Note: Descriptions are shown in the official language in which they were submitted.
2lns~0~
FIELD OF THE INVENTION
The present invention relates to an apparatus for
oscillating users in a generally vertical plane by means of an
elastic cord or bungee cord.
BACKGROUND OF THE INVENTION
Bungee jumping is a sport which has developed in the
last decade. The user jumps off a high-level jumping platform
being attached to an elastic cable or bungee cord. After his
vertical oscillations have subsided, the jumper is lowered to
the ground by means of a non-elastic cable attached to the
bungee cord and to a winch or the like which serves to pay-out
and retrieve the non-elastic cable and the bungee cord. It
has been found that known bungee jumping systems lack in
safety features with the result that jumpers have accidents.
Known jumping systems are also static structures being
intended to be erected and permanently used on one site with
the result that after a few seasons, the clientele of jumpers
becomes depleted.
OBJEcTs OF THE INVENTION
The general object of the present invention is to
provide a bungee jumping system which has a number of safety
features to considerably reduce the occurrence of accidents to
the jumpers and attending personnel.
Another object of the present invention is to
provide a system of the character described which is quickly
erected and dismantled and is easily transported from one site
to another.
Another object of the invention is to provide a
system of the character described further including a ladder
provided with two jumping platforms at two different levels to
accommodate jumpers of different degrees of bravery, and which
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can be used at the same time to increase the jumping capacity
of the system.
Another object of the invention is to provide a
bungee jumping system which can also be used for catapulting
a user from ground level up in the air.
SUMMARY OF THE INVENTION
The apparatus of the invention serves to oscillate
users in a generally vertical plane and comprises an elongated
base structure, a ladder made of several ladder sections,
releasable securing means to secure said ladder sections in
alignment, pivotal means connecting the lower end of the
ladder to the base for raising and lowering movement of the
ladder in a vertical plane, power means carried by the base
structure to raise the ladder to a steeply inclined operative
position, a jumping platform secured to the topmost section of
the ladder and protruding at an angle thereto and horizontally
disposed when the ladder is in operative position, a bungee
cord, means to attach one end of the bungee cord to a user, a
pulley carried by the top of the ladder above the jumping
platform, a non-elastic cable trained on the pulley and
attached to the other end of the bungee cord and power
operated means to pay-out and retrieve the non-elastic cable
between a retracted position adjacent said pulley in which a
user attached to said one end of said bungee cord is suspended
above ground even when said bungee cord is fully stretched,
and an extended position in which said one end of said bungee
cord is closer to the ground and allows the attached user to
land.
Preferably, the several ladder sections are serially
hinged to each other for pivotal movement between an
accordeon-like folded position and an unfolded aligned
position, the assembly of the sections when unfolded having an
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overall length several times that of the elongated base
structure and the assembly of the folded sections having a
length generally the same as that of said elongated base
structure, which is preferably a wheeled roadable base
structure to be towed by a road tractor. The power operated
means to pay-out and retrieve the non-elastic cable preferably
consists of a double-acting hydraulic ram having a fixed end
and a movable end, a fixed assembly of return pulleys at said
fixed end of said hydraulic ram, a movable assembly of return
lo pulleys carried by the movable end of said hydraulic ram, the
non-elastic cable being trained several turns around the
return pulleys and fixed at one end adjacent the fixed
assembly of pulleys. Shortening and lengthening of the
hydraulic ram causing pay-out and retrieving of the non-
elastic cable to an amount which is a multiple of the stroke
of the hydraulic ram whereby the latter can be installed on
the base structure. A flow control valve automatically blocks
the hydraulic ram against extension or contraction movement
should the oil pressure inadvertently fall below a
predetermined level.
The user, while climbing the ladder is always
attached to a safety cable running along the ladder by means
of a safety slider which allows ladder climbing but prevents
falling movement.
Preferably the bungee cord is suspended from a pair
of non-elastic cables, each of sufficient force to retain the
jumper should the other cable break.
