Wheel adaptor device

An adaptor bolt to permit fitting wheels having a given bolt hole circle diameter to wheel studs having a different circle diameter. The kit is made up of a plurality of adaptor bolts each comprising an internally threaded bore located eccentrically in the bolt with respect to its external threads. The internal threads fit on the studs and cap nuts fit on the external threads to mount the wheel on the adaptor bolts. Friction increasing means are provided on the internal threads to hold the adaptor bolts in various adjusted positions defining different diameter bolt circles.

This invention relates to the automobile industry, and in particular to the 
use of automobile wheels. By the use of this invention wheels having a 
given bolt hole diameter may be fitted to hubs having bolt circles of a 
different diameter. 
As is well known, this is particularly true for American made automobiles, 
the bolt circles on the wheel drums of full-size Fords, Chevrolets, 
Oldsmobiles, and the like vary slightly, so that a wheel designed for a 
Chevrolet will not fit the bolts on the wheel drum of a Ford or of an 
Oldsmobile. The same is true for many of the smaller makes of cars, and 
this situation obtains not only for 5-bolt wheel drums, but also for 
4-bolt wheel drums. In this connection it may be noted that the standard 
Ford wheel drum has a bolt circle of 41/2 inches, the Chevrolet 43/4 
inches, and the Oldsmobile, 5 inches. 
It is an object of this invention to provide an adaptor kit or device which 
will permit fitting a wheel having holes pre-drilled in a certain bolt 
circle pattern, to fit either Ford, Chevrolet, or Oldsmobile, or 
intermediate bolt circles. The utility of the kit is based on a novel lug 
bolt adaptor with an eccentric internally threaded bore. Said adaptor is a 
main feature of the invention.

Referring again to FIG. 2, the base of the lug nut 3 is shown at 15. This 
base is suitably hexagonal or polygonal, but can actually be any shape 
readily adapted to be turned by a wrench. The base is counter-bored 
slightly at 16, so that the lug adaptor will fit readily over all standard 
bolts, most of which have a collar at the base of the bolt. The internal 
bore of the lug adaptor is shown at 17. The internal threads of this 
internal bore 17 can be of uniform diameter in the case where the template 
ring 12 is used. If the bore is uniform, the lug adaptor will be fairly 
loose on the lug bolts, and they will have to be held in position with the 
template ring or equivalent. When the template ring is omitted lug 
adaptors having compressed internal threadings, at least in a portion of 
the upper threads, should be used to provide a tight frictional fit on the 
lug bolts. This is described in more detail in the section hereinafter 
dealing with "Kit Without Template". 
KIT WITH TEMPLATE 
Referring to FIG. 1, at 1 is shown generally an automobile wheel drum. This 
drum is fitted with bolts or studs, 2. These bolts or studs and drum of 
course appear on any car, and are not a part of this invention. At 3 and 4 
are shown two adaptor lugs of this invention. These lugs are eccentrically 
bored, and the bore is internally threaded to fit the bolts on the drum. 
The upper part of each lug is externally threaded. At 5 is shown an 
adaptor lug in expanded relationship with the bolt 2. Lug 5 is ready to be 
screwed down onto bolt 2. At 6 is shown another bolt, and the dotted lines 
show possible variations of bolt position, 6a showing a bolt having a 
smaller diameter bolt circle and 6b showing a bolt having a larger 
diameter bolt circle. 12 shows a template ring carrying a plurality of 
holes adapted to fit snugly around the base of each lug adaptor when the 
lug adaptors are screwed down onto the bolts and then turned a specific 
amount counter-clockwise (as hereinafter explained). 7 shows a lug adaptor 
in an intermediate position; 7a shows the same lug adaptor turned to 
provide a lug circle slightly larger, and 7b shows the same lug adaptor 
turned to provide a lug circle slightly smaller. In this connection, and 
referring to 7, 7a, and 7b, it will be noted that 7 gives the same circle 
diameter as the pre-existing bolt circle. For example, if the pre-existing 
bolt circle is 43/4 inches, as is the case with a Chevrolet, 7 would have 
the same circle diameter. If, on the other hand, the original bolt circle 
were the Ford bolt circle of 41/2 inches as shown in 6a then the lug 
adaptor would be turned to position 7a, to give a larger diameter circle 
of 43/4 inches. If, on the other hand, the bolt is in position 6b, i.e., 
it has the larger 5-inch bolt circle of the Oldsmobile, then it must be 
rotated to the position shown in 7b to reduce the effective bolt circle 
diameter. 
