US2342039A - Bucket conveyer - Google Patents

Description

N; L. DAVIS BUCKET CONVEYER Filed Sept. 28, 1942' Feb. 15, 1944.

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Feb. 15, 1944. N, L. DAVIS BUCKET CONVEYER Filed Sept. 28, 1942 4 Sheets-Sheet 4 .rllllll illlllllll TIME CLOCK Patented Feb 15, 1944 BUCKET comma Nehon L. Davis, Chicago, Ill. aealgnor to Link- Belt o p ny. Illinois Chicago, 111., a corporation of Application se amm es, 104:, Serial No. 45am 1: cum. (Cl. 198-141) My invention relates to improvements in automatic conveyers and has for one object to provide a new and improved form of conveyer which will receive, transport and discharge free flowing solid material.

Other obiects are to provide a conveyer, which will handle solid material with a minimum of degradation; use a minimum of power; which will include manually, semi-automatically or full automatically operating means for discharging materials from the buckets or for preventing overloading receiving chute or bin.

Other objects are to provide in combination with such a conveyer, discharge control mechanism whereby one or more discharge receptacles or conduits may simultaneously be supplied with the proper amount ofmaterial during continuous operation; and to combine in a single unit the functions of conveyer, feeder and discharger. A further object of the invention is to provide a type of conveyer wherein with a minimum of mechanism, a conveyer may'be provided which will convey successive batches of material in a substantially continuous flow for discharge at desired stations.

Other objects will appear from time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein-- Figure 1 is a plan view of a preferred form of my device;

Figure 2 is a side elevation;

' Figure 3 is a section on an enlarged scale along the line 3-4 of Figure Figure i is a section on an enlarged scale along the line 4-4 of Figure 1;

Figure 5 is a section along the line 5-5 of Figure 4;

Figure 6 is a section along the line H of Figure 2 on an enlarged scale showing the gate in the closed position;

Figure 7 is a section along the line 1-1 of Figure 1 showing the'gate in. the open position;

Figure 8 is a section similar to Figure 6 in somewhat greater detail showing the gate open with gate controlling means, section being taken, on 8-4 of Figure 7;

Figure 9 is a section along the line 99 of Figure 7 with the gate open;

Figure 10 is a section along the line l0ll of Figure 4;

Figure 11 is a section similar to Figure 9 showing the gate in closed position.

Like parts are indicated by like characters throughout the specification and drawings.

I, i, are two arms of a continuous conduit, joined atone endbyacheedhousingtiigidly attachedtothearms i, Landattbeother byahousinglwhichhasaleeveextensions telescopingwiththearms I, 2; Thearms I andthehousinglarerigidlymountedo framework shown diagrammatically at I. The housing 4 is slidably mounted on the sub-frame I andaswillhereinaiterappear,slackintheconveyer ehainis taken up by longitudinal movement of the housing under the impulse of the counterweight Ii connected by cable I passing over pulleys l and II with the housing 4.

I! and II are conveyer chain sprockets, one each in the housings 8 and 4. I4 is an endless conveyer chain illustrated diagrammatically in Figure 1 by dash lines, traveling over the sprockets II, It and carrying conveyer buckets as will hereinafter appear. The shalt ll iournaled at It and I1 carries rigidly mounted. thereon, a drive gear I and a conveyer sprocket II. It is a pinion in mesh with the gear Ill driven through a reduction gear ll from a motor 20. The sleeves a permit movement of the housing I without breaking the dust seal and without opening the conduit. The branches I, I and the housings I, I have floors 28 and side walls II, 21

and are closed at the'top by a removable cover shown diagrammatically at It. 22 is a feeder housing mounted on the cover 2| of the branch I and is adapted to receive-material through any suitable supp y D pe 23. The sleeves I where they telescopewlthrespectto thehousingl aretapered or thinned out in any suitable manner to provide a substantially smooth floor upon which the conveyer buckets may travel without interference as will hereinafter appear. This particular tapering of the sleeves is illustrated diagrammatically at 24a. The housing 22 has a hopper 24 and a cover 1'.

