CA2359540A1 - Compact heat sealable bag dispenser and sealer - Google Patents

Abstract

In a preferred embodiment, a compact dispenser and sealer for heat sealable bags (20, Fig. 1), including: a housing (30, Fig. 1); apparatus (62, Fig. 1) disposed in the housing (30, Fig. 1) for selecting a desired bag length;
apparatus (Fig. 4) disposed in the housing (30, Fig. 1) for dispensing the desired bag length from a roll of heat sealable bag material (36, Fig. 4); and apparatus (220, Fig. 5) disposed in the housing (30, Fig. 1) for heat sealing an end of the bag (50, Fig. 1) as the bag is dispensed.

Description

Description Compact Heat Sealable Baq Dispenser and Sealer Technical Field The present invention relates to bags generally and, more particularly, but not by way of limitation, to a novel, compact, dispenser and sealer for bags formed of heat sealable material.
Background Art Heat sealable bags are widely used for the storage of materials. The materials can range from foodstuffs to small parts. There is known manually operated heat sealing equipment for home use for the storage of foodstuffs and also manually operated heat sealing machines used, for example, for forming bags to contain small parts to be sold in the bags. In both cases, one selects a bag of desired length, the bag having one end sealed and one end open, places the foodstuffs or small parts or etc. into the bag, and then places the open end of the bag into a heat sealer to form a sealed bag containing the materials. One problem with such manual sealing devices is that the heat seals are often not neat and consistent in appearance, one must in some cases guess as to how long to apply heat to the seal, and the seals may not be parallel to the ends of the bag.
In some cases, the user of the bags must inventory a number of bags of different lengths, resulting in unnecessary cost and the possibility of confusion and waste resulting from selecting a bag of the wrong length.
Also known are industrial machines for producing heat sealed bags from a roll of tubular material. These machines are typically large and heavy and are used principally to form bags of a given length in long production runs. The length of the bags produced can usually be changed; however, such changing is time consuming and is not practical for frequent changing of bag lengths produced.
A problem common with conventional machines that cut the bag material is that the machines employ hot wire cutters that produce undesirable smoke and odor.
A problem common with conventional automatic heat sealing machines is that the heat sealing element is difficult to replace when it burns out.
What is desirable is to have a bag producing machine that is compact and operator controllable to produce bags of different lengths and widths without complicated and time-consuming machine revisions.
Accordingly, it is a principal object of the present invention to provide a bag producing machine that is compact and portable.
It is a further object of the invention to provide such a bag producing machine that allows the operator thereof to be in control of the length (and width, if desired) of each bag individually and such control can be almost instantaneous.
It is an additional object of the invention to provide such a bag producing machine that produces bags with neat and consistent seals, parallel with the ends of the bags.
It is another object of the invention to provide such a machine that eliminates hot wire cutting of material.
It is yet a further object of the invention to provide such a machine in which the heat sealing element can be quickly replaced.
It is yet an additional object of the invention to provide such a machine that can be economically manufactured and is easily used.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.
Disclosure of Invention The present invention achieves the above objects, among others, by providing, in a preferred embodiment, a compact dispenser and sealer for heat sealable bags, comprising: a housing; means disposed in said housing for selecting a desired bag length; means disposed in said housing for dispensing said desired bag length from a roll of heat sealable bag material; and means disposed in said housing for heat sealing an end of said bag.
Brief Description of Drawings Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, submitted for purposes of illustration only and not intended to define the scope of the invention, on which:
Figure 1 is a perspective view of a dispenser and sealer for heat sealable bags, with one roll of tubular heat sealable material mounted therein.
Figure 2 is a perspective view of the dispenser and sealer for heat sealable bags, with two rolls of tubular heat sealable material mounted therein.
Figure 3 is a top plan view, partially cut-away and partially in cross-section, of the major internal elements of the dispenser and sealer for heat sealable bags.
Figure 4 is a side elevational view, partially cut-away and partially in cross-section, of the major internal elements of the dispenser and sealer for heat sealable bags.
Figure 5 is a side elevational view of the cutter and heater assemblies for the dispenser and sealer for heat sealable bags.

