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0 OLLAFSI BLE MANDREL INVENTOR. 'BM. 0 a m iron (0J6, 821M, M M M HIS ATTORNEYS United States Patent 3,273,817 COLLAPSIBLE MANDREL Pierre M. Damiron, Paris, France, assignor to Wean-Damiron S.A., Paris, France Filed June 22, 1964, Ser. No. 376,873 Claims priority, application France, July 2, 1963, 940,052 7 Claims. (Cl. 242-72) This invention relates to improvements in the handling of metal coils and relates in particular to new and novel mandrels such as are employed to hold coils of strip metal. The mandrels of the present invention are particularly useful in holding strip steel coils while they are being wound or unwound during continuous treatment of the strip such as tinning, shearing,'rolling, etc.

The mandrels that are used in continuous strip processing are usually expandable so that they may be inserted into the circular central space of a coil and their outside diameter expanded to grip or lock into the coil. The conventional mandrel is constructed of segments which can be extended radially outwardly by a sliding movement within the mandrel.

Conventional expandable mandrels are wholly or partially mechanically constructed. Such mechanical devices are extremely complex, for example, many operate on the principle of a crankshaft or on movable rods that are perpendicularly positioned in respect to the axis of the mandrel. The manufacture of the requisite numerous parts that are incorporated into such mechanical devices is both complicated and costly. Th present invention is an expandable mandrel which is very simple in construction and which operates on the principle of fluid pressure, preferably hydraulic, expanding flexible chambers. For this purpose, liquid-tight inflatable chambers one each corresponding to an expandable segment are positioned between the central shaft of a mandrel and the expandable segments each of which are disposed to slide radially outwardly.

The present specification includes embodiments wherein the inflatable chambers are positioned to extend (1) parallel to the central shaft and (2) annular to the central shaft.

Preferred embodiments of my invention are shown by the accompanying drawings, in which:

FIGURE 1 is a side sectional view of an expandable mandrel having longitudinally expanded segments;

FIGURE 2 is a sectional view of the mandrel of FIG- URE 1 taken along the line 11-11 of FIGURE 1;

FIGURE 3 is a sectional view similar to FIGURE 2, with the mandrel in the retracted position;

FIGURE 4 is an illustrated schematic diagram showing a means for subjecting the expandable chambers to simultaneously corresponding fluid pressure;

FIGURE 5 is a side sectional view of a second embodiment of the present invention showing an expandable mandrel having annularly disposed inflatable chambers;

FIGURE 6 is a sectional View taken along the line VI-VI of FIGURE 5;

FIGURE 7 is a fragmentary sectional view of a modified version of the embodiment of FIGURES 1-3, the section corresponding to that shown by FIGURE 3; and

FIGURE 8 is a fragmentary longitudinal view of a section of a mandrel constituting the embodiment shown by FIGURE 7.

As shown by FIGURES 1, 2 and 3, the expandable mandrel of the present invention comprises a central shaft 10 having multiple spaced longitudinal recesses or grooves 11 positioned around its circumference. One each of a plurality of members 12, having an elongated stem portion 22 and an arcuate outer portion, is positioned so that the stem 22 slides within a recess 11. In the embodiment shown, shaft 10 has four U-shaped recesses or grooves 11 whose parallel opposing edges are covered by sheets or bushings 14 which act as guides for sliding members 12. Elongated stems 22 of members 12 each has a longitudinal chamber 23 in the form of a U-shaped slot centrally positioned therein. Chamber 23 receives an inflatable (or dilatable) member 13.

The edges 15 of the arcuate portion of each adjacent member 12 terminate in teeth 16 which mesh with one another when the members 12 are retracted forming a continuous cylindrical surface.

The bottom surfaces of edges 15 of each member 12 abut against flat portions 17 of the central shaft 10 in their retracted position (FIGURE 3). Flat portions 17 are located between the recesses 11.

Inflatable members 13 are made of elastic, water-tight envelopes 18 into which a fluid (preferably hydraulic) may be introduced.

Each member 12 terminates Within annular recesses 42 of sleeve shaped end members 40 and 43. Bushings 40' and 43' provides a sliding surface for the ends of members 12 and shoulders 41 formed by annular recesses 42 limit outward movement of the segments. Shaft 10 is provided with stepped down reduced diameters at 10 and 10" for attachment means.

