USRE18176E - Bkake drum construction - Google Patents

Description

sept.y 1, 1931. E. A. NELSON Re. 18,176

`BRAKE DRUM CONSTRUCTION original 'Filed April 1e. 192s 2 Smets-sheet 1 INVENTOR Emil /Ye507v.

ATTORN EY.

Sept. l, 1931. E. A. NELSON BRAKE DRUM CONSTRUCTION 2 sheets-sheet 2 l Original Filed April 16, `1928 v www a ma n T5 v N md VN T N T ,TH A

Reissud Sept. 1i, `19311 Re.' v18,116

FFICE f EMIL'A. NeLsoN, or DETROIT, MICHIGAN BRAKE DRUM CONSTRUCTION D v l u l I riginal No. 1,750,682, dated March 18, 1930, Serial No. 270,179, led Apri1'16, '1928. Application for reissue filed September 23,

This invention relates to brake drums and particularly to a type suitable for use on nio-- tor vehicles, the principal object being thel provision of a new and novel construction for the same.

Another object is to provide a brake drum construction that will be veconomical to produce'andeiicient in operation.l

Another Objectis to provide a brake drum construction that will not be subject to distortion under braking Jpressure or because of yheat.` V

Another object is to provide a vbrake drum construction in which the brake drum is of substantially identical section on either side of a plane passing centrally therethrough and perpendicular to its axis.

A further object is to provide a brake drum of ring-like form supported substantially n midway between lthe side edges thereof.V

` The above being among the objects of the present invention, the saine consists in certain features of construction and combinations of parts to be hereinafter described `with ref- 85 erence to the accompanying drawings, and then claimed,` having the above and other objects in View. p l Y In the accompanying drawings which il. lustrate suitable embodiments of the present invention and in which like numerals referr to like parts throughout the `several different views,.- Y

Fig. 1 is a partially broken edgeview of a conventional wheel and brake drum construction. J 4Fig. 2 is aview similar to Fig. 1 but illustrating one form of my improved brake drum construction in connection therewith. Fig. 3 'is a view similar to Fig.`1 but ilev o lustrating another modification of my improved ,brake drum construction in connec` tion therewith. 1

Fig. 4 is another view"similar to F ig. 1 showing a further modification of my present invention in connection therewith.

a wheel for heavy vehicles, such as trucks and the like, in connection with which a still' modified form of my present invention is.

`hub 14 by being clam ed betweenthe same 1930. Serial No. 483,961.

y shown, the rims for the wheel being shown in section.

Fig. 6 is a fragmentary sectional view takenon the line 6 6 of Fig; 2.

F ig 7 is a fragmentaryA sectional 'view taken on the line 7-7 of Fig. 3. n the conventional form of brake drum construction, as illustrated. in Fig.` l, the brake'drum comprises a disc-like supporting portion 10, a cylindrical brake shoe or brake band engaging port-ion 11 carried Aby the portion 10 and extendinglaterally in one direction therefrom, and av peripheral radial ianged portion 12 provided to impart strength to the outer edge of the portionv 11. The drum may be secured to a( wheel infva' rious manners,- the method shown being c0nventional `and in which the disc portion 10 1s secured against the ilange 13 of the wheel andthe Wheel disc 15 y means of the bolts 16.` The wheel disc 15 carries the usual rim 17 `and co-operatihg lock ring,18. A brake shoe 19 which may be of any conventional construction is adapted to en age the inner side of the portion 1-1 of the rum upon a plication of the brakes through suitab e mechanism (not shown). A dustshield 20 carried b the axle housing 21 is conventionally emp oyed to protect the interior of the brake drum from dust and other foreign` matter. In this type of brake-mechanism, which is conventional, when the brakes` are applied so as to force the shoes 19,'out into contact with the portion 11 ofthe drum,

tort. This is due to the fact that the disc portion 10 of the drum is oifsuch extreme of the ortion 11,- is prevented from radially expan ing, while the opposite' edge of theportion 11 which is reinforced against ra- -dial expansion .only by the relatively small 'flange 12, is relatively weaker and conse- .I quentlyjs expanded 'an amount suflicient toj- Fig. 5 is a .partially broken side-vlew ofv Athere is a tendency for the lportion 11 to discoiicentrate the pressure betweenJ the po1`- plication of@ the brake. This concentration ofpressure causes an unduewearl of both the' drum and the friction linin of the shoes 19 at the inner edge of the portion 11 during ordinary brake applications, and as is well known to those skilled in the art, such concentration of pressure over a relatively limited area is conducive to squealing brakes and scored drums. pressure will, of lcourse, vary with a particular severity of the brake application in any particular case, as. will the deforming of the portion 11, so that it is practically impossible r for the brake shoes to wear toa point where the will equally engage the drum' for all bra e applications of varying intensity. Furthermore, with the conventional construction, as illustrated, ywhere there is a g of thebrakes at hi'gh speed, or; a continued dragging of the brakes, a severe application application of the brakes such as in descending a mountain, so as to cause the brake drum to become heated, the portion 11 in becoming heated expands' with the flange 12 to a relatively greater extent than the portion with the result that the deformation of the portion 11 is increased. -That is, the inner edge is held against expansion by the portion 10 and the outer edge in expanding' to-a greater diameter, causes the portion 11 to assume the shape of a fru'stum vof a cone, and

