US1767768A - Car hoisting and dumping apparatus - Google Patents

Description

June 24, 1930. M. B. MCLAUTHLIN 1,767,758

CAR HOISTING AND DUMPING APPARATUS A June 24, 1930. M'. B, MCLAUTHUN :1,767,768

CAR HOISTING AND DUMINGy APPARATUS Filed Nov. 7, 1924 5 Sheets-sheetv 5 June Z4, 1930.

M. B. MCLAUTHLIN 1,767,768

GAR HOISTING AND DUMPING APPARATUS 5 Sheets-Sheet 4 i Filed Nov. 7, 1924 mamma@ www June 24, 1 930. M, B, MCLAUTHLIN v'1,767,768

CAR HOISTING AND DUMPING APPARATUS Filed Nov. Y, 1924 5 sheets-sheet '-5 Patented .lune 24, 1930 MARTIN B. MCLAUTHLIN, OF MALDEN, MASSACHUSETTS ICE CAR HOISTING AND DUMPING APPARATUS Application led November 7, 1924. Serial No. 748,418.

The present invention relates to machines hoisting and tilting mechanism by which deand apparatus for lifting and dumping sir-ed movements are given tothe car; freight cars, and more particularly side- Fig. is an elevation generally similar to door looX cars loaded with grain, or other Fig. l, but with omission of the hoisting 5 material, which will pour out of the open mechanism and illustration of only the car- 55 door when the car is tilted. More particudoor opener and the means for operating larly the type of apparatus to which this rinthe same; l vention relates is that shown in the patent to Figs. 6, 7, and 8 are details of a part of the Lionel Coke Hill, granted February 20, car-door opener; Figures 6 and 7 showing 1923, No. 1,446,303, which discloses the printhe same parts in respectively different posi- 60 ciples of means for lifting and tipping a car tions, and Figure 8 being a cross section on sidewise, and then while it remains in the liIleS-Sof Figure 7 Y tipped position, tilting or rocking it back Fig'. 9 1S a plan view enlarged showing a and forth lengthwise to cause the material part of the hoisting mechanism, and the in the ends of the car to flow toward and out driving mechanism for the door opener; 65 of the door- Fig. 10 is an elevation of the drive for the The embodiment of my invention Chosen door opener, and a control switch operated for illustration herein is an improvement in thereby; apparatus of the type shown in said Hill Figs. 11, 12, 13, 14, and 15 are details of a patent, designed to secure greater lifting C1lll3Cl1-C01ltfOllerby which the door opener 70 power with elimination of unbalanced drive 1S made active or inactive; thrusts on the lifting mechanism, and great- F 1g. 16 1S a detail elevation of one of the er elliciency in both lifting and tilting tilt drums Showing my novel mode of conoperations. Such improvements, together HGCtiIlg 2L COllHelWelght thereto. with certain new constructions and combi- Llk@ Tete'enc@ Characters designa-t@ th@ nations of mechanism which contribute to Sam@ PlltS Wherever they OCClir in all the the accomplishment of my objects, are shown lguesin the drawings filed herewith and are de- The. 0&1 t0 l0@ @lumped 1S lSt ruil onto an scribed in the following specification. The ettvtttlng Plattlma'and thelatte' 1S then invention consists not merely in such imfamed: ttpped S1CteW1S md tllted 01' @Glied 80 provements and novel mechanisms in the .longlttldlna/HY' F01' the PUFPOS@ Ot thlS de. embodiment herein illustrated, but also all SClPtlOn I Wlu use the Word tip and Vattthe equivalents thereof containing the same atttms thereof t0, indicate the motttm by prjncples as will 110W more fully appear. which the car is inclined sidewise and the In the drawings above referred to Figure WO'd tuta With its Variations t0 destgnat@ S5 l is a side elevation of an apparatus emhodyttl@ motion t action ndnng the Gardent-23th ing my improved car dumping means, illus- WlSe by misma@ .one end and lowelimg the trating in a diagrammatic manner the essen- (Ether end" Ehe plattrm as l Whole 1S deglg' tial elements and characteristics thereof, and latec QO and mayhbe of the. Same Construcl 90 omitting structural details which, although 10H s SOWm m t e Sad H111 patent or or 1, f any other suitable construction. Preferably Omttlgtgngntlot mVOlVQ the it is normally supported overa pit 22 on 7 Fi 2 is n n, t. f th abutments 2323,24-24, and it carries rails g' Q Che-QV? lonf 6Jplatt' 25 in alinement with receiving and discharge WFLS@ @en l @mt @mgmt Flgl racks, on which the car to be dumped may 95 1g- 315 tt Vle/W Slmltal' t0 Elg 2: but Show' be run. Such a car is shown in the drawings ing tne elevating platform, with a car theremd is designated 26, on, after having been raised, tipped sidewise, A superstructure or deck, designated as a andtilted endwise; whole by the numeral 27, is provided to sup- Fig. 4 is a plan view of the improved port the hoisting mechanism, and is located 100 Cil high enough above the normal position of the elevating platform to give room for the movements required to dump the car. The superstructure may be of similar construction and supported by similar means to those shown in the Hill patent aforesaid, or it may be of any other character and construction suitable to the situation in which any particular dumping apparatus may be installed. As the details of this part of the apparatus may vary widely according to the conditions of use, and may be designed to fit the circumstances according to well understood principles of structural engineering, I have deemed it unnecessary to illustrate or describe in detail any specific structure, further than 4to say that l prefer to use as the means for mounting and supporting the drums and pulleys of the hoisting mechanism, beams composed of channel irons or I-beams placed in parallel with spaces between them to receive the bolts which secure bearing boxes, or equivalent mounts, for the shafting and the trunnions of the hoisting drums and pulleys.

