Year: 1886

page_text: Date of Application, 13th Nov., 1886.
Complete Left, 15th Aug., 1887.
Complete Accepted, 20th Sept., 1887.
I ALFRED FOSTER of Boxmoor Saw Mills, Hemel Hempstead in the County of
Herts, Timbor Merchant and Manufacturer do hereby declare the nature of this
invention to be as follows :-
This invention relates to novel arrangements of mechanism for utilizing tho impetus
of running carriages (especially tramcars), for stopping the same, when required, und
creating a store of power for assisting in the starting of the same.
For this purpose I use a vacuum cylinder and piston, as heretofore proposed for the
like purpose, but I employ, in connection therewith, a novel arrangement of mechanism
for attaining the desired results above indicated.
According to my invention, I fit my cylinder with a piston rod, which passes through
one or both ends of that cylinder, a stuffing box or stuffing boxes, as the case may be,
being provided to make the cylinder air tight.
Supposing the cylinder to be closed at the outer end, and to have a stuffing box at
the inner end for the passage of the piston rod, I connect this rod directly to a chain,
or its equivalent, which passes over one of a pair of chain wheels I, II, fitted loosely
on the more distant travelling wheel axle. Sliding on feathers formed on this axle is
a pair of right and left handed clutches, which are situated outside the chain wheels,
and capable, when shifted, of locking their respective wheels to their axle. These
clutches will in general be put into action alternately but occasionally both will be in
action at the same time for the purpose hereinafter mentioned. The chain, after
passing over the chain wheel I, as explained, will be led back to a chain wheel III,
loose on the travelling wheel axle near to the cylinder. This axle is fitted, like the
other, with a pair of chain wheels III and IV, and also lockng clutches, which clutches
are set in operation simultaneously with their corresponding clutches on the other
travelling wheel axle. The chain from the chain wheel III passes forward to the chain
wheel II on the more distant axle, and thence back to the chain wheel IV, whence it
passes rearwards, and is attached to the piston rod.

page_text: The inner end of the cylinder is fitted with an automatic double seated air valve for
admitting air in front of the piston, and this valve I bring under the control of the
driver, to allow for the discharge of the air drawn in by the descent of the piston.
The construction of the valve may be modified, and its action varied, to suit require-
ments for the escape and admission of air both in the forward and backward stroke of
the piston. Supposing the tramcar to be in motion, the driver, when he wishes to
retard the progress of the car, will lock the chain wheels, say I and IV, to their
respective axles. The result of this movement of the clutches will be to cause the
chain to pull forward the piston and produce a vacuum behind it. This will put a
strain upon the rotating axles to which the travelling wheels are keyed, and thus
effectually retard the progress of the car. Under ordinary circumstances, the air
admitted to the cylinder above the piston will have a free exit, as the piston is drawn
forward, the driver having a control of the valve for that purpose. When, however, a
greater power of retardation is required, the imprisoned air will be subjected to
compression by the advancing piston, and a proportionately increased drag on the chain
will be the consequence.
For the purpose of locking the brake gear as the car is brought to a stand-still, the
clutches of the wheels II and III are thrown into action, and thus the vacuum behind
the piston will be maintained, and also the compressed air in front of the piston. When
it is required to start the car on its renewed journey, it will only be necessary to
release the wheels I and IV, when the piston will, under the pressure of the air in front
of it, pull upon the chain, and impart rotary motion to the axles of the travelling
wheels in the direction to propel the car forward.
When employing a double acting piston, the rod of which passes through the
opposite ends of the cylinder, I fit the cylinder between the travelling wheel axles,
and connect the two ends of the chain to the opposite ends of the piston rod, traversing
the chain over and under chain wheels substantially in the manner above described.
The chain wheels are locked to their axles by clutches operated as before mentioned,
but the cylinder is fitted at both ends with an automatic valve under the control of the
driver. Thus, a vacuum, or compressed air, may be obtained at either end of the
cylinder at pleasure, the drag on the chain being used either to retard the motion of
the car, or to start it into motion.
Dated this 13th day of November 1886.

