Bag Sealing Apparatus

Abstract

A bag sealer is provided for sealing plastic bags or the like, such as are used for sandwiches or other food items, and which are either of the conventional single-ply polyethylene type or are the so-called "boilable" two-ply bags which are comprised of an inner polyethylene layer and an outer Mylar layer. An elongated, rotatable and heat-conductive member having an electrical heating element and a pair of differently configured, bag-engaging surfaces is adapted to be selectively positioned to present either of the surfaces in a disposition for engaging the bag adjacent its open end and sealing the same by virtue of a cooperating pressure plate which is shifted toward the member to press the bag firmly against the hot sealing surface. One of the surfaces includes a planar, bag-engaging face which presents a relatively large area of engagement with the bag and is particularly suited for use with the two-ply "boilable" bags. A second surface of the member is provided with an elongated knife-edge that is ideally suited for sealing the open end of a conventional single-ply polyethylene bag and simultaneously trimming the latter as it is being sealed.

Description

This invention relates to a bag-sealing apparatus for sealing the open ends of plastic bags or the like and, more specifically, relates to those sealers which have found increasing popularity as an appliance in household kitchens. The utility of such an appliance is illustrated by calling attention to the increased use of plastic bags for the storing and preservation of food items. In the past, the bags have been used for individually wrapping sandwiches to prevent their becoming dry and stale before consumption, as well as for use as containers for the preservation of food as, for example, the freezing of various and sundry garden-fresh fruits and vegetables.

It is a well-established fact that much of the nutritional value of vegetables and the like is lost when the boiling water in which they are prepared is drained off. Recent technical improvements in the making of plastic bags has resulted in the development of the so-called "boilable" plastic bag in which the food to be prepared remains sealed in the bag during cooking and is not directly mixed with the water, therefore preventing their natural juices from becoming diluted by the boiling water. An example of the type of bag capable of withstanding cooking temperatures is one comprised of a conventional polyethylene inner liner or layer laminated with an outer Mylar layer to, in effect, present a two-ply plastic bag. The Mylar material withstands the higher cooking temperatures and does not melt as readily as the polyethylene material while the latter is better suited for its relatively low heat sealing characteristics.

It is, therefore, a very important object of this invention to provide an apparatus for sealing plastic bags and the like which is capable of sealing not only a conventional polyethylene bag, but which is also capable of sealing the heavier "boilable" bags such as those made of laminated layers of Mylar and polyethylene.

It is a further important object of my invention to provide a plastic bag-sealing apparatus in which a single heat-conductive member is utilized for the sealing of both types of bags and which may be easily and simply selectively positioned and held in either of two dispositions for engaging a respective type of bag.

Yet another important object of the invention is to provide a bag sealer having the capability of simultaneously sealing the open end of a polyethylene bag and trimming any excess material therefrom.

A still further significant object of the invention is the provision of a heat-conductive, bag-engaging member having a single heating means associated therewith which is optimally disposed relative to each of a pair of differently configured bag-supporting surfaces to provide that level of heat to each surface for properly sealing a corresponding type of bag.

It is a further object of my invention to provide a heating element which resists the adherence of any plastic that might have melted and spread thereinto.

In the drawing:

FIG. 1 is a perspective view showing the front and one end of a bag-sealing apparatus made pursuant to the present invention and illustrating a pressure means or plate in an open position such that the apparatus is in a condition for receiving a bag to be sealed;

FIG. 2 is an enlarged, fragmentary, vertical, longitudinal, cross-sectional view showing one end of the heat-conductive member with its mounting and an associated control knob.

FIG. 3 is an enlarged, fragmentary plan view illustrating the mounting of the opposite end of the heat-conductive member shown in FIG. 2;

FIG. 4 is a still further enlarged, fragmentary, vertical, transverse, cross-sectional view in which the heat-conductive member and cooperating pressure means are disposed in engagement with a "boilable" bag for sealing the same; and

FIG. 5 is a view similar to that shown in FIG. 4 and in which the heat-conductive member and a cooperating pressure means are disposed in engagement with a polyethylene bag for sealing and trimming the same.

