Improvements in Speed Changing Gear, the Invention being particularly applicable to the Driving Mechanism of Motor Road Vehicles.
Year: 1899

page_text: Improvements in Speed Changing Gear, the Invention being
particularly applicable to the Driving Mechanism of Motor
Road Vehicles.
I, JOSEPH CHARLES EUGENE MATHIEU (commonly called EUGÈNE MATHIEU), of
31, Avenue Parmentier, Paris, in the French Republic, Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to an improved speed changing device having its gear-
ing parts in permanent gear and being more especially applicable for motor road
vehicles.
In view of the highly advanced stage which the motor car industry has
reached at the present time, it would be useless to enumerate the advantages
offered by speed changing devices with their gearing parts in permanent gear
over other devices of this kind, where the gearing wheels or the like are only
thrown into gear, when they are required to transmit power from the driving
mechanism to the receiving mechanism, whereas at other times they are out of
gear.
Speaking generally, former speed changing mechanisms of the kind here in
question, that is to say, such with their gearing parts in permanent gear, com-
prise a series of gear wheels of different diameters, mounted loosely side by side,
but at a comparatively great distance apart, upon a common shaft, generally the
receiving shaft, and gearing respectively, with corresponding pinions, all keyed
upon the other shaft, generally the driving shaft. According as, by an appro-
priate driving mechanism, either one or the other of the loose gearing wheels
is firmly connected with its shaft, the latter will turn at the rate corresponding to
the ratio of transmission between this gear wheel and its pinion. There is
generally also provided a gear wheel for back motion, such as an intermediate
wheel keyed between this gear wheel and its pinion, in order to change the
direction of rotation.
There are speed changing mechanisms of this kind in existence, in which the
device effecting the engagement of the different loose gear wheels with their
shaft which is hollow is located in said shaft, and in which a longitudinal dis-
placement of this said device effects the bolting or keying of the gear wheel on
to its shaft.
The apparatus forming my invention is also based upon these principles; but
as I have above indicated, it is distinguished from former analogous apparatus
by various points which I will now explain.
In carrying out my invention I use a hollow shaft, upon which are loosely
mounted say two gear wheels one for each speed desired to be obtained for for-
ward movement and one for each speed of back motion. A driving shaft carries
an equal number of pinions always in gear with their respective gear wheels.

page_text: In order to reduce friction and wear and tear, liable to take place between
the hollow shaft and the loose gear wheels thereon, the hub of these gear wheels
is furnished with a socket or sleeve or the gear wheels may be adapted to roll
upon balls or rollers, interposed between them and their shaft.
The gear wheels for the back motion, gear indirectly with their pinions by
intermediate wheels with these loose gears for the purpose of changing the direc-
tion of rotation.
The hollow shaft is traversed by a bar capable of a longitudinal movement in
its bearing which movement is determined by the action of the operator or con-
ductor. The bar has inclined surfaces which during its longitudinal movement
act upon radial bolts, which are caused to move in or out radially, and this
radial movement of the bolt 1 utilize for causing the loose gears to be secured
or held as desired onto the hollow shaft which they are intended to drive.
The grooves or inclines of the bar engage the ends of rods or pins which act
upon bolts hereafter described.
When the bar is caused to move forward or backward in a longitudinal direc-
tion, these inclined planes will push the rods and the bolts radially toward the
exterior, or will allow them to return toward the centre, if any force is acting
thereon in this direction as the case may be.
The loose gear wheels are grouped in pairs, each pair being controlled by the
bolts of one and the same bolt holding frame.
Between the hubs of the two gear wheels, the hollow shaft forms a square
upon which a block or piece is fitted, which serves as a guide and a support for
the two bolts. This piece turns with the hollow shaft. The pins or rods before
referred to are located and guided on this piece and their inner ends pass through
a corresponding hole of the hollow shaft and rest on one of the inclines of the
bar. The rods at the other end bear against the inner face of the bolts which
form transverse pieces of a right angular frame capable of being radially dis-
placed, and guided in this movement by the bolt holder before referred to. In
order to permit of the mounting of this device, the sides of the frame are con-
nected with the transverse pieces or bolts in a removeable manner; for instance
by means of screw bolts.
The frame thus mounted can displace itself radially in its guide, in one direc-
tion or the other, according as under the action of the inclines of the bar, the
rods or pins thrust the frame in one direction or the other.
