US2431619A - Steam engine with keyed connection between piston rod and crosshead - Google Patents

Description

E. C. READ Nov. 25, 1947..

STEAM ENGINE WITH KEYED CONNECTION BETWEEN PISTON ROD -AND CROSSHEAD Original Filed Feb. 3, 1937 3 Sheets-Sheet r/V/ f INVENTOR.

" EVE/76317 Elfin ATTORNEY E. C. READ Nov. 25, 1947.

STEAM ENGINE WITH KEYED CONNECTION BETWEEN PISTON ROD AND- CROSSHEAD 3 Sheets-Sheet 2 I Original Filed Feb. 3, 1957 INVENTOR. EVERETT 6'. H3191).

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E. C. READ Nov; 25, 1 947.

STEAM ENGINE WITH KEYED CONNECTION BETWEEN PISTON ROD AND CROSSHEAD Original Filed Feb. 5; 1937 5 Sheets-Sheet 3 I INVENTOR.

EVERETT 6'. E5790 Kg; w VJ/Wk 19 TTOENES Patented Nov. 25, 1947 STEAM ENGINE WITH KEYED CONNECTION BETWEEN PISTON ROD AND CROSSHEAD Everett 0. Read, Milwaukee, Wis, assignor to The Filer & Stowell 00., Milwaukee, W1s., a corporation of Wisconsin Original application February 3 1937, Serial No. 123,789, now Patent No. 2,300,747, dated 1210;- vember 3, 1942. Divided and this application June 3, 1942, Serial No. 445,619

3 Claims.

This invention relates to an improvement in steam engines. The present application is a division of my application for improvements in Steam engines, filed February 3, 1937, Serial No. 123,789, new Patent No. 2,300,747.

One of the objects olfthe present invention is to provide a novel and advantageous means of connecting the piston rod of the engine to the cross head thereof; which, while facilitating assembly and disassembly; also performs the function of locating or centering the piston in proper position longitudinally of the cylinder so that there will be the same Volume at both ends of the cylinder at both ends of the stroke of the piston. The same means also locates the piston rod and its piston in proper angular position in the cylinder so that the piston rings of the piston, which are doweled in position, will always be maintained with their splits or gaps in vertical alinement with the bridges or unbroken structure of the cylinder wall extending between the exhaust ports thereof.

Another object of the invention is to provide a steam engine wherein the piston is positively guided in such manner that there is clearance between the peripheral portion of the piston heads and the cylinder; the piston rings only engaging the cylinder, thereby reducing wear on the cylinder and avoiding any liability of the cylinder being worn out of round. These advantages are had in the construction which is simple and compact, durable, and efficient, which may be advantageously embodied in a doubleacting type of engine; and which may be easily and readily assembled and disassembled.

Another object of the invention is to provide a steam engine of this character having novel and advantageous means for interconnecting its cross head and connecting rod, one wherein the advantages of a double-oil film are realized, wear is decreased, and the wrist pin and bushing embodied in said connection stay round.

Other objects and advantages reside in oertain novel features of the construction, arrangement, and combination of parts which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the accompanying drawings forming a part of this specification, and in which:

Figure l is a fragmentary view in central, vertical, longitudinal section, showing a steam engine incorporating in its construction the novel features of the present invention, parts being 2 shown in elevation for the sake of simplicity in illustration;

Figure 2 is a fragmentary sectional view on an enlarged scale, showing the combined stufiing box and guide at the lower end of the cylinder and associated parts;

Figure 3 is a fragmentary view partly in side elevation and partly in diametrical, vertical cross section showing the novel form of releasable connection and locating means employed between the lower end of the piston rod of the steam engine and the cross head thereof;

Figures 4-, 5, and '6 are detail views in top plan, side elevation, and bottom plan, respectively, of the double key and locating or distance block embodied in the structure illustrated in Figure 3;

Figure 7 is a detail perspective view of the spacer employed between the lower end of the cylinder and crank case;

Figure 8 is a fragmentary View in vertical cross section illustrating a portion of the piston head traversing the exhaust ports of the cylinder, the View being taken on line 8-8 of Figure 9;

Figure 9 is a view in horizontal cros section taken on line 9-9 of Figure 8;

Figure 10 is a fragmentary view in vertical cross section taken on line Ill-40 of Figure 9; and

Figure 11 is a fragmentary View in elevation illustrating a portion of the piston structure and one of the dowel pins employed for the purpose of constraining the piston ring against rotation.

