Improvements in Stopping and Starting Appliances for Tram-cars and other similar Vehicles.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Stopping and Starting Appliances for Tram-cars
and other similar Vehicles.
I, EDMUND CHADWICK, of 1, Falcon Street, Douglas, Isle of Man, Retired
Builder, do hereby declare the nature of this invention to be as follows:-
This invention has for its object a stopping and starting appliance for tramcars
and other similar vehicles, and is designed mainly to very greatly lighten and
simplify the apparatus and enable the entire mechanism to be worked from one
gearing axle instead of from two as formerly.
The following is a description of my experimental machine:-
The axle behind or in front of the tramcar has on it two spur wheels. One
of these is fast, and close to it is the other spur wheel, which rides loose on the
axle. Means are provided when starting the car for locking the loose spur wheel
into the fast spur wheel so that the loose spur wheel shall drive the axle when so
required. To this end I provide the fast spur wheel with a concentric recess or
chamber and inside this concentric recess I locate a friction ring, capable in its
normal position of riding loose in the recess but when expanded of gripping the
interior of the same so as to interlock with the spur wheel and revolve therewith.
Inside the same recess, I also provide a wedge shaped device capable when forced
into the split between the opposite and adjacent ends of the friction ring to expand
said ring and lock it firmly in the recess. The spur wheel which rides loose on
the axle is formed with means for forcing this wedge into the split so as to lock
the ring, or liberate the wedge so as to unlock the ring, these means preferably con-
sisting of forming the loose spur wheel with a sleeve of suitable length on which
is formed a square or flat which is adapted to abut against an abutment or shoulder
on the wedge.
A
On a subsidiary shaft I place also two toothed wheels, one of these keyed to the
said shaft and the other riding loose on it. This latter gears with the spur
wheel, which is keyed to the axle of the vehicle. Riding on this subsidiary shaft
is a clutch and a lever so arranged that by mechanism at either end of the tramcar,
this clutch can rigidly connect the loose wheel with the subsidiary shaft.
smaller wheel or pinion keyed to the subsidiary shaft gears on a long rack bar
to which the spring compressing device is attached. Into this same rack also
gears the loose wheel on the carrying axle of the tramcar. Roller wheels or other
guides hold the rack in position, while allowing it longitudinal motion. Attached
to the framework, I form a cage in which the end of the rack or projection pin
therefrom works, and in this cage a very powerful spring is compressed between
two washers. On the rack or its continuation outside these two washers, pins
are placed, so that whichever way the rack is forced, one pin or other will pull
back the washer and thus compress the spring against the other washer and the
stationary framework.
The mode of action is as follows:-
When the car is to be stopped. the lever is pulled and the clutch in 1

page_text: gear, the fixed spur wheel on the tramcar axle turning the spur wheel on the
subsidiary shaft. This drives the smaller pinion on the subsidiary shaft and it
again drives the rack, compressing the spring, and the spring thus acts as a braking
force on the axle and stores up the energy of the axle until the strain either
skids the wheels as it will do after about 2 revolutions in my model, or stops the
carriage. The moment, however, the clutch is withdrawn, the spur wheel on the
subsidiary shaft is disconnected and the force or pressure of the compressed spring
will drive back the rack. This will rotate the spur wheel, which is loose on the
axle, forcing the wedge into the split in the friction ring, expanding it and thus
locking the two spur wheels together. The result is that the action of the spring
through the rack and spur wheels drives the axle and thus starts the carriage.
In thus describing my model, I wish it to be understood that I do not bind
myself to the exact arrangements hereinbefore described, as it is obvious that
various parts could be considerably altered without departing from the principle
of my invention. Thus for example instead of the rack bar and spring com-
pression device set forth, I may gear the small pinion on the subsidiary shaft to
the loose wheel on the carrying axle by means of an endless chain, and on the
subsidiary shaft I place a drum having one end of a chain or rope attached fast
thereto. The other end of this chain or rope after passing through the compressing
spring in the cage is attached to a washer in such a manner that when the drum
revolves one way it will wind up the chain or rope, and compress the spring
and thus store up the power for starting the car. Furthermore I may provide an
arrangement for absolutely ensuring the two spur wheels, namely the fast and the
loose one, interlocking together when the energy stored up in the spring is
released. This arrangement may consist of any convenient means, whereby the
movement of the split ring is not rendered so free as that of the loose spur wheel.