The platform 2O is raised and tipped sidewise by means of four drums, arranged in forward and rear pairs with the members of each pair near opposite ends of the platform, and cables, driven in unisonV by one motor, which for the purpose of this description l call the lifting motor, shown at 28 in Figure 4. Tilting of the platform is effected by two drums, through the same cables, driven by a second motor 29, which for present purposes I call the tilt motor. Both motors are preferably electric, of any desired type or make, having sufficient power for the purpose. The forward hoisting drums are shown at 30 and 3l in Figures l and 4, and the drum 30 is also shown in Figure 9. The rear drumsare shown at 32 and 33 in TFigure 4 They are of larger diameter or operate kat greater peripheral speed, or both than the forward drums in order that the cables wrapped about them will loe taken up faster than the cables taken up by the forward drums, and thereby the platform will be tipped at the same time that 'it is raised.

VThe lifting motor drives a longitudinal shaft 34 which in turn drives a transverse shaft 35 by means of a worm and wheel mechanism 36, and drives a second transverse shaft 37 by means of a worm and wheel mechanism 38. These worm and wheel mechanisms are here shown as being encased, but it will be apparent that the worm in each mechanism is mounted on the shaft 34 and the worm wheels on the shaft 35 and 37 respectively. One of the worm gearings is lefthand and the other is righthand in direction, and thereby the end Y thrusts of the hoisting mechanisms at opposite ends of the apparatus on the shaft 34 and the motor, are substantially balanced, making it unnecessary to provide heavy thrust bearings and avoiding all the friction losses due to such a bearing. This is one of the important novel features of the invention.

The shafts 35 and 37 extend across the apparatus and each drives the two hoisting drums at one end of the apparatus by means of a spur pinion and internal gear drive. Each drum carries a large internal gear 39 which meshes with a pinion 40 on the shaft, this type of gearing having the advantage of strength, in that more teeth of the couple are in mesh at the same time than in the case of an external gear couple of the same ratio.

The motor 29 drives, by means of a wormA -nd gear couple 4l of the same character as the gear couples 36 and 38, a transverse shaft 42 which in turn drives the tilting drums 43 and 44 by means of internal gear couples like those liust described.