page_text: 1, ALFRED FOSTER, of Boxmoor Saw Mills, Homel Hempstead, in the County of
Herts, Timber Merchant and Manufacturer, 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 :-
and
My invention relates to improved apparatus for utilizing the impetus of tramway
other vehicles, for stopping the same when required, and for storing power for assisting
in the starting of such vehicles.
According to my said invention I make use of a cylinder closed at ono ond and at
the other end provided with means whereby it may be placed in communication with
the atmosphere, the said cylinder containing a piston which is connected with novel
clutch mechanism on the axles of the vehicles so that when the said clutch mechanism
is thrown into gear the piston will be drawn forward, a vacuum being produced on
one side thereof and, if desired, the air compressed on the other side, which vacuum
and compression serve to retard the motion of the vehicle while the said vacuum and
compression (if used), in returning the piston to its normal position, assist in starting
the vehicle.
In the accompanying drawings
Figure 1 is a plan of the main frame and driving wheels of a tramway vehicle
having my improvements applied thereto.
Figure 2 is a diagrammatic perspective view illustrating the connection between the
piston and the clutch mechanism on the travelling axles.
Figure 3 is a view similar to figure 1 but illustrating a modification of my
invention.
Similar letters of reference indicate similar parts throughout the drawings.
Referring to figures 1 and 2 a, is the cylinder which is closed at its outer end and b,
a stuffing box through which the piston rod c, passes at the inner or opposite end of
the cylinder a.
d, is a chain to which the piston rod c, is connected and which passes thence
horizontally to and over a chain wheel e, of the pair of chain wheels e, e' which is
carried loosely upon the road or travelling wheel axle f.
9,9', are two chain wheels which are carried loosely upon the road or travelling
wheel axle. The chain d,passes in a diagonal line from the underside of the wheel e,
to and over the wheel g¹, from the underside of which the said chain passes
horizontally forward to the underside of the wheel e'. From the upper side of the wheel e',
the chain passes diagonally to the underside of the wheel 9, the two ends of the

page_text: said chain being joined together and secured to the piston rod c, all as shewn clearly
at figure 2.
h, h, is a pair of clutches sliding on the feathers i, i, and having right and left
handed teeth adapted to engage with clutch faces j,j, formed on the outer sides of the
chain wheels e, e¹, respectively.
k, k', is another pair of clutches similarly mounted on the axle f, and capable
of engagement with the clutch faces I, 1, formed on the wheels or pulloys 9, 9',
respectively.
m, m², are bars which engage with annular grooves formed in the sliding
clutches h, h, k and k¹; and n, n', are radius bars the outer ends of which are
pivotted upon fixed brackets o, o, and the inner ends of which are coupled to the
bars m, m.
The necessary motion to be imparted to the radius bars n, n, for the simultaneous
operation of the clutches h and k, from either end of the apparatus may advantageously
be transmitted through the hand lovers p, p, one of which is coupled by the link g,
directly to one of the said radius bars n, n, while the other is coupled thereto at the
opposite end of the apparatus through connecting rods r, r, and the centrally pivotted
lever s.
The bar m', for simultaneously operating the clutches h, and , may be
advantageously operated at one end of the apparatus by a hand lever p', and link q',
similar to that hereinbefore mentioned and from the opposite end of the apparatus by
means of another such hand lever p', and connecting rods r, r, and the centrally pivotted]
lever s'.
t, represents a double seated valve which is connected to the inner ond of the
cylinder a, and which is operated through a bell-crank lever 7, and rod 23, which at one
end of the apparatus is coupled directly to a hand lever w, and at the opposite end of
the apparatus is coupled to a similar hand lever to, through a centrally pivotted lever x,
and link y.
2, represents a small air pump which may advantageously be secured to the outer
end of the cylinder to provide for the drawing off of any air which may have leaked
into the cylindor.
The operation of my improved apparatus is as follows, that is to say-Should it be
desired to apply the brake when the tramway or other carriage fitted with my
improvements is travelling in the direction indicated by the arrows figure 1, the
driver pulls the lever p, at the front end of the vehicles inwards and thus operates the
radius bars n, so that the clutches h and k, are caused to engage with the clutch teeth j.
and l, which, with the chain wheels e and g, are thus caused to rotate with the axles f
and. By these means the piston rod c, (which is above the level of the periphery
of the wheel g, as shewn in figure 2) is drawn outwards, a vacuum being formed on the
one side of the piston and the air compressing on the other side. The backward pull
applied to the axles owing to the formation of the vacuum and the compression of the
air in the cylindor causes the vehicle to come to a standstill. The stoppage can be
offected more or less slowly by more or less opening the valve t, by means of the
lover w, so as to allow the air to escape more or less rapidly as desired. At the
instant the vehicle is at a standstill the driver draws the lever p', inwards and thus
causes the clutches h¹ and k¹ to engage with the clutch faces, and ", respectively so
that the whole apparatus is completely locked, the vacuum and the air pressure (if any)
being meanwhile maintained for the purpose of re-starting the vehicle. When it is
desired to start, the hand lever p, is pushed outwards into its normal position
so that the clutches h and k, aro removed out of contact with the teeth j, l. The
piston is then free to be drawn by the vacuum and forced by the compressed air back:
into the cylinder. Thus through the clutches ' and ', the axles f, f, and the road or
travelling wheels are rotated in the direction necessary to move the vehicle in the
direction indicated by the arrows, the clutches h' and k³, remaining in their engaged
position until the axles fand f₁, under the influence of the horses or other motive
power, are caused to rotato quicker than the said clutches these being thrown out of
engagement by any such excess of speed in consequence of the inclined surfaces of
their teeth.

