CA1111829A - Wind-up drum for faired cable - Google Patents
Wind-up drum for faired cableInfo
- Publication number
- CA1111829A CA1111829A CA325,652A CA325652A CA1111829A CA 1111829 A CA1111829 A CA 1111829A CA 325652 A CA325652 A CA 325652A CA 1111829 A CA1111829 A CA 1111829A
- Authority
- CA
- Canada
- Prior art keywords
- cable
- drum
- improvement
- towing
- assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
- B66D1/00—Rope, cable, or chain winding mechanisms; Capstans
- B66D1/28—Other constructional details
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Storing, Repeated Paying-Out, And Re-Storing Of Elongated Articles (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improved wind-up main winch drum for the faired cable of a system for launching, towing and recovering a towed body from a towing surface vessel is provided herein. The sys-tem includes a hoist sub-assembly and boom sub-assembly. The hoist sub-assembly includes a main winch drum for storing live turns of the faired towing cable in a single layer in a first direction such faired cable being adapted to be would on and unwound off the main winch drum. The main winch drum includes a slot magazine recessed into the interior thereof at one end thereof for storing dead, unfaired towing cable would in multi-layers in the same first direction therein, and to which fairing can be added. Cable winding mechanism, which may be externally or internally mounted, constitute means for providing electrical continuity from the ship's cable to the conductor cable without the use of brush gear.
An improved wind-up main winch drum for the faired cable of a system for launching, towing and recovering a towed body from a towing surface vessel is provided herein. The sys-tem includes a hoist sub-assembly and boom sub-assembly. The hoist sub-assembly includes a main winch drum for storing live turns of the faired towing cable in a single layer in a first direction such faired cable being adapted to be would on and unwound off the main winch drum. The main winch drum includes a slot magazine recessed into the interior thereof at one end thereof for storing dead, unfaired towing cable would in multi-layers in the same first direction therein, and to which fairing can be added. Cable winding mechanism, which may be externally or internally mounted, constitute means for providing electrical continuity from the ship's cable to the conductor cable without the use of brush gear.
Description
.~
~; This invention relates to an improve~ent in a system for s launching, recovering and towing an underwater towed body, and parti-cularly to such improvements in a towing syste~ where an underwater body is towed behind a vessel. In particular, this invention relates to an $mproved wind-up drum for faired towing cable used in such a system~
The underwater towed body with which the present invention is used is an underwater SONA2 body (abbreviated from "Sound ~7avigation and : Ranging") which is finding ever-increasing use in the fields of naviga-tion, mapping, depth finding, fish finding, for detection of wrecks and in a military use, in the detection of enemy vessels. The system with which the present invention is used is a variable depth system, wherein an underwater sound transducer or array is mounted in a body towed from the vessel.
In a variable depth sonar, particularly as used in military applications, an array (usually cylindrical) of underwater sound trans-ducers is housed within a strea~lined body which is towed from the surface ship via a faired cable. This cable has an internal core of contuctors for transmitting signals to and from the ship from and to the array, and outer layers of armour to withstand towing tensions.
Mounted on the ship i9 means for mechanically launching and retrieving the body, and for shortening and lengthening the amount of cable out.
In the towing system as above described, it is desirable to provide a system whereby the towed body may be readily launched and retrieved and handled during the towing operation, which during such towing mlnimizes damage to the tor~ing cable and object being towed.
It is also desirable to provide a shock absorbing system which would minimize variations of tension in the tow line interconnecting two spaced-apart masses in a body of water, for example, a submerged sonar body towed by a moving ship.
In the realm of towed sonar technology, the launch operation comprises lifting the sonar body from the ship's deck, swinging it o~er the stern until it is largely immersed in the water, then releasing it from the hoist mechanism to stréam aft belo~ the water surface. The recovery operation comprises reeling in of the towed sonar body until it i9 captured in the hoist saddle, then lifting it aboard by operating the hoist.
It has been found, in practice, that the tow cable progres-sively deteriorates in service due to the combined effects of fatigue and corrosion. It has also been found that this deterioration is worst at the attachment point of the towed body to the tow cable. It i5 common practice when this happens to shorten the cable by cutting off a length of the deteriorated end, reterminating it and re-attaching it to the towed body. However, only a few shortenings and reterminations can be made before the cable becomes too short to be serviceable. Accommodating extra cable on the deck handllng equipment to allow a greater number of shortenings is space consuming, further aggravating the problem of shortage of space.
One manner suggested by the prlor art for storing additional cable has been proposed in Canadian Patent No. 50,377 of J. Bell et al dated October 23, 1895, involving the use of a first barrel adapted to have wound upon it, in a single coil, the part of the rope being used, and a second barrel or reel adapted to carry the part of the rope not being used. This construction is, nevertheless, space consuming.
Other proposals have been provided in Canadian Patents No.
973,157 dated August 19, 1975 and No. 978,174 dated November 18, 1975 of Ocean Systems, involving the provision of a storage ch~mber bel~w the deck upon which the win~hes are mounted. This too requires alterations to the stern of existing designs of smal} vessels, which may not be too feasible.
Another suggestion for solving such proble~ has been proposed in Canadian Patent No. 902,577 dated June 13, 1~72 in the name of N.E. Hale. In that patent, the cable drum includes a plurality of con-centric drums with access means for passage of the faired cable between the drums. This provides extra length of faired cable but no excess for unfaired cable.
It i9 recogni~ed that in winch applications, it becomes necessary to reduce the fleet angle in order to obtain a proper laying of ad~acent turns of cable upon the winch drum. For accurate reeling of cable, the cable should approach the drum at right angles which is to say, the fleet angle should be as close to zero as practicable.
Numerous methods of ach~ev~ng a fleet angle as close to zero as practicable exist in mechanisms known as level winders. These in general comprise a travelling guide which moves laterally relative to the cable, i.e. in a direction parallel to the winch drum pivot axis, one pitch (distance between turns) for every revolution of the winch drum and through which the cable must pasq prior to reaching the winch.
Typical examples of movable guide~ for reducing the fleet angle are found in the structures illustrated in Canadian Patents Nos. 692,070 and 707,634 issued, respectively, August 4, 1964 and April 13, 1965.
Another successful means of keeping the fleet angle as close ss possible to zero is taught in Canadian Patent No. 1,005,702. By means of a careful orientation of the winch drum relative to the boom sheave throughout its travel and by means of limiting the width of the winch drums and by mean~ of offsetting the boom assembly between 2 and 3, preferably by 230', the necessity of using any separate spooling apparatus is avoided. Consequently, from the extremes of having the boom fully extended with all csble either in or out, to bringing the boom fully inboard with all cable wound on the drum, the fleet angle is - less than the critical 3 figure. This means that separate cable spool-ing is unnecessary and that the cable will wind onto the winch drum g without further complication.
An ob~ect of a main aspect of this invention is to provide an improved hoist drum assembly which provides means for storing large excesses of faired towing cable for a multiplicity of shortenings and reterminations, required to extend service life.
An ob~ect of another aspect of this invention is to provide such an improved hoist drum assembly which includes a cable winder assembly associated therewith.
An ob~ect of another aspect of this invention is to provide such an improved hoist drum assembly which includes means for controlling the fleet angle of the cable as it is wound thereon.
By one broad aspect of this invention, an improvement is provided in a system for launching, towing and recovering a towed body from a towing surface vessel using faired towing cable, the system including a hoist sub-assembly and a boom sub-assembly, the improvement comprising: a main winch drum in the holst sub-assembly for storing live turns of the faired towing cable wound in a single layer in a first direction, which faired cable is adapted to be wound on and unwound off the ~ain winch drum, the main winch drum including a slot magazine recessed into the interior thereof at one end thereof for storing dead, unfaired towing cable wound in multilayers in the same first direction thereo; the main winch drum including a single cable clamp completely inboard of 811 turns of the faired and unfaired cable and near the inboard end of the cable.
By one variant, the cable includes a conductor secured to the towing surface vessel and extending through the cable.
8;~9 By anothe~ variant, the main winch drum is secured to a rotatable main shaft.
By another variant, the main winch drum is rotatably mounted on a fixed shaft.
By variations thereof, the main drum is driven by a pull gear/
bull pinion arrangement by means of a drive motor, and the bull gear/bull pinion arrangement 8~9 includes a brake assembly.
By another variation, the main drum includes one section containing the slot magazine, and an integral section containing a cable winder mechanism therein.
By another variant, the slot magazine is provided with a plug receptacle and strain-terminating arrangement by means of which towing cable is secured to conductor cable; and the system includes means leading conductor cable out an end of the main winch drum to be connected to an external cable winder to provide electrical continuity from the conductor cable.
By another variant, the slot magazine is provided with a plug receptacle and strain~terminating arrangement by means of which towing cable is secured to conductor cable; and in-cluding means leading conductor cable to a coaxial rotating drum.
