US1871960A

US1871960A - Electromagnetic clutch

Info

Publication number: US1871960A
Application number: US353551A
Authority: US
Inventors: Cotal Jean
Original assignee: BREV COTAL SOC D EXPL DES
Current assignee: BREV COTAL SOC D EXPL DES; D'EXPLOITATION DES BREVETS COTAL Ste
Priority date: 1928-04-26
Filing date: 1929-04-08
Publication date: 1932-08-16
Anticipated expiration: 1949-08-16

Description

Aug. 16, 1932. J. COTAL 138713960 ELECTROMAGNETIC CLUTCH Filed April 8. 1929 Patented Aug. 16, 1932 7 UNITED STATES PATENT OFFICE.

JEAN COTAL, OF PARIS, FRANCE, ASSIGNOB TO SOCIETE DEXPLOITATION DES BREV ETS OOTAL, OEZPARIS, FRANCE ELECTROMAGNETIC CLUTCH Application filed Apr1l'8, 1929, Serial N0. 353,551, and in France April 26, 1928.

ture cannot be kept sulficiently small and.

constant to provide for the clutch contact with a small initial exciting action, such as is necessary to actuate the apparatus in a progressive manner, for in fact the initial air-gap becomes greater and greater, and in a short time the apparatus must be enerized to such a degree that a violent contact is the result, so that-the parts are drawn forward in an abrupt manner, and the whole driving gear will be thus subject to severe shocks.

The invention relates to a special clutch device assuring a constant and well-determined air-gap between the electro-magnet and its armature.

The accompanying drawing shows by way of example a longitudinal section of a constructional form of the clutch according to the invention as applied to a speed changing device.

To the driving shaft 1 is secured an elec tromagnet 2 whose respective armature 4 is secured to a toothed wheel 6.

The clutch device comprises a ring 33 which is slidable by easy friction in the interior of the armature 4, and suitable springs 34 urge the said ring with a suflicient pressure against the internal shoulder 36 of the armature 4:

The ring 33 comprises an annular projection 37, which makes contact with a corresponding annular projection 38 on the elecb tro-magnet 2, and this contact takes place at a light pressure produced by a spring 35 E whose tension is distinctly less than the sum 1 of the tensions of the said springs 34, and thus when in the inoperative position, the said projections 37 and;"38 will be in contact 'due to the action 'ofthge spring 35, and the said shoulder 36 ;of the; armature 4 is urged by the springs against the ring 33, thus ,assuring an air -gapof a few tenths of a millimeter between the .said armature 4 and its electro-magnet.

Under a weak exciting act-ion, the armature 4 is at once attracted by the electro-lnagnet 2, thus compressing the springs 34, since the air-gap has but a very small magnetic resistance.

When the exciting action ceases, the arma ture 4 is brought back by the springs 34 and again makes contact with the ring 33, thus forming with the electro-magnet 2 an air-gap of a well-determined value. The wear produced between the contacting surfaces of the armature 4 and of the electromagnet 2 and which has the tendency to increase the distance between the armature 4 and the electromagnet 2 in the-inoperative position is compensated by the wear produced between the

projections

37 and 38 and causing the ring 33 andconsequently the armature 4 to be brought nearer the electrom'agnet 2. 'The members 6, 4, 33 and 34 are always rotated as a whole about the axis of shaft 1, so that no appreciable wear is produced between the ring 33 and theshoulder 36.

Havingnow described my invention what I claim as new and desire to secure by Letters Patent is:

1. An electro-magnetic clutch comprising a driving rotatable shaft, an electromagnet carried by said driving shaft, an armature for said electromagnet rotatably mounted coaxially with relation to said driving shaft, means for guiding said armature towards and away from said electromagnet, a stop member, means adapted to hold said stop member in a fixed position with relation to said electromagnet, and yielding means adapted to urge said armature against said stop mem- 2. An electro-magnetic clutch comprising 3 An e lectro-magnetic eiutch comprising a driving rotatable shaft, 1m electromagnet carriedby said driving shaftjan armature for said electronmgnet rotatably mounted coax ially with relation to said driving shaft. meansfor guiding said arrflature tpvards and away from said electromagnet; a stogknember,

yielding means bearing at one ehd on said stop member and at the other end on one side of said armature, whereby said armature is urged against said stop member, and other yielding means of less strength than said first JEAN COTALQ