US3011688A

US3011688A - Dispensing container

Info

Publication number: US3011688A
Authority: US
Inventors: Walter A Klein; Albert J Mason; Holzschu John
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1958-01-20
Filing date: 1958-01-20
Publication date: 1961-12-05
Anticipated expiration: 1978-12-05

Description

Dec. 5, 1961 w. A. KLEIN EIAL 3,011,688

DISPENSING CONTAINER Filed Jan. 20, 1958 s Sheets$heet 1 f I l [I I t 1 5a 22 1 1h 22 l INVENTORS. Wa/f er A. k/el'n Alba/'2 J M n John HoQsc/au HTTORNEYS Dec. 5, 1961 w. A. KLEIN ErAL 3,011,688

DISPENSING CONTAINER Filed Jan. 20, 1958 s Sheets-Sheet 2 INVENTORS. Wo/Ier A. Klein fl/ber/ J Mason I John /-/o[3.5c/zu HTTORNEKS Dec. 5, 1961 w. A. KLEIN ET AL DISPENSING CONTAINER 3 Sheets-Sheet 3 Filed Jan. 20, 1958 INVENTORS. W0//er A. Klein fi/ber/ J Mason John Holgschu HTTORNEKS United States Patent 3,011,688 DISPENSING CONTAINER Walter A. Klein, Albert J. Mason, and John Holzschu,

Midland, Mich, assignors to The Dow Chemical Company, Midland, Mich, a corporation of Delaware Filed Jan. 20, 1958, Ser. No. 710,154 9 Claims. (Cl. 22547) This invention relates to an improved and exceptionally utile box or container for packaging supply rolls of plastic film and the like or similar sheet wrapping materials (including such metallic and paper based wrapping stock as metal foil and waxed paper) which box is adapted to efiiciently and effectively dispense the sheet wrapping material therefrom. In particular, the invention relates to a box for containing and dispensing very large, giant-sized capacity rolls of sheet wrapping material, especially plastic wrapping film, for domestic and commercial consumption. The present application is a continuation-in-part of the copending applications for United States Letters Patent having Serial Nos. 652,003 and 652,054, both filed on April 10, 1957, now US. 2,850,157 and US. 2,836,292, respectively.

it has become quite popular and of increasing attractiveness to manufacturers, merchandisers and consumers alike to package plastic wrapping film and other sheet wrapping materials in very large, individually boxed supply packages that contain sufhcient amounts of the wrapping material for the satisfaction of considerable demands. For example, in contrast to the usual 25 to 50 or so feet rolls that were formerly provided as a matter of course for most domestic and many commercial users, it has become a more widespread and desirable practice to furnish the sheet wrapping material in supply rolls having lengths of at least 250 feet. Frequently, as a matter of fact, 1,000 feet or longer supply packages are found to be much in demand in the form of individually boxed units. Supply packages of this magnitude, due to their considerable ponderosity, are ordinarily of a relatively immobile character insofar as their handleability is concerned.

The satisfactory dispensing from supply packages of many sheet wrapping materials, particularly plastic wrapping film, has been the source of many difficulties and vexatious problems. Most plastic films, for example, especially the varieties that are best suited for wrapping purposes, have a great tendency to cling to the supply package (such as the peripheral surface of the roll) from which they are being dispensed. In addition, they oftentimes have an unhappy propensity to recoil, feed back or otherwise revert to the supply package, even after their free or loose end has been separated therefrom for withdrawal of a desired length from the supply package. It may sometimes be no easy task to maintain the loose or free end of the sheet wrapping material, particularly when it is a plastic wrapping film, inaccessible, partially exposed disposition in or on the supply package to facilitate its being readily available for easy withdrawal therefrom. Such problems are not minimized or alleviated by virtue of the provision of the sheet wrapping material in a very large capacity wound supply roll.

