US2741372A

US2741372A - Slack line carrier

Info

Publication number: US2741372A
Application number: US259187A
Authority: US
Inventors: Richards Dwight
Original assignee: Guy F Atkinson Co
Current assignee: Guy F Atkinson Co
Priority date: 1951-11-30
Filing date: 1951-11-30
Publication date: 1956-04-10
Anticipated expiration: 1973-04-10

Description

p MB, 395)@ n. RcHARQs SLACK LINE CARRIER 5 Sheets-Shea?, l

Filed Nov. 30, 1951 INVENTR. @wfg/77l Richards TTORNEYJ' p w, QS@ D. Ram-mans sLAcK LINE CARRIER 5 Sheets-Sheet 2 Filed NOV. 30, 1951 PI' 10, 1956 D. RICHARDS 2,741,372

SLACK LINE CARRIER Filed Nov. 30, 1951 5 Sheets-Sheefl 3 F* E.. E

"V5 /Z y- 4 April 10, 1956 D. RICHARDS 2,741,372

sLAcK LINE CARRIER Filed Nov. so, 1951 5 sheets-sheet 4 J/QVQM@ United States Patent *i SLACK LINE CARRIER Dwight Richards, Portland, Greg., assignor to Guy F.

Atkinson Company, San Francisco, Calif., a corporation of Nevada Application November 3l), 1951, Serial No. 259,187

S Claims. (Cl. 212-120) This invention relates generally to slack line carriers suitable for use with cable way systems of the suspension type.

In conventional cable way systems of the suspension type a main carrier cable is extended between horizontally spaced supporting towers, and serves to support and track a main operating carriage. An additional endless cable extends between the towers and is attached to the carriage for traversing the latter along the main cable. Also a hoist cable is extended from the cable tower to the main carriage, and is reeved over sheaves on the main carriage and on a traveling block assembly, to provide for raising and lowering a load. Cable systems of the type just described (known as Vtelphers) are used on large scale construction projects, as for example for transporting concrete from a batch mixer to the various sections of a dam under construction. in the operation of such cable systems that part of the hoist cable which extends from the main carriage to the cable tower becomes slack t after a load has been discharged, and while the main carriage and the concrete hopper are being maneuvered back to a position for receiving another batch of material. Unless special support means is employed, excessive slack may interfere with operation of the system and may cause the hoist cable to become fouled. in the past, slack carriers have been used to provide such support. Each carrier consists of a frame which is tracked upon the main cable and which carries one or more sheaves for engaging and supporting the hoist cable. A plurality of such carriers are applied to the main cable, on one or both sides of the main carriage. ln order to maintain a desired spacing between the carriers, as the main cable is traversed between the towers, a separate button line has been employed, which is arranged to pick up the slack carriers successively, and thus distribute them at regular intervals along the main cable. When the main carriage is traversed over a length of main cable along which carriers have been distributed, the carriers are racked or lodged successively upon the advancing end of the carriage, and in position to be picked up successively by the button line when the carriage is moved again in the opposite direction.

A slack carrier arrangement of the type described above has several disadvantages. Both pickup of the carriers by the button line, and racking of the carriers upon the advancing end of the main carriage, involveimpacts and shock forces of considerable magnitude. This places a serious limitation upon tne speed of movement of the main carriage which can be attained in actual practice. ln addition, it causes considerable mechanical wear and general deterioration of the equipment.

It is an object of the present invention to provide an improved slack line carrier for cable systems of the above character, which will overcome the above described disadvantages of prior arrangements.

Another objectof the invention is to provide a slack line carrierwvhich will make possible higher speeds of operation of the main carriage without involving severe v impact forces.

Another object of the invention is to provide a slack line carrier which will automatically distribute itself along the main support cable, without the use of a button line or like positive pickup means.

Another object of the invention is to provide a slack line carrier which will more adequately support the hoist line, and which when a number of such devices are used will cause automatic distribution over the length of the line extending from the main carriage to one or both of the support towers.

