US2817937A

US2817937A - Packaging apparatus

Info

Publication number: US2817937A
Application number: US385056A
Authority: US
Inventors: John E Mcnamara; Charles A Sherman
Original assignee: Weyerhaeuser Timber Co
Current assignee: Weyerhaeuser Timber Co
Priority date: 1953-10-09
Filing date: 1953-10-09
Publication date: 1957-12-31
Anticipated expiration: 1974-12-31

Description

Dec. 31, 1957 J. E. MCNAMARA ETAL PACKAGING APPARATUS 2 Sheets-Sheet 1 Filed Oct. 9, 1953 INVENTORS John E.MNam are 6 yCharJeS HISher-man Dec. 31, 1957 J. E. M NAMARA ETAL 2, 9

PACKAGING APPARATUS Filed Oct. 9, 1953 2 Sheets-Sheet 2 INVENTORS John ENcNamara G yC'harJes fisherman Uetel swam :1

PACKAGING APPARATUS John McNamara-,Longvicw, niidCharles A. Sherman, Tacoma, 'Wash, assignors to Weyerhaeuser Timber (Zompany, Tacoma, Wash, a corporation of Washington v Applieatiou'octolir' 9, 1953, Serial No.395,06

6 Glfliins; 53-498) This invention relates to apparatus for packaging variousobjects; particularly bundles of lumber, by encircling therrr with lengths of thermoscnsitive adhesive material,

preferably'inthe for'm ofawtape, and then adhesivel-y uniting overlapped sections of the material by the simultaneous application ofhcat andpres'sure.

The primary objects of the present invention are to provide packaging apparatus:

(at) Whichsecureprbduct'sfor purposeszof economical transportation and storage, the package :beingreadily released, however, when its contents are to be used;

(1b) Which are applicablerapidly and easily to the packaging together of different sized andshaped objects such! as bundlesof-lumber designed for usein'the manuiactureoi knock-"down furniture;

(1;) which form packages whichareslidablc over each other :and which-.may be stacked uniformly without marringthe outside surfacesor corners of the packages;

(d) Which produce packages requiring butlittle more storage space than is required by the packaged objects alone;

(e) Wherein the packaging means may be used asa convenient medium! for the display oftrademarks, identifyingmarks, or directions, eliminating the necessity of-applying or including separate sheetsbearing this information;

( 1?)" In which the packaging mean-shoe: a low coefficient of exp ausion and does not loosen or tighten appreciably opment .of rust or-other corrosion products, or by the transfer of glue or other components to the/object packaged}.

(k) Which .dtonot require the use of heavy equipment andm-ay .betuse'dsubstantially universally in diverse plant operations where objects are to be packaged;

L-)- Which may be applied totl re. packaging ofgproducts having either has or. curved. surfaces; and

.(m) whereinthe packaging material may be maintained under tension for long periods of time without appreciable elongation .of the material or creeping of the seal.

The manner in which the foregoing and otherobiects of this invention are accomplished will be apparent lirom the" accompanying, specification and claims. considered. to-

gether with the drawings; wherein:

Figure 1 is a view in side elevation. illustrating the 2 basic construction of the presently described apparatus and its manner of use in packaging materials;

Figure 2 is a view infront' elevation of the apparatus illustrated in Figure 1, further showing its manner of use;

Figures 3 and-4 are plan and sectional views respectively of a tape which may bccmployed in the apparatus of Figures 1 and 2;

Figure 5 is aviewin side elevation partly in section, illustrating the presently described apparatus in another of its embodiments ina'firstposition ready for application to the packaging ofsmaterials;

Figure 6- is a view inside elevation :similar to Figure .5 butshowing the apparatus in a second position, at the conclusion of the packaging operation;

Figure 7 is a view iufront elevation of the apparatus of Figures 5 and 6; and

Figures 8 and 9 are detail sectional views taken respectively along the lines 8-8 and.9'9 of Figure 5.

Generally stated, the presently described packaging method comprises placing the .end of a length of flexible, thermosensitive adhesive material, preferably in the form of atape, against the object to be packaged, holding the end while wrapping the material about the object until it overlaps the held end, thereby maintaining the material under tension, holding the overlapped portions while sealing them by means of simultaneously applied heat and pressure, and then cutting off the trailing end of the material.

This method may be carried out using the novel apparatus illustrated. in- Figures 1 and 2. The apparatus is shown therein as it is applied to an object indicated generally at 10 which may comprise a single unit, as a box, or multiple units, as pieces of lumber. The apparatus comprises a handle portion 12 which preferably is generally U-shaped and provided with a pair of extensions 14, 16. Handle 12 also has means for guiding a length of thermosensitive adhesive material, preferably tape, therethrough.

