Year: 1855

page_text: stantly required. In such machinery the driving shaft which gives motion to
the screwing spindles carries a differential friction wheel, consisting of a large
dise with-an-internal frictional surface rim, and a plain edge frictional pulley,
concentric with the disc's centre. This disc and its concentric pulley may
either be in one piece or in two separate pieces. This frictional apparatus
forms the means of communication between the continuously revolving driving
shaft and the actual movements of the tool. For example, the cone speed
pulley receiving motion by a band from the main driving shaft of the work-
shop may be the continuous revolver; this cone pulley shaft having upon it a
frictional pulley, somewhat less in diameter than the space included between
the external periphery by the frictional pulley of the differential wheel and the
internal frictional surface of the disc's rim. Hence, although continually
revolving with the cone pulley shaft, if kept in the clear intermediate position
between these two frictional surfaces, this driving frictional pulley will not
communicate any movement in either direction to the differential wheel. But
when the pulley is shifted to one side or the other, it comes in frictional con-
tact either with the disc rim or the pulley connected therewith, and of course
communicates motion accordingly. To give the necessary shift of the driving
pulleys, a rocking or oscillating holding frame is employed. This frame carries
the bearings for the cone pulley shaft, and it swings itself upon a couple of
centres placed in line with each other, but at a slight distance out of the line
of the cone centres. Each overhanging journal end ofthe swinging frame has
attached to it a vertical weighted tuinbling lever, with a connecting handle
passing to a part of the tool convenient to the operator's hand. Hence, by
pushing this connecting rod or handle from its central position to one side or
the other, the frictional driving pulley is carried over to one side or other,
owing to the lever action, arising from the discrepancy between the centres
of the cone pulley and the centres of its swinging frame. This contrivance
gives the operator peculiar facility in reversing as well as in suspending
the operation-of-his-machine-or-tool, the relative-rates of-revolution of the
shafts actuated through the agency of the differential wheel due to the
position of the intermediate frictional driving pulley being as the relative
diameters of the frictional rim disc and the concentric pulley thereof. Thus,
this difference in diameter answers well for giving the rapid return revolution
which is required for economising time in most cases of reversing. The
action of the parts is such, that from the angle involved, the tensional effect
of the driving band answers for keeping the frictional surfaces in effective
driving contact, whichever surface of the differential wheel may be in use.
Instead of combining the frictional rim disc and its concentric pulley in one

page_text: piece, these two details may be at any distance asunder on the same shaft.
Of course this latter modification involves the use of two separate driving
frictional pulleys. The eccentric system of shifting for reversing the driving
contact surfaces is applicable under various modifications of the other details.
For example, the driven shaft which requires to be reversed may carry two
plain frictional-faced discs, whilst the continually revolving driver at right
angles therewith carries two frictional-edge pulleys. This latter shaft is
capable of lateral shifting by the agency of a handle connected with an
eccentric lever movement on the principle already described, so that a slight
lateral shift brings either pair of frictional surfaces in driving contact as may
be desired. If the velocity is to remain unchanged, then a single intermediate
frictional driving pulley only-is required. The same effect is producible when
the frictional surfaces bevilled or coned, or when toothed wheel work is
employed instead of mere frictional surfaces. A similar reversing effect can
be made to operate upon segmental levers and other similar details by dis-
posing a continuously revolving pulley or wheel between contiguous concave
and convex acting surfaces on such lever. Toothed wheel worked beused
in all these differential wheel or reversing arrangements insteadoffrictiononly;
but it is preferred to employ plain ground cast-iron surfaces, or the acting
surfaces may be annularly corrugated or grooved, to increase the frictional
hold. Such reversing apparatus. is available in the arrangement of screwing
machines, planing, sawing, and screw nail-making machines, screw cutting
lathes, travelling saw benches,wood-cutting machines withtraversingbenches,
screw punching and pressing machines, steam winches, cranes, and hoists,
handling gear for steam engines valves, forging and hammering machines, as
well as in a variety of other movements and machines wherein a reversing
power is necessary.
may

