Portable device for storing an endless metallic or fiber-optic cable

A portable trailer supports a long horizontal tube on which is mounted a rotatable and reciprocable drum and a fixed storage reel. The center tube, reel, and drum contain alignable longitudinally extending radial slots therethrough. Attached to the drum and extending over the reel is a bail and a series of snatch blocks. A slack cable is inserted transversely through the aligned slots in the drum, center tube, and reel such that it lays in the interior of the center tube. The cable is looped inside the reel and then transversely inserted into the bail and snatch blocks. Rotating and reciprocating the drum neatly winds the cable onto the storage reel from a supply reel, although there is no access to the cable ends.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention pertains to cable handling, and more particularly to 
apparatus for laying underground cable. 
2. Description of the Prior Art 
The contribution of fiber-optics to the communications age is well known. 
With fiber-optics, thousands of messages can be transmitted simultaneously 
through a single fiber. 
A major problem associated with fiber-optic technology concerns the 
placement and protection of the fiber-optic cables. It is generally 
accepted practice to lay fiber-optic cables underground below the frost 
line. Various equipment has been developed to efficiently lay the cable 
across fields and other unobstructed areas. However, substantial 
difficulties are encountered when the fiber-optic cable must be laid under 
such obstructions as highways, railroads, and gas and oil pipelines. 
Splicing fiber-optic cables is both costly and detrimental to the strength 
and quality of the light signals to be pulsed through the cables. 
To lay splice-free cables under various obstructions, it is known to unwind 
an entire supply reel of cable at the obstruction. The cable is pulled 
back and strung in one or more long loops stretching away from the 
obstruction. The cable free end is then fed through a bore under the 
obstruction. Finally, the cable is rewound on the supply reel located on 
the downstream side of the obstruction. A variation of the pull-back 
method is the FIG. 8 method. The cable is entirely unwound from the supply 
reel, but it is laid in the form of several overlapping figure-8s on the 
ground. Both the pull-back and figure-8 methods are very time consuming 
and therefore costly ways of passing cables under obstructions. Further, 
laying the fiber-optic cables on the ground renders them susceptible to 
damage by machinery and personnel in the area. 
Manitou Industries of Neilburg, Saskatchewan, Canada has developed 
apparatus that eliminates the need for laying the cable on the ground at 
an obstruction. The Manitou device employs a pair of special cable reels 
that give access to the cable free end underlying the overlying cable of 
the supply reel. At an obstruction, the plow supply reel is unloaded from 
the plow and placed on the ground. The cable free end is pulled from the 
special reel and is partially unwound by an unwinding tower attached to 
the reel. The cable free end is passed under the obstruction. The cable 
free end is then wound onto a second special reel on a trailer located on 
the downstream side of the obstruction simultaneously with unwinding the 
cable from the original supply reel attached to the unwinding tower. The 
second reel is then unloaded from the trailer and loaded onto the plow, 
where it becomes the plow supply reel for supplying cable until the next 
obstruction is reached. At the next obstruction, the reel unloading, 
unwinding, rewinding, and reloading process is repeated. Although the 
Manitou system is an improvement over merely laying the cable on the 
ground, it nevertheless requires substantial time to unload and load two 
reels at the obstructions. Further, a substantial expenditure is required 
for the special reels and the machinery for handling them. 
Thus, a need exists for improved apparatus and methods for laying 
continuous underground cables. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, portable storage equipment is 
provided that efficiently handles endless metallic or fiber-optic 
underground cable at various obstructions in the cable path. This is 
accomplished by apparatus that includes a rotatable drum and bail that 
temporarily wind the cable onto an adjacent storage reel without requiring 
access to either end of the cable. 
The drum and bail are mounted on a relatively small trailer that is towable 
by a motor vehicle, such as a pick-up truck. The drum is mounted for 
rotation about its longitudinal axis on the trailer. The storage reel is 
fixedly mounted on the trailer adjacent the drum, with the drum and reel 
longitudinal axes being coincident. In addition to rotating, the drum 
reciprocates along its longitudinal axis. The bail extends axially from 
the end of the drum so as to overhang the fixed reel for all axial 
locations of the drum relative to the reel. 
