US2722323A - Bucket dumping apparatus - Google Patents

Description

NOV. 1, 1955 HACKNEY 2,722,323

BUCKET DUMPING APPARATUS Filed May 19, 1954 FIG. 1.

FIG.2.

INVENTOR DONALD E. HACKNEY BY I Mfpwzy ATTORNEY United States Patent Ofifice 2,722,323 Patented Nov. 1, 1955 BUCKET DUMPING APPARATUS Donald E. Hackney, New Castle, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, eh, a corporation of Delaware Application May 19, 1954, Serial N 0. 430,825

3 Claims. (Cl. 214 -64) This invention relates to a bucket dumping apparatus, and particularly to an automatic bucket dumping apparatus for use in conjunction with a traveling bucket.

It is often advantageous to convey inflammable or explosive powders, such as dynamite powder mixes, by

a traveling bucket and, since the loads are relatively great, a powered means is necessary for dumping the bucket. Safety and fire hazard precautions necessitate the use of smooth-operating, non-sparking devices for such service and this invention has been devised to meet the requirements, it being understood that it is broadly applicable to any like conveyor systems, regardless of the nature of the material transported.

An object of this invention is to provide a simple bucket dumping apparatus for use in conjunction with a traveling bucket. Another object of this invention is to provide a bucket dumping apparatus which is particularly suited to operation in hazardous environments. Another object of this invention is to provide an automatic bucket dumping apparatus which is adapted for use with either fluid pressure or electrical control systems. The manner in which these and other objects of this invention are accomplished will become apparent from the detailed description and the following draw ings in which:

Figure 1 is a plan view of a typical traveling bucket conveyor system provided with one embodiment of bucket dumping apparatus according to this invention, and

Figure 2 is a side elevation view of the bucket dumping apparatus taken on section 2-2 of Fig. 1.

Generally, this invention comprises a stationary pulley system which is provided with a tensioning pulley which is adapted to swing arcuately and thereby tension the belt threaded over the pulley system to maintain powertransmitting contact with a bucket dumping pulley adapted to rotate the supporting shaft of the traveling bucket when the bucket is halted at dumping location. Suitable controls for sequential operation are provided in the preferred embodiment of the hereinafter described invention, the control apparatus specifically described being hydraulic but it being understood that fluid pressure controls generally, or electrical controls, are equally suitable for the purposes contemplated.

Referring to Fig. 1, the traveling bucket is indicated in plan at 16, the bucket being supported by shaft 11 journaled in cantilever relationship to traveling carriage 12 through pillow blocks 14 integral with the carriage. Carriage 12 is supported on flanged wheel trucks, the wheels 15 of which engage with rails 17 supported on ties 18. The carriage is drawn along the rails by chain 19, which is attached to couplings 20 provided at opposite ends of carriage 12. As seen in Fig. 1, the direction of travel of the carriage into dumping location is towards the right, while the carriage is withdrawn for reloading of bucket 10 by travel to the left. Shaft 11 is provided with three cams securely keyed thereto, these being designated 23, 24 and 25. Shaft 28 is fixedly supported in brackets 29 mounted on carriage 12 in parallel relationship with shaft 11. Shaft 28 is provided with three bell cranks, 7, 8 and 9 journaled on the shaft, the arms adjacent to shaft 11 of which carry followers 31, 32 and 33, respectively, which co-operate with cams 23, 24 and 25, respectively. The remaining arms of the bell cranks, namely 36, 37 and 38 are provided for camming co-operation with the actuating mechanism for the bucket dumping apparatus, all as hereinafter described in detail. As indicated in Fig. l, the arms of the bellcranks carrying followers 31, 32 and 33 overbalance the weights of the opposite arms of the bell cranks and, at all other times than when carriage 12 is in dumping location, rest against support bar 39 integral with brackets 29.

Shaft 11 is provided with a driven gear 41 keyed to the shaft, gear 41 meshing with driver gear 42 keyed on power output shaft 43 of speed reducer 44. The power input shaft 45 for speed reducer 44 is journaled in a bearing supported by stationary cam plate 46 and in pillow block 48, the cam plates 46 and 47 and pillow block 48 being bolted to carriage 12. Driving pulley 49 is keyed to shaft 45 in cantilever relationship with carriage 12 in a plane at the location of the bucket dumping apparatus of this invention common with the plane of the other pulleys of the embodiment of this invention shown in the drawings. Cam plates 46 and 47 are provided with clevis portions 50 and 51, respectively, which are adapted to engage with the actuating mechanism for the bucket dumping apparatus as hereinafter described.

