Roller (mechanics)

“ As rapidly as possible the cylinder is worked over on the roller, without forcing it, and also turned, so as to prevent even the weight from grinding it unduly on one side.
More or less of the emery will embed itself in the lead, and thus act as an abrasive. The process is called "lapping."
Surface Gages.—Frequently, in laying out, it is necessary to scribe lines at a given distance from some part of the work; or, the conditions are such that a rule, a caliper, or dividers will not permit accurate measurement to be made. ”

“ The distance between the centres of the rollers is regulated by screws, furnished with wheels on their upper ends, similar to what is seen in the drawing dies at C. The two rollers have pinions on their axes, which make them revolve together; they are set in motion by an endless strap passing round a drum, upon whose axis is a pinion working into the teeth of a wheel fixed upon the axis of the lower roller. ”

“ The rollers move along with a velocity equal to one half the relative velocity of the surfaces. This way of reducing frictional resistance has been applied to all kinds of mechanical contrivances, including bearings for shafts, railway axle boxes, and axle boxes for tramcars. An example of a roller bearing for a line shaft is illustrated in figs. 8 and 9. The main casting, A, and cap, C, bolted together, form a spherical seating for the part of the bearing E corresponding to the brasses in a bearing of the usual type. ”

“ The detaching portion of the mechanism consists of the three rollers Q S and T, but the fluted segment N1 also aids in this portion of the work. The roller S is known as the “steel detaching” roller, and receives an intermittent motion in both directions from a cam at the end of the machine. The roller Q is known as the “top detaching” or the “leather” roller, and is covered with leather, being borne by levers R, to which the necessary oscillation is given by a cam and the connecting rod R1. ”

“ The lap, being passed to the feed rollers, is delivered by them intermittently in short lengths corresponding to that of the staple. This intermittent rotation is obtained by the use of a star wheel, which is revolved by a train of gearing from the cylinder shaft. The extent of the forward movement is regulated by the length of the fibre, the roller making such a portion of a revolution as causes its surface to move that distance, usually from 1⁄8th to 1⁄10th of a revolution. ”

“ At the outer extremity of the axle of the roller a, a rigger c, is attached, whence a band passes to a pulley d, on the crank shaft e, to which a flywheel f, is affixed, for the purpose of rendering the action uniform. Rotatory motion being given to the crank shaft, the upper roller is turned, the lower roller moving at the same time by the friction against the edges of the cutters. ”

“ The end of a slip of metal is presented between the rollers while they are in motion, not on that side of the roller which would operate to draw in the slip between them, as in the rolling-press above described, but on the contrary side, so that when one of the flat sides of the under roller fronts horizontally the circumference of the upper roller, an opening is formed, through which the slip of metal is to be inserted until it bears against a fixed stop at the back of the rollers. ”

“ The end rollers guide the table when making any portion of a revolution, and carry such part of the weight as may not be taken up by the centre. A recess is shown in side wall to facilitate the inspection of end rollers. In the earlier forms of engine turn-tables, the revolving movement was effected by attaching to the upper portion of the girders a strong winch, which acted upon gearing fixed either to the end rollers, or direct on to a toothed ring forming part of the roller-path. ”

“ When motion is given to the worm then rotation is produced in the roller wheel at a rate proportionable to the pitch of worm and diameter of wheel respectively.
In the arrangement for transmitting rectilinear motion from a screw, rollers may be employed whose axes are inclined to the axis of the driving screw, or else at right angles to or parallel to the same. When separate rollers are employed with inclined axes, or axes at right angles with that of the main driving screw, each thread in gear touches a roller at one part only ”

“ The most perfect plan is to place a small roller between each of the larger; with this arrangement the friction is practically nothing. The action of rollers upon the boxes is always a pure rolling friction, which cannot be the case with balls after the slightest groove is worn in the casing.
One reason for rollers being little used is that they tend to work out of line with the axle and box, which causes some ends to get a little in advance of the others, when they can no longer work perfectly. ”

“ The rollers now begin to turn and to deliver threads, which receive immediately a portion of their twist from the spindles; the carriage retires from the roller beam with somewhat greater speed than the surface speed of the front rollers, whereby the threads receive a certain degree of stretching, which affects most their thicker and less twisted portions, and thereby contributes greatly to the levelness of the yarn. ”

“ For this reason, as well as securing the correct impulse radius and therefore angle, when replacing the ruby pin, and having it set securely and mechanically in the roller, it is necessary that the pin and the hole in the roller be of the same form, and a good fit. Fig. 23 illustrates the difference in size of rollers. In the smaller one the conditions imposed are satisfied, while in the larger one they are not. In the single roller the safety action is at the mercy of the impulse and pallet angles. ”

“ In this case, the hardened roller die is mounted in the upper bed of the transfer press, in such a way as to be capable of rotation round its axis, and a similar roller of softened steel is similarly placed in the under bed. The rollers are now made to bear on each other by the action of the upper screw, and while in hard contact, the lower one is caused to revolve, which, carrying round the upper by friction, receives from it the figured impression in relief. ”

“ The printing roller C is the only part of the machine directly connected with the motor or main drive of the works through the cog-wheel on its axlethe “ mandril ”-all the other parts deriving their motion from it, either by friction as in the case of the cylinder or by a spur wheel as in that of the colour-furnishing roller. ”

“ On the top of the detaching roller is a large steel fluted roller carried at each end by a small arm called a "horse tail." In the original machine this roller simply kept its place upon the detaching roller by its weight, and when the machine came to be run at high speeds it was found that owing to its lightness the contact thus obtained was not reliable, the flutes or ribs of the roller slipping upon those of the detaching roller, which for good work is undesirable. ”