Spaced inwardly from the side walls 25, 21 are track strips a supported on webs ll projecting inwardly from the side walls. and thus ample clearance is left between the walls It and 21 and the track strips 29. conveyer buckets II, some or all of them, having roller shaits 32 which carry flanged wheels Ii to travel along the track strips 2!, have upwardly extending flanges 34 to engage links Ii or 38 of the chain ll, there being one link for each bucket. The links are articulated by pintle pins 31 so as to make a continuous drive chain propelling and supported on the buckets ii. The chain ll travels around the sprockets i2 and II and is always supported above the level of the buckets andabove and to one side ofthe material contained in the buckets. This prevents abrasion and clogging of the chain.

Each bucket includes two hoppers 38 and 39; the front wall of each hopper 38 is masked by the lip 40 extending rearwardly from the back hopper 39 of the preceding bucket so that when the buckets are in line they present a continuous surface, the lip of each preceding bucket overlying the adjacent wall of the succeeding bucket. This overlap is effective always whenever the chain is traveling along a straight line. It is not the case with respect to travel around the sprockets l2 and it because the chain is adjacent the inner body of the conduit and as the chain travels around the sprockets l2 and I 3, the buckets spread apart.

This characteristic of the chain and buckets limits the position of the feed housing 22. It can be anywhere in the system except where the chain is traveling around the sprocket. The feed housing as shown in Figure 3 contains the hopper 24 having a downwardly extending discharge spout 4| terminating just above the upper surface of the lips. 40. The spout 4| has side walls 42 carrying downwardly extending flexible scraping members or squeegees 43 which may actually come in contact with the lip 40. The downstream spout wall 44 has a squeegee 45 which comes down also to just touch the lip 40. The squeegees 43 and 45 may be of rubber asindicated, held in position by strips 46, and nut and bolt combinations 41 or maybe of any other suitable flexible material. If desired, the spout 4| may come down almost to contact with the lip 40, preferably, however, in order to avoid binding. it is well to have some flexible medium between the lower end of the spout and the lip 40.

As the conveyer buckets are moved in the direction of arrows shown in Figure 4, with the hopper 24 containing a sufilcient supply of material, the material flows through the spout 4! to fill each successive bucket atpit passes beneath the spout, the size of the spout being sufiicient with respect to the speed of bucket travel so that by the time the bucket has passed the spout, the bucket will be filled level. Surcharging or overfilling of the bucket is impossible because as the material fills the bucket and banks up in the spout, the actual contact of the squeegees 43 and 45 provides a closed system to prevent any appreciable overflowing of the material. Thus each I bucket is level filled and goes forward in a level filled condition after it has left the feed spout.

The floor of the conduits is continuous and smooth except at the point above referred to where the sleeve extensions 5 are chamfered or tapered so as to reduce to a minimum interference between the buckets 3 I. The weight of each bucket is supported on the track through the rollers but the relationship between rollers, track,

buckets and conduit is such that the open bottom of the bucket travels along the bottom of the track, there being a light working contact between the bucket bottom and the floor of the conduit. The pressure may be slightly increased at those points where the bucket travels from the conduit into and out of the sleeve extensions 5 and in that area where the buckets are traveling around the housing 4 but the distance is short, the metal is thin and the increased friction is not important.

Each bucket is open at the bottom but the cross sectional area of the open bucket bottom as indicated at u is so much smalierthan the cross sectional area of the bucket that the weight of most of the material in the bucket is supported by the tapered or inclined walls, only a small proportion of the weight being carried by the door of the trough. There will be some leakage. some abrasion, some wastage of material between the floor of the trough and bucket walls where they engage the floor but such wastage will be proportionately very small and the friction load applied to the apparatus by sliding the material exposed in the bucket mouth to the floor of the conduit will be very slight.