A bag-sealing apparatus, broadly designated by the numeral 10, is comprised of a horizontally elongated base 12, an elongated, heat-conductive member 14 rotatably mounted on the base 12 and having a pair of differently configured, longitudinal surfaces 16 and 18 respectively, means 20 for imparting heat to the surfaces 16 and 18, and pressure means 22 shiftably mounted on the base 12. The base 12 may be constructed of any material suitable for appliances of this nature, such as plastic or the like, which is lightweight and economical in cost. An elongated cavity 24, disposed longitudinally in the base 12, receives the member 14, a front wall 26 of the base also forming the front wall of the cavity 24 and a rear portion 28 providing the rear wall of the cavity 24 as well as being the main body of the base 12.

The member 14 is supported by a pair of upright brackets 30 and 32 respectively, spaced longitudinally in the cavity 24 and affixed to a bottom wall 34 of the cavity 24 and the base 12. Stub shafts 36 and 38 are provided at opposite ends respectively of the member 14 and cooperate with their corresponding brackets 30 and 32 to support the member 14 between the brackets 30 and 32 in a manner to permit rotation of the member 14. The shaft 36, which extends outwardly from the bracket 30 a sufficient distance to pass through an end wall 40 of the base 12, is provided with a control knob 42 rigidly attached thereto.

The member or bar 14 which may be made of extruded aluminum, is provided with a longitudinal groove 44 in the surface 16 whereby a pair of spaced-apart, planar faces 46 are presented. Conversely, the surface 18 presents an elongated knife-edge which is angularly disposed relative to the surface 16 with its faces 46. It is to be understood that the knife-edge 18 and the faces 46 are essentially equal in length to that of the member 14.

The heating means 20 is in the nature of an electric heating element having an asbestos core 48 with a nichrome winding 50 and a silicone rubber cover 51. The element 20 is disposed longitudinally in the groove 44 such that its normally outermost surface is, for the most part, flush with the faces 46. The element 20 passes through a pair of holes 52 in the member 14 and is operably coupled with an electrical power supply (not shown) through the use of an on-off switch 54. Associated with the switch 54 is an indicator light 56 for purposes of showing when the element 20 is being heated.

Means for holding the member 14 against undesired rotation are in the nature of a tab 58 on each bracket 30 and 32 near the lower ends and on the rear edges thereof and a stop 60 on each of the brackets 30 and 32 on their forwardly facing edges proximal their upper ends. The tabs 58 and stops 60 extend from their respective brackets 30 and 32 toward one another in a manner to be engaged by and limit the rotational movement in either direction of the member 14.

The pressure means 22, which is in the form of a rectangular plate, is hingedly mounted on the base 12 with its axis of rotation parallel to the axis of rotation of the member 14 such that the plate 22 swings toward and away from the member 14 during movement. An elongated Teflon pad 62 is affixed to a normally downwardly facing side 64 of the plate 22 and is in a position to fully overlie the member 14 when the plate 22 is in its lowermost position.

In operation, at the time a "boilable" bag 66, as shown in FIG. 4, is to be sealed, the member 14 is selectively rotated to a position wherein the stops 60 engage the member 14 such that the surface 16 is facing upwardly. The bag 66, which is comprised of an inner polyethylene layer 68 and an outer Mylar layer 70 that have been fused together to form a bag having two-ply sides 72 and 74, is placed on the member 14 in a manner that the faces 46 and cover 51 transversely engage the one side 72 adjacent the open end of the bag 66. The remainder of the bag extends forwardly of the apparatus 10 in overlying relationship to the wall 26.

With the switch 54 in its "on" position, the heating element 20 becomes sufficiently hot to cause those portions of the polyethylene layers 68 nearest the zone of engagement of the faces 46 with the side 72 to melt and seal the bag as the plate 22 with its pad 62 is pressed into engagement with the other side 74 of the bag. Inasmuch as the Mylar layers 70 have a higher melting temperature than do the polyethylene layers 68, they do not melt.

Attention is also called to the ideal location of the heating element 20 relative to the bag 66 which results in maximum heat being available to penetrate the Mylar outer layer 70 for melting the inner polyethylene layers 68. The Mylar layer 70 keeps the melted polyethylene from spreading onto or sticking onto the member 14 and in addition, the silicone rubber cover 51 of the element 51 also prevents the sticking of any melted plastic that might inadvertently come in contact with the element 20.

