US2709742A - Hand operated tool for application of heat seal label to package or container - Google Patents

Description

May 31, 1955 L. D. PERRY 2,709,742

HAND OPERATED TOOL FOR APPLICATION OF HEAT SEAL LABEL TO PACKAGE OR CONTAINER Filed Oct. 31, 1952 2 Sheets-Sheet l [0 INVENTOR. 9

Lorenzo D. Perry ATTORNEY May 31, 1955 ERRY L. D. P HAND OPERATED TOOL FOR APP TION OF HEAT SEAL LABEL TO PACKAGE CONTAINER Filed Oct. 31, 1952 2 Sheets-$heet 2 INVENTOR. v LarenzoDPerry ATTORNEY,

'Jnitecl States Patent 0 HAPJD oPnnArED ToOL FOR APPLICATION OF ring SEAL LABEL TO PACKAGE 0R coN- "ra an Lorenzo D. Perry, Faruham, N. Y.

Application October 31, 1952, Serial No. 318,022

3 Claims. (Cl. 219-21) and are characterized by a printed face and a face coated with a normally solid and non-tacky adhesive which is activated by heat.

The hand tools largely used heretofore for the application of labels of the heat seal type are electrically heated irons having terminal pressing shoes, for example an iron substantially similar in external form to that shown in the Lovice Patent No. 2,214,084 of September 10, 1940. Such irons are reasonably satisfactory when the heat seal labels are to be applied to paper but are not satisfactory when the labels are to be applied to thermoplastic sheets because they do not effect a secure or reasonably durable bond between the labels and the sheets. This objection is enhanced in degree when the labels are to be applied to packages composed of thermoplastic sheets which have just been removed from the storage chambers of refrigerating or deep freeze apparatus. Several factors contribute to this objection. Thus the degree to which the adhesive of the label is heated is not sufiicient to cause the surface of the thermo-plastic sheet to become tacky in any practical degree, and the smallness of the pressing area of the shoe as compared with the areas of most of the labels ordinarily used in connection with the rapidity with which the shoe is moved over the label is not conducive to the activation of the adhesive surface of the label simultaneously at all points or to an optimum degree. As a result the label has an unduly short shelf life and may be peeled or stripped without tearing the thermo-plastic material, a fact which enables an unscrupulous dealer readily to remove the labels of an original proprietor and substitute unauthorized labels which may misrepresent the source of origin or the quality of the product.

While the tool of the invention may be advantageously used for the application of labels of the heat seal type to any material it is of particular advantage in the application of such labels to thermo-plastic materials in sheet form suitable for use in the packaging of various products to be sold at retail. The invention takes advantage of the fact that the surfaces of such thermo-plastic sheets become viscid under a suitable degree of heat short of the charring point. As used in connection with thermoplastic sheets as packages for various products the tool of the invention has two aspects of utility viz. (l) for the application of the label and (2) for sealing the overlapping end portions of the thermo-plastic material in package form to cause their secure union, thereby to make the package substantially air and moisture proof, qualities of great practical value in the retailing of various food products The object of the invention is to provide a hand operated tool (1) in which the entire adhesive face of the label is activated prior to the pressing of the label upon Fatented May 31, 155

ice

the container and, as activated, is heated to a degree such that as pressed upon a container formed from a thermoplastic sheet it will simultaneously activate the underlying surface of the sheet whereby it becomes viscid and tacky, from which it follows that the label is bonded by fusion to the thermo-plastic sheet, the resulting union being secure in a degree which prevents stripping of the label and insures a relatively long shelf life, amply sufficient in connection with the sale of the product at retail; (2) which includes a part that may function as an iron and is highly heated simultaneously with the activation of the label and by the same heating element, this part being immediately available for activating the adjoining surfaces of the overlapping end portions of the thermoplastic container to cause their secure moisture and airproof union by fusion; (3} and by means of which the operations of applying the label and sealing the container as fashioned from a thermoplastic sheet may be easily and rapidly performed.

With the above objects in view a tool in accordance with the invention is characterized generally by a channel open at its upper and lower ends and provided by parallel spaced inner and outer plates, the inner plate having high capacity for heat conduction, through which channel the labels are fed with their adhesive surfaces adjacent the inner plat and subject to its heat, a roller which withdraws the labels from the channel and presses them upon the surfaces of the containers, a chamber which has one wall provided by the inner plate of the channel and an outer wall provided by an outer plate which serves as an iron, and electric heating element within the chamber for simultaneously heating both plates which provide the walls of the chamber and a handle feature by which it e tool can be positioned for the application of the label or for the use of the outer plate which provides a wall of the chamber as an iron for the package sealing operation above described.

