US2437895A - Connecting rod assemblage - Google Patents

Description

March 16, 1948. ROSE- CONNECTING ROD ASSEMBLAGE Filed June 2, 1944 3mm 3 Zaurence R056 Patented Mar. 16, 1948 UNITED STATES PATENT OFFICE CONNECTING ROD ASSEIVIBLAGE Laurence Rose, Washington, D. 0.

Application June 2, 1944, Serial No. 538,463

Claims. 1

This invention relates to improvements in connecting rod assemblages, and more particularly to the formation of the assembly at the crank-shaft end of the rod.

Connecting rods are generally employed for converting reciprocating motion into rotary motion, or vice versa, one end of the rod being connected to a piston and the other end to a crank of a crank-shaft; if the power is applied to the piston the conversion is to the rotating motionif the power is applied to the crank-shaft, the conversion is to the reciprocating motion. In either case, the crank-shaft end of the rod travels in a circular path the diameter of which is represented by twice the distance between the crankshaft axis and the axis of the crank.

The most .common illustration of the service is the connecting rod installations used in internal combustion motors, the motors generally operating under Otto cycle principles, in which the cycle includes two revolutions of the crankshaft and four strokes of the piston, each piston stroke presenting one-half revolution of the crank-shaft; one of the piston strokes is the power stroke (produced by the firing of the charge), thus setting up the power drive as from the piston to the crank-shaft; the succeeding three strokes of the piston (scavenging, intake, and compression) are provided by the rotation of the crank-shaft, the latter becoming the drive for the connecting rod; due to this condition, motors of this type generally have at least four cylinders with their individual pistons and connecting rods, the crank-shaft having a corresponding number of cranks, the arrangement thus providing for at least one power impulse to the crank shaft during each half revolution of the latter, the ofisetting of the cranks being arranged-in connection with the timing mechanism-to provide for the proper timing.

These well-known conditions are being referred to to explain causes for certain conditions that are present in connection with the operation of each of the connecting rods, and especially of the crank-shaft end of such rods. Since these are spaced apart on the crank-shaft, each will traverse its individual circular path, with the paths having a common axis. And since the paths are circular, each presents certain conditions which are also present (with a different timing) with each of the connecting rods; hence, a disclosure as to one rod will suffice for all. These conditions will be understood from the following:

Assume the motor to have its cylinders above the crank-shaft, thus having the pistons reciprocating vertically with the power stroke of a piston moving downwards; in practice, the timing is such that the charge is fired at such time that the combustion of the charge begins just after the piston has passed its upper dead center, with the axis of the crank-shaft end of the connecting rod approximating a similar position in the circular path. As the piston moves downward, its pressure is applied on the crank of the crank-shaft through the connecting rod, and since the crank-shaft rotates bodily in its axis, the crank will have the travel of the crank pin axis conforming to the circular path, this crank pin axis representing the axis of the bearing insert in the crank-shaft end of the connecting rod.

This travel of this end of the connecting rod and its bearing insert, in traversing the circular path produces a number of characteristic conditions which tend to set up stress conditions of considerable magnitude-the stress magnitude value will depend upon the rotational speed of the motor. For instance, while the travel of the crank-shaft end of the connecting rod will be downwnard and laterally outward at the beginning of the power stroke, this condition ends when the axis of such ends reaches the angular position-the horizontal diameter of the path; the axis continues downwardly after passing this point, but the direction of the lateral component is changed from the previous outward direction to an inward direction, thus providing a reversal of this component; the axis continues its advance under the latter conditions, until the position of the vertical diameter is reached at which time the previous downward component changes to an upward direction while the inward lateral component continues in the same direction to become a laterally outward component with respect to the vertical diameter; this change remains active during the succeeding 90 travel (to the 270 angular position) whereupon the lateral component is reversed to the inward direction with the upward component continuing as before; this relation of the components continues to the point which completes traversal of the path and provides a single revolution of the crankshaft. While this detail analysis presents changes, it can be understood that in effect, the components continue in one direction when traveling through the path on one side of a diameter (vertical or horizontal) and in the reverse direction on the other side of such diameter, With this condition of reversal alternating as 3 between the diameters at midway points of the 180 angular travel.

