US833164A

US833164A - Valve-gear.

Info

Publication number: US833164A
Application number: US24061705A
Authority: US
Inventors: Charles Hammen
Original assignee: Individual
Current assignee: Individual
Priority date: 1905-01-11
Filing date: 1905-01-11
Publication date: 1906-10-16
Anticipated expiration: 1923-10-16

Description

PATENTED 0CT. 16, 1906.

c. HAMMBN.

VALVE GEAR. APPLICATION FILED 3111211, 1905.

4 SHEETS-SHEET 1 A,4: Nomals FErERs ca., wAsHlNaroN, n, c.

No. 883,164. PATENTED OCT. 16, 1906. C. HAMMEN. VALVE GEAR.

APPLIOATION FILED JAN.11`, 1905.

TN: NoRRls Psrsws ca., wAsHlNcmN, n. c.

No. 833,164. PATBNTED 00T. 16, 1906.

o. HAMMEN.

VALVE GEAR. .APPLICATION FILED JAN.11, 1905. I

4 SHEETS-SHEET 3v PATENTED OCT. 16, 1906.

C. HAMMEN. VALVE GEAR. APPLIGATION Hmm JAN. 11, laos.

THE Namers Farias cu.. wAsmNcroN, D. r

. being of the piston type.

UNITED STATES PATENT oEEroE.

CHARLES HAMMEN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALFTO JOSEPH MOHR, OF CHICAGO, ILLINOIS.

VALVE-GEAR.

Patented Oct. 16, 1906.

Application filed January 11, 1905. Serial No. 240,617.

T0 LZZ Awhom) it may concern:

Be it known that I, CHARLES HAMMEN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Valve Gears for Fluid- Iressure Motors, of which the following is a specification.

This invention relates to valve-gears for Huid-pressure engines, having special application to engines of the marine and locomotive types, wherein the direction of motion of the engine is principally in one direction.

The invention yhas for its principal object to increase the efficiency of such engines, and this object is accomplished through the provision of an apparatus whereby the range of application of the link-motion as a variableexpansion gear is increased. The common way of using the link or other reversing valvegear of steam-engines to effect variable eX- pansion is objectionable when cutting off earlier than iive-eighths of the stroke on account of the premature release and compression resultant therefrom. I have found that by using two eccentric-pins in the link-block instead of but one and connecting these to two valves or sets of valves in the engine and providing the same with sufficient steam and exhaust lap, respectively, to effect simultaneous cut off and simultaneous release the release and compression can be delayed from eight to ten degrees as compared with the results obtained by the usual construction of a single connection to the valve or valves from the link-block, the magnitude of the delay in release and compression thus secured depending on the amount of separation of the link-block pin-centers.

The principle of my invention is capable of application to practically all the known types of valve systems and reversing-gears, and in the present application I have illustrated the same in connection with the wellknown Stephenson link and valve systems of the "V-valveI and piston types.

Referring to the drawings, Figure 1 is an elevational view, partly in section, of so much of the valve mechanism and reversinggear of a vertical steam-engine as is necessary to illustrate the principle and construction of my invention, the valve mechanism shown Fig. 2 is a vertical sectional view through the valve-chest shown in Fig. l in the plane of the inner group of valves. Fig. 3 is a view similar to Fig. 1, showing a V-valve mechanism and also illustrating a modification in the connections between the valve-stems and the eccentric-pins of the link-block designed to accommodate a relatively wide separation of the valve-stems. Fig. 4 is a vertical sectional view through the cylinder and valve-chest in a plane at right angles to the plane of Figs. 1 and 2, and more particularly illustrating the differential lap applied to the two sets of valves. Fig. 5 is a cross-sectional view on the line 5 5 of Fig. 4. Fig. 6 is a vertical sectional view on the line 6 6 of Fig. 8. Fig. 7 is a similar sectional view through the cylinder and valve-chest on the line 7 7 of Fig. 3.