The drum is formed with a radial slot extending the full length thereof. In 
addition, the mounting frame and bearings that rotatably support the drum 
on the trailer have radial slots alignable with the drum slot. A portion 
of the stationary reel also has a longitudinally extending radial slot, 
but the entire length of the reel need not be slotted. The reel slot is in 
angular alignment with the frame slots. A long inner tube loosely mounted 
inside the drum mounting frame also has a longitudinal slot for the 
majority of its length. 
A pair of rollers mounted to the trailer contact and help support the drum 
periphery. A hydraulic circuit operates a pair of motors that drive the 
rollers for rotating the drum. A third hydraulic motor rotates a lead 
screw that cooperates with a drum gripping mechanism to reciprocate the 
drum along its longitudinal axis in timed relation to the drum rotation. 
Also attached to and extending axially from the drum are a series of 
different length strips. A spring loaded snatch block is fixed to the free 
end of each strip. Openings in the snatch blocks cooperate to guide the 
cable in a smooth three dimensional path to the bail. To guide the cable 
running end to the first snatch block, the portable storage equipment of 
the present invention includes a double ended guide funnel. The funnel is 
split longitudinally into two halves, and each half is pivotally mounted 
to the trailer. When the funnel halves are properly located and latched 
together, they mate to capture the cable and create a smooth cable guide. 
In operation, a cable laying tractor or plow with a supply reel of cable 
lays the cable underground in a normal fashion until it reaches an 
obstruction, such as a highway. At that point, the portable apparatus of 
the present invention is brought up and parked near the plow. The drum is 
rotated until the radial slot therein is aligned with the slots in the 
support frame and in the stationary reel. Some slack is produced in the 
cable by the plow. The cable slack is inserted transversely through the 
aligned slots in the support frame, drum bearings, drum, inner tube, and 
reel. A large loop of cable is formed inside the stationary reel and is 
retained in place within a longitudinally slit piece of tubing. The plow 
end of the cable, which remains passing through the reel slot, is wound a 
few turns around the reel, and then it is passed transversely through the 
bail, snatch blocks, and guide funnel. The hydraulic circuit of the 
invention is actuated to rotate and reciprocate the drum together with the 
bail and snatch blocks, thereby unwinding the cable from the plow supply 
reel and winding it onto the stationary reel. 
After the cable is completely unwound from the plow supply reel and wound 
onto the portable storage reel of the present invention, the plow is free 
to cross the obstruction in any convenient and safe manner. The cable free 
end is fed through a bore under the obstruction and then reattached to the 
supply reel on the plow. A reverse procedure is then performed with the 
drum and bail rotating and reciprocating to unwind the cable from the 
temporary storage reel at the same time the cable is being rewound onto 
the plow supply reel. The plow then resumes laying the cable in the normal 
fashion, and the trailer is towed to the next obstruction in the cable 
path. 
Other objects, aims, and advantages of the invention will become apparent 
to those skilled in the art upon reading the disclosure.

DETAILED DESCRIPTION OF THE INVENTION 
Although the disclosure hereof is detailed and exact to enable those 
skilled in the art to practice the invention, the physical embodiments 
herein disclosed merely exemplify the invention which may be embodied in 
other specific structure. The scope of the invention is defined in the 
claims appended hereto. 
Referring to FIG. 1, a portable storage apparatus 1 is illustrated that 
includes the present invention. The storage apparatus is particularly 
useful for cooperating with a conventional plow 3 for laying underground 
flexible cable 5, but it will be understood that the invention is not 
limited to cable laying applications. 
In the normal operation, the plow 3 comprises a tractor 7 designed for 
off-road use over ground surface 9. The tractor supports a supply reel 11 
that holds as much as 19,000 feet of fiber-optic or other endless cable 5. 