This may be effected by friction or by inserting between the two wheels a disc
pinned or otherwise coupled to the split ring located in the recess of the fast
spur wheel. This disc may be provided with ratchet teeth engaged by a pawl
in such a manner that immediately the clutch is withdrawn, the pawl will tem-
porarily engage these ratchet teeth and thus prevent the split ring from freely
revolving. This ensures the loose spur wheel forcing the wedge into the split
in the ring and expanding it, thus locking the two spur wheels together on
the axle.
1
1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in Stopping and Starting Appliances for Tram-cars
and other similar Vehicles.
I, EDMUND CHADWICK, of 1, Falcon Street, Douglas, Isle of Man, Retired
Builder, 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 has for its object a stopping and starting appliance for tramcars
and other similar vehicles, and is designed mainly to very greatly lighten and
simplify the apparatus and enable the entire mechanism to be worked from one
gearing axle instead of from two as formerly.

page_text: -
The invention will be understood from the following description, reference
being had to the accompanying drawings, in which:
Figure 1 is a front elevation of my appliance;
Figure 2 a plan thereof;
Figure 3 a face view of the concentric recess or chamber in the spur wheel B,
with friction ring and wedge shaped device for expanding said ring and locking
it in the recess;
Figure 4 a vertical section through the chain wheel and drum, which ride loose
on the axle, but are capable of being locked to the spur wheel B by the wedge
shaped device E and abutment F;
Figure 5 an elevation of the chain wheel with sliding wedge shaped piece E
removed, but showing the abutment F'.
Referring to these figures--
A is the axle which works the entire mechanism and may be the axle at the rear
or that at front of the tramcar. It has on it a spur wheel B and a chain wheel C.
One of these namely B is fast, and close to it, is the chain wheel C, which rides
loose on the axle A. Means are provided when starting the car for locking the
loose chain wheel C into the fast spur wheel B so that the loose chain wheel C shall
drive the axle A when so required. To this end I provide the fast spur wheel B
with a concentric recess or chamber B₁ and inside this concentric recess locate
a friction ring D, capable in its normal position of riding loose in the recess but
when expanded of gripping the interior of the same so as to interlock with the spur
wheel B and revolve therewith. Inside the same recess, I also provide a wedge
shaped device E capable when forced into the split between the opposite and
adjacent ends of the friction ring D to expand said ring and lock it firmly in the
recess B¹. The chain wheel C which rides loose on the axle A is formed with
means for forcing this wedge into the split so as to lock the ring, or liberate the
wedge so as to unlock the ring, these means preferably consisting of forming
the loose chain wheel C with a square or flat abutment F which is adapted to abut
against the shoulder e on the wedge E.
On a subsidiary shaft GI place also two toothed wheels, one of these a chain
wheel H keyed to the said shaft, and the other I riding loose on it, and gearing
with the spur wheel B, which is keyed to the axle A of the vehicle. Riding on
this subsidiary shaft G is a clutch and a lever K pivotted at k so arranged that
by mechanism at either end of the tramcar, this clutch can rigidly connect the
loose wheel I with the subsidiary shaft G. The chain wheel or pinion H keyed
to the subsidiary shaft G is geared by the chain L to the chain wheel C which
rides loose on the carrying axle A of the tramcar. On this chain wheel C there
is formed a sleeve C¹ and on the sleeve is mounted or formed a winding drum 0
having one end of a chain or rope P attached fast thereto. Attached to the frame-
work, I form a cage and in this cage a very powerful spring N is capable of being
compressed. The other end of the chain or rope P after passing through the
compressing spring N is attached to a washer Q in such a manner that when the
drum O revolves it will wind up the chain or rope and compress the spring, and
thus store up the power for starting the car. R is a disc forming a cover for
enclosing the recess or chamber B in which latter are located the devices E and F,
S bearers by which one end of the framework T rests, U split collars on axle A
to keep that side of frame in place, V bearings on the framework T in which the
auxiliary shaft G revolves. It will be seen that inside one of these bearings V
the clutch mechanism J works, a slot W being provided in the bearing to allow
free movement of the lever K to operate said clutch.
