US1704496A - Hoisting apparatus - Google Patents

Description

March 5, 1929.

Filed Dec. 27, 1923 R. E. BROWN HOISTING APPARATUS 9 Sheets-Sheet 1 March 5, 1929. R. E. BROWN HOISTING APPARATUS Filed Dec. 27, 1925 9 sheets-sheet 2 L "l n March 5, 1929. R. E. BROWN HOISTING APPARATUS Filed Dec. 27, 1923 9 Sheets-Sheet 3 INVENTOR 2% March 5, 1929. 5 BROWN 1,704,496

HOISTING APPARATUS I Fild Da e. 27, 1925 9 Sheets-Sheet 4 INVENTOR March 5,1929 4 REBROWN 1,704,496

/ HOI STING APPARATUS Filed Dec. 27, 1923 9 Sheets-Sheet 5' faz ga Malfch 1929- I R. E. BROWN HOISTING APPARATUS Filed Dec. 2'7, 1923 9 Sheets-Sheet 6 INVE NTOR March 5, 1929. BROWN 1,704,496

I HOISTING APPARATUS Filed Dec. 27, 1923 9 Sheets-Sheet 7 Marh 5, 1929. R. E. BROWN HOISTING APPARATUS Filed Dec. 27, 1923 9 Sheets-Sheet 8 fig/.9-

INVENTO'R March 1929- 4 R. E. BROWN 1,704,496

HOISTING APPARATUS v Filed Dec. 27, 1925 9 Sheets-Sheet 9 TROLLEY R/ms R/lC/f CONT/701 L El? H0157 CQIVTROLL ER m In N1 HOLD BRAKE HOIS'T O Bra/m E MAGMEI RICK 851W! 5 HOLD... 6 L l/TCH $1- nnuM-cwrcu INVENTOR Patented l g,

UN lTE' RAYMOND E. BEGW'N, OF PITTSBURGH, PEHNSYLVANIA, ASSIGNOB. T0 HEYL &'PAT,- TEE/SON, INCORPORATED, 0F EITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

HGISTING APPARATUS.

Application filed December 27, 1923. Serial no. 682,943. i

The present invention relates to hoisting and conveying apparatus of the type employing a grab bucketcarried by a trolley or other traversed support, such as is commonly used for handling bulk materials in large quantitrolley with ropes passing from the bucket and from. the trolley to the hoisting engine and the. trolley traversing engine, respectively. v y

The object of the present invention is to provide an improved control system for the grab bucket and trolley which is equally ap' plicable to eitherof the above types of apparatus. V V

In the accompanying drawings I have shown, for purposes of illustration only, my invention embodied in a holstmg apparatus of the man trolley type, but it will be apparent from the following description that the invention is not limited in its application to this particular type ofapparatus.

In the drawings:

Figure 1 is a plan view of the trolley; Figure 2 is a side elevation of the trolley and grab bucket suspended therefrom;

Figure 3 is an end View of the main hoisting gear, showing onevof the clutches associated therewith and the means for operating the same;

Figure 4 is a sectional View on the linev IVIV of Figure 3;

Figure 5 is a view, partly in elevation-and partly in section, of the double acting clutch operating cylinder and parts associated therewith; I

Figure 6 is a sectional View taken approximately on the line VIVI of Figure 5 Figure 7 is a vertical sectional view taken on the line VIP-VII of Figure 5; I

. Figure 8 is a horizontal sectional view taken on the line VIIIVIII of Figure 3, illustrating a portion oi the clutch operating means;

Figure 9 is a sectional view illustrating a magnet actuated valve for controlling the fluid supply to one end of the double acting cylinder; I

Figure 10 is a View illustrating the brake means for one of the hold drums and the fluid. pressure actuated means for releasing said brake means; I i

Figure 11 is a side elevation of the hoist motor brake and .its operating means; I

Figure 12 is a detail View of the spring means for setting the hoist motor brake;

.Figure 13 is a side elevation of oneoi' the rack motor brakes and itsoperating means;

Figure 14 is a View illustrating a magnet controlled alve for regulating the pressure fluid supply to the fiuidpressure cylinder associated with the rack brake shown in Figure 13; i i i Figure 15 is aQview illustrating a magnet controlled exhaust valve for the fluid pres sure cylinder shown in Figure 14, and

Figure 16is a diagram showing the piping and electrical connections of the control system. Y r V Referr ng to Figures land '2, the trolley frame 3 carries-the usual track'engaging wheels 6 mounted upon axles 7 driven by trolley traversing or rack m'otor s 8. The trolley frame supports a grab bucket- 4 and has suspended from one .end thereof the usual operators cab 5. p

While the application of. my improved con trol system, to be hereinafter described, is not restricted to hoisting apparatus having any particular, arrangement of drums for the bucket ropes, or any particular type of clutch 1 means foroperatively connecting the drums to the hoist motor, I prefer to .employ the drum arrangement and clutch means disclosed in the copending application of Hans En ard, Serial No. 664,706; filed September Mounted upon a shaft 9 journaled in the frame 3 are the two hold drums 10 and 11' and the closing drum 12, the hold drums being keyed to the shaft and the closing drum being mounted loosely thereon. Also mounted to rotate freely upon the shaft 9 is a main hoist gear 13, said gear being arranged intermediate the adjacent ends of the hold drum 10 and closing drum 12.

