US3086232A

US3086232A - Method of and apparatus for spinning cables for suspension bridges

Info

Publication number: US3086232A
Application number: US62134A
Authority: US
Inventors: John E Nixon
Original assignee: Colorado Fuel and Iron Corp
Current assignee: Colorado Fuel and Iron Corp
Priority date: 1960-10-12
Filing date: 1960-10-12
Publication date: 1963-04-23
Anticipated expiration: 1980-04-23
Also published as: GB942333A

Description

"April 23, 1963 J. E. NIXON 4- METHOD OF AND APPARATUS FOR SPINNING CABLES FOR SUSPENSION BRIDGES 5 Sheets-Sheet 1 Filed Oct. 12, 1960 A ril 23, 1963 J. E NIXON METHOD OF AND APPARATUS FOR SPINNING CABLES FOR SUSPENSION BRIDGES Filed Oct. 12, 1960 5 Sheets-Sheet 2 Aprll 23, 1963 J. E. NIXON 3,086,232

METHOD OF AND APPARATUS FOR SPINNING CABLES FOR SUSPENSION BRIDGES Filed Oct. 12, 1960 5 Sheets-Sheet 3 Aprll 23, 1963 J. E. NIXON 3,086,232

METHOD OF AND APPARATUS FOR SPINNING CABLES FOR SUSPENSION BRIDGES Filed Oct. 12, 1960 5 Sheets-Sheet 4 5 Sheets-Sheet 5 A I Q 7 J. Ev NIXON SUSPENSION BRIDGES METHOD OF AND APPARATUS FOR SPINNING CABLES FOR April 23, 1963 Filed Oct. 12, 1960 nited States 3 (P86 232 METHDD OF AND AllPARATUS FOR SPINNENG CABLES FOR SUSPENSION BREDGES John E. Nixon, Langhomc, Pan, assignor to The Colorado Fuel and Iron Corporation, Denver, Colo., a corporation of Colorado Filed Oct. 12, 1960, Ser. No. 62,134 27 Claims. (Cl. 14-23) This invention relates to a new method of and apparatus for spinning or laying the wires for parallel wire suspension cables for bridges and the like. 'An important aspect of the invention is the elimination of the necessity The present invention involves the spinning or laying into a strand of the final cable of only a single, dead wire upon each passage of a carriage across the bridge structure. Also it enables the use of only comparatively small coils of wire as the source of supply in the course of laying the wires, such coils being light enough to be mounted on the carriage which traverses the bridge structure. It has been found that this greatly facilitates the laying of the required number of wires to form a suitable strand for the cable and reduces the cost of the operations required for the completion of a suspension cable.

This is a continuation in part of applicants pending application Serial No. 772,238, filed on November 6, 1958, and now Patent No. 2,971,255. In that application, which is primarily directed to carrying across the bridge structure loops of wire having a dead wire and a live wire, a novel mode of adjusting the various wires to the proper length is disclosed. The mode and means for adjusting the length of the various wires, as disclosed in said application, may be used to advantage in connection with the present invention. But this invention is concerned primarily with the procedure and apparatus by which the individual wires entering into a suspension cable are laid.

=T-he term dead wire, as used herein, should be understood .to mean a wire which has its free end anchored at one end of the bridge structure and which does not shift bodily in a longitudinal direction as it is laid across the bridge structure. A live wire on the other hand, is one which is continuously being drawn from a source of supply to form one leg of a loop, the other leg or branch of which is held stationary adjacent the source of supply and thus becomes a dead wire. In such an operation the live Wire is carried forwardly at twice the speed with which the dead wire is being laid.

Under the system contemplated by the present invention the wire supply, as stated above, is in the form of coils which are carried across the bridge structure in the course of laying a single wire. The free end of the wire being laid is anchored at one end of the bridge structure and the supply coils are carried across the bridge structure by a suitable carriage or tram. When the latter reaches the .far end of the bridge structure, it is passed around a suitable turn-around track and is then carried back to its starting point. The original length of wire first carried across may be suitably adjusted as to length in accordance with the method disclosed in said patent and it may be anchored at the far end of the bridge structure at its properly adjusted length to conform with the desired catenaries of the final cable. On the return of the coil carrying carriage toward the initial end of the bridge structure another wire to be incorporated in a strand will be payed out from the coils on the carriage. This 3,086,232 Patented Apr. 23, 1963 ice will be a dead wire extending from the anchorage at the far end of the bridge structure.

When the carriage reaches the initial end of the bridge structure it will be passed around a suitable turnaround track of the same character as is provided at the tar end of the bridge structure. The new wire which has been laid may be adjusted as to length, as by the technique disclosed in said pending application, and the measured length of wire may be anchored by a strand shoe, or the like, at a point adjacent that at which the initial end of the wire was anchored. The same cycle of operations may then be repeated as many times as required to lay out successively a sufficient number of dead Wires to form a strand of the final cable. In the conventional manner, strands may be adjusted and set in the towersaddles and additional strands may be produced and similarly set to complete the final cable.

The wire which is carried across the bridge structure, in the manner described above, may be delivered to the site of the bridge at each anchorage thereof in coils weighing about 360 lbs. each. The tram or carriage is preferably adapted to carry three such coils from which the wire is successively payed out in the course of travel of the carriage across the bridge structure. At each end of the latter, provision is made for adding new coils of wire to the carriage to replace those which have become exhausted in the course of travel of the carriage across the bridge structure. In adding such new coils to the carriage the outer, free end of one coil is connected with the inner,

free end of the last coil remaining on the carriage and the inner, free end of the coil so connected is connected to the router, free end of the next coil added to the carriage,

Such connection of the free ends of successive coils may be provided by nipples or ferrules of the character disclosed in said pending application, these serving to provide a juncture between the connected free ends of the wire having a tensile strength at least as great as that of the wire itself.

