US3149403A

US3149403A - Molded magnetic rolls

Info

Publication number: US3149403A
Application number: US183167A
Authority: US
Inventors: Christoph W Aurich; Edward A Bragg
Original assignee: Maremont Corp
Current assignee: Maremont Corp
Priority date: 1962-03-28
Filing date: 1962-03-28
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22
Also published as: GB1020488A; DE1249131B; CH434043A; ES283870A1

Description

569% 1964 c. w. AURlcH ETAL MOLDED MAGNETIC RoLLs Filed March 28, 1962 ff/W United States Patent O 3,149,403 MOLDED MAGNETIC ROLLS Christoph W. Aurich and Edward A. Bragg, Clemson, S.C., assignors, by mesne assignments, to Maremont Corporation, Chicago, Ill., a corporation of Illinois Fiied Mar. 28, 1962, Ser. No. 183,167 6 Claims. (Cl. 29-1295) This invention relates to drafting devices of the type used in textile machines and more particularly to magnetic drafting elements having a novel plastic-type housing.

Magnetic drafting rolls for use in textile machines, such as spinning and roving frames and the like, have recently gained great commercial acceptance. The reason for this acceptance is that they have eliminated the necessity of using complicated and cumbersome weighting devices to assure adequate gripping of a sliver passing between top and bottom rolls.

Heretofore, magnetic top rolls have comprised a plurality of elements manufactured independently of each other. Thus, a typical roll would have a cylindrical magnet, a hollow sleeve portion to house the magnet, pole pieces, pole piece extensions, and gudgeons. Typically rubber cots of uniform thickness are provided to tit on a reduced portion of the sleeve. Because of the necessity of assuring even pressure of the rolls on the sliver each element of the roll necessarily was carefully machined to provide concentricity of the pieces. Moreover, a grinding operation was necessary after the final assembly to further insure concentricity. With the exception of the cots each piece would be of strong metal. As can well be imagined, such a construction was extremely expensive.

It is to these problems that the present invention addresses itself. The major object of this invention is to provide a magnetic top roll, of extremely simple construction, which has built-in concentricity without the necessity of machining.

In general, this present invention comprises a permanent magnet and permanently aiiixed or integrally formed pole pieces embedded in a molded plastic shell.

Other features, objects, and advantages of the present invention will be apparent to those skilled in the art from the following detailed description thereof and the accompanying drawings, wherein:

FIG. l is a side elevation in section of one embodiment of the invention;

FIG. 2 is a view of FIG. 1 taken along the line 2-2; and

FIGS. 3 and 4 are views similar to FIG. l of alternative embodiments of the invention.

In referring to the drawings and more particularly to the construction shown therein of the end portions of the rolls only one end will be described as the opposite end of each embodiment is identical thereto.

In the drawings are shown several embodiments of this invention. It will be there noted that a cylindrical permanent magnet is provided. A pole piece 12 is provided which is permanently afxed to the magnet 10 as is in FIG. 1 by means of solder or other such means, or which is an integrally formed ange portion of the magnet 10 as in FIGS. 3 and 4, and which has a larger diameter than that of the center portion or body of the magnet 10. A plastic, nonmagnetic material is provided as a shell about the circumference of the magnet 10 at 14 leaving the pole pieces exposed however on their circumferential surfaces. Plastic 16 also is provided at the end portions of the magnet of a reduced diameter relative to that of the pole pieces 12. Cots 18 of rubber or the like, of uniform thickness, are mounted on the platsic end portions 16 and extend radially outward farther than the pole pieces 12.

3,149,493 Patented Sept. 22, 1964 "ice Where the magnet 10 is solid as in FIG. 1 an extension 11 is provided on the pole piece 12, of an irregular configuration, adapted to be grasped by the plastic end portion 16, and thus to maintain in predetermined position said end portion. Where, however, the magnet 10 has a hollow portion, as in FIGS. 3 and 4, extending therethrough, a plastic core 17 is formed therein which maintains the end portion 16 in its predetermined position. lf gudgeons 20 are desired, they are inserted in the end portion 16 as in FIG. 4.

