US 2172230 A
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Description (OCR text may contain errors)
l, D. M. wA'rsoN 2,172,230
VARIABLEPITCH PULLEY md Dec. -12, 195e Sept. 5, 1939.
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Patented sept. s, 1939- UNITED STATES vAmAnLE-rircn PULLEY David M. Watson, Ardsley, Pa., assignor'to The American Pulley Company, Philadelphia, vPa., a corporation of Pennsylvania application December 12, 193s, serial No. 115,491
The primary object of this invention is the provision of a pulley of the kind above indicated including a rotary member adapted to affect concurrent approach or receding' of the pulley groove-forming components relative to one another.
Another object is the provision of a multigroove variable-pitch pulley in which the several 15 groove-forming components lare concurrently movable to vary the effective diameter of said pulley without disturbing the respective centers of the belts being driven thereby.
A further object is the provision of a variablepitch pulley of the type indicated comprising but few parts which are simple to construct, and when assembled are easy to manipulate for changing the active diameter of the pulley; while being immune to relative movement when set at the required adjustment.
Other objects and advantages, more or less ancillary to the foregoing, and the manner inwhich they are realized, will become apparent from an examination of the following description which, considered in connection with the accompanying drawing, sets forth a preferred embodiment of the invention.
Generally stated, this invention consists yof the novel items, combinations of means and arrange- 85 ment of the parts hereinafter disclosed, illustrated by the drawing, and more concisely expressed in the claims at the conclusion of this specication.
In the drawing: 'y Fig; I is a view of the improved pulley, partly in elevation and partly in section, as viewed in the direction of the plane-designating arrows I-Iin Fig. II. V
Fig. II is a section on the plane marked II-lI 45 in Fig. I. Y
Fig. III is a fragmentary sectional view, taken as indicated by the arrows III-III in Fig. II.
Fig. IV is a perspective view of a sleeve hub member hereinafter particularly/ described; and,
Fig. V is a perspective view of an adjusting collar, likewise later on fully explained,
In all the views, corresponding parts are designated by like reference characters.
Referring more in detail to the drawing. the numeral I designates a broken portion of a drive shaft. 2 a sleeve pulley-hub which is held against rotation relative to said shaft by a spline 3 and secured against axial movement by a set-screw 4. The hub 2, as best understood from Fig. IV, in-
cludes a cylindrical sleeve-like main portion 5 5 l with an enlargement 6 at one end radially apertured and screw-threaded at 1 for passage of the set-screw 4 aforesaid. Remote from the enlargement 6, the sleeve-like main portion 5 is reduced to form a shouldered abutment 8, and l further reduced and provided with a right-hand screw-thread at 9 for a purpose later on again 'referred to. The bore lof the hub 2 isv longitudinally grooved at I0 for reception of the spline 3,
and externally formed with an opposing keyl Way Il.
Slidably fitting the hub 2 are a series of longitudinal angle-section groove-forming components I2, I3 and Il, with opposing discous components I5, I6 and I'l, jointly providing V-grooves 20 I8. Attention isrdirected to the fact that the discous components I6, I 1 Slidably fit the tubular porions I9 of the components I3, I4; whereas the discous component I5 has a relatively larger bore provided with an internal left-hand screw- 25 thread for operative coaction with a corresponding external screw-threaded -portion 2| of an adjusting collar 22. This collar 22, it is.to be remarked, is formed with an inwardly-projecting portion 23 of a dimension for free rotative 30 movement on the hub shouldered abutment 8, as
-well as an internal portion provided with a righthand screw-thread 24 for operative coaction with the correspondingly threaded-exterior 25 of the tubular portion I9 of the groove-forming com- 36 ponent I2.
Inl order to prevent rotation of the grooveforming components I2, I3 and I4 relative to the hub 2, use is made of a spline 26 engaging thekeyway II and conformative slots II' through the 40 tubular portions I9 oi' said components; whereas similar displacement of the discous components I5, I6 and I'I with respect to the components `I2-II aforesaid is obviated by circumferentiallyspaced screws 21, the heads whereof seat in borings through the disc component I5 and their ends Abeing screw-threaded at 28 into the disc component I l, with spacers 29 intervening the component I6 and said components I5, I1.
