US2676360A

US2676360A - Method for making plastic binders

Info

Publication number: US2676360A
Application number: US134158A
Authority: US
Inventors: Emmer Charles Edward
Original assignee: General Binding Corp
Current assignee: General Binding Corp
Priority date: 1949-12-21
Filing date: 1949-12-21
Publication date: 1954-04-27
Anticipated expiration: 1971-04-27

Description

April 27, 1954 c. E.- EMMER 2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Dec. 2l, 1949 4 Sheets-Sheet l fm1/*E27 far' CfzazjieEcZw/azd Emmer April 27, 1954 c. E. EMMER 2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Dec. 2l, 1.949.

4 Sheets-Sheet 2 April 27, 1954 c. E. EMMER 2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Deo. 2l, 1949 4 Sheets-Sheet 5 Mfww April 27, 1954 c. E. EMMER METHOD FOR MAKING PLASTIC BINDERs Filed Deo. 2l, 1949 4 Sheets-Sheet 4 .materials in a Patented Apr. 2'?,y 1954 UNITED STATES PATENT OFFICE 2,676,360 METHOD Fon MAKING PLASTIC BINDERS Charles Edward Emmer,

to General Binding a corporation of Illinois v Application December 21, 1949, Serial No. 134,158

1 claim. (ci. isz-56),

This invention relates to a method for making plastic ,binders and has as its principal object to provide such a method and apparatus arranged to produce ,binding elements, from thermoplastic materials, free from defects and spoilage in a more eilicient and expeditious manner than formerly, with little attention from the operator. of my invention is to provide a new andY improved process for making plastic from blanks of thermo-plastic cooling.

a new and improved process for making plastic binding elements or the like from thermo-plastic more Vfacile and positive manner than formerly by pre-heating the blanks and then curling the pre-heated ,blanks to a substantially circular form, and at the same time rolling 'the blanks and softening them during the rolling operation by heat, and then setting the blanks by cooling.

plastic material by pre-heating a plastic blank and then gripping the leading edge thereof and feeding 1t in a rotational direction and at the forming mandrel;

Figure 2 is a fragmentary view of a completed binding element; f

Figure 3 is a other parts shown in section;`

Figure 4 lis a View in side elevation of the apparatus shown in Figure 3 showing the operative parts thereof in a forming position;

Figure 5 is a view in side elevation of the apparatus shown in Figure 3, but looking at the from Figure 4 and showing the parts in position forming mandrel; and l Figure 6 is an `enlarged fragmentary detailed transverse sectional view taken substantially along-the line VI-`VI of Figure' 3@ 1 On the drawings: n'

Chicago, Ill., assigner Corporation, Chicago, Ill.,

Figure 1 shows a fragment of a comb-like blank lrwhich may be made from a sheet of thermoplastic material such as the vinyl chlorides or vinylacetates, known to the trade as Vnylite, or cellulose acetates, butyrates and ethylcellulose. It may also be made of various other vinylresins and from nylon compoundings, as well as any` other suitable materials desired. The blank ||l is herein shown as having a backbone portion having a plurality of spaced relatively long nteeth |2|2 extending therefrom in one direction, and short teeth 3| 3 extending therefromlin an opposite direction -and herein shown as being `arranged alternately of the teeth |2| 2 so as'to extendvin the spaces between the teeth |2-|2, whenpthe blank has been curled to the form of a complete binding element M, as shown in Fige2. .Y Y. Y