The cables for hoisting and tilting the platform are arranged as follows. To the drum 30 is secured one end of a cable 45, the anchorage point of this cable being indicated conventionally at 46. This cable passes downward from the drum and around the under side of a sheave 47, connected to the platform, thence upward in a stretch designated 45a and around a guide pulley 48 on the superstructure, thence downward in a str tch 45b and aro-und a sheave 49 parallel .to the sheave 47 and connected to the platform, thence upward in a stretch 45c over a guide pulley 50, and then over to the drum 43, to which it is made fast after being wrapped a suflicient number of times around this drum'. r)lie anchorage point of the cable 45 on dr m 43 indicated convention ally 5l in Figure 4. The sheaves 47 and 49 may be mounted in a single block, or they may be separately connected to the platform.

A similar cable 52 is anchored to the drum 3l at the point 53, and passes downward under a sheave 54 attached to the platform, thence upward in a stretch 52L and around a fixed guide pulley 55, thence downward in a stretch 52b and under a second sheave 56 attached to the platform behind sheave 54, and thence yupward in a stretch 52c to the drum 43, to which it is anchored at the point 57 after being wrapped several times around this drum. l

A. cable 58 similar' to the cable 45 is wrapped about and anchored at its opposite ends to the drums 32 and 44, and passes around a series of sheaves and guides 59, 60,

6l, and 62, like the pulleys and guides 47, 4S, 49, and 50 respectively; and a fourth cable 63 is wrapped about and anchored to the drums 33 and 44, and passes around sheaves G4, and a guide pulley 66, which are like in arrangement and function tothe sheaves 54, 56 and guide pulley 55, respecthe platform, and by which, in connection with the speed-reduction gearing provided in the worm and wheel couples and the internal gear and pinioncouples, a high speed motor of moderate size and weight can be used in. handling the heavy load consisting of the platform with a kloaded car upon it. The loaded car may have a weight of as much as one hundred thousand pounds or more, and the platform may weigh as much as fifty thousand pounds in order to give ample strength and stiffness.

Counter' weights are suspended from each of the lifting drums. The weights 69 and 70 at the front side of the vapparatus are hung at the ends of cables 71 and 72 respectively, wrapped about and anchored to the drums 30 and 3l respectively. The counter f weigl ts 73 and 74 at the rear of the apparatus are each suspended in the bight of a cable. Cable 75 suspending weight 73 is anchored at one end at the point- 7 6 (Figure 4) to the superstructure, and its opposite end is Wrapped about yand anchored at the point 77 to drum 32, and the suspended bight of the cable passes under a sheave 78 attached to the counter weight. The cable 79 for the counter-weight 74 is anchored in a similar way at 8O to the superstructure and at 8l to drum 33, passing under a sheave 82 connected to the weight. As a result of thus suspending the counter weights from the lifting drums, the forward weights exert a z four-fold advantage in counter-balancing the load, and the rear weights exert a twofold advantage; which makes possi le the use of weights at the front side only onefourth as heavy as the proportion of the load which they are respectively called upon to balance, and the rear weights only onehalf as heavy as the para of the load which they respectively balance. It is within my contemplation also to suspend all the counter weights in the same manner as either the forward or the rear weights are here shown to be suspended.

