Improvements in the Driving Mechanism of Mechanically Propelled Vehicles.
Year: 1895

page_text: Date of Application, 24th Sept., 1393
Complete Specification Left, 24th June. 1896-Accepted 24th Sept.
1896
Γαμησάκιση, στη σερι., 1990
Complete Specification Left, 24th June. 1896-Accented 24th Sept. 1896
PROVISIONAL SPECIFICATION.
Improvements in the Driving Mechanism of Mechanically Propelled
Vehicles.
We, ERNEST JOHN CLUBBE and ALFRED WILLIAM SOUTHEY both of
16 Elm Street, Gray's Inn Road, London W.C. Electrical Engineers do hereby
declare the nature of this invention to be as follows:-
:-
This invention relates to the driving mechanism of power driven vehicles in
which motion is transmitted from the motor to the driving wheels through the agency
of worm gear.
The present invention has for its object to provide for the overrunning of the
driving by the driven shaft by the acquired momentum of the vehicle as for instance
when stopping or when running free down an incline.
With ordinary worm gear the overrunning of the worm by the worm wheel is
impossible owing to the comparatively slow pitch of the worm and to provide for
this contingency we combine with the worm wheel a form of self acting coupling
which will permit of the worm wheel remaining stationary whilst its shaft continues
to rotate this coupling being adapted both for forward and backward driving and
being self disengaging when driving in either direction.
The preferred form of coupling consists of a male screw on the end of the one
member of the shaft adapted to screw home into the one or other of two corre- •
sponding female screws in a sort of inuff coupling having a sliding connection with the
other member of the shaft so as to rotate therewith whilst capable of longitudinal
motion necessary to cause the male screw to engage in the one or other socket according
to the direction of rotation, the two parts of the shaft being wholly disconnected
when the male screw is midway between the two sockets without being engaged in
either.
In order to avoid liability of the screw jamming when home in its socket there
may be combined with it a sort of dog clutch adapted to be brought into
engagement so as to take the driving strain, by the screwing home of the screw.
In any case the overrunning of the driven part causes the screw to work out of its
socket and run free until thrown into engagement with the one or other socket
according to the direction of driving.
Instead of a screw coupling as above described we may adopt duplicate or
oppositely arranged sets of ratchet and pawl gear adapted for driving in both
directions the one or other being brought into driving engagement by a longitudinal
motion of the muff portion or sleeve carrying the pawls.
In order to avoid the objectionable noise incidental to the slipping of the pawls
over the ratchet teeth when the one part is overrunning the other, means may be
provided whereby the pawls may be lifted out of contact with the ratchet teeth as
soon as they begin to slip.
Dated this 24th day of Sentember 1905

page_text: Improvements in the Driving Mechanism of Mechanically Propelled
Vehicles.
We, ERNEST JOHN CLUBBE and ALFRED WILLIAM SOUTHEY both of
16, Elm Street, Gray's Inn Road, London, W.C. Electrical Engineers, 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 driving mechanism in which motion is transmitted from the
motor or driving shaft to the driven shaft through the agency of worm gear.
The present invention has for its object to provide for the driven shaft over-
running the driving shaft. With ordinary worm gear the over-running of the
worm by the worm wheel is impossible owing to the comparatively slow pitch of
the worm and to provide for this contingency when worm gear is used we combine
with the worm wheel shaft a form of self-disengaging coupling which will permit
of the worm wheel being stopped whilst the driven shaft continues to rotate, this
coupling being adapted both for forward and backward driving and being self-
disengaging when the worm wheel shaft over-runs the worm shaft in whichever
direction the gear may be running.
The invention is illustrated in the accompanying drawings forming part of this
specification wherein Figure 1 represents a longitudinal section and Figure 2 a
cross section of the coupling.
The coupling consists of a male screw A on the end of the one member B₁ of
the worm wheel shaft adapted to screw home into the one or other of two
corresponding female screws C' C³ in a sort of muff or sleeve C having a groove
and feather connection with the other member B2 of the worm wheel shaft so as to
rotate therewith whilst capable of longitudinal motion necessary to cause the male
screw A to engage in the one or other female screw C' or C' according to the
direction of rotation. The two female screws C' C' are separated by a space
sufficient to admit of the male screw being placed midway between the two female
screws without being engaged in either, in which position the two members B' B' of
the worm wheel shaft are wholly disconnected. The worm wheel may be fast on
either member B₁ or B³, the other member being directly geared with the
mechanism to be driven or with the driving wheels of a vehicle, as the case may
be. Supposing the worm wheel to be on the shaft B' and running in the direction
of the arrow, the male screw A bears against the end of the sleeve as shewn and
the members B' B' rotate together as one. Should however B' acquire a greater
speed of rotation than B¹ or continue running after B' has stopped, the sleeve will
screw itself along to the left until C¹ is quite disengaged from A which the
occupies the intermediate space within the sleeve. The sleeve is moved in the one
or other direction in order to cause the one or other screw C¹ or C to engage with
the screw A by a lever D which may be locked in either of its two extreme
positions according to the direction of running and which acts through springs E E
on a bracket F carried by a collar encircling the sleeve C. In the inid-position of
the sleeve and of the lever the stress of the springs would be equal but assuming
the lever to remain in the position shewn in Figure 1 whilst C' is unscrewed from A
by a movement of the sleeve to the left as above mentioned, the spring E will be
put into compression and will tend to re-engage C' with A immediately the speed
of rotation of A in the direction of the arrow exceeds that of B', it being only
necessary that the spring should move the sleeve slightly to cause the screw A to
engage in screw (the rotary motion of the former then causing it to screw
itself home in C¹. By this motion of the sleeve the spring E¹ is compressed as

page_text: shewn in Figure 1 which has the effect of tending to prevent jamming of the screw A
in C¹ and to assist the unscrewing motion when it occurs. The interposition of
springs between the lever D and bracket F does not affect the promptitude with
which screw A engages in C¹ or C, as the case may be, and is necessary in order
that the automatic unscrewing of the sleeve from A at the required moment may
not be prevented by the lever being locked. Thus it will be seen that in the
position shewn in Figure 1 the movement of the sleeve to the left will be permitted
by the compression of the screw E, the action being similar in respect of
spring E' under similar circumstances supposing the screw A to be engaged in C'
for driving in the opposite direction to the arrow.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The combination, with worm driving gear, of a self-disconnecting screw coupling
such as described interposed between the worm wheel and the shaft driven thereby
so as to permit of the driven shaft over-running the worm wheel as specified.
Dated this 24th day of June 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.