US2612101A - Sugar cane mill - Google Patents

Description

Sept. 30, 1952 A. BERNARD SUGAR cm MILL 4 Sheets-Sheet 1 Filed Feb. 5, 1947 .Z' 1vv51vTOR: Aueusrs BERN/3RD Sept. 1952 A. BERNARD 2,612,101

SUGAR CANE um. Filed lfeb. 5, 1947 4 Sheets-Sheet 2 Sept, 30, 1952 BERNARD 2,512,101

; SUGAR CANE MILL Filed Feb. 5, 1947 4 Sheets-Sheet 3 V I/wm/rak- [Al/wars BERNARD HWQ Patented Sept. 30, 1952 UNITED STATES PATENT OFFICE 2,612,101 SUGAR CANE MILL Auguste Bernard, Paris, France, assignor to Societe dite: Compagnie dc Fives-Lille, Paris, France, a corporation of France Application February 5, 1947, Serial No. 726,684

, In France February 22, 1946 1 In the cane sugar industry mills having three cylinders disposed in the form of a triangle are employed for crushing the sugar cane. The two lower cylinders carry the material to be crushed, it being crushed on their surfaces by a common upper cylinder, subjected to a crushing pressure by hydraulic pistons acting on its bearings. The sugar cane entering the mill is subjected to a preliminary crushing between the upper cylinder and the lower entry cylinder, or cane cylinder. The cane juice flows in the grooves formed on the surface of this cylinder, and the bagasse is scraped oiT by means of a longitudinal bar disposed between the two lower cylinders, and known as the turn plate, and then taken again between the upper cylinder and the lower discharge cylinder or bagasse cylinder for subjection to a second crushing, the cane juice flowing between the turner beam and the surface of the latter cylinder.

v The hydraulic pressure which is exerted on the bearings of the upper cylinder along the axis of displacementof the pistons may be resolved into two components perpendicular to the surface of the lower cylinders at the points of crushing of the material. In order to assure a larger value of the component relative to the discharge cylinder, corresponding to a stronger crushing, this cylinder is more strongly clamped down. The resultant of the reactions is thus inclined by a certain angle with respect to the direction of movement of the hydraulic pistons, and from this there results a longitudinal component, which applies the bearings against the vertical guiding surfaces provided in the, frame for said bearings and prevents the free vertical movement of said bearings. In order to reduce this risk of faulty operation the head of the mill may be inclined at an angle equal to that of the components of the two crushing reactions, this suppressing the lateral thrust component. The turnplate which is between the two lower cylinders is therefore vertical and the upper cylinder is submitted to hydraulic pressure parallel to the inclined axis of the mill head, in the direction of the bagasse cylinder. This inclination of the mill head gives disadvantages in construction, mounting, and maintenance.

In a mill with an inclined head, when, by reason of an increase in the thickness of the crushed layer, the upper cylinder separates from one of the lower cylinders against the action of the hydraulic thrust which is exerted on its bearings, it also separates from the second lower cylinder. Thus there results a decrease in the 2' Claims. (Cl. 100-165) 1 cylinder.

2 crushing pressure in one. of the zones, when the relatively greater thickness of the. canes or the bagasse passing into the other zone causes the lifting of the upper cylinder. As a result of. this, locally imperfect crushing is produced which decreases the output of the mill. 1

The control of the cylinders is made in the ordinary mills from the upper cylinder, coupled generally by a sleeve to a transmission shaft which is of square or non-circular section. The shaft of the upper cylinder carries, either on one or both of the ends of the mill, according to whether the control is single or double, a pinion engaging with the pinions mounted respectively on the shafts of the two lower cylinders. This is possible whatever the direction of rotation-o1 these two cylinders which is the same and in the reverse direction respectively to that of the upper However, by reason of the fact that? the two lower pinions turn in the same direction it is essential that their teeth do not engage; As these teeth'must have a considerable depthL-in order to remain in engagement with those of the upper cylinder during the lifting movements-to which the cylinder may be subjected in the course of crushing, it is necessary to separate the lower cylinders from each other by a relatively large space and to adopt in consequence a turn plate of large width. As a result of this there-isa rubbing of the bagasse on a larger surface and an increase in the power absorbed by the mill. It must be remembered that in practice ii the smaller the width of the turn plate the betteris the operation of the mill.

The improvements which form the subject of the present invention permit of avoiding these disadvantages and of considerably improving the output of the mill.

One object of the invention is to provide a sugar cane mill in which the head of" the mill is upright and the turner-beamis incline d'a'nd of small width. j According to another characteristic of the invention the. bearings of. the upper cylinder which are subjected to hydraulic pressure are mounted so as to pivot under hydraulic pistonsand are centered by bearing on a socket. in their normal lowered position.