Besides this, when large supply packages are involved, they are generally found to be too bulky and heavy for convenient manipulation and handling when it is desired to withdraw lengths of the sheet wrapping therefrom. As has been indicated, the very size of the box oftentimes prohibits its being picked up in one hand to permit grasping of the loose end of film or other wrapping for withdrawal with the other in the familiar manner that is conveniently employed with smaller sized containers. The problems which arise in connection with this for the 3,fi1l,88 Patented Dec. 5, 1961 giant sized, individually boxed, Wound supply rolls are very real and serious indeed. They are oftentimes amplified by the fact that the user may be inclined to or desirous of grasping or withdrawing the wrapping material from the large supply package without actually lifting or otherwise contacting the box, or that such manner of utilization may actually be a practical necessity. This may be the case when it is wished to employ both hands for uniform withdrawal of the sheet wrapping material and for its better control after beingwithdrawn and severed from the supply package, as well as for more efficacious accomplishment of the immediate wrapping task being performed.

As a consequence, besides the difficulty in maintaining the loose or unwinding end of the sheet wrapping material in easily accessibly disposition, it may be quite difficult and troublesome to properly and satisfactorily sever the sheet material from a very large capacity and individually boxed supply roll after it has been withdrawn therefrom in a suitable length. Since the large box does not lend itself to ready lifting or convenient manipulation, it is not always easy to pull or urge the withdrawn length of sheet wrapping material at an optimum angle for its elficient slitting or severance against the cutting edge that is conventionally provided on the container, usually along one of the outer edges thereof. Furthermore, especially when the user is inclined or re quired to employ both hands for and during withdrawal, the box may tend to slip and be pulled along the surface on which it is rested during the efforts to withdraw the desired length of wrapping and to sever the withdrawn length from the supply. In addition, when the usual square cross-sectional type of box is being employed in such a manner that the withdrawn sheet is being manipulated for severance over the cutting edge without manually or otherwise propping the container, there is an almost unavoidable tendency for the box to be tipped or pulled over on its side during the operation.

To illustrate these points, most sheet wrapping materials, especially plastic wrapping film, are generally best cut when they are urged or pulled upon while being substantially bent over the usual cutting edge employed for their severance. Oftentimes, the more nearly the sheet is made to bent at a right angle or actually at an acute angle across the cutting edge during its severance, the better and more efficient is the resulting cutting action. Now then, when a sheet is Withdrawn from the upper side of a supply package as may be contained in the usual square cross-sectional box that has a cutting means along one of its edges and which is resting flatly on a supporting surface, it is practically impossible (without releasing the original grip and regrasping the sheet close to the outlet) to bend the withdrawn sheet at an emcient cutting angle across the cutting edge, especially when a substantial length of the sheet is withdrawn for severance from the supply package. This is so, regardlws of the particular direction in which the cutting edge is disposed or faced, since the surface usually prevents bending the sheet across the cutting edge at an optimum angle for best results which, generally, is an acute angle or one that is not much greater than a right angle. And, even if the supply package is placed near the edge of a sup porting surface in order to facilitate bending the with drawn sheet at better cutting angles across the cutting edge, there is great danger and likelihood of the box being pulled over the edge and off the surface during withdrawal or severance of the sheet. Such an occurrence cannot, of course, be tolerated. Furthermore, as indicated, the pull on the top of the box tends to upset it in such operation.

It would be advantageous and it is among the major objects of the present invention to provide an improved and practically efiective dispensing box that would be well adapted to maintain the loose' end of a wound supply package of sheet wrapping material contained therein 11] easily accessible disposition while affording optimum cutting performance and severing action on withdrawn lengths of sheet material from the supply. It would be particularly advantageous if such box had maximum stability and resistance to being upset during its use and manipulation when dispensing Without manual or other physical propping or steadying support being provided therefor. While by no means restricted in its utility thereto, the dispensing boxes that may be provided in accordance with the invention are particularly adapted for utilization with wound rolls of plastic wrapping films, especially when they are contained in very large capacity or giant sized supply packages of the type which, because of their inherent ponderosity, are relatively immobile and not adapted for manual lifting and handling during use.