A ring gear 15L (Figure 1) ported at one side of the main gear 13upon rollers 15 mounted upon pins 16 carried by said main gear. a V I The main gear and ring gear are driven, at the same speed by a hoist motor 17. This motor has a pinion 18 mounted upon its armais rotatablysup- I.

ture shaftwhich meshes with a gear 19 on the end of an intermediate shaft 20 journaled in suitable hearings in the trolley carriage. The intermediate shaft carries a pinion 21 meshing with the main gear 13 and also carries a pinion 22 of the same pitch diameter as the pinion 21. By reference to Figure 7, it will be seen that the pinion 22 meshes with a pinion 23 mounted upon a short shaft 24, the pinion 23 meshingwith a pinion 25 journaled upon a shaft 26 beneath and parallel to the shaft 20. Another pinion 27' of the same diameter as the pinion 25 is also rotatably mounted upon the shaft 26 and is integrally connected with the pinion25 by means of a sleeve 28. The pinion 27'meshes with the ring gear 14. 7

Referring to Figures 5 and 6, the pinion 23 is adapted to be'moved a short distance inopposite directions from its central position, in which its axis is in the same ver tical plane as the axes of the pinions 22 and 25. For this purpose the pinion 23 is operatively connected to a double acting fluid pressure cylinder 29, the piston 30 whereof has its piston rod 31 pivotally connected to one end of of a pair of bars 32 arranged at opposite'sides of the pinion and having the short shaft 24 extending therethrough.

T hese'bars extend through a guide 33.- Each end of the shaft 24 ext-ends through an eye- 34' formed on the end of a stein'36. Each stem 36 extends through two spaced plates l 37 and 38, which are slidably mounted upon apair of parallel rods 39 projecting from an end wall of the cylinder 29.- Each stem 36 is surrounded by'acoil spring 40 which abuts at its ends against the plates 37 and 38 and'normally maintains these plates in engagement with nuts 41 and 42 on the rods These springs normally maintain the 39. pinion 23 in its central position, in which position of the pinion both ends of the cylinder 29 are open to the exhaust.

The sprin 's 40 will be put under compression upon movement of the piston 30 in either direction. 7 When the piston moves to'the left the eyes 34 on the stems 36 engage the plates 37 and move them to the left, thereby compressing springs 40, and when the piston casings 45 and 46.- These valve casings are connected by other pipes 47 and 48 to a pipe 49 connected to a suitable source of pressure fluid supply, preferably a compressed air reservoir (Figure 16). The valves in these valve casings may be operated by -electro-' magnets 50 and 51.

The magnet 50 is shown in detail in Figure 9, it being understood that the magnet 51 is of identical construction. It comprises a coil 52 surrounding a stationary hollow core 53. A plunger 54 is mounted in said core and carries an armature 55 upon its upper end. The lower end of the plunger constitutes a valve 56 adapted to engage a valve seat in the upper end of a sleeve 57. The valve 56 is connected by a valve stem 58 with another valve 59 adapted to engage a valve seat in the lower end of the sleeve 57. The valve casing 45 has a chamber 60 therein beneath the sleeve 57 and communieating with this chamber is the supply pipe 47 leading from the source of fluid supply; The pipe 43 leading to one end of the cylinder 29 is tapped into the valve casing and communicates with the interior of the sleeve 57. The valve casing has another chamber 61 therein above'the sleeve57 and this chamber communicates with an exhaust port 62. A spring 63 in the chamber'fiO engagesthe Valve 59 to normally maintain it against its seat and the valve 56' away from'its seat. Under these conditions the end of the cylinder which is connected by the pipe 43 With the valve casing is open to the exhaust. lVhen, however, the coil 52 is energized, the armature 55 is attracted towards'the' core 53, thereby moving the valve 56 into engagement with its seat and the valve-59 away from its seat. This cuts off the end of the cylinder from the exhaust and places it in conm'iunication with the source of fluid supply through the pipe 43, sleeve 57, chamber 60 and pipe 47. Y

Fig-

The operation. of the parts shown in tires 5 and 6 is as follows: Normally, as already stated, both ends of the cylinder 29 are open to the exhaust and the springs 40 maintain the pinion 23 in its central position.

Let it beassumed that the magnet 50 is energized. This places the right-hand end of the cylinder 29 as viewed iii Figures 5 and 6 in communication with the source of fluid supply, the left-hand end of the cylinder remaining open to the exhaust.- The piston 30 is therefore moved to the left, thereby moving the shaft 24 in the same direction. The pinions Y25 and 27 will, therefore, be rotated in a counter-clockwise direct-ion through an angle corresponding to twice the amount of, motion of the shaft 24, since the tooth contact between the pinions 22 and 23 serves as the fulcrum of a lover of the third class.

