Improvements in Brakes for Velocipedes, Motor Oars, and other similar Vehicles.
Year: 1897

page_text: Date of Application, 5th Jan., 1897-Accepted, 10th Apr., 1897
COMPLETE SPECIFICATION.
Improvements in Brakes for Velocipedes, Motor Oars, and other
similar Vehicles.
I, WILLIAM AUGUSTUS LEGGO Junior, of 177 Times Building, New York,
United States of America, 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 :-
The object of this invention is to produce a brake for bicycles and other vehicles
that will be automatic in its action to the extent that whenever a restraining or..
back-pedalling effort of sufficient force, is exerted by the rider, the brake will take.
effect. A further object of this invention is to produce a brake of this character
that will be simple, strong, readily and 'cheaply made, and further, one in which
the mechanism is concealed, thereby insuring protection from dirt and giving no.
evidence of its presence to the eye. The features necessary to carry out the
principle of my invention may be applied to or upon any axle of a vehicle. In the
detailed description which follows, reference is made particularly to a bicycle, but.
it is to be understood that the invention is applicable to horseless carriages and any
other form of vehicle where its presence would be desirable.
In the accompanying drawings
Fig. 1 is a section through the crank hanger of a bicycle showing, the parts of
my brake applied thereto and in section:
Fig. 2 is a side view of parts of a crank and sprocket-wheel :
Fig. 3 is a side view of the brake strap:
Fig. 4 is a sectional view of the rear hub of a bicycle, shewing the brake:
mechanism applied thereto :
Fig. 5 is a side view of the rear hub and a portion of the bicycle frame. .
Referring to the drawing by letter, a is the crank axle of a bicycle provided at
its extremities, as usual, with the cranks a¹, a'. Rigidly upon the axle and to one.
side of its centre is placed an externally threaded collar a having a rather steep
and heavy thread. This collar may be formed integrally with the shaft if desired.
b is a loose sleeve upon the axle, covering the longer section thereof on one. side
of the collar. At its outer end it has formed upon it or otherwise rigidly fixed.
to it, the sprocket wheel b', over which the driving chain passes. The hub of
the sprocket wheel is provided with a laterally projecting lug and the inner side..
of the crank adjacent to the sprocket is provided with a corresponding lug a³ and
the power exerted by the rider. in propelling the machine is transmitted through
these two lugs, which form a kind of jaw clutch between the axle and the sprocket
wheel. Upon the sleeve b is rigidly placed an abutment ring c and facing this is a
moving member c' of a friction ciutch. This member c¹ consists of a sleeve having
an internal thread formed at one end that is in engagement with the collar a² on
the axle, and a friction face c². It is keyed upon the sleeve 6 so as to slide longi-
tudinally thereon, and to rotate therewith. Between the opposing faces of the.
abutment ring. c, and the laterally movable member is placed the web d¹ of the
drum d: the drum stands perfectly free in this position except that it is surrounded. .
by a metallic strap e, the ends of which approach each other as shown in Fig. 3
and project through an opening f in the crank hanger, where they are joined
together by an adjustable bolt through which the tension of the strap upon the
drum may be regulated. The strap is prevented from rotating.by interlocking

page_text: with the hole in the crank hanger through which it passes. The drum being
otherwise free except for the pressure of the strap upon it, will rotate whenever
the grip of the parts c and c' upon it overcomes the friction between the drum and
the strap. The cone for the ball bearing at the sprocket end of the hanger will
be placed upon the sleeve b, the ball cup g' being screwed into the hanger in the
usual manner.
The cone q at the other end is screwed on to the axle while the
cup g' is screwed on to the hanger. The dust caps v close the ends of the hanger.
A rubber or other spring washer g.is inserted between the edge of the drum and
the bearing, to form a cushion for easing the movement of the drum towards the
fixed ring c, and to normally hold the drum squarely in place against the pins g.