The effort exerted by the drums 43 and 44 in tilting the load is also counter balanced by weights, and in order to explain the manner in which these counter balancing weights act, and a new principle of counter weighting which is embodied in this feature of the invention7 I will now briefly describe the mode of operation by which the appathe transmis- ,sion of power from the hoisting motor to ratus lifts and tilts the load.` When lifting, the lift motor 28 alone is put into action and the tilt motor 29 is left inactive and locked, by whatever braking or other locking means may be provided, to prevent turning of its shaft. Consequently the tilting drums 43 and-44 are locked. They then provide the necessary stationary abutments or anchorages for the lifting cables in order that such cables, when wound up on the drums 30, 31.l 32 and 33, may raise the platform. During the lifting action, the rear drums take up the cables faster than the forward drums, so that,'when the platform has been raised to the predetermined height, vits supporting part is tipped forward although it remains horizontal in its long dimension. ln other words the rearward one of the rails on which the 'car stands is raised to a higher level than the forward rail, but each rail is horizontal. Of course the platform is not tipped enough to overturn the car; and l may, if it is desirable to do so, provide any suitable means for holding the car down on the platform so that it will not overturn even if its center of gravity should be brought by tipping7 outside of the wheel base. TWhen the load has been raised to the prescribed height, the lift motor 28 stopped and locked, by a suitable brake or otherwise, and the lifting drums are thus locked. Then the tilt motor is set in motion and drives the drums 43 and 44 in unison. Assuming that the direction first given to these drums is right hand rotation, the cables 45 and 58 are further wound up on the drums and the cables 52 and 63 are paid out in the same measure. rlhis action causes the left-hand end of the platform to be raised and the right-hand end lowered (with reference to the View shown in Figure l), the load being then brought into the position shown by broken lines in Figure l, and the only position shown in Figure 3. The grain in the high end of the car will then slide toward the low endA` and much of it will fall out of the open side door, but some will go past the door, while of course all that was originally in the low end will remain there. Then by reversing the tilt motor the cables 52 and 63 are taken up and the cables 45 and 58 paid out, whereby the load is given the reversed tilt, and a similar flow of grain takes place from the end of which is now raised. Thisv alternate tilting may be repeated as many times as needed to empty the car. i

The tilt counter weights are connected to the tilting drums in such a manner that they exert no effort when the longitudinal dimension of the load is horizontal, that is when the tilt'A ig drums are in what may be called, for convenience, the neutral position, but they will exert a counter balancing effect when such drums are turned in either direction from the neutral position. The counter weight for the forward drum'43 is suspended Y by a cable 84 which is anchored to the drum at a point 85 so positioned that. the cable is radial to the drum when the latter is neutral. The cable 86 for the counter weight of the rear tilting drum is similarly connected to drum 44 at a point 87 having the same relation to that drum, that is causing the cable to be radial to the drum when the lat-terV is in neutral position. The two counter weights are shown at 88 and 89, both being brought to the forward side of the apparatus for convenience, although they may be put in any convenient position where they will not interfere with other parts of the apparatus or with the movement of the car in entering upon and leaving the platform. To complete the description of the arrangement here shown, the cable 84 passes around a guide pulley 90, downward and under a sheave 91 connected to the weight 88, and thence upward to an anchorage at 92 on the superstructure. The cable 86 passes under a guide pulley 93, thence over and under guide pulleys 94 and 95 in. succession, over a sheave 96 connected to the weight 89, and upward to an anchorage at 97 on the superstructure.

The preferred mode of connecting each counter weight cable to the tilting drum is shown in detail in Figure 10. The cable is double and both members are made of a single length of rope bent double at the middle point, after being passed through an eye in a lug 98 which projects from the surface of the drum and forms the anchorage 85 or 87 respectively. At the opposite side of the drum from the lug 98 is a spreader 99 made sufiiciently narrow at its ends and at itsV outer edge to enter between the two stretches of the cable leading from the lug 98 when the cable is wound up by the turning of the drum in either direction. The base of the spreader is wide enough to defleet these stretches of the cable in opposite directions far enough to start a helix in the cable at each side of the spreader, whereby cach successive turn of each member of the cable, as the drum continues to rotate, is caused to lie beside the previously laid turn in a uniform helical wind, and is prevented from piling up irregularly on previous turns. This arrangement and mode of connection of thc counter weight cables causes them to apply no torque when the drums are neutral, and to exert equal torque when the drums are turned in either direction from neutral; vthe counter .veight cables to be wound Vevenly with avoidance of the chai'ing and shocks which would be caused by one turn of the cable mounting upon another and then slipping olf g and the weights 88 and 89 are given such value a will best counteract the load placed on the turning motor byV displacement of the center of gravity of the load when tilted. The provision of counter balancing means of any sert in connection with the tilting function of this type of apparatus is a feature novel with the present invention.

