US2356244A - Sheet pressing machine - Google Patents

Description

Aug. 22, 1944. C, P, JOHNSON 2,356,244

SHEET PRESS ING MACHINE Filed Fb. 23, 1942 s'sheq's-sneet 1 e Aug. 22, 1944-. c. P. JOHNSON SHEET PRESSING MACHINE Filed Feb. 23, 1942 5 Sheets-Sheet 2 r/ OODDDuDOOD n@ N. m NYS Aug. 22, 1944- c. P. JOHNSON 2,356,244

SHEET PRESS ING MACHINE 4 Filed Feb. 25, 1942 5 Sheets-Sheet 3 Aug. 22, 1944. c. P. JOHNSON 2,356,244

SHEET PRESSING MACHINE Filed Feb.'2s, 1942 5 sheets-sheet 4 Aug. 22, 1944.

C. P. JOHNSON SHEET PRESSING MACHINE Filed Feb. 2.3, 1942 5 Sheets-Sheet 5 Patened ug. 22, 194?- UNITED STATES PATENT OFFICE 2,356,244 snaar raassrNG MACHINE Clarence P. Johnson, Anburndale, Mass. Application February 23, 1942, Serial No. 431,965

I 2 Claims.

This invention relates to improvements in continuous sheet forming and pressing machines.

4The improvements are particularly directed to machines for handling compositions of matter, the ingredients of which may consist of fibrous materials and suitable binders which are mixed in the presence of a quantity of water to thoroughly coat the ilbres with the binder which compositions are fed in a sloppy mix to form a sheet which is subjected to pressure to condense the sheet, squeezing out the water and closing up any .pockets or voids so that the finished sheet will be uniform in quality throughout its thickness.

Such compositions have heretofore been handled.

in fixed presses in which the pressure may be gradually applied and maintained for a period of time sufilcient to properly condense the compositioninto a solid block or sheet. It has been found that if the material is pressed too quickly that the' binder or other ingredients will be squeezed out with the water, whereas' the more gradual application of the pressure will allow the binder to set and grip the iibres while the water is being slowly removed from the mixture. It will be understood that automatic machines for carrying out' the forming and pressing of the sheet would reduce the cost of production as compared with the forming of the material in fixed pressed. However, prior sheet forming machines, such as paper making machines, wouldv not be satisfactory for this purpose as such prior machines do not provide means for applying a continuous and gradually increasing pressure as the sheet moves through the machine. It is an object of the present invention to disclose improved apparatus for producing a continuous sheet of the finished product in which all the operations from the introduction of the raw material to the delivery of the finished. product are automatically carried out, such apparatus including the provision of means for mixing the ingradients into a ilowable composition which is delivered upon a moving screen to form a web or sheet, means being provided to subject the formed sheet to gradually increasing pressure as it moves through the machine.

It is further an object of the present invention i to provide apparatus including upper and lower screens between which'the material to be formed is introduced and to provide conveyers composed of sectional plate members which press against the screens from opposite sides so as to compress the material being formed into the sheet between the screens as it is'moved along, the pressure 28 bymeans'of which the gears gradually increasing up to the point at which the iinished sheet isdelivered from the machine.

Further objects and advantages of my improvements will be more readily apparent from the following description of a preferred embodiment thereof as illustrated in the attached drawings, in which:

Fig. lisa fragmentary plan view of the apparatus showingthe feeding end of the machine;

Fig. 2 is a side elevation of the apparatus disclosed in Fig. l;

Fig. 3 is an enlarged fragmentary view, partially in vertical section, showing the means for feeding the material;

Fig. 4 is a diagrammatic view disclosing the relative association of the lower conveyer which is fixed in positlon and the upper conveyer which is mounted' forvertical movement with respect to the iowerconveyer;

Fig. 5 is a fragmentary side elevation of the apparatus taken at the delivery end thereof;

Fig. 6 is a vertical sectional view taken on the plane indicated 6-6 in Fig. 2: Fig. '7 is a vertical sectional view taken on the plane" indicated 1-1 in Fis. 5; l

Figi-8 is a perspective view of one of the upper plates; Fig. 9 isa plan view of one oi the lower plates; and

Fig. 10 is asectional view taken on the plane indicated lil-ri in Fig. 9.