As in the conventional practice of forming parallel wire suspension cables for bridges, the wire employed may suitably have a diameter of .196 inch. If three coils of such wire are applied to the carriage, each coil weighing 360 lbs., the total length of the wire available on the carriage will be approximately 12,000 feet. This is usually more than adequate to provide for the laying of a wire completely across the bridge structure from one anchorage to the other. If a greater length of wire is required for this purpose, the carriage may be adapted to receive, say, four coils of wire to avoid the necessity of adding rurther coils to the carriage at any point other than the two anchorages.

The carriage employed in accordance with the present invention is of special construction and has a relatively long downwardly extending frame of lightweight but strong construction. At its upper end the frame is provided with a truck member having pulley-like wheels adapted to ride along the top of a track strand of suitable tensile strength to carry the required load. The abovementioned frame structure depends vertically from the truck. Since the track strand must be laid along a path substantially parallel with the desired catenary form of the final cable, it will be understood that the truck mentioned will sometimes be inclined upwardly in the direction of travel and sometimes downwardly in the direction of travel. The frame structure mentioned, on the other hand, always remains in a vertical position so that the coils oat wire will always be directly below the truck. and will serve to maintain the latter in a balanced condition on the track strand.

For the purpose of moving the truck with its coil carrying frame across the bridge structure, an endless hauling rope is provided. Readily disconnectable clamping means may be employed for connecting the vertical frame structure to the hauling rope and to release said structure from the hauling rope at desired points in the path of movement of the truck. Such connection and release of the clamping means is preferably effected automatically. Means are provided at one of the anchorages for driving the hauling rope continuously at a desired speed. The hauling rope passes around turn-around sheaves at eac anchorage and the arrangement is such that one branch of the looped hauling rope travels in one direction and the other branch travels in the opposite direction. This enables the connection of the coil carrying frame structure to one branch of the hauling rope for drawing the carriage, consisting of said frame structure and the truck, from the initial end of the bridge structure to the far end and for similarly connecting the coil carrying structure to the opposite branch of the hauling rope for drawing the carriage from the far end back to the initial end of the bridge structure.

An important feature of the invention involves the provision of special means for carrying the coils of wire on the carriage structure in a manner to permit turning of the coils as the wire is payed out therefrom and also in a manner to apply a suitable tension of, say, 100 lbs. to the wire as it is being laid. Special braking means adapted for automatic application and release, as the carrige passes certain points in its path of movement, are provided.

Another special feature of the coil carrying structure is that it includes a readily expansible and retractable drum arrangement which facilitates the application of new coils. Thus, when new coils are to be applied to the carriage, the diameter of the coil carrying drum is reduced and after the coils have been applied, the diameter is increased so that the coils are firmly held in place on the drum and rotate with the latter.

Other advantageous features of the invention will appear from a detailed description of a preferred embodiment of the same which will now be given in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view in plan showing the hauling cable, the track strand, the turn-around rail and related parts at one end of the bridge structure;

FIG. 2 is an elevational view showing the general relationship of the parts disclosed in FIG. 1;

FIG. 3 is a transverse view through the layout shown in FIG. 1 taken along the line 3-3 of FIG. 1;

FIG. 4 is a transverse view taken along the line 4-4 of FIG. 1;

FIG. 5 is a side elevational view of the carriage with its depending frame structure carrying the coil receiving drum and related parts;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5;

FIG. 7 is a detail view partly in elevation and partly in section, taken along the line 7-7 of FIG. 6;

FIG. 8 is a schematic view showing a reservoir for compressed air and a valve system for controlling the brake on the coil carrying drum structure;

FIGS. 9, 10 and 11 are schematic views, in section, showing the brake controlling valve in three different positions;

FIG. 12 is a view, partially in plan and partially in hori zontal section, showing a clamping device mounted on the coil carrying structure and adapted to connect the same with the hauling rope;

FIG. 13 is a view, partly in elevation and partly in vertical section, of the clamping device and the adjacent portion of the frame structure;

FIG. 14 is a longitudinal sectional view through the clamping device and supporting structure, taken along the line 14-14 in FIG. 12; and

FIG. 15 is a transverse, sectional View through the clamping device, taken along the line 15-45 of FIG. 12.

It will be understood that before the laying of the wires for the suspension cables of a suspension bridge is undertaken, a substantial amount of preparatory work will have been done in connection with the construction of the bridge. Thus, suitable towers will have been erected along the course of the bridge structure to carry the suspension cables. Also, considerable construction work will have been performed at the anchorages at the two ends of the bridge structure. When this preliminary work has been completed, a pair of

track strands

11 and 11 will be laid across the various supporting structures, including the tops of the towers at the opposite sides of the main channel over which the bridge is to extend. These track strands will be caused to follow substantially the contour of the catenaries to be assumed by the suspension cables. They will, however, be disposed somewhat above the path to be assumed by the cables. At each end of the bridge structure the

track strands

11 and 11 will be deflected outwardly and downwardly about sheaves 11a and their extreme ends will be firmly anchored at 12 and 12' by strand shoes or the like. Throughout their major portions the strands 11 and 11' will be parallel and spaced a suitable distance apart, say, four or five feet.

