illustrated in the present specification. The cooled mixture passes through from this processing apparatus 6 through conduit 1 into a arge diameter tube 8 in which the margarine sets and is brought to the final consistency desired by being passed through wire mesh screens fitted therein. From this tube 8 the product is ex- 21, which engages a step 28 in the reservoir wall 1 ing devices 3 and 4, and passes through a suitable connection ll into a packing machine which is indicated at 9. After wrapping, the packets of the product leave the packing machine 9 along the conveyor belt B. The packing machine, which has already been described, together with the means for connecting it to the producing machine, are illustrated in more detail in Figure 2, to which reference will now be made.

Between the extrusion outlet of the tube 8 and the inlet aperture in of the packing machine is a horizontal connection I I having such a suitable varying cross-section along its length that the margarine can flow withoutsubstantial restriction from the circular outlet 8 to the rectangular aperture ill of the packing machine.

The top of the connection Hbranches into a vertical cylindrical reservoir l8 fitted with a movable piston 19. A space 20 above the piston is connected, through a passage 2| opening into the top of the space beyond the permissible movement of the piston, with a slide valve 22 which can open the passage either to a source 23 of compressed air or to an exhaust hole 24 communicating with the atmosphere.

The piston IS in the reservoir It has its permissible movement in theupward direction limited by an upper stop, here, for exampie, illustrated in the form of a threaded rod 25 screwed into the top 26 of the reservoir l8, and adjustable from the outside. In the downward direction its movement is limited by providing it with a flange when the piston moves to the lowest desired limit of its travel. Preferably this lower stop 28 is so arranged that at the endof the down stroke the piston, suitably shaped, would form part of 3 the wall of the connection ll so that there is no dead pocket of margarine formed.

The cycle of operations is as follows: assume that a print has just been ejected from the diechamber I 2, the die-chamber 12 being closed to the connection by the knife l8, and the piston 19 being at some intermediate position between the two stops.

When the top II of the die-chamber [2, which had opened to allow the print to be.ejected, closes, the plunger l3 in the die-chamber l2 moves downwards, and at the same time the knife I 8 moves downward to open the side opening ll of the die-chamber I! to the store of margarine in the connection I I which is under the output pressure from the continuous producing machine. At the same time as the knife i8 exposes the opening I 4, the slide valve 22 connects the space 20 above the piston 19 in the cylinder l8 through the passage 2| to the source of compressed air 23, the pressure from which forces the piston l9 downward, and forces margarine very rapidly into the die-chamber l2. When the die-chamber I! has been filled, the knife it closes the opening I4 and at the same time the slide valve 22 connects the space 20 to the exhaust 24: thus releasing the pressure on the margarine in the connection II from the compressed air source. The cover plate [5 moves to open the top of the diechamber l2, the plunger l3 moves upwards to eject the print, which is pushed off the plunger It by the cover plate l5 of the die-chamber as it slides back to the left to close the latter. During the time that the die-chamber is closed by the knife It, more margarine is extruded from the producing machine into the connection II, and this continued production is accommodated by margarine passing into the cylinder IS, the piston IS in which moves upwards to accommodate this continued production.

The plunger i3 and knife IS in the die-chamber l2 move downward again, and the cycle of operations is repeated.

The movements of the print into the wrapping machinery may be as described in the British patent specification 565,143, accepted October 27, 1944. v

The movements of the knife is, plunger 13 and airvalve 22 and so forth are all controlled by lever systems 29, 30, M respectively operated by cams as shown in British patent No. 565,143. The levers 29 and 3| operating the knife [6 and the valve 22 are connected to work together.

Preferably the connection II is fitted with a pressure gauge and a relief valve fixed at 32, and both the connection H and the cylinder l8 are preferably water jacketed so that the margarine may be made to fiow as a plug by maintaining the jacket at a suitable temperature.

