US2964785A - Calendering unit - Google Patents

Description

Dec. 20, 1960 P. H. YOUNG 2,964,785

CALENDERING UNIT Filed June 30, 1955 INVENTOR PAUL H. YOUNG @(LJM ATTORNEY CALENDERING UNIT Paul H. Young, Braintree, Mass., assignor to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania Filed June 30, 1955, Ser. No. 519,113

3 Claims. (Cl. 18-2) This invention relates to a calendering unit. It is concerned more particularly with a calender unit for the production of variegated surface covering materials from rubber, linoleum, vinyl plastic materials, and the like.

In the manufacture of variegated surface coverings of the materials mentioned above, common practice is to form an initial sheet by calendering a mass of granules of a base and variegating color compositions, such as a mass of blue-colored granules intermingled with white-colored and grey-colored granules. The sheet or so-called blanket which is formed in this manner on the blanket calender has a striated or so-called jaspe. grained appearance. The graining runs along a direction substantially parallel to the length of'the formed sheet. In the manufacture of so-called marble-grained products, the jaspe sheet so prepared is cut into pieces, the length of which is about the same as the axial length of the sheeting calender to be used to form the final sheet; and these jaspe grained pieces are fed in overlapping relationship into the sheeting calen-- I (let at right angles to the direction of gr-aining. This calendering operation-is" eifectivefor altering the jaspe graining, producing a broken, veined, or grained appearance simulating naturalmarble in some respects.

- The character of the graining obtained in this operation depends to a large measure upon the manner of feeding the jaspe grained sheets into the sheeting calender rolls. If there is inadequate material in the bank of material at the nip between the rolls, the product will have a graining pattern entirelydifferent frorn the product obtained when there is an adequate bank of material in the nip. Also, when there is too mueh material in the nip, the tendency is for'the mass to churn, and there results a loss of the desired graining, It is important, therefore, to maintain a proper quantity of material in the bank at the nip at all times in-order to achieve the desired graining result and maintain a uniform character of graining. Frequently, this feeding operation is accomplished manually with one and sometimes two or more workmen guiding and pressing the pieces into the calender nip.

An object of the present invention is to provide a calendering apparatus which will insure the attainment of an essentially uniform graining in the production of variegated sheets.

Another object of the invention is to provide a device for calendering materials which will require a minimum intervention on the part of the calender operator.

An additional object of the invention is to provide a calendering unit which will force feed sheet material into the nip of the calender rolls, minimizing any tendency for the creation of a sheet which will have openings therein as sometimes results when the bank of material in the nip is not properly supplied.

A further object is to provide an apparatus for power feeding the nip between a pair of calender rolls to insure proper distribution of the material in the nip as it is delivered therefrom to the calender to obtain the desired graining characteristics.

According to the prevent invention, there is provided Paltented Dec. 20, 1960 adjacent to a pair of calender rolls and disposed close to the nip therebetween an infeed conveyor adapted to receive the sheets or other masses of material to be consolidated in the calender. Mounted above the in-feed conveyor for cooperation therewith is a floating control member. This is preferably in the form of a conveyor disposed at an angle with respect to the plane of movement of the in-teed conveyor and free for tilting movement toward and away from the in-feed conveyor so as to engage the sheets or other masses being fed by the in-feed conveyor to control the movement thereof and to insure proper pressure feeding of the sheets or other masses into the nip between the calender rolls.

An embodiment of the invention is illustrated in the attached drawing in which the single figure is a diagrammatic view illustrating the apparatus. The apparatus is not shown to scale in the drawing.

As shown in the drawing, there are a pair of calender rolls 2 and 3 which are rotated in the directions of the arrows which have been applied in the drawing. In this embodiment of the invention, a marbleized sheet 4 is being formed in the calendering operation from folded jaspe grained sheets 5 which are being forceably thrust and compacted into the nip between the calender rolls. The drawing shows the action diagrammatically. In actual production, the bank will be more irregular. In one type of rubber composition for the production of marble grained rubber tile, a mass about 4" thick is fed to the calender and is reduced to a marble grained sheet about .060" thick. The sheet feeding and controlling unit, diagrammatically illustrated, comprises anin-feed conveyor 6. This may be in the form of an open mesh metal conveyor which will provide a highly frictional surface for engagement with the sheets. This will insure proper power feeding of the sheets into the calender rolls. The metal conveyor 6 is mounted for movement between rolls 7 and 8, the roll 8 being driven by a suitable power source 9 through a slip clutch. The power unit 9 is preferably a motor and a variable speed drive associated therewith so that the speed of rotation of the conveyor 6 may be properly controlled. The slip clutch is preferably adjustable to vary the tension thereon and thus control the force with which the stock is fed into the nip. A belt and pulley or a sprocket and chain drive 10 may be provided for transmitting power from the unit 9 to the roll 8 of the conveyor 6.

drawing, the conveyor pivoting about the axis of the driven roll 13. The conveyor 11 may be a metal mesh type conveyor, similar to conveyor 6; and it is driven in the direction of the arrow shown on roll 14. The speed of movement of the conveyors 6 and 11 is synchronized by driving conveyor 11 through a belt and pulley or chain and sprocket drive 15 interconnected with the drive for the roll 8 of the in-feed conveyor.