•
Each loose gear wheel carries upon the side lying toward the bolting device,
and as far from the centre as desired, a shoulder by preference formed with the
wheel but it may be secured thereto. One transverse piece facing this side of
the wheel has a shoulder, adapted to move in a corresponding groove of the
bolt holder, the other transverse piece carries upon its side which faces the other
wheel a shoulder also adapted to move in a groove of the bolt holder.
Thus according to the position occupied by the frame in a radial direction,
one or other of the shoulders of the bolt holder can engage with one or other of
the shoulders of the wheel and so will effect the bolting or keying of a wheel
to the hollow shaft, the other wheel remaining loose.
In the device described when the frame occupies its central position it is not
operated on by the centrifugal force, or rather, the two diametrically opposite
halves of the frame being perfectly equipoised, the effects of centrifugal force
developed by the rotation of the frame around its axis, balance each other.
When the frame is driven outwardly on one side by the effect of the displacement
of the bar the two resultants of the centrifugal force no longer equipoise each
other but the general resultant is annihilated by the bar which receives the
thrust from the rod or pin which lies nearest to the centre. The effort to be
overcome, in order to return the frame, is very small, being equal only to the
difference between the two directly opposite resultants which difference can never
reach a high maximum by reason of the construction of the apparatus.
In another form of my invention where springs are employed the bolt holder

page_text: is formed as a circular disc, mounted on a square, or otherwise keyed on the
hollow shaft between the two loose wheels of one pair, as previously described.
This disc serves as a guide for the radial bolts actuated by the inclined planes
or cams of an axial bar moveable longitudinally also as described.
The bolts act directly upon the bushes of the wheels to be thrown into gear.
and carry for this purpose shoulders which are adapted to move in appropriate
guide grooves of the disc. To facilitate the construction, the bearings for the
bolts and their shoulders are bored and sunk radially into the disc, the latter
is then surrounded by a ring.
As the bolts are independent of one another, the centrifugal force would per-
manently tend to drive them out. When the device is turning, it is therefore
necessary to oppose to it a force which has the permanent tendency to return the
bolt toward the centre, in such a manner that the same is under the influence of
the inclined plane or cam of the axial bar which is capable of driving it toward
the periphery, while it will automatically return under the action of the said
force, in spite of the centrifugal force.
For this purpose the bolts are made hollow and contain a spring which receives
its support at one end either directly, or indirectly by the intermediary of a
plug acting against the inner face of the ring above referred to, and the other
end of which exerts a pressure greater than that of the centrifugal force against
the bottom of the bolt, and thus tends to constantly drive the same toward the
centre.
I may employ two oppositely arranged bolts instead of one as described and
in this case the bolts of the wheel are thrown into gear by their shoulders with
the bushes of the wheel, which they thus key to the shaft, while the inclines on
the bar are so arranged as to drive the bolts toward the exterior and throw the
shoulders out of engagement with the bushes of the wheel which thus becomes
again loose, and according to one arrangement the cams or further inclined faces
arranged at an angle of 90 degrees relatively to the first inclines may enable a
set of bolts placed at 90 degrees relatively to those first mentioned to return to-
ward the centre under the action of their springs, whereby the opposite bolt will
be thrown into gear for an opposite wheel.
With this modification all that is necessary to change the speed from the
maximum to the minimum, is to slide the bar in the proper direction for succes-
sively passing the different pins over the inclined planes or cams, so as to
gradually pass from the higher to the lower speed, and that a single arrangement
of inclined planes or cams is thus sufficient providing that the displacement of the
longitudinal bar be sufficiently great.
:
According to another arrangement the spiral springs may be replaced by curved.
eaf springs having a tendency to drive the bolts toward the centre,
It is evident in all cases the bar must turn with the shaft containing the same.
The operating mechanism therefore must be so connected with this bar as not
o impede this movement.
COMPLETE SPECIFICATION.
Improvements in Speed Changing Gear, the Invention being
particularly applicable to the Driving Mechanism of Motor
Road Vehicles.
I, Joseph Charles Eugène Mathieu (commonly called EUGÈNE MATHIEU), of
31, Avenue Parmentier, Paris, in the French Republic, Engineer, do hereby

page_text: declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to an improved speed changing device having its gear-
ing parts in permanent gear and being more especially applicable for motor road
vehicles.
In view of the highly advanced stage which the motor car industry has
reached at the present time it would be useless to enumerate the advantages
offered by speed changing devices, with their gearing parts in permanent gear
over other devices of this kind where the gearing wheels or the like are only
thrown into gear when they are required to transmit power from the driving
mechanism to the receiving mechanism whereas at other times they are out of
gear.
