Improvements in Speed-changing Mechanism.
Year: 1890

page_text: Date of Application, 23rd Sept., 1890-Accepted, 22nd Nuv., 1890
COMPLETE SPECIFICATION.
Improvements in Speed-changing Mechanism.
I, ALEXANDER JAMES ELI, of the firm of Hughes, Eli and Hughes, 76 Chancery
Lane, London, W.C. Patent Agents, do hereby declare the nature of this invention
(a communication to me from abroad by Lucius Erskine Whiton of New London,
State of Connecticutt United States of America, Manufacturer), and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
1
This invention has special relation to so-called "back gearing," used commonly in
engine lathes, drill presses, and like machines for increasing power, and seeks to
improve the construction of such mechanisms without adding materially to their
cost.
Heretofore, with few exceptions, the said gearing for the increase of power has
consisted of a shaft located in the rear of the cone-spindle and bearing gears that
may be thrown into and out of mesh with the fixed and loose gears on said
spindle.
One object of my present invention is to conceal the several elementary parts of
such gearing within a cone that receives the driving belt. My new construction
is also such that the change from quick to slow speed, or vice versa, may be effected
by a single movement.
I have shown in the accompanying drawings two forms of my device, the first being
illustrated in Figures 1 to 5 and the second form in Figures 6 to 9. In the first form
the change from fast to slow or vice versa, is effected quickly by one movement after
the machine stops, while in the second form the change may be effected without
stopping the apparatus, but in both constructions is embodied the feature of the
concealed gearing.
In Figures 1 to 5, Figure 1 is a front side elevation of a lathe head; part of the
cone and other operative parts being shown in section: Figure 2 is a cross section of
the same on line x-x, looking from the left hand end. Figure 3 is a similar view
Figure 4 is a
of the upper portion of Figure 2 showing the clutch mechanism.
partial end view showing the hand wheel for operating the clutch and gears.
Figure 5 is a detached perspective view of the movable section of said clutch.
In these drawings the figure of reference, 10, denotes a lathe-head having journalled
therein in the usual manner, a spindle 11, that carries a cone pulley 12 provided with
a central shell 14 forming a long bearing. This cone pulley is not secured fixedly to
said spindle, but under certain conditions hereinafter recited may be connected thereto
or disconnected therefrom. The larger end of said cone is open when cast and
within the smaller end are, preferably, a series of webs 13 connecting the shell 14
with the inner wall of the pulley which serve to strengthen and support the perimeter
of said cone.
The larger (open) end of the cone is closed when the complete devices
is ready for use by a plate 14, that is secured in place by screws 15, tapped into lugs 16,
cast on the inside of the cone. 17 and 18 indicate gearings of different diameters, the
larger (17) being connected directly to the spindle 11, and the smaller to a thimble 19,
secured in the lathe head and forming the bearing in which one end of the spindle
This thimble 19 is keyed within the lathe head so that it cannot by any accident
runs.

page_text: or undue strain become displaced, and it also projects within the end of the cone a
considerable distance, so that its attached gear 18, is concealed in the rear of the
plate 14 above referred to. It is intended that the smaller gear 18 of the pair above
referred to, should remain fixed, and it may obviously be attached to the journal
bearing by other equivalent means within the scope of my invention, the construction
shown being simply a convenient mode of securing it in position. Within the cone,
beyond the gear 17, is a disc 20, that is also connected to the spindle 11. This disc
is formed with a series of inwardly projecting lugs or teeth 21 providing a corre-
sponding series of intermediate spaces whose office 1 shall explain hereinafter. The
Figure 21' refers to a segment of a circular disc having projecting inwardly a
plate 22, whose outer face is recessed and cut under at its sides thus providing guide
ways in which may slide a piece 23, which I shall term a locking plate. The
segmental section 21¹ is secured to the cone by screws 24, as is clearly illustrated
in Figures 1 and 2 of the drawings and should be so. located relative to the notched
disc 20, that when the said locking plate 23 is moved outward, i.e. away from the
spindle, a projection 25 on its inner face will enter one of the spaces between the
described teeth or lugs 21, thus connecting the cone and the spindle and compelling
them to rotate together. 26' denotes a short shaft that is journalled eccentrically in
the plate 14, at one end, and in the extension 22 of the segmental section 21' at the
other end. Loosely fitted on the body of the said shaft are gears of different
sizes 26 and 27, either secured to or formed integral. The larger of these gears (26)
meshes with the fixed gear 18, while the companion gear (27) meshes with the spindle
gear 17.
