US 3704837 A
A mandrel has a conical chucking head on which chucking jaws are located, the conical head having a predetermined angle of inclination; the interior surfaces of the chucking jaws have three internally inclined, successive surfaces of inclination, the third and the first matching the angle of inclination of the chucking head whereas the middle one has a lesser inclination; the inner and the middle angles are joined by an offset, the chucking head having a matching shoulder. The outer surfaces of the jaws are cylindrical. Upon introduction of the arrangement into a hollow core, the inner surfaces of the core will tip the chucking jaws above the edge formed by the two dissimilar surfaces of inclination, releasing the inter-engagement shoulder and offset to permit centered location of the jaws while enabling tight fitting.
Description (OCR text may contain errors)
- United States Patent Heinz et al. 1 i
 CHUCKING ARRANGEMENT FOR HOLLOW CORES, PARTICULARLY FOR NEWSPRINT ROLLS AND THE LIKE  Inventors: Hubert Heinz, Lauben; Giinter Honsberg, Dietmannsried, both of Ger many  Assignee: Maschinenfabrik Augsburg-Numberg AG, Augsburg, Germany 22 Filed: July 19,1971
211 Appl.No.: 163,580
[30 Foreign Application Priority Data July 30, 1970 Germany ..G 70 28 636.1
 US. Cl ...242/68.2, 279/2  Int. Cl. ..B65h 17/12  Field of Search ..242/68.4, 68.2, 129.51, 72, 242/72.1; 279/2, 55; 82/44 1 Dec. 5, 1972 FOREIGN PATENTS OR APPLICATIONS 853,905 10/1952 Germany... ..242/68.2
Primary Examiner-Stanley N. Gilreath Assistant Examiner-Edward J. McCarthy Att0rneyRobert D. Flynn et al.
[5 7 ABSTRACT A mandrel has a conical chucking head on which chucking jawsare located, the conical head having a predetermined angle of inclination; the interior surfaces of the chucking jaws have three internally inclined, successive surfaces of inclination, the third and the first matching the angle of inclination of the chucking head whereas the middle one has a lesser inclination; the inner and the middle angles are joined by an offset, the chucking head having a matching shoulder. The outer surfaces of the jaws are cylindrical. Upon introduction of the arrangement into a ho]- low core, the inner surfaces of the core will tip the chucking jaws above the edge formed by the two dissimilar surfaces of inclination, releasing the inter-en-  References cued gagement shoulder and offset to permit centered loca- UNITED STATES PATENTS tion of the jaws while enabling tight fitting.
1,411,292 4/1922 Mueller .f. ..242/68.2 x 6 Claims, 2 Drawing Figures CHUCKING ARRANGEMENT FOR HOLLOW CORES, PARTICULARLY FOR NEWSPRINT 1 ROLLS AND THE LIKE I The present invention relates to a chucking arrangement or apparatus to mount hollow cores adapted to hold rolls of material thereon, and more particularly core sleeves for newsprint, paper, carton and the like, which may be of substantial weight, in the order of tons; for example, rolls of paper may weigh 1% tons, have a core length of about Im; the interior diameter of the core itself may be in the order of about to cm.
Various types of chucking arrangements for cores for rolls are known. Shafts are known which can be slid, usually in a fairly complicated manner, through the ho]- low cores and which are formed with elements which can spreadout from the shaft to hold the core on the shaft. Such shafts require operation by at least two persons when handling heavy rolls. It has been proposed to make core elements which consist of cones which are entered into the core opening from both sides. These cones have a tendency to damage the ends of the cores and, particularly at high torque, they do not provide for reliable transfer of rotational energy to the core unit itself.
Chucking arrangements have been proposed in which jaws are arranged which can spread, for example, by being swingably mounted on pivot points. Such arrangements have the disadvantage that when the core diameter varies from a set standard value the cylindrical outer surfaces of the jaws do not properly bear against the inner surface of the core itself. it has also been suggested to spread the jaws over conical surfaces in axial direction rather than swinging them over pivot points so that, upon spreading, they will self-adjust to the interior surface of the core sleeve. Movement of the jaws is usually obtained by means of a thread. Operating the thread requires an additional step in mounting the core after the chucking heads have been introduced into the core sleeve. The thread itself cannot be readjusted during movement of the roll, so that re-adjustment requires stopping of the roll and the apparatus with which it may cooperate. It may, however, be necessary to re-adjust the chucking arrangement, particularly if the core sleeve deforms under loading.
it has also been proposed to locate the jaws on a conical mandrel in which the jaws are spread apart as the mandrel is introduced into the core sleeve until cylindrical surfaces formed on the jaws fit against the inner surface of the core sleeve. it is, however, very difficult to introduce the chucking heads exactly in the center of the core and, from experience, only rarely will the chucking head and core be accurately axially aligned; thus, the jaws contact the inner surface of the core at different times and thus at different locations and will interconnect the conical mandrel and the inner surface of the core sleeve at different points. The outer surface of the jaws then will not be cylindrical and the core cannot be uniformly loaded or accurately axially mounted.