These four points of reversal in direction during a revolution of the crank-shaft present potential sources of stress development, due to the fact they present points where the normal tendency of the end zone of the connecting rod to continue its direction of travel under kinetic conditions reaches anv endand begins travel-in. a different direction relative to the axis of the crank pin; the effort of the rod end zone to continue in the same direction tends to draw the bearing insert into closer relation to. the crank pin on the opposite side of the latter at the instant of reversal. speed of the motor is increased, since the kinetic value also is increased; with a motor speed 'of 2000 R. P. M. 8000 of such reversals per minutewould be present.

The condition is amplifiedas the weight of such end zone of the connecting rod isincreased, due to the fact thatthe weight factor increase tends.

to increase the momentum effectpresent in the inertia of motion that is. present, thus increas ing the value of the resistance tochange irrdirecr. tionunder the inertia action. Obviously, therefore, the-less the weight of such end. zone of the connecting rod, the less becomes the value of the. stresses which may be set up. It may be noted. that alleviation in the value of the stresses isdependent upon the possibility of varying the weight factor, since the factor previously discussed. is inherently present at. all times of operation of the motor.

However, the-conditions are-accentuated. by thefact that the end zone of the connecting rodmust be secured upon the crank pin of the cranlearm of the' crank-shaft, with both ends of thepin.

closed against endwise positioning of the rod. end-zone, a condition. which necessitatestheuse or a divided rod end zone in order to, permit positioning of the'rod on the pin. In practice. the division line is madeona line. normal to the length of'the connecting rod, this being preferred-,due to. the fact that during the traversal of the circular path this line would extend, angular to-the.hori-. zontal diameter of. the path dueto theinclination of the connecting rod to'the vertical. dameter at the 90 and 270 angular positions on. the. path. thus assuring that the breakin unitary continuity of the end-zone willbe somewhat remote from the positions of reversal at these points-the re.- versals at the other points are remote from the break points to a maximum extent since the connecting rod is in correspondence with: the. vertical diameter at such times.

Under modern practice, the actual bearingsurface of the rod end zone on the crank pin is provided by a thin shell of special alloy metal. ofv circular contour and provided with side flanges. which overlie the opposite faces of the. rod end. zone, thus permitting renewal by simple substitution of one shell for another--the,. shells. are. known'as bearing inserts. Since such bearing iii-- sert encircles the crank pin it is necessary toiorinit sectional similar to the end zone, the -two,sec.-- time being accurately dimensioned to. fit the pin when in position thereon; since the insert is not united to the connecting rod, bodily creeping of theinsert is possible,v so that the lineof meeting. of the insert sections-which correspondsqto a diameter of the insert-may vary its position relative to the line of meeting of the rod end-zone sections; but this does not renderv the insert more vulnerable to the actions produced by the re- This effect increases: as"the;-:

versals above referred to, since, if the two meeting lines are in alined position, the insert meeting line will be remote from the points of reversal similar to the line of the rod end zone-when out of alinernent, the insert will be protected by unitary portions of the rod end-zone.

This arrangement of the insert permits the rod to be made lighter in weight through selection of rod material, but; the reduction in ossible weight is limited by the fact that the sections of the rod end zone must be secured together and with a strength suflicient to prevent separation; for instance, during the third stroke of the cycle--the intake stroke--the power is provided by the crank-shaft; thus placing the power application upon the removable section of the connecting rod endzone, thus requiring a connecting means of sufficient: strength to not only ensure the proper maintenance of the bearing insert in proper operation, but alsohto resist separation during this stroke.

In modern practice, such connection is provided by increasing the thickness of the rod within the end zone of the rod and forming a bored housing thereon on, each side, the housing and its bore crossing thejunction line of the end zone-thus dividing. the housing. toplace the two sections of the housing asv respectively unitary with the sectionsof the end, zones being connected; each section of the housing. is of considerable length axially of the bore. with the. two portions generally of similar length; the bore is designed to receive a bolt the head. of which is above the upper section (and preferably arranged to prevent bolt rotation), the opposite end of the bolt being exposed below the lower section to. receive the nut, suitable means (such as radial keris on the under face of the nut, and a cotter pin mounted in a selected kerf and extending through a diametrical opening in the bolt) being provided to retain the bolt in its-secured position, this structure beingsimil-ar onopposite sides of the end zone, Intermediate the bottoms ofthe housings, the bottom of the end zone is formed with a rib. to give strength to the lower section ofthe end zone of the; rod.