Y this deformation is in addition to the. deformation caused by the expansive pressure ylili and lhard to control.

of the brake elements prevlously described.

vThe fact that the heat generated due to the braking action does not iiow evenly both ways from the braking surface, but rinci- :p'ally towards one side only thereof, urther explains the unequal expansion vof the drum. This deformation caused by heating of the portion 11 aggravates the deformation due solely to the pressure of the brake elements against it, as first described.

One of the methods of correcting these disadvantages has been `the increasing ofI the" dimensions of the flange '12, but inasmuch as this is usually limited by clearances necessar in such constructions and because of thediiculties experienced in drawing operations, the dimensions of the flange l2 are necessarily limited. The drums themselves have been increased in thicknesslasfar as is practical, but due to the modern tendency of' orming such drums from highl carbon steel in order to 'avoid scoringand wear, the prac tical limits of thickness 'are relatively small 'due to the fact that with such steel, drawing. of the metal becomes extremely diicult Forging ofsuch drums is, of course, impractical in mass production because of the expense involved.

By the use of the present invention I provide a brake drum construction which will deu form but little, if any, under temporar application of the brakes, and, if. at all, uni ormly, Aand when heated by continuous applica- The concentratlon of suchv surface for contact with the brake elements.`

One form of my improved brake construction is illustrated in Figs. 2 and 6. In these figures, the hub 14, wheel 15 and housing 21 are identical with. the construction in Fig. l. The brake drum, in this case, instead of bei-ng the conventional integral construction, as shown in Fig. 1, is-made up of two major parts, a drum portion 22 anda supporting portion 23. The supporting portion 23 is similar to the portion 10 of the conventional brake drum land is secured to the hub 14 in the same manner, but insteadof being provided with the cylindrical portion 1l, it is provided with a plurality of separate spaced fingers 24 which extend laterally outwardly therefrom. The portion 22 which forms the brake drum proper is provided with a cylindrical inner surface and a plurality of radially extendin circumferential ribs 25, the particular em odiment showing the provision of `four of such ribs, the two center ones of which extend outwardly from the portion 22 to a slightly greater extent than th-e marginal ribs. The two center ribs 25 are recessed as at 26 in Fig. 6, in line with each one of thefingers 24 and such fingers are received within the recess 26 and are welded or otherwise suitably secured therein. Except at the points where the fingers 24 are secured to hthe two center ribs 25, the supporting portion 23 and fingers v24 are freely spaced from the brake drum 22. The brake drum 22, in this case, may be formed to the Section shown by a hot rolling process and employing a relatively high carbon steel whereby the finished brake drum isof maximum hardness and strength, or it may be of cast construction.A It will be apparent that with this construction, the radial pressure of the brake shoes 19 in their application to the drum 22, will cause equal radial expansion of the drum 22 throughout its width due to the fact that the section of the drumA 22 is identical on either side of a plane passing through .its center and perpendicular to its axis, and it will be further apparent that heat generated during a braking action will be distributed equally on both sides of the central plane of the drum and any expansion of the drum 22 due to heat will likewise be evenly distributed throughout the width of the drum 22. lhen any such deformation or expansion occurs, the fingers 24 will easilv give a sufficient amount to permit such expansion without exerting an undue resistance to -such expansion.

In Fig. 3, a modified form of my invention is shown which is applicable to smaller installations. In this construction, the supporting portion 23 is provided with a plurality of fingers 27 arranged similar to the fingers 24 previously described, but in this case each of the lingers 27 is provided with laterally extending arms 28 which-are offset radially inwardly from the'main portion of the arms 27a slight amount as indicated in "the fingers 27 then bent into normal position Fig. 7 The brake drum 29, in thiscase for A the sake of economy, is formed ofsheet metal as indicated in Fig. 3, to provide a cylindrical portion and a pair of radially extending peripheral marginal flanges 30. The lateral portions 28 of the arms 27 are bent into contact with the cylindrical portion of the brake drum 29 midway between thel flanges30, as

'indicated in Figs. 3`and 7, and are then secured to such portion by rivets such as 31 or other suitable means. y In assembling'the portions 23 and brake drum 29 together, the arms 27 may be first bent out of their normal position, as indicated in dotted vlines in Fig. 3, the brake drum 29 inserted between them and and the lateral flanges y28 secured to the brake drum, as described.

tending fingers against movement.` The effect of this' con- -struction'is substantially the same as those previously described except that perhaps the brake drum 32 may be less affected by any resistance set up by the bending of the fingers 35 during expansion of the drum 32.

