Improvements in Change-driving Gear.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Change-driving Gear.
I, FRANK GEORGE HAMPSON, of "Airdale," Southdown Road, Shoreham, in the
County of Sussex, Mechanical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to change driving gear and is applicable to various kinds
of machine tools, and to other forms of driving including self-propelled vehicles;
in fact the gear is applicable in nearly all cases where change driving gear is
required. I will at present describe it as applied to a lathe.
In applying this invention to a lathe I employ a spindle and headstock of
substantially usual construction, and upon the spindle I place a sleeve, which
carries in any convenient manner the appropriate number of driving pulleys or
equivalent, each loose upon the sleeve, but capable of being coupled each to any
of the others, or to the sleeve; the sleeve can also be coupled to the spindle.
I may employ any suitable form of clutch or other mechanism for connecting
and disconnecting the various parts, but the following mechanism is suitable for
the purpose. The lathe headstock may be fitted with the ordinary toothed driving
wheel of the back gear now commonly employed with lathes, and upon this or
otherwise upon the spindle may be fitted a toothed clutch, preferably with a
considerable number of relatively small teeth, pins, or other engaging surfaces; a
suitable part of the sleeve is provided with similar clutch or engaging devices,
and the sleeves may be moved by a clutch lever as will be well understood. The other
engaging mechanism may be substantially similar to that above described.
The clutch levers may be arranged as follows:-
A sliding shaft is carried in suitable bearings and passes through bosses or
equivalent upon each of the clutch levers or arms. In the case of the first of
these clutch arms which is intended to engage or disengage the sleeve and spindle,
the arrangement is such that as the clutch lever operates to engage the clutch, it
also causes the shaft to move longitudinally and carry the other clutch mechanism
with it, so that whatever disposition of the driving mechanism may have been made
it will not be disturbed by engaging the sleeve and spindle. A convenient way is
to provide each clutch jaw which surrounds the travelling shaft with a recess
through which passes the clutch lever and recess the shaft so that the clutch lever
may enter one or other of two recesses appropriated to each clutch so as to fix it
in either of the necessary positions, this applies to the driving clutches, the clutch
jaw of the sleeve and spindle clutch being permanently fixed to the shaft.
In or in connection with the headstock I provide a counter-shaft having
pulleys corresponding with the driving pulleys of the lathe head, but reversed in
position in the wellknown manner, and connecting these various pulleys with
separate belts, bands, or chains, preferably the latter, as the shafts are so near
together and the pulleys may be very small. When the counter-shaft is driven
all these chains etc. operate, but only that one drives whose clutch is then in gear.

page_text: This mechanism being so small can be easily covered in so that the chains may
run in an oil bath.
If desired the clutch mechanism, instead of being upon the lathe spindle as
previously described, may be upon the counter-shaft.
The counter-shaft may be driven by means of a belt or chain pulley, which
may either be rigidly secured upon it or may be connected by a friction or other clutch
so as to be thrown entirely out of gear, no loose pulley being necessary. Preferably
I drive this gear by belt or chain mechanism from below, instead of from above,
and where a number of tools are arranged in the same line, a single shaft may run
underneath the whole of them, and may thus drive them, or this may be the
previously described counter-shaft. This primary shaft, whether it be the counter-
shaft or not, may be driven from a main shaft or a main pulley or equivalent
underneath the floor, or where overhead shafting already exists and must therefore
be used, the first motion will be received by this main driving belt or chain.
Wherever possible I prefer to so box in the mechanism that where chain driving
is employed it may always run in an oil bath..
Where such an arrangement is applicable the counter or primary shaft may be
made adjustable to accommodate the stretch or wear of the chains, and it may
if necessary be formed in separate lengths for this purpose, the various lengths
being connected by some suitable form of universal joint or coupling. Other
means may be employed for tightening the chains such as an idle or jockey pulley,
which may operate automatically by spring or weight, and in some cases the driving
and driven shafts may be upon the same level, so that the chain lying approximately
horizontal or nearly so with the sag of the chain may keep the driving run
sufficiently tight.
Dated this 1st day of April 1898.
£6
BOULT & WADE,
Agents for the Applicant.