This: structure provides sufiicient strength to maintain theintegrity of the end zone against separation, whilepermitting ready assembly of the rod endzone and bearing insert on the crank pin, thus making it possible to substitute bearing insertswithout requiring expert assistance. However, it is a structure that adds materially to the weight of this zoneof the connecting rod, as can be understood from the fact that the housing must include a straight bore with the latter extending in a line that is practically tangent to a circle; since the housing at. the division line must have a dimension sufficient to house the bolt outside of the bearing openingwith this dimension as the smallest projected portion of the housing and since all portions of the housing must be in secured relation to. the assembled circular. portion. of the end zone, the structure sets up-a weight factor of considerable amount, especially since smooth running requires that the weight distribution should approach symmetrical conditions as closely as possible.

The. present invention has for its principal object a reduction in this Weight factor Without affecting the strength or operating efiiciency of the connecting rod and also to permit ready substitution of bearing inserts. The reduction is provided bychanging the manner of connecting the sections of the end zone of the rod. With the exception of the housings and bolts, the connecting rod remains generally as before, the present invention substituting a difierent form of fastening means and a change in the form of the required body to receive the means, the change materially reducing the weight of this zone of the rod. Since, at high speeds, such reduction reduces the service eiiects set up by the conditions described above in detail, the invention will tend to reduce wear development to provide longer life to the bearing inserts, and provide for smoother operation of the assembly.

This latter can be understood somewhat by considering the general characteristics of kinetic energy. The general condition is indicated by consideration of the fact that the value of kinetic energy increases with the mass and with the square of the velocity mv (1mhence, any decrease in the weight of the crankshaft end of the connecting rod (mass) reduces the value of the kinetic energy in accordance with the above formula, in which 12 represents the velocity. Obviously, any material reduction in weight, even if small, provides a considerable reduction in the angular momentum values which are present at the instants of reversal in direction referred to above, especially under high speed operation, thus reducing the stress values at such time.

To these and other ends, therefore, the nature of which will be better understood as the invention is hereinafter disclosed, said invention consists in the improved construction and combination of parts as described hereinafter, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference characters indicate similar parts in each of the views Figure 1 is a view in face elevation of the crank-shaft end zone of a connecting rod showing the invention applied thereto.

Figure 2 is a sectional View taken on line 2-2 of Figure 1.

Figure 3 is a sectional View taken on line 3-3 of Figure 1.

Figure 4 is a perspective view of one form of key employed in the invention.

Figure 5 is a view in side elevation of another form of key which may be employed.

The connecting rod, designated as i9, has the general characteristics of the general form of rods in practically universal use, no change being made in theform of the piston end of the rodthe reason for omitting this portion in Figure lthe change being in the end-zone which cooperates with the crank-shaft; likewise, the body portion ii intermediate the end-zones re mains unchanged. Similarly, the crank-shaft end-zone, indicated at I2, is enlarged diametrically to provide the opening !3 for the crank pin (not shown). the thickness dimensions being sinol"? to those in general use; and the end-zone has the usual dividing line extending on a diameter of the end-zone and the opening, with the diameter extending normal to the length axis of ti: rod, to therefore provide the lower end i2a as a removable section to thereby permit the rod to be secured on the crank pin, the complemental portion of the body portion of the zoneindicated at I la, being formed unitary with the body H. In addition, opening [3 contains the usual divided bearing insert l4.

One of the changes made from the usual form is that of extending the external rib throughout the periphery of the zone with the exception of that portion included in the body portion of the rod within the zone, the rib, indicated at I5, being carried by both portions Ila and We and therefore divided on the diameter heretofore referred to.

