A Combined Spring and Lever Clutch and Safety Bolt for Carriages Working on Aerial Trams and in Vertical and Inclined Shafts.
Year: 1887

page_text: Date of Application, 3rd Nov., 1887
Complete Specification Left, 3rd Aug., 1888
Complete Specification Accepted, 7th Sept., 1888
"
A Combined Spring and Lever Clutch and Safety Bolt for Carriages
Working on Aerial Trams and in Vertical and Inclined Shafts.
I CHARLES MEDHURST DAVIS of Kimberley, Cape of Good Hope, House Decorator
do hereby declare the nature of the said invention for A COMBINED SPRING AND
LEVER CLUTCH AND SAFETY BOLT FOR CARRIAGES WORKING ON AERIAL TRAMS
AND IN VERTICAL AND INCLINED SHAFTS to be as follows
A perfectly certain and instantaneous Clutch by the action of which, should a
hauling-wire break, the Carriage is immediately stopped and remains stationary on
the Standing-wires, and a Safety Bolt which prevents the Carriage from leaving the
Standing-wires at any time during its ascent or descent, and when passing over the
Jumpers or supporis to the standing wires.
22
Loss of life and destruction of Miring gear, accidents and stoppage of work caused
by the breakage of hauling-wires or by the Carriage leaving the standing wires, more
especially when passing the "Jumpers," are of frequent occurrence and the present
invention is for the purpose of averting such accidents.
It must be understood that the carriage runs on two standing-wires. Double-
clutches are arranged so that they may grip each standing-wire on its opposite sides.
The double-clutches are arranged on each side of a carriage. The springs for actuating
the clutches are, preferably, spiral, and are held out of gear so long as a lever in
connection with the hauling-wire is held straight out in front (by such hauling-wire)
in the line of haulage. If the hauling wire breaks this last mentioned lever falls down
by its own weight-assisted by springs, if desired. In so doing it releases a pawl or
catch which in its turn releases the main-clutch-springs.
These latter, being connected by suitable levers and rods, cause the double-clutch
blocks, say, of indiarubber, which are acted upon by oblique levers, to securely grip
the standing-wires. Indiarubber, leather, lead, wood, or other suitable blocks may be
ased, but the wires must not be damaged. The oblique levers have their obliquity
arranged so that when brought into action they grip all the harder.

page_text: A modification may be arranged so that the loaded carriage may be used to give
out the necessary power to the gripping clutches this by arranging that the weight
of the tub and its load hang on gear connected with such clutches, with the necessary
power of falling thro' a given distance, if released.
Rods, Catches, &c., are further arranged so that, when a carriage arrives at the
bottom of the standing-wires and touches the anchorage, the hauling-wire-lever before
mentioned is prevented from falling over. This in order to meet a slackening of the
hauling-wire at such a time.
"
The Safety-bolt is arranged so that its end passes underneath its standing-wire so
that the carriage wheels and their flanges cannot jump clear away. One or more of
these bolts may be fitted on each side of a carriage. In order, however, to pass a
jumper" or "standing-wire-support" my Safety-bolt must move to one side, right or
left, to clear the support. To avoid danger at these dangerous positions arrange
another bolt or hook which stands further to one side and engages with (or passes
under) a projecting ledge arranged a little lower down on the side of the support.
By this means the jumper is passed in safety and my safety-bolt, which acts with its
own springs, returns to its former position. To free a "clutched" carriage a man
travels down the standing wires in a cradle taking with him the end of the hauling-
wire. After securing the carriage to the standing-wires with a lanyard he re-extends
the main springs (or, in the modified form, raises the tub) by screws & nuts provided
for the purpose. A temporary catch secures the springs, and the nuts are then run
back out of the way.
After this the main catch is put into position and the hauling-
wire again attached. As this wire becomes taut the lever engaging with it begins to
get back into position, first securing the main catch and afterwards releasing the
temporary one.
The invention is also applicable to Carriages working in Vertical and Inclined
Sluts.
Dated
at Kimberley, Cape of Good Hope, this ord day of October 1887.
"COI