Figure 6 is a fragmentary side elevational view of the cutter and lower knife assemblies for the dispenser and sealer for heat sealable bags.
Figure 7 is a front elevational view of the upper knife for the dispenser and sealer for heat sealable bags.
Figure 8 is a front elevational view, partially cut-away and partially in cross-section, of a dual element heater bar block of the dispenser and sealer for heat sealable bags.
Figure 9 is a block diagram of a control system for use in the dispenser and sealer for heat sealable bags.
Best Mode for Carrvina Out the Invention Reference should now be made to the drawing figures, on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the views) on which the elements) being described is (are) best seen, although the elements) may be seen also on other views.
Figure 1 illustrates a dispenser and sealer for heat sealable bags, the machine being constructed according to the present invention, and indicated generally by the reference numeral 20.
Machine 20 includes a housing 30 in which is mounted a horizontal feed roll shaft 32 on which shaft is rotatably mounted a supply roll 34 containing a continuous tubular heat sealable material 36. A
flexible drag strap 40 has its proximal end 42 rotatably attached to a portion of housing 30 and is disposed over material 36 with a weight (not shown on Figure 1) attached to the distal end of the strap such that the strap acts as a drag to prevent undesirable rotation of supply roll 34.

WO 00/41931 PCT/i1S00/01230 As is described more fully below, machine 20 is provided to automatically dispense a bag 50 of selected length from supply roll 34 and heat seal one end of the bag. Bag 50 can then be manually removed from machine 20, small parts, for example, placed in the bag through the open end thereof, and then the open end of the bag is reinserted in the machine to heat seal the open end.
Machine 20 includes a plurality of pushbuttons 60 with which to enter the thickness of heat sealable material 36, the thickness setting serving as an input to the heat sealing control, a thicker material requiring a longer heat sealing time than a thinner material. Machine 20 also includes a plurality of pushbuttons 62 with which to select the length of bag 50, a plurality of pushbuttons 64, with which to select the roll from which bag 50 is to be dispensed when more than one roll is provided, a START pushbutton 66 with which to initiate the dispensing and sealing operation, a FEED pushbutton 68 that dispenses bag 50 as long as that pushbutton is depressed, and a SEAL pushbutton that initiates a sealing process. Completing the major elements of machine 20 visible on Figure l, there are provided a power switch 80, a lower guide 82, a removable or hinged cover 84, and two openings 86 and 88 defined through the cover to view operation of the machine.
Figure 2 illustrates machine 20 and the same elements as shown and described with reference to Figure 1, except in this case a second supply roll 100 is rotatably mounted on supply roll shaft 32 and contains a continuous tubular heat sealable material 110 having disposed thereon a flexible drag strap 112, similar in form and function to drag strap 40, with the proximal end 114 of strap 112 being rotatably attached to a portion of housing 30. It will be noted that material 36 is wider than material 110 so that a bag may be dispensed having a selected one of two different widths. Any number of supply rolls may be mounted on feed roll shaft 32 within the limits of machine 20.
Pushbuttons 64 are used to select from which of supply rolls 34 or 100 heat sealable bags will be dispensed and can be used to control any suitable electromechanical means to select from which roll to dispense heat sealable material, such as an electromechanical clutch/release mechanism (not shown) cooperating with feed roll shaft 32.
Reference should now be made to Figure 3 for a general understanding of the arrangement of the major internal elements of machine 20 (Figure 1) shown on Figure 3 in their non-dispensing positions. The major internal elements of machine 20 include a generally planar, horizontal base plate 150 with first and second, generally planar, vertical side plates 152 and 154, respectively, fixedly attached thereto. First and second side plates 152 and 154 are disposed inwardly of the vertical sides of housing 30 of machine 20 (Figure 1).
Feed roll shaft 32 is rotatably journaled in upwardly open, U-shaped, first and second bearing members 160 and 162, respectively, fixed to first and second side plates 152 and 154. Supply roll 34 is shown on feed roll shaft 32 and is held in place by means of a releasable clamp 170.