The tractor is further equipped with a conventional earth trenching 
device, schematically represented at 13, as is known in the art. The 
trencher 13 opens a trench 15 in the earth and may also be designed to 
fill the trench. The tractor 7 includes suitable means 17 for guiding the 
cable in long smooth arcs from the reel 11 into the trench 15. 
In accordance with the present invention, the portable storage apparatus 1 
is used to assist the cable laying plow 3 to lay the cable 5 under 
horizontal obstructions in the path of the cable route. Typical 
obstructions encountered in cable laying operations include railroad 
tracks, highways, and natural gas and oil pipelines. In FIG. 1, an 
obstruction in the form of a road 19 is illustrated. 
DESCRIPTION OF THE APATUS 
The cable storage apparatus 1 comprises a trailer 21 having a flat 
horizontal frame 23 supported on conventional wheels and axles 25. The 
trailer 21 includes a tongue 27 equipped with a hitch 29 for towing the 
apparatus by a conventional vehicle, such as a pick-up truck, not shown. 
Mounted to the trailer frame 23 is a large cylindrical drum 31. The drum 31 
is mounted for rotation about its longitudinal axis 33 by mechanisms to be 
described presently. Referring also to FIGS. 3-7, a radial slot 38 is 
formed in the drum. The slot 38 extends for the entire length of the drum. 
The drum 31 is partially supported by rollers 37 that are rotatably mounted 
on the trailer frame 23 by suitable brackets 39. The rollers 37 may be 
rubber tires. To rotate the rollers, orbital hydraulic motors 40 are 
fastened to the brackets 39, and the motor shafts are coupled to the 
respective rollers. 
The drum 31 is further supported by a long center tube 41 that extends 
through the center of the drum concentric with the drum axis 3 and that 
projects out both drum ends. The center tube 41 is manufactured with a 
long slot 42 that extends from the tube front end 43 to a location beyond 
the drum back end 44. The tube front end 43 is mounted in a stationary 
manner by a support 45 firmly fixed to the trailer frame 23. In the 
illustrated construction, the support 45 comprises two pairs of braces 49 
joined at their upper ends to housings 46. The center tube passes through 
and is welded to the housings 46. For additional rigidity, a pair of 
plates 51 are welded to the braces 49, and another plate 52 is welded to 
the housings 46. The drum rotates about axis 33 on the tube 41 by means of 
bearings 47, as is best shown in FIG. 3. The bearings 47 have radial slots 
aligned with the drum slot 38. The housings 46 are formed with radial 
slots 48, FIG. 6, that are aligned with the slot 42 in the center tube 41. 
In addition to rotating about its longitudinal axis 33, the drum 31 also 
reciprocates therealong. For that purpose, the drum front end includes a 
flange 53 that is captured by a gripping mechanism 54. Looking also at 
FIGS. 2 and 8, the gripping mechanism 54 comprises two pairs of flat 
rollers 55. The flange 53 is gripped between the pairs of rollers 55, 
which are mounted on short shafts to the top side of a plate 57. To the 
underside of the plate 57 are mounted two pairs of grooved rollers 59. The 
flat rollers 55 and plate 57 are located on a longitudinally extending 
guide plate 61 having tapered edges received by the grooves in the rollers 
59. The ends of the guide plate 61 are supported on the trailer frame 23 
by suitable brackets 63. To reciprocate the drum, a lead screw 65 mates 
with a nut 67 fixed to a horseshoe 69. The ends of the horseshoe 69 
straddle the guide plate 61 and are bolted to the plate 57. To rotate the 
screw 65 and thus translate the drum, the screw is connected by suitable 
drive means 71 to a hydraulic motor 73. The drum reciprocates between the 
position shown in the solid lines of the drawings and a position wherein 
the drum front flange 53 is in the general location shown by the phantom 
lines 53'. 