I have represented in the accompanying drawing a speed changing mechanism
embodying my invention and certain constructional modifications which may
be applied thereto.
Figure 1 is a section of one part of my apparatus.
Figure 2 is an end elevation thereof, certain parts being represented in section.
Figure 3 is a plan view, certain parts being broken away and others shown
in section.
Figure 4 is a perspective view of the bolting or keying device.
Figure 5 is a similar section to Fig. 1 but showing a modification.
Figure is an end elevation showing the bolt holding frame in another
modification.
Speaking generally former speed changing mechanisms of the kind here in
question, that is to say, those with their gearing parts in permanent gear, com-
prise a series of gear wheels of different diameters mounted loosely side by side,
but at a comparatively great distance apart upon a common shaft, generally the
receiving shaft, and gearing respectively with corresponding pinions all keyed
upon the other shaft, generally the driving shaft. According as by an appro-
priate driving mechanism either one or the other of the loose gearing wheels.
is firmly connected with its shaft the latter will turn at the rate corresponding to
the ratio of transmission between this gear wheel and its pinion. There is
generally also provided a gear wheel for back motion, such as an intermediate
wheel keyed between this gear wheel and its pinion, in order to change the
direction of rotation.
There are speed changing mechanisms of this kind in existence in which the
device effecting the engagement of the different loose gear wheels with their
shaft, which is hollow, is located in said shaft, and in which a longitudinal dis
placement of this said device effects the bolting or keying of the gear wheel on
to its shaft.
The apparatus forming my invention is also based upon these principles but
as I have above indicated, it is distinguished from former analogous apparatus
by various points which I will now explain.
In Figs. 1, 2 and 3. A is the hollow receiving shaft upon which are loosely
mounted-the gear wheels B B (of which for the sake of simplicity I have only
represented two) one for each speed desired to be obtained for forward movement
and one for each speed of back motion. The driving shaft D which carries the
pinions CC are always in gear. with the gear wheels B B¹.
In order to reduce friction and wear and tear liable to take place between
the shaft A and the gear wheels B B the hub of these gear wheels is furnished
with a socket or sleeve 60, or the gear wheels may be adapted to roll upon balls
or rollers interposed between them and their shaft A.
The gear wheels for the back motion gear indirectly with their pinions by
intermediate wheels with these loose gears for the purpose of changing the direc-
tion of rotation (this not being represented in the drawing).

page_text: use the wheel B for example to be firmly connected with or key
to the hollow shaft A, by the means which will be hereinafter indicated, th
shaft A will turn at the rate resulting from the relation of the diameters betwe
the wheel B and its pinion C while the other wheel BI actuated by its pinion
5 will turn loosely upon the shaft A though remaining permanently in gear.
The keying of one of the wheels B or B¹ to the hollow shaft A is effected
means of the device represented in perspective view in Fig. 4.
The construction and operation of this mechanism is as follows:
The hollow shaft A is traversed by a bar E capable of a longitudinal move
10 ments in its bearing which movement is determined by the action of the operato
of the mechanism by means of a suitable operating part, such as a lever, a han
wheel or the like, through the intermediary of any appropriate connecting part
The bar E has inclined surfaces which during its longitudinal movement ac
upon radial bolts which are caused to move in or out radially and this radial
movement of the bolt I utilize for causing the loose gears to be secured or held
as desired onto the hollow shaft which they are intended to drive.
As indicated in Figs. 1 to 4 and particularly in Fig. 1, the bar is formed
with two longitudinal grooves or inclines which engage the ends of rods or
pins ff which act upon the bolts F F These grooves have between them a
webe which forms at the points e¹ e²e a succession of inclined planes.
:
When the bar E is caused to move forward or backward in a longitudinal
direction, these inclined planes will push the rods f and consequently the bolts F
radially toward the exterior, or will allow them to return toward the centre, if
any force is acting thereon in this direction.
The loose gear wheels B B are grouped in pairs, each pair being controlled
by the bolts of one and the same bolt holding frame. Thus the wheels B and BI
(Figs 1 and 3) are under the influence of the bolting or keying mechanism
arranged between them; the two following wheels (not represented) on the right
hand side and the two following wheels on the left hand side of this first pair
form in their turn, pairs which are likewise actuated by one and the same
mechanism, arranged between them.
It will thus be sufficient for me to describe one of these groups of parts, seeing
that the other groups are similar in construction and operation and only differ
in diameter.
