US2723789A - Means for exhausting the air from a food-containing bag and then heat sealing the same - Google Patents

Description

Nov. l5, 1955 E M. SCHILD 2,723,789

MEANS FOR EXHAUSTING 'THE AIR FROM A FOOD-CONTAINING BAG AND THEN HEAT SEALING THE SAME Filed Feb. 23, 1955 FIG. 9"

54 5g x 66` 40/ I |.5|8||||||||||||||||||;`5 50 FIG. 3.

INVENTOR 98 EDWARD M. Scl-ULD.

ATT NEY United States Patent() MEANS FOR EXHAUSTING THE AIR FROM A FOOD-CONTAINING y BAG AND THEN HEAT SEALING THE SANIE Edward M. Schild, Bayside, N. Y. Application February 23, 1955, Serial No. 489,953

7 Claims. (Cl. 226-56) This invention relates to means for exhausting the air from a food-containing bag and then heat sealing the same.

The mechanism herein described and claimed has many uses. In the first place, itis adapted to exhaust the air from a plastic food bag or the like and to create a vacuum therein. Reference is here made particularly but not exclusively to plastic bags in which frankfurters and like food products are packed. The object is to help preserve the food products over relatively long periods of time.

This mechanism also is adapted to function in reverse or at least partly in reverse. It has two nozzles. Both nozzles may be connected to a vacuum pump and consequently both nozzles may be employed to exhaust the air from a plastic bag or the like. On the other hand, one nozzle may be connected to a vacuum pump and the other to a pressure pump which, in turn, may be connected to a container for a suitable liquid food or preservative or the like. For example, the container might contain a sauce or pickling solution. In such case, the mechanism herein described would function through one nozzle to suck air out of the bag and through the other nozzle to till the bag with an appropriate liquid substance. It should be understood at this point that the mechanism is not limited to exhausting` air from a food bag and pumping a liquid preparation into said bag. The mechanism may also be employed to replace the exhausted `air with an inert gas to help preserve its food content. In such case, one nozzle may be connected to a vacuum pump and the other may be connected to an inert gas pump. t

An important object ofthe invention is the provision of adjustable nozzles of the character described. There are two such nozzles and both are adapted to fit into the same bag. The conventional vacuum forming apparatus of this general-character visprovided with a single nozzle of xed dimensions. Consequently, such nozzle would be adapted for use in connection with bags .of substantially corresponding dimensions, reference being here made to the dimensions of the open end of the bags. In the present invention, on the other hand, each nozzle is relatively small as compared with the size of the bag opening, and the two nozzles are adjustable toward and away from each other to accommodate bags of various dimensions. This is extremely important since ya single mechanism' of the character herein claimed is able to perform the work of a number of conventional mechanisms, each of a different size.

Another important feature of this invention is `the swivel mounting under tension of one' of the two nozzles. The two`nozzles are normally disposedon a common horizontal plane and in parallel' relation to each other. One of these nozzles is swivelly movable about a vertical axis toward and away from the other nozzle vand a spring is provided to urge sa-iclswivelly mounted. nozzleto move away from the-other nozzle. When a -bag the swivelly mounted nozzle a short arcuate distance in the direction of the other nozzle in order to fit the two nozzles into the bag. When said swivelly mounted nozzle is then released, it swings away from the other nozzle under the inlluence of the spring and thereby engages the bag and holds it taut. This is important both for the vacuum forming process above described and also for the heat sealing process hereinafter described. This feature constitutes a tensioning means for eliminating creases in the bags.

Still another important feature of this invention is the provision of bag sealing means by which the bag is held snug against the nozzles in air-tight relation thereto to enable them to exhaust the air from said bags. One of the reasons why Vacuum forming machines of this general character have heretofore been provided with only a single nozzle is that no practical way has heretofore been developed for holding the bags tight against more than one nozzle mounted in spaced relation to each other. In the present invention a pair of resilient presser bars are provided, one below and the other above the two nozzles and when the bag is mounted on said noz zles and held in taut condition by them, as above described, the two presser bars move toward each other into clamping relation to said bag and nozzles and since the bars are resilient, they conform to the shape of the nozzles and seal the bag against'air leaks.