By yet another variant, the cable winder mechanism for the conductor cable includes an internal coaxial rotating drum, a stationary storage drum, a counterweighted arm freely swingably mounted on the fixed shaft~ the counterweighted arm including a freely rotatable sheave for engaging the conductor cable for transferring the conductor cable out an end of the coaxial ro-tating drum to a stationary storage drum, the conductor cable being connected with conductor cable in the towing surface vessel to provide electrical continuity without the use of brush gear.
By a variation thereof, the cable winder mechanism is adapted to engage the conductor cable at positions disposed in ~e,l~ o ~
respective overlapping~with respect to the coaxial rotating drum and the stationary storage drum, and movable about the periphery thereof for transferring a portion of the conductor cable portion , ~
8~9 engaged thereby from one drum to the other drum in response d~
to rotational movement of the driven winch dru, such cable winder mechanism (which in one variant is externally mounted, and in ancther variant is internally mounted) being the means for pro-viding electrical continuity from the conducting cable in the towing surface vessel to the conductor cable without the aid of a brush gear.
- 5a -8~9 By another variant, the main winch drum is mounted on a rolling base for linear translation of the hoist sub-assembly, thereby to control the fleet angle of the cable as it is wound onto, and off the main winch drum.
By another variation, the rolling base of the winch sub-assembly is proviaed with wheels for linear translation.
Thus, by an embodiment of this invention, the hoist sub-assembly includes a winch drum with a special annular and radial slot magazine at one end. This annular ~nd radial slot magazine allows for spooling of a large excess of unfaired cable in several layers and takes up no more room than would be required by the normal number of 'dead' turns left on a conventional drum for safety when all the faired cable has been paid out. The dead b- fo~
turns are wound on the slot magazine ~fte~ the line faired turns have been wound on the winch drum. This annular and radical slot magazine allows for a multiplicity of shortenings and reterm~na-tions at the towed body and a significant prolo~-gation of cable service life over that currently obtained. As the cable is shor-tened dead turns may he transferred to active turns without re-lease of either cable load or cable clamp during which filler pieces are introduced into the slot beneath the reduced number of layers.
The uinch drum variant ln the hoist sub-assembly shown in Figure 1 of th~s inventlon (to be described ln greater detail herelnafter) may be put into ~ull use by a person skilled in the art by proper interrelation-ship.with the towing system of Canadian Patent No. 1,005,702 granted February 22, 1977 to Ronyx Corporation or of Canadian Patent No. 1,010, 308 granted May 17, 1977 to Ronyx Corporatlon. The application of the winch variant shown in Figure 1 of this application (to be described in ~ 6 -32~
greater detail hereinafter) to Canadian Patent No. 1,005,702 woult be accomplished by a person skilled in the art by substituting shafts 15 and drum lQ from Figure 1 of this application for stub shafts 27 and winch drum 11 in Figure 4 of Canadian Patent No. 1,005,702. In addition gear 19 in Figure 1 of this application (to be described in greater detail here-inafter) would be replaced by a shaft flange to bolt to motor 15 in Fi~ure 4 of Canadian Patent No. 1,005,702. It may also be used by a person s~illed in the art along with other variations as previously described in the system of Copending application Serial No. 324,215 filed March 27, 1979.
The towing system of the aforesaid Canadian Patent No. 1,005,702 is one in which a variable depth sonar towed body is transferred from an inboard stowed position to an outboard launch position. From its launch position, the towed body can be released and lowered on its towing cable to the re-quired operational depth. This depth is controlled by adjusting tbe length of tow cable paid out by a towing winch and by the speed of the towing ves-sel. On the completion of the towing operations, the body can be recovered by reversal of the launching procedure. In addition to having means for launching, towing, depth changing and recovery operations, the preferred embodiment described includes a shock absorber system that prevents exces-sive variation of the cable tension caused by wave action.
The towing winch assembly provided by Canadian Patent No. 1,005, 702 consists of a winch drum mounted on a base frame which is secured to the aft upper-deck of the ship. The winch drum is driven by a hydraulic motor which incorporates a spring applied-hydraulic release-type band brake. The winch drum drives a conductor winder mounted on one side of the winch drum and which provides electrical continuity from the conductors of the tow cahle to the internal sonar circuits of the ship.
The unction of the winch assembly is to pay out and haul in the desired length of tow cable and to assist the boom and actuator assembly in the launch and recovery of the towed body.
The winch drum variant shown in Figure 1, (to be described in greater detail hereinafter), as i~ may be applied to Canadian Patent No.
1,005,702 may be fabricated from aluminum plate, consisting of an outer shell with a reinforcing web on the inner surface to form a slot magazine and on the ends. The end webs contain openings for allowing access to the electrical conductor cable inside the winch drum. The outer surface of the winch drum is grooved with grooves to accom~odate the required length of faired tow cable in a single layer. Holes are dri]led at intervals 8;~:~
around the perlphery of the winch drum to permit drainage.
The anchor of the tow cable ls clamped within an anchor block which is bolted to the inside face of the slot magazine. Another clamp i5 secured on the inside of the winch drum to a convenient member for holding an electrical connector that is on the end of the conductor cable.
A shaft passes through both end plates of the winch drum. The shaft rotates within bearings, which are mounted in pillow blocks that are secured to the winch frame.
The winch frame is a welded aluminum structure that supports the complete hoist. Suitable surfaces are provided on the winch frame for attachment of the winch bearing assemblies; of the winch motor and band brake assembly; of the boom actuator; of the external conductor winder; and of the gas bottles, linear actuators and sheaves for the shock absorber sys-tem.
The winch drum may be driven through low speed, high torque radial piston type hydraulic motor connected to one end of the shaft. The motor i5 integral with a spring-applied, hydraulic release-type band brake com-plete with mounting bracket.
An external conductor winder is included to provide the means for maintaining electrical continuity between the conductors of the tow cable and the internal sonar circuits of the ship without the use of slip rings.
lt is positioned on one side of the winch drum and is contained within a watertight enclosure, preferably formed of aluminum, which has two inspec-tion windows. The winder consists of a pril~ry drum, a stationary spool and a negator spring assembly.
The winder mechanism consists of an arm attached intermediate the ends thereof to a shaft for rotation in the hub and has a portion pro-jecting beyond the side wall of the spool for the purpose which will become apparent hereinafter. The arm terminates at one end in a bufurcated portion 8~9 having a sheave pivotally secured thereto, for example, by a pin. A plural-ity of counterweights are detachably secured to the opposite end of the arm. The arm, accordingly, rotates about the axis of the shaft which, in turn, is coincident with the axis of the shaft. The sheave is freely ro-tatable about the pin with the axis thereof being perpendicular to the axis of the arm.
The winder mechanism is attached to a negator spring assembly which consists of a spring drum, secured to a portion of a shaft colinear withJ but separate from, the drum shaft which projects through the casing side wall, a coiled band spring and an anchor for the spring. The spring drum is secured to the shaft and wound on the outside thereof is the band spring anchored at one end to the spring drum and the other end is wound around a storage spool, which is pivoted onto a stub shaft secured to the casing side wall. The band spring has a selected length which is coiled onto a storage spool and the stored coil spring resists uncoiling. The outer end of the coiled spirng is attached and coiled in the reverse direc-tion onto the spring drum (work spool). The spring, acting to try to coil itself in one direction onto the storage spool, exerts a relatively con-stant torque in the opposite direction on the work spool. This results in biasing the work spool to rotate in the same direction as the spring torque.
Since the spring drum (work spool) is~secured to the shaft, the winder bar is accordingly spring-biased in the same direction in the work spool. The band spring has preferably substantially constant torque characteristics.
The conductor cable is connected to the tow cable by a plug-re-ceptacle arrangement whi~h is clamped to the inside of the winch drum. -Cable is routed through the drum hub and a shaft collar onto the primary drum of the winder. It then passes over a pulley assembly and onto the stationary spool. From this spool, the cable passes through a stuffing tube in the bottom of the winder enclosure to the internal circuits of the ship. Rotation of the winch drum in either direction causes the cable to ~, _ g _ 2g pass back and forth between the primary drum and the stationary spool via the pulley assembly. The pulley assembly which is counter-balanced at one end by a weight is connected to the negator spring assemb~y. This spring assembly maintains the pulley assembly spr;ng biased, thereby maintaining a normal tension in the conductor cable at all times.
The operation of the winder mechanism may be described as follows:
The winch drum is appropriately rotated to wind in and pay out cable. When the tow cable is stored on the winch drum, that is, in a wound-in position, the majority of the multi-conductor cable extending beyond the winch drum is stored on the stationary spool. As the winch drum is rotated to pay out the cable, primary drum rotates in unison with the drum causing the cable to be wrapped, turn by turn, on the primary drum Since the supply of the cable is on the non-rotatable stationary spool, the resulting pull on the cable causes a turning movement to act on the winder bar mechanism. This turning force in consequence causes the bar to rotate in the same direction as the wiDch drum against the bias of the spring. As the winder bar rotates, it pulls the cable off the ststionary drum and this effectively transfers the cable from the primary drum to the rotary storate drum. The bias of the spring prevents slack cable from developing and thus the cable removed from the staticnary spool wi]l travel over the sheave and will wrap onto the drum because of the bar rotating at a slower speed than the drum. The speed of rotatiGn of the winder bar should be just sufficient as to main-tain tension in the continuity cable and it will find its own speed since it will be dragged around by the pull on the multi core conductor cable.