V'li'he machine Vmay be made of any desired size but it is` preferred long; for example l0 or more. The width of the sheet which is -to be delivered Idetermines the width of themachine. Increasing the width of the sheet considerably adds to the expense of the machine. vA suitable width of the sheet may be 16", although itwill be understood that machines for wider or narrower widths of sheets may be readily designed. l

rI he main frame i0 of the machine as disclosed in the drawings' comprises a number of pairs of vertically disposed posts I2. These posts I2 are suitably spaced throughout the length of the machine and are tied together by transverse cross beams il andv crossplates i! between each pair of posts i2 andthe horizontal rails I6. A suitable driving motor iB is mounted on the frame' at the delivery end of'the machine* to drive by belt 20 a cross shaft): from which motion is'transmitted by suitablegears to the vertical shaft 2l. The vertical shaft 2l has spaced worm ' gears 2i and 30 and 32 are driven.I The 'gear Il is nxed to one end of an to have the machine relatively upper cross shaft 34 while the gear 32 is similarly fixed to one end of a lower cross shaft 38. 'I'he upper cross shaft 34 has a pair of sprocket gears 38 while the lower cross shaft 38 has a similar pair of sprocket gears 40. The gears 38 provide driving means for the upper pair of conveyer chains 42 while the sprockets 40 similarly drive a pair of lower conveyer chains 44.

At the feeding end of the machine the conveyer chains 42 are carried by the sprocket gears 48. idler gears 48 being provided as desired to support the top run of the conveyer chains as they pass from the delivery end back to the feeding end. The gears 48 are mounted on the cross shaft 80 supported as hereinafter to be described. The lower conveyer chains 44'are carried at the feeding end by the sprocket gears 82 mounted on cross shaft 84 which is suitably carried by the fixed frame.

'I'he lower conveyer chains 44 are attached .to the sectional plates 88. These plates 88, as hereinafter described, are screen plates to permit the passage of water therethrough. As shown in Figs. 9 and 10 the plates 88 may be formed with slots 88 and drain holes 81. The plates 88 throughout the top run of the conveyer chains 44 from the feeding to the delivery end of the machine are brought together into abutment to form a fiat movable supporting table for the material handled by the machine. The plates 88 are supported by a lower track comprising the spaced rails 88, suitable channel members 80 being provided between the rails 58 to collect and receive the water that is squeezed from the materia] being pressed through the plates 88. The conveyer chains '44 together with the plates 88 are mounted within a screen 82 which forms a bed for the material as it is carried along on the moving table formed by the plates 88.

The upper conveyer chains 42 carry the sectional plates 84. 'I'hese plates 84, however, need not be screen plates as are the plates 88, and as shown in Fig. 6 are carried in a track between the upper rails 88 and lower rails 88 which in turn are carried by the horizontal beams 'l0 which form part of the movable frame which carries the upper conveyer members as a whole as will be later described.

A flexible screen 'l2 extends around the upper conveyer made up of the chains 42 and the plates 84. The lower screen is driven by the drive roller 74 while the upper screen is similarly driven by the drive roller 18. The rollers 14 and 18 are suitably driven by chains 18 and 80, respectively, from the sprocket gears 82 and 84 which are mounted on the driving cross shaft 38 and 34. The lower screen 62 is guided by suitable idler and tensioning rollers 88. At the feeding end an idler roller 88 for the screen 82 is positioned to cause the screen 82 to move downwards towards the point at which it passes under the idler roller 80 where it meets the moving-table made up of the lower plates 88. The upper screen is carried by suitable guide rollers 92.

The longitudinal channel beams 'l0 which carry the guide rails 88 and 88 for the upper conveyer plates 64 are carried by the under side of a plurality of cross beams 94. These cross beams 94 have brackets 98 fixed thereto having threaded adjustment bearings 98 for the rotatable vertical adjusting screw rods |00. The rods are mounted in suitable bearings |02 fixed to the main frame and are provided at their upper ends with the gears I 04 to which motion is transhorizontal shafts |08, the shafts |08 having the gears I|0 driven from the bevel gears |I2 on a cross shaft I |4 which may be turned by the pressure adjusting wheel ||8. 'I'he movable frame including the beams 10 may be guided for vertical movement by the rods ||3 fixed to the beams 18 which slide in bearings |I8 carried by the fixed beams I4.