Preferably the jumping platform has safety gates
arranged to delimit a jumping area accessible to one jumper at
a time, one of the gates closing a ~umping orifice made in the
guard rail surrounding the jumping platform, therebeing
provided a spring supported pad which is linked to the gates
~4 2109908
so as to unlock one gate while locking the other and which is
responsive to the presence of the user on the pad so that the
jumping orifice gate is unlocked only when the jumper is
standing on the pad ready to jump.
The user wears a harness to which the free end of
the bungee cord is removably attached. Preferably the
apparatus also includes means to serve to catapult a user from
ground level up in the air and to land the user. This
catapulting system includes retaining means to temporarily
retain the other end of the bungee cord at ground level while
the non-elastic cable means is in retracted position with the
bungee cord in stretched condition and further including
releasing means to release said retaining means to cause the
bungee cord to pull the attached user upwardly. Preferably
the retaining means includes a weighted block adapted to rest
on the ground and link means linking the block to the harness,
the releasing means serially connecting the link means to the
harness, the block being of a weight sufficient to resist the
pull of the stretched bungee cord. Preferably, a scale with
a read-out is serially interposed in the link means to
indicate the pull exerted by the stretched bungee cord.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings, Figure 1 is a side
elevation of the bungee jumping system in transport mode;
Figure 2 is a rear end elevation of the same taken
along line 2 of Figure 1;
Figure 3 is a partial elevation showing the hinge
between two ladder sections and taken along line 3-3 of Figure
2;
Figure 4 is a top plan view of the trailer shown in
Figure 1 and showing how the ladder sections are unfolded;
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Figure 5 is a side elevation of the extended
outrigger arm, this view taken along line 5 of Figure 4;
Figure 6 is a cross-section taken along line 6-6 of
Figure 2 and showing the ladder raising telescopic hydraulic
cylinder in retracted position;
Figure 7 is a side elevation of the ladder assembly
in half-raised position on the trailer;
Figure 8 is a partial side elevation on an enlarged
scale of one of the two pivotal connections of the ladder to
the trailer and taken in area 8 of Figure 7;
Figure 9 is a cross-section taken along line 9-9 of
Figure 8;
Figure 10 is a side elevation of the ladder and
trailer with the ladder in a fully raised, operative position
lS and properly stabilized by guy wires and braces ready to be
used;
Figure 11 is an end elevation of the assembly of
Figure 10;
Figure 12, seen on the seventh (7th) sheet of
drawings, is a cutaway top plan view of the cable pay-out and
retrieval system and taken in an area delimited by line 12 in
Figure 4;
Figure 13 is a longitudinal section taken along line
13-13 of Figure 12;
Figure 14 is a cross-section taken along line 14-14
of Figure 12;
Figure 15, seen on the sixth (6th) sheet of
drawings, shows the connection of a brace to the lower-level
jumping platform and taken in area 15 of Figure 11;
Figure 16 is a partial side elevation taken in area
16 of Figure 11 and showing the pivotal connection of the
lower end of a ladder brace to the platform;
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Figure 17 is a cross-section taken along line 17-17
of Figure 16;
Figure 18 is a partial elevation on an enlarged
scale taken in area 18 of Figure 11 and showing how the top
end of the ladder brace is connected to the ladder;
Figure 19, seen on the eighth (8th) sheet of
drawings, is a plan section taken along line 19-19 of Figure
11 and showing the high level jumping platform;
Figure 20 is a partial vertical section taken along
line 20-20 of Figure 19;
Figure 21 is a vertical cross-section taken along
line 21-21 of Figure 19;
Figure 22 is a partial elevation taken along line 22
of Figure 19;
Figure 23 is a plan section taken along line 23-23
