US1363310A - Multiple expansion-arbor - Google Patents

Description

Patented Dec. 28, 1920.

2 SHEETSSHEET I.

W T CHRISTOPHER MULTIPLE EXPANSION ARBOR.

APPLICATION man NOV. 22. 1919.

W. T. CHRISTOPHER.

MULTIPLE EXPANSION ARBOR.

n I APPLICATION FILED NOV. 22.1919- lpfiSfilOu Patented Dec. 28, 1920.

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UNITED STATES PATENT OFFICE.

MULTIPLE EXPANSION-ARBOR.

Specification. of Letters Patent.

Patented Dec. 28, 1920.

Application filed November 22, 1919. Serial No. 339,844.

T 0 all whom it may concern:

Be it known that I, WALTER T. CHRISTO- II-IER, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Multiple Expansion-Arbors, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to arbors or mandrels designed to be used between centers on machine tools such as lathes or the like, and particularly to an expanding arbor or mandrel.

The general object of my invention is to provide a very simple mandrel to be used between centers and upon which work to be turned or machined is mounted, the mandrel consisting of a plurality of diametrically expansible sections, these sections being expanded by turning up the tail stock of the lathe or like machine.

A further object is to provide a mandrel of this character in which the arbor or mandrel is expanded at a plurality of points with even pressure at all points.

And a further object is to provide a con struction of this character wherein there is a ball bearing center used in conjunction with the mandrel at one end thereof whereby to take up the thrust and permit the rotation of the mandrel against the action of the cutting tool.

A further object is to provide an arbor or mandrel which may be readily removed from the machine by simply releasing the tail stock at the completion of the travel of the cutting tool.

Other'objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is a longitudinal sectional view of an expanding. mandrel or arbor constructed in accordance with my invention, certain of the sections being shown in elevation;

Fig. 2 is a longitudinal sectional view of the. middle section A;

Fig. 3 is an end elevation thereof;

Fi 4 is a longitudinal section of the section Fig. 5 is an end elevation thereof;

Fig. 6 is a perspective view of the center section D;

Fig. 7 is a perspective view of the section B;

8 is a perspective view of the middle sect on A, Fig. 9 1s a perspective view of the section C;

Fig. 10 is a fragmentary perspective view of one of the centering sections formed by the members E and F, the casing ring for the ball bearings being removed;

Referring to these drawings, it will be seen that my improved mandrel or arbor is made up of a plurality of sections. The middle section, disposed midway between the centers, is designated A and comprises a cylindrical body 10 having conical bores 11 at its opposite ends, each conical bore 11 terminating at its inner end in a longitudinal extension 12 of uniform diameter. This section A at opposite ends is longitudinally slotted at a plurality of points, as at 13. This section in actual practice will be about 5 long and g" in diameter, though it is obvious that these measurements will vary. Engageable with the opposite ends of the section A are the sections B and C. Both these sections are alike and each section comprises a cylindrical body 14 having uniform diameter and cut away at one end, as at 15, to form a shoulder and from this shoulder tapering uniformly in one direction, as at 16. This conical portion 16 fits into the corresponding conical socket 11 in the section A. At its opposite end, each section B or C is formed with a centrally disposed, conical socket 17 and is longitudinally slotted, as at 18. These slots extend approximately the length of the corresponding socket. The section B is formed at its outer end remote from the tapering portion 16 with an enlarged shoulder 19, the slots 18 extending through this shoulder. This tapering socket 17 is preferably hexagonal or many-sided incross section on the section B, but the socket 17 on section 0 is circular in cross section. Coact'ing with the section B is a center D which, at its middle portion, has a diameter slightly greater than the exterior diameter of the shoulder 19 and is formed on one side of this middle portion 20 with a hexagonal, tapering portion 21 fitting within the socket 17 of the section B and on the opposite side of the middle portion 20 with a conical portion 22 which is circular in cross section. The portion 21 has a length somewhat greater than the hexagonal socket 17. Its smallest diameter is the same as thediameter of the small-.

est portion of the socket 17, while its largest diameter is greater than the largest interior diameter of the socket 17, as illustrated clearly in Fig. 1. The portion 22 which is formed with a Morse taper is designed to be engaged by the spindle of a lathe or like machine. 7

Designed to engage the socket in the sec tion C is a center section E which is formed to provide a body of uniform diameter, designated 23, a shoulder 24 and tapering portion 25 having a length slightly greater than that of the socket 17 in section C, and this section E is formed with a central bore 26. Coacting with this member E is a center member or section F having a cylindrical body 27, on one face provided with the central gudgeon 28 and on its opposite face havin a tapered portion 29 formed with a i. orse taper which is ada'pted'to be engaged by the tail stock of the lathe or like machine.