Additional objects of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 is a side elevational view illustrating a slack carrier incorporating the present invention.

Figure 2 is a cross-sectional view taken along the line 2-2 of Figure l. t

Figure 3 is a cross-sectional view taken along the line 3-3 of Figure l.

Figure 4 is a cross-sectional view taken along the line 4 4 of Figure 3.

Figure 5 is a schematic diagram illustrating application of a plurality of my slack carriers to a cable hoist system.

Figure 6 is a side elevational View illustrating another embodiment of the invention. v

Figure 7 is an enlarged cross-sectional view taken along the line V7--7 of Figure 6.

The slack line carrier illustrated in the drawing consists generally of a frame 10 which carries the working parts. Figure l illustrates the carrier in conjunction with three lengths of cable, namely the main support cable 11, the haul or endless cable 12, and the hoist cable 13. The main cable 11 is stretched between the cable and anchor towers, and serves to support and track the main carriage of the cable system. ri`he haul cable 12 is made endless, with its lower run attached to the main carriage. At the anchor tower the end loop of the haul cable passes over suitable sheaves, and at the cable tower it passes over supporting sheaves and also winch drums whereby the haul cable can be operated to move the main carriage to any desired position between the supporting towers. The upper run of the haul cable is not illustrated in Figure 1, and is generally at a considerable elevation above the main cable 11.

The hoist cable 13 extends from an operating winch at the cable tower to the main carriage. It is reeved over sheaves on the main carriage, and over sheaves carried by a traveling block, whereby upon winding up or playing out this cable from the cable tower, the load can be raised or lowered as desired. In some instances one end of this cable is dead ended upon the main carriage, and in other instances it is extended for dead ending upon the anchor tower.

The frame 10 consists of side fabricated structural members l16, which are cross-connected by the upper and

lower members

17 and 18. At the upper end of the frame there is a main sheave 19, which is iixed to the shaft 21. Bearing assemblies 22 serve to journal the shaft 21 in the side structural members 16. The periphery of the sheave 19 is grooved to track upon the',

3 beams 24 are Vseclned to the tubular Vmember 26, which is carriedl by the shaft 27. The side members 16 of the frame have slots 23 which accommodate the shaft 27, and thus permit this shaft, together with the beams 24, to move toward or away from the sheave 19. l

Suitable spring means is arranged to apply forces to Vthe extremities of the shaft 27, and to thereby urge the sheaves 23 against the underside of the main cable.Y In Figure 3 of the drawing the spring means is designated generally at 29 and will be presently described in detail.

ln order to guide and prevent cockingl'of the shaft 27, it isV shown carried by a pair Yof guide blocks 31, which in turn engage the guideways 32. The guideways are mounted upon the side member 16, and serve to retain the shaft 27 perpendicular to a plane corresponding to the plane of rotation of the sheave 19, while at the same time permitting limited movement of the shaft toward vor away rorn the slieave 19. The spring means 29 serves to urge the ushaft 27 upwardly, whereby the sheaves 23 are continuously urged against the lower side of the main n cable at 11. The -normal position of the sheaves 23 is illustrated in Figure l. lt will be evident that the arrangement thus described tends to prevent turning of the carrier about a vertical axis, and in addition tends to prevent oscillating movements in a vertical plane coincident with the main cable.

Below the sheave19, the frame supports another sheave 33 (Figure 3) which has a grooved periphery adapted to engage the lower side of the haul cable 12. Sheave 33 is carried Vby the shaft 34, which in turn is journaled to the frame by bearing assemblies 36.

Additional sheave means is provided for engaging the cable 12, and for retaining this cable in irictional driving relation with the sheave 33. rl`hu`s a pair of spaced paral lel beams 37 extend between the side frame members below the'beams' 24, and serve to carry sheaves 38 that engage the upper side of the cable 12. The medial portions of the beams 37 are secured to the tube 39, whichis carried by the shaft 41." The shaft extends through guide blocks 42, which engage the guideways 43. The extremities of shaft 41 are connected to the same spring means 29 as is employed for connection with the shaft 27.