It is an object of the present invention to provide a chucking arrangement for core sleeves and particularly for core sleeves adapted to hold heavy loads which will accurately hold a core in centered position and which is easy to operate.
Subject Matter of the Present Invention Briefly, a mandrel is provided having a conical chucking head in which the cone has a predetermined angle of inclination. Chucking jaws are provided surrounding the cone of the chucking head and adapted to be spread apart upon axial shifting of the conical chucking head. The chucking jaws have a cylindrical outer surface which corresponds substantially to the nominal diameter of the interior opening of the core with which the chucking arrangement is to be used. A radially extending rim is provided thereon, adapted to engage the end surface of the core. The inner surfaces of the chucking jaws are formed with three axially sequentially arranged conical surfaces. The outer conical surfaces have an angle of inclination which matches that of the predetermined angle of the cone mandrel; the middle one, however, has a lesser inclination than the other two and at the junction between the middle one and the inner one of the surfaces an offset is formed, which matches against a corresponding shoulder formed in the mandrel. When the chucking arrangement is introduced in the core, the inner surface of the core will tip the jaws about the junction of the middle conical surface and the outer conical surface, thus releasing the offset from. the shoulder and engaging the conical surfaces of predetermined inclina tion on the jaws with the surfaces on the chucking head, the cylindrical outer surfaces of the jaws then contacting the inner surface of'the core sleeve. The arrangement preferably utilizes four jaws for each chucking head. The jaws are preferably pressed elastically against the mandrel at their ends, for example by springs, which may be circular springs located in grooves cut into the jaws. The surfaces engaging the core sleeves are preferably knurled, or these surfaces can have a lining of material thereon which provides a friction contact and prevents slipping between the core sleeve and the jaws.
In unloaded condition, the middle conical surfaces of the jaws match with the conical surfaces of the mandrel and the offset on the jaws engages the shoulder on the conical mandrel. Due to the lesser inclination of the middle jaw surface, the jaws will be folded together to form an essentially conical outer surface. This conical outer surface provides for ease of introduction of the collapsed chuckinghead without requiring exact centering thereof. If one of the jaws should contact the sleeve, it still cannot be shifted in location since the inner-engaging offset and shoulder will hold the jaw in position on the mandrel. When the chucking head has been introduced almost entirely into the core sleeve (or, which is saying the same thing, when the core sleeve has been slipped over the chucking head) so that the end surfaces of the core sleeve engage the radially extending rim, then the outer ends of the jaws will be pressed together, the offset will lift over the shoulder of the mandrel and the jaws will tip or tilt over the junction of the middle and outer conical surface. Upon further introduction of the chucking head into the core sleeve, the jaws are pressed slightly outwardly so that the inner surfaces of the jaws which have the same inclination as the inclination of the mandrel will engage the conical surfaces of the mandrel. The chucking heads are then pressed together to such an extent that the jaws will securely engage the inner surfaces of the sleeve, the edges at the end of the cylindrical outer surfaces of the jaws engaging the end surfaces of the core sleeve.
The chucking heads are preferably moved together by means of a pneumatic cylinder. The pressure on the cylinder is maintained during the winding, or reeling, process. If the core sleeve should deform, for example, due to excessive loading, then the chucking heads can be pressed more tightly against each other, thereby increasing the effective outer diameter of the chucking heads located about the conical mandrel. Automatic r e-adjustment of the position of the jaws is thus possible without stopping the winding or rolling operation.
The invention will be described by way of example with reference to the accompanying drawings, wherein:
FIG. 1 is a part sectional longitudinal view through a chucking head on a mandrel, before being placed on the load, or engaging a core sleeve; and
FIG. 2 is a view similar to FIG. 1 in which a chucking head is introduced into the core.
A mandrel l is secured to the end of a shaft, surrounded by four jaws 2 which are pulled to the position shown in FIG. 1 by means of springs 3, 4 located at the ends of the jaws. The mandrel l is formed with a conical surface 9, one for each of the jaws 2. The inside of the jaws is arranged with conical surfaces 5, 7 having an angle of inclination which matches the inclination of the conical surface 9 of mandrel 1, when the outer surfaces 14 (FIG. 2) of the jaws 2 are cylindrically engaging the inner surface of the core sleeve 16. The center portion of the inner surfaces of the jaws 2 is formed with a conical surface 6 having an inclination which is less than that of the surfaces and 7. An offset 8 (FIG. 2) is located between the central conical surface 6 and surface 7, the offset being matched by a shoulder formed on the mandrel. Offset and shoulder are in engaging relation when the chucking arrangement is loose, or removed, or not load bearing with respect to the core sleeve 16.