T have shown in Figures to 8 a ram or door opener adapted to push away the boards which are customarilyA nailed across the inside of the door opening in a box car, in order to malte possible the closing of the usual sliding door, when the car has been loaded, and to seal more effectively the car' door against leakage of material. This ram or door opener is like that shown in the Ti-iill patent aforesaid (except for the operating means thereof which are a feature of my present invention) and comprises a ram 100 having a slidable face portion 101 and mounted by means of a pivot 102 on a frame 103 built on the lifting platform. The ram is provided with a sector portion 104 the arcuate surface of which is concentric with the pivot 102, and to which an operating cable 106 is secured. This cable passes around guide pulleys 107 and 108 and rises to the superstructure, where it passes around a guide pulley 109 to a drum 110, around which it is wrapped and to which it is made fast. Drum 110 is loose on the same shaft 111 with the lifting drum 30, the latter being fastened to said shaft. Teeth 112 projecting from the outer face of drum 110 (see Figures 9 and 10) form part of a clutch, the complemental member of which is splined on shaft 111 and is formed with two arms 113 adapted to engage the teeth 112. ,This clutch is controlled by mechanism, later described, to connect the drum 110 with shaft 111 when the lifting action takes place, so that the ram will then be compelled to remove the boards from across the car door and force them inward and upward while the car is'being raised. By making the drum 110 of proper diameter, and rotating it at the same time that the platform rises, the opener is caused to place the door boards well toward the roof of the car when the car is fully raised. Y

If the ram operating means were fully positive there would be danger of injuring some part of the apparatus, or the car, in case there should be some obstacle opposing excessive resistance to the movement of the ram. I have avoided danger of any such injury or damage taking place by making the guide pulley 109 displaceable when an excessive load occurs on the cable 106, and by causing its displacement to put the lifting motor out of action. As is shown best in Figure 10, the guide pulley 109Y is mounted in a frame 114 mounted on a pivot pin 115. This frame has two shoulders 116 and 117 adapted to rest upon abutments 118 or 119 respectively according Vas the frame is in the position shown in Figures 5, 9 and 10 by full lines, or the dotted line position shown in Figure 10. A weight 120 is connected to the frame 114i by a strap 121 and a cable 122, the latter passing over a guide pulley 123. This weight normally holds the pulley 109 in thefull line position against the force exerted by the cable 106; but the resultant of the forces so exerted by the two stretches of this cable, passes to the side of the pivot 112 away from the abutment 118, as denoted by the line 1241- in Figure 10. Thus when an excessive resistance is encountered to movement of the door opener, the frame 114@ is displaced by the pull of cable 106 before enough force has been exerted to cause any damage, and in being so displaced, such frame causes or permits opening of a switch in the control circuit of the motor. Such a switch is indicated diagrammatically at 125 in Figure 10. It may be of any suitable construction and character, of which a number are available on the market, such that it will automatically break the circuit, when the frame 1141 is displaced and will be automatically closed when the frame is returned to its normal position.r

The diagrammatic showing of the switch here consists of a casing 125, a conduit 126 enclosing thewires which lead into the casing, and an arm or push member 127 adapted to be engaged by a projection'128 on the frame 11-1. Thus if, during the lifting of the car, an excessive resistance should be encountered to removing the door-boards, the whole action of the apparatus is stopped by stopping of the lifting motor. But if it is desired to continue lifting without operating the door opener, or to lower the car, this may be done by disconnecting the clutch 113-112, whereupon the cable 106 will be relaxed and the switch 125 again closed, and the lifting motor can be put in action again without working the door opener. A counter weight 129 is suspended from the drum 110 for the purpose simply of taking up slack in the cable 106. It is therefore relatively light and has noy appreciable effect in operating the door opener, and does not affect at all the relaxation of the door opening means in the manner just above described.