of Figure 11 and showing the low level jumping platform;
Figure 24 is a side elevation of the low-level
jumping platform;
Figure 25, seen on the ninth (9th) sheet of
drawings, is a partial elevation of the ladder and a front end
elevation of the low-level jumping platform, and taken along
line 25 of Figure 24;
Figure 26 is a partial vertical section taken in
area 26 of Figure 22;
Figure 27 is a schematic plan section taken along
line 27-27 of Figure 26;
Figure 28 is a partial elevation taken in area 28 of
Figure 25;
Figure 29 is a schematic plan view of the system
shown in Figure 28;
Figures 30 and 31 are a partial side elevation and
a front elevation respectively showing the top end of the
~ 2109~08
ladder, the double pulley, and the attachment of the bungee
cord to the pay-out cables, these Figures being taken in area
30 of Figure 7;
Figures 32 and 32A show the jumper harness in side
elevation and back elevation and attached to the lower end of
the bungee cord;
Figure 33 shows the jumper harness in front
elevation while the jumper is oscillating;
Figure 34 is a partial elevation taken in area 34 of
Figure 32 and showing the attachment of the lower end of the
bungee cord to the harness;
Figure 35 is a partial elevation of the safety cable
and safety slider; and
Figure 36 is partial elevation of the catapulting
system and showing the user about to be catapulted.
In the annexed drawings, like reference characters
indicate like elements throughout.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The bungee jumping system comprises a ladder 2
pivoted at its lower end by hinges 4 to a base structure,
namely a base platform 6 which forms the top of an elongated
roadable trailer 8 mounted on tandem wheels 9 and which is
hinged at its front end by a conventional fifth wheel to a
driving tractor 10.
Ladder 2, which may have a length of 100 feet, is
composed of a trestle-work 12 supporting a series of steps 14
(see ~igure 20) and the climber is protected by longitudinally
extending guide rails 16. A low-level jumping platform 18 and
a high-level jumping platform 20 are secured to the trestle-
work 12 of the ladder. Ladder 2 is made of three ladder
sections of substantially equal length namely, a lower section
22, an intermediate section 24 and a top section 26. As shown
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in Figure 4, the three ladder sections are serially hinged to
each other by hinges 28 and 30 having their hinge axes normal
to the hinge axis of hinge 4 and disposed on opposite sides of
ladder section 24. Thus the ladder sections 22, 24 and 26 can
be folded and unfolded in accordeon-like manner and in a
horizontal plane, laterally of the platform 6 when the
sections 22, 24 and 26 are in a horizontal position.
Obviously it is the bottom section 22 which is hinged to
platfQrm 6 by the two laterally spaced hinges 4, one of which
is shown in Figure 9. Hinges 4 are disposed in the front
portion of platform 6. The three modular sections 22, 24 and
26 can thus take a folded position in which the three sections
are disposed side by side longitudinally of the platform 6
within the lateral confines of the platform 6.
The ladder sections 22, 24 and 26, once unfolded and
positioned in mutual alignment, are locked in this aligned
position by bolts and nuts (not shown), the bolts inserted
into holes 32 made in the ends of the trestle-work 12 of the
respective ladder sections (see Figure 2). The arrangement is
such that, in the transport mode, the ladder sections 22, 24
and 26 rest horizontally on the platform 6 of the trailer 8
being shorter than the latter.
A power operated means is provided to raise and
lower the ladder 2 between a horizontal position and an
operative position in which the ladder is steeply inclined as
shown in Figure 10. These means consist of a single-acting,
telescopic hydraulic cylinder 34, hinged intermediate the end
of its bottom section at 36 below the platform 6 about a
horizontal transverse axis. Cylinder 34 extends through an
opening 38 made in platform 6 and its top end is pivoted at 40
to the upper end of the bottom ladder section 22.