'Ihus it will be readily understood the disc com- 5ol ponents I6, I1 are rigidly connected'to the component I5, with capacity for axial movementl on the tubular portions I9 of the components .I2-I4 through the medium of the adjusting collar 22,
In order to prevent relative circumferential From the foregoing disclosure it will be clearly apparent that in order `to change the pitch diameter of the pulley, all that is necessary to be done is to simply revolve the adjuster collar 22,4
which is preferably provided with circumferentialiy spaced holes 34 for application of a span-v ner-wrench, in an obvious manner. Revolving or turning of the adjuster collar 22 in a, clockwise direction will move thcA sheave or grooveforming components I2--I4 toward said collarand, at the same time, move the disc components I 5-I1 away therefrom at acorresponding rate of travel; or, in other words, the grooves I8 will be contracted with expansion of the eectivediameter of the pulley. v0n the contrary, when the adjuster collar 22 is rotated in an anti-clockwise direction, a reverse action takes place -between the several groove-forming components I2l1 whereby. the eilective diameter of the pulley is decreased and, in both cases, without disturbing the alignmentof the belts driven thereby. The adjuster collar 22 and all of the pulley-forming lcomponents are restrained against ain'al shifting at the required adjustment by the hub shouldered-abutment 8 in one direction, and by a retaining collar or lock-nut 35 applied to the screwthreaded end 9 of the hub 2 in the other direction; said nut being secured by a drift pin 3B or the like, in accordance with known practice.
While a specific embodiment of the invention has been illustrated and described, it is to be understood that alteration in the details of con-4 struction may be effected without departing from the spirit and scope of said invention as indicated in the following claims.
Having thus described my invention, I claim: 1. In a variable-pitch pulley, .coaxial grooveforming components movable toward or away from each other, one of the said components embodying an externally screw-threaded portion and the companion component anl internally screwthreaded coaxial oriiice, said screw-threads being dierential, means restraining said components against relative rotation, and an adjuster collar having interior and exterior screw-threads respectively cooperative with the corresponding external and internal component threads to effect their axial separation and vice versa.
2. In a variable-pitch pulley, coaxial grooveforming components movable toward or away from each other, one of the groove-forming components embodying a tubular portion having an external right-hand screw-thread and the .companion component; an axial orice of larger diameter with an internal left-hand screw-thread, means restraining said components against relative rotation, an adjuster collar having interior and exterior screw-threads of corresponding pitch cooperative with the exterior and interior threads of the companion components respectively, and said collar includes means for engagement with appropriate stops to restrain -it against shifting in an axial direction. l
'3. A multi-groove variable-pitch pulley comprising serial sheave units each including opposed growing-components, the complemental grooveforming components for each groove embodying tubular portions and one of which is externally screw-threaded, companion components some of which slidably engage the tubular portions of the rst mentioned components and another .is ori- -ced and provided with an internal screw, threaded ina reverse direction tothat of the tubular portion of its companion groove former, rigid means vconnecting the 'alternating groove-forming components for concurrent axial movement,
and an adjuster member in the form of a collar having inner and outer screw-threads respectively cooperative with-the external 'and internal screw threads aforesaid to eiect variation in the pitch diameter of the pulley.
4. A multi-groove variable-pitch pulley comprising serial sheave units each including opposed complementa] groove-forming components, one
4series of the complemental groove-forming components embodying tubular portions and one of which-is externally screw-threaded, companion vcomponents lsome of which slidably engage the tubular portionsvof the first mentioned components and another is oriilced and provided with an internal screw, threaded in a reverse direction to that of the tubular portion'of its companion groove former, circumferentially arranged spacer means rigidly connecting the components having tubular portions, similarly allocated rigid elements connecting the companion elements together, and an adjuster member in the form of a collar having inner and outer screw-threads respectively cooperative with the external and internal screw threads aforesaid to effect variation in the pitch diameter of the pulley, said collar also embodying an inwardly-projecting portion Ifor coaction with suitable stop means to prevent itsaxial shitting.
5,'A multi-groove variable-pitch pulley comprising a sleeve hub with means for restraining it against axial displacement, a plurality of sheave-forming components.A embodying coaxial tubular portions splined exterlorly on said hub, a corresponding plurality of opposing sheave-forming axially-oriced components movable over the companion component tubular portions at one side of the pulley, one of the end tubular portibns having an external right-hand screw-thread and the companion component orifice being provided with a left-hand screw-thread, an adjuster collar having inner and outer right-hand and left-hand screw-threaded portions respectively cooperative with the tubular portion and orifice threads aforesaid, means conning said sleeve to rotative movement only -to vary the pitch diameter of the pulley, means 'limiting the oriced sheave-forming components to simultaneous axial movement, and means for, restraining the adjuster collar and all of the pulley forming components against axiial shifting lengthwise of the sleeve hub afores d.
6. A multi-groove variable-pitch pulley as defined in claim 5 wherein the means conning the adjuster collar to rotative movement comprise an inwardly-projecting concentric portion of said collar rotativelyfltting a shouldered or reduced part of the sleevehub proximate one end, and a retainer-collar threadedly engaging the adjoin- 'ing outer end of said hub. said latter parts being secured together by a pin driven between their engaged surfaces.
DAVID M. WATSON.