The plane defined by the four boundaries of the bucket mouth will in all cases be parallel with the plane of the fioor of the conduit. Thus the floor of the conduit maintains a continuous closure to prevent outflow from the bucket and each bucket is filled as it passes beneath the filling hopper and losing little if any of its burden as it travels along the conduit.

Spaced along the conduits I and 2 in the fioor I thereof are a plurality of discharge openings 40, and ii. Opening 50 is always open. Opening BI is always partially or entirely open and opening 49 may be opened or closed depending upon the position of the gate 52. When in the position shown in Figure 6, the gate 52 closes the opening ing 48 of the buckets. The upper surface of the sliding gate 52 is in the same plane as the upper surface of the floor of the conduit so that when the gate is closed, the bucket travels along the floor of the conduit and along the surface of the gate, the floor of the conduit and the upper surface of the gate 52 both acting as adequate closures for the bottom of the bucket. iAny suitable mechanism can be used to move the gate 52 from open to closed position or vice versa. As illustrated, it takes the form of tracks I! on the underside of the floor 28 of the conduit. In the closed position as shown in Figure 6, the ports 50 and 5| are both open, the port 49 is closed. Ears 55 extend downwardly from the gate 52 and are engaged by pins 56 on lever arms 51 rigid on the shaft 58 rotatably mounted in the walls I! of a hopper 60. A port 6| in the hopper walls OI permits a lever 62 to project from the hopper, the lever being rigidly mounted on the shaft II. The lever is slotted as at 63 engaged by a'pin '4 on the solenoid plunger 65. The solenoid It may open the gate against the tension of the spring 61 when the gate 52 is opened to open the port 49 and it partially closes the port 5| as indicated in Figure 9. As soon as current is shut off from the solenoid 66, the spring 61 again closes the gate 52.

Spaced buckets 3! are provided on their forward sides with ears 10, supporting pivot pins II on which are pivoted links I2 extending rearwardly on both sides of a bucket 3| to support an angular scraper blade II, having a fiexible squeegee 14 adapted to travel along the fioor of the conduit, there being room between adjacent buckets for the squeegee to travel, the squeegee blade being tapered outwardly and rearwardly in both directions from the center line so that material which may leak out from between the bottom of the bucket and the floor of the conduit will be picked up by this squeegee, moved forwardly and outwardly so that any such material will be discharged through the constantly opened ports I. and II into the first discharge hopper to be reached during the travel of the bucket after the material has escaped from the bucket.

Any suitable means can be used to control the time of discharge or the time during which discharge is permitted from a bucket as it passes over-"any one of the discharge ports ll. As indicated in Figure 8, current comes i'rom any suitable source of electric power through conduits II and I8. Conduit II is directly connected to one pole of the solenoid, conduit I! is broken by the manually controlled switch 11 and it is connected to the other pole of the solenoid. When that switch is closed by hand, the gate is opened. When the switch 11 is opened by hand the gate closes. As indicated a time clock having any suitable timing mechanism with an automatically controlled switch arm I! may also be used to control the operation of the solenoid. The time clock has two or more contact poles II, 00. As shown in Figure 8, 18 engages l and current travels from conduit I6 through conductor II to terminal ll, thence through the contact arm ll, conductor 82 to conductor 16 to actuate the solenoid to open the gate. In the device disclosed in Figure 8, the gate is opened twice during every revolution of the time clock, the arm I. contacting each of the terminals I9 and 80 once during each revolution and the rate of travel of the time clock controls the time during which the gate is open.

It is the essence of the invention that each bucket is full when it leaves the filling hopper shown in Figure 4. The rate of travel of the conductor is normally fixed. The rate at which material is to be fed to each of the discharge hoppers will be known so each time clock will be set to open gates often enough and for long enough time to provide the proper amount of material for each hopper 60.