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Stabilizer means are provided to stabilize the
ladder in its operative position. The stabilizer means (see
Figures 10 and 11) includes concrete blocks 42 which serve as
counterweights disposed on the front end of the platform 6,
guy wires 44 and 46 which are attached to the top ladder
section 26 and to the front end and at the rear end
respectively of the platform 6. The stabilizer means further
includes laterally extending outrigger arms 48 which laterally
extend from the opposite ends of the rear end of platform 6,
more specifically as shown in Figures 1, 4 and 5. Each
outrigger arm 48 is made of telescopic arm sections 50 which,
when in telescoped condition, are stored within a transverse
retainer tube 52 fixed to the structure of the trailer 8
underneath the rear end of platform 6 such that the entire
outrigger arm 48 is stored within the lateral confines of the
trailer. The two outrigger arms 48 are offset with respect to
the longitudinal axis of the trailer 8 so that the retainer
tubes 52 are disposed side by side behind the tandem wheels 9
of the trailer 8. When extended, the telescopic arms sections
50 are locked in position by pins 54. The outermost arm
section 50 carries a ground engaging, vertically adjustable
leg 56, each outrigger arm 48 is reinforced against upward
movement by a brace 58 and an intermediate vertical strut 60.
Both the brace 58 and strut 60 are connected to the arm
sections 50 and to the trailer structure by removable pins so
that they can be dismantled and stored longitudinally under
the trailer platform 6 within the trailer structure.
The back guy wires 46 are preferably directly
attached to the top end of the assembly of the ground engaging
leg 56 and also, if found necessary, to a concrete block 62
disposed adjacent leg 56. In practice blocks 62 have been
found to be unnecessary.
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The stabilizing means further include (see Figures
10 and 11) a pair of rigid braces 64 each secured to the top
of bottom ladder section 22 by a connection 66 ~see Figure 18)
and attached at their lower end to the platform 6 by a pivotal
connection 68 tsee Figure 16). The two braces 64 are
downwardly diverging. Obviously, during use, the platform 6
is further stabilized by the conventional jacks 70 normally
associated with a trailer and used when the driving tractor 10
is disconnected therefrom.
Figure 10 also shows a stairway 72 to allow users to
step up to the platform 6 from ground level. Stairway 72 is
a unit which can be disconnected form the platform 6 and
stored on the latter for transport of the whole assembly.
Referring to Figures 7, 10, 11, 20 and 21, there is
provided a high-level jumping platform 74 which protrudes from
the underside of the ladder 2 at an obtuse angle relative to
the same such that when the ladder is erected in operative
position as shown in Figure 10, it will be horizontal. The
jumping platform 74 is an assembly which is removably
connected to the top ladder section 26 such that this section
can rest flat on the trailer platform 6 when the ladder is in
folded transport mode.
The steps 14 together with the guard rails 16
terminate at the platform 74 and the ladder is also provided
with a guard rail 76 which has an exit opening 78 formed at
the end of the cross-leg 80 of the platform 74 which is L-
shaped when shown in plan section (see Figure 19).
A slidable safety gate 82 normally closes the exit
opening 78; a second safety gate 84 is disposed at the
entrance of the jumping platform at the end of the ladder
steps 14.
2 1 0 9 9 08
A pad 86 (see Figures 19, 21, 22, 26 and 27, is
horizontally positioned on the platform 74 just inside the
exit opening 78. Pad 86 is guided for up and down movement
between an upper and a lower position and spring pressed to an
upper limit position by a pin and sleeve and coil spring
assemblies 88 as shown in Figure 26. When the jumper stands
on pad 86, the latter is depressed to its lowermost position
and actuates a mechanism which unlocks the exit safety gate
82, SQ that the latter may be opened by an operator standing
beside the jumper, and simultaneously locks the entrance
safety gate 84 so as to prevent access of the next jumper to
the jumping platform while the first jumper is preparing to
jump. This locking and unlocking mechanism includes a rod 90
secured to the underside of pad 86 and engageable with a lever
92 which is pivoted intermediate its ends at 94 about a
horizontal axis. Rod 90, upon depression of pad 86, causes
lever 92 to pivot counterclockwise (see Figure 26) from its
full line position to its dotted line position.