Still another important object of this invention is the provision of heat sealing means by which the bags may be heat sealed following the vacuum forming process. A pair of heater bars, or a single heater bar and a pressure bar, are provided on opposite sides of the bags when they are mounted on the nozzles. After the bags are clamped tight on the nozzles and the air is exhausted therefrom, one of said heat' sealing bars is swung in the direction of the other heat sealing bar'and the bag is thereby squeezed or pressed between them. Heat is applied in suflicient degree to plasticize the material of which the bag is made and to weld the bag closed. The swingable heat sealing bar is pivoted on a common axis with one of the resilient pressure bars and this feature renders it possible to seal the bags immediately adjacent thearea in which they are clamped upon the nozzles.

The invention is illustrated in the accompanying drawing in which:

Fig. 1 is a plan view of a vacuum forming and heat sealing device of the character herein claimed.

iS slipped over the two nozzles, it is necessary to swing Fig. 2 is a vertical section therethrough on the line 2-2 of Fig. l.

Fig. 3 is a side view of said device, partly broken away and in section to expose one of the heat sealing bars.

The vacuum forming and heat sealing device herein claimed is provided with a table 10 on which a package 12 of frankfurters or other food products may be placed for the vacuum forming and heat sealing operations hereinafter mentioned. A typical package 12 consists of a plastic bag 14 and a food product contained therein such as frankfurters 16. The material of which the bag is made is generally thermoplastic so that the application of heat will plasticize it and the application of pressure will secure the plasticized parts to each other.

Table 10 is provided with a transversely extending slot 18 through which a pair of tubular members 20 and 22 project. These tubular members are `vertically disposed in parallel relation to each other and their lower ends are connected by conventional means, for example ilexible hose, and through valves V, if desired, to a vacuum pump. If desired, one of these tubularl members may be connected to a vacuum pump and the other to a selected fluid source maintained under pressure. illustrative would be an inert gas maintained in compressed form in a tank or a container of inert gas with a pressure pump to force it through said tubular member. Another possibility would be to secure said tubular member to a container of a suitable liquid preservative, such as a gelatinous material or a pickling juice or the like, and a pressure pump would be provided to pump said material through said tubular member. These various pumps, tanks, containers, inert gases and preservative materials are all conventional.

For the purposes of this specification, tubular member will be deemed to be connected in conventional manner to a conventional vacuum pump and tubular member 22 will be deemed connected in conventional manner to a conventional source of fluid under pressure, for example, a tank of compressed inert gas. This is purely illustrative and should not be understood as limiting the invention in any way whatsoever. If desired, both tubular members 20 and 22 could be connected to a vacuum pump but it is desired to illustrate the invention as being adapted to perform both functions above mentioned, namely, to evacuate a plastic bag and also, if desired, to fill it either with an inert gas or with a liquid food preservative or the like.

A frame 24 is secured to the bottom of table 10. A bracket 26 is secured to said frame 24 and mounted on said bracket is a pair of annular supports 28 and 30 respectively. Tubular member 20 is carried by said annular supports 28 and 30 and a collar 32 on said tubular member rests upon annular support 28 to prevent said tubular member from falling through said annular supports 28 and 30. It is clear that the two annular supports are in vertical registration with each other so as to support said tubular member 28 in a vertical position. The tubular member 2t) is free to turn about its own longitudinal axis in said annular supports for a purpose which will shortly be described. A radially extending pin 34 is secured to tubular member 20 and an extension spring 36 is secured at one end to said pin 34 and at the opposite end to a loop 38 on frame 24. Consequently, spring 36 will tend to urge tubular member 20 to turn in clockwise direction as viewed from the top of Fig. 2 or as viewed in Fig. 1.

A second bracket 40 is slidably mounted on frame 24. It will be noted in Fig. 3 that the lower marginal edge of frame 24 is bent upwardly to form a flange 24a and the upper edge is similarly bent downwardly to form a second flange 24h. These two flanges, also shown in Fig. 2, are spaced from the main body of frame 24 and they form channels with said main body of the frame to receive slidable bracket 40 and also fixed bracket 26 above mentioned. Bracket 40 is adapted to slide laterally in either direction within said channels formed between the main body of frame 24 and flanges 24a and 24h as the arrow in Fig. 2 clearly shows.