Mounted to the back end 75 of the center tube 41 is a stationary hollow 
reel 77. The reel 77 may be held in place on the center tube by a handled 
nut 79 threaded onto the center tube end 75. To permit different sized 
reels to be mounted on the center tube, a spacer 81 may be interposed 
between the nut 79 and the reel. The reel is formed with a radial slot 78 
that extends through the reel core 80 and the front flange 82. A slotted 
tube 84 is fixed circumferentially around the inner diameter of the reel 
core 80 at the back end thereof. The slotted tube 84 extends approximately 
three-fourths of the way around the inner diameter of the reel core as is 
best shown in FIG. 7. 
Extending through generally the entire length of the center tube 41 is an 
inner tube 83. The inner tube 83 is loosely contained within the center 
tube, such that it may be freely turned within the center tube. The inner 
tube is preferably made from a synthetic plastic material, such as 
polyvinylchloride. Turning to FIGS. 9-11, the inner tube is fabricated 
with a slot 85 that starts at the front end 86 and extends almost the 
entire length of the inner tube and that passes completely through the 
tube wall. The slot 85 is generally parallel to the longitudinal axis for 
the major portion of the inner tube length. However, near the back end 87 
of the inner tube, the slot 85 deviates in an angular manner for a short 
distance at locations 89. A short offset section of longitudinal slot 85' 
joins the two angular sections 89, thereby forming a lip 88 of material. 
The slot 85 terminates at a location 96 that is between the flanges of the 
reel 77 when the inner tube is inserted into the center tube. Preferably, 
the slot end location 96 is close to the reel front flange 82. To 
facilitate locating and turning the inner tube within the center tube, the 
inner tube front end is formed with a flared portion 91. 
Attached to the periphery of the drum 31 is an arm 35 that extends 
longitudinally over the back end 44 of the drum, as best seen in FIGS. 2 
and 7. To the free end of the arm 35 is fastened a hook-like bail 36. 
Also extending longitudinally from the back end 44 of the drum 31 are a 
series of stiff strips. Five strips 93a-93e are illustrated in FIGS. 1, 2, 
4, and 7, but it will be appreciated that more or fewer strips may be 
employed. The strips 93 are spaced circumferentially around a portion of 
the drum periphery. The strips are of unequal length, with one end strip 
93a being the longest, and the opposite end strip 93e being the shortest. 
The shortest strip 93e terminates forward of the back flange 95 of the 
reel 77 when the drum is in the backmost position, i.e., when the drum is 
in the position in the solid lines of the drawings. To increase the 
rigidity of the strips, their free ends may be connected together with 
cross strips, such as strip 92 between strips 93b and 93c in FIG. 2. For 
clarity, the other stiffening strips are not shown in the drawings. 
Attached to the free end of each strip 93a-93e by any suitable means, such 
as a plate 94, is a respective snatch block 97a-97e. With particular 
attention to FIGS. 12 and 13, the snatch blocks 97 may be composed of two 
symmetrical halves 99 pivotally joined by a spring loaded hinge 101 that 
is biased to the closed position of the drawings. The openings 103 through 
the halves 99 are smoothly radiused, as at 105, at their junctions with 
the half faces. Preferably, the snatch blocks are made of a non-metallic 
material. 
Turning back to FIGS. 1-7, the plates 94 are welded to the strips 93 at 
appropriate angles thereto, such that the snatch block openings 103 define 
a smooth continuous path in three dimensions. The path begins at snatch 
block 97a. The axis of opening 103 of the end snatch block 97a is 
approximately parallel to the drum axis 33. The path ends at snatch block 
97e. The axis of the opening of the snatch block 97e is approximately 
perpendicular to the drum axis and is generally aligned with the opening 
in the hooked bail 36. The openings of the intermediate snatch blocks 
97b-97d are arranged to provide a smooth transition between the two end 
snatch block openings. 
In FIGS. 1 and 2, reference numerals 107 represents posts upstandingly 
fixed to the trailer frame 23. Additional similar posts are fixed to the 
frame along the two sides thereof, but for clarity they are not shown. The 
posts 107 are used to hold expanded metal or similar guarding material. 
