US492254A - Governor for steam-engines - Google Patents

Description

(No Model.) v 2 Sheets-Sheet l. R. ALLISON.

V GOVERNOR PoR STEAM BNGlNBs. No. 492,254. `Patented Feb. 21, 1893.

(No Model.) v2 sheetsQsheet 2.

R. ALLISON. GOVERNOR POR STEAM ENOlNEs.

VNO. 192;254. Patented Feb. 21, 1893.

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UNiTED STATES PATENT OEETCE.

ROBERT ALLISON, OF PORT CARBON, PENNSYLVANIA.

GOVERNOR FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 492,254, dated February 21, 1893.

Applicatie nea compe 4, 1892.

To all whom, it may concern: l

Be it known that I, ROBERT ALLIsoN, a citizen of the United States, and a resident of Port Carbon, Schuylkill county, Pennsylvania, have invented certain Improvements in Automatic Governors for Steam-Engines, of which the following is a specication.

My invention consists of certain improvements in that class of automatic steam engine governors which rotate with the crank shaft or other rotating part of the engine andserve to vary the throw of the'steam inlet valve or valves and thus regulate the cut oft of the engine so as to supply the same with the proper amount of steam to perform the work required, one object of my invention being to so construct such a governor that it will be extremely sensitive and accurate in operation and will thus insure substantially uniform and regular speed of the engine, and a further object being to permit of a large range of adjustment to meet the varying conditions and speeds. These objects I attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in which- Figure l, is a front View of my improved governor, part of the same being broken away to illustrate parts which would otherwise be covered; Fig. 2, is a'longitudinal section on the line 1-2, FiO. l; Figs. 3, 4 and 5, are detached views of parts of the device; and Fig. 6, is a diagram illustrating the operation of part of the governor.

A represents part of the main shaft of the engine, B part of a iiy wheel or disk thereon, and D a plate or bar mounted on said wheel or disk, and capable of adjustment thereon by swinging it to a limited extent around the axis of the shaft A the securing bolts a for said plate D being adapted to segmental slots a at the ends of the plate as shown in Fig. l. While this construction is preferred, for reasons set forth hereinafter, the use of the plat-e D is not, in all cases, absolutely essential to the proper carrying out of my invention, as the parts carried by said plate may, in some cases, be mounted directly upon the wheel or disk B if desired. y

Hung upon the reduced end of the shaft A is a lever F which may be termed an adjuster lever, the central portion or hub of the plate D being cut away or recessed as shown in Serial No. 447,782. (No model.)

Fig. l to permit proper play of the opposite arms of said lever. Projecting from the face of this lever is a pin b upon which is mounted, so as to be free to turn thereon, a block b', which is fitted between arms d depending from a sliding bar G which may be termed an adj uster slide, this slide being guidedin suitable slots in the central portion of the hub of the plate D and being retained in position laterally by a suitable cover plate f but being free to move transversely to the axis of the shaft A under the influence of the adjuster lever F, sudden movement of the adjuster slide in either direction, however, being prevented, owing to the fact that each end of said slide is provided with a stem g which has an enlarged head g working--in a cylinder I-I hung by means of a pivot stem h to the plate D, these cylinders being filled wit-h oil or other liquid so as to act as dash pots or retarding cylinders, it being understood that the pistons formed by the heads g do not fit so snugly in the cylinders as to prevent the flow of oil or other liquid from one end of the cylinder to the other around said pistons.

Hung to studst' on the plate D are two governing levers J and K, one arm of each of these levers carrying an adjustable weight J which can be secured in any desired position on the arm by means of a set screw 7c and jam nuts 7e', the other arm of each lever carrying an adjustable sleeve M which may also be secured in position after adjustment by anysuitable means, as for instance by means of a set screw, as shown in Fig. 1. A spring N is attached at one end to the weight J of thelever J and at the other end to the sleeve M of the lever K and a like spring Nis attached at one end to the weightJ of the lever K and at the opposite end to the sleeve M of the lever J, the connection in each case being effected by means of a screw stem m hung by means of a pivot pin m to the sleeve or weight, this screw stem being adapted to a nut??J which receives or is secured to the end coils of the spring, as shown in Fig. 5. One of the screw stems m of each spring has a right hand thread, and the other a left hand thread, hence, when jam nuts n beyond the nuts n are slackened, thexteusion of the spring can be readily varied by turning it in one direction or the other, movement in one direction having a tendency to stretch the spring and increase its tension, and movement in the opposite direction having the effect of slackening the spring and decreasing its tension. The weight J of the lever J is connected by a rod 'p to one arm of the adjuster lever F, the other arm of said lever being connected bya similar rod p to the weightI J of the lever K.