In Fig. 5, a modification of the'present invention is shown applied to a wheel such as' may be employed on trucks and like heavy vehicles. f The particular construction of the wheel and rims are those shown and described in my Letters Patent of" the United States dated 'J an. 28, 1930, and numbered 1,744,915, and comprises essentially a wheel having a hub 37, and four radially extending integral spokes 38 each terminatingin a` separate rim .supporting seat 39. The rims 40 are provided with enlarged laterally offset attaching and supporting portions 41 which' are adapted to be secured to the various seats'39 by radially extending bolts (not shown). y

In' the particular embodiment shown in 4Fig.'5 each of the four seats 39 are `rovided with. a laterally extending arm or nger 42 which serve the same purpose as the fingers 24, 27 and 35, previously described. Thebrake drum 43 may be formed of cast or hot rolled section and secured to the various fingers 42 by means of screws 43 or other suitable means. This provides an extremely cheap and efficient construction for such type f Wheels.

It will be apparent that underalmost any `conceivable range of expansion or contraction y device is that oil and Water integrally formed therewlth fingers secured to said ring of the drums 22, 29, 32 and 43 from the causes described there will be insujiicient movement of the drum to bend the respective supporting arms 24., 27, 35 and 42 an amount sufficient to set up stresses Within the arms which will exceed the elastic limit of the metal from which they are formed, when such metal is of the type usually found in such constructions. It will be further apparent that should any danger of a permanent set in the arms arise because of possible excessive bending from such expansion of the drum, the arms may be formed of spring material ,having a high elastic limit to obviate such possibility, and be secured to their respective supporting portions in any suitable manner.'

From the above it will be apparent that the present invention discloses a brake drum construction in which the deformation prevalent in the conventional forms ofbrake drums is eliminated, and that a construction is provided in which the brake shoe or brake band engaging portion of the drum may be formed of any desired material and at a cost that Willcompare very favorably with the cost of conventional constructions. y

An additional advantage inherent in my matically ejected and the braking surface is thereby kept clean. The reason for Lthis is and dirt are autol that the braking surface is mounted at some distance from the cage and this supporting cage is perforated,l centrifugal force therefore causing any oil and water to be thrownv through the 'perforationsV away `from the braking surface.

Formal changes may be made inthe specific embodiment of the invention described without departingfro'm the spirit o r substance of the broad invention, the scope of which is commensurate with the appended claims.

What Iclaim'is:

l. In combination, abrake'drum construction comprising a ring open on bothsides and supported by radially yieldable lateral independently of the edges thereof. V l

2. lIn combination, a brake drum construction comprising a ring having a cylindrical surface and of substantially equal strength, on either side of a plane passing through its center perpendicular to its axis, and means for supporting said ring comprising radially yieldable members secured to said ring independently of the edges thereof.

3. In combination, a brake drum construction comprising a ring having a cylindrical surface and of substantially equal strength on either side of a plane passing through its center perpendicular to its axis, and means for supporting said ring comprising radially yieldable members, secured thereto centrally of the side edges thereof. t

4. In combination,a brake drum comprising a ring provided with marginal stiffening flanges supported by laterally! extending yiel able su porting means.

5. In com ination, a brake marginalfianges extending therefrom in the same direction from both edges, and yieldable means supporting said ring from points between said flanges. l 6. In combination, a brake drum construc- 'tion comprising a ring" having one face in the form of an uninterrupted cylinder and the opposite-face provided with at least one radially extending ribbetween the edges thereof, and radially yieldable means secured to saidrib for supporting said ring.

7. In combination.y a brake drum construction comprising a disc-like member provided adjacent its periphery with laterally extending ngers, and a ring supported by said fingers in a planesubstantially parallel with the plane of said disc.

8. In combination, a brake drum construction comprising a disc-like memberprovided adjacent its periphery with laterally extending fingers, means connecting the outer ends of said fingers, and a ring supported by said means.

9. In combination, a brake drum construe' Ytion comprising a disc-like member provided with laterally extended fingers, the outer ends of said lingers being connected together, and a. ring carried by said fingers in a plane parallel to said disc-like member.

10. In combination, a brake drum construction comprising agenerally circular member, an open ended ring positioned in concentric relationl thereto, and fingers integrally formed on said member connecting said member and said ring.

