improvements in or reisting to Speed Changing Gear.
Year: 1898

page_text: improvements in or reisting to Speed Changing Gear.
We, CHARLES MCROBIE TURRELL and FREDERICK HENRY DE VEULLE, both of
Glenelg, Grosvenor Road, Coventry, in the County of Warwick, do hereby declare
the nature of this invention to be as follows:-
The object of this invention is to provide a simple and efficient speed change
gear which shall operate without noise or unnecessary shock.
A change speed gear constructed according to this invention may be provided
with any number of "speeds" whilst it is compact and particularly suited for
application to motor vehicles, though not limited, in its application, to these.
In carrying out this invention the various speed wheels are mounted free on
the driven shaft and are always in mesh with corresponding gear wheels fast upon
the driving shaft. The driven shaft which is capable of endwise movement is
provided with a spring catch or feather and each of the gear wheels carried by
the driven shaft is provided with a recess into which the spring catch enters
when brought into alignment with the same.
The spring catch or feather is of such a shape that if, when it is in engage-
ment with one of the speed gear wheels, the driven shaft is moved in a longi-
tudinal direction, the catch will automatically become disengaged from the
wheel and will be forced back against its spring into the shaft. If the longi-
tudinal movement of the driving shaft is then continued the catch will again
rise, when in alignment with the recess of the wheel adjacent to the first, and
will thus engage this second wheel with the shaft the first being again free. The
longitudinal movement of the shaft may be effected by any convenient means and
the whole of the gear may be enclosed in a case or covering.
Dated this 25th day of October 1808
BOULT & WADE,
Agents for the Applicants.
Improvements in or relating to Speed Changing Gear.
We, CHARLES MCROBIE TURRELL and FREDERICK HENRY DE VEULLE, both of
Glenelg, Grosvenor Road, Coventry, in the County of Warwick, 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 follow-
ing statement:-
The object of this invention is to provide a simple and efficient speed change
gear which shall operate without noise or unnecessary shock.
A change speed gear constructed according to this invention may be provided

page_text: with any number of "speeds" whilst it is compact and particularly suited for
application to motor vehicles, though not limited, in its application to these.
In carrying out this invention the various speed wheels are mounted free on
the driven shaft and are always in mesh with corresponding gear wheels fast upon
the driving shaft. The driven shaft which is capable of endwise movement is
provided with a recess or keyway, and each of the gear wheels mounted upon it
carries a spring controlled feather or key adapted to engage with the said key-
way and shaft, or in place of the key-way or recess the shaft may carry a spring
catch or feather, and each of the gear wheels carried by the driven shaft is pro-
vided with a recess into which the spring catch enters when brought into align-
ment with the same..
The spring catch or feather is of such a shape that if when it is in engagement
with one of the speed gear wheels, or with the shaft, the shaft be moved in a
longitudinal direction, the catch will automatically become disengaged from
the wheel or shaft and will be forced back against its spring into said wheel
or shaft. If the longitudinal movement of the driving shaft is then continued the
catch will again rise, when in alignment with the recess of the wheel adjacent to
the first and will thus engage this second wheel with the shaft, the first being
again free or in case of the alternative construction being used the key or
feather in the next gear wheel will fall into the recess in the shaft and thus throw
its wheel into gear. The longitudinal movement of the shaft may be effected
by any convenient means and the whole of the gear may be enclosed in a case or
covering.
In the accompanying drawings:
Figure 1 is a central longitudinal section of a shaft and speed change gear con-
structed according to one method of carrying out this invention.
Figure 2 is a section on the line 2-2 of the same.
Figure 3 is a central longitudinal section of a shaft and its speed change gear
constructed according to a second method of carrying out this invention, and
Figure 4 is a transverse section of Figure 3 on the line 4-4.
Like letters indicate like parts throughout the accompanying drawings.
The change speed gear is preferably mounted upon the driven shaft A of a
motor or other mechanism, such shaft being mounted in convenient bearings in
any well-known manner. Any number of gear wheels B B may be mounted
free unon the shaft A. two only however, being shown in the drawings. The
shaft A is provided with a recess or key-war A', the cross section of which is
approximately semi-circular in the longitudinal direction of the shaft, and whilst
the end face A2 of the recess is flat, situated lengthwise of the shaft and is tan-
gential in its relation to the axis thereof, the recess is cut away and made to
become shallow gradually towards its opposite end so as to merge easily at that
end into the cylindrical surface of the periphery. Moreover the groove is situ-
ated circumferentially on the shaft and therefore the gradual shallowing of the
groove, taken together with the fact that it is approximately semi-circular in
transverso section causes it to mergo easily at its sides into the surface of the
shaft, as well as at one of its ends. Each of the gear wheel B B is provided
with a slot Bª communicating with and extending radially from the central bore
of the hub. Within this slot B2 is mounted a key or feather C, such key or
feather being free to slide within the slot Bª. The end C¹ of the key or feather C
is curved in the same manner as the recess A1 in the shaft A. and is also curved
at its face C to fit the outer circumference of the shaft A. The rear part of the
key is slotted at C2, within which is placed a spiral spring C held in place in the
wheel at one end by means of a bridge-piece and stud C5.
To prevent displacement of the key C and its spring C³, a thin disc D of metal
or other suitable material is mounted on the shaft between each of the adjacent
gear wheels. so that the key in one is prevented from becoming displaced in such
a manner as to project from the side of the wheel and foul the recess or other
part of its adjacent gear wheel. The operation of this device is as follows:-