If by accident the demand on any one of the hoppers 60 becomes less than was intended. it the operator notices the situation, he can stop the clock or elsewhere break the circuit to permit the spring to close the port. If neither of these things happen, material will back up into the hopper 60 until it is full. Then as successive buckets pass over the open gate, no appreciable discharge will take place because the material in the hopper 60 will prevent any appreciable outflow from the bucket. There will under these circumstances be an increased amount of material wiped off by the bucket and a tendency to increase the frictional drag on the apparatus and so to increase degradation of material. However. any such material which is wiped out of port 4! beyond the discharge point will only travel with the conveyer to the next discharge p rt and that port will always be open. Since only a little of this material will be propelled, the pressure on it will be very light and so for this reason also degradation and frictional resistance will be reduced to a minimum.

Suitable means may be provided to prevent overcharging of one of the hoppers l. A pendulum 9| pivoted on a bracket depending from the floor 28 has a head 90 which may be pressed sideways to the right into the dotted line position as material piles up in the hopper. The pendulum has a switch arm 92 in opposition to a contact 93 and a, conductor 94 leads from the wire to the switch point 93 and when the pendulum 9| is in the full line position, the circuit is closed at 92 through the conductor 95 back to the source of power so that until the material piles up in the hopper enough to move the member II tothe right and break the circuit. the circuit is under the control of the time clock. If, however, the hopper fills up beyond the danger point, the circuit will be broken. the solenoid can then not be energized by the time clock, the spring I! will hold the gate closed and no more material willbe supplied to the hopper until the hopper is emptied enough to permit the pendulum II to swing back to the full line switch closing position.

In dealing with materials of the type for which this apparatus is primarily intended, it is important that no violent motion, no impact be imparted to the material.

While I have illustrated a long link chain with a relatively long bucket attached to each link, each bucket having two hoppers and two discharge ports, the effect desired might equally well be obtained by a different type of bucket than the two hopper bucket, it to be regarded as merely illustrative and an effort to obtain maximum capacity with minimum weight. Because of the fact that the conduit must be kept closed and because of the fact that the buckets pass through the entire area of the conduit. a special type of take-up is needed, the conduit having commenced telescoping with respect to the fixed conduits so that as the take up moves under tension of the counterweight to compensate for wear in oaths chain, the conduit remains continuous and c1 The frictional resistance resulting from the movement of the material along the floor 28 while contained within the bucket is low because of the small area of material exposed in the narrow bucket discharge opening. The weight of this material pressing upon the floor does not represent the entire weight of material in the bucket by any means because the cross sectional area of the port is much less than the cross sectional area of the bucket, the port therefore only supports that part of the material actually overlying the port with the additional pressure applied thereto caused by the pressure of material in the bucket, being supported on the inclined walls of the bucket.

While the buckets are enclosed in a conduit having a closed bottom, the bottom serving as a closure for the buckets, it will be understood that the conduit might be, omitted, the bottom only being present, the essential thing being that the bottom of the conduit, or floor, or shelf, along which the buckets travel be continuous except at the discharge points. The individual buckets carry uniform successive batches of material from the loading to the discharging zones or stations and there is, as a result a minimum of degradation and rubbing or abrasion of the material as it is conveyed.

I claim:

1. In a conveyer system, a plurality of buckets open at top and bottom arranged in a continuous series and overlapping at their adjacent edges, a filling spout in line with tin: buckets terminating immediately adjacent the plane" of the open tops of the buckets, means for normally closing the open bottom of each bucket and means in the path of travel of the buckets for opening the open bottom of each bucket to permit discharge therefrom, said means including a floor along which the buckets travel, the floor being in sliding contact with respect to the buckets, there being a port in the floor in line with the open bucket bottoms as they travel along and means for openmaterial in the hopper for causing the gate closin: means to operate.

2. A conveyer including a track, rollers adapted to travel therealong, buckets associated with and supported by said rollers on the track, each I bucket having an open top and an open bottom,

a floor supported beneath the track adapted to be engaged by the open bottom of the bucket whereby the floor closes the bucket, means for propelling the buckets along the track and floor, a discharge port in the floor inline with the open bottom of the bucket, walls extending upwardly from the floor, a port located out of line with the port associated with the bucket bottom, a scraper mounted to travel with the buckets along the floor, the scraper having an inclined squeegee adapted to convey material which escapes from the bucket along the floor both longitudinally and laterally to discharge it through the second port.