, A forming mandrel I5 isshown in Figs. 3 and 5 as being, rotatably journaled ona vertically movable frame structure |17, consisting of two parallel ,spaced arms IB-I, connected together lby cross members I9, |9 and transversely pivoted adjacent their rear ends on the overhanging end of a transverse shaft 20, journaled on the upper ends of parallel spaced links 2|, 2|.vv lThe links 2|, 2| are pivoted attheirlower ends to the insides of side walls 22f22 of the frame'23v of the machine on a transverse shaft V26.l The links 2|2| are con- 21 is pivotally mounted at itsrear end on theshaft 20, on the outside of the side wal1'22, and extends forwardly therefrom and is supported adjacent kits forward end on a l as projecting (see Figure 5). The arm 2l has an lupwardly Vopening slot 30 adapted to receive the opposite end of the mandrel I5 from spaced transversely 35-35 .(see Figure 6)..v Said rollers are suitably journaled adjacent their,v opposite ends .in the y side walls "Z2-22. fori free rotation .with respect ther-eto and are backed up at their outer sides so as to avoid the tendency of said rolls to spread when supporting the mandrel I5, by parallel spaced backing rolls 36-36 extending transversely of the frame 23 and suitably journaled in opposite side walls thereof. The rolls --35 are held from downward deiiection by means of a transversely extending roll 39, suitably journaled in opposite side walls of the frame y23, and having its axis extending between the axes of the

rolls

35, 35 and forming a rotatable support therefor.

A heating roll is rotatably mounted` at its opposite ends so its full weight may rest on the mandrel I5 during the forming or curling operation in upwardly opening slots ll- 4i formed in the free endsof parallel spaced arms 153-43. The arms 43-43 are pivotally mounted adjacent their opposite -ends on upright extensions t4-44 of the side walls 22-22 on a transverse shaft 45. rfhe heating roll 40 is `adapted to be supported on the forming mandrel I5 during the forming and curling operation and to have rolling engagement with the top sides of the plastic blank Iii and heat and roll the blank into engagement with the outer periphery of the forming mandrel I5. rfhe heating roll 45 thus serves both as a softening or heating roll and as a forming roll, to form the blank to the form of the mandrel I5, when soft. Said heating roll may be of any well known form, and is preferably made from metal, such as iron, steel or brass and has a plurality of heating elements lll- 41 extendingr therethrough (see Figure 6). The heating elements 41-41 are diagrammatically shown in Figure 6 as being electric heating elements and are not shown or described in detail herein, since they may be of `several well known forms.

Current is herein shown as being conducted to the heating elements 41-41 by means of two spaced collector rings 49-49 mounted on a shaft 5t extending outwardly from said heating roll and concentric with the center thereof. The collector rings 49-49 maybe engaged by brushes 5I-5I, arranged to :supply current thereto, and may be suitably insu-lated from each other and be suitably connected to the heating elements lil-Ali, to conduct electric current thereto.

lThe temperature of the heating -roll 40 may be controlled by a temperature-sensitive device 53, slidably engaging the top surface of said heating roll, and pivotally mounted on and depending frorn a longitudinally extending vertically movable arm 54. being pivoted at its rear end to an upright support 55, extending upwardly from a transverse plate 55, mounted on the upright extensions 44--44 of the side Walls 224-22. rIhe temperature-sensitive device may be suitably connected to electric control means (not shown) having connection with brushes 5I-5I and collector rings IIS-49, to Vstop the flow of current to the heating elements llL-41, when the temperature of the roll 40 becomes too high, and to supply current to said heating elementsand maintain the temperature of said roll at a predetermined constant temperature, which may be capable of being set for the various forms and thicknesses of plastic material used to make the binding elements. rEhe temperature sensitive device 53 and the control connections therefrom to the heating elements 41;, maybe of any well knownform and are no part of my present invention so are not herein shown or described in detail.

The arm 54 is shown as of the side walls ably drive the form'ng mandrel A power operated means is provided to first pivot the arms 43-43 upwardly and raise the heating roll 40 out of engagement with the mandrel i5 and then raise the mandrel I5 out of engagement with the support rolls 35--35 to permit the formed binding element to be stripped from the free end thereof.

The means for elevating the heating roll o and the mandrel i5 in a predetermined sequence, is herein shown as including two spaced cams 5e- 5B mounted on transverse shaft 50, inwardly 22-22 of the frame 2|, and two spaced cams BI-GI mounted on said transverse shaft on the outer side of the side wall 22, which in Figure 3 is the left hand side wall. rhe shaft ii is suitably journaled in the side walls 22-22, and projects beyond opposite sides of said side walls, and has a counterweight 62, on its right hand outer end. IThe counterweight 52 is arranged toaid lifting of the heating roll 40 and mandrel I5, and to hold said roll and mandrel in elevated positions. The cams 59--59 on the transverse shaft 5i) are engageable with rollers (i3- 53' mounted on and extending in- 43-43, to elevate said arms upon rotation of said cams, and to permit them to move downwardly and allow A de to come into engagement with the forming mandrel I5. The cams EI--SI on the transverse shaft 60 are out of phase with respect to the cams 5$-E9 and are engageable with cam followers or rollers fe- 54 journaled on the sides of the arms Iii-48 of the frame structure I1, adjacent the side wall 22 of the frame 23 on stub shafts e-65.

