US 2851917 A
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United States Patent ANNULAR HINGED SPACER HAVING OFFSET HINGE PIN George F. Frew, Livonia, and Ronald D. Morton, Dearborn, Mich.
Application May 2, 1955, Serial No. 505,180
3 Claims. (Cl. 85-51) This invention relates to hinged spacers or washers, particularly to spacers which are adapted to be used on a shaft or arbor both ends of which are journalled in conventional supports, and in which the spacers can be re-' moved without disengaging the journal supports of the shaft.
A principal object of the present invention is to provide a new and improved type of hinged spacer or washer which can readily be added to or removed from a shaft or arbor without disengaging the journal supports of the shaft, and without removing other spacers or other devices mounted on the shaft or arbor such as the slitting knives of a rotary slitter.
Another object of the invention is to provide a new and improved type of hinged spacer in which no substantial gaps are left between mating surfaces of the hinge when the spacer is in use in the closed position, thereby preventing the entry of foreign matter into the hinge.
Still another object of the invention is to provide a new and improved type of hinged spacer, in which the male surfaces of the hinge move away from the corresponding female surfaces during opening of the spacer, thereby preventing abrasion of these surfaces by any foreign particles which may have become lodged on one of these surfaces.
The hinged washer or spacer described herein is especially adapted for use in rotary slitters for slitting sheets or coils of paper or of metals such as steel. Rotary slitters consist of a pair of rotatable shafts or arbors between which a sheet or coil to be slit is passed.v Each arbor has mounted on it a number of circular knives suitable for cutting the sheet or coil into the desired number of strips. The width of these strips is determined by the number and width of the annular spacers mounted on the arbors between the knives.
In preparing for a run, the knives and spacers used in a previous run are generally removed from one end of the arbors after the movable journal supports have been moved away from this end. Then the appropriate spacers and knives are slid over the end of the shaft one after the other in the order which is needed for the next run. The actual running time for a given set-up is frequently as little as or minutes, and the time re quired for setting up is often as high as /2 to 1 /2 hours. Even if only one or two spacers need to be changed for the next run, it is generally necessary to remove all or nearly all the spacers and knives when using the conventional type of annular spacers, since they can be mounted on the arbor only by sliding them over the end of the arbor. As a rule, four or five men who are used during the operation of the rotary slitter have nothing useful to do during the setting up period and, since this represents a very substantial part of the total cycle, it is clear that any substantial reduction in the time required for setting up would greatly reduce the labor cost involved in rotary slitting operations.
Our invention provides a very inexpensive and practical solution to this problem. By providing hinged 2,851,917 Patented Sept. 16, 1958 ice spacers which can be opened up a sufficient distance to permit them to be removed longitudinally from the arbor, it is possible to rearrange an entire set-up without moving away the journal supports from either end of the arbor, without removing or replacing any knives from the arbors, and only moving such spacers as are in the wrong place for the revised set-up. Very substantial amounts of time can be saved by the use of these hinged spacers.
Now, the general idea of using hinged washers for other uses (for example on bolts, so that the nuts will not have to be removed) is not new. However, when one attempts to adapt this general idea to a precision the hinged washers which are at present known, a substantial gap between mating surfaces is necessary in order to permit rotation of one part of the hinge with respect to another; if no substantial gap is left in these hinges, one section of the hinge will bind on the other before the hinge has been opened an appreciable distance. Such a gap is very disadvantageous in the slitting of metals, because metal chips may lodge in it and cause scoring and abrasion of the hinge when it is being opened or closed, thereby causing operating difiiculties and excessive maintenance problems, and resulting in a short life of the spacers.
In addition to the necessity of leaving a gap between mating surfaces in conventional hinged washers, another difficulty is that the amount of space between the two surfaces generally remains constant as one surface is rorotated past the other. As a result, any foreign particles which lodge between the surfaces have a tendency to be rubbed by one surface against the other, thereby aggravating the problems mentioned above.