According to another characteristicthe connection of the lower cylinders to the upper cylinder is assured by alternatev pinions one vof the lower cylinders being connected to the upper cylinder by pinions at one end of the. mill, and the other at the other end.

inder under the action of threadedwedges 28-49, on which rest the lower bearings H3 or 2|.

Between the two frames (Figs 2 and 3) and in the interval provided between the two lower cylinders 4 and 5 of the mill there is mounted a turn place 20 with an inclined body. The turn plateis in the usual manner formed with a toothed edge. The turn plate bears, under the action of an adjustable longitudinal stay, not

shown, against the channelled surface of the entry cylinder and is inwardly curved so as to guide the bagasse towards the outlet cylinder.

Fig. 5 is a transverse section on line V-.-V of VI-VI of Fig. 5;

Fig. 7 is a detail view in section taken on line VII-VII of Fig. 6. 1

According to the form comprises two symmetrical frames l resting on the ground or on the longitudinal members of the bed plates 2 which are fixed or bolted and which may be interconnected atthe upper part by stays 3. These frames carry three parallel cylinders, two lower cylindersa cane cylinder 4 and a bagasse cylinder 5-as well as an upper cylinder 6. These cylinders are journalled at their ends in bearings mounted in the frames. The latter have upright heads. The head of the frame 1 (Figs. 5 to 7) carries a vertical cylinder 8' in which moves a piston 9 under the action of hydraulic pressure on its upper face and which bears, through the intermediary of a ball 10 forming a knee joint, against the upper bearing II of the upper cylinder. This bearing is guided at the level of the knee joint by two transverse ribs l2 of small thickness, sliding against the vertical surfaces l3 of the sides of the recess M in the head of the frame which contains the bearings. The lower bearing I5 is formed at its base 'with a rounded shape, to which corresponds a socket [B of the same shape as the said recess.

The assembly of the two bearings which are mounted on the journal I! of the upper cylinder of the mill is thus mounted so as to float in the lower portion of the recess and can, when itis raised into the position shown in Figure 5, have a swinging movement about the knee joint ,to allow for a swinging movement of the related 'a vertical longitudinal plane, the ribs l2 slide vertically in opposite directions on the vertical surfaces I3. On the other hand in its lowered position the bearing assembly 'I l-l5 is centered by the engagement of its lower surface in the socket [B of the recess and the axis of the upper cylinder is then in the normal position in the plane of the axes of the hydraulic pistons. Each of the bearing assemblies l8--l9, 20--2l, of the lower cylinders of the mill is enclosed in a housing 22-23, of the frame, closed by bolted caps 24-45, in which housing the bearing assembly "is guided by the inclined surface 26-2! in order to permit displacement of said bearing assembly in the direction of the axis of the upper cyl- Fig. 6 is a detail cross-section taken on line of construction shown (Figs. 1 to 4) the mill according to the invention The turn plate body is a beam jointed at each end on a pivot 3| carried on a support 32, the

longitudinal position of which in the mill may be adjusted by the screws 33 bearing against the walls of a support 34 provided on each frame,

the exterior of the frame (Figs 1, 3 and 4) there are fixed pinions connecting the lower cylinders to the upper cylinder. These connections are alternated at both ends of the mill. The upper cylinder 6 carries a pinion 35, 36 at each end, the pinion 35 being in engagement at one of the ends of the mill with a pinion 31 of the bagasse cylinder 5, and at the other end the pinion 36 is in engagement with'a pinion 38 of the sugar cane cylinder. Preferably, the connection 35- 31 to the bagasse cylinder which, by reason of the stronger scraping pressure on this cylinder ab-,- sorbs more of the power, is provided at the end of the frame where the upper cylinder is coupled to the end of the shaft 39, and in such a way that this power is transmitted directly and not along the length of this cylinder. These pinions have deep teeth so as to remain in engagement whatever the movement of lifting or pivoting of the upper cylinder which is, moreover, limited by the movement of which its bearings are capable. By means of this alternate arrangement of the pinions of the lower cylinders the distance between these cylinders is not limited to a minimum by the risk of contact of these pinions but only by the thickness to be given to the turn plate. The trash turner is reduced to the minimum in order to reduce as much as possible the power absorbed by the mill.