While the bicycle is being propelled forward, the lugs a³ and 62 are together
and the parts a a, b c and c¹ all rotate together in the same direction. To apply
the brake, the rider puts back pressure upon the pedals which immediately separates
the lugs a3 and 6, the inertia of the vehicle carrying lug ahead. This
differential movement between the screwed collar a² and the movable member c¹ of
the clutch, causes the latter to slide in a lateral direction. along the axle and to
force the drum d'over towards the fixed ring e and to clamp the web of the drum
between the opposing faces of the parts c and c'. This creates friction, inasmuch as
the drum is held by the strap e, and consequently braking force is applied to the
wheel. This may be increased by increasing the back-pressure upon the pedals.
Finally, this back-pressure overcomes the friction between the drum and the strap
and the drum moves with the parts c and c¹. The wheel is now retarded by the
heavy friction between the strap and the drum, which is predetermined by the
adjustment of the tension of the strap. If now the wheel is not being sufficiently
retarded, the rider may continue to back-pedal and thus add his strength to the
constant friction of the brake. At any moment in the operation of applying the
brake, the rider may remove his feet from the pedals and the brake will continue
in action with constant friction, because owing to the pitch of the thread on the
collar a², (which may be calculated with this end in view) there is no force at work
sufficient to create the necessary differential movement between the collar and
the part to carry the latter out of engagement with the web of the drum.
The function of the spring washer'g is to prevent a too sudden gripping of the
web of the drum: the washer slightly resists the movement of the drum towards the
fixed ring it also holds the drum out of contact with the ring c while the brake is
off. Referring now to Figures 4 and 5 illustrating the necessary modification of the
invention to apply it to the rear hub of a bicycle, we find substantially the same parts
operated in substantially the same manner. i represents the sprocket wheel fixed
directly upon the main hub i corresponding to the axle a. Surrounding the main hub
is a second hub j which carries the spokes of the wheel, the flanges j¹ being provided
for this purpose. Between the main hub and the outer hub is a screw threaded
connection shown at k which performs the same function as the collar a² in Fig. 1.
Between the sprocket wheel and the outer hub 7 is an interlocking connection
consisting of lugs of the same character as a³ and 62. On the one end of the
main hub is fixed a friction ring m corresponding to the ring c. This faces up a
friction surface n on the outer hub j, and between these two faces the web of the
drum d is clamped. The drum is of the same construction as that shewn in Fig. 1
and is also surrounded by a strap e of the same character. The ends of the strap
are however, conveniently secured to the lower horizontal brace of the wheel
frame as shewn in Fig. 5, one of the securing bolts .o being used to adjust the
tension of the strap upon the drum. A cushioning washer p may be inserted
between the drum and the frame to correspond with the washer g. This modified
form of the brake is operated in exactly the same manuer as the first form
described. Back-pressure upon the pedals separates the lugs and causes
differential rotation of the inner and outer hubs. This moves the outer hub
laterally and clamps the web of the drum between the friction surfaces ou the
parts m and j. When the friction here overcomes that between the drum and
its strap, the drum commences to rotate and increases the retarding power. The
:

page_text: lateral movement of the outer hub being only a small fraction or au much, does not
in any way affect the running of the wheel which is carried by the hub, nor
does the running of the wheel affect the operation of the brake. It is calculated.
that a separation of lugs l, or a³ and 6 of 90 degrees will be sufficient to bring
the friction surfaces together. I have placed a set screws in the outer hub to.
bear upon the inner hub to prevent too sudden or rapid relativement movement of
the two hubs.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. In a cycle, two rotating elements connected together by a
screw thread
whereby their relative movement will cause oue of them to move laterally, in
combination with two brake elements one of them being carried by one of the said
rotating elements, and a third brake element interposed between the said two brake
elements, whereby the relative lateral movement of the said rotating elements will
cause the said third brake to be clamped between the other two brake surfaces,
substantially as hereinbefore described.