Referring now to FIG. 5, the member 14 is shown as having been rotated to a position of resting on the stops 58 in such a manner that the knife-edge or surface 18 projects upwardly and in a disposition to engage a side 76 to a conventional polyethylene bag 78. The bag 78 is placed on the surface 18 in much the same manner as that described earlier for the "boilable" bag 66. The bag is sealed by virtue of the knife-edge 18 being heated by the conduction heat through the member 14 from the element 20 to melt the sides 76 and 80 of the bag 78 in the region of the bag's contact with the knive-edge 18. As was described in connection with FIG. 4, the plate 22 with its pad 62 is pressed into engagement with the side 80 opposite the zone of engagement of the knife-edge 18 with the side 76. Simultaneous with the heating and sealing of the bag 78 the downward pressure of the plate 22, indicated by the arrow 82, causes the knife-edge 18 to sever or trim away the excess material at the now sealed end of the bag 78.

As will be readily understood from the foregoing description, there is here presented a bag-sealing apparatus 10 which has, with a single heat-conductive member, the capability of sealing either a "boilable" bag, which requires a somewhat higher sealing temperature because of its construction, or a conventional polyethylene bag which does not require as high a temperature. It is but a simple matter to rotate the member 14 in order to selectively position the properly configured surface for the type of bag to be sealed and to proceed with the sealing operation without the need for further adjustments either with respect to the plate 22 or the heating element 20. Not to be overlooked also is the added feature afforded by the heated knife-edge in automatically trimming the excess material from the end of the polyethylene bag as it is being sealed.

It is to be understood that minor modifications may be made in the invention as described and illustrated without departing from the true spirit of this invention. Accordingly, the invention should be limited only by the fair scope of the following claims.

Claims

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for sealing the open end of plastic bags or the like, comprising:

a base;

an elongate member of heat-conductive material having a pair of differently configured surfaces, each of said surfaces being of length and configuration for continuous and uninterrupted spanning engagement with one side of a plastic bag or the like adjacent the open end thereof;

means rotatably mounting said member on said base for selective positioning of either of said surfaces in a disposition permitting said continuous, uninterrupted spanning engagement with said bag or the like;

means for heating said surfaces along the entire length thereof;

elongate pressure means of length at least that of said surfaces and shiftably mounted on said base for movement toward and away from the latter, said pressure means having a bag-engaging surface of generally planar configuration for continuous, uninterrupted spanning engagement with the other side of said bag or the like, oppositely to the zone of engagement between the latter and a selected one of said surfaces of said member.

2. Apparatus as claimed in claim 1, wherein there is provided means for holding said member against rotation during the time that said pressure means is in engagement with said other side of the plastic bag or the like.

3. Apparatus as claimed in claim 1, wherein said member is provided with a longitudinal groove, said heating means including an electrical heating element disposed in said groove.

4. Apparatus as claimed in claim 3, wherein said surfaces include a surface having a planar face.

5. Apparatus as claimed in claim 4, wherein said groove is in said last-mentioned surface to present a pair of spaced, planar faces.

6. Apparatus as claimed in claim 3, wherein said surfaces include a surface having an elongated knife-edge for trimming a bag or the like as the same is sealed.

7. Apparatus as claimed in claim 6, wherein said groove is below and in spaced relationship to said knife-edge when the latter is in a position to engage a bag or the like for sealing.

8. Apparatus as claimed in claim 7, wherein said surfaces are angularly displaced from each other.

9. Apparatus as claimed in claim 3, wherein said groove is in a first of said surfaces, and said element is disposed to engage said one side of the bag when the latter is placed on said first surface for sealing.

10. Apparatus as claimed in claim 9, wherein said element includes a silicone rubber cover.

11. Apparatus as claimed in claim 1, wherein a first of said surfaces presents a substantially greater area of engagement with said one side of a plastic bag or the like than does a second of said surfaces, said first surface being utilized for the sealing of bags or the like having multiple ply sides while said second surface is utilized for the sealing of bags or the like having single-ply sides.

12. Apparatus as claimed in claim 11, wherein said pressure means includes an elongated pad having an area of engagement with said other side of a plastic bag or the like and which is at least equal to the area of engagement of said first surface with said one side.