page_text: When the vehicle is travelling in a direction the reverse of that indicated by the
arrows the lever p, is drawn inwards, first to apply the brake and the lever p, is after-
wards drawn inwards to lock the apparatus. The lever p', may then be pushed outwards
in order to re-start the vehicle and the lever p, afterwards automatically assumes its
normal position in a manner similar to that hereinbefore described with reference to the
lever p, when travelling in the opposite direction.
It is to be observed that by suitably manipulating the valve t, through either of
the levers w, the rate at which the brake is applied or released is always under
control.
Should it be necessary to check the speed of the vehicle as when descending an
incline, and unnecessary to utilize the force of the vacuum and air pressure generated
while doing so, the lovers p, and wo, are both drawn inwards so that all the air is
allowed to escape from the front of the piston during its forward motion and as soon
as the piston has arrived at the end of its stroke the valve t, is closed and the atmno-
spheric pressure being thus cut off the piston will remain stationary when the clutches
hand, are disengaged. The piston may then be allowed to move slowly back
into its normal position by slightly releasing the valve t.
The modification of my invention represented in figure 3 is of substantially the
same construction as that hereinbefore described. In this case, however, the piston
rod extends through both ends of the cylinder which arrangement necessitates the
employment of additional chain pulleys.
In this modification is the cylinder which is supported between the road or
travelling wheel axles f,, by any suitable means. b, 6, are stuffing boxes provided
at the two ends of the cylinder a, to admit of the piston rod passing out at both ends.
From the end of the piston rod marked A, the chain d, which is connected thereto
passes to and over the guide pulley a³, from the underside of which it passes
horizontally to the underside of the chain wheel e. The chain d, is coiled once around
this chain wheel e, and leaving it at the underside passes horizontally to the underside
of the chain wheel g, around which it is coiled so that it leaves the said whool at its
upperside passing thence diagonally below the cylinder a, to the underside of the
chain wheel e'. Around this wheel, the chain is coiled so that it leaves its periphery
at its upper part to continue horizontally to the upper side of the chain wheel g, and
around the latter it is coiled once and passos to the under side of the guide pulley b²,
above which it is secured to the end marked B, of the piston rod. c², c, represent
pipes connecting the valves t, t, to the ends of the cylinder a, so that the air may be
released from either end at the option of the driver, the valves themselves closing
automatically after the release of the hand levers w, w. d², d², represent pressure
gauges for indicating the air pressure in the ends of the cylinders.
The operation of the various levers shewn at figure 3 for like results is similar to
that hereinbefore described with reference to figure 1 and therefore needs no further
description.
I wish it understood that I do not limit myself to the details of construction
hereinbefore described, as it is obvious that I may vary the same within considerable
limits without departing from the nature of my invention. For instance, instead of
employing the rods m, m³, and the radius bars n, n', for operating the cluíches I may
employ any other suitable means for the purpose.
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. In apparatus of the class herein before described the employment of a cylinder in
which a vacuum and air compression are produced simultaneously by the motion of
the piston therein, in combination with suitable clutch mechanism for permitting the
transmission of motion from the wheels to the said piston and subsequently for
permitting the return motion of the piston under the combined action of the vacuum
and the compression to act upon the wheels to start the vehicle substantially as
described.

page_text: of the
2. The combination with the cylinder a, having the piston a', and rod
clutches h, h, k, k³, the pulleys e, e', 9, 9', and the chain d, passed around the said pulleys
in such a manner that the adjacent pulleys rotate in opposite directions, substantially
as described.
3. The improved apparatus consisting of the parts constructed and combined
substantially as described with reference to figures 1 and 2 of the drawings and
operating as and for the purpose set forth.
4. The modification of my invention substantially as described with reference to
figure 3 of the drawings.