The strands 11 and 11' are adapted to provide tracks along which a coil carrying structure, indicated generally at 13 in FIGS. 1 and 2, may be moved. For this purpose a truck or tram having a pair of sheave-like Wheels 14 is mounted at the upper end of the structure 13. The details of this construction will be pointed out more fully hereinafter. Movement of the coil carrier along one or the other of the track strands is brought about through a hauling rope 15 which is of endless construction and has two branches or courses which extend across the bridge structure. At each end of the bridge, the hauling rope is provided with looped turn-around portions. One course of the hauling rope is disposed directly beneath the track strand 11 and the other course is disposed beneath the track strand 11' in the regions in which these track strands are parallel. As indicated in FIGS. 1 and 2, the hauling rope at the left anchorage of the bridge structure is passed beneath a series of hold-down sheaves 16 and then around a sheave 17 having its axis disposed at an appropriate angle to direct the hauling rope outwardly and downwardly. The rope then passes aroundanother sheave 1.8, mounted to turn about an angularly disposed axis, and it extends beyond this in a horizontal plane to a sheave 19 and across to another sheave 20 from which it extends horizontally to an angularly disposed sheave 18', another angularly disposed sheave l7 and plurality of hold-down sheaves 16' which serve to lead it into a position directly beneath the track strand 11'. Between the

sheaves

19 and 20, any suitable means may be provided for driving the hauling rope. For this purpose there is shown a sheave 21 driven by a motor 22. Suitable reduction gearing may be provided between the motor and the shaft carrying the sheave 21. Any appropriate means is provided for creating the desired frictional contact between the sheave 21 and the hauling rope to enable the application of an adequate pulling force to the latter. For this purpose a suitable length of the rope may be forced into good frictional engagement with a substantial arc of the pulley 21 or the rope may be given one complete turn about this pulley which should then be suitably grooved to accommodate the turn of the hauling rope.

As will be explained more fully hereinafter, the coil carrying structure 13 is provided with a releasable clamp for gripping the hauling rope 15 so that the latter will haul the carrier across the bridge structure. As the carrier reaches an appropriate position in the region of the hold-down sheaves 16, means may be provided for automatically releasing the gripping device so that the carrier may then be shifted by hand or any other suitable means around the turn-around loop. A rail 23 is provided at the turn-around along which the wheels 14 of the carrier 13 may roll. This rail is suitably supported on the structure 19 by arms 23a provided at approximately spaced points. The rail has two parallel extensions at the right end thereof (FIG. 1) terminating at points 2.4 and 24 which are disposed close to the parallel portions of the

track strands

11 and 11 and provide a continuation of the track formed by the strands. As the carrier 13 reaches the point 24, the wheels 14 of the carrier will ride off of the track strand and on to the rail 23. Similarly, on the opposite side, as the carrier, on its return movement, reaches the point 24' of the rail 23, the wheels 14 will ride off of the rail and on to the track strand 11.

As shown in FIGS. 1, 2 and 3, there is positioned, adjacent the loop of the rail 23 in the region in which the coil carrier 13 is shown, a turntable 25 mounted on a vertical standard 26 and arranged to be turned about the axis of the latter either by hand or by suitable power means. Coils of wire of the character to be mounted on the coil carrier 13 may be applied to the turntable 25 either at the position A or the position B. When the coils are so mounted by a workman, with the assistance of suitable hoisting and shifting mechanism, onto a projecting arm portion of the turntable 25 the latter may be rotated to carry the coils into position C(FIG. 1). At this point the coils will be alined with the drum on the coil carrier 13 and may be applied to the latter either manually or with the assistance of appropriate lifting and pushing means. As the new coils are applied to the coil carrier 13, an operator stationed at 27 and provided with a nipple press draws the inner free end of the last coil on the coil carrier toward the station 27 and also draws the outer free end of the next adjacent coil which has been applied to the coil carrier at station C and connects these free ends together by a suitable nipple or ferrule. The inner free end of the first coil applied to the carrier is similarly connected with the outer free end of the second coil applied to the carrier, and if a third coil is being applied, the outer free end of its wire is connected to the inner free end of the second coil that has been applied. The coil carrier 13 is now in condition to be shifted around the rail 23 and on to the track strand 11 at the position 24. At this point, or at a slightly earlier point in the region of the sheaves 16", the clamping means on the coil carrier may be operated to grip the hauling rope 15 and thus start the return movement of the coil carrier to the initial end of the bridge structure. As has been stated, the structure illustrated in FIGS. 1 and 2 is duplicated at the initial or right end of the bridge structure, but in reverse relationship so that the same procedures may be followed at that end when the coil carrier has been carried across, and the latter is thus prepared for return tothe left end of the bridge structure for a repetition of the same cycle.

Referring now to FIGS. 5, 6 and 7, the construction of the coil carrier is shown in greater detail. The sheavelike wheels 14 are shown as riding upon the track strand 11. These wheels are carried by a frame comprising two side members 28 having bolts 14a extending therethrough which serve as journals for the wheels 14. Spacing sleeves or other means serve to hold the frame members 28 in properly spaced relation. Depending from the frame members 28 and arranged to turn about a horizontal axis in relation thereto are frame members 29 of the coil carrier, these being suitably of I-beam construction. They have welded thereto a pair of plates 29a adjacent their upper ends, and a sleeve 2% is welded to these plates. The sleeve 2% is journaled upon a hollow shaft 30 fixedly carried by the frame members 28. If desired, the shaft 30 may be fixedly carried by the frame members 29 and arranged to turn freely in relation to the frame members 28 Suitable means are provided for preventing relative axial movement between the shaft 30 and both the members 28 and the sleeve 2%.