First and second pivot arm assemblies 180 and 182 are pivotally mounted, respectively, to first and second side plates 152 and 154 by means of a horizontal pivot arm assembly shaft 184 extending between the first and second side plates.
A bag drive motor output pulley 190 and a bag drive roller pulley 192 extend outwardly of second side plate 154, the bag drive motor output pulley driving the bag drive roller pulley by means of a continuous belt (not shown on Figure 3) extending therebetween. Bag drive roller pulley is fixedly mounted on bag drive roller shaft 200 that extends between first and second side plates 152 and 154 and rotation of the bag drive -roller shaft causes the a bag drive roller 202 fixedly mounted on bag drive roller shaft 200 to rotate. A bag pinch roller 210 is mounted generally above bag drive roller 202 on a bag drive roller shaft 212 and has its ends rotatably mounted in first and second pivot arm assemblies 180 and 182.
A heater assembly 220 is disposed horizontally between first and second side plates 152 and 154 near the inboard edge of lower guide 82, while a horizontal cutting assembly 222 is disposed inwardly of the heater assembly and extends between and is rotatably attached to first and second pivot arm assemblies 180 and 182.
First and second pivot arm assembly springs 230 and 232 extend between a horizontal spring shaft 234 fixedly attached to and extending between first and second side plates 152 and 154 and a spring return shaft 236 fixedly attached to and extending between a forward portion of first and second pivot arm assemblies 180 and 182.
Figure 4 illustrates the internal elements of machine 20 (Figure 1) as if second side plate 182 had been removed. It will be understood that, while second pivot arm assembly 182 is shown on Figure 4, an identical first pivot arm assembly 180 is positioned behind the second pivot arm assembly. Second pivot arm assembly 182 is shown in solid lines in its non-dispensing, or cutting, position and is shown in broken lines in its dispensing position in which material 36 may be dispensed by machine 20 to form bag 50.
First, it can be seen that distal end 240 of drag strap 40 has fixedly attached thereto a weight 242 and that the drag strap continues to engage material 36 as the roll of material is diminished in diameter. This arrangement is simple and keeps a fairly even drag pressure on roll of material 36.
Material 36 feeds from the bottom of supply roll 34 while pulling the supply roll in a clockwise direction as seen on Figure 4. Material 36 then passes over an idler roller 260 disposed between first and _g_ second side plates 152 and 154, along a plate 262 fixedly attached to the first and second side plates, past cutter assembly 222, through heater assembly 220, and exiting machine 20 between lower guide 82 and upper guide 264 to become heat sealable bag 50.
Operation of machine 20 (Figure 1) is initiated, after selection of length and thickness (and roll, if more than one roll is provided) by depressing START
pushbutton 66. This starts the following procedure.
The motive power for moving material 36 along the path described above is provided by supplying electrical power to a solenoid 280, centered between first and second side pivot arm assemblies 180 and 182, drawing a solenoid core 282 downwardly and, likewise, drawing downwardly a first link 284 rotatingly attached at its lower end to the distal end of the solenoid core. The upper end of first link 282 is rotatingly attached to a second link 284 and the latter motion causes this second link to rotate counterclockwise, as seen on Figure 4, about a shaft 286 fixedly disposed between first and second side plates 152 and 154. This motion draws downwardly a rod 290 fixedly disposed between first and second pivot arm assemblies 180 and 182 and engaging a lower surface of second link 284, thus causing the first and second pivot arm assemblies to rotate clockwise, as seen on Figure 4, about pivot arm assembly shaft 184 to the position shown in broken lines. The pivoting of first and second pivot arm assemblies 180 and 182 raises cutter assembly 222, fixedly attached to the first and second pivot arm assemblies, to permit material 36 to pass thereunder and lowers bag pinch roller 210 to create a nip between the bag pinch roller and bag drive roller 202. Now, when drive motor output pulley 190 is rotated counterclockwise by a motor associated with gear box 310 mounted on adjustment plate 312, continuous belt 314 will cause bag drive roller pulley 192 and bag drive roller to rotate counterclockwise, drawing material 36 to the left as seen on Figure 4.

