US3049379A - Wheel and brake drum assembly - Google Patents

Description

Aug. 14, 1962 T. L. HIBBARD WHEEL AND BRAKE DRUM ASSEMBLY Filed Jan. 12, 1959 INVENTOR.

rwamns A. fi/asnk United States Patent 3,049,379 WHEEL AND BRAKE DRUM ASSEMBLY Thomas L. Hibbard, Birmingham, Mich., assignor to Kelsey-Hayes Company, Detroit, Mich, a corporation of Delaware Filed Jan. 12, 1959, Ser. No. 786,244 2 Claims. (Cl. 301-6) This invention relates to wheel and brake drum assemblies and refers more particularly to a wheel and brake drum assembly of the type in which the wheel structure is mounted on the brake drum.

The invention has for one of its objects to provide a wheel and brake drum assembly in which the wheel structure is mounted on the brake drum and the web of the drum is mounted on a rotatable member by fasteners which are concealed by the web when the assembly is viewed from the outboard side.

The invention has for another object to provide a wheel and brake drum assembly in which the wheel structure is mounted on the brake drum and the web of the drum is mounted on a rotatable member in a manner such that the web serves the additional function of a wheel center and is exposed on the outboard side to present a wheel body appearance.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing, illustrating a preferred embodiment of the invention, where- FIG. 1 is a fragmentary radial section of a wheel and brake drum assembly embodying the invention; and

FIG. 2 is a fragmentary elevation with the hub cap removed, looking in the direction of the arrow II in FIG. 1.

Referring now more particularly to the drawing, 1 is the brake drum and 2 is the wheel structure. The brake drum is a cast element in the form of a shell having the integral web 3 and annular flange 4 extending along the radially outer periphery of the web and projecting in an axially inward direction or to the left as viewed in FIG. 1. The shell is cast of aluminum or magnesium, which are relatively light in weight and have high heat transfer characteristics. While aluminum or magnesium are preferred, other materials may be employed. The annular flange 4 is formed with a series of circumferentially spaced heat dissipating ribs 5 cast integrally with the flange. The web 3 has an outer annular radial portion 6 upon which the wheel structure is mounted, and an inner bolting-on portion 7 flaring from the radial portion radially inwardly and axially outwardly. The web has a central circular opening 8, and an annular hub cap retaining formation 9 projecting axially outwardly from the web near its inner margin. The formation 9 defines a central circular opening 10 adapted to detachably receive a hub cap 11. The hub cap is fitted within the opening 10 and may have a threaded or snap engagement therewith or any other readily detachable form of connection. Equally spaced radially extending heat dissipating ribs 12 are cast integrally with the web on the outboard side thereof.

An annular cast-iron liner 13 is secured to the inner surface of flange 4 for engagement by a suitable friction device, not shown. The brake drum shell may be formed by casting in a sand or permanent mold or by die casting, for example. Preferably the liner 13 is placed in the mold prior to casting and the brake drum shell is cast around the liner. During casting of the shell, a molecular bond is obtained between the liner and shell flange throughout the full 360 of contact. The procedure employed for bonding the liner to the flange forms no part of the present invention and is fully described in an ap- 3,049,379 Patented Aug. 14, 1962 flange with a plurality of equally circumferentially spaced axially outwardly projecting wheel mounting bosses 14 which terminate in radial faces. The bosses are formed with the axially extending sockets 15 open at the axially inner side of the web and having bolt holes 16 in the bottom Walls of the sockets. In the present instance, bosses are provided in each alternate space between adjacent ribs 12.

The wheel structure 2 comprism an annular tire rim 17 and mounting tabs 18. The rim 17 encircles the brake drum and is formed with a well 19. The tabs are spaced apart circumferentially with respect to the rim equal distances corresponding to the spacing between the wheel mounting bosses 1.4, and each tab has a generally axially extending portion 20 welded to the bottom wall of the rim well 19. Each tab also has the radially inwardly extending portion 21 which is adapted to overlie a boss 14 and which has a central raised part 22 formed with a hole 23 registering with a bolt hole 16. Fasteners are provided comprising bolts 24 which extend through the registering holes 16 and 23 with the heads 25 of the bolts seated against the bottoms of the sockets 15, and nuts 26 are threaded on the outer ends of the bolts and bear against the tabs to draw them firmly against the radial surfaces of the bosses 14. Each bolt 24 is serrated near the head to provide a gripping engagement with the hole 16 frictionally resisting axial movement or rotation of the bolt relative to the drum and enabling tightening and loosening nut 26 from the outboard side without otherwise holding the bolt. The bolts extend freely through tab holes 23 for mounting and demounting the wheel structure. By means of the tabs 18, bolts 24 and nuts 26, the rim is detachably secured to the brake drum so that the web of the drum serves the additional function of a wheel center and the nuts are accessible from the outboard side of the assembly for mounting and demounting the wheel structure.