Referring now to the means for connecting and disconnecting the clutch 112-113, the splined member of this clutch, the one which carries the arms 113, is engaged with a shift lever 130, the form of which illustrated in the drawings is of a well known character, pivoted to the superstructure frame at 131. This shift lever or shifter is controlled by the mechanism shown in detail in Figures 4 and 11 to 15. A control rod 132 is connected to one arm of a bell crank lever 133, pivoted to the frame at 134, the other arm of which bell crank is connected by a link 135 with the clutch shifter. Thus when the control rod 132' is moved upward, manually or by any other agency, the clutch is connected. This control rod carries a dog 136 which is arranged to pass through a notch 137 (Fig. 13) in the bottom of a guide 138 in which a rack 139 is confined with provision for endwise movement only. This rack is in mesh with a pinion 140 secured on shaft 111. Said rack is so placed, and made of such length, that it leaves the notch 137 uncovered when the platform is lowered but is caused by rotation of the drum 30 to cover and block said notch immediately after drum 30vcommences to raise the platform and then it continues to cover the notch while the platform is raised. control rod is lowered and in the clutchdisconnecting position, the dog 136 is beneath the rack and prevents the rod from being raised whenever said notch is so covered, whereby it can be moved to connect the clutch only when the platform is depressed. But when raised, the dog 136 is above rack 139 and does not obstruct the movement of the rack across the notch, or

prevent downward movement-of the control rod when the notch is thus obstructed. It will be observed from Figures 14 and 15 that the dog is properly constructed, and controlled by a spring 141 and abutments 142, to yield when being moved downwardly past the rack, and to oppose a positive obstruction to upward movement of the control rod when beneath the rack. It is to be understood that the rod is properly guided and restrained so that it can be moved only in directions approximately coincident with its length. Thus, while the clutch for actuating the door opener' can be connected only when the platform is in lowered position, it can be disconnected at any time.

The particular mechanism which 1 have just described for controlling the connection of drum 110 with its shaft is only one of a number of various mechanisms which l may use for the same purpose. Hence it is to be understood as an illustrative embodiment of means for this purpose, and not as a limitation to one specific means. Similar statements may be understood as to other mechanisms herein shown and described, except in so far as the intent of the claims and the bearing of the prior' art may require limitation to particular embodiments shown.

I have not shown herein any means for centering and securing the car on the platform, or for stopping, starting and reversing themotors and controlling their brakes, as such means are-not claimed as part of the present invention, and may be cf various kinds known to the art. I reserve the right however to claim in subsequent applications such inventions as I have made in respect to such controlling means.

Thus if the isY What I claim and desire to secure by Letn ters Patent is: Y

1. In a car dumping apparatus an elevating platform a superstructure, two lifting drums and a tilting drum on said superstructure abovethe front and the rear sides of the platform, a cable passing from the lift-ing drum downward and around a sheave on the platform, thence upward and around a pulley on the superstructure, thence downward and around another sheave on the platform, and Vfinally upward and to the adjacent tilting drum; there being one such cable so arranged between each lifting drum and the tilting drumat the same side of the apparatus. l Y Y 2. In a car dumping apparatus an elevating platform a superstructure, two lifting drums and a tilting drum onrsaid superstructure above the front and the rear sides of the platform, a cable passing from the lifting drum downwardand around a sheave on the platform, thence upward and around a pulley on the superstructure, thence downward and around another sheave on the platform, and finally upward and to the adjacent tilting drum; there being one such cable so arranged between each lifting drum and the tilting drum at the same side ef the apparatus, an independent driver for rotating all said lifting drums in unison while Vthe tilting drums are still, and an indepen dent driver for rotating the tilting drums in unison while the lifting` drums stand still.