According to the present invention, the above-mentioned and related advantageous results may be secured and the described difii ulties and problems readily overcome in an improved dispenser box for wound supply rolls (preferably large capacity packages, especially of plastic wrapping film, that are wrapped on supporting cores) which comprises an elongate container having somewhat of a truncated pyramidal shape with a trapezoidal cross-section formed by fiat top and bottom walls, inwardly and upwardly sloped front and rear walls and a pair of enclosing end walls between which said side walls extend longitudinally and in opposite, upwardly sloping dispositionto accommodate the width of a hollow, wound supply roll of sheet wrapping material contained therein; roll supporting means adjacent to said end walls, preferably of hub-like design or of the insertable mandrel type, that are adapted to be inserted within the ends of a wound supply roll in said container and to conform at least approximately to the inner hollow space in the open ends of said roll for supporting and maintaining said roll therein; means in said top wall for forming an elongate, linear, slit-like outlet for said sheet Wrapping material when it is contained in said container; said outlet extending longitudinally in the direction of the width of said supply rollaccommodating length of said container; a contiguous pair of bendable, lip-like flaps, formed by means tending to urge one against the other, extending upwardly from. said top wall along said outlet, one of said flaps being positioned on each side of and adjacent to said outlet, said flaps being adapted to fn'ctionally engage and grasp said sheet wrapping material when it is emerging through said outlet; said flaps being advantageously formed, preferably with a spaced pair of matching cutouts in each flap, to permit engagement of said sheet wrapping material when it is contained and grasped therebetween; and a cutting means mounted on said box in spaced, parallel relationship with said outlet, positioned over said outlet at a greater distance therefrom than the height of said flaps and being situated in a plane that extends between said outlet and said cutting means which is at an acute angle to the top Wall in which said outlet is formed. Advantageously, at least one and preferably both of the end walls of the container are formed and provided as openable flaps. The insertable roll supporting means for insertion within the end of the supply roll to maintain it in unwindable, dispensing position when the box is closed are beneficially mounted on an inner, foldable partition that is disposable in upright position adjacent to the end walls. It is also of advantage for the cutting means to be mounted on a longitudinally extending, accordion-folded flap or crease strip that is adapted to be triangularly secured in easel-like style and positioned either on or along the outlet-containing top wall of the box in order to assemble it for dispensing and cutting utilization, which flap 'fOr mounting the cutting means is further adapted to be folded out of the way over the side of the box then not in use.

Further features, advantages and objects of the present invention are apparent in the following description and specification, taken in connection with the accompanying drawing in which one suitable embodiment of the invention is illustrated, wherein.

FIGURE 1 is a plan view of a box according to the invention;

FIGURE 2 is a front elevation;

FIGURE 3 is a sectional end view taken along the line 3-3 in FIGURE 2;

FIGURE 4 is an end view of the box illustrating a beneficial variation in technique or means for assembling the strip which supports the cutting means;

FIGURE 5 is an end View of the box with the cutting means support disassembled and folded over the side of the container;

FIGURE 6 is a front elevation in section taken along the line 66 in FIGURE 1;

FIGURE 7, a fragmentary perspective view, shows one end of the box open, and

FIGURES 8 and 9, end and plan views respectively, illustrate the sheet cutting action of the container during a dispensing operation.

There is shown in the drawing a dispensing box, indicated generally by the reference numeral 57, that is in accordance with the present invention. It is preferable for the box 57 to be in the form of a somewhat pyramidally formed roll-accommodating container having inwardly sloping front and

rear walls

36, 37, respectively. The box may be fabricated from cardboard, paperboard, fiberboard or like material of construction. If greater permanence is desired, however, all or portions of the box may also be fabricated of wood, metal or plastic materials. As indicated, the cross-section across the width of the box is preferably in the form of a regular trapezoid'so as to provide the container with greater slip and tip-resistance due to a broader base. The upper or dispensing top Wall 38 between the opposite upright end Walls, indicated generally by the

reference numerals

9 and 10, respectively, is formed to have a preferably (though not necessarily) central, elongate, linear, slit-like cleft or outlet 11 for the sheet material 12 that is withdrawn from the supply roll 13 wound on the supporting core 14 which is maintained within the container. As shown, the outlet 11 extends for the entire length of the box 57. The box itself is best made to conform closely to the contained supply package of wrapping material, with minimum clearance between the sloped side walls and the supply package.

Advantageously, the width of the relatively more narrow top wall 38 with respect to the supporting and surface-contacting bottom of the container is between about one-half and three-quarters of the bottom. Of course, if desired, other relative width proportions between the top and bottom of the box may be restorted to. Preferably, the width of the upper or top wall 33 of the box is from about 50 to 60 percent of the width of the bottom of the box as, say, in a ratio of about 4 to 7 inches or so. This provides a box having excellent stability against being tipped over in non-propped dispensing operations and good anti-sliding qualities in use. It also facilitates packing and shipping of a plurality of such containers without intolerable problems of Wasted space and permits maximum roll capacity for a given size container.