Referring to Figs. 1 and 2, the bucket dumping apparatus of this invention comprises the three-pulley a1- rangement consisting of drive pulley 55, idler pulley 56 and tensioning pulley 57, over which is threaded endless drive belt 58. The three pulleys are journaled in bearings mounted on stationary support frame 60 which may be fastened to the building framework, or otherwise fixedly secured at the bucket-dumping station. Frame 60 is provided with a vertical flange 61 which is stiffened in the rear by braces 62, and is provided with a forwardly directed shelf portion 63. Pillow blocks 64 are mounted on shelf 63 and shaft 65, to which idler pulley 56 is keyed, is journaled therein. Referring to Fig. 2 especially, the drive shaft for the dumping apparatus is shown at 70, drive pulley 55 being keyed to the outboard end of this shaft, while the opposite end of the shaft is coupled to the drive shaft 71 of powering motor 72. It will be understood that shaft is journaled in suitable pillow blocks mounted on the front side of frame 60, one of these pillow blocks being indicated at 73 in Fig. 2. The opposite end of flange 61 is provided with a boss 76 disposed in cantilever relationship to the plate in the direction of carriage 12, boss 76 being adapted to receive stud 77 on which is journaled bell crank 78, one arm of which is provided with hearing 79, in which is journaled stud shaft to which is keyed tensioning pulley 57. The other arm of bell crank 78 is provided with a counterbalancing weight 81, which is proportioned so that the force couple exerted by it on bell crank 78 is sufiicient at all times to maintain power-transmitting tightness in belt 58.

A typical control apparatus for this invention can comprise the apparatus hereinafter described, which is shown schematically in Fig. 1, it being understood that a wide variety of control equipment may be advantageously used in conjunction with the bucket-dumping apparatus. All control equipment is stationary and mounted in fixed relationship to rails 17 for co-operation with the clevises of cam plates 46 and 47 and arms 36, 37 and 38 of hell cranks 7, 8 and 9, all mounted on carriage 12. In the embodiment of this invention described herein in detail, it is assumed that motor 72 is of the hydraulic type and, also, that the motor (not shown) pulling chain 19 is also hydraulic.

Five separate controls, adapted to operate in sequence, are indicated schematically in Fig. 1, these being the spring-biased hydraulic flow control valves 85, 86, 87, 88, and 89. The hydraulic system of the motor drawing chain 19 is provided with a snubber, not further described herein because it does not constitute part of this invention, which is adapted to bring the carriage to a halt at the dumping location in its travel from left to right, as seen in Fig. 1, in a position such that clevises 50 and 51, and bell crank arms 36, 37 and 38 on the carriage co-operate with the defiectible spring-biased valve stems of 85--89, inclusive, the arrangement of the devices mounted on the carriage and the valve stems being such that no extreme precision of placement, beyond that necessary to locate bucket over the receiver accepting its contents, is required.

Valve 85 is connected in flow regulating relationship through control line 92 with motor 72, while valve 87 is also connected in flow regulating relationship to the motor through control line 93. Valve 88 is connected in flow regulating relationship to the hydraulic system powering the motor drawing the chain by control line 94 and valves 86 and 89 are connected in flow regulating relationship to opposite sides of cycling-prevention memory device 96, which may be a Vickers, Inc., 4-way hydraulic valve, through control lines 97 and 98, respectively.

In operation, motor 72 is normally stationary and does not operate unless carriage 12 with its bucket 10 is spotted in proper position with respect to the unloading location and with the several devices on the carriage depressing the spring-biased valve stems of their associated valves. Sequential operation of the various control valves responsive to the co-operating devices on the carriage is obtained by the disposition of two of the five valves adjacent to clevises 50 and 51 and by providing the rotatable earns 23, 24 and 25 with suitable profile contours to affect the desired sequential operation of the adjacent valves 87, 88 and 89, respectively.

Thus, when the carriage arrives at the location at which dumping is conducted, clevis 51 on cam plate 47 deflects valve 85 to open position, thus permitting hydraulic fiow to motor 72 through line 92, starting the motor and commencing the cycle. At the same time, valve 86 is opened by clevis 50 on cam plate 46, thus opening hydraulic fiow through line 97 in circuit with cycling prevention memory device 96, which is interlocked with motor 72 by conventional controls not shown, and thus prevents recycling of motor 72, except when a new carriage is received in dumping location. Arrival of carriage 12 at dumping location deflects bell cranks 7, 8 and 9 from normal position'against support bar 39 to a position permitting co-operation of followers 31, 32 and 33 with earns 23, 24 and 25, respectively, as hereinafter described, by abutment of arms 36, 37 and 38 against the spring-biased stems of valves 87, 88 and 89, the spring resistances of which overcome the inertia of the bell cranks without opening of the valves. It will be noted from Figs. 1 and 2 that, at dumping location, driving pulley 49 is moved past the plane including the centerlines of idler shaft 65 and drive shaft 70 in the direction of take-up pulley 57, thereby bringing pulley 49 into power-receiving relationship with respect to belt 58. Accordingly, motor 72 transmits power through belt 58 to pulley 49, and thence through shaft 45 to speed reducer 44. This drives output shaft 43, drive gear 42 and driven gear 41, thereby turning shaft 11, to which bucket 10 is secured, to initiate dumping of the material contained in the bucket. The directions of rotation ofshafts 45 and 11 are represented in a typical installation by the arrows drawn adjacent to the shafts, the direction 4 of rotation of bucket 10 being, of course, the same as that of shaft 11.