Between the hubs of the two gear wheels the hollow shaft A is squared as at a
upon which a block or piece G is fitted, which serves as a guide and a support
for the two bolts FF. This piece turns with the shaft A. The pins or rods ff are
ocated and guided by this piece and their inner ends pass through a correspond-
ug hole in the hollow shaft and rest on one of the inclines of the bar E. The
ods ff at the other end bear against the inner face of the parts F F which
orm the crossheads of a frame FIFI (Fig. 2) capable of being radially dis-
laced and guided in this movement by the bolt holder G which is provided at
s ends with grooves gg which receive these cross heads. For the purpose of
ounting this device the sides I and I' of the frame are connected with the cross-
ads F F in a removable manner for instance by means of screw bolts.
The frame thus mounted can be displaced radially in its guide in one direction
the other according as under the action of the inclines of the bar E the rods
pins ff thrust the frame in one direction or the other.
Each wheel B or 'B' carries upon the side lying toward the bolting device, and
far from the centre as desired, a shoulder bor b by preference formed with the
eel but it may be secured thereto.
One crosshead F facing this side of the wheel has a shoulder h adapted to
e in a corresponding groove g of the bolt holder; the other crosshead F
ies upon its side which faces the other wheel B₁ a shoulder h' also adapted
hove in a groove between parts g² of the bolt holder G.
hus according to the position occupied by the frame FI FI in a radial
ction one or other of the shoulders of the bolt holder

page_text: or other of the shoulders of the. wheel and so will effect the bolting or keying
of a wheel to the hollow shaft A, the other wheel remaining loose.
It will be understood that in order to rigidly connect or key any one of the
loose wheels to its shaft A, all that is necessary is, that the operator displaces
the operating mechanism or part in such a manner, that the bar E slides in the
direction and to the extent desired, in order that under the action of the corres-
ponding bolt, the frame of that pair of wheels of which one is to be thrown into
gear, assumes the radial position which passes the corresponding shoulder to
the desired distance from the centre, so as to determine the abutment of this
shoulder against the shoulder or bush of the wheel to be actuated.
The parts of the bolt holder and the extension 2 of the transverse piece
upon the side opposite to the shoulder or h¹ are not essential for the invention,
as they only serve to ensure a better guide to strengthen the pieces.
It will be seen (Fig. 1) that the shoulders and b being at the same distance
from the centre, if it is for instance the shoulder of the left hand wheel which
is acted upon by the bolt the other shoulder will be in such a position as not
to meet the shoulder or bush of its respective wheel and vice versa.
Fig. 1 represents the device in the position in which neither wheel is engaged
or thrown into gear.
It will be seen by reference to Fig. 4, which indicates the shoulder in its
active position that according to the construction represented the crosshead F
is completely inserted in its support or bearing and that the shoulder h only
projects as far as necessary, its lower part remaining inserted beween the paris g
mentioned.
From the construction described I obtain a number of advantages not found
in former speed changing mechanisms of this kind, more especially in the case
of mounting and dismounting and the simplicity and strength of the construction.
On the other hand if the idea in general to employ a central or axial mechanism
for actuating the radial bolts is not novel, it is not less true that the former
devices based upon this principle did not present the solidity and reliability of
my device, and this especially owing to the fact that the mechanism for throw-
ing the wheel into gear attacks in these former devices the wheel so near the
centre that the power is applied at so short a leverage that injury to the apparatus
may be always apprehended, whereas in the case of my device I increase the
leverage as far as I like within the limits allowed by the diameter of the wheel.
Another advantage which however is not found in the modifications which I
shall refer to further, consists in the omission of any springs.
In the device described when the frame F I F¹ I¹ occupies its central position
it is not operated on by the centrifugal force, or rather the two diametrically
opposite halves of the frame being perfectly equipoised, the effect of centrifugal
force developed by the rotation of the frame around its axis, balance each other.
When the frame is driven outwardly on one side by the effect of the displacement
of the bar E, the two resultants of the centrifugal force no longer equipoise each
other, but the general resultant is annihilated by the bar E which receives the
thrust from the rod or pin which lies nearest to the centre. The effort to be
overcome in order to return the frame is very small being equal only to the
ifference between the two directly opposite resultants which difference can never
reach a high maximum by reason of the construction of the apparatus.