The wound supply roll of sheet wrapping material is supported and maintained in unwindable disposition in the container by and upon a pair of mandrels or end inserts 15, i6 one of which is adapted to fit in each end of the supporting core 1-4 upon which the sheet material 12 is packaged. As is particularly shown in FIGURE 5, the

mandrels

15, 16 are secured to and more or less journaled in accommodating apertured support partitions that are bendably integral with a core cradle 45 adapted to be disposed within the container 57. The mandrelsupporting partitions of the core cradle 45 are adapted to e held upright parallel with. the end. walls 9 and 1% of the container in such a manner that the closing of the end walls maintains the mandrels inserted in the ends of the core 14. The core cradle 45, as mentioned and illustrated, conforms closely to the interior of the container 57. The mandrel-supporting partition arrangement of the core cradle 45 is also illustrated in detail in FIGURE 7, wherein the container 57 is shown with one of its end walls open.

if desired, although not illustrated in the drawing, the core cradle 45 may be eliminated and the mandrels or roll supporting inserts positioned integral with and upon one of the openable flaps in a tuck flap end closing arrangement that forms and provides at least one, and preferably both, of the end walls in the container. Thus, the mandrel 16 may be an integral part of one of the open

able flaps

17 or 13 which (as depicted in FIGURE 7), together with the cooperating tuck flap 19 at the end of the container, can be closed to form the end wall 10 while simultaneously inserting the mandrel into the open end of the hollow core 14 on which the roll of sheet wrapping material 13 is wound. Such an arrangement, which can be adapted to the present container, is more particularly illustrated in the referred-to copending application Serial No. 652,054.

Advantageously, the

mandrels

15, 16 may be fabricated by stamping out fiat metal sheets. They may also be constructed of solid metal or wood or, with great benefit, hollow or solid plastic sections. Other desired materials and in any preferred form may also be used for the intended purpose. Likewise, the mandrels need not be hublikein shape, but can be any suitable variety of insertable construction that is adapted to maintain and support the roll, such as a plurality of circularly disposed rods or pyramidal and other polygonal hollow or solid shapes that may have continuous or discontinuous coreengaging surfaces. The mandrels may be loosely inserted in the apertures of the supporting partition members of the core cradle 45 or they may be aiiixed thereto (or to the end wall or flap thereof of the container when such an arrangement is employed) by any desired means including'adhesives, rivets, staples and the like or by forming them with integral perforating tines, prongs or points useful for their mounting. In such cases it may not be necessary to use an apertured partition member for their support. it is generally most expedient to loosely insert the mandrels as shown, in apertured partition members of a core cradle or the like element.

A contiguous exterior pair of bendable lip-like flaps 2t} and 21 (that advantageously may be creased or foldable at their base juncture with the top wall 38 of the box 57in order to permit their bending or flip-flopping sort of functionality) are positioned one on each side of the outlet 11. The

flaps

20, 21 are best formed with suitable cut-out portions or indentures 22 to facilitate ready grasping of the portion of thesheet material 12 that is extending between and located within the flaps, when it is desired to withdraw the sheet material from the box. The contiguous, lip-like pair of

flaps

20, 21 are formed by any suitable means so as to tend to urge one against the other over the outlet 11. When made of cardboard or the like, the

flaps

20, 21 may, as has been indicated, be easily made to be satisfactorily folda'ble by creasing or bending them upwardly from the top wall 38 of the box 57 along a line on the top wall parallel with the outlet 11. Of course, various resilient means may also be incorporated in or on the box to urge the

foldable flaps

20, 21 one against the other. It is generally best for the height of the

flaps

20, 21 to be such that when pressed thereagainst, they reach about or almost to the cutting means 26 that is positioned above the level of the outlet 11 in a plane therewith that is at an acute angle to the upper side 38 of the box 57, conveniently at some angle up to 90 but greater than about and, preferably, greater than As is apparent, the