To construct such a roll, the pole pieces and magnet are first assembled, if they are separate. The nished magnet and pole pieces are then inserted into a mold having locating dimensions corresponding to the diameter of the pole pieces and the length between the outer radial surfaces of the pole pieces. If gudgeons are to be provided, they are also aligned in the mold. The plastic material is then injected into the mold. The plastic used snould have low shrinkage values to prevent cracking and checking.

On removal of the roll from the mold no additional machining is necessary. The only final assembly is to mount the cots. Where gudgeons are used, one final grinding operation may be necessary to assure concentricity between the gudgeons and the pole pieces. If the mold is accurately formed, however, even this grinding operation may be deemed largely unnecessary.

Thus this invention greatly simplifies the construction of magnetic top rolls. A plurality of elements is eliminated. A greater degree of accuracy is achieved in attaining concentricity of elements than was heretofore possible and several expensive grinding operations are eliminated.

It will be apparent to those skilled in the art that many modications of this invention may be made without departing from the true scope thereof.

What is claimed is:

l. A molded magnetic drafting element having a cylindrical permanent magnet,

at each end of said magnet a pole piece concentric thereof and permanently aixed thereto, said pole pieces being of equal diameter, greater than the diameter of said magnet, and each of said pole pieces having an exposed circumferential surface,

a shell of molded plastic material extending between said pole pieces and about the circumferential surface of said magnet thereby encasing said magnet,

a cylindrical end portion of molded plastic material concentric of and permanently aixed to each of said pole pieces, said end portions being of equal diameter and being adapted to have cots mounted thereon, and

a cot of rubber-like material of uniform thickness mounted on each of said end portions, said cots being of equal thickness and having inner diameters equal to the diameters of said end portions.

2. The element claimed in claim l wherein said pole pieces are integral portions of said magnet forming radially extending fianges thereof.

3. The element claimed in claim l wherein said pole pieces have axially extending portions of irregular conguration and wherein said end portions embrace said axially extending portions, said end portions thereby being permanently aixed to said pole pieces.

4. The element `claimed in claim 1 wherein said magnet and said pole pieces have a hollow portion axially extending therealong and wherein a core of said molded plastic extends through said hollow portion integrally connecting said end portions, said end portions thereby being permanently aixed to said pole pieces.

5, The element claimed in claim 1 wherein a gudgeon extends outwardly from each of said kend portions and wherein each said gudgeon is concentric of said pole pieces.

6. The element claimed in `claim 1 wherein said cots have an outer diameter which is greater than that of either said shell or said pole pieces.

Referencesl Cited in the le of this patent UNITED STATES PATENTS

Claims

1. A MOLDED MAGNETIC DRAFTING ELEMENT HAVING A CYLINDRICAL PERMANENT MAGENT, AT EACH END OF SAID MAGNET A POLE CONCENTRIC THEREOF AND PERMANENTLY AFFIXED THERETO, SAID POLE PIECES BEING OF EQUAL DIAMETER, GREATER THAN THE DIAMETER OF SAID MAGNET, AND EACH OF SAID POLE PIECES HAVING AN EXPOSED CIRCUMDFERENTIAL SURFACE, A SHELL OF MOLDED PLASTIC MATERIAL EXTENDING BETWEEN SAID POLE PIECES AND ABOUT THE CIRCUMFERENTIAL SURFACE OF SAID MAGNET THEREBY ENCASING SAID MAGNET, A CYLINDRICAL END PORTION OF MOLDED PLASTIC MATERIAL CONCENTRIC OF AND PERMANENTLY AFFIXED TO EACH OF SAID POLE PIECES, SAID END PORTIONS BEING OF EQUAL DIAMETER AND BEING ADAPTED TO HAVE COTS MOUNTED THEREON, AND A COT OF RUBBER-LIKE MATERIAL OF UNIFORM THICKNESS MOUNTED ON EACH OF SAID END PORTION, SAID COTS BEING OF EQUAL THICKNESS AND HAVING INNER DIAMETERS EQUAL TO THE DIAMETERS OF SAID END PORTIONS.