US818280A - Expanding pulley. - Google Patents

Description

PATENTBD APR. 17, 1906.

A. L. NOL. EXPANDING PULLEY.

APPLICATION FILED NOV. 28

w/T/vasseg.- @uf PATENTBD APR. 17, 1906.

A. L. NOL.

BXPANDING PULLEY.

APPLICATION PILE 3 SHEETS-SHEET 2.

/m/e A/ To f @wws /Mia 0V. 2s. 190s.

WITINESSESI PATENTBD APR. .17, 1906.

A. L. NOEL. BXPANDING PULLEY. APPLICATION FILED NOV. 28. 1903.

3 SHEETS-SHEET (iv HV1/@Nro Amr @Wam/Erm pulleys with their control apparatus.

PAENI FFIQE.

ANDRE LOUIS NOEL, OF PARIS, FRANCE.

EXPANDING PULLEY..

Specification of Letters Patent.

Patented April 17, 1906.

Application NOVGIIJEI 28, 1903. Serial N0' 183,002.

To all whom it may concern:

Be it known that I, ANDR LoUIs NoL, engineer, a citizen of the French Republic, residing at 52 Boulevard Haussmann, Paris, France, have invented a certain new and useful Expanding Pulley, of which the following is a full, clear, and exact description.

The present invention relates to an expanding pulley of which the belt surface presents no break of continuity while at the same time its width remains constant Whatever be the diameter to which it has been extended or expanded. This pulley is illustrated on the annexed drawings, in which- Figure 1 shows the diagrammatic arrangement. Fig. 2 shows in transverse section on line A B of Fig. 3 a method of practically carrying Aout the invention. Fig. 3 is a longitudinal section on line C D of Fig. 2. Fig. 4 is a corresponding plan. Fig. 5 is a transverse section on line E F of Fig. 3 and showing more particularly the control mechanism added to the expansible pulley. Fig. 6 shows, on a smaller scale, the arrangement ofFtwo lgs. 7, 8, 9, and 10 relate to phases in the working of the control mechanism.

In the last-mentioned illustrations Figs. 9 and 10 show the working of the control mechanisms belonging to the two pulleys, respectively, during the lessening of the diameter of one pulley and during the enlarging of the diameter of the opposite pulley.

The principle of construction of this expansible pulley is the following: Let a flexible metallic ribbon a be coiled spirally, taking care to pass the outermost coils, Fig. 1, in superposition through rings b b, leaving, however, the inner coils in a free state. Moreover, let the rings b b be so arranged that they can simultaneously move by equal distances radially from a common center. Under these conditions there is formed outside the coils a cylinder which becomes more perfect as the number of rings l) l) increases and more resisting as the number of coils passed through these rings b l) increases. This external cylinder is able to vary in diameter at each displacement of the radially-moving rings, inasmuch as the coils of which it is formed are free to slide over each other and that the inner coils provide or take up the quantity of ribbon necessary or in excess; but in all adjustments the external circumference of the pulley is without break in continuity and remains substantially concentric to the axis. The pulley shown in Figs. 2, 3, and 4 is based on this principle. In these figures the outer cylinder or rim of the pulley is formed not of one ribbon, but of several metallic ribbons a c, coiled spirally. To reduce to a minimum the projections formed, Fig. 1, by the outer portions of the rings b, these latter are operated as follows: The outer ends of each of the ribbonsaa carry two ears c c, bent down sidewise against the edges of the outer coils and connected to a cross-piece d. These cross-pieces d d of a number equal to that of the spirals d a pass between the portion of the coils forming the drum or rim of the pulley and the portions of the free coils which are inside this rim. In this way all the coils formed by the ribbons a a. are divided into two concentric parts, the outer one being comprised between the ends fitted with ears c c and the cross-pieces d d, the combination of which constitutes the rings b referred to above, and the other inside and entirely free being composed of all the inner ends of the ribbon-coils. In order that the rings thus formed may be able to move radially and by equal amounts, use is made of the following arrangement,without, however, being limited thereto.