In the illustrated form, the guide means comprise a first slot 18 passing through the front end of the handle and a second slot 20 angled through the rear end thereof, these slots being dimensioned to slidably receive a length of flexible binding material such as tape 24. The tape thus may be threaded through slot .20 over the top of handle 12', through slot 18, and forwardly to the apparatus for wrapping about the package.

Tape 24 may comprise any suitable form or composition of thermosensitive adhesive tape. It may be printed in any desired color and design and may bear any desired insignia as, for example, the trademark of the manufacturer. vA particularly suitable type is one having the construction illustrated in Figures 3 and 4. As shown therein, it comprises a plurality of threads 26 which may be made of cotton, linen, silk, wool, nylon, glass or the like, but which preferably are made of rayon. These are disposed side by side substantially parallel to each. other with the direction of the threads parallel to the lengthwise dimension. of the tape and embedded in a matrix 28 of heat sensitive resinous adhesive.

In general, the adhesive employed should be rapid setting, hard and non-tacky atambient temperatures, noustaining, non-creeping a'ndsubstantially unaffected dimensionally by temperature changes. Thus the melting point of the adhesive. should be. low enough to permit sealing of the packages. at a reasonable temperature, yet sufiiciently high to preventthe tapes on two adjoining packages from sticking together inv the event. they contact each other during stacking or storage in a warm place.

A. variety of heat. sensitive adhesives may be em ployed, either thermoplastic or 'thermosetting. Of the thermoplastic materials, polyvinyl acetate, polyvinyl chloride, the synthetic rubbers, the acrylate resins and the like are illustrative. Of the thermosetting resins, the thermosetting phenol-formaldehyde resins, the thermosetting urea-frmaldehyde resins, the melamine resins and the like are typical.

Means are provided in the presently described apparatus for hot pressing the tape during the packaging operation. Such means may comprise the pressing member 30, the pressing surface of which may be curved or flat, depending upon the surface contour of the objects to be packaged. It is heated by any suitable means such as an electric heating element supplied with current through electrical connector 32 and thermostatically controlled to operate at the temperature required to activate the tape. The current supplied'may be either alternating or direct and may have any suitable potential. The temperature level required depends upon the properties of the adhesive tape employed. When using a polyvinyl acetate-impregnated rayon material, a temperature of about 450 F. is suitable.

To protect the hand of the operator, a heat-insulating shield 34 preferably is interposed between the upper por' tion of the handle and the element. This may be fabricated of any appropriate insulating material, such as asbestos.

Cutting means are provided preferably as a self-contained part of the apparatus for severing the tape at the conclusion of the packaging operation. Such cutting means may comprise a knife 36 mounted on the front end of the apparatus with its cutting edge directed downwardly as viewed in the drawings. The knife preferably is hollowground, easily replaceable and easily resharpened.

For illustrative purposes, using objects which can be a encircled conveniently, one manner of operation of the presently described packaging apparatus as illustrated in Figures 1-4 is as follows:

First a thermosensitive adhesive tape, which preferably is of substantial length, and rolled on a reel, not shown, is threaded through guides 18, in the illustrated manner with the leading end of the tape projecting from the forward end of the apparatus. The latter then is held by the operator in one hand and placed beneath the object 10. The end of the tape is grasped by the operator in his other hand, as he reaches over the object, and pulled around a corner of the package in the manner illustrated in Figure 1. It is held there while the apparatus is withdrawn from beneath the package and placed over the top thereof. By this means the tape is subjected to tension by virtue of its being cinched around the corner, and while under tensionits free end is overlapped by a length of the tape in the apparatus.

The heated pressing unit then is pressed on the overlapped portions of the tape and held there for a time sufficient to activate the resin responsible for the thermo sensitive character of the tape. After the seal has been completed the apparatus is given a twist as a result of which the tape is severed by knife 36, leaving an un sealed tab projecting outwardly which is useful subsequently in unwrapping the package. This sequence may be repeated at several intervals along the length of the objedct until it has been secured as completely as desire Another embodiment of the packaging apparatus of this invention is illustrated in Figures 5-9. In this embodiment, means are provided for tensioning the tape as it is applied to the package, for preventing the tape from sliding back through the apparatus in a reverse direction, for compensating for misalignment of the handle and the package, and for cooling the tape after it has been hot-pressed, thereby increasing the speed of the packaging operation. 4 i

As is illustrated in the drawings, the apparatus of this embodiment as applied to the packaging of an object 40 1s provided with a handle 42 having

extensions

44, 46.