Exit safety gate 82 (see Figure 22 and 26) includes
a U-shaped tube 96 slidable in sleeves 98 horizontally
disposed one below the other and fixed to the guard rail 76.
Similarly, the entrance safety gate 84 includes a U-shaped
tube 100 slidable in sleeves 102 which are horizontally
disposed and are secured to the guard rail 74 and laterally
outwardly protrudes from the same. The lower one of each
sleeve 98 and 102 is provided with a nipple 104 secured to and
downwardly protruding therefrom. In this nipple is mounted a
locking pin 106 which is spring pressed by spring 108 into a
position entering sleeve 102 and also a hole 110 made in the
tube 100 when said tube is in closed position. This locking
arrangement is the same for both safety gates 82 and 84.
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-
Each locking pin 106 is connected to a pulling rope
namely a pulling rope 112 for the U-shaped tube 96 and 114 for
U-shaped tube 100. The two pulling ropes are trained on
pulleys 116 and are attached to opposite ends of the lever 92.
The spring 108 of the locking pin 106 which is associated with
the exit gate 82 is stronger than the spring of the other gate
whereby lever 92 is pulled in to the normal position shown in
full line in Figure 26 wherein the exit gate 82 is locked when
the same is closed and the entrance gate 84 is unlocked.
When the jumper stands on the pad 86, the exit gate
becomes unlocked while the entrance gate, when in closed
position, is automatically locked.
The ladder 2 is also preferably provided with a low-
level jumping platform 120 as shown in Figures 7, 10, 11 and
25. This platform 120 is fixed to the top of the bottom
ladder section 22 and laterally extends therefrom. It is in
horizontal position when the ladder is in fully erected
position as shown in Figure 10. Jumping platform 120 is
releasably fixed to an angular framework 122 so that it may be
removed such that the ladder in transport mode will not exceed
the sides of the trailer 8. AS shown in Figures 10 and 11,
the jumping platform 120 is stabilized by a pair of braces 124
which are pivotally connected to the platform 120 and to the
trailer platform 6 by connector pins 126 such as shown in
Figure 15. Jumping platform 120 has a guard rail 128 on both
its longitudinal sides and it has an exit gate 130 (see
Figures 24 and 25) and also an entrance gate 131 behind gate
130. The jumping platform 120 has also a pad 86A with a gate
locking and unlocking mechanism similar to that just described
in connection with the high-level jumping station and which is
schematically illustrated in Figures 28 and 29, the only
difference between the above described locking mechanism lies
-13- 2109908
in the fact that the lever 92A has a different shape than that
of lever 92 while the ropes 116A and 118A are attached to the
same end of the lever 92A instead of two opposites ends
thereof. Also, the positioning of the pulleys is different.
Here again, supposing the exit gate 130 is closed and locked,
the same will become unlocked upon a jumper stepping on pad
86A. Simultaneously the entrance gate 131 will become locked
supposing that it is in closed position.
The safety gates are shown as horizontally
displaceable so that an operator must manually move the same
from closed to opened position and vice versa. However it is
possible to incline the sleeves 98 and 102 so that the gates
will automatically take a normally closed position.
An important safety feature is the provision of
safety cables which runs the whole length of the ladder 2 and
along the jumping platforms 74 and 120. A ladder safety cable
132 (see Figures 20 and 25) runs along practically the whole
length of the ladder 2 alongside one guard rail 16 being
attached at its ends 134 and to the top of guardrail 16 and
also below the low-level jumping platform (not shown).
Similarly, the high-level jumping platform is provided with a
horizontal cable 138 (see Figures 20 and 22) which is attached
at both ends at 140 and at 142 to that one of the guard rails
76 which is closer to cable 132. The low-level jumping
platform 120 is provided with a similar cable 138A attached to
guard rail 128 at 140A and 142A.