8 shows a washer, preferable but optional, and 9 shows the capping nut. At 
10 is shown generally in dotted outline a wheel containing a plurality of 
recessed bolt holes 11. 
This kit is used as follows. First the adaptor lugs (i.e., as shown at 3, 
4, etc.) are screwed onto lugs such as those shown at 2. The adaptor lug 
is screwed completely onto the bolt. Then each adaptor lug is rotated 
counterclockwise slightly (generally less than a full turn) so that all 
five adaptor lugs will be in a position exactly to receive template 12. 
Template 12 is then placed over the plurality of adaptor lugs. The holes 
13 in template 12 are pre-formed to be the same circle diameter as the 
holes 11 in wheel 10 (in this example, 43/4 inches). Template 12 is 
sufficiently thick so that the required slight rotation of the adaptor 
lugs (3, 4, etc.) is not sufficient to permit the edge of the template 
holes 13 to slide between the lugs and the wheel drum. Next the wheel is 
mounted on the plurality of lugs. If washers are used (and they are 
preferred), they are then placed into the recesses of the bolt holes 11, 
and the cap nuts 9 are then screwed onto the threaded areas of the lug 
adaptors. This completes the operation. 
KIT WITHOUT TEMPLATE 
In a preferred embodiment of this invention the template ring 12 is 
omitted. This omission is feasible in this instance because the lug 
adaptors (shown generally at 3 and 4) are of a special type in which the 
upper one-third of the internal threads is compressed. Means for 
compressing these internal threads is well known in the machinist art. 
Such compression gives a tighter fit when the lug adaptor is screwed onto 
the bolts, 2. This fit is sufficiently tight that the lug adaptors have to 
be rotated with a wrench. Once rotated to a predetermined selected 
position, however, they remain in that position indefinitely, until again 
moved with a wrench. Accordingly in this embodiment the lug adaptors are 
screwed down tight against the drum plate of the automobile. The last 
turns will have to be made by a wrench owing to the compression above 
mentioned. Then each lug adaptor is rotated counter-clockwise (again, a 
wrench will be necessary) until the proper position is attained. This is 
readily discernible by eye. Then the wheel can be mounted on these lug 
adaptors and washers and lug nuts or caps screwed on with a narrow-wall 
socket tire wrench. 
When using this embodiment, a useful phenomenon generally occurs. When the 
wheel is mounted through its lug holes over the adaptor lug bolts, the 
washers inserted, and the nut caps tightened, a slight clockwise rotation 
of the adaptor lugs may be noted. This results in a further tightening of 
the wheel against the drum lugs. 
While a particularly advantageous embodiment of the invention has been 
described in the text and illustrated in the drawing, it will be 
recognized by those skilled in the art that various changes and 
modifications can be made therein without departing from the scope of the 
invention defined by the appended claims. For example, as should be 
readily apparent to those skilled in the art, the number and thickness of 
the bolts, lug adaptors, number of holes in the template 12, degree of 
ecceentricity in the adaptors, can be varied to meet the needs of any 
particular wheel system. The drawing shows five bolts, but any plurality 
of bolts more or less than this figure can be used, e.g., 4, 6, etc. Also 
the bolt circle diameter can vary substantially from the values given 
below. 