page_text: If the shaft, A, shown in the drawings as engaged with the gear wheel B, is
moved endwise in the direction indicated by an arrow, the key C in the wheel B
will be forced up into this slot B against the action of the spring C+, and will
thus break all connection with the shaft A, and leave the wheel B to run idle
upon the same.
If now the endwise motion of the shaft A be continued the recess A¹ will be
brought vertically under the slot B of the wheel B', and the key C will be
forced down by its spring C+, so that it engages with the shaft A and forms a
rigid connection between the gear wheel and its shaft. It is obvious that this
operation may be repeated with any number of speed gear wheels it may be found
convenient to use.
The key-way A¹ is cut away on one side as mentioned above to permit of the
easy entrance of the key or feather C, but this formation also permits the use of
a second recess or key-way A4, which may be used for reversing. It is easy to
be understood that if the gear wheel on the shaft is revolving in the direction in-
dicated by the arrow (Figure 2) its key will engage with the key-way A', whilst
it will slide over the key-way A4, but if the sense of the rotation of the wheel he
reversed, its key will pass freely over the recess A', but will engage with the
recess A+.
The modification described with reference to Figures 3 and 4 shows the con-
verse of the arrangement described above; in this case the key C is mounted in
a slot formed in the shaft A and provided with a flat spring C, which always
tends to project the end of the key above the outer circumference of the shaft.
The spring C is mounted in a suitable recess in the shaft A, so that it may be
free to move the required amount when the key C is depressed without fouling
any gear wheels carried on the shaft.
Each of the gear wheels B B₁ carried by the shaft A is provided with a key-
way or recess B³ of similar formation to that in the shaft A of Figures 1 and 2.
In this construction the discs D) are not required, as there are no parts within
the gear wheels which it is necessary to keep in place. Each gear wheel may
also be provided with a second recess B4 for engagement with the shaft in the
opposite sense to that of B3 as described with reference to the former arrangement.
The operation of this device is as follows:
When the shaft A is moved in an endwise direction as indicated by an arrow,
the key C is forced back against its spring C until it lies wholly within the
shaft A, and is thus out of engagement with the wheel B, so that the same is
free to run idle. If now the endwise movement of the shaft be continued until
the key C is brought under the recess B³ of the wheel B', the key will rise under
the action of its spring, so that the wheel and shaft become immediately engaged.
Should the direction of rotation of the wheels B B¹ be reversed, it will be under-
stood that the key C will engage with the recess B in any one wheel in place
of the recess B3.
To avoid undue friction or cutting by means of the key coming into contact
with the hubs or bearings of the wheels B B¹ when not in engagement with the
same, its end or nose may be curved to the same radius, as that of the bore of the
wheels.
This invention may be further modified by providing the shaft A with a longi-
tudinal slot extending throughout that portion upon which the gear wheels are
mounted, and providing means by which the key C with its spring C may be
made to traverse the slot, and be thus brought into engagement with any one of
the gear wheels. When arranged in this manner the shaft may if desired be made
hollow, the slot being carried through on one side only so that the connecting
rod or other device by which the key is operated may be arranged within the shaft.
It is also obvious that the gear wheels may be made to slide upon the shaft,
the latter in this case not being moved in an endwise direction, and it will fur-
ther be understood that although toothed wheels have been referred to throughout
the specification and illustrated in the drawings, the invention is by no means
*:

page_text: limited to toothed gearing, as it is obvious that pulleys driven by belts may equally
well be arranged to be operatively connected with, or disconnected from the shaft
in the manner described, so that the word "pulley" used in the following claims
will be understood to cover toothed wheels whether chain driven or otherwise.
Although this change speed mechanism has been described as mounted upon a
driven shaft, the wheels always revolving upon the same shaft, it is obvious that
the same device may, if desired, be applied to a driving shaft in which the shaft
revolves, the wheels when not in engagement being either stationary or running
idle upon it.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In a speed changing mechanism a spring controlled key carried either by
the shaft or the wheel to be caused to turn with the shaft such key automatically
engaging or disengaging the wheel and shaft when the one is moved relatively
to the other in a direction endwise of the shaft substantially as described.
2. In a speed changing mechanism the combination with a shaft having gear
wheels mounted free upon it each carrying a spring controlled detent C, of a cir-
cumferential recess such as A' having an end face such as A2 and being curved
in cross section and made to become shallow gradually from the face A2 towards
its opposite end to receive and engage the detent C substantially as and for the
purposo described.
3. In a speed changing mechanism the combination with a shaft having gear
wheels mounted free upon it each carrying a spring controlled detent such as C
of two recesses such as A¹ A' adapted to receive the detent whereby driving may
be effected in either direction substantially as described
4. In a speed changing mechanism the combination with a shaft having a spring
controlled detent such as C of a pulley Bhaving a slot such as B3 with or without
a recess B substantially as and for the purpose described and illustrated in the
accompanying drawings.
5. In a speed changing mechanism the combination with a shaft of a spring
controlled detent such as C and a series of pulleys each having a slot such as B³
adapted to successively receive the detent substantially as and for the purpose
described.
6. In a speed changing mechanism the combination with the shaft A of a longi-
tudinal slot traversed by a spring controlled detent and of a series of pulleys each
having a recess such as B³ with or without a recess such as B4 adapted to success-
ively receive the detent substantially as and for the purpose described.
7. In a speed changing mechanism the combination with a shaft having a
recess such as A¹ of a pulley such as B having a slot such as B3 and a spring
detent such as C substantially as and for the purpose described and illustrated
in the accompanying drawings.
8. In a speed changing mechanism the combination and arrangement of parts
described and illustrated in Figures 1 and 2 of the accompanying drawings.
9. In a speed changing mechanism the combination and arrangement of parts
described and illustrated in Figures 3 and 4 of the accompanying drawings.
Dated this 24th day of August 1800
BOULT & WADE,
Agents for the Applicants.