3. A conveyer including a track, rollers adapted to travel therealong, buckets associated with and supported by said rollers on the track, each bucket having an open top and an open bottom, a floor supported beneath the track adapted to be engaged by the open bottom of the bucket whereby the floor closes the bucket, means for propelling the buckets along the track and floor, a discharge port in the floor in line with the open bottom of the bucket, 'a gate adapted to close said port, the upper level of the gate and floor being substantially the same, walls extending upwardly from the floor, a port located out of line with the port associated with the bucket bottom, a scraper mounted to travel with the buckets along the floor, the scraper having an inclined squeegee adapted to convey material which escapes from the bucket along the floor both longitudinally and laterally to discharge it through the second port.

4. A conveyer including a conduit, a series of buckets open at top and bottom, means for propelling them along the conduit, the conduit having a closed floor, means independent of the floor for supporting the buckets, the open bottoms of the buckets being in engagement with the floor,

a scraper associated with one of the buckets and adapted to travel along the floor of the conduit to collect and convey material escaping from the buckets into the conduit, a plurality of ports in the conduit, one port being in line with the open bucket bottoms adapted to permit discharge of material therethrough from the buckets, and another port being in line with the material gathered by said scraper.

5. A conveyer including a-conduit, a'series of buckets open at top and bottom, means for propelling them along the conduit, the conduit having a closed floor, means independent of the floor for supporting the buckets, the open bottoms of the buckets being in engagement with the floor, a scraper associated with one of the buckets and adapted to travel along the floor of the conduit to collect and convey material escaping from the buckets into the conduit, a plurality of ports in the conduit, one port being in line with the open bucket bottoms adapted to permit discharge of material therethrough from the. buckets and another port being in line with the material gathered by said scraper, a gate adapted to close said port, the port surface of the gate and the conduit floor being in the same plane.

v 6. A conveyer including a conduit, a series of buckets open at top and bottom, means for propelling them along the conduit, the conduit having a closed floor, means independent of the floor for supporting the buckets, the open bottoms of the buckets being in engagement with the floor, a scraper associated with one of the buckets and adapted to travel along the floor of the conduit to collect and convey material escaping from the buckets into the conduit, a plurality of ports in the conduit, one port being in line with the open bucket bottoms adapted to permit discharge of material therethrough from the buckets, a gate adapted to close said port, the port surface of the gate and the conduit floor being in the same plane, a port alongside of the first mentioned port out 01' line with the bucket bottom permanently open adapted to receive discharge from the scraper.

7. A conveyer system including a generally plane surfaced supporting member having therein a plurality of discharge apertures, gates for said discharge apertures which have surfaces which, when the gates are closed, lie in substantially the same plane as the surface-of the supporting member, a plurality of buckets, each said bucket having circumferentially extending side walls, the

lower edges of which define an open bottom aperture, the buckets being open'at the top, means for movingsaid buckets across said supporting members along a path which passes the open bottom apertures of the buckets directly across the discharge apertures, means for supporting the buckets during their movement with the lower edges of their circumferential side walls engaging the surface of the supporting member, means for actuating said gates whereby, when the gates are open, material from the buckets, may be freely discharged from the bucket bottom apertures through the discharge apertures of the supporting member and receiving hoppers located beneath said discharge apertures and means responsive to the presence of a predetermined mass of material in each said hopper, for preventing opening of the gate of the discharge aperture associated with said hopper.

