US1741974A - Suction-roll shell drilling - Google Patents

Description

Dec. 31, 1929.

H. C. BURDEN SUCTION ROLL SHELL DRILLING Filed Nov. 23, 1928 o 0 0 0 02 0 0 0 o O 0 r 6% (I 3 1 I v G (D :1:

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The present invention relates to paper making machinery and more particularly to the disposition or distribution of the drilling or perforations of the shell for the suction roll.

The suction rolls in general use in machines of this type are perforated throughout their operativesurface with a great number of small diameter closely placed and radially 19 disposed holes. Wherever the metal of the shell is thus out or drilled through-it is weakened to just that extent. In the larger machines these large cylindrical shells, when 'used for couch rolls, measure as much as 30" to 36 diameter by 25 length. Such shell is supported only at its extreme ends. \Vhen used as a press roll of corresponding proportions it is also supported at its extreme ends but must, in addition, sustain 20 the weight of. the cooperating top press roll. In practice, the drilling of these large shells is made by amultiple spindle machine, a great number of drills all acting at one time to produce a corresponding number of perforations. To provide-a uniform spacingbetween the drill holes and a uniform .distribu-' tion throughout the'surface of the shell, an

indexing plate is provided.

As is well known, these shells comprise the revolving or movable member of the suction roll assembly, the stationary member being the suction box supported in well known manner therewithin. The box, as is well known, in assembling, is so adjusted relatively to the enclosing shell as to maintain a light run- .ning contact between the box acking and inner shell surface or wall. 11 the modern paper making machine, the shell surface travels. at .a high, speed, often' as high as 1000 ft. per minute or more. In the paper stock there is more or less foreign matter of a gritty or abrasive nature which asses through the perforations of the shel A certain portion of this, invariably follows the inner wall of the shell and is picked up or engaged by the box packing. The packing, itself, in its light rubbing contact with the shell wall has a slight abrading action, even under the most favorable circumstances. The continual addition of the foreign matter multiplies this grinding action. This scores the inner wall of the shell into alternate circumferential ridges and grooves so that many shells,after a few years-use must be rebored. Obviously, this reboring can not be carried beyond certain safety limits. The shell wall thickness can not be reduced beyond that essential to withstand thestrains imposed by the work- 1 ing conditions to be met in operating the machine. 1

The main purposes of the resent invention are to overcome these an other serious objections, and, at the same time, provide a drilling or perforation which may be easil and quickly applied to a suction roll shell.

.In order to more clearly disclose the construction, operation, and use of the invention reference should be had to the accompanying drawings forming part of the present application. Throughout the several figures of the drawings like reference characters designate the same parts in the various views.

In the drawmgs Fig. 1 is a fragmentary side elevation of a, suction couch roll with the invention applied;

Fig. 2 is a top plan view of the same roll, showing the invention in diagram, the invisible perforations being shown in. dotted line, and only two rows;

Fig. 3 is a vertical cross section in a plane at right angles to the longitudinal axis of the roll ,on line 3-3 of Fig. 1'; and

Fig. 4 is a plan view of the fragment of Fig. 1 split longitudinally on line LT-4: of Fig. 2, and flattened to develop the lines of the drilling.

It will be obvious to those skilled in the art that drawings of a roll of the size used, when reduced to such size as is required for a patent application, can not be kept in exact pro ortion as to such matters as the erforations or the relative positions of the lines of perforations, etc. These features are, necessarily, considerably enlarged or exaggerated in order to more clearly and definitely bring out the ideas of the invention. For instance, the diameter of drill holein a couch shell is about of an inch end, in one known type of drilling, the distance between centers of rforations in the same row, circumferentielly of the roll is 1.0162 inches and longitudinell .5666 inches. For a shell 30 inches in 'ameter by 25 feet lon a propor- 5 tionete reduction would nearly minate the perforations and run the lines so close as to confuse. The shell illustrated is for'a suctionprea roll. For couch roll drilling the rations are of greater diameter than for m pres roll drillin end have their outer ends counter sunk. "kewise, there is a difference between the drilling for'first and second preee rolls, all as be well understood mma shell h.- been drilled the inner 1 well which, in operation, travels at hi h speed across the contacting surface of t e packing strips of the suction box presents many thousands of small diameter round ltilplee each surrounfiled b a metal ed is;

eeeedgescrosst epa 'gstripst eya .0 to plane themdown. Consequently, where planed in this manner, the packing and grit or other foreign matter, has little or no portunity to wear the inner surface of t e shell. On the other hand, where it is not so planed, the shell is worn away, leaving grooves with intervening ridges. In other words, this planing action keeps the planed portion of the acking from wearing the shell surface. eretofore, the erforations have been so distributed that t y do not p lhane, ually, all parts of the packing strips.

e res t in principle, is the same as though the phacking strips were not planed at allthe ell is badly scored.