It may be seen from Figures 4 and 5, that as the shaft 60 is rotating in a direction which in Figure 4 is shown as being a clockwise direction, the cams 59--59 engaging the followers 53-53 will move into position to elevate the arms 59-59 and the heating roller 40 at a relatively rapid initial rate,v and then hold said arms and heating roller in an elevated position until the formed blank has been cooled and stripped from its mandrel, and then allow said heating roll to .drop into engagement 'with said mandrel for the next forming operation. This will quickly remove the heating roller 4l) from the formed blank on the mandrel I5 as soon as the blank has been formed thereon, and will prevent overv-heating or injury to the blank. After the heating roller 4Q has been fully elevated, the cams iii- 5| will then raise the frame Ystructure I1 and the mandrel I5 out of engagement with the support rolls 35--35 and the upwardly opening slot 30, and will hold said mandrel in position for cooling the formed blank and the stripping of the formed blank therefrom.

The formed blank may be 'cooled when the heating roll 4I! is lifted therefrom., by contact with the air and with the support rolls 35--35. In order to facilitate the cooling operation, however, I herein show a pipe 65 spaced from and extending along the mandrel I5 and having a plurality of Aor-'iiices l-L61 opening therefrom and directed to discharge blasts of cold air on the rotating blank (see Figure 4) A motor 69 is herein shown as being mounted on a support bracket 'in projecting from the left :hand side wall 22,

to rotatably drive the cams 59--55 and GI-GI and also to rotatably drive the lcams 59^-59 an'd 6I6I and also to rotat- I5. The motor B9 well known form, having `fa speed reducer may be an electric motorfof any preferably of the type built therein so as to have a relative slow output speed. The motor69 has a drive shaft 1| the axis of which is coaxial with the shaft 22. The shaft 1I is connected to drive the transverse shaft 2U, journaled in the side walls 22-22 and in the frame structure I1, by means of a chain and sprocket drive 12. A sprocket 12 is lkeyed to the shaft 20 drives the transverse shaft 60 through a chain and sprocket drive 14.. Another sprocket 15 is shown as being keyed on the outer end of shaft and serves to drive a shaft 16 and the mandrel I5 through a chain and sprocket drive 11. The shaft 16 projects from the mandrel I5 and is Journaled in the frame structure I1, and also forms a support for said mandrel, supporting said mandrel in overhanding relation with respect to said frame structure. Tension is maintained on the chain and sprocket drive 14 in all positions of y suchthat the heating roll .40 will remain in-enstantaneously move away from said mandrel out of engagement with the formed blank. Where, however, larger binding elements may be formed from blanks of.V greater cross-section, the speed reduction may be such, or may be capable of being changed to take care of the thicker blank so that the roller will remain in engagement with the blank during two vor more revolutions of the Yblank,.plus the distances of any overlap ofthe blank. Various forms of change speed gearing may` be used toveifect this, whichare not herein shown or described since they are no part of my present invention.

A stripping sleeve 19 is mounted on the mandrel l5 forvslidable movement therealong, to strip the cooled and formed binding element from the open end thereof when the mandrel I5 has been raised above the support rolls 35-v35 into the position shown in Figure 5. The stripping sleeve 19, as herein shown, has an arm 80 extending therefrom having a boss `8I at its outer end, to which is secured a piston rod 83. The piston rod 83 extends from a piston 84 movable within a cylinder 85. The cylinder 85 is herein shown as being of a double acting type of Iair cylinder sufficiently long to move the sleeve 19 along the entire length of the mandrel I5. The cylinder 85 is supported on bracket members 86-86 projecting from the free ends of the arms |8-I8 of the frame structure I1 (Figure 3).