The ring gear 14 will, therefore, be rotated in clockwise direction, as viewed in Figure 3, relative to the main gear 13. parent that the distance moved by the teethof the ring gear will be equal to twice the distance moved by the shaft 24. It will also be apparent that this relative movement between the-ring gear 14 and main gear 13 will take place irrespective of whether the pinion 22 is being driven by the hoist motor 17 or is stationary. If, instead of the magnet 50 It will be apbeing energized, the magnet 51 is energized, then the piston 30 will be moved to the right and consequently the pinions 25 and 27 will be rotated in a clockwise direction and the ring gear 14 will be rotated in a counterclockwise direction relative to the main gear 13.

Referring to Figure 4, the drums 10 and 12 have flanges 63 and 64 on their adjacent ends positioned within the rim of the main gear. The peripheral surfaces of these flanges constitute clutch engaging surfaces. The main gear has associated therewith a clutch for cooperation with the clutch surface of the flange 63 of-the hold drum 10 and another clutch of identical construction for cooperation with the clutch engaging surface of the flange 64 of the closing drum 12. Therefore, it will only be necessary for the purpose of understanding the present invention to describe one of these clutches.

The clutch for cooperation with the flange 63 of the hold drum 10 is shown in Figure 3. This clutch comprises a clutch band 65 which is anchored at one end upon a pin 66 carried by the main gear. The other end of this band is pivotally connected to a lever 67 pivotally mountedupon said pin. A connecting rod 68 is pivotally connected at one end to the lever 67 and at its other end is pivotally connected' to a lever 69 pivoted upon a pin 70 carried by the main gear. A stem 71 is pivotally connected at one end to said lever 69 and extends through an opening in a spoke of the main gear. Said stem has a nut mounted upon its other end and surrounding the same between said nut and said spoke is a coil spring 72. The spring 72 normally maintains the clutch band in holding engagement with the surface of the flange 63. It will be understood that in like manner a clutch of identical construction is associated with flange 64 and is normally held in holding engagement with said flange.

Relative movement of the ring gear 14 with respect to the main gear 13, as effected by themeans disclosed in Figures 5 and 6, serves to release one or the other of the clutches as desired. For this purpose the ring gear is operatively connected to the connecting rods 68 and 68 of the respective clutches. This operative connection comprises a T-shaped lever 73 (Figure 8) pivoted upon a pin 74 secured in the main gear 13 and projecting within the interior of the rim thereof. The lever 73 is hollow to receive a pin 7 5' which is pivoted atone end to the ring gear 14 upon a pin 76 carried by said ring gear. It will be seen that relative movement of the ring gear 14 in one direction or the other with respect to the main gear 13 will rock the lever 73 about its pivot 74. The lever 73 is connected by links 77 with a lever 78 pivoted upon a pin 79 carried by the main gear. The opposite ends of the lever 78 extend into horizontal carry pins 80 and 81 which extend'through vertical longitudinal arcuate' slots 82 and 83'intersecting said horizontal slots. These pins are normally both positioned adjacent corresponding ends of said slots 82 and 83-. As shown,the pins arepositioned adjacent the left-hand ends of the slots.

The operation of the clutch releasing means is as follows: Normally the clutches main-' .tain the drums 10 and 12 operatively connected to the main gear. If it is'desired to release the closing drum 12 from the main gear in order to open the bucket, forexample, the magnet 51 will be energized, thereby caus ing the piston 30 to be moved to the right-and the pinion 27 to be rotated in a'clockwise' direction. Consequently the ring gear will be rotated in an anti-clockwise direction relative to the main gear, thereby rocking the lever 7 8v about its pivot 79. This will cause the pin 80 to engage-the end wall of the slot 82 and move the connecting rod 68 to-the left to release the clutch engaging the flange 64. Rocking of the lever 7 8 for this purpose will have no effect whatever upon connecting rod 68 'ofthe clutch engaging flange 63 of hold drum 10, for the reason that the pin 81 will.

simply travel in the slot 83 but willnot travel far enough to engage theopposite end wall of the slot'83 and move connecting rod 68 to the right.- On the other hand, if it is de sired to release the clutch engaging the flange 63 of hold drum 10 in ordert'o close'th'e,

bucket, for example, the magnet 50 will be energized, thereby effecting movement o'fth'e piston 30 to the left. This will result in the pinion 27 being rotated in acounter-clockwise direction and the ring gear 14 in a clockwise direction with respect to; the main gear. The lever 78 will therefore be rocked about its pivot 79 ina direction to cause the pin 81 j to' engage the end wall of the slot83and move the connecting'rod 68 of the clutch associated with the flange 63 to the left, thereby releasing the hold drum 10 from the main gear.

The other hold drum 11, as is customary,

has a brake associatedtherewith. In Figure 10 I have shown a brake of the character or dinarily employed, which comprises a brake band 84 engaging a rim 85 on the drum 11.

One end of the band is anchored upon a pin 86 and the other end is connectedto one end of a bell crank lever 87 by means of a con In order to releasethe brake band, pressure fluid may be admitted into the cylinder above the piston through a pipe 94: which'is connected to a valve casing 95. This valve casing is connected by a pipe 96' to the source of pressure fluid supply and has an exhaust pipe 97. The valve construction within the, casing. 95 may be identical with that within the casings and 46 and may be operated by a magnet 98 of identical construction with the magnets and 51.