The spring means 29 upon each side of the carrier consists in each instance of

telescopic casings

46 and 47, which serve to house the compression spring 48. The

casing 46 is secured to the hollow rod 49, which yin turn is secured to a hub 5l surrounding the adjacent end of shaft 27. The hollow' rod 49 is guided upon the rod 52, to which the casing 47 is attached, and which is secured to a'hub 53 upon'the adjacent end of shaft 41. lt will be evident that with this arrangement the compression springs 4S act in opposite directions upon theV telescopic casings 46 Vand 47, thus urging the shafts `27 and 41 in opposite directions.

At the lower end of the frame (Figures 1 and 2) there is a stirrup-like structure 56, which can be constructed as illustrated in Figure 2. Thus the structure includes two side members 57, the upper ends of which are journaled by roller bearing assemblies S8 with the shaft 59.

Shaft 59 is mounted upon the lower extremities of the frame member 16. A sheave 6i) is journaled to the lower ends of members 57, and serves as a supporting sheave for the haul line 13.

A drive connection is provided vbetween vthe sheaves 19 and 33, whereby when relative motion occurs between the haul cable. and themain cable, vthe entire carrier is caused to move along the main cable. The drive connection in this instance includes the two endless drive belts 61 (Figure l) which engage the'rupper and

lower sheaves

62 and 63. The upper sheaves62 (Figure 3) are secured to the extremities of the shaft 21, and therefore rotate with the sheave 19. The lower sheaves.v 63'are attached tothe extremities of the shaft 34, and rotate together withrthe sheave 33. The proportioning of the.

Y riage to the right.

sheaves

62 and 63 determines the drive ratio established.

Automatic means is vprovided for either establishing or interrupting the drive connection. Thus a portion of each belt 61, which extends between the

sheaves

62 and 63, is engaged by an idler 66 (Figures l and 4). Each idler is carried by a shaft 67 (Figure 4), which is secured to the spaced

arms

68 and 69. The

arms

68 and 69 have their lower ends secured to the end portions of a shaft 71,

and this shaft in turn extends through and is secured toV Ythe adjacent beams 37. The vfree ends of the arms 69 are attached by turnbuclrle links 72 to the tension springs 73. These springs are anchored to the brackets 74, which Vare carried by the remote ends of the beams 37. The tension springs 73 serve to urge theV idler sheaves 66 against the drive belts 61. v

The arms 68 are connected by links 76 with the arms 77. A rocker shaft 79 is carried by the adjacent ends of the beams 37 and serves to mount the arms 77. An operating arm or lever 31 -is also fixed to the Yshaft 79 and provided with a portion adapted to 'oc engaged for rorcing the arm 81 to the left as viewed in Figure-'1. The structure S3 (Figure 4) which forms a cross connection between the adjacent ends of the beams 37, also forms a bolster or bumper plate 84. A similar plate 86 is shown mounted upon the opposite ends of the beams 37 (Figure l).

With the drive arrangement described above, it will be evident Vthat a positive drive is provided between ythe sheaves V62 and 63 and between the corresponding cable engaging sheaves y19 and 33, for the position of the operating parts illustrated in FigureV Il. Under such conditions when the haul 'cable V,12.is pulled toward the right as viewed in Figure l, resulting rotation of the sheave 33` causes rotation of the sheave 19 torrnove the entire -car- The rate of movement, relative to the rate of movement of the cable `12, is dependent upon the 'drive ratio established between the sheaves '19 and 33, and .this in turn is determined by the relative diameters of the

sheaves

62 and 63. When the'carrierengages an adjacent abutment, which may be an abutment upon uthe main carriage, for uponanother slacit carrier, arrn 81 is swung clockwise as viewed Vin vFigure l, with the result that the idler sheaves 66 are swung toward the right against the tension of the springs 73, and this in turn loosens the drive belts 61 in order to permit substantially free slippage betweenthe belt and the

sheaves

62 and 63.