1l. In combination, a brake. drum construction comprising a generally circular member, an open ended ring positioned `in concentric ,relation thereto, lingers 'fixed to said member and projecting"therefrom towards said ring, the outerends of said fingers being joined together, and said ring-being supported independently of itsI edges through said fingers. i 1 A composite brake device comprising a stamped steel drum having a relatively 10W carbon content including an annular portion and a web portion, said steel drum having pcrforatons between the web and annular portions, a se aratc cylindrical portion conf stituting the reaking surface supported independently of its edges on said annular portion of the stamped steeldrum.

13. ,A .composite brake device comprising a stamped steel drum having a relatively low 2 carbon contentincludi-ng anannular portionr y and a web portion, said steel drun'r'haying perfoiations between the web and annular portions,and a separate cylindrical portion constituting the brake surface having a central circular rib on the side opposite to said brakdrum compris-t ,ing an open ended ring provided with radial cluding a web and an annular portion, and a separate imperforate cylindrical portion containing the braking surface connected to the -annular portion of the stamped steel drum.

. 11'5. A perforated stamped metal drum including a web portion and an annulus, and an open ended cylidrical portion separated therefrom andl connected to the annulus intermediate the edges of said cylindrical portion.

18. A stamped metal drum including an annulus and a web, an open ended circular drum having a circular rib intermediate its edges, said circular rib being connected to said annulus. y

19. The combination with an openlended drumfor an internal brake mechanism, of means annularly interlocked with and supporting said drum, said connecting and supporting means permitting contraction or expansion of the drum without substantial distortion thereof.

20. In a brake structure a brake drum having an interior braking surface for an internal brake, and supporting means therefor yieldably supporting said drum.

21. In a brake, an open ended brake drum for an internal brake, and supporting means therefor for externally supporting said drum and having a yieldable connection therewith.

22. In an internal brake structure, the combination with a brake drum, means for externally supporting said drum, said means including a yieldable connection with the drum to permit expansion thereof without substantial' distortion. j

23. A composite brake device comprising va stamped metal drum and a ring providing a to the hub of a wheel comprising, in combination, an annulus provided with a braking surface concentric with said 1mb and wheel, and

16. A perforated stamped metal member including a web and an annulus, and an open ioo iio

a drumlike member supporting said annulus Within its circumference by engagement therewith independently of the edges thereof, said member adapted to be secured diingers on said member engaging said annulus e endently of its edges, thereby to support it re ative thereto.

27. A braking device adapted to be secured directly to the hub of a wheel, comprising, in combination, an annulus provided with a braking surface, and means for supporting said annulus directly from said hub comprising a drum-likemember secured to said annulus between the edges thereof and having open perforations in its circumference independently of said braking surface.

28. A brake device comprising a drum and va ring, said drum comprising an annulus and a web secured to one end thereof, said ring having an interior braking surface and being received within said annulus and secured thereto between its edges, and ventilation openings in said drum spaced from said braking surface.`

29.` In combination, al perforated stamped metal drum including a web portion and an annulus, and an open ended ring provided with a cylindrical braking surface and an annular rib intermediate its edges, said annular rib being connected to said annulus, andthe ends of said ring being radially spaced from said annulus. Q

30. In a brake device, in combination, a

ring having a cylindrical braking surface and a radially eiitending annular rib on the face opposite thereto, and a support for said ring comprising a sheet metal memberextending toone side of said ring and having ,a port-ion thereof embracing opposite sides of said rib.

31. In a brake device, in combination, a

ring having a cylindrical inner braking surfaee, "a circumferentially extending rib disposed between lhe edges of said ring on the outer face thereof, and a drum comprising a Web and an annulus closinflr one side of said ring, said annulus embracing both sides of said rib.

32. A brake device comprising, in combination,l an inner shell of rolled steel T-section havingaa broad top and a short centrally disposed rib, and an outer shell disposed in coneer'itric relation with respect to said inner shell` and embracing both sides of said rib.

33. A brake devicey com rising, in combination, an inner shell o relatively high carbon rolled steel having abroad top and,

a short central rib,`and a stamped low carand an annulus, said annulus having an annular inwardly opening channel therein, and

a ring having an inner cylindrical brakingV surface and an outer annular rib disposed Within said drum with said rib received in said channel.

36. A brake drum structure including an annular braking ring having an interior braking surface and a radially yieldable supporting annulus for said ring annularly interlocked therewith.

37. A brake drum structure including an annular braking ring having an interior braking surface and a radially yieldable disc structure supporting said ring serving as a head for said drum structure and annularly interlocked therewith. t

38. A brake drum structure including any annular braking ring having an interior braking surface and means for'exteriorly yieldably. supporting said ring annularly interlocked therewith.

39. Abraking device adapted to be secured directly to the hub of a wheel comprising, in combination, an annulus provided with a cylindrical braking'surface concentric With said wheel, and means adapted for rdirect' securement to said hub engaging said annulus independently of .the effective braking surface edges thereof and at least partially independently of the Vsupport for said Wheel.

EMIL A. NELSON.

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