The handle may be longitudinally perforated to carry an electric cord 48. Its forward extension 44 is recessed and perforated at to enable mounting of tape tensioning means to be described hereinafter.

Attached to

extensions

44, 46 of the handle is a U- shaped bracket 52 which is apertured on opposite sides, the forward aperture being indicated at 54 in Figure 7. The base of the bracket has therethrough a longitudinal slot 56 and a pair of spaced apart openings 58, 60.

Pressing member 62 is connected to the bracket in such a manner that it may rock to vary its orientation relative to the handle, making possible uniform contact with the tape, even though the latter is placed upon an angular surface, or the apparatus is held by the operator in a position which is not precisely normal to the surface of the object being packaged. To this end the pressing member is provided with a pair of outwardly extending tabs 63, 64 adapted to extend through the openings 58, in bracket 52. The tabs are transversely perforated and penetrated by a pin 66 which releasably prevents their retraction through the openings.

Tabs 63, 64 also penetrate perforations in a perforated plate 68 interposed between bracket 52 and pressing member 62, and having an arcuate outer surface. The construction thus is such that the pressing member can rock to a limited extent on plate 68 so that it may be placed fiat on the tape irrespective of its position relative to the handle.

Cord 48 is connected to an electric heating element which is contained in pressing member 62 and maintains the element at the temperature level necessary to activate the thermosensitive tape. After such activation, the tape seal is cooled by means of a fiber plate or other cooling element 70 fastened to bracket 52 behind pressing member 62. Hence after the tape has been con tacted and heated by pressing member 62, it next is contacted and cooled by the relatively cool surface of the cooling member 70. This increases the efficiency and speed of the tape sealing operation.

In the embodiment of Figures 5-9 a flexible, thermosensitive adhesive material such as tape 72 is fed through the apparatus by means of a guide 74 which preferably is trough shaped and extends the entire length of the apparatus. It is slidably mounted by being positioned within the apertures in the opposite sides of the U-shaped bracket 52, one of these being indicated at 54 of Figure 7 as has been noted above. Also, it is provided with a forward lip 76 and a rearward lip 78 which assist in guiding the tape through the apparatus.

Rigid to guide 74 is a downwardly projecting extension 80 which penetrates slot 56 in the bracket. Attached to the lower end of the extension substantially at right angles thereto is an abutment 82, the position of which relative to extension80, is adjustable through the screw 84. Resilient means such as the spring 86 interconnect extension 80 and the forward leg of U-shaped bracket member 52 so that guide 74 normally is maintained in a forwardly extended position.

Tape tensioning means are associated with guide 74 to enable applying varying degrees of tension to the tape contained therein. In the illustrated form the tensioning means comprise a plunger 88 extending through the recess and perforation 50 in the forward extension 44 of the handle. The plunger is provided with a head 90 projecting a convenient distance outwardly from the surface of the handle and convenient to the thumb of the operator. It also is provided with a compression spring 92 seated in such a manner that the plunger may be pressed against the tension of the spring which therefore retracts the plunger from the tape when it is not desired to tension the same.

Means also are associated with guide 74 for braking the tape as it traverses the guide, permitting its travel in the forward direction only, when thisis desired. In the illustrated form the brake means comprises an eccentrically mounted brake member 94 which-is rotatable :about ing lever arm 98 by means of which it may be adjusted between active and inactive positions. In order tomaintain the brake member normally pressing against the surface of the tape, it is provided with an ear 100 by means of which it is connected to a post 102 through spring 104.

Means also are provided to cut oif the tape simultaneously with the cooling step at the conclusion of the packaging operation. One such means comprises a knife 106 mounted on a forward extension 108 of bracket 52 and operated by the same motion that is used in sealing the tape.

The operation of the apparatus illustrated in Figures 5-9 is as follows:

First, the apparatus is grasped by the operator in one hand and placed beneath the object 40 to be packaged. Next the leading end of tape 72 is grasped by the operator in the other hand as he reaches over the object and cinched about the near corner of the package. It is held there while the apparatus is transferred from a position beneath the object to a position superimposed above the object with abutment 82 placed firmly against the side thereof. This results in the overlapping of portions of the tape, the amount of overlap being determined by the position of the abutment relative to extension 80 on guide 74.

Next the pressing member 62 is placed against the overlapped sections of the tape. During this step it rocks on plate 68 as necessary to assume a fiat position on the tape irrespective of the position of handle 42. Since the pressing element is heated to a temperature necessary to activate the tape, it quickly forms a seal between the overlapped sections.