A brake 99 may be associated with the armature shaft of the hoistmotor 17, in order to prevent a suddenly applied reverse load onthe gears and bearings thatresults from a sudden application of the brake associated with .the hold drum 11. This brake may be of the usual shoe or post type which is equally 'efiectivein both directions of rotation of the armature shaft and prevents over-travel when 9 the power is shut off the hoist motor and the L-shaped lever is connected to the upper end of lever 102 by a connecting rod 104. The long arm ofthe L-shaped lever is pivoted at its end to the'upper end otja stem 105 which extends through upper and lower spring seats 106 and 107. -These spring seats are guided on vertical guide rods 108, and a coil spring 109 is interposed between the spring seats and surrounds the stem 105; Upward movement of the upper spring seat-106 is limitedby nuts 110. 11 the screw-threaded upper ends of the guide rods 108. It will be apparent that the spring v109 tends to maintain the brake applied. In order to release the brake, a fluid-pressure cylinder 111 is provided, having a piston 112 working therein. The piston rod .113 of this piston is pivotally connected at its upper end to the long arm of the lever 103, and the piston is positioned in the lower end of the cylinder when the brake is applied. Pressure fluid may be introduced into the lower end or" the cylinder-through a pipe 11 to raise the piston and release the brake. This ipe may connect with the pipe94l (Figure 16), so that the pressure fluid supply to the hold brake and hoist motor brake may be controlled by the same magnet 98. e

A brake 115, similar to the brake 99, may

be associated withthe armature shaft 7 of each of the 'rack'motors 8. One of these b'rakesus shown n Figure 13, parts corresponding to the parts of the brake 99 shown in Figure 11 having the same reference characters applied thereto, but with a prime atfixed. This brake is released by a spring 116 arranged in the cylinder 111 beneath the piston 112, and is adapted to be applied by pressure fluid admitted to the upperend of the cylinder through'a pipe 117. The 'pipe 117 is connected to a normally closed exhaust valve 118 adapted to be opened by an electroelectro-magnetic operating means is shown in detail in Figure 14, it being understood that the high pressure inlet valve and its operat 'ng means are oi? identical construction. It will be apparent that when the coil of the electro-niiagnet 122 is energized, the armature 126 thereoi will be drawn upwardly, and the valve 120 moved into engagement with its seat by reason of the arrangement of the con-, necting means between the valve and arma ture.

The exhaust valve 118 and its electro-magnetic operating means are shown in detail in Figure 15. By reason of the arrangement The low pressure inlet valve 120 and-it's ture 127 of the electro-magnet 119 and the valve 118, the latter will be moved away from its seat when the coil of the magnet is ener gized and the armature ,jdrawn upwardly thereby, as will be apparent. r

It will be understood that, while in the diagram of Figure 16 I have illustrated only one of the rack'motors and its brake and brakecontrolling means the other rack motor may be provided with identically the same brake means. i

Having described the construction and operation of the clutches for the hold and closing drums and oi the brakes for the hold drum and hoist and rack motors, I will now proceed to describe my improved control system for these parts, reference being had to the diagram of Figure 16 whichillustrates the system. l h h My control system, as applied to the above described construction,comprises the following units: A controller for the hoist motor; a controller for tne trolley-traversing or rack motor or motors; the above described fluidpressure cylinders for the brakes and clutches and the magnet controlled valves for the same; contact fingers and segments in the two controllers forming parts of the circuits for the several magnets; a finger-operated switch in the rack controller handle for completing the circuit to the magnet for, one of the clutches; a foot-operated switch for completing the circuit to the magnet'tor the other clutch, and a foot-operated valve to prevent the release of the hold brake when the motor brake is released when this is desired, as for closing the bucket in the air or on the'side of a pile where it has a tendency to fall over.

In describing my control system, I will first take up the control of the bucket, and later describe the control of the rack motors.

Referring to Figure 16, conductors L and L leading to the hoist control panel and rack control panel of the hoist. and rack motors are adapted to be electrically connected with the trolley rails through a main switch S. It will be understood that the hoist controller handle has the usual number of positions for controlling the speed of the hoist motor both in raising and lowering the bucket.

The circuit for energizing the brake magnet 98 comprises a conductor 128 tapped from the conductor L. A conductor129 is tapped from'the conductor 128 and leads to the magnet, and another conductor 130 leads from the magnet to a finger 131 in the hoist controller. From another finger 132 in the hoist controller a conductor 133 leads to the conductor L. The fingers 131 and 132 are bridged by the segments 134 and when the hoist controller-handle is moved to any position for raising the bucket, and by the segments 136 and 137 when handle is moved to any position for lowering the bucket, thus completing the circuit to the brake magnet 98 in either case. Therefore, except for the auxiliary control of the hole brake by the operators foot, as previously described, the hold brake and thehoist motor brake are controlled entirely by the position of the hoist controller handle.

words, putting the controller handle in any position for hoisting or lowering will release the hold and hoist motor brakes, and'putting the handle in the neutral or off position will. release the pressure fluid from the brake cylinders and permit the springs to setthe brake. The operator needs only to move the handle asdcsired to start the motor in either the rip-or down direction or to stop it, and the brakes will be released and appliedwithout any attention on his part beyond the normal movement of the controller handle.