The tool so characterized may be made in either of two forms, one of which utilizes a standard or conventional iron as designed for the application of heat seal labels to provide the heating element and the handle feature, the structure otherwise being the nature of an attachment which may be sold separately. and the other of which may be called an integrated or self contained form.

In the drawings:

Figures 1 to 4 show an embodiment in which the tool utilizes the shoe of a standard or conventional iron to provide the heating element.

Figure 1 is a perspective view of the tool showing the manner of its use in applying a label to a package.

Figure 2 is an elevation of the tool showing the manner of its use in sealing a package composed of a sheet of thermoplastic material.

Figure 3 is a sectional view of the tool in a central vertical plane extending in the direction of the movement of the tool upon the package or container.

Figure 4 is a fragmentary horizontal sectional view on the line 44 of Figure 3.

Figures 5 to 10 show an embodiment in which the tool is self-contained.

Figure 5 is a perspective view of the tool.

Figure 6 is a fragmentary vertical sectional view on the line 6-6 of Figure 5.

Figure 7 is an exploded perspective view with parts shown in broken lines of the three wall-providing plates of the tool and the spacing strips between the rear and intermediate plates.

Figure 8 is a horizontal sectional view on the line of Figure 5.

Figure 9 is a fragmentary elevation showing more particularly the arrangement of the openings and recesses for the terminal portions of the wires to which the heating coil is connected.

Figure 10 is a detail horizontal sectional view on the line 10-10 of Figure 9.

In the description which follows words signifying directions, e. g., horizontal, vertical, rear, front, and upper and lower are used as a matter of brevity and convenience with reference to the positions in which the parts are shown in the drawings.

Referring to Figures 1 to 4:

The standard iron which is utilized as a part of the tool is shown at I and has a handle H which provides the handle feature of the tool and a terminal shoe S which provides the heating element, the shoe being in the form of a flat metal casing (substantially as shown in the Lovice patent, No. 2,214,084 of September 1940) within which the heating element is enclosed.

The tool otherwise includes three metal wall-providing plates in parallel planes, namely a rear plate 1, an intermediate plate 2 and a front plate 3. These plates are connected in assembled relation by screws 4. The plate 3 is formed on its inner vertical face with a recess 5 which extends between its vertical end faces and is in cooperation with the intermediate plate 2 to provide a chamber in which the shoe S is fitted, the shoe occupying substantially the full extent of the chamber and the plates 2 and 3 providing the inner and outer vertical walls of the chamber. The upper and lower walls of the shoe are preferably in contact with the upper and lower walls of the recess 5 and the vertical walls of the shoe are parallel to and in contact with the adjoining vertical faces of the plates 2 and 3, the extent of the areas of contact, particularly between the shoe and the adjacent vertical faces of the plates 2 and 3, being such that these plates are readily and quickly heated to the temperature required for the purposes of the invention as above generally described.

The plates 1 and 2 are separated by vertical spacing strips 6 which are preferably attached to the plate 1 adjacent its ends and abut the plate 2. As thus spaced the plates 1 and 2 provide opposed outer and inner walls of a vertical channel 7 which is otherwise delimited by the strips 6, is open at its upper and lower ends, and is a Way through which the heat seal labels L are moved, the adhesive bearing faces of the labels being arranged adjacent the plate 2. The movement of a label L through the channel has an inward vertical component and a rearwardly directed horizontal component, the label of course progressively flexing as the direction of its movement changes from vertical to horizontal.

The plate 2 has a lower portion 8 which projects downward below the plates 1 and 3 and has a gentle rearwardly directed curvature, the portion 8 exercising a guiding function in which it initiates the rearward component of movement of the label during the course of its passage through the channel 7. The guide projection 8 cooperates with a roller 9 by which the label is applied to the package. The roller 9 is carried by and located rearwardly of the plate 1 and has at its ends suitable trunnions 10 which are journalled in rearwardly projecting ears 11 adjacent the lower edge of the plate 1, the cars 11 being integral with or otherwise rigidly attached to the plate. I11 their cooperative relation the projection 3 and the roller 9 delimit a curved label discharge throat 12 which is a functional downward and rearward continuation of the channel 7. The ideal position of the tool for applying the label L is shown in Figure 3. In this position the plate 1 is in a substantialy vertical plane and the lower horizontal edge of the guide projection 8 is quite close to the surface to which the label is to be applied and also quite close to the periphery of the roller 9. It is obvious that an absolute definition of quite close cannot be given but generally speaking the ideal spacing of the lower horizontal edge of the guide projection 8 from the periphery of the roller 9 and from the surface to which the label is to be applied is of the order of one-sixteenth of an inch.