2. In a cycle brake, an axle and a pair of cranks both of which are rigidly
secured thereto and through which the propelling power is transmitted, a sliding
brake member normally rotating therewith, means whereby the axle and the brake-
member may be caused to rotate differentially, and a screw thread connection
between the axle and sliding member whereby such differential motion will cause
the sliding member to move longitudinally upon the axle, substantially as herein-.
before described.
3. In a bicycle, the combination of the crank axle and cranks, a sprocket wheel
loosely mounted on the axle, interlocking abutments whereby the cranks and wheel
will rotate together or differentially, at will, and a fixed screw thread on the axle,.
a brake member engaging with the said thread and adapted to rotate with the
sprocket wheel, but to move independently thereof to operate a brake, substantially
as herein before described.
4. In a bicycle the combination of a crank axle and cranks, a sprocket wheel
loosely mounted on the axle, interlocking abutments whereby the cranks and wheel
will rotate together or differentially, at will, and a fixed screw thread on the axle,.
a brake member engaging with the said thread and adapted to rotate with the
sprocket wheel, but to move independently thereof to operate a brake, a drum.
and fixed strap surrounding the same for producing a constant friction the said.
brake member being arranged to engage with the drum to cause it to rotate with.
the sprocket wheel and against the friction of the strap thereon, substantially as.
described.
5. In a cycle, the combination of an axle, a sleeve thereon carrying a sprocket
wheel, a brake member feathered to the sleeve and provided with a screw thread,.
a corresponding thread on the axle and means for rotating the axle independently
of the sleeve to a limited extent for the purpose of moving the brake member,.
substantially as described.
6. In a cycle brake, the combination of an axle, a sleeve surrounding it and
normally rotating therewith and a sliding brake member feathered to the sleeve,.
a corresponding brake member, means whereby the axle and the sleeve may be.
caused to rotate differentially to a limited extent, and a screw thread connection.
between the axle and the sliding brake member whereby such differential motion.
will cause the sliding brake member to move longitudinally upon the axle towards.
or away from its corresponding member, substantially as described.
7. A brake for vehicles consisting of a wheel hub to which the driving power is.
applied, an auxiliary hub to which the spokes of the wheel are attached, a frictional
surface carried by each hub, corresponding frictional surfaces against which the
former surfaces are adapted to bear, in combination with means for creating
relative lateral movement of the two hubs whereby the said corresponding friction

page_text: surfaces are caused to moves towards or away, from each other, substantially as
described: <
2
8. A brake for vehicles consisting of a wheel hub to which the driving,power is
applied, an auxiliary hub to which the spokes of the wheel are attached, a friction,
flange carried by each. hub, an element located between the said flanges, and
adapted to be clamped thereby to create friction, in combination with means for.
creating relative lateral movement of the two hubs whereby the said flanges.nay
be caused to clamp.or release the, said intervening element substantially as and for
the purpose set forth.
9. A brake for vehicles consisting of a wheel hub to which the driving power is
applied, an auxiliary hub to which the spokes of the wheel are attached, a friction
flange carried by each hub, a drum located, between, the said friction flange and
adapted to be clamped. or released. thereby, a friction, strap upon the drum, the
tension of which retards the. rotation of the drum, in combination with means
for creating relative lateral movement of the two hubs whereby the drum may be
clamped or released by the flauges, substantially as described.
10. In a cycle brake, the combination of a hub carrying a sprocket or other gear
wheel for transmitting propelling power thereto, an auxiliary hub surrounding the
first hub to which the spokes of the wheel are attached, interlocking lugs, between
the main and auxiliary hubs, whereby one is driven by the other, a screw threaded
connection between the two hubs whereby differential rotation of them will create
relative lateral movement, a brake drum surrounded by a brake strap, a flange or
web carried by the said drum, and a flange upon each of the said hubs between
which that on the drum is clamped when the two hubs move laterally with respect
to each other, substantially as described.
Dated this 4th day of 1907
W. E. HEYS & SON,
Agents for the Applicant.