US435083A - Governor for steam-engines - Google Patents

Description

2 Sheets-Sheet 1.

(No Model.)

S. S. BABBITT & A. RANDOLPH. GOVERNOR FOR STEAM ENGINES. No. 485,083. Patented Aug, 26, 1890.

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S. S. BABBITT & A. RANDOLPH.

GOVERNOR FOR STEAM ENGINES.

No. 435,083. Patented Aug. 26, 1890.

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SEWARD S. BABBITT, OF ALLEGHENY, AND ALFRED RANDOLPH, OF PITTS- BURG, ASSIGNORS TO SAID BABBITT, AND THE ROBINSON-REA MANU- FACTURIN G COMPANY, OF PITTSBURG, PENNSYLVANIA.

GOVERNOR FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 435,083, dated August 26, 1890. Application filedAug'ust 16,1889. Serial No. 320,988. (No model.)

To all whom it may concern:

Be it known that we, SEWARD S. BABBITT, of Allegheny, and ALFRED RANDOLPH, of Pittsburg, both in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Governors for Steam-Engines, of which the following is a full, clear, and exact description.

Our improved governor consists, essentially, of a balance-wheel keyed or otherwise secured concentrically to a shaft of the engine, the rotation of which corresponds with the speed of the engine; a ring which rotates with the balance-wheel, and on which is placed the yoke of the cam-rod, connected with the steamvalve of the engine, said ring being vibratory, so that its center shall either nearly correspond with or vary more or less from the center of motion of the balance-wheel, thereby giving greater or less eccentricity of motion and more or less stroke to the valve-rod connected therewith, and weighted levers attached to the balance-wheel, which shift the center of the ring relatively to the center of the shaft and balance-wheel, being actuated by the greater or less centrifugal force of the weights, depending on the increased or diminished speed of the engine.

Our invention is illustrated by the accompanying drawings, in which Figure l isaplan View of our governor. Fig. 2 is a sectional view in the plane of the line 00 a: parallel to the axis of rotation. Fig. 3 is a diagrammatic representation of the governor corresponding with Fig. 1. Fig. at is a diagrammatic representation illustrating a different arrangement of the pivotal points of the arms which are operated by the weighted levers. Fig. 5 illustrates a modified construction of the eccentric-ring and counterbalance. Fig. 6 is a side view of 5.

Similar symbols of reference are used in each of the figures.

A balance-wheel (consisting of a hub A, radial arms or spokes B, and a rim 0) constitutes the main frame-work of the governor, to which the other parts are attached or connected. V

D represents the central bore of the hub of the balance-Wheel, through which passes the shaft to which it is keyed, and a represents the center of the shaft and the fixed center of motion of the balance-wheel.

E is the governor-ring, F the eccentric-rod, and F its yoke, (shown by dotted lines in Fig. 1,) which yoke surrounds the governorring, so that the motion of the eccentric-rod is regulated by the varying distance between the respective centers of the hub A and ring E. With this construction it is evident that if the center 6 of the governor-ring E were to coincide exactly with the center of motion a of the balance-wheel the ring E would have no eccentricity of motion and the governor-rod F would remain stationary. As a matter of fact, however, this never occurs; but these centers most nearly coincide when the governor-ring E is shifted over, as hereinafter described, until its center 6 is at the point e, slightly to one side of the center of motion a of the balance-wheel, (see Fig. 1,) so that there is in fact always a slight motion of the eccentric-rod F, the motion of the eccentric rod being caused by the revolution of the governor-ring E with the balance-wheel A when the center of the former is placed eccentrically to that of the latter. How this eccentricity is regulated in exact relation to the speed of the engine we will now proceed to explain. The governor-ring E has a projection H from one side, which serves as a counter-balance to the ring and assists by its gravity the action of the balance-wheel. The governor-ring is pivoted at h to the balancewheel, either to one of its spokes or to a web 1) between two spokes, for thatpurpose. The point h is sufficiently distant from the center e of the ring to give the requisitedegree of cocentricity, (between points 6 and 6'.) Thus the center of the ring E is capable of a vibratory motion from c to c or from c to soon either side of the center a of the balancewheel A, and as the position of the ring E relatively to the center of motion a of the wheel A varies, so does the eccentricity of the cam-ring E vary, and the consequent motion of the governor-rod F.