The means for feeding each plastic blank to the mandrel I5 includes the inclined feeding with a blank receiving slot B1 extending along the mandrel I5 from one end thereof to the other, and-opening to opposite ends thereof (see Figure The feeding plate 25 is adjustably supported on the side walls 22-22 of the frame 23 on two pairs of laterally spaced links 88-1-88 and 89-39, pivotally supported at their lower ends on transverse shafts Si! and 9| and extending across opposite side walls 22-22. The upper ends of the links .88--88 and 89-89 are pivotally connected to lugs 93-93 and 94-94 respectively, depending -from the feeding plate @if A threaded regal mcveeblein arcuate slots respectively, mounted inv 6. 99-99 formed in opposite side walls' 22-22 of the frame 23 extends through the two links f8888 and is herein shown as having wing nuts I 00-I00 threadedon opposite ends thereof, to afford a means for holding. the feeding plate 25 in the proper relationship with respect to the blank receiving slot 81 for the various diameters of mandrels which may be used to form the various binding elements desired.

A feed box |03 is mounted on and extends upwardly from the receiving end of the feeding plate 25, and is adapted to receive a stack of plastic blanks lIII-II), placed therein with the teeth I2 facing the mandrel I5. The feed box |03, as herein shownhas an adjustably moveablerear wall forming a back up plate |04. Said back up bolts I 05-| 05 having wing nuts threaded on the outer ends thereof, and slidably guided in vertically spaced longitudinal slots IUS-|06, formed in side walls I l1-|01 of said feed box. The back up plate |34 is adapted to abut the rear faces of the blanks I B I Il to hold them in line within the feed box |03 and is adjustable to adapt said feed box to the various sizes of blanks that may be used.

The meansfor ejecting the blanks Il! from the bottom of the feed box |03, one at a time is herein shown as being a pusher plate |08 slidably guided in the bottom of said feed box and having a hand grip |09 at its rear end. The pusher plate IEB is thus withdrawn behind the back up plate |64 to allow a blank I0 to drop the bottom of the feed plate |95, and then is moved forwardly to slidably move .the blank I0 downwardly along said feed plate and move the teeth I2 of said blank into engagement with the blankreceiving slot 81 formed in the mandrel I5.

kWhile I have herein shown a manually operable pusher plate to strip the bottom blank Il) from it may readily be understood top blank of the pile. may be particularly advantageous where light weight blanks are drel I 5, to be made into binding elements.

The feeding plate a source of electric power by electrical conducts III- IIL The heating elements IIB-III) may be of any well known form and are provided to heat the feed plate 25 sufliciently to preheat the individual blanks as they are fed therealong into engagement with the blank receiving condition the blank to readily follow saidmandrel before coming into engagement with the heating roll 40. The preheated temperature of forms no part of my present invention.

Aprelieatingv shoe I I2 forV the'top side of tha being fed to the forming inanslot 81 of the mandrel I5, toy

acre-seo blank I? is herein shown pivoted to laterally spaced ears I ing forwardly from the feed box L03, adjacent its lower end. The prel'ieat'ngv shoe I I2 extends forwardly of the feed. box |03 to a position adjacent the discharge end of the feed plate 25, and is adapted to rest on the top surfaces of the blanks I0 as they are fed along said feed plate into engagement with the blank receiving slot 91. The preheating shoe I,I.2 is diagrammatically `shown in. Figure 6 as having transversely extending heating elements I,I-I I5 mounted therein and connected to a sutable source of electric power through conductors IIE-Ila The temperature ofthe preheating shoe IIZ` may likewise be controlled by a suitable thermostatically operated control means, to uniformly heat both sides of the blanks, and to take care of varying thicknesses or blanks and to prevent softening of the blanks during preheating. The shoe II2 being free to move vertically about its axis' of connection to the lugs II3-I I3,.may thus follow each blank as it is turned upwardly by the mandrel I5 into the nip between the heating roll I6 and said mandrel.