When omitting the template, a special wrench can be used to achieve the 
desired alignment. Such wrench is used as follows. First, the eccentric 
lug bolts are tightened against the drum. Then the bolt is loosened 
approximately one turn, then the special wrench is used to position it. In 
making this positioning, however, the eccentric lug is not tightened up 
completely, because the handle of the wrench is permitted to rest against 
the next eccentric bolt (next in a clockwise sense). The socket space is 
oriented in the wrench such that, taken with the handle width, the 
positioning process will give a quick and exact angular orientation of the 
eccentric bolt to produce the desired bolt circle. Different wrenches can 
be used for different bolt circles, or, if desired, three or more wrench 
molds can be combined into one tool. 
FRICTION RESISTANT PLASTIC PLUG 
In a preferred embodiment of the invention shown in FIG. 6 the adaptor lugs 
(i.e., 3 and 4) are drilled in the side and fitted with a nylon or other 
plastic friction-resistant plug 20. For example, looking at FIGS. 5 and 6 
the adaptor lug is drilled perpendicular to the axis of bore 17. The 
drilling is done about half way up the length of the lug, suitably so that 
the center line of the drilled hole is about 3/32 inch up from the 
beginning of the external threads. The size of the hole (and of the nylon 
plug) can vary, but is preferably about 1/8 of an inch. The hole can be 
drilled at the thin part of the lug, i.e., at the top of the plan area as 
shown in FIG. 4, or at either side (which would be intermediate areas) as 
shown, or at the thickest area which would be through the bottom, again 
looking at FIG. 4. We prefer, however, that the hole be drilled through 
the side, since this appears to give an adequate size plug without 
excessive drilling and also provides the frictional resistance which is 
the purpose of the plug. The plastic plug is permitted to extend slightly 
into the interior of bore 17 as shown, where it will make contact with the 
threads of the lugs 2 on the wheel drum, 1. Plastics other than nylon can 
be used. This type of frictional plug is well known in the art, and is 
described, for example, in U.S. Pat. No. 2,725,915. Apparently, however, 
it has never before been described or used with an eccentric lug nut for 
vehicle wheels. 
When using the plastic plug embodiment it is not necessary to use template 
12. The adaptor lugs are readily positioned in the following manner. First 
of all, they are screwed finger tight onto the drum lugs. Then they are 
screwed down with a wrench to the drum base. Then they are turned back 
counterclockwise until they are turned to the correct adapting position 
for the wheels to be mounted. Frequently there will be only two positions 
requiring consideration, one with the thick part of the adaptor lug 
pointing outward, and the other with the thick part of the adaptor lug 
pointing inward. These positions are readily determined by visual 
inspection. Open wrenches of the spark plug type can be used for rapid 
adjustment. If desired, for convenience the T-bar of such wrench can be 
marked to point in the direction of the thick part of the adaptor lug, 
when putting the wrench on the lug, so that orientation of the lug will be 
at all times evident without removing the wrench for inspection. The nylon 
plug 20 will hold the thus adjusted adaptor lugs in good steady position 
until the wheel is mounted on the drum. Theoretically an infinite number 
of intermediate positions between the thick area pointing out and the 
thick area pointing in are achievable by this means. For purposes of 
simplicity only the two extremes have been described. 
FIG. 7 shows a compressed thread zone 30 in a lug 3A. The lines 32 show the 
undistorted shapes of the threads in zone 30. The solid lines, aided by 
the pitch lines 34 and 36, show the compression. An interference or 
increased friction fit on the bolts or studs 2 (FIG. 1) will occur at the 
compressed thread zone 30. The distortion of the external threads in zone 
30 has no effect on the normal use of lug 3A because zone 30 is relatively 
small as compared to the total external thread area. However, this zone is 
sufficiently large as to the internal thread's total area that it does 
have the desired friction increasing effect on the bolt. 
While the invention has been described in detail above, it is to be 
understood that this detailed description is by way of example only, and 
the protection granted is to be limited only within the spirit of the 
invention and the scope of the following claims.