The inner end of the shaft 26' has a small projecting stud 28 that is
eccentric to the bearings that support said shaft which extends into a transverse
slot 29 in the locking plate 23. The outer end of shaft 26¹ bears an operating lever
or hand wheel 30. By grasping said hand wheel and partially rotating it the gears
carried by shaft 26, may be thrown out of mesh with their respective companions
and, by the same movement the eccentric stud 28, working in slot 29, slides the
locking plate 23, in its ways, and brings the projection 25, into one of the spaces
between the teeth 21, thus locking together the cone and spindle and compelling
them to rotate as a single element. While for the sake of convenience I have shown
the locking plate 23 as operated by an eccentric stud 28, formed integral with and
extending from shaft 26, I do not wish to be confined to this construction, as a
separate shaft and eccentric stud for operating the locking plate would be equally
effective to connect the cone and disc and is properly within the scope of my
invention. To retain the shaft 26 in any desired position I prefer to square the shank
of the hand wheel 30, and provide a flat spring 31, whose free end may bear with
considerable force against the edges of said squared shank as will be best under-
stood by referring to Figures 1 and 4 of the drawings.
Assuming now that we have a complete lathe head, supplied with mechanism as
described, and that the band wheel 30 is partially rotated to throw gears 26-27 into
mesh with their companions, and also to throw the projection 25 out of engagement
with the disc 20, (as in Figure 1); and the cone being rotated motion will be
transmitted through gears 26-27 and 18-17, to the spindle 11, the speed of said
spindle relative to the speed of the cone being governed by the size of the several
gears of the train. To change from slow to fast speed it is only necessary to grasp
the hand wheel 30 and partially rotate it to throw out of gear the gears 26 and 27,
and throw into engagement the projection 25 with the disc 20, when motion will be
transmitted directly to the spindle 11. If it is desired to counterbalance the eccentric
shaft 26' and its connected parts another similar system may be provided at the
opposite side of the cone, or the cone casting may be weighted.
Referring to the second form of my invention Figure 6 shows substantially the same
view as Figure 1, the system of gearing only being different. Figures 7, 8 and 9
are detail views of the operating means for shifting the gear.
The novel feature of this form of my invention lies in the means for changing the
speed without stopping the pulley, the gearing being different from that illustrated

page_text: in Figures 1 to 5 and also the operating device, the pulley being the same in all other
particulars, and the mechanism being concealed in like manner.
In this construction to prevent end wise displacement of the pulley on the spindle
a collar 16, secured to the spindle 10, by a set screw 17, may be used; or the
central shell 14 of the pulley may be elongated sufficiently to abut against the hub of
the gear 24, hereinafter described.
The plate 18 closing the open end of the pulley provides a bearing near the
perimeter of the pulley for one end of a shaft 20 that carries two pinion gears 21-22.
The opposite end of the shaft 20 is journalled in a lug bearing 23 cast with, or
secured to, the cone pulley. These pinions 21-22 of different diameters, are
fastened firmly together or formed integral, and are journalled upon shaft 20, and
carried around by pulley 11, as said pulley rotates. 24 denotes a gear that is con-
nected or otherwise fixed on spindle 10, and meshes with pinion gear 21. 25 denotes
a similar gear of smaller diameter that meshes with the pinion gear 22 and is loosely
fitted on said spindle. Said gear 25 may be moved longitudinally but is always in
mesh with its companion gear 22, the latter being of unusual length as will be seen
by reference to the drawings.
The two opposite ends of the hub of gear 25 are formed as clutches as in Figure 7,
that on one end being adapted for interlocking with the correspondingly shaped hub
of gear 24, and that on the opposite end for interlocking with the end of a fixed
thimble 26, within the bearing or box 13. These clutches may be friction clutches
of any practical form or may be simply projecting lugs, as here illustrated, said lugs
being capable of interlocking with each other when the gear 25 is moved longitudinally,
on the spindle 10 as above described. The inner or fixed gear 24 is larger than the
loose gear 25 and the pinions 21-22 that complete the train are correspondingly
formed. When the loose gear 25 is forced inward and interlocked with gear 24, as in
Figure 6 it will be obvious that no correlative rotary motion can occur in the
described train of gears and that the cone-pulley 11 will become as a fast pulley on
spindle 10, and said pulley and spindle will rotate together, at the same speed, but
when the gear 25 is moved outward and its clutch is so interlocked with the thimble 26
that the rotation of said gear is prevented, then the rotation of the cone transmits
motion through the described train of gearing to spindle 10, which is thereby caused
to revolve in the same direction as the cone, but at a slower speed.