The above operating description is based on the case of the ~
winch paying out cable. W~ten ~he winch is reeling cable in, the conductor cable winder performs the same function except that the spring bias takes up the slack of cable removed from the drum and transfers it to another-drum.
~70 bearings are mounted on the winch frame such that each bearing has a small clearance with the side edges of the port and starboard winch dr~m end plates. The purpose of these bearings is to distribute side shock loads from the winch drum into the winch frame.
Two boom stops are mounted on the winch frame to stop and support the boom in the inboard stowed position. Each stop in one embodiment there-of consistS of an aluminum weldment fitted with an elastomeric rubber bumper pad. A lower body stop is mounted on the winch frame to support the forward portion of the towed body from underneath when in the inboard stowed posi-tion. It consists, in one embodiment thereof, of an aluminum weldment fit-ted with an elastomeric rubber bumper pad.
The boom assembly includes a boom which is fabricated of arms con-sisting of aluminum beams and plates rigidly bolted together with a cross brace to form an "H" configuration. Two pillow blocks, preferably made of steel, are bolted to inboard ends of the boom arms and are then keyed to the stub shafts of the actuator. Rotary actuator is mounted on the base frame of the towing winch assembly.
The purpose of the boom and actuator assembly is to transfer the towed body from the inboard stowed position to the outboard launch position and vice versa, with the aid of the winch assembly.
The boom is moved from the inboard stowed position to the out-board launch position and vice versa by a rotary actuator, which preferably is a hydraulic rotary actuator. The actuator is secured to the underside of that part of t~e winch frame that overhangs the stern of the ship.
Secured transversely across the boom arms is an H-shaped beam stop ~ember. When the boom is in its outboard launched position, stop mem-ber engages rubber bumpers, secured to the stern of the ship.
The saddlelcable guidelsheave assembly is carried on a horizontal shaft which is supported at the outboard extremities of the lifting boom.
The saddle provides a stable seating for the towed sonar body during launch-ing and recovery, and is malntained in a near horizontal attitude by means 8~9 of a levelling mechanism. It also affords protection to the towed body by means of bumpers, preferably formed of polyurethane, mounted on its underside. The cable guide assembly includes a cluster of side guide rol-lers against which the tow cable bears during towing operations. To com-pensate for the various tow cable angles, the guide is made spring-biased using two laminated band springs in a direction such that the rollers will always be at right angles to the tow cable.
The sheave shaft consists preferably of a chrome plated steel tube secured to the outboard ends of the boom arms. Sheave shaft supports the sheave, saddle assembly and cable guide assembly.
The sheave is an aluminum structure which freely rotates on the sheave shaft on bearings, preferably fabric-reinforced phenolic bearings. It is made up of a weldment to which are bolted two rims which form the groove of the sheave. In this groove are located a plurality, e.g., eight, arcuate segments of a plastics material, e.g., polyurethane material, which serve to protect the nose pieces of the fairings of the tow cable. A grease nipple is readily accessible for lubrication of the bearings~ !
The saddle assembly is a welded structure made of aluminum plates whose purpose is to provide a stable seating for the towed body dur-ing launching and recovery. The assembly is supported on the sheave shaft in bearings, preferably fibre-reinforced phenolic bearings. ~ grease nip-ple is readily accessible on each bearing for lubrication.
A plurality, e.g., eight, semi-spherical bumpers, preferably of polyurethane, are bolted to the underside of the assembly. They are posi-tioned to conform with the upper curvature sf the towed body and afford protection to the body during launching and recovery operations.
The design of cable guide effectively eliminates the need of hav-ing long side rollers extending aft sufficient to accommodate the various . .
8~9 tow cable angles. The cable guide assembly consists of two w~lded aluminum arms each supported at one end of the sheave shaft in bearings, preferably flbre-reinforced phenolic bearings. A grease nipple is readily accessible on each bearing for lubrication. The assembly is cross-connected at the other end of each arm with three spacer tubes. On two of the tubes are mounted freely rotating rollers, preferably fibre-reinforced phenolic rol-lers, one roller being forward of the tow cable and the other being aft.
Similar rollers are mounted on the side of each arm so that tow cable passes through the middle of the cluster of rollers. The cable guide assembly is connected to the saddle assembly by two constant torque band springs. These spring make the cable guide spring biased in a direction such that the for-ward roller always bears against the nose pieces of the fairings of the tow cable regardless of tow cable angle.
The saddle assembly is maintained in a horizontal attitude at all boom positions by a levelling assembly. Such assembly consists of two sets of two pulleys, one set being located on the port side, the other set being located on the starboard side. One pulley of each set is secured to the housing of the boom actuator and the other pulley of each set is on the saddle assembly. Each set of pulleys is connected by a cable, preferably a stainless steel cable that is fixed to each pulley by clamp pins.
The shock absorber system consists of two identical sets of com-ponents, one set being located on the port side of the winch frame, the other set being located on the starboard side. Each set consists of a spring return-type linear actuator which is hinged at its head end by hinge pins to the extreme forward side of the winch frame. The rod end only of each actuator is charged with a compressible fluid, e.g., a gas, for exam-ple, nitrogen gas, from a supply of two gas bottles which are mounted on the forward end of the winch frame. The gas pressure in the actuators can easily be changed by manipulating two valves on the hydraulic power unit.
The piston rod of the actuator is connected to a length of cable, which passes over a freely rotating pulley mounted on the winch frame. The cable is then connected to a torque arm that is secured to the boom assembly hinge point.
A body rest is attached to the boom in such a way that the towed body comes automatically to a seating in this body rest, when the boom ar-rives at its most inboard position. The body rest might support the body fully or only partially, in which case a supplementary deck-mounted support will coexist.
The towing system is hydrualically ~ctuated, the system being manually and electrically controlled from a hydraulic power unit. A feature thereof is that during launch and recovery operations the towed body is held firmly in the saddle by tension in the tow cable. This tension is maintained near constant by a pressure compensated, closed loop, hydrostatic drive system.
Movement of the boom about its mean hinge point during towing operations will cause, depending upon the magnltude of the cable load, a compression or expansion of the gas and the springs within the actuator.
This compression or expansion will only be sufficient to set up a moment on the boom to counteract the moment caused by the cable load. During tow-ing operations, the boom is positioned at an angle of 0~ and the gas pres-sure in the actuators is sdjusted so that with a steady cable pull the boom remains relatively still. If the cable pull increases, the boom will drop down and the gas and springs within the actuators will be compressed. The boom will drop only that amount that the moment on the boom due to the actuators will increase sufficiently to counteract the m~ment caused by the increased cable pull. If the cable pull decreases the boom will rise and the gas and springs will expand. Again the boom will rise only that amount that the moment on the boom due to the actuators will decrease sufficiently to counteract the moment caused by the decreased cable pull.
A hydraulic power unit is provided to operate the system. It includes a variable displacement axial piston pump system having both manual and pressur~ compensation controls. A closed loop, including a double shaft electric motor and pump, provides a hydrostatic drive system that drives the winch motor at variable speed and in both directions.
Also included in the hydraulic power unit is a fixed displacement tandem gear pump. One outlet of the pump supplies oil, filtered through filter to the boom circuit; the other outlet supplies oil, filtered through filter, for release of the winch brake and for the swash controls of the variable displacement pump.
The above components together with several valves are mounted on a reservoir. The reservoir, in one of its em~odiments, is a welded alumin-um structure provided with the usual gear, e.g., clean-out covers, a filler-breather cap, an oil level gauge and a drain valve. It is also pro-vided wi th oil strainers to protect the pump from contamination.
The winch assembly is driven by a low speed, high torque, radial piston hydraulic motor which is of the rotating housing type. The band brake which is spring applied and hydraulically released by a linear actua-tor acts on the outer surface of the motor housing. The motor, band brake and actuator are mounted on a common base.
The boom is preferably moved by a hydraulic, double vane-type, rotary actuator, which has a maximum angular travel of 155D.
It should be recognized that the preceeding description commencing on pa~e 6 herein is concerned solely with the description of Canadian Patent No. 1,005,702 when outfitted with a drum variant as shown in Figure 1 of the present application but with a direct drive, that is, with gear 19 replaced with a motor direct coupled to shaft 15. While other variants as shown in Figures 2 - 5 of the present application (to be described hereinafter) could also be adapted for use with Canadian Patent No. 1, 005,702, this could entail alterations in the mechanical interre~ationship, adaptable by a person skilled in this art.