Some distance below the shaft 30 two, cross-members 31 and 32 (FIG. 5) are suitably secured to the frame members 29. Cross-members 31 and 32 may be of channel construction and may be welded to plates 33 at their opposite ends, these plates being in turn welded to the frame members 29. Two plates 34 and 35 (FIG. 6) held in spaced relation by collars, or the like, are secured by bolts 36 to the cross-members 31 and 32. The plate 35 preferably bulges outwardly toward the right (FIG. 6) and at its center carries a sleeve 37 (FIGS. 12, 13 and 14) which also extends through a similar opening at the center of the plate 34. Sleeve 37 is secured by welding, or the like, to the two

plates

34 and 35. Within the sleeve 37 is rotatably mounted a rock member having a disc-like portion 38 at its right end which cooperates with the right end of the sleeve 37 and the adjacent face of the plate 35 (FIG. 14). A portion 39 of the rock member having a slightly reduced diameter is journaled for rocking movement within the sleeve 37. A further reduced portion 40 of the rock member extends toward the left into the space between the frame members 29. A snap ring 41, or the like, serves to retain the rock member 38, 39, 40 against axial movement in relation to the sleeve 37 but permits turning movement in relation to the latter. Extending outwardly from the face of the portion 38 of the rock member is a hook having two branches 42, as best seen in FIG. 12, which extend over the top of and are adapted to grip the right side of the hauling rope 15. A cooperating clamping element 43 having a portion arranged to ride over the top of the hauling rope and a portion 43a arranged to grip the left side of the hauling rope (FIG. 14) is carried by a slidahle rod 44. The latter is screw-threaded at its left end 45 and secured in a screw threaded socket of a link 46 which is slidable within a cylindrical cavity 40a in the rock member.

As best shown in FIG. 15, the portion 40 of the rock member has two llat sides with which cooperate respective parallel arms 48 and 49 of a lever 47. The arms 48 and 49 are pivotally connected with the portion 40 by means of screw studs 56]. At its left end the lever 47 has a cross-member 51 provided with a vertically extending opening therethrough in which is mounted a rotatable disc 52. The latter is journaled by a pin 53 within the opening of the cross-member 51. When the lever 47 is in its horizontal position, as shown in FIG. 13, the two jaws 42 and 43 of the clamp serve to grip the hauling rope 15, causing some deflection in its contour, as shown in FIG. 12, and thus insuring a firm grip. This will result in movement of the coil carrier along the track strand at the rate determined by the speed of movement of the hauling rope. It should be noted that in the course of movement of the coil carrier across the bridge structure, the frame members 29 will always extend downwardly in a vertical direction from the shaft 3t). On the other hand, the track strand 11 and the hauling rope 15 will sometimes be inclined downwardly and at other times upwardly in the direction of movement of the coil carrier. This necessitates turning of the rock member 38, 39, 40 in relation to the sleeve 37. The members 44 and 46 will likewise turn with the rock member. It will be seen that the relationship of the various parts is such as to permit this.

When it is desired to release the clamping jaws 42, 43 from the hauling rope 15, the lever 47 may be shifted upwardly into the position shown in FIG. 14. When this is done, the clamping jaw 43' will be retracted by virtue of the connections now to be described. On a stud 54, extending through suitable openings in the arms 48 and 4? of the lever 47 and held in fixed relation thereto, is rockably mounted one end of a lever 55 the opposite end of which is forked and pivotally connected by a stud 56 with a flattened portion of the member 46. Thus, a toggle linkage is provided which, upon upward move ment of the lever 47, serves to shift the member 46 toward the left (FIG. *14) and thus draw the clamping jaw 43 toward the left. When it is desired to re-connect the coil carriage with the hauling rope 15 the lever 47 may be returned to its horizontal position or to a position slightly below the horizontal so as to produce a desired locking action.

Operation of the lever 47 may be manually eflected but it is preferably operated automatically as the coil carrier reaches certain predetermined positions. This may be accomplished by providing an angle member 57 (FIG. 6) having an appropriate sloping top surface which is engaged by the disc 52 when the coil carrier reaches a position in the region of the sheaves 16 (FIGS. 1 and 2). It will be understood that the disc 51 rides up the slope provided by the angle member 57 and thus shifts the lever arm 47 from the position shown in full lines to that shown in dotted lines in FIG. 6. Similarly, when the coil carrier is shifted around to a correspond ing position on the opposite side of the looped rail 23, i.e. in the region of the sheaves 16', the bottom face of another angle member 58 may be engaged by the disc 52 and the surface of angle member 58 which is so engaged may slope downwardly in the direction of the movement of the carrier so as to force the lever arm 47 back to the full line position shown in FIG. 6. The frictional resistance to the movement of the lever arm 47 should be sufiiciently great to cause the same to remain in any position into which it has been shifted. This is to avoid the accidental return of the lever from the clamp opening position shown in FIG. 14 as the coil carrier is shifted around the loop formed by rail 23.

As shown schematically in FIG. 6, the hauling rope is preferably guided at appropriate points along its course, as at the tops of the towers, by a pair of

sheaves

59 and 60. These should have such a peripheral configuration as to permit the jaws 42 and 43 of the clamp to pass between the sheaves. If desired, one of the sheaves of a pair may be spring urged toward the other so that the passage between the sheaves may be readily increased somewhat as the clamping jaws pass through.

