US2404315A - Reciprocating engine - Google Patents

Description

3 1946. 1.. c. ROTTER ET AL RECIPROCATING ENGINE Original Filed 001;. 4, 1945' I 5 Sheets-Shet l FIG. 3.

July 1946 TTER ET l. 2,404,315 I REQIPROCATING ENGINE 3 Shets-Sheet 2 Original Filed Oct. 4, 1943 FIGZ.

NIH

\IL I 39 'July 16, 1946. L. c. ROTTER ET AL 2,404,315

REOIPROGATING ENGINE OriginalFiled Oct. 4, 1945 s Sheets-Sheet s V Patented July 16, 1946 RECIPROCATING ENGINE Lutwin C. Rotter, Maplewood, and Victor G.

Klein, St. Louis, Mo., assignors to Lincoln Engineering Company, St. Louis, Mo., a corporation of Missouri Original application October 4, 1943, Serial No.

504,852. Divided and this application December 11, 1944, Serial No. 567,590

This invention relates to engines, and with v regard to certain more specific features to reciprocating air engines for driving lubricant pumps and the like.

This invention is a division of the invention specified in our United States patentapplication Serial No. 504,852, filed October 4, 1943, for Beciprocating engine.

Among the several objects of the invention may be noted the provision of a compactly formed lost-motion coupling between the main reciproeating parts of an engine and its valve gear whereby with a fewer number of parts the valve gear may be located so as to effect better distribution of air to the engine cylinder; the provision of an apparatus of the class described which allows of a better distribution of wear between the engine piston and its cylinder; and the provision of a simplifiedlonger wearing engine valve gear. Other objects will be in part obvious and in part pointed out hereinafter. I f

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of various possible embodiments of the invention, Fig. l is a side elevation of an engine embodying the invention;

Fig. 2 is a cross section taken on line 2--2 of Fig. 1, parts being shown in elevation;

Fig. 3 is a section taken on line 3--3 of Fig. 2 Fig. 4 is an enlarged-vertical section taken on line 44 of Fig, 2 showing certain parts overcentered upward; and, v

Fig. 5 is an enlarged horizontal section taken on line 5-5 of Fig. 4 but showing parts in dead center position.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

In United States Patents 2,215,852 and 2,269,-

1942, respectively, are shown valve mechanisms and the air engines which they serve, upon which the present invention is an improvement; The present invention is an improvement of that type I 423, dated September 24, 1940, and January 13,

of valve gear and upon the location of it on the air engine cylinder. Instead of being at the end as in said patents, the valve gear is on the side of the cylinder. The valv gear itself is improved by providing a better straight-line trip-shoe ac- 5 Claims. (Cl. 74-100) motion mechanisms, a laterally located lost-mo-.

Referring now more particularly to the drawings, numeral indicates thecylinder of the engine,'numeral 3 is the piston on the piston rod 5, the latter passing through a packing gland I. A cylindric frame 9 connects the cylinder I with the pumpv i. The rod 5 is directly connected to th'e rod l2 of the pump II for direct-connected reciprocating driving purposes. The cylindric frame 9 is cut away as shown at l0 for access to parts to bedescribed. Other parts are extended as shown at 23 to form a box-like enclosure for a linkage to be described,

One side of the cylinder is provided, aS indicated at numerals I3 and I5, with inlet and exhaust ports with which a D-valv l1 cooperates. In cover I9 is the valve gear per se. The operating stem of the valve is shown at 2|. This stem 2| passes through a reciprocatin gland 5| and is located at its opposite end in a bearing 53. In the bearing 53thestem carries a sleeve 55attached to it by means of a pin 51. This forms a shoulder 53 for purposes which will appear.

Sliding on a reduced section 59 of stem 2| is a trip shoe 5|, By reason of the upper shoulder 53 formed by a sleeve 55, and a lower shoulder 65,

the stem 2| has lost-motion engagement with respect to the trip shoe 3| whether the shoe be up or down. The trip shoe has end shoulders 61 and 59 which provide lost-motion engagement between the shoe and the D-valve l1.

Extending from the trip shoe BI is a pin 1| which reaches through a fork or clevis 13 of a rocker 15. Within theclevis the pin 1| carries a roller 11. The roller 11 rolls on a vertical guide surface 18 which forms part of a U-shaped mem- ,ber 19 bolted to the cover l9 as indicated at 8|. Guides are formed by the edges 83 of the member 19 and bya shoulder 850i the cover l9. These guides are for a sliding yoke 81 which is pivoted at, to an air-tight plunger 9|. The plunger operates in a stufiing box 93 and carries an exteriorly extending tell-tale 95.