The jumper A (see Figures 32 to 35) wears a jumping
harness 144 comprising a torso strap assembly 146, a waist
belt 148 and thigh belts 150, connected together by strapping
152 and by front and back metal ring 154 and 156. To the
waist belt 148 is attached by means of a strap 157 and of a
karabiner 158 a safety slider 160 which consists of a U-shaped
210ggO8
plate slidably surrounding the safety cable 132 and to which
is pivoted a brake lever 162 which is inclined with respect to
the safety cable and spring pressed to slide on the same when
the slider 160 is pulled upwardly along the cable but which
automatically brakes and stops the slider when the same is
pushed or pulled downwardly along the cable. Therefore, a
jumper is free to climb the ladder 2 while pulling the safety
slider 160 along the ladder safety cable 132. Should the
jumper or any user accidentally fall off the ladder steps, he
will automatically be kept from falling down the ladder by the
locked slider 160. There are several sliders along ladder
safety cable 132 and a few on each of the jumping platform
safety cables 138 and 138A. When the jumper reaches the top
of the ladder 2, he detaches himself from the slider 160 on
the ladder safety cable 132 and attaches his karabiner 158 to
a slider 160 on horizontal cable 138 of the high-level jumping
platform so as to move along said platform while being safely
hitched against accidental fall. When the jumper is on the
pad 86 and is ready to jump, the operator or himself opens the
karabiner 158 to release the slider.
The operator beside the jumper, who stands on the
pad 86, attaches the lower end of a bungee cord 164 to the
front ring 154 of the jumping harness 144. The bungee cord
164 is made of several elastic bands for instance, 500 of the
same. The bungee cord (see Figures 30, 31 and 34) is folded
into two strands with the lower ends of the strands inserted
and fixed within a fitting 166 which has an eye 168 which
serves to attach the bungee cord to the front ring 154 by
means of two karabiners 158 and short straps 170. The lower
portion of the bungee cord 164 adjacent the user is wrapped
within a cylindrical cushion 172 made of plastic foam covered
with a sheeting and which serves to prevent injuries to the
-15- 2109908
jumper by the bungee cord when the jumper oscillates up and
down.
Referring to Figures 7, 10, 30 and 31, it is seen
that the top end of the bungee cord 164 is attached to a pair
of non-elastic pay-out and retrieval cables 174 which are
trained on double pulleys 176 which are suspended from a bar
178 fixed to the top end of the ladder. The two cables 174
extend all the way down the ladder 2 and are connected to a
pay-out and retrieval system 180 which is carried by the
trailer platform 6 as shown in Figure 4 and which will be
described hereinafter.
Referring again to Figures 30 and 31, the two cables
174 are used instead of one as a safety measure, one cable
being sufficient to resist the stress imposed by the jumping
user so that in the event of failure of onè cable, the
remaining cable will not break. The double pulley 176 is
suspended by a karabiner 158 and a ring 182 from the bar 178,
the ring being positioned between two retaining collars 184
fixed by set screws 186. The double pulley block 188 is
provided with cable keeper rollers 190 to prevent the cables
from jumping off the pulley. The double pulley block 188 is
further attached to the top end of the ladder 2 by cable ties
192 so that if the karabiner 158 or ring 182 or bar 178 fail
under stress, the pulley block 188 will remain attached to the
ladder 2.
Weights 194 are attached to the outer ends of cables
174 in order to stabilize them against lateral swinging during
vertical oscillation of the jumper. Each weight 194 is in the
form of a cylinder with a throughbore; they are disposed side
by side with the two cables 174 extending through the
respective weights 194 and attached to a metal clevis 196, the
bolt 198 of which passes through the looped upper end 200 of
the bungee cord 164. For safety reason~ ltQe9 9Q~ 202 of
retaining bolt 198 is locked in place by two right angle
cotter pins 204. A collar 206 surrounds the two strands of
the bungee cord just below looped end 200. The two weights
194 are attached to the respective cables 174 by retaining a
cable 208 folded into a U with its two legs extending through
the bores of the respective weights 194 looped below the
weights and with the upper ends of the two legs attached
together by a clip 210 to form a complete loop with the free
ends of the cable 208 respectively attached to the two cables
174 by clips 212. Should one cable 174 break, the two weights
will not fall since it will remain attached to the remaining
cable.