For simplicity and clearness of illustratlon,

I the shell only has been shown with its perforations, apart and removed from the assembled organizations in which it, necessarily, must alwa in and cooperation with the particular parts of the machine when used, variously, as a couch, press transfer, or other suction roll need no further elaboration here and will all be readily understood by those skilled in the art. Likewise it is my understanding that all such assemblies and combinations fall within the scope of this invention when they comprise a shell having the type of drilling or rforation herein disclosed.

y the resent construction, arrangement and disposi tion of the perforations, the planing action is uniform throughout the entire surface of the packing strips so that there are no sections capable of exciting a greater grinding or abrading action than any other section. Consequently, the inner shell surface is evenly worn and does not need reboring at any time.

Referring to the drawings in detail, 1 indicates the shell. It is rforated throughout its operative surface with the particular type of perforation best adapted to the purpose of its u'sesuch as couch, ress, transfer, etc. 66 Accordingto the present lnvention these perbe used. Its relative positionforations are disposed on a lurality of endless parallel curved lines eac makin a single complete circumferential traverse o the shell and the several lines bein closely spaced a art longitudinally of the s ell. Preferably t ese lines alternate, the perforations of the intermediate ones bein spaced slightly circumferentially relativefy to those 0 the lines immediately adjoining on either side.

Each circumferential line comprises-a compound of two opposite curves of the same total length and inclination or pitch. In the particular exam le selected for the purpose of illustrating t e present invention t ese curves of each such compound are half-helixes or helicoidal for one-half of a single circumference. Since the two half-helixes are 0 positely directed or inclined and are of t e same pitch or an actly align, making one continuous curve, one half being directed and inclined oppositely and equally to the other. Each such circumferential line is complete in itself and spaced from those adjacent. No two or more mer e or connect one with another. Or, brie y, the two halves of each such endless row may each be considered as one half of a sin le com lete circumferential turn or rotation whic 1 forms a single helix of a finel pitched screw thread which, if uninterrupte would run from end to end of the shell, each such half bein in continuation of the other and being inc ined and directed oppositely thereto, so that the two ends of the two halves align to produce a single continuous circumferential doubly and reversely curved row. It will also be obvious that in reversing one half of each helix relatively to the other, the screw thread is brokenor interrupted at each helix and converted into a corresponding number of separate, parallel, spaced, endless, doubly and reversely curved, continuous, circumferential rows each running once completely around the shell. While the curve above described has been set forth as consisting of two parts of equal length it is to be understood that other fractions of the total helix may be used, provided such fractions combine to reduce a single, continuous circumferential row extending once completely about the shell and havin one or more portions inclined and directed o positely to one or more other portions thereof For instance, the successive helixes may be each divided into four, six, eight, twelve and so on equal parts, the alternate parts being oppositely disposed. The resulting circumferential rows would have a wave-like, sinuous, or convolute outline, but each complete such row would be parallel with and to all the others.

It will be obvious that in passing across any one given point of the packing strip of the suction box which forms a part of all such rolls, the perforations of one half of any such arity their ends will ex-' 1 circumferential line will act oppositely thereon to the action-of the other half of the perforations in such line. Thus, whereas, the

' erforations in the first half bein distributed helicoidally' from-the direction 0 one end toward the direction of the other end will have a tendency to feed the packing in the direction of their incline, the perforations of the other half, being distributed oppositely, will act e ually in the opposite direction. Thus, each alf of each revolution of the shell will have its longitudinal feeding tendency exactly offset or counteracted by that of the other half and there will be no resultant longitudinal feeding action in either direction. Of course, this applies equally to all cases where the circumferential rows are made up of an equal number of equally oppositely inclined and directed curvatures whether such parts constitute halves, quarters, eighths or other arts bf one entire row.

In t e present instance, though merely for illustrative purposes, the form arbitrarily selected is that of the two-part circumferential row, or, in other words, a single endless circumferential row consisting of two parts of equal length, each part being equally but oppositely inclined or directed relatively to the other such half, the two thereby aligning or -merging to form one smooth continuous uninterrupted circumferential row.

In order to somewhat more thoroughly distribute the perforations throughout the entire operative shell wall and thereby completely eliminate any unplaned packing strip surface, a second series of rows may be disposed intermediate of and alternating With those of the first. Such second series will be slightly spaced circsumferentially relatively to the such group may be given the same relative circumferential position as that of the first row of such group. The grouping shown in the drawings is the simplest and most readily illustrated and described within the field of the invention. In the case illustrated a cross section at right angles to the'longitudinal axis of the shell and therefore. "when assembled, to the packing strips of the suction box, has been arbitrarily taken and is shown in Fig. 3. Thisris the path of theperforations crossing as that point of the packing. There would be as first series so that the holesofeach correspond-- tion. It will ,be seen that at the opposite i diameter of the shell it passes the same way through a corresponding perforation of the other and opposite half-helix. Reading Fig.