Referring to the drawings, and more particularly to Figure 1, the steam engine there shown comprises a frame or crank case designated at F, above which the cylinder C of the engine is supported in a manner which will be hereinafter more fully described. A piston P is reciprocable in the cylinder C and has a piston rod R projecting down through a combined stufiing box and guide A and connected to a cross head H which slides in a cross head guide G "supported on the crank case or frame F of the engine. A connect ing rod C connects the cross head H with the crank shaft (not shownlof the engine. The cylinder C is provided with a steam inlet I which communicates with the center of a valve chest E. At the upper and lower ends of the valve chest E liners L and L are provided. Upper and lower inlet valves V and V are slidably fitted in the liners L and L provided therefor in the valve chest and function respectively to control the supply of steam to the upper and lower ends of the cylinder 0. The steam exhausts from thecylinder through exhaust ports 0 under the conis surrounded by an outer casing 55 concentric with the center line of the cylinder and in spaced relation to the outer surface thereof, this outer casing 55 being supported at its lower end on a flange 56 provided at the upper end of the extension I! of the crank case. A cap or cover 51 is supported on the upper end of the casing 55 and is disposed in spaced relation to the sheathing 5%. At the center of the cap a baffle air discharge opening 58 is provided. The fitting which provides the baffle air discharge opening is suitably secured to the cap and is bolted or otherwise releasably secured to the upper end head 50 of the cylinder. The details of this construction form no part of the present invention save for the fact that they indicate certain essential general features of construction, namely the re movability of the cap 51, the sheathing 54, and the upper end head 50 of the engine.

The cylinder C is supported on and in spaced relation to the section l6 of the top of the crank case by means of a spacer 85, which, while it may be integral with the crank case, is preferably in the form of a separate casting having upper and lower projecting rings 86 and 85, which telescope and interconnect with the lower end of the cylinder C and with the flange I6 of a central opening of the top section 16 of the crank case, respectively.

The upper ring 86 is integral with the upper endportions of four tubular corner posts 81 embodied in the construction of the spacer 85, while the lower portions of these posts 81 form integral parts of the lower box-like section 88 of the spacer. The lower ring 86 is integral with the lower open end of the box-like section 88. The ends of the box-like section 88 are closed by means of integral end walls 88 but the sides thereof are equipped with removable cover plates 90 bolted over openings'or hand holes formed in the sides to provide for access to the interior thereof. A substantially horizontal wall or web 9| closes the upper end of the section 88 and is provided at its center with an oil scraper box 92 for the piston rod R. Bolts 93 releasably secure the box 92 to the topwall 91 of the lower section 88 of the spacer.

In the assembly suitable bolts (not shown) secure the cylinder C, spacer 85, and the crank case F together.

The releasable connection between the lower end of the piston rod R and the cross head I-I may comprise a collar 94 having an internally tapered and threaded opening or bore threadedly engaged with the corresponding lower end of the piston rod B so as to be efiectively fixed thereto (see Figure 3). The collar may be fixed in any other way to the piston rod, but the manner described is advantageous from the point of view of assembly. A sleeve nut 95 is loosely mounted on the rod R above the collar 94, and in the assembly has its external threads engaged with internal threads in a socket 95' provided in the upper end ofthe cross head H, the lower end of the nut 95 bearing down on the collar 94 in the assembly. A combined locating or distance block and double key 96 is interposed between the 4 bottom of the socket 515 in the cross head E. This combination distance block and double key 99 has upper and lower keys integral therewith and at right-angles to each other and interfitted in keyways provided therefor in the lower end of the piston rod R and in the bottom of the socket of the cross head, thereby insuring assembly of the piston rod and piston in proper angular relation. In this connection it will be understood that the piston rings P of the piston P are doweled in their grooves by dowel pins d and they are so arranged that when the piston P is properly positioned, the splits of each of the rings will be vertically alined with the bridges or unbroken structure of the cylinder wall extending between the exhaust ports 0 as illustrated inFigures 8, 9, 10, and 11. This element 96 insures proper positioning of the piston in the assembly. Moreover, the combination locating or distance block and key 96 is of such thickness as to properly and permanently position the piston rod R. longitudinally with respect to the cylinder so that when the piston is fixed in proper position on the piston rod, it will be properly centered longitudinally of the cylinder at both extreme positions so that at both ends of the stroke of the piston there will be the same volume at both ends of the cylinder. Hence, when the engine is, completely assembled and the adjustment of the clearance through the thickness of this combination key and locating or distance block has been made, it cannot be changed without changing the thickness of the element 96. Y