contiguous flaps

20, 21 which usually extend at a right angle to the top Wall 38 of the box 57, are adapted to frictionally engage and grasp the sheet wrapping material 12 that is contained therebetween. This tends to prevent the recoil or feed back of the sheet 12 to the supply roll 13 after a Withdrawn portion of the sheet has been severed from the supply package. In addition, the flaps avert the possibility of the sheet wrapping material from laying flat and in relatively inaccessible disposition on any of the surfaces of the box. This may be a particular problem with some types of sheet Wrapping stock, particularly certain types of plastic wrapping films, which often tend to cling tenaciously to many surfaces over which they are disposed. The trapezoidal shape of the container also tends to prohibit riding up or lifting of the supply package within the container during dispensing in the event that it is not securely mounted and held therein. If desired, and as is particularly indicated in FIGURE 7, additional means may advantageously be included within box 57 to assist in the frictional snubbing and braking of the supply roll that is contained in the package. Thus, an interior pair of divergent, resiliently hinged

flap elements

23, 24 may depend within the box, one from each side of the outlet 11, to extend over and flatly contact the supply roll 13 or" the sheet material 12. As shown, the flap elements may be formed integral with the top wall 38 of the container while being positioned parallel with and near the edges of the outlet 11. The

interior flap elements

23, 24 may be similar to those which have been disclosed by Walter A. Klein in United States Letters Patent No. 2,799,393. In this connection, many other of the interior and constructional features of boxes in accordance with the present invention may also be similar to those in the container that has been disclosed in the referred-to patent.

The cutting strip 26 may be of any desired material and it may have a serrate or straight cutting edge, as may be preferred.

An advantageous means for positioning the cutting means 26 at an elevation on the assembled box with respect to the outlet 11 consists of a foldable flap panel 25 secured centrally on the top wall 38 of the box 57 near the outlet 11 which is adapted to be supported in a triangular or easel-like manner on the top wall 38 by means of one or more tabs 27 adapted to be inserted in accommodating slots in either the top or side wall of the box in order to maintain the cutting means 26 elevated at a level above the outlet 11 and in a plane therewith that lies in an acute angle to the top wall 38 when the flap panel 25 is assembled and the box is ready for dispensing the sheet material. Generally, at least two tabs and matching slots are preferred. When greater elevation and angularity is desired, the tabs 27 may be inserted in the slots 2ST provided along the edge of and in the top wall 38 of the container 57. If less elevation and angularity is desired, which may frequently secure a very beneficial cutting action, the tabs 28 may be held in the slots 288 provided at a suitable point in the inwardly sloped rear wall 37 of the container. As shown, the cutting means 26 is positioned along the uppermost folded edge of the panel 25 that is formed by the accordion-fold crease provided therein when the flap is assembled. The flap panel 25 is best arranged to lay flatly on the top wall 38 of the box 57 and fall over its inclined rear wall 37 when it is not in use, as is shown in FIG- URE 5 of the drawing. FIGURES 3 and 4 respectively illustrate the use of the top wall and side wall slots 2ST, 28$ for varying the elevation of the cutter.

As is apparent, the container arrangement of boxes in accordance with the present invention prevents recoil (or inadvertent withdrawal without positive tractile effort) of the withdrawn sheet material to insure that an extending portion of the sheet will remain in an accessible exposed condition between the foldable sheet engaging.

significance, the sheet material may be withdrawn and severed from the supply package at a very efiicient rig t or near right acute cutting angle. As has been indicated, the sheet material may be withdrawn by the user to a desired length and bent sharply over the elevated cutting edge in order to sever it from the supply roll (as demonstrated in FIGURE 9) without changing the original sheet grasping position of the hands or manipulating the box for this purpose. During this operation, as is also illustrated in FIGURE 8 of the drawing, the lip-like flap 20 is bent against the cutter 26 on the foldable flap 25. As a matter of fact (although not so illustrated) both of the

flaps

20 and 21 may bend with the sheet and move towards the cutter durirn the cutting operation. In this connection, boxes in accordance with the present invention obtain the optimum cutting or tearing action that is possible for the sheet material withdrawn from the package over the cutting means associated with the container due to the positive snubbing and nipping effect exerted by the foldable flaps on the length of sheet material emerging therethrough, especially when either or both of them are bent over with the sheet so as to positively it while it is being cut. Furthermore, due to their broad based and advantageously configured construction, the boxes of the present invention are extremely dilficult to pull or tip over during dispensing and cutting opera.- tions wherein the sheet wrapping material is withdrawn and severed without manual positioning support being provided for the containers.