Satisfactory control of either clutch cannot be obtained by theposition of the hoist motor controller handle alone, without either rest *icting the powerfor closing the bucket or limiting the range of-speeds at which the bucket can be hoisted to less than the range normally givenby the controller. Separate control units beir a iecessary'for the clutches, therefore. I have found that a linger-operated switch on the rack controller handle which controls the trolley-traversing motor or motors best answers this requirement as regards the hold clutch.

The circuit for energizing the hold clutch magnet comprises the conductor 128 leading to the magnet-coil, a conouctor 138 leading from the magnet coil to finger 139 in V) :4. t 119.

In other controller, a cond netor l 148 lead nected through a normally open push-button switch 148 on the rack controllerhandle.

It might appear preferable to havethe push-button switch 148 on the hoist controller handle on account of the clutch which it controls being associated with the hoist motor. Actual experience, however, has demonstrated that this is not the case, for several reasons. One is that it is quite customary to have an OK position latch on controller handles, and hence it is necessary in placing an auxiliary contact on a controller handle to so select its functions that no harm will result if an operator, from force of habit, presses this contact when starting to move the controller handle. If the hold clutch were unintentionally released when starting to hoist the open buckethigher, after. having had it hanging in the air, the freeing of the hold drum from its connection with the motor would permit the bucket to fall, resulting in the breaking of the closing lines when they became tight, as the closing drum, being connected to the motor by its clutch,

could not start to turn in the downward'direction. Another reason for locating the hold clutch switch on the rack controller handle is that in normal operation the rack cont-roller handle is stationary during the closing of the bucket, at. which time the hold clutch must be held released, andconsequen'tly the hand that is controlling the hold clutch hasno other duties to perform at that time. 1

As previously stated, this auxiliary fingeroperated switch on the rack controller handle closes the circuit to the hold clutch magnet,

but in addition to this, the circuit passes through the contact. fingers and segments 1n "the hoist controller, so that the hold clutch can only be released when the hoist controller handle is in the proper position, that is, when power is being applied to the motor to turn it in the hoisting direction. ception to this, to take care of the condition when it is desirable to open the bucket very There is one eX-- slowly, or when for any reason the bucket fails to onen itself: when the closin drum is 4 p freed by the release of the closing drum clutch. For th spurpose, the controller is provided with one point giving reverse power to the motor, and in this position, the hold clutch can be released, provided the hold brake is app ed as Will be d scribed later,

" The same "nditions thatled th nhoice place for the finger-operated switch for'releasing the hold clutch have resulted in choosing a foot-operated switch as the best means for releasing the closing clutch to permit the free opening of the bucket. .his switch is in series with fingers and se ments in the hoist controller which are in contact only when the controller handle is in the off position, as it is not necessary for the bucket to be dumped while it is being hoisted or lowered. The foot-operated switch being thus inopeartive except when the hoist controller handle is in the off position, there is little danger of the bucket being dumped by the accidental pressing of this foot switch, since itis not customary to leave the bucket with a load in it when it is not in regular operation.

The circuit for energizing the closing clutch magnet 51, and including the above mentioned foot-operated switch, comprises a conductor 149 tapped from the conductor 128 and leading to the magnet coil, conductor 150 leading fromthe magnet coil to the foot-operated switch 151, a conductor 152 leading fromthe switch to a finger 153 in 'the hoist controller, and the conductor 133 leadingfrom thefinger 132-to conductor L. The fingers 132and 153 are bridged by the segment 136 and a contact 154 when the hoist controller handle 1sv in the neutral or off position. It. will; be apparent, therefore, that depression of the foot-operated switch 151 will close the circuit to'the closing clutch magnet-51 only when the controller handle is in the off position. v

On man trolleys it. is convenient to lead the pressure fluidpipes into the operators cab, and to have the magnetcontrolled valves forthe clutches and'brakes also located in vthe'cab. This is also'the case with some rope system bridges where the voperations cab is located near the main engine house. Under such conditions, the preferable method of obtaining the independent control of the hold brake,'which. preventsits release when the hoist controller is in a hoisting or lowering position, is to provide athree-way valve in the pipe line going from the brake valve to the hold brake cylinder, leaving the motor brake cylinder connected direct to the brake valve.

In'the illustrative embodiment of the in vention, I have shown the pipe 94 brought up close beneath the floor of the operators cab and provided at this point with the three-way valve 155 operable by a spring-returned footpedal 156, whereby the valve may be moved, when desired, to the positionwhich shuts oil the flow of pressure fluid to the hold brake cylinder 91 and opens a port permitting the free exhaust of the pressure flu-id in the cylinder,

thus permitting the hold brake to be maintained applied by lts springwhen the hoist 156 is pressed to close the push-button sw 157 and operate the three-way valve 1 controller is in a position which normally re leases the hold brake. As stated before, this is to permit the bucket to be closed in the air or on a side slope where it tends to fall over. This auxiliary control is also used when the bucket is to beopened by using reverse power on the motor, which is occasionally desirable, as already explained.

