A bidirectional odometer having preset features is disclosed. It further includes means for scaling the rate of counting. It incorporates a set of three, four, five or six decade gears of counting gears having numeric indicators thereon and a variable input. The gears are locked together in a sequential chain. The chain can be broken by moving retractable idlers which are moved away to permit repositioning. The device further includes an adjustment controllably locating a multiplier on positive or negative sides of a lead screw to obtain ascending or descending counting. It further incorporates a power take-off drive for rotation of the gear chain from a speedometer cable or the like.

BACKGROUND OF THE DISCLOSURE 
This apparatus is directed to an adjustable and presettable odometer which 
counts in ascending or descending order. In driving the highways of this 
country, one will often notice the mileage posts which are adjacent to the 
side of the highway for indicating the mileage from a point of entry on 
the highway to some point where the highway either begins or terminates. 
Such an arrangement is of great benefit to a traveler. However, a traveler 
normally does not utilize these mileage markers fully because his path of 
travel will not precisely coincide with the locus of the mileage markers. 
For instance, a given highway may have upwards of one thousand miles 
measured and marked with individual mileage markers, while the traveler 
may use only 238 miles of that highway. Moreover, the traveler may be on 
the highway on a given date, traveling where the markers are in ascending 
order, and, on his return trip, the markers will then read in descending 
order. The traveler is thus required to exercise certain arithmetic 
conversions by adding in or subtracting out base numbers to convert the 
mileage marker system to conform with his specific needs and requirements. 
Sometimes, the arithmetic is conveniently easy, but, more often than not, 
it is not so easy that it can be done in the head of a person viewing the 
mileage markers, and, quite often, no benefit whatsoever is obtained from 
the mileage markers. 
The present invention is an apparatus which more readily utilizes the 
mileage markers. It is an odometer which can be set to match mileage 
markers. Moreover, it accommodates mileage markers or kilometer posts, 
also. It should be recognized that most highways are presently marked in 
mileage utilizing the English set of units, but this is probably going to 
change in the near future so that many highways will be marked in 
kilometers. Indeed, the advent of the metric system in this country is a 
foregone conclusion; it is the awkward, in-between time when the 
difficulties arise with converting back and forth between English and 
metric units. The present invention is an odometer which can measure 
distances in English or metric units. The apparatus accomplishes scale 
conversion so that the output can read in any arbitrary type of unit 
desired. Accordingly, the present invention yields an odometer which is 
presettable to any specific number. It is able to count up or down towards 
any other number. It can count by any scale measure so that it will 
accommodate both metric or English units of measure. Lastly, it is a 
portable, removable device to be used with any vehicle desired. 
BRIEF DESCRIPTION OF THE DISCLOSED EMBODIMENT 
The present invention is disclosed as incorporating a base plate for 
mounting of certain equipment thereon. It incorporates a threaded lead 
screw having threads of opposite hand at opposite ends thereof. The lead 
screw carries traveling nuts on it. It is rotated to implement a change in 
scale. It adjusts a follower, and the follower, in turn, moves a drum. The 
drum, itself, is mounted on a shaft so that the two rotate together, and 
the shaft is, in turn, provided with a fitting. The fitting is a power 
input point for connection to any kind of rotating drive shaft which is 
proportionate to vehicle speed in the same fashion as speedometers 
operate. 
The rotating drum is friction engaged with a follower, and it rotates the 
follower in proportion to the rate of rotation of the speedometer drive 
shaft and the setting implemented through the lead screw. The sign or 
polarity is adjusted at the lead screw by use of positive and negative 
traveling nuts mounted on it. The driven drum is connected to 
incrementally advanced decade drive gears having two, three, four or more 
decades, and they are, in turn, connected together through suitable idler 
gears. All of the idlers as a unit can be disengaged so that the gears can 
be reset to achieve a selected beginning point.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
In the drawings, the odometer of the present invention is identified by the 
numeral 10. As shown in FIG. 1, it incorporates a base plate 11 which 
supports the apparatus of interest. Beginning at the lefthand end of the 
apparatus, two upstanding tabs 12 and 13 support an elongate lead screw 
14. The screw 14 is threaded in one direction at one end and is threaded 
in the opposite direction at the other end. The lead screw 14 positions 
two traveling nuts identified by the numerals 15 and 16. The traveling 
nuts 15 and 16 are moved toward or away from one another. The screw 14 is 
locked by an end washer in at the tab 12 and, thus, is free to rotate. A 
knob 17 is incorporated at the opposite end for rotation of the shaft. The 
knob 17, when rotated, adjusts a scale factor, as will be described. 