Another change is in connection with the faces of the end-zone, Under the usual practice, this face, in the assembly, is not only completely annular, but completely circular externally, the housing heretofore referred to being depressed with respect to the plane of the face. In the present embodiment this is preferably changed to provide an enlargement l6 at opposite sides, with each enlargement symmetrically disposed relative to the division line referred to, so that each enlargement is divided by such division line, the preferred form placing the face of the enlargement as in the plane of the usual face and extending to and formed integral with rib I5; however, it will be understood that the face of the enlargement may be varied as to dimensions, if

desired, such change being deemed within the spirit and scope of the invention.

The peripheral contour of the enlargement may be of desired form, but is preferably curved and preferably extends outward to the outer dimension of the rib. This is preferred since it tends to provide a streamline eifect to the zone while traversing the circular path traveled by the crank pinthe rod becomes angular to the vertical when the pin reaches the horizontal diameter of the circle and reaches the vertical when the pin is on the vertical diameter of the circle-conditions which provide a swing of the enlargement about the axis of the pin first in one direction from the horizontal diameter position, and return, and. then in the opposite direction and return, the horizontal diameter position being present when the rod is on the vertical diameter; under high speed operation, the curvature of the enlargement offers the least resistance and thus provides for less turbulent air conditions in the path of travel of such end-zone.

The chordal thickness of the enlargement at its base is sufiicient to assure ample support for the securing means, presently described, to assure non-separation of the lower end of the connecting rod from the body by the stresses produced by the assembly in operation; since the enlargement is preferably arranged symmetrical to the horizontal diameter the latter bisects the chordal thickness. In practice, the line of the chordal thickness will, however, preferably have a length less than the inner diameter of the bearing insert, so that the volume of metal within the enlargement is considerably less than that found in the housing of the prior art form discussed above; while the rib structure reduces the amount of difference, this change in form provides a very material reduction in the weight of this end zone of the connecting rod, a reduction value which is enhanced by the change in the securing means which, in the present invention, is in the form of a key the weight of which is-considerably less than the weight of the bolt and nut structure for which it is being substituted.

The securing means is in the form of a complemental key and slot positioned in each of the two enlargements, and of a somewhat particular configuration. These configurations may be anemone varied- -two forms of keys. are disclosed to illus trate possibilities, and it isto be understood that the forms shown are representative and may be still further varied to meet individual conditions and the preferences of the user, such changes being: considered within the present invention.

The key configuration of both of the forms shown presents, in vertical cross-section, a verti-cal web portion Ila (and Ila) and a pair of horizontally extending heads Nb (and Nb) at the top and bottom; of the web, thus presenting somewhat the apperance of the letter H; the vertical height of the web is such as to provide I a distance factor suchthat when the web is mounted symmetrical to. the horizontal diameter of the end zone, a material amount of metal of the enlargement of both portions of the end zone will be located between'the heads Ill) and lib). The key I! shown in Figure 4, has the length of the web- Ha as approximating the axial length of the end zone, as represented by the length of the enlargement in the same direction; in this form it is preferred that the length does not ex ceed this distance, and may be less than such distance, but must be suflicient to provide the strength needed to resist separation of the parts of the end zone. In this form, the length of the heads l'lb is such as to extend beyond the ends of the web, as shown. In addition, the web, in side elevation presents the vertical distance between the heads as progressively increasing from one end to the other of the web; the variations arepreferably equal with respect to the two heads, the web thus presenting the appearance of a face diverging from one end to the other, the inner faces of the heads thus presenting characteristics of wallsof a slight tapered formation.

The. key shown in Figure has its vertical cross-section similar to that shown in Figure 4, but therelative length dimensions are reversed as compared with Figure 4the heads I'll) have the length of the webin Figure 4, while they web He has the length of the heads ill) in Figure 4; in addition, the extensions of the web are each preferablyrovided with slots l'l'c extending inwardly from the free ends, thus, in effect, dividing the extensions into a pairof tongues l'id for a purpose presently referred to-the extensions of the heads in Figure 4 are designed to serve as tongues for a similar purpose. As in Figure 4, the web has the-progressively increasing width toward one end, thus producing the slight tapered formation of the key formation as in Figure l.