The drive is now interrupted and movement of the cable 12 under such conditions does not cause movement of Assuming that the position ofthe carriage 4 is such that it is adjacent the anchor tower, the carriers 1, 2 and 3 Y will be spaced apart and distributed between thecarriage andthe cable tower. Their location will be such that they Aadequately support the hoist cable 13 when this cable is slack. As the carriage 4 moves to the left from the position shown in Figure 4, each of the carriers 1, 2

and 3 also moves to the left, because of the positivev drive connection between the

sheaves

19 and 33 of each carrier. rate as great as that of the main carriage. Because of the dierent ratios employed for the drive connections the gaps between adjacent slack carriers decrease as the i main carriagerapproaches the cable tower. If no slip- Y page occurs between the yslack carriers and the `cables 11 and 12 the "slack carriers will 'be racked for Ahunched together 'at the advancing end of the main carriage,when

However none of the carriers will move at aV the main carriage reaches its extreme left hand position adjacent the cable tower. If however some slippage has occurred in such a manner as to tend to cause one or more of the slack carriers to slide toward the center of the system, then the drive connections of one or more of the slack carriers are interrupted as it is engaged by another carrier or by the carriage, and this carrier is then moved in unison with the carrier or main carriage with which it may have engaged. Por example if the main carriage engages the slack carrier 1, before the above mentioned limiting position has been reached, the drive connection of carrier 1 is interrupted, and thereafter carrier 1 is pushed along the cable 11 by the main carriage, until the main carriage reaches its above mentioned limiting position. When the carriage returns to- Ward the center of the system, or toward the opposite tower, the drive connection of slack carrier 1 is immediately reengaged, so that this carrier then again takes its individual movement along the main cable, to maintain a desired distance from the main carriage, and from adjacent carriers. If the slack carrier 2 should slip toward the middle of the system, without corresponding slippage taking place in the carrier 1, then carrier 2 will be picked up and moved along in the same manner by the carrier 1, without automatic disruption of the drive connection of carrier 1.

In the foregoing explanation reference is made to an arrangement of slack carriers upon only one side of the main carriage. It will be evident that similar slack carriers can be used upon the other side of the main carriage, particularly where the hoist cableextends from the main carriage to both the anchor and cable towers.

My slack carrier has many advantages over the arrangements which have been used in the past. The carriers are distributed by virtue of their drive connections, and without the necessity of abruptly accelerating the successive carriers. No pick-up action is required except insofar as slippage occurs between carriers and the cables, and under such conditions the drive connection of a carrier is interrupted so that the carrier is free to move back to its normal position. The advantages thus described make it possible for a cable way system equipped with my slack carriers to be operated at relatively high speed, compared to the speeds previously employed with conventional arrangements.

In the embodiment of Figures 6 and 7, the belt drive means is eliminated, and a gearing of the planetary type serves to connect the two sheaves which engage the main and haul cables. Also in this embodiment the sheaves are concentric and a number of the constructional details have been simplied. The main frame 91 in this instance is formed of the side vertical frame members 92, which are suitably interconnected by cross members. The upper ends of the frame members 92 are directly secured to the beams 93, which carry the tracking sheaves 94 for engaging the main cable 11. Beams 96 carry the sheaves 97, which engage the cable 12. Beams 96 are connected at their ends by cross members 9S, and their central portions are pivotally secured to the blocks 101, which in turn are slidably carried by the side frame members, and are urged upwardly by the compression spring assemblies 102.

The underside of the main cable 11, between the sheaves 94, is engaged by the sheave assembly 103. Housed within this assembly there is a second sheave 104, which operatively engages the cable 12. Both the sheave assembly 103 and sheave 104 are mounted upon a common shaft 106, together with elements of a planetary interconnecting gearing.