I, FRANK GEORGE HAMPSON, of "Airdale," Southdown Road, Shoreham, in the
County of Sussex, Mechanical Engineer, 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:-
:-
This invention relates to change driving gear and is applicable to various kinds
of machine tools, and to other, forms of driving including self-propelled vehicles;
in fact the gear is applicable in nearly all cases where change driving gear is
required. I will at present describe it as applied to a lathe.
In applying this invention to a lathe I employ a spindle and headstock of
substantially usual construction, and upon the spindle I place a sleeve, which.
carries in any convenient manner the appropriate number of driving pulleys or
equivalent, each loose upon the sleeve, but capable of being coupled to it; the sleeve'
can also be coupled to the spindle.
Any suitable form of clutch or other mechanism for engaging and disengaging
the various parts may be employed but the following mechanism. is suitable for.
the purpose Each pulley or equivalent is provided with a number of teeth or
projections which engage, when desired with similar teeth upon a portion of the
sleeve, the two sets of teeth forming a clutch. A similar clutch may be used for
effecting the engagement of the sleeve with the spindle.
In or in connection with the headstock I provide a countershaft having a series of

page_text: puneys or equivalents corresponding to the pulleys upon the spindle, but reversed
in position in the well-known manner.
countershaft in a similar manner to that in which the pulleys are mounted upon
These pulleys may be mounted upon the
the spindle, and the two series of pulleys are operatively connected in pairs say by
5 toothed gear or belts, bands, or chains preferably the latter as the shafts may be
very near together and the pulleys small.
Each pair of pulleys is preferably controlled by a clutch-rod or equivalent cross-
connection so that it may be thrown in or out of gear with the sleeve as desired, and
a similar rod or connection is provided to operate the clutch between the sleeve
and the spindle. The clutch-rods are operated by a shaft which is so arranged that
any particular clutch-rod may be operated as desired, and whatever disposition of
the driving mechanism may have been made, it will not be disturbed by engaging
the sleeve and spindle.
The counter-shaft inay be driven by means of a belt or chain pulley, which
may either be rigidly secured upon it or may be connected by a friction or other clutch
so as to be thrown entirely out of gear, no loose pulley being necessary. Preferably
I drive this gear by belt or chain mechanism from below, instead of from above,
and where a number of tools are arranged in the same line, a single shaft may run
underneath the whole of them, and may thus drive them, or this may be the
previously described counter-shaft. This primary shaft, whether it be the counter-
shaft or not, may be driven from a main shaft or a main pulley or equivalent
underneath the floor, or where overhead shafting already exists and must therefore
be used, the first motion will be received by this main driving belt or chain.
Wherever possible I prefer to so box in the mechanism that where chain driving
is employed it may always run in an oil bath, or an oil bath may be formed in the
frame or bed of the machine tool or other device to which the gear is applied.
Where such an arrangement is applicable the counter or primary shaft may be
made adjustable to accommodate the stretch or wear of the chains, and it may
if necessary be formed in separate lengths for this purpose, the various lengths
being connected by some suitable form of universal joint or coupling. Other
means may be employed for tightening the chains such as an idle or jockey pulley,
which may operate automatically by spring or weight, and in some cases the driving
and driven shafts may be upon the same level, so that the chain lying approximately
horizontal or nearly so with the sag of the chain may keep the driving
sufficiently tight.
"
run
. In the accompanying drawings which illustrate one construction of change
speed gear according to this invention, applied to a lathe :-
the
Figure 1 is a longitudinal vertical section, through the headstock.
Figures 2 and 3 are sections on the lines 2--2 and 3-3 respectively of Figure 1.
Figures 4, 5 and 6 show in plan, and on a larger scale, details of a portion of
gear in several positions, and
Figure 7 is a side elevation showing the headstock in position upon a portion
of the bed of a screw-cutting lathe.
Like letters indicate like parts throughout the drawings.