The cross-section of the slot formation of an enlargement is complemental to the cross-section of the key, with the web zone extending across the horizontal diameter which provides the division line of the end zone of the rod, while the head portions of the slot extend in the slightly angular directions presented by the heads of the key formation, so that the slot formation will present a substantial replica of the various crosssections of the key formation when the body portion H and the crankeshaftend zone l2 are in their working positions of complete contact. In other words, the top and bottom faces of the head portion of the slot are parallel, but the faces extend in a direction that is inclined away from and toward the division line of the end zone, with the inclination extending from one face to the other of the rod end-zone, while the side faces of the head slots are parallel and spaced to provide a working fit for the corresponding faces of the heads of the key.

Inpractice, the dimensions of the slots of the end zone configuratlonswithin each of the enlargement portions ofthe crank-shaft end zone of the. connecting rod. correspond generally with those of the body of the. key when the two parts of the end zone are drawn together on the line of division of such parts; the slots are arranged symmetrical relative. to such division line, so that the widths of the web. portion of the key will be found symmetrically positioned within the slots with the web extending across such division line. In other words, with the keys properly positioned, the end zone assembly becomes the equivalent of a unitary structure so far as operative effect is concerned.

Since,:to produce this efiect, the slots must conform to the slighttapered width configuration of the key, it is apparent that in assembling the connecting rod and crank pin, the key must be inserted in its slot by movement in an endwise direction of the key, with the larger web end introduced into the slot end which receives the smaller width of web. To permit key introduction, therefore, the two parts of the rod end zone-after the bearing insert: has been positioned on the crank pinare retained separated a distance suiiicient to place the head portions of the slot at the key entrance end in alinement with the head portions of the larger end of the key, whereupon the key is introduced and shifted along the slot. And since the key remains unchanged in dimensions, and the head portions of the slot also remain unchanged in dimensions, the change in dimensions due to key movement is temporarily provided by the spacing of the end zone parts on the line of division of the parts-the inner faces of the key heads, during the shiftin action, will contact the complemental faces of the slots with the effect of drawing the two parts of the rod end zone closer together, this continuing until the two parts of the end zone are drawn tightly together, due to the effect of the tapered form of the web.

The wedge-like values are comparatively small (possibly .001 to .002 inch for each head) so that the spacing of the end-zone members for the purpose of the key may amount to .002 to .004 of an inchit being obvious that both keys will be inserted into the entrance to the slots before beginning advance of the keys in the slots. To decrease this initial spacing, the outer faces of the key heads may be slightly chamfered at the end which is to be introduced-as at lle'thus decreasing the thickness of the entrance end face of the key heads-after entering, the spacing of the rod end zone parts will be controlled by the key; in the Figure 4 form the chamfering will provide little effect in the appearance of the completed assembly, while in the Figure 5 form the small chamfering values-have no material efiect on the strength of the joint, and the small opening provided by the chamfer will have little effect in the appearance and then only on one of the opposite faces of theend zone occupied by a key. Obviously, the taper formations of the slots may be arranged to expand from the same face of the rod end-zone, or may extend from opposite faces of such zone; the former is preferred since both keys are then inserted on the same face of the end zone.

After the keys have been advanced to the desired position, at which time the extensions (the ends of the heads in the Figure 4 form, and the extensions lid in the Figure 5 form) project beyond the faces of the assembled rod end-zone, these extensions are then bent over into contact with end-zone faces, as indicated in Figure 3, for instance. This locks the key in position; this may be done only at one end of the key-the Wider end-but it is preferred to do this at both ends to prevent movement of the key due to the inherent vibratory effects produced by the travel of the end zone assembly in the circular path. The Figure 3 presentation is that of the Figure 4 form of key, in which case the extensions become located outwardly beyond the slot top and bottom contours; in the Figure 5 form, in which the extensions are carried by the web, the extensions are moved outwardly in the lateral direction-while a single extension might be utilized (and is contemplated within the invention), the dual form shown is preferred, this permitting the two extension portions to be shifted in opposite directions, thus tending to maintain the key against any possibility of rocking, being similar in this respect to the bending of both heads in the Figure 4 form.

The description above as to drawing the two parts of the rod end-zone tightly together, presents the preferred method of utilizing the invention. While this would seemingly limit the amount of wear possible on the bearing insert,

the fact that the insert is of a special alloy designed to withstand rapid wear, together with the fact that adequate lubrication is always present, tends to produce comparatively long life to the insert; this is especially true because of the fact that with such arrangement the bearing insert can provide its internal opening as of truly cylindrical type at the time of forming the insert, and thus provide a perfect complemental relation with the crank pin when the connecting rod is installed-the lateral flanges .at the sides of the inert will normally maintain this relationship; the same conditions would be present where the two halves of the insert are slightly less than 180 of angular length, thus leaving these halves slightly spaced apart.

However, it is apparent that if it is desired to utilize self-conforming inserts-inserts which can slightly change their form through resiliency and without producing material change in wear conditions, the two parts of the rod end-zone may be retained slightly spaced apart initially, making possible the taking up of wear by later driving the keys inwardly a greater distance and thereby draw the parts into closer relationship. Where this method is employed, the taper values could be slightly increased so that the drawing action could be provided with a comparatively short range of key-driving action. While this method may be employed-and is considered within the inventionits use is less preferred, due to the need for the resilient insert characteristic and the possibility of unequal wear conditions being set up.

When substitution of a bearing insert is necessary, the extensions at the larger ends of the keys may be brought back to their initial positions by the use of a suitable tool, after which the key is driven out in a reverse direction from which it was introduced, thus tending to separate the rod-end zone parts through the taper action thus facilitating the separation of the parts; in such case careful manipulation of the extensions will permit re-use of the key; or the extensions may be cut off, leaving the key free to be driven out and thus limit the life of the key to the single use.

As will be understood, the change in construction provided by the present invention, as compared with the present commercial practice above described, presents a very material advantage in favor of the present invention, due to the very material decrease in the weight of the rod endzone assembly. While the usual rib zone is extended in the present invention, the enlargement area is small as compared with the housing of the commercial form. In addition, the weight of the key is greatly reduced as compared with the weight of the bolt, nut and cotter pin utilized in the commercial form. Since this weight reduction is present on opposite edges of the endzone assembly, the totality of reduction assumes considerable value, a condition which is of positive advantage when the rod'is in service with the end-zone traversing the cylindrical path. The weight reduction reduces the kinetic energy values which must be overcome at the instants of reversal of direction explained above, thus tending to reduce the stresses inherently present as well as vibratory effects; obviously, wear tendencies will tend to be reduced because of these conditions.

While I have herein shown and described several Ways for carrying the invention into effect, it is apparent that changes or modifications therein may be found desirable or essential in meeting the exigencies of use and the individual desires of the user; I therefore reserve the right to mak any and all such changes or modifications as may be found desirable or essential, insofar as the same may fall Within the spirit and scope of the invention as expressed in the accompanying claims, when broadly construed.

What is claimed is:

1. In connecting rod assemblies, wherein one end zone of the rod is formed with a bearing opening and is operatively mounted on a crank pin or analogous structure extending within such opening and operative to travel with the pin in a circular path, wherein the assemblage includes an insertable bearing insert mounted on the pin within the bearing opening, and wherein such rod end zone and the bearing insert are each of sectional formation to permit mounting of the assemblage on the pin and the insertion and removal of the bearing insert Within the assemblage at will, the combination with such assemblage, of means for operatively securing the end zone sections together about the pin and'the interposed bearing insert, said means including an insertable key formation having its lengthwise direction extending in general parallelism with the axis of the bearing insert, and a complemental slot formation in such end zone, said key and slot formations being symmetrically disposed relative to the opposing faces of adjacent sections of the end zone to operatively connect such sections and prevent separation thereof during service, a cross-section of said key forma tion including a web portion with a pair of spaced head portions integrally united thereto at opposite edges of the web portion and with the head portions projecting laterally beyond a side face of the web portion, the slot formation presenting the web-receiving portion of the slot as crossing the division line between the rod endzone sections at an angle to such line, said Web portion of the key having the depth of its face of gradually-increasing dimension from end to end of its active section-holding length to thereby provide a dimension of tapering characteristic between the opposing inner faces of the laterallyprojecting zones of the head portions, whereby key advance after key insertion in the slot form'ation will cause the adjacent sections to be drawntoward each otheig at least one of said key portions having an extension projecting at the advance en'd of the key and adapted to be bent up'onan adjacent exposed face of the end zone to thereby anchor the inserted key against undesired releasing movement of the key due to vibratory effects,

2. An asse'mblage as in claim 1 characterized in that the rod 'end zone is divided on a diameter of the bearingopening extending normal to thedirection of length ofthe connecting rod to thereby provide a two-section rod end zone, a second key formationand slot formation being 'providedatthe diametrically opposite side of the rod end zone. 7 7

3. An fassemblage 'as in claim 1 characterized in that the rod endjzone is divided on a diameter of the bearing opening extending normal to the direction 'Qf fIBII gth of the connecting rod to thereby provide a two section rod end zone, a second ke'yform'ation'and slot formation being providedat the diametrically opposite side of the rod end zone, thekey and slot formations at both poiptsnbeing substantial duplicates,

4 Anassgmblage as, in claim 1 characterized in that the end zon'e'of the rod presents the usual reinforcing rib characteristic in extended form with the adjacent section's combinedly providing additional enlarged face reinforcements integral with the rib"formation and dimensioned to include theislot'forma'tionwith the heads of the slotvspaced from the peripheral contour of the reinforcements'and from the division line between the sections. I

5. An assemblage as in claim 1 characterized in that the end zone of the rod presents the usual reinforcing. rib characteristic in extended form with the adjacent sections combinedly providing additional enlarged face reinforcements integralwith the rib formation and dimensioned to include the. slot formation with the heads of the slot space d,,from the peripheral contour of the reinforcement and from the division line between the sections, such contour being curved arcuately to presentv a substantial reinforcing formation at, the section securing point of limited weight characteristic with the contour tendingrto provide streamline action to the end zone duringservice. to V V 6. An assemblage 'as in claim 1 characterized in thatth'e key includes an anchoring extension at its r'ear end in addition to the extension at the'advahfce end, to thereby rigidly anchor the key against all vibratory action.

7*. assemblage as in claim 1 characterized in that each head portion of the key carries an anchoring extension. I

8. An assemblage as in claim 1 characterized in that the web portion of the key carries an anchoring extension.

9. An assemblage as in claim 1 characterized in that the web portion of the key carries an anchoring extension with the extension divided to permit bending of one of the divisions in a direction opposite the other division to thereby stabilize the key.

10. An assemblage as in claim 1 characterized in that the outer face of each head of the key has its leading edge 'cham'fered or rounded to thereby permit ready entrance of the key within the slot and aid in controlling the positions of the adjacent rod end sections being connected by the key during key-entering operations.

LAURENCE ROSE.

REFERENCES CITED Thefollowing references are of record in the fileof this patent:

UNITED STATES PATENTS Number 7 Name Date 137,227 M'arJ25, 1873 234,370 f Hdi heS -Q'NOV. 9, 1880 236,099 Huber et a1. -1 Oct. '2, 1883 "401,585 'Pollar'd Apr. 16, 1889 466,622 Oren'stein Ja'n. 5, 1992 714,955 Shartle' De'c."2, 1902 1;00'1,11s Langlands Oct. 31, 1911 1,158,436 Bowen Nov. 2, 1915 1,219,382 Dunlap Mar. 13,1917 1,469,527 Oud'erkirk Oct. 2,1923 1,525,982 Clark et al. 1 Feb. 10, 1925 1,721,561 Jensen Ju1y 23, 1929 1134 10 Wells -Nov. 5, 1929 2,134,765 "Putnam nov. 1,1938 2,146,493 'Wintzer 'Feb. 7, 1939 FOREIGN PATENTS Number Country Date 413,272 'Great Britain- July '9, 1934 615,243 Germany July 1,1935

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