Referring now to FIGS. 5, 6 and '7, the frame members 29 extend downwardly below the cross-member 32 and in this lower region converge toward each other. At their lower ends any suitable arrangement may be provided to inter-connect the two frame members and provide for the support of a coil drum and brake struc ture. Thus, there may be welded or otherwise secured to the frame members 29, adjacent their lower ends, a reinforcing member 61 having a transversely extending cylindrical support 62 which extends through a passage provided between the members 29 at their lower ends and projects a substantial distance toward the right (FIG. 6) from the latter. A plate 61a (FIG. 7) may also be welded to the lower ends of the members 29 on the opposite side thereof from the member 61. This provides further support for the member 62 which is, in effect, a stationary shaft that carries the coil drum and a brake drum associated therewith. The brake drum has a sleeve or hollow shaft 63 which is journaled upon the member 62. A brake drum 64 is keyed to the hollow shaft 63, as indicated in FIG. 7. As will be explained, the coil carrying drum is also secured to the hollow shaft 63 so that it and the brake drum rotate in unison. A brake band 65 surrounding the brake drum 64 has one end connected with the outer end of an arm of a bell crank lever 66 pivotally mounted on a stud 67 fixed to two crossmembers 67a welded to the frame members 29. Bell crank lever 66 preferably has two parallel side members of the same configuration, which are spaced sufficiently to accommodate the ends of the brake band and are interconnected in any suitable manner for movement as a single member. The opposite end of the brake band is connected with an extension of the pivot stud 67 of the bell crank lever. An upwardly extending arm of the latter has connected therewith a piston rod 68 extending from a piston 69 Within an air cylinder 70. This cylinder is mounted on a plate 71 welded or otherwise secured to one of the frame members 29. A spring 72 surrounding the piston rod 68 normally serves to rock the bell crank lever in a counterclockwise direction (FIG. 7) to tighten the brake band 65 and thus apply a braking force to the drum 64. This braking action is such as to apply a tension of about 100 lbs. to the wire being delivered from the coils on the coil carrying drum in the manner to be explained. The actual force applied to the hauling rope 15 by the motor 22 must exceed the desired pulling force to be applied to the coil carrying frame by an amount suflicient to overcome the frictional resistance to the movement of the hauling rope. Thus said pulling force must be in excess of, say, 100 lbs.

When the coil carrying unit is in the region of the tumaround loop at either end of the bridge, it is desirable to release the brake so that the coil carrying drum may be rotated relatively freely. For this purpose provision is made for the introduction of air into the cylinder 70 in a manner to move the piston 69 toward the right (FIG. 7) and thus overcome the action of the spring 72. Air for this purpose is introduced through a pipe 73 from a compressed air storage tank 74 carried by the frame members 29. The delivery of air from the reservoir 74 to the cylinder 70 is controlled by a valve 75, which may suitably be a Barksdale four-way air valve. It has a control lever 76 for rotating a valve element 77 (FIG. 10) within the housing of the valve 75. Normally, the element 77 is held by spring action in the position shown in FIG. 10 and it is restored to that position whenever the operating handle 76 is released. When the valve is in the position indicated in FIG. 10, it blocks off communication with all of the lines entering the valve structure. Thus, a line extending from the reservoir 74 is closed off at the valve. Also a line 81 extending from the cylinder 70 into the valve is closed off at the latter. When the valve element 77 is turned in a clockwise direction through an angle of, say, 45, into the position shown in FIG. 9, a passage 78 in the valve element serves to connect line 80 with line 81 and thus permits the delivery of air under pressure from the storage tank 74 to the cylinder 70. Preferably a valve 82 is provided in the line 81 to meter the air delivered to the cylinder 70 and thus prevent a too rapid release of the braking force of the band 65 upon the brake drum 64. After the brake has been released, the handle 76 may be released and returned under the spring action mentioned to its central position in which the valve will be restored to the condition shown in FIG. 10. This will serve to retain the air under pressure in the cylinder 70 and thus hold the brake in released condition.

When it is desired to restore the braking action upon the drum 64 the valve element 77 may be turned in a counterclockwise direction into the position shown in FIG. 11, by the appropriate movement of the lever 76. When in this position, the line 81 extending from the cylinder 70 is connected by the passage 78 of the valve element with a discharge line 83. The latter is preferably provided With a metering valve 84 to further retard the discharge of air from the cylinder 70 and thus bring about a slow and gentle application of the braking action. It will be noted that when the rotary valve element 77 is in the position of FIG. 11, the line 80 extending from reservoir 74 communicates with passage 79 in the valve element but the opposite end of this passage is closed off by a plug 85. If desired, the passage 79 can be omitted from the rotary valve element 77.

Provision is made for recharging the air reservoir 74 at either end of the bridge structure. For this purpose a pipe 86 extending from the reservoir is provided with a quick attachment fitting 87 by which a line from a larger source of compressed air may be connected into the reservoir 74 to build up its supply of compressed air. Also at each end of the bridge structure there is preferably provided automatic means for operating the valve 75. Thus, as shown in FIGS. 1 and 6, there may be provided an angle iron frame 88 which may be in a region below the sheaves 16 (FIG. 2) adjacent the region in which the angle member 57 is located. Member 88 has an upwardly sloping surface which will serve to rock the arm 76 upwardly, or in a clockwise direction, as the coil carrying frame is drawn toward the left, and will thus bring about delivery of air under pressure into the cylinder 70 to release the brake. On the opposite side of the turn-around loop in the region of the sheaves 16' an angle member 89 may be provided, this having a downwardly sloping bottom surface adapted to act upon the lever 76 and rock the same downwardly, or in a counterclockwise direction, to bring about restoration of the brake action.