page_text: thousand eight hundred and fifty-five, in the eighteenth year of Her reign
did, for Herself, Her heirs and successors, give and grant unto me, the said
James Robertson, Her special license that I, the said James Robertson,
my executors, administrators, and assigns, or such others as I, the said
James Robertson, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
TRANSMITTING MOTIVE POWER IN CERTAIN CIRCUMSTANCES WHERE REVERSING
ACTIONS ARE NECESSARY," upon the condition (amongst others) that I, the said
James Robertson, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Robertson, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates to various mechanical arrangements for the
purpose of transmitting motion in combination with the power of quickly and
easily reversing the direction of such motion. Such mechanical arrangements
are of obvious value for a great variety of uses, and especially so in the con-
struction of tools and constructive machinery. Under one form the Invention
is well suited for use in screwing machinery where a reversing rotatory
action is constantly required. In such machinery the driving shaft which
gives motion to the screwing spindles carries a differential friction wheel,
consisting of a large disc with an internal frictional surface rim, and a plain
edge frictional pulley concentric with the disc's centre. This disc and its
concentric pulley may either be in one piece or in two separate pieces. This
frictional apparatus forms the means of communication between the con-
tinuously revolving driving shafts and the actual movement of the tool.
For example, the cone speed pulley receiving motion by a band from the main
driving shaft of the workshop may be the continuous revolver, this cone pulley
shaft having upon it a frictional pulley, somewhat less in diameter than the
space included between the external periphery of the frictional pulley of
the differential wheel and the internal frictional surface of the disc's rim.

page_text: Hence, although continually revolving with the cone pulley shaft, if kept in
the clear intermediate position between these two frictional surfaces, this
driving frictional pulley will not communicate any movement in either direc-
tion to the differential wheel. But when the pulley is shifted to one side
or the other, it comes in frictional contact either with the disc rim or the
pulley connected therewith, and of course communicates motion accordingly.
To give the necessary shift of the driving pulley, a rocking or oscillating
holding frame is employed. This frame carries the bearings for the cone.
pulley shaft, and it swings itself upcu a couple of centres placed in line
with each other, but at a slight distance out of the line of the cone centres.
Each overhanging journal end of the swinging frame has attached to it a
vertical weighted tumbling lever, with a connecting handle passing to a part
of the tool convenient to the operator's hand. Hence, by pushing this con-
necting rod or handle from its central position to one side or the other, the
frictional driving pulley is carried over to one side or other, owing to the lever
action, arising from the discrepancy between the centres of the cone pulley and
the centres of its swinging frame. This contrivance gives the operator peculiar
facility in reversing as well as in suspending the operation of his machine or
tool, the relative rates of revolution of the shafts actuated through the agency
of the differential wheel due to the position of the intermediate frictional
driving pulley being as the relative diameters of the frictional rim disc and the
concentric pulley thereof. Thus, this difference in diameter answers well for
giving the rapid return revolution which is required for economising time in
most cases of reversing. The action of the parts is such, that from the angle
involved the tensional effect of the driving band answers for keeping the
frictional surfaces in effective driving contact, whichever surface of the dif-
ferential wheel may be in use. Instead of combining the frictional rim discand
its concentric pulley in one piece, these two details may be at any distance
asunder on the same shaft. Of course this latter modification involves the
useof two separate driving frictional pulleys. The eccentric system of shifting
for reversing the driving contact surfaces.is applicable under various modifi-
cations of the other details. For example, the driven shaft which requires to
be reversed may carry two plain frictional-faced discs, whilst the continually
revolving driver at right angles therewith carries two frictional-edge pulleys.
This latter shaft is capable of lateral shifting by the agency of a handle con-
nected with an eccentric lever movement on the principle already described,
so that a slight lateral shift brings either pair of frictional surfaces in driving
contact-as-may-be-desired. If the velocity-is-to-remain-unchanged, then-a-
single intermediate frictional driving pulley only is required. The same effect.