_g_ When the desired length of bag 50 has been dispensed, drive motor output pulley 190 ceases rotating and power is removed from solenoid 280. The latter causes first and second pivot arm assembly springs 230 and 232 to rotate first and second pivot arm assemblies 180 and 182 counterclockwise, as seen on Figure 4, about pivot arm assembly shaft 184, lowering cutter assembly 222 which causes the cutter assembly to slide against lower knife assembly 330, thus shearing material 36.
Before material 36 is cut to the desired length, electrical power applied to heater seal bar drive 340 causes a continuous belt 342 to rotate a first cam assembly 344 which initiates the bag sealing operation described below.
Figure 5 illustrates heater assembly 220. Heater assembly 220 includes first cam assembly 344 that is fixedly mounted on a cam assembly shaft 360 rotatingly attached to and extending between first and second side plates 152 and 154. Cam assembly 344 is adjacent first side plate 152 and a second, similar cam assembly is disposed adjacent second side plate 154. Cam assembly 344 is provided to drive downwardly an elongated, horizontal heater seal bar 370, biased upwardly by a spring 372, to press an end of bag 50 against a heater bar 374. Heater bar 374 has its upper surface covered with a patterned teflon tape to impart a complementarily shaped pattern to the sealed area of bag 50 so that it does not fall out of machine 20 after the sealing and cutting operation. The teflon tape also protects heater bar 374. Heater bar 374 is disposed in a heater bar block 380 the details of which are described below.
As is indicated above, heat is applied for a time sufficient to seal bag 50, the time depending on the thickness of material 36, with thicker materials having a longer sealing time than thinner materials. After heat is applied, heater seal bar 50 is left in place against the upper surface of the sealed area of bag 50 for a brief period of time to permit a degree of cooling. After the cooling period, heater seal bar is raised and bag 50 can be manually removed from machine 20. Then, for example, parts can be placed in bag 50, the open end of the bag is inserted in machine 20 between upper exit guide 264 and lower exit guide 82, with the upper end of the bag against cutter assembly 222 which is in its lowered position when material 36 is not being dispensed, and SEAL pushbutton 70 (Figure 1) is depressed to start the sealing operation to seal the open end. Alternatively, a foot switch (not shown on Figure 5) may initiate the second sealing step to as to leave free the hands of the operator. Having a stop for the open end of bag 50, in this case cutter assembly 222, assures that the second seal is parallel with the ends of the bags. The "stop" is approximately one-half-inch from the portion of the bag to be sealed. Re-insertion of bag 50 in machine 20 is facilitated by upper and lower guides 264 and 82.
Figure 5 also illustrates cutter assembly 222.
Cutter assembly 222 includes a generally vertical upper knife 400 to which is fixedly attached an upper knife guide 402. Upper knife guide 402 is narrow and is disposed at the end of upper knife 400 adjacent first side plate 152. The outer surface of upper knife guide 402 rides on a roller 410 that is rotatingly attached to first side plate 152 to guide cutter assembly 222 as it moves up and down.
Figure 6 illustrates cutter assembly 222 and lower knife assembly 330 and shows the function of roller 410 as cutter assembly 222 is moved from its dispensing, raised position (solid lines) to its lowered position (broken lines) after having cut material 36 (not shown on Figure 6). Since cutter assembly 222 is fixedly attached to first and second pivot arm assemblies 180 and 182, the cutter assembly rotates as the pivot arm assemblies rotate. Cutting of material 36 is effected by the lower edge of upper knife 400 sliding against the forward edge of a lower knife 420 fixedly mounted on lower knife mounting block 422 and extending along the upper knife. Mounting block 422 is pivotally mounted on a shaft 430 extending between first and second side plates 152 and 154 and is biased forwardly, that is toward upper knife 400, by means of a spring-loaded plunger 432 disposed for axial movement in a plunger mounting block 434 fixedly attached to first side plate 152.
Figure 7 illustrates upper knife 400 and shows that cutting edge 440 thereof tapers upwardly from the end of the upper knife adjacent first pivot arm assembly 180 to the end of the upper knife adjacent second pivot arm assembly 182. Figure 7 also shows more clearly upper knife guide 402 fixedly attached to the front surface of upper knife 400.
Figure 8 illustrates heater bar block 380 and shows that the heater bar block has heater bar 374 disposed along the upper surface thereof and has an identical spare heater bar 450 disposed along the lower surface thereof. The present invention addresses the problem of difficulty in replacing burned out heater bars by providing heater bar block 380 having dual elements. Electrical power is furnished to heater bar 374 through wires 460 and 462 operatively connected to a receptacle block 464 fixedly mounted on first side plate 152. When heater bar 374 burns out, mounting screws 470 and 472 are removed and heater bar block 380 is unplugged from receptacle block 464 by withdrawing the heater bar block through an opening 480 defined through second side plate 154. Heater bar block 380 is then rotated 180 degrees with respect to its major axis, rotated end for end, reinserted into opening 480, replugged into receptacle block 464, and mounting screws 470 and 472 are reattached. Heater bar 450 is now on the upper surface of heater bar block 374 and is supplied electrical power through wires 490 and 492.