8. A conveyer system including a generally plane surfaced supporting member having therein a plurality of discharge apertures, gates for said discharge apertures which have surfaces which, when the gates are closed, lie in substantially the same plane as the surface of the supporting member, a plurality of buckets, each said bucket having circumferentially extending side walls, the lower edges of which define an open bottom aperture, the buckets being open at the top, means for moving said buckets across said supporting members along a path which passes the open bottom apertures of the buckets directly across the discharge apertures, means for supporting the buckets during their movement with the lower edges of their circumferential side walls engaging the surface of the supporting member, means for actuating said gates whereby, when the gates are open, material from the buckets may be freely discharged from the bucket bottom apertures through the discharge apertures of the supporting member, and means for feeding material to the open tops of the buckets including an open bottomed filling spout in line with the buckets and having a lower edge terminating immediately adjacent the plane of the open tops of the buckets, said filling spout having a yielding, wiping wall adapted to engage the upper edges of the buckets as they pass beneath the spout.

9. A conveyer structure which includes a conveyer fioor having a generally plane surface, an endless conveyer including a plurality of buckets, means for moving the conveyer across and above the floor along a predetermined path, each such bucket having side and end walls circumferentially surrounding the space within the bucket, said walls defining at their upper edges a top bucket opening, and defining with their lower edges a bottom discharge opening, the lower edges of said walls terminating in a plane conforming generally to and lying closely adjacent the plane surface of the floor, the floor being adapted normally to close the otherwise open bottom discharge opening, the fioor having a discharge station on the path of travel of the buckets, including a discharge port in the fioor in line with the line of travel of the bucket bottom apertures.

10. A conveyer structure which includes a conveyer fioor having a generally plane surface, an endless conveyer including a plurality of buckets, means for moving the conveyer across and above the floor along a predetermined path, each such bucket having side and end walls circumferentially surrounding the space within the bucket, said walls defining at their upper edges a top bucket opening, and defining with their lower edges a bottom discharge opening, the lower edges of said walls terminating in a plane conforming generally to and lying closely adjacent the Plane surface of the floor, the floor being adapted normally to close the otherwise open bottom discharge opening, the floor having a discharge station on the path of travel of the buckets, including a discharge port in the fioor in line with the line of travel of the bucket bottom apertures, a movable closure member for the discharge port, mounted at the port, and means for moving said closure member to closed position, in response to overfeeding of the station to a predetermined level, the closure member lying sufficiently close to the plane of the fioor to prevent any discharge from the bucket when the closure member is in closed position.

11. A conveyer structure which includes a conveyer fioor having a generally plane surface, an endless conveyer including a plurality of buckets, means for moving the conveyer across and above the floor along a predetermined path, each such bucket having side and end walls circumferentially surrounding space within the bucket, said walls defining at their upper edges a top bucket opening, and defining with their lower edges a bottom discharge opening, the lower edges of said walls terminating in a plane conforming generally to and lying closely adjacent the plane surface of the fioor, the fioor being adapted normally to close the otherwise open bottom discharge opening, the fioor having a discharge station on the path of travel of the buckets, i cluding a discharge port in the fioor in line with the line of travel of the bucket bottom apertures, and means for filling the buckets to a level substantially even with the upper dges'of the bucket walls.

12. A conveyer structure which includes a conveyer floor having a generally plane surface, an endless conveyer including a plurality of buckets, means for moving the conveyer across and above the floor along a predetermined path, each such bucket having side and end walls circumferentially surrounding the space within the bucket, said walls defining at their upper edges a top bucket opening, and defining with their lower edges a bottom discharge opening, the lower edges of said walls terminating in a plane conforming generally to and lying closely adjacent the plane surface of the fioor, the fioor being adapted normally to close the otherwise open bottom discharge opening, the floor having a discharge station on the path of travel of the buckets, including a discharge port in the fioor in line with the line of travel of the bucket bottom apertures, and means for filling the buckets to a level substantially even with the upper edges of the bucket walls, th upper edges of the walls lying in a plane parallel with the plane of the lower edges of the walls, and with the conveyer floor.

13. In a conveyer system, an open-topped bucket having a bottom discharge aperture, means for conveying the bucket along a path, a discharge station positioned on the path, and including a discharge member adapted to form with the discharge aperture of the bucket, a discharge passage for the material in the bucket when the bucket is aligned with the discharge station, a movable closure member located in said discharge passage, said closure member being normally in the open position when the bucket I is aligned with the station, and means responsive

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