In carrying out the process of my invention the individual blanks IIi--IIA may nrst be formed by a cutting or blanking operation. The formed blanks may then be loaded in the feed box IES with their teeth facing the mandrel I5, and if desired or necessary may be weighted. They may then be ejected from, said box one at a time by the pusher plate |03 into engagement with the slot 81 of the mandrel I5. During this feeding or ejecting operation each blank is preheated to a temperature to make it readily pliable and below the softening. temperature thereof, by means of the heating elements. IIIl-I Ill and iI5-I I5. When the leading end of the blank is in iull engagement with the slot 8T of the mandrel i5, said mandrel may Ibe rotatably driven in a direction, which in Figure 6 is a counterclockwise direction. This will turn or move the blank I6 upwardly into engagement with the nip between said mandrel and the heating roll 40, it being understood that said' heating roll is brought up to the required temperature prior to the forming operation by the heating elements iT- 4l and is maintained at this temperature during' the entire forming operation, which temperature should be suincient to soften the particular blank being' formed, but should not be high enough to harm the blank. The mandrel I5 will then continue to rotate and turn the blank in the nip between said mandrel and the heating, roll 40 until. it has rotated one revolution plus the initial distance to the nip between said mandrel and heating roll and the overlap of the teeth I3, or more than one revolution where the'thickness of the blank demands additional heat to cause it to acquire the desired form. After the blank has been softened to acquire the form of the mandrel I5, the cam followers 63-63, will raise the heating roll 40 out of engagement with the formed blank. An air blast may then .be directed on the rotating formed blank, to cool it. When the

arms

43, 43 have been raised to their extreme elevated positions, the cams 6I-6I rotating with the cams 56-59 will elevate the frame structure I1 about the axis of the shaft 20 and lift the mandrel I5 out oi engagement with the upwardly opening slot 36 formed in the arm 21. The mandrel I5 may ccntinue to rotate during. the lifting operation and the air blastA from the pipe 66 may continue to gplay on the vrota'ting-blank, tocool'it. When-the being transversely I3`I I3 extendheating roll lilll and-mandrel. i5 have reachedthe upper limits of their vertical travel the blankv t0 will have acquired, its set. The blank may then be stripped from the free end of the mandrel I5 in the form of a completed binding element, by the admission of air to the head end of the cylinder effecting movement of the stripping sleeve 19 alongl said mandrel towards the free end thereof. The motor 69 and the shaft 66 continuing to rotate, and the cams 59 and 6I rotating therewitlnthe mandrel I5 will then vmove downwardly into engagementfwith the supporting rolls 35-35, and the heating Vroll 40 will then move into engagement with the top surface of said mandrel. The motor 69 may then be stopped with the slot 81 in alignment with. the feeding plate 25, for the insertion of a new blank therein.`

It may be seen from the foregoing that a simple novel and improved process has been provided for forming plastic binding elements from comblike blanks of thermo-plastic material, which contemplates feeding a thoroughly preheated plastic blank into a. blank receiving or gripping slot provided in the forming mandrel I5, rotating said mandrel while supported on the freely rotating supporting .rolls 35i- 35, and held into engagement therewith by the free turning heating roller d0, and bringing the plastic blank into engagement with and. drawing it through the nip between said mandrel and heating roll, and compelling the plastic blank, by raising the heat thereof to a soitening temperature upon progressive contact with said heating roll, to wrap itself around said mandreLso that after one or more complete revolutions, said plastic blank will have become sufficiently soft' to acquire the required shape. It further contemplates cooling the formed blank after completion of the forming cycle and in stripping the completed and cooled binding element from the free end of the forming mandrel.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention;

In a method of forming a curled binding element from a comb-like plastic blank, the steps or" feeding the blank over a pre-heat plate to guide the leading ends of the teeth thereof into a slotted mandrel, the temperature of the blank being maintained :below the softening temperature of the plastic material thereof during the feeding operation, rotating the mandrel about a fixed axis while pressing the blank against the mandrel with a heated roller to raise the temperature of the blank above the softening temperature thereof, removing the heated roller from engagement with the blank, then further rotating the mandrel with a cold blast of air directed against the blank, and then stripping the formed element from the mandrel.

References Cited in the file of this patent