Referring to Figures 4 and 12 to 14, the inner end
of the two pay-out and retrieval cables 174 are connected to
the cable pay-out and retrieval system generally indicated at
180 and which comprises a metal plate 216 fixed flat on the
platform 6 and at one end of which is mounted a fixed pulley
block 218 in which is rotatable, for instance, two sets of
five pulleys 220. A pair of double acting hydraulic rams 222
are disposed side by side longitudinally of and over plate
216, the ends of the cylinders of the two rams 222 being
retained in a saddle 224 carried by the pulley block 218. A
movable pulley block 226 also carrying two sets of pulleys 227
is attached by pins 228 to the outer end of the pistons rod
230 of the telescopic rams 222. The block 226 is guided for
back and forth movement longitudinally of plate 216 by guiding
rollers 232 carried by blocks 226 and in rolling engagement
with tracks 234 carried by the inside walls of beams 236
upstanding from and fixed to the base plate 216.
Each one of the two pay-out and retrieving cables
174 is trained back and forth on one set of five pulleys in
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the fixed block 218 and in the movable block 226. The outer
ends of the respective cables 174 are attached to base plate
216 by clamps 240 adjacent the fixed pulley block 218. The
cables are retained on the respective pulleys by cable keeper
rollers 242 and 244 mounted across the pulley block 218 and
226 respectively.
The two rams 222 are double acting and are each
connected to a hydraulic fluid supply pipe 246 and to a return
pipe (not shown and disposed below pipe 246 in Figure 12) and
the supply and return lines are connected to a reversing
electrovalve 248 which is combined with a flow control valve.
The reversal valve automatically stops at the end of its
stroke when the movable block 226 hits a limit switch 250 or
252. Valve 248 is removably controlled by the operator
standing on the jumping platform, in order to adjust the level
of the top end of the bungee cord 164; by a suitable electric
circuit, he can stop rams 222 at any intermediate position or
he can let the rams reach either their fully extended or their
fully contracted position where they stop under the action of
limit switch 250 or 252 respectively. In the fully extended
position of the movable pulley block 226, the top end of
bungee cord 164 will be at its highest level just below double
pulley 176. By retracting rams 222, the jumper will be
brought to ground level after his jump is terminated. For
better safety as shown in Figure 10, the jumper may be lowered
into an above-ground swimming pool S after the vertical
oscillation of the jumper have subsided. It will be noted
that when the two reversing valves 248 are in closed position
(there being one valve for each ram 222), they block
completely entrance and exit of the hydraulic fluid through
the lines 246 and consequently the movable pulley block 226 is
positively stopped. Therefore, the system is very safe. It
21 0~908
is noted that such a system has been accepted by the safety
authorities of the Province of Quebec concerning bungee
jumping while such authorities absolutely refuse the use of a
winch with a braking system since they consider such a winch
not sufficiently safe.
The system 180 is provided, as noted above, with a
flow control valve which is set to about 500 pounds, that is,
if the hydraulic pressure accidentally falls below such a
value the reversing valve automatically closes the supply and
return circuits and locks the rams against further extension
or contraction.
The cable pay-out and retrieval system 180 takes a
minimum of place since for a ram stroke of about 10 feet, each
cable 174 will be paid-out or retrieved a length of about 100
feet, therebeing five pulleys in each set, the two cables
being trained in parallel for safety purposes.
