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Title: |
1890 Article-Rollins Engine Co., Automatic Cut-Off Steam Engine |
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Source: |
The Steam User 1890 pg 60 |
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Insert Date: |
4/17/2011 9:12:45 PM |
The Rollins engine, while it bears some resemblance to the Corliss in its general make-up, is entirely dissimilar, in many essential particulars, in respect to the adjustment of its valves.
The bed piece is of the Corliss type, securely bolted to the pillow block and cylinder, and has V-shaped slides. The cross-head has two Babbitt-lined gibs, which are adjusted by double wedges sliding lengthwise of the gib, and are operated by screws.
The steam valves receive motion from an eccentric on the main shaft, through a rocker arm fixed near the centre of the frame, and a wrist-plate fitted to a shaft operating across the bottom of the cylinder, upon the other side of which, and upon the same shaft, is a rocker arm from which the exhaust valves receive motion.
The adjustment is such that the exhaust valves are opened rapidly, and are nearly at rest when closed.
Each valve is entirely independent of the other in actuation and adjustment, and any desired degree of compression or lead is readily and conveniently obtained.
The valves have but little pressure upon them, and are therefore very light in their movements upon the gear. There are but few frictional parts to the governor, and the small range of variation given to the balls admits but a slight variation.
The tripping device is adjusted to such a degree of nicety that the slightest touch liberates the cut-off valves. They are then closed instantly, and without the slightest shock to the governor.
This engine is of the four-valve liberating valve-gear type, and designed to fully supply the requirements of modern engineering science.
It is designed to work under a high steam pressure, and at the moderate speed of 450 feet of piston travel per minute, or a high speed of 700 feet.
The bearings are of liberal size, and are fitted with the latest and most improved oiling devices for continuous work.
The governor is constructed on scientific principles, and controls the engine perfectly, giving a uniform speed with varying load and pressure.
The working parts are constructed so as to take up the wear, and with a view to stability and minimum amount of repairs.
The movements are all easy and graceful, and all parts are accessible for adjustment. Actual tests of this engine—non-condensing with average of power and coal consumption for a long time—shows 2 ½ H. P. per hour. (Rollins Engine Co., Nashua, N. H., Sole Manufacturers.) |
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1890 Rollins Engine Co., Automatic Cut-Off Steam Engine
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