page_text: Working on Aerial Trams and in Vertical and Inclined Shafts.
I, CHARLES MEDHURST DAVIS, of Kimberley, Cape of Good Hope, House Decorator,
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
A perfectly certain and instantaneous Clutch by the action of which, should a
hauling wire break, the carriage is immediately stopped and remains stationary on
the standing wires, and a Safety-bolt which prevents the carriage from leaving the
standing-wires at any time during its ascent or descent, and when passing over
the "Jumpers" or supports to the standing-wires.
Loss of life and destruction of mining gear, accidents and stoppage of work caused
by the breakage of hauling-wires, or by the carriage leaving the standing-wires, more
especially when passing the "Jumpers," are of frequent occurrence, and the present
invention is for the purpose of averting such accidents.
In order the better to explain my invention I have annexed two sheets of
drawings.
Fig. 1 is a Side Elevation-partly in section of a carriage standing upon, and
clutched to, its standing-wires; its hauling-wire having broken and allowed the bridle-
lever to fall downwards. A "Jumper" is also shown supporting a standing-wire.
Fig. 2 is a corresponding transverse section thro' a clutch-box. It shows also a
Safety-Bolt, and a section (broken) thro" a "Jumper."
Fig. 3 is a longitudinal Sectional Plan thro' a Clutch-box.
Fig. 4 is a plan of this last viewed from below.
Fig. 5 is a Sectional Elevation showing the mode of putting the temporary catch
and trigger into action.
Fig. 6 is a Sectional Elevation showing the gear when the carriage is in use, with
the bridle-lever hauled to the front, and the whole set ready for action in case the
hauling wire breaks.
Fig. 7 is a corresponding plan (broken) showing parts of the gear, and the trigger-
frame.
Fig. 8, Sheet 2, is a Side Elevation showing certain of the modified parts requisite.
for actuating the clutches by the weight of the tub.
And Fig. 9 is a corresponding plan showing further details of this latter
arrangement.

page_text: It must be understood that the carriage taken to exemplify my invention is an
ordinary one, and that any suitable one will do.
The class shown bas a tub slung in the centre between two side frames; it has four
wheels a pair in front and a pair behind--and these run on two parallel standing-
wires (one on each side) which form the pathway for the said wheels-all this
as usual.
Double clutch-boxes A, which may be longer or shorter as desired, are attached
to each side-frame B, and these surround the standing-wires C, ready to act on them
when released.
Force is transmitted to the clutches by strong springs D, encased in boxes, say
at D', on each side frame. The springs D pull at the screwed-rods E, attached to the
crossbar F, which latter rans across the carriage for this purpose, see fig. 7.
Attached to the cross-bar Fare levers G whose fulcra are at Gand whose lower
arms, G², span the standing-wires, one on each side of the carriage, and connect
up by the side rods H to the double clutches A', see fig. 3.
Fig. 1 shows the clutch gripping the wires C, the hauling-wire J having broken
and released the main pawl K (whose fulcrum is at K on the fixed frame, N, above)
by the fall of the bridle-lever L.
After such an occurrence a workman travels down the wires C in a cradle taking
with him the end of the hauling wire. After securing the carriage to the wire C
with a lanyard he re-extends the springs D by means of the nuts E' provided on
the screwed rod E, which nuts bear against the ends of the spring boxes D¹.
See fig. 5.
A catch M on the trigger-lever M, whose fulcrum is at F¹ on the cross-bar F.
temporarily engages with a notch N' in the trigger-frame N. and thus the extended
springs are secured whilst the nuts E' are brought back and locked against the
crossbar F once again-see fig. 5.
The hauling-wire J is again attached to the Bridle-lever L which as the wire
tightens is drawn up in front, as shown in fig. 6. To assist the proper working of
this a spring O attached to the shorier end of the lever L (whose fulcrum is at L,
the front wheel axle) is secured at its upper end to the pawl K below its fulcrum K³,
and it thus tends to draw down the toe K of the pawl into its proper position (In
figs. 1 & 5 the pawl K is drawn canted to one side to show the freedom given to the
crossbar to fall back) The angular movement of the lever in being drawn up
brings a roller L3 into contact with the rounded toe K2 (this toe may be tapered off
considerably) and as this continues the pawl K is securely locked even tho' as yet
it has nothing to hold since a gap exists between the top of the pawl and the position
then occupied by the cross-bar F. The angular movement of the lever L continuing
contact is made with the toe of the trigger-lever M. and finally the catch M' is thrust
up and out of the notch N. This releases the bar and it flies back and presses
against the pawl K. This little recoil makes it now quite impossible for the catch M'
to re-enter N of its own accord. The whole clutch gear is now set, ready for action
as soon as the hauling-wire again gives way. See fig. 6. The workman removes the
lanyard and all is in working order again.
Suppose the wire J to break again :-then the lever L falls, partly by its own 4
weight & partly assisted (to any desired extent) by the beforementioned spring O
which thus performs a double duty. By this movement the pawl K is released and
thus the cross-bar F is left free to be drawn back by the full power of the springs D.
The levers G being attached to F fall back with it and draw the clutch-blocks A, A¹,
against the wires-see fig. 3. It must be noted that the action of the oblique levers,
whose positions are shown at A in fig. 3, thrusts the blocks A' forcibly against the
wires when the levers H draw then forward; and not only this, the tendency of
the carriage to run back intensifies this grip when once set up.
In order to avoid damage to the standing-wires I use an inner lining for the
clutch-blocks made of india-rubber, soft metals, such as lead, leather, or other such
yielding substances.