On the face of the adjuster slide G is a pin W which projects through a suitable elongated opening in the cover plate f and is adapted for the reception of the rod which is connected to the valve operatin g stem or slide of the engine in the usua-l manner.

It will be observed that the point of connection ot' the spring N to the sleeve M of each of the governing levers is closer to the fulcrum i of said lever than the point of connection of the other springN to the weightJ of said lever, hence each of the governing levers is, in effect, a differential lever and when the governor is in action the centrifugal force has a tendency to cause the weighted arms of the levers to move outward or in the direction of the arrows, Fig. l.

When the engine is running at its proper speed, the weighted levers J and K are practically stationary and the pin fw of the adj uster slide G occupies its normal relation to the axis of rotation of the governor. Any increase or decrease of the speed of the engine, however, will cause movement of the levers yJ and K, in one direction or the other, and

such movement will be imparted to the adjuster lever F and thence to the adjuster slide G so as to vary the position of the wrist pin in respect to the axis of rotatiomand thereby increase or diminish the throw of the valve to regulate the cut off, increase in the speed of rotation above the normal causing movement in one direction so as to restrict the supply of steam to the cylinder, while a decrease in speed below the normal causes movement in the opposite direction,and an increasein the supply of steam to the cylinder. The governing levers J and K are quickly responsive to any change in speed of the shaft A so that the practical effect of the governor is to maintain said speed substantially uniform by supplying the engine with just the amount of steam necessary to maintain such uniform speed under varying conditions of load.

Exceedingly line variations in the movement of` the valve and correspondingly close regulation of the engine are provided for by reason of the fact that the wrist pin w is adjusted in a direction transversely across the end of the shaft A and in a plane which does not intersect the center of the said shaft so that the change in the distance of the pin radially from the axis of rotation is much less than the actual transverse movement imparted'toit. This will be understood on reference to the diagram Fig. 6,in which the segmental lines represent the difference in radial adjustment 01 throw of the Wrist pin which will result from the much greater transverse movement of the pin represented by the vertical lines y y.

In setting the valves in the first instance the lead of the same may be increased or diminished to suit any ordinary changes in conditions by swinging the plate D on the wheel or disk B and the tension of the springs can be readily varied in the manner before set forth, while the power of the levers J and K can be regulated by varying the relative lengths of their long and short arms by proper adjustment of the weights J and sleeves M, these various adjustments giving a range which will be amply sufficient to cover any conditions which may arise in practice.

Although I prefer in all cases tov use the construction of differential levers and double springs shown and described, some'of the fea-- tures of my invention may be used in connection with a `governor in which but a singlegoverning levers and their Weights,.with' a pair of springs each acting upon one arm of one lever and upon the opposite arm of the other lever, substantially as specitied.

2. The combination in an automatic governor for steamV engines, of the differential governing levers each havingl anadjustable Weight on one arm and an adjustable sleeve on the other arm, and a pair of springs each connected at one end to the Weight of onclever and at the other end to the adjustable sleeve of the other lever, substantially as specilied.

3. The combination in an automatic governor for steam engines, of the rotating governor shaft,an adjuster lever free to turn on the axis of said shaft, an adjuster slide guided transversely across the end of the shaft and carrying the Wrist pin for the valve rod, and a sliding connection between the adjuster lever and slide, 'whereby rocking movement of the lever is caused to move theslide to and fro, substantially as specified.

4. The combination of the rotating shaft, the adjuster lever, the adjuster slide engaging therewith and having a Wrist pin for the valve rod, and. pistons connected to said ad'- juster slide and adapted to cylinders rotating with the governor and filled with liquid soas to serve as retarders for the slide, substantially as specified.

5. The combination of the governorshaft and its Wheel or disk, aplate mounted on said wheel or disk and adjustable around the axis IOO IIO

of rotation of the same, an adjuster lever In testimony whereof I have signed my likewise movable around saidI axis of rotaname to this specification in the presence of tien, an adjuster slide engaging with said letwo subscribing Witnesses.

ver and. carrying the Wrist pin of the Valve ROBERT ALLISON. 5 operating rod, and spring controlled Weights Witnesses:

hung to the plate and connected to said ad- D. H. SEIBERT,

juster lever, substantially as specified. CEAS. T. BROWN.

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