Referring to Figs. 1, 2, 4, and 5 and describing first those parts which are common and well known in steam-engine construction, 10 and 11 designate, respectively, the forward and backing eccentrics, mounted on the crank-shaft in the usual manner and connected through eccentric-

straps

12 and 13 and

rods

14 and 15, respectively,'with the opposite ends of the link 16. This link is the Stephenson or shifting link supported upon the eccentric-rods 14 and l5 and shiftable to effect reversal and variation of stroke from the tumbling-shaft 21 by means of a pair of bars 17, connected thereto and adjustably secured at their outer ends to a block 1S, slidably mounted in a frame 19, carried on the free end of arm 20, keyed on the tumbling-shaft 21, said shaft having another arm 22, which is connected by a link 23 to the usual engineers reversing-lever. (Not shown.) Mounted upon and slidable relatively to the link 16 is a link-block 24. 25 designates an engine-cylinder, 26 a piston therein, and 27 the piston-rod, having the usual connections to the driving-shaft. (Not shown.) 28 represents the valve-chest, located alongside the cylinder and having the usual steam-pipe 29 and exhaust-pipe 30. In the valve-chest are two series or groups of piston-valves, the inner group of three valves (shown in Figs. 2 and 4) being designated by 31 and the outer group consisting of a pair of valves designated by 32. The opposite valve-bodies of the two groups, which lie in longitudinal alinement at opposite ends of the chest, respectively, are connected by rods 33 and 34, respectively, the

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. stickin01 series of rods 33 being interconnected within the valve-chest by a bar or key 35 or equivalent bridgework, so as to move in unison, and the pair of rods 34 being similarly connected by a bar or key 36. Valve-

stems

37 and 33, connected to the inner and outer groups of valves, respectively, extend through suitable stuffing-boxes in the lower end of the valvechest.

In the above-described valve mechanisms the three valves at each end of the inner group and the two valves at each end of the outer group work together to constitute, in effect, a single valve for the control of the motive fluid. While the piston type of valve is old. and well known in ractice and pose sesses both advantages andp disadvantages as compared with the D type of slide-valve, yet the employment of a plurality of pistonvalves 1n each group has the still further feature of increased linear extent of opening at the periods of admission and cut ofi", as compared with the single valve-body, and is also less liable to derangement, leakage, or

g, owing to inequality of contraction and expansion. One feature of my invention, therefore, resides in the type of valve construction shown and described, which is of course capable of general application and beneficial use in an engine employing any kind or type of valve-motion mechanism.

Considering now those features wherein the more important part of my invention resides, it will be observed that the link-block 24 carries a pair of

pins

39 and 40, (shown in full lines in Fig. 6 and in dotted lines in Figs. l and 3,) the centers of these ins being spaced apart through a considerab e interval longitudinally of the link-block. From the pin 39 there extends a connecting-rod 41 to a cross-head 42, slidably mounted in a guide 43, which cross-head is connected at its upper end to the lower end of the valve-stem 33. Similarly the link-block pin 40 is connected by connecting-rod 42 to thelower end of the valve-stem 37, a portion of said connectingrod being slidably mounted in a guide 43,

whereby the linlcblock itself is held against. movement relatively to the link, except when the latter is adjusted thereto for purposes of reversal or variation of stroke.

The position ofthe link and its operating devices, represented by full lines, is the forward or ahead position, and it will be observed that by reason of the fact that the link-block pin 39, to which is connected the outer series of valves 32, is nearer the driving end of the link than is the link-pin 40 connected to the valves 31, the former series of valves will have a travel greater than the latter and later with respect to the crank. Consequently if the valves of both sets had the same amount of outside lap the valves of the inner set, having the lesser travel and earlier motion, would cut off earlier than the valves of the outer set. In order to overcome this and cause both sets of valves to cut off simultaneously, I provide additional outside la on the outer set of valves, as more clear y indicated in Fig. 4. Similarly if both sets of valves had the same inside lap the inner set would release earlier than the outer set, and in order to produce a simultaneous release l add enough inside lap to the inner set of valves to effect such simultaneous release of both sets. This use of differential lap may be illustrated by an example giving concrete dimensions, as follows: Assume that the travel of the outer set of valves, having the greater and later motion, is six inches, and that with an outside la of one and one-half inches they will cut o at one hundred and twenty degrees or threefourths of stroke, and with inside edges line and line they will release and compress at one hundred and fifty degrees or fifteen-sixteenths of stroke. The travel of the second or inner set of valves driving from the pin 40, having the lesser and earlier motion with respect to the crankin, would be five and oneeighth inches, an having an outside lap of one and one-half inches they will cut off steam at one hundred and five degrees or five -eighths of stroke. Now in order to make the valves with the longer or six-inch travel cut ofl'l at five-eighths stroke, about nine-sixteenths outside lap would be added, making a total outside lap of two and onesixteenth inches. The valves having the lesser travel with inside edges line and line will release and compress at one hundred and forty-two and one-half degrees or nine-tenths of stroke. In order to make these valves release simultaneously with the other set of greater travel, approximately one-fourth inch inside lap must be added. With these dimensions and conditions when the linkblock travel is further reduced ory the link hooked up the valves would cut off together at .ninety degrees or one-half of stroke and release at one hundred and forty-two and one-half degrees or nine-tenths of stroke simultaneously. With this arrangement there follows steam lead or preadmission with only one set of valves, the second set opening for steam when the crank has passed the deadpoint about fifteen degrees or onesixtieth of the stroke. At this point the iston has not attained any considerable ve ocity, so that the opening from one set of valves is ample, and the delayed o ening of the second set is not objectiona le. The cut-off, as above stated, is simultaneous with both sets of valves when running righthanded or forward, and release is likewise so, which is very essential in a good valve-gear. Compression is timed by the valves having the vgreater travel alone, which is no objection practically. With this arrangement steamdistribution in thel left-hand or'backing mo- TOO lIO

