US2385583A - Machine for sealing waxed paper bags - Google Patents

Description

Sept. 25, 1945.

I A. B. M LAUCHLAN 2 ,385,583

MACHINE FOR SEALING WAXED PAPER BAGS Filed May 18, 1942 2 Sfieets-Sheet 1 B. Mc.LAUCHLAN INVENTOR.

' Armmvsrs 1945- A. B. MCLAUCHLAN 2,385,583

MACHINE FOR SEALING WAXED PAPER BAGS Filed May 18, 1942 2 Sheets-Sheet 2 ATTORNEYS Patented Sept; 25, 1945 MACHINE FOP SEALING WAX-ED PAPER mos Arthur B. McLauchla-n, Salem, Oreg. Application May 18, 1942, Serial No. 443,431

2 Claims.

This invention relates in general to devices for sealing the open ends of bags containing foodproducts, or other materials, where the sealing is to be accomplished by means of heat and pressure.

More specifically, this invention relates to ma-' chines for sealing waxed paper bags containing food products, such as fresh berries and the like, which are subjected to quickfreezing or sharp freezing," such freezing of the products for their preservation taking place immediatelyafter the bags have been completely sealed; and this invention relates in particular to the customary packaging of frozen fruits or other foods in which a waxed paper bag is placed as a liner in an open carton, then filled with a food product and sealed, after which the carton is closed and the entire package then subjected to the freezing process and kept in a freezing temperature.

A number of devices and machines have been invented for heat-sealing waxed paper bags used for such packages, but most of these are more or less complicated and are expensive to build and to maintain.

An object of this invention is to provide an improved sealing machine which will be comparatively simple in construction and require a minibetween the heat-Dressing elernents-for example,

when extra folds have been inadvertently made in the open bag ends to be sealed-the extra thicknesses of the waxed paper clog and jam between the heat-pressing elements," damaging the package in question and temporarily delaying further functioning of the device. An important object of my present invention, accordingly, is to avoid this difiiculty by providing heating-pressing elements of rollers which will be automatically adjusted to accommodate extra thicknesses of paper without interfering with their normal operation. This latter object I accomplish by employing heated rollers for the pressing elements and by having one of the rollers adjustably springmounted.

Another problem encountered when heatingpressing elements are employed for sealing such bags is involved in maintaining just the right amount of pressure, inasmuch as too great a pressure, especially if grooved sealing rollers are used, might damage or tear the waxed paper, while too little pressure might not produce a perfect seal.

A further object of this invention is to provide adjusting means whereby the sealing pressure may be modified as required and maintained at constant predetermined, but adjustable, amount at all other times.

It is also desirable that the packages or cartons should be marked at the time of sealing to indicate thelot or operators number, so that should any package later be found to be imperfectly sealed it can be traced for the purpose of ascertaining the probable cause of the imperfect sealing. A still further object therefore is to provide suitable meansfor marking the package or carton at the time of sealing.

These and other objects I accomplish by making my sealing machine in the manner hereinafter briefly described with reference to the accompanying drawings.

' In the drawings:

Fig. 1 is a side elevation of my improved machine with a waxed paper bag and its carton container shown in broken lines;

Fig. 2 is a front elevation of the same machine;

Fig. 3 is a fragmentary plan view of the forward end of the machine, with portions broken away for the sake of clarity and with a portion shown in plan section, the figure corresponding to the line 3--3 of Fig. 2; and

Figs. 4A and 4B are fragmentary views of the meshing gears connected to the heating pressing rollers, illustrating respectively the positions of the gears when-ordinary and when extra thicknesses of waxed paper are being sealed.

The machine includes a pair of horizontal plates comprising bottom plate In and top plate II which are adjustably secured in parallel spaced relation by a plurality of vertical rods l2. These rods preferably have both ends threaded, as shown at Figs. 1 and 2, and pairs of clamping nuts 12 are mounted on the threaded ends of the rods so as to enable the rods and plates to'form a rigid but adjustable machine frame.

A pair of parallel guides 3 are supported on the bottom plate l0 and extend longitudinally through the machine for the purpose of guiding the cartons I! containing the paper bags to be sealed.

i'I'hese guides I 3 are adjustably secured to the bottom plate ID by screws or bolts I I. (Fig. 3) ex- I tending through slots I 5 in plate I 0 and thus enable the guides" to be placed further apart or closer together to accommodate larger or smaller cartons. A conveyor belt l8, mounted on suitable rollers (not shown) and driven in any suitable manner, conveys the filled cartons through 1. The forward ends of the guides l3 are flared outwardly as shown at l4 in Fig. 3 to facilitate the proper positioning of the cartons on the conveyor belt.