~- 16 -In the accompanying drawings, Figure 1 is a central vertical cross-section of the cable wind-up winch drum of one aspect of this invention;
Figure 2 is a central vertical cross-section of the cable wind-up winch drum of another aspect of this invention;
Figure 3 is a central vertical cross-section of the cable wind-up winch drum of the aspect of Figure 2 and includes one aspect of a drive and a stationary base;
Figure 4 is a side elevation of the cable wind-up drum of the as-pect of Figure 2 including one aspect of a dri~e and a wheeled base; and Figure 5 is an end elevation of the hoist of Figure 4.
The cable wind-up winch drum, which may used in the system des-cribed above in Canadian Patent No. 1.005,702 is, as seen in Figure 1, the main drum 10 includes a pair of spaced-apart circular exterior housing plates 11, 12 connected between a hollow cylindrical core 13 and an outer cylindrical wall 14. The drum 10 is secured to a central shaft 15 which is mounted for rotation in spaced-apart bearings 16 secured within spaced-apart pedestal supports 17 mounted on the deck 18. The main drum is provided with a bull. gear 19 secured to plate 12 and bull gear 19 is adapted to be driven by a gear and motor ~not shown). While a bull gear drive i.s shown, the drum 10 may also be driven by other gearing arrangements connected to the rotating shaft 15, or may be direct driven by a motor. The outer cylin-drical wlal 14 is provided with a plurality of grooves 21 adapted to accomo-~.,, - 16 a -date the cable 22 provided wlth fairings 23.
By a main embodiment of the present invention, an annular, radial slot magazine 24 is provided ad~acent plate 12. This radial slot magazine 24 i~ shown fllled with unfaired cable 22. The bottom cylindrical plate 25 : is provided with a plug receptacle and strain termination arrangement 26 through whichconductor cable 27 is led. The conductor cable 27 is led out an aperture 28 in the plate 11 and through an aligned aperture 29 in an enlarged, flanged bearing journal of shaft 15. The end of the cable is led to an external cable winder 30. Cable winder 30 is fully described in Canadian Patent No. 856,639 issued November 6, 1970. Since the cable winder does not form an essential part of the present invention, it will not be described further. The cable winder, which may be of any well-known structure, provides elec.rical continuity from the conductors (not shown) of the tow cable 22 to the internal sonar circuits (not shown) of the ship.
The function of the winch drum 10 is to pay out and haul in the desired length of the tow cable 22, and to assist the boom and actuator assembly in the launch and recovery of the towed body. It is seen that the radial 810t magazine 24 allows for the spooling of a large excess of un-faired cable 22 in several layers. This takes up no more room than would be required by the number of 'dead' turns, normally left as a ssfety mar-gin on a conventional drum when all the faired cable has been paid out. As the cable 22 is used up due to shortening and retermination of the cable, filler pieces (not shown) are introduced into the radial slot magazine 24 beneath the reduced number of layers of unfaired cable.
As seen in ~igures 2 and 3, the main drum 40 includes an exterior housing plate 42 and an internal housing plate 41 connected between a hollow cylindrical spacer tube 43. The drum 40 is supported on spaced-apart drum bearings 46 mounted centrally within plates 41, 42. The bearings 46 are adapted to rotate on stationary shaft 4~ ~hose ends are secured 1.8~
within spaced-apart pedestal supports 47 mounted on the deck 48.
The drum 40 is provided with an outer cylindrical wall 44, pro-vided wirh a plurality of grooves 51 adapted to accommodate the cable 22 provided with fairings 23. The fairings 23 as shown are fairing elements ; comprising a rigid body member having opposed ends providing abutting sur-face of ad~acently disposed fairing elements located in end-to-end align-ment, Outer cylindrical wall 44 extends beyond the edge of plate 42 to terminate in an annular rim plate 52. A fixed external housing support plate 53 is secured around stationary shaft 45. Sliding connection between rim plate 52 and the rim 54 of housing support plate 53 is by means of sealed flange 55.
In this embodiment of the invention as shown in Figures 2 and 3, a radial slot magazine 64 is provided against plate 42. The radial slot magazine 64 is shown filled with unfaired cable 22. The bottom cylindri-cal plate 65 is provided with a plug receptacle and strain termination arrangement 66 through which conductor cable 27 is led. The conductor cable 27 is led through aperture 68 in plate 41. The end of the conductor cable 27 is then led to the bottom cylindrical surface 69 of a rotating conductor cable drum 70. The conductor cable 27 ls wound on durm 70 by means of a winder mechanism to be described later. The main drum 40 is 20 rotated by means of a bull gear 48a mounted on plate 42. The precise means of drlving bull gear 48a is not shown ln Figure 2, but, as shown in Figure 3, the drive means comprises a drive or bull pinion 71 connected to a drive motor and brake assembly 72. In addition, as seen in Figure 3, one of the pedestal supports 47 is replaced by a combined shaft and drive shpport 73. The durm 40 is shown mounted on a plain base 74.
A preferred form of cable winder mechanism for the conductor cable 27 is shown in Fi~ures 2 and 3. The cable ~7inder mechanism provides A the means for maintaining electrical continuity between the conductors of the tow cable 22 and the internal sonar circuits of the ship without the use of the slip rings. As shown in Figures 2 and 3, the cable winder mechanism includes an arm 75 attached intermediate its ends to shaft 45 for rotation about a hub 76. Arm 75 terminates at one end in a bufurcated por-: tion 78 having a sheave 79 pivotally secured thereto by a pin 80. Theopposite end of the arm 75 is provided with detachable counterweights 77.
AccordiDgly, arm 75 is adapted to pivot about the axis of shaft 45. The sheave 79 is freely rotatable about pin 80, with the axis theraof being perpendicular to the axes of the arm 75.
The winder mechanism is attached via torque tube 100 to a NEGATOR
(registered Trade Mark) spring assembly 82 which consists of a coiled band spring 84 and an anchor 85 on torque tube 100 for the band spring 84. The band spring 84 has a selected length which is coiled onto a storage spool 101, and the stored coil band spring 84 resists uncoiling. The coiled band spring 84, acting to try to uncoil itself biases the bar 75 in an opposite direction. The band spring 84 preferably has substantially con-stant torque characteristics.
As noted before, the conductor cable 27 is routed onto the rotat-ing drum 70. It then passes over the sheave assembly 79 and onto the stationary drum 83. From this drum 83, the cable 27 passes through a stuf-fing tube to the internal circuits of the ship. Rotation of the winch drum 40 in either direction causes the conductor cable 27 to pass back and forth between the rotating drum 70 and the stationary drum 83 via the sheave a~sembly 79. The sheave assembly 79 which is counter-balanced at one end by a weight 77 is connected to the NEGATOR spring assembly 82.
This spring assembly 82 maintains the sheave assembly 79 spring biased, thereby maintained a nominal tension the conductor cable 27 at all times.
From drum 83, the conductor cable 27 is led out the end of the plate 53 through stuffing tube 81 and may be connected to an external cable winder, e.g., that described in Canadian Patent No. 856,639.
,' -- 19 --8~9 As seen in Figureg 4 and 5, the base 90 of the hoist assembly on whlch the shaft support 47 is moutned is provided with a plurality of rol-lers 91, and a transverse plurality of rollers 93. These rollers run in a base track 92.
The base 90 is thus shown with wheels for linear translation of the entire hoist to control fleet angle of the cable as it is wound on an off the drum. The ~ranslating de~ice and drive is not shown; it may be a hydraulic cylinder, a screw, or other means. However, the base may also be plain and fixed to the ship's deck. It may also have wheels and a kingpin for angular translation as described in Canadian Patent No. 855, 578. There may also be no base at all; the shaft supports may be bolted directly to a reinforced deck.
- 19 a -
~; This invention relates to an improve~ent in a system for s launching, recovering and towing an underwater towed body, and parti-cularly to such improvements in a towing syste~ where an underwater body is towed behind a vessel. In particular, this invention relates to an $mproved wind-up drum for faired towing cable used in such a system~
The underwater towed body with which the present invention is used is an underwater SONA2 body (abbreviated from "Sound ~7avigation and : Ranging") which is finding ever-increasing use in the fields of naviga-tion, mapping, depth finding, fish finding, for detection of wrecks and in a military use, in the detection of enemy vessels. The system with which the present invention is used is a variable depth system, wherein an underwater sound transducer or array is mounted in a body towed from the vessel.
In a variable depth sonar, particularly as used in military applications, an array (usually cylindrical) of underwater sound trans-ducers is housed within a strea~lined body which is towed from the surface ship via a faired cable. This cable has an internal core of contuctors for transmitting signals to and from the ship from and to the array, and outer layers of armour to withstand towing tensions.
Mounted on the ship i9 means for mechanically launching and retrieving the body, and for shortening and lengthening the amount of cable out.
In the towing system as above described, it is desirable to provide a system whereby the towed body may be readily launched and retrieved and handled during the towing operation, which during such towing mlnimizes damage to the tor~ing cable and object being towed.
It is also desirable to provide a shock absorbing system which would minimize variations of tension in the tow line interconnecting two spaced-apart masses in a body of water, for example, a submerged sonar body towed by a moving ship.