In order that the packing machine may ac- 4 up, as this position indicates that more material is being produced than is being taken up by the packing machine. the excess flowing into the cylinder and keeping the piston at the upper limit I of its permitted travel. If the piston-remains at the lower end of its travel the opposite condition is. indicated, and the packing machine is slowed down. Such control means may take any suitable form. In Figure 1 such control means are illustrated by the rod 33, lost motion device 35 (serving to lose the motion of the piston due to the actual filling and accommodating steps), and resistance 38. This latter resistance is varied according to the position oi the rod 33 and, being connected in series with the electrical supply mains 31 to the motor 38 driving the packing machine, controls the speed of the latter as described above. I

We claim:

1. An arrangement for coupling a continuously operating machine for producing plastic materials to an intermittently operating packing machine, said arrangement comprising a connection between the outlet of the producing machine and the inlet of the packing machine for conducting the material under the output pressure of the commodate the material at the rate it issues from the producing machine, the movement of the mean position of the piston, which indicates the excess or deficiency of material being produced by the producing machine in relation to the rate of working of the packing machine, may be used to control the relative speeds of two machines. For example, the rod 33 connected to the piston and passing through an air-tight gland 34 in the top 26 of the cylinder It may be used to operate an electrical control which alters the speed of an electric motor driving the packing machine. This control operates in such a way that when the piston m'oves within a range at the upper end of the cylinder, the packing machine is speeded producing machine to the packing machine, means for opening and closing said inlet, a chamber communicating with said connection, displaceable means in said chamber for varying the capacity of said chamber, and means for applying pressure to said displaceable means to reduce the capacity of said chamber while said inlet is open and for releasing said pressure to permit the.

capacity of said chamber to increase while said inlet is closed.

2. An arrangement for coupling a continuously operating machine for producing plastic materials to an intermittently operating packing machine, said arrangement comprising a connection between the outlet of the producing machine and the inlet of the packing machine for conducting the material under the output pressure of the producing machine to the packing machine, means for opening and closing the inlet of said packing machine, a variable capacity chamber communicating with said connection, and means for applying pressure to said chamber to decrease its capacity while said inlet is open to be charged and for releasing said pressure applied to said chamber to permit its capacity to increase while said inlet is closed, said chamber serving to accommodate the material issuing from the producing machine while the inlet of said packing machine is closed.

3. An arrangement for coupling a continuously operating machine for producing plastic materials, to an intermittently operating packing machine, said arrangement comprising a connection between the outlet of the producing machine and the inlet of the packing machine for conducting the material under the output pressure of the producing machine to the packing machine, a cylinder connected as a branch to said connection, a piston within said cylinder, and means for applying pressure behindsaid piston and thence to the material in said connection while said packing machine is open to be charged and for releasing said pressure while said packing machine is closed.

4. An arrangement for coupling a continuously operating machine for producing plastic materials to an intermittently operating packing machine, said arrangement comprising a connection between the outlet of the producing machine and the inlet of the packing machine for conducting the material under the output pressure of the producing machine to the packing machine, a cylinder connected as a branch to said connection, a piston within said cylinder, a source of compressed air, and means for connecting the space in said cylinder behind said piston to said source while said packing machine is open to be charged and for connecting said space to the atmosphere while said packing. machine is closed.

5. An arrangement for forming prints of plastic material from a machine continuously producing said material, said arrangement comprising a die-chamber, means for cyclically opening said die-chamber to permit it to be filled and thereafter closing it, means for ejecting prints therefrom, a connection to said die-chamber from said machine, a branch on said connection for accommodating material issuing from said masaid die-chamber to permit it to be filled and thereafter closing it, means for ejecting prints therefrom, a connection to said die-chamber from said machine, a piston forming at least a part of the bounding wall of said connection, and

means for applying pressure to said piston while said die-chamber is open, and for releasing said pressure while said die-chamber is closed, so that said piston can move to accommodate plastic material entering the connection during the closure period of said die-chamber.

ARTHUR DACRE WILSON. WILLIAM DALZIEL.

REFERENCES CITED The following referenices are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,282,308 Dahlin May 12, 1942 2,329,287 Miller Sept. 14, 1943 2,329,288 Miller Sept. 14, 1943 2,373,865 Walter Apr. 1'7, 1945 FOREIGN PATENTS Number Country Date 565,143 Great Britain Oct. 27, 1944 666,824 Germany Oct. 28, 1938

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