The combined stufiing box and guide A, through which the piston rod reciprocates, comprises a bushing H10 having a rabbeted flange llll at its upper end engageable in the assembly with a similarly formed seat provided around the inner margin of the opening in the lower end head of the cylinder. The interengaging surfaces of the flange I01 and its seat are a ground fit to insure a hermetic seal in, the assembly. Associated with the upper end ofthe bushing N30 is a sleeve-like guide H12 which has a flange 133 at its lower end engaged with an internal flange at the upper end of the bushing I80. Metallic packing I04 is provided below the guide sleeve I92 and is held in proper position by a follower B05 adjustably interconnected with the bushing in any suitable way. The bushing I00 projects downwardly beyond the lower end of the cylinder and its lower portion is externally threaded so as to be threadedly engaged with an internally threaded collar I06. There is a free running threaded engagement between the collar I06 and the bushing so that the collar I06 may be readily turned up on or backed off on the bushing. Lock screws l0! equipped with lock nuts I97 are threaded through the collar and bear against the lower cylinder head to firmly secure the bushing, packing and guide in position. By loosening the lock nuts and slightly backing off the screws I01 the collar may be readily spun off of the bushing to allow the bushing, packing and'g-uide to be pulled up through the cylinder without dismantling the packing or disturbing its adjustment.

With the construction of'the piston, cylinder and piston rod as described, these parts and their guides and glands may be readily removed fromv the top of the engine, after taking off the cover 51, the sheathing 54 containing insulation 52., by unbolting the upper end head 50, loosening the nuts NH and. the screw l0l',,backing off the collar I06, removing the plate 90 on spacer 85, disengaging the cap screws 93 and the sleeve nut 95, and pulling the whole assembly up out through the upper end of the engine.v

With the collar I06 removed from the bushing let, the combined stuifing box and guide A may pass readily upward through the opening in the lower end head. The fittings shown diagrammatically in Figure 1 and associated with the follower set for lubricating and draining the metallic packing HM are, of course, uncoupled. It will be noted that the metallic packing embodied in the combined stuffing box and guide A has its lower rings constituted to provide scrapers adapted to scrape off any moisture from the piston rod and any such moisture scraped off is' carried 01f by the draining fitting with which the follower of this stufilng box is equipped. The oil scraper box 92, as well as the sleeve nut 95 and its associated collar 94, also readily pass through the opening in the lower cylinder head.

Access to the nuts Edi, screws H31, and collar H35 and associated parts, is had by removing one of the cover plates 97 releasably secured by bolts 68 (see Figure 1) over openings or hand holes provided opposite these removable parts in both the front and rear sides of the crank case.

With the cover plate 91 removed, it is con venient to remove one of the cover plates Q13 to provide for access to the sleeve nut 85.

For connecting the connecting rod C to the cross head H the upper connecting rod bearing is provided with a floating bushing I26 in which a hollow floating wrist pin I2! is rotatably fitted. The wrist pin projects beyond the bushing IZil and its connecting rod bearing and its ends are rotatably mounted in bearings I22 provided therefor in the cross head. End discs or washers I23, engaged with the ends of the wrist pin and with shoulders 823 on the cross head and a bolt and nut 52 between the disc I23, hold the wrist pin against endwise movement.

The combined stuifing box and guide A and the cross head H and guides I25 and I26 constrain and guide the piston rod to reciprocatory movement along an ax s coaxial with the cylinder (3. Clearances are provided between the peripheries of the heads of the piston P and the wall of the cylinder 0, this being feasible because of the positive guiding of the piston rod R. to which the piston is fixed. Only the packing or piston rings P engage the wall of the cylinder. Wear on the cylinder is reduced and liability of the cylinder being worn out of round is avoided.

The cross head H comprises a steel body portion which supplies strength with lightness and a bronze facing cast on the steel body to supply the desirable wearing qualities and reduce the friction incident to its reciprocation in its guide.