The rocker 15 is supported by (and slides in) out the plunger vthelD-valve- [.1'. t leftward bias of the yoke 8''! (from plunger 9!) urges. the rocker 'further-counterclockwise. At

a fork 91 which has a pivot 99 in a bearing lill of the case l9. Beyond the fork 91 the rocker 15 is made as a fork or clevis I03 for receiving a second roller I535. The clevis has extended ends I 81 movably engaging opposite faces of. the adjacent portionof the yoke 81. This guidesv the rocker co-planar with the yoke.

The roller I05 contacts a driven face I 69 of the yoke 81 which although movable is at all times parallel with face 18. Face 18 is turned into the plane of the yoke (Figs. 4 and 5") Thus if the rocker is moved counterclockwise: tFig. 4 the roller 11 will traverse face 18: and roller I325. will traverse face I29, thus driving the yoke 81 to the right. This pulls in the plunger Hit.- The plunger is biased outward by air pressure carried within the cover [9. This pressure is supplied the air admitted from inlet opening Ill and which passes to the port l3 via the -D-valve [1 which effects its proper distribution. Thus it will be seen that'the yoke 81 is normally biased to the left (Fig. 4.) by the air pressure tending to push When the rocker 15 rotates counterclockwise, the yoke is pushed to the right. The yoke'reaches its maximum position toward the right. when the rocker 15 is about horizontal (seeFig. 5'). This is the dead-center position. Thereafter further movement of the rocker will cause the yoke to. urge it further in a counterclockwise direction. .Down to the dead-center position, the descending rod 2| is responsible'for drawing down the pin, through cooperation between the shoulders63" and 69.

Movementtoj dead-center position about takes up the lost-motion between the trip shoe 6! and Then upon over-centering, the

this time the distance between shoulders 61 and 65 istraversed. Downward motion of pin TI' being atthis time unimpeded. This drives down the pin"1l,. trip shoe 6|. and D-valve [1. Thus the lost "motion between shoulders 61 and 55 is taken up after overcenteri-ng. The. air pressure in the cover is tending ;toforce the plunger 9l' out of gland-93 causes the bias. Hence the D'-valve .IT is reset to introduce air above the piston 3 when the piston has about reached its dotted line 4 better bearing surfaces for the parts connected with the pin 1| and a longer life. The device is simpler and easier to manufacture than that shown in said Patent 2,215,852.

The stem 2| reaches into the enclosure 23, and underneath a removable cover l4: through an opening I6. In the enclosure is a pivot 25 for a rocker 21. Pivot 25 is held in bearings 26. At the left (Fig. 2) the rocker 21 is pivoted at a clevis 28 with a connecting link 29 (see pivot 3|). The connecting link 29 is pivoted at 32 ina clevis 35 attached to the rod. 2! by threading and a cotter key On th-e right hand side, the rocker 21 is forked as indicated at 31' providing spaced fingers 39.

.Pre'sseda into each finger as of the fork 31 is a rounded hardened wear pin ll. Operating between the pins AI is a driving disc 43. Disc 43 is welded to the piston rod 5. The frame 9 and the enclosure 23 are designed to fit. closely around the described linkage, including the disc 43, exceptat opening I'D which is to permit access.

Operation not already described is as follows: Upon reciprocation, the disc Mstrikesi first one 4! (solid lines, Fig. 2.), and then the other (dotted lines), with lost motions therebetween. The lost motion is of a degree adapted to'produce valve. over-centering snap action only whenever the piston 3 is near. the end of its stroke (see dotted lines in Fig. 2), thus making the engine! of the so-called' full-stroke type.

That is. there is no cut-off expansive event in the. work cycle of the engine cylinder.

Another advantage of the invention is that the connection between the. rocker 21 and the disc 43 is. such that the disc may rotate freely along with the piston 3 which is in the cylinder f, and also the piston rod 5 in the packing 1, as well asthe plunger, of the. pump II in its cylinder. fThus scoring and localized wear is reduced in theseparts. In other words, the reciprocating parts may rotate indifferently in- V stead ofbeing confined topure axial movement.