The sheave assembly 103 consists of two halves 103a and 1031:', which are dished, and which have peripheral portions 107 in spaced opposition to engage the main cable 11 and permit the cable 12 to engage the sheave 104. The sheave part 103:1 is provided with a hub 108, which is journaled by roller bearing assembly 109 to 6 the shaft 106. Hub 10s is also secured to the hub 11i of a gear 112, and hub 111 is journaled to the shaft 106 by the needle bearing assembly 113. An arm 114 is keyed to the shaft 106, and a shaft 116, journaled to the free end of this arm, carries the gears 117 and 118. Gear 117 engages the teeth of gear 112.

The sheave 104 is provided with a hub 119, which is suitably journaled to the central portion of shaft 106 by needle bearings 120. The hub also provides a gear 121 which meshes with the teeth of gear 118.

The hub 122 of the sheave half 103b is similarly journaled by roller bearing assembly 123 to the shaft 106. A gear 124 secured to this hub engages a gear 126, which is attached to the shaft 127. The latter is journaled to the free end of the arm 12S, and also carries a gear 129. Arm 128 is keyed to the shaft 106. Gear 129 engages a gear 131, which is secured to the hub of the sheave 104.

It will be evident that the arrangement described above provides two independent trains of gearing between sheave assembly 103 and sheave 104. When the two gear trains provide different drive ratios, by virtue of the diierent dimensioning of the gears, one of the gear trains can be disabled, as by the removal of one or more of the essential gears from the same. However if desired the trains can be of the same ratio and operated simultaneously.

The ends of shaft 106 are loosely carried by the blocks 101a, and these blocks are urged toward beams 93 by the compression spring assemblies 102:1.

As shown in Figure 6, the beams 96 are shown provided with the bumper lever 133, which has its arm 134 attached to the link 136. Notched annular members 137 are mounted upon the exterior ends of the shaft 106, and one of these members is adapted to be engaged by the sliding lock pin 138. This pin is spring urged toward engaged position and is connected to the adjacent end of link 136.

The apparatus illustrated in Figures 6 and 7 operates as follows: The two halves of the sheave assembly 103 engage and form a friction drive with the underside of the main cable 11. The cable 12 operates through the slot provided between the two sheave halves 102m and 10312, to engage the sheave 104. Assuming that the right hand gear train of Figure 7 is inactive, and assuming that the left hand notched member 137 is stationary by virtue of engagement with pin 138, rotation of sheave 104 by movement of the cable 12 causes the sheave assembly 103 to be rotated through the gear train, and at a drive ratio dependent upon the gear train design. When the bumper lever 133 is engaged in the manner previously described, the notched member 137 is released thus permitting the shaft 106 to be free to rotate. This interrupts the drive connection between sheave assembly 103 and the sheave 104, thereby securing the'same results as interrupting the belt --drive employed in the first described embodiment.

When one desires to use the 'drive ratio provided by the right hand gear train of Figure 7, then the left hand gear train can be disabled as by moving one or vmore essential gears, and other gear train is made operative. The right hand gear train now establishes a drive of a predetermined ratio between the sheave assembly k103 and 104, when the main shaft 106 is stationary.

The embodiment of Figures 6 and 7 is advantageous in that the elements of the gear train are completely housed within the sheave assembly 103. Thus the use of exposed drive elements such as belts and the like is obviated.

l claim:

l. A slack line carrier for cable systems of the type including a main load carrying cable extending between cable towers for tracking a main carriage, an endless haul cable for traversing the carriage along the main cable, and a hoist cable for supporting a load from the carriage;

the slack line carrier comprising a frame, means onY the frame for tracking the carrier on the main cable, said means including a pair of side by side half sheave lsections disposed in spaced opposition to lrotate about a common axis, the spacing between said sheave sections serving to accommodate the haul cable, additional means onV the frame for continuously tracking the carrier with respect to the haul cable, said last means including another sheave disposed between said half sheave sections and concentric therewith, drive means enclosed within said sheave 'sections for operatively connecting at least one of said sheave sections with said second named sheave member, means carried by the frame for supporting and Yretaining the hoist cable, and means for automatically disengaging said drive connecting means responsive to engagement of the carrier with an adjacent abutment.