To two of the spokes B of the balancewheel A, at diametrically-opposite points i z", are pivoted the bent levers J J, the pivots being preferably knife-edges, so as to secure the greatest ease of motion with a minimum of friction. Each of these levers J J has rigidly (or adjustably) attached to it a weight W W, the gravity of which is sufficient to operate the levers by the centrifugal motion of the weights on the rotation of the wheel, but not so great as to put an undue strain on the wheel. The size of the parts should be regulated to suit the size and required speed of the engine. The lever J is a lever of the first order, having a short arm j extending beyond its fulcrum 2', while the lever J is a;

lever of the second order, its fulcrum vi being at the outer end of the short arm, as shown in Fig. 1.

To the end of' the short arm j of the lever J, at k, is pivoted a link L,connectingthe point at the outer end of the short arm with the ring E at a point 2 near to its circumference and midway between the center 6 of the ring E and the pivotal point 71. on the counterbalance H. A correspondinglink L connects the point 70 at theinner end of the short arm 7' of the lever J with the same point .2 at which both links L L are pivoted to the ring E.- The long arms of the levers J J extend in the same direction, (relatively to the motion of the balance-wheel,) as shown in Fig. 1. With this arrangement as the increased speed of the engine causes an increase of speed of rotation of the balance-wheel on its axial center a the weights W W move outward toward the circumference of the wheel actuated by the increasing centrifugal force, and as they so move they both push the links L L in the same direction indicated by arrows in Fig. 1. This has the effect of shifting the governor-ring E from the position shown in Fig. 1 until the center of the ring approaches the point e near to the point a thecenter of rotation of the balance-wheel and, as before explained, this shifting of the ring E causes it to operate as an eccentric on the eccentric-rod F, because its center of rotation (which is always at a) coincident with that of the balance-wheel is no longer coincident with the center of the ring itself.

In order to limit the range of motion of the weighted levers J J in either direction,buffers or stops N N are placed on the spokes of the balance-wheel, and the long arm of the levers is extended beyond the weights WV IV, so as to engage those stops at the extreme points of their throw.

In order to moderate the centrifugal action of the weights and to give the lever-arms a centripetal tendency when the speed of rotation of the balance-Wheel diminishes, and also to enable the centrifugal force to be regulated, we connect each lever J and'J with the hub A of the balance-wheel by a coiled spring S S, as shown in Fig. 1, so that the centrifugal force of the revolving weights W W has to overcome the contractile force of the springs S S before the lever-arms move outward1y.- The inherent contractile force of'the springs themselves may be regulated by means of a tension-screw in the usual way. These spiral springs are arranged as nearly as possible on the same diametrical line of the balance- Wheel, so as to avoid the element of uncertainty of action which might arise from the weight of the springs themselves.

When it is desired to adjust the apparatus to an engine running in the opposite direction to that indicated by arrow 1 in Fig. 1, it is done by causing the weighted levers J J to exchange places and turning them over, so that the position of the weights shall be reversed, for which. the extra buifers N N N N are provided. When this change has been effected and the balance-wheel and its shaft revolve in the direction of arrow 2, Fig. 1, the range of vibration of the center of the governor-ring E will be from point e to point 00, instead of from point e to point e, as before. It is obvious that these changes will throw the counter-balance H out of adjustment, to rectify which we provide a shifting weight Q on the rim of the balance-wheel, which'is moved, as indicated by dotted lines, until the rim of the wheel A is balanced, when the counter-poise H is in the middle point of the vibration of the ring E.

In place of the shifting of the weight Q, the same result may be obtained by the construction of the counter-balance and cam-ring, (shown in Figs. 5 and 6,) in which the counterbalance H is secured to tho cam-ring E by means of a sleeve r and setscrew s, and thus when the relative position of the weighted levers J and J is reversed, as just described, and the range of vibration of the ring E is changed, (from c to x,instead of from c to e,) the position of the counter-balance H may be shifted sufficiently to compensate for the change of vibration of the governor-ring E, so that its vibrations may be of equal range on IIO either side of a radial line passing through the center of the balance-wheel.