The traveling nuts 15 and 16 are identical in construction and are 
preferably located at identical distances from the centerpoint. There is a 
center or neutral point on the lead screw 14 where no advance can be 
achieved. This corresponds to multiplication by zero, as will be 
described. Away from that point, the traveling nuts 15 and 16, moving on 
top of the base plate 11, implement differing and larger scale factors, 
one providing a positive value and the other providing a negative value. 
This helps the equipment to count up or down as required. The traveling 
nuts 15 and 16 are each provided with slots or grooves 18 on the top face. 
The slots or grooves serve as alignment means for a follower mechanism. 
This will be discussed in detail hereinafter. As shown in FIG. 3 of the 
drawings, the traveling nuts extend fairly tall above the base plate 11, 
and, coupled with the slot mentioned above, they enable a follower to be 
aligned with the selected traveling nut. The follower includes a narrow, 
thin spline 21 on an elongate frame member 20. The frame member 20 is 
generally rectangular in construction, incorporating the narrow edge 21 on 
the bottom side at one end. A protruding, overhanging lip 22 serves as a 
hand hold so that the follower can be positioned by engaging or 
disengaging it with the slot or the groove in the traveling nuts 15 and 
16. The frame member 20 is elongate and functions as a lever to couple 
motion between components. 
The elongate member 20 is split at the lefthand end so as to encompass a 
rotated drive wheel 25, better shown in FIG. 4. There, the follower is 
shown to be divided into two parts at 26 and 27. They bracket the driven 
wheel or drum 25. 
A nonround shaft 30 passes through the wheel or drum 25. The drum 25 is 
keyed to the shaft 30. The shaft 30 is nonround so that when it rotates, 
it carries the drum with it. The drum 25 must rotate at the same speed as 
the shaft 30. It will be observed that the drum 25 can move from one end 
to the other of the shaft. The fact that it is free to move between the 
ends is used in a manner to be described. The frame member 20 has bushings 
in it which are shaped to the shaft 30 and which are round on the exterior 
so that the elongate frame member 20 can rotate around the shaft 30, but 
it is not rotated. The follower is thus free to be opened or closed as 
desired. It is hand-lifted, as shown in FIG. 3, to raise the shift lever 
away from one of the traveling nuts. 
The drum 25 is slidably mounted on the shaft so it can be pushed from one 
end to the other. The shaft 25 is supported by an upstanding, vertical tab 
member 31 shown in FIG. 4, and a similar tab 32 is at the opposite end. 
The two tabs are perforated and receive suitable support bushings for the 
shaft. The shaft 30 additionally supports a hollow socket 33 for receiving 
a drive mechanism therein. The socket 33 at the end of the shaft 30 is 
adapted to receive and temporarily connect to the tip of a speedometer 
drive cable. Typically, a speedometer drive cable includes a flexible, 
shielded, outer, nonrotatable sheath member and an internal wire which is 
rotated. At the end, the wire connects with an enlargement, such as a 
threaded fitting or the like. In this instance, the rotatable wire is 
shaped into a suitable form for plugging into the socket so that the 
socket is rotated. This is accomplished with no slippage, thereby 
imparting rotation to the socket 33 and the appended shaft 30. This then 
rotates the mounting shaft 30 and the drum 25 which is carried on it. 