page_text: is producible when the frictional surfaces are bevilled or coned, or when toothed
wheel work is employed instead of mere frictional surfaces. A similar reversing
effect can be made to operate upon segmental levers and other similar details
by disposing a continuously revolving pulley or wheel between contiguous
concave and convex acting surfaces on such lever. Toothed wheel work may
be used in all these differential wheel or reversing arrangements instead of
friction only; but it is preferred to employ plain ground cast-iron surfaces;
or the acting surfaces may be annularly corrugated or grooved to increase the
frictional hold. Such reversing apparatus is available in the arrangement of
screwing machines, planing, sawing, and screw nail-making machines, screw
cutting lathes, travelling saw benches, wood-cutting machines with traversing
benches, screw punching and pressing machines, steam winches, cranes, and
hoists, handling gearfor steam engine valves, forging and hammering machines,
as well as in a variety of other movements and machines wherein a reversing
power is necessary.
And in order that my said Invention may be properly understood, I shall now
proceed to describe the several explanatory Figures on the Sheet of Drawings
hereunto attached, such Figures representing a sufficient variety of modes of
working out my said Invention in practice to enable the practical engineer to
apply it wherever it may be found suitable.
Figure 1 on the Sheet of Drawings is a side elevation, Figure 2 is an end
elevation, and Figure 3 is a plan, of a screwing machine furnished with my
improved mechanical arrangement for reversing the notion imparted to its
rotating details.
The machine is of the ordinary kind as regards its general features, being
provided with two horizontal tubular shafts A,B, for screwing different sizes of
bolts or nuts. The shaft A has fixed upon it a spur wheel C, which is in gear
with an intermediate spur wheel in gear with a pinion D on the shaft B, the
shaft A being thus driven at a slower speed than the shaft B. This shaft B is
driven by means of the rim or internally-faced wheel E, which is represented
in face view in Figure 4, and in section in Figure 5, on the Sheet of Drawings
hereunto attached. The wheel E is formed with two rims F and G, the outer
rim F being grooved internally and the inner rim G externally, the grooves
running circumferentially round the wheel in both cases. A pulley H on the
driving shaft I projects into the space between the two rims F and G of the
wheel E, and is grooved in a similar manner to these rims to increase its
frictional hold when it is in contact with either of them. The shaft I carries a
set of cone pulleys J, which receive a driving belt K from the overhead
driving shaft of the workshop. The shaft I is carried in bearings L upon a

page_text: swinging frame piece M, which is itself mounted in working bearings N upon
the framing O of the machine. The centres N, or the axis upon which the
frame piece M swings, is slightly eccentric to the axis of the shaft I; whence it
follows that by turning the frame piece M in its bearings, the shaft I will be
made to change its position. The component parts of the apparatus are so
proportioned to each other that a very slight movement of the frame M will
shift the shaft I, so as to bring the pulley H into contact with either of the
rims or grooved working surfaces F, G, of the wheel E. If the pulley H is
brought into contact with the outer rim F, it will impart a slow powerful motion
to the wheel E; whilst if it is brought into contact with the inner rim G, the
motion imparted will be comparatively quicker and less powerful, and it will
moreover be in the opposite direction to that of the motion previously imparted
through the outer rim F. A pair of rods P are fixed to the swinging frame, M
to carry weights Q, which are so placed as to fall to one side or to the other
accordingly as the pulley H is in contact with the rim For the rim G, and in
either case to aid by its gravity in keeping the pulley in contact with the rim.
Long handles R, stretching over the machine so as to be in convenient
positions for the workman, are attached to the rods P, to enable him to shift
the frame piece M as he requires to reverse the screwing motion.
In Figure 6 on the Sheet of Drawings is represented, in plan, an arrange-
ment by means of which an equal or nearly equal speed is imparted to the
driven shaft in both directions of its motion. The driven shaft A has fast
upon it a wheel B. formed with a single frictional rim or working surface C,
which is acted upon internally by a pulley D on the driving shaft E.
The shaft A has likewise fixed upon it a pulley or frictional wheel F,
arranged to be driven externally by a friction pulley G upon the shäft E,
continuously revolving in one direction, imparts motion in one direction or
the reverse to the shaft A accordingly as the pulley D is in contact with
the rim C of the wheel B, or as the driving pulley G is in contact with the
driven pulley F. The shaft. E is carried in bearings in the swinging frame
piece H, which is fornied with journals I to turn in bearings in the stationary
framing, the journals I being eccentric to the shaft E, so that by turning
the frame H, as inay be effected by means of the lever J, the shaft E may be so
shifted as either to bring the pulley D into contact with the wheel B, or the
pulley G into contact with the wheel F; or again, so as to keep both driving
pulleys D and G out of contact with either of the wheels B or Fin which last
case no motion will be imparted to the shaft A. As the proportion of the
pulley
D-to-the-wheel-B-is-about-the-same-as-that-of-the-pulley-G-to-the-
pulley F, the shaft A will be driven with about equal speed in both direc-