3 ma clockwise direction, the section from the point- Where it passes diametrically through the perforation of row 2 outs only slightly through the right hand side of the next perforation of that row, misses entirely the next, then cuts very slightly the third from the last perforation of the next row to the right of row 2 which I will refer to as row 3. The two half helices of row 3 are designated 3 and 3 the half 3 bein the last half or, as read on Fig. 3, the first half intersected by. the section line. Continuing, the section line will cut, successively, more deeply through the perforations of the part 3 until it reaches a point about one-quarter around the shell, where it will pass about diametrically through a perforation. From this point the cut Will decrease in thesame manner in which it previously increased until it reaches a point where it again passes intothe erforations of row 2 at a point diametrical y opposite, in the shell, to where it started in row 2. Following the section in the same direction, in the .lower half of Fig. 3, beginning with the diametrical cut of the perforation in row 2, the next will be out much less deeply, the following one will be skipped, and the cut will then intersect the third from the middle perforation of the next row on the left, or row 1, the two halves of which are indicated as 1 and 1 reading Fig. 3 inacl'ockwise direction.

It will be noticed that the cut through the perforations of row 1 is,- in cross section, the same as that through row 3. However, it is the reverse half of the helix with the curve in clined reversely. The cut through the perforations deepens from the right side of the row, relatively to row 2, to the full diameter cut at the bottom of Fig. 3 and then decreases until it passes out of row 3, skips a perforation in row 2 and then cuts slightly the left of the row 2 erforation preceding the first one with a full diameter cut.

The path of the cut and therefore the successive perforations crossing any point on the packing strip is clearly shown on Fig. 4.

Rows 1 and 3 are second series rows or rows of a series somewhat circumferentially offset'relatively to row 2.

It will be noticed that, the first perforation to act on the packing is that "of row 2, the next is also row '2 but only a small part of that one acts on the same spot or, the next lift ' ference.

one acts onl on a art ofthat spot. The next is in the a alf 0 row 3. This point to the quarter circle or 90 point there is a steady increase until full diameter is again reached, which means that the area acted upon steadily increases and in the same direction until the original area acted upon is reached. It then decreases back to the starting point, as to size, of row 3', and then the full size again of row 2. Thus whatever tendency there ma be, by rotation of the shell across the pac ing, to feed either shell or packin longitudinally relatively to the other, is 0 set or counteracted, the tendency in one uarter circumference being just matched in the reverse by that of the next succeeding quarter circum- Thus all tendency toward relative longitudinal movement as between shell and packing is completely eliminated and, at the same time every art of the packing surface is equally and t oroughly acted upon and planed by the perforation edges.

Having thus described my'invention, what I claim and desire to protect by Letters Patcut is 1. A suction roll shell for paper making machines provided with a plurality of" endless lines of perforations each comprising several curves.

2; A suction roll shell for paper making machines provided with a plurality of endless lines of perforations each comprising several merged curves.

3. A suction roll shell for paper'making machines provided with a plurality of endless lines of perforations each comprising oppositely directed curves.

4. A suction roll shell for paper making machines provided with a plurality of endless lines of perforations each comprising equally and oppositely directed curves.

5. A suction roll shell for paper making machines provided with a plurality of parallel closely spaced endless lines of perforations each comprising oppositely directed curves.

6. A suction roll shell for paper making machines provided with a plurality of circumferental parallel closely spaced endless lines of perforations each comprising oppositely directed curves.

7. A suction roll shell for paper making .machines provided with a plurality of endless lines of perforations disposed in several series, said lines being arranged parallel and closely spaced and each. such line comprising several curves.

8. A suction roll shell for paper making machines provided with a plurality of endless lines of perforations, each such line comprisin oppositely and equally inclined parthe ices. 4

9. A suction roll shell for paper making machines provided with a plurality of endless lines of perforations each such line compris-' ing several curves and said lines being so disposed on said shell that the perforations of several will he intersected by a single lane passed through said shell at right ang as to the longitudinal axis thereof.

10; A suction roll shell for aper making machines provided with a plura ity of endless lines of perforations each such line comprising several curves and said lines bein so disposed on said shell that the perforations of several will be intersected by a single lane passed through said shell at'right ang esto the lon itudinal axis thereof, the curves formed y such intersections being equally, oppositely inclined in diametrically opposite parts of the cross section of the shell so made.

Signed at Sandusky, Ohio, this 17th day of November, 1928.

HARRY C BURDEN.

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