In the operation of the device, the sheets 5 of rough stock, such as jaspe grained rubber tile stock, are deposited by hand or mechanically onto the upper arm of the in-feed conveyor 6. As shown in the drawing, the blankets of rough stock are preferably folded over and are fed in overlapping relationship onto the in-feed conveyor. The foremost blanket on the conveyor is thrust into engagement with the bank of material disposed in the nip between the rolls 2 and 3 and is amalgamated with the material in the bank. The control conveyor 11 is biased toward the in-feed conveyor 6 by its own weight, pivoting about the axis of the roll 13. It is shown as engaging the leading edge of the folded sheet which is overlapped on the sheet entering in the nip. It will be clear that the control conveyor 11 will have engaged the forward sheet which is disposed in the nip as such sheet approached the position shown. The control conveyor has been shown in an elevated position in the drawing to indicate its tilting action upon engagement with an oncoming overlapped sheet.

The control conveyor is driven and tends to pull the oncoming sheet 5 forwardly and presses the sheets firmly into engagement with the in-feed conveyor 6, insuring proper pressure application to the mass at the nip. The conveyor 11 controls the movement of the blanket and insures positive forward driving of it into the nip. As the bank in the nip tends to increase as additional blankets are fed thereto, the conveyor 11 serves to maintain close control over the action of the material entering the nip. The control conveyor 11 may be adjustable toward and away from the nip. This is desirable where different types of material are being made on successive runs or where dilTerent types of graining are being produced. With some patterns and materials, it will be desirable to have the working surface of the control conveyor 11 disposed closer to the nip between rolls 2 and 3 than shown in the drawing. While the invention is particularly useful in connection with the formation of a marbleized pattern from jaspe grained sheets, other type patterns can be made with the apparatus. In fact, it will be useful for calendering both monocolored and multicolored patterns by calendering sheeted rough stock where the sheets are fed into a bank for consolidation in the calender to a sheet of lesser thickness.

If it is found as the machine operates that the mass is not being fed into the nip with sufficient force, the tension on the slip clutch may be increased and additional driving force will be applied to the mass. If the bank at the nip does not maintain the desired size due to too rapid a movement of the material through the calender in relationship to the in-feed of material to the bank, then the speed of movement of the conveyor may be increased to insure proper feeding. If the bank in the nip builds up too fast, then the operator will reduce the speed of the conveyors 6 and 11 to the desired extent to obtain the proper feeding. The same is true of the force applied to the blankets fed into the nip. If too much force is being applied and undesirable graining is being obtained, the operator merely reduces the tension on the slip clutch and less pressure is applied to the sheets as they are delivered into the bank. The control conveyor 11, being free to pivot and in its pivoting movement being preferably directed toward and away from the roll 2, maintains a control at all times over the material being fed to the Calendar. It is obvious that a tilting roll or other moving surface may be substituted for the tilting conveyor shown. A conveyor made of open mesh metal is preferred because of the bight it makes into the material and the fact that it provides an extensive area in its lower run as shown in the drawing for engagement with irregularly lying pieces which may be disposed on the in-feed conveyor.

I claim:

1. A calendering unit for forming a surface covering or the like having a grained surface decoration comprising a pair of calender rolls defining a nip for the reception of a bank of material to be calendered therebetween; an infeed conveyor mounted adjacent to the nip and positioned for the reception of sheet material to be fed into the bank at the nip; means for driving the in-feed conveyor toward said nip; means for controlling the force with which the material is fed into the bank of material at the nip by; said in-feed conveyor comprising a slip clutch associated with the in-feed conveyor drive and effective for controlling the force with which sheet material fed by said in-feed conveyor is thrust into engagement with the bank at the nip; and means for pressing the sheet material into engagement with the in-feed conveyor to effect the forced delivery of the sheet material into the bank at the nip by said slip clutch controlled in-feed conveyor, said pressing means comprising a pressure-applying member disposed above the in-feed conveyor and biased toward the same, a moving surface on said pressure-applying member for engagement with sheet material on the in-feed conveyor, and means for driving the moving surface in unison with the movement of the in-feed conveyor.

2. A calendering unit in accordance with claim 1 inwhich said pressure-applying member comprises a pivoted inclined conveyor.

3. A calendering unit in accordance with claim 2 in which said pivoted conveyor includes an open mesh metal conveyor belt which provides a highly frictional surface for engagement with sheet material on said in-feed con veyor.

References Cited in the tile of this patent UNITED STATES PATENTS 1,108,163 Frick Aug. 25, 1914 1,248,856 Henry Dec. 4, 1917 1,319,122 Shelton Oct. 21, 1919 1,508,351 Reisbach et a1 Sept. 9, 1924 2,159,044 Paterson May 23, 1939 2,224,430 Garbutt Dec. 10, 1940 2,464,896 Schreiber Mar. 22, 1949 2,695,702. Ellen Nov. 30, 1954 FOREIGN PATENTS 145,631 Australia Mar. 7, 1952 UNITED STATES PATENT OFFICE CERTIFICATION or CORRECTION Patent No. 2 964 Q 785 December 20 1960 Paul H Young It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected belowo Column l line 72 for "prewent" read we present column 2 line 6O for "arm" read we run Signed and sealed this 9th day of May 1961 (SEAL) Attest:

. ERNEST W"; SWIDER Attesting Officer DAVID Lo LADD Commissioner of Patents

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