US1530481A - Side frame for trucks - Google Patents

Description

March 24, 1925, 1,530,481

G. s. CHILES SIDE FRAME FOR TRUCKS Filed Nov. '25. 1923 3 Sheets-Sheet 1 mum Q Inc/enter RS8 eazyca 5%, QM

March 24, 1925.

G. S. CHILES SIDE FRAME FOR TRUCKS Filed Nov. '25. 1925 5 Sheets-Sheet 2 March 24, 1925. 1,530,481

G. s. CHILES sxns FRAME FOR TRUCKS Filed Nov. 23 1923 3 Sheets-Sheet 5 I mun Patented Mar. 24, 1925 UNITED} STATES 1,530,481 PATENT OFFICE.

GEORGE s. CHILES, or LIMA, onto, ASSIGNOR 'ro THE OHIO STEEL FOUNDRY cou- PANY, or LIMA, OHIO, A conronarron or OHIO.

smn FRAME non ravens.

Application filed lll'ovember 23, 1923. Serial no. 676,469.

T all whom it may concern:

Be it known that I, GEORGE S. CHILES, a citizen of the United States, and a resident of Lima, county of Allen, and State of Ohi'o, have invented certain new and useful Improvements in Side Frames for Trucks, of

I which the following is a specification.

This invention relates to improvements in east side frames for trucks, and has for its principal object to produce a casting giving the maximum strength with the minimum weight commensurate with facility in manupright columns 12, 12 spaced apart .at the ufacture by ordinary foundry methods.

The invention consists primarily in the provision of a novel distribution of metal particularly in the tension and compression members in which members the principal characteristic is the provision of curved or semi-circular cross-sections as distinguished from the ordinary and well known sections such as T or U shaped sections whereby the structural members presenting my novel section are arranged to cooperate with each other and with other portions of the side frame to the greatest advantage as will hereinafter more fully appear.

The invention may best be understood by reference to the accompanying drawings, in which- Figure 1 is a vie-w in side elevation of a side frame casting constructed in accordance with my invention.

Figure 2 is a top plan view of the casting shown in Figure 1.

Figure 3 is a bottom plan view of the casting shown in Figure 1.

Figure 4 is an enlarged section taken on' line 4-4 of Figure 2;

Figures 5, 6, 7, 8, 9 and 10 are sections taken on lines 5-5, 6-6, 77, 88, 99, and 1010 respectively of Figure 4.

Figures 11, 12 and 13 are'detailed views illustrating comparative differences respectively between typical T, U and my improved oval sections.

Figure 14 is a detailed fragmentary view showing a modified form of casting.

Figure 15 is a face view of the modified form shown in Figure 14.

Referring'to details of the drawings, it will be' seen that the side frame is made 0 an' integral casting 10, including journal boxes 11, 11 at opposite ends, and a pair of central portion of the frame, between which a transverse bolster, spring plank, and springs, (not shown) of the usual well known form, are supported. The main frame carrying members comprise an upper or compression bar 14 and a lower or tension bar 15 both of said bars in effect extendingthe entire length of the frame on opposite sides of the columns and converging toward the ends of the frame.

The upper bar 14 comprises three main portions, namely, a central portion 16 extending between and substantially at right angles to the columns, 12, 1 2, and two end portions 17 17 each inclined downwardly as shown from the central portion 16. Projec tions'or arms 20, 20 and 21, 21 may be cast at the side of the columns-adjacent the upper bar 14 which in the present instance are for the purpose of supporting the brakes which are not shown, as they form no part of the invention. I

The portions 17, 17 are substantially semicircular in cross section being arched or curved inwardly from their central point and open at the bottom as shown in Figure I 5. This feature will be hereinafter referred to in greater detail as it comprises one of the principal features of my invention.

Similarly, the lower bar or tension member 15 comprises a central portion 24 and two end portions 25, 25. The central portion eon'iprises a channel section as shown in Figure 10 having laterally extending flanges 26, 26 to form a platform for the spring plank of the usual construction. The central portion merges into the end portions 25, having a curved or arched cross section similar to the section of the upper end portions 17, 17 but an inverted relation thereto as shown in Figures 6, 7 and 8. The

adjacent end portions 17 and 25 converge.

toward their respective ournal boxes 11,' the respective side flanges joining near the journal boxes to form a flat. web 27 as shown. The upper curved portion of the compression member 14 merges into the top of the journal box as shown in Figure 9, said journal box preferably lying below the junction point of the two bars 14 and 15. The jourf nal boxes 11, 11 may be of any suitable form to house the axle bearings, the latter being omitted as they form no part of the present invention.

As will appear from Figures 2 and 3, the bars 14 and 15 are tapered in width from their respective central portions .16 and 24 toward their ends. This is preferable because the transverse bending moment, due to a side stress or load, is not uniform throughout the length of the frame, but 15 greatest at the columns 12, 12 and decreases substantially uniformly toward the ] ournal boxes 11, 11.