Pivotally connected to the posts at the back end of the trailer 21 are a 
pair of gates 109. The pivotal connection may be by conventional hinges 
111. The gates 109 have frames made of square tubing or angle iron. 
Expanded metal guarding spans the opening areas between the gate frames. 
Pivotally connected, as by hinges 113, to the free ends of the gates 109 
are respective second gates 115. During transportation of the portable 
storage apparatus, the gates 109 and 115 are folded to a closed 
inoperative configuration against the back end of the trailer, as shown by 
the phantom lines 109' and 115'. 
Mounted to the free end of each gate 115 is one half 117 of a double flared 
guide funnel 119. The funnel halves 117 have flared inner diameters 121. 
Mounting of the guide halves to the gates may be by plates 123. As best 
seen in FIG. 2, the two guide halves are matable to form the enclosed 
guide 119 when the gates 109 and 115 are in the unfolded operative 
configuration. A conventional latch is employed to retain the free ends of 
the gates 115 together and thereby hold the two guide funnel halves in 
place. 
In the preferred embodiment, the portable storage apparatus 1 of the 
present invention includes a hydraulic system for rotating and 
reciprocating the drum 31. The hydraulic system is powered by a 
conventional internal combustion engine located under the support 45 and 
schematically represented as reference numeral 123 in FIG. 6. The engine 
123 drives a conventional hydraulic pump, which forms part of a hydraulic 
power unit 125, as is known in the art. Suitable hydraulic lines lead from 
the hydraulic power unit 125 to the hydraulic motors 40 and 73. 
FIG. 15 shows a schematic diagram of the hydraulic circuitry associated 
with the portable storage apparatus 1 of the present invention. The 
circuitry includes a hydraulic pump 127 driven by the internal combustion 
engine 123 and supplied with hydraulic fluid from a reservoir 129. 
Hydraulic fluid under pressure is pumped to hydraulic motor 73 for 
reciprocating the drum 31 and to hydraulic motors 40 for rotating the 
drum. Directional control valves 131 and 133 are used to reverse the 
direction of rotation and reciprocation, respectively. Valves 135 and 137 
assure proper synchronization between drum rotation and reciprocation. 
OPERATION 
Returning to FIG. 1, the plow 3 moves from left to right. It will be 
assumed that the plow has laid a length of fiber-optic or other flexible 
cable 5 from the supply reel 11 in the trench 15. For the normal cable 
laying operation, the trencher 13 is in an operative position such that it 
engages the earth to dig the trench, and the cable is laid on the trench 
bottom 139. It will further be assumed that an obstacle in the form of a 
road or highway 19 lies in the path of the cable. In accordance with the 
present invention, the plow 3 retracts the trencher 13 to an inoperative 
position, such as is shown in FIG. 1, when the plow is approximately 50 
feet from the road. The plow continues to advance to the edge of the road, 
laying the cable 5 on the surface 9 of the ground. A few feet of slack are 
unwound from the supply reel. 
The portable storage apparatus 1 of the present invention is then towed to 
a location near the plow 3. Preferably, the storage apparatus is parked 
between the plow and the end of the trench 15, with the drum axis 33 
approximately parallel to the slack cable on the ground. The drum 31 is 
rotated under hydraulic power by the rollers 37 and motors 40 until the 
drum slot 38 is in angular alignment with the slots 48 in the housings 46 
and with the slot 42 in the center tube 41. The inner tube 83 is manually 
positioned such that the slot 85 therein is aligned with the center tube 
and drum slots. Referring also to FIGS. 2-7 and 10, the slack cable 5 
laying on the ground is then picked up, starting at the trailer front end. 