Dispensing boxes in accordance with the present in-,

vention may be employed with particular advantage for plastic wrapping films such as those which are comprised of copolymers of vinylidene chloride and vinyl chloride which may frequently be generically characterized as being sarans and which enjoy great favor as a Wrapping material for domestic and other uses, especially when they are being provided in giant size, very large capacity supply rolls.

What is claimed is:

1. A dispensing box for packaging a hollow wound supply roll of sheet wrapping material which comprises fiat bottom and top walls, said top wall being more narrow than said bottom, inwardly and upwardly sloped front and rear walls connecting said bottom and top walls, and a pair of enclosing end walls between which said bottom, top and side walls extend longitudinally to accommodate the width of said supply of sheet wrapping material that is adapted to be contained therein, said box having a trapezoidal cross-section; roll supporting means positioned in said box adjacent to said end walls, said roll supporting means conforming at least approximately to the interior of said hollow wound supply roll and adapted to be inserted within the ends of the roll when it is contained in said container in order to maintain and position the supply roll therein; means in said top wall forming an elongate, linear, slit-like outlet for said sheet wrapping material when it is contained in said container, said outlet extending longitudinally in said top wall in the direction of the width of said sheet wrapping material when it is contained in said container and parallel to the width-accommodating length of said container; a contiguous pair of bendable, lip-like flaps, comprising means tending to urge one against the other, extending upwardly from said top wall along said outlet, one of said flaps being positioned on each side of and adjacent to said outlet, said flaps being adapted to frictionally engage and grasp said sheet wrapping material when it is emerging through said outlet; and a cutting means mounted by means on said box in spaced, parallel relationship with said outlet positioned above said outlet at a greater distance therefrom than the height of said flaps and being situated in a plane that extends between said outlet and said cutting means which is at an agle of from about 15 to to the top wall in which said outlet is formed.

2. The box of claim 1, wherein the width of said top wall is between about one-half and three-quarters of the width of said bottom.

3. The box of claim 1, wherein the width of said top wall is from about 50 to 60 percent of the width of said bottom.

4. The box of claim 1, wherein the means for mounting said cutting means thereon is a foldable, accordioncreased flap panel extending longitudinally from along the outlet from said outlet containing side wall, said cutting means being provided along the foldable edge which extends furtheest from said Wall when said panel is assembled, said foldable panel being adapted to be elevated from and secured in easel-like fashion upon said box to position said cutting means in said angled plane and being further adapted to be folded over and rested flat against the side Walls of said box when not in use.

5. The box of claim 4, wherein said outlet is centrally positioned in the uppermost side wall of said box and wherein the height of said contiguous flaps extending upwardly therefrom is almost equal to the distance between the outlet and said cutting means, at least one of said flaps be ng adapted to move towards said cutting means with said sheet wrapping material when it is being dispensed and severed from said supply package.

6. The box of claim 4 and including, in combination therewith and in addition thereto, at least one slot in said top wall of said box and at least one matching tab on said foldable flap panel that is insertable in said slot, wherein said foldable flap panel may be elevated from and secured upon said box by inserting said tab means in said accommodating slot means.

7. The box of claim 4 and including, in combination therewith and in addition thereto, at least one slot in a side wall of said box adjacent to said foldable flap panel and at least one matching tab in said foldable fiap panel that is insertable in said slot, wherein said foldable flap panel may be elevated from and secured upon said box by inserting said tab means in said accommodating slot means.

8. The box of claim 1 and including, in addition thereto, a spaced pair of matching cutouts in each of said contiguous flaps to permit engagement of said sheet material when it is contained and grasped therebetween.

9. The box of claim 1 in combination with a wound supply roll of plastic wrapping film packaged therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,408 Meyer Mar. 31, 1925 1,630,495 Marcalus May 31, 1927 1,816,384 Marcalus July 28, 1931 1,897,143 Powell Feb. 14, 1933 1,969,625 Scarpa Aug. 7, 1934 2,096,837 Baker Oct. 26, 1937 2,226,477 Moore Dec. 24, 1940 2,334,997 Doll Nov. 23, 1943 2,391,112 Wolteger et al. Dec. 18, 1945 2,433,445 Elsman Dec. 30, 1947 2,500,012 Smoak Mar. 7, 1950 2,890,822 Lee et al, June 16, 1959