tion is not quite as perfect as in the righthanded or forward motion, but is ample for practical purposes in all engines, such as marine and locomotive engines, wherein the amount of work required Of the engine in the backing motion is practically negligible so far as questions oi economy are concerned.

Figs. 3, and 7 show the invention embodied in a valve mechanism of the Ordinary D type. In this oase a pair of D-valves are employed, located side by side and Operating over a common valve-seat. Referring to these figures, 44 designates the valve-seat, provided with the usual inlet- Orts 45, leading to Opposite ends of the cy inder, and the intermediate exhaust-port 46. In this valveseat are slidably mounted side by side a pair of D-valves 47 and 4S, respectively. These valves are shown side by side in Fig. 3and separately in Figs. 6 and 7. The valve 47 has a stem 49 extending through a suitable stuffing-box in the lower end of the valvechest, such stem having a loose sliding-block connection with one end of the free crosshead 50, tO the Opposite end of which is simi-y the connecting-rod 53 being similarly connected at its lower end to the pin 39. By this mechanism a change of the motion of the diiierent valves similar in character to that eHected by the apparatus already described is effected, such mechanism further permitting a wider separation of the valve-stems and a less separation of the link-block pincenters. As will be observed by a comparison of the two

valves

47 and 48, as shown in Figs. 3, 6, and 7, the valve 48,'having the greater travel and later motion, is provided with additional outside lap relatively to its companion valve in order to eect simultaneous cut oil when the engine is running in forward or ahead direction, while similarly the valve 47, having the lesser travel and earlier motion, is provided with a slight additional inside lap in order to delay release and effect the later operation simultaneously with the valve 48.

It is evident that the free cross-head connection last described might be employed in connection with two groups of piston-valves, and also that the latter might be substituted for the D-valves of Fig. 3, if desired, with the same beneiicial results.

I claim- 1. In a fluid-pressure motor, the combination with a cylinder and valve-chest havin a pair of independently-movable valves, O a reversing-gear including a rocking lever and a block slidable relatively thereto, and valveactuating rods connected to said block at separated points longitudinally thereon.

2. In a fluid-pressure motor, the combination with a cylinder and valve-chest having a pair of independently-movable valves, of a reversing-gear including a link and link-block slidable relatively thereto, the latter having two different pivots separated in the direction of motion of the block relatively to the link, and connections from said pivots to said valves.

3. In a fluid-pressure motor, the combination with a cylinder and valve-chest and a reversing-gear including a rocking lever and a block slidable relatively thereto, of a pair of independently-movable groups of pistonvalves in said valve-chest, each group comprising a plurality of connected and similarly operating valves, and independent connections from said groups of valves to separated points Onsaid block.

4. In a Huid-pressure motor, the combination with a cylinder and valve-chest, of independently-movable valves or sets of valves each having admission and exhaust functions and provided with different amounts of steam and exhaust laps, and means for imparting to said valves independent time motions.

5. In a fluid-pressure motor, the combination with a cylinder and valve-chest, of independently-movable valves or sets of valves each having admission and uexhaust functions and provided with `diiierent amounts of steam and exhaust laps, a link, link-block, and valve-actuating means connected to said link-block at longitudinally-separated points thereon.

CHARLES IIAMMEN.

Witnesses:

SAMUEL N. POND, FREDERICK C. GOODWIN.

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