In the realm of towed sonar technology, the launch operation comprises lifting the sonar body from the ship's deck, swinging it o~er the stern until it is largely immersed in the water, then releasing it from the hoist mechanism to stréam aft belo~ the water surface. The recovery operation comprises reeling in of the towed sonar body until it i9 captured in the hoist saddle, then lifting it aboard by operating the hoist.
It has been found, in practice, that the tow cable progres-sively deteriorates in service due to the combined effects of fatigue and corrosion. It has also been found that this deterioration is worst at the attachment point of the towed body to the tow cable. It i5 common practice when this happens to shorten the cable by cutting off a length of the deteriorated end, reterminating it and re-attaching it to the towed body. However, only a few shortenings and reterminations can be made before the cable becomes too short to be serviceable. Accommodating extra cable on the deck handllng equipment to allow a greater number of shortenings is space consuming, further aggravating the problem of shortage of space.
One manner suggested by the prlor art for storing additional cable has been proposed in Canadian Patent No. 50,377 of J. Bell et al dated October 23, 1895, involving the use of a first barrel adapted to have wound upon it, in a single coil, the part of the rope being used, and a second barrel or reel adapted to carry the part of the rope not being used. This construction is, nevertheless, space consuming.
Other proposals have been provided in Canadian Patents No.
973,157 dated August 19, 1975 and No. 978,174 dated November 18, 1975 of Ocean Systems, involving the provision of a storage ch~mber bel~w the deck upon which the win~hes are mounted. This too requires alterations to the stern of existing designs of smal} vessels, which may not be too feasible.
Another suggestion for solving such proble~ has been proposed in Canadian Patent No. 902,577 dated June 13, 1~72 in the name of N.E. Hale. In that patent, the cable drum includes a plurality of con-centric drums with access means for passage of the faired cable between the drums. This provides extra length of faired cable but no excess for unfaired cable.
It i9 recogni~ed that in winch applications, it becomes necessary to reduce the fleet angle in order to obtain a proper laying of ad~acent turns of cable upon the winch drum. For accurate reeling of cable, the cable should approach the drum at right angles which is to say, the fleet angle should be as close to zero as practicable.
Numerous methods of ach~ev~ng a fleet angle as close to zero as practicable exist in mechanisms known as level winders. These in general comprise a travelling guide which moves laterally relative to the cable, i.e. in a direction parallel to the winch drum pivot axis, one pitch (distance between turns) for every revolution of the winch drum and through which the cable must pasq prior to reaching the winch.
Typical examples of movable guide~ for reducing the fleet angle are found in the structures illustrated in Canadian Patents Nos. 692,070 and 707,634 issued, respectively, August 4, 1964 and April 13, 1965.
Another successful means of keeping the fleet angle as close ss possible to zero is taught in Canadian Patent No. 1,005,702. By means of a careful orientation of the winch drum relative to the boom sheave throughout its travel and by means of limiting the width of the winch drums and by mean~ of offsetting the boom assembly between 2 and 3, preferably by 230', the necessity of using any separate spooling apparatus is avoided. Consequently, from the extremes of having the boom fully extended with all csble either in or out, to bringing the boom fully inboard with all cable wound on the drum, the fleet angle is - less than the critical 3 figure. This means that separate cable spool-ing is unnecessary and that the cable will wind onto the winch drum g without further complication.
An ob~ect of a main aspect of this invention is to provide an improved hoist drum assembly which provides means for storing large excesses of faired towing cable for a multiplicity of shortenings and reterminations, required to extend service life.
An ob~ect of another aspect of this invention is to provide such an improved hoist drum assembly which includes a cable winder assembly associated therewith.
An ob~ect of another aspect of this invention is to provide such an improved hoist drum assembly which includes means for controlling the fleet angle of the cable as it is wound thereon.
By one broad aspect of this invention, an improvement is provided in a system for launching, towing and recovering a towed body from a towing surface vessel using faired towing cable, the system including a hoist sub-assembly and a boom sub-assembly, the improvement comprising: a main winch drum in the holst sub-assembly for storing live turns of the faired towing cable wound in a single layer in a first direction, which faired cable is adapted to be wound on and unwound off the ~ain winch drum, the main winch drum including a slot magazine recessed into the interior thereof at one end thereof for storing dead, unfaired towing cable wound in multilayers in the same first direction thereo; the main winch drum including a single cable clamp completely inboard of 811 turns of the faired and unfaired cable and near the inboard end of the cable.
By one variant, the cable includes a conductor secured to the towing surface vessel and extending through the cable.
8;~9 By anothe~ variant, the main winch drum is secured to a rotatable main shaft.
By another variant, the main winch drum is rotatably mounted on a fixed shaft.
By variations thereof, the main drum is driven by a pull gear/
bull pinion arrangement by means of a drive motor, and the bull gear/bull pinion arrangement 8~9 includes a brake assembly.
By another variation, the main drum includes one section containing the slot magazine, and an integral section containing a cable winder mechanism therein.
By another variant, the slot magazine is provided with a plug receptacle and strain-terminating arrangement by means of which towing cable is secured to conductor cable; and the system includes means leading conductor cable out an end of the main winch drum to be connected to an external cable winder to provide electrical continuity from the conductor cable.
By another variant, the slot magazine is provided with a plug receptacle and strain~terminating arrangement by means of which towing cable is secured to conductor cable; and in-cluding means leading conductor cable to a coaxial rotating drum.
By yet another variant, the cable winder mechanism for the conductor cable includes an internal coaxial rotating drum, a stationary storage drum, a counterweighted arm freely swingably mounted on the fixed shaft~ the counterweighted arm including a freely rotatable sheave for engaging the conductor cable for transferring the conductor cable out an end of the coaxial ro-tating drum to a stationary storage drum, the conductor cable being connected with conductor cable in the towing surface vessel to provide electrical continuity without the use of brush gear.
By a variation thereof, the cable winder mechanism is adapted to engage the conductor cable at positions disposed in ~e,l~ o ~
respective overlapping~with respect to the coaxial rotating drum and the stationary storage drum, and movable about the periphery thereof for transferring a portion of the conductor cable portion , ~
8~9 engaged thereby from one drum to the other drum in response d~
to rotational movement of the driven winch dru, such cable winder mechanism (which in one variant is externally mounted, and in ancther variant is internally mounted) being the means for pro-viding electrical continuity from the conducting cable in the towing surface vessel to the conductor cable without the aid of a brush gear.
- 5a -8~9 By another variant, the main winch drum is mounted on a rolling base for linear translation of the hoist sub-assembly, thereby to control the fleet angle of the cable as it is wound onto, and off the main winch drum.
By another variation, the rolling base of the winch sub-assembly is proviaed with wheels for linear translation.
Thus, by an embodiment of this invention, the hoist sub-assembly includes a winch drum with a special annular and radial slot magazine at one end. This annular ~nd radial slot magazine allows for spooling of a large excess of unfaired cable in several layers and takes up no more room than would be required by the normal number of 'dead' turns left on a conventional drum for safety when all the faired cable has been paid out. The dead b- fo~
turns are wound on the slot magazine ~fte~ the line faired turns have been wound on the winch drum. This annular and radical slot magazine allows for a multiplicity of shortenings and reterm~na-tions at the towed body and a significant prolo~-gation of cable service life over that currently obtained. As the cable is shor-tened dead turns may he transferred to active turns without re-lease of either cable load or cable clamp during which filler pieces are introduced into the slot beneath the reduced number of layers.
The uinch drum variant ln the hoist sub-assembly shown in Figure 1 of th~s inventlon (to be described ln greater detail herelnafter) may be put into ~ull use by a person skilled in the art by proper interrelation-ship.with the towing system of Canadian Patent No. 1,005,702 granted February 22, 1977 to Ronyx Corporation or of Canadian Patent No. 1,010, 308 granted May 17, 1977 to Ronyx Corporatlon. The application of the winch variant shown in Figure 1 of this application (to be described in ~ 6 -32~
greater detail hereinafter) to Canadian Patent No. 1,005,702 woult be accomplished by a person skilled in the art by substituting shafts 15 and drum lQ from Figure 1 of this application for stub shafts 27 and winch drum 11 in Figure 4 of Canadian Patent No. 1,005,702. In addition gear 19 in Figure 1 of this application (to be described in greater detail here-inafter) would be replaced by a shaft flange to bolt to motor 15 in Fi~ure 4 of Canadian Patent No. 1,005,702. It may also be used by a person s~illed in the art along with other variations as previously described in the system of Copending application Serial No. 324,215 filed March 27, 1979.
The towing system of the aforesaid Canadian Patent No. 1,005,702 is one in which a variable depth sonar towed body is transferred from an inboard stowed position to an outboard launch position. From its launch position, the towed body can be released and lowered on its towing cable to the re-quired operational depth. This depth is controlled by adjusting tbe length of tow cable paid out by a towing winch and by the speed of the towing ves-sel. On the completion of the towing operations, the body can be recovered by reversal of the launching procedure. In addition to having means for launching, towing, depth changing and recovery operations, the preferred embodiment described includes a shock absorber system that prevents exces-sive variation of the cable tension caused by wave action.