Still another problem which we have found in the preparation of suitable hinged spaced for rotary slitters is that there is in certain cases a tendency for the moving section of the spacer or washer to move slightly inward toward the arbor during the opening operation. If this tendency is substantial, the spacer or washer will not open at all when it is mounted on an arbor, even though it may appear to work well when it is demonstrated off the arbor. Even if the aforesaid tendency is relatively small, this requires the use of spacers having a substantial gap between their inner edges and the arbor, in order to make the spacers operable. This is undesirable for a number of reasons, including the possibility of foreign particles entering this gap. 7
We believe that these difficulties explain why hinged spacers have not been successfully used on rotary slitters. We have now found a solution to these problems, which we believe makes it possible to provide thoroughly practicable and inexpensive hinged spacers for such uses as described above.
Other objects and advantages of our invention will appear more fully from the following description and Fig. 3 is a cross-sectional view of a hinged spacer, shown in open position after having been placed on the I arbor or before removal therefrom;
Fig. 4 is a top view of a hinged spacer, taken along the line 44 of Fig. 2;
Fig. Sis a top view of a hinged spacer, showing a modified form thereof;
Fig. 6 is a bottom view of a hinged spacer, taken along the line 6-6 of Fig. 2.
As shown in Fig. 1, a plurality of krii'ves 1'0 are mounted on two cooperating, parallel rotatable shafts 'or arbors "11 and 11a. The knives lflare prevented from rotating about thearbors by being keyed theretopand are prevented from moving along the arbors by means of sPfiqcrslZ. Thenumber and width of' spaoers iis 'selected in a predetermined-manner for 'anyparticular run, so as to produce the desired number and width of strips. Each spacer is also keyed to its respective arbor, in order toprevent-its rotation "about the arbor. The arrange-v ment of spacers and knives onthe two arbors is generally such that corresponding. pairs of" knives on one arbor are mounted'closer together than on the other arbor, so that the'duttin'g edgesare as-shown M13 in Fig. 1. In operation,"a sheet or'coil of metal or other material is fed continuously betweenthe two arbors 11, 11a, so as to be, out by the knives 10 into the desired number of strips which'are. then collected on reels. The structure shown in Fig. 1 iskonventional, except insofar as we modificdathe type of spacers 12 employed.
Ou'r hinged spacer-12 is, shown in cross-section in Fig. 2g-in the closcdiposition, and in Fig. 3 in the open posi-- tion, ineachca'se being mounted, on an arbor 11. Each spacer 12; contains a keyway 14-Which is adapted to receive the part of the-key15"projecting from the arbor 11, thereby; permitting thespacer 12 to be mounted substantially in contact with the arbor at all pointsal'ongtheinner edge 16 ofsaid spacer 12, and' preventing rotation of"said* spacer '12 about said arbor ll. Each spacer 12 consistsof-two sections 17', 18 which'are hinged together at one e'nd'and free to open or to be locked together at the-other-end as desired. One section (section 17in the embodiment shown) contains a recess 19 in which-alatch 20 m'ounted on the other section (section 18 in the embodiment-shown) may be engaged -'so as to lock the two-sections together when sodesired. Fig. 2 showsthelatch'20 inlbcking-p'osition within recess 19-, and Fig; 3 shows-the-latch 20 removedfrom said recess 19, in open positions It is not-important which section contains the recess-and which the latch, the embodiment Jhown in the drawings arbitrarilyshowing the recess in section 17 andthe" latch on section 18. The latch"'20 may be ofiany-suitable-des'ign, but is preferably -of'such structure-that itissubstantiallyflush with the outer edge 2-1-of the- 'spac'er l2- at all'points other than the'por-tion 22 which fi-ts within the recess-19, and it preferably-"contains arelatively;fiat-portion '23 which fits withinthefl'at portion 24 of--"s'aid *rece'ss19; For ease-ofopening said latch 20, it is preferred that the flat port-ion 23 of-said latch '20 not reach to the'-'endof the flat-portion 24 of said; recess 119, so that'a tool such as a screw-driver can be forcedunder'the end of latch '20 in order to spring it open. The'latch; 20 is preferably made'of a metal exhibiting suitable 'spring characteristics, and" is preferably mounted in a shallow groove 25 in its section (section 18 in the embodimentshown'); by means of a; plurality of countersunk screws- 2 6; v I
The hinged end 'of-e'ach' section '17; 18 comprises atleast one male portion 27 and at least one female portion 28. In Fig. 4, the embodiment'sho'wn 'contains'one male-and one female portion in e'ach-section If, 18; in Fig.5; a modified'embodiment is shown-in which-oneness tion 17 contains one male and two female portions,-'while thefother section 18: contains; two male. and one female portions. In the-ease of wide; spacers L2, it: is; preferable. to use hinges of the tyne shown in Fig. 5 rather than'that shownin Fig; 4, or; if desired, sectionscontaining even ore maleand fem le 'P E OHS. than hown. in Fig. 5.. Each of said male and femaleportipns 27, 28 iscutalong substantially he-sam arcuate surface. efined by an. ar 29 whose radius exceeds half the distanceiSO, between g'the;
4 V inner edge 16 and the outer edge 21 of the spacer 12, which are 29 is substantially tangent to the inner edge 16 of said spacer 12, and-Which are 29 terminates at points 31, 32 at the outer edge 21 of the spacer 12. By employing substantially the same arc to define both the male and female portions of the hinged ends, no substantial gap is left between the corresponding male and female arcuate surfaces of the opposing sections when the spaces 12 is in closed position. This makes it possible to prevent the entry of foreign particles such as metal unsatisfactory in practice.
