Improvement in link-motions for operating valves
US 42297 A
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Description (OCR text may contain errors)
VILLARD KNOVVLES, OF BOSTON, MASSACHUSETTS.
IMPROVEMENT iN LINK-MOTIONS FOR OPERATING VALVES.
Specilieation forming part of Letters Patent No. 4l 2,297, dated April 12, 1864.
To all whom t may concern:
Be it known that 1,W1LLARD KNoWLEs, a resident of Boston, in the county ot' Suffolk and State ot' Massachusetts, have invented an Improved Link Motion or Mechanism for the Valve of a Steam-Engine; and I do hereby declare the same to be fully described in the following specification and represented in the accompanying drawings, ot which- Figure l is a top view, and Fig. 2 a front elevation, of it.
My improvement is to be found in the peeuliar connection of the link with its operative lever-viz., by means of an are anda swing-block, or its equivalent.
The advantage of my improv( d. connection over the common rod connection is that the former presents the wear ot' the sides of the link that results from the latter, the strain of which on the link tends to cant the link on the pin of the valve-lever, and so as to wear the link on its opposite sides, the same rendering it necessary to plane down the link in order to repair it. This reduction ot' the thickness of the linkdiminishes its strength and durability, and, besides, is objectionable in other respects. With my invention the link during its motions is always maintained in a vertical or one plane.
In the drawings, c represents the valvelever, which is connected With the open curved link b by means cfa pin, c, applied to the two in the usual manner. The two eccentric-rods d e are jointed to the said link and applied to the eccentricsfg. The lever for raising and depressing` the link is shown at h, it being connected to the link by the swing-block t' and the circular are It. The said arc 7c is joined to the upper end of the link, and is clasped by the swing-block in manner as exhibited in Fig. 3, which is a vertical section of the two, and also represents the pin l, by which the swing-block is connected With the lever h. This pin passes through the swingblock, and is xed in the lever, the said block being capable ot' turning or revolving on the pin. Each end ofthe link will receive motion from the eccentric-rod next adjacent to it,what ever may be the extent of' elevation of the link or the middle part of it. It is also evident that the valve-lever will be moved the more by that eccentric-rod which may be the nearer to its connecting-pin. When the link may be depressed to a low position, the valve-lever will acquire the motion ot' the upper eccentricrod, which is that properrfor going ahead. When raised up into a high position, the valverod will acquire the motion ofthe other eccentric-rod, or that for reversing the engine, while, when the connection pin of the valvelever is at the center of the link, such lever will have little or no motion imparted to it.
The link motion or mechanism obviates the necessity ot' throwing the eccentric-rod out of gear, and also enables the en gine to be worked to al certain extent expansively.
During the movements ot the link caused by the eccentric-rods the curved are la will be moved longitudinally through the swing-block yi, which will swing or play on itspin l without causing any material movement of the lever lt. The are and the swing-block thus serve to preserve the connection of the lever with the link, and allow of the necessary movements ot' the latter. The longer arm ot' the lever h is represented in Fig. 2 by dotted lines, such arm being that which the engineer takes hold ot' in order to so move theV lever as to either raise or depress the link.
.In the said link-motion, I claim-` The connection of the link with its operative lever, the same Ibeing by means of the curved are k and the swing-block t' or its equivalent.
NV ILLARD KNOW LES.
R. H. EDDY, F. P. HALE, Jr.