The towing winch assembly provided by Canadian Patent No. 1,005, 702 consists of a winch drum mounted on a base frame which is secured to the aft upper-deck of the ship. The winch drum is driven by a hydraulic motor which incorporates a spring applied-hydraulic release-type band brake. The winch drum drives a conductor winder mounted on one side of the winch drum and which provides electrical continuity from the conductors of the tow cahle to the internal sonar circuits of the ship.
The unction of the winch assembly is to pay out and haul in the desired length of tow cable and to assist the boom and actuator assembly in the launch and recovery of the towed body.
The winch drum variant shown in Figure 1, (to be described in greater detail hereinafter), as i~ may be applied to Canadian Patent No.
1,005,702 may be fabricated from aluminum plate, consisting of an outer shell with a reinforcing web on the inner surface to form a slot magazine and on the ends. The end webs contain openings for allowing access to the electrical conductor cable inside the winch drum. The outer surface of the winch drum is grooved with grooves to accom~odate the required length of faired tow cable in a single layer. Holes are dri]led at intervals 8;~:~
around the perlphery of the winch drum to permit drainage.
The anchor of the tow cable ls clamped within an anchor block which is bolted to the inside face of the slot magazine. Another clamp i5 secured on the inside of the winch drum to a convenient member for holding an electrical connector that is on the end of the conductor cable.
A shaft passes through both end plates of the winch drum. The shaft rotates within bearings, which are mounted in pillow blocks that are secured to the winch frame.
The winch frame is a welded aluminum structure that supports the complete hoist. Suitable surfaces are provided on the winch frame for attachment of the winch bearing assemblies; of the winch motor and band brake assembly; of the boom actuator; of the external conductor winder; and of the gas bottles, linear actuators and sheaves for the shock absorber sys-tem.
The winch drum may be driven through low speed, high torque radial piston type hydraulic motor connected to one end of the shaft. The motor i5 integral with a spring-applied, hydraulic release-type band brake com-plete with mounting bracket.
An external conductor winder is included to provide the means for maintaining electrical continuity between the conductors of the tow cable and the internal sonar circuits of the ship without the use of slip rings.
lt is positioned on one side of the winch drum and is contained within a watertight enclosure, preferably formed of aluminum, which has two inspec-tion windows. The winder consists of a pril~ry drum, a stationary spool and a negator spring assembly.
The winder mechanism consists of an arm attached intermediate the ends thereof to a shaft for rotation in the hub and has a portion pro-jecting beyond the side wall of the spool for the purpose which will become apparent hereinafter. The arm terminates at one end in a bufurcated portion 8~9 having a sheave pivotally secured thereto, for example, by a pin. A plural-ity of counterweights are detachably secured to the opposite end of the arm. The arm, accordingly, rotates about the axis of the shaft which, in turn, is coincident with the axis of the shaft. The sheave is freely ro-tatable about the pin with the axis thereof being perpendicular to the axis of the arm.
The winder mechanism is attached to a negator spring assembly which consists of a spring drum, secured to a portion of a shaft colinear withJ but separate from, the drum shaft which projects through the casing side wall, a coiled band spring and an anchor for the spring. The spring drum is secured to the shaft and wound on the outside thereof is the band spring anchored at one end to the spring drum and the other end is wound around a storage spool, which is pivoted onto a stub shaft secured to the casing side wall. The band spring has a selected length which is coiled onto a storage spool and the stored coil spring resists uncoiling. The outer end of the coiled spirng is attached and coiled in the reverse direc-tion onto the spring drum (work spool). The spring, acting to try to coil itself in one direction onto the storage spool, exerts a relatively con-stant torque in the opposite direction on the work spool. This results in biasing the work spool to rotate in the same direction as the spring torque.
Since the spring drum (work spool) is~secured to the shaft, the winder bar is accordingly spring-biased in the same direction in the work spool. The band spring has preferably substantially constant torque characteristics.
The conductor cable is connected to the tow cable by a plug-re-ceptacle arrangement whi~h is clamped to the inside of the winch drum. -Cable is routed through the drum hub and a shaft collar onto the primary drum of the winder. It then passes over a pulley assembly and onto the stationary spool. From this spool, the cable passes through a stuffing tube in the bottom of the winder enclosure to the internal circuits of the ship. Rotation of the winch drum in either direction causes the cable to ~, _ g _ 2g pass back and forth between the primary drum and the stationary spool via the pulley assembly. The pulley assembly which is counter-balanced at one end by a weight is connected to the negator spring assemb~y. This spring assembly maintains the pulley assembly spr;ng biased, thereby maintaining a normal tension in the conductor cable at all times.
The operation of the winder mechanism may be described as follows:
The winch drum is appropriately rotated to wind in and pay out cable. When the tow cable is stored on the winch drum, that is, in a wound-in position, the majority of the multi-conductor cable extending beyond the winch drum is stored on the stationary spool. As the winch drum is rotated to pay out the cable, primary drum rotates in unison with the drum causing the cable to be wrapped, turn by turn, on the primary drum Since the supply of the cable is on the non-rotatable stationary spool, the resulting pull on the cable causes a turning movement to act on the winder bar mechanism. This turning force in consequence causes the bar to rotate in the same direction as the wiDch drum against the bias of the spring. As the winder bar rotates, it pulls the cable off the ststionary drum and this effectively transfers the cable from the primary drum to the rotary storate drum. The bias of the spring prevents slack cable from developing and thus the cable removed from the staticnary spool wi]l travel over the sheave and will wrap onto the drum because of the bar rotating at a slower speed than the drum. The speed of rotatiGn of the winder bar should be just sufficient as to main-tain tension in the continuity cable and it will find its own speed since it will be dragged around by the pull on the multi core conductor cable.
The above operating description is based on the case of the ~
winch paying out cable. W~ten ~he winch is reeling cable in, the conductor cable winder performs the same function except that the spring bias takes up the slack of cable removed from the drum and transfers it to another-drum.
~70 bearings are mounted on the winch frame such that each bearing has a small clearance with the side edges of the port and starboard winch dr~m end plates. The purpose of these bearings is to distribute side shock loads from the winch drum into the winch frame.
Two boom stops are mounted on the winch frame to stop and support the boom in the inboard stowed position. Each stop in one embodiment there-of consistS of an aluminum weldment fitted with an elastomeric rubber bumper pad. A lower body stop is mounted on the winch frame to support the forward portion of the towed body from underneath when in the inboard stowed posi-tion. It consists, in one embodiment thereof, of an aluminum weldment fit-ted with an elastomeric rubber bumper pad.
The boom assembly includes a boom which is fabricated of arms con-sisting of aluminum beams and plates rigidly bolted together with a cross brace to form an "H" configuration. Two pillow blocks, preferably made of steel, are bolted to inboard ends of the boom arms and are then keyed to the stub shafts of the actuator. Rotary actuator is mounted on the base frame of the towing winch assembly.
The purpose of the boom and actuator assembly is to transfer the towed body from the inboard stowed position to the outboard launch position and vice versa, with the aid of the winch assembly.
The boom is moved from the inboard stowed position to the out-board launch position and vice versa by a rotary actuator, which preferably is a hydraulic rotary actuator. The actuator is secured to the underside of that part of t~e winch frame that overhangs the stern of the ship.
Secured transversely across the boom arms is an H-shaped beam stop ~ember. When the boom is in its outboard launched position, stop mem-ber engages rubber bumpers, secured to the stern of the ship.
The saddlelcable guidelsheave assembly is carried on a horizontal shaft which is supported at the outboard extremities of the lifting boom.
The saddle provides a stable seating for the towed sonar body during launch-ing and recovery, and is malntained in a near horizontal attitude by means 8~9 of a levelling mechanism. It also affords protection to the towed body by means of bumpers, preferably formed of polyurethane, mounted on its underside. The cable guide assembly includes a cluster of side guide rol-lers against which the tow cable bears during towing operations. To com-pensate for the various tow cable angles, the guide is made spring-biased using two laminated band springs in a direction such that the rollers will always be at right angles to the tow cable.
The sheave shaft consists preferably of a chrome plated steel tube secured to the outboard ends of the boom arms. Sheave shaft supports the sheave, saddle assembly and cable guide assembly.
The sheave is an aluminum structure which freely rotates on the sheave shaft on bearings, preferably fabric-reinforced phenolic bearings. It is made up of a weldment to which are bolted two rims which form the groove of the sheave. In this groove are located a plurality, e.g., eight, arcuate segments of a plastics material, e.g., polyurethane material, which serve to protect the nose pieces of the fairings of the tow cable. A grease nipple is readily accessible for lubrication of the bearings~ !