.the machine from left to right as viewed in Fig.

bottom plate 60 and is connected at its lower end to suitable driving means (not shown) by which rotation is imparted to the shaft 2i and roller H. A gear 26 is attached to the shaft 2| above the hub 23.

w The other heat-pressing roller is secured at the bottom end of a shaft 26 which is rotatably supported in a U-shaped bracket 21 extending through a suitable slotted opening in the top plate II.

This U-shaped bracket 2'! has a pair of horizontal arms 28, one located above and one below the plate II, which are mounted on a stub shaft 29 supported in a hub 3|). Thus the U-shaped bracket 27, and therewith the shaft 26, are movable in a horizontal arc, thereby permitting the position of the roller 20 to be varied with respect to the roller IS, the axis of the roller l9 being fixed. A

gear 25 is attached to the shaft 26 above the U- shaped bracket 21 in such position as to mesh with the gear on the shaft 2 I.

In order to hold the roller 20 normally in a desired position with respect to the companion roller I 3, I provide adjustable means at opposite sides of the bracket 21 as shown in Figs. 3 and 2. This means includes a stop screw 34, adjustably positioned in a lug 35, the purpose of which is to determine the minimum spacing between the rollers I have found that, in sealing waxed paper bags,

especially when fluted or serrated rollers are used, it is best to provide a slight spacing between the rollers-corresponding approximately to, but not exceeding, the thickness of two sheets of the waxed paper. Thus it will be noted in Fig, 2 that the rollers l9 and 20 are spaced apart approximately the thickness of the bag end l8 to be sealed, that is, the thickness of two sheets of the waxed paper. This spacing is of course adjustable by means of the stop screw 34. In the event that extra thicknesses of the waxed paper, due to any extra folds in-the' waxed paper bag or to any other causes, are forced between theheatpressing rollers l9 and 20, the spring 3| will automatically permit the spacing between the rollers to be sufficiently increased to compensate for the extra thickness of the waxed paper, thus preventing any clogging or jamming of the paper between the rollers, and the adjusting screw 32 can be set so as to provide just the right amount of spring pressuredesired for such extra thicknesses of the waxed paper. Even under-unusual circumstances, however, the variation of the paper thickness will be relatively so small that the gears 24 and 25 (Figs. 2 and will continue to remain in mesh even though the spacing between the heat-pressing rollers is temporarily increased.

The shafts 2| and 26, to which the rollers l9 and 20 are attached, are hollowed out to permit heating elements to be inserted for the purpose of heating the pressing rollers. Electrical heating elements 36 are placed in the hollowed shafts and are connected respectively to pairs of ring conductors 31 mounted at the top of each shaft. Wiper contact arms 38, secured to a binding post 39, conduct electricaLcurrent, obtained from a suitable source, to the heating elements in the usual manner.

Before sealing the tops of the waxed paper bags, it is desirable to exhaust most'of the air from the filled bags, and this is very simply done in my machine by pressing down slightly on the bags on both sides of the flattened wall surfaces which are to be sealed. For this purpose I provide a pair of pressing guides 40 extending longitudinally into the machine at the forward end. The for-. ward ends of these guides 4| are flared outwardly and upwardly, as shown in Figs. 2 and 3. I have found it also desirable to have these guides 40 I inclined transversely slightly from the horizontal,

as shown in Fig. 2, to conform more to the natural slope of the contents in the bags at the-top. Furthermore, these guides are also adjustably mounted and are supported from the top plate II by rods 42 which have threaded ends for the adjustable clamping nuts 42. This adjustable feature enables cartons and bags of slightly different sizes to be used in the machine. guides 40 not only exhaust most of the air from the tops of the bags before the sealing, but also aid in guiding and positioning the flaps or tops of the side walls of the waxed paper bags for the pressing-heating-sealing operation performed by the rollers l9 and 20.