Referring now in greater detail to the oval shape of the cross sections of the portions 17, 17 of the compression member 14, and portions 25, 25 of tension member 15, a few preliminary remarks regarding present practice in design and foundry practice will be helpful.

In practical application to side frame castings it has been demonstrated that the strength requirements at different points of the casting varies widely due to the nature of the opposing forces set up in the truss frame of this class. For the most eflicient design these variations require an increased metal distribution at certain points.

The forms of sections heretofore widely employed in castings of the general class herein contemplated are the T or I sections, (the latter being considered a modification of the former), and the channel or U section. A few L sections have also been used. The channel section is now generally preferred as it gives a greater resistance to transverse and twisting forces. An example of the T section is shown in Figure 11, and an example of a 'U or channel section is shown in Figure 12.

A practical design of channel, T or L section requires a certain end width, depth of side walls,-and metalthickness in order to be readily formed in a relatively large casting, in which the metal will flow evenly and eliminate excessive internal strains when cooled. With such requirements, however, it has been demonstrated that in attempting to increase the strength of such sections of ordinary format certain points as called for by strength requirements, it is quite often necessary to provide a total metal area which is in excess of the actual strength requirements. By way of illustration, it will be seen that in Figure 11 representing a standards/T section, a dotted line 30 is drawn through the center of the top web 31 of the Teand a similar line 32 extending the length of the upright web 33. Similarly in Figure 12, showing a standard U section, a line 34 is drawn through the center of the cross bar 35 and uprights 36, 36. These lines 30, 32, and 34 are what may be termed a metal line of the respective sections, that is to say they are the medium lines up of the several web portions which make up each I section.

One of the characteristics therefore of any given section 1s its total prises the total length of lines 30 and 32 I whereas in the U section, the metal line is the total length of line 34, extended. It will be understood that in castings of the character described the various web portions of each section are preferably of uniform thickness, the thickness in each instance being as far as possible the minimum for given strength requirements commensurate with facility in the casting operation so that the metal will flow readily and the finished castings will have no undue internal strains.

Referring now to my improved form of section, which I have termed for convenience, the oval section, as illustrated in Figure 13, this general form of section is utilized throughout various portions 17, 17 of the compression member 14 and 25, 25, of the tension member 15, as shown in Figures 5, 7 and 8. It will be observed that the oval section has a shorter metal line 50 than the T or U sections of the same width and height. The length of the metal line being less in the oval section, the cross-sectional area is less for the same thickness of the section, since the total areas are in direct proportion to the metal lines. Therefore, the oval section permits a greater latitude in its formation where variations are necessary to meet the strength requirements with a minimum area at all points. For instance in the bar sections 17, 17 and 25, 25 the strength requirements may vary considerably at different points, depending upon the design of the frame. The saving in area due to the shorter metal lines of the oval section may be partly or completely employed to reduce the weight of the castings over a T or U- shaped section having a longer metal line. For example: the saving in area may be used either to thicken the metal wall or to increase the depth in the side walls. Again a new oval section may be designed having both the thickness and depth increased over that of the T or U shaped channel but having an equal area.

A further advantage presented by the oval section is that of the distribution of the cross-section area about what may be called the center of mass of such area. In the T or U sections this center of mass is quite near the transverse 'web or wall thereof in each instance. It has been demonstrated however that a large proportion of the stress on the tension and compression members of a side frame is toward the inner margin of the frame members. In most instances, tests determined by strain gauges show that the stress at certain outer portions of the frame both in the tension and compression members is at a minimum often approaching zero. With channel and I section mem-' bers, therefore, it will be seen that the cen- I line of force to ter of mass is improperly located near the" outer edge of the tension and compression members, where the stress approaches zero. In the improved oval section, however, the center of mass is farther removed from the outer edge of its respective members so that it is in closer proximity to the approximate be transmitted as illustrated in Figure 4, in which the lines 404O and 41-41 are drawn through the centers of mass of adjacent sections respectively of members 17 and 25. The center of mass of the oval section being nearer the mid-position, that is to say, the line drawn throng the mean depth, than it is through the channel or T sections, the oval section presents a more economical distribution of metal for the urpose of withstanding the forces applie thereto.

In addition to a shorter distance from the outer edge in sections of equal depth, the side wall depth may be and usually is increased where necessary by extending the exterior lateral walls inwardly from their outer margins to form strengthening portions '37, 37 'as shown by comparison of Figures 7 and 8. The thick walls may also be increased.

ness of the side and the side surfaces may be extended outwardly to'shoulders 38, 38, thus shifting the center of mass and yet retaining the advantageous features of the oval section heretofore set forth. In the case ofFigure 7 the center of mass is still further move from the outer edge.