chips between these surfaces, which would tend to, cause scoring and abrasion of the hinge. Now, if no substantial gap is left between corresponding male and female surfaces, it will be found thatno substantial amount of opening of the spacer 12 is possible unless the radius of said arc 29 substantially exceeds half the distance 30. For, if this were not the case, points 31 and 32 would approach each other, and virtually as soon as one section 17 were rotated, its upper edge 21 would bear against the-upper edge'- 21 of the other section 18 thereby preventing furtherrotation. On the other hand, as shown in Figs. 2 and 3, ifthe radius of said are 29 exceeds half the distance 30 by a small but substantial amount, a very substantial distance is left between points 31 and 32, so that section 17 can be rotated at least far enough to permit removal-of the spacer 12 from the arbor 11 simply by lifting said spacer 12 in the open position oil said arbor 11, as is about to be done in Fig. 3. As an example,; in an actual working model of our hinged spacer. said'spacer being approximately 5 inches in inside diam-- eter and 7 inches in outside diameter,'a satisfactory radius of arc-'29'was found to be which is only Ms in excess of half the distance between the inner edge 16 and the'outer edge 21. Thearc 29 is made tangent to the inner edge 16'of the spacer 12' because if said arc were to extend toward a position substantially lower than this,- it'wouldnot be possible to-op'en the hinge substantially because of-binding of the'hi'nged ends against the arbor 11 during attempted rotation.
' While itis possible to place the hinge pin 33 linking the two sections together in the obvious place, namely at'thc center 34 of the are 29, we have found this to be very If this is done, the amount ofspace between the corresponding male and female surfaces of opposing sections 17, 18 of the spacer 12 willrernain substantially constant during rotation of the hinge, But since the amount of this gap between surfaces has purposely been made very small, this would mean that any foreign particles accidentally caught betweenysaid'surfaces would greatly impede rotation of the hinge and would cause excessive abrasion and wear of said surfaces. The amount of space between the rotating male portion and the arbor 11 would also remain constant during rotation, leading to similar 'difiiculties. Therefore, in the preferred embodiment ofour invention, as shown in the accompanying drawings, we have placed the center of'said'hinge pin 33 approximately along a line extending from the, center 34 of. said are 29 toward the point 31. We have found that if the hinge pin- 33' is moved from the center 34j'of'said are 29 approximately along this line ashort distance, the male portion 27 of section 17'upon' rotation will become separated substantially from the co l'respondingjfemale portion 28 'ofsection 18 and, fur
thermore, section 17 will be,1ifted' substantially off the arbor 11'. his not necessary or desirable to move'the extent, this; would cause the outer edge 21' of section 17' to bind. against the outer edge 21' of'section 18' at too early a point in the rotation of section 17, thereby decreasing unnecessarily-the amount of opening possible. Once. these, factors are recognized, there is no. difiiculty in finding a suitable position for the hinge pin 33. In general, this position will be much closer to point 34 than to point 31 and, while it is preferable that the position of the hinge pin be approximately along the aforesaid line between points 34 and 31, it is by no means necessary that said position be exactly or nearly exactly along said line. Generally speaking, it will be found better to select a point on or above said line (that is, closer to the upper edge 21) than a point below said line, insofar as amount and ease of opening are concerned. The exact position is not critical, providing the factors discussed above are taken in account. As an example, in an actual working model, a satisfactory position for the hinge pin 33 was found to be approximately /s to the right and 14; toward the outer edge 21 from the center 34 of are 29. Such a location may, for the purposes of this discussion, be regarded as approximately on the line between points 34 and 31.