In addition, the valve gear is placed closer to the point of air delivery in the cylinder I, and there- V fore. the passages l3 and i5 become much shortpos'itio'n shown in Fig.2. This reverses the piston 'fi movement, and through the valve driving mecha hisrn (to be described) ultimately reverses the.

movement-of the stem 2[ whereupon the above" described. action between stem 2| and shoe 5! is repeated'in reverse. 'The only difierence is that this time the lost-motion between the trip shoe .6 i the D-valve [1 is below the valve, and the lostmotion between the trip shoe and thestem 6| exists above between shoulders 69 and 63. In.

this case initial movement of the rocker 15 to dead center position is clockwise. This again forces the yoke 8Tto the right until dead-center Y is reached, whereupon" biasfof" the yoke forces the .rocker further clockwise so that snap-action occurs back to the position shown in Fig. 4, thus the other hand, the latter being necessary for the subsequent downward operation.

This valve gear has the substantial advantage overthose shown in said Patent 2,269,423 in that there is no lateral rocking movement required of the pin H which in the present case simply trans lates in a straight line. This allows for arranging er. Consequently less friction restricts flow of airand capacity is increased. At the same time the operating parts are compactly arranged in a space which is closely surrounded by guarding frame portions which form the connection needed between the engine and pump parts.

It will be noted that the connecting. parts 9 between the engine and. pump forms a cylinder closely surrounding the'cylindric figure swept out in space by the reciprocating disc 43. f

In view of the above, it will be seen that the several objects of the invention are achieved and v other advantageous results attained.

As manychanges could be made. in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a. limiting sense.

We claim:

I 1. Over-centering, Valve mechanism comprising a fixedf'guide, a movable guide moving lat-- ciprocating trip shoe pivotally attached near one end of said rocker and movable along a line between the fixed guide and said pivoting means.

2. Over-centering valve mechanism comprising a straight fixed guide, a straight movable guide parallel thereto, means for biasing the movable guide at right angles toward the fixed guide, a rocker carrying near one end means engaging and movable along the fixed guide and at the other end means engageable and movable with the movable guide, pivoting means supporting said rocker for rotary and relative sliding movement, and a reciprocating trip shoe pivotally attached near one end of said rocker and movable along a straight line parallel to the fixed guide and between it and said pivoting means.

3. Over-centering valve mechanism comprising a straight fixed guide, a straight movable guide parallel thereto, means for biasing the movable guide at right angles toward the fixed guide, a rocker carrying near one end means engaging and movable along the fixed guide and at the other end means engageable and movable with the movable guide, pivoting means supporting said rocker for rotary and relative sliding movement, and a reciprocating trip shoe pivotally attached near one end of said rocker and movable along a straight line parallel to the fixed guide and between it and said pivoting means, said rocker and the engagement regions on the guides being in the same plane.

4. Snap-acting valve mechanism comprising a yoke, a yoke guide carrying said yoke for reciprocating movement, a fixed guide located inside of the yoke and in its plane of movement,

said second guide being at an angle to the firstmentioned guide, a rocker forked at both ends and located within said yoke in the plane of said fixed guide, a roller and a trip shoe pivoted int the fork of the rocker adjacent to said fixed guide and movable in a direction to cause said roller to traverse said fixed guide, a roller in the-fork at the other end of the rocker, a pivoting support for the rocker restraining it to rotate with the pivoted means and to slide with respect to the same during rotation, said yoke having a driven surface engaged by said second-mentioned roller in the plane of the first-mentioned roller and the said fixed guide.

5. Snap-acting valve mechanism comprising a yoke, a guide carrying said yoke for reciprocating movement, a second guide located inside of the yoke and in its plane of movement, said second guide being at an angle to the first-mentioned guide, a rocker forked at both ends and located within said yoke, a roller and a trip shoe pivoted in the fork of the rocker adjacent to said second guide and movable in a direction to cause said roller to traverse said second guide, a roller in the clevis at the other end of the rocker, a pivoting support means for the rocker restraining it to rotate with the pivoting means and to traverse the same during rotation, said yoke having a driven surface engaged by said secondmentioned roller in the plane of the first-mentioned roller, and means biasing the yoke in a direction tending to force the rocker through the pivot means and toward said second-mentioned guide, said last-named means comprising an air operated plunger attached to the yoke.

LUTWIN C. ROTTER. VICTOR G. KLEIN.

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