In unstressed, open condition (FIG. 1) the central conical surface 6 of jaw 2 engages conical surface 9 of the mandred l, and the offset 8 mandrel on the inner surface of the jaw 2 catches behind the shoulder 10 of the mandrel. Conical surface 7 can engage a surface 11 formed on the mandrel. Springs 3 and 4 are so dimensioned that, in unloaded condition, jaws 2 are contracted and that they will locate at the inner end of the mandrel to present a small diameter only to the opening formed by the core sleeve 16. The jaws cannot slip off the mandrel since the cylindrical surface 17 (FIG. 2) and the matching surface 12 as well as a projecting ring 13 formed on the mandrel limit the inward movement of jaws 2.
The outer surface 14, which is cylindrical, as well as the outer edge 15 on the jaws, is preferably knurled, or formed with a high friction lining or surface treatment.
Introduction of the chucking heads into the core sleeve is made simple since a small diameter only will be presented to the core sleeve. Even if one or more of the jaws would contact the inner surface of the core sleeve, the sleeves themselves cannot shift their location on the cone of the mandrel. The jaws 2 will tilt, or tip, only when the end surfaces of the core sleeve 16 engage the edges or rims 15 on the jaws, thus engaging surfaces 5 on the jaws with surfaces 9 on the mandrel. Tilting, or tipping, the jaws breaks the inter-engagement of offset 8 and shoulder 10 on the jaws and mandrel respectively, and as the chucking head is further introduced into the core sleeve, the jaws 2 will slide outwardly on the surface 9 of the cone 1. The jaws simultaneously press uniformly against the inner surface of core sleeve 16. When the chucking arrangement is stressed and completely introduced, then conical surface 5 as well as conical surface 7 of the jaws will engage the surface 9 of the mandrel 1.
The chucking arrangement in accordance with the present invention permits easy introduction of the chucks into the core sleeve and provides for uniform transfer of torque from a shaft on which the shaft is located to the core sleeve; it can be used without difficulties in core sleeves in which, due to loading, the core sleeve is out-of-round. Such core sleeves are usually made of spirally wrapped cardboard carton material. v
Axial pressure is best provided-by means of a pressure cylinder-piston arrangement P (FIG. 2), which is preferably pneumatic, but may be hydraulic. A thrust bearing T is interposed betweenthe pressure applying device to permit rotation to be imparted to the shaft on which the mandrel is located independently of axial thrust. The force supplied by the cylinder-piston arrangement and by the thrust bearing T is schematically indicated as arrow F in FIG. 2; the motion from the cylinder-piston arrangement can be mechanically or automatically controlled and is preferably reversible to provide for power advance and retraction, after the material from the roll wound on the core sleeve 16 has been removed.
Various changes and modifications may be made within the inventive concept.
We claim: 1. Chucking arrangement for cores (16) adapted to hold rolls of material thereon comprising a mandrel having a conical chucking head (9) formed with a pre-determined angle of inclination;
chucking jaws (2) surrounding the chucking head and adapted to be spread apart upon axial shifting of the conical chucking head; the chucking jaws (2) having a cylindrical outer surface (14) corresponding substantially to the nominal diameter of the inner opening of the core with which the chucking arrangement is to be used, and a radially extending rim (15 adapted to engage the end surface of the core (16);
the inner surfaces of the chucking jaws being formed with three axially sequentially arranged conical surfaces (5, 6, 7), the outer ones (5, 7) having an angle of inclination of said pre-determined angle and the middle one (6) having a lesser inclination than the other two; an offset (8) separating the middle one (6) of the conical surfaces from the innermost conical surface (7);
and a shoulder (10) corresponding to the offset (8) formed on the chucking head, the offset abutting the shoulder when the chucking head is unloaded and not engaging a core, and, upon entering the chucking arrangement into a core, the inner surface of the core tipping the jaws to release the offset (8) from the shoulder (10) and engage the surfaces (5, 7) of pre-detennined inclination on the jaws with the conical surface (9) on the chucking head having said pre-determined inclination to engage the cylindrical outer surfaces (14) of the jaws with the inner surface of the core (16).
2. Arrangement according to claim 1, including means (3, 4) releasably retaining the jaws in contact with the chucking head.
3. Arrangement according to claim 2, wherein the means (3, 4) retaining the jaws in contact with the