The ends of the cross-pieces d d are connected to nuts e e, mounted on screwsffff, placed radially on side plates A and B, which serve as sides or flanges to the pulley. Each radial screw is fitted with a pinion g, intended to communicate to it a ,movement of rotation which, according as it is revolved in one direction or the other, removes from or brings nearer to the center of the pulley the corresponding nut, and consequently the crosspiece d, which replaces the ring l) of thefundamental arrangement. On revolving all the radial screws by equal amounts displacements are obtained such that the outer coils of the ribbons a a are always included between concentric circles, and thus always present a cylindrical contour. Now all the pinions g of the screws situated on the disk A are controlled by a bevel-wheel 7L, formed with a sleeve t' or connected thereto. The movement of this wheel h is communicated, by means of the pinions y" jg, to the screws of the disk B. The disks A and B are secured to a shaft C, while the aforesaid gear-wheels hj and y" and jz are loose on the said shaft and are inclosed in a gear-case D, situated at the center of the pulley and connected at its ends to the disks A and B.

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The control of rotation of the sleeve fi can be obtained in any way-for example, by means of the mechanism shown in the drawings. The object -of this mechanism is to produce the alteration of the diameter by means of the difference of the angular speeds of two disks E and F, one of which is keyed on the shaft C and the other loose on this shaft. The first can when disengaged from the second receive, by means of the frictionrollers G and H and of. a brake I, a motion faster or slower than that of the shaft.

The disk E is ,keyed to a sleeve i, on which it can slide longitudinally. Moreover, it is secured to a clutch-drum S, which allows it to be directly connected to the disk F. The clutching of the disks E and F is effected by the action of a spring C, engaged on the shaft C and bearing against the sleeve i, so as to act on a washer o, screwed into the drum S. Moreover, the disk` F has a raised portion F, forming a race, and the disk E has two similar raised portions E and E2. Between the disks E and F are arranged two friction-rollers G and H, freely mounted on axles g/ and i, secured to a cross-piece L, which is fast to a spindle M, suitably supported at N. The roller G is intended to act either with the race F/ or with that shown at E. The roller H is secured to a third roller V, intended to run on the race E2.

On the clutch-drum S is rolled a metallic band I, designed to brake on this drum and of which the ends are secured to a cross-piece P, forming part of a cross-bar holding the ends ofthe axles g and h', and thus capable of sharing the motion imparted to the crosspiece L by the action of the spindle M.

It must be noticed before describing the working of this control mechanism that, as shown in Fig. 6, the axles C and CX of the two pulleys are connected by the spindles M and Mand bevel-pinions to a control-shaft R, by means of which the operator acts simultaneously, but in opposite directions, on the said parts. It is also to be noticed that in this Fig. 6, as Well as in Figs. 7 and 8,which show the control mechanism in the position of working for the pulleys l and 2, the rollers G, H, and V do not touch the races of the disks E and F, between which they are situated. In these figures the band I of the brake is also Without action on the drum S, and likewise the disk E is clutched with the disk F, the sleeve i revolving under these conditions at the angular speed of the shaft C.

The working is as follows: Assume the two expansible pulleys 1 and 2 to be mounted, respectively, on the shafts C and CX and provided With similar control mechanisms connected by a transmission with a single control R. Suppose that the pulley 1 is of larger diameter than the pulley 2. In the following description the arts of the mechanism relating to the pu ley l are designated by reference-letters without exponent, while the same parts of the mechanism of pulley 2 are designated by reference-letters bearing the exponent Xf If the control device R be gently turned in the direction of the arrow in Fig. 6, this rotation is transmitted in opposite directions to the spindles M and M and causes the cross-pieces L and L of the two control mechanisms to assume the positions shown, respectively, in Figs. 9 and 10.

In the case of Fig. 9 the roller V has first pushed back the disk E and has displaced it longitudinally with regard to the shaft C, unclutching it from the disk F. The disk E as well as the sleeve i have thus been made loose on the shaft C. Further, the roller G has afterward come into contact with the disk F, keyed on the shaft C. At this instant the disk F draws along the roller G, which communicates its motion by means of the roller H to the roller V, which by reason of the relation of the diameters is impressed with a greater angular speed, so as to transmit to the disk E and to the sleeve i a movement of rotation greater than that of the disk F, and consequently of the shaft C and of the entire pulley. This relative motion (by increase) of the sleeveiwithregard to the pulley l, Fig. 6, is actually utilized to operate the parts of this pulley and to determine the reduction or diminution of its diameter. It is to be noticed that in the case of the reduction of the diameter of the pulley the cross-bar P acts on the brake-band I so as to free the latter more and more from the drum S and to afford no obstacle to the acceleration of the rotary motion of the disk E.