Annular supports 42 and 44 are mounted on slidable bracket 40 and it will be observed that tubular member 22 is mounted in said annular supports. Set screws prevent relative movement between the tubular member 22 and said annular supports 42 and 44. It will be noted that bracket 40 has a flange 46 formed thereon and said ange is provided with a tapped hole to receive a screw 48. Frame 24 has an end flange S0 which is disposed in parallel relation to flange 46 and flange 50 is provided with a hole which registers with the tapped hole in flange 46. Screw 48 projects through both holes and a knob 52 is secured to the outwardly projecting end of screw 48 adjacent flange 50. Collars 54 and 56 on screw 48 abut flange 50 on opposite sides thereof to prevent longitudinal movement of the screw. By turning knob 52 in one direction, bracket 40 is moved rightwardly and by turning the knob in the opposite direction said bracket is moved leftwardly. Since tubular member 22 is mounted on said bracket 40, it is in this manner that said tubular member may be moved laterally in either direction. A nut 58 on screw 48 may be tightened against flange 46 to lock the screw and flange against relative movement.

It will be observed in Figs. 1 and 3 that frame 24 is supported from table 10 by means of brackets 60 and 62 which are secured to said table. Plates 64 are secured to frame 24 and said plates 64 are hingedly secured to brackets 60 and 62 so that plates 64 are, in effect, hinge plates which enable the frame to pivot about a transverse axis. It will be seen in Fig. 3 and in Fig. 2 that extension springs 66 are diagonally disposed between frame 24 and table 10, the lower ends of said springs being hooked through flange 24a of said frame 24 and the upper ends of said springs being hooked through eyes 68 which are secured to table 10. The action of these springs is to draw frame 24 rearwardly, that is leftwardly and in clockwise direction as viewed in Fig. 3, for a purpose which will shortly become apparent.

lt will now be observed that the upper ends of tubular members 20 and 22 are bent over into substantially horizontal positions and they are flattened out and thereby widened to form nozzles 70 and 72 respectively. When a bag 14 is to be evacuated, it is placed on table 10 and slipped over nozzles 70 and 72 as Fig. 1 clearly shows. It is the pivotal movement of frame 24 in response to the action of springs 66 that tends to tilt the two nozzles upwardly so as to facilitate drawing the bag over them. It will now be recalled that tubular member 20 is angularly movable about its longitudinal axis and that spring 36 tends to turn it in one angular direction. It will now be understood that the angular movement of tubular member 20 is reflected in the corresponding angular movement of nozzle 70 since said nozzle is an integral part of said tubular member. In order to facilitate mounting the bag upon the two nozzles, it will be found helpful to swing nozzle 70 toward its dotted line position 70a shown in Fig. l, such movement being against the action of spring 36. Once the bag is mounted on the nozzles, nozzle 70 will be released and it will move back to its solid line position in Fig. 1 in response to the action of the spring 36 thereon. This will have the effect of holding the bag in a relatively taut condition, to prevent the formation of creases which might interfere with the sealing process hereinafter described.

It will now be seen that a rubber pad is mounted on table 10 immediately below the two nozzles 70 and 72. A second rubber pad 82 is mounted above said nozzles, being supported by a bar 84. Bar 84 is secured to a pair of arms 86 and 88 respectively and it will be noted that a pair of stud shafts 90 and 92 are secured to said arms 86 and 88, laterally thereof, and projecting in opposite directions. These two stud shafts 90 and 92 are axially aligned and they are mounted on a pair of bearings 94 and 96 respectively which are secured to table 10. It will now be understood that these two arms 86 and 88 are mounted for pivotal movement about the axis of said stud shafts 90 and 92 to move bar 84 toward and away from the two nozzles 70 and 72. Since rubber pad 82 is secured to bar 84, this is also the means for bringing said pad into and out of engagement with said nozzles.

Reference to Fig. 3 will disclose the fact that arm 86 has a downwardly projecting extension 86a and it will be understood that arm 88 has a similar downwardly extending portion. At their lower ends, these downwardly extending portions are pivotally connected to a foot treadle 98 whereby said downwardly extending portions may be pulled downwardly to elevate those ends of the two arms 86 and 88 to which bar 84 is secured. Springs 100 and 102 are connected at their upper ends to arms 86 and 88 and at their lower ends to table 10 and these springs act to pull the arms downwardly to bring rubber pad 82 into engagement with the bag mounted on nozzles 70 and 72 and thereby to swing the nozzles downwardly against rubber pad 80 and to squeeze the bag tight against said nozzles and against itself. This of course has the effect of sealing the open end of the bag so that the vacuum forming process may take place and also, if desired, the filling process whereby an inert gas or other fluid may be introduced into the bag. In other words, springs 100 and 102 are strong enough to overcome the action of springs 66 and to swing the nozzles downwardly against pad 80.