A pluraiity of fasteners 27 are provided for detachably mounting the wheel and brake drum assembly on the flange 28 of the rear axle 29. The bolting-on portion 7 of the web is formed on its inboard side with a circular series of spaced sockets 30 which are closed at the "bottom and have permanently secured therein the cylindrical fastener elements or nuts 31 which are internally threaded. The axle flange is formed with a circular series of openings 32 spaced apart so as to register with the nuts 31. The fasteners 27 also include the cap screws 33 which are adapted to extend through the openings 32 and threadedly engage the nuts 31 to detachably mount the web and hence the wheel and brake drum assembly on the axle flange.

During assembly, the brake drum is positioned on the axle with the nuts 31 in register with the axle flange holes 32 and the cap screws 33 are then fitted through the flange holes and threaded into engagement with the nuts to draw the web of the drum tightly against the axle flange. Access to the cap screws 33 for this purpose may be had through the usual brake backing plate, not shown. Thereafter the bolts and nuts 24 and 26 are employed to detachably mount the wheel structure on the drum.

The nuts 26 are accessible from the outboard side of the assembly so that the wheel structure may be readily mounted and demounted. The fasteners 27 composed of the nuts 31 and cap screws 33 are neither visible nor accessible from the outboard side of the assembly and hence a person changing a wheel will not inadvertently remove the brake drum. The web of the drum is exposed on the outboard side and presents an attractive wheel body appearance. Moreover the heat dissipating ribs 12 are exposed for maximum cooling.

The illustrated detachable connection between the brake drum web and axle flange enables enhancing the outboard appearance of the web since it may be extended radially inwardly beyond the nuts and cap screws 31 and 33 to provide the relatively long radial ribs 12 and requires only a small hub cap. In other Words, a relatively large diameter hub cap is not required for the purpose of covering the means for mounting the assembly on the axle flange.

As pointed out above, the drum shell is preferably formed of aluminum or magnesium because of the high heat transfer characteristics of these materials. The web and ribs 12 are exposed on the outboard side for maximum cooling effect. Moreover, the exposed web gives the appearance of a full aluminum wheel, where aluminum is uscd.

What I claim as my invention is:

1. In a wheel and brake drum assembly, a brake drum of high heat conductivity material having a generally radial web and an annular flange along the radially outer periphery of said web, a wheel structure including a rim encircling said brake drum and mounting tabs secured to and extending radially inwardly from said rim in overlying relation to the outboard side of the radially outer portion of said web, threaded fastening elements accessible from the outboard side of the assembly extending through registering apertures in said radially outer portion of said web and in the overlying tabs for detachably mounting said wheel structure on said web, and fasteners for detachably clamping said web to a rotatable member, each fastener including cooperating engaging threaded elements one of which is fixed to the inboard side of said web radially inwardly of said tabs, the material of said web covering and concealing said fasteners when said assembly is viewed from the outboard side and rendering said fasteners substantially inaccessible from the outboard side, said web having an integral extension projecting radially inwardly beyond said fasteners provided with means for detachably holding a cover member, said web serving the additional function of a wheel center, the outboard side of said web, including the integral extension thereof and except for the portions thereof overlain by said tabs, being exposed for maximum cooling and to present a Wheel body appearance.

2. The structure defined in claim 1, wherein the said one element of each fastener is an internally threaded member and provided in a socket in said web, said sockets being open at the inboard side of said web and extending axially from their open ends terminating at the bottoms thereof short of. the outboard side of said web so as to be covered and concealed by the material of said web between the outboard side of said web and the bottoms of said sockets.

References Cited in the file of this patent UNITED STATES PATENTS 1,439,269 Siddeley Dec. 19, 1922 1,473,406 Harroun Nov. 6, 1923 1,602,560 Wahlberg Oct. 12, 1926 1,846,236 Wagenhorst Feb. 23, 1932 1,964,129 Miller June 26, 1934 2,095,054 Burger Oct. 5, 1937 2,205,323 Tinnerman June 18, 1940 2,400,348 Greene May 14, 1946 2,402,743 Firth June 25, 1946 2,409,516 Rosenthal Oct. 15, 1946 2,693,392 Grosch Nov. 2, 1954 2,728,370 Neuscholz Dec. 27, 1955 FOREIGN PATENTS 498,058 Great Britain M Jan. 3, 1939 857,160 Germany Nov. 27, 1952 1,056,131 France Oct. 21, 1958

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