In the case of Fig. l0 the roller GX has first pushed back the disk EX and displaced it longitudinally with regard to the shaft CX by unclutching it from .the disk FX. The disk EX and the socket have thus been rendered loose on the shaft CX. Moreover, the crossbar FX has subsequently taken up a position such that the brake-band IX rubs on the drum S, so as to slow down its motion, as well as that of the disk EX and that of the sleeve iX with relation to the rotary motion of the shaft CX. It is to be noticed that the rollers HX and VX revolve idly, contrary to what happens in the case of Fig. 9. The relative motion (by decrease) of the sleeve 72X with regard to the pulley '2 is used to operate the parts of this pulley and to determine the extension or increase of its diameter.

When the results given with regard to Figs. 6, 9, and l() have been produced, the frictionrollers of the control mechanism of each pulley are returned to the neutral or resting position, Figs. 6 and 7, and the disks E and F of each of them are reclutched, While the pulleys rotate with the new diameters that have been given them. It is to be noted, and this is the most important point in the system, that the two actions produced are unequal in the IOO IIO

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'sults from the `friction of the brake.

sense that the iirst results from the rolling friction of the rollers, while the secondT1e1 e rst is then constant whatever be the effort applied to it and cannot exceed the limit assigned to it by the difference in diameter of the rollers G, II, and V and their races F E E2, while the second increases proportionally to this effort and might become sufficiently great to arrest the disk E completely. This difference in the transmission to each of the pulleys of the force exercised on the device for controlling the variation in diameter is important. This difference practically allows one to operate at once on the two pulleys 1 and 2 without fear of any slipping of the belt T. There is rather room for fearing the contrary effect if the brake was not arranged in construction with a limit of adhesion proportioned to the resistance of the belt. As soon as the tension of the belt reaches the value assigned in construction to this maximum adhesion the brake partly slips and, further, the rollers continuing to lessen the diameter of the other pulley the increase in diameter of the braked pulley can take place only in proportion to the lengths of belt yielded by the other pulley by reason of its decrease of diameter. Thus the belt balancing the excess of increase in diameter' of one of the pulleys over the other will be constantly tensioned and that as much as has been previously decided in the construction. This property of the system described is permanent, since the operation indicated for lessening the diameter oi the pulley l and increasing that of pulley 2 can be effected in the opposite sense by acting inversely on the control-shaft R. Moreover, it may be remarked, that apart from the times when the diameters are being changed, the pulleys having their disks E and F clutched and consequently revolved together, the belt works only to transmit the force of the motors.

I claim as my inventionl. An expansible pulley, comprising side plates, radially-movable cross-pieces secured thereto, ribbons secured one to each crosspiece, and passing freely through all other cross-pieces in coils, a substantially continuous belt-surface being formed thereby.

2. An expansible pulley, comprising side plates, a shaft, a gear-case, cross-pieces between the plates, coiled ribbons secured at one end to the cross-pieces, nuts on the crosspieces, radially-arranged screws and gears therefor in the gear-case, and threaded into the nuts, a sleeve adapted to operate the gears and means for rotating said sleeve on the shaft or locking it thereto, substantially as described.

3. An expansible pulley comprising a shaft, side plates, radially-arranged screws thereon, cross-pieces carried thereby and carried by the screws, coiled ribbons secured one to each cross-piece, a substantially continuous beltsurface being formed thereby, a gear-case, pinions on each screw within the gear-case, gearing within the gear-case connecting the pinions on each side of the gear-case, a sleeve adapted to operate the pinions on one side of said gear-case and means to lock said pinion to the shaft or rotate it thereon, substantially as described.

4. An expansible pulley, having a shaft, a belt-surface and means to change its diameter, comprising a pair of disks, one rotating with the shaft, and one adapted to either be locked thereto or to rotate independently thereof, a friction-clutch adapted to retard the motion of one disk with relation to the shaft to produce one change of diameter, and a positive driving means to produce the opposite change in diameter.

5. In combination with a shaft, an expansible pulley comprising a sleeve free to rotate on the shaft, two disks, one rotating with the sleeve, and one rotating with the shaft, a clutch between them, means for separating the disks to unclutch them, and a brake to retard the motion of the sleeve, said separating means adapted to rotate the disks oppositely.

6. In combination with a shaft, an expansible pulley comprising a sleeve free to rotate on the shaft, two disks, one rotating with the sleeve and the other with the shaft, a clutch between them, a spindle having a pair of geared driving-wheels carried between the disks, a brake operatively connected to said spindle, and means for turning the spindle to unclutch the disks, and cause the geared driving-wheels to bear upon the disks to rotate them oppositely.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ANDRE LOUIS NOEL.

Witnesses:

GUsTAvE DUMONT, I-I. C. CoxE.

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