The foot-pedal 156 for operating the threeway valve 155 has in connection with it a push-button switch 157 which is in the'circuit with the push-button switch 148 on the rack.

ductor 188 and leading to the switch, a conductor 159 leading from the switch to a iin ger 160 in the hoist controller and a conductor 161 leading from a finger 162 in the hoist controller and joining the conductor 140. The fingers 160 and 162 are bridged by a contact 168 when. the hoist controller is in. the

position for giving reverse power to the motorr The controller position giving this r verse power to the motor is on the lowering side of-the cont-roller, beyond the last lowering point, which gives the maximum lowering speed. To prevent the unintentional application of power to the hoist motor when lowering a load, an additional safety device is pro-- vided, inthe form of a push-button switch 164 in the holst controller handle, which must be pressed in order to close the circuit to the magnet for operating the reverse power switch, and which is operative only when the hoist controller handle is in this extreme oosition. The circuit for the uish-luitton switch 164, when the hoist controller handle is in the position for givingreverse power to themotor, and when the operatorhas pi thisswitch and also 'tliepuslnbutton switch 148 on the rack controller handle, may be tracedas follows: from the conductor '11, by

way of conductor 165 to the magnet 166 in th hoist control panel for. operating the revel; power switch, from said magnet to finger 16. and contact 168 by way of the conduchf r169,

' and from contact 168 to contact 163 and finger 162, the said contacts being electrically connected through said push-butttm switch From the linger 162 the circuit continues through the conductors 161 and 140 to the rack controller, and through the latter, by

way of push-button switch 148, and conducv tor 143 back to conductor L; Of course, putting reverse power on the motor will not ef fect opening of the bucket, unlessfoot-peda itch which effects release of the hold clutch controlled by one set of fingers and segments in the hoist controller. The foot-pedal 156 in this case, instead of being used to operate a three-way valve, would be arranged to open the circuit leading from the hoist controller to the valve magnet for the hold brake, so that when the pedal was pressed, the controller could release the motor brake, leaving the hold brake set. Thus the same control is obtainable as with the three-way valve arrangement previously described, it being possible to set the hold brake with the controller in a position which normally releases it, but not to release it when the controller has it set.

The above description of the control sys tem may be made more clear by taking up in order the motions which the operator makes-for a complete cycle of duty for the bucket in the normal operation thereof-z Starting with the bucke'tresting on the coal,

it is closed by moving the controller handle to a hoisting position, and at the same time pressing the button on therack controller handle-which releases the hold clutch and permits the motor to wind up the closing ropes alone; and when the bucket is closed, it is merely necessaryto release the pressure on the button, permitting the hold clutch to set and turn the hold drum so that both sets of lines are taken in at the same rate and the bucket is hoisted. l/Vhen the bucketis at the desired height, power is shut off from the hoist by'putting the controller handle in the off position, which also sets the motor brake and thehold brake. When the buckethas been carried. by the trolley to the dumping point, it is opened bypressing the foot-switch which releases the closing'drum clutch, per

mitting the weight of the material in the bucket, through the pull on the closing lines, to turn the closing drum in the reverse direction. At the proper instant the foot-switch is released, which sets the closing. clutch again, stopping the spinning of the drum and leaving the bucket ready for lowering,

, open, which is done by moving the controller handle to any desired lowering point. -This releases both brakes, and the speed is controlled, as usual in this class of machinery, by dynamic braking or regenerative braking.

\Vhen it is desired to close the bucket in the air or on a side slope where it tends to fall over, the operator, in addition to pressing the button-148 on. therack controller handle as he moves the hoist controller handle to a hoisting position, will press the foot-pedal- 156, whereby the motor brake alone will be released, leaving the hold brake set. If the operator desires to use reverse poweron the hoist motor, he will press the button148 on the rack controller handle and the foot-pedal 156, and will also press the button 164 on the hoist controller handle as he moves the hoistcontrolle'r to the position forgiving re verse power to the motor, which, as already explained, is onthe lowerlng side of the con troller beyond the last lowering point.

All of the brakes and clutches for controlling the operation of the bucket by the hoist motor are set by springs and released by fluidpressure, so that in case offailure of, the pressure fluid supply, the clutches and brakes will be set and sustain the bucket and its load. It will also be apparent from the wiring diagram that the valve magnets are arranged to require current to release the brakes and clutches, so that failureof the current will leave the brakes and clutches set, preventing dropping of the bucket or its contents. 7

For the control of the trolley motion, in

case of direct current machines, the controller is usually arranged to provide dynamic brakingto retard the motion of the trolley. While'this has been very generally used, it

has one inherent defect,"this being that the braking effort onany one point of the controller. varies in intensity withthe speed,-being greater at the higher speed and gradually losing force as the speed isreduced. Thus dynamic braking-by itself produces a series of more or less abrupt peaks of braking effort, each followed by a gradual diminution of effort until the next point to which the controller is moved produces another peak. This 7 is-objectionable because it causes swinging of the bucket and discomfort to the operator if I the peaks are perceptibly higher in braking effort than the intervals between the peaks, that is, unlessthedynamic braking side ofthe controller has every large number of-control points. 9' I The use of air brakes on the trolley motion, in addition to dynamic braking,as previously provided by other control systems, does some thing toward overcoming this objection to the use of dynamic braking alone, but has required the manipulation of an additional air valve and thus added one more control unit.