The wires of the iron I at their free ends carry the conventional contact plug for engagement in a convenience outlet. In fitting the shoe S into the chamber provided by the recess 5, the screws 4 are initially backed off" to a slight extent to permit the shoe readily to be inserted into the chamber. When this has been done the screws 4 are tightened whereby the plates 1 and 2 exercise a secure clamping effect upon the shoe and the walls of the shoe are in the contact relations above described. The plate 2 is ideally of metal which has a high heat conducting capacity such as copper or aluminum.

The plates 2 and 3 become heated to the proper degree within a few moments after the tool has been connected to the convenience outlet. The dimension of the channel 7 between the plates 1 and 2 is several times the thickness of the label L whereby the label may be readily inserted into and moved through the channel. The operator inserts the label into the ripper end of the channel and pushes it down until its movement is resisted by the engagement of its lower edge against the curved surface provided by the guide projection 8. in this position within a small fraction of a second the adhesive face of the label is activated. The operator, using his finger, then taps the upper edge of the label to push its lower or leading edge through the throat l2 and under the roller 9. In the case of a relatively short label the upper edges of the plates 1, Z and 3 may be formed with recesses to provide a clearance 13 for the operators finger in tapping the upper edge of the label to push its leading edge through the throat 12, the extent of movement of the label in such tapping being comparatively slight whereby there is no liability of the operators finger striking the heated surfaces.

The tool, being maintained in the position of Figure 3, is then pushed over the package with the result that the roller 9, engaging the part of the label which projects from the throat l2 and by reason of the pressure which it exerts upon this part as positioned upon the package, pulls the label from the channel 7, and, tracking upon it the while, thereby applies it to the package. With reference to Figure 3 this movement of the tool for the application of the label is to the left as indicated by the arrow, the application of the label to the package being shown in Figure l.

The degree of heat applied by the plate 2 to the label is such that the adhesive surface of the label as activated approaches fluidity. Consequently there is no tendency of the label to adhere to the plate 2 and the movement of the label from the channel 7 as effected by the roller 9 is thereby relatively free. The heat of activation which brings the adhesive surface to this condition is stored, so to speak, in the adhesive material from which it is rapidly dissipated into the underlying surface of the package, this surface being at room tem perature or even cold when the package has just been removed from the storage chamber of a refrigerator or deep freezer. The stored heat is of a degree such that it causes the underlying surface of the package to become viscid and tacky with the result that the label is fused to the package, the union between the label and the package being exceedingly strong whereby the label may not be stripped from the package and its shelf life, that is to say the period of optimum behaviour of the adhesive, is relatively long and ample in connection with products to be sold at retail.

The roller 9 may be made of any suitable material, e. g. metal or rubber. When the roller 9 is made of metal the temperature at which it is maintained by the plate 1 is substantially less than charring temperature.

In addition to the application of the label to the package the tool is used for sealing the package. This may be done before or after the application of the wrapper. In this use the plate 3 functions as an iron, its outer side being placed in seam spanning relation against the adjacent overlapping portions of the wrapper sheet of thermo-plastic material as shown in Figure 2. In this sealing function the tool is simply moved along the ad jacent overlapping portions of the thermo-plastic sheet and heat is applied to the overlapping portions by the plate 3 which is heated to a degree to cause the confronting faces of the overlapping portions to become viscid and to fuse together, thereby to establish an air and moisture-proof seal. If the wrapping material of which the package is composed be other than thermoplastic material the package may, if desired, be sealed by applying to the adjacent overlapping edge parts of the wrapper a sealing strip of the heat seal type, the adhesive face of which will be activated by the heat transmitted from the plate 3 to cause the adhesion of the label to the adjacent parts of the wrapper.