The illustrative schematic diagram of FIGURE 4 illustrates one hydraulic installation for subjecting inflatable members 13 to fluid pressure. The installation comprises chiefly a master compressor consisting of a cylinder 39 and its position 30 which by means of a yoke 30:: mechanically controls the pressurization of auxiliary compressors which consist of pistons 31 and their cylinders 32 in such a way as to guarantee uniform pressure in the various in flatable members 13 and synchronized movement of the segments. Inflatable members 13 communicate with cylinders 32 through hoses 33 and each auxiliary compressor along with its corresponding hose and inflatable member forms an independent system having the same volume as every other system to insure uniform pressure in each system.

Hoses 33 extend through the central shaft 10' to inflatable members 13 and are attached to envelope 18 by conventional attachment means 34 (see FIGURE 1).

In the operation of the embodiment of FIGURES 1-4, hydraulic fluid is introduced into cylinder 39 under pressure to displace piston 30 to simultaneously displace pistons 31. Displacement of pistons 31 simultaneously forces fluid from cylinders 32 into each of the inflatable members 13 within chambers 23 through intermediate hoses 33 at a constant rate. This results in a simultaneous substantially identical displacement of each of the segments 12 outwardly into contact with the center portion of a coil of strip steel (see FIGURE 2).

FIGURES 5 and 6 show a second embodiment of the present invention. This embodiment is an expandable mandrel having annular expandable chambers 44 spaced at regular intervals along a central shaft 45. In this case, members 12 (of the embodiment of FIGURES 1-3) are replaced by ring members 46 of elastic material each of which is formed with an annular U-shaped slot which encompasses an expandable chamber 44. Expandable chambers 44 are made of elastic, water-tight envelopes 48 into which a hydraulic fluid may be introduced under pressure to cause envelopes 48 to expand. Ring members 46 expand spacewise simultaneously with the expansion of chambers 44. Consecutive members 4 6 are separated by annular plates 47. Ring members 46 and annular plates or spacers 47 are retained on central shaft 45 by means of a collar 45a and an end plate 45b which is bolted to the end of shaft 45 to restrain end plate or spacer 47a.

The hydraulic pressurizing installation of FIGURE 4 can also be applied to supply fluid pressure to the chambers 44 of the embodiment of FIGURES 5 and 6. In this eventuality, when the master cylinder 39 is activated to displace piston 30 and thus pistons 31 of cylinder 32, hoses 33 will carry hydraulic fluid under pressure to the various chambers 44. Thus, ring members 46 are caused to expand into the interior of the coil and grip the mandrel within the coil.

The apparatus of FIGURES 7 and 8 constitutes a modified version of the embodiment of FIGURES 1-3. FIG- URE 7 shows a central shaft 50 to consist of a welded assembly of a-tubular shaped elongated member 51, radial-1y extending pairs of elongated plates 52 and tangently positioned elongated base plates 53. Plates 52 and 53 define three U-shaped recesses or grooves 54 which are lined with bushings 55 and receive the stems 56 of each adjacent member 57 (only one of which is shown).

Members 57 each consist of an arcuate outer portion 58 joined along its inner concave surface by the extending elongated stem 56 and arcuate end members 83.

Stem 56 consists of extending elongated legs 59 each formed with a shoulder 60 disposed to contact the upper edge of bushings 55 and limit the depth to which stem 56 will extend or slide into the recess 54. A plate 61 attached to the extended ends of legs 59 constitutes a portion of stem 56. An elongated U-shaped slot 62 in the extended end of each plate 61 forms the chambers 63. Two elongated inflatable members consisting of an inner continuous, fluid-tight envelope 64 and an outer protective envelope 65 are positioned within each chamber 63. Envelopes 64 and 65 are constructed of rubber or other inflatable material.

In operation, fluid pressure provided to the interior of the continuous envelope 64 by means such as that illustrated by FIGURE 4 causes the envelope 64 and protective envelope 65 to inflate and force member 57 to extend outwardly.