The apparatus then is moved forwardly with abutment 82 still pressed against the side of the object being packaged. This action accomplishes two results. First, it moves cooling element 70 across the heated surface of the tape, cooling it suificiently to set the adhesive. Secondly, it causes the retraction of guide 76 to the position of Figure 6 in which it no longer overhangs knife 106. The latter therefore is brought in contact with the taut tape and severs it, leaving an unsealed tab which is useful in removing the tape when required. During these operations the motion of the tape may be restricted to the feed direction by adjustment of brake 94, and the tension of the tape regulated by the application of pressure to plunger 88.

As a result of the foregoing procedure, the tape is sealed tightly about the article. The character of the seal is such that it is extremely resistant to longitudinal stress and thus resists the strain residing in the compressed package which normally tends to unwrap the package. However, the seal yields relatively easily to stress exerted perpendicular to the plane of the tape. Accordingly, by pulling outwardly on the projecting tab left after the cutting operation, the seal may be broken without the use of tools of any kind.

In this manner a remarkably efficient packaging of the article is secured with the use of a simple apparatus. The tape used may be applied rapidly and easily, and is attractive in appearance. It does not interfere with the subsequent handling of the package, since it lies flat and does not project in such a manner as to prevent uniform stacking of the package, or to mar the surface thereof. In addition, its small volume permits storage of a maximum number of packaged articles. Still further, the tape remains tightly applied to the packages even though there are severe changes in temperature. Then after it has been used and removed from the pack- .age, .it may either be destroyed by burning or spliced together andreu-sed.

It is to be understood that the forms of our invention herewith shown and described, are to be taken as preferred examples of the same, and that various changes in the shape,.size and arrangement of parts may be resorted to, without departing from the spirit of our invention, or the scope of the subjoined' claims.

Having thus described our invention, we claim:

1. Apparatus for packaging objects which comprises a handle, a pressing member on the handle, heating means associated with the pressing member for heating the same to a predetermined temperature, guide means on the handle for guiding a length of flexible thermosensitive adhesive material as it is Wrapped about the object, cooling means associated with the pressing member and substantially coplaner therewith for cooling the tape after it has been pressed by the pressing means, tensioning means positioned for tensioning the adhesive material as it traverses the guide means, brake means releasably engaging the adhesive material for permitting its travel in the feed direction only, and cutting means attached to the handle for severing the length of adhesive material after it has been wrapped about the object.

2. Apparatus for packaging objects which comprises a handle, a pressing member on the handle, heating means associated with the pressing member for heating same to a predetermined temperature, guide means associated with the handle for guiding a length of adhesive tape as it is wrapped about the object, tensioning means positioned for tensioning the tape as it traverses the guide means, brake means releasably engaging the tape for permitting its travel in the feed direction only, and cutting means attached to the handle for severing the tape after it has been wrapped about the object and pressed by the pressing member.

3. The apparatus of claim 2 wherein the tensioning means comprises a reciprocably mounted, spring-pressed plunger positioned substantially normal to the plane of the adhesive tape for bearing against the same as it traverses the guide means.

4. The apparatus of claim 2 wherein the brake means comprises an eccentrically mounted brake member positioned for releasable engagement with the tape as it traverses the guide means.

5. Apparatus for packaging objects which comprises a handle, a pressing member on the handle, heating means associated with the pressing member for heating same to a predetermined temperature, guide means on the handle for guiding a length of flexible adhesive material as it is wrapped about the object, slide means slidably mounting the guide means for longitudinal reciprocation with respect to the handle, and cutting means attached to the handle and positioned for engaging and severing the adhesive material upon reciprocation of the guide means.

6. Apparatus for packaging objects which comprises a handle, a pressing member on the handle, heating means associated with the pressing member for heating same to a predetermined temperature, guide means on the handle for guiding a length of flexible adhesive material as it is wrapped about the object with the ends in overlapped relationship preliminary to pressing them for adhesively uniting them, slide means slidably mounting the guide means for longitudinal reciprocation between advanced and retracted positions, an abutment connected to the guide means and positioned for engaging the object when a predetermined overlapping of the adhesive mate rial has been attained, and knife means connected to the handle and operable to sever the adhesive material when pressure is exerted by the abutmeiit against'the object, thereby sliding the guide means from its advanced to its retracted position.

ReferencesCited in the file of this patent 8 Bergstein Nov. 16, 1937 Diehl Feb. 3, 1942 Phillips Apr. 3, 1945 Dexter Oct. 13, 1953 Bennett Oct. 20, 1953