“ Both rollers and balls, and the paths on which they roll, therefore, are made of hard material; further, balls and rollers must all be exactly the same size in an individual bearing in order to distribute the load between the points or lines of contact as uniformly as possible. The finest workmanship is required therefore to make good roller or good ball bearings. ”

“ Fastened to the wheel is a cam, concentric for about seven-eighths of its circumference and indented for the remainder. Into a groove in the concentric portion of the edge is pressed a roller which is pivoted at the free end of a strong curved spring. When the mainspring is fully wound the roller rests in the curved depression of the cam and the effort required to lift the roller up the incline absorbs some of the mainspring's power. ”

“ The fact that the arm or detent, k, arranged on the roller in the manner described, moves towards and away from the center or axis of the roller in consequence of the motion of the roller itself, is not patentable independently of any useful combination in which it performs a necessary part. ”

“ It was formed of thin brass and had a radius about four times that of the roller, but made adjustable as to length. The sector was placed concentrically on the axis, and rested on the upper end of the roller. It turned by frictional adhesion along with the roller, but was sufficiently loose to allow of its being moved back by hand to any position without affecting the roller. While the roller passes over an angular space equal to the mean interval between two dots, any point of the sector must pass over 16 times that interval, that is to say, over an angle represented by 360° × 16/256=22° 30′. ”

“ Fig. 243 represents a groove-cam, and it is to be observed that the roller cannot be maintained in a close fit in the groove, because the friction on its two sides endeavours to drive it in opposite directions at the same time, causing an abrasion that soon widens the groove and reduces the roller diameter; furthermore, when the grooves are made of equal width all the way down (and these cams are often made in this way) the roller cannot have a rolling action only, but must have some sliding motion. ”

“ In the roving machines the relative positions of the spindle and front rollers are fixed, but in the mule an important variation in this practice occurs. The carriage I receives by suitably arranged mechanism an alternate movement from and towards the roller B. During the period they are delivering roving it is drawn away from them until it has travelled about 63 inches, when its motion ceases. While this traverse is taking place the spindles are revolving, and twist is therefore being introduced into the roving. ”

“ Wheelwrights of old soon found that a wheel need not be solid, that strong spokes, a sound rim, and a metal tire embody the utmost strength and lightness. Roller and ball bearings much extend the benefits of simple wheels; they lessen friction in the best typewriters, bicycles, and elevators; in wagons, carriages, and automobiles roller bearings are so helpful that their use should be universal. Of notable efficiency is the Hyatt bearing, formed by winding a steel strip into a spiral roller. ”

“ The rollers are carried in brass bearings, fixed to the roller beam, and are weighted as in the drawing148 frame. Top clearers are fitted above the rollers, which are quite covered by polished cast-iron covers. The bottom rollers are kept clean by the aid of a revolving clearer kept closely pressed against them by a two-armed spring, the ends of the arms being grooved to form bearings for the axes of the clearer roller. ”

“ This is 5 feet long by 1 foot in diameter; it is thick in the metal but hollow in the axis. The same roller can serve only for two plates at one casting, when another is put in its place, and the first is laid aside to cool; for otherwise the hot roller would at a third casting, make the plate expand unequally, and cause it to crack. When the rollers are not in action, they are laid aside in strong wooden trestles, like those employed by sawyers. ”

“ The number of spindles in a throstle frame 12 feet long, is about 60 on each side. The drawing rollers are coupled together as in the bobbin and fly frame, so that each row forms one continuous cylinder. There is a complete roller beam on each side; each of the rollers of the front row is pressed by its top rollers with a weight of ten or [366] twelve pounds; but those of the middle and back rows bear weights of only one pound. ”

“ Rollers up to 5 tons in weight are employed and are now generally driven by power. The width of the sheet or plate is regulated by moving guides which are placed in front of the roller and are pushed along by it, while its thickness is regulated by raising or lowering the roller relatively to the surface of the table. Since the surfaces produced by rolling have subsequently to be ground and polished, it is essential that the glass should leave the rolling-table with as smooth a surface as possible, so that great care is required in this part of the process. ”

“ Theoretically there is less friction in roller- than in ball-bearings, as there need be no sliding action whatever in the former if well made. But in actual practice no bearing can be made in which there is no tendency of the rollers to run together; and if we place them in a frame to hold them apart we shall have about as much friction as when they rub against one another. ”

“ This consists of 3 iron rollers fixed in an iron frame. A, B, C, are the three cylinders, and a, b, c, d, the riband or sheet of metal passed through them to receive the cylindrical or conical curvature. The upper roller A can be raised or lowered at pleasure, in order to modify the diameter of the tube; and when one end of the roller is higher than the other, the conical curvature is given. The edges of the plated cylinders or cones are soldered with an alloy composed of silver and brass. An alloy of silver and copper is somewhat more fusible ”

“ Whilst in our first dejection, I thought I saw a place where a flat roller would remedy the whole misfortune; but a flat roller at Cape Spartivento, hard, easily unshipped, running freely! There was a grooved pulley used for the paying-out machinery with a spindle wheel, which might suit me. I filled him up with tarry spunyarn, nailed sheet copper round him, bent some parts in the fire; and we are paying-in without more trouble now. ”

“ A cord is applied round the groove in the middle part of the upper roller, and after passing over pulleys, as shown in the figure, it has a heavy weight hung at the one end, and a light weight at the other, to keep it constantly extended, while the heavy weight tends to turn the rollers with their endless cloth round in such a direction as to bring forward the rovings, without putting any strain upon them. ”