At the feeding end of the machine there is provided a mixing tank |20 from which the mixture is transferred by the conveyer |22 to a second mixing tank |24. The ingredients of the l composition, after being properly mixed together,

mitted from the worm gears |08 carried by the 78 are delivered from the bottom of tank |24 by means of the feeding and depositing wheel |28. The wheel |28 delivers the material onto the screen 82 which rests on the fiat table formed by the lower plates 88. Any suitable means may be provided such as the spreader wheel |28 and-the tamper |30 to spread the more or less fluid mix in an even layer over the surface of the screen 82. Motion is transmitted to the movable parts at the feeding end of the machine from the shaft 84 which is driven by the conveyer chains 44. The drive may comprise, as shown, albeit |32 from a pulley |34 on shaft 84 which belt transmits movement to pulleys on the shafts |38, |38 and |40. The shaft |38 through the belt |42 transmits the drive to the bucket conveyer |22. The shafts |38 and |38 through suitable gears transmit motion to the vertical agitators |44 in the mixing tank |24. The shaft |38 transmits the drive through belt |48 to mechanism |48 by means of which the tamper |30 is reciprocated in a vertical direction.

The feeding mechanism does not form an essential part of this invention. Various means may be used for mixing the materials and delivering the mixture into a smooth layer on the conveyer screen 82. It will be understood, however, that I do intend that the mixing and .feeding mechanism shall be immediately associated with the machine for automatic and continuous operation. Furthermore I prefer to use means for controlling the speed of the feeding wheel |28 with respect to the rate of movement of the conveyers.

After a smooth layer oi' the mixture has been formed on the screen 82, it passes beneath the lower run of the top screen 12 where it is subjected to pressure between the top plates 84 and the bottom plates 58. 'Ihe adjustable frame which is moved up and down by the pressure adjusting wheel I|8 carries with it the shafts 34 and by means of which the chains 42 and the upper plates 64 are mounted. The top pressing table formed by the upper plates 84 is inclined with respect to the bottom pressing table formed by the plates 88 so that as the sheet which is being pressed moves along, it is subjected to gradually increasing pressure until it is delivered from between the pressing members. By turning the wheel ||8 the thickness of the finished sheet may be controlled. Adjusting the movable-frame, however. does not change the relative angle between the plates. and 88. -At the delivery end of the machine the sheet |80 is fed from between the rollers 14 and 18 around which pass the screens 82 and l2. Automatic means may desirably be provided for cutting the sheet into sections as it is delivered. For example, I may provide the vertically reciprocable cutting-off knife |82 to which motion is transmitted by belt |84 from shaft 22. The sheets'as they are cut ofi' are delivered onto the table |88.

continuousLv agitated so that the fibrous material of the mixture will remain in suspension and will be thoroughly coated with .the binding ingredients. vThe mixture in the tank |24 contains a large quantity of water.4 The rate of delivery of the material from the feeding tank |24'is controlled by the speed of rotation of the feeding wheel |26. It will be understood that means will be provided to vary the speed of the wheel .|26 with respect to the rate of travel ofthe conveyer to which the material is delivered by the wheel |26. The wheel |26 lays the mixture vuponthe surface of the screen 62 which is supported on the flat surface formed by the plates v56 of the lower conveyer. The spreader wheel |28 serves to level oif the material while the tamper |30 distributes the material into an even sheet. Fig. 4 is a diagrammatic view which shows the relationship of the upper and lower conveyers, or more particularly the upper and lower plates 64 and 56. It will be noted that the opposed surfaces of the plates 64 and 56 inclinetowards each other towards the delivery end. Therefore, when the formed sheet iirst enters between the opposed plates 64 and 56, it is subjected in only a slight pressure; but as the sheet material is carried along between the plates, it is subjected to continuous and gradually increasing pressure. The thickness of the finished sheet is'determined by the space between the plates 64. and 56 at the delivery end of the machine and the' greatest pressure is applied at the deliveryend. If it is found that a harder and more dense sheet is desired, more material is fed to the machine by increasing the speed of the feedingv wheel |26 without changing the rate of travel of the conveyer or the space between the upper and lower plates 64 and 56. It will be understood that by delivering more material while stillcompressing the material .to the same thickness -that the Vfinnished sheet will be denser. If it isdesired to 'change the thickness of the finished sheet this may be done by raising or lowering the frame which carries the upper conveyer' and the upper screen. Referring to Fig. 4, it will'be understood that the upper conveyer comprising the plate 64 carried by the chains 42, the screen 12 and the supporting wheel therefor all may be moved vertically with respect to the bottom conveyer without changing the' relative anglebetween the plates 64 and 56. The rate of movement of the conveyer plates 56 and 64 may be suitably controlled so that the material is retained under pressure for the desired amount of time. Preferably the rate of movement vwill be slow, such as to 10 feet per minute.