A second pair of arms 104 and 106 i-s provided with ring-shaped end portions 108. These ring-shaped portions are mounted on stud shafts 90 and 92 and enable said arms 104 and 106 to pivot on said stud shafts. The opposite ends of said arm- s 104 and 106 are secured to a crossbar 110 on which is mounted a knob 112. Crossbar 110 is a pressure bar used in heat sealing the bag. It will be observed in Fig. 3 that a heated bar 114 is embedded in table 10 a short distance behind rubber pad 80. This heated bar 114 has an electric heating element mounted therein to produce the necessary amount of heat to plasticize the bag for sealing purposes. It is embedded to avoid injury to the fingers of the person operating the device. When the bag is evacuated (and then, if desired, iilled with a suitable inert gas or other fluid) pressure bar 110 is moved downwardly to press the bag against the heated bar 114. The heat is suicient to plasticize the bag and the pressure is suicient to cause the plasticized portions of the bag to adhere to each other, thereby sealing the same. The packaging operation is now complete and treadle 98 may now be actuated to elevate bar 84 and arms 86 and 88 against the action of springs 100 and 102. Arms 104 and 106 are also connected to a pair of springs 116 and 11S respectively which are disposed between said arms and table 10. But these springs are of the compression variety and they act to elevate said arms 104 and 106 when knob 112 is released. Consequently, pressure bar 110 will release the bag and the bag will be free for removal from the apparatus thus described.

The foregoing is illustrative of a preferred form of this invention and it will be understood that this preferred form may be modiiied and other forms may be provided within the broad spirit of the invention and the broad scope of the claims.

I claim:

l. A mechanism for forming a vacuum in a bag containing a food product or the like, comprising a table for said bag, a resilient pad on said table, a pair of nozzles movably mounted above said resilient pad, said nozzles being horizontally aligned with each other and at least one of them being connected to a vacuum pump, a second resilient pad movably mounted above said nozzles, said nozzles being adapted to receive the open end of the bag and to hold it between said resilient pads, and means adapted to move the upper resilient pad into engagement with said open end of the bag and to press it together with the nozzles on which it is mounted into engagement with the lower resilient pad, thereby closing said open end of the bag and rendering it possible to form a vacuum in said bag through said nozzle which is attached to a vacuum pump.

2. A mechanism in accordance with claim 1, wherein each nozzle is a relatively flat, wide member readily adapted for insertion into a bag.

3. A mechanism in accordance with claim 1, wherein both nozzles are connected to a vacuum pump.

4. A mechanism in accordance with claim l, wherein one of the nozzles is laterally adjustable relative to the other nozzle toward each other to accommodate a relatively small bag and away from each other to accommodate a relatively large bag.

5. A mechanism in accordance with claim l, wherein one of the nozzles is swivelly movable about a vertical axis, a spring being connected thereto to urge said nozzle to swing in the direction away from the other nozzle and into engagement with the side of the bag, thereby drawing said bag relatively taut and to prevent the formation of creases.

6. A mechanism in accordance with claim l, wherein the upper resilient pad is secured to a pivotally mounted frame, a treadle being connected to said frame to pivot the same and thereby to move the upper resilient pad away from the two nozzles and the lower pad, springs being connected to said pivotally mounted frame to urge it to pivot in the opposite direction and to bring the upper resilient pad into engagement with the lower resilient pad and with the bag on said nozzles.

7. A mechanism in accordance with claim l, wherein a heated bar is embedded in the table and a presser bar is pivotally mounted above said heated bar and above the bag mounted on said nozzles, compression springs mounted between said table and said presser bar to urge the presser bar away from said bag and said heated bar, and mean-s for depressing said presser bar against the action of said springs to move it into engagement with the bag and to press said bag against the heated bar, whereby the bag is plasticized and sealed along the line of engagement with said heated bar.

No references cited.

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