Secured to the sleeve or hollow shaft 65, toward the right of the brake drum 64 (FIG. 6), are six pairs of hollow cylinders or tubes 90, these being spaced at 60 intervals around the shaft 63. They may be secured to the latter in any suitable way, as by welding. At its outer end each of the cylinders or tubes 90 receives telescopically a hollow cylinder or tube 91. This arrangement is such that the radial length of the arm formed by each set of

tubes

90 and 91 may be lengthened or contracted. Adjacent the outer ends of the tubes 90 of each set, i.e. the right hand and left hand sets (FIG. 6), there is welded to the outer surfaces of the tubes a ring 92 to assist in maintaining the tubes in their fixed radial positions. At the outer ends of each pair of tubes 91 whose axes are in the same radial plane from the axis of the shaft 63 there is fixedly mounted the mid-point of a segment of the coil carrying drum. As shown in FIG. 5, there may be six such segments. Each comprises a front, flat, plate-like member 93 and a rear, flat, plate-like member 94 welded to the outer face of the related tube 91. The member 94- has a plurality of radially extending reinforcing ribs 95 welded to the plate 94 and also to an outwardly extending portion 96 of a segmental member 97 which is adapted to support the coils of wire which are indicated in broken lines. Each of the members 93 has a plurality of laterally extending ears 98 providing pivots for arms 99 which may be swung into the full line position shown in FIG. 6 or downwardly into the broken lineposition shown. Any suitable means may be provided for locking the arms 99 in the full line position shown. It will be appreciated that when the coils are being applied to the drum the arms 99 will be swung downwardly into the dotted line position and after the coils have been assembled on the drum the arms are swung upwardly again and locked in the full line position shown.

The means for shifting the various segments of the drum outwardly and inwardly in a radial direction will now be described. As shown in FIG. 6, each pair of tubes 90 has secured thereto by welding, or the like, a plate 100 extending between the pair of tubes in a direction transverse to the axes of the tubes in the mid-region thereof. This plate has secured to it, by bolts or the like, an air cylinder 101 havingtherein a piston 102.. The piston is normally urged toward the axis of the shaft 63 by a spring 103 surrounding a piston rod 104- within the air cylinder. At its upper end the piston rod 104 is connected with a plate i105, secured by welding or the like, to the tubes 91 and the segment 97 of the drum. Thus, normally the various segments 97 are drawn inwardly by the spring 103 to reduce the diameter of the drum and facilitate the application of coils of wire thereto. After the coils have been applied to the drum, the various segments will be urged outwardly by the introduction of compressed air into the cylinders 101. For this purpose the inner end of each cylinder is connected by a flexible hose line 106 with a manifold 107 mounted at the end of the shaft 63 and secured by welding or the like, to a ring 108a which in turn is secured by Welding or the like, to the outer face of an annular member 108 surrounding the shaft 63 and welded to the six tubes of the right hand group (FIG. 6). A quick connection fitting 109 disposed centrally of the manifold 107 provides for the connection of a hose line from any suitable source of compressed air. This serves to introduce air under pressure into each of the six cylinders 101 and thus causes the pistons therein to move radially outwardly from the axis of the shaft 63 against the action of the springs 103. In this way the diameter of the coil retaining drum is increased to the desired extent to grip the inner surfaces of the coils and hold the latter against turning relative to the drum. When it is desired to retract the various segments of the drum a manually operable valve 110 on the manifold may be opened to release the air from the various cylinders 101 to the atmosphere. The springs 103 will then retract the segments to the desired extent and the valve 110 will then be closed by the operator. It will be understood that the expansion and contraction of the drum in the manner explained will take place at the station designated C in FIG. 1.

It has been found desirable, in a construction adapted to carry three coils on the segmental drum, eaolr coil weighing 360 lbs., to provide the air cylinders 101 with a bore of 3" thus providing an effective area on the piston of 7.07 sq. inches. The stroke of each piston may suitably be 1% inches. Air supplied to the cylinders under a pressure of 90 lbs/sq. inch will provide each cylinder with the capability of exerting 635 lbs. of force on the segment connected with the piston. This is more than adequate to take care of the weight of the three coils mentioned since at least two segments will be effective at any time to exert the desired lifting component of force. Preferably, however, the drum is so positioned at the time it is at station C that one segment will be at the top of the drum, as shown in FIG. 5, so that this segment will exert its force upwardly while the two adjacent segments will exert a substantial upward force.

A housing 111, preferably formed of lightweight, noncorrosive sheet metal, is preferably provided over the brake drum and the brake operating mechanism as shown in FIGS. 6 and 7. This is to protect the brake mechanism during periods of rain and the like. The bottom of the housing preferably has an opening 112 to provide for the circulation of air and thus prevent overheating of the brake mechanism.

It will be seen from the foregoing that the invention provides an expeditious way of laying wires across a bridge structure for incorporation in the various strands of the suspension cables therefor. It eliminates the necessity of large drums of wires to be transported to the site of the bridge and eliminates the need for the bulky unreeling mechanism heretofore employed. A single dead wire is payed out from a supply of reasonable Weight carried across the bridge structure under the required tension, say lbs., to cause it to assume the desired catenaries. Adjustment of the wires so laid may be very expeditiously effected during the period in which the supply of wire on the carrier is being replenished and the carrier is moved around the turn-around loop. While a certain amount of slack may be produced in the wire from the drum on the carriage as thelatter is shifted around the turn-around loop, this may be taken up readily by turning the drum while the brake is not being applied. If desired, however, the slack may simply be taken up as the hauling rope moves the carriage a relatively short distance on its return to the opposite end of the bridge structure.