It should be noted that when said hinge pin 33 is cated as described above; only section 17 is rotatable away from the arbor 11; section 18 cannot be rotated under these circumstances, as it would bind on the arbor 11. However, this is no disadvantage, since it is not necessary that both sections be rotatable, so long as one or the other section is rotatable. For convenience, it is preferred that the non-rotatable section be the one which contains the keyway 14, as shown in the drawings. The mode of operation in this case is clear from Figs. 2 and 3. After unlocking the latch 20, section 17 is lifted up enough to permit the spacer 12 to be withdrawn from the arbor 11. When it is desired to replace the spacer 12 on the shaft 11, section 18 is first placed on the arbor 11, the key 15 fitting within the keyway 14; then section 17 is rotated down to closed position and the latch 20 is closed.
It should be further noted that suflicient clearance must be provided between the facing surfaces of the male and female portions, at least on those portions between the point of tangency of the facing surfaces with the inner surface of the spacer and the lines on said facing surfaces (toward point 32) intersected by the plane including the center of radius and the hinge axis, to prevent locking of the hinge point.
The hinge pin 33 should be entirely contained within countersunk openings 35 extending through sections 17 and 18, so that no part thereof protrudes beyond either end of the spacer 12.
Various modifications in the details of construction may be made without departing from the spirit of the invention as defined in the following claims which are directed to the principal features of the invention rather than to the readily changeable details of construction.
1. A substantially annular hinged spacer comprising two sections hinged together at one end, means for fastening together and unfastening the free ends of said sections, each of said hinged ends comprising at least one male and one female portion cut substantially along an arcuate surface the radius of which exceeds half the distance between the inner and outer edges of said spacer, said arcuate surface being substantially tangent to the inner edge of said spacer and terminating at the outer edge of said spacer, the arcuate surface of the male ends of one section being substantially in contact with the arcuate surface of the corresponding female ends of the other section, the aforesaid hinged ends being held together by a hinge pin about which they are free to rotate when the free ends of said sections are unfastened, the amount by which the radius of the said arcuate surface exceeds half the distance between the inner and outer edges of said spacer being sufficient to permit rotating one section of the spacer away from the other a distance in excess of the diameter of the inside edge of said spacer, said hinge pin being offset from the center of the arc defining the aforesaid arcuate surface approximately along a line extending from the center of said are toward the point of termination of said are at the outer edge of one of the sections of said spacer, the amount of said offset being sufiicient to cause the male and female ends to become substantially separated during the opening of the spacer but being sufficiently small to avoid decreasing significantly the extent to which the spacer can be opened.
2. A substantially annular hinged spacer comprising two sections hinged together at one end, means for fastening together and unfastening the free ends of said sections, one of said sections containing a keyway in its inner edge running the width of said spacer, each of said hinged ends comprising at least one male and one female portion cut substantially along an arcuate surface the radius of which exceeds half the distance between the inner and outer edges of said spacer, said arcuate surface being substantially tangent to the inner edge of said spacer and terminating at the outer edge of said spacer, the arcuate surface of the male ends of one section being substantially in contact with the arcuate surface of the corresponding female ends of the other section, the aforesaid hinged ends being held together by a hinge pin about which they are free to rotate when the free ends of said sections are unfastened, the amount by which the radius of the said arcuate surface exceeds half the distance between the inner and outer edges of said spacer being sulficient to permit rotating one section of the spacer away from the other a distance in excess of the diameter of the inside edge of said spacer, said hinge pin being ofiset from the center of the arc defining the aforesaid arcuate surface approximately along a line extending from the center of said arc toward the point of termination of said are at the outer edge of the section of the spacer which con- References Cited in the file of this patent UNITED STATES PATENTS 838,976 George Dec. 18, 1906 948,600 Vannoy Feb. 8, 1910 1,221,023 Cameron Apr. 3, 1917 1,418,052 Barton May 30, 1922 1,596,571 Barton Aug. 17, 1926 1,597,525 Knake Aug. 24, 1926 2,088,527 Ma July 27, 1937 2,613,571 Herman Oct. 14, 1952