3. In a car elevating apparatus in combination with an elevating platform, lifting drums, tilting drums, and cables engaged with the drums of both classes andwith the platform, a counter weight suspendedfrom said tilting drum by means of a cable which is radial to said drum when the latter is in neutral position and wrapped about the drum by rotation of the latter in either direction from neutral position. f

4. In a car dumping apparatus a platform, cables for raising and tilting said platform, drums for respectively lifting and tilting the platform to which said cables are connected, the tilting drum having a neutral position when the platform is horizontal and being rotatable in opposite directions to tilt the platform back and forth, a counter weight for the tilting drum and a suspension cable for said counter weight connected to said drum at a point which causes the cable to be radial to the drum when the latter is inV neutral position, and to be wound up on the drum when the latter' is turned in either direction. Y

5. In a car dumping apparatus a'platform, cables for raising and tilting said-platform, drums for respectively lifting and tilting the platform to which said cables are connected, the tilting drum having a neutral Vposition when the platform is horizontal and rota able in opposite directions to tilt the platform back and forth, a counter weight for the tilting drum and a-suspensioncablefor said counterweight connected to'said drum at a point which causes the cable to be radial to the drum when the latter is in Vneutral p0- sition, and to be wound up on the drum when the latter is turned in either direction, the said counter ifi/'eight cable being doubled and connected at its bend to the drum, and the drum having a spreader at its opposite side from said cable connection arranged and adapted` to separate the cable members and lead them in a helical path when the drum is rotated.

6. A car elevating apparatus comprising a platform, lifting and tilting means for said platform including suspension cables and drums for taking up and paying out said cables, counter weights arranged to'act on the lifting drums with counter balancing effect to the weight of the platform, and another counter weight for counter balancing the unbalanced load when the platform and the car thereon are tilted.

7. A car elevating apparatus comprising a. platform, lifting and tilting means for said platform includino' suspension` cables and drums for taking up and paying out said cables, counter weights arranged to act on the lifting drums. with counter Vbalancing effect to the weight of the platform,y and an* other counter weightv for counter balancing the unbalanced load when the platform and the car thereon are tilted, the said last named counter weight being so connected with the tilting drum asy to exert no torque thereon when the load is untilted.

8. In a car dumping apparatus a platform, means for lifting said platform, a car door opener, means for operating said opener when'the platform is raised, and means operated by. the last named means when an excessive resistance is encountered by the opener for stopping the driving means.

9. In a car dumping apparatus an elevating platform, lifting means for said platform, a car door opener, means for operating said opener, comprising a drum driven Vby said lifting means and a cable which is taken up by said drum, a guide pulley over which said cable passes, a displaceable holder for said guide pulley arranged to permit displacement thereof when excessive stress is developed in the cable, and means by which such displacement causes interruption of the action of said lifting means.

l0. In a car dumping apparatus a plat form, means for lifting said platform including an electric motor, a car door opener,

a takeup drum rotatable by said lifting means, a cable adapted to be taken up onV said drum and connected to saidopener so memes prising a cable connected to the opener,

takeup drum on which said cable is wound,

. a drive shaft with respect to which said drum is loosely mounted, and a clutch for connecting said drum separately to said sha-ft, means for stopping said motor when the door opener encounters excessive resistance comprising a displaceable guide over which said cable runs and a switch in the control circuit of the motor arranged to be opened when said guide ris displaced, means for disconnecting said clutch, whereby the tension of the door opener cable may be relaxed, and automatic means for closingn said switch when the cable tension is so relaxed.

12. A car dumping apparatus comprising a platform, a superstructure,hoisting drums mounted on said superstructure, each approximately over one of the four corners of said platform, a motor coupled to said drums for operating them in unison, a tilting drum located between the hoisting drums over the forward side of the platform, a second tilting drum located between the hoisting drums over the rear side of the platform, a second motor coupled to both tilting drums for operating them in unison, a cable attached to each hoisting` drum passing downwardly and upwardly with a bight in running connection with the part of the platform directly beneath and thence extending to connection with the nearest tilting drum; rotation of said hoisting drums in unison causing the platform to be raised or lowered, and rotation of the tilting drums, while the hoisting drums are stationary, causing the platform to be tilted endwise.