In order still further to adapt our governor to a change of direction of the running of the engine, we provide two pivot-holes y y for the attachment of the links L L to the ring E, as shown in Fig. 4, so that the pivotal point of the links may be changed, so as to bring it in a right line between the point h of vibration of the ring E and the center of the ring when the weights WV W are nearest to the center of the wheel, which secures the maximum of power to the levers.

In order to secure uniformity of leverage, and thus an invariable character of force applied to the eccentric-rod, we adjust the parts so that the length of the short arms 9' j of the levers J J, the distance between the pivotal point h of the counter-balance H and the point z (y or y) of the links L L on the ring E, and the distance between the shall all be equal to each other. By this means when the weight WV on the lever J moves outward by centrifugal force to or toward the position shown by dotted lines in Fig. 3 the leverage of lever J (and consequently the power applied to shift the governor-ring E on its pivot h) correspondingly increases; but this increase is compensated for by the increased leverage of the ring E, which, turning 011 its pivot h, moves the point 6 toward the point e.

We have described our device as constructed with two weighted levers and retractile springs; but it might be operated with one weighted lever and spring; but in that case it would be difficult to counterbalance the weight, as it is constantly changing its distance from the center of motion.

Our governor constructed as described may, if desired, be inclosed in a suitable case. It is not necessary that the shaft of the engine to which it is applied should actually pass through the hub A of the balauce-wheel, as our governor would operate in the same manner if properly centered on the end of a re volvin g shaft.

That we claim as our invention, and desire to secure by Letters Patent, is

1. As a governor for steam-engines, a balance-wheel arranged to have its center of motion coincident with that of a rotatable shaft of an engine, a vibrating governor-ring attached to the balance-wheel so as to rotate therewith by a pivotal connection at a point eccentric both to the ring and shaft, and one or more weighted levers attached by pivotal connection to the balance-wheel so as to revolve therewith and also to operate by the centrifugal force of the revolving weight or weights, with a radially-arranged spring or springs to give a counteracting centripetal motion, such lever or levers being connected with the vibrating ring so as to shift its center toward or away from its center of motion, and an eccentric-rod connected with and operated by .the vibration of the governor-ring, substantially as and for the purpose described.

2. The combination of the balance-wheel consisting of the hub and. spokes B and rim C, governor-ring E, pivoted eccentrically to the balance -wheel, with a counter-balance H, weighted lever or levers J, stops or buffers N, retractile springs or spring S, extending radially from the shaft, and links or link L, connecting the ring E from a point outside of its pivotal point to the weighted levers or lever, arranged and operating substantially as described.

3. In a governor such as described, having a balance-wheel, a governor-ring pivoted thereto at a point outside of its center of r0- tation, weighted levers and links connecting the cam-ring with the weighted levers at a point intermediate between the center of rotation and the center of vibration of the camring, making the length of the short arms of the levers equal to each other and also equal to the distances between the center of revolution of the cam-ring and the point of attachment of the links which connect it with the levers and between said point of attachment and the center of vibration of the ring, and radially-arranged springs connecting the weighted levers with the hub of the balancewheel, substantially as and for the purpose described.

4. In a governorsuch as described,the combination,with abalance-wheelAandweightedlevers J, of the vibrating and revolving cam-ring E, having its center of vibration on said wheel outside of its center of rotation and the point of attachment to the links which connectthe ring with the weighted levers in a right line between its actual center and its center of vibration and equidistant from each, and radially-arrangedsprings connectingthe weighted levers with the hub of the balance-wheel, substantially as and for the purpose described. In testimony whereof we have hereunto set our hands this 9th day of July, A. D. 1889.

' SEWARD S. BABBITT.

ALFRED RANDOLPH. lVitnesses:

W. B. CORWIN, H. L. GILL.

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