IMPROVEMENTS IN DRIVING GEAR CALLED 11503 GRAD
Year: 1883

page_text: LETTERS PATENT to Fleeming Jenkin of 3 Great Stewart Street Edinburgh
Civil Engineer for an Invention of "IMPROVEMENTS IN DRIVING GEAR CALLED
11503 GRAD"
PROVISIONAL SPECIFICATION left by the said Fleeming Jenkin at the
Office of the Commissioners of Patents on the 6th October 1883.
FLEEMING JENKIN of 3 Great Stewart Street Edinburgh Civil Engineer
"IMPROVEMENTS IN DRIVING GEAR CALLED NEST GEAR
"
This invention relates to a new arrangement of what I have in general described
as nest gearing. By this invention I am able to tighten without any grinding by
means of what in my specification N° 1913 in the present year I have called the
second or wedge method; and I am also able to apply the expanding coned roller
described in my provisional Specification N° 4481 in the present year to tightening
the new nest.
I will first describe the form of my new invention adapted for concentric gear
in which the velocity ratio of two shafts in a line with each other is varied in any
convenient ratio.
Let the driving shaft carry the nest ring D revolving relatively slowly and let
the driven shaft A have the same axis as the driver. On the driven shaft I place a
double cone or pair of reverse cones each of these cones is supported by three
independent rollers B₁ B, B.-C₁ C, C, with their axes so inclined that the level
surfaces in contact roll together. One set of these intermediate rollers as B, B, B,
rolls inside an internal cone inclined in one direction and the other set as C₁ C₂ C₂
rolls on a second internal cone inclined in the other direction. These two internal
reverse cones are conveniently joined so as to form the single nest ring D. Then
by forcing together the two reverse cones on A or forcing them apart according to
the arrangement of the cones the whole nest is tightened up so that no end
pressure comes on the shafts of A or D and all the surfaces may roll accurately on
each other. To effect this the axes of the set of cones on one side namely one
cone on A, the cone on the same side of D and the intermediate rollers on the same
side as B, B, B, should all intersect in one point. The pins or shafts of the
intermediate rollers may end in bevil surfaces which roll on each other or the faces

page_text: of these wheels may roll on each other. The expanding roller described in my
provisional specification N° 4481 can be employed on A.
Or again the tightening may be effected by pinching two parts of the nest ring
together or forcing them apart.
Or the tightening might be effected by drawing together or forcing apart the
two sets of intermediate rollers.
The two sides of the nest ring are commonly and conveniently made symmetrical
but this is not necessarily done-there may be a small and a large side. More-
over this new arrangement is applicable to what I have termed the second variety
of concentric nest gearing in my prior specification N° 1913 in which the speed is 1
altered in a duplicate ratio.
Moreover the tightening might be effected by what I have called the eccentric
method in the same specification instead of by cones pinched together or forced
apart or it might be otherwise effected.
Moreover the outer nest ring D might be fixed and the driven or driving shaft
may be affixed to the frame carrying the "six intermediate rollers--or three of
them. In all cases only one shaft should have an absolutely determinate position,
the other axes being so far free that the pressure between the rolling surfaces
causes no friction.
The above describes a perfect form of nest in which by the reduplication of
parts the tightening pressure causes no rubbing. friction on the driving or driven
shafts. A less perfect but still useful form is obtained when half of the above
nest is omitted and the tightening effected by forcing one cone as that on A by an
endways pressure between the inclined cones as B, B, B.-the tightening force might
be applied to the intermediate rollers or to the nest ring. Any ring may be the
driver and any other the follower and any part may be the fixed part so long as
the relative motions remain the same.
Thus this gear may be used as oblique gearing one of the inclined rollers being
attached to the driving or driven shaft. The inner bevelled roller A may be made
of large size and hollow so that a spindle may pass through it and the two parts of
this ring in the complete form may be divided and hollow:--
Again the intermediate rollers B, B, B, and C, C, C, may lie in planes parallel
to the shafts of A and D and at right angles to the plane in which A and D
revolve. Two out of the three rollers on each side may then be omitted without
causing end pressure on A or D. This right angle arrangement makes the velocity
ratio of A and D equal but opposite in direction. It may be used as a friction
clutch and reversing clutch-for if the frame holding B, C, is held at rest A. and D
revolve with equal opposite velocities-if that frame is left free A and D are
disconnected. If the frame is connected directly or by friction or otherwise with
either A or D the two shafts revolve with equal velocity in the same direction.
The connection between the frame and A or D can be effected by preventing one
of the intermediate rollers from revolving. Considerable advantage in all these
arrangements results from the large bearing surface which can be obtained without
grinding and consequently with compactness and the automatic compensation for
wear,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Fleeming Jenkin in the Patent Office on the 5th April 1884.
FLEEMING JENKIN of 3 Great Stewart Street Edinburgh Civil Engineer
" IMPROVEMENTS IN DRIVING GEAR CALLED NEST GEAR
"
This invention relates to a new arrangement of what in the specification of a
former Patent granted to me N° 1913 I have in general described as nest
gearing.
My new arrangement is adapted for concentric gear in which the velocity ratio
of two shafts in a line with each other is varied in any convenient ratio-it is as
follows:-
The driving shaft or the shaft revolving relatively slowly carries the nest rings.
The driven or rapidly running shaft is aligned with the driver. On the latter
shaft I place a double cone or pair of reverse cones-each of these cones is
supported by three independent rollers with their axes so inclined that the level
surfaces in contact roll together. One set of these intermediate rollers rolls inside
an internal cone inclined in one direction and the other set rolls on a second
internal cone inclined in the other direction. These two internal reverse cones
are conveniently joined so as to form the single nest ring. Then by forcing
together the two reverse cones on the rapidly running shaft or forcing them apart
according to the arrangement of the cones the whole nest is tightened up so that
no end pressure comes on the driving or driven shafts and all the surfaces roll
accurately on each other if the axes of the set of cones and rollers on one side all
intersect in one point. The pins or shafts of the intermediate rollers may end in
bevil surfaces which roll on each other or the faces of these wheels may roll on
each other.
The above describes a perfect form of nest in which by the reduplication of
parts the tightening pressure causes no rubbing friction on the driving or driven
shafts. A less perfect but still useful form obtained when half of the above nest
is omitted and the tightening effected by forcing one cone endways.
In order that my invention may be most fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 1a. show a sectional side elevation and a front elevation of one
complete form of my new gear.
A is an expanding roller by which the pressure is applied between the faces of
all the rollers. A is made in two halves one of which is fast on the shaft a and
the other slides on a feather on the same shaft. The spring S which forces these
apart is made of the strength required to produce the necessary frictional adhesion
at the faces of the rollers.
The two halves of A are coned opposite ways and bear up against six intermediate
rollers B which run in bearings f secured to the frame D which is secured to the
base plate or foundation by any suitable means a projection for the purpose is
shown at the spindles 6 of the rollers B have so much play radially as secures
that the pressure due to A shall be taken by the face between B and C and not
by the bearings f. The outer nest ring C has cones in opposite directions as
shown the cones of B. C. and A all meet in two points in the axis of A so as to
run true together.-C is keyed to the shaft c and overhung-the pulley A. is also
overhung but finds its support ultimately in the slow running bearing of C. It
should be observed that the end pressure on the spindles 6 of the rollers B is taken