A is a frame or casing serving to support and partly enclose the various parts
which constitute the headstock. B is a spindle forming the usual mandril of the
athe, it is supported in coned bearings B¹ in the case A. Upon the mandril B
nd free to rotate and slide upon it is a sleeve C screwed as at C1, C2, C3. Four
anged sleeves D, DI, D2, D3, are screwed upon the portion C of the sleeve C and
spur-wheel E having an extension in the form of a sleeve is screwed upon the
ortion C A lock-uut F upon the screwed part C3 of the sleeve C serves to
revent the spur-wheel E from becoming unscrewed. The thread in the spur-
heel E is left-handed. A gear wheel E is also provided, mounted directly upon
he mandril B. Four chain-wheels H, H', H2, and H³ are mounted free to rotate
nd to move longitudinally upon the sleeves D1, D2, D3 and E¹ respectively, and
e boss of each of these chain-wheels H, H1, H2 and H³ is furnished with a recess

page_text: as ai h to accommodate one of a series of clutch rods, J, J, J³ and J.
recess is formed upon the sleeve ]) to receive a clutch rod J.
A similar
Upon the left-hand side of each of the sleeves D,D1, D2 and 13 a series of pro-
jections or teeth K is provided, and upon the right-hand sides of the chain--
The adjacent sets of pro-
wheels H, H, H2 and H are similar projections L.
jections L, K, form clutches by means of which any one of the chain-
wheels H, H1, H2, H3, may be engaged with its corresponding sleeve and consequently
to the main sleeve C.
In order that, when desired, the sleeve C may be operatively connected with the
mandril it is provided with a set of projections L' which co-operate with a
corresponding set K¹ to form a clutch similar to the clutches L, K. The pro-
jections K¹ are formed upon the side of a toothed wheel M which forms one of the
wheels of the back gear and is keyed, as at m, to the mandril B.
N is a countershaft supported in oil-tight eccentric bearings N in the case A.
It is provided with a sleeve carrying a series of sleeves 01, 02, 03 and 0+, and
chain-wheels P, P', P2 and 13 which are arranged with clutches in a manner
The sleeve O
substantially the same as described with reference to the mandril B.
is capable of longitudinal motion upon the shaft N but always rotates with it,
through the action of a coupling 0. The bosses of the chain-wheels P, P1, P2, P3,
are recessed as at p to accommodate the other ends of the clutch rods, I, J, JB, J4,
and the sleeve O' has a similar recess to receive the clutch rod J.
The countershaft N is driven in any desired manner from the source of power.
Each of the chain-wheels upon the countershaft N is opposite to one of the chain-
wheels upon the mandril B, and is geared to it by a driving chain as at Q (Figure 2).
The recesses and p in the bosses of each pair of chain-wheels receive opposite ends
of one of the clutch rods J, J2, J3 or 4 and the sleeves C and O are connected in a
similar manner by means of the rod 3 the ends of which enter the recesses h and p
in the screwed sleeves 1 and 01 respectively.
which
Each of the clutch rods J, J, 12, 13, 1, is provided with an
arm
terminates in a box or frame J. Each arm J is connected only to its own
particular clutch-rod and passes freely through slots or openings in the others e.g.
the arm J which is connected to the clutch-rod J2 (Figure 4) passes freely through
the clutch-rods J and J
Through the interior of the frames J6 a shaft R passes having a projection or
cam R¹ upon it; a recess R2 is formed in the shaft R opposite to the cam R'.
The shaft R is mounted eccentrically in a bush R³ (Figures 5 and 6) which is
carried in a bearing R in the side wall of the case A. A handle R with a spring
controlled stop R is attached to the bush R³, and two hollows A' are formed in
the case A to receive the stop R6, so that by turning the handle R³ the shaft R
may be caused to move bodily in a lateral direction in the case A, and by means of
the stop R6 and the hollows A¹ may be fixed in either of its extreme positions. The
horizontal dimension of the interior of the frames J6 is approximately equal to
the diameter of the shaft R, so that the lateral movement of the shaft, causes a
corresponding movement of the arms J which accordingly move their respective
clutch rods J, J, J², J3, J. The effect of this is to cause the sleeve C to engage or
disengage with the mandril B-by means of the clutch L'K-and to move the
sleeve longitudinally upon the countershaft N. This occurs however without
altering the relative positions of the chain-wheels and clutches.