The cartons or containers H, in which the bags are placed before being filled, have customary lids 43 which are folded over in the usual manner after the sealing of the bags has been completed. While the bags are being sealed in the machine, the carton lids must be kept out of contact with the heated. sealing rollers, and for this purpose, and also for the purpose of placing identification marking on the carton lids, I provide two pairs of horizontal lid guides 43 and 44, the upper pair 43 being adjustably supported from the top plate II and the lower pair 44 being adjustably supported by the bottom plate It). Both of these pairs of carton lid guides are secured to-rods 45 which have their opposite ends threaded to accommodate the adjustable clamping nuts by which they are attached to the upper and lower plates of the machine frame. These pairs of guides thus hold the carton lid in horizontal position removed from the heat-pressing rollers while the sealing of the bags is taking place, and guide the carton lids to an identification stamping means which is provided at the rear of the machine.

The stamping of the carton lids is performed 'by a stamping assembly including a base member 41 (Fig. l) on which are mounted removable in-' dicia 48 for the purpose of placing any desired These wardly thereof. said guides acting to bring the top packers number, etc. Since cartons in which frozen foods and other similar products are packaged generally have a waxed coating, the base member 47 is heated in order that heat may be conducted to themarking indicia 48 to enable the identification marking to penetrate the waxed surface of the carton lid. This heating is obtained through the medium of an electric heating element placed in the base member 41 and connected to a suitable source of electric current.

As the lid it of a carton passes over the heated indicia 48, a plunger plate 49, attached to the bottom of a plunger rod 50, presses the carton lid down against the heated indicia 48 for a slight instant. The plunger rod 5ll'is actuated by a pivoted offset arm 52. The opposite or forward end of the offset arm is arranged to be engaged by cam segments 55 located on the top face of the gear 26. A spring 55 normally retains the plunger rod 50, and therewith the rear end of the offset arm 52, in raised position, and holds the forward end of the offset arm 52 against the top surface and cam elements of the rotating gear 24. The ofiset arm 52 is pivotally mounted in a pair of supports 54 by means of a shaft 53. Should no marking of the carton be desired, the base member .41 and the plunger rod 50 can be removed from the machine.

I claim:

1. A machine for heat-sealing waxed paper bags including a pair of top and bottom plates, 9. pair of heating pressing. rollers mounted on vertical shafts and located below said top plate, the shaft for one of said rollers supportedin a bearing on said top plate, the shaft for the other roller supported in a hinged bracket pivotally mounted on said top plate and adapted to swing in a horizontal plane, means for positioning said bracket and second mentioned shaft whereby to control the spacing between said rollers, said latter mentioned means including a positive, ad- J'ustable stop for maintaining a predetermined minimum spacing between said rollers and a resilient element normally holding said bracket against said stop but allowing said minimum spacing to be temporarily increased to accommodate extra thickness of waxed paper passing between said rollers, means for heating said rollers, means for rotating said rollers, a pair of longitudinally extending pressing guides located below said rollers, and extending forwardly and rearflaps of each bag into position in preparation for the heat sealing and to cause air to be exhausted from said bags by pressing down on said bags prior to and during the sealing, said guides sup-v ported from said top plate, conveying means supported on said bottom plate for conveying said bags through said pressing guides and pressing rollers, and means for adjusting the position of said top plate with respect to said bottom plate,

whereby bags of difierent size can be accommodated in said machine merely by adjusting the position of said top plate with respect to said .bottom plate.

2. A machine for heat-sealing waxed paper bags comprising a pair of top and bottom plates, a pair of heating pressing rollers mounted on vertical shafts and located below said top plate, the shaft for oneoi said rollers supported in a fixed bearing on said top plate, the shaft for the other roller supported in a hinged U-shaped bracket pivotally mounted on said top plate and adapted to swing in a horizontal plane, means for positioning said bracket and second mentioned shaft whereby to control the spacing between said rollers, said latter mentioned means including a positive, adjustable stop for maintaining a predetermined minimum spacing between said rollers and an adjustable spring normally holding said bracket against said stop but allowing said mini-- mum spacing to be temporarily increased to accommodate extra thicknesses of waxed paper passing between said rollers, meansfor heating said rollers, means for rotating said rollers, a

pair of longitudinally extending pressing guides located below said rollers, and extending forwardly and rearwardly thereof, said guides acting to bring the top flaps of each bag into position in preparation for the heat sealing and to cause air, to be exhausted from said bags by pressing down on said bags prior to and during the sealing, said guides adiustably supported from said top plate. conveying means supported on said bottom plate for conveying said bags through said pressing guides and pressing rollers. and means for adlusting the position of said top plate with respect to, said bottom plate, whereby bags of different size can be accommodated in said machine merely by adjusting the position of said top plate with respect to said bottom plate.

ARTHUR B. McLAUCHLAN.

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