page_text: {"
if they slip inwards by their butting one against the other. The surfaces of the
spindles coned at the ends as shown run true together.
Figure 2 and Figure 2a. show a second form of the complete gear. The action
will be obvious from the preceding description-the principal change is in the
.tightening roller A the two halves of which are drawn together instead of being
forced apart-this reverses the coning of the wheels but the principles involved
are unchanged.
Figure 2.6. shows one form of end bearing for the spindles f by which the end
pressure not taken by the spindles where they abut may be received―I make no
claim in respect of this bearing..
Figure 3 and Figure 3.a. show the less complete form of this gear-instead of
six intermediate rollers B there are only three-the tightening of the gear is in
this example effected by forcing in the frame D by means of a screw Sa spring
'might be employed for the same purpose. It is obvious that in this form the
tightening might be effected by pushing in the shaft of A or by pushing the shaft
of C in the opposite direction-but the form shown constitutes a good friction
clutch. I call this half or incomplete gear cup gear.
The bearings of the intermediate rollers B are shown made with sliding blocks f
instead of oval bearings, and the brasses g are pivotted in these sliding blocks so
as to let the cones B take up exactly the angle required by the faces of A and D
with no possible couple on the spindles b.
Figure 4 shows a form of cup gear in which the tightening is effected by the
weight of the revolving part M which is borne by the shaft A. The frame D is
fixed and the shaft A is guided by the frame but the guides are not shown. A is
ultimately supported by the bearings of C which are the slow running bearings.
This arrangement is very suitable for getting up a high speed with the least
possible friction.
Having thus described the nature of my said invention and the manner of
performing the same I would have it understood that I claim :-
First My arrangement of nest driving gear consisting of a pair of reverse cones
and two sets of conical rollers contained within a nest ring; the conical rollers of
each set rolling upon one of the cones and along a conical surface within the nest
ring substantially as described.
Second My half nest gear with a single cone, one set of conical rollers around
it and a single cone nest ring substantially as described.
Third The complete gear as shown in the example drawn in Figures 1 and 1.a.
Fourth-The complete gear as shown in the example drawn in Figures 2 and 2.a.
Fifth The half gear as shown in the example drawn in Figures 3 and 3.a.
where the tightening is effected by moving the frame D relatively to the
foundation or base plate.
⚫ Sixth-The half gear as shown in Figure 4 where the tightening is effected by
the motion of A. or C relatively to the foundation.
In witness whereof I the said Fleeming Jenkin have hereunto set my hand and
seal this fourth day of April in the year of our Lord One thousand eight hundred
and eighty four.