The saddle assembly is a welded structure made of aluminum plates whose purpose is to provide a stable seating for the towed body dur-ing launching and recovery. The assembly is supported on the sheave shaft in bearings, preferably fibre-reinforced phenolic bearings. ~ grease nip-ple is readily accessible on each bearing for lubrication.
A plurality, e.g., eight, semi-spherical bumpers, preferably of polyurethane, are bolted to the underside of the assembly. They are posi-tioned to conform with the upper curvature sf the towed body and afford protection to the body during launching and recovery operations.
The design of cable guide effectively eliminates the need of hav-ing long side rollers extending aft sufficient to accommodate the various . .
8~9 tow cable angles. The cable guide assembly consists of two w~lded aluminum arms each supported at one end of the sheave shaft in bearings, preferably flbre-reinforced phenolic bearings. A grease nipple is readily accessible on each bearing for lubrication. The assembly is cross-connected at the other end of each arm with three spacer tubes. On two of the tubes are mounted freely rotating rollers, preferably fibre-reinforced phenolic rol-lers, one roller being forward of the tow cable and the other being aft.
Similar rollers are mounted on the side of each arm so that tow cable passes through the middle of the cluster of rollers. The cable guide assembly is connected to the saddle assembly by two constant torque band springs. These spring make the cable guide spring biased in a direction such that the for-ward roller always bears against the nose pieces of the fairings of the tow cable regardless of tow cable angle.
The saddle assembly is maintained in a horizontal attitude at all boom positions by a levelling assembly. Such assembly consists of two sets of two pulleys, one set being located on the port side, the other set being located on the starboard side. One pulley of each set is secured to the housing of the boom actuator and the other pulley of each set is on the saddle assembly. Each set of pulleys is connected by a cable, preferably a stainless steel cable that is fixed to each pulley by clamp pins.
The shock absorber system consists of two identical sets of com-ponents, one set being located on the port side of the winch frame, the other set being located on the starboard side. Each set consists of a spring return-type linear actuator which is hinged at its head end by hinge pins to the extreme forward side of the winch frame. The rod end only of each actuator is charged with a compressible fluid, e.g., a gas, for exam-ple, nitrogen gas, from a supply of two gas bottles which are mounted on the forward end of the winch frame. The gas pressure in the actuators can easily be changed by manipulating two valves on the hydraulic power unit.
The piston rod of the actuator is connected to a length of cable, which passes over a freely rotating pulley mounted on the winch frame. The cable is then connected to a torque arm that is secured to the boom assembly hinge point.
A body rest is attached to the boom in such a way that the towed body comes automatically to a seating in this body rest, when the boom ar-rives at its most inboard position. The body rest might support the body fully or only partially, in which case a supplementary deck-mounted support will coexist.
The towing system is hydrualically ~ctuated, the system being manually and electrically controlled from a hydraulic power unit. A feature thereof is that during launch and recovery operations the towed body is held firmly in the saddle by tension in the tow cable. This tension is maintained near constant by a pressure compensated, closed loop, hydrostatic drive system.
Movement of the boom about its mean hinge point during towing operations will cause, depending upon the magnltude of the cable load, a compression or expansion of the gas and the springs within the actuator.
This compression or expansion will only be sufficient to set up a moment on the boom to counteract the moment caused by the cable load. During tow-ing operations, the boom is positioned at an angle of 0~ and the gas pres-sure in the actuators is sdjusted so that with a steady cable pull the boom remains relatively still. If the cable pull increases, the boom will drop down and the gas and springs within the actuators will be compressed. The boom will drop only that amount that the moment on the boom due to the actuators will increase sufficiently to counteract the m~ment caused by the increased cable pull. If the cable pull decreases the boom will rise and the gas and springs will expand. Again the boom will rise only that amount that the moment on the boom due to the actuators will decrease sufficiently to counteract the moment caused by the decreased cable pull.
A hydraulic power unit is provided to operate the system. It includes a variable displacement axial piston pump system having both manual and pressur~ compensation controls. A closed loop, including a double shaft electric motor and pump, provides a hydrostatic drive system that drives the winch motor at variable speed and in both directions.
Also included in the hydraulic power unit is a fixed displacement tandem gear pump. One outlet of the pump supplies oil, filtered through filter to the boom circuit; the other outlet supplies oil, filtered through filter, for release of the winch brake and for the swash controls of the variable displacement pump.
The above components together with several valves are mounted on a reservoir. The reservoir, in one of its em~odiments, is a welded alumin-um structure provided with the usual gear, e.g., clean-out covers, a filler-breather cap, an oil level gauge and a drain valve. It is also pro-vided wi th oil strainers to protect the pump from contamination.
The winch assembly is driven by a low speed, high torque, radial piston hydraulic motor which is of the rotating housing type. The band brake which is spring applied and hydraulically released by a linear actua-tor acts on the outer surface of the motor housing. The motor, band brake and actuator are mounted on a common base.
The boom is preferably moved by a hydraulic, double vane-type, rotary actuator, which has a maximum angular travel of 155D.
It should be recognized that the preceeding description commencing on pa~e 6 herein is concerned solely with the description of Canadian Patent No. 1,005,702 when outfitted with a drum variant as shown in Figure 1 of the present application but with a direct drive, that is, with gear 19 replaced with a motor direct coupled to shaft 15. While other variants as shown in Figures 2 - 5 of the present application (to be described hereinafter) could also be adapted for use with Canadian Patent No. 1, 005,702, this could entail alterations in the mechanical interre~ationship, adaptable by a person skilled in this art.
~- 16 -In the accompanying drawings, Figure 1 is a central vertical cross-section of the cable wind-up winch drum of one aspect of this invention;
Figure 2 is a central vertical cross-section of the cable wind-up winch drum of another aspect of this invention;
Figure 3 is a central vertical cross-section of the cable wind-up winch drum of the aspect of Figure 2 and includes one aspect of a drive and a stationary base;
Figure 4 is a side elevation of the cable wind-up drum of the as-pect of Figure 2 including one aspect of a dri~e and a wheeled base; and Figure 5 is an end elevation of the hoist of Figure 4.
The cable wind-up winch drum, which may used in the system des-cribed above in Canadian Patent No. 1.005,702 is, as seen in Figure 1, the main drum 10 includes a pair of spaced-apart circular exterior housing plates 11, 12 connected between a hollow cylindrical core 13 and an outer cylindrical wall 14. The drum 10 is secured to a central shaft 15 which is mounted for rotation in spaced-apart bearings 16 secured within spaced-apart pedestal supports 17 mounted on the deck 18. The main drum is provided with a bull. gear 19 secured to plate 12 and bull gear 19 is adapted to be driven by a gear and motor ~not shown). While a bull gear drive i.s shown, the drum 10 may also be driven by other gearing arrangements connected to the rotating shaft 15, or may be direct driven by a motor. The outer cylin-drical wlal 14 is provided with a plurality of grooves 21 adapted to accomo-~.,, - 16 a -date the cable 22 provided wlth fairings 23.
By a main embodiment of the present invention, an annular, radial slot magazine 24 is provided ad~acent plate 12. This radial slot magazine 24 i~ shown fllled with unfaired cable 22. The bottom cylindrical plate 25 : is provided with a plug receptacle and strain termination arrangement 26 through whichconductor cable 27 is led. The conductor cable 27 is led out an aperture 28 in the plate 11 and through an aligned aperture 29 in an enlarged, flanged bearing journal of shaft 15. The end of the cable is led to an external cable winder 30. Cable winder 30 is fully described in Canadian Patent No. 856,639 issued November 6, 1970. Since the cable winder does not form an essential part of the present invention, it will not be described further. The cable winder, which may be of any well-known structure, provides elec.rical continuity from the conductors (not shown) of the tow cable 22 to the internal sonar circuits (not shown) of the ship.
The function of the winch drum 10 is to pay out and haul in the desired length of the tow cable 22, and to assist the boom and actuator assembly in the launch and recovery of the towed body. It is seen that the radial 810t magazine 24 allows for the spooling of a large excess of un-faired cable 22 in several layers. This takes up no more room than would be required by the number of 'dead' turns, normally left as a ssfety mar-gin on a conventional drum when all the faired cable has been paid out. As the cable 22 is used up due to shortening and retermination of the cable, filler pieces (not shown) are introduced into the radial slot magazine 24 beneath the reduced number of layers of unfaired cable.
As seen in ~igures 2 and 3, the main drum 40 includes an exterior housing plate 42 and an internal housing plate 41 connected between a hollow cylindrical spacer tube 43. The drum 40 is supported on spaced-apart drum bearings 46 mounted centrally within plates 41, 42. The bearings 46 are adapted to rotate on stationary shaft 4~ ~hose ends are secured 1.8~
within spaced-apart pedestal supports 47 mounted on the deck 48.