While a preferred embodiment of the invention has been described in considerable detail, it will be understood that var-ious modifications may be made in the form and arrangement of the devices and structures employed and in the sequence of steps followed, without departing from the invention as defined by the appended claims. To expedite the forming of the cables, moreover, provision may be made for carrying several dead 1 1 wires acros sthe bridge structure at the same time. Thus, separate coil carrying structures of the character herein disclosed may be simultaneously employed for the production of the two cables required. In such case the entire structure herein disclosed will be duplicated in the region of the second cable to be laid.

What is claimed is:

1. A method of spinning a parallel wire cable for suspension bridges and the like which comprises anchoring the free end of a supply of wire adjacent one end of the desired cable, carrying said supply of wire along a path conforming substantially with the contour of the desired cable and paying out wire from said supply as the latter advances, applying frictional resistance to the delivery of Wire from said supply to apply a tension thereto between the anchorage therefor and said supply to eliminate slack as the wire is delivered from the supply and to maintain the wire along the desired path of the cable, anchoring a portion of said wire at a point adjacent the opposite end of the desired cable, and returning said supply of wire to a point adjacent said one end of the desired cable along a path conforming substantially with the contour of the desired cable While said frictional resistance is applied to the delivery of the wire from said supply.

2. A method of spinning a parallel wire cable for the purpose and in the manner set forth in claim 1 in which a portion of said wire is anchored at a point adjacent the anchorage of said free end of the wire after said supply has been returned to said point, and in which said supply is carried again to said opposite end of the desired cable and another portion of the wire is anchored adjacent said opposite end of the cable, returning said supply of wire to the initial end of said cable, and repeating said steps until a sufficient number of wires have been laid to form a desired strand.

3. A method of the character set forth in claim 2 in which said supply of wire is moved around a looped path at each end of the desired cable to turn said supply through an angle of 180 about a vertical axis.

4. A method of the character set forth in claim 2 in Which each wire as it has been payed out and laid from said supply is adjusted to its desired length before it is anchored at the end of the desired cable to which it has been carried.

5. A method of the character set forth in claim 2 in which one or more new coils of wire are added to said supply adjacent at least one end of the desired cable, and in which selected free ends of the wires in the previous and added coils are connected together to form a continuous single wire to be delivered from said coils in succession.

6. A method of the character set forth in claim 1 in which said wire supply is in the form of coils adapted to be mounted on a revolvable drum and in which the diameter of said drum is decreased at the time the coils of Wire are applied thereto and increased prior to the movement of the drum to pay out Wire.

7. Apparatus for laying Wires for incorporation in a suspension cable for bridges and the like which comprises a track strand fixedly mounted along a path having approximately the catenary contour of the cable to be formed, a hauling rope mounted for movement along a path below that of said track strand, means for moving said hauling rope along said path, a carriage mounted for movement along said track strand and provided with means for supporting coiled wire, means for connecting said carriage with said hauling rope to cause movement of the carriage along said track strand, said last-mentioned means being releasable to disconnect said carriage from said hauling rope, means for anchoring the free end of wire drawn from the coiled Wire on said carriage at a point adjacent one end of the cable to be formed, and means for applying a frictional resistance to the delivery of wire from said coiled Wire as said carriage is moved along said track strand.

8. Apparatus of the character set forth in claim 7 in which means is provided for readily releasing and reapplying said frictional resistance.

9. Apparatus of the character set forth in claim 7 in which said means for supporting coiled wire comprises a segmental drum, and means for moving the se ments of said drum in a radial direction to increase and decrease the diameter of the drum.

10. Apparatus for laying Wires for incorporation in a suspension cable for bridges and the like which comprises a plurality of track strands fixedly mounted along substantially parallel paths having approximately the catenary contour of the cable to be formed, an endless hauling rope having a course thereof below each of said track strands, means for shifting said rope lengthwise along said courses, a carriage mounted for movement in one direction along one of said track strands and then in the opposite direction along another of said track strands, means on said carriage for supporting coiled wire, readily releasable means for connecting said carriage with the course of said hauling rope beneath said one of said strands to move the carriage along the latter and for subsequently connecting said carriage with the course of said hauling rope beneath the other of said track strands when the carriage is mounted for movement thereon, means for anchoring the free end of wire drawn from said coiled wire on said carriage at a point adjacent one end of the cable to be formed while the carriage is adjacent said point, means for anchoring a portion of the wire payed out from said coiled wire when the carriage reaches the opposite end of the cable to be formed, and means for applying a fricional resistance to the delivery of wire from said coiled wire as said carriage is being moved by said hauling rope.

11. Apparatus of the character set forth in claim 10 in which a looped rail is provided adjacent each end cf the cable to be formed, said rail at each of said ends being arranged to receive said carriage from one of said track strands and deliver said carriage to the other of said track strands.

12. Apparatus of the character set forth in claim 11 having automatic means for releasing said releasable means for connecting said carriage with said hauling rope in regions adjacent the points of transfer of the carriage from the track strands to said looped rails, and automatic means for connecting said carriage to said hauling rope in regions adjacent the points of transfer of said carriage from said looped rails to said track stands.