By having a floating wrist pin and a floating bushing in the connection between the cross head H and the connecting rod the advantages of a. double oil film are realized, wear is decreased, and the wrist pin and bushing stay round.

While I have shown and described one construction in which the invention may be advantageously embodied, it is to be understood that the construction shown has been selected merely for the purpose of illustration or example, and that various changes in the size, shape, and arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subioined claims.

I claim:

1. An engine ofthe type including a cylinder having inlet and exhaust ports and having bridges between the exhaust ports, a piston reciprocable in the cylinder and traveling past the exhaust po-rts piston rings doweled to the piston and engageable with the walls of the cylinder, the splits of the rings being longitudinally aligned with the bridges of the exhaust ports when the piston and cylinder are assembled, a piston rod fixed to the piston and projecting beyond the cylinder and a cross head; means for connecting the piston rod to the cross head comprising a releasable fastening device for securing the outer end of the piston rod to the cross head and a combination key and distance block interposed between the outer end of the piston rod and the cross head, the outer end of the piston rod and the cross head having key ways with which said keys are interfitted, the key ways being positioned and the distance block being dimensioned to locate the piston rod and its piston in a predetermined position longitudinally and angularly with respect to the cylinder so that there will be the same volume at both ends of the cylinder at both limits of the stroke of the piston and so that the splits of the piston rings will be maintained in longitudinal alignment with the bridges of the exhaust ports of the cylinder.

2. In an engine of the type including a cylinder having inlet and exhaust ports and having bridges between the exhaust ports, a piston reciprocable in the cylinder and traveling past the exhaust ports, piston rings doweled to the piston and engageable with the walls of the cylinder, the splits of the rings being longitudinally aligned with the bridges of the exhaust ports when the piston and cylinder are assembled, a piston rod fixed to the piston and projecting beyond the cylinder and a cross head; means for connecting the piston rod to the cross head comprising a releasable fastening device for securing the outer end of the piston rod to the cross head, said cross head having a socket in which the outer end of the piston rod is received and in which it is secured by the releasable fastening device, the floor of the socket and the outer end of the piston rod having transversely extending key ways disposed at right angles to each other, a distance block interposed between the floor of the socket and the outer end of the piston rod, and keys fixed to the upper and lower faces of the distance block, disposed at right angles to each other and inter-fitted with said key ways, the distance block being dimensioned to locate the piston rod and piston in proper longitudinal position in the cylinder so that there will be the same volume at both ends of the cylinder at both limits of the stroke of the piston, the keys and key ways functioning to maintain the splits of the piston rings aligned with the bridges between the exhaust ports.

3. In an engine of the type including a cylinder having inlet and exhaust ports and having bridges between the exhaust ports, a piston reciprocable in the cylinder and traveling past the exhaust .ports, piston rings doweled to the piston and collar fixed to the outer end of the piston rod, a sleeve nut loosely mounted on the piston rod and engageable with the inner end of the collar, said cross head having a socket receiving the outer end of the piston rod and its collar, said sleeve nut being threadedly engaged with the socket and bearing down on the collar to secure the lower end of the piston rod to the cross head, and a distance block interposed between and flatly engaging the floor of the socket and the outer end of the piston rod, keys fixed to the upper and lower faces of the distance block and disposed at right angles to each other, the outer end of the piston rod and floor of the socket having key ways with which said keys are interfitted, the distance block being dimensioned to locate the piston rod and piston in proper longitudinal position in the cylinder so that there will be the same volume at both ends of the cylinder at both limits of the stroke of the piston, the keys and key ways functioning to maintain the splits of the piston rings aligned with the bridges between the exhaust ports of the cylinder.

EWERETT C. READ.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number UNITED STATES PATENTS Name Date Youngs May 9, 1905 McElvaney April 17, 1906 Dickinson Mar. 21, 1916 Thomson Apr. 11, 1916 Keys June 27, 1916 Raven May 15, 1923 Osborn May 29, 1923 Anderson Jan. 14, 1930 Gorr Apr. 8, 1930 Alley July 5, 1930 Knox Feb. 16, 1932 Morton Sept. 27, 1932 Melker Apr. 16, 1935 Shiner Aug. 27, 1935 Meyer Mar. 12, 1940 FOREIGN PATENTS Country Date Germany Dec. 11, 1933 Great Britain Oct. 17, 1924

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