In another form of my invention where springs are employed as shewn in
Figs. 5 and 6 the bolt holder G is formed as a circular disc mounted on a square
or otherwise keyed on the hollow shaft A between the two loose wheels B and B
of one pair as previously described.
This disc G serves as a guide for the radial bolts f f¹ actuated by the inclined
planes or cams of the bar E.
The bolts act directly upon the shoulders of the wheels to be thrown into
gear and carry for this purpose shoulders or which are adapted to move
in guide grooves of the disc G. To facilitate the construction, the bearings for

page_text: ports and then shoulders are bored and sunk radially into the disc the latter
is then surrounded by a ring K.
As the bolts ff' thus are independent of one another the centrifugal force
would permanently tend to drive them out when the device is turning, it is
therefore necessary to oppose to it a force which has a tendency to return the
bolt toward the centre in such a manner that the same is under the influence
of the inclined plane or cam of the bar E which is capable of driving it toward
the periphery while it will automatically return under the action of the said force
in spite of the centrifugal force. For this purpose the bolts ƒ ƒ are made hollow
and contain a spring which receives its support at one end either directly or in-
directly through a plug acting against the inner face of the ring above referred
to and the other end of which exerts a pressure greater than that of the centri-
fugal force against the bottom of the bolt and thus tends to constantly drive the
same toward the centre.
In Figs. 5 and 6 I have shewn two diametrically opposite bolts for the left
hand wheel (instead of one as in the other case) and two other diametrically
opposite bolts but set at 90 degrees to the former for the right hand wheel.
In Figure 5 the bolts of the left hand wheel are supposed to be thrown into
gear by their shoulders with the shoulders on the wheel which they thus key to
the shaft A whilst the right hand wheel remains loose. On pushing the bar E
toward the right the inclined planes et will drive the bolts ff toward the
exterior and throw the shoulders out of engagement with the shoulders
of the wheel ] which thus becomes again loose, but at the same time
the cams e placed on the bar E at approximately right angles to
the cams e will enable their corresponding bolts which are approxi-
mately at right angles to the first mentioned to return toward the centre under
the action of their springs whereby they will be thrown into gear for the opposite
wheel B.
With this modification all that is necessary to change the speed from the
maximum to the minimum is to slide the bar in the proper direction for succes-
sively passing the different pins over the inclined planes or cams so as to gradually
pass from the higher to the lower speed and that a single arrangement of inclined.
planes or cams is thus sufficient providing that the displacement of the longitu-
dinal bar be sufficiently great.
It will also be noticed that with this device it is impossible that two wheels,
that is to say more than one, be simultaneously thrown into gear or keyed to
their shaft.
The device of Fig. 6 does not differ essentially from that shewn in Fig. 5,
except that the spiral springs may be replaced by curved leaf springs pl p² pr3 -
having a tendency to drive the bolts toward the centre.
It is evident that in all cases the bar E must turn with the shaft containing
the same. The operating mechanism therefore must be so connected with this bar
as not to impede this movement.
As stated I do not desire to claim in general a speed changing device with its
gearing parts or wheels in permanent gear nor the method of actuating such
peed changing device by an axial bar adapted to be displaced longitudinally in
hollow shaft nor even the use of radial bolts for keying a loose wheel to its shaft.
Having now particularly described and ascertained the nature of my said
nvention and in what manner the same is to be performed I declare that what
claim is:-
1. In a speed changing gear of the class in which the parts or wheels are in
ermanent gear and in which the engagement is effected by means of radial bolts
ctuated by a central bar, the arrangement of wheels grouped in pairs, the two
heels of each pair being controlled by the bolts of a single bolt holder placed
etween them, substantially as described.

page_text: 2. In a speed changing gear the arrangement with the hollow shaft, of a
central rod or bar having the cams or inclined planes, the bolts acted on by same
and the loose gear wheels with shoulder pieces, substantially as and for the
purpose described.
3. In a speed arranging gear, the arrangement of the bolt holder and of the
bolts, substantially as described with reference to Figs. 1, 2, 3 and 4 of the
accompanying drawing.
4. In a speed changing gear, the arrangement of the central rod or bar, of the
bolt holder and of the bolts, substantially as described with reference to Fig. 5
of the accompanying drawing.
5. In a speed changing gear, the arrangement of the bolt holder and bolts
substantially as described with reference to Fig. 6 of the accompanying drawing.
6. The complete speed changing gears constructed substantially as described
and illustrated in the accompanying drawing.
41 0011
T
1000
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, W.C.,
Chartered Patent Agent,
For the Applicant.