page_text: tions; but it will be obvious that the comparative proportions between the
pairs of wheels may be varied, so as to give any difference of speed that may
be required.
In Figure 7, on the Sheet of Drawings hereunto attached, is shewn, in plan,
amodification ofdriving mechanism with reversing arrangements, in which the
driven shaft A is at right angles to the driving shaft B. Two conical pulleys
C and D are fixed upon the shaft A, and the shaft B carries a third conical
pulley E, the surfaces of all three pulleys being grooved or stepped to produce
an increased holding friction when in working contact with each other. The
pulley E is shown as lying midway between the pulleys C and D, and not in
contact with either of them, in which position it imparts no motion to the
shaft A. The pulley E, however, drives the shaft A in one direction or the
other accordingly as it is brought into contact with either of the pulleys Cor D.
The shaft B is passed eccentrically through a tubular bush or short shaft F,
having a driving pulley G fixed upon its opposite projecting end. The bush F
is carried in stationary bearings H, and it has a lever I keyed upon it.
Figure 8 on the Sheet of Drawings hereunto attached shews the eccentric
position of the shaft B in the bush F, and the lever I fast upon the latter: By
turning the bush F in its bearings by means of the lever I, it shifts the position
of the shaft B on account of the eccentricity of this last, so as to put the
pulley E into contact with one of the pulleys C, D, thereby causing the rotatory
motion of the shaft B to be communicated to the shaft A in whichever
direction it may be wanted.
Figure 9, on the Sheet of Drawings hereunto attached, is a side elevation,
and Figure 10 is a plan, of a frictional action forge hammer shewing the.
application of my Invention where only a partial rotatory mction is required.
Figures 11 and 12 are explanatory views of detached parts of the hammer.
The framing of this apparatus consists of a sole plate A, upon which the
anvil B is cast or fixed; and upon which two cast-iron side standards Care
bolted down. In these standards are eyes for the spindles D, upon which the
hammer lever E turns or swings. The hammer lever E is fixed in a swinging
block F, formed below with a segmental aperture G, as seen in Figure.11,
the inner and outer surfaces of which are described with radii from the centre
D. Though the aperture G is passed a shaft H, which carries a fly wheel I,
a pulley J to receive a driving belt from an over-head shaft and a frictional
driving pulley K. The pulley K is grooved circumferentially, as are also the
circumferential surfaces of the aperture G, to givethepulley increased frictional
holding power upon them. The shaft H is passed eccentrically through
bushes Lconnected together by a bow piece M, and the bushes L are capable

page_text: of turning in bearings in the side standards C, having a double-armed lever N
fixed upon one of them for turning them by. The shaft H being in continuous
motion, a slight movement of the lever N causes the pulley K to enter into
contact with the internal surface of the outer rim of the segmental aperture G
in the swinging block F of the hammer, and, by turning this block to lift
the hammer O. When the hammer is raised sufficiently, the lever N is
shifted so as to bring the pulley K into contact with the inner side of the
segmental aperture G, which has the effect of not only allowing the hammer
to fall, but also of aiding its descent, by imparting a partial rotatory motion to
the swinging block F in the opposite direction to that of the lifting motion,
the lesser radius of the inner side of the aperture G-causing a greater speed
to be imparted to the block upon the descent than upon the ascent of the
hammer; or by shifting the palley into a position midway between the two
sides of the segmental aperture G, the hammer may be allowed to fall by its
own gravity. A block of wood Pis passed across between the standards C
for a catch Q on the swinging block F to strike against, to prevent the hammer,
being turned up too far.
In Figures 13 and 14, on the Sheet of Drawings hereunto attached, is shown
an arrangement, very similar to that last herein-before described, for giving a
vibratory or partial rotatory motion to a lever, such, for example,as theworking
lever of a punching or metal shearing machine. Figure 13 is a side elevation
of the lever as detached, and Figure 14 is a plan or edge view thereof. The
lever A which turns upon the centres B is formed with an arm C, in which is
a segmental aperture D, having inner and outer frictional surfaces described
with radii from the centre B. In this aperture D works a continuously
revolving pulley E, formed with a frictional surface to act upon the segmental
arm C. The shaft F ofthe pulley E is passed eccentrically through bushes.G,
by turning which in their stationary bearings, as in examples herein before
described, the pulley is brought into contact with either the inner or outer
frictional surface of the aperture D, and motion is given to the lever Ain one
direction or the other accordingly, the difference in the length of radius of
the two sides of the aperture rendering the motion imparted quicker in one
direction than in the other. In the various modifications of driving and
reversingmechanism comprehended under the presentInvention,variouskinds
of frictional surfaces may be used fortransmitting the motion. Such surfaces
may either be smooth or plain, and composed of any suitable material; or they
may be grooved or corrugated, or otherwise modified, to increasetheir frictional
holding action-have herein-before-described the reversing action as being
obtained by shifting the driving shaft; it will, however, be obvious to the