The mode of action is as follows:-
When the car is to be stopped, the lever K is pulled and the clutch is brought
into gear into the position shown in Figure 2, the fixed spur wheel B on the tram-
car axle turning the spur wheel I on the subsidiary shaft G. This drives the
smaller chain pinion on the subsidiary shaft G and it again drives the chain
wheel C rotating the drum O and compressing the spring, and the spring thus acts

page_text: as a braking force on the axle A and stores up the energy of the axle A until
the strain either skids the wheels as it will do after about 2 revolutions, or stops
the carriage. The moment, however, the clutch J is withdrawn, the spur wheel I
on the subsidiary shaft G is disconnected, and the force or pressure of the
compressed spring N will rotate back the drum O. This will rotate the chain
wheel C, which is loose on the axle A, forcing the wedge E into the split in the
friction ring D, expanding it and thus locking the two wheels B and C together.
The result is that the action of the spring N through the drum O and wheels C.
and B drives the axle A and thus starts the carriage.
In thus describing my invention I wish it to be understood that I do not confine
myself to the exact arrangement herein before described, as it is obvious that various
parts can be considerably altered without departing from the principle of my
invention, thus for example, instead of gearing the pinion H on the subsidiary
shaft to the loose wheel C on the carrying axle, by means of the endless chain L,
I may key to the subsidiary shaft G a toothed wheel which gears on a long rack
bar to which the spring compressing device is attached. Into this same rack also
gears a loose wheel on the carrying axle of the tramcar. Roller wheels or other
guides hold the rack in position while allowing it longitudinal motion. Attached
to the framework I form a cage in which the end of the rack or projection pin
therefrom works, and in this cage the spring is capable of being compressed between
two washers. On the rack or its continuation, outside these two washers, pins are
placed, so that whichever way the rack is forced, one pin or the other will pull
back the washer, and thus compress the spring against the other washer of the
stationary framework. In this manner therefore the moment the clutch J is
withdrawn, and the spur wheel on the subsidiary shaft thereby disconnected, the
force or pressure of the compressed spring, will drive back the rack, thus rotating
the spur wheel which is loose on the axle, and forcing the wedge into the split
in the friction ring, expanding it and thus locking the two spur wheels together.
The result is that by this arrangement, the action of the spring through the rack
and spur wheels drives the axle and thus starts the carriage.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The improvement in stopping and starting tramcars or other vehicles, which
consists in attaching to a framework, a cage containing a spring capable of being
compressed, and in mounting fast on the axle a spur wheel, and loose on the same
axle, a winding drum or wheel having a chain or cord or a rack or other device
capable of compressing the spring, in combination with a mechanism so arranged
that when the vehicle is to be stopped, it will cause the fast spur wheel on the
axle to drive the drum or wheel which is loose on the axle in the reverse direction
to the axle, and compress the spring which thus acts as a braking force on the
axle and stores up the energy of the axle until the vehicle stops, and a second
mechanism so arranged that the moment the first mechanism is disconnected, the
force or pressure of the compressed spring will rotate back the drum or wheel
and automatically lock the drum or wheel and the spur wheel together, thus
driving the axle and starting the carriage, substantially as described.
2. In apparatus of the kind characterized by Claim 1 for stopping and starting
tramcars and other like vehicles, the mechanism for locking the winding drum
or wheel that is loose on the axle with the spur wheel that is fast thereon so that
the loose drum or wheel shall drive the axle when required, which consists in
forming or providing the spur wheel with a concentric recess or chamber and inside
this recess locating a friction ring capable in its normal position of riding loose
in the recess, and in forming on or in connection with the drum or wheel a square
or flat abutment, in combination with a wedge shaped device so arranged that when
the force or pressure of the compressed spring rotates back the drum or wheel
the square or flat abutment on the drum or wheel coming against a square or

page_text: flat shoulder on the wedge shaped piece, will force the latter into a split between
the opposite and adjacent ends of the ring, expanding it, thus interlocking the
drum or wheels and the spur wheel together, substantially as described.
3. Also the mechanism for driving the drum or wheel that is loose on the axle
from the spur wheel that is fast on the axle, but in a reverse direction thereto, so
that in stopping the car the spring shall be compressed and thus store up power
for restarting the car, which consists in providing in combination with the axle a
subsidiary shaft having a wheel fast on the shaft adapted by means of a chain, rack
or otherwise to drive the winding drum or wheel in a reverse direction to the
axle, and a toothed wheel loose riding upon said subsidiary shaft and gearing with
the fast spur on the axle, in combination with a clutch and lever device so
arranged that by mechanism at either end of the vehicle this clutch can rigidly
connect or disconnect the loose wheel on the subsidiary shaft, substantially as
described.
4. The general arrangement, construction and combination of parts forming my
improved apparatus for stopping and starting tramcars and other vehicles sub-
stantially as set forth.
ted this 1st day of December 1897.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.