On viewing the apparatus in FIG. 4, the driven drum 25 has an outer 
periphery which is a friction surface which friction-engages a driven drum 
36. The drum 36 is rotated. It is rotated by frictional engagement. As 
will be observed from the top view of FIG. 4, the driven drum 36 is 
mounted on a shaft 40. The shaft 40 defines the centerline. As shown in 
FIG. 3, contact against the drum 36 is at the centerline only when the 
driving drum 25 is aligned with the shaft 40. It will be observed that the 
lead screw 14 is provided with a blank portion at 41. It is not possible 
to position a traveling nut at the space 41. If this were accomplished, 
this would result in positioning the drum 25 where it would contact the 
driven drum 36 precisely at its center, and no rotation would be imparted. 
As long as the point of contact is to the right or to the left of the 
shaft 40 as shown in FIG. 4, rotation is imparted. This is assured by the 
incorporation of a coil spring 42 which forces the drum 36 against the 
driving drum 25. The coil spring is captured against the upstanding wall 
44 which aligns the shaft 40. The upstanding wall 44 serves as a mounting 
plate for the equipment to be described. 
The shaft 40 is rotated via the driven drum 36. The shaft 40 is mounted on 
a similar end plate 46, better shown in FIG. 4 of the drawings. The plate 
46 is parallel to the plate 44, and the two plates together position and 
hold the shaft 40 at the required location. 
The shaft 40 includes an enlarged head 48. The head is received through an 
opening in a shift lever 50. The shift lever 50 has an elongate slot which 
passes around the shaft 40 to capture the shaft. The shift lever 50 
includes a tapered face portion 52 which contacts the enlargment 48 and 
forces the shaft to the left as viewed in FIG. 4. When this occurs, the 
drums 25 and 36 are disengaged from one another. Sliding movement of the 
slidable shift lever 50 thus axially moves the shaft 40, controlling 
frictional engagement. The shift lever 50 thus functions somewhat as a 
shift lever throwing the device into and out of gear. It disconnects the 
power source. 
The shaft 40 supports multiple decade gears. Only one is required at a 
minimum; preferably, four or five are incorporated. They operate in the 
following manner. The gear nearest the drum 36 rotates the most. The gear 
immediately adjacent to it rotates one-tenth as much. So to speak, the 
first gear counts in tenths of units, typically 0.10 miles per indication. 
This gear is identified by the numeral 55. The gear 56 counts units, a 
rate ten times greater than that of the gear 55. The gear 57 rotates 
one-tenth as fast and thereby counts tens of units, while the gear 58 
counts hundreds of units. The last gear 59 counts by thousands. 
The gears are driven so that rotation is transferred from the gear 55 to 
the gear 56. Such rotational transfer is achieved through an idler gear 
61. The idler gear 61 is better shown in FIG. 1 of the drawings. There, 
the idler gear 61 is located at the lefthand end of a shaft 63 on which is 
mounted several idler gears. The number of idlers is one less than the 
number of gears in the decade progression. The counter thus includes five 
decade gears. This necessitates the use of four idler gears between the 
decade gears. The idlers are preferably identical to one another because 
they count down by the same ratio, that is, ten revolutions at the input 
provide one revolution at the output. The several idler gears 61 are thus 
supported on a shaft 63 which, in turn, is supported at opposite ends by a 
generally U-shaped housing 64. The housing 64 provides a fixed mount for 
the shaft 63. The housing itself is rotatably mounted by its location on a 
pair of protruding shafts 65 received on tabs 66. The upstanding tabs 66 
are aligned with one another, there being one at each end of the U-shaped 
housing 64. The idler gears are forced against the decade gears by a coil 
spring 68, better shown in FIG. 2. The coil spring is mounted on the base 
plate 11. It forces upwardly against a tab 69, and the tab transfers the 
force of the spring to the U-shaped housing, thereby rotating the idler 
gears into operational contact. 
The idler gears are disconnected in the following manner. Through the 
application of simple thumb pressure, the U-shaped housing 64 is forced 
downwardly, all as viewed in FIG. 2 of the drawings, and the entire 
apparatus rotates around the mounting post 65. This pulls the idler gears 
away from engagement and lets the decade gears rotate without regard to 
the position of adjacent decade gears. They can all be adjusted 
individually to input any number required. When the spring 68 is released, 
it forces all the idler gears back into position. 