The drum 40 is provided with an outer cylindrical wall 44, pro-vided wirh a plurality of grooves 51 adapted to accommodate the cable 22 provided with fairings 23. The fairings 23 as shown are fairing elements ; comprising a rigid body member having opposed ends providing abutting sur-face of ad~acently disposed fairing elements located in end-to-end align-ment, Outer cylindrical wall 44 extends beyond the edge of plate 42 to terminate in an annular rim plate 52. A fixed external housing support plate 53 is secured around stationary shaft 45. Sliding connection between rim plate 52 and the rim 54 of housing support plate 53 is by means of sealed flange 55.
In this embodiment of the invention as shown in Figures 2 and 3, a radial slot magazine 64 is provided against plate 42. The radial slot magazine 64 is shown filled with unfaired cable 22. The bottom cylindri-cal plate 65 is provided with a plug receptacle and strain termination arrangement 66 through which conductor cable 27 is led. The conductor cable 27 is led through aperture 68 in plate 41. The end of the conductor cable 27 is then led to the bottom cylindrical surface 69 of a rotating conductor cable drum 70. The conductor cable 27 ls wound on durm 70 by means of a winder mechanism to be described later. The main drum 40 is 20 rotated by means of a bull gear 48a mounted on plate 42. The precise means of drlving bull gear 48a is not shown ln Figure 2, but, as shown in Figure 3, the drive means comprises a drive or bull pinion 71 connected to a drive motor and brake assembly 72. In addition, as seen in Figure 3, one of the pedestal supports 47 is replaced by a combined shaft and drive shpport 73. The durm 40 is shown mounted on a plain base 74.
A preferred form of cable winder mechanism for the conductor cable 27 is shown in Fi~ures 2 and 3. The cable ~7inder mechanism provides A the means for maintaining electrical continuity between the conductors of the tow cable 22 and the internal sonar circuits of the ship without the use of the slip rings. As shown in Figures 2 and 3, the cable winder mechanism includes an arm 75 attached intermediate its ends to shaft 45 for rotation about a hub 76. Arm 75 terminates at one end in a bufurcated por-: tion 78 having a sheave 79 pivotally secured thereto by a pin 80. Theopposite end of the arm 75 is provided with detachable counterweights 77.
AccordiDgly, arm 75 is adapted to pivot about the axis of shaft 45. The sheave 79 is freely rotatable about pin 80, with the axis theraof being perpendicular to the axes of the arm 75.
The winder mechanism is attached via torque tube 100 to a NEGATOR
(registered Trade Mark) spring assembly 82 which consists of a coiled band spring 84 and an anchor 85 on torque tube 100 for the band spring 84. The band spring 84 has a selected length which is coiled onto a storage spool 101, and the stored coil band spring 84 resists uncoiling. The coiled band spring 84, acting to try to uncoil itself biases the bar 75 in an opposite direction. The band spring 84 preferably has substantially con-stant torque characteristics.
As noted before, the conductor cable 27 is routed onto the rotat-ing drum 70. It then passes over the sheave assembly 79 and onto the stationary drum 83. From this drum 83, the cable 27 passes through a stuf-fing tube to the internal circuits of the ship. Rotation of the winch drum 40 in either direction causes the conductor cable 27 to pass back and forth between the rotating drum 70 and the stationary drum 83 via the sheave a~sembly 79. The sheave assembly 79 which is counter-balanced at one end by a weight 77 is connected to the NEGATOR spring assembly 82.
This spring assembly 82 maintains the sheave assembly 79 spring biased, thereby maintained a nominal tension the conductor cable 27 at all times.
From drum 83, the conductor cable 27 is led out the end of the plate 53 through stuffing tube 81 and may be connected to an external cable winder, e.g., that described in Canadian Patent No. 856,639.
,' -- 19 --8~9 As seen in Figureg 4 and 5, the base 90 of the hoist assembly on whlch the shaft support 47 is moutned is provided with a plurality of rol-lers 91, and a transverse plurality of rollers 93. These rollers run in a base track 92.
The base 90 is thus shown with wheels for linear translation of the entire hoist to control fleet angle of the cable as it is wound on an off the drum. The ~ranslating de~ice and drive is not shown; it may be a hydraulic cylinder, a screw, or other means. However, the base may also be plain and fixed to the ship's deck. It may also have wheels and a kingpin for angular translation as described in Canadian Patent No. 855, 578. There may also be no base at all; the shaft supports may be bolted directly to a reinforced deck.
- 19 a -
Claims (15)
1. An improvement in a system for launching, towing and recovering a towed body from a towing surface vessel using faired towing cables, said system including a hoist sub-assembly and a boom sub-assembly, said improvement comprising: a main winch drum in said hoist sub-assembly for storing live turns of said faired towing cable wound in a single layer in a first direction, which faired cable is adapted to be wound on and un-wound off said main winch drum, said main winch drum including a slot magazine recessed into the interior thereof at one end thereof for storing dead, unfaired towing cable wound in multi-layers in the same first direction thereon; said main winch drum including a single cable clamp completely inboard of all turns of said faired and unfaired cable and near the inboard end of the cable.
2. The improvement of claim 1 wherein said cable includes a conductor secured to said towing surface vessel and extending through said cable.
3. The improvement of claim 1 wherein said main winch drum is secured to a rotatable main shaft.
4. The improvement of claim 3 wherein said main winch drum is driven by a bull/gear pinion arrangement by a drive motor and brake assembly.
5. The improvement of claim 1 wherein the slot maga-zine is provided with a plug receptacle and strain-terminating arrangment by means of which towing cable is secured to conductor cable; and including means leading conductor cable out an end of said main winch drum to be connected to an external cable winder to provide electrical continuity from the conductor cable.
6. The improvement of claim 1 wherein said main drum is rotatably mounted on a fixed shaft.
7. The improvement of claim 6 wherein said main drum is driven by a bull gear/bull pinion arrangement by means of a drive motor, and wherein said bull gear/bull pinion arrange-ment includes a brake assembly.
8. The improvement of claim 7 wherein said main winch drum includes one section containing said slot magazine, and an integral section containing a cable winder mechanism therein.
9. The improvement of claim 8 wherein said slot magazine is provided with a plug receptacle and strain-terminating arrangement by means of which towing cable is secured to conductor cable; and including means leading conductor cable to a coaxial rotating drum.
10. The improvement of claim 9 wherein said cable winder mechanism for said conductor cabe includes: an internal coaxial rotating drum, a stationary storage drum, and a counter-weighted arm including a freely-rotatable sheave for engaging said conductor cable for transferring the conductor cable out an end of said coaxial rotating drum to a stationary storage drum, said conductor cable being connected with conducting cable in said towing surface vessel to provide electrical continuity.
11. The improvement of claim 10 wherein said cable winder mechanism is adapted to engage said conductor cable at positions disposed in respective overlapping relation with res-pect to said coaxial rotating drum and said stationary storage drum, and movable about the periphery thereof for transferring a portion of said conductor cable engaged thereby from one drum in response to rotational movement of said main winch drum; said cable winder mechanism being said means for providing electrical continuity from conducting cable in said towing sur-face vessel to the conductor cable.
12. The improvement of claim 11 wherein said winder mechanism is mounted externally of said winch sub-assembly.
13. The improvement of claim 11 wherein said winder mechanism is mounted internally within said main winch drum.
14. The improvement of claim 1 wherein said main winch drum is mounted on a rolling base for linear translation of said hoist sub-assembly, thereby to control the fleet angle of said faired cable as it is wound onto and off said main winch drum.
15. The improvement of claim 14 wherein said rolling base of said winch sub-assembly is provided with wheels for linear translation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,652A CA1111829A (en) | 1979-04-18 | 1979-04-18 | Wind-up drum for faired cable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,652A CA1111829A (en) | 1979-04-18 | 1979-04-18 | Wind-up drum for faired cable |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1111829A true CA1111829A (en) | 1981-11-03 |
Family
ID=4113988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA325,652A Expired CA1111829A (en) | 1979-04-18 | 1979-04-18 | Wind-up drum for faired cable |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1111829A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4597352A (en) * | 1983-07-15 | 1986-07-01 | Norminton Robert S | Compact towing system for underwater bodies |
| US4754442A (en) * | 1986-05-27 | 1988-06-28 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence | Variable depth sonar line handling system |
| EP3632835A1 (en) * | 2018-10-02 | 2020-04-08 | Goodrich Corporation | Hoist cable sensor with differential drive |
| CN111896040A (en) * | 2020-08-20 | 2020-11-06 | 王佩贵 | Underwater detection device convenient to fold and unfold |
-
1979
- 1979-04-18 CA CA325,652A patent/CA1111829A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4597352A (en) * | 1983-07-15 | 1986-07-01 | Norminton Robert S | Compact towing system for underwater bodies |
| US4754442A (en) * | 1986-05-27 | 1988-06-28 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence | Variable depth sonar line handling system |
| EP3632835A1 (en) * | 2018-10-02 | 2020-04-08 | Goodrich Corporation | Hoist cable sensor with differential drive |
| CN111896040A (en) * | 2020-08-20 | 2020-11-06 | 王佩贵 | Underwater detection device convenient to fold and unfold |
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