The low-level jumping platform 120 (see Figures 11,
23 and 24) is also provided with a cable pay-out and retrieval
system 18OA which being shorter than the system 180 of the
high-level jumping platform, is positioned on the low-level
jumping platform itself, otherwise, this system 180A is of the
same construction as system 180 and the pay-out cables 174A
connected to the same are trained on double pulleys 176A
carried by a structure 254 above the low-level jumping
platform, outwardly of the safety gate, and on one side
thereof, as shown, a bungee cord attached to the cables 174A
is of the same type as bungee cord 164, only shorter, and is
attached by the means described in Figures 30 and 31.
It is noted that both jumping platforms can be used
simultaneously and the oscillating jumpers will not interfere
with each other since the jumping points of both platforms are
horizontally offset a substantial amount in the plane of the
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inclination of the ladder and also to a lesser amount,
laterally of the ladder as seen by comparison of Figures 19
and 23 wherein the length of the lower platform which
protrudes laterally from the ladder is greater than the length
of the cross-leg of the higher-level jumping platform which
also protrudes laterally of the ladder.
The laterally offset position of the pulleys 176,
176A with respect to the jumping points of the high-level and
low-level jumping platforms respectively (see Figure 25) is
selected such that there will be no interference between the
jumper, the ladder and the guy wires and braces stabilizing
the ladder should there develop a horizontal component of
movement during the vertical oscillation of the jumper.
The system is very safe. Redundant means have been
provided wherever there is a safety hazard. The persons
climbing the ladder are constantly attached to the safety
cable.
Apart from the operator standing on the jumping
platform, only one jumper is allowed on the same for
preparation for jumping due to the presence of the safety
gates.
The exit safety gate is unlocked only when the
jumper stands on the pad 86 or 86A when he is actually ready
to jump.
The whole ladder system and components can be easily
lowered and folded and positioned on a trailer 8 to be moved
to another site and the entire system can be quickly erected.
Referring to Figure 36, there are shown means for
catapulting the user up in the air instead of the latter
jumping from either platform 74 or 123. The erected ladder 2
is used as shown in Figures 10 and 11 with the addition of a
concrete block 256 which is positioned on the ground G
2tO9~08
approximately in line with the swimming pool S looking at
Figure 10, and just laterally of one of the outrigger arms 48
and concrete block 62 looking at Figure 11. The user wears a
harness 258 and the outer end of the bungee cord 164 is
attached to the back of the harness 258 by means of a
karabiner 260 removably attached to a ring 262 which is
anchored to a block 264 fixed to the back of the harness 258.
A cable link 266 is attached to the concrete block 256 by a
cramp 268 and to a ring 270 which is in turn releasably
attached to the block 264 and which may be quickly manually
released therefrom by a releasing mechanism of any known type
in block 264. Finally, a scale 272 is serially connected in
the cable link 266, the scale 272 having a read-out display
274 indicating to the operator the pull exerted by the
stretched bungee cord 164.
The catapulting system is operated as follows:
using the cable pay-out and retrieval system 180, the non-
elastic cable 174 is paid out so as to lower the bungee cord
164 sufficiently for the operator on the ground to grasp the
lower end of the bungee cord and attach it to the user A by
means of the karabiner 260. The user is then attached to the
concrete block 256 by means of the releasable ring 270. The
cable pay-out and retrieval system 180 is retracted so as to
cause the double cable 174 to stretch the bungee cord 164 in
sufficient amount as read on the read-out 274 of the scale
272. Obviously the concrete block 256 must have a weight
sufficient to resist the pull of the stretched bungee cord.
Then the operator releases the ring 270 from the block 264 and
the user is catapulted or hurled up in the air in a vertical
plane which is generally co-planar with the upper end of the
ladder 2 but in a vertically inclined trajectory due to the
above-noted position of the concrete block 256, thus clearing
21~9908
the upper end of the ladder 2 as well as the guy wires 46.
After oscillation has subsided, the user is gradually lowered
to the ground by again lowering the upper end of the bungee
cord 164.
