Improvements in Friction Gearing for the Interchange of Rotary and Rectilinear Motion.
Year: 1889

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COMPLETE SPECIFICATION.
Improvements in Friction Gearing for the Interchange of Rotary
and Rectilinear Motion.
I, WHITCOMB LEONARD JUDSON, Mechanic, of the City of Minneapolis, County of
Hennepin, State of Minnesota, United States of America, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
My invention is especially designed for use in connection with a street-railway
system, but is capable of universal application wherever it is desired to turn a rotary
into rectilinear motion.
It consists of the construction hereinafter fully described, and particularly pointed
out in the claims.
In the drawings, like letters referring to like parts throughout, figure 1 is a side
elevation of my preferred construction; figure 2 a cross section or end view of the
same; figure 3 a plan of the driving-drum and friction-wheels partly detached from
their supporting-frame; figure 4 is a side elevation of a modified construction;
figure 5, an end view or cross-section of the construction shown in figure 4; figure 6,
a plan of the driving-drums and friction-wheel detached from their supporting-frames;
and figure 7 is a plan of a part of the supporting-frame in which the friction-wheel is
mounted.
In the construction shown in figures 1, 2 and 3 I use a single driving drum or
shaft and a pair of traveling friction-wheels engaging therewith at an angle to its
axis.
In the construction shown in figures 4 to 7, inclusive, I use a pair of parallel driving-
drums, continuously revolving in the same direction, and a single traveling friction-
wheel engaging with both drums at an angle to their axes.
If the friction wheel or wheels are placed at a right angle to the driving drum or
drums, they will not travel lengthwise thereof. If they take any other than a position
at right angles to the driving-drums and the parallelism of their axes be preserved,
they will travel in one direction or the other along the driving drum or drums.
Referring now to the various figures, I have shown the motion as applied to
reciprocate a small car or carriage on a definite track-such, for example; as might
be used in a planing-machine, a saw-mill, or other machines wherein a reciprocating
motion might be desired.
A is a driving-drum in fixed supports B. As shown, these fixed supports are
cross-bars secured to upright posts Con the opposite sides of the shaft.
To
Dare girders mounted on the tops of the vertical posts, and E are rails bolted to
the girders D. Fis a small car or carriage whose wheels rest on the rails E.
this car is secured a spider or yoke G, provided at its outer extremities with circular
rims G G These rims are provided on their outer surfaces with inwardly-project-
ing flanges g.
H are revoluble heads mounted in the rims G¹ G₁ and provided with journal-bear-
ings h and plates h¹ overlapping the flanges g.
K are traveling friction-wheels mounted in the revoluble heads H.

page_text: L is a rock-shaft on the car F, and is provided with cranks L1 and L¹¹, opposite to
each other. From these cranks extend connections and 1', respectively, to the
revoluble heads H...
M is a hand-lever on the rock-shaft L. M' is a notched segment adjacent thereto.
M is a pawl on the lever M, for engaging with the notched segment M'. By means
of the lever M and its connections the revoluble heads H may be moved in opposite
directions in the supporting-rims G¹ and G¹¹, thus varying the angle of the friction-
wheels K to the driving-shaft A, while preserving the parallelism of the axes and the
peripheries of said wheels.
As shown, the yoke or spider G is curved spring-bar. For the purpose of obtain-
ing a variable traction suitable to the load, a right and left screw, N, passes through
corresponding nuts on the outer ends of the yoke G and is provided with a
hand-lever N, extending within reach of the operator of the car.
N" is a notched segment adjacent to the lever N.
N is a pawl on the lever N₁ for engaging with the segment N.
Referring now to the modification shown in figures 4, 5, 6 and 7, P P¹ are a pair
of parallel driving-drums similar to the driving-drum A, arranged adjacent to each
other and continuously revolving in the same direction. Q is a swiveled yoke
mounted on the car F, provided with the journal-bearing q. R is a single traveling
friction-wheel mounted in the bearings q. S is a segment-plate provided with a curved
groove, S¹, secured to a part of the car adjacent to the swiveled yoke Q. T is a cross-
head or movable block mounted in the groove S¹. U is a hand-lever fulcrumed in the
block T intermediate its extremities, and pivotally connected at its inner end to the
yoke Q. V is a coiled spring encircling the vertical shaft of the yoke intermediate
the car-frame, or a boss, W on the same, and the bifurcated arms of the yoke.
It is evident that by the lever U and its connections the yoke may be swung through
the arc of a circle and the friction-wheel be made to take any desired angle to the
parallel driving drums; hence the car may be made to stand still or to travel in
either direction lengthwise of the driving-drums at a variable speed.
The advantage of using one device of one kind opposed to two of the other is that
thereby a wedging or crowding action is secured, giving far better frictional contact
and a resultant of forces substantially in a straight line without other limiting-guides.
The driving drums may be driven in any suitable way from a source of power.
In the drawings the drum or drums have been shown as the propeller, and the
friction wheel or wheels as the traveler; but it will be readily understood that the
reverse arrangement will work. A rectilinear motion of the friction-wheels will
impart a rotary motion to the drums; or, if the friction-wheels be mounted in fixed
supports and made to rotate and the drum or drums in movable supports, the former
being at an angle to the axis of the latter, the drums will be made to travel in a right
line. In other words, the wheels and the drums are interchangeably propellers or
travelers. It should also be noted that the power is convertible into speed or the
speed into power, at will. If the propeller be driven with uniform power and speed,
it will take effect on the traveler more in speed or more in power, according to the
angle of the wheel or wheels to the drum or drums, which angle is variable at will.
In other words, the construction is practically that of a screw and nuts of a pitch
variable at will, frictional contact taking the place of the positive thread. The drums
are threadless screws, and the wheels are nuts following imaginary lines thereon by
frictional contact, the pitch of which and the direction of which (from right to left)
are variable at will.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of a cylindrical drum and friction-wheel devices capable of
angular engagement with each other, there being one device of one kind and two of
the other, and the angles of engagement variable at will, whereby the rotation of the
device or devices of one kind gives a rectilinear movement. the speed of which is

page_text: proportionate to the angle of engagement to such of the other as are engaged thereby,
substantially as described.
2. The combination of cylindrical-drum and friction-wheel devices capable of
angular engagement with each other, there being one device of one kind and two
of the other, such as are employed of one kind being mounted in fixed, and such as
are employed of the other in movable supports, substantially as described.
3. The combination, with a cylindrical driving-drum, of two friction-wheels capable
of angular engagement therewith, the said wheels being mounted in movable bear-
ings, whereby their angles of engagement with said drum may be varied, substantially
as described.
4. The combination, with a cylindrical driving-drum mounted in fixed supports,
of two friction-wheels capable of angular engagement therewith on opposite sides,
said wheels being mounted in a movable support and in movable bearings in said
support, substantially as described.
Dated this 15th day of May 1880
29th May 1889.
WHITCOMB LEONARD JUDSON.
Abel & Imray,
28, Southampton Buildings, London, W.C., Agents for the Applicant.