It will be seen that when the several sections as described are engaged with each other, that pressure applied longitudinally will cause those portions of the members A, B and C which are slotted to be expanded and that as the section A is slotted at oppo site ends and the sections B and C are each slotted at one end, the mandrel formed of these sections A, B and G will be expanded at four points. It will be likewise seen that the hexagonal member 21 will cause the expansion of the section B, while the conical or tapering end 25 will cause the expansion of the member C. It will likewise be seen that the section D will cause the rotation of the various sections B, A, C and E and that the anti-friction'balls 30 between the sections E and F will take up the thrust and allow the arbor or mandrel to rotate. Inasmuch as the carrying center D has a hexagonal portion 21, this will allow the entire arbor to be removed from the machine by simply releasing the tail stock at the completion of the travel of the cutting tool.

In order to cause the sections B and C to rotate with the section A, the tapering portion 16 of these sections B and C are transversely perforated, as at 31, and the opposite ends of the section A are transversely perforated, as at 32, these perforations 32 being smaller than the perforations or passages 31 so as to permit pins to be disposed through the sections A and B and the sections A and C, thusj oining thesesections together for uniform rotative movement. The perforations 31 are elliptical in cross section. The major diameter of the ellipse is longer than the diameter of the pins inserted through the perforations 32, thus permitting a longitudinal movement of the sections B and C relative to the section A.

It will be obvious that this expanding arbor or mandrel is very simple in construction, maybe easily applied and removed from the Work and from the machine with which it is designed to operate, and that it provides an expansion arbor which does not require to be operated by air pressure or hand labor. t will be obvious also that this arbor or mandrel may be used for engaging one or more objects simultaneously with an even pressure. It will further be seen that the expansion of the mandrel or arbor takes place at a plurality of points and that this expansion is the same at any point of expansion.

Furthermore, it will be noticed that the expansion is caused by shifting the tail stock inward and this action will not prevent the free rotation of the mandrel or arbor because of the friction balls 30 disposed between the members or sections E and F This arbor or mandrel can be removed from the machine tool without the aid of small tools, and inasmuch as the carrying center D has a hexagonal portion, the entire arbor may be removed from the machine by simply releasing the tail stock at the completion of the travel of the cutting tool.

I claim 1. An expanding mandrel comprising a plurality of alined sections, each section having a socket into which the other section fits, each socket being longitudinally split and the interfitting end of the other section being tapered to cause the expansion of said split portions of the several sections upon the longitudinal movement of the sections toward the middle of the mandrel.

2. An expanding mandrel formed of a plurality of interfitting sections causing the expansion of the mandrel by movement toward the middle of the mandrel, and coacting members operatively engaging one end of the mandrel and formed of two interfitting sections with anti-friction elements disposed between the sections forming a thrust bearing.

3. An expanding mandrel including a middle section formed with tapering sockets at its ends, these tapering sockets being longitudinally split and the sections at each end of the middle section and end sections having tapering portions fitting in said sockets and adapted to expand the latter upon longitudinal movement of said end sections toward each other.

4. An expanding mandrel including a middle section formed with tapering sockets at its ends, these tapering sockets being longitudinally split. and the sections at each end of the middle section and end sections having tapering portions fitting in said sockets and adapted to expand the latter upon longitudinal movement of said end sections toward each other, each end section having at its end opposite the tapering portion a tapering socket, the socket being longitudinally split at a plurality of points, the tapering portions of said end sections and the socket portions of the middle section being formed with transversely extending, reg istering passages whereby the sections may be pinned to each other, the passages in the tapering portions of the end sections being longitudinally elongated.

5. An expanding mandrel including a middle section formed with tapering sockets at its ends, these tapering sockets being longitudinally split and the sections at each end of the middle section and end sections having tapering portions fitting in said sockets and adapted to expand the latter upon longitudinal movement of said end sections toward each other, each end section having at its end opposite the tapering portion a tapering socket, the socket being longitudinally split at a plurality of points, the tapering portions of said end sections and the socket portions of the middle section being formed with transversely extending, registering passages whereby the sections may be pinned to each other, the passages in the tapering portions of the end sections being longitudinally elongated, centering sections having tapered portions adapted to fit within the sockets of the end sections, one of said centering sections and the corresponding end section being many-sided in cross section.

6. An expanding mandrel including a middle section formed with tapering sockets at its ends, these tapering sockets being longitudinally split and the sections at each end of the middle section and end sections having tapering portions fitting in said sockets and adapted to expand the latter upon longitudinal movement of said end sections toward each other, each end section having at its end opposite the tapering portion a tapering socket, the socket being longitudinally split at a plurality of points, the tapering portions of said end sections and the socket portions of the middle section being formed with transversely extending, registering passages whereby the sections may be pinned to each other, the passages in the tapering portions of the end sections being longitudinally elongated, centering sections having tapered portions adapted to fit within the sockets of the end sections, one of said centering sections and the corresponding end section being many-sided in cross section, the opposite centering section being formed in two parts rotatably engaged with each other and having antifriction bearings disposed between the two parts.

7. In a mandrel expanded by longitudinal thrust, two coacting members, one of said members being tapering toward one end and formed with a socket in its other end, the other member being formed with a hub r0- tatably engaging in the socket and having a tapered portion extending oppositely from said hub, and anti-friction bearings disposed between the two members.

In testimony whereof I hereunto aflix my signature.

WALTER T. CHRISTOPHER.

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