Rs are
The shaft R is capable of longitudinal motion in the bush R³. This is necessary
in order to bring the cam R' in line with any one of the frames .J6. A handle R7 is
provided in order that the shaft may be moved in the bush R³, and grooves
turned in the shaft in such a position that when a spring-catch R is in engagement
with one of the grooves R8 the cam R¹ is inside one of the frames J. As illustrated
in Figure 4 the shaft R is withdrawn as far as possible and the cam is inside the
frame J which operates the clutch rod J. The cam R¹ never enters the first
frame Jo, i.e. that one connected to the clutch rod J, because that clutchi rod is

page_text: never required to move by itself, relatively to the other clutch rods and is therefore
only operated by the lateral movement of the shaft R.
The bearings N of the countershaft N being made oil-tight, oil may be placed
in the lower portion of the case A so that the driving chains Q are constantly
Iubricated.
The arrangement of back gear as follows:-
A sleeve S (Fig. 1) carries two wheels S2 and S3 which engage with the wheels M
and E respectively in a manner similar to the usual arrangement of back gear. The
sleeve S rotates upon a spindle S which is carried in eccentrics S in the case A,
and is provided with a handle-S and a spring socket S in order that the gear
wheels Sand Smay be readily placed in or out of engagement with the wheels M.
and E and kept in the desired position.
Gear wheels for screw cutting are shown attached to this improved headstock in
Figures 1, 2 and 7. Two gear wheels T and T are mounted at opposite ends of
Ja shaft T2 carried in a bearing T in the case A. A triangular plate U is pivotted
round the shaft T2 and carries two gear wheels and U. This plate U is con-
trolled by a lever W which slides in the case A as at W. By sliding the lever W
inor out the plate U is turned upon the shaft T so that: (a) Neither of the
wheels U or U³ engage with the wheel 12; (b) The wheel U engages with the
wheel E2 and drives the wheel T in one direction, or (c) The wheel U2 gears with
the wheel E2 and drives the wheel U¹ and through it the wheel T in the other
direction.
The motion of the wheel T is transmitted through the shaft T to the wheel T'
which by means of wheels T and T drives the leading screw X.
The lever W may be held in either of the three positions by means of the
holes W² and the pin W3.
The operation of this improved headstock is as follows, assuming the gear to be
in the position illustrated in Figure 1, ie all the clutches are inoperative:
If it is desired to drive the mandril B without the use of the back gear, the
handle R is turned until the eccentric bush R³ has rotated in the bearing R4
and carried the shaft R into the position shown in Figures 4 and 5, i.e. into its
extreme right-hand position. This movement of the shaft R causes all the
frames J to move and consequently all the clutch-rods J, J1, J2, J3, J* move also
and the sleeve C moves longitudinally upon the mandril B and is geared with it
through the clutch L.K. A corresponding longitudinal motion of the sleeve O
takes place upon the countershaft N. No relative motion of the clutch-
rods J, J, J2 J3, J has however taken place and therefore the clutches controlling
the chain wheels are still inoperative. If now the handle R be turned as in Fig. 5
the cam R¹ moves the particular frame J that it is within, and consequently the
clutch-rod connected with that frame moves and one pair of chain wheels is thrown
into engagement. As illustrated in Figure 5 the longitudinal position of the
shaft R, is such that the movement of the cam R¹ would have caused the clutch
rod J to move, and would therefore have thrown the chain wheels H and P into
operation.
It should be observed that when the shaft R is rotated and the cam R¹ operates
upon one of the frames J, the left hand portion of that frame enters the recess R² in
the shaft R (Figure 5) and thus the engagement of any other pair of chain wheels
with the sleeve is rendered impossible until the shaft R has been turned back, and
the clutch at present in action, disengaged.
When the back gear is employed, the operation is as described above except that
the shaft R is not moved laterally but is kept in the position illustrated in Figure 6
so that the sleeve C is not directly engaged with the mandril B. The back gear
wheels S2 and S3 are placed in gear with the wheels, M and E upon the sleeve C
by turning the shaft S and its eccentrics S and any desired pair of chain wheels
is thrown into operation as above described.
Any slackness due to wear or stretch in the driving chains may be taken up by
turning the eccentric bearings N¹ in which the countershaft N is carried.