13. A car dumping apparatus comprising a platform, a superstructure, hoisting drums mounted on said superstructure, each approximately over one of the four corners of said platform, a motor coupled to said drums f for operating them in unison, a tilting drum located between the hoisting drums over the forward side of the platform, a second tilting drum located between the hoisting drums over the rear side of the platform, a second motor coupled to both tilting drums for operating them in unison, a cable attached to each hoisting drum passing downwardly and upwardly with a biglit in running connection with the part of the platform directly beneath and thence extending to connection with the nearest tilting drum, a counter weight suspended from each of the hoisting drums, and counter weights sucpended from thek tilting drums, the pension means for the tilting drum` counter weights having radial connection with the tilting drums when the latter are in neutral position.

14. In yan apparatus of the character described, the combination with a load hoisting mechanism, of a cable take up drum, a driving-shaft rotatable synchronously with said mechanism and with respect to which said drum is loosely mounted, a clutch for coupling` said drum to said shaft, a clutch controller, and means driven by .the rotation of said shaft and coacting with said controlby the rotation of said shaft and coacting v f with :said controller to prevent coupling of said clutch except when the hoisting mechanism is in the load-lowered position.

16. ln, a mechanism of the character described, av cable taire up drum, a drive shaft for said drum with respect to which the latter is loosely mounted, a clutch for coupling said drum to said shaft, an endwise mevable cl-utch controlling rod, a dog carried by said rod and arrano'ed to prevent movement of the rod upon encountering an obstruction when moving in one direction but 'being yieldably displaceable by an obstruction in its path when moving in theopposite direction, and an obstructor driven by said shaft to move into and out of the path of said dog when the shaft is driven in one direction or the other.

n17. In an apparatus of the character le'- scribed, a cable drum having a perforated lugl projecting from its circumference, a cable passing through said lug and bent at the lug to form two stretches running side by side adapted to be wound on the drum, and a spreader projecting from the surface of the drum opposite to the lug constructed and arranged to enter between the stretches of the cable and lead them in helices of opposite pitch when the drum is rotated.

' 18. In an apparatus of the character described, a cable drum, a cable connected to said drum and consisting of two stretches running side by side, and a spreader on the drum arranged to enter between the stretches of said cable and lead them in helices of opposite pitch when the drum is rotated.'

19. In an apparatus of the character de-A scribed, a cable driving drum rotatable in opposite directions, and a counterweighting means coupled tosaid drum, comprising a cable connected to the circumference of the drum and arranged to lead radially therefrom when the drum is in neutral position, and a weight suspended by said cable.

20. In an apparatus of the character described, a cable driving drum rotatable in opposite directions, and a counterweighting means coupled to said drum, comprising a cable connected to the circumference of the drum and arranged to lead radially therefrom when the drum is in neutral position, and a 'weight suspended by said cable, combined with means for inclining the cable helically of the drum in the course of the first revolution of the drum in either direction from said neutral position. c

2l. In an apparatus of the character described, a cable drum, a cable connected to said drum and consisting of two stretches running side by side, and a spreader on the drum spaced circumferentially about the latter from the point of connection of the cable and being wider at its base than the distance between the` stretches of the cable, while its outer extremity and sides are formed to enter between said stretches and lead them in helices of respectively opposite pitch when the drum is rot-ated.

22. In power transmission apparatus, means for moving the load including a cable, a take up drum for the cable and an electric motor for driving said drum, a guide pulley about which the cable is bent in passing from the drum to the load, a pivoted frame carrying said guide pulley, a motor controlling switch adapted to be opened and closed by movement of said frame from one position to another', a yieldable rotating means and an abutment for said frame cooperating to hold the latter in switch closing position; the pivot of said frame being so located with respect to the pulley that the resultant of the tension in the cable passes near to the axis thereof and at the side of the aXis Vaway from said abutment;

In testimony whereof I have affixed my signature.

MARTIN B. MoLAUTI-ILIN.

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