The idler gears achieve alignment because there is a notch 70 in each gear 
(see FIG. 1) which aligns with an enlarged tooth 71 on each idler gear. 
These are used for alignment purposes only. This prevents the idler gear 
from meshing incorrectly. Incorrect meshing is thus avoided, and, thereby, 
the large tooth 71 will fall into the large notch 70 immediately adjacent 
to the teeth on the decade gear. Each decade gear is provided with its 
own. It will be appreciated that there are N decade gears (where N is a 
whole number integer), and the number of idler gears is N-1. It is 
necessary to make only N-1 rotational transfers between the N decade 
gears. 
As shown in FIG. 2 of the drawings, the idlers are located on one side of 
the decade gears. A roller system at 74 is located on the opposite side. 
They bear against the decade gears from the opposite side. This is a means 
for keeping all the gears in alignment. The lateral forces applied by the 
rollers 74 are applied equally to all of the gears. As shown in FIG. 3 of 
the drawings, they can also be used to delineate a reference line so that 
the user can read the numbers as shown in FIG. 3. Alternately, an opaque, 
plastic shield can be placed over all the decade gears with notches left 
clear to show one number from each decade gear. For the description of the 
apparatus, it is best to describe it uncovered so that the parts and their 
interrelationship can be understood on viewing the drawings. 
In operation, the device functions in the following manner. The connector 
33 is attached to a speedometer drive cable of some form or fashion. It is 
presumed that the speedometer cable rotates at a speed which is 
proportionate to the speed of the vehicle in question. After this 
connection is made, the following adjustments are then implemented. First 
of all, it is determined whether or not the device is going to count in 
descending or ascending order. Once this determination is made, one of the 
two traveling blocks is selected. Reference is made to the lead screw 14 
and the traveling blocks which are mounted on it. The shift lever 20 is in 
position on the one which is required. It will be understood that one 
counts in the positive direction, and the other causes counting in the 
negative direction. 
The next step is to calibrate the device so that it is proportionate to 
some unit of measure, such as kilometers or miles. This is achieved by 
rotating the control knob 17. If the device is counting at too rapid a 
rate, it is rotated to bring the traveling nuts toward one another. This 
movement is achieved by hand rotation of the knurled knob 17 on the end of 
the lead screw 14. Such rotation is easily accomplished to reposition the 
traveling nuts closer to one another. 
Two or three tries are made on this. As soon as an indication is achieved 
by visual observation that the device is counting at the same rate as the 
unit of measure in question, the lead screw is then left in its position, 
and the next adjustment is then made. At this point, the device counts at 
the same rate, and it counts in the selected ascending or descending 
sequence required for its operation. Next, the device is zeroed. Zeroing 
may require readjustment of the decade wheels to zero value. It may 
require adjustment to some other value. Without regard to the particular 
value, the housing 64 is forced downwardly to disengage the idlers, and 
the gears are then hand rotated, one at a time, until they achieve a 
specified beginning value. The spring 68, once depressed, is then released 
so that the idlers are pushed back into meshing relationship. Once the 
idlers have been released, they restore the connective relationship 
between adjacent decade gears. Thus, the gear 56 then drives the gear 57, 
while the gear 57 drives the next gear 58 and so on. This sequence chains 
from the least significant to the most significant gear. 
At this juncture, the device is then functioning correctly. It will count 
up or down in units which are proportionate to a selected standard. As it 
counts, it can be used as a trip meter to indicate total mileage elapsed 
or mileage yet to be achieved, depending on how the device is used. 
In summary, the device incorporates the following three adjustments. It is 
adjustable to count in ascending or descending order as selected. It 
accommodates any scale and can be adjusted from one scale to another by 
altering the position of the traveling nuts on the lead screw. Thirdly, it 
can be set to any beginning value desired. 
The device can be used time after time by making the adjustments mentioned 
above. After the beginning adjustments are made, the device operates 
substantially without attention other than to observe the settings or 
readings obtained by the device. 
The foregoing is directed to the preferred embodiment, but the scope of the 
present invention is determined by the claims which follow.