My invention as described below gives a more uniform degree of braking effort, and requires less manipulation on the partof the operator. .It permits the use of a .low fluid fluid pressure-for emergencies without intro.-

pressure fornormal braking and a higher and 121'are. provided for the, two fluid pressures. These inlet valves and the exhaust valve 118 are controlled by contacts in the rack controller. Referring again to the piping and wiring diagram, the numerals 1 to 6, inclusive, shown on the bottom portion of the rack controller drum, on each side thereof, represent diflerentpositions of the controller for power, coasting and braking, in

I The zero represents the neutral or-otf posieither direction of travel of the trolley, 5 and 6 representpower positions, 41- the coasting position, and 1, 2 and 'braking positions.

I tion-of the controller. One side of each of the magnets'119, 122 and 128 is connected to conductor L by a conductor 170, and conductors 171, 172 and 17 3 lead from theother side of these magnets to fingers'174i, 175 and 17 6 in the rack controller. Segments 177, 17 8 and 17 9 on the rack controller drum are elece trically connected to the contact ring 1 17, and thelatter is connected to the conductor L through finger 1 14. and conductor 143.

When the controller is in apower position,

the fingers .17 1, 175 and 176 are in contact with'the segments 177, 178 and 179011 one side or the other ofthe controller drum,-depending. upon the direction of travel of the trolley, and consequently the magnets 119, 122 and 123 are energized, so that the exhaust valve 118 is open, and the inlet valves 120 and 121 areclosed, and hence the rack brake is released. On the coasting point (position 1),between the power and dynamic braking positions ofthe rack controller ineach direction, the rack motor brake is released the same as on the power points of the controller. On the first braking point (positiong), the

. controller gives minimum dynamic braking,

and the exhaust valve is closed, because finger 174C, inthis position of the controller, is

' not in contact with eithersegment 177, but

the inlet valves remain closed. On the next orsecon d braking point (position 2), the low pressure inlet valve is opened, because finger 176, in thisposition of the controller, is not 7 in contact'with either segment 179. As pre 'viously explained, this valve is fed through a, pressure reducing valve 124, readily adj ustaccount of wet rails or any'other reason, the

operatordesires to hold the braking effort uniform at a lower amount than that produced by the fluid pressure for which the reducing valve is set, the controller handle is moved back to the first brakingpoint, where the'inlet valve is closed, and where the excontroller'handles, and regular 01 haustvalve, remaining closed, retains in. the brake cylinder 111 the fluid pressure existing at the instant-the inlet valve'wasclosed. This is what is known as a lap' position. In case the fluid pressure has increasedabove what the operator'desires, moving the :con-

'troller handle momentarily to the coasting time opens the high pressure inlet-valve, be-

causeth'e finger 175 is then not'in contact with either segment 17 8. The adjustable choke valve 125 in the high pressure line'can be regulated so that the rate of increase of pressure when the high pressure valve. is 7 opened will not be too rapid, as it is desirable to have the increasing of pressure in the cylinder oithe rack brake occur at such a rate that the operator can stop the increase at any desired point.

The ability to obtain delicate and exact gradations in the braking effort on the trolley is of value, in thatit enables the operator to bring the trolley to a stop at the, desired point without making sudden or violent changes in the rate of retardation which cause swinging of the bucket and thus delay opeu ations.

" In the wiring and pipingdiagram I have not shown the electrical'connections for the dynamic braking, as such connections are so well known that it is thought that to show them-would not add to the clearness of the disclosure, but rather would'confuse the diagram. I have also deemed it unnecessary to show the piping and wiringconnections for the brakeoit' the other rack motor, as thesev are obviouslya duplicate of those shown. It will be understood, of course, that the wiring connections for both brakes are such that the same fingers and segments in the rack conthe utmost degree of flexibility in controlling the application of braking effort, withoutrequiring the use of any other controlunit than the handle'of the rack controller, and it is believed that it constitutes a material improvement over anycontr'ol system that has previously been devised'for the trolley-travel motors oi coal and ore bridges and similar machines. I i

By the provision o1 this combined control system for the bucket and trolley motors, I have made it possiblefor the operator to control all the movements of the bucket and trolley without removing his hands from the two ition te where" there no tendency for the tip, over while. closing, only one foot-operated switch is used in addition to the two. control-handles. .On rope system machines it has a further advantage over previous-control sys-,

tems, in thatztwo control-cabs can, be placed.

at advantageous points,,one for, unloading or stocking, forexample, and. the other for reclaiming thematerial and loading it out, andthis without requiring any mechanical operating levers or'air pipes to, extend fromone cab to the other or from. either cab to the enginev house.

I claim: 1 I

1.. Hoisting apparatus, comprising a, drum, a motor for operating'said drum, a controllerfor said motor, a fluid-pressure released brake for sa1d drum, a valve for controlling the.

pressure-fluid for releasing said brake, electrical means for actuating said valve, including contact means associated: with. and actuated upon movement of said controller, and a valve for preventing release of said brake by said pressure fluid when saidfirst-mentioned valve is actuated by said electrical means, sub-1 sa1d drums, a controller for each'of said mostantially as described. I

2; Hoistingapparatus, comprising'a drum, a'motor for operating said drum, a controller for said motor, a fiuid-pressure released brake for said drum, a fluidspressure released brake for said motor, a valve for controlling the pressure flu1d for releasing both brakes, electrical means for actuating said valve, including contact means associated with and actuated upon movement of said controller, and a valve for preventing release of the first-med tioned brake by said pressure fluid when said first-mentioned valve is actuated by said electrical means, substantially as described.