The outer end of the hub or gear 25 is formed with a circumferential groove 27.
Within the head block, immediately beneath the bearing 13, is a toothed rack 28,
whose inner end projects within the cone pulley and upward into the circumferential
groove 27. This rack is actuated by a pinion gear 29 on a shaft 30 journalled in
the head block, the exposed end of said shaft being provided with an operating
lever handle, or with a hand wheel 31 as herein shown."
In place of this toothed rack 28 it may sometimes be advantageous to substitute a
sliding plate 33, having a transverse slot 34, and in place of the pinion 29, and
eccentric 35, as shown in Figure 4,-this being simply an equivalent way of moving
gear 25, and other means may also be used.
The inner end or hub of hand wheel 31 may be squared and a flat spring 32 pro-
vided as in the case of the form first described.
When it is desired to move gear 25 to connect it with gear 24 the hand wheel 31
is grasped and partially rotated to the left hand (as arranged in Figure 1) this motion
being sufficient to slide rack 28 and its connected gear. When on the other hand
it is desired to move gear 25 outward, to slow down the spindle, the hand wheel is
rotated toward the right hand.
Gearing of the form specified, being concealed, does not expose the attendant or
the driving belt to the danger of becoming caught in the gears. It also permits the
use of a larger driving cone and greater initial velocity of the driving belt than
heretofore without interfering with the regular gradation of changes in the speed of
the spindle.
My device as a whole furnishes mechanism that is symmetrical in appearance, and
which is simple and strong in parts and positive in its action.

page_text: 1. In combination with a spindle, a cone pulley loosely fitted thereto, and a speed
changing mechanism located within said pulley, substantially as described.
2. In combination with a spindle, a cone pulley leosely fitted thereto-and-a-speed
changing mechanism-located within the pulley, a plate covering the open end of the
pulley, said plate-serving to support a part of the interior mechanism, substantially
as-described.
3. 1. In combination with a spindle suitably journalled and a pulley loosely fitted
thereon, a fixed gear arranged concentrically with said spindle, a larger gear fastened
to said spindle adjacent to said fixed gear, and gears journalled eccentrically upon
said pulley, and arranged to be thrown into and out of mesh with the said fixed
and spindle gears by the partial rotation of said eccentric journal, substantially as
described and shown in Figures 1 to 5.
4. 2. In combination with a spindle and a pulley loosely fitted thereon, a system of
gearing of the construction set forth for varying the speed of said spindle, and
mechanism for connecting and disconnecting the pulley and spindle, consisting of a
notched disc and a locking plate engaging said notched disc, substantially as described
and as shown in Figures 1 to 5.
3. In combination with a spindle and a pulley loosely fitted thereon, a system of
gearing as set forth for varying the speed of said spindle, a notched disc fastened to
the spindie, and a radially movable locking plate, actuated by an eccentric shaft
carried by the pulley and rotated by a convenient handle, said locking plate being
arranged to be thrown into or out of engagement with said notched disc by the same
movement which disengages or engages the system of gearing, all substantially as
described and shown in Figures 1 to 5.
6. 4. In combination with a spindle, a pulley loosely fitted thereon having connected
pinion gears 21-22 journalled near its perimeter, a gear fixed on said spindle in
mesh with the pinion 21, and having its hub formed with a clutch surface; a loose
gear on said spindle in mesh with the larger pinion 22, having both ends of its hub
formed with clutch surfaces; a fixed journal bearing for said spindle having a clutch
surface coincident with that on the outer end of said loose gear; and shifting
mechanism for moving said loose gear longitudinally on said spindle for engaging
and disengaging said clutch surfaces, as shown in Figures 6 to 9.
Dated this 23rd day of September, 1890.
HUGHES, ELI & HUGHES,
76, Chancery Lane, London, W.C., Agents for the Applicant.