page_text: practical engineer, that the same result may be attained by shifting the driven
shaft where it is convenient to do this. One very convenient application of
this inverse arrangement is to be found in the construction of a lathe for
chasing or cutting screw bolts.
Figures 15, 16, and 17, on the Sheet of Drawings hereunto attached,
represent a lathe of this kind as constructed with my improved driving gear;
Figure 15 being a side elevation with a portion of the framing broken away;
Figure 16, a plan, partly in horizontal section; and Figure 17, an end eleva-
tion, partly in section. The headstocks A, B, C, of the lathe are all formed
upon a single casting D, which is also made with long journals E. The head-
stock piece rests by means of these journals in the bearings F at each end
of the lathe bed G, being capable of rocking in, these bearings, and also of
shifting longitudinally within certain limits. The spindle H of the lathe and
the opposite centre I are set in the headstocks A, B, C, in a position slightly
eccentric to the journals E of the rocking headstock piece, and motion is
communicated to the spindle H by means of a drum J fixed upon it. This
drum is made with a long outer rim, formed with an internal frictional surface,
and with a cylindrical boss of corresponding length, made with an external
frictional surface. The drum is driven by means of a pulley K, which lies
between the rim and the boss; this pulley being fixed on a spindle L,which
carries the usual driving cone pulley M for a belt from an over-head shaft.
A lever handle N is fixed upon the headstock C in a convenient position for
the workman, who by shifting the headstock piece on its journals causes the
drum J to bring its rim or its boss into contact with the friction pulley K, so
as to be driven in either direction accordingly. In this machine the tool O
for chasing the screw bolt P is a fixture. As the movement of the rocking
headstock for reversing the motion carries the screw bolt away from the tool
at the same time, the journals E and the drum J are elongated, to admit
of the longitudinal movement of the headstock piece, as is necessary for
chasing the screw bolt with a fixed tool. In chasing the longitudinal motion
is supposed to take place from left to right, and the backward longitudinal
movement may be obtained by simply shifting the headstock by means of the
lever N; or instead of this plan, the driving pulley K may be made to produce
the required longitudinal motion by setting it at a slight angle, as seen in
Figure 15. The spindle L is carried in a long tubular bracket piece Q
capable of being adjusted to any small angle upon brackets R, S, upon the
framing, the latter bracket having a segmental slot for the adjustment of the
holding bolt round the other bracket as a centre. When the driving pulley
K is set at an angle in this way, it has a screw action upon the drum J, and

page_text: causes it to move longitudinally as well as to rotate, which combined motion is
peculiarly suitable for the work which this machine is intended to perform.
Having now described and particularly ascertained the nature of my
said Invention, and the manner, in which the same is or may be used
er carried into effect, I may observe, in conclusion, that I do not confine or
restrict myself to the precise details or arrangements which I have had
occasion to describe or refer to, as many variations may be made therefromn
without deviating from the principles or main features of my Invention;
but what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent, is,
First, the general arrangement and construction of machinery, apparatus,
or means for transmitting motion where a quick reversing action is required
and for reversing such motion as herein-before described.
Second, the application and use, in machinery where reversing mechanism
is required, of one or more frictional driving or driven pulleys arranged
upon a single spindle in such a manner that either the driving or the driven
pulley or pulleys may be shifted slightly for obtaining the reversing action,
such shift being effected by turning the support of the shifting pulley or
pulleys upon an axis eccentric to its or their own axis of rotation, as
herein-before described..
Third, the application and use of corrugated, undulated, or angular frictional
surfaces for the transmission of motive power, as herein-before described.
Fourth, the system or mode of effecting the transmission of a reversing
vibratory action to levers or arms for hammers and other purposes, by the
adaptation of a continuously revolving frictional pulley between the concave
and convex surfaces of segmental slots or grooves.
In witness whereof, I, the said James Robertson, have hereunto set my
hand and seal, this Fifth day of December, One thousand eight hun-
drod and fifty-five
JAMES ROBERTSON. (L.S.).