. 3. Hoisting apparatus, comprising a drum,

a motor for operating said drum, a controller for said motor, a clutch associated with said drum, and electrical means for controlling said clutch, including contact means associated with and actuated upon movement of said controller, and a switch, said switch being effective to close the circuit for controlling said clutch only when said controller is in the off position, substantially asdescribed.

4. Hoisting apparatus, comprising a trolley, a drum, a rack motor for operating said i trolley, a hoist motor for operating said drum,

a clutch associated with said drum, a controller for each of said motors, and electrical means for controlling said clutch, including contact means associated'with and actuated upon movementofsaidhoist controller, and

a switch operable from the rack controller handle, substantially as described.

5. Hoisting apparatus, comprising a trolley,- a drum, a rack motor for operating said trolley, a hoist motor for operating said drum a clutch associated with said'drum, a controller for each of said motors, and electrical means for controlling said clutch, including contact means associated with and actuated upon movement of said hoist controller and; a switch operable from the rack controllerhandle, said switch being effective to close/the;

circuit'for controlling said clutch only ;whe n said hoist controller is in a hoisting position,

substantially as described;

6.. Hoisting apparatus, comprising a trolley, a pair oi drums, a rack motor'foroper-Q ating said trolley, a hoist motor for operat-jing said drums,'a clutch associated with each oi sa1d drums, a controller for each of said motors, and electrical means for controlling-- 'said clut'ches, ncluding contact means asso:

mated with and actuated upon movement of 1 said hoist controller,'a switch in the circuit for controlling one of said clutches, and a of said clutches operable from the rack con troller handle, substantially as described.

7. Hoisting apparatus, comprising a trolley, a pair of drums, arack motor for operswitch in the circuit for controlling the other ating said trolley, a hoist motor for operating said drums, a spring-applied and fluid-pressure released clutch associated witheach of tors, and electrical means for controlling the pressure fluid for releasing said clutches, in- I cluding contact means associated withand actuated upon movement, of said hoistzcon troller, a switch, and a switch operable from the rack controller handle, substantially asdescribed.

8. Hoisting apparatus, comprisinga drum,

a motor for operating'said drum, a controller for said motor, and a switch operable from the controller handle forming part of the scribed.

9. Hoisting apparatus, comprising apair of drums, a motor for operating sa1d drums, a controller for sa1d motor, a clutch associated with one of said drums, electrical means for operating said clutch, a switch operable from the controller ha'ndle forming part of the circuit for giving reverse power to said motor, and a switch forming part oi the circuit for operatlng sa1d clutch, said switches being-effective to close sa1d circuits only when said controller is in its last lowering position, substantially as described.

10. Hoisting apparatus, comprising a pa r of drums, a motor for operating sa1d drums, a controller for said motor, a clutch associated with one of said drums, a. brake forsaid drum, electrical means for'etiecting release of said clutch and brake, including contact means associated with and actuated upon movement of said controller, a normally open switch in the circuit for releasing sa1d clutch, and means for simultaneously closing said switch andrendering said'electrical means inefiective to release said brake, said switch being effective to close said circuit only when saidcontroller is in'the position for giving J reverse power to the motor, substantially as 7 described. it g V i V '11. Hoisting apparatus, comprlsmg a pair of drums, a. motor for operating said drums,

a controller for said motor, a clutch associated with one of said drums, a brake for said drum,'electrical means for eifecting releaseof said clutch and brake, including contact means associated with and actuated upon movement of said controller, a normally "open switch operable from the controller handle forming part of the'circuit for giving reverse power to the motor, a normally open switch in the circuit for releasing said clutch,

and means for simultaneously closing the last-mentioned switch and rendering said electrical means ineffective to release said brake, said switches being-efieotive to close said circuits only when said controller is in of said controller, a normally open switch in the circuit for releasing said hold clutch, and

' means for simultaneously closing said switch and rendering said electrical means inefi'ective to release said brake, substantially as described;

13. Hoisting apparatus, comprising a trol 'ley, a drum, a rack motor for operating said trolley, a hoist motor for operating said drum, a clutch operatively connecting said drum to said hoist motor, a controllerfor' each of said motors, and electrical means'for effecting release oi said clutch, including a normally open switch operable from the rackcontroller handle and a second normally open switch, the switch on the rack controller handle being effective to close the circuit'for releasing said clutch only when the hoist controller is in a hoisting position and. the second switch being effective to close said cir-' cuit only when said controller is in a position forgiving reverse motor, substantially as described. 7

14. Hoisting apparatus, comprising a trolley, a drum, a rack motor for operating said trolley, a hoist motor for operating said drum, a clutch associated with saiddrum, a controller for each of said motors, and electrical,

means for controlling said clutch, including contact means associated with and actuated power to the hoist upon movement'of said hoist'controller, and

a switch operable from the rack controller handle but independent of the rack control, substantially as described.

In testimony whereof I have hereunto set 7 my hand.

RAYMOND E. BROWN,

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