Referring to Figures 5 to Whereas in the construction shown in Figures l to 4 the standard iron I provides the handle H of the tool and its shoe S provides the heating element in the construction shown in Figures 5 to 8 the heating element is built into the tool, so to speak, and the handle H is permanently connected to the tool. In other respects the tool is similar to the tool shown in Figures 1 to 4- and is used in precisely the same manner.

As shown in Figures 5 to l0 the tool includes thrc: metal plates 1a, 2a and 3a which respectively correspond functionally to the plates 1, 2 and 3 of the embodiment described and are also generally similar structurally. The plate 3a is formed with a recess 50 which is closed by the plate 2a to provide a chamber for the heating el meat 14. This may be of any suitable construction, e. g., of the substantial construction shown in Figure 3 of the patent to Lovice No. 2,214,084 which consists of mica plates between which flat resistance coils are fitted. The tool otherwise includes spacing strips 60 between the plates in and 2a and which correspond to the spacing strips 6. The plates 1a and 2a and the strips 6a delimit a vertical channel 7a similar to the channel 7 to which it corresponds functionally. The plate 2a is formed with a projection 8a similar in all respects to the projection. 8 and the plate 1 carries a roller 9a similar in all respects to the roller 9.

The handle H has an approximately central location relatively to the plate In and projects rearwardly from it. For the purpose of its attachment the handle H is formed with a terminal spider 15, the arms of which are secured to the plate In by screws 4a which otherwise correspond functionally to the screws 4. The arms of the spider are of channel form as shown in Figure 8, their edge faces bearing uniformly upon the plate in, and the arms of the upper pair in combination with the plate In provide conduits for the wires 16. The terminal portions of these wires extend through openings 17 and 18 in the plates 1a and 2a respectively and are positioned laterally beyond the channel 7a, for this purpose being accommodated in edge recesses 19 in the spacing strips 6a. Each vertical end wall of the recess 5a is formed at its upper end with laterally extending recesses 20. The recesses 20 accommodate the ends of the wires 16 to which the terminals of the heating coil are connected.

I claim:

1. A tool for the application of heat seal labels to sheet material as a container comprising, in combination, connected front, intermediate and rear metal wall-providing plates in parallel planes; spacing strips between the intermediate plate and the rear plate; the intermediate plate, the rear plate and the spacing strips delimiting a vertical channel open at its upper and lower ends and through which the label is moved with its adhesive side adjacent the intermediate plate; the front plate having a recess open to its inner face and the intermediate plate providing a wall of a chamber which is otherwise completed by the recess; an electrical heating element arranged within the chamber and supplying heat to the intermediate plate and the front plate; the intermediate plate as heated activating the adhesive face of the label and having a projection which extends downward from the front and rear plates and is gently curved in a rearward direction, the projection being a label guiding part; a roller carried by and located rearwardly of the rear plate; the label guiding projection and the roller delimiting a curved label discharge throat which is a downward rearward continuation of the channel; and a handle fixed in relation to and projecting angularly from the wallproviding plates; the roller being arranged in relation to the label guiding projection to engage a leading part of the label projecting under it and by cooperation with the surface of the container to which the label is to be applied functioning to withdraw the label from the channel, tracking upon it the while, and by pressure upon it to cause its adhesion by means of its activated adhesive face to the underlying surface of the container; the front plate as heated by the heating element being available as an iron for use in sealing overlapping portions of the container.

2. A tool as set forth in claim 1 wherein an iron which has a fiat electrically heated terminal shoe and an angularly projecting handle carrying the shoe provides the heating element by means of its shoe and provides the handle of the tool by means of its handle, the shoe being fitted in the chamber and clamped therein by the front and intermediate plates and having its vertical walls in contact with the adjacent vertical walls of the chamber.

3. A tool as set forth in claim 1 wherein the handle has an approximately central location relatively to the rear plate and projects rearwardly from it, the handle having a terminal spider, the arms of which are connected to the rear plate and are of channel cross section, the electrical heating element is connected to current conducting wires and the current conducting wires extend through arms of the spider and the plates have openings through which the terminal portions of the wires are passed for connection to the heating element arranged with the chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,123,415 Gorbatenko July 12, 1938 2,192,264 Kallander Mar. 5, 1940 2,372,737 Phillips, Jr. Apr. 3, 1945 2,538,520 Holt Jan. 16, 1951 2,613,310 Green Oct. 7, 1952

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