Opening 66 within washers 67 receives bolts 68. Threaded portions 69 of bolts 68 threadably engage threaded openings within flanges 70 of plates 52. Bolts 68 are prevented from sliding through openings 66 of washers 67 by means of tapered heads 71 which are held to bolts 68 by threaded screws 72 which are threadably engaged with a threaded recession (not shown) axially positioned in the end of bolts 68. Bolts 68 slidably extend through openings 73 of flanges 75 which extend perpendicularly from mounting plates 76. Mounting plates 76 are attached to and extend from the concave surface of the arcuate outer portion 58 of member 57. Springs 76a are positioned around each bolt 68 and bear on flanges 75 and washers 67 so that when inflatable envelope 64 is inflated to cause member 57 to extend radially outwardly from central shaft 50 such movement will be opposed by springs 76a. When pressure is released wlthln envelope 64, springs 76a will cause the members to be retracted so that the mandrel may be disengaged from the inside of a surface of a coil.

The mandrel of FIGURES 7 and 8 is provided with end assemblies consisting of members 77 disposed about tubular member 51, plates 7 8 extending perpendicularly from plates 53 and connecting rims 79 attached to plates 78 by bolts 80. Rims 79 extend over plates 78 and bushings 71a to engage the shoulders 82 of end members 83 when segments 57 are extended radially outwardly. Thus, the extent to which the segments 57 may be extended 1s limited by the distance between rims 79 and shoulders 82 of end members 83.

While I have described the present preferred embodiment of my invention, it is to be understood that it may be otherwise embodied within the scope of the following claims.

I claim:

1. An expandable mandrel comprising an elongated central shaft formed with a plurality of longitudinal recesses radially spaced around the periphery thereof; an

elongated member disposed to slide within each of said recesses toward and away from the axis of said shaft; a liquid tight inflatable envelope located in each of said recesses between the bottom of said recess and the member, the volume of said envelopes being equal; an auxiliary hydraulic compressor operatively connected to each of said envelopes to supply pressurized liquid to said envelope for inflation thereof; and an actuating means for simultaneously actuating each of said auxiliary compressors to simultaneously supply fluid to each of said envelopes.

2. An expandable mandrel as set forth in claim 1 wherein said actuating means comprises a master compressor and a yoke, said yoke interconnecting the piston of said master compressor with the piston of each of said auxiliary compressors, whereby application of pressure by said master compressor simultaneously actuates said auxiliary compressors to deliver liquid to each of said inflatable envelopes.

3. An expandable mandrel comprising an elongated central shaft; means forming a plurality of U-shaped recesses around the periphery of said shaft; a member positioned in each of said recesses, each of said members having a radially inward surface and a radially outward surface, the radially inward surface of each of said members being formed with a substantially U-shaped slot opening toward the axis of said shaft, the walls of each of said slots and the base of each of said U-shaped recesses cooperating to form a plurality of individual chambers of equal volume; an inflatable envelope positioned in each of said chambers; a separate hydraulic compressor operatively connected to each of said envelopes; and means for simultaneously actuating said compressors, whereby simultaneous actuation of said compressors supplies hydraulic fluid to each of said envelopes at a single rate to inflate said envelopes and thereby move the radially outward surface of said members away from said central shaft into expanded position.

4. An expandable mandrel as set forth in claim 3 including a separate hose operatively connecting each of said hydraulic cylinders to its corresponding envelope to thereby form a plurality of independent expansion systems, the volume of each of said systems being equal to provide for uniform movement of said members.

5. An expandable mandrel as set forth in claim 3 wherein said U-shaped recesses are in the form of longitudinal grooves spaced around the central shaft, the radially outward surface of each of said members is arcuate and each of said members is formed with a stem portion extending into one of said grooves.

6. An expandable mandrel as set forth in claim 3 including means for forcing said members inwardly toward said shaft when said envelopes are deflated.

7. An expandable mandrel as set forth in claim 3 wherein said means forming said U-shaped recesses are annular members spaced along the length of said shaft and said members are annular elastic sleeves, whereby inflation of said envelopes expands said elastic sleeves to move the radially outward surface thereof away from said shaft.

References Cited by the Examiner UNITED STATES PATENTS 1,357,330 11/1920 Laussig 60-54.5 2,115,995 5/1938 Mclnnerney 6054.5 2,289,453 7/ 1942 Randall 242-72 2,741,093 4/ 1956 Riker 242-72 X 2,950,071 8/1960 Tidland 242-72 FOREIGN PATENTS 1,254,383 1/1961 France.

FRANK J. COHEN, Primary Examiner. MERVIN STEIN, Examiner. N. L. MINTZ, Assistant Examiner.