The character'of the screens, particularly the size of the screen openings, is `determined to some extent by the materials being handled in the machine. Ordinarily I prefer-"to have the lower screen of relatively ne mesh which willv allow the water to run out while the solid material is held back. The screensare not under tension and therefore do not require a high degree of tensile strength and will last a considerable time in use as they are carried along between the plates 56 and 54. Itis-important.

however, to keep the lower screen clean and it is preferred to clean the lower screen immediately after it leaves the delivery end of the machine and starts back towards the feeding end. This may be done by directing a strong spray of water from the pipe |60 (see Figs. 4 land 5) against the innersurface of the screen so that any material which has plugged the openings of the screen will be removed by the pressure of the water and all other material which has stuck` to the screen will be washed off before it hardens thereon. It* is also important to properly design the top surface of the lower plates 56 which act as drain plates. As disclosed, I prefer to make these plates by cutting slots transversely with respect to -the movement of the plates and to form drain openings 51 from the bottoms of the slots. The slots should not be so wide that thel pressure causes the lower screen to be forced into the slots forming ridges across the screen.

Iclaim:

1. In a continuous sheet forming and pressing machine, a main frame, a lower sheet conveying member comprising a plurality of plates attached to a flexible chain, a horizontal track fixed to said frame for supporting the plates of said lower conveyer as they move through the machine from the feeding to the delivery end thereof whereby said plates form a flat table for supporting the sheet as it is fed through the machine, a frame mounted for vertical move-y ment with respect to said main frame, the mounting for said movable frame comprising a rplurality of vertical posts at spaced points throughout the length of said movable frame, adjustable means for raising and lowering said last named frame with respect to said main frame by turning said posts. an upper conveyer member carried by said second frame comprising a plurality of plates attached to a flexible chain, track means xed to said second framefor guiding the movement of the plates of said upper conveyer as they move from the feeding to the delivery end of the machine, said track means being arranged to hold said plates against upward movement with respect to said second frame, said track means being inclined with respect to said horizontal track of the lower contravels towards the delivery end of the machine.

2. In a continuous sheet forming andl pressing machine, a relatively long fixed main frame.

`a lower sheet conveying member comprising` a plurality of plates attached to a flexible chain, horizontal track means'fixed to said main frame for supporting the plates of said lower conveyer as they move through the machine from the feeding to the delivery end thereof, a movable upper` frame suspended from said fixed main frame, an upper conveyer carried by said movable frame comprising'a plurality of plates attached to a flexible chain, track means fixed to said movable frame for guiding the movement of the plates of said upper conveyer as they move from the feeding to the delivery end of the machine, said track means being arranged to hold said plates against upward movement with respect to the movable frame, said upper track. means being inclinedthe iiat surface formed by the lower plates to simultaneously turning all of said screw memconne the sheet therebetween and subject the bers to raise or lower said movable frame with sheet to gradually increasing pressure as the y respect to said fixed trame while maintaining sheet travels towards the delivery end of the 'a predetermined degree of inclination between machine, a plurality of vertically disposed screw 5 the tracks o! the fixed and movable trames. members through which said movable frame is CLARENCE P. JOHNSON. suspended from the nxed frame and means for

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