The cable is fed transversely through the slots 48 in the housings 46, 
through the slot 42 in the front end 43 of the center tube 41, and through 
the slot 85 in the inner tube, such that the cable is supported inside the 
inner tube. The cable, which has attained a position 5' at the front end 
of the trailer 21, is further fed through the slot 38 in the drum 31, and 
through the center tube and inner tube slots in line with the drum slot, 
such that the cable is supported in the inner tube from the front end 86 
thereof to the drum back end 44. The cable 5' is inserted through the slot 
78 in the reel front flange 82 and the core 80. The cable is further 
pushed through the center tube slot 42 and inner tube slot 85 underlying 
the reel core 80. The inner tube is rotated manually by means of the 
flared end 91 to enable the cable to be inserted through the angular slots 
89, and the short offset slot 85' up to the slot end 96. The lip 88 on the 
wall of the inner tube overlaps the center tube slot 42 and thereby 
prevents the cable inside the inner tube from escaping through the slots 
85 and 42. With the cable inside the inner tube as far as the slot end 96, 
additional cable is pushed through the reel slot 78 to create a large loop 
140 inside the reel inner diameter 90. The cable loop 140 is guided into 
the upper end 141 of the tube 84 fixed to the reel inner diameter. The 
cable loop passes beyond the retainer tube lower end 143. Because there is 
no slot in the reel back flange 95' the cable remains positioned 
permanently through the slot 78 near the back flange 95. The cable may be 
wrapped around the reel core 80 and inserted transversely into the bail 
36. From the bail, the cable is inserted transversely into the snatch 
blocks 97, which are successively opened to receive the cable and then 
closed by means of the spring loaded hinges 101. Finally, the cable is 
positioned within one of the guide funnel halves 117. The gates 109 and 
115 are positioned to bring the funnel halves together to form the guide 
funnel 119, with the cable captured therein. The gates are latched in 
place. 
The internal combustion engine 123 of the portable storage apparatus 1 is 
then started to operate the hydraulic power unit 125. In a first position, 
the control valve 131 will cause the drum 31 to turn in the direction of 
arrow 147 of FIG. 7, thereby winding the cable 5' onto the reel 77 and 
unwinding the cable from the plow supply reel 11. Simultaneously, control 
valve 133 causes the drum to reciprocate along axis 33 to create neat 
layers of cable on the reel 77. The smooth continuous path formed by the 
guide funnel 119, snatch blocks 97, and bail 36 permit winding the cable 
without damage. In that manner, the cable is windable onto the storage 
apparatus of the present invention without having access to either cable 
end. 
Eventually, the entire cable 5 is unwound from the plow supply reel 11 and 
wound onto the storage reel 77. When that has occurred, the plow 3 is 
driven across the road 19 at any safe and convenient location. Meanwhile, 
the trench 15 is completed up to the road by other known equipment. 
Turning now to FIG. 14, the plow 3 is shown in a new location across the 
road 19. A tunnel 149 is bored under the road. The cable free end is 
threaded through the bore 149 and reattached to the plow supply reel 11. 
The storage apparatus hydraulic circuitry is operated to rotate the drum 
in the direction of arrow 151 in FIG. 7, thereby unwinding the cable from 
the reel 77. At the same time, a suitable drive on the plow operates to 
wind the cable back onto the supply reel. When all the cable is unwound 
from the storage reel 77, the cable is pulled transversely out of the 
various slots 42, 38, 48, 85, 85', 89, and 78; bail 36; snatch blocks 97; 
retainer tube 84; and guide funnel 119. The cable is laid within the 
trench 15 up to the road and then wound by the plow supply reel to take up 
the slack. The plow is then able to resume cable laying operations in a 
normal manner. The trailer 21 is towed to the next road or other 
obstruction in the cable path. 
Thus, it is apparent that there has been provided, in accordance with the 
invention, a portable device for storing an endless metallic or 
fiber-optic cable that fully satisfies the aims and advantage set forth 
above. While the invention has been described in conjunction with specific 
embodiments thereof, it is evident that many alternatives, modifications, 
and variations will be apparent to those skilled in the art in light of 
the foregoing description. Accordingly, it is intended to embrace all such 
alternatives, modifications, and variations as fall within the spirit and 
broad scope of the appended claims.