US1875854A

US1875854A - Compound eccentric mechanism

Info

Publication number: US1875854A
Application number: US582409A
Authority: US
Inventors: Cooper George Cecil
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-01-20
Filing date: 1931-12-21
Publication date: 1932-09-06
Anticipated expiration: 1949-09-06

Description

6, 1932. c, COOPER 1,875,854

COMPOUND EGCENIBIC MECHANISM Filed Dec. 21, 1931 Patented Sept. 6, 1932 UNITED STATES, PATENTl-QFFICET GEORGE CECIL ooornn, OF'LONDON, ENGLnNp COMPOUND EooENrR Io MECHANISM Application filed December 21, 1931, Serial No. 582,403, and in Great l3ritain January 20, 1931. 7

This invention relates to improvements in compound eccentric mechanism, particularly applicable for use in vibrating a screening or other surface, or for other purposes in which an adjustable Variation in a reciproeating motion or travel is of service.

In mechanism employing the variable motion derivable from a compound eccentric,

A it has been proposed to vary the eccentricity of a pair of eccentrics, mounted one over the other on a revolving shaft, by means whereby the one eccentric may be moved angularly with respect to the other eccentric whilst the shaft is revolving.

The objects of the present invention are to reduce the number of working parts, produce a more compact, reliable, efficient and positive mechanism, reduce the cost of manufacture and generally improve such mecha- The present invention comprises a pair of co-axially arranged eccentrics, both of which are splined, keyed or otherwise arranged to rotate with a driving shaft, the one eccentric is fixed to the shaft and the other eccentric is free to be moved axially thereon, an outer eccentric mounted on and free to be rotated on the pair of co-axially arranged inner eecentrics, a strap or its equivalent on the "outer eccentric for transmitting the desired motion and means for angularly moving the outer eccentric with respect to the inner pair of eccentrics consisting in the provision of H a stud or studs on the one eccentric adapted to be engaged by a helical slot or slots in the other eccentric, and means for axially sliding the axially movable eccentric.

This invention will be now more particuularly described making reference to the accompanying drawing in which Fig. 1 is a part view in side elevationpartly in section-of one embodiment of this invention.

Fig. 2 is a View in transverse section on line 'II-II of Fig. 1, and 1 Fig. 3 is an enlarged diagram showing the centres of shaft and inner eccentric and path of travel of outer eccentric and centres 50. of the latter in two difierent positions.

Throughout .the views similar parts are" marked with like "letters of reference.

A driving shaft a the axis. of which is designated a is mounted to be revolved in suitable bearings carried'by a frame ac. OIi this shaft a is splined a pair of co-axially. arranged eccentrics b, 0, the common centre of whichis' designatedb The one eccentric bis fixed tothedriving shaft a so as to rotate' therewithin any convenient way, for instance by a key b and setiscrewb. The othertec centric o is free to slide axially on the shaft a but to frotate therewith, a convenient arrangement being to fix akeyLa onithe shaft to engage a,,'lsiey way'o inthe bore oflthepiart c. the pair of inner eccentrics I), c, 'and.free to rotatethereon is mounted an outer eccentric (Lthe: centre of" which is designated 03 rotating round the, centre 6 QA strap e. is carried in a bearing on the outer eccentric d. andis furnished with a rod 6 which is connected to the vi-. brating screenor other mechanism in which an adjustable reciprocating motion or travel is of service, cap or collar 6 retains the strap 6 in position. Angular movement of, the outer. eccentric d relative to the inner eccentrics b, a, isprovided by means of studs or keys ti? projecting :within the bore of the outer eccentricd and adapted to .engagehelical slots c pcut in the surface of the eccentric 0 In some cases, the studs might be carried by the eccentric c, in vwhich case the slots 0, would be cutin the bore of the outerecce'na tric d. In the diagram, Fig. 3, which shows 7 the amountof variation'of travel or rangeoi' adjustment possible with the construction shown, a designates the 'centreof thefdriw' ing shaft, 6 the centre ofthe inner eccentrics b, 0, andthe path of the outer eccentric dis. designatedd p It will' be understood that if the pair of inner eccentrics b c and the outer eccentric d be given the same amount ofeccentricity, it is lpossible, with helicalgrooves extending round the one part, to secure any. required throw of the :compound ,eccentric from nil to maximum.

Any suitable 'mechanismmay' be employed 109 lar 0 is adapted to be engaged a ng d to move the eccentric c axially with respect to the shaft a. In the construction shown, the outer end of the eccentric c is fixed to or made in one with an extension a forming a collar concentric with the shaft a. This colby pins 7 carried by a forked bracket P, the upper end of which is provided with a nut or screwed sleeve f which is engaged by a screw thread 9 formed ona rotatable shaft 9 The forked bracket 7 is carried by fixed guide rods h carried by brackets h fixed on the frame w and is moved thereon so as to impart axial action to the eccentric c by outer eccentric mounted on and-free to be rotated on the pair of co-axially arranged inner eccentrics, a strap on the outer eccentric for transmitting the desired motion, and 7 means for angularly moving the outer eccentric with respect to the inner pair of eccentrics consisting of a helical sloton the one eccentric, a'stud on the other eccentric engaging said helical slot, and screw mechanism for axially sliding the axially movable eccentric of the pair ofco-axially arranged eccentrics.

' GEORGE- CECIL COOPER.

rotating the shaft 9 by means, of a hand wheel 9 V From the above construction, it will be seen that as the mechanism employed to vary the eccentricity of he compound eccentric rotates concentrically with the inner eccen-v tric, the whole gear revolves as a solid unitin any position, all relative motion being avoided between the driving and driven points of contact, which is not possible in previous constructions of mechanism employed in varying the eccentricity of a compound eccentric. .7 V

' I, declare that what I claim and desire to secure by Letters Patent is:- v 1. Compound. eccentric mechanism comprising a driving shaft,a pair of co-axially arrangedeccentrics, splined to, rotate with said shaft, one eccentric being" fixed to and the other. eccentric.

being free tomove axially on said shaft, an outer eccentric mounted on and free to be both of which are rotated on the pair of co-axially' arranged.

inner eccentrics, a strap on tric for transmitting the desired motion,

the outer eccenand ! means for angularly moving the outer eccentricwith respect to the inner pair of eccentries. .7

.2. Compound eccentric mechanism comprising a driving shaft, a pair. of co-axially eccentrics to rotate withsaid shaft,'one eccentric being fixed to and the'other eccentric being. free to move axially on said shaft, an outer eccen-- tric mounted on and free to be rotatedon the pairof co-axially arranged inner eccen tries, a strap on the outer eccentric for transmitting the desired motion, and means for angularly moving the outerveccentric' with respect to the inner pairof eccentrics cons sistlng of a I helical slot on the one eccentric, a Stand on the other eccentric'engaging said helical slot and means for axially'sliding the axially. movable eccentric of the pair of: co-axially arranged eccentrics. g m a 3. Compound eccentric mechanism come,

prisinga driving shaft, a pair of co-axially arranged eccentrics, both of which are splined to rotatewith saidshaft, one eccena tric being fixed to and the other eccentric being free .to move axially on said shaft, an

both of which are splined I no