page_text: The springs D may have a further tightening arrangement at the tail end so as to
regulate the intensity of their pull.
When a carriage is lowered to the very bottom of the standing-wires and touches
the anchorage contact is made with the tail-end P1 of the gear P. This gear is
carried to the front of the carriage by suitable guides and carriers and the nose
end P is there firmly guided between sliding paths as shown. When this gear
is pushed forward P projects forward and engages with the cams L on the
axle L of the bridle-lever L and thus prevents it from falling down even if the
hauling-wire becomes slack-Suitable springs (not shown) may be arranged to
draw this gear back when it is freed by leaving the anchorage. See figs. 6 and 9.
One or more Safety-bolts may be fitted on both sides of a carriage-One is shown
at Q in fig. 1, also in fig. 2, and in fig. 4, upside down.
It will be seen that these bolts extend across and under the standing-wires C
and their ends are encased in shields as shown at Q¹.
When a "Jumper" is being passed the bolt is pushed to one side, right or left,
and is afterwards returned, automatically, by the action of the springs R. R.
which are shown engaging with studs on this swinging bolt Q. By arranging a
bolt as near as convenient to the wire and by giving an extra depth to the wheel
flanges it makes it impossible for a carriage to leave the wires.
In order however to avoid danger when passing a "Jumper "additional bolts S
are attached to the side-frames and pass under projecting ribs Tarranged on the
side of the "Jumper" T, see fig. & 2. These projecting ribs must be of
suitable length so as to mount guard until the bolt Q swings back under the wire.
A modification of the whole may be arranged so that the tub of a loaded
carriage may be made to give the necessary gripping power to the clutches.
This by arranging that (1) the weight of the tub and its load hang on gear
connected with the clutches, and (2) that that the necessary freedom be given to
fall thro' the distance required when released.
In figs. 8 and 9 the tub B¹ has trunnions which project thro' the slotted
holes B³ in the side-frames B and are borne by the side-levers U whose fulera
are at U (one on each side frame) The short arm U2 engages with the cross-
bar F to which the levers G are attached, and these couple up with the clutches
as before described. The long arm U³ is supplied with a lifting arrangement
worked by screws say as shown at V. These lifting screws which are an equivalent
to the screwed rods E in the former arrangement may be worked by a windlass
and ratchet as shown. The remainder of the gear, pawl, temporary trigger-
catch, &c., are all similar to those first described.
In fig. 9 the nose ends, P2, are clearly shown in relation to the cams L on
the fulcrum-shaft L2 of the lever L: the whole being arranged (i.e. the whole of
the latter) to swing round along with the lever L which may be fitted with
bridle chains for distributing the pull to the ends of the shaft.
The invention is also applicable to carriages working in vertical and inclined
shafts.
For a vertical shaft powerful springs would have to be used, 1st to pull the
bridle-lever over, and, 2nd, to actuate the clutches. No weight of load arrange-
ment could be applied.
In an inclined shaft, or on any inclined tramway, the clutches could be made
to grasp any projecting rail such as permitted a grip to be given to it.
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 improved spring and Lever Clutch Gear, with modification for acting
by the Weight-of-load, Safety-bolts Q, and Hook-bolts S for engaging with
"Jumpers," (applied to carriages in the manner explained) arranged, constructed,
and operated substantially as described and shown, with the object and for the
purpose set forth.
2. The novel arrangement of releasing the gear by the falling of the lever L

page_text: r
at right-angles to the line of haulage, with the object and for the purpose set
forth.
3. The Safety-bolts and Hook-bolis S for engaging with the "Jumpers,"
substantially as described and shown, with the object & for the purpose set forth.
4. The application of an inner lining to the clutch-blocks made of some yielding 5
substance such as india-rubber, soft metals such as lead, leather, and the like, for
the purpose of avoiding damage to the standing wires.
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