2. A carrier as in claim 1 in which said last named means includes members disposed exterior of said sheave halves and adapted to be engaged or disengaged responsive to engagement of the carrier with an adjacent abutment.

3-. A slack line carrier for cable systems of the type including a main load carrying cable extending between cable towers for tracking a main carriage, an` endless haul cable for traversing the lcarriage along the main cable and a hoist cable for supporting a load from vthe carriage, the slack line carrier comprising a frame, sheave means on the frame for tracking the carrier'on the main cable including a sheave member in continuous driving engagement with the main cable, said sheave member being formed of two halves which each engage the main cable, additional sheave means on the frame for continuously tracking the carrier withrespect to the haul cable, said last means including another sheave member concentric with respect to said firstV named sheave member and being in continuous driving engagement with the Vhaul cable, drive means operatively connecting said sheave member for causing movement from the carrier along the main cable responsive to movementV of the haul cable relative to the main cable, means carried by the frame for supporting and retaining the hoist cable,

and means for automatically disengaging said drive connecting means responsive to the engagement of the carrier with an adjacent abutment.

4. A slack line carrier for cable systems of the type including a main load carrying cable extending between cable towers for tracking a main carriage, an endless 'haul cable for traversing the carriage along the main cable, and a hoist cable for supporting a load from the carriage; a slack line carrier comprising 'a frame, sheave means on the frame for tracking the carrier on'the main cable and including a sheave member in continuous driving engagement with the main cable, said sheave member being formed of two halves which eachengage the main cable, additional sheave means on the frame Vfor continuously tracking the carrier with respect to the haul cable, said last means including another sheave member concentric Vwith respect to said rst named sheave member and in continuous driving engagement with the haul cable, drive means comprising planetary .gearing for operatively connecting said sheave members for causing movement of the carrier along the main carrier responsive to move` ment of the haul cable relative to the main cable, means carried by the frame for supporting and retaining the hoist cable, and means for automatically interrupting said planetary ygearing in response to engagement of the carrier with an adjacent abutment.

5. A slack line Ycarrier -for cable systems of the type including a main load carrying cable extending between cable towers for tracking'a main carriage, an endless haul cable for traversing the carriage along the main cable,

and a hoist cable for supporting a 'load from the carriage;

the slack vline carrier comprising a frame, vsheave means on the Vframe for tracking the carrier on the main cable and including a driving sheave member mounted on one side of said maingcable and a pair of sheave members mounted on the opposite side of said main cable, Vsaid last named sheave members serving to maintain the driving sheave member in continuous driving engage` ment with said main cable, additional sheave means on the frame for continuously tracking the carrier with respect to the haul cable, said last named means lincluding a driving sheave member mounted on one side of said haul cable, and a pair of sheave members mounted on the opposite yside of said haul cable, the last named sheave members serving to maintain the last named driving sheave member -in continuous driving engagement with the hall cable, drive means operatively connecting said Vdriving sheave members for causing movement of the carrier along the main cable responsive to movement of the Vhaui cable relative to the main cable, means carried Yby the frame for lsupporting and retaining the hoist cable, and means Vfor automatically disengaging said drive connecting means responsive to engagement of the carrier with an adjacent abutment.

6. A slack line carrier as in claim 5 in which the twov driving sheave members are concentric with respect to each other.

7. A slack line carrier as in claim 6 in which the drive means comprises planetary gearing and in which the means for automatically disengaging said drive means consists of means for interrupting said planetary gearing.

8. A slack line carrier as in claim 5 in which the drive means comprises an endless drive belt of the type adapted to be tightened to establish avdrive connection between the driving sheave members and `to be slackened for disrupting the drive connection.

References Cited in the tile of .this patent UNITED STATES PATENTS