page_text: It is obvious that various modification may be made in change-speed gear accord-
ing to this invention without departing from the spirit thereof; for instance,
the pulleys may be in the form of gear wheels directly engaging with each other
without the use of belts, bands or chains. It will readily be seen, too, that gear
according to this invention is very suitable for use in conjunction with an electric
motor, the motor driving the countershafts of one or more machine tools, and thus
dispensing with all overhead shafting, belts etc.
Modifications may also be made in the gear for controlling the sleeves CO and
the pairs of related pulleys HP, HP, HP, and HP; for instance, I may effect
the simultaneous adjustment of the group of clutch rods JJ1 J2 J3 J4 by a shaft R
movable laterally in a manner hereinbefore described, whilst I may cause the
subsequent rotation of that shaft R to effect the engagement of the pulleys H
and P for instance, or any of the other pairs of pulleys, with their respective sleeves
by clutches which need not depend for their action upon endwise movement of
the pulleys; further it is practicable to dispense altogether with the clutch rod J.
connecting the two sleeves, for with that rod absent any movement given to remain-
ing four clutch rods J1 J2 J3 J4 and tending to move the pulleys on the sleeves will
instead have the effect of moving the pulleys and sleeves in company instead of
in relation to each other, for the reason that it would be necessary, for any relative
movement of the pulleys and sleeves to take place, that the four series of clutch
teeth KL should simultaneously have the teeth in each pair opposite the recesses
between the opposing teeth, and the balance of chances is against the occurrence of
such particular and precise juxtaposition. From the foregoing it will be seen
that with the first clutch rod J dispensed with, the initial lateral movement of the
shaft R will in all probability have the effect of forcing one or more of the series
of clutch teeth KL into abutment against each other instead of into engagement
and consequently the sleeve C will be moved endwise into engagement with the
mandril B; the individual clutch rods J1 J2 J3 J4 can afterwards be moved to
engage individual pulleys HH' H2 H3 H4 with that sleeve and to move the related
pulleys of the series P, as may be necessary.
It is not necessary that the cross connection between each pair of pulleys HP
should take the form of clutch rods such as J; for instance if the pulleys Hand P
were spur wheels with shrouded teeth operatively connected by an intermediate
pinion, movement of the intermediate pinion in the line of its axis would move
with it the toothed wheels H and P because the teeth on the intermediate pinion
would bear, in such lateral movement, upon the shroudings of the teeth of the
wheels to which it is geared; in this instance the intermediate pinion constitutes
the cross connection.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In the head of a lathe or similar tool the combination with the main shaft or
spindle carrying a series of chain wheels or pulleys of different diameters of a
counter-shaft also carrying a set of chain-wheels or pulleys of different diameters
and a series of chains connecting corresponding pulleys upon the two shafts.
2. In change driving-gear the combination of a driving spindle N pulleys P
a sleeve such as O a driven spindle such as B pulleys such as H a sleeve such as C
and its clutch and clutches for each of the pulleys substantially as and for the
purpose described.
3. In change driving-gear of the kind described comprising sleeves such as CO
and a clutch such as K'L' the employment of cross-connections such as J¹ for
pairs of pulleys such as HP in combination with or without a cross-connection
such as J for the sleeves CO all the cross-connections being movable simultaneously
and also individually for the purpose set forth.
4. In change driving-gear of the kind described the combination with the cross-
connections between parts supported by the driving and driven shafts of a spindle

page_text: in an eccentric bearing and having projections operatively connected with the
clutches appropriated to different pairs of related pulleys such as HP.
5. In change driving-gear of the kind described the combination with the cross-
connections between parts supported by the driving and driven shafts of a spindle
in an eccentric bearing and having a projection such as R¹ and a recess R² and
boxes or frames J6, fitting the spindle and each connected with an individual
cross-connection for the purpose described.
6. The complete change driving-gear with or without the casing A substantially
as and for the purpose described and illustrated in the accompanying drawings.
7. In change driving-gear of the kind described the combination and arrange-
ment of parts constituting the control mechanism substantially as and for the
purpose described and illustrated in Figures 3, 4, 5 and 6 of the accompanying
drawings.
Dated this 14
T
1
1000