The profile contours of cams 23, 24 and 25 are chosen so that they produce one complete rotation of bucket 10 and restore it to the precise position shown in Fig. 1 upon completion of the camming cycle. The sequence of operation is that, under rotation of shaft 11 and near the end of a complete rotation of bucket 10, cam 24 first actuates its follower 32, thereby raising the outer bell crank arm 37 and overcoming the spring resistance of valve 88 to open the valve, thus permitting hydraulic flow through line 94 to start up the chain-driving motor and thus draw carriage 12 to the left, i. e., in the reverse direction to its approach, as seen in Fig. 1. It will be noted that driving pulley 49 remains in power-receiving relationship with respect to belt 58 until it is moved to the left (refer Fig. 2 particularly) to the outermost left-hand radii of pulleys 55 and 56 and, accordingly, shaft 11 continues to turn during the initial movement of carriage 12 to the left. In the course of this movement clevis 50 clears valve 86, thus permitting closure of the valve, and, immediately thereafter, cam 25 deflects follower 33, thus raising the outer bell crank arm 38 against the spring resistance of valve 89 to open this valve and restore cycling-prevention memory device 96 to its original position permitting the initiation of another dumping cycle when carriage 12 returns to dumping location. The design of cam 23 and its associated follower 31 is such that, under slight continued rotation of shaft 11, the outer bell crank arm 36 is raised against the spring resistance of valve 87, thereby opening flow through valve 87 and line 93 to halt the rotation of motor 72. It will be understood that the operation of valves 88, 89 and 87, in the sequence named, occurs within a very small interval of travel of carriage 12 to the left, as seen in Fig. 1, an amount less than that necessary to clear driving pulley 49 from contact with belt 58, immediately after valves 85 and 86 are cleared by clevises 50 and 51. As soon as driving pulley 49 is drawn clear of the left-hand radii of pulleys and 56 by movement of carriage 12 to the left, belt 58 is brought up taut along the vertical plane by rotation of bell crank 78 in a clockwise direction, as seen in Fig. 2, under the influence of counterbalancing weight 81. Carriage 12 then travels to the left to its loading location, and the dumping apparatus remains inactive until the carriage returns once again to the dumping location.

While a weighted counterbalance for bell crank 78 is hereinabove described for take-up of belt looseness through tensioning pulley 57, it will be understood that a suitable spring biasing pulley 57 against the tension of belt 58 may be utilized equally as well. However, in this case, suitable stops must be provided on support plate 60 or flange 61 to limit the range of oscillatory movement of hell crank 78 within desired limits.

From the foregoing, it will be understood that this invention may be modified in numerous ways without departure from its essential spirit, wherefore it is intended to be limited only by the scope of the following claims.

What is claimed is:

1. A bucket-dumping apparatus comprising the combination of a frame, a drive motor mounted on said frame, said motor being provided with a drive shaft, an idler pulley shaft and a bell crank support shaft journaled on said frame, all of said shafts being disposed substantially parallel one to another and in cantilever relationship to the same side of said frame, belt-engaging pulleys fixedly secured to said drive shaft and to said idler pulley shaft, said drive shaft and said idler pulley shaft being disposed transverse to the direction of approach of the traveling bucket to be dumped with sufficient clearance between said belt-engaging pulleys to provide a .running length of belt therebetween for driving engagement with a dumping means carried along with said traveling bucket, a bell crank journaled on said bell crank support shaft, :1

belt-engaging tensioning pulley journaled on one arm of said bell crank in a common plane with said first-mentioned belt-engaging pulleys, counter-balancing means attached to the other arm of said bell-crank, said counterbalancing means being adapted to maintain a driving belt continually taut against all three of said pulleys, and an endless driving belt threaded over said pulleys.

2. A bucket dumping apparatus according to claim 1 wherein said counter-balancing means comprises a weight preselected to maintain said driving belt continually taut.

3. A bucket dumping apparatus according to claim 1 including control means carried along with said traveling bucket adapted to co-operate with second control means at the dumping location to start sequentially said drive motor, actuate a memory device to recycling-prevention position, actuate the traveling bucket drive to reverse the direction of travel, restore said memory device to cycle-permitting position and stop said drive motor.

References Cited in the file of this patent UNITED STATES PATENTS 2,637,455 Mitchell May 5, 1953

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