13. Apparatus of the character set forth in claim 12 in which said releasable means for connecting said carriage with said hauling rope comprises a lever, and said automatic means comprises a cam positioned in each of the recited regions, and means carried by said lever cooperating with said cams for successively releasing and connecting said carriage from and with said hauling rope.

14. Apparatus of the character set forth in claim 10 in which means are provided for automatically operating said means for applying frictional resistance to the delivery of said wire to thereby apply and release tension on said wire at predetermined positions in the path of movement of said carriage.

15. Apparatus of the character set forth in claim 14 in which said means for operating said means for applying frictional resistance to the delivery of said wire comprises an air actuated member and a source of compressed air, a valve for controlling the delivery of air from said source to said air actuated member, a lever connected with said valve for operating the same, and cam means positioned along the path of movement of said carriage arranged to cooperate with said lever to operate the same and said valve to control the delivery of air to said air actuated member and the discharge of air therefrom.

16. Apparatus of the character set forth in claim 10 in which said means on said carriage for supporting coiled Wire comprises a drum adapted to receive and retain a plurality of coils of wire having the ends of the wires in the several coils connected together to form a single continuous wire, said coils having such frictional engagement with said drum as to prevent turning of said coils relative to said drum. a

17. Apparatus of the character set forth in claim 16 in which said drum is formed by a plurality of segments adapted for radial movement in relation to the axis of said drum, and means for moving said segments radially of the axis of said drum to decrease or increase the diameter of said drum to thereby facilitate the application of coils of wire thereto and thereafter establish sufficient friction between said coils and said drum to cause the same to turn together without slippage.

18. Apparatus of the character set forth in claim 17 in which said means for moving said segments radially of the axis of said drum comprises a cylinder for each segment extending radially from the axis of said drum, means for retaining the cylinders for all of the segments in fixed position relative to the axis of the drum, a piston in each cylinder having a connecting rod extending outwardly therefrom and connected with the related segment and means for introducing air under pressure into each of said cylinders for forcing said pistons and the connected segments in at least one direction.

19. Apparatus of the character set forth in claim 17 in which said pistons are adapted to move said segments in one direction, spring means for moving said pistons and segments in the opposite direction, and valve means for locking air under pressure within said cylinders and for releasing the air therefrom when desired.

20. Apparatus of the character set forth in claim 11 in which a turntable is provided adjacent at least one of said looped rails, said turntable having horizontally extending arms adapted to receive coiled wire and convey the same to a position substantially parallel with an adjacent portion of the looped rail, thereby enabling ready transfer of said coiled wire to said carriage when the latter is at said portion of the looped rail.

21. Apparatus of the character set forth in claim 20 in which said means on said carriage for supporting coiled wire comprises a drum adapted to receive and retain a plurality of coils of wire having the ends of the wires in the several coils connected together to form a single continuous wire, said drum being formed of a plurality of segments mounted for movement in directions toward and away from the axis of the drum, and means for moving said segments toward said axis when the carriage is at said portion of the looped rail to facilitate transfer of new coils from said turntable to said drum and for thereafter moving said segments away from said axis to cause said segments to forcibly engage the inner surfaces of all of the coils mounted thereon.

22. Apparatus of the character set forth in claim 21 in which means are provided adjacent said portion of the looped rail for connecting the free ends of the wire of the coils previously applied to the drum and of the new coils applied to the drum so as to provide a single continuous wire.

23. Apparatus of the character set forth in claim 21 in which the means for applying a frictional resistance to the delivery of wire from the coils of wire comprises a brake drum, a brake band surrounding said brake drum,

and means connected with said brake band for urging it into frictional engagement with said brake drum around the major portion of'the circumference of the latter.

24. Apparatus of the character set forth in claim 23 in which means are provided for forcing said brake band out of frictional engagement with said brake drum, said last-mentioned means comprising an air cylinder and piston, a container for air under pressure mounted on said carriage, a conduit connecting said container with said piston, and a valve in said conduit for controlling the delivery of air therethrough.

25. Apparatus of the character set forth in claim 24 in which said valve is provided with an operating lever, and fixed means along the path of movement of said carriage adapted to engage said lever to operate the same as the carriage is being advanced.

26. Apparatus of the character set forth in claim 25 in which said valve and said lever may be operated in opposite directions from a normal position, means for urging said valve and lever into such normal position, said valve having port means, said port means being closed off when said valve is in its normal position, said port means being arranged to place said container in communication with said cylinder when said valve is shifted in one direction from its normal position and to place said cylinder in communication with the atmosphere when said valve is shifted in the opposite direction from its normal position.

27. Apparatus for spinning a parallel wire cable for suspension bridges and the like which comprises means for anchoring the free end of a supply of wire adjacent one end of the desired cable, means for carrying said supply of wire along a path conforming substantially with the contour of the desired cable and for paying out wire from said supply as the latter is carried along said path, means for applying frictional resistance to the delivery of wire from said supply to thereby apply a tension to the wire between the anchoring means therefor and said supply, said last-mentioned means being adapted to apply sufficient frictional resistance to eliminate. slack as the wire is delivered from the supply and to maintain the wire along the desired path of the cable, and means for anchoring a portion of said wire at a point adjacent the opposite end of the desired cable, said second-mentioned means being constructed and arranged to return said supply to a point adjacent said one end of the desired cable along a path conforming substantially with the contour of the desired cable while said means for applying frictional resistance to the wire is active.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Construction Methods and Equipment, March 1956, pages 58-63.