As seen on Figure 8, heater bars 374 and 450 are supported by, and attached to, at the left ends thereof a fixed support block 494 and are supported by, and attached to, at the rights ends thereof a sliding support block 496. To accommodate expansion and contraction of heater bars 374 and 450 as they heat and cool, a biasing spring 498 is provided between sliding support block 496 and a fixed block 499 to maintain tension on the heater bars.
Figure 9 illustrates a control system for machine (Figure 1), the control system being generally indicated by the reference numeral 500. Control system 500 includes a microcontroller 510 that is desirably located in housing 30. Microcontroller 510 receives 15 inputs of selected material thickness, selected bag length, selected supply roll, START, and an input from a foot switch 520 that may be provided to initiate bag dispensing and/or for providing a signal to initiate sealing of the open end of the bag. The selection 20 inputs may be provided by means of depressing selected ones of pushbuttons 60, 62, 64, 66, and 70 (Figure 1).
Microcontroller 510 provides outputs to the roll selection mechanism, the solenoid, the drive motor, and the heater. A remote controller or computer or the like 530 may be provided operatively connected to microcontroller 510 to control certain functions of machine 20 and/or to monitor operation of machine 20.
Machine 20 offers a number of advantages over conventional means for forming bags of varying lengths and widths. First, machine 20 is of "table-top" size, is relatively light, and is very portable. Housing 30 is on the order of the size of a conventional typewriter and machine 20 weighs less than about 50 pounds.
Cutting with a knife eliminates the hot wire typically used to cut bag material, the hot wire generating undesirable smoke and odor.

The operator is in control of the length (and width, if desired) of each bag individually, since the length and width can be chosen for each bag. If material on different rolls have different thicknesses, thickness can also be a chosen parameter.
Machine 20 produces bags with neat and consistent seals, parallel to the ends of the bags. Pre-selection of heating time facilitates uniform sealing.
Any heat sealable material can be used with machine 20. The material may be clear, opaque, colored, pre-printed, anti-static, or any combination of these, for example. Printing may be placed on the bags as they are dispensed.
The heating element in machine 20 can be easily and quickly replaced.
In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown.
Terms such as "upper", "lower", "inner", "outer", "inwardly", "outwardly", and the like, when used herein, refer to the positions of the respective elements shown on the accompanying drawing figures and the present invention is not necessarily limited to such positions.
It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims (7)

Claims

1. A compact dispenser and sealer for heat sealable bags, comprising:
(a) a housing;
(b) means disposed in said housing for selecting a desired bag length;
(c) means disposed in said housing for dispensing said desired bag length from a roll of heat sealable bag material; and (d) means disposed in said housing for heat sealing an end of said bag as said bag is dispensed.

2. A compact dispenser and sealer for heat sealable bags, as defined in Claim 1, wherein: said selected length is produced by cutting said heat sealable material with a knife blade.

3. A compact dispenser and sealer for heat sealable bags, as defined in Claim 1, further comprising: means disposed in said housing for selecting a desired bag width.

4. A compact dispenser and sealer for heat sealable bags, as defined in Claim 1, further comprising: means disposed in said housing for selecting a desired bag material thickness.

5. A compact dispenser and sealer for heat sealable bags, as defined in Claim 1, wherein: said means for heat sealing includes a first heating element disposed in a heating element block containing a spare, second heating element, said second heating element being placeable in service by repositioning said heating element block within said compact dispenser and sealer for heat sealable bags.

6. A compact dispenser and sealer for heat sealable bags, further comprising: an external foot switch connected to provide a control input to said compact dispenser and sealer for heat sealable bags.

7. A compact dispenser and sealer for heat sealable bags, wherein: said compact dispenser and sealer for heat sealable bags is portable, weighs less than about 50 pounds, and has dimensions approximating those of a standard typewriter.