In operation, the sugar cane which arrives at the mill on a conveyor is taken between the upper cylinder 6 and the entry cylinder 4 and subjected to a preliminary crushing. The raised position of the entry cylinder which results from the upright construction of the head of the frame and the inclined turn plate facilitates the penetration of the sugar cane into the crushing zone. The bagasse, engaged by the surface of the entry cylinder, is guided by the upper surface of the turn plate, the inclination of which facilitates its sliding movement, and passes between the upper cylinder and the outlet cylinder where it is subjected to complementary crushing. The arrangement of the cylinders resulting from the construction of the mill with an upright head, by reducing the level of the trash turner on which the bagasse leaving the first crushing zone slides, facilitates the introduction of the latter between the upper cylinder and the outlet'cylinder. Moreover, the inclined turner beam is easy of access from the side of the mill entry, this facilitating the adjustment of its position.

By reason of the alternate arrangement of the pinions controlling the lower cylinders, the

inequalities of the two crushings compensate each other. It is known that the reaction of the engaging teeth of the pinions, which has a component in a direction opposite to that of the hydraulic pressure which is exerted on the bearings of the upper cylinder, decreases the pressure exerted on the crushed layer at one end of the mill with respect to the crushing pressure at the other end. This inequality of pressure is compensated by means of the alternate arrangement of the pinions according to the invention. In effect it produces, in the second crushing, an inequality of pressure in the reverse direction, since for the control of the outlet cylinder the pinions are arranged at the opposite end of the cylinder with respect to the pinions controlling the entry cylinder.

Thus the mill forming the subject of the present invention enables regular crushing to be obtained over the whole width of the layer, the output being thereby improved. It is to be noted that this regulation of the crushing is obtained by reason only of the alternated control and without the necessity for different hydraulic rams for the heads of the two frames, as has been often suggested for compensating the effect of the reactions of the pinions when the latter are both at the same end of the mill.

A further improvement in the output is brought about by the decrease in the width of the turn plate, which thus reduces the power absorbed by the latter. The width of the mill is moreover correspondingly decreased, this assuring a more rapid re-engagement of the bagasse and giving the effect of the least possible re-absorption of the sugar juice by the layer before the second crushing. All these factors combine to increase the output to a considerable degree.

When an excessive thickness of bagasse is engaged between the upper cylinder and one of the lower cylinders, i. e. either the entry cylinder or the outlet cylinder, the upper cylinder is lifted from said lower cylinder in an oscillating movement while each bearing assembly of the upper cylinder may move angularly about its knee joint. The upper cylinder is thus separated from the lower cylinder, over which passes the excessive thickness, without moving away from the other lower cylinder, and the pressure exerted on both said lower cylinders remains substantially the same. Thus the crushing pressure remains constant on the two lower cylinders, even during the momentary lifting of the upper cylinder caused by an excessive thickness of the layer, and the crushing is regular. When there is no excessive thickness, the bearings of the upper cylinder occupy a lowered position in which they are centered on the axis of the hydraulic piston by the socket of the base of the recess which contains them. The pressure which is exerted on the outlet cylinder is thus greater than that which is exerted on the entry cylinder by reason of the difierence of the angular displacement of these two cylinders with respect to the vertical axis of the head of the frame. This difference of pressure which is found in existing mills has been recognised as being necessary for the efficiency of the crushing.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I claim:

1. A sugar cane mill comprising in combination, a frame having upright heads, a downwardly hydraulically pushed piston in the top part of each of said heads above a recess thereof, a bearing loosely placed in said recess, a ball interposed between a front surface of said piston and an upper socket in said bearing, means to keep said ball substantially in the transverse plane of the mill passing through the axes of said pistons, an upper cylinder journalled in said loose bearings, an entry lower cylinder and an outlet lower cylinder journalled in fixed bearings in said frame on each side of the vertical plane through the axis of said upper cylinder and said outlet cylinder at a level below said entry cylinder, in such a manner that the resulting force from the reactions of said lower cylinders is substantially vertical and opposite the resulting force of the hydraulic pressure, whereby said upper cylinder is equilibrated in a middle position and may oscillate both longitudinally and transversely to the mill according to any variation in thickness of the bagasse under said upper cylinder without change in the pressure exerted on the bagasse passing over said lower cylinders.

2. A sugar cane mill according to claim 1, in which said means adapted to keep the ball substantially in the transverse plane of the mill passing through the axes of said pistons are formed by transverse ribs on both sides of said loose bearings at a level corresponding substantially to the level of the center of said ball and in contact with vertical guiding side surfaces of the recessed part of said head.

AUGUSTE BERNARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 308,049 Barreiras Nov. 18, 1884 421,705 Hatton Feb. 18, 1890 733,125 Bekker July 7,1903 974,349 Bowen Nov. 1, 1910 1,044,127 Boyer Nov. 12, 1912 1,422,979 Hurter July 18, 1922 FOREIGN PATENTS Number Country Date 12,031 Netherlands Oct. 15, 1924 21,802 Netherlands May 15, 1930

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