It will be seen therefore that the oval section may be used in two ways in bringing the body of the resisting metal in closer coincidence with the lines of force. It has been demonstrated that at certain locations the stress may be much higher whileat a position directly opposite on the same member the stress is correspondingly low. condition may be remedied to a great extent by the shifting of the center of mass lines, and the stress'may further be reduced tially over in the oval section since it lends itself to a greater variation in the thickness of the section area for a given width and height than is the case in channel or T sections.

It will be seen that the center of'mass lines 40-40 and 41-41 of members 17 and 25 re spectively, are arranged to intersect substanthe center line of the journal box ll'thereby producing a It will further be observed that the converging oval sections at the ends of the frame present ineflect a, torsion member on an axis longitudinal of the frame in which 'the outer extremities of the upper and lower members approximate a circular surface. This arrangement affords a uniform resistance to torsion on the longitudinal axis of the frame and. to variations from the northe center of mass being at,

and material which drawn,

This

balancing of forces glIlS. the supporting axle.

mal parallel positions of the axles with respect to each other.

With respect to the portions of the frame between the columns 12, 12, I find that the form of U section is prefer. ble asshown in Figure 10 as here there is usually a definite height limitation. As hereinbefore described, however, these channel sections intermediate the columns merge into the oval section at points above and below said columns as illustrated; .;,for instance by comparison of Figures 6 and 10.

In the modified form illustrated in Figuresh 14 and 15 I have shown an aperture 45 formed the lower wall of member 25 and in approximate alignment with the center of the U section 24 intermediate the columns.

This aperture is provided for supporting the ends of the core forming the interior of the Usection 24 and I find that it maybe formed at this point without appreciably diminishing the strength of the member 25 through which it passes, inasmuch as the stress at this point usually approximates zero. These openings also serve as drain holes, assist in the cleaning out of the sand and core rods incident'to manufacture, and permits of water enters the frame at the open part in service to escape.

A casting constructed in accordance with the above description is particularly adapted for easy handling under ordinary foundry methods. The hollow portion between the d columns and also between the columns and the journal boxes may be readily cored and I the mould being, easily parted espe cially at the oval sections. also lend themselves to the'easy and uniform flow of metal throughout the casting.

I claim as my invention:

1. A side frame consisting of an integral casting including tension and compres- The oval sections sion members and intermediate columns, said tension and compression members beyond said columns consisting of cross sections curving inwardly at substantially all points beyond the'central median lines thereof.

'2. Aside-frame consisting of an integral casting including tension and compression members and intermediate columns, said tension and compression members beyond said columns consisting of cross sections having a substantially" continuous inward curve from their mid point to their inward mar- 3. A side frame consisting of an integral casting including tension and compression members and intermediatev columns, said tension "and compression members between said columns consistlng of cross sections substantially U shaped, and beyond said columns consistlng of cross sections curving inwardly at substantially all points beyond the central median lines thereof, v

4. 'A side frame consisting pf- -an integral casting including tension and compression members and intermediate columns. said tension and compression members between said columns consisting of cross sections substantially U shaped, and beyond said columns consisting of cross sections having a substantially continuous inward curve from their mid point to their inward margins.

5. A side frame consisting of an integral casting including tension and compression members and intermediate columns, said tension and compression members beyond said columns consisting of cross sections.

curving inwardly at substantially all points beyond the central median lines thereof, the tension and compression members also tapering in a horizontal plane toward the ends thereof.

6. A side frame consisting of an integral casting including tension and compression members, and intermediate columns, said tension and compression members beyond said columns consisting of cross sections curving inwardly at substantially all points beyond the central median lines thereof, and. a strengthening portion formed byextending the side Walls of said sections inwardly in a substantially vertical plane in varying depths dependent upon strength requirements.

7. A side frame consisting of an integral casting including tension and compression members, intermediate columns, said tension and compression members beyond said columns consisting of cross sections having a substantially continuous inward curve from their mid point to their inward margins, and a strengthening portion formed by extending the side Walls of said sections inwardly in a substantially vertical plane in varying depths dependent upon strength requirements.

8. A side frame consisting of an integral casting including tension and compression members, intermediate columns, said tension and compression members beyond said columns consisting of-cross sections each having its inner surfaces curving inwardly continuously from the central line thereof toward its lower margins, the side walls being thicker with their outer surfaces eX- tended outwardly in a substantially vertical plane and the outer portion curved concentric with said inner surface.

9. A side frame consisting of an integral casting including tension and compression members and intermediate columns, said tension and compression members between said columns being substantially U sha ed in cross section and merging into sections having their outer portions of increased inward curvature respective to the U shaped sections intermediate said columns.

10. A side frame consisting of an integral casting including tension and compression members, intermediate columns and journal boxes at the ends of said members, said ten sion and compression members between said columns consisting ofcross sections curving inwardly at substantially all points beyond .the central median lines thereof, and having through .the respective cenlines passing of said members lntersectmg ters of mass points substantially above the center line of the axle boxes.

In Witness